WorldWideScience

Sample records for brycon opalinus cuvier

  1. Gonadossomatic relation and reproductive strategy of Brycon opalinus (Cuvier, 1819 in the Serra do Mar State Park - Núcleo Santa Virgínia, Atlantic Forest, Brazil

    Directory of Open Access Journals (Sweden)

    LM Gomiero

    Full Text Available The objective of this study was to analyze the gonadossomatic relation of males and females of Brycon opalinus (the Pirapitinga do Sul in the Serra do Mar State Park-Núcleo Santa Virgínia. The study area included three rivers: Paraibuna, Ipiranga, and Grande. From the gonadossomatic relation, it was possible to determine the reproductive season and strategy of this species. The gonadossomatic relation was high throughout the year for both males and females. Sperm competition and dilution of the ejaculate in the spawning locations favored substantial development of the testicles. The sex ratio of Brycon opalinus was always in favor of females. The existence of sexual dimorphism in this species was confirmed from the larger size of the females.

  2. Concrete-Opalinus clay interaction

    International Nuclear Information System (INIS)

    Jenni, A.; Maeder, U.; Lerouge, C.; Gaboreau, S.; Schwyn, B.

    2012-01-01

    Document available in extended abstract form only. Designs for deep geologic disposal of radioactive waste foresee cementitious materials as structural elements, backfill or waste matrix. Therefore, studies of interactions between cement and all other materials involved are important. Interactions are mostly driven by chemical gradients in pore water and might lead to mineralogical alterations in the barrier system, which in turn influence properties like swelling pressure, permeability, or specific retention in case of clay materials. Existing laboratory and in-situ studies using clay-stone revealed significant alteration in both cement and clay-stone. Phase dissolution, precipitation, and carbonation, were found to cause an overall porosity increase in the cement with a possible decrease close to the interface, and clogging in the clay-stone [2]. Most of the work was done on cement pastes rather than concretes to avoid analytical complications caused by aggregates, and the scale of investigation was chosen in the range of centimetres rather than micrometers. The Cement-Clay Interaction (CI) experiment at the Mont Terri Underground Laboratory (St. Ursanne, Switzerland) aims at replicating some of the processes at interfaces to be expected.For this purpose, two vertical cylindrical boreholes (384 mm diameter, up to 10 m length) in Opalinus Clay (OPA) were filled with layers of three different concretes and bentonite. The concrete formulations are based on common aggregate content and grain size distributions, combined with three different cements: Portland cement (OPC), ESDRED cement especially designed for repository applications (40% of cement substituted with silica fume), and low alkali cement (LAC, containing slag and nano-silica).In this study, we present a characterisation of the three concrete-OPA interfaces after two years of alteration and deduce possible mechanisms. Backscattered electron (BE) imaging and energy dispersive spectrum (EDX) element mapping

  3. Assessment of geomechanical properties of intact Opalinus Clay - Expert report

    International Nuclear Information System (INIS)

    Amann, F.; Vogelhuber, M.

    2015-11-01

    This comprehensive report published by the Swiss Federal Nuclear Safety Inspectorate ENSI presents an expert report published on the assessment of the geomechanical properties of intact Opalinus Clay. This review report addresses the conceptual constitutive framework for repositories in Opalinus Clay. The author addresses the geomechanical fundamentals that are necessary in order to adequately judge experiments on intact Opalinus Clay and the interpretation of the results. The report assesses in detail the various test series on intact Opalinus Clay carried out along with the interpretations made by experts and NAGRA. Further assessments are quoted including those on sample geometries tested, effective strength properties, undrained shear strength properties and elastic properties. The results of work done by other experts are also presented and discussed. The report is completed with a list of relevant literature

  4. Assessment of geomechanical properties of intact Opalinus Clay - Expert report

    Energy Technology Data Exchange (ETDEWEB)

    Amann, F. [Eidgenössische Technische Hochschule ETHZ, Zürich (Switzerland); Vogelhuber, M. [Dr. von Moos AG, Geotechnisches Büro, Zürich (Switzerland)

    2015-11-15

    This comprehensive report published by the Swiss Federal Nuclear Safety Inspectorate ENSI presents an expert report published on the assessment of the geomechanical properties of intact Opalinus Clay. This review report addresses the conceptual constitutive framework for repositories in Opalinus Clay. The author addresses the geomechanical fundamentals that are necessary in order to adequately judge experiments on intact Opalinus Clay and the interpretation of the results. The report assesses in detail the various test series on intact Opalinus Clay carried out along with the interpretations made by experts and NAGRA. Further assessments are quoted including those on sample geometries tested, effective strength properties, undrained shear strength properties and elastic properties. The results of work done by other experts are also presented and discussed. The report is completed with a list of relevant literature.

  5. Water Retention Curves of Opalinus Clay

    Energy Technology Data Exchange (ETDEWEB)

    Villar, M. V.; Romero, F. J.

    2012-11-01

    The water retention curve of Opalinus clay samples was determined under different conditions: total and matric suction, stress or no-stress conditions, wetting and drying paths. Through the fitting of these results to the van Genuchten expression the P parameter, related to the air entry value (AEV), was obtained. The AEV is the suction value above which air is able to enter the pores of the sample, and consequently, above which 2-phase flow can take place in the soil pore structure. The samples used in this research came from two different boreholes, BHT-1 and BHG-D1, but the behaviour of them did not depend on their location, what was probably due to the fact that both were drilled in the shay facies of the Opalinus clay. There was not a distinct difference between the results obtained under total or matric suctions. In the drying paths, both the water contents and the degrees of saturation tended to be higher when total suction was applied, however the reverse trend was observed for the water contents reached in wetting paths. As well, no clear difference was observed in the water retention curves obtained in odometers under matric and total suctions, what points to the osmotic component of suction in Opalinus clay not being significant. Overall, the water contents were lower and the degrees of saturation higher when suction was applied under vertical stress, what would indicate that the water retention capacity was lower under 8 MPa vertical stress than under free volume conditions. This vertical stress value is slightly higher than the maximum in situ stress. Also, the samples showed hysteresis according to the expected behaviour, i.e. the water contents for a given suction were higher during a drying path than during a wetting path. The P values obtained were between 6 and 34 MPa, and tended to be higher for the samples tested under stress, in drying paths and when total suction was used. The air entry value calculated from the mercury intrusion porosimetry

  6. Water Retention Curves of Opalinus Clay

    International Nuclear Information System (INIS)

    Villar, M. V.; Romero, F. J.

    2012-01-01

    The water retention curve of Opalinus clay samples was determined under different conditions: total and matric suction, stress or no-stress conditions, wetting and drying paths. Through the fitting of these results to the van Genuchten expression the P parameter, related to the air entry value (AEV), was obtained. The AEV is the suction value above which air is able to enter the pores of the sample, and consequently, above which 2-phase flow can take place in the soil pore structure. The samples used in this research came from two different boreholes, BHT-1 and BHG-D1, but the behaviour of them did not depend on their location, what was probably due to the fact that both were drilled in the shay facies of the Opalinus clay. There was not a distinct difference between the results obtained under total or matric suctions. In the drying paths, both the water contents and the degrees of saturation tended to be higher when total suction was applied, however the reverse trend was observed for the water contents reached in wetting paths. As well, no clear difference was observed in the water retention curves obtained in odometers under matric and total suctions, what points to the osmotic component of suction in Opalinus clay not being significant. Overall, the water contents were lower and the degrees of saturation higher when suction was applied under vertical stress, what would indicate that the water retention capacity was lower under 8 MPa vertical stress than under free volume conditions. This vertical stress value is slightly higher than the maximum in situ stress. Also, the samples showed hysteresis according to the expected behaviour, i.e. the water contents for a given suction were higher during a drying path than during a wetting path. The P values obtained were between 6 and 34 MPa, and tended to be higher for the samples tested under stress, in drying paths and when total suction was used. The air entry value calculated from the mercury intrusion porosimetry

  7. Strengthening and stress relaxation of Opalinus Clay

    International Nuclear Information System (INIS)

    Schulze, Otto

    2010-01-01

    Document available in extended abstract form only. Full text follows: In the framework of the EU-project NF-PRO (e.g. RTDC-5, Synthesis Report, D-No 5.2.3), special emphasis was put on the investigation and modelling of near-field processes in a candidate host rock: http://project.nf-pro.org/workspaces/rtdc5/deliverables/d5_2_3_rtdc_5_synthesis_report_final_version. The coupled TMHC-processes under consideration mainly concern the interaction between the host rock in and near to the EDZ and the waste products in its immediate vicinity. With respect to long-term safety analyses, there is no doubt that a sound process understanding is required. However, safe disposal also requires a suitable multi-barrier-system. This has to consist of technical and geo-technical barriers (e.g. container and backfill) but also of a strong geological barrier. Comparing the self-sealing capacity of the candidate host rocks, i.e. salt, clay and crystalline rock formations, where underground rooms will be inevitably backfilled only in part for technical reasons, in a salt formation convergence by viscous deformation provokes the re-establishing of a tight system, whereas in a crystalline rock formation long-term isolation has to be guaranteed solely by the technical and geotechnical components. This work is concentrated on the question, whether convergence and reduction of open space by long-term creep will take place also in a clay-stone formation, where laboratory investigation on Opalinus Clay from the Mont Terri Rock Laboratory was performed for this purpose. Several results from the work on the long-term deformation behaviour of clay-stone exist already. Nevertheless, to the author's knowledge the sound proof of a time-dependent and non-dilatant viscous deformation in the undisturbed far-field of clay-stone is still missing. Results from the rock laboratory at the Mt. Terri site yield hints for an anisotropic state of in-situ stresses, which may continue to exist in the

  8. Frugivory by the fish Brycon hilarii (Characidae) in western Brazil

    Science.gov (United States)

    Reys, Paula; Sabino, José; Galetti, Mauro

    2009-01-01

    Frugivory and seed dispersal have been poorly studied in Neotropical freshwater fishes. We studied frugivory and seed dispersal by the piraputanga fish ( Brycon hilarii, Characidae) in the Formoso River, Bonito, western Brazil. We examined the stomach contents of 87 fish and found the diet of piraputanga consisted of 24% animal prey (arthropods, snails, and vertebrates), 31% seeds/fruits and 45% other plant material (algae/macrophytes/leaves/flowers). The piraputangas fed on 12 fruit species, and were considered as seed dispersers of eight species. Fruits with soft seeds larger than 10 mm were triturated, but all species with small seeds (e.g. Ficus, Psidium) and one species with large hard seed ( Chrysophyllum gonocarpum) were dispersed. Piraputangas eat more fruits in the dry season just before the migration, but not during the spawning season. Fish length had a positive relation with the presence of fruits in their guts. The gallery forest of the Formoso River apparently does not have any plant species that depend exclusively on B. hilarii for seed dispersal because all fruit species are also dispersed by birds and mammals. Based on seed size and husk hardness of the riparian plant community of Formoso River, however, the piraputangas may potentially disperse at least 50% of the riparian fleshy fruit species and may be particularly important for long-distance dispersal. Therefore, overfishing or other anthropogenic disturbances to the populations of piraputanga may have negative consequences for the riparian forests in this region.

  9. Cephalopods in the diets of four shark species ( galeocerdo Cuvier ...

    African Journals Online (AJOL)

    The cephalopod components of the diets of four species of shark, tiger Galeocerdo cuvier, smooth hammerhead Sphyrna zygaena, scalloped hammerhead S. lewini and great hammerhead S. mokarran, were examined to reveal patterns of prey choice. Although these sharks were caught in the inshore gillnets used in ...

  10. Latitudinal variation in Atlantic Salpa fusiformis Cuvier, 1804 (Tunicata, Thaliacea)

    NARCIS (Netherlands)

    Soest, van R.W.M.

    1972-01-01

    The existence of clinal variation in some morphological characters of Atlantic Salpa fusiformis Cuvier, 1804, is reported. The number of muscle fibres of both aggregate and solitary individuals is subjected to a decrease from higher to lower latitudes. Size and reproduction also seem to vary

  11. Food and Feeding Habits of Catfish (Synodontis nigrita Cuvier And ...

    African Journals Online (AJOL)

    acer

    ABSTRACT:The food and feeding habits of Synodontis nigrita (Cuvier and Valenciennes) from. River Rima were ... (2005) studied the food habits of. Synodontis ... Phytoplankton families, Chlorophyceae and ... with r values of almost 1 in all the regression equations. ... often influences gut length (Smith, 1980). Perhaps the ...

  12. Los taxones como tipos: Buffon, Cuvier y Lamarck Taxa as types: Buffon, Cuvier and Lamarck

    Directory of Open Access Journals (Sweden)

    Gustavo Caponi

    2011-03-01

    Full Text Available Darwinianamente, los grupos taxonómicos son entendidos como entidades históricas que surgen en un momento de la evolución y que siempre pueden desaparecer. Pero esos grupos también fueron entendidos por muchos naturalistas como clases naturales; es decir, como tipos permanentes, a-históricos. Es mi interés señalar algunas de las formas que ese pensamiento tipológico de hecho ha tomado, subrayando que la adopción de esa perspectiva tipológica, además de no responder a compromisos teológicos, tampoco tiene porqué obedecer a la adopción de una ontología que pueda estar en conflicto con la ciencia natural. Analizaré así el modo en el que Buffon entendió las especies y el modo en los que Cuvier y Lamarck entendieron los órdenes taxonómicos superiores.From a Darwinian point of view, taxonomic groups are understood as historical entities that arise at an evolutionary moment and that can always disappear. But these groups were also understood by many naturalists as natural kinds; in other words, as permanent, ahistorical types. I will explore some of the forms that this typological thought took, showing that this typological perspective neither depends on theological beliefs, nor obeys the adoption of an ontology that might contradict natural science. Thus I shall analyze Buffon's understanding of species and the ways in which Cuvier and Lamarck understood the higher taxonomic orders.

  13. Embryonic and larval development of Brycon amazonicus (SPIX & AGASSIZ, 1829

    Directory of Open Access Journals (Sweden)

    A. C. S. Sampaio Nakauth

    Full Text Available Abstract The objective of this study was to describe the embryonic and larval development of Brycon amazonicus, featuring the main events up to 50 hours after fertilization (AF. The material was provided by the Aquaculture Training, Technology and Production Center, Presidente Figueiredo (AM. The characterization was based on stereomicroscopic examination of the morphology of eggs, embryos and larvae and comparison with the literature. Matrinxã eggs are free, transparent, and spherical, with a perivitelline space of 0.56 ± 0.3 mm. The successive divisions give rise to cells with 64 blastomeres during the first hour AF. The gastrula stage, beginning 02 h 40 min AF, was characterized by progressive regression cells and the formation of the embryonic axis, leading to differentiation of the head and tail 05 h 30 min AF. From 06 to 09 h AF the somites, notochord, otic and optic vesicles and otoliths were observed, in addition to heart rate and the release of the tail. The larvae hatched at 10 h 30 min AF (29.9 °C, with a total length of 3.56 ± 0.46 mm. Between 19 and 30 h AF, we observed 1 pigmentation and gut formation, 2 branchial arches, 3 pectoral fins, 4 a mouth opening and 5 teeth. Cannibalism was initiated earlier (34 h AF which was associated with rapid yolk absorption (more than 90% until 50 h AF, signaling the need for an exogenous nutritional source. The environmental conditions (especially temperature influenced the time course of some events throughout the embryonic and larval development, suggesting the need for further studies on this subject.

  14. Effect of water velocity on intermediary metabolism of juvenile matrinxã fish (Brycon amazonicus)

    OpenAIRE

    Arbeláez-Rojas, Gustavo Alberto; Moraes, Gilberto

    2013-01-01

    Background: determination of water velocity for optimum fish growth is fundamental since its duration and intensity can interfere with the metabolic preference for some biochemical paths, resulting in the use of specific substrates for fish growth. Objective: the purpose of this study was to assess the metabolic adjustments of juvenile matrinxã (Brycon amazonicus) reared under various sustained swimming conditions (SS). Methods: fish were subjected to SS for 90 days at five swimming speeds: 0...

  15. Project Opalinus Clay: Sorption Data Bases For Opalinus Clay Influenced By A High pH Plume

    Energy Technology Data Exchange (ETDEWEB)

    Bradbury, M.H.; Baeyens, B

    2004-11-01

    The interaction of groundwater with the large quantities of cement/concrete used in the construction and backfilling of emplacement tunnels containing long-lived intermediate level radioactive waste may give rise to the release of a pulse of hyper alkaline fluid (pH plume) into the surrounding rock. Since the pH of this plume could remain in excess of 12.5 for tens of thousands of years, many minerals in a sedimentary host rock would be unstable leading to dissolution reactions, secondary mineral precipitation and changes in groundwater chemistry. An Opalinus day formation in the Zuercher Weinland, is under consideration by Nagra as a potential host rock for a repository of spent fuel (SF), vitrified high-level waste (HLW) from reprocessing of spent fuel and long-lived intermediate-Ievel radioactive waste (ILW). The purpose of this report is to assess the effects of the interactions between a pH plume and Opalinus day on the sorption properties of the formation and to provide appropriate sorption data bases. (author)

  16. Complete mitochondrial genome of the tiger shark Galeocerdo cuvier (Carcharhiniformes: Carcharhinidae).

    Science.gov (United States)

    Chen, Xiao; Yu, Junqi; Zhang, Saile; Ding, Wenyong; Xiang, Dan

    2014-12-01

    The tiger shark Galeocerdo cuvier is the only member of the genus Galeocerdo. The complete mitochondrial genome of G. cuvier is presented for the first time in this study. The gene composition and arrangement in the mitogenome of G. cuvier is identical to most animal mitogenome. There are 22 bp short noncoding sequences and 44 bp overlaps in the mitogenome. The overall base composition is 31.8% A, 23.9% C, 13.0% G and 31.3% T. The dihydrouridine arm of tRNA-Ser2 was replaced by a simple loop and the other tRNAs could be folded into the typical cloverleaf structure.

  17. Diet and trophic ecology of the tiger shark (Galeocerdo cuvier from South African waters.

    Directory of Open Access Journals (Sweden)

    Matthew L Dicken

    Full Text Available Knowledge of the diet and trophic ecology of apex predators is key for the implementation of effective ecosystem as well as species-based management initiatives. Using a combination of stomach content data and stable isotope analysis (δ15N and δ13C the current study provides information on size-based and sex-specific variations in diet, trophic position (TP and foraging habitat of tiger sharks (Galeocerdo cuvier caught in the KwaZulu-Natal Sharks Board bather protection program. This study presents the longest time-series and most detailed analysis of stomach content data for G. cuvier worldwide. Prey identified from 628 non-empty stomachs revealed a size-based shift in diet. Reptiles, birds, mysticetes, and large shark species increased in dietary importance with G. cuvier size, concomitant with a decrease in smaller prey such as batoids and teleosts. Seasonal and decadal shifts in diet driven primarily by changes in the importance of elasmobranchs and mammal (cetacean prey were recorded for medium sized (150-220 cm G. cuvier. Both stomach content and stable isotope analysis indicated that G. cuvier is a generalist feeder at the population level. Size-based δ13C profiles indicated a movement to offshore foraging habitats by larger G. cuvier. Calculated TP varied by method ranging from 4.0 to 5.0 (TPSCA for stomach contents and from 3.6 to 4.5 (TPscaled and TPadditive for δ15N. Large (> 220 cm G. cuvier did not feed at discrete trophic levels, but rather throughout the food web. These data provide key information on the ecological role of G. cuvier to improve the accuracy of regional food web modelling. This will enable a better understanding of the ecological impacts related to changes in the abundance of this predator.

  18. Genetic evidence of population structuring in the neotropical freshwater fish Brycon hilarii (Valenciennes, 1850

    Directory of Open Access Journals (Sweden)

    A Sanches

    Full Text Available Brycon hilarii is a migratory fish widely distributed throughout the Paraguay River Basin. It is appreciated in sport fishing and for its superior meat quality. It is also the main species for tourist attraction in the Bonito region (State of Mato Grosso do Sul, Brazil. Considering the lack of information on the genetic structure of the fish of this species, the aim of the present study was to detect the genetic variability of Brycon hilarii through RAPD markers. A total of eighty specimens collected in different seasons at four sites of the Miranda River sub-basin (Paraguay River Basin, Brazil were used for analysis. The results of genetic similarity, Shannon diversity, and AMOVA revealed differences between the sampling sites. Through AMOVA, differences between populations were more evident among the animals collected during the non-reproductive season, corresponding to a time of less movement of these fish. A population structuring model in which B. hilarii appears organized into genetically differentiated reproductive units that coexist and co-migrate through the studied system was suggested, contrasting the currently accepted idea that freshwater migratory fish form large panmictic populations in a determined hydrographic system. Despite the lack of a complete picture regarding the distribution of B. hilarii in the studied region, this initial idea on its population genetic structure could be an important contribution to providing aid for management and conservation programs of these fish.

  19. Caracterización citogenética del pez neotropical Brycon henni (Pisces: Characidae

    Directory of Open Access Journals (Sweden)

    Diana David López

    2008-12-01

    Full Text Available La sabaleta Brycon henni, es un pez nativo del occidente colombiano importante para la seguridad alimentaria de las poblaciones ribereñas y para la pesca deportiva por sus característica combativas. El desarrollarse entre los 18 y 28ºC la convierte en una especie de cultivo promisoria. Un estudio citogenético a partir de células branquiales indicó diferentes complementos cromosómicos. Este trabajo aplicó la técnica de cultivo de linfocitos a muestras de sangre de adultos. Las muestras de sangre total fueron sembradas en 4 ml de medio de cultivo Ham-F12, suplementado con 0.5 ml de Suero Fetal Bovino y 0.7 ml del mitógeno Fitohemaglutinina M (Gibco® durante 96 hr a 28ºC; 1.5 hr antes de la cosecha agregamos 100µl de Colcemid al 10% como factor antimitótico. Cada cultivo se incubó con 10 ml de solución hipotónica KCl 0.56% por 24 min a 37ºC, para continuar con tres fijaciones sucesivas, centrifugaciones y tinción Giemsa al 5%. Las mejores metafases fueron fotografiadas en microscopio, correspondientes a 6 machos y 8 hembras, indicando un número diploide de 50 cromosomas, clasificados en Metacéntricos (26M, Submetacéntricos (16SM y Subtelocéntricos (8ST, para un número fundamental (NF de 100 brazos. La tendencia evolutiva hallada fue de tipo B; no se encontraron cromosomas supernumerarios pero sí un primer par de cromosomas metacéntricos grandes, considerado marcador para el género Brycon, no determinante de heteromorfismo sexual. Estos resultados coinciden con los demás bricónidos investigados, en donde se podría considerar un ancestro común con un número cromosómico básico y cariotipos simétricos.Cytogenetic characterization of the neotropical fish Brycon henni (Pisces: Characidae. Brycon henni, is a native fish from Western Colombia is important as food and in sport fishing, and could be cultured in waters between 18 and 28ºC. A previous cytogenetic study in branchial cells indicated different chromosomal

  20. Speciation of neptunium after diffusion in Opalinus Clay

    Energy Technology Data Exchange (ETDEWEB)

    Reich, Tobias; Amayri, Samer; Drebert, Jakob; Froehlich, Daniel R.; Grolimund, Daniel; Rosemann, Jonathan [Mainz Univ. (Germany). Inst. of Nuclear Chemistry; Kaplan, Ugras [Paul Scherrer Institut, Villigen (Switzerland). Swiss Light Source

    2015-07-01

    Argillaceous rock formations are under consideration as a potential host rock for the construction of high-level nuclear waste repositories. Under environmental conditions the most stable oxidation states of {sup 237}Np (t{sub 1/2}=2.1 x 10{sup 6} a) are Np(IV) and Np(V). We have investigated the sorption and diffusion of the more mobile Np(V) in Opalinus Clay (OPA, Mont Terri, Switzerland) (Wu et al. 2009, Froehlich et al. 2011 and 2012 a). OPA, which is present in Switzerland and southern Germany, possesses a micro-scale heterogeneity and is composed of several types of clay minerals, but also of calcite, quartz and iron(II)-bearing minerals. In our previous diffusion (Wu et al. 2009) and anaerobic sorption experiments (Froehlich et al. 2011), we observed higher distribution coefficients, K{sub d}, than expected from batch experiments performed in air, indicating that a partial reduction of Np(V) to Np(IV) had occurred. To test this hypothesis, different sorption and diffusion samples with Np(V) were prepared at pH 7.6 for spatially resolved molecular-level investigations at the microXAS beamline at the Swiss Light Source (PSI, Villigen, Switzerland) (Froehlich et al. 2012 b). Elemental distributions of Ca, Fe and Np have been determined by μ-XRF mapping. Regions of high Np concentration were subsequently investigated by Np L{sub III}-edge μ-XANES. In most samples Np spots with considerable amounts of tetravalent Np could be found, even when the experiments were performed under ambient-air conditions. In some cases, almost pure Np(IV) L{sub III}-edge XANES spectra were recorded. In case of the anaerobic sorption sample, a clear correlation between Np and Fe was observed by μ-XRF, indicating that iron(II)-bearing minerals could be responsible for the reduction of Np(V). μ-XRD measurements of this sample showed that pyrite is at least one of the redox-active phases determining the speciation of Np in OPA. In this case, Np was accumulated on pyrite, indicating

  1. Frictional Properties of Opalinus Clay: Implications for Nuclear Waste Storage

    Science.gov (United States)

    Orellana, L. F.; Scuderi, M. M.; Collettini, C.; Violay, M.

    2018-01-01

    The kaolinite-bearing Opalinus Clay (OPA) is the host rock proposed in Switzerland for disposal of radioactive waste. However, the presence of tectonic faults intersecting the OPA formation put the long-term safety performance of the underground repository into question due to the possibility of earthquakes triggered by fault instability. In this paper, we study the frictional properties of the OPA shale. To do that, we have carried out biaxial direct shear experiments under conditions typical of nuclear waste storage. We have performed velocity steps (1-300 μm/s) and slide-hold-slide tests (1-3,000 s) on simulated fault gouge at different normal stresses (4-30 MPa). To establish the deformation mechanisms, we have analyzed the microstructures of the sheared samples through scanning electron microscopy. Our results show that peak (μpeak) and steady state friction (μss) range from 0.21 to 0.52 and 0.14 to 0.39, respectively, thus suggesting that OPA fault gouges are weak. The velocity dependence of friction indicates a velocity strengthening regime, with the friction rate parameter (a - b) that decreases with normal stress. Finally, the zero healing values imply a lack of restrengthening during interseismic periods. Taken together, if OPA fault reactivates, our experimental evidence favors an aseismic slip behavior, making the nucleation of earthquakes difficult, and long-term weakness, resulting in stable fault creeping over geological times. Based on the results, our study confirms the seismic safety of the OPA formation for a nuclear waste repository.

  2. Comparative study of methods to estimate hydraulic parameters in the hydraulically undisturbed Opalinus Clay (Switzerland)

    Energy Technology Data Exchange (ETDEWEB)

    Yu, C.; Matray, J.-M. [Institut de Radioprotection et de Sûreté Nucléaire, Fontenay-aux-Roses, (France); Yu, C.; Gonçalvès, J. [Aix Marseille Université UMR 6635 CEREGE Technopôle Environnement Arbois-Méditerranée Aix-en-Provence, Cedex 4 (France); and others

    2017-04-15

    The deep borehole (DB) experiment gave the opportunity to acquire hydraulic parameters in a hydraulically undisturbed zone of the Opalinus Clay at the Mont Terri rock laboratory (Switzerland). Three methods were used to estimate hydraulic conductivity and specific storage values of the Opalinus Clay formation and its bounding formations through the 248 m deep borehole BDB-1: application of a Poiseuille-type law involving petrophysical measurements, spectral analysis of pressure time series and in situ hydraulic tests. The hydraulic conductivity range in the Opalinus Clay given by the first method is 2 × 10{sup -14}-6 × 10{sup -13} m s{sup -1} for a cementation factor ranging between 2 and 3. These results show low vertical variability whereas in situ hydraulic tests suggest higher values up to 7 × 10{sup -12} m s{sup -1}. Core analysis provides economical estimates of the homogeneous matrix hydraulic properties but do not account for heterogeneities at larger scale such as potential tectonic conductive features. Specific storage values obtained by spectral analysis are consistent and in the order of 10{sup -6} m{sup -1}, while formulations using phase shift and gain between pore pressure signals were found to be inappropriate to evaluate hydraulic conductivity in the Opalinus Clay. The values obtained are globally in good agreement with the ones obtained previously at the rock laboratory. (authors)

  3. Anisotropic Behaviour of Opalinus Clay Through Consolidated and Drained Triaxial Testing in Saturated Conditions

    Science.gov (United States)

    Favero, Valentina; Ferrari, Alessio; Laloui, Lyesse

    2018-05-01

    This paper investigates the anisotropic hydro-mechanical behaviour of Opalinus Clay shale, the host material currently being considered for the construction of a nuclear waste repository in Switzerland. Consolidated and drained triaxial tests on Opalinus Clay from the Mont Terri URL have been conducted in order to derive information on its strength and stiffness properties. Opalinus Clay specimens were tested both parallel to bedding (P-specimens) and perpendicular to bedding (S-specimens). The considered effective confining stress range (from 2 to 12 MPa) has been selected in order to reproduce possible in situ stress conditions for the repository. In this work, particular attention has been paid to the experimental procedure in order to ensure consolidated conditions and avoid generation of unwanted excess pore water pressure during drained shearing. The Skempton B parameter has been determined for all the tested specimens in order to ensure saturation. Both single-stage and multistage triaxial testing procedures were adopted in the experimental campaign. The results of the triaxial tests highlight an anisotropic elastic response of Opalinus Clay: S-specimens present a more compliant behaviour than P-specimens. The values of the Young modulus are found to increase with the increase in mean effective stress. The analysis of the peak and ultimate shear strength results reveals that the material behaves in a similar manner regardless of the considered direction of loading (P and S directions) with respect to the bedding orientation. Peak and ultimate failure envelopes for Opalinus Clay were derived for the investigated stress range.

  4. Milt quality and spermatozoa morphology of captive Brycon siebenthalae (Eigenmann) broodstock

    DEFF Research Database (Denmark)

    Cruz-Casallas, Pablo E.; Lombo-Rodríguez, Dora A.; Velasco-Santamaría, Yohana M.

    2005-01-01

    collected for each male was 1.8 mL and the sperm concentration was 13.99 spermatozoa/mL. Spermatocrit (41.5%) was positively associated (r2: 0.30) with sperm density calculated using a corpuscle counting chamber. Sperm motility was 88% and the average duration of forward motility was 41 s. Fertilization......In order to develop artificial reproduction in freshwater fish for potential species to be developed in South American aquaculture, milt quality and sperm morphology were studied in yamu (Brycon siebenthalae) under captive conditions during the natural middle spermiation period. The volume of milt...... rate was 84% and there was no association between this trait and sperm motility (r2: 0.009) or with sperm density (r2: 0.073). These results suggest that captive B. siebenthalae broodstock can be reproduced successfully....

  5. Mont Terri project, cyclic deformations in the Opalinus Clay

    International Nuclear Information System (INIS)

    Moeri, A.; Bossart, P.; Matray, J.M.; Mueller, H.; Frank, E.

    2010-01-01

    Document available in extended abstract form only. Shrinkage structures in the Opalinus Clay, related to seasonal changes in temperature and humidity, are observed on the tunnel walls of the Mont Terri Rock Laboratory. The structures open in winter, when relative humidity in the tunnel decreases to 65%. In summer the cracks close again because of the increase in the clay volume when higher humidity causes rock swelling. Shrinkage structures are monitored in the Mont Terri Rock Laboratory at two different sites within the undisturbed rock matrix and a major fault zone. The relative movements of the rock on both sides of the cracks are monitored in three directions and compared to the fluctuations in ambient relative humidity and temperature. The cyclic deformations (CD) experiment aims to quantify the variations in crack opening in relation to the evolution of climatic conditions and to identify the processes underlying these swell and shrinkage cycles. It consists of the following tasks: - Measuring and quantifying the long-term (now up to three yearly cycles) opening and closing and, if present, the associated shear displacements of selected shrinkage cracks along an undisturbed bedding plane as well as within a major fault zone ('Main Fault'). The measurements are accompanied by temperature and humidity records as well as by a long-term monitoring of tunnel convergence. - Analysing at the micro-scale the surfaces of the crack planes to identify potential relative movements, changes in the rock fabric on the crack surfaces and the formation of fault gouge material as observed in closed cracks. - Processing and analysing measured fluctuations of crack apertures and rock deformation in the time series as well as in the hydro-meteorological variables, in particular relative humidity Hr(t) and air temperature. - Studying and reconstructing the opening cycles on a drill-core sample under well-known laboratory conditions and observing potential propagation of

  6. Speciation of plutonium during sorption and diffusion in Opalinus clay

    International Nuclear Information System (INIS)

    Kaplan, Ugras

    2013-01-01

    The presented work was carried out in the framework of the BMWi-project ''Interaction and migration of actinides in natural clay rocks taking into account humic substances and clay organic matter - Interactions of neptunium and plutonium with natural clay rocks''. For the long-term safety assessments of nuclear repositories, the possible migration of the radiotoxic wastes into the environment must be considered. Due to its long half-life (T 1/2 = 24000 y) 239 Pu has a significant contribution to the radiotoxicity of spent nuclear fuel in a repository after long periods of storage. The redox-sensitive plutonium has a very complicated chemical behavior. In aqueous solution under environmental relevant conditions Pu can exist in oxidation states +III to +VI and it can exist in up to four oxidation states simultaneously in a solution. Clays are considered as a possible host rock formation for of high-level radioactive waste disposal. Therefore, detailed information on the mobilization and immobilization of plutonium through / into the groundwater from a repository are of special interest. In this work new insights into the interaction between Pu and natural Opalinus clay (OPA, Mont Terri, Switzerland) are obtained with regard to the disposal of heat-generating radioactive waste in a deep geological repository.rnThe focus of this work was on the determination of the speciation of Pu on the mineral surface after sorption and diffusion process by different synchrotron based techniques (μ-XRF, μ-XANES/-EXAFS, μ-XRD, and EXAFS/XANES). The interaction between Pu and OPA was studied in batch sorption and diffusion experiments in dependence of various experimental parameters (e.g. pH, Pu oxidation state). Sorption experiments showed that some experimental parameters (e.g. temperature, humic acid) have a significant impact on the sorption of Pu on OPA. Speciation studies were performed as a function of various chemical parameters on powder samples form batch experiments as

  7. The Mont Terri rock laboratory: International research in the Opalinus Clay

    International Nuclear Information System (INIS)

    Bossart, P.

    2015-01-01

    This article reports on a visit made to the rock laboratory in Mont Terri, Switzerland, where research is being done concerning rock materials that can possibly be used for the implementation of repositories for nuclear wastes. Emphasis is placed on the project’s organisation, rock geology and on-going experiments. International organisations also involved in research on nuclear waste repositories are listed. The research facilities in tunnels built in Opalinus Clay at the Mont Terri site are described. The geology of Opalinus Clay and the structures found in the research tunnels are discussed, as is the hydro-geological setting. The research programme and various institutions involved are listed and experiments carried out are noted. The facilities are now also being used for research on topics related to carbon sequestration

  8. Clay shale as host rock. A geomechanical contribution about Opalinus clay

    International Nuclear Information System (INIS)

    Lempp, Christof; Menezes, Flora; Sachwitz, Simon

    2016-01-01

    The Opalinuston is a prominent rock representing the type of organic clay shales or clay stones within the sequence of Triassic and Jurassic marine sediments in Southern Germany. The rock forms a homogenous unit some ten meters thick. The degree of consolidation of this type of pelitic rock depends mainly on the former load conditions, but is also dependent on the long-term weathering and even on the present exposition. The geomechanical parameters such as shear strength, tensional strength and permeability vary with the state of consolidation and become important when the use is discussed of such rocks for radioactive waste disposal. A tunneling project at the northern escarpment of the Swabian Alb (Southwest Germany) within the Opalinus clay offered the rare opportunity to obtain fresh unweathered rock samples in greater amounts compared to fresh drilling cores from which geomechanical investigations are usually undertaken. Consequently, the results of geomechanical laboratory testings are presented in order to compare here the results of multistep triaxial compression tests, of hydraulic fracturing laboratory tests and of some other tests for rock characterization with the corresponding results of Opalinus clay sites in Switzerland that were investigated by the Swiss Nagra Company for host rock characterization. After a discussion of the relevant state of fresh Opalinus clay, especially of suction pressure conditions and saturation state, the results of triaxial shear tests are presented. Increasing shear deformation at increasing pressure and unchanged water saturation do not result in a significant strength reduction of the Opalinus clay. The rock shows increasing cohesion and stiffness, if multiple loading has repeatedly reached the failure point. Thus there is no increased permeability with continued shearing. Only at the beginning of the shearing process is a temporarily increased permeability to be expected due to dilatation processes. An increased

  9. Mineralogical and Micro-fabric investigation of the Sandy Facies of Opalinus Clay (Mont Terri)

    International Nuclear Information System (INIS)

    Kaufhold, Annette; Siegesmund, Siegfried; Dohrmann, Reiner; Graesle, Werner; Plischke, Ingo

    2013-01-01

    In the field of geological disposal of radioactive waste in many countries argillaceous formations are considered as potential host rock. For the understanding of the long-term behaviour of clay host rock, it is important to understand the interaction between mechanical behaviour, micro-fabric, and mineral composition. Previous publications showed that particularly the carbonate content and the arrangement of the carbonate grains (as cement in the matrix or as shells) determines the mechanical strength of Opalinus Clay and Callovo-Oxfordian Clay specimens, respectively. Klinkenberg et al. (2009) studied the shaly facies of Opalinus Clay, however, the actual deposit is planned to be built in the sandy facies of Opalinus Clay. The aim of the present study is to investigate the relation between micro-fabric, mineral composition, and mechanical properties of different samples derived from the sandy facies (BLT-A2). Image analysis showed that the carbonates in the sandy facies mainly occur as 1) matrix which in turn acts as cement. Carbonates also occur 2) in the fine sand fraction and 3) biogenic carbonates as traces. The carbonates of the sandy facies, therefore, appear to be similar to the carbonates of the Callovo-Oxfordian Clay with respect to their possible influence on failure strength. The mechanical testing showed that the shear strength increases with increasing carbonate content. This phenomenon was also observed for the samples of the Callovo-Oxfordian Clay, while the opposite relation was found for the shaly facies of the Opalinus Clay. Preliminary results presented here, indicate that the sandy facies (drilling BLT-A2) and Callovo-Oxfordian Clay show similar mechanical properties - in detail: 1) Micro-fabric: carbonates predominate in the matrix, 2) Mineralogy: high carbonate content and 3) Mechanical testing: shear strength increases with increasing carbonate content, where the type of carbonates which controls the increase of strength has to be

  10. Microbial diversity in opalinus clay and interaction of dominant microbial strains with actinides

    International Nuclear Information System (INIS)

    Moll, Henry; Luetke, Laura; Bachvarova, Velina; Steudtner, Robin; Geissler, Andrea; Krawczyk-Baersch, Evelyn; Selenska-Pobell, Sonja; Bernhardt, Gert

    2013-01-01

    For the first time microbial tDNA could be isolated from 50 g unperturbed Mont Terri Opalinus Clay. Based on the analysis of the tDNA the bacterial diversity of the unperturbed clay is dominated by representatives of Firmicutes, Betaproteobacteria, and Bacteriodetes. Firmicutes also dominate after treatment of the clay with R2A medium. Bacteria isolated from Mont Terri Opalinus Clay on R2A medium were related to Sporomusa spp., Paenibacillus spp., and Clostridium spp. All further investigations are concentrated on the unique isolates Sporomusa sp. MT-2 and Paenibacillus sp. MT-2. Cells of the type Sporomusa sp. MT-2 and Paenibacillus sp. MT-2 were comprehensively analyzed in terms of growing, morphology, functional groups of the cell envelope, and cell membrane structure. Strong actinide(An)/lanthanide(Ln)-interactions with the Opalinus Clay isolates and the Aespoe-strain Pseudomonas fluorescens (CCUG 32456) could be determined within a broad pH range (2-8). The metals bind as a function of pH on protonated phosphoryl, carboxyl and deprotonated phosphoryl sites of the respective cell membrane. The thermodynamic surface complexation constants of bacterial An/Ln-species were determined and can be used in modeling programs. Depending on the used An different interaction mechanisms were found (U(VI): biosorption, partly biomineralisation; Cm(III): biosorption, indications for embedded Cm(III); Pu: biosorption, bioreduction and indications for embedded Pu). Different strategies of coping with U(VI) were observed comparing P. fluorescens planktonic cells and biofilms under the chosen experimental conditions. An enhanced capability of the biofilm to form meta-autunite in comparison to the planktonic cells was proven. Conclusively, the P. fluorescens biofilm is more efficient in U(VI) detoxification. In conclusion, Mont Terri Opalinus Clay contains bacterial communities, that may influence the speciation and hence the migration behavior of selected An/Ln under

  11. Microbial diversity in opalinus clay and interaction of dominant microbial strains with actinides

    Energy Technology Data Exchange (ETDEWEB)

    Moll, Henry; Luetke, Laura; Bachvarova, Velina; Steudtner, Robin; Geissler, Andrea; Krawczyk-Baersch, Evelyn; Selenska-Pobell, Sonja; Bernhardt, Gert

    2013-07-01

    For the first time microbial tDNA could be isolated from 50 g unperturbed Mont Terri Opalinus Clay. Based on the analysis of the tDNA the bacterial diversity of the unperturbed clay is dominated by representatives of Firmicutes, Betaproteobacteria, and Bacteriodetes. Firmicutes also dominate after treatment of the clay with R2A medium. Bacteria isolated from Mont Terri Opalinus Clay on R2A medium were related to Sporomusa spp., Paenibacillus spp., and Clostridium spp. All further investigations are concentrated on the unique isolates Sporomusa sp. MT-2 and Paenibacillus sp. MT-2. Cells of the type Sporomusa sp. MT-2 and Paenibacillus sp. MT-2 were comprehensively analyzed in terms of growing, morphology, functional groups of the cell envelope, and cell membrane structure. Strong actinide(An)/lanthanide(Ln)-interactions with the Opalinus Clay isolates and the Aespoe-strain Pseudomonas fluorescens (CCUG 32456) could be determined within a broad pH range (2-8). The metals bind as a function of pH on protonated phosphoryl, carboxyl and deprotonated phosphoryl sites of the respective cell membrane. The thermodynamic surface complexation constants of bacterial An/Ln-species were determined and can be used in modeling programs. Depending on the used An different interaction mechanisms were found (U(VI): biosorption, partly biomineralisation; Cm(III): biosorption, indications for embedded Cm(III); Pu: biosorption, bioreduction and indications for embedded Pu). Different strategies of coping with U(VI) were observed comparing P. fluorescens planktonic cells and biofilms under the chosen experimental conditions. An enhanced capability of the biofilm to form meta-autunite in comparison to the planktonic cells was proven. Conclusively, the P. fluorescens biofilm is more efficient in U(VI) detoxification. In conclusion, Mont Terri Opalinus Clay contains bacterial communities, that may influence the speciation and hence the migration behavior of selected An/Ln under

  12. Anisotropic modelling of Opalinus Clay behaviour: From triaxial tests to gallery excavation application

    Directory of Open Access Journals (Sweden)

    François Bertrand

    2017-06-01

    Full Text Available Deep repository in geological formations is the preferential solution considered in many countries to manage high-level nuclear wastes. In Switzerland, the Opalinus Clay is a candidate host rock. In this context, in situ and laboratory tests are conducted on Opalinus Clay to demonstrate the feasibility of deep disposal in this argillaceous formation. This paper presents a constitutive model able to fit the experimental data obtained from some triaxial tests conducted by Jahns (2013 on cores from borehole Schlattingen SLA-1. The elasto-plastic behaviour of Opalinus Clay is reproduced thanks to a Drucker-Prager model, taking into account the anisotropy behaviour of this sedimentary rock. The objective is to employ a single set of parameters representative of the material. In a second version of the model, the stress-dependence of the elastic properties and damage are taken into account. Finally, the parameters calibrated with experimental tests are used to simulate the excavation of a gallery with a second gradient approach.

  13. Biometric observations of newborn Crocodylus acutus (Cuvier, 1807 obtained in captivity in, Tumbes, Peru

    Directory of Open Access Journals (Sweden)

    Oswaldo Pérez

    2013-05-01

    Full Text Available In this paper, length and weigth measurements of 20 newborn Crocodylus acutus (Cuvier, 1807 hached in a pilot farm-bred of the aquaculture center La Tuna Carranza, Puerto Pizarro, Tumbes, Peru, in 2001 are presented. The information is compared with similar reports from others places.

  14. Sustained swimming improves fish dietary nutrient assimilation efficiency and body composition of juvenile Brycon amazonicus

    Directory of Open Access Journals (Sweden)

    Gustavo Alberto Arbeláez-Rojas

    Full Text Available ABSTRACT Sustained swimming (SS usually promotes beneficial effects in growth and feed conversion of fishes. Although feed efficiency is improves at moderate water velocity, more information is required to determine the contributions of this factor on growth and body composition. Body composition and efficiency responses to the use of nutrients were determined in juvenile matrinxa Brycon amazonicus (Spix and Agassiz, 1829 fed with two dietary amounts of protein, 28 or 38% of crude protein (CP, and subjected to sustained swimming at a constant speed of 1.5 body lengths s−1 (BL s−1 or let to free swimming. The fish body composition under SS and fed with 28% of dietary protein showed 22% of increased in bulk protein and a 26% of decrease in water content in the white muscle. Red muscle depicted 70% less water content and a 10% more lipid. Nutrient retention was enhanced in fish subjected to SS and a higher gain of ethereal extract sustained was observed in the white muscle of exercised fish fed with 38% CP. The interaction between swimming and dietary protein resulted in a larger bulk of lipid in red muscle. Fish fed with 28% CP under SS at 1.5 BL s−1 presented the best utilization of dietary nutrients and body composition. Thus, this fish farming procedure is proposed as a promising management strategy for rearing matrinxa.

  15. Intermittent sustained swimming in 'matrinxã' Brycon amazonicus (Bryconidae: Bryconinae: hematological and metabolic responses

    Directory of Open Access Journals (Sweden)

    Fernando Fabrizzi

    Full Text Available In fish, studies on a wide variety of physiological effects of exercise have been reported since a long time. It has been attributed special attention to some types of exercise, however, its application as a healthful practice in the rearing and welfare of farming fish is rising in last few years. In this particular, long-term intermittent sustained swimming (ISS has been not yet explored. In this work, the freshwater fish Brycon amazonicus was submitted to (ISS for 30 days at velocity of 1.0 body-length sec-1 for 12h interspaced by 12h under still water. Hematology and metabolism were evaluated. Exercised fish decreased 30% the erythrocyte number and hemoglobin was unvaried. The stores of liver glycogen and muscular triacylglycerol (TAG were increased and the metabolic profile was typically aerobic. The slight decrease of liver (TAG plus the full metabolic and hematic trait allow investing in this kind of exercise a beneficial practice in the rearing of fish species

  16. Cryopreservation of yamú (Brycon amazonicus) sperm for large scale fertilization

    DEFF Research Database (Denmark)

    Velasco-Santamaría, Yohana M.; Medina-Robles, Mauricio; Cruz-Casallas, Pablo E.

    2006-01-01

      To determine the effect of straw size and thawing temperature on cryopreserved sperm quality of yamú (Brycon amazonicus), ovulation and spermiation were induced in sexually mature broodstock using Carp Pituitary Extract. Sperm quality was evaluated by motility, activation time and fertility...... assays consisted of 40 g eggs inseminated with approximately 5.0 mL (ca. 75,000 motile spermatozoa/egg) of cryopreserved sperm in large straws thawed at 35 °C. The fertilization rate was estimated 6 h post-insemination. In all straws, postthaw motility was significantly lower than for fresh sperm (pb0.......05) to sperm frozen in 0.5-mL straws (48±2%, 51±2%, 52±2% and 54±3%, respectively). In large scale fertilization trials, fresh sperm showed a higher (pb0.05) fertilization rate (83±1%) than frozen-thawed sperm (68±1%). Although the fertility percentage with fresh sperm was significantly higher than with frozen...

  17. Fish stock assessment of piraputanga Brycon microlepis in the Cuiabá River basin, Pantanal of Mato Grosso, Brazil

    Directory of Open Access Journals (Sweden)

    L. A. de F. MATEUS

    Full Text Available Fork length measurements of individuals of Brycon microlepis landed and commercialized at the Porto Market in Cuiabá, MT, from May-October 1996 to May-October 1997 were used to estimate growth and mortality parameters for this species. The average estimated populational parameters were: L¥ = 705 mm, k = 0.275 year--1, C = 0.775, WP = 0.465, Lc = 164 mm, M = 0.585 year--1, Z = 0.822 year--1, with F = 0.237 year--1. Yield per recruit analysis suggests that the stock is not yet overexploited.

  18. Fish stock assessment of piraputanga Brycon microlepis in the Cuiabá River Basin, Pantanal of Mato Grosso, Brazil.

    Science.gov (United States)

    Mateus, L A de F; Estupiñán, G M B

    2002-02-01

    Fork length measurements of individuals of Brycon microlepis landed and commercialized at the Porto Market in Cuiabá, MT, from May-October 1996 to May-October 1997 were used to estimate growth and mortality parameters for this species. The average estimated populational parameters were: L infinity = 705 mm, k = 0.275 year-1, C = 0.775, WP = 0.465, Lc = 164 mm, M = 0.585 year-1, Z = 0.822 year-1, with F = 0.237 year-1. Yield per recruit analysis suggests that the stock is not yet overexploited.

  19. The shale gas potential of the Opalinus Clay and Posidonia Shale in Switzerland - A first assessment

    Energy Technology Data Exchange (ETDEWEB)

    Leu, W. [Geoform Ltd, Villeneuve (Switzerland); Gautschi, A. [NAGRA, Wettingen (Switzerland)

    2014-07-01

    There has been recent interest in the shale gas potential of the Opalinus Clay and Posidonia Shale (Middle and Lower Jurassic) below the Swiss Molasse Basin in the light of the future role of domestic gas production within the expected future energy shift of Switzerland and possible conflicts in underground use. The Opalinus Clay of northern Switzerland is a potential host rock for repositories of both high-level and low-to-intermediate level radioactive waste and the exploitation of shale gas resources within or below this formation would represent a serious conflict of use. Well data from northern Switzerland shows that these two formations are unsuitable for future shale gas recovery. They never reached the gas window during their burial history (maturity values are ≤ 0.6% R{sub o}) and as a consequence never generated significant quantities of thermogenic gas. Geochemical data further shows that the average TOC values are in the range of 0.7%, i.e. clearly below accepted values of more than 1.5% for prospective shales. A review of available exploration data for the Opalinus Clay and Posidonia Shale in the deeper and western part of the Swiss Molasse Basin indicate that their shale gas potential may be substantial. The gross Posidonia Shale thickness increases from central Switzerland from less than 10 m to over 100 m in the Yverdon-Geneva area and is characterised by numerous bituminous intervals. A simplified shale gas resource calculation results for a geologically likely scenario in a technically recoverable gas volume of ∼120 billions m{sup 3}. The current database for such estimates is small and as a consequence, the uncertainties are large. However, these first encouraging results support a more detailed exploration phase with specific geochemical and petrophysical analysis of existing rock and well log data. (authors)

  20. The shale gas potential of the Opalinus Clay and Posidonia Shale in Switzerland - A first assessment

    International Nuclear Information System (INIS)

    Leu, W.; Gautschi, A.

    2014-01-01

    There has been recent interest in the shale gas potential of the Opalinus Clay and Posidonia Shale (Middle and Lower Jurassic) below the Swiss Molasse Basin in the light of the future role of domestic gas production within the expected future energy shift of Switzerland and possible conflicts in underground use. The Opalinus Clay of northern Switzerland is a potential host rock for repositories of both high-level and low-to-intermediate level radioactive waste and the exploitation of shale gas resources within or below this formation would represent a serious conflict of use. Well data from northern Switzerland shows that these two formations are unsuitable for future shale gas recovery. They never reached the gas window during their burial history (maturity values are ≤ 0.6% R o ) and as a consequence never generated significant quantities of thermogenic gas. Geochemical data further shows that the average TOC values are in the range of 0.7%, i.e. clearly below accepted values of more than 1.5% for prospective shales. A review of available exploration data for the Opalinus Clay and Posidonia Shale in the deeper and western part of the Swiss Molasse Basin indicate that their shale gas potential may be substantial. The gross Posidonia Shale thickness increases from central Switzerland from less than 10 m to over 100 m in the Yverdon-Geneva area and is characterised by numerous bituminous intervals. A simplified shale gas resource calculation results for a geologically likely scenario in a technically recoverable gas volume of ∼120 billions m 3 . The current database for such estimates is small and as a consequence, the uncertainties are large. However, these first encouraging results support a more detailed exploration phase with specific geochemical and petrophysical analysis of existing rock and well log data. (authors)

  1. Geomechanical behaviour of Opalinus Clay at multiple scales: results from Mont Terri rock laboratory (Switzerland)

    Energy Technology Data Exchange (ETDEWEB)

    Amann, F.; Wild, K.M.; Loew, S. [Institute of Geology, Engineering Geology, Swiss Federal Institute of Technology, Zurich (Switzerland); Yong, S. [Knight Piesold Ltd, Vancouver (Canada); Thoeny, R. [Grundwasserschutz und Entsorgung, AF-Consult Switzerland AG, Baden (Switzerland); Frank, E. [Sektion Geologie (GEOL), Eidgenössisches Nuklear-Sicherheitsinspektorat (ENSI), Brugg (Switzerland)

    2017-04-15

    The paper represents a summary about our research projects conducted between 2003 and 2015 related to the mechanical behaviour of Opalinus Clay at Mont Terri. The research summarized covers a series of laboratory and field tests that address the brittle failure behaviour of Opalinus Clay, its undrained and effective strength, the dependency of petro-physical and mechanical properties on total suction, hydro-mechanically coupled phenomena and the development of a damage zone around excavations. On the laboratory scale, even simple laboratory tests are difficult to interpret and uncertainties remain regarding the representativeness of the results. We show that suction may develop rapidly after core extraction and substantially modifies the strength, stiffness, and petro-physical properties of Opalinus Clay. Consolidated undrained tests performed on fully saturated specimens revealed a relatively small true cohesion and confirmed the strong hydro-mechanically coupled behaviour of this material. Strong hydro-mechanically coupled processes may explain the stability of cores and tunnel excavations in the short term. Pore-pressure effects may cause effective stress states that favour stability in the short term but may cause longer-term deformations and damage as the pore-pressure dissipates. In-situ observations show that macroscopic fracturing is strongly influenced by bedding planes and faults planes. In tunnel sections where opening or shearing along bedding planes or faults planes is kinematically free, the induced fracture type is strongly dependent on the fault plane frequency and orientation. A transition from extensional macroscopic failure to shearing can be observed with increasing fault plane frequency. In zones around the excavation where bedding plane shearing/shearing along tectonic fault planes is kinematically restrained, primary extensional type fractures develop. In addition, heterogeneities such as single tectonic fault planes or fault zones

  2. The influence of the photoperiod on productive performance and survival of piabanha-of-Pardo (Brycon vonoi , hatchery

    Directory of Open Access Journals (Sweden)

    Marcelo Mattos Pedreira

    2018-02-01

    Full Text Available ABSTRACT: This research aimed to verify the influence of the photoperiod on the performance and survival piabanha-of-Pardo (Brycon vonoi larvae. Piabanha-of-Pardo larvae 24 hours post-hatch, with body weight of 2.44 ± 0.02mg, and total length of 7.82 ± 0.46mm, were subjected to five different photoperiods: 0L:24D, 6L:18D, 12L:12D, 18L:6D and 24L:0D (871.12 ± 92.65 lux. Daily, the water temperature, dissolved oxygen (DO, percentage of oxygen saturation, pH, and water conductivity were monitored, and presented similar water quality values among tanks with distinct photoperiods, and within the range considered appropriate for the genus Brycon larvae. Piabanha-of-Pardo larvae have better productive performance and survival rate at longer photoperiods, over 6 hours of light and below 12 hours of light per day. The 9L:15D photoperiod, specified by the derived equation, is indicated for the piabanha larviculture, but researches with the species and the photoperiod need to be better studied.

  3. Coupled Transport Phenomena in the Opalinus Clay: Implications for Radionuclide Transport

    International Nuclear Information System (INIS)

    Soler, J.M.

    1999-09-01

    Coupled phenomena (thermal and chemical osmosis, hyperfiltration, coupled diffusion, thermal diffusion, thermal filtration, Dufour effect) may play an important role in fluid, solute and heat transport in clay-rich formations, such as the Opalinus Clay (OPA), which are being considered as potential hosts for radioactive waste repositories. In this study, the potential effects of coupled phenomena on radionuclide transport in the vicinity of a repository for vitrified high-level radioactive waste (HLW) and spent nuclear fuel (SF) hosted by the Opalinus Clay, at times equal to or greater than the expected lifetime of the waste canisters (about 1000 years), have been addressed. Firstly, estimates of the solute fluxes associated with chemical osmosis, hyperfiltration, thermal diffusion and thermal osmosis have been calculated. Available experimental data concerning coupled transport phenomena in compacted clays, and the hydrogeological and geochemical conditions to which the Opalinus Clay is subject, have been used for these estimates. These estimates suggest that thermal osmosis is the only coupled transport mechanism that could have a strong impact on solute and fluid transport in the vicinity of the repository. Secondly, estimates of the heat fluxes associated with thermal filtration and the Dufour effect in the vicinity of the repository have been calculated. The calculated heat fluxes are absolutely negligible compared to the heat flux caused by thermal conduction. As a further step to obtain additional insight into the effects of coupled phenomena on solute transport, the solute fluxes associated with advection, chemical diffusion, thermal and chemical osmosis, hyperfiltration and thermal diffusion have been incorporated into a simple one-dimensional transport equation. The analytical solution of this equation, with appropriate parameters, shows again that thermal osmosis is the only coupled transport mechanism that could have a strong effect on repository

  4. Coupled Transport Phenomena in the Opalinus Clay: Implications for Radionuclide Transport

    Energy Technology Data Exchange (ETDEWEB)

    Soler, J.M.

    1999-09-01

    Coupled phenomena (thermal and chemical osmosis, hyperfiltration, coupled diffusion, thermal diffusion, thermal filtration, Dufour effect) may play an important role in fluid, solute and heat transport in clay-rich formations, such as the Opalinus Clay (OPA), which are being considered as potential hosts for radioactive waste repositories. In this study, the potential effects of coupled phenomena on radionuclide transport in the vicinity of a repository for vitrified high-level radioactive waste (HLW) and spent nuclear fuel (SF) hosted by the Opalinus Clay, at times equal to or greater than the expected lifetime of the waste canisters (about 1000 years), have been addressed. Firstly, estimates of the solute fluxes associated with chemical osmosis, hyperfiltration, thermal diffusion and thermal osmosis have been calculated. Available experimental data concerning coupled transport phenomena in compacted clays, and the hydrogeological and geochemical conditions to which the Opalinus Clay is subject, have been used for these estimates. These estimates suggest that thermal osmosis is the only coupled transport mechanism that could have a strong impact on solute and fluid transport in the vicinity of the repository. Secondly, estimates of the heat fluxes associated with thermal filtration and the Dufour effect in the vicinity of the repository have been calculated. The calculated heat fluxes are absolutely negligible compared to the heat flux caused by thermal conduction. As a further step to obtain additional insight into the effects of coupled phenomena on solute transport, the solute fluxes associated with advection, chemical diffusion, thermal and chemical osmosis, hyperfiltration and thermal diffusion have been incorporated into a simple one-dimensional transport equation. The analytical solution of this equation, with appropriate parameters, shows again that thermal osmosis is the only coupled transport mechanism that could have a strong effect on repository

  5. Population structure and connectivity of tiger sharks (Galeocerdo cuvier) across the Indo-Pacific Ocean basin.

    Science.gov (United States)

    Holmes, Bonnie J; Williams, Samuel M; Otway, Nicholas M; Nielsen, Einar E; Maher, Safia L; Bennett, Mike B; Ovenden, Jennifer R

    2017-07-01

    Population genetic structure using nine polymorphic nuclear microsatellite loci was assessed for the tiger shark ( Galeocerdo cuvier ) at seven locations across the Indo-Pacific, and one location in the southern Atlantic. Genetic analyses revealed considerable genetic structuring ( F ST  > 0.14, p  Indo-Pacific locations and Brazil. By contrast, no significant genetic differences were observed between locations from within the Pacific or Indian Oceans, identifying an apparent large, single Indo-Pacific population. A lack of differentiation between tiger sharks sampled in Hawaii and other Indo-Pacific locations identified herein is in contrast to an earlier global tiger shark nDNA study. The results of our power analysis provide evidence to suggest that the larger sample sizes used here negated any weak population subdivision observed previously. These results further highlight the need for cross-jurisdictional efforts to manage the sustainable exploitation of large migratory sharks like G. cuvier .

  6. Cadmium-induced disruption of environmental exploration and chemical communication in matrinxa, Brycon amazonicus

    International Nuclear Information System (INIS)

    Honda, R.T.; Fernandes-de-Castilho, M.; Val, A.L.

    2008-01-01

    The effects of cadmium exposure on both environment exploration and behavioral responses induced by alarm substance in matrinxa (Brycon amazonicus), a fish species endemic to the Amazon basin, were investigated. Fish exposed to 9.04 ± 0.07 μg/L waterborne cadmium for 96 h followed by 24 h depuration period in clean water, were video-recorded for 15 min, followed by immediate introduction of conspecific skin extract to the tank and a new 30 min period of fish video-recording. Cd-exposed matrinxa showed a significantly lowered locomotor activity (t-test t 12 = 2.7; p = 0.025) and spatial distribution (t-test t 12 = 2.4; p = 0.03) relative to the unexposed control fish prior to the alarm substance introduction, and did not present any significant reaction when the skin extract was introduced. The control fish, in opposite, showed a higher level of activity and spatial distribution prior the skin extract contact and significantly decreased their response after the chemical stimulus (locomotion-repeated-measure ANOVA F 1,11 = 5.6; p = 0.04; spatial distribution F 1,11 = 19.4; p = 0.001). In conclusion, exposure to a low level of cadmium affects both the environment exploration performance and the conspecific chemical communication in matrinxa. If the reduced environmental exploration performance of Cd-exposed fish is an adjustment to the compromised chemical communication or an independent effect of cadmium is the next step to be investigated

  7. Cadmium-induced disruption of environmental exploration and chemical communication in matrinxa, Brycon amazonicus

    Energy Technology Data Exchange (ETDEWEB)

    Honda, R.T. [Centro Universitario Nilton Lins - CUNL, Laboratory of Toxicology, Av. Prof. Nilton Lins 3259, Parque das Laranjeiras, Zip 69058-040 Manaus, AM (Brazil)], E-mail: rhonda@niltonlins.br; Fernandes-de-Castilho, M. [Universidade Federal do Parana - UFPR, Research Center on Animal Welfare (RECAW), Laboratory of Studies on Animal Stress, Department of Physiology, Sector of Biological Science, Jardim das Americas, Zip 81531-970 Curitiba, PR (Brazil); Val, A.L. [Instituto Nacional de Pesquisas da Amazonia - INPA, Laboratory of Ecophysiology and Molecular Evolution, Av. Andre Araujo 2936, Aleixo, Zip 69083-000 Manaus, AM (Brazil)

    2008-09-17

    The effects of cadmium exposure on both environment exploration and behavioral responses induced by alarm substance in matrinxa (Brycon amazonicus), a fish species endemic to the Amazon basin, were investigated. Fish exposed to 9.04 {+-} 0.07 {mu}g/L waterborne cadmium for 96 h followed by 24 h depuration period in clean water, were video-recorded for 15 min, followed by immediate introduction of conspecific skin extract to the tank and a new 30 min period of fish video-recording. Cd-exposed matrinxa showed a significantly lowered locomotor activity (t-test t{sub 12} = 2.7; p = 0.025) and spatial distribution (t-test t{sub 12} = 2.4; p = 0.03) relative to the unexposed control fish prior to the alarm substance introduction, and did not present any significant reaction when the skin extract was introduced. The control fish, in opposite, showed a higher level of activity and spatial distribution prior the skin extract contact and significantly decreased their response after the chemical stimulus (locomotion-repeated-measure ANOVA F{sub 1,11} = 5.6; p = 0.04; spatial distribution F{sub 1,11} = 19.4; p = 0.001). In conclusion, exposure to a low level of cadmium affects both the environment exploration performance and the conspecific chemical communication in matrinxa. If the reduced environmental exploration performance of Cd-exposed fish is an adjustment to the compromised chemical communication or an independent effect of cadmium is the next step to be investigated.

  8. Necrophagy of a nurse shark (Ginglymostoma cirratum) by tiger sharks (Galeocerdo cuvier)

    OpenAIRE

    Rada, Danilo P; Programa de Pós Graduação em Ciências Biológicas, CCEN, Universidade Federal da Paraíba, João Pessoa, Paraíba, Brazil; Burgess, George H; Florida Museum of Natural History University of Florida, Gainesville, Florida, U.S.A.; Rosa, Ricardo S; Departamento de Sistemática e Ecologia, CCEN, Universidade Federal da Paraíba, João Pessoa, Paraíba, Brazil.; Gadig, Otto F; Laboratório de Pesquisa em Elasmobrânquios e Nécton Marinho, UNESP, São Vicente, São Paulo, Brazil.

    2015-01-01

    The aim of this study is to report a scavenging event, involving the consumption of a nurse shark, Ginglymostoma cirratum, by tiger sharks, Galeocerdo cuvier, at Fernando de Noronha archipelago, Brazil. Recreational divers found and photographed a bitten nurse shark carcass, just after sighting two tiger sharks near of the site. We estimated the sharks total lengths and discussed aspects of this feeding interaction using of images of forensic analysis. A straight cut on the nurse shark caudal...

  9. Population Parameters of Blainville’s and Cuvier’s Beaked Whales

    Science.gov (United States)

    2014-09-30

    waters, they are usually difficult to study. El Hierro (Canary Islands) holds resident populations of Blainville’s and Cuvier’s beaked whales in...surveys off El Hierro , according to plan. Four of these cruises took place since the last report in September 2013, summing 38 days of fieldwork performed...marks as to be individually recognizable. 3 Publication of results of the ONR funded cetacean research in El Hierro in 2014 Peer reviewed

  10. Fifteen years of microbiological investigation in Opalinus Clay at the Mont Terri rock laboratory (Switzerland)

    Energy Technology Data Exchange (ETDEWEB)

    Leupin, O.X. [National Cooperative for the Disposal of Radioactive Waste (NAGRA), Wettingen (Switzerland); Bernier-Latmani, R.; Bagnoud, A. [Swiss Federal Office of Technology EPFL, Lausanne (Switzerland); Moors, H.; Leys, N.; Wouters, K. [Belgian Nuclear Research Centre SCK-CEN, Mol (Belgium); Stroes-Gascoyne, S. [University of Saskatchewan, Saskatoon (Canada)

    2017-04-15

    Microbiological studies related to the geological disposal of radioactive waste have been conducted at the Mont Terri rock laboratory in Opalinus Clay, a potential host rock for a deep geologic repository, since 2002. The metabolic potential of microorganisms and their response to excavation-induced effects have been investigated in undisturbed and disturbed claystone cores and in pore- (borehole) water. Results from nearly 15 years of research at the Mont Terri rock laboratory have shown that microorganisms can potentially affect the environment of a repository by influencing redox conditions, metal corrosion and gas production and consumption under favourable conditions. However, the activity of microorganisms in undisturbed Opalinus Clay is limited by the very low porosity, the low water activity, and the largely recalcitrant nature of organic matter in the claystone formation. The presence of microorganisms in numerous experiments at the Mont Terri rock laboratory has suggested that excavation activities and perturbation of the host rock combined with additional contamination during the installation of experiments in boreholes create favourable conditions for microbial activity by providing increased space, water and substrates. Thus effects resulting from microbial activity might be expected in the proximity of a geological repository i.e., in the excavation damaged zone, the engineered barriers, and first containments (the containers). (authors)

  11. Fifteen years of microbiological investigation in Opalinus Clay at the Mont Terri rock laboratory (Switzerland)

    International Nuclear Information System (INIS)

    Leupin, O.X.; Bernier-Latmani, R.; Bagnoud, A.; Moors, H.; Leys, N.; Wouters, K.; Stroes-Gascoyne, S.

    2017-01-01

    Microbiological studies related to the geological disposal of radioactive waste have been conducted at the Mont Terri rock laboratory in Opalinus Clay, a potential host rock for a deep geologic repository, since 2002. The metabolic potential of microorganisms and their response to excavation-induced effects have been investigated in undisturbed and disturbed claystone cores and in pore- (borehole) water. Results from nearly 15 years of research at the Mont Terri rock laboratory have shown that microorganisms can potentially affect the environment of a repository by influencing redox conditions, metal corrosion and gas production and consumption under favourable conditions. However, the activity of microorganisms in undisturbed Opalinus Clay is limited by the very low porosity, the low water activity, and the largely recalcitrant nature of organic matter in the claystone formation. The presence of microorganisms in numerous experiments at the Mont Terri rock laboratory has suggested that excavation activities and perturbation of the host rock combined with additional contamination during the installation of experiments in boreholes create favourable conditions for microbial activity by providing increased space, water and substrates. Thus effects resulting from microbial activity might be expected in the proximity of a geological repository i.e., in the excavation damaged zone, the engineered barriers, and first containments (the containers). (authors)

  12. Hydro-mechanical aspects: glacial loading/erosion - the opalinus clay study

    International Nuclear Information System (INIS)

    Marschall, P.; Kupfer, T.; Kuhlmann, U.

    2004-01-01

    In Nagra's high level waste programme the future geological evolution of the investigation area in the Zurcher Weinland (NE Switzerland) is considered over a time period of around 1 Ma. Uplift, erosion and climatic changes were identified as processes that may affect the long-term performance of a repository for spent fuel (SF), vitrified high-level waste (HLW) and long-lived intermediate-level waste (ILW). The possible impact of those long-term processes on the barrier function of the host rock formation (Opalinus Clay) comprises: (i) the change of the vertical hydraulic gradient caused by changing recharge/discharge conditions in the regional aquifer systems; (ii) permeability enhancement of the host rock formation due to the uplift process; and (iii) expulsion of contaminated pore water from the disposal area as a result of repeated glacial loading. Due to the fact that the discharge level of the regional aquifer systems is defined by the Rhine valley and the regional recharge areas are characterised by moderate elevations (typically 2 are not expected within the next several million years. Hence, the topography of NE Switzerland together with the favourable hydraulic properties of the host rock formation prevent efficiently the vertical exchange of groundwater between the regional aquifer systems. Even on geological time scales of millions of years the expected vertical pore water flow through the host rock formation is in the order of 10 -14 m/s and lower. At present, the Opalinus Clay forms a perfect hydraulic barrier. The process of ongoing uplift, however, may give rise to embrittlement of the rock, entailed by permeability enhancement. Evidence for permeability enhancement of Opalinus Clay in shallow depth was observed by Hekel (1994). On the other hand, regional studies confirmed the low permeability of the Opalinus Clay formation in greater depth even when fractured (Gautschi, 2001; Marschall et al., 2003). Such evidence, together with conceptual

  13. Time-dependent Flow and Transport Calculations for Project Opalinus Clay (Entsorgungsnachweis)

    International Nuclear Information System (INIS)

    Kosakowski, G.

    2004-07-01

    This report describes two specific assessment cases used in the safety assessment for a proposed deep geological repository for spent fuel, high level waste and long-lived intermediate-level waste, sited in the Opalinus Clay of the Zuercher Weinland in northern Switzerland (Project Entsorgungsnachweis, NAG RA, 2002d). In this study the influence of time dependent flow processes on the radionuclide transport in the geosphere is investigated. In the Opalinus Clay diffusion dominates the transport of radionuclides, but processes exist that can locally increase the importance of the advective transport for some time. Two important cases were investigated: (1) glaciation-induced flow due to an additional overburden in the form of an ice shield of up to 400 m thickness and (2) fluid flow driven by tunnel convergence. For the calculations the code FRAC3DVS (Therrien and Sudicky, 1996) was used. FRAC3DVS solves the three-dimensional flow and transport equation in porous and fractured media. For the case of glaciation-induced flow (1) a two-dimensional reference model without glaciations was calculated. During the glaciations the geosphere release-rates are up to a factor of about 1.7 higher compared to the reference model. The influence of glaciations on the transport of cations or neutral species is less than for anions, since the importance of the advective transport for anions is higher due to the lower accessible porosity for anions. The increase in the release rates during glaciations is lower for sorbing compared to non-sorbing radionuclides. The influence of the tunnel convergence (2) on the transport of radionuclides in the geosphere is very small. Due to the higher source term the geosphere release rates are slightly higher if tunnel convergence is considered. In addition to the two assessment cases this report investigates the applicability of the one-dimensional approximation for modelling transport through the Opalinus Clay. For the reference case of the safety

  14. Dinâmica populacional da matrinxã Brycon amazonicus (Characidae na Amazônia Central Population dynamics of matrinxã Brycon amazonicus (Characidae in Central Amazon

    Directory of Open Access Journals (Sweden)

    Leocy C. dos Santos Filho

    2009-06-01

    Full Text Available The matrinxã, Brycon amazonicus (Spix & Agassiz, 1829 is one of the most important fishery resources of the Amazonas state. Its population dynamics in Central Amazon was analyzed based on total landing and biometry data registered in the main landing port of Manaus, between 1994 and 2002. Growth and mortality rates were estimated separately for the rivers Purus, Madeira and Solimões. Differences in size structure and growth curves suggest that different population units exist among these rivers, requiring individualized evaluation and fisheries management strategies. The analysis of the yield per recruit does not indicate overexploitation. However, the highest relative exploitation rate was observed in the Madeira river. The suggested management strategies are related to restrictions to the fishery in the main fishing grounds during the migratory dispersal period, instead of restrictions during reproductive periods.

  15. Population genetic structure revealed by a school of the freshwatermigratory fish, Brycon hilarii Estructura genética poblacional revelada por un cardumen del pez migratorio de agua dulce, Brycon hilarii

    Directory of Open Access Journals (Sweden)

    Alexandra Sanches

    2012-07-01

    Full Text Available It is believed that different genetic populations of migratory fishes can co-exist in a single hydrographic system. Although different populations may occupy and explore the river together, they segregate during the spawning season and consequently the population genetic structuring is maintained. Genetic variation of a Brycon hilarii spawning school and samples from different collection sites in the Miranda River basin were surveyed using seven microsatellites. Population structuring was revealed by a significant differentiation of the spawning school related to the supposed local populations. The genetic differentiation detected may be supported by behavior during the reproductive season that promotes the maintenance of the genetic integrity of different populations. These data may contribute toward the understanding of the behavior and biology of these fish as well as fishery management and species conservation programs.Se ha documentado que diferentes poblaciones genéticas de peces migratorios pueden coexistir en un único sistema hidrográfico. Diferentes poblaciones pueden ocupar y explorar el río juntas, pero se segregan durante la temporada de desove y consecuentemente la estructuración genética poblacional se mantiene. La diversidad genética de un cardumen reproductivo de Brycon hilarii y muestras de diferentes sitios en la cuenca del Río Miranda fueron analizadas mediante siete microsatélites. La estructura poblacional fue revelada por una diferenciación genética significativa del cardumen reproductivo con las muestras de las poblaciones locales. La diferenciación genética detectada puede ser resultado de un probable comportamiento durante la temporada reproductiva, que promueve el mantenimiento de la integridad genética de las diferentes poblaciones. Estos datos pueden contribuir a la comprensión del comportamiento y biología de estos peces, así como amparar programas de gestión de la pesca y conservación de las

  16. CARACTERIZACIÓN GENÉTICA DE LOTES DE Brycon orbignyanus UTILIZADOS EN PROGRAMAS DE REPOBLAMIENTO

    Directory of Open Access Journals (Sweden)

    Nelson Lopera B

    2008-04-01

    Full Text Available Objetivo. Caracterizar genéticamente dos lotes y una progenie de Brycon orbignyanus destinados para programas de repoblamiento, utilizando la técnica molecular de RAPD (Random amplified polymorphic DNA. Materiales y métodos. Se analizaron 58 reproductores originarios de dos piscícolas ubicadas en las ciudades de Castillo (A:30 individuos y Porto Ferreira (C:28 individuos, mantenidos en cautiverio hace seis años en la estación de acuicultura e hidrología de la Duke Energy Internacional (Geração Paranapanema (São Paulo-Brasil. Treinta larvas de la progenie del lote A (B también se analizaron. Resultados. Los 14 primers usados produjeron 87 fragmentos de los cuales 70.11% fueron polimórficos. Fueron observadas diferencias (p£0.05 en la frecuencia de 31 fragmentos, con tres exclusivos para el lote A. Los valores de divergencia, distancia e identidad genética mostraron que la diversidad genética del lote A fue mantenida en la progenie y que existe una baja diferenciación entre los lotes de reproductores. El análisis de variancia molecular mostró que la mayor parte de la variación está dentro de cada lote (87.45% y no entre ellos (12.55%. Este resultado se corroboró con los valores de FST (0.125 y con el dendrograma, que indicaron una moderada diferenciación genética, sin la formación de agrupamientos. Conclusiones. La diversidad genética fue preservada en la progenie debido al manejo eficiente de la reproducción. No hubo una diferenciación genética entre los lotes de reproductores, debido posiblemente a que el origen natural de ambos fue el río Paraná.

  17. Effect of methyl parathion on the muscle and brain acetylcholinesterase activity of matrinxã (Brycon cephalus

    Directory of Open Access Journals (Sweden)

    Almeida Luciana Cristina de

    2005-01-01

    Full Text Available Farming of the freshwater fish is emerging in Brazil and many species from the wild are promising. The teleost matrinxã (Brycon cephalus holds several characteristics such as fast growth rate, high commercial value and adaptability to artificial raring conditions, which make it a promising species for commerce. The use of pesticides in aquatic environment is frequent in Brazil, and methyl parathion is very common in aquaculture. We have determined the enzymatic activity of acetyl cholinesterase in white muscle and brain of matrinxã exposed to 2ppm of environmental methyl parathion for 24 hours. There was 64% and 69% of acetyl cholinesterase inhibition in muscle and brain respectively. These activities were not recovered after 8 days from exposure to this pesticide. It can be concluded that acetyl cholinesterase from those tissues was inhibited by small amounts of methyl parathion, and the main effect was observed in the brain.

  18. Ventilation test at Mont Terri. Geoelectric monitoring of the opalinus clay desaturation. Phase 2

    International Nuclear Information System (INIS)

    Wieczorek, Klaus; Zhang, Chun-Liang; Rothfuchs, Tilmann

    2008-04-01

    Between December 2001 and May 2004, a ventilation experiment (VE) was performed in the Mont Terri Underground Research Laboratory (URL) and co-financed by the Commission of the European Communities. The objective was to investigate the desaturation of consolidated clay formations in consequence of the ventilation of underground openings of a repository in such a formation. The results of the geoelectric measurements performed in the second phase of the Mont Terri ventilation test can be summarized as follows: Geoelectric tomography has been found suitable for monitoring ventilation-induced saturation changes in the Opalinus clay. During ventilation with dry air a desaturation down to below 50% could be detected in both desaturation cycles. The desaturated zone extends less than 0.5 m into the rock around the microtunnel. During the second resaturation phase, ventilation with humid air led to quick resaturation at the tunnel surface, while resaturation of the rock mass took months. The still ongoing third resaturation phase seems to imply that resaturation of the rock mass may take years with no air circulation in the tunnel. The laboratory investigations on the Opalinus clay included the determination of water retention capacity, swelling pressure, free swelling/shrinking strains induced by moisture changes, and response of normal and large hollow clay samples to the ventilation of the central boreholes at different air humidity values. The Opalinus clay has a high water absorption capacity. The amount of water uptake in unconstraint conditions is much higher than the water content in the naturally confined state, indicating that the pore water in the natural clay rock is predominantly bound on clay minerals. The swelling pressure induced by wetting with vapour is very close to the major lithostatic stress at the sampling location. Water uptake from vapour causes a large free expansion of up to 12% over 8 months and even a breakdown along bedding planes. Release of

  19. Investigations for the influence of geochemical parameters on the sorption and desorption of lanthanides and uranium onto opalinus clay as potential host rock for a repository

    International Nuclear Information System (INIS)

    Moeser, Christina

    2010-01-01

    The development of a disposal in deep geological formations for radioactive waste is a very important task for the future. The safety assessment for more than a hundred thousand years needs a full understanding of all processes of interaction between the radioactive waste and the surrounded formations. This work contributes to this understanding. The interaction between lanthanides (homologues of the actinides americium, curium and berkelium) / uranium and the host rock opalinus clay under influence of organic substances (NOM) have been analyzed and discussed. The complex system was split into 3 binary basic systems with the following interactions - Interactions between lanthanides / uranium and NOM - Interactions between lanthanides / uranium and the opalinus clay - Interactions between NOM and opalinus clay All binary systems can be influenced by geological parameters like pH, ion strength and competing cations. The sorption / desorption of the lanthanides onto the opalinus clay is analyzed via inductively coupled plasma mass spectrometry. For the investigation of the complexation behavior of metals with NOM we used capillary electrophoresis coupled with inductively coupled plasma mass spectrometry. Under these conditions the chosen model organic humic acid affected the sorption of the lanthanides onto opalinus clay favorably. The smaller organic compounds, which dominate in the composition of the clay organics, remobilized the metals after sorption onto clay and the sorption can be inhibited by NOM. Due to the reduced metal sorption onto Opalinus clay by NOM, a migration through the clay may be possible.

  20. Three-dimensional FDEM numerical simulation of failure processes observed in Opalinus Clay laboratory samples

    Directory of Open Access Journals (Sweden)

    Omid Mahabadi

    2014-12-01

    Full Text Available This study presents the first step of a research project that aims at using a three-dimensional (3D hybrid finite-discrete element method (FDEM to investigate the development of an excavation damaged zone (EDZ around tunnels in a clay shale formation known as Opalinus Clay. The 3D FDEM was first calibrated against standard laboratory experiments, including Brazilian disc test and uniaxial compression test. The effect of increasing confining pressure on the mechanical response and fracture propagation of the rock was quantified under triaxial compression tests. Polyaxial (or true triaxial simulations highlighted the effect of the intermediate principal stress (σ2 on fracture directions in the model: as the intermediate principal stress increased, fractures tended to align in the direction parallel to the plane defined by the major and intermediate principal stresses. The peak strength was also shown to vary with changing σ2.

  1. The safety case for a HLW repository in Opalinus clay: aims, methodology, first results

    International Nuclear Information System (INIS)

    Zuidema, Piet

    2002-01-01

    Piet Zuidema (Nagra, Switzerland) described the development of the safety case for a high level waste repository in Opalinus clay in which canisters would be placed in large vaults. The current phase of work was concerned with demonstrating the feasibility of the disposal concept. The Safety Case is taken to mean a set of arguments to support a statement that the proposed facility will meet relevant safety criteria and will include arguments giving the basis for confidence that those arguments are correct and properly taking account of uncertainties. The safety strategy was concerned both with the inherent robustness of the disposal concept and the adequacy of the assessment capability. As regards the former, the arguments being advanced were primarily qualitative. Key issues in terms of the documentation of the Safety Case were traceability and transparency of information, including how to ensure that key arguments did not become obscured because of the need to make available very large quantities of information

  2. Performance of the Opalinus Clay under thermal loading: experimental results from Mont Terri rock laboratory (Switzerland)

    Energy Technology Data Exchange (ETDEWEB)

    Gens, A. [Universitat Politència de Catalunya, Barcelona (Spain); Wieczorek, K. [Gesellschaft für Anlagen- und Reaktorsicherheit (GRS) GmbH, Braunschweig (Germany); Gaus, I. [National Cooperative for the Disposal of Radioactive Waste (NAGRA), Wettingen (Switzerland); and others

    2017-04-15

    The paper presents an overview of the behaviour of Opalinus Clay under thermal loading as observed in three in situ heating tests performed in the Mont Terri rock laboratory: HE-B, HE-D and HE-E. The three tests are summarily described; they encompass a broad range of test layouts and experimental conditions. Afterwards, the following topics are examined: determination of thermal conductivity, thermally-induced pore pressure generation and thermally-induced mechanical effects. The mechanisms underlying pore pressure generation and dissipation are discussed in detail and the relationship between rock damage and thermal loading is examined using an additional in situ test: SE-H. The paper concludes with an evaluation of the various thermo-hydro-mechanical (THM) interactions identified in the heating tests. (authors)

  3. The opalinus clay project - disposal of medium and highly-active nuclear wastes

    International Nuclear Information System (INIS)

    Mueller, U.

