WorldWideScience

Sample records for european eel anguilla

  1. Tagging the European eel Anguilla anguilla (L.) with coded wire tags

    DEFF Research Database (Denmark)

    Thomassen, S.; Pedersen, Michael Ingemann; Holdensgaard, G.

    2000-01-01

    The coded wire tag (CWT) system was examined as a possible tool for tagging European eels (Anguilla anguilla). Two size groups of eels (3.8 and 10.2 g) were tagged with CWTs in the dorsal musculature, Tag loss 28 days after tagging was 3.1% for the small and 0.7% for the large groups of eels...

  2. Simulated migration of European eel (Anguilla anguilla, Linnaeus 1758)

    NARCIS (Netherlands)

    Ginneken, van V.J.T.

    2006-01-01

    The European eel ( Anguillaanguilla L.) is a catadromic fish species with its spawning grounds thousands of kilometers away in the ocean, possibly theSargasso Sea. The objective of this study was to elucidate this oceanic phase of migration

  3. Modelling the recruitment of European eel (Anguilla anguilla) throughout its European range

    DEFF Research Database (Denmark)

    Bornarel, Virginie; Lambert, Patrick; Briand, Cédric

    2018-01-01

    phase remains difficult given its widespread distribution among heterogeneous and separate river catchments. Hence, it is currently considered by the International Council for the Exploration of the Sea (ICES) more feasible to use glass eel recruitment data to assess the status of the overall population......European eel (Anguilla anguilla) recruitment has been declining at least since the early 1980s at the scale of its distribution area. Since the population is panmictic, its stock assessment should be carried out on a range-wide basis. However, assessing the overall stock during the continental....... In this study, we used Glass Eel Recruitment Estimation Model (GEREM) to estimate annual recruitment (i) at the river catchment level, a scale for which data are available, (ii) at an intermediate scale (6 European regions), and (iii) at a larger scale (Europe). This study provides an estimate of the glass eel...

  4. PAH Metabolites in Bile of European Eel (Anguilla anguilla) from Morocco.

    Science.gov (United States)

    Wariaghli, Fatima; Kammann, Ulrike; Hanel, Reinhold; Yahyaoui, Ahmed

    2015-12-01

    Environmental pollution of fish with organic contaminants is a topic of rising attention in Morocco. Polycyclic aromatic hydrocarbons (PAH) are prominent organic contaminants which are rapidly metabolized in fish. Their metabolites are accumulated in the bile fluid and can be used to assess PAH exposure. The two PAH metabolites 1-hydroxypyrene and 1-hydroxyphenanthrene were quantified in European eels (Anguilla anguilla) from two Moroccan river systems by high-performance liquid chromatography with fluorescence detection. Mean values ranged from 52 to 210 ng/mL 1-hydroxypyrene and from 61 to 73 ng/mL 1-hydroxyphenanthrene. The overall concentrations of PAH metabolites in eel from Morocco appeared moderate compared to eel from European rivers and coastal sites. The present study provides first information on concentrations of PAH metabolites in fish from Morocco.

  5. Heading south or north: novel insights on European silver eel Anguilla anguilla migration in the North Sea

    NARCIS (Netherlands)

    Huisman, Jeroen; Verhelst, Pieterjan; Verhelst, Pieterjan; Deneudt, K.; Goethals, Peter; Moens, Tom; Nagelkerke, Leopold A.J.; Nolting, Carsten; Reubens, Jan; Schollema, Peter Paul; Winter, Hendrik V.; Mouton, Ans

    2016-01-01

    The European eel Anguilla anguilla L. is a critically endangered fish species that migrates from coastal and freshwater habitats to the Sargasso Sea to spawn. However, the exact migration routes and destination of European eel are still unknown. We are the first to observe southward migrating

  6. Ichthyodinium identified in the eggs of European eel (Anguilla anguilla) spawned in captivity

    DEFF Research Database (Denmark)

    Sørensen, Sune Riis; Tomkiewicz, Jonna; Skovgaard, A.

    2014-01-01

    A presumed parasitic protozoan was found in the eggs of European eel obtained from an experiment on captive breeding of eel, Anguilla anguilla, based on silver eels from a freshwater lake in the northern part of Denmark. Gross morphology of the organism was comparable to that of early stages...... of Ichthyodinium, a syndinian dinoflagellate parasite found in pelagic eggs of various marine fish species. Sequences of genes coding for small subunit ribosomal RNA confirmed that the organism was an Ichthyodinium species, and molecular phylogenetic analysis demonstrated the presence of two Ichthyodinium...

  7. The European Eel Anguilla anguilla (Pisces, Anguillidae. Native or Alien in the Black Sea?

    Directory of Open Access Journals (Sweden)

    Apostolos I. Apostolou

    2013-12-01

    Full Text Available In 2006 the Scientific, Technical and Economic Committee for Fisheries (STEFC of EU suggested the Black Sea region should be excluded from the list of natural areas, where the European eel (Anguilla anguilla is distributed. The basic conception of this idea was that the eels caught in the Black Sea region represent escaped specimens from fish farming in some Danubian countries. This article illustrates an effort to be given an indirect answer on the question if Black Sea is the end of natural distribution of European eel. The species is present but never been abundant in the region and do not represent an object of commercial fishing.

  8. Tolerance of acute hypercapnic acidosis by the European eel ( Anguilla anguilla)

    DEFF Research Database (Denmark)

    McKenzie, D J; Taylor, E W; Dalla Valle, A Z

    2002-01-01

    European eels ( Anguilla anguilla) were exposed sequentially to partial pressures of CO(2) in the water ( PwCO(2)) of 5, 10, 20, 40, 60 then 80 mm Hg (equivalent to 0.66-10.5 kPa), for 30 min at each level. This caused a profound drop in arterial plasma pH, from 7.9 to below 7.2, an increase in a...

  9. Evaluation of methods to determine sperm density for the european eel, anguilla anguilla

    DEFF Research Database (Denmark)

    Sørensen, Sune Riis; Gallego, V.; Pérez, L.

    2013-01-01

    , computer-assisted sperm analysis (CASA) and flow cytometry (FCM), using Neubauer Improved haemocytometer as benchmark. Initially, relationships between spermatocrit, haemocytometer counts and sperm motility were analysed, as well as the effect of sperm dilution on haemocytometer counts. Furthermore......, accuracy and precision of spermatocrit, applying a range of G-forces, were tested and the best G-force used in method comparisons. We found no effect of dilution on haemocytometer sperm density estimates, whereas motility associated positively with haemocytometer counts, but not with spermatocrit. Results......European eel, Anguilla anguilla, is a target species for future captive breeding, yet best methodology to estimate sperm density for application in in vitro fertilization is not established. Thus, our objectives were to evaluate methods to estimate European eel sperm density including spermatocrit...

  10. Reproductive potential of silver European eels (Anguilla anguilla migrating from Vistonis Lake (Northern Aegean Sea, Greece

    Directory of Open Access Journals (Sweden)

    R. MACNAMARA

    2014-06-01

    Full Text Available The European eel (Anguilla anguilla, once abundant throughout much of Europe and North Africa, has recently been classified as critically endangered. Information on its biology from the eastern Mediterranean is lacking, especially in relation to spawner quality. Therefore, silver eels were sampled during their seaward spawning migration from Vistonis Lake in Greece. Characteristics linked to reproductive output and success (i.e. body size and condition, sex ratio, silvering, Anguillicola crassus infection, fecundity and oocyte diameter were examined. The lake produced large (687–1138 mm, exclusively female silver eels, 61.7% of which were infected by A. crassus. Silver eel fecundity, the first estimates from the southern part of the species range, was positively related to body length (R2 = 0.693; P < 0.001 and body weight (R2 = 0.731; P < 0.001. Fecundity did not differ between A. crassus infected and uninfected silver eels, but Greek silver eels were significantly more fecund than those in north-west Europe. The reproductive potential of Vistonis Lake silver eels and their contribution to the A. anguilla spawning stock is discussed.

  11. Recovery from transportation by road of farmed European eel (Anguilla anguilla)

    NARCIS (Netherlands)

    Boerrigter, J.G.J.; Manuel, R.; Bos, van den R.; Roques, J.A.C.; Spanings, T.; Flik, G.; Vis, van de J.W.

    2015-01-01

    The objective of this study was to assess the effects of transportation of marketable eel (0.15 kg) in the Netherlands with respect to welfare. Eels (Anguilla anguilla) were obtained from a commercial farm and acclimatized for 7 weeks at the laboratory. Fish were transported according to regular

  12. Development of a broodstock diet to improve developmental competence of embryos in European eel, Anguilla anguilla

    NARCIS (Netherlands)

    Støttrup, J.G.; Tomkiewicz, J.; Jacobsen, C.; Heinsbroek, L.T.N.

    2016-01-01

    We examined the effect of dietary arachidonic acid (ARA) and eicosapentaenoic acid (EPA) on the production of embryos and hatched larvae in the European eel, Anguilla anguilla. Two diets with high and intermediate levels of ARA and low and intermediate levels of EPA (Feed 1: ARA 1.9%, EPA 4.2%;

  13. Reflex bradycardia does not influence oxygen consumption during hypoxia in the European eel (Anguilla anguilla)

    DEFF Research Database (Denmark)

    Iversen, Nina Kerting; McKenzie, David; Malte, H.

    2010-01-01

    the bradycardia on oxygen consumption (MO2), standard metabolic rate (SMR) and the critical oxygen partial pressure for regulation of SMR in hypoxia (Pcrit) in European eels Anguilla anguilla (mean ± SEM mass 528 ± 36 g; n = 14). Eels were instrumented with a Transonic flow probe around the ventral aorta......Most teleost fish reduce heart rate when exposed to acute hypoxia. This hypoxic bradycardia has been characterised for many fish species, but it remains uncertain whether this reflex contributes to the maintenance of oxygen uptake in hypoxia. Here we describe the effects of inhibiting...

  14. Movement patterns of seaward migrating European eel (Anguilla anguilla) at a complex of riverine barriers: implications for conservation

    DEFF Research Database (Denmark)

    Piper, Adam T.; Svendsen, Jon Christian; Wright, Rosalind M.

    2017-01-01

    , this is currently lacking for many species. Employing high-resolution positioning telemetry, this study examined movements of downstream migrating adult European eel, Anguilla anguilla, as they encountered a complex of water control structures in one location on the River Stour, southern England. The distribution...

  15. Anguillicola crassus (Nematoda, Dracunculoidea) infections of European eel (Anguila anguilla) in the Netherlands : epidemiology, pathogenensis and pathobiology

    NARCIS (Netherlands)

    Haenen, O.L.M.

    1995-01-01


    In the 1980s an eel parasitic nematode, Anguillicola crassus (Nematoda, Dracunculoidea), which infects the swimbladder of European eels ( Anguilla anguilla ) and other freshwater fish species, was introduced into The Netherlands. This thesis

  16. A physiologically based toxicokinetic (PBTK) model for moderately hydrophobic organic chemicals in the European eel (Anguilla anguilla)

    International Nuclear Information System (INIS)

    Brinkmann, Markus; Freese, Marko; Pohlmann, Jan-Dag; Kammann, Ulrike; Preuss, Thomas G.; Buchinger, Sebastian; Reifferscheid, Georg; Beiermeister, Anne; Hanel, Reinhold; Hollert, Henner

    2015-01-01

    The European eel (Anguilla anguilla) is a facultatively catadromous fish species with a complex life cycle. Its current population status is alarming: recruitment has decreased drastically since the 1980s and its stock is still considered to be outside safe biological limits. Although there is no consensus on the reasons for this situation, it is currently thought to have resulted from a combination of different stressors, including anthropogenic contaminants. To deepen our understanding of the processes leading to the accumulation of lipophilic organic contaminants in yellow eels (i.e. the feeding, continental growth stage), we developed a physiologically based toxicokinetic model using our own data and values from the literature. Such models can predict the uptake and distribution of water-borne organic chemicals in the whole fish and in different tissues at any time during exposure. The predictive power of the model was tested against experimental data for six chemicals with n-octanol-water partitioning coefficient (log K ow ) values ranging from 2.13–4.29. Model performance was excellent, with a root mean squared error of 0.28 log units. This model has the potential to help identify suitable habitats for restocking under eel management plans. - Highlights: • A PBTK model was developed for European eel (Anguilla anguilla). • Own experimental data and data from the literature were used for parameterization. • The predictive power of the model was excellent, with RMSE of 0.28 log units. • The developed model can be amended with sub-models for dietary and dermal exposure

  17. A physiologically based toxicokinetic (PBTK) model for moderately hydrophobic organic chemicals in the European eel (Anguilla anguilla)

    Energy Technology Data Exchange (ETDEWEB)

    Brinkmann, Markus [Department of Ecosystem Analysis, Institute for Environmental Research, ABBt — Aachen Biology and Biotechnology, RWTH Aachen University, Aachen (Germany); Freese, Marko; Pohlmann, Jan-Dag; Kammann, Ulrike [Thünen Institute of Fisheries Ecology, Hamburg (Germany); Preuss, Thomas G. [Environmental Biology and Chemodynamics, Institute for Environmental Research, ABBt — Aachen Biology and Biotechnology, RWTH Aachen University, Aachen (Germany); Buchinger, Sebastian; Reifferscheid, Georg [Federal Institute of Hydrology (BFG), Department G3: Biochemistry, Ecotoxicology, Koblenz (Germany); Beiermeister, Anne; Hanel, Reinhold [Thünen Institute of Fisheries Ecology, Hamburg (Germany); Hollert, Henner, E-mail: Henner.hollert@bio5.rwth-aachen.de [Department of Ecosystem Analysis, Institute for Environmental Research, ABBt — Aachen Biology and Biotechnology, RWTH Aachen University, Aachen (Germany); State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing (China); College of Resources and Environmental Science, Chongqing University, Chongqing (China); Key Laboratory of Yangtze Water Environment, Ministry of Education, Tongji University, Shanghai 200092 (China)

    2015-12-01

    The European eel (Anguilla anguilla) is a facultatively catadromous fish species with a complex life cycle. Its current population status is alarming: recruitment has decreased drastically since the 1980s and its stock is still considered to be outside safe biological limits. Although there is no consensus on the reasons for this situation, it is currently thought to have resulted from a combination of different stressors, including anthropogenic contaminants. To deepen our understanding of the processes leading to the accumulation of lipophilic organic contaminants in yellow eels (i.e. the feeding, continental growth stage), we developed a physiologically based toxicokinetic model using our own data and values from the literature. Such models can predict the uptake and distribution of water-borne organic chemicals in the whole fish and in different tissues at any time during exposure. The predictive power of the model was tested against experimental data for six chemicals with n-octanol-water partitioning coefficient (log K{sub ow}) values ranging from 2.13–4.29. Model performance was excellent, with a root mean squared error of 0.28 log units. This model has the potential to help identify suitable habitats for restocking under eel management plans. - Highlights: • A PBTK model was developed for European eel (Anguilla anguilla). • Own experimental data and data from the literature were used for parameterization. • The predictive power of the model was excellent, with RMSE of 0.28 log units. • The developed model can be amended with sub-models for dietary and dermal exposure.

  18. Persistence of herpesvirus of eel (Herpesvirus anguillae) in farmed European ell (Anguilla anguilla L.)

    NARCIS (Netherlands)

    Nieuwstadt, van A.P.; Dijkstra, S.G.; Haenen, O.L.M.

    2001-01-01

    Herpesvirus of eel Herpesvirus anguillae (HVA) was isolated repeatedly from farmed eel of an outwardly healthy stock, but virus isolation was much greater in an experimental group of fish that were injected with dexamethasone. The results suggest that HVA can establish a latent infection in eel.

  19. Cardio-respiratory Physiology of the European Eel (em>Agunilla anguilla)em> in Extreme Environments

    DEFF Research Database (Denmark)

    Methling, Caroline

    The main objective of this PhD thesis was to study the cardio-respiratory capabilities of the European eel (Anguilla anguilla) under extreme conditions. Three environmental conditions were studied i.e. temperature, dissolved oxygen and carbon dioxide, while a fourth condition was physiological an......), body wave speed (v) and Strouhal number (St). The results demonstrate that energy expenditure, swimming performance and efficiency all are significantly affected in migrating eels fitted with external tags....

  20. Effects of dietary fatty acid composition on metabolic rate and responses to hypoxia in the European eel (Anguilla anguilla)

    DEFF Research Database (Denmark)

    McKenzie, D.J.; Piraccini, G.; Piccolella, M.

    2000-01-01

    European eels (Anguilla anguilla, L.) were fed on a commercial diet supplemented either with 15% by dry feed weight of menhaden oil (MO), an oil rich in highly unsaturated fatty acids of the n-3 series (n-3 HUFA), or with 15% by dry feed weight of coconut oil (CO), an oil composed primarily...... of saturated fatty acids (SFA). Following 90 days of feeding, the mean final masses of eels fed the two different oil supplements were similar, and higher than the mean final mass of a group fed the commercial diet alone. The diets created two distinct phenotypes of eels, distinguished by the fatty acid (FA...

  1. Switch in rod opsin gene expression in the European eel, Anguilla anguilla (L.).

    Science.gov (United States)

    Hope, A J; Partridge, J C; Hayes, P K

    1998-01-01

    The rod photoreceptors of the European eel, Anguilla anguilla (L.), alter their wavelength of maximum sensitivity (lambda max) from c.a. 523 nm to c.a. 482 nm at maturation, a switch involving the synthesis of a new visual pigment protein (opsin) that is inserted into the outer segments of existing rods. We artificially induced the switch in rod opsin production by the administration of hormones, and monitored the switch at the level of mRNA accumulation using radiolabelled oligonuleotides that hybridized differently to the two forms of eel rod opsin. The production of the deep-sea form of rod opsin was detected 6 h after the first hormone injection, and the switch in rod opsin expression was complete within four weeks, at which time only the mRNA for the deep-sea opsin was detectable in the retinal cells. It is suggested that this system could be used as a tractable model for studying the regulatory control of opsin gene expression. PMID:9633112

  2. Kinetics of radiolabelled silver uptake and depuration in the gills of rainbow trout (Oncorhynchus mykiss) and European eel (Anguilla anguilla)

    DEFF Research Database (Denmark)

    Wood, C.M.; Grosell, M.; Hogstrand, C.

    2002-01-01

    We examined the influence of speciation on the kinetics of silver uptake and deputation in the gills of two freshwater fish, the rainbow trout (Oncorhynchus mykiss) which has high branchial Na+ and Cl- uptake rates and is relatively sensitive to silver, and the European eel (Anguilla anguilla...... labile than from Ag+ exposures, with 1.6-1.8-fold greater loss rates during the fast phases in both species. Differences in branchial silver uptake between eel and trout correlate well with differences in acute toxicity, but are not as large as differences in ion uptake rates. The complex time...

  3. Impact of the North Atlantic Oscillation on the trans-Atlantic migrations of the European eel (Anguilla anguilla)

    Science.gov (United States)

    Kettle, A. James; Bakker, Dorothee C. E.; Haines, Keith

    2008-09-01

    Glass eel catches and FAO (Food and Agricultural Organization) landings of the European freshwater eel (Anguilla anguilla) show a decrease over the past 20 years. The long-term trends in the time series mask an interannual fluctuation, which becomes apparent on the application of a high-pass filter and autocorrelation analysis. Both the FAO landings and the glass eel catches show interannual fluctuations with a repeat period of 6-8 years, similar to the period of the North Atlantic Oscillation (NAO). Most glass eel catch monitoring stations are in phase. The glass eel catches show a significant negative correlation with the NAO lagged by 0-2 years, consistent with the hypothesis that the positive NAO phase has an adverse impact on the larval survival in and migration from the Sargasso Sea spawning location, one year prior to the arrival of the glass eels in Europe and North Africa. The FAO landings can be divided into two groups of different phase that have an approximate correspondence to the NAO dipole in winter rainfall in Europe and North Africa. One group (P) comprises Denmark, Ireland, Morocco, Netherlands, Norway, Sweden, Tunisia, and the United Kingdom, and the other group (N) comprises France, Germany, Italy, Poland, Portugal, Spain, and Turkey. At least for the interannual fluctuations, the success of the glass eel fishery (and eel recruitment) may be coupled with the number of migrating silver eels from the N group of countries and uncoupled with the P group of countries.

  4. Phthalate metabolites in the European eel (Anguilla anguilla) from Mediterranean coastal lagoons.

    Science.gov (United States)

    Fourgous, C; Chevreuil, M; Alliot, F; Amilhat, E; Faliex, E; Paris-Palacios, S; Teil, M J; Goutte, A

    2016-11-01

    The levels and fate of phthalate metabolites have been poorly evaluated in fish, despite their potential ecotoxicological impacts. The present study aims to characterize the levels of phthalate metabolites in muscle tissue of yellow eels (Anguilla anguilla) from two coastal Mediterranean lagoons, during three sampling periods. Nine phthalate metabolites were detected in >70% of the samples. Slightly higher levels of phthalate metabolites were detected in March and June compared to October, suggesting possible seasonal variations in environmental release and/or phthalate metabolization process by eels. The large sample size (N=117) made it possible to explore correlations between phthalate metabolites' levels and individual parameters, such as body length, age, body condition and hepatic histo-pathologies. Body length and estimated age poorly correlated with phthalate metabolites, suggesting that eels did not accumulate phthalates during growth, contrary to persistent compounds. Eels presented different grades of hepatic fibrosis and lipidosis. A negative correlation was found between the severity of these pathologies in the liver and the sum of phthalate metabolites levels, supporting the hypothesis that eels with damaged liver are less able to metabolize xenobiotics. Copyright © 2016 Elsevier B.V. All rights reserved.

  5. Evolution of Microsatellite Loci of Tropical and Temperate Anguilla Eels

    Directory of Open Access Journals (Sweden)

    Mei-Chen Tseng

    2012-04-01

    Full Text Available Anguilla eels are divided into temperate and tropical eels, based on their major distributions. The present study collected two temperate eels, Anguilla japonica and Anguilla anguilla, and two tropical eels, Anguilla marmorata and Anguilla bicolor pacifica, to examine two questions: do temperate and tropical Anguilla eels have different genetic polymorphic patterns?; and do temperate Anguilla japonica and Anguilla anguilla have a closer relationship to each other than to tropical eels? In total, 274 sequences were cloned and sequenced from six conserved microsatellite loci to examine polymorphic patterns of these four catadromous eels. Different mutational events, including substitutions, and repeat-unit deletions and insertions, appeared in major regions, while different point mutations were observed in flanking regions. The results implied that parallel patterns of microsatellite sequences occurred within both tropical and temperate freshwater eels. Consensus flanking sequences of six homologous loci from each of the four species were constructed. Genetic distances ranged from 0.044 (Anguilla bicolor pacifica vs. Anguilla marmorata to 0.061 (Anguilla marmorata vs. Anguilla anguilla. The tree topology suggests the hypothesis of Anguilla japonica and Anguilla anguilla being a sister group must be rejected.

  6. Complete genomic sequence and taxonomic position of Eel virus European X (EVEX), a rhabdovirus of European eel

    NARCIS (Netherlands)

    Galinier, R.; Beurden, van S.J.; Amilhat, E.; Castric, J.; Schoehn, G.; Verneau, O.; Fazio, G.; Allienne, J.F.; Engelsma, M.Y.; Sasal, P.; Faliex, E.

    2012-01-01

    Eel virus European X (EVEX) was first isolated from diseased European eel Anguilla anguilla in Japan at the end of seventies. The virus was tentatively classified into the Rhabdoviridae family on the basis of morphology and serological cross reactivity. This family of viruses is organized into six

  7. Speciation and demographic history of Atlantic eels (Anguilla anguilla and A. rostrata) revealed by mitogenome sequencing

    DEFF Research Database (Denmark)

    Jacobsen, M.W.; Pujolar, J.M.; Gilbert, M.T.P.

    2014-01-01

    Processes leading to speciation in oceanic environments without obvious physical barriers remain poorly known. European and American eel (Anguilla anguilla and A. rostrata) spawn in partial sympatry in the Sargasso Sea. Larvae are advected by the Gulf Stream and other currents towards the Europea...

  8. Addressing the impact of mercury estuarine contamination in the European eel (Anguilla anguilla L., 1758) - An early diagnosis in glass eel stage based on erythrocytic nuclear morphology.

    Science.gov (United States)

    Castro, D; Mieiro, C L; Coelho, J P; Guilherme, S; Marques, A; Santos, M A; Duarte, A C; Pereira, E; Pacheco, M

    2018-02-01

    The decline of the European eel (Anguilla anguilla L., 1758) population throughout Europe has been partially attributed to pollution. As glass eel estuarine migration may represent a considerable threat, the impact of mercury (Hg) contamination at this stage was evaluated through an in situ experiment (7days). Total Hg (tHg) bioaccumulation was evaluated concomitantly with erythrocytic nuclear morphology alterations: erythrocytic nuclear abnormalities assay (ENA), frequency of immature erythrocytes (IE) and the erythrocytic maturity index (EMI). The ENA results suggested a genotoxic pressure at the most contaminated sites, in line with the tHg increase. The EMI data, together with IE frequency, showed that fish exposed to high levels of Hg exhibited alterations of haematological dynamics, translated into an erythropoiesis increment. Despite the presence of these compensatory mechanisms, the present findings suggest a harmful impact of Hg on genome integrity at this early development stage, potentially affecting eels' condition and ultimately the population sustainability. Copyright © 2017. Published by Elsevier Ltd.

  9. Gemfibrozil modulates cytochrome P450 and peroxisome proliferation-inducible enzymes in the liver of the yellow European eel (Anguilla anguilla).

    Science.gov (United States)

    Lyssimachou, Angeliki; Thibaut, Rémi; Gisbert, Enric; Porte, Cinta

    2014-01-01

    The human lipid regulator gemfibrozil (GEM) has been shown to induce peroxisome proliferation in rodents leading to hepatocarcinogenesis. Since GEM is found at biological active concentrations in the aquatic environment, the present study investigates the effects of this drug on the yellow European eel (Anguilla anguilla). Eels were injected with different concentrations of GEM (0.1 to 200 μg/g) and sampled 24- and 96-h post-injection. GEM was shown to inhibit CYP1A, CYP3A and CYP2K-like catalytic activities 24-h post-injection, but at 96-h post-injection, only CYP1A was significantly altered in fish injected with the highest GEM dose. On the contrary, GEM had little effect on the phase II enzymes examined (UDP-glucuronyltransferase and glutathione-S-transferase). Peroxisome proliferation inducible enzymes (liver peroxisomal acyl-CoA oxidase and catalase) were very weakly induced. No evidence of a significant effect on the endocrine system of eels was observed in terms of plasmatic steroid levels or testosterone esterification in the liver.

  10. A preliminary observation on the pond culture of European eel, Anguilla anguilla (Linnaeus, 1758) in Egypt: recommendations for future studies.

    Science.gov (United States)

    El-Shebly, Abdalla A; El-kady, Mohamed A H; Hossain, M Yeamin

    2007-04-01

    An experiment was conducted to assess the potential of the European eel, Anguilla anguilla for earthen pond aquaculture without supplementary feeding at Lake Manzala, Egypt. Juvenile A. anguilla of mean length 11.7 cm and 2.4 g weight were stocked in earthen ponds measuring 3 feddans (about 12,600 m2) and 1 m deep. Stocking was done in May 2003 at a rate of 5000 fish feddan(-1) in a polyculture system including tilapia and mullets and fed mainly on natural occurring prey (natural spawned tilapia) and small shrimp. The eels were culture for a period of 2 years, May 2003 to April 2005. Sampling for growth and survival were evaluated yearly. At the end of the culture period, the gross weight of the harvested eels was measured and the net pond production calculated by the difference between weight stocked and weight harvested. Temperature varied from 11.5 to 28.2 degrees C and 12.2 to 29.3 degrees C; P(H), 7.3 to 8.9 and 7.5 to 8.8; Dissolved Oxygen (DO), 5.2 to 9.8 mg L(-1) and 4.1 to 8.3 mg L(-1); and Salinity, 2.5 to 5.5 psu and 3.0 to 6.8 psu for first year and second year, respectively. At the end of the culture period, A. anguilla attained average weight of 121.4 g fish(-1) at the end of the first year and a weight range of 152.5 to 430 g fish(-1) with an average of 280.36 g fish(-1) at the end of the second year. Survival rate ranged from 91% during the first year to 100% during the second year. Net eel production was 540.18 kg feddan(-1) at the end of the first year and 723.36 kg feddan(-1) at the end of the second year. Daily increments in weight per fish were 0.33 and 0.44 for first and second year, respectively. This experiment demonstrated the possibility of cultivation of eels as well as the higher growth rate in earthen ponds. The aquaculture strategy of eel with high stocking densities through low cost artificial feeds are recommended in future studies.

  11. Gelatinous plankton is central to the diet of European eel (Anguilla anguilla) larvae in the Sargasso Sea

    DEFF Research Database (Denmark)

    Ayala, Daniel Jiro; Munk, Peter; Lundgreen, Regitze B. C.

    2018-01-01

    endangered species. Next-generation 18S rRNA gene sequencing data of Sargasso Sea eel larvae gut contents and marine snow aggregates was compared with a reference plankton database to assess the trophic relations of eel larvae. Gut contents of A. anguilla larvae were not well explained by the eukaryotic...

  12. Microbial interference with hatch and survival of European eel larvae

    DEFF Research Database (Denmark)

    Sørensen, Sune Riis; Lauesen; Tomkiewicz, Jonna

    Recent research has significantly improved our knowledge and capabilities in the field of in vitro production of yolk sac larvae from European eel (Anguilla anguilla). Female broodstock European eels are matured by weekly administration of pituitary extract and male eels with hCG (human chorionic...... larviculture should not only focus on optimizing physical incubation conditions, but certainly also on the control over microbial interference....

  13. Development of a broodstock diet to improve developmental competence of embryos in European eel, Anguilla anguilla

    DEFF Research Database (Denmark)

    Støttrup, Josianne Gatt; Tomkiewicz, Jonna; Jacobsen, Charlotte

    2016-01-01

    We examined the effect of dietary arachidonic acid (ARA) and eicosapentaenoic acid (EPA) on the production of embryos and hatched larvae in the European eel, Anguilla anguilla. Two diets with high and intermediate levels of ARA and low and intermediate levels of EPA (Feed 1: ARA 1.9%, EPA 4.......2%; Feed 2: ARA 1.2%, EPA 5.1% of total fatty acids) were tested against a commercial diet (DE: ARA: 0.5%, EPA: 8.2% of total fatty acids). After 24 weeks of feeding, ARA levels in the muscles and ovaries increased to 0.9% and 1.3% of total fatty acids, respectively, in Feed 1 and were significantly higher...... than in Feed 2 and DE. Female broodstock was not fed during hormonal treatment to induce vitellogenesis and ovulation. EPA levels in females fed the test diets decreased in the both muscle and ovary and were significantly lower in eggs from females fed Feed 1. The highest percentage of stripped females...

  14. Analyses of organochlorine pesticides residues in eels (Anguilla anguilla from Lake Garda using Gas chromatography coupled with Tandem Mass Spectrometry (GC-MS/MS.

    Directory of Open Access Journals (Sweden)

    Giuseppe Federico Labella

    2017-05-01

    Full Text Available Lake Garda is located in Insubria region, that is known for being the most populated and industrialized area of Italy (Camusso et al., 2001. Therefore, the Lake water, and also the fish species present, could be affected by environmental contamination.  European eel (Anguilla anguilla are considered as suitable matrix for biomonitoring environmental contaminants in European water (Belpaire et al., 2007, being widespread in many European waters and highly contaminated by lipophilic compounds, due to the high lipid content (up to 40% (Larsson et al., 1991. Moreover, eel is an edible species (its farming currently supplies approximately 45,000 tons/year (Nielsen et al., 2008, so it also represents a public health issue. Based on these considerations, the aim of this study was to evaluate the occurrence of fourteen organochlorine pesticides (OCs in forty-five eels (Anguilla anguilla from Lake Garda, using Accelerated Solvent Extraction (ASE procedure for the analytes extraction and Gas chromatography coupled with Tandem Mass Spectrometry (GC-MS/MS for the analysis of OCs. GC-MS/MS analysis was developed and validated according to the SANTE/11945/2015 guidelines.  Uncontaminated eel sample (previously checked for the presence of OCs and considered blank with a concentration of compounds < Limit of Detection were used for all procedure's optimization steps. For all the OCs analysed, satisfactory results were achieved. Regarding eel samples, several pesticides were detected, but DDTs (DDT and its metabolites were found with the highest prevalence (92 %. The concentration rage was from not detected (n.d. to 19000 ng g-1. Although DDTs levels in the environment are declining (Albaiges et al., 2011, they continue to bioaccumulate in tissues of human and animal and biomagnify in food chains.

  15. Behaviour of stocked and naturally recruited European eels during migration

    DEFF Research Database (Denmark)

    Westerberg, Håkan; Sjöberg, Niklas; Lagenfelt, Ingvar

    2014-01-01

    An objection to the stocking of translocated eels as a management measure for the European eel (Anguilla anguilla L.) is that these eels may lack the ability to find their way back to the spawning area in the Sargasso Sea because the translocation will confuse their imprinted navigation. We...... behaviour could be monitored by acoustic tagging, in addition to using archival and satellite tags to track the subsequent marine migration. In the second year, the eels were released on the open coast and only their marine migration was investigated. Eels were tracked more than 2000 km along a route that...

  16. Subcellular partitioning of non-essential trace metals (Ag, As, Cd, Ni, Pb, and Tl) in livers of American (Anguilla rostrata) and European (Anguilla anguilla) yellow eels

    Energy Technology Data Exchange (ETDEWEB)

    Rosabal, Maikel [Institut national de la recherche scientifique, Centre Eau Terre et Environnement (INRS–ETE), 490 de la Couronne, Québec (Québec) G1K 9A9 (Canada); Pierron, Fabien [Université de Bordeaux, UMR EPOC CNRS 5805, F-33400 Talence (France); CNRS, EPOC, UMR 5805, F-33400 Talence (France); Couture, Patrice [Institut national de la recherche scientifique, Centre Eau Terre et Environnement (INRS–ETE), 490 de la Couronne, Québec (Québec) G1K 9A9 (Canada); Baudrimont, Magalie [Université de Bordeaux, UMR EPOC CNRS 5805, F-33400 Talence (France); CNRS, EPOC, UMR 5805, F-33400 Talence (France); Hare, Landis [Institut national de la recherche scientifique, Centre Eau Terre et Environnement (INRS–ETE), 490 de la Couronne, Québec (Québec) G1K 9A9 (Canada); Campbell, Peter G.C., E-mail: peter.campbell@ete.inrs.ca [Institut national de la recherche scientifique, Centre Eau Terre et Environnement (INRS–ETE), 490 de la Couronne, Québec (Québec) G1K 9A9 (Canada)

    2015-03-15

    Highlights: • Handling of hepatic metals consistently involved cytosolic, thermostable ligands. • Granule-like fractions are also involved in the detoxification of Ni, Pb, and Tl. • Despite these sequestration mechanisms, metal detoxification is incomplete. • Along the metal gradient, concentrations increase in metal-sensitive fractions. • This increase could represent a toxicological risk for the yellow eels. - Abstract: We determined the intracellular compartmentalization of the trace metals Ag, As, Cd, Ni, Pb, and Tl in the livers of yellow eels collected from the Saint Lawrence River system in Canada (Anguilla rostrata) and in the area of the Gironde estuary in France (Anguilla anguilla). Differential centrifugation, NaOH digestion and thermal shock were used to separate eel livers into putative “sensitive” fractions (heat-denatured proteins, mitochondria and microsomes + lysosomes) and detoxified metal fractions (heat-stable peptides/proteins and granules). The cytosolic heat-stable fraction (HSP) was consistently involved in the detoxification of all trace metals. In addition, granule-like structures played a complementary role in the detoxification of Ni, Pb, and Tl in both eel species. However, these detoxification mechanisms were not completely effective because increasing trace metal concentrations in whole livers were accompanied by significant increases in the concentrations of most trace metals in “sensitive” subcellular fractions, that is, mitochondria, heat-denatured cytosolic proteins and microsomes + lysosomes. Among these “sensitive” fractions, mitochondria were the major binding sites for As, Cd, Pb, and Tl. This accumulation of non-essential metals in “sensitive” fractions likely represents a health risk for eels inhabiting the Saint Lawrence and Gironde environments.

  17. Gelatinous plankton is central to the diet of European eel (Anguilla anguilla) larvae in the Sargasso Sea

    DEFF Research Database (Denmark)

    Ayala, Daniel Jiro; Munk, Peter; Lundgreen, Regitze B. C.

    2018-01-01

    endangered species. Next-generation 18S rRNA gene sequencing data of Sargasso Sea eel larvae gut contents and marine snow aggregates was compared with a reference plankton database to assess the trophic relations of eel larvae. Gut contents of A. anguilla larvae were not well explained by the eukaryotic...... composition of marine snow aggregates; gut contents being dominated by gene sequences of Hydrozoa taxa (phylum Cnidaria), while snow aggregates were dominated by Crustacea taxa. Pronounced differences between gut contents and marine snow aggregates were also seen in the prokaryotic 16S rRNA gene composition...

  18. Anthropogenic spreading of anguillid herpesvirus 1 by stocking of infected farmed European eels, Anguilla anguilla (L.), in the Schlei fjord in northern Germany.

    Science.gov (United States)

    Kullmann, B; Adamek, M; Steinhagen, D; Thiel, R

    2017-11-01

    The Schlei fjord in northern Germany is the recipient water of a comprehensive eel, Anguilla anguilla (L.), stocking programme. Since 2015, stocked eels become alizarin red S marked, but to date no control mechanism is implemented in this stock enhancement measure to prevent anthropogenic spreading of diseases. Consequentially, it was possible that farmed stocking cohorts of 2015 and 2016 (in total ca. 1040 kg) were subsequently tested positive for anguillid herpesvirus 1 (AngHV 1). For this study, 100 eels [total length (TL) 24.3-72.9 cm, age ca. 1-6 years] were caught in 2016 and investigated with regard to AngHV 1 infection, parasite load (Anguillicoloides crassus) and body conditions. 68% of the eels were found to be virus positive while larger specimens were more often infected. In addition, a fitted generalized linear model (area under the curve = 0.741) demonstrated that an increase in individual TL is accompanied with an increased risk of clinically relevant virus loads. Anguillicoloides crassus turned out to be an important stressor for eels, because parasite and virus load revealed a significant positive correlation. The results of this study evidently show the urgent need of a disease containment strategy for eel stocking programmes. © 2017 John Wiley & Sons Ltd.

  19. The effect of metals on condition and pathologies of European eel (Anguilla anguilla): in situ and laboratory experiments.

    Science.gov (United States)

    Esteve, Consuelo; Alcaide, Elena; Ureña, Rocio

    2012-03-01

    Forty-nine wild eels (Anguilla anguilla) caught in the Albufera Lake (Spain), measuring 24.0-75.0 cm in length and 25.0-637.7 g in weight, were examined for metals (Cd, Co, Cr, Cu, Fe, Hg, Mn, Pb, Se and Zn), condition (CI and HSI indices), as well as for diseases (Anguillicola infestation; bacterial infections). Total metal load significantly increased in eel liver tissue parallel to total length and body weight (log), while silvering females (W(B) > 200 g; L ≥ 500 mm) exhibited the highest amounts of Co, Cu, Hg, Se and Zn. Diverse effects may be expected in these big eels due to long-term metal exposure. In fact, IMBI (individual mean (multi-metal) bioaccumulation index) and copper load (Ln) in particular, were significantly related with a decrease in the HSI, reflecting lower eel fitness. In addition, most silvering females (75%) showed a CI below 0.2, and this size group presented the highest prevalence of chronic diseases, at significant levels, that are non-lethal in the short term, but degenerative in the long term. Amounts of hepatic iron were not correlated with eel size; however, a significant, strong negative correlation between this metal (Ln) and HSI and CI was found for wild eels suffering from diseases of any aetiology. This also included small eels (W(B) <67 g; L < 350 mm), as this size group presented a significant prevalence of acute diseases caused by single virulent bacterial pathogens (i.e. Edwardsiella tarda and Vibrio vulnificus biotype 2). To assess the effect of metals on susceptibility to disease, yellow eels were maintained and exposed to iron, copper, and pathogens, in captivity under laboratory conditions. Co-exposure of eels to iron (9 μg of Fe/g of fish) and bacterial pathogens by intraperitoneal injection (IP), yielded a hundred-fold reduction in the LD50 of all bacteria assayed (i.e. E. tarda, V. vulnificus, and motile Aeromonas), and also the time taken to cause eel death. Short-term aqueous exposure of eels to 0.4, 0.7, 1.7 and

  20. Using interview-based recall surveys to estimate cod Gadus morhua and eel Anguilla anguilla harvest in Danish recreational fishing

    DEFF Research Database (Denmark)

    Sparrevohn, Claus Reedtz; Storr-Paulsen, Marie

    2012-01-01

    Using interview-based recall surveys to estimate cod Gadus morhua and eel Anguilla anguilla harvest in Danish recreational fishing. – ICES Journal of Marine Science, 69: 323–330.Marine recreational fishing is a popular outdoor activity in Denmark, practised by both anglers and passive gear fishers....... However, the impact on the targeted stocks is unknown, so to estimate the 2009 harvest of cod Gadus morhua and eel Anguilla anguilla, two separate interview-based surveys were initiated and carried out in 2009/2010. The first recall survey exclusively targeted fishers who had been issued......, in certain areas, the recreational harvest of cod accounted for more than 30% of the total yield. The majority (81%) of the recreational cod harvest was taken by anglers. Eels, however, are almost exclusively caught with passive gear (fykenets) and a total of 104 t year−1 was harvested, which corresponds...

  1. Estimating and mitigating post-release mortality of European eel by combining citizen science with a catch-and-release angling experiment

    NARCIS (Netherlands)

    Weltersbach, Marc Simon; Weltersbach, Marc Simon; Strehlow, Harry Vincent; Ferter, Keno; Klefoth, Thomas; Graaf, de Martin; Graaf, de Martin; Dorow, Malte

    2018-01-01

    Several anguillid eel species have experienced severe population declines over the past decades, particularly the European eel (Anguilla anguilla), which is listed as critically endangered by the International Union for Conservation of Nature. To reduce fishing mortality, many European countries

  2. Occurrence of Edwardsiella tarda in wild European eels Anguilla anguilla from Mediterranean Spain.

    Science.gov (United States)

    Alcaide, Elena; Herraiz, Sonia; Esteve, Consuelo

    2006-11-21

    Pure cultures of Edwarsiella tarda were isolated from body ulcers and internal organs of wild European eels caught in a Mediterranean freshwater coastal lagoon (Albufera Lake, Valencia, Spain) over a 1 yr period. Overall, the E. tarda isolation rate from wild eels was 9%, but this increased to 22.8% in diseased individuals. All 22 E. tarda isolates belonged to the 'wild-type' biogroup of the species and were virulent for eels (lethal dose that kills 50% of exposed individuals [LD50 dose]: 10(4.85) to 10(6.83) CFU ind.(-1)), and therefore represented the aetiological agent of the haemorrhagic disease observed in wild European eels. The E. tarda isolates and E. tarda CECT 894T type strain were biochemically and serologically related and resistant to macrolides, antifolates, and glycopeptides, but only the isolates from wild eels were resistant to clindamicyn. This study is the first description of edwardsiellosis in a wild European eel population, and alerts us to the presence of E. tarda in natural wetland environments in Mediterranean Europe.

  3. Reproduction of European eel jeopardised by high levels of dioxins and dioxin-like PCBs?

    Science.gov (United States)

    Geeraerts, C; Focant, J-F; Eppe, G; De Pauw, E; Belpaire, C

    2011-09-01

    Dioxins, furans and dioxin-like polychlorinated biphenyls (PCBs) were analysed in muscle tissue from yellow phased European eel (Anguilla anguilla) from 38 sites in Belgium. Dioxin concentrations in eel vary considerably between sampling locations, indicating that yellow eel is a good indicator of local pollution levels. Measured levels of dioxin-like PCBs are much higher than those of the dioxins and furans. In the majority of the sites, eel has levels considered to be detrimental for their reproduction. Field levels of dioxin and dioxin-like PCBs are therefore suggested as an additional causal factor contributing to the decline of the European eel. 42% of the sampling sites show especially dioxin-like PCB levels exceeding the European consumption level (with a factor 3 on average). Human consumption of eel, especially in these highly contaminated sites, seems unjustified. Copyright © 2011 Elsevier B.V. All rights reserved.

  4. Assessing pre- and post-zygotic barriers between North Atlantic eels (Anguilla anguilla and A. rostrata)

    DEFF Research Database (Denmark)

    Jacobsen, M. W.; Smedegaard, L.; Sørensen, Sune Riis

    2017-01-01

    Elucidating barriers to gene flow is important for understanding the dynamics of speciation. Here we investigate pre- and post-zygotic mechanisms acting between the two hybridizing species of Atlantic eels: Anguilla anguilla and A. rostrata. Temporally varying hybridization was examined by analyz...... in natural hybrids.Heredity advance online publication, 9 November 2016; doi:10.1038/hdy.2016.96....

  5. Angiotensin II dependent cardiac remodeling in the eel Anguilla anguilla involves the NOS/NO system

    DEFF Research Database (Denmark)

    Filice, Mariacristina; Amelio, Daniela; Garofalo, Filippo

    2017-01-01

    Angiotensin II (AngII), the principal effector of the Renin-Angiotensin System (RAS), plays an important role in controlling mammalian cardiac morpho-functional remodelling. In the eel Anguilla anguilla, one month administration of AngII improves cardiac performance and influences the expression ...

  6. Magnetic Compass Orientation in the European Eel

    OpenAIRE

    Durif, Caroline M. F.; Browman, Howard I.; Phillips, John B.; Skiftesvik, Anne Berit; V?llestad, L. Asbj?rn; Stockhausen, Hans H.

    2013-01-01

    European eel migrate from freshwater or coastal habitats throughout Europe to their spawning grounds in the Sargasso Sea. However, their route (~ 6000 km) and orientation mechanisms are unknown. Several attempts have been made to prove the existence of magnetoreception in Anguilla sp., but none of these studies have demonstrated magnetic compass orientation in earth-strength magnetic field intensities. We tested eels in four altered magnetic field conditions where magnetic North was set at ge...

  7. Modification of essential fatty acid composition in broodstock of cultured European eel Anguilla anguilla L

    DEFF Research Database (Denmark)

    Støttrup, Josianne; Jacobsen, Charlotte; Tomkiewicz, Jonna

    2013-01-01

    Farmed eels had lower levels of arachidonic acid (20:4 n-6) (ARA) and higher ratios of eicosapentaenoic acid (20:5 n-3) (EPA):ARA compared to wild European eels collected from the Baltic Sea and southern Norwegian coast. Eels fed a formulated feed (JD) with a distribution of essential fatty acids...... and docosahexaenoic acid (22:6 n-3) (DHA) had accumulated in ovarian polar lipids......Farmed eels had lower levels of arachidonic acid (20:4 n-6) (ARA) and higher ratios of eicosapentaenoic acid (20:5 n-3) (EPA):ARA compared to wild European eels collected from the Baltic Sea and southern Norwegian coast. Eels fed a formulated feed (JD) with a distribution of essential fatty acids...... (EFA) resembling wild European eel were sampled after 0, 5, 10, 14 and 44 weeks of feeding to examine changes in fatty acid composition (FAC) in ovaries, visceral fat and muscle. The results showed a slow but steady incorporation of EFA. Lipids are incorporated in the oocytes early in oogenesis...

  8. Fishery-induced selection for slow somatic growth in European eel.

    Directory of Open Access Journals (Sweden)

    Daniele Bevacqua

    Full Text Available Both theoretical and experimental studies have shown that fishing mortality can induce adaptive responses in body growth rates of fishes in the opposite direction of natural selection. We compared body growth rates in European eel (Anguilla anguilla from three Mediterranean stocks subject to different fishing pressure. Results are consistent with the hypotheses that i fast-growing individuals are more likely to survive until sexual maturity than slow-growing ones under natural conditions (no fishing and ii fishing can select for slow-growing individuals by removing fast-growing ones. Although the possibility of human-induced evolution seems remote for a panmictic species like such as the European eel, further research is desirable to assess the implications of the intensive exploitation on this critically endangered fish.

  9. Ubiquitous distribution of fluorescent protein in muscles of four species and two subspecies of eel (genus Anguilla).

    Science.gov (United States)

    Funahashi, Aki; Itakura, Takao; Hassanin Abeer, A I; Komatsu, Masaharu; Hayashi, Seiichi; Kaminishi, Yoshio

    2017-03-01

    In this study, the localization of fluorescent protein (FP) was characterized in the muscles of four species and two subspecies of eels Anguilla anguilla, A. australis, A. bicolor bicolor (b.), A. bicolor pacifica (p.) and A. mossambica in addition to the previously reported A. japonica. The open reading frame of each eel FP was 417 bp encoding 139 amino acid residues. The deduced amino acid sequences among the four species and two subspecies exhibited 91.4-100% identity, and belonged to the fatty-acid-binding protein (FABP) family. The gene structure of eel FPs in A. japonica, A. anguilla, A. australis, A. bicolor b., A. bicolor p. and A. mossambica have four exons and three introns, and were common to that of FABP family. The apo eel FPs expressed by Escherichia coli with recombinant eel FP genes were analysed for the fluorescent properties in the presence of bilirubin. The excitation and emission spectra of holo eel FPs had the maximum wavelengths of 490-496 and 527-530 nm, respectively. The holo eel FPs indicated that the fluorescent intensities were stronger in A. japonica and A. bicolor than in A. mossambica, A. australis and A. anguilla. The comparison of amino acid sequences revealed two common substitutions in A. mossambica, A. australis and A. anguilla with weak fluorescent intensity.

  10. Assessing patterns of hybridization between North Atlantic eels using diagnostic single-nucleotide polymorphisms

    DEFF Research Database (Denmark)

    Pujolar, José Martin; Jacobsen, M.W.; Als, Thomas Damm

    2014-01-01

    The two North Atlantic eel species, the European eel (Anguilla anguilla) and the American eel (Anguilla rostrata), spawn in partial sympatry in the Sargasso Sea, providing ample opportunity to interbreed. In this study, we used a RAD (Restriction site Associated DNA) sequencing approach to identify...... species-specific diagnostic single-nucleotide polymorphisms (SNPs) and design a low-density array that combined with screening of a diagnostic mitochondrial DNA marker. Eels from Iceland (N=159) and from the neighboring Faroe Islands (N=29) were genotyped, along with 94 larvae (49 European and 45 American...... eel male crosses, backcrosses were also detected, including a first-generation backcross (F1 hybrid × pure European eel) and three individuals identified as second-generation backcrosses originating from American eel × F1 hybrid backcrosses interbreeding with pure European eels. In comparison...

  11. Temperature effects on gene expression and morphological development of European eel, Anguilla anguilla larvae

    DEFF Research Database (Denmark)

    Politis, Sebastian Nikitas; Mazurais, David; Servili, Arianna

    2017-01-01

    °C as the optimal temperature for offspring of European eel. Furthermore, our results suggest that the still enigmatic early life history stages of European eel may inhabit the deeper layer of the Sargasso Sea and indicate vulnerability of this critically endangered species to increasing ocean......Temperature is important for optimization of rearing conditions in aquaculture, especially during the critical early life history stages of fish. Here, we experimentally investigated the impact of temperature (16, 18, 20, 22 and 24°C) on thermally induced phenotypic variability, from larval hatch...

  12. Tolerance of chronic hypercapnia by the European eel Anguilla anguilla

    DEFF Research Database (Denmark)

    McKenzie, D J; Piccolella, M; Dalla Valle, A Z

    2003-01-01

    European eels were exposed for 6 weeks to water CO(2) partial pressures (P(CO)(2)) from ambient (approx. 0.8 mmHg), through 15+/-1 mmHg and 30+/-1 mmHg to 45+/-1 mmHg in water with a total hardness of 240 mg l(-1) as CaCO(3), pH 8.2, at 23+/-1 degrees C. Arterial plasma P(CO)(2) equilibrated at a...

  13. Bioaccumulation of polychlorinated biphenyls in the eel (Anguilla anguilla) at the Camargue Nature Reserve - France

    International Nuclear Information System (INIS)

    Oliveira Ribeiro, C.A.; Vollaire, Y.; Coulet, E.; Roche, H.

    2008-01-01

    Fish consumption is a potential source of human exposure to pollutants. Here, we study residue levels of PCBs in the eel, Anguilla anguilla, from the Nature Camargue Reserve in southern France. Chromatographic analysis (GC-ECD) found seventy identifiable congeners, among which, 10 are considered as dioxin-like PCBs, such as the non-ortho PCB 81 and the mono-ortho chlorobiphenyls PCB105, 114, 118, 123, 156, 157, 167, 170, 180. Toxic Equivalents (TEQ, WHO 2005 TEF-Toxic Equivalent Factors) varied among sites with a maximum in eels from Mornes (29.6 pg g -1 dry weight). Indicator PCBs (28, 52, 101, 118, 138, 153 and 180) were 22% and 29% of the total PCBs in livers and muscles respectively. Greater homogeneous bioaccumulation in muscle than that in liver suggests an increase risk for humans due to fish consumption. - The reserve of Camargue - South of France is impacted by a myriad of pollutant organic persistent like PCBs

  14. Seasonal variability of metallothioneins, cytochrome P450, Bile metabolites and oxyradical metabolism in the European eel Anguilla anguilla L. (Anguillidae) and striped mullet Mugil cephalus L. (Mugilidae).

    Science.gov (United States)

    Gorbi, Stefania; Baldini, Chiara; Regoli, Francesco

    2005-07-01

    The European eel Anguilla anguilla (Anguillidae) and the striped mullet Mugil cephalus (Mugilidae) are typical inhabitants of Mediterranean brackish lagoons, and their utility as bioindicator organisms has already been suggested. The seasonal variability of several potential biomarkers was investigated during a field study carried out in the Orbetello lagoon (Tuscany, Italy). Organisms were sampled on a seasonal basis, and analyzed parameters included the levels of hepatic metallothioneins, the activity of cytochrome P450 1A (EROD), and the presence of biliary PAH metabolites. Special attention was also paid to antioxidant defenses, including catalase, glutathione peroxidases, glutathione reductase, glutathione S-transferases, and total glutathione concentration. Total Oxyradical Scavenging Capacity (TOSC-assay) was measured as an indication of the overall biological resistance to toxicity of different forms of oxyradicals (peroxynitrite, peroxyl and hydroxyl radicals). Obtained results suggest that natural variations of analyzed responses are associated with seasonality of both environmental and biological factors, mainly temperature and reproductive cycle which, however, have a different influence in these two species. Striped mullets exhibited the strongest variations in October when spawning occurs; eels are not influenced by a seasonal sexual maturation and showed more marked changes during the summer, likely related to the elevated seawater temperature and light irradiance in the lagoon. This study confirms the importance of characterizing seasonal variations and the influence of different factors on biological responses that can be used as biomarkers in monitoring programs.

  15. An otolith microchemistry study of possible relationships between the origins of leptocephali of European eels in the Sargasso Sea and the continental destinations and relative migration success of glass eels

    DEFF Research Database (Denmark)

    Martin, J.; Daverat, F.; Pécheyran, C.

    2010-01-01

    's core region of Anguilla anguilla leptocephali caught in the Sargasso Sea in 2007 with those of glass eels and elvers sampled in European estuaries during 2006, 2008 and 2009. Using laser ablation inductively coupled plasma mass spectrometry, the same annular ablation trajectory along the first feeding...

  16. Gonadal transcriptome analysis of wild contaminated female European eels during artificial gonad maturation.

    Science.gov (United States)

    Baillon, Lucie; Oses, Jennifer; Pierron, Fabien; Bureau du Colombier, Sarah; Caron, Antoine; Normandeau, Eric; Lambert, Patrick; Couture, Patrice; Labadie, Pierre; Budzinski, Hélène; Dufour, Sylvie; Bernatchez, Louis; Baudrimont, Magalie

    2015-11-01

    Since the early 1980s, the population of European eels (Anguilla anguilla) has dramatically declined. Nowadays, the European eel is listed on the red list of threatened species (IUCN Red List) and is considered as critically endangered of extinction. Pollution is one of the putative causes for the collapse of this species. Among their possible effects, contaminants gradually accumulated in eels during their somatic growth phase (yellow eel stage) would be remobilized during their reproductive migration leading to potential toxic events in gonads. The aim of this study was to investigate the effects of organic and inorganic contaminants on the gonad development of wild female silver eels. Female silver eels from two sites with differing contamination levels were artificially matured. Transcriptomic analyses by means of a 1000 candidate gene cDNA microarray were performed on gonads after 11weeks of maturation to get insight into the mechanisms of toxicity of contaminants. The transcription levels of several genes, that were associated to the gonadosomatic index (GSI), were involved in mitotic cell division but also in gametogenesis. Genes associated to contaminants were mainly involved in the mechanisms of protection against oxidative stress, in DNA repair, in the purinergic signaling pathway and in steroidogenesis, suggesting an impairment of gonad development in eels from the polluted site. This was in agreement with the fact that eels from the reference site showed a higher gonad growth in comparison to contaminated fish. Copyright © 2015 Elsevier Ltd. All rights reserved.

  17. Piscivory and trophic position of Anguilla anguilla in two lakes: importance of macrozoobenthos density

    DEFF Research Database (Denmark)

    Dorner, H.; Skov, Christian; Berg, Søren

    2009-01-01

    The feeding habits of the European eel Anguilla anguilla (> 300 mm total length, L-T) were compared in two lakes of different environmental state: Lake Gro ss er Vatersee (LGV), Germany (clear water, mesotrophic and submerged macrophytes), and Lake Vallum (LV), Denmark (turbid, eutrophic and no s...... on these results, it is concluded that piscivory among A. anguilla was generally controlled by the density of macrozoobenthos. Stable isotope analysis further indicated that A. anguilla may act as integrators between benthic and pelagic food webs when density of insect larvae is low....

  18. Age and growth of the longfin eel, Anguilla mossambica Peters ...

    African Journals Online (AJOL)

    Otoliths were successfully used for age determination and growth-rate calculation of the longfin eel, Anguilla mossambica Peters, 1852. The large opaque nucleus of the otoliths represents the leptocephalid stage and probably lasts from one and a half to two years. Thereafter, one opaque and one hyaline zone is deposited ...

  19. Anthropogenic noise compromises antipredator behaviour in European eels.

    Science.gov (United States)

    Simpson, Stephen D; Purser, Julia; Radford, Andrew N

    2015-02-01

    Increases in noise-generating human activities since the Industrial Revolution have changed the acoustic landscape of many terrestrial and aquatic ecosystems. Anthropogenic noise is now recognized as a major pollutant of international concern, and recent studies have demonstrated impacts on, for instance, hearing thresholds, communication, movement and foraging in a range of species. However, consequences for survival and reproductive success are difficult to ascertain. Using a series of laboratory-based experiments and an open-water test with the same methodology, we show that acoustic disturbance can compromise antipredator behaviour--which directly affects survival likelihood--and explore potential underlying mechanisms. Juvenile European eels (Anguilla anguilla) exposed to additional noise (playback of recordings of ships passing through harbours), rather than control conditions (playback of recordings from the same harbours without ships), performed less well in two simulated predation paradigms. Eels were 50% less likely and 25% slower to startle to an 'ambush predator' and were caught more than twice as quickly by a 'pursuit predator'. Furthermore, eels experiencing additional noise had diminished spatial performance and elevated ventilation and metabolic rates (indicators of stress) compared with control individuals. Our results suggest that acoustic disturbance could have important physiological and behavioural impacts on animals, compromising life-or-death responses. © 2014 John Wiley & Sons Ltd.

  20. Salinity reduction benefits European eel larvae: Insights at the morphological and molecular level

    DEFF Research Database (Denmark)

    Politis, Sebastian Nikitas; Mazurais, David; Servili, Arianna

    2018-01-01

    . Moreover, larvae were able to keep energy metabolism related gene expression (atp6, cox1) at stable levels, irrespective of the salinity reduction. As such, when reducing salinity, an energy surplus associated to reduced osmoregulation demands and stress (lower nkcc, aqp and hsp expression), likely......European eel (Anguilla anguilla) is a euryhaline species, that has adapted to cope with both, hyper- and hypo-osmotic environments. This study investigates the effect of salinity, from a morphological and molecular point of view on European eel larvae reared from 0 to 12 days post hatch (dph......). Offspring reared in 36 practical salinity units (psu; control), were compared with larvae reared in six scenarios, where salinity was decreased on 0 or 3 dph and in rates of 1, 2 or 4 psu/day, towards iso-osmotic conditions. Results showed that several genes relating to osmoregulation (nkcc2α, nkcc2β, aqp1...

  1. Oceanic fronts in the Sargasso Sea control the early life and drift of Atlantic eels

    DEFF Research Database (Denmark)

    Munk, Peter; Hansen, Michael Møller; Maas, Gregory E.

    2010-01-01

    Anguillid freshwater eels show remarkable life histories. In the Atlantic, the European eel (Anguilla anguilla) and American eel (Anguilla rostrata) undertake extensive migrations to spawn in the oceanic Sargasso Sea, and subsequently the offspring drift to foraging areas in Europe and North......, during a field expedition to the eel spawning sites in the Sargasso Sea, we carried out a wide range of dedicated bio-physical studies across areas of eel larval distribution. Our findings suggest a key role of oceanic frontal processes, retaining eel larvae within a zone of enhanced feeding conditions...

  2. Preslaughter electrical stunning of eels

    NARCIS (Netherlands)

    Robb, D.H.F.; Wotton, S.B.; Vis, van de J.W.

    2002-01-01

    The current procedures for slaughtering European eels (Anguilla anguilla) for food are very slow and cause suffering. Although there is little legislation for protecting the welfare of fish at slaughter, the legislation covering farmed mammals and birds at slaughter is well defined, requiring that

  3. Tidal-Flat Macrobenthos as Diets of the Japanese Eel Anguilla japonica in Western Japan, with a Note on the Occurrence of a Parasitic Nematode Heliconema anguillae in Eel Stomachs.

    Science.gov (United States)

    Kan, Kotaro; Sato, Masanori; Nagasawa, Kazuya

    2016-02-01

    Dietary items of the Japanese eel Anguilla japonica inhabiting estuaries were examined by analyses of the gut (stomach and intestine) contents in two areas in Kyushu, western Japan. In a small estuary in Kagoshima Bay, where seven eel guts were examined, almost all of the dietary organisms consisted of Hemigrapsus crabs and Hediste polychaetes, both of which commonly occurred on tidal flats of this site during our survey on the macrobenthic fauna. In another large estuary in the innermost part of the Ariake Sea, where 14 eel guts were examined, 11 macrobenthic species (nine crustaceans, a polychaete, and a gastropod) were found in the gut contents, mostly consisting of mudflat-specific species. The dietary items are almost completely different not only between the two estuaries, but also among three neighboring sites within the large estuary in the Ariake Sea. These results show that Japanese eels feed on various macrobenthic invertebrates inhabiting estuarine tidal flats at each site. The variety of the prey species occupying different habitats indicates that their foraging areas extend to a wide range of estuarine tidal flats from the upper to lower littoral zones. The physalopterid nematode Heliconema anguillae was found parasitic in eel stomachs in both estuaries. The prevalence of the nematode was higher in the estuary in Kagoshima Bay (100%) than that in the Ariake Sea (43%), although the intensity in the former (4-94 nematodes per infected stomach) was comparable to that of the latter (2-96). The relationship between the nematode infection and the dietary items of Japanese eels is discussed.

  4. Donor life stage influences juvenile American eel Anguilla rostrata attraction to conspecific chemical cues

    Science.gov (United States)

    Galbraith, Heather S.; Blakeslee, Carrie J.; Schmucker, Andrew K.; Johnson, Nicholas; Hansen, Michael J.; Li, Weiming

    2017-01-01

    The present study investigated the potential role of conspecific chemical cues in inland juvenile American eel Anguilla rostrata migrations by assessing glass eel and 1 year old elver affinities to elver washings, and elver affinity to adult yellow eel washings. In two-choice maze assays, glass eels were attracted to elver washings, but elvers were neither attracted to nor repulsed by multiple concentrations of elver washings or to yellow eel washings. These results suggest that A. rostrata responses to chemical cues may be life-stage dependent and that glass eels moving inland may use the odour of the previous year class as information to guide migration. The role of chemical cues and olfaction in eel migrations warrants further investigation as a potential restoration tool.

  5. Behaviour and passage of European silver eels (Anguilla anguilla at a small hydropower plant during their downstream migration Comportement et passage de l’anguille argentée (Anguilla anguilla au niveau d’une petite centrale hydroélectrique lors de sa migration de dévalaison

    Directory of Open Access Journals (Sweden)

    De-Oliveira E.

    2010-09-01

    Full Text Available Between 2004 and 2007, 116 downstream migrant silver eels (Anguilla anguilla were monitored at a hydropower plant on the Gave de Pau river in South-West France using radio and PIT telemetry. The objectives of the study were: (i to determine the environmental conditions when eels arrived and passed the facility; (ii to determine the rate of eel escapement (passage other than via the turbines; (iii to describe the behaviour of eels faced with the intake structure and the permeability of the intake trashracks for the different sizes of eel; and (iv to determine whether surface bypasses originally designed for salmon could be effective for eels. Five types of behaviour of silver eels in the forebay and at the plant intakes were identified. The study showed the key factor influencing both eel behaviour and the route taken through the plant was variation in river discharge. Escapement rate was related to eel length and the spill flow to river flow ratio, which could be described by a logistic regression model. The surface bypasses originally designed for salmon were found to aid downstream eel migration significantly. At velocities < 0.40 m·s−1, no eels, even the largest, for which the racks are a physical barrier, were found impinged on the trashracks. De 2004 à 2007, une étude sur la migration de dévalaison de l’anguille argentée européenne (Anguilla anguilla a été menée sur la centrale hydroélectrique de Baigts sur le Gave de Pau dans le Sud-Ouest de la France. Cette étude, au cours de laquelle 116 individus ont été suivis par télémétrie PIT et radio, avait pour objectifs : (i de déterminer les conditions de milieu propices à l’arrivée sur site et au franchissement de l’aménagement; (ii de déterminer les taux d’échappement (passages par des voies autres que les turbines; (iii d’analyser le comportement des anguilles devant les ouvrages et la perméabilité des grilles de la prise d’eau en fonction de la taille

  6. Light impacts embryonic and early larval development of the European eel, Anguilla anguilla

    DEFF Research Database (Denmark)

    Politis, Sebastian Nikitas; Butts, Ian; Tomkiewicz, Jonna

    2014-01-01

    Little is known about the natural ecology of European eel during early life history. Weextend our understandings on the ecology of this species by studying howearly life stages perform under various light regimes.We assessed the effects of intensity, photoperiod (12:12 and 24:0 h light/dark) and ......Little is known about the natural ecology of European eel during early life history. Weextend our understandings on the ecology of this species by studying howearly life stages perform under various light regimes.We assessed the effects of intensity, photoperiod (12:12 and 24:0 h light...... stages. In particular, for the 12:12 h photoperiod, embryonic survival, until 26 h post-fertilization was significantly higher when reared under low (62 ± 13%) than those reared under high intensity light (42 ± 13%). Furthermore, embryos reared in low light had a higher hatch success (16 ± 7%) than those...... in high intensity light (12 ± 7%). Larval yolk-sac area was significantly affected by photoperiod and body area was significantly affected by the interaction between intensity × photoperiod. The highest incidence of deformities (75%) occurred when embryos were reared in high intensity white light under...

  7. Relationships between individual behaviour and morphometry under different experimental conditions of temperature and feeding in glass eels (Anguilla anguilla

    Directory of Open Access Journals (Sweden)

    A. Bardonnet

    2008-01-01

    Full Text Available After Anguilla anguilla larvae reach the European coast, metamorphosing glass eels exhibit an estuarine migration phase and can potentially colonize the continental area. Associated behaviours to upstream movement in estuary and river basin differ strongly: passive tidal transport in estuary, active swimming beyond the upstream tidal limit. Moreover, the migratory behaviour may shift towards a density-dependent dispersal beyond this limit. A positive relationship has previously been established between glass eels’ body condition and migratory behaviour in estuary and also higher in the river basin. An experiment was settled to test for the density-dependent versus migratory behaviour under controlled conditions. The relationships between some behaviours (swimming, grouping, feeding, and aggressiveness and body condition was investigated at the individual level. Two controlled factors were crossed, leading to four combinations of high and low levels of food and temperature. The high level of food led to a lesser loss in body condition. Swimming activity was positively related to initial body condition and loss in body condition, but these two variables were not related to aggressiveness. We conclude that the density-dependent dispersal hypothesis was not reinforced by these present results.

  8. Relationships between individual behaviour and morphometry under different experimental conditions of temperature and feeding in glass eels (Anguilla anguilla

    Directory of Open Access Journals (Sweden)

    Bardonnet A.

    2009-02-01

    Full Text Available After Anguilla anguilla larvae reach the European coast, metamorphosing glass eels exhibit an estuarine migration phase and can potentially colonize the continental area. Associated behaviours to upstream movement in estuary and river basin differ strongly: passive tidal transport in estuary, active swimming beyond the upstream tidal limit. Moreover, the migratory behaviour may shift towards a density-dependent dispersal beyond this limit. A positive relationship has previously been established between glass eels’ body condition and migratory behaviour in estuary and also higher in the river basin. An experiment was settled to test for the density-dependent versus migratory behaviour under controlled conditions. The relationships between some behaviours (swimming, grouping, feeding, and aggressiveness and body condition was investigated at the individual level. Two controlled factors were crossed, leading to four combinations of high and low levels of food and temperature. The high level of food led to a lesser loss in body condition. Swimming activity was positively related to initial body condition and loss in body condition, but these two variables were not related to aggressiveness. We conclude that the density-dependent dispersal hypothesis was not reinforced by these present results.

  9. Regional variation in otolith Sr:Ca ratios of African longfinned eel Anguilla mossambica and mottled eel Anguilla marmorata: a challenge to the classic tool for reconstructing migratory histories of fishes.

    Science.gov (United States)

    Lin, Y-J; Jessop, B M; Weyl, O L F; Iizuka, Y; Lin, S-H; Tzeng, W-N; Sun, C-L

    2012-07-01

    Otolith Sr:Ca ratios of the African longfinned eel Anguilla mossambica and giant mottled eel Anguilla marmorata from nine freshwater sites in four rivers of South Africa were analysed to reconstruct their migratory life histories between freshwater and saltwater habitats. For A. mossambica, the Sr:Ca ratios in the otolith edge differed significantly among rivers and had large effect sizes, but did not differ among sites within a river. Otolith Sr:Ca ratios did not differ among rivers for A. marmorata. When rivers were pooled, the edge Sr:Ca ratios of A. mossambica were not significantly different from those of A. marmorata. According to the river-specific critical Sr:Ca ratio distinguishing freshwater from saltwater residence, most A. mossambica and A. marmorata had saltwater habitat experience after settlement in fresh water. This was primarily during their elver stage or early in the yellow eel stage. During the middle and late yellow eel stage, freshwater residency was preferred and only sporadic visits were made to saltwater habitats. The data also suggest that regional variations in otolith Sr:Ca ratios affect the critical Sr:Ca value and are a challenge for the reconstruction of migratory life histories that should be explicitly considered to avoid bias and uncertainty. © 2012 The Authors. Journal of Fish Biology © 2012 The Fisheries Society of the British Isles.

  10. Draft genome of the American Eel (Anguilla rostrata).

    Science.gov (United States)

    Pavey, Scott A; Laporte, Martin; Normandeau, Eric; Gaudin, Jérémy; Letourneau, Louis; Boisvert, Sébastien; Corbeil, Jacques; Audet, Céline; Bernatchez, Louis

    2017-07-01

    Freshwater eels (Anguilla sp.) have large economic, cultural, ecological and aesthetic importance worldwide, but they suffered more than 90% decline in global stocks over the past few decades. Proper genetic resources, such as sequenced, assembled and annotated genomes, are essential to help plan sustainable recoveries by identifying physiological, biochemical and genetic mechanisms that caused the declines or that may lead to recoveries. Here, we present the first sequenced genome of the American eel. This genome contained 305 043 contigs (N50 = 7397) and 79 209 scaffolds (N50 = 86 641) for a total size of 1.41 Gb, which is in the middle of the range of previous estimations for this species. In addition, protein-coding regions, including introns and flanking regions, are very well represented in the genome, as 95.2% of the 458 core eukaryotic genes and 98.8% of the 248 ultra-conserved subset were represented in the assembly and a total of 26 564 genes were annotated for future functional genomics studies. We performed a candidate gene analysis to compare three genes among all three freshwater eel species and, congruent with the phylogenetic relationships, Japanese eel (A. japanica) exhibited the most divergence. Overall, the sequenced genome presented in this study is a crucial addition to the presently available genetic tools to help guide future conservation efforts of freshwater eels. © 2016 John Wiley & Sons Ltd.

