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Sample records for goby pomatoschistus marmoratus

  1. Genetic architecture of the marbled goby Pomatoschistus marmoratus (Perciformes, Gobiidae) in the Mediterranean Sea.

    Science.gov (United States)

    Mejri, Randa; Arculeo, Marco; Hassine, Oum Kalthoum Ben; Brutto, Sabrina Lo

    2011-02-01

    The marbled goby Pomatoschistus marmoratus, a species inhabiting coastal Mediterranean lagoons, has been studied by measuring its mitochondrial DNA variation. This analysis revealed a Mediterranean west vs east split and, subsequently, an eastern differentiation among the Libyan-Tunisian Gulf, the Adriatic Sea and the Aegean Sea. The high cohesion between the samples collected in the vast area of western Mediterranean contrasts with the genetic mosaic of the more sub-structured eastern Mediterranean. This western homogeneity can not yet be fully explained even if a human-mediated migratory flow, due to a maritime traffic, has been posited. The pattern in the eastern basin revealed a genetic architecture possibly due to the non-migratory habit of the gobid. Within this perspective, the role of the Mediterranean lagoon habitat should be related to how much it amplifies the effects of historical (e.g. past sea-level changes) and environmental (e.g. present-day hydrographic regime) processes as regards the genetic structure of the inhabiting species. Copyright © 2010 Elsevier Inc. All rights reserved.

  2. Environmental variables, habitat discontinuity and life history shaping the genetic structure of Pomatoschistus marmoratus

    Science.gov (United States)

    González-Wangüemert, Mercedes; Vergara-Chen, Carlos

    2014-06-01

    Coastal lagoons are semi-isolated ecosystems exposed to wide fluctuations of environmental conditions and showing habitat fragmentation. These features may play an important role in separating species into different populations, even at small spatial scales. In this study, we evaluate the concordance between mitochondrial (previous published data) and nuclear data analyzing the genetic variability of Pomatoschistus marmoratus in five localities, inside and outside the Mar Menor coastal lagoon (SE Spain) using eight microsatellites. High genetic diversity and similar levels of allele richness were observed across all loci and localities, although significant genic and genotypic differentiation was found between populations inside and outside the lagoon. In contrast to the F ST values obtained from previous mitochondrial DNA analyses (control region), the microsatellite data exhibited significant differentiation among samples inside the Mar Menor and between lagoonal and marine samples. This pattern was corroborated using Cavalli-Sforza genetic distances. The habitat fragmentation inside the coastal lagoon and among lagoon and marine localities could be acting as a barrier to gene flow and contributing to the observed genetic structure. Our results from generalized additive models point a significant link between extreme lagoonal environmental conditions (mainly maximum salinity) and P. marmoratus genetic composition. Thereby, these environmental features could be also acting on genetic structure of coastal lagoon populations of P. marmoratus favoring their genetic divergence. The mating strategy of P. marmoratus could be also influencing our results obtained from mitochondrial and nuclear DNA. Therefore, a special consideration must be done in the selection of the DNA markers depending on the reproductive strategy of the species.

  3. Courtship Sounds Advertise Species Identity and Male Quality in Sympatric Pomatoschistus spp. Gobies

    Science.gov (United States)

    Pedroso, Silvia S.; Barber, Iain; Svensson, Ola; Fonseca, Paulo J.; Amorim, Maria Clara P.

    2013-01-01

    Acoustic signals can encode crucial information about species identity and individual quality. We recorded and compared male courtship drum sounds of the sand goby Pomatoschistus minutus and the painted goby P. pictus and examined if they can function in species recognition within sympatric populations. We also examined which acoustic features are related to male quality and the factors that affect female courtship in the sand goby, to determine whether vocalisations potentially play a role in mate assessment. Drums produced by the painted goby showed significantly higher dominant frequencies, higher sound pulse repetition rates and longer intervals between sounds than those of the sand goby. In the sand goby, male quality was predicted by visual and acoustic courtship signals. Regression analyses showed that sound amplitude was a good predictor of male length, whereas the duration of nest behaviour and active calling rate (i.e. excluding silent periods) were good predictors of male condition factor and fat reserves respectively. In addition, the level of female courtship was predicted by male nest behaviour. The results suggest that the frequency and temporal patterns of sounds can encode species identity, whereas sound amplitude and calling activity reflects male size and fat reserves. Visual courtship duration (nest-related behaviour) also seems relevant to mate choice, since it reflects male condition and is related to female courtship. Our work suggests that acoustic communication can contribute to mate choice in the sand goby group, and invites further study. PMID:23755129

  4. Population genetic diversity of marble goby (Oxyeleotris marmoratus ...

    Indian Academy of Sciences (India)

    Cheng Zhao

    2017-12-08

    Dec 8, 2017 ... east Asia, especially in Malaysia, Singapore, Thailand and. Vietnam (Inger ... cial culture of marble goby has suffered from germplasm ..... Southeast Asia. Through long-term artificial breeding, the genetic diversity of the cultured marble goby popula- tions were relatively low compared to Vietnam population.

  5. Population genetic diversity of marble goby (Oxyeleotris marmoratus ...

    Indian Academy of Sciences (India)

    Navya

    2017-03-31

    Mar 31, 2017 ... Aquaculture in Asia. pp. 237-242. Manila, Philippines. Loo P., Chong C., Ibrahim S. and Sabaratnam V. 2015 Manipulating Culture Conditions and Feed Quality to Increase the Survival of Larval Marble Goby Oxyeleotris marmorata. N. Am. J. Aquacult. 77, 149–159. Luo J., Zhu X., Peng Y. and Yin S. 2013 ...

  6. Population genetic diversity of marble goby (Oxyeleotris marmoratus ...

    Indian Academy of Sciences (India)

    Cheng Zhao

    2017-12-08

    Dec 8, 2017 ... E-mail: yinshaowu@163.com. Cheng Zhao and Xiaoping Zhu contributed equally to this work. Keywords. marble goby; genetic diversity; mtDNA control region; microsatellite; population structure. mtDNA is highly polymorphic and it has 5–10 times rate of nucleotide substitution than nuclear DNA (Aquadro.

  7. A preliminary study on the taste preferences of marble goby (Oxyeleotris marmoratus for amino acids

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    Leong-Seng Lim

    2015-08-01

    Full Text Available Taste preferences of marble goby (Oxyeleotris marmoratus for a mixture and several single L-isomer amino acids were determined through behavioral tests. Agar gel pellet was used as the medium to deliver the amino acids, and the fish acceptance on these pellets was evaluated by calculating the acceptance index (total pellet ingested/total pellet given; maximum and minimum values are 1 and 0, respectively. O. marmoratus were found to moderately accept L-alanine, L-glycine, and L-glutamine (index values 0.38, 0.32, and 0.27, respectively but reject L-cysteine, L-glutamic acid, L-lysine, L-serine and taurine (index value 0. The amino acids mixture (AAM showed the highest acceptance (0.91 by the fish. Such results indicated that the fish preferred the amino acids mixture over any of the single amino acids tested. Therefore, the amino acids mixture is potent to function as the feeding stimulant for the O. marmoratus.

  8. New light on the evolutionary history of the common goby (Pomatoschistus microps with an emphasis on colonization processes in the Mediterranean Sea.

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    Christelle Tougard

    Full Text Available Through the study of the phylogeographic structure and demographic history of the common goby, Pomatoschistus microps, the influence of Quaternary climatic changes on the evolutionary history of coastal and marine fishes is investigated. Because of its sedentary life cycle in Mediterranean lagoons, it is also a good model to study more specifically if the formation of lagoons during the Holocene had an impact on population structure and demography. Mitochondrial sequences of Northeastern Atlantic and Western Mediterranean specimens were used for phylogenetic reconstructions as well as divergence time estimates, demographic history and population structure analyses. Pomatoschistus microps was a highly supported monophyletic clade including four lineages. It may have appeared 77,000 yr ago, and the divergence of its lineages likely occured shortly thereafter (between 61,000 and 54,000 yr. Most lineages had polytomic topologies, low nucleotide diversity and demographic analyses providing evidence of population expansion. Each lineage was characterized by a large number of private haplotypes. Most haplotypes found in Mediterranean localities were endemic, and one was dominant. Complex reticulated relationships connecting North European, Atlantic and Mediterranean haplotypes were observed. Moderate to high population structure was underlined. Contrary to previous published studies, no significant differentiation was observed between Atlantic and Mediterranean populations, indicating that the Gibraltar Strait is not a phylogeographic break for P. microps. Indeed, molecular dating combined with the tree topologies, phylogeographic and demographic analyses as well as high haplotype diversity underline a recent and rapid population divergence during the last glacial. However, population structure indicates that differentiation is an ongoing process. From an ancestral population trapped in the Atlantic, this goby colonized first northern Europe and later

  9. Evaluation on the potential of betaine, taurine, nucleotide and nucleoside as feeding stimulant for juvenile marble goby Oxyeleotris marmoratus through behavioural assays

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    Leong-Seng Lim

    2016-04-01

    Full Text Available Abstract This study was conducted to evaluate the potential of betaine, taurine, inosine (INO, inosine 5′-monophosphate disodium (IMP·Na2, and guanosine 5′-monophosphate disodium (GMP·Na2 as a feeding stimulant for juvenile marble goby (Oxyeleotris marmoratus (total length 6.6–8.5 cm through behavioural assays using agar gel pellets. All fish were conditioned to accept agar gel pellet before the behavioural assays started. Each chemical substance was tested on 50 replicates of individual fish once, and the overall ingestion rate was calculated as the representative data. The pure agar gel pellet was totally rejected by the fish (0 % ingestion rate. Therefore, any added test substance which can significantly improve the fish ingestion of the agar gel pellet can be the potential feeding stimulant. Of all the chemical substances tested at 0.1 M concentration, the ingestion rates of both INO and IMP·Na2 were the highest (both 100 % and were significantly higher (P 0.1 M may be required to improve its efficiency as the feeding stimulant. Taurine was not a feeding stimulant, and betaine was neither a feeding stimulant nor feed enhancer for the juvenile O. marmoratus.

  10. Temperature rise and microplastics interact with the toxicity of the antibiotic cefalexin to juveniles of the common goby (Pomatoschistus microps): Post-exposure predatory behaviour, acetylcholinesterase activity and lipid peroxidation.

    Science.gov (United States)

    Fonte, Elsa; Ferreira, Pedro; Guilhermino, Lúcia

    2016-11-01

    The goal of this study was to investigate the toxicity of cefalexin to Pomatoschistus microps juveniles in relation to the presence of microplastics in the water and temperature rise. After acclimatization, groups of wild juveniles were exposed for 96h to artificial salt water (control), microplastics alone (0.184mg/l), cefalexin alone (1.3-10mg/l) and in mixture with microplastics (cefalexin: 1.3-10mg/l; microplastics: 0.184mg/l) at 20 and 25°C. Effect criteria were mortality, post-exposure predatory performance (PEPP), acetylcholinesterase activity (AChE) and lipid peroxidation levels (LPO). At 20°C, concentrations of cefalexin alone≥5mg/l significantly reduced PEPP (up to 56%; 96h-EC 50 =8.4mg/l), indicating toxicity of the antibiotic to juveniles after short-term exposure to water concentrations in the low ppm range. At 20°C, fish exposed to microplastics alone did not have significant differences in any of the parameters tested relative to the control group but tended to have an inhibition of the PEPP (23%) and AChE (21%); at 25°C, microplastics alone caused mortality (33%) and PEPP inhibition (28%). Thus, microplastics are toxic to P. microps juveniles. At 20°C, under simultaneous exposure to cefalexin and microplastics, the PEPP was significantly reduced (at cefalexin concentrations≥1.25mg/l). Moreover, at 25°C, the toxicity curves of cefalexin (PEPP based), alone and in mixture with microplastics, were significantly different (pmicroplastics in the water influenced the toxicity of cefalexin. The rise of water temperature (from 20°C to 25°C), increased the microplastics-induced mortality (from 8 to 33%), and the inhibitory effects of cefalexin on the PEPP (up to 70%). Significant differences (pmicroplastics and of cefalexin, alone and in mixture with microplastics, to P. microps juveniles. These findings raise concern on the long-term exposure of wild populations to complex mixtures of pollutants, likely decreasing their fitness, and highlight

  11. Population genetic diversity of marble goby (Oxyeleotris marmoratus ...

    Indian Academy of Sciences (India)

    Navya

    2017-03-31

    Mar 31, 2017 ... The numbers of variable sites were 11, 12 and 25 in YS, GS and HS populations, respectively. 91 sequences could be defined as 20 haplotypes based on the ... Institutions (PAPD), China. National Undergraduate Training Program for Innovation and. Entrepreneurship (201610319006). References.

  12. Sexually selected nest-building--Pomatoschistus minutus males build smaller nest-openings in the presence of sneaker males.

    Science.gov (United States)

    Svensson, O; Kvarnemo, C

    2003-09-01

    Both natural selection and sexual selection may act on nest-building. We tested experimentally how different regimes of egg-predation and male-male competition influence nest-building before mating, using the marine fish sand goby, Pomatoschistus minutus. Males with sneaker males present built the smallest nest-openings, smaller than males held alone or with Pomatoschistus microps males (which may predate eggs and compete over nest-sites but not compete over fertilizations). Males with visual access to other nest-building males tended also to build smaller openings than males held alone or with P. microps. Males with egg-predators present built nests with openings not differing significantly from any other treatment. Our results indicate that the small nest-openings found in the sneaker male treatment are sexually selected through protection against sneaking or by female choice. Across treatments, time span before a male started to build his nest also explained variation in nest-opening width; males starting late built larger nest-openings.

  13. EFFECT OF ENVIRONMENTAL FACTORS ON COMPOSITION, NUMBER AND DISTRIBUTION OF GOBIES IN THE WESTERN PART OF THE NORTH CASPIAN SEA

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    G. M. Abdurakhmanov

    2013-01-01

    Full Text Available Abstract. Information about abudance and distribution of 8 species of Caspian gobies (Neogobius melanostomus, Neogobius kessleri, Neogobius syrman eurystomus, Neogobius gymnotrachelus, Neogobius caspius, Proterorhinus marmoratus, Bentophilus sp. is given. A method of trawling (number of gobies / one o'clock trawling was used. Hydrological and hydrochemical changes in the Caspian Sea influence the distribution and abudance of goby fishes in the western part of the North Caspian Sea. Changes of species composition and distribution depended on the lowering in the sea level, increase of salinity, temperaturebackground. The maximal abudance of gobies in 2010 were as in previous years in the highly productive waters (western part, where was the fattening of sturgeons, semi-anadromous and marine fishes. Concentration of gobies is decreased in less trophic waters (eastern part of the Northern Caspian Sea.

  14. Phylogeny of Gobioidei and the origin of European gobies

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    Ainhoa Agorreta

    2015-11-01

    Full Text Available The percomorph order Gobioidei comprises over 2200 species worldwide distributed that occupy most freshwater, brackish and marine environments, and show a spectacular variety in morphology, ecology, and behaviour. However, phylogenetic relationships among many gobioid groups still remain poorly understood. Such is the case of Gobiidae, a rapidly radiating lineage that encompass an unusually high diversity of species (nearly 2000, including the largely endemic European species whose origin and ancestry remain uncertain. The resolution and accuracy of previous molecular phylogenetic studies has been limited due to the use of only a few (generally mitochondrial molecular markers and/or the absence of representatives of several key lineages. Our study (built on Agorreta et al. 2013 is the first to include multiple nuclear and mitochondrial genes for nearly 300 terminal taxa representing the vast diversity of gobioid lineages. We have used this information to reconstruct a robust phylogeny of Gobioidei, and we are now investigating the historical biogeography and diversification times of European gobies with a time-calibrated molecular phylogeny. Robustness of the inferred phylogenetic trees is significantly higher than that of previous studies, hence providing the most compelling molecular phylogenetic hypotheses for Gobioidei thus far. The family Eleotrididae branches off the gobioid tree after the Rhyacichthyidae + Odontobutidae clade followed by the Butidae as the sister-group of the Gobiidae. Several monophyletic groups are identified within the two major Gobiidae subclades, the gobionelline-like and the gobiine-like gobiids. The European gobies cluster in three distinct lineages (Pomatoschistus-, Aphia-, and Gobius-lineages, each with different affinities with gobiids from the Indo-Pacific and perhaps the New World. Our ongoing more-detailed study on European gobies will reveal whether their origin is related to vicariant events linked to the

  15. The ecological role of overwintering fish in the food web of the Culbin Sands lagoon ecosystem, NE Scotland: Identifying major trophic links and testing effects of the fish Pomatoschistus microps (Pallas on benthic invertebrates

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    Vanda Mariyam Mendonça

    2007-12-01

    Full Text Available The Culbin Sands lagoon ecosystem in NE Scotland was studied during a three-year period (1994-1996 to identify the major trophic links from benthic invertebrates to epibenthic predators, and to assess impacts of overwintering fish on their prey communities. Every 2-4 weeks, samples of mobile fauna were collected to study their diets. The major trophic links identified between benthic invertebrates and epibenthic predators were from benthic invertebrates to the shrimp Crangon crangon, and to the common goby Pomatoschistus microps and the plaice Pleuronectes platessa. The energy flow from benthic invertebrates to overwintering fish was estimated at 133 kJ m–2 yr–1. A flow of 10 kJ m–2 yr–1 was also observed from eggs and larval stages of the overwintering shrimp Crangon crangon to the overwintering fish. Nevertheless, manipulative field experiments showed no significant impacts of the most abundant overwintering fish Pomatoschistus microps on prey community densities, despite an overall individual ingestion rate of 89 J day–1.

  16. Manipulation and imaging of Kryptolebias marmoratus embryos.

    Science.gov (United States)

    Mourabit, Sulayman; Kudoh, Tetsuhiro

    2012-12-01

    The self-fertilizing mangrove killifish, Kryptolebias marmoratus, is an upcoming model species for a range of biological disciplines. To further establish this model in the field of developmental biology, we examined several techniques for embryonic manipulation and for imaging that can be used in an array of experimental designs. These methodological approaches can be divided into two categories: handling of embryos with and without their chorionic membrane. Embryos still enclosed in their chorion can be manipulated using an agarose bed or a methyl cellulose system, holding them in place and allowing their rotation to more specific angles and positions. Using these methods, we demonstrate microinjection of embryos and monitoring of fluorescent yolk syncytial nuclei (YSN) using both stereo and compound microscopes. For higher magnification imaging using compound microscopes as well as time-lapse analyses, embryos were dechorionated and embedded in low-melting-point agarose. To demonstrate this embedding technique, we further examined fluorescent YSN and also analyzed the yolk surface of K. marmoratus embryos. The latter was observed to provide an excellent imaging platform for study of the behavior and morphology of cells during embryonic development, for various types of cells. Our data demonstrate that K. marmoratus is an excellent model species for research in developmental biology, as methodological approaches for the manipulation and imaging of embryos are efficient and readily available.

  17. Testicular cell cytoskeleton in the newt, Triturus marmoratus marmoratus, during the annual cycle.

    Science.gov (United States)

    Ramos, P; De Miguel, M P; Arenas, M I; Fraile, B; Paniagua, R

    1996-04-15

    Light and electron microscopy immunohistochemical studies and Western blotting analysis of cytoskeletal proteins have been carried out in the testis of the marbled newt (Triturus marmoratus marmoratus) during the annual testicular cycle. The present findings revealed homologies and differences with regard to those reported in the testes of mammals and other vertebrates. Changes in immunohistochemical expression have also been detected in the course of the annual cycle. Actin and tubulin, which were scanty and diffusely located in spermatogonia and spermatocytes, increased their expression and reorganized during spermiogenesis. Vimentin and keratin, undetected in spermatogonia and spermatocytes, were expressed in differentiating spermatids and spermatozoa. In these cells, actin might be related with the connection of the axial fiber to the undulating membrane and the coordination of movement by both structures, while vimentin might be involved in the maintenance of the spatial relationship between the axoneme and the marginal fiber. During the first stages of spermatogenesis, the cytoplasm of Sertoli cells (follicular cells) showed a diffuse immunoreaction to actin, myosin, and tubulin and no vimentin immunolabeling. In advanced spermiogenesis, the follicular cells showed an intense immunoreaction to actin, myosin, tubulin, and vimentin in the apical projections that surrounded the spermatid heads. These apical cytoskeletal components might be involved in spermatid elongation, since the spermatids display no manchette, and in spermatozoon positioning and grouping. The colocalization of myosin and actin in the follicular cells suggests that actin filaments from contractile bundles and that contraction might be involved in changes in the Sertoli cell shape that accompany germ cell development during spermatogenesis. The interstitial cells immunostained to actin, myosin, tubulin, and vimentin. These cells, together with follicular cells, seemed to form the glandular

  18. An endocrine disrupting chemical changes courtship and parental care in the sand goby

    Energy Technology Data Exchange (ETDEWEB)

    Saaristo, Minna, E-mail: Minna.Saaristo@helsinki.fi [Department of Bio- and Environmental Sciences, University of Helsinki, P.O. Box 65, FI-00014 Helsinki (Finland); Craft, John A. [Biological and Biomedical Sciences, Glasgow Caledonian University, Cowcaddens Road, Glasgow G4 0BA, Scotland (United Kingdom); Lehtonen, Kari K. [Finnish Environment Institute, Marine Research Centre, P.O. Box 140, FI-00251 Helsinki (Finland); Lindstroem, Kai [Environmental and Marine Biology, Abo Akademi University, FI-20520 Turku (Finland)

    2010-05-10

    Endocrine disrupting chemicals (EDCs) are a diverse group of compounds that can mimic, block or modulate the synthesis of natural hormones. They are known to cause impairment of reproduction of aquatic organisms at very low concentrations. The aim of this study was to examine how exposure from 10 to 31 days to 17{alpha}-ethinyl estradiol (EE2, 41 ng L{sup -1}) affects the courtship and parental care behaviour of male sand gobies (Pomatoschistus minutus). The sand goby exhibits a polygynous mating system, where males compete for females and provide paternal care. First, male courtship performance towards a stimulus female was recorded with video camera. Secondly, after the male had received eggs his parental care behaviour was video recorded. In addition to behavioural endpoints, we measured the expression of hepatic vitellogenin (Vtg) and zona radiata protein (Zrp) mRNA, as well as common somatic indices. Our study shows that exposure to EE2 affected male fanning behaviour during both courtship and parental care. Interestingly, small exposed males increased their courtship fanning to similar levels as larger control males. However, during parental care egg fanning was not related to male size, and all exposed males fanned more than control males. The EE2-exposure induced Vtg and Zrp mRNA expression in males and decreased hepatosomatic index (HSI), and increased gonadosomatic index (GSI). Females prefer males that fan more, which will favour the small EDC exposed males. This may lead to mating that favours males that are not strong enough to tend the eggs until they hatch, thus decreasing the reproductive success of individuals.

  19. Fries' goby, a European oddity

    Directory of Open Access Journals (Sweden)

    Peter J Miller

    2015-12-01

    Full Text Available Fries' Goby, Lesueurigobius friesii (Malm, 1874 is common on softer grounds of the more offshore eastern Atlantic continental shelf from Norway to Mauritania, and in the Mediterranean to the Sea of Marmora. The several species of the genus are unique among Lusitanian/Boreal gobiine gobies in coloration and caudal morphology as well as in the 'longitudinal' pattern of infraorbital free neuromast-organs and the lack of head lateral-line canals. A new classification of Old World longitudinal gobiines, based on these free neuromast patterns of both infraorbital and hyomandibular innervation, places Lesueurigobius as the Atlantic sister group to the other longitudinal gobiines, which are all Indo/West Pacific in distribution. The proposed cladogram, the first for the group, is based on synapomorphies in features of rostral mandibular line neuromast series f, the rows of the cheek, and vertebral number. Species of Lesueurigobius show an apparently apomorphic reduction in infraorbital row cp that is shared with three Indo-West Pacific genera (Silhouettea, Heteroplopomus and Platygobiopsis but, in Lesueurigobius , this is now believed to be plesiomorphic. Morphological character states were used to construct a cladogram which was discussed in relation to molecular findings that support Lesueurigobius as an outgroup to the Indo/West Pacific genera. The importance of the latter as tools for testing morphological phylogenies, rather than as conflicting classification, is strongly emphasised.

  20. The Gulf of Guinea goby-shrimp symbiosis and a review of goby-thalassinidean associations

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    Wirtz, P.

    2008-01-01

    Full Text Available An undescribed species of the family Gobiidae shares the burrows of the axiid shrimp Axiopsis serratifrons at São Tomé and Príncipe (central eastern Atlantic. In contrast to similar associations of gobiid fishes with alpheid shrimps in the Indo-Pacific and the western Atlantic (where the goby serves as a sentinel for the crustacean and the shrimp leaves the burrow only if the goby remains at the burrow entrance, the axiid appears to completely ignore the goby, which rests near the opening of the burrow. Facultative and obligatory associations of gobies with thalassinidean shrimps are reviewed.

  1. Use of electrical barriers to deter movement of round goby

    Science.gov (United States)

    Savino, Jacqueline F.; Jude, David J.; Kostich, Melissa J.; Coutant, Charles C.

    2001-01-01

    An electrical barrier was chosen as a possible means to deter movement of round goby Neogobius melanostomus. Feasibility studies in a 2.1-m donut-shaped tank determined the electrical parameters necessary to inhibit round goby from crossing the 1-m stretch of the benthic, electrical barrier. Increasing electrical pulse duration and voltage increased effectiveness of the barrier in deterring round goby movement through the barrier. Differences in activity of round goby during daytime and nocturnal tests did not change the effectiveness of the barrier. In field verification studies, an electrical barrier was placed between two blocking nets in the Shiawassee River, Michigan. The barrier consisted of a 6-m wide canvas on which were laid four cables carrying the electrical current. Seven experiments were conducted, wherein 25 latex paint-marked round goby were introduced upstream of the electrical barrier and recovered 24 h later upstream, on, and downstream of the barrier. During control studies, round goby moved across the barrier within 20 min from release upstream. With the barrier on and using the prescribed electrical settings shown to inhibit passage in the laboratory, the only marked round goby found below the barrier were dead. At reduced pulse durations, a few round goby (mean one/test) were found alive, but debilitated, below the barrier. The electrical barrier could be incorporated as part of a program in reducing movement of adult round goby through artificial connections between watersheds.

  2. Evidence for predatory control of the invasive round goby

    Science.gov (United States)

    Madenjian, C.P.; Stapanian, M.A.; Witzel, L.D.; Einhouse, D.W.; Pothoven, S.A.; Whitford, H.L.

    2011-01-01

    We coupled bioenergetics modeling with bottom trawl survey results to evaluate the capacity of piscivorous fish in eastern Lake Erie to exert predatory control of the invading population of round goby Neogobius melanostomus. In the offshore (>20 m deep) waters of eastern Lake Erie, burbot Lota lota is a native top predator, feeding on a suite of prey fishes. The round goby invaded eastern Lake Erie during the late 1990s, and round goby population size increased dramatically during 1999–2004. According to annual bottom trawl survey results, round goby abundance in offshore waters peaked in 2004, but then declined during 2004–2008. Coincidentally, round goby became an important component of burbot diet beginning in 2003. Using bottom trawling and gill netting, we estimated adult burbot abundance and age structure in eastern Lake Erie during 2007. Diet composition and energy density of eastern Lake Erie burbot were also determined during 2007. This information, along with estimates of burbot growth, burbot mortality, burbot water temperature regime, and energy densities of prey fish from the literature, were incorporated into a bioenergetics model application to estimate annual consumption of round goby by the adult burbot population. Results indicated that the adult burbot population in eastern Lake Erie annually consumed 1,361 metric tons of round goby. Based on the results of bottom trawling, we estimated the biomass of yearling and older round goby in offshore waters eastern Lake Erie during 2007–2008 to be 2,232 metric tons. Thus, the adult burbot population was feeding on round goby at an annual rate equal to 61% of the estimated round goby standing stock. We concluded that the burbot population had high potential to exert predatory control on round goby in offshore waters of eastern Lake Erie.

  3. Downstream drift of round goby (Neogobius melanostomus) and tubenose goby (Proterorhinus semilunaris) in their non-native area

    Czech Academy of Sciences Publication Activity Database

    Janáč, Michal; Šlapanský, Luděk; Valová, Zdenka; Jurajda, Pavel

    2013-01-01

    Roč. 22, č. 3 (2013), s. 430-438 ISSN 0906-6691 R&D Projects: GA ČR(CZ) GAP505/11/1768 Institutional support: RVO:68081766 Keywords : invasive species * dispersal * drift * round goby * tubenose goby * Gobiidae Subject RIV: EH - Ecology, Behaviour Impact factor: 1.590, year: 2013

  4. Pathogenic fungus Batrachochytrium dendrobatidis in marbled water frog Telmatobius marmoratus: first record from Lake Titicaca, Bolivia.

    Science.gov (United States)

    Cossel, John; Lindquist, Erik; Craig, Heather; Luthman, Kyle

    2014-11-13

    The pathogenic fungus Batrachochytrium dendrobatidis (Bd) has been associated with amphibian declines worldwide but has not been well-studied among Critically Endangered amphibian species in Bolivia. We sampled free-living marbled water frogs Telmatobius marmoratus (Anura: Leptodactylidae) from Isla del Sol, Bolivia, for Bd using skin swabs and quantitative polymerase chain reactions. We detected Bd on 44% of T. marmoratus sampled. This is the first record of Bd in amphibians from waters associated with Lake Titicaca, Bolivia. These results further confirm the presence of Bd in Bolivia and substantiate the potential threat of this pathogen to the Critically Endangered, sympatric Titicaca water frog T. culeus and other Andean amphibians.

  5. Phenotypic differences between the sexes in the sexually plastic mangrove rivulus fish (Kryptolebias marmoratus)

    DEFF Research Database (Denmark)

    Garcia, Mark J.; Ferro, Jack M.; Mattox, Tyler

    2016-01-01

    the sexes in a sexchanging vertebrate, the mangrove rivulus fish (Kryptolebias marmoratus), to elucidate potential factors that might drive the ‘decision’ to switch sex. Rivulus populations consist of self-fertilizing hermaphrodites and males. Hermaphrodites transition into males under certain environmental...

  6. First record of Rivulus marmoratus Poey, 1880 From the South American continent (Pisces: Cyprinodontidae)

    NARCIS (Netherlands)

    Taphorn, D.C.

    1980-01-01

    Rivulus marmoratus Poey, 1880 has previously been found only in south Florida, Cuba, the Bahamas, Barbuda, St. Martin and several islands off the Venezuelan coast (Curaçao, Bonaire and Gran Roque) (Hoedeman, 1958; Böhlke & Chaplin, 1968). In September of 1978, one of my students, Mr. Edgard W.

  7. The Use of "Kryptolebias marmoratus" Eggs as an Educational Tool for Embryology Education

    Science.gov (United States)

    Genade, Tyrone

    2016-01-01

    Plastic embryological models lack the excitement of seeing real, live embryos. Chick embryos are often used to demonstrate embryological development and blood circulation to students but this necessitates the death of the organism. "Kryptolebias marmoratus" embryos are large and can be viewed by means of a light microscope without need…

  8. Trichodinid (Ciliophora: Peritrichida Ectoparasites of Sand Goby (Oxyeleotris marmorata Fry

    Directory of Open Access Journals (Sweden)

    D. Dana

    2007-05-01

    Full Text Available ABSTRACTTwo species of Trichodinid were identified from sand goby, (Oxyeleotris marmorata fry of 6,1-8,0 mm long; T heterodentata and T nigra.  All parasite species were scraped from the skin of fry which were reared in fertilized pond.Key Word :  Sand goby, trichodinids ABSTRAKDua spesies dari genus Trichodina telah diidentifikasi dari benih ikan Betutu, (Oxyeleotris marniorata yang berukuran 6,1-8,0 mm.  Kedua spesies itu adalah T heterodentata dan T nigra.  Parasit tersebut diambil dari kulit ikan betutu yang dipelihara dalam kolam yang dipupuk.Kata kunci :  Ikan betutu, trichodina

  9. The Review of Ecological and Genetic Research of Ponto-Caspian Gobies (Pisces, Gobiidae in Europe

    Directory of Open Access Journals (Sweden)

    Jakšić Goran

    2016-09-01

    Full Text Available Invasive Ponto-Caspian gobies (monkey goby Neogobius fluviatilis, round goby Neogobius melanostomus and bighead goby Ponticola kessleri have recently caused dramatic changes in fish assemblage structure throughout European river systems. This review provides summary of recent research on their dietary habits, age and growth, phylogenetic lineages and gene diversity. The principal food of all three species is invertebrates, and more rarely fish, which depends on the type of habitat, part of the year, as well as the morphological characteristics of species. According to the von Bertalanffy growth model, size at age is specific for the region, but due to its disadvantages it is necessary to test other growth models. Phylogenetic analysis of monkey goby and round goby indicates separation between the Black Sea and the Caspian Sea haplotypes. The greatest genetic diversity is found among populations of the Black Sea, and the lowest among European invaders. The lack of molecular research on bighead goby requires further studies.

  10. Study of food habits of Goby, Porogobius schlegelii (Gunther, 1861 ...

    African Journals Online (AJOL)

    The study examines the food habits of goby, Porogobius schelgelii from the artisanal fisheries of the Bonny River in the Niger Delta. The results show that detritus, diatoms and blue-green algae are the primary food items followed by sand granules, macrophytes and nematodes as secondary food items. Protozoa. Fish eggs ...

  11. Contraction of the Gobi Desert, 2000–2012

    Directory of Open Access Journals (Sweden)

    Troy Sternberg

    2015-01-01

    Full Text Available Deserts are critical environments because they cover 41% of the world’s land surface and are home to 2 billion residents. As highly dynamic biomes desert expansion and contraction is influenced by climate and anthropogenic factors with variability being a key part of the desertification debate across dryland regions. Evaluating a major world desert, the Gobi in East Asia, with high resolution satellite data and the meteorologically-derived Aridity Index from 2000 to 2012 identified a recent contraction of the Gobi. The fluctuation in area, primarily driven by precipitation, is at odds with numerous reports of human-induced desertification in Mongolia and China. There are striking parallels between the vagueness in defining the Gobi and the imprecision and controversy surrounding the Sahara desert’s southern boundary in the 1980s and 1990s. Improved boundary definition has implications fGobi; desert boundary; expansion and contraction; Aridity Index; NDVI; Mongolia; China or understanding desert “greening” and “browning”, human action and land use, ecological productivity and changing climate parameters in the region. The Gobi’s average area of 2.3 million km2 in the 21st century places it behind only the Sahara and Arabian deserts in size.

  12. Mongolia : Groundwater Assessment of the Southern Gobi Region

    OpenAIRE

    World Bank

    2010-01-01

    The report looks critically at the water resources and the current and projected future water demands in the Southern Gobi Region (SGR) using the widely dispersed data and information that are currently available. An important conclusion of the report is that almost all the significant sources of groundwater in the SGR are 'fossil' or 'non-renewable', meaning that they are finite resources...

  13. Marine, freshwater and aerially acclimated mangrove rivulus (Kryptolebias marmoratus) use different strategies for cutaneous ammonia excretion

    Science.gov (United States)

    Cooper, Christopher A.; Wilson, Jonathan M.

    2013-01-01

    Rhesus (Rh) glycoproteins are ammonia gas (NH3) channels known to be involved in ammonia transport in animals. Because of the different osmoregulatory and ionoregulatory challenges faced by teleost fishes in marine and freshwater (FW) environments, we hypothesized that ammonia excretion strategies would differ between environments. Also, we hypothesized that cutaneous NH3 volatilization in air-acclimated fish is facilitated by base secretion. To test these hypotheses, we used the skin of the euryhaline amphibious mangrove rivulus (Kryptolebias marmoratus). The skin excretes ammonia and expresses Rh glycoproteins. Serosal-to-mucosal cutaneous ammonia flux was saturable (0–16 mmol/l ammonia, Km of 6.42 mmol/l). In FW, ammonia excretion increased in response to low mucosal pH but decreased with pharmacological inhibition of Na+/H+ exchangers (NHE) and H+ ATPase. Conversely, in brackish water (BW), lowering the mucosal pH significantly decreased ammonia excretion. Inhibitors of NHE also decreased ammonia excretion in BW fish. Immunofluorescence microscopy demonstrated that both the Rh isoform, Rhcg1, and NHE3 proteins colocalized in Na+/K+ ATPase expressing mitochondrion-rich cells in the gills, kidney, and skin. We propose that the mechanisms of cutaneous ammonia excretion in FW K. marmoratus are consistent with the model for branchial ammonia excretion in FW teleost fish. NH4+ excretion appeared to play a stronger role in BW. NH4+ excretion in BW may be facilitated by apical NHE and/or diffuse through paracellular pathways. In aerially acclimated fish, inhibition of NHE and H+ ATPase, but not the Cl−/HCO3− exchanger, significantly affected cutaneous surface pH, suggesting that direct base excretion is not critical for NH3 volatilization. Overall, K. marmoratus use different strategies for excreting ammonia in three different environments, FW, BW, and air, and Rh glycoproteins and NHE are integral to all. PMID:23389109

  14. Occurrence and food habits of the round goby in the profundal zone of southwestern Lake Ontario

    Science.gov (United States)

    Walsh, M.G.; Dittman, D.E.; O'Gorman, R.

    2007-01-01

    Little is known about the ecology of round goby (Neogobius melanostomus), an invasive benthic fish, in the profundal zone of the Great Lakes. In April 2002–2005 we caught increasing numbers of round gobies with a bottom trawl in the 45–150 m depth range of southwestern Lake Ontario. In 2005, we examined gut contents of 30 round gobies from each of three depths, 55, 95, and 130 m, and qualitatively compared gut contents with density of benthic invertebrates determined by Ponar grabs. Round goby guts contained mostly Dreissena spp. and opposum shrimp, Mysis relicta (Mysis); the frequency of occurrence of dreissenids in guts decreased with depth, whereas the frequency of occurrence of Mysis in guts increased with depth. Abundance of these invertebrates in the environment followed the same pattern, although dreissenids of optimum edible size (3–12 mm) were still abundant (1,373/m2) at 130 m, where round gobies primarily consumed Mysis, suggesting that round gobies may switch from dreissenids to more profitable prey when it is available. Other food items were ostracods and fish, with ostracods generally eaten by smaller round gobies and fish eaten by larger round gobies. Occurrence and increasing abundance of round gobies in the profundal zone and predation on Mysis by round goby could have far-reaching consequences for the Lake Ontario fish community.

  15. Contraction of the Gobi Desert, 2000–2012

    OpenAIRE

    Sternberg, Troy; Rueff, Henri; Middleton, Nick

    2015-01-01

    Deserts are critical environments because they cover 41% of the world’s land surface and are home to 2 billion residents. As highly dynamic biomes desert expansion and contraction is influenced by climate and anthropogenic factors with variability being a key part of the desertification debate across dryland regions. Evaluating a major world desert, the Gobi in East Asia, with high resolution satellite data and the meteorologically-derived Aridity Index from 2000 to 2012 identified a r...

  16. Study of the microwave emissivity characteristics over Gobi Desert

    International Nuclear Information System (INIS)

    Yubao, Qiu; Lijuan, Shi; Wenbo, Wu

    2014-01-01

    The microwave emissivity represents the capacity of the thermal radiation of the surface, and it is the significant parameter for understanding the geophysical processes such as surface energy budget and surface radiation. Different land covers have different emissivity properties, and the Gobi Desert in Central Asia seriously impact the sandstorms occur and develop in China, because of its special geographical environment and surface soil characteristics. In this study half-month averaged microwave emissivity from March 2003 to February 2004 over the Gobi Desert has been estimated. Emissivities in this area at different frequencies, polarization and their seasonal variations are discussed respectively. The results showed that emissivity polarization difference decrease as the frequency increases, and the polarization difference is large (0.03–0.127). The H polarization emissivity increases with increasing frequency, but the V-polarized microwave emissivity is reduced with increasing frequency because of the body scattering. In winter, emissivity decreases sharply in snow covered area, especially for higher frequencies (such as 89GHz). In addition, we compared emissivity with MODIS NDVI data at the same time in the Gobi Desert, and the results indicate that NDVI derived the good negative correlation with microwave emissivity polarization difference at 37GHz

  17. Morphological and Molecular Characterization of Clinostomum detruncatum (Trematoda: Clinostomidae) Metacercariae Infecting Synbranchus marmoratus.

    Science.gov (United States)

    Acosta, Aline Angelina; Caffara, Monica; Fioravanti, Maria Letizia; Utsunomia, Ricardo; Zago, Aline Cristina; Franceschini, Lidiane; da Silva, Reinaldo José

    2016-02-01

    A complete morphological description, supported by molecular data, of Clinostomum detruncatum metacercariae is reported in this study. The metacercariae were found infecting Synbranchus marmoratus from the Paraná River, municipality of Guaíra, Paraná State, Brazil. The taenioidean uterus is the main morphological characteristic of this species. Both neighbor-joining (NJ) and maximum likelihood (ML) trees showed 2 clear separate clusters grouping together the species from the Palearctic region (Clinostomum complanatum, Clinostomum cutaneum, Clinostomum phalacrocoracis, Clinostomum philippinense) and those from the Nearctic/Neotropical regions (Clinostomum marginatum, Clinostomum tataxumui, C. detruncatum, Clinostomum sp. 7). The latter clade is divided into 2 subclades grouping species from North America and Mexico (C. marginatum and C. tataxumui), and those from Brazil (C. detruncatum and Clinostomum sp. 7).

  18. The Gobi dance suite, a paradigm of acculturation | Nii-Yartey ...

    African Journals Online (AJOL)

    ... originally from the Ivory Coast, is an example of the role dance plays in uniting the community. Even though the Wangara and Banda see themselves as different ethnic groups, they are united as one through their participation in Gobi. An important feature of Gobi is that the movements that form the form are a combination ...

  19. What can morphology tell us about ecology of four invasive goby species?

    Science.gov (United States)

    Jakubčinová, K; Simonović, P; Števove, B; Čanak Atlagić, J; Kováč, V

    2017-05-01

    This study presents a detailed comparative analysis of external morphology of four of the most invasive goby species in Europe (round goby Neogobius melanostomus, bighead goby Ponticola kessleri, monkey goby Neogobius fluviatilis and racer goby Ponticola gymnotrachelus) and interprets some ecological requirements of these species based on their morphological attributes. The results are evaluated within an ontogenetic context, and the morphological differences between the species are discussed in terms of the question: can special external shape adaptations help to assess the invasive potential of each species? The morphometric analyses demonstrate important differences between the four invasive gobies. Neogobius melanostomus appears to have the least specialized external morphology that may favour its invasive success: little specialization to habitat or diet means reduced restraints on overall ecological requirements. The other three species were found to possess some morphological specializations (P. kessleri to large prey, N. fluviatilis to sandy habitats and P. gymnotrachelus to macrophytes), but none of these gobies have managed to colonize such large areas or to reach such overall abundances as N. melanostomus. © 2017 The Fisheries Society of the British Isles.