    2003-01-01

    This article describes the project to demonstrate the feasibility of disposing of long-living medium-active and highly-radioactive nuclear wastes in sedimentary rock in Switzerland. The disposal tasks to be carried out are reviewed and the solutions proposed are described, including short-term handling, intermediate storage and final disposal of low, medium and highly-active wastes. The present state of affairs is described and, in particular, the feasibility of implementing a final storage facility in the opalinus clay beds to be found in northern Switzerland. The project for such a facility in the wine-growing area of the canton of Zurich is described in detail, including the storage concept, the technology to be used and operational aspects as well as questions of safety

  4. Population dynamics of the yellowstripe scad (Selaroides leptolepis Cuvier, 1833) and Indian mackerel (Rastrelliger kanagurta Cuvier, 1816) in the Wondama Bay Water, Indonesia

    Science.gov (United States)

    Sala, R.; Bawole, R.; Runtuboi, F.; Mudjirahayu; Wopi, I. A.; Budisetiawan, J.; Irwanto

    2018-03-01

    The Wondama Bay water is located within the Cendrawasih Bay National Park and is potential for fishery resources, including pelagic fish such as yellowstripe scad (Selaroides leptolepis Cuvier, 1833) and Indian mackerel (Rastrelliger kanagurta Cuvier, 1816). Yet, information about the population dynamics of these species in the region is unknown until today. Meanwhile, the fishing activities have been quite intensive and include the dominant catches over the last ten years by traditional fishermen fishing using liftnets. Therefore, this study aims to determine some of specific characteristics of the population dynamics and fish utilization status of scad and mackerel in the waters of the Wondama Bay. Data used in this study were taken from direct observation of catch of liftnet fishery. The data then were analysed by using FISAT II to estimate the growth parameters, mortality rates, and yield per recruitment. The results showed that yellowstripe scad has the positive allometric growth, while Indian mackerel followed isometric growth. Models of fish growth were L(t) = 22 (1-e-3.0(t-0.05)) for yellowstripe scad and L(t) = 27.8 (1-e-4.0(t-0.04)) for Indian mackerel. The natural mortality (M) of 4.19 year-1, fishing mortality (F) of 5.01 year-1, and total mortality (Z) of 9.20 year-1 were for yellowstripe scad, and M of 4.74 year-1, F of 2.52 year-1 and Z of 7.26 year-1 were for Indian mackerel. Based on the mortality rates, estimated exploitation rate for the yellowatripe scad was 54 % and the Indian mackerel was 35 %. To increase the production of catch without increasing fishing effort (fishing mortality) can be done by increasing the size of fish caught or the Lc/L∞ should be greater than 0.5.

  5. Extracting DNA from 'jaws': High yield and quality from archived tiger shark (Galeocerdo cuvier) skeletal material

    DEFF Research Database (Denmark)

    Eg Nielsen, Einar; Morgan, J. A T; Maher, S. L.

    2017-01-01

    of tiger sharks (Galeocerdo cuvier). Protocols were compared for DNA yield and quality using a qPCR approach. For jaw swarf, all methods provided relatively high DNA yield and quality, while large differences in yield between protocols were observed for vertebrae. Similar results were obtained from samples...... observed, likely reflecting different preparation and storage methods for the trophies. Trial sequencing of DNA capture genomic libraries using 20 000 baits revealed that a significant proportion of captured sequences were derived from tiger sharks. This study demonstrates that archived shark jaws...

  6. Hystological analysis of ovarian development of the characiform Oligosarcus hepsetus (Cuvier, 1829 in a Brazilizn Reservoir

    Directory of Open Access Journals (Sweden)

    R. N Santos

    Full Text Available A histological analysis was performed of the ovarian development of Oligosarcus hepsetus (Cuvier, 1829, a medium-sized carnivorous Characiform species in the Lajes reservoir, Brazil. A total of 125 fishes, collected monthly between April 2001 and June 2002 were examined by routine macroscopic and histological techniques. Eight phases of the oocyte development were described, and 4 stages and 4 sub-stages of gonadal development were proposed. Spawning in reservoirs, similarly to that in rivers, is in batches, which favors juvenile survival and suggests that the impoundment of this area did not influence the reproductive strategy of this very successful species in a dammed environment.

  7. Geochemical signature of paleofluids in microstructures from Main Fault in the Opalinus Clay of the Mont Terri rock laboratory, Switzerland

    Energy Technology Data Exchange (ETDEWEB)

    Clauer, N. [Laboratoire d’Hydrologie et de Géochimie de Strasbourg (CNRS-UdS), Strasbourg (France); Techer, I. [Equipe Associée, Chrome, Université de Nîmes, Nîmes (France); Nussbaum, Ch. [Swiss Geological Survey, Federal Office of Topography Swisstopo, Wabern (Switzerland); Laurich, B. [Structural Geology, Tectonics and Geomechanics, RWTH Aachen University, Aachen (Germany); Laurich, B. [Federal Institute for Geosciences and Natural Resources BGR, Hannover (Germany)

    2017-04-15

    The present study reports on elemental and Sr isotopic analyses of calcite and associated celestite infillings of various microtectonic features collected mostly in the Main Fault of the Opalinus Clay from Mont Terri rock laboratory. Based on a detailed microstructural description of veins, slickensides, scaly clay aggregates and gouges, the geochemical signatures of the infillings were compared to those of the leachates from undeformed Opalinus Clay, and to the calcite from veins crosscutting Hauptrogenstein, Passwang and Staffelegg Formations above and below the Opalinus Clay. Vein calcite and celestite from Main Fault yield identical {sup 87}Sr/{sup 86}Sr ratios that are also close to those recorded in the Opalinus Clay matrix inside the Main Fault, but different from those of the diffuse Opalinus Clay calcite outside the fault. These varied {sup 87}Sr/{sup 86}Sr ratios of the diffuse calcite evidence a lack of interaction among the associated connate waters and the flowing fluids characterized by a homogeneous Sr signature. The {sup 87}Sr/{sup 86}Sr homogeneity at 0.70774 ± 0.00001 (2σ) for the infillings of most microstructures in the Main Fault, as well as of veins from nearby limestone layer and sediments around the Opalinus Clay, claims for an 'infinite' homogeneous marine supply, whereas the gouge infillings apparently interacted with a fluid chemically more complex. According to the known regional paleogeographic evolution, two seawater supplies were inferred and documented in the Delémont Basin: either during the Priabonian (38-34 Ma ago) from western Bresse graben, and/or during the Rupelian (34-28 Ma ago) from northern Rhine Graben. The Rupelian seawater that yields a mean {sup 87}Sr/{sup 86}Sr signature significantly higher than those of the microstructural infillings seems not to be the appropriate source. Alternatively, Priabonian seawater yields a mean {sup 87}Sr/{sup 86}Sr ratio precisely matching that of the leachates from diffuse

  8. Clay shale as host rock. A geomechanical contribution about Opalinus clay; Tonstein als Wirtsgestein. Ein geomechanischer Beitrag ueber Opalinuston

    Energy Technology Data Exchange (ETDEWEB)

    Lempp, Christof; Menezes, Flora; Sachwitz, Simon [Halle-Wittenberg Univ., Halle (Saale) (Germany). Inst. fuer Geowissenschaften und Geographie

    2016-12-15

    The Opalinuston is a prominent rock representing the type of organic clay shales or clay stones within the sequence of Triassic and Jurassic marine sediments in Southern Germany. The rock forms a homogenous unit some ten meters thick. The degree of consolidation of this type of pelitic rock depends mainly on the former load conditions, but is also dependent on the long-term weathering and even on the present exposition. The geomechanical parameters such as shear strength, tensional strength and permeability vary with the state of consolidation and become important when the use is discussed of such rocks for radioactive waste disposal. A tunneling project at the northern escarpment of the Swabian Alb (Southwest Germany) within the Opalinus clay offered the rare opportunity to obtain fresh unweathered rock samples in greater amounts compared to fresh drilling cores from which geomechanical investigations are usually undertaken. Consequently, the results of geomechanical laboratory testings are presented in order to compare here the results of multistep triaxial compression tests, of hydraulic fracturing laboratory tests and of some other tests for rock characterization with the corresponding results of Opalinus clay sites in Switzerland that were investigated by the Swiss Nagra Company for host rock characterization. After a discussion of the relevant state of fresh Opalinus clay, especially of suction pressure conditions and saturation state, the results of triaxial shear tests are presented. Increasing shear deformation at increasing pressure and unchanged water saturation do not result in a significant strength reduction of the Opalinus clay. The rock shows increasing cohesion and stiffness, if multiple loading has repeatedly reached the failure point. Thus there is no increased permeability with continued shearing. Only at the beginning of the shearing process is a temporarily increased permeability to be expected due to dilatation processes. An increased

  9. Litho- and biostratigraphy of the Opalinus Clay and bounding formations in the Mont Terri rock laboratory (Switzerland)

    International Nuclear Information System (INIS)

    Hostettler, B.; Reisdorf, A. G.; Jaeggi, D.

    2017-01-01

    A 250 m-deep inclined well, the Mont Terri BDB-1, was drilled through the Jurassic Opalinus Clay and its bounding formations at the Mont Terri rock laboratory (NW Switzerland). For the first time, a continuous section from (oldest to youngest) the topmost members of the Staffelegg Formation to the basal layers of the Hauptrogenstein Formation is now available in the Mont Terri area. We extensively studied the drill core for lithostratigraphy and biostratigraphy, drawing upon three sections from the Mont Terri area. The macropaleontological, micropaleontological, and palynostratigraphical data are complementary, not only spatially but they also cover almost all biozones from the Late Toarcian to the Early Bajocian. We ran a suite of geophysical logs to determine formational and intraformational boundaries based on clay content in the BDB-1 well. In the framework of an interdisciplinary study, analysis of the above-mentioned formations permitted us to process and derive new and substantial data for the Mont Terri area in a straightforward way. Some parts of the lithologic inventory, stratigraphic architecture, thickness variations, and biostratigraphic classification of the studied formations deviate considerably from occurrences in northern Switzerland that crop out further to the east. For instance, with the exception of the Sissach Member, no further lithostratigraphic subdivision in members is proposed for the Passwang Formation. Also noteworthy is that the ca. 130 m-thick Opalinus Clay in the BDB-1 core is 20 m thinner than that equivalent section found in the Mont Terri tunnel. The lowermost 38 m of the Opalinus Clay can be attributed chronostratigraphically solely to the Aalensis Zone (Late Toarcian). Deposition of the Opalinus Clay began at the same time farther east in northern Switzerland (Aalensis Subzone, Aalensis Zone), but in the Mont Terri area the sedimentation rate was two or three orders of magnitude higher. (authors)

  10. Litho- and biostratigraphy of the Opalinus Clay and bounding formations in the Mont Terri rock laboratory (Switzerland)

    Energy Technology Data Exchange (ETDEWEB)

    Hostettler, B. [Naturhistorisches Museum der Burgergemeinde Berne, Berne (Switzerland); Reisdorf, A. G. [Geologisch-Paläontologisches InstitutUniversität Basle, Basle (Switzerland); Jaeggi, D. [Swisstopo, Federal Office of Topography, Wabern (Switzerland); and others

    2017-04-15

    A 250 m-deep inclined well, the Mont Terri BDB-1, was drilled through the Jurassic Opalinus Clay and its bounding formations at the Mont Terri rock laboratory (NW Switzerland). For the first time, a continuous section from (oldest to youngest) the topmost members of the Staffelegg Formation to the basal layers of the Hauptrogenstein Formation is now available in the Mont Terri area. We extensively studied the drill core for lithostratigraphy and biostratigraphy, drawing upon three sections from the Mont Terri area. The macropaleontological, micropaleontological, and palynostratigraphical data are complementary, not only spatially but they also cover almost all biozones from the Late Toarcian to the Early Bajocian. We ran a suite of geophysical logs to determine formational and intraformational boundaries based on clay content in the BDB-1 well. In the framework of an interdisciplinary study, analysis of the above-mentioned formations permitted us to process and derive new and substantial data for the Mont Terri area in a straightforward way. Some parts of the lithologic inventory, stratigraphic architecture, thickness variations, and biostratigraphic classification of the studied formations deviate considerably from occurrences in northern Switzerland that crop out further to the east. For instance, with the exception of the Sissach Member, no further lithostratigraphic subdivision in members is proposed for the Passwang Formation. Also noteworthy is that the ca. 130 m-thick Opalinus Clay in the BDB-1 core is 20 m thinner than that equivalent section found in the Mont Terri tunnel. The lowermost 38 m of the Opalinus Clay can be attributed chronostratigraphically solely to the Aalensis Zone (Late Toarcian). Deposition of the Opalinus Clay began at the same time farther east in northern Switzerland (Aalensis Subzone, Aalensis Zone), but in the Mont Terri area the sedimentation rate was two or three orders of magnitude higher. (authors)

  11. Rendimento de carcaça de peixe matrinxã (Brycon cephalus nos diferentes cortes de cabeça Carcass yielding of Brycon cephalus in different head cuts

    Directory of Open Access Journals (Sweden)

    Juliana Sampaio Guedes Gomiero

    2003-02-01

    Full Text Available Com este experimento objetivou-se avaliar o rendimento de carcaça de matrinxã (Brycon cephalus nos diferentes cortes de cabeça, sendo o mesmo conduzido na Estação de Piscicultura da Universidade Federal de Lavras, no mês de maio de 2001. O delineamento foi inteiramente casualizado com 2 tratamentos (corte reto da cabeça e corte oblíquo da cabeça e 20 repetições. Os peixes foram retirados dos tanques com peso médio de 840 gramas e abatidos por choque térmico em água com gelo. Foram analisados o rendimento de filé, rendimento de tronco limpo e a relação entre o comprimento do filé e o comprimento padrão. Concluiu-se que o corte oblíquo da cabeça proporcionou melhores rendimentos de tronco limpo (65,67% em relação ao corte reto da cabeça (61,28%. Quanto à relação comprimento do filé e comprimento padrão, o corte oblíquo da cabeça também mostrou resultados superiores quando comparado ao corte reto da cabeçaThe objective of this study was to determine the carcass yielding of Brycon cephalus in different cuts of its head. The experiment was conducted in the Fish Farmer at the Federal University of Lavras, in may 2001. The experiment was in a randomized design with two treatments (head rightly cut and head obliquely cut and twenty replications. The fish were removed from the tank with an average weigh of 840 g and were killed by temperature shock with water and ice. It was concluded that the head obliquely cut rendered the best barrel clean yielding (66% compared to the head rightly cut (61%. In the same way, the ratio fillet/standard length also showed better results for the oblique cut compared to the right cut

  12. Investigation of two-phase flow phenomena associated with corrosion in an SF/HLW repository in Opalinus Clay, Switzerland

    International Nuclear Information System (INIS)

    Senger, R.; Marschall, P.; Finsterle, S.

    2008-01-01

    Gas generation from corrosion of the waste canisters and gas accumulation in the backfilled emplacement tunnels is a key issue in the assessment of long-term radiological safety of the proposed repository for spent fuel and high-level waste (SF/HLW) sited in the Opalinus Clay formation of Northern Switzerland. Previous modeling studies indicated a significant pressure buildup in the backfilled emplacement tunnels for those sensitivity runs, where corrosion rates were high and the permeability of the Opalinus Clay was very low. As an extension to those studies, a refined process model of the canister corrosion phenomena has been developed, which accounts not only for the gas generation but also for the water consumption associated with the chemical reaction of corrosion of steel under anaerobic conditions. The simulations with the new process model indicate, that with increasing corrosion rates and decreasing host-rock permeability, pressure buildup increased, as expected. However, the simulations taking into account water consumption show that the pressure buildup is reduced compared to the simulation considering only gas generation. The pressure reduction is enhanced for lower permeability of the Opalinus Clay and for higher corrosion rates, which correspond to higher gas generations rates and higher water consumption rates. Moreover, the simulated two-phase flow patterns in the engineered barrier system (EBS) and surrounding Opalinus Clay show important differences at late time of the gas production phase as the generated gas continues to migrate outward into the surrounding host rock. For the case without water consumption, the water flow indicates overall downward flow due to a change in the overall density of the gas-fluid mixture from that based on the initially prescribed hydrostatic pressure gradient. For the case with water consumption, water flow converges toward the waste canister at a rate corresponding to the water consumption rate associated with the

  13. Influence of carbonate micro-fabrics on the failure strength of Callovo-Oxfordian clay stones and Opalinus Clay

    International Nuclear Information System (INIS)

    Klinkenberg, M.; Dohrmann, R.; Kaufhold, S.; Siegesmund, S.

    2010-01-01

    Document available in extended abstract form only. The potential use of clay stones as host rock for radioactive waste disposal is currently investigated. For this application, hydraulic conductivity, swelling properties, water uptake, rheological and mechanical properties are of great importance. The Opalinus Clay (Mont-Terri, Switzerland) and the Callovo- Oxfordian clay stone (France) are the most frequently studied clay stones. One goal is to develop a numerical model being able to predict the mechanical behaviour of clay stones under repository-like conditions. Experimental investigations reveal that Opalinus Clay and Callovo-Oxfordian clay stone behave different with respect to the dependence of mechanical strength on the carbonate content. The failure strength of Opalinus Clay decreases with increasing carbonate content, whereas it increases with increasing carbonate content when Callovo-Oxfordian clay stone is considered. To supply proper data and enable reliable model assumptions, the use of suitable experimental techniques for the description of the microstructure is indispensable. After mechanical testing, samples were taken perpendicular to the bedding and polished sections were prepared. The micro-fabrics were investigated using scanning electron microscopy (SEM) and image analysis. Backscattered electron (BSE) images were used for the image analysis because carbonates can be extracted by grey level analysis. The image analysis of the extracted particles provides the following parameters: area, longest and shortest axis of an ellipse (surrounding the particle), perimeter, the angle to horizontal (longest axis), and the aspect ratio (longest axis/shortest axis). Callovo-Oxfordian clay stone shows a homogenous distribution of fine-grained carbonates and dovetail connection of calcium carbonate with the clayey matrix. In contrast Opalinus Clay shows large elongated carbonate grains (high aspect ratios) of shell fragments. Cracks are mostly related to these

  14. Multistep triaxial strength tests: investigating strength parameters and pore pressure effects on Opalinus Clay

    International Nuclear Information System (INIS)

    Graesle, W.

    2010-01-01

    Document available in extended abstract form only. The impact of natural variability between rock samples from a single formation is a common problem for the characterisation of THM properties of rocks. Data variation arising from heterogeneity between samples often obscures details of material behaviour. Besides efforts to reduce this statistical noise by careful selection of samples, there are essentially two approaches to overcome this problem: - To generate very large data sets for better statistics. - To avoid the impact of natural variability by yielding an extensive data set from a single sample. The multistep strength test follows the latter approach to characterise the mechanical behaviour of Opalinus Clay from Mont Terri and the possible impact of pore pressure effects. The concept of the multistep strength test comprises three test sections, each focused on the investigation of one mechanical characteristic of Opalinus Clay. Any section is composed of a series of strain controlled load cycles at various levels of confining pressure. 1) The linear elastic limit, i.e. the onset of nonlinearity in the stress-strain-relationship σ dev (ε 1 ) during strain-controlled triaxial loading, is determined in section 1. It defines a lower limit for the onset of damage. Avoiding sample damage is essential during this test section to ensure that all measurements reflect the behaviour of undisturbed material. Therefore, a rather strict and well detectable criterion for the onset of nonlinearity is required to enable a timely termination of any load phase. 2) Section 2 is focused on shear strength. Any load cycle is stopped as soon as peak stress is detected. As progressive damage of the sample is unavoidable during this process, it must be expected that only very few measured peak stresses approximately represent properties of the undamaged material. 3) Test section 3 is a conventional test of residual strength. Tests are carried out on cylindrical samples (100 mm

  15. Hydrogeology of a fractured shale (Opalinus Clay): Implications for deep geological disposal of radioactive wastes

    Science.gov (United States)

    Gautschi, Andreas

    2001-01-01

    As part of the Swiss programme for high-level radioactive-waste disposal, a Jurassic shale (Opalinus Clay) is being investigated as a potential host rock. Observations in clay pits and the results of a German research programme focusing on hazardous waste disposal have demonstrated that, at depths of 10-30 m, the permeability of the Opalinus Clay decreases by several orders of magnitude. Hydraulic tests in deeper boreholes (test intervals below 300 m) yielded hydraulic conductivities Las observaciones efectuadas en pozos en arcilla y los resultados de un programa de estudio alemán sobre eliminación de residuos peligrosos han demostrado que, a profundidades de entre 10 y 30 m, la permeabilidad de la Arcilla Opalina decrece en varios órdenes de magnitud. Los ensayos hidráulicos realizados en sondeos más profundos (en intervalos situados a más de 300 m) proporcionaron conductividades hidráulicas inferiores a 10-12 m/s, pese a que algunos de los intervalos interceptaban juntas y fallas. Estas medidas son coherentes con los datos hidrogeológicos de las secciones de Arcilla Opalina existentes en 10 túneles del Jurásico Plegado, al norte de Suiza. A pesar de las fallas extensivas, apenas se hallaron indicios de entrada de agua en los más de 6.600 m de túnel. Todos los flujos tenían lugar en secciones del túnel que soportan sobrecargas inferiores a 200 m. Los datos hidráulicos son coherentes con los datos hidroquímicos e isotópicos del agua intersticial de las arcillas. Los abundantes datos hidrogeológicos -parte de los cuales proceden de medios particularmente desfavorables desde el punto de vista geológico- proporcionan argumentos de que el transporte advectivo a través de fallas y juntas no es un aspecto crítico en lo que respecta a la idoneidad de la Arcilla Opalina como almacenamiento geológico profundo de residuos.

  16. In situ analysis of microbial reduction of a nitrate plume in Opalinus clay

    International Nuclear Information System (INIS)

    Bleyen, N.; Smets, S.; Valcke, E.; Albrecht, A.; De Canniere, P.; Schwyn, B.; Wittebroodt, C.

    2012-01-01

    Document available in extended abstract form only. In several countries, such as Belgium, France and Switzerland, clay formations are foreseen as the host rock for geological disposal of bituminized low-level and intermediate-level long-lived radioactive waste. Suitable clay formations exhibit favorable hydro-mechanical and geochemical characteristics, which are expected to retard the migration of leached radionuclides. Along with radionuclides, certain classes of bituminized radioactive waste may also contain high concentrations of NaNO 3 , dispersed into the hydrophobic bitumen matrix used to stabilize the waste. During and after saturation of the disposal gallery, this bituminized waste will start to take up water due to osmosis, resulting in the leaching of significant amounts of NaNO 3 and soluble organic bitumen degradation products (BDP) into the clay pore water. This nitrate plume could cause several geochemical and biochemical processes in the clay surrounding the waste disposal gallery, potentially affecting the barrier function of the host rock. To study these processes, an in situ experiment in the Opalinus Clay, named the Bitumen-Nitrate-Clay interaction (BN) experiment, is being performed at the Mont Terri Rock Laboratory (CH). The experiment consists of a vertical borehole rigged with a downhole equipment containing three packed-off intervals, each lined with a cylindrical sintered stainless steel filter screen to allow contact with the surrounding clay. Prior to the start of the tests, the intervals were injected with an artificial Opalinus Clay pore water, containing all major ions at pore water concentrations at Mont Terri, but no organic matter, and were equilibrated with the surrounding clay for ∼8 months. To ensure a continuous water flow during the tests, each interval is connected to a stainless steel water circulation unit, equipped with water sampling containers, circulation pumps and flow meters. In addition, to continuously monitor the

  17. Diffusion Experiments in Opalinus Clay: Laboratory, Large-Scale Diffusion Experiments and Microscale Analysis by RBS.

    Energy Technology Data Exchange (ETDEWEB)

    Garcia-Gutierrez, M.; Alonso de los Rios, U.; Missana, T.; Cormenzana, J.L.; Mingarro, M.; Morejon, J.; Gil, P.

    2008-08-06

    The Opalinus Clay (OPA) formation in the Zurcher Weiland (Switzerland) is a potential host rock for a repository for high-level radioactive waste. Samples collected in the Mont Terri Underground Rock Laboratory (URL), where the OPA formation is located at a depth between -200 and -300 m below the surface, were used to study the radionuclide diffusion in clay materials. Classical laboratory essays and a novel experimental set-up for large-scale diffusion experiments were performed together to a novel application of the nuclear ion beam technique Rutherford Backscattering Spectrometry (RBS), to understand the transport properties of the OPA and to enhance the methodologies used for in situ diffusion experiments. Through-Diffusion and In-Diffusion conventional laboratory diffusion experiments were carried out with HTO, 36{sup C}l-, I-, 22{sup N}a, 75{sup S}e, 85{sup S}r, 233{sup U}, 137{sup C}s, 60{sup C}o and 152{sup E}u. Large-scale diffusion experiments were performed with HTO, 36{sup C}l, and 85{sup S}r, and new experiments with 60{sup C}o, 137{sup C}s and 152{sup E}u are ongoing. Diffusion experiments with RBS technique were done with Sr, Re, U and Eu. (Author) 38 refs.

  18. Natural gas extraction and artificial gas injection experiments in Opalinus Clay, Mont Terri rock laboratory (Switzerland)

    Energy Technology Data Exchange (ETDEWEB)

    Vinsot, A.; Lundy, M. [Agence Nationale pour la Gestion des Déchets Radioactifs ANDRA, Meuse Haute-Marne Center, Bure (France); Appelo, C.A.J. [Dr C.A.J. Appelo, Hydrochemical Consultant, Amsterdam (Netherlands); and others

    2017-04-15

    Two experiments have been installed at Mont Terri in 2004 and 2009 that allowed gas circulation within a borehole at a pressure between 1 and 2 bar. These experiments made it possible to observe the natural gases that were initially dissolved in pore-water degassing into the borehole and to monitor their content evolution in the borehole over several years. They also allowed for inert (He, Ne) and reactive (H{sub 2}) gases to be injected into the borehole with the aim either to determine their diffusion properties into the rock pore-water or to evaluate their removal reaction kinetics. The natural gases identified were CO{sub 2}, light alkanes, He, and more importantly N{sub 2}. The natural concentration of four gases in Opalinus Clay pore-water was evaluated at the experiment location: N{sub 2} 2.2 mmol/L ± 25%, CH{sub 4} 0.30 mmol/L ± 25%, C{sub 2}H{sub 6} 0.023 mmol/L ± 25%, C{sub 3}H{sub 8} 0.012 mmol/L ± 25%. Retention properties of methane, ethane, and propane were estimated. Ne injection tests helped to characterize rock diffusion properties regarding the dissolved inert gases. These experimental results are highly relevant towards evaluating how the fluid composition could possibly evolve in the drifts of a radioactive waste disposal facility. (authors)

  19. Juveniles of the piscivorous dourado Salminus brasiliensis mimic the piraputanga Brycon hilarii as an alternative predation tactic

    Directory of Open Access Journals (Sweden)

    Eduardo Bessa

    Full Text Available In the district of Bom Jardim, in Nobres, Mato Grosso State, Brazil, there are clear water streams originating on karstic terrain. The dourado, Salminus brasiliensis, is an apex stalking predator in these streams. In clear waters, where visually oriented prey may perceive predator in advance, surprise is needed for successful attacks. These streams are cohabited by other Characiformes, like the frugivorous piraputanga Brycon hilarii, which lives in schools and exhibits body colour and shape similar to the dourados. Here we describe an alternative predatory tactic for juvenile dourado occurring in headwater streams of the Paraguay River basin, in which they act as an aggressive mimic of the piraputanga. Based on 43 h of observations in Bom Jardim, and on additional 11 h in the Bodoquena Plateau Rivers of Mato Grosso do Sul State, we quantified the number of rushes by dourados when they were among piraputangas or foraging alone, and observed the proportion of piraputangas per dourado in multispecific schools. Dourados of up to 30 cm total length (TL stayed among the piraputangas of similar size hiding within the school and going to the periphery of the school before rushing against prey. The dourados exhibited colours similar to the piraputangas. They not only stayed longer among piraputangas (78% of the observation time, but also rushed against prey more often than when foraging alone (53 rushes/h against 14 rushes/h, respectively.

  20. Population structure and connectivity of tiger sharks (Galeocerdo cuvier) across the Indo-Pacific Ocean basin

    DEFF Research Database (Denmark)

    Holmes, Bonnie J.; Williams, Samuel M.; Otway, Nicholas M.

    2017-01-01

    Population genetic structure using nine polymorphic nuclear microsatellite loci was assessed for the tiger shark (Galeocerdo cuvier) at seven locations across the Indo-Pacific, and one location in the southern Atlantic. Genetic analyses revealed considerable genetic structuring (FST > 0.14, p....001) between all Indo-Pacific locations and Brazil. By contrast, no significant genetic differences were observed between locations from within the Pacific or Indian Oceans, identifying an apparent large, single Indo-Pacific population. A lack of differentiation between tiger sharks sampled in Hawaii and other...... Indo-Pacific locations identified herein is in contrast to an earlier global tiger shark nDNA study. The results of our power analysis provide evidence to suggest that the larger sample sizes used here negated any weak population subdivision observed previously. These results further highlight the need...

  1. Aspectos biológicos de Diapterus rhombeus (Cuvier) (Teleostei, Gerreidae) na Baía de Guaratuba, Paraná, Brasil Biological aspects of Diapterus rhombeus (Cuvier) (Teleostei, Gerreidae) at Guaratuba Bay, Paraná, Brazil

    OpenAIRE

    Paulo de Tarso da Cunha Chaves; Gislaine Otto

    1998-01-01

    Diapterus rhombeus (Cuvier, 1829) is one of the most common Gerreidae species in the estuarine region at the Guaratuba Bay, Southern Brazil. Based on studies developed between July, 1993 and January, 1997, it was observed that its presence in the mangrove area is not regular: the smallest individuais are more abundam during late summer and in autumn, and the largest ones during spring and early summer. Its diet comprises plant material and invertebrates, specially polychaets. The morphologica...

  2. Experiments on thermo-hydro-mechanical behaviour of Opalinus Clay at Mont Terri rock laboratory, Switzerland

    Directory of Open Access Journals (Sweden)

    Paul Bossart

    2017-06-01

    Full Text Available Repositories for deep geological disposal of radioactive waste rely on multi-barrier systems to isolate waste from the biosphere. A multi-barrier system typically comprises the natural geological barrier provided by the repository host rock – in our case the Opalinus Clay – and an engineered barrier system (EBS. The Swiss repository concept for spent fuel and vitrified high-level waste (HLW consists of waste canisters, which are emplaced horizontally in the middle of an emplacement gallery and are separated from the gallery wall by granular backfill material (GBM. We describe here a selection of five in-situ experiments where characteristic hydro-mechanical (HM and thermo-hydro-mechanical (THM processes have been observed. The first example is a coupled HM and mine-by test where the evolution of the excavation damaged zone (EDZ was monitored around a gallery in the Opalinus Clay (ED-B experiment. Measurements of pore-water pressures and convergences due to stress redistribution during excavation highlighted the HM behaviour. The same measurements were subsequently carried out in a heater test (HE-D where we were able to characterise the Opalinus Clay in terms of its THM behaviour. These yielded detailed data to better understand the THM behaviours of the granular backfill and the natural host rock. For a presentation of the Swiss concept for HLW storage, we designed three demonstration experiments that were subsequently implemented in the Mont Terri rock laboratory: (1 the engineered barrier (EB experiment, (2 the in-situ heater test on key-THM processes and parameters (HE-E experiment, and (3 the full-scale emplacement (FE experiment. The first demonstration experiment has been dismantled, but the last two ones are on-going.

  3. Notas sobre la reproducción en cautiverio de Crocodylus acutus (Cuvier, 1807 en el Perú

    Directory of Open Access Journals (Sweden)

    Oswaldo Pérez

    2013-05-01

    Full Text Available Durante los años 2001 y 2002 se realizaron observaciones sobre la reproducción de Crocodylus acutus (Cuvier, 1807 en el Centro de Acuicultura La Tuna Carranza, localizado en Puerto Pizarro, departamento de Tumbes. El tamaño mínimo de una hembra anidando fue de 2,30 m. El porcentaje de viabilidad y natalidad fue de 61,71% y 93,15% respectivamente.

  4. Temporal and Spatial Distribution of Catches of Tiger Sharks, Galeocerdo cuvier, in the Pelagic Longline Fishery Around the Hawaiian Islands

    OpenAIRE

    Polovina, Jeffrey J.; Lau, Boulderson B.

    1993-01-01

    Thirty-five tiger sharks, Galeocerdo cuvier, have been reported caught in pelagic longline gearfrom 25 to 265 n.mi. off the Hawaiian Archipelago during December 1990-May 1993. Fifteen sharks were caught farther than 50 n.mi. offshore, indicating that tiger sharks do occur well offshore and removed from benthic topography. About 89% of the sharks were caught during October-March, while only 56% of the fishing effort occurred during that period.

  5. Excavation induced damage evolution during a mine-by experiment in Opalinus Clay

    International Nuclear Information System (INIS)

    Vietor, T.; Armand, G.; Nyonoya, S.; Schuster, K.; Wieczorek, K.

    2010-01-01

    Document available in extended abstract form only. In Switzerland Opalinus Clay, a potential host rock formation for a nuclear waste repository, is intensively studied in the Mont Terri Underground Rock Laboratory (URL) in North-Western Switzerland. During the 2008 extension of the URL, the construction works were repeatedly interrupted to implement monitoring systems for a mine-by experiment. The future position of a 24 m long tunnel was instrumented with 36 different monitoring systems comprising approximately 200 sensors. Key features of this tunnel were chosen similar to the current Swiss concept for emplacement tunnels for High Level Radioactive Waste: circular section, full-face excavation following the geological bedding, support by a thin layer of shotcrete and 6 anchors every 1.3 m. For a mine-by experiment 26 boreholes were equipped with 7 multipoint extensometers, two multi segment inclinometer chains and 26 pore pressure chambers. The data acquisition system recorded 12 data sets per hour. For seismic transmission and acoustic emission monitoring, 8 piezo-electric emitters and 15 piezo-electric receivers were installed in 5 boreholes. The excavation of the instrumented tunnel took place in October/November 2008. The activities on the site were monitored with a web cam to separate spontaneous and excavation induced rock mass reactions. Daily mappings of the tunnel face and the sidewalls revealed the fracture pattern that was generated ahead of the advancing excavation. Three sets of excavation activated discontinuities could be clearly identified. These three sets develop within the framework of the pre-existing tectonic micro-faults that generally have a half-meter spacing. Where their density is high the intensity of excavation induced new slip planes apparently drops. Despite the presence of micro-faults the deformation monitoring around the advancing tunnel face showed a remarkably homogenous response to the excavation. Inclinometer chain segments

  6. Microbiological analysis of the in situ bitumen-nitrate-Opalinus clay interaction

    International Nuclear Information System (INIS)

    Moors, Hugo; Boven, Patrick; Leys, Natalie; Geissler, Andrea; Selenska-Pobell, Sonja

    2012-01-01

    Document available in extended abstract form only. Clay formations like the Opalinus Clay are foreseen to serve as the host rock for geological disposal of high and intermediate-level long-lived radioactive waste in several countries, because of their favourable properties to delay the migration of radionuclides over time. However, bituminized intermediate-level long-lived radioactive waste may physico-chemically perturb the clay barrier properties because in time it will leach substantial amounts of nitrate and organic bitumen degradation products (BDP). To study the physico-chemical impact of intermediate-level radioactive waste containing bitumen and nitrate, an in situ experiment in the Opalinus Clay (Saint Ursanne, Switzerland) named the Bitumen-Nitrate- Clay interaction (BN) experiment, is being performed at the Mont Terri Rock Laboratory. The in situ equipment of the BN-experiment consists of three separate packed-off intervals, supplied with a filter screen. Each interval is equipped with its own stainless steel water circulation unit. Such water circulation unit contains water sampling containers, circulation pumps and flow meters. One of the circulation units is equipped with an on-line UV spectrophotometer and pH electrode intervals, allowing a continuous monitoring of nitrate, nitrite concentrations, organic carbon level and pH. In a first series of tests, the microbial and biogeochemical effect of a nitrate and/or acetate perturbation is studied. Acetate is used as it a good representation of BDP. Hereto, nitrate was injected in interval 1 while a mixture of nitrate and acetate is injected in interval 2. As an active microbial community can have a significant impact on the physical and (geo)chemical conditions of the clay surrounding the disposal gallery, microbial analyses were performed on samples taken from the interval solutions before, during and after this first series of tests. Our microbial investigations which included Scanning Electron

  7. Microbiological analysis of the in situ bitumen-nitrate-Opalinus clay interaction

    Energy Technology Data Exchange (ETDEWEB)

    Moors, Hugo; Boven, Patrick; Leys, Natalie [SCK.CEN, Institute for Environment, Health and Safety, Laboratory for Molecular and Cellular Biology, Boeretang 200, B-2400 MOL (Belgium); Geissler, Andrea; Selenska-Pobell, Sonja [Helmholtz Zentrum Dresden Rossendorf, Institute of Radiochemistry, Biogeochemistry, Bautzner Landstr. 400, D-01328 Dresden (Germany)

    2012-10-15

    Document available in extended abstract form only. Clay formations like the Opalinus Clay are foreseen to serve as the host rock for geological disposal of high and intermediate-level long-lived radioactive waste in several countries, because of their favourable properties to delay the migration of radionuclides over time. However, bituminized intermediate-level long-lived radioactive waste may physico-chemically perturb the clay barrier properties because in time it will leach substantial amounts of nitrate and organic bitumen degradation products (BDP). To study the physico-chemical impact of intermediate-level radioactive waste containing bitumen and nitrate, an in situ experiment in the Opalinus Clay (Saint Ursanne, Switzerland) named the Bitumen-Nitrate- Clay interaction (BN) experiment, is being performed at the Mont Terri Rock Laboratory. The in situ equipment of the BN-experiment consists of three separate packed-off intervals, supplied with a filter screen. Each interval is equipped with its own stainless steel water circulation unit. Such water circulation unit contains water sampling containers, circulation pumps and flow meters. One of the circulation units is equipped with an on-line UV spectrophotometer and pH electrode intervals, allowing a continuous monitoring of nitrate, nitrite concentrations, organic carbon level and pH. In a first series of tests, the microbial and biogeochemical effect of a nitrate and/or acetate perturbation is studied. Acetate is used as it a good representation of BDP. Hereto, nitrate was injected in interval 1 while a mixture of nitrate and acetate is injected in interval 2. As an active microbial community can have a significant impact on the physical and (geo)chemical conditions of the clay surrounding the disposal gallery, microbial analyses were performed on samples taken from the interval solutions before, during and after this first series of tests. Our microbial investigations which included Scanning Electron

  8. Anisotropic Diffusion In Layered Argillaceous Rocks: A Case Study With Opalinus Clay

    International Nuclear Information System (INIS)

    Van Loon, L.R.; Soler, J.; Mueller, W.; Bradbury, M.H.

    2003-01-01

    Anisotropic diffusion was studied in Opalinus Clay, a potential host rock for the disposal of spent fuel, vitrified high-level waste and intermediate-level waste. Diffusion parallel to the bedding was measured using a radial through-diffusion technique, while diffusion perpendicular to the bedding was measured using the classical (planar) through-diffusion method. The materials used were samples from Mont Terri (MT) and Benken (BE), respectively. Diffusion of Tritiated Water (HTO), parallel and perpendicular to the bedding, was studied under confining pressures of 7 MPa (MT) and 14 MPa (BE), respectively. The effective diffusion coefficient for diffusion parallel to the bedding, D e , was found to be 3.20(±0.26)x10 11 m 2 s -1 and for the Benken 5.39(±0.43)x10 -11 m 2 s-1 for the Mont Terri samples. The diffusion accessible porosity was ∼ 0.15(±0.02) in both cases. For diffusion perpendicular to the bedding, the effective diffusion coefficient was 5.44(±0.35)x10 -12 m 2 s-1 and 1.37(±0.08)x10 -11 m 2 s -1 for the Benken and Mont Terri samples, respectively. The diffusion accessible porosity was also ∼0.15(±0.02) in both cases. These first results indicate that diffusion parallel to bedding is larger than that perpendicular to the bedding by a factor of 4 to 6. This might be explained in terms of smaller path lengths (tortuosity) for species diffusing parallel to the fabric. (author)

  9. Sorption of neptunium(V) on opalinus clay under aerobic/anaerobic conditions

    International Nuclear Information System (INIS)

    Froehlich, D.R.; Amayri, S.; Drebert, J.; Reich, T.

    2011-01-01

    The interaction between neptunium(V) and a natural argillaceous rock (Opalinus Clay (OPA), Mont Terri, Switzerland) has been investigated in batch sorption experiments by varying pH (6-10), Np(V) concentration (10 -12 -10 -4 M), solid-to-liquid ratio (2-20 g/L), and partial pressure of CO 2 (10 -3.5 and 10 -2.3 atm) under aerobic/anaerobic conditions in saturated calcite solution. All batch experiments were carried out using well characterized aerobic and anaerobic dry powders of OPA. The results show a great influence of pH on Np(V) sorption. Under aerobic conditions sorption increases with increasing pH until maximum sorption is reached between pH 8-9. At pH > 9 sorption decreases due to the formation of negatively charged Np(V)-carbonate complexes. By increasing p CO 2 from 10 -3.5 to 10 -2.3 atm, the sorption edge is shifted ∼ 0.5 units to lower pH values. Under anaerobic conditions stronger sorption of 8 x 10 -6 M Np(V) was found, possibly due to partial reduction of Np(V) to Np(IV). The sorption of 8 x 10 -6 M Np(V) under aerobic conditions at pH 8.2 in saturated calcite solution increases continuously with increasing solid-to-liquid ratio of OPA in the range of 2-20 g/L with a constant K d value of 126 ± 13 L/kg. The sorption isotherm was measured over seven orders of magnitude in Np(V) concentration using 239 Np as tracer. The sorption isotherm could be divided in a part of linear sorption behaviour between 10 -13 -10 -9 M Np(V) and non-linear behaviour in the range of 10 -9 -10 -4 M Np(V). (orig.)

  10. Anisotropic Diffusion In Layered Argillaceous Rocks: A Case Study With Opalinus Clay

    Energy Technology Data Exchange (ETDEWEB)

    Van Loon, L.R.; Soler, J.; Mueller, W.; Bradbury, M.H

    2003-03-01

    Anisotropic diffusion was studied in Opalinus Clay, a potential host rock for the disposal of spent fuel, vitrified high-level waste and intermediate-level waste. Diffusion parallel to the bedding was measured using a radial through-diffusion technique, while diffusion perpendicular to the bedding was measured using the classical (planar) through-diffusion method. The materials used were samples from Mont Terri (MT) and Benken (BE), respectively. Diffusion of Tritiated Water (HTO), parallel and perpendicular to the bedding, was studied under confining pressures of 7 MPa (MT) and 14 MPa (BE), respectively. The effective diffusion coefficient for diffusion parallel to the bedding, D{sub e}, was found to be 3.20({+-}0.26)x10{sup 11} m{sup 2}s{sup -1} and for the Benken 5.39({+-}0.43)x10{sup -11} m{sup 2}s-1 for the Mont Terri samples. The diffusion accessible porosity was {approx} 0.15({+-}0.02) in both cases. For diffusion perpendicular to the bedding, the effective diffusion coefficient was 5.44({+-}0.35)x10{sup -12} m{sup 2}s-1 and 1.37({+-}0.08)x10{sup -11} m{sup 2}s{sup -1} for the Benken and Mont Terri samples, respectively. The diffusion accessible porosity was also {approx}0.15({+-}0.02) in both cases. These first results indicate that diffusion parallel to bedding is larger than that perpendicular to the bedding by a factor of 4 to 6. This might be explained in terms of smaller path lengths (tortuosity) for species diffusing parallel to the fabric. (author)

  11. Feeding and social behavior of the piabanha, Brycon devillei (Castelnau, 1855 (Characidae: Bryconinae in the wild, with a note on following behavior

    Directory of Open Access Journals (Sweden)

    Pedro G Azevedo

    Full Text Available Knowledge concerning the behavior of wild freshwater fishes in Brazil is restricted to a few studies, despite such studies being able to answer fundamental questions about conservation. Species of Brycon are amongst the most threatened in the Neotropics, particularly in southeast Brazil, due to anthropogenic activities in this region. This study investigated the feeding and social behaviors of the endangered fish, Brycon devillei in the Preto River, Jequitinhonha basin, Minas Gerais State, Brazil. Behavioral data were collected by snorkeling with four spatially separated groups (habituated, and direct observations of shoals were made using an underwater video camera (a total of 448 hours of observations. This species showed diverse tactics to obtain food. However, the species proved to be predominately a specialist surface-picker, which adopted alternative tactics to find food at certain times of the year, most notably when food items on the water surface became low. Feeding frequency was shown to be negatively correlated to agonistic behavior between conspecifics. Feeding associations were also recorded between the anostomid Leporinus garmani, acting as a nuclear species, and B. devillei, as follower species. The data presented here showed the importance of conserving the riparian environment to protect B. devillei populations. Furthermore, the present study included rare observations of nuclear-follower feeding association among freshwater fishes, especially between medium-sized characiforms, being the first observations of such kind in a Cerrado stream.

  12. Comportamento reprodutivo do acará bandeira, Pterophyllum scalare Cuvier & Valenciennes (Osteichthyes, Cichlidae Reproductive behaviour of Pterophyllum scalare Cuvier & Valenciennes (Osteichthyes, Cichlidae

    Directory of Open Access Journals (Sweden)

    Maria do Socorro R.F Cacho

    1999-01-01

    Full Text Available Acará bandeira, Pterophyllum scalare Cuvier & Valenciennes, 1831 is a Neotropical cichlid fish, which has not been studied under a scientific approach. The objective of this work was to identify and describe the reproductive behaviour involved in the various phases of its reproductive cycle, such as territorial disputes and its establishment, substrate selection for spawning, courtship and mating, selection of mate and parental care. Twenty males and ten females of the study species were observed in the laboratory, over a period of six consecutive months. Behaviour descriptions resulting from these observations were analysed and the results show that the reproductive males are very agressive in the initial phase of reproduction. Agressiveness is a constant variable in encounters between territorial fishes, and possession of territory is of fundamental importance for reproduction of this species. Males with established territories were those which very successful in atracting the females during courtship. The selection of the females were influenced by the possession of territory, the type of substrate available for spawning and the body size. The fish preferred aquatic plants with broad leaves as an adequate substrate for spawning. It was observed that there was a short-term biparental care, before the eggs hatched, during which period the males played an important role in protecting them. After the eggs hatched, the male continued to protect the hatchling in his mouth, but played a lesser role, possibly to seek other females for mating so as to increase his reproductive output. Selection of a good mate by the female and the high degree of parental care were the factors which influence the reproductive success of the study species.

  13. Juveniles of the piscivorous dourado Salminus brasiliensis mimic the piraputanga Brycon hilarii as an alternative predation tactic

    Directory of Open Access Journals (Sweden)

    Eduardo Bessa

    2011-06-01

    Full Text Available In the district of Bom Jardim, in Nobres, Mato Grosso State, Brazil, there are clear water streams originating on karstic terrain. The dourado, Salminus brasiliensis, is an apex stalking predator in these streams. In clear waters, where visually oriented prey may perceive predator in advance, surprise is needed for successful attacks. These streams are cohabited by other Characiformes, like the frugivorous piraputanga Brycon hilarii, which lives in schools and exhibits body colour and shape similar to the dourados. Here we describe an alternative predatory tactic for juvenile dourado occurring in headwater streams of the Paraguay River basin, in which they act as an aggressive mimic of the piraputanga. Based on 43 h of observations in Bom Jardim, and on additional 11 h in the Bodoquena Plateau Rivers of Mato Grosso do Sul State, we quantified the number of rushes by dourados when they were among piraputangas or foraging alone, and observed the proportion of piraputangas per dourado in multispecific schools. Dourados of up to 30 cm total length (TL stayed among the piraputangas of similar size hiding within the school and going to the periphery of the school before rushing against prey. The dourados exhibited colours similar to the piraputangas. They not only stayed longer among piraputangas (78% of the observation time, but also rushed against prey more often than when foraging alone (53 rushes/h against 14 rushes/h, respectively.No distrito de Bom Jardim, Nobres, Mato Grosso, Brasil, existem rios de águas claras que se originam sobre terreno cárstico. O dourado, Salminus brasiliensis, é um predador perseguidor de topo de cadeia nestes rios. Em águas, onde presas visualmente orientadas são capazes de perceber antecipadamente o predador, o fator surpresa é necessário para ataques bem sucedidos. Estes córregos são coabitados por outros Characiformes, como a frugívora piraputanga, Brycon hilarii, a qual vive em cardumes e exibe colora

  14. Caracterización de la diversidad genética en el pez Brycon henni (Characiformes: Characidae en Colombia central por medio de marcadores RAPD

    Directory of Open Access Journals (Sweden)

    Hermes Pineda Santis

    2007-12-01

    Full Text Available El conocimiento sobre la diversidad genética de especies nativas de peces, es esencial para la conservación y manejo apropiado de animales en los programas de repoblación. Brycon henni ha sido reportada en las cuencas de los ríos Magdalena y Cauca; actualmente, la especie ha disminuido su número de animales y reducido su distribución geográfica como consecuencia de los efectos antrópicos. Por lo tanto, es necesario conocer el componente genético de los reducidos grupos de animales en los riachuelos, para iniciar algunos programas de repoblación. En este estudio el Polimorfismo de ADN Amplificado al Azar (RAPD, fue utilizado para estimar el componente genético actual en esta especie. Para este propósito; se evaluaron seis sitios de muestreo localizados en el departamento de Antioquia, cordillera Central de Colombia. De cuarenta iniciadores utilizados, treinta y cinco de ellos (87.5 % produjeron 1 466 fragmentos reproducibles y consistentes; 417 fueron considerados como fragmentos únicos, que permitieron discriminar entre las muestras de las cuencas de los ríos Magdalena (Humarada-1 y Humarada-2 y Cauca (Piedras, La Clara y Guaracú, sugiriendo que cada una es una unidad discreta. Esta diversidad en los resultados, según el sitio de muestreo y por las características de cada uno de ellos, posiblemente sugiere, que los efectos antrópicos como presión por pesca, construcción de embalses, deforestación y contaminación del agua, han contribuido al aislamiento de estos grupos de peces en las zonas de alta montaña. Brycon moorei y Colossoma macropomum, como grupos de control inter especifico, se ubicaron fuera del grupo general de B. henni, confirmando su clasificación taxonómica mediante datos morfológicos. La técnica de RAPD fue útil para conocer la diversidad genética y discriminar entre poblaciones de B. henni de diferente origen geográfico, ello permitiría realizar un plan apropiado de conservación y manejo en medio

  15. Sperm cryopreservation affects postthaw motility, but not embryogenesis or larval growth in the Brazilian fish Brycon insignis (Characiformes).

    Science.gov (United States)

    Viveiros, A T M; Isaú, Z A; Caneppele, D; Leal, M C

    2012-09-01

    Sperm cryopreservation is an important method for preserving genetic information and facilitating artificial reproduction. The objective was to investigate whether the cryopreservation process affects postthaw sperm motility, embryogenesis, and larval growth in the fish Brycon insignis. Sperm was diluted in methyl glycol and Beltsville Thawing solution, frozen in a nitrogen vapor vessel (dry shipper) and stored in liquid nitrogen. Half of the samples were evaluated both subjectively (% of motile sperm and motility quality score-arbitrary grading system from 0 [no movement] to 5 [rapidly swimming sperm]) and in a computer-assisted sperm analyzer (CASA; percentage of motile sperm and velocity). The other half was used for fertilization and the evaluation of embryogenesis (cleavage and gastrula stages), hatching rate, percentage of larvae with normal development and larval growth up to 112 days posthatching (dph). Fresh sperm was analyzed subjectively (percentage of motile sperm and motility quality score) and used as the control. In the subjective analysis, sperm motility significantly decreased from 100% motile sperm and quality score of 5 in fresh sperm to 54% motile sperm and quality score of 3 after thawing. Under computer-assisted sperm analyzer evaluation, postthaw sperm had 67% motile sperm, 122 μm/sec of curvilinear velocity, 87 μm/sec of straight-line velocity and 103 μm/sec of average path velocity. There were no significant differences between progenies (pooled data) for the percentage of viable embryos in cleavage (62%) or gastrula stages (24%) or in the hatching rate (24%), percentage of normal hatched larvae (93%), larval body weight (39.8 g), or standard length (12.7 cm) at 112 days posthatching. Based on these findings, cryopreserved sperm can be used as a tool to restore the population of endangered species, such as B. insignis, as well as for aquaculture purposes, without any concern regarding quality of the offspring. Copyright © 2012 Elsevier

  16. VARIABILIDAD GENÉTICA DE LOTES DE Brycon orbignyanus UTILIZADOS EN PROGRAMAS DE REPOBLAMIENTO: MANEJO Y CONSERVACIÓN

    Directory of Open Access Journals (Sweden)

    NELSON M LOPERA-BARRERO

    2008-01-01

    Full Text Available Alteraciones ambientales causadas por el calentamiento global y principalmente causa-das por la acción del hombre, han reducido poblaciones naturales de peces. Como forma de conservación, programas de repoblamiento han sido utilizados; sin embargo, sin una debida orientación científica, estas medidas pueden generar disturbios genéticos sobre la diversidad genética de poblaciones de peces naturales y sobre el ecosistema. El objetivo de este estudio fue estimar y analizar la variabilidad genética de dos lotes y una progenie de Brycon orbignyanus utilizados en programas de repoblamiento, utilizando el marcador molecular RAPD (Random Amplified Polymorphic DNA. Cincuenta y ocho reproductores de dos lotes (A y C y 30 larvas de la progenie del lote A (B pertenecientes a la Estação de Aqüicultura e Hidrologia da Duke Energy Internacional (Geração Parana-panema; São Paulo, Brasil fueron analizados. Los resultados de variabilidad genética estimados por el índice de diversidad de Shannon (A: 0,3184; B: 0,3433 y C: 0,3687 y por el porcentaje de fragmentos polimórficos (A: 54,02%; B: 57,47% y C: 58,62% mostraron que la variabilidad genética fue mantenida en la progenie, debido posiblemente al adecuado manejo reproductivo y al efecto fundador. Por el contrario, la variabilidad encontrada entre los dos lotes de reproductores indica una similaridad genética, a pesar de ser originarios de diferentes pisciculturas. Este resultado es comprobado en el valor moderado de diferenciación genética encontrado (0,0968, en el alto Nm (4,67 y en el dendrograma, que sugieren que los lotes poseen un pool genético similar

  17. APRENDIENDO Y JUGANDO CON AQUATAMBO, UNA PROPUESTA DIDÁCTICA BASADA EN LA BIOLOGÍA REPRODUCTIVA DEL PEZ BRYCON

    Directory of Open Access Journals (Sweden)

    DARÍO ÁLVAREZ

    2013-01-01

    Full Text Available En este trabajo se presenta el procedimiento empleado para la construcción de un juego didáctico que permita a los docentes de Ciencias Naturales y Educación Ambiental, estimular en sus estudiantes actitudes favorables para la conservación del recurso hídrico a partir del conocimiento que adquieren sobre este y las diferentes interacciones con los seres vivos. El juego se diseñó teniendo como centro la biología reproductiva del pez Brycon henni, conocido en la región como Sabaleta, y se aplicó a estudiantes de grado sexto y séptimo de la Institución Educativa Rural El Tambo, localizada en el municipio de San Pedro de los Milagros, en el departamento de Antioquia (Colombia. El diseño metodológico parte de considerar las preferencias y carencias de los estudiantes de la comunidad académica, continúa con la selección de los postulados teóricos de Vygotsky, Piaget y Ausubel asociados al aprendizaje a través del juego, incorporando estos elementos desde el contexto local y concluye con la evaluación de la aplicación del instrumento. El uso del instrumento demostró favorecer el aprendizaje, tal como lo indica un test aplicado antes y después de haberse jugado en el que se observa un incremento del 18 % en respuestas acertadas.

  18. VALOR AGREGADO DE LAS ESPECIES Brycon erythropterum (SÁBALO, Colossoma macropomum (GAMITANA, Arapaima gigas (PAICHE y Agouti paca (MAJAS

    Directory of Open Access Journals (Sweden)

    Doylith Vásquez Jurafo

    2012-12-01

    Full Text Available El presente trabajo tiene como objetivo la obtención de productos mínimamente procesados (PMP de Brycon erythropterum (SÁBALO, Colossoma macropomum (GAMITANA, Arapaima gigas (PAICHE, y Agouti paca (MAJAS congelado y empacado al vacio. Para las especies piscícolas, se ha aplicado un diseño factorial de 32 con dos factores de estudios: concentración de NaCl en la solución osmótica con tres niveles (15, 20 y 25 % y temperatura de proceso con tres niveles de estudio (5, 10 y 15 °C. Para el Agouti paca (majas se aplicó un diseño factorial completamente aleatorizado con tres factores de estudio: tiempo de proceso (30, 60 y 90 minutos, método de ahumado (ahumado líquido y ahumado en caliente y tipo de corte del músculo (partes y filetes. Para trabajar se ha diseñado y montado un deshidratador Osmótico teniendo en cuenta, diámetro de tubería, deshidratador propiamente dicho con doble chaqueta, capacidad del deshidratador en función del volumen de la Salmuera.  Todos los productos se obtuvieron en procesos con 10 °C y tiempos entre 30 min y 90 min. El tiempo de vida en almacenamiento en las evaluaciones de aroma y color en majas tienen una vida útil de 4 meses de almacenados a -18 °C. Los análisis microbiológicos realizados a los PMP no pasan los límites de la NTS Nº 071 MINSA/DIGESA V01.

  19. VALOR AGREGADO DE LAS ESPECIES Brycon erythropterum (SÁBALO, Colossoma macropomum (GAMITANA, Arapaima gigas (PAICHE y Agouti paca (MAJAS

    Directory of Open Access Journals (Sweden)

    Doylith Vásquez Jurafo

    2012-12-01

    Full Text Available El presente trabajo tiene como objetivo  la obtención de  productos mínimamente procesados (PMP de Brycon erythropterum (SÁBALO, Colossoma macropomum (GAMITANA, Arapaima gigas (PAICHE, y Agouti paca (MAJAS congelado y empacado al vacio. Para las especies piscícolas, se ha aplicado un diseño factorial de 32 con dos factores de estudios: concentración de NaCl en la solución osmótica con tres niveles (15, 20 y 25 % y temperatura de proceso  con tres niveles de estudio (5, 10 y 15 °C. Para el Agouti paca (majas se aplico un diseño factorial completamente aleatorizado con tres factores de estudio: tiempo de proceso (30, 60 y 90 minutos, método de ahumado (ahumado líquido y ahumado en caliente y tipo de corte del músculo (partes y filetes. Para trabajar se ha diseñado y montado un deshidratador Osmótico teniendo en cuenta, diámetro de tubería, deshidratador propiamente dicho con doble chaqueta, capacidad del deshidratador en función del volumen de la Salmuera.  Todos los productos se obtuvieron  en procesos con 10 °C y tiempos entre 30 min y  90 min. El tiempo de vida en almacenamiento en las evaluaciones de aroma y color en majas tienen una vida útil de 4 meses de almacenados a -18 °C. Los análisis microbiológicos realizados a los PMP no pasan los límites de la NTS Nº 071 MINSA/DIGESA V01.

  20. Physico-chemical characterisation and sorption measurements of Cs, Sr, Ni, Eu, Th, Sn and Se on Opalinus clay from Mont Terri

    International Nuclear Information System (INIS)

    Lauber, Matthias; Baeyens, Bart; Bradbury, Michael H.

    2000-12-01

    Opalinus Clay is currently under investigation as a potential host rock for the disposal of high level and long-lived intermediate radioactive waste. A throughout physico-chemical characterisation was carried out on a bore core sample from the underground rock laboratory Mont Terri (Canton Jura). The results of these investigations indicate that the major characteristics (mineralogy, cation exchange capacity, cation occupancies, selectivity coefficients, chloride and sulphate inventories) were very similar to a different core sample, previously used for pore water modelling studies. It was concluded that the pore water compositions derived in the earlier studies were reliable and could be used in this work. The organic matter which dissolved from the Opalinus Clay rock was not humic or fulvic acids and the concentration remaining in the liquid phase in the sorption experiments was < 0.5 ppm C. The organic matter is therefore considered to have little or no influence on the sorption behaviour of the studied radionuclides. Redox potential measurements of the Opalinus Clay/synthetic pore water system inside the glove boxes indicated anoxic conditions. The main focus of the experimental work presented here is on the sorption behaviour of Cs (I), Sr (II), Ni (II), Eu (III), Th (IV), Sn (IV) and Se (IV) on Opalinus Clay equilibrated with synthetic pore waters at pH 6.3 and 8. Sorption isotherms were measured for Cs, Ni, Eu, Th and Se. Single point data were measured for Sr and Sn. For all radionuclides studied the sorption kinetics were measured first. The times required to complete the sorption on the Opalinus Clay varied between one day for Th and one month for Ni and Se. Within the concentration ranges under study the uptake of Cs, Ni, Eu and Se on Opalinus Clay was non-linear, whereas for Th a linear sorption behaviour was observed. For Ni, Eu and Th the sorption increased with increasing pH. For Cs a pH independent sorption behaviour was observed. The concentration

  1. Efeito do resfriamento sobre a textura post-mortem da carne do peixe matrinxã Brycon cephalus Chilling effect on the post-mortem texture of the matrinxã fish muscle Brycon cephalus

    Directory of Open Access Journals (Sweden)

    H. Suárez-Mahecha

    2007-08-01

    Full Text Available Os mecanismos que causam o amolecimento e a perda na textura post-mortem da carne de matrinxã foram determinados por meio das mudanças na microestrutura do músculo, imediatamente após a morte e depois de 12 horas de estocagem a -3°C. As observações na microestrutura, realizadas com microscópio eletrônico de transmissão, foram semelhantes aos resultados obtidos na força de ruptura do músculo medidos com o texturômetro. Os valores da força da ruptura foram menores para a carne após o resfriamento. Observou-se que as fibras do colágeno do tecido conectivo pericelular se desintegraram e que as do colágeno do tecido conectivo do miocommata conservaram sua arquitetura e integridade. Houve pouca degradação da linha Z. Isso sugere que o amolecimento post-mortem da carne de mantrinxã, durante a estocagem a -3°C, é causado pela degradação do tecido conectivo pericelular.In order to determine the mechanisms that cause the post mortem muscle softness of the matrinxã Brycon cephalus, changes in the micro structure of the muscle were observed immediately after death and after 12 hours of storage at -3º C, measuring the firmness of the flesh with test instruments. Observations by the transmission electron microscope were similar to the results obtained in the breaking strength of the muscle measured with a texturometer. The values of the breaking strength of the fish muscle were smaller after chilling. At the same time, it was observed that the collagen fibers of the pericellular connective tissue had disintegrated, while the collagen fibers of the miocommata connective tissue maintained their organization and integrity. No evident breakdown of Z-discs was observed. It is suggested that the post-mortem tenderization of the matrinxã muscle during chilled storage was due to the disintegration of the collagen fibers in the pericellular connective tissue and, in a smaller extent, to the weakening of Z-disk.

  2. Utilização da fibra bruta na nutrição da piracanjuba (Brycon orbignyanus Effect of crude fiber on the nutrition of piracanjuba (Brycon orbignyanus

    Directory of Open Access Journals (Sweden)

    Evoy Zaniboni Filho

    1999-11-01

    Full Text Available Este experimento teve por objetivo avaliar o desempenho da piracanjuba, quando arraçoada com dietas contendo diferentes níveis de fibra bruta. Empregou-se um lote de 60 alevinos, com peso médio de 17,40±3,06g e comprimento padrão médio de 11,70±0,73cm, alojados em 12 aquários circulares de fibra de vidro com capacidade para 150L e numa lotação de cinco peixes por aquário, com abastecimento de água proporcionado por um sistema de circulação fechada. Utilizaram-se rações com semelhante composição em proteína (32%, níveis de energia que variaram de 3.037 a 3.356 kcal ED/kg de ração e níveis crescentes de fibra bruta (5%, 7%, 8% e 9% por 105 dias. Constatou-se que os peixes apresentaram melhor resposta de ganho de peso, quando arraçoados com dietas contendo 9% de fibra bruta e que a utilização de níveis de fibra bruta, acima dos convencionalmente empregados, proporcionou baixos níveis de gordura na carcaça, sem que houvesse prejuízos ao desempenho zootécnico, e que as rações podem ser elaboradas empregando-se subprodutos de origem vegetal ricos em fibra bruta.The present experiment evaluated the performance of Brycon orbignyanus fed on diets with different levels of crude fiber. Fish with mean weight of 17.40±3.06 g and total length of 11.70±0,73cm were stocked in 12 fiberglass aquariums (150 L fitted with center standpipes in a recirculating system at a density of 5 fish/aquarium. The fish were fed four diets containing similar levels of protein (32%, energy levels varyng from 3,037 to 3,356 kcal DE/kg, and crude fiber levels of 5%; 7%; 85 and 9% for 105 days. The fish had better weight gain when fed diet containing 9% of crude fiber, and it can be concluded that fish fed diets containing higher levels of crude fiber than usually used result in fish with less fat on carcass without loss of growth, and by products of plant origin rich in fiber could be used to produce diets for this kind of fish.

  3. Age and growth of the fish, Gerres filamentosus (Cuvier, 1829 from Hurghada Red Sea, Egypt

    Directory of Open Access Journals (Sweden)

    Taher Mohamed Ahmed Abu El-Nasr

    2017-09-01

    Full Text Available A total of 669, Gerres filamentosus (Cuvier, 1829 were collected from Hurghada area in the Egyptian Red Sea coast (January – December 2010. The author investigated the age and growth by two different methods through scale-annuli reading (Direct method and Length-frequency distribution (Indirect method which showed new record of lengths for the species. The equations of the length-weight relationship was W = 0.0143∗ L2.9564 (Males, W = 0.0146∗ L2.9543 (Females and W = 0.0144∗ L2.9597 (combined sexes. The von Bertalanffy growth equation was calculated by three different mathematical methods. It was concluded that it would be economical to protect this species from capture until at least their 5th year, after the fish has reached about 32.71 cm in total length and about 439.15 grams in weight. Keywords: Mojarra, Whipfin, Silver-biddy, Length-weight, Age groups, Frequency distribution

  4. Vertical movement patterns and ontogenetic niche expansion in the tiger shark, Galeocerdo cuvier.

    Science.gov (United States)

    Afonso, André S; Hazin, Fábio H V

    2015-01-01

    Sharks are top predators in many marine ecosystems and can impact community dynamics, yet many shark populations are undergoing severe declines primarily due to overfishing. Obtaining species-specific knowledge on shark spatial ecology is important to implement adequate management strategies for the effective conservation of these taxa. This is particularly relevant concerning highly-mobile species that use wide home ranges comprising coastal and oceanic habitats, such as tiger sharks, Galeocerdo cuvier. We deployed satellite tags in 20 juvenile tiger sharks off northeastern Brazil to assess the effect of intrinsic and extrinsic factors on depth and temperature usage. Sharks were tracked for a total of 1184 d and used waters up to 1112 m in depth. The minimum temperature recorded equaled 4°C. All sharks had a clear preference for surface (sharks used mostly shallow (sharks spending considerably more time in surface (shark habitat was observed, with generalized linear models estimating a ~4-fold increase in maximum diving depth from 150- to 300-cm size-classes. The time spent in the upper 5 m of the water column did not vary ontogenetically but shark size was the most important factor explaining the utilization of deeper water layers. Young-of-the-year tiger sharks seem to associate with shallow, neritic habitats but they progressively move into deeper oceanic habitats as they grow larger. Such an early plasticity in habitat use could endow tiger sharks with access to previously unavailable prey, thus contributing to a wider ecological niche.

  5. Octopus vulgaris (Cuvier, 1797) in the Mediterranean Sea: Genetic Diversity and Population Structure.

    Science.gov (United States)

    De Luca, Daniele; Catanese, Gaetano; Procaccini, Gabriele; Fiorito, Graziano

    2016-01-01

    The common octopus, Octopus vulgaris Cuvier 1797, is a largely exploited cephalopod species in the Mediterranean Sea and the Atlantic Ocean, as well as along the coasts of Africa, Brazil and Japan, where its taxonomic identity is still debated. The assessment of its genetic structure is a pressing need to correctly manage the resource and to avoid overfishing and collapsing of local stocks. Here we analysed genetic variation and population structure of O. vulgaris using thirteen microsatellite loci in seven sampling localities from the Mediterranean Sea and one from the Atlantic Ocean. We also used a DNA barcoding approach by COI gene fragment to understand the phylogenetic relationships among the specimens here investigated and the ones whose sequences are available in literature. Our results reveal high levels of allelic richness and moderate heterozygosity in all samples investigated, and a pronounced differentiation of the Atlantic and Sicilian specimens. This latter aspect seems to support the isolation of the biota within the Strait of Messina. A certain degree of differentiation was detected among the other geographic samples within the Mediterranean Sea, which is more compatible with an island model than isolation by distance. The occurrence of null alleles affected more genetic diversity indices than population structure estimations. This study provides new insights about the genetic diversity and structure of O. vulgaris in the area of interest, which can be used as guidelines for a fisheries management perspective.

  6. Testicular maturation of Oligosarcus hepsetus (Cuvier (Actinopterygii, Characidae in a brazilian tropical reservoir

    Directory of Open Access Journals (Sweden)

    R. N. Santos

    Full Text Available Six reproductive classes of male Oligosarcus hepsetus (Cuvier, 1829, a medium-sized carnivorous Characiform species, are described based on macroscopic and histological techniques. A total of 175 individuals were caught monthly between April 2001 and June 2002 in the Lajes Reservoir, Brazil, one of the largest impoundment areas in the state of Rio de Janeiro. The reproductive classes were based upon changes in the testicular morphology and stages of germinative cells, i.e., resting, early maturing, late maturing, mature, partially spent and totally spent. Fish in the resting class showed testes with spermatogonia and spermatocytes along the wall of seminal lobules, while spermatids were present in the lumina of the lobules. During early maturing, active spermatogenesis occurs throughout the testis; in the late maturing and mature classes, the lobules are swollen with sperm that are typical of fish in breeding condition. Spent testes presented seminal lobules with residual spermatozoa, coinciding with decreasing GSI and greatly reduced sperm production. Overall, the testicular morphology and class of maturity development of O. hepsetus in the Lajes reservoir did not differ significantly from those of closely related species in other lentic environments. Lower GSI values in the oligotrophic Lajes reservoir than in other eutrophic natural lakes suggest that this species may be modifying this aspect of its reproductive strategy in response to the artificial environment.

  7. Self-sealing Faults in the Opalinus Clay - Evidence from Field Observations, Hydraulic Testing and Pore water Chemistry

    International Nuclear Information System (INIS)

    Gautschi, Andreas

    2001-01-01

    As part of the Swiss programme for high-level radioactive-waste, the National Cooperative for the Disposal of Radioactive Waste (Nagra) is currently investigating the Jurassic (Aalenian) Opalinus Clay as a potential host formation (Nagra 1988, 1994). The Opalinus Clay consists of indurated dark grey micaceous Clay-stones (shales) that are subdivided into several litho-stratigraphic units. Some of them contain thin sandy lenses, limestone concretions or siderite nodules. The clay mineral content ranges from 40-80 weight per cent (9-29% illite, 3-10% chlorite, 6-20% kaolinite and 4-22% illite/smectite mixed layers in the ratio 70/30). Other minerals are quartz (15-30%), calcite (6-40%), siderite (2-3%), ankerite (0-3%), feldspars (1-7%), pyrite (1-3%) and organic carbon (<1%). The total water content ranges from 4-19% (Mazurek 1999, Nagra 2001). Faults are mainly represented by fault gouge and fault breccias, partly associated with minor veins of calcite. A key question in safety assessment is, whether these faults may represent preferential pathways for radionuclide transport. An extensive hydrogeological data base - part of which derives from strongly tectonized geological environments - suggests that advective transport through faults in the Opalinus Clay at depth > 200 m is insignificant. This conclusion is also supported by independent evidence from clay pore water hydrochemical and isotopic data. The lack of hydrochemical anomalies and the lack of extensive mineral veining suggest that there was also no significant paleo-flow through such faults. These observations can only be reconciled with a strong self-sealing capacity of the faults. Therefore it is concluded, that reactivated existing faults or newly induced fractures will not act as pathways for significant fluid flow at anytime due to self-healing processes. These conclusions are supported by results from laboratory hydro-frac and flow-through tests, and from field-tests in the Mont Terri underground

  8. Dose inseminante utilizada na fertilização artificial de ovócito de piracanjuba (Brycon orbignyanus

    Directory of Open Access Journals (Sweden)

    Viviane de Oliveira Felizardo

    2010-10-01

    Full Text Available A piracanjuba (Brycon orbignyanus Valenciennes, 1849 é uma espécie de peixe migratória, ameaçada de extinção. O objetivo do presente estudo foi determinar a dose inseminante na fertilização artificial de ovócitos de piracanjuba. Para isso, utilizou-se delineamento em blocos casualizados, com quatro tratamentos e três repetições. Três casais de piracanjuba, selecionados dos tanques de reprodutores da Estação Ambiental de Itutinga (EAI - CEMIG, no período de piracema 2006/2007, receberam aplicação de hormônio extrato bruto de hipófise de carpa (EBHC para obtenção dos gametas. Adotaram-se quatro tratamentos diferentes para a fertilização de 0,1 grama de ovócitos: 10µL, 20µL, 30µL e 40µL de sêmen. As amostras foram ativadas com 5 mL de água do próprio tanque e, em seguida, levadas para incubadoras, dotadas de renovação constante de água, à temperatura de 28ºC. Após 8 e 16 horas, analisaram-se as taxas de fertilização (ovos viáveis e de eclosão dos ovos, respectivamente. Os resultados obtidos foram comparados pelo teste de Tukey a 5%. As relações sêmen-ovócitos testadas não alteraram as taxas de fertilização e eclosão (P>0,05. O número de espermatozoides-ovócitos, variando de 10,4 x10(5 a 41,6 x10(5, foi eficiente para obtenção de boas taxas de fertilidade.

  9. Evaluación del cultivo de la dorada ( Brycon moorei sinuensis en jaulas flotantes utilizando cuatro alimentos concentrados.

    Directory of Open Access Journals (Sweden)

    Robinsón Rosado

    2003-12-01

    Full Text Available El presente estudio se inició el 30 de septiembre del2000 con el cultivo de Dorada (Brycon mooreisinuensis en jaulas flotantes en el reservorio de laGranja Piscícola Tamarindo (El Espinal, Colombia,utilizando cuatro alimentos concentrados durante 180días. Se determinó el crecimiento mediante laganancia en longitud, ganancia en peso, tasa decrecimiento específico, sobre-vivencia final, biomasatotal, factor de condición, factor de conversiónalimenticia. Se sembraron 816 juveniles con longitudpromedio de 17.8 cm y peso promedio de 78.9 g,divididos en cuatro tratamientos con densidad desiembra de 25 peces/cm3 y tres réplicas cada uno.Las dietas balanceadas (proteína bruta y la cantidadde energía (Kcal/Kg suministrada fueron: Tratamiento1: 20% y 2637; tratamiento 2: 32% y 3127;tratamiento 3: 28% y 2852; y tratamiento 4: 24% y2751, respectivamente. El diseño experimental fuecompletamente aleatorio y se aplicó la técnica deanálisis de varianza a los datos biométricos yparámetros físico-químicos. Como prueba designificancia se usó la prueba de Tukey-Kramer con95% de confiabilidad. El modelo matemático de VIONBERTALANFY y la transformación de FOR-WALFORDfueron válidos para el ajuste de las curvas decrecimiento en longitud, peso y la relación longitud– peso. Se puede afirmar que la Dorada consumiólas dietas de origen vegetal de igual manera que lasde origen animal, sin embargo la dieta del 28% deproteína bruta (tratamiento 3 muestra los mejoresresultados, sin diferencias significativas entretratamientos (p > 0.05. De acuerdo con la literaturacitada no hay investigaciones que muestren losrequerimientos nutricionales óptimos para laalimentación de esta especie. En todos los trabajosanteriores, la ganancia de peso diaria fue baja, peromejores que las obtenidas en esta investigación.Mientras que el rendimiento en biomasa fue mayorque los reportados para cultivo en tierra, para todoslos tratamientos en este estudio fue muy bajo.

  10. Optimization of sustaining swimming speed of matrinxã Brycon amazonicus: performance and adaptive aspects Otimização da velocidade de nado sustentado em matrinxã Brycon amazonicus: rendimento e aspectos adaptativos

    Directory of Open Access Journals (Sweden)

    Gustavo Arbeláez-Rojas

    2010-01-01

    Full Text Available Deleterious changes in metabolism, growth performance and body composition may be observed if fish are constrained to swimming continuously or intermittently at over-speeds. This study evaluates effects of four water speeds on growth, body composition and hematologic profile of juvenile matrinxã, Brycon amazonicus. Fish (33.3 ± 0.9 g and 13.44 ± 0.1 cm were held for 90 days in five water speeds (0.0 - control, 1.0, 1.5, 2.0 and 2.5 body lengths per second - BLAt swimming speeds ranging on 1.0 and 1.5 BL s–1, in fish growth was 20% higher. Hemoglobin and red blood cells at 1.5 BL s–1 increased 24% and 18% respectively; hematocrit was 17% higher in all exercised fish; protein content of white muscle at 1.0 BL s–1 was 2% higher; lipid deposition in red muscle at 1.0 BL s–1 was 22% higher and water retention 3% lower. Crude energy levels enhanced 10% in all exercised fish; liver water retention was 6% lower at 1.0 BL s–1; liver lipid composition was 29% higher than control and 34% higher than 1.5 BL s–1; liver crude energy increased at 1.0 BL s–1 as compared with control and 2.5 BL s–1. Lipid deposition in ventral muscle was 9% higher at 2.0 BL s–1. Although high lipid deposition of matrinxã has been achieved in moderate swimming speeds, lipids may be the main fuel source to maintain the metabolic demands of exercised matrinxã. The best water flow speed for optimized growth of matrinxã ranged on 1.0 and 1.5 BL s–1.Modificações deletérias no metabolismo, rendimento de crescimento e composição corporal podem ser observadas em peixes forçados à natação contínua ou intermitente sob velocidades excessivas. Neste trabalho, os efeitos de quatro velocidades de água no crescimento, composição corporal e perfil hematológico foram avaliados em matrinxãs juvenis, Brycon amazonicus. Os peixes (33,3 ± 0,9 g e 13,44 ± 0,1 cm foram mantidos durante 90 dias em cinco velocidades de água (0,0 – controle; 1,0; 1,5; 2,0 e 2

  11. LD5o of the bacteria Aeromonas hydrophila to matrinxã, Brycon amazonicus DL5o da bactéria Aeromonas hydrophila para o matrinxã, Brycon amazonicus

    Directory of Open Access Journals (Sweden)

    Sarah Ragonha de Oliveira

    2011-01-01

    Full Text Available In order to determine the lethal dose (96-h LD50 of the bacteria Aeromonas hydrophila to matrinxã, Brycon amazonicus, to be applied in challenge tests, 90 fish (63.23 ± 6.39 g were divided into five treatments, with different bacterial solutions: T1 - Control (0.9% NaCl saline solution; T2 (4 x 10(11 cells/ mL; T3 (5 x 10(11 cells/ mL; T4 (1.36 x 10(12 cells/ mL and T5 (3.06 x 10(12 cells/ mL. Fish were previously anesthetized with benzocaine (60 mg L-1, inoculated in the peritoneal cavity with the bacterial suspensions and then distributed into fifteen 80-L test chambers, where the water variables were monitored and fish mortality was observed. The experiment was randomly designed in three replicates and the 96-h LD50 was estimated according to the trimmed Spearman-Karber method. Water quality variables remained within adequate ranges for fish health and performance. Fish mortality rate increased with the bacterial concentrations of A. hydrophila (T1 = 0%; T2 = 16.66%; T3 = 44.44%; T4 = 72.22% and T5 = 100%, and the first mortalities were observed after 57 h, although the signs of the bacterial infection were already observed 24 h after the inoculation. The results indicate that the 96-h LD50 value of A. hydrophila to matrinxã is 6.66 x 10(11 cells/ mL.Para determinar a dose letal (DL50 96-h da bactéria Aeromonas hydrophila para o matrinxã, Brycon amazonicus, com aplicabilidade para testes de desafio, foram utilizados 90 peixes (63,23 ± 6,39 g, divididos em cinco tratamentos, com diferentes soluções bacterianas: T1 - Controle (solução salina 0,9% NaCl; T2 (4 x 10(11 células/ mL; T3 (5 x 10(11 células/ mL-1; T4 (1,36 x 10(12 células/mL-1 e T5 (3,06 x 10(12 células/ mL-1. Os peixes foram previamente anestesiados com benzocaína (60 mg L-1, inoculados na cavidade peritoneal com as suspensões bacterianas e distribuídos em 15 aquários de vidro de 80 L de capacidade, com aeração constante. O experimento teve duração de 96 h, no

  12. Haematological characteristics of Brazilian Teleosts: III. Parameters of the hybrid tambacu (Piaractus mesopotamicus Holmberg x Colossoma macropomum Cuvier (Osteichthyes, Characidae

    Directory of Open Access Journals (Sweden)

    Marcos Tavares-Dias

    2000-12-01

    Full Text Available Fifty six specimens of the hybrid "tambacu" (Piaractus mesopotamicus Holmberg, 1887 male x Colossoma macropomum Cuvier, 1818 female were collected from fishfarm of Guariba, São Paulo, to evaluate their haematology. Fishes presented 400.0 to 3,100.0 g total weight and 20.0 to 52.0 cm total length. Haemoglobin, haematocrit, mean corpuscular haemoglobin content (MCHC and percentage of defense blood cells including leucocytes and thrombocytes, were studied. Statistical analysis showed positive correlation (P<0.01 between haematocrit, MCHC and haemoglobin rate. Nevertheless, thrombocytes and lymphocytes showed negative correlation (P<0.01.

  13. Studi Aspek Reproduksi Ikan Baung (Mystus nemurus Cuvier Vallenciennes) Di Sungai Bingai Kota Binjai Provinsi Sumatera Utara

    OpenAIRE

    Manurung, Vindy Rilani

    2014-01-01

    VINDY RILANI MANURUNG: The Studied of Fish Reproduction Baung (Mystus nemurus Cuvier Vallenciennes) in Bigai’s River Binjai City North Sumatera Province. Under direction of YUNASFI and DESRITA. The researcher was conducted in the Bingai’s river at Binjai North Sumatera which was held in March to May 2013 at the three different locations points and using sensus metode. The total of baung’s fish (Mystus nemurus C.V) obtained was 29 tails consist of 26 females and 3 males with unbalanced sex ...

  14. Coupled thermo-hydro-mechanical processes around a bentonite buffer embedded in Opalinus Clay - Comparison between measurements and calculations

    Energy Technology Data Exchange (ETDEWEB)

    Goebel, Ingeborg; Alheid, Hans-Joachim [BGR Hannover, Stilleweg 2, D-30655 Hannover (Germany); Jockwer, Norbert [Gesellschaft fuer Anlagen- und Reaktorsicherheit (GRS) mbH, Theodor-Heuss-Str. 4, 38122 Braunschweig (Germany); Mayor, Juan Carlos [ENRESA, Emilio Vargas 7, E-Madrid (Spain); Garcia-Sineriz, Jose Luis [AITEMIN, c/ Alenza, 1 - 28003 Madrid (Spain); Alonso, Eduardo; Munoz, Juan Jorge [International Center for Numerical Methods in Engineering, CIMNE, Edificio C-1, Campus Norte UPC, C/Gran Capitan, s/n, 08034 Barcelona (Spain); Weber, Hans Peter [NAGRA, Hardstrasse 73, CH-5430 Wettingen (Switzerland); Ploetze, Michael [ETHZ, Eidgenoessische Technische Hochschule Zuerich, ETH Zentrum, HG Raemistrasse 101, CH-8092 Zuerich (Switzerland); Klubertanz, Georg [COLENCO Power Engineering Ltd, CPE, Taefern Str. 26, 5405 Baden-Daettwil (Switzerland); Ammon, Christian [Rothpletz, Lienhard, Cie AG, Schifflaendestrasse 35, 5001 Aarau (Switzerland)

    2004-07-01

    The Heater Experiment at the Mont Terri Underground Laboratory consists of an engineered barrier system composed of compacted bentonite blocks around a heater. The bentonite barrier is embedded in Opalinus Clay. The aim of the project is improved understanding of thermo-hydro mechanically (THM) coupled processes. Calculations are performed by 2 Finite-Element programs, CODE-BRIGHT and MHERLIN, the former for the near-field modeling and the latter for the rock modeling. Numerical modeling is carried out during all phases of the project to give input for design tasks such as cooling and dismantling, and to finally produce verified models of the THM coupled engineered barrier system. Results of both programs are discussed in the light of the experimental findings. (authors)

  15. Microbial investigations in Opalinus clay from Mont Terri and in Callovo-Oxfordian argillite from Meuse/Haute-Marne

    International Nuclear Information System (INIS)

    Poulain, S.