  11. A question of origin: dioxin-like PCBs and their relevance in stock management of European eels.

    Science.gov (United States)

    Freese, Marko; Sühring, Roxana; Pohlmann, Jan-Dag; Wolschke, Hendrik; Magath, Victoria; Ebinghaus, Ralf; Hanel, Reinhold

    2016-01-01

    The stock of European Eel (Anguilla anguilla L.) has reached an all-time low in 2011. Spawner quality of mature eels in terms of health status and fitness is considered one of the key elements for successful migration and reproduction. Dioxin-like Polychlorinated Biphenyls (dl-PCBs) are known persistent organic pollutants potentially affecting the reproductive capability and health status of eels throughout their entire lifetime. In this study, muscle tissue samples of 192 European eels of all continental life stages from 6 different water bodies and 13 sampling sites were analyzed for contamination with lipophilic dl-PCBs to investigate the potential relevance of the respective habitat in light of eel stock management. Results of this study reveal habitat-dependent and life history stage-related accumulation of targeted PCBs. Sum concentrations of targeted PCBs differed significantly between life stages and inter-habitat variability in dl-PCB levels and -profiles was observed. Among all investigated life stages, migrant silver eels were found to be the most suitable life history stage to represent their particular water system due to habitat dwell-time and their terminal contamination status. With reference to a possible negative impact of dl-PCBs on health and the reproductive capability of eels, it was hypothesized that those growing up in less polluted habitats have a better chance to produce healthy offspring than those growing up in highly polluted habitats. We suggest that the contamination status of water systems is fundamental for the life cycle of eels and needs to be considered in stock management and restocking programs.

  12. Loss of European silver eel passing a hydropower station

    DEFF Research Database (Denmark)

    Pedersen, Michael Ingemann; Jepsen, Niels; Aarestrup, Kim

    2012-01-01

    The aim of this study was to assess escapement success of silver eels, Anguilla anguilla (L.), in a lowland river while passing a reservoir and a hydropower station. It was hypothesized that passage success would be lowest at the hydropower station and that survival and migration speed would...... that within the study period, only 23% of the tagged eels reached the tidal limit, mainly due to difficulties in passing the hydropower dam. With such high loss-rates, the escapement goals set in the management plan cannot be achieved...

  13. Growth and seasonal behavior of Anguilla anguilla in the River Minho tidal freshwater wetlands

    Directory of Open Access Journals (Sweden)

    Helena Correia

    2015-11-01

    Full Text Available The River Minho estuary, located on the northwest coast of the Iberian Peninsula, is a mesotidal estuary, partially mixed that during the period of high floods it tends to evolve towards a salt wedge estuary. The influence of spring tides extends approximately 40 km upstream and the tidal freshwater wetlands (TFWs are located in the upper 30 km. The Minho estuary is part of a Natura 2000 site, which includes the entire international section of the river being considered a very important river concerning migratory fish species. In the River Minho TFWs several fish species have ecological and economic value (Salmo trutta, Alosa fallax, Platichthys flesus, Anguilla anguilla, Salmo salar, Alosa alosa and Petromyzon marinus. European eel, A. anguilla, is in Appendix II of CITES list, that includes species not necessarily threatened with extinction, but in which trade must be controlled in order to avoid utilization incompatible with their survival. Between January 2007 and December 2014, in a selected semi-enclosed area of TFW and using 5 fyke-nets, were captured 1303 eels. All eels were measured and weighted, ocular index was determined and also marked with pit-tags and released in the same area. During these 8 years of work, around 15% of the total captured eels were recaptured once, less than 3% were recapture twice, less than 1% three times and 3 eels were recaptured 4 times. Eels marked in 2009 are until now the ones that were recaptured more times. Biological data as eel growth, seaward migration state, seasonal differences of by-catch will be crossed with abiotic data namely river flow, precipitation and water temperature.

  14. The giant mottled eel, Anguilla marmorata, uses blue-shifted rod photoreceptors during upstream migration.

    Science.gov (United States)

    Wang, Feng-Yu; Fu, Wen-Chun; Wang, I-Li; Yan, Hong Young; Wang, Tzi-Yuan

    2014-01-01

    Catadromous fishes migrate between ocean and freshwater during particular phases of their life cycle. The dramatic environmental changes shape their physiological features, e.g. visual sensitivity, olfactory ability, and salinity tolerance. Anguilla marmorata, a catadromous eel, migrates upstream on dark nights, following the lunar cycle. Such behavior may be correlated with ontogenetic changes in sensory systems. Therefore, this study was designed to identify changes in spectral sensitivity and opsin gene expression of A. marmorata during upstream migration. Microspectrophotometry analysis revealed that the tropical eel possesses a duplex retina with rod and cone photoreceptors. The λmax of rod cells are 493, 489, and 489 nm in glass, yellow, and wild eels, while those of cone cells are 508, and 517 nm in yellow, and wild eels, respectively. Unlike European and American eels, Asian eels exhibited a blue-shifted pattern of rod photoreceptors during upstream migration. Quantitative gene expression analyses of four cloned opsin genes (Rh1f, Rh1d, Rh2, and SWS2) revealed that Rh1f expression is dominant at all three stages, while Rh1d is expressed only in older yellow eel. Furthermore, sequence comparison and protein modeling studies implied that a blue shift in Rh1d opsin may be induced by two known (N83, S292) and four putative (S124, V189, V286, I290) tuning sites adjacent to the retinal binding sites. Finally, expression of blue-shifted Rh1d opsin resulted in a spectral shift in rod photoreceptors. Our observations indicate that the giant mottled eel is color-blind, and its blue-shifted scotopic vision may influence its upstream migration behavior and habitat choice.

  15. A century of research on the larval distributions of the Atlantic eels: a re-examination of the data

    DEFF Research Database (Denmark)

    Miller, Michael J.; Bonhommeau, Sylvain; Munk, Peter

    2015-01-01

    The spawning areas of the Atlantic freshwater eels were discovered about a century ago by the Danish scientist Johannes Schmidt who after years of searching found newly hatched larvae of the European eel, Anguilla anguilla, and the American eel, Anguilla rostrata, in the southern Sargasso Sea...... comprehensive database that includes 22612 A. anguilla and 9634 A. rostrata leptocephali, which provides a detailed view of the spatial and temporal distributions and size of the larvae across the Atlantic basin and in the Mediterranean Sea. The differences in distributions, maximum sizes, and growth rates...

  16. The giant mottled eel, Anguilla marmorata, uses blue-shifted rod photoreceptors during upstream migration.

    Directory of Open Access Journals (Sweden)

    Feng-Yu Wang

    Full Text Available Catadromous fishes migrate between ocean and freshwater during particular phases of their life cycle. The dramatic environmental changes shape their physiological features, e.g. visual sensitivity, olfactory ability, and salinity tolerance. Anguilla marmorata, a catadromous eel, migrates upstream on dark nights, following the lunar cycle. Such behavior may be correlated with ontogenetic changes in sensory systems. Therefore, this study was designed to identify changes in spectral sensitivity and opsin gene expression of A. marmorata during upstream migration. Microspectrophotometry analysis revealed that the tropical eel possesses a duplex retina with rod and cone photoreceptors. The λmax of rod cells are 493, 489, and 489 nm in glass, yellow, and wild eels, while those of cone cells are 508, and 517 nm in yellow, and wild eels, respectively. Unlike European and American eels, Asian eels exhibited a blue-shifted pattern of rod photoreceptors during upstream migration. Quantitative gene expression analyses of four cloned opsin genes (Rh1f, Rh1d, Rh2, and SWS2 revealed that Rh1f expression is dominant at all three stages, while Rh1d is expressed only in older yellow eel. Furthermore, sequence comparison and protein modeling studies implied that a blue shift in Rh1d opsin may be induced by two known (N83, S292 and four putative (S124, V189, V286, I290 tuning sites adjacent to the retinal binding sites. Finally, expression of blue-shifted Rh1d opsin resulted in a spectral shift in rod photoreceptors. Our observations indicate that the giant mottled eel is color-blind, and its blue-shifted scotopic vision may influence its upstream migration behavior and habitat choice.

  17. Are dioxin-like contaminants responsible for the eel ( Anguilla anguilla) drama?

    Science.gov (United States)

    Palstra, A. P.; van Ginneken, V. J. T.; Murk, A. J.; van den Thillart, G. E. E. J. M.

    2006-03-01

    Eel populations worldwide are dangerously close to collapsing. Our study is the first to show that current levels of dioxin-like contaminants are strong candidates because of their devastating effects on development and survival of eel embryos. Female and male silver eels were artificially stimulated to maturation and reproduction by treatment with carp pituitary extracts and hCG, respectively. During maturation of female European silver eels, about 60 g fat per kg eel is incorporated in the oocytes. Together with the fat, however, persistent organic pollutants such as dioxin-like polychlorinated biphenyls (PCBs) are incorporated too. The total dioxin-like toxic potency of the individual gonad batches was determined as 2,3,7,8-tetrachlorodibenzo- p-dioxine equivalents (TEQs), using an in vitro reporter gene assay. The observed differences in development and survival showed a significant negative correlation with the TEQ levels in the gonads, already at levels far below the maximal allowable level for fish consumption, i.e., 4 ng TEQ/kg fish. The clear inverse relationship between the TEQ level and the survival period of the fertilised eggs strongly suggests that the current levels of dioxin-like compounds seriously impair the reproduction of the European eel. The peak of the environmental levels of dioxin-like PCBs and the decline of eel coincide worldwide, further suggesting that, in addition to other threats, these contaminants contributed significantly to the current collapse in eel populations.

  18. Evaluation of surgical implantation of electronic tags in European eel and effects of different suture materials

    DEFF Research Database (Denmark)

    Thorstad, Eva B.; Økland, Finn; Westerberg, Håkan

    2013-01-01

    Effects of implanting data-storage tags in European eel, Anguilla anguilla, and the suitability of different suture materials (braided permanent silk, permanent monofilament, absorbable and absorbable antibacterial) were examined. The tags consisted of an electronic unit and three floats on a wire....... Antibacterial treatment had no effect on inflammation or healing rates. After 6 months, the tag started to become expelled through the incision in five fish (12%). The internal reaction appeared stronger around the floats, suggesting that the coating material of the floats created a tissue reaction, which...

  19. A semi-automated method of monitoring dam passage of American Eels Anguilla rostrata

    Science.gov (United States)

    Welsh, Stuart A.; Aldinger, Joni L.

    2014-01-01

    Fish passage facilities at dams have become an important focus of fishery management in riverine systems. Given the personnel and travel costs associated with physical monitoring programs, automated or semi-automated systems are an attractive alternative for monitoring fish passage facilities. We designed and tested a semi-automated system for eel ladder monitoring at Millville Dam on the lower Shenandoah River, West Virginia. A motion-activated eel ladder camera (ELC) photographed each yellow-phase American Eel Anguilla rostrata that passed through the ladder. Digital images (with date and time stamps) of American Eels allowed for total daily counts and measurements of eel TL using photogrammetric methods with digital imaging software. We compared physical counts of American Eels with camera-based counts; TLs obtained with a measuring board were compared with TLs derived from photogrammetric methods. Data from the ELC were consistent with data obtained by physical methods, thus supporting the semi-automated camera system as a viable option for monitoring American Eel passage. Time stamps on digital images allowed for the documentation of eel passage time—data that were not obtainable from physical monitoring efforts. The ELC has application to eel ladder facilities but can also be used to monitor dam passage of other taxa, such as crayfishes, lampreys, and water snakes.

  20. Evaluation of three telemetry transmitter attachment methods for female silver-phase American eels ( Anguilla rostrata Lesueur)

    DEFF Research Database (Denmark)

    Cottrill, R.A.; Økland, F.; Aarestrup, Kim

    2006-01-01

    Declines in juvenile American eel (Anguilla rostrata Lesueur) abundance have led to concern about the impacts of anthropogenic structures on eel migration patterns. Telemetry provides an insightful tool for examining the movements of eels around these structures. Although there have been a number...... of studies investigating movements of Anguillid eels, using a variety of transmitter attachment techniques, there are few published evaluations of the effects of various tag attachment procedures. Hence, the effects of three telemetry attachment procedures were evaluated for female silver phase American eels...... of silver-phase American eels is not affected by the presence of telemetry transmitters or the method of transmitter attachment, even though swim performance decreases. However, transmitter retention rates varied considerably after the 12-week experimental period. Three gastric tags were regurgitated...

  1. Magnetic compass orientation in the European eel.

    Directory of Open Access Journals (Sweden)

    Caroline M F Durif

    Full Text Available European eel migrate from freshwater or coastal habitats throughout Europe to their spawning grounds in the Sargasso Sea. However, their route (~ 6000 km and orientation mechanisms are unknown. Several attempts have been made to prove the existence of magnetoreception in Anguilla sp., but none of these studies have demonstrated magnetic compass orientation in earth-strength magnetic field intensities. We tested eels in four altered magnetic field conditions where magnetic North was set at geographic North, South, East, or West. Eels oriented in a manner that was related to the tank in which they were housed before the test. At lower temperature (under 12°C, their orientation relative to magnetic North corresponded to the direction of their displacement from the holding tank. At higher temperatures (12-17°C, eels showed bimodal orientation along an axis perpendicular to the axis of their displacement. These temperature-related shifts in orientation may be linked to the changes in behavior that occur between the warm season (during which eels are foraging and the colder fall and winter (during which eels undertake their migrations. These observations support the conclusion that 1. eels have a magnetic compass, and 2. they use this sense to orient in a direction that they have registered moments before they are displaced. The adaptive advantage of having a magnetic compass and learning the direction in which they have been displaced becomes clear when set in the context of the eel's seaward migration. For example, if their migration is halted or blocked, as it is the case when environmental conditions become unfavorable or when they encounter a barrier, eels would be able to resume their movements along their old bearing when conditions become favorable again or when they pass by the barrier.

  2. Magnetic compass orientation in the European eel.

    Science.gov (United States)

    Durif, Caroline M F; Browman, Howard I; Phillips, John B; Skiftesvik, Anne Berit; Vøllestad, L Asbjørn; Stockhausen, Hans H

    2013-01-01

    European eel migrate from freshwater or coastal habitats throughout Europe to their spawning grounds in the Sargasso Sea. However, their route (~ 6000 km) and orientation mechanisms are unknown. Several attempts have been made to prove the existence of magnetoreception in Anguilla sp., but none of these studies have demonstrated magnetic compass orientation in earth-strength magnetic field intensities. We tested eels in four altered magnetic field conditions where magnetic North was set at geographic North, South, East, or West. Eels oriented in a manner that was related to the tank in which they were housed before the test. At lower temperature (under 12°C), their orientation relative to magnetic North corresponded to the direction of their displacement from the holding tank. At higher temperatures (12-17°C), eels showed bimodal orientation along an axis perpendicular to the axis of their displacement. These temperature-related shifts in orientation may be linked to the changes in behavior that occur between the warm season (during which eels are foraging) and the colder fall and winter (during which eels undertake their migrations). These observations support the conclusion that 1. eels have a magnetic compass, and 2. they use this sense to orient in a direction that they have registered moments before they are displaced. The adaptive advantage of having a magnetic compass and learning the direction in which they have been displaced becomes clear when set in the context of the eel's seaward migration. For example, if their migration is halted or blocked, as it is the case when environmental conditions become unfavorable or when they encounter a barrier, eels would be able to resume their movements along their old bearing when conditions become favorable again or when they pass by the barrier.

  3. Pop up satellite tags impair swimming performance and energetics of the European eel (Anguilla anguilla)

    DEFF Research Database (Denmark)

    Methling, Caroline; Tudorache, Christian; Skov, Peter Vilhelm

    2011-01-01

    Pop-up satellite archival tags (PSATs) have recently been applied in attempts to follow the oceanic spawning migration of the European eel. PSATs are quite large, and in all likelihood their hydraulic drag constitutes an additional cost during swimming, which remains to be quantified, as does...... the potential implication for successful migration. Silver eels (L(T)=598.6 +/- 29 mm SD, N = 9) were subjected to swimming trials in a Steffensen-type swim tunnel at increasing speeds of 0.3-0.9 body lengths s(-1), first without and subsequently with, a scaled down PSAT dummy attached. The tag significantly...... increased oxygen consumption (MO(2)) during swimming and elevated minimum cost of transport (COT(min)) by 26 Standard (SMR) and active metabolic rate (AMR) as well as metabolic scope remained unaffected, suggesting that the observed effects were caused by increased drag. Optimal swimming speed (U...

  4. Evaluating the adaptive potential of the European eel: is the immunogenetic status recovering?

    Directory of Open Access Journals (Sweden)

    Miguel Baltazar-Soares

    2016-04-01

    Full Text Available The recent increased integration of evolutionary theory into conservation programs has greatly improved our ability to protect endangered species. A common application of such theory links population dynamics and indices of genetic diversity, usually estimated from neutrally evolving markers. However, some studies have suggested that highly polymorphic adaptive genes, such as the immune genes of the Major Histocompatibility Complex (MHC, might be more sensitive to fluctuations in population dynamics. As such, the combination of neutrally- and adaptively-evolving genes may be informative in populations where reductions in abundance have been documented. The European eel (Anguilla anguilla underwent a drastic and well-reported decline in abundance in the late 20th century and still displays low recruitment. Here we compared genetic diversity indices estimated from neutral (mitochondrial DNA and microsatellites and adaptive markers (MHC between two distinct generations of European eels. Our results revealed a clear discrepancy between signatures obtained for each class of markers. Although mtDNA and microsatellites showed no changes in diversity between the older and the younger generations, MHC diversity revealed a contemporary drop followed by a recent increase. Our results suggest ongoing gain of MHC genetic diversity resulting from the interplay between drift and selection and ultimately increasing the adaptive potential of the species.

  5. Anguilla rostrata glass eel migration and recruitment in the estuary and Gulf of St Lawrence.

    Science.gov (United States)

    Dutil, J-D; Dumont, P; Cairns, D K; Galbraith, P S; Verreault, G; Castonguay, M; Proulx, S

    2009-06-01

    This study describes catches of Anguilla rostrata glass eels and associated oceanographic conditions in the St Lawrence Estuary and Gulf. Ichthyoplankton survey data suggest that they enter the Gulf primarily in May, migrate at the surface at night, and disperse broadly once they have passed Cabot Strait. They arrive in estuaries beginning at about mid-June and through the month of July. Migration extends west up to Québec City, in the freshwater zone of the St Lawrence Estuary, 1000 km west of Cabot Strait. Anguilla rostrata glass eels travel between Cabot Strait and receiving estuaries at a straight-line ground speed of c. 10-15 km day(-1). Catches of fish per unit effort in estuaries in the St Lawrence system are much lower than those reported for the Atlantic coast of Canada. Low abundance of A. rostrata glass eels in the St Lawrence system may be due to cold surface temperatures during the migration period which decrease swimming capacity, long distances from the spawning ground to Cabot Strait and from Cabot Strait to the destination waters (especially the St Lawrence River), complex circulation patterns, and hypoxic conditions in bottom waters of the Laurentian Channel and the St Lawrence Estuary.

  6. Methyl mercury bioaccumulation in long-finned eels, Anguilla dieffenbachii, from three rivers in Otago, New Zealand.

    Science.gov (United States)

    Redmayne, A C; Kim, J P; Closs, G P; Hunter, K A

    2000-10-30

    This research focuses on mercury (Hg) bioaccumulation in New Zealand long-tinned eels (Anguilla dieffenbachii) from the aquatic environment. Total Hg (HgT) and methyl mercury (MeHg) concentrations were determined in muscle tissue from eels living in three South Island rivers dominated respectively by urban, native bush and agricultural land-uses. Most of the Hg in eels was MeHg (> 84%) and the MeHg concentrations increased linearly with both length and eel age for a given river habitat. The annual growth rates for eels from the urban and agricultural streams were greater than for eels from the native bush stream. The average MeHg accumulation rate was significantly higher for the eels in the agricultural stream compared with either the urban or native bush catchments. These results are probably due to a combination of factors and further investigations in the lower food web are necessary to elucidate the exact mechanisms of MeHg bioaccumulation in these creatures.

  7. Vg mRNA induction in an endangered fish species (Anguilla anguilla) from the Loire estuary (France).

    Science.gov (United States)

    Blanchet-Letrouvé, Isabelle; Lafont, Anne-Gaëlle; Poirier, Laurence; Baloche, Sylvie; Zalouk-Vergnoux, Aurore; Dufour, Sylvie; Mouneyrac, Catherine

    2013-11-01

    Estuarine zones are extremely fragile due to increasing stress from anthropogenic activities. Among those, the Loire estuary (France) is potentially exposed to various contaminants including Endocrine Disruptors Compounds (EDCs) able to impact the reproduction physiology of fish. The European eel (Anguilla anguilla), endangered fish species, is apparently not relevant, in its yellow stage, to monitor the effects of endocrine disruption. Despite this weakly responsiveness, this study aimed to investigate whether European eel from the Loire estuary may still be the subject of estrogenic disruption quantifying the hepatic Vg gene expression according to gender and sexual stage. Vitellogenin (Vg) appears as a valuable biomarker of EDCs, as well as for exposure and effects. Quantitative real-time Reverse Transcription Polymerase Chain Reaction (q RT PCR) was used in this study to amplify responses of hepatic Vg transcripts. European eels were sampled in May 2009 (N=57) and November 2010 (during the downstream migration, N=10) in two sites of the Loire estuary with different ecological conditions and contamination pressures (upstream: Varades; downstream: Nantes). Reproductive (gender, sexual maturity stage) and biometric parameters of collected eels were determined. A laboratory exposure of silver male to steroid hormones (Testosterone (T), 11-KetoTestosterone (11-KT), Estradiol (E2)) was conducted in parallel to validate the q RT PCR approach on hepatic Vg mRNA. Results demonstrated the responsiveness of exposed silver male eels, since hepatic mRNA Vg induction was observed in E2 treated males compared to control specimens. In the field, results of female silver eels reflected large inter-individual differences in the activation of hepatic Vg at silvering. However, while only female silver eels should express hepatic Vg mRNA, quantifiable levels were also detected in a proportion of 38% of the other individuals sampled, normally not inclined to express it, those being

  8. Effects of recombinant eel growth hormone on the uptake of ( sup 35 S)sulfate by ceratobranchial cartilages of the Japanese eel, Anguilla japonica

    Energy Technology Data Exchange (ETDEWEB)

    Duan, C.M.; Inui, Y. (Univ. of Tokyo (Japan))

    1990-08-01

    Effects of growth hormone (GH) on the synthesis of mucopolysaccharide by ceratobranchial cartilages of the Japanese eel, Anguilla japonica, were examined by monitoring the in vitro uptake of ({sup 35}S)sulfate. The ({sup 35}S)sulfate uptake decreased rapidly to one-third of the initial level during the first 3 days after hypophysectomy, and decreased gradually thereafter. When hypophysectomized eels were injected intramuscularly with recombinant eel GH (2 micrograms/g), the plasma GH concentrations increased maximally after 6 hr, and declined rapidly thereafter. On the other hand, the sulfate uptake increased significantly after 12 hr, and high levels were maintained until 48 hr. The stimulating effect of GH was dose dependent (0.02-2 micrograms/g). However, the addition of eel GH (0.05-5 micrograms/ml) to the culture medium did not affect the sulfate uptake by hypophysectomized eel cartilages, suggesting that the stimulative action of GH on the sulfate uptake by the cartilages is indirect.

  9. The eel immune system: present knowledge and the need for research

    DEFF Research Database (Denmark)

    Nielsen, Michael Engelbrecht; Esteve-Gassent, M. D.

    2006-01-01

    The European eel, Anguilla anguilla, is one of the most important warm water fish species cultured in southern Europe and the Mediterranean as well as in northern countries including Germany, the Netherlands and Denmark. The Japanese eel, A. japonica, is an important cultured fish in several...... Asiatic countries including Japan, China and Taiwan. During recent decades, research has been performed to elucidate the immune response of these species against different pathogens (viruses, bacteria or parasites). Nevertheless, there is very limited information in terms of both cellular and humoral...

  10. Induced maturation of eel Anguilla bicolor using different hormone combination

    Directory of Open Access Journals (Sweden)

    Agus Oman Sudrajat

    2015-10-01

    Full Text Available ABSTRACT Artificial reproduction of eel Anguilla bicolor is not yet well-established because of insufficient broodstock number. In this research, induction of Indonesian eel gonad maturation was performed by hormonal with a combination of pregnant mare serum gonadotropin (PMSG, human chorionic gonadotropin (HCG antidopamin and recombinant growth hormone (rGH. This research consisted of five treatments namely: control (NaCl 0,9%, PMSG 20 IU/ kg, PMSG 20 IU/kg + antidopamin 10 ppm/kg, PMSG 20 IU/kg + antidopamin 10 ppm/kg + rGH 10 μg/kg dan PMSG 20 IU/kg + HCG 10 IU/kg. Each treatment contained 10 fishes. Hormonal induction was conducted by intramuscular injections, as much as five times at intervals of seven days. Furthermore observations on gonadal development were performed after injection for 21 days. The results showed that the treatment generated pregnancy level of 100%, while control was 0%. The best treatment was PMSG 20 IU/kg + antidopamin 10 ppm/kg+ rGH 10 μg/kg, seen from a more mature phase of the gametes, spermatocytes in male and oocytes with perinukleolar phase in female fish. Eel at the body weight of 120.4 to 207.8 g and at the body length of 40.9 to 43.1 cm was male, at the body weight of 274.8 g and at the body length of 47 cm was in intersexual phase, and at the body weight of 323.4 g and at the body length of 53 cm was female. Keywords: Anguilla bicolor, antidopamin, hormones, PMSG, rGH, HCG  ABSTRAK Pemijahan ikan sidat secara buatan belum dapat dilakukan karena keterbatasan induk matang gonad. Penelitian ini dilakukan untuk mengetahui pengaruh pemberian hormon terhadap percepatan proses perkembangan gonad ikan sidat (Anguilla bicolor. Hormon yang digunakan adalah kombinasi dari pregnant mare serum gonadotropin (PMSG, human chorionic gonadotropin (HCG, antidopamin dan recombinant growth hormone (rGH. Induksi hormonal untuk mempercepat perkembangan gonad ikan sidat dilakukan melalui lima perlakuan yaitu yaitu kontrol

  11. The Giant Mottled Eel, Anguilla marmorata, Uses Blue-Shifted Rod Photoreceptors during Upstream Migration

    OpenAIRE

    Wang, Feng-Yu; Fu, Wen-Chun; Wang, I-Li; Yan, Hong Young; Wang, Tzi-Yuan

    2014-01-01

    Catadromous fishes migrate between ocean and freshwater during particular phases of their life cycle. The dramatic environmental changes shape their physiological features, e.g. visual sensitivity, olfactory ability, and salinity tolerance. Anguilla marmorata, a catadromous eel, migrates upstream on dark nights, following the lunar cycle. Such behavior may be correlated with ontogenetic changes in sensory systems. Therefore, this study was designed to identify changes in spectral sensitivity ...

  12. Gastrointestinal and metabolic effects of feeding schedule on voluntary feed intake and growth of European eel, Anguilla anguilla

    NARCIS (Netherlands)

    Heinsbroek, L.T.N.; Goedegebuur, B.J.; Bloemhof, G.; Flach, R.B.; Jong, de G.D.C.

    2008-01-01

    Gastrointestinal and metabolic influences on short- and medium-term control of voluntary feed intake of European eel were investigated for groups of fish fed at different feeding schedules: 1 meal 2 days(-1), 1 meal day(-1), 2 meals day(-1) and continuous feeding for 12 h and 24 h daily. For fish

  13. LEUKOCYTE DIFFERENTIAL OF ANGUILLID EEL, Anguilla bicolor McClelland, EXPOSED TO VARIED SALINITIES

    Directory of Open Access Journals (Sweden)

    Fita Fatimah

    2017-06-01

    Full Text Available The anguillid eel is a catadromous eel capable of inhabiting freshwater growth habitat and seawater spawning habitat throughout their life cycle. At the juvenile to mature stage, they inhabit freshwater then migrate to marine water to spawn. Changes in salinity, which is one of the stressful environmental factors for the eel, affect their physiological condition by increasing the leukocytes number. This increase is an adaptation method to improve their immune system as a response to salinity change. This study intended to evaluate the leukocyte differential of anguillid eel (Anguilla bicolor McClelland exposed to various salinities. This research applied a Completely Randomized Design. The treatment was three levels of saline media including 4 ppt, 15 ppt, and 30 ppt with five replicates. The independent variable was the different salinity, and the dependent variable was the leukocyte differential. The parameters measured consisted of the different percentage of neutrophils, lymphocytes, monocytes, and eosinophils in which the measurements administered after two months of the eel exposure. We analyzed the data with ANOVA at the confidence level of 95%. The results showed that exposure of salinity significantly affected the percentage of leukocyte differential (P < 0.05. The increase in salinity decreased the neutrophils and monocytes, but increased the lymphocytes, and showed no effect on eosinophils.

  14. Sympatric spawning but allopatric distribution of Anguilla japonica and Anguilla marmorata: temperature- and oceanic current-dependent sieving.

    Directory of Open Access Journals (Sweden)

    Yu-San Han

    Full Text Available Anguilla japonica and Anguilla marmorata share overlapping spawning sites, similar drifting routes, and comparable larval durations. However, they exhibit allopatric geographical distributions in East Asia. To clarify this ecological discrepancy, glass eels from estuaries in Taiwan, the Philippines, Indonesia, and China were collected monthly, and the survival rate of A. marmorata under varying water salinities and temperatures was examined. The composition ratio of these 2 eel species showed a significant latitude cline, matching the 24 °C sea surface temperature isotherm in winter. Both species had opposing temperature preferences for recruitment. A. marmorata prefer high water temperatures and die at low water temperatures. In contrast, A. japonica can endure low water temperatures, but their recruitment is inhibited by high water temperatures. Thus, A. japonica glass eels, which mainly spawn in summer, are preferably recruited to Taiwan, China, Korea, and Japan by the Kuroshio and its branch waters in winter. Meanwhile, A. marmorata glass eels, which spawn throughout the year, are mostly screened out in East Asia in areas with low-temperature coastal waters in winter. During summer, the strong northward currents from the South China Sea and Changjiang River discharge markedly block the Kuroshio invasion and thus restrict the approach of A. marmorata glass eels to the coasts of China and Korea. The differences in the preferences of the recruitment temperature for glass eels combined with the availability of oceanic currents shape the real geographic distribution of Anguilla japonica and Anguilla marmorata, making them "temperate" and "tropical" eels, respectively.

  15. Sympatric spawning but allopatric distribution of Anguilla japonica and Anguilla marmorata: temperature- and oceanic current-dependent sieving.

    Science.gov (United States)

    Han, Yu-San; Yambot, Apolinario V; Zhang, Heng; Hung, Chia-Ling

    2012-01-01

    Anguilla japonica and Anguilla marmorata share overlapping spawning sites, similar drifting routes, and comparable larval durations. However, they exhibit allopatric geographical distributions in East Asia. To clarify this ecological discrepancy, glass eels from estuaries in Taiwan, the Philippines, Indonesia, and China were collected monthly, and the survival rate of A. marmorata under varying water salinities and temperatures was examined. The composition ratio of these 2 eel species showed a significant latitude cline, matching the 24 °C sea surface temperature isotherm in winter. Both species had opposing temperature preferences for recruitment. A. marmorata prefer high water temperatures and die at low water temperatures. In contrast, A. japonica can endure low water temperatures, but their recruitment is inhibited by high water temperatures. Thus, A. japonica glass eels, which mainly spawn in summer, are preferably recruited to Taiwan, China, Korea, and Japan by the Kuroshio and its branch waters in winter. Meanwhile, A. marmorata glass eels, which spawn throughout the year, are mostly screened out in East Asia in areas with low-temperature coastal waters in winter. During summer, the strong northward currents from the South China Sea and Changjiang River discharge markedly block the Kuroshio invasion and thus restrict the approach of A. marmorata glass eels to the coasts of China and Korea. The differences in the preferences of the recruitment temperature for glass eels combined with the availability of oceanic currents shape the real geographic distribution of Anguilla japonica and Anguilla marmorata, making them "temperate" and "tropical" eels, respectively.

  16. Silvering of European eel (Anguilla anguilla L.): seasonal changes of morphological and metabolic parameters

    NARCIS (Netherlands)

    Ginneken, van V.; Durif, C.; Paul Balm, S.; Boot, R.; Verstegen, M.W.A.; Antonissen, E.; Thillart, van den G.

    2007-01-01

    The transformation of yellow eel into silver eel is called `silvering¿, and takes place prior to migration. We found the sedentary yellow phase in spring, the migratory silver phase in autumn, while August was a cross-over month. We used principal component analysis (PCA) to characterise the

  17. Tolerance of hypercapnic acidosis by the European eel, Anguilla anguilla

    DEFF Research Database (Denmark)

    McKenzie, DJ; Dalla Valle, AZ; Steffensen, JF

    2000-01-01

    to progressive hypercapnia (20 min at Pw,CO2 values of 10, 20, 40, 60 and 80 mmHg) caused a linear increase in arterial PCO2 (Pa,CO2) from 3.5 ± 0.4 mmHg in normocapnia to 44.9 ± 2.6 at Pw,CO2 = 80 mmHg, coupled to respective declines in arterial pH (pHa) from 7.86 ± 0.02 to 7.16 ± 0.04 and in arterial total O2...... content (ca,O2) from 9.6 ± 0.7 to 2.0 ± 0.5 vol%. There was a significant increase in fG and POP at Pw,CO2 values of 10, 20, 40 mmHg, then a decline in fG but further increase in POP at Pw,CO2 = 60 and 80 mmHg. Despite the severe acidosis and hypoxaemia, there were no significant effects on CO or O2...... uptake. Eels exposed for 3 months to chronic hypercapnia (Pw,CO2 values of control, 15, 30 or 45 mmHg) were anaesthetised, cannulated and recovered as described above, at the appropriate Pw,CO2. In all groups, Pa,CO2 was about 3 mmHg above Pw,CO2, and hypercapnic eels exhibited a marked accumulation...

  18. Maternal transfer of emerging brominated and chlorinated flame retardants in European eels

    Energy Technology Data Exchange (ETDEWEB)

    Sühring, Roxana, E-mail: roxana.suehring@hzg.de [Helmholtz-Zentrum Geesthacht, Centre for Materials and Coastal Research, Institute of Coastal Research, Department for Environmental Chemistry, Max-Planck-Strasse 1, 21502 Geesthacht (Germany); Leuphana University Lüneburg, Institute of Sustainable and Environmental Chemistry, Scharnhorststraße 1, 21335 Lüneburg (Germany); Freese, Marko [Thünen Institute of Fisheries Ecology, Palmaille 9, 22767 Hamburg (Germany); Schneider, Mandy [Leuphana University Lüneburg, Institute of Sustainable and Environmental Chemistry, Scharnhorststraße 1, 21335 Lüneburg (Germany); Schubert, Sophia; Pohlmann, Jan-Dag [Thünen Institute of Fisheries Ecology, Palmaille 9, 22767 Hamburg (Germany); Alaee, Mehran [Water Science and Technology Directorate, Environment Canada, Burlington, Ontario, L7R4A6 Canada (Canada); Wolschke, Hendrik [Helmholtz-Zentrum Geesthacht, Centre for Materials and Coastal Research, Institute of Coastal Research, Department for Environmental Chemistry, Max-Planck-Strasse 1, 21502 Geesthacht (Germany); Leuphana University Lüneburg, Institute of Sustainable and Environmental Chemistry, Scharnhorststraße 1, 21335 Lüneburg (Germany); Hanel, Reinhold [Thünen Institute of Fisheries Ecology, Palmaille 9, 22767 Hamburg (Germany); Ebinghaus, Ralf [Helmholtz-Zentrum Geesthacht, Centre for Materials and Coastal Research, Institute of Coastal Research, Department for Environmental Chemistry, Max-Planck-Strasse 1, 21502 Geesthacht (Germany); Marohn, Lasse [Thünen Institute of Fisheries Ecology, Palmaille 9, 22767 Hamburg (Germany)

    2015-10-15

    The European eel (Anguilla anguilla) is regarded as a critically endangered species. Scientists are in agreement that the “quality of spawners” is a vital factor for the survival of the species. This quality can be impaired by parasites, disease and pollution. Especially endocrine disrupting organic chemicals pose a potential threat to reproduction and development of offspring. To our knowledge, the findings in this publication for the first time describe maternal transfer of contaminants in eels. We analysed the concentrations of in total 53 polybrominated diphenyl ethers (PBDEs) and their halogenated substitutes in muscle, gonads and eggs of artificially matured European eels and in muscle and gonads of untreated European eels that were used for comparison. We found evidence that persistent organic pollutants such as PBDEs, as well as their brominated and chlorinated substitutes are redistributed from muscle tissue to gonads and eggs. Concentrations ranged from 0.001 ng g{sup −1} ww for sum Dechlorane metabolites (DPMA, aCL{sub 10}DP, aCl{sub 11}DP) to 2.1 ng g{sup −1} ww for TBA in eggs, 0.001 ng g{sup −1} ww for Dechlorane metabolites to 9.4 ng g{sup −1} ww for TBA in gonads and 0.002 ng g{sup −1} ww for Dechlorane metabolites to 54 ng g{sup −1} ww for TBA in muscle tissue. Average egg muscle ratios (EMRs) for compounds detectable in artificially matured eels from both Schlei Fjord and Ems River ranged from 0.01 for Dechlorane 602 (DDC-DBF) to 10.4 for PBEB. Strong correlations were found between flame retardant concentrations and lipid content in the analysed tissue types, as well as transfer rates and octanol–water partitioning coefficient, indicating that these parameters were the driving factors for the observed maternal transfer. Furthermore, indications were found, that TBP-DBPE, TBP-AE, BATE and TBA have a significant uptake from the surrounding water, rather than just food and might additionally be formed by metabolism or

  19. Maternal transfer of emerging brominated and chlorinated flame retardants in European eels

    International Nuclear Information System (INIS)

    Sühring, Roxana; Freese, Marko; Schneider, Mandy; Schubert, Sophia; Pohlmann, Jan-Dag; Alaee, Mehran; Wolschke, Hendrik; Hanel, Reinhold; Ebinghaus, Ralf; Marohn, Lasse

    2015-01-01

    The European eel (Anguilla anguilla) is regarded as a critically endangered species. Scientists are in agreement that the “quality of spawners” is a vital factor for the survival of the species. This quality can be impaired by parasites, disease and pollution. Especially endocrine disrupting organic chemicals pose a potential threat to reproduction and development of offspring. To our knowledge, the findings in this publication for the first time describe maternal transfer of contaminants in eels. We analysed the concentrations of in total 53 polybrominated diphenyl ethers (PBDEs) and their halogenated substitutes in muscle, gonads and eggs of artificially matured European eels and in muscle and gonads of untreated European eels that were used for comparison. We found evidence that persistent organic pollutants such as PBDEs, as well as their brominated and chlorinated substitutes are redistributed from muscle tissue to gonads and eggs. Concentrations ranged from 0.001 ng g −1 ww for sum Dechlorane metabolites (DPMA, aCL 10 DP, aCl 11 DP) to 2.1 ng g −1 ww for TBA in eggs, 0.001 ng g −1 ww for Dechlorane metabolites to 9.4 ng g −1 ww for TBA in gonads and 0.002 ng g −1 ww for Dechlorane metabolites to 54 ng g −1 ww for TBA in muscle tissue. Average egg muscle ratios (EMRs) for compounds detectable in artificially matured eels from both Schlei Fjord and Ems River ranged from 0.01 for Dechlorane 602 (DDC-DBF) to 10.4 for PBEB. Strong correlations were found between flame retardant concentrations and lipid content in the analysed tissue types, as well as transfer rates and octanol–water partitioning coefficient, indicating that these parameters were the driving factors for the observed maternal transfer. Furthermore, indications were found, that TBP-DBPE, TBP-AE, BATE and TBA have a significant uptake from the surrounding water, rather than just food and might additionally be formed by metabolism or biotransformation processes. Dechloranes seem to be

  20. Swimming physiology of European silver eels (Anguilla anguilla L.): energetic costs and effects on sexual maturation and reproduction.

    Science.gov (United States)

    Palstra, Arjan P; van den Thillart, Guido E E J M

    2010-09-01

    The European eel migrates 5,000-6,000 km to the Sargasso Sea to reproduce. Because they venture into the ocean in a pre-pubertal state and reproduce after swimming for months, a strong interaction between swimming and sexual maturation is expected. Many swimming trials have been performed in 22 swim tunnels to elucidate their performance and the impact on maturation. European eels are able to swim long distances at a cost of 10-12 mg fat/km which is 4-6 times more efficient than salmonids. The total energy costs of reproduction correspond to 67% of the fat stores. During long distance swimming, the body composition stays the same showing that energy consumption calculations cannot be based on fat alone but need to be compensated for protein oxidation. The optimal swimming speed is 0.61-0.67 m s(-1), which is approximately 60% higher than the generally assumed cruise speed of 0.4 m s(-1) and implies that female eels may reach the Sargasso Sea within 3.5 months instead of the assumed 6 months. Swimming trials showed lipid deposition and oocyte growth, which are the first steps of sexual maturation. To investigate effects of oceanic migration on maturation, we simulated group-wise migration in a large swim-gutter with seawater. These trials showed suppressed gonadotropin expression and vitellogenesis in females, while in contrast continued sexual maturation was observed in silver males. The induction of lipid deposition in the oocytes and the inhibition of vitellogenesis by swimming in females suggest a natural sequence of events quite different from artificial maturation protocols.

  1. Variation in organotin accumulation in relation to the life history in the Japanese eel Anguilla japonica

    Science.gov (United States)

    Ohji, Madoka; Harino, Hiroya; Arai, Takaomi

    2009-08-01

    In order to examine the ecological risks caused by organotin compounds (OTs) in diadromous fish migrating between sea and freshwaters, tributyltin (TBT) and triphenyltin (TPT) compounds and their breakdown products were determined in the catadromous eel Anguilla japonica, which has sea, estuarine and river life histories, collected in Japanese sea, brackish and freshwaters within the same region. Ontogenic changes in otolith strontium (Sr) and calcium (Ca) concentrations were examined along the life history transect to discriminate the migration type. There were generally three different patterns, which were categorized as 'sea eels', 'estuarine eels' and 'river eels' according to the otolith Sr:Ca ratio. The concentrations of TBT in silver eels (mature eels) were significantly higher than that in yellow eels (immature eels), and the percentages of TBT were also higher in silver eels than in yellow eels. A positive correlation was found between TBT concentration and the gonad-somatic index (GSI). It is thus considered that silver eels have a higher risk of contamination by TBT than yellow eels. TBT and TPT concentrations in sea eels were significantly higher than those in river eels, while no significant differences were observed in TBT and TPT concentrations in estuarine eels compared to sea and river eels. These results suggest that sea eels have a higher ecological risk of OT contamination than river eels during their life history, and the risk of OTs in estuarine eels is considered to be intermediate between that of sea and river eels. Positive linear relationships were found between Sr:Ca ratios and the concentrations of TBT and TPT. Therefore, these results suggest that the ecological risk of OTs increase as the sea residence period in the eel becomes longer. TBT and TPT concentrations in sea eels were significantly higher than those in river eels even at the same growth stage. Thus, it is clear that migratory type is the most important factor for OT

  2. Studi Perbandingan Komposisi Asam Lemak Daging Ikan Sidat (Anguilla marmorata (Q. Gaimard Fase Yellow Eel Dari Sungai Palu Dan Danau Poso

    Directory of Open Access Journals (Sweden)

    Jamaluddin Jamaluddin

    2018-04-01

    Full Text Available Ikan sidat (Anguilla marmorata (Q. Gaimard memiliki keunggulan gizi atau nutrisi yang tinggi seperti vitamin A, vitamin B, vitamin C, vitamin D, vitamin E, protein, mineral, dan asam lemak yang baik bagi kesehatan. Penelitian ini bertujuan untuk menentukan kadar asam lemak, dan membandingkan komposisi asam lemak dari ikan sidat fase yellow eel asal sungai Palu dan danau Poso. Penelitian ini menggunakan metode kromatografi gas dengan mengubah ekstrak lemak menjadi metil ester asam lemak. Hasil analisis komposisi asam lemak daging ikan sidat (Anguilla marmorata (Q. Gaimard fase yellow eel asal sungai Palu dan Danau Poso menunjukan kadar asam lemak jenuh masing-masing 2,766g/100g dan 0,275g/100g; asam lemak tak jenuh tunggal 4,029g/100g dan 0,276g/100g; dan asam lemak tak jenuh ganda 0,541g/100g dan 0,102g/100g. Terdapat perbedaan secara statistik (p<0.05 komposisi dan kadar asam lemak antara daging ikan sidat fase yellow eel asal sungai Palu dan danau Poso. Komposisi asam lemak ikan sidat fase yellow eel asal sungai Palu dan danau Poso masing-masing adalah 23 dan 18 jenis. Asam lemak yang ditemukan pada daging ikan sidat sungai Palu dan tidak ditemukan pada ikan sidat danau Poso adalah asam heneikosenoat, asam miristoleat, Cis-10-pentadekanoat, asam gamma linoleat, dan Cis-11,14,17-eikosatrinoat.

  3. Solvent and extraction methods effects on the quality of eel ( Anguilla bicolor ) oil

    International Nuclear Information System (INIS)

    Sasongko, H; Efendi, N R; Farida, Y; Amartiwi, T; Rahmawati, A A; Wicaksono, A; Budihardjo, A; Sugiyarto

    2017-01-01

    Eel ( Anguilla bicolor) is a general fish consumption in many countries, especially Japan, China, Germany, and France. Besides its vitamin rich, eel oil is also known to contain fatty acids that are necessary for pharmaceutical purposes and as food a supplement. This research was aimed to evaluate the quality of eel oil by different solvent and extraction methods. In this study, fresh eels were extracted using maceration and reflux methods.Chloroform was used as the solvent in the maceration while water used in the reflux method. The oil quality was examined based on the Official Methods of Analysis of the Association of Official Analytical Chemist (AOAC).The result showed that the yield of eel oil using maceration method was 5.44% ± 0.64 with a specific gravity of 0.915 g/mL, while reflux method obtained the yield of 5.33 % ± 0.84 and specific gravity of 0.8575 g/mL. The physicochemical parameters of oil quality used in this study were acid, peroxide, saponification, and iodine value. The maceration method obtained the acid value of 17.389 mgKOH/g, the peroxide value of 7.021meqO 2 /kg, the saponification value of 111.16mgKOH/g, and the iodine value of 65.14 WIJS. While the reflux method produced the acid value of 9.116 mgKOH/g, the peroxide value of 6.088 meqO 2 /kg, the saponification value of 70 mgKOH/g, and the iodine value of 87.74 WIJS. (paper)

  4. Surviving in a toxic world: transcriptomics and gene expression profiling in response to environmental pollution in the critically endangered European eel

    Directory of Open Access Journals (Sweden)

    Pujolar Jose

    2012-09-01

    Full Text Available Abstract Background Genomic and transcriptomic approaches have the potential for unveiling the genome-wide response to environmental perturbations. The abundance of the catadromous European eel (Anguilla anguilla stock has been declining since the 1980s probably due to a combination of anthropogenic and climatic factors. In this paper, we explore the transcriptomic dynamics between individuals from high (river Tiber, Italy and low pollution (lake Bolsena, Italy environments, which were measured for 36 PCBs, several organochlorine pesticides and brominated flame retardants and nine metals. Results To this end, we first (i updated the European eel transcriptome using deep sequencing data with a total of 640,040 reads assembled into 44,896 contigs (Eeelbase release 2.0, and (ii developed a transcriptomic platform for global gene expression profiling in the critically endangered European eel of about 15,000 annotated contigs, which was applied to detect differentially expressed genes between polluted sites. Several detoxification genes related to metabolism of pollutants were upregulated in the highly polluted site, including genes that take part in phase I of the xenobiotic metabolism (CYP3A, phase II (glutathione-S-transferase and oxidative stress (glutathione peroxidase. In addition, key genes in the mitochondrial respiratory chain and oxidative phosphorylation were down-regulated at the Tiber site relative to the Bolsena site. Conclusions Together with the induced high expression of detoxification genes, the suggested lowered expression of genes supposedly involved in metabolism suggests that pollution may also be associated with decreased respiratory and energy production.

  5. Proteomic responses of peripheral blood mononuclear cells in the European eel (Anguilla anguilla) after perfluorooctane sulfonate exposure

    Energy Technology Data Exchange (ETDEWEB)

    Roland, Kathleen, E-mail: kathleen.roland@fundp.ac.be [Research Unit in Environmental and Evolutionary Biology (URBE), Narilis (Namur Research Institute for Lifesciences), University of Namur - FUNDP, Rue de Bruxelles 61, B-5000, Namur (Belgium); Kestemont, Patrick; Hénuset, Laurence; Pierrard, Marie-Aline [Research Unit in Environmental and Evolutionary Biology (URBE), Narilis (Namur Research Institute for Lifesciences), University of Namur - FUNDP, Rue de Bruxelles 61, B-5000, Namur (Belgium); Raes, Martine; Dieu, Marc [Research Unit in Cellular Biology (URBC) Narilis (Namur Research Institute for Lifesciences), University of Namur - FUNDP, Rue de Bruxelles 61, B-5000, Namur (Belgium); Silvestre, Frédéric [Research Unit in Environmental and Evolutionary Biology (URBE), Narilis (Namur Research Institute for Lifesciences), University of Namur - FUNDP, Rue de Bruxelles 61, B-5000, Namur (Belgium)

    2013-03-15

    Highlights: ► We have evaluating the toxicity of eel peripheral blood mononuclear cells exposed during 48 h to 10 μg and 1 mg perfluoroctane sulfonate/L. ► After in vitro contaminations, the post-nuclear fraction was isolated and a proteomic analysis using 2D-DIGE was performed. ► 48 different proteins were identified and classified into main functional classes which provide clues on the cellular pathways mainly affected by PFOS. -- Abstract: Since the 1980s, the stocks of European eel have been declining in most of their geographical distribution area. Many factors can be attributed to this decline such as pollution by xenobiotics like perfluorooctane sulfonate (PFOS). This study aimed at evaluating the in vitro toxicity of eel peripheral blood mononuclear cells (PBMC) exposed to PFOS. Exposure time and two concentrations were chosen to avoid cell mortality (48 h exposure at 10 μg PFOS/L and 1 mg PFOS/L). After in vitro contaminations, the post-nuclear fraction was isolated and a proteomic analysis using 2D-DIGE was performed to compare PBMC from the control group with cells exposed to the pollutant. On the 158 spots that were significantly affected by PFOS exposure, a total of 48 different proteins were identified using nano-LCESI-MS/MS and the Peptide and Protein Prophet of Scaffold software. These proteins can be categorized into diverse functional classes, related to cytoskeleton, protein folding, cell signaling, proteolytic pathway and carbohydrate and energy metabolism, which provide clues on the cellular pathways mainly affected by PFOS. Some of the identified proteins are rarely found in other ecotoxicological proteomic studies and could constitute potential biomarkers of exposure to PFOS in fish.

  6. Molecular markers of oocyte differentiation in European eel during hormonally induced oogenesis.

    Science.gov (United States)

    Rojo-Bartolomé, Iratxe; Martínez-Miguel, Leticia; Lafont, Anne-Gaëlle; Vílchez, M Carmen; Asturiano, Juan F; Pérez, Luz; Cancio, Ibon

    2017-09-01

    Reproduction in captivity is a key study issue in Anguilla anguilla as a possible solution for its dwindling population. Understanding the mechanisms controlling the production of ribosomal building blocks during artificially induced oocyte maturation could be particularly interesting. Transcription levels of ribosomal biogenesis associated genes could be used as markers to monitor oogenesis. Eels from the Albufera Lagoon were injected with carp pituitary extract for 15weeks and ovaries in previtellogenic (PV) stage (non-injected), in early-, mid-, late-vitellogenesis (EV, MV, LV), as well as in migratory nucleus stage (MN) were analysed. 5S rRNA and related genes were highly transcribed in ovaries with PV oocytes. As oocytes developed, transcriptional levels of genes related to 5S rRNA production (gtf3a), accumulation (gtf3a, 42sp43) and nucleocytoplasmic transport (rpl5, rpl11) and the 5S/18S rRNA index decreased (PV>EV>MV>LV>MN). On the contrary, 18S rRNA was at its highest at MN stage while ubtf1 in charge of activating RNA-polymerase I and synthesising 18S rRNA behaved as 5S related genes. Individuals that did not respond (NR) to the treatment showed 5S/18S index values similar to PV females, while studied genes showed EV/LV-like transcription levels. Therefore, NR females fail to express the largest rRNAs, which could thus be taken as markers of successful vitellogenesis progression. In conclusion, we have proved that the transcriptional dynamics of ribosomal genes provides useful tools to characterize induced ovarian development in European eels. In the future, such markers should be studied as putative indicators of response to hormonal treatments and of the quality of obtained eel oocytes. Copyright © 2017. Published by Elsevier Inc.

  7. Swimming depth of migrating silver eels Anguilla japonica released at seamounts of the West Mariana Ridge, their estimated spawning sites

    OpenAIRE

    Aoyama, J.; Hissmann, Karen; Yoshinaga, T.; Sasai, S.; Uto, T.; Ueda, H.

    1999-01-01

    Five hormone-treated female Japanese silver eels Anguilla japonica were tagged with ultrasonic transmitters and released by submersible in the West Pacific at seamounts of the West Mariana Ridge, their supposed spawning grounds. Four eels were tracked for 60 to 423 min in the vicinity of the seamounts. They did not settle at the seamounts but swam at a mean speed of 0.37 m s-1 into open water above deep ground. Their mean swimming depth ranged from 81 to 172 m. Experiments suggest that pre-ma...

  8. Effects of feed composition on life history developments in feed intake, metabolism, growth and body composition of European eel, Anguilla anguilla

    NARCIS (Netherlands)

    Heinsbroek, L.T.N.; Hooff, P.L.A.; Swinkels, W.; Tanck, M.W.T.; Schrama, J.W.; Verreth, J.A.J.

    2007-01-01

    To examine the effect of feed composition on changes in feed intake and subsequent feed utilization with age, five populations of European eel, with an average initial body weight of 5 g each fed a different diet, were monitored for 302 d. The five feeds differed in their content of crude protein

  9. Direct calorimetry of free-moving eels with manipulated thyroid status

    Science.gov (United States)

    van Ginneken, Vincent; Ballieux, Bart; Antonissen, Erik; van der Linden, Rob; Gluvers, Ab; van den Thillart, Guido

    2007-02-01

    In birds and mammals, the thyroid gland secretes the iodothyronine hormones of which tetraiodothyronine (T4) is less active than triiodothyronine (T3). The action of T3 and T4 is calorigenic and is involved in the control of metabolic rate. Across all vertebrates, thyroid hormones also play a major role in differentiation, development and growth. Although the fish thyroidal system has been researched extensively, its role in thermogenesis is unclear. In this study, we measured overall heat production to an accuracy of 0.1 mW by direct calorimetry in a free-moving European eel ( Anguilla anguilla L.) with different thyroid status. Hyperthyroidism was induced by injection of T3 and T4, and hypothyroidism was induced with phenylthiourea. The results show for the first time at the organismal level, using direct calorimetry, that neither overall heat production nor overall oxygen consumption in eels is affected by hyperthyroidism. Therefore, we conclude that the thermogenic metabolism-stimulating effect of thyroid hormones (TH) is not present with a cold-blooded fish species like the European eel. This supports the concept that TH does not stimulate thermogenesis in poikilothermic species.

  10. Differential expression of gonadotropin and estrogen receptors and oocyte cytology during follicular maturation associated with egg viability in European eel (Anguilla anguilla)

    DEFF Research Database (Denmark)

    da Silva, Filipa F. G.; Tveiten, Helge; Maugars, Gersende

    2018-01-01

    In captivity, oogenesis and ovarian follicle maturation in European eel can be induced experimentally using hormonal therapy. The follicle's ability to respond effectively to the induction of maturation and ovulation, resulting in viable eggs, depends on the oocyte stage at the time of induction....

  11. Presence of viruses in wild eels Anguilla anguilla L, from the Albufera Lake (Spain).

    Science.gov (United States)

    Bandín, I; Souto, S; Cutrín, J M; López-Vázquez, C; Olveira, J G; Esteve, C; Alcaide, E; Dopazo, C P

    2014-07-01

    A virological analysis was conducted on wild eels from the Albufera Lake (Spain). A total of 179 individuals at different growth stages were collected in two different surveys (2004 and 2008). Presence of anguillid herpesvirus (AngHV-1), aquabirnavirus and betanodavirus was confirmed by PCR procedures in both surveys, although the number of detections was clearly higher in 2008 (83% of the eels analysed resulted positive for virus presence). AngHV-1 was the viral agent most frequently detected, followed by aquabirnaviruses. Betanodaviruses were detected by the first time in wild eels, and although the detections were only made by nested PCR, high percentage of positives were achieved. In addition, in 2008, seven aquabirnaviruses were isolated. Phylogenetic analysis performed using partial sequences of both genomic segments of aquabirnaviruses indicated that the seven isolates could be typed as WB (genogroup I) on the basis of segment A sequences, but when segment B was used six of them clustered with C1 strain (genogroup V) and one was typed as Ab (genogroup II). These results indicate natural reassortment between different strains of aquabirnaviruses in the eels. Although betanodaviruses were not isolated in cell culture, the analysis of the sequence of the nested PCR product indicated that they clustered with SJNNV genotype. The diversity of viral agents and the high level of viral detections suggest that viral infections may play a more prominent role in the decline of the European eel than initially thought. © 2014 John Wiley & Sons Ltd.

  12. Eel Kisspeptins: Identification, Functional Activity, and Inhibition on both Pituitary LH and GnRH Receptor Expression

    Directory of Open Access Journals (Sweden)

    Jérémy Pasquier

    2018-01-01

    Full Text Available The European eel (Anguilla anguilla presents a blockade of sexual maturation at a prepubertal stage due to a deficient production of gonadotropins. We previously initiated, in the eel, the investigation of the kisspeptin system, one of the major gatekeepers of puberty in mammals, and we predicted the sequence of two Kiss genes. In the present study, we cloned and sequenced Kiss1 and Kiss2 cDNAs from the eel brain. The tissue distributions of Kiss1 and Kiss2 transcripts, as investigated by quantitative real-time PCR, showed that both genes are primarily expressed in the eel brain and pituitary. The two 10-residue long sequences characteristic of kisspeptin, eel Kp1(10 and Kp2(10, as well as two longer sequences, predicted as mature peptides, eel Kp1(15 and Kp2(12, were synthesized and functionally analyzed. Using rat Kiss1 receptor-transfected Chinese hamster ovary cells, we found that the four synthesized eel peptides were able to induce [Ca2+]i responses, indicating their ability to bind mammalian KissR-1 and to activate second messenger pathways. In primary culture of eel pituitary cells, all four peptides were able to specifically and dose-dependently inhibit lhβ expression, without any effect on fshβ, confirming our previous data with heterologous kisspeptins. Furthermore, in this eel in vitro system, all four peptides inhibited the expression of the type 2 GnRH receptor (gnrh-r2. Our data revealed a dual inhibitory effect of homologous kisspeptins on both pituitary lhβ and gnrh-r2 expression in the European eel.

  13. Metal and metallothionein content in tissues from wild and farmed Anguilla anguilla at commercial size.

    Science.gov (United States)

    Ureña, R; Peri, S; del Ramo, J; Torreblanca, A

    2007-05-01

    Metallothionein and metal content (Cd, Zn, Hg, Cu, Fe, Pb and Mn) were determined in various organs of commercially available eel (Anguilla anguilla) of similar size obtained from a local farm and from The Albufera Lake in Valencia (Spain). Farmed fish showed statistically significant higher Cd concentrations in liver and kidney whereas wild individuals had higher levels of Pb in blood and Zn in kidney. Significant positive correlations were found between metallothionein and Cd in kidney of farmed eel and between metallothionein and Cu in liver of wild ones. No statistically significant differences were found between the two populations in the concentration of any of the metals analyzed in muscle and in all instances these levels were lower than the limits established by the Spanish legislation for fish destined for human consumption.

  14. Observations on nematodes from the Indonesian shortfin eel Anguilla bicolor bicolor McClelland in India, including a revalidation of Heliconema ahiri Karve, 1941 (Physalopteridae)

    Czech Academy of Sciences Publication Activity Database

    Moravec, František; Sheeba, S.; Kumar, A. B.

    2013-01-01

    Roč. 58, č. 4 (2013), s. 496-503 ISSN 1230-2821 R&D Projects: GA ČR GBP505/12/G112 Institutional support: RVO:60077344 Keywords : Parasitic nematode * Heliconema * Procamallanus * Spirocamallanus * freshwater eel * Anguilla bicolor bicolor * Kerala * India Subject RIV: EA - Cell Biology Impact factor: 0.965, year: 2013

  15. Heliconema anguillae Yamaguti, 1935, a physalopterid nematode found in Japanese eels: taxonomic resurrection with a note on the third-stage larva from intertidal crabs in western Japan.

    Science.gov (United States)

    Katahira, Hirotaka; Nagasawa, Kazuya

    2015-01-01

    A parasitic nematode from the stomach of Japanese eel Anguilla japonica Temminck et Schlegel in western Japan, previously identified as Heliconema longissimum (Ortlepp, 1922), was morphologically re-examined and compared with the previous descriptions. In addition, the third-stage larva of this nematode is described, based on the specimens of encapsuled larvae found in musculature of two crabs, Hemigrapsus sp. and Perisesarma bidens (De Haan), caught from the upper-intertidal zone of the same locality. As a result of the morphological observation, seven pairs of postcloacal papillae in adult males are confirmed. This matches with the character of H. longissimum, but the shape of the fifth postcloacal papillae differs between the present material and H. longissimum; the former possesses pedunculate papillae in the fifth pair whereas the latter has sessile papillae. Since the pedunculate papillae can be found in the original description and the syntype specimens of H. anguillae Yamaguti, 1935 that has been synonymised with H. longissimum, we thus here resurrect H. anguillae as an accepted species. For the life-cycle of the present nematode, littoral crabs, including the two infected species, are likely to be the source of infections for Japanese eels, acting as intermediate hosts.

  16. Detection of Herpesvirus anguillae (AngHV-1) in European eel Anguilla anguilla (L.) originating from northern Poland-assessment of suitability of selected diagnostic methods.

    Science.gov (United States)

    Nguyen, Tuan Thuc; Jin, Yeonhwa; Kiełpińska, Jolanta; Bergmann, Sven M; Lenk, Matthias; Panicz, Remigiusz

    2017-11-01

    The Community Action Plan requests EU member states to implement measures that ensure the recovery of the severely depleted European eel stocks. One of the main threats is posed by Anguillid herpesvirus 1 (AngHV-1) leading to increased mortality in both wild and farmed eels. Following recommendations of the OIE to minimize the risk of obtaining false-negative results, the main aim of the study was to optimize diagnostic methods for AngHV-1 detection using conventional PCR, nested PCR and in situ hybridization assay. While 53.3% of the individual organ samples were tested positive for AngHV-1 by PCR, the additional virus analysis via nested PCR revealed that the actual prevalence was 93.3%. In the cell cultivation passages, a cytopathic effect was hardly found in the first two rounds. In the third passage onto cell cultures, a lytic CPE was detected. The identification and confirmation of the viruses obtained from cell cultures as well as directly from the organ tissues were proceeded by PCR, nested PCR and sequencing of the PCR products. While no positive signal was detectable in the first round by PCR using samples from the third cell culture passages, the nested PCR provided weak but visible positive signals. © 2017 John Wiley & Sons Ltd.

  17. A quick method for species identification of Japanese eel (Anguilla japonica) using real-time PCR: an onboard application for use during sampling surveys.

    Science.gov (United States)

    Watanabe, Shun; Minegishi, Yuki; Yoshinaga, Tatsuki; Aoyama, Jun; Tsukamoto, Katsumi

    2004-01-01

    To compensate for the limited number of morphological characteristics of fish eggs and larvae, we established a convenient and robust method of species identification for eggs of the Japanese eel (Anguilla japonica) using a real-time polymerase chain reaction (PCR) that can be performed onboard research ships at sea. A total of about 1.2 kbp of the mitochondrial 16S ribosomal RNA gene sequences from all species of Anguilla and 3 other anguilliform species were compared to design specific primer pairs and a probe for A. japonica. This real-time PCR amplification was conducted for a total of 44 specimens including A. japonica, A. marmorata, A. bicolor pacifica, and 6 other anguilliform species. Immediate PCR amplification was only observed in A. japonica. We then tested this method under onboard conditions and obtained the same result as had been produced in the laboratory. These results suggest that real-time PCR can be a powerful tool for detecting Japanese eel eggs and newly hatched larvae immediately after onboard sampling during research cruises and will allow targeted sampling efforts to occur rapidly in response to any positive onboard identification of the eggs and larvae of this species.

  18. Reproduction of European Eel in Aquaculture (REEL)

    DEFF Research Database (Denmark)

    Tomkiewicz, Jonna; Tybjerg, Lars; Støttrup, Josianne

    for the development of methods to reproduce European eel in aquaculture. Two major projects: Artificial Reproduction of Eels II and III (ROE II and III) succeeded during 2005-2008 to produce viable eggs and larvae that lived up to 12 days. The larvae thereby accomplished the yolk-sac stage and became ready to start...... feeding. The results were in particular promising because they evidenced that methods successfully applied to Japanese eel has a potential for application also to the European eel. ROE II and III were supported by the Ministry of Food, Agriculture and Fisheries and the European Commission through...... the Financial Instrument for Fisheries Guidance (FIFG) and the Danish Food Research Program 2006, respectively. Results: The REEL project accomplished through three series of experiments to consolidate previous results. The longevity of larvae was extended from 12 to 20 days after hatch in first feeding...

  19. Qualitative assessment of the diet of European eel larvae in the Sargasso Sea resolved by DNA barcoding

    DEFF Research Database (Denmark)

    Riemann, L.; Alfredsson, H.; Hansen, Michael Møller

    2010-01-01

    , the Sargasso Sea is oligotrophic, with generally low plankton biomass, and the feeding biology of eel larvae has so far remained a mystery, hampering understanding of this peculiar life history. DNA barcoding of gut contents of 61 genetically identified A. anguilla larvae caught in the Sargasso Sea showed...

  20. Occurrence of perfluorooctanesulfonate and perfluorooctanoic acid and histopathology in eels from north Italian waters.

    Science.gov (United States)

    Giari, Luisa; Guerranti, Cristiana; Perra, Guido; Lanzoni, Mattia; Fano, Elisa Anna; Castaldelli, Giuseppe

    2015-01-01

    A perfluorinated alkylated substances (PFAS) biomonitoring study was conducted in European eel (Anguilla anguilla) in Italy for the first time. Perfluorooctanesulfonate (PFOS) and perfluorooctanoic acid (PFOA) concentrations were assessed in the organs of 35 wild eels from two locations, the highly impacted Po River and the Comacchio Lagoon along the north-western Adriatic coast. PFAS were extracted by ion-pairing liquid extraction procedure and measured using high performance liquid chromatography with electrospray ionization tandem mass spectrometry. There were no significant differences in mean PFAS concentrations (p>0.05) between samples from the two sites. PFOS and PFOA were detectable (>0.4ngg(-1) wet weight, w.w) in 73% and 31% of the total samples, respectively. PFOS concentrations ranged from PFAS levels were observed in blood and the lowest in muscle. Histology showed macrophage aggregates and hepatocytic vacuolation in some liver samples. No tissue anomalies were seen in the gonads, suggesting no reproductive impairment. The PFAS contamination levels observed were comparable to, or lower than, those reported in fish in other European countries, seeming to indicate that PFAS pollution of the study area is not remarkable. Copyright © 2014 Elsevier Ltd. All rights reserved.

  1. ANGUILLICOLOSIS AMONG SILVER EELS: A 2-YEAR SURVEY IN 4 HABITATS FROM CAMARGUE (RHÔNE DELTA, SOUTH OF FRANCE

    Directory of Open Access Journals (Sweden)

    LEFEBVRE F.

    2003-07-01

    Full Text Available We have investigated the spread of the infection by Anguillicola crassus among the silver phase of the European eel Anguilla anguilla in the Rhône delta. We reported values of prevalence, mean intensity and abundance in 4 habitats and we revealed negative relationships between these parasitic parameters and values of salinity (prevalence from 52 % in brackish waters to 77 % in fresh waters. We have also assessed the health state of the infected organ, i.e. the swimbladder. This may be a way to check the parasitic history of individuals throughout their continental phase. In silver eels free from parasites, the proportion of past infected individuals was ranged between 40 % and 78 %. When adding individuals showing worms at the autopsy with those showing signs of past infection(s, we highlighted a great proportion of silver eels really affected by anguillicolosis (from 71 % to 95 %, with a negative relationship in respect to salinity values. So, considering the spread of the infection, and its potential impairments on body condition, gas exchanges, hydrostatic abilities, etc., one may legitimately question about the proportion of silver eels that may get back to the Sargasso sea and reproduce.

  2. Data on the characterization of follicle-stimulating hormone monoclonal antibodies and localization in Japanese eel pituitary

    Directory of Open Access Journals (Sweden)

    Dae-Jung Kim

    2016-09-01

    Full Text Available Monoclonal antibodies were generated against recombinant follicle-stimulating hormone (rec-FSH from Japanese eel Anguilla japonica; rec-FSH was produced in Escherichia coli and purified using Ni-NTA Sepharose column chromatography.In support of our recent publication, ''Production and characterization of monoclonal antibodies against recombinant tethered follicle-stimulating hormone from Japanese eel Anguilla japonica'' [1], it was important to characterize the specificity of eel follicle-stimulating hormone antibodies. Here, the production and ELISA system of these monoclonal antibodies are presented. The affinity-purified monoclonal antibodies specifically detected eel rec-FSH in ELISA and on western blots of rec-FSH produced from CHO cells. Immunohistochemical analysis revealed that FSH staining was specifically localized in the eel pituitary. Keywords: Japanese eel, FSH, Monoclonal Antibody

  3. Endocrine and metabolic responses of Anguilla anguilla L. caged in a freshwater-wetland (Pateira de Fermentelos-Portugal)

    Energy Technology Data Exchange (ETDEWEB)

    Teles, M. [Biology Department, Aveiro University, 3810-193 Aveiro (Portugal)]. E-mail: mteles@bio.ua.pt; Pacheco, M. [Biology Department, Aveiro University, 3810-193 Aveiro (Portugal)]. E-mail: mpacheco@bio.ua.pt; Santos, M.A. [Biology Department, Aveiro University, 3810-193 Aveiro (Portugal)]. E-mail: monteiro@bio.ua.pt

    2007-01-01

    The present short-term in situ study was carried out in a freshwater-wetland - Pateira de Fermentelos - considered an enlargement of Certima River, in the centre of Portugal. This ecosystem is an important fishing and recreation place, receiving effluents from different origins namely, electroplating industrial effluents containing heavy metals, domestic wastes, as well as pesticides and fertilizers resulting from agriculture activities. The aim of the present research work was to monitor the effects induced by the contaminants present in Pateira de Fermentelos water, using Anguilla anguilla L. (European eel) as a bioindicator. The eels were caged for 48 h at four Pateira de Fermentelos sites, differing in their distances to the main known pollution source (Certima River): A (close to the lagoon entrance), B, C and D (the farthest from the Certima River). A reference site was selected near the Certima river spring. The following parameters were measured: liver ethoxyresorufin-O-deethylase (EROD) and alanine transaminase (ALT) activities, plasma levels of cortisol, 17{beta}-estradiol (E{sub 2}), thyroid-stimulating-hormone (TSH), free thyroxine (T4), free triiodothyronine (T3), as well as glucose and lactate. The erythrocytic nuclear abnormalities (ENA) frequency was also scored as a genotoxicity indicator. The results revealed increased plasma cortisol and glucose concentrations at all exposure sites, displaying a similar response pattern. Plasma T3 showed a significant decrease only at site A when compared to reference site, whereas plasma E{sub 2} increased at sites B and D when compared to all the other sites, including reference site. The present results indicate the Pateira de Fermentelos water contamination, demonstrating the usefulness of the adopted strategy.

  4. Thirty year monitoring of PCBs, organochlorine pesticides and tetrabromodiphenylether in eel from The Netherlands

    NARCIS (Netherlands)

    Boer, de J.; Dao, Q.T.; Leeuwen, van P.W.; Kotterman, M.J.J.; Schobben, J.H.M.

    2010-01-01

    Because of their excellent properties as a biomonitor, yellow eels (Anguilla anguilla) have been used for time-trend monitoring of polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs) and tetrabrominated diphenylether (tetra-BDE). The program has now lasted for thirty years and has

  5. A novel recombinant bivalent outer membrane protein of Vibrio vulnificus and Aeromonas hydrophila as a vaccine antigen of American eel (Anguilla rostrata).