  20. Chronic exposure to paclobutrazol causes hepatic steatosis in male rockfish Sebastiscus marmoratus and the mechanism involved

    Energy Technology Data Exchange (ETDEWEB)

    Sun Lingbin [State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiamen (China); Li Jinshou [Department of Biological Engineering, Ningde Normal University, Ningde City, Fujian (China); Zuo Zhenghong [State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiamen (China); Chen Meng [State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen (China); Wang Chonggang, E-mail: cgwang@xmu.edu.cn [State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiamen (China); State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen (China)

    2013-01-15

    Paclobutrazol (PBZ) is a triazole-containing fungicide which is widely used in agriculture. Acute toxicity can follow its extensive use but it is generally weaker than traditional pesticides such as organochlorine and organophosphorus. However, its adverse effects on aquatic organisms need to be investigated. This study was conducted to investigate the effect of PBZ exposure on the hepatic lipid metabolism of Sebastiscus marmoratus. After PBZ exposure for 50 days, hepatic lipid droplets were enlarged and the hepatic total lipid, triglyceride, total cholesterol and free fatty acid content had increased in a dose dependent manner compared to the control. The mRNA expression of lipid metabolism associated genes such as peroxisome proliferator-activated receptors (PPARs), androgen receptor, acetyl-CoA carboxylase 1, fatty acid synthesis, fatty acid bing protein 4, liver X receptor {alpha} (LXR{alpha}) and stearoyl-CoA desaturase were up-regulated by PBZ exposure. These results indicated that triazole-containing fungicides might affect the metabolism and health of fish via the multi-signal pathways of nuclear receptors such as PPARs and LXR.

  1. Interannual variations of the Gobi Desert area from 1982-1999

    Science.gov (United States)

    Yu, Fangfang; Price, Kevin P.; Ellis, James; Feddema, Johannes J.

    2003-07-01

    There continues to be controversies among scientists whether humans are contributing to land degradation (desertification) in arid and semi-arid regions of the world. One area of considerable interest is the Gobi desert of central Asia, which is one of the largest deserts on Earth. The Gobi Desert is of particular value for addressing this question because it is divided by two countries that employ vastly different land management practices. Land use in China is high intensity and in Mongolia land use is of low intensity. In this study, climate and satellite remotely sensed data from 1982-1999 were used to investigate interannual variations in the areal extent the Gobi Desert boundary. Our results show substantial year-to-year variations in the size of the Gobi desert which was strongly correlated with annual precipitation (R2 = 0.81, PGobi Desert boundary response to interannual climatic variation will require studies extended over a longer time period.

  2. Every drop counts: Interview with awardee Gabin Koto N'Gobi ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    2012-05-11

    May 11, 2012 ... Gabin Koto N'Gobi's research focuses on water. But it was the lack of water in the semi-arid northern region of his home country, Benin, which really motivated him. As part of his doctoral studies at the Université d'Abomey-Calavi, Koto N'Gobi designed a prototype for collecting dew – a design so innovative ...

  3. Reproduction of two-spotted goby, Gobiusculus flavescens, in captivity

    Directory of Open Access Journals (Sweden)

    Vera Teles

    2014-06-01

    Full Text Available The two-spotted goby, Gobiusculus flavescens, is a common fish species along rocky shores in northern European waters. It is a small (40-60 mm, semipelagic marine fish, forming loose shoals in association with microalgae vegetation and mussel beds growing on the rock surface. It is a short-lived species, with a life span of 1-2 years. Both sexes display courtship behaviour and have sexual ornamentation during the breeding season. Male ornaments consist of large dorsal fins with iridescent blue lines, and iridescent blue spots along the sides of the body. Females develop a conspicuous, bright orange belly at sexual maturity. Due to these characteristics this species could have a great interest for ornamental aquariums. In previous work the maintenance of G. flavescens at high temperatures (until 23°C was successful. The aim of this study was to test the reproduction in captivity of G. flavescens. Six replicates were used (18L aquariums at the temperature of 18°C. In each replicate, two males and four females were introduced to an aquarium, where the males chose between two nests and courted the females. During the 112 days of the experiment the females spawned five times but only three spawns had success. The eggs take approximately 8 days to become mature. On the three spawns have hatched 300, 361 and 510 larvae at a time. The larvae were kept in a separate container and fed with alive rotifers and survived a maximum of 21 days. The reproduction of the two-spotted goby in captivity is possible at 18°C, but it is necessary to improve the conditions to rearing the larvae.

  4. An abundant small sized fish as keystone species? The effect of Pomatoschistus microps on food webs and its trophic role in two intertidal benthic communities: A modeling approach

    Science.gov (United States)

    Pockberger, Moritz; Kellnreitner, Florian; Ahnelt, Harald; Asmus, Ragnhild; Asmus, Harald

    2014-02-01

    Ecological network analysis (ENA) was used to study the effects of Pomatoschistus microps on energy transport through the food web, its impact on other compartments and its possible role as a keystone species in the trophic webs of an Arenicola tidal flat ecosystem and a sparse Zostera noltii bed ecosystem. Three ENA models were constructed: (a) model 1 contains data of the original food web from prior research in the investigated area by Baird et al. (2007), (b) an updated model 2 which included biomass and diet data of P. microps from recent sampling, and (c) model 3 simulating a food web without P. microps. A comparison of energy transport between the different models revealed that more energy is transported from lower trophic levels up the food chain, in the presence of P. microps (models 1 and 2) than in its absence (model 3). Calculations of the keystone index (KSi) revealed the high overall impact (measured as εi) of this fish species on food webs. In model 1, P. microps was assigned a low KSi in the Arenicola flat and in the sparse Z. noltii bed. Calculations in model 2 ranked P. microps first for keystoneness and εi in both communities, the Arenicola flat and the sparse Z. noltii bed. Taken together, our results give insight into the role of P. microps when considering a whole food web and reveal direct and indirect trophic interactions of this small-sized fish species. These results might illustrate the impact and importance of abundant, widespread species in food webs and facilitate further investigations.

  5. Diet shift of double-crested cormorants in eastern Lake Ontario associated with the expansion of the invasive round goby

    Science.gov (United States)

    Johnson, James H.; Ross, Robert M.; McCullough, Russell D.; Mathers, Alastair

    2010-01-01

    The proliferation of the invasive round goby (Apollonia melanostoma) in the Great Lakes has caused shifts in the trophic ecology in some areas. We examined the diet of double-crested cormorants (Phalacrocorax auritas) prior to, and immediately after, round goby population expansion at two colonies, Pigeon and Snake Islands, in eastern Lake Ontario from 1999 to 2007. Cormorant diet was determined from the examination of 10,167 pellets collected over the nine-year period. By the second year round gobies were found in the diet (2002 at Snake Island and 2003 at Pigeon Island) they were the main species consumed by cormorants at each colony. The dominance of round goby in cormorant diets had a significant effect on both daily fish consumption and seasonal trends in fish consumption compared to the pre-goby years. Seasonal differences that were observed during the pre-goby years were lost once gobies became the main diet component of cormorants. The rapid switch to a benthic prey such as round goby, from a largely limnetic fish diet demonstrates the adaptive foraging ability of cormorants. Round goby may act as a buffer for yellow perch and smallmouth bass, two sport fish impacted by cormorant predation in eastern Lake Ontario.

  6. Modeling marbled murrelet (Brachyramphus marmoratus) habitat using LiDAR-derived canopy data

    Science.gov (United States)

    Hagar, Joan C.; Eskelson, Bianca N.I.; Haggerty, Patricia K.; Nelson, S. Kim; Vesely, David G.

    2014-01-01

    LiDAR (Light Detection And Ranging) is an emerging remote-sensing tool that can provide fine-scale data describing vertical complexity of vegetation relevant to species that are responsive to forest structure. We used LiDAR data to estimate occupancy probability for the federally threatened marbled murrelet (Brachyramphus marmoratus) in the Oregon Coast Range of the United States. Our goal was to address the need identified in the Recovery Plan for a more accurate estimate of the availability of nesting habitat by developing occupancy maps based on refined measures of nest-strand structure. We used murrelet occupancy data collected by the Bureau of Land Management Coos Bay District, and canopy metrics calculated from discrete return airborne LiDAR data, to fit a logistic regression model predicting the probability of occupancy. Our final model for stand-level occupancy included distance to coast, and 5 LiDAR-derived variables describing canopy structure. With an area under the curve value (AUC) of 0.74, this model had acceptable discrimination and fair agreement (Cohen's κ = 0.24), especially considering that all sites in our sample were regarded by managers as potential habitat. The LiDAR model provided better discrimination between occupied and unoccupied sites than did a model using variables derived from Gradient Nearest Neighbor maps that were previously reported as important predictors of murrelet occupancy (AUC = 0.64, κ = 0.12). We also evaluated LiDAR metrics at 11 known murrelet nest sites. Two LiDAR-derived variables accurately discriminated nest sites from random sites (average AUC = 0.91). LiDAR provided a means of quantifying 3-dimensional canopy structure with variables that are ecologically relevant to murrelet nesting habitat, and have not been as accurately quantified by other mensuration methods.

  7. Testing the effectiveness of automated acoustic sensors for monitoring vocal activity of Marbled Murrelets Brachyramphus marmoratus

    Science.gov (United States)

    Cragg, Jenna L.; Burger, Alan E.; Piatt, John F.

    2015-01-01

    Cryptic nest sites and secretive breeding behavior make population estimates and monitoring of Marbled Murrelets Brachyramphus marmoratus difficult and expensive. Standard audio-visual and radar protocols have been refined but require intensive field time by trained personnel. We examined the detection range of automated sound recorders (Song Meters; Wildlife Acoustics Inc.) and the reliability of automated recognition models (“recognizers”) for identifying and quantifying Marbled Murrelet vocalizations during the 2011 and 2012 breeding seasons at Kodiak Island, Alaska. The detection range of murrelet calls by Song Meters was estimated to be 60 m. Recognizers detected 20 632 murrelet calls (keer and keheer) from a sample of 268 h of recordings, yielding 5 870 call series, which compared favorably with human scanning of spectrograms (on average detecting 95% of the number of call series identified by a human observer, but not necessarily the same call series). The false-negative rate (percentage of murrelet call series that the recognizers failed to detect) was 32%, mainly involving weak calls and short call series. False-positives (other sounds included by recognizers as murrelet calls) were primarily due to complex songs of other bird species, wind and rain. False-positives were lower in forest nesting habitat (48%) and highest in shrubby vegetation where calls of other birds were common (97%–99%). Acoustic recorders tracked spatial and seasonal trends in vocal activity, with higher call detections in high-quality forested habitat and during late July/early August. Automated acoustic monitoring of Marbled Murrelet calls could provide cost-effective, valuable information for assessing habitat use and temporal and spatial trends in nesting activity; reliability is dependent on careful placement of sensors to minimize false-positives and on prudent application of digital recognizers with visual checking of spectrograms.

  8. Marine Habitat Selection by Marbled Murrelets (Brachyramphus marmoratus during the Breeding Season.

    Directory of Open Access Journals (Sweden)

    Teresa J Lorenz

    Full Text Available The marbled murrelet (Brachyramphus marmoratus is a declining seabird that is well-known for nesting in coastal old-growth forests in the Pacific Northwest. Most studies of habitat selection have focused on modeling terrestrial nesting habitat even though marine habitat is believed to be a major contributor to population declines in some regions. To address this information gap, we conducted a 5-year study of marine resource selection by murrelets in Washington, which contains a population experiencing the steepest documented declines and where marine habitat is believed to be compromised. Across five years we tracked 157 radio-tagged murrelets during the breeding season (May to August, and used discrete choice models to examine habitat selection. Using an information theoretic approach, our global model had the most support, suggesting that murrelet resource selection at-sea is affected by many factors, both terrestrial and marine. Locations with higher amounts of nesting habitat (β = 21.49, P < 0.001 that were closer to shore (β = -0.0007, P < 0.001 and in cool waters (β = -0.2026, P < 0.001 with low footprint (β = -0.0087, P < 0.001 had higher probabilities of use. While past conservation efforts have focused on protecting terrestrial nesting habitat, we echo many past studies calling for future efforts to protect marine habitat for murrelets, as the current emphasis on terrestrial habitat alone may be insufficient for conserving populations. In particular, marine areas in close proximity to old-growth nesting habitat appear important for murrelets during the breeding season and should be priorities for protection.

  9. Non-native gobies facilitate the transmission of Bucephalus polymorphus (Trematoda).

    Science.gov (United States)

    Ondračková, Markéta; Hudcová, Iveta; Dávidová, Martina; Adámek, Zdeněk; Kašný, Martin; Jurajda, Pavel

    2015-07-19

    Introduced species can modify local host-parasite dynamics by amplifying parasite infection which can 'spill-back' to the native fauna, whether they are competent hosts for local parasites, or by acting as parasite sinks with 'dilution' of infection decreasing the parasite burden of native hosts. Recently infection by the trematode Bucephalus polymorphus has increased in several European rivers, being attributed to the introduction of intermediate host species from the Ponto-Caspian region. Using a combination of field and experimental data, we evaluated the competence of non-native and native fish as intermediate hosts for B. polymorphus and its role for parasite development in a definitive host. The density of 0+ juvenile fish (the second intermediate hosts for B. polymorphus) was measured in the River Morava, Czech Republic and fish were screened for natural metacercariae infection. The stomach contents of predatory fish that are definitive hosts of B. polymorphus were examined to assess the importance of non-native gobies for parasite transmission. In semi-natural conditions, parasite establishment, initial survival, and maturity rates in experimentally infected definitive hosts pikeperch Sander lucioperca were measured in flukes recovered from native white bream Abramis bjoerkna and non-native tubenose goby Proterorhinus semilunaris and round goby Neogobius melanostomus. Adult fluke size and egg production was also measured to evaluate the potential effect of intermediate host species on parasite fitness. We detected high natural infection parameters of B. polymorphus in native cyprinids and non-native gobies compared to data from the period prior to goby establishment. Both fish groups are consumed by predatory fish and represent a major component of the littoral fish community. Parasite establishment and adult size in definitive hosts was equivalent among the second intermediate host species, despite a lower size of metacercariae recovered from round gobies

  10. The Relationship of Body Length and Ratio Pappilla with Sex in Gobi Fish (Sicyopterus macrostetholepis

    Directory of Open Access Journals (Sweden)

    Rona Taula Sari

    2017-07-01

    Full Text Available Research about the relationship of body length and ratio papilla with sex in goby fish (S. macrostetholepis Blkr. has been done at Animal Structure and Developmental Laboratory, Biologi Department, Faculty of Matematics and Natural Sciences, Andalas University, Padang, which purposed to analyse the relationship of body length and ratio papilla with sex of goby fish (S. macrostetholepis Blkr.. The samples were taken in wild stream area at Batangkuranji river, Padang City. This research used descriptive method and data were analyzed by qualitatively and quantitatively. The results of investigation showed that in several goby fishes (S. macrostetholepis Blkr. with different sex had the same of body length and the same of ratio papilla. So, there was not relationship between of body length and ratio papilla with sex.  Goby fishes (S. macrostetholepis Blkr. it belongs to the hermaphrodite protogini, which the androgynous young females, while in adulthood, it would change sex to male. The results of this study are expected to add to the treasures of knowledge and information about reproductive gobies (S. macrostetholepis Blkr. in the preservation and development of fish farming.   

  11. The diet of reservoir perch before, during and after establishment of non-native tubenose goby

    Directory of Open Access Journals (Sweden)

    Všetičková Lucie

    2018-01-01

    Full Text Available In recent decades, gobiid species have increased their distribution throughout Europe and now often represent the dominant genus along many rivers and canals. In this study, we assessed the role of tubenose goby (Proterorhinus semilunaris as a prey species of native perch (Perca fluviatilis in a lowland reservoir soon after their initial introduction in 1994 (sampling started 1998 and 17 years after establishment (2011–2012. We compare these data with perch diet composition from before introduction (1981–1982. Our data indicate that tubenose gobies quickly became the dominant species along the reservoir bankside, making them an attractive prey for ≥1 + perch. There was a clear increasing trend in the numbers of larger perch caught along the rip-rap, with the largest fish clearly specialising on gobies. As such, introduction of tubenose gobies has had a pronounced effect on food web and population dynamics along the littoral zone. While goby numbers appear to have dropped significantly in recent years, apparently due to predation pressure, further studies are needed to assess whether such changes have had any general impact on population and food web dynamics within the reservoir.

  12. Cryptic Ponto-Caspian Bighead Gobies (genus Ponticola, Gobiidae, Perciformes

    Directory of Open Access Journals (Sweden)

    Dmitry Alexandrovich Medvedev

    2015-11-01

    In this way, P. iljini, P. gorlap, and P. kessleri represent a group of distinct allopatric cryptic species with very low morphological divergence. The start of the divergence between P. kessleri and the Caspian species can be dated no earlier than the end of the Miocene (5.8-5.0 million years ago when the Pontian sea-lake has divided into two separate brackish pools: the later Pontian sea-lake basin and Babadzhanskoe sea-lake in the southern part of the Caspian depression. But, at the same time, it can be dated not later than Pleistocene (2.0-0.7 Ma, when the last connection of the Caspian and the Black Sea through the Manych has been stopped. The ancestors of P. iljini could penetrate to the east coast of the Caspian Sea during the period of the largest transgressions, Akchagyl (2.5-2.0 Ma or Apsheron (2.0-0.7 Ma. Their isolation in the Mangyshlak Peninsula region from other Caspian Bighead goby populations has been provided by two hypersaline bays, limiting the peninsula from the north (Mërtvyj Kultuk and Kajdak bays with salinity of 30 ‰ and above and from the south (Kara-Bogaz-Gol Bay with salinity of 300-350 ‰ and above, as well as the lack of a network of rivers on the peninsula.

  13. Using dissolved carbon dioxide to alter the behavior of invasive round goby

    Science.gov (United States)

    Cupp, Aaron R.; Tix, John; Smerud, Justin R.; Erickson, Richard A.; Fredricks, Kim; Amberg, Jon; Suski, Cory D.; Wakeman, Robert

    2017-01-01

    Fisheries managers need effective methods to limit the spread of invasive round goby Neogobius melanostomus in North America. Elevating carbon dioxide (CO2) in water at pinch points of rivers (e.g., inside locks) is one approach showing potential to deter the passage of invasive fishes, such as bigheaded carps Hypophthalmichthys spp., but the effectiveness of this method to alter round goby behavior has not been determined. The goal for this study was to determine CO2 concentrations that alter round goby behavior across a range of water temperatures. Free-swimming avoidance (voluntary response) and loss of equilibrium (involuntary response) were quantified by exposing round goby to increasing CO2 concentrations at 5, 15, and 25 °C using a shuttle box choice arena and static tank. Water chemistry was measured concurrent with behavioral endpoints and showed that round goby avoided a threshold of 99–169 mg/L CO2(79,000–178,000 µatm) and lost equilibrium at 197–280 mg/L CO2 (163,000–303,000 µatm). Approximately 50% lower CO2 concentrations were found to modify behavior at 5 °C relative to 25 °C, suggesting greater effectiveness at lower water temperatures. We conclude that CO2 modified round goby behavior and concentrations determined in this study are intended to guide field testing of CO2 as an invasive fish deterrent.

  14. Life cycle of the pelagic goby Aphia minuta (Pisces: Gobiidae

    Directory of Open Access Journals (Sweden)

    M. Iglesias

    2001-09-01

    Full Text Available Reproductive aspects of the transparent goby Aphia minuta (n=2977, 14-45 mm total length (TL were studied in Majorcan waters, western Mediterranean, during the fishing season (December to April from 1985 to 1993. Male:female sex ratio was 1:1. Size at first maturity was 38 mm TL for females and 34 mm TL for males. Oocyte size-frequency distribution indicated that A. minuta is a single spawner. Fecundity of A. minuta ranged from 935 to 2648 oocytes. The breeding season extended from December to April with a peak in March. After a single reproduction at 5-6 months of age, most of the specimens disappeared from the fishing areas. Recruitment to the fishing area occurred in late December and early January (14-24 mm TL, age 2-3 months. On the other hand, the hatch date back-calculated from the age in days and the date of capture of individuals of A. minuta during the fishing season, indicated a spawning peak in autumn (September-October, six months after the peak of observed spawning. Schools of A. minuta were detected by acoustic methods, during the fishing season (winter-spring in fishing areas (5-40 m depth, principally inside bays, and during the rest of the year (summer and autumn in deeper areas (40-90 m, outside bays, with water temperatures between 13 and 16ºC and a high seasonal productivity in each depth range. Therefore, we propose that A. minuta has two annual cohorts in the western Mediterranean, corresponding to two main spawning in spring and autumn, respectively. Life history pattern indicated that we only know the winter cohort resulting from the autumn spawning. Meanwhile the summer cohort (spring spawning grows and reproduces in deeper areas not being targeted by the fishery. Indirect validation is provided from information from other areas. The relevance of the life cycle is discussed in relation to fishery management.

  15. Tetrodotoxin poisoning caused by Goby fish consumption in southeast China: a retrospective case series analysis

    Directory of Open Access Journals (Sweden)

    Jie You

    2015-01-01

    Full Text Available OBJECTIVES: To investigate an unusual outbreak of tetrodotoxin poisoning in Leizhou, southeast China, a case series analysis was conducted to identify the source of illness. METHODS: A total of 22 individuals experienced symptoms of poisoning, including tongue numbness, dizziness, nausea and limb numbness and weakness. Two toxic species, Amoya caninus and Yongeichthys nebulosus, were morphologically identified from the batches of gobies consumed by the patients. Tetrodotoxin levels in the blood and Goby fish samples were detected using liquid chromatography-tandem mass spectrometry. RESULTS: The tetrodotoxin levels in the remaining cooked Goby fish were determined to be 2090.12 µg/kg. For Amoya caninus, the toxicity levels were 1858.29 µg/kg in the muscle and 1997.19 µg/kg in the viscera and for Yongeichthys nebulosus, they were 2783.00 µg/kg in the muscle and 2966.21 µg/kg in the viscera. CONCLUSION: This outbreak demonstrates an underestimation of the risk of Goby fish poisoning. Furthermore, the relationships among the toxic species, climates and marine algae present should be clarified in the future.

  16. Environment not "nativeness" dictates reproductive trait shifts in Ponto-Caspian gobies

    Czech Academy of Sciences Publication Activity Database

    Konečná, Markéta; Janáč, Michal; Roche, Kevin Francis; Jurajda, Pavel

    2016-01-01

    Roč. 25, č. 1 (2016), s. 167-170 ISSN 0906-6691 R&D Projects: GA ČR(CZ) GAP505/11/1768 Institutional support: RVO:68081766 Keywords : Pseudorasbora parva * invasive plants * populations * invader * range * goby Subject RIV: EG - Zoology Impact factor: 2.054, year: 2016

  17. Measuring the impacts of community-based grasslands conservation in Mongolia’s Gobi

    NARCIS (Netherlands)

    Leisher, C.; Hess, S.; Boucher, T.M.; van Beukering, P.J.H.; Sanjayan, M.

    2012-01-01

    We assessed a donor-funded grassland management project designed to create both conservation and livelihood benefits in the rangelands of Mongolia's Gobi desert. The project ran from 1995 to 2006, and we used remote sensing Normalized Differential Vegetation Index data from 1982 to 2009 to compare

  18. Pastoral community organization, livelihoods and biodiversity conservation in Mongolia's Southern Gobi Region

    Science.gov (United States)

    Sabine M. Schmidt

    2006-01-01

    In this paper I describe processes and impacts of collective action by mobile pastoralist communities, and of external support strategies to strengthen local institutions and cooperation in Mongolia’s southern Gobi. The need for pastoral mobility triggered the processes leading to community organization, and the emergence, or re-emergence, of local informal...

  19. Non-native gobies facilitate the transmission of Bucephalus polymorphus (Trematoda)

    Czech Academy of Sciences Publication Activity Database

    Ondračková, Markéta; Hudcová, Iveta; Dávidová, Martina; Adámek, Zdeněk; Kašný, M.; Jurajda, Pavel

    2015-01-01

    Roč. 8, č. 1 (2015), s. 382 ISSN 1756-3305 R&D Projects: GA ČR(CZ) GAP505/12/2569 Institutional support: RVO:68081766 Keywords : Bucephalus polymorphus * Complex life cycle * Goby * Infectivity * Intermediate host * Non-native species * Trematode Subject RIV: EH - Ecology, Behaviour Impact factor: 3.234, year: 2015

  20. Can round goby (Neogobius melanostomus) caught by rod and line be used for diet analysis?

    Czech Academy of Sciences Publication Activity Database

    Jurajda, Pavel; Všetičková, Lucie; Polačik, Matej; Vassilev, M.

    2013-01-01

    Roč. 39, č. 1 (2013), s. 182-185 ISSN 0380-1330 R&D Projects: GA ČR(CZ) GAP505/11/1768 Institutional support: RVO:68081766 Keywords : Neogobius melanostomus * Gobies * Danube * Diet * Sampling methodology * Selectivity Subject RIV: EH - Ecology, Behaviour Impact factor: 1.771, year: 2013

  1. Feeding with Artificial Feed on Sand Goby, Oxyeleotris marmorata (Blkr., Fry

    Directory of Open Access Journals (Sweden)

    Agus Oman Sudrajat

    2007-12-01

    Full Text Available ABSTRACTThe influence of feed shape and protein resource of artificial feed on the growth and survival rate of sand goby, Oxyeleotris marmorata (Blkr., fry were evaluated in this experiment. This experiment purposed to determine growth rate, survival rate, feeding efficiency, protein retention, lypid retention and look for the suitable artificial feed for sand goby. This experiment was carried out at the Laboratory of Aquaculture System and Technology, Department of Aquaculture, Faculty of Fisheries and Marine Sciences, Bogor Agricultural University in Bogor. Factorial design was used in this experiment with two factors: feed shape and protein resource. There were two kinds of feed shape: dry pellet and moist pellet. Protein resource consisted: fish, squid, and shrimp. The sand goby juveniles were kept in aquarium 60x30x40 cm was filled 40 litre of aerated. The fish were fed of 7% (dry weight based of body weight in three time of feeding (10:00, 14:00, 18:00 WIB, 30, 30, 40% total feed/day respectively. The amount of feed was adjusted every 7 days with sampling. The juveniles feeding with shrimp-moist showed better survival rate, growth rate, feeding efficiency, protein retention, lypid retention than those fed shrimp-dry, squid-dry, squid-moist, fish-dry, and fish-moist. Dry pellet and moist pellet can be used for sand goby feeding. The artificial feed for sand goby juvenile suggested contain attractant and had highly water stability. Shrimp and squid can be used as main protein resources in artificial feed for sand goby. Key Word :  Feeding, artificial feed, sand goby, Oxyeleotris  marmorata, fry. ABSTRAKPenelitian ini bertujuan untuk mengetahui pengaruh bentuk pakan dan sumber protein dari pakan buatan terhadap pertumbuhan dan kelangsungan hidup ikan betutu, Oxyeleotris marmorata (Blkr.. Rancangan faktorial dengan 2 faktor, bentuk pakan (pelet basah dan pelet kering dan sumber protein (ikan, cumi dan udang digunakan dalam penelitian ini

  2. Upstream expansion of round goby (Neogobius Melanostomus – first record in the upper reaches of the Elbe river

    Directory of Open Access Journals (Sweden)

    Buřič M.

    2015-01-01

    Full Text Available The round goby Neogobius melanostomus (Pallas, 1814 is one of the most problematic invasive fish species in recent years in Europe. It has proliferated from its native Ponto-Caspian region to several European river systems including their mouths and coastal brackish waters and was also introduced to and became widely established in the Great Lakes in North America. Despite recent reports about further invasions of round goby in the Odra and Vistula Rivers, including penetration of Baltic and North Seas, in the Elbe River this species was only recorded near its mouth close to Hamburg. Here we report the occurrence of round goby 622 km upstream from the previous record in Geesthacht (Germany in the upper part of the Elbe River in Usti nad Labem (Czech Republic. This report illustrates the fast spread of round goby through several possible pathways, but the most certain is an introduction in ballast water.

  3. Feeding activity and diet composition of round goby (Neogobius melanostomus in the coastal waters of SE Baltic Sea

    Directory of Open Access Journals (Sweden)

    Artūras Skabeikis

    2015-11-01

    Full Text Available The round goby (Neogobius melanostomus is a very successful invasive fish species, which was unintentionally introduced to the central Baltic Sea (Gulf of Gdansk in 1990. Several years later after initial introduction round goby established a viable population, highly increased in abundance and expanded to the south-eastern and northern Baltic Sea coastal waters, becoming a key component of benthic ichthyofauna in invaded areas. To evaluate a potential threat of round goby to the coastal zoobenthic communities, feeding patterns, including feeding activity and diet composition of this invasive fish was examined using gut content analysis. Sampling was performed in the SE Baltic Sea, Lithuanian coastal waters during May-October 2012. Round gobies >100 mm were caught with multimesh gill nets, while <100 mm individuals were collected using baited minnow trap. Dietary analysis was performed in 318 differently sized round gobies. Feeding activity of round goby varied depending on body size, sex and stage of the reproduction period. Diet composition of individuals with the body length <100 mm and ≥200 mm was relatively constant in the course of the study, while individuals of the intermediate 100-200 mm length had more variable diet, which used to change depending on season. The gut contents of <50 mm gobies were dominated by small zooplanktonic and meiobenthic organisms, shifting to amphipods and mollusks in larger individuals (50-99 mm. In spring 100-200 mm round gobies mainly consumed infaunal bivalves Macoma balthica, in summer - polychaetes Hediste diversicilor, while in autumn the share of epibenthic bivalves Mytilus trossulus and fish prey increased considerably in their diet. Diet of ≥200 mm individuals was predominated by mollusks during whole study period.

  4. Mountain building processes in intraplate, intracontinental oblique deformation belts: Lessons from the Gobi Altai, Mongolia

    Science.gov (United States)

    Cunningham, D.

    2012-04-01

    The Gobi Altai is an intraplate, intracontinental transpressional orogen in southern Mongolia that formed in the Late Cenozoic as a distant response to the Indo-Eurasia collision. The modern range formed within crust constructed by successive terrane accretion and ocean suturing events and widespread granite plutonism throughout the Palaeozoic. Modern reactivation of the Gobi Altai crust and the kinematics of Quaternary faults are fundamentally controlled by Palaeozoic basement structural trends, the location of rigid Precambrian blocks, orientation of SHmax and possible thermal weakening of the lower crust due to an extensive history of Mesozoic-Cenozoic basaltic volcanism in the region, and the presence of thermally elevated asthenosphere under the Hangay Dome to the north. Modern mountain building processes in the Gobi Altai typically involve reactivation of NW-striking basement structures in thrust mode and development of linking E-W left-lateral strike-slip faults which crosscut basement structures within an overall left-lateral transpressional regime. Restraining bends, other transpressional ridges and thrusted basement blocks are the main range type, but are discontinuously distributed and separated by internally drained basins filling with modern alluvial deposits. Unlike a contractional thrust belt, there is no orogenic foreland or hinterland, and thrusts are both NE and SW directed with no evidence for a basal decollement. Normal faults related to widespread Cretaceous rifting in the region are locally thrust reactivated in the NE Gobi Altai, but elsewhere appear to be unfavourably oriented for Late Cenozoic reactivation despite widespread topographic inversion of Cretaceous basin sequences. The diffuse historical seismicity in the region coupled with a complex system of interacting faults showing evidence for Quaternary movements, suggests that faults may be dormant for long periods and then reactivate. Large earthquakes may be episodic and spatially

  5. Parasites of non-native gobies in the Włocławek Reservoir on the lower Vistula River, first comprehensive study in Poland

    Directory of Open Access Journals (Sweden)

    Mierzejewska K.

    2014-04-01

    Full Text Available A parasitological study of Ponto-Caspian gobies, including the monkey goby Neogobius fluviatilis, racer goby Babka gymnotrachelus and tubenose goby Proterorhinus semilunaris, carried out over four years in the lower Vistula River is described. These fish species represent one of the most impressive invasions of European inland waters, connected with the spontaneous, east-to-west intracontinental movement observed in the last two decades. The parasite community consisted of 24 taxa. Typical for racer goby were: Trichodina domerguei, Diplostomum pseudospathaceum, Gyrodactylus proterorhini and glochidia of unionids. The list of parasites typical for monkey goby is supplemented with: Tylodelphys clavata (met. and Eimeria sp., while the glochidia were rarely detected in this fish host. Holostephanus spp., Apatemon gracilis, Diplostomum gobiorum and glochidia predominated in parasite fauna of tubenose goby. Unlike the other species tested, P. semilunaris was poorly infected with T. domerguei and G. proterorhini. Parasites commonly distributed through native fishes in the observed area prevailed in gobies. Species rare in natives were also numerously represented. In this way, alien fish reinforce populations of those parasites in invaded waters. Parasites dragged to the colonized area (G. proterorhini, Holostephanus spp., A. gracilis and D. gobiorum complement the community. Larval stages were typical for parasite fauna of all studied gobies.

  6. Twenty five years of invasion: management of the round goby Neogobius melanostomus in the Baltic Sea

    DEFF Research Database (Denmark)

    Ojaveer, Henn; Galil, Bella S.; Lehtiniemi, Maiju

    2015-01-01

    to be considered for post-invasion management. Priority should be given to the establishment of a coordinated pan-Baltic monitoring programme and associated data storage and exchange, as well as the compilation of landing statistics of the round goby in commercial and recreational fisheries. While eradication......, and hull fouling of inland and sea-going vessels, including recreational boats. Extensive involvement of stakeholders is crucial at all phases of the management process.......The round goby, Neogobius melanostomus (Pallas, 1814), is one of the most invasive non-indigenous species in the Baltic Sea. It dominates coastal fisheries in some localities and is frequently found in offshore pelagic catches. This paper identifies management issues and suggests actions...

  7. Place learning prior to and after telencephalon ablation in bamboo and coral cat sharks (Chiloscyllium griseum and Atelomycterus marmoratus).

    Science.gov (United States)

    Fuss, Theodora; Bleckmann, Horst; Schluessel, Vera

    2014-01-01

    This study assessed complex spatial learning and memory in two species of shark, the grey bamboo shark (Chiloscyllium griseum) and the coral cat shark (Atelomycterus marmoratus). It was hypothesized that sharks can learn and apply an allocentric orientation strategy. Eight out of ten sharks successfully completed the initial training phase (by locating a fixed goal position in a diamond maze from two possible start points) within 14.9 ± 7.6 sessions and proceeded to seven sets of transfer tests, in which sharks had to perform under altered environmental conditions. Transfer tests revealed that sharks had oriented and solved the tasks visually, using all of the provided environmental cues. Unintentional cueing did not occur. Results correspond to earlier studies on spatial memory and cognitive mapping in other vertebrates. Future experiments should investigate whether sharks possess a cognitive spatial mapping system as has already been found in several teleosts and stingrays. Following the completion of transfer tests, sharks were subjected to ablation of most of the pallium, which compromised their previously acquired place learning abilities. These results indicate that the telencephalon plays a crucial role in the processing of information on place learning and allocentric orientation strategies.

  8. Modelling the variation in larval dispersal of marbled rock crab Pachygrapsus marmoratus in the Gulf of Cadiz

    Science.gov (United States)

    T Pires, R.; Pan, M.; Peliz, A.; Santos, A. M. P. A.; Boutov, D.; Dos Santos, A.

    2016-02-01

    Pachygrapsus marmoratus is a common coastal crab occurring in rocky shores of the northeastern Atlantic and Mediterranean. Information on the planktonic larval phase for this species is still incomplete. However, for the first six zoeal stages a long larval duration of around 30 days was observed. Larvae are released in the intertidal area and exported to the shelf in order to complete their development. In situ data obtained during an oceanographic survey along the southern Portuguese coast in August 2010 consisting on CTD casts and plankton hauls were analyzed. The first five zoeal stages and megalopae were captured and results showed a progressively wider distribution towards offshore through the larval development with megalopae being found close to the coast. A modelling approach was employed to explain the mechanisms used by megalopae (last larval phase) to return to adult habitats. Their vertical distribution, oceanic circulation of the area and the points of larval release were integrated in the model to understand the influence of vertical migrations on the dispersal range of Pachygrapsus larvae.

  9. Effects of X-irradiation and thymectomy on the immune response of the marine teleost, Sebastiscus marmoratus

    International Nuclear Information System (INIS)

    Nakanishi, T.

    1986-01-01

    Effects of X-irradiation and thymectomy on the immune response of the rock fish, S. marmoratus were studied. Animals were thymectomized and irradiated at the dose of 2000 R. In non-thymectomized and irradiated fish, injected with SRBC one week after irradiation, antibody production was completely suppressed and they required twice the time for rejection of scales allografted three days after irradiation. On the other hand, fish which were irradiated four days after thymectomy and injected one week after irradiation, showed a fairly high level of antibody, although, in the allograft rejection, no significant difference was observed when compared to the irradiated fish. Furthermore, animals thymectomized, irradiated and autoimplanted showed higher production of antibody when immunized three months after irradiation compared to matched controls. In the same manner, in the allograft rejection, a slight restoration was found in fish reconstituted with a non-irradiated thymus. From these results, it is considered that, as in mammals, the adult thymus of fish plays an important role in recovery from the damage to the immune system caused by irradiation. Furthermore, a combination of X-irradiation and thymectomy suggests that suppressor T-cells which are resistant to X-rays exist in the fish thymus

  10. Systemic Homeostasis in Metabolome, Ionome, and Microbiome of Wild Yellowfin Goby in Estuarine Ecosystem.

    Science.gov (United States)

    Wei, Feifei; Sakata, Kenji; Asakura, Taiga; Date, Yasuhiro; Kikuchi, Jun

    2018-02-22

    Data-driven approaches were applied to investigate the temporal and spatial changes of 1,022 individuals of wild yellowfin goby and its potential interaction with the estuarine environment in Japan. Nuclear magnetic resonance (NMR)-based metabolomics revealed that growth stage is a primary factor affecting muscle metabolism. Then, the metabolic, elemental and microbial profiles of the pooled samples generated according to either the same habitat or sampling season as well as the river water and sediment samples from their habitats were measured using NMR spectra, inductively coupled plasma optical emission spectrometry and next-generation 16 S rRNA gene sequencing. Hidden interactions in the integrated datasets such as the potential role of intestinal bacteria in the control of spawning migration, essential amino acids and fatty acids synthesis in wild yellowfin goby were further extracted using correlation clustering and market basket analysis-generated networks. Importantly, our systematic analysis of both the seasonal and latitudinal variations in metabolome, ionome and microbiome of wild yellowfin goby pointed out that the environmental factors such as the temperature play important roles in regulating the body homeostasis of wild fish.

  11. Satellite Monitoring of Vegetation Response to Precipitation and Dust Storm Outbreaks in Gobi Desert Regions

    Directory of Open Access Journals (Sweden)

    Yuki Sofue

    2018-02-01

    Full Text Available Recently, droughts have become widespread in the Northern Hemisphere, including in Mongolia. The ground surface condition, particularly vegetation coverage, affects the occurrence of dust storms. The main sources of dust storms in the Asian region are the Taklimakan and Mongolian Gobi desert regions. In these regions, precipitation is one of the most important factors for growth of plants especially in arid and semi-arid land. The purpose of this study is to clarify the relationship between precipitation and vegetation cover dynamics over 29 years in the Gobi region. We compared the patterns between precipitation and Normalized Difference Vegetation Index (NDVI for a period of 29 years. The precipitation and vegetation datasets were examined to investigate the trends during 1985–2013. Cross correlation analysis between the precipitation and the NDVI anomalies was performed. Data analysis showed that the variations of NDVI anomalies in the east region correspond well with the precipitation anomalies during this period. However, in the southwest region of the Gobi region, the NDVI had decreased regardless of the precipitation amount, especially since 2010. This result showed that vegetation in this region was more degraded than in the other areas.

  12. Invasion strategies in round goby (Neogobius melanostomus: Is bigger really better?

    Directory of Open Access Journals (Sweden)

    Joerg Brandner

    Full Text Available Few studies have systematically investigated mid- or long-term temporal changes of biological characteristics in invasive alien species considering the different phases of an invasion. We studied the invasion performance of one of the most invasive species worldwide, the round goby Neogobius melanostomus, from total absence over first occurrence until establishment from 2010 to 2015 in the upper Danube River. After an upstream movement of the invasion front of about 30 river km within four years, the pattern that round goby pioneering populations significantly differ from longer established ones has been confirmed: Pioneering populations at the invasion front comprised more females than males, and adult specimens with a larger body size compared to those at longer inhabited areas. On the population-level, the proportion of juveniles increased with time since invasion. The results of this study provide support for the previously postulated ´bigger is better´ and ´individual trait utility´ hypotheses explaining invasion success in round goby. Pioneering invaders with their greater exploratory behavior, highly adaptive phenotypic plasticity and increased competitive ability seem to act as prime emperors of new habitats, strongly following and benefiting from man-made river-bank structures.

  13. Plate interior polyphase fault systems and sedimentary basin evolution: A case study of the East Gobi Basin and East Gobi Fault Zone, southeastern Mongolia

    Science.gov (United States)

    Heumann, Matthew J.; Johnson, Cari L.; Webb, Laura E.

    2018-01-01

    Structural interpretation of 2-D seismic reflection data and subsurface-outcrop correlations reveal six distinct phases of deformation recorded in the Paleozoic basement rocks and Mesozoic-Cenozoic basin fill of the East Gobi Basin (EGB), southeastern Mongolia. These phases include arc accretion and arc-continent collision in late Paleozoic time, Late Triassic sinistral shear-zone development, Early Jurassic fold and thrust belt style shortening, Middle Jurassic-Lower Cretaceous extension and rift basin development, middle Cretaceous shortening with basin inversion and regional unconformity development, and Late Cretaceous-Oligocene thermal subsidence with renewed Paleogene left-lateral strike slip faulting across the fault zone. The five post-amalgamation deformation phases are localized along the East Gobi Fault Zone, suggesting that preexisting structures and boundary conditions exert fundamental controls on the long term evolution of intracontinental basins such as the EGB. Subsurface geophysical data and outcrop correlations demonstrate that the main subbasins of the EGB contain major differences in basement metamorphic and structural fabrics, basin fill patterns, and distinct Mesozoic-Cenozoic fault generations. Potential causes related to far-field boundary conditions and other driving factors are suggested for each of the major deformation phases.

  14. Historical considerations and comments on the type series of Cyrtodactylus marmoratus Gray, 1831, with an updated comparative table for the bent-toed geckos of the Sunda Islands and Sulawesi.

    Science.gov (United States)

    Mecke, Sven; Kieckbusch, Max; Hartmann, Lukas; Kaiser, Hinrich

    2016-10-17

    Cyrtodactylus marmoratus Gray, 1831, a species of bent-toed gecko exhibiting a precloacal groove in males, was described on the basis of specimens collected by Heinrich Kuhl and Johan Conrad van Hasselt in Java, Greater Sunda Islands, Indonesia. Kluge (1985) subsequently designated a lectotype for C. marmoratus from a series of these specimens (i.e., syntypes), now housed in the herpetological collection at Naturalis (formerly the Rijksmuseum van Natuurlijke Historie; RMNH), Leiden, the Netherlands. Our work at Naturalis shows that the type series of C. marmoratus at RMNH actually comprises two sets of specimens, and that examination of specimens from one set or the other by different authors, including Kluge (1985), is responsible for some confusion surrounding the type series of this species. As a consequence, we present relevant morphological data for all 14 specimens constituting the type series of C. marmoratus at RMNH for the first time. The type status of two specimens of C. marmoratus in the collection at the Muséum National d'Histoire Naturelle, Paris, France, remains unresolved at present. Owing to the inconsistent naming and application of terms for some key characters (e.g., groove, sulcus, pit, hollow, depression) used in the diagnoses of Cyrtodactylus species, we here propose a set of novel and useful definitions that are supported by photographs. We also illustrate the sexually dimorphic expression of this character in C. marmoratus. Finally, we present a revised comparative table for the bent-toad geckos of the Sunda Islands and Sulawesi.