    2006-12-01

    The subject of this Ph.D. thesis deals with research achieved in the context of the Axis 2 of the law Bataille voted on December 30, 1991 about the possibility of building a deep geological repository for medium or high activity and long living nuclear waste. Nearby such a site, some microorganisms may influence the mobility of radionuclides coming from the waste canisters. This work consisted in looking for autochthonous microorganisms in the Opalinus clay formation from Mont Terri (Switzerland) and in the Callovo-Oxfordian argillite from Meuse/Haute-Marne (France). Microbial Investigations in these unknown unperturbed environments suggested very low microbial densities in the clayey sediments. However, new bacterial species could be isolated from those samples. In addition, a part of the allochthonous population, which has been introduced by air and human activity, could be identified in the Meuse/Haute-Marne underground research laboratory. (author)

  16. Far Field Sorption Data Bases for Performance Assessment of a High-Level Radioactive Waste Repository in an Undisturbed Opalinus Clay Host Rock

    International Nuclear Information System (INIS)

    Bradburry, M.; Baeyens, B.

    2003-08-01

    An Opalinus Clay formation in the Zuercher Weinland is under consideration by Nagra as a potential location for a high-level and long-Iived intermediate-level radioactive waste repository. Performance assessment studies will be performed for this site and the purpose of this report is to describe the procedures used to develop sorption data bases appropriate for an undisturbed Opalinus Clay host rock which are required for such safety analysis calculations. In tight, low water content argillaceous rock formations such as Opalinus Clay, there is uncertainty concerning the in situ pH/P CO 2 . In order to take this intrinsic uncertainty into account porewater chemistries were calculated for a reference case, pH = 7.24, and for two other pH values, 6.3 and 7.8. Sorption data bases are given for the three cases. The basis for the sorption data bases is 'in-house' sorption measurements for Cs(I), Sr(II), Ni(II), Eu(III), Sn(IV), Se(IV), Th(IV) and I(-I) carried out on Opalinus Clay samples from Mont Terri (Canton Jura) since at the time the experiments were performed no core samples from the Benken borehole (Zuercher Weinland) were available. The Opalinus Clay at Mont Terri and Benken are part of the same geological formation . Despite having directly measured data for the above key radionuclides, some of the required distribution ratios (Rd) used to generate the sorption data bases still came from the open literature. An important part of this report is concerned with describing the procedures whereby these selected literature Rd values were modified so as to apply to the Benken Opalinus Clay mineralogy and groundwater chemistries calculated at the three pH values given above. The resulting Rd values were then further modified using so-called Lab→Field transfer factors to produce sorption values which were appropriate to the in situ bulk rock for the selected range of water chemistry conditions. Finally, it is important to have some appreciation of the uncertainties

  17. Far Field Sorption Data Bases for Performance Assessment of a High-Level Radioactive Waste Repository in an Undisturbed Opalinus Clay Host Rock

    Energy Technology Data Exchange (ETDEWEB)

    Bradburry, M.; Baeyens, B

    2003-08-01

    An Opalinus Clay formation in the Zuercher Weinland is under consideration by Nagra as a potential location for a high-level and long-Iived intermediate-level radioactive waste repository. Performance assessment studies will be performed for this site and the purpose of this report is to describe the procedures used to develop sorption data bases appropriate for an undisturbed Opalinus Clay host rock which are required for such safety analysis calculations. In tight, low water content argillaceous rock formations such as Opalinus Clay, there is uncertainty concerning the in situ pH/P{sub CO{sub 2}}. In order to take this intrinsic uncertainty into account porewater chemistries were calculated for a reference case, pH = 7.24, and for two other pH values, 6.3 and 7.8. Sorption data bases are given for the three cases. The basis for the sorption data bases is 'in-house' sorption measurements for Cs(I), Sr(II), Ni(II), Eu(III), Sn(IV), Se(IV), Th(IV) and I(-I) carried out on Opalinus Clay samples from Mont Terri (Canton Jura) since at the time the experiments were performed no core samples from the Benken borehole (Zuercher Weinland) were available. The Opalinus Clay at Mont Terri and Benken are part of the same geological formation . Despite having directly measured data for the above key radionuclides, some of the required distribution ratios (Rd) used to generate the sorption data bases still came from the open literature. An important part of this report is concerned with describing the procedures whereby these selected literature Rd values were modified so as to apply to the Benken Opalinus Clay mineralogy and groundwater chemistries calculated at the three pH values given above. The resulting Rd values were then further modified using so-called Lab{yields}Field transfer factors to produce sorption values which were appropriate to the in situ bulk rock for the selected range of water chemistry conditions. Finally, it is important to have some

  18. Ecología trófica de la Sabaleta Brycon henni (Pisces: Characidae en el río Portugal de Piedras, Alto Cauca, Colombia

    Directory of Open Access Journals (Sweden)

    Alvaro Botero-Botero

    2011-04-01

    Full Text Available Objetivo. Estudiar la ecología trófica de la sabaleta (Brycon henni en el río Portugal de Piedras, cordillera Oriental, departamento del Valle del Cauca. Materiales y métodos. Desde octubre de 2008 hasta junio de 2009 se realizaron pescas exploratorias y se determinaron parámetros físico y químicos del hábitat. Los ejemplares capturados fueron eviscerados y el contenido estomacal fue determinado hasta el mínimo taxón posible. Resultados. La especie presenta una dieta generalista que incluye 35 categorías alimenticias, con tendencia al consumo de larvas y ninfas de insectos acuáticos entre los cuales se destacan tricópteros, dípteros y odonatos; también, consume organismos alóctonos al cauce como hormigas (Hymenoptera, escarabajos (Coleoptera y material vegetal: frutos, semillas y hojas. La relación longitud intestino (LI vs. longitud estándar (LS indican que la especie presenta características propias de una especie carnívora (LI = -13.8728 + 1.02377*LS, r= 0.35, n= 22, a su vez, el peso total (PT depende directamente de la longitud total (LT y LS del pez (PT = -49.308 + 0.609962*LT; r= 0.92 n=30; PT = -41.6011 + 0.672529*LS; r= 0.89, n=30, respectivamente. Conclusiones. La sabaleta (Brycon henni presentó caracteristicas de una especie carnivora.

  19. Characterisation of gas transport properties of the Opalinus clay, a potential host rock formation for radioactive waste disposal

    International Nuclear Information System (INIS)

    Marschall, P.; Horseman, S.; Gimmi, T.

    2005-01-01

    The Opalinus Clay in Northern Switzerland has been identified as a potential host rock formation for the disposal of radioactive waste. Comprehensive understanding of gas transport processes through this low-permeability formation forms a key issue in the assessment of repository performance. Field investigations and laboratory experiments suggest an intrinsic permeability of the Opalinus Clay in the order of 10 -20 to 10 -21 m 2 and a moderate anisotropy ratio ≤ 10. Porosity depends on clay content and burial depth; values of ∼ 0.12 are reported for the region of interest. Porosimetry indicates that about 10-30% of voids can be classed as macro-pores, corresponding to an equivalent pore radius > 25 nm. The determined entry pressures are in the range of 0.4-10 MPa and exhibit a marked dependence on intrinsic permeability. Both in situ gas tests and gas permeameter tests on drill-cores demonstrate that gas transport through the rock is accompanied by pore water displacement, suggesting that classical flow concepts of immiscible displacement in porous media can be applied when the gas entry pressure (i.e. capillary threshold pressure) is less than the minimum principal stress acting within the rock. Essentially, the pore space accessible to gas flow is restricted to the network of connected macro-pores, which implies a very low degree of desaturation of the rock during the gas imbibition process. At elevated gas pressures (i.e. when gas pressure approaches the level of total stress that acts on the rock body), evidence was seen for dilatancy controlled gas transport mechanisms. Further field experiments were aimed at creating extended tensile fractures with high fracture transmissivity (hydro- or gas-fractures). The test results lead to the conclusion that gas fracturing can be largely ruled out as a risk for post-closure repository performance. (authors)

  20. Concrete - Opalinus clay interaction: in-situ experiment and technique for coring undisturbed interfaces

    International Nuclear Information System (INIS)

    Maeder, U.; Dolder, F.; Jenni, A.; Schwyn, B.; Frieg, B.; Eul, A.

    2012-01-01

    Document available in extended abstract form only. Designs for deep geologic disposal of radioactive waste foresee cementitious materials as structural elements, backfill or waste matrix. Interactions near interfaces are driven by chemical gradients in pore water and resultant diffusive transport, and are predicted to lead to mineralogical alterations in the barrier system, which in turn influences properties like swelling pressure, permeability, or specific retention in case of clay materials. Reactive transport modelling predictions and laboratory and in situ studies revealed significant alteration in both cement and clay-stone. An increase in porosity in the cement close to the interface, and clogging in the clay-stone adjacent to the interface is commonly predicted and observed. The Cement-Clay Interaction (CI) Experiment at the Mont Terri Underground Laboratory (St. Ursanne, Switzerland) aims at demonstrating some of the processes at interfaces to be expected at a realistic spatial scale and under saturated conditions. A duration of 20 years is foreseen during which reaction progress should become measurable and thus comparable to laboratory experiments and modelling predictions. Companion studies address cement hydration, and develop new high-resolution techniques for phase identification using μ-X-ray diffraction at the Paul Scherrer Institut. The field experiment at Mont Terri comprises two vertical boreholes (384 mm diameter, up to 9 m length) in Opalinus Clay (OPA) filled with layers of three different concretes and bentonite. The concrete formulations are based on three different binders: Portland cement (OPC), ESDRED cement designed for repository applications (40% of cement substituted by silica fume), and low alkali cement (LAC, containing slag and nano-silica). The characterisation of the three concrete-OPA interfaces after 2 years of alteration are presented in a companion contribution (Jenni et al.). A key issue is the repeat recovery of

  1. Project Opalinus clay Zuercher Weinland of Nagra. Evaluation of the geo-scientific data base and of the construction engineering aspects

    International Nuclear Information System (INIS)

    2005-02-01

    In this report the Commission for Nuclear Waste Management (KNE) assesses the geological and engineering aspects of the project Opalinus Clay, in which Nagra demonstrates the postclosure safety of geological disposal of spent fuel (SF), vitrified high-level wastes (HLW) and intermediate-level wastes (ILW) in a repository in the Opalinus Clay of the Zuercher Weinland in northern Switzerland. After in-depth examination of the geological database, KNE concludes that the demonstration of a suitable geological site for final disposal of SF, HLW and ILW in the Opalinus Clay of the Zuercher Weinland has been achieved. The geological assumptions Nagra uses for the assessment of long-term safety are based on data that have been carefully collected and interpreted. KNE acknowledges that Nagra interpreted the geological data correctly and adequately using state-of-the-art techniques. In case of lacking information, Nagra has used conservative or worst-case assumptions. The information documented by Nagra represents a good synthesis of field, laboratory and literature data. The tectonic situation of the Zuercher Weinland was examined in great details by Nagra. In the centre of the investigated region, where the Opalinus Clay occurs at 600 to 750 meters depth, the 3D-seismic data confirm its undisturbed stratification in an area of about 15 km 2 . Analysis and interpretation of the available information on the geological evolution provides no indication that erosion would expose the confining units above the Opalinus Clay within the next million years. The Opalinus Clay in the Zuercher Weinland is quite homogeneous and about 110 m thick. The properties of this rock are examined and found to be favourable for a repository. The dominance of the fine grain size and the high clay content indicate a very low hydraulic conductivity suitable for the isolation of radioactive wastes. Pore water extracted from drill-core samples is saline and has remained trapped for millions of years

  2. Growth and maximum size of tiger sharks (Galeocerdo cuvier) in Hawaii.

    Science.gov (United States)

    Meyer, Carl G; O'Malley, Joseph M; Papastamatiou, Yannis P; Dale, Jonathan J; Hutchinson, Melanie R; Anderson, James M; Royer, Mark A; Holland, Kim N

    2014-01-01

    Tiger sharks (Galecerdo cuvier) are apex predators characterized by their broad diet, large size and rapid growth. Tiger shark maximum size is typically between 380 & 450 cm Total Length (TL), with a few individuals reaching 550 cm TL, but the maximum size of tiger sharks in Hawaii waters remains uncertain. A previous study suggested tiger sharks grow rather slowly in Hawaii compared to other regions, but this may have been an artifact of the method used to estimate growth (unvalidated vertebral ring counts) compounded by small sample size and narrow size range. Since 1993, the University of Hawaii has conducted a research program aimed at elucidating tiger shark biology, and to date 420 tiger sharks have been tagged and 50 recaptured. All recaptures were from Hawaii except a single shark recaptured off Isla Jacques Cousteau (24°13'17″N 109°52'14″W), in the southern Gulf of California (minimum distance between tag and recapture sites  =  approximately 5,000 km), after 366 days at liberty (DAL). We used these empirical mark-recapture data to estimate growth rates and maximum size for tiger sharks in Hawaii. We found that tiger sharks in Hawaii grow twice as fast as previously thought, on average reaching 340 cm TL by age 5, and attaining a maximum size of 403 cm TL. Our model indicates the fastest growing individuals attain 400 cm TL by age 5, and the largest reach a maximum size of 444 cm TL. The largest shark captured during our study was 464 cm TL but individuals >450 cm TL were extremely rare (0.005% of sharks captured). We conclude that tiger shark growth rates and maximum sizes in Hawaii are generally consistent with those in other regions, and hypothesize that a broad diet may help them to achieve this rapid growth by maximizing prey consumption rates.

  3. Reef-fidelity and migration of tiger sharks, Galeocerdo cuvier, across the coral sea

    KAUST Repository

    Werry, Jonathan M.

    2014-01-08

    Knowledge of the habitat use and migration patterns of large sharks is important for assessing the effectiveness of large predator Marine Protected Areas (MPAs), vulnerability to fisheries and environmental influences, and management of shark-human interactions. Here we compare movement, reef-fidelity, and ocean migration for tiger sharks, Galeocerdo cuvier, across the Coral Sea, with an emphasis on New Caledonia. Thirty-three tiger sharks (1.54 to 3.9 m total length) were tagged with passive acoustic transmitters and their localised movements monitored on receiver arrays in New Caledonia, the Chesterfield and Lord Howe Islands in the Coral Sea, and the east coast of Queensland, Australia. Satellite tags were also used to determine habitat use and movements among habitats across the Coral Sea. Sub-adults and one male adult tiger shark displayed year-round residency in the Chesterfields with two females tagged in the Chesterfields and detected on the Great Barrier Reef, Australia, after 591 and 842 days respectively. In coastal barrier reefs, tiger sharks were transient at acoustic arrays and each individual demonstrated a unique pattern of occurrence. From 2009 to 2013, fourteen sharks with satellite and acoustic tags undertook wide-ranging movements up to 1114 km across the Coral Sea with eight detected back on acoustic arrays up to 405 days after being tagged. Tiger sharks dove 1136 m and utilised three-dimensional activity spaces averaged at 2360 km3. The Chesterfield Islands appear to be important habitat for sub-adults and adult male tiger sharks. Management strategies need to consider the wide-ranging movements of large (sub-adult and adult) male and female tiger sharks at the individual level, whereas fidelity to specific coastal reefs may be consistent across groups of individuals. Coastal barrier reef MPAs, however, only afford brief protection for large tiger sharks, therefore determining the importance of other oceanic Coral Sea reefs should be a

  4. Residency and movement patterns of an apex predatory shark (Galeocerdo cuvier at the Galapagos Marine Reserve.

    Directory of Open Access Journals (Sweden)

    David Acuña-Marrero

    Full Text Available The potential effectiveness of marine protected areas (MPAs as a conservation tool for large sharks has been questioned due to the limited spatial extent of most MPAs in contrast to the complex life history and high mobility of many sharks. Here we evaluated the movement dynamics of a highly migratory apex predatory shark (tiger shark Galeocerdo cuvier at the Galapagos Marine Reserve (GMR. Using data from satellite tracking passive acoustic telemetry, and stereo baited remote underwater video, we estimated residency, activity spaces, site fidelity, distributional abundances and migration patterns from the GMR and in relation to nesting beaches of green sea turtles (Chelonia mydas, a seasonally abundant and predictable prey source for large tiger sharks. Tiger sharks exhibited a high degree of philopatry, with 93% of the total satellite-tracked time across all individuals occurring within the GMR. Large sharks (> 200 cm TL concentrated their movements in front of the two most important green sea turtle-nesting beaches in the GMR, visiting them on a daily basis during nocturnal hours. In contrast, small sharks (< 200 cm TL rarely visited turtle-nesting areas and displayed diurnal presence at a third location where only immature sharks were found. Small and some large individuals remained in the three study areas even outside of the turtle-nesting season. Only two sharks were satellite-tracked outside of the GMR, and following long-distance migrations, both individuals returned to turtle-nesting beaches at the subsequent turtle-nesting season. The spatial patterns of residency and site fidelity of tiger sharks suggest that the presence of a predictable source of prey and suitable habitats might reduce the spatial extent of this large shark that is highly migratory in other parts of its range. This highly philopatric behaviour enhances the potential effectiveness of the GMR for their protection.

  5. Reef-fidelity and migration of tiger sharks, Galeocerdo cuvier, across the coral sea

    KAUST Repository

    Werry, Jonathan M.; Planes, Serge; Berumen, Michael L.; Lee, Kate A.; Braun, Camrin D.; Clua, Eric

    2014-01-01

    Knowledge of the habitat use and migration patterns of large sharks is important for assessing the effectiveness of large predator Marine Protected Areas (MPAs), vulnerability to fisheries and environmental influences, and management of shark-human interactions. Here we compare movement, reef-fidelity, and ocean migration for tiger sharks, Galeocerdo cuvier, across the Coral Sea, with an emphasis on New Caledonia. Thirty-three tiger sharks (1.54 to 3.9 m total length) were tagged with passive acoustic transmitters and their localised movements monitored on receiver arrays in New Caledonia, the Chesterfield and Lord Howe Islands in the Coral Sea, and the east coast of Queensland, Australia. Satellite tags were also used to determine habitat use and movements among habitats across the Coral Sea. Sub-adults and one male adult tiger shark displayed year-round residency in the Chesterfields with two females tagged in the Chesterfields and detected on the Great Barrier Reef, Australia, after 591 and 842 days respectively. In coastal barrier reefs, tiger sharks were transient at acoustic arrays and each individual demonstrated a unique pattern of occurrence. From 2009 to 2013, fourteen sharks with satellite and acoustic tags undertook wide-ranging movements up to 1114 km across the Coral Sea with eight detected back on acoustic arrays up to 405 days after being tagged. Tiger sharks dove 1136 m and utilised three-dimensional activity spaces averaged at 2360 km3. The Chesterfield Islands appear to be important habitat for sub-adults and adult male tiger sharks. Management strategies need to consider the wide-ranging movements of large (sub-adult and adult) male and female tiger sharks at the individual level, whereas fidelity to specific coastal reefs may be consistent across groups of individuals. Coastal barrier reef MPAs, however, only afford brief protection for large tiger sharks, therefore determining the importance of other oceanic Coral Sea reefs should be a

  6. Better Fitness in Captive Cuvier's Gazelle despite Inbreeding Increase: Evidence of Purging?

    Directory of Open Access Journals (Sweden)

    Eulalia Moreno

    Full Text Available Captive breeding of endangered species often aims at preserving genetic diversity and to avoid the harmful effects of inbreeding. However, deleterious alleles causing inbreeding depression can be purged when inbreeding persists over several generations. Despite its great importance both for evolutionary biology and for captive breeding programmes, few studies have addressed whether and to which extent purging may occur. Here we undertake a longitudinal study with the largest captive population of Cuvier's gazelle managed under a European Endangered Species Programme since 1975. Previous results in this population have shown that highly inbred mothers tend to produce more daughters, and this fact was used in 2006 to reach a more appropriate sex-ratio in this polygynous species by changing the pairing strategy (i.e., pairing some inbred females instead of keeping them as surplus individuals in the population. Here, by using studbook data we explore whether purging has occurred in the population by investigating whether after the change in pairing strategy a inbreeding and homozygosity increased at the population level, b fitness (survival increased, and c the relationship between inbreeding and juvenile survival, was positive. Consistent with the existence of purging, we found an increase in inbreeding coefficients, homozygosity and juvenile survival. In addition, we showed that in the course of the breeding programme the relationship between inbreeding and juvenile survival was not uniform but rather changed over time: it was negative in the early years, flat in the middle years and positive after the change in pairing strategy. We highlight that by allowing inbred individuals to mate in captive stocks we may favour sex-ratio bias towards females, a desirable managing strategy to reduce the surplus of males that force most zoos to use ethical culling and euthanizing management tools. We discuss these possibilities but also acknowledge that many

  7. Intraspecific variation in vertical habitat use by tiger sharks (Galeocerdo cuvier) in the western North Atlantic.

    Science.gov (United States)

    Vaudo, Jeremy J; Wetherbee, Bradley M; Harvey, Guy; Nemeth, Richard S; Aming, Choy; Burnie, Neil; Howey-Jordan, Lucy A; Shivji, Mahmood S

    2014-05-01

    Tiger sharks (Galeocerdo cuvier) are a wide ranging, potentially keystone predator species that display a variety of horizontal movement patterns, making use of coastal and pelagic waters. Far less, however, is known about their vertical movements and use of the water column. We used pop-up satellite archival tags with two data sampling rates (high rate and standard rate tags) to investigate the vertical habitat use and diving behavior of tiger sharks tagged on the Puerto Rico-Virgin Islands platform and off Bermuda between 2008 and 2009. Useable data were received from nine of 14 sharks tagged, tracked over a total of 529 days. Sharks spent the majority of their time making yo-yo dives within the upper 50 m of the water column and considerable time within the upper 5 m of the water column. As a result, sharks typically occupied a narrow daily temperature range (∼2°C). Dives to greater than 200 m were common, and all sharks made dives to at least 250 m, with one shark reaching a depth of 828 m. Despite some similarities among individuals, a great deal of intraspecific variability in vertical habit use was observed. Four distinct depth distributions that were not related to tagging location, horizontal movements, sex, or size were detected. In addition, similar depth distributions did not necessitate similar dive patterns among sharks. Recognition of intraspecific variability in habitat use of top predators can be crucial for effective management of these species and for understanding their influence on ecosystem dynamics.

  8. Intraspecific variation in vertical habitat use by tiger sharks (Galeocerdo cuvier) in the western North Atlantic

    Science.gov (United States)

    Vaudo, Jeremy J; Wetherbee, Bradley M; Harvey, Guy; Nemeth, Richard S; Aming, Choy; Burnie, Neil; Howey-Jordan, Lucy A; Shivji, Mahmood S

    2014-01-01

    Tiger sharks (Galeocerdo cuvier) are a wide ranging, potentially keystone predator species that display a variety of horizontal movement patterns, making use of coastal and pelagic waters. Far less, however, is known about their vertical movements and use of the water column. We used pop-up satellite archival tags with two data sampling rates (high rate and standard rate tags) to investigate the vertical habitat use and diving behavior of tiger sharks tagged on the Puerto Rico–Virgin Islands platform and off Bermuda between 2008 and 2009. Useable data were received from nine of 14 sharks tagged, tracked over a total of 529 days. Sharks spent the majority of their time making yo-yo dives within the upper 50 m of the water column and considerable time within the upper 5 m of the water column. As a result, sharks typically occupied a narrow daily temperature range (∼2°C). Dives to greater than 200 m were common, and all sharks made dives to at least 250 m, with one shark reaching a depth of 828 m. Despite some similarities among individuals, a great deal of intraspecific variability in vertical habit use was observed. Four distinct depth distributions that were not related to tagging location, horizontal movements, sex, or size were detected. In addition, similar depth distributions did not necessitate similar dive patterns among sharks. Recognition of intraspecific variability in habitat use of top predators can be crucial for effective management of these species and for understanding their influence on ecosystem dynamics. PMID:24963376

  9. Reef-fidelity and migration of tiger sharks, Galeocerdo cuvier, across the Coral Sea.

    Science.gov (United States)

    Werry, Jonathan M; Planes, Serge; Berumen, Michael L; Lee, Kate A; Braun, Camrin D; Clua, Eric

    2014-01-01

    Knowledge of the habitat use and migration patterns of large sharks is important for assessing the effectiveness of large predator Marine Protected Areas (MPAs), vulnerability to fisheries and environmental influences, and management of shark-human interactions. Here we compare movement, reef-fidelity, and ocean migration for tiger sharks, Galeocerdo cuvier, across the Coral Sea, with an emphasis on New Caledonia. Thirty-three tiger sharks (1.54 to 3.9 m total length) were tagged with passive acoustic transmitters and their localised movements monitored on receiver arrays in New Caledonia, the Chesterfield and Lord Howe Islands in the Coral Sea, and the east coast of Queensland, Australia. Satellite tags were also used to determine habitat use and movements among habitats across the Coral Sea. Sub-adults and one male adult tiger shark displayed year-round residency in the Chesterfields with two females tagged in the Chesterfields and detected on the Great Barrier Reef, Australia, after 591 and 842 days respectively. In coastal barrier reefs, tiger sharks were transient at acoustic arrays and each individual demonstrated a unique pattern of occurrence. From 2009 to 2013, fourteen sharks with satellite and acoustic tags undertook wide-ranging movements up to 1114 km across the Coral Sea with eight detected back on acoustic arrays up to 405 days after being tagged. Tiger sharks dove 1136 m and utilised three-dimensional activity spaces averaged at 2360 km³. The Chesterfield Islands appear to be important habitat for sub-adults and adult male tiger sharks. Management strategies need to consider the wide-ranging movements of large (sub-adult and adult) male and female tiger sharks at the individual level, whereas fidelity to specific coastal reefs may be consistent across groups of individuals. Coastal barrier reef MPAs, however, only afford brief protection for large tiger sharks, therefore determining the importance of other oceanic Coral Sea reefs should be a

  10. Influence of food restriction on the reproduction and larval performance of matrinxã, Brycon amazonicus (Spix and Agassiz, 1829

    Directory of Open Access Journals (Sweden)

    ACS. Camargo

    Full Text Available This work evaluated the effect of food restriction and refeeding of matrinxã females, Brycon amazonicus, on their reproductive performance and on the growth and survival of the progeny. Broodstocks were distributed in 8 earthen tanks (15 fish/tank and fish from 4 tanks were fed daily (G1 while fish from the other 4 tanks were fed for 3 days and not fed for 2 days (G2 during 6 months prior to artificial spawning. Among the induced females, 57% in G1 group and 45% in G2 group spawned and the mean egg weights were 208.1 g (G1 and 131.6 g (G2. Oocytes of G2 fish were smaller (1.017 ± 0.003 mm than oocytes of G1 fish (1.048 ± 0.002 mm. Fertilization (71.91 ± 12.6% and 61.18 ± 13.7% and hatching (61.28 ± 33.9% and 67.50 ± 23.4% rates did not differ between G1 and G2 fish. Larvae were collected at hatching and at 24, 48 and 72 hours of incubation and fixed for growth measurement. After incubation, fry were transferred to aquaria and sampled 1, 5, 9 and 15 days later. G1 and G2 larvae had similar weight (1.51 ± 0.15 and 1.46 ± 0.07 mg but the G2 length was significantly higher (6.26 ± 0.13 and 6.74 ± 0.14 mm. By the ninth day of rearing, G2 fry had higher weight (13.6 ± 0.26 and 18.9 ± 0.07 mg and length (11.8 ± 0.09 and 14.5 ± 0.04 mm but by the fifteenth day, G1 fry had higher weight (90.2 ± 1.19 and 68.6 ± 0.77 mg and length (18.8 ± 0.16 and 18.5 ± 0.04 mm than G2 fry. By the ninth day of rearing, when fry are recommended to be transferred to outdoor tanks, G2 fry were larger and after 15 days, fry produced by restricted-fed females showed higher survival. The survival rate of G2 progeny by the fifteenth day was significantly higher (24.7 ± 2.07% than that of G1 progeny (19.2 ± 1.91%. The ration restriction (35% reduction imposed on matrinxã broodstock during 6 months prior to spawning reduced the number of spawned females and the egg amount, but it did not affect fertilization and hatching rates. Otherwise restricted

  11. Influence of food restriction on the reproduction and larval performance of matrinxã, Brycon amazonicus (Spix and Agassiz, 1829).

    Science.gov (United States)

    Camargo, A C S; Urbinati, E C

    2008-11-01

    This work evaluated the effect of food restriction and refeeding of matrinxã females, Brycon amazonicus, on their reproductive performance and on the growth and survival of the progeny. Broodstocks were distributed in 8 earthen tanks (15 fish/tank) and fish from 4 tanks were fed daily (G1) while fish from the other 4 tanks were fed for 3 days and not fed for 2 days (G2) during 6 months prior to artificial spawning. Among the induced females, 57% in G1 group and 45% in G2 group spawned and the mean egg weights were 208.1 g (G1) and 131.6 g (G2). Oocytes of G2 fish were smaller (1.017 +/- 0.003 mm) than oocytes of G1 fish (1.048 +/- 0.002 mm). Fertilization (71.91 +/- 12.6% and 61.18 +/- 13.7%) and hatching (61.28 +/- 33.9% and 67.50 +/- 23.4%) rates did not differ between G1 and G2 fish. Larvae were collected at hatching and at 24, 48 and 72 hours of incubation and fixed for growth measurement. After incubation, fry were transferred to aquaria and sampled 1, 5, 9 and 15 days later. G1 and G2 larvae had similar weight (1.51 +/- 0.15 and 1.46 +/- 0.07 mg) but the G2 length was significantly higher (6.26 +/- 0.13 and 6.74 +/- 0.14 mm). By the ninth day of rearing, G2 fry had higher weight (13.6 +/- 0.26 and 18.9 +/- 0.07 mg) and length (11.8 +/- 0.09 and 14.5 +/- 0.04 mm) but by the fifteenth day, G1 fry had higher weight (90.2 +/- 1.19 and 68.6 +/- 0.77 mg) and length (18.8 +/- 0.16 and 18.5 +/- 0.04 mm) than G2 fry. By the ninth day of rearing, when fry are recommended to be transferred to outdoor tanks, G2 fry were larger and after 15 days, fry produced by restricted-fed females showed higher survival. The survival rate of G2 progeny by the fifteenth day was significantly higher (24.7 +/- 2.07%) than that of G1 progeny (19.2 +/- 1.91%). The ration restriction (35% reduction) imposed on matrinxã broodstock during 6 months prior to spawning reduced the number of spawned females and the egg amount, but it did not affect fertilization and hatching rates. Otherwise

  12. Mont Terri Project - Ventilation experiment in Opalinus Clay for the disposal of radioactive waste in underground repositories

    Energy Technology Data Exchange (ETDEWEB)

    Mayor, J. C. [Empresa Nacional de Residuos Radioactivos SA (ENRESA), Madrid (Spain); Garcia-Sineriz, J. [Asociacion para la Investigacion y Desarollo Industrial de los Recursos Naturales (AITEMIN), Madrid (Spain); Velasco, M. [DM Iberia SA, Madrid (Spain); Gomez-Hernandez, J. [Ingenieria Hidraulica y Medio Ambiente, Escuela de Ingenieros de Caminos (UPV), Valencia (Spain); Lloret, A.; Matray, J.-M. [IRSN/DEI/SARG/LETS, Fontenay-aux-Roses (France); Coste, F. [Aradis ESG, Sevres Cedex (France); Giraud, A. [LAEGO-ENSG, Vandoeuvre les Nancy (France); Rothfuchs, T. [Gesellschaft fuer Anlagen und Reaktorsicherheit mbH (GRS), Braunschweig (Germany); Marschall, P. [National Cooperative for the Disposal of Radioactive Waste (Nagra), Wettingen (Switzerland); Roesli, U. [Solexperts AG, Moenchaltorf (Switzerland); Mayer, G. [Colenco Power Engineering Ltd, Baden (Switzerland)

    2007-07-01

    The ventilation of the underground drifts during the construction and operation of a radioactive waste repository could produce the partial desaturation of the rock around the drifts, modifying its thermo-hydro-mechanical properties, especially in clayey rocks. This change of rock properties may have an impact on the design of the repositories (drifts spacing and repository size), which depends on the thermal load that the clay barrier and the rock can accept. To evaluate 'in situ' and better understand the desaturation process of a hard clay formation, the Ventilation Experiment (VE) has been carried out at the Mont Terri underground laboratory (Switzerland), generating a flow of dry air during several months along a section of a microtunnel. Specifically, the VE test has been performed, under practically isothermal conditions (T {approx_equal} 15-16 {sup o}C), in a 10 m long section of a non-lined horizontal microtunnel (diameter = 1.3 m), excavated in 1999 in the shaly facies of the Opalinus Clay of Mont Terri. The microtunnel is oriented perpendicular to the bedding strike direction of the rock (mean value of the bedding dip {approx_equal} 25{sup o}). The VE experiment real data and its modelling have shown that the desaturation of clayey rocks of low hydraulic conductivity (K < 10{sup -12} m/s) due to ventilation is very small. Under real repository conditions, the thermal and hydro-mechanical rock characteristics will not be practically affected by the ventilation. Specifically, the monitoring of the VE test (mainly the hygrometer data, confirmed also by the geoelectrical measurements) indicates that, after about 5 months of ventilation with almost dry air, the rock relative humidity (and then the degree of saturation) was less than 95% only in a ring of thickness less than 40 cm. Nevertheless, a suction state (subatmospheric liquid pressures) developed up to a distance of about 2 m, but it should be kept in mind that a clayey rock such as the

  13. Mont Terri Project - Ventilation experiment in Opalinus Clay for the disposal of radioactive waste in underground repositories

    International Nuclear Information System (INIS)

    Mayor, J. C.; Garcia-Sineriz, J.; Velasco, M.; Gomez-Hernandez, J.; Lloret, A.; Matray, J.-M.; Coste, F.; Giraud, A.; Rothfuchs, T.; Marschall, P.; Roesli, U.; Mayer, G.

    2007-01-01

    The ventilation of the underground drifts during the construction and operation of a radioactive waste repository could produce the partial desaturation of the rock around the drifts, modifying its thermo-hydro-mechanical properties, especially in clayey rocks. This change of rock properties may have an impact on the design of the repositories (drifts spacing and repository size), which depends on the thermal load that the clay barrier and the rock can accept. To evaluate 'in situ' and better understand the desaturation process of a hard clay formation, the Ventilation Experiment (VE) has been carried out at the Mont Terri underground laboratory (Switzerland), generating a flow of dry air during several months along a section of a microtunnel. Specifically, the VE test has been performed, under practically isothermal conditions (T ≅ 15-16 o C), in a 10 m long section of a non-lined horizontal microtunnel (diameter = 1.3 m), excavated in 1999 in the shaly facies of the Opalinus Clay of Mont Terri. The microtunnel is oriented perpendicular to the bedding strike direction of the rock (mean value of the bedding dip ≅ 25 o ). The VE experiment real data and its modelling have shown that the desaturation of clayey rocks of low hydraulic conductivity (K -12 m/s) due to ventilation is very small. Under real repository conditions, the thermal and hydro-mechanical rock characteristics will not be practically affected by the ventilation. Specifically, the monitoring of the VE test (mainly the hygrometer data, confirmed also by the geoelectrical measurements) indicates that, after about 5 months of ventilation with almost dry air, the rock relative humidity (and then the degree of saturation) was less than 95% only in a ring of thickness less than 40 cm. Nevertheless, a suction state (subatmospheric liquid pressures) developed up to a distance of about 2 m, but it should be kept in mind that a clayey rock such as the Opalinus Clay is quasi-saturated for suction values up

  14. Fracture transmissivity as a function of normal and shear stress: first results in Opalinus Clay

    International Nuclear Information System (INIS)

    Cuss, R.J.; Milodowski, A.; Noy, D.J.; Harrington, J.F.

    2010-01-01

    Document available in extended abstract form only. Rock-mass failure around openings is usually observed in the form of a highly complex fracture network (EDZ), which is heterogeneous in distribution around a circular tunnel opening because of the heterogeneous stress distribution. The orientation of stress with respect to the fracture network is known to be important. The complex heterogeneous stress trajectory and heterogeneous fracture network results in a broad range of stresses and stress directions acting on the open fracture network. During the open stage of a repository, stress will slowly alter as shear movements occur along the fractures, as well as other time-dependent phenomena. As the repository is back filled, the stress field is further altered as the backfill settles and changes volume because of re-saturation. Therefore, a complex and wide ranging stress regime and stress history will result. In a purely mechanical sense, fracture transmissivity is a function of normal stress, shear stress, and fracture aperture. The Selfrac test from Mont Terri showed the change in transmissivity with effective normal stress. This work showed that fracture transmissivity decreased with increasing normal load and that an effective normal stress of 2.5 MPa is sufficient to yield a transmissivity similar to that seen in intact Opalinus clay (OPA). Therefore fracture closure because of normal stresses has been proven to be a quite efficient mechanism in OPA. A new shear rig was designed to investigate the detail of fracture transmissivity in OPA. The experimental configuration uses two prepared blocks that are 60 x 60 mm in size and approximately 20 mm thick. The first test sample had machine ground surfaces in contact with each other, with pore fluid being delivered through the centre of the top block directly to the fracture surface. The experimental programme included two distinct stages. In the first normal load was altered to investigate fracture transmissivity

  15. Mechanical properties, mineralogical composition, and micro fabric of Opalinus Clay. Sandy and shaly facies (Mont Terri, Switzerland)

    International Nuclear Information System (INIS)

    Kaufhold, Annette; Graesle, Werner; Plischke, Ingo

    2015-01-01

    For the safe disposal of high-level radioactive waste, different host rocks are currently considered. The favorable properties of claystone are low permeability, retention capacity for some radionuclides, and the ability to self-seal cracks, e.g. by swelling or time-dependent compaction creep. For the understanding of the long-term behavior of clay host rocks, the interaction between mechanical behavior, micro fabric, and mineral composition has to be understood (Bock et al., 2010). In the international research project Mont Terri (Switzerland) the Opalinus Clay (Jurassic Formation) is investigated in an underground rock laboratory (URL). In the present study the relationship between mechanical, mineralogical and micro fabric properties were studied on representative samples of the sandy and shaly facies of the Opalinus Clay (OPA) from Mont Terri. The mineral composition of all samples was analysed by using a complex mineral phase analysis. Therefore, the results of the X-ray diffraction, X-ray fluoreszence, organic and inorganic carbonate analysis (LECO) were adjusted with each other. In the case of the sandy facies (OPA) the mechanical strength inrcreases with increasing carbonate content. Here small carbonate particles form the matrix and act as stabilisator. The carbonates of the shaly facies (OPA), on the other hand, are mainly fossil fragments (e.g. shells) aligned parallel to bedding. These large carbonate particles are acting as predetermined breaking surfaces. Hence, in the case of shaly facies (OPA) the mechanical strength decreases with increasing carbonate content. Image Analyses (Fiji registered ) of scattering electron microscope images of polished sections proved the determined microstructural differences. Besides, carbonate particles in the sandy facies are mostly isometric, in contrast carbonates of the shaly facies show different shapes. This is explained further in terms of the aspect ratio. The mechanical tests were carried out as triaxial

  16. Mechanical properties, mineralogical composition, and micro fabric of Opalinus Clay. Sandy and shaly facies (Mont Terri, Switzerland)

    Energy Technology Data Exchange (ETDEWEB)

    Kaufhold, Annette; Graesle, Werner [BGR Hannover (Germany); Plischke, Ingo

    2015-07-01

    For the safe disposal of high-level radioactive waste, different host rocks are currently considered. The favorable properties of claystone are low permeability, retention capacity for some radionuclides, and the ability to self-seal cracks, e.g. by swelling or time-dependent compaction creep. For the understanding of the long-term behavior of clay host rocks, the interaction between mechanical behavior, micro fabric, and mineral composition has to be understood (Bock et al., 2010). In the international research project Mont Terri (Switzerland) the Opalinus Clay (Jurassic Formation) is investigated in an underground rock laboratory (URL). In the present study the relationship between mechanical, mineralogical and micro fabric properties were studied on representative samples of the sandy and shaly facies of the Opalinus Clay (OPA) from Mont Terri. The mineral composition of all samples was analysed by using a complex mineral phase analysis. Therefore, the results of the X-ray diffraction, X-ray fluoreszence, organic and inorganic carbonate analysis (LECO) were adjusted with each other. In the case of the sandy facies (OPA) the mechanical strength inrcreases with increasing carbonate content. Here small carbonate particles form the matrix and act as stabilisator. The carbonates of the shaly facies (OPA), on the other hand, are mainly fossil fragments (e.g. shells) aligned parallel to bedding. These large carbonate particles are acting as predetermined breaking surfaces. Hence, in the case of shaly facies (OPA) the mechanical strength decreases with increasing carbonate content. Image Analyses (Fiji {sup registered}) of scattering electron microscope images of polished sections proved the determined microstructural differences. Besides, carbonate particles in the sandy facies are mostly isometric, in contrast carbonates of the shaly facies show different shapes. This is explained further in terms of the aspect ratio. The mechanical tests were carried out as triaxial

  17. Aspectos biológicos de Diapterus rhombeus (Cuvier (Teleostei, Gerreidae na Baía de Guaratuba, Paraná, Brasil Biological aspects of Diapterus rhombeus (Cuvier (Teleostei, Gerreidae at Guaratuba Bay, Paraná, Brazil

    Directory of Open Access Journals (Sweden)

    Paulo de Tarso da Cunha Chaves

    1998-01-01

    Full Text Available Diapterus rhombeus (Cuvier, 1829 is one of the most common Gerreidae species in the estuarine region at the Guaratuba Bay, Southern Brazil. Based on studies developed between July, 1993 and January, 1997, it was observed that its presence in the mangrove area is not regular: the smallest individuais are more abundam during late summer and in autumn, and the largest ones during spring and early summer. Its diet comprises plant material and invertebrates, specially polychaets. The morphological aspects of the gonads, the monthly changes on the Condition Factor, and lhe monthly distribution of the individual size groups, suggest that this population spawns during the spring, out the estuarine region. The smaller individuais use the mangrove area of Guaratuba Bay to a growth phase, and the adulls to make somatic reserves to the spawning period.

  18. Ontogenic changes in the feeding habits of the fishes Agonostomus monticola (Mugilidae and Brycon behreae (Characidae, Térraba River, Costa Rica

    Directory of Open Access Journals (Sweden)

    Thiago Cotta-Ribeiro

    2009-11-01

    Full Text Available Las dietas de los peces varían con respecto a la calidad, la cantidad y el tamaño del alimento. Esta variación puede deberse a factores como la estacionalidad y la fase del desarrollo del individuo. Estudiamos los cambios ontogénicos en los hábitos alimentarios de dos peces dulceacuícolas, Agonostomus monticola y Brycon behreae, de la Cuenca del Río Térraba, Pacífico sur de Costa Rica. Ambas poblaciones son omnívoras, pero con cambios ontogénicos en la cantidad y calidad de los ítemes consumidos. Conforme crecía, A. monticola modificó su dieta de insectívora hacia un mayor consumo de materia vegetal, asociado con un aumento en la longitud relativa del intestino. Aunque mantuvo su dependencia de alimentos vegetales, B. behreae diversificó su dieta de dos formas. Primero, pasó de partes suaves de plantas a semillas, hojas y frutos. Luego, los ítemes cambiaron de insectos hacia una dieta más carnívora (peces y camarones. Estos hallazgos para ambas especies enfatizan la importancia de proteger la vegetación riparia de estos ecosistemas tropicales.Fish diets can vary in food quality, quantity and size. The variation can be caused by several factors, including season and the ontogenic phase of the individual (McCormick 1998. We studied the ontogenic changes in feeding habits of two freshwater fishes, Agonostomus monticola and Brycon behreae, from the Térraba River basin, South Pacific of Costa Rica. Both populations were omnivorous, but displayed ontogenic shifts in terms of quantity and quality of the food items consumed. As it grew, A. monticola modified its diet from insectivorous towards a higher consumption of vegetables, which was accompanied by an increase in relative length of the intestine. While remaining dependent on vegetation as staple food, B. behreae diversified its diet in two ways. Initially, from soft plant parts to seeds, leaves, and fruits. Secondly, prey items changed from insects into a more carnivore diet

  19. Effect of dietary supplement (cevas on the chemical composition of wild fish Brycon falcatus Müller & Troschel, 1844 in the Teles Pires river basin

    Directory of Open Access Journals (Sweden)

    Liliane Stedile Matos

    2017-05-01

    Full Text Available In the Teles Pires River watershed, one of the most common techniques currently used by fishermen to catch fish is to provide a food supplement commonly known as “cevas”. The purpose of this study was to compare the chemical composition of fillets from Brycon falcatus that were caught in both the presence and absence of cevas. The fish were sampled monthly and captured in the following conditions: the Tapaiúna River without cevas, the Teles Pires River with one ceva/100 m, the Celeste River with one ceva/500 m, the Verde River with one ceva/1000 m and the Cristalino River (control area. Subsequent to capture, the fish were euthanized and preserved on ice to determine their water, ash, crude protein and fat contents. Fillets of fish from the control area exhibited a lower level of crude protein (17.81% compared with that of fish from the other rivers, which did not differ amongst one other. The fillets of fish from the river with the greatest density of cevas (1/100 m exhibited a higher fat content (3.63% than that of fish from the control area (1.51%. Thus, the cevas changed the chemical composition of B. falcatus fillets.

  20. Distribution of Agonostomus monticola and Brycon behreae in the Río Grande de Térraba, Costa Rica and relations with water flow

    Directory of Open Access Journals (Sweden)

    Thiago Cotta Ribeiro

    Full Text Available Fish monthly samples were made in three tributaries and in the main stream in order to study population dynamics and the influence of flow on abundance of Agonostomus monticola (Mugilidae and Brycon behreae (Characidae in the basin of Térraba River Basin (Costa Rica. Flow was seasonal in these rivers, with peak flow in October. Recruitment was different among the species, B. behreae recruited from January to June and A. monticola all year round with a peak in June-July and October-November. Juveniles were more abundant in smaller streams. Abundance was higher in general during low flow and low turbidity periods. The results suggest that the streams have an important role in the maintenance of both species in the ecosystem, where juveniles can use the streams as nursing habitats during their development, allowing these small streams to be considered as essential fish habitats. Also, it was determined that the increased volume and turbidity of water can significantly affect the proportion of adults and juveniles between the main river and its tributaries.

  1. Ontogenic changes in the feeding habits of the fishes Agonostomus monticola (Mugilidae and Brycon behreae (Characidae, Térraba River, Costa Rica

    Directory of Open Access Journals (Sweden)

    Thiago Cotta-Ribeiro

    2009-11-01

    Full Text Available Las dietas de los peces varían con respecto a la calidad, la cantidad y el tamaño del alimento. Esta variación puede deberse a factores como la estacionalidad y la fase del desarrollo del individuo. Estudiamos los cambios ontogénicos en los hábitos alimentarios de dos peces dulceacuícolas, Agonostomus monticola y Brycon behreae, de la Cuenca del Río Térraba, Pacífico sur de Costa Rica. Ambas poblaciones son omnívoras, pero con cambios ontogénicos en la cantidad y calidad de los ítemes consumidos. Conforme crecía, A. monticola modificó su dieta de insectívora hacia un mayor consumo de materia vegetal, asociado con un aumento en la longitud relativa del intestino. Aunque mantuvo su dependencia de alimentos vegetales, B. behreae diversificó su dieta de dos formas. Primero, pasó de partes suaves de plantas a semillas, hojas y frutos. Luego, los ítemes cambiaron de insectos hacia una dieta más carnívora (peces y camarones. Estos hallazgos para ambas especies enfatizan la importancia de proteger la vegetación riparia de estos ecosistemas tropicales.

  2. Biogeochemical processes in a clay formation in situ experiment: Part E - Equilibrium controls on chemistry of pore water from the Opalinus Clay, Mont Terri Underground Research Laboratory, Switzerland

    Energy Technology Data Exchange (ETDEWEB)

    Pearson, F.J., E-mail: fjpearson@gmail.com [Ground-Water Geochemistry, 5108 Trent Woods Dr., New Bern, NC 28562 (United States); Tournassat, Christophe; Gaucher, Eric C. [BRGM, B.P. 36009, 45060 Orleans Cedex 2 (France)

    2011-06-15

    Highlights: > Equilibrium models of water-rock reactions in clay rocks are reviewed. > Analyses of pore waters of the Opalinus Clay from boreholes in the Mont Terri URL, Switzerland, are tabulated. > Results of modelling with various mineral controls are compared with the analyses. > Best agreement results with calcite, dolomite and siderite or daphnite saturation, Na-K-Ca-Mg exchange and/or kaolinite, illite, quartz and celestite saturation. > This approach allows calculation of the chemistry of pore water in clays too impermeable to yield water samples. - Abstract: The chemistry of pore water (particularly pH and ionic strength) is an important property of clay rocks being considered as host rocks for long-term storage of radioactive waste. Pore waters in clay-rich rocks generally cannot be sampled directly. Instead, their chemistry must be found using laboratory-measured properties of core samples and geochemical modelling. Many such measurements have been made on samples from the Opalinus Clay from the Mont Terri Underground Research Laboratory (URL). Several boreholes in that URL yielded water samples against which pore water models have been calibrated. Following a first synthesis report published in 2003, this paper presents the evolution of the modelling approaches developed within Mont Terri URL scientific programs through the last decade (1997-2009). Models are compared to the composition of waters sampled during dedicated borehole experiments. Reanalysis of the models, parameters and database enabled the principal shortcomings of the previous modelling efforts to be overcome. The inability to model the K concentrations correctly with the measured cation exchange properties was found to be due to the use of an inappropriate selectivity coefficient for Na-K exchange; the inability to reproduce the measured carbonate chemistry and pH of the pore waters using mineral-water reactions alone was corrected by considering clay mineral equilibria. Re

  3. Project Entsorgungsnachweis, 'Demonstration of disposal feasibility for SF/HLW/ILW in the Opalinus Clay of the Zuercher Weinland', Background, Objectives and Overview

    International Nuclear Information System (INIS)

    Schneider, Juerg; Zuidema, P.

    2004-01-01

    Juerg Schneider (Nagra, Switzerland) described the project on the Opalinus Clay (Project Entsorgungsnachweis, demonstration of disposal feasibility for SF/HLW/ILW in the Opalinus Clay of the Zuercher Weinland) for which the main objective is to demonstrate disposal feasibility and to provide input to the decision how to proceed. The report structure was described, the focus of the presentation being the report that aimed to provide a comprehensive assessment of long-term safety. The current situation was described in the presentation as follows: - The key need is to provide arguments for having proposed a good system for which there is sufficient understanding to allow a credible safety evaluation. - Alternative options exist, on which attention is maintained by a task-force. However, Nagra is confident in its results on Project Entsorgungsnachweis, given the knowledge base that currently exists, and has put forward a proposal, for consideration by the Swiss Government, to focus future work on the Opalinus Clay (OPA) of the Zuercher Weinland. - Making the safety case requires a proper integration of science, engineering and safety assessment. - Three key issues were identified in making a safety case: completeness, sufficient safety, and robustness to diminish the importance of uncertainties. - A safety case needs to be adequate to support a decision to proceed to the next stage in the programme, with multiple arguments including the existence of reserve FEP's. - The interacting functions of the relevant teams were viewed as a key component of the process of preparing a safety case: management; science; safety assessment; bias audit. During the discussion, the role of the bias team was recognised as being helpful to ensure completeness, as well as using the NEA FEP database as a check list. When speaking about sufficient safety, it should not imply predictive capability but rather that there is enough confidence in the current level of understanding to

  4. Efectos del sistema de conservación sobre la fertilidad de oocitos de yamú (Brycon amazonicus) durante cortos períodos de almacenamiento

    DEFF Research Database (Denmark)

    Velasco-Santamaría, Yohana M.; Corredor-Santamaría, Wilson; Cruz-Casallas, Pablo E.

    2006-01-01

    El objetivo fue evaluar los efectos del sistema de conservación sobre la fertilidad de oocitos de yamú (Brycon amazonicus) durante cortos períodos de almacenamiento. Se utilizaron hembras y machos adultos tratados con extracto de hipófisis de carpa para estimular la ovulación y aumentar el volumen...... larvas. Bajo los tres sistemas de conservación, DO aumentó con el tiempo, siendo mayor (pmayores DO fueron observados en oocitos conservados a T°R (p

  5. Hydro-mechanical analysis of results acquired by video-observations and deformation measurements performed in boreholes in the Opalinus clay of the URL Mont Terri supported by laboratory investigations on the hydro-mechanical behaviour of Opalinus clay

    International Nuclear Information System (INIS)

    Seeska, R.; Rutenberg, M.; Lux, K.H.

    2012-01-01

    Document available in extended abstract form only. Seven different boreholes in the Opalinus Clay formation of the Mont Terri Underground Rock Laboratory (URL Mont Terri) have been investigated by the Clausthal University of Technology (TUC) in cooperation with different partners with time, namely the National Cooperative for the Disposal of Radioactive Waste (NAGRA), the Federal Institute for Geosciences and Natural Resources (BGR) as well as the Swiss Federal Institute of Technology Zurich (ETHZ) and the Swiss Federal Nuclear Safety Inspectorate (ENSI). Aim of the investigations was to gain a large amount of high-quality and significant information on rock mass behaviour that can be used to increase knowledge about and improve understanding of time-dependent load-bearing and deformation behaviour of Opalinus Clay including pore water influences. For this purpose, an axial borehole camera and a three-arm calliper have been used. High-quality information on the load-bearing and deformation behaviour of the investigated boreholes was generated by the measurement and monitoring techniques used in the research project. The recordings reveal great as well as occasionally unexpected differences regarding the load-bearing behaviour as well as differences regarding the hydro-mechanical behaviour of the observed boreholes. While most of the boreholes have proved to be rather stable with only partial failure of the borehole wall in some areas, a complete borehole wall collapse occurred in two of the observed boreholes. The differences regarding the borehole wall stability and also the differences between the appearances of the occurring failure mechanisms are very likely due to the different orientation, the different locations within the URL Mont Terri, and the different facies the boreholes are located in. Figure 1 shows the time-dependent development of a borehole wall instability in one of the observed boreholes in a borehole section where an increase of moisture could

  6. Monitoring water content in Opalinus Clay within the FE-Experiment: Test application of dielectric water content sensors

    Science.gov (United States)

    Sakaki, T.; Vogt, T.; Komatsu, M.; Müller, H. R.

    2013-12-01

    The spatiotemporal variation of water content in the near field rock around repository tunnels for radioactive waste in clay formations is one of the essential quantities to be monitored for safety assessment in many waste disposal programs. Reliable measurements of water content are important not only for the understanding and prediction of coupled hydraulic-mechanic processes that occur during tunnel construction and ventilation phase, but also for the understanding of coupled thermal-hydraulic-mechanical (THM) processes that take place in the host rock during the post closure phase of a repository tunnel for spent fuel and high level radioactive waste (SF/HLW). The host rock of the Swiss disposal concept for SF/HLW is the Opalinus Clay formation (age of approx. 175 Million years). To better understand the THM effects in a full-scale heater-engineered barrier-rock system in Opalinus Clay, a full-scale heater test, namely the Full-Scale Emplacement (FE) experiment, was initiated in 2010 at the Mont Terri underground rock laboratory in north-western Switzerland. The experiment is designed to simulate the THM evolution of a SF/HLW repository tunnel based on the Swiss disposal concept in a realistic manner during the construction, emplacement, backfilling, and post-closure phases. The entire experiment implementation (in a 50 m long gallery with approx. 3 m diameter) as well as the post-closure THM evolution will be monitored using a network of several hundred sensors. The sensors will be distributed in the host rock, the tunnel lining, the engineered barrier, which consists of bentonite pellets and blocks, and on the heaters. The excavation is completed and the tunnel is currently being ventilated. Measuring water content in partially saturated clay-rich high-salinity rock with a deformable grain skeleton is challenging. Therefore, we use the ventilation phase (before backfilling and heating) to examine the applicability of commercial water content sensors and to

  7. Diffusion Experiments with Opalinus and Callovo-Oxfordian Clays: Laboratory, Large-Scale Experiments and Microscale Analysis by RBS

    International Nuclear Information System (INIS)

    Garcia-Gutierrez, M.; Alonso, U.; Missana, T.; Cormenzana, J.L.; Mingarro, M.; Morejon, J.; Gil, P.

    2009-01-01

    Consolidated clays are potential host rocks for deep geological repositories for high-level radioactive waste. Diffusion is the main transport process for radionuclides (RN) in these clays. Radionuclide (RN) diffusion coefficients are the most important parameters for Performance Assessment (PA) calculations of clay barriers. Different diffusion methodologies were applied at a laboratory scale to analyse the diffusion behaviour of a wide range of RN. Main aims were to understand the transport properties of different RNs in two different clays and to contribute with feasible methodologies to improve in-situ diffusion experiments, using samples of larger scale. Classical laboratory essays and a novel experimental set-up for large-scale diffusion experiments were performed, together to a novel application of the nuclear ion beam technique Rutherford Backscattering Spectrometry (RBS), for diffusion analyses at the micrometer scale. The main experimental and theoretical characteristics of the different methodologies, and their advantages and limitations are here discussed. Experiments were performed with the Opalinus and the Callovo-Oxfordian clays. Both clays are studied as potential host rock for a repository. Effective diffusion coefficients ranged between 1.10 - 10 to 1.10 - 12 m 2 /s for neutral, low sorbing cations (as Na and Sr) and anions. Apparent diffusion coefficients for strongly sorbing elements, as Cs and Co, are in the order of 1.10-13 m 2 /s; europium present the lowest diffusion coefficient (5.10 - 15 m 2 /s). The results obtained by the different approaches gave a comprehensive database of diffusion coefficients for RN with different transport behaviour within both clays. (Author) 42 refs

  8. Diffusion Experiments with Opalinus and Callovo-Oxfordian Clays: Laboratory, Large-Scale Experiments and Microscale Analysis by RBS

    Energy Technology Data Exchange (ETDEWEB)

    Garcia-Gutierrez, M.; Alonso, U.; Missana, T.; Cormenzana, J.L.; Mingarro, M.; Morejon, J.; Gil, P.

    2009-09-25

    Consolidated clays are potential host rocks for deep geological repositories for high-level radioactive waste. Diffusion is the main transport process for radionuclides (RN) in these clays. Radionuclide (RN) diffusion coefficients are the most important parameters for Performance Assessment (PA) calculations of clay barriers. Different diffusion methodologies were applied at a laboratory scale to analyse the diffusion behaviour of a wide range of RN. Main aims were to understand the transport properties of different RNs in two different clays and to contribute with feasible methodologies to improve in-situ diffusion experiments, using samples of larger scale. Classical laboratory essays and a novel experimental set-up for large-scale diffusion experiments were performed, together to a novel application of the nuclear ion beam technique Rutherford Backscattering Spectrometry (RBS), for diffusion analyses at the micrometer scale. The main experimental and theoretical characteristics of the different methodologies, and their advantages and limitations are here discussed. Experiments were performed with the Opalinus and the Callovo-Oxfordian clays. Both clays are studied as potential host rock for a repository. Effective diffusion coefficients ranged between 1.10{sup -}10 to 1.10{sup -}12 m{sup 2}/s for neutral, low sorbing cations (as Na and Sr) and anions. Apparent diffusion coefficients for strongly sorbing elements, as Cs and Co, are in the order of 1.10-13 m{sup 2}/s; europium present the lowest diffusion coefficient (5.10{sup -}15 m{sup 2}/s). The results obtained by the different approaches gave a comprehensive database of diffusion coefficients for RN with different transport behaviour within both clays. (Author) 42 refs.

  9. Effects of post-disposal gas generation in a repository for spent fuel, high-level waste and long-lived intermediate level waste sited in opalinus clay

    International Nuclear Information System (INIS)

    Johnson, L.; Marschall, P.; Zuidema, P.; Gribi, P.

    2004-07-01

    This comprehensive report issued by the Swiss National Cooperative for the Disposal of Radioactive Waste NAGRA takes a look at post-disposal gas generation in a repository for spent fuel and highly radioactive wastes in Opalinus clay strata. This study provides a comprehensive treatment of the issue of gas generation in a repository for spent fuel (SF), vitrified high-level waste (HLW) and long-lived intermediate-level waste (ILW), sited in the Opalinus clay of the Zuercher Weinland in northern Switzerland. The issue of how gas generation in and transport from waste repositories may influence disposal system performance has been under study for many years, both at Nagra and internationally. The report consists of three main parts: (i) A synthesis of basic information on the host rock and on details of repository construction; (ii) A discussion on gas transport characteristics of the engineered barrier system and the geosphere; (iii) A discussion on the effects of gas on system performance, based on the available information on gas generation, gas transport properties and gas pathways provided in the previous parts of the report. Simplified model calculations based on a mass balance approach for the gas generated within the repository are presented and discussed

  10. Comparative study on hematological parameters of farmed matrinxã, Brycon amazonicus Spix and Agassiz, 1829 (Characidae: Bryconinae with others Bryconinae species Estudo comparativo sobre parâmetros hematológicos de matrinxã Brycon amazonicus Spix e Agassiz, 1892(Characidae: Bryconinae criados em cativeiro, com outras espécies de Bryconinae

    Directory of Open Access Journals (Sweden)

    Marcos Tavares-Dias

    2008-12-01

    Full Text Available The aim of this study was not only to determine the red blood cells parameters, thrombocyte and leukocyte counts in farmed Brycon amazonicus (matrinxã, to compare these parameters among Bryconinae species from literature, and also to investigate the presence of special granulocytic cells in these fish. The results of the blood cells parameters here established for farmed B. amazonicus, a species of great economic importance in Brazilian aquaculture, could help a better understanding of the blood features in natural populations of this Amazon species. Blood parameters varied between Bryconinae species investigated, mainly the red blood cell counts, hemoglobin, hematocrit and mean corpuscular volume (MCV. The presence of the blood granulocytes, neutrophils and heterophils in matrinxã suggest that both leukocytes can be a characteristic for Bryconinae family. Furthermore, it indicates that the existence of special granulocytic cells in the blood of Bryconinae species from literature is an artifact, and this was herein discussed.O objetivo deste estudo foi determinar os parâmetros eritrocíticos, as contagens de trombócitos e de leucócitos de espécimes de Brycon amazonicus (matrinxã, criados em cativeiro e compará-los com aqueles descritos na literatura para outras espécies de Bryconinae. Além disso, foi ainda investigada a presença de células granulocíticas especiais nestes peixes. Os resultados dos parâmetros sangüíneos apresentados para B. amazonicus podem ajudar a entender melhor as características sangüíneas em população natural desta espécie de grande importância para a aqüicultura brasileira. Os parâmetros sangüíneos das espécies de Bryconinae investigadas apresentaram variação interespecíficas principalmente a contagem de eritrócitos, hemoglobina, hematócrito e volume corpuscular médio (VCM. A presença dos granulócitos sangüíneos, neutrófilos e heterófilos em matrinxã sugere que esta pode ser uma

  11. Alterações bioquímicas post-mortem de matrinxã Brycon cephalus (Günther, 1869 procedente da piscicultura, mantido em gelo Post-mortem biochemical alterations in aquacultured matrinxã fish Brycon cephalus (Günther, 1869 when stored on ice

    Directory of Open Access Journals (Sweden)

    Gilvan Machado Batista

    2004-12-01

    Full Text Available No presente trabalho, foram estudadas as alterações bioquímicas post-mortem que ocorreram em matrinxã Brycon cephalus (Günther, 1869 procedente da piscicultura e mantido em gelo em Manaus - AM. Foi determinado o tempo de estocagem em gelo por meio das avaliações sensoriais físicas e gustativas, das análises de pH, Nitrogênio das Bases Voláteis Totais (N-BVT e bacteriológicas durante 29 dias. Foram determinados os índices de rigor-mortis, as concentrações de ATP e seus produtos de degradações e o valor K. De acordo com a composição química, o peixe foi classificado como "semi-gordo". Os peixes entraram em rigor-mortis aos 75 minutos após a morte por hipotermia, tendo permanecido durante 10 dias. As avaliações sensoriais (físicas e gustativas mostraram que os peixes apresentaram condição de consumo até 26 dias. As análises de ATP e de seus produtos de degradação mostraram que a referida espécie foi considerada formadora de inosina (HxR, nas condições de experimento. O valor K mostrou que os exemplares de matrinxãs permaneceram "muito frescos" até 16 dias de estocagem em gelo, concordante com a avaliação sensorial gustativa.Post-mortem biochemical alterations in aquacultured matrinxã fish Brycon cephalus (Günther, 1869 when stored on ice in Manaus-AM, were studied in this paper. The storage time on ice was determined through tasting and physical sensory evaluations, pH, total volatile bases nitrogen (TVB-N and bacteriological analyses during 29 days. Rigor-mortis index, ATP-related compounds and K value were also determined. Chemical composition demonstrated that fish was classified as "semi-fat". The specimens presented rigor-mortis 75 minutes after death caused by hypothermia and remained that way for 10 days. Shelf life time on ice was 26 days, according to sensory evaluations, pH, TVBN determinations and bacteriological analyses. ATP-related compounds pointed out that the referred species was considered to

  12. Development of fingerlings of Piracanjuba (Brycon orbignyannus, Vallencienes (1849 (Teleostei: characidae in tanks fertilized with organic manures/ Desenvolvimento de juvenis de Piracanjuba (Brycon orbignyannus, Vallencienes (1849 (Teleostei: characidae em tanques experimentais fertilizados com adubação orgânica

    Directory of Open Access Journals (Sweden)

    Carmino Hayashi

    2005-06-01

    Full Text Available The objective of this paper was to study the development of Piracanjuba (Brycon orbignyanus in tanks under differents organic fertilizers. The experiment, entirely randomized, was accomplished in 16 tanks of 1000 liters, fertilized with manures of bovine (BOV, pigs (SUI, chickens (FRG and others without fertilizer (SAO, using 15 fish/m3 with an initial average weight and length of 10,87+0,31 g e 9,78+0,07 cm. After 30 days, the experiment showed a uniform development of the fish and high survival rate in thestudied density. The treatments presented significant statistical differences (PO objetivo deste trabalho foi estudar o desenvolvimento de juvenis de Piracanjuba (Brycon orbignyanus, em tanques com adubações orgânicas. O experimento, inteiramente casualizado, foi realizado em 16 tanques de 1000 litros, adubados com estercos de bovinos (BOV, suínos (SUI, frangos de corte (FRG e outros sem adubação (SAO, utilizando 15 peixes/m3 com peso e comprimento médios iniciais de 10,87+0,31 g e 9,78+0,07 cm. Após 30 dias, o experimento mostrou um desenvolvimento uniforme dos peixes e alta taxa de sobrevivência na densidade estudada. Os tratamentos apresentaram diferenças estatisticamente significativas (p < 0,05 para ganho de peso e crescimento diário, com exceção dos tratamentos BOV e SUI quando comparados entre si. A temperatura e o oxigênio dissolvido foram os fatores abióticos que exerceram maior influência sobre a biota aquática, afetando o desenvolvimento dos peixes. Entre o fitoplâncton houve maior abundância de organismos nanoplanctônicos favorecendo o desenvolvimento do zooplâncton, destacando-se as clorófitas, com o gênero Scenedesmus, e as cianofíceas, com o gênero Microcystis, e entre o zooplâncton, a maior abundância foi de rotíferos dos gêneros Brachionus e Keratella, seguido por copépodas. O tratamento adubado com esterco de frangos possibilitou um maior desenvolvimento da comunidade planctônica, e melhores

  13. Anatomia funcional e morfometria dos intestinos e dos cecos pilóricos do teleostei (pisces de água doce Brycon orbignyanus (Valenciennes, 1849

    Directory of Open Access Journals (Sweden)

    Seixas Filho José Teixeira de

    2000-01-01

    Full Text Available O objetivo do presente trabalho foi estudar a anatomia funcional e a morfometria comparativas nos intestinos médio e posterior e nos cecos pilóricos da piracanjuba (Brycon orbignyanus Valenciennes, 1849 (Characiformes, Characidae, Bryconinae. Foram conduzidos estudos anatomofuncionais e morfométricos nos intestinos médio e posterior e nos cecos pilóricos dessa espécie com hábito alimentar onívoro. Constatou-se, por meio destes estudos, que o padrão de enrolamento das alças intestinais em arranjo em N apresentou, na segunda classe de tamanho, freqüentes variações no intestino médio, mas foi compatível com os de outras espécies de hábitos alimentares similares. Os estudos da morfometria mostraram que o comprimento total do intestino e das alças intestinais e seus calibres, provavelmente, exercem função específica na absorção dos nutrientes. As relações entre o arranjo das pregas da mucosa e a velocidade de transporte do alimento no intestino médio sugerem que os padrões transversal e oblíquo retardam o avanço do alimento em sentido aboral, possibilitando maior período digestivo e melhor aproveitamento dos nutrientes, contribuindo para a preparação do bolo fecal. O comprimento e o calibre dos cecos pilóricos aumentam com o desenvolvimento do peixe, e o seu padrão de mucosa possui características anatômicas semelhantes às do intestino.

  14. Alimentação de Bairdiella ronchus (Cuvier (Perciformes, Sciaenidae na Baía de Guaratuba, Paraná, Brasil Feeding of Bairdiella ronchus (Cuvier (Perciformes, Sciaenidae at the Guaratuba Bay, Paraná, Brazil

    Directory of Open Access Journals (Sweden)

    Ana Lúcia Vendel

    1998-01-01

    Full Text Available Seasonal variation of food items of Bairdiella ronchus (Cuvier, 1830 classified by size was analysed based on monthly samples between september/1993 and september/1996 at the Guaratuba Bay, Southern Brazil. The stomach contents of a hundred eighty-two fishes were analysed by the Occunence Frequency Method and Point Count for a Lot Method. The individuais were divided in two groups, smaller and longer than 140mm, and a comparative study of digestive tract and branchial are was performed for these groups. For fishes smaller than 140mm the following sequence of items was obtained matching both methods by using the Preponderance índices: decapods (subdivided in Brachyura, Caridea and Penaeidea, polychaets, isopods, fishes, unidentified material, copepods, amphipods, molluscs and plant material. For fishes longer than or equal to 140mm the sequence was decapods, polychaets, fishes, copepods, amphipods, isopods, molluscs and plant material, in this order. These results suggest that Bairdiella ronchus at the Guaratuba Bay is a carnivorous species using mainly decapod crustaceans as food throughout the year.

  15. Excavation Induced Hydraulic Response of Opalinus Clay - Investigations of the FE-Experiment at the Mont Terri URL in Switzerland

    Science.gov (United States)

    Vogt, T.; Müller, H. R.; Garitte, B.; Sakaki, T.; Vietor, T.

    2013-12-01

    The Full-Scale Emplacement (FE) Experiment at the Mont Terri underground research laboratory in Switzerland is a full-scale heater test in a clay-rich formation (Opalinus Clay). Based on the Swiss disposal concept it simulates the construction, emplacement, backfilling, and post-closure thermo-hydro-mechanical (THM) evolution of a spent fuel / vitrified high-level waste (SF / HLW) repository tunnel in a realistic manner. The main aim of this experiment is to investigate SF / HLW repository-induced THM coupled effects mainly in the host rock but also in the engineered barrier system (EBS), which consists of bentonite pellets and blocks. A further aim is to gather experience with full-scale tunnel construction and associated hydro-mechanical (HM) processes in the host rock. The entire experiment implementation (in a 50 m long gallery with approx. 3 m diameter) as well as the post-closure THM evolution will be monitored using a network of several hundred sensors (state-of-the-art sensors and measurement systems as well as fiber-optic sensors). The sensors are distributed in the host rock's near- and far-field, the tunnel lining, the EBS, and on the heaters. The heater emplacement and backfilling has not started yet, therefore only the host rock instrumentation is installed at the moment and is currently generating data. We will present the instrumentation concept and rationale as well as the first monitoring results of the excavation and ventilation phase. In particular, we investigated the excavation induced hydraulic response of the host rock. Therefore, the spatiotemporal evolution of porewater-pressure time series was analyzed to get a better understanding of HM coupled processes during and after the excavation phase as well as the impact of anisotropic geomechanic and hydraulic properties of the clay-rich formation on its hydraulic behavior. Excavation related investigations were completed by means of inclinometer data to characterize the non-elastic and time

  16. Trophic Ecology and Movement Patters of Tiger Sharks (Galeocerdo Cuvier) off the Western North Atlantic Coastal and Continental Shelf Waters

    Science.gov (United States)

    Sancho, G.; Edman, R.; Frazier, B.; Bubley, W.

    2016-02-01

    Understanding the trophic dynamics and habitat utilization of apex predators is central to inferring their influence on different marine landscapes and to help design effective management plans for these animals. Tiger sharks (Galeocerdo cuvier) are abundant in shelf and offshore Gulf Stream waters of the western North Atlantic Ocean, and based on movements from individuals captured in Florida and Bahamas, seem to avoid coastal and shelf waters off South Carolina and Georgia. This contradicts reports of tiger sharks regularly being caught nearshore by anglers in these states, indicating that separate sub-populations may exist in the western North Atlantic. In the present study we captured Tiger Sharks in coastal waters off South Carolina in 2014 and 2015 in order to describe their movement patterns through acoustic and satellite tagging, and trophic dynamics through stable isotope analyses. Movement data show that these tiger sharks repeatedly visit particular inshore areas and mainly travel over the continental shelf, but rarely venture offshore beyond the continental shelf edge. Ongoing C and N stable isotope analyses of muscle, blood and skin tissues from adult and juvenile tiger sharks, as well as from potential prey species and primary producers, will help determine if their diets are based on inshore, shelf or offshore based food webs. Tiger sharks exploiting nearshore environments and shelf waters have much higher probabilities of interacting with humans than individuals occupying far offshore Gulf Stream habitats.

  17. Ontogenic events and swimming behavior of larvae of the characid fish Salminus brasiliensis (Cuvier (Characiformes, Characidae under laboratory conditions

    Directory of Open Access Journals (Sweden)

    José Enemir dos Santos

    2002-03-01

    Full Text Available The larval ontogeny and swimming behavior of the characid fish Salminus brasiliensis (Cuvier, 1816 were studied under experimental laboratory conditions, from hatching to yolk absorption. At day 1, the larvae were transparent, with sparse dendrite chromatophores and a well-developed adhesive organ on the head. The retinal epithelial cells were initiating pigmentation. The branchial arches were at the initial phase of differentiation. The larvae were able to perform only vertical displacements and, when resting on the tank bottom, remained in lateral decumbency, in groups of 3 to 15 larvae. On day 2, the mouth was open, with conical teeth, and the digestive tube presented lumen and folded mucosa. The gaseous bladder and pectoral fins also were in differentiation. The larvae performed vertical and horizontal movements, adhered to the water surface by means of the adhesive organ or formed groups of three to six on the tank bottom. On day 3, the adhesive organ turned dorsal, the retina was pigmented, the digestive tube mucosa showed goblet cells, and the yolk sac exhausted. The larvae were now scattering in the water column forming no groups on the bottom.

  18. Pore-water evolution and solute-transport mechanisms in Opalinus Clay at Mont Terri and Mont Russelin (Canton Jura, Switzerland)

    Energy Technology Data Exchange (ETDEWEB)

    Mazurek, M. [Institute of Geological Sciences, University of Berne, Berne (Switzerland); Haller de, A. [Earth and Environmental Sciences, University of Geneva, Geneva (Switzerland)

    2017-04-15

    Data pertinent to pore-water composition in Opalinus Clay in the Mont Terri and Mont Russelin anticlines have been collected over the last 20 years from long-term in situ pore-water sampling in dedicated boreholes, from laboratory analyses on drill cores and from the geochemical characteristics of vein infills. Together with independent knowledge on regional geology, an attempt is made here to constrain the geochemical evolution of the pore-waters. Following basin inversion and the establishment of continental conditions in the late Cretaceous, the Malm limestones acted as a fresh-water upper boundary leading to progressive out-diffusion of salinity from the originally marine pore-waters of the Jurassic low-permeability sequence. Model calculations suggest that at the end of the Palaeogene, pore-water salinity in Opalinus Clay was about half the original value. In the Chattian/Aquitanian, partial evaporation of sea-water occurred. It is postulated that brines diffused into the underlying sequence over a period of several Myr, resulting in an increase of salinity in Opalinus Clay to levels observed today. This hypothesis is further supported by the isotopic signatures of SO{sub 4}{sup 2-} and {sup 87}Sr/{sup 86}Sr in current pore-waters. These are not simple binary mixtures of sea and meteoric water, but their Cl{sup -} and stable water-isotope signatures can be potentially explained by a component of partially evaporated sea-water. After the re-establishment of fresh-water conditions on the surface and the formation of the Jura Fold and Thrust Belt, erosion caused the activation of aquifers embedding the low-permeability sequence, leading to the curved profiles of various pore-water tracers that are observed today. Fluid flow triggered by deformation events during thrusting and folding of the anticlines occurred and is documented by infrequent vein infills in major fault structures. However, this flow was spatially focussed and of limited duration and so did not

  19. Ageing effect on deep-buried argillites stored after coring: study cases of Opalinus Clays and Callovo-Oxfordian argillites

    International Nuclear Information System (INIS)

    Techer, I.; Clauer, N.; Liewig, N.

    2010-01-01

    Document available in extended abstract form only. A petrophysical and geochemical study of deep-seated sediments requires either shaft excavation for in situ investigations or core drilling and storage for laboratory measurements and observations. In both cases, measured and observed data should be as representative as possible of the intrinsic characteristics of the rocks before human interference, which is especially critical for potential host-rocks of deep nuclear-waste storage. Almost instantaneous alteration processes were described due to interactions with the atmosphere by supply of O 2 , CO 2 , and water in some cases. Chemical exchanges and reactions were reported in conditioned and stored samples, despite all the care taken for treatment. The imprint of such processes remains to be very limited and therefore difficult to identify, especially by routine analyses. To provide further information about these limited modifications and to discuss the evolution of the geochemical records in deep clayed rocks when exposed to atmosphere, a coupled mineralogical and geochemical study was performed on two argillaceous rocks: the Opalinus Clays collected in the Mont-Terri URL (Switzerland) and the Callovo-Oxfordian Clays sampled in the Bure URL (France). A ∼8-m long core was drilled perpendicular to an experimental niche or gallery in each underground laboratory. Several core sections were selected as a function of distance to the wall of the niche/gallery and were analyzed repetitively relative to storage time. The samples were stored in Al-bags under vacuum, or not, and at ambient temperature or subjected to temperatures of 95 deg. C and 150 deg. C over varied periods of time, in order to enhance the reactions. The objective was the evaluation of the storage effect on the chemical and Sr isotopic compositions by leaching the rock powders with dilute acetic acid and analyzing the leachates for elemental and 87 Sr/ 86 Sr compositions. The study was complemented

  20. Mont Terri Project - Engineered barrier emplacement experiment in Opalinus Clay for the disposal of radioactive waste in underground repositories

    International Nuclear Information System (INIS)

    Mayor, J. C.; Garcia-Sineriz, J.; Alonso, E.; Alheid, H.-J.; Bluemling, P.

    2007-01-01

    The Engineered Barrier (EB) experiment was a full-scale test for the demonstration, in a horizontal drift, of an emplacement technics of the clay barrier, using a granular bentonite material in the upper part of this barrier and bentonite blocks at the bottom. The test has been carried out in a 6 m long section of a niche excavated in Opalinus Clay of the Mont Terri underground laboratory. A steel dummy canister, with the same dimensions and weight as the real reference canisters, was placed on top of a bed of highly compacted bentonite blocks (in turn lying on a concrete bed), and the rest of the clay barrier volume was backfilled with a Granular Bentonite Material (GBM), made of very highly compacted pellets of different sizes. Hydro-mechanical instrumentation and an artificial hydration system (to accelerate the saturation of the clay barrier) were installed, and the test section sealed with a concrete plug. The evolution of the hydro-mechanical parameters along the hydration, both in the barrier and in the clayey rock formation, has been monitored during about 1.5 years, and modelled using the CODE-BRIGHT code. The EB experiment has proved that fully automated production of a Granular Bentonite Material (GBM) is possible and large quantities can be produced in due time in the required quality. Only minor modifications of existing production lines in industry for other applications were necessary to achieve this result. In the EB test section, a dry density of 1.36 g/cm 3 of the emplaced GBM has been obtained. With this value it is estimated that the hydraulic conductivity of this material is lower than 5 x 10 -12 m/s and the swelling pressure is about 1.3 MPa. Even though the EB test section conditions are now not considered as representative of a true demonstration, it is deemed that the model emplacement testing results (dry density of about 1.40 g/cm 3 ) serve well to demonstrate the achievable densities expected in the real world setting. The artificial

  1. Mont Terri Project - Engineered barrier emplacement experiment in Opalinus Clay for the disposal of radioactive waste in underground repositories

    Energy Technology Data Exchange (ETDEWEB)

    Mayor, J. C. [Empresa Nacional de Residuos Radioactivos SA (ENRESA), Madrid (Spain); Garcia-Sineriz, J. [Asociacion para la Investigacion y Desarollo Industrial de los Recursos Naturales (AITEMIN), Madrid (Spain); Alonso, E. [Centre Internacional de Metodos Numerics en Ingenyeria (CIMNE), Barcelona (Spain); Alheid, H.-J. [Bundesanstalt fuer Geowissenschaften und Rohstoffe (BGR), Hannover (Germany); Bluemling, P. [National Cooperative for the Disposal of Radioactive Waste (Nagra), Wettingen (Switzerland)

    2007-07-01

    The Engineered Barrier (EB) experiment was a full-scale test for the demonstration, in a horizontal drift, of an emplacement technics of the clay barrier, using a granular bentonite material in the upper part of this barrier and bentonite blocks at the bottom. The test has been carried out in a 6 m long section of a niche excavated in Opalinus Clay of the Mont Terri underground laboratory. A steel dummy canister, with the same dimensions and weight as the real reference canisters, was placed on top of a bed of highly compacted bentonite blocks (in turn lying on a concrete bed), and the rest of the clay barrier volume was backfilled with a Granular Bentonite Material (GBM), made of very highly compacted pellets of different sizes. Hydro-mechanical instrumentation and an artificial hydration system (to accelerate the saturation of the clay barrier) were installed, and the test section sealed with a concrete plug. The evolution of the hydro-mechanical parameters along the hydration, both in the barrier and in the clayey rock formation, has been monitored during about 1.5 years, and modelled using the CODE-BRIGHT code. The EB experiment has proved that fully automated production of a Granular Bentonite Material (GBM) is possible and large quantities can be produced in due time in the required quality. Only minor modifications of existing production lines in industry for other applications were necessary to achieve this result. In the EB test section, a dry density of 1.36 g/cm{sup 3} of the emplaced GBM has been obtained. With this value it is estimated that the hydraulic conductivity of this material is lower than 5 x 10{sup -12} m/s and the swelling pressure is about 1.3 MPa. Even though the EB test section conditions are now not considered as representative of a true demonstration, it is deemed that the model emplacement testing results (dry density of about 1.40 g/cm{sup 3}) serve well to demonstrate the achievable densities expected in the real world setting. The

  2. Impact of the electron donor on in situ microbial nitrate reduction in Opalinus Clay: results from the Mont Terri rock laboratory (Switzerland)

    Energy Technology Data Exchange (ETDEWEB)

    Bleyen, N.; Smets, S. [Belgian Nuclear Research Centre SCK-CEN, Mol (Belgium); Small, J. [National Nuclear Laboratory NLL, Warrington (United Kingdom); and others

    2017-04-15

    At the Mont Terri rock laboratory (Switzerland), an in situ experiment is being carried out to examine the fate of nitrate leaching from nitrate-containing bituminized radioactive waste, in a clay host rock for geological disposal. Such a release of nitrate may cause a geochemical perturbation of the clay, possibly affecting some of the favorable characteristics of the host rock. In this in situ experiment, combined transport and reactivity of nitrate is studied inside anoxic and water-saturated chambers in a borehole in the Opalinus Clay. Continuous circulation of the solution from the borehole to the surface equipment allows a regular sampling and online monitoring of its chemical composition. In this paper, in situ microbial nitrate reduction in the Opalinus Clay is discussed, in the presence or absence of additional electron donors relevant for the disposal concept and likely to be released from nitrate-containing bituminized radioactive waste: acetate (simulating bitumen degradation products) and H{sub 2} (originating from radiolysis and corrosion in the repository). The results of these tests indicate that - in case microorganisms would be active in the repository or the surrounding clay - microbial nitrate reduction can occur using electron donors naturally present in the clay (e.g. pyrite, dissolved organic matter). Nevertheless, non-reactive transport of nitrate in the clay is expected to be the main process. In contrast, when easily oxidizable electron donors would be available (e.g. acetate and H{sub 2}), the microbial activity will be strongly stimulated. Both in the presence of H{sub 2} and acetate, nitrite and nitrogenous gases are predominantly produced, although some ammonium can also be formed when H{sub 2} is present. The reduction of nitrate in the clay could have an impact on the redox conditions in the pore-water and might also lead to a gas-related perturbation of the host rock, depending on the electron donor used during denitrification

  3. Oxidative and biochemical responses in Brycon amazonicus anesthetized and sedated with Myrcia sylvatica (G. Mey.) DC. and Curcuma longa L. essential oils.