    Science.gov (United States)

    SongLin, Guo; PanPan, Lu; JianJun, Feng; JinPing, Zhao; Peng, Lin; LiHua, Duan

    2015-04-01

    The immogenicity of a novel vaccine antigen was evaluated after immunized American eels (Anguilla rostrata) with a recombinant bivalent expressed outer membrane protein (OMP) of Vibrio vulnificus and Aeromonas hydrophila. Three groups of eels were intraperitoneal (i.p) injected with phosphate-buffered saline (PBS group), formaline-killed-whole-cell (FKC) of A. hydrophila and V. vulnificus (FKC group) or the bivalent OMP (OMP group). On 14, 21, 28 and 42 days post-vaccination respectively, proliferation of the whole blood cells, titers of specific antibody and lysozyme activities of experimental eels were detected. On 28 day post-vaccination, eels from three groups were challenged by i.p injection of live A. hydrophila or V. vulnificus. The results showed that, compared with the PBS group, proliferation of whole blood cells in OMP group was significant enhanced on 28 days, and the serum titers of anti-A.hydrophila and anti-V. vulnificus antibody in eels of FKC and OMP group were significant increased on 14, 21 and 28d. Lysozyme Activities in serum, skin mucus, liver and kidney were significant changed between the three groups. Relative Percent Survival (RPS) after challenged A. hydrophila in KFC vs. PBS group and OMP vs. PBS group were 62.5% and 50% respectively, and the RPS challenged V. vulnificus in FKC and OMP vs. PBS group were 37.5% and 50% respectively. These results suggest that American eels immunized with the bivalent OMP would positively affect specific as well as non-specific immune parameters and protect against infection by the two pathogens in fresh water farming. Copyright © 2015 Elsevier Ltd. All rights reserved.

  6. Adenosine/nitric oxide crosstalk in the branchial circulation of Squalus acanthias and Anguilla anguilla.

    Science.gov (United States)

    Pellegrino, D; Tota, B; Randall, D J

    2005-10-01

    The potent vasomodulator adenosine (AD), thanks to the interaction with by A(1) and A(2) receptors, dilates systemic, coronary and cerebral vasculatures but exert a constrictor action in several vessels of respiratory organs. Recent investigations suggest that nitric oxide (NO) contributes to AD effects. In fish, both NO and AD induce atypical effects compared to mammals. Since there is very little information on the role of NO and its involvement in mediating the actions of AD in fish, we have analysed this question in the branchial vasculature of the elasmobranch Squalus acanthias and the teleost Anguilla anguilla using an isolated perfused head and a branchial basket preparation, respectively. In both dogfish and eel, AD dose-response curves showed a biphasic effect: vasoconstriction (pico to nanomolar range) and vasodilation (micromolar range). Both effects were abolished by the classic xanthine inhibitor theophylline (Theo) and also by specific antagonists of A(1) and A(2) receptor subtypes. To analyse the involvement of the NO/cGMP system in the AD responses, we tested a NOS inhibitor, l-NIO, and a specific soluble guanylate cyclase (sGC) blocker, ODQ. In both dogfish and eel preparations l-NIO abrogated all vasomotor effects of AD, whereas ODQ blocked the AD-mediated vasoconstriction without affecting the vasorelaxant response. This indicates that only AD-induced vasoconstriction is mediated by a NO-cGMP-dependent mechanism. By using the NO donor SIN-1, we showed a dose-dependent vasoconstrictory effect which was completely blocked by ODQ. These results provide compelling evidence that the vasoactive role of AD in the branchial circulation of S. acanthias and A. anguilla involves a NO signalling.

  7. Myo-inositol phosphate synthase expression in the European eel (Anguilla anguilla) and Nile tilapia (Oreochromis niloticus): effect of seawater acclimation.

    Science.gov (United States)

    Kalujnaia, Svetlana; Hazon, Neil; Cramb, Gordon

    2016-08-01

    A single MIPS gene (Isyna1/Ino1) exists in eel and tilapia genomes with a single myo-d-inositol 3-phosphate synthase (MIPS) transcript identified in all eel tissues, although two MIPS spliced variants [termed MIPS(s) and MIPS(l)] are found in all tilapia tissues. The larger tilapia transcript [MIPS(l)] results from the inclusion of the 87-nucleotide intron between exons 5 and 6 in the genomic sequence. In most tilapia tissues, the MIPS(s) transcript exhibits much higher abundance (generally >10-fold) with the exception of white skeletal muscle and oocytes, in which the MIPS(l) transcript predominates. SW acclimation resulted in large (6- to 32-fold) increases in mRNA expression for both MIPS(s) and MIPS(l) in all tilapia tissues tested, whereas in the eel, changes in expression were limited to a more modest 2.5-fold increase and only in the kidney. Western blots identified a number of species- and tissue-specific immunoreactive MIPS proteins ranging from 40 to 67 kDa molecular weight. SW acclimation failed to affect the abundance of any immunoreactive protein in any tissue tested from the eel. However, a major 67-kDa immunoreactive protein (presumed to be MIPS) found in tilapia tissues exhibited 11- and 54-fold increases in expression in gill and fin samples from SW-acclimated fish. Immunohistochemical investigations revealed specific immunoreactivity in the gill, fin, skin, and intestine taken from only SW-acclimated tilapia. Immunofluorescence indicated that MIPS was expressed within gill chondrocytes and epithelial cells of the primary filaments, basal epithelial cell layers of the skin and fin, the cytosol of columnar intestinal epithelial and mucous cells, as well as unknown entero-endocrine-like cells. Copyright © 2016 the American Physiological Society.

  8. Gill lipid metabolism and unidirectional Na+ flux in the European eel (Anguilla anguilla) after transfer to dilute media

    DEFF Research Database (Denmark)

    Hansen, H.J.M.; Grosell, M.; Rosenkilde, P.

    1999-01-01

    The present study investigated the mechanism involved when fish tighten their gill membrane after transfer to dilute media. Ten individually assayed eels adapted to fresh water (EW) and labelled with radioactive Na-22 in the plasma showed mean exchange rates in equilibrium with ambient radioactive...... Na-24 in FW at 70 mu mol kg(-1) h(-1). Just after transfer to demineralized water (DW), the mean Na+ release rate went up to 120 mu molkg(-1) h(-1); after 24 h in DW it came down again and levelled off at 40 mu mol kg(-1) h(-1) during a period of up to 2 weeks. During the same period the mean Na......% of the total C-14-activity incorporated into gill lipids as (C-14) wax alcohols (WA; octadecanol and eicosanol). This percentage went up to 50% shortly after transfer to DW and came down again to about 20% after 2 weeks in DW. Single eels labelled with Na-22 in the plasma showed a statistically significant...

  9. Umur glas eel (Anguilla spp. yang masuk muara Sungai Progo Yogyakarta

    Directory of Open Access Journals (Sweden)

    Agung Budiharjo

    2017-03-01

    Full Text Available The leptocephalus drift with sea currents and moving from spawning area into coastal area near mouth of Progo River. In thecoastal area, leptocephalus metamorfosed into glass eel, after that glass eel migrated to river. The aims of this research were to estimate glass eels age and predict hatching dates. Glass eels sampled on new moon during Februari 2007-Mei 2009 at mouth of Progo River.Glass eel ages estimated using their otolith micro structure. Hatching dates predicted with back calculation of glass eels age. We collected 1.082 glass eels. The ages of glass eel at recruit ranged from 58 to 190 days, and divided into 5 age groups. Glass eels are migrated to river hatched on a "new moon" from July to January. Glass eels are migrated to river during October-January hatched during July-October. Glass eels are migrated to river during February-Juny hatched during November-January.

  10. Hydrographic features of anguillid spawning areas: Potential signposts for migrating eels

    DEFF Research Database (Denmark)

    Schabetsberger, Robert; Miller, Michael J.; Dall'Olmo, Giorgio

    2016-01-01

    Catadromous anguillid eels (genus Anguilla) migrate from their freshwater or estuarine habitats to marine spawning areas. Evidence from satellite tagging studies indicates that tropical and temperate eel species exhibit pronounced diel vertical migrations, from between 150-300 m nighttime depths...... to 600-800 m during the day. Collections of eggs and larvae of Japanese eels A. japonica suggest they may spawn at these upper nighttime migration depths. How anguillid eels navigate through the ocean and find their spawning areas remains unknown; thus, this study describes the salinity, temperature...

  11. Are persistent organic pollutants and metals in eel muscle predictive for the ecological water quality?

    International Nuclear Information System (INIS)

    Van Ael, Evy; Belpaire, Claude; Breine, Jan; Geeraerts, Caroline; Van Thuyne, Gerlinde; Eulaers, Igor; Blust, Ronny; Bervoets, Lieven

    2014-01-01

    Relationships between the presence of PCBs, OCPs and metals in aquatic ecosystems and the ecological water quality were investigated by combining datasets of long-term monitoring of chemicals in European eel (Anguilla anguilla, N = 1156) in Flanders (Belgium) and the Ecological Quality Ratio (EQR), based on the assessment of fish assemblages at 185 locations. For most pollutants, EQR scores were lower when pollutant levels were higher. Threshold concentrations for a good quality could be formulated for PCB's, most metals and OCPs. Mixed models suggested that the ecological water quality was significantly correlated with the presence of PCBs. However, the low R 2 indicates that other environmental pressures may significantly influence the biotic integrity of fish communities. Empirical data and their analyses are essential to enable defining threshold values of bioaccumulated levels to allow better protection of the aquatic environment and its biota through associated food webs as demanded by the Water Framework Directive. -- Highlights: • Relation between ecological water quality and pollution load in eel was studied. • Ecological Quality Ratio was lower when concentrations in eel were higher. • Threshold levels for a good quality status were formulated. • EQS possibly too stringent for Hg and too high for Cd and Pb compared to our results. • Mixed models suggest a significant influence of PCBs on ecological water quality. -- The ecological water quality, as reflected in the biotic integrity of fish communities, is lower when concentrations of PCBs, OCPs and metals in locally sampled eels are higher

  12. Using a novel "Integrated Biomarker Proteomic" index to assess the effects of freshwater pollutants in European eel peripheral blood mononuclear cells.

    Science.gov (United States)

    Roland, Kathleen; Kestemont, Patrick; Dieu, Marc; Raes, Martine; Silvestre, Frédéric

    2016-03-30

    Using proteomic data as biomarkers of environmental pollution has the potential to be of a great interest in ecological risk assessment as they constitute early warning indicators of ecologically relevant effects on biological systems. To develop such specific and sensitive biomarkers, the use of a set of proteins is required and the identification of protein expression signatures (PES) may reflect the exposure to specific classes of pollutants. Using 2D-DIGE (Differential in Gel Electrophoresis) methodology, this study aimed at identifying specific PES on European eel (Anguilla anguilla) peripheral blood mononuclear cells (PBMC) after 48 h in vitro exposure to two sublethal concentrations of dichlorodiphenyltrichloroethane (p,p'-DDT) (10 μg/L and 1mg/L) or cadmium (Cd) (1 μg/L and 100 μg/L). The present results have been supplemented with data of a first in vitro study on cells exposed to perfluorooctane sulfonate (PFOS) (10 μg/L and 1mg/L). A total of thirty-four protein spots, belonging to 18 different identified proteins found in all conditions, have been selected as possible biomarkers to develop a synthetic Integrated Biomarker Proteomic (IBP) index. IBP follows a dose-response relationship with higher values at the highest tested concentration for each pollutant (Cd: 9.96; DDT: 7.44; PFOS: 7.94) compared to the lowest tested concentration (Cd: 3.81; DDT: 2.91; PFOS: 2.06). In a second step, star plot graphs have been applied to proteomic data in order to allow visual integration of a set of early warning responses measured with protein biomarkers. Such star plots permit to discriminate the type of pollutant inducing a proteomic response. We conclude that using IBP is relevant in environmental risk assessment, giving to this index the potential to be applied as a global index of proteome alteration in endangered species such as the European eel. In this study, 34 protein spots have been selected as possible biomarkers to develop a synthetic Integrated

  13. Biomonitoring of aquatic pollution with feral eel (Anguilla anguilla). II. Biomarkers: pollution-induced biochemical responses.

    NARCIS (Netherlands)

    van der Oost, R.; Goksøyr, A.; Celander, M.; Heida, H.; Vermeulen, N.P.E.

    1996-01-01

    The primary aim of this study was to select a set of relevant biomarkers in feral eel for the biological assessment of inland water pollution. A suite of biochemical parameters in eel (hepatic biotransformation enzymes and cofactors, antioxidant enzymes, PAH metabolites, DNA adducts, serum

  14. Nematode eel parasite found inside acanthocephalan cysts--a "Trojan horse" strategy?

    Science.gov (United States)

    Emde, Sebastian; Rueckert, Sonja; Kochmann, Judith; Knopf, Klaus; Sures, Bernd; Klimpel, Sven

    2014-11-18

    The invasive eel parasite Anguillicoloides crassus (syn. Anguillicola crassus) is considered one of the major causes for the decline of the European eel (Anguilla anguilla) panmictic population. It impairs the swim bladder function and reduces swimming performance of its host. The life cycle of this parasite involves different intermediate and paratenic hosts. Despite an efficient immune system of the paratenic fish hosts acting against infections with A. crassus, levels of parasitized eels remain high in European river systems. Recently, the round goby Neogobius melanostomus (Gobiidae) has become dominant in many rivers in Europe and is still spreading at a rapid pace. This highly invasive species might potentially act as an important, so far neglected paratenic fish host for A. crassus. Based on own observations and earlier single sightings of A. crassus in N. melanostomus, 60 fresh individuals of N. melanostomus were caught in the Rhine River and examined to assess the infection levels with metazoan parasites, especially A. crassus. Glycerin preparations were used for parasite identification. The parasite most frequently found in N. melanostomus was the acanthocephalan Pomphorhynchus sp. (subadult stage) which occurred mainly encysted in the mesenteries and liver. Every third gobiid (P = 31.7%) was infected by A. crassus larvae (L3) which exclusively occurred inside the acanthocephalan cysts. No intact or degenerated larvae of A. crassus were detected elsewhere in the goby, neither in the body cavity and mesenteries nor in other organs. Affected cysts contained the acanthocephalan larvae and 1-12 (mI =3) living A. crassus larvae. Additionally, encysted larvae of the nematode Raphidascaris acus were detected in the gobies, but only in the body cavity and not inside the acanthocephalan cysts. Based on our observations, we suggest that A. crassus might actively bypass the immune response of N. melanostomus by invading the cysts of acanthocephalan parasites of the

  15. Oceanic migration behaviour of tropical Pacific eels from Vanuatu

    DEFF Research Database (Denmark)

    Schabetsberger, R; Økland, F; Aarestrup, K

    2013-01-01

    Information on oceanic migrations and spawning areas of tropical Pacific freshwater eels (genus Anguilla) is very limited. Lake Letas and its single outflowing river, Mbe Solomul on Gaua Island, Vanuatu, were surveyed for large migrating individuals. Twenty-four Anguilla marmorata (87 to 142 cm),...... impact of the lunar cycle on the upper limit of migration depths was found in A. marmorata (full moon: 230 m, new moon: 170 m). These behaviours may be explained as a trade-off between predator avoidance and the necessity to maintain a sufficiently high metabolism for migration....

  16. THE CONTRIBUTION OF SPRINGTIME AND AUTUMN GLASS EELS (ANGUILLA ANGUILLA TO STOCK : RESULTS BASED ON OTOLITH MORPHOMETRY.

    Directory of Open Access Journals (Sweden)

    BRIAND C.

    2003-07-01

    Full Text Available A double mark, called a transition ring, or elver mark, was identifiable in light microscopy on otoliths of young yellow eels. In the Vilaine watershed, the radius of this mark decreased from 178 μm in yellow eels corresponding to glass eels arriving in autumn 1997 to 163 μm in yellow eels arriving in spring 1998. The mean transition ring radius of the freshwater eel population in the Vilaine river had an intermediate value between spring and autumn recruits. This implies that it consisted of a mixture of spring and autumn recruits. In the Vilaine estuary and the Frémur populations, the mean radius of the transition rings was close to the autumn one. The springtime recruits formed 68 % of freshwater and 15 % of estuarine population in the Vilaine for the 1998 cohort. This result was in sharp contrast with the available assessments of recruitment, which both in estuary and in the fluvial part of the watershed, were dominated by spring recruits. This contrast is possibly the consequence of density-dependent mortality, which would have been particularly important in springtime for glass eels whose migration was inhibited by the dam.

  17. Hypotonicity induced K+ and anion conductive pathways activation in eel intestinal epithelium

    DEFF Research Database (Denmark)

    Lionetto, M G; Giordano, M E; De Nuccio, F

    2005-01-01

    , the activation of 'emergency' systems of rapid cell volume regulation is fundamental in their physiology. The aim of the present work was to study the physiological response to hypotonic stress in a salt-transporting epithelium, the intestine of the euryhaline teleost Anguilla anguilla. Eel intestinal epithelium......, when symmetrically bathed with Ringer solution, develops a net Cl- current giving rise to a negative transepithelial potential at the basolateral side of the epithelium. The eel intestinal epithelium responded to a hypotonic challenge with a biphasic decrease in the transepithelial voltage (V......(te)) and the short circuit current (I(sc)). This electrophysiological response correlated with a regulatory volume decrease (RVD) response, recorded by morphometrical measurement of the epithelium height. Changes in the transepithelial resistance were also observed following the hypotonicity exposure...

  18. Interactive effects of dietary composition and hormonal treatment on reproductive development of cultured female European eel, Anguilla anguilla

    DEFF Research Database (Denmark)

    da Silva, Filipa; Støttrup, Josianne Gatt; Kjørsvik, Elin

    2016-01-01

    Farmed female eels were fed two experimental diets with similar proximate composition but different n-3 polyunsaturated fatty acid (PUFA) levels. Both diets had similar levels of arachidonic acid (ARA), while levels of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) in one diet were...... approximately 4.5 and 2.6 times higher compared to the other diet, respectively. After the feeding period, each diet group was divided into two and each half received one of two hormonal treatments using salmon pituitary extract (SPE) for 13 weeks: i) a constant hormone dose of 18.75mg SPE/kg initial body...

  19. Biological impact of polycyclic aromatic hydrocarbons (PAH) on european eel Definition and validation of bio-marker useful in situ; Impact biologique des hydrocarbures aromatiques polycycliques (HAP) sur l'anguille europeenne. Definition et validation de biomarqueurs in situ

    Energy Technology Data Exchange (ETDEWEB)

    Buet, A.

    2002-02-15

    In the natural environment, especially in aquatic ecosystems, the presence of polycyclic aromatic hydrocarbons (PAH) can have deleterious effects. The aim of this project was to assess the biological impact of PAH on the European eel (Anguilla anguilla) and to define a series of bio-markers useful in situ. The originality of this field study comes from the variety of the considered factors and the choice of a protected site. Bio-markers validation requires the knowledge of normal variations of the selected parameters. Therefore, the first objective of our study was to assess the effects of natural factors on the eco-physiological characteristics of an eel population collected from the National Reserve of Camargue. Bio-metric and metabolic parameters were measured as well as enzymatic markers of contamination: biotransformation activities (EROD, GST, UDPHT), oxidative stress activities (CAT, SOD, GPx, SeGPx) and membrane activities (ATPases, AChE). The temporal evolutions and the nutritional state influenced significantly the answer of these indicators of contamination in the studied population. On the other hand, the effect of sexual maturity and parasitism by the nematode Anguillicola crassus was reduced. After confirming a local atmospheric contribution in PAH, we tried to understand the accumulation patterns of these compounds within organisms and organs. Therefore, the analysis of PAH were performed on the bile, the liver and the muscle samples of European eels. Whatever the season, the sampling site, the sexual maturity and the sanitary state of eels, the PAH tissue contamination was general but fluctuating. The localization of the contamination gives information about its persistence. Chronologically, bile accumulation reflects a recent intoxication, whereas the liver gives a medium-term contamination image and the muscle impregnation represents a longer-term storage. The PAH concentrated in fat tissues but these concentrations were not systematically

  20. Micro-PIXE line-scan measurements of the yellow eel's otolith

    International Nuclear Information System (INIS)

    Zheng, Y.; Guo, H.; Tang, W.; Wei, K.; Shen, H.; Yang, M.; Mi, Y.

    2011-01-01

    Anguilla japonica has a high economic value. The abundance had decreased significantly due to excessive fishing and change in the aquatic ecology. Life history patterns of A. japonica have been studied to prevent excessive fishing and make management plans. Strontium (Sr)-calcium (Ca) ratio along a line down the long axis from the core to the edge of the yellow eel's otolith was measured using micro proton induced X-ray emission (micro-PIXE). An efficient and precise method was proposed to locate the core where an otolith begins to grow, based on Sr concentration and distribution. Using this method, life history patterns of the yellow eels collected from Jingjiang River in China were investigated. In general, there are two types, river eels and estuarine eels.

  1. Internal redistribution of radiolabelled silver among tissues of rainbow trout (Oncorhynchus mykiss) and European eel (Anguilla anguilla)

    DEFF Research Database (Denmark)

    Hogstrand, C.; Grosell, M.; Wood, C.M.

    2003-01-01

    chloride water). Contents and concentrations of Ag-110m(l) in tissues and body fluids were then monitored over a 67-day post-exposure period in Ag(I)-free water of the same chloride levels. Changing the speciation of Ag(l) in the water had no effect on the whole body load of Ag-110m(I), but did result......(I) through the 67-day period, whereas the body burden of Ag-110m(I) in eel was reduced to half initial values by day 67. (C) 2002 Elsevier Science B.V. All rights reserved....... in differences in internal distribution. In trout, changing water Ag(I) speciation significantly altered elimination or accumulation of Ag(I) in several body compartments. Notably, trout exposed to AgClaq eliminated Ag-110m(l) from the kidney more quickly than trout exposed to Ag(l) primarily as Ag...

  2. Lethal toxicity of Lindane on a teleost fish, Anguilla anguilla from Albufera Lake (Spain): hardness and temperature effects.

    Science.gov (United States)

    Ferrando, M D; Almar, M M; Andreu, E

    1988-02-01

    This paper reports the results of toxicity tests conducted using Anguilla anguilla under three different water temperature (15, 22 and 29 degrees C) and two hardness regimes (250 and greater than 600 ppm CaCO3). The 96-h LC50 increased in the experimental medium (p less than 0.05) by an order of magnitude from 0.32 to 0.45 mg/L between 15 and 29 degrees C. However in the natural medium it is similar (p greater than 0.05) (0.54 to 0.55 mg/L) for these same temperatures. The toxicity of Lindane on eels increased when the water hardness decreased. The 24, 48, 72 and 96-h LC50 for this fish in both media is less at 15 degrees C (96-h LC50 = 0.32 and 0.55 mg/L) than at 29 degrees C (96-h LC50 = 0.45 and 0.55 mg/L). These results suggest that the toxicity of Lindane presents a negative temperature coefficient.

  3. Micro-PIXE line-scan measurements of the yellow eel's otolith

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, Y. [Applied Ion Beam Physics Laboratory, Institute of Modern Physics, Fudan University, Shanghai 200433 (China); Guo, H.; Tang, W.; Wei, K. [Laboratory of Ichthyology, Shanghai Ocean University, Shanghai 201306 (China); Shen, H., E-mail: haoshen@fudan.edu.cn [Applied Ion Beam Physics Laboratory, Institute of Modern Physics, Fudan University, Shanghai 200433 (China); Yang, M.; Mi, Y. [Applied Ion Beam Physics Laboratory, Institute of Modern Physics, Fudan University, Shanghai 200433 (China)

    2011-10-15

    Anguilla japonica has a high economic value. The abundance had decreased significantly due to excessive fishing and change in the aquatic ecology. Life history patterns of A. japonica have been studied to prevent excessive fishing and make management plans. Strontium (Sr)-calcium (Ca) ratio along a line down the long axis from the core to the edge of the yellow eel's otolith was measured using micro proton induced X-ray emission (micro-PIXE). An efficient and precise method was proposed to locate the core where an otolith begins to grow, based on Sr concentration and distribution. Using this method, life history patterns of the yellow eels collected from Jingjiang River in China were investigated. In general, there are two types, river eels and estuarine eels.

  4. Effects of salinity and sea salt type on egg activation, fertilization, buoyancy and early embryology of European eel, Anguilla anguilla

    DEFF Research Database (Denmark)

    Sørensen, Sune Riis; Butts, Ian; Munk, Peter

    2016-01-01

    sizes, while the remaining four salt types resulted in smaller eggs. All salt types except NaCl treatments led to high fertilization rates and had no effect on fertilization success as well as egg neutral buoyancies at 7 h post-fertilization. The study points to the importance of considering ionic...... and egg buoyancy. Egg diameter after activation, using natural seawater adjusted to different salinities, varied among female eels, but no consistent pattern emerged. Activation salinities between 30–40 practical salinity unit (psu) produced higher quality eggs and generally larger egg diameters. Chorion...

  5. Cryopreservation of green fluorescent protein (GFP)-labeled primordial germ cells with GFP fused to the 3' untranslated region of the nanos gene by vitrification of Japanese eel (Anguilla japonica) somite stage embryos.

    Science.gov (United States)

    Kawakami, Y; Ishihara, M; Saito, T; Fujimoto, T; Adachi, S; Arai, K; Yamaha, E

    2012-12-01

    Primordial germ cells (PGC) are the only cell type in developing embryos with the potential to transmit genetic information to the next generation. In this study, PGC of Japanese eel (Anguilla japonica) were visualized by injection of mRNA synthesized from a construct carrying the green fluorescent protein (GFP) gene fused to the 3' untranslated region of the Japanese eel nanos gene. We investigated the feasibility of cryopreserving Japanese eel PGC by vitrification of dechorionated whole somite stage embryos. The GFP-labeled PGC were rapidly cooled using liquid nitrogen after exposure to a pretreatment solution containing 1.5 M cryoprotectant (methanol, dimethyl sulfoxide, and glycerol for 10 min and ethylene glycol for 10, 20, and 30 min) and a vitrification solution containing 3 M cryoprotectant and 0.5 M sucrose for 1, 5, and 10 min. Ethylene glycerol is an effective cryoprotectant for embryonic cells and shows no evidence of ice formation after thawing. Vitrified and thawed PGC were transplanted into blastula stage embryos from zebrafish (Danio rerio). The GFP-labeled PGC migrated toward the host gonadal ridge, suggesting maintenance of their normal migration motility. These techniques may assist in achieving inter- and intraspecies germ-line chimers using donor Japanese eel PGC.

  6. Ontogeny and growth of early life stages of captive-bred European eel

    DEFF Research Database (Denmark)

    Sørensen, Sune Riis; Tomkiewicz, Jonna; Munk, Peter

    2016-01-01

    of viable eggs and larvae of European eel, providing the basis for studies on early life stages of this species in captivity. In this study, we describe and illustrate morphological characteristics of eggs, embryos, and larvae from fertilization to termination of the yolk sac stage and provide a comparison...... forms a large perivitelline space, reaching an egg diameter of 1.45 ± 0.12 mm at 3.0 to 3.5 h post fertilization. Embryonic development from fertilization to larval hatch lasted ~46–48 h at 20 °C with the larvae emerging in a relatively undeveloped stage with a protuberant yolk sac. During the period......-sustained aquaculture of this high-value and critically endangered species. Statement of relevance: European eel is a high-value species in aquaculture, however, production is presently hampered by reliance on wild caught fry. Captive production of glass eels will reopen markets in Europe and Asia, benefiting European...

  7. PENGARUH KOMBINASI PAKAN BUATAN DAN PAKAN ALAMI CACING SUTERA (Tubifex tubifex DENGAN PERSENTASE YANG BERBEDA TERHADAP RETENSI PROTEIN, LEMAK DAN ENERGI PADA IKAN SIDAT (Anguilla bicolor

    Directory of Open Access Journals (Sweden)

    Sri Subekti

    2011-04-01

    Full Text Available Indonesian short fin eel (Anguilla bicolor was one of Indonesian fishery commodities which have high value not only in local market but also western market. Advantages of Indonesian short fin eel not only their high value because of prospectively in international market, but also the quality of  Indonesian short fin eel itself that contain high vitamin and micronutrient. Weaknesses of Indonesian short fin eel was their growth classified slow. That was can be overcome by giving the exact feed. The purpose of this research was to know the effect of combination between artificial feed and natural feed with different percentage to protein retention, fat retention and energy retention of Indonesian short fin eel (Anguilla bicolor. This research used experimental method and Completely Random Design method with five treatments. Each treatment was replicated four times. The treatment used were : 100% of artificial feed (A, 75% of artificial feed and 25% of natural feed (B, 50% of artificial feed and 50% of natural feed (C, 25% of artificial feed and 75% natural feed (D, and 100% natural feed (E. The main parameters measured were protein, fat, and energy retentions. The supporting parameters observed was growth rate and water quality. Data analysis used analysis of variance (ANOVA to know the effect of the treatments. The  difference among treatments were known by using Duncan’s Multiple Range Test (DMRT.The result showed that combination between artificial  and natural feeds with difference percentage showed different effect (p<0,05 to fat retention of Indonesian short fin eel therefore they didn’t showed different effect to protein and energy retentions of Indonesian short fin eel (p>0,05. Water quality of Indonesian short fin eel rearing medium was 28-31oC in temperatures, 7-8,5 in pH, 3,5-5,8 mg/l in dissolved oxygen and 0,003 mg/l in ammonia. Keywords : Anguilla bicolor, artificial feed, Tubifex tubifex, protein retention, fat retention

  8. Histological Features of the Gastrointestinal Tract of Wild Indonesian Shortfin Eel, Anguilla bicolor bicolor (McClelland, 1844, Captured in Peninsular Malaysia

    Directory of Open Access Journals (Sweden)

    Nurrul Shaqinah Nasruddin

    2014-01-01

    Full Text Available This study was conducted to record the histological features of the gastrointestinal tract of wild Indonesian shortfin eel, Anguilla bicolor bicolor (McClelland, 1844, captured in Peninsular Malaysia. The gastrointestinal tract was segmented into the oesophagus, stomach, and intestine. Then, the oesophagus was divided into five (first to fifth, the stomach into two (cardiac and pyloric, and the intestine into four segments (anterior, intermediate, posterior, and rectum for histological examinations. The stomach had significantly taller villi and thicker inner circular muscles compared to the intestine and oesophagus. The lamina propria was thickest in stomach, significantly when compared with oesophagus, but not with the intestine. However, the intestine showed significantly thicker outer longitudinal muscle while gastric glands were observed only in the stomach. The histological features were closely associated with the functions of the different segments of the gastrointestinal tract. In conclusion, the histological features of the gastrointestinal tract of A. b. bicolor are consistent with the feeding habit of a carnivorous fish.

  9. Histological features of the gastrointestinal tract of wild Indonesian shortfin eel, Anguilla bicolor bicolor (McClelland, 1844), captured in Peninsular Malaysia.

    Science.gov (United States)

    Nasruddin, Nurrul Shaqinah; Azmai, Mohammad Noor Amal; Ismail, Ahmad; Saad, Mohd Zamri; Daud, Hassan Mohd; Zulkifli, Syaizwan Zahmir

    2014-01-01

    This study was conducted to record the histological features of the gastrointestinal tract of wild Indonesian shortfin eel, Anguilla bicolor bicolor (McClelland, 1844), captured in Peninsular Malaysia. The gastrointestinal tract was segmented into the oesophagus, stomach, and intestine. Then, the oesophagus was divided into five (first to fifth), the stomach into two (cardiac and pyloric), and the intestine into four segments (anterior, intermediate, posterior, and rectum) for histological examinations. The stomach had significantly taller villi and thicker inner circular muscles compared to the intestine and oesophagus. The lamina propria was thickest in stomach, significantly when compared with oesophagus, but not with the intestine. However, the intestine showed significantly thicker outer longitudinal muscle while gastric glands were observed only in the stomach. The histological features were closely associated with the functions of the different segments of the gastrointestinal tract. In conclusion, the histological features of the gastrointestinal tract of A. b. bicolor are consistent with the feeding habit of a carnivorous fish.

  10. Procamallanus (Spirocamallanus) anguillae sp. n. (Camallanidae) and some other nematodes from the Indonesian shortfin eel Anguilla bicolor in Thailand

    Czech Academy of Sciences Publication Activity Database

    Moravec, František; Taraschewski, H.; Thairungroj Anantaphruti, M.; Maipanich, W.; Laoprasert, T.

    2006-01-01

    Roč. 100, č. 1 (2006), s. 69-75 ISSN 0932-0113 R&D Projects: GA ČR(CZ) GA524/06/0170 Institutional research plan: CEZ:AV0Z60220518 Keywords : Procamallanus * Anguilla * Thailand Subject RIV: GJ - Animal Vermins ; Diseases, Veterinary Medicine Impact factor: 1.140, year: 2006

  11. Genomic Sequence of a Ranavirus Isolated from Short-Finned Eel (Anguilla australis)

    DEFF Research Database (Denmark)

    Subramaniam, Kuttichantran; Toffan, Anna; Cappellozza, Elisabetta

    2016-01-01

    The short-finned eel ranavirus (SERV) was isolated from short-finned eel imported to Italy from New Zealand. Phylogenomic analyses revealed that SERV is a unique member of the genus Ranavirus, family Iridoviridae, branching at the base of the tree near other fish ranaviruses....

  12. Redescriptions of two frequently recorded but poorly known hemiurid digeneans, Lecithochirium musculus (Looss, 1907) (Lecithochiriinae) and Ectenurus lepidus Looss, 1907 (Dinurinae), based on material from the western Mediterranean

    Czech Academy of Sciences Publication Activity Database

    Carreras-Aubets, M.; Montero, E. E.; Kostadinova, Aneta; Gibson, D. I.; Carrasson, M.

    2012-01-01

    Roč. 82, č. 3 (2012), s. 185-199 ISSN 0165-5752 R&D Projects: GA ČR GBP505/12/G112 Institutional support: RVO:60077344 Keywords : EELS ANGUILLA-ANGUILLA * HELMINTH-PARASITES * MARINE FISHES * CONGER-CONGER * COASTAL LAGOONS * TELEOST FISH * EUROPEAN EEL * COMMUNITIES * TREMATODES * DIVERSITY Subject RIV: GJ - Animal Vermins ; Diseases, Veterinary Medicine Impact factor: 1.260, year: 2012 http://link.springer.com/article/10.1007%2Fs11230-012-9357-8

  13. Identification and localization of the structural proteins of anguillid herpesvirus 1

    NARCIS (Netherlands)

    Beurden, van S.J.; Leroy, B.; Wattiez, R.; Haenen, O.L.M.; Boeren, S.; Vervoort, J.J.M.; Peeters, B.P.H.; Rottier, P.J.M.; Engelsma, M.Y.; Vanderplasschen, A.F.

    2011-01-01

    Many of the known fish herpesviruses have important aquaculture species as their natural host, and may cause serious disease and mortality. Anguillid herpesvirus 1 (AngHV-1) causes a hemorrhagic disease in European eel, Anguilla anguilla. Despite their importance, fundamental molecular knowledge on

  14. Effects of acute and chronic experimental contamination on direct cesium 137 uptake by the eel, Anguilla anguilla L

    International Nuclear Information System (INIS)

    Foulquier, Luc; Lambrechts, Alain.

    1982-03-01

    This study covers the effects of different types of contamination on direct cesium 137 uptake by the eel. In the first experiment (acute contamination), simulating a waste discharge, the fish were kept in water with a rapidly decreasing cesium 137 activity. In a second experiment (chronic contamination), the water activity increased constantly, simulating increasing waste frequency and activity levels. Irrespective of the type of contamination, radiocesium retention by eels is low ( [fr

  15. A new species of Procamallanus (Nematoda: Camallanidae) from Pacific eels (Anguilla spp.)

    Czech Academy of Sciences Publication Activity Database

    Moravec, František; Justine, J.-L.; Würtz, J.; Taraschewski, H.; Sasal, P.

    2006-01-01

    Roč. 92, č. 1 (2006), s. 130-137 ISSN 0022-3395 R&D Projects: GA ČR(CZ) GA524/06/0170 Institutional research plan: CEZ:AV0Z60220518 Keywords : Procamallanus * Anguilla Subject RIV: GJ - Animal Vermins ; Diseases, Veterinary Medicine Impact factor: 1.300, year: 2006

  16. Proximate content of wild and cultured eel (Anguilla bicolor) in different part of body

    Science.gov (United States)

    Wijayanti, I.; Susilo, E. S.

    2018-02-01

    Proximate content in fish varies depends on intrinsic and extrinsic factors. Intrinsic factors include species, sexual maturity, size and body parts. Extrinsic factors include habitat, season and type of food (diet). This study aimed to know the effect of fish body parts (intrinsic factor) on proximate levels in wild and cultured eel (extrinsic). The experimental design used factorial completely randomized design with two factors 2x3. The first factor is the habitat of eel (wild and cultured) and the second factor is the part of the body (head, body and tail) with five replications. The result of statistical analysis showed that there was interaction between fish habitat and body part on moisture, protein, ash and carbohydrate content (P interaction on fat content and energy (P> 0.05). The highest water content (67.02%) was found in head of wild and the lowest one (59.44%) in the tail of wild eel; The highest protein content (18.09%) was found in the body of cultured eel and the lowest one (15.72%) was in the body of wild eel; The highest ash content (3.73%) was the head of wild eel and the lowest (1.32%) was in the body of cultured eel; The highest carbohydrate (3.73%) was found in the head of cultured eel and the lowest one (0.16%) was in the body of cultured. The wild eel had higher fat content and energy than cultured one, while the fat content and energy in body and tail were higher than in head.

  17. Signatures of natural selection between life cycle stages separated by metamorphosis in European eel

    DEFF Research Database (Denmark)

    Pujolar, J.M.; Jacobsen, M.W.; Bekkevold, Dorte

    2015-01-01

    Species showing complex life cycles provide excellent opportunities to study the genetic associations between life cycle stages, as selective pressures may differ before and after metamorphosis. The European eel presents a complex life cycle with two metamorphoses, a first metamorphosis from larvae...... into glass eels (juvenile stage) and a second metamorphosis into silver eels (adult stage). We tested the hypothesis that different genes and gene pathways will be under selection at different life stages when comparing the genetic associations between glass eels and silver eels. Results: We used two sets...... of markers to test for selection: first, we genotyped individuals using a panel of 80 coding-gene single nucleotide polymorphisms (SNPs) developed in American eel; second, we investigated selection at the genome level using a total of 153,423 RAD-sequencing generated SNPs widely distributed across the genome...

  18. ESTIMATING THE STOCK OF GLASS EELS IN AN ESTUARY BY MARK-RECAPTURE EXPERIMENTS USING VITAL DYES

    Directory of Open Access Journals (Sweden)

    BRIAND C.

    2005-10-01

    Full Text Available Glass eels (Anguilla anguilla arriving after the fishing season in the Vilaine estuary (France were caught by boat and at a trapping ladder located at a blocking dam upstream in the estuary. They were marked with Bismarck brown, rhodamine B or neutral red, and released into the estuary. The effect of marking on behaviour, mortality and recapture differed according to the dye and concentration used. The glass eels also differed in response to marking according to their origin. Estuarine glass eels were clearly desynchronized in their selective tidal stream transport and left the release area after a few tidal cycles. Trapped glass eels were less sensitive to marking. They remained in the release area and were recaptured in larger number both in the trapping ladder and in the estuary. These results supported a model of two behavioral fractions in the estuary: flow-carried migrants and active glass eels with stronger rheotactic behaviour. The proportion of active glass eels in the estuary shifted from none for the two weeks after the fishery closure, to 10% value of the total stock. At the trapping ladder, the migration ended in June each year, while a large stock was still present in the estuary. These observations favour the interpretation of a short duration of the active phase at this site followed by the transition towards a more benthic behavior. The daily efficiency of the trapping ladder was calculated as 4% of the active stock from both stock estimations and average recapture rate. This value was consistent with the low annual efficiency of the trapping ladder, calculated as 30% of the estuarine stock of glass eels that arrived after the fishing season.

  19. Development and validation of a real-time PCR assay for the detection of anguillid herpesvirus 1.

    Science.gov (United States)

    van Beurden, S J; Voorbergen-Laarman, M A; Roozenburg, I; van Tellingen, J; Haenen, O L M; Engelsma, M Y

    2016-01-01

    Anguillid herpesvirus 1 (AngHV1) causes a haemorrhagic disease with increased mortality in wild and farmed European eel, Anguilla anguilla (L.) and Japanese eel Anguilla japonica, Temminck & Schlegel). Detection of AngHV1 is currently based on virus isolation in cell culture, antibody-based typing assays or conventional PCR. We developed, optimized and concisely validated a diagnostic TaqMan probe based real-time PCR assay for the detection of AngHV1. The primers and probe target AngHV1 open reading frame 57, encoding the capsid protease and scaffold protein. Compared to conventional PCR, the developed real-time PCR is faster, less labour-intensive and has a reduced risk of cross-contamination. The real-time PCR assay was shown to be analytically sensitive and specific and has a high repeatability, efficiency and r(2) -value. The diagnostic performance of the assay was determined by testing 10% w/v organ suspensions and virus cultures from wild and farmed European eels from the Netherlands by conventional and real-time PCR. The developed real-time PCR assay is a useful tool for the rapid and sensitive detection of AngHV1 in 10% w/v organ suspensions from wild and farmed European eels. © 2015 John Wiley & Sons Ltd.

  20. Population demographics of American eels Anguilla rostrata in two Arkansas, U.S.A., catchments that drain into the Gulf of Mexico.

    Science.gov (United States)

    Cox, C A; Quinn, J W; Lewis, L C; Adams, S R; Adams, G L

    2016-03-01

    The goal of this study was to compare American eel Anguilla rostrata life history in two inland river systems in Arkansas, U.S.A., that ultimately discharge into the Gulf of Mexico via the Mississippi River and the Red-Atchafalaya catchments. From 21 June 2011 to 24 April 2014, 238 yellow-phase A. rostrata were captured in the middle Ouachita River and tributaries using boat electrofishing and 39 in the lower White River using multiple sampling gears. Most of them were caught downstream of dams in both basins (61%). Medium-sized A. rostrata ranging from 225 to 350 mm total length (LT ) were the most abundant size group in the Ouachita River basin, but they were absent from the White River. Mean LT at age 4 years (i.e. youngest shared age) was 150 mm greater for the White River than the Ouachita River basin. Anguilla rostrata appeared to have a greater initial LT (i.e. minimum size upon arrival) in the White River that allowed them to reach a gonado-somatic index (IG ) of 1·5 up to 4 years earlier, and downstream migration appeared to occur 5 years earlier at 100 mm greater LT ; these differences may be related to increased river fragmentation by dams in the Ouachita River basin. Growth and maturation of A. rostrata in this study were more similar to southern populations along the Atlantic coast than other inland populations. Adult swimbladder nematodes Anguillicoloides crassus were not present in any of the 214 swimbladders inspected. Gulf of Mexico catchments may be valuable production areas for A. rostrata and data from these systems should be considered as range-wide protection and management plans are being developed. © 2016 The Fisheries Society of the British Isles.

  1. Influence of water temperature and feeding regime on otolith growth in Anguilla japonica glass eels and elvers: does otolith growth cease at low temperatures?

    Science.gov (United States)

    Fukuda, N; Kuroki, M; Shinoda, A; Yamada, Y; Okamura, A; Aoyama, J; Tsukamoto, K

    2009-06-01

    The influences of water temperature and feeding regime on otolith growth in Anguilla japonica glass eels and elvers were investigated using individuals reared at 5, 10, 15, 20, 25 and 30 degrees C and in fed or unfed conditions at salinity 32 after their otoliths were marked with alizarin complexone (ALC). To eliminate the difficulty of observing the edges of otoliths with optical (OM) or scanning electron (SEM) microscopes, three to 10 individuals were sampled from each tank at 10, 20 and 30 days during the experiment and reared for an additional 10 days at 25 degrees C after their otoliths were marked a second time. Otolith growth and the number of increments were measured using both OM and SEM. Most A. japonica commenced feeding after 10 days at 20-30 degrees C or after 20 days at 15 degrees C, but no feeding occurred at 5 and 10 degrees C. No otolith growth occurred at 5 and 10 degrees C except in two individuals with minimal increment deposition at 10 degrees C. Otolith growth was proportional to water temperature within 15-25 degrees C and not different between 25 and 30 degrees C. At 15, 25 and 30 degrees C, the mean otolith growth rate in fed conditions was higher than in unfed conditions. The number of increments per day was significantly different among water temperatures (0.00-0.01 day(-1) at 5 and 10 degrees C, 0.43-0.48 day(-1) at 15 degrees C and 0.94-1.07 day(-1) at 20-30 degrees C). These results indicated that otolith growth in A. japonica glass eels and elvers was affected by temperature and ceased at otoliths of wild-caught A. japonica glass eels and elvers need to carefully consider the water temperatures potentially experienced by the juveniles in the wild.

  2. Shark predation on migrating adult American eels (Anguilla rostrata in the Gulf of St. Lawrence.

    Directory of Open Access Journals (Sweden)

    Mélanie Béguer-Pon

    Full Text Available In an attempt to document the migratory pathways and the environmental conditions encountered by American eels during their oceanic migration to the Sargasso Sea, we tagged eight silver eels with miniature satellite pop-up tags during their migration from the St. Lawrence River in Québec, Canada. Surprisingly, of the seven tags that successfully transmitted archived data, six were ingested by warm-gutted predators, as observed by a sudden increase in water temperature. Gut temperatures were in the range of 20 to 25°C-too cold for marine mammals but within the range of endothermic fish. In order to identify the eel predators, we compared their vertical migratory behavior with those of satellite-tagged porbeagle shark and bluefin tuna, the only endothermic fishes occurring non-marginally in the Gulf of St. Lawrence. We accurately distinguished between tuna and shark by using the behavioral criteria generated by comparing the diving behavior of these two species with those of our unknown predators. Depth profile characteristics of most eel predators more closely resembled those of sharks than those of tuna. During the first days following tagging, all eels remained in surface waters and did not exhibit diel vertical migrations. Three eels were eaten at this time. Two eels exhibited inverse diel vertical migrations (at surface during the day during several days prior to predation. Four eels were eaten during daytime, whereas the two night-predation events occurred at full moon. Although tagging itself may contribute to increasing the eel's susceptibility to predation, we discuss evidence suggesting that predation of silver-stage American eels by porbeagle sharks may represent a significant source of mortality inside the Gulf of St. Lawrence and raises the possibility that eels may represent a reliable, predictable food resource for porbeagle sharks.

  3. Temporal progression in migratory status and sexual maturation in European silver eels during downstream migration

    NARCIS (Netherlands)

    Palstra, A.P.; Guerrero, M.A.; Klein Breteler, J.G.P.; Thillart, G.E.E.J.M.

    2011-01-01

    The onset of downstream migration of European eels is accompanied by a cessation of feeding and the start of sexual maturation which stresses the link between metabolism and sexual maturation, also suggesting an important role for exercise. Exercise has been tested with eels in swim tunnels and was

  4. PEMANFAATAN LIMBAH IKAN SIDAT INDONESIA (Anguilla bicolor SEBAGAI TEPUNG PADA INDUSTRI PENGOLAHAN IKAN DI PALABUHANRATU, KABUPATEN SUKABUMI

    Directory of Open Access Journals (Sweden)

    RA Hangesti Emi Widyasari

    2014-05-01

    Full Text Available ABSTRACTThis research aims to analyze the nutritive value of flour head, liver powder and bone meal as by product of Indonesian eel (Anguilla bicolor processing. Eel waste flour was made by using a thermal process in the drum dryer fish flouring mill PT. Carmelitha Lestari in Bogor, whereas proximate analysis for chemical tests were performed in the laboratory of Integrated Chemical Laboratory, IPB and direct observation was conducted in PT Jawa Suisan Indah, Palabuhanratu Sukabumi district in October 2012—April 2013. The nutritive value based on proximate analysis showed that head flour, liver flour, and bone flour contained protein 61.78%, 53.92%, and 41.01%; fat 15.55%, 27.28%, 13.07%; carbohydrate 11.48%; 14.96%, 8.13%; water 5.44%, 8.48%, 3.01%; ash 12.95%, 3.62%, 37.49%, and crude fiber 1.33%, 0.04%, 1.11%, respectively.Keywords: Anguilla bicolor, bone flour, head flour, liver flour, nutritive valueABSTRAKPenelitian ini bertujuan untuk menganalisis kandungan gizi tepung kepala, tepung tulang dan tepung hati ikan yang merupakan limbah pengolahan ikan sidat Indonesia (Anguilla bicolor. Tepung limbah ikan sidat dibuat berdasarkan proses termal menggunakan drum dryer di pabrik penepungan ikan PT. Carmelitha Lestari di Bogor dan analisis proksimat untuk uji kimiawi dilakukan di Laboratorium Kimia Terpadu, IPB serta observasi langsung di PT Jawa Suisan Indah, Palabuhanratu Kabupaten Sukabumi pada bulan Oktober 2012—April 2013. Hasil analisis proksimat tepung kepala, tepung hati dan tepung tulang mengandung protein berturut-turut sebesar 61.78%, 53.92%, dan 41.01%; lemak sebesar 15.55%; 27.28%; 13.07%, karbohidrat sebesar 11.48%; 14.96%; 8.13%, kadar air sebesar 5.44%; 8.48%; 3.01%, kadar abu 12.95%; 3.62%; 37.49% dan serat kasar 1.33%; 0.04%; 1.11%.Kata kunci: Anguilla bicolor, nilai gizi, tepung hati, tepung kepala, tepung tulang

  5. Oceanic migration and spawning of anguillid eels.

    Science.gov (United States)

    Tsukamoto, K

    2009-06-01

    Many aspects of the life histories of anguillid eels have been revealed in recent decades, but the spawning migrations of their silver eels in the open ocean still remains poorly understood. This paper overviews what is known about the migration and spawning of anguillid species in the ocean. The factors that determine exactly when anguillid eels will begin their migrations are not known, although environmental influences such as lunar cycle, rainfall and river discharge seem to affect their patterns of movement as they migrate towards the ocean. Once in the ocean on their way to the spawning area, silver eels probably migrate in the upper few hundred metres, while reproductive maturation continues. Although involvement of a magnetic sense or olfactory cues seems probable, how they navigate or what routes they take are still a matter of speculation. There are few landmarks in the open ocean to define their spawning areas, other than oceanographic or geological features such as oceanic fronts or seamounts in some cases. Spawning of silver eels in the ocean has never been observed, but artificially matured eels of several species have exhibited similar spawning behaviours in the laboratory. Recent collections of mature adults and newly spawned preleptocephali in the spawning area of the Japanese eel Anguilla japonica have shown that spawning occurs during new moon periods in the North Equatorial Current region near the West Mariana Ridge. These data, however, show that the latitude of the spawning events can change among months and years depending on oceanographic conditions. Changes in spawning location of this and other anguillid species may affect their larval transport and survival, and appear to have the potential to influence recruitment success. A greater understanding of the spawning migration and the choice of spawning locations by silver eels is needed to help conserve declining anguillid species.

  6. The pituitary gland of the European eel reveals massive expression of genes involved in the melanocortin system.

    Directory of Open Access Journals (Sweden)

    Eirill Ager-Wick

    Full Text Available Hormones secreted from the pituitary gland regulate important processes such as development, growth and metabolism, reproduction, water balance, and body pigmentation. Synthesis and secretion of pituitary hormones are regulated by different factors from the hypothalamus, but also through feedback mechanisms from peripheral organs, and from the pituitary itself. In the European eel extensive attention has been directed towards understanding the different components of the brain-pituitary-gonad axis, but little is known about the regulation of upstream processes in the pituitary gland. In order to gain a broader mechanistic understanding of the eel pituitary gland, we have performed RNA-seq transcriptome profiling of the pituitary of prepubertal female silver eels. RNA-seq reads generated on the Illumina platform were mapped to the recently assembled European eel genome. The most abundant transcript in the eel pituitary codes for pro-opiomelanocortin, the precursor for hormones of the melanocortin system. Several genes putatively involved in downstream processing of pro-opiomelanocortin were manually annotated, and were found to be highly expressed, both by RNA-seq and by qPCR. The melanocortin system, which affects skin color, energy homeostasis and in other teleosts interacts with the reproductive system, has so far received limited attention in eels. However, since up to one third of the silver eel pituitary's mRNA pool encodes pro-opiomelanocortin, our results indicate that control of the melanocortin system is a major function of the eel pituitary.

  7. The nervus terminalis ganglion in Anguilla rostrata: an immunocytochemical and HRP histochemical analysis.

    Science.gov (United States)

    Grober, M S; Bass, A H; Burd, G; Marchaterre, M A; Segil, N; Scholz, K; Hodgson, T

    1987-12-08

    Immunocytochemistry and retrograde horseradish peroxidase (HRP) transport were used to study the ganglion of the nervus terminalis in the American eel, Anguilla rostrata. Luteinizing hormone releasing hormone (LHRH) like immunoreactivity was found in large, ganglion-like cells located ventromedially at the junction of the telencephalon and olfactory bulb and in fibers within the retina and olfactory epithelium. HRP transport from the retina demonstrated direct connections with both the ipsi- and contralateral populations of these ganglion-like cells. Given the well-documented role of both olfaction and vision during migratory and reproductive phases of the life cycle of eels, the robust nature of a nervus terminalis system in these fish may present a unique opportunity to study the behavioral correlates of structure-function organization in a discrete population of ganglion-like cells.

  8. Changes in the role of the thyroid axis during metamorphosis of the Japanese eel, Anguilla japonica.

    Science.gov (United States)

    Sudo, Ryusuke; Okamura, Akihiro; Kuroki, Mari; Tsukamoto, Katsumi

    2014-08-01

    To clarify the role of thyroid function during metamorphosis from leptocephalus to glass eel in the Japanese eel, we examined the histology of the thyroid gland and measured whole-body concentrations of thyroid hormones, thyroxine (T4) and triiodothyronine (T3), and thyroid stimulating hormone β-subunit TSH (TSHβ) mRNA expression levels in five stages of artificially hatched eels (leptocephalus, early-metamorphosis, late-metamorphosis, glass eel, and elver). During metamorphosis, the inner colloid of thyroid follicles showed positive immunoreactivity for T4, and both T4 and T3 levels were significantly increased, whereas a small peak of TSHβ mRNA level was observed at the early-metamorphosis stage. Similarly, TSHβ mRNA levels were highest in the glass eel stage, and then decreased markedly in the elver stage. In contrast to TSHβ mRNA expression, thyroid hormones (both T4 and T3) increased further from the glass eel to elver stages. These results indicated that thyroid function in the Japanese eel was active both during and after metamorphosis. Therefore, the thyrotropic axis may play important roles not only in metamorphosis but also in subsequent inshore or upstream migrations. © 2014 Wiley Periodicals, Inc.

  9. Signatures of natural selection between life cycle stages separated by metamorphosis in European eel.

    Science.gov (United States)

    Pujolar, J M; Jacobsen, M W; Bekkevold, D; Lobón-Cervià, J; Jónsson, B; Bernatchez, L; Hansen, M M

    2015-08-13

    Species showing complex life cycles provide excellent opportunities to study the genetic associations between life cycle stages, as selective pressures may differ before and after metamorphosis. The European eel presents a complex life cycle with two metamorphoses, a first metamorphosis from larvae into glass eels (juvenile stage) and a second metamorphosis into silver eels (adult stage). We tested the hypothesis that different genes and gene pathways will be under selection at different life stages when comparing the genetic associations between glass eels and silver eels. We used two sets of markers to test for selection: first, we genotyped individuals using a panel of 80 coding-gene single nucleotide polymorphisms (SNPs) developed in American eel; second, we investigated selection at the genome level using a total of 153,423 RAD-sequencing generated SNPs widely distributed across the genome. Using the RAD approach, outlier tests identified a total of 2413 (1.57%) potentially selected SNPs. Functional annotation analysis identified signal transduction pathways as the most over-represented group of genes, including MAPK/Erk signalling, calcium signalling and GnRH (gonadotropin-releasing hormone) signalling. Many of the over-represented pathways were related to growth, while others could result from the different conditions that eels inhabit during their life cycle. The observation of different genes and gene pathways under selection when comparing glass eels vs. silver eels supports the adaptive decoupling hypothesis for the benefits of metamorphosis. Partitioning the life cycle into discrete morphological phases may be overall beneficial since it allows the different life stages to respond independently to their unique selection pressures. This might translate into a more effective use of food and niche resources and/or performance of phase-specific tasks (e.g. feeding in the case of glass eels, migrating and reproducing in the case of silver eels).

  10. Genome-wide single-generation signatures of local selection in the panmictic European eel

    DEFF Research Database (Denmark)

    Pujolar, J. M.; Jacobsen, M. W.; Als, Thomas Damm

    2014-01-01

    Next-generation sequencing and the collection of genome-wide data allow identifying adaptive variation and footprints of directional selection. Using a large SNP data set from 259 RAD-sequenced European eel individuals (glass eels) from eight locations between 34 and 64oN, we examined the patterns...... of genome-wide genetic diversity across locations. We tested for local selection by searching for increased population differentiation using FST-based outlier tests and by testing for significant associations between allele frequencies and environmental variables. The overall low genetic differentiation...... with single-generation signatures of spatially varying selection acting on glass eels. After screening 50 354 SNPs, a total of 754 potentially locally selected SNPs were identified. Candidate genes for local selection constituted a wide array of functions, including calcium signalling, neuroactive ligand...

  11. Pengaruh pemberian pakan berupa campuran pelet ikan, ulat tepung (Tenebrio molitor, dan ganggang merah (Gracilaria foliifera terhadap pertumbuhan dan kelulushidupan ikan sidat (Anguilla bicolor

    Directory of Open Access Journals (Sweden)

    MUHAMMAD A. AZIZ HENDITAMA

    2015-05-01

    Full Text Available Henditama MAA, Harini M, Budiharjo A. 2015. The effect of giving mixtured feed of fish pellet, mealworm (Tenebrio molitor and red algae (Gracilaria foliifera to the growth and survival rate of eel (Anguilla bicolor. Bioteknologi 12: 22-28. High demand of eels (Anguilla bicolor in the world has not followed by the capability of domestic production. The purpose of this research are to determine the effect and the precise composition of the feed mixture in the form of fish pellets, mealworms (Tenebrio molitor, red algae (Gracilaria foliifera to the growth and survival rate of eels. This research used completely randomized design with four variations of mixtured feed in the form of fish pellet, mealworms, and red algae specifically P1 (100% ; 0% ; 0%, P2 (75% ; 20% ; 5%, P3 (50% ; 45% ; 5%, P4 (25% ; 70% ; 5%. This research also has been done in 90 days with feeding in twice a day. The data of growth, survival rate, and water quality was collected once a week. The data result has been analized by ANOVA. The data result showed that have a real different to continue to the next analysis of DMRT with test level 5% to locate the differences between treatments. The eels growth after feeding a mixture feed in the form of fish pellets, mealworms, and red alga, specifically: P1 (K 26.3167 gram; P2 20.3167 gram; P3 28.2500 gram; and P4 22.0000 gram. The eels survival rate, specifically P1 (K 26.67%; P2 33.33%; P3 30%; dan P4 26.67%. Furthemore, the exact composition that give the best effect of growth and survival rate to eels is 50% fish pellets, 45% mealworms and 5% red alga.

  12. A review on broodstock nutrition of marine pelagic spawners: the curious case of the freshwater eels (Anguilla spp.)

    DEFF Research Database (Denmark)

    Heinsbroek, L.T.N.; Støttrup, J.G.; Jacobsen, C.

    2013-01-01

    To sustain eel aquaculture, development of reproduction in captivity is vital. The aim of this review is to assess our current knowledge on the nutrition of broodstock eels in order to improve the quality of broodstock under farming conditions, drawing information from wild adult eels and other...... in the eggs of farmed eels were not detrimental. The total free amino acid amount and profile of eel eggs appears much different from other marine pelagic spawners. Nutritional intervention to influence egg composition seems feasible, but responsiveness of farmed eels to induced maturation might also require...

  13. Direct observations of American eels migrating across the continental shelf to the Sargasso Sea.

    Science.gov (United States)

    Béguer-Pon, Mélanie; Castonguay, Martin; Shan, Shiliang; Benchetrit, José; Dodson, Julian J

    2015-10-27

    Since inferring spawning areas from larval distributions in the Sargasso Sea a century ago, the oceanic migration of adult American eels has remained a mystery. No adult eel has ever been observed migrating in the open ocean or in the spawning area. Here, we track movements of maturing eels equipped with pop-up satellite archival tags from the Scotian Shelf (Canada) into the open ocean, with one individual migrating 2,400 km to the northern limit of the spawning site in the Sargasso Sea. The reconstructed routes suggest a migration in two phases: one over the continental shelf and along its edge in shallow waters; the second in deeper waters straight south towards the spawning area. This study is the first direct evidence of adult Anguilla migrating to the Sargasso Sea and represents an important step forward in the understanding of routes and migratory cues.

  14. Retention and effects of miniature transmitters in juvenile American eels

    Energy Technology Data Exchange (ETDEWEB)

    Mueller, Robert P.; Janak, Jill; Liss, Stephanie A.; Brown, Richard S.; Deng, Zhiqun; Harnish, Ryan A.

    2017-11-01

    This study was conducted to assess the effects of a non-functional acoustic micro transmitter (tag) on survival, tag loss, and swimming ability of juvenile American eels (Anguilla rostrata). The transmitter was designed for implantation through a < 3 mm opening into the body cavity of anguilliform fishes without the need for sutures. American eels used for the swimming performance study were 113–175 mm (N = 120). There were two treatment groups (tagged and non-tagged), each treatment was split into six size groups of 10 mm for testing. Potential transmitter effects on swimming performance were examined by comparing critical swimming speeds (Ucrit an index of prolonged swimming performance) for tagged and non-tagged eels. There was no significant difference in Ucrit between tagged and non-tagged eels for all of the size groups tested. Median Ucrits for tagged eels ranged from 50.2 cm/s for the smallest group tested (113–119 mm) to 63.9 cm/s for fish 141–150 mm in length. Non-tagged group median Ucrits ranged from 47.2 cm/s for the smallest group to 66.9 cm/s for the 141–150 mm group. An additional 26 eels (115–208 mm) were tagged and held for 38 d (without undergoing swimming performance tests) to determine the effects on survival and tag loss. There was no mortality during the holding period and the majority of the tag loss occurred after 20 days post-tagging, which is the current projected life of the tag. Our results indicate that micro acoustic tags can be successfully implanted in juvenile American eels with no apparent impacts to swimming ability, and would be a viable option for examining eel movement patterns in river systems and near hydroelectric facilities.

  15. Transcriptome analyses of Anguillicola crassus from native and novel hosts

    Directory of Open Access Journals (Sweden)

    Emanuel Heitlinger

    2014-11-01

    Full Text Available Anguillicola crassus is a swim bladder nematode of eels. The parasite is native to the Asian eel Anguilla japonica, but was introduced to Europe and the European eel Anguilla anguilla in the early 1980s. A Taiwanese source has been proposed for this introduction. In the new host in the recipient area, the parasite appears to be more pathogenic. As a reason for these differences, genetically fixed differences in infectivity and development between Taiwanese and European A.crassus have been described and disentangled from plasticity induced by different host environments. To explore whether transcriptional regulation is involved in these lifecycle differences, we have analysed a “common garden”, cross infection experiment, using deep-sequencing transcriptomics. Surprisingly, in the face of clear phenotypic differences in life history traits, we identified no significant differences in gene expression between parasite populations or between experimental host species. From 120,000 SNPs identified in the transcriptome data we found that European A. crassus were not a genetic subset of the Taiwanese nematodes sampled. The loci that have the major contribution to the European-Taiwanese population differentiation show an enrichment of synonymous and non-coding polymorphism. This argues against positive selection in population differentiation. However, genes involved in protein processing in the endoplasmatic reticulum membrane and genes bearing secretion signal sequences were enriched in the set of genes most differentiated between European and Taiwanese A. crassus. These genes could be a source for the phenotypically visible genetically fixed differences between European and Taiwanese A. crassus.

  16. Association between trichodiniasis in eel ( Anguilla anguilla ) and water quality in recirculation systems

    DEFF Research Database (Denmark)

    Madsen, H.C.K.; Buchmann, K.; Mellergaard, Stig

    2000-01-01

    Association between various water quality parameters and the infection level of Trichodina jadranica in cultured eels were examined in nine recirculation farms in Denmark. Production units suffering from trichodiniasis (n = 4) had relatively high contents of organic dry matter (13-65 mg l(-1)), low...... concentrations of nitrate (150-500 mg NO3 l(-1)) and high pH (6.2-7.4) in the process water compared to farms without Trichodina problems (n = 5), which had a relatively low load of organic dry matter (9-16 mg l(-1)), high nitrate concentration (250-900 mg NO3 l(-1)) and a low pH (5.3-6.9). More detailed studies...... of the effect of water parameters on the infection level were conducted in two production units suffering from frequent outbreaks of trichodiniasis. In one production unit, the high and highly varying content of organic dry matter (21- 83 mg l(-1)) was significantly and positively correlated (r = 0.37, p

  17. The Anguilla spp. migration problem: 40 million years of evolution and two millennia of speculation

    DEFF Research Database (Denmark)

    Righton, D.; Aarestrup, K.; Jellyman, D.

    2012-01-01

    , information on migratory behaviour is remarkably sketchy. The latest knowledge on the requirements for successful migration and field data on the migrations of adults and larvae are presented, how experiments on swimming efficiency have progressed the understanding of migration are highlighted...... and the challenges of swimming at depth considered. The decline of Anguilla spp. across the world is an ongoing concern for fisheries and environmental managers. New developments in the knowledge of eel migration will, in addition to solving a centuries old mystery, probably help to identify how this decline might...

  18. Low levels of persistent organic pollutants (POPs) in New Zealand eels reflect isolation from atmospheric sources

    International Nuclear Information System (INIS)

    Holmqvist, Niklas; Stenroth, Patrik; Berglund, Olof; Nystroem, Per; Olsson, Karin; Jellyman, Don; McIntosh, Angus R.; Larsson, Per

    2006-01-01

    Polychlorinated biphenyls (PCBs) and organic pesticides (i.e., DDTs) were measured in long finned eels (Anguilla dieffenbachii) in 17 streams on the west coast of South Island, New Zealand. Very low levels of PCBs and low levels of ppDDE were found. The concentrations of PCBs and ppDDE were not correlated within sites indicating that different processes determined the levels of the two pollutants in New Zealand eels. The PCBs probably originate from atmospheric transport, ppDDE levels are determined by land use and are higher in agriculture areas. The low contamination level of these aquatic systems seems to be a function of a low input from both long and short-range transport as well as few local point sources. No correlation could be found between lipid content and persistent organic pollutants (POPs) concentration (as shown in previous studies) in the eels which could be explained by low and irregular intake of the pollutants. - Low levels of PCBs found in New Zealand eels reflect isolation from atmospheric sources while DDTs levels are determined by land use

  19. Can lagrangian models reproduce the migration time of European eel obtained from otolith analysis?

    Science.gov (United States)

    Rodríguez-Díaz, L.; Gómez-Gesteira, M.

    2017-12-01

    European eel can be found at the Bay of Biscay after a long migration across the Atlantic. The duration of migration, which takes place at larval stage, is of primary importance to understand eel ecology and, hence, its survival. This duration is still a controversial matter since it can range from 7 months to > 4 years depending on the method to estimate duration. The minimum migration duration estimated from our lagrangian model is similar to the duration obtained from the microstructure of eel otoliths, which is typically on the order of 7-9 months. The lagrangian model showed to be sensitive to different conditions like spatial and time resolution, release depth, release area and initial distribution. In general, migration showed to be faster when decreasing the depth and increasing the resolution of the model. In average, the fastest migration was obtained when only advective horizontal movement was considered. However, faster migration was even obtained in some cases when locally oriented random migration was taken into account.

  20. Standardization of fertilization protocols for the European eel, Anguilla anguilla

    DEFF Research Database (Denmark)

    Butts, Ian; Sørensen, Sune Riis; Politis, Sebastian Nikitas

    2014-01-01

    of this research were to provide a rapid, accurate and precise method to quantify sperm density by examining the relationship between sperm density and absorbance by use of a spectrophotometer, determine the optimal number of sperm required to fertilize eggs in a controlled setting, and explore how long eggs...... are receptive to fertilization post-stripping. Mean sperm density and absorbance at 350nm were 1.54e+10±4.95e+9sperm/mL and 1.91±0.22nm, respectively. Regression analysis demonstrated a highly significant positive relationship between sperm density and absorbance using a spectrophotometer at 350nm (R2=0.94, p

  1. Shark predation on migrating adult american eels (Anguilla rostrata) in the Gulf of St. Lawrence

    DEFF Research Database (Denmark)

    Béguer-Pon, Mélanie; Benchetrit, José; Castonguay, Martin

    2012-01-01

    to identify the eel predators, we compared their vertical migratory behavior with those of satellite-tagged porbeagle shark and bluefin tuna, the only endothermic fishes occurring non-marginally in the Gulf of St. Lawrence. We accurately distinguished between tuna and shark by using the behavioral criteria....... Surprisingly, of the seven tags that successfully transmitted archived data, six were ingested by warm-gutted predators, as observed by a sudden increase in water temperature. Gut temperatures were in the range of 20 to 25°C--too cold for marine mammals but within the range of endothermic fish. In order...... generated by comparing the diving behavior of these two species with those of our unknown predators. Depth profile characteristics of most eel predators more closely resembled those of sharks than those of tuna. During the first days following tagging, all eels remained in surface waters and did not exhibit...

  2. On the way to successful European eel larval rearing: Impact of biophysical conditions and gamete quality

    DEFF Research Database (Denmark)

    Sørensen, Sune Riis

    The European eel is a widely distributed fish species of economic and cultural importance. It inhabits both coastal and freshwater systems, and is targeted by fisheries and treasured as food item. Although eels are reared in aquaculture, this industry relies solely of wild‐caught juvenile glass...... the European continent, they are in an immature stage, and they do not start migration and maturation until the silvering stage. This stage is however tightly controlled by brain and pituitary hormones, preventing maturation of gonads remote from their natural breeding area. This hormonal inhibition...... and larval culture. Our fertilisation procedures initially applied spermatocrit as for sperm quantification technique to standardise sperm:egg ratio. Although being a practical method, it featured moderate precision. Spectrophotometry in contrast, showed high precision in addition to being a fast...

  3. Influence of Temperature, Environmental Salinity and Fasting on the Patterns of Fatty Acid Synthesized by Gills and Liver of the European Eel (Anguilla Anguilla)

    DEFF Research Database (Denmark)

    Hansen, Heinz Johs. Max; Abraham, S.

    1983-01-01

    A rise in temperature on the average from 8 to 28 degrees C resulted in an enhanced relative incorporation of 1-14Cacetate into saturated fatty acids in liver tissue. The same effect was seen in gill tissue, but only after incubation in vitro and when the precursor was injected into the eel. When 1...... in the gills, due to the labelled precursor itself taking part in biological ion transport when it is added to the water. It would appear that palmitoleic acid plays a special role in the function of the salt transport cell. When 1-14Cacetate was added to the water in the incubation tank...... there was a significantly enhanced percentage incorporation into saturated gill fatty acids in fresh water relative to sea water. Fasting led to less relative incorporation of 1-14Cacetate into saturated liver fatty acids in vitro....

  4. Neurotransmitters and putative neuromodulators in the gut of Anguilla anguilla (L.. Localizations in the enteric nervous and endocrine systems

    Directory of Open Access Journals (Sweden)

    A Veggetti

    2009-12-01

    Full Text Available The gut of silver eels (Anguilla anguilla L. was investigated in order to describe both the cholinergic and adrenergic intramural innervations, and the localization of possible accessory neuromediators. Histochemical reactions for the demonstration of nicotinamide adenine dinucleotide phosphate, reduced form-(NADPH-diaphorase and acetylcholinesterese (AChEase were performed, as well as the immunohistochemical testing of tyrosine hydroxylase, met-enkephalin, substance P, calcitonin gene-related peptide (CGRP, bombesin, vasoactive intestinal peptide (VIP, neuropeptide Y (NPY, somatostatin, cholecystokinin-octapeptide (CCK-8, serotonin, cholineacetyltransferase. The results evidenced a different pattern in comparison with other vertebrates, namely mammals, and with other fish. Both NADPH-diaphorase and AChEase activities were histochemically detected all along the gut in the myenteric plexus, the inner musculature and the propria-submucosa. Tyrosine hydroxylase immunoreactivity was observed in the intestinal tract only, both in the myenteric plexus and in the inner musculature. Several neuropeptides (metenkephalin, CGRP, bombesin, substance P, VIP, NPY, somatostatin were, in addition, detected in the intramural innervation; some of them also in epithelial cells of the diffuse endocrine system (met-enkephalin, substance P, NPY, somatostatin. Serotonin was only present in endocrine cells. Tyrosine hydroxylase immunoreactivity was present in localizations to those of similar NADPHdiaphorase- reactivity, and in the same nerve bundles in which substance P- and CGRP-likeimmunoreactivities were detectable in the intestinal tract. In addition, NADPH-diaphorase-reactive neurons showed an anatomical relationship with AChEase-reactive nerve terminals, and a similar relationship existed between the latter and substance P-like immunoreactivity.

  5. Proceedings of a workshop on American Eel passage technologies

    Science.gov (United States)

    Haro, Alexander J.