  15. Population and habitat status of two endemic sand gobies in lagoon marshes - Implications for conservation

    Science.gov (United States)

    Franco, A.; Franzoi, P.; Malavasi, S.; Zucchetta, M.; Torricelli, P.

    2012-12-01

    Ensuring biodiversity, through the conservation of natural habitats, such as wetlands, and of their wild flora and fauna, is the main objective of the Habitat and Species Directive 92/43/EC. Within this framework, two species of Community interest, Pomatoschistus canestrinii and Knipowitschia panizzae (Gobiidae, Osteichthyes), endemisms of the Northern Adriatic lagoons, were considered. The population structure, reproductive effort, somatic growth and production of such species were investigated in marsh habitats of the Venice lagoon, as indicators of the status of the populations and their habitats. The lagoon marsh habitats hosted abundant and well structured populations, functioning also as breeding areas for these species. A certain spatial variability was also observed, possibly related to the shelter conditions of different marsh sub-habitats (e.g. marsh creeks vs. adjacent mudflats). These results were discussed in the light of the available ecological knowledge on the two species, with a particular attention to the conservation priority focused on the protection of biodiversity and of key habitats.

  16. Cloning of circadian rhythmic pathway genes and perturbation of oscillation patterns in endocrine disrupting chemicals (EDCs)-exposed mangrove killifish Kryptolebias marmoratus.

    Science.gov (United States)

    Rhee, Jae-Sung; Kim, Bo-Mi; Lee, Bo-Young; Hwang, Un-Ki; Lee, Yong Sung; Lee, Jae-Seong

    2014-08-01

    To investigate the effect of endocrine disrupting chemicals (EDCs) on the circadian rhythm pathway, we cloned clock and circadian rhythmic pathway-associated genes (e.g. Per2, Cry1, Cry2, and BMAL1) in the self-fertilizing mangrove killifish Kryptolebias marmoratus. The promoter region of Km-clock had 1 aryl hydrocarbon receptor element (AhRE, GTGCGTGACA) and 8 estrogen receptor (ER) half-sites, indicating that the AhRE and ER half sites would likely be associated with regulation of clock protein activity during EDCs-induced cellular stress. The Km-clock protein domains (bHLH, PAS1, PAS2) were highly conserved in five additional fish species (zebrafish, Japanese medaka, Southern platyfish, Nile tilapia, and spotted green pufferfish), suggesting that the fish clock protein may play an important role in controlling endogenous circadian rhythms. The promoter regions of Km-BMAL1, -Cry1, -Cry2, and -Per2 were found to contain several xenobiotic response elements (XREs), indicating that EDCs may be able to alter the expression of these genes. To analyze the endogenous circadian rhythm in K. marmoratus, we measured expression of Km-clock and other circadian rhythmic genes (e.g. Per2, Cry1, Cry2, and BMAL1) in different tissues, and found ubiquitous expression, although there were different patterns of transcript amplification during different developmental stages. In an estrogen (E2)-exposed group, Km-clock expression was down-regulated, however, a hydroxytamoxifen (TMX, nonsteroid estrogen antagonist)-exposed group showed an upregulated pattern of Km-clock expression, suggesting that the expression of Km-clock is closely associated with exposure to EDCs. In response to the exposure of bisphenol A (BPA) and 4-tert-octyphenol (OP), Km-clock expression was down-regulated in the pituitary/brain, muscle, and skin in both gender types (hermaphrodite and secondary male). In juvenile K. marmoratus liver tissue, expression of Km-clock and other circadian rhythmic pathway

  17. First record of non-native hybrid catfish Pseudoplatystoma reticulatum × Leiarius marmoratus in the Upper Paraná River basin, Brazil.

    Science.gov (United States)

    Yabu, M H S; Vidotto-Magnoni, A P; Casimiro, A C R; Garcia, D A Z; Costa, A D A; Prado, F D D; Porto-Foresti, F; Orsi, M L

    2018-01-01

    The aim of this study is to report the presence of a three non-native hybrid long-whiskered catfishes (family Pimelodidae) in the Upper Paraná River basin, Brazil. Genetic analyses demonstrated that the three presumptive hybrids were a result of the crossbreeding of Pseudoplatystoma reticulatum (central Amazonas River basin and Lower Paraná River) and Leiarius marmoratus (Amazonas, Essequibo and Orinoco rivers), producing a hybrid commonly known in Brazil as cachandiá. The potential threat to biodiversity, due to possible genetic contamination, competition and predation of wild stocks, of such artificially produced hybrid fishes is discussed. © 2017 The Fisheries Society of the British Isles.

  18. Use of eugenol in Jundiá da Amazônia (Leiarius marmoratus: effects on sedation and evaluation hemogasometry

    Directory of Open Access Journals (Sweden)

    Claucia Aparecida Honorato

    2014-10-01

    Full Text Available This work aims to evaluate the use of eugenol as an anesthetic for jundiá da Amazônia (Leiarius marmoratus, measuring the time to anesthesia induction in different concentrações and their effects in gas exchange. The results were analyzed according to a completely randomized design (DIC with eight treatments (control, 10, 20, 40, 80, 120, 150, 200 mg L-1 of eugenol and ten repetitions. Time values of anesthetic induction and recovery, according to the level of eugenol underwent polynomial regression (p<0.05. The analysis of variance (ANOVA and averages were compared by Tukey test. Were determined the time of anesthesia and recovery. The parameters were analyzed blood glucose, pH, partial pressure of oxygen (PaO2, partial pressure of carbon dioxide (PaCO2, concentration of bicarbonate (HCO-3, sodium (Na, potassium (K, calcium (Ca and chloride (Cl. The concentrations of 40 and 80 mg.L-1 of eugenol were the ones who presented time deep anesthesia induction of 59.5 ± 17.5 sec. and 58.4 ± 18.6 sec. respectively. The concentrations above 120 mg. L-¹ presented mortality. These fish subjected to different level of eugenol did not show changes in blood oxygen pressure (PaO2 and carbon dioxide (PaCO2. The fish when subjected to concentrations above 80 mg L-1 showed an increase of bicarbonate. The plasma glucose values showed significant elevation in response to the bath with anesthetic eugenol. The concentrations of sodium, chloride, potassium and plasma protein remained constants indicating that the process of anesthesia was not long lasting enough to induce changes in the electrolyte balance. Within the conditions of this study, it can be concluded that eugenol is a suitable anesthetic for the silver. This product may be used at a concentration of 40 mg. L-1 without causing changes hemogasométrica.

  19. Invasion rate and population characteristics of the invasive round goby Neogobius melanostomus: effects of density and invasion history

    DEFF Research Database (Denmark)

    Azour, Farivar; Deurs, Mikael van; Behrens, Jane

    2015-01-01

    ). The established population revealed a broad age distribution and a 1:1 gender ratio, while fish from a recently invaded site were primarily of intermediate ages with a male-biased gender ratio. Otolith analyses suggested that the oldest individuals from the recently invaded area experienced superior growth...... Baltic Sea. Further analyses showed that fish from an established high-density round goby population were slow-growing and displayed poorer condition (weight at age and hepatosomatic index) compared to fish sampled from recently invaded locations (i.e. at the forefront of the distribution range......Round goby Neogobius melanostomus is currently one of the most wide-ranging invasive fish species in Europe and North America. The present study demonstrates how the distribution of round goby has expanded from 2008 to 2013 at a rate of about 30 km yr−1 along the Danish coastline in the western...

  20. Environmental DNA (eDNA): A tool for quantifying the abundant but elusive round goby (Neogobius melanostomus)

    Science.gov (United States)

    Nevers, Meredith; Byappanahalli, Muruleedhara; Morris, Charles C.; Shively, Dawn; Przybyla-Kelly, Katarzyna; Spoljaric, Ashley M.; Dickey, Joshua; Roseman, Edward

    2018-01-01

    Environmental DNA (eDNA) is revolutionizing biodiversity monitoring, occupancy estimates, and real-time detections of invasive species. In the Great Lakes, the round goby (Neogobius melanostomus), an invasive benthic fish from the Black Sea, has spread to encompass all five lakes and many tributaries, outcompeting or consuming native species; however, estimates of round goby abundance are confounded by behavior and habitat preference, which impact reliable methods for estimating their population. By integrating eDNA into round goby monitoring, improved estimates of biomass may be obtainable. We conducted mesocosm experiments to estimate rates of goby DNA shedding and decay. Further, we compared eDNA with several methods of traditional field sampling to compare its use as an alternative/complementary monitoring method. Environmental DNA decay was comparable to other fish species, and first-order decay was lower at 12°C (k = 0.043) than at 19°C (k = 0.058). Round goby eDNA was routinely detected in known invaded sites of Lake Michigan and its tributaries (range log10 4.8–6.2 CN/L), but not upstream of an artificial fish barrier. Traditional techniques (mark-recapture, seining, trapping) in Lakes Michigan and Huron resulted in fewer, more variable detections than eDNA, but trapping and eDNA were correlated (Pearson R = 0.87). Additional field testing will help correlate round goby abundance with eDNA, providing insight on its role as a prey fish and its impact on food webs.

  1. Spatial variability and stocks of soil organic carbon in the Gobi desert of Northwestern China.

    Directory of Open Access Journals (Sweden)

    Pingping Zhang

    Full Text Available Soil organic carbon (SOC plays an important role in improving soil properties and the C global cycle. Limited attention, though, has been given to assessing the spatial patterns and stocks of SOC in desert ecosystems. In this study, we quantitatively evaluated the spatial variability of SOC and its influencing factors and estimated SOC storage in a region (40 km2 of the Gobi desert. SOC exhibited a log-normal depth distribution with means of 1.6, 1.5, 1.4, and 1.4 g kg(-1 for the 0-10, 10-20, 20-30, and 30-40 cm layers, respectively, and was moderately variable according to the coefficients of variation (37-42%. Variability of SOC increased as the sampling area expanded and could be well parameterized as a power function of the sampling area. Significant correlations were detected between SOC and soil physical properties, i.e. stone, sand, silt, and clay contents and soil bulk density. The relatively coarse fractions, i.e. sand, silt, and stone contents, had the largest effects on SOC variability. Experimental semivariograms of SOC were best fitted by exponential models. Nugget-to-sill ratios indicated a strong spatial dependence for SOC concentrations at all depths in the study area. The surface layer (0-10 cm had the largest spatial dependency compared with the other layers. The mapping revealed a decreasing trend of SOC concentrations from south to north across this region of the Gobi desert, with higher levels close to an oasis and lower levels surrounded by mountains and near the desert. SOC density to depths of 20 and 40 cm for this 40 km2 area was estimated at 0.42 and 0.68 kg C m(-2, respectively. This study provides an important contribution to understanding the role of the Gobi desert in the global carbon cycle.

  2. Invasion genetics of the Eurasian round goby in North America: tracing sources and spread patterns.

    Science.gov (United States)

    Brown, Joshua E; Stepien, Carol A

    2009-01-01

    The Eurasian round goby Neogobius melanostomus (Apollonia melanostoma) invaded the North American Great Lakes in 1990 through ballast water, spread rapidly, and now is widely distributed and moving through adjacent tributaries. We analyse its genetic diversity and divergence patterns among 25 North American (N = 744) and 22 Eurasian (N = 414) locations using mitochondrial DNA cytochrome b gene sequences and seven nuclear microsatellite loci in order to: (i) identify the invasion's founding source(s), (ii) test for founder effects, (iii) evaluate whether the invasive range is genetically heterogeneous, and (iv) determine whether fringe and central areas differ in genetic diversity. Tests include F(ST) analogues, neighbour-joining trees, haplotype networks, Bayesian assignment, Monmonier barrier analysis, and three-dimensional factorial correspondence analysis. We recovered 13 cytochrome b haplotypes and 232 microsatellite alleles in North America and compared these to variation we previously described across Eurasia. Results show: (i) the southern Dnieper River population was the primary Eurasian donor source for the round goby's invasion of North America, likely supplemented by some alleles from the Dniester and Southern Bug rivers, (ii) the overall invasion has high genetic diversity and experienced no founder effect, (iii) there is significant genetic structuring across North America, and (iv) some expansion areas show reduced numbers of alleles, whereas others appear to reflect secondary colonization. Sampling sites in Lake Huron's Saginaw Bay and Lake Ontario significantly differ from all others, having unique alleles that apparently originated from separate introductions. Substantial genetic variation, multiple founding sources, large number of propagules, and population structure thus likely aided the goby's ecological success.

  3. Bigger is better: characteristics of round gobies forming an invasion front in the Danube river.

    Directory of Open Access Journals (Sweden)

    Joerg Brandner

    Full Text Available Few studies have systematically investigated differences in performance, morphology and parasitic load of invaders at different stages of an invasion. This study analyzed phenotype-environment correlations in a fish invasion from initial absence until establishment in the headwater reach of the second largest European river, the Danube. Here, the round goby (Neogobius melanostomus formed 73% of the fish abundance and 58% of the fish biomass in rip-rap bank habitats after establishment. The time from invasion until establishment was only about two years, indicating rapid expansion. Founder populations from the invasion front were different from longer established round goby populations in demography, morphology, feeding behaviour, sex ratio and parasitic load, indicating that plasticity in these traits determines invasion success. Competitive ability was mostly dependent on growth/size-related traits rather than on fecundity. As revealed by stable isotope analyses, specimens at the invasion front had a higher trophic position in the food web and seem to benefit from lower food competition. Somatic performance seems to be more important than investment in reproduction during the early stages of the invasion process and upstream-directed range expansion is not caused by out-migrating weak or juvenile individuals that were forced to leave high density areas due to high competition. This mechanism might be true for downstream introductions via drift. Greater abundance and densities of acanthocephalan endoparasites were observed at the invasion front, which contradicts the expectation that invasion success is determined by lower parasitic pressure in newly invaded areas. Overall, the pronounced changes in fish and invertebrate communities with a dominance of alien species suggest invasional meltdown and a shift of the upper Danube River towards a novel ecosystem with species that have greater resistance to goby predation. This seems to contribute to

  4. Size Dependent Male Reproductive Tactic in the Two-Spotted Goby (Gobiusculus flavescens).

    Science.gov (United States)

    Utne-Palm, A C; Eduard, K; Jensen, K H; Mayer, I; Jakobsen, P J

    2015-01-01

    Male investment in testes and sperm duct gland in the polygamous nest breeding two-spotted goby Gobiusculus flavescens (Fabricius) was investigated in relation to time in reproductive season and individual physical parameters. This small teleost fish is most likely the most abundant species found along the rocky shores of the North East Atlantic. The two-spotted goby has a single reproductive season, during which nest-caring males can raise several clutches of offspring. According to the literature the males are on average larger than the females. Here we report for the first time a population showing a reversal of this trend, with males on average being smaller than females, a difference likely caused by a large proportion of small males. Early in the breeding season these small males have typical sneaker characters, with relatively large testes and small seminal duct glands compared to the larger dominant territorial males. The presence of these two alternative male reproductive tactics is confirmed by histological studies, which shows the presence of sperm in the sperm duct glands (SDG) of smaller males, but not in the SDG of intermediate and larger males. To our knowledge, males with typical sneaker characters have not been reported in earlier studied populations of two-spotted goby. Interestingly we found that testes investment declined significantly over the course of the breeding season, and that this reduction was significantly more pronounced in small compared to the large males. Further, a significant increase in seminal duct gland (SDG) mass was observed for the smaller males over the breeding season. We propose that this indicates a possible shift in mating tactic by smaller males from a parasitic to a nest-holding tactic over the course of the breeding season. Thus, the observed size dependent plasticity in investment in SDG over time suggests that the reproductive tactic of G. flavescens is conditional, and possibly influenced by mate availability and

  5. Environmental conditions and soils of natural oases in the Alashan Gobi Desert, Mongolia

    Science.gov (United States)

    Pankova, E. I.

    2008-08-01

    Environmental conditions and soils of nine natural oases in the Alashan Gobi Desert of Mongolia are characterized. All these oases are allocated to the zones of tectonic faults, where the discharge of slightly saline groundwater takes place. The absolute heights are about 1500 m a.s.l. The oases are found on piedmont plains or in hilly areas occupied by true deserts with fragments of extremely arid deserts. With respect to geomorphological conditions, four types of oases can be distinguished: isolated (isle-type) oases, oases in large mesodepressions, oases formed in naturally ponded areas, and oases within terraced valleys. Each of these types is characterized by specific soil cover patterns controlled by the geomorphological features of the territory, the character of parent materials, and the groundwater depth. At the same time, some common soil properties are typical of all the oases. Hydromorphic soils—peat meadow-swampy soils, dark-colored nonsaline meadow soils, oasis solonchaks that developed in areas with shallow nonsaline groundwater, solonchaks with different degrees of hydromorphism that developed from mottled-colored salt-bearing Cretaceous and Paleogene deposits, and soddy alluvial (floodplain) soils—predominate in the central parts of the oases. Under conditions of deep groundwater, takyric and sandy desert soils are formed. The oases are encircled by desert ecosystems with gray-brown desert and extremely arid soils and with poorly developed stony soils that formed on the low residual mounts. In the period of the study (1991), irrigated farming was only developed within one of the studied oases. The main part of the land was used for pasturing. In some cases, the high grazing pressure led to degradation (desertification) of oasis ecosystems. A comparison of the oases studied in the Alashan Gobi with the Ekhiin-Gol oasis in the Transaltai Gobi attests to the similarity of their nature.

  6. Size Dependent Male Reproductive Tactic in the Two-Spotted Goby (Gobiusculus flavescens.

    Directory of Open Access Journals (Sweden)

    A C Utne-Palm

    Full Text Available Male investment in testes and sperm duct gland in the polygamous nest breeding two-spotted goby Gobiusculus flavescens (Fabricius was investigated in relation to time in reproductive season and individual physical parameters. This small teleost fish is most likely the most abundant species found along the rocky shores of the North East Atlantic. The two-spotted goby has a single reproductive season, during which nest-caring males can raise several clutches of offspring. According to the literature the males are on average larger than the females. Here we report for the first time a population showing a reversal of this trend, with males on average being smaller than females, a difference likely caused by a large proportion of small males. Early in the breeding season these small males have typical sneaker characters, with relatively large testes and small seminal duct glands compared to the larger dominant territorial males. The presence of these two alternative male reproductive tactics is confirmed by histological studies, which shows the presence of sperm in the sperm duct glands (SDG of smaller males, but not in the SDG of intermediate and larger males. To our knowledge, males with typical sneaker characters have not been reported in earlier studied populations of two-spotted goby. Interestingly we found that testes investment declined significantly over the course of the breeding season, and that this reduction was significantly more pronounced in small compared to the large males. Further, a significant increase in seminal duct gland (SDG mass was observed for the smaller males over the breeding season. We propose that this indicates a possible shift in mating tactic by smaller males from a parasitic to a nest-holding tactic over the course of the breeding season. Thus, the observed size dependent plasticity in investment in SDG over time suggests that the reproductive tactic of G. flavescens is conditional, and possibly influenced by mate

  7. The use of rockfish Sebastiscus marmoratus as a sentinel species to assess petroleum hydrocarbons pollution: A case study in Quanzhou Bay, China.

    Science.gov (United States)

    Bo, Jun; Zheng, Ronghui; Kuang, Weiming; Hong, Fukun; Xie, Qing; Zhang, Yusheng

    2017-11-30

    To monitor the biological effects of marine pollution, choosing a native fish species and establishing suitable biomarkers are required. In this study, the full-length cDNA of cyp1a1 was cloned from Sebastiscus marmoratus (SM-CYP1A1). Then the dose-response and time-course induction of hepatic CYP1A1 mRNA by the crude oil water-soluble fraction (WSF) were determined. Subsequently, SM-CYP1A1 mRNA was applied to investigate the biological effect of petroleum hydrocarbon pollution in Quanzhou Bay, China. The transcription levels of hepatic CYP1A1 were significantly elevated in fish caged in the polluted sites for 2weeks compared with those of the reference site, which were correlated with the concentrations of petroleum hydrocarbon and polycyclic aromatic hydrocarbon (PAH) in the surface seawaters. The results suggest that S. marmoratus is a potential sentinel organism to monitor marine pollutants and the hepatic CYP1A1 mRNA can serve as a sensitive biomarker to organic xenobiotics in aquatic environments. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. The fine structure of the sperm of the round goby (Neogobius melanostomus)

    Science.gov (United States)

    Allen, Jeffrey D.; Walker, Glenn K.; Nichols, Susan J.; Sorenson, Dorothy

    2004-01-01

    The fine structural details of the spermatozoon of the round goby are presented for the first time in this study. Scanning and transmission electron microscopic examination of testis reveals an anacrosomal spermatozoon with a slightly elongate head and uniformly compacted chromatin. The midpiece contains a single, spherical mitochondrion. Two perpendicularly oriented centrioles lie in a deep, eccentric nuclear fossa with no regularly observed connection to the nucleus. The flagellum develops bilateral fins soon after emerging from the fossa; each extends approximately 1 A?m from the axoneme and persists nearly the length of the flagellum.

  9. Description of a small goby, Trimma grammistes (Perciformes: Gobiidae), from Jeju Island, Korea

    Science.gov (United States)

    Kim, Byung Jik; Choi, Seung-Ho; Kim, Sung

    2013-06-01

    A small goby, Trimma grammistes, was described in detail as the first reliable record from Korea based on 10 specimens (27.8˜34.0 mm SL) collected from the coastal waters of Jeju Island. The species is easily differentiated from congeners by having no scales on the predorsal region, VI-I, 10 dorsal fin rays modally, I, 10 anal fin rays, 18 pectoral fin rays, 27˜30 longitudinal scales as well as two dark longitudinal bands on the body.

  10. The specificities of round goby fecundity (Neogobius melanostomus in different ecological conditions

    Directory of Open Access Journals (Sweden)

    M. Tkachenko

    2013-12-01

    Full Text Available We conducted a comparative analysis of the absolute and relative fecundity of round goby (Neogobius melanostomus (Pallas, 1984 females in the Kakhovskyy Reservoir and the Azov Sea. We analysed the indicators of salinity, pH and oxygen levels in the waterbodies investigated. We determined the dependence of fertility of round gobies on body weight, length and age. This article presents the results of a comparative analysis with the works of other authors, including the results of a similar study conducted 40-years ago. We conducted cameral processing of the results by standard methodology. We counted the oocytes at varying stages of maturity. All oocytes were grouped by their diameter. We visually identified four groups of oocytes: 1700–2500 mkm – the large, mature oocytes (ІV stage of maturity; 400–1200 mkm – light yellow oocytes, which are ripening (ІІІ stage; 100–300 mkm (ІІ stage whitish eggs, and the smallest (I stage – up to 100 mkm. Stages II–IV were subjected to statistical processing. The differences between the indicators of fertility of fishes from saltwater and freshwater waterbodies show an increase in the relative and the absolute fecundity of fishes from the sea (saltwater and decrease in the fecundity of the fishes in freshwater. The correlation analysis between the waterbodies and the length of the fishes showed 0.81 at the Kahovskyy Reservoir and0.62 in theAzovSea. The correlation analysis between the same waterbodies and the weight of the fishes was 0.63 and 0.74 respectively. This could indicate that conditions for the fishes’ existence were more favourable in the sea. The comparison analysis between our data and the 40-year old data for theAzovSea depending on length and weight show a significant increase in oocyte numbers. This increase was noted for all size groups of fish. Nevertheless, the greatest differences were between fish in theAzovSea (all data and those in the Kahovskyy Reservoir. These

  11. Chaque goutte compte – entrevue de Gabin Koto N'Gobi, boursier ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    11 mai 2012 ... C'est la pénurie d'eau dans la région semi-aride dans le nord de son pays natal, le Bénin, qui est sa véritable motivation. Dans le cadre de ses études de doctorat à l'Université d'Abomey-Calavi, M. Koto N'Gobi a mis au point un procédé de récolte de la rosée – un prototype si novateur dans la région qu'il ...

  12. Extirpation and recolonization in a metapopulation of an endangered fish, the tidewater goby

    Science.gov (United States)

    Lafferty, K.D.; Swift, C.C.; Ambrose, R.F.

    1999-01-01

    The tidewater goby (Eucyclogobius newberryi), an endangered species in the United States, occurs in a series of isolated coastal wetlands in California. Using historical presence-absence data and our own surveys, we estimated annual rates of extirpation and recolonization for several populations of the goby in southern California. As predicted, large wetlands had lower rates of extirpation than small wetlands. There was a negative but statistically nonsignificant correlation between recolonization rate and distance to the nearest northerly source population. Populations at small sites were sensitive to drought, presumably because droughts can eliminate suitable habitat at small wetlands. Populations in small wetlands have declined over time, even after accounting for variation in stream flow, supporting the species' endangered status. Our study emphasizes the need to understand metapopulation dynamics for conserving species where the unit of conservation is a local population. It is also emphasizes the importance of not treating metapopulations as identical units. Finally, our results provide a means for describing the decline of a species that is complex in time and space and provide insight into how to target protection measures among metapopulations.

  13. Biology of the Sanzo's goby, Lesueurigobius sanzoi (de Buen, 1918, off Cabo Raso, Portugal

    Directory of Open Access Journals (Sweden)

    Cristina Paulo Martins

    2004-06-01

    Full Text Available The presence of Sanzos's goby, Lesueurigobius sanzoi (de Buen, 1918, off Cabo Raso, Portugal, is recorded for the first time. The biology of this population was studied using 11 samples collected between April 2000 and September 2001 at depths of 70-100 m on muddy and sandy bottoms. The females reach a standard length of 110 mm and the males 103 mm. It attains an age of 24 months, which equals two breeding seasons. The otoliths form two translucent rings each year, which corresponds to the winter growth and the reproduction period. Sanzo's gobies can be classified as prematur and standard individuals, according to whether the first breeding occurs before or after the first winter respectively. Standard individuals, which have an extended first growth, reach a longer length than prematur individuals, whose first growth is much shorter. Although discrete, sexual dimorphism was noticeable even outside the spawning season. The breeding season occurs between May and September/October with more than one spawning. The minimum length for which the maturity stage occurs is 64 mm, at an age of 0+. The feeding activity is quite constant throughout the year, and the diet consists predominantly of small crustacea and molluscs, although polychaets also feature commonly in its diet.

  14. Body size correlates with fertilization success but not gonad size in grass goby territorial males.

    Directory of Open Access Journals (Sweden)

    Jose Martin Pujolar

    Full Text Available In fish species with alternative male mating tactics, sperm competition typically occurs when small males that are unsuccessful in direct contests steal fertilization opportunities from large dominant males. In the grass goby Zosterisessor ophiocephalus, large territorial males defend and court females from nest sites, while small sneaker males obtain matings by sneaking into nests. Parentage assignment of 688 eggs from 8 different nests sampled in the 2003-2004 breeding season revealed a high level of sperm competition. Fertilization success of territorial males was very high but in all nests sneakers also contributed to the progeny. In territorial males, fertilization success correlated positively with male body size. Gonadal investment was explored in a sample of 126 grass gobies collected during the period 1995-1996 in the same area (61 territorial males and 65 sneakers. Correlation between body weight and testis weight was positive and significant for sneaker males, while correlation was virtually equal to zero in territorial males. That body size in territorial males is correlated with fertilization success but not gonad size suggests that males allocate much more energy into growth and relatively little into sperm production once the needed size to become territorial is attained. The increased paternity of larger territorial males might be due to a more effective defense of the nest in comparison with smaller territorial males.

  15. Population and reproductive characteristics of a non-native western tubenose goby (Proterorhinus semilunaris) population unaffected by gobiid competitors

    Czech Academy of Sciences Publication Activity Database

    Valová, Zdenka; Konečná, Markéta; Janáč, Michal; Jurajda, Pavel

    2015-01-01

    Roč. 10, č. 1 (2015), s. 57-68 ISSN 1798-6540 R&D Projects: GA ČR(CZ) GAP505/11/1768 Institutional support: RVO:68081766 Keywords : Gobiidae * invasive species * non- indigenous * tubenose goby * population dynamics Subject RIV: EH - Ecology, Behaviour Impact factor: 1.955, year: 2015

  16. Response of benthic macroinvertebrate assemblages to round (Neogobius melanostomus, Pallas 1814) and tubenose (Proterorhinus semilunaris, Heckel 1837) goby predation pressure

    Czech Academy of Sciences Publication Activity Database

    Mikl, Libor; Adámek, Zdeněk; Všetičková, Lucie; Janáč, Michal; Roche, Kevin Francis; Šlapanský, Luděk; Jurajda, Pavel

    2017-01-01

    Roč. 785, č. 1 (2017), s. 219-232 ISSN 0018-8158 R&D Projects: GA ČR(CZ) GAP505/11/1768 Institutional support: RVO:68081766 Keywords : Invasive species * Gobies * Macroinvertebrates * Impact * European rivers * Diet Subject RIV: EH - Ecology, Behaviour OBOR OECD: Marine biology, freshwater biology, limnology Impact factor: 2.056, year: 2016

  17. Population structure, condition, and reproduction characteristics of native monkey goby, Neogobius fluviatilis (Actinopterygii: Perciformes Gobiidae), in the Bulgarian Danube

    Czech Academy of Sciences Publication Activity Database

    Konečná, Markéta; Jurajda, Pavel

    2012-01-01

    Roč. 42, č. 4 (2012), s. 321-327 ISSN 0137-1592 R&D Projects: GA ČR(CZ) GAP505/11/1768 Institutional support: RVO:68081766 Keywords : monkey goby * invasion * Bulgaria * Danube, condition * GSI * ovary structure Subject RIV: EH - Ecology, Behaviour Impact factor: 0.606, year: 2012

  18. Predation on parasitic gnathiid isopods on coral reefs: a comparison of Caribbean cleaning gobies with non-cleaning microcarnivores

    Science.gov (United States)

    Artim, John M.; Hook, Alexandra; Grippo, Richard S.; Sikkel, Paul C.

    2017-12-01

    On coral reefs, gnathiid isopods are a common blood-feeding ectoparasite of reef fishes that can have significant impacts on reef-fish health and fitness. Cleaner fishes and shrimps are the only major documented predators of gnathiids, removing them from the bodies of host fishes. However, gnathiids spend most of their lifecycle free living and thus may be eaten by other microcarnivorous fishes that collectively could have larger impacts on gnathiid populations. This study examined gut contents from Caribbean nocturnal reef microcarnivorous fish and from the Caribbean cleaning goby Elacatinus evelynae for the presence of gnathiid isopods. Among nocturnal microcarnivores, gnathiids were found in only a small proportion of the gut contents of grunts (5%) and cardinalfish (4%), but in a higher proportion of the gut contents of squirrelfish and soldierfish (26%). In comparison, most cleaning gobies collected in the morning had gnathiids (93%), with an average of 6.3 gnathiids per fish. While microcarnivorous fishes ate far fewer gnathiids, they were present in much greater numbers than cleaning gobies. These results support previous studies on cleaning gobies suggesting that individually, they consume high numbers of gnathiids. However, they also suggest that collectively, other predators could have an equal or greater impact on gnathiid populations.

  19. Zebra mussel beds: an effective feeding ground for Ponto-Caspian gobies or suitable shelter for their prey?

    Directory of Open Access Journals (Sweden)

    Jarosław Kobak

    2016-11-01

    Full Text Available Aggregations of the Ponto-Caspian invasive zebra mussel (Dreissena polymorpha constitute a suitable habitat for macroinvertebrates, considerably increasing their abundance and providing effective antipredator protection. Thus, the overall effect of a mussel bed on particular predator species may vary from positive to negative, depending on both prey density increase and predator ability to prey in a structurally complex habitat. Alien Ponto-Caspian goby fish are likely to be facilitated when introduced into new areas by zebra mussels, provided that they are capable of utilizing mussel beds as habitat and feeding grounds. We ran laboratory experiments to find which prey (chironomid larvae densities (from ca. 500 to 2,000 individuals m−2 in a mussel bed make it a more beneficial feeding ground for the racer goby Babka gymnotrachelus (RG and western tubenose goby Proterorhinus semilunaris (WTG compared to sandy and stone substrata (containing the basic prey density of 500 ind. m−2. Moreover, we checked how food availability affects habitat selection by fish. Mussel beds became more suitable for fish than alternative mineral substrata when food abundance was at least two times higher (1,000 vs. 500 ind. m−2, regardless of fish size and species. WTG was associated with mussel beds regardless of its size and prey density, whereas RG switched to this habitat when it became a better feeding ground than alternative substrata. Larger RG exhibited a stronger affinity for mussels than small individuals. WTG fed more efficiently from a mussel bed at high food abundances than RG. A literature review has shown that increasing chironomid density, which in our study was sufficient to make a mussel habitat an attractive feeding ground for the gobies, is commonly observed in mussel beds in the field. Therefore, we conclude that zebra mussels may positively affect the alien goby species and are likely to facilitate their establishment in novel areas

  20. (Hyperolius marmoratus) populations

    African Journals Online (AJOL)

    population differentiation among ..... 13: 121-177. RICHARDS. C.M. & MOORE. W.S. 1996. A phylogeny for the. African tree frog family Ilyperoliidne based on mitochondrial. rONA. Mol. Phyl. Evol. 5(3): 522-532. SELANDER. R.K. & KAlJFMAN.

  1. Feeding of Marbled Goby, Oxyeleotris marmorata (Blkr., Larvae in the Two Weeks of Their Early Life

    Directory of Open Access Journals (Sweden)

    Irzal Effendi

    2007-12-01

    Full Text Available ABSTRACTThe experiment was carried out at the Laboratory of Aquaculture System and Technology, Faculty of Fisheries, Institut Pertanian Bogor, Bogor. Factorial arrangement in randomised block design was used in this experiment with two factors: kind of feed and feed density for sand goby, Oxyeleotris marmorata (Blkr. larvae. There were 3 kinds of feed: rotifer, enriched-rotifer, and egg yolk-premix. Rotifer density of 20, 30, and 40 individuals/ml were maintained troughout the experiment. Egg yolk-premix were given per day in equivalent quantity as those rotifers in the treatment. Larvae of 40 individuals/l were kept in the 250 l plastic tanks, filled with 200 l of aerated ground water for 15 days indoor. Larvae fed rotifer showed better survival and growth rate than those fed egg yolk-premix. Increased rotifer density tended to increase survival and growth rate of larvae.Key words :  marbled goby, Oxyeleotris marmorata, larvae, feeding, rotifers ABSTRAKPercobaan ini dilakukan di Kolam Percobaan Babakan, Laboratorium Bogor, Bogor, dan dirancang berbentuk factorial dalam rancangan acak kelompok, dengan faktor: (1 jenis pakan dan (2 kepadatan pakan. Jenis pakan dibedakan menjadi: rotifera, rotifera-diperkaya, dan kuning telur-premiks, sedangkan kepadatan rotifera dibedakan menjadi : 20,30, dan 40 individu/ml, dipertahankan setiap hari. Kuning telur-premiks diberikan kepada larva ikan betutu, Oxyeleotris marmorata setiap hari yang setara dengan bobot rotifera setiap perlakuan, berdasarkan bobot kering keduanya. Larva sebanyak 40 ekor/l dipelihara dalam tangki plastik bervolume 250 l yang diisi air 200 l selama 15 hari dalam ruangan. Larva yang diberi rotifera cenderung memiliki kelangsungan hidup dan pertumbuhan lebih besar daripada kuning telur-premiks. Kepadatan rotifera yang semakin tinggi cenderung dapat meningkatkan kelangsungan hidup dan pertumbuhan larva.Kata kunci :  ikan betutu, Oxyeleotris marmorata, larva, pemberian pakan, rotifera

  2. The Gyrodactylus (Monogenea, Gyrodactylidae) parasite fauna of freshwater sand gobies (Teleostei, Gobioidei) in their centre of endemism, with description of seven new species.

    Science.gov (United States)

    Vanhove, Maarten P M; Economou, Alcibiades N; Zogaris, Stamatis; Giakoumi, Sofia; Zanella, Davor; Volckaert, Filip A M; Huyse, Tine

    2014-02-01

    While Gobioidei comprises showcases of (adaptive) radiation, the scientific interest they yielded did not ensure full understanding of goby biodiversity. Even in a well-studied region like Europe, wide knowledge gaps remain. Sand gobies represent one of the few clades whose monogenean parasites have been thoroughly studied. However, in the Balkans, part of the sand gobies' centre of endemism, these parasites were unstudied. We focus on Greek and Croatian freshwater gobies. From five sand goby species, the first parasites are reported, describing seven new Gyrodactylus species. Economidichthys pygmaeus harbours Gyrodactylus benedeni sp. n. and Gyrodactylus dorlodoti sp. n. Its congener E. trichonis hosts G. meelkopae sp. n. Knipowitschia milleri was found to host G. charon sp. n., K. thessala is infected by G. bios sp. n., and K. croatica by G. douglasadamsi sp. n. and G. hellemansi sp. n. Gyrodactylus bubyri was found on its type host K. caucasica. A diverse parasite fauna is expected for a region known for its biodiversity and endemism. The contribution of parasites to species richness in such hotspots is overlooked. The observed species richness per host is rather low compared to the better-studied eastern Atlantic sand gobies. Host vicariance is considered to mediate parasite specificity in this fauna. Some new flatworm species display unique morphological features, such as the remarkable size of the marginal hook sickle proper compared to its foot in the Economidichthys parasites, or a characteristically kinked marginal hook sickle in G. douglasadamsi sp. n. These features reflect their hosts' endemism in the Balkans.

  3. An Evaluation of Investment in a PV Power Generation Project in the Gobi Desert Using a Real Options Model

    OpenAIRE

    Yiqing Li; Weiguo Yang; Lixin Tian; Jie Yang

    2018-01-01

    This paper presents a policy benefit model of a photovoltaic (PV) power generation project based on real options analysis (ROA) and the two-factor learning curve model. The main purpose is to examine the investment behavior of developing a PV project in the Gobi desert considering multiple uncertain factors. We take the environmental cost of desertification control into account for the first time in the literature. Four other uncertain factors are thermal power cost, PV power generation cost,...

  4. First record of the blackfin coral goby, Paragobiodon lacunicolus (Kendall and Goldsborough, 1911), from the Red Sea

    KAUST Repository

    Alpermann, Tilman J.

    2013-09-13

    Three specimens of the blackfin coral goby, Paragobiodon lacunicolus, were collected in 2010 and 2011 at different locations of the eastern Red Sea along the coast of Saudi Arabia. Reexamination of 14 museum specimens from Eritrea also confirmed the presence of the species for the western Red Sea. This represents the first published report of P. lacunicolus from the Red Sea. © 2013 Blackwell Verlag GmbH.

  5. Measurements of the surface energy budget in the southern Gobi Desert of China, and in the Rocky Mountains of Colorado

    Science.gov (United States)

    Reiter, E. R.; Smith, E. A.; Sheaffer, J. D.

    1985-01-01

    Observations of the land surface energy balance were made in the Gobi desert and at two mountain sites in northern Colorado. The Gobi study included 12 days of observations in spring (April 8 to 20, 1984) and 31 days in summer at the same site (June 17 to July 18, 1984). The Colorado study included 126 days (March 13 to July 17, 1984) at a valley site and 34 days (July 31 to September 3, 1984) at a mountain top location. The data for each study included continuous observations of upward and downward radiative fluxes in three wave bands, soil temperature and moisture at four levels, air temperature and humidity at four levels and UVW wind components at three levels. Analyses of the Gobi data include definition of the impact of variable atmospheric moisture on the surface energy balance between spring and summer. In addition, diurnal wind circulations forced by heating of the northern edge of the Tibetan Plateau were observed during both periods.

  6. An evaluation of behavioural endpoints: The pharmaceutical pollutant fluoxetine decreases aggression across multiple contexts in round goby (Neogobius melanostomus).

    Science.gov (United States)

    McCallum, Erin S; Bose, Aneesh P H; Warriner, Theresa R; Balshine, Sigal

    2017-05-01

    Fluoxetine (Prozac™) is designed to alter human behaviour; however, because many physiological pathways are conserved across vertebrates, this drug may affect the behaviour of fish living in fluoxetine-polluted environments. Although a number of studies have used behaviour to document the sub-lethal effects of fluoxetine, the repeatability of these effects across experiments, across behavioural contexts, and over different exposure durations are rarely considered. Here, we conducted two experiments and assessed how fluoxetine exposure affected a range of fitness-related behaviours in wild round goby (Neogobius melanostomus). We found that fluoxetine impacts round goby behaviour at high (40 μg/l) doses, but not at environmentally relevant low doses (1 μg/l). In both experiments, an acute 3-day exposure to fluoxetine reduced round goby aggression in multiple behavioural contexts, but had no detectable effect on overall activity or social affiliative behaviour. While a chronic 28-day exposure to fluoxetine exposure still reduced aggression, this reduction was only detectable in one behavioural context. Our findings demonstrate the importance of repeated behavioural testing (both between and within experiments) and contribute to a growing body of literature evaluating the effects of fluoxetine and other pharmaceuticals on animal behaviour. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. How old are you—Evaluation of age reading methods for the invasive round goby (Neogobius melanostomus, Pallas 1814)

    DEFF Research Database (Denmark)

    Florin, Ann-Britt; Hüssy, Karin; Blass, M.

    2017-01-01

    In the Baltic, the first observation of the round goby (Neogobius melanostomus, Pallas 1814) was made in 1990. Within the past decade the species became invasive and spread rapidly throughout the Baltic Sea. Studies about the fishes potential impacts on resident species promote the need for an in......In the Baltic, the first observation of the round goby (Neogobius melanostomus, Pallas 1814) was made in 1990. Within the past decade the species became invasive and spread rapidly throughout the Baltic Sea. Studies about the fishes potential impacts on resident species promote the need...... for an increasing knowledge of their basic stock structures such as growth rates, longevity and mortality, which all rely on accurate estimates of age. Former studies on the round goby have used several different age reading techniques. In this study, we compared three standard otolith preparation methods...... agreement was lowest when reading the whole otoliths while the best performance was achieved with sectioned and stained preparation method. Depending on method used the growth estimates also differed. The results question comparability between previous studies and highlight the importance of harmonised...

  8. Cloning of growth hormone, somatolactin, and their receptor mRNAs, their expression in organs, during development, and on salinity stress in the hermaphroditic fish, Kryptolebias marmoratus.