    Science.gov (United States)

    Saccol, Etiane M H; Londero, Érika P; Bressan, Caroline A; Salbego, Joseânia; Gressler, Luciane T; Silva, Lenise V F; Mourão, Rosa H V; Oliveira, Ricardo B; Llesuy, Susana F; Baldisserotto, Bernardo; Pavanato, Maria A

    2017-05-01

    To investigate the effects of rapid anesthesia and long-term sedation with the essential oils (EOs) of Myrcia sylvatica (EOMS) and Curcuma longa (EOCL) on biochemical and oxidative parameters in matrinxã. Prospective, randomized, laboratory experiment. A total of 72 matrinxã (Brycon amazonicus) adults weighing 404.8 ± 27.9 g were divided into eight groups of nine fish. Biochemical and oxidative effects were investigated in plasma and tissues of matrinxã subjected to rapid anesthesia (5 minutes) or long-term sedation (360 minutes, simulating the practice of transport) with EOMS (200 μL L -1 and 10 μL L -1 , respectively) and EOCL (500 μL L -1 and 40 μL L -1 , respectively). Transport simulation without sedation or anesthesia increased lipid peroxidation levels in the gills and kidney of fish in the control group. Anesthesia and sedation with EOs decreased cortisol concentrations and increased lactate concentrations compared with controls. Lipid peroxidation was lower in the brain, gills, liver and kidney of sedated and anesthetized fish, than in the control group. Anesthesia with EOs increased the activity of superoxide dismutase and glutathione-S-transferase in the brain, and catalase in the liver and gills, compared with controls. Long-term sedation with EOs increased superoxide dismutase, glutathione peroxidase and glutathione reductase activities in the brain, catalase in the liver, glutathione peroxidase and glutathione reductase in the gills and superoxide dismutase in the kidney. In general, nonprotein thiols content and total reactive antioxidant potential of tissues were higher after anesthesia and sedation with EOs compared with the control group. The concentrations of EOMS and EOCL used were effective at preventing a stress response and excess of reactive oxygen species formation. For these reasons, these substances may be recommended for use in the transportation of fish to improve survival and animal welfare. Copyright © 2017

  4. Ontogeny of head and caudal fin shape of an apex marine predator: The tiger shark (Galeocerdo cuvier).

    Science.gov (United States)

    Fu, Amy L; Hammerschlag, Neil; Lauder, George V; Wilga, Cheryl D; Kuo, Chi-Yun; Irschick, Duncan J

    2016-05-01

    How morphology changes with size can have profound effects on the life history and ecology of an animal. For apex predators that can impact higher level ecosystem processes, such changes may have consequences for other species. Tiger sharks (Galeocerdo cuvier) are an apex predator in tropical seas, and, as adults, are highly migratory. However, little is known about ontogenetic changes in their body form, especially in relation to two aspects of shape that influence locomotion (caudal fin) and feeding (head shape). We captured digital images of the heads and caudal fins of live tiger sharks from Southern Florida and the Bahamas ranging in body size (hence age), and quantified shape of each using elliptical Fourier analysis. This revealed changes in the shape of the head and caudal fin of tiger sharks across ontogeny. Smaller juvenile tiger sharks show an asymmetrical tail with the dorsal (upper) lobe being substantially larger than the ventral (lower) lobe, and transition to more symmetrical tail in larger adults, although the upper lobe remains relatively larger in adults. The heads of juvenile tiger sharks are more conical, which transition to relatively broader heads over ontogeny. We interpret these changes as a result of two ecological transitions. First, adult tiger sharks can undertake extensive migrations and a more symmetrical tail could be more efficient for swimming longer distances, although we did not test this possibility. Second, adult tiger sharks expand their diet to consume larger and more diverse prey with age (turtles, mammals, and elasmobranchs), which requires substantially greater bite area and force to process. In contrast, juvenile tiger sharks consume smaller prey, such as fishes, crustaceans, and invertebrates. Our data reveal significant morphological shifts in an apex predator, which could have effects for other species that tiger sharks consume and interact with. © 2016 Wiley Periodicals, Inc.

  5. Morphofunctional description of mucous cells in the gills of the Arapaimidae Arapaima gigas (Cuvier) during its development.

    Science.gov (United States)

    Ramos, C A; da Costa, O T F; Duncan, W L P; Fernandes, M N

    2018-05-07

    The gill structure of the Amazonian fish Arapaima gigas (Cuvier 1829) shows ontogenetic changes during development, particularly due the transition from the aquatic to the obligatory air breathing mode of respiration. However, three main cell types can be found in the gills: mitochondrial rich cells, pavement cells and mucous cells (MCs). The MCs are involved in the secretory pathway. The functions of the secreted molecules include mechanical protection of epithelia, protection against parasites and bacterial infection, and role on ion regulation. In this study, we analysed mucous cell location and mucous cell type, based on pH, during the development of A. gigas. Using samples obtained from the environment, gills were collected and fixed in buffered solution. Histological techniques for the identification of MCs were performed Alcian Blue (AB) and periodic acid-Schiff (PAS). The results showed the presence of PAS+ and AB+ cells in the whole filament in all examined fish. In animals less than 50 g, few MCs were present, and no differences were observed in AB+ and PAS+ cells. In animals weighing close to 500 g, more PAS+ cells than AB+ cells were observed, and in animals that weighed more than 1,000 g, more AB+ cells than PAS+ cells were observed. These observations may be a result of the ontogenetic changes in the gill epithelia, which can change the osmorespiratory compromise in ion regulation functions as well the glycosaminoglycans secreted by PAS cells, which in large animals can play a role in the protection against parasites and bacterial infection. © 2018 Blackwell Verlag GmbH.

  6. Project Opalinus clay Zuercher Weinland of Nagra. Evaluation of the geo-scientific data base and of the construction engineering aspects; Projekt Opalinuston Zuercher Weinland der Nagra. Beurteilung der erdwissenschaftlichen Datengrundlagen und der bautechnischen Machbarkeit

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2005-02-15

    In this report the Commission for Nuclear Waste Management (KNE) assesses the geological and engineering aspects of the project Opalinus Clay, in which Nagra demonstrates the postclosure safety of geological disposal of spent fuel (SF), vitrified high-level wastes (HLW) and intermediate-level wastes (ILW) in a repository in the Opalinus Clay of the Zuercher Weinland in northern Switzerland. After in-depth examination of the geological database, KNE concludes that the demonstration of a suitable geological site for final disposal of SF, HLW and ILW in the Opalinus Clay of the Zuercher Weinland has been achieved. The geological assumptions Nagra uses for the assessment of long-term safety are based on data that have been carefully collected and interpreted. KNE acknowledges that Nagra interpreted the geological data correctly and adequately using state-of-the-art techniques. In case of lacking information, Nagra has used conservative or worst-case assumptions. The information documented by Nagra represents a good synthesis of field, laboratory and literature data. The tectonic situation of the Zuercher Weinland was examined in great details by Nagra. In the centre of the investigated region, where the Opalinus Clay occurs at 600 to 750 meters depth, the 3D-seismic data confirm its undisturbed stratification in an area of about 15 km{sup 2}. Analysis and interpretation of the available information on the geological evolution provides no indication that erosion would expose the confining units above the Opalinus Clay within the next million years. The Opalinus Clay in the Zuercher Weinland is quite homogeneous and about 110 m thick. The properties of this rock are examined and found to be favourable for a repository. The dominance of the fine grain size and the high clay content indicate a very low hydraulic conductivity suitable for the isolation of radioactive wastes. Pore water extracted from drill-core samples is saline and has remained trapped for millions of

  7. Interação do exercício de natação sustentada e da densidade de estocagem no desempenho e na composição corporal de juvenis de matrinxã Brycon amazonicus Sustained swimming and stocking density interaction in the performance and body composition of matrinxã Brycon amazonicus juveniles

    Directory of Open Access Journals (Sweden)

    Gustavo Alberto Arbeláez-Rojas

    2009-02-01

    Full Text Available O objetivo deste estudo foi estimar o efeito da densidade de estocagem associada ao exercício de natação moderada no desempenho e na composição corporal de juvenis de matrinxã (Brycon amazonicus. Foram utilizados peixes com comprimento e peso médio inicial de 12,3±0,5cm e 18,4±0,1g, os quais foram distribuídos ao acaso em dois grupos: o primeiro grupo de peixes foi estocado em três densidades correspondendo a 88, 176 e 353 peixes m-3 e foi condicionado a nadar a uma velocidade de 1,0cc s-1 (comprimento corporal por segundo em tanques circulares de 250L, durante 70 dias. O segundo grupo de peixes foi mantido nas mesmas densidades em água parada (sem exercício perfazendo no total seis tratamentos com três repetições. Foram estimados parâmetros de desempenho e da composição corporal, particularmente do músculo branco e do músculo vermelho de ambos os grupos. Os resultados mostraram que o exercício e a densidade afetaram significativamente o crescimento e a composição dos músculos do matrinxã. O grupo de peixes criados sob exercício moderado na densidade de 176 peixes m-3 apresentou melhor desempenho (PThe aim of the present study was to gauge the effect of stocking density associated to the sustained swimming on the performance and body composition of matrinxã (Brycon amazonicus juveniles. The fish were initially sized at 12.3±0.5cm length and 18.4g±0.1g weight. They were distributed randomly in two groups: the first was arranged into three densities of 88, 176 and 353 fish m-3 and conditioned to swim at 1.0BL sec-1 in circular tanks of 250L for 70 days; the second was arranged in the same fish densities but in static waters performing six treatments with three repetitions. Performance and body compositions were estimated in white and red muscles for both groups. The results express the growth and muscle composition change in response to the exercise and fish density. The fish maintained in moderate swimming at 176

  8. Determinação da razão ótima de espermatozóides por ovócitos de piabanha Brycon insignis (pisces - characidae Determination of the optimum ratio of spermatozoa per oocyte of the piabanha Brycon insignis

    Directory of Open Access Journals (Sweden)

    E. Shimoda

    2007-08-01

    Full Text Available Determinou-se a razão ótima de espermatozóides por ovócitos da piabanha Brycon insignis, utilizando-se dois machos e duas fêmeas da espécie, submetidos ao procedimento de desova induzida. Os gametas foram extrusados manualmente 200 horas-grau após a aplicação do extrato bruto de hipófise. Os ovócitos foram misturados e deste pool retiraram-se amostras com 2g de ovócitos (701 ovócitos/g. O sêmen do pool foi diluído em solução de NaCL 1,2% de tal forma que, após a adição de 1ml do sêmen diluído aos ovócitos, fossem obtidas as seguintes razões espermatozóides por ovócitos em cada tratamento: T1=86.662, T2=173.324, T3=259.986, T4=346.648 e T5=433.310. A taxa de fertilização do sêmen não diluído usado como controle foi de 65,3%. Após ativação espermática com NaHCO3 1% e fecundação, os ovos foram transferidos para as incubadoras e nelas foram observadas as seguintes percentagens de fertilização em relação à do grupo-controle: T1=35,7%, T2=53,1%, T3=79,1%, T4=93,4% e T5=87,8%. A percentagem de fertilização (em relação ao controle aumentou de forma linear, segundo a equação de regressão: Y=15,55+0,0002297X (PThe optimum spermatozoa:oocyte ratio of piabanha Brycon insignis was studied. Two males and two females were induced to spawn, and the gametes were stripped after 200 hourgrades starting from the application of carp pituitary gland. Oocytes from two females were mixed, and samples of 2g (701 oocytes/g were collected from the obtained pool and placed into plastic cups. The semen from the two males, after mixed to compose a pool, was diluted in NaCl solution (1.2% so that, after the addition of 1ml of diluted sperm into the oocytes, the following spermatozoa:oocyte ratios (tri-replicated were obtained: T1=86,662, T2=173,324, T3=259,986, T4=346,648 and T5=433,310. After the activation using 1% NaHCO3 and fertilization, the eggs were transferred to incubators, and observed the percentages of fertilization

  9. Time of feed transition and inclusion levels of exogenous protease in rations for piabanha-do-Pardo Brycon sp. hatchery=Momento para a transição alimentar e níveis de inclusão de protease exógena na ração da larvicultura de piabanha-do-Pardo Brycon sp.

    Directory of Open Access Journals (Sweden)

    Afonso Pelli

    2012-10-01

    Full Text Available Two experiments were conducted which consisted of determining the ideal time to make a feed transition from larvae of ‘curimba’ Prochilodus hartii to ration (from third, fifth and seventh days of life, with three days of co-feeding, and assess inclusion levels of exogenous protease (0, 0.02 and 0.2% in the diet of larvae of piabanha-do-Pardo Brycon sp., in a completely randomized experimental design and duration of 15 and 17 days, respectively. Biomass, survival, total length, weight and specific growth rate were measured at the end of the experiments. Water quality parameters were measured every three days. The different transition periods and levels of exogenous protease did not affect water quality. The animals subjected to feed transition on the seventh day of life showed better results for length (23.1 mm, weight (110.9 mg and SGR (25.5%, being similar in biomass and survival at the fifth day of life. Therefore, the transition can be made on the fifth day of life. The inclusion levels of exogenous protease in the commercial diet had no effect on performance.Foram realizados dois experimentos, que consistiram em determinar o momento ideal de se realizar a transição alimentar de larva de curimba Prochilodus hartii para ração (a partir do terceiro, quinto e sétimo dia de vida, com três dias de coalimentação, e avaliar níveis de inclusão de protease exógena (0; 0,02 e 0,2% na dieta de larvas de piabanha-do-Pardo Brycon sp., em delineamento inteiramente casualizado e duração de 15 e 17 dias, respectivamente. A biomassa, sobrevivência, comprimento total, peso médio e taxa de crescimento específico foram mensurados ao final dos experimentos. Já os parâmetros de qualidade de água foram aferidos a cada três dias. Os diferentes períodos de transição alimentar e níveis de protease exógena não interferiram na qualidade da água. Os animais submetidos à transição alimentar no sétimo dia de vida apresentaram melhores

  10. Efeito da estratégia de vida sobre as variações no conteúdo de energia de duas espécies de peixes (Brycon hilarii e Hypophthalmus edentatus, durante o ciclo reprodutivo = Effect of life strategy on the variations of energy content of two fish species (Brycon hilarii e Hypophthalmus edentatus during their reproductive cycle

    Directory of Open Access Journals (Sweden)

    Vanessa Monteiro

    2007-04-01

    Full Text Available Com o objetivo de investigar diferenças no conteúdo de energia durante o ciclo reprodutivo, foram selecionados 54 exemplares de Brycon hilarii (k-estrategista e 82 de Hypophthalmus edentatus (r-estrategista em amostragens realizadas mensalmente, entreoutubro de 2000 e março de 2004, no reservatório de Manso, Estado do Mato Grosso do Norte e em sua área de influência. Determinou-se, para cada indivíduo, o conteúdo calórico, em kcal g-1 de peso seco, com auxílio da bomba calorimétrica (Parr 1261 e, realizaram-se comparações entre os valores calóricos obtidos, o fator de condição (K e a relação gonadossomática. Observou-se que, em geral, os valores médios de K e do conteúdo calórico foram superiores nos machos das duas espécies analisadas, embora não tenham sidoidentificadas diferenças significativas entre os sexos. Constatou-se que os valores calóricos de H. edentatus foram superiores aos de B. hilarii, enquanto os valores do fator de condição foram contrários, apresentando-se superiores para B. hilarii. Diferenças significativas foram constatadas nas comparações realizadas entre o conteúdo energético e o fator de condição, de indivíduos de ambas as espécies. Enquanto B. hilarii apresentou as mais elevadas concentrações de energia nos músculos, durante o máximo desenvolvimento gonadal, emH. edentatus, isso ocorreu quando iniciava o processo de maturação gonadal. Os resultados descritos para cada espécie durante o ciclo reprodutivo permitem confirmar a hipótese de que as duas espécies de peixes, B. hilarii e H. edentatus, com diferentes estratégias de vida,acumulam e mobilizam energia de forma distinta durante o período de maturação gonadal.The aim of this work was to investigate differences in the energy content during reproductive cycle of two species of fish with different life strategies: Brycon hilarii (k-strategist and Hypophthalmus edentatus (r-strategist. Fifty-four samples of B. hilarii

  11. Avaliação de níveis protéicos para a nutrição de juvenis de matrinxã (Brycon cephalus Evaluation of dietary protein contents for juvenile matrinxã (Brycon cephalus

    Directory of Open Access Journals (Sweden)

    Antônio Cláudio Uchôa Izel

    2004-01-01

    Full Text Available O matrinxã (Brycon cephalus - Gunther, 1869, é uma espécie de peixe nativa da bacia Amazônica que tem despertado grande interesse entre pesquisadores e piscicultores de todo o Brasil. A crescente demanda pelo cultivo desta espécie em ambiente controlado se deve, principalmente, à sua pronta adaptação ao cativeiro e à aceitação de alimentos artificiais, tanto de origem vegetal quanto animal, ao lado do seu elevado valor comercial. Contudo, para ser um empreendimento comercial bem sucedido, o alimento a ser fornecido a esta espécie deve atender a suas necessidades em proteína e permitir elevados ganhos de peso em períodos curtos. O experimento foi conduzido na estação de aqüicultura da Embrapa Amazônia Ocidental. Foram testados cinco níveis de proteína bruta (16, 19, 22, 25 e 28% em dietas isocalóricas (EB = 390 kcal/100g em um delineamento experimental inteiramente casualizado com três repetições para cada tratamento. Os resultados obtidos após 210 dias de estudo mostraram que a dieta contendo 28 % de proteína bruta promoveu o maior ganho de peso, melhor conversão alimentar e mais alto crescimento corporal entre os níveis testados, indicando que este nível protéico atendeu satisfatoriamente às necessidades de proteína para esta espécie, nas condições deste experimento.Matrinxã (Brycon cephalus - Gunther, 1869 a native fish species from the Amazon basin, has been causing a great deal of interest among researchers and fish culturists all over Brazil. The rising demand for the culture of this species in controlled environment is mainly due, to its ready adaptation to captivity, the acceptance of manufactured feed made with either animal or plant ingredients, along with its high commercial value. However, for a successful commercial enterprise, feed must meet protein requirements of the fish to allow high weight gain in a short period. The experiment was carried out at Embrapa Amazônia Ocidental aquaculture

  12. Influência da primeira alimentação na larvicultura e alevinagem do yamú Brycon siebenthalae (Characidae - DOI: 10.4025/actascianimsci.v25i1.2092 First feeding influence on yamú, Brycon siebenthalae (Characidae larval rearing - DOI: 10.4025/actascianimsci.v25i1.2092

    Directory of Open Access Journals (Sweden)

    Sandra Pardo-Carrasco

    2003-04-01

    Full Text Available Para avaliar a influência da primeira alimentação na alevinagem do yamú, Brycon siebenthalae, no Instituto de Acuicultura/Universidad de Los Llanos (Villavicencio, Colômbia, foram desenvolvidos dois experimentos. No experimento 1, testaram-se, durante vinte e quatro horas, diferentes tipos de alimento vivo como primeira alimentação das pós-larvas (PL de yamú: náuplios de Artemia sp. (NA, zooplâncton silvestre (ZS e larvas de pirapitinga (LP (Piaractus brachypomus. No tratamento controle as pós-larvas foram mantidas em jejum. O alimento que proporcionou melhores resultados em ganho de peso e comprimento total foi larvas de pirapitinga (p Two experiments were carried out at Instituto de Acuicultura de Los Llanos/Universidad de Los Llanos (Villavicencio, Colômbia to evaluate first feeding influence on yamú larval rearing. In the first experiment, the following prey types were tested to first feeding for yamú larvae during 24 hours: Artemia sp. nauplii, wild zooplankton and pirapitinga (Piaractus brachypomus larvae. In the control yamú larvae were subjected to starvation. Pirapitinga larva was the prey item that offered the best results for weight and total length gain (p < 0.05. In the second experiment, yamú larvae performance was compared when stocked into fertilized ponds during 15 days either at the onset feeding or after first feeding with pirapitinga larvae prey item. Survival rate was lower in the larvae that were stocked into rearing ponds at the onset of feeding (13.4% when compared to survival of yamú larvae that were stocked after receiving pirapitinga larvae (74.1%. These results indicate that the use of pirapitinga larvae at first feeding increases performance of yamú larval rearing.

  13. A review of materials and corrosion issues regarding canisters for disposal of spent fuel and high-level waste in Opalinus clay

    International Nuclear Information System (INIS)

    Landolt, D.; Davenport, A.; Payer, J.; Shoesmith, D.

    2009-01-01

    The project 'Entsorgungsnachweis' presented by NAGRA to the Swiss Federal Government in December 2002 assessed the feasibility of disposal of spent fuel (SF), vitrified high level waste (HLW) from reprocessing and long-lived intermediate level waste in an Opalinus Clay repository site in Northern Switzerland. NAGRA proposed the use of carbon steel canisters for disposal of SF/HLW and it also put forward an alternative concept of copper canisters with cast iron insert. In its reply the Federal Government acknowledged that NAGRA had successfully demonstrated the technical feasibility of disposal of SF/HLW. However, some of its experts raised a number of questions related to the choice of steel as canister material. Among others, it was questioned whether hydrogen formed by corrosion of steel in contact with saturated bentonite might adversely affect the barrier function of the Opalinus clay. It was also recommended that alternative canister materials and/or design concepts should be evaluated. To deal with these concerns NAGRA convened an international group of experts, the Canister Materials Review Board (CMRB), who were to review the existing information on canister materials that could be suitable for the proposed repository environment. Based on present knowledge of materials science, the CMRB was to recommend to NAGRA the most suitable material(s) for meeting the performance requirements for SF/HLW canisters. Specifically, the CMRB was to consider corrosion, including hydrogen generation, and stress-assisted failure processes that could affect the integrity and projected life time of SF/HLW canisters or impede the functioning of geological barriers while keeping in mind the overall feasibility of manufacturing, sealing and inspecting the canisters. The CMRB was further asked to identify the needs and provide advice for further studies by NAGRA on the long term performance and safety of SF/HLW canisters in the Swiss repository concept. For the assessment of the

  14. Microbial investigations in Opalinus clay from Mont Terri and in Callovo-Oxfordian argillite from Meuse/Haute-Marne; Caracterisation microbiologique de l'argile a opalinus du Mont Terri et de l'argilite du callovo-oxfordien de Meuse/Haute-Marne

    Energy Technology Data Exchange (ETDEWEB)

    Poulain, S

    2006-12-15

    The subject of this Ph.D. thesis deals with research achieved in the context of the Axis 2 of the law Bataille voted on December 30, 1991 about the possibility of building a deep geological repository for medium or high activity and long living nuclear waste. Nearby such a site, some microorganisms may influence the mobility of radionuclides coming from the waste canisters. This work consisted in looking for autochthonous microorganisms in the Opalinus clay formation from Mont Terri (Switzerland) and in the Callovo-Oxfordian argillite from Meuse/Haute-Marne (France). Microbial Investigations in these unknown unperturbed environments suggested very low microbial densities in the clayey sediments. However, new bacterial species could be isolated from those samples. In addition, a part of the allochthonous population, which has been introduced by air and human activity, could be identified in the Meuse/Haute-Marne underground research laboratory. (author)

  15. Microbial investigations in Opalinus clay from Mont Terri and in Callovo-Oxfordian argillite from Meuse/Haute-Marne; Caracterisation microbiologique de l'argile a opalinus du Mont Terri et de l'argilite du callovo-oxfordien de Meuse/Haute-Marne

    Energy Technology Data Exchange (ETDEWEB)

    Poulain, S

    2006-12-15

    The subject of this Ph.D. thesis deals with research achieved in the context of the Axis 2 of the law Bataille voted on December 30, 1991 about the possibility of building a deep geological repository for medium or high activity and long living nuclear waste. Nearby such a site, some microorganisms may influence the mobility of radionuclides coming from the waste canisters. This work consisted in looking for autochthonous microorganisms in the Opalinus clay formation from Mont Terri (Switzerland) and in the Callovo-Oxfordian argillite from Meuse/Haute-Marne (France). Microbial Investigations in these unknown unperturbed environments suggested very low microbial densities in the clayey sediments. However, new bacterial species could be isolated from those samples. In addition, a part of the allochthonous population, which has been introduced by air and human activity, could be identified in the Meuse/Haute-Marne underground research laboratory. (author)

  16. Host specificity of Lepeophtheirus crassus (Wilson and Bere) (Copepoda: Caligidae) parasitic on the marlin sucker Remora osteochir (Cuvier) in the Atlantic Ocean.

    Science.gov (United States)

    Ho, Ju-shey; Collete, Bruce B; Madinabeitia, Ione

    2006-10-01

    Three species of remoras--Remora brachyptera (Lowe), Remora osteochir (Cuvier), and Remora remora (Linnaeus)--were collected from 4 species of billfishes--Istiophorus platypterus (Shaw), Makaira nigricans Lacepéde, Tetrapturus albidus Poey, and Tetrapturus pfluegeri Robins and de Sylva--on board a Japanese long-liner Shoyo Maru during her cruise in 2002 across the Atlantic. However, only the marlin sucker (R. osteochir) was found to carry a parasitic copepod, Lepeophtheirus crassus (Wilson and Bere, 1936). Although 12 species of parasitic copepods have been reported from billfishes around the world ocean, none of them is L. crassus. Thus, L. crassus is considered a parasite specific to the marlin sucker.

  17. The first finding of Asian black bear (Carnivora, Ursidae, Ursus (Euarctos) thibetanus G. Cuvier, 1823) in the Late Pleistocene of northern Eurasia.

    Science.gov (United States)

    Kosintsev, P A; Tiunov, M P; Gimranov, D O; Panov, V S

    2016-11-01

    An M1 tooth of Asian black bear (Ursus (Euarctos) thibetanus G. Cuvier, 1823) was found in deposits of the Tetyukhinskaya cave (Middle Sikhote-Alin, 44°35'N, 135°36'E). This finding is the first reliable evidence of Asian black bear's presence in Pleistocene of Primorye. Its morphological and morphometric descriptions are given. The period of inhabitation of U. (E.) thibetanus determined based on the radiocarbon date obtained during the study of the tooth, is 39 874 ± 133 BP (NSK-850, UGAMS-21786), which corresponds to the middle of Marine Isotope Stage 3 (MIS 3) of Late Pleistocene. The composition of ancient theriofauna indicates the existence of wide variety of landscapes in Primorye in the middle of Late Pleistocene. A refugium of forest fauna, in which species of taiga, nemoral, and Central Asian mountain-forest theriocomplexes were present, was located in southern Primorye in Late Pleistocene.

  18. Characterisation of gas transport properties of the Opalinus clay, a potential host rock formation for radioactive waste disposal; Caracterisation des proprietes des argiles d'Opalinus (roche d'accueil potentielle pour un stockage de dechets radioactifs) relatives au transport des gaz

    Energy Technology Data Exchange (ETDEWEB)

    Marschall, P. [Nagra - National Cooperative for the Disposal of Radioactive Waste, Wettingen (Switzerland); Horseman, S. [British Geological Survey, Kingsley Dunham Centre, Keyworth (United Kingdom); Gimmi, T. [Bern Univ. (Switzerland); Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    2005-07-01

    The Opalinus Clay in Northern Switzerland has been identified as a potential host rock formation for the disposal of radioactive waste. Comprehensive understanding of gas transport processes through this low-permeability formation forms a key issue in the assessment of repository performance. Field investigations and laboratory experiments suggest an intrinsic permeability of the Opalinus Clay in the order of 10{sup -20} to 10{sup -21} m{sup 2} and a moderate anisotropy ratio {<=} 10. Porosity depends on clay content and burial depth; values of {approx} 0.12 are reported for the region of interest. Porosimetry indicates that about 10-30% of voids can be classed as macro-pores, corresponding to an equivalent pore radius > 25 nm. The determined entry pressures are in the range of 0.4-10 MPa and exhibit a marked dependence on intrinsic permeability. Both in situ gas tests and gas permeameter tests on drill-cores demonstrate that gas transport through the rock is accompanied by pore water displacement, suggesting that classical flow concepts of immiscible displacement in porous media can be applied when the gas entry pressure (i.e. capillary threshold pressure) is less than the minimum principal stress acting within the rock. Essentially, the pore space accessible to gas flow is restricted to the network of connected macro-pores, which implies a very low degree of desaturation of the rock during the gas imbibition process. At elevated gas pressures (i.e. when gas pressure approaches the level of total stress that acts on the rock body), evidence was seen for dilatancy controlled gas transport mechanisms. Further field experiments were aimed at creating extended tensile fractures with high fracture transmissivity (hydro- or gas-fractures). The test results lead to the conclusion that gas fracturing can be largely ruled out as a risk for post-closure repository performance. (authors)

  19. Geomechanical analysis of excavation-induced rock mass behavior of faulted Opalinus clay at the Mont Terri underground rock laboratory (Switzerland)

    International Nuclear Information System (INIS)

    Thoeny, R.

    2014-01-01

    Clay rock formations are potential host rocks for deep geological disposal of nuclear waste. However, they exhibit relatively low strength and brittle failure behaviour. Construction of underground openings in clay rocks may lead to the formation of an excavation damage zone (EDZ) in the near-field area of the tunnel. This has to be taken into account during risk assessment for waste-disposal facilities. To investigate the geomechanical processes associated with the rock mass response of faulted Opalinus Clay during tunnelling, a full-scale ‘mine-by’ experiment was carried out at the Mont Terri Underground Rock Laboratory (URL) in Switzerland. In the ‘mine-by’ experiment, fracture network characteristics within the experimental section were characterized prior to and after excavation by integrating structural data from geological mapping of the excavation surfaces and from four pre- and post-excavation boreholes.The displacements and deformations in the surrounding rock mass were measured using geo-technical instrumentation including borehole inclinometers, extensometers and deflectometers, together with high-resolution geodetic displacement measurements and laser scanning measurements on the excavation surfaces. Complementary data was gathered from structural and geophysical characterization of the surrounding rock mass. Geological and geophysical techniques were used to analyse the structural and kinematic relationships between the natural and excavation-induced fracture network surrounding the ‘mine-by’ experiment. Integrating the results from seismic refraction tomography, borehole logging, and tunnel surface mapping revealed that spatial variations in fault frequency along the tunnel axis alter the rock mass deformability and strength. Failure mechanisms, orientation and frequency of excavation-induced fractures are significantly influenced by tectonic faults. On the side walls, extensional fracturing tangential to the tunnel circumference was the

  20. The geological evolution of opalinus clay in the Zurcher Weinland Area (ne Switzerland): learning from the past to predict future evolution and stability

    International Nuclear Information System (INIS)

    Gautschi, A.; Mazurek, M.

    2004-01-01

    A number of safety-relevant issues need to be addressed when considering long-term evolution of a radioactive waste repository, out of which uplift/erosion, fault activity, and changes in the geochemical and hydrogeological environment are particularly important. Among the strongest arguments in the prediction of future evolution is the extrapolation of events and processes that occurred over a long period of time in the geological past (e.g. 10 Ma) to a shorter period in the future. The future long-term evolution of Opalinus Clay in a potential siting area for a high-level waste repository in the Zurcher Weinland (NE Switzerland) is considered over a time period of around l Ma. The geological evolution or geological stability, respectively, can be predicted plausibly within reasonable limits over such a time period based on a detailed analysis of geological history. Predictions extending beyond this time period are feasible but contain an increasing element of uncertainty. This paper summarises the project-related conclusions, which are presented in greater detail in Nagra (2002a). (author)

  1. Geomechanical analysis of excavation-induced rock mass behavior of faulted Opalinus clay at the Mont Terri underground rock laboratory (Switzerland)

    Energy Technology Data Exchange (ETDEWEB)

    Thoeny, R.

    2014-07-01

    Clay rock formations are potential host rocks for deep geological disposal of nuclear waste. However, they exhibit relatively low strength and brittle failure behaviour. Construction of underground openings in clay rocks may lead to the formation of an excavation damage zone (EDZ) in the near-field area of the tunnel. This has to be taken into account during risk assessment for waste-disposal facilities. To investigate the geomechanical processes associated with the rock mass response of faulted Opalinus Clay during tunnelling, a full-scale ‘mine-by’ experiment was carried out at the Mont Terri Underground Rock Laboratory (URL) in Switzerland. In the ‘mine-by’ experiment, fracture network characteristics within the experimental section were characterized prior to and after excavation by integrating structural data from geological mapping of the excavation surfaces and from four pre- and post-excavation boreholes.The displacements and deformations in the surrounding rock mass were measured using geo-technical instrumentation including borehole inclinometers, extensometers and deflectometers, together with high-resolution geodetic displacement measurements and laser scanning measurements on the excavation surfaces. Complementary data was gathered from structural and geophysical characterization of the surrounding rock mass. Geological and geophysical techniques were used to analyse the structural and kinematic relationships between the natural and excavation-induced fracture network surrounding the ‘mine-by’ experiment. Integrating the results from seismic refraction tomography, borehole logging, and tunnel surface mapping revealed that spatial variations in fault frequency along the tunnel axis alter the rock mass deformability and strength. Failure mechanisms, orientation and frequency of excavation-induced fractures are significantly influenced by tectonic faults. On the side walls, extensional fracturing tangential to the tunnel circumference was the

  2. Efecto de la pluviosidad y el brillo solar sobre la producción y características del semen en el pez Brycon henni (Pisces:Characidae

    Directory of Open Access Journals (Sweden)

    C.J Tabares

    2006-03-01

    Full Text Available El pez Brycon henni es una especie endémica protegida por la legislación colombiana, que habita cuerpos de agua de zonas cafeteras (700-1900 m. s. n. m,comprendidas entre los 4º35’56’’ N y 74º04’51’’ W, con temperaturas que oscilan entre los 18 y los 28ºC. A pesar de las características promisorias de esta especie, su reproducción en cautiverio a nivel comercial no ha sido posible por falta de conocimientos básicos de su biología y comportamiento. El objetivo del presente trabajo fue caracterizar la producción y la fisiología espermática de machos en cautiverio. A lo largo de un año se tomaron 20 muestras de cada uno de 10 ejemplares. El semen se obtuvo mediante masaje abdominal cráneo-caudal y se transportó a 4ºC para su análisis en el laboratorio. Con excepción de septiembre y octubre que fueron los meses más lluviosos, siempre se obtuvo semen de al menos el 50% de los animales. El color, la osmolalidad y el pH fueron similares en todas las muestras a lo largo del año. El volumen, la concentración, la viabilidad, la movilidad y el tiempo de activación fueron variables: El efecto del brillo solar fue positivo sobre el volumen (Spearman pEffect of pluviosity and sun shine on sperm production and seminal characteristics of the fish Brycon henni (Pisces:Characidae. In Colombia the fish Brycon henni is a protected endemic species. It inhabits water bodies in coffee producing areas (700-1900 ma.s.l.; 4º35’56’’ N -74º04’51’’ W; 18-28°C. Insufficient knowledge of its basic biology and behavior prevent the commercial culture of this promising fish. We studied the production and sperm physiology of captive males. Along a year 20 samples were taken from each of 10 males. The sample was obtained by abdominal cefalo-caudal massage and transported to the laboratory at 4°C. Except for September and October (maximum rainfall,sperm was always obtained in at least 50% of the males. Color, osmolality and pH were

  3. Heater test in the Opalinus Clay of the Mont Terri URL. Gas release and water redistribution - Contribution to heater experiment (HE); Rock and bentonite thermo-hydro-mechanical (THM) processes in the nearfield

    International Nuclear Information System (INIS)

    Jockwer, N.; Wieczorek, K.

    2006-06-01

    Beside salt and granite, clay formations are investigated as potential host rocks for disposing radioactive waste. In Switzerland in the canton Jura close to the city of St. Ursanne, an underground laboratory was built in the vicinity of the reconnaissance gallery of a motorway tunnel. Since 1995, a consortium of 12 international organisations is running this laboratory for investigating the suitability of the Opalinus clay formation with regard to disposal of radioactive waste. In 1999, the Heater Experiment B (HE-B) was started for investigating the coupled thermo-hydro-mechanical (THM) processes of the Opalinus clay in interaction with the bentonite buffer. The principal contractors of this project were the Bundesanstalt fuer Geowissenschaften und Rohstoffe (BGR), the Empresa Nacional de Residuos Radiactivos S. A. (ENRESA), the Gesellschaft fuer Anlagen- und Reaktorsicherheit (GRS) mbH, and the National Cooperative for the Disposal of Radioactive Waste (NAGRA). GRS participated in that experiment for determining the subjects of gas generation, gas release, water content, and water redistribution in the Opalinus clay during heating. This was achieved by analysing gas and water samples from the test field before, during, and after the heating period and by performing geoelectric tomography measurements in the heated region. The in-situ measurements were supported by an additional laboratory programme. This report deals with the work of GRS performed in this project during the years 1999 to 2005. All the results obtained in the frame of the project are presented. Additional laboratory measurements conducted by the Pore Water Laboratory at CIEMAT in Madrid are also presented. The participation of GRS was funded by German Ministry of Economics and Labour (BMWA) under the contract No. 02 E 9602 and by the Commission of the European Communities under the contract No. FIKW.CT-2001-00132. (orig.)

  4. Monitoring the Excavation Damaged Zone in Opalinus clay by three dimensional reconstruction of the electrical resistivity in the Mont Terri gallery G-04

    Science.gov (United States)

    Lesparre, N.; Adler, A.; Nicollin, F.; Gibert, D.; Nussbaum, C.

    2012-04-01

    The characteristics of opalinus clay have been studied in the last years for its capacity to retain radionuclide transport as a low permeable rock. This formation presents thereby suitable properties for hosting repository sites of radioactive waste. The Mont Terri underground rock laboratory (Switzerland) has been excavated in opalinus clay layer in order to develop experiences improving the knowledge on the physico-chemical properties of the rock. The study of electrical properties furnishes information on the rock structure, its anisotropy and the changes of these properties with time (Nicollin et al., 2010 ; Thovert et al., 2011). Here the three dimensional reconstruction of the electrical resistivity aims at monitoring the temporal evolution of the excavation damaged zone. Three rings of electrodes have been set-up around the gallery and voltage is measured between two electrodes while a current is injected between two others (Gibert et al., 2006). Measurements have been achieved from July 2004 until April 2008 before, during and after the excavation of the gallery 04. In this study we develop a computational approach to reconstruct three dimensional images of the resistivity in the vicinity of the electrodes. A finite element model is used to represent the complex geometry of the gallery. The measurements inferred from a given resistivity distribution are estimated using the software EIDORS (Adler and Lionheart, 2006), this constitutes the forward problem. The reconstruction of the media resistivity is then implemented by fitting the estimated to the measured data, via the resolution of an inverse problem. The parameters of this inverse problem are defined by mapping the forward problem elements into a coarser mesh. This allows to reduce drastically the number of unknowns and so increases the robustness of the inversion. The inversion is executed with the conjugate gradient method regularised by an analysis of the Jacobian singular values. The results show an

  5. Monte Carlo simulations of GeoPET experiments: 3D images of tracer distributions (18F, 124I and 58Co) in Opalinus clay, anhydrite and quartz

    Science.gov (United States)

    Zakhnini, Abdelhamid; Kulenkampff, Johannes; Sauerzapf, Sophie; Pietrzyk, Uwe; Lippmann-Pipke, Johanna

    2013-08-01

    Understanding conservative fluid flow and reactive tracer transport in soils and rock formations requires quantitative transport visualization methods in 3D+t. After a decade of research and development we established the GeoPET as a non-destructive method with unrivalled sensitivity and selectivity, with due spatial and temporal resolution by applying Positron Emission Tomography (PET), a nuclear medicine imaging method, to dense rock material. Requirements for reaching the physical limit of image resolution of nearly 1 mm are (a) a high-resolution PET-camera, like our ClearPET scanner (Raytest), and (b) appropriate correction methods for scatter and attenuation of 511 keV—photons in the dense geological material. The latter are by far more significant in dense geological material than in human and small animal body tissue (water). Here we present data from Monte Carlo simulations (MCS) reflecting selected GeoPET experiments. The MCS consider all involved nuclear physical processes of the measurement with the ClearPET-system and allow us to quantify the sensitivity of the method and the scatter fractions in geological media as function of material (quartz, Opalinus clay and anhydrite compared to water), PET isotope (18F, 58Co and 124I), and geometric system parameters. The synthetic data sets obtained by MCS are the basis for detailed performance assessment studies allowing for image quality improvements. A scatter correction method is applied exemplarily by subtracting projections of simulated scattered coincidences from experimental data sets prior to image reconstruction with an iterative reconstruction process.

  6. Deformation mechanisms and evolution of the microstructure of gouge in the Main Fault in Opalinus Clay in the Mont Terri rock laboratory (CH)

    Science.gov (United States)

    Laurich, Ben; Urai, Janos L.; Vollmer, Christian; Nussbaum, Christophe

    2018-01-01

    We studied gouge from an upper-crustal, low-offset reverse fault in slightly overconsolidated claystone in the Mont Terri rock laboratory (Switzerland). The laboratory is designed to evaluate the suitability of the Opalinus Clay formation (OPA) to host a repository for radioactive waste. The gouge occurs in thin bands and lenses in the fault zone; it is darker in color and less fissile than the surrounding rock. It shows a matrix-based, P-foliated microfabric bordered and truncated by micrometer-thin shear zones consisting of aligned clay grains, as shown with broad-ion-beam scanning electron microscopy (BIB-SEM) and optical microscopy. Selected area electron diffraction based on transmission electron microscopy (TEM) shows evidence for randomly oriented nanometer-sized clay particles in the gouge matrix, surrounding larger elongated phyllosilicates with a strict P foliation. For the first time for the OPA, we report the occurrence of amorphous SiO2 grains within the gouge. Gouge has lower SEM-visible porosity and almost no calcite grains compared to the undeformed OPA. We present two hypotheses to explain the origin of gouge in the Main Fault: (i) authigenic generation consisting of fluid-mediated removal of calcite from the deforming OPA during shearing and (ii) clay smear consisting of mechanical smearing of calcite-poor (yet to be identified) source layers into the fault zone. Based on our data we prefer the first or a combination of both, but more work is needed to resolve this. Microstructures indicate a range of deformation mechanisms including solution-precipitation processes and a gouge that is weaker than the OPA because of the lower fraction of hard grains. For gouge, we infer a more rate-dependent frictional rheology than suggested from laboratory experiments on the undeformed OPA.

  7. Activation energies of the self-diffusion of HTO, 22Na+ and 36Cl- in a highly compacted argillaceous rock (Opalinus Clay)

    International Nuclear Information System (INIS)

    Loon, L.R. van; Mueller, W.; Iijima, K.

    2005-01-01

    The temperature dependence of the self-diffusion of HTO, 22 Na + and 36 Cl - in Opalinus Clay (OPA) was studied using a through-diffusion technique, in which the temperature was gradually increased in the steady state phase of the diffusion. The measurements were done on samples from two different geological locations. The dependence of the effective diffusion coefficient on temperature was found to be of an Arrhenius type in the temperature range between 0 and 70 deg. C. A slight difference between the two locations could be observed. The average value of the activation energy of the self-diffusion of HTO in OPA was 21.1 ± 1.6 kJ mol -1 , and 21.0 ± 3.5 and 19.4 ± 1.5 kJ mol -1 for 22 Na + and 36 Cl - , respectively. The measured values for HTO are slightly higher than the values found for the bulk liquid water (HTO: 18.8 ± 0.4 kJ mol -1 ). This indicates that the structure of the confined water in OPA might be slightly different from that of bulk liquid water. Also for Na + and Cl - , slightly higher values than in bulk liquid water (Na + : 18.4 kJ mol -1 ; Cl - : 17.4 kJ mol -1 ) were observed. The Stokes-Einstein relationship, based on the temperature dependency of the viscosity of bulk water, could not be used to describe the temperature dependence of the diffusion of HTO in OPA. This additionally indicates the slightly different structure of the pore water in OPA

  8. Hydrochemical characterisation of the opalinus clay in the test interval of the BDI-B1 borehole and on site pH, Eh, Fe(II) and alkalinity measurements

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez, A.M.; Turrero, M.J.; Yllera, A.; Melon, A.M.; Sanchez, M.D.; Pena, J.; Garralon, A.; Rivas, P. [Centro de Investigaciones Energeticas, Medioambientales y Tecnologicas (CIEMAT), Dpt. of Energy Environmental Impact, Madrid (Spain); Hernan, P. [ENRESA, Madrid (Spain)

    2005-07-01

    Clay formations are considered as a feasible option for the disposal of high-level radioactive wastes. In order to determine their suitability for this purpose, the evaluation of the hydro-geochemistry and transport mechanisms must be undertaken. In this sense, a general understanding of the basic physical and chemical processes that govern the solute transport together with a detailed site-characterization programme is required. To reach this goal, a number of activities have been developed in the Opalinus Clay formation at the Mont Terri Underground Research Laboratory (URL) at Switzerland. In the context of some experiments (WS-C, WS-D, WS-E, GM Task, DI, etc.), the Opalinus Clay formation has been comprehensively characterized to develop a conceptual, thermodynamic and transport model of solutes. The framework of these works is the need to know the mechanism of the possible migration of radionuclides and the pore water chemistry, as essential data for the performance assessment of such argillaceous systems. (authors)

  9. Isolation and characterization of eight microsatellite loci from Galeocerdo cuvier (tiger shark and cross-amplification in Carcharhinus leucas, Carcharhinus brevipinna, Carcharhinus plumbeus and Sphyrna lewini

    Directory of Open Access Journals (Sweden)

    Agathe Pirog

    2016-05-01

    Full Text Available The tiger shark Galeocerdo cuvier (Carcharhinidae is a large elasmobranch suspected to have, as other apex predators, a keystone function in marine ecosystems and is currently considered Near Threatened (Red list IUCN. Knowledge on its ecology, which is crucial to design proper conservation and management plans, is very scarce. Here we describe the isolation of eight polymorphic microsatellite loci using 454 GS-FLX Titanium pyrosequencing of enriched DNA libraries. Their characteristics were tested on a population of tiger shark (n = 101 from Reunion Island (South-Western Indian Ocean. All loci were polymorphic with a number of alleles ranging from two to eight. No null alleles were detected and no linkage disequilibrium was detected after Bonferroni correction. Observed and expected heterozygosities ranged from 0.03 to 0.76 and from 0.03 to 0.77, respectively. No locus deviated from Hardy-Weinberg equilibrium and the global FIS of the population was of 0.04NS. Some of the eight loci developed here successfully cross-amplified in the bull shark Carcharhinus leucas (one locus, the spinner shark Carcharhinus brevipinna (four loci, the sandbar shark Carcharhinus plumbeus (five loci and the scalloped hammerhead shark Sphyrna lewini (two loci. We also designed primers to amplify and sequence a mitochondrial marker, the control region. We sequenced 862 bp and found a low genetic diversity, with four polymorphic sites, a haplotype diversity of 0.15 and a nucleotide diversity of 2 × 10−4.

  10. Corrosion of carbon steel under anaerobic conditions in a repository for SF and HLW in Opalinus Clay. Technical report 08-12

    International Nuclear Information System (INIS)

    King, F.

    2008-10-01

    Nagra is considering carbon steel as one of the canister material options for the disposal of high level waste and spent fuel in a deep geological repository in Opalinus Clay. Following a brief period of aerobic conditions, the canister will be exposed to an anaerobic environment for much of its service life. Knowledge of the rate of anaerobic corrosion is important not only for estimating the canister lifetime but also for determining the rate of hydrogen generation. This report describes a critical review of the anaerobic corrosion behaviour of carbon steel under environmental conditions similar to those expected in the repository. The aims of the report are: 1. to recommend a (range of) long-term anaerobic corrosion rate(s) for carbon steel canisters, and 2. to justify the use of this rate in safety assessments based on a mechanistic understanding of the structure and properties of the protective corrosion product films. The review is based on selected studies from various national nuclear waste management programs, supplemented where appropriate with studies from other applications and with evidence from archaeological analogues. The corrosion rate of carbon steel decreases with time because of the formation of a protective surface film. There are differences in behaviour in bulk solution and in the presence of compacted bentonite. In bulk solution, the corrosion rate decreases to an apparent steady-state rate after a period of approximately six months, with a long-term rate of the order of 0.1 μm·.yr -1 . The surface film comprises a duplex structure, with a magnetite outer layer and a spinel-type inner layer. In compacted clay systems the rate of decrease in corrosion rate is slower, with steady state not being reached after several years of exposure. There is a significant body of evidence from apparently well-conducted experiments that indicate an anaerobic corrosion rate of the order of 1-2 μm·yr -1 in systems containing compacted clay and the

  11. Expertise on the provision of evidence with respect to Nagra's disposal concept for spent fuel assemblies, vitrified high-level radioactive waste as well as for long-living intermediate-level wastes (Opalinus clay project)

    International Nuclear Information System (INIS)

    2005-08-01

    Mankind has been living in a field of natural radiation; in Switzerland, the natural dose is around 3 mSv per year. It can be assumed that an artificial dose smaller than the natural one is harmless and can therefore be tolerated. However, nuclear power plants, medicine, industry and research produce radioactive wastes whose radioactivity is mostly higher than the natural level. These wastes must therefore be concentrated and enclosed until the decay reduces the dose rate to a harmless level. For this, it is foreseen that the radioactive wastes will be disposed of in deep-lying geological strata. The enclosure must be guarantied in such a way that, at any time, the radiation suffered by mankind and environment due to the radioactive wastes stays under the statutory limit of 1 mSv/a. The judgement of the quality of the deep underground repository is divided into 3 chapters: a) based on the geological and hydro-geological properties of the host rock, the proof of safety shows that the chosen repository site is safe for the long term; b) the proof of site guaranties that the repository needed can be built in the chosen host rock; c) the proof of implementation demonstrates that the repository can be built with the actual technical means proposed. The forecast for the development of the safety of the repository in the long term is fairly inaccurate, the most difficult factor being the developments in mankind's way of life. Therefore, conservative assumptions must be taken into account to cover even the most unlikely cases. The former project 'Gewaehr' presented by the National Co-operative for the Disposal of Nuclear Wastes (NAGRA) in 1978 was based on crystalline rock; it was rejected because it was not possible to find a sufficiently large area without geologic faults for the repository. In new investigations, NAGRA found a suitable layer of Opalinus clay in Zurich's Weinland. In the neighbourhood of the layer discovered, there are neither noticeable beds of other

  12. Le faune et la sirène : la situation de Cuvier dans l’économie de The Marble Faun, de Nathaniel Hawthorne

    Directory of Open Access Journals (Sweden)

    Antoine Traisnel

    2012-06-01

    Full Text Available Nathaniel Hawthorne’s The Marble Faun ends with one character’s polite refusal to satisfy the narrator’s curiosity concerning young Donatello’s possible animality. When asked if Donatello’s ears are as pointy as those of the book’s titular figure, the Faun of Praxiteles, Kenyon smiles inscrutably and responds: “On that point, at all events, there shall be no word of explanation.” On that “point” – that of Donatello’s ears—the author remains obstinately tight-lipped, having “hoped to mystify this anomalous creature between the Real and the Fantastic […] without impelling him to ask how Cuvier would have classified poor Donatello.” The disclosure of a small anatomical detail threatens to shatter the whole edifice of Hawthorne’s fiction. The point in question here, however, is not just the extremity that makes measurement possible but also the ungraspable limit (the punctum that undoes the logic of Cuvierian classification. Analyzing the metrics of The Marble Faun, my paper will query how the romance envisions the vanishing point of the human/animal relation.The Marble Faun s’achève sur le refus poli d’un personnage qui renâcle à satisfaire la curiosité du narrateur. Quand celui-ci lui demande si les oreilles du jeune Donatello sont aussi pointues que celles du Faune de Praxitèle, Kenyon sourit mystérieusement et répond : « On that point, at all events, there shall be no word of explanation. » Sur ce point, ou plutôt sur la pointe des oreilles de Donatello, l’« auteur » reste muet dans l’espoir, écrit-il, de situer cette créature aberrante « entre le réel et le fantastique » sans avoir à spécifier la place qu’elle occupe au sein de la taxonomie établie par Cuvier. La divulgation d’un petit détail anatomique menace de faire imploser l’édifice de la fiction hawthornienne. Le point en question, cependant, n’est pas simplement l’extrémité à partir de laquelle l

  13. Variabilidad de las comunidades de parásitos metazoos del róbalo Eleginops maclovinus (Cuvier & Valenciennes, 1830 (Pisces: Eleginopidae en Chile Variability of metazoan parasite communities in the rock cod Eleginops maclovinus (Cuvier & Valenciennes, 1830 (Pisces: Eleginopidae off Chile

    Directory of Open Access Journals (Sweden)

    MARIO GEORGE-NASCIMENTO

    2009-06-01

    Full Text Available La comparación de las variaciones en el tiempo cronológico y en el espacio es uno de los aspectos menos estudiados en la ecología de las comunidades de parásitos. Por eso, en este estudio se compara la abundancia total, riqueza y composición de las infracomunidades de parásitos del róbalo Eleginops maclovinus (Cuvier & Valenciennes, 1830 (Pisces: Eleginopidae, entre muestras tomadas en Chile centro-sur en tres localidades geográficas (Talcahuano, Puerto Montt y Punta Arenas, y en dos momentos del tiempo en cada una de ellas. En el conjunto de las 126 infracomunidades examinadas se encontraron 18 taxa de parásitos. La abundancia total y la composición de las infracomunidades se modificaban con la ontogenia del hospedador. Sin embargo, se encontró que la variación entre años en una localidad es de similar magnitud a la que hay entre lugares geográficos, luego de corregir por el efecto de la ontogenia del hospedador. Estos resultados resaltan la necesidad de implementar diseños de muestreo más rigurosos al momento de usar a los parásitos como marcadores biológicos de las poblaciones de hospedadores. Se propone que futuros estudios en las fuentes de variación de las comunidades de parásitos mejoren la descripción de estas variaciones con diseños de muestreo con medidas replicadas en el tiempo y el espacio.Comparison of variations in both chronological time and space is one of the least studied subjects in the ecology of parasite communities. Thus, we compared the abundance, richness and composition of parasite infracommunities in the rock cod Eleginops maclovinus (Cuvier & Valenncienes, 1830 (Pisces: Eleginopidae, between three widely separated localities along south-central Chile (Talcahuano, Puerto Montt and Punta Arenas, which were sampled in two different years each. Eighteen parasite taxa were taxonomically determined in the 126 hosts examined. Total abundance and infracommunity composition changed along host ontogeny

  14. Diffusion of HTO, {sup 36}Cl{sup -}, {sup 125}I{sup -} and {sup 22}Na{sup +} in Opalinus Clay: Effect of Confining Pressure, Sample Orientation, Sample Depth and Temperature

    Energy Technology Data Exchange (ETDEWEB)

    Van Loon, L.R.; Soler, J.M

    2004-02-01

    Effective diffusion coefficients (D{sub e}), rock capacity factors ({alpha}) and diffusion-accessible porosities ({epsilon}) were measured using the through-diffusion technique. Transport (diffusion) was measured both perpendicular and parallel to the bedding. Special cells that allowed the application of an axial confining pressure were designed. The pressures applied ranged from 1 to 5 MPa for Mont Terri samples and between 4 and 15 MPa for Benken samples, the upper values representing the in-situ confining pressure at both locations. The test solutions used in the experiments were synthetic Opalinus Clay pore water, which has Na and Cl as main components (Mont Terri: I = 0.39 M; Benken: I = 0.20 M). Pressure only had a small effect on the value of the effective diffusion coefficients. In the case of Mont Terri samples, increasing the pressure from 1 to 5 MPa resulted in a decrease of the effective diffusion coefficient of 20% for HTO, 27% for {sup 36}Cl{sup -}, 29% for {sup 125}I{sup -} and 17 % for {sup 22}Na{sup +}. In the case of Benken samples, increasing the pressure from 4 to 15 MPa resulted in a decrease of D{sub e} of 17% for HTO, 22% for {sup 36}Cl{sup -}, 32% for {sup 125}I{sup -} and 17 % for {sup 22}Na{sup +}. Moreover, the effective diffusion coefficients for for {sup 36}Cl{sup -}are smaller than for HTO, which is consistent with an effect arising from anion exclusion. This ion exclusion effect is smaller in samples from Mont Terri than in samples from Benken, which can be explained by the higher ionic strength of the Mont Terri water used in the experiments. The diffusion of {sup 22}Na{sup +} is similar to that of HTO in the case of Mont Terri OPA. For Benken OPA, the D{sub e} value of {sup 22}Na{sup +} is a factor of 2 higher than that of HTO. This last observation cannot be explained so far but is comparable to experimental data from ANDRA (1999) on Callovo-Oxfordian claystones from the Meuse/Haute Same site. {sup 125}I{sup -} is retarded with

  15. Project Opalinus Clay: Radionuclide Concentration Limits in the Near-Field of a Repository for Spent Fuel and Vitrified High-Level Waste

    Energy Technology Data Exchange (ETDEWEB)

    Berner, U

    2002-10-01

    The disposal feasibility study currently performed by Nagra includes a succession of quantitative models, aiming at describing the fate of radionuclides potentially escaping from the repository system. In this chain of models the present report provides the so called 'solubility limits' (maximum expected concentrations) for safety relevant radionuclides from SF/HLW wastes, disposed of in a reducing clay (Opalinus Clay, bentonite) environment. Solubility and speciation calculations in bentonite pore waters were performed using the very recently updated Nagra/PSI Chemical Thermodynamic Data Base (TDB) for the majority of the 37 elements addressed as potentially relevant. Particularly for the most relevant actinides, the straightforward applications with this updated TDB yielded results in contradiction to chemical analogy considerations. This was a consequence of incomplete data and called for problem specific TDB extensions, which were evaluated in a separate study. However, a summary of these problem specific extensions is provided in section 4.1. The results presented in this report solely depend on geochemical model calculations. Thus, it is of utmost importance that the underlying data and assumptions are made clear to the reader. In order to ensure traceability, all thermodynamic data not included in the Nagra/PSI TDB are explicitly specified in the report, in order to provide complete documentation for quality assurance and for comprehensibility. In order to clearly distinguish between results derived from data carefully reviewed in the Nagra/PSI TDB and those calculated from 'other' data, the summary of expected maximum concentrations provided in Table 1 includes two columns. The heading CALCULATED provides maximum concentrations based on data fully documented in the updated TDB, whereas maximum concentrations, which include additional problem specific data and/or data from other sources, are given under the heading RECOMMENDED. The

  16. Project Opalinus Clay: Radionuclide Concentration Limits in the Near-Field of a Repository for Spent Fuel and Vitrified High-Level Waste

    International Nuclear Information System (INIS)

    Berner, U.

    2002-10-01

    The disposal feasibility study currently performed by Nagra includes a succession of quantitative models, aiming at describing the fate of radionuclides potentially escaping from the repository system. In this chain of models the present report provides the so called 'solubility limits' (maximum expected concentrations) for safety relevant radionuclides from SF/HLW wastes, disposed of in a reducing clay (Opalinus Clay, bentonite) environment. Solubility and speciation calculations in bentonite pore waters were performed using the very recently updated Nagra/PSI Chemical Thermodynamic Data Base (TDB) for the majority of the 37 elements addressed as potentially relevant. Particularly for the most relevant actinides, the straightforward applications with this updated TDB yielded results in contradiction to chemical analogy considerations. This was a consequence of incomplete data and called for problem specific TDB extensions, which were evaluated in a separate study. However, a summary of these problem specific extensions is provided in section 4.1. The results presented in this report solely depend on geochemical model calculations. Thus, it is of utmost importance that the underlying data and assumptions are made clear to the reader. In order to ensure traceability, all thermodynamic data not included in the Nagra/PSI TDB are explicitly specified in the report, in order to provide complete documentation for quality assurance and for comprehensibility. In order to clearly distinguish between results derived from data carefully reviewed in the Nagra/PSI TDB and those calculated from 'other' data, the summary of expected maximum concentrations provided in Table 1 includes two columns. The heading CALCULATED provides maximum concentrations based on data fully documented in the updated TDB, whereas maximum concentrations, which include additional problem specific data and/or data from other sources, are given under the heading RECOMMENDED. The present study also pays

  17. Near Field sorption Data Bases for Compacted MX-80 Bentonite for Performance Assessment of a High-Level Radioactive Waste Repository in Opalinus Clay Host Rock

    Energy Technology Data Exchange (ETDEWEB)

    Bradbury, M.; Baeyens, B

    2003-08-01

    Bentonites of various types and compacted forms are being investigated in many countries as backfill materials in high-level radioactive waste disposal concepts. Nagra is currently considering an Opalinus clay (OPA) formation in the Zuercher Weinland as a potential location for a high-level radioactive waste repository. A compacted MX-80 bentonite is foreseen as a potential backfill material. Performance assessment studies will be performed for this site and one of the requirements for such an assessment are sorption data bases (SDB) for the bentonite near-field. The purpose of this report is to describe the procedures used to develop the SDB. One of the pre-requisites for developing a SDB is a water chemistry for the compacted bentonite porewater. For a number of reasons mentioned in the report, and discussed in more detail elsewhere, this is not a straightforward task. There are considerable uncertainties associated with the major ion concentrations and in particular with the system pH and Eh. The MX-80 SDB was developed for a reference bentonite porewater (pH = 7.25) which was calculated using the reference OPA porewater. In addition, two further SDBs are presented for porewaters calculated at pH values of 6.9 and 7.9 corresponding to lower and upper bound values calculated for the range of groundwater compositions anticipated for the OPA host rock. 'In house' sorption isotherm data were measured for Cs(I), Ni(II), Eu(III), Th(IV), Se(IV) and 1(-1) on the 'as received' MX-80 material equilibrated with a simulated porewater composition. Complementary 'in house' sorption edge and isotherm measurements on conditioned Na/Ca montmorillonites were also available for many of these radionuclides. These data formed the core of the SDB. Nevertheless, some of the required sorption data still had to be obtained from the open literature. An important part of this report is concerned with describing selection procedures and the modifications

  18. Distribuição espacial e temporal de Cetengraulis edentulus (Cuvier (Actinopterygii, Engraulidae na Baía de Sepetiba, Rio de Janeiro, Brasil Spatial and temporal distribution of Cetengraulis edentulus (Cuvier (Actinopterygii-Engraulidae in the Sepetiba Bay, Rio de Janeiro, Brazil

    Directory of Open Access Journals (Sweden)

    Márcio de Araújo Silva

    2003-12-01

    Full Text Available Anchovies are members of the Engraulidae family, characterized to present coastal pelagic habits, concentrating in large schoolings distributed among the continental shelf and semi-closed environment, like bays, where they are target of heavy fisheries. The present study aims to describe spatial and temporal distribution of Cetengraulis edentulous (Cuvier, 1828 in the Sepetiba bay (22º54'-23º04'S, 43º34'-44º10'W and to assess influences of environmental variables on fish occurrence. A monthly sampling programme was carried out between October 1998 and September 1999, to take both, fish and environmental information on temperature, salinity and depth. Three bay zones were established based on spatial gradient of salinity and depth. Adults C. edentulus were more abundant in the inner bay zone; seasonally, larger size groups (total length > 16 cm occurred in spring/summer. Significant negative correlations were found between fish abundance and salinity and depth. The close relationship of this species to innermost areas in bays, and the absence of juveniles in sandy beaches, suggest that young-of-the-year use mangrove areas as recruitment sites.

  19. Variação periódica da triiodotironina (T3 plasmática e sua ação na reprodução induzida do matrinxã, Brycon cephalus (Günther, 1869 em cativeiro Periodic variation of plasma triiodotironina (T3 and its effect on the induced reproduction of matrinxã, Brycon cephalus (Günther, 1869

    Directory of Open Access Journals (Sweden)

    Maria do Carmo Figueredo Soares

    2003-12-01

    Full Text Available O matrinxã, Brycon cephalus, espécie nativa oriunda da Bacia Amazônica, apresenta características adequadas para a piscicultura. Entretanto, trata-se de peixe reofílico, sendo necessário manejo adequado para induzir à reprodução. O objetivo deste trabalho foi caracterizar o perfil da triiodotironina (T3 plasmática no matrinxã, durante 16 meses (outubro/97 a janeiro/99, relacionando-o com a maturação sexual, além de testar a ação do T3 associado ao extrato pituitário de carpa na reprodução induzida da espécie. O experimento foi conduzido no Centro Nacional de Pesquisa de Peixes Tropicais - CEPTA, Pirassununga, SP, e no Departamento de Morfologia e Fisiologia Animal, da Faculdade de Ciências Agrárias e Veterinárias de Jaboticabal - UNESP. Foram amostrados, mensalmente, 8 a 12 peixes, de ambos os sexos, totalizando 173 animais, de onde retirou-se sangue para dosagem do T3 plasmático. As gônadas foram removidas para análise histológica com identificação do sexo e determinação do estádio de maturação. Analisaram-se testículos e ovários de 161 peixes em corte transversal, tendo predominado machos (63,35% e o estádio sexual imaturo entre ambos. A concentração plasmática de T3 foi maior de dezembro a janeiro, para machos e fêmeas, coincidindo com o período de maior atividade reprodutiva da espécie e maiores temperaturas da água. Em janeiro/99, reprodutores de matrinxã foram induzidos com extrato de pituitária de carpa (EPC associado à administração de T3 (20 mg/kg em 0,1 mL de suspensão oleosa. Os resultados sugeriram que o T3 atuou sinergicamente à gonadotropina do extrato hipofisário e que o tratamento agudo de triiodotironina com o EPC pode estimular o eixo hipotálamo-hipófise-ovário. O tempo de eclosão das larvas provenientes das fêmeas tratadas com o T3 foi menor e o crescimento inicial e a sobrevivência dessas larvas, maiores.The matrinxã, Brycon cephalus, native specie from the Amazonian

  20. Characterization of the porosity in Boom (Mol site, Belgium) and Opalinus (Mont Terri, Switzerland) clays - about the benefit of using ion beam milling tools and CRYO-SEM

    International Nuclear Information System (INIS)

    Desbois, G.; Houben, M.E.; Sholokhova, Y.; Urai, J.L.; Kukla, P.A.

    2010-01-01

    imaging of pore space at high resolution. The first of them is to use ion beam milling tools able to prepare smooth, damage free cross-sectioned surfaces. Two main ion source are available: (1) a broad ion beam (BIB, up to 3.5 mA) is suitable to produce large polished cross-sections area of few mm 2 , while the focused ion beam (FIB, 1 pA - 45 nA) is better used for fine and precise polished cross-sections area of about few μm 2 . The second alternative is to preserve the in-situ nanostructures of wet clay-stones by using cryogenic techniques in order to stabilize in-situ fluids at temperature of liquid nitrogen. A FIB/BIB-cryo- SEM instrument combines cryo-techniques to preserve wet samples, in-situ sample preparation by ion beam cross-sectioning (BIB or FIB) and observations of the stabilized microstructure at high resolution (SEM). Since the ion beam is directly embedded into the SEM, this instrument offers a unique way to get a direct access of the pore space in 3D by using a 'slice and view' procedure equivalent to nano-serial sectioning. This procedure allows us investigating the natural in-situ pore space as a 3D matrix. This contribution reports on a study of Boom and Opalinus clays from reference sites for research (respectively at Mol site, Belgium and Mont Terri, Switzerland) using cryo-SEM at cryogenic temperature, with ion beam cross-sectioning to prepare smooth, damage free surfaces. Pores commonly have crack-like tips, preferred orientation parallel to bedding and power law size distribution. We define a number of pore types depending on shape and location in the microstructure. 3-D reconstruction by serial cross-sectioning shows 3-D connectivity of the pore space and provide natural pore matrix for simulation of permeability using Lattice Boltzmann method. These findings offer a new insight into the morphology of pores and quantification of porosity down to nano-scale and provide the basis for microstructure-based models of transport in clays

  1. Dinâmica populacional, biologia reprodutiva e o ictioplâncton de Cetengraulis edentulus Cuvier (Pisces, Clupeiformes, Engraulidae na enseada do Saco dos Limões, Florianópolis, Santa Catarina, Brasil Population dynamics, reproductive biology and the ichthyoplankton of Cetengraulis edentulus Cuvier (Pisces, Clupeiformes, Engraulidae in the Saco dos Limões cove, Florianópolis, Santa Catarina, Brazil

    Directory of Open Access Journals (Sweden)

    José M. Souza-Conceição

    2005-12-01

    Full Text Available Os dados utilizados neste estudo são originários de um monitoramento ambiental realizado na enseada do Saco dos Limões, Florianópolis, Santa Catarina, Brasil. Neste monitoramento foram coletadas amostras da ictiofauna, sendo separados para análise um total de 3820 exemplares de Cetengraulis edentulus Cuvier, 1828, capturados em 17 coletas, no período compreendido entre julho de 1999 e abril de 2001. A análise dos dados permitiu estimar parâmetros populacionais e reprodutivos importantes como o comprimento de primeira maturação (118 mm para sexos grupados, 112 e 118 mm para machos e fêmeas, respectivamente, as distribuições de freqüências de comprimento, a relação peso-comprimento (Pt = 0,0000003 x Ct 3,67º8, a proporção sexual ao longo do tempo, a variação sazonal dos estádios de maturação gonadal, o índice gonadossomático, o fator de condição e o fator de condição somático, o ciclo reprodutivo e o período de desova, sendo também determinada a participação da espécie no ictioplâncton. Foram determinadas as correlações entre os parâmetros biológicos e os ambientais de temperatura e salinidade da água, superficial e de fundo. Constatou-se que a espécie utiliza o ambiente de estudo ao longo de todo seu ciclo de vida, tanto para reprodução quanto para a alimentação e o crescimento, e está estrategicamente adaptada às condições ambientais e biológicas da área de estudo.Data used in this study are from a monitoring program conducted in the Saco dos Limões cove, Florianópolis, Santa Catarina, Brazil. In this program, fish fauna were collected in 17 surveys from July 1999 to April 2001. For this study, 3820 individuals of Centengraulis edentulus Cuvier, 1828 were examined regarding population and reproductive parameters, such as, length at sexual maturity (118 mm for the combined sexes, 112 mm for males and 118 mm for females, frequency distributions for total length, length-weight relationship (Wt

  2. Effects of post-disposal gas generation in a repository for low- and intermediate-level waste sited in the Opalinus Clay of Northern Switzerland. Technical report--08-07

    International Nuclear Information System (INIS)

    2008-10-01

    In Switzerland, Opalinus Clay was proposed as a possible host rock for a repository for low- and intermediate level radioactive waste (L/ILW). This rock is characterised by a low permeability and is therefore an excellent barrier against radionuclide transport. Because significant amounts of gas are generated in the repository, a demonstration is required that despite the low gas permeability of the Opalinus Clay the gas can escape without compromising long-term safety. The present study provides a comprehensive assessment of the question how gas generation and transport in an L/ILW repository affects the system behaviour. A geological repository for L/ILW in the Opalinus Clay of Northern Switzerland with a depth of about 300-400 m below the surface was assumed. The results of model calculations were used to optimise the layout of the repository with respect to the effects of gas generation and transport. Specifically a design option was studied in which, by an appropriate choice of backfill and sealing materials, the gas can escape along the access ramp into the overlying rock formations without creating undue gas overpressures. The estimates of the gas generation rates are based on a waste inventory accounting for the existing nuclear power plants, with an assumed operation period of 50 years, and for wastes from medicine, industry and research with a collection period up to the year 2050. This inventory includes a total mass of approximately 40,000 tons of steel and other metals and about 2,200 tons of organic matter. Complete corrosion/degradation of all gas-generating materials yields a gas volume of approximately 20 to 30 million cubic meters (STP). The highest gas generation rates are expected in the early post-closure period up to several hundreds of years, followed by a steady decline. The expected total duration of the gas generation phase is in the order of 200,000 years. The total pore volume in the backfilled repository is in the order of 58,000 m 3

  3. Efeito da estratégia de vida sobre as variações no conteúdo de energia de duas espécies de peixes (Brycon hilarii e Hypophthalmus edentatus, durante o ciclo reprodutivo - DOI: 10.4025/actascibiolsci.v29i2.521 Effect of life strategy on the variations of energy content of two fish species (Brycon hilarii e Hypophthalmus edentatus during their reproductive cycle - DOI: 10.4025/actascibiolsci.v29i2.521

    Directory of Open Access Journals (Sweden)

    Evanilde Benedito

    2007-12-01

    Full Text Available Com o objetivo de investigar diferenças no conteúdo de energia durante o ciclo reprodutivo, foram selecionados 54 exemplares de Brycon hilarii (k-estrategista e 82 de Hypophthalmus edentatus (r-estrategista em amostragens realizadas mensalmente, entre outubro de 2000 e março de 2004, no reservatório de Manso, Estado do Mato Grosso do Norte e em sua área de influência. Determinou-se, para cada indivíduo, o conteúdo calórico, em kcal g-1 de peso seco, com auxílio da bomba calorimétrica (Parr 1261 e, realizaram-se comparações entre os valores calóricos obtidos, o fator de condição (K e a relação gonadossomática. Observou-se que, em geral, os valores médios de K e do conteúdo calórico foram superiores nos machos das duas espécies analisadas, embora não tenham sido identificadas diferenças significativas entre os sexos. Constatou-se que os valores calóricos de H. edentatus foram superiores aos de B. hilarii, enquanto os valores do fator de condição foram contrários, apresentando-se superiores para B. hilarii. Diferenças significativas foram constatadas nas comparações realizadas entre o conteúdo energético e o fator de condição, de indivíduos de ambas as espécies. Enquanto B. hilarii apresentou as mais elevadas concentrações de energia nos músculos, durante o máximo desenvolvimento gonadal, em H. edentatus, isso ocorreuquando iniciava o processo de maturação gonadal. Os resultados descritos para cada espécie durante o ciclo reprodutivo permitem confirmar a hipótese de que as duas espécies de peixes, B. hilarii e H. edentatus, com diferentes estratégias de vida, acumulam e mobilizam energia de forma distinta durante o período de maturação gonadal.The aim of this work was to investigate differences in the energy content during reproductive cycle of two species of fish with different life strategies: Brycon hilarii (k-strategist and Hypophthalmus edentatus (r-strategist. Fifty-four samples of B. hilarii

  4. Expertise on the provision of evidence with respect to Nagra's disposal concept for spent fuel assemblies, vitrified high-level radioactive waste as well as for long-living intermediate-level wastes (Opalinus clay project); Gutachten zum Entsorgungsnachweis der Nagra fuer abgebrannte Brennelemente, verglaste hochaktive sowie langlebige mittelaktive Abfaelle (Projekt Opalinuston)

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2005-08-15

    Mankind has been living in a field of natural radiation; in Switzerland, the natural dose is around 3 mSv per year. It can be assumed that an artificial dose smaller than the natural one is harmless and can therefore be tolerated. However, nuclear power plants, medicine, industry and research produce radioactive wastes whose radioactivity is mostly higher than the natural level. These wastes must therefore be concentrated and enclosed until the decay reduces the dose rate to a harmless level. For this, it is foreseen that the radioactive wastes will be disposed of in deep-lying geological strata. The enclosure must be guarantied in such a way that, at any time, the radiation suffered by mankind and environment due to the radioactive wastes stays under the statutory limit of 1 mSv/a. The judgement of the quality of the deep underground repository is divided into 3 chapters: a) based on the geological and hydro-geological properties of the host rock, the proof of safety shows that the chosen repository site is safe for the long term; b) the proof of site guaranties that the repository needed can be built in the chosen host rock; c) the proof of implementation demonstrates that the repository can be built with the actual technical means proposed. The forecast for the development of the safety of the repository in the long term is fairly inaccurate, the most difficult factor being the developments in mankind's way of life. Therefore, conservative assumptions must be taken into account to cover even the most unlikely cases. The former project 'Gewaehr' presented by the National Co-operative for the Disposal of Nuclear Wastes (NAGRA) in 1978 was based on crystalline rock; it was rejected because it was not possible to find a sufficiently large area without geologic faults for the repository. In new investigations, NAGRA found a suitable layer of Opalinus clay in Zurich's Weinland. In the neighbourhood of the layer discovered, there are neither

  5. Geophysical monitoring of the EDZ during a gallery excavation in the Opalinus clay of the Mont Terri URL: anomalies of noble gases and self-potential associated with fractures and fluid dynamics in a horizontal borehole

    International Nuclear Information System (INIS)

    Maineult, A.; Mahiouz, K.; Lesparre, N.; Thomas, B.; Lavielle, B.; Nussbaum, C.; Wieczorek, K.; Gibert, D.; Kergosien, B.; Nicollin, F.

    2012-01-01

    Document available in extended abstract form only. The research underground rock laboratory (URL) of Mont Terri (Switzerland) was established in 1996 in a Mesozoic clay-stone formation (Opalinus Clay). It is aimed at studying the hydro-mechanical, thermal, geochemical and geophysical behaviour of argillaceous formations in the context of radioactive waste disposal. The EZ-G experiments were designed to monitor the EDZ evolution. The EZ-G08 experiment started in September 2007 to study the EDZ changes at different time scales during the tunnelling of gallery Ga08 starting from the northern part of the URL toward the end-face of the gallery Ga04. Before the excavation process started, we characterized the petrology and the structural properties of the core of the horizontal, 12-m long borehole BEZ-G5 drilled in the end-face of gallery Ga04 (first 2 meters in the shaly facies, the rest in the sandy facies). We quantified its noble gas content for studying gas transport processes in rocks and connected fracture networks. Depletion in He can be observed in the EDZ and other noble gases can also increase as desaturation processes occur. Inflows of water occurred in the borehole few weeks after its drilling until the junction of galleries Ga08 and Ga04. Water amounts of few litres were commonly released in other boreholes in the URL. We recorded the natural electrical potentials (self-potentials - SP), in BEZ-G5. SP originate from the movement of fluid, the diffusion of concentration or temperature gradients, and are sensitive to any change occurring in them. Borehole BEZ-G5 was equipped with a specific device, on which custom-made electrodes were fixed every 15 cm. The signals showed coherent perturbations during the drilling operations in the boreholes BEZ-G12 and in the end-face of the gallery Ga04. Afterwards, an early, strong but rather smooth increase of a few tens of mV, followed by a very slow decrease of much smallest amplitude, can be observed in some signals

  6. Mode d'exploitation et durabilité de la pêche de Oreochromis niloticus (Linnaeus, 1758, Clarias gariepinus (Burchell, 1822 et Gymnarchus niloticus (Cuvier, 1829 dans le lac de barrage du Sourou (Burkina Faso

    Directory of Open Access Journals (Sweden)

    Dialla, Z.

    2016-01-01

    Full Text Available Mode of Operation and Sustainability of Oreochromis niloticus (Linnaeus, 1758, Clarias gariepinus (Burchell, 1822 and Gymnarchus niloticus (Cuvier, 1829 Fisheries in the Sourou Dam Lake (Burkina Faso. This research on fishery exploitation in the Sourou dam raises the issue of sustainable management of common property. The central hypothesis is that the effectiveness of co-management for sustainable fishing practices is related to the level of ownership of that management and actors' games by fishing communities. In analysing co-management induced effects on fishing practices and exploitation of C. gariepinus, O. niloticus and G. niloticus species, related to its implementation in Sourou fishery, a research methodology that combines qualitative and quantitative methods is used. Socio-economic surveys were conducted with 30 fishermen in three villages bordering the fishery. Biological surveys were also conducted with catches of C. gariepinus, O. niloticus and G. niloticus of these fishermen,. The results indicate a weak ownership of the co-management model by fishermen and the strategies of actors that consist to minimize the costs of the sustainable management of fisheries resources at individual level. Indeed, even when informed of fisheries regulations, fishermen use prohibited fishing equipment (54.1% of the catches of studied species, and fishi illegally (43.3% of the fishermen. Furthermore, significant proportions of each studied species are captured before their first maturity sizes (52.2% of C. gariepinus, 15.8% of G. niloticus and 14.3% of O. niloticus. So, the central hypothesis is verified because the weak ownership of co-management by fishing communities and the actors' strategies do not encourage them to develop a responsible behavior for sustainable fishing.

  7. Biogeochemical processes in a clay formation in situ experiment: Part A - Overview, experimental design and water data of an experiment in the Opalinus Clay at the Mont Terri Underground Research Laboratory, Switzerland

    Energy Technology Data Exchange (ETDEWEB)

    Wersin, P., E-mail: paul.wersin@gruner.ch [NAGRA, Hardstrasse 73, 5430 Wettingen (Switzerland)] [Gruner Ltd., Gellertstrasse 55, 4020 Basel (Switzerland); Leupin, O.X. [NAGRA, Hardstrasse 73, 5430 Wettingen (Switzerland); Mettler, S. [NAGRA, Hardstrasse 73, 5430 Wettingen (Switzerland)] [Solexperts Ltd., Mettlenbachstrasse 25, 8617 Moenchaltorf (Switzerland); Gaucher, E.C. [BRGM, 3 avenue Claude Guillemin, B.P. 36009, 45060 Orleans Cedex 2 (France); Maeder, U. [University of Bern, Institute of Geological Sciences, Baltzerstrasse 3, CH-3012 Bern (Switzerland); De Canniere, P. [SCK.CEN, Waste and Disposal Project, Boeretang 200, 2400 Mol (Belgium); Vinsot, A. [ANDRA, Laboratoire de Recherche Souterrain de Meuse/Haute-Marne, RD960 BP9, 55290 Bure (France); Gaebler, H.E. [BGR, Stilleweg 2, 30655 Hannover (Germany); Kunimaro, T. [JAEA, Tokai-mura, Naka-gun, Ibaraki 319-1195 (Japan); Kiho, K. [CRIEPI, 1646 Abiko, Abiko-city Chiba 270-1194 (Japan); Eichinger, L. [Hydroisotop, 85301 Schweitenkirchen (Germany)

    2011-06-15

    Highlights: > The composition was affected by the complex interplay of diffusion, mineral and surface reactions. > The {sup 13}C signals for carbon species showed significant variations which could only be partly explained. > The main cations remained remarkably constant during the experiment. > This underlines the strong buffering via cation exchange and carbonate dissolution/precipitation. - Abstract: An in situ test in the Opalinus Clay formation, termed porewater chemistry (PC) experiment, was carried out for a period of 5 years. It was based on the concept of diffusive equilibration whereby a traced water with a composition close to that expected in the formation was continuously circulated and monitored in a packed-off borehole. The main original focus was to obtain reliable data on the pH/pCO{sub 2} conditions of the porewater, but because of unexpected microbiologically-induced redox reactions, the objective was extended to elucidate the biogeochemical processes occurring in the borehole and to understand their impact on pH/pCO{sub 2} and porewater chemistry in the low permeability clay formation. The behaviour of the conservative tracers {sup 2}H and Br{sup -} could be explained by diffusive dilution in the clay and moreover the results showed that diffusive equilibration between the borehole water and the formation occurred within about 3 year's time. However, the composition and pH/pCO{sub 2} conditions differed considerably from those of the in situ porewater. Thus, pH was lower and pCO{sub 2} was higher than indicated by complementary laboratory investigations. The noted differences are explained by microbiologically-induced redox reactions occurring in the borehole and in the interfacial wall area which were caused by an organic source released from the equipment material. The degradation of this source was accompanied by sulfate reduction and - to a lesser extent - by methane generation, which induced a high rate of acetogenic reactions

  8. Biogeochemical processes in a clay formation in situ experiment: Part A - Overview, experimental design and water data of an experiment in the Opalinus Clay at the Mont Terri Underground Research Laboratory, Switzerland

    International Nuclear Information System (INIS)

    Wersin, P.; Leupin, O.X.; Mettler, S.; Gaucher, E.C.; Maeder, U.; De Canniere, P.; Vinsot, A.; Gaebler, H.E.; Kunimaro, T.; Kiho, K.; Eichinger, L.