    2013-01-01

    Recent concerns regarding a decline in recruitment of American eels (Anguilla rostrata) have prompted efforts to restore this species to historic habitats by providing passage for both upstream migrant juveniles and downstream migrant adults at riverine barriers, including low-head and hydroelectric dams (Castonguay et al. 1994, Haro et al. 2000). These efforts include development of management plans and stock assessment reviews in both the US and Canada (COSEWIC 2006, Canadian Eel Working Group 2009, DFO 2010, MacGregor et al. 2010, ASMFC 2000, ASMFC 2006, ASMFC 2008, Williams and Threader 2007), which target improvement of upstream and downstream passage for eels, as well as identification and prioritization of research needs for development of new and more effective passage technologies for American eels. Traditional upstream fish passage structures, such as fishways and fish lifts, are often ineffective passing juvenile eels, and specialized passage structures for this species are needed. Although designs for such passage structures are available and diverse (Knights and White 1998, Porcher 2002, FAO/DVWK 2002, Solomon and Beach 2004a,b, Environment Agency UK 2011), many biologists, managers, and engineers are unfamiliar with eel pass design and operation, or unaware of the technical options available for upstream eel passage, Better coordination is needed to account for eel passage requirements during restoration efforts for other diadromous fish species. Also, appropriately siting eel passes at hydropower projects is critical, and siting can be difficult and complex due to physical restrictions in access to points of natural concentrations of eels, dynamic hydraulics of tailrace areas, and presence of significant competing flows from turbine outfalls or spill. As a result, some constructed eel passes are sited poorly and may pass only a fraction of the number of eels attempting to pass the barrier. When sited and constructed appropriately, however, eel passes

  6. The temperature challenges on cardiac performance in winter-quiescent and migration-stage eels Anguilla anguilla

    DEFF Research Database (Denmark)

    Methling, C.; Steffensen, J. F.; Skov, Peter Vilhelm

    2012-01-01

    , and following acute ± 10 °C temperature changes. The time-course of contraction, and thus maximal attainable heart rates, was greatly influenced by working temperature, but was independent of acclimation history. The absolute force of contraction and power production (i.e. the product of force and stimulation...... frequency) was significantly influenced by acute temperature decrease from 20 °C to 10 °C. The role of adrenaline as a modulator of contraction force, power production, rates of contraction and relaxation, and minimum time in contraction was assessed. Increased adrenergic tonus elicited a positive inotropic......, temperature-dependent response, but did not influence twitch duration. This suggests that adrenaline acts as an agent in maintaining an adequate contractile force following temperature challenges. A significant increased relative ventricular mass was observed in 0 °C and 10 °C-acclimated eels compared to 20...

  7. Mercury content in Anguillicola crassus (Nematoda) and its host Anguilla anguilla

    Czech Academy of Sciences Publication Activity Database

    Palíková, M.; Baruš, Vlastimil

    2003-01-01

    Roč. 72, č. 2 (2003), s. 289-294 ISSN 0001-7213 R&D Projects: GA ČR GA524/03/0061 Institutional research plan: CEZ:AV0Z6093917 Keywords : Nematoda * parasites * Anguilla anguilla Subject RIV: EG - Zoology Impact factor: 0.336, year: 2003 http://vfu-www.vfu.cz/acta-vet/vol72/pdf/72_289.pdf

  8. Do North Atlantic eels show parallel patterns of spatially varying selection?

    DEFF Research Database (Denmark)

    Ulrik, Malene G.; Pujolar, Jose Martin; Ferchaud, Anne-Laure

    2014-01-01

    was used to genotype European eel individuals (glass eels) from 8 sampling locations across the species distribution. We tested for single-generation signatures of spatially varying selection in European eel by searching for elevated genetic differentiation using F-ST-based outlier tests and by testing...... for significant associations between allele frequencies and environmental variables. Results: We found signatures of possible selection at a total of 11 coding-gene SNPs. Candidate genes for local selection constituted mainly genes with a major role in metabolism as well as defense genes. Contrary to what has...... been found for American eel, only 2 SNPs in our study correlated with differences in temperature, which suggests that other explanatory variables may play a role. None of the genes found to be associated with explanatory variables in European eel showed any correlations with environmental factors...

  9. Passage of downstream migrant American eels through an airlift-assisted deep bypass

    Science.gov (United States)

    Haro, Alexander J.; Watten, Barnaby J.; Noreika, John

    2016-01-01

    Traditional downstream guidance and bypass facilities for anadromous fishes (i.e., surface bypasses, surface guidance structures, and behavioral barriers) have frequently been ineffective for anguillid eels. Because eels typically spend the majority of their time near the bottom in the vicinity of intake structures, deep bypass structures with entrances near the bottom hold promise for increased effectiveness, thereby aiding in the recovery of this important species. A new design of a deep bypass system that uses airlift technology (the Conte Airlift Bypass) to induce flow in a bypass pipe was tested in a simulated intake entrance environment under controlled laboratory conditions. Water velocities of 0.9–1.5 m s−1 could be generated at the bypass entrance (opening with 0.073 m2 area), with corresponding flows through the bypass pipe of 0.07–0.11 m3 s−1. Gas saturation and hydrostatic pressure within the bypass pipe did not vary appreciably from a control (no air) condition under tested airflows. Migratory silver-phase American eels (Anguilla rostrata) tested during dark conditions readily located, entered, and passed through the bypass; initial avoidance rates (eels approaching but not entering the bypass entrance) were lower at higher entrance velocities. Eels that investigated the bypass pipe entrance tended to enter headfirst, but those that then exited the pipe upstream did so more frequently at lower entrance velocities. Eels appeared to swim against the flow while being transported downstream through the pipe; median transit times through the bypass for each test velocity ranged from 5.8 to 12.2 s, with transit time decreasing with increasing entrance velocity. Eels did not show strong avoidance of the vertical section of the pipe which contained injected air. No mortality or injury of bypassed eels was observed, and individual eels repeatedly passed through the bypass at rates of up to 40 passes per hour, suggesting that individuals do not

  10. Reliability of non-lethal assessment methods of body composition and energetic status exemplified by applications to eel (Anguilla anguilla) and carp (Cyprinus carpio)

    DEFF Research Database (Denmark)

    Klefoth, Thomas; Skov, Christian; Aarestrup, Kim

    2013-01-01

    tNon-lethal assessments of proximate body composition of fish can help unravelling the physiologicaland condition-dependent mechanisms of individual responses to ecological challenges. Common non-lethal methods designed to index nutrient composition in fish include the relative condition factor (Kn......),bioelectric impedance-based assessments of body composition (BIA), and microwave-based “fat” meters(FM). Previous studies have revealed mixed findings as to the reliability of each of these. We compared theperformance of Kn, BIA and FM at different temperatures to predict energetic status of the whole bodiesof live eel...... approach isthe most suitable method to non-lethally estimate energetic status in both, carp and eel, whereas BIA is oflimited use for energetic measurements in the same species, in contrast to other reports in the literature...

  11. Molecular cloning of Japanese eel Anguilla japonica TNF-α and characterization of its expression in response to LPS, poly I:C and Aeromonas hydrophila infection

    Science.gov (United States)

    Feng, Jianjun; Guan, Ruizhang; Guo, Songlin; Lin, Peng; Zadlock, Frank

    2014-09-01

    As a potent pleiotropic cytokine, tumor necrosis factor-alpha (TNF-α) plays an important role in innate immune responses. The cDNA sequence and genomic structure of the TNF-α gene ( Aj TNF-α) in the Japanese eel ( Anguilla japonica) were identified and characterized. The full-length AjTNF-α cDNA was 1 546 bp, including a 5'-untranslated region (UTR) of 13 bp, a 3'-UTR of 879 bp and an open reading frame of 654 bp encoding a protein of 218 amino acids. The full-length genomic sequence of AjTNF-α was 2 392 bp and included four exons and three introns. The putative AjTNF-α protein contained TNF family signature motifs, including a protease cleavage site, a transmembrane domain and two conserved cysteine residues. Quantitative real-time reverse transcription PCR analysis revealed AjTNF-α expression in a wide range of tissues, with predominant expression in blood and liver. Lower levels of expression were seen in spleen, gills, kidney, intestine, heart, and skin, with very low levels in muscle. The modulation of AjTNF-α expression after injection of eels with lipopolysaccharide (LPS), the viral mimic, poly I:C, or Aeromonas hydrophila was assessed in blood, liver, and kidney. In blood, TNF-α mRNA levels increased rapidly and then rapidly decreased after stimulation with LPS, poly I:C or A. hydrophila. However, the response to LPS and A. hydrophila peaked at 6 h while for poly I:C the peak was at 12 h. In liver, after injection with A. hydrophila, an up- and down-regulation of AjTNF-α expression occurred twice, peaking at 6 h and 24 h, respectively. No remarkable increase of AjTNF-α expression appeared in liver until 72 h after LPS or poly I:C treatment. In kidney, AjTNF-α expression increased significantly only at 72 h post-stimulation with LPS or A. hydrophila. Our results suggest that AjTNF-α plays an important role in fish in the defense against viral and bacterial infection.

  12. Effect of earthworm (Lumbricus rubellus) in feed formulation to improve fatty acids profile in eel (Anguilla bicolor) meat

    Science.gov (United States)

    Farah, K.; Gunawan, I. R.; Putra, G. B.; Agustono; Lokapirnasari, W. P.; Lamid, M.; Masithah, E. D.; Nurhajati, T.; Rozi

    2018-04-01

    Eel requires unsaturated fatty acids of linolenic acid for growth. Which can be supplied from earthworms. In this study, addition of earthworm in formulation feed aimsed to improve the fatty acid profile eel meat. This research used experimental method and randomized complete design method with five treatments. Each treatment was repeated four times. The use of earthworms in feeding treatment formulation was done for 21 days with different level i.e: 0 % (P0), 25 % (P1), 50 % (P2), 75 % (P3) and 100 % (P4). The result showed that the addition of eartworm significantly influenced the omega 3 contents (EPA & DHA) of eel meat.

  13. A new species of Hysterothylacium (Nematoda: Anisakidae) from the giant mottled eel Anguilla marmorata in South Africa

    Czech Academy of Sciences Publication Activity Database

    Moravec, František; Taraschewski, H.; Appelhoff, D.; Weyl, O.

    2012-01-01

    Roč. 49, č. 3 (2012), s. 174-180 ISSN 0440-6605 R&D Projects: GA ČR GBP505/12/G112 Institutional research plan: CEZ:AV0Z60220518 Keywords : Hysterothylacium * Anguilla * South Africa Subject RIV: GJ - Animal Vermins ; Diseases, Veterinary Medicine Impact factor: 0.783, year: 2012 http://link.springer.com/article/10.2478%2Fs11687-012-0035-9

  14. The mechanism for primordial germ-cell migration is conserved between Japanese eel and zebrafish.

    Directory of Open Access Journals (Sweden)

    Taiju Saito

    Full Text Available Primordial germ cells (PGCs are segregated and specified from somatic cells during early development. These cells arise elsewhere and have to migrate across the embryo to reach developing gonadal precursors. Several molecules associated with PGC migration (i.e. dead-end, nanos1, and cxcr4 are highly conserved across phylum boundaries. However, since cell migration is a complicated process that is regulated spatially and temporally by multiple adaptors and signal effectors, the process is unlikely to be explained by these known genes only. Indeed, it has been shown that there are variations in PGC migration pattern during development among teleost species. However, it is still unclear whether the actual mechanism of PGC migration is conserved among species. In this study, we studied the migration of PGCs in Japanese eel (Anguilla japonica embryos and tested the migration mechanism between Japanese eel and zebrafish (Danio rerio for conservation, by transplanting eel PGCs into zebrafish embryos. The experiments showed that eel PGCs can migrate toward the gonadal region of zebrafish embryos along with endogenous PGCs, even though the migration patterns, behaviors, and settlements of PGCs are somewhat different between these species. Our results demonstrate that the migration mechanism of PGCs during embryonic development is highly conserved between these two distantly related species (belonging to different teleost orders.

  15. Distribution of perfluorinated compounds in aquatic systems in The Netherlands

    NARCIS (Netherlands)

    Kwadijk, C.J.A.F.; Korytar, P.; Koelmans, A.A.

    2010-01-01

    The distribution of 15 perfluorinated compounds (PFCs) among eel (Anguilla anguilla), sediment, and water was investigated for 21 locations in The Netherlands. Furthermore, for perfluorooctanesulfonate (PFOS), a 30 year time series was measured for three locations using historical eel samples. These

  16. Complete genome sequence and phylogenetic analyses of an aquabirnavirus isolated from a diseased marbled eel culture in Taiwan.

    Science.gov (United States)

    Wen, Chiu-Ming

    2017-08-01

    An aquabirnavirus was isolated from diseased marbled eels (Anguilla marmorata; MEIPNV1310) with gill haemorrhages and associated mortality. Its genome segment sequences were obtained through next-generation sequencing and compared with published aquabirnavirus sequences. The results indicated that the genome sequence of MEIPNV1310 contains segment A (3099 nucleotides) and segment B (2789 nucleotides). Phylogenetic analysis showed that MEIPNV1310 is closely related to the infectious pancreatic necrosis Ab strain within genogroup II. This genome sequence is beneficial for studying the geographic distribution and evolution of aquabirnaviruses.

  17. Spawning sites of the Japanese eel in relation to oceanographic structure and the West Mariana Ridge.

    Science.gov (United States)

    Aoyama, Jun; Watanabe, Shun; Miller, Michael J; Mochioka, Noritaka; Otake, Tsuguo; Yoshinaga, Tatsuki; Tsukamoto, Katsumi

    2014-01-01

    The Japanese eel, Anguilla japonica, spawns within the North Equatorial Current that bifurcates into both northward and southward flows in its westward region, so its spawning location and larval transport dynamics seem important for understanding fluctuations in its recruitment to East Asia. Intensive research efforts determined that Japanese eels spawn along the western side of the West Mariana Ridge during new moon periods, where all oceanic life history stages have been collected, including eggs and spawning adults. However, how the eels decide where to form spawning aggregations is unknown because spawning appears to have occurred at various latitudes. A salinity front formed from tropical rainfall was hypothesized to determine the latitude of its spawning locations, but an exact spawning site was only found once by collecting eggs in May 2009. This study reports on the collections of Japanese eel eggs and preleptocephali during three new moon periods in June 2011 and May and June 2012 at locations indicating that the distribution of lower salinity surface water or salinity fronts influence the latitude of spawning sites along the ridge. A distinct salinity front may concentrate spawning south of the front on the western side of the seamount ridge. It was also suggested that eels may spawn at various latitudes within low-salinity water when the salinity fronts appeared unclear. Eel eggs were distributed within the 150-180 m layer near the top of the thermocline, indicating shallow spawning depths. Using these landmarks for latitude (salinity front), longitude (seamount ridge), and depth (top of the thermocline) to guide the formation of spawning aggregations could facilitate finding mates and help synchronize their spawning.

  18. Rhabdochona (Rhabdochona) keralaensis sp nov (Rhabdochonidae) and some other nematodes in the Indian mottled eel Anguilla bengalensis bengalensis from India

    Czech Academy of Sciences Publication Activity Database

    Moravec, František; Sheeba, S.; Kumar, A. B.

    2012-01-01

    Roč. 57, č. 1 (2012), 74-82 ISSN 1230-2821 R&D Projects: GA MŠk LC522 Institutional research plan: CEZ:AV0Z60220518 Keywords : Rhabdochona * Anguilla * India Subject RIV: GJ - Animal Vermins ; Diseases, Veterinary Medicine Impact factor: 1.000, year: 2012

  19. Impact of a short-term exposure to tributyl phosphate on morphology, physiology and migratory behaviour of European eels during the transition from freshwater to the marine environment

    DEFF Research Database (Denmark)

    Privitera, Lucia; Aarestrup, Kim; Moore, Andy

    2013-01-01

    Migrating silver European eels were exposed for 5 days in a laboratory to an environmental level of tributyl phosphate (TBP), tagged with acoustic transmitters and released below the Tange hydropower station, on the River Gudenaa, Denmark. The subsequent movements of the eels were monitored as th...

  20. Schooling reduces energy consumption in swimming male European eels, Anguilla anguilla L.

    NARCIS (Netherlands)

    Burgerhout, E.; Tudorache, C.; Brittijn, S.A.; Palstra, A.P.; Dirks, R.P.; Thillart, G.E.E.J.M.

    2013-01-01

    During migration, swimming in schools provides fish with a number of behavioural and ecological advantages, including increased food supply and reduced predation risk. Previous work shows that carangiform and tunniform swimming result in energetic advantages for individuals using a diamond swimming

  1. The role of volume-sensitive ion transport systems in regulation of epithelial transport

    DEFF Research Database (Denmark)

    Hoffmann, Else Kay; Schettino, T; Marshall, W S

    2007-01-01

    This review focuses on using the knowledge on volume-sensitive transport systems in Ehrlich ascites tumour cells and NIH-3T3 cells to elucidate osmotic regulation of salt transport in epithelia. Using the intestine of the European eel (Anguilla anguilla) (an absorptive epithelium of the type...... on the apical side and the Na+/K+ ATPase, NKCC1 and a K+ channel on the basolateral side. Osmotic control of Cl- secretion across the operculum epithelium includes: (i) hyperosmotic shrinkage activation of NKCC1 via PKC, MLCK, p38, OSR1 and SPAK; (ii) deactivation of NKCC by hypotonic cell swelling...

  2. Micro-PIXE study of whole otolith of Anguilla japonica at elver stage

    International Nuclear Information System (INIS)

    Zheng, Y.; Guo, H.; Wei, K.; Tang, W.; Satoh, T.; Ohkubo, T.; Yamazaki, A.; Takano, K.; Kamiya, T.; Shen, H.; Yang, M.; Mi, Y.

    2010-01-01

    Strontium and calcium contents, within the otolith of Anguilla japonica, were measured by external micro-PIXE. According to the measured metamorphic checks, each otolith was divided into three stages. Comparing with the Sr:Ca ratios in stage 2, the ratios in stage 1 had two different trends. Among these fish, it may reflect their maternal condition was not the same. The ratios in stage 3 which was corresponding to the estuarine habitat were smaller than that in any other stage which was corresponding to the ocean habitat in each otolith. Suggested by our results, the eels from the spawning site may separate into two groups when they are near to the south of Taiwan, and then move to the different estuaries in China. It could be proposed that, in general, the migration direction is from south to north along the east coast in China.

  3. Micro-PIXE study of whole otolith of Anguilla japonica at elver stage

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, Y. [Applied Ion Beam Physics Laboratory, Institute of Modern Physics, Fudan University, Shanghai 200433 (China); Guo, H.; Wei, K.; Tang, W. [Institute of Life Science, Shanghai Fisheries University, Shanghai 200090 (China); Satoh, T.; Ohkubo, T.; Yamazaki, A.; Takano, K.; Kamiya, T. [Takasaki Advanced Radiation Research Institute, JAEA, Gunma 370-1292 (Japan); Shen, H., E-mail: haoshen@fudan.edu.c [Applied Ion Beam Physics Laboratory, Institute of Modern Physics, Fudan University, Shanghai 200433 (China); Yang, M.; Mi, Y. [Applied Ion Beam Physics Laboratory, Institute of Modern Physics, Fudan University, Shanghai 200433 (China)

    2010-06-15

    Strontium and calcium contents, within the otolith of Anguilla japonica, were measured by external micro-PIXE. According to the measured metamorphic checks, each otolith was divided into three stages. Comparing with the Sr:Ca ratios in stage 2, the ratios in stage 1 had two different trends. Among these fish, it may reflect their maternal condition was not the same. The ratios in stage 3 which was corresponding to the estuarine habitat were smaller than that in any other stage which was corresponding to the ocean habitat in each otolith. Suggested by our results, the eels from the spawning site may separate into two groups when they are near to the south of Taiwan, and then move to the different estuaries in China. It could be proposed that, in general, the migration direction is from south to north along the east coast in China.

  4. Changes in body weight and eye size in female European eel kept in fresh and salt water

    Directory of Open Access Journals (Sweden)

    Joanna Nowosad

    2014-05-01

    Full Text Available The eel is a catadromous fish which spends most of its life in freshwater and adults swim to the Sargasso Sea region to spawn. While preparing for the reproductive process, eels undergo a metamorphosis to become what is called silver eel; a process involving changes in the colour and weight of the body and an increase in the eye size. These are indicators of fish maturity and they facilitate the selection of fish for reproduction under controlled conditions. During this study, changes in the body weight (BW and eye size in female European eel were observed while being given weekly hormonal injections of 20 mg kg–1 carp pituitary homogenate and kept in 15°C freshwater and in 15°C saltwater with a salinity of 32-33‰. Fish kept in saltwater but not subjected to hormonal stimulation were used as a control group. Furthermore, after the experiment was finished, females in the control group were kept for next 5 months, with the same environmental parameters maintained. Differences between the treated groups were observed as early as week 4 of the experiment. An increase in fish BW was observed in fish kept both in salt and freshwater which were subjected to hormonal stimulation. On the other hand, changes in eye size were observed in the fish kept in saltwater, both in those hormonally stimulated and otherwise. The eye diameter in the fish kept in fresh after hormonal stimulation did not change significantly.

  5. Effect of TBT and PAHs on CYP1A, AhR and Vitellogenin Gene Expression in the Japanese Eel, Anguilla japonica.

    Science.gov (United States)

    Choi, Min Seop; Kwon, Se Ryun; Choi, Seong Hee; Kwon, Hyuk Chu

    2012-12-01

    Gene expressions of cytochrome P4501A (CYP1A), aryl hydrocarbon receptor (AhR) and vitellogenin (Vg) by endocrine disruptors, benzo[α]pyrene (B[a]P) and tributyltin (TBT) were examined in cultured eel hepatocytes which were isolated from eels treated previously with B[a]P (10 mg/kg) or estradiol-17β (20 mg/kg) in vivo, and the relationship between CYP1A, AhR and Vg genes were studied. When the cultured eel hepatocytes were treated with B[a]P (10(-6)-10(-5) M) the gene expressions of CYP1A and AhR were enhanced in a concentration-dependent manner. However, when treated with TBT (10(-9)-10(-5) M) the gene expressions of CYP1A and AhR were suppressed at high concentrations (10(-6)-10(-5) M), while having no effects at low concentrations (10(-9)-10(-7) M). Gene expression of Vg was also suppressed by TBT in a concentration-dependent manner in cultured eel hepatocytes which was previously treated in vivo with estradiol-17β.

  6. Influence of the North Atlantic oceanograghic and climatic parameters on the Spanish European Eel population recruitment: relationships in the past and for a future climate change

    Science.gov (United States)

    Ribalaygua, Jaime; Pórtoles, Javier; Monjo, Robert; Díaz, Estíbaliz; Korta, María; Chust, Guillem

    2016-04-01

    The status of the European eel population is critical.; the annual recruitment of glass eel to European waters in 2015 is 1.2% of the 1960-1979 level in the 'North Sea' area, and 8.4% in the rest of Europe (ICES 2015) . There are a number of anthropogenic impacts potentially affecting eel population including commercial exploitation, habitat loss, dam and weir construction, hydropower, pumping stations and surface water abstractions. Furthermore, the first eel stages and larval migration and marine survival are heavily influenced by oceanic and climatic factors since the species breeds in the Sargasso Sea and migrates to the continental shelf of the Atlantic coast of Europe and North Africa. Therefore, the study of the relations between recruitment and oceanic conditions may allow to study the potential effect of climatic change on the future eel recruitment and therefore stock. In the present study, the relation between glass eel recruitment and oceanic and climatic factors has been studied. Historic glass eel catches data beginning in the 50s from two Mediterranean and two Atlantic estuaries have been used as a proxy of recruitment. The relation of catches with the main oceanographic and climatic factors identified in the literature was established using an ocean reanalysis, the Simple Ocean Data Assimilation (SODA) and determined which variables are significantly related to the number of catches. The analysis shows significant relationships between catches and oceanic (Surface Downward Stress, Sea Water Temperature and Sea Water Velocity) and atmospheric (NAO Index, AMO Index) variables. Subsequently, we applied the results of three climate models (GFDL-ESM2M, CanESM2 and CNRM-CM5), associated with the Coupled Model Intercomparison Project Phase 5 (CMIP5) under two simulations of climate change (RCP4.5 and RCP8.5), both associated with the 5th Assessment Report of the IPCC, for possible future influences on the eel. This research was funded by the Spanish

  7. Summer use of the tidal freshwaters of the River Seine by three estuarine fish: Coupling telemetry and GIS spatial analysis

    Science.gov (United States)

    Le Pichon, C.; Coustillas, J.; Zahm, A.; Bunel, M.; Gazeau-Nadin, C.; Rochard, E.

    2017-09-01

    Acoustic telemetry and GIS-based spatial analysis were used to investigate the summer habitat use and movement patterns of three fish species in the tidal freshwaters of the Seine estuary (France). Experimental displacement of tagged individuals of thin-lipped grey mullet (Liza ramada), European eel (Anguilla anguilla), and common bream (Abramis brama) were conducted to test for their spatial fidelity and home range establishment. Most tagged individuals (95%) successfully returned to their previously occupied capture site, showing spatial homing abilities. The studied upstream tidal freshwater segment of the Seine estuary was regularly used by grey mullet as a part of its larger summer home range, while European eel and common bream were resident in this segment. The fidelity of eel to small nocturnal refuges and the regular use of intertidal waterbodies at high tide by grey mullet and bream suggested that they possess a capacity of acquiring spatial memory of habitats in a fluctuating environment. Importantly, the scale of movements travelled by each species was positively related to tidal phase. Grey mullet and bream, both visual feeders, exhibited short-term tidal movements to known habitats, providing food resources and contiguous resting habitat suggesting that they have shown behavioural strategies adaptive to fluctuating environments. Eel, in contrast, was found to have a different strategy strongly related to diel dynamics: it stayed in subtidal habitats rich in refuges that remained available at low tide. The results of this study emphasize the importance of restoring intertidal waterbodies and the relevance of considering the availability of adjacent subtidal habitats providing refuge at low tides.

  8. Effects of exercise and temperature on geosmin excretion by European eel (Anguilla anguilla)

    NARCIS (Netherlands)

    Schram, E.; Schrama, J.W.; Kusters, K.; Kwadijk, C.J.A.F.; Palstra, A.P.

    2016-01-01

    The presence of geosmin in fish products causes an earthy or musty off-flavour. To avoid economic damage resulting from market entrance of off-flavoured fish products, fish farmers utilize the reversibility of geosmin uptake to depurate the off-flavours from their fish crops by holding them in clean

  9. Downstream passage and impact of turbine shutdowns on survival of silver American Eels at five hydroelectric dams on the Shenandoah River

    Science.gov (United States)

    Eyler, Sheila; Welsh, Stuart A.; Smith, David R.; Rockey, Mary

    2016-01-01

    Hydroelectric dams impact the downstream migrations of silver American Eels Anguilla rostrata via migratory delays and turbine mortality. A radiotelemetry study of American Eels was conducted to determine the impacts of five run-of-the-river hydroelectric dams located over a 195-km stretch of the Shenandoah River, Virginia–West Virginia, during fall 2007–summer 2010. Overall, 96 radio-tagged individuals (mean TL = 85.4 cm) migrated downstream past at least one dam during the study. Most American Eels passed dams relatively quickly; over half (57.9%) of the dam passage events occurred within 1 h of reaching a dam, and most (81.3%) occurred within 24 h of reaching the dam. Two-thirds of the dam passage events occurred via spill, and the remaining passage events were through turbines. Migratory delays at dams were shorter and American Eels were more likely to pass via spill over the dam during periods of high river discharge than during low river discharge. The extent of delay in migration did not differ between the passage routes (spill versus turbine). Twenty-eight American Eels suffered turbine-related mortality, which occurred at all five dams. Mortality rates for eels passing through turbines ranged from 15.8% to 40.7% at individual dams. Overall project-specific mortality rates (with all passage routes combined) ranged from 3.0% to 14.3%. To protect downstream-migrating American Eels, nighttime turbine shutdowns (1800–0600 hours) were implemented during September 15–December 15. Fifty percent of all downstream passage events in the study occurred during the turbine shutdown period. Implementation of the seasonal turbine shutdown period reduced cumulative mortality from 63.3% to 37.3% for American Eels passing all five dams. Modifying the turbine shutdown period to encompass more dates in the spring and linking the shutdowns to environmental conditions could provide greater protection to downstream-migrating American Eels.

  10. Bicarbonate secreted from the pancreas contributed to the formation of Ca precipitates in Japanese eel, Anguilla japonica.

    Science.gov (United States)

    Mekuchi, Miyuki; Watanabe, Soichi; Kaneko, Toyoji

    2013-01-01

    Marine teleosts produce Ca precipitates in the intestine as a product of osmoregulation. Ca precipitates are formed by a chemical reaction of Mg(2+) and Ca(2+) derived from ingested seawater with bicarbonate (HCO(3)(-)). It has been reported that HCO(3)(-) originates from the intestine; however, the pancreas is predicted to be another organ that may supply HCO(3)(-) to the intestinal tract. In the present study, the pancreas was surgically removed from Japanese eel to confirm its contribution to Ca precipitate formation. Pancreatectomized eel produced significantly less Ca precipitates than control eel in seawater, indicating that HCO(3)(-) from the pancreas contributes substantially to the formation of Ca precipitates. To further examine the molecular mechanisms of HCO(3)(-) secretion, we cloned cDNAs encoding HCO(3)(-) transporters and identified those transporters that elevated their mRNA expression in the intestine and pancreas following seawater transfer. In the intestine, mRNA expression of Slc26a6A was increased shortly after seawater transfer, whereas Slc26a1 mRNA expression increased gradually following seawater transfer. In the pancreas, Slc26a3 mRNA expression was high during the early stage of seawater acclimation, whereas Slc26a1 expression increased gradually after transfer to seawater. In the intestine and pancreas, therefore, both transient and progressively increasing types of HCO(3)(-) transporters are likely to be involved in HCO(3)(-) secretion into the intestinal lumen in a coordinated manner. Copyright © 2012 Wiley Periodicals, Inc.

  11. First production of larvae using cryopreserved sperm: Effects of preservation temperature and cryopreservation on European eel sperm fertilization capacity

    DEFF Research Database (Denmark)

    Asturiano, J.F.; Sørensen, Sune Riis; Perez, L.

    2016-01-01

    Sperm cryopreservation is a useful tool in captive fish reproduction management, that is to synchronize gamete production, especially in the case of species as the European eel, where the time of female spawning readiness is unpredictable. Several protocols to cryopreserve sperm of this species....... Fertilization of two egg batches was attempted. Diluted sperm caused a similar percentage of fertilized eggs and a similar number of embryos and larvae, independently of storage temperature (4 or 20°C). The cryopreserved sperm resulted in a lower percentage of fertilized eggs, but embryos developed and a few...... larvae ('cryolarvae') were obtained 55 h after fertilization in one of the two egg batches. This result evidences that the tested cryopreservation protocol is applicable for eel reproduction management, although improvements will be required to enhance fertilization success...

  12. Eel attacks – A new tool for assessing European eel (Anguilla anguilla) abundance and distribution patterns with gillnet sampling

    Czech Academy of Sciences Publication Activity Database

    Prchalová, Marie; Kubečka, Jan; Říha, Milan; Čech, Martin; Jůza, Tomáš; Ketelaars, H. A. M.; Kratochvíl, Michal; Mrkvička, Tomáš; Peterka, Jiří; Vašek, Mojmír; Wagenvoort, A. J.

    2013-01-01

    Roč. 43, č. 3 (2013), s. 194-202 ISSN 0075-9511 R&D Projects: GA AV ČR(CZ) IAA600960901; GA ČR(CZ) GPP505/12/P647 Institutional support: RVO:60077344 Keywords : beach seine * trawl * fish-monitoring technique * species selectivity * feeding strategy * spatial distribution Subject RIV: EH - Ecology, Behaviour Impact factor: 1.655, year: 2013

  13. Morphological, anatomical and histological studies on the olfactory organs and eyes of teleost fish: Anguilla anguilla in relation to its feeding habits

    Directory of Open Access Journals (Sweden)

    K.I. Atta

    2013-05-01

    The average olfactory surface area is about 590.9% of the retinal area. Thus A. anguilla is a macrosmatic species “nose-fish” in which olfaction plays an important role in its feeding habit. It is noticed that, the photoreceptor cell layer in A. anguilla (bottom feeder is made up only of rod cells.

  14. Is humane slaughter of fish possible for industry?

    NARCIS (Netherlands)

    Vis, van de J.W.; Kestin, S.; Robb, D.; Oehlenschlaeger, J.; Lambooij, E.; Kuhlmann, H.; Kloosterboer, K.

    2003-01-01

    The objective was to evaluate industrial and research slaughter methods for Atlantic salmon (Salmo salar), gilt-head seabream (Sparus auratus) and eel (Anguilla anguilla) with respect to welfare and quality. As a general term of reference, an optimal slaughter method should render fish unconscious

  15. Smart acquisition EELS

    International Nuclear Information System (INIS)

    Sader, Kasim; Schaffer, Bernhard; Vaughan, Gareth; Brydson, Rik; Brown, Andy; Bleloch, Andrew

    2010-01-01

    We have developed a novel acquisition methodology for the recording of electron energy loss spectra (EELS) using a scanning transmission electron microscope (STEM): 'Smart Acquisition'. Smart Acquisition allows the independent control of probe scanning procedures and the simultaneous acquisition of analytical signals such as EELS. The original motivation for this work arose from the need to control the electron dose experienced by beam-sensitive specimens whilst maintaining a sufficiently high signal-to-noise ratio in the EEL signal for the extraction of useful analytical information (such as energy loss near edge spectral features) from relatively undamaged areas. We have developed a flexible acquisition framework which separates beam position data input, beam positioning, and EELS acquisition. In this paper we demonstrate the effectiveness of this technique on beam-sensitive thin films of amorphous aluminium trifluoride. Smart Acquisition has been used to expose lines to the electron beam, followed by analysis of the structures created by line-integrating EELS acquisitions, and the results are compared to those derived from a standard EELS linescan. High angle annular dark-field images show clear reductions in damage for the Smart Acquisition areas compared to the conventional linescan, and the Smart Acquisition low loss EEL spectra are more representative of the undamaged material than those derived using a conventional linescan. Atomically resolved EELS of all four elements of CaNdTiO show the high resolution capabilities of Smart Acquisition.

  16. Smart acquisition EELS

    Energy Technology Data Exchange (ETDEWEB)

    Sader, Kasim, E-mail: k.sader@leeds.ac.uk [SuperSTEM, J block, Daresbury Laboratory, Warrington, Cheshire, WA4 4AD (United Kingdom); Institute for Materials Research, University of Leeds, LS2 9JT (United Kingdom); Schaffer, Bernhard [SuperSTEM, J block, Daresbury Laboratory, Warrington, Cheshire, WA4 4AD (United Kingdom); Department of Physics and Astronomy, University of Glasgow (United Kingdom); Vaughan, Gareth [Institute for Materials Research, University of Leeds, LS2 9JT (United Kingdom); Brydson, Rik [SuperSTEM, J block, Daresbury Laboratory, Warrington, Cheshire, WA4 4AD (United Kingdom); Institute for Materials Research, University of Leeds, LS2 9JT (United Kingdom); Brown, Andy [Institute for Materials Research, University of Leeds, LS2 9JT (United Kingdom); Bleloch, Andrew [SuperSTEM, J block, Daresbury Laboratory, Warrington, Cheshire, WA4 4AD (United Kingdom); Department of Engineering, University of Liverpool, Liverpool (United Kingdom)

    2010-07-15

    We have developed a novel acquisition methodology for the recording of electron energy loss spectra (EELS) using a scanning transmission electron microscope (STEM): 'Smart Acquisition'. Smart Acquisition allows the independent control of probe scanning procedures and the simultaneous acquisition of analytical signals such as EELS. The original motivation for this work arose from the need to control the electron dose experienced by beam-sensitive specimens whilst maintaining a sufficiently high signal-to-noise ratio in the EEL signal for the extraction of useful analytical information (such as energy loss near edge spectral features) from relatively undamaged areas. We have developed a flexible acquisition framework which separates beam position data input, beam positioning, and EELS acquisition. In this paper we demonstrate the effectiveness of this technique on beam-sensitive thin films of amorphous aluminium trifluoride. Smart Acquisition has been used to expose lines to the electron beam, followed by analysis of the structures created by line-integrating EELS acquisitions, and the results are compared to those derived from a standard EELS linescan. High angle annular dark-field images show clear reductions in damage for the Smart Acquisition areas compared to the conventional linescan, and the Smart Acquisition low loss EEL spectra are more representative of the undamaged material than those derived using a conventional linescan. Atomically resolved EELS of all four elements of CaNdTiO show the high resolution capabilities of Smart Acquisition.

  17. The effect of para-nonylphenol on Japanese eel (Anguilla japonica) spermatogenesis in vitro

    International Nuclear Information System (INIS)

    Miura, C.; Takahashi, N.; Michino, F.; Miura, T.

    2005-01-01

    Endocrine disrupters have been recognized to interfere with endocrine systems that regulate reproduction, for example, by mimicking or inhibiting the action of endogenous sex steroid hormones including estradiol-17β (E2). In the present study, we examined the effect of an endocrine disrupter, para-nonylphenol (p-NP) on spermatogenesis, and compared it with the action of E2, using an eel testicular organ culture system. p-NP alone stimulated early spermatogonial renewal in the same manner as E2. Neither induced further progress in spermatogenesis. In the presence of 11-ketotestosterone (11-KT), the major androgen in teleosts, p-NP did not prevent the 11-KT-induced progress in spermatogenesis. However, this treatment enlarged the Sertoli cells. Electron microscopic observation revealed that enlarged Sertoli cells contained well-developed organelles. Moreover, the proportion of germ cells appeared to have decreased as a result of Sertoli cell hypertrophy. These results clearly show that p-NP has an effect on Sertoli cells in the presence of an androgen (11-KT), potentially disturbing 11-KT-induced spermatogenesis

  18. Macroparasites and their communities of the European eel Anguilla anguilla (Linnaeus) in the Czech Republic

    Czech Academy of Sciences Publication Activity Database

    Moravec, František; Scholz, Tomáš

    2015-01-01

    Roč. 62, JUN 30 2015 (2015), 033 ISSN 1803-6465 R&D Projects: GA ČR GBP505/12/G112 Institutional support: RVO:60077344 Keywords : Central Europe * Danube River basin * Elbe River basin * Oder River basin * fish * host specificity * parasite fauna * species diversity Subject RIV: EG - Zoology Impact factor: 1.271, year: 2015

  19. Abundance of specific mRNA transcripts impacts hatching success in European eel, Anguilla anguilla L

    DEFF Research Database (Denmark)

    Rozenfeld, Christoffer; Butts, Ian A.E.; Tomkiewicz, Jonna

    2016-01-01

    -tubulin, insulin-like growth factor 2 (igf2), nucleoplasmin (npm2), prohibitin 2 (phb2), phosphatidylinositol glycan biosynthesis class F protein 5 (pigf5), and carnitine O-palmitoyltransferase liver isoform-like 1 (cpt1) are associated with embryonic developmental competence in other teleosts. Here, the relations...... and no hatching groups for any of the selected genes at 0, 2.5, and 5 HPF. However, at 30 HPF the hatch group showed significantly higher abundance of cpt1a, cpt1b, β-tubulin, phb2, and pigf5 transcripts than the no hatch group. Therefore, these results indicate that up-regulation of the transcription...

  20. Functional Analysis of Promoter Region from Eel Cytochrome P450 1A1 Gene in Transgenic Medaka.

    Science.gov (United States)

    Ogino; Itakura; Kato; Aoki; Sato

    1999-07-01

    : Transcription of the CYP1A1 genes in mammals and fish is stimulated by polyaromatic hydrocarbons. DNA sequencing analysis revealed that CYP1A1 gene in eel (Anguilla japonica) contains two kinds of putative cis-acting regulatory elements, XRE (xenobiotic-responsive element) and ERE (estrogen-responsive element). XRE is known as the enhancer that is responsible for the inducibility of the genes of CYP1A1 and some other drug-metabolizing enzymes. In the eel CYP1A1 gene, XRE motifs are distributed as follows: five times in the region from -2136 to -1125 bp, XRE(-6) to (-2); once in the proximal basal promoter region, XRE(-1); and once in the first intron, XRE(+1). The region between XRE(-2) and XRE(-1) contains three ERE motifs. To investigate the function of the cis-acting regulatory elements in the eel CYP1A1 gene, recombinant plasmids prepared with its 5' upstream sequence and the structural gene for luciferase were microinjected into fertilized eggs of medaka at the one-cell stage. Hatched fry were treated with 3-methylcholanthrene, and the transcription efficiency was assayed using competitive polymerase chain reaction analysis. Deletion of the region containing the five XREs, XRE(-6) to XRE(-2), and the point mutation of XRE(-1) reduced the inducible expressions by 75% and 56%, respectively, showing apparent dependency of the drug induction on the XREs. Constitutive expression, however, was not significantly affected by deletion or disruption of the XREs. When the region between XRE(-2) and XRE(-1) containing no XREs but three ERE motifs was internally deleted, the inducible expression and the constitutive expression were reduced by 88% and 75%, respectively. Replacement of this region with a partial fragment of eel CYP1A1 complementary DNA, with slight alteration of the distance between the five XREs and XRE(-1), reduced the inducible expression and the constitutive expression by 91% and 60%, respectively. These results strongly suggest that not only XRE but

  1. Bypass devices for descent of eels in hydropower plants; Bypasseinrichtungen zum Abstieg von Aalen an Wasserkraftanlagen

    Energy Technology Data Exchange (ETDEWEB)

    Goehl, C.

    2004-07-01

    During their downstream migration, as a consequence of passing hydroelectric turbines, eels receive various injuries. Because of declining numbers the European eel has already been declared an endangered species in several German states. In respect to the distinctive situation of the hydroelectric power station Dettelbach in the river Main, as a first step the fluidic prerequisites of eel migration as well as facilities for the downstream passage of eels were examined in a physical experiment. Following behavioral tests with eels were used to verify their acceptance of these installations. Based on the attained results this thesis discusses the basics of the construction of downstream passage facilities for eels, heeding the principle which underlie the principle of no force and limitation on the area of main activity. The gained results suggest a feasible and cost-effective concept for the downstream passage of eels. Although the transferability of instinctive reactions and a basic efficiency is assumed, further wildlife experiments have to be conducted to verify efficiency in a natural environment. (orig.)

  2. Efficiency of peptide nucleic acid-directed PCR clamping and its application in the investigation of natural diets of the Japanese eel leptocephali.

    Directory of Open Access Journals (Sweden)

    Takeshi Terahara

    Full Text Available Polymerase chain reaction (PCR-clamping using blocking primer and DNA-analogs, such as peptide nucleotide acid (PNA, may be used to selectively amplify target DNA for molecular diet analysis. We investigated PCR-clamping efficiency by studying PNA position and mismatch with complementary DNA by designing PNAs at five different positions on the nuclear rDNA internal transcribed spacer 1 of the Japanese eel Anguilla japonica in association with intra-specific nucleotide substitutions. All five PNAs were observed to efficiently inhibit amplification of a fully complementary DNA template. One mismatch between PNA and template DNA inhibited amplification of the template DNA, while two or more mismatches did not. DNA samples extracted from dorsal muscle and intestine of eight wild-caught leptochephalus larvae were subjected to this analysis, followed by cloning, nucleotide sequence analysis, and database homology search. Among 12 sequence types obtained from the intestine sample, six were identified as fungi. No sequence similarities were found in the database for the remaining six types, which were not related to one another. These results, in conjunction with our laboratory observations on larval feeding, suggest that eel leptocephali may not be dependent upon living plankton for their food source.

  3. Musculoskeletal anatomy and feeding performance of pre-feeding engyodontic larvae of the European eel (Anguilla anguilla)

    DEFF Research Database (Denmark)

    Bouilliart, M.; Tomkiewicz, Jonna; Lauesen, P.

    2015-01-01

    changes in the functionality of the feeding apparatus towards the active feeding phase, 3D data of joints, levers and muscles derived from the reconstructions were used to estimate bite and joint reaction forces (JRFs). Observing a maximum estimated bite force of about 65μN (and corresponding JRFs of 260μ...

  4. Isolation and characterization of active LINE and SINEs from the eel.

    Science.gov (United States)

    Kajikawa, Masaki; Ichiyanagi, Kenji; Tanaka, Nozomu; Okada, Norihiro

    2005-03-01

    Long interspersed elements (LINEs) and short interspersed elements (SINEs) are retrotransposons. These elements can mobilize by the "copy-and-paste" mechanism, in which their own RNA is reverse-transcribed into complementary DNA (cDNA). LINEs and SINEs not only are components of eukaryotic genomes but also drivers of genomic evolution. Thus, studies of the amplification mechanism of LINEs and SINEs are important for understanding eukaryotic genome evolution. Here we report the characterization of one LINE family (UnaL2) and two SINE families (UnaSINE1 and UnaSINE2) from the eel (Anguilla japonica) genome. UnaL2 is approximately 3.6 kilobases (kb) and encodes only one open reading frame (ORF). UnaL2 belongs to the stringent type--thought to be a major group of LINEs--and can mobilize in HeLa cells. We also show that UnaL2 and the two UnaSINEs have similar 3' tails, and that both UnaSINE1 and UnaSINE2 can be mobilized by UnaL2 in HeLa cells. These elements are thus useful for delineating the amplification mechanism of stringent type LINEs as well as that of SINEs.

  5. Studies on food organisms of pelagic fishes as revealed by the 1979 North Atlantic Eel Expedition

    Science.gov (United States)

    Appelbaum, S.

    1982-09-01

    The extent to which pelagic fishes occurring in the Sargasso Sea and adjacent parts of the Atlantic prey on leptocephali (Anguilliformes) was investigated. Most of the fishes examined (c. 95%) were collected using a commercial pelagical trawl. The stomach contents of about 1000 fishes (25 species of 10 families), mostly belonging to the suborders Myctophoidei, Stomiatoidei and the order Anguilliformes, were examined. The remains of invertebrates, mainly crustaceans, molluscs, tunicates, chaetognaths, and siphonophores were found in 28.8 % of the stomachs. Fishes, mostly myctophids or fish remains, were observed in 11.2 % of the stomachs; 18.7 % contained unidentified items and 40.6 % were empty. Leptocephali ( Ariosoma spp. and Gnathophis sp.) were found in the alimentary tract of 0.5 % of the fishes examined, exclusively represented by the myctophid, Ceratoscopelus warmingii. This report indicates that the Sargasso Sea population of Anguilla leptocephali, economically the most important eel, is not seriously affected by predation of oceanic fish species considered in this study.

  6. Plecospondylic spinal column in the eel Anguilla anguilla

    NARCIS (Netherlands)

    Stolk, A.

    1956-01-01

    Several cases of deformities in the spinal column were described in fishes, viz. lordosis in the bitterling Rhodeus amarus) by ROTH (1922), in the minnow (Phoxinus phoxinus) by ROTH (1922), in the pike (Esox lucius) by ROTH (1922) and PLEHN (1924); kyphosis in the toothcarps (Cyprinodontidae) by

  7. Perfluorooctane sulfonic acid and organohalogen pollutants in liver of three freshwater fish species in Flanders (Belgium): relationships with biochemical and organismal effects

    Energy Technology Data Exchange (ETDEWEB)

    Hoff, Philippe Tony [Department of Biology, Research Unit Ecophysiology, Biochemistry and Toxicology, Antwerp University, Groenenborgerlaan 171, B-2020 Antwerp (Belgium)]. E-mail: philippe.hoff@ua.ac.be; Van Campenhout, Karen [Department of Biology, Research Unit Ecophysiology, Biochemistry and Toxicology, Antwerp University, Groenenborgerlaan 171, B-2020 Antwerp (Belgium); Van de Vijver, Kristin [Department of Biology, Research Unit Ecophysiology, Biochemistry and Toxicology, Antwerp University, Groenenborgerlaan 171, B-2020 Antwerp (Belgium); Covaci, Adrian [Toxicological Centre, Antwerp University, Universiteitsplein 1, B-2610 Wilrijk (Belgium); Bervoets, Lieven [Department of Biology, Research Unit Ecophysiology, Biochemistry and Toxicology, Antwerp University, Groenenborgerlaan 171, B-2020 Antwerp (Belgium); Moens, Lotte [Department of Biology, Research Unit Ecophysiology, Biochemistry and Toxicology, Antwerp University, Groenenborgerlaan 171, B-2020 Antwerp (Belgium); Huyskens, Geert [Department of Biology, Research Unit Ecophysiology, Biochemistry and Toxicology, Antwerp University, Groenenborgerlaan 171, B-2020 Antwerp (Belgium); Goemans, Geert [Institute for Forestry and Game Management, Duboislaan 14, B-1560 Groenendaal (Belgium); Belpaire, Claude [Institute for Forestry and Game Management, Duboislaan 14, B-1560 Groenendaal (Belgium); Blust, Ronny [Department of Biology, Research Unit Ecophysiology, Biochemistry and Toxicology, Antwerp University, Groenenborgerlaan 171, B-2020 Antwerp (Belgium); Coen, Wim de [Department of Biology, Research Unit Ecophysiology, Biochemistry and Toxicology, Antwerp University, Groenenborgerlaan 171, B-2020 Antwerp (Belgium)

    2005-09-15

    A perfluorooctane sulfonic acid (PFOS) assessment was conducted on gibel carp (Carassius auratus gibelio), carp (Cyprinus carpio), and eel (Anguilla anguilla) in Flanders (Belgium). The liver PFOS concentrations in fish from the Ieperlee canal (Boezinge, 250-9031 ng/g wet weight, respectively) and the Blokkersdijk pond (Antwerp, 633-1822 ng/g wet weight) were higher than at the Zuun basin (Sint-Pieters-Leeuw, 11.2-162 ng/g wet weight) and among the highest in feral fish worldwide. Eel from the Oude Maas pond (Dilsen-Stokkem) and Watersportbaan basin (Ghent) had PFOS concentrations ranging between 212 and 857 ng/g wet weight. The hepatic PFOS concentration was significantly and positively related with the serum alanine aminotransferase activity, and negatively with the serum protein content in eel and carp. The hepatic PFOS concentration in carp correlated significantly and negatively with the serum electrolyte concentrations whereas a significant positive relation was found with the hematocrit in eel. Although 13 organochlorine pesticides, 22 polychlorinated biphenyl (PCB) congeners and 7 polybrominated diphenyl ethers (PBDEs) were also measured in the liver tissue, only PCB 28, PCB 74, {gamma}-hexachlorocyclohexane ({gamma}-HCH) and hexachlorobenzene (HCB) were suggested to contribute to the observed serological alterations in eel. - Hepatic perfluorooctane sulfonic acid contamination in Flanders (Belgium) might affect serological endpoints in feral carp and eel.

  8. Report on the eel stock and eel fishery in the Netherlands in 2011

    NARCIS (Netherlands)

    Graaf, de M.; Bierman, S.M.

    2012-01-01

    Eel fisheries in the Netherlands occur in coastal waters, estuaries, larger and smaller lakes, rivers, polders, etc. Management of eel stock and fisheries has been an integral part of the long tradition in manipulating water courses (polder construction, river straightening, ditches and canals,

  9. Introduction to the study of cadmium fixation in Anguilla anguilla (L.)

    International Nuclear Information System (INIS)

    Pally, Monique; Foulquier, Luc

    1975-05-01

    Eels weighing an average of about 30 grams were kept without food in fresh-water aquaria containing approximately 10, 30 and 50 p.p.b. of cadmium in the form of cadmium chloride. In each case the evolution of the cadmium content in the water was monitored as a function of elapsed time. After dissection, the cadmium concentration in the principal organs of the eels (in p.p.b.) was determined and compared with their live weight. To do so, various methods were used for destruction of biological material and cadmium analysis i.e.: incineration in a 600 deg C furnace, incineration at low temperature in a jet of active oxygen, nitro-sulfuric mineralization followed by atomic absorption spectrophotometric analysis, and nitro-sulfuro-perchloric mineralization followed by inverse anodic redissolution. The results of these analyses raise a number of methodological questions, in that they differ according to the technique being used. The first content data essentially concern the cadmium content of eels (after nitro-sulfuric mineralization) kept in water containing 10 p.p.b. of cadmium: after 44 days the concentrations in the various organs continue to rise. The highest concentration is found in the spleen - heart - air bladder system (15200 ppb compared with 2680 ppb in the control group), followed - in an order which varies over time - by the kidneys, branchiae and liver; the digestive tract seems to concentrate cadmium more slowly [fr

  10. Implications of individual growth status on the future sex of the European eel

    DEFF Research Database (Denmark)

    Holmgren, K.; Mosegaard, Henrik

    1996-01-01

    than females. Males also had lower length at weight than females, even in the smallest weight groups. Early growth status may influence the future sex of undifferentiated eels, but other approaches are needed for distinction between cause and effect. (C) 1996 The Fisheries Society of the British Isles....

  11. [Accumulation of cyclic adenosine monophosphate in the ovary of the eel (Anguilla anguilla L.) in vitro under the effect of carp gonadotropin or ovine lutropin: kinetics and thermodependence].

    Science.gov (United States)

    Salmon, C; Marchelidon, J; Fontaine-Bertrand, E; Fontaine, Y A

    1986-01-01

    Cyclic AMP (cAMP) in pieces of eel ovary was greatly increased in vitro by the gonadotropin (cGTH) of carp, another teleost fish; after one hour at 20 degrees C, maximal stimulation = 31.7 and E.D. 50 = 0.08 micrograms/ml. Ovine lutropin (oLH) had less effect (maximal stimulation: 2.35; E.D. 50: 1.42 micrograms/ml); its action suggested that it involved a subfraction (oLH/cGTH RAc) of the receptor-adenylate cyclase (RAc) systems which mediate the action of cGTH. Another difference was the percentage of total cAMP accumulated under hormonal stimulation and released into the incubation medium; this percentage was much higher with oLH than with cGTH (47 vs 8% after one hour at 20 degrees C). This result might be explained by a localization of oLH/cGTH RAc in cells (theca ?) situated on the outside of the follicles and/or by a relative lack of cAMP binding proteins in the case of cAMP produced by oLH/cGTH RAc. Kinetic and thermodependence studies also disclosed hormone-dependent differences; at 5 degrees C, cAMP concentration was maximal after 40 min with oLH, whereas it was still increasing after 3 h with cGTH. Differences in the properties of phosphodiesterases and/or in the clearance rate of hormone-receptor (HR) complexes could explain these results. The set of RAc systems in eel ovary recognizing fish gonadotropin would then be heterogeneous; some of them would be endowed with original properties concerning receptor specificity and cAMP diffusion as well as associated phosphodiesterase activity and/or HR metabolism. We suggest that at a stage of evolution when a single sensu stricto GTH is present (instead of two in tetrapods), "isoreceptors", differing in specificity and in their fate after hormone binding, could be an important element in the fine regulation of gonadal functions.

  12. Do trout swim better than eels? Challenges for estimating performance based on the wake of self-propelled bodies

    Science.gov (United States)

    Tytell, Eric D.

    Engineers and biologists have long desired to compare propulsive performance for fishes and underwater vehicles of different sizes, shapes, and modes of propulsion. Ideally, such a comparison would be made on the basis of either propulsive efficiency, total power output or both. However, estimating the efficiency and power output of self-propelled bodies, and particularly fishes, is methodologically challenging because it requires an estimate of thrust. For such systems traveling at a constant velocity, thrust and drag are equal, and can rarely be separated on the basis of flow measured in the wake. This problem is demonstrated using flow fields from swimming American eels, Anguilla rostrata, measured using particle image velocimetry (PIV) and high-speed video. Eels balance thrust and drag quite evenly, resulting in virtually no wake momentum in the swimming (axial) direction. On average, their wakes resemble those of self-propelled jet propulsors, which have been studied extensively. Theoretical studies of such wakes may provide methods for the estimation of thrust separately from drag. These flow fields are compared with those measured in the wakes of rainbow trout, Oncorhynchus mykiss, and bluegill sunfish, Lepomis macrochirus. In contrast to eels, these fishes produce wakes with axial momentum. Although the net momentum flux must be zero on average, it is neither spatially nor temporally homogeneous; the heterogeneity may provide an alternative route for estimating thrust. This review shows examples of wakes and velocity profiles from the three fishes, indicating challenges in estimating efficiency and power output and suggesting several routes for further experiments. Because these estimates will be complicated, a much simpler method for comparing performance is outlined, using as a point of comparison the power lost producing the wake. This wake power, a component of the efficiency and total power, can be estimated in a straightforward way from the flow

  13. How fast do eels grow

    International Nuclear Information System (INIS)

    Hansen, H.J.M.

    1988-01-01

    Not so very much about the growth pattern of the eel is known yet. Eels move about nearly all the time. They are thus very difficult to follow and we do not, for examble, yet know how long it actually takes for them to grow to maturity in the wild. So far, a macroscopic analysis of the number of bright and dark areas (growth rings) in the 'earstones' has been used to determine eel age, but this method was recently challenged. Use of radioisotopes has been suggested previously for this purpose. For this present study the rare earth elements, europium-152 and europium-155 are used. When incubated in artificial sea water, a satisfactory final radioactive label was achieved. Two experiments were planned in collaboration with the Swedish Environmental Protection Agency. 2000 Elvers were set out in 1982, in the cooling water outlet of the Oskarshamn nuclear power plant, each marked with europium-155. In 1984 another 10 000 elvers labelled with europium-152 were set out under similar conditions. The idea was mainly to see how fast the eels would grow, and to compare their known age with that determined by examining the earstones. Results showed that there was no clear-cut correlation between actual eel age and the biological age determination used so far. During four years, only 10 of the original 1300 eels were recaptured. It is thus hard to say anything definite from our results on the viability of setting out elvers in the environment

  14. An introduction to the experimental study of zinc 65 retention by Anguilla anguilla (L)

    International Nuclear Information System (INIS)

    Foulquier, L.; Delaunay, P.; Lambrechts, A.

    1975-01-01

    Eels from the Rhone River delta, with a live weight of 15 to 20g representing a total biomass of about 200g, were placed in fresh-water aquaria containing zinc 65 in nitrate or chloride form. The amount of 65 Zn retained by the fish after 20 days was approximately 2% of the activity introduced. 65 Zn fixation was a gradual phenomenon for which equilibrium conditions appeared difficult to achieve. After 21 days the concentration factor for the entire animal was about 14. The branchiae, liver, kidneys and digestive tract showed the greatest specific activity levels. The muscle structure could represent up to 40% of the zinc 65 retained by the eel. Zinc 65 was excreted slowly [fr

  15. Accumulation of persistent organic pollutants in consumers of eel from polluted rivers compared to marketable eel.

    Science.gov (United States)

    van den Dungen, Myrthe W; Kok, Dieuwertje E; Polder, Anuschka; Hoogenboom, Ron L A P; van Leeuwen, Stefan P J; Steegenga, Wilma T; Kampman, Ellen; Murk, Albertinka J

    2016-12-01

    Globally, many river sediments are seriously contaminated with persistent organic pollutants (POPs) known to accumulate in aquatic food. In the Netherlands, toxicological risks of human exposure to dioxins and dioxin-like compounds led to a ban on eel fishing in the Rhine-Meuse delta. The aim of this study is to investigate differences in serum POP levels in consumers of eel from high-polluted areas and consumers of eel from low-polluted areas or aquaculture. In total 80 Dutch men were included, aged 40-70 years, with a habitual eel consumption of at least one portion (150 g) per month. Total levels of dioxins and dioxin-like compounds were measured in serum of all participants with the DR CALUX bioassay, validated with GC-MS. For a subgroup of 38 participants extensive POP measurements were performed. We revealed that consumption of eel from polluted rivers resulted in 2.5 and up to 10 times increased levels of dioxins and polychlorinated biphenyls (PCBs) respectively compared to controls. The highest PCB levels were detected for PCB 153, with a median level of 896 ng/g lipid and a maximum level of 5000 ng/g lipid in the high-exposed group. Furthermore, hydroxylated PCB metabolites (OH-PCBs: sum of 4-OH-CB107, 4-OH-CB146, 4'-OH-CB172, and 4-OH-CB187) were 8 times higher in men who consumed eel from polluted areas, and detected at levels (median 4.5 ng/g ww) reported to cause adverse health effects. Also, the majority of the perfluoroalkyl substances (PFASs) were significantly higher in consumers of eel from pullulated areas. In conclusion, this study is the first to reveal that (past) consumption of eel from polluted rivers resulted in high body burdens of dioxins, PCBs, OH-PCBs and PFASs. We confirmed the predictions made in a former risk assessment, and the high levels of dioxins and dioxin-like compounds as well as the OH-PCBs are of health concern. Copyright © 2016 Elsevier Ltd. All rights reserved.

  16. Temperature induced variation in gene expression of thyroid hormone receptors and deiodinases of European eel (Anguilla anguilla) larvae

    DEFF Research Database (Denmark)

    Politis, Sebastian Nikitas; Servili, A.; Mazurais, D.

    2018-01-01

    Thyroid hormones (THs) are key regulators of growth, development, and metabolism in vertebrates and influence early life development of fish. TH is produced in the thyroid gland (or thyroid follicles) mainly as T4 (thyroxine), which is metabolized to T3 (3,5,3'-triiodothyronine) and T2 (3...

  17. Effects of PCBs on the energy cost of migration and blood parameters of European silver eel (Anguilla anguilla)

    NARCIS (Netherlands)

    Ginneken, van V.; Palstra, A.P.; Nieveen, M.; Berg, van den J.H.J.; Flik, G.; Spanings, F.A.; Niemantsverdriet, P.; Thillart, van den G.; Murk, A.J.

    2009-01-01

    Organochlorine compounds were widely used after the Second World War because they were cheap to produce and useful for many purposes, such as in agriculture for insecticides, in public health to control disease insect vectors and in industry (Pelletier et al. 2002). It is estimated that 16¿30% of

  18. Direct absorption and transfer of cesium 137 in a simplified fresh water supply line

    International Nuclear Information System (INIS)

    Foulquier, L.; Grauby, A.; Lambrechts, A.

    1977-01-01

    Experimentally the transfer of Cesium 137 through the supply line: Daphnia Magna Straus→Lebistes Reticulatus Peters→Anguilla Anguilla L. starting from water at 50μCi/l is studied. In the direct transfer water→organisms, the three links used have a concentration factor comprised between 2 and 4. The organisms retain a maximum of 0,3% of the water's radioactivity. The muscular mass of the eel represents 60% of the animal's total activity. The biological period is close to 400 days indicating that the fixed Cesium is strongly retained. Through the absorption of a contaminated meal, the Lebists, after two days, retain 67% of the activities of the Daphnies and the Eels, after seven days, 39% of the activity of the Guppys. At the end of the experiment, the Eels contaminated by food 3.500. It takes 63 meals for the level of contamination due to food to equal that due to water. The concentration factors measured in situ are always distinctly higher than those obtained in the laboratory. The experiment proves the possibilities of concentration through the food supply line [fr

  19. Effects of oestradiol-enriched diet and of feeding with porcine testicular tissue on macroscopic gonadal sex in European eels

    DEFF Research Database (Denmark)

    Andersen, D.; Boetius, I.; Larsen, L.O.

    1996-01-01

    days there were 44% with female-gonads, 40% with male+female-gonads and 16% with male-gonads. Oestradiol thus had a feminizing effect, not only on morphologically undifferentiated gonads but also on morphologically differentiated male-gonads. The presence of sex steroid hormones or their precursors...... and 78% of oestradiol-treated eels developed female-gonads. Minced porcine testicular tissue fed to 2-g eels for up to 371 days had effects similar to oestradiol-enriched food (68% with female-gonads), whereas feeding for only 91 days had no effect during the next 8 months. Oestradiol-enriched food...... in porcine testicular tissue may also exert a feminizing influence. In all experiments the hormone-fed groups showed a tendency (not significant) towards increased growth rate. In small eels early rapid growth and differentiation of female-gonads were clearly correlated, both in hormone treated...

  20. Aspergillus flavus infection on preserved Eel (Thysoidea macrurus)

    Digital Repository Service at National Institute of Oceanography (India)

    Gupta, R.; Samuel, C.T.

    The fungus Aspergillus flavus was observed growing on a 2.1 m long specimen of eel (Thyrsoidea macrurus). Half of the eel was submerged in 5% formalin in a loosely covered specimen jar. The fungus grew on the eel skin as yellowish-green, heavily...

  1. EEL bio makers for water pollution monitoring. Vigilancia de la contaminacion acuatica por medio de biomarcadores en la anguila

    Energy Technology Data Exchange (ETDEWEB)

    Nunez-Delgado, A.; Fenet, H.; Casellas, C.; Stein, X.; Lafaurie, M.; Botoux, J.

    1994-01-01

    The characteristic of several bio markers capable of being use in water quality monitoring mainly those related to the cytochrome P450 enzymatic system-are reviewed, and their advantages and limitations are analyzed. The usefulness of the European eel as a bio indicator organism in environmental water pollution monitoring is studied. Experimental data support, the use of eel hepatic microsomal ethoxyresorufino-O-deethylase activity determination (EROD) as a bio marker of water pollution caused by organic compounds such as polycyclic aromatic hydrocarbons. (Author) 48 p.

  2. Simulating the Oceanic Migration of Silver Japanese Eels.

    Directory of Open Access Journals (Sweden)

    Yu-Lin Chang

    Full Text Available The oceanic migration of silver Japanese eels starts from their continental growth habitats in East Asia and ends at the spawning area near the West Mariana Ridge seamount chain. However, the actual migration routes remain unknown. In this study, we examined the possible oceanic migration routes and strategies of silver Japanese eels using a particle tracking method in which virtual eels (v-eels were programmed to move vertically and horizontally in an ocean circulation model (Japan Coastal Ocean Predictability Experiment 2, JCOPE2. Four horizontal swimming strategies were tested: random heading, true navigation (readjusted heading, orientation toward the spawning area (fixed heading, and swimming against the Kuroshio. We found that all strategies, except random swimming, allowed v-eels swimming at 0.65 m s-1 to reach the spawning area within eight months after their departure from the south coast of Japan (end of the spawning season. The estimated minimum swimming speed required to reach the area spawning within eight months was 0.1 m s-1 for true navigation, 0.12 m s-1 for constant compass heading, and 0.35 m s-1 for swimming against the Kuroshio. The lowest swimming speed estimated from tracked Japanese eels at sea was 0.03 m.s-1, which would not allow them to reach the spawning area within eight months, through any of the tested orientation strategies. Our numerical experiments also showed that ocean circulation significantly affected the migration of Japanese v-eels. A strong Kuroshio could advect v-eels further eastward. In addition, western Pacific ocean currents accelerated the migration of navigating v-eels. The migration duration was shortened in years with a stronger southward flow, contributed by a stronger recirculation south of Japan, an enhanced subtropical gyre, or a higher southward Kuroshio velocity.

  3. Simulating the Oceanic Migration of Silver Japanese Eels.

    Science.gov (United States)

    Chang, Yu-Lin; Miyazawa, Yasumasa; Béguer-Pon, Mélanie

    2016-01-01

    The oceanic migration of silver Japanese eels starts from their continental growth habitats in East Asia and ends at the spawning area near the West Mariana Ridge seamount chain. However, the actual migration routes remain unknown. In this study, we examined the possible oceanic migration routes and strategies of silver Japanese eels using a particle tracking method in which virtual eels (v-eels) were programmed to move vertically and horizontally in an ocean circulation model (Japan Coastal Ocean Predictability Experiment 2, JCOPE2). Four horizontal swimming strategies were tested: random heading, true navigation (readjusted heading), orientation toward the spawning area (fixed heading), and swimming against the Kuroshio. We found that all strategies, except random swimming, allowed v-eels swimming at 0.65 m s-1 to reach the spawning area within eight months after their departure from the south coast of Japan (end of the spawning season). The estimated minimum swimming speed required to reach the area spawning within eight months was 0.1 m s-1 for true navigation, 0.12 m s-1 for constant compass heading, and 0.35 m s-1 for swimming against the Kuroshio. The lowest swimming speed estimated from tracked Japanese eels at sea was 0.03 m.s-1, which would not allow them to reach the spawning area within eight months, through any of the tested orientation strategies. Our numerical experiments also showed that ocean circulation significantly affected the migration of Japanese v-eels. A strong Kuroshio could advect v-eels further eastward. In addition, western Pacific ocean currents accelerated the migration of navigating v-eels. The migration duration was shortened in years with a stronger southward flow, contributed by a stronger recirculation south of Japan, an enhanced subtropical gyre, or a higher southward Kuroshio velocity.

  4. Long-term changes of fisheries landings in enclosed gulf lagoons (Amvrakikos gulf, W Greece): Influences of fishing and other human impacts

    Science.gov (United States)

    Katselis, George N.; Moutopoulos, Dimitrios K.; Dimitriou, Evagelos N.; Koutsikopoulos, Constantin

    2013-10-01

    The present study analyses long-term annual fishery landings time series (1980-2007) for species derived from six lagoons (covering about 70 km2) around an important European wetland, the fjord-like Amvrakikos gulf. Landing trends for most abundant species revealed that typical lagoon fish species-groups, such as Mugilidae (Mugil cephalus, Chelon labrosus, Liza saliens, Liza aurata and Liza ramada), eels (Anguilla anguilla) and Gobies (mainly Zosteriosessor ophiocephalus) had largely decreased, while the landings of Sparus aurata increased during the entire study period. These trends led to a significant change in species composition during recent years that might be attributed to large-scale climatic changes as well as serious anthropogenic impacts that degraded the water quality and altered the hydrology within the gulf and lagoons, the increase of fishing exploitation in Amvrakikos gulf, the expansion of aquaculture activities within the gulf, the application of new fishing management practices in lagoons, and the increase of fish-eating sea-bird populations. The findings are needed for the implementation of an efficient and integrated management tool for the study of coastal systems.

  5. Relationships between persistent organic chemicals residues and biochemical constituents in fish from a protected area: the French National Nature Reserve of Camargue.

    Science.gov (United States)

    Roche, Hélène; Buet, Astrid; Ramade, François

    2002-11-01

    The Reserve of Biosphere of Camargue [French National Nature Reserve of Camargue (NNRC)] is a protected area frequently exposed to natural and anthropogenic environmental alterations. To evaluate potential contamination of fish with lipophilic chemicals-organochlorines (OCs) and polycyclic aromatic hydrocarbons (PAHs)-a biological monitoring survey was carried out. Metabolic reserve levels were evaluated to select appropriate biological indicators able to be significant biomarkers. In addition, the incorporation of xenobiotic molecules in the lipid compartments was investigated. The contents of glycogen, total lipids, proteins and lipidic phosphorus were analyzed in liver and skeletal muscles of three teleostean: the European eel (Anguilla anguilla); the crucian carp (Carassius auratus); and the catfish (Ictalurus melas). The atmospheric origin of the PAH detected in any season in the biomass and the OCs compounds contamination by derive from agricultural treatments are established. In contradiction with some laboratory acute intoxication studies, we observe a positive correlation between tissue concentrations of contaminants and the muscular glycogen amount, a sensitive energy reserve marker. Moreover, it seems likely that the incorporation of these xenobiotics is located preferentially in the membrane structures.

  6. Fipronil and two of its transformation products in water and European eel from the river Elbe.

    Science.gov (United States)

    Michel, N; Freese, M; Brinkmann, M; Pohlmann, J-D; Hollert, H; Kammann, U; Haarich, M; Theobald, N; Gerwinski, W; Rotard, W; Hanel, R

    2016-10-15

    Fipronil is an insecticide which, based on its mode of action, is intended to be predominantly toxic towards insects. Fipronil bioaccumulates and some of its transformation products were reported to be similar or even more stable in the environment and to show an enhanced toxicity against non-target organisms compared to the parent compound. The current study investigated the occurrence of Fipronil and two of its transformation products, Fipronil-desulfinyl and Fipronil-sulfone, in water as well as muscle and liver samples of eels from the river Elbe (Germany). In water samples total concentrations of FIP, FIP-d and FIP-s ranged between 0.5-1.6ngL(-1) with FIP being the main component in all water samples followed by FIP-s and FIP-d. In contrast, FIP-s was the main component in muscle and liver tissues of eels with concentrations of 4.05±3.73ngg(-1) ww and 19.91±9.96ngg(-1) ww, respectively. Using a physiologically based toxicokinetic (PBTK) model for moderately hydrophobic organic chemicals, the different distributions of FIP, FIP-d and FIP-s in water and related tissue samples could be attributed to metabolic processes of eels. The measured concentrations in water of all analytes and their fractional distribution did not reflect the assumed seasonal application of FIP and it seems that the water was constantly contaminated with FIP, FIP-d and FIP-s. Copyright © 2016 Elsevier B.V. All rights reserved.

  7. Distribution and production of plankton communities in the subtropical convergence zone of the Sargasso Sea. II. Protozooplankton and copepods

    DEFF Research Database (Denmark)

    Andersen, Nikolaj G.; Nielsen, Torkel Gissel; Jakobsen, Hans Henrik

    2011-01-01

    the potential reasons why Atlantic eels Anguilla spp. use this area for spawning, we investigated the distribution and productivity of the zooplankton community across the Subtropical Convergence Zone (STCZ) in the Sargasso Sea in March and April 2007. The vertical and horizontal distributions of protozoans...

  8. Dialogues of the deaf in Dutch eel management policy. Explaining controversy and deadlock with argumentative discourse analysis

    NARCIS (Netherlands)

    Herten, M. van; Runhaar, H.A.C.

    2013-01-01

    Scientists claim the European eel stock is in a state of crisis. Although stakeholders in the Netherlands agree, also upon the need for action, for a long time no concrete measures were decided upon. Drastic protection measures were only taken 70 years after the first warning signs and 11 years

  9. OptaDOS - a new tool for EELS calculations

    Science.gov (United States)

    Nicholls, R. J.; Morris, A. J.; Pickard, C. J.; Yates, J. R.