    Science.gov (United States)

    Rhee, Jae-Sung; Kim, Bo-Mi; Seo, Jung Soo; Kim, Il-Chan; Lee, Young-Mi; Lee, Jae-Seong

    2012-04-01

    Salinity is an important parameter that affects survival and metabolism in fish. In fish, pituitary growth hormone (GH) regulates physiological functions including adaptation to different salinity as well as somatic growth. GH is stimulated by growth hormone-releasing hormone (GHRH) and exerts its function via binding to growth hormone receptor (GHR). As Kryptolebias marmoratus is a euryhaline fish, this species would be a useful model species for studying the adaptation to osmotic stress conditions. Here, we cloned GH, -GHR, somatolactin (SL), and somatolactin receptor (SLR) genes, and analyzed their expression patterns in different tissues and during early developmental stages by using real-time RT-PCR. We also further examined expression of them after acclimation to different salinity. Tissue distribution studies revealed that Km-GH and -SL mRNAs were remarkably expressed in brain and pituitary, whereas Km-GHR and -SLR mRNAs were predominantly expressed in liver, followed by gonad, muscle, pituitary, and brain. During embryonic developmental stages, the expression of their mRNA was increased at stage 3 (9 dpf). The Km-GH and -SL mRNA transcripts were constantly elevated until stage 5 (5h post hatch), whereas Km-GHR and -SLR mRNA levels decreased at this stage. After we transferred K. marmoratus from control (12 psu) to hyper-osmotic condition (hyperseawater, HSW; 33 psu), Km-GH, -SL, and GHR mRNA levels were enhanced. In hypo-osmotic conditions like freshwater (FW), Km-GH and -SL expressions were modulated 24 h after exposure, and Km-SLR transcripts were significantly upregulated. This finding suggests that Km-GH and -SL may be involved in the osmoregulatory mechanism under hyper-osmotic as well as hypo-osmotic stress. This is the first report on transcriptional modulation and relationship of GH, GHR, SL, and SLR during early development and after salinity stress. This study will be helpful to a better understanding on molecular mechanisms of adaptation response

  9. Enhancing the Survival Rate of Sand Goby, Oxyeleotris marmorata (Blkr., Larvae with Antibiotics

    Directory of Open Access Journals (Sweden)

    Irzal Effendi

    2007-05-01

    Full Text Available ABSTRACTPenicillin G and streptomycin sulphate were administered for 18 days of rearing of sand goby larvae. 7'wo-days larvae (3,37-3,41 mm were reared in 160 1 aerated water at stocking density of 50 fish/1.  Until 17 days of rearing period, the larvae were fed plankton (50-300 gm at stocking density of 20-30 individual/mi, and at day 13-I8, were fed Artemia sp. (1-2 individual/ml.  During first seven days, penicillin G and streptomycin sulphate (1.000 IU/1 and 10 mg/1, respectively were applied daily, and there after once every three days.  The fry which reared in media containing antibiotics exhibited higher survival rate (28,09%, compared to 3,3 1 %, than the control, whereas their growth was similar (1,09-1,53 mm. Keywords :  Antibiotics, survival rate, sand goby fish, Oxyeleotris marmorata  ABSTRAKAntibiotik penisilin G dan streptomisin sulfat telah digunakan dalam pemeliharaan larva ikan betutu selama 18 hari.  Larva umur 2 hari (3,37-3,41 mm dipelihara dalain tangki berisi air sebanyak 160 1 yang diaerasi halus, dengan kepadatan 50 ekor/1.  Antibiotik diberikan kepada media pemeliharaan larva setiap hari pada 7 hari pertarna pemeliharaan dan selanjutnya setiap 3 hari sekaii hingga akhir pemeliharaan, sebanyak 1.000 IU/1 dan 10 mg/1 masing-masing untuk penisilin G dan streptomisin sulfat.  Pada hari pertama hingga ke- 1 7, larva diberi makan plankton berukuran 50-300 gm sebanyak 20-30 individu/ml, hari ke- 13 sampai 18 diberi Artemia sp. sebanyak 1-2 ekor/ml.  Larva yang dipelihara pada media berantibiotik memiliki kelangsungan hidup (28,09% lebih tinggi dibandingkan dengan tanpa antibiotik (3,31%, sedangkan pertumbuhan panjang mutlaknya sama yaitu 1,09-1,53 mm.Kata kunci :  Antibiotik, kelangsungan hidup, ikan betutu, Oxyeleotris marmorata

  10. Malfunction Rates of Bird Flight Diverters on Powerlines in the Mongolian Gobi

    Directory of Open Access Journals (Sweden)

    Batsuuri Dashnyam

    2016-11-01

    Full Text Available The Oyu Tolgoi (OT project, one of the world’s largest copper and gold mines, is located in Gobi Desert of Mongolia. To help meet its target of Net Positive Impact on key biodiversity features such as the Houbara bustard (Chlamydotis undulata the OT installed bird fl ight diverters (BFDs include spiral and fl apper devices to its power transmission lines to reduce the risk of birds hitting the wires. Despite the many studies demonstrating that BFDs reduce collision rates, we could fi nd no published information on malfunction rates of BFDs. In January 2013, we surveyed the physical function of 1,200 BFDs (e.g. 600 fl appers and 600 spirals in three sample areas on each of four lines of varying voltage and structure. Of the 600 fl appers examined, 123 had malfunctioned within nine months of installation, while the malfunction rate of the 600 spirals studied was zero. Using a Generalized Linear Mixed Model, we found that the rate of fl apper malfunction increased with decreasing fl apper size and power line diameter. Further, the fl apper malfunction rate increased as the distance between poles increased. The cost of replacing malfunctioning BFDs is very high as there are serious health and safety constraints related to working with live wires. Factors aff ecting diverter malfunctioning need to be considered for future powerline projects and our information can serve as basis for developing national standards or regulations for powerline mitigation in Mongolia.

  11. Female mate preference in goby Eviota prasina: do secondary sexual traits influence female choice?

    Science.gov (United States)

    Sekiya, Yuko; Karino, Kenji

    2004-08-01

    Males of the small gobiid fish Eviota prasina have longer dorsal fins than females and use their dorsal fins for courtship displays and male-male competition. We examined the influence of male dorsal fin length as well as the frequency of courtship displays on female mate preference using sequential choice experiments. Females responded more frequently to courting males with longer dorsal fins than males with shorter dorsal fins. This indicates female mate preference on the basis of male dorsal fin length in this goby. In addition, the logistic regression analysis showed that male courtship frequency positively influenced female mate preference. Since males incur costs to produce and maintain longer dorsal fins and to perform frequent courtship displays, these secondary sexual traits may indicate the quality of physical characteristics. In E. prasina, only males conducted parental care for eggs in their nests. Therefore, females may be able to ensure greater survival rates as well as higher genetic quality of their offspring by choosing males with better qualities based on these male traits.

  12. Do male desert gobies compromise offspring care to attract additional mating opportunities?

    Directory of Open Access Journals (Sweden)

    Nicholas Symons

    Full Text Available Males often play a critical role in offspring care but the time and energy invested in looking after young can potentially limit their ability to seek out additional mating opportunities. Recent studies, however, suggest that a conflict between male parental effort and mating effort may not always be inevitable, especially if breeding occurs near the nest, or if parental behaviours are under sexual selection. Accordingly, we set out to experimentally investigate male care and courtship in the desert goby Chlamydogobius eremius, a nest-guarding fish with exclusive paternal care. Despite courtship occurring near the nest, we found that when egg-tending males were given the opportunity to attract additional females, they fanned their eggs less often, engaged in shorter fanning bouts, and spent more of their time outside their nests courting. Our findings highlight the importance of understanding the circumstances under which reproductive tradeoffs are expected to occur and how these, in turn, operate to influence male reproductive decisions.

  13. Reproductive biology of the striped goby, Gobius vittatus (Gobiidae in the northern Adriatic Sea

    Directory of Open Access Journals (Sweden)

    Marcelo Kovacic

    2007-03-01

    Full Text Available The striped goby, Gobius vittatus Vinciguerra, 1883 is a Mediterranean gobiid species considered to be rare and lacking in data on its reproduction. Sex ratio, length and age at first maturity, annual cycle of gonad development, spawning period and fecundity of G. vittatus were studied on 704 specimens collected by SCUBA diving in the northern Adriatic Sea (Kvarner area from April 2001 to March 2002. The monthly sex ratio did not differ significantly, except during the spawning season, when it was strongly biased in favour of females. The estimated length at first maturity was 32.8 and 35.4 mm for females and males, respectively. In both sexes gonad development started in the first year of life. All specimens were mature by the third year. The spawning season was from April to July. Total fecundity ranged from 560 to 3045, with an average of 1426 ± 89 ripe eggs/fish. The simultaneous presence of three clearly distinct sizes of oocytes in ripe ovaries indicate that this species is a multiple spawner.

  14. Fungal Ferromanganese Mineralisation in Cretaceous Dinosaur Bones from the Gobi Desert, Mongolia.

    Science.gov (United States)

    Owocki, Krzysztof; Kremer, Barbara; Wrzosek, Beata; Królikowska, Agata; Kaźmierczak, Józef

    2016-01-01

    Well-preserved mycelia of fungal- or saprolegnia-like biota mineralised by ferromanganese oxides were found for the first time in long bones of Late Cretaceous dinosaurs from the Gobi Desert (Nemegt Valley, Mongolia). The mycelia formed a biofilm on the wall of the bone marrow cavity and penetrated the osteon channels of the nearby bone tissue. Optical microscopy, Raman, SEM/EDS, SEM/BSE, electron microprobe and cathodoluminescence analyses revealed that the mineralisation of the mycelia proceeded in two stages. The first stage was early post-mortem mineralisation of the hyphae by Fe/Mn-oxide coatings and microconcretions. Probably this proceeded in a mildly acidic to circumneutral environment, predominantly due to heterotrophic bacteria degrading the mycelial necromass and liberating Fe and Mn sorbed by the mycelia during its lifetime. The second stage of mineralisation, which proceeded much later following the final burial of the bones in an alkaline environment, resulted from the massive precipitation of calcite and occasionally barite on the iron/manganese-oxide-coated mycelia. The mineral phases produced by fungal biofilms colonising the interiors of decaying dinosaur bones not only enhance the preservation (fossilisation) of fungal remains but can also be used as indicators of the geochemistry of the dinosaur burial sites.

  15. Fungal Ferromanganese Mineralisation in Cretaceous Dinosaur Bones from the Gobi Desert, Mongolia.

    Directory of Open Access Journals (Sweden)

    Krzysztof Owocki

    Full Text Available Well-preserved mycelia of fungal- or saprolegnia-like biota mineralised by ferromanganese oxides were found for the first time in long bones of Late Cretaceous dinosaurs from the Gobi Desert (Nemegt Valley, Mongolia. The mycelia formed a biofilm on the wall of the bone marrow cavity and penetrated the osteon channels of the nearby bone tissue. Optical microscopy, Raman, SEM/EDS, SEM/BSE, electron microprobe and cathodoluminescence analyses revealed that the mineralisation of the mycelia proceeded in two stages. The first stage was early post-mortem mineralisation of the hyphae by Fe/Mn-oxide coatings and microconcretions. Probably this proceeded in a mildly acidic to circumneutral environment, predominantly due to heterotrophic bacteria degrading the mycelial necromass and liberating Fe and Mn sorbed by the mycelia during its lifetime. The second stage of mineralisation, which proceeded much later following the final burial of the bones in an alkaline environment, resulted from the massive precipitation of calcite and occasionally barite on the iron/manganese-oxide-coated mycelia. The mineral phases produced by fungal biofilms colonising the interiors of decaying dinosaur bones not only enhance the preservation (fossilisation of fungal remains but can also be used as indicators of the geochemistry of the dinosaur burial sites.

  16. Specific characteristics of essential oils of four Artemisia species from the Mongolian Trans-Altai Gobi

    Directory of Open Access Journals (Sweden)

    N. Javzmaa

    2016-03-01

    Full Text Available The essential oil compositions of four Artemisia species in Mongolian Trans-Altai Gobi were studied by gas chromatography (GC and gas chromatography-mass spectrometry (GC-MS. The oil from A.macrocephala Jacq and A.dracunculus Ledeb. were characterized by the presence of monoterpene hydrocarbons and oxygenated monoterpeneoids predominately. E-nerolidol (26.95%, methyleugenol (23.29% and sabinene (13.21% were found as main components in the essential oils of A.dracunculus. A.macrocephalla was characterized by the presence of chamazulene (13.8%, cineol (11.7%, myrcene (9.0%, germacrene-D (7.1%. A.anethifolia Web was characterized by the presence of fragrant compounds as camphor (26.05%, α-thujone (10.1%, borneol (5.1%. Davanone and davanone derivatives were also detected in the sample in amount of 7.7% in total. A.scoparia Waldst differed by domination of monoterpene hydrocarbons (78.9% with (Z- β-ocimene (29.24%, α-pinene (15.19%, limonene (10.27% and myrcene (9.61%.Mongolian Journal of Chemistry 16 (42, 2015, 34-38

  17. Microhabitat associations of a semi-terrestrial fish, Kryptolebias marmoratus (Poey 1880) in a mosquito-ditched mangrove forest, west-central Florida

    Science.gov (United States)

    Richards, Travis M.; Krebs, Justin M.; McIvor, Carole C.

    2011-01-01

    Mangrove rivulus (Kryptolebias marmoratus) is one of the few species of fish that is semi-terrestrial and able to use exposed intertidal and potentially supratidal habitats for prolonged periods of time. Based on previous work demonstrating frequent use of subterranean crab burrows as well as damp leaf litter and logs, we examined the microhabitat associations of rivulus in a mosquito-ditched mangrove forest on the Gulf coast of Florida near the northern limit of its distribution. We captured 161 rivulus on 20 dates between late April and mid-December 2007 using trench traps. Fish ranged in size from 7 to 35 mm SL. Peak abundance in mid-summer coincided with recruitment of a new year-class. The three study sites occurred within 0.5 km of one another, and experienced similar water temperatures and salinities. Nevertheless, they differed in their degree of tidal inundation, standing stock of leaf litter, and density of entrances to fiddler crab burrows. We consistently observed the highest mean catches of rivulus away from permanent subtidal waters of mosquito ditches, at intermediate relative elevations, and where leaf litter was locally abundant. Density of entrances to crab burrows was apparently unrelated to rivulus distribution or abundance in these forests.

  18. Algunos rasgos de la historia vital de los adultos de tritón jaspeado (Triturus marmoratus en charcas de colonización reciente

    Directory of Open Access Journals (Sweden)

    GOSÁ, A., SARASOLA, V.

    2010-01-01

    Full Text Available En el Área Natural Recreativa del Bosque de Orgi (Navarra, un robledal de roble pedunculado (Quercus robur encharcado en fondo de valle (550 m.s.n.m., se viene realizando un programa de recuperación de la población local de rana ágil (Rana dalmatina desde 1999, mediante creación de charcas, que habían desaparecido del enclave. Al año siguiente el tritón jaspeado (Triturus marmoratus, desconocido en esa fecha, empezó a reproducirse en las charcas, aumentando su población hasta 2004. Desde entonces ésta se ha mantenido con ligeras fluctuaciones. El sex-ratio global de la población es favorable a los machos (1.58:1, algunos de los cuáles alcanzan la madurez sexual al segundo año de vida. La talla (hocico-cloaca de las hembras es significativamente mayor. La estación reproductora se extiende entre finales de otoño y primavera, y la migración a las charcas está correlacionada con la temperatura ambiental. La emergencia de los metamorfoseados se produce en julio.

  19. A New Species of the Bay Goby Genus Eucyclogobius, Endemic to Southern California: Evolution, Conservation, and Decline.

    Science.gov (United States)

    Swift, Camm C; Spies, Brenton; Ellingson, Ryan A; Jacobs, David K

    2016-01-01

    A geographically isolated set of southern localities of the formerly monotypic goby genus Eucyclogobius is known to be reciprocally monophyletic and substantially divergent in mitochondrial sequence and nuclear microsatellite-based phylogenies relative to populations to the north along the California coast. To clarify taxonomic and conservation status, we conducted a suite of analyses on a comprehensive set of morphological counts and measures from across the range of Eucyclogobius and describe the southern populations as a new species, the Southern Tidewater Goby, Eucyclogobius kristinae, now separate from the Northern Tidewater Goby Eucyclogobius newberryi (Girard 1856). In addition to molecular distinction, adults of E. kristinae are diagnosed by: 1) loss of the anterior supratemporal lateral-line canals resulting in higher neuromast counts, 2) lower pectoral and branched caudal ray counts, and 3) sets of measurements identified via discriminant analysis. These differences suggest ecological distinction of the two species. Previous studies estimated lineage separation at 2-4 million years ago, and mitochondrial sequence divergence exceeds that of other recognized fish species. Fish from Santa Monica Artesian Springs (Los Angeles County) northward belong to E. newberryi; those from Aliso Creek (Orange County) southward constitute E. kristinae. The lagoonal habitat of Eucyclogobius has been diminished or degraded, leading to special conservation status at state and federal levels beginning in 1980. Habitat of the newly described species has been impacted by a range of anthropogenic activities, including the conversion of closing lagoons to open tidal systems in the name of restoration. In the last 30 years, E. kristinae has only been observed in nine intermittently occupied lagoonal systems in northern San Diego County; it currently persists in only three sites. Thus, the new species is in imminent danger of extinction and will require ongoing active management.

  20. Standardization of plasma vitellogenin level for surveying environmental estrogen pollution using the Japanese common goby Acanthogobius flavimanus.

    Science.gov (United States)

    Song, Jing; Nagae, Masaki; Soyano, Kiyoshi

    2018-03-09

    Field surveys of the impact of environmental estrogen (EE) pollution in aquatic wildlife have been conducted using vitellogenin (VTG) as a biomarker to evaluate the influence of EE. However, a standard baseline of VTG level that can be used to evaluate EE pollution has not been fully determined. To the best of our knowledge, the present study is the first to determine the standard baseline VTG level for evaluating the biological effects of EE pollution using the Japanese common goby (Acanthogobius flavimanus) as the target model fish. Plasma VTG and estradiol-17β (E 2 ) levels associated with the reproductive cycle of wild goby inhabiting an unpolluted environment were measured. Mean plasma VTG and E 2 levels exhibited similar changes, increasing in the yolk vesicle stage and peaking in the tertiary yolk stage in females. However, plasma VTG and E 2 levels showed no significant changes in males, remaining at low levels throughout the reproductive cycle. The highest VTG levels in females and males were 1.6 mg ml -1 and 124.87 ng ml -1 , respectively. These results indicate that the baseline level (normal level) in males was approximately 130 ng ml -1 at most. We concluded that the threshold between normal and abnormal levels with a 10% risk rate was 150 ng ml -1 in the wild male goby. Plasma VTG levels in males captured from Nagasaki Harbor were higher than the threshold in each reproductive developmental stage, indicating the possibility of EE pollution at this site. The biological standard baseline for VTG established in this study is useful for assessing EE pollution in natural waters. Copyright © 2018 John Wiley & Sons, Ltd.

  1. Revising the distribution of a threatened goby, Apocryptodon punctatus (Perciformes, Oxudercidae, in Japan with the discovery of an isolated population

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    Atsunobu Murase

    2017-01-01

    Full Text Available Five specimens of a threatened goby, Apocryptodon punctatus (21.2–40.1 mm in standard length, were collected at a mudflat site of Kushima City, Miyazaki Prefecture, Kyushu, southern Japan over two seasons, autumn (September 2015 and spring (April 2016. A review of distributional records of A. punctatus revealed that this population represents the southernmost record of the species in Japanese waters, and is isolated ca. 200 km south-southwest from the nearest point of the main range of the species along the Pacific coast of Japan. Publicising this population will help conserve it and its vulnerable habitat.

  2. Desert pastoralists' negative and positive effects on rare wildlife in the Gobi.

    Science.gov (United States)

    Ekernas, L Stefan; Sarmento, Wesley M; Davie, Hannah S; Reading, Richard P; Murdoch, James; Wingard, Ganchimeg J; Amgalanbaatar, Sukh; Berger, Joel

    2017-04-01

    In arid regions of the developing world, pastoralists and livestock commonly inhabit protected areas, resulting in human-wildlife conflict. Conflict is inextricably linked to the ecological processes shaping relationships between pastoralists and native herbivores and carnivores. To elucidate relationships underpinning human-wildlife conflict, we synthesized 15 years of ecological and ethnographic data from Ikh Nart Nature Reserve in Mongolia's Gobi steppe. The density of argali (Ovis ammon), the world's largest wild sheep, at Ikh Nart was among the highest in Mongolia, yet livestock were >90% of ungulate biomass and dogs >90% of large-carnivore biomass. For argali, pastoral activities decreased food availability, increased mortality from dog predation, and potentially increased disease risk. Isotope analyses indicated that livestock accounted for >50% of the diet of the majority of gray wolves (Canis lupus) and up to 90% of diet in 25% of sampled wolves (n = 8). Livestock composed at least 96% of ungulate prey in the single wolf pack for which we collected species-specific prey data. Interviews with pastoralists indicated that wolves annually killed 1-4% of Ikh Nart's livestock, and pastoralists killed wolves in retribution. Pastoralists reduced wolf survival by killing them, but their livestock were an abundant food source for wolves. Consequently, wolf density appeared to be largely decoupled from argali density, and pastoralists had indirect effects on argali that could be negative if pastoralists increased wolf density (apparent competition) or positive if pastoralists decreased wolf predation (apparent facilitation). Ikh Nart's argali population was stable despite these threats, but livestock are increasingly dominant numerically and functionally relative to argali. To support both native wildlife and pastoral livelihoods, we suggest training dogs to not kill argali, community insurance against livestock losses to wolves, reintroducing key native prey species

  3. Prey Preference of Snow Leopard (Panthera uncia) in South Gobi, Mongolia

    Science.gov (United States)

    Shehzad, Wasim; McCarthy, Thomas Michael; Pompanon, Francois; Purevjav, Lkhagvajav; Coissac, Eric; Riaz, Tiayyba; Taberlet, Pierre

    2012-01-01

    Accurate information about the diet of large carnivores that are elusive and inhabit inaccessible terrain, is required to properly design conservation strategies. Predation on livestock and retaliatory killing of predators have become serious issues throughout the range of the snow leopard. Several feeding ecology studies of snow leopards have been conducted using classical approaches. These techniques have inherent limitations in their ability to properly identify both snow leopard feces and prey taxa. To examine the frequency of livestock prey and nearly-threatened argali in the diet of the snow leopard, we employed the recently developed DNA-based diet approach to study a snow leopard population located in the Tost Mountains, South Gobi, Mongolia. After DNA was extracted from the feces, a region of ∼100 bp long from mitochondrial 12S rRNA gene was amplified, making use of universal primers for vertebrates and a blocking oligonucleotide specific to snow leopard DNA. The amplicons were then sequenced using a next-generation sequencing platform. We observed a total of five different prey items from 81 fecal samples. Siberian ibex predominated the diet (in 70.4% of the feces), followed by domestic goat (17.3%) and argali sheep (8.6%). The major part of the diet was comprised of large ungulates (in 98.8% of the feces) including wild ungulates (79%) and domestic livestock (19.7%). The findings of the present study will help to understand the feeding ecology of the snow leopard, as well as to address the conservation and management issues pertaining to this wild cat. PMID:22393381

  4. The Genome of the Self-Fertilizing Mangrove Rivulus Fish, Kryptolebias marmoratus: A Model for Studying Phenotypic Plasticity and Adaptations to Extreme Environments.

    Science.gov (United States)

    Kelley, Joanna L; Yee, Muh-Ching; Brown, Anthony P; Richardson, Rhea R; Tatarenkov, Andrey; Lee, Clarence C; Harkins, Timothy T; Bustamante, Carlos D; Earley, Ryan L

    2016-08-16

    The mangrove rivulus (Kryptolebias marmoratus) is one of two preferentially self-fertilizing hermaphroditic vertebrates. This mode of reproduction makes mangrove rivulus an important model for evolutionary and biomedical studies because long periods of self-fertilization result in naturally homozygous genotypes that can produce isogenic lineages without significant limitations associated with inbreeding depression. Over 400 isogenic lineages currently held in laboratories across the globe show considerable among-lineage variation in physiology, behavior, and life history traits that is maintained under common garden conditions. Temperature mediates the development of primary males and also sex change between hermaphrodites and secondary males, which makes the system ideal for the study of sex determination and sexual plasticity. Mangrove rivulus also exhibit remarkable adaptations to living in extreme environments, and the system has great promise to shed light on the evolution of terrestrial locomotion, aerial respiration, and broad tolerances to hypoxia, salinity, temperature, and environmental pollutants. Genome assembly of the mangrove rivulus allows the study of genes and gene families associated with the traits described above. Here we present a de novo assembled reference genome for the mangrove rivulus, with an approximately 900 Mb genome, including 27,328 annotated, predicted, protein-coding genes. Moreover, we are able to place more than 50% of the assembled genome onto a recently published linkage map. The genome provides an important addition to the linkage map and transcriptomic tools recently developed for this species that together provide critical resources for epigenetic, transcriptomic, and proteomic analyses. Moreover, the genome will serve as the foundation for addressing key questions in behavior, physiology, toxicology, and evolutionary biology. © The Author 2016. Published by Oxford University Press on behalf of the Society for Molecular

  5. Adverse effects of BDE-47 on in vivo developmental parameters, thyroid hormones, and expression of hypothalamus-pituitary-thyroid (HPT) axis genes in larvae of the self-fertilizing fish Kryptolebias marmoratus.

    Science.gov (United States)

    Kang, Hye-Min; Lee, Young Hwan; Kim, Bo-Mi; Kim, Il-Chan; Jeong, Chang-Bum; Lee, Jae-Seong

    2017-06-01

    2,2',4,4'-tetrabromodiphenylether (BDE-47) is known to have the potential to disrupt the thyroid endocrine system in fishes due to its structural similarity to the thyroid hormones triiodothyronine (T3) and thyroxine (T4). However, the effects of BDE-47 on thyroid function in fishes remain unclear. In this study, abnormal development (e.g. deformity, hemorrhaging) and an imbalance in thyroid hormone (TH) homeostasis was shown in the early developmental stages of the mangrove killifish Kryptolebias marmoratus in response to BDE-47 exposure. To examine the thyroid endocrinal effect of BDE-47 exposure in mangrove killifish K. marmoratus larvae, transcript levels of genes involved in TH homeostasis and hypothalamus-pituitary-thyroid (HPT) axis-related genes were measured. The expression of thyroid hormone metabolism-related genes (e.g. deiodinases, UGT1ab) and HPT axis-related genes was up-regulated and there were significant changes in TH levels (P thyroid endocrine system of fishes. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Does invader like invader? Feeding preferences of an alien Ponto-Caspian goby towards indigenous and non-indigenous amphipod prey

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    Dagmara Błońska

    2015-11-01

    Full Text Available When non-native species appear in a new ecosystem, it may sufficiently affect native communities i.a. through interactions with native as well as other alien species. The „invasional meltdown“ hypothesis states that the presence of non-indigenous species facilitates the introduction and establishment of the other non-native species. A series of laboratory experiments was conducted to test the occurence of the invasional meltdown phenomenon within the invasive Ponto-Caspian community. Preferences of an alien Ponto-Caspian racer goby, Babka gymnotrachelus, towards amphipod preys of the same origin (Dikerogammarus villosus, Pontogammarus robustoides or a prey species native to the resident community (Gammarus fossarum were verified. Additionally, we tested the profitability of native and invasive prey for fish in a growth experiment. Accordingly with the invasional meltdown hypothesis, we hypothesized that the racer goby would prefer Ponto-Caspian amphipods and that prey would be more beneficial than native ones, which should result in higher growth rate. We found that the racer goby always selected the native G. fossarum, regardless of the prey mobility, presence of shelters and waterborne chemical cues. Thus, the fish choice was based on the assessment of prey quality during a direct contact with amphipods. The growth experiment indicated that the racer goby grew better on the native gammarid compared to the Ponto-Caspian species. The outcome of our study does not support the invasional meltdown hypothesis within the goby – gammarids predator prey system, as the non-native prey species were neither prefered nor more profitable food for the alien predator. Thus, we found no evidence for facilitation of establishement between the studied taxa.

  7. Paleomagnetic and palynologic analyses of Albian to Santonian strata at Bayn Shireh, Burkhant, and Khuren Dukh, eastern Gobi Desert, Mongolia

    Science.gov (United States)

    Hicks, J.F.; Brinkman, D.L.; Nichols, D.J.; Watabe, M.

    1999-01-01

    Cretaceous terrestrial sediments deposited in a series of intracratonic basins across the Gobi Desert region of southern Mongolia and northern China contain a unique and diverse vertebrate fauna. In 1996 an expedition jointly sponsored by the Mongolian Paleontological Center and the Hayashibara Museum of Natural Sciences revisited a number of famous vertebrate fossil localities in the eastern Gobi region of Mongolia and, as part of a broad geological and paleontological study, collected a series of paleomagnetic samples from measured sections at Bayn Shireh, Burkhant and Khuren Dukh, as well as from an unmeasured locality adjacent to Khuren Dukh. Expedition members also collected palynologic samples from Khuren Dukh and the adjacent locality. Paleomagnetic analysis shows that all the sites from which samples were collected display detrital remnant magnetization that is consistently normal in polarity. The measured Cretaceous magnetic directions are oriented to the east or northeast of the present day expected direction (declination 356.2??, inclination 65.2??), and they are wholly concordant with that expected for a mid-latitude Northern Hemisphere sampling locality, and with the directions for this period reported by other workers. These results, when considered in tandem with the known biostratigraphy, strongly suggest that the sedimentary deposits at all four localities in the eastern Gobi correlate to the normal polarity chron 34 (the Cretaceous Long Normal), which ranges in age from approximately 121 to 83.5 million years. Previous vertebrate, invertebrate and palynological data from Khuren Dukh suggest that the lower and middle parts of the stratigraphic interval exposed there (which have been assigned to the Shinekhudag Formation) are 'Khukhtekian' in age and correspond to the Aptian-Albian interval that can be broadly correlated to the older, Early Cretaceous part of the Cretaceous Long Normal, C34n. New palynologic data presented here indicate that these

  8. Cathodoluminescence characterization of quartz grains from the Upper Cretaceous of dinosaur fossil localities in the Gobi desert, Mongolia

    Science.gov (United States)

    Saneyoshi, M.; Nishido, H.; Masuda, R.; Tsogtbaatar, K.; Chinzorig, T.

    2013-12-01

    The Upper Cretaceous eolian sediments in Mongolia's Gobi desert are one of the most important occurrences of the dinosaurs in the world. Large numbers of confiscated dinosaur fossils illegally worked out by poachers has been stored in the Mongolian Paleontological Center at Ulaanbaatar. In most cases, their localities are unknown. The purpose of this study is to identify their localities by cathodoluminescence (CL) features of quartz grains attached to the dinosaur specimens by comparing to the quartz samples collected from the sediments of circumjacent resources in this area. This study focuses on the confiscated specimen which makes up the nest with the babies' Protoceratops. Most of all Protoceratops in every growth process, have been discovered from the Djadokhta Formation in the Gobi desert. This formation crops out at Tugrikin Shireh and Bayn Dzak in the central part of the Gobi desert, and is derived from medium- to fine-grained sand mainly composed of quartz grains, of which sedimentary environments should be obvious to be eolian. The formation age of the sand beds at Tugrikin Shireh and Bayn Dzak has been estimated to be Middle Campanian. CL spectra of quartz have been demonstrated to show different features between the quartz from hydrothermal, plutonic, volcanic and metamorphic origins, suggesting the spectra reflect the condition of the quartz formation and the local environment. Therefore, we have applied the CL characterization of quartz grains to the evaluation of the provenance of the desert sediments. The quartz grains after sieving (#60-80 mesh size) were embedded in the brass holders with non-luminescent epoxy resin, and their surfaces were polished with 1 μm diamond abrasive. Color CL images obtained by the Luminoscope exhibit blue, violet and red emissions in the grains, suggesting various types of emission centers in the quartz. SEM-CL analysis was conducted using an SEM (JSM-5410) combined with a grating monochromator (Mono CL2) to measure

  9. First record of Pontian Monkey Goby, Neogobius fluviatilis (Pallas, 1814 in the Evros River (Greece; Is it an alien species?

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    S. ZOGARIS

    2011-11-01

    Full Text Available The Pontian Monkey Goby,Neogobius fluviatilis (Pallas, 1814, was recorded for the first time in Greece in August 2011. Eight specimens were collected in the Greek-Turkish section of the Evros River, 65 kilometers upstream of its river-mouth. Although the species has been recently discovered in the Tundza, a tributary of the Evros in Bulgaria, it has never before been found in the Evros’ main stem.  Although the lower Evros has been poorly researched by ichthyologists, it is unlikely that a conspicuous medium-sized fish would go unnoticed in this river; and, it is therefore suggested to be a probable alien. However, since the Evros basin has had geological connections to the Marmara Sea and Black Sea in the past and it is immediately adjacent to native populations of N. fluviatilis, the species status is categorized as questionable until genetic and morphological studies are completed.

  10. A new mesophotic goby, Palatogobius incendius (Teleostei: Gobiidae, and the first record of invasive lionfish preying on undescribed biodiversity.

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    Luke Tornabene

    Full Text Available A new species of deep-reef fish in the goby genus Palatogobius is described from recent submersible collections off Curaçao and Dominica. Video footage of schools of this species reveal predation by the invasive Indo-Pacific lionfish (Pterois spp., the first record of undescribed fauna potentially being eaten by lionfish outside of its native range. We present molecular phylogenetic data for all valid species of Palatogobius and related genera, as well as a taxonomic key to the species of Palatogobius and a generic key to Palatogobius and related genera in the western Atlantic. Lastly, we discuss ecological and behavioral aspects of some deep-reef fishes in light of potential threats from invasive lionfish.

  11. A study of variation characteristics of Gobi broadband emissivity based on field observational experiments in northwestern China

    Science.gov (United States)

    Zheng, Zhi-yuan; Wei, Zhi-gang; Wen, Zhi-ping; Dong, Wen-jie; Li, Zhen-chao; Wen, Xiao-hang; Zhu, Xian; Chen, Chen; Hu, Shan-shan

    2018-02-01

    Land surface emissivity is a significant variable in energy budgets, land cover assessments, and environment and climate studies. However, the assumption of an emissivity constant is being used in Gobi broadband emissivity (GbBE) parameterization scheme in numerical models because of limited knowledge surrounding the spatiotemporal variation characteristics of GbBE. To address this issue, we analyzed the variation characteristics of GbBE and possible impact factor-surface soil moisture based on long-term continuous and high temporal resolution field observational experiments over a typical Gobi underlying surface in arid and semiarid areas in northwestern China. The results indicate that GbBE has obvious daily and diurnal variation features, especially diurnal cycle characteristics. The multi-year average of the daily average of GbBE is in the range of 0.932 to 0.970 with an average of 0.951 ± 0.008, and the average diurnal GbBE is in the range of 0.880 to 0.940 with an average of 0.906 ± 0.018. GbBE varies with surface soil moisture content. We observed a slight decrease in GbBE with an increase in soil moisture, although this change was not very obvious because of the low soil moisture in this area. Nevertheless, we think that soil moisture must be one of the most significant impact factors on GbBE in arid and semiarid areas. Soil moisture must be taken into account into the parameterization schemes of bare soil broadband emissivity in land surface models. Additional field experiments and studies should be carried out in order to clarify this issue.

  12. La dieta y fauna de endoparásitos del pejesapo Gobiesox marmoratus Jenyns, 1842 (Pisces: Gobiesocidae en el litoral central de Chile están conectadas pero no correlacionadas Feeding habits and endoparasite fauna of the clingfish Gobiesox marmoratus Jenyns, 1842 (Pisces: Gobiesocidae on the central coast of Chile are intertwined, but not correlated

    Directory of Open Access Journals (Sweden)

    M. Cecilia Pardo-Gandarillas

    2004-12-01

    Full Text Available Se documenta una alta similitud en la composición de la fauna parasitaria y de la dieta de 108 ejemplares del pejesapo Gobiesox marmoratus Jenyns, 1842 recolectados de la costa de la zona centro-sur de Chile, desde tres localidades separadas por al menos 400 km de su(s vecina(s. La longitud total de los pejesapos fue similar entre localidades y su parasitofauna estuvo compuesta por 16 taxa de metazoos (incluyendo cinco Myxozoa. En el 38,8 % de los 108 pejesapos se encontraron parásitos, en tanto que en el 32,4 % de los mismos ejemplares había contenido estomacal, en los que se determinaron 37 ítems presa. La aún más baja ocurrencia conjunta de parásitos y presas imposibilitó el uso de parejas de datos parasitarios y dietarios, para evaluar, por ejemplo, si había correlación entre la amplitud dietaria y la riqueza parasitaria. Aunque la composición de la fauna de endoparásitos necesariamente depende de la composición de la dieta de los pejesapos, encontramos muy pocos parásitos en uno de los sitios de estudio. Es decir, las propiedades numéricas de este sistema hospedador-parásito limitaron la posibilidad de hallar asociaciones entre ambos tipos de variables. Tanto la composición de la dieta como de las infracomunidades de parásitos variaban con la ontogenia del huésped. La dieta de los pejesapos juveniles y adultos consistía principalmente de anfípodos, crustáceos decápodos y moluscos en las tres localidades. La similitud de los descriptores numéricos de la dieta y de las infracomunidades (abundancia total, diversidad y riqueza entre las localidades, en parte puede deberse al escaso tamaño corporal máximo alcanzado por G. marmoratus, a la escasa longitud total del tracto digestivo, a las diferencias en las tasas de ingreso y tiempo de residencia de parásitos y presas, al nivel de resolución taxonómica alcanzado en presas y/o parásitos, y al efecto de decidir excluir o no de los análisis a las especies rarasA high

  13. Early engagement of stakeholders with individual-based modelling can inform research for improving invasive species management: the round goby as a case study

    DEFF Research Database (Denmark)

    Samson, Emma; Hirsch, Philipp E.; Palmer, Stephen C.

    2017-01-01

    that subsequent models can provide robust insight into potential management interventions. The round goby, Neogobius melanostomus, is currently spreading through the Baltic Sea, with major negative effects being reported in the wake of its invasion. Together with stakeholders, we parameterize an IBM...... to investigate the goby's potential spread pattern throughout the Gulf of Gdansk and the Baltic Sea. Model parameters were assigned by integrating information obtained through stakeholder interaction, from scientific literature, or estimated using an inverse modeling approach when not available. IBMs can provide...... valuable direction to research on invasive species even when there is limited data and/or time available to parameterize/fit them to the degree to which we might aspire in an ideal world. Co-development of models with stakeholders can be used to recognize important invasion patterns, in addition...

  14. The danger of having all your eggs in one basket--winter crash of the re-introduced Przewalski's horses in the Mongolian Gobi.

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    Petra Kaczensky

    Full Text Available Large mammals re-introduced into harsh and unpredictable environments are vulnerable to stochastic effects, particularly in times of global climate change. The Mongolian Gobi is home to several rare large ungulates such as re-introduced Przewalski's horses (Equus ferus przewalskii and Asiatic wild asses (Equus hemionus, but also to a millennium-old semi-nomadic livestock herding culture.The Gobi is prone to large inter-annual environmental fluctuations, but the winter 2009/2010 was particularly severe. Millions of livestock died and the Przewalski's horse population in the Gobi crashed. We used spatially explicit livestock loss statistics, ranger survey data and GPS telemetry to provide insight into the effect of a catastrophic climate event on the two sympatric wild equid species and the livestock population in light of their different space use strategies.Herders in and around the Great Gobi B Strictly Protected Area lost on average 67% of their livestock. Snow depth varied locally, resulting in livestock losses following an east-west gradient. Herders had few possibilities for evasion, as competition for available winter camps was high. Przewalski's horses used three different winter ranges, two in the east and one in the west. Losses averaged 60%, but differed hugely between east and west. Space use of Przewalski's horses was extremely conservative, as groups did not attempt to venture beyond their known home ranges. Asiatic wild asses seemed to have suffered few losses by shifting their range westwards.The catastrophic winter 2009/2010 provided a textbook example for how vulnerable small and spatially confined populations are in an environment prone to environmental fluctuations and catastrophes. This highlights the need for disaster planning by local herders, multiple re-introduction sites with spatially dispersed populations for re-introduced Przewalski's horses, and a landscape-level approach beyond protected area boundaries to allow for

  15. Anticipation of Artemia sp. supply in the larviculture of the barber goby Elacatinus figaro (Gobiidae: Teleostei influenced growth, metamorphosis and alkaline protease activity

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    Maria Fernanda da Silva-Souza

    2015-09-01

    Full Text Available The barber goby Elacatinus figaro is considered endangered due to overexploitation by the ornamental industry. Farming marine ornamental fishes, especially the threatened ones, can be one of the measures to minimize the pressure on the natural stocks. Among the priority issues for their production is the determination of the most appropriate feeding management. The feeding protocol commonly used in the larviculture of barber goby, when the start of Artemia sp. offer occurred at the 18th DAH (days after hatching (treatment T18, was modified, by anticipating brine shrimp supply in 6 days (treatment T12. Alkaline proteases activity, growth and metamorphosis of larvae were evaluated in both protocols. Juveniles at T12 showed higher weight (0.04 ± 0.001 g and lower activity of total alkaline proteases (1.3 ± 0.2 mU mg-1 protein compared to T18 (0.02 ± 0.001 g; 2.8 ± 0.4 mU mg-1 protein, respectively. With anticipation of brine shrimp, the commencing and end of larval transformation was observed earlier (at 24 and 34 DAH, respectively in comparison to those with the supply of Artemia sp. at 18 DAH (27 and 41 DAH, respectively. Thus, the Artemia sp. anticipation was beneficial during the larviculture of the barber goby, considering that larvae reached metamorphosis earlier.

  16. Double origin of the racer goby (Babka gymnotrachelus in Poland revealed with mitochondrial marker. Possible implications for the species alien/native status

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    Michal Grabowski

    2015-09-01

    Full Text Available In mid-1990s racer goby, Babka gymnotrachelus, penetrated to the Vistula and Western Bug rivers in Poland through the canal connecting the Baltic and the Black Sea basins, namely the Vistula and Dnieper drainages. In early 2000s, the species was reported from Polish section of the Strwiąż River that is an affluent of the Dniester River that drains to the Black Sea basin. According to the Polish legislation, the racer goby has been enlisted in as an alien invasive species that may pose threat to local biota. Our analysis of the mtDNA cytochrome b diversity revealed that the Vistula/Western Bug and Strwiąż populations are different genetic units. First one originated from the Dnieper River, while the second derives from the Dniester River. According to the results of mismatch analysis, both are in the stage of demographic and spatial expansion. The haplotype frequencies in population from the Vistula/Western Bug differ significantly from those in the source population in Dnieper, suggesting founder effect, possibly due to human-mediated introduction of low number of individuals. On the other side, the population in Strwiąż does not differ in structure from the one in Dniester, providing a hint towards spontaneous range expansion. Interpretation of our results in light of historical data lead to the conclusion that presence of racer goby in Strwiąż was probably overlooked in previous, spatially limited, studies. Thus, in Strwiąż the species should not be treated as alien, contrary to its status in the Vistula drainage. This double origin of racer goby populations in Poland creates a peculiar situation for national legislation procedures as one population is alien and invasive, while the other one is not. In light of our findings, the population from Strwiąż should be recognised as a special case. Steps should be undertaken to raise public awareness to prevent translocation of the gobies between the rivers to prevent deterioration of the

  17. Ecological differences in three autochthonous equid species in Mongolian Gobi inferred from stable isotopes in tail hair

    Science.gov (United States)

    Burnik Šturm, Martina; Voigt, Christian C.; Oyunsaikhan, Ganbaatar; Kaczensky, Petra

    2014-05-01

    In the Dzungarian Gobi of Mongolia three equid species, Asiatic wild ass (Equus hemionus), domestic horse (Equus caballus), and re-introduced Przewalski's horse (Equus ferus przewalskii) share the same habitat and thus provide a unique opportunity for comparative ecological studies. In our project we use the stable isotope analysis of tail hair as a tool to study feeding ecology, water use and movement pattern of the three extant sympatric equid species to reveal species specific differences and thus strengthen our understanding of the ecological adaptations of the three species to the harsh environment of the Gobi desert. Since tail hair grow continuously and is isotopically inert after formation, when sampled and analysed longitudinally, provides temporary explicit information on dietary regime and movement pattern. We use the carbon isotopes in the tail hair to determine the quantitative dependence of each animal on isotopically distinct C3 (grasses) and C4 (multitude of annuals and perennials) diet. Nitrogen isotopes reflect the isotopic composition of the diet and hydrogen isotopes reflect the isotopic composition of the water that animals utilize, while both elements have been reported to also give information on the physical status of the animal. Combined isotope data will be used to describe the movement patterns and habitat use of the three equid species. We will present the methodology and first preliminary results of carbon and nitrogen isotope analysis of potential forage plants of the study area and of the tail hair analysis. Among the analysed plants, collected in the pilot sampling campaign in 2012 (n = 192), we identified 14 C3 and two C4species and found no general trend that could explain the effect of altitude on carbon isotopic composition in C3 plants and no correlation between carbon isotopic composition and longitude or latitude. We performed additional, more detailed plant sampling in 2013. The first results obtained from the tail hair

  18. Habitat selection of two gobies (Microgobius gulosus, Gobiosoma robustum): influence of structural complexity, competitive interactions and presence of a predator

    Science.gov (United States)

    Schofield, P.J.