    2011-01-01

    Highlights: → The composition was affected by the complex interplay of diffusion, mineral and surface reactions. → The 13 C signals for carbon species showed significant variations which could only be partly explained. → The main cations remained remarkably constant during the experiment. → This underlines the strong buffering via cation exchange and carbonate dissolution/precipitation. - Abstract: An in situ test in the Opalinus Clay formation, termed porewater chemistry (PC) experiment, was carried out for a period of 5 years. It was based on the concept of diffusive equilibration whereby a traced water with a composition close to that expected in the formation was continuously circulated and monitored in a packed-off borehole. The main original focus was to obtain reliable data on the pH/pCO 2 conditions of the porewater, but because of unexpected microbiologically-induced redox reactions, the objective was extended to elucidate the biogeochemical processes occurring in the borehole and to understand their impact on pH/pCO 2 and porewater chemistry in the low permeability clay formation. The behaviour of the conservative tracers 2 H and Br - could be explained by diffusive dilution in the clay and moreover the results showed that diffusive equilibration between the borehole water and the formation occurred within about 3 year's time. However, the composition and pH/pCO 2 conditions differed considerably from those of the in situ porewater. Thus, pH was lower and pCO 2 was higher than indicated by complementary laboratory investigations. The noted differences are explained by microbiologically-induced redox reactions occurring in the borehole and in the interfacial wall area which were caused by an organic source released from the equipment material. The degradation of this source was accompanied by sulfate reduction and - to a lesser extent - by methane generation, which induced a high rate of acetogenic reactions corresponding to very high acetate

  9. Geology of Northwestern Switzerland - with special emphasis on Opalinus Clay

    International Nuclear Information System (INIS)

    Burkhard, M.

    2007-01-01

    This report describes the variations of the geological structures of Northwestern Switzerland during about the last 200 million years. This gives an explanation for the present partition of the different rock layers in the studied domain. The geology of Switzerland is dominated by the formation of the Alps. The Mont Terri geology is best explained within the framework of the tectonic Wilson cycle: assembly of Pangea in Late Paleozoic times culminating in the Variscan orogeny, collapse and decay of this earlier mountain chain, peneplanation and new rifting leading to the opening of the alpine Tethys Ocean during the Mesozoic, followed by plate convergence, subduction, collision and new mountain-building in the Neogene. The Mont Terri geology bears witness to the same suite of events as the Alps; tectonically speaking, Mont Terri is part of the Alps. Africa continues to push Apulia against the larger European plate and the question arises as to what the geological future has in store for our hills and mountains. Recent GPS (Global Positioning System) data Iead to believe that it will be just erosion and decay

  10. Diversidad genética de piracanjuba usada en programas de repoblación con marcadores microsatélites Genetic diversity of piracanjuba used in stock enhancement programs with microsatellite markers

    Directory of Open Access Journals (Sweden)

    Maria del Pilar Rodriguez-Rodriguez

    2010-01-01

    Full Text Available El objetivo de este trabajo fue estimar la diversidad genética de un lote de Brycon orbignyanus usado en programas de repoblación, a través de marcadores microsatélites. Se analizaron muestras de 44 reproductores, de 70 larvas y de 69 alevinos, con la amplificación de cinco loci descritos para Brycon opalinus. El número de alelos, la heterozigosidad observada (Ho y esperada (He, el índice de Shannon (IS, la diversidad genética de Nei (DGN, el coeficiente de endogamia (Fis, la distancia (DG e identidad genética (IG, el número efectivo de alelos, el test del equilibrio de Hardy-Weinberg (EHW y el desequilibrio de ligación fueron calculados. Reproductores y progenie tuvieron un número similar de alelos en los loci evaluados. La Ho media, IS, DGN, DG e IG mostraron que existe menor distancia genética entre parentales y larvas y una disminución de variabilidad genética en los alevinos. Fueron observados desvíos en EHW y desequilibrio de ligación en seis pares de loci. El Fis mostró exceso de heterocigotos en parentales y larvas y déficit de heterocigotos en los alevinos. El lote de reproductores está en proceso de pérdida de alelos y hubo disminución de la variabilidad genética entre la fase de larva y alevino.The objective of this work was to estimate the genetic diversity of a Brycon orbignyanus lot used in stock enhancement programs, using microsatellite markers. Samples of 44 broodstocks, 70 larvae and 69 fingerlings, were analyzed with amplification of five loci described for Brycon opalinus. The number of alleles, the observed (Ho and expected (He heterozygosity, Shannon index (IS, Nei's genetic diversity (DGN, the inbreeding coefficient (Fis, distance (DG and genetic identity (IG, the effective number of alleles, the test of Hardy-Weinberg equilibrium (EHW and the linkage disequilibrium were calculated. Broodstocks and offspring had a similar number of alleles at the tested loci. Ho average, IS, DGN, DG and IG showed

  11. Fish farming of native species in Colombia: current situation and perspectives

    DEFF Research Database (Denmark)

    Cruz-Casallas, P. E.; Medina-Robles, V. M.; Velasco-Santamaria, Y. M.

    2011-01-01

    . The Colombian pisciculture is based on red Tilapia Oreochromis sp. (Linnaeus), Rainbow trout Oncorhynchus mykiss (Walbaum) and cachama blanca Piaractus brachypomus (Cuvier), which currently represent around 96% of the total national production. The remaining 4% comes from other farmed species such as bocachico......In Colombia and the rest of the world, the decrease in capture fisheries production has turned the aquaculture into an alternative source of protein for the populations food security as well as an important productive activity, generating employment and income for the rural communities...... Prochilodus magdalenae (Steindachner), carp Cyprinus carpio (Linnaeus) and yamu Brycon amazonicus (Spix & Agassiz). From the three main fish species, cachama blanca is the only native species, which has shown excellent performance in pond farming due to its rusticity, omnivorous habits, docility, meat quality...

  12. Notes on the diet of Pterogymnus laniarius (Cuvier)

    African Journals Online (AJOL)

    dentatus, Octopus sp. and Chlamys tincta are associated with reefs, it is clear that the most important prey are found on soft substrates. These include Macoma sp., Goneplax angulata; Mursia cristimanus and Dictenophiura anoidea. In a study of the diet of P. laniarius taken by trawlers in the. Eastern Cape, Hecht (1976) also ...

  13. Life history of the steentjie Spondyliosoma emarginatum (Cuvier ...

    African Journals Online (AJOL)

    Morphometric measurements and fin spine and ray counts, external colouration, macroscopic gonad stage and diet were recorded for steentjie Spondyliosoma emarginatum (Pisces: Sparidae) collected from Langebaan Lagoon between August 2004 and September 2005. Sagittal otoliths were removed, and age estimates ...

  14. Population Parameters of Blainvilles and Cuviers Beaked Whales

    Science.gov (United States)

    2015-09-30

    cetacean populations. Long-term monitoring of beaked whale populations in El Hierro , a nearly pristine habitat far from areas of sonar testing or...marine industry, enables valuable studies of demographic trends and life history dictated mainly by natural parameters. El Hierro is in process of...functioning (expected in 2018-2019), it is essential to continue monitoring the populations in El Hierro to obtain an uninterrupted long-term dataset of

  15. Reproductive biology of common octopus Octopus vulgaris (Cuvier ...

    African Journals Online (AJOL)

    Western Indian Ocean Journal of Marine Science. Journal Home · ABOUT THIS JOURNAL · Advanced Search · Current Issue · Archives · Journal Home > Vol 13, No 1 (2014) >. Log in or Register to get access to full text downloads.

  16. Reproductive biology of common octopus Octopus vulgaris (Cuvier ...

    African Journals Online (AJOL)

    Abstract. Although common octopus catches are increasing globally, lack of information on the species reproductive biology has been a major concern in its management particularly in Kenya. The present study aimed at investigating the reproductive biology of Octopus vulgaris from Shimoni and Vanga in the Kenyan South ...

  17. Aspects Of The Biology Of Heterotis niloticus Cuvier 1829 ...

    African Journals Online (AJOL)

    Studies on some aspects of the biology of Heterots nilotcus in Anambra river were carried out for 22 months. Analysis of the stomach content of 546 species of H. niloticus in Anambra river established the preponderance o plantivorous crustacean, copepods and cladocera throughout the four maturation stages examined.

  18. Cross-amplification of heterologous microsatellite markers in Rhamdia quelen and Leporinus elongatus

    Directory of Open Access Journals (Sweden)

    Nelson Mauricio Lopera-Barrero

    2016-02-01

    Full Text Available Native fish species in Brazil are an asset in fish farming, but their natural stocks have been significantly reduced in recent years. To mitigate this negative impact, studies on fish conservation are being conducted and genetic tools for the discrimination of population parameters are increasingly achieving great importance. Current analysis evaluates a set of microsatellite heterologous primers in the jundiá (Rhamdia quelen and in the piapara (Leporinus elongatus. Samples from the caudal fin of 15 broodstock from each species were analyzed. DNA extraction was performed with NaCl protocol and the integrity of the extracted DNA was checked with agarose gel 1%. Twenty primers developed for Piaractus mesopotamicus, Colossoma macropomum, Prochilodus lineatus, Brycon opalinus and Oreochromis niloticus were evaluated. Cross amplification of four primers of the B. opalinus and P. lineatus species (BoM12, Pli43 and Pli60 in R. quelen and BoM2, Pli43 and Pli60 in L. elongatus was assessed. Primers of P. mesopotamicus, C. macropomum and O. niloticus showed no cross amplification in the two species analyzed. Results revealed the possibility of using the four amplified heterologous primers in genetic studies for R. quelen and L. elongatus.

  19. Optimization of Artificial Propagation in Piracanjuba Fish Brycon orbignyanus Using Cryopreserved Semen.

    Science.gov (United States)

    Felizardo, V O; Melo, C C V; Murgas, L D S; Andrade, E S; Navarro, R D; Ftreitas, T F

    BACKGROUND: Cryopreserved semen could facilitate procedures during the artificial reproduction in fish. Factors affecting cryopreservation efficiency are important to define efficient protocols. This study investigated the application of cryoprotectants on the quality of piracanjuba fish semen, the sperm concentration required for oocyte fertilization and spermatic activation. We evaluated two intracellular cryoprotectant solutions (DMSO and methanol) and two extracellular cryoprotectant solutions (egg yolk and lactose) to cryopreserved piracanjuba semen. Sperm motility rate, motility duration and spermatic alterations were assessed. The protocol for piracanjuba semen cryopreservation can use solutions including either DMSO or methanol as intracellular cryoprotectant and egg yolk or lactose as extracellular cryoprotectants.

  20. Environmental degradation of Opalinus Clay with cyclic variations in relative humidity

    Science.gov (United States)

    Wild, Katrin; Walter, Patric; Madonna, Claudio; Amann, Florian

    2016-04-01

    Clay shales are considered as favorable host rocks for nuclear waste repositories due to their low permeability, high sorption capacity and the potential for self-sealing. However, the favorable characteristics of the rock mass may change during tunnel excavation. Excavation is accompanied by stress redistribution and the development of an excavation damage zone. Furthermore, unloading and exposure to atmospheric conditions with a lower relative humidity (RH) causes desaturation of the rock mass close to the tunnel. This leads to shrinkage and the formation of desiccation cracks. During the open drift stage, seasonal atmospheric changes, especially RH variations, may alter the rock mass and influence the long-term crack evolution. This contribution discusses the influence of RH variation on the mechanical behavior of OPA. A series of specimens were exposed to short-term and long-term, stepwise cyclic RH variations between about 60 and 95% at constant temperature. Strains were measured using strain gauges to monitor the volumetric response during RH cycles. After each applied RH cycle, Brazilian tensile strength (BTS) tests were performed to identify whether there is a change in tensile strength due to environmental damage caused by the change in RH. Swelling and shrinkage of the specimens accompanied by irreversible volumetric expansion was observed as a consequence of the exposure to RH cycles. However, the irreversible strain was limited to the direction normal to bedding suggesting that internal damage is restricted along the bedding planes. No significant effect of cyclic RH variations on the BTS of the specimens was observed. The strength parallel to bedding remained constant over several cycles while the strength normal to bedding shows a slightly decreasing trend after 2 cycles. Furthermore, the water retention characteristics of the specimens were not altered significantly during stepwise RH cycling as the evolution of the water content was reversible throughout the cycles. For the RH variation used, the results suggest that the long-term crack evolution around excavations in OPA is not expected to be significantly influenced by environmental degradation but dominated by other processes such as consolidation and creep.

  1. pH-dependent Pu interaction of one bacterial isolate from Mont Terri Opalinus Clay

    Energy Technology Data Exchange (ETDEWEB)

    Moll, Henry; Cherkouk, Andrea [Helmholtz-Zentrum Dresden-Rossendorf e.V., Dresden (Germany). Div. Biogeochemistry

    2016-07-01

    Sporomusa sp. MT-2.99 cells displayed a strong pH dependent affinity for Pu. Relatively high maximal Pu loadings as for instance 230 mgPu/g{sub dry} {sub biomass} for Sporomusa sp. at pH 6.1 were achieved. A much slower abiotic reduction of Pu(VI) was observed at pH 4 compared to pH 6.1. Independent on pH an enrichment of Pu(V) in the supernatant and of Pu(IV)- polymers on the biomass was discovered.

  2. Addendum to: Derivation of in situ opalinus clay porewater compositions from experimental and geochemical modelling studies

    International Nuclear Information System (INIS)

    Bradbury, M.H.; Baeyens; Pearson, F.J.; Berner, U.

    1998-01-01

    As part of the synthesis of water chemistry studies within the hydrochemical program at Mont Terri (Switzerland), a reexamination of the modelling method showed that it should lead to a range of water compositions rather than to a single composition. The single composition resulted from two compensating oversights, a theoretical one and a modelling one. These are discussed in this Addendum. (author)

  3. Engineered barrier emplacement experiment in Opalinus clay for the disposal of radioactive waste in underground repositories

    International Nuclear Information System (INIS)

    Mayor, J. C.; Garcia-Sineriz, J. L.; Alonso, E.; Alheid, H. J.; Blumbling, P.

    2005-01-01

    The EB project aims at demonstrating the technical feasibility and studying the behaviour of near field components of a high level radioactive waste repository in clay rock. The project consists of an in situ test, a series of complementary laboratory tests as well as modelling work. The project is coordinated by ENRESA (Spain) and the work is being executed by the following organizations: AITEMIN and UPC-DIT (Spain) NAGRA (Switzerland) BGR (Germany) The project is co-funded by the European Commission (contract FIKW-CT-2000-00017) and by the Swiss Federal Office for Education and Science. This report includes a synthesized description of the project from its conception until approximately one and a half years after completion of the installation of the large-scale test (October 2000 to November 30, 2003). The project is described in detail in a series of specific reports. Chapter 9, References, includes the titles of these reports. Although each participating group wrote the sections on their particular work, this report is the result of the technical review, and editing carried out by M. Velasco and J. Farias (Technical Secretariat, ST) under the direction of J.C. Mayor (Project Director, ENRESA). In addition to this preface, and the following executive summary, the report is structured on the basis of nine chapters, the general contents of which are indicated below. Chapter 1 describes, in general terms, the different parts of the project, as well as the justification, objectives, expected results, and anticipated uncertainties. This chapter has been written by the ST, but the ideas are those of all the participating groups. Chapter 2 refers to the in situ test, describing the different test components and systems. Exception is made of the Granular Bentonite Material (GBM), which is described in Chapter 3, and of the geophysical systems for the seismic and electric characterization of near field of the clay rock, which are described in Chapter 4. Chapter 3 is exclusively devoted to the GBM: fabrication, emplacement equipments, and hydraulic, mechanical and geophysical (seismic) characterization in conventional laboratory. Chapter 4 refers to the excavation of the experimental drift, and to the geophysical (seismic, electric) and hydrogeological characterization of the near field of the clay rock. Chapter 5 is devoted to the installation of the different in situ test components, systems and instruments. The experimental in situ test results and interpretation is presented in Chapter 6, while their modelling and interpretation is presented in Chapter 7. Chapter 8 includes an assessment of the experiment results and overall conclusions, in relation to the declared project objectives. Chapter 9 consists of a list of references. Although a large number of bibliographic references have been used in this project, each included in the corresponding specific reports, the only references included herein are the specific reports detailing the various tasks performed to date, plus a few other reports considered to be essential. (Author)

  4. Engineered barrier emplacement experiment in opalinus clay for the disposal of radioactive waste in underground repositories

    International Nuclear Information System (INIS)

    Mayor, J. C.; Garcia-Sineriz, J. L.; Alonso, E.; Alheid, H. J.; Blumbling, P.

    2005-01-01

    The EB project aims at demonstrating the technical feasibility and studying the behaviour of near field components of a high level radioactive waste repository in clay rock. The project consists of an in situ test, a series of complementary laboratory tests as well as modelling work. The project is coordinated by ENRESA (Spain) and the work is being executed by the following organizations:AITEMIN and UPC-DIT (Spain) NAGRA (Switzerland) BGR (Germany) The project is co-funded by the European Commission (contract FIKW-CT-2000-00017) and by the Swiss Federal Office for Education and Science. This report includes a synthesized description of the project from its conception until approximately one and a half years after completion of the installation of the large-scale test (October 2000 to November 30, 2003). The project is described in detail in a series of specific reports. Chapter 9, References, includes the titles of these reports. Although each participating group wrote the sections on their particular work, this report is the result of the technical review, and editing carried out by M. Velasco and J. Farias (Technical Secretariat, ST) under the direction of J.C. Mayor (Project Director, ENRESA). In addition to this preface, and the following executive summary, the report is structured on the basis of nine chapters, the general contents of which are indicated below. Chapter 1 describes, in general terms, the different parts of the project, as well as the justification, objectives, expected results, and anticipated uncertainties. This chapter has been written by the ST, but the ideas are those of all the participating groups. Chapter 2 refers to the in situ test, describing the different test components and systems. Exception is made of the Granular Bentonite Material (GBM), which is described in Chapter 3, and of the geophysical systems for the seismic and electric characterization of near field of the clay rock, which are described in Chapter 4. Chapter 3 is exclusively devoted to the GBM: fabrication, emplacement equipments, and hydraulic, mechanical and geophysical (seismic) characterization in conventional laboratory. Chapter 4 refers to the excavation of the experimental drift, and to the geophysical (seismic, electric) and hydrogeological characterization of the near field of the clay rock. Chapter 5 is devoted to the installation of the different in situ test components, systems and instruments. The experimental in situ test results and interpretation is presented in Chapter 6, while their modelling and interpretation is presented in Chapter 7. Chapter 8 includes an assessment of the experiment results and overall conclusions, in relation to the declared project objectives. Chapter 9 consists of a list of references. Although a large number of bibliographic references have been used in this project, each included in the corresponding specific reports, the only references included herein are the specific reports detailing the various tasks performed to date, plus a few other reports considered to be essential. (Author)

  5. Project Opalinus Clay: Radionuclide Concentration Limits in the Cementitious Near-Field of an ILW Repository

    International Nuclear Information System (INIS)

    Berner, U.

    2003-05-01

    The disposal feasibility study currently performed by Nagra includes a succession of quantitative models, aiming at describing the fate of radionuclides potentially escaping from the repository system. In this chain of models the present report provides the so called 'solubility limits' (maximum expected concentrations) for safety relevant radionuclides from ILW wastes, disposed of in a chemically reducing, cementitious environment. From a chemical point of view, the pore waters of hydrated cement matrices provide an exceptional environment. Compared with usual ground waters exhibiting pH-values of around 8, cement pore waters are strongly alkaline with pH-values from 12.5 to 13.5 and contain nearly no carbonate and only little sulfate. Oxides and hydroxides mainly determine solubility and speciation of the elements. Solubility and speciation calculations in cementitious pore waters were performed using the very recently updated Nagra/PSI Chemical Thermodynamic Data Base (TDB) for the majority of the 36 elements addressed as potentially relevant. Wherever possible, maximum concentrations compiled in this report were based on geochemical calculations. In order to ensure full traceability, all thermodynamic data not included in the TDB are explicitly specified in the document. For similar reasons the compilation of results (Table 1) clearly distinguishes between calculated and recommended items. The heading 'CALCULATED' lists maximum concentrations based on data fully documented in the TDB; results under the heading 'RECOMMENDED' include data from other sources. The pH sensitivity of the results was examined by performing calculations at pH 13.4, in accordance with the pH of non-altered cement pore water. Solubility increases predominantly for elements that tend to form anionic hydroxide complexes (Sn, Pd, Zr, Ni, Eu, Cd, Mo, Co). Oxidizing conditions around +350 mV might be expected in the environment of nitrate-containing wastes. In this case, significant solubility increases were calculated for U, Np, Pu, Se and Ag. Special attention is allocated to the uncertainties of the evaluated maximum concentrations, expressed as upper- and lower limits. The conceptual steps to determine these uncertainties are explained in the section 3. Due to lack of data, it was not always possible to assess uncertainties in a manner consistent with that used to assess the solubility limits. For some elements, uncertainties had to be derived from less sharply defined data or even with the help of estimates. Such less rigorous approaches are justified by the fact that in performance assessments particularly the upper limits are as important as are the maximum concentrations themselves. However, appropriate information was available to define an upper limit for nearly all of the relevant nuclides. (author)

  6. Project Opalinus Clay: Radionuclide Concentration Limits in the Cementitious Near-Field of an ILW Repository

    Energy Technology Data Exchange (ETDEWEB)

    Berner, U

    2003-05-01

    The disposal feasibility study currently performed by Nagra includes a succession of quantitative models, aiming at describing the fate of radionuclides potentially escaping from the repository system. In this chain of models the present report provides the so called 'solubility limits' (maximum expected concentrations) for safety relevant radionuclides from ILW wastes, disposed of in a chemically reducing, cementitious environment. From a chemical point of view, the pore waters of hydrated cement matrices provide an exceptional environment. Compared with usual ground waters exhibiting pH-values of around 8, cement pore waters are strongly alkaline with pH-values from 12.5 to 13.5 and contain nearly no carbonate and only little sulfate. Oxides and hydroxides mainly determine solubility and speciation of the elements. Solubility and speciation calculations in cementitious pore waters were performed using the very recently updated Nagra/PSI Chemical Thermodynamic Data Base (TDB) for the majority of the 36 elements addressed as potentially relevant. Wherever possible, maximum concentrations compiled in this report were based on geochemical calculations. In order to ensure full traceability, all thermodynamic data not included in the TDB are explicitly specified in the document. For similar reasons the compilation of results (Table 1) clearly distinguishes between calculated and recommended items. The heading 'CALCULATED' lists maximum concentrations based on data fully documented in the TDB; results under the heading 'RECOMMENDED' include data from other sources. The pH sensitivity of the results was examined by performing calculations at pH 13.4, in accordance with the pH of non-altered cement pore water. Solubility increases predominantly for elements that tend to form anionic hydroxide complexes (Sn, Pd, Zr, Ni, Eu, Cd, Mo, Co). Oxidizing conditions around +350 mV might be expected in the environment of nitrate-containing wastes. In this case, significant solubility increases were calculated for U, Np, Pu, Se and Ag. Special attention is allocated to the uncertainties of the evaluated maximum concentrations, expressed as upper- and lower limits. The conceptual steps to determine these uncertainties are explained in the section 3. Due to lack of data, it was not always possible to assess uncertainties in a manner consistent with that used to assess the solubility limits. For some elements, uncertainties had to be derived from less sharply defined data or even with the help of estimates. Such less rigorous approaches are justified by the fact that in performance assessments particularly the upper limits are as important as are the maximum concentrations themselves. However, appropriate information was available to define an upper limit for nearly all of the relevant nuclides. (author)

  7. Desenvolvimento gonadal de fêmeas de matrinxã, Brycon amazonicus, submetidas a restrição alimentar Gonadal development of matrinxã, Brycon amazonicus, females submitted to feed restriction

    Directory of Open Access Journals (Sweden)

    Antonio Cleber da Silva Camargo

    2008-08-01

    Full Text Available O presente estudo avaliou o efeito de ciclos de restrição alimentar e realimentação (2/3 dias, aplicados durante seis meses antes da desova, no desenvolvimento gonadal de matrinxã. Na ocasião da desova, fêmeas alimentadas diariamente e submetidas ao regime alimentar experimental, selecionadas para a indução hormonal, foram sacrificadas para retirada das gônadas e do fígado, com os quais se calculou o IGS (índice gonadossomático e o IHS (índice hepatossomático, sendo os ovários processados para análise histológica. Não houve alteração no peso relativo dos ovários e fígado, e o desenvolvimento gonadal não foi afetado pelo esquema alimentar. Os valores de IGS foram de 5,09±4,98% e 9,79±4,17% e os de IHS foram de 0,84±0,07% e 0,91±0,11%, para as fêmeas controle e experimentais, respectivamente, sem diferenças significativas entre os grupos. Os ovários de peixes dos dois grupos apresentaram as mesmas características do estádio maduro, com predominância de ovócitos na fase final de maturação, repletos de vitelo. O estudo indica que a restrição alimentar não afetou a preparação das fêmeas para a reprodução e que ciclos adequados de restrição e realimentação poderão ser aplicados na criação do matrinxã, assegurando menores custos de produção.The present study evaluated the effect of cycles of feed restriction and refeeding (2/3 days during 6 months before the spawning on the gonadal development of matrinxã. At the spawning time, females selected to hormonal induction were killed for gonad and liver removal and GSI (gonadosomatic index and HSI (hepatosomatic index were calculated. Ovaries were processed for histological analysis. The feeding regime did not alter GSI and HSI and the gonadal development. The values of GSI were 5.09±4.98% and 9.79±4.17%, and of HSI were 0.84±0.07% and 0.91±0.11%, in control and experimental females, respectively, without significant difference between groups. Ovaries from both fish groups showed the same charachteristics of the mature stage, with predominance of oocytes in the final phase of maturation, presenting large amount of yolk. The study indicates that the feed restriction did not affect the matrinxã ability to reproduction and that cycles of feed restriction and refeeding can be used in matrinxã farming leading to lower production costs.

  8. Clove oil as anaesthetic for juveniles of matrinxã Brycon cephalus (Gunther, 1869 Óleo de cravo como anestésico para juvenis de matrinxã Brycon cephalus (Gunther, 1869

    Directory of Open Access Journals (Sweden)

    Luis Antônio Kioshi Aoki Inoue

    2003-10-01

    Full Text Available Many chemicals have been used as anaesthetics in fish farms and fish biology laboratories to keep the fish immobilized during handling procedures and to prevent accidents and animal stress. In Brazil, tricaine methane sulfonate (MS 222, quinaldine sulfate, benzocaine, and phenoxyethanol are the most common fish anaesthetics used to prevent fish stress during handling, but many side effects such as body and gill irritations, corneal damage and general risks of intoxication have been reported. Clove oil is a natural product proposed as an alternative fish anaesthetic by many researchers and it has been used in many countries with great economic advantages and no apparent toxic properties. In this work, we assessed the suitability of clove oil to anaesthetize matrinxã. Sixty-three juveniles of matrinxã were exposed to seven anaesthetic batches of clove oil (pharmaceutical grade namely 18, 20, 30, 40, 50, 60, and 70 mg/L. The times to reach total loss of equilibrium and to recover the upright position were measured. Clove oil concentration about 40 mg/L was enough to anaesthetize the fish in approximately one minute and the recovery time was independent in regard to anaesthetic concentration.Diversos produtos químicos têm sido empregados como anestésicos para peixes nas estações de piscicultura e laboratórios de biologia de peixes para a devida imobilização dos organismos, afim de se prevenir acidentes e ferimentos na superfície do corpo dos próprios peixes, que podem ficar susceptíveis a patógenos e taxas altas de mortalidade. A tricaina metano sulfonato (MS 222, a quinaldina, a benzocaina e o phenoxyethanol têm sido amplamente utilizados no Brasil, mas alguns efeitos colaterais são observados como perda de muco, irritação nas brânquias e olhos, e também alguns incômodos aos trabalhadores como a necessidade do uso de luvas. Dessa forma, o óleo de cravo é proposto como um anestésico alternativo por ser um produto natural de custo acessível e sem riscos aparentes de intoxicações. No presente trabalho estudamos a possibilidade do uso do óleo de cravo como anestésico para juvenis de matrinxã, utilizando-se 63 peixes, expondo-os a banhos anestésicos nas concentrações de 18, 20, 30, 40, 50, 60 e 60 mg/L, de forma que foram mensurados os tempos necessários para que os peixes atingissem a perda total de equilíbrio e a incapacidade de retornar a posição normal de nado. A concentração de 40 mg/L foi suficiente para anestesiar juvenis de matrinxã em aproximadamente 1 minuto, sendo a recuperação independente da concentração do anestésico.

  9. Estudo dos vestígios de peixes dos sítios arqueológicos da área de influência da Usina Hidrelétrica Machadinho, Rio Grande do Sul, Brasil A study of fish traces taken from the archaeological sites of the areas surrounding the Machadinho Hydroelectric power station, Rio Grande do Sul, Brazil

    Directory of Open Access Journals (Sweden)

    Cláudio Ricken

    2009-09-01

    Full Text Available The analysis of the material obtained in the rescue of archaeological sites in the area surrounding the Hydroelectric Plant of Machadinho, Rio Grande do Sul, revealed that a considerable amount of bones and fish scales incorporated in the alimentary remains. Using an osteological collection as reference, we identified remains of Salminus brasiliensis (Cuvier, 1816 (Characidae, Brycon orbignyanus (Valenciennes, 1849 (Characidae, Pogonopoma obscurum Quevedo & Reis, 2002 (Loricariidae, Hemiancistrus fuliginosus Cardoso & Malabarba, 1999, Prochilodus lineatus (Valenciennes, 1836 (Prochilodontidae, Schizodon sp. (Anostomidae, Leporinus sp. (Anostomidae, Hoplias sp. (Erythrinidae, Hypostomus sp. (Loricariidae and Crenicichla sp. (Cichlidae. Based on specimens from fish collections, regressions were obtained comparing the size of the pre-maxillary bone in Crenicichla spp. and the length of the pectoral fin spine of Hemiancistrus fuliginosus, Pogonopoma obscurum and Hypostomus spp, with the standard length and weight of corresponding specimens. The estimated size and weight of the specimens obtained from fish remains in the archaeological sites varied between 79.7-153.9 mm and 13.5-33.9 g for Hemiancistrus fuliginosus, 158.2-151.0 mm and 179.5-194.3 g for Pogonopoma obscurum, 117.1-166.2 mm and 86.6-93.1 g for Crenicichla spp., and 62.2-397.2 mm and 34-20.3 g for Hypostomus spp. Therefore using these estimates of standard lengths and weights it was possible to formulate a hypotheses on the fishing technology used by the inhabitants of these sites.

  10. Standardization of 2-phenoxyethanol as anesthetic for juvenile Brycon cephalus (Gunther, 1869: the use in field procedures

    Directory of Open Access Journals (Sweden)

    Inoue Luis Antônio Kioshi Aoki

    2004-01-01

    Full Text Available Hyper motility is a negative factor in fish handling procedures due to the risks of damages to the animals. Chemicals are widely used to anesthetize fish during biometry and many other handling procedures. 2-Phenoxyethanol is largely employed, but many studies are necessary about tropical fish responses. The present research evaluated the anesthesia induction time for juvenile matrinxã submitted to eight different levels of 2-phenoxyethanol. The range of 2-phenoxyethanol concentration was 250-600mg liter-1. Induction time of anesthesia decreased as a function of 2-phenoxyethanol concentrations. Fish were safely anesthetized approximately after one minute of exposure to 2-phenoxyethanol batches in concentrations above 400mg/liter, and the recover period was about one minute for all anesthetic concentrations. 2-Phenoxyethanol is a safe anesthetic for juvenile matrinxã even in exposures up to 600mg liter-1 being recommended for many field procedures of fish handling.

  11. Aloe vera bathing improved physical and humoral protection in breeding stock after induced spawning in matrinxã (Brycon amazonicus).

    Science.gov (United States)

    Zanuzzo, Fábio S; Zaiden, Sérgio F; Senhorini, José A; Marzocchi-Machado, Cleni M; Urbinati, Elisabeth C

    2015-07-01

    In this study, we show that induced spawning causes stress, an intense loss of epithelia and immunosuppression, decreasing physical and humoral protection in fish, effects that were prevented or improved in fish bathed with Aloe vera. A. vera has several medicinal properties, including wound healing and immunostimulatory effects, which we observed in this study. Fish bathed with A. vera had a higher number of epidermal goblet cells and, in general, an improved wound healing rate compared with the control after induced spawning. These effects might be related to (1) the stimulation of leukocyte activity, represented here by the increased leukocyte respiratory activity triggered by A. vera (leukocytes are recognized as playing an important role in wound repair); (2) the antimicrobial properties of A. vera, which decrease wound infection and accelerate the healing process; and (3) several mechanisms that explain the healing effect of A. vera (increased collagen synthesis, rate of epithelialization, and anti-inflammatory and moisturizing effects). Our results also suggest that caution is necessary during the induced spawning process, especially during stripping, and A. vera bathing is recommended after intensive aquaculture operations. Copyright © 2015 Elsevier Ltd. All rights reserved.

  12. A new species of iguana Brachylophus Cuvier 1829 (Sauria: Iguania: Iguanidae) from Gau Island, Fiji Islands.

    Science.gov (United States)

    Fisher, Robert N; Niukula, Jone; Watling, Dick; Harlow, Peter S

    2017-06-06

    The south Pacific iguanas (Brachylophus) currently have three recognized living species in Fiji.  Recent surveys have uncovered more specific variation (morphological and genetic) within the genus and have better defined the geographic ranges of the named species.  One of these recent discoveries is a strikingly different iguana from all other island populations in Fiji which is restricted to Gau Island of the Lomaiviti Province.  Gau is the fifth largest island in Fiji and maintains excellent upland forests in the higher elevations.  We describe this population from Gau Island as a new species, Brachylophus gau sp. nov., in recognition of its type locality.

  13. A new species of iguana Brachylophus Cuvier 1829 (Sauria: Iguania: Iguanidae) from Gau Island, Fiji Islands

    Science.gov (United States)

    Fisher, Robert N.; Niukula, Jone; Watling, Dick; Harlow, Peter S.

    2017-01-01

    The south Pacific iguanas (Brachylophus) currently have three recognized living species in Fiji.  Recent surveys have uncovered more specific variation (morphological and genetic) within the genus and have better defined the geographic ranges of the named species.  One of these recent discoveries is a strikingly different iguana from all other island populations in Fiji which is restricted to Gau Island of the Lomaiviti Province.  Gau is the fifth largest island in Fiji and maintains excellent upland forests in the higher elevations.  We describe this population from Gau Island as a new species, Brachylophus gau sp. nov., in recognition of its type locality.

  14. Distribution and size of the mojarra Diapterus rhombeus (Cuvier (Actinopterygii, Gerreidae in a Southeastern Brazilian bay

    Directory of Open Access Journals (Sweden)

    Marcus Rodrigues da Costa

    2012-06-01

    Full Text Available Diapterus rhombeus is one of the most abundant fish species in the Sepetiba bay, which is a 520 km² semi-closed coastal area in Southeastern Brazil. The size and distribution of this species have been described in order to assess the use of the area as a rearing ground in both spatial and temporal (seasonal dimensions. A fish sampling program was conducted monthly by using an otter trawl between October 1998 and September 1999, in three bay zones (outer, middle and inner, defined according to depth and salinity gradient. Highly significant differences were found for CPUEs (number and biomass among seasons and zones. Size ranged from 50 to 230 mm TL, and three size-groups were defined according to a maturation scale (n = 1435: 1 - immature ( 100 mm TL. Immature and L50 individuals were more abundant (number and biomass during Autumn in the inner zone, while adults (L100 predominated during Summer in the outer zone. Evidences of movements of young-of-the-year (50-90 mm TL individuals from the inner to the outer zone were detected as they reach larger sizes (180 mm TL in the second year of life. Condition (k was higher in larger sized individuals in the outer zone during Spring, when they are apt to start the reproductive process. Two cohorts were detected according to modal progression: the first (smaller size showing faster growth than the second, evidencing a slower growth rate as they reach larger size. Distinct size classes occupying different bay zones suggest that the age-groups optimize their coexistence by partitioning the available resources, avoiding intra-specific competition.Diapterus rhombeus é uma das espécies de peixes mais abundantes na Baia de Sepetiba, ambiente costeiro de 520 km² de área semifechada no sudoeste do Brasil. O tamanho e distribuição dos indivíduos desta espécie foram descritos com o objetivo de determinar o uso das áreas de criação numa dimensão espacial e temporal (sazonal. Um programa de amostragem de arrasto de fundo foi conduzido mensalmente entre outubro 1998 a setembro 1999, em três zonas da baía (externa, central, interna, definidas através de gradientes de profundidade e salinidade. Diferenças altamente significativas foram encontradas para CPUEs (número e biomassa entre estações do ano e zonas. O comprimento variou de 50 a 230 mm CT. Três grupos de tamanhos foram definidos de acordo com uma escala de maturação gonadal (n = 1435: 1 - imaturo ( 100 mm CT. Imaturos e indivíduos L50 foram abundantes (número e biomassa durante o outono na zona interna, enquanto adultos (L100 predominaram durante o verão na zona externa. Evidências de movimento de indivíduos jovens (50-90 mm CT da zona interna para zona externa foram detectadas conforme os animais foram atingindo maiores tamanhos (180 mm CT, no segundo ano de vida. A condição (k aumentou em indivíduos maiores na zona externa durante a primavera, quando estes se tornam aptos a iniciar o processo reprodutivo. Duas coortes foram detectadas de acordo com a progressão modal: a primeira (menores tamanhos mostrando crescimento mais rápido do que a segunda, evidenciando uma taxa menor de crescimento a medida que atingem maiores tamanhos. Diferentes classes de comprimento ocupando diferentes zonas da baía sugerem que grupos de idades otimizam sua coexistência compartilhando os recursos disponíveis e evitando competição intra-especifica.

  15. Distribution and size of the mojarra Diapterus rhombeus (Cuvier) (Actinopterygii, Gerreidae) in a Southeastern Brazilian bay

    OpenAIRE

    Costa,Marcus Rodrigues da; Albieri,Rafael Jardim; Neves,Leonardo Mitrano; Santos,Alex Braz Lacone; Araujo,Francisco Gerson

    2012-01-01

    Diapterus rhombeus is one of the most abundant fish species in the Sepetiba bay, which is a 520 km² semi-closed coastal area in Southeastern Brazil. The size and distribution of this species have been described in order to assess the use of the area as a rearing ground in both spatial and temporal (seasonal) dimensions. A fish sampling program was conducted monthly by using an otter trawl between October 1998 and September 1999, in three bay zones (outer, middle and inner), defined according ...

  16. Genetic and morphological variations in the Indian mackerel Rastrelliger kanagurta (Cuvier 1817) from the Goa region

    Digital Repository Service at National Institute of Oceanography (India)

    Menezes, M.R.; Naik, S.; Martins, M.

    stream_size 9 stream_content_type text/plain stream_name Proc_Indian_Acad_Sci_(Anim_Sci)_99_457.pdf.txt stream_source_info Proc_Indian_Acad_Sci_(Anim_Sci)_99_457.pdf.txt Content-Encoding ISO-8859-1 Content-Type text/plain; charset...

  17. Den ecology of Octopus vulgaris Cuvier, 1797, on soft sediment: availability and types of shelter

    Directory of Open Access Journals (Sweden)

    Stelios Katsanevakis

    2004-03-01

    Full Text Available To avoid predation, octopuses select and actively modify shelters (also called dens in the substratum, where they remain most of the time, especially during daylight hours. The main questions that this study deals with are: Is den availability a significant constraint for the distribution of Octopus vulgaris on soft sediment? What kind of dens does O. vulgaris use on soft sediment and what factors affect the selection of one type instead of another? With population density measurements by SCUBA diving and enrichment experiments with artificial dens, we concluded that the availability of solid materials necessary for den construction is a limiting factor for the distribution of O. vulgaris on soft sediment. O. vulgaris used four different types of den on soft sediment: well (a vertical hole in the sediment, rock/stone (the octopus uses a rock or a large stone to dig a cavity under it, shell (an empty shell is used, human origin (a solid material of human origin is used. The relative proportion of the four types of den in the areas studied was: 38.7% human origin, 29.7% well, 21.5% rock/stone, 2.9% shell. Also, 7.3% of the octopuses were found outside their den. The main types of den were found in different relative proportions in relation to the depth, the distance from shore, the octopus size and the granulometry of the sediment.

  18. Worldwide Population Structure in Cuvier’s Beaked Whales: Identification of Units for Conservation

    Science.gov (United States)

    2008-09-01

    Kitchener, Royal Museum of Scotland, Edinburgh, UK; V. Martin, Sociedad para el Estudio de los Cetaceos en el Archipelago Canario (SECAC), Lanzarote, Canary...some delays in setting up the UNSW School of BEES Ancient DNA Laboratory (part of the Molecular Ecology and Evolution Facility; MEEF). These...Flores, University of Valparaiso, Chile; C. Olavarria, Fundación Centro de Estudios del Cuaternario Fuego-Patagonia y Antártica (INACH), Chile; J. L

  19. Morphologic characterisation and elemental distribution of Octopus vulgaris Cuvier, 1797 vestigial shell

    International Nuclear Information System (INIS)

    Napoleao, P.; Reis, C. Sousa; Alves, L.C.; Pinheiro, T.

    2005-01-01

    The elemental composition of mineral structures in marine organisms can provide useful information to reconstruct environmental histories of individuals and distinguish populations or stocks. In cephalopods, as Octopus vulgaris, morpho-physiological description of vestigial shells may contribute to a better understanding of the physiology, of the process involved in the increment growth and may eventually provide important and useful tools for the validation of age determination methods. Nuclear microprobe analysis was used to map chemical elements in O. vulgaris vestigial shell. The maps contain elemental and morphological information, and enabled especially through Cl and Ca distributions to classify bands of concentric rings. The levels of P, Ca and Sr decrease from central region to external rings, while those of S and Cl showed an inverse tendency. Enhanced concentrations of Fe, Cu and Zn were found in external rings, and no significant variations were detected in the K and Br contents. The results indicate that three regions can be established on the basis of the elemental contents distributions. Specially, the P and Ca variability can distinguish rings from central and external regions. The differential incorporation of elements in the vestigial shell observed may reflect environmental and physiological factors that are affecting the life cycle of this species

  20. Functional integrity of Colossoma macropomum (Cuvier, 1816 sperm cryopreserved with enriched extender solutions

    Directory of Open Access Journals (Sweden)

    Raycon Roberto Freitas Garcia

    Full Text Available Cryoprotectant solutions are used to protect the sperm from alterations caused by the low temperature in the cryopreservation process. We evaluated the quality of Colossoma macropomum semen after freezing, using dimethyl sulfoxide (DMSO as a cryoprotectant, combined with two extender solutions (T1 - Solution 1: Glucose 90.0 g/L, Sodium Citrate 6.0 g/L, EDTA 1.5 g/L, Sodium Bicarbonate 1.5 g/L, Potassium Chloride 0.8 g/L, Gentamycin Sulphate 0.2 g/L, and T2 - Solution 2: Glucose 90.0 g/L, ACP(r-104 10.0 g/L. Motility rate and motility time did not differ between T1 and T2 and were lower than fresh semen. The number of normal sperm was significantly different in treatments T1 (15.1% and T2 (21.9%, and both showed a reduction in the percentage of normal sperm compared to fresh semen (57.4%. The values found for the rates of fertilization and hatching, mitochondrial functionality and sperm DNA, did not differ between the treatments (T1 and T2. Regarding membrane integrity, there was a higher percentage of spermatozoa with intact membranes in T1 (53.4% than T2 (43.7%. The extender solutions, combined with 10% DMSO, maintained the sperm DNA intact in almost all the C. macropomum sperm cells, however there was a loss in their functionality.

  1. DINAMIKA EKOLOGI LAUT SULAWESI (WPP 716 SEBAGAI DAYA DUKUNG TERHADAP PERIKANAN MALALUGIS (Decapterus macarellus Cuvier, 1833

    Directory of Open Access Journals (Sweden)

    Puji Rahmadi

    2015-06-01

    Full Text Available Ikan Malalugis adalah ikan pelagis kecil yang merupakan hasil tangkapan utama nelayan di perairan Laut Sulawesi. Pada tahun 2012 dilaporkan bahwa perikanan pelagis kecil menjadi salah satu hasil perikanan yang penting, dan hasil tangkapan yang dominan dari perikanan pelagis kecil tersebut adalah ikan malalugis biru (Decapterus macarellus. Jenis ikan malalugis memiliki sifat bermigrasi dan membentuk gerombolan kecil yang mana sangat dipengaruhi oleh kondisi lingkungannya. Tipe arus pasut di Teluk Manado (Laut Sulawesi merupakan arus pasut bolak balik (reversing current. Banyaknya arus yang begitu aktif merupakan salah satu faktor yang mendukung habitat ikan malalugis. Diduga kekhasan sifat distribusi arus di daerah laut Sulawesi ini yang membuat kelimpahan ikan malalugis relatif tinggi di perairan Sulawesi Utara dibandingkan dengan daerah perairan lainnya di Indonesia. Kelimpahan ikan malalugis yang tinggi mendorong ikan ini menjadi komoditas penting dalam sektor perikanan di Laut Sulawesi. Meski demikian pada tahun 2012 dilaporkan bahwa tingkat produksi ikan malalugis mengalami penurunan. Hal ini diduga karena terlalu tingginya tingkat eksploitasi atau diakibatkan oleh adanya perubahan dalam kondisi ekosistem ikan tersebut di Laut Sulawesi. Oleh karena itu studi ini dilakukan untuk mengkaji tingkat daya dukung lingkungan terhadap keberlangsungan sumberdaya perikanan malalugis di wilayah perairan Laut Sulawesi. Malalugis fish is a small pelagic fish that constitute the main catch of fishermen in the waters of North Celebes Sea. In 2012 it was reported that small pelagic fishery became one of the important fishery products and it was dominated by the species of Malalugis (Decapterus macarellus. This species has a typical behavior which was highly mobility and forming fish schooling and strongly influenced by environmental conditions. The type of tidal current in North Sulawesi coast is reversing current. This kind of current could make a very active current in the water which is suitable for the habitat of Malalugis. This distinctiveness of current was considered as a trigger for relatively high abundance of Malalugis in this area compared to its abundance in other water body of Indonesian territory. In 2012, total catch of this species has been reported to be decreased; thismay caused by either high level of exploitation nor changing on its habitat or even both. This study was conducted to investigate the capability of ecosystem and habitat of Malalugis to support its sustainability.

  2. Reproductive biology of Cetengraulis edentulus (Cuvier, 1829, the major fishery resource in Guanabara Bay, Brazil

    Directory of Open Access Journals (Sweden)

    Ana Clara Sampaio Franco

    Full Text Available Cetengraulis edentulus is a broadely distributed engraulid in Southwest Atlantic, currently accounting for the main fish species commercially exploited at Guanabara Bay, Brazil. This study aimed to extend the knowledge on reproduction of C. edentulus at Guanabara Bay and to test whether some descriptors of reproductive activity, especially the gonadosomatic index (GSI, and the index of reproductive activity (IRA changed among seasons. A total of 978 C. edentulus specimens were retrieved from purse seine commercial landings at Conservas Rubi S.A. company, in São Gonçalo city, RJ. Subsamples of 90-120 individuals were collected from bimonthly yields between July 2010 (winter and June 2011 (autumn. Most fish were adults (120-170 mm TL, in response to the high selectivity of commercial fisheries. All descriptors indicated a broad spawning period (late winter to spring, peaking in November, suggesting this is the critical period to protect C. edentulus stocks from overfishing at Guanabara Bay. Fecundity averaged 12,720 oocytes and was positively related to fish size, GSI and fullness index, indicating that preserving larger individuals (TL > 160 mm could contribute significantly to the reproductive success of C. edentulus, since they produce more oocytes. Cetengraulis edentulus é um engraulídeo amplamente distribuído no Atlântico Sudoeste, sendo um importante recurso comercialmente explorado na baía de Guanabara, Brasil. O presente estudo teve como objetivo ampliar o conhecimento sobre a reprodução de C. edentulus na baía de Guanabara e testar quais descritores da atividade reprodutiva, especialmente o índice gonadossomático (IGS e o índice de atividade reprodutiva (IAR se modificaram ao longo das estações do ano. Um total de 978 indivíduos de C. edentulus foram capturados pelo método de rede de cerco da frota comercial no cais da empresa Conservas Rubi S.A., na cidade de São Gonçalo, RJ. Subamostras de 90-120 indivíduos de C. edentulus foram coletados bimestralmente durante o período de julho de 2010 (inverno e junho de 2011 (outono. A maioria dos indivíduos foram adultos (120-170 mm CT, em resposta a alta seletividade das capturas comerciais. Todos os índices indicaram um amplo período reprodutivo (final do inverno e primavera, com pico em novembro, sugerindo que este seria um período crítico para preservar os estoques de C. edentulusda sobrepesca na baía de Guanabara. A fecundidade média foi de 12720 ovócitos e foi positivamente relacionada com tamanho do peixe, IGS e índice de repleção, indicando que preservar maiores indivíduos (CT > 160 mm poderia contribuir significativamente para o sucesso reprodutivo de C. edentulusna área, visto que esses indivíduos produzem um maior número de ovócitos.

  3. Morphological study of the pineal gland of (crab eater raccoon Procyon cancrivorus (Cuvier, 1798

    Directory of Open Access Journals (Sweden)

    Leandro de Oliveira Marques

    2010-06-01

    Full Text Available The Procyon cancrivorus is a wild carnivore that is widely distributed and relatively common, but it remains little studied, and few works report on the biology of this species. The aim of this work was to characterize morphologically the pineal gland of Procyon cancrivorus through macro, microscopic and radiographic studies, and to compare them with those from other animals. In this work, four adult animals of both sexes were used, originating from the Scientific Herd of CECRIMPAS IBAMA (Process nº 02027.003731/04-76. Macroscopically, the pineal gland of Procyon cancrivorus was located between the occipital lobes of the cerebral hemispheres, cranially to the vermis cerebelar. It was positioned rostrally to the rostral colliculus and caudally to the habenular comissure. Microscopically, the gland was covered externally by a capsule deriving from the meningeal pia mater. The presence of three types of cells was noted in the glandular parenchyma: pinealocytes, glial cells and mast cells. No calcareous concretions in the pineal gland were found in the radiographic and microscopic studies.

  4. Paleoclimate determines diversification patterns in the fossorial snake family Uropeltidae Cuvier, 1829.

    Science.gov (United States)

    Cyriac, Vivek Philip; Kodandaramaiah, Ullasa

    2017-11-01

    Understanding how and why diversification rates vary across evolutionary time is central to understanding how biodiversity is generated and maintained. Recent mathematical models that allow estimation of diversification rates across time from reconstructed phylogenies have enabled us to make inferences on how biodiversity copes with environmental change. Here, we explore patterns of temporal diversification in Uropeltidae, a diverse fossorial snake family. We generate a time-calibrated phylogenetic hypothesis for Uropeltidae and show a significant correlation between diversification rate and paleotemperature during the Cenozoic. We show that the temporal diversification pattern of this group is punctuated by one rate shift event with a decrease in diversification and turnover rate between ca. 11Ma to present, but there is no strong support for mass extinction events. The analysis indicates higher turnover during periods of drastic climatic fluctuations and reduced diversification rates associated with contraction and fragmentation of forest habitats during the late Miocene. Our study highlights the influence of environmental fluctuations on diversification rates in fossorial taxa such as uropeltids, and raises conservation concerns related to present rate of climate change. Copyright © 2017 Elsevier Inc. All rights reserved.

  5. Stratégie de Reproduction du Carangidae Trachinotus teraia Cuvier ...

    African Journals Online (AJOL)

    user

    La reproduction de Trachinotus teraia a été étudiée dans la lagune Ebrié au cours de campagnes mensuelles pendant deux années consécutives (février 2004 à janvier 2006). Cette étude se situe dans le cadre d'acquisition de connaissances sur la biologie de Trachinotus teraia en vue d'évaluer son potentiel aquacole.

  6. A Population Consequence of Acoustic Disturbance Model for Cuviers beaked whale (Ziphius cavirostris) in Southern California

    Science.gov (United States)

    2015-09-30

    two sources. The energetics model that will underpin both PCoD models for Md and Zc has also been published (New et al 2013). The full PCoD model...to Zc on SCORE. We will also be able to use the simplified PCoD model for beaked whales currently being developed under the ONR-funded project...34Using an interim PCoD protocol to assess the effects of disturbance associated with US Navy exercises on marine mammal populations”. This project will

  7. The first description of oarfish Regalecus glesne (Regalecus russellii Cuvier 1816) ageing structures

    Science.gov (United States)

    Midway, S.R.; Wagner, Tyler

    2016-01-01

    Despite being a large, conspicuous teleost with a worldwide tropical and temperate distribution, the giant oarfish Regalecus spp. remain very rare fish species in terms of scientific sampling. Subsequently, very little biological information is known about Regalecus spp. and almost nothing has been concluded in the field of age and growth (Roberts, 2012). No studies of otoliths or temporal (annual) markings on any hard structures have been reported, and to our knowledge otoliths have never been recovered from any specimens (Tyson Roberts, personal communication),although a few texts do provide illustrations of Regalecus sp. otoliths (Lin and Chang, 2012; Nolf, 2013). Further inferential difficulty comes from the fact that age and growth studies of any Lampridiforme species are rare. Lampris guttatus is perhaps the only Lampridiforme species for which any biological information has been reported(Francis et al., 2004), which stems from the species commercial value. In order to begin understanding any species (for later purposes of management, conservation, etc.), basic biological information is needed. In the present study, we examine not only the first Regalecus russellii otolith, but provide suggestions toward future work that should direct data collection that can be used to generate basic biological information for this species.

  8. Regional movements of the tiger shark, Galeocerdo cuvier, off Northeastern Brazil: inferences regarding shark attack hazard.

    Science.gov (United States)

    Hazin, Fábio H V; Afonso, André S; De Castilho, Pedro C; Ferreira, Luciana C; Rocha, Bruno C L M

    2013-09-01

    An abnormally high shark attack rate verified off Recife could be related to migratory behavior of tiger sharks. This situation started after the construction of the Suape port to the south of Recife. A previous study suggested that attacking sharks could be following northward currents and that they were being attracted shoreward by approaching vessels. In this scenario, such northward movement pattern could imply a higher probability of sharks accessing the littoral area of Recife after leaving Suape. Pop-up satellite archival tags were deployed on five tiger sharks caught off Recife to assess their movement patterns off northeastern Brazil. All tags transmitted from northward latitudes after 7-74 days of freedom. The shorter, soak distance between deployment and pop-up locations ranged between 33-209 km and implied minimum average speeds of 0.02-0.98 km.h-1. Both pop-up locations and depth data suggest that tiger shark movements were conducted mostly over the continental shelf. The smaller sharks moved to deeper waters within 24 hours after releasing, but they assumed a shallower (shark movements in the South Atlantic, this study also adds new information for the reasoning of the high shark attack rate verified in this region.

  9. Recognizing cephalopod boreholes in shells and the northward spread of Octopus vulgaris Cuvier, 1797 (Cephalopoda, Octopodoidea)

    NARCIS (Netherlands)

    Hiemstra, Auke-Florian

    2015-01-01

    Octopuses prey on molluscs by boring through their shell. Among the regular naticid borings, traces of cephalopod predation should be found soon on Dutch beaches. Bottom trawling has declined, and by the effects of global warming Octopus will find its way back to the North Sea where it lived before.

  10. Morphologic characterisation and elemental distribution of Octopus vulgaris Cuvier, 1797 vestigial shell

    Energy Technology Data Exchange (ETDEWEB)

    Napoleao, P. [Departamento de Biologia Animal, Faculdade de Ciencias de Lisboa, C2, Campo Grande 1749-016, Lisbon (Portugal); Reis, C. Sousa [Departamento de Biologia Animal, Faculdade de Ciencias de Lisboa, C2, Campo Grande 1749-016, Lisbon (Portugal); Alves, L.C. [Laboratotio de Feixes de Ioes, Instituto Tecnologico e Nuclear, Estrada Nacional no. 10, 2685-953 Sacavem, Lisbon (Portugal); Centro de Fisica Nuclear, Universidade de Lisboa, Av. Prof. Egas Moniz 1700, Lisbon (Portugal); Pinheiro, T. [Laboratotio de Feixes de Ioes, Instituto Tecnologico e Nuclear, Estrada Nacional no. 10, 2685-953 Sacavem, Lisbon (Portugal) and Centro de Fisica Nuclear, Universidade de Lisboa, Av. Prof. Egas Moniz 1700, Lisbon (Portugal)]. E-mail: murmur@itn.mces.pt

    2005-04-01

    The elemental composition of mineral structures in marine organisms can provide useful information to reconstruct environmental histories of individuals and distinguish populations or stocks. In cephalopods, as Octopus vulgaris, morpho-physiological description of vestigial shells may contribute to a better understanding of the physiology, of the process involved in the increment growth and may eventually provide important and useful tools for the validation of age determination methods. Nuclear microprobe analysis was used to map chemical elements in O. vulgaris vestigial shell. The maps contain elemental and morphological information, and enabled especially through Cl and Ca distributions to classify bands of concentric rings. The levels of P, Ca and Sr decrease from central region to external rings, while those of S and Cl showed an inverse tendency. Enhanced concentrations of Fe, Cu and Zn were found in external rings, and no significant variations were detected in the K and Br contents. The results indicate that three regions can be established on the basis of the elemental contents distributions. Specially, the P and Ca variability can distinguish rings from central and external regions. The differential incorporation of elements in the vestigial shell observed may reflect environmental and physiological factors that are affecting the life cycle of this species.

  11. Estrutura morfológica do fígado de tambaqui Colossoma macropomum (Cuvier, 1818

    Directory of Open Access Journals (Sweden)

    Gerlane de Medeiros Costa

    2012-09-01

    Full Text Available Este trabalho teve como objetivo descrever macro e microscopicamente o fígado do Tambaqui Colossoma macropomum, Teleósteo de água doce da Família Characidae, de grande interesse econômico da bacia Amazônica. Foram utilizados seis (6 exemplares jovens com idade entre seis meses e um ano, oriundos da Chácara Esteio, Alta Floresta, MT, que desenvolve principalmente a prática da piscicultura. O órgão foi fotodocumentado in situ e descrito macroscopicamente, em seguida procedeu-se a retirada de fragmentos deste, que foram processados pelas técnicas histológicas rotineiras para inclusão em parafina e coloração de HE. O fígado localizou-se ventral à bexiga natatória e craniodorsalmente ao estômago, apresentou coloração amarronzada a vermelho, constituído por três lobos hepáticos, o lobo lateral direito, o lobo lateral esquerdo e o lobo ventral. Microscopicamente, o parênquima era constituído por hepatócitos com formato que variou do arredondado irregular hexagonal ao redondo com núcleo grande e central, arranjados em cordões lineares limitados por sinusóides que irradiam para veias centrais, e com ausência de lóbulos hepáticos. As veias centrais estavam distribuídas pelo parênquima, enquanto que o espaço porta, na maioria das vezes, era constituído apenas por uma veia hepática e o ducto biliar, em outros locais foi observado, uma artéria e um ducto. Não foi observada a formação de tríades portais. Foram frequentemente observados melano macrófagos centrais dispersos pelo parênquima. O estudo morfofuncional do Aparelho Digestório de peixes da bacia Amazônica, se faz pertinente com vistas ao conhecimento do aproveitamento de ganho de peso e produção em alta escala para consumo humano e preservação da espécie, além da importância de estarem sendo utilizados como bioindicadores atualmente.

  12. Crecimiento en cautiverio de Crocodylus acutus (Cuvier, 1807 en Tumbes, Perú

    Directory of Open Access Journals (Sweden)

    Oswaldo Pérez

    2013-04-01

    Full Text Available Se evaluó el crecimiento en peso y longitud en 40 individuos del Cocodrilo de Tumbes en el Centro de Acuicultura La Tuna Carranza, localizado en Puerto Pizarro, Departamento de Tumbes. No se observó una diferencia en el incremento en longitud por clases de edad, mientras que en peso si presentaron diferencias siendo mayor en adultos. El crecimiento promedio de longitud y peso fue de 1,44% y 0,18% en crías, 1,30% y 0,10% en reclutas, 1,24 y 0,22% en juveniles, 1,24 y 0,48% en subadultos, y 1,01 y 0,75% en adultos. En general las hembras presentan un mayor crecimiento que los machos.

  13. Anatomy of the bucco-pharyngeal cavity of Salminus brasiliensis (Cuvier, 1817 (Pisces, Characidae, Salmininae

    Directory of Open Access Journals (Sweden)

    Eliane Menin

    2006-03-01

    Full Text Available The bucco-pharyngeal cavity of Salminus brasiliensis, an ichthyophagous species of fresh water, is anatomically adapted to predation. The wide buccal rift, the oral-aboral enlargement of the buccal cavity and the reduced thickness of the pharyngeal mastigatory apparatus favor the capture and deglutition of larger prey. In function of the oral and pharyngeal dentition type, pre-digestive food preparation does not occur. The pointed and curved teeth, together with the tongue which is relatively mobile, prevent the prey’s escape from the buccopharyngeal cavity. The passage of the food is facilitated by the absence of pronounced folds in the mucous membrane of this cavity and by the disposition of the oral and pharyngeal teeth. The characteristics of flat and thin lips, developed oral dentition, relatively mobile tongue, mucous membrane without folds, pharynx with denticules disposed in dentigerous areas and plates, and short and sharp gill-rackers are anatomical adaptations which are shared by S. brasiliensis and other ichthyophagous Characiformes species such as Salminus maxillosus, Salminus hilarii, Hoplias malabaricus, Hoplias lacerdae, Acestrorhynchus lacustris and Acestrorhynchus britskii. However, different to the mentioned species, except other Salmininae, S. brasiliensis possesses oral teeth of an unique type, present only in the jawbones and distributed in two series.

  14. Feeds and feeding strategies for Colossoma macropomum (Cuvier 1818) : fish growth as related to dietary protein

    NARCIS (Netherlands)

    Meer, van der M.B.

    1997-01-01

    Colossoma macropomum is an indigenous fish species from the Amazon region. The amino acid profile of its body protein proved to be similar to that of other fish species. Soya meal and fish meal have, based on their amino acid profiles, a comparable protein quality. This

  15. Comparative study on octopus vulgaris (cuvier, 1797) from the mediterranean and red sea coasts of egypt

    OpenAIRE

    Riad, R.; Gabr, H.R.

    2007-01-01

    Specimens from common octopus, Octopus vulgaris captured from the Red Sea and Mediterranean Sea showed significant differences in four of seven morphometric measurements .These differences are sufficient to recognize the populations of this species in the two habitats. The computed length-Wight relationship and condition factor for common octopus in both areas showed that representatives of this species from the Red Sea are heavier than those captured from the Mediterranean Sea for the same l...

  16. Morphological and biometric comparison of the scales of the barbels (Barbus cuvier) of Spain.

    Science.gov (United States)

    Miranda, R; Escala, M

    2000-09-01

    The scales of 386 specimens of the eight species of the genus Barbus present in Spain (B. bocagei, B. comiza, B. graellsii, B. guiraonis, B. haasi, B. meridionalis, B. microcephalus, and B. sclateri) were studied. Six scales were extracted from each specimen, measurements taken, and the number of radii noted. Indices were obtained from these data. Statistical analysis allowed two groups to be established: 1) B. meridionalis and B. haasi, living in the upper stretches of rivers and distributed in the north of Spain; and 2) the remaining species. Within both groups a latitudinal gradation in the elongation of the scales and in the proportion of radii of the lateral fields was observed. Copyright 2000 Wiley-Liss, Inc.

  17. Glycoconjugates in the branchial mucous cells of Cynoscion guatucupa (Cuvier, 1830 (Pisces: Sciaenidae

    Directory of Open Access Journals (Sweden)

    Alcira O. Diaz

    2005-12-01

    Full Text Available This study examines the mucous cells from the gills of the stripped weakfish Cynoscion guatucupa. The glycoconjugates (GCs were identified with: (1 oxidizable vicinal diols; (2 sialic acids and some of their chain variants, C7, C8 or C9; (3 sialic acid residues with O-acyl substitution at C7, C8 or C9; (4 carboxyl groups and (5 sulphate groups. The presence of sugar residues in the oligosaccharide side chain of glycoconjugates was investigated by means of a battery of seven biotinylated lectins. One type of mucous cell was identified in the primary and secondary lamellae, the secretory content of which evidenced neutral, sulphated and sialylated glycoconjugates. The distribution pattern of the mucus was identical in the primary and secondary lamellae. PNA had the most staining in the mucous cell content, while UEA-I had the least, as it was completely negative. Con-A showed weak to no staining and WGA showed weak to moderate staining. The reactions to DBA, SBA and RCA-I were moderate. This work clearly demonstrates the heterogeneity of the mucous cell glycoconjugates, which could be involved in various functions, such as lubrication, protection, inhibition of microorganisms and a role in ion regulation and diffusion.

  18. Pu oxidation state distributions in suspensions of the Mont Terri Opalinus Clay isolate Sporomusa sp. MT-2.99

    Energy Technology Data Exchange (ETDEWEB)

    Moll, Henry [Helmholtz-Zentrum Dresden-Rossendorf e.V., Dresden (Germany). Biogeochemistry; Cherkouk, Andrea [Helmholtz-Zentrum Dresden-Rossendorf e.V., Dresden (Germany). HZDR Young Investigator Group; Bok, Frank [Helmholtz-Zentrum Dresden-Rossendorf e.V., Dresden (Germany). Surface Processes

    2017-06-01

    The time-dependent {sup 242}Pu oxidation state distribution in the presence of Sporomusa sp. cells as a function of pH with or without Na-pyruvate was analyzed. In all cases, the presence of bacterial cells enhanced removal of Pu from solution and accelerated Pu interaction reactions, e.g. biosorption and bioreduction.

  19. Cementitious Near-Field Sorption Data Base for Performance Assessment of an ILW Repository in Opalinus Clay

    Energy Technology Data Exchange (ETDEWEB)

    Wieland, E.; Van Loon, L. R

    2003-08-01

    The present report describes a cement sorption database (SDB) for the safety-relevant radionuclides to be disposed of in the planned Swiss repository for long-lived intermediate-level radioactive wastes (ILW). This report is an update on earlier SDBs, which were compiled for the cementitious near field of a repository for low- and intermediate-level radioactive wastes (L/ILW) by BRADBURY + SAROTT (1995) and BRADBURY + VAN LOON (1998). The radionuclide inventories are determined by the waste streams to be disposed of in the ILW repository. A list of the safety-relevant radionuclides was provided based on the currently available information on ILW inventories. The compositions of the cement porewaters in the near fields of the L/ILW and ILW repositories, which had been calculated using well-established codes for modelling cement degradation, were compared to identify any differences in the near-field conditions and to assess their influence on radionuclide sorption. Sorption values were selected based on the previously reported SDBs for the near field of the L/ILW repository. Sorption values were revised if new information and/or data were available which allowed changes to or re-appraisals of the data to be made. The sorption values recommended in this report were either selected on the basis of data from in-house experimental studies or from literature data. For some key radioelements, i.e., Cs(l), Sr(II), Ni(II), Eu(lll), Th(IV) and Sn(IV), new data were available from in-house measurements. These elements had been selected for experimental studies due to their relevance to safety assessment and/or their importance as appropriate chemical analogues. Degradation products of bitumen and cellulose, concrete admixtures and cement-derived near-field colloids were taken into account as the main potential perturbations, which could reduce radionuclide sorption in the near field. Possible impacts of the perturbing factors on radionuclide mobility were considered and quantified in terms of sorption reduction factors. (author)

  20. Pu oxidation state distributions in suspensions of the Mont Terri Opalinus Clay isolate Sporomusa sp. MT-2.99

    International Nuclear Information System (INIS)

    Moll, Henry; Cherkouk, Andrea; Bok, Frank

    2017-01-01

    The time-dependent "2"4"2Pu oxidation state distribution in the presence of Sporomusa sp. cells as a function of pH with or without Na-pyruvate was analyzed. In all cases, the presence of bacterial cells enhanced removal of Pu from solution and accelerated Pu interaction reactions, e.g. biosorption and bioreduction.

  1. Dieta e sobreposição de nichos de duas espécies de gerreídeos, Eugerres brasilianus (Cuvier, 1830) e Diapterus rhombeus (Cuvier, 1829) capturadas no canal de Santa Cruz, Itamaracá, Pernambuco.

    OpenAIRE

    Robson Tavares Barbosa

    2012-01-01

    Neste trabalho foram avaliados os perfis sazonais das dietas de Eugerres brasilianus e Diapterus rhombeus, e, a sobreposição alimentar entre estas espécies capturadas no canal de Santa Cruz, localizado no litoral norte do estado de Pernambuco, no período de junho de 2010 a maio de 2011. Teve como objetivo fornecer subsídios que sirvam de base para estudos voltados para o cultivo e uso sustentável destas espécies. Para entender seus hábitos alimentares, foram analisados 837 indivíduos das duas...

  2. Indicios indirectos de la presencia del oso andino (Tremarctos ornatus Cuvier, 1825 en el noroeste de Argentina Indirect evidence on the presence of the Andean bear (Tremarctos ornatus Cuvier, 1825 in northwestern Argentina

    Directory of Open Access Journals (Sweden)

    J. Fernando Del Moral

    2009-06-01

    Full Text Available La presencia de osos andinos (Tremarctos ornatus en Argentina ha sido muy discutida debido a la ausencia de evidencia confirmativa. Muchos expertos en el oso dudan actualmente de su presencia en el país. No obstante, la Selva Tucumano-Boliviana o de Yungas es un ecosistema típico donde se puede encontrar esta especie; particularmente en el área estudiada, el hábitat parece ser de alta calidad para los osos. Entre los años 2001 y 2006, se recopilaron 23 casos de evidencia sobre la presencia de osos andinos en las provincias de Salta y Jujuy. Se registraron huellas, restos alimenticios y heces. Adicionalmente, se entrevistó a nativos, agricultores y cazadores para colectar otros datos sobre la especie. Se concluye que las selvas de Yungas del extremo noroeste de Argentina, deben ser consideradas un área con alta probabilidad de mantener una población residente de osos andinos. Aunque posiblemente esta sea una población aislada y pequeña, la presencia permanente de osos andinos en el noroeste de Argentina no debería ser puesta en duda.The presence of Andean bears (Tremarctos ornatus in Argentina has been disputed due to the absence of confirming evidence. Many Andean bear experts currently doubt on their presence in this country. Nevertheless, the Tucuman-Bolivian Forest or Yungas is a typical ecosystem where this species can be found, particularly in the studied area, in which the habitat appears to be of high quality for bears. Between 2001 and 2006, 23 cases of evidence on the presence of Andean bears in the provinces of Salta and Jujuy were recorded. Footprints, food remains and scats were found. In addition, natives, farmers, and hunters where interviewed to collect new data of this species. The conclusion is that the Yungas Forest of northwestern Argentina must be considered an area with high probability of maintaining a resident population of Andean bears. Although this is probably a small and perhaps isolated population, the permanent presence of Andean bears in northwestern Argentina might not longer be doubted.

  3. Efeito sazonal sobre os ácidos graxos e colesterol do polvo Octopus vulgaris Cuvier 1797 Seasonal effects on fatty acids and cholesterol contents in Octopus vulgaris Cuvier 1797

    Directory of Open Access Journals (Sweden)

    Margarida Maria Monteiro Vasconcelos

    2010-06-01

    Full Text Available Foi realizado um estudo sobre o perfil de ácidos graxos e colesterol na manta de polvo comum, Octopus vulgaris, capturado na praia de Camocim - CE, no decorrer dos meses de abril a outubro em coletas bimensais. Apesar do ácido oleico (C18: 1n9 apresentar comportamento uniforme ao longo do tempo de coleta, a maioria dos demais ácidos graxos foi afetada (p = 1% pela época de coleta. Os níveis dos ácidos araquidônico (C20:4n6, oleico (C18:1n9, esteárico (C18:0 e linoleico (C18:2n6 foram superiores àqueles reportados na literatura. O somatório de ácidos graxos poli-insaturados e monoinsaturados revelou que o óleo de polvo apresenta um teor significativo de ácidos graxos insaturados. Foi observado um aumento gradativo de colesterol ao longo do tempo estudado e um comportamento inverso para a relação de ácidos graxos n3/n6.The aim of this study was to investigate the fatty acids and cholesterol profile in the mantle of common octopus, Octopus vulgaris, collected twice a month in in coastal waters of Camocim/CE beach over the period from April to October. Although the Oleic acid (C18:n9 did not show significant changes over the months, the majority of fatty acids varied during this period of time. The Arachidonic (C20:4n6, oleic (C18:n9, stearic (C18:0, and linoleic (C18:2n6 acids were found in higher levels than those reported in the literature. Polyunsaturated and unsaturated fatty acids accounted for most of the octopus fatty acids. During the time of analysis, it was observed a gradual increase in the cholesterol and the fatty acids n3/ n6 ratio presented the opposite result, i.e., a gradual decrease.

  4. Morfologia e crescimento do músculo estriado esquelético no pirarucu Arapaima gigas Cuvier, 1817 (Teleostei, Arapaimidae = Morphology and skeletal muscle growth in pirarucu Arapaima gigas Cuvier, 1817 (Teleostei, Arapaimidae

    Directory of Open Access Journals (Sweden)

    Fernanda Regina Carani

    2008-04-01

    Full Text Available O objetivo deste trabalho foi avaliar as características morfológicas e de crescimento do músculo estriado esquelético no pirarucu (Arapaima gigas. Foram utilizados animais em duas fases de crescimento: alevinos, com 50 dias de idade, e juvenis, com umano de idade. Após eutanásia dos animais, fragmentos musculares das regiões dorsal, lateral cranial e lateral caudal foram coletados e congelados em nitrogênio líquido. Cortes histológicos (10 mm foram submetidos às colorações HE e Tricrômico de Gomori, para a análise morfológica, e NADH-TR, para a análise do metabolismo oxidativo das fibras musculares. Foi calculado o menor diâmetro das fibras musculares brancas nas regiões dorsal e lateral cranial. A musculatura dorsal branca mostrou-se mais desenvolvida e, namusculatura lateral, observaram-se compartimentos distintos: superficial vermelho e profundo branco. Nos alevinos, o crescimento muscular ocorreu predominantemente por hiperplasia das fibras e, nos juvenis, predominou o crescimento muscular por hipertrofia.The aim of this work was to evaluate the morphological and growth characteristics of skeletal muscle tissue in pirarucu (Arapaimagigas using alevins (50 days old and juveniles (1 year old. Muscle samples were collected from dorsal, lateral cranial and lateral caudal regions, and then frozen in liquid nitrogen. Histological frozen sections (10μm were stained with HE and Gomori Trichrome formorphological analysis, and NADH-TR to evaluate muscle fiber oxidative metabolism. Morphometric analysis samples were obtained from dorsal and lateral cranial regions, and the smallest-diameter white fibers were measured. White dorsal muscle was thicker, andtwo muscle fiber compartments were identified in the lateral cranial region: red (superficial and white (deep muscle. Hyperplasia muscle growth predominated in alevins and hypertrophy in juveniles.

  5. Trackline and Point Detection Probabilities for Acoustic Surveys of Cuvier’s and Blainville’s Beaked Whales

    Science.gov (United States)

    2013-09-01

    of sperm whales. Although the methods developed in those papers demonstrate feasibility, they are not applicable to a)Author to whom correspondence...information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and...location clicks (Marques et al., 2009) instead of detecting individual animals or groups of animals; these cue- counting methods will not be specifically

  6. An outbreak of myxozoan parasites in farmed freshwater fish Colossoma macropomum (Cuvier, 1818 (Characidae, Serrasalminae in the Amazon region, Brazil

    Directory of Open Access Journals (Sweden)

    Marcela Videira

    2016-05-01

    Full Text Available The tambaqui (Colossoma macropomum is a native fish species that is farmed most frequently and in the largest quantities throughout Brazil. The high production of this species from fish farms has contributed to the occurrence of emerging parasites, which may compromise fish health and productivity. In a batch of 2500 tambaqui fry acquired for experimental farming procedures in Brazil, a mortality rate of 80% was observed, with the fish swimming erratically and gasping for air at the water surface. From among the specimens that were still alive, 60 individuals were selected at random. Organs or fragments of organs containing lesions and/or cysts were examined under an optical microscope to investigate for the presence of parasitic spores. Of the 60 specimens of tambaqui analyzed, 83.3% were found to be infected in different organs, such as the gills, liver, and gallbladder with myxosporidian species belonging to four genera, namely, Myxobolus, Ellipsomyxa, Henneguya and Thelohanellus. The parasite with the greatest prevalence was Myxobolus sp., located in the gills (70%, followed by Henneguya sp. in the gills region (68.3%, Myxobolus sp. in the liver (63.3%, Thelohanellus sp. in the liver (58.3%, and Ellipsomyxa in the gallbladder (50%. This is the first report of parasitic infection caused by the genera Ellipsomyxa and Thelohanellus in C. macropomum. The present study reported the second incidence of the occurrence of the genus Thelohanellus in South America. This study suggested that the mortality among C. macropomum specimens was caused by the outbreak of myxosporidians. Keywords: Amazon, Tambaqui, Parasite, Myxozoa, Myxosporidians

  7. Population analysis of Scomberomorus cavalla (Cuvier, 1829 (Perciformes, Scombridae from the Northern and Northeastern coast of Brazil

    Directory of Open Access Journals (Sweden)

    EL. Santa Brígida

    Full Text Available Scomberomorus cavalla is a pelagic fish species widely distributed on the Atlantic west coast, and a noticeable decrease in its capture level in the USA and Gulf of Mexico is occurring, compared to the levels reached by the species in the past. Likewise, in some areas of Brazil, there has been indication of over-harvesting. However, there are no molecular studies focusing on the management of such an important item. Thus, in the present study, 380 nucleotide base pairs of the mitochondrial DNA D-Loop region of samples from Macapá, Bragança, and Fortaleza were sequenced. Phylogenetic and population analyses revealed that there is only one panmitic population, and low levels of genetic variability were verified. These results, as well as the noticed over-harvesting of S. cavalla, represent very important data to determine the management of such stock in order to prevent a collapse or the risk of future extinction.

  8. Fatal tiger shark, Galeocerdo cuvier attack in New Caledonia erroneously ascribed to great white shark, Carcharodon carcharias.

    Science.gov (United States)

    Tirard, Philippe; Maillaud, Claude; Borsa, Philippe

    2015-07-01

    To understand the causes and patterns of shark attacks on humans, accurate identification of the shark species involved is necessary. Often, the only reliable evidence for this comes from the characteristics of the wounds exhibited by the victim. The present case report is intended as a reappraisal of the Luengoni, 2007 case (International Shark Attack File no. 4299) where a single shark bite provoked the death of a swimmer by haemorrhagic shock. Our examination of the wounds on the body of the victim, here documented by so-far unpublished photographic evidence, determined that the shark possessed large and homodontous jaws. This demonstrates that the attacker was a tiger shark, not a great white shark as previously published. Copyright © 2015 Elsevier Ltd and Faculty of Forensic and Legal Medicine. All rights reserved.

  9. Advantages of recovery from pre-slaughter stress in tambaqui Colossoma macropomum (Cuvier 1816) agroindustry in the Amazon

    OpenAIRE

    MENDES,Joana Maia; DAIRIKI,Jony Koji; INOUE,Luis Antonio Kioshi Aoki; JESUS,Rogério Souza de

    2017-01-01

    Abstract Tambaqui is the main fish species farmed in the Amazon. It is produced on industrial scale, slaughtered in the field, primarily by post-harvest asphyxia. This procedure, however, is stressful because it depletes energy reserves that should be used in postmortem metabolism, which may compromise fish meat freshness and quality. The present study compared the quality of tambaquis slaughtered by asphyxia, the conventional industrial method, and hypothermia. Tambaquis weighing around 1.6 ...

  10. Prevalence of intestinal parasitic infections in free-ranging Red Panda Ailurus fulgens Cuvier, 1825 (Mammalia: Carnivora: Ailuridae in Nepal

    Directory of Open Access Journals (Sweden)

    Sonam Tashi Lama

    2015-06-01

    Full Text Available The Red Panda Ailurus fulgens is a small carnivore that is adapted to a mainly herbivorous diet.  The present study was conducted to investigate the prevalence of parasitic infections in a free-ranging population of Red Pandas in a community forest in Nepal.  A total of 23 faecal samples were collected and examined.  Protozoa infections were the most common and cestode infections occurred the least.  Our findings suggest that parasites might be a significant problem for the health of the Red Pandas in the study area.  Molecular methods should be used to further investigate the taxonomic position of the parasites and their role in threatening the resilience of Red Panda populations in Nepal.  

  11. Advantages of recovery from pre-slaughter stress in tambaqui Colossoma macropomum (Cuvier 1816 agroindustry in the Amazon

    Directory of Open Access Journals (Sweden)

    Joana Maia MENDES

    Full Text Available Abstract Tambaqui is the main fish species farmed in the Amazon. It is produced on industrial scale, slaughtered in the field, primarily by post-harvest asphyxia. This procedure, however, is stressful because it depletes energy reserves that should be used in postmortem metabolism, which may compromise fish meat freshness and quality. The present study compared the quality of tambaquis slaughtered by asphyxia, the conventional industrial method, and hypothermia. Tambaquis weighing around 1.6 kg were harvested from dugout ponds, transported to experimental tanks and allowed to recover from transport stress for 48h. Biological parameters of fish were evaluated alive post- harvest (Harv, transport (Tr and recovery (Rc, and postmortem analysis was performed in fish slaughtered by asphyxia (Asph or hypothermia (Hyp after transport and recovery. Initial observations showed that the content of total volatile nitrogen bases (TVB-N and pH were higher in fish killed by asphyxia. Sensory analysis indicated that the quality of fish slaughtered immediately after transport was lower than in fish allowed to recover from pre-slaughter stress. The results suggest that recovery from pre-slaughter stress contributes to preserving meat freshness and quality in tambaquis slaughtered on an industrial scale, but other studies are required to determine the feasibility of this recommendation.

  12. Viviparous Monogenea on grey bichir, Polypterus senegalus Cuvier in the National park Niokolo Koba (Senegal, West Africa)

    Czech Academy of Sciences Publication Activity Database

    Přikrylová, I.; Matějusová, I.; Reichard, Martin; Gelnar, M.

    2007-01-01

    Roč. 49, Suppl. 2 (2007), s. 98 ISSN 0048-2951. [International Symposium on Fish Parasites /7./. 24.09.2007-28.09.2007, Viterbo] R&D Projects: GA MŠk LC522; GA AV ČR IAA6093404 Institutional research plan: CEZ:AV0Z60930519 Keywords : Senegal * parasites Subject RIV: EG - Zoology

  13. Temporal Assessment of Natural Radionuclide Bioaccumulation by the Cubera Snapper Fish (Lutjanus Cyanopterus, Cuvier, 1828) from the Brazilian Coast

    Energy Technology Data Exchange (ETDEWEB)

    Pereira, W. S. [Coordenacao de Protecao Radiologica, Unidade de Tratamento de Mineiros (UTM), Industrias Nucleares do Brasil (INB), Pocos de Caldas, MG and Curso de Pos-Graduacao em Biologia Marinha, Instituto de Biologia, Depto. de Biologia Marinha, Universidade Federal Fluminense UFF, Niteroi, RJ (Brazil); Kelecom, A. [Curso de Pos-Graduacao em Biologia Marinha, Instituto de Biologia, Depto. de Biologia Marinha, Universidade Federal Fluminense (UFF), and Programa de Pos-Graduacao em Ciencia Ambiental, Universidade Federal Fluminense (UFF), Niteroi, RJ (Brazil); Py, Jr., D. A. [Coordenacao de Protecao Radiologica, Unidade de Tratamento de Mineiros (UTM), Industrias Nucleares do Brasil (INB), Pocos de Caldas, MG (Brazil)

    2013-07-15

    The present study aims to assess the seasonal variation in the accumulation of the isotopes {sup 238}U, {sup 235}U, {sup 234}U, {sup 232}Th, {sup 230}Th, {sup 228}Th, {sup 226}Ra, {sup 228}Ra and {sup 210}Pb in the cubera snapper fish from the coast of the state of Ceara (Brazil). The fish was caught in January (six specimens), June (eight) and September (seven). The uranium and thorium were analysed by electrodeposition, followed by alpha spectrometry. The isotopes of radium and lead were selectively co-precipitated and measured by gross alpha radiometry for {sup 226}Ra and gross beta radiometry for {sup 228}Ra and {sup 210}Pb. No seasonal variations could be observed neither for the uranium and thorium isotopes nor for the {sup 226}Ra isotope. For {sup 228}Ra, the activity concentration in February was equal to that of September, and both were higher than in June. For {sup 210}Pb, the situation was different: the month of February showed a lower activity concentration than in June, which in turn was lower than in September. (author)

  14. Production and quality assessment of fish burger from the grass carp, Ctenopharyngodon idella (Cuvier and Valenciennes, 1844

    Directory of Open Access Journals (Sweden)

    Monjurul Haq

    2013-12-01

    Full Text Available Fish burger was produced from grass carp (Ctenophygodon idella to assess the feasibility of value addition to this low priced fish in Bangladesh. Different food additives (25% mashed potato, 2% NaCl, 2% soybean oil, 2% spices and 0.6% sugar were used to enhance the consumer’s acceptance of the fishery product. Consumers' acceptance of the fish burger was determined by sensory evaluation based on its color, flavor, softness or firmness (S/F, chewy/ rubbery (C/R using 10 point scoring system by a group of 10 untrained judges (20-50 years old. The results were found as follows: color (7.25±1.15, flavor (6.67±1.17, S/F (8.47±1.20 and C/R (7.83±1.23. Evaluation of proximate composition showed that the moisture and protein contents in grass carp mince were 79.15 ± 1.16 % and 18.01±0.44 % respectively which were higher than that of fish burger, 69.46 ± 0.89 % and 16.42 ± 0.57 %, respectively. Lipid (6.64±0.15 % and ash (2.98±0.09 % contents in fish burger were also higher than fish mince. The pH of fish mince and fish burger was 6.8±0.11 and 6.6±0.05 respectively. Therefore, from simple cost-profit analysis, it can be assumed that business of fish burger in Bangladesh has a very good prospect and it would be profitable.