    2012-07-01

    Many modern (Scanning) Transmission Electron Microscopes ((S)TEMs) are equipped with an energy loss spectrometer. The Electron Energy Loss (EEL) spectra collected provide an experimental method of probing the bonding within a material. With the extra addition of monochromators, the energy resolution obtainable means that even more information is revealed within the fine structure of the spectra. Interpreting the fine structure can often be aided by simulation. Density-functional theory (DFT) is one method of simulating EEL spectra. DFT allows us to simulate DOS and EEL spectra from different structures. This comparison between simulation and experiment enables us to explore how changes in the spectrum are related to changes within the sample. CASTEP is a pseudopotential DFT code which can simulate both low-loss and core-loss EEL spectra. Recent developments have resulted in a separate analysis tool, OptaDOS. This package computes various spectral properties including DOS, projected DOS, joint DOS, core-loss and low-loss EEL spectra and optical spectra. One of the important aspects of the code is the way in which the DOS is calculated. This is done via linear extrapolation or adaptive smearing, methods which are not currently available within CASTEP (or indeed any other code) and which allow detailed analysis of spectral properties. This paper summarises these developments and what they mean for the interpretation of EEL spectra.

  10. The biological transport of radionuclides in grassland and freshwater ecosystems

    International Nuclear Information System (INIS)

    Rudge, S.A.

    1989-12-01

    This thesis examines the biological transport of radionuclides through terrestrial and aquatic ecosystems, with particular reference to radiocaesium. The semi-natural grassland habitat was located at Drigg, W. Cumbria, contaminated primarily by radioactive fallout, from several sources over the past decade. Advantage was made of the deposition of radionuclides from the Chernobyl reactor incident, which occurred during the early stages of the investigation. The study examined the distribution of radiocaesium for the major components of the grassland ecosystem, within the soil-plant-invertebrate-small mammal food chain. Data concerning temporal fluctuation of radionuclide transfer factors between food chain components are presented. The final section examines the spatial distribution of radiocaesium in sediment and the freshwater eel (Anguilla anguilla) in a small stream contaminated by radioactive effluent. The relationship between activity levels in eels and the sediments in which they rest and forage was investigated. Factors influencing uptake of radiocaesium in freshwater fish were also examined. (author)

  11. Fish measurement using Android smart phone: the example of swamp eel

    Science.gov (United States)

    Chen, Baisong; Fu, Zhuo; Ouyang, Haiying; Sun, Yingze; Ge, Changshui; Hu, Jing

    The body length and weight are critical physiological parameters for fishes, especially eel-like fishes like swamp eel(Monopterusalbus).Fast and accurate measuring of body length is significant for swamp eel culturing as well as its resource investigation and protection. This paper presents an Android smart phone-based photogrammetry technology for measuring and estimating the length and weight of swamp eel. This method utilizes the feature that the ratio of lengths of two objects within an image is equal to that of in reality to measure the length of swamp eels. And then, it estimates the weight via a pre-built length-weight regression model. Analysis and experimental results have indicated that this method is a fast and accurate method for length and weight measurements of swamp eel. The cross-validation results shows that the RMSE (root-mean-square error) of total length measurement of swamp eel is0.4 cm, and the RMSE of weight estimation is 11 grams.

  12. Eel-Ernal võidutses sõjakool / Kristo Sinivee

    Index Scriptorium Estoniae

    Sinivee, Kristo

    2011-01-01

    Eel-Erna võistlus toimus 6.-7. mail Pärnumaal, sellel osales 21 võistkonda Kaitseliidust, kaitseväest, Kaitseväe Ühendatud Õppeasutustest, Politsei- ja Piirivalveametist ja vanglate relvastatud üksusest. Eel-Erna tulemused

  13. EELS signal enhancement by means of beam precession in the TEM

    International Nuclear Information System (INIS)

    Estradé, Sonia; Portillo, Joaquim; Yedra, Lluís; Rebled, José Manuel; Peiró, Francesca

    2012-01-01

    EELS is nowadays a most relevant characterization tool as it provides chemical and electronic information with an extraordinary spatial resolution. When a crystal is viewed in zone axis in the TEM, there is channelling of the electrons along the atom columns, which strongly reduce the EELS signal, so that it is generally advised to work slightly off the zone axis to collect EELS data, which may not always be possible or advantageous. In the present work, we demonstrate the use of precession to compensate for the reduction of EELS signal when in the zone axis. -- Highlights: ► Channelling compromises EELS signal in zone axis. ► Precession can be used to get rid of channelling effects. ► Use of precession to enhance EELS signal in the zone axis is demonstrated.

  14. TEM-EELS: A personal perspective

    International Nuclear Information System (INIS)

    Egerton, R.F.

    2012-01-01

    The development of electron energy-loss spectroscopy in a transmission electron microscope (TEM-EELS) is illustrated through personal anecdote, highlighting some of the basic principles, instrumentation and personalities involved. The current state of the art is reviewed, together with some challenges for the future. -- Highlights: ► The history of EELS instrumentation is reviewed in a lighthearted manner. ► The current state of the art is summarized, together with some future possibilities. ► A couple of related mathematical puzzles are offered as a challenge to the reader.

  15. Historical freshwater fish ecology: a long-term view of distribution changes and biological invasions

    Directory of Open Access Journals (Sweden)

    Miguel Clavero

    2015-12-01

    Full Text Available Past processes and events may have an important influence on contemporaneous ecological patterns, including current human impacts on landscapes and organisms. In spite of that, most of the ecological knowledge has been built upon short-term studies, which very rarely exceed one decade. Ecology and Conservation Biology have an important lack of historical approaches, a deficiency that may become a hindrance for the management of natural systems. In this talk I will present examples of how historical information on the distribution of freshwater fish and other aquatic organisms can be used to address ecological questions. Most analyses are based on two important Spanish historical written sources: the Relaciones de Felipe II (16th century and the Madoz Dictionary (19th century. The examples considered include the European eel (Anguilla anguilla, the brown trout (Salmo trutta, the common carp (Cyprinus carpio and the white clawed crayfish (Austropotamobius italicus, among other species, as well as questions related to biological invasions, habitat loss and the impacts of global warming. The outputs of ecological research based on historical data often become useful tools for present-day biodiversity conservation planning and actions.

  16. A review of the possible impacts of long-term oceanic and climate changes and fishing mortality on recruitment of anguillid eels of the Northern Hemisphere.

    Science.gov (United States)

    Knights, B

    2003-07-01

    Possible causes of declines in recruitment of European, American and Japanese eels to continental waters are reviewed. Negative correlations between the Den Oever glass eel recruitment index (DOI) and the North Atlantic Oscillation Index since 1938 are discussed, together with older anecdotal evidence. Correlations are established between the DOI and sea surface temperature anomalies at 100-250 m between 1952 and 1995 in the Sargasso Sea/Sub-Tropical Gyre (STG) spawning area. It is hypothesised that, associated with global warming trends, STG warming inhibits spring thermocline mixing and nutrient circulation, with negative impacts on productivity and hence food for leptocephalus larvae. Concurrent gyre spin-up also affects major currents and slowing of oceanic migration has probably enhanced starvation and predation losses. Local factors, such as unfavourable wind-driven currents, can also affect recruitment of glass eels on continental shelves. In contrast, evidence is discussed that indicates fishing mortality and continental climate change appear to have had lesser impacts. Similar starvation-advection explanations for declines in Japanese eel recruitment are proposed. Predictions for the future are made and multidisciplinary and integrated monitoring and research are recommended for managing eel stocks and fisheries.

  17. Alien species of fish parasites in the coastal lakes and lagoons of the southern Baltic

    Directory of Open Access Journals (Sweden)

    Jolanta Morozińska-Gogol

    2009-03-01

    Full Text Available Alien species are now found all over the world. New fish parasites have been unintentionally introduced with infected alien fish imported for aquaculture or have sometimes spread with their intermediate invertebrate hosts transported in the ballast waters of ships. Four alien fish parasites have been recorded in Polish coastal lakes and lagoons, all parasitising eels. Three were introduced with the final host - the Japanese eel - introduced for aquaculture (Anguillicola crassus, Pseudodactylogyrus anguillae and Pseudodactylogyrus bini and one (Paratenuisentis ambiguus with its sole intermediate host (Gammarus tigrinus.

  18. Surface vibrational spectroscopy (EELS)

    International Nuclear Information System (INIS)

    Okuyama, Hiroshi

    2006-01-01

    Adsorbed states of hydrogen on metal surfaces have been studied by means of electron energy loss spectroscopy (EELS). In this article, typical spectra and analysis as well as recent development are introduced. (author)

  19. Characterization of the binding specificity of Anguilla anguilla agglutinin (AAA) in comparison to Ulex europaeus agglutinin I (UEA-I).

    Science.gov (United States)

    Baldus, S E; Thiele, J; Park, Y O; Hanisch, F G; Bara, J; Fischer, R

    1996-08-01

    Using immunochemical and immunohistochemical methods, the binding site of Anguilla anguilla agglutinin (AAA) was characterized and compared with the related fucose-specific lectin from Ulex europaeus (UEA-I). In solid-phase enzyme-linked immunoassays, the two lectins recognized Fuc alpha 1-2Gal beta-HSA. AAA additionally cross-reacted with neoglycolipids bearing lacto-N-fucopentaose (LNFP) I [H type 1] and II [Le(a)] and lactodifucotetraose (LDFT) as glycan moieties. UEA-I, on the other hand, bound to a LDFT-derived neoglycolipid but not to the other neoglycolipids tested. Binding of AAA to gastric mucin was competitively neutralized by Le(a)-specific monoclonal antibodies. UEA-I binding, on the other hand, was reduced after co-incubation with H type 2- and Le(y)-specific monoclonal antibodies. According to our results, AAA reacts with fucosylated type 1 chain antigens, whereas UEA-I binds only to the alpha 1-2-fucosylated LDFT-derived neoglycolipid. In immunohistochemical studies, the reactivity of AAA and UEA-I in normal pyloric mucosa from individuals with known Lewis and secretor status was analysed. AAA showed a broad reaction in the superficial pyloric mucosa from secretors and non-secretors, but AAA reactivity was more pronounced in Le(a+b-) individuals. On the other hand, UEA-I stained the superficial pyloric mucosa only from secretor individuals. A staining of deep mucous glands by the lectins was found in all specimens. Both reacted with most human carcinomas of different origin. Slight differences in their binding pattern were observed and may be explained by the different fine-specificities of the lectins.

  20. Assessing sediment hazard through a weight of evidence approach with bioindicator organisms: a practical model to elaborate data from sediment chemistry, bioavailability, biomarkers and ecotoxicological bioassays.

    Science.gov (United States)

    Piva, Francesco; Ciaprini, Francesco; Onorati, Fulvio; Benedetti, Maura; Fattorini, Daniele; Ausili, Antonella; Regoli, Francesco

    2011-04-01

    Quality assessments are crucial to all activities related to removal and management of sediments. Following a multidisciplinary, weight of evidence approach, a new model is presented here for comprehensive assessment of hazards associated to polluted sediments. The lines of evidence considered were sediment chemistry, assessment of bioavailability, sub-lethal effects on biomarkers, and ecotoxicological bioassays. A conceptual and software-assisted model was developed with logical flow-charts elaborating results from each line of evidence on the basis of several chemical and biological parameters, normative guidelines or scientific evidence; the data are thus summarized into four specific synthetic indices, before their integration into an overall sediment hazard evaluation. This model was validated using European eels (Anguilla anguilla) as the bioindicator species, exposed under laboratory conditions to sediments from an industrial site, and caged under field conditions in two harbour areas. The concentrations of aliphatic hydrocarbons, polycyclic aromatic hydrocarbons and trace metals were much higher in the industrial compared to harbour sediments, and accordingly the bioaccumulation in liver and gills of exposed eels showed marked differences between conditions seen. Among biomarkers, significant variations were observed for cytochrome P450-related responses, oxidative stress biomarkers, lysosomal stability and genotoxic effects; the overall elaboration of these data, as those of standard ecotoxicological bioassays with bacteria, algae and copepods, confirmed a higher level of biological hazard for industrial sediments. Based on comparisons with expert judgment, the model presented efficiently discriminates between the various conditions, both as individual modules and as an integrated final evaluation, and it appears to be a powerful tool to support more complex processes of environmental risk assessment. Copyright © 2010 Elsevier Ltd. All rights reserved.

  1. Evolution of the locomotory system in eels (Teleostei: Elopomorpha).

    Science.gov (United States)

    Pfaff, Cathrin; Zorzin, Roberto; Kriwet, Jürgen

    2016-08-11

    Living anguilliform eels represent a distinct clade of elongated teleostean fishes inhabiting a wide range of habitats. Locomotion of these fishes is highly influenced by the elongated body shape, the anatomy of the vertebral column, and the corresponding soft tissues represented by the musculotendinous system. Up to now, the evolution of axial elongation in eels has been inferred from living taxa only, whereas the reconstruction of evolutionary patterns and functional ecology in extinct eels still is scarce. Rare but excellently preserved fossil eels from the Late Cretaceous and Cenozoic were investigated here to gain a better understanding of locomotory system evolution in anguilliforms and, consequently, their habitat occupations in deep time. The number of vertebrae in correlation with the body length separates extinct and extant anguilliforms. Even if the phylogenetic signal cannot entirely be excluded, the analyses performed here reveal a continuous shortening of the vertebral column with a simultaneous increase in vertebral numbers in conjunction with short lateral tendons throughout the order. These anatomical changes contradict previous hypotheses based on extant eels solely. The body curvatures of extant anguilliforms are highly flexible and can be clearly distinguished from extinct species. Anatomical changes of the vertebral column and musculotendinous system through time and between extinct and extant anguilliforms correlate with changes of the body plan and swimming performance and reveal significant shifts in habitat adaptation and thus behaviour. Evolutionary changes in the skeletal system of eels established here also imply that environmental shifts were triggered by abiotic rather than biotic factors (e.g., K/P boundary mass extinction event).

  2. Effect of Using the Lemongrass (Cimbopogon Citratus) to Smoked Eel (Monopterus Albus) Processing Quality

    OpenAIRE

    Satria, Viki Buana; Buchari, Dewita; ', Sumarto

    2015-01-01

    This study was aimed to determine the effect of using the lemongrass on organoleptic quality of smoked eel. 4 kg of fresh eel and lemongrass obtained from one of market in Pekanbaru processed into smoked eel. The treatment of this study was using the different concentration of lemongrass (0%, 10%, 20% and 30%) from fresh eel to determine the quality of smoked eel. The result showed that the lemongrass with concentration 30% was the best treatment and most favorable by consumer with appearance...

  3. Are African longfin eel imports a potential pathway for parasite invasions?

    Czech Academy of Sciences Publication Activity Database

    Weyl, O.; Taraschewski, H.; Moravec, František

    2014-01-01

    Roč. 37, č. 9 (2014), s. 843-845 ISSN 0140-7775 Institutional support: RVO:60077344 Keywords : Anguilla * Anguillicola * Anguillicoloide * invasion * pathway * trade Subject RIV: EH - Ecology, Behaviour Impact factor: 2.056, year: 2014

  4. Hepatic receptors for homologous growth hormone in the eel

    International Nuclear Information System (INIS)

    Hirano, T.

    1991-01-01

    The specific binding of 125I-labeled eel growth hormone (eGH) to liver membranes of the eel was examined. The specific binding to the 10,000g pellet was greater than that to the 600g pellet. The specific binding was linear up to about 100 mg fresh tissue, and was saturable with increasing amounts of membrane. The specific binding was pH-, temperature-, and time-dependent, with the optimum pH at 7.4, and greater specific binding was obtained at 15 and 25 degrees than at 35 degrees. Scatchard analysis of liver binding gave an association constant of 1.1 x 10(9) M-1 and a capacity of 105 fmol/mg protein. The receptor preparation was highly specific for GHs. Natural and recombinant eel GHs as well as recombinant salmon GH competed equally with 125I-eGH for the receptor sites of the 10,000g liver membrane. Ovine GH was more potent in displacing the labeled eGH than the homologous eel hormone. Tilapia GH and ovine prolactin (PRL) were needed in greater amounts (40 times) than eGH to displace the labeled eGH. Salmon and tilapia PRLs were still less potent (500 times) than eGH. There was no displacement with eel PRL. No significant change in the specific binding was seen 1 week after hypophysectomy, whereas injection of eGH into the hypophysectomized eel caused a significant reduction after 24 hr. The binding to the membrane fractions from gills, kidney, muscle, intestine, and brain was low and exclusively nonspecific, indicating the presence of specific GH receptors predominantly in the liver

  5. Regional Variations in the Risk and Severity of Ciguatera Caused by Eating Moray Eels.

    Science.gov (United States)

    Chan, Thomas Y K

    2017-06-26

    Moray eels ( Gymnothorax species) from tropical waters have long been known to be high-risk species, and the consumption of particularly the viscera or ungutted eels can result in severe ciguatera (known as Gymnothorax or moray eel poisoning), characterized by prominent neurological features. In this review, the main objective was to describe the risk and severity of ciguatera caused by eating moray eels in different parts of the world. Moray eels can accumulate very high ciguatoxin (CTX) levels in the flesh and particularly the liver. Therefore, even the smaller ones can be toxic and the consumption of an average portion (particularly liver) can result in severe or fatal ciguatera. Moray eels (particularly when ungutted) must never be served in gatherings since they can cause mass poisoning because of their large sizes and high CTX levels. Apart from regulatory measures restricting or excluding access, the public should be repeatedly warned to avoid eating moray eels.

  6. Regional Variations in the Risk and Severity of Ciguatera Caused by Eating Moray Eels

    Directory of Open Access Journals (Sweden)

    Thomas Y. K. Chan

    2017-06-01

    Full Text Available Moray eels (Gymnothorax species from tropical waters have long been known to be high-risk species, and the consumption of particularly the viscera or ungutted eels can result in severe ciguatera (known as Gymnothorax or moray eel poisoning, characterized by prominent neurological features. In this review, the main objective was to describe the risk and severity of ciguatera caused by eating moray eels in different parts of the world. Moray eels can accumulate very high ciguatoxin (CTX levels in the flesh and particularly the liver. Therefore, even the smaller ones can be toxic and the consumption of an average portion (particularly liver can result in severe or fatal ciguatera. Moray eels (particularly when ungutted must never be served in gatherings since they can cause mass poisoning because of their large sizes and high CTX levels. Apart from regulatory measures restricting or excluding access, the public should be repeatedly warned to avoid eating moray eels.

  7. Regional Variations in the Risk and Severity of Ciguatera Caused by Eating Moray Eels

    Science.gov (United States)

    Chan, Thomas Y. K.

    2017-01-01

    Moray eels (Gymnothorax species) from tropical waters have long been known to be high-risk species, and the consumption of particularly the viscera or ungutted eels can result in severe ciguatera (known as Gymnothorax or moray eel poisoning), characterized by prominent neurological features. In this review, the main objective was to describe the risk and severity of ciguatera caused by eating moray eels in different parts of the world. Moray eels can accumulate very high ciguatoxin (CTX) levels in the flesh and particularly the liver. Therefore, even the smaller ones can be toxic and the consumption of an average portion (particularly liver) can result in severe or fatal ciguatera. Moray eels (particularly when ungutted) must never be served in gatherings since they can cause mass poisoning because of their large sizes and high CTX levels. Apart from regulatory measures restricting or excluding access, the public should be repeatedly warned to avoid eating moray eels. PMID:28672845

  8. Transition radiation in EELS and cathodoluminescence

    Energy Technology Data Exchange (ETDEWEB)

    Stöger-Pollach, Michael, E-mail: stoeger@ustem.tuwien.ac.at; Kachtík, Lukáš; Miesenberger, Bernhard; Retzl, Philipp

    2017-02-15

    The excitation probability of transition radiation is measured for varying beam energies in a transmission electron microscope once using optical spectrometry of the emitted light and second using electron energy loss spectrometry. In both cases similar results are found being in good agreement with theory. The knowledge about this probability enables us to judge whether or not transition radiation has to be considered in EELS and CL data interpretation. Additionally it is shown that the emission of transition radiation happens at the sample surfaces only, when the electron passes the vacuum/sample interface and thus feeling the change of its dielectric environment. We demonstrate that in the case of aluminum the influence of transition radiation on the low loss EELS spectrum is only minor and conclude that it might be negligible for many other materials. - Highlights: • We determine the probability for the excitation of transition radiation at a large variety of beam energies in TEM. • We use a GATAN VULCAN system for optical spectrometry in the TEM. • We do angular resolved EELS experiments in a standard TEM with an angular resolution of 7.57 μrad.

  9. Adoption of radio-frequency identification to establish traceability in Taiwanese eel exported to the Japanese market.

    Science.gov (United States)

    Jeng, Shu-Ching; Wu, Chun-Lung; Yang, I-Da

    2013-01-01

    Eel culture and export to the Japanese market is an important industry in Taiwan; however, the average amount produced by each farm is small. Eels from different farms might be mixed before export, making it difficult to determine which farm is responsible for eels containing drug residues. Therefore, the Taiwanese government uses a two-stage procedure of inspection and accreditation for validating the use of good practice in aquaculture farming. Nevertheless, it is still difficult to trace any farm that has produced eels containing drug residues. Radio-frequency identification has the potential to establish traceability in eel products. Here we suggest that Japanese eel importers should insist on the use of radio-frequency identification by Taiwanese eel exporters to enable verification of the safety of eel products being exported to the Japanese market.

  10. Experiments on the use of sound as a fish deterrent

    International Nuclear Information System (INIS)

    Turnpenny, A.W.H.; Thatcher, K.P.; Wood, R.; Loeffelman, P.H.

    1993-01-01

    This report describes a series of experimental studies into the potential use of acoustic stimuli to deter fish from water intakes at thermal and hydroelectric power stations. The aim was to enlarge the range of candidate signals for testing, and to apply these in more rigorous laboratory trials and to a wider range of estuarine and marine fish species than was possible in previous initial preliminary studies. The trials were also required to investigate the degree to which fish might become habituated to the sound signals, consequently reducing their effectiveness. The species of fish which were of interest in this study were the Atlantic salmon (Salmo salar), sea trout (Salmo trutta), the shads (Alosa fallax, A. alosa), the European eel (Anguilla anguilla), bass (Dicentrarchus labrax), herring (Clupea harengus), whiting (Merlangius merlangus) and cod (Gadus morhua). All of these species are considered to be of conservation and/or commercial importance in Britain today and are potentially vulnerable to capture by nuclear, fossil-fuelled and tidal generating stations. Based on the effectiveness of the signals observed in these trials, a properly developed and sited acoustic fish deterrent system is expected to reduce fish impingement significantly at water intakes. Field trials at an estuarine power station are recommended. (author)

  11. Isolation of heat-tolerant myoglobin from Asian swamp eel Monopterus albus.

    Science.gov (United States)

    Chotichayapong, Chatrachatchaya; Wiengsamut, Kittipong; Chanthai, Saksit; Sattayasai, Nison; Tamiya, Toru; Kanzawa, Nobuyuki; Tsuchiya, Takahide

    2012-10-01

    Myoglobin from Asian swamp eel Monopterus albus was purified from fish muscle using salt fractionation followed by column chromatography and molecular filtration. The purified Mb of 0.68 mg/g wet weight of muscle was determined for its molecular mass by MALDI-TOF-MS to be 15,525.18 Da. Using isoelectric focusing technique, the purified Mb showed two derivatives with pI of 6.40 and 7.12. Six peptide fragments of this protein identified by LC-MS/MS were homologous to Mbs of sea raven Hemitripterus americanus, yellowfin tuna Thunnus albacores, blue marlin Makaira nigicans, common carp Cyprinus carpio, and goldfish Carassius auratus. According to the Mb denaturation, the swamp eel Mb had thermal stability higher than walking catfish Clarias batrachus Mb and striped catfish Pangasius hypophthalmus Mb, between 30 and 60 (°)C. For the thermal stability of Mb, the swamp eel Mb showed a biphasic behavior due to the O(2) dissociation and the heme orientation disorder, with the lowest increase in both Kd(f) and Kd(s). The thermal sensitivity of swamp eel Mb was lower than those of the other Mbs for both of fast and slow reaction stages. These results suggest that the swamp eel Mb globin structure is thermally stable, which is consistent with heat-tolerant behavior of the swamp eel particularly in drought habitat.

  12. On the origin of Anguillicoloides crassus, the invasive nematode of anguillid eels

    Czech Academy of Sciences Publication Activity Database

    Lefebvre, F.; Wielgoss, S.; Nagasawa, K.; Moravec, František

    2012-01-01

    Roč. 7, č. 4 (2012), s. 443-453 ISSN 1798-6540 Institutional support: RVO:60077344 Keywords : Anguilla * Anguillicola * fish parasite * nativeness * aquaculture * world trade Subject RIV: EA - Cell Biology Impact factor: 1.136, year: 2012

  13. Status of eel fisheries, stocks and their management in England and Wales

    Directory of Open Access Journals (Sweden)

    Aprahamian M.

    2009-05-01

    Full Text Available All continental life stages of eel are exploited in England and Wales. The main fisheries for glass eel are by estuarine dip-nets in the southwest. The main fisheries for yellow and silver eel occur in southern and eastern England, with fyke nets being the preferred instrument. Fishing effort is not directly recorded but is inferred from licence sales. Around 1100 glass eel licenses were sold annually from 1980 to 1994, increasing to around 2500 in 1998, but declined to about 800 per annum since 2001. Declared catches of glass eel have been below 1–2 t since 2001, compared to 10–70 t in the 1970s and 1980s. Licence sales for yellow and silver eel fisheries (combined varied from around 1100 to 2900 over the period 1983–2007, peaking in the mid-1980s, mid-1990s and again in 2005–2007. Declared catches peaked in the late 1980s and mid-1990s (peak 280 t, but have been low since 2001 (mean 29 t. Nett export data suggests catches may be 4 times higher. Eel landings are reported as bycatch from various marine fisheries around the UK coasts, with landings from 2001 to 2007 ranging from 0.2 to 13.7 t per annum. Assessment of stock status is based mainly on catch and catch per unit effort data as there has been little fishery independent survey of eels. There has been a general decreasing trend in both glass eel catches reported to the Agency and in nett export data. Comparing maximum catch levels in the late 1970s–early 1980s with minimum levels in the 2000s suggests that the catch has declined by around 75–95%. Trends in CPUE are similar, at least until 1998. It is concluded that current glass eel recruitment to the western coast of the UK is approximately 30% of the pre-1980 level of recruitment. Yellow and silver eel indices derived from HMRC nett exports or reported catches per licence sold, both suggest that the current estimate of stocks derived from these data are 20% those of the late 1980s and mid 1990s. The Reference Condition

  14. Silver eel migration, wind power and alternating current fields; Blankaalsvandring, vindkraft och vaexelstroemsfaelt, 2011

    Energy Technology Data Exchange (ETDEWEB)

    Lagenfelt, Ingvar; Andersson, Ingemar; Westerberg, Haakan

    2012-02-15

    How are eels affected by large offshore wind farms? The study follows the silver eels' migration and behavior at Lillgrund wind farm in Oeresund and the passage over an 130 kV AC cable between the mainland and Oeland. The aim is to see if the AC cable precludes or otherwise affects the eel's ability to reach its destination. Eels migrate up to 7500 km from the Baltic Sea to spawn in the Sargasso Sea. Every delay is of importance for the silver eels, which must be able to travel the entire distance on a single energy reserve. Fish, which make use of the earth's magnetic field for navigation or which are sensitive to electromagnetic fields, may be affected by AC cables on the seabed. The study shows that the silver eels swimming speed was reduced when there was more current in the cable and there was an average delay of 40 minutes before they passed it

  15. Prevalence of Anguillicoloides crassus and growth variation in migrant yellow-phase American eels of the upper Potomac River drainage

    Science.gov (United States)

    Zimmerman, Jennifer L.; Welsh, Stuart A.

    2012-01-01

    Prevalence of the non-native swim bladder nematode Anguillicoloides crassus has recently increased in American eels from estuaries of the North American Atlantic coast, but little is known about parasite prevalence or conditions of previous infection in upstream migrant eels within upper watersheds. This study is the first to confirm presence of A. crassus in the upper Potomac River watershed. We estimated A. crassus prevalence during 3 time periods: September to October 2006 (5/143 eels, 3.5%), August to October 2007 (0/49 eels), and June 2008 (0/50 eels). All eels were sampled from the Millville Dam eel ladder on the lower Shenandoah River, a Potomac River tributary located approximately 285 km upstream of Chesapeake Bay, USA. Of the 5 infected eels, parasite intensity was 1 for each eel, and mean intensity was also 1.0. A swim bladder degenerative index (SDI) was calculated for the 50 eels from the final sampling period, and 38% of those eels (19 of 50) showed signs of previous infection by A. crassus. We also aged 42 of the 50 eels (mean ± SE = 6.7 ± 0.29 yr, range 4 to 11 yr) from the final sampling period. Based on the range of possible SDI scores (0 to 6), severity of previously infected swim bladders was moderate (SDI = 1 or 2). Previously infected eels, however, had a lower length-at-age than that of uninfected eels. Female yellow-phase eels in upper watersheds develop into large highly fecund silver-phase adults; hence, a parasite-induced effect on growth of yellow-phase eels could ultimately reduce reproductive potential.

  16. Kaitseliit testis Eel-Ernal väljaõpet ja võimeid / Taive Kuuse

    Index Scriptorium Estoniae

    Kuuse, Taive

    2007-01-01

    Kaitseliidu sõjalis-sportliku võistluse Eel-Erna võitsid Tartu maleva kaitseliitlased ja naiskodukaitse koormusmatka Saaremaa naiskodukaitsjad. Tabel: Eel-Erna tulemused; Naiskodukaitse koormusmatka tulemused

  17. Complex life histories of fishes revealed through natural information storage devices: case studies of diadromous events as recorded by otoliths

    International Nuclear Information System (INIS)

    Elfman, M.; Limburg, K.E.; Kristiansson, P.; Svedaeng, H.; Westin, L.; Wickstroem, H.; Malmqvist, K.; Pallon, J.

    2000-01-01

    Diadromous fishes - species that move across salinity gradients as part of their life repertoire - form a major part of coastal and inland fisheries. Conventional mark-recapture techniques have long been used to track their movements, but give incomplete information at best. On the other hand, otoliths (ear-stones) of fishes can provide a complete record of major life history events, as reflected both in their microstructure and elemental composition. Strontium, which substitutes for calcium in the aragonite matrix of otoliths, is a powerful tracer of salinity histories in many migratory fishes. We measured Sr and Ca with a nuclear microprobe (PIXE) and show examples (eel, Anguilla anguilla; brown trout, Salmo trutta; American shad, Alosa sapidissima) of how the technique has solved several mysteries within fisheries biology

  18. Eel, cod and seatrout harvest in Danish recreational fishing during 2011

    DEFF Research Database (Denmark)

    Sparrevohn, Claus Reedtz; Storr-Paulsen, Marie

    , it was estimated that 80 t [Relative standard error (RSE)=6%] eel, close to 1,300 t (RSE=5 %) cod and 400 t (RSE=5 %) seatrout (including freshwater catches) was harvested in the recreational fishery. Eel is almost exclusively taken in the passive gear fykenet fishery and seatrout was mainly caught by anglers...

  19. Gnathostoma spinigerum in live Asian swamp eels (Monopterus spp.) from food markets and wild populations, United States

    Science.gov (United States)

    Cole, Rebecca A.; Choudhury, Anindo; Nico, Leo G.; Griffin, Kathryn M.

    2014-01-01

    In Southeast Asia, swamp eels (Synbranchidae: Monopterus spp.) are a common source of human gnathostomiasis, a foodborne zoonosis caused by advanced third-stage larvae (AL3) of Gnathostoma spp. nematodes. Live Asian swamp eels are imported to US ethnic food markets, and wild populations exist in several states. To determine whether these eels are infected, we examined 47 eels from markets and 67 wild-caught specimens. Nematodes were identified by morphologic features and ribosomal intergenic transcribed spacer–2 gene sequencing. Thirteen (27.7%) M. cuchia eels from markets were infected with 36 live G. spinigerum AL3: 21 (58.3%) in liver; 7 (19.4%) in muscle; 5 (13.8%) in gastrointestinal tract, and 3 (8.3%) in kidneys. Three (4.5%) wild-caught M. albus eels were infected with 5 G. turgidum AL3 in muscle, and 1 G. lamothei AL3 was found in a kidney (both North American spp.). Imported live eels are a potential source of human gnathostomiasis in the United States.

  20. PSA-NCAM expression in the teleost optic tectum is related to ecological niche and use of vision in finding food.

    Science.gov (United States)

    Labak, I; Pavić, V; Zjalić, M; Blažetić, S; Viljetić, B; Merdić, E; Heffer, M

    2017-08-01

    In this study, tangential migration and neuronal connectivity organization were analysed in the optic tectum of seven different teleosts through the expression of polysialylated neural cell adhesion molecule (PSA-NCAM) in response to ecological niche and use of vision. Reduced PSA-NCAM expression in rainbow trout Oncorhynchus mykiss optic tectum occurred in efferent layers, while in pike Esox lucius and zebrafish Danio rerio it occurred in afferent and efferent layers. Zander Sander lucioperca and European eel Anguilla anguilla had very low PSA-NCAM expression in all tectal layers except in the stratum marginale. Common carp Cyprinus carpio and wels catfish Silurus glanis had the same intensity of PSA-NCAM expression in all tectal layers. The optic tectum of all studied fishes was also a site of tangential migration with sustained PSA-NCAM and c-series ganglioside expression. Anti-c-series ganglioside immunoreactivity was observed in all tectal layers of all analysed fishes, even in layers where PSA-NCAM expression was reduced. Since the optic tectum is indispensable for visually guided prey capture, stabilization of synaptic contact and decrease of neurogenesis and tangential migration in the visual map are an expected adjustment to ecological niche. The authors hypothesize that this stabilization would probably be achieved by down-regulation of PSA-NCAM rather than c-series of ganglioside. © 2017 The Fisheries Society of the British Isles.

  1. Effects of oestradiol-enriched diet and of feeding with porcine testicular tissue on macroscopic gonadal sex in European eels

    DEFF Research Database (Denmark)

    Andersen, D.; Boetius, I.; Larsen, L.O.

    1996-01-01

    days there were 44% with female-gonads, 40% with male+female-gonads and 16% with male-gonads. Oestradiol thus had a feminizing effect, not only on morphologically undifferentiated gonads but also on morphologically differentiated male-gonads. The presence of sex steroid hormones or their precursors...... and in control eels. Otherwise no correlation was found between growth rate and gonadal sex. (C) 1996 The Fisheries Society of the British Isles...

  2. Linear chemically sensitive electron tomography using DualEELS and dictionary-based compressed sensing

    Energy Technology Data Exchange (ETDEWEB)

    AlAfeef, Ala, E-mail: a.al-afeef.1@research.gla.ac.uk [SUPA School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ (United Kingdom); School of Computing Science, University of Glasgow, Glasgow G12 8QQ (United Kingdom); Bobynko, Joanna [SUPA School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ (United Kingdom); Cockshott, W. Paul. [School of Computing Science, University of Glasgow, Glasgow G12 8QQ (United Kingdom); Craven, Alan J. [SUPA School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ (United Kingdom); Zuazo, Ian; Barges, Patrick [ArcelorMittal Maizières Research, Maizières-lès-Metz 57283 (France); MacLaren, Ian, E-mail: ian.maclaren@glasgow.ac.uk [SUPA School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ (United Kingdom)

    2016-11-15

    We have investigated the use of DualEELS in elementally sensitive tilt series tomography in the scanning transmission electron microscope. A procedure is implemented using deconvolution to remove the effects of multiple scattering, followed by normalisation by the zero loss peak intensity. This is performed to produce a signal that is linearly dependent on the projected density of the element in each pixel. This method is compared with one that does not include deconvolution (although normalisation by the zero loss peak intensity is still performed). Additionally, we compare the 3D reconstruction using a new compressed sensing algorithm, DLET, with the well-established SIRT algorithm. VC precipitates, which are extracted from a steel on a carbon replica, are used in this study. It is found that the use of this linear signal results in a very even density throughout the precipitates. However, when deconvolution is omitted, a slight density reduction is observed in the cores of the precipitates (a so-called cupping artefact). Additionally, it is clearly demonstrated that the 3D morphology is much better reproduced using the DLET algorithm, with very little elongation in the missing wedge direction. It is therefore concluded that reliable elementally sensitive tilt tomography using EELS requires the appropriate use of DualEELS together with a suitable reconstruction algorithm, such as the compressed sensing based reconstruction algorithm used here, to make the best use of the limited data volume and signal to noise inherent in core-loss EELS. - Highlights: • DualEELS is essential for chemically sensitive electron tomography using EELS. • A new compressed sensing based algorithm (DLET) gives high fidelity reconstruction. • This combination of DualEELS and DLET will give reliable results from few projections.

  3. Salinity-dependent in vitro effects of homologous natriuretic peptides on the pituitary-interrenal axis in eels.

    Science.gov (United States)

    Ventura, Albert; Kusakabe, Makoto; Takei, Yoshio

    2011-08-01

    We examined the effects of atrial, B-type, ventricular and C-type natriuretic peptides (ANP, BNP, VNP and CNP1, 3, 4) on cortisol secretion from interrenal tissue in vitro in both freshwater (FW) and seawater (SW)-acclimated eels. We first localized the interrenal and chromaffin cells in the eel head kidney using cell specific markers (cholesterol side-chain cleavage enzyme (P450ssc) and tyrosine hydroxylase (TH), respectively) and established the in vitro incubation system for eel interrenal tissue. Unexpectedly, none of the NPs given alone to the interrenal tissue of FW and SW eels stimulated cortisol secretion. However, ANP and VNP, but not BNP and three CNPs, enhanced the steroidogenic action of ACTH in SW interrenal preparations, while CNP1 and CNP4, but not ANP, BNP, VNP and CNP3, potentiated the ACTH action in FW preparations. These salinity dependent effects of NPs are consistent with the previous in vivo study in the eel where endogenous ACTH can act with the injected NPs. 8-Br-cGMP also enhanced the ACTH action in both FW and SW eel preparations, suggesting that the NP actions were mediated by the guanylyl cyclase-coupled NP receptors (GC-A and B) that were localized in the eel interrenal. Further, ANP and CNP1 stimulated ACTH secretion from isolated pituitary glands of SW and/or FW eels. In summary, the present study revealed complex mechanisms of NP action on corticosteroidogenesis through the pituitary-interrenal axis in eels, thereby providing a deeper insight into the role of the NP family in the acclimation of this euryhaline teleost to diverse salinity environments. Copyright © 2011 Elsevier Inc. All rights reserved.

  4. Expression and ontogeny of growth hormone (Gh) in the protogynous hermaphroditic ricefield eel (Monopterus albus).

    Science.gov (United States)

    Chen, Dong; Liu, Jiang; Chen, Wanping; Shi, Shuxia; Zhang, Weimin; Zhang, Lihong

    2015-12-01

    Growth hormone (GH) is a single-chain polypeptide hormone mainly secreted by somatotropes of the anterior pituitary gland and is an important regulator of somatic growth in vertebrates including teleosts. In this study, a polyclonal antiserum against ricefield eel Gh was generated and the expression of Gh at the mRNA and protein levels was analyzed. Both RT-PCR and western blot analysis showed that Gh was predominantly expressed in the pituitary glands of ricefield eels. The immunoreactive Gh signals were localized to the multicellular layers of the adenohypophysis adjacent to the neurohypophysis in ricefield eels. Ontogenetic analysis showed that immunoreactive Gh signals could be detected in the pituitary glands of ricefield eel embryos as early as 3 days post-fertilization. During the sex change from female to male, the levels of the immunoreactive Gh signals in the pituitary glands of the ricefield eels peaked at the intersexual stage. These results suggest that Gh in the pituitary glands may be associated with embryonic development before hatching, as well as with the sex change in the adult ricefield eels, possibly via the classical endocrine manner.

  5. Impacts of Interannual Ocean Circulation Variability on Japanese Eel Larval Migration in the Western North Pacific Ocean.

    Directory of Open Access Journals (Sweden)

    Yu-Lin Chang

    Full Text Available The Japanese eel larvae hatch near the West Mariana Ridge seamount chain and travel through the North Equatorial Current (NEC, the Kuroshio, and the Subtropical Countercurrent (STCC region during their shoreward migration toward East Asia. The interannual variability of circulation over the subtropical and tropical regions of the western North Pacific Ocean is affected by the Philippines-Taiwan Oscillation (PTO. This study examines the effect of the PTO on the Japanese eel larval migration routes using a three-dimensional (3D particle tracking method, including vertical and horizontal swimming behavior. The 3D circulation and hydrography used for particle tracking are from the ocean circulation reanalysis produced by the Japan Coastal Ocean Predictability Experiment 2 (JCOPE2. Our results demonstrate that bifurcation of the NEC and the strength and spatial variation of the Kuroshio affect the distribution and migration of eel larvae. During the positive phase of PTO, more virtual eels ("v-eels" can enter the Kuroshio to reach the south coast of Japan and more v-eels reach the South China Sea through the Luzon Strait; the stronger and more offshore swing of the Kuroshio in the East China Sea leads to fewer eels entering the East China Sea and the onshore movement of the Kuroshio to the south of Japan brings the eels closer to the Japanese coast. Significant differences in eel migration routes and distributions regulated by ocean circulation in different PTO phases can also affect the otolith increment. The estimated otolith increment suggests that eel age tends to be underestimated after six months of simulation due to the cooler lower layer temperature. Underestimation is more significant in the positive PTO years due to the wide distribution in higher latitudes than in the negative PTO years.

  6. Impacts of Interannual Ocean Circulation Variability on Japanese Eel Larval Migration in the Western North Pacific Ocean.

    Science.gov (United States)

    Chang, Yu-Lin; Sheng, Jinyu; Ohashi, Kyoko; Béguer-Pon, Mélanie; Miyazawa, Yasumasa

    2015-01-01

    The Japanese eel larvae hatch near the West Mariana Ridge seamount chain and travel through the North Equatorial Current (NEC), the Kuroshio, and the Subtropical Countercurrent (STCC) region during their shoreward migration toward East Asia. The interannual variability of circulation over the subtropical and tropical regions of the western North Pacific Ocean is affected by the Philippines-Taiwan Oscillation (PTO). This study examines the effect of the PTO on the Japanese eel larval migration routes using a three-dimensional (3D) particle tracking method, including vertical and horizontal swimming behavior. The 3D circulation and hydrography used for particle tracking are from the ocean circulation reanalysis produced by the Japan Coastal Ocean Predictability Experiment 2 (JCOPE2). Our results demonstrate that bifurcation of the NEC and the strength and spatial variation of the Kuroshio affect the distribution and migration of eel larvae. During the positive phase of PTO, more virtual eels ("v-eels") can enter the Kuroshio to reach the south coast of Japan and more v-eels reach the South China Sea through the Luzon Strait; the stronger and more offshore swing of the Kuroshio in the East China Sea leads to fewer eels entering the East China Sea and the onshore movement of the Kuroshio to the south of Japan brings the eels closer to the Japanese coast. Significant differences in eel migration routes and distributions regulated by ocean circulation in different PTO phases can also affect the otolith increment. The estimated otolith increment suggests that eel age tends to be underestimated after six months of simulation due to the cooler lower layer temperature. Underestimation is more significant in the positive PTO years due to the wide distribution in higher latitudes than in the negative PTO years.

  7. EEL spectroscopic tomography: Towards a new dimension in nanomaterials analysis

    Energy Technology Data Exchange (ETDEWEB)

    Yedra, Lluis, E-mail: llyedra@el.ub.es [Laboratory of Electron Nanoscopies (LENS)-MIND/IN2UB, Dept. d' Electronica, Universitat de Barcelona, c/ Marti Franques 1, E-08028 Barcelona (Spain); CCiT, Scientific and Technological Centers, Universitat de Barcelona, C/Lluis Sole i Sabaris 1, E-08028 Barcelona (Spain); Eljarrat, Alberto [Laboratory of Electron Nanoscopies (LENS)-MIND/IN2UB, Dept. d' Electronica, Universitat de Barcelona, c/ Marti Franques 1, E-08028 Barcelona (Spain); Arenal, Raul [Laboratorio de Microscopias Avanzadas (LMA), Instituto de Nanociencia de Aragon (INA), Universidad de Zaragoza, E-50018 Zaragoza (Spain); Fundacion ARAID, E-50004 Zaragoza (Spain); Pellicer, Eva; Cabo, Moises [Departament de Fisica, Facultat de Ciencies, Universitat Autonoma de Barcelona, E-08193 Bellaterra (Spain); Lopez-Ortega, Alberto; Estrader, Marta [CIN2(CIN-CSIC) and Universitat Autonoma de Barcelona, Catalan Institute of Nanotechnology, Campus de la UAB, E-08193 Bellaterra (Spain); Sort, Jordi [Institucio Catalana de Recerca i Estudis Avancats (ICREA), Departament de Fisica, Facultat de Ciencies, Universitat Autonoma de Barcelona, E-08193 Bellaterra (Spain); Baro, Maria Dolors [Departament de Fisica, Facultat de Ciencies, Universitat Autonoma de Barcelona, E-08193 Bellaterra (Spain); and others

    2012-11-15

    Electron tomography is a widely spread technique for recovering the three dimensional (3D) shape of nanostructured materials. Using a spectroscopic signal to achieve a reconstruction adds a fourth chemical dimension to the 3D structure. Up to date, energy filtering of the images in the transmission electron microscope (EFTEM) is the usual spectroscopic method even if most of the information in the spectrum is lost. Unlike EFTEM tomography, the use of electron energy-loss spectroscopy (EELS) spectrum images (SI) for tomographic reconstruction retains all chemical information, and the possibilities of this new approach still remain to be fully exploited. In this article we prove the feasibility of EEL spectroscopic tomography at low voltages (80 kV) and short acquisition times from data acquired using an aberration corrected instrument and data treatment by Multivariate Analysis (MVA), applied to Fe{sub x}Co{sub (3-x)}O{sub 4}@Co{sub 3}O{sub 4} mesoporous materials. This approach provides a new scope into materials; the recovery of full EELS signal in 3D. -- Highlights: Black-Right-Pointing-Pointer EELS-SI tomography was performed at low voltage and low acquisition times. Black-Right-Pointing-Pointer MVA has been applied for noise reduction and information extraction. Black-Right-Pointing-Pointer Tomographic reconstruction has been achieved for chemical information. Black-Right-Pointing-Pointer Elemental distribution extraction in 3D has been proved.

  8. Biologic Effects of Electric and Magnetic Fields Associated with Proposed Project Seafarer

    Science.gov (United States)

    1977-01-01

    antenna operation, and careful studies by radar tracking should be continued using available ELF sources, such as the Wisconsin ’ Pest Facility. It...human triqlyceride concentrations. 3 In another study, Beischer and Brehl used 140 8-week-old virgin female white mice; 70 mice were exposed for 24 h to...conducted by McCleave et al., possible effects of the pro- posed Seafarer system on American eels (Anguilla rostrata) and Atlantic salmon (Salmo salar

  9. A resource of genome-wide single-nucleotide polymorphisms generated by RAD tag sequencing in the critically endangered European eel

    DEFF Research Database (Denmark)

    Pujolar, J.M.; Jacobsen, M.W.; Frydenberg, J.

    2013-01-01

    Reduced representation genome sequencing such as restriction-site-associated DNA (RAD) sequencing is finding increased use to identify and genotype large numbers of single-nucleotide polymorphisms (SNPs) in model and nonmodel species. We generated a unique resource of novel SNP markers for the Eu...... 425 loci and 376 918 associated SNPs provides a valuable tool for future population genetics and genomics studies and allows for targeting specific genes and particularly interesting regions of the eel genome...

  10. Indole-positive Vibrio vulnificus isolated from disease outbreaks on a Danish eel farm

    DEFF Research Database (Denmark)

    Dalsgaard, Inger; Høi, L.; Siebeling, R.J.

    1999-01-01

    Vibrio vulnificus was isolated in 1996 from 2 disease outbreaks on a Danish eel farm which used brackish water. A characteristic clinical sign was extensive, deep muscle necrosis in the head region. V. vulnificus was isolated from kidney, mucus, spleen, gill and intestine of diseased eels. Thirty...

  11. An experimental study of the retention of zinc, zinc-cadmium mixture and zinc-65 in the presence of cadmium in Anguilla anguilla (L.)

    International Nuclear Information System (INIS)

    Pally, Monique; Foulquier, Luc

    1976-07-01

    Zinc uptake was studied in eels in fresh water, using stable zinc, a zinc-cadmium mixture, and zinc 65 in the presence of small amounts of cadmium. The zinc content in the eel began to increase after 45 days only, and reached approximately 85 ppm after 76 days in water initially containing 5ppm of zinc. At the conclusion of the experiment (76 days), the body organs could be classified in decreasing order in zinc content (in ppm): kidneys (152), skeleton (133), skin (129), muscles (89), head (80), gills (78), digestive tract (77), liver (63) spleen-heart-air bladder (32), and mucus (15). A comparison of experimental results obtained with the zinc-cadmium mixture and cadmium alone showed that zinc decreased the cadmium content of all organs except the gills. The presence of cadmium in water did not inhibit zinc uptake. As cadmium content in water increased, then zinc content in the digestive tract and the kidneys decreased and in all cases remained lower than when zinc alone was present. In the presence of cadmium the percentage of zinc in the kidneys was always lower than the value obtained for zinc alone, and that of the digestive tract did not increase. Contamination of eels treated with 18 and 50ppb of cadmium for 29 days, then contaminated by zinc-65 (5μCi/l) while maintaining the same low cadmium content, showed no significant difference in zinc 65 uptake in the two groups. The same applied to the body organs, and particularly the digestive tract and kidneys, where the highest activity levels were observed. By weight, muscles represented approximately 30% of the total contamination after 45 days [fr

  12. Characterization of organochlorine pesticides, brominated flame retardants and dioxin-like compounds in shellfish and eel from Fiji.

    Science.gov (United States)

    Lal, Vincent; Bridgen, Phil; Votadroka, Waisea; Raju, Rupantri; Aalbersberg, William

    2014-09-01

    This article gives an overview of a range of persistent organic pollutant chemical levels in shellfish (Batissa violacea and Anadara antiquata) species and eel (Gymnothorax flavimarginatus) from Fiji. As there is limited data in published literature to date, this paper reports first data on a range of persistent organic pollutants and highlights the more prominent POP chemicals present in marine biota in Fiji. A significant number of POP chemicals were detected (e.g. 17 PCDD/PCDF, 12dl-PCBs, organochlorine pesticides and brominated flame retardants), the concentrations found were generally low (e.g. parts per billion level). The low levels of contamination are indicative of a low input from long range and short-range transport as well as few local point sources. Also concentrations of POPs in eel and shellfish from Fiji are low in comparison to wild species in other regions and are within acceptable limits for POP chemicals in fish and fishery products set by the European Union. It describes also results of early studies on basic POPs levels in shellfish in several Pacific Island Countries, which generally show relatively low levels. Copyright © 2014 Elsevier B.V. All rights reserved.

  13. Parteid lubavad valimiste eel pealinlastele toetusi / Urmas Seaver

    Index Scriptorium Estoniae

    Seaver, Urmas, 1973-

    2005-01-01

    Erakonnad lubavad valimiste eel pealinlastele uusi soodustusi - alanevat maamaksu, lastehoiuraha, toetusi lastele ja pensionäridele. Näiteks Reformierakond lubab maamaksu alandada kaks korda. Lisa: Erakonnad peibutavad soodustustega

  14. Autonomic control of the heart in the Asian swamp eel (Monopterus albus)

    DEFF Research Database (Denmark)

    Iversen, Nina Kerting; Huong, Do Thi Thanh; Bayley, Mark

    2011-01-01

    The Asian swamp eel (Monopterus albus) is an air-breathing teleost with very reduced gills that uses the buccal cavity for air-breathing. Here we characterise the cardiovascular changes associated with the intermittent breathing pattern in M. albus and we study the autonomic control of the heart.......3 cm H2O). The autonomic control of the heart during water- and air-breathing was revealed by infusion of the β-adrenergic antagonist propranolol and muscarinic antagonist atropine (3 mg kg− 1) in eels instrumented with an arterial catheter. Inhibition of the sympathetic and parasympathetic...... innervations of the heart revealed a strong vagal tone on the heart of water-breathing eels and that the tachycardia during air-breathing is primarily mediated by withdrawal of cholinergic tone....

  15. EELS from organic crystalline materials

    International Nuclear Information System (INIS)

    Brydson, R; Seabourne, C R; Hondow, N; Eddleston, M D; Jones, W

    2014-01-01

    We report the use of the electron energy loss spectroscopy (EELS) for providing light element chemical composition information from organic, crystalline pharmaceutical materials including theophylline and paracetamol and discuss how this type of data can complement transmission electron microscopy (TEM) imaging and electron diffraction when investigating polymorphism. We also discuss the potential for the extraction of bonding information using electron loss near-edge structure (ELNES)

  16. In situ EELS and TEM observation of Al implanted with nitrogen ions

    International Nuclear Information System (INIS)

    Hojou, K.; Furuno, S.; Kushita, K.N.; Otsu, H.; Izui, K.

    1995-01-01

    Formation processes of Aluminum nitride (AIN) in Aluminum (AI) implanted with nitrogen were examined by in situ EELS and TEM observations during nitrogen ion implantation in an electron microscope at room temperature and 400 deg C. AIN phase was identified both by EDP and EELS after nitrogen ion implantation to 6 x 10 20 (N + )/m 2 . The observed peak (20.8 eV) in EELS spectra was identified as plasmon loss peak of AIN formed in AI. The binding energy of N ls in AI was found to shift by about 4 eV to the lower side with increasing nitrogen-ion fluence. Unreacted AI was also found to remain in the AIN films after high fluence implantation both at room temperature and 400 deg C. (authors). 11 refs., 5 figs., 2 tabs

  17. EEL spectroscopic tomography: towards a new dimension in nanomaterials analysis.

    Science.gov (United States)

    Yedra, Lluís; Eljarrat, Alberto; Arenal, Raúl; Pellicer, Eva; Cabo, Moisés; López-Ortega, Alberto; Estrader, Marta; Sort, Jordi; Baró, Maria Dolors; Estradé, Sònia; Peiró, Francesca

    2012-11-01

    Electron tomography is a widely spread technique for recovering the three dimensional (3D) shape of nanostructured materials. Using a spectroscopic signal to achieve a reconstruction adds a fourth chemical dimension to the 3D structure. Up to date, energy filtering of the images in the transmission electron microscope (EFTEM) is the usual spectroscopic method even if most of the information in the spectrum is lost. Unlike EFTEM tomography, the use of electron energy-loss spectroscopy (EELS) spectrum images (SI) for tomographic reconstruction retains all chemical information, and the possibilities of this new approach still remain to be fully exploited. In this article we prove the feasibility of EEL spectroscopic tomography at low voltages (80 kV) and short acquisition times from data acquired using an aberration corrected instrument and data treatment by Multivariate Analysis (MVA), applied to Fe(x)Co((3-x))O(4)@Co(3)O(4) mesoporous materials. This approach provides a new scope into materials; the recovery of full EELS signal in 3D. Copyright © 2012 Elsevier B.V. All rights reserved.

  18. Synergistic and singular effects of river discharge and lunar illumination on dam passage of upstream migrant yellow-phase American eels

    Science.gov (United States)

    Welsh, Stuart A.; Aldinger, Joni L.; Braham, Melissa A.; Zimmerman, Jennifer L.

    2016-01-01

    Monitoring of dam passage can be useful for management and conservation assessments of American eel, particularly if passage counts can be examined over multiple years. During a 7-year study (2007–2013) of upstream migration of American eels within the lower Shenandoah River (Potomac River drainage), we counted and measured American eels at the Millville Dam eel pass, where annual study periods were determined by the timing of the eel pass installation during spring or summer and removal during fall. Daily American eel counts were analysed with negative binomial regression models, with and without a year (YR) effect, and with the following time-varying environmental covariates: river discharge of the Shenandoah River at Millville (RDM) and of the Potomac River at Point of Rocks, lunar illumination (LI), water temperature, and cloud cover. A total of 17 161 yellow-phase American eels used the pass during the seven annual periods, and length measurements were obtained from 9213 individuals (mean = 294 mm TL, s.e. = 0.49, range 183–594 mm). Data on passage counts of American eels supported an additive-effects model (YR + LI + RDM) where parameter estimates were positive for river discharge (β = 7.3, s.e. = 0.01) and negative for LI (β = −1.9, s.e. = 0.34). Interestingly, RDM and LI acted synergistically and singularly as correlates of upstream migration of American eels, but the highest daily counts and multiple-day passage events were associated with increased RDM. Annual installation of the eel pass during late spring or summer prevented an early spring assessment, a period with higher RDM relative to those values obtained during sampling periods. Because increases in river discharge are climatically controlled events, upstream migration events of American eels within the Potomac River drainage are likely linked to the influence of climate variability on flow regime.

  19. The first success of glass eel production in the world: basic biology on fish reproduction advances new applied technology in aquaculture.

    Science.gov (United States)

    Kagawa, Hirohiko; Tanaka, Hideki; Ohta, Hiromi; Unuma, Tatsuya; Nomura, Kazuharu

    2005-04-01

    The eel has long been esteemed as an important food fish in the world, especially in Japan, and has been used as an experimental fish for many fields of fish physiology. However, the decreases in eel resources have been a serious concern in recent years. The catches of glass eels as seedlings for aquaculture have shown a long-term decrease in both Europe and East Asia. To increase eel resources, the development of techniques for artificial induction of maturation and spawning and rearing their larvae have been eagerly desired. Recent progress of reproductive physiology of fish, especially mechanisms of oocyte maturation and ovulation in female and of spermatozoa maturation in male, facilitate to establish techniques for hormonal induction of maturation and spawning in sexually immature eels. With persistent effort to development of rearing techniques of larvae, we have first succeeded to produce glass eel. These applied techniques are may contribute to understand the basic reproductive physiology of the eel.

  20. Migration des civelles d'anguilles (Anguilla anguilla L. dans les estuaires, modalités du phénomène et caractéristiques des individus

    Directory of Open Access Journals (Sweden)

    ELIE P.

    1994-10-01

    Full Text Available Nous avons réalisé une analyse de la littérature consacrée à la migration estuarienne de la civelle d'anguille (Anguilla anguilla L. et nous l'avons confrontée à des chroniques de données originales (abondance, structure en poids et en stades pigmentaires issues de l'estuaire de la Gironde. Ceci nous a permis de dégager la façon dont se déroule la migration. Il en ressort que les modalités du déroulement de la migration sont bien connues et relativement stables d'une année à l'autre, mais nous en sommes encore réduits à des hypothèses en ce qui concerne l'explication de son allure générale et de sa variabilité interannuelle. L'analyse des caractéristiques des individus montre une haute régularité interannuelle, on peut même parler d'un patron standard de l'évolution des individus en migration. L'action des principaux facteurs environnementaux sur les individus en migration apparaît assez nette, même si nous ne sommes pas en mesure actuellement de hiérarchiser leurs effets sur des flux migrants. Ce travail met en évidence la nécessité, pour appréhender les phénomènes migratoires et à plus forte raison pour établir un prémodèle de migration, de tenir compte de l'ensemble des aspects de la migration (tendance, facteurs modulateurs, épiphénomènes et caractéristiques des individus e n migration et d'utiliser des horloges écologiques adaptées.

  1. Transcript levels of members of the SLC2 and SLC5 families of glucose transport proteins in eel swimbladder tissue: the influence of silvering and the influence of a nematode infection.

    Science.gov (United States)

    Schneebauer, Gabriel; Mauracher, David; Fiechtner, Birgit; Pelster, Bernd

    2018-04-01

    The rate of glucose metabolism has been shown to be correlated to glucose uptake in swimbladder gas gland cells. Therefore, it is assumed that in the European eel silvering, i.e., the preparation of the eel for the spawning migration to the Sargasso Sea, coincides with an enhanced capacity for glucose uptake. To test this hypothesis expression of all known glucose transport proteins has been assessed at the transcript level in yellow and in silver eels, and we also included Anguillicola crassus infected swimbladders. Glucose uptake by rete mirabile endothelial cells could be crucial for the countercurrent exchange capacity of the rete. Therefore, this tissue was also included in our analysis. The results revealed expression of ten different members of the slc2 family of glucose transporters, of four slc5 family members, and of kiaa1919 in gas gland tissue. Glucose transporters of the slc2 family were expressed at very high level, and slc2a1b made up about 80% of all slc2 family members, irrespective of the developmental state or the infection status of the eel. Overall, the slc5 family contributed to only about 8% of all detected glucose transport transcripts in gas gland tissue, and the slc2 family to more than 85%. In rete capillaries, the contribution of sodium-dependent glucose transporters was significantly higher, leaving only 66% for the slc2 family of glucose transporters. Neither silvering nor the infection status had a significant effect on the expression of glucose transporters in swimbladder gas gland tissue, suggesting that glucose metabolism of eel gas gland cells may not be related to transcriptional changes of glucose transport proteins.

  2. Notes on the Moray Eels (Anguilliformes: Muraenidae) of Malaysia with Two New Records

    International Nuclear Information System (INIS)

    Kar-Hoe, L.; Muhammad Ali Syed Hussein; Ving-Ching, C.; Sasekumar, A.

    2015-01-01

    Two new records of moray eels (Muraenidae), Gymnothorax margaritophorus Bleeker, 1864 and Strophidon sathete (Hamilton 1822), are reported for Malaysia. They are represented by two specimens each, all collected from Sabah waters. The present study also provides the current taxonomic and distributional information of the Malaysian moray eels. To date, there are 33 species belonging to six genera of the Muraenidae in Malaysian waters based on the published records. (author)

  3. TEM and EELS study of deuterated carbon: application to the fuel retention in tokamaks; Etude couplee MET-EELS du carbone deutere: application a la retention du combustible dans les tokamaks

    Energy Technology Data Exchange (ETDEWEB)

    Bernier, N

    2007-12-15

    We developed a methodology, based on the combination of TEM and EELS techniques, for a structural and chemical characterization, at a high spatial resolution, of a wide range of carbon materials. We i) optimized, in the framework of theoretical models, the sp2 fraction quantification from pure carbons by EELS ii) transferred this quantification to deuterated amorphous carbon layers iii) showed, from graphitized carbons, how the TEM-EELS combination allows to detect low concentrations of implanted D. Due to the accomplishment of these developments, we applied our approach to the study of D retention in composites C/C, which are the plasma-facing materials in TS. We showed that specific localized retention sites correspond to relatively large ({approx} 3 mm.) cracks between fibres and matrix; such cracks offer a simple and direct path for deuterated amorphous carbon. The particle balance performed in TS is discussed in the light of this trapping mechanism. (author)

  4. Regional variation in energy storage strategies in American glass eels from Eastern Canada.

    Science.gov (United States)

    Gaillard, Mélanie; Bernatchez, Louis; Tremblay, Réjean; Audet, Céline

    2015-10-01

    Energy status was analyzed in glass eels captured during two early waves of arrival at the mouths of the Mersey River, Nova Scotia, Canada (MR), and Grande-Rivière-Blanche, Québec, Canada (GRB), and according to their salinity preference (freshwater, brackish, or saltwater). Glass eels captured in the GRB estuary were larger, more pigmented, and exhibited higher whole-body glycogen, phospholipid, and sterol and wax ester contents. Those from MR had a higher condition index and a higher whole-body triacylglycerol content, suggesting different patterns of storage and/or use of energy reserves. Within a river, a delay of two weeks in estuarine arrival was characterized by significantly lower energy reserves. No differences in energy storage were observed according to salinity preference. Thus, the results revealed the occurrence of different energy storage strategies according to glass eel migration distance and duration, but not according to salinity preference. Copyright © 2015 Elsevier Inc. All rights reserved.

  5. Imported Asian swamp eels (Synbranchidae: Monopterus) in North American live food markets: Potential vectors of non-native parasites

    Science.gov (United States)

    Nico, Leo G.; Sharp, Paul; Collins, Timothy M.

    2011-01-01

    Since the 1990s, possibly earlier, large numbers of Asian swamp eels (Synbranchidae: Monopterus spp.), some wild-caught, have been imported live from various countries in Asia and sold in ethnic food markets in cities throughout the USA and parts of Canada. Such markets are the likely introduction pathway of some, perhaps most, of the five known wild populations of Asian swamp eels present in the continental United States. This paper presents results of a pilot study intended to gather baseline data on the occurrence and abundance of internal macroparasites infecting swamp eels imported from Asia to North American retail food markets. These data are important in assessing the potential role that imported swamp eels may play as possible vectors of non-native parasites. Examination of the gastrointestinal tracts and associated tissues of 19 adult-sized swamp eels—identified as M. albus "Clade C"—imported from Vietnam and present in a U.S. retail food market revealed that 18 (95%) contained macroparasites. The 394 individual parasites recovered included a mix of nematodes, acanthocephalans, cestodes, digeneans, and pentastomes. The findings raise concern because of the likelihood that some parasites infecting market swamp eels imported from Asia are themselves Asian taxa, some possibly new to North America. The ecological risk is exacerbated because swamp eels sold in food markets are occasionally retained live by customers and a few reportedly released into the wild. For comparative purposes, M. albus "Clade C" swamp eels from a non-native population in Florida (USA) were also examined and most (84%) were found to be infected with internal macroparasites. The current level of analysis does not allow us to confirm whether these are non-native parasites.

  6. Treatment of trichodiniasis in eel ( Anguilla anguilla ) reared in recirculation systems in Denmark : alternatives to formaldehyde

    DEFF Research Database (Denmark)

    Madsen, H.C.K.; Buchmann, Kurt; Mellergaard, Stig

    2000-01-01

    parasiticidal effect: acriflavin (25 ppm), bithionol (0.1 ppm), chloramine T (50 ppm), Detarox AP(R) (45 ppm), malachite green (1 ppm), raw garlic (200 ppm), potassium permanganate (20 ppm) and Virkon PF(R) vet. (20 ppm). Preliminary screening revealed that the anthelmintic, bithionol, and the decomposable...

  7. Performance and optimisation of trickling filters on eel farms

    NARCIS (Netherlands)

    Kamstra, A.; Heul, van der J.W.; Nijhof, M.

    1998-01-01

    The design of trickling filters used on commercial eel farms differs considerably with respect to dimensions, hydraulic and substrate loads and filter medium applied. In this paper, a model, developed for ammonium removal in a pilot-scale trickling filter, has been validated for a range of

  8. Some aspects on the reproductive cycle of European conger eel, Conger conger (Linnaeus, 1758 (Osteichthyes, Anguilliformes, Congridae captured from Western Algerian coasts: a histological description of spermatogenesis

    Directory of Open Access Journals (Sweden)

    Abi-ayad Sidi-Mohammed El-Amine

    2011-09-01

    Full Text Available The aim of this work was to study the annual reproductive cycle of European conger eel (Conger conger,Linnaeus, 1758 through analysis and description of spermatogenesis. A sample of 168 males was capturedbetween September 2008 and August 2009 from the Western coast of Algeria, from Béni Saf. Fish length andweight varied between 26.20-112 cm and 0.45-3.44 kg, respectively.Condition factors (K, gonadosomatic index (G.S.I. and hepatosomatic index (H.S.I. were calculatedmonthly. Factor K reached the minimum in August/September (0.10% corresponding to reproductive periodand a maximum in January (0.18%. Although G.S.I. values revealed to be statistically not significant, therewere two peaks for G.S.I., the first in March, denoting the beginning of spermatogenesis, and the second inAugust/September, indicating the reproduction period. H.S.I. reached a peak in December (1.90%, then thevalue decreased to a minimum in April.Histological analysis of testis allowed us to distinguish 5 stages summarized as follows: Stage 1:Spermatogonia A; Stage 2: Spermatogonia B; Stage 3: Spermatocytes and spermatids; Stage 4: Spermatocytes,spermatids and spermatozoa (cytodifferentiation of spermatids into spermatozoa; Stage 5: Spermatozoa(spermiogenesis or cytodifferentiation of spermatids into spermatozoa.

  9. EEL Calculations and Measurements of Graphite and Graphitic-CNx Core-Losses

    International Nuclear Information System (INIS)

    Seepujak, A; Bangert, U; Harvey, A J; Blank, V D; Kulnitskiy, B A; Batov, D V

    2006-01-01

    Core EEL spectra of MWCNTs (multi-wall carbon nanotubes) grown in a nitrogen atmosphere were acquired utilising a dedicated STEM equipped with a Gatan Enfina system. Splitting of the carbon K-edge π* resonance into two peaks provided evidence of two nondegenerate carbon bonding states. In order to confirm the presence of a CN x bonding state, a full-potential linearised augmented plane-wave method was utilised to simulate core EEL spectra of graphite and graphitic-CN x compounds. The simulations confirmed splitting of the carbon K-edge π* resonance in graphitic-CN x materials, with the pristine graphite π* resonance remaining unsplit. The simulations also confirmed the increasing degree of amorphicity with higher concentrations (25%) of substitutional nitrogen in graphite

  10. A new method to grade glass eels according to their appetite

    Directory of Open Access Journals (Sweden)

    ANGELIDIS Panagiotis

    2007-10-01

    Full Text Available To optimize fish growth grading is strongly recommended. In our experiment the glass eels (450,000, mean individual body weight 0.31+0.22g sd start feeding for 15 and then they were selected according to their appetite. After selection all the fish of the 10 tanks were fed at liberty and they were weighed on the 10th and 30thday after the grade day. No differences were seen in the fish weight of the eels of the two groups on the 10th day (P>0.01 but the selected fish doubled their weight on the 30th day (selected fish 0.71+0.22g sd, unselected 0.39+0.20g sd, P<0.01.

  11. TEM and EELS study of deuterated carbon: application to the fuel retention in tokamaks

    International Nuclear Information System (INIS)

    Bernier, N.

    2007-12-01

    We developed a methodology, based on the combination of TEM and EELS techniques, for a structural and chemical characterization, at a high spatial resolution, of a wide range of carbon materials. We i) optimized, in the framework of theoretical models, the sp2 fraction quantification from pure carbons by EELS ii) transferred this quantification to deuterated amorphous carbon layers iii) showed, from graphitized carbons, how the TEM-EELS combination allows to detect low concentrations of implanted D. Due to the accomplishment of these developments, we applied our approach to the study of D retention in composites C/C, which are the plasma-facing materials in TS. We showed that specific localized retention sites correspond to relatively large (∼ 3 mm.) cracks between fibres and matrix; such cracks offer a simple and direct path for deuterated amorphous carbon. The particle balance performed in TS is discussed in the light of this trapping mechanism. (author)

  12. RECRUTEMENT DES CIVELLES (ANGUILLA ANGUILLA SUR LA COTE MEDITERRANEENNE FRANÇAISE : ANALYSE COMPAREE DES CARACTERISTIQUES BIOMETRIQUES ET PIGMENTAIRES DES SAISONS 1974-75 ET 2000-01.

    Directory of Open Access Journals (Sweden)

    LEFEBVRE F.

    2003-07-01

    Full Text Available Une campagne d’échantillonnage des civelles Anguilla anguilla a été menée de novembre 2000 à mai 2001 au grau de la Fourcade (Saintes-Maries-de-la-Mer, côte méditerranéenne française. Des civelles ont été capturées sur toute la période d’échantillonnage, mais les maxima d’abondance se situent en janvier-février et, dans une moindre mesure, en avril. Afin d’optimiser le recrutement dans les lagunes littorales intérieures, la mesure de gestion proposée est donc de favoriser l’ouverture des martelières au milieu de l’hiver. Le suivi des proportions mensuelles des différents stades pigmentaires (de V A à VI A4 permet de conclure à un vieillissement généralisé des civelles en recrutement de novembre à mars, puis à l’arrivée d’un deuxième flux de civelles jeunes en avril. Parallèlement, il est observé une diminution très nette des masses et des longueurs moyennes mensuelles, et ce, même en ne considérant qu’un stade pigmentaire donné (en l’occurrence V B. Ces résultats sur l’évolution des caractéristiques biométriques et pigmentaires sont en accord avec les deux séries de travaux déjà menés sur la façade méditerranéenne française (années 30 et 70, ainsi qu’avec les données publiées en différents points de la façade atlantique. L’analyse comparée de ces données avec celles issues de la dernière étude en date sur la côte méditerranéenne française (Bages-Sigean, Languedoc-Roussillon, campagne 1974-75 ; LECOMTE-FINIGER, 1976 montre une composition pigmentaire mensuelle totalement différente, et révèle une diminution significative de la longueur des civelles, de l’ordre de 5 % en 25 ans.

  13. Impact of dietary fatty acids on muscle composition, liver lipids, milt composition and sperm performance in European eel

    DEFF Research Database (Denmark)

    Butts, Ian; Baeza, R.; Støttrup, Josianne

    2015-01-01

    of dietary regime on muscle composition, and liver lipids prior to induced maturation, and the resulting sperm composition and performance. To accomplish this fish were reared on three "enhanced" diets and one commercial diet, each with different levels of fatty acids, arachidonic acid (ARA......), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA). Neutral lipids from the muscle and liver incorporated the majority of the fatty acid profile, while phospholipids incorporated only certain fatty acids. Diet had an effect on the majority of sperm fatty acids, on the total volume of extractable milt...... induced medium milt volumes but had the highest sperm motility. EPA also seems important for sperm quality parameters since diets with higher EPA percentages had a higher volume of milt and higher sperm motility. In conclusion, dietary fatty acids had an influence on fatty acids in the tissues of male eel...