    2003-01-01

    Herein I compare the relative importance of preference for structurally complex habitat against avoidance of competitors and predators in two benthic fishes common in the Gulf of Mexico. The code goby Gobiosoma robustum Ginsburg and clown goby Microgobius gulosus (Girard) are common, ecologically similar fishes found throughout the Gulf of Mexico and in the southeastern Atlantic Ocean. In Florida Bay, these fishes exhibit habitat partitioning: G. robustum is most abundant in seagrass-dominated areas while M. gulosus is most abundant in sparsely vegetated habitats. In a small-scale field survey, I documented the microhabitat use of these species where their distributions overlap. In a series of laboratory experiments, I presented each species with structured (artificial seagrass) versus nonstructured (bare sand) habitats and measured their frequency of choosing either habitat type. I then examined the use of structured versus nonstructured habitats when the two species were placed together in a mixed group. Finally, I placed a predator (Opsanus beta) in the experimental aquaria to determine how its presence influenced habitat selection. In the field, G. robustum was more abundant in seagrass and M. gulosus was more abundant in bare mud. In the laboratory, both species selected grass over sand in allopatry. However, in sympatry, M. gulosus occupied sand more often when paired with G. robustum than when alone. G. robustum appears to directly influence the habitat choice of M. gulosus: It seems that M. gulosus is pushed out of the structured habitat that is the preferred habitat of G. robustum. Thus, competition appears to modify the habitat selection of these species when they occur in sympatry. Additionally, the presence of the toadfish was a sufficient stimulus to provoke both M. gulosus and G. robustum to increase their selection for sand (compared to single-species treatments). Distribution patterns of M. gulosus and G. robustum

  19. McGET: A rapid image-based method to determine the morphological characteristics of gravels on the Gobi desert surface

    Science.gov (United States)

    Mu, Yue; Wang, Feng; Zheng, Bangyou; Guo, Wei; Feng, Yiming

    2018-03-01

    The relationship between morphological characteristics (e.g. gravel size, coverage, angularity and orientation) and local geomorphic features (e.g. slope gradient and aspect) of desert has been used to explore the evolution process of Gobi desert. Conventional quantification methods are time-consuming, inefficient and even prove impossible to determine the characteristics of large numbers of gravels. We propose a rapid image-based method to obtain the morphological characteristics of gravels on the Gobi desert surface, which is called the "morphological characteristics gained effectively technique" (McGET). The image of the Gobi desert surface was classified into gravel clusters and background by a machine-learning "classification and regression tree" (CART) algorithm. Then gravel clusters were segmented into individual gravel clasts by separating objects in images using a "watershed segmentation" algorithm. Thirdly, gravel coverage, diameter, aspect ratio and orientation were calculated based on the basic principles of 2D computer graphics. We validated this method with two independent datasets in which the gravel morphological characteristics were obtained from 2728 gravels measured in the field and 7422 gravels measured by manual digitization. Finally, we applied McGET to derive the spatial variation of gravel morphology on the Gobi desert along an alluvial-proluvial fan located in Hami, Xinjiang, China. The validated results show that the mean gravel diameter measured in the field agreed well with that calculated by McGET for large gravels (R2 = 0.89, P < 0.001). Compared to manual digitization, the McGET accuracies for gravel coverage, gravel diameter and aspect ratio were 97%, 83% and 96%, respectively. The orientation distributions calculated were consistent across two different methods. More importantly, McGET significantly shortens the time cost in obtaining gravel morphological characteristics in the field and laboratory. The spatial variation results

  20. Getting what is served? Feeding ecology influencing parasite-host interactions in invasive round goby Neogobius melanostomus.

    Science.gov (United States)

    Emde, Sebastian; Kochmann, Judith; Kuhn, Thomas; Plath, Martin; Klimpel, Sven

    2014-01-01

    Freshwater ecosystems are increasingly impacted by alien invasive species which have the potential to alter various ecological interactions like predator-prey and host-parasite relationships. Here, we simultaneously examined predator-prey interactions and parasitization patterns of the highly invasive round goby (Neogobius melanostomus) in the rivers Rhine and Main in Germany. A total of 350 N. melanostomus were sampled between June and October 2011. Gut content analysis revealed a broad prey spectrum, partly reflecting temporal and local differences in prey availability. For the major food type (amphipods), species compositions were determined. Amphipod fauna consisted entirely of non-native species and was dominated by Dikerogammarus villosus in the Main and Echinogammarus trichiatus in the Rhine. However, the availability of amphipod species in the field did not reflect their relative abundance in gut contents of N. melanostomus. Only two metazoan parasites, the nematode Raphidascaris acus and the acanthocephalan Pomphorhynchus sp., were isolated from N. melanostomus in all months, whereas unionid glochidia were only detected in June and October in fish from the Main. To analyse infection pathways, we examined 17,356 amphipods and found Pomphorhynchus sp. larvae only in D. villosus in the river Rhine at a prevalence of 0.15%. Dikerogammarus villosus represented the most important amphipod prey for N. melanostomus in both rivers but parasite intensities differed between rivers, suggesting that final hosts (large predatory fishes) may influence host-parasite dynamics of N. melanostomus in its introduced range.

  1. An Evaluation of Investment in a PV Power Generation Project in the Gobi Desert Using a Real Options Model

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    Yiqing Li

    2018-01-01

    Full Text Available This paper presents a policy benefit model of a photovoltaic (PV power generation project based on real options analysis (ROA and the two-factor learning curve model. The main purpose is to examine the investment behavior of developing a PV project in the Gobi desert considering multiple uncertain factors. We take the environmental cost of desertification control into account for the first time in the literature. Four other uncertain factors are thermal power cost, PV power generation cost, carbon prices, and government subsidy. A binary tree method is applied to solve the proposed model, and we obtain both unit decision value and optimal investment time. Our baseline scenario illustrates that ROA is more effective than net present value (NPV analysis when dealing with uncertainty. Our simulation results show that the government could suffer a loss in accordance with the existing subsidy policy when investing in a PV project. Therefore, the subsidy should be gradually reduced. Finally, the influence of the subsidy policy on decision value is discussed, and an appropriate subsidy is determined accordingly.

  2. COMPARATIVE CHARACTERISTICS OF MORPHOMETRIC PARAMETERS OF MONKEY GOBY (NEOGOBIUS FLUVIATILIS PALLAS OF FRESH AND SALINE WATER RESERVOIRS IN UKRAINE

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    V. P. Onoprienko

    2014-04-01

    physiological processes. The result of this effect is the difference in weight, size and body parts. To clarify, as our model species was taken Cottus Sandpiper (Neogobius fluviatilis Pallas. The reason for this was the fact that this species, along with other Ponto- Caspian solonovato - freshwater gobies, the International Union for Conservation of Nature classified as species biology are poorly understood and require further research. This fact that deepened interest of ichthyologists in this group of fish, in this regard appeared in the literature as material for the bulls and in Sandpiper. Based on the above, the purpose of this paper is a comparative morphometric parameters characteristic of individuals of this species of fresh and salt water bodies of Ukraine. All this affects the absolute morphometric parameters, which decrease in the direction from sea to the river. However, it should be noted that in rivers with rich feeding grounds sheer size of some individuals close to the size and species of sea Kakhovskoe reservoir. This situation is observed in the Sandpiper Grouse River. Here are some specimens reach a length (TL 118-148 mm and a weight of 15-36 g, Kakhovskoe Reservoir: 106-150 mm 11-38 g, in the Sea of ​​Azov: 115-174 mm 17-58 g. For relative parameters Sandpiper with these reservoirs are more similar, however, for some of them, there are differences. Among the latter is most clearly distinguished the ratio SL / N. This indicator podovzhenist (prohonystist body. As pointed out by VP Mitrofanov (1977, this indicator shows the hydrodynamic qualities of fish: the larger the index, the more active lifestyle is individual. When compared with individuals with a little water and a large stream, in the latter case, individuals are more elongated. This is confirmed by our material: the ratio SL / L for the smallest species of sea of ​​Azov (4.96, slightly more for Kakhovsky reservoir (5.52 and even more for rivers Grouse, Trubizh, Desna, Ros (respectively 5, 86

  3. Can environmental conditions affect smallholders' climate change perception? Evidence from an aridity gradient in the Gobi desert.

    Science.gov (United States)

    Rueff, Henri

    2016-04-01

    There is a growing interest in smallholders' climate change perception (CCP). Understanding what people perceive in relation to the climate they endure supports national climate change adaptation policy especially relevant to uncertain and resource-scarce environments. Most research so far focused on the accuracy of CCP compared to observed climatic data. However, the potential effect of factors influencing peoples' perceptions remains largely unstudied. This research tests two hypotheses in a desert environment; first, that CCP varies along an aridity gradient, and, second, that respondents are more consistent (answers less far apart) in their CCP when facing more climate shocks, which supports the first hypothesis. A semi-structured survey was conducted among nomadic (Mongolia) (n=180) and semi-nomadic (Inner Mongolia-China) (n=180) herders, to analyse perception along an aridity gradient (proxied by Normalised Difference Vegetation Index) covering an array of climate change issues in the Gobi. Results suggests that environmental conditions have a significant effect on CCP but only in terms of experienced climate shocks. The CCP for other climatic variables (rain, season length) is more diffused and can poorly be predicted by the surrounding environment smallholders live in. Institutional contrasts between China and Mongolia explain marginally differences of perception. Further research is needed to validate these results among smallholders on other environmental gradient types, for examples along altitudinal biome stratification in mountain environments.

  4. Getting What Is Served? Feeding Ecology Influencing Parasite-Host Interactions in Invasive Round Goby Neogobius melanostomus

    Science.gov (United States)

    Emde, Sebastian; Kochmann, Judith; Kuhn, Thomas; Plath, Martin; Klimpel, Sven

    2014-01-01

    Freshwater ecosystems are increasingly impacted by alien invasive species which have the potential to alter various ecological interactions like predator-prey and host-parasite relationships. Here, we simultaneously examined predator-prey interactions and parasitization patterns of the highly invasive round goby (Neogobius melanostomus) in the rivers Rhine and Main in Germany. A total of 350 N. melanostomus were sampled between June and October 2011. Gut content analysis revealed a broad prey spectrum, partly reflecting temporal and local differences in prey availability. For the major food type (amphipods), species compositions were determined. Amphipod fauna consisted entirely of non-native species and was dominated by Dikerogammarus villosus in the Main and Echinogammarus trichiatus in the Rhine. However, the availability of amphipod species in the field did not reflect their relative abundance in gut contents of N. melanostomus. Only two metazoan parasites, the nematode Raphidascaris acus and the acanthocephalan Pomphorhynchus sp., were isolated from N. melanostomus in all months, whereas unionid glochidia were only detected in June and October in fish from the Main. To analyse infection pathways, we examined 17,356 amphipods and found Pomphorhynchus sp. larvae only in D. villosus in the river Rhine at a prevalence of 0.15%. Dikerogammarus villosus represented the most important amphipod prey for N. melanostomus in both rivers but parasite intensities differed between rivers, suggesting that final hosts (large predatory fishes) may influence host-parasite dynamics of N. melanostomus in its introduced range. PMID:25338158

  5. A new record of Ratan goby - Ponticola ratan (Nordmann, 1840 (Pisces: Gobiidae in the Black Sea, Romanian coastal waters

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    Daniel Cocan

    2016-11-01

    Full Text Available In August 2015 we managed to capture a specimen of ratan goby (Ponticola ratan in the Romanian coastal waters of the Black Sea, near the locality of Sf. Gheorghe (Tulcea County. This is the 7-th signaling for this species in Romanian coastal waters. The previous 6 specimens were recorded in the period 1960-1993, between Mangalia (Constanţa County and Sulina (Tulcea County. The species was identified by means of meristic characters (number of scales on medial line, number of spiny and soft rays, and morphological particularities (cycloid scales on the nape area and pectoral fin joint. Also, the measurements made, confirmed that the ratio between the head length and total length, which was 33% (TL=8.70 cm vs. Head Length=2.61cm. Another morphological character, specific to this species, is the lower jaw, which exceeds in length the upper jaw. Being a Ponto-Caspian endemite, with low population along the Bulgarian and Romanian coastline, we considered it important to point out this new record. Noting that, being known the trend of sporadic migration of this species, would not be excluded that global warming causes a shift from its normal distribution area, from northern and northeastern (Black Sea to south-west. Therefore, future research may bring more notifications regarding this species in south-western area of the Black Sea

  6. Constraining lithospheric removal and asthenospheric input to melts in Central Asia: A geochemical study of Triassic to Cretaceous magmatic rocks in the Gobi Altai (Mongolia)

    Science.gov (United States)

    Sheldrick, Thomas C.; Barry, Tiffany L.; Van Hinsbergen, Douwe J. J.; Kempton, Pamela D.

    2018-01-01

    Throughout northeast China, eastern and southern Mongolia, and eastern Russia there is widespread Mesozoic intracontinental magmatism. Extensive studies on the Chinese magmatic rocks have suggested lithospheric mantle removal was a driver of the magmatism. The timing, distribution and potential diachroneity of such lithospheric mantle removal remains poorly constrained. Here, we examine successions of Mesozoic lavas and shallow intrusive volcanic plugs from the Gobi Altai in southern Mongolia that appear to be unrelated to regional, relatively small-scale deformation; at the time of magmatism, the area was 200 km from any active margin, or, after its Late Jurassic-Early Cretaceous closure, from the suture of the Mongol-Okhotsk Ocean. 40Ar/39Ar radiometric age data place magmatic events in the Gobi Altai between 220 to 99.2 Ma. This succession overlaps Chinese successions and therefore provides an opportunity to constrain whether Mesozoic lithosphere removal may provide an explanation for the magmatism here too, and if so, when. We show that Triassic to Lower Cretaceous lavas in the Gobi Altai (from Dulaan Bogd, Noyon Uul, Bulgantiin Uul, Jaran Bogd and Tsagaan Tsav) are all light rare-earth element (LREE) and large-ion lithophile element (LILE)-enriched, with negative Nb and Ta anomalies (Nb/La and Ta/La ≤ 1). Geochemical data suggest that these lavas formed by low degrees of partial melting of a metasomatised lithospheric mantle that may have been modified by melts derived from recycled rutile-bearing eclogite. A gradual reduction in the involvement of garnet in the source of these lavas points towards a shallowing of the depth of melting after 125 Ma. By contrast, geochemical and isotope data from the youngest magmatic rocks in the area - 107-99 Ma old volcanic plugs from Tsost Magmatic Field - have OIB-like trace element patterns and are interpreted to have formed by low degrees of partial melting of a garnet-bearing lherzolite mantle source. These rocks did

  7. Behavioral and physiological responses to central administration of corticotropin-releasing factor in the bluebanded goby (Lythrypnus dalli).

    Science.gov (United States)

    Solomon-Lane, Tessa K; Grober, Matthew S

    2012-07-16

    Central manipulation of neuromodulators is critical to establishing causal links between brain function and behavioral output. The absence of a rigorous method of evaluating intracerebroventricular (i.c.v.) injection efficacy in small model organisms is one reason why peripheral administration of neuroactive substances is more common. We use the bluebanded goby (Lythrypnus dalli), a small, highly social fish, to 1) validate our method of i.c.v. injection by testing the hypothesis that corticotropin-releasing factor (CRF) elevates ventilation rate (VR) and 2) propose a novel bioassay using basal physiology and behavior during recovery from anesthesia/i.c.v. administration to assess injection efficacy, neuromodulator activity, and procedural confounds. Central CRF administration significantly increased ventilation rate, demonstrating successful delivery of CRF to the brain. There were no significant differences in cortisol among treatments. The injection procedure did, however, decouple the temporal relationship between the initiation of ventilation and time to regain equilibrium present in control fish. Importantly, neither i.c.v. vehicle nor CRF injection affected the initiation of ventilation, disrupted the stereotyped recovery pattern following anesthesia, or initiated an endocrine stress response. Taken together, we suggest that 1) i.c.v. injection can be effectively used to manipulate central levels of CRF in L. dalli and 2) physiological and behavioral recovery from anesthesia may be used to evaluate injection/technique efficacy. We will use these data in future studies as a measure of effective CRF delivery, to allow for appropriate recovery from i.c.v. injection, and to better evaluate independent effects of CRF on social and/or sexual behavior. Copyright © 2012 Elsevier Inc. All rights reserved.

  8. Does sympatry affect trophic resource use in congeneric tidepool fishes? A tale of two gobies Favonigobius lentiginosus and Favonigobius exquisitus.

    Science.gov (United States)

    Chargulaf, C A; Krück, N C; Tibbetts, I R

    2011-12-01

    The feeding ecology of two sympatric gobies, Favonigobius lentiginosus and Favonigobius exquisitus, which inhabit soft substrate pools was studied in Moreton Bay, Australia. Favonigobius spp. and sediment cores were collected from three locations within the bay and fish gut contents were analysed to explore potential competition and ontogenetic dietary shifts. The most abundant prey at all sites was nematodes at 6.33 ± 0.38 cm(-3) at Dunwich, 33.58 ± 0.26 cm(-3) at Manly and 6.36 ± 0.849 cm(-3) (mean ± S.E.) at Godwin Beach. Nevertheless, they were not a dominant component of the diets. Volumetric percent contribution of prey showed that copepods and decapod shrimps dominated F. lentiginosus diets at Dunwich (7.8 and 6.6%, respectively) and Godwin Beach (6.5 and 14.3%, respectively) and the diets of F. exquisitus at Manly (9.2 and 9.5%, respectively) and Godwin Beach (10.4 and 11.8%, respectively). Schoener's index of dietary overlap between the two species, when sympatric, was 0.85 indicating a high similarity. An ontogenetic shift towards larger prey items occurred as Favonigobius spp. reached larger sizes. Gut fullness indices showed significant differences between time of day (two-way ANOVA, P < 0.01) and species (two-way ANOVA, P < 0.05) but Bonferroni's multiple comparison test showed that the only significant difference was between F. lentiginosus at Dunwich and F. exquisitus at Godwin Beach at 1800 hours. Food resource competition and temporal resource partitioning did not appear to be a limiting factor between F. lentiginosus and F. exquisitus despite cohabitation in such restricted environments. © 2011 The Authors. Journal of Fish Biology © 2011 The Fisheries Society of the British Isles.

  9. Devonian and carboniferous arcs of the oyu tolgoi porphyry Cu-Au district, South Gobi region, Mongolia

    Science.gov (United States)

    Wainwright, A.J.; Tosdal, R.M.; Forster, C.N.; Kirwin, D.J.; Lewis, P.D.; Wooden, J.L.

    2011-01-01

    The Central Asian orogenic belt consists of microcontinental blocks and mobile belts positioned between the Siberian craton and the Tarim and North China cratons. Extending across Asia for 5000 km, the belt consists of terranes that decrease in age southward away from the Siberian craton. A time-stratigraphic-structural sequence for the rocks is critical to defining the tectonic evolution of the belt. In the Oyu Tolgoi area of the South Gobi Desert (Mongolia), Devonian and Carboniferous rocks record the construction of multiple arcs, formation of a giant porphyry Cu-Au system, exhumation, and polyphase deformation. The oldest rocks are basaltic volcanic and subvolcanic rocks of the Devonian Alagbayan Group intruded by Late Devonian quartz monzodiorite stocks and dikes, which host giant porphyry Cu-Au deposits. The rocks were exhumed, overlain by pyroclastic rocks, and then tectonically buried by marine mafic supracrustal rocks prior to the youngest Devonian granodiorite intrusions. The postmineral Carboniferous Gurvankharaat Group unconformably overlying the deformed terrane consists of effusive, pyroclastic, subvolcanic and volcaniclastic rocks, as well as sedimentary units. The supracrustal rocks underwent polyphase shortening after 330 Ma and prior to 290 Ma. Variations in stratigraphic sequences suggest that the region is underlain by a submarine arc that became emergent during the Upper Devonian and remained subaerial to shallow subaqueous through much of the Carboniferous. Xenocrystic zircons in igneous rocks suggest that the offshore arcs were sufficiently close to ancient crust to have interacted with detritus shed into marine basins, most likely from the Siberian craton and fringing early Paleozoic terranes. ?? 2011 Geological Society of America.

  10. Effect and mechanism of waterborne prolonged Zn exposure influencing hepatic lipid metabolism in javelin goby Synechogobius hasta.

    Science.gov (United States)

    Huang, Chao; Luo, Zhi; Hogstrand, Christer; Chen, Feng; Shi, Xi; Chen, Qi-Liang; Song, Yu-Feng; Pan, Ya-Xiong

    2016-07-01

    The present study was conducted to determine the effect and mechanism of waterborne Zn exposure influencing hepatic lipid deposition and metabolism in javelin goby Synechogobius hasta. S. hasta were exposed to four waterborne Zn concentrations (Zn 0.005 [control], 0.18, 0.36 and 0.55 mg l(-1) , respectively) for 60 days. Sampling occurred at days 20, 40 and 60, respectively. Zn exposure increased Zn content, declined hepatic lipid content and reduced viscerosomatic and hepatosomatic indices and lipogenic enzyme activities, including 6-phosphogluconate dehydrogenase (6PGD), glucose-6-phosphate dehydrogenase (G6PD), malic enzyme (ME) and fatty acid synthase (FAS). At days 20 and 60, Zn exposure decreased hepatic mRNA levels of 6PGD, G6PD, ME, FAS, acetyl-CoA carboxylase (ACC)α, ACCβ, hormone-sensitive lipase (HSL)a, HSLb, sterol-regulator element-binding protein (SREBP)-1, peroxisome proliferators-activated receptor (PPAR)α and PPARγ. However, the mRNA levels of CPT 1 and adipose triglyceride lipase increased following Zn exposure. On day 40, Zn exposure reduced hepatic mRNA expression of 6PGD, G6PD, ME, FAS, ACCα, ACCβ, HSLa, HSLb, SREBP-1 and PPARγ but increased mRNA expression of CPT 1, adipose triglyceride lipase and PPARα. General speaking, Zn exposure reduced hepatic lipid content by inhibiting lipogenesis and stimulating lipolysis. For the first time, the present study provided evidence that chronic Zn exposure differentially influenced mRNA expression and activities of genes and enzymes involved in lipogenic and lipolytic metabolism in a duration-dependent manner, and provided new insight into the relationship between metal elements and lipid metabolism. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.

  11. Relação proteína:carboidrato no desempenho e no metabolismo de híbridos de Pseudoplatystoma fasciatum (fêmea X Leiarius marmoratus (macho

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    S.A. Souza

    2014-06-01

    Full Text Available Objetivou-se, neste trabalho, determinar a melhor relação entre proteína e carboidrato na dieta do híbrido carnívoro Pseudoplatystoma fasciatum e Leiarius marmoratus. Utilizou-se um sistema fechado de recirculação de água, composto de 12 caixas de 500L e biofiltro. Foram utilizados 144 juvenis (12/caixa com peso médio inicial de 12,63±2,52g e comprimento total de 12,34±2,06cm durante 50 dias. Os peixes receberam quatro dietas contendo diferentes relações proteína:carboidrato (1,24; 0,84; 0,56 e 0,33. A relação proteína:carboidrato influenciou o desempenho e os parâmetros metabólicos dos animais. A melhor relação proteína:carboidrato para o desempenho foi 0,84. Os resultados metabólicos demonstraram mobilização de nutrientes para manutenção de glicemia e do crescimento. A relação proteína:carboidrato de 0,84 foi a mais indicada para o híbrido.

  12. Changes in brain arginine vasotocin, isotocin, plasma 11-ketotestosterone and cortisol in round goby, Neogobius melanostomus, males subjected to overcrowding stress during the breeding season.

    Science.gov (United States)

    Sokołowska, Ewa; Kleszczyńska, Agnieszka; Kalamarz-Kubiak, Hanna; Arciszewski, Bartłomiej; Kulczykowska, Ewa

    2013-06-01

    In natural spawning grounds, breeding round goby, Neogobius melanostomus, males are exposed to various social stimuli, including high density of same-sex competitors and separation from females. We hypothesize that breeding males subjected to overcrowding in the wild experience high stress that affects their socio-sexual behavior and their relationships among conspecifics. We designed an experiment to mimic natural stimulation when highly aggregated breeding males are subjected to same-sex opponents. Males were sampled sequentially from experimental tank stocked at decreasing fish densities of 15 fish/m(2), 9 fish/m(2) and 4 fish/m(2). We studied the effects of overcrowding on male behavior and selected hormones, brain arginine vasotocin (AVT) and isotocin (IT) and plasma 11-ketotestosterone (11-KT) and cortisol as these are known to play roles in reproduction and related social interactions. The highest brain AVT and plasma cortisol levels were measured in non-aggressive males kept in the overcrowded group of 15 fish/m(2). IT level was elevated in fish kept at the lower density of 9 fish/m(2), and at which the males began to display territoriality and aggression. The plasma level of 11-KT was similar in all the males. Brain AVT and IT and plasma cortisol along with behavioral observations can be applied as species-specific indicators of the well-being of round goby males. Copyright © 2013 Elsevier Inc. All rights reserved.

  13. Seasonal diet pattern of non-native tubenose goby (Proterorhinus semilunaris in a lowland reservoir (Mušov, Czech Republic

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    Adámek Z.

    2010-08-01

    Full Text Available The tubenose goby (Proterorhinus semilunaris is a gobiid species currently extending its area of distribution in Central Europe. The objective of the study was to evaluate the annual pattern of its feeding habits in the newly colonised habitats of the Mušov reservoir on the Dyje River (the Danube basin, Czech Republic with respect to natural food resources. In the reservoir, tubenose goby has established a numerous population, densely colonising stony rip-rap banks. Its diet was exclusively of animal origin with significant dominance of and preference for two food items – chironomid (Chironomidae larvae and waterlouse (Asellus aquaticus, which contributed 40.2 and 27.6%, respectively, to the total food bulk ingested. The index of preponderance for the two items was also very high, amounting to 73.8 and 26.5, respectively. In the annual pattern, a remarkable preference for chironomid larvae was recorded in the summer period whilst waterlouse were consumed predominantly in winter months. The proportion of other food items was rather marginal – only corixids, copepods, ceratopogonids and cladocerans were of certain minor importance with proportions of 5.4, 4.3, 4.1 and 3.9%, respectively. Certain signs of cannibalism were also recorded, with 0.9 and 0.2% of the diet consisting of their own progeny and eggs, respectively.

  14. Przewalski’ s Horse ( Equus ferus przewalskii Re-intr oduction in the Great Gobi B Strictly Protected Area: from Species to Ecosystem Conservation

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    P. Kaczensky

    2007-05-01

    Full Text Available The Przewalski’s horse ( Equus ferus przewalskii Po ljakov , 1881, or “T akhi” in Mongolian, became extinct in the wild by the mid 1960’ s. The last recorded sightings of Przewalski’s horses occurred in the Dzungarian Gobi desert in SW Mo ngolia, today’s Great Gobi B Strictly Protected Area (SP A. A re - introduction program was initiated in 1992 and the fi rs t group of captive-born Przewalski’s horses was airlifted to the SPA. Given the logistical challenges associated with such a venture, the initial project focus has been on transport logistics and the well-being of the re-introduced horses. Tod ay, conservation efforts are spread over the entire protected area. Present day ef forts include other mammals, vegetation and the local people. Due to its important symbolic value in Mongolian culture, the Przewalski’ s horse became an important fl agship species for the protected area’s conservation and management.

  15. Vigorous Dynamics Underlie a Stable Population of the Endangered Snow Leopard Panthera uncia in Tost Mountains, South Gobi, Mongolia

    Science.gov (United States)

    Sharma, Koustubh; Bayrakcismith, Rana; Tumursukh, Lkhagvasumberel; Johansson, Orjan; Sevger, Purevsuren; McCarthy, Tom; Mishra, Charudutt

    2014-01-01

    Population monitoring programmes and estimation of vital rates are key to understanding the mechanisms of population growth, decline or stability, and are important for effective conservation action. We report, for the first time, the population trends and vital rates of the endangered snow leopard based on camera trapping over four years in the Tost Mountains, South Gobi, Mongolia. We used robust design multi-season mark-recapture analysis to estimate the trends in abundance, sex ratio, survival probability and the probability of temporary emigration and immigration for adult and young snow leopards. The snow leopard population remained constant over most of the study period, with no apparent growth (λ = 1.08+−0.25). Comparison of model results with the “known population” of radio-collared snow leopards suggested high accuracy in our estimates. Although seemingly stable, vigorous underlying dynamics were evident in this population, with the adult sex ratio shifting from being male-biased to female-biased (1.67 to 0.38 males per female) during the study. Adult survival probability was 0.82 (SE+−0.08) and that of young was 0.83 (SE+−0.15) and 0.77 (SE +−0.2) respectively, before and after the age of 2 years. Young snow leopards showed a high probability of temporary emigration and immigration (0.6, SE +−0.19 and 0.68, SE +−0.32 before and after the age of 2 years) though not the adults (0.02 SE+−0.07). While the current female-bias in the population and the number of cubs born each year seemingly render the study population safe, the vigorous dynamics suggests that the situation can change quickly. The reduction in the proportion of male snow leopards may be indicative of continuing anthropogenic pressures. Our work reiterates the importance of monitoring both the abundance and population dynamics of species for effective conservation. PMID:25006879

  16. Competitive relationship between members of the Gobiidae family and other fish species of waters of Pridneprovye region

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    V. V. Khobot

    2014-09-01

    Full Text Available The paper analyzes the species’ composition of Gobiidae, their quantitative and qualitative parameters in the coastal zone of the Pridneproovye water bodies. The structural and functional features of organization of coastal Gobies groups in the explored territory have been investigated, as well as characteristics of spatial arrangement of Gobiidae family representatives in water bodies and rivers and their role in the coastal groups of fishes. In the waters of Dnipropetrovsk region there were recorded 8 species of the Gobies family: round goby Neogobius melanostomus (Pallas, 1814, big-headed goby N. kessleri (Gunter, 1861, monkey goby N. fluviatilis (Pallas, 1814, goad goby N. gymnotrachelus (Kessler, 1857, toad goby Mesogobius batrachocephalus (Pallas, 1814, tube-nosed goby Proterorhinus marmoratus (Pallas, 1814, starry goby Benthophilus stellatus (Sauvage, 1874, Brauner’s tadpole goby Benthophiloides brauneri (Beling et Iljin, 1927. The gobies are quickly settled in various water bodies. The highest numbers of Gobiidae were registered in Dneprovsky water basin – 113.8 specimens/100 m2. The dominant among the Gobiidae is monkey goby, and subdominant is round goby. The main food competitor of monkey goby are juveniles of commercial fish. In Samara river the index of trophic niche overlap between goby and roach reaches 0.95, between goby and silver bream – 0.91, between goby and crucian carp – 0.88, between goby and rudd – 0.87, between goby and common bream – 0.62. The number and biomass indicators in Samara river have fallen due to trophic competition between new aggressive fish species – pumpkinseed and Gobiidae. In the Ingulets river the total overlap of trophic niches is observed between N. fluviatilis and black-striped pipefish (1.0, almost complete overlap is recorded between monkey goby and pumpkinseed (0.97. It is found that native species of Dnipropetrovsk region (including commercial species undergo intense trophic

  17. COMPARATIVE CHARACTERISTICS OF MORPHOMETRIC PARAMETERS OF MONKEY GOBY (NEOGOBIUS FLUVIATILIS PALLAS OF FRESH AND SALINE WATER RESERVOIRS IN UKRAINE

    Directory of Open Access Journals (Sweden)

    Onoprienko V.

    2014-04-01

    physiological processes. The result of this effect is the difference in weight, size and body parts. To clarify, as our model species was taken Cottus Sandpiper (Neogobius fluviatilis Pallas. The reason for this was the fact that this species, along with other Ponto- Caspian solonovato - freshwater gobies, the International Union for Conservation of Nature classified as species biology are poorly understood and require further research. This fact that deepened interest of ichthyologists in this group of fish, in this regard appeared in the literature as material for the bulls and in Sandpiper. Based on the above, the purpose of this paper is a comparative morphometric parameters characteristic of individuals of this species of fresh and salt water bodies of Ukraine. All this affects the absolute morphometric parameters, which decrease in the direction from sea to the river. However, it should be noted that in rivers with rich feeding grounds sheer size of some individuals close to the size and species of sea Kakhovskoe reservoir. This situation is observed in the Sandpiper Grouse River. Here are some specimens reach a length (TL 118-148 mm and a weight of 15-36 g, Kakhovskoe Reservoir: 106-150 mm 11-38 g, in the Sea of Azov: 115-174 mm 17-58 g. For relative parameters Sandpiper with these reservoirs are more similar, however, for some of them, there are differences. Among the latter is most clearly distinguished the ratio SL / N. This indicator podovzhenist (prohonystist body. As pointed out by VP Mitrofanov (1977, this indicator shows the hydrodynamic qualities of fish: the larger the index, the more active lifestyle is individual. When compared with individuals with a little water and a large stream, in the latter case, individuals are more elongated. This is confirmed by our material: the ratio SL / L for the smallest species of sea of Azov (4.96, slightly more for Kakhovsky reservoir (5.52 and even more for rivers Grouse, Trubizh, Desna, Ros (respectively 5, 86, 6.22 , 6

  18. Triassic to Cenozoic multi-stage intra-plate deformation focused near the Bogd Fault system, Gobi Altai, Mongolia

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    Douwe J.J. van Hinsbergen

    2015-09-01

    Full Text Available The Gobi Altai region of southern Mongolia has been in the Eurasian plate interior since the mid-Mesozoic, yet has experienced episodic phases of deformation since that time. In this paper, we document field evidence to characterize and date the intra-plate tectonic history of the Gobi Altai region from the Triassic to the present. To this end, we provide detailed mapping of the structure and stratigraphy of the eastern flanks of Mt. Ih Bogd that contains the widest variety of rock-time units in the area. We carry out geochronological analysis of basaltic lavas and basement granite in the area. We demonstrate that a crystalline basement with a 502 ± 8 Ma granitoid (U/Pb underwent two phases of basin formation in the Mesozoic, which we date with new 40Ar/39Ar lava ages of 218.5 ± 1.5, 123.2 ± 0.7 and 124.8 ± 1.2 Ma, respectively. Both phases are linked to deposition of fluvio-lacustrine sediments and trap-like basaltic volcanics, with cumulative thicknesses of 1000–1500 m. Both basins were likely north-facing half-grabens that developed under ∼N–S extension, but were subsequently overthrusted by Paleozoic and older crystalline basement during a less well constrained, but likely mid-Cretaceous phase of N–S shortening and basin inversion. Our results are consistent with recent seismic imaging of rift basins ∼100 km to the NE of the study area where a similar history was reconstructed. The multiple phases of intra-plate deformation appear to have parallel structural trends, most likely due to reactivated Paleozoic basement structures created during the original terrane amalgamation of the Central Asian Orogenic Belt continental crust. This strong basement heterogeneity may predispose it to reactivation, and make it sensitive to changes in the overall stress field of the Eurasian plate driven by forces at its margins and base. Detailed study of Mongolia's multi-stage tectonic history may thus provide a key proxy for the long

  19. Morphological and molecular identification of Gyrodactylus bubyri Osmanov, 1965 (Monogenea: Gyrodactylidae) from Caucasian dwarf goby, Knipowitschia caucasica (Berg) (Actinopterygii: Gobionellidae) from a Black Sea lagoon.

    Science.gov (United States)

    Stoyanov, Borislav; Huyse, Tine; Pankov, Plamen; Georgiev, Boyko B

    2016-04-01

    Gyrodactylus bubyri Osmanov, 1965, a monogenean parasite of Caucasian dwarf goby Knipowitschia caucasica (Berg) described from Aral Sea and subsequently reported from the same host from Strymon River, Greece, is recorded from Atanasovsko Lake, Bulgarian Black Sea coast (the first record of G. bubyri from the Black Sea basin). The species is redescribed by light and scanning electron microscopy as well as the ITS rDNA sequence is obtained. As comparative materials, specimens of G. bubyri from K. caucasica (Strymon River), G. charon Vanhove and Huyse in Vanhove et al., 2014 from Knipowitschia milleri (Acheron Delta, Greece) and G. micropsi Gläser, 1974 from Potamoschistus microps from North Sea (Belgium) are studied. Comparative morphology and molecular data demonstrate that G. micropsi is a junior synonym of G. bubyri (new synonymy). The validity of G. charon is questioned, pending examination of additional materials in order to prove it as a distinct species or as a junior synonym of G. bubyri.

  20. Early Engagement of Stakeholders with Individual-Based Modeling Can Inform Research for Improving Invasive Species Management: The Round Goby as a Case Study

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    Emma Samson

    2017-11-01

    Full Text Available Individual-based models (IBMs incorporating realistic representations of key range-front processes such as dispersal can be used as tools to investigate the dynamics of invasive species. Managers can apply insights from these models to take effective action to prevent further spread and prioritize measures preventing establishment of invasive species. We highlight here how early-stage IBMs (constructed under constraints of time and data availability can also play an important role in defining key research priorities for providing key information on the biology of an invasive species in order that subsequent models can provide robust insight into potential management interventions. The round goby, Neogobius melanostomus, is currently spreading through the Baltic Sea, with major negative effects being reported in the wake of its invasion. Together with stakeholders, we parameterize an IBM to investigate the goby's potential spread pattern throughout the Gulf of Gdansk and the Baltic Sea. Model parameters were assigned by integrating information obtained through stakeholder interaction, from scientific literature, or estimated using an inverse modeling approach when not available. IBMs can provide valuable direction to research on invasive species even when there is limited data and/or time available to parameterize/fit them to the degree to which we might aspire in an ideal world. Co-development of models with stakeholders can be used to recognize important invasion patterns, in addition to identifying and estimating unknown environmental parameters, thereby guiding the direction of future research. Well-parameterized and validated models are not required in the earlier stages of the modeling cycle where their main utility is as a tool for thought.

  1. Delivering oxytetracycline to first-feeding zebrafish, Danio rerio (Hamilton), and goby, Asterropteryx semipunctata Rüppell, larvae using lipid spray beads.

    Science.gov (United States)

    Temple, E; Langdon, C

    2009-03-01

    Lipid spray beads (LSB) were evaluated for delivery of the low-molecular weight, water-soluble antibiotic, oxytetracycline.HCl (OTC) to fish larvae. Various OTC core-to-lipid ratios and OTC core concentrations were evaluated to maximize OTC delivery efficiency by LSB. Acceptability and digestion of LSB containing OTC and riboflavin by larval zebrafish, Danio rerio (Hamilton), and larval gobies, Asterropteryx semipunctata Rüppell, were also evaluated. Increasing LSB core-to-lipid ratios from 1:3 to 1:1 v/v resulted in an increase in encapsulation efficiency (EE) from 2.33 to 3.68% w/w. Increasing OTC concentrations of core solutions from 0.1 to 0.5 g OTC mL(-1) increased EE from 3.95 to 18.77% w/w, respectively. Although retention efficiency (RE) was unaffected by this increase, delivery efficiency was increased to 7.9 +/- 0.7% w/w, after correcting for leakage losses because of the suspension of beads in water for 60 min. Consumption of LSB containing OTC by first-feeding zebrafish and goby larvae was confirmed by analysis of feeding incidence and gut fullness. Visual observations of larvae fed on LSB containing riboflavin indicated that larvae of both species digested LSB. Zebrafish larvae fed on OTC LSB contained 39.3 +/- 2.5 ng OTC after purging LSB from their guts. Use of LSB provides an effective means of delivering therapeutics to fish larvae and could greatly reduce required doses compared with current methods of immersing larvae in solutions of therapeutic agents.

  2. Review of the Distribution of the Family Gobiidae (Pisces in the Bulgarian Danube Tributaries

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    Velislav Y. Zarev

    2013-12-01

    Full Text Available The current study aims to give in detailed information on the actual distribution of the species from family Gobiidae in the Bulgarian Danube tributaries. All known literature has been revised and with the new data collected is given complete and actual information on their distribution. In the period 2010-2012 were sampled a total of 41 sites alongside each one of the Bulgarian Danube tributaries. The sampling started from the river mouths to upstream in order to discover what is the southern (upstream distribution of each one goby species. Four goby species were recorded from the tributaries – the round goby (Neogobius melanostomus Pallas, 1814, the monkey goby (Neogobius fluviatilis, the racer goby (Neogobius gymnotrachelus and the tubenose goby (Proterorhinus marmoratus. Further analysis showed preference of mixed substrates and silt in addition of homogenous ones. The occurrence of gobies in the studied tributaries decreased inversely proportional to distance from Danube.

  3. [The parasite fauna and structures of parasite communities of Oreoleuciscus humilis Warpachowski, 1889 from Ust-Nur Lake (Selenga River basin) and Tuin-Gol River (Goby Lakes Valley)].

    Science.gov (United States)

    Batueva, M D

    2011-01-01

    The parasite fauna of Oreoleuciscus humilis from the Ust-Nur Lake (Selenga River basin), Tuin-Gol River (Goby Lakes Valley) are given for the first time. We found 9 species of Oreoleuciscus humilis parasites, 5 species is revealed for the first time for this host. Infracommunities of parasites of Oreoleuciscus humilis in the Tuin-Gol River are balanced and mature, in the Ust-Nur Lake are not balaced and not mature.