  15. Re-description and Reassignment of the Damselfish Abudefduf luridus (Cuvier, 1830) Using Both Traditional and Geometric Morphometric Approaches

    Energy Technology Data Exchange (ETDEWEB)

    Cooper, W. James [Washington State Univ., Pullman, WA (United States); Albertson, R Craig [Univ. of Massachusetts, Amherst, MA (United States); Jacob, Rick E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Westneat, Mark W. [Field Museum of Natural History, Chicago, IL (United States)

    2014-12-01

    Here we present a re-description of Abudefduf luridus and reassign it to the genus Similiparma. We supplement traditional diagnoses and descriptions of this species with quantitative anatomical data collected from a family-wide geometric morphometric analysis of head morphology (44 species representing all 30 damselfish genera) and data from cranial micro-CT scans of fishes in the genus Similiparma. The use of geometric morphometric analyses (and other methods of shape analysis) permits detailed comparisons between the morphology of specific taxa and the anatomical diversity that has arisen in an entire lineage. This provides a particularly useful supplement to traditional description methods and we recommend the use of such techniques by systematists. Similiparma and its close relatives constitute a branch of the damselfish phylogenetic tree that predominantly inhabits rocky reefs in the Atlantic and Eastern Pacific, as opposed to the more commonly studied damselfishes that constitute a large portion of the ichthyofauna on all coral-reef communities.

  16. Experimental infection of octopus vulgaris (Cuvier, 1797) with Photobacterium damsela subsp. piscicida. Immunohistochemical tracking of antigen and tissue responses.

    Science.gov (United States)

    Bakopoulos, Vasileios; White, Daniella; Valsamidis, Michail-Aggelos; Vasilaki, Feli

    2017-03-01

    Adult common octopus individuals were intramuscularly infected with Photobacterium damsela subsp. piscicida in order to investigate if this species is sensitive to this common and important fish pathogen. The fate of the bacterial antigens and the tissue responses of Octopus vulgaris were studied employing immunohistochemical techniques. Strong reaction at the site of injection was evident from day 2 post-infection that continued until day 14. Great numbers of hemocytes that were attracted at the site of infection were involved in phagocytosis of bacteria. Very early in the infection, a transition of cells to fibroblasts and an effort to isolate the infection was observed. During the course of the study, very large necrotic cells were seen at the site of infection, whereas during the later stages hemocytes with phagocytosed bacteria were observed in well-defined pockets inside the muscle tissue. None of the internal organs tested for the presence of the bacterium were positive with the exception of the digestive gland where antigen staining was observed which was not associated with hemocyte infiltration. The high doses of bacterial cells used in this experimental infection and the lack of disease signs from Octopus vulgaris suggest that, under normal conditions, octopus is resistant to Photobacterium damsela subsp. piscicida. Copyright © 2017 Elsevier Inc. All rights reserved.

  17. A new artificial reef design for octopus (Octopus vulgaris cuvier, 1797 in the Aegean sea and preliminary results

    Directory of Open Access Journals (Sweden)

    Ali Ula

    2011-01-01

    Full Text Available This study was carried out in the Gulf of 0zmir in the Aegean Sea between June 2006 and November 2008. The purpose was the creation of a new concept of the artificial reef for Octopus vulgaris, with a view to establishing new artificial reef sites to be used in the fisheries management of this species (MPA, NTZ or fishing areas. First, the main characteristics of natural octopus nests were recorded (entrance width, length, etc. by divers. These characteristics were used in the construction of new octahedral artificial reef blocks. The blocks were made of reinforced concrete, in a shape like that of an inverted pyramid, with an upper surface of 100x100x25 cm³ and a lower one of 60x60 cm². Four cylindrical holes each with two ellipsoidal openings were placed in one face and in the lateral edge of the octo-block, to serve as the entrances to the artificial nest. Each nest has a volume of 5000 cm³. Eighty octo-blocks were deployed as artificial reefs at 10 m from each other at 15 different depths at two sites by divers with the help of the winch of the R/V EGESUF. These artificial octo-reefs were censused by direct observation. Twenty-eight octopuses were sampled at the end of 25 dives. Minimum mantle length of the octopuses was 75 mm and the maximum 249 mm, with an average of 152.71 mm. The average total length was calculated to be 918.57 mm. The weight of the specimens was between 244 g and 7140 g with an average of 2335.43 g. The results showed that both sites were inhabited by octopuses coming from the artificial reefs, which used them as nests. These nests seem to have constituted special places for fisheries management and will permit the assessment of reserve areas or marine protection areas (MPA, thus opening up a new perspective for Turkish fisheries.Este estudo foi realizado no golfo de 0zmir, no Mar Egeu, entre junho de 2006 e novembro de 2008. O objetivo foi uma nova concepção de recife artificial para Octopus vulgaris, visando o estabelecimento de novos locais a serem utilizados na gestão da pesca dessa espécie (MPA, NTZ ou zonas de pesca. Primeiramente foram consideradas as principais características dos ninhos naturais do polvo (largura da entrada, comprimento, etc.. A seguir essas características foram utilizadas na construção de novos blocos octaédricos de recifes artificiais. Os blocos foram feitos de concreto armado, assemelhando-se a uma pirâmide invertida, nas dimensões de 100x100x25 cm³ na face superior e 60x60 cm² na face inferior. Quatro furos cilíndricos, com duas aberturas elipsoidais, foram dispostos em uma só face e na borda lateral do octo-bloco, correspondendo às entradas do ninho artificial. Cada ninho tem um volume de 5000 cm³. Foram implantados 80 octo-blocos para servirem como recifes artificiais, guardando a distância de 10 m entre si, em 15 profundidades e em dois locais diferentes, com auxílio de mergulhadores e guincho do R/ V EGESUF. Esses recifes foram recenseados, utilizando-se o método de observação direta. Vinte e oito polvos foram amostrados ao final de 25 mergulhos. O comprimento mínimo do manto do polvo foi de 75 mm e o máximo de 249 mm, com média de 152,71 mm. O comprimento médio total foi determinado em 918,57 mm. O peso dos espécimes ficou entre 244 e 7140 g, com média de 2335,43 g. Os resultados mostram que ambos os locais foram sustentados pelos polvos provenientes dos recifes artificiais, que os utilizaram como ninhos. Esses ninhos parecem constituir locais especiais para manejo da pesca, e permitirão a avaliação de áreas de reserva ou áreas marinhas de proteção (MPA, abrindo, desta forma, novas perspectivas para a pesca turca.

  18. Behavioral Responses of Nave Cuvier’s Beaked Whales in the Ligurian Sea to Playback of Anthropogenic and Natural Sounds

    Science.gov (United States)

    2015-09-30

    University of St Andrews St Andrews , Fife, KY16 8LB, UK phone: (+44) 01334 462630 fax: (+44) 01334 463443 email: plt@st-andrews.ac.uk...exercises and where the whales seldom hear sonar. APPROACH The University of St Andrews was the prime grantee for this project. The PI, Peter Tyack...was ultimately responsible for the project. Leigh Hickmott, also supported through the University of St Andrews , acted as the cruise science lead

  19. Fatal tiger shark, Galeocerdo cuvier attack in New Caledonia erroneously ascribed to great white shark, Carcharodon carcharias

    OpenAIRE

    Tirard, P.; Maillaud, C.; Borsa, Philippe

    2015-01-01

    International audience; To understand the causes and patterns of shark attacks on humans, accurate identification of the shark species involved is necessary. Often, the only reliable evidence for this comes from the characteristics of the wounds exhibited by the victim. The present case report is intended as a reappraisal of the Luengoni, 2007 case (International Shark Attack File no. 4299) where a single shark bite provoked the death of a swimmer by haemorrhagic shock. Our examination of the...

  20. Pacu fish (Cuvier, 1818 (Characiformes: Characidae landed in Porto Velho (Rondônia fish market from 1985 to 2004

    Directory of Open Access Journals (Sweden)

    Maria Alice Leite Lima

    2008-09-01

    Full Text Available This study evaluated various aspects of the profile of pacu (Mylossoma spp., Myleus spp., Metynnis spp. fish marketed on the Cai N’água floating platform of Porto Velho (RO from 1985 to 2004. Inter- and intra-annual variations in yield, variation in fish length and general characteristics of the fishing are reported. The annual pacu yield ranged from 33,000kg to 146,000kg (average = 86,585kg, representing from 6.6% to 20.45% of the total landings in the studied period. These variations followed the hydrologic cycle, and the greatest yields were recorded in the years following the highest water levels. The monthly production ranged from 0 to 42,366kg (average = 5,772kg and it was related to reproductive migration. The pacu presented variations in standard length from 14 to 20cm (18.72cm ± 3.69, mean ± sd. The fishing was based on the use of seines and gill nets and the main environments of capture were tributaries of the low Madeira River (Jamari, Oropiara, Machado and Novo Aripuanã. The CPUE calculated for 2003 to 2005 was 15kg*fisherman 1day-1 (sd = ±21. The results show that the category constituted during this period an important resource for local commercial exploitations, as verified in other regions of the Amazon.

  1. Barracudia australiensis n. g., n. sp (Nematoda: Philometridae) from the obtuse barracuda Sphyraena obtusata Cuvier (Perciformes: Sphyraenidae) off eastern Australia

    Czech Academy of Sciences Publication Activity Database

    Moravec, František; Shamsi, S.

    2017-01-01

    Roč. 94, č. 6 (2017), s. 627-634 ISSN 0165-5752 R&D Projects: GA ČR(CZ) GBP505/12/G112 Institutional support: RVO:60077344 Keywords : yamaguti * fishes * coast Subject RIV: GJ - Animal Vermins ; Diseases, Veterinary Medicine OBOR OECD: Veterinary science Impact factor: 1.181, year: 2016

  2. Comparative studies of bile salts. A new type of bile salt from Arapaima gigas (Cuvier) (family Osteoglossidae).

    Science.gov (United States)

    Haslewood, G A; Tökés, L

    1972-03-01

    1. Arapaima gigas bile salts were hydrolysed by alkali or cleaved with dioxan-trichloroacetic acid to give cholic acid, arapaimic acid, arapaimol-A and arapaimol-B. 2. I.r., n.m.r. and mass spectroscopy and [alpha](D) measurements indicated that arapaimic acid and arapaimol-A and -B are respectively 2alpha,3alpha,7alpha,12alpha-tetrahydroxy-5beta,25in-cholestan-26-oic acid, 5beta,25R-cholestane-2beta,3alpha,7alpha,12alpha,26-pentol and 5beta-cholestane-2beta,3alpha,7alpha,12alpha,26,27-hexol. 3. Partial synthesis of 2beta,3alpha,7alpha,12alpha-tetrahydroxy-5alpha- and -5beta-cholan-24-oic acid and their spectral examination fully confirmed these conclusions. 4. A. gigas bile salts show primitive features in that they comprise alcohol sulphates and a C(27) acid; they are also specialized in showing 2beta-hydroxylation.

  3. Lobocapillaria austropacifica n. g., n. sp (Nematoda: Capillariidae) from the obtuse barracuda Sphyraena obtusata Cuvier (Sphyraenidae, Perciformes) off eastern Australia

    Czech Academy of Sciences Publication Activity Database

    Moravec, František; Beveridge, I.

    2017-01-01

    Roč. 94, č. 5 (2017), s. 547-556 ISSN 0165-5752 R&D Projects: GA ČR(CZ) GBP505/12/G112 Institutional support: RVO:60077344 Keywords : intestinal parasite * new-caledonia Subject RIV: EG - Zoology OBOR OECD: Zoology Impact factor: 1.181, year: 2016

  4. Diurnal observations on the behavioral ecology of Gymnothorax moringa (Cuvier) and Muraena miliaris (Kaup) on a Caribbean coral reef

    Science.gov (United States)

    Abrams, R. W.; Abrams, M. D.; Schein, M. W.

    1983-09-01

    Activities of muraenids, primarily Gymnothorax moringa and Muraena miliaris, were observed on a Caribbean coral reef with a view to further understanding their role in the reef ecosystem. Other muraenid species included in the total of 198 sightings were Echidna catenata, Enchelycore nigricans, and an unidentified brown moray. The five species were unequally distributed among three basic habitats (sand, coral head, reef rock) available on the reef. Nine particular holes accounted for 52.5% of the total sightings, although hundreds of other seemingly appropriate sites were available. The eels (except M. miliaris) were transient with respect to given holes and particular sections of the reef. While some G. moringa were sighted in the same holes for several consecutive days, M. miliaris individuals remained in the same coral heads throughout the 6-week study period. Muraenids observed in this study showed high tolerances for and were tolerated by other fishes (including other morays) and invertebrates on the reef. They appeared to be opportunistic, roving predators and were not strictly nocturnal. Distinct behavioral interactions and displays between muraenids and reef fish were observed.

  5. Caracterización seminal en sabaleta brycon henni: evaluación de factores inhibidores y activadores de la motilidad espermática

    Directory of Open Access Journals (Sweden)

    Martha Olivera

    2004-02-01

    Full Text Available

    La sabaleta es una especie endémica de las cuencas del Río Cauca y se presenta como una alternativa para la seguridad alimentaria y mantenimiento de la diversidad, sin embargo, se desconocen sus características reproductivas. El objetivo de este trabajo fue caracterizar el balance iónico del plasma seminal y evaluar si la activación de la motilidad está relacionada con el cambio en las concentraciones iónicas del plasma seminal.(1

     

     

  6. Seasonal variation of sperm quality and the relationship between spermatocrit and sperm concentration in yamú Brycon amazonicus

    DEFF Research Database (Denmark)

    Cruz-Casallas, Pablo E.; Medina-Robles, Víctor M.; Velasco-Santamaría, Yohana M.

    2007-01-01

    and sperm concentration were examined over two reproductive seasons. Activation time, spermatocrit, and sperm concentration were significantly higher in 2003 than in 2004. Spermatocrit and sperm concentration showed a significant positive relationship (r2=0.79). During the 2004 reproductive season......, a significant variation was observed for spermatocrit and sperm concentration between the initial period (February 15th to March 14th) and the middle and final periods (March 15th to April 14th and April 15th to May 14th, respectively). Neither the ion concentrations nor the glucose and cholesterol...... concentrations varied between any periods of the reproductive season. Osmolality and triglyceride concentrations showed significant variations between periods during the reproductive season....

  7. Sobre la ecología de Brycon siebenthalae y Mylossoma duriventris (Piscis: Characidae, en el río Cafre, Orinoquia

    Directory of Open Access Journals (Sweden)

    Useche L. Carlos

    1993-12-01

    Full Text Available The ecology of the characids Bryeon siebenthalaey Mylossoma duriventriswas studied in the lower part of the río Cafre, a tributary of was studied the río Guayabero in the upper part of the río Guaviare system in Colombia. These lishes spawn in the early rainy season; theír diet consist mainly 01 Iruits, seeds, flowers and bark.En este trabajo se reportan nuevos aspectos sobre la biología de Bryeon siebenthalae (yamú y de Mylossoma duriventris (palometa. La reproducción de especies está altamente relacionada con la estacionalidad hídrica (lluvias-sequías la palometa desova tan pronto comienzan las lluvias a finales de abril, con un promedio de 125.000 huevos; el yamú desova aproximadamente 231.000 huevos, dos a tres semanas más tarde, mediados de mayo. El alto número de huevos implica que el desove debe efectuarse en niveles de aguas que faciliten su dispersión. Las dos especies comparten los hábitat (cursos del río, planos inundables. Es característico del yamú su mayor desplazamiento al remontar grandes corrientes y raudales, en el desarrollo de su comportamiento migratorio de tipo longitudinal, a diferencia de la palometa cuyos movimientos son preleriblemente de tipo local y lateral a la corriente. En ambas especies predomina un hábito alimenticio macroherbívoro, correspondiente a frutos, semillas, hojas. flores y cortezas: para el yamú en un 93% y para la palometa en 99%.

  8. Feed restriction and insulin-like growth factor-I (IGF-I) affect the oocyte maturation in matrinxã Brycon amazonicus.

    Science.gov (United States)

    Montrezor, Luís Henrique; Urbinati, Elisabeth Criscuolo

    2017-02-01

    The feeding and nutrition of breeders are crucial aspects in the reproductive process. During the maturation period, metabolic changes occur aiming at mobilizing energy for growth and follicular development. The involvement of IGF-1 in metabolic and reproductive events is important. The aim of this work was to evaluate if alternate feed restriction and re-feeding have permissive effects on in vitro actions of IGF-1 on oocytes development of matrinxã. In vivo experiments were performed during vitellogenesis period. Females (n = 60) were fed with a commercial feed (2% of biomass) and they were divided into two treatments: fish receiving food daily (control - fed), and fish submitted to cycles of 3 days of feed restriction and 2 days of re-feeding (no-fed group). For the in vitro experiments, oocytes (n = 20) were obtained from the ovaries removed at the end of the in vivo experiment and were divided into four groups: fed -IGF-1; fed +IGF-1; no-fed -IGF-1 and no-fed +IGF-1. Fish under restriction had lower body weights, decreased plasma glucose, increased triglycerides levels, and their final maturation and mature oocyte were reduced and the atresic ones were in higher number. Moreover, IGF-1, in vitro, increased the percentage of mature oocytes in fed females and decreased the atresic ones. In no-fed females, IGF-1 increased the final maturation and mature oocytes and reduced the atresic ones. This study demonstrates the importance of the feeding management of female breeders of matrinxã during the vitellogenesis period.

  9. Efeito das classes de peso sobre a composição corporal e o rendimento de processamento de matrinxã (Brycon cephalus Effect of weight classes on body composition and processing yield of cultivated matrinxã (Brycon cephalus

    Directory of Open Access Journals (Sweden)

    Rose Meire Vidotti

    2000-05-01

    Full Text Available Matrinxã é um peixe originário da Bacia Amazônica que vem sendo cultivado na Região Sudeste, atendendo ao crescente mercado dos pesque-pague. Embora não exista um consenso sobre o peso de comercialização para essa espécie, ela tem sido realizada com exemplares acima de 600g. O objetivo deste trabalho foi avaliar o rendimento de processamento e a composição corporal do matrinxã em três classes de peso. Foram coletados em tanques de cultivo do Caunesp, Jaboticabal, SP, 45 exemplares, separados em três classes de peso: P1 = 400 a 500g; P2 = 501 a 600g e P3 = 601 a 700g, e submetidos ao processo de filetagem manual e determinação da composição corporal. Foram avaliados os seguintes parâmetros de rendimento (%: filé sem pele, vísceras, gordura visceral, carcaça sem cabeça, cabeça e resíduo total. Para a composição corporal foram determinados os teores de umidade, proteína bruta, lipídeos e cinzas. As classes de peso tiveram efeito (p 0,05. Os menores valores obtidos para carcaça sem cabeça e vísceras foram observados na classe P1 (75,94% e 8,38 e os maiores na P3 (78,05% e 9,48%. Destaca-se que a gordura visceral compreende em torno de 43% do total das vísceras em todas as classes de peso, havendo uma correlação positiva e significativa (r2 = 0,957* entre esses dois parâmetros. A composição corporal apresentou diferenças significativas apenas quanto aos teores de cinzas, sendo que o maior valor foi observado nos peixes da maior classe de peso. Embora não significativo, nota-se uma tendência de maior acúmulo de gordura nos peixes maiores. Este alto teor de lipídeos observado com o matrinxã reflete uma característica comum em espécies de peixes tropicais de água doce. Com base nesses resultados, pode-se concluir que os teores de proteína bruta e lipídeos apresentam-se semelhantes nas três classes de peso avaliadas, e, sem prejuízo do rendimento de filé, os peixes podem ser processados com pesos menores aos normalmente comercializados.Matrinxã is a native fish from the Amazon basin, which has been cultivated in the Southestern region due to increasing interest in sport fishing. Although there is no agreement on the ideal commercialization weight for the species, fishing has been carried out with fish above 600 g. This study aimed to determine the processing yield and body composition in three weight classes. Forty-five fish were collected in fish ponds at Caunesp, Jaboticabal, SP, according to the following weight classes: P1 = 400 to 500 g; P2 = 501 to 600 g; and P3 = 601 to 700 g. The fish were filleted and their body composition was determined. The following yield parameters (% were evaluated: skinless fillet, visceral fat, headless carcass, and total residue. For body composition, moisture (M, crude protein (CP, lipid (L, and ash (A were determined. The weight had effect on (p 0.05. The lowest value obtained for headless carcass and visceral components was observed for weight class P1 (75,94% e 8,38% and the highest for P3 (78,05% e 9,48%. It should be noted that visceral fat is about 43% of total visceral components for all weight classes with significant and positive correlation (r2 = 0.957*. The body composition showed significant differences with respect to ash: the highest value was found in the heaviest weight class. Although not significant, a tendency for higher fat accumulation in heavier fish was observed. The lipid content reflects a common feature in tropical fish species. From the analysis of the results, it is possible to conclude that crude protein and lipid were similar for all evaluated weight classes. Therefore, smaller fish may be processed while maintaining fillet yield.

  10. Stress responses of juvenile matrinxã (Brycon amazonicus after transport in a closed system under different loading densities Respostas de estresse de matrinxã (Brycon amazonicus juvenil após transporte em sistema fechado sob diferentes densidades de carga

    Directory of Open Access Journals (Sweden)

    Janessa Sampaio de Abreu

    2008-08-01

    Full Text Available Optimum loading density for the transport of matrinxã juveniles was investigated in a closed system with plastic bags. Transport was conducted for 4 h with fish (23.5± 0.4g and 11.6 (0.08cm starved for 24h at loading densities of 83g L-1 (D1, 125g L-1 (D2, 168g L-1 (D3 and 206g L-1 (D4. Fish were sampled before transport (BT, after transport (AT and 24h AT. The water quality was monitored before capturing fish in depuration tanks, after transport in plastic bags and in recovery tanks. Water oxygen decreased to values below 4mg L-1 in D2, D3 and D4, temperature was around 32°C, pH 6.5-6.78, total ammonia 1.09-1.7mg L-1, un-ionized ammonia 3.58-9.33x10³mg L-1 and alkalinity 134-165mg CaCO3 L-1. Blood cortisol and glucose concentrations increased in fish of all densities AT and recovered the BT levels 24h after arrival. Osmolality did not change AT but increased 24h AT in fish of all densities whereas plasma chloride decreased inversely to the loading densities after the procedure. Hematocrit decreased 24h AT in fish of all densities but no differences were verified in the number of erythrocytes. No mortality was registered in any treatment during the next week after transport. Matrinxã demonstrated to be a crowding tolerant-species in transport operations besides tolerating low levels of oxygen in the water.Neste estudo, foram investigadas as densidades de carga adequadas para transporte de matrinxãs juvenis em sistema fechado com sacos plásticos. O transporte de 4h foi feito com peixes (23,5±0,4g; 11,6 (0,08cm em jejum por 24h, em densidades de 83g L-1 (D1, 125g L-1 (D2, 168g L-1 (D3 e 206g L-1 (D4. Os peixes foram amostrados antes do transporte (AT, logo após o transporte (chegada (DT e 24h depois. A qualidade da água foi monitorada antes da captura dos peixes nos tanques de depuração, após o transporte nos sacos plásticos e nos tanques de recuperação. O oxigênio da água diminuiu para valores inferiores a 4mg L-1 em D2, D3 e D4, a temperatura esteve em torno de 32°C, pH 6,5-6,78, a amônia total foi de 1,09-1,7mg L-1, a amônia não-ionizada foi de 3,58-9,33 x 10³mg L-1 e alcalinidade 134-165mg CaCO3 L-1. O cortisol plasmático e a glicose sanguínea aumentaram após o transporte nos peixes em todas as densidades ensaiadas, voltando aos valores controle 24h depois. Os valores de osmolaridade não mudaram logo após o transporte, mas aumentaram 24h depois de modo igual em todas as densidades. O cloreto plasmático diminuiu na chegada, de modo inversamente proporcional à densidade de carga. O hematócrito diminuiu 24h depois da chegada dos peixes, em todas as densidades testadas, mas não houve diferença no número de eritrócitos. Não houve mortalidade até uma semana após o transporte. O matrinxã mostrou ser uma espécie tolerante a altas densidades de carga em embalagens para transporte além de suportar baixos níveis de oxigênio na água.

  11. Influence of the weight of juveniles Matrinxã (“Brycon cephalus” and Tambaqui (“Colossoma macropomum” to the anesthetic action of the eugenol Influência do peso de juvenis de matrinxã ("Brycon cephalus" e tambaqui ("Colossoma macropomum" à ação anestésica do eugenol

    Directory of Open Access Journals (Sweden)

    Elitieri Batista dos Santos Neto

    2007-10-01

    Full Text Available It was evaluated the influence of the weight in the effect of the anesthetic eugenol for juveniles of matrinxã and tambaqui. For that, it was used a total of 69 matrinxãs and 49 tambaquis. The animals were anesthetized individually, weighed and observed during the induction and the recover of the anesthesia. For the induction it was used the concentration of the anesthetic's 50 mg/L, previously diluted in alcohol. The obtained weights were gathered in five classes and no difference statistics was observed for the times of induction and recovery among them.Foi avaliada a influência do peso de juvenis de matrinxã e tambaqui sobre a ação do anestésico eugenol. Para isso, foram utilizados 69 matrinxãs e 49 tambaquis. Os animais foram individualmente anestesiados, pesados e observados durante a indução e a recuperação da anestesia. Para a indução foi utilizada a concentração de 50 mg/L do anestésico, previamente diluído em álcool. Os pesos obtidos foram reunidos em cinco classes, não sendo observada diferença estatística para os tempos de indução e de recuperação entre elas.

  12. Velocidade crítica de natação (Ucrit de matrinxã (Brycon amazonicus após exposição à hipoxia Critical swimming speed of matrinxã (Brycon amazonicus exposed to hypoxia

    Directory of Open Access Journals (Sweden)

    Marcio Soares Ferreira

    2010-12-01

    Full Text Available A primeira resposta ao estresse é a fuga, que depende do desempenho natatório e de ajustes fisiológicos. Este estudo investigou a velocidade crítica de natação (Ucrit de matrinxã após exposição à hipoxia. Para isso, os peixes foram expostos à hipoxia, sendo uma parte do grupo analisada antes e outra após natação forçada, por meio da Ucrit. A hipoxia resultou no aumento de lactato, glicose, cortisol e hematócrito. Mudanças nos níveis de sódio e potássio, bem como os valores de Ucrit não foram observadas. Sugere-se que o matrinxã seja sensível à hipoxia, mas os ajustes fisiológicos são suficientes para manter seu desempenho natatório.Escape is the first response of fish to stress, that depends on the swimming performance and the physiological adjustments. This study has investigated the critical swimming speed (Ucrit of matrinxã after exposure to hypoxia. To achieve that, the fishes were exposed to hypoxia and analyzed before and after forced swimming, using Ucrit. The hypoxia caused an increase of lactate, glucose, cortisol and hematocrit. No changes of plasma sodium and potassium levels, as well as the Ucrit, were observed. We suggest that matrinxã is sensitive to hypoxia, but the physiological adjustments are sufficient to keep its swimming performance.

  13. Geophysical monitoring of the EDZ during a gallery excavation in the Opalinus clay of the Mont Terri URL: design and principles of specific in situ experimental setups

    International Nuclear Information System (INIS)

    Gibert, D.; Maineult, A.; Kergosien, B.; Le Gonidec, Y.; Nicollin, F.; Sarout, J.; Wassermann, J.

    2012-01-01

    Document available in extended abstract form only. At the Mont Terri Underground Rock Laboratory, the gallery Ga08 was excavated in August 2008 to join the end-face of the pre-existing gallery Ga04. The Excavation Damaged Zone (EDZ) induced during the gallery construction was monitored from the instrumented face of Ga04. The EZ-G08 experiments required original acquisition setups, specifically designed to be installed in small boreholes and to ensure long term measurements. Different geophysical methods have been experimented for the EZ-G08 project and specific design of the experiments were required in order to coordinate multiple and simultaneous acquisitions, including acoustic emission (AE) acquisition setup (16 acoustic receivers), manufacturing of a combined electrical (256 electrodes) and acoustic tomography setup (64 receivers) to be introduced in horizontal boreholes with small diameters (56 mm), design of an acoustic source, design and manufacturing of a combined electrical tomography (64 lead electrodes) and self-potential measurements (64 un-polarizable electrodes). Other arrays of electrodes have also been placed at the end-face of Ga04 (715 inox electrodes and an array of 16 un-polarizable electrodes). The self-potential (SP) monitoring took place in the borehole BEZ-G5 equipped in mid- February 2008 with a specific device on which custom-made electrodes were fixed. To avoid polarisation effect and guaranty a satisfactorily signal-to-noise ratio, SP was measured with 64 un-polarizable electrodes, with an offset of 15 cm made of a metallic wire in chemical equilibrium with a surrounding solution containing a salt of the same metal. The electrical contact between the solution and the natural medium is ensured by a porous material. The electrodes were mounted upward on a half-cylinder fixed onto an inflatable pipe and introduced in BEZ-G5. The internal pipe was inflated to ensure a good electrical contact between the electrodes and the borehole wall. The combined electrical and seismic tomography setup consists in four arrays inserted into each small-diameter boreholes BEZ-G12:15. Specifically designed holding poles were made of two half cylinders with an inflatable membrane located between them: one half cylinder to hold the electrodes, while the other half was designed to hold the acoustic receivers. No interactions were observed between these two types of equipment during the experiment. The purpose of the inflatable membrane, pressurized with air at 1.4 bar, was to push the sensors against the borehole wall and to ensure a good coupling between each set of sensors and the borehole wall. On each holding pole, of 3.2 m in length, 16 piezo-ceramics with an offset of 20 cm were fixed on one side and on the other side, 64 lead electrodes were fixed with an offset of 5 cm. In order to measure acoustic surveys inside the rock mass, an active source was designed to be introduced in BEZ-G5: the omnidirectional source allowed to sound the medium with different travel paths to study the anisotropic structure of the rock. More than one month of measurements took place in boreholes BEZ-G12:15, both for the electrical and the acoustic acquisition, which produced a very large data base. (authors)

  14. Notes on Gobioid fishes : 6. On the synonymy of some species from the Indo-Australian Archipelago

    NARCIS (Netherlands)

    Koumans, F.P.

    1935-01-01

    Bathygobius fuscus (Rüpp.) Gobius fuscus Rüppell, Atl. Reise N. Afr. Fische 1828, p. 137. Gobius punctillatus Rüppell, l.c., p. 138. Gobius soporator Cuvier & Valenciennes, Hist. Nat. Poissons XII. 1837, p. 56. Gobius albopunctatus Cuvier & Valenciennes, l.c., p. 57. Gobius nebulopunctatus Cuvier &

  15. Sharks caught in the KwaZulu-Natal bather protection programme ...

    African Journals Online (AJOL)

    The current study provides long-term catch rate and biological data for tiger sharks Galeocerdo cuvier caught in the KwaZulu-Natal bather protection programme. Between 1978 and 2014, 1 760 G. cuvier were caught in nets and between 2007 and 2014, 108 G. cuvier were caught on drumlines. Standardised catch rates ...

  16. Calcium and phosphorus determination in bones of low value fishes, Sardinella longiceps (Valenciennes and Trichiurus savala (Cuvier, from Parangipettai, Southeast Coast of India

    Directory of Open Access Journals (Sweden)

    Logesh AR

    2012-05-01

    Full Text Available Objective: To investigate calcium and phosphorus levels in the bones of low value fishes Sardinella longiceps (oil sardine and Trichiurus savala (ribbon fish. Methods: Bones and skeletal remains were subjected to alkaline-alcohol treatment for specified period of time and were then dried and pulverized. Calcium and phosphorus levels were determined by both volumetric and instrumental methods using atomic absorption spectroscopy. Results: Volumetric analysis of calcium and phosphorus were 28.98% and 14.2% in oil sardine; 24.2% and 11.6% in ribbon fish respectively. Atomic absorption spectroscopy analysis of calcium and phosphorus were 32.73% and 17.2% for oil sardine and 27.17% and 10.83% for ribbon fish respectively. Protein level was 4.82% in oil sardine and 3.97% in ribbon fishes. Conclusions: The findings of the present study revealed that sardine bones are rich in calcium and will be utilized for the production of calcium powder to treat osteoporosis.

  17. 3D Reconstruction of the Digestive System in Octopus vulgaris Cuvier, 1797 Embryos and Paralarvae during the First Month of Life

    Directory of Open Access Journals (Sweden)

    Raquel Fernández-Gago

    2017-07-01

    Full Text Available Octopus vulgaris aquaculture is limited due to poor biological knowledge of the paralarval stages (e.g., digestive system functionality, their nutritional requirements (e.g., adequate live diet and standardization of rearing techniques. These factors are important in explaining the high mortality rate observed in this developmental stage under culture conditions. For a better understanding of nutrition biology of this species, we investigated the 3D microanatomy of the digestive tract of the embryo and paralarvae during the first month of life. O. vulgaris paralarvae digestive system is similar to that in the adult. The “descending branch” has a dorsal position and is formed by the buccal mass, oesophagus and crop. Ventrally, the “ascending branch” is formed by the intestine and the anus. The digestive gland, the posterior salivary glands and the inner yolk sac (in the case of the embryo and hatched paralarvae are located between the “ascending” and “descending” branches. In the curve of the U-shaped digestive tract, a caecum and the stomach can be found. The reconstructions reveal that anatomically the digestive system is already complete when the paralarvae hatch. The reconstruction of the buccal mass at different post-hatching days has demonstrated that all the necessary structures for food intake are present. However, the radula surface in contact with the pharynx is very small on the first day of life. Although the digestive system has all the structures to feed, the digestive gland and radula take longer to reach full functionality. We have established four development periods: embryonic, early post-hatching, late post-hatching and juvenile-adult. The differentiation between these periods was done by type of feeding (endogenous or exogenous, the state of maturation and hence functionality of the digestive gland, type of growth (linear, no net, or exponential, and measurement of the arm lengths with respect to the mantle length. 3D reconstruction represents a new tool to study the morphology and functionality of the cephalopod digestive system during the first days of life.

  18. Helmintos parasitos das espécies Scomberomorus cavalla (Cuvier e Scomberomorus maculatus (Mitchill do litoral cearense: Contracaecum fortalezae sp. n. (Nematoda, Ascaridoidea

    Directory of Open Access Journals (Sweden)

    Vera Lucia M. Klein

    1973-01-01

    Full Text Available De nematódeos encontrados parasitando estômago, intestinos delgado e grosso de Scomberomorus cavalla (Cuv. e Scomberomorus maculatus (Mitch. o autor propões para o gênero Contracaecum Railliet et Henry, 1912 uma nova espécie, C. fortalezae sp. n., que mais se aproxima de C. clavatum (Rud., 1809 Baylis, 1920 dela se diferenciando por possuir espículos desiguais, um curto ovejetor, útero opistodelfo, ovos menores e por apresentar em todos exemplares estudados ceco intestinal curto e ceco esofagiano longo.In this paper the author proposes a new species of the genus Contracaecum Railliet et Henry, 1912. Of the species under Contracaecum, Contracaecum clavatum (Rudolphi, 1809 Baylis, 1920 is the nearest to Contracaecum fortalezae sp. n. differing from the latter by the following aspects: The males have unequal spicules. The females have a short ovijector and parallel uteri directed backward and the eggs are smaller. In both sexes the intestinal cecum is always short and the ventricular posterior appendix is always long, while Contracaecum clavatum presents these structures in an inverse way, considering the lenght of them. Besides, the thorn-like formations at the posterior end of the body are different.

  19. Growth and survival of Octopus vulgaris (Cuvier 1797 paralarvae fed on three Artemia-based diets complemented with frozen fish flakes, crushed zooplankton and marine microalgae

    Directory of Open Access Journals (Sweden)

    Lidia Fuentes

    2011-07-01

    Full Text Available During one month, paralarvae of common octopus (Octopus vulgaris were fed 3 different diets: (1 Artemia sp. enriched with Isochrysis galbana (AI complemented with sand eel (Hyperoplus lanceolatus flakes (AH; (2 Artemia sp. enriched with crushed marine zooplankton (AZ; and (3 Artemia sp. cultured with Isochrysis galbana and further enriched with the microalga Nannochloropsis sp. (AN. The highest dry weight (1.6179±0.3861 mg was registered with the AN diet and the best average survival (67.0% with the AZ diet. Considering the highest dry weight obtained, the moderate high survival and the fact that with this diet it was possible to attain the adult stage, the AN diet was the most appropriate. The reasons for the best result in growth observed with AN are discussed as: (1 the combination of docosahexaenoic acid (DHA provided by Isochrysis galbana and the high eicosapentaenoic acid (EPA content present in Nannochloropsis sp.; (2 the fact that the higher protein/lipid ratio of this diet improves the final dry weight of the paralarvae; and (3 the fact that Nannochloropsis sp. could inhibit the harmful microflora growth in the rearing tank. Regarding nutritional aspects, DHA content per se is not the only determinant factor for growth and survival of O. vulgaris paralarvae, but the presence of a high protein/lipid ratio and a high phospholipid content in the diet could possibly explain the better quality and strength of the paralarvae.

  20. The growth and exploitation rate of yellowstripe scad (selaroides leptolepis cuvier, 1833) in the Malacca Strait, Medan Belawan Subdistrict, North Sumatera Province

    Science.gov (United States)

    Tambun, J.; Bakti, D.; Desrita

    2018-02-01

    Yellowstripe scad included the one of commodity that has an important economic value in the Malacca Strait. Fish were found mostly in Indonesian of waters made this fish as one of the main target catch. But, it can had negative impact on the population of the fish. The study is done at Belawan Waters on March until May 2017 that which is purposed to study about the frequency distribution of length, determine the parameters of growth and, determine mortality rate and the rate of exploitation in order to provide appropriate management model for the fish resource. Yellowstripe scad was observed around 360 samples with the length range between 110 - 175 mm. The fish separated by bhattacarya method used the aid software FISAT II. A pattern of growth Yellowstripe scad alometrik negative with growth coefisien (K) 1.1 with length asimtotic (L∞) 181.65. The rate of mortality total ( Z) yellowstripe scad 4.34 per year at the rate of mortality natural ( M ) 1.204 per year and rate mortality by fishing (F) 3.136 per year in order to obtain the rate of exploitation 0.722. The value of this exploitation rate has exceeded the value of the optimum exploitation of 0.5.

  1. Avances en el conocimiento y el estado actual de conservación del Cocodrilo de Tumbes (Crocodylus acutus Cuvier, 1807

    Directory of Open Access Journals (Sweden)

    Armando H. Escobedo Galván

    2013-06-01

    Full Text Available En esta nota se describe el estado de conservación del Cocodrilo de Tumbes en Perú, donde la especie encuentra su límite sur de distribución, por lo que es catalogada como especie rara en la zona. Esto ha generado que se lleven a cabo programas de manejo ex situ para apoyar su conservación. Sin embargo el desconocimiento de los beneficios que brinda la especie, junto con la deforestación, el cambio climático y las actividades antropogénicas, han ocasionado que su población disminuya y se encuentre amenazada.

  2. Dynamics and cytochemistry of oogenesis in Astyanax fasciatus (Cuvier (Teleostei, Characiformes, Characidae from Rio Sapucaí, Minas Gerais State, Brazil

    Directory of Open Access Journals (Sweden)

    José Antônio Dias Garcia

    2001-12-01

    Full Text Available Oogenesis involves a set of transformations which are undergone by female germ cells These cells change into oogonias and then into mature oocytes. Sexually mature female fish were collected monthly, during one year, from the Sapucaí River, a tributary of the Rio Grande, which is part of the Furnas Reservoir in the state of Minas Gerais. During the several stages of maturation, we observed small round oogonias with a large nucleus, a single nucleolus, and weakly stained cytoplasm with eosinophilic granules. The primary oocytes showed a large basophilic nucleus, with a developed peripheral nucleolus and a reduced cytoplasm. The previtellogenic oocytes presented voluminous cytoplasm and nucleus with several small peripheral nucleoli. The oocytes underwent vitellogenesis with the development of the zona radiata and the follicle cells. Their cytochemical reactions indicated that the two layers of the zona radiata of A. fasciatus contained proteins and polysaccharides. The initially squamous follicle cells, became cuboidal. In mature oocytes, the nucleus moved toward the periphery, next to the micropyle, and the yolk granules formed by proteins, fulfilled the cytoplasm. The clear unstained vesicles are likely to be the cortical alveoli in the perivitelline region.

  3. Molecular diagnosis of the arowanas Osteoglossum ferreirai Kanazawa, 1966 and O. bicirrhossum (Cuvier, 1829 from the Orinoco and Amazon River basins

    Directory of Open Access Journals (Sweden)

    Maria Doris Escobar L.

    Full Text Available The arowanas, fishes of Gondwanan origin, are represented in South America by the genus Osteoglossum. All species were initially reported as being exclusive to the Amazon region, with O. ferreirai restricted to the Negro River basin and O. bicirrhosum to the Amazon and Essequibo Rivers basin. Starting in the mid 1970's it was reported that O. ferreirai also occurs in the Orinoco River basin. In all regions the arowanas assumed significant socio-economic importance due to their popularity in the international ornamental fish trade, leading to over-exploitation of both species in some areas. The Orinoco populations are particularly heavily exploited, and thus conservation and management measures are needed. Both depend on the clarification of taxonomic status, and phylogenetic distinctness of the Orinoco populations. With the goal of molecularly characterizing the two species of Osteoglossum, and comparing populations of Osteoglossum from the Orinoco and Amazon basins, we characterized individuals sampled from eight localities, one in the Orinoco River basin and seven in the Amazon River basin. We sampled 39 individuals, obtaining 1004 base pairs, of which 79 were synapomorphies. Genetic distance between the two species calculated using the HKY + G model of molecular evolution was 8.94%. Intraspecific distances ranged from 0.42% in O. bicirrhosum to 0.10% in O. ferreirai. The genetic characterization confirmed the taxonomic status of O. ferreirai in the Orinoco basin, and suggested that its distribution in the Orinoco basin is unlikely to be the result of vicariance or natural dispersal, but rather an anthropic introduction.

  4. Feeding of Oligosarcus hepsetus (Cuvier, 1829 (Characiformes in the Serra do Mar State Park - Santa Virgínia Unit, São Paulo, Brazil

    Directory of Open Access Journals (Sweden)

    MLLA Botelho

    Full Text Available We describe the diet of Oligosarcus hepsetus, in the Santa Virgínia Unit of the Serra do Mar State Park. The Paraibuna and Grande rivers in the basin of the Paraíba do Sul River were sampled monthly from January to December 2004. The Alimentary Preference Degree and the frequency of occurrence indices were used to analyze the food items. The diets of Oligosarcus hepsetus in the two localities sampled were very similar, and reinforced the importance of the streamside forests in establishing and maintaining biotic and abiotic conditions in these environments. The species had a carnivorous diet that differed with ontogeny: smaller individuals were principally insectivorous and larger ones ichthyophagous.

  5. 3D Reconstruction of the Digestive System in Octopus vulgaris Cuvier, 1797 Embryos and Paralarvae during the First Month of Life.

    Science.gov (United States)

    Fernández-Gago, Raquel; Heß, Martin; Gensler, Heidemarie; Rocha, Francisco

    2017-01-01

    Octopus vulgaris aquaculture is limited due to poor biological knowledge of the paralarval stages (e.g., digestive system functionality), their nutritional requirements (e.g., adequate live diet) and standardization of rearing techniques. These factors are important in explaining the high mortality rate observed in this developmental stage under culture conditions. For a better understanding of nutrition biology of this species, we investigated the 3D microanatomy of the digestive tract of the embryo and paralarvae during the first month of life. O. vulgaris paralarvae digestive system is similar to that in the adult. The "descending branch" has a dorsal position and is formed by the buccal mass, oesophagus and crop. Ventrally, the "ascending branch" is formed by the intestine and the anus. The digestive gland, the posterior salivary glands and the inner yolk sac (in the case of the embryo and hatched paralarvae) are located between the "ascending" and "descending" branches. In the curve of the U-shaped digestive tract, a caecum and the stomach can be found. The reconstructions reveal that anatomically the digestive system is already complete when the paralarvae hatch. The reconstruction of the buccal mass at different post-hatching days has demonstrated that all the necessary structures for food intake are present. However, the radula surface in contact with the pharynx is very small on the first day of life. Although the digestive system has all the structures to feed, the digestive gland and radula take longer to reach full functionality. We have established four development periods: embryonic, early post-hatching, late post-hatching and juvenile-adult. The differentiation between these periods was done by type of feeding (endogenous or exogenous), the state of maturation and hence functionality of the digestive gland, type of growth (linear, no net, or exponential), and measurement of the arm lengths with respect to the mantle length. 3D reconstruction represents a new tool to study the morphology and functionality of the cephalopod digestive system during the first days of life.

  6. Identification of a Δ5-like fatty acyl desaturase from the cephalopod Octopus vulgaris (Cuvier 1797) involved in the biosynthesis of essential fatty acids.

    Science.gov (United States)

    Monroig, Oscar; Navarro, Juan C; Dick, James R; Alemany, Frederic; Tocher, Douglas R

    2012-08-01

    Long-chain polyunsaturated fatty acids (LC-PUFA) have been identified as essential compounds for common octopus (Octopus vulgaris), but precise dietary requirements have not been determined due, in part, to the inherent difficulties of performing feeding trials on paralarvae. Our objective is to establish the essential fatty acid (EFA) requirements for paralarval stages of the common octopus through characterisation of the enzymes of endogenous LC-PUFA biosynthetic pathways. In this study, we isolated a cDNA with high homology to fatty acyl desaturases (Fad). Functional characterisation in recombinant yeast showed that the octopus Fad exhibited Δ5-desaturation activity towards saturated and polyunsaturated fatty acyl substrates. Thus, it efficiently converted the yeast's endogenous 16:0 and 18:0 to 16:1n-11 and 18:1n-13, respectively, and desaturated exogenously added PUFA substrates 20:4n-3 and 20:3n-6 to 20:5n-3 (EPA) and 20:4n-6 (ARA), respectively. Although the Δ5 Fad enables common octopus to produce EPA and ARA, the low availability of its adequate substrates 20:4n-3 and 20:3n-6, either in the diet or by limited endogenous synthesis from C(18) PUFA, might indicate that EPA and ARA are indeed EFA for this species. Interestingly, the octopus Δ5 Fad can also participate in the biosynthesis of non-methylene-interrupted FA, PUFA that are generally uncommon in vertebrates but have been found previously in marine invertebrates, including molluscs, and now also confirmed to be present in specific tissues of common octopus.

  7. Growth of Octopus vulgaris (Cuvier, 1797 in tanks in the Ebro Delta (NE Spain: effects of temperature, salinity and culture density

    Directory of Open Access Journals (Sweden)

    Marina Delgado

    2010-11-01

    Full Text Available To assess the possibility of O. vulgaris ongrowing using tanks or cages in the bays of the Ebro Delta, we performed several growth trials of common octopus held in tanks. Effects of environmental factors (temperature and salinity and zootechnical aspects (culture density were studied. The thermal ranges that defined positive growth periods in the bays of the Ebro Delta were 19.5ºC to 23ºC (spring-summer and 23.5ºC to 12.3ºC (autumn-winter, the latter being the most suitable period for ongrowing. Salinity did not affect survival (100% or growth within the range tested (34-29 psu, though feeding rates (AFR, SFR were directly related to salinity. On the other hand, after 60 days, final culture density increased three-fold (D1: 12.36 → 44.37 kg m–3; D2: 24.13 → 67.76 kg m–3, with optimal survival results ( > 90% for the two densities tested. Growth and feeding rates showed a slight inverse relationship with density. Finally, growth and feeding rates showed a clear dependence on temperature in the two experiments (density and salinity. Our results conclude that industrial production of O. vulgaris in tanks is promising: this system offers an alternative to cages and allows for a more exhaustive control of culture.

  8. Allometric variation among juvenile, adult male and female eastern bearded dragons Pogona barbata (Cuvier, 1829), with comments on the behavioural implications.

    Science.gov (United States)

    Wotherspoon, Danny; Burgin, Shelley

    2011-02-01

    The functional significance of allometric change in reptiles has received limited attention and the reason for such changes has been regarded as 'obscure'. In this paper we report data on the Australian Pogona barbata, the eastern bearded dragon, from across their range and review changes in allometric growth among juveniles, and adult males and females and consider the functional relevance of these changes. There were significant differences in the population for mass, tail length, tail width, rear leg length and jaw length. These differences were consistent with differences required in locomotor performance and thus habitat use, together with access to different preferred dietary components. Crown Copyright © 2011. Published by Elsevier GmbH. All rights reserved.

  9. Macro and microscopic structure of parotids salivary glands in two species of procyonidae: raccoon (Procyon cancrivorus, G. Cuvier, 1798 and coati (Nasua nasua, Linnaeus, 1766

    Directory of Open Access Journals (Sweden)

    Celina Almeida Furlanetto Mançanares

    2012-03-01

    Full Text Available Coati (Nasua nasua, a diurnal animal, and raccoon (Procyon cancrivorus, a crepuscular and nocturnal one, are species of terrestrial mammals, belonging to the procyonidae family, that are widely found in the Brazilian territory. For this work were used three adult coatis and two adult raccoons adults from the Scientific Breeding-Cecrimpas of Centro Universitario da Fundacão de Ensino Octávio Bastos (Ibama 02027.003731/04-76 were used, from which tissue samples of parotid salivary glands were obtained and stained H.E. for light microscopy. It was found that the parotid glands of coatis and raccoons has a positioning similar to that of the other domestic carnivores, opening their ducts within the oral cavity close to the fourth upper premolar tooth, as well as that histologically the parotid glands of coatis and raccoons are formed by serous acini, similarly to most of the domestic animals, humans beings and rodents, and differently from the results found in young dogs, lambs and some carnivores such as the ferret which have mixed acini and other ones which have serous. One concludes that the similarity in serous constitution of the parotid glands of coatis and raccoons might be due to the omnivorous feeding habit shared by these two species.

  10. Histopathological study of lymphocystis disease virus (LCDV in cultured false clownfish, Amphiprion ocellaris (Cuvier, 1830 and true clownfish, Amphiprion percula (Lacepede, 1802

    Directory of Open Access Journals (Sweden)

    Muthuramalingam Uthaya Siva

    2014-04-01

    Full Text Available Objective: To study the lymphocystis disease virus (LCDV in two species of marine ornamental fishes through histopathological investigation along with control for differentiating the tissue damage. Methods: Six naturally infected fishes were collected. They were anaesthetized and subsequently killed by organ dissection. The infected fish organs were aseptically cut off and stored with 10% formalin solution for histological study. Samples were examined for gross pathology including location, distribution, shape, size, colour, consistency and special features of typical external lesions by standard method. Results: The diameter of the tumor nodules ranged from 1 to 2 mm (Amphiprion ocellaris and 2.5 to 3.5 mm (Amphiprion percula. Light microscopic observation showed over growth of tumor like nodules on the skin or scales and ventral side as well. Numerous hypertrophied cells with basophilic intracytoplasmic inclusion bodies were in the connective tissues of dermis and between scales on two species. The nucleus of lymphocystis cell were enlarged, irregular and containing basophilic marginated chromatin. Thus, the similarities among cellular patterns of different fish LCDV isolates from different hosts indicated that these profiles do not depend on the host species. Conclusions: In conclusion, this current study of histopathological statement of LCDV may be adequate for a presumptive diagnosis of lymphocystis disease from both marine as well as fresh water fish species. The findings of asymptomatic carriers by histology using infected skin and fin sampling, which does not imply animal killing, could be important tool to epizootics caused by LCDV. This study may be very useful for further molecular studies.

  11. Philometra johnii sp nov (Nematoda, Philometridae), a new gonad-infecting philometrid from the sin croaker Johnius dussumieri (Cuvier) (Perciformes, Sciaenidae) from marine waters of Iraq

    Czech Academy of Sciences Publication Activity Database

    Moravec, František; Ali, A. H.

    2013-01-01

    Roč. 58, č. 3 (2013), s. 263-268 ISSN 1230-2821 R&D Projects: GA ČR GBP505/12/G112 Institutional support: RVO:60077344 Keywords : Parasitic nematode * Philometra * new species * marine fish * Johnius * Iraq * Arabian Gulf Subject RIV: EA - Cell Biology Impact factor: 0.965, year: 2013

  12. HÁBITOS ALIMENTICIOS DE LA ARAHUANA Osteoglossum bicirrhosum (CUVIER, 1829 EN LA CUENCA MEDIO DEL RÍO PUTUMAYO - EL ESTRECHO, LORETO, PERÚ

    Directory of Open Access Journals (Sweden)

    Bray Torres Del Castillo

    2012-06-01

    Full Text Available El objetivo del presente trabajo fue estudiar los hábitos alimenticios de la arahuana Osteoglossum bicirrhosum en la cuenca media del río Putumayo. Para tal fin, fueron colectados un total de 222 estómagos de especímenes de varias tallas, durante el período de un año, iniciándose en marzo de 2008 y concluyendo en abril de 2009. El análisis del contenido estomacal determinó que el 73% de los estómagos contenían alimento y el 27% no. Mediante el uso del índice de importancia alimenticia (IAi, y el coeficiente alimenticio (Q, se observó una preferencia por los insectos, peces y moluscos, siendo las aves, mamíferos y restos vegetales alimentos secundarios. No se registraron diferencias significativas en el consumo de alimento de acuerdo al régimen hidrológico (p>0.05 ni al sexo (p>0.05. El análisis del IAi y Q, nos indica que el consumo de insectos presenta una relación inversa a los rangos de talla, es decir, a mayor nivel de talla menor consumo de insectos. En contraste, el consumo de peces se incrementó con el tamaño de los ejemplares de arahuana. En conclusión, la arahuana, en el rango de talla estudiado (de 31 a 87 cm, presenta un comportamiento alimenticio generalista y oportunista, de régimen omnívoro con fuerte tendencia a la carnivoría.

  13. Caracterização genética do pirarucu Arapaima gigas (Cuvier) (Teleostei, Osteoglossidae) da bacia Tocantins-Araguaia, estado do Mato Grosso.

    OpenAIRE

    Débora Karla Silvestre Marques

    2003-01-01

    Os Osteoglossiformes são representados na América do Sul pelos gêneros Arapaima e Osteoglossum, que ocorrem particularmente na região Amazônica, nas bacias Amazônica e Tocantins-Araguaia. Os estudos genéticos neste grupo são praticamente inexistentes, evidenciando a necessidade de informações para programas de conservação. A espécie Arapaima gigas da bacia hidrográfica Tocantins-Araguaia apresentou um 2n=56 cromossomos, com fórmula cariotípica 28M/SM+28ST/ A. A marcação por nitrato de p...

  14. Tongue anato-histology of the oceanodromous adult Rastrelliger brachysoma (Bleeker, 1851 with a note on the comparison with the tongue structure of adult R. kanagurta (Cuvier, 1816

    Directory of Open Access Journals (Sweden)

    Jes Kettratad

    2017-02-01

    Full Text Available Anatomical and histological structures of the tongue tissue of Rastrelliger brachysoma and R. kanagurta were investigated. Anatomical structure of the tongue in R. brachysoma was poorly developed and was of triangular shape. The histological and histochemical technique showed the tissue to be principally composed of three layers: tunica mucosa, tunica submucosa and osteocartilagionous skeleton. Stratified epithelium of its mucosal surface was interrupted with several cell types including goblet cells and taste buds. Numerous teeth with elongated shape were also found centrally on the anterior tip of the tongue. They are found among a few dermal papillae of the tongue. Tunica submucosa consisted of connective tissue, blood vessels and pigment cells. When compared anatomically and histologically with that of R. kanagurta, the overall morphological was quite similar. However, some histological structures including taste buds and teeth of R. kanagurta were rarely seen. Rastrelliger kanagurta also tended to have more goblet cell than R. brachysoma. Rastrelliger kanagurta tended to possess less overall histological structures of the tongue. This difference could potentially cause by different feeding adaptation between the two species. Regardless of the differences found between the two species, both are still considered as herbivores.

  15. Suplementação de metionina e/ou lisina em rações para juvenis de tambaqui (Colossoma macropomum Cuvier, 1818 Reduction of protein levels and methionine and/or lysine supplementation in diets and their effects in total ammonia nitrogen excretion of tambaqui juveniles (Colossoma macropomum Cuvier, 1818

    Directory of Open Access Journals (Sweden)

    Lian V. Brandão

    2009-09-01

    Full Text Available Foi avaliado o efeito da redução dos níveis de proteína e a suplementação de metionina e/ou lisina em rações sobre a excreção de amônia em juvenis de tambaqui (Colossoma macropomum. O experimento foi realizado em delineamento inteiramente casualizado com esquema fatorial de duas entradas: 2 níveis protéicos (25 e 20% e 4 níveis de inclusão de aminoácidos: a 0% de suplementação, b DL-Metionina (3% da PB, c L-lisina (5% da PB e d Dl-Metionina (3% da PB + L-lisina (5% da PB, com duração de 55 dias. A coleta de água das unidades experimentais ocorreu em três momentos (1º dia, 27º dia e 55º dia durante o período experimental. Nestes dias, foram realizadas 3 coletas de amostras de água para análise de amônia de cada unidade experimental (08:00 , 14:00 e 20:00 horas. Os dados de excreção de amônia foram analisados por ANOVA com medidas repetidas no tempo a 5% do nível de significância. A redução em 5% do nível de proteína na dieta gerou uma diminuição de 28,4% na excreção de amônia. Contudo, a suplementação de lisina e metionina não influenciaram esta diminuição.It was evaluated the effect of the reduction of crude protein level (CP and the lysine and/or methionine supplementation in total ammonia nitrogen excretion on tambaqui (Colossoma macropomum juveniles. The experiment developed in a factorial and randomized design with two levels of protein contents (20% and 25% CP and four levels of amino acid supplementation: a Dl-methionine (0% of CP and L-lysine (0% of CP, b Dl-methionine (3% of CP, c L-lysine (5% of CP, d Dl-methionine (3% of CP + L-lysine (5% of CP, during 55 days. The water sampling from experimental units was done at 3 moments (1(0 day, 27(0 day e 55(0 day. In these days, 3 samples of each experimental unit were collected in elapsing of the time (08:00 a.m., 02:00 p.m. and 08:00 p.m.. The ammonia excretion data were analysed by repeated-measures ANOVA (p>0,05 with time as within effect. The reduction of 5% in diet protein, decreased in 28,4% total ammonia excretion decreased, however, the lysine and methionine supplementation did not influenced this factor.

  16. Morfologia e crescimento do músculo estriado esquelético no pirarucu Arapaima gigas Cuvier, 1817 (Teleostei, Arapaimidae - DOI: 10.4025/actascibiolsci.v30i2.3640 Morphology and skeletal muscle growth in pirarucu Arapaima gigas Cuvier, 1817 (Teleostei, Arapaimidae - DOI: 10.4025/actascibiolsci.v30i3.3640

    Directory of Open Access Journals (Sweden)

    Maeli Dal Pai Silva

    2008-05-01

    Full Text Available O objetivo deste trabalho foi avaliar as características morfológicas e de crescimento do músculo estriado esquelético no pirarucu (Arapaima gigas. Foram utilizados animais em duas fases de crescimento: alevinos, com 50 dias de idade, e juvenis, com um ano de idade. Após eutanásia dos animais, fragmentos musculares das regiões dorsal, lateral cranial e lateral caudal foram coletados e congelados em nitrogênio líquido. Cortes histológicos (10 µm foram submetidos às colorações HE e Tricrômico de Gomori, para a análise morfológica, e NADH-TR, para a análise do metabolismo oxidativo das fibras musculares. Foi calculado o menor diâmetro das fibras musculares brancas nas regiões dorsal e lateral cranial. A musculatura dorsal branca mostrou-se mais desenvolvida e, na musculatura lateral, observaram-se compartimentos distintos: superficial vermelho e profundo branco. Nos alevinos, o crescimento muscular ocorreu predominantemente por hiperplasia das fibras e, nos juvenis, predominou o crescimento muscular por hipertrofia.The aim of this work was to evaluate the morphological and growth characteristics of skeletal muscle tissue in pirarucu (Arapaima gigas using alevins (50 days old and juveniles (1 year old. Muscle samples were collected from dorsal, lateral cranial, and lateral caudal regions, and then frozen in liquid nitrogen. Histological frozen sections (10 µm were stained with HE and Gomori Trichrome for morphological analysis, and NADH-TR to evaluate muscle fiber oxidative metabolism. Morphometric analysis samples were obtained from dorsal and lateral cranial regions, and smallest diameter white fibers were measured. White dorsal muscle was thicker and two muscle fiber compartments were identified in the lateral cranial region: red (superficial and white (deep muscle. Hyperplasia muscle growth predominated in alevins and hypertrophy in juveniles.

  17. Desempenho produtivo de juvenis de tambaqui (Colossoma macropomum Cuvier, 1818 alimentados com rações contendo farinha de crueira de mandioca (Manihot esculenta, Crantz em substituição ao milho (Zea mays Performance of juvenile tambaqui (Colossoma macropomum Cuvier, 1818 fed diets containing crueira manioc flour (Manihot esculenta, Crantz in replacement of corn (Zea mays

    Directory of Open Access Journals (Sweden)

    Geraldo Pereira Pereira Junior

    2013-06-01

    Full Text Available O objetivo deste estudo foi avaliar o desempenho produtivo de juvenis de tambaqui (Colossoma macropomum, alimentados com níveis crescentes de farinha de crueira de mandioca, Manihot esculenta (0%, 20%, 40%, 60%, 80%, 100%, como substituto do milho (Zea mays. Os peixes (peso médio inicial de 6,6 ± 0,1 g foram distribuídos aleatoriamente em 24 grupos (20 peixes/grupo e alimentados com as dietas experimentais em quatro repetições para avaliação da performance de crescimento, eficiência alimentar, composição corporal e os custos de produção. As performances de crescimento não foram afetados pelos tratamentos. O teor de lipídio no músculo foi diferentemente significativo em peixes alimentados com 40% e 100% em relação aos outros tratamentos. O custo de produção de milho diminuiu linearmente com a substituição. O valor da dieta diminuiu de R $ 1,43 kg-1 a R $ 1,21 kg-1 e o peixe de R $ 1,54 kg-1 a R $ 1,30 peixe kg-1. Concluiu-se que o milho pode ser totalmente substituído por farinha de crueira de mandioca na dieta de juvenil de tambaqui, sem prejudicar o seu desempenho.The main objective of this study was to evaluate the productive performance of young tambaqui (Colossoma macropum, fed with increasing levels of cassava flour, Manihot esculenta (0%, 20%, 40%, 60%, 80%, 100%, as corn (Zea mays replacement. Fish (initial body weight 6.6 ± 0.1 g were randomly distributed in 24 groups (20 fish/group with four replications. They were fed with the experimental diets for evaluation of growth performances, feed utilization, body composition and production costs. Growth performances were not affected by the dietary treatments. Lipid content in muscle were significant different in fish fed 40% and 100% substitution when compared to the other treatments. The production cost decreased linearly with corn substitution. Diet decreased from R$ 1.43 kg-1 to R$ 1.21 kg-1 and fish production cost from R$ 1.54 kg-1 to R$ 1.30 kg-1 fish. It was concluded that the corn can be totally replaced by cassava flour in juvenile tambaqui diet without adversely affecting the performance of tambaqui.

  18. Farinha de folha de leucena (Leucaena leucocephala Lam. de wit como fonte de proteína para juvenis de tambaqui (Colossoma macropomum CUVIER, 1818 Leucaena leaf flour (Leucaena leucocephala Lam. of wit as a protein source for juveniles of tambaqui (Colossoma macropomum Cuvier, 1818

    Directory of Open Access Journals (Sweden)

    Geraldo Pereira Junior

    2013-06-01

    Full Text Available O tambaqui (Colossoma macropomum é um peixe onívoro, natural da bacia amazônica, que possui elevado valor comercial. Características de rusticidade e desempenho produtivo destacam esta espécie para criação em cativeiro. Contudo, em criações comerciais de peixes, os custos com alimentação podem corresponder de 60 a 80% dos custos totais de produção, sendo a proteína o nutriente mais caro da dieta. O objetivo deste trabalho foi avaliar o desempenho produtivo de juvenis de tambaqui alimentados com rações contendo farinha de folha de leucena como fonte protéica. 240 juvenis foram distribuídos em 12 aquários experimentais (350 L, em um delineamento experimental inteiramente casualizado com quatro tratamentos (0%, 8%, 16%, 24% de inclusão de farinha de folha de leucena na ração e três repetições. Foram determinados o ganho de peso, conversão alimentar aparente, taxa de crescimento específico, taxa de eficiência protéica e custo de produção do quilograma de peso vivo ganho. Para as variáveis estudadas, não houve diferença significativa (p>0,05 entre os tratamentos, indicando que é possível incluir até 24% de farinha de folha de leucena em rações para juvenis de tambaqui, sem comprometimento das variáveis estudadas, embora a substituição não tenha representado redução no custo de produção do quilograma de peixe.The tambaqui (Colossoma macropomum is an omnivorous fish native to the Amazon basin, which has high commercial value. Characteristics of rusticity and desirable growth in farming highlight this species for breeding in captivity. However, in commercial fish breeding, feed costs may represent 60-80% of total costs of production, being the protein the most expensive nutrient in the diet. The objective of this study was to evaluate the growth of juvenile tambaqui fed with diets containing leucaena leaf flour as protein source. A total of 240 juveniles were distributed in 12 experimental aquaria (350 L in a completely randomized design with four treatments (0%, 8%, 16%, 24% of inclusion of leucaena leaf flour in diet and three replications. Weight gain, feed conversion ratio, specific growth rate, protein efficiency rate and cost of production per kilogram of live weight gained were calculated. For the studied variables, there was no significant difference (p> 0.05 among treatments, indicating that it is possible to include up to 24% of leucaena leaf flour in diets for juveniles of tambaqui, without compromising the variables studied, although the replacement has not represented reduction in cost of production per kilogram of fish.

  19. Tempo de indução e de recuperação de dourados Salminus brasiliensis (Cuvier, 1816, submetidos a diferentes concentrações de óleo de cravo Eugenia sp. = Induction and recovery time for dourados Salminus brasiliensis (Cuvier, 1816 submitted to different concentrations of clove oil Eugenia sp.

    Directory of Open Access Journals (Sweden)

    2008-07-01

    Full Text Available O presente estudo avaliou o óleo de cravo como anestésico para juvenis de dourado em cinco diferentes concentrações (20, 30, 40, 50 e 60 mg L-1, utilizando como critério para determinação da concentração ideal os tempos de indução e de recuperação ao efeito do anestésico. Em relação aos tempos de indução, verificou-se diferença significativa (p The present study evaluated five different concentrations (20, 30, 40, 50 and 60 mg L-1 of clove oil as an anesthetic for dourado juveniles, using induction and recovery time to determine the ideal concentration. Significant difference (p < 0.05 was observed among 20, 30, 40 and 60 mg L-1 levels of clove oil. However, 50 mg L-1 concentrati on did not show significant difference in comparison to 40 and 60 mg L-1. Regarding recovery time, the shortest time was verified in the concentration of 20 mg L-1. Clove oil is effective and safe as an anesthetic for dourado juveniles in levels between 40 and 60 mg L-1.

  20. Morphological variation in populations of Tetragonopterus argenteus Cuvier, 1817 (Characiformes, Characidae from Madeira and Paraguay river basins Variação morfológica em populações de Tetragonopterus argenteus Cuvier, 1817 (Characiformes, Characidae das bacias dos rios Madeira e Paraguai

    Directory of Open Access Journals (Sweden)

    Willian Massaharu Ohara

    2007-10-01

    Full Text Available The saua Tetragonopterus argenteus is endemic to South America. It has a wide geographic distribution and occurs in different Brazilian basins, such as those of the Madeira and Paraguay rivers. In this work, it was noticed that populations from these basins have morphological variations between them, indicating a possible geographic isolation. Specimens were studied using twelve morphological characters that were submitted to the canonical variates and body proportion analysis. In the canonical variate analysis, the populations from the Madeira and Paraguay river basins were differentiated by caudal peduncle depth, eye diameter, pre-ventral distance, body height, snout length and head length. In the body proportion analysis, the population of Madeira river basin presented head length, orbital diameter, pre-dorsal distance, dorsal-fin length, pre-ventral distance, body height and caudal peduncle height, smaller than those of the population from Paraguay river basin. These results allowed the recognition of intra-specific variation amplitude, that could become an important instrument for management and conservation of this species. O sauá Tetragonopterus argenteus é endêmico da América do Sul, apresenta ampla distribuição geográfica e ocorre em várias bacias brasileiras, entre elas as dos rios Madeira e Paraguai. Neste trabalho foi observado que as populações dessas bacias apresentam variações morfológicas que, provavelmente, representam isolamento geográfico. Exemplares foram estudados através de 12 caracteres morfológicos e submetidos às análises de variáveis canônicas e de proporções corporais. Na análise das variáveis canônicas, as populações das bacias dos rios Madeira e Paraguai diferenciaram-se pelo diâmetro do olho, distância pré-ventral, altura do corpo, comprimento do focinho, altura do pedúnculo caudal e comprimento da cabeça. Na análise das proporções corporais, a população da bacia do rio Madeira apresentou comprimento da cabeça, diâmetro do olho, distância pré-dorsal, comprimento da base da nadadeira dorsal, distância pré ventral, altura do corpo e altura do pedúnculo caudal, menores que os das populações da bacia do rio Paraguai. Esses resultados possibilitam o reconhecimento da amplitude da variação intra-específica, que poderá ser um importante instrumento para o manejo e conservação dessa espécie de peixe.

  1. Digestibilidade aparente dos nutrientes e energia de ração suplementada com enzimas digestivas exógenas para juvenis de tambaqui (Colosssoma macropomum Cuvier, 1818 Apparent digestibility of nutrients and crude energy in diets with addition of exogenous digestive enzymes in tambaqui juveniles ( Colosssoma macropomum Cuvier, 1818

    Directory of Open Access Journals (Sweden)

    Jorge Antonio Moreira da Silva

    2007-01-01

    Full Text Available O experimento foi conduzido com o objetivo de avaliar o efeito da adição de um compelxo multienzimático exógeno composto de amilase, protease, lipase e celulase, em rações de juvenis de tambaqui, sobre os coeficientes de digestibilidade aparente (CDa da proteína bruta (PB, extrato etéreo (EE, carboidratos (ENN e energia bruta (EB. O delineamento experimental foi inteiramente casualizado com quatro tratamentos (quatro níveis de inclusão de enzimas, 0,0; 0,05; 0,10; e 0,15 %, três repetições (no tempo e 10 peixes por unidade experimental. Foram utilizados 40 juvenis de tambaqui, com peso médio de 155,0 ± 0,49 g, distribuídos em quatro tanques de alimentação de 500 l, recebendo refeições à vontade das 8 às 12h, a cada hora. Em seguida os animais foram transferidos para coletores de fezes (200 l, onde permaneceram até às 18h, sendo a coleta de dejetos realizada a cada hora. A determinação dos CDa foi realizada pelo método indireto, sendo utilizado como indicador externo 0,5% de óxido de cromo-III (Cr2O3 incorporado à ração. Os resultados demonstraram que a suplementação das dietas com enzimas exógenas para juvenis de tambaqui aumenta a digestibilidade aparente dos nutrientes e energia bruta, no nível de inclusão de 0,05% (PThe experiment evaluated the effect of dietary supplementation a multienzyme complex containing amylase, protease, lipase and cellulase for tambaqui juveniles on the apparent digestibility coefficients (ADCs of crude protein (CP, ether extract (EE, carbohydrates (CHO and crude energy (CE. A completely randomized experimental design was used with four treatments (level of enzymes 0.0; 0.05; 0.10; and 0.15 % and three replicates (over time, with ten fish per experimental unity. Forty fish weighting 155.0 ± 0.49g were distributed in four 500 l feeding tanks and were fed hourly, from 8 to 12 AM. After this period, fish were transferred for fecal collection units until 6 PM, where feces were collected hourly. ADCs were evaluated by an indirect method, with 0.5 % III-chromic oxide (Cr2O3 as innert marker. The results showed that supplementary exogenous enzymes on tambaqui diets increased the apparent digestibility of nutrients and crude energy at inclusion level of 0.05% (P<0.05%.

  2. Redescription of the Indo-Pacific scorpionfish Scorpaenodes guamensis (Quoy & Gaimard 1824) (Scorpaenidae), a senior synonym of seven nominal species.

    Science.gov (United States)

    Motomura, Hiroyuki; Causse, Romain; Struthers, Carl D

    2016-01-21

    The Indo-Pacific scorpionfish, Scorpaenodes guamensis (Quoy & Gaimard 1824), is redescribed on the basis of 137 specimens, including types, from a wide geographic range in the Indo-Pacific. Seven nominal species, Scorpaena rubropunctata Cuvier in Cuvier & Valenciennes 1829, Sebastes minutus Cuvier in Cuvier & Valenciennes 1829, Scorpaena chilioprista Rüppell 1838, Scorpaena polylepis Bleeker 1851, Centropogon echinatus Macleay 1881, Scorpaena erinacea Garman 1903, and Scorpaenopsis quiescens Seale 1906, are regarded here as junior synonyms of S. guamensis. The type status of these nominal species is discussed, and lectotypes of Scorpaena guamensis, Scorpaena rubropunctata, Sebastes minutus, and Scorpaena polylepis are herein designated. Validity of Scorpaenopsis scaber (Ramsay & Ogilby 1886) is also discussed.

  3. Geo scientific basis for making the safety case for a SF/HL W/IL W repository in Opalinus clay in ne Switzerland (project Entsorgungsnachweis) 1: overview and main conclusions

    International Nuclear Information System (INIS)

    Gautschi, A.; Lambert, A.; Zuidema, P.

    2004-01-01

    This paper provides an overview of the geo-scientific basis and the main conclusions concerning the safety case for Project Entsorgungsnachweis (Nagra, 2002a, see first paper). The key geo-scientific input for the safety case is summarised in the following three papers. The data and arguments are discussed in great detail in Nagra (2002b) and in numerous reference reports cited therein. (author)

  4. PERÍODOS DE ACTIVIDAD Y EFECTO DE LAS VARIABLES AMBIENTALES EN COCODRILOS (Crocodylus acutus Cuvier 1807): EVALUANDO LOS MÉTODOS DE DETERMINACIÓN DE LA FRACCIÓN VISIBLE.

    OpenAIRE

    Escobedo Galván, Armando H.; Escuela de Ciencias Ambientales, Universidad Latina de Costa Rica y Asociación Costarricense de Investigadores en Crocodilidos. (Costa Rica).

    2016-01-01

    Se realizaron un total de 8 muestreos durante los meses de Octubre y Noviembre de 2000, en La Estación Experimental La Rambla ubicada en Río Frío de Sarapiquí en la provincia de Heredia, Costa Rica. Se determinó que los cocodrilos presentan un pico de actividad durante la noche, y que el número de cocodrilos observados se ve afectado por condiciones climáticas previas y durante los muestreos. Se comparó los diferentes métodos estadísticos para calcular la fracción visible, determinando que no...

  5. NEMÁTODOS PARÁSITOS DE Lutjanus synagris (Linneaus, 1758 Y Lutjanus analis (Cuvier, 1828 (PERCIFORMES, LUTJANIDAE EN LAS ZONAS DE SANTA MARTA Y NEGUANJE, CARIBE COLOMBIANO

    Directory of Open Access Journals (Sweden)

    Cortés J.

    2009-09-01

    Full Text Available Se describen los nemátodos encontrados en el sistema digestivo de las especies de pargo Lutjanus synagris y Lutjanus analis. Esta investigación se orientó principalmente a la clasificación taxonómica de los parásitos y no a los efectos o patologías que estos puedan ocasionar en los peces. Se tuvo en cuenta que en Colombia los pargos constituyen uno de los recursos de mayor importancia para la comercialización; Lutjanus synagris y Lutjanus analis son especies demersales explotadas a lo largo de toda la región costera e insular del Caribe colombiano. Los tractos digestivos se colectaron de los pargos capturados artesanalmente (nasa, cordel por pescadores de las zonas de Santa Marta y Neguanje; se identificaron los siguientes géneros de nemátodos: Capillaria spp., Contracaecum spp., Cucullanus spp. y Raphidascaris spp.; el último género fue el más representativo.

  6. Estudos para Composição de uma Dieta Referência Semipurificada para Avaliação de Exigências Nutricionais em Juvenis de Pirapitinga, Piaractus brachypomus (Cuvier, 1818

    Directory of Open Access Journals (Sweden)

    Vásquez-Torres Wálter

    2002-01-01

    Full Text Available Foram realizados dois experimentos com o objetivo de definir uma dieta referência para estudos de exigências nutricionais em Piaractus brachypomus. No primeiro experimento, foram testadas quatro dietas com ingredientes semipurificados (H-440 com 47% PB, C-102 com 41% PB, NRC com 37% PB e IALL-1 com 32% de PB e uma dieta controle (32% de PB com ingredientes comuns. No segundo experimento, foi usada a dieta IALL-1, como base para a formulação de três dietas experimentais. A dieta 2 foi suplementada com vitamina C e uma pré-mistura de macrominerais, enquanto na dieta 3 o óleo vegetal foi substituído por óleo de peixe. O ganho de peso foi usado como critério básico para medir os efeitos das dietas, sendo também considerados consumo de alimento, taxa específica de crescimento (SGR, conversão alimentar aparente (FCR, eficiência de utilização da proteína (PER e retenção de proteína (%PPV e de energia (%RE. Entre as dietas semipurificadas, o melhor desempenho de crescimento e de utilização dos nutrientes foi observado para as dietas NRC e IALL-1, que não diferiram entre si. No segundo experimento, o grupo de peixes alimentados com a dieta 2 apresentou crescimento 42% maior que o observado com as dietas sem suplementação. As outras variáveis analisadas, FCR, SGR, PER e %PPV, também foram significativamente melhoradas. Os resultados em conjunto indicam que a dieta IALL-1 suplementada com macrominerais e vitamina C pode ser considerada adequada como dieta referência semipurificada para estudos de nutrição de Piaractus brachypomus.

  7. Feeding Relationship between Octopus vulgaris (Cuvier, 1797 Early Life-Cycle Stages and Their Prey in the Western Iberian Upwelling System: Correlation of Reciprocal Lipid and Fatty Acid Contents

    Directory of Open Access Journals (Sweden)

    Sílvia Lourenço

    2017-07-01

    Full Text Available Under the influence of the Western Iberian upwelling system, the Iberian Atlantic coast holds important hatcheries and recruitment areas for Octopus vulgaris. Recently identified as an octopus hatchery, the Ría de Vigo harbors an important mesozooplankton community that supports O. vulgaris paralarvae during the first days of their planktonic stage. This study represents a preliminary approach to determine the nutritional link between wild O. vulgaris hatchlings, paralarvae and their zooplankton prey in the Ría de Vigo, by analyzing their lipid class content and fatty acid profiles. The results show that octopus hatchlings are richer in structural lipids as phospholipids and cholesterol, while the zooplankton is richer in reserve lipids like triacylglycerol and waxes. Zooplankton samples are also particularly rich in C18:1n9 and 22:6n3 (DHA, that seem to be successfully incorporated by O. vulgaris paralarvae thus resulting in a distinct fatty acid profile to that of the hatchlings. On the other hand, content in C20:4n6 (ARA is maintained high through development, even though the zooplankton is apparently poorer in this essential fatty acid, confirming its importance for the development of O. vulgaris paralarvae. The content in monounsaturated fatty acids, particularly C18:1n7, and the DHA: EPA ratio are suggested as trophic markers of the diet of O. vulgaris paralarvae.

  8. The Sternoptychidae (Pisces, Stomiatoidei) of the Amsterdam Mid North Atlantic Plankton Expedition 1980, with a note on specimens intermediate between Argyropelecus aculeatus Valenciennes, 1849 and A. olfersi (Cuvier, 1829)

    NARCIS (Netherlands)

    Pafort-Van Iersel, Trudie

    1981-01-01

    The Sternoptychidae caught during a spring expedition in the Mid North Atlantic in 1980 are studied. Distribution patterns and data on abundance are recorded. It is proposed that Argyropelecus aculeatus and A. olfersi are two formae belonging to one species, the existing phenotypical differences

  9. Evaluación de los aportes de nitrógeno y fósforo al medio procedentes del engorde intensivo de pulpo común (Octopus vulgaris Cuvier)

    OpenAIRE

    Mazón Moya, María José

    2006-01-01

    Presentado como requisito parcial para la obtención del Tí­tulo de Máster Universitario Internacional en Acuicultura, otorgado por la Universidad de Las Palmas de Gran Canaria (ULPGC), el Instituto Canario de Ciencias Marinas (ICCM), y el Centro Internacional de Altos Estudios Agronómicos Mediterráneos de Zaragoza (CIHEAM)

  10. Le statut du genre Barbus Cuvier & Cloquet, 1816. Barbus Kahajani proposé comme nom de substitution pour Barbus tetrazona Bleeker, 1857, un homonyme secondaire de Barbus tetrazona Bleeker, 1955

    NARCIS (Netherlands)

    Hoedeman, J.J.

    1958-01-01

    Il existe encore une grande confusion au sujet du nom de genre correct s’appliquant à beaucoup de petits barbeaux de l’Inde orientale, lesquels, à juste titre, semble-t-il, ne devraient pas être maintenus dans le vieux genre Barbus. Pour ces espèces, et en particulier pour les espèces asiatiques, on

  11. Evaluación del tiempo de evacuación gástrica de la cachama blanca Piaractus brachypomus (Cuvier, 1818, utilizando diferentes frecuencias de alimentación y ayuno

    Directory of Open Access Journals (Sweden)

    José Ader Gómez-Peñaranda

    2013-12-01

    Full Text Available Este estudio estima el tiempo de vaciado del estómago de la cachama blanca (Piaractus brachypomus en el día de comienzo regular de alimentación posterior a un periodo de ayuno. Para el efecto, se recolectaron muestras de contenido estomacal en periodos de dos horas después del suministro de alimento (9:30 y 15:30 h hasta el primer indicio de vaciado. Se utilizaron cachamas con un peso de 360 ± 12 g dispuestas en cuatro tratamientos: (1 T1 = alimentación a saciedad durante 5 días y ayuno de 2 días, (2 T2 = alimentación a saciedad durante 6 días y ayuno de 1 día, (3 T3 = alimentación a saciedad durante 7 días, y (4 TC = alimentación siguiendo las tablas recomendadas por el fabricante del alimento. El análisis de datos se realizó mediante ANOVA de medidas repetidas, empleando como factores el tratamiento y el tiempo de vaciado, siendo cada repetición la unidad experimental. Las cachamas del tratamiento T1 presentaron mayor cantidad de alimento en el estómago en los muestreos posteriores al suministro de la primera y segunda ración. A diferencia del tratamiento T1, en los demás las cachamas vaciaron su contenido en el estómago en el periodo comprendido entre la primera y la segunda ración de alimentación y en el periodo posterior a la segunda ración. Por tanto, cuando el contenido estomacal fue mayor, debido a un mayor consumo de alimento en la ración, como en el caso del tratamiento (T1, el tiempo necesario para vaciar el estómago de las cachamas se incrementó.