  14. Ecological study of the migration of eel by synchrotron radiation induced X-ray fluorescence imaging of otoliths

    International Nuclear Information System (INIS)

    Nakai, I.; Iwata, R.; Tsukamoto, K.

    1999-01-01

    Synchrotron radiation-induced X-ray fluorescence imaging is suitable for determining the distribution of trace elements in fish otoliths. The Sr/Ca ratio in an otolith is an indicator of salinity changes and can be used to clarify the migration history of the eel, a catadromous fish. The otoliths of eel collected from the Tone and Elbe rivers exhibited a typical catadromous pattern, i.e. birth and breeding occurred in the ocean, but the remainder of their lives was spent in fresh water. In contrast, eels from the East China Sea and North Sea exhibited an unusual sea-locking phenomenon, as they appear to have remained in marine habitats throughout their lives. (Copyright (c) 1999 Elsevier Science B.V., Amsterdam. All rights reserved.)

  15. Illegal trade of regulated and protected aquatic species in the Philippines detected by DNA barcoding.

    Science.gov (United States)

    Asis, Angelli Marie Jacynth M; Lacsamana, Joanne Krisha M; Santos, Mudjekeewis D

    2016-01-01

    Illegal trade has greatly affected marine fish stocks, decreasing fish populations worldwide. Despite having a number of aquatic species being regulated, illegal trade still persists through the transport of dried or processed products and juvenile species trafficking. In this regard, accurate species identification of illegally traded marine fish stocks by DNA barcoding is deemed to be a more efficient method in regulating and monitoring trade than by morphological means which is very difficult due to the absence of key morphological characters in juveniles and processed products. Here, live juvenile eels (elvers) and dried products of sharks and rays confiscated for illegal trade were identified. Twenty out of 23 (87%) randomly selected "elvers" were identified as Anguilla bicolor pacifica and 3 (13%) samples as Anguilla marmorata. On the other hand, 4 out of 11 (36%) of the randomly selected dried samples of sharks and rays were Manta birostris. The rest of the samples were identified as Alopias pelagicus, Taeniura meyeni, Carcharhinus falciformis, Himantura fai and Mobula japonica. These results confirm that wild juvenile eels and species of manta rays are still being caught in the country regardless of its protected status under Philippine and international laws. It is evident that the illegal trade of protected aquatic species is happening in the guise of dried or processed products thus the need to put emphasis on strengthening conservation measures. This study aims to underscore the importance of accurate species identification in such cases of illegal trade and the effectivity of DNA barcoding as a tool to do this.

  16. Spatial patterns and temporal trends in the fisheries landings of the Messolonghi-Etoliko lagoons (Western Greek Coast

    Directory of Open Access Journals (Sweden)

    George Katselis

    2003-12-01

    Full Text Available The Messolonghi-Etoliko lagoon is one of the largest lagoon system in the northern Mediterranean coast. This area contains six clearly distinct lagoons with different topographic and hydrological features. The fishery landings of the lagoons are based on the ontogenic and seasonal migrations of the species. The total annual fishery landings of the barrier fish traps are estimated as 195 mt and are mainly composed of 16 species belonging to 8 families. Eel (Anguilla anguilla, the four species of Mugilidae (Liza saliens, L. aurata, L. ramada and Mugil cephalus, the two species of Sparidae (Sparus aurata and Diplodus annularis and one species of Mullidae (Mullus barbatus represent more than 92% of the total annual landings. The composition of the fishery landings varies between lagoons. The cluster analysis showed three groups of lagoons. The first group comprised lagoons in which the landings were dominated by eel, the second group was dominated by Mugilidae species and S. aurata, and the third by L. ramada and M. cephalus. The diversity index of the fishery landings is fairly constant in time, except for the Etoliko lagoon, where repeated anoxic crises decreased the diversity index value to almost zero in 1992. All the landing series showed a dominant annual cycle. Two seasonal patterns of the fishery landings were observed and linked to the fish spawning behaviour and/or their reaction to environmental forcings. The first one concerns species caught from summer to early autumn and the second pattern concerns species trapped during their autumn to winter offshore migration.

  17. Diseases of eels in an international perspective: Workshop on Eel Diseases at the 15th International Conference on Diseases of Fish and Shellfish, Split, Croatia, 2011

    NARCIS (Netherlands)

    Haenen, O.L.M.; Mladineo, I.; Konecny, R.; Yoshimizu, M.; Groman, D.; Munoz, P.; Saraiva, A.; Bergmann, S.M.; Beurden, van S.J.

    2012-01-01

    In recent years, significant attention has been assigned to the decline in the wild freshwater eel stocks worldwide. Possible causative factors include fisheries (overfishing), habitat loss, migration barriers, and chemical pollution, and/or a combination of these factors. Infectious diseases

  18. Applications of STEM-EELS to complex oxides

    KAUST Repository

    Gá zquez, Jaume; Sá nchez-Santolino, Gabriel; Biškup, Neven; Roldá n, Manuel A.; Cabero, M.; Pennycook, Stephen J.; Varela, Marí a

    2016-01-01

    In this chapter we will review a few examples of applications of atomic resolution aberration corrected scanning transmission electron microscopy (STEM) and electron energy-loss spectroscopy (EELS) to complex oxide materials. These are most challenging systems where subtle changes in structure or chemistry may result in colossal responses in macroscopic physical behavior. Here, we will review how atomic resolution compositional mapping can be achieved in manganite thin films and single crystals, highlighting the importance of considering artifacts during quantification. Besides, minor changes in near edge fine structure may take place when the crystalline environment, and hence nearest neighbor configuration, is modified. These can also be tracked by atomic resolution EELS, as will be shown through the study of binary Fe oxides. Also, examples regarding the study of distributions of point defects such as O vacancies in cobaltite thin films will be discussed. In these materials, a combination of epitaxial strain and defects may promote physical behaviors not present in bulk, such as the stabilization of unexpected spin state superlattices. Last, a study of extended defects such as dislocation lines will be reviewed. In particular, we will show how chemical segregation at dislocation cores in yttria-stabilized zirconia grain boundaries results in the generation of static O vacancies that affect the local electrostatic potential and hence, the macroscopic ionic conduction properties. © 2016.

  19. Applications of STEM-EELS to complex oxides

    KAUST Repository

    Gázquez, Jaume

    2016-06-26

    In this chapter we will review a few examples of applications of atomic resolution aberration corrected scanning transmission electron microscopy (STEM) and electron energy-loss spectroscopy (EELS) to complex oxide materials. These are most challenging systems where subtle changes in structure or chemistry may result in colossal responses in macroscopic physical behavior. Here, we will review how atomic resolution compositional mapping can be achieved in manganite thin films and single crystals, highlighting the importance of considering artifacts during quantification. Besides, minor changes in near edge fine structure may take place when the crystalline environment, and hence nearest neighbor configuration, is modified. These can also be tracked by atomic resolution EELS, as will be shown through the study of binary Fe oxides. Also, examples regarding the study of distributions of point defects such as O vacancies in cobaltite thin films will be discussed. In these materials, a combination of epitaxial strain and defects may promote physical behaviors not present in bulk, such as the stabilization of unexpected spin state superlattices. Last, a study of extended defects such as dislocation lines will be reviewed. In particular, we will show how chemical segregation at dislocation cores in yttria-stabilized zirconia grain boundaries results in the generation of static O vacancies that affect the local electrostatic potential and hence, the macroscopic ionic conduction properties. © 2016.

  20. Construction of a BAC library and identification of Dmrt1 gene of the rice field eel, Monopterus albus

    International Nuclear Information System (INIS)

    Jang Songhun; Zhou Fang; Xia Laixin; Zhao Wei; Cheng Hanhua; Zhou Rongjia

    2006-01-01

    A bacterial artificial chromosome (BAC) library was constructed using nuclear DNA from the rice field eel (Monopterus albus). The BAC library consists of a total of 33,000 clones with an average insert size of 115 kb. Based on the rice field eel haploid genome size of 600 Mb, the BAC library is estimated to contain approximately 6.3 genome equivalents and represents 99.8% of the genome of the rice field eel. This is first BAC library constructed from this species. To estimate the possibility of isolating a specific clone, high-density colony hybridization-based library screening was performed using Dmrt1 cDNA of the rice field eel as a probe. Both library screening and PCR identification results revealed three positive BAC clones which were overlapped, and formed a contig covering the Dmrt1 gene of 195 kb. By sequence comparisons with the Dmrt1 cDNA and sequencing of first four intron-exon junctions, Dmrt1 gene of the rice field eel was predicted to contain four introns and five exons. The sizes of first and second intron are 1.5 and 2.6 kb, respectively, and the sizes of last two introns were predicted to be about 20 kb. The Dmrt1 gene structure was conserved in evolution. These results also indicate that the BAC library is a useful resource for BAC contig construction and molecular isolation of functional genes

  1. Influence of the invasive Asian clam Corbicula fluminea (Bivalvia: Corbiculidae) on estuarine epibenthic assemblages

    Science.gov (United States)

    Ilarri, M. I.; Souza, A. T.; Antunes, C.; Guilhermino, L.; Sousa, R.

    2014-04-01

    One of the most widespread invasive alien species (IAS) in aquatic ecosystems is the Asian clam Corbicula fluminea. Several studies have shown that C. fluminea can cause large-scale changes in macrozoobenthic assemblages; however, very few attempted to investigate the effects of this IAS on mobile epibenthic species, such as fishes and crustaceans. In this context, the influence of C. fluminea on epibenthic species was investigated during one year by comparing the associated epibenthic fauna in three nearby sites of the Minho estuary (NW of the Iberian Peninsula), wherein the abiotic conditions are similar but the density of the Asian clam is highly different. From a total of 13 species, six were significantly influenced by C. fluminea; five responded positively, namely the brown shrimp Crangon crangon, the European eel Anguilla anguilla, the common goby Pomatoschistus microps, the brown trout Salmo trutta fario and the great pipefish Syngnathus acus, whereas the shore crab Carcinus maenas was negatively influenced. However, stomach contents analysis revealed that fish and crustacean species do not feed on C. fluminea, suggesting that this IAS is still not a large component of the diet of higher trophic levels in this estuarine ecosystem. Our results suggest that the structure provided by C. fluminea shells is likely to be one of the main factors responsible for the differences observed. C. fluminea physical structure seems to influence the epibenthic associated fauna, when found in densities higher than 1000 ind./m2, with sedentary small-bodied crustaceans and fishes being mainly attracted by the increasing in habitat complexity and consequent enhancement of heterogeneity and shelter availability.

  2. Teaching Population Growth Using Cultures of Vinegar Eels, "Turbatrix aceti" (Nematoda)

    Science.gov (United States)

    Wallace, Robert L.

    2005-01-01

    A simple laboratory exercise is presented that follows the population growth of the common vinegar eel, "Turbatrix aceti" (Nematoda), in a microcosm using a simple culture medium. It lends itself to an exercise in a single semester course. (Contains 4 figures.)

  3. Silicone passive equilibrium samplers as ‘chemometers’ in eels and sediments of a Swedish lake

    DEFF Research Database (Denmark)

    Jahnke, Annika; Mayer, Philipp; McLachlan, Michael S.

    2014-01-01

    Passive equilibrium samplers deployed in two or more media of a system and allowed to come to equilibrium can be viewed as ‘chemometers’ that reflect the difference in chemical activities of contaminants between the media. We applied silicone-based equilibrium samplers to measure relative chemica...... diagenesis and sorption to phytoplankton. The ‘chemometer’ approach has the potential to become a powerful tool to study the thermodynamic controls on persistent organic chemicals in the environment and should be extended to other environmental compartments.......Passive equilibrium samplers deployed in two or more media of a system and allowed to come to equilibrium can be viewed as ‘chemometers’ that reflect the difference in chemical activities of contaminants between the media. We applied silicone-based equilibrium samplers to measure relative chemical...... activities of seven ‘indicator’ polychlorinated biphenyls (PCBs) and hexachlorobenzene in eels and sediments from a Swedish lake. Chemical concentrations in eels and sediments were also measured using exhaustive extraction methods. Lipid-normalized concentrations in eels were higher than organic carbon...

  4. Integrating habitat restoration and fisheries management : A small-scale case-study to support EEL conservation at the global scale

    Directory of Open Access Journals (Sweden)

    Ciccotti E.

    2013-02-01

    Full Text Available The aim of this work was to develop a methodological framework for the management of local eel stocks that integrates habitat restoration with optimal fishery management. The Bolsena lake (Viterbo, Italy and its emissary, the river Marta, were taken as a reference system. The river flows in the Mediterranean sea but its course is fragmented by a number of dams built in the past century preventing eel migration from and to the sea. Eel fishery in the Bolsena lake is thus sustained by periodic stocking of glass eels caught at the Marta river estuary. A detailed demographic model was applied to simulate fishery yields and potential spawner escapement under different recruitment and management scenarios. It was estimated that the high exploitation rates occurring in the nineties reduced the potential spawner escapement from the Bolsena lake to less than 1 t; under current harvesting rates, the potential spawner escapement is estimated in about 12 t while in pristine conditions (i.e. high recruitment and no fishing estimated spawner escapement is about 21 t. This analysis thus showed that current fishery management would comply with the 40% spawner escapement requirement of the EU regulation 1100/2007 if the connections between the Bolsena lake emissary and the sea were fully re-established. This confirms the opportunity of an integrated approach to management at the catchment area level scale for eel populations, that shall hopefully contribute to the conservation of the global stock.

  5. High-resolution EELS investigation of the electronic structure of ilmenites

    NARCIS (Netherlands)

    Radtke, G.; Lazar, S.; Botton, G.A.

    2006-01-01

    The electronic structure of a series of compounds belonging to the ilmenite family is investigated using high resolution electron energy loss spectroscopy (EELS). The energy loss near edge structure (ELNES) of the O-K, Ti-L23 and transition metal L23 edges have been recorded in MnTiO3, FeTiO3,

  6. Fe and O EELS Studies of Ion Irradiated Murchison CM2 Carbonaceous Chondrite Matrix

    Science.gov (United States)

    Keller, L. P.; Christofferson, R.; Dukes, C. A.; Baragiola, R. A.; Rahman, Z.

    2015-01-01

    Introduction: The physical and chemical response of hydrated carbonaceous chondrite materials to space weathering processes is poorly understood. Improving this understanding is a key part of establishing how regoliths on primitive carbonaceous asteroids respond to space weathering processes, knowledge that supports future sample return missions (Hayabusa 2 and OSIRISREx) that are targeting objects of this type. We previously reported on He+ irradiation of Murchison matrix and showed that the irradiation resulted in amorphization of the matrix phyllosilicates, loss of OH, and surface vesiculation. Here, we report electron energy-loss spectroscopy (EELS) measurements of the irradiated material with emphasis on the Fe and O speciation. Sample and Methods: A polished thin section of the Murchison CM2 carbonaceous chondrite was irradiated with 4 kilovolts He(+) (normal incidence) to a total dose of 1 x 10(exp 18) He(+) per square centimeter. We extracted thin sections from both irradiated and unirradiated regions in matrix using focused ion beam (FIB) techniques with electron beam deposition for the protective carbon strap to minimize surface damage artifacts from the FIB milling. The FIB sections were analyzed using a JEOL 2500SE scanning and transmission electron microscope (STEM) equipped with a Gatan Tridiem imaging filter. EELS spectra were collected from 50 nanometer diameter regions with an energy resolution of 0.7 electronvolts FWHM at the zero loss. EELS spectra were collected at low electron doses to minimize possible artifacts from electron-beam irradiation damage. Results and Discussion: Fe L (sub 2,3) EELS spectra from matrix phyllosilicates in CM chondrites show mixed Fe(2+)/Fe(3+) oxidation states with Fe(3+)/Sigma Fe approximately 0.5. Fe L(sub 2,3) spectra from the irradiated/ amorphized matrix phyllosilicates show higher Fe(2+)/Fe(3+) ratios compared to spectra obtained from pristine material at depths beyond the implantation/amorphization layer. We

  7. Isotocin Regulates Growth Hormone but Not Prolactin Release From the Pituitary of Ricefield Eels

    Directory of Open Access Journals (Sweden)

    Wei Yang

    2018-04-01

    Full Text Available The neurohypophyseal hormone oxytocin (Oxt has been shown to stimulate prolactin (Prl synthesis and release from the adenohypophysis in rats. However, little is known about the functional roles of Oxt-like neuropeptides in the adenohypophysis of non-mammalian vertebrates. In this study, cDNAs encoding ricefield eel oxytocin-like receptors (Oxtlr, namely isotocin (Ist receptor 1 (Istr1 and 2 (Istr2, were isolated and specific antisera were generated, respectively. RT-PCR and Western blot analysis detected the presence of both Istr1 and Istr2 in the brain and pituitary, but differential expression in some peripheral tissues, including the liver and kidney, where only Istr1 was detected. In the pituitary, immunoreactive Istr1 and Istr2 were differentially distributed, with the former mainly in adenohypophyseal cell layers adjacent to the neurohypophysis, whereas the latter in peripheral areas of the adenohypophysis. Double immunofluorescent images showed that immunostaining of Istr1, but not Istr2 was localized to growth hormone (Gh cells, but neither of them was expressed in Prl cells. Ist inhibited Gh release in primary pituitary cells of ricefield eels and increased Gh contents in the pituitary gland of ricefield eels at 6 h after in vivo administration. Ist inhibition of Gh release is probably mediated by cAMP, PKC/DAG, and IP3/Ca2+ pathways. In contrast, Ist did not affect either prl gene expression or Prl contents in primary pituitary cells. Results of this study demonstrated that Ist may not be involved in the regulation of Prl, but inhibit Gh release via Istr1 rather than Istr2 in ricefield eels, and provided evidence for the direct regulation of Gh cells by oxytocin-like neuropeptides in the pituitary of non-mammalian vertebrates.

  8. Isotocin Regulates Growth Hormone but Not Prolactin Release From the Pituitary of Ricefield Eels

    Science.gov (United States)

    Yang, Wei; Zhang, Ning; Shi, Boyang; Zhang, Shen; Zhang, Lihong; Zhang, Weimin

    2018-01-01

    The neurohypophyseal hormone oxytocin (Oxt) has been shown to stimulate prolactin (Prl) synthesis and release from the adenohypophysis in rats. However, little is known about the functional roles of Oxt-like neuropeptides in the adenohypophysis of non-mammalian vertebrates. In this study, cDNAs encoding ricefield eel oxytocin-like receptors (Oxtlr), namely isotocin (Ist) receptor 1 (Istr1) and 2 (Istr2), were isolated and specific antisera were generated, respectively. RT-PCR and Western blot analysis detected the presence of both Istr1 and Istr2 in the brain and pituitary, but differential expression in some peripheral tissues, including the liver and kidney, where only Istr1 was detected. In the pituitary, immunoreactive Istr1 and Istr2 were differentially distributed, with the former mainly in adenohypophyseal cell layers adjacent to the neurohypophysis, whereas the latter in peripheral areas of the adenohypophysis. Double immunofluorescent images showed that immunostaining of Istr1, but not Istr2 was localized to growth hormone (Gh) cells, but neither of them was expressed in Prl cells. Ist inhibited Gh release in primary pituitary cells of ricefield eels and increased Gh contents in the pituitary gland of ricefield eels at 6 h after in vivo administration. Ist inhibition of Gh release is probably mediated by cAMP, PKC/DAG, and IP3/Ca2+ pathways. In contrast, Ist did not affect either prl gene expression or Prl contents in primary pituitary cells. Results of this study demonstrated that Ist may not be involved in the regulation of Prl, but inhibit Gh release via Istr1 rather than Istr2 in ricefield eels, and provided evidence for the direct regulation of Gh cells by oxytocin-like neuropeptides in the pituitary of non-mammalian vertebrates.

  9. Ammonia stress under high environmental ammonia induces Hsp70 and Hsp90 in the mud eel, Monopterus cuchia.

    Science.gov (United States)

    Hangzo, Hnunlalliani; Banerjee, Bodhisattwa; Saha, Shrabani; Saha, Nirmalendu

    2017-02-01

    The obligatory air-breathing mud eel (Monopterus cuchia) is frequently being challenged with high environmental ammonia (HEA) exposure in its natural habitats. The present study investigated the possible induction of heat shock protein 70 and 90 (hsp70, hsc70, hsp90α and hsp90β) genes and more expression of Hsp70 and Hsp90 proteins under ammonia stress in different tissues of the mud eel after exposure to HEA (50 mM NH 4 Cl) for 14 days. HEA resulted in significant accumulation of toxic ammonia in different body tissues and plasma, which was accompanied with the stimulation of oxidative stress in the mud eel as evidenced by more accumulation of malondialdehyde (MDA) and hydrogen peroxide (H 2 O 2 ) during exposure to HEA. Further, hyper-ammonia stress led to significant increase in the levels of mRNA transcripts for inducible hsp70 and hsp90α genes and also their translated proteins in different tissues probably as a consequence of induction of hsp70 and hsp90α genes in the mud eel. However, hyper-ammonia stress was neither associated with any significant alterations in the levels of mRNA transcripts for constitutive hsc70 and hsp90β genes nor their translated proteins in any of the tissues studied. More abundance of Hsp70 and Hsp90α proteins might be one of the strategies adopted by the mud eel to defend itself from the ammonia-induced cellular damages under ammonia stress. Further, this is the first report of ammonia-induced induction of hsp70 and hsp90α genes under hyper-ammonia stress in any freshwater air-breathing teleost.

  10. Adaptive Evolution of Eel Fluorescent Proteins from Fatty Acid Binding Proteins Produces Bright Fluorescence in the Marine Environment.

    Directory of Open Access Journals (Sweden)

    David F Gruber

    Full Text Available We report the identification and characterization of two new members of a family of bilirubin-inducible fluorescent proteins (FPs from marine chlopsid eels and demonstrate a key region of the sequence that serves as an evolutionary switch from non-fluorescent to fluorescent fatty acid-binding proteins (FABPs. Using transcriptomic analysis of two species of brightly fluorescent Kaupichthys eels (Kaupichthys hyoproroides and Kaupichthys n. sp., two new FPs were identified, cloned and characterized (Chlopsid FP I and Chlopsid FP II. We then performed phylogenetic analysis on 210 FABPs, spanning 16 vertebrate orders, and including 163 vertebrate taxa. We show that the fluorescent FPs diverged as a protein family and are the sister group to brain FABPs. Our results indicate that the evolution of this family involved at least three gene duplication events. We show that fluorescent FABPs possess a unique, conserved tripeptide Gly-Pro-Pro sequence motif, which is not found in non-fluorescent fatty acid binding proteins. This motif arose from a duplication event of the FABP brain isoforms and was under strong purifying selection, leading to the classification of this new FP family. Residues adjacent to the motif are under strong positive selection, suggesting a further refinement of the eel protein's fluorescent properties. We present a phylogenetic reconstruction of this emerging FP family and describe additional fluorescent FABP members from groups of distantly related eels. The elucidation of this class of fish FPs with diverse properties provides new templates for the development of protein-based fluorescent tools. The evolutionary adaptation from fatty acid-binding proteins to fluorescent fatty acid-binding proteins raises intrigue as to the functional role of bright green fluorescence in this cryptic genus of reclusive eels that inhabit a blue, nearly monochromatic, marine environment.

  11. Visziekten in Nederland, een terugblik: 20 jaar diagnoses bij het visziektenlaboratorium

    NARCIS (Netherlands)

    Haenen, O.L.M.

    2005-01-01

    Enkele in Nederland veel voorkomende ziekten bij vissen van de afgelopen twintig jaar. Eel Virus European, Eel Virus European X, Herpesvirus van Paling, Infectieuze Hematopoietische Necrose, Infectieuze Pancreatische Necrose, Koi Herpes Virus, Snoekvirus, Spring Viremia of Carp, Virale

  12. Application of an immunoperoxidase staining method for detection of 7,8-dihydro-8-oxodeoxyguanosine as a biomarker of chemical-induced oxidative stress in marine organisms

    International Nuclear Information System (INIS)

    Machella, Nicola; Regoli, Francesco; Cambria, Antonio; Santella, Regina M.

    2004-01-01

    7,8-Dihydro-8-oxodeoxyguanosine (8-oxo-dG) is a typical modification of DNA caused by oxygen free radicals and can be an useful biomarker for pollutants inducing oxidative stress. An immunoperoxidase method using monoclonal antibody 1F7 toward 8-oxo-dG was applied to tissues and smeared cells of marine organisms for detection and quantification of oxidative DNA damage in such models. The assay, previously employed on human cells, was assessed for the first time on Mediterranean mussels (Mytilus galloprovincialis) and European eels (Anguilla anguilla), exposed to model pro-oxidant chemicals, namely benzo[a]pyrene (B[a]P) and copper. Quantification of 8-oxo-dG was microscopically carried out and expressed as relative nuclear staining intensity. Higher levels of oxidative DNA damage were detected in the digestive glands of treated mussels compared to controls, while the effect was less pronounced in haemocytes, characterized by more elevated basal levels of 8-oxo-dG. The assay was suitable for detection of 8-oxo-dG also in fish liver sections indicating consistent damage after B[a]P exposure. The main advantage of the immunohistochemical approach is the elimination of DNA extraction which considerably reduces the processing of biological samples. In addition, the assay requires small amounts of frozen tissues or fixed cells for detection of 8-oxo-dG and is potentially able to discriminate variable susceptibility to oxidative stress in different cell types. Although further investigations are required for the improvement and the validation of the assay in field conditions, laboratory exposures provided useful indications on the consistency of the approach and the efficacy of antibody 1F7 in marine organisms for a rapid assessment of pollutant-induced oxidative DNA damage

  13. Energy-filtered TEM imaging and EELS study of ODS particles and argon-filled cavities in ferritic-martensitic steels.

    Science.gov (United States)

    Klimiankou, M; Lindau, R; Möslang, A

    2005-01-01

    Oxide-dispersion-strengthened (ODS) ferritic-martensitic steels with yttrium oxide (Y(2)O(3)) have been produced by mechanical alloying and hot isostatic pressing for use as advanced material in fusion power reactors. Argon gas, usually widely used as inert gas during mechanical alloying, was surprisingly detected in the nanodispersion-strengthened materials. Energy-filtered transmission electron microscopy (EFTEM) and electron energy loss spectroscopy (EELS) led to the following results: (i) chemical composition of ODS particles, (ii) voids with typical diameters of 1-6 nm are formed in the matrix, (iii) these voids are filled with Ar gas, and (iv) the high-density nanosized ODS particles serve as trapping centers for the Ar bubbles. The Ar L(3,2) energy loss edge at 245 eV as well as the absorption features of the ODS particle elements were identified in the EELS spectrum. The energy resolution in the EEL spectrum of about 1.0 eV allows to identify the electronic structure of the ODS particles.

  14. A nose-to-nose comparison of the physiological effects of exposure to ionic silver versus silver chloride in the European eel (Anguilla anguilla) and the rainbow trout (Oncorhynchus mykiss)

    DEFF Research Database (Denmark)

    Grosell, M.; Hogstrand, C.; Wood, C.M.

    2000-01-01

    investigated during acute exposure to silver, using concentrations varying from 3 to 22 mu g silver l(-1). Silver was present either predominantly in the form of ionic silver, or in the form of silver chloride complexes (AgClaq). Inhibition of the branchial Na+,K+-ATPase enzyme activity and the active influx...

  15. Determination of some individual chlorobiphenyls in eel-fat with capillary gaschromatography: collaborative study

    NARCIS (Netherlands)

    Tuinstra, L.G.M.T.; Roos, A.H.; Werdmuller, G.A.

    1984-01-01

    A method for the determination of six individual chlorobiphenyls in eel-fat, based on saponification of the sample and determination with capillary gas chromatography, was studied collaboratively. Eleven laboratories submitted analytical results in duplo of six individual chlorbiphenyls on two

  16. Heavy Metals Uptake by Asian Swamp Eel, Monopterus albus from Paddy Fields of Kelantan, Peninsular Malaysia: Preliminary Study

    OpenAIRE

    Yin, Sow Ai; Ismail, Ahmad; Zulkifli, Syaizwan Zahmir

    2012-01-01

    Swamp eel, Monopterus albus is one of the common fish in paddy fields, thus it is suitable to be a bio-monitor for heavy metals pollution studies in paddy fields. This study was conducted to assess heavy metals levels in swamp eels collected from paddy fields in Kelantan, Malaysia. The results showed zinc [Zn (86.40 μg/g dry weight)] was the highest accumulated metal in the kidney, liver, bone, gill, muscle and skin. Among the selected organs, gill had the highest concentrations of lead (Pb),...

  17. Toxicological effect of herbicides (diuron and bentazon) on snake venom and electric eel acetylcholinesterase.

    Science.gov (United States)

    Ahmed, Mushtaq; Latif, Nadia; Khan, Rehmat Ali; Ahmad, Akhlaq

    2012-08-01

    The toxicological effects of the active ingredients of the herbicides diuron and bentazon on the activity of acetylcholinesterase (AChE) of krait (Bungarus sindanus) venom and electric eel (Electrophorus electricus) were studied. The diuron and entazon caused non-competitive inhibition of AChE from both species. For the venom AChE, the calculated IC50 for diuron and bentazon were found to be 3.25 and 0.14 μM, while for eel AChE, the respective IC50 values were 3.6 and 0.135 μM. In comparison, bentazon was a more potent inhibitor than diuron of AChE from both species. The insecticide lindane did not have any inhibitory effect on AChE activity in either species, even when tested at high concentrations (200-800 μM).

  18. XPS and EELS characterization of Mn{sub 2}SiO{sub 4}, MnSiO{sub 3} and MnAl{sub 2}O{sub 4}

    Energy Technology Data Exchange (ETDEWEB)

    Grosvenor, A.P., E-mail: andrew.grosvenor@usask.ca [Department of Chemistry, University of Saskatchewan, Saskatoon, SK S7N 5C9 (Canada); Bellhouse, E.M., E-mail: erika.bellhouse@arcelormittal.com [Global R & D—Hamilton, ArcelorMittal Dofasco, 1330 Burlington St. E, Hamilton, ON L8N 3J5 (Canada); Korinek, A., E-mail: korinek@mcmaster.ca [Canadian Centre for Electron Microscopy, Brockhouse Institute for Materials Research, McMaster University, 1280 Main St. W., Hamilton, ON L8S 4M1 (Canada); Bugnet, M., E-mail: bugnetm@mcmaster.ca [Canadian Centre for Electron Microscopy, Brockhouse Institute for Materials Research, McMaster University, 1280 Main St. W., Hamilton, ON L8S 4M1 (Canada); McDermid, J.R., E-mail: mcdermid@mcmaster.ca [Steel Research Centre, McMaster University, 1280 Main St. W., Hamilton, ON L8S 4M1 (Canada)

    2016-08-30

    Graphical abstract: XPS and EELS spectra were acquired from Mn2Al2O4, MnSiO3 and Mn2SiO4 standards and unique features identified that will allow unambiguous identification of these compounds when studying the selective oxidation of advanced steels. - Highlights: • Mn2Al2O4, MnSiO3 and Mn2SiO4 standards were synthesized and characterized using both XPS and EELS. • Unique features in both the XPS high resolution and EELS spectra were identified for all compounds. • The spectra can be used to identify these compounds when studying the selective oxidation of steels. - Abstract: X-ray Photoelectron Spectroscopy (XPS) and Electron Energy Loss Spectroscopy (EELS) are strong candidate techniques for characterizing steel surfaces and substrate-coating interfaces when investigating the selective oxidation and reactive wetting of advanced high strength steels (AHSS) during the continuous galvanizing process. However, unambiguous identification of ternary oxides such as Mn{sub 2}SiO{sub 4}, MnSiO{sub 3}, and MnAl{sub 2}O{sub 4} by XPS or EELS, which can play a significant role in substrate reactive wetting, is difficult due to the lack of fully characterized standards in the literature. To resolve this issue, samples of Mn{sub 2}SiO{sub 4}, MnSiO{sub 3} and MnAl{sub 2}O{sub 4} were synthesized and characterized by XPS and EELS. The unique features of the XPS and EELS spectra for the Mn{sub 2}SiO{sub 4}, MnSiO{sub 3} and MnAl{sub 2}O{sub 4} standards were successfully derived, thereby allowing investigators to fully differentiate and identify these oxides at the surface and subsurface of Mn, Si and Al alloyed AHSS using these techniques.

  19. Perinatal programming of depressive-like behavior by inflammation in adult offspring mice whose mothers were fed polluted eels: Gender selective effects.

    Science.gov (United States)

    Soualeh, Nidhal; Dridi, Imen; Eppe, Gauthier; Némos, Christophe; Soulimani, Rachid; Bouayed, Jaouad

    2017-07-01

    Several lines of evidence indicate that early-life inflammation may predispose to mental illness, including depression, in later-life. We investigated the impact of perinatal exposure to polluted eels on neonatal, postnatal, and adult brain inflammation, and on the resignation behavior of male and female adult offspring mice. The effects of maternal standard diet (laboratory food) were compared to the same diet enriched with low, intermediate, or highly polluted eels. Brain inflammatory markers including cytokines were assessed in offspring mice on the day of birth (i.e., on the postnatal day-PND 1), upon weaning (PND 21) and at adulthood (PND 100). Plasma myeloperoxidase and corticosterone levels were evaluated at PND 100. Immobility behavior of offspring was assessed in adulthood (i.e., at PNDs 95-100), using the tail suspension and forced swimming tests. Chronic brain inflammation was found in male and female offspring mice compared to controls, as assessed at PNDs 1, 21, and 100. The level of myeloperoxidase was found to be significantly higher in both adult males and females vs. control offspring. However, high corticosterone levels were only found in male offspring mice that were perinatally exposed to eels, suggesting a gender-selective dysregulation of the adult hypothalamic-pituitaryadrenal (HPA) axis. Gender-specific differences were also detected in adulthood in regard to offspring resignation behavior. Thus, compared to controls, males, but not females, whose mothers were fed eels during pregnancy and lactation exhibited a depressive-like behavior in adult age in both behavioral models of depression. Depressive symptoms were more pronounced in male mice perinatally exposed to either intermediate or highly polluted eels than those exposed to only lowly polluted eels. Our results indicate that early-life inflammatory insult is a plausible causative factor that induces the depressive phenotype exhibited by male adult offspring mice, most likely through a

  20. Spectrum image analysis tool - A flexible MATLAB solution to analyze EEL and CL spectrum images.

    Science.gov (United States)

    Schmidt, Franz-Philipp; Hofer, Ferdinand; Krenn, Joachim R

    2017-02-01

    Spectrum imaging techniques, gaining simultaneously structural (image) and spectroscopic data, require appropriate and careful processing to extract information of the dataset. In this article we introduce a MATLAB based software that uses three dimensional data (EEL/CL spectrum image in dm3 format (Gatan Inc.'s DigitalMicrograph ® )) as input. A graphical user interface enables a fast and easy mapping of spectral dependent images and position dependent spectra. First, data processing such as background subtraction, deconvolution and denoising, second, multiple display options including an EEL/CL moviemaker and, third, the applicability on a large amount of data sets with a small work load makes this program an interesting tool to visualize otherwise hidden details. Copyright © 2016 Elsevier Ltd. All rights reserved.

  1. An electric-eel-inspired soft power source from stacked hydrogels

    Science.gov (United States)

    Schroeder, Thomas B. H.; Guha, Anirvan; Lamoureux, Aaron; Vanrenterghem, Gloria; Sept, David; Shtein, Max; Yang, Jerry; Mayer, Michael

    2017-12-01

    Progress towards the integration of technology into living organisms requires electrical power sources that are biocompatible, mechanically flexible, and able to harness the chemical energy available inside biological systems. Conventional batteries were not designed with these criteria in mind. The electric organ of the knifefish Electrophorus electricus (commonly known as the electric eel) is, however, an example of an electrical power source that operates within biological constraints while featuring power characteristics that include peak potential differences of 600 volts and currents of 1 ampere. Here we introduce an electric-eel-inspired power concept that uses gradients of ions between miniature polyacrylamide hydrogel compartments bounded by a repeating sequence of cation- and anion-selective hydrogel membranes. The system uses a scalable stacking or folding geometry that generates 110 volts at open circuit or 27 milliwatts per square metre per gel cell upon simultaneous, self-registered mechanical contact activation of thousands of gel compartments in series while circumventing power dissipation before contact. Unlike typical batteries, these systems are soft, flexible, transparent, and potentially biocompatible. These characteristics suggest that artificial electric organs could be used to power next-generation implant materials such as pacemakers, implantable sensors, or prosthetic devices in hybrids of living and non-living systems.

  2. An electric-eel-inspired soft power source from stacked hydrogels.

    Science.gov (United States)

    Schroeder, Thomas B H; Guha, Anirvan; Lamoureux, Aaron; VanRenterghem, Gloria; Sept, David; Shtein, Max; Yang, Jerry; Mayer, Michael

    2017-12-13

    Progress towards the integration of technology into living organisms requires electrical power sources that are biocompatible, mechanically flexible, and able to harness the chemical energy available inside biological systems. Conventional batteries were not designed with these criteria in mind. The electric organ of the knifefish Electrophorus electricus (commonly known as the electric eel) is, however, an example of an electrical power source that operates within biological constraints while featuring power characteristics that include peak potential differences of 600 volts and currents of 1 ampere. Here we introduce an electric-eel-inspired power concept that uses gradients of ions between miniature polyacrylamide hydrogel compartments bounded by a repeating sequence of cation- and anion-selective hydrogel membranes. The system uses a scalable stacking or folding geometry that generates 110 volts at open circuit or 27 milliwatts per square metre per gel cell upon simultaneous, self-registered mechanical contact activation of thousands of gel compartments in series while circumventing power dissipation before contact. Unlike typical batteries, these systems are soft, flexible, transparent, and potentially biocompatible. These characteristics suggest that artificial electric organs could be used to power next-generation implant materials such as pacemakers, implantable sensors, or prosthetic devices in hybrids of living and non-living systems.

  3. Poliitkommunikatsioon kohalike valimiste eel / Liisa Past, Tarvo Sarmet, Taavi Pukk ... [jt.] ; intervjueerinud Küllike Heide

    Index Scriptorium Estoniae

    2013-01-01

    Lähenevate kohalike valimiste eel poliitilise kommunikatsioonitegevuse korraldusest praegustes parlamendierakondades. Mõtteid jagavad Liisa Past ja Tarvo Sarmet Sotsiaaldemokraatlikust Erakonnast, Taavi Pukk Keskerakonnast, Gerrit Mäesalu IRL-st ning Silver Pukk Reformierakonnast

  4. Genetic analysis of rock hole and domestic Aedes aegypti on the Caribbean island of Anguilla.

    Science.gov (United States)

    Wallis, G P; Tabachnick, W J

    1990-12-01

    Genetic variation was characterized at 11 enzyme coding loci in Aedes aegypti collected from 3 rock hole and 4 domestic sites on the island of Anguilla, West Indies. The pattern of gene frequency variation suggests that these mosquito samples do not constitute a single panmictic population, but there are no large consistent differences between rock hole and domestic forms to parallel the East African sylvan-domestic dichotomy. With the exception of one of the domestic populations, two loci did however show some gene frequency differences consistent with genetic differentiation between the 2 habitat types. We conclude that whereas there may be some degree of differentiation between the 2 habitat types, local eradication attempts and sporadic gene flow cause temporal and spatial volatility that is sufficient to swamp these differences.

  5. Convergent evolution of jaws between spinosaurid dinosaurs and pike conger eels

    Directory of Open Access Journals (Sweden)

    Romain Vullo

    2016-12-01

    Full Text Available Spinosaurs represent a group of peculiar theropod dinosaurs that have often been described as “crocodile-mimic”, predominantly fish-eating predators, and recently claimed to have been semi-aquatic animals. Here we report a suite of craniodental characters unexpectedly shared by spinosaurs and pike conger eels. Pike conger eels are predatory, mainly piscivorous bottom-dwelling anguilliform fishes that inhabit marine and brackish environments. These two groups of dinosaurs and fishes show a mediolaterally compressed, elongated rostrum, a terminal “rosette” bearing enlarged teeth in both upper and lower jaws, and a notch posterior to the premaxillary “rosette” characterized by the presence of reduced teeth. The morphological convergence observed in the jaws of these two distantly related groups of vertebrates may result from similar feeding behaviours. This typical jaw morphology likely represents an effective biomechanical adaptation for biting and grabbing elusive prey items in low-light aquatic environments. Associated with this specialized snout morphology, numerous integumentary mechanoreceptors involved in prey detection are present in both spinosaurs and pike congers. Our new observations provide an additional convincing argument regarding the decades-long and widely debated lifestyle of spinosaurs.

  6. Evolutionary dynamics and genetic diversity from three genes of Anguillid rhabdovirus

    DEFF Research Database (Denmark)

    Bellec, Laure; Cabon, Joelle; Bergmann, Sven

    2014-01-01

    Wild freshwater eel populations have dramatically declined in recent past decades in Europe and America, partially through the impact of several factors including the wide spread of infectious diseases. The anguillid rhabdoviruses eel virus European X (EVEX) and eel virus American (EVA) potential...

  7. Functional characterisation of eel dopamine D2 receptors and involvement in the direct inhibition of pituitary gonadotrophins

    DEFF Research Database (Denmark)

    Jolly, C.; Rousseau, K.; Prézeau, L.

    2016-01-01

    and antagonists, supporting subtle structure/activity differences. Furthermore, using eel pituitary cell primary cultures, the expression by gonadotroph cells of both native eel D2‐R paralogues was examined by in situ hybridisation of D2A‐R or D2B‐R transcripts, coupled with immunofluorescence of luteinising...... hormone (LH)β or follicle‐stimulating (FSH)β. LH and to a lesser extent, FSH cells expressed both D2‐R transcripts but with a clear predominance of D2B‐R. Notably, D2B‐R transcripts were detected for the majority of LH cells. Accordingly, using these cultures, we showed that DA potently inhibited basal...

  8. Prevalence and intensity of third stage Gnathostoma spinigerum larvae in swamp eels sold in three large markets in Bangkok, Thailand.

    Science.gov (United States)

    Saksirisampant, Wilai; Nuchprayoon, Surang; Wiwanitkit, Viroj; Kraivichian, Kanyarat; Suwansaksri, Jamsai

    2002-01-01

    Gnathostoma spinigerum is a common human tissue parasite in Thailand. The swamp eel is the major intermediate or paratenic host for this parasite. The high prevalence of the infective third stage larvae (L3) of this parasite in the rainy season has been noted in previous studies. During June 1999 (rainy season), we performed a cross-sectional survey of the prevalence and the intensity of G. spinigerum L3s in the livers of swamp eels that were obtained from three large Bangkok markets (Klong Toey, Pran Nok, and Tevej). Of a total of 785 livers, G. spinigerum L3s were found in 97: an infection rate of 12%. The prevalence rates in Klong Toey, Pran Nok, and Tevej markets were 13%, 10% and 14% respectively. There was no significant difference in the proportion of infected eels between the markets (p > 0.05). The intensity of L3 burden in the livers ranged from 1-17 larvae, with an average of 2.60 +/- 0.24 larvae (mean +/- SE). In this study a high prevalence of G. spinigerum L3s was found; there was no significant difference in the intensity of larvae in swamp eels between markets. These findings emphasize the importance of public health education: people need to be aware of the dangers of consuming raw or undercooked food.

  9. The Eel River, northwestern California; high sediment yields from a dynamic landscape

    Science.gov (United States)

    Thomas E. Lisle

    1990-01-01

    The Eel River draining the Coast Range of northwestern California has the highest recorded average suspended sediment yield per drainage area of any river of its size or larger unaffected by volcanic eruptions or active glaciers in the conterminous United States (1,720 t/km 2 yr from 9,390 km 2 ; Brown and Ritter, 1971).

  10. How the body contributes to the wake in undulatory fish swimming: Flow fields of a swimming eel (Anguilla anguilla)

    NARCIS (Netherlands)

    Müller, Ulrike K.; Smit, Joris; Stamhuis, Eize J.; Videler, John J.

    2001-01-01

    Undulatory swimmers generate thrust by passing a transverse wave down their body. Thrust is generated not just at the tail, but also to a varying degree by the body, depending on the fish's morphology and swimming movements. To examine the mechanisms by which the body in particular contributes to

  11. Tracking anguillid eels: five decades of telemetry-based research

    DEFF Research Database (Denmark)

    Beguer-Pon, Melanie; Dodson, Julian J.; Castonguay, Martin

    2018-01-01

    anguillid species have been tracked in three main geographical locations: Western Europe, the north-eastern part of North America and Australasia. Telemetry has proven to be an effective method for determining patterns of yellow eel movements in continental waters. It has also been used extensively...... satellite tags have provided indications of spawning areas, extensive vertical migrations and initial clues about the orientation mechanisms at sea. Telemetry studies have also revealed apparent evidence of predation by marine mammals and fish at sea, suggesting a significant natural source of mortality...

  12. Experimental hydrodynamics of swimming in fishes

    Science.gov (United States)

    Tytell, Eric Daniel

    2005-11-01

    The great diversity of fish body shapes suggests that they have adapted to different selective pressures. For many fishes, the pressures include hydrodynamic demands: swimming efficiently or accelerating rapidly, for instance. However, the hydrodynamic advantages or disadvantages to specific morphologies are poorly understood. In particular, eels have been considered inefficient swimmers, but they migrate long distances without feeding, a task that requires efficient swimming. This dissertation, therefore, begins with an examination of the swimming hydrodynamics of American eels, Anguilla rostrata, at steady swimming speeds from 0.5 to 2 body lengths (L) per second and during accelerations from -1.4 to 1.3 L s -2. The final chapter examines the hydrodynamic effects of body shape directly by describing three-dimensional flow around swimming bluegill sunfish, Lepomis macrochirus. In all chapters, flow is quantified using digital particle image velocimetry, and simultaneous kinematics are measured from high-resolution digital video. The wake behind a swimming eel in the horizontal midline plane is described first. Rather than producing a wake with fluid jets angled backwards, like in fishes such as sunfish, eels have a wake with exclusively lateral jets. The lack of downstream momentum indicates that eels balance the axial forces of thrust and drag evenly over time and over their bodies, and therefore do not change axial fluid momentum. This even balance, present at all steady swimming speeds, is probably due to the relatively uniform body shape of eels. As eels accelerate, thrust exceeds drag, axial momentum increases, and the wake approaches that of other fishes. During steady swimming, though, the lack of axial momentum prevents direct efficiency estimation. The effect of body shape was examined directly by measuring flow in multiple transverse planes along the body of bluegill sunfish swimming at 1.2 L s-1. The dorsal and anal fin, neglected in many previous

  13. Sparse modeling of EELS and EDX spectral imaging data by nonnegative matrix factorization

    Energy Technology Data Exchange (ETDEWEB)

    Shiga, Motoki, E-mail: shiga_m@gifu-u.ac.jp [Department of Electrical, Electronic and Computer Engineering, Gifu University, 1-1, Yanagido, Gifu 501-1193 (Japan); Tatsumi, Kazuyoshi; Muto, Shunsuke [Advanced Measurement Technology Center, Institute of Materials and Systems for Sustainability, Nagoya University, Chikusa-ku, Nagoya 464-8603 (Japan); Tsuda, Koji [Graduate School of Frontier Sciences, University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa 277-8561 (Japan); Center for Materials Research by Information Integration, National Institute for Materials Science, 1-2-1 Sengen, Tsukuba 305-0047 (Japan); Biotechnology Research Institute for Drug Discovery, National Institute of Advanced Industrial Science and Technology, 2-4-7 Aomi Koto-ku, Tokyo 135-0064 (Japan); Yamamoto, Yuta [High-Voltage Electron Microscope Laboratory, Institute of Materials and Systems for Sustainability, Nagoya University, Chikusa-ku, Nagoya 464-8603 (Japan); Mori, Toshiyuki [Environment and Energy Materials Division, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044 (Japan); Tanji, Takayoshi [Division of Materials Research, Institute of Materials and Systems for Sustainability, Nagoya University, Chikusa-ku, Nagoya 464-8603 (Japan)

    2016-11-15

    Advances in scanning transmission electron microscopy (STEM) techniques have enabled us to automatically obtain electron energy-loss (EELS)/energy-dispersive X-ray (EDX) spectral datasets from a specified region of interest (ROI) at an arbitrary step width, called spectral imaging (SI). Instead of manually identifying the potential constituent chemical components from the ROI and determining the chemical state of each spectral component from the SI data stored in a huge three-dimensional matrix, it is more effective and efficient to use a statistical approach for the automatic resolution and extraction of the underlying chemical components. Among many different statistical approaches, we adopt a non-negative matrix factorization (NMF) technique, mainly because of the natural assumption of non-negative values in the spectra and cardinalities of chemical components, which are always positive in actual data. This paper proposes a new NMF model with two penalty terms: (i) an automatic relevance determination (ARD) prior, which optimizes the number of components, and (ii) a soft orthogonal constraint, which clearly resolves each spectrum component. For the factorization, we further propose a fast optimization algorithm based on hierarchical alternating least-squares. Numerical experiments using both phantom and real STEM-EDX/EELS SI datasets demonstrate that the ARD prior successfully identifies the correct number of physically meaningful components. The soft orthogonal constraint is also shown to be effective, particularly for STEM-EELS SI data, where neither the spatial nor spectral entries in the matrices are sparse. - Highlights: • Automatic resolution of chemical components from spectral imaging is considered. • We propose a new non-negative matrix factorization with two new penalties. • The first penalty is sparseness to choose the number of components from data. • Experimental results with real data demonstrate effectiveness of our method.

  14. Imaging Si nanoparticles embedded in SiO2 layers by (S)TEM-EELS

    International Nuclear Information System (INIS)

    Schamm, S.; Bonafos, C.; Coffin, H.; Cherkashin, N.; Carrada, M.; Ben Assayag, G.; Claverie, A.; Tence, M.; Colliex, C.

    2008-01-01

    Fabrication of systems in which Si nanoparticles are embedded in a thin silica layer is today mature for non-volatile memory and opto-electronics applications. The control of the different parameters (position, size and density) of the nanoparticles population is a key point to optimize the properties of such systems. A review of dedicated transmission electron microscopy (TEM) methods, which can be used to measure these parameters, is presented with an emphasis on those relying on electron energy-loss spectroscopy (EELS). Defocused bright-field imaging can be used in order to determine topographic information of a whole assembly of nanoparticles, but it is not efficient for looking at individual nanoparticles. High-resolution electron imaging or dark-field imaging can be of help in the case of crystalline particles but they always provide underestimated values of the nanocrystals population. EELS imaging in the low-energy-loss domain around the Si plasmon peak, which gives rise to strong signals, is the only way to visualize all Si nanoparticles within a silica film and to perform reliable size and density measurements. Two complementary types of experiments are investigated and discussed more extensively: direct imaging with a transmission electron microscope equipped with an imaging filter (EFTEM) and indirect imaging from spectrum-imaging data acquired with a scanning transmission electron microscope equipped with a spectrometer (STEM-PEELS). The direct image (EFTEM) and indirect set of spectra (STEM-PEELS) are processed in order to deliver images where the contribution of the silica matrix is minimized. The contrast of the resulting images can be enhanced with adapted numerical filters for further morphometric analysis. The two methods give equivalent results, with an easier access for EFTEM and the possibility of a more detailed study of the EELS signatures in the case of STEM-PEELS. Irradiation damage in such systems is also discussed

  15. Flood inundation maps for the Wabash and Eel Rivers at Logansport, Indiana

    Science.gov (United States)

    Fowler, Kathleen K.

    2014-01-01

    Digital flood-inundation maps for an 8.3-mile reach of the Wabash River and a 7.6-mile reach of the Eel River at Logansport, Indiana (Ind.), were created by the U.S. Geological Survey (USGS) in cooperation with the Indiana Office of Community and Rural Affairs. The inundation maps, which can be accessed through the USGS Flood Inundation Mapping Science Web site at http://water.usgs.gov/osw/flood_inundation/, depict estimates of the areal extent and depth of flooding corresponding to selected water levels (stages) at USGS streamgage Wabash River at Logansport, Ind. (sta. no. 03329000) and USGS streamgage Eel River near Logansport, Ind. (sta. no. 03328500). Current conditions for estimating near-real-time areas of inundation using USGS streamgage information may be obtained on the Internet at http://waterdata.usgs.gov/. In addition, information has been provided to the National Weather Service (NWS) for incorporation into their Advanced Hydrologic Prediction Service (AHPS) flood warning system http:/water.weather.gov/ahps/). The NWS forecasts flood hydrographs at many places that are often colocated with USGS streamgages. NWS-forecasted peak-stage information may be used in conjunction with the maps developed in this study to show predicted areas of flood inundation. For this study, flood profiles were computed for the stream reaches by means of a one-dimensional step-backwater model developed by the U.S. Army Corps of Engineers. The hydraulic model was calibrated by using the most current stage-discharge relations at USGS streamgages 03329000, Wabash River at Logansport, Ind., and 03328500, Eel River near Logansport, Ind. The calibrated hydraulic model was then used to determine five water-surface profiles for flood stage at 1-foot intervals referenced to the Wabash River streamgage datum, and four water-surface profiles for flood stages at 1-foot intervals referenced to the Eel River streamgage datum. The stages range from bankfull to approximately the highest

  16. Three nuclear and two membrane estrogen receptors in basal teleosts, Anguilla sp.: Identification, evolutionary history and differential expression regulation

    DEFF Research Database (Denmark)

    Lafont, Anne Gaëlle; Rousseau, Karine; Tomkiewicz, Jonna

    2016-01-01

    Estrogens interact with classical intracellular nuclear receptors (ESR), and with G-coupled membrane receptors (GPER). In the eel, we identified three nuclear (ESR1, ESR2a, ESR2b) and two membrane (GPERa, GPERb) estrogen receptors. Duplicated ESR2 and GPER were also retrieved in most extant teleo...

  17. Accurate measurement of absolute experimental inelastic mean free paths and EELS differential cross-sections

    Energy Technology Data Exchange (ETDEWEB)

    Craven, Alan J.; Bobynko, Joanna; Sala, Bianca; MacLaren, Ian, E-mail: ian.maclaren@glasgow.ac.uk

    2016-11-15

    Methods are described for measuring accurate absolute experimental inelastic mean free paths and differential cross-sections using DualEELS. The methods remove the effects of surface layers and give the results for the bulk materials. The materials used are VC{sub 0.83}, TiC{sub 0.98}, VN{sub 0.97} and TiN{sub 0.88} but the method should be applicable to a wide range of materials. The data was taken at 200 keV using a probe half angle of 29 mrad and a collection angle of 36 mrad. The background can be subtracted from under the ionisation edges, which can then be separated from each other. This is achieved by scaling Hartree-Slater calculated cross-sections to the edges in the atomic regions well above the threshold. The average scaling factors required are 1.00 for the non-metal K-edges and 1.01 for the metal L-edges (with uncertainties of a few percent). If preliminary measurements of the chromatic effects in the post-specimen lenses are correct, both drop to 0.99. The inelastic mean free path for TiC{sub 0.98} was measured as 103.6±0.5 nm compared to the prediction of 126.9 nm based on the widely used Iakoubovskii parameterisation. - Highlights: • We show how to extract absolute cross sections for EELS edges using DualEELS. • The method removes the effects of any surface layers on standards. • We use a needle specimen to determining the mean free path for inelastic scattering. • Constrained background fitting is essential to correct background subtraction. • Absolute cross sections are determined for TiC, TiN, VC and VN.

  18. A multi-locus molecular timescale for the origin and diversification of eels (Order: Anguilliformes).

    Science.gov (United States)

    Santini, Francesco; Kong, Xianghui; Sorenson, Laurie; Carnevale, Giorgio; Mehta, Rita S; Alfaro, Michael E

    2013-12-01

    Anguilliformes are an ecologically diverse group of predominantly marine fishes whose members are easily recognized by their extremely elongate bodies, and universal lack of pelvic fins. Recent studies based on mitochondrial loci, including full mitogenomes, have called into question the monophyly of both the Anguilliformes, which appear to be paraphyletic without the inclusion of the Saccopharyngiformes (gulper eels and allies), as well as other more commonly known eel families (e.g., Congridae, Serrivomeridae). However, no study to date has investigated anguilliform interrelationships using nuclear loci. Here we present a new phylogenetic hypothesis for the Anguilliformes based on five markers (the nuclear loci Early Growth Hormone 3, Myosin Heavy Polypeptide 6 and Recombinase Activating Gene 1, as well as the mitochondrial genes Cytochrome b and Cytochrome Oxidase I). Our sampling spans 148 species and includes 19 of the 20 extant families of anguilliforms and saccopharyngiforms. Maximum likelihood analysis reveals that saccopharyngiform eels are deeply nested within the anguilliforms, and supports the non-monophyly of Congridae and Nettastomatidae, as well as that of Derichthyidae and Chlopsidae. Our analyses suggest that Protanguilla may be the sister group of the Synaphobranchidae, though the recent hypothesis that this species is the sister group to all other anguilliforms cannot be rejected. The molecular phylogeny, time-calibrated using a Bayesian relaxed clock approach and seven fossil calibration points, reveals a Late Cretaceous origin of this expanded anguilliform clade (stem age ~116 Ma, crown age ~99 Ma). Most major (family level) lineages originated between the end of the Cretaceous and Early Eocene, suggesting that anguilliform radiation may have been facilitated by the recovery of marine ecosystems following the KP extinction. Copyright © 2013 Elsevier Inc. All rights reserved.

  19. Biological recipient control at the Oskarshamn nuclear power plant. Annual report for 2011

    International Nuclear Information System (INIS)

    Andersson, Jan; Franzen, Fredrik; Lingman, Anna

    2012-01-01

    (Anguilla anguilla) did not change over time in the recipient since the 1980s. The prevalence of swim bladder parasites (Anguillicoloides sp.) has been 50-60% since the parasite was established in Hamnefjaerden in the late 1980's. Gillnet surveys are performed in the spring on the open coast at the power plant to study effects on Baltic herring and other marine species, normally appearing at low water temperatures. Problems due to an increasing population of grey seals forced a change in fishing methodology in 2011, and the pelagic nets were replaced with a series of demersal nets. The abundances of the long term dominants Baltic herring (Clupea harengus), sea scorpions (Myoxocephalus scorpius) and cod (Gadus morhua) have shown large periodic variations since the survey was established in the early 1970's. Cod alone has shown a long term decrease, probably reflecting the general situation in the Baltic Sea. Silver eel (Anguilla anguilla) catches decreased in the local fishery, but increased in the reference area until silver eel fishing stopped in this area in 2001. The long term development is however believed to reflect the general trends of eel in the Baltic region. Abundance and species richness in soft bottom macro fauna increased strongly in shallow sites between 1962-2011, in Simpevarp as well as in the reference area. The number of species increased also on deeper sites, but the total abundance did not change significantly. The abundance of the introduced polychaete Marenzelleria sp. increased rapidly in recent years and is now among the dominants in both areas. The trend is reflective of the general changes in the Baltic Sea. Vegetation on hard bottoms is monitored on three sites in the coastal gradient of cooling water. The algal communities are considered to have good ecological status and the studied sites are among the richest in the region. The Fucus vesiculosus cover decreased however, in recent years due to the wearing of ice. Fucus increased its

  20. Biological recipient control at the Oskarshamn nuclear power plant. Annual report for 2011; Biologisk recipientkontroll vid Oskarshamns kaernkraftverk. Aarsrapport foer 2011

    Energy Technology Data Exchange (ETDEWEB)

    Andersson, Jan; Franzen, Fredrik; Lingman, Anna

    2012-07-01

    (Anguilla anguilla) did not change over time in the recipient since the 1980s. The prevalence of swim bladder parasites (Anguillicoloides sp.) has been 50-60% since the parasite was established in Hamnefjaerden in the late 1980's. Gillnet surveys are performed in the spring on the open coast at the power plant to study effects on Baltic herring and other marine species, normally appearing at low water temperatures. Problems due to an increasing population of grey seals forced a change in fishing methodology in 2011, and the pelagic nets were replaced with a series of demersal nets. The abundances of the long term dominants Baltic herring (Clupea harengus), sea scorpions (Myoxocephalus scorpius) and cod (Gadus morhua) have shown large periodic variations since the survey was established in the early 1970's. Cod alone has shown a long term decrease, probably reflecting the general situation in the Baltic Sea. Silver eel (Anguilla anguilla) catches decreased in the local fishery, but increased in the reference area until silver eel fishing stopped in this area in 2001. The long term development is however believed to reflect the general trends of eel in the Baltic region. Abundance and species richness in soft bottom macro fauna increased strongly in shallow sites between 1962-2011, in Simpevarp as well as in the reference area. The number of species increased also on deeper sites, but the total abundance did not change significantly. The abundance of the introduced polychaete Marenzelleria sp. increased rapidly in recent years and is now among the dominants in both areas. The trend is reflective of the general changes in the Baltic Sea. Vegetation on hard bottoms is monitored on three sites in the coastal gradient of cooling water. The algal communities are considered to have good ecological status and the studied sites are among the richest in the region. The Fucus vesiculosus cover decreased however, in recent years due to the wearing of ice. Fucus increased its

  1. Molecular and functional expression of high conductance Ca 2+ activated K+ channels in the eel intestinal epithelium

    DEFF Research Database (Denmark)

    Lionetto, Maria G; Rizzello, Antonia; Giordano, Maria E

    2008-01-01

    Several types of K(+) channels have been identified in epithelial cells. Among them high conductance Ca(2+)-activated K(+) channels (BK channels) are of relevant importance for their involvement in regulatory volume decrease (RVD) response following hypotonic stress. The aim of the present work...... was to investigate the functional and molecular expression of BK in the eel intestine, which is a useful experimental model for cell volume regulation research. In the present paper using rat BK channel-specific primer, a RT-PCR signal of 696 pb cDNA was detected in eel intestine, whole nucleotide sequence showed...... high similarity (83%) to the alpha subunit of BK channel family. BK channel protein expression was verified by immunoblotting and confocal microscopy, while the functional role of BK channels in epithelial ion transport mechanisms and cell volume regulation was examined by electrophysiological...

  2. Roles of the cytoskeleton and of Protein Phosphorylation Events in the Osmotic Stress Response in EEL Intestinal Epithelium

    DEFF Research Database (Denmark)

    Lionetto, Maria G; Pedersen, Stine F; Hoffmann, Else K

    2002-01-01

    The eel intestinal epithelium responds to an acute hypertonic challenge by a biphasic increase of the rate of Cl(-) absorption (measured as short circuit current, Isc, and creating a negative transepithelial potential, V(te), at the basolateral side of the epithelium). While the first, transient...... phase is bumetanide-insensitive, the second, sustained phase is bumetanide-sensitive, reflecting activation of the apically located Na(+)-K(+)-2Cl(-) (NKCC) cotransporter, which correlates with the cellular RVI response. Here, we investigated the involvement of the cytoskeleton and of serine....../threonine phosphorylation events in the osmotic stress-induced ion transport in the eel intestinal epithelium, focusing on the sustained RVI phase, as well as on the previously uncharacterized response to hypotonic stress. The study was carried out using confocal laser scanning microscopy, a quantitative F-actin assay...

  3. Accumulation of metals, polycyclic (halogenated) aromatic hydrocarbons, and biocides in zebra mussel and eel from the Rhine and Meuse rivers

    Energy Technology Data Exchange (ETDEWEB)

    Hendriks, A.J. [RIZA, Lelystad (Netherlands). Inst. for Inland Water Management and Waste Water Treatment; Pieters, H.; Boer, J. de [DLO-Netherlands Inst. for Fisheries Research, IJmuiden (Netherlands)

    1998-10-01

    Concentrations of heavy metals and various groups of organic microcontaminants were measured in zebra mussel and eel from the Rhine-Meuse basin. Residues in mussel from the Rhine and Meuse were on average 2.3 and 2.9 times higher than in those from the reference location of IJsselmeer. Total body burdens of organic microcontaminants in mussel and eel varied between 0.05 to 0.07 mmol/kg fat weight in six out of seven samples. The largest contribution in mussels and eel came from polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs), respectively. Concentrations of bromodiphenyl-ethers, chlorobenzenes, chloronitrobenzenes, chloroterphenyls, and chlorobenzyltoluenes were lower. Total polybrominated biphenyl residues appear lower than total PCB levels. The largest chlorobiocide residues were noted for 4,4{prime}-DDE, toxaphene, trichlorophenylmethane, and {gamma}-hexachlorocyclohexane. An extraordinary high body burden of 1.2 mmol/kg fat weight, largely consisting of acenaphthene, was observed in one sample. Ratios of concentrations in organism fat and dry organic suspended solids varied between 1 and 10 for traditionally monitored organochlorines, independent of the octanol-water partition coefficient. The values did not deviate significantly from a value of about 3.3, expected for equilibrium partitioning of persistent chemicals. Lower values were observed for PAHs and some chloro(nitro)benzenes. Most ratios of concentrations in eel and mussel fat were within the range of 1 to 10, also largely independent of K{sub ow}. Yet, values tended to be higher at K{sub ow} > 10{sup 6}. Ratios below 1 were noted for pentabromodiphenylether, pentachloro(thio)anisol, chlorobenzyltoluenes, and some chloronitrobenzenes, chlorobiphenyls, and chlorobiocides. These field data confirm recent modeling efforts on bioconcentration and biomagnification. For heavy metals, atomic mass explained 67% of the variation in zebra mussel residues.

  4. Collective modes in CuxTiSe2 measured with meV-resolution EELS

    Science.gov (United States)

    Rak, Melinda; Vig, Sean; Husain, Ali; Mitrano, Matteo; Rubeck, Samantha; Kogar, Anshul; Karapetrov, Goran; Morosan, Emilia; Abbamonte, Peter

    The charge density wave (CDW) in 1 T-TiSe2 has been widely thought to be the result of an excitonic insulator transition. We recently observed a soft electronic mode in TiSe2 using a new, momentum-resolved electron energy loss spectroscopy (M-EELS) technique, demonstrating a condensation of electron-hole pairs in this material. As TiSe2 is doped with Cu to produce CuxTiSe2, a superconducting dome emerges above x ˜ 0.04. In this talk, I describe how the electronic collective mode evolves with Cu doping. We find that the temperature dependence of the electronic mode reverses as Cu is introduced and that the mode is much broader at low temperature as compared to the undoped material. Additionally, the electronic mode no longer has a positive dispersion at 300 K as described by the Lindhard function, but has a slightly negative dispersion for small momentum transfers. We will discuss the implications of these results for the excitonic insulator transition in TiSe2. This work was supported by the Gordon and Betty Moore Foundation's EPiQS Initiative through Grant GBMF4542. An early prototype of the M-EELS instrument was supported by the DOE Center for Emergent Superconductivity under Award No. DE-AC02-98CH10886.

  5. TEM and EELS studies of microwave-irradiation synthesis of bimetallic platinum nanocatalysts

    International Nuclear Information System (INIS)

    Mathe, N R; Scriba, M R; Coville, N J; Olivier, J E

    2014-01-01

    Microwave-irradiation (MW) synthesis of nanostructured materials provides for the synthesis of metal nanoparticles, using fast and uniform heating rates. This procedure affords better control of the shape and size of the nanoparticles when compared to conventional methods. In this work, microwave-irradiation was used to produce platinum-cobalt (Pt-Co) and platinum-nickel (Pt-Ni) nanoparticles for use as electrocatalysts in the methanol oxidation reaction. High resolution TEM imaging and EELS studies revealed that these bimetallic nanoparticles form islands or hetero-structures

  6. Study by AES, EELS Spectroscopy of electron Irradiation on InP and InPO4/InP in comparison with Monte Carlo simulation

    International Nuclear Information System (INIS)

    Lounis, Z; Bouslama, M; Hamaida, K; Abdellaoui, A; Ouerdane, A; Ghaffour, M; Berrouachedi, N; Jardin, C

    2012-01-01

    We give the great interest to characterise the InP and InPO 4 /InP submitted to electron beam irradiation owing to the Auger Electron Spectroscopy (AES) associated to both methods Electron Energy Loss Spectroscopy (EELS). The incident electron produces breaking of (In-P) chemical bonds. The electron beam even acts to stimulate oxidation of InP surface involving on the top layers. Other, the oxide InPO 4 developed on InP does appear very sensitive to the irradiation due to electron beam shown by the monitoring of EELS spectra recorded versus the irradiated times of the surface. There appears a new oxide thought to be In 2 O 3 . We give the simulation methods Casino (Carlo simulation of electron trajectory in solids) for determination with accuracy the loss energy of backscattered electrons and compared with reports results have been obtained with EELS Spectroscopy. These techniques of spectroscopy alone do not be able to verify the affected depth during interaction process. So, using this simulation method, we determine the interaction of electrons in the matter.

  7. Intracellular pH regulation in hepatocytes isolated from three teleost species.

    Science.gov (United States)

    Furimsky, M; Moon, T W; Perry, S F

    1999-09-01

    The mechanisms of intracellular pH (pH(i)) regulation were studied in hepatocytes isolated from three species of teleost: rainbow trout (Oncorhynchus mykiss), black bullhead (Ameiurus melas) and American eel (Anguilla rostrata). Intracellular pH was monitored over time using the pH-sensitive fluorescent dye BCECF in response to acid loading under control conditions and in different experimental media containing either low Na(+) or Cl(-) concentrations, the Na(+)-H(+) exchanger blocker amiloride or the blocker of the V-type H(+)-ATPase, bafilomycin A(1). In trout and bullhead hepatocytes, recovery to an intracellular acid load occurred principally by way of a Na(+)-dependent amiloride-sensitive Na(+)-H(+) exchanger. In eel hepatocytes, the Na(+)-H(+) exchanger did not contribute to recovery to an acid load though evidence suggests that it is present on the cell membrane and participates in the maintenance of steady-state pH(i). The V-type H(+)-ATPase did not participate in recovery to an acid load in any species. A Cl(-)-HCO(3)(-) exchanger may play a role in recovery to an acid load in eel hepatocytes by switching off and retaining base that would normally be tonically extruded. Thus, it is clear that hepatocytes isolated from the three species are capable of regulating pH(i), principally by way of a Na(+)-H(+) exchanger and a Cl(-)-HCO(3)(-) exchanger, but do not exploit identical mechanisms for pH(i) recovery. J. Exp. Zool. 284:361-367, 1999. Copyright 1999 Wiley-Liss, Inc.

  8. Utilising DualEELS to probe the nanoscale mechanisms of the corrosion of Zircaloy-4 in 350 °C pressurised water

    Energy Technology Data Exchange (ETDEWEB)

    Annand, Kirsty J., E-mail: k.annand.1@research.gla.ac.uk [Materials and Condensed Matter Physics, School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ (United Kingdom); MacLaren, Ian [Materials and Condensed Matter Physics, School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ (United Kingdom); Gass, Mhairi [AMEC Foster Wheeler, Clean Energy, Walton House, Birchwood Park, WA3 6GA (United Kingdom)

    2015-10-15

    Characterisation of materials utilised for fuel cladding in nuclear reactors prior to service is integral in order to understand corrosion mechanisms which would take place in reactor. Zircaloy-4 is one such material of choice for nuclear fuel containment in Pressurised Water Reactors (PWRs). In particular, the metal-oxide interface has been a predominant focus of previous research, however, due to the complex oxidation process of zirconium cladding, there is still no clear understanding of what is present at the interface. Using Scanning Transmission Electron Microscopy (STEM) and Dual Electron Energy Loss Spectroscopy (DualEELS), we have studied the corrosion of this material under conditions similar to those that could be encountered in service. It is shown that under all conditions, whether during faster oxidation in the early stages, slow growth just prior to the transition to a new growth regime, or in the faster growth that happens after this transition, the surface of the metal below the scale is loaded with oxygen up to around 33 at%. Approaching transition, in conditions of slow growth and slow oxygen supply, an additional metastable suboxide is apparent with a thickness of tens of nm. By studying changes in both chemical composition and dielectric function of the material at the oxide scale – metal interface with nanometre resolution, quantitative mapping could be achieved, clearly showing that this is a suboxide composition of ZrO and a Zr oxidation state close to +2. - Highlights: • Metal-oxide interface evolution studied by few-nm resolution EELS mapping. • Low loss EELS is very effective for mapping phase evolution. • ZrO suboxide phase characterised using EELS, which fits theoretical predictions. • ZrO formation found to correlate to local growth rate of oxide scale.

  9. Effects of a chemical plant on surface water, illustrated by the example of the chemical plant at Berlin-Adlershof/Gruenau. Vol.3 in the series: Site profiles of persistent chlorinated hydrocarbons - cause-oriented monitoring in aquatic media; Auswirkungen eines Chemiestandortes auf umliegende Gewaesser dargestellt am Beispiel der chemischen Fabrik in Berlin-Adlershof/Gruenau. Bd. 3 der Reihe: Standortprofile persistenter chlorierter Kohlenwasserstoffe - ursachenorientiertes Monitoring in aquatischen Medien

    Energy Technology Data Exchange (ETDEWEB)

    Heinisch, E.; Kettrup, A.; Bergheim, W.; Wenzel, S.