  4. First field-based observations of δ2H and δ18O values of precipitation and other water bodies in the Mongolian Gobi desert

    Science.gov (United States)

    Burnik Šturm, Martina; Ganbaatar, Oyunsaikhan; Voigt, Christian C.; Kaczensky, Petra

    2017-04-01

    Hydrogen (δ2H) and oxygen (δ18O) isotope values of water are widely used to track the global hydrological cycle and the global δ2H and δ18O patterns of precipitation are increasingly used in studies on animal migration, forensics, food authentication and traceability studies. However, δ2H and δ18O values of precipitation spanning one or more years are available for only a few 100 locations worldwide and for many remote areas such as Mongolia data are still scarce. We obtained the first field-based δ2H and δ18O isotope data of event-based precipitation, rivers and other water bodies in the extreme environment of the Dzungarian Gobi desert in SW Mongolia, covering a period of 16 months (1). Our study area is located over 450 km north-east from the nearest IAEA GNIP station (Fukang station, China) from which it is separated by a mountain range at the international border between China and Mongolia. Isotope values of the collected event-based precipitation showed and extreme range and a high seasonal variability with higher and more variable values in summer and lower in winter. The high variability could not be explained by different origin of air masses alone (i.e. NW polar winds over Russia or westerlies over Central Asia; analyzed using back-trajectory HYSPLIT model), but is likely a result of a combination of different processes affecting the isotope values of precipitation in this area. The calculated field-based local meteoric water line (LMWL, δ2H=(7.42±0.16)δ18O-(23.87±3.27)) showed isotopic characteristics of precipitation in an arid region. We observed a slight discrepancy between the filed based and modelled (Online Isotope in Precipitation Calculator, OIPC) LMWL which highlighted the difficulty of modelling the δ2H and δ18O values for areas with extreme climatic conditions and thus emphasized the importance of collecting long-term field-based data. The collected isotopic data of precipitation and other water bodies provide a basis for future

  5. Evolutionary history of a widespread Indo-Pacific goby: the role of Pleistocene sea-level changes on demographic contraction/expansion dynamics.

    Science.gov (United States)

    Hoareau, Thierry Bernard; Boissin, Emilie; Berrebi, Patrick

    2012-01-01

    Compared to endemics, widespread species are of particular interest to retrace recent evolutionary history. These species have a large population size which provides a clearer genetic signature of past events. Moreover, their wide geographic range increases the potential occurrence of evolutionary events (expansion, divergence, etc.). Here, we used several coalescent-based methods to disentangle the evolutionary history of a widespread amphidromous goby (Sicyopterus lagocephalus), in the light of sea-level variations during the Pleistocene. Using 75 samples recovered from three biogeographic regions (Western Indian Ocean, Melanesia and Polynesia), we analysed a portion of the cytochromeb gene and confirmed three major haplogroups, each specific to a region. Furthermore, we found that: (1) the Melanesian haplogroup was the oldest while the two peripheral regions hosted daughter haplogroups; (2) two centrifugal colonisation events occurred from Melanesia to the periphery, each synchronised with periods of strong paleo-ENSO episodes; (3) the demographic contraction-expansion events were linked to Pleistocene sea-level changes; (4) Melanesia and Polynesia acted as efficient refuges during the Last Glacial Maximum. These results highlight the importance of studying widespread species to better understand the role of climate changes and paleo-oceanography on the evolution of biodiversity. Copyright © 2011 Elsevier Inc. All rights reserved.

  6. Landscape dynamics assessment of dry climatic zones on the Baikal-Gobi transect from NDVI time series and field investigations data

    Science.gov (United States)

    Sayapina, D. O.; Zharnikova, M. A.; Tsydypov, B. Z.; Sodnomov, B. V.; Garmaev, E. Zh

    2016-11-01

    Starting in the eighties of the 20th century, the scientists of the Baikal Institute of Nature Management (BINM SB RAS) have been conducting field observations of the Transbaikalia geosystems transformation due to the change of climate and nature management. An utmost importance is placed on the study of a negative response of the land geosystems. This is shown through their deterioration, degradation, and desertification in particular. Through the years of research (1985-2015) in dry areas of the north of Central Asia, the scientists of the BINM SB RAS established a network of key sites for contact monitoring of the status and dynamics of the geosystems and the negative natural-anthropogenic processes along the Baikal-Gobi meridional transect (51-44° N, 105-107° E). The monitoring of the status and dynamics of the vegetation cover of some key sites is conducted by processing and analysis of multitemporal and multispectral Landsat and MODIS Terra imagery. An automatic analysis of the time variation of NDVI and a comparison with the progress of the index in the previous seasons are performed. The landscape indication of the key sites is made on the basis of satellite imagery and complete geobotanical descriptions. Landscape profiles and facies maps with natural boundaries are created.

  7. Serum osmolality and ions, and gill Na+/K+-ATPase of spottedtail goby Synechogobius ommaturus (R. in response to acute salinity changes

    Directory of Open Access Journals (Sweden)

    Chun Shui

    2018-03-01

    Full Text Available This study was carried out to determine the effects of abrupt salinity change on osmoregulatory ability of the spottedtail goby Synechogobius ommaturus. 720 juvenile fish (65.3 ± 11.8 g were transferred to 200 L tanks (with 40 juveniles in each tank, in which salinities were abruptly changed from 10 to 20, 30, 40, 50 and freshwater. Survival rate, serum osmolality, electrolytes (Na+, Cl−, and K+ and gill Na+/K+-ATPase (NKA activity were assessed successively in 528 h. Results showed serum osmolality, ion concentrations and gill Na+/K+-ATPase activity increased significantly when fish were transferred to salinity 40 and 50 and all fish in these groups died by the end of the experiment. Serum osmolality, Na+, Cl− and K+ in fish transferred to a salinity of 20, 30 and freshwater were not affected and no mortality was detected. Compared with the control group, a significantly decrease of NKA activity happened in the freshwater group, but the activity in 20 and 30 groups was not affected significantly. The results indicated that S. ommaturus could adapt rapidly and maintain homeostasis in a wide range of salinities (from freshwater to salinity 30 and this species may be suitable for aquaculture in estuarine and coastal areas where rapid salinity fluctuations commonly occur. Keywords: Osmolality, Gill, Na+/K+-ATPase, Synechogobius ommaturus

  8. [Evaluation of the efficacity of coconut (Cocos nucifera), palm nut (Eleais guineensis) and gobi (Carapa procera) lotions and creams in indivirual protection against Simulium damnosum s.l. bites in Côte d'Ivoire].

    Science.gov (United States)

    Sylla, M; Konan, L; Doannio, J M; Traoré, S

    2003-05-01

    With the interruption of larva treatments done by OCP as part of onchocerciasis control in West Africa, Simulium came back in abundance in forest regions and savannah fertile valleys. In addition to the severe discomfort, nuisance by Simulium is in certain cases incompatible with land use. Since ground treatment of larval breading sites using insecticides is not always possible or efficient, it is therefore a necessity to develop other methods among which individual protection against Simulium bites. The general objective of our study was to evaluate different vegetable oil compound repellent formulas against Simulium bites. Activities were carried out in savannah zone (Niakaramandougou) and in forest zone (Soubré) in Côte d'Ivoire. The methodology consisted in catching blackflies on volunteers whose legs were rubbed with a repellent. Gobi raw oil and coconut, palm nut and gobi formulas (lotions and creams) were tested. During each session, which lasted from 07:00 am to 12:00 and from 03:00 pm to 06:00 pm, one person did not apply any repellent and was used as the control person. The results of our experimentations show that for a given zone (savannah, forest), a repellent (coconut, palm nut, gobi) and a compound (shea butter, vaseline), there is no significant difference between protection rates obtained with lotions (maximum: 21 bites/person/day) and those obtained with creams (maximum: 30 bites/person/day). In other respects, the lotion of a given repellent seems to be efficient in savannah as in the forest, in protecting against Simulium bites. It is the same situation with creams. So, repellents can be an efficient solution against Simulium nuisance. However, experimentations should continue to confirm the high repellency of tested formulas, proceed to the identification of principles and evaluate the toxicity and irritant effect of repellents to be applied on the skin.

  9. Application of otolith shape analysis for stock discrimination and species identification of five goby species (Perciformes: Gobiidae) in the northern Chinese coastal waters

    Science.gov (United States)

    Yu, Xin; Cao, Liang; Liu, Jinhu; Zhao, Bo; Shan, Xiujuan; Dou, Shuozeng

    2014-09-01

    We tested the use of otolith shape analysis to discriminate between species and stocks of five goby species ( Ctenotrypauchen chinensis, Odontamblyopus lacepedii, Amblychaeturichthys hexanema, Chaeturichthys stigmatias, and Acanthogobius hasta) found in northern Chinese coastal waters. The five species were well differentiated with high overall classification success using shape indices (83.7%), elliptic Fourier coefficients (98.6%), or the combination of both methods (94.9%). However, shape analysis alone was only moderately successful at discriminating among the four stocks (Liaodong Bay, LD; Bohai Bay, BH; Huanghe (Yellow) River estuary HRE, and Jiaozhou Bay, JZ stocks) of A. hasta (50%-54%) and C. stigmatias (65.7%-75.8%). For these two species, shape analysis was moderately successful at discriminating the HRE or JZ stocks from other stocks, but failed to effectively identify the LD and BH stocks. A large number of otoliths were misclassified between the HRE and JZ stocks, which are geographically well separated. The classification success for stock discrimination was higher using elliptic Fourier coefficients alone (70.2%) or in combination with shape indices (75.8%) than using only shape indices (65.7%) in C. stigmatias whereas there was little difference among the three methods for A. hasta. Our results supported the common belief that otolith shape analysis is generally more effective for interspecific identification than intraspecific discrimination. Moreover, compared with shape indices analysis, Fourier analysis improves classification success during inter- and intra-species discrimination by otolith shape analysis, although this did not necessarily always occur in all fish species.

  10. Journal of Genetics | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Genetics; Volume 96; Online resources. Population genetic diversity of marble goby (Oxyeleotris marmoratus)inferred from mitochondrial DNA and microsatellite analysis. CHENG ZHAO XIAOPING ZHU YICHUN GU QINTAO WANG ZECHENG LI SHAOWU YIN. ONLINE RESOURCES Volume 96 ...

  11. First field-based observations of δ2H and δ18O values of event-based precipitation, rivers and other water bodies in the Dzungarian Gobi, SW Mongolia.

    Science.gov (United States)

    Burnik Šturm, Martina; Ganbaatar, Oyunsaikhan; Voigt, Christian C; Kaczensky, Petra

    2017-05-01

    For certain remote areas like Mongolia, field-based precipitation, surface and ground water isotopic data are scarce. So far no such data exist for the Mongolian Gobi desert, which hinders the understanding of isotopic fractionation processes in this extreme, arid region. We collected 26 event-based precipitation samples, 39 Bij river samples, and 75 samples from other water bodies in the Dzungarian Gobi in SW Mongolia over a period of 16 months for hydrogen and oxygen stable isotope analysis. δ 2 H and δ 18 O values in precipitation show high seasonal variation and cover an extreme range: 175 ‰ for δ 2 H and 24 ‰ for δ 18 O values. The calculated local meteoric water line (LMWL) shows the isotopic characteristics of precipitation in an arid region. Individual water samples fall into one of three groups: within, above or below the 95 % confidence interval of LMWL. Data presented provide a basis for future studies in this region.

  12. Linking remote-sensing and ecosystem services modeling to support and assess management for regenerative grazing in the South Gobi, Mongolia

    Science.gov (United States)

    Chaplin-Kramer, R.; Kowal, V. A.; Sharp, R.

    2017-12-01

    Managing and monitoring supply chain sustainability is a major challenge and opportunity for business, especially in rangelands, heavily managed and often degraded natural systems that provide significant resources and raw materials for production. One of the largest and most threatened rangeland systems in the world is in Mongolia, which has seen a rapid rise in grazing pressure due to increasing global demand for cashmere along with privatization of a formerly government-run livestock industry. A new opportunity is emerging for remote-sensing to improve the management decisions of the producers and their incentive-setters, leading to a more sustainable rangeland system and better outcomes for biodiversity and people in this unique and imperiled landscape. Oyu Tolgoi (OT), the Mongolian subsidiary of the mining company Rio Tinto, in cooperation with Kering, an apparel conglomerate that sources cashmere from the region, are providing financial incentives to improve grazing patterns through a Sustainable Cashmere program, in order to restore the degraded rangeland ecosystem in the Gobi desert region. We present a framework and approach for predicting the effect of changing grazing practices on biodiversity and ecosystem services, which we are developing into decision-support tools for OT, Kering, and their local partner Wildlife Conservation Society to quantify the impacts of their programs and where these interventions will have greatest benefit. Our approach integrates remote-sensing and ecosystem modeling to scale up field monitoring data and forecast future impacts. Our rangeland production model, based on the soil-vegetation model CENTURY and the livestock model GRAZPLAN, predicts biomass production and plant species composition changes, and can feed into ecosystem services models such as soil retention and water regulation in the InVEST (Integrated Valuation of Ecosystem Services and Trade-offs) software suite. This presents a significant advance in ecosystem

  13. Measurement of scattering and absorption properties of dust aerosol in a Gobi farmland region of northwestern China - a potential anthropogenic influence

    Science.gov (United States)

    Bi, Jianrong; Huang, Jianping; Shi, Jinsen; Hu, Zhiyuan; Zhou, Tian; Zhang, Guolong; Huang, Zhongwei; Wang, Xin; Jin, Hongchun

    2017-06-01

    We conducted a comprehensive field campaign to explore the optical characteristics of mineral dust in Dunhuang farmland near the Gobi Desert of northwest China during spring of 2012. The day-to-day and diurnal variations of dust aerosol showed prominent features throughout the experiment, primarily attributable to frequent dust events and local anthropogenic emissions. The overall average mass concentrations of the particulate matter with an aerodynamic diameter less than 10 µm (PM10), light scattering coefficient (σsp, 670), absorption coefficient (σap, 670), and single-scattering albedo (SSA670) were 113 ± 169 µg m-3, 53.3 ± 74.8 Mm-1, 3.2 ± 2.4 Mm-1, and 0.913 ± 0.05, respectively, which were comparable to the background levels in the southern United States but smaller than those in the eastern and other northwestern Chinese cities. The anthropogenic dust produced by agricultural cultivations (e.g., land planning, plowing, and disking) exerted a significant superimposed effect on high dust concentrations in Dunhuang farmland prior to the growing season (i.e., from 1 April to 10 May). Strong south valley wind and vertical mixing in daytime scavenged the pollution, and the weak northeast mountain wind and stable inversion layer at night favorably accumulated the air pollutants near the surface. In the afternoon (13:00-18:00 LT, local time), mean SSA670 was 0.945 ± 0.04 predominantly from dust particles, whereas finer particles and lower SSA670 values ( ˜ 0.90-0.92) were measured at night, suggesting the potential influence by the mixed dust pollutants. During a typical biomass burning event on 4 April 2012, σap, 670 increased from ˜ 2.0 to 4.75 Mm-1 and SSA670 changed from ˜ 0.90 to ˜ 0.83, implying remarkable modification of aerosol absorptive properties induced by human activities. The findings of this study would help to advance an in-depth understanding of the interaction among dust aerosol, atmospheric chemistry, and climate change in a desert

  14. Impact of Gobi desert dust on aerosol chemistry of Xi'an, inland China during spring 2009: differences in composition and size distribution between the urban ground surface and the mountain atmosphere

    Directory of Open Access Journals (Sweden)

    G. H. Wang

    2013-01-01

    Full Text Available Composition and size distribution of atmospheric aerosols from Xi'an city (~400 m, altitude in inland China during the spring of 2009 including a massive dust event on 24 April were measured and compared with a parallel measurement at the summit (2060 m, altitude of Mt. Hua, an alpine site nearby Xi'an. EC (elemental carbon, OC (organic carbon and major ions in the city were 2–22 times higher than those on the mountaintop during the whole sampling period. Compared to that in the non-dust period a sharp increase in OC was observed at both sites during the dust period, which was mainly caused by an input of biogenic organics from the Gobi desert. However, adsorption/heterogeneous reaction of gaseous organics with dust was another important source of OC in the urban, contributing 22% of OC in the dust event. In contrast to the mountain atmosphere where fine particles were less acidic when dust was present, the urban fine particles became more acidic in the dust event than in the non-dust event, mainly due to enhanced heterogeneous formation of nitrate and diluted NH3. Cl and NO3 in the urban air during the dust event significantly shifted toward coarse particles. Such redistributions were further pronounced on the mountaintop when dust was present, resulting in both ions almost entirely staying in coarse particles. On the contrary, no significant spatial difference in size distribution of SO42− was found between the urban ground surface and the mountain atmosphere, which dominated in the fine mode (<2.1 μm during the nonevent and comparably distributed in the fine (<2.1 μm and coarse (>2.1 μm modes during the dust event.

  15. Hypoxia increases the risk of egg predation in a nest-guarding fish

    DEFF Research Database (Denmark)

    Olsson, Karin; Kvarnemo, Charlotta; Andrén, Maria Norevik

    2016-01-01

    For fish with parental care, a nest should meet both the oxygenation needs of the eggs and help protect them against predators. While a small nest opening facilitates the latter, it impedes the former and vice versa. We investigated how the presence of potential egg predators in the form of shore...... in high oxygen reduced fanning, males in low oxygen did not. Filial cannibalism was unaffected by treatment. Sand gobies thus prioritize egg ventilation over the protection afforded by small nest openings under hypoxia and adopt defensive behaviour to avert predator attention, even though this does...... crabs Carcinus maenas affects nest building, egg fanning, defensive displays and filial cannibalism of egg-guarding male sand gobies Pomatoschistus minutus under two levels of dissolved oxygen. In the high oxygen treatment, males retained their nest opening size in the presence of crabs, while males...

  16. Detrital zircon and sandstone provenance analysis from Permian and Lower Cretaceous sedimentary units to constrain total and incremental left-lateral offset along the East Gobi Fault Zone, southeastern Mongolia

    Science.gov (United States)

    Heumann, M.; Johnson, C.; Webb, L.; Taylor, J.

    2008-12-01

    This study presents initial U-Pb detrital zircon geochronology results coupled with sandstone provenance point-counting to constrain sedimentary basin evolution along the East Gobi Fault Zone (EGFZ), southeastern Mongolia. These results fingerprint potential piercing points in sedimentary units argued here to have once been part of the same depositional basins, now offset by the strike-slip fault zone. Detrital zircon samples were collected and analyzed using LA-ICPMS from two sets of proposed offset-basin systems: Permian fluvial and marine units at Bulgan Uul and Nomgon, and Cretaceous fluvial units at Tavan Har and Ulgay Khid (11 sandstone samples total). The age probability plots for Bulgan Uul and Nomgon, as well as Tavan Har and Ulgay Khid, show very convincing correlations with significant implications. The Late Permian Lugyn Gol units at Nomgon are currently ~270 km northeast of those Late Permian Onch Uul samples at Bulgan Uul, and provide similar age probability plots, with most significant peaks at ~280 Ma and ~440 Ma, for zircons of igneous origins based on U/Th ratios. Lower Cretaceous strata from Tavan Har and Ulgay Khid are currently located ~90 km left-laterally off-set from each other, and also show strong correlation with significant age probability peaks centered at ~280 Ma and ~120 Ma, also with igneous origins. As the detrital zircon data are not intended to stand alone, 23 samples including all the zircon samples were point-counted for establishing provenance. QFL ternary plots indicate semi-mature, recycled orogen and arc sources for samples collected at Bulgan Uul, Nomgon, and Ulgay Khid. Tavan Har, however, primarily plotted in the dissected arc field. The results presented here argue for the following three main findings: First, detrital zircon analysis shows a clear connection of Bulgan Uul and Nomgon, as well as Ulgay Khid and Tavan Har. These cross-fault stratigraphic connections are further supported in most cases by the provenance

  17. Food conditions of the sand goby

    NARCIS (Netherlands)

    Freitas, V.; Lika, K.; Witte, J.IJ.; van der Veer, H.W.

    2011-01-01

    Several epibenthic species aggregate in large numbers in shallow waters during summer, feeding on the available benthic meio- and macrofauna. Whether this concentration leads to periods of food limitation affecting habitat quality for some of these species is not clear at present. In this study we

  18. História natural dos amborés e peixes-macaco (Actinopterygii, Blennioidei, Gobioidei do Parque Nacional Marinho do Arquipélago de Fernando de Noronha, sob um enfoque comportamental Natural history focus blennies and gobis behaviour (Actinopterygii, Blennioidei, Gobioidei from Fernando de Noronha Archipelago

    Directory of Open Access Journals (Sweden)

    Liana de F. Mendes

    2006-09-01

    Full Text Available Os amborês e peixes-macaco, como são popularmente conhecidos gobiídeos e bleniídeos, são elementos dominantes da fauna de pequenos peixes bentônicos e litorâneos que habitam recifes tropicais, compondo grande parte da alta diversidade das espécies de pequeno porte encontrada no Atlântico ocidental. O estudo da distribuição e história natural dos gobióides e blenióides de Fernando de Noronha foi desenvolvido através de observações de campo. Além da descrição dos hábitats preferenciais foram abordados aspectos sociais tais como, habitat preferencial, interações intra- e interespecíficas, comportamento domiciliar e territorial, e comportamento reprodutivo. A maioria das espécies em foco apresenta distribuição principalmente litorânea, são gregárias, com áreas domiciliares relativamente pequenas em torno de 2 x 2 m², pouco agressivas, tendo sido ocasionalmente registradas curtas perseguições intra- e interespecíficas. A baixa agressividade registrada, em comparação com outros peixes é provavelmente associada à adaptação à ocupação de pequenas áreas, como é o caso das poças de marés, pois um grande número de interações agressivas representaria um gasto de energia desnecessário. No geral, as espécies possuem coloração críptica, associada à evitação de predadores. Apenas nestas épocas de reprodução foi observada a intensificação da agressividade, com comportamento territorial - defesa de território incluindo mordidas e perseguições.The gobis and blenis (Gobiidae and Bleniidae are the most important group of small benthic littoral fishes in tropical reefs, representing most of the high number of small fish species found in Western Atlantic. The natural history of gobiid and bleniid fish from Fernando de Noronha was assessed by means observation sessions using both snorkelling and scuba diving. Most of these observations were aimed at social behaviour, such as intra and interespecific

  19. Body size mediates social and environmental effects on nest building behaviour in a fish with paternal care.

    Science.gov (United States)

    Lehtonen, Topi K; Lindström, Kai; Wong, Bob B M

    2015-07-01

    Body size, social setting, and the physical environment can all influence reproductive behaviours, but their interactions are not well understood. Here, we investigated how male body size, male-male competition, and water turbidity influence nest-building behaviour in the sand goby (Pomatoschistus minutus), a marine fish with exclusive paternal care. We found that environmental and social factors affected the nest characteristics of small and large males differently. In particular, association between male size and the level of nest elaboration (i.e. the amount of sand piled on top of the nest) was positive only under clear water conditions. Similarly, male size and nest entrance size were positively associated only in the absence of competition. Such interactions may, in turn, help to explain the persistence of variation in reproductive behaviours, which-due to their importance in offspring survival-are otherwise expected to be under strong balancing selection.

  20. The effect of meal size on gastric evacuation in whiting

    DEFF Research Database (Denmark)

    Andersen, Niels Gerner

    1998-01-01

    Gastric evacuation experiments were performed on whiting Merlangius merlangus fed discrete meals of different sizes. Herring Clupea harengus, sandeel Ammodytes tobianus, common goby Pomatoschistus microps, and brown shrimp Crangon crangon were tested as prey. A simple power model to describe gast...... into account in the estimation procedure by expressing stomach contents relative to meal size. (C) 1998 The Fisheries Society of the British Isles.......36-0.77 for the different prey. The power estimates in the simple model were generally close to 0.5. The exception was crustacean prey, which gave a higher value. In the simple model the power estimate represents a compromise between the curvatures of the curves fitted to the observations for each meal size...

  1. The effect of meal size on gastric evacuation in whiting

    DEFF Research Database (Denmark)

    Andersen, Niels Gerner

    1998-01-01

    Gastric evacuation experiments were performed on whiting Merlangius merlangus fed discrete meals of different sizes. Herring Clupea harengus, sandeel Ammodytes tobianus, common goby Pomatoschistus microps, and brown shrimp Crangon crangon were tested as prey. A simple power model to describe...... gastric evacuation was evaluated and compared with a power model expanded as a function of meal size. The model parameters were estimated by means of nonlinear least squares. When all meal sizes were included the estimates of the power (curvature) parameter in the expanded model were within the range 0.......36-0.77 for the different prey. The power estimates in the simple model were generally close to 0.5. The exception was crustacean prey, which gave a higher value. In the simple model the power estimate represents a compromise between the curvatures of the curves fitted to the observations for each meal size...

  2. Status Review of the Marbled Murrelet (Brachyramphus marmoratus) in Alaska and British Columbia

    Science.gov (United States)

    2006-01-01

    conservation NGO that provides scientific information to help guide conservation actions. NatureServe and its network of natural heritage programs provide...species: Gland, Switzerland. World Conservation Union, 2004, Red list of threatened species: Gland, Switzerland. Wright, S., 1931, Evolution in Mendelian

  3. Morphological differences in the skin of marble trout Salmo marmoratus and of brown trout Salmo trutta

    Czech Academy of Sciences Publication Activity Database

    Sivka, U.; Halačka, Karel; Sušnik Bajec, S.

    2012-01-01

    Roč. 50, č. 2 (2012), s. 255-262 ISSN 0239-8508 R&D Projects: GA AV ČR 1QS500450513 Institutional support: RVO:68081766 Keywords : melanophore * epidermis * dermis * colour pattern * pigmentation Subject RIV: EG - Zoology Impact factor: 1.101, year: 2012 http://czasopisma.viamedica.pl/fhc/article/view/14750

  4. Daily feeding periodicity of the intertidal goby Caffrogobius caffer

    African Journals Online (AJOL)

    en laagwater. Voedsel is dwarsdeur die dag ingeneem en daar is 'n effense neiging tot hoogtepunte in die voedingsaktiwiteit gedurende skemertye. S.·Afr. Tydskr. ... These two phenomena, tide and light intensi- ty, might be expected to have an effect on the feeding periodicity of C. coffer. Twenty-four-hour collections were ...

  5. Chromosomal polymorphism in the goby Neogobius eurycephalus (Perciformes: Gobiidae)

    Czech Academy of Sciences Publication Activity Database

    Ene, Cristina

    2003-01-01

    Roč. 142, - (2003), s. 583-588 ISSN 0025-3162 R&D Projects: GA AV ČR IAA6045704 Institutional research plan: CEZ:AV0Z5045916 Keywords : neogobius eurycephalus Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 1.841, year: 2003

  6. Broad chromosomal polymorphism in the goby Neogobius eurycephalus (Perciformes: Gobiidae)

    Czech Academy of Sciences Publication Activity Database

    Ene, A. C.; Rábová, Marie; Ráb, Petr; Suciu, R.

    2004-01-01

    Roč. 106, č. 1 (2004), s. 23 ISSN 1424-8581. [European Colloquium on Animal Cytogenetics and Gene Mapping/16./. 06.07.2004-09.07.2004, Jouy-en-Josas] R&D Projects: GA AV ČR IBS5045111 Grant - others:ANSTI(RO) 6146 Keywords : Neogobius eurycephalus Subject RIV: EB - Genetics ; Molecular Biology

  7. Paleolakes in the Gobi region of southern Mongolia

    Science.gov (United States)

    Lehmkuhl, Frank; Grunert, Jörg; Hülle, Daniela; Batkhishig, Ochirbat; Stauch, Georg

    2018-01-01

    Numerous lakes and remnants of paleolakes exist in western and southern Mongolia. For six basins in the area, detailed geomorphological maps were compiled, based on extensive field studies and remote sensing datasets. Several phases of high and low lake levels were reconstructed and dated by radiocarbon and optically stimulated luminescence. During the marine isotope stage (MIS) 6 lakes in southern and western Mongolia mostly disappeared. In contrast, large paleolakes existed during the last interglacial (MIS 5e) and lasted probably until the beginning of the last glacial. These huge lakes were caused by a strong East Asian summer monsoon, which reached southern and even western Mongolia. During the MIS 3 the monsoon was considerably weaker and most of the lakes were relatively small or even disappeared. Higher lake levels of this period were only recorded at the Orog Nuur. However, at this time the lake was fed by glacial melt water from the Khangai Mountains. The MIS 2 was again a very dry period. The previously supposed phase of synchronous high lake levels and glaciations in southern and western Mongolia is not supported by the data presented here. During the Holocene, lakes in the western and southern part of the study area evolved differently. Early Holocene high lake levels were reconstructed for the western lakes, while most of the southern lakes had highest lake levels in the mid-Holocene. These differences can be attributed to different moisture bearing atmospheric systems. In the late Holocene lake levels were generally low and in the last 50 years most lakes completely disappeared due to a strong human usage of the water resources.

  8. A NEW FRESHWATER GOBY (TELEOSTEI: GOBIIDAE) FROM THE ...

    African Journals Online (AJOL)

    497. JUDB, R. A. 1967. Freshwater fishes of southern Africa. Cape Town: Balkema. KOUMANS, F. P. 1931. A preliminary revision of the genera of the gobioidfishes with united ventral fins. N. V. Lisse. (Netherlands) 1-174: Drukkerij, Imperator. R.

  9. Dual impact of temperature on growth and mortality of marine fish larvae in a shallow estuarine habitat

    Science.gov (United States)

    Arula, Timo; Laur, Kerli; Simm, Mart; Ojaveer, Henn

    2015-12-01

    High individual growth and mortality rates of herring Clupea harengus membras and goby Pomatoschistus spp. larvae were observed in the estuarine habitat of the Gulf of Riga, Baltic Sea. Both instantaneous mortality (0.76-1.05) as well as growth rate (0.41-0.82 mm day-1) of larval herring were amongst highest observed elsewhere previously. Mortality rates of goby larvae were also high (0.57-1.05), while first ever data on growth rates were provided in this study (0.23-0.35 mm day-1). Our study also evidenced that higher growth rate of marine fish larvae did not result in lower mortalities. We suggest that high growth and mortality rates primarily resulted from a rapidly increasing and high (>18 °C) water temperature that masked potential food-web effects. The explanation for observed patterns lies in the interactive manner temperature contributed: i) facilitating prey production, which supported high growth rate and decreased mortalities; ii) exceeding physiological thermal optimum of larvae, which resulted in decreased growth rate and generally high mortalities. Our investigation suggests that the projected climate warming may have significant effect on early life history stages of the dominating marine fish species inhabiting shallow estuaries.

  10. Preliminary Insight into Winter Native Fish Assemblages in Guadiana Estuary Salt Marshes Coping with Environmental Variability and Non-Indigenous Fish Introduction

    Directory of Open Access Journals (Sweden)

    Renata Gonçalves

    2017-10-01

    Full Text Available This work aims to undertake a preliminary characterization of winter fish assemblages in the salt marsh areas of Guadiana lower estuary (South-East Portugal and discusses the potential risks of habitat dominance by a non-indigenous species (NIS. To this effect, six field campaigns were carried out in four sampling sites during winter season targeting the collection of fish species. A total of 48 samples were collected. Individuals from seven different taxa (marine and estuarine were collected, although the assemblage was dominated by two estuarine species—the native Pomatoschistus sp. (goby and the NIS Fundulus heteroclitus (mummichog. Goby was the most abundant taxa in the majority of salt marsh habitats, except for one specific, marsh pool, where extreme environmental conditions were registered, namely high temperature and salinity. Such conditions may have boosted the intrusion of mummichog in this area. This species is well adapted to a wide range of abiotic factors enabling them to colonize habitats where no predators inhabit. Impacts of mummichog introduction in the Guadiana salt marsh area are still unpredictable since this is the first time they have been recorded in such high density. Nevertheless, in scenarios of increased anthropogenic pressure and, consequently, habitat degradation, there is a potential risk of mummichog spreading to other habitats and therefore competing for space and food resources with native species.

  11. Does the invasive plant Elymus athericus modify fish diet in tidal salt marshes?

    Science.gov (United States)

    Laffaille, P.; Pétillon, J.; Parlier, E.; Valéry, L.; Ysnel, F.; Radureau, A.; Feunteun, E.; Lefeuvre, J.-C.

    2005-12-01

    The invasion of Mont-Saint-Michel Bay salt marshes (France) by a grass species ( Elymus athericus) has led to important changes in vegetation cover, which is likely to modify the habitat for many invertebrates. Some of them constitute the main food items for several fish species, such as young sea bass ( Dicentrarchus labrax) and sand goby ( Pomatoschistus minutus), that feed in salt marsh creeks during high tides. As a result, fish nursery functions of salt marshes could be modified by the E. athericus invasion. In order to test this hypothesis, gut contents of the two most abundant fish species (sea bass and sand goby) were compared before and after E. athericus invasion in the same salt marsh creek and using the same methodology. The accessibility and availability of the main food item, the semi-terrestrial amphipod Orchestia gammarella, were estimated and compared between invaded (dominated by E. athericus) and original areas (dominated by Atriplex portulacoides). Gut content analysis showed a significantly greater percentage of fish leaving with empty guts from E. athericus areas than from A. portulacoides areas. The sea bass diet composition study showed a major shift in the relative importance of the main food items: before E. athericus invasion, diets were dominated by the semi-terrestrial species O. gammarella, whereas after the E. athericus invasion they were dominated by a marine mysid Neomysis integer. The same trend was found for sand gobies, with a shift of the main food item from O. gammarella before invasion to the polychaete Hediste diversicolor after invasion. These trophic changes may be explained by the lower accessibility and availability of O. gammarella in invaded communities than in natural ones. The E. athericus invasion, observed throughout northern Europe, is thus likely to disturb trophic function of natural salt marshes for fish. This preliminary study of the E. athericus invasion is also an illustration that invasive species are an

  12. Fish mortality by impingement on the cooling-water intake screens of Britain's largest direct-cooled power station.

    Science.gov (United States)

    Greenwood, M F D

    2008-04-01

    An estimated 5.66 x 10(7) fish (summed quarterly 95% confidence intervals: 3.01 x 10(7)-1.07 x 10(8)) weighing 258.4 t (143.2-467.9 t) were killed on the cooling-water intake screens of the 2400 MW Longannet Power Station (Forth estuary) in January 1999--December 2000. Abundance and number of species (40) collected were close to predictions for a power station of this size and latitude. Potential losses of equivalent adult whiting (Merlangius merlangus), cod (Gadus morhua), and plaice (Pleuronectes platessa) through deaths of juveniles were estimated at 353.1 t (208.0-603.2 t) worth approximately euro 429,266 (euro 246,592-752,765) in 1999--2000. Fish catch-per-trawl in the estuary was generally not noticeably greater during a year of low water withdrawal (coal miners' strike of 1984--1985) when compared to other years from 1982 to 2001, except for gobies (Pomatoschistus spp.). A fish-return system is being tested at Longannet to reduce mortality.

  13. Fish community structure and distribution in a macro-tidal inshore habitat in the Irish Sea

    Science.gov (United States)

    Jovanovic, Boris; Longmore, Craig; O'Leary, Áine; Mariani, Stefano

    2007-10-01

    Estuaries, lagoons and mudflat habitats represent a crucial biodiversity component in coastal waters and may act as vital nurseries and shelters for the juvenile stages of many commercial fish species. A study of the spatial distribution of inshore fish fauna around the shallow coastal habitats of North Bull Island (Dublin Bay, Ireland) was carried out during summer and autumn of 2005, in order to characterise the fish community present therein. Four stations were examined, situated along a putative environmental gradient, between the mudflat and the open sea shore. Stations were surveyed at both high and low tide and sampling was repeated weekly for eight weeks, spanning over four spring and four neap tidal events. A total of 17 fish species were caught, belonging to 13 families. The community was largely dominated by the lesser sandeel ( Ammodytes tobianus) and the common goby ( Pomatoschistus microps). Ordination techniques were used to generate hypotheses as to the general patterns in the fish community; Shannon-Wiener index was employed to estimate spatial, temporal and tidal trends in diversity; and analysis of variance (ANOVA) was employed to test for the influence of time of the year, habitat, tidal phase and tidal state on the spatial distribution of fishes. Results reveal that time of the year and habitat variation across the environmental gradient are the major factors in determining fish community structure. The influence of tidal dynamics seem to have a lesser impact on the overall community, but can significantly and variably affect the distribution of individual species.

  14. First record of the twostripe goby, Valenciennea helsdingenii (Gobiidae, Gobiiformes from the southeast coast of India

    Directory of Open Access Journals (Sweden)

    Kannan K

    2013-08-01

    Full Text Available Two specimens of Valenciennea helsdingenii (Bleeker, 1858 were collected off Punnakayal coast, from Gulf of Mannar, southeast coast of India in November 2012. The morphometric and meristic characters of the recorded specimens are described and discussed. This is the first record of the species from the Indian waters that is a range extension of its known range within the Indian Ocean.

  15. Microhabitat Influence on Larval Fish Assemblages Within Vegetated Beds: Implications for Tubenose Goby Detection and Invasion

    Science.gov (United States)

    We examined larval and juvenile fish assemblage structure in relation to microhabitat variables within the St. Louis River estuary, a drowned river mouth of Lake Superior. Fish were sampled in vegetated beds throughout the estuary, across a gradient of vegetation types and densit...

  16. Temporal effects on host-parasite associations in four naturalized goby species living in sympatry

    Czech Academy of Sciences Publication Activity Database

    Ondračková, Markéta; Valová, Zdenka; Hudcová, Iveta; Michálková, Veronika; Šimková, A.; Borcherding, J.; Jurajda, Pavel

    2015-01-01

    Roč. 746, č. 1 (2015), s. 233-243 ISSN 0018-8158 R&D Projects: GA ČR(CZ) GAP505/12/2569 Institutional support: RVO:68081766 Keywords : Fish * Gobiidae * Non-native species * Parasite * Rhine Subject RIV: EG - Zoology Impact factor: 2.051, year: 2015

  17. Carcass feeding as a cryptic foraging mode in round goby Neogobius melanostomus

    Czech Academy of Sciences Publication Activity Database

    Polačik, Matej; Jurajda, Pavel; Blažek, Radim; Janáč, Michal

    2015-01-01

    Roč. 87, č. 1 (2015), s. 194-199 ISSN 0022-1112 R&D Projects: GA ČR(CZ) GAP505/11/1768 Institutional support: RVO:68081766 Keywords : diet * food web * necrophagy * trophic ecology Subject RIV: EG - Zoology Impact factor: 1.246, year: 2015

  18. Expansion of round gobies in a non-navigable river system

    Czech Academy of Sciences Publication Activity Database

    Šlapanský, Luděk; Janáč, Michal; Roche, Kevin Francis; Mikl, Libor; Jurajda, Pavel

    2017-01-01

    Roč. 67, November (2017), s. 27-36 ISSN 0075-9511 R&D Projects: GA ČR(CZ) GAP505/11/1768 Institutional support: RVO:68081766 Keywords : Impact * Invasive species * Neogobius melanostomus * Pioneer fish * Population characteristics * Proterorhinus semilunaris Subject RIV: EH - Ecology, Behaviour OBOR OECD: Marine biology, freshwater biology, limnology Impact factor: 1.427, year: 2016

  19. A newly established round goby (Neogobius melanostomus) population in the upper stretch of the river Elbe

    Czech Academy of Sciences Publication Activity Database

    Roche, Kevin Francis; Janáč, Michal; Šlapanský, Luděk; Mikl, Libor; Kopeček, Lukáš; Jurajda, Pavel

    2015-01-01

    Roč. 416, č. 33 (2015), s. 33 ISSN 1961-9502 R&D Projects: GA ČR(CZ) GAP505/11/1768 Institutional support: RVO:68081766 Keywords : Gobiidae * species introduction * non-native species * population expansion * ship-mediated transport Subject RIV: EH - Ecology, Behaviour Impact factor: 0.978, year: 2015

  20. Investigations into the diet and feeding ecology of the bearded goby ...

    African Journals Online (AJOL)

    Given the importance of this species in recycling benthic carbon through the foodweb of the northern Benguela ecosystem, there is a need to describe and quantify the benthic food environment. Keywords: Benguela, benthic-pelagic coupling, ecosystem approach to fisheries, infauna, polychaetes, zooplankton

  1. Invasive Ponto-Caspian gobies in the diet of piscivorous fish in a European lowland river

    Czech Academy of Sciences Publication Activity Database

    Mikl, Libor; Adámek, Zdeněk; Roche, Kevin Francis; Všetičková, Lucie; Šlapanský, Luděk; Jurajda, Pavel

    2017-01-01

    Roč. 190, č. 2 (2017), s. 157-171 ISSN 1863-9135 R&D Projects: GA ČR(CZ) GBP505/12/G112 Institutional support: RVO:68081766 Keywords : invasive gobiids * fish prey * predatory fish diet * food web structure * invasive species impacts Subject RIV: EG - Zoology OBOR OECD: Marine biology, freshwater biology, limnology Impact factor: 1.170, year: 2016

  2. Assessment of possible diel and sex-related differences in round goby (Neogobius melanostomus) diet

    Czech Academy of Sciences Publication Activity Database

    Všetičková, Lucie; Janáč, Michal; Roche, Kevin Francis; Jurajda, Pavel

    2015-01-01

    Roč. 64, č. 2 (2015), s. 104-111 ISSN 0139-7893 R&D Projects: GA ČR(CZ) GAP505/11/1768 Institutional support: RVO:68081766 Keywords : invasive species * diel feeding * inter-sex differences * nest-guarding * breeding season Subject RIV: EG - Zoology Impact factor: 0.592, year: 2015

  3. Invasive gobies in the Danube: invasion success facilitated by availability and selection of superior food resources

    Czech Academy of Sciences Publication Activity Database

    Polačik, Matej; Janáč, Michal; Jurajda, Pavel; Adámek, Zdeněk; Ondračková, Markéta; Trichkova, T.; Vassilev, M.

    2009-01-01

    Roč. 18, č. 4 (2009), s. 640-649 ISSN 0906-6691 R&D Projects: GA MŠk LC522 Grant - others:National Science Fund(BG) B-1510/05 Institutional research plan: CEZ:AV0Z60930519 Keywords : Apollonia * food availability * Bivalvia * invasion success * zebra mussel Subject RIV: EH - Ecology, Behaviour Impact factor: 1.512, year: 2009

  4. STIPHODON JULIENI, A NEW SPECIES OF FRESHWATER GOBY (TELEOSTEI: GOBIOIDEI: SICYDIINAE FROM RAPA, FRENCH POLYNESIA.

    Directory of Open Access Journals (Sweden)

    KEITH P.

    2002-01-01

    Full Text Available Stiphodon julieni, new species, is described on the basis of 8 specimens collected from a high gradient stream on Rapa in French Polynesia. Stiphodon julieni, new species, is the largest species of Stiphodon known to occur in French Polynesia and is distinguished from all other congeners in French Polynesia by the following combination of characteristics: predorsal midline with 10-14 cycloid scales; lateral scales 31-36 reaching upper pectoral base; transverse series back (TRB 8-9; transverse series forward (TRF 9-12; upper jaw teeth 33-38.

  5. LENTIPES KAAEA, A NEW SPECIES OF FRESHWATER GOBY (TELEOSTEI: GOBIOIDEI: SICYDIINAE FROM NEW CALEDONIA.

    Directory of Open Access Journals (Sweden)

    WATSON R. E.