  12. Parâmetros populacionais e simulação do rendimento por recruta de Salminus brasiliensis (Cuvier, 1816 do alto rio Paraná - DOI: 10.4025/actascibiolsci.v26i3.1593 Population parameters and simulation of the yield per recruit of Salminus brasiliensis (Cuvier, 1816 from the upper Paraná River - DOI: 10.4025/actascibiolsci.v26i3.1593

    Directory of Open Access Journals (Sweden)

    Angelo Antonio Agostinho

    2004-04-01

    Full Text Available O dourado Salminus brasiliensis é uma espécie explorada por todos os tipos de pesca na bacia do rio Paraná e sua captura tem sido diminuída nos últimos anos. Nesse contexto, o presente trabalho tem por objetivo simular o rendimento por recruta de S. brasiliensis partindo da necessidade de rever a regulamentação de pesca, na tentativa de conservar os estoques da espécie. Para realizar o trabalho, foram usados os dados de captura junto aos pescadores profissionais do município de Porto Rico, Estado do Paraná, no período de outubro de 1986 a setembro de 1988, amostrados com redes de espera, com linha e anzol, com espinhéis e com anzóis de galho. A simulação do rendimento por recruta foi realizada considerando diversos cenários de mortalidade por pesca e comprimentos mínimos de captura, a partir do modelo de rendimento de equilíbrio de Beverton e Holt, modificado por Jones. A simulação mostrou um incremento no rendimento por recruta para os comprimentos mínimos de 60 e de 65cm, sugerindo que mudanças na legislação em vigor devem ser consideradas. Além disso, sugerimos mudanças nos procedimentos operacionais das barragens, na época de reprodução da espécie, e proteção da pesca nos locais de desova e nos criadouros naturaisThe “dourado” Salminus brasiliensis (Characidae is caught in all types of fisheries conducted in the upper Paraná River. However, a decline has been observed in the quantity of S. brasiliensis harvested in recent years. In this paper, we deal with simulation of yield per recruit, in order to evaluate ongoing fishery regulation. We expect to generate information that guides the conservation of this species. Data from the artisanal fishery were gathered from October 1986 to September 1988, in the city of Porto Rico. In that region, to catch the “dourado”, fishers use gillnets, hook and line, long lines and branch hooks. Simulations of yield per recruit were performed under diverse scenarios of fishing mortality and minimum size of capture, using the equilibrium model of Beverton and Holt, modified by Jones. Simulations showed increase in the yield per recruit when minimum sizes of capture were 60cm and 65cm, suggesting that a review of ongoing fishery regulation is needed. In addition, adjustments in dam operations during the spawning season of the species, and protection and prohibition of the fishery in nursery and spawning areas are suggested

  13. Variations in stomach contents and biochemical composition of tissues in some marine fishes

    Digital Repository Service at National Institute of Oceanography (India)

    Jacob, P.G.; Rajagopal, M.D.

    Relationship between calorific values and protein, fat and carbohydrate of the stomach contents (food) and body tissues of marine fishes, Sardinella longiceps, Valenciennes, Rastrelliger kanagurta (Cuvier), Otolithus ruber (Schneider) and Lactarius...

  14. Volatile components from the anal glands of the yellow mongoose ...

    African Journals Online (AJOL)

    1988-12-01

    Dec 1, 1988 ... sampling, gas-liquid chromatography and mass spectrome- try. The odour volatiles were ... tube and over the secretion at a flow rate of 15 cm3 min-1 .... behaviour of the yellow mongoose, Cynictis penicillata. (G. Cuvier).

  15. First assessment of estuarine space use and home range of juvenile ...

    African Journals Online (AJOL)

    Lithognathus lithognathus Cuvier, 1829) in the permanently open Great Fish Estuary, South Africa, were assessed using acoustic telemetry. Seven individuals (154–184 mm fork length) tagged with acoustic transmitters spent the majority of their ...

  16. Mid-Frequency Sonar Interactions with Beaked Whales

    Science.gov (United States)

    2011-06-30

    et al. 2006), in the Bahamas and Madeira in 2000 (NOAA 2001, Cox et al. 2006), and in the Canary Islands in 2002 (Proceed. ECS 2004). Cuvier’s beaked...acoustic testing strand whales?" Nature 392. 29 (1998). L. Freitas, "The stranding of three Cuvier’s beaked whales Ziphius caviostris in Madeira ... Madeira , 1999-2002," Woods Hole Oceanographic Institution Technical Report. WHOI-2005- 09, 38 pp. (2005). Available online at http://www.whoi.edu

  17. Redescription of Oncophora melanocephala (Rudolphi, 1819 Baudin-Laurencin, 1971 (Nematoda, Camallanidae

    Directory of Open Access Journals (Sweden)

    R. Magalhães Pinto

    1988-06-01

    Full Text Available Oncophora melanocephala, a camallanid nematode from the small intestine of Priacanthus arenatus Cuvier, 1829 is redescribed from the Coast of Rio de Janeiro State, Brazil and this occurrence represents a new host record for the speciesOncophora melanocephala, um nematóide camalanídeo de instestino delgado de Priacanthus arenatus Cuvier, 1829, é redescrito da Costa do Estado do Rio de Janeiro, Brasil, e esta ocorrência representa um novo hospedeiro para a espécie.

  18. Epipona media cooper (Hymenoptera: Vespidae), a social wasp new to the Brazilian Atlantic Forest.

    Science.gov (United States)

    Menezes, Rodolpho S T; Carvalho Filho, Antonio F; Raw, Anthony; Costa, Marco A

    2010-01-01

    An occupied nest of Epipona media Cooper was discovered and collected in a cabruca (cocoa plantation with native tree cover). This is the first record of E. media from Bahia State. We described the nest structure and compared the adults with the closely related species Epipona tatua Cuvier.

  19. Interoceanic occurrence of species of Aristocleidus Mueller, 1936 (Monogenoidea: Dactylogyridae) parasitizing the gills of gerreid fishes in the Neotropics.

    Science.gov (United States)

    Mendoza Franco, Edgar F; Violante-González, Juan; Roche, Dominique G

    2009-09-01

    During investigations of fish parasites in the Neotropics (including the state of Veracruz and the Yucatán Peninsula in the Gulf of Mexico, the Chautengo Lagoon on the Pacific coast of the state of Guerrero in Mexico, and Lake Gatun in the Panama Canal), three monogenoidean (Dactylogyridae) species were found parasitizing the gills of gerreids (Gerreidae): Aristocleidus hastatus Mueller, 1936, was recovered from Eugerres plumieri (Cuvier) and Diapterus auratus Ranzani in Veracruz, from D. auratus and Diapterus rhombeus (Cuvier) in Yucatán, from Eugerres brasilianus (Cuvier) in Panama (all new hosts and geographical records), and from D. peruvianus (Cuvier) and Gerres cinereus (Walbaum) in Guerrero; Aristocleidus lamothei Kritsky and Mendoza-Franco, 2008, was recovered from E. plumieri in Veracruz and from D. rhombeus in Yucatan (new hosts and geographical records), and Aristocleidus sp. was recovered from G. cinereus in Guerrero. Results from this study suggest that species of Aristocleidus exhibit wide host specificity within gerreid fishes and that geminate species within this parasite genus may have originated with the formation of the Isthmus of Panama (3.1 to 3.5 ma). Evidence is also presented suggesting the potential role of the Panama Canal as a passageway allowing the interoceanic dispersal of Aristocleidus species across the isthmus.

  20. Growth lines within the beak microstructure of the Octopus octopus ...

    African Journals Online (AJOL)

    Octopus vulgaris Cuvier, 1797 is commercially the most important species in the central-eastern Atlantic cephalopod fishery. The estimation of growth parameters in wild octopus populations is essential to management of the fishery. As there are problems with methods based on length-frequency modal analyses for ...

  1. Recherches d’anatomie comparée sur le genre Stenops d’Illiger

    NARCIS (Netherlands)

    Schroeder van der Kolk, J.L.C.; Vrolik, W.

    1851-01-01

    Le genre Stenops D’Illiger contient des animaux fort curieux, qui, malgré les savantes recherches de plusieurs naturalistes, ne sont qu’imparfaitement connus. Aux observations disséminées dans les ouvrages anatomiques de Cuvier, de Meckel et de Tiedemann, chacun de nous a tâché, il y a quelque

  2. Socio-economic aspects of the tiger shark diving industry within the ...

    African Journals Online (AJOL)

    Understanding socio-economic aspects of the tiger shark Galeocerdo cuvier diving industry, including information on participant expectations, experiences and expenditure, is necessary for the effective management of the Aliwal Shoal Marine Protected Area on the east coast of South Africa. Between January and ...

  3. Seasonal variability of bull and tiger shark presence on the west ...

    African Journals Online (AJOL)

    A fisheries-independent survey using longlines and drumlines, and an acoustic telemetry study, revealed that bull sharks Carcharhinus leucas and tiger sharks Galeocerdo cuvier occur throughout the year off the west coast of Reunion Island. The research, which commenced in 2011, was conducted in response to an ...

  4. Passive acoustic monitoring of beaked whale densities in the Gulf of Mexico.

    Science.gov (United States)

    Hildebrand, John A; Baumann-Pickering, Simone; Frasier, Kaitlin E; Trickey, Jennifer S; Merkens, Karlina P; Wiggins, Sean M; McDonald, Mark A; Garrison, Lance P; Harris, Danielle; Marques, Tiago A; Thomas, Len

    2015-11-12

    Beaked whales are deep diving elusive animals, difficult to census with conventional visual surveys. Methods are presented for the density estimation of beaked whales, using passive acoustic monitoring data collected at sites in the Gulf of Mexico (GOM) from the period during and following the Deepwater Horizon oil spill (2010-2013). Beaked whale species detected include: Gervais' (Mesoplodon europaeus), Cuvier's (Ziphius cavirostris), Blainville's (Mesoplodon densirostris) and an unknown species of Mesoplodon sp. (designated as Beaked Whale Gulf - BWG). For Gervais' and Cuvier's beaked whales, we estimated weekly animal density using two methods, one based on the number of echolocation clicks, and another based on the detection of animal groups during 5 min time-bins. Density estimates derived from these two methods were in good general agreement. At two sites in the western GOM, Gervais' beaked whales were present throughout the monitoring period, but Cuvier's beaked whales were present only seasonally, with periods of low density during the summer and higher density in the winter. At an eastern GOM site, both Gervais' and Cuvier's beaked whales had a high density throughout the monitoring period.

  5. African Journal of Marine Science - Vol 20 (1998)

    African Journals Online (AJOL)

    Composition and spatial distribution of cephalopods in two North-western ... Growth lines within the beak microstructure of the Octopus octopus vulgaris cuvier, 1797 ... Summer distribution, abundance and population structure of illex argentines on the .... A preliminary investigation on how meteorological changes may affect ...

  6. Safety-relevant hydrogeological properties of the claystone barrier of a Swiss radioactive waste repository: An evaluation using multiple lines of evidence

    Science.gov (United States)

    Gautschi, Andreas

    2017-09-01

    In Switzerland, the Opalinus Clay - a Jurassic (Aalenian) claystone formation - has been proposed as the first-priority host rock for a deep geological repository for both low- and intermediate-level and high-level radioactive wastes. An extensive site and host rock investigation programme has been carried out during the past 30 years in Northern Switzerland, comprising extensive 2D and 3D seismic surveys, a series of deep boreholes within and around potential geological siting regions, experiments in the international Mont Terri Rock Laboratory, compilations of data from Opalinus Clay in railway and motorway tunnels and comparisons with similar rocks. The hydrogeological properties of the Opalinus Clay that are relevant from the viewpoint of long-term safety are described and illustrated. The main conclusions are supported by multiple lines of evidence, demonstrating consistency of conclusions based on hydraulic properties, porewater chemistry, distribution of natural tracers across the Opalinus Clay as well as small- and large-scale diffusion models and the derived conceptual understanding of solute transport.

  7. The connectivity of pore space in mudstones: insights from high-pressure Wood's metal injection, BIB-SEM imaging, and mercury intrusion porosimetry

    NARCIS (Netherlands)

    Klaver, J.; Hemes, S.; Houben, M.; Desbois, G.; Radi, Z.; Urai, J.L.

    2015-01-01

    Study of the pore space in mudstones by mercury intrusion porosimetry is a common but indirect technique and it is not clear which part of the pore space is actually filled with mercury. We studied samples from the Opalinus Clay, Boom Clay, Haynesville Shale, and Bossier Shale Formations using

  8. Interpretation of reflection seismics in the area North of Laegeren - Zurich Weinland

    International Nuclear Information System (INIS)

    Naef, H.; Birkhaeuser, P.; Roth, P.

    1995-05-01

    The investigations of potential siting areas for a repository for high-level radioactive waste which are concentrated in the crystalline basement of Northern Switzerland have been expanded since the late 1980s to include suitable sedimentary units. After extensive desk study evaluation, the approximately 100 m thick Opalinus Clay of the Tabular Jura east of the Aare river was chosen as the most promising sedimentary option. In this area not only the Opalinus Clay but also the over- and underlying units are clay-rich, in contrast to the tabular Jura west of the Aare river. In the area North of Laegeren - Zurich Weinland, where the Opalinus Clay is situated in the optimum depth range of 400 to 1000 m below surface, approximately 220 km of new high-resolution seismic profiles were recorded and interpreted together with existing seismic lines. Due to thorough field work and data processing, a very good quality of seismic lines was obtained. This allowed precise mapping of the marker horizons in general and the Opalinus Clay in detail. The goal of this study was to determine and delineate the most important tectonic units as well as to describe the potential host rocks in these units. By way of interactive interpretation of all available seismic lines, borehole data and surface data from the investigation area, depth maps of the most prominent marker horizons have been calculated and geological cross-sections constructed along the new seismic lines. The regional seismic character of the Middle Mesozoic units was modelled using borehole data from Weiach and Herdern. From this model the thickness of the Opalinus Clay along the new seismic lines was determined. The results indicate a relatively constant thickness of 95 to 120 m in the investigation area. (author) figs., tabs., refs

  9. Monitoring and modelling of thermo-hydro-mechanical processes - main results of a heater experiment at the Mont Terri underground rock laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Ingeborg, G.; Alheid, H.J. [BGR - Federal Institute for Geosciences and Natural Resources, Hannover (Germany); Jockwerz, N. [Gesellschaft fur Anlagen- und Reaktorsicherheit (GRS) - Final Repository Research Division, Braunschweig (Germany); Mayor, J.C. [ENRESA - Empresa Nacional des Residuos Radioactivos, Madrid (Spain); Garcia-Siner, J.L. [AITEMIN -Asociacion para la Investigacion y Desarrollo Industrial de los Recursos Naturales, Madrid, (Spain); Alonso, E. [CIMNE - Centre Internacional de Metodos Numerics en Ingenyeria, UPC, Barcelona (Spain); Weber, H.P. [NAGRA - National Cooperative for the Disposal of Radioactive Waste, Wettingen (Switzerland); Plotze, M. [ETHZ - Swiss Federal Institute of Technology Zurich, IGT, Zurich, (Switzerland); Klubertanz, G. [COLENCO Power Engineering Ltd., Baden (Switzerland)

    2005-07-01

    The long-term safety of permanent underground repositories relies on a combination of engineered and geological barriers, so that the interactions between the barriers in response to conditions expected in a high-level waste repository need to be identified and fully understood. Co-financed by the European Community, a heater experiment was realized on a pilot plant scale at the underground laboratory in Mont Terri, Switzerland. The experiment was accompanied by an extensive programme of continuous monitoring, experimental investigations on-site as well as in laboratories, and numerical modelling of the coupled thermo-hydro-mechanical processes. Heat-producing waste was simulated by a heater element of 10 cm diameter, held at a constant surface temperature of 100 C. The heater element (length 2 m) operated in a vertical borehole of 7 m depth at 4 to 6 m depth. It was embedded in a geotechnical barrier of pre-compacted bentonite blocks (outer diameter 30 cm) that were irrigated for 35 months before the heating phase (duration 18 months) began. The host rock is a highly consolidated stiff Jurassic clay stone (Opalinus Clay). After the heating phase, the vicinity of the heater element was explored by seismic, hydraulic, and geotechnical tests to investigate if the heating had induced changes in the Opalinus Clay. Additionally, rock mechanic specimens were tested in the laboratory. Finally, the experiment was dismantled to provide laboratory specimens of post - heating buffer and host rock material. The bentonite blocks were thoroughly wetted at the time of the dismantling. The volume increase amounted to 5 to 9% and was thus below the bentonite potential. Geo-electrical measurements showed no decrease of the water content in the vicinity of the heater during the heating phase. Decreasing energy input to the heater element over time suggests hence, that the bentonite dried leading to a decrease of its thermal conductivity. Gas release during the heating period occurred

  10. Respostas metabólicas do matrinxã submetido a banhos anestésicos de eugenol - DOI: 10.4025/actascibiolsci.v29i3.474 Metabolic responses of matrinxã to eugenol in anesthetic baths - DOI: 10.4025/actascibiolsci.v29i3.474

    Directory of Open Access Journals (Sweden)

    Luis Antônio Kioshi Aoki Inoue

    2007-12-01

    Full Text Available O matrinxã (Brycon amazonicus é uma espécie de interesse comercial. Porém, este peixe movimenta-se em excesso durante práticas de manejo, podendo sofrer ferimentos e perdas de escamas que, muitas vezes, resultam em taxas elevadas de mortalidade. O eugenol, principal componente do óleo de cravo, tem sido bastante utilizado como um anestésico alternativo para peixes por ser um produto natural e de baixo custo. Entretanto, estudos que tratam de respostas metabólicas, em peixes tropicais expostos a diferentes anestésicos, são ainda necessários. Dentro deste intuito, o presente trabalho avaliou respostas metabólicas do Brycon amazonicus ao eugenol, em simulações de banhos anestésicos. A demanda metabólica do matrinxã foi suprida principalmente pelo catabolismo de aminoácidos. Respostas típicas ao estresse foram detectadas por causa do manuseio imposto aos peixes para a realização dos banhos anestésicos. O eugenol não reduziu totalmente essas reações ao estresse. Por outro lado, esse anestésico não provocou estresse adicional em virtude de sua presença em exposições curtas de até 60 mg L-1 por 10 min. O eugenol proporciona segurança aos trabalhadores durante práticas de manejo, sem maiores prejuízos ao matrinxã.Matrinxã (Brycon amazonicus is a commercial fish that presents excessive movements during handling. This characteristic predisposes the animals to injuries and losses of scales that may result in high mortality rates. Eugenol, the main component of clove oil, has been reported as an alternative fish anesthetic because it is a natural product and cheap. However, studies remain necessary about the metabolic responses of tropical fishes to anesthetics. The present work evaluated metabolic responses of Brycon amazonicus to eugenol in simulated anesthetic baths. The fish metabolic demand was supplied mainly by amino acids catabolism. Typical metabolic stress responses to handling were detected but eugenol could

  11. Redescription of Prosthenhystera obesa (Diesing, 1850 (Callodistomidae, Digenea with New Host Records and Data on Morphological Variability

    Directory of Open Access Journals (Sweden)

    Anna Kohn

    1997-03-01

    Full Text Available Prosthenhystera obesa (Diesing,1850 Travassos, 1922 from the gall bladder of Astyanax bimaculatus, Caranx gibbosus, Galeocharax humeralis, Leporinus copelandii, Pimelodus fur, Pseudopimelodus roosevelti, Salminus brevidens, Salminus maxillosus and from the new hosts, Cynopotamus amazonum and Triurobrycon lundii is redescribed, demonstrating a large morphological variation, mainly in body and testes size and shape. New hosts harbouring immature specimens of P. obesa are presented: Brycon sp., Leporellus vittatus, Pachyurus squamipinnis, Pimelodus clarias, Pseudoplatystoma corruscans and Salminus hilarii. Scanning electron microscopy micrographies, original figures and measurements of adult and immature specimens from different Brazilian hosts and localities are presented

  12. A new metric for measuring condition in large predatory sharks.

    Science.gov (United States)

    Irschick, D J; Hammerschlag, N

    2014-09-01

    A simple metric (span condition analysis; SCA) is presented for quantifying the condition of sharks based on four measurements of body girth relative to body length. Data on 104 live sharks from four species that vary in body form, behaviour and habitat use (Carcharhinus leucas, Carcharhinus limbatus, Ginglymostoma cirratum and Galeocerdo cuvier) are given. Condition shows similar levels of variability among individuals within each species. Carcharhinus leucas showed a positive relationship between condition and body size, whereas the other three species showed no relationship. There was little evidence for strong differences in condition between males and females, although more male sharks are needed for some species (e.g. G. cuvier) to verify this finding. SCA is potentially viable for other large marine or terrestrial animals that are captured live and then released. © 2014 The Fisheries Society of the British Isles.

  13. A new species of Probursata Bravo-Hollis, 1984 (Mogenea: Heteraxinidae: Heteraxininae) parasite of Oligoplites spp. (Osteichthyes: Carangidae) from the coast of the state of Rio de Janeiro, Brazil

    OpenAIRE

    Ricardo M. Takemoto; J. F. R. Amato; José Luis Luque

    1993-01-01

    Probursata brasiliensis n. sp., a gill filament parasite of carangid fishes, O. palometa (Cuvier), Oligoplites saurus (Bloch & Schneider), and O. saliens (Bloch), from the Brazilian coast, is described and illustrated. The new species differs from Probursata veraecrucis Bravo-Hollis, 1984, the type and only species of this genus by the presence of spines in the auricular expansions of the genital atrium, by the trifurcate supplementary process of the clamp's midsclerite, and by having a l...

  14. Copépodes parasitos de Oligoplites spp. (Osteichthyes, Carangidae) da costa brasileira, com a redescrição de Tuxophorus caligodes Wilson, 1908 (Siphonostomatoida, Tuxophoridae)

    OpenAIRE

    Takemoto, Ricardo Massato; Universidade Estadual de Matingá; Luque, José Luis; UFRRJ; Luque, José Luis; UFRRJ

    2008-01-01

    Four species of caligid copepods, parasites of Oligoplites palometa (Cuvier, 1833), O. saurus (Bloch & Schneider, 1801) and O. saliens (Bloch, 1793) (Osteichthyes: Carangidae) from the Sepetiba Bay, coast of the state of Rio de Janeiro, Brazil, are presented. New geographical and host records for Caligus robustus Bassett-Smith, 1898, C. rufimaculatus Wilson, 1905, C. bonito Wilson, 1905 and Metacaligus rufus (Wilson, 1908) are given. Caligus oligoplitisi Carvalho, 1954 is considered a new jun...

  15. Monogeneans of leatherjackets, Oligoplites spp. (Osteichthyes: Carangidae), with the description of a new species of Metacamopia (Monogenea: Allodiscocotylidae) from the coast of the State of Rio de Janeiro, Brazil

    OpenAIRE

    Takemoto,Ricardo M; Amato,JFR; Luque,José Luis

    1996-01-01

    Metacamopia oligoplites n. sp., a gill filament parasite of carangid fishes of three species of Oligoplites Gill, O. palometa (Cuvier), O. saurus (Bloch & Schneider), and O. saliens (Bloch), from the coast of the State of Rio de Janeiro, Brazil, is described and illustrated. Metacamopia oligoplites n. sp. differs from M. indica by: the shape of the body; the pre-, para-, and post-germarial testes; vaginas lacking sclerotized structures; well-developed seminal receptacles; muscular sleeves...

  16. Morphology of the advanced-stage larva of Eustrongylides wenrichi Canavan 1929, occurring encapsulated in the tissues of Amphiuma in Louisiana.

    Science.gov (United States)

    Panesar, T S; Beaver, P C

    1979-02-01

    Larval nematodes identified as Eustrongylides wenrichi Canavan 1929, from cysts in the tissues of Amphiuma means tridactylum Cuvier in Louisana were redescribed. The extent of differentiation of the sex organs was found to be greater than that of 3rd-stage Dioctophyma renale, or of the infective stage of Trichinella spiralis, and comparable with the late 4th-stage larva of secernentean (phasmid) nematodes.

  17. バックランドの地質学と自然神学

    OpenAIRE

    松永, 俊男; Toshio, MATSUNAGA; 桃山学院大学文学部

    1994-01-01

    Scientific geology began in England early in the nineteenth century. Its leader was William Buckland. He imported the historical geology of Continental Europe into England. Historical geology was founded by Werner (a German) and Cuvier (a French), and developed largely by English geologists in the second quarter of the nineteenth century. English geology in the nineteenth century was based on natural theology. This was not the same as biblical geology, which interpreted literally the Mosaic s...

  18. Species Profiles. Life Histories and Environmental Requirements of Coastal Fishes and Invertebrates (South Florida). WHITE MULLET.

    Science.gov (United States)

    1985-05-01

    of the head Class ............ .Osteichthyes length. Order .... .......... Perciformes - Family .... ........... Mugilidae REASON FOR INCLUSION IN...SERIES Geographic range: Atlantic and East- The white mullet, the second most ern Pacific; in the Western Atlantic common species of the family Mugilidae ...del ciclo de Rep. 55(34):1-15. vida de MugiI curema Valenciennes in Cuviere- Valenciennes, 1836 Moore, R. H. 1973. Energetic re- ilisces: Mugilidae

  19. The dawn of chelonian research

    OpenAIRE

    MacCord, Kate; Caniglia, Guido; Moustakas-Verho, Jacqueline; Burke, Ann

    2015-01-01

    Many evo-devo studies of the turtle's shell draw hypotheses and support from historical sources. The groundbreaking works of Cuvier, Geoffroy St. Hilaire, Carus, Rathke, Owen, and others are being revived in modern research, and their centuries-old understanding of the turtle's shell reconsidered. In the works of these eminent biologists of the 19th century, comparative anatomy and embryology of turtle morphology set the stage for future studies in developmental biology, histology, and paleon...

  20. 5-year chemico-physical evolution of concrete-claystone interfaces, Mont Terri rock laboratory (Switzerland)

    Energy Technology Data Exchange (ETDEWEB)

    Mäder, U.; Jenni, A. [Institute of Geological Sciences, University of Berne, Berne (Switzerland); Lerouge, C. [French Geological Survey BRGM, Orléans (France); and others

    2017-04-15

    The Cement-Opalinus Clay Interaction (CI) Experiment at the Mont Terri rock laboratory is a long-term passive diffusion-reaction experiment between contrasting materials of relevance to engineered barrier systems/near-field for deep disposal of radioactive waste in claystone (Opalinus Clay). Reaction zones at interfaces of Opalinus Clay with two different types of concrete (OPC and 'low-pH'/ESDRED) were examined by sampling after 2.2 and 4.9 years. Analytical methods included element mapping (SEM, EPMA), select spot analysis (EDAX), 14C-MMA impregnation for radiography, and powder methods (IR, XRD, clay-exchanger characterisation) on carefully extracted miniature samples (mm). The presence of aggregate grains in concrete made the application of all methods difficult. Common features are a very limited extent of reaction within claystone, and a distinct and regularly zoned reaction zone within the cement matrix that is more extensive in the low-alkali cement (ESDRED). Both interfaces feature a de-calcification zone and overprinted a carbonate alteration zone thought to be mainly responsible for the observed porosity reduction. While OPC shows a distinct sulphate enrichment zone (indicative of ingress from Opalinus Clay), ESDRED displays a wide Mg-enriched zone, also with claystone pore-water as a source. A conclusion is that substitution of OPC by low-alkali cementitious products is not advantageous or necessary solely for the purpose of minimizing the extent of reaction between claystone and cementitious materials. Implications for reactive transport modelling are discussed. (authors)

  1. Isolation and characterization of Flavobacterium columnare (Bernardet et al. 2002 from four tropical fish species in Brazil

    Directory of Open Access Journals (Sweden)

    F. Pilarski

    Full Text Available Flavobacterium columnare is the causative agent of columnaris disease in freshwater fish, implicated in skin and gill disease, often causing high mortality. The aim of this study was the isolation and characterization of Flavobacterium columnare in tropical fish in Brazil. Piracanjuba (Brycon orbignyanus, pacu (Piaractus mesopotamicus, tambaqui (Colossoma macropomum and cascudo (Hypostomus plecostomus were examined for external lesions showing signs of colunmaris disease such as greyish white spots, especially on the head, dorsal part and caudal fin of the fish. The sampling comprised 50 samples representing four different fish species selected for study. Samples for culture were obtained by skin and kidney scrapes with a sterile cotton swabs of columnaris disease fish and streaked onto Carlson and Pacha (1968 artificial culture medium (broth and solid which were used for isolation. The strains in the liquid medium were Gram negative, long, filamentous, exhibited flexing movements (gliding motility, contained a large number of long slender bacteria and gathered into ‘columns'. Strains on the agar produced yellow-pale colonies, rather small, flat that had rhizoid edges. A total of four Flavobacterium columnare were isolated: 01 Brycon orbignyanus strain, 01 Piaractus mesopotamicus strain, 01 Colossoma macropomum strain, and 01 Hypostomus plecostomus strain. Biochemical characterization, with its absorption of Congo red dye, production of flexirubin-type pigments, H2S production and reduction of nitrates proved that the isolate could be classified as Flavobacterium columnare.

  2. Hydrogeologische Untersuchungen im oberflächennahen Opalinuston (Bohrloch Lausen, Schweiz)

    Science.gov (United States)

    Vogt, Tobias; Hekel, Uwe; Ebert, Andreas; Becker, Jens K.; Traber, Daniel; Giger, Silvio; Brod, Monika; Häring, Christian

    2017-09-01

    In Switzerland, the Opalinus Clay is being investigated in detail as a host rock for disposal of radioactive waste. To complement and improve existing data on near-surface decompaction effects, hydraulic-hydrochemical characterization of the Opalinus Clay from the weathering zone into the unweathered rock below was performed. For these investigations, one borehole of a borehole heat-exchanger field in Lausen (Canton Basel-Landschaft, Switzerland), which penetrates the near-surface Opalinus Clay, was completely cored. The hydraulic conductivity was determined by means of hydraulic tests in different depths and shows an decrease from 10-4 m/s at the very shallow weathered zone to 10-13 m/s starting at a depth of 28 m below the decompaction zone. In addition, different groundwater types could be identified. Moreover, the structural investigations indicate the end of the weathering zone at a depth of 18 m and that decompaction has no influence on hydraulic conductivity from 28 m onwards.

  3. Adrenocortical and adrenomedullary homologs in eight species of adult and developing teleosts: morphology, histology, and immunohistochemistry.

    Science.gov (United States)

    Grassi Milano, E; Basari, F; Chimenti, C

    1997-12-01

    Morphology, histology, and immunohistochemistry of the adrenocortical and adrenomedullary homologs (adrenal glands) of the following developing and adult teleosts were examined: Salmoniformes-Oncorhynchus mykiss (rainbow trout), Salmo trutta fario (brown trout), Coregonus lavaretus (white fish); Cyprinodontiformes-Gambusia affinis (mosquito fish). Perciformes-Dicentrarchus labrax (sea bass), Sparus aurata (sea bream), Diplodus sargus (white bream), Oblada melanura (saddled bream). The anatomical relationships of the gland with the renal system and venous vessels were also noted. In adults of all species steroidogenic and catecholaminergic chromaffin cells were found in the head kidney, which is pronephric in origin and subsequently transformed into a hematopoietic lymphatic organ. In Perciformes, chromaffin cells are distributed around the anterior and posterior cardinal veins and ducts of Cuvier; in Salmoniformes, around the posterior cardinal veins and in the hematopoietic tissue; and in G. affinis, around the ducts of Cuvier and posterior cardinal veins, while a few are visible also around the sinus venosus. In Perciformes and Salmoniformes, numerous chromaffin cells are also present in the posterior kidney, derived from the opisthonephros, in contact with the caudal vein. Steroidogenic cells are always confined to the head kidney. During development chromaffin and steroidogenic cells appear early after hatching in the pronephric kidney, at the level of the ducts of Cuvier and of the cephalic part of the posterior cardinal veins. Later, chromaffin cells in Perciformes reach the anterior cardinal veins, and subsequently, in both Perciformes and Salmoniformes, they reach the developing posterior kidney. Their localization along the posterior kidney is still in progress about 4 months after hatching and is completed about a year after hatching. These findings support the concept that the structure of the adrenal gland in teleosts is intermediate between that of the

  4. Experimental Studies of Engineered Barrier Systems Conducted at Los Alamos National Laboratory (FY16)

    Energy Technology Data Exchange (ETDEWEB)

    Caporuscio, Florie Andre [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Norskog, Katherine Elizabeth [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Maner, James [Univ. of Oklahoma, Norman, OK (United States). School of Geology and Geophysics; Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Palaich, Sarah [Univ. of California, Los Angeles, CA (United States). Dept. of Earth, Planetary, and Space Sciences; Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Cheshire, Michael C. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2016-08-04

    Over the past five years the Used Fuel Campaign has investigated Engineered Barrier Systems (EBS) at higher heat loads (up to 300°C) and pressure (150 bar). This past year experimental work was hindered due to a revamping of the hydrothermal lab. Regardless, two experiments were run this past year, EBS-18 and EBS-19. EBS-18 was run using Low Carbon Steel (LCS) and opalinus clay in addition to the bentonite and opalinus brine. Many of the past results were confirmed in EBS-18, such as the restriction of illite formation due to the bulk chemistry, pyrite degradation, and zeolite formation dependent on the bentonite and opalinus clay. The LCS show vast amounts of pit corrosion (over 100μm of corrosion in six weeks), leading a corrosion rate of 1083 μm/year. In addition, a mineral goethite, an iron-bearing hydroxide, formed in the pits of the LCS. Preliminary results from EBS-19 water chemistry are included but SEM imaging, micro probe and XRD are still needed for further results. Copper corrosion was investigated further and over 850 measurements were taken. It was concluded that pitting and pyrite degradation drastically increase the corrosion rate from 0.12 to 0.39 μm/day. However, the growth of a layer of the mineral chalcocite is thought to subdue the corrosion rate to 0.024 μm/day as observed in the EBS-13, a sixth month experiment. This document presents the findings of this past year.

  5. Two new species of Creptotrema (Digenea: Allocreadiidae from South America Dos especies nuevas de Creptotrema (Digenea: Allocreadiidae de América del Sur

    Directory of Open Access Journals (Sweden)

    Stephen S. Curran

    2008-08-01

    Full Text Available Two new digenean species belonging in Creptotrema Travassos, Artigas and Pereira, 1928 are described from specimens stored in the invertebrate collection at the Museum of Natural History, Geneva, Switzerland. Creptotrema lamothei n. sp. is described from Ageneiosus brevifilis Valenciennes in Cuvier and Valenciennes, 1840 (Siluriformes: Ageneiosidae, Auchenipterus nuchalis (Spix and Agassiz, 1829 (Siluriformes: Auchenipteridae, and Bryconops melanurus (Bloch, 1794 (Characiformes: Characidae in the Paraguay River, Paraguay. Creptotrema sucumbiosa n. sp. is described from Tetragonopterus argenteus Cuvier, 1816 (Characiformes: Characidae in Río Aquarico, Ecuador. Creptotrema lamothei differs from its congeners by having testes with irregular rather than entire outlines. Creptotrema sucumbiosa differs from its congeners by having a bilobed rather than entire ovary. Both C. lamothei and C. sucumbiosa differ from their other congeners by having relatively longer posttesticular spaces in their bodies, representing 25-30% and 24-28% of body length respectively, compared with approximately 6-19% in other species.Dos especies nuevas de digéneos pertenecientes a Creptotrema Travassos, Artigas y Pereira, 1928 fueron descritas de ejemplares depositados en la colección de invertebrados del Museo de Historia Natural de Ginebra, Suiza. Creptotrema lamothei n. sp. fue descrita en Ageneiosus brevifilis Valenciennes in Cuvier y Valenciennes, 1840 (Siluriformes: Ageneiosidae, Auchenipterus nuchalis (Spix y Agassiz, 1829 (Siluriformes: Auchenipteridae, y Bryconops melanurus (Bloch, 1794 (Characiformes: Characidae en el río Paraguay, Paraguay. Creptotrema sucumbiosa n. sp. fue descrita de Tetragonopterus argenteus, Cuvier 1816 (Characiformes: Characidae en el río Aquarico, Ecuador. Creptotrema lamothei difiere de sus congéneres por tener testículos con contornos irregulares en contraste con los que presentan contornos enteros. Creptotrema sucumbiosa difiere de

  6. Ten new records of marine invertebrates from the Azores

    Directory of Open Access Journals (Sweden)

    WIRTZ, P.

    2009-01-01

    Full Text Available The sea anemones Telmatactis cricoides (Duchassaign, 1850 and Actinia n. sp., themolluscs Tonna galea Linnaeus, 1758, Vitreolina philippi (de Rayneval & Ponzi, 1854,Melanella n. sp., Phidiana lynceus (de Rayneval & Ponzi, 1854 and Anomia patelliformis(Linnaeus, 1761, the nemertine Baseodiscus delineatus (DelleChiaje, 1825 and the echinoderms Leptosynapta inhaerens (O. F. Müller, 1776 and Stichopus regalis (Cuvier, 1817, are here recorded from the Azores for the first time. The presence of the two starfishspecies Chaetaster longipes (Retzius, 1805 and Luidia ciliaris (Philippi, 1837 in the Azores is confirmed and the spawning behaviour of the sea urchin Echinocyamus pusillus (O. F. Müller, 1776 is described.

  7. Ecologia parasitária de isópodos e biologia reprodutiva em tibiro, Oligoplites spp (Osteichthyes: carangidae) das águas costeiras de Natal, Rio Grande do Norte

    OpenAIRE

    Araújo, Gustavo Soares de

    2008-01-01

    As espécies Oligoplites palometa (Cuvier) e Oligoplites saurus (Bloch & Schneider) (Osteichthyes: Carangidae) são peixes costeiros pelágicos. O objetivo do presente trabalho foi estudar o parasitismo por isópodos e a biologia reprodutiva em tibiro, Oligoplites spp. Foram capturados cento e treze exemplares de Oligoplites spp durante o período de janeiro de 2005 a julho de 2007 nas águas costeiras de Natal, RN. Foram realizadas as medidas morfométricas e merísticas, a análise macroscópica pa...

  8. A new species of Probursata Bravo-Hollis, 1984 (Mogenea: Heteraxinidae: Heteraxininae parasite of Oligoplites spp. (Osteichthyes: Carangidae from the coast of the state of Rio de Janeiro, Brazil

    Directory of Open Access Journals (Sweden)

    Ricardo M. Takemoto

    1993-06-01

    Full Text Available Probursata brasiliensis n. sp., a gill filament parasite of carangid fishes, O. palometa (Cuvier, Oligoplites saurus (Bloch & Schneider, and O. saliens (Bloch, from the Brazilian coast, is described and illustrated. The new species differs from Probursata veraecrucis Bravo-Hollis, 1984, the type and only species of this genus by the presence of spines in the auricular expansions of the genital atrium, by the trifurcate supplementary process of the clamp's midsclerite, and by having a larger number of tests and clamps. This is the first record of the genus Probursata Bravo-Hollis, 1984, in the South Atlantic Ocean.

  9. A review of the genus Pempheris (Perciformes, Pempheridae) of the Red Sea, with description of a new species.

    Science.gov (United States)

    Koeda, Keita; Yoshino, Tetsuo; Imai, Hideyuki; Tachihara, Katsunori

    2014-04-30

    Four species of the fish genus Pempheris are recognized for the Red Sea: P. adusta Bleeker, 1877; P. mangula Cuvier, 1829; P. nesogallica Cuvier in Cuvier & Valenciennes, 1831; and a new species P. tominagai. All are wide-ranging in the western Indian Ocean, and P. mangula has migrated via the Suez Canal to the eastern Mediterranean Sea. Morphological and genetic analysis of 15 species in this genus show that P. adusta, a widely distributed species, that can't be divided into different species, because of the continuity of morphologies and distribution, and lack of variance in genetics between Indian Ocean, Red Sea, and Pacific Ocean populations. This confirms that the two subspecies described by Randall et al. (2013) are both synonyms of P. adusta. Pempheris adusta is distinguished from other species by a blackish spot on pectoral fin base, pored lateral-line scales 56-64, scale rows above lateral line 4 1/2-6 1/2, distinct blackish band on outer edge of anal fin, and blackish band on posterior edge of caudal fin. Pempheris mangula was named by Cuvier (1829) in a footnote making reference to a drawing and short description in Russell (1803) of a Pempheris from southeast India, giving only the native name ''Mangula-Kutti'', and listing no specimen. The wide distribution of this species, from the Indian Ocean to the Red Sea is also demonstrated by morphological and genetic analysis. Thus, the specimen collected from southern India is herein designated as the neotype. This species is distinguished from other species by its huge eye, deep body, blackish tip of the dorsal fin, pored lateral-line scales 49-60, and scale rows above lateral line 4 1/2-5 1/2. The extant syntype of Kossmann & Räuber's P. rhomboidea is designated as the lectotype of the species; however, P. rhomboidea is a synonym of P. mangula. In addition, Kossmann & Räuber's Pempheris erythraea and P. russellii Day, 1888 are also synonyms of P. mangula. Of two existing syntypes of P. nesogallica from

  10. Las faunas pleistocenas de Fuensanta del Júcar y El Provencio y su significado en la evolución del Cuaternario de la Llanura manchega.

    OpenAIRE

    Mazo Pérez, Ana Victoria; Pérez-González, Alfredo; Aguirre, Emiliano

    1990-01-01

    Las terrazas fluviales de +60 m de Fuensanta del Júcar (Sistema aluvial del río Júcar) y de +15-16 m de El Provencio, perteneciente al Sistema fluvial del Guadiana, han proporcionado restos de vertebrados del Pleistoceno. En la primera localidad, que se encuentra en Albacete, se han identificado: Mammuthus meridionalis NESTI, forma progresiva, Hippopotamus major CUVIER y Cervidae ind. En El Provencio (Cuenca): Mammuthus meridionalis NESTI y Bovidae ind. (Bos o Bison). El grado de evolución de...

  11. Continuous osteological characters in the reconstruction of phylogenetic relationships of the six Euro-Mediterranean mullet species (Mugilidae).

    Science.gov (United States)

    Antović, Ivanka

    2013-09-01

    Sixty-three continuous osteological characters (18 skull continuous characters and the total length of neurocranium, 45 continuous characters of 15 elements of the viscerodermal skeleton) were analyzed and included in the reconstruction of phylogenetic relationships of the six Euro-Mediterranean mullet species from the South Adriatic Sea: Mugil cephalus Linnaeus, 1758; Liza saliens Risso, 1810; Liza aurata Risso, 1810; Liza ramada Risso, 1826; Chelon labrosus Risso, 1826 and Oedalechilus labeo Cuvier, 1829. The study reveals that Sphyraenidae was separated clearly from Mugilidae, C. labrosus and three Liza species form a common cluster (L. ramada and L. saliens being the closest), while O. labeo and M. cephalus cluster together.

  12. Mont Terri rock laboratory, 20 years of research: introduction, site characteristics and overview of experiments

    International Nuclear Information System (INIS)

    Bossart, P.; Bernier, F.; Birkholzer, J.

    2017-01-01

    Geologic repositories for radioactive waste are designed as multi-barrier disposal systems that perform a number of functions including the long-term isolation and containment of waste from the human environment, and the attenuation of radionuclides released to the subsurface. The rock laboratory at Mont Terri (canton Jura, Switzerland) in the Opalinus Clay plays an important role in the development of such repositories. The experimental results gained in the last 20 years are used to study the possible evolution of a repository and investigate processes closely related to the safety functions of a repository hosted in a clay rock. At the same time, these experiments have increased our general knowledge of the complex behaviour of argillaceous formations in response to coupled hydrological, mechanical, thermal, chemical, and biological processes. After presenting the geological setting in and around the Mont Terri rock laboratory and an overview of the mineralogy and key properties of the Opalinus Clay, we give a brief overview of the key experiments that are described in more detail in the following research papers to this Special Issue of the Swiss Journal of Geosciences. These experiments aim to characterise the Opalinus Clay and estimate safety-relevant parameters, test procedures, and technologies for repository construction and waste emplacement. Other aspects covered are: bentonite buffer emplacement, high-pH concrete-clay interaction experiments, anaerobic steel corrosion with hydrogen formation, depletion of hydrogen by microbial activity, and finally, release of radionuclides into the bentonite buffer and the Opalinus Clay barrier. In the case of a spent fuel/high-level waste repository, the time considered in performance assessment for repository evolution is generally 1 million years, starting with a transient phase over the first 10,000 years and followed by an equilibrium phase. Experiments dealing with initial conditions, construction, and waste

  13. Nagra technical report 14-02, geological basics - Dossier IV - Information on geo-mechanics; SGT Etappe 2: Vorschlag weiter zu untersuchender geologischer Standortgebiete mit zugehörigen Standortarealen für die Oberflächenanlage -- Geologische Grundlagen -- Dossier IV -- Geomechanische Unterlagen

    Energy Technology Data Exchange (ETDEWEB)

    Marschall, P.; Giger, S.

    2014-12-15

    This dossier is the fourth of a series of eight reports concerning the safety and technical aspects of locations for the disposal of radioactive wastes in Switzerland. This Dossier IV considers the documentation on geo-mechanical aspects that is available. Rock-stress conditions are looked at as are the methods and instrumentation used to establish them. The results of local analyses are presented and discussed, as are the magnitudes and long-term stability of such stress conditions. The geo-mechanical properties of Opalinus Clay as a host rock for a repository are discussed. Mountain-building models and coupled hydro-mechanical processes are also discussed.

  14. Mont Terri rock laboratory, 20 years of research: introduction, site characteristics and overview of experiments

    Energy Technology Data Exchange (ETDEWEB)

    Bossart, P. [Swisstopo, Federal Office of Topography, Wabern (Switzerland); Bernier, F. [Federal Agency for Nuclear Control FANC, Brussels (Belgium); Birkholzer, J. [Lawrence Berkeley National Laboratory, Berkeley (United States); and others

    2017-04-15

    Geologic repositories for radioactive waste are designed as multi-barrier disposal systems that perform a number of functions including the long-term isolation and containment of waste from the human environment, and the attenuation of radionuclides released to the subsurface. The rock laboratory at Mont Terri (canton Jura, Switzerland) in the Opalinus Clay plays an important role in the development of such repositories. The experimental results gained in the last 20 years are used to study the possible evolution of a repository and investigate processes closely related to the safety functions of a repository hosted in a clay rock. At the same time, these experiments have increased our general knowledge of the complex behaviour of argillaceous formations in response to coupled hydrological, mechanical, thermal, chemical, and biological processes. After presenting the geological setting in and around the Mont Terri rock laboratory and an overview of the mineralogy and key properties of the Opalinus Clay, we give a brief overview of the key experiments that are described in more detail in the following research papers to this Special Issue of the Swiss Journal of Geosciences. These experiments aim to characterise the Opalinus Clay and estimate safety-relevant parameters, test procedures, and technologies for repository construction and waste emplacement. Other aspects covered are: bentonite buffer emplacement, high-pH concrete-clay interaction experiments, anaerobic steel corrosion with hydrogen formation, depletion of hydrogen by microbial activity, and finally, release of radionuclides into the bentonite buffer and the Opalinus Clay barrier. In the case of a spent fuel/high-level waste repository, the time considered in performance assessment for repository evolution is generally 1 million years, starting with a transient phase over the first 10,000 years and followed by an equilibrium phase. Experiments dealing with initial conditions, construction, and waste

  15. Predicting the uptake of Cs, Co, Ni, Eu, Th and U on argillaceous rocks using sorption models for illite

    International Nuclear Information System (INIS)

    Marques Fernandes, Maria; Vér, Nóra; Baeyens, Bart

    2015-01-01

    Highlights: • Contaminant retention in argillaceous rocks controlled by sorption on clay minerals. • Cs, Ni, Co, Eu, Th and UO 2 sorption isotherm measurements on Boda and Opalinus Clay. • Boda and Opalinus Clay exhibit different mineralogies and porewater compositions. • Blind predictions using quasi-mechanistic sorption models developed for illite. • Good agreement between measurements and blind predictions. - Abstract: Reliable predictions of radiocontaminant migration are a requirement for the establishment of radioactive waste repositories. Parametrization of the necessary sorption models seems to be, however, extremely challenging given the multi-mineralic composition of the lithosphere. In this study it is shown for two argillaceous rocks – Boda and Opalinus Clay relevant for the Hungarian and Swiss repository concepts, respectively – that this task can be substantially simplified by taking into account only the most sorptive mineral fraction, namely the 2:1 clay minerals illite and illite/smectite mixed layers. Two different models were required to blind predict the sorption isotherms of Cs, Co, Ni, Eu, Th and UO 2 measured on the two clay rock samples in a synthetic porewater. Cs sorption was modelled with the generalised Cs (GCs) sorption model and the sorption of the other cations with the 2site protolysis non electrostatic surface complexation and cation exchange (2SPNE SC/CE) model. The 2SPNE SC/CE model for illite was extended with surface complexation reactions on weak sites for Co, Ni, Eu, UO 2 and on strong sites for Eu-carbonato complexes. Complementary to the sorption measurements and modelling, extended X-ray absorption fine structure (EXAFS) spectroscopy was used to probe the retention mechanism of Ni on illite, Boda and Opalinus Clay at higher loadings. The reliable blind predictions of the selected metal cations, which are representative for monovalent alkaline metals, divalent transition metals, lanthanides, and trivalent

  16. Exploring diffusion and sorption processes at the Mont Terri rock laboratory (Switzerland): lessons learned from 20 years of field research

    Energy Technology Data Exchange (ETDEWEB)

    Leupin, O.X. [National Cooperative for the Disposal of Radioactive Waste (NAGRA), Wettingen (Switzerland); Van Loon, L.R. [Paul Scherrer Institute PSI, Villigen (Switzerland); Gimmi, T. [Institute of Geological Sciences, University of Berne, Berne (Switzerland); Gimmi, T. [Institute of Environmental Assessment and Water Research IDAEA-CSIC, Barcelona (Spain); and others

    2017-04-15

    Transport and retardation parameters of radionuclides, which are needed to perform a safety analysis for a deep geological repository for radioactive waste in a compacted claystone such as Opalinus Clay, must be based on a detailed understanding of the mobility of nuclides at different spatial scales (laboratory, field, geological unit). Thanks to steadily improving experimental designs, similar tracer compositions in different experiments and complementary small laboratory-scale diffusion tests, a unique and large database could be compiled. This paper presents the main findings of 20 years of diffusion and retention experiments at the Mont Terri rock laboratory and their impact on safety analysis. (authors)

  17. Results of laboratory and in-situ measurements for the description of coupled thermo-hydro-mechanical processes in clays

    Energy Technology Data Exchange (ETDEWEB)

    Goebel, Ingeborg; Alheid, Hans-Joachim [BGR Hannover, Stilleweg 2, D-30655 Hannover (Germany); Jockwer, Norbert [Gesellschaft fuer Anlagen- und Reaktorsicherheit (GRS) mbH, Theodor-Heuss-Str. 4, 38122 Braunschweig (Germany); Mayor, Juan Carlos [ENRESA, Emilio Vargas 7, E-Madrid (Spain); Garcia-Sineriz, Jose Luis [AITEMIN, c/ Alenza, 1 - 28003 Madrid (Spain); Alonso, Eduardo [International Center for Numerical Methods in Engineering, CIMNE, Edificio C-1, Campus Norte UPC, C/Gran Capitan, s/n, 08034 Barcelona (Spain); Weber, Hans Peter [NAGRA, Hardstrasse 73, CH-5430 Wettingen (Switzerland); Ploetze, Michael [ETHZ, Eidgenoessische Technische Hochschule Zuerich, ETH Zentrum, HG Raemistrasse 101, CH-8092 Zuerich (Switzerland); Klubertanz, Georg [COLENCO Power Engineering Ltd, CPE, Taefern Str. 26, 5405 Baden-Daettwil (Switzerland); Ammon, Christian [Rothpletz, Lienhard, Cie AG, Schifflaendestrasse 35, 5001 Aarau (Switzerland)

    2004-07-01

    The Heater Experiment at the Mont Terri Underground Laboratory aims at producing a validated model of thermo-hydro-mechanically (THM) coupled processes. The experiment consists of an engineered barrier system where in a vertical borehole, a heater is embedded in bentonite blocks, surrounded by the host rock, Opalinus Clay. The experimental programme comprises permanent monitoring before, during, and after the heating phase, complemented by geotechnical, hydraulic, and seismic in-situ measurements as well as laboratory analyses of mineralogical and rock mechanics properties. After the heating, the experiment was dismantled for further investigations. Major results of the experimental findings are outlined. (authors)

  18. Biogeochemical processes in a clay formation in situ experiment: Part B - Results from overcoring and evidence of strong buffering by the rock formation

    Energy Technology Data Exchange (ETDEWEB)

    Koroleva, M. [Institute of Geological Sciences, University of Bern, Baltzerstrasse 3, CH-3012 Bern (Switzerland); Lerouge, C. [BRGM, French Geological Survey, 3 Avenue Claude Guillemin, B.P. 36009, 45060 Orleans Cedex 2 (France); Maeder, U., E-mail: urs.maeder@geo.unibe.ch [Institute of Geological Sciences, University of Bern, Baltzerstrasse 3, CH-3012 Bern (Switzerland); Claret, F.; Gaucher, E. [BRGM, French Geological Survey, 3 Avenue Claude Guillemin, B.P. 36009, 45060 Orleans Cedex 2 (France)

    2011-06-15

    Highlights: > A 5-year in situ porewater chemistry experiment in Opalinus Clay was overcored and examined. > A microbial perturbation induced sulfate reduction, pH decrease and alkalinity / P{sub CO2} increase. > Changes to mineralogy, isotopic composition and bulk properties could not be detected. > Precipitation of Fe-sulfides and carbonate occurred at the interface of the test interval. > The chemical perturbation was effectively buffered by the claystone's large capacity. - Abstract: An in situ Porewater Chemistry (PC) experiment in the Opalinus Clay formation was carried out at the Mont Terri underground rock laboratory (Jura Mountains, Switzerland) for a period of 5 a. A traced water with a composition close to that expected in the formation was continuously circulated and monitored in a packed-off borehole to achieve diffusive equilibration. An unwanted microbial perturbation changed the water composition, characterized by reduction of SO{sub 4} combined with increasing sulfide, increasing alkalinity, decreasing pH and increasing P(CO{sub 2}). In contrast, the main cations (Na, Ca, Mg) remained remarkably constant during the experiment, thus indicating the strong buffering of the formation via cation and proton exchange as well as carbonate dissolution/precipitation reactions. After 5 a, the 4.5 m long vertical test interval was overcored and Opalinus Clay samples were analyzed along ca. 15 cm long radial profiles. The analytical investigations included mineralogy (XRD, SEM-EDX), bulk parameters (water content, density, C, S), cation exchange capacity and occupancy, aqueous leachates for Cl{sup -}, Br{sup -}, SO{sub 4}{sup 2-} and water and carbonate stable isotopes. Emphasis was put on best sample preparation and conservation techniques. Results show that the distribution of non-reactive tracers (Br{sup -} and {sup 2}H) follows the expected out/in-diffusion profiles compatible with the time-dependent boundary conditions in the test interval of the

  19. Could beaked whales get the bends? Effect of diving behaviour and physiology on modelled gas exchange for three species: Ziphius cavirostris, Mesoplodon densirostris and Hyperoodon ampullatus.

    Science.gov (United States)

    Hooker, Sascha K; Baird, Robin W; Fahlman, Andreas

    2009-07-31

    A mathematical model, based on current knowledge of gas exchange and physiology of marine mammals, was used to predict blood and tissue tension N2 (P(N2)) using field data from three beaked whale species: northern bottlenose whales, Cuvier's beaked whales, and Blainville's beaked whales. The objective was to determine if physiology (body mass, diving lung volume, dive response) or dive behaviour (dive depth and duration, changes in ascent rate, diel behaviour) would lead to differences in P(N2) levels and thereby decompression sickness (DCS) risk between species. Diving lung volume and extent of the dive response had a large effect on end-dive P(N2). The dive profile had a larger influence on end-dive P(N2) than body mass differences between species. Despite diel changes in dive behaviour, P(N2) levels showed no consistent trend. Model output suggested that all three species live with tissue P(N2) levels that would cause a significant proportion of DCS cases in terrestrial mammals. Cuvier's beaked whale diving behaviour appears to put them at higher risk than the other species, which may explain their prevalence in strandings after the use of mid-frequency sonar.

  20. New species of Diplectanum (Monogenoidea:Diplectanidae), and proposal of a new genus of the Dactylogyridae from the gills of gerreid fishes (Teleostei) from Mexico and Panama.

    Science.gov (United States)

    Franco, Edgar F Mendoza; Roche, Dominique G; Torchin, Mark E

    2008-09-01

    While investigating the parasites of several marine fishes from the Western Atlantic, the Southern Gulf of Mexico and Central America (Panama), the following monogenoidean species from the gills of gerreid fishes (Gerreidae) were found: Diplec-tanum gatunense sp. n. (Diplectanidae) and Octouncuhaptor eugerrei gen. et sp. n. (Dactylogyridae) in Eugerres brasilianus (Cuvier) from Gatun Lake in the Panama Canal Watershed, and Diplectanum mexicanum sp. n. in Diapterus rhombeus (Cuvier) from the coast of Campeche State, Mexico. New diplectanid species are distinguished from other species of the genus by the general morphology of the copulatory complex and by the shape of the anchors and bars on the haptor. Octouncuhaptor gen. n. is proposed for its new species having slightly overlapping gonads (testis posterodorsal to the ovary), a dextrolateral vaginal aperture, a copulatory complex consisting of a coiled male copulatory organ with counterclockwise rings with the base articulated to the accessory piece, 8 pairs of hooks and the absence of anchors and bars on haptor. Our analysis of morphological features of Diplectanum species on gerreids evidences that these parasites more closely resemble each other than the known species from sciaenids suggesting that split between gerreids and sciaenids resulted in parasite speciation.

  1. Hirudinella ventricosa (Pallas, 1774) Baird, 1853 represents a species complex based on ribosomal DNA.

    Science.gov (United States)

    Calhoun, Dana M; Curran, Stephen S; Pulis, Eric E; Provaznik, Jennifer M; Franks, James S

    2013-10-01

    Digeneans in the genus Hirudinella de Blainville, 1828 (Hirudinellidae) from three species of pelagic fishes, Acanthocybium solandri (Cuvier), Makaira nigricans Lacépède and Thunnus albacares (Bonnaterre), and one benthic fish, Mulloidichthys martinicus (Cuvier), from the Gulf of Mexico are investigated using comparison of ribosomal DNA. Four species are identified based on molecular differences: Hirudinella ventricosa (Pallas, 1774) Baird, 1853 from A. solandri, Hirudinella ahi Yamaguti, 1970 from T. albacares, and two unidentified but distinct species of Hirudinella, herein referred to as Hirudinella sp. A (from both M. nigricans and M. martinicus) and Hirudinella sp. B from M. nigricans. Additionally, H. ahi, based tentatively on morphological identification, is reported from Thunnus thynnus (Linnaeus). This represents the first record of a hirudinellid from M. martinicus and the first record of H. ahi from T. thynnus. A phylogeny of some Hemiurata Skrjabin & Guschanskaja, 1954 using partial fragments of the 28S rDNA sequences is consistent with earlier phylogenies and the position of the Hirudinellidae Dollfus, 1932 is well-supported as a derived group most closely related to the Syncoeliidae Looss, 1899.

  2. Relative abundance and size of coastal sharks derived from commercial shark longline catch and effort data.

    Science.gov (United States)

    Carlson, J K; Hale, L F; Morgan, A; Burgess, G

    2012-04-01

    In the north-west Atlantic Ocean, stock assessments conducted for some commercially harvested coastal sharks indicate declines from 64 to 80% with respect to virgin population levels. While the status of commercially important species is available, abundance trend information for other coastal shark species in the north-west Atlantic Ocean are unavailable. Using a generalized linear modelling (GLM) approach, a relative abundance index was derived from 1994 to 2009 using observer data collected in a commercial bottom longline fishery. Trends in abundance and average size were estimated for bull shark Carcharhinus leucas, spinner shark Carcharhinus brevipinna, tiger shark Galeocerdo cuvier and lemon shark Negaprion brevirostris. Increases in relative abundance for all shark species ranged from 14% for C. brevipinna, 12% for C. leucas, 6% for N. brevirostris and 3% for G. cuvier. There was no significant change in the size at capture over the time period considered for all species. While the status of shark populations should not be based exclusively on abundance trend information, but ultimately on stock assessment models, results from this study provide some cause for optimism on the status of these coastal shark species. Published 2012. This article is a U.S. Government work and is in the public domain in the USA.

  3. The diet of the South American sea lion (Otaria flavescens at Río Negro, Patagonia, Argentina, during the winter-spring period

    Directory of Open Access Journals (Sweden)

    Raimundo L. Bustos

    2012-12-01

    Full Text Available The South American sea lion, Otaria flavescens (Shaw, 1800 population is steadily expanding along the Patagonian coast of Argentina in the last decades. However, little is known about the feeding ecology of the species in the area. The aim of this study was to analyze the food habits of O. flavescens from 91 scats collected at Río Negro province, during the winter and spring of 2005. Fish occurred in 96% of scats containing prey remains, followed by cephalopods (26%. Raneya brasiliensis (Kaup, 1856 was the most frequent and abundant species occurring in 58.6% of samples and constituting almost 50% of fish predated. Second in importance were Porichthys porosissimus (Cuvier, 1829 and Cynoscion guatucupa (Cuvier, 1830 in terms of occurrence (%FO 20.7 and numbers (29.6% respectively. The squid Loligo gahi (d'Orbigny, 1835 was the most frequent cephalopod prey (42.1%, whereas Octopus tehuelchus (d'Orbigny, 1834 was the most abundant (77%. The higher amount and diversity of prey found in the spring in comparison with the winter season might be related to a higher feeding activity of seals or to a seasonal increase in food availability in the area.

  4. Nilonema gymnarchi Khalil, 1960 and N. senticosum (Baylis, 1922) (Nematoda: Dracunculoidea): Gondwana relicts?

    Science.gov (United States)

    Santos, Cláudia Portes; Gibson, David I

    2007-07-01

    Data-base searches of records of the helminth parasites of South American and African freshwater fishes revealed only two pairs of species from genera endemic to the two regions. One pair, species of the primitive amphilinid cestode genus Nesolecithus Dönges & Harder, 1966, has already been designated as likely Gondwana relicts. The second pair are the philometrid nematodes Nilonema gymnarchi Khalil, 1960 from Gymnarchus niloticus Cuvier (Gymnarchidae) in Africa and N. senticosum (Baylis, 1922) from the South American fish Arapaima gigas (Cuvier) (Arapaimidae). Both species are partly redescribed on the basis of light and scanning electron microscopical observations of the type-specimens, and their relationships are discussed. In view of the fact that both hosts are basal teleosts of the order Osteoglossiformes and they are the same two fish which harbour the amphilinid cestodes already indicated as Gondwana relics, the nematode pair is also deemed to be relictual. However, these species are suggested as being of limited potential value for calibrating a molecular clock.

  5. Trace elements in tissues of cetacean species rarely stranded along the Israeli Mediterranean coast.

    Science.gov (United States)

    Shoham-Frider, Efrat; Kerem, Dan; Roditi-Elasar, Mia; Goffman, Oz; Morick, Danny; Yoffe, Olga; Kress, Nurit

    2014-06-15

    In this paper we present the concentrations of Hg, Cd, Se, Pb, Cu, Mn, Zn and Fe in organs of 6 non-common specimens of cetaceans that were stranded along the Israeli Mediterranean coast (IMC), during 2002-2010: two fin whales, one minke whale, one Cuvier's beaked whale, one rough-toothed dolphin, and one Risso's dolphin. Most of the specimens were calves stranded by accident. Concentrations of Hg and Cd were low in tissues of the baleen whales and higher in the toothed whales, with maximum concentrations of 1067 mg kg(-1) Hg in the liver of the Risso's dolphin and 29 mg kg(-1) Cd in the kidney of the Cuvier's beaked whale. As far as we are aware, this is the first report of trace elements in baleen whales in the Eastern Mediterranean, and the first report of trace elements in minke whale and rough-toothed dolphin in the Mediterranean. Copyright © 2014 Elsevier Ltd. All rights reserved.

  6. Damage-induced permeability changes around underground excavations; Endommagement des roches argileuses et permeabilite induite au voisinage d'ouvrages souterrains

    Energy Technology Data Exchange (ETDEWEB)

    Coll, C

    2005-07-15

    The storage of nuclear waste in deep geological formations is now considered more and more as a potential solution. During excavation, a disturbed zone develops in which damaging can be important and which can lead eventually to the failure of the rock. Fluid flow and permeability in the rock mass can be significantly modified producing a possible security risk. Our work consisted in an experimental study of the hydro-mechanical coupling of two argillaceous rocks: Boom clay (Mol, Belgium) and Opalinus clay (Mont-Terri, Switzerland). Triaxial tests were performed in a saturated state to study the permeability evolution of both clays with isotropic and deviatoric stresses. Argillaceous rocks are geo-materials with complex behaviour governed by numerous coupled processes. Strong physico-chemical interactions between the fluid and the solid particles and their very low permeability required the modification of the experimental set up. Moreover, specific procedures were developed to measure permeability and to detect strain localisation in shear bands. We show that for Boom Clay, permeability is not significantly influenced by strain localisation. For Opalinus clay, fracturing can induce an increase of the permeability at low confining pressure. (author)

  7. Damage-induced permeability changes around underground excavations

    International Nuclear Information System (INIS)

    Coll, C.

    2005-07-01

    The storage of nuclear waste in deep geological formations is now considered more and more as a potential solution. During excavation, a disturbed zone develops in which damaging can be important and which can lead eventually to the failure of the rock. Fluid flow and permeability in the rock mass can be significantly modified producing a possible security risk. Our work consisted in an experimental study of the hydro-mechanical coupling of two argillaceous rocks: Boom clay (Mol, Belgium) and Opalinus clay (Mont-Terri, Switzerland). Triaxial tests were performed in a saturated state to study the permeability evolution of both clays with isotropic and deviatoric stresses. Argillaceous rocks are geo-materials with complex behaviour governed by numerous coupled processes. Strong physico-chemical interactions between the fluid and the solid particles and their very low permeability required the modification of the experimental set up. Moreover, specific procedures were developed to measure permeability and to detect strain localisation in shear bands. We show that for Boom Clay, permeability is not significantly influenced by strain localisation. For Opalinus clay, fracturing can induce an increase of the permeability at low confining pressure. (author)

  8. A minimalistic microbial food web in an excavated deep subsurface clay rock.

    Science.gov (United States)

    Bagnoud, Alexandre; de Bruijn, Ino; Andersson, Anders F; Diomidis, Nikitas; Leupin, Olivier X; Schwyn, Bernhard; Bernier-Latmani, Rizlan

    2016-01-01

    Clay rocks are being considered for radioactive waste disposal, but relatively little is known about the impact of microbes on the long-term safety of geological repositories. Thus, a more complete understanding of microbial community structure and function in these environments would provide further detail for the evaluation of the safety of geological disposal of radioactive waste in clay rocks. It would also provide a unique glimpse into a poorly studied deep subsurface microbial ecosystem. Previous studies concluded that microorganisms were present in pristine Opalinus Clay, but inactive. In this work, we describe the microbial community and assess the metabolic activities taking place within borehole water. Metagenomic sequencing and genome-binning of a porewater sample containing suspended clay particles revealed a remarkably simple heterotrophic microbial community, fueled by sedimentary organic carbon, mainly composed of two organisms: a Pseudomonas sp. fermenting bacterium growing on organic macromolecules and releasing organic acids and H2, and a sulfate-reducing Peptococcaceae able to oxidize organic molecules to CO(2). In Opalinus Clay, this microbial system likely thrives where pore space allows it. In a repository, this may occur where the clay rock has been locally damaged by excavation or in engineered backfills. © FEMS 2015. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  9. Damage-induced permeability changes around underground excavations; Endommagement des roches argileuses et permeabilite induite au voisinage d'ouvrages souterrains

    Energy Technology Data Exchange (ETDEWEB)

    Coll, C

    2005-07-15

    The storage of nuclear waste in deep geological formations is now considered more and more as a potential solution. During excavation, a disturbed zone develops in which damaging can be important and which can lead eventually to the failure of the rock. Fluid flow and permeability in the rock mass can be significantly modified producing a possible security risk. Our work consisted in an experimental study of the hydro-mechanical coupling of two argillaceous rocks: Boom clay (Mol, Belgium) and Opalinus clay (Mont-Terri, Switzerland). Triaxial tests were performed in a saturated state to study the permeability evolution of both clays with isotropic and deviatoric stresses. Argillaceous rocks are geo-materials with complex behaviour governed by numerous coupled processes. Strong physico-chemical interactions between the fluid and the solid particles and their very low permeability required the modification of the experimental set up. Moreover, specific procedures were developed to measure permeability and to detect strain localisation in shear bands. We show that for Boom Clay, permeability is not significantly influenced by strain localisation. For Opalinus clay, fracturing can induce an increase of the permeability at low confining pressure. (author)

  10. M-S-H precipitation in low-pH concretes in clayey environment

    International Nuclear Information System (INIS)

    Dauzeres, A.; Achiedo, G.; Nied, D.; L'Hopital, E.; Alahrache, S.; Lothenbach, B.

    2015-01-01

    In the framework of the CI-project (Cement Clay Interaction Experiment), two different low-pH cements were emplaced at Mont Terri rock laboratory to study their interactions with the surrounding Opalinus Clay (OPA): ESDRED (shotcrete mixture: 60% of CEM-I 42.5 N + 40% of silica fume + aluminium sulphate salt as accelerator) and LAC composed of CEM-III/B 42.5 L (60% of blast furnace slag + 10% nano silica). After 5 years of interactions in the Mont Terri rock laboratory, SEM-EDS analyses show a systematic Mg-perturbation associated with a high decalcification near the surface of both cementitious materials. TGA (Thermogravimetric Analysis) and XRD (X-ray diffraction) investigations associate this Mg-enrichment to the possible formation of M-S-H. This result is confirmed by 29 Si NMR analyses, showing a high polymerisation degree of the Si-network in the Mg-enriched zone typical of a sheet-like structure. Tem/EDS investigations of a FIB section carried out in the Mg zone of both LAC and ESDRED concretes indicate that the Mg phase exhibits a gel-like structure similar to C-S-H gel. This experimentally observed Mg-enrichment in the interaction zone is well reproduced by reactive transport modelling of the LAC/Opalinus clay with the HYTEC code. (authors)

  11. Sorption data bases for argillaceous rocks and bentonite for the provisional safety analyses for SGT-E2

    International Nuclear Information System (INIS)

    Baeyens, B.; Thoenen, T.; Bradbury, M. H.; Marques Fernandes, M.

    2014-11-01

    In Stage 1 of the Sectoral Plan for Deep Geological Repositories, four rock types have been identified as being suitable host rocks for a radioactive waste repository, namely, Opalinus Clay for a high-level (HLW) and a low- and intermediate-level (L/ILW) repository, and 'Brauner Dogger', Effingen Member and Helvetic Marls for a L/ILW repository. Sorption data bases (SDBs) for all of these host rocks are required for the provisional safety analyses, including all of the bounding porewater and mineralogical composition combinations. In addition, SDBs are needed for the rock formations lying below Opalinus Clay (lower confining units) and for the bentonite backfill in the HLW repository. In some previous work Bradbury et al. (2010) have described a methodology for developing sorption data bases for argillaceous rocks and compacted bentonite. The main factors influencing the sorption in such systems are the phyllosilicate mineral content, particular the 2:1 clay mineral content (illite/smectite/illite-smectite mixed layers) and the water chemistry which determines the radionuclide species in the aqueous phase. The source sorption data were taken predominantly from measurements on illite (or montmorillonite in the case of bentonite) and converted to the defined conditions in each system considered using a series of so called conversion factors to take into account differences in mineralogy, in pH and in radionuclide speciation. Finally, a Lab → Field conversion factor was applied to adapt sorption data measured in dispersed systems (batch experiments) to intact rock under in-situ conditions. This methodology to develop sorption data bases has been applied to the selected host rocks, lower confining units and compacted bentonite taking into account the mineralogical and porewater composition ranges defined. Confidence in the validity and correctness of this methodology has been built up through additional studies: (i) sorption values obtained in the manner

  12. Sorption data bases for argillaceous rocks and bentonite for the provisional safety analyses for SGT-E2

    Energy Technology Data Exchange (ETDEWEB)

    Baeyens, B.; Thoenen, T.; Bradbury, M. H.; Marques Fernandes, M.

    2014-11-15

    In Stage 1 of the Sectoral Plan for Deep Geological Repositories, four rock types have been identified as being suitable host rocks for a radioactive waste repository, namely, Opalinus Clay for a high-level (HLW) and a low- and intermediate-level (L/ILW) repository, and 'Brauner Dogger', Effingen Member and Helvetic Marls for a L/ILW repository. Sorption data bases (SDBs) for all of these host rocks are required for the provisional safety analyses, including all of the bounding porewater and mineralogical composition combinations. In addition, SDBs are needed for the rock formations lying below Opalinus Clay (lower confining units) and for the bentonite backfill in the HLW repository. In some previous work Bradbury et al. (2010) have described a methodology for developing sorption data bases for argillaceous rocks and compacted bentonite. The main factors influencing the sorption in such systems are the phyllosilicate mineral content, particular the 2:1 clay mineral content (illite/smectite/illite-smectite mixed layers) and the water chemistry which determines the radionuclide species in the aqueous phase. The source sorption data were taken predominantly from measurements on illite (or montmorillonite in the case of bentonite) and converted to the defined conditions in each system considered using a series of so called conversion factors to take into account differences in mineralogy, in pH and in radionuclide speciation. Finally, a Lab → Field conversion factor was applied to adapt sorption data measured in dispersed systems (batch experiments) to intact rock under in-situ conditions. This methodology to develop sorption data bases has been applied to the selected host rocks, lower confining units and compacted bentonite taking into account the mineralogical and porewater composition ranges defined. Confidence in the validity and correctness of this methodology has been built up through additional studies: (i) sorption values obtained in the manner

  13. Microbial analyses of clay and water from different samples from the Mont Terri Rock Laboratory (RL), Switzerland

    International Nuclear Information System (INIS)

    Sergeant, C.; Vesvres, M.H.; Barsotti, V.; Stroes-Gascoyne, S.; Hamon, C.J.; Neble, S.; Shippers, A.; Le Marrec, C.; Vinsot, A.; Schwyn, B.

    2010-01-01

    Document available in extended abstract form only. Exploration of deep subsurface microbial life has increased for very diverse motives. One of them is that these environments are potential host rocks for radioactive waste repositories and that microorganisms may influence geochemical conditions around such sites and migration properties of radionuclides. The pore water Chemistry experiment (PC) was conducted at the Mont Terri-RL to measure in situ the pH, Eh, and other geochemical parameters within the pore water of the Opalinus Clay formation. The borehole for PC was drilled with N 2 under clean but not aseptic conditions, filled immediately with synthetic pore water, which was circulated and monitored for five years. Soon after initiation of PC it was evident that microbial activity affected the borehole water geochemistry. Microbial analyses, including molecular biology and culturing methods, were performed repeatedly during PC (2003-2006), with detailed analysis of water and over-core clay upon termination in 2007. Results indicated the presence of heterotrophic aerobes and anaerobes, nitrate-reducers, iron-reducers, sulphate-reducers and Archaea, which together with geochemical data suggested a reducing environment with sulphate reduction in the water and adjacent clay. A black precipitate containing pyrite and a strong H 2 S smell confirmed the occurrence of sulphate reduction. Specific species identified (> 98% similarity) in PC water included Pseudomonas stutzeri, Bacillus licheniformis, and Desulfosporosinus sp., with similar and additional species (e.g., Trichococcus sp.; Koccuria sp.) in the clay. The origin of these (mostly anaerobic) species cannot be determined with certainty. Some species likely resulted from contamination, but others could be revived species indigenous in the Opalinus Clay. The microbial processes that occurred in PC are not representative of the processes in the undisturbed formation but illustrate the potential for microbial

  14. Thermal volume changes in clays and clay-stones

    International Nuclear Information System (INIS)

    Delage, P.; Sulem, J.; Mohajerani, M.; Tang, A.M.; Monfared, M.