    2002-06-01

    Primary data which were obtained on the basis of official surveys by the Senatsverwaltung fuer Stadtentwicklung/Fischereiamt des Landes Berlin for sDDT ({sigma} DDT, DDE, DDD, DDMU), sHCH ({sigma}{alpha}-, {beta}-, {gamma}-, {delta}-, {epsilon}-HCH), sPCB ({sigma} Cong. 28, 52, 101, 138, 153, 180) and HCB in surface water, surface sediment, suspended matter, breams (Abramis brama) and eels (Anguilla anguilla) a cause-oriented monitoring was elaborated concerning the load of waters of Berlin for the period 1983-2000. The structuring of the data consolidated statistically was made according to longitudinal profiles (Teltowkanal from the entrance to the Griebnitzsee, Spree-Oder-System from Seddinsee via Ober-, Stadt- and Unterspree to the mouth into the Havel in Spandau, the Havel from Niederneuendorfer See till Suedliche Unterhavel, the lakes in Grunewald till the city area in Charlottenburg, the lakes in the north of Berlin) as well as time series. The chemical enterprise in Adlershof/Gruenau which produced DDT containing preparations till 1985 and lindane containing preparations till 1989 was identified as the outstanding source of sDDT and sHCH loads. (orig.) [German] Auf der Basis amtlicher Erhebungen durch die Senatsverwaltung fuer Stadtentwicklung/Fischereiamt des Landes Berlin gewonnene Primaerdaten von sDDT ({sigma} DDT, DDE, DDD, DDMU), sHCH ({sigma}{alpha}-, {beta}-, {gamma}-, {delta}-, {epsilon}-HCH), sPCB ({sigma} Kong. 28, 52, 101, 138, 153, 180) und HCB in Oberflaechenwasser, Oberflaechensediment, Schwebstoffen, Brassen/Bleien (Abramis brama) und Aalen (Anguilla anguilla) wurde ein ursachenorientiertes Monitoring ueber die Belastung Berliner Gewaesser erarbeitet, das den Zeitraum von 1983-2000 umfasst. Die Strukturierung der statistisch aufgearbeiteten Werte erfolgte einmal nach Laengsprofilen (Teltowkanal von der Einfahrt bis zum Griebnitzsee, Spree-Oder-System vom Seddinsee ueber die Ober-, Stadt- und Unterspree bis zur Muendung in die Havel in

  10. EELS study of the inverse martensitic transformation of 2H and 18R Cu-Al-Zn alloys

    International Nuclear Information System (INIS)

    Espinosa-Magana, F.; Ochoa-Lara, M.T.; Lovey, F.; Flores-Zuniga, H.; Rios-Jara, D.

    2010-01-01

    Changes in 3d states occupancy associated with the inverse martensitic transformation in two samples of Cu-Al-Zn alloys with 2H and 18R martensitic structures were investigated by electron energy loss spectroscopy (EELS). The Cu L 2,3 white-lines intensities, which reflect the unoccupied density of states in 3d bands, were measured in situ, during the phase transformation in both the martensite and austenite phases. We find that the white-lines intensity decreases during the inverse transformation, when going from martensite to austenite. Even though the initial 3d occupation numbers in 2H and 18R martensitic structures are different, after the transformation, the 3d occupation numbers in the now austenitic structure have decreased in both samples, indicating that some electrons left Cu 3d bands during phase transformation. Interestingly enough, the occupation numbers in the final phases, which have the same structure, reach the same value, indicating that changes in EELS spectra are a consequence of structural changes.

  11. EELS study of the inverse martensitic transformation of 2H and 18R Cu-Al-Zn alloys

    Energy Technology Data Exchange (ETDEWEB)

    Espinosa-Magana, F., E-mail: francisco.espinosa@cimav.edu.m [Centro de Investigacion en Materiales Avanzados, S.C., Laboratorio Nacional de Nanotecnologia, Miguel de Cervantes 120, Complejo Industrial Chihuahua, Chihuahua, Chih. 31109 (Mexico); Ochoa-Lara, M.T. [Centro de Investigacion en Materiales Avanzados, S.C., Laboratorio Nacional de Nanotecnologia, Miguel de Cervantes 120, Complejo Industrial Chihuahua, Chihuahua, Chih. 31109 (Mexico); Lovey, F. [Centro Atomico Bariloche, 8300 S.C. de Bariloche (Argentina); Flores-Zuniga, H. [Universidad Autonoma de Zacatecaa, Av. Lopez Velarde 801, Zacatecas, Zac. 98060 (Mexico); Rios-Jara, D. [Instituto Potosino de Investigacion Cientifica y Tecnologica, Camino a la Presa San Jose 2055, San luis Potosi, S.L.P. 78126 (Mexico)

    2010-01-01

    Changes in 3d states occupancy associated with the inverse martensitic transformation in two samples of Cu-Al-Zn alloys with 2H and 18R martensitic structures were investigated by electron energy loss spectroscopy (EELS). The Cu L{sub 2,3} white-lines intensities, which reflect the unoccupied density of states in 3d bands, were measured in situ, during the phase transformation in both the martensite and austenite phases. We find that the white-lines intensity decreases during the inverse transformation, when going from martensite to austenite. Even though the initial 3d occupation numbers in 2H and 18R martensitic structures are different, after the transformation, the 3d occupation numbers in the now austenitic structure have decreased in both samples, indicating that some electrons left Cu 3d bands during phase transformation. Interestingly enough, the occupation numbers in the final phases, which have the same structure, reach the same value, indicating that changes in EELS spectra are a consequence of structural changes.

  12. Application of STEM/EELS to Plasmon-Related Effects in Optical Spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Camden, Jon [Univ. of Notre Dame, IN (United States). Dept. of Chemistry and Biochemistry

    2017-08-15

    In this project we employed EELS/STEM to understand the near-field enhancements that drive current applications of plasmonic nanostructures. In particular, we explore the connection between optical and electron excitation of plasmon modes in metallic nanostructures: (1) Probing the structural parameters and dielectric properties of multimetallic nanoparticles; (2) Characterization of the near-electric-field enhancements obtained upon excitation of the localized surface plasmon resonance and understand the connection between electron- and photon-driven plasmons; (3) Understanding the behavior of molecules in plasmon-enhanced fields which is essential to emerging applications such as plasmon-assisted catalysis and solar energy harvesting.

  13. The community structure of over-wintering larval and small juvenile fish in a large estuary

    DEFF Research Database (Denmark)

    Munk, Peter; Cardinale, Massimiliano; Casini, Michele

    2014-01-01

    and abundances are described, and linkages between ichthyoplankton abundances and corresponding hydrographical information are analysed by GAM methods. Communities were dominated by herring, gobies, butterfish, sprat, pipefishes, lemon sole and European eel (i.e. glass eel), and all the sampled species showed...

  14. Role of BK channels in the apoptotic volume decrease in native eel intestinal cells

    DEFF Research Database (Denmark)

    Lionetto, Maria Giulia; Giordano, Maria Elena; Calisi, Antonio

    2010-01-01

    High conductance Ca(+)-activated K(+) channels (BK channels) have previously been demonstrated in the eel intestine. They are specifically activated following a hypotonic stress and sustain Regulatory Volume Decrease (RVD). The aim of the present work was to address the possible role...... enterocytes that BK channels, which are involved in RVD in these cells, plays also a crucial role in the AVD process and in the progression of apoptosis....

  15. EELS measurements of boron concentration profiles in p-a-Si and nip a-Si solar cells

    DEFF Research Database (Denmark)

    Van Aken, Bas B.; Duchamp, Martial; Boothroyd, Chris

    2012-01-01

    The p-type Si layer in a-Si and μc-Si solar cells on foil needs to fulfil several important requirements. The layer is necessary to create the electric field that separates the photo-generated charge carriers; the doping also increases the conductivity to conduct the photocurrent to the front......-3, using core-loss EELS combined with numerical analysis. We control the band gap and activation energy of p-a-SiC by varying the B2H6 and CH4 flow during deposition in the process chamber. We have found a linear relation between the activation energy of the dark conductivity Eact and the optical...... band gap E04. Modelling shows that the optimum efficiency in nip solar cells is obtained when the p-a-SiC band gap is slightly larger than the band gap of the absorber layer. We have assessed the potential of core-loss EELS for detecting B and C concentrations as low as 1020cm-3 in a spatially resolved...

  16. A hybrid method using the widely-used WIEN2k and VASP codes to calculate the complete set of XAS/EELS edges in a hundred-atoms system.

    Science.gov (United States)

    Donval, Gaël; Moreau, Philippe; Danet, Julien; Larbi, Séverine Jouanneau-Si; Bayle-Guillemaud, Pascale; Boucher, Florent

    2017-01-04

    Most of the recent developments in EELS modelling has been focused on getting a better agreement with measurements. Less work however has been dedicated to bringing EELS calculations to larger structures that can more realistically describe actual systems. The purpose of this paper is to present a hybrid approach well adapted to calculating the whole set of localised EELS core-loss edges (at the XAS level of theory) on larger systems using only standard tools, namely the WIEN2k and VASP codes. We illustrate the usefulness of this method by applying it to a set of amorphous silicon structures in order to explain the flattening of the silicon L 2,3 EELS edge peak at the onset. We show that the peak flattening is actually caused by the collective contribution of each of the atoms to the average spectrum, as opposed to a flattening occurring on each individual spectrum. This method allowed us to reduce the execution time by a factor of 3 compared to a usual-carefully optimised-WIEN2k calculation. It provided even greater speed-ups on more complex systems (interfaces, ∼300 atoms) that will be presented in a future paper. This method is suited to calculate all the localized edges of all the atoms of a structure in a single calculation for light atoms as long as the core-hole effects can be neglected.

  17. Diel and seasonal movements by adult Sacramento pikeminnow (Ptychocheilus grandis) in the Eel River, northwestern California

    Science.gov (United States)

    Bret C. Harvey; Rodney J. Nakamoto

    1999-01-01

    Abstract - In late summer and fall, radio-tagged adult Sacramento pike-minnow (Ptychocheilus grandis) at three sites in the Eel River of northwestern California moved more at night than during the day. Fish moved up to 535 m at night and returned to their original positions the following morning. Adult Sacramento pikeminnow at all sites occupied only pools during the...

  18. Surface refinement and electronic properties of graphene layers grown on copper substrate: An XPS, UPS and EELS study

    Czech Academy of Sciences Publication Activity Database

    Siokou, A.; Ravani, F.; Karakalos, S.; Frank, Otakar; Kalbáč, Martin; Galiotis, C.

    2011-01-01

    Roč. 257, č. 23 (2011), s. 9785-9790 ISSN 0169-4332 R&D Projects: GA MŠk LC510; GA AV ČR IAA400400911 Institutional research plan: CEZ:AV0Z40400503 Keywords : graphene * XPS * EELS Subject RIV: CG - Electrochemistry Impact factor: 2.103, year: 2011

  19. Towards atomically resolved EELS elemental and fine structure mapping via multi-frame and energy-offset correction spectroscopy.

    Science.gov (United States)

    Wang, Yi; Huang, Michael R S; Salzberger, Ute; Hahn, Kersten; Sigle, Wilfried; van Aken, Peter A

    2018-01-01

    Electron energy-loss spectroscopy and energy-dispersive X-ray spectroscopy are two of the most common means for chemical analysis in the scanning transmission electron microscope. The marked progress of the instrumentation hardware has made chemical analysis at atomic resolution readily possible nowadays. However, the acquisition and interpretation of atomically resolved spectra can still be problematic due to image distortions and poor signal-to-noise ratio of the spectra, especially for investigation of energy-loss near-edge fine structures. By combining multi-frame spectrum imaging and automatic energy-offset correction, we developed a spectrum imaging technique implemented into customized DigitalMicrograph scripts for suppressing image distortions and improving the signal-to-noise ratio. With practical examples, i.e. SrTiO 3 bulk material and Sr-doped La 2 CuO 4 superlattices, we demonstrate the improvement of elemental mapping and the EELS spectrum quality, which opens up new possibilities for atomically resolved EELS fine structure mapping. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

  20. Site-specific electronic structure analysis by channeling EELS and first-principles calculations.

    Science.gov (United States)

    Tatsumi, Kazuyoshi; Muto, Shunsuke; Yamamoto, Yu; Ikeno, Hirokazu; Yoshioka, Satoru; Tanaka, Isao

    2006-01-01

    Site-specific electronic structures were investigated by electron energy loss spectroscopy (EELS) under electron channeling conditions. The Al-K and Mn-L(2,3) electron energy loss near-edge structure (ELNES) of, respectively, NiAl2O4 and Mn3O4 were measured. Deconvolution of the raw spectra with the instrumental resolution function restored the blunt and hidden fine features, which allowed us to interpret the experimental spectral features by comparing with theoretical spectra obtained by first-principles calculations. The present method successfully revealed the electronic structures specific to the differently coordinated cationic sites.

  1. The diet and feeding ecology of Conger conger (L. 1758 in the deep waters of the Eastern Ionian Sea

    Directory of Open Access Journals (Sweden)

    A. ANASTASOPOULOU

    2013-06-01

    Full Text Available The diet of the European conger eel Conger conger was investigated for the first time in the Eastern Mediterranean. Fish dominated the European conger eel diet in the deep waters of E. Ionian Sea. All other prey taxa were identified as accidental preys. However, intestine analysis showed that Natantia, Brachyura and Cephalopoda might have a more important contribution in the diet of the species. C. conger exhibited a benthopelagic feeding behavior as it preyed upon both demersal and mesopelagic taxa. The high vacuity index and the low stomach and intestine fullness indicated that the feeding intensity of the species in the deep waters of Eastern Ionian Sea was quite low. C. conger feeding strategy was characterised by specialisation in various resource items. A between-phenotype contribution to niche width was observed for some prey categories. European Conger eel feeding specialisation seemed to be an adaptation to a food-scarce environment, as typified in deep-water habitats

  2. Shelf-life extension of preservative-free hydrated feed using gamma pasteurization and its effect on growth performance of eel

    International Nuclear Information System (INIS)

    Kim, Dongho; Song, Hyunpa; Lim, Sangyong; Jo, Minho; Song, Duseop; Jo, Cheorun

    2012-01-01

    Hydrated feed (HF) promotes the growth performance and shortens the feeding time of fish by increasing the efficiency of digestion. However, the shelf-life of HF is a concern due to its relatively higher water content. In this study, radiation pasteurization was applied to improve the shelf-life and microbiological quality of HF for fish farming. Preservative-free HF containing 25% moisture was gamma-irradiated and its microbiological and nutritional properties evaluated in addition to a practical feeding trial carried out using eel. The viable counts of bacteria and fungi in HF were 10 6 and 10 4 CFU/g, respectively. All coliform bacteria and yeast in HF were eliminated by irradiation at a dose of 5 kGy, and total aerobic bacteria were eliminated at 10 kGy. The shelf-life of the preservative-free and irradiated (10 kGy) HF was estimated as 6 months under ambient conditions. The nutritional composition of HF was stable up to 10 kGy of irradiation. Based on a feeding trial, it was proven that eel fed HF had about 20% higher growth rate than that fed dried feed. - Highlights: ► Hydrated feed (HF) promotes the growth performance and shortens the feeding time of fish but shelf-life is a concern. ► Radiation pasteurization was applied to improve the shelf-life and microbiological quality of HF for fish farming. ► The shelf-life of the preservative-free and irradiated (10 kGy) HF was estimated as 6 months under ambient conditions. ► Eel fed HF had about 20% higher growth rate than that fed dried feed in feeding trial.

  3. Heavy Metals Uptake by Asian Swamp Eel, Monopterus albus from Paddy Fields of Kelantan, Peninsular Malaysia: Preliminary Study.

    Science.gov (United States)

    Yin, Sow Ai; Ismail, Ahmad; Zulkifli, Syaizwan Zahmir

    2012-12-01

    Swamp eel, Monopterus albus is one of the common fish in paddy fields, thus it is suitable to be a bio-monitor for heavy metals pollution studies in paddy fields. This study was conducted to assess heavy metals levels in swamp eels collected from paddy fields in Kelantan, Malaysia. The results showed zinc [Zn (86.40 μg/g dry weight)] was the highest accumulated metal in the kidney, liver, bone, gill, muscle and skin. Among the selected organs, gill had the highest concentrations of lead (Pb), cadmium (Cd) and nickel (Ni) whereas muscle showed the lowest total metal accumulation of Zn, Pb, copper (Cu), Cd and Ni. Based on the Malaysian Food Regulation, the levels of Zn and Cu in edible parts (muscle and skin) were within the safety limits. However, Cd, Pb and Ni exceeded the permissible limits. By comparing with the maximum level intake (MLI), Pb, Ni and Cd in edible parts can still be consumed. This investigation indicated that M. albus from paddy fields of Kelantan are safe for human consumption with little precaution.

  4. Proof of U(VI) sorption on Acidovorax facilis by TRLFS and EF-TEM/EELS

    Energy Technology Data Exchange (ETDEWEB)

    Krawczyk-Baersch, Evelyn; Gerber, Ulrike [Helmholtz-Zentrum Dresden-Rossendorf e.V., Dresden (Germany). Div. Biogeochemistry; Steudtner, Robin [Helmholtz-Zentrum Dresden-Rossendorf e.V., Dresden (Germany). Div. Surface Processes

    2016-07-01

    In EF-TEM/EELS studies it was shown that U(VI) is sorbed mainly on the outer membrane of Acidovorax facilis. The results are supported by TRLFS measurements, which were performed on the pellet of the cells. In comparison to reference spectra of some cell membrane components, the measured emission spectra of the A. facilis pellet show the best agreement with those of the Uranyl-lipopolysaccharide-complex. Hence, it can be concluded that phosphoryl groups may be the main binding sites for uranyl, located in the lipopolysaccharide unit in the outer membrane.

  5. Phenolic Lipids Affect the Activity and Conformation of Acetylcholinesterase from Electrophorus electricus (Electric eel)

    Science.gov (United States)

    Stasiuk, Maria; Janiszewska, Alicja; Kozubek, Arkadiusz

    2014-01-01

    Phenolic lipids were isolated from rye grains, cashew nutshell liquid (CNSL) from Anacardium occidentale, and fruit bodies of Merrulius tremellosus, and their effects on the electric eel acetylcholinesterase activity and conformation were studied. The observed effect distinctly depended on the chemical structure of the phenolic lipids that were available for interaction with the enzyme. All of the tested compounds reduced the activity of acetylcholinesterase. The degree of inhibition varied, showing a correlation with changes in the conformation of the enzyme tested by the intrinsic fluorescence of the Trp residues of the protein. PMID:24787269

  6. Observations and modeling of wave-supported sediment gravity flows on the Po prodelta and comparison to prior observations from the Eel shelf

    Science.gov (United States)

    Traykovski, P.; Wiberg, P. L.; Geyer, W. R.

    2007-02-01

    A mooring and tripod array was deployed from the fall of 2002 through the spring of 2003 on the Po prodelta to measure sediment transport processes associated with sediment delivered from the Po River. Observations on the prodelta revealed wave-supported gravity flows of high concentration mud suspensions that are dynamically and kinematically similar to those observed on the Eel shelf [Traykovski, P., Geyer, W.R., Irish, J.D., Lynch, J.F., 2000. The role of wave-induced density-driven fluid mud flows for cross-shelf transport on the Eel River continental shelf. Continental Shelf Research 20, 2113-2140]. Due to the dynamic similarity between the two sites, a simple one-dimensional (1D) across-shelf model with the appropriate bottom boundary condition was used to examine fluxes associated with this transport mechanism at both locations. To calculate the sediment concentrations associated with the wave-dominated and wave-current resuspension, a bottom boundary condition using a reference concentration was combined with an "active layer" formulation to limit the amount of sediment in suspension. Whereas the wave-supported gravity flow mechanism dominated the transport on the Eel shelf, on the Po prodelta flux due to this mechanism is equal in magnitude to transport due to wave resuspension and wind-forced mean currents in the cross-shore direction. Southward transport due to wave resuspension and wind forced mean currents move an order of magnitude more sediment along-shore than the down-slope flux associated wave-supported gravity flows.

  7. Characterization of Nb Superconducting Radio Frequency Cavities Based On In-Situ STEM And EELS

    Science.gov (United States)

    Tao, Runzhe

    Niobium, a 4d transition metal, has the highest superconducting transition temperature (Tc=9.2K) of any elemental superconductor as type II superconductor with coherent length, sigma approximately that of the penetration length, lambda. Pure niobium is grey in color and very soft, which makes this metal easily fabricable into different shapes for superconducting radio- frequency (SRF) cavities. Such cavities are used in some modern accelerators (SNS, CEBAF, XFEL), and are intended for usage in the next generation of particle accelerators, such as ILC. Since the crucial part of the cavities is top 100 nm of Nb near the inner cavity surface, considering the penetration depth is around 40 nm, it has attracted more and more attention in improving the surface process for optimizing the performance of the cavities. Nowadays, the main treatment of the Nb surface includes electro polishing (EP), buffered chemical polishing (BCP), high temperature baking (800 °C, 1000 °C and 1200 °C) and mild baking (120 °C). Firstly, the two half cells are welded together and the weld line is quite rough; there exists a lot of visible pits and defects on the inner shell of cavities. In this Ph.D. thesis, novel techniques in a scanning transmission electron microscope (STEM) that can be used to analyze the atomic scale structure-property relationship, both at room tem- perature and high/LN 2 temperature, are explored. Specifically, by using correlated Z-contrast imaging and electron energy loss spectrum (EELS), the structure, composition and bonding can be characterized directly on the atomic scale, also, light atoms, like H, O and C, are visible in ABF images. For the examining the defect behavior on the cavity surface, heating and cold stages are involved to simulate the baking treatment and low-temperature environments. These studies will serve as an important reference for qualifying different surface treatments to further improve SRF cavities' performance. The experimental results

  8. Comparative proteomics analysis of degenerative eye lenses of nocturnal rice eel and catfish as compared to diurnal zebrafish

    Science.gov (United States)

    Lin, Yi-Reng; Mok, Hin-Kiu; Wu, Yuan-Heng; Liang, Shih-Shin; Hsiao, Chang-Chun; Huang, Chun-Hao

    2013-01-01

    Purpose The aim of this study was to determine the lens crystallin diversity of degenerative eyes from the rice eel (Monopterus albus) and walking catfish (Clarias batrachus) as compared to that of zebrafish (Danio rerio) by using comparative proteomics methodologies. We endeavored to investigate the evolution of vertebrate lenses particularly concerning the functional loss of lenses in degenerative eyes of rice eels and catfishes living under an environment of perpetual darkness. Methods Fish lenses were collected and homogenized to extract total soluble proteins. The protein mixtures were separated by one- and two-dimensional gel electrophoresis (1D or 2D gel), plus the newer gel-free shotgun proteomic strategy, followed by in-gel digestion and subjection of the digested protein bands or spots to liquid chromatography coupled with tandem mass spectrometry. The proteomics data were analyzed and compared based on the proteomics databank of zebrafish. The soluble lens protein solutions of three piscine species were also processed by gel-filtration chromatography and 1D sodium dodecyl sulfate–polyacrylamide gel electrophoresis for the comparison and validation of various crystallin families, e.g., α-, β-, and γ-crystallins. Results In zebrafish eye lenses, γ-crystallin constituted about 71% and α- and β-crystallins comprised 30% of total lens proteins. In rice eel lenses, very little or almost no α-crystallins were detected and β- and γ-crystallins comprised more than 98% of total lens proteins. In catfish lenses, α- and β-crystallins comprised about 40% and γ-crystallin constitutes 60% of total lens proteins. It was of interest to find that α-crystallin was totally absent in the rice eel in contrast to the presence, albeit with very low amounts, of α-crystallin in similarly nocturnal catfish. The ratio of α-crystallin subunits (αA/αB) was found to be about 20:1 for the catfish lens, in great contrast to the ratio of about 3:1 found for most

  9. Proteomic analysis of three gonad types of swamp eel reveals genes differentially expressed during sex reversal

    OpenAIRE

    Sheng, Yue; Zhao, Wei; Song, Ying; Li, Zhigang; Luo, Majing; Lei, Quan; Cheng, Hanhua; Zhou, Rongjia

    2015-01-01

    A variety of mechanisms are engaged in sex determination in vertebrates. The teleost fish swamp eel undergoes sex reversal naturally and is an ideal model for vertebrate sexual development. However, the importance of proteome-wide scanning for gonad reversal was not previously determined. We report a 2-D electrophoresis analysis of three gonad types of proteomes during sex reversal. MS/MS analysis revealed a group of differentially expressed proteins during ovary to ovotestis to testis transf...

  10. Fishery and Aquaculture Relationship in the Mediterranean: Present and Future

    Directory of Open Access Journals (Sweden)

    G. RELINI

    2003-12-01

    Full Text Available Although the Mediterranean represents only 0.8% of the world seas, it is the site of a very long-established fishing activity, characterized mainly by multispecific catch and by artisanal or coastal activity, resulting from a mosaic of very diversified structures and gears, along more than 45,000 km of coastline. Two main biological features of this sea are the occurrence of a large richness of species (it represents 5.5% - 7% of world marine fauna and 16.6% of macrophyta, which stands in contrast with its ‘trophic poverty’ and the absence of large monospecific fishery, except for some small and large pelagic fish. Another biological characteristic of Mare Nostrumis the high invasion of exotic species, some exploited by fishery and aquaculture, some others quite dangerous. For the entire Mediterranean and Black Sea, the production (catch + aquaculture had been steadily increasing over the period 1972-1988 from 1,140,000 t to 2,080,000 t . The period 1988-1991 has shown a drastic drop in catches (in 1991: 1,400,000 t. From 1990 to 1995 the total catch increased to 1,701,379 t then decreased and in 2000 reached 1,485,046 t . In 2000 Turkey had the first place with 496,174 t, 26.9% of the total value (1,846,026 t, including fishing and aquaculture, followed by Italy with 25%, Greece 9%, Spain 7.6% and Algeria 5.4%. As in many parts of the world, aquaculture production in the Mediterranean is rapidly expanding. In 1970 the total aquaculture production was about 18,297 t of which 74.3% produced in Italy. In 2000 a value of 358,614 t was reached, about 1/4 of the total fishery catch, while the world aquaculture production corresponds to half of the world total catch. Italy is still the main producer with 46.7% , followed by Greece with 21.5%, Turkey 9.9% and France 6.7%. A sharp drop in the production of the European eel ( Anguilla anguilla and of the European flat oyster ( Ostrea edulis is recorded. Positive and negative interactions between

  11. Invading species in the Eel River, California: Successes, failures, and relationships with resident species

    Science.gov (United States)

    Brown, L.R.; Moyle, P.B.

    1997-01-01

    We examined invasions of non-native fishes into the Eel River, California. At least 16 species of fish have been introduced into the drainage which originally supported 12-14 fish species. Our study was prompted by the unauthorized introduction in 1979 of Sacramento squawfish, Ptychocheilus grandis, a large predatory cyprinid. From 1986 to 1990, we conducted growth and diet studies of squaw fish, conducted intensive surveys of the distribution and habitat associations of both native and introduced species, and examined the nature of species-habitat and interspecies relationships. We found no evidence for increased growth or expanded feeding habits, compared to native populations, of Sacramento squawfish as they invaded the Eel River drainage. Ten of the introduced species were well established, with four species limited to a reservoir and six species established in streams. The success or failure of introductions of stream species appeared to be a function of the ability of a species to survive the fluctuating, highly seasonal, flow regime. The present mixture of native and exotic species has not formed stable fish assemblages but it seems likely that four habitat-associated assemblages will develop. The overall effect of the successful species introductions has been to assemble a group of species, with some exceptions, that are native to and occur together in many California streams. The assemblages now forming are similar to those found in other California streams. The assemblage characterized by squawfish and suckers is likely to be resistant to invasion, in the absence of human caused habitat modifications.

  12. Biological recipient control at the Ringhals nuclear power plant. Annual report for 2011

    International Nuclear Information System (INIS)

    Jansson, Maria; Gustavsson, Frida; Fagerholm, Bjoern

    2012-01-01

    The cooling system of the Ringhals nuclear power plant affects the fish community in two steps. In the first step, seawater is used to cool the system in the nuclear power plant. Fish eggs, larvae and small juveniles are carried by the incoming water and are exposed to risk of damage or mortality. In the second step the heated water is released back into the sea, where the fish is affected by the increase in temperature. Reactor 1 and reactor 3 at Ringhals nuclear power plant produced electricity during the major part of the year 2011, with exceptions for the annual audits, and shorter stops in production. Reactor 2 only operated between January and April, due to a fire which led to a shutdown and a thorough remediation work during the rest of the year. Reactor 4 was producing electricity from January to June, but was later shutdown due to a prolonged annual audit until November. Fish eggs and fish larvae are sampled in the incoming cooling water using a modified Bongo net to monitor losses of eggs and larvae in the nuclear power plant. The abundance of shorthorn sculpin larvae (Myoxocephalus scorpius) has decreased since the sampling period started, although it is still the most abundant larvae. Also the abundance of rock gunnel larvae (Pholis gunnellus) has decreased over the years. To sample juvenile fish a modified Isaacs-Kidd midwater-trawl is used. This sampling is mainly focused on glass eels (Anguilla anguilla). The abundance of glass eels have declined strongly since the beginning of the 1980's, but a minor increase was observed in 2011. The decline of the glass eel abundance is most probably due to a general decrease in recruitment and not to a local effect caused by the nuclear power plant. The effects of the heated water released into the sea are monitored by fykenet surveys in the recipient as well as in a reference area. These two areas are monitored in two seasons to compare differences between the two areas in naturally cold and warm water of the

  13. Biological recipient control at the Ringhals nuclear power plant. Annual report for 2011; Biologisk recipientkontroll vid Ringhals kaernkraftverk. Aarsrapport foer 2011

    Energy Technology Data Exchange (ETDEWEB)

    Jansson, Maria; Gustavsson, Frida; Fagerholm, Bjoern

    2012-07-01

    The cooling system of the Ringhals nuclear power plant affects the fish community in two steps. In the first step, seawater is used to cool the system in the nuclear power plant. Fish eggs, larvae and small juveniles are carried by the incoming water and are exposed to risk of damage or mortality. In the second step the heated water is released back into the sea, where the fish is affected by the increase in temperature. Reactor 1 and reactor 3 at Ringhals nuclear power plant produced electricity during the major part of the year 2011, with exceptions for the annual audits, and shorter stops in production. Reactor 2 only operated between January and April, due to a fire which led to a shutdown and a thorough remediation work during the rest of the year. Reactor 4 was producing electricity from January to June, but was later shutdown due to a prolonged annual audit until November. Fish eggs and fish larvae are sampled in the incoming cooling water using a modified Bongo net to monitor losses of eggs and larvae in the nuclear power plant. The abundance of shorthorn sculpin larvae (Myoxocephalus scorpius) has decreased since the sampling period started, although it is still the most abundant larvae. Also the abundance of rock gunnel larvae (Pholis gunnellus) has decreased over the years. To sample juvenile fish a modified Isaacs-Kidd midwater-trawl is used. This sampling is mainly focused on glass eels (Anguilla anguilla). The abundance of glass eels have declined strongly since the beginning of the 1980's, but a minor increase was observed in 2011. The decline of the glass eel abundance is most probably due to a general decrease in recruitment and not to a local effect caused by the nuclear power plant. The effects of the heated water released into the sea are monitored by fykenet surveys in the recipient as well as in a reference area. These two areas are monitored in two seasons to compare differences between the two areas in naturally cold and warm water of

  14. Using NASA's Giovanni System to Simulate Time-Series Stations in the Outflow Region of California's Eel River

    Science.gov (United States)

    Acker, James G.; Shen, Suhung; Leptoukh, Gregory G.; Lee, Zhongping

    2012-01-01

    Oceanographic time-series stations provide vital data for the monitoring of oceanic processes, particularly those associated with trends over time and interannual variability. There are likely numerous locations where the establishment of a time-series station would be desirable, but for reasons of funding or logistics, such establishment may not be feasible. An alternative to an operational time-series station is monitoring of sites via remote sensing. In this study, the NASA Giovanni data system is employed to simulate the establishment of two time-series stations near the outflow region of California s Eel River, which carries a high sediment load. Previous time-series analysis of this location (Acker et al. 2009) indicated that remotely-sensed chl a exhibits a statistically significant increasing trend during summer (low flow) months, but no apparent trend during winter (high flow) months. Examination of several newly-available ocean data parameters in Giovanni, including 8-day resolution data, demonstrates the differences in ocean parameter trends at the two locations compared to regionally-averaged time-series. The hypothesis that the increased summer chl a values are related to increasing SST is evaluated, and the signature of the Eel River plume is defined with ocean optical parameters.

  15. The Indo-Pacific striped eel catfish, Plotosus lineatus (Thunberg, 1787, (Osteichtyes: Siluriformes, a new record from the Mediterranean

    Directory of Open Access Journals (Sweden)

    Daniel Golani

    2002-09-01

    Full Text Available The striped eel catfish, Plotosus lineatus (Thunberg, 1787, is recorded for the first time from the eastern Mediterranean coast of Israel. Seventeen specimens of this highly-venomous fish were caught by a commercial trawler at depths of 20 m. This species´ occurrence in the Mediterranean is the result of migration from the Red Sea via the Suez Canal (Lessepsian migration.

  16. First record of the Indo-Pacific striped eel catfish, Plotosus lineatus (Thunberg, 1787 from Turkish marine waters

    Directory of Open Access Journals (Sweden)

    Servet Ahmet Doğdu

    2016-05-01

    Full Text Available Three specimens of striped eel catfish, Plotosus lineatus (Thunberg, 1787 were caught by a spear gun at depths of 20 m on 4 April 2016 from Iskenderun Bay (Çevlik harbour, Northeastern Mediterranean coast of Turkey. With the present study, P. lineatus is the first time reported from Turkish marine waters, in the Iskenderun Bay, the Northeastern Mediterranean and also this is the first Plotosid species recorded from Turkish Seas.

  17. Beyond the angle of repose: A review and synthesis of landslide processes in response to rapid uplift, Eel River, Northern California

    Science.gov (United States)

    Roering, Joshua J.; Mackey, Benjamin H.; Handwerger, Alexander L.; Booth, Adam M.; Schmidt, David A.; Bennett, Georgina L.; Cerovski-Darriau, Corina

    2015-05-01

    In mountainous settings, increases in rock uplift are often followed by a commensurate uptick in denudation as rivers incise and steepen hillslopes, making them increasingly prone to landsliding as slope angles approach a limiting value. For decades, the threshold slope model has been invoked to account for landslide-driven increases in sediment flux that limit topographic relief, but the manner by which slope failures organize themselves spatially and temporally in order for erosion to keep pace with rock uplift has not been well documented. Here, we review past work and present new findings from remote sensing, cosmogenic radionuclides, suspended sediment records, and airborne lidar data, to decipher patterns of landslide activity and geomorphic processes related to rapid uplift along the northward-migrating Mendocino Triple Junction in Northern California. From historical air photos and airborne lidar, we estimated the velocity and sediment flux associated with active, slow-moving landslides (or earthflows) in the mélange- and argillite-dominated Eel River watershed using the downslope displacement of surface markers such as trees and shrubs. Although active landslides that directly convey sediment into the channel network account for only 7% of the landscape surface, their sediment flux amounts to more than 50% of the suspended load recorded at downstream sediment gaging stations. These active slides tend to exhibit seasonal variations in velocity as satellite-based interferometry has demonstrated that rapid acceleration commences within 1 to 2 months of the onset of autumn rainfall events before slower deceleration ensues in the spring and summer months. Curiously, this seasonal velocity pattern does not appear to vary with landslide size, suggesting that complex hydrologic-mechanical feedbacks (rather than 1-D pore pressure diffusion) may govern slide dynamics. A new analysis of 14 yrs of discharge and sediment concentration data for the Eel River indicates

  18. Feeding on protists and particulates by the leptocephali of the worm eels Myrophis spp. (Teleostei: Anguilliformes: Ophichthidae, and the potential energy contribution of large aloricate protozoa

    Directory of Open Access Journals (Sweden)

    John Jeffrey Govoni

    2010-06-01

    Full Text Available The food sources of the leptocephali of the teleostean superorder Elopomorpha have been controversial, yet observations on the leptocephali of the worm eels, Myrophis spp. (family Ophichthidae collected in the northern Gulf of Mexico indicate active, not passive, feeding. Leptocephali had protists in their alimentary canals. Estimates of the physiological energetics of worm eels indicate that large aloricate protozoa including ciliates could provide substantial energy to these leptocephali toward the end of the premetamorphic and metamorphic stages, given the low energy requirements of metamorphosing leptocephali. Global ocean warming will likely force a shift in oceanic food webs; a shift away from large protozoa toward smaller protists is possible. Such a disruption of the oceanic food webs could further compromise the survival of leptocephali.

  19. Shelf-life extension of preservative-free hydrated feed using gamma pasteurization and its effect on growth performance of eel

    Science.gov (United States)

    Kim, Dongho; Song, Hyunpa; Lim, Sangyong; Jo, Minho; Song, Duseop; Jo, Cheorun

    2012-08-01

    Hydrated feed (HF) promotes the growth performance and shortens the feeding time of fish by increasing the efficiency of digestion. However, the shelf-life of HF is a concern due to its relatively higher water content. In this study, radiation pasteurization was applied to improve the shelf-life and microbiological quality of HF for fish farming. Preservative-free HF containing 25% moisture was gamma-irradiated and its microbiological and nutritional properties evaluated in addition to a practical feeding trial carried out using eel. The viable counts of bacteria and fungi in HF were 106 and 104 CFU/g, respectively. All coliform bacteria and yeast in HF were eliminated by irradiation at a dose of 5 kGy, and total aerobic bacteria were eliminated at 10 kGy. The shelf-life of the preservative-free and irradiated (10 kGy) HF was estimated as 6 months under ambient conditions. The nutritional composition of HF was stable up to 10 kGy of irradiation. Based on a feeding trial, it was proven that eel fed HF had about 20% higher growth rate than that fed dried feed.

  20. Factors affecting the recovery of fish populations in an industrial river. [Brown trout

    Energy Technology Data Exchange (ETDEWEB)

    Turnpenny, A W.M.; Williams, R

    1981-01-01

    The river Ebbw Fawr, an industrial river of South-East Wales, was investigated over a three-year period to follow the re-establishment of fish populations as a result of pollution control measures at coal washeries and a steelworks on the river. These measures were effective in reducing levels of toxic materials and restoring dissolved oxygen levels and pH values acceptable for fish. Five freshwater fish species became established in parts of the river during the study period (1974-77). The brown trout Salmo trutta l. was the first to enter, followed by eel Anguilla anguilla l., stoneloach Noemacheilus barbatulus l., stickleback Gasterosteus aculeatus l. and bullhead Cottus gobio l., respectively. The flounder Platicthys flesus l., a euryhaline species, penetrated the river beyond the upper tidal limit. The minnow Phoxinus phoxinus l., a resident of other parts of the Ebbw system, did not recolonise during the study. Calculated toxicities and the results of fish caging tests indicated that water quality was satisfactory for fish populations throughout the river with the possible exception of a short reach immediately below the steelworks. The absence of fish from some upstream reaches with good water quality was due to the limited numbers of fish available for recolonisation and their restricted movements. Good growth and condition factors among the recolonising brown trout stock suggest that a sport fishery could be developed on the river, though constraints on spawning due to residual silt pollution indicate that stocking with hatchery reared fish will be necessary to maintain trout numbers.

  1. Susceptibility of pike-perch Sander lucioperca to a panel of ranavirus isolates

    DEFF Research Database (Denmark)

    Jensen, Britt Bang; Holopainen, Riikka; Tapiovaara, Hannele

    2011-01-01

    The host range of ranaviruses was investigated by challenging pike-perch (Sander lucioperca) with the following ranavirus isolates: epizootic haematopoietic necrosis virus (EHNV), European sheatfish virus (ESV), European catfish virus (ECV), pike-perch iridovirus (PPIV), short-finned eel virus...

  2. Behaviour of wintering Tundra Swans Cygnus columbianus columbianus at the Eel River delta and Humboldt Bay, California, USA

    Science.gov (United States)

    Black, Jeffrey M.; Gress, Carol; Byers, Jacob W.; Jennings, Emily; Ely, Craig R.

    2010-01-01

    Tundra Swan Cygnus columbianus columbinanus phenology and behaviour at the Eel River delta and southern Humboldt Bay in northern California, USA, is described. Counts made each January from 1963 onwards peaked at 1,502 swans in 1988. Monthly counts recorded during the 2006/07 and 2008/09 winters peaked in February, at 1,033 and 772 swans respectively. Swans roosted on ephemeral ponds at the Humboldt Bay National Wildlife Refuge, on ephemeral ponds within grassland pastures in the vicinity of the Refuge, and perhaps also used the Eel River as a roost. Flights between Refuge roosts and the pastures and ponds occurred in the two hours after sunrise and before dark. In winters 2008/09 and 2009/10, the percentage of cygnets in the flocks was 10.6% and 21.4% respectively, and increased to =31% cygnets each year after most swans had departed from the area in March. Average brood size in 2009/10 was 2.1 cygnets. Daily activities consisted of foraging (44.9% of activities recorded), comfort behaviour (22.1%), locomotion (16.2%) and vigilance (15.5%). Eight neck-collared swans identified in the wintering flock were marked at four locations in different parts of Alaska, up to 1,300 km apart.

  3. Phosphorylation states of the (Na+ + K+)-transporting ATPase in preparations from lamb kidney and electric-eel (Electophorus electricus) electric organ.

    Science.gov (United States)

    Harris, W E; Stahl, W L

    1984-01-01

    Phosphorylation states of the (Na+ + K+)-transporting ATPase were studied in highly purified preparations isolated from electric-eel electric organ and from lamb kidney. The steady-state level of phosphorylated lamb kidney enzyme, obtained by reaction with [gamma-32P]ATP, was not appreciably reduced in the presence of ADP unless oligomycin was present. The phosphorylated form of the electric-eel electric-organ enzyme was reduced by at least 95% under the same conditions, suggesting that the E1P state in the kidney enzyme is more transitory than that in electric organ. The level of phosphorylation from [32P]Pi was higher in the lamb kidney preparation than in the electric-organ preparation, and the difference in stimulation of phosphorylation by ouabain in the two preparations was striking. Ouabain increased the level of phosphorylation by 35% in the kidney preparation and 734% in the electric-organ preparation. The E2P state seems to be stabilized by ouabain in the latter preparation. These findings, as well as the different reactivities of the thiol groups to blocking reagents in these preparations, suggest that the tertiary structure in the enzyme isolated from these two sources is different. PMID:6324756

  4. Scaling of the Surface Plasmon Resonance in Gold and Silver Dimers Probed by EELS

    DEFF Research Database (Denmark)

    Kadkhodazadeh, Shima; de Lasson, Jakob Rosenkrantz; Beleggia, Marco

    2014-01-01

    The dependence of surface plasmon coupling on the distance between two nanoparticles (dimer) is the basis of nanometrology tools such as plasmon rulers. Application of these nanometric rulers requires an accurate description of the scaling of the surface plasmon resonance (SPR) wavelength...... with distance. Here, we have applied electron energy-loss spectroscopy (EELS) and scanning transmission electron microscopy (STEM) imaging to investigate the relationship between the SPR wavelength of gold and silver nanosphere dimers (radius R) and interparticle distance (d) in the range 0.1R .... Instead, within the range 0.1R gold and silver dimers. Despite this common power dependence, consistently larger SPR wavelength shifts are registered for silver for a given change in d, implying...

  5. Z-Contrast STEM Imaging and EELS of CdSe Nanocrystals: Towards the Analysis of Individual Nanocrystal Surfaces

    International Nuclear Information System (INIS)

    Erwin, M.; Kadavanich, A.V.; Kippeny, T.; Pennycook, S.J.; Rosenthal, S.J.

    1999-01-01

    We have applied Atomic Number Contract Scanning Transmission Electron Microscopy (Z-Contrast STEM) and STEM/EELS (Electron Energy Loss Spectroscopy) towards the study of colloidal CdSe semiconductor nanocrystals embedded in MEH-PPV polymer films. Unlike the case of conventional phase-contrast High Resolution TEM, Z-Contrast images are direct projections of the atomic structure. Hence they can be interpreted without the need for sophisticated image simulation and the image intensity is a direct measure of the thickness of a nanocrystal. Our thickness measurements are in agreement with the predicted faceted shape of these nanocrystals. Our unique 1.3A resolution STEM has successfully resolve3d the sublattice structure of these CdSe nanocrystals. In [010] projection (the polar axis in the image plane) we can distinguish Se atom columns from Cd columns. Consequently we can study the effects of lattice polarity on the nanocrystal morphology. Furthermore, since the STEM technique does not rely on diffraction, it is superbly suited to the study of non-periodic detail, such as the surface structure of the nanocrystals. EELS measurements on individual nanocrystals indicate a significant amount (equivalet to 0.5-1 surface monolayers) of oxygen on the nanocrystals, despite processing in an inert atmosphere. Spatially resolved measurements at 7A resolution suggest a surface oxide layer. However, the uncertainty in the measurement precludes definitive assignment at this time. The source of the oxygen is under investigation as well

  6. Advantages of low beam energies in a TEM for valence EELS

    Science.gov (United States)

    Stöger-Pollach, M.; Pongratz, P.

    2010-02-01

    Since the availability of monochromators in transmission electron microscopes (TEMs), electron energy loss spectrometry (EELS) is widely used to determine band gaps and the dielectric properties of semiconductors on a nano-metre scale. Nevertheless, three physical effects hamper straightforward analysis: (a) relativistic energy losses, (b) the delocalization of the energy loss which is in the 10 nano-metreer range for valence losses, and (c) the presence of interface plasmons. When reducing the operation voltage of the TEM one can kill two birds with one stone: (a) the relativistic losses will disappear as soon as veinvestigated sample) and (b) the delocalization will decrease, because it also depends on the energy of the incident electron probe. The determination of the optical properties of quantum structures is discussed in the case of GaP/GaAs interface at 200 keV and 20 keV beam energy, respectively. Further, the influence of the delocalization of the energy loss signal is discussed theoretically and experimentally.

  7. Pseudocapillaria (Ichthyocapillaria) ophisterni sp. n. (Nematoda : Capillariidae) from the swamp-eel Ophisternon aenigmaticum (Pisces) in Mexico.

    Science.gov (United States)

    Moravec, F; Salgado-Maldonado, G; Jiménez-García, I

    2000-04-01

    A new nematode species, Pseudocapillaria ophisterni sp. n., is described from the intestine and rarely from the stomach of the swamp-eel, Ophisternon aenigmaticum Rosen et Greenwood, from Catemaco Lake, Veracruz, Mexico. In having both caudal lobes in the male interconnected by a distinct dorsal membrane, it belongs to the subgenus Ichthyocapillaria. It differs from the three species in this subgenus mainly in possessing either a distinctly longer spicule or a smaller length of oesophagus relative to body length. It also differs in host type and geographical distribution. P. ophisterni is the first capillariid species reported from synbranchiform fishes.

  8. Mercury bioaccumulation along food webs in temperate aquatic ecosystems colonized by aquatic macrophytes in south western France.

    Science.gov (United States)

    Gentès, Sophie; Maury-Brachet, Régine; Guyoneaud, Rémy; Monperrus, Mathilde; André, Jean-Marc; Davail, Stéphane; Legeay, Alexia

    2013-05-01

    Mercury (Hg) is considered as an important pollutant for aquatic systems as its organic form, methylmercury (MeHg), is easily bioaccumulated and bioamplified along food webs. In various ecosystems, aquatic periphyton associated with macrophyte was identified as an important place for Hg storage and methylation by microorganisms. Our study concerns temperate aquatic ecosystems (South Western France) colonized by invasive macrophytes and characterized by high mercury methylation potentials. This work establishes original data concerning Hg bioaccumulation in organisms (plants, crustaceans, molluscs and fish) from five contrasting ecosystems. For low trophic level species, total Hg (THg) concentrations were low (from 27±2ngTHgg(-1)dw in asiatic clam Corbicula fluminea to 418±114ngTHgg(-1)dw in crayfish Procambarus clarkii). THg concentrations in some carnivorous fish (high trophic level) were close to or exceeded the International Marketing Level (IML) with values ranging from 1049±220ngTHgg(-1)dw in pike perch muscle (Sander lucioperca) to 3910±1307ngTHgg(-1)dw in eel muscle (Anguilla Anguilla). Trophic levels for the individuals were also evaluated through stable isotope analysis, and linked to Hg concentrations of organisms. A significant Hg biomagnification (r(2)= 0.9) was observed in the Aureilhan lake, despite the absence of top predator fish. For this site, Ludwigia sp. periphyton, as an entry point of Hg into food webs, is a serious hypothesis which remains to be confirmed. This study provides a first investigation of Hg transfer in the ecosystems of south western France and allows the assessment of the risk associated with the presence of Hg in aquatic food webs. Copyright © 2013 Elsevier Inc. All rights reserved.

  9. EFTEM-EELS characterization of VC and Cr3C2 doped cemented carbides

    International Nuclear Information System (INIS)

    Warbichler, P.; Hofer, F.; Grogger, W.; Lackner, A.

    2001-01-01

    Structure-property correlation plays an important role in the design of advanced materials which are increasingly based on sub-micrometer and sometimes even nanometer grains. In this respect, analytical electron microscopy (AEM) offers a comprehensive range of characterization techniques which are particularly well suited for hard materials: electron diffraction and high resolution electron microscopy for obtaining crystallographic information and especially new emerging techniques such as energy-filtering TEM (EFTEM) and electron energy-loss spectroscopy (EELS) which enable nearly atomic resolution analysis. In this paper we concentrate on EFTEM and HREM investigations of both WC precursor-powders and sintered WC-Co composites doped with vanadium and chromium carbides in order to control the grain growth during the sintering of the ultra fine WC powders. The aim was to locate the distribution of the doping elements in the powders and in the sintered materials. (author)

  10. The use of the DR CALUX bioassay and indicator polychlorinated biphenyls for screening of elevated levels of dioxins and dioxin-like polychlorinated biphenyls in eel.

    NARCIS (Netherlands)

    Hoogenboom, Ron; Bovee, Toine; Traag, Win A; Hoogerbrugge, Ronald; Baumann, Bert; Portier, Liza; Weg, Guido van de; Vries, Jaap de

    2006-01-01

    The DR CALUX bioassay is a very suitable screening method for dioxins and dioxin-like-PCBs in feed and food. This was, e. g. demonstrated in a survey in the Netherlands to control the dioxin levels in eel. The DR CALUX assay, but also indicator polychlorinated biphenyls (PCB) were evaluated as a

  11. An EELS sub-nanometer investigation of the dielectric gate stack for the realization of InGaAs based MOSFET devices

    International Nuclear Information System (INIS)

    Longo, P; Paterson, G W; Craven, A J; Holland, M C; Thayne, I G

    2010-01-01

    In this paper, a subnanometer investigation of the Ga 2 O 3 /GdGaO dielectric gate stack deposited onto InGaAs is presented. Results regarding the influence of the growth conditions on the interface region from a chemical and morphological point of view are presented. The chemical information reported in this paper has been obtained using electron energy loss spectroscopy (EELS) that was carried out in a scanning transmission electron microscope ((S)TEM) showing both spatial and depth resolution.

  12. Algal-mediated ecosystem exchanges in the Eel River drainage network: towards photogrammetric mapping of color to function

    Science.gov (United States)

    Power, M. E.; Welter, J.; Furey, P.; Lowe, R.; Finlay, J. C.; Hondzo, M.; Limm, M.; Bode, C.; Dietrich, W. E.

    2009-12-01

    Seasonal algal proliferations in river networks are typically short-lived (weeks-months) but spatially extensive. They mediate important ecological and biogeochemical exchanges within and between ecosystems. We are investigating correspondence of assemblage color with ecosystem function in the nitrogen-limited Eel River of northern California. During summer base flow following winter floods, Eel algal assemblages are dominated by the green macroalga Cladophora glomerata. New growths are green, but blooms turn yellow as Cladophora filaments are colonized by epiphytic diatoms (Cocconeis spp.). Later, proliferations turn rust colored as epiphytic assemblages became dominated by Epithemia spp., diatoms that contain nitrogen-fixing cyanobacterial endosymbionts. Epithemia-encrusted Cladophora occurs at and downstream of reaches draining > 100 km2 (where summer inundated average channel widths > 25 m), coinciding with a threshold increase in concentration of total dissolved nitrogen. Areal nitrogen fixation rates are 14x higher in rusty algal proliferations than in green, and 3-4x higher than in yellow Cladophora mats. Corresponding increases in insect emergence suggest that nitrogen fixed by cyanobacterial endosymbionts is highly edible. Rates of biomass emergence from rusty Cladophora mats are 12-17 times greater than from green mats, and 8-10 times greater from rusty than from yellow Cladophora mats, because larger taxa emerge from rusty mats (Chironominae versus Ceratopogonidae in yellow mats). Photogrammetric detection of spatial coverage and color changes in algal proliferations may help us track nitrogen fluxes they mediate (riverine loading from the atmosphere via fixation, river to the watershed return via insect emergence) that link riverine to aerial, watershed, and potentially nearshore marine ecosystems at reach to basin scales.

  13. A high resolution EELS study of free-carrier variations in H2+/H+ bombarded (100)GaAs

    International Nuclear Information System (INIS)

    Dubois, L.H.; Schwartz, G.P.

    1984-01-01

    High resolution electron energy loss spectroscopy (EELS) has been used to examine whether thermal recovery of the near-surface free-carrier concentration in Te-doped (100) GaAs is accomplished following low energy (250--1500 eV) hydrogen ion bombardment. For hydrogen ion impact energies below 500 eV, the nominal bulk free-carrier density is recovered by annealing at 725 K for 2 h. For comparable ion doses, the net free-carrier concentration decreases monotonically at higher impact energies under similar annealing conditions. The threshold for damage retention occurs close to the value of transmitted energy which is necessary to create either a Ga or an As interstitial point defect

  14. Eel calcitonin binding site distribution and antinociceptive activity in rats

    International Nuclear Information System (INIS)

    Guidobono, F.; Netti, C.; Sibilia, V.; Villa, I.; Zamboni, A.; Pecile, A.

    1986-01-01

    The distribution of binding site for [ 125 I]-eel-calcitonin (ECT) to rat central nervous system, studied by an autoradiographic technique, showed concentrations of binding in the diencephalon, the brain stem and the spinal cord. Large accumulations of grains were seen in the hypothalamus, the amygdala, in the fasciculus medialis prosencephali, in the fasciculus longitudinalis medialis, in the ventrolateral part of the periventricular gray matter, in the lemniscus medialis and in the raphe nuclei. The density of grains in the reticular formation and in the nucleus tractus spinalis nervi trigemini was more moderate. In the spinal cord, grains were scattered throughout the dorsal horns. Binding of the ligand was displaced equally by cold ECT and by salmon CT(sCT), indicating that both peptides bind to the same receptors. Human CT was much weaker than sCT in displacing [ 125 I]-ECT binding. The administration of ECT into the brain ventricles of rats dose-dependently induced a significant and long-lasting enhancement of hot-plate latencies comparable with that obtained with sCT. The antinociceptive activity induced by ECT is compatible with the topographical distribution of binding sites for the peptide and is a further indication that fish CTs are active in the mammalian brain

  15. Study of dioxin and dioxin-like PCB levels in fatty fish from Sweden 2000-2002

    Energy Technology Data Exchange (ETDEWEB)

    Ankarberg, E.; Bjerselius, R.; Aune, M.; Darnerud, P.O.; Larsson, L.; Andersson, A.; Toernkvist, A.; Glynn, A. [Swedish National Food Administration, Research and Development Dept., Uppsala (Sweden); Tysklind, M.; Bergek, S. [Environmental Chemistry, Umea Univ. (Sweden); Lundstedt-Enkel, K. [Dept. of Environmental Toxicology, Uppsala Univ. (Sweden); Karlsson, L. [Inst. of Freshwater Research, National Board of Fisheries, Aelvkarleby (Sweden)

    2004-09-15

    The levels of PCDD/Fs and PCBs in fatty fish from the Baltic Sea area are still of major concern in Sweden, although the levels have decreased in Baltic Sea biota since the 1970. During later years this decrease seems to have leveled off, and at least dioxin levels in Baltic herring seem to be more or less the same during the last 10 years period. Harmonised EU maximum levels have been established for PCDD/Fs in fish and fishery products for human consumption, and the maximum level is 4 pg WHO-PCDD/F-TEQ/g fresh weight. Certain fatty fish species in the Baltic Sea are shown to have levels of PCDD/Fs exceeding the maximum level. However, because of protective dietary advice, Sweden and Finland have an exemption from the Council regulation that allows national marketing of fish and fishery products that exceed the maximum level for PCDD/F. For dioxin-like PCBs, common EU maximum levels have not yet been established. However, during 2004 the Commission will review the present maximum levels for dioxins in the light of new data, with a particular aim to include dioxin-like PCBs. The Swedish National Food Administration (NFA) has undertaken a survey to analyse the concentrations of PCDD/Fs and dioxin-like PCBs in fatty fish in the Baltic Sea area. The study presents results from analyses of eel (Anguilla anguilla), salmon (Salmo salar), brown trout (Salmo trutta), whitefish (Coregonus lavaretus), herring (Clupea harengus), sprat (Sprattus sprattus), cod (Gadus morhua callarias) and vendace (roe) (from Coregonus albula) from several locations in the Baltic Sea. This study reports the fifth part of the results from the analyses. The entire study is available on www.slv.se as interim reports 1-5.

  16. Effects of vanadium on population growth and Na-K-ATPase activity of the brackish water hydroid Cordylophora caspia

    Energy Technology Data Exchange (ETDEWEB)

    Ringelband, U.; Karbe, L. [Institut fuer Hydrobiologie und Fischereiwissenschaft, Hamburg (Germany)

    1996-07-01

    Vanadium, a relatively abundant heavy metal, enters the environment naturally through rock weathering. A large fraction of vanadium input is of human origin. The combustion of petroleum- and coal-products, which contain relatively high concentrations of vanadium, is one of the most important sources of the enrichment of vanadium in the environment. As it is used as an alloy, and vanadium rich iron-ores of various origin are used in steel production, the residual slag-stones of the steel industry can contain considerable vanadium concentrations. Wherever slag-stones serve as a cheap and convenient material in riverbank reinforcement, vanadium can leach into the aquatic environment. Vanadium is regarded as an essential trace element for higher animals. Cantley et al. indicated a regulatory function of vanadate in vivo. Although considerable information is available on the toxic effects of vanadium on humans, very little is known about the toxicity of vanadium towards aquatic organisms, especially invertebrates. Bell and Sargent have shown an inhibition of Na-K-ATPase activity in gills of the eel Anguilla anguilla. Holleland and Towle have demonstrated the inhibition of Na-K-ATPase activity in the gills of the shore crab Carcinus maenas. The aim of this study was to determine the toxicity of vanadium towards the brackish water hydroid Cordylophora caspia. Hydroids are known to be particularly sensitive to heavy metals and their asexual reproduction can be used in a well-established population growth test. Furthermore, the effects of vanadium on Na-K-ATPase activity in hydroids were studied in in vivo experiments, wherein the animals were exposed to sublethal concentrations of vanadium. In addition, the inhibition of Na-K-ATPase was measured in vitro, by adding vanadium to a microsomal preparation. 16 refs., 4 figs.

  17. Gastrointestinal motor inhibition by exogenous human, salmon, and eel calcitonin in conscious dogs.

    Science.gov (United States)

    Nakamura, H; Asano, T; Haruta, K; Takeda, K

    1995-01-01

    Effects of synthetic eel (E-), salmon (S-), and human (H-) calcitonin (CT) on gastrointestinal motility were studied in conscious beagle dogs, which had been implanted with strain gauge force transducers. Intramuscular administration of E-, S-, or H-CT interrupted gastric migrating motor complexes, digestive pattern, and gastric emptying. The order of potency was E-CT = S-CT > H-CT. Motor inhibition induced by CT occurred independently of plasma immunoreactive motilin levels or hypocalcemia. In addition, E-CT and S-CT induced vomiting without a retrograde giant contraction (RGC) during the postprandial state. Apomorphine or CuSO4 initiated RGC prior to vomiting. RGC induced by apomorphine was inhibited by pretreatment with E-CT as well as hexamethonium, atropine, or surgical vagotomy. E-CT showed no inhibitory effect on nicotine stimulated contraction of isolated guinea-pig ileum. These results suggest that peripherally administered CT inhibits canine gastrointestinal motility at the central nervous system level by lowering vagal activity.

  18. Isolation and characterization of gonadotropin isohormones from the pituitary gland of pike eel (Muraenesox cinereus)

    International Nuclear Information System (INIS)

    Huang, F.-L.; Huang, C.-J.; Lin, S.-H.; Lo, T.-B.; Papkoff, H.

    1981-01-01

    Pike eel gonadotropins were isolated from pituitary glands by 40% alcohol-6% ammonium acetate, pH 5.1 extraction and were purified by DEAE-cellulose chromatography and electrophoresis into four electrophoretically homogeneous forms. These four isohormones were biologically identified as gonadotropins by the stimulation of 32 P-uptake in 1-day-old chick testes, by the induction of ovulation in catfish, and by the in vitro production of testosterone from isolated rat Leydig cells and of androgen from carp testes. The amino acid composition of the isohormones were similar to other known piscine gonadotropins (carp and salmon) and were composed of two non-identical subunits with Tyr and Ser as N-terminal amino acid residues. The molecular weights of two subunits were 15000 and 10500, respectively, as estimated by SDS-gel disc electrophoresis. (author)

  19. Spatially-resolved EEL studies of plasmons in silver filled carbon nanotubes using a dedicated STEM

    International Nuclear Information System (INIS)

    Bangert, U; Harvey, A J; Seepujak, A

    2008-01-01

    Using a dedicated FEG STEM, we present highly spatially-resolved electron energy-loss (EEL) studies of individual multi-walled carbon nanotubes (MWCNTs), each with the inner cavity possessing regions completely filled with silver. The transmission and attenuation of graphite π-collective mode E-fields through the MWCNT walls are established. Noticeable changes in the graphite π-surface mode are witnessed, concomitant with coupling of the silver Mie mode and the graphite π-surface mode. The resulting collective mode is significantly red-shifted to below 5 eV, with considerable intensity in the visible frequency regime. It appears that silver retains its ability to enhance E-fields when surrounded by a MWCNT. Present observations lead to the possibility of collective modes propagating on graphene monolayers being tuned in frequency by the presence of a metal.

  20. Who's in charge here anyway? Polycentric governance configurations and the development of policy on invasive alien species in the semisovereign Caribbean

    Directory of Open Access Journals (Sweden)

    Jetske Vaas

    2017-12-01

    Full Text Available We address the development of policy by polycentric governance configurations, taking Caribbean overseas territories and their advancements on invasive alien species (IAS policy as an example. The British, Dutch, and French islands in the Caribbean address this matter to different degrees, which we analyzed through differences in their type of polycentric governance configuration with their respective European counterpart. We employ a continuum ranging from predominantly polycentric to predominantly monocentric governance configurations to characterize the three case studies. Based on semistructured interviews with government actors, park managers, and NGO employees on Anguilla, Guadeloupe, and St. Eustatius, plus a literature study, we characterize St. Eustatius as highly polycentric and Guadeloupe as becoming increasingly polycentric. Anguilla cannot be considered either of the two, given the virtually absent involvement of the UK. Policy development on IAS showed most progress in Guadeloupe, whereas in Anguilla and St. Eustatius, IAS management is ad hoc. Within these cases, the hampering effect of dispute about the functioning of the configuration was clear. For Guadeloupe, increasing autonomy to decide on policy priorities within a coherent system where standards are set and ample resources made available appears conducive to policy development. That same balance inherent to polycentric systems between autonomy and coherence is hard to strike for St. Eustatius, and currently mainly perceived as a trade-off, hampering policy development. By discussing these three cases, this study illustrates how different polycentric configurations can affect policy development.

  1. Wide-Scope Screening Method for Multiclass Veterinary Drug Residues in Fish, Shrimp, and Eel Using Liquid Chromatography-Quadrupole High-Resolution Mass Spectrometry.

    Science.gov (United States)

    Turnipseed, Sherri B; Storey, Joseph M; Lohne, Jack J; Andersen, Wendy C; Burger, Robert; Johnson, Aaron S; Madson, Mark R

    2017-08-30

    A screening method for veterinary drug residues in fish, shrimp, and eel using LC with a high-resolution MS instrument has been developed and validated. The method was optimized for over 70 test compounds representing a variety of veterinary drug classes. Tissues were extracted by vortex mixing with acetonitrile acidified with 2% acetic acid and 0.2% p-toluenesulfonic acid. A centrifuged portion of the extract was passed through a novel solid phase extraction cartridge designed to remove interfering matrix components from tissue extracts. The eluent was then evaporated and reconstituted for analysis. Data were collected with a quadrupole-Orbitrap high-resolution mass spectrometer using both nontargeted and targeted acquisition methods. Residues were detected on the basis of the exact mass of the precursor and a product ion along with isotope pattern and retention time matching. Semiquantitative data analysis compared MS 1 signal to a one-point extracted matrix standard at a target testing level. The test compounds were detected and identified in salmon, tilapia, catfish, shrimp, and eel extracts fortified at the target testing levels. Fish dosed with selected analytes and aquaculture samples previously found to contain residues were also analyzed. The screening method can be expanded to monitor for an additional >260 veterinary drugs on the basis of exact mass measurements and retention times.

  2. Changes in the Lipid Fraction of Eel Gills after Ionizing Irradiation in Vivo and a Shift from Fresh to Sea Water

    DEFF Research Database (Denmark)

    Hansen, Heinz Johs. Max

    1975-01-01

    Sixteen eels were adapted to tap water for a week. Then eight of them were irradiated with 1000 R γ-radiation and four of the irradiated group and four of the nonirradiated control group were transferred to sea water. The rest remained in tap water. Three days later all were incubated with 14 C...... been irradiated and transferred to sea water. By measuring lipid biosynthesis in gill tissue it was thus possible to show an interaction between the effect of ionizing irradiation and the salinity of the environment, in agreement with previous biological findings....

  3. Proteomic analysis of three gonad types of swamp eel reveals genes differentially expressed during sex reversal.

    Science.gov (United States)

    Sheng, Yue; Zhao, Wei; Song, Ying; Li, Zhigang; Luo, Majing; Lei, Quan; Cheng, Hanhua; Zhou, Rongjia

    2015-05-18

    A variety of mechanisms are engaged in sex determination in vertebrates. The teleost fish swamp eel undergoes sex reversal naturally and is an ideal model for vertebrate sexual development. However, the importance of proteome-wide scanning for gonad reversal was not previously determined. We report a 2-D electrophoresis analysis of three gonad types of proteomes during sex reversal. MS/MS analysis revealed a group of differentially expressed proteins during ovary to ovotestis to testis transformation. Cbx3 is up-regulated during gonad reversal and is likely to have a role in spermatogenesis. Rab37 is down-regulated during the reversal and is mainly associated with oogenesis. Both Cbx3 and Rab37 are linked up in a protein network. These datasets in gonadal proteomes provide a new resource for further studies in gonadal development.

  4. Alexander von Humboldt: galvanism, animal electricity, and self-experimentation part 2: the electric eel, animal electricity, and later years.

    Science.gov (United States)

    Finger, Stanley; Piccolino, Marco; Stahnisch, Frank W

    2013-01-01

    After extensive experimentation during the 1790s, Alexander von Humboldt remained skeptical about "animal electricity" (and metallic electricity), writing instead about an ill-defined galvanic force. With his worldview and wishing to learn more, he studied electric eels in South America just as the new century began, again using his body as a scientific instrument in many of his experiments. As had been the case in the past and for many of the same reasons, some of his findings with the electric eel (and soon after, Italian torpedoes) seemed to argue against biological electricity. But he no longer used galvanic terminology when describing his electric fish experiments. The fact that he now wrote about animal electricity rather than a different "galvanic" force owed much to Alessandro Volta, who had come forth with his "pile" (battery) for multipling the physical and perceptable effects of otherwise weak electricity in 1800, while Humboldt was deep in South America. Humboldt probably read about and saw voltaic batteries in the United States in 1804, but the time he spent with Volta in 1805 was probably more significant in his conversion from a galvanic to an electrical framework for understanding nerve and muscle physiology. Although he did not continue his animal electricity research program after this time, Humboldt retained his worldview of a unified nature and continued to believe in intrinsic animal electricity. He also served as a patron to some of the most important figures in the new field of electrophysiology (e.g., Hermann Helmholtz and Emil du Bois-Reymond), helping to take the research that he had participated in to the next level.

  5. Structure of the Nav1.4-β1 Complex from Electric Eel.

    Science.gov (United States)

    Yan, Zhen; Zhou, Qiang; Wang, Lin; Wu, Jianping; Zhao, Yanyu; Huang, Gaoxingyu; Peng, Wei; Shen, Huaizong; Lei, Jianlin; Yan, Nieng

    2017-07-27

    Voltage-gated sodium (Na v ) channels initiate and propagate action potentials. Here, we present the cryo-EM structure of EeNa v 1.4, the Na v channel from electric eel, in complex with the β1 subunit at 4.0 Å resolution. The immunoglobulin domain of β1 docks onto the extracellular L5 I and L6 IV loops of EeNa v 1.4 via extensive polar interactions, and the single transmembrane helix interacts with the third voltage-sensing domain (VSD III ). The VSDs exhibit "up" conformations, while the intracellular gate of the pore domain is kept open by a digitonin-like molecule. Structural comparison with closed Na v PaS shows that the outward transfer of gating charges is coupled to the iris-like pore domain dilation through intricate force transmissions involving multiple channel segments. The IFM fast inactivation motif on the III-IV linker is plugged into the corner enclosed by the outer S4-S5 and inner S6 segments in repeats III and IV, suggesting a potential allosteric blocking mechanism for fast inactivation. Copyright © 2017 Elsevier Inc. All rights reserved.

  6. Integrated responses of Na+/HCO3- cotransporters and V-type H+-ATPases in the fish gill and kidney during respiratory acidosis.

    Science.gov (United States)

    Perry, S F; Furimsky, M; Bayaa, M; Georgalis, T; Shahsavarani, A; Nickerson, J G; Moon, T W

    2003-12-30

    Using degenerate primers, followed by 3' and 5' RACE and "long" PCR, a continuous 4050-bp cDNA was obtained and sequenced from rainbow trout (Oncorhynchus mykiss) gill. The cDNA included an open reading frame encoding a deduced protein of 1088 amino acids. A BLAST search of the GenBank protein database demonstrated that the trout gene shared high sequence similarity with several vertebrate Na(+)/HCO(3)(-) cotransporters (NBCs) and in particular, NBC1. Protein alignment revealed that the trout NBC is >80% identical to vertebrate NBC1s and phylogenetic analysis provided additional evidence that the trout NBC is indeed a homolog of NBC1. Using the same degenerate primers, a partial cDNA (404 bp) for NBC was obtained from eel (Anguilla rostrata) kidney. Analysis of the tissue distribution of trout NBC, as determined by Northern blot analysis and real-time PCR, indicated high transcript levels in several absorptive/secretory epithelia including gill, kidney and intestine and significant levels in liver. NBC mRNA was undetectable in eel gill by real-time PCR. In trout, the levels of gill NBC1 mRNA were increased markedly during respiratory acidosis induced by exposure to hypercarbia; this response was accompanied by a transient increase in branchial V-type H(+)-ATPase mRNA levels. Assuming that the branchial NBC1 is localised to basolateral membranes of gill cells and operates in the influx mode (HCO(3)(-) and Na(+) entry into the cell), it would appear that in trout, the expression of branchial NBC1 is transcriptionally regulated to match the requirements of gill pHi regulation rather than to match trans-epithelial HCO(3)(-) efflux requirements for systemic acid-base balance. By analogy with mammalian systems, NBC1 in the kidney probably plays a role in the tubular reabsorption of both Na(+) and HCO(3)(-). During periods of respiratory acidosis, levels of renal NBC1 mRNA increased (after a transient reduction) in both trout and eel, presumably to increase HCO(3

  7. AES, EELS and TRIM simulation method study of InP(100 subjected to Ar+, He+ and H+ ions bombardment.

    Directory of Open Access Journals (Sweden)

    Abidri B.

    2012-06-01

    Full Text Available Auger Electron Spectroscopy (AES and Electron Energy Loss Spectroscopy (EELS have been performed in order to investigate the InP(100 surface subjected to ions bombardment. The InP(100 surface is always contaminated by carbon and oxygen revealed by C-KLL and O-KLL AES spectra recorded just after introduction of the sample in the UHV spectrometer chamber. The usually cleaning process of the surface is the bombardment by argon ions. However, even at low energy of ions beam (300 eV indium clusters and phosphorus vacancies are usually formed on the surface. The aim of our study is to compare the behaviour of the surface when submitted to He+ or H+ ions bombardment. The helium ions accelerated at 500V voltage and for 45 mn allow removing contaminants but induces damaged and no stoichiometric surface. The proton ions were accelerated at low energy of 500 eV to bombard the InP surface at room temperature. The proton ions broke the In-P chemical bonds to induce the formation of In metal islands. Such a chemical reactivity between hydrogen and phosphorus led to form chemical species such as PH and PH3, which desorbed from the surface. The chemical susceptibly and the small size of H+ advantaged their diffusion into bulk. Since the experimental methods alone were not able to give us with accuracy the disturbed depth of the target by these ions. We associate to the AES and EELS spectroscopies, the TRIM (Transport and Range of Ions in Matter simulation method in order to show the mechanism of interaction between Ar+, He+ or H+ ions and InP and determine the disturbed depth of the target by argon, helium or proton ions.