    2002-01-01

    Full Text Available Lentipes kaaea, new species, is described on the basis of 28 specimens collected from high gradient streams occurring in eastern slope region of North Province on New Caledonia and streams in the island nation of Vanuatu. Lentipes kaaea, new species, is distinguished from all other congeners by the following combination of characteristics: males and females with a single pair of fleshy lobes associated with and attached basally with urogenital papilla, lobes always apparent in males and only apparent in gravid females; usually 17 (17-18 pectoral rays; usually 10 (9-10 segmented rays in second dorsal fin; caudal peduncle with cycloid scales, few ctenoid scales may be present along midline in females, between belly and first dorsal fin ctenoid scales with 3 to 5 large spike like ctenii present on males and absent in females; cephalic sensory pore system with pores A, B, C, D, F, H, K, L, N and O, pore D singular with all other pores paired, oculoscapular canal divided into posterior and anterior canals between pores H and K; males bright red to purplish on head and on posterior half of body, second dorsal fin with a black spot between spine and ray 1, individuals may have more than one spot present, first dorsal fin bluish to purplish and usually without spots, anal fin reddish to purplish basally and bluish distally; females usually whitish with variable tan to brownish markings that may include a distinct lateral band and a spot at medial base of caudal fin, above midline dusky bars and bands may be present, dusky saddles may be present dorsally, fin rays and spines with basal half slightly brownish and distally without pigment, membrane in all fins generally clear.

  6. The diet of reservoir perch before, during and after establishment of non-native tubenose goby

    Czech Academy of Sciences Publication Activity Database

    Všetičková, Lucie; Mikl, Libor; Adámek, Zdeněk; Prášek, Václav; Roche, Kevin Francis; Jurajda, Pavel

    2018-01-01

    Roč. 419, č. 419 (2018), č. článku 4. ISSN 1961-9502 R&D Projects: GA ČR(CZ) GBP505/12/G112 Institutional support: RVO:68081766 Keywords : dietary shift * food preference * Gobiidae * invasive species * Perca fluviatilis * piscivore diet Subject RIV: EG - Zoology Impact factor: 1.217, year: 2016

  7. Globalising Assessment: An Ethnography of Literacy Assessment, Camels and Fast Food in the Mongolian Gobi

    Science.gov (United States)

    Maddox, Bryan

    2014-01-01

    What happens when standardised literacy assessments travel globally? The paper presents an ethnographic account of adult literacy assessment events in rural Mongolia. It examines the dynamics of literacy assessment in terms of the movement and re-contextualisation of test items as they travel globally and are received locally by Mongolian…

  8. 78 FR 8745 - Endangered and Threatened Wildlife and Plants; Designation of Critical Habitat for Tidewater Goby

    Science.gov (United States)

    2013-02-06

    ... greater coastal erosion (Scripps Institution of Oceanography 2012, p. 24) and reach farther inland than... 5 coastal lagoon populations (Lake Earl, Stone Lagoon, Big Lagoon, Virgin Creek, and Pudding Creek... contrast, the study found that, while coastal lagoon populations also exhibited very high levels of genetic...

  9. A new genus of proteocephalid tapeworm (Cestoda) from the marbled swamp eel Synbranchus marmoratus Bloch (Synbranchiformes: Synbranchidae) in the River Parana basin, Argentina

    Czech Academy of Sciences Publication Activity Database

    Arredondo, N.J.; Alves, Philippe Vieira; Gil de Pertierra, A.A.

    2017-01-01

    Roč. 64, MAY 5 (2017), č. článku 015. ISSN 1803-6465 R&D Projects: GA ČR(CZ) GBP505/12/G112 Institutional support: RVO:60077344 Keywords : Proteocephalidae * Monticelliinae * taxonomy * morphology * phylogenetic analysis * freshwater * Neotropical Region Subject RIV: GJ - Animal Vermins ; Diseases, Veterinary Medicine OBOR OECD: Veterinary science Impact factor: 1.082, year: 2016

  10. Molecular and cytogenetic analyses of cryptic species within the Synbranchus marmoratus Bloch, 1795 (Synbranchiformes: Synbranchidae grouping: species delimitations, karyotypic evolution and intraspecific diversification

    Directory of Open Access Journals (Sweden)

    Ricardo Utsunomia

    Full Text Available The fish species Synbranchus marmoratushas been reported to exist as a species complex due to high intraspecific karyotypic variability in spite of the difficulty or impossibility to distinguish them using morphological traits alone. The goal of this work was to use cytogenetic and molecular methods to determine the species delimitations and understand the karyoevolution ofS. marmoratususing samples collected from distinct Brazilian localities. Among the analyzed specimens, a large degree of cytogenetic variation related to diploid numbers and karyotype structure was observed, with karyotypes showing 2n=42, 44 and 46 chromosomes. In addition, using sequences of three mitochondrial genes, the phylogenetic relationships between every sample with a known karyotype were determined, which revealed significant nucleotide divergence among the karyomorphs. Also, the analyses indicate that chromosomal rearrangements occurred independently within the distinct lineages of S. marmoratuscomplex, which resulted in the appearance of distinct karyotypic variants in a non-linear fashion related to diploid numbers and in the appearance of similar non-homologous chromosomes. Finally, the integration of both molecular cytogenetic and phylogenetic approaches allowed the determination of specific chromosomes possibly involved in rearrangements and a better understanding about the evolutionary processes involved in the differentiation ofSynbranchusgenus.

  11. 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.

  12. Cryptic species of Ponto-Caspian bighead goby of the genus Ponticola (Gobiidae)

    DEFF Research Database (Denmark)

    Vasil'eva, E. D.; Schwarzhans, Werner; Medvedev, D. A.

    2016-01-01

    Based on karyological data, the validity of the species Ponticola iljini is re-established; its distribution is limited to the coast of the Mangyshlak Peninsula. The morphological characteristics and the basic color pattern of P. iljini are very similar to P. kessleri from the Black Sea basin and P....... gorlap which inhabits the northern, western, and southern Caspian Sea. These three allopatric species have ctenoid scales to varying degrees on the crown and nape (100% presence in P. kessleri and complete absence in P. iljini), and there are small differences in the shape of the head, the thickness...... of the caudal peduncle, and in the form of otoliths; at the same time, they are clearly differentiated by the number of chromosomes and the presence of marker submetacentric chromosomes in P. iljini. In the phylogenetic tree based on the variation of the mitochondrial cytochrome b gene in the main species...

  13. Pelagic occurrence and diet of invasive round goby Neogobius melanostomus (Actinopterygii, Gobiidae) juveniles in deep well-mixed European reservoirs.

    Czech Academy of Sciences Publication Activity Database

    Jůza, Tomáš; Zemanová, Jana; Tušer, Michal; Sajdlová, Zuzana; Baran, Roman; Vašek, Mojmír; Ricard, Daniel; Blabolil, Petr; Wagenvoort, A. J.; Ketelaars, H. A. M.; Kubečka, Jan

    2016-01-01

    Roč. 768, č. 1 (2016), s. 197-209 ISSN 0018-8158 R&D Projects: GA MŠk(CZ) EE2.3.20.0204; GA MŠk(CZ) EE2.3.30.0032 Institutional support: RVO:60077344 Keywords : Biesbosch reservoirs * fish community composition changes * invasive species * vertical distribution * length distribution * fry trawling Subject RIV: EH - Ecology, Behaviour Impact factor: 2.056, year: 2016

  14. The parasite community of round goby Neogobius melanostomus (Pallas, 1814) (Actinopterygii: Gobiidae) newly introduced into the upper Elbe

    Czech Academy of Sciences Publication Activity Database

    Kvach, Yuriy; Ondračková, Markéta; Janáč, Michal; Jurajda, Pavel

    2017-01-01

    Roč. 418, April (2017), č. článku 19. ISSN 1961-9502 R&D Projects: GA ČR(CZ) GBP505/12/G112 Institutional support: RVO:68081766 Keywords : enemy release hypothesis * Neogobius melanostomus * North Sea basin * parasite spillback * Pomphorhynchus tereticollis Subject RIV: EG - Zoology OBOR OECD: Marine biology , freshwater biology , limnology Impact factor: 1.217, year: 2016

  15. Non-native western tubenose gobies Proterorhinus semilunaris show distinct site, sex and age-related differences in diet

    Czech Academy of Sciences Publication Activity Database

    Všetičková, Lucie; Janáč, Michal; Vašek, Mojmír; Roche, Kevin Francis; Jurajda, Pavel

    2014-01-01

    Roč. 414, č. 10 (2014), s. 1-19 ISSN 1961-9502 R&D Projects: GA ČR(CZ) GAP505/11/1768 Institutional support: RVO:68081766 Keywords : invasive species * Gobiidae * Proterorhinus semilunaris * diet * site-effect * sex-differences Subject RIV: EG - Zoology Impact factor: 0.928, year: 2014

  16. Reproductive behaviour and embryonic development of the Citrinis Clown Goby (Gobiodon citrinus and Blue Sapphire Damselfish (Chrysiptera springeri

    Directory of Open Access Journals (Sweden)

    João Chambel

    2014-06-01

    The development of captive breeding techniques for targeted aquaculture species requires a sound knowledge of their gamete physiology, embryology, and early larval ontogeny and this study provides for the first time technical information about breeding of G. citrinus and C. springeri and this can be a start point for the captive breeding of this species.

  17. No effect of round goby Neogobius melanostomus colonisation on young-of-the-year fish density or microhabitat use

    Czech Academy of Sciences Publication Activity Database

    Janáč, Michal; Valová, Zdenka; Roche, Kevin Francis; Jurajda, Pavel

    2016-01-01

    Roč. 18, č. 8 (2016), s. 2333-2347 ISSN 1387-3547 R&D Projects: GA ČR(CZ) GAP505/11/1768 Institutional support: RVO:68081766 Keywords : Invasive species * Niche shift * Neogobius melanostomus * Proterorhinus semilunaris * Impact Subject RIV: EH - Ecology , Behaviour Impact factor: 2.473, year: 2016

  18. Invasion rate and population characteristics of the invasive round goby Neogobius melanostomus: effects of density and invasion history

    DEFF Research Database (Denmark)

    Azour, Farivar; Deurs, Mikael van; Behrens, Jane

    2015-01-01

    ). The established population revealed a broad age distribution and a 1:1 gender ratio, while fish from a recently invaded site were primarily of intermediate ages with a male-biased gender ratio. Otolith analyses suggested that the oldest individuals from the recently invaded area experienced superior growth...

  19. Consequences of eye fluke infection on anti-predator behaviours in invasive round gobies in Kalmar Sound

    DEFF Research Database (Denmark)

    Flink, Henrik; Behrens, Jane W.; Svensson, P. Andreas

    2017-01-01

    Larvae of the eye fluke, Diplostomum, emerge from snails and infect fish by penetrating skin or gills, then move to the lens where they may impair the vision of the fish. For the fluke to reproduce, a bird must eat the infected fish, and it has been suggested that they therefore actively manipulate...

  20. Evolutionary Novelty versus Exaptation: Oral Kinematics in Feeding versus Climbing in the Waterfall-Climbing Hawaiian Goby Sicyopterus stimpsoni

    Science.gov (United States)

    Cullen, Joshua A.; Maie, Takashi; Schoenfuss, Heiko L.; Blob, Richard W.

    2013-01-01

    Species exposed to extreme environments often exhibit distinctive traits that help meet the demands of such habitats. Such traits could evolve independently, but under intense selective pressures of extreme environments some existing structures or behaviors might be coopted to meet specialized demands, evolving via the process of exaptation. We evaluated the potential for exaptation to have operated in the evolution of novel behaviors of the waterfall-climbing gobiid fish genus Sicyopterus. These fish use an “inching” behavior to climb waterfalls, in which an oral sucker is cyclically protruded and attached to the climbing surface. They also exhibit a distinctive feeding behavior, in which the premaxilla is cyclically protruded to scrape diatoms from the substrate. Given the similarity of these patterns, we hypothesized that one might have been coopted from the other. To evaluate this, we filmed climbing and feeding in Sicyopterus stimpsoni from Hawai’i, and measured oral kinematics for two comparisons. First, we compared feeding kinematics of S. stimpsoni with those for two suction feeding gobiids (Awaous guamensis and Lentipes concolor), assessing what novel jaw movements were required for algal grazing. Second, we quantified the similarity of oral kinematics between feeding and climbing in S. stimpsoni, evaluating the potential for either to represent an exaptation from the other. Premaxillary movements showed the greatest differences between scraping and suction feeding taxa. Between feeding and climbing, overall profiles of oral kinematics matched closely for most variables in S. stimpsoni, with only a few showing significant differences in maximum values. Although current data cannot resolve whether oral movements for climbing were coopted from feeding, or feeding movements coopted from climbing, similarities between feeding and climbing kinematics in S. stimpsoni are consistent with evidence of exaptation, with modifications, between these behaviors. Such comparisons can provide insight into the evolutionary mechanisms facilitating exploitation of extreme habitats. PMID:23308184

  1. Modifications to the bottomless lift net for sampling nekton in tidal mangrove forests

    Science.gov (United States)

    McIvor, C.C.; Silverman, N.L.

    2010-01-01

    Sampling fishes in vegetated intertidal wetlands is logistically challenging. We modified the 2 ?? 3-m2 bottomless lift net developed for sampling nekton (fish and decapod crustaceans) on the surface of salt marshes for use in tidal mangrove forests with a woody (as opposed to herbaceous) underground root system. As originally designed (Rozas, Mar Ecol Prog Ser 89:287-292, 1992), the lift net was buried directly in the marsh substrate. The net was raised at slack high tide thereby encircling nekton within the enclosed area. A chain-line on the net bottom prevented escape under the net once deployed. However, when we used this same design in tidal mangrove forests, the extensive woody roots and occasional slumping sediments resulted in uneven trenches that could not be cleared effectively during sample recovery. We made 3 modifications to the original net design: (i) lined the peat trenches with aluminum channels of uniform width and depth; (ii) replaced the previous chain-line with Velcro closures that directly attached the net to the inner face of the outer wall of the aluminum channel; and (iii) removed the subtidal pan previously used for concentrating the enclosed nekton at low tide, and filled in those depressions with on-site peat. In the modified version, the aluminum trench became the only subtidal refuge available to nekton, and it was from here that we collected the sample after the forest drained. These modifications permitted high clearing efficiency (93-100%) of fin-clipped individuals of two common species of estuarine resident fishes, Kryptolebias marmoratus (mangrove rivulus) and Bathygobius soporator (frillfin goby). Additionally, the density estimates of grass shrimp (Palaemonetes spp.) increased 10-fold post-modification. ?? 2010 US Government.

  2. Dicty_cDB: VHA227 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available um chromoso... 33 7.5 AY698035_1( AY698035 |pid:none) Desmognathus marmoratus isolate 69... 33 7.5 AY612348_...1( AY612348 |pid:none) Desmognathus quadramaculatus vouch... 33 9.9 AY698038_1( AY698038 |pid:none) Desmogna...thus marmoratus isolate T0... 33 9.9 AY612344_1( AY612344 |pid:none) Desmognathus... marmoratus voucher KH... 33 9.9 AY698041_1( AY698041 |pid:none) Desmognathus marmoratus isolate T0... 33 9.

  3. Arterial pH and Blood Lactate Levels of Anesthetized Mongolian Khulan ( Equus hemionus hemionus) in the Mongolian Gobi Correlate with Induction Time.

    Science.gov (United States)

    Gerritsmann, Hanno; Stalder, Gabrielle L; Kaczensky, Petra; Buuveibaatar, Bayarbaatar; Payne, John; Boldbaatar, Sukhbaatar; Walzer, Chris

    2016-07-01

    Research and conservation of wide-ranging wild equids in most cases necessitate capture and handling of individuals. For free-roaming Mongolian khulan ( Equus hemionus hemionus), also known as the khulan, capture involves a strenuous, high-speed chase, and physiologic responses have yet to be elucidated. We analyzed sequential arterial blood gas (ABG) samples as a proxy for respiratory and metabolic status of khulan during capture-related anesthesia. We recorded precise chase and induction times and monitored vital parameters and ABG from free-ranging khulan during anesthesia performed for GPS collaring. At the initiation of anesthesia, animals had ABG values similar to those recorded for thoroughbred horses ( Equus caballus ) after maximal exercise. Longer induction times resulted in higher arterial pH (PpH and lactate was the time that elapsed between cessation of the chase and obtaining the first ABG sample, which, under field conditions, is tightly linked to induction time. All animals recovered uneventfully. Our data show that khulan recover and shift their metabolic status back toward expected normal values during opioid-based field anesthesia.

  4. Control of geomorphic processes on Be-10 concentrations in individual clasts : complexity of the exposure history in Gobi-Altay range (Mongolia)

    OpenAIRE

    Vassallo, R.; Ritz, J. F.; Carretier, Sébastien

    2011-01-01

    The dating of alluvial landforms by cosmogenic nuclides requires distinguishing the pre-deposition inheritance from the post-deposition history of the clasts in the studied marker. Moreover, estimating catchment-scale erosion rates from the concentrations of cosmogenic nuclides in active alluvia requires a good knowledge of the local/regional relationships between rock exhumation and transport through space and time. This is still poorly known for timescales of tens of thousand years. In orde...

  5. Seasonal diet pattern of non-native tubenose goby (Proterorhinus semilunaris) in the lowland reservoir (Mušov, Czech Republic)

    Czech Academy of Sciences Publication Activity Database

    Adámek, Z.; Jurajda, Pavel; Prášek, Václav; Sukop, I.

    2010-01-01

    Roč. 397, 02 (2010), s. 1-12 ISSN 1961-9502 R&D Projects: GA MŠk LC522 Institutional research plan: CEZ:AV0Z60930519 Keywords : Gobiidae * food * lowland reservoir * rip-rap bank * the Dyje River Subject RIV: EG - Zoology Impact factor: 0.304, year: 2010

  6. The Lost South Gobi Microcontinent: Protolith Studies of Metamorphic Tectonites and Implications for the Evolution of Continental Crust in Southeastern Mongolia

    Directory of Open Access Journals (Sweden)

    Matthew J. Heumann

    2013-08-01

    Full Text Available The Central Asian Orogenic Belt, or Altaids, is an amalgamation of volcanic arcs and microcontinent blocks that records a complex late Precambrian–Mesozoic accretionary history. Although microcontinents cored by Precambrian basement are proposed to play an integral role in the accretion process, a lack of isotopic data hampers volume estimates of newly produced arc-derived versus old-cratonic crust in southeastern Mongolia. This study investigates metamorphic tectonites in southern Mongolia that have been mapped as Precambrian in age, largely on the basis of their high metamorphic grade and high strain. Here we present results from microstructural analyses and U-Pb zircon geochronology on samples from Tavan Har (44.05° N, 109.55° E and the Yagan-Onch Hayrhan metamorphic core complex (41.89° N, 104.24° E. Our results show no compelling evidence for Precambrian basement in southeastern Mongolia. Rather, the protoliths to all tectonites examined are Paleozoic–Mesozoic age rocks, formed during Devonian–Carboniferous arc magmatism and subsequent Permian–Triassic orogenesis during collision of the South Mongolia arc with the northern margin of China. These results yield important insights into the Paleozoic accretionary history of southern Mongolia, including the genesis of metamorphic and igneous basement during the Paleozoic, as well as implications for subsequent intracontinental reactivation.

  7. Stairway to heaven: evaluating levels of biological organization correlated with the successful ascent of natural waterfalls in the Hawaiian stream goby Sicyopterus stimpsoni.

    Directory of Open Access Journals (Sweden)

    Heiko L Schoenfuss

    Full Text Available Selective pressures generated by locomotor challenges act at the level of the individual. However, phenotypic variation among individuals that might convey a selective advantage may occur across any of multiple levels of biological organization. In this study, we test for differences in external morphology, muscle mechanical advantage, muscle fiber type and protein expression among individuals of the waterfall climbing Hawaiian fish Sicyopterus stimpsoni collected from sequential pools increasing in elevation within a single freshwater stream. Despite predictions from previous laboratory studies of morphological selection, few directional morphometric changes in body shape were observed at successively higher elevations. Similarly, lever arm ratios associated with the main pelvic sucker, central to climbing ability in this species, did not differ between elevations. However, among climbing muscles, the adductor pelvicus complex (largely responsible for generating pelvic suction during climbing contained a significantly greater red muscle fiber content at upstream sites. A proteomic analysis of the adductor pelvicus revealed two-fold increases in expression levels for two respiratory chain proteins (NADH:ubiquinone reductase and cytochrome b that are essential for aerobic respiration among individuals from successively higher elevations. Assessed collectively, these evaluations reveal phenotypic differences at some, but not all levels of biological organization that are likely the result of selective pressures experienced during climbing.

  8. Dentirumai philippinensis n. gen., n. sp (Nematoda: Philometridae), a new tissue-infecting philometrid nematode from the loach goby Rhyacichthys aspro (Valenciennes) (Rhyacichthyidae) in the Philippines

    Czech Academy of Sciences Publication Activity Database

    Quiazon, K.M.A.; Moravec, František

    2013-01-01

    Roč. 87, č. 1 (2013), s. 59-65 ISSN 0022-149X R&D Projects: GA MŠk LC522 Institutional support: RVO:60077344 Keywords : Philometridae * Phillipine Archipelago * Parasitic nematode Subject RIV: EA - Cell Biology Impact factor: 1.303, year: 2013

  9. Stairway to Heaven: Evaluating Levels of Biological Organization Correlated with the Successful Ascent of Natural Waterfalls in the Hawaiian Stream Goby Sicyopterus stimpsoni

    Science.gov (United States)

    Schoenfuss, Heiko L.; Maie, Takashi; Moody, Kristine N.; Lesteberg, Kelsey E.; Blob, Richard W.; Schoenfuss, Tonya C.

    2013-01-01

    Selective pressures generated by locomotor challenges act at the level of the individual. However, phenotypic variation among individuals that might convey a selective advantage may occur across any of multiple levels of biological organization. In this study, we test for differences in external morphology, muscle mechanical advantage, muscle fiber type and protein expression among individuals of the waterfall climbing Hawaiian fish Sicyopterus stimpsoni collected from sequential pools increasing in elevation within a single freshwater stream. Despite predictions from previous laboratory studies of morphological selection, few directional morphometric changes in body shape were observed at successively higher elevations. Similarly, lever arm ratios associated with the main pelvic sucker, central to climbing ability in this species, did not differ between elevations. However, among climbing muscles, the adductor pelvicus complex (largely responsible for generating pelvic suction during climbing) contained a significantly greater red muscle fiber content at upstream sites. A proteomic analysis of the adductor pelvicus revealed two-fold increases in expression levels for two respiratory chain proteins (NADH:ubiquinone reductase and cytochrome b) that are essential for aerobic respiration among individuals from successively higher elevations. Assessed collectively, these evaluations reveal phenotypic differences at some, but not all levels of biological organization that are likely the result of selective pressures experienced during climbing. PMID:24386424

  10. Dicty_cDB: VHK596 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available 34 4.7 AY698035_1( AY698035 |pid:none) Desmognathus marmoratus isolate 69... 33 6.1 AC116957_68( AC116957 |p...id:none) Dictyostelium discoideum chromoso... 33 8.0 AY612344_1( AY612344 |pid:none) Desmognathus marmoratus

  11. Dicty_cDB: VHA340 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available _1( AY698035 |pid:none) Desmognathus marmoratus isolate 69... 33 5.9 AC116957_68( AC116957 |pid:none) Dictyo...stelium discoideum chromoso... 33 7.6 AY612344_1( AY612344 |pid:none) Desmognathus marmoratus voucher KH...

  12. Dicty_cDB: VHC580 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available stridium thermocellum ATCC 2... 34 4.8 AY698035_1( AY698035 |pid:none) Desmognathus marmoratus isolate 69...... 33 6.2 AY612344_1( AY612344 |pid:none) Desmognathus marmoratus voucher KH... 33 8.2 AC116957_68( AC116957 |

  13. A Comprehensive Modeling Approach Towards Understanding and Prediction of the Alaskan Coastal System Response to Changes in an Ice-diminished Arctic

    Science.gov (United States)

    2008-01-01

    led to reduced ice cover in the Arctic, increased water temperatures, and perhaps increased desertification of adjacent lands, i.e. the Gobi desert...North Pacific Ocean, after deposition episodes of iron- rich dust from the Gobi Desert. During NASA satellite imagery of an eastward propagation of Gobi ...underneath aerosol plumes of iron-rich dust from the Gobi Desert. During this same time period, the areal extent of summer Arctic sea ice cover had

  14. Characteristics of the ichthyofauna of a temperate microtidal estuary with a reverse salinity gradient, including inter-decadal comparisons.

    Science.gov (United States)

    Veale, L; Tweedley, J R; Clarke, K R; Hallett, C S; Potter, I C

    2014-11-01

    apex region, in which salinities reached 54 and temperatures 36° C, recorded the highest maximum density and, in terms of abundance, was dominated (90%) by three atherinid species, emphasizing the ability of this family to tolerate extreme conditions. Comparisons between the data for 2008-2010 and 1994 demonstrate that the spotted hardyhead Craterocephalus mugiloides and the common hardyhead Atherinomorus vaigiensis had colonized and become abundant in the Leschenault Estuary in the intervening period. This represents a southwards extension of the distribution of these essentially tropical species during a period of increasing coastal water temperatures as a result of climate change. The abundance of weed-associated species, e.g. the western gobbleguts Ostorhinchus rueppellii and the soldier Gymnapistes marmoratus, increased, whereas that of the longfinned goby Favonigobius lateralis decreased, probably reflecting increases in eutrophication and siltation, respectively. © 2014 The Fisheries Society of the British Isles.

  15. Dicty_cDB: VHL427 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available d:none) Dictyostelium discoideum chromoso... 33 7.5 AY698035_1( AY698035 |pid:none) Desmognathus marmoratus ...isolate 69... 33 7.5 AY612348_1( AY612348 |pid:none) Desmognathus quadramaculatus vouch... 33 9.8 AY698038_1...( AY698038 |pid:none) Desmognathus marmoratus isolate T0... 33 9.8 AY612344_1( AY612344 |pid:none) Desmog...nathus marmoratus voucher KH... 33 9.8 AY698041_1( AY698041 |pid:none) Desmognathus

  16. Enige metingen over het standaard metabolisme en het actief metabolisme bij Gobiidae

    NARCIS (Netherlands)

    Penning de Vries, F.W.T.

    1969-01-01

    An attempt was made to determine the "scope for activity" -maximal active metabolism minus basal metabolism and its relation to temperature in the three species Pomatoschistus minutus,P.lozanoi and P. microps, in order to find a possible explanation for the difference in their

  17. Invloed van temperatuur en zoutgehalte op de ontwikkeling van eieren van enkele soorten zeegrondels

    NARCIS (Netherlands)

    van Buurt, G.

    1974-01-01

    Eggs of closely related estuarine and neritic Pomatoschistus species were incubated at 24 different temperature-salinity combinations (ranges 10 to 25°C, 5 to 55 per thousand S). Rate of development, survival and larval length at hatch were recorded in relation to incubation conditions.

  18. Non-homologous sex chromosomes in two geckos (Gekkonidae: Gekkota) with female heterogamety.

    Science.gov (United States)

    Matsubara, Kazumi; Gamble, Tony; Matsuda, Yoichi; Zarkower, David; Sarre, Stephen D; Georges, Arthur; Graves, Jennifer A Marshall; Ezaz, Tariq

    2014-01-01

    Evaluating homology between the sex chromosomes of different species is an important first step in deducing the origins and evolution of sex-determining mechanisms in a clade. Here, we describe the preparation of Z and W chromosome paints via chromosome microdissection from the Australian marbled gecko (Christinus marmoratus) and their subsequent use in evaluating sex chromosome homology with the ZW chromosomes of the Kwangsi gecko (Gekko hokouensis) from eastern Asia. We show that the ZW sex chromosomes of C. marmoratus and G. hokouensis are not homologous and represent independent origins of female heterogamety within the Gekkonidae. We also show that the C. marmoratus Z and W chromosomes are genetically similar to each other as revealed by C-banding, comparative genomic hybridization, and the reciprocal painting of Z and W chromosome probes. This implies that sex chromosomes in C. marmoratus are at an early stage of differentiation, suggesting a recent origin. © 2014 S. Karger AG, Basel.

  19. Dicty_cDB: VHI137 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available alignments: (bits) Value AY698035_1( AY698035 |pid:none) Desmognathus marmoratus isolate 69... 40 0.067 AY6...12344_1( AY612344 |pid:none) Desmognathus marmoratus voucher KH... 40 0.088 DQ018662_1( DQ018662 |pid:none) ...Plethodon dunni isolate 75356 NADH... 37 0.57 AY612348_1( AY612348 |pid:none) Desmog...nathus quadramaculatus vouch... 36 1.3 AY698038_1( AY698038 |pid:none) Desmognathus marmoratus isolate T0...... 36 1.3 AY698041_1( AY698041 |pid:none) Desmognathus marmoratus isolate T0... 36 1.3 CP000270_2676( CP000

  20. Dicty_cDB: VHP481 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available g significant alignments: (bits) Value AY698035_1( AY698035 |pid:none) Desmognath...us marmoratus isolate 69... 40 0.060 AY612344_1( AY612344 |pid:none) Desmognathus marmoratus voucher KH... 4...0 0.079 DQ018662_1( DQ018662 |pid:none) Plethodon dunni isolate 75356 NADH... 38 0.30 AY612348_1( AY612348 |pid:none) Desmog...nathus quadramaculatus vouch... 36 1.1 AY698038_1( AY698038 |pid:none) Desmog...nathus marmoratus isolate T0... 36 1.1 AY698041_1( AY698041 |pid:none) Desmognathus marmoratus i

  1. Dicty_cDB: VHN394 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available ents: (bits) Value AY698035_1( AY698035 |pid:none) Desmognathus marmoratus isolate 69... 40 0.067 AY612344_1...on dunni isolate 75356 NADH... 37 0.57 AY612348_1( AY612348 |pid:none) Desmognath...us quadramaculatus vouch... 36 1.3 AY698038_1( AY698038 |pid:none) Desmognathus marmoratus isolate T0... 36 ...1.3 AY698041_1( AY698041 |pid:none) Desmognathus marmoratus isolate T0... 36 1.3 CP000270_2676( CP000270 |pi...( AY612344 |pid:none) Desmognathus marmoratus voucher KH... 40 0.087 DQ018662_1( DQ018662 |pid:none) Plethod

  2. Genetic and growth differences in the outcrossings between two clonal strains of the self-fertilizing mangrove killifish

    OpenAIRE

    Nakamura, Yukino; Suga, Koushirou; Sakakura, Yoshitaka; Sakamoto, Takashi; Hagiwara, Atsushi

    2008-01-01

    The populations of the only known self-fertilizing vertebrate Kryptolebias marmoratus (Poey, 1880) (formerly known as Rivulus marmoratus Poey, 1880; Cyprinodontiformes: Aplocheilidae) usually consist of different homozygous lineages; however, heterozygous individuals are found occasionally and ratios of homozygosity and heterozygosity in populations are dependent on the proportion of males. However, it is still unclear what impact male-mediated genetic diversity has on the phenotype of K. mar...

  3. Impact of Gobi desert dust on aerosol chemistry of Xi'an, inland China during spring 2009: differences in composition and size distribution between the urban ground surface and the mountain atmosphere

    OpenAIRE

    G. H. Wang; B. H. Zhou; C. L. Cheng; J. J. Cao; J. J. Li; J. J. Meng; J. Tao; R. J. Zhang; P. Q. Fu

    2013-01-01

    Composition and size distribution of atmospheric aerosols from Xi'an city (~400 m, altitude) in inland China during the spring of 2009 including a massive dust event on 24 April were measured and compared with a parallel measurement at the summit (2060 m, altitude) of Mt. Hua, an alpine site nearby Xi'an. EC (elemental carbon), OC (organic carbon) and major ions in the city were 2–22 times higher than those on the mountaintop during the whole sampling period. Compared to that in the non-dust ...

  4. Diet composition and food consumption rate of harbor porpoises (Phocoena phocoena ) in the western Baltic Sea

    DEFF Research Database (Denmark)

    Andreasen, Heidi; Ross, Stine Dalmann; Siebert, Ursula

    2017-01-01

    frequently consumed gobies. Here, the mass contribution by gobies was on aver-age 25%, which was as much as cod. Other species such as whiting, sprat, eelpout, and sandeels were of minor importance for both juveniles and adults. The diet compo- sition differed between years, quarters, and porpoise...

  5. Dicty_cDB: Contig-U12390-1 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available .......................done Score E Sequences producing significant alignments: (bits) Value AY698035_1( AY698035 |pid:none) Desmog...nathus marmoratus isolate 69... 40 0.18 AY612344_1( AY612344 |pid:none) Desmog...isolate 75356 NADH... 38 0.92 AY612348_1( AY612348 |pid:none) Desmognathus quadramaculatus vouch... 36 3.5 A...Y698038_1( AY698038 |pid:none) Desmognathus marmoratus isolate T0... 36 3.5 AY698...041_1( AY698041 |pid:none) Desmognathus marmoratus isolate T0... 36 3.5 CP000270_2676( CP000270 |pid:none) B

  6. Invasion strategy and abiotic activity triggers for non-native gobiids of the River Rhine.

    Directory of Open Access Journals (Sweden)

    Jan Baer

    Full Text Available The 24 hour activity patterns of three non-native gobiids (round goby Neogobius melanostomus, Western tubenose goby Proterorhinus semilunaris and bighead goby Ponticola kessleri were assessed over 46 consecutive months between 2011 and 2014 from their occurrence in the cooling water intake of a nuclear power plant on the River Rhine, Germany. In total, 117717 gobiids were identified and classified. The occurrence of all three species varied strongly between sampling years, and species-specific activity triggers were identified. The activity of juveniles of all three gobiids species was positively temperature dependent while adult tubenose goby activity appeared to be negatively temperature dependent. Increasing fluvial discharge in the adjoining main river stimulated the activity of juvenile round goby but inhibited activity of adult tubenose goby. Except for adult bighead goby, activity was also structured by time of day, but with no uniform mean. Meteorological factors such as precipitation, air pressure and duration of sunshine hours had little or no influence on gobiid activity. On selected rare occasions, mainly at night, all three species exhibited pulsed swarming behaviour, with thousands of individuals recorded in the intake water. Round goby swarms exhibited both the highest intensity and the largest swarming individuals, suggesting a potential competitive advantage over tubenose and bighead goby. Electric fishing surveys in natural river stretches corroborated this observation. Negative effects on the native fish fauna were apparent only for the bullhead, Cottus gobio. The activity triggers identified offer a unique insight into the invasion mechanisms of these ecosystem-changing non-native gobiids.

  7. Trophic structure and community stability in an overfished ecosystem

    KAUST Repository

    Utne-Palm, Anne Christine

    2010-07-15

    Since the collapse of the pelagic fisheries off southwest Africa in the late 1960s, jellyfish biomass has increased and the structure of the Benguelan fish community has shifted, making the bearded goby (Sufflogobius bibarbatus) the new predominant prey species. Despite increased prédation pressure and a harsh environment, the gobies are thriving. Here we show that physiological adaptations and antipredator and foraging behaviors underpin the success of these fish. In particular, body-tissue isotope signatures reveal that gobies consume jellyfish and sulphidic diatomaceous mud, transferring "dead-end" resources back into the food chain.

  8. The Effect of Microclimates in the Aeolian Sand Environment at the Mogao Grottoes, China

    Directory of Open Access Journals (Sweden)

    Guo Shuai Li

    2013-01-01

    Full Text Available To study the micro-meteorological effects of different underlying surfaces of structures to protect the Mogao Grottoes, we analyzed basic meteorological measurements collected at weather stations located in front of the grottoes, on top of the grottoes and in the artificial Gobi. The results show that the shelterbelts in front of the grottoes have a heat-retaining effect. The profile of average daily solar radiation in front of the grottoes forms a sharp peak and the profile in the Gobi forms a parabola, but these patterns vary in different seasons. The artificial Gobi was more susceptible to extremes in temperature and had a faster response and wider response range to ground temperature. The average monthly air temperature, average monthly relative humidity, and the average wind speed in the artificial Gobi tend to first decrease and then increase with measurement height.

  9. Isolation and characterization of biogenic calcium carbonate ...

    Indian Academy of Sciences (India)

    Author Affiliations. GOBI SARAVANAN KALIARAJ1 KAMALAN KIRUBAHARAN1 G PRADHABAN1 P KUPPUSAMI1 VINITA VISHWAKARMA1. Centre for Nanoscience and Nanotechnology, Sathyabama University, Chennai 600119, India ...

  10. Novelty versus environment: two viewpoints on the same phenomenon?

    Czech Academy of Sciences Publication Activity Database

    Janáč, Michal; Konečná, Markéta; Roche, Kevin Francis; Jurajda, Pavel

    2016-01-01

    Roč. 25, č. 4 (2016), s. 678-681 ISSN 0906-6691 Institutional support: RVO:68081766 Keywords : Neogobius melanostomus * Round goby * formalin Subject RIV: EG - Zoology Impact factor: 2.054, year: 2016

  11. Integrative taxonomy and phylogeny-based species delimitation of Philippine water monitor lizards (Varanus salvator Complex) with descriptions of two new cryptic species.

    Science.gov (United States)

    Welton, Luke J; Travers, Scott L; Siler, Cameron D; Brown, Rafe M

    2014-11-05

    We describe two new species of morphologically cryptic monitor lizards (genus Varanus) from the Philippine Archipelago:  Varanus dalubhasa sp. nov. and V. bangonorum sp. nov. These two distinct evolutionary lineages are members of the V. salvator species complex, and historically have been considered conspecific with the widespread, northern Philippine V. marmoratus. However, the new species each share closer phylogenetic affinities with V. nuchalis (and potentially V. palawanensis), than either does to one another or to V. marmoratus. Divergent from other recognized species within the V. salvator Complex of water monitors by as much as 3.5% pairwise genetic distance, these lineages are also distinguished by unique gular coloration, metrics of body size and scalation, their non-monophyly with "true" V. marmoratus, and insular allopatric distributions, suggesting biogeographically distinct and unique evolutionary histories. We compare the new species with the most geographically proximate and phenotypically relevant lineages.  Although we show that these new taxa are nearly indistinguishable morphologically from V. marmoratus, both species can be readily distinguished from their closest relatives (each's respective sister taxon, V. palawanensis and V. nuchalis) by traditional morphological characters.  Our findings underscore the high herpetological diversity and biogeographical complexity of vertebrates in the Philippines, and further emphasize the need for detailed study of species-level diversity, mechanisms of reproductive isolation, gene flow, and biologically relevant boundaries between taxa within the V. salvator Complex.

  12. 78 FR 22278 - Proposed Amendment of Habitat Conservation Plan and Associated Documents; Green Diamond Resource...

    Science.gov (United States)

    2013-04-15

    ... (Brachyramphus marmoratus) habitat protection; and the IA would be amended to include a new clause and a new... murrelet habitat map, and the addition of a severability and savings clause. Anticipated Effects of... categorical exclusion under NEPA as provided by the Department of the Interior Manual (516 DM 2 Appendix 2 and...

  13. Chapter 22: Marbled Murrelet Food Habits and Prey Ecology

    Science.gov (United States)

    Esther E. Burkett

    1995-01-01

    Information on food habits of the Marbled Murrelet (Brachyramphus marmoratus) was compiled from systematic studies and anecdotal reports from Alaska to California. Major differences between the winter and summer diets were apparent, with euphausiids and mysids becoming more dominant during winter and spring. The primary invertebrate prey items were...

  14. A preliminary biochemical genetic survey of four South African ...

    African Journals Online (AJOL)

    Allozyme electrophoresis was used to evaluate genetic variability in painted reed frog (Hyperolius marmoratus) populations from the Northern Province and the Eastern Cape. Sixteen protein-encoding loci were resolved, of which seven displayed allelic polymorphism. Average heterozygosity (H) values in two permanent H.

  15. Logistic regression accuracy across different spatial and temporal scales for a wide-ranging species, the marbled murrelet

    Science.gov (United States)

    Carolyn B. Meyer; Sherri L. Miller; C. John Ralph

    2004-01-01

    The scale at which habitat variables are measured affects the accuracy of resource selection functions in predicting animal use of sites. We used logistic regression models for a wide-ranging species, the marbled murrelet, (Brachyramphus marmoratus) in a large region in California to address how much changing the spatial or temporal scale of...

  16. Characterization of nine new microsatellite loci for the marbled newt ...

    Indian Academy of Sciences (India)

    Triturus marmoratus is distributed throughout central, west- ern and southern France as well as in a large portion of north- ern Iberia. Despite being categorized as of least concern by the IUCN, it is protected by the Annex IV of the EU Habitats. Directive and the Annex III of the Bern Convention (Arntzen et al. 2009). As most ...

  17. Regional population monitoring of the marbled murrelet: field and analytical methods.

    Science.gov (United States)

    Martin G. Raphael; Jim Baldwin; Gary A. Falxa; Mark H. Huff; Monique Lance; Sherri L. Miller; Scott F. Pearson; C. John Ralph; Craig Strong; Chris. Thompson

    2007-01-01

    The marbled murrelet (Brachyramphus marmoratus) ranges from Alaska to California and is listed under the Endangered Species Act as a threatened species in Washington, Oregon, and California. Marbled murrelet recovery depends, in large part, on conservation and restoration of breeding habitat on federally managed lands. A major objective of the...

  18. Northwest Forest Plan—the first 10 years (1994-2003): status and trends of populations and nesting habitat for the marbled murrelet.

    Science.gov (United States)

    Mark H. Huff; Martin G. Raphael; Sherri L. Miller; S. Kim Nelson; Jim Baldwin

    2006-01-01

    The Northwest Forest Plan (the Plan) is a large-scale ecosystem management plan for federal land in the Pacific Northwest. Marbled murrelet (Brachyramphus marmoratus) populations and habitat were monitored to evaluate effectiveness of the Plan. The chapters in this volume summarize information on marbled murrelet ecology and present the monitoring...

  19. Colour patterning in the skin of the reed-frog

    African Journals Online (AJOL)

    1985-12-08

    Dec 8, 1985 ... A collec1ion 01 37 Natal reed·frogs, HyperoJius marmoratus, from a single locality was studied for their dorsal colour pattems. Data were assembled on the spectrophotometry, the structure and distribution of ttie chromato· phores by means of light and electron microscopy, and the features of colour ...

  20. The structure of the nasal chemosensory system in squamate ...

    Indian Academy of Sciences (India)

    This study examined the extent and morphology of the main olfactory organ in several Australian squamate reptiles, including three species of gekkotans, two species of skinks and one snake species. The olfactory mucosa of two gekkotan species (Christinus marmoratus and Strophurus intermedius) is spread over a large ...

  1. Chapter 36: Status of Forest Habitat of the Marbled Murrelet

    Science.gov (United States)

    David A. Perry

    1995-01-01

    Marbled Murrelets (Brachyramphus marmoratus) have been shown to be dependant upon old-growth forests for nesting habitat. These forests have declined over the last century as they are cut for human use. This paper reviews the current status of old-growth forests along the west coast, in both the United States and Canada.

  2. Dicty_cDB: VHF408 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available MTYF9_FA... 33 7.5 CP000568_3082( CP000568 |pid:none) Clostridium thermocellum ATCC 2... 33 9.8 AY698035_1(... AY698035 |pid:none) Desmognathus marmoratus isolate 69... 33 9.8 protein update 2009. 3. 3 PSORT psg: 0.69

  3. Dicty_cDB: VHH521 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available d:none) Clostridium thermocellum ATCC 2... 34 4.9 AY698035_1( AY698035 |pid:none) Desmog...moso... 33 8.4 AY612344_1( AY612344 |pid:none) Desmognathus marmoratus voucher KH... 33 8.4 protein update 2

  4. Competition in three Cyprinodont fish species in the Netherlands Antilles

    NARCIS (Netherlands)

    Kristensen, Ingvar

    1970-01-01

    Cyprinodon dearborni, Poecilia sphenops and Rivulus marmoratus seem to fill almost the same niche. In most of the landlocked bays, lagoons or pools the three species were not found together. In only two landlocked locations two of the species were found together. In the locations with an open

  5. Meeting reproductive demands in a dynamic upwelling system: foraging strategies of a pursuit-diving seabird, the marbled murrelet

    Science.gov (United States)

    M. Zachariah Peery; Scott H. Newman; Curt D. Storlazzi; Steven R. Beissinger

    2009-01-01

    Seabirds maintain plasticity in their foraging behavior to cope with energy demands and foraging constraints that vary over the reproductive cycle, but behavioral studies comparing breeding and nonbreeding individuals are rare. Here we characterize how Marbled Murrelets (Brachyramphus marmoratus) adjust their foraging effort in response to changes...

  6. A Numerical Modeling Study on Desert Oasis Self-Supporting Mechanisms

    Science.gov (United States)

    2005-01-01

    soil, and biological resources have led to drought, salinization, and desertification and conse- quently have hindered the development of sustainable...water vapor flux is downward over the Gobi desert (Wang and Mitsuta, 1992). As part of HEIFE, the fundamental observational period observations were...NW–SE) by 25 km (NE–SW), and is surrounded by sandy and Gobi deserts. Small sensible heat-flux and dominating latent heat-flux in the surface energy

  7. JPRS Report, Science & Technology. China.

    Science.gov (United States)

    1989-03-29

    Waste Sites Planned for Zhejiang, Northwest [Seth Faison; SOUTH CHINA MORNING POST, 20 Feb 89] 78 Briefs Antarctic Facility Beefed Up 80 Gobi ...forests and grasslands, soil and water loss, soil salinization and desertification , and if we do not reverse the rapid loss of rare and endangered...Uygur autonomous region in the far northwest, an area mainly made up of uninhabited desert and mountains. The northwest’s Gobi Desert has been

  8. Gut content analysis of Lake Michigan waterbirds in years with avian botulism type E mortality, 2010–2012

    Science.gov (United States)

    Essian, David A.; Chipault, Jennifer G.; Lafrancois, Brenda M.; Leonard, Jill B.K.

    2016-01-01

    Waterbird die-offs caused by Clostridium botulinum neurotoxin type E (BoNT/E) have occurred sporadically in the Great Lakes since the late 1960s, with a recent pulse starting in the late 1990s. In recent die-offs, round gobies (Neogobius melanostomus) have been implicated as vectors for the transfer of BoNT/E to fish-eating birds due to the round goby invasion history and their importance as prey. Dreissenid mussels (Dreissena spp.) are also potentially involved in BoNT/E transmission to birds and round gobies. We examined gut contents of waterbirds collected in Lake Michigan during die-offs in 2010–2012, and the gut contents of culled, presumably BoNT/E-free double-crested cormorants (Phalacrocorax auritus). Round gobies were found in 86% of the BoNT/E-positive individuals, 84% of the BoNT/E-negative birds, and 94% of the BoNT/E-free cormorants examined. Double-crested cormorants, ring-billed gulls (Larus delewarensis), and common loons (Gavia immer) consumed larger-sized round gobies than horned and red-necked grebes (Podiceps auritus and Podiceps grisegena), white-winged scoters (Melanitta deglandi), and long-tailed ducks (Clangula hymealis). Other common prey included dreissenid mussels, terrestrial insects, and alewives (Alosa pseudoharengus). Our data emphasize the importance of round gobies and mussels in diets of Lake Michigan waterbirds and suggest they may play a role in the transfer of BoNT/E to waterbirds; however, round gobies and mussels were found in BoNT/E-positive, -negative, and -free individuals, suggesting that other factors, such as alternative trophic pathways for toxin transfer, bird migratory timing and feeding locations, prey behavior, and individual physiological differences across birds may affect the likelihood that a bird will succumb to BoNT/E intoxication.

  9. Correlation and Fishers’ Perception in Selected Sites in Laguna de Bay, Luzon Island, Philippines

    Directory of Open Access Journals (Sweden)

    Arthur J. Lagbas

    2017-01-01

    Full Text Available White goby (Glossogobius giuris Hamilton 1822 is an omnivorous, native fish species which can be found in Laguna de Bay and its tributaries, and in other bodies of water in the Philippines. Deteriorating water quality, unsustainable fishing practices, aquaculture and predation by introduced invasive species are threatening the population of white goby and other native fish species in Laguna de Bay. This study was conducted to correlate select physico-chemical parameters of lake water and zooplankton abundance, and to assess white goby population based on fishers’ perception. Water samples were collected in three sites in June, September and December 2014. Twenty one zooplankton species belonging to 12 families were identified. The most abundant and frequently encountered zooplankton species is Eurytemora affinis Poppe 1880. Zooplanktons were most abundant in June and lowest in September. Key informant interviews with local fishers revealed that white goby population was abundant in April to August while catch report showed that fish catch is abundant in June and least during December. The fish abundance in April to June could be attributed to high productivity especially in summer season. The fishers perceived that the population of white goby was declining mainly due to water pollution, aquaculture, and predation by invasive alien species. A multi-stakeholder sustainable watershed management should be adapted to improve the water quality and extinction of native fish species in Laguna de Bay.

  10. Otoliths as an integral part in fossil fish taxonomy

    Directory of Open Access Journals (Sweden)

    Christoph Gierl

    2015-11-01

    Full Text Available Otoliths are small structures in the skull of fishes. They are responsible for hearing and orientation in the 3-dimensional space. They also hold valuable information regarding the taxonomy. Their outline, the shape of the sulcus and other features allow the determination of a fish even to the species level. A lot of fossil species are solely based on otoliths because of their good chance of preservation. Gobies are in this case no different. An additional challenge in gobies is their high similarity between species concerning the preservable parts. Fossil skeletons that are 20 Million years old can show only few differences compared to recent gobies. These features are often hardly recognizable due to their preservation. As a consequence many fossil gobies have been assigned to the genus Gobius sensu lato. Examples are two gobies from the Miocene of Southern Germany. They have a unique combination of characters (six branchiostegals, palatine resembling a “T”, no entopterygoid that allows the rectification of a new fossil genus but the two species are hardly distinguishable based only on the skeleton. The key hints in having two species are the otoliths. They show slight but consistent differences in their outline. This shows that otoliths can be a key feature in species identification. They should also be taken into consideration by recent fish species. Not to mention their possible phylogenetic potential that remains to be explored.

  11. A Field Observation of Rotational Feeding by Neogobius melanostomus

    Directory of Open Access Journals (Sweden)

    Ted R. Angradi

    2018-01-01

    Full Text Available Neogobius melanostomus, the round goby, was recorded by underwater video feeding on crushed dreissenid mussels at a depth of 12 m in Georgian Bay of Lake Huron, a Laurentian Great Lake. In the video, gobies used rotational or twist feeding to tear away particles from crushed mussels. At least 43 examples of this feeding maneuver occur in the video. Up to 120 gobies m−2 were visible at a time in the video. Mean standard length of gobies appearing in the video was 37 mm. Mean standard length of fish exhibiting twist feeding was larger, 48 mm. Mean size of intact mussels in visible clusters was about 10 × 20 mm, a size which exceeds the gape width of the largest gobies observed in the video. Neogobius melanostomus is known to use twisting to wrest small attached mussels from the substrates which can be crushed by their pharyngeal teeth. I surmise that the behavior observed in the video is an opportunistic manifestation of this inherent behavioral adaptation to overcome gap limitation and exploit a temporary windfall of food.

  12. Estado de las poblaciones de anfibios en un parque urbano de Pamplona

    Directory of Open Access Journals (Sweden)

    Gosá, A., Arias, A.

    2009-01-01

    Full Text Available Las poblaciones aisladas de tres anfibios (Triturus marmoratus, Alytes obstetricans, Pelophylax perezi han sido muestreadas entre 2005 y 2007, en primavera y finales de verano, en un canal y tres estanques de un parque urbano céntrico de la ciudad de Pamplona. Los 8 adultos censados en 2005 de T. marmoratus han podido desaparecer en los años siguientes, a causa de unas obras urbanas realizadas junto al parque. La estima de la población de A. obstetricans se acerca al millar de adultos. Su periodo reproductor se extiende hasta septiembre, y una parte de la población larvaria inverna sin metamorfosear. El ajardinamiento de la zona, la contaminación del agua y la presencia de depredadores y competidores introducidos, como Procambarus clarkii y Carassius auratus, ponen en peligro la supervivencia de los anfibios.

  13. Extreme homogeneity and low genetic diversity in Kryptolebias ocellatus from south-eastern Brazil suggest a recent foundation for this androdioecious fish population.

    Science.gov (United States)

    Tatarenkov, A; Lima, S M Q; Avise, J C

    2011-12-01

    This study documents unexpectedly low levels of intra and interpopulation genetic diversity in Kryptolebias ocellatus, an androdioecious and predominantly self-fertilizing killifish from south-eastern Brazil. This finding generally is inconsistent with the established opinion that the K. ocellatus and K. marmoratus clade originated in this geographic region and later dispersed northward into the Caribbean. © 2011 The Authors. Journal of Fish Biology © 2011 The Fisheries Society of the British Isles.

  14. Comparative cytogenetics of Physalaemus albifrons and Physalaemus cuvieri species groups (Anura, Leptodactylidae)

    Science.gov (United States)

    Vittorazzi, Stenio Eder; Quinderé*, Yeda Rumi Serra Douglas; Recco-Pimentel, Shirlei Maria; Tomatis, Cristian; Baldo, Diego; Lima, Janaina Reis Ferreira; Ferro, Juan Martín; Lima, Jucivaldo Dias; Lourenço, Luciana Bolsoni

    2014-01-01

    Abstract Recently, Physalaemus albifrons (Spix, 1824) was relocated from the Physalaemus cuvieri group to the same group as Physalaemus biligonigerus (Cope, 1861), Physalaemus marmoratus (Reinhardt & Lütken, 1862) and Physalaemus santafecinus Barrio, 1965. To contribute to the analysis of this proposition, we studied the karyotypes of Physalaemus albifrons, Physalaemus santafecinus and three species of the Physalaemus cuvieri group. The karyotype of Physalaemus santafecinus was found to be very similar to those of Physalaemus biligonigerus and Physalaemus marmoratus, which were previously described. A remarkable characteristic that these three species share is a conspicuous C-band that extends from the pericentromeric region almost to the telomere in the short arm of chromosome 3. This characteristic is not present in the Physalaemus albifrons karyotype and could be a synapomorphy of Physalaemus biligonigerus, Physalaemus marmoratus and Physalaemus santafecinus. The karyotype of Physalaemus santafecinus is also similar to those of Physalaemus marmoratus and Physalaemus biligonigerus owing to the presence of several terminal C-bands and the distal localization of the NOR in a small metacentric chromosome. In contrast, the Physalaemus albifrons karyotype has no terminal C-bands and its NOR is located interstitially in the long arm of submetacentric chromosome 8. The NOR-bearing chromosome of Physalaemus albifrons very closely resembles those found in Physalaemus albonotatus (Steindachner, 1864), Physalaemus cuqui Lobo, 1993 and some populations of Physalaemus cuvieri Fitzinger, 1826. Additionally, the Physalaemus albifrons karyotype has an interstitial C-band in chromosome 5 that has been exclusively observed in species of the Physalaemus cuvieri group. Therefore, we were not able to identify any chromosomal feature that supports the reallocation of Physalaemus albifrons. PMID:25147623

  15. Evidence from cytochrome b sequences and allozymes for a new species of alcid: The long-billed murrelet (Brachyramphus perdix)

    Science.gov (United States)

    Friesen, Vicki L.; Piatt, John F.; Baker, Allan J.

    1996-01-01

    Marbled Murrelets (Brachyramphus marmoratus) are coastal seabirds that breed predominantly in old-growth forest throughout the North Pacific. Presently they are classified into two phenotypically distinct subspecies: one in North America (B. m. marmoratus) and one in Asia (B. m. perdix). The Asian form was classified as a separate species in 1811, but was lumped with B. marmoratus during the 20th century. Populations of both types are considered threatened or endangered and information about the extent of genetic differentiation among birds from different sites is required for their conservation. We compared variation in 1,045 base pairs of the mitochondrial cytochrome b gene and 39 allozyme loci among Marbled Murrelets and the closely related Kittlitz's Murrelets (B. brevirostris) from throughout the North Pacific. All analyses indicted that North American and Asian Marbled Murrelets are genetically distinct: cytochrome b sequences were highly divergent, fixed allele differences occurred at two allozyme loci, and estimated gene flow was essentially zero. Phylogenetic analyses of cytochrome b sequences and allozymes both provided strong support for a monophyletic relationship among North American Marbled Murrelets and Kittlitz's Murrelets, with Long-billed Murrelets forming the basal lineage. Long-billed and North American Marbled Murrelets clearly represent distinct species by any definition, and must be managed independently. Significant genetic differentiation also was found among both Marbled and Kittlitz's Murrelets from different sites within North America.

  16. Life cycle assessment and evaluation of energy payback time on high-concentration photovoltaic power generation system

    International Nuclear Information System (INIS)

    Nishimura, A.; Hayashi, Y.; Tanaka, K.; Hirota, M.; Kato, S.; Ito, M.; Araki, K.; Hu, E.J.

    2010-01-01

    In this study, the environmental load of photovoltaic power generation system (PV) during its life cycle and energy payback time (EPT) are evaluated by LCA scheme. Two hypothetical case studies in Toyohashi, Japan and Gobi dessert in China have been carried out to investigate the influence of installation location and PV type on environmental load and EPT. The environmental load and EPT of a high-concentration photovoltaic power generation system (hcpV) and a multi-crystalline silicon photovoltaic power generation system (mc-Si PV) are studied. The study shows for a PV of 100 MW size, the total impacts of the hcpV installed in Toyohashi is larger than that of the hcpV installed in Gobi desert by 5% without consideration of recycling stage. The EPT of the hcpV assumed to be installed in Gobi desert is shorter than EPT of the hcpV assumed to be installed in Toyohashi by 0.64 year. From these results, the superiority to install PV in Gobi desert is certificated. Comparing with hcpV and mc-Si PV, the ratio of the total impacts of mc-Si PV to that of hcpV is 0.34 without consideration of recycling stage. The EPT of hcpV is longer than EPT of mc-Si PV by 0.27 year. The amount of global solar radiation contributing to the amount of power generation of mc-Si PV is larger than the amount of direct solar radiation contributing to the amount of power generation of hcpV by about 188 kW h/(m 2 year) in Gobi desert. Consequently, it appears that using mc-Si PV in Gobi desert is the best option.

  17. First report of metacercariae of Cyathocotyle prussica parasitising a fish host in the Czech Republic, Central Europe

    Directory of Open Access Journals (Sweden)

    Kvach Y.

    2016-09-01

    Full Text Available Examination of western tubenose goby (Proterorhinus semilunaris from the River Dyje (Czech Republic, Danube basin for metazoan parasites revealed the presence of metacercariae of Cyathocotyle prussica Mühling, 1896 (Digenea: Cyathocotylidae in both muscle tissue and the peritoneal cavity. This is the first time that tubenose gobies have been reported as an intermediate host for C. prussica, and the first time that C. prussica metacercariae have been registered parasitising fish hosts in the Czech Republic. Here, we describe the morphology of metacercariae and five-day preadults, cultivated in vitro, and discuss the importance of recently established, non-native species as suitable hosts for this parasite.

  18. Factors influencing epibenthic assemblages in the Minho Estuary (NW Iberian Peninsula).

    Science.gov (United States)

    Costa-Dias, Sérgia; Freitas, Vânia; Sousa, Ronaldo; Antunes, Carlos

    2010-01-01

    The epibenthic community of the Minho Estuary was studied during the summer of 2006. Diversity was generally low and a total of 14 fish and five crustacean taxa were identified. Multivariate analysis revealed two site clusters (A and B). Water conductivity and percentage of fine sand were the abiotic variables that most contributed to the spatial distinction between clusters. The species contributing the most to the average similarity within Cluster A were Crangon crangon and Pomatoschistus microps, while in Cluster B was Atyaephyra desmarestii. Possible factors responsible for the low diversity of the epibenthic community in Minho Estuary were the low macrozoobenthic abundance and diversity, and the high abiotic oscillations between tides (mainly salinity) acting on the ecosystem. Copyright 2010 Elsevier Ltd. All rights reserved.

  19. Detailed Project Report. Liza Jackson Park. Shoreline Erosion Control at Fort Walton Beach, Florida.

    Science.gov (United States)

    1984-06-01

    Nt (,;’own goby (Microgobius gulus F, R, Nu, P Co’jia3 (Rachycentron canadum) F Code jzoby (Gobiosoma robustum) F, R, Nu, P Cowaose ray ( Rhinoptera ... bonasus ) F C:rcvalle jack (Caranx hipos F 1.)rida !LIennv (Chasmodes saburrae) F, R, Nu, P riorida pompano (Trachinotus carolinus) F, R, Nu, P Vringed

  20. Climate Change | Page 75 | IDRC - International Development ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Read more about Sri Lanka better prepared for future tsunamis. Language English. Gabin Koto N'Gobi's research focuses on water. But it was the lack of water in the semi-arid northern region of his home country, Benin, which really motivated him. Read more about Every drop counts: Interview with awardee Gabin Koto N' ...

  1. (Teleostei: Gobiidae ) from the Pongolo floodplain, Zululand, South ...

    African Journals Online (AJOL)

    A new freshwater goby, Mugilogobius pongolensis sp. n. is described and figured as a species new to southern and eastern Africa. This record extends the zoogeographcal distribution of Mugilogobius Smitt, 1899, from the Indonesian archipelago and South Australia to the Indian Ocean and the eastern coast of Africa.

  2. Final Supplemental Environmental Assessment: Falcon I Launch Vehicle Program from SLC-4W Vandenberg Air Force Base, California

    Science.gov (United States)

    2005-09-06

    affected surface water, 3) adversely affected groundwater quantity or quality, or 4) caused a need that exceeded the existing potable supply or...goby is from Tillas Slough (mouth of the Smith River) in Del Norte County, south to Colonel Louis D. Van Mullem, Jr. (1-8-96-F/C-29) 5 Agua Hedionda

  3. Gyrodactylus proterorhini in its non-native range: distribution and ability to host-switch in freshwaters

    Czech Academy of Sciences Publication Activity Database

    Ondračková, Markéta

    2016-01-01

    Roč. 115, č. 8 (2016), s. 3153-3162 ISSN 0932-0113 R&D Projects: GA ČR(CZ) GAP505/12/2569 Institutional support: RVO:68081766 Keywords : Gobies * Gyrodactylidae * Introduction * Ponto-Caspian * Range expansion Subject RIV: EH - Ecology, Behaviour Impact factor: 2.329, year: 2016

  4. Search Results | Page 2 | IDRC - International Development ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Results 11 - 20 of 51 ... The Virtual Clinical Experience Courseware was distributed to all Master of Arts in Nursing (MAN) students enrolled in their first clinical course entitled Advanced ... Final technical report : GES information system to motivate reliable business relation for Gobi eco-system, January 2009 - January 2010.

  5. Long-term monitoring of native bullhead and invasive gobiids in the Danubian rip-rap zone

    Czech Academy of Sciences Publication Activity Database

    Janáč, Michal; Roche, Kevin Francis; Šlapanský, Luděk; Polačik, Matej; Jurajda, Pavel

    2018-01-01

    Roč. 807, č. 1 (2018), s. 263-275 ISSN 0018-8158 R&D Projects: GA ČR(CZ) GBP505/12/G112 Institutional support: RVO:68081766 Keywords : Competition * Fish population structure * Invasive species impact * Ponto–Caspian gobies * River bank stabilisation Subject RIV: EG - Zoology Impact factor: 2.056, year: 2016

  6. Environmental Security: A Strategy for the Mitigation of Regional Instabilities?

    Science.gov (United States)

    2003-04-07

    ADAPTED FROM GLEICK, THE WORLD’S WATER 2000-2001). Another growing loss of arable land is caused by desertification . Desertification describes a...63 A similar situation is occurring in China where the Chinese Environmental Protection Agency estimates that the Gobi desert has expanded over

  7. Parasite diversity and microsatellite variability in native and introduced populations of four Neogobius species (Gobiidae)

    Czech Academy of Sciences Publication Activity Database

    Ondračková, Markéta; Šimková, A.; Civáňová, K.; Vyskočilová, M.; Jurajda, Pavel

    2012-01-01

    Roč. 139, č. 11 (2012), s. 1493-1505 ISSN 0031-1820 R&D Projects: GA ČR(CZ) GAP505/11/1768 Institutional support: RVO:68081766 Keywords : goby * metazoan parasites * microsatellites * similarity * species introductions Subject RIV: EG - Zoology Impact factor: 2.355, year: 2012

  8. Complete mitochondrial genome sequence of Tridentiger bifasciatus and Tridentiger barbatus (Perciformes, Gobiidae): a mitogenomic perspective on the phylogenetic relationships of Gobiidae.

    Science.gov (United States)

    Jin, Xiaoxiao; Wang, Rixin; Wei, Tao; Tang, Da; Xu, Tianjun

    2015-01-01

    The fishes of suborder Gobioidei is the largest group of those in present living Perciformes, which contains about 2,200 species belonging to 270 genera of 9 families in the world. The monophyly and phylogenetic relationships of gobies have been controversial and disputable for a long time. In the present study, the complete mitochondrial genome of the shimofuri goby Tridentiger bifasciatus (T. bifasciatus) and shokihaze goby Tridentiger barbatus (T. barbatus) were firstly determined. The two mitochondrial genomes were both consisted of 2 ribosomal RNA (rRNA) genes, 13 protein-coding genes, 22 transfer RNA (tRNA) genes, and one major control region (CR). They shared similar features with those of other gobies in terms of gene arrangement, base composition, and tRNA structures. The CR was absence of typical conserved blocks (CSB-E, and CSB-F) respectively for the T. bifasciatus and T. barbatus. Phylogenomic analyses, which based on 12 concatenated protein-coding genes and complete mitochondrial genome sequences, revealed that there were two groups within the Gobiidae. A large group consisted of the Amblyopinae, Gobionellinae, Oxudercinae and Sicydiinae, and Amblyopinae was nested in Oxudercinae and they were both paraphyletic to Sicydiinae. The other group was the Gobiinae. As a whole, our phylogenetic data was different from the traditionally classification of Gobiidae, but supported the new phylogenetic taxonomy view of Thacker (Copeia 2009:93-104, 2009).

  9. Social organisation and competition for refuges and nest sites in Coryphopterus nicholsii

    NARCIS (Netherlands)

    Kroon, F.J.; Graaf, de M.; Liley, N.R.

    2000-01-01

    The ability of larger males to control resources and monopolise spawnings is thought to explain the benefits of protogyny in some animals. Here we describe the breeding and non-breeding social organisations of a temperate protogynous goby, Coryphopterus nicholsii, in the light of this prediction.

  10. U. S. Navy Deepening of Pinole Shoal and Mare Island Strait Regulatory Permit Application by the Commander, Mare Island Shipyard, Solano County, California.

    Science.gov (United States)

    1981-07-01

    which feed on the loc, . -,’? " "",’ lation include gobies, sculpins, flounder, sole, sharks and ra-.. .. ders are a popular sportfish found in the area...force of employees if the Shipyard were to remain open on a limited work basis or the Shipyard could ultimately be closed. 4.119 Alternativas #2 and #3

  11. Surviving off junk: low-energy prey dominates the diet of African ...

    African Journals Online (AJOL)

    Since the collapse of pelagic fish stocks in the 1970s, birds fed mainly on bearded (pelagic) goby Sufflogobius bibarbatus, a low-energy prey species. ... and low prey quality rather than low abundance appears to be a key factor influencing population dynamics of African penguins and other marine top predators in southern ...

  12. Protecting Mongolia's grassland steppes | CRDI - Centre de ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Indeed, Mongolia's own National Environmental Action Plan warns that the Gobi Desert in the country's southern region may be advancing northward by as much ... "Beginning in the 1990s, herders have had to manage agriculture activities using their own knowledge — everything from herding to production to marketing to ...

  13. Feeding ecology and niche overlap of Lake Ontario offshore forage fish assessed with stable isotopes

    Science.gov (United States)

    Mumby, James; Johson, Timothy; Stewart, Thomas; Halfyard, Edward; Walsh, Maureen; Weidel, Brian C.; Lantry, Jana; Fisk, Aarron

    2017-01-01

    The forage fish communities of the Laurentian Great Lakes continue to experience changes that have altered ecosystem structure, yet little is known about how they partition resources. Seasonal, spatial and body size variation in δ13C and δ15N was used to assess isotopic niche overlap and resource and habitat partitioning among the five common offshore Lake Ontario forage fish species (n = 2037) [Alewife (Alosa pseudoharengus), Rainbow Smelt (Osmerus mordax), Round Goby (Neogobius melanostomus), and Deepwater (Myoxocephalus thompsonii) and Slimy (Cottus cognatus) Sculpin]. Round Goby had the largest isotopic niche (6.1‰2, standard ellipse area (SEAC)), followed by Alewife (3.4‰2) while Rainbow Smelt, Slimy Sculpin and Deepwater Sculpin had the smallest and similar niche size (1.7-1.8‰2), with only the Sculpin species showing significant isotopic niche overlap (>63%). Stable isotopes in Alewife, Round Goby and Rainbow Smelt varied with location, season and size, but did not in the Sculpin spp. Lake Ontario forage fish species have partitioned food and habitat resources, and non-native Alewife and Round Goby have the largest isotopic niche, suggestive of a boarder ecological niche, and may contribute to their current high abundance.

  14. Description of two new species from the genera Palaemonella Dana, 1852 and Vir Holthuis, 1952 (Crustacea: Caridea: Palaemonidae: Pontoniinae)

    NARCIS (Netherlands)

    Marin, I.N.

    2008-01-01

    Two new species, Palaemonella aliska spec. nov. and Vir longidactylus spec. nov. are described from Nhatrang Bay, Vietnam. Palaemonella aliska spec. nov., collected from the holes burrowed by Alpheus cf. bellulus Miya & Miyake, 1969 and an unidentified goby, clearly diff ering from the remained

  15. Pardaxin permeabilizes vesicles more efficiently by pore formation than by disruption

    DEFF Research Database (Denmark)

    Vad, Brian S; Bertelsen, Kresten; Johansen, Charlotte Hau

    2010-01-01

    Pardaxin is a 33-amino-acid neurotoxin from the Red Sea Moses sole Pardachirus marmoratus, whose mode of action shows remarkable sensitivity to lipid chain length and charge, although the effect of pH is unclear. Here we combine optical spectroscopy and dye release experiments with laser scanning...... confocal microscopy and natural abundance (13)C solid-state nuclear magnetic resonance to provide a more complete picture of how pardaxin interacts with lipids. The kinetics and efficiency of release of entrapped calcein is highly sensitive to pH. In vesicles containing zwitterionic lipids (PC), release...

  16. A new Synbranchus (Teleostei: Synbranchiformes: Synbranchidae from ilha de Marajó, Pará, Brazil, with notes on its reproductive biology and larval development

    Directory of Open Access Journals (Sweden)

    Sandra E. Favorito

    Full Text Available Synbranchus lampreia, new species, is described from rio Goiapi, Marajó Island, Pará, northern Brazil. It differs from the other two described species of the genus by its color pattern, which consists of large roundish black blotches scattered over a light brown or yellowish ground pigmentation and presence of inconspicuous brown small spots distributed among the large dark spots. The species is further distinguished from S. marmoratus by a higher number of vertebrae and from S. madeira by a shorter postanal length. Information about reproductive aspects is provided and larval stages are described and illustrated.

  17. Cytogenetic analyses of eight species in the genus Leptodactylus Fitzinger, 1843 (Amphibia, Anura, Leptodactylidae), including a new diploid number and a karyotype with multiple translocations

    Science.gov (United States)

    2012-01-01

    Background The karyotypes of Leptodactylus species usually consist of 22 bi-armed chromosomes, but morphological variations in some chromosomes and even differences in the 2n have been reported. To better understand the mechanisms responsible for these differences, eight species were analysed using classical and molecular cytogenetic techniques, including replication banding with BrdU incorporation. Results Distinct chromosome numbers were found: 2n = 22 in Leptodactylus chaquensis, L. labyrinthicus, L. pentadactylus, L. petersii, L. podicipinus, and L. rhodomystax; 2n = 20 in Leptodactylus sp. (aff. podicipinus); and 2n = 24 in L. marmoratus. Among the species with 2n = 22, only three had the same basic karyotype. Leptodactylus pentadactylus presented multiple translocations, L. petersii displayed chromosome morphological discrepancy, and L. podicipinus had four pairs of telocentric chromosomes. Replication banding was crucial for characterising this variability and for explaining the reduced 2n in Leptodactylus sp. (aff. podicipinus). Leptodactylus marmoratus had few chromosomes with a similar banding patterns to the 2n = 22 karyotypes. The majority of the species presented a single NOR-bearing pair, which was confirmed using Ag-impregnation and FISH with an rDNA probe. In general, the NOR-bearing chromosomes corresponded to chromosome 8, but NORs were found on chromosome 3 or 4 in some species. Leptodactylus marmoratus had NORs on chromosome pairs 6 and 8. The data from C-banding, fluorochrome staining, and FISH using the telomeric probe helped in characterising the repetitive sequences. Even though hybridisation did occur on the chromosome ends, telomere-like repetitive sequences outside of the telomere region were identified. Metaphase I cells from L. pentadactylus confirmed its complex karyotype constitution because 12 chromosomes appeared as ring-shaped chain in addition to five bivalents. Conclusions Species of Leptodactylus exhibited both major and minor

  18. Comparative cytogenetic analysis of four species of Dendropsophus ...

    Indian Academy of Sciences (India)

    D. carnifex(2). D. anceps(1). 58. D. ebraccatus(3) sm sm m st st sm sm sm m t sm m sm m sm. 10q, 13q. 58. D. elegans(4) sm sm m sm st sm sm m m m st sm m st st. 10, 14. 52. D. elegans(*) sm sm m sm st m m m m m st m m t t. 13q. 56. D. leucophyllatus(1). 54. D. labialis(1). 50. D. marmoratus(5) sm sm m sm t t t m m m m m.

  19. Increased piscivory by lake whitefish in Lake Huron

    Science.gov (United States)

    Pothoven, Steven A.; Madenjian, Charles P.

    2013-01-01

    We evaluated the diet of Lake Whitefish Coregonus clupeaformis in Lake Huron during 2002–2011 to determine the importance of Round Goby Neogobius melanostomus and other fish as prey items. Lake Whitefish that had reached approximately 400 mm in length incorporated fish into their diets. The overall percentage of adult Lake Whitefish in Lake Huron that had eaten fish increased from 10% in 2002–2006 to 20% in 2007–2011, with a corresponding decrease in the frequency of Lake Whitefish that ate Dreissena spp. from 52% to 33%. During 2002–2006, Round Goby (wet mass, 38%), sculpins (Cottidae) (34%), and Ninespine Stickleback Pungitius pungitius (18%) were the primary fish eaten, whereas Round Goby accounted for 92% of the fish eaten in 2007–2011. Overall, Round Goby were found in the fewest Lake Whitefish stomachs in the north region of Lake Huron (6%) and in the most in the central (23%) and south (19%) regions of the lake. In the central region, Round Goby were eaten during all seasons that were sampled (spring through fall). In the south region, Round Goby were eaten only in the winter and spring but not in the summer when Dreissena spp. and spiny water flea Bythotrephes longimanus dominated the diet. Based on the 2007–2011 diet composition, an individual Lake Whitefish would need to have increased their consumption relative to that in 1983–1994 by 6% in the north region, 12% in the central region, and 41% in the southern region in order to achieve the same growth that was observed before dreissenid mussels arrived. However, Lake Whitefish weight adjusted for length only increased by 2% between 2002–2006 and 2007–2011 in the central region, decreased by 4% in the northern region, and remained constant in the southern region. This suggests that a shift toward more frequent piscivory does not necessarily improve the condition of a generalist feeder like Lake Whitefish.

  20. Early Pliocene anuran fossils from Kanapoi, Kenya, and the first fossil record for the African burrowing frog Hemisus (Neobatrachia: Hemisotidae).

    Science.gov (United States)

    Delfino, Massimo

    2017-07-13

    Isolated amphibian bones from the early Pliocene of Kanapoi (West Turkana, Kenya) help to improve the scarce fossil record of the late Neogene and Quaternary amphibians from East Africa. All currently available 579 bones are referable exclusively to the Anura (frogs and toads). More than half of the remains (366) are identified as Hemisus cf. Hemisus marmoratus, an extant species that still inhabits Kenya, but apparently not the northwest of the country and the Turkana area in particular. The rest of the remains are identified simply as Anura indet. because of poor preservation or non congruence with the relatively few African extant taxa whose osteology is known in detail. The Hemisus material represents the first fossil record for Hemisotidae, an endemic African family of peculiar, head-first burrowing frogs, whose sister taxon relationships indicate a divergence from brevicipitids in the Late Cretaceous or early Paleocene. The ecological requirements of extant H. marmoratus suggest that the Kanapoi area surrounding the fluvial and deltaic settings, from where the fossil remains of vertebrates were buried, was likely a grassland or relatively dry, open low tree-shrub savanna. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. The trade-off between heat tolerance and metabolic cost drives the bimodal life strategy at the air-water interface

    KAUST Repository

    Fusi, Marco

    2016-01-13

    The principle of oxygen and capacity limitation of thermal tolerance in ectotherms suggests that the long-term upper limits of an organism\\'s thermal niche are equivalent to the upper limits of the organism\\'s functional capacity for oxygen provision to tissues. Air-breathing ectotherms show wider thermal tolerances, since they can take advantage of the higher availability of oxygen in air than in water. Bimodal species move from aquatic to aerial media and switch between habitats in response to environmental variations such as cyclical or anomalous temperature fluctuations. Here we tested the prediction that bimodal species cope better with thermal stress than truly aquatic species using the crab Pachygrapsus marmoratus as a model species. When in water, oxygen consumption rates of P. marmoratus acutely rise during warming. Beyond a temperature threshold of 23 °C the crab\\'s aerobic metabolism in air remains lower than in water. In parallel, the haemolymph oxygen partial pressure of submerged animals progressive decreases during warming, while it remains low but constant during emersion. Our results demonstrate the ability of a bimodal breathing ectotherm to extend its thermal tolerance during air-breathing, suggesting that there are temperature-related physiological benefits during the evolution of the bimodal life style.

  2. Distinguishing the provenance of fine-grained eolian dust over the Chinese Loess Plateau from a modelling perspective

    OpenAIRE

    Shi, Zhengguo; Liu, Xiaodong

    2011-01-01

    The provenance of fine-grained eolian dust over East Asia is distinguished using a regional climate model. Five major source regions within China and Mongolia are considered: sandy lands in the northeastern China, deserts in the northern China, the Gobi deserts, the Taklimakan deserts in western China and deserts on the Tibet an Plateau. The contribution of each dust source is evaluated for the downwind eolian sediments in the Chinese Loess Plateau (CLP) and Japan Sea (JS). The results show t...

  3. A new discovery of Glossopteris in southeastern Mongolia as an argument for distant migration of Gondwanan plants

    Science.gov (United States)

    Naugolnykh, Serge V.; Uranbileg, L.

    2018-04-01

    Well-preserved leaves conforming to the fossil genus Glossopteris are found in the Permian deposits of southeastern Gobi, Khatan-Bulag locality, Mongolia. These leaves have many features in common with Glossopteris communis Feistmantel described from India. The locality Khatan-Bulag belongs to Sulinkheer nappe-fold tectonic megazone. The Glossopteris sp. cf. G. communis specimens from the Khatan-Bulag suggest that there was effective migration gateway between Gondwana and southern regions of Asia in the mid-Permian.

  4. Rangeland management and climate hazards in drylands: dust storms, desertification and the overgrazing debate

    OpenAIRE

    Middleton, N

    2016-01-01

    This paper examines the theory and supporting evidence for links between desertification, drought and dust storms with a particular focus on studies undertaken in and around the Gobi Desert. Overgrazing of rangeland by pastoralists has been the most commonly cited cause of desertification in global drylands for more than 30 years, but the evidence supporting this link is not always convincing. Nonetheless, overgrazing, desertification and dust storms are frequently connected, regardless. Drou...

  5. Indole chemistry for combating yellow sand and desertification directed towards stopping global warming

    OpenAIRE

    Somei, Masanori

    2011-01-01

    Various derivatives of indole-3-carbaldehyde are found to be root regulators and they are named SOMRE compounds. Since some of them are potent root promoters and make roots three times longer than usual, their possibilities for increasing food production, combating yellow sand and desertification in Gobi desert, China, were examined. All preliminary experiments are thus far working well. For greening desert and stopping the global warming, it is vital importance to sow seeds to vast area of s...

  6. Desert Studies - A Global View

    Science.gov (United States)

    1985-08-23

    International School of Climatology course on the climatic aspects of desertification in Erice, Italy (Breed, 1983; Breed and others, 1983). In 1983...Tengger, Kumuntag, Garbantunggut, Turpan, and Talkimakan sand seas and gobi plains. As a member of this group, Ms. Breed was the first Western...Winds Project, in Ypersele, J. P. (ed.), Climatological aspects of desertification : Proceedings of the International School of Climatology, Erice

  7. Geomorphic Aspects of China’s Desertification Problem and De-Desertification Efforts.

    Science.gov (United States)

    1984-12-01

    Shapotou J deserts loess Hotan desertification sand dunes Talkimakan Desert LL irrigation gobi Desert Research Institute, Lanzhou Ck. 2?- AM--%ACT tCh...AD-A153 251 GEOMORPHIC ASPECTS OF CHINAl’S DESERTIFICATION PROBLEM ini AND DE-DESERTIFICRTION EFFORTS(U) GEOLOGICAL SURVEY FLAGSTAFF AZ C S BREED DEC...VC0100COVEMED Geomorphic aspects of China’s desertification Technical: problem and de- desertification efforts July 1-Dec. 31, 1984 ___ 6 P(NICfsmgwG ONG

  8. Drylands and desertification

    OpenAIRE

    Escadafal, Richard

    2016-01-01

    Regions with dry climates cover a large part of the world’s landmass (more than 40%). Collectively known by the English term "drylands", they encompass a wide range of ecosystems, including the American "deserts" of California, Nevada and Mexico ; the vast steppes of Central Asia and North Africa ; the Sahelian savannah and real deserts such as the Sahara in Africa or the Gobi in China.

  9. Arboristická problematika boje s desertifikací na příkladu Velké zelené zdi v Číně

    OpenAIRE

    Matoušková, Marie

    2015-01-01

    Northern China is subdued to serious desertification caused by expansion of the Gobi Desert, mostly in the southern direction. There are several ways how minimize desertification as one of global environmental problems. One of the really extensive and long-term projects in stopping progress of the desert is the Chinese Great Green Wall, an artificial belt of trees planted to improve environmental characteristics and living conditions of people throughout northern China, eventually in the whol...

  10. Long-term trends in daily temperature extremes over Mongolia

    OpenAIRE

    Dashkhuu, Dulamsuren; Kim, Jong Pil; Chun, Jong Ahn; Lee, Woo-Seop

    2015-01-01

    Various indices have been used to investigate recent changes in the annual frequencies of extreme temperature events in Mongolia. A high-quality daily temperature dataset including 53 station records was used to determine trends from 1961 to 2010. The Climdex1.0 software was used to calculate 11 extreme temperature indices for this study. The results showed significant changes in important temperature indices over the study period, especially in the Gobi Mongolia. The analysis showed that an ...

  11. Organochlorine contaminants (PCBs, DDTs, HCB

    OpenAIRE

    Georgieva Stanislava; Stancheva Mona; Makedonski Lubomir

    2015-01-01

    Concentrations of organochlorine compounds such as polychlorinated biphenyls (PCBs), DDT and its metabolites, hexachlorobenzene (HCB) and hexachlorobutadiene (HBDE) were determined in three fish species: goby (Neogobius melanostomus), golden grey mullet (Mugil auratus) and silverside (Atherina boyeri). Samples were collected from the Lake Varna and the Lake Beloslav in 2014. The edible fish tissues were analyzed in order to investigate the presence of pollutants in species from the lakes near...

  12. Ecological tracers reveal resource convergence among prey fish species in a large lake ecosystem

    Science.gov (United States)

    Paterson, Gord; Rush, Scott A.; Arts, Michael T.; Drouillard, Ken G.; Haffner, G. Doug; Johnson, Tim B.; Lantry, Brian F.; Hebert, Craig E.; McGoldrick, Daryl J.; Backus, Sean M.; Fisk, Aaron T.

    2014-01-01

    1. We measured stable isotopes of carbon (δ13C) and nitrogen (δ15N) and fatty acid profiles in Lake Ontario alewife (Alosa pseudoharengus), rainbow smelt (Osmerus mordax), slimy sculpin (Cottus cognatus) and round goby (Neogobius melanostomus) collected from 1982 to 2008 to investigate how temporal variability in these ecological tracers can relate to ecosystem-level changes associated with the establishment of highly invasive dreissenid mussels.

  13. Isotopic and geochemical evidence of recharge sources and water quality in the Quaternary aquifer beneath Jinchang city, NW China

    International Nuclear Information System (INIS)

    Ma Jinzhu; Pan Feng; Chen Lihua; Edmunds, W. Mike; Ding Zhenyu; He Jianhua; Zhou Kunpeng; Huang Tianming

    2010-01-01

    Multiple isotopic and hydrogeochemical tracers were utilized to understand the recharge sources and geochemical evolution of groundwater in the Quaternary aquifer beneath Jinchang city and the adjacent Gobi desert area. The groundwater shows markedly depleted stable isotopic composition compared to modern rainfall. The signature of groundwaters from Jinchang and the northern Gobi desert area differ clearly from that of the alluvial fan in the south Yongchang basin and modern rainfall, and has lower or non-detectable 3 H activity, implying that the aquifer is likely maintained by palaeowater. This groundwater in the Gobi desert has a 14 C age older than 12 ka, indicating that the groundwater resources are non-renewable. The build-up of dissolved solids through evaporation is a major control on groundwater composition, and the dominant anion species change systematically from HCO 3 - , SO 4 2- to Cl - , but cations from weathering of albite, calcite, dolomite and gypsum also make a significant contribution. The scientific results have important implications for groundwater management in Jinchang city and as well as in the Shiyang River basin under China's West Development Strategy. It is recommended that the water allocation program of diverting water from the Dongda river to the Minqin basin be reconsidered.

  14. Parapapillary Diffuse Choroidal Atrophy in Children Is Associated With Extreme Thinning of Parapapillary Choroid.

    Science.gov (United States)

    Yokoi, Tae; Zhu, Dan; Bi, Hong Sheng; Jonas, Jost B; Jonas, Rahul A; Nagaoka, Natsuko; Moriyama, Muka; Yoshida, Takeshi; Ohno-Matsui, Kyoko

    2017-02-01

    To analyze morphologic features of segmental parapapillary diffuse choroidal atrophy (PDCA) in children. The study group included children (age ≤15 years) with high myopia who attended the Tokyo High Myopia Clinic. Control groups comprised participants of the population-based Gobi Desert Children Eye Study (GobiDCES). Fundus photographs