    2012-01-01

    Document available in extended abstract form only. The disposal of high activity exothermic radioactive waste at great depth in clay host rocks will induce a temperature elevation that has been investigated in various underground research laboratories in Belgium, France and Switzerland through in-situ tests. Thermal effects are better known in clays (in particular Boom clay) than in clay-stone (e.g. Opalinus clay and Callovo-Oxfordian clay-stone). In terms of volume changes, Figure 1 confirms the findings of Hueckel and Baldi (1990) that volume changes depend on the over-consolidation ratio (OCR) of the clay. In drained conditions, normally consolidated clays exhibit plastic contraction when heated, whereas over-consolidated clay exhibit elastic dilation. The nature of thermal volume changes in heated clays obviously has a significant effect on thermally induced pore pressures, when drainage is not instantaneous like what occurs in-situ. Compared to clays, the thermal volume change behaviour of clay-stones is less well known than that of clays. clay-stone are a priori suspected to behave like over-consolidated clays. In this paper, a comparison of recent results obtained in the laboratory on the drained thermal volume changes of clay-stones is presented and discussed. It is difficult to run drained mechanical tests in clay-stones like the Opalinus clay and the Callovo-Oxfordian clay-stone because of their quite low permeability (10 -12 - 10 -13 m/s). This also holds true for thermal tests. Due to the significant difference in thermal expansion coefficient between minerals and water, it is necessary to adopt very slow heating rate (0.5 - 1 C/h) to avoid any thermal pressurization. To do so, a new hollow cylinder apparatus (100 mm external diameter, 60 mm internal diameter) with lateral drainages reducing the drainage length to half the sample thickness (10 mm) has been developed (Monfared et al. 2011). The results of a drained cyclic thermal test carried out on

  15. A pesca de pequena escala no rio Madeira pelos desembarques ocorridos em Manicoré (Estado do Amazonas, Brasil Small-scale fishery at Madeira River by fish landings in Manicoré city (Amazon State, Brazil

    Directory of Open Access Journals (Sweden)

    Renato Soares Cardoso

    2008-12-01

    Full Text Available O trabalho teve como objetivo analisar o desembarque da pesca comercial na região do Médio rio Madeira, tendo como área focal o município de Manicoré, buscando identificar as espécies explotadas, os locais de pesca e sua contribuição para o abastecimento local de pescado. O desembarque foi amostrado diariamente, utilizando questionários aplicados aos pescadores após a comercialização do pescado. Foram desembarcadas no ano de 2002 aproximadamente 225,4 toneladas de pescado. Canoas motorizadas efetuaram mais expedições de pesca, entretanto os barcos de pesca desembarcaram uma maior produção. Os valores médios de desembarque foram de 11,2; 5,4 e 2,4 toneladas por mês para barcos, canoas e compradores de pescado respectivamente, sendo as capturas compostas por 32 espécies ou grupo de espécies, sendo jaraqui (Semaprochilodus spp, pacu (Mylossoma duriventre, curimatá (Prochilodus nigricans, sardinha (Triportheus spp e jatuarana (Brycon spp, responsáveis por 75% do pescado desembarcado. Foram identificados 32 locais de pesca, sendo os mais explotados os rios Madeira e Manicoré, os lagos Acará e Boquerão e o igarapé Matupiri.The study aimed to analyze the landing of commercial fishing in Middle Madeira River, near Manicoré city, identifying the exploited species, fishing grounds and the contribution for the local supplying of fish. Fish landings were sampled daily, using questionnaires, given to fishermen after the fish sale. In 2002, 225.4 tons of fish were landed in Manicoré city. Motorized canoes undertook more fishing trips, but the higher fish landings were accomplished by boats. Mean values of fish landings were 11.2 tons/month, 5.4 tons/month and 2.4 tons/month for boats, motorized canoes and fish purchasers, respectively. 32 species or group of species were landed, with a predominance of jaraqui (Semaprochilodus spp, pacu (Mylossoma duriventre, curimatá (Prochilodus nigricans, sardinha (Triportheus spp e jatuarana

  16. Short-term cold storage of sperm from six neotropical characiformes fishes

    Directory of Open Access Journals (Sweden)

    Simone Marques

    2004-09-01

    Full Text Available Sperm of the following Neotropical Characiformes fish species were tested for cold storage: Brycon lundii, Piaractus mesopotamicus, Leporinus elongatus, Leporinus friderici, Prochilodus lineatus and Prochilodus marggravii. Each sperm sample was split into two aliquots. The first was placed into a plastic bag with air or oxygen and the second, in a plastic tube with air. The samples were maintained at temperatures between 1.7-4.9 ºC. The rate of sperm motility was estimated using a 50 mM NaCl solution as the activating solution. The shortest sperm storage duration (7 h was recorded for L. friderici, when the sperm motility rate reached ~ 30%, whereas the longest duration (20 h was obtained with the sperm of P. lineatus. A fertilisation test using Prochilodus marggravii sperm refrigerated for 8 h yielded 88-90% of viable embryos. The refrigerated storage method could be of practical applications, especially in fish reproductive management at hatchery stations.O sêmen das seguintes espécies de Characiformes neotropicais foi testado para armazenamento em ambiente resfriado: Brycon lundii, Piaractus mesopotamicus, Leporinus elongatus, Leporinus friderici, Prochilodus lineatus e Prochilodus marggravii. Amostras de sêmen, obtidas por massagem da parede celômica, foram armazenadas em saco plástico com ar ou oxigênio ou em tubo plástico com ar, e mantidas resfriadas entre 1,7-4,9º C. A taxa de motilidade espermática foi estimada usando-se NaCl 50 mM como solução ativadora. O sêmen com menor duração de viabilidade (7 h foi o de L. friderici, quando a taxa de motilidade espermática alcançou ~30%, enquanto que o de maior duração (20 h foi o de P. lineatus. A fertilização de ovócitos utilizando sêmen refrigerado por 8 h de Prochilodus marggravii produziu 88-90% de embriões viáveis. O método de armazenamento desenvolvido neste trabalho tem aplicações práticas, especialmente no manejo reprodutivo de peixes em estações de

  17. Fauna parasitária de peixes oriundos de “pesque-pague” do município de Guariba, São Paulo, Brasil - DOI: 10.4025/actascibiolsci.v28i3.253 Parasitic fauna of cultivated fishes in fee fishing farm of Guariba, São Paulo State, Brazil - DOI: 10.4025/actascibiolsci.v28i3.253

    Directory of Open Access Journals (Sweden)

    Julieta Rodini Engracia de Moraes

    2007-11-01

    Full Text Available Este trabalho descreve a ocorrência e a sazonalidade de parasitos em peixes de “pesque-pague” do município de Guariba, Estado de São Paulo, Brasil (21º15`22``S, 48º18`58``W e 595 m de altitude, durante o período de agosto de 2001 a julho de 2002. A presença de parasitos foi pesquisada em pacu Piaractus mesopotamicus (Characidae, carpa comum Cyprinus carpio (Cyprinidae, tilápia-do-Nilo Oreochromis niloticus (Cichlidae, híbrido tambacu (macho de P. mesopotamicus x fêmea de tambaqui-Colossoma macropomum e piraputanga Brycon hillari (Characidae. Os resultados demonstram que dos 100 peixes examinados, 15% estavam parasitados por pelo menos um dos seguintes parasitos: Trichodina sp.; helmintos monogenóides; copepoditos de Lernaea cyprinacea; L. cyprinacea adulta ou Dolops carvalhoi. Por ordem decrescente, o grau de suscetibilidade dos hospedeiros foi C. carpio, P. mesopotamicus, B. hillari, híbrido tambacu e O. niloticus. Por ordem decrescente, os parasitos encontrados foram helmintos monogenóides, Dolops carvalhoi, Trichodina sp., Lernaea cyprinacea adultas e suas formas jovens.This study describes the occurrence and the seasonality of parasites of cultivated fish from a fee fishing farm located in Guariba, São Paulo State, Brazil (21º15`22`` S, 48º18`58`` W and 595 m of altitude, from August, 2001 to July, 2002. The presence of parasites was researched in pacu Piaractus mesopotamicus (Characidae, common carp Cyprinus carpio (Cyprinidae, nile-tilapia Oreochromis niloticus (Cichlidae, tambacu hybrid (male of P. mesopotamicus x female of tambaqui-Colossoma macropomum and piraputanga Brycon hillari (Characidae. Results demonstrate that out of 100 fish examined, 15% were sponged for at least one of the following parasites: Trichodina sp.; monogenean helminths; copepodits of Lernaea cyprinacea; adults of L. cyprinacea; or Dolops carvalhoi. In decreasing order, the susceptibility degree of the hosts was C. carpio, P. mesopotamicus, B

  18. A pesca comercial na bacia do rio Madeira no estado de Rondônia, Amazônia brasileira The Commercial fisheries of the Madeira river basin in the Rondônia state, brazilian Amazon

    Directory of Open Access Journals (Sweden)

    Carolina Rodrigues da Costa Doria

    2012-03-01

    Full Text Available Este estudo caracteriza quali e quantitativamente a atividade pesqueira comercial na bacia do rio Madeira, afluente do rio Amazonas, no trecho entre Guajará-Mirim e Porto Velho, estado de Rondônia. No período de janeiro a dezembro/2004, foram registrados 460 t, correspondendo 935 viagens. A análise dos dados oriundos do monitoramento dos desembarques demonstrou que a pesca na região tem caráter artesanal de pequena escala, destacando a maior participação das canoas motorizadas (131 unidades do que barcos pesqueiros (45 unidades; capacidade média: 3.000kg na frota pesqueira. Os peixes migradores jaraqui (Semaprochilodus spp., dourada (Brachyplatystoma rousseauxii, sardinha (Triportheus spp., jatuarana/matrinxã (Brycon amazonicus e B. cephalus, curimatã (Prochilodus nigricans e filhote (Brachyplatystoma filamentosum se destacaram na composição das espécies desembarcadas. As informações técnicas geradas são importantes para subsidiar ações de ordenamento pesqueiro, bem como para avaliar futuras variações que possam ocorrer na atividade frente aos impactos dos empreendimentos hidrelétricos em construção na região.This study presents qualitative and quantitative information about commercial fishery in the basin of the Madeira River, tributary of the Amazon River, describing the fishing activity in the segment between Guajará-Mirim and Porto Velho, in Rondônia State. From January to December/2004, 219 fishermen and 935 trips were registered, corresponding to the capture of 460 t of fish. Data from fish landings demonstrate that fisheries in the region are small-scaled and point to a higher participation of small motorized canoes (130 units than of fishing boats (45 units; average capacity: 3000 kg in the fishing fleet. Migratory species like jaraqui (Semaprochilodus spp., dourada (Brachyplatystoma rousseauxii, sardinha (Triportheus spp., jatuarana/matrinxã (Brycon amazonicus e B. cephalus, curimatã (Prochilodus nigricans

  19. Benzocaína sobre respostas ao estresse do matrinxã submetido ao transporte em sacos plásticos Benzocaine on the stress response of matrinxã subjected to transport in plastic bags

    Directory of Open Access Journals (Sweden)

    Araceli Hackbarth

    2010-09-01

    Full Text Available O transporte é uma prática de manejo necessária em todas as estações de piscicultura. Entretanto, tal evento é um estímulo adverso e agudo, que interrompe o equilíbrio dos animais com o ambiente, de forma a promover o estresse. Alguns peixes de importância comercial, como o matrinxã (Brycon amazonicus, apresentam movimentação excessiva durante o manejo em geral, o que pode ocasionar consequências indesejáveis como perda de muco, de escamas, ferimentos e mortalidade. No presente trabalho, foi testado o anestésico benzocaína adicionado à água de transporte, como forma de reduzir estresse. Foram testadas duas concentrações de benzocaína, 10 e 15mg/L. Os resultados não mostraram efeitos de diminuição de estresse, apesar de a utilização da benzocaína ter reduzido a movimentação dos animais durante o transporte. As concentrações testadas podem ter aumentado o estresse por sofrimento respiratório, entretanto, o equilíbrio hidroeletrolítico não foi alterado, com sugestão de ação do anestésico sobre a liberação de catecolaminas.Transport is a necessary procedure in fish farming. However, it is an adverse and acute stimulus that breaks the balance between fish and environment, starting the stress condition. Some economic relevant species, as “matrinxã” (Brycon amazonicus, present excessive movements in handling, which may result in the unwanted consequences as loss of mucus, scales, injuries and death. In this work, the addition of the anesthetic benzocaine to the transport water was evaluated in juvenile “matrinxã”, in order to still the fish and possibly reducing stress. Two concentrations of benzocaine (10 and 15mg/L were tested. The results did not show any diminution of indices related to stress, notwithstanding the use of benzocaine during transport. Concentrations tested increased the stress responses by respiratory affliction, however, hydro-electrolytic balance was unaltered, being suggested some

  20. Effects of hot and cold smoking processes on organoleptic properties, yield and composition of matrinxa fillet Efeitos do processo de defumação a quente e a frio sobre as propriedades organolépticas, o rendimento e a composição de filé de matrinxã

    Directory of Open Access Journals (Sweden)

    Maria Luiza Rodrigues de Souza Franco

    2010-04-01

    Full Text Available The effects of hot (45-90ºC/5 hours and cold (27-45ºC/10 hours smoking processes on the organoleptic properties, yield and composition of matrinxa (Brycon cephalus fillets are evaluated. No significant differences were observed for fillet yield in both non-smoked and smoked fillets. Smoking process losses were significantly higher for hot smoked (19.37% when compared to cold smoked (17.08%. Smoking process reduced moisture (in natura = 72.91%, for hot = 58.51% and cold = 59.68% and increased crude protein, lipid and ash contents. However, there was a significant difference only for protein level between hot smoked (28.07% and cold smoked (27.14%. Cold smoked process resulted in better fillet appearance and color, while hot smoked presented superior flavor, salt content and general acceptance. Aroma and texture did not differ significantly among processes. Therefore, hot smoking process shows the best results for organoleptic properties and protein levels.Foi avaliado o efeito do processo de defumação a quente (45-90ºC/5 horas e a frio (27-45ºC/10 horas nas propriedades organolépticas, no rendimento e na composição dos filés de matrinxã (Brycon cephalus. Não houve diferença significativa no rendimento de filés defumados e não-defumados. As perdas no processo de defumação foram significativamente maiores para defumação a quente (19,37% em comparação à defumação a frio (17,08%. O processo de defumação reduziu a umidade (in natura = 72,91%; defumado a quente = 58,51%; e defumado a frio = 59,68% e aumentou os teores de proteína bruta, lipídios e cinzas. Houve diferença significativa somente nos teores de proteína no defumado a quente (28,07% e defumado a frio (27,14%. O processo a frio resultou em melhor aparência e cor de filé, enquanto o processo a quente melhorou o sabor, o teor de sal e a aparência geral. O aroma e a textura não diferiram significativamente entre os processos. O processo de defumação a quente

  1. Dismantling of the EB experiment: Experimental research on the retrieved GBM and bentonite blocks

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Jiang-Feng, E-mail: jeafliu@hotmail.com [State Key Laboratory for Geomchanics & Deep Underground Engineering, and School of Mechanics and Civil Engineering, China University of Mining & Technology, Xuzhou, Jiangsu 221116 (China); Laboratoire de Méchanique de Lille (LML), and École Centrale de Lille, BP 48, F-59651 Villeneuve d’Ascq Cedex (France); Skoczylas, Frédéric [Laboratoire de Méchanique de Lille (LML), and École Centrale de Lille, BP 48, F-59651 Villeneuve d’Ascq Cedex (France); Talandier, Jean [ANDRA, 1-7 rue Jean Monnet, 92298 Châtenay-Malabry Cedex (France); Pu, Hai [State Key Laboratory for Geomchanics & Deep Underground Engineering, and School of Mechanics and Civil Engineering, China University of Mining & Technology, Xuzhou, Jiangsu 221116 (China)

    2016-04-15

    Graphical abstract: - Highlights: • We present a demonstration of a new concept of HLW (high-level waste) repositories. • The hydro-mechanical characteristics of GBM and blocks were determined. • The water retention curves (WRCs) of GBM and blocks were presented. • The effective gas permeability of the GBM and blocks were measured. • The homogeneity of the GBM and blocks were investigated. - Abstract: The Engineered Barrier Emplacement Experiment in Opalinus Clay (EB experiment) was a full-scale test for the demonstration of a new concept of high-level waste (HLW) repositories in horizontal drifts in the Opalinus Clay formation. After 10.5 years of hydration, the EB experiment was dismantled in autumn 2012. Samples obtained from the granular bentonite material (GBM), and bentonite blocks were sent to a laboratory for further analysis. The bentonite samples analyzed at the Laboratory of Mechanic of Lille (LML) were obtained from the CMT1, CMT2, CMT3 and RW sections. Their physical states were determined, as were their effective gas permeability and swelling capacity at different relative humidity (RH) levels. The results indicate that the water contents of the GBM determined in the laboratory ranged between 25.63% and 44.88% and that the dry densities ranged between 1.13 and 1.44 g/cm{sup 3}. The blocks had water contents similar to (or slightly higher than) those of the GBM, and their dry densities had decreased from an initial value of 1.69 g/cm{sup 3} to values close to 1.30 g/cm{sup 3}, which were similar to the average values found in the GBM. The effective gas permeabilities of the GBM samples were within the range of 1.50 × 10{sup −22} m{sup 2} and 1.03 × 10{sup −17} m{sup 2}, whereas, the corresponding values of the samples obtained from the blocks were between 2.20 × 10{sup −21} m{sup 2} and 5.12 × 10{sup −21} m{sup 2}. The permeability values are primarily related to the dry densities and water contents of the samples. Contact with

  2. Multi-technical approach to characterize the dissolved organic matter from clay-stone

    International Nuclear Information System (INIS)

    Blanchart, Pascale; Michels, Raymond; Faure, Pierre; Parant, Stephane; Bruggeman, Christophe; De Craen, Mieke

    2012-01-01

    Document available in extended abstract form only. Currently, different clay formations (Boom Clay, Callovo-Oxfordian argilites, Opalinus Clay, Toarcian shales...) are studied as reference host rocks for methodological studies on the geological disposal of high-level and long-lived radioactive waste. While a significant effort is being done on the characterization of the mineral composition and the reactivity of the clays as barriers, the occurrence of organic matter, even in low proportion cannot be neglected. The organic matter appears as gas (C 1 -C 4 as identified in the Bure underground facilities), as solid (kerogen), as hydrocarbon liquids (free hydrocarbons within the kerogen or adsorbed on minerals) as well as in the aqueous phase (Dissolved Organic Matter - DOM). DOM raises specific interest, as it may have complexation properties towards metals and rare earth elements and is potentially mobile. Therefore, it is important to characterize the DOM as part of a study of feasibility of geological disposal. In this study, four host rocks were studied: - The Callovo-Oxfordian shales of Bure Underground Research Laboratory (Meuse, France); - The Opalinus Clay of Mont Terri Underground Research Laboratory (Switzerland); - The Toarcian shales of Tournemire (Aveyron, France); - The Boom Clay formation studied in The HADES Underground Research Laboratory (Mol, Belgium). Organic matter characteristics vary upon formation in terms of (i) origin (mainly marine type II; mixtures of marine type II and higher plants type III organic matter often poorly preserved), (ii) TOC contents, (iii) thermal maturity (for instance, Opalinus Clay and Toarcian shales are more mature and have poor oxygen content compare to Callovo-Oxfordian shales and Boom Clay). These differences in organic matter quality may have an influence on the quantity and the quality of DOM. The DOM of the rocks was isolated by Soxhlet extraction using pure water. A quantitative and qualitative multi

  3. Technetium migration in natural clays; Migration von Technetium in natuerlichem Tongestein

    Energy Technology Data Exchange (ETDEWEB)

    Luebke, Maria

    2015-10-01

    The present work was performed within the joint research project ''Retention of repository relevant radionuclides in argillaceous rocks and saline systems'' (contract no.: 02E10981), funded by the Federal Ministry for Economic Affairs and Energy (BMWi). The aim was to obtain first insights into the interaction of the long-lived fission product technetium and natural clay with regard to a repository for high-level nuclear waste. For this purpose Opalinus Clay from Mont Terri (northern Switzerland) was used as a reference material. The nuclide technetium-99 will contribute to the radiotoxicity of spent nuclear fuel for more than thousand years due to its long half-live. In case of a leakage of the storage vessels, the geochemistry of technetium is determined by its oxidation state, at which only the oxidation states +IV and +VII are relevant. Because of the high solubility and low affinity to sorption on surfaces of minerals, Tc(VII) is considered to be very mobile and thus the most hazardous species. The focuses of this study therefore are diffusion experiments with this mobile species and investigations of the effect of ferrous iron on the mobility and speciation of technetium.rnThe interaction of technetium and Opalinus Clay was studied in sorption and diffusion experiments varying several parameters (pH value, addition of reducing agents, effect of oxygen, diffusion pathways). In the course of this study spatially resolved investigations of the speciation have been performed on Opalinus Clay thin sections and bore cores for the first time. In addition to the speciation, further information regarding elemental distributions and crystalline phases near technetium enrichments were obtained. Supplementary investigations of powder samples allowed determining the molecular structure of technetium on the clay surface.rnBoth the combination of sorption experiments with spectroscopic investigations and the diffusion experiment exhibit a reduction of Tc

  4. Effect of temperature on damage and permeability of clayey soils and rocks

    International Nuclear Information System (INIS)

    Monfared, M.

    2011-04-01

    Storage of exothermic radioactive waste in deep low permeability geological formations such as clayey rocks and plastic clays is a solution considered for long term repositories. However the excavation of underground galleries creates a damaged zone (EDZ). The effect of the damage zone on the transport properties of the geological barrier has been widely studied. Within the framework of the TIMODAZ European project, emphasis has been put on the effect of temperature. As a partner of this project, the current work is performed to investigate the coupling effect between temperature, damage and permeability on Boom clay and Opalinus clay through an experimental study. View to the experimental difficulties related to the low permeability materials, a new hollow cylinder triaxial cell with short drainage path specifically designed to study the thermo-hydro-mechanical behaviour of very low permeable materials is developed during this work. The tests and the numerical analysis show that the short sample drainage path reduces significantly the time needed to re-saturate an initially unsaturated sample and it also permits to achieve drained conditions (i.e. negligible excess pore pressure during testing) with a higher loading rate. For Boom clay, the effect of the pore water thermal pressurisation on a sample with a pre-existing shear band is investigated. The undrained heating under shear stress decreases the effective stress on the sample which leads to its failure. An existing failure plane in the sample behaves like a preferential weakness plane which can be reactivated by pore water thermal pressurisation. The estimated shearing resistance along the sheared plane is smaller than that of the intact material. For the Opalinus clay-stone, drained heating on a saturated sample shows that this clay-stone behaves like a slightly over consolidated material (thermo-elasto-plastic behaviour) with transition from expansion to contraction at 65 C. The decrease of the permeability

  5. Technetium migration in natural clays

    International Nuclear Information System (INIS)

    Luebke, Maria

    2015-01-01

    The present work was performed within the joint research project ''Retention of repository relevant radionuclides in argillaceous rocks and saline systems'' (contract no.: 02E10981), funded by the Federal Ministry for Economic Affairs and Energy (BMWi). The aim was to obtain first insights into the interaction of the long-lived fission product technetium and natural clay with regard to a repository for high-level nuclear waste. For this purpose Opalinus Clay from Mont Terri (northern Switzerland) was used as a reference material. The nuclide technetium-99 will contribute to the radiotoxicity of spent nuclear fuel for more than thousand years due to its long half-live. In case of a leakage of the storage vessels, the geochemistry of technetium is determined by its oxidation state, at which only the oxidation states +IV and +VII are relevant. Because of the high solubility and low affinity to sorption on surfaces of minerals, Tc(VII) is considered to be very mobile and thus the most hazardous species. The focuses of this study therefore are diffusion experiments with this mobile species and investigations of the effect of ferrous iron on the mobility and speciation of technetium.rnThe interaction of technetium and Opalinus Clay was studied in sorption and diffusion experiments varying several parameters (pH value, addition of reducing agents, effect of oxygen, diffusion pathways). In the course of this study spatially resolved investigations of the speciation have been performed on Opalinus Clay thin sections and bore cores for the first time. In addition to the speciation, further information regarding elemental distributions and crystalline phases near technetium enrichments were obtained. Supplementary investigations of powder samples allowed determining the molecular structure of technetium on the clay surface.rnBoth the combination of sorption experiments with spectroscopic investigations and the diffusion experiment exhibit a reduction of Tc

  6. BIOCHEMICAL PARAMETERS FOR Piaractus mesopotamicus, Colossoma macropomum (Characidae AND HYBRID TAMBACU (P. mesopotamicus X C. macropomum

    Directory of Open Access Journals (Sweden)

    Marcos Tavares-Dias

    2010-06-01

    Full Text Available A study for investigating the values of plasma glucose,serum total protein and serum ions (calcium, potassium, magnesium,sodium and chloride was carried out in young Colossomomamacropomum Cuvier, 1818, Piaractus mesopotamicus Holmberg,1887 and the hybrid tambacu (P. mesopotamicus x C. macropomum,kept in intensive system. Glucose concentrations were higher intambacu than in P. mesopotamicus and C. macropomum. Totalprotein levels were higher in P. mesopotamicus than both C.macropomum and tambacu. C. macropomum presented higherconcentrations of sodium and chloride, while P. mesopotamicushad higher concentrations of potassium and magnesium.However, levels of calcium were similar for the species studied.The hybrid tambacu showed the smallest levels of total protein,and intermediate levels of sodium, potassium, magnesium andchloride, compared to both P. mesopotamicus and C. macropomum.Baseline values for healthy fish in aquaculture were established,and they may be used for further comparisons in studies with wildpopulations of P. mesopotamicus and C. macropomum.

  7. Strontium-90 and cesium-137 in sea fish (from Nov. 1984 to Jun. 1985)

    International Nuclear Information System (INIS)

    1985-01-01

    Sr-90 and Cs-137 in sea fish were determined using radiochemical analysis. Seven species of fish (Branchiostegus sp., Katsuwonus pelamis, Limanda herzensteini, Sillago sihama, Scomber japonicus, Caesio chrysozonus cuvier, and Sebastes Inermis) were collected during the fishing season from nine sampling locations. Only the edible part was used in cases of larger sized fish, and the whole part was used in cases of smaller ones. Each sample was weighed and placed in a stainless steel pan or a porcelain dish. After carbonization, the sample was ashed in an electric muffle furnace. The maximum value of Sr-90 was 0.9 +- 0.26 pCi/kg in Limanda herzensteini collected from Hiroshima in March 1985; and that of Cs-137 was 12 +- 0.5 pCi/kg in Katsuwonus pelamis collected from Kochi in May 1985. (Namekawa, K.)

  8. Zooarqueologia dos mamíferos aquáticos e semi-aquáticos da Ilha de Santa Catarina, sul do Brasil

    Directory of Open Access Journals (Sweden)

    Pedro Volkmer de Castilho

    2001-09-01

    Full Text Available This study analyzes the use of aquatic mammals by prehistoric societies of Santa Catarina Island, Southern Brazil. Samples from two archaeological sites were examined: Rio do Meio (RM and Porto do Rio Vermelho (SCPRV. Nine aquatic mammal species were found: a pinnipeds: Arctocephalus australis (Zimmerman, 1783 and A. tropicalis (Gray, 1872, and b cetaceans: Eubalaena australis (Desmoulins, 1822, Delphinus delphis Linnaeus, 1758, Stenella frontalis (Cuvier, 1829, Steno bredanensis (Lesson, 1828, Tursiops truncatus (Montagu, 1821, Pontoporia blainvillei (Gervais & d'Orbigny, 1844 and a non-identified rorqual from the genus Balaenoptera Lacépède, 1804. Three especies of semi-aquatic mammals were also recorded: Hydrochoerus hydrochaeris (Linnaeus, 1758, Tapirus terrestris (Linnaeus, 1758 and Lontra longicaudis (Olfers,1818. Both sites presented similar species diversity, although abundance was greater at the most recent site (RM. There were more samples from axial skeletons, but in genera the anatomical regions were homogeneously distributed among the identified taxa.

  9. Rebuttal to Koeda et al. (2014) on the Red Sea fishes of the perciform genus Pempheris.

    Science.gov (United States)

    Randall, John E; Victor, Benjamin C; Alpermann, Tilman J; Bogorodsky, Sergey V; Mal, Ahmad O; Satapoomin, Ukkrit; Bineesh, K K

    2014-11-25

    Koeda et al. (2014) published a review of fishes of the genus Pempheris of the Red Sea. They concluded that there are four species: P. adusta Bleeker, P. mangula Cuvier, P. nesogallica Cuvier, and a new species, P. tominagai. We show that the first three species they cite are not present in the Red Sea, as follows. 1) P. adusta is a western Pacific species (type locality Ambon), described only from the holotype, and without a dark border on the anal fin. Koeda et al. (2014) mistakenly apply that name to P. flavicycla which is a widespread Indian Ocean species characterized by a prominent broad black border along the anal fin. Koeda et al. (2014) also redescribe P. adusta, using Indian Ocean specimens of P. flavicycla, despite the coloration difference and a 2.5% difference in the mtDNA sequence (COI) between Indian Ocean and W. Pacific populations. 2) P. mangula is a species from the east coast of India (type locality Visakhapatnam), clearly distinct in both gill-raker counts and a 1.1% sequence divergence in COI from its Red Sea relative P. rhomboidea. Pempheris mangula is not found west of India, and Koeda et al. (2014) mistakenly use DNA from Oman and Madagascar to represent P. mangula, instead of genetic material available from the type locality. 3) Pempheris nesogallica (type locality Mauritius) is unknown from the Red Sea. Koeda et al. (2014) separate P. nesogallica from P. rhomboidea (their "P. mangula") by eye size; we fail to find any difference (and they use their purported eye-size difference to erroneously rename one of the two syntypes of P. nesogallica as "P. mangula"). 4) Their new species P. tominagai is referred to as the Indian Ocean sister species of "P. schwenkii of the Pacific"; however, the type locality of P. schwenkii is the Batu Islands off the SW coast of Sumatra in the Indian Ocean. They mistakenly include specimens of a distant South African species as paratypes of P. tominagai. We have determined that P. tominagai is a valid species

  10. A comparison of the heart and muscle total lipid and fatty acid profiles of nine large shark species from the east coast of South Africa.

    Science.gov (United States)

    Davidson, Bruce; Sidell, Jonathan; Rhodes, Jeffrey; Cliff, Geremy

    2011-03-01

    We have assessed the fatty acid profiles of the hearts and different muscle tissues from nine large shark species (Carcharhinus limbatus (blacktip), Carcharhinus obscurus (dusky), Carcharhinus brevipinna (spinner), Carcharhinus leucas (Zambezi/bull), Galeocerdo cuvier (tiger), Sphyrna lewini (scalloped hammerhead), Sphyrna zygaena (smooth hammerhead), Carcharodon carcharias (great white) and Carcharias taurus (raggedtooth/grey nurse/sand tiger)) found off the east coast of South Africa. While there was generally little variation between the species, all species showed profiles rich in both n6 and n3 polyunsaturated fatty acids compared to terrestrial commercial meats that have low n3. Thus, utilizing skeletal muscle tissues from sharks caught as part of the bycatch when fishing for teleosts would avoid unnecessary wastage of a potentially valuable resource, with all the possible health benefits of high quality protein combined with balanced polyunsaturates, although contamination with high levels of metabolic wastes, such as urea, may be a negative consideration.

  11. Strontium-90 and cesium-137 in sea fish from Nov. 1983 to Jun. 1984

    International Nuclear Information System (INIS)

    1984-01-01

    Sr-90 and Cs-137 in sea fish were determined using radiochemical analysis. Seven species of fish (Branchiostegus sp., Katsuwonus pelamis, Limanda herzensteini, Sillago sihama, Pneumatophorus japonicus, Caesio chrysozonus cuvier, and Sebastes Inermis) were collected during the fishing season from 8 sampling locations. Only the edible part was used in case of larger sized fish, and the whole part was used in case of smaller ones. Each sample was weighed and placed in a stainless steel pan or a porcelain dish. After carbonized, the sample was ashed in an electric muffle furnace. The maximum values of Sr-90 was 1.0+-0.25 pCi/kg in Sebastes Inermis collected from Yamaguchi in April 1984; the maximum value of Cs-137 was 14.0+-0.60 pCi/kg in Katsuwonus pelamis collected from Kochi in May 1984. (Namekawa, K.)

  12. Gideon Mantell and the Discovery of Dinosaurs

    Science.gov (United States)

    Dean, Dennis R.

    1999-01-01

    Gideon Mantell and the Discovery of Dinosaurs is a scholarly yet accessible biography--the first in a generation--of a pioneering dinosaur hunter and scholar. Gideon Mantell discovered the Iguanodon (a famous tale set right in this book) and several other dinosaur species, spent over twenty-five years restoring Iguanodon fossils, and helped establish the idea of an Age of Reptiles that ended with their extinction at the conclusion of the Mesozoic Era. He had significant interaction with such well-known figures as James Parkinson, Georges Cuvier, Charles Lyell, Roderick Murchison, Charles Darwin, and Richard Owen. Dennis Dean, a well-known scholar of geology and the Victorian era, here places Mantell's career in its cultural context, employing original research in archives throughout the world, including the previously unexamined Mantell family papers in New Zealand.

  13. A new Huffmanela species, H. schouteni sp. n. (Nematoda: Trichosomoididae) from flying fishes in Curaçao.

    Science.gov (United States)

    Moravec, F; Campbell, B G

    1991-01-01

    A new nematode species, Huffmanela schouteni sp. n., has been established on the basis of its egg morphology and biological characters (adult nematodes are unknown). The dark-shelled eggs of this histozoic parasite occur in masses in the abdominal cavity, serose covers of internal organs and in the liver of the flying fishes Hirundichthys affinis Günther (type host) and Cypselurus cyanopterus Cuvier et Valenciennes in Curaçao. The eggs of H. schouteni sp. n. differ from those in other congeneric species mainly in the absence of small spines on the surface of the transparent envelope enclosing the egg proper, measurements (size of eggs 0.069-0.075 x 0.027-0.030 mm) and their localization in the host. A key to Huffmanela species based on egg morphology has been provided.

  14. Ectoparasites of bats (Chiroptera, Furipteridae, with a description of a new species of Synthesiostrebla Townsend (Diptera, Streblidae from Brazil

    Directory of Open Access Journals (Sweden)

    Gustavo Graciolli

    2011-12-01

    Full Text Available Ectoparasites of bats (Chiroptera, Furipteridae, with a description of a new species of Synthesiostrebla Townsend (Diptera, Streblidae from Brazil. Records of ectoparasites from furipterid bats are restricted to bat flies (Streblidae. Only three streblid species were known before this work: Trichobius pallidus (Curran, 1934, Strebla wiedemanni Kolenati, 1856, and Synthesiostrebla amorphochili Townsend, 1913. A second species of Synthesiostrebla is described here, increasing the geographical distribution of the genus to east of the Andes. Synthesiostrebla cisandina sp. nov. was found on Furipterus horrens (Cuvier, 1828 in southeastern Brazil. Anterior parts of the body, wing, tergite 7, epiproct and male genitalia are illustrated, and a key to females for species of Synthesiostrebla is provided.

  15. Larval fish in the surf zone of Pontal do Sul beach, Pontal do Paraná, Paraná, Brazil

    Directory of Open Access Journals (Sweden)

    Rodrigo Santiago Godefroid

    1999-01-01

    Full Text Available A total of 6,575 larvae in the preflexion, flexion and post-flexion stages of 15 families, 26 genera and 29 species were captured in the surf zone of Pontal do Sul beach, Paraná, Brazil. Samples of the families Gerreidae and Scianidae predominated and larvae of Eucinostomus argenteus (Baird&Girard, 1854, Micropogonias furnieri (Desmarest, 1823, Eucinostomus gula (Cuvier, 1830, Menticirrhus ameri-canus (Linnaeus, 1758 and Anchoa tricolor (Agassiz, 1829 were the most dominant species. Greater abundance of larvae was observed during the summer, followed by winter and in a less extent during spring and autumn. The number of species was greater in the summer, and there were no significant differences in the rest of the seasons.

  16. Don quijote, Christelike geloof en natuurwetenskap 1

    Directory of Open Access Journals (Sweden)

    H. P.P. Lötter

    1987-03-01

    Full Text Available The story about Don Qulchote and the windmills is used in this article as an analogy to typify the debates that have taken place in history between natural science and representatives of Christian religion. The analogy is tested on debates that took place around Galileo. Darwin, Newton, Cuvier and the Big Bang theory. The analogy matches these debates quite well and this Is explained by the view that scientific claims to knowledge, and claims to knowledge based on Christian faith, belong to different categories and are thus not concurrents for the same truth. Gilbert Ryle's criticism on Descartes' mind-body dualism is used here to strengthen this argument. The article is concluded by pointing out in what ways one can engage in a meaningful debate on the nature of the relationship between science and Christian religion.

  17. The diet of the South American sea lion (Otaria flavescens at Río Negro, Patagonia, Argentina, during the winter-spring period Dieta del lobo marino de un pelo sudamericano (Otaria flavescens en Río Negro, Patagonia, Argentina, durante el invierno y primavera

    Directory of Open Access Journals (Sweden)

    Raimundo L. Bustos

    2012-12-01

    Full Text Available The South American sea lion, Otaria flavescens (Shaw, 1800 population is steadily expanding along the Patagonian coast of Argentina in the last decades. However, little is known about the feeding ecology of the species in the area. The aim of this study was to analyze the food habits of O. flavescens from 91 scats collected at Río Negro province, during the winter and spring of 2005. Fish occurred in 96% of scats containing prey remains, followed by cephalopods (26%. Raneya brasiliensis (Kaup, 1856 was the most frequent and abundant species occurring in 58.6% of samples and constituting almost 50% of fish predated. Second in importance were Porichthys porosissimus (Cuvier, 1829 and Cynoscion guatucupa (Cuvier, 1830 in terms of occurrence (%FO 20.7 and numbers (29.6% respectively. The squid Loligo gahi (d'Orbigny, 1835 was the most frequent cephalopod prey (42.1%, whereas Octopus tehuelchus (d'Orbigny, 1834 was the most abundant (77%. The higher amount and diversity of prey found in the spring in comparison with the winter season might be related to a higher feeding activity of seals or to a seasonal increase in food availability in the area.La población del lobo marino de un pelo sudamericano Otaria flavescens (Shaw, 1800 ha experimentado un crecimiento continuo en las ultimas décadas en las costas de la Patagonia Argentina. Sin embargo, poco se conoce sobre la ecología trófica de la especie en el área. El objetivo de este estudio fue analizar los hábitos alimentarios de O. flavescens a partir de 91 fecas colectadas en la provincia de Río Negro, durante el invierno y la primavera del 2005. Los peces estuvieron presentes en el 96% de las fecas que contenían remanentes presas, seguidos por los cefalópodos (26%. Raneya brasiliensis (Kaup, 1856 fue la especie mas frecuente y abundante ocurriendo en el 58.6% de las muestras y constituyendo casi el 50% de los peces predados. Le siguieron en importancia Porichthys porosissimus (Cuvier, 1829 y

  18. Studies on the eggs and larvae, of Sardinella aurita (Cuv. & Val.) in the fishing grounds of Southern Fujian and the Taiwan Bank

    Science.gov (United States)

    Jiang, Sufei; Lin, Liyu

    1986-03-01

    In this paper, the morphological characters of eggs and larvae of Sardinella aurita (Cuvier & Valenciennes), its spawning ground, spawning seasons and spawning conditions have been studied. Sardinella aurita likes to breed in the upwelling area and selects the Waixie fishing ground as its main spawning ground. The months from February to September are its spawning seasons, reaching its peak in April. In the main spawning ground, the temperature of the surface layer was found to be 24.4 25.2°C, the salinity 33.87 34.07%. and the depth of water between 34 60m. The distribution of the larvae is closely related to the distribution of plankton, the path of migration of adult fish, and the current direction of the water system. In order to protect fishery resources, it is necessary to prohibit catching the spawning fish in the Waixie fishing ground in April, and the catching of immatures from March to June.

  19. A new species of Cacatuocotyle (Monogenea, Dactylogyridae) parasitizing Astyanax spp. (Characiformes, Characidae) from Brazil, including molecular data and a key to species identification.

    Science.gov (United States)

    Zago, Aline Cristina; Franceschini, Lidiane; Müller, Maria Isabel; Silva, Reinaldo José da

    2018-06-26

    The present study describes Cacatuocotyle papilionis n. sp. (Monogenea, Dactylogyridae) from the skin of the characid fishes Astyanax lacustris (Lütken, 1875) (=Astyanax altiparanae Garutti & Britski, 2000) and Astyanax fasciatus (Cuvier, 1819) (Characiformes, Characidae) from the Southeast of Brazil, supported by morphological and molecular data. The new species differs from all congeners, mainly due to the morphology of the ventral bar (resembling a butterfly), accessory piece, and the number of rings of the male copulatory organ (MCO), comprising a coiled tube with 4.5-5.5 counterclockwise rings. The first molecular data for this monogenean genus is provided in this study, using the partial sequences of the ribosomal gene (28S), as well as providing an identification key to the species.

  20. Complete mitochondrial genome and phylogenetic position of the Sicklefin weasel shark Hemigaleus microstoma.

    Science.gov (United States)

    Mai, Quanfa; Li, Weidong; Chen, Hao; Ai, Weiming; Chen, Xiao

    2016-09-01

    The complete mitochondrial genome of the Sicklefin weasel shark Hemigaleus microstoma was first presented in this study. It was 16 701 bp in length with the typical gene arrangement in vertebrates. A total of 25 bp short intergenic spaces and 33 bp overlaps located in 12 and 9 gene junctions, respectively. The overall nucleotide composition was 31.0% A, 26.4% C, 13.5% G and 29.1% T. Two start (ATG and GTG) and three stop (TAG, AGG and TAA/T) codons were found in the protein-coding genes. The size of 22 tRNA genes ranged from 67 to 75 bp. In the phylogenetic tree, H. microstoma (Hemigaleidae) was placed as sister to Galeocerdo cuvier (Carcharhinidae).

  1. Elemental characterization of tissues of Octopus vulgaris along the Portuguese coast.

    Science.gov (United States)

    Napoleão, P; Pinheiro, T; Sousa Reis, C

    2005-06-01

    The concentrations of V, Mn, Fe, Ni, Cu, Zn, As, Se, Mo, and Pb were measured in digestive gland (DG), branchial hearts (BH), gill (G), and muscle (M) of Octopus vulgaris Cuvier, 1797 caught in three fishing areas of the Portuguese coast, Viana do Castelo, Cascais, and Santa Luzia, for 2 years. The elemental concentrations measured for the different tissues were in accordance with values reported in the literature. The digestive gland presented high concentration levels of Fe, Cu, and Zn, while the branchial hearts showed elevated levels of V, Ni, Mo, as well as Fe and Cu. Significant variations in As, V, Cu, Mo, and Pb tissue concentrations were observed for animals originated from different sampling sites. Pb and As determined in the digestive gland and branchial hearts of animals from Cascais and Santa Luzia, can reflect local environmental characteristics. The variability observed in the elemental concentrations may be useful to further assess the species susceptibility to environmental conditions.

  2. Cicatrization of the damaged zone around a tunnel in low permeable rocks; Cicatrisation de la zone endommagee autour du tunnel dans des roches peu permeables

    Energy Technology Data Exchange (ETDEWEB)

    Hamza, R.O

    2005-12-15

    Three types of clays have been studied in this work: the Mol clay (plastic clay), the Mont Terri clay (opalinus clay) and the East clay (stiff clay). This work is divided into three parts: an experimental part which has allowed to identify the cicatrization phenomenon and the cracks closing. Through several tests has been determined the evolution of the permeability of the clayey samples which are undamaged or damaged with time and according to the different applied hydro-mechanical loadings. In order to describe the cicatrization phenomenon, a rheological law has been developed from the experimental observations and under some hypotheses. The parameters of the cicatrization model have been determined by numerical simulation. In order to take into account the structures effects at a large scale, the modelling of a tunnel has allowed to better identify the cicatrization phenomenon and to analyze the long term stability of this work. (O.M.)

  3. H, HM, and THM-C processes in natural barriers

    Energy Technology Data Exchange (ETDEWEB)

    Javeri, V.; Le, T.T.; Cui, Y.J.; Delage, P.; Li, X.J.; Wieczorek, K.; Jockwer, N.; Romero, E.; Lima, A.; Gens, A.; Li, X.L.; Francois, B.; Nuth, M.; Laloui, L.; Chen, W.; Jia, S.; Yu, H.; Wu, G.; Li, X.; Bernier, F.; Tan, X.; Wu, G.; Jia, S.; Giot, R.; Hoxha, D.; Giraud, A.; Homand, F.; Su, K.; Chavant, C.; Duveau, G.; Jia, Y.; Shao, J.F.; Peron, H.; Laloui, L.; Hueckel, T.; Hu, L.B.; Auvray, C.; Lequiller, B.; Cuisinier, O.; Ferber, V.; Cui, Y.J.; Deneele, D.; Uhlig, L.; Jobmann, M.; Polster, M.; Vaunat, J.; Garrite, B.; Wileveau, Y.; Sato, H.; Jacinto, A.; Sanchez, M.; Ledesma, A.; Morel, J.; Balland, C.; Armand, G.; Nguyen Minh, D.; Vales, F.; Pham, Q.T.; Gharbi, H.; Mokni, N.; Olivella, S.; Li, X.; Smets, St.; Valcke, E.; Karnland, O.; Nilsson, U.; Olsson, S.; Sellin, P.; Fernandez, A.M.; Melon, A.M.; Villar, M.V.; Turrero, M.J.; Garitte, B.; Guimaraes, L.D.N.; Gens, A.; Mayor, J.C.; Koliji, A.; Laloui, L.; Vulliet, L.; Hamdi, N.; Marzouki, A.; Srasra, E.; Cuss, R.J.; Harrington, J.F.; Noy, D.J.; Birchall, D.J.; Marschall, P.; Mallet, A.; Ababou, R.; Matray, J.M.; Renaud, V.; Maison, T.; Enachescu, C.; Frieg, B.; Rohs, St.; Paris, B.; Robinet, J.C.; Bui, T.D.; Barnichon, J.D.; Plas, F.; Klubertanz, G.; Folly, M.; Hufschmied, P.; Frank, E

    2007-07-01

    This session gathers 30 articles (posters) dealing with: the three Dimensional analyses of combined gas, heat and nuclide transport in a repository considering coupled thermo-hydro geomechanical processes; the experimental study on the thermo-hydro-mechanical behaviour of boom clay; hydraulic in-situ measurements in the Opalinus clay in the frame of a heater test performed at the Mont Terri URL; the hydro-mechanical behaviour of natural boom clay in controlled-suction tests; a constitutive approach to address the thermal and hydric impacts in the concept of deep radioactive waste repositories; the numerical analysis on stability of boom clay tunnel by shield construction; a thermo-hydro-mechanical model for clay in unsaturated conditions; the 3D modelling of TER experiment accounting for fully anisotropic thermo-poro-elastic behaviour; the hydro-mechanical modeling of shaft excavation in Meuse/Haute-Marne laboratory; the modelling of drying damage in engineered and natural clay barriers for nuclear waste disposal; the elasto-viscoplastic behaviour of Meuse/Haute-Marne argillite: laboratory tests and modelling; the long-term behaviour of a lime treated soil under percolation conditions; the stress redistribution and hydro-mechanical effects due to excavation and drilling operations in TER experiment; a thermodynamic model on swelling of bentonite buffer and backfill materials; the 3D analysis of a heating test in the Opalinus clay; the THM analysis of a 'mock-up' laboratory experiment using a double-structure expansive model; the measurement of the effect of re-confinement on rock properties around a slot; a laboratory Study of desaturation - re-saturation effects on a clay-stone; the deformation induced by dissolution of salts in porous media; the bentonite swelling pressure in pure water and saline solutions; the mineralogy and sealing properties of various bentonites and smectite-rich clay materials; the evaluation of the geochemical processes occurring

  4. Extraction of 3D velocity and porosity fields from GeoPET data sets

    Energy Technology Data Exchange (ETDEWEB)

    Lippmann-Pipke, Johanna; Kulenkampff, Johannes [Helmholtz-Zentrum Dresden-Rossendorf e.V., Dresden (Germany). Reactive Transport; Eichelbaum, S. [Nemtics Visualization, Leipzig (Germany)

    2017-06-01

    Geoscientific process monitoring with positron emission tomography (GeoPET) is proven to be applicable for quantitative tomographic transport process monitoring in natural geological materials. We benchmarked GeoPET by inversely fitting a numerical finite element model to a diffusive transport experiment in Opalinus clay. The obtained effective diffusion coefficients, D{sub e}, parallel and D{sub e}, perpendicular to, are well in line with data from literature. But more complex, heterogeneous migration, and flow patterns cannot be similarly evaluated by inverse fitting using optimization tools. Alternatively, we started developing an algorithm that allows the quantitative extraction of velocity and porosity fields, v{sub i=x,y,z} (x,y,z) and n(x,y,z) from GeoPET time series, c{sub PET}(x,y,z,t). They may serve as constituent data sets for reactive transport modelling.

  5. Bentonite. Geotechnical barrier and source for microbial life

    Energy Technology Data Exchange (ETDEWEB)

    Matschiavelli, Nicole; Kluge, Sindy; Cherkouk, Andrea [Helmholtz-Zentrum Dresden-Rossendorf e.V., Dresden (Germany). HZDR Young Investigator Group; Steglich, Jennifer

    2017-06-01

    Due to their properties, namely a high swelling capacity and a low hydraulic conductivity, Bentonites fulfil as geotechnical barrier a sealing and buffering function in the nuclear waste repository. Depending on the mineral composition Bentonites contain many suitable electron-donors and -acceptors, enabling potential microbial life. For the potential repository of highly radioactive waste the microbial mediated transformation of Bentonite could influence its properties as a barrier material. Microcosms were set up containing Bentonite and anaerobic synthetic Opalinus-clay-pore water solution under an N{sub 2}/CO{sub 2}-atmosphere to elucidate the microbial potential within selected Bentonites. Substrates like acetate and lactate were supplemented to stimulate potential microbial activity. First results show that bentonites represent a source for microbial life, demonstrated by the consumption of lactate and the formation of pyruvate. Furthermore, microbial iron-reduction was determined, which plays a crucial role in Betonite-transformation.

  6. The role of quality management in safety case development - Nagra's experience

    International Nuclear Information System (INIS)

    Schneider, Juerg W.; Zuidema, Piet

    2014-01-01

    This paper discusses the role of quality management (QM) in safety case development based on Nagra's experience from a broad range of projects. These include Project Gewahr (L/ILW and HLW, Nagra, 1985), the Wellenberg Project (L/ILW, Nagra, 1994), Project Opalinus Clay (HLW, Nagra, 2002a, 2002b), and recent project work needed in the context of the Swiss site selection process (L/ILW and HLW, Nagra, 2008a, 2008b, 2008c, 2010). Broadly speaking, Nagra's Quality Management policy is focused on ensuring: i) the quality of the disposal system (siting, design and implementation); ii) the quality of the underlying scientific understanding, which are seen as key elements of a credible safety case, along with the quality of the safety calculations themselves and of compiling the safety case, including the drawing of conclusions (Nagra, 2002a). All aspects of QM discussed in this paper should be seen in this context. (authors)

  7. Investigations of Near-Field Thermal-Hydrologic-Mechanical-Chemical Models for Radioactive Waste Disposal in Clay/Shale Rock

    International Nuclear Information System (INIS)

    Liu, H.H.; Li, L.; Zheng, L.; Houseworth, J.E.; Rutqvist, J.

    2011-01-01

    Clay/shale has been considered as potential host rock for geological disposal of high-level radioactive waste throughout the world, because of its low permeability, low diffusion coefficient, high retention capacity for radionuclides, and capability to self-seal fractures. For example, Callovo-Oxfordian argillites at the Bure site, France (Fouche et al., 2004), Toarcian argillites at the Tournemire site, France (Patriarche et al., 2004), Opalinus Clay at the Mont Terri site, Switzerland (Meier et al., 2000), and Boom clay at the Mol site, Belgium (Barnichon and Volckaert, 2003) have all been under intensive scientific investigation (at both field and laboratory scales) for understanding a variety of rock properties and their relationships to flow and transport processes associated with geological disposal of radioactive waste. Figure 1-1 presents the distribution of clay/shale formations within the USA.

  8. From clay bricks to deep underground storage

    International Nuclear Information System (INIS)

    2012-05-01

    This booklet issued by the Swiss National Cooperative for the Disposal of Radioactive Waste NAGRA takes a look at the use of clay strata for the storage of radioactive wastes in deep-lying repositories. First of all, a geological foray is made concerning the history of the use of clay and its multifarious uses. The characteristics of clay and its composition are examined and its formation in the geological past is explained. In particular Opalinus clay is looked at and the structures to be found are discussed. The clay's various properties and industrial uses are examined and its sealing properties are examined. Also, Bentonite clay is mentioned and work done by Nagra and co-researchers is noted

  9. Safety-relevant assessment concerning the proposals for investigations in proposed locations for stage 3 of the deep geological repositories project; Sicherheitstechnisches Gutachten zum Vorschlag der in Etappe 3 SGT weiter zu untersuchenden geologischen Standortgebiete - Sachplan geologische Tiefenlager, Etappe 2

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2017-04-15

    This comprehensive report published by the Swiss Federal Nuclear Safety Inspectorate ENSI examines the proposals made by the Swiss National Cooperative for the disposal of Radioactive Waste (NAGRA) concerning proposed locations for deep waste repositories. Important basic considerations to be made when narrowing down the choice of host rock types and the selection of possible locations are discussed. These include, amongst others, safety concepts for the repositories, geological models and technical feasibility of repositories in Opalinus Clay, Brown Dogger layers and marl. The properties of various host rocks are discussed. Methods to be used in choosing at least two possible sites for repositories are considered. Also, the radioactive dosage to be expected at the various sites proposed is discussed. A safety-relevant comparison of the sites is made and an overall assessment is presented. The locations proposed for surface facilities at three proposed locations are discussed. The report is completed with an appendix containing tables and a list of relevant expert reports.

  10. Decommissioning and disposal costs in Switzerland

    International Nuclear Information System (INIS)

    Zurkinden, Auguste

    2003-01-01

    Introduction Goal: Secure sufficient financial resources. Question: How much money is needed? Mean: Concrete plans for decommissioning and waste disposal. - It is the task of the operators to elaborate these plans and to evaluate the corresponding costs - Plans and costs are to be reviewed by the authorities Decommissioning Plans and Costs - Comprise decommissioning, dismantling and management (including disposal) of the waste. - New studies 2001 for each Swiss nuclear power plant (KKB 2 x 380 MWe, KKM 370 MWe, KKG 1020 MWe, KKL 1180 MWe). - Studies performed by NIS (D). - Last developments taken into account (Niederaichbach, Gundremmingen, Kahl). Decommissioning: Results and Review Results: Total cost estimates decreasing (billion CHF) 1994 1998 2001 13.7 13.1 11.8 Lower costs for spent fuel conditioning and BE/HAA/LMA repository (Opalinus Clay) Split in 2025: 5.6 bil. CHF paid by NPP 6.2 billion CHF in Fund Review: Concentrates on disposal, ongoing

  11. Bentonite. Geotechnical barrier and source for microbial life

    International Nuclear Information System (INIS)

    Matschiavelli, Nicole; Kluge, Sindy; Cherkouk, Andrea; Steglich, Jennifer

    2017-01-01

    Due to their properties, namely a high swelling capacity and a low hydraulic conductivity, Bentonites fulfil as geotechnical barrier a sealing and buffering function in the nuclear waste repository. Depending on the mineral composition Bentonites contain many suitable electron-donors and -acceptors, enabling potential microbial life. For the potential repository of highly radioactive waste the microbial mediated transformation of Bentonite could influence its properties as a barrier material. Microcosms were set up containing Bentonite and anaerobic synthetic Opalinus-clay-pore water solution under an N_2/CO_2-atmosphere to elucidate the microbial potential within selected Bentonites. Substrates like acetate and lactate were supplemented to stimulate potential microbial activity. First results show that bentonites represent a source for microbial life, demonstrated by the consumption of lactate and the formation of pyruvate. Furthermore, microbial iron-reduction was determined, which plays a crucial role in Betonite-transformation.

  12. Investigations of Near-Field Thermal-Hydrologic-Mechanical-Chemical Models for Radioactive Waste Disposal in Clay/Shale Rock

    Energy Technology Data Exchange (ETDEWEB)

    Liu, H.H.; Li, L.; Zheng, L.; Houseworth, J.E.; Rutqvist, J.

    2011-06-20

    Clay/shale has been considered as potential host rock for geological disposal of high-level radioactive waste throughout the world, because of its low permeability, low diffusion coefficient, high retention capacity for radionuclides, and capability to self-seal fractures. For example, Callovo-Oxfordian argillites at the Bure site, France (Fouche et al., 2004), Toarcian argillites at the Tournemire site, France (Patriarche et al., 2004), Opalinus Clay at the Mont Terri site, Switzerland (Meier et al., 2000), and Boom clay at the Mol site, Belgium (Barnichon and Volckaert, 2003) have all been under intensive scientific investigation (at both field and laboratory scales) for understanding a variety of rock properties and their relationships to flow and transport processes associated with geological disposal of radioactive waste. Figure 1-1 presents the distribution of clay/shale formations within the USA.

  13. Biogeochemical processes in a clay formation in situ experiment: Part G - Key interpretations and conclusions. Implications for repository safety

    Energy Technology Data Exchange (ETDEWEB)

    Wersin, P., E-mail: paul.wersin@gruner.ch [NAGRA, Hardstrasse 73, 5430 Wettingen (Switzerland)] [Gruner Ltd., Gellertstrasse 55, 4020 Basel (Switzerland); Stroes-Gascoyne, S. [Atomic Energy of Canada Limited (AECL), Whiteshell Laboratories, Pinawa, Manitoba, Canada R0E 1L0 (Canada); Pearson, F.J. [Ground-Water Geochemistry, 5108 Trent Woods Drive, New Bern, NC 28562 (United States); Tournassat, C. [BRGM, French Geological Survey, 3 Avenue Claude Guillemin, B.P. 36009, 45060 Orleans Cedex 2 (France); Leupin, O.X.; Schwyn, B. [NAGRA, Hardstrasse 73, 5430 Wettingen (Switzerland)

    2011-06-15

    Highlights: > From the results of the PC experiment it can be inferred that degradation of organic compounds may induce. > Changes in pH and Eh which may affect the mobility of radionuclides eventually released from the waste. > Such changes will be limited in space and time because of large buffering capacity and low permeability of clay. > Nevertheless, amount of organic material in high level waste repositories should be kept small. > This will ensure achievement of background concentrations within short time period after repository closure. - Abstract: The in situ porewater chemistry (PC) experiment carried out in the Opalinus Clay formation at the Mont Terri Rock Laboratory, Switzerland for a period of 5 a allowed the identification and quantification of the biogeochemical processes resulting from and affected by an anaerobic microbial disturbance. The unintentional release of degradable organic compounds (mainly glycerol) induced microbially-mediated SO{sub 4} reduction in the borehole with concomitant significant geochemical changes in the circulating water and the adjacent porewater. These changes included a decrease in SO{sub 4}{sup 2-} concentration and pH and an increase in pCO{sub 2} and alkalinity relative to the non-affected formation water. However, the cation composition of the water and the mineralogy of the clay close to the borehole wall showed very little change. This is explained by (1) the strong chemical buffering processes in the clay and (2) by the diffusion-limited flux of solutes. With the aid of a reactive transport model with a minimum set of kinetic parameters for the hypothesised degradation reactions, the evolution of solutes in the borehole could be modelled adequately. The model was also applied to the prediction of restoration times upon depletion of the C source and results indicated restoration times to undisturbed conditions of about 15 a, but also highlighted the rather large uncertainties inherent in the geochemical model

  14. Applying squeezing technique to clay-rocks: lessons learned from ten years experiments at Mont Terri

    International Nuclear Information System (INIS)

    Fernandez, A. M.; Melon, A.; Sanchez-Ledesma, D.M.; Tournassat, C.; Gaucher, E.; Astudillo, J.; Vinsot, A.

    2012-01-01

    Document available in extended abstract form only. Argillaceous formations of low permeability are considered in several countries as potential host rocks for the disposal of high level radioactive wastes (HLRW). In order to determine their suitability for waste disposal, evaluations of the hydro-geochemistry and transport mechanisms from such geologic formations to the biosphere must be undertaken. The migration of radionuclides through the geosphere will occur predominantly in the aqueous phase, and hence the pore water chemistry plays an important role in determining ion diffusion characteristics in argillaceous formations. Consequently, a great effort has been made to characterise the pore water chemistry in clay-rocks formations. In the last 10 years various techniques were developed for determining pore water composition of clay-rocks including both direct and indirect methods: 1) In situ pore water sampling (water and gas) from sealed boreholes (Pearson et al., 2003; Vinsot et al. 2008); 2) Laboratory pore water sampling from unaltered core samples by the squeezing technique at high pressures (Fernandez et al., 2009); and 3) Characterization of the water chemistry by geochemical modelling (Gaucher et al. 2009). Pore water chemistry in clay-rocks and extraction techniques were documented and reviewed in different studies (Sacchi et al., 2001). Recovering pristine pore water from low permeable and low water content systems is very difficult and sometimes impossible. Besides, uncertainties are associated to each method used for the pore water characterization. In this paper, a review about the high pressure squeezing technique applied to indurate clay-rocks was performed. For this purpose, the experimental work on Opalinus Clay at the Mont Terri Research Laboratory during the last ten years was evaluated. A complete discussion was made about different issues such as: a) why is necessary to obtain the pore water by squeezing in the context of radioactive waste

  15. Assessment of geomechanical properties, maximum depth and excavation damaged zone aspects - Expert report

    International Nuclear Information System (INIS)

    Amann, F.; Löw, S.; Perras, M.

    2015-11-01

    This comprehensive report published by the Swiss National Nuclear Safety Inspectorate ENSI discusses the expert report published on the need for the assessment of geomechanical properties and maximum depth of repositories for high, medium and low-activity nuclear wastes. Also, aspects concerning excavation damaged zones (EDZ) are considered. These are all criteria for the selection of sites as part of Phase 2 of the Swiss waste disposal project. Four questions are examined: are NAGRA’s documented basic considerations and calculations on Opalinus Clay comprehensive enough and correct, are the calculations on maximum depth correct, are the proposed storage perimeters correct with respect to depth and will NAGRA be able to take possible excavation damaged zones (EDZ) into account? Literature and references concerning the subject are quoted

  16. ENSI's view on NTB 08-02 'Report on how to handle the recommendations in expert reports and statements of views on the demonstration of the nuclear waste disposal programme'

    International Nuclear Information System (INIS)

    2012-03-01

    In the framework of a review of the project Opalinus clay for the disposal of spent fuel assemblies, high-level radioactive waste and long living intermediate-level waste, a team of experts worked out numerous recommendations to be considered in the future. In 2006, the Swiss Federal Council stated that the realization of a radioactive waste disposal had been demonstrated to be possible. At the same time, the operators of the Swiss nuclear power plants were instructed to answer the open questions and to decide how they would proceed in the future. Similarly, the National Cooperative for the Disposal of Radioactive Waste (NAGRA) presented a report which ENSI had to review and evaluate. This review is reported in the present document. The NAGRA report, as well as ENSI's comments, is structured in accordance with the 200 recommendations made by the experts' team. ENSI states that the recommendations and all open questions of the experts' team were treated completely and transparently by NAGRA; they were considered in the elaboration of proposals for underground storage sites. ENSI declares that the recommendations for the demonstration of the feasibility of the waste disposal were given the correct priority. An important mile stone for more precise indications about site specific data will be the future request for the granting of the framework license, at the end of the site selection process, according to the Sectoral Plan for Geologic Deep Repositories. The recommendations about Opalinus clay as host rock are of general nature. They concern a repository for high-level (HLW) waste as well as for low- and intermediate-level (ILW) wastes. They also concern techniques independent of the host rock, like how to handle filling and sealing material. In step 1 of the Sectoral Plan, besides the Opalinus clay NAGRA proposed exclusively clay-rich host rocks with similar properties. Opalinus clay was proposed for 5 of the 6 potential disposal sites for a ILW repository. Some

  17. Cicatrization of the damaged zone around a tunnel in low permeable rocks

    International Nuclear Information System (INIS)

    Hamza, R.O.

    2005-12-01

    Three types of clays have been studied in this work: the Mol clay (plastic clay), the Mont Terri clay (opalinus clay) and the East clay (stiff clay). This work is divided into three parts: an experimental part which has allowed to identify the cicatrization phenomenon and the cracks closing. Through several tests has been determined the evolution of the permeability of the clayey samples which are undamaged or damaged with time and according to the different applied hydro-mechanical loadings. In order to describe the cicatrization phenomenon, a rheological law has been developed from the experimental observations and under some hypotheses. The parameters of the cicatrization model have been determined by numerical simulation. In order to take into account the structures effects at a large scale, the modelling of a tunnel has allowed to better identify the cicatrization phenomenon and to analyze the long term stability of this work. (O.M.)

  18. From clay bricks to deep underground storage; vom lehmziegel bis zum tiefenlager -- anwendung von ton

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2012-05-15

    This booklet issued by the Swiss National Cooperative for the Disposal of Radioactive Waste NAGRA takes a look at the use of clay strata for the storage of radioactive wastes in deep-lying repositories. First of all, a geological foray is made concerning the history of the use of clay and its multifarious uses. The characteristics of clay and its composition are examined and its formation in the geological past is explained. In particular Opalinus clay is looked at and the structures to be found are discussed. The clay's various properties and industrial uses are examined and its sealing properties are examined. Also, Bentonite clay is mentioned and work done by Nagra and co-researchers is noted.

  19. The contribution of tracers in understanding transportation processes in indurated argillaceous formations

    International Nuclear Information System (INIS)

    Savoye, Sebastien

    2008-01-01

    In a first part, the author recalls briefly the properties of the two argillaceous formations studied in this HDR report: the Toarcian/Domerian argillite and the Opalinus clay of Mont Terri. At first, have been described the two undamaged argillite materials and then the damaged Tournemire argillite. The second part gives the results obtained from the researches on the undamaged rock with natural tracers and with approaches using artificial tracers. The third part deals with the study of the damaged rock in separating natural perturbations of those of anthropogenic origin. At last, the conclusion gives the guiding thema of this research work and the main long-term future prospects that may result. (O.M.)

  20. Cymothoa recifea sp. nov. (Isopoda, Cymothoidae from the mouths of marine fishes of Pernambuco State, Brazil Cymothoa recifea sp. nov. (Isopoda, Cymothoidae das bocas de peixes marinhos do Estado de Pernambuco, Brasil

    Directory of Open Access Journals (Sweden)

    Vernon E. Thatcher

    2005-09-01

    Full Text Available Cymothoa recifea sp. nov. (Isopoda, Cymothoidae is described from the mouths of Centropomus undecimalis (Bloch, 1792 and Oligoplites palometa (Cuvier, 1832. The fish hosts were caught near Itamaracá and Cabo de Santo Agostinho, State of Pernambuco, Brazil. The new species bears a superficial resemblance to Cymothoa oestrum (Linnaeus, 1793 from which it differs in a number of important respects. In the new species, the basal carinae are large on pereopods 4-7 and usually pointed, whereas in C. oestrum the carinae are small on pereopods 4-6, large on 7 and not pointed. In the new species, only pleopod 1 is simple and 2-5 are provided with pockets and folds. In the other species, pleopods 1-4 are simple and only 5 has folds.Cymothoa recifea sp. nov. (Isopoda, Cymothoidae é descrito das bocas de Centropomus undecimalis (Bloch, 1792 e Oligoplites palometa (Cuvier, 1832. Os peixes foram capturados perto de Itamaracá, Estado de Pernambuco, Brasil. A nova espécie apresenta uma semelhança superficial à Cymothoa oestrum (Linnaeus, 1793 da qual distingue-se pôr várias características. Na nova espécie, as expansões nas bases dos pereópodos ("carinae" são grandes nos 4-7 e, geralmente, terminam em pontas agudas. Em contraste, em C. oestrum, estas estruturas são pequenas nos pereópodos 4-6, grande somente no sétimo e não têm pontas agudas. Na nova espécie, somente o pleópodo 1 é simples e 2-5 apresentam bolsas e dobras. Na outra espécie, os pleópodos 1-4 são simples e somente 5 tem dobras.

  1. Parasitic copepods on Oligoplites spp. (Osteichthyes, Carangidae from the Brazilian coastal zone, with the redescription of Tuxophorus caligodes Wilson, 1908 (Siphonostomatoida, Tuxophoridae Copépodes parasitos de Oligoplites spp. (Osteichthyes, Carangidae da costa brasileira, com a redescrição de Tuxophorus caligodes Wilson, 1908 (Siphonostomatoida, Tuxophoridae

    Directory of Open Access Journals (Sweden)

    Ricardo Massato Takemoto

    2002-05-01

    Full Text Available Four species of caligid copepods, parasites of Oligoplites palometa (Cuvier, 1833, O. saurus (Bloch & Schneider, 1801 and O. saliens (Bloch, 1793 (Osteichthyes: Carangidae from the Sepetiba Bay, coast of the state of Rio de Janeiro, Brazil, are presented. New geographical and host records for Caligus robustus Bassett-Smith, 1898, C. rufimaculatus Wilson, 1905, C. bonito Wilson, 1905 and Metacaligus rufus (Wilson, 1908 are given. Caligus oligoplitisi Carvalho, 1954 is considered a new junior synonym of C. robustus. Fishes of the genus Oligoplites are new host records for this species of copepod. Redescription and illustration of Tuxophorus caligodes Wilson, 1908, collected on the body surface of Oligoplites saliens, O. palometa and O. saurus, are provided.Quatro espécies de copépodes caligídeos, parasitos de Oligoplites palometa (Cuvier, 1833, O. saurus (Bloch & Schneider, 1801 e O. saliens (Bloch, 1793 (Osteichthyes, Carangidae da Baia de Sepetiba, litoral do Estado do Rio de Janeiro, Brasil, são descritos. São apresentados o registro de novo hospedeiro e nova distribuição geográfica para Caligus robustus Bassett-Smith, 1898, C. rufimaculatus Wilson, 1905, C. bonito Wilson, 1905 e Metacaligus rufus (Wilson, 1908. Caligus oligoplitisi Carvalho, 1954, é considerado novo sinônimo júnior de C. robustus. Tuxophorus caligodes Wilson, 1908, coletado na superfície do corpo de Oligoplites saliens, O. palometa e O. saurus é redescrito e ilustrado. Peixes do gênero Oligoplites são novos hospedeiros para estas espécies de copépodes.

  2. Species distribution models of tropical deep-sea snappers.

    Directory of Open Access Journals (Sweden)

    Céline Gomez

    Full Text Available Deep-sea fisheries provide an important source of protein to Pacific Island countries and territories that are highly dependent on fish for food security. However, spatial management of these deep-sea habitats is hindered by insufficient data. We developed species distribution models using spatially limited presence data for the main harvested species in the Western Central Pacific Ocean. We used bathymetric and water temperature data to develop presence-only species distribution models for the commercially exploited deep-sea snappers Etelis Cuvier 1828, Pristipomoides Valenciennes 1830, and Aphareus Cuvier 1830. We evaluated the performance of four different algorithms (CTA, GLM, MARS, and MAXENT within the BIOMOD framework to obtain an ensemble of predicted distributions. We projected these predictions across the Western Central Pacific Ocean to produce maps of potential deep-sea snapper distributions in 32 countries and territories. Depth was consistently the best predictor of presence for all species groups across all models. Bathymetric slope was consistently the poorest predictor. Temperature at depth was a good predictor of presence for GLM only. Model precision was highest for MAXENT and CTA. There were strong regional patterns in predicted distribution of suitable habitat, with the largest areas of suitable habitat (> 35% of the Exclusive Economic Zone predicted in seven South Pacific countries and territories (Fiji, Matthew & Hunter, Nauru, New Caledonia, Tonga, Vanuatu and Wallis & Futuna. Predicted habitat also varied among species, with the proportion of predicted habitat highest for Aphareus and lowest for Etelis. Despite data paucity, the relationship between deep-sea snapper presence and their environments was sufficiently strong to predict their distribution across a large area of the Pacific Ocean. Our results therefore provide a strong baseline for designing monitoring programs that balance resource exploitation and

  3. Diet of the fishing bat Noctilio leporinus (Linnaeus (Mammalia, Chiroptera in a mangrove area of southern Brazil Dieta do morcego-pescador Noctilio leporinus (Linnaeus (Mammalia, Chiroptera em uma área de manguezal do sul do Brasil

    Directory of Open Access Journals (Sweden)

    Marcelo O. Bordignon

    2006-03-01

    Full Text Available From January to December 1999, the diet of Noctilio leporinus (Linnaeus, 1758 was determined in a salt-water ecosystem, by analysing the feces of bats captured in mist nets. Of the 61 samples analyzed, most contained remains of fish (90.2%, followed by insects (70.5% and crustaceous (29.5%. The most frequent fishes species were: silversides Atherinella brasiliensis (Quoy & Gaimard, 1825, anchovies Cetengraulis edentulus (Cuvier, 1829 and scaly sardines Ophisthonema oglinum (Lesueur, 1818. The most frequent insects were moths (Saturniidae and beetles (Cerambycidae, Scarabaeidae and Coccinellidae, as well as two species of bat ectoparasites (Streblidae. Among the crustaceous the shrimp (Palaemonidae and crabs (Gecarcinidae are was present. The consumption of fish, insects and crustaceans was different for the males and females throughout the year.De janeiro a dezembro de 1999, foi estudada a dieta de Noctilio leporinus (Linnaeus, 1758 em um ecossistema de manguezal, através da análise das fezes de morcegos capturados com redes-neblina. Das 61 amostras analisadas, a maioria continha fragmentos de peixes (90.2%, seguido de insetos (70.5% e crustáceos (29,5%. As espécies de peixes mais freqüentes foram: peixe-rei Atherinella brasiliensis (Quoy & Gaimard, 1825, manjuba Cetengraulis edentulus (Cuvier, 1829 e sardinha Ophisthonema oglinum (Lesueur, 1818. Os insetos mais freqüentes foram mariposas (Saturniidae e besouros (Cerambycidae, Scarabaeidae e Coccinellidae, além de duas espécies de ectoparasitas (Streblidae. Entre os crustáceos, houve a presença apenas de camarões (Palaemonidae e siris (Gecarcinidae. O consumo de peixes, insetos e crustáceos foi diferente para machos e fêmeas ao longo do ano.

  4. Acleotrema lamothei n. sp. (Monogenea: Diplectanidae from the gills of Kyphosus incisor in Brazilian waters Acleotrema lamothei n. sp. (Monogenea: Diplectanidae de las branquias de Kyphosus incisor en aguas brasileñas

    Directory of Open Access Journals (Sweden)

    Cláudia P. Santos

    2008-08-01

    Full Text Available A diplectanid monogenean, Acleotrema lamothei n. sp., is described from the gills of the yellow sea chub Kyphosus incisor (Cuvier, 1831 in Brazilian waters off Rio de Janeiro State. This species is distinguished by the facts that the male copulatory organ is armed with spines throughout most of its length, the ventral hamuli have a very long, stout outer root, which is slightly notched proximally, an inner root less than half the length of the outer root and a fine blade and point. It also differs from most species of the genus by the greater size of the haptor and its hard parts. This is the first record of a species of Acleotrema Johnston and Tiegs, 1922 from South American waters.Se describe Acleotrema lamothei n. sp. de las branquias del pez Kyphosus incisor (Cuvier, 1831 recolectado en las costas del estado de Río de Janeiro, Brasil. La nueva especie se distingue por la armadura del órgano copulador con espinas en casi toda su longitud, por la presencia de una raíz externa larga y robusta en el hámuli ventral, provista de una pequeña muesca proximal, por la raíz interna que mide menos de la mitad de la longitud de la externa y por tener la hoja y la punta finas. Asimismo, difiere de muchas de las especies del género por el gran tamaño del haptor y de sus partes esclerozadas. El presente constituye el primer registro de una especie de Acleotrema Johnston y Tiegs, 1922 en aguas sudamericanas.

  5. A note on the occurrence of praniza larvae of Gnathiidae (Crustacea, Isopoda on fishes from Northeast of Pará, Brazil

    Directory of Open Access Journals (Sweden)

    Daniel G. Diniz

    2008-12-01

    Full Text Available The infection of the estuarine teleost fishes Mugil gaimardianus Desmarest, 1831 (Mugilidae, Arius phrygiatus Valenciennes, 1839 (Ariidae, Conodon nobilis Linnaeus, 1759 (Haemulidae, Cetengraulis edentulus Cuvier, 1829 (Engraulidae, and Anableps anableps Linnaeus, 1758 (Anablepidae by praniza larvae of Gnathiidae (Crustacea, Isopoda was studied in specimens fished off the Atlantic Ocean in Northeast of Pará State, near Bragança, Brazil. The highest infection prevalence value was found in Anableps anableps (42.3% and the lowest in Conodon nobilis (9.1%. The mean intensity varied from 1 parasitein Conodon nobilis to 19.5 in Arius phrygiatus. A description of the larvae is provided. The morphology of the mouthparts is related to the blood sucking activity, and is compared with the characteristics of other gnathiidae species.Foi estudada a parasitose dos peixes estuarinos Mugil gaimardianus Desmarest, 1831 (Mugilidae, Arius phrygiatus Valenciennes, 1839 (Ariidae, Conodon nobilis Linnaeus, 1759 (Haemulidae, Cetengraulis edentulus Cuvier, 1829 (Engraulidae, e Anableps anableps Linnaeus, 1758 (Anablepidae por larvas praniza de Gnathiidae (Crustacea, Isopoda em exemplares pescados no Oceano Atlântico, no Nordeste do Pará, próximo a Bragança, Brasil. O valor mais elevado da prevalência da infecção foi observado em A. anableps (42,3% e o menor em C. nobilis (9,1%. A intensidade média da parasitose variou entre 1 parasita em C. nobilis até 19,5 em A. phrygiatus. Efetua-se a descrição da larva, verificando-se que a morfologia da armadura bucal está relacionada com a atividade sugadora de sangue, e faz-se a comparação com as características de outras espécies.

  6. Quantifying shark distribution patterns and species-habitat associations: implications of marine park zoning.

    Science.gov (United States)

    Espinoza, Mario; Cappo, Mike; Heupel, Michelle R; Tobin, Andrew J; Simpfendorfer, Colin A

    2014-01-01

    Quantifying shark distribution patterns and species-specific habitat associations in response to geographic and environmental drivers is critical to assessing risk of exposure to fishing, habitat degradation, and the effects of climate change. The present study examined shark distribution patterns, species-habitat associations, and marine reserve use with baited remote underwater video stations (BRUVS) along the entire Great Barrier Reef Marine Park (GBRMP) over a ten year period. Overall, 21 species of sharks from five families and two orders were recorded. Grey reef Carcharhinus amblyrhynchos, silvertip C. albimarginatus, tiger Galeocerdo cuvier, and sliteye Loxodon macrorhinus sharks were the most abundant species (>64% of shark abundances). Multivariate regression trees showed that hard coral cover produced the primary split separating shark assemblages. Four indicator species had consistently higher abundances and contributed to explaining most of the differences in shark assemblages: C. amblyrhynchos, C. albimarginatus, G. cuvier, and whitetip reef Triaenodon obesus sharks. Relative distance along the GBRMP had the greatest influence on shark occurrence and species richness, which increased at both ends of the sampling range (southern and northern sites) relative to intermediate latitudes. Hard coral cover and distance across the shelf were also important predictors of shark distribution. The relative abundance of sharks was significantly higher in non-fished sites, highlighting the conservation value and benefits of the GBRMP zoning. However, our results also showed that hard coral cover had a large effect on the abundance of reef-associated shark species, indicating that coral reef health may be important for the success of marine protected areas. Therefore, understanding shark distribution patterns, species-habitat associations, and the drivers responsible for those patterns is essential for developing sound management and conservation approaches.

  7. Estudos de cestóides de peixes do Brasil

    Directory of Open Access Journals (Sweden)

    A. Arandas Rego

    1974-01-01

    Full Text Available Os autores iniciam com este trabalho um estudo sistemático de determinação dos cestóides de peixes depositados na Coleção helmintológica do Instituto Oswaldo Cruz. São referidas ou descritas as seguintes espécies e seus hospedeiros: Schizochoerus liguloideus (Diesing, 1850 e Nesolecithus janicki Posche, 1922, ambas de Arapaima gigas (Cuvier, (piracuru; Gyrocotyle meandrica Herrera, 1946, de Callorhynchus callorhynchus (L., (quimera; Acanthobothrium dasybati Yamaguti, 1934 e Pterobothriidae não identificado, de uma arraia não determinada; três tipos larvares de trypanorrhyncha e um de Proteocephalidea, de Cynoscion striatus (Cuv. e C. leiarchus (pescadinha; Proteocephalus jandia Woodland, 1934, de um bagre não determinado. Monticellia siluri (Fuhrmann, 1916 e Amphoteromorphus praeputialis sp. n. de Cetopsis caecutiens e Nomimoscolex magna sp. n. de Pimelodus clarias (mandi.The authors start, with this note, a systematic study for determination of cestodes of fishes of the Helminthological Collection of the Instituto Oswaldo Cruz. The following species and hosts are refered and described: Schizochoerus liguloideus (Diesing, 1850 and Nesolecithus janicki poche, 1922 both of Arapaima gigas (Cuvier; Gyrocotyle meandrica Herrera, 1946 of Callorhynchus callorhynchus (L.,Acanthobothrium dasybati Yamaguti, 1934 and Pterobothriidae unidentified, of an indeterminate ray; three types of larvae of Trypanorrhyncha and type of Proteocephalidea, of Cynoscion striatus (Cuv. and C. leiarchus; Proteocephalus jandia Woodland, 1934 of an indeterminate catfish; Monticellia siluri (Furhrmann, 1916 and Amphoteromorphus praeputialis sp. n. of Cetopsis caecutiens and Nomimoscolex magna sp. n. of Pimelodus clarias.

  8. Biogeochemical processes in a clay formation in situ experiment: Part F - Reactive transport modelling

    Energy Technology Data Exchange (ETDEWEB)

    Tournassat, Christophe, E-mail: c.tournassat@brgm.fr [BRGM, French Geological Survey, Orleans (France); Alt-Epping, Peter [Rock-Water Interaction Group, Institute of Geological Sciences, University of Bern (Switzerland); Gaucher, Eric C. [BRGM, French Geological Survey, Orleans (France); Gimmi, Thomas [Rock-Water Interaction Group, Institute of Geological Sciences, University of Bern (Switzerland)] [Laboratory for Waste Management, Paul Scherrer Institut, Villigen (Switzerland); Leupin, Olivier X. [NAGRA, CH-5430 Wettingen (Switzerland); Wersin, Paul [Gruner Ltd., CH-4020 Basel (Switzerland)

    2011-06-15

    Highlights: > Reactive transport modelling was used to simulate simultaneously solute transport, thermodynamic reactions, ion exchange and biodegradation during an in-situ experiment in a clay-rock formation. > Opalinus clay formation has a high buffering capacity in terms of chemical perturbations caused by bacterial activity. > Buffering capacity is mainly attributed to the carbonate system and to the reactivity of clay surfaces (cation exchange, pH buffering). - Abstract: Reactive transport modelling was used to simulate solute transport, thermodynamic reactions, ion exchange and biodegradation in the Porewater Chemistry (PC) experiment at the Mont Terri Rock Laboratory. Simulations show that the most important chemical processes controlling the fluid composition within the borehole and the surrounding formation during the experiment are ion exchange, biodegradation and dissolution/precipitation reactions involving pyrite and carbonate minerals. In contrast, thermodynamic mineral dissolution/precipitation reactions involving alumo-silicate minerals have little impact on the fluid composition on the time-scale of the experiment. With the accurate description of the initial chemical condition in the formation in combination with kinetic formulations describing the different stages of bacterial activities, it has been possible to reproduce the evolution of important system parameters, such as the pH, redox potential, total organic C, dissolved inorganic C and SO{sub 4} concentration. Leaching of glycerol from the pH-electrode may be the primary source of organic material that initiated bacterial growth, which caused the chemical perturbation in the borehole. Results from these simulations are consistent with data from the over-coring and demonstrate that the Opalinus Clay has a high buffering capacity in terms of chemical perturbations caused by bacterial activity. This buffering capacity can be attributed to the carbonate system as well as to the reactivity of

  9. Comparison of sorption measurements on argillaceous rocks and bentonite with predictions using the SGT-E2 approach to derive sorption data bases

    Energy Technology Data Exchange (ETDEWEB)

    Bradbury, M. H.; Baeyens, B; Marques Fernandes, M.

    2014-11-15

    In Stage 1 of the Sectoral Plan for Deep Geological Repositories, four rock types have been identified as being suitable host rocks for a radioactive waste repository, namely, Opalinus Clay for a high-level (HLW) and a low- and intermediate-level (L/ILW) repository, and 'Brauner Dogger', Effingen Member and Helvetic Marls for a L/ILW repository. Sorption data bases (SDBs) for all of these host rocks are required for the provisional safety analyses, including all of the bounding porewater and mineralogical composition combinations. In addition, SDBs are needed for the rock formations lying below Opalinus Clay (lower confining units) and for the bentonite backfill in the HLW repository. A detailed procedure was developed for deriving SDBs for argillaceous rocks (and bentonite) based on sorption edge measurements on illite (and montmorillonite), the hypothesis that 2:1 clay minerals are the dominant sorbents and a series of so called conversion factors which take into account the different radionuclide speciations in the different porewaters. Since this methodology for generating SDBs is relatively new, a validation and demonstration of the robustness and reliability of the sorption values derived was required. This report describes an extensive piece of work in which blind predictions of sorption values were compared with measured ones. Sorption isotherms were measured for the following metal ions Cs(I), Co(II), Ni(II), Eu(III), Th(IV) and U(VI) in a range of realistic porewater chemistries for a range of host rock mineralogies. In the end 53 isotherm data sets were measured. For each of these isotherms a prediction was made of the sorption at trace concentrations using the SDB derivation methodology. A comparison between measured and predicted values for each case was then made. This validation study shows that the methodology used for the derivation of the sorption data bases for argillaceous rocks and bentonite produces reliable sorption values. (authors)

  10. The FP7 ULTimateCO2 project: a study of the long term fate of CO2

    Science.gov (United States)

    Audigane, Pascal; Waldmann, Svenja; Pearce, Jonathan; Dimier, Alain; Le Gallo, Yann; Frykman, Peter; Maurand, Nicolas; Gherardi, Fabrizio; Yalamas, Thierry; Cremer, Holger; Spiers, Chris; Nussbaum, Christophe

    2014-05-01

    The objectives of the European FP7 ULTimateCO2 project are to study specific processes that could influence the long-term fate of geologically stored CO2, mainly: the trapping mechanisms occurring in the storage reservoir, the influence of fluid-rock interactions on mechanical integrity of caprock and well vicinity, and also the modifications induced at the regional scale (brine displacement, fault reactivation, hydrogeology changes...). A comprehensive approach combining laboratory experiments, numerical modeling and natural analogue studies is developed to assess all the processes mentioned above. A collection of data has been generated from natural and industrial (oil industry) analogues on the fluid flow and mechanical properties, structure, and mineralogy of faults and fractures that could affect the long-term storage capacity of underground CO2 storage sites. To address geochemical trapping at reservoir scale, an experimental approach is developed using sandstone core materials in batch reactive mode with CO2 and impurities at reservoir pressure and temperature conditions. Three inter-related lines of laboratory experiments investigate the long-term evolution of the mechanical properties and sealing integrity of fractured and faulted caprocks using Opalinus clay of Mont Terri Gallery (Switzerland), an analogue for caprock well investigated in the past for nuclear waste disposal purpose. To evaluate the interactions between CO2 (and formation fluid) and the well environment (formation, cement, casing) and to assess the consequences of these interactions on the transport properties of well materials, a 1 to 1 scale experiment has been set in the Mont Terri Gallery Opalinus clay to reproduce classical well objects (cemented annulus, casing and cement plug) perforating caprock formations. An extensive program of numerical modeling is also developed to calibrate, to reproduce and to extrapolate the experimental results at longer time scales including uncertainty

  11. Applying Squeezing Technique to Clayrocks: Lessons Learned from Experiments at Mont Terri Rock Laboratory

    International Nuclear Information System (INIS)

    Fernandez, A. M.; Sanchez-Ledesma, D. M.; Tournassat, C.; Melon, A.; Gaucher, E.; Astudillo, E.; Vinsot, A.

    2013-01-01

    Knowledge of the pore water chemistry in clay rock formations plays an important role in determining radionuclide migration in the context of nuclear waste disposal. Among the different in situ and ex-situ techniques for pore water sampling in clay sediments and soils, squeezing technique dates back 115 years. Although different studies have been performed about the reliability and representativeness of squeezed pore waters, more of them were achieved on high porosity, high water content and unconsolidated clay sediments. A very few of them tackled the analysis of squeezed pore water from low-porosity, low water content and highly consolidated clay rocks. In this work, a specially designed and fabricated one-dimensional compression cell two directional fluid flow was used to extract and analyse the pore water composition of Opalinus Clay core samples from Mont Terri (Switzerland). The reproducibility of the technique is good and no ionic ultrafiltration, chemical fractionation or anion exclusion was found in the range of pressures analysed: 70-200 MPa. Pore waters extracted in this range of pressures do not decrease in concentration, which would indicate a dilution of water by mixing of the free pore water and the outer layers of double layer water (Donnan water). A threshold (safety) squeezing pressure of 175 MPa was established for avoiding membrane effects (ion filtering, anion exclusion, etc.) from clay particles induced by increasing pressures. Besides, the pore waters extracted at these pressures are representative of the Opalinus Clay formation from a direct comparison against in situ collected borehole waters. (Author)

  12. Applying Squeezing Technique to Clayrocks: Lessons Learned from Experiments at Mont Terri Rock Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez, A. M.; Sanchez-Ledesma, D. M.; Tournassat, C.; Melon, A.; Gaucher, E.; Astudillo, E.; Vinsot, A.

    2013-07-01

    Knowledge of the pore water chemistry in clay rock formations plays an important role in determining radionuclide migration in the context of nuclear waste disposal. Among the different in situ and ex-situ techniques for pore water sampling in clay sediments and soils, squeezing technique dates back 115 years. Although different studies have been performed about the reliability and representativeness of squeezed pore waters, more of them were achieved on high porosity, high water content and unconsolidated clay sediments. A very few of them tackled the analysis of squeezed pore water from low-porosity, low water content and highly consolidated clay rocks. In this work, a specially designed and fabricated one-dimensional compression cell two directional fluid flow was used to extract and analyse the pore water composition of Opalinus Clay core samples from Mont Terri (Switzerland). The reproducibility of the technique is good and no ionic ultrafiltration, chemical fractionation or anion exclusion was found in the range of pressures analysed: 70-200 MPa. Pore waters extracted in this range of pressures do not decrease in concentration, which would indicate a dilution of water by mixing of the free pore water and the outer layers of double layer water (Donnan water). A threshold (safety) squeezing pressure of 175 MPa was established for avoiding membrane effects (ion filtering, anion exclusion, etc.) from clay particles induced by increasing pressures. Besides, the pore waters extracted at these pressures are representative of the Opalinus Clay formation from a direct comparison against in situ collected borehole waters. (Author)

  13. Siting regions for deep geological repositories. Why just here?; Standortgebiete fuer geologische Tiefenlager. Warum gerade hier?

    Energy Technology Data Exchange (ETDEWEB)

    Rieser, A

    2009-09-15

    This report helps to the popularization of the Nagra works accomplished for the management and disposal of the radioactive wastes in Switzerland. The programme for management and disposal of the radioactive wastes are extensively determined by regulations. Protection of mankind and environment is the primary objective. The basic storage process is considered as having been solved. The question addressed in the report is where the facility has to be built; the site selection procedure includes five steps: 1) according to their type the wastes have to be allocated to two different repositories: for low- and intermediate-level wastes (L/ILW), and for high-level and alpha-toxic wastes (HLW); 2) the safety concept for both repositories and the requirements on the geology have to be determined; 3) large suitable geological-tectonic zones must be found where repositories could be built; 4) in these geological zones a suitable host rock has to be identified; 5) the most important spatial geological conditions of the host rock (minimum depth with respect to surface erosion, maximum depth in terms of engineering requirements, lateral extent) have to be identified. Based on these criteria, three suitable siting regions for a HLW repository were found in the North of Switzerland. The preferred host rock is Opalinus clay because of its very low permeability; it is therefore an excellent barrier against nuclide transport. In the three proposed siting regions, Opalinus clay is present in sufficient volumes at a suitable depth. For a L/ILW repository six different possible siting regions were identified, five in Northern Switzerland and one in Central Switzerland. In the three siting regions found for a possible HLW repository, it would also be possible to built a combined repository for both HLW and L/ILW wastes.

  14. Siting regions for deep geological repositories. Why just here?

    International Nuclear Information System (INIS)

    Rieser, A.

    2009-09-01

    This report helps to the popularization of the Nagra works accomplished for the management and disposal of the radioactive wastes in Switzerland. The programme for management and disposal of the radioactive wastes are extensively determined by regulations. Protection of mankind and environment is the primary objective. The basic storage process is considered as having been solved. The question addressed in the report is where the facility has to be built; the site selection procedure includes five steps: 1) according to their type the wastes have to be allocated to two different repositories: for low- and intermediate-level wastes (L/ILW), and for high-level and alpha-toxic wastes (HLW); 2) the safety concept for both repositories and the requirements on the geol