  8. HR-EELS study of hydrogen bonding configuration, chemical and thermal stability of detonation nanodiamond films

    Energy Technology Data Exchange (ETDEWEB)

    Michaelson, Sh.; Akhvlediani, R. [Schulich Faculty of Chemistry, Technion-Israel Institute of Technology, Haifa 32000 (Israel); Petit, T.; Girard, H.A.; Arnault, J.C. [CEA, LIST, Diamond Sensors Laboratory, F-91191 Gif sur Yvette (France); Hoffman, A., E-mail: choffman@tx.technion.ac.il [Schulich Faculty of Chemistry, Technion-Israel Institute of Technology, Haifa 32000 (Israel)

    2014-06-01

    Nano-diamond films composed of 3–10 nm grains prepared by the detonation method and deposited onto silicon substrates by drop-casting were examined by high resolution electron energy loss spectroscopy (HR-EELS), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and secondary ion mass spectroscopy (SIMS). The impact of (i) ex-situ ambient annealing at 400 °C and (ii) ex-situ hydrogenation on hydrogen bonding and its thermal stability were examined. In order to clarify the changes in hydrogen bonding configuration detected on the different surfaces as a function of thermal annealing, in-situ hydrogenation by thermally activated atomic hydrogen was performed and examined. This study provides direct evidence that the exposure to ambient conditions and medium temperature ambient annealing have a pronounced effect on the hydrogen-carbon bonding configuration onto the nano-diamond surfaces. In-situ 1000 °C annealing results in irreversible changes of the film surface and partial nano-diamond silicidation.

  9. Monticellia ophisterni n. sp. (Cestoda: Monticelliidae) from the swamp-eel Ophisternon aenigmaticum (Synbranchiformes) from Mexico.

    Science.gov (United States)

    Scholz, T; de Chambrier, A; Salgado-Maldonado, G

    2001-12-01

    Monticellia ophisterni n. sp. is described from the swamp-eel Ophisternon aenigmaticum Rosen and Greenwood (Synbranchiformes: Synbranchidae) from Lake Catemaco, Veracruz, Mexico. The new species is placed into Monticellia because of the cortical position of the testes, ovary, and uterus. It differs from other Monticellia species (with the exception of Monticellia magna (Rego, Santos and Silva, 1974)) in the position of longitudinal musculature that crosses the vitelline follicles, making them paramuscular. The new species can be distinguished from M. magna--which possesses a similar number of testes (107-139), paramuscular vitelline follicles, and numerous gland cells distributed between the apex of the scolex and suckers--in the position of the genital pore (8-21% vs. 19-27%), in the presence of a weak internal longitudinal musculature, in the arrangement of the testes in the median field, and in the absence of a vaginal sphincter. This is the first proteocephalidean tapeworm reported from a synbranchid fish and the first species of Monticellia found in North America.

  10. Persistent organic pollutants (POPs in fish collected from the urban tract of the river Tiber in Rome (Italy

    Directory of Open Access Journals (Sweden)

    Roberto Miniero

    2011-01-01

    Full Text Available European eel and chub samples were analyzed to determine the levels of non-dioxin-like polychlorobiphenyls (NDL-PCBs, polychlorodibenzodioxins (PCDDs and polychlorodibenzofurans (PCDFs, dioxin-like PCBs (DL-PCBs, and brominated polybromodiphenyl ethers (PBDEs in order to evaluate the extent of contamination of the river Tiber along the urban tract through the city of Rome (Italy. All samples presented detectable levels of the chemicals analyzed, and exhibited species-specific differences in terms of congener composition and total concentrations. On average the European eel presented the highest values. In this species the dioxin-like compound sums (WHO-TEQs exceeded the pertinent maximum levels (MLs. Non-ortho PCBs constituted approximately 80% of WHO-TEQ toxicological potential whereas NDL-PCB and PBDE concentrations appeared to match values determined in other polluted aquatic ecosystems where non-point contamination sources were present. The contamination patterns determined in fish tissues seemed to reflect the impact of generic contamination source(s.

  11. Cytogenetic characterization of the strongly electric Amazonian eel, Electrophorus electricus (Teleostei, Gymnotiformes, from the Brazilian rivers Amazon and Araguaia

    Directory of Open Access Journals (Sweden)

    Soraia B.A. Fonteles

    2008-01-01

    Full Text Available A karyotype analysis of the electric eel, Electrophorus electricus (Teleostei, Gymnotiformes, a strongly electric fish from northern South America, is presented. Two female specimens were analyzed, one from the Amazon River and one from the Araguaia River. The specimens had a chromosomal number of 2n = 52 (42M-SM + 10A. C-bands were present in a centromeric and pericentromeric position on part of the chromosomes; some interstitial C-bands were also present. Heteromorphic nucleolus organizer regions (NORs were detected in two chromosome pairs of the specimen from the Amazon River. The chromosome number and karyotype characteristics are similar to those of other Gymnotidae species. The genera Electrophorus and Gymnotus are positioned as the basal lineages in the Gymnotiformes phylogeny.

  12. Persistent chlorinated hydrocarbons (PHC) - end products and intermediate products of technical synthesis processes in surface water of the Rhine region. Vol. 5: Site profiles of persistent chlorinated hydrocarbons - source-oriented monitoring in aquatic media; Persistente chlorierte Kohlenwasserstoffe (PCKW) - End- und Zwischenprodukte technischer Synthesen in Gewaessern der Rheinregion. Band 5 der Reihe: Standortprofile persistenter chlorierter Kohlenwasserstoffe - ursachenorientiertes Monitoring in aquatischen Medien

    Energy Technology Data Exchange (ETDEWEB)

    Heinisch, E.; Kettrup, A.; Bergheim, W.; Wenzel, S.

    2003-07-01

    By evaluating the primary data from 20 regional institutions in the period 1984-2002 about persistent chlorinated hydrocarbons (PCHC) in fishes (eels, Anguilla anguilla; breams, Abramis brama; barbs, Barbus barbus and reaches, Rutilus rutilus), sediment and suspended matter it was tried to mark the burdens and substance profiles for sampling sites on the river Rhine and rivers in BW, Hess, RP and NRW. The compounds investigated were the isomere di-, tri- and tetrachlorobenzenes, penta- and hexachlorobenzene, octachlorostyrene (OCS), hexachlorobutadiene (HCBD) as well as the 6 DIN (IUPAC, Ballschmiter) congeners of the PCB, substances which were - as to the REACH - described as PBT, partly as vPvB substances and regarded as ''priority harmful substances'' (PCBz; HCB, HCBD), respectively. The statistically elaborated single data were summarized in distance profiles and time series, aiming at marking local and regional immissions as well as hints to their origin and current importance. The background of these efforts is the lack of specialized publications about technical synthesis or compulsory yield of the compounds concerning kind, amount and period. Especially tetrachlorobenzene (mainly 1,2,4,5-TeCBz) and HCBD could be defined as indicator substances for past and recent technical synthesis of chloroorganic compounds. The higher chlorinated PCB congeners no. 138, 153 and 180 (HPCB) proved very persistent. The sites of chemical industry in the vicinity of the sampling points Rheinfelden, Grenzach, Lampertheimer Altrhein, Biebesheimer Rhein, Muendung Schwarzbach, Bischofsheim and Griesheim (Main), Hitdorf, Duisburg-Homberg und Huels (Lippe) could be made transparent by maxima and special substance patterns. (orig.) [German] Durch Auswertung von Primaerdaten ueber persistente chlorierte Kohlenwasserstoffe (PCKW) in Fischen (Aale, Anguilla anguilla; Brachsen, Abramis brama; Barben, Barbus barbus und Rotaugen, Rutilus rutilus), Sediment und

  13. First record of ostracods as natural intermediate hosts of Anguillicola crassus, a pathogenic swimbladder parasite of eels Anguilla spp..

    Czech Academy of Sciences Publication Activity Database

    Moravec, František; Nagasawa, K.; Miyakawa, M.

    2005-01-01

    Roč. 66, č. 3 (2005), s. 171-173 ISSN 0177-5103 R&D Projects: GA ČR GA524/03/0061 Institutional research plan: CEZ:AV0Z60220518 Keywords : Physocypria * Anguillicola * Japan Subject RIV: GJ - Animal Vermins ; Diseases, Veterinary Medicine Impact factor: 1.361, year: 2005

  14. Verontreiniging rode aal Nederlandse binnenwateren : monitoring voor sportvisserij 2004-2008

    NARCIS (Netherlands)

    Lee, van der M.K.; Traag, W.A.; Hoek, van der M.; Kotterman, M.J.J.; Hoogenboom, L.A.P.

    2009-01-01

    Rode aal, ook bekend als Europese paling (Anguilla anguilla) werd gebruikt als bioindicator binnen het monitoringsprogramma 'verontreiniging in vis uit de Nederlandse binnenwateren'. In de afgelopen 5 jaar zijn 65 mengmonsters rode aal met een lengte van 30-40 cm onderzocht op de aanwezigheid van

  15. Quantification of bupivacaine hydrochloride and isoflupredone acetate residues in porcine muscle, beef, milk, egg, shrimp, flatfish, and eel using a simplified extraction method coupled with liquid chromatography-triple quadrupole tandem mass spectrometry.

    Science.gov (United States)

    Cho, Sang-Hyun; Park, Jin-A; Zheng, Weijia; Abd El-Aty, A M; Kim, Seong-Kwan; Choi, Jeong-Min; Yi, Hee; Cho, Soo-Min; Afifi, Nehal A; Shim, Jae-Han; Chang, Byung-Joon; Kim, Jin-Suk; Shin, Ho-Chul

    2017-10-15

    In this study, a simple analytical approach has been developed and validated for the determination of bupivacaine hydrochloride and isoflupredone acetate residues in porcine muscle, beef, milk, egg, shrimp, flatfish, and eel using liquid chromatography-tandem mass spectrometry (LC-MS/MS). A 0.1% solution of acetic acid in acetonitrile combined with n-hexane was used for deproteinization and defatting of all tested matrices and the target drugs were well separated on a Waters Xbridge™ C18 analytical column using a mobile phase consisting of 0.1% acetic acid (A) and 0.1% solution of acetic acid in methanol (B). The linearity estimated from six-point matrix-matched calibrations was good, with coefficients of determination ≥0.9873. The limits of quantification (LOQs) for bupivacaine hydrochloride and isoflupredone acetate were 1 and 2ngg -1 , respectively. Recovery percentages in the ranges of 72.51-112.39% (bupivacaine hydrochloride) and 72.58-114.56% (isoflupredone acetate) were obtained from three different fortification concentrations with relative standard deviations (RSDs) of bupivacaine hydrochloride and isoflupredone acetate from porcine muscle, beef, milk, egg, shrimp, flatfish, and eel samples. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. A Hot Knife Through Ice-Cream: Earthflow Response to Channel Incision (Or Channel Response to Earthflows?), Eel River Canyon, California

    Science.gov (United States)

    Mackey, B. H.; Roering, J. J.; McKean, J. A.

    2007-12-01

    Abundant glacier-like earthflow features are recognized as a primary erosional process in the highly erodable Franciscan Melange of the Eel River Basin, CA. Despite their prominence in this "melting ice-cream" topography, many questions regarding their effects on the long term sediment flux from this rapidly eroding basin remain unresolved. For example, does an earthflow's basal shear zone propagate vertically downwards with vertical river incision? What controls the upslope and lateral extent of individual earthflows? How does the erosive power of a river influence the rate of earthflow movement, or conversely do earthflow toe deposits regulate the rate of river incision? Here we present preliminary findings derived from study of 200km2 of lidar data (1m resolution) covering hillslopes adjacent to 30km of the Eel River. Lidar allows detailed analysis of the interaction between earthflows and the drainage network, and we document how inferred changes in local base level are propagated throughout adjacent hillslopes via earthflow movement. The most active earthflows (determined by field surveying and analysis of aerial photos rectified using lidar- generated digital topography) coincide with locally steep sections of channel, while downstream of the most active flows we frequently observe less-active or dormant earthflows. This observation supports the idea that the locations of the most active earthflows coincide with headward propagating knickpoints in the channel. The rate of earthflow movement appears to slow when an earthflow exhausts the upslope area of easily mobilized sediment. Earthflow toes can protrude directly into the channel, causing the channel to narrow and steepen, and even undercut the opposite bank. Large resistant boulders (>2m diameter) transported by the earthflow accumulate in the streambed and appear to both act as a check on further channel incision and earthflow movement. In contrast, areas adjacent to active earthflows exhibit smooth

  17. European Utility Requirements: European nuclear energy

    International Nuclear Information System (INIS)

    Komsi, M.; Patrakka, E.

    1997-01-01

    The work procedure and the content of the European Utility Requirements (EUR) concerning the future LWRs is described in the article. European Utility Requirements, produced by utilities in a number of European countries, is a document specifying the details relating to engineered safety, operating performance, reliability and economics of the reactors to be built by manufacturers for the European market

  18. Measuring the diffusion of Ti and Cu in low-k materials for microelectronic devices by EELS, EFTEM and EDX

    International Nuclear Information System (INIS)

    Barnes, J-P; Lafond, D; Guedj, C; Fayolle, M; Meininger, P; Maitrejean, S; David, T; Posseme, N; Bayle-Guillemaud, P; Chabli, Amal

    2006-01-01

    The need to reduce RC delay and cross talk in Cu interconnects means that ultra low-k dielectrics such as porous SiCOH are being integrated into microelectronic devices. Unfortunately porous materials lead to integration issues such as metal diffusion into the porosity of the dielectric, especially when chemical vapour deposition (CVD) methods are used for metal deposition. In our case, the copper anti-diffusion barrier used before Cu deposition is MOCVD TiN. Without an appropriate surface treatment (pore sealing) of the low-k the TiN may diffuse in the porosity. The presence of Ti or Cu in the low-k is deleterious as it can raise the dielectric constant and the leakage current. EFTEM EELS and EDX have been used to map Ti, Cu, O and C as a function of process conditions

  19. Quantitation of ranaviruses in cell culture and tissue samples

    DEFF Research Database (Denmark)

    Holopainen, Riikka; Honkanen, Jarno; Jensen, Britt Bang

    2011-01-01

    ; European sheatfish virus, ESV; Frog virus 3, FV3; Bohle iridovirus, BIV; Doctor fish virus, DFV; Guppy virus 6, GV6; Pike-perch iridovirus, PPIV; Rana esculenta virus Italy 282/I02, REV282/I02 and Short-finned eel ranavirus, SERV) were detected with the qPCR assay. In addition, two fish cell lines...

  20. Quantitative Study of Interface/Interphase in Epoxy/Graphene-Based Nanocomposites by Combining STEM and EELS.

    Science.gov (United States)

    Liu, Yu; Hamon, Ann-Lenaig; Haghi-Ashtiani, Paul; Reiss, Thomas; Fan, Benhui; He, Delong; Bai, Jinbo

    2016-12-14

    A quantitative study of the interphase and interface of graphene nanoplatelets (GNPs)/epoxy and graphene oxide (GO)/epoxy was carried out by combining scanning transmission electron microscopy (STEM) and electron energy-loss spectroscopy (EELS). The interphase regions between GNPs and epoxy matrix were clearly identified by the discrepancy of the plasmon peak positions in the low energy-loss spectra due to different valence electron densities. The spectrum acquisitions were carried out along lines across the interface. An interphase thickness of 13 and 12.5 nm was measured for GNPs/epoxy and GO/epoxy, respectively. The density of the GNPs/epoxy interphase was 2.89% higher than that of the epoxy matrix. However, the density of the GO/epoxy interphase was 1.37% lower than that of the epoxy matrix. The interphase layer thickness measured in this work is in good agreement with the transition layer theory, which proposed an area with modulus linearly varying across a finite width. The results provide an insight into the interphase for carbon-based polymer composites that can help to design the functionalization of nanofillers to improve the composite properties.

  1. The untold story of the caudal skeleton in the electric eel (ostariophysi: gymnotiformes: electrophorus.

    Directory of Open Access Journals (Sweden)

    Carlos David de Santana

    Full Text Available Alternative hypotheses had been advanced as to the components forming the elongate fin coursing along the ventral margin of much of the body and tail from behind the abdominal region to the posterior margin of the tail in the Electric Eel, Electrophorus electricus. Although the original species description indicated that this fin was a composite of the caudal fin plus the elongate anal fin characteristic of other genera of the Gymnotiformes, subsequent researchers proposed that the posterior region of the fin was formed by the extension of the anal fin posteriorly to the tip of the tail, thereby forming a "false caudal fin." Examination of ontogenetic series of the genus reveal that Electrophorus possesses a true caudal fin formed of a terminal centrum, hypural plate and a low number of caudal-fin rays. The confluence of the two fins is proposed as an additional autapomorphy for the genus. Under all alternative proposed hypotheses of relationships within the order Gymnotiformes, the presence of a caudal fin in Electrophorus optimized as being independent of the occurence of the morphologically equivalent structure in the Apteronotidae. Possible functional advantages to the presence of a caudal fin in the genus are discussed.

  2. Towards optimization of experimental parameters for studying Li-O2 battery discharge products in TEM using in situ EELS.

    Science.gov (United States)

    Basak, Shibabrata; Jansen, Jacob; Kabiri, Yoones; Zandbergen, Henny W

    2018-05-01

    The key to understanding the performance of Li-O 2 batteries is to study the chemical and structural properties of their discharge product(s) at the nanometer scale. Using TEM for this purpose poses challenges due to the sensitivity of samples to air and electron beams. This paper describes our use of in situ EELS to evaluate experimental procedures to reduce electron-beam degradation and presents methods to deal with air sensitivity. Our results show that Li 2 O 2 decomposition is dependent on the total dose and is approximately 4-5 times more pronounced at 80 than at 200 kV. We also demonstrate the benefits of using low-dose-rate STEM. We show further that a "graphene cell", which encapsulates the sample within graphene sheets, can protect the sample against air and e-beam damage. Copyright © 2018 Elsevier B.V. All rights reserved.

  3. Dissolved inorganic carbon, alkalinity, temperature, salinity and other variables collected from discrete sample and profile observations using CTD, bottle and other instruments obtained during the R/V Discovery EEL_2011_D365 Cruise Along Extended Ellett Line from 2011-05-20 to 2011-05-31 (NCEI Accession 0157258)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NCEI Accession 0157258 includes chemical, discrete sample, physical and profile data obtained during the R/V Discovery EEL_2011_D365 Cruise Along Extended Ellett...

  4. The European Social Survey and European research policy

    DEFF Research Database (Denmark)

    Kropp, Kristoffer

    2017-01-01

    This article analyses the history of the European Social Survey (ESS) and its relationship to changes in European research policy, using Bourdieu’s field-analytical approach. It argues that the success of the ESS relied on three interwoven processes that we can understand theoretically in terms...... of the establishment of homological structures and the formation of conjunctural alliances between the field of European social-scientific research and the field of European policy. The three interwoven processes that I depict are: first, the production of a European field of social research, connected to both...... European and national scientific institutions; second, the establishment of European Union (EU) institutions and organisations that were able to identify and link up with social researchers; and third, the formation of conjunctural alliances between the two fields (social science and EU research policy...

  5. Contaminants in tropical island streams and their biota.

    Science.gov (United States)

    Buttermore, Elissa N; Cope, W Gregory; Kwak, Thomas J; Cooney, Patrick B; Shea, Damian; Lazaro, Peter R

    2018-02-01

    Environmental contamination is problematic for tropical islands due to their typically dense human populations and competing land and water uses. The Caribbean island of Puerto Rico (USA) has a long history of anthropogenic chemical use, and its human population density is among the highest globally, providing a model environment to study contaminant impacts on tropical island stream ecosystems. Polycyclic Aromatic Hydrocarbons, historic-use chlorinated pesticides, current-use pesticides, Polychlorinated Biphenyls (PCBs), and metals (mercury, cadmium, copper, lead, nickel, zinc, and selenium) were quantified in the habitat and biota of Puerto Rico streams and assessed in relation to land-use patterns and toxicological thresholds. Water, sediment, and native fish and shrimp species were sampled in 13 rivers spanning broad watershed land-use characteristics during 2009-2010. Contrary to expectations, freshwater stream ecosystems in Puerto Rico were not severely polluted, likely due to frequent flushing flows and reduced deposition associated with recurring flood events. Notable exceptions of contamination were nickel in sediment within three agricultural watersheds (range 123-336ppm dry weight) and organic contaminants (PCBs, organochlorine pesticides) and mercury in urban landscapes. At an urban site, PCBs in several fish species (Mountain Mullet Agonostomus monticola [range 0.019-0.030ppm wet weight] and American Eel Anguilla rostrata [0.019-0.031ppm wet weight]) may pose human health hazards, with concentrations exceeding the U.S. Environmental Protection Agency (EPA) consumption limit for 1 meal/month. American Eel at the urban site also contained dieldrin (range island-wide; only mercury at one site (an urban location) exceeded EPA's consumption limit of 3 meals/month for this species. These results comprise the first comprehensive island-wide contaminant assessment of Puerto Rico streams and biota and provide natural resource and public health agencies here and

  6. Contaminants in tropical island streams and their biota

    Science.gov (United States)

    Buttermore, Elissa N.; Cope, W. Gregory; Kwak, Thomas J.; Cooney, Patrick B.; Shea, Damian; Lazaro, Peter R.

    2018-01-01

    Environmental contamination is problematic for tropical islands due to their typically dense human populations and competing land and water uses. The Caribbean island of Puerto Rico (USA) has a long history of anthropogenic chemical use, and its human population density is among the highest globally, providing a model environment to study contaminant impacts on tropical island stream ecosystems. Polycyclic Aromatic Hydrocarbons, historic-use chlorinated pesticides, current-use pesticides, Polychlorinated Biphenyls (PCBs), and metals (mercury, cadmium, copper, lead, nickel, zinc, and selenium) were quantified in the habitat and biota of Puerto Rico streams and assessed in relation to land-use patterns and toxicological thresholds. Water, sediment, and native fish and shrimp species were sampled in 13 rivers spanning broad watershed land-use characteristics during 2009–2010. Contrary to expectations, freshwater stream ecosystems in Puerto Rico were not severely polluted, likely due to frequent flushing flows and reduced deposition associated with recurring flood events. Notable exceptions of contamination were nickel in sediment within three agricultural watersheds (range 123–336 ppm dry weight) and organic contaminants (PCBs, organochlorine pesticides) and mercury in urban landscapes. At an urban site, PCBs in several fish species (Mountain Mullet Agonostomus monticola [range 0.019–0.030 ppm wet weight] and American Eel Anguilla rostrata [0.019–0.031 ppm wet weight]) may pose human health hazards, with concentrations exceeding the U.S. Environmental Protection Agency (EPA) consumption limit for 1 meal/month. American Eel at the urban site also contained dieldrin (range lipid content) and may be most suitable for human consumption island-wide; only mercury at one site (an urban location) exceeded EPA's consumption limit of 3 meals/month for this species. These results comprise the first comprehensive island-wide contaminant assessment of Puerto Rico

  7. High blood oxygen affinity in the air-breathing swamp eel Monopterus albus.

    Science.gov (United States)

    Damsgaard, Christian; Findorf, Inge; Helbo, Signe; Kocagoz, Yigit; Buchanan, Rasmus; Huong, Do Thi Thanh; Weber, Roy E; Fago, Angela; Bayley, Mark; Wang, Tobias

    2014-12-01

    The Asian swamp eel (Monopterus albus, Zuiew 1793) is a facultative air-breathing fish with reduced gills. Previous studies have shown that gas exchange seems to occur across the epithelium of the buccopharyngeal cavity, the esophagus and the integument, resulting in substantial diffusion limitations that must be compensated by adaptations in others steps of the O₂ transport system to secure adequate O₂ delivery to the respiring tissues. We therefore investigated O₂ binding properties of whole blood, stripped hemoglobin (Hb), two major isoHb components and the myoglobin (Mb) from M. albus. Whole blood was sampled using indwelling catheters for blood gas analysis and determination of O₂ equilibrium curves. Hb was purified to assess the effects of endogenous allosteric effectors, and Mb was isolated from heart and skeletal muscle to determine its O₂ binding properties. The blood of M. albus has a high O₂ carrying capacity [hematocrit (Hct) of 42.4±4.5%] and binds O₂ with an unusually high affinity (P₅₀=2.8±0.4mmHg at 27°C and pH7.7), correlating with insensitivity of the Hb to the anionic allosteric effectors that normally decrease Hb-O₂ affinity. In addition, Mb is present at high concentrations in both heart and muscle (5.16±0.99 and 1.08±0.19mg ∙ g wet tissue⁻¹, respectively). We suggest that the high Hct and high blood O₂ affinity serve to overcome the low diffusion capacity in the relatively inefficient respiratory surfaces, while high Hct and Mb concentration aid in increasing the O₂ flux from the blood to the muscles. Copyright © 2014 Elsevier Inc. All rights reserved.

  8. Bio-accumulation of lanthanum from lanthanum modified bentonite treatments in lake restoration.

    Science.gov (United States)

    Waajen, G; van Oosterhout, F; Lürling, M

    2017-11-01

    Lanthanum (La) modified bentonite (LMB) is one of the available mitigating agents used for the reduction of the phosphorus (P) recycling in eutrophic lakes. The potential toxicity of the La from LMB to aquatic organisms is a matter of concern. In this study the accumulation of La was investigated in the macrophyte Elodea nuttallii, in chironomid larvae and in several fish species during periods up to five years following in situ LMB applications. The application of LMB increased the La concentration of exposed plants and animals. During the first growing season following LMB applications, the La content of E. nuttallii increased 78 fold (3.98-310.68 μg La g -1 DW) to 127 fold (2.46-311.44 μg La g -1 ). During the second growing season following application, the La content decreased but was still raised compared to plants that had not been exposed. The La content of chironomids was doubled in the two years following LMB application, although the increase was not significant. Raised La concentrations in fish liver, bone, muscle and skin were observed two and five years following to LMB application. Liver tissues showed the highest La increase, ranging from 6 fold (0.046-0.285 μg La g -1 DW) to ∼20 fold (0.080-1.886 μg La g -1 , and 0.122-2.109 μg La g -1 ) two years following application and from 6 fold (0.046-0.262 μg La g -1 ) to 13 fold (0.013-0.167 μg La g -1 ) after five years in pelagic and littoral fish. The La content of the liver from Anguilla anguilla (eel) had increased 94 fold (0.034-3.176 μg La g -1 ) two years and 133 fold (0.034-4.538 μg La g -1 ) five years following LMB application. No acute and chronic effects of La accumulation were observed and human health risks are considered negligible. We advocate the long-term study of effects of La accumulation following future LMB applications. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. Study of the order-disorder transition and martensitic transformation in a Cu-Al-Be alloy by EELS

    International Nuclear Information System (INIS)

    Hernandez, J.H.; Ochoa, M.T.; Flores-Zuniga, H.; Espinosa-Magana, F.; Rios-Jara, D.

    2006-01-01

    Changes in 3d states occupancy associated with order-disorder transition and martensitic transformation in a Cu-Al-Be alloy was investigated by electron energy loss spectroscopy (EELS) in both high energy and low energy loss regions. From the high energy loss region, the Cu L 2,3 white-line intensities, which reflect the unoccupied density of states in 3d bands, was measured for three states of the alloy: disordered austenite, ordered austenite and martensite. It was found that the white-line intensity remains the same during order-disorder transition but appears slightly smaller in martensite, indicating that some electrons left Cu 3d bands or some hybridization took place during phase transformation. From the low energy loss region, the optical joint density of states (OJDS) was obtained by Kramers-Kronig analysis. As maxima observed in the OJDS spectra are assigned to interband transitions, these spectra can be used to probe changes in the electronic band structure. The analysis shows that during the martensitic transformation, the peaks positions and relative intensities in the OJDS spectra undergoes noticeable changes, which are associated with interband transitions

  10. Age- and weight-dependent susceptibility of rainbow trout Oncorhynchus mykiss to isolates of infectious haematopoietic necrosis virus (IHNV) of varying virulence

    DEFF Research Database (Denmark)

    Bergmann, S.M.; Fichtner, D.; Skall, Helle Frank

    2003-01-01

    The virulence of 5 European and 1 North American isolate of infectious haematopoietic necrosis virus (IHNV) was compared by infecting female sibling rainbow trout ('lsle of Man' strain) of different weights and ages (2, 20 and 50 g). The fish were exposed to 104 TCID50 IHNV per ml of water...... by immersion, and the mortality was recorded for 28 d. Two new IHNV isolates from Germany were included in the investigation. One was isolated from European eels kept at 23degreesC (+/-2degreesC) and the other was not detectable by immunofluorescence with commercially available monoclonal antibodies...

  11. European communion

    DEFF Research Database (Denmark)

    Manners, Ian James

    2013-01-01

    Political theory of European union, through an engagement between political concepts and theoretical understandings, provides a means of identifying the EU as a political object. It is argued that understanding the projects, processes and products of European union, based on ‘sharing’ or ‘communion......’, provides a better means of perceiving the EU as a political object rather than terms such as ‘integration’ or ‘co-operation’. The concept of ‘European communion’ is defined as the ‘subjective sharing of relationships’, understood as the extent to which individuals or groups believe themselves to be sharing...... relations (or not), and the consequences of these beliefs for European political projects, processes and products. By exploring European communion through an engagement with contemporary political theory, using very brief illustrations from the Treaty of Lisbon, the article also suggests that European...

  12. Performance evaluation of the European Committee Standardization Method EN1785 for the detection of irradiated processed food

    International Nuclear Information System (INIS)

    Tsutsumi, Tomoaki; Adachi, Rika; Takatsuki, Satoshi; Matsuda, Rieko; Teshima, Reiko; Nei, Daisuke; Kameya, Hiromi; Todoriki, Setsuko; Kikuchi, Masahiro; Kobayashi, Yasuhiko

    2014-01-01

    2-dodecylcyclobutanone (DCB) and 2-tetradecylcyclobutanone (TCB) are specific radiolytic products in irradiated lipid-containing food and can be used to detect irradiated foods. We previously reported a performance evaluation test in a single laboratory for qualitative detection methods using DCB and TCB as markers for irradiated foods. EN1785, a European Committee Standardization Method, has been widely used for qualitative detection of DCB and TCB in irradiated foods. Here, we evaluated the applicability of EN1785 to camembert cheese, liquid whole egg, sausage and eel grilled without seasoning by using our evaluation test. In this test, extracted lipids from the food were used as negative samples. The lipids spiked with DCB and TCB were used as positive samples. For each food type, 4 negative and 16 positive samples were analyzed by EN1785. All of the negative samples were judged negative and all of the positive samples were judged positive. Thus, EN1785 should be able to detect irradiation in the tested food. Additionally, to confirm the ability of the validated method to detect irradiated food, the same type of food examined above, both unirradiated and irradiated at doses of 0.5-4 kGy, were analyzed by the method. All of the unirradiated samples were judged negative and all of the irradiated samples were judged positive. (author)

  13. The European Hematology Association Roadmap for European Hematology Research

    DEFF Research Database (Denmark)

    Engert, Andreas; Balduini, Carlo; Brand, Anneke

    2016-01-01

    The European Hematology Association (EHA) Roadmap for European Hematology Research highlights major achievements in diagnosis and treatment of blood disorders and identifies the greatest unmet clinical and scientific needs in those areas to enable better funded, more focused European hematology...... research. Initiated by the EHA, around 300 experts contributed to the consensus document, which will help European policy makers, research funders, research organizations, researchers, and patient groups make better informed decisions on hematology research. It also aims to raise public awareness...... of the burden of blood disorders on European society, which purely in economic terms is estimated at €23 billion per year, a level of cost that is not matched in current European hematology research funding. In recent decades, hematology research has improved our fundamental understanding of the biology...

  14. Eastern Dimension of the European Neighbourhood Policy: Europeanization Mutual Trap

    Directory of Open Access Journals (Sweden)

    V. A. Latkina

    2014-01-01

    Full Text Available The article analyses the Europeanization policy of the European Union towards the Eastern Partnership participant countries. Suffering from the lack of clear strategy and ultimate goal in the European Neighbourhood Policy the European Union enhances external democratization and its governance in post soviet states without immediate Union's membership perspective. Underestimation of common neighbourhood geopolitical duality in the context of growing rivalry between European (EU and Eurasian (Custom Union/Eurasian Economic Union integration gravitation centers presents the Eastern partners of the EU with a fierce dilemma of externally forced immediate geopolitical and civilizational choice while not all of them are well prepared to such a choice. The mutual Europeanization trap here to be studied both for the EU and its Eastern partners (involving Russia is a deficiency of regulating cooperation mechanism in the situation of European and Eurasian free trades zones overlapping. Vilnius Summit 2013 results test the "European aspirations" of the New Independent States and upset the ongoing process of the European Neighbourhood Policy in the context of growing economic interdependence in Wider Europe. Besides, the Ukrainian crisis escalation during 2014 as a new seat of tension provokes unbalance of the whole European security system and creates new dividing lines in Europe from Vancouver to Vladivostok.

  15. Redescription of Heliconema africanum (Linstow, 1899) n. comb. (Nematoda: Physalopteridae), a nematode parasite of freshwater eels (Anguilla spp.) in South Africa

    Czech Academy of Sciences Publication Activity Database

    Moravec, František; Taraschewski, H.; Weyl, O.L.F.

    2013-01-01

    Roč. 85, č. 3 (2013), s. 263-269 ISSN 0165-5752 R&D Projects: GA ČR GBP505/12/G112 Institutional support: RVO:60077344 Keywords : Parasitic nematode * Heliconema * South Africa Subject RIV: EA - Cell Biology Impact factor: 1.035, year: 2013

  16. Phylogeography of the Chinese Beard Eel, Cirrhimuraena chinensis Kaup, Inferred from Mitochondrial DNA: A Range Expansion after the Last Glacial Maximum

    Directory of Open Access Journals (Sweden)

    Hai Li

    2014-08-01

    Full Text Available The Chinese beard eel (Cirrhimuraena chinensis Kaup is an intertidal fish and a model organism for the study of impacts caused by topological fluctuations during the Pleistocene and current intricate hydrological conditions on fauna living in the coastal areas of China. In this study, we examined the phylogeographical pattern, population genetic profile and demographical history of C. chinensis using mitochondrial DNA (cytochrome b (cyt b and control region (CR from 266 individuals sampled in seven localities across the coastal area of southeastern China. The combined data indicated high levels of haplotype diversity and low levels of nucleotide diversity. Analyses of molecular variance (AMOVA and FST statistics suggested the absence of a significant population structure across the Chinese coast. Neutrality tests, mismatch distributions and Bayesian skyline plots uniformly indicated a recent population expansion. The phylogeographic structure of C. chinensis may be attributed to past population expansion and long-distance pelagic larval dispersal facilitated by present-day ocean currents.

  17. European Research Reloaded : Cooperation and Integration Among Europeanized States

    NARCIS (Netherlands)

    Holzhacker, Ron; Haverland, Markus

    2006-01-01

    European integration has had an ever deepening impact on the member states. The first wave of research concerned the process of institution building and policy developments at the European Union (EU) level. The second wave, on Europeanization used the resulting integration as an explanatory factor

  18. The influence of cooling water outlet of the Ringhals power plant on the coastal fish colony

    International Nuclear Information System (INIS)

    Neuman, E.

    1988-03-01

    Fish abundance has been monitored with fyke nets in 1976-1987 at the cooling-water outlet from the Ringhals nuclear power plant at the Swedish west coast and in a reference area. Judging from the dependence of the catches on temperature, Myoxocephalus scorpius, Zoarces viviparus, Gadus morhua and Platichtys flesus can be classified as cold-water species and Symphodus melops, Ctenolabrus rupestris, Carci nus maenas and Anguilla anguilla as warm-water species. As a rule the warm-water species were more and the cold-water fishes less abundant in the outlet area than in the reference area. The catch of the economically important Anguilla was about three times greater in the heated area. A lower abundance than expected of Ctenolabrus and Myoxocephalus at the outlet may be caused by a loss of eggs and larvae in the cooling-water system. (author)

  19. How campaigns enhance European issues voting during European Parliament elections

    DEFF Research Database (Denmark)

    Beach, Derek; Møller Hansen, Kasper; Larsen, Martin Vinæs

    2017-01-01

    Based on findings from the literature on campaign effects on the one hand, and the literature on European Parliament elections on the other, we propose a model of European Parliamentary elections in which the campaign shift the calculus of electoral support, making differences in national political...... allegiances less important and attitudes about the European project more important by informing voters of and getting them interested in European politics. In effect, we argue that the political campaign leading up to the election makes European Parliament elections less second-order. While previous studies...... have demonstrated that EU attitudes can matter for voting behavior in European Parliament elections, existing research has drawn on post-election surveys that do not enable us to capture campaign effects. Our contribution is to assess the impact of a campaign by utilizing a rolling cross sectional...

  20. The European Parliament and the European future of Albania

    Directory of Open Access Journals (Sweden)

    Skerdilajd Bajramaj

    2015-07-01

    Full Text Available On 06.24.2014 Albania was granted the status of candidate country. The foreign ministers of the 28 European Union member states decided unanimously to grant the candidate status for Albania. After receiving the status of “candidate country” for EU membership, the institutional relations with European international bodies are becoming stronger. One of these institutions, which during this time has increased its authority with Albania, is the European Parliament. In this paper will be analyzed the composition, competences and functioning of this particular institution, which is not only important for the future of the European Union and its Member States, but also for those who aim to join in. The study will be based on decisions made by this legislative body, as the only direct representative of the citizens of the European Union, and the impact they have on the performance and functioning of the Member States and the EU itself. In order to verify the validity of these claims, the analysis aims to assess the scope of the legislative function of the European Parliament post-Lisbon, examining its participation in the EU lawmaking both from the point of view of quantity and quality in over the past legislatures. Particular attention has been given to the examination of the changes that have taken place with the entry into force of the Lisbon Treaty, and the areas most affected. We will finally look at the work and contribution of the European Parliament, through the instruments at his disposal, on behalf of Albania’s progress towards full accession in the European Union.

  1. Centre of the European gas market. The European Autumn Gas Conference

    International Nuclear Information System (INIS)

    Van Hasselt, F.; Van der Wal, W.; Ruinen, H.

    1998-01-01

    From the results of the 1997 European Autumn Gas Conference in Barcelona, Spain, it appears that the European gas industry is mainly focused on the liberalization of the European energy market. The main topic of the Conference was 'dealing with surplus'. A brief overview is given of the natural gas trade developments in the European countries. 1 ill., 1 tab. 2 ills

  2. European Community.

    Science.gov (United States)

    1987-05-01

    The European Community was established in 1951 to reconcile France and Germany after World War II and to make possible the eventual federation of Europe. By 1986, there were 12 member countries: France, Italy, Belgium, the Federal Republic of Germany, Luxembourg, the Netherlands, Denmark, Ireland, the United Kingdom, Greece, Spain, and Portugal. Principal areas of concern are internal and external trade, agriculture, monetary coordination, fisheries, common industrial and commercial policies, assistance, science and research, and common social and regional policies. The European Community has a budget of US$34.035 billion/year, funded by customs duties and 1.4% of each member's value-added tax. The treaties establishing the European Community call for members to form a common market, a common customs tariff, and common agricultural, transport, economic, and nuclear policies. Major European Community institutions include the Commission, Council of Ministers, European Parliament, Court of Justice, and Economic and Social Committee. The Community is the world's largest trading unit, accounting for 15% of world trade. The 2 main goals of the Community's industrial policy are to create an open internal market and to promote technological innovation in order to improve international competitiveness. The European Community aims to contribute to the economic and social development of Third World countries as well.

  3. Raising European Citizens: Constructing European Identities in French and English Textbooks

    Directory of Open Access Journals (Sweden)

    Inari Sakki

    2016-06-01

    Full Text Available Schools play a pivotal role in the formation of identities and in the political socialization of youth. This study explores the social representations of European integration in French and English school textbooks and shows how the social representations are discursively used to construct national and European identities. By analysing the history and civics textbooks of major educational publishers, this study aims to demonstrate how European integration is understood, made familiar and concretized in the school textbooks of the two influential but different European countries. The findings suggest some shared and some diverse patterns in the way the two European countries portray and construct the political project of European integration. These representations, constructed around French Europe in French textbooks and ambivalent Europe in English textbooks, share the images of a strong European economy and a French-led political Europe. However, they position themselves differently with respect to the United States, motivation for the European unification process and the significance of common values and heritage. In both countries textbooks draw upon memories that are important for group identity. While the French textbooks make European integration meaningful in reference to a shared post-war collective memory and to a cultural memory based on a more ancient idea of Europe, shared values and heritage, the English textbooks anchor it more strongly to domestic policy.

  4. Globalization and Europeanization. A Projection on a European Model of Public Administration

    Directory of Open Access Journals (Sweden)

    Ani Matei

    2008-04-01

    Full Text Available The specialized studies and literature present moreover and insistently the connection between globalization and Europeanization, more precisely between globalization and a European model of integration, whose features aim to set up a global-type European society. The development of the European model of integration starts with economic elements, it reveals nowadays the Economic and Monetary Union and in perspective it will be structured within a sui generis system of transnational governance. The values of the European model of integration become fundamental values of a social process, with powerful economic and political determinations, aiming the multi-causal interference between individual, community and European construction. This process, remarked increasingly in the specialized literature, being assigned with the name of Europeanization, has got original, functional features in the spectrum of significations of the globalization paradigm. As essential global-type formula, within Europeanization, we shall find models with economic, political or social finality, integrating also a model of administration among the latter ones. When we say administration, we refer to its up dated and adequate contents to the new European developments. This assertion derives from a less economic modality to conceptualize the relationship between globalization and Europeanization, presenting Europeanization more as a political adaptation to globalization and even a political expression of globalization. In this context, the development of a system for European governance on several levels (local, regional, national, intergovernmental and supranational suggests its evolution towards globalization. In fact, the literature specific for Europeanization asserts the fact that the European model has also features with integrative nature related to the supranational and trans-governmental dimensions, as well as features with normative nature in view of harmonization

  5. Morphometric relations in the grey eel catfish Plotosus canius in the coastal waters of Port Dickson, Peninsular Malaysia.

    Science.gov (United States)

    Usman, B I; Amin, S M N; Arshad, A; Kamarudin, M S

    2016-07-01

    Samples of grey eel catfish Plotosus canius were collected from the coastal waters of Port Dickson, Malaysia from January to December, 2012. A total of 341 specimens (172 males and 169 females) were used to estimate the length-weight relationship parameters. Mean population size of females were 0.72 cm taller than the males, however difference was not significant (t-test, P > 0.05). The overall relationship equations between total length (TL) and body weight (BW) were established for males as Log TW = 2.71 Log TL - 1.85 (R2 = 0.95) and for females as Log TW = 2.88 Log TL-2.10 (R2 = 0.95). The estimated relative growth co-efficient (b) values were 2.71 for males and 2.88 for females. It is revealed that growth pattern of the species showed negative allometry. In both males and females, relationship between TL and SL gave highest regression coefficient (0.99). While relationship between TL and EL gave lowest regression coefficient in both males and females (0.87 and 0.81 respectively). The findings from this study contributed first information on morphometric relations of the fish from Malaysian coastal waters and could be useful for sustainable management options of P. canius in Malaysia.

  6. European Union

    International Nuclear Information System (INIS)

    Schaller, K.

    1995-01-01

    Different instruments used by European Commission of the European Union for financial support radioactive waste management activities in the Russian Federation are outlined. Three particular programmes in the area are described

  7. European Union response to Fukushima. European stress tests and peer review

    Energy Technology Data Exchange (ETDEWEB)

    Jamet, Philippe [Autorite de Surete Nucleaire (ASN), Paris (France)

    2012-07-01

    Following the severe accidents which started in the Fukushima Dai-ichi NPP on 11 March 2011, the European Council requested that a comprehensive safety and risk assessment, in light of preliminary lessons learned, be performed on all EU nuclear plants. Therefore, stress tests and peer review assessing natural initiating events, the loss of safety systems and severe accident management have been performed in the 15 European Union countries with nuclear power plants as well as Switzerland and Ukraine. The final peer review report of the European Nuclear Safety Regulators Group (ENSREG) highlights four main areas for improvement to be explored across Europe: 1. Development by the Western European Nuclear Regulators' Association (WENRA), with the contribution of the best available EU expertise, of a European guidance on assessment of natural hazards and margins; 2. Importance of Periodic Safety Review to be underlined by ENSREG; 3. Expeditious implementation of the recognised measures to protect containment integrity; 4. Prevention of accidents resulting from natural hazards and limitation of their consequences. The peer review of the European stress tests was completed in April 2012. In their conclusive statement issued 26 April 2012, the national European regulators and the European Commission as European Nuclear Safety Regulators Group (ENSREG) required that follow-up would occur by way of an ENSREG action plan. Country specific action plans will be developed and peer review workshop will be organised to share lessons learned on the implementation of post-Fukushima safety improvements.

  8. European Union response to Fukushima. European stress tests and peer review

    International Nuclear Information System (INIS)

    Jamet, Philippe

    2012-01-01

    Following the severe accidents which started in the Fukushima Dai-ichi NPP on 11 March 2011, the European Council requested that a comprehensive safety and risk assessment, in light of preliminary lessons learned, be performed on all EU nuclear plants. Therefore, stress tests and peer review assessing natural initiating events, the loss of safety systems and severe accident management have been performed in the 15 European Union countries with nuclear power plants as well as Switzerland and Ukraine. The final peer review report of the European Nuclear Safety Regulators Group (ENSREG) highlights four main areas for improvement to be explored across Europe: 1. Development by the Western European Nuclear Regulators' Association (WENRA), with the contribution of the best available EU expertise, of a European guidance on assessment of natural hazards and margins; 2. Importance of Periodic Safety Review to be underlined by ENSREG; 3. Expeditious implementation of the recognised measures to protect containment integrity; 4. Prevention of accidents resulting from natural hazards and limitation of their consequences. The peer review of the European stress tests was completed in April 2012. In their conclusive statement issued 26 April 2012, the national European regulators and the European Commission as European Nuclear Safety Regulators Group (ENSREG) required that follow-up would occur by way of an ENSREG action plan. Country specific action plans will be developed and peer review workshop will be organised to share lessons learned on the implementation of post-Fukushima safety improvements.

  9. European visit

    CERN Multimedia

    2006-01-01

    The European Commissioner for Science and Research, Janez Potočnik, (on the right) visited the CMS assembly hall accompanied by Jim Virdee, Deputy Spokesman of CMS (on the left), and Robert Aymar, Director-General of CERN. The European Commissioner for Science and Research, Janez Potočnik, visited CERN on Tuesday 31 January. He was welcomed by the Director-General, Robert Aymar, who described the missions and current activities of CERN to him, in particular the realisation of the LHC with its three components: accelerator, detectors, storage and processing of data. The European Commissioner then visited the CMS assembly hall, then the hall for testing the LHC magnets and the ATLAS cavern. During this first visit since his appointment at the end of 2004, Janez Potočnik appeared very interested by the operation of CERN, an example of successful scientific co-operation on a European scale. The many projects (30 on average) that CERN and the European Commission carry out jointly for the benefit of res...

  10. Europeanization by it is tools: the case of European transnational projects

    NARCIS (Netherlands)

    Sanchez Salgado, R.

    2010-01-01

    In the understanding of Europeanization, specific tools of governance matter. Europeanization through flexible tools of governance enables strategic uses by domestic actors, and does not necessaritly preclude policy transfer or transformation. As long as they favour participation, European

  11. Europeanization and social movement mobilization during the European sovereign debt crisis

    DEFF Research Database (Denmark)

    Bourne, Angela; Chatzopoulou, Sevasti

    2015-01-01

    The article addresses Europeanization of social movements in the context of the European Sovereign Debt Crisis. Europeanization occurs when movements collaborate, or make horizontal communicative linkages with movements in other countries, contest authorities beyond the state, frame issues...

  12. Dysomma alticorpus, a new species of cutthroat eel from the Gulf of Aqaba, Red Sea (Teleostei: Synaphobranchidae).

    Science.gov (United States)

    Fricke, Ronald; Golani, Daniel; Appelbaum-Golani, Brenda; Zajonz, Uwe

    2018-02-01

    The cutthroat eel Dysomma alticorpus n. sp. is described based on a single specimen collected in a trammel net at a depth of 350m off Eilat, Israel, Gulf of Aqaba, Red Sea. The new species belongs to the Dysomma anguillare species complex, which comprises species possessing a well-developed pectoral fin, intermaxillary teeth, a uniserial row of 7-15 large compound teeth in the lower jaw (which may be followed by a few smaller teeth), and an anteriorly situated anus with the trunk shorter than the head length. It is characterised by a combination of the following characters: origin of the dorsal fin well anterior to the base of the pectoral fin, predorsal length 13.8% TL; preanal length 22.8% TL; three compound teeth on the vomer; head pores: IO 4, SO 3; M 6; POP 0; AD 1, F 0, ST 0; lateral-line pores: predorsal 4, prepectoral 8, preanal 14, total 57-58, the last at the posterior two-thirds of the total length; MVF 7-16-115; total vertebrae 115. Dysomma alticorpus n. sp. is compared with other species of the genus. A revised key to the species of the genera Dysomma and Dysommina is provided. Copyright © 2018 Académie des sciences. Published by Elsevier Masson SAS. All rights reserved.

  13. EELS data acquisition, processing and display for the Zeiss CEM 902 based on LOTUS 1-2-3: application examples from a biological system and inorganic transition metal compounds.

    Science.gov (United States)

    Drechsler, M; Cantow, H J

    1991-04-01

    A personal computer combined with LOTUS 1-2-3 software, including the RS232 module of LOTUS MEASURE and a 12-bit ADC, has been used for data acquisition of electron energy-loss spectroscopy (EELS) spectra with the Zeiss CEM 902. The internal macro language of LOTUS 1-2-3 allows a menu-driven procedure. Macro-programs partly combined with external FORTRAN programs can be chosen from the menu for background subtraction, removal of multiple scattering effects by deconvolution, elemental quantification and several utilities. For special applications or conditions the macro programs can easily be modified. Spectra from crystals of two inorganic transition metal compounds, ruthenium trichloride and vanadium disulphide, and from a biological sample are presented as examples of the application of this software.

  14. European mobility cultures

    DEFF Research Database (Denmark)

    Haustein, Sonja; Nielsen, Thomas A. Sick

    2016-01-01

    More targeted European policies promoting green travel patterns require better knowledge on differing mobility cultures across European regions. As a basis for this, we clustered the EU population into eight mobility styles based on Eurobarometer data. The mobility styles - including, for example...... positions on the path towards sustainable mobility and therefore different requirements towards European platforms and support measures, e.g. for 'Sustainable Urban Mobility Plans'. The country clusters can provide a starting point for future communication and targeting of European efforts in sustainable...

  15. Diet of non-native northern snakehead (Channa argus) compared to three co-occurring predators in the lower Potomac River, USA

    Science.gov (United States)

    Ryan K. Saylor,; Nicolas W.R. Laointe,; Angermeier, Paul

    2012-01-01

    Introductions of large, non-native, carnivorous fishes continue to occur worldwide and represent a substantial management concern to global biodiversity. One of the most recent non-native fishes to successfully establish in North America is the northern snakehead (Channa argus), found in the lower Potomac River catchment. Dispersal of the northern snakehead throughout this system has been well documented since its original discovery in May 2004; however, little is known about the foraging habits of this species and its interactions with co-occurring predators. Here, we quantify northern snakehead diet in comparison with the diets of naturalised largemouth bass (Micropterus salmoides), and native American eel (Anguilla rostrata) and yellow perch (Perca flavescens) collected from tidal freshwaters bordering Virginia and Maryland near Fort Belvoir, Virginia. Over 97% of northern snakehead gut contents were fishes, with fundulid and centrarchid species consumed most frequently. Dietary overlap was biologically significant only between northern snakehead and largemouth bass. Aquatic invertebrates were >10 times more common in native predator diets, reducing dietary overlap with northern snakehead. Ontogenic shifts in adult northern snakehead diet were also detected, which may be explained by optimal foraging rather than true prey specificity. Northern snakehead may be occupying a novel niche based on a piscivorous diet, therefore limiting competition with resident predators in the lower Potomac River. Further research into interactions between largemouth bass and northern snakehead is needed to inform management decisions and understand the ecological impacts of this non-native species.

  16. A European legal method? On European private law and scientific method

    NARCIS (Netherlands)

    Hesselink, M.

    2009-01-01

    This article examines the relationship between European private law and scientific method. It argues that a European legal method is a good idea. Not primarily because it will make European private law scholarship look more scientific, but because a debate on the method of a normative science

  17. Selective Europeanization

    DEFF Research Database (Denmark)

    Hoch Jovanovic, Tamara; Lynggaard, Kennet

    2014-01-01

    and rules. The article examines the reasons for both resistance and selectiveness to Europeanization of the Danish minority policy through a “path dependency” perspective accentuating decision makers’ reluctance to deviate from existing institutional commitments, even in subsequently significantly altered...... political contexts at the European level. We further show how the “translation” of international norms to a domestic context has worked to reinforce the original institutional setup, dating back to the mid-1950s. The translation of European-level minority policy developed in the 1990s and 2000s works most...

  18. Are we Europeans?: Correlates and the relation between national and European identity

    Directory of Open Access Journals (Sweden)

    Mihić Vladimir

    2009-01-01

    Full Text Available Researches of the correlates of the national identity are plentiful both in Serbian and foreign literature. However, in the past decade or so, a new social identity starts to make its way into the researches of the social psychologists-European identity or the sense of belonging to the Europe and the Europeans. This paper deals with the relation between national and European identity, as well as with the correlates of both of these, or one of them. The sample consisted of 451 subjects, all residents of major cities in the Vojvodina region (northern Serbia, divided into several categories-ethnicity (Serbs and Hungarians, educational level (primary and secondary school or University degree, gender and age. Several scales have been used: Cinnirela's national and European identity scale, Collective self-esteem scale, scale measuring attitudes towards the European integration-STEIN and Social dominance orientation scale-SDO. The questionnaire with the demographic characteristics has also been the part of the instrument. The research has been conducted in 2005 and 2006 in the all of the major Vojvodinian cities. Results show the relation between national and European identity is foggy, but general conclusion is that we can observe them as independent identities. The correlates of the national identity were ethnicity, high social dominance orientation, high collective self-esteem and negative attitude towards the European integrations. Correlates of the European identity were fewer: ethnicity, positive attitude towards the European integration and low social dominance orientation.

  19. Trans-European transport networks and urban systems in European Union

    OpenAIRE

    Maksin-Mićić Marija

    2003-01-01

    The trans-European transport network has different effects at interregional macro-regional and mezzo-regional level, and its effectiveness rises at the lower regional levels. Possible approaches to the trans-European transport network impact and effect survey and policy options have been pointed out. In that respect the brief review of survies, strategic framework and policies in European Union has been given. The importance of increased accessibility and mobility for regional expansion and f...

  20. The Europeanization of Welfare - The Domestic Impact of Intra-European Social Security

    DEFF Research Database (Denmark)

    Martinsen, Dorte Sindbjerg

    2005-01-01

    Studies of Europeanization have demonstrated that the impact of European integration differs between Member States and across policies. Although Europeanization research has been expanded and clarified in recent years, we still know relatively little about the factors mediating the national...... responses to integration. It is argued that these intervening variables are decisive for how common European demands are mediated nationally and are likely to explain impact variations referring to the same cause....

  1. The european hematology association roadmap for european hematology research : A consensus document

    NARCIS (Netherlands)

    A. Engert (Andreas); C.L. Balduini (Carlo); A. Brand (Anneke); B. Coiffier (Bertrand); C. Cordonnier (Charlotte); H. Döhner (Hartmut); De Wit, T.D. (Thom Duyvené); Eichinger, S. (Sabine); W.E. Fibbe (Willem); Green, T. (Tony); De Haas, F. (Fleur); A. Iolascon (Achille); T. Jaffredo (Thierry); F. Rodeghiero (Francesco); G. Salles (Gilles); J.J. Schuringa (Jan Jacob)

    2016-01-01

    textabstractThe European Hematology Association (EHA) Roadmap for European Hematology Research highlights major achievements in diagnosis and treatment of blood disorders and identifies the greatest unmet clinical and scientific needs in those areas to enable better funded, more focused European

  2. The European Hematology Association Roadmap for European Hematology Research : A consensus document

    NARCIS (Netherlands)

    Engert, Andreas; Balduini, Carlo; Brand, Anneke; Coiffier, Bertrand; Cordonnier, Catherine; Döhner, Hartmut; de Wit, Thom Duyvené; Eichinger, Sabine; Fibbe, Willem; Green, Tony; de Haas, Fleur; Iolascon, Achille; Jaffredo, Thierry; Rodeghiero, Francesco; Salles, Gilles; Schuringa, Jan Jacob

    The European Hematology Association (EHA) Roadmap for European Hematology Research highlights major achievements in diagnosis and treatment of blood disorders and identifies the greatest unmet clinical and scientific needs in those areas to enable better funded, more focused European hematology

  3. The European standard series in 9 European countries, 2002/2003 - First results of the European Surveillance System on Contact Allergies

    NARCIS (Netherlands)

    Uter, W; Hegewald, J; Aberer, W; Ayala, F; Bircher, AJ; Brasch, J; Coenraads, PJ; Schuttelaar, Marielouise; Elsner, P; Fartasch, M; Mahler, V.; Fortina, AB; Frosch, PJ; Fuchs, T; Johansen, JD; Menne, T; Jolanki, R; Krecisz, B; Kiec-Swierczynska, M; Larese, F; Orton, D; Peserico, A; Rantanen, T; Schnuch, A

    Since January 2001, the European Surveillance System on Contact Allergies (ESSCA), supported by European Union funding (contract QLK4-CT-2001-00343), has started to collect patch-test data. This comprises a standardized clinical history and the patch-test results using the European standard series,

  4. European Whiteness?

    DEFF Research Database (Denmark)

    Blaagaard, Bolette

    2008-01-01

    Born out of the United States’ (U.S.) history of slavery and segregation and intertwined with gender studies and feminism, the field of critical whiteness studies does not fit easily into a European setting and the particular historical context that entails. In order for a field of European...

  5. Comparative cytogenetics of six Indo-Pacific moray eels (Anguilliformes: Muraenidae) by chromosomal banding and fluorescence in situ hybridization.

    Science.gov (United States)

    Coluccia, E; Deidda, F; Cannas, R; Lobina, C; Cuccu, D; Deiana, A M; Salvadori, S

    2015-09-01

    A comparative cytogenetic analysis, using both conventional staining techniques and fluorescence in situ hybridization, of six Indo-Pacific moray eels from three different genera (Gymnothorax fimbriatus, Gymnothorax flavimarginatus, Gymnothorax javanicus, Gymnothorax undulatus, Echidna nebulosa and Gymnomuraena zebra), was carried out to investigate the chromosomal differentiation in the family Muraenidae. Four species displayed a diploid chromosome number 2n = 42, which is common among the Muraenidae. Two other species, G. javanicus and G. flavimarginatus, were characterized by different chromosome numbers (2n = 40 and 2n = 36). For most species, a large amount of constitutive heterochromatin was detected in the chromosomes, with species-specific C-banding patterns that enabled pairing of the homologous chromosomes. In all species, the major ribosomal genes were localized in the guanine-cytosine-rich region of one chromosome pair, but in different chromosomal locations. The (TTAGGG)n telomeric sequences were mapped onto chromosomal ends in all muraenid species studied. The comparison of the results derived from this study with those available in the literature confirms a substantial conservation of the diploid chromosome number in the Muraenidae and supports the hypothesis that rearrangements have occurred that have diversified their karyotypes. Furthermore, the finding of two species with different diploid chromosome numbers suggests that additional chromosomal rearrangements, such as Robertsonian fusions, have occurred in the karyotype evolution of the Muraenidae. © 2015 The Fisheries Society of the British Isles.

  6. Political dimension of European constitutionalism

    Directory of Open Access Journals (Sweden)

    Kaplánová Patricia

    2015-04-01

    Full Text Available Author in the article tries to analyse different elements of document called European Constitution. Analysis is supported with theoretical framework of federalism, presented by Brezovšek. Authors is playing with idea of (confederal and international organization elements of European Constitution and their mix. They are also trying to set some connections between so called common European identity as necessary condition to give legitimacy to the European Constitution. This became important question after „votes of non-confidence“ to the European Constitution in France, despite it should be addressed already before. However, European Constitution is important document on the path of European integration and lack of support to it will slow down this process of widening and deepening European ties.

  7. Can the European Central Bank Create a European identity?

    DEFF Research Database (Denmark)

    Ravn Sørensen, Anders

    2014-01-01

    In what ways do central banks construct community, and how may the European Central Bank (ECB) contribute to a supranational European identity? In this paper I seek to answer these two questions by developing a conceptual framework for the ways that central banks construct national identities and...

  8. European citizenship and the constitutionalisation of the European Union

    NARCIS (Netherlands)

    van Eijken, Hanneke|info:eu-repo/dai/nl/314133992

    2014-01-01

    The concept of citizenship in relatively new legal order of the European Union has its own meaning and dynamics compared to national citizenship. One of the important questions regarding this transnational form of citizenship is how to place this European citizenship in a constitutional context in

  9. The european passive plant (EPP) design: compliance with the european utilities requirements (EUR)

    International Nuclear Information System (INIS)

    Noviello, L.; Oyarzabal, M.

    1996-01-01

    Back 1986, most of the European firms have participated to the American program called the Advanced Light Water Reactors (ALWR) including the development of the Utilities Requirements as well as four projects as for instance AP600. Later, in the year 1990, seven European firms have begun to develop the European Utilities Requirements. This development is justified by the fact that the lessons learned by the nuclear power plants designs programs of the years 1980 can be incorporated and the European specific conditions can be taken into consideration. Thus, in 1994, eight European firms - Westinghouse and their industrial partners - have decided to launch a multiphase program in order to check the AP600 compliance with the European Utilities Requirements (EUR) and to develop the required alterations. Today, the phase I of the EPP (European Passive Plant) program has been completed. In this phase, the main important objectives have been reached. (O.M.)

  10. European Institutions?

    NARCIS (Netherlands)

    Meacham, Darian

    2016-01-01

    The aim of this article is to sketch a phenomenological theory of political institutions and to apply it to some objections and questions raised by Pierre Manent about the project of the European Union and more specifically the question of “European Construction”, i.e. what is the aim of the

  11. Modern Sedimentation off the Kaoping River, SW Taiwan: A Comparison with Eel River's S2S System

    Science.gov (United States)

    Huh, C.; Lin, H.; Lin, S.

    2006-12-01

    The Kaoping (KP) River in SW Taiwan has a watershed area of 3257 km2 and an annual sediment discharge of 49 MT. Although the sediment yield of the KP River basin (1.5×104 ton km-2 yr^{- 1}) is the 4th highest among Taiwan's catchment basins, it is nearly one order of magnitude higher than that of the Eel River's basin (~1.8×103 ton km-2 yr-1; the highest in the U.S.). The KP canyon extends almost immediately seaward from the river's mouth and terminates in the northwestern corner of the South China Sea. The head of the canyon is characterized by high and steep walls exceeding 600 m. The KP river's source-to-sink system offers a dramatic case of mountainous rivers at active margins for S2S study. Here we report some results about modern sedimentation in KP river's dispersal system. Seventy-six sediment cores collected from an area of ~3000 km2 were analyzed for fallout nuclides 7Be, 137Cs and 210Pb by gamma spectrometry. From profiles of excess 210Pb and 137Cs sediment accumulation rates in the coring sites were estimated, which vary from 0.06 to 1.6 cm/yr, with the highest rates (>1 cm/yr) distributed in the upper slope (exported out of the study area via the KP canyon to the deep sea by gravity-driven turbidity or hyperpycnal flows.

  12. European Identity and European Citizenship: the Case of Missing Polis?

    Czech Academy of Sciences Publication Activity Database

    Šejvl, Michal

    2008-01-01

    Roč. 2, č. 2 (2008), s. 49-56 ISSN 1789-1035 Institutional research plan: CEZ:AV0Z70680506 Keywords : the European integration * law of citizenship * European identity Subject RIV: AG - Legal Sciences

  13. The European Gonococcal Antimicrobial Surveillance Programme (Euro-GASP)--a sentinel approach in the European Union (EU)/European Economic Area (EEA).

    Science.gov (United States)

    Spiteri, Gianfranco; Cole, Michelle; Unemo, Magnus; Hoffmann, Steen; Ison, Catherine; van de Laar, Marita

    2013-12-01

    Antimicrobial resistance in Neisseria gonorrhoeae is monitored in the European Union/European Economic Area through the European Gonococcal Antimicrobial Surveillance Programme (Euro-GASP) coordinated by the European Centre for Disease Prevention and Control. Euro-GASP includes a sentinel surveillance programme which aims to detect in a timely manner changes in resistance patterns and inform treatment guidelines. The programme aims to test a representative number of isolates from each European Union/European Economic Area member state per year for a range of therapeutically relevant antimicrobials through a biannual hybrid centralised/decentralised system. Testing is supported by an External Quality Assurance programme and a laboratory training programme. Participation in the programme has increased to 21 countries in 2012. Euro-GASP has been able to detect the rapid spread of isolates with decreased susceptibility to cefixime across Europe in 2010 and 2011. Results from the programme have informed changes in European treatment guidelines for gonorrhoea and led to the development of the 'Response plan to control and manage the threat of multidrug resistant gonorrhoea in Europe'. Future challenges for Euro-GASP include supporting countries to participate in Euro-GASP through decentralised testing, improving timeliness and epidemiological data quality, and increasing participation from Eastern Europe.

  14. A European Research Area

    International Nuclear Information System (INIS)

    Caro, R.

    2001-01-01

    This article is a summary of the presentation of the European Commissioner, Philippe Busquen, to the European Parliament (beginning of year 2000) with the proposal and method for a revival of the Research and Development in this wider sense in the European Union. The starting point of his thesis is that Europe performs less, and more disorderly, activities in this field that her main competitors. USA and Japan. His basic proposal is a larger coordination among the european research projects, with a previous phase of informatics intoxicator among the european research centres and the cross-linked participation, real of virtual in the experiments and projects. (Author)

  15. Changes in the lipid fraction of eel gills after ionizing irradiation in vivo and a shift from fresh to sea water

    International Nuclear Information System (INIS)

    Hansen, H.J.M.

    1975-01-01

    Sixteen eels were adapted to tap water for a week. Then eight of them were irradiated with 1000 R γ radiation and four of the irradiated group and four of the nonirradiated control group were transferred to seawater. The rest remained in tap water. Three days later all were incubated with 14 C-labeled acetate and 32 P-labeled phosphate added to the water in the aquariums. Lipids from the gills were separated by tlc and the individual fatty acids were assayed by paper chromatography. Results showed an enhanced incorporation of 14 C activity into sterol esters in seawater. This was further intensified by γ irradiation. Similarly, γ irradiation intensified a relatively enhanced incorporation in seawater of 32 P activity into lecithin, and there was a relatively increased synthesis of certain 14 C-labeled unsaturated fatty acids (mainly C 16 : 1 ) in the gills of animals that had both been irradiated and transferred to seawater. By measuring lipid biosynthesis in gill tissue it was thus possible to show an interaction between the effect of ionizing irradiation and the salinity of the environment, in agreement with previous biological findings. (U.S.)

  16. The European Location Framework - from National to European

    Science.gov (United States)

    Pauknerova, E.; Sidlichovsky, P.; Urbanas, S.; Med, M.

    2016-06-01

    The European Location Framework (ELF) means a technical infrastructure which will deliver authoritative, interoperable geospatial reference data from all over Europe for analysing and understanding information connected to places and features. The ELF has been developed and set up through the ELF Project, which has been realized by a consortium of partners (public, private and academic organisations) since March 2013. Their number increased from thirty to forty in the year 2016, together with a project extension from 36 to 44 months. The project is co-funded by the European Commission's Competitiveness and Innovation Framework Programme (CIP) and will end in October 2016. In broad terms, the ELF Project will deliver a unique gateway to the authoritative reference geospatial information for Europe (harmonised pan-European maps, geographic and land information) sourced from the National Mapping and Cadastral Authorities (NMCAs) around Europe and including transparent licensing. This will be provided as an online ELF web service that will deliver an up-to-date topographic base map and also as view & download services for access to the ELF datasets. To develop and build up the ELF, NMCAs are accompanied and collaborate with several research & academia institutes, a standardisation body, system integrators, software developers and application providers. The harmonisation is in progress developing and triggering a number of geo-tools like edge-matching, generalisation, transformation and others. ELF will provide also some centralised tools like Geo Locator for searching location based on geographical names, addresses and administrative units, and GeoProduct Finder for discovering the available web-services and licensing them. ELF combines national reference geo-information through the ELF platform. ELF web services will be offered to users and application developers through open source (OSKARI) and proprietary (ArcGIS Online) cloud platforms. Recently, 29 NMCAs plus the

  17. THE MANIFESTATION OF THE EUROPEAN CENTRAL BANK’S LEGAL PERSONALITY AT NATIONAL, EUROPEAN AND INTERNATIONAL LEVEL

    Directory of Open Access Journals (Sweden)

    MONICA ŞAGUNA

    2012-05-01

    Full Text Available The European Central Bank is one of the world’ s most important central banks, responsible for the monetary policy covering the 17 member States of the Eurozone. Established by the European Union in 1998, it was given the exclusive right to authorize the issue of banknotes within the European Union. The European Central Bank has legal personality under public international law. As article 282, paragraph 3 of the Treaty on functioning of the European Union and article 9, paragraph 1 of the Statute of the European System of Central Banks and of the European Central Bank states, the European Central Bank and the National Central Banks enjoy their own legal personality. The European Central Bank, given its important role in the economic integration, is the single institution of the European Union which has legal personality. This is a premise for it to fulfill its objectives. In this framework, the purpose of my paper is to analyze the effects of the European Central Bank’s legal personality from a complete perspective: at national, European and international level. Therefore the objectives of my study are: an introspection in the concept of legal personality, the identification of the reason why it was entrusted to a single institution of the European Union and a detailed analyze of the effects of the European Central Bank’ s legal personality.

  18. A field survey of metal binding to metallothionein and other cytosolic ligands in liver of eels using an on-line isotope dilution method in combination with size exclusion (SE) high pressure liquid chromatography (HPLC) coupled to Inductively Coupled Plasma time-of-flight Mass Spectrometry (ICP-TOFMS).

    Science.gov (United States)

    Van Campenhout, Karen; Goenaga Infante, Heidi; Goemans, Geert; Belpaire, Claude; Adams, Freddy; Blust, Ronny; Bervoets, Lieven

    2008-05-15

    The effect of metal exposure on the accumulation and cytosolic speciation of metals in livers of wild populations of European eel with special emphasis on metallothioneins (MT) was studied. Four sampling sites in Flanders showing different degrees of heavy metal contamination were selected for this purpose. An on-line isotope dilution method in combination with size exclusion (SE) high pressure liquid chromatography (HPLC) coupled to Inductively Coupled Plasma time-of-flight Mass Spectrometry (ICP-TOFMS) was used to study the cytosolic speciation of the metals. The distribution of the metals Cd, Cu, Ni, Pb and Zn among cytosolic fractions displayed strong differences. The cytosolic concentration of Cd, Ni and Pb increased proportionally with the total liver levels. However, the cytosolic concentrations of Cu and Zn only increased above a certain liver tissue threshold level. Cd, Cu and Zn, but not Pb and Ni, were largely associated with the MT pool in correspondence with the environmental exposure and liver tissue concentrations. Most of the Pb and Ni and a considerable fraction of Cu and Zn, but not Cd, were associated to High Molecular Weight (HMW) fractions. The relative importance of the Cu and Zn in the HMW fraction decreased with increasing contamination levels while the MT pool became progressively more important. The close relationship between the cytosolic metal load and the total MT levels or the metals bound on the MT pool indicates that the metals, rather than other stress factors, are the major factor determining MT induction.

  19. Principles of European Contract Law

    DEFF Research Database (Denmark)

    Lando, Ole; Beale, Hugh

    This text provides a comprehensive guide to the principles of European contract law. They have been drawn up by an independent body of experts from each Member State of the EU, under a project supported by the European Commission and many other organizations. The principles are stated in the form...... of articles, with a detailed commentary explaining the purpose and operation of each article and its relation to the remainder. Each article also has extensive comparative notes surveying the national laws and other international provisions on the topic. "The Principles of European Contract Law Parts I &...... in developing a common European legal culture. The European Parliament has twice called for the creation of a European Civil Code. The principles of European contract law are essential steps in these projects. This text provides a comprehensive guide to the Principles of European contract law. They have been...

  20. European Vegetation Archive (EVA)

    NARCIS (Netherlands)

    Chytrý, Milan; Hennekens, S.M.; Jiménez-Alfaro, Borja; Schaminée, J.H.J.; Haveman, Rense; Janssen, J.A.M.

    2016-01-01

    The European Vegetation Archive (EVA) is a centralized database of European vegetation plots developed by the IAVS Working Group European Vegetation Survey. It has been in development since 2012 and first made available for use in research projects in 2014. It stores copies of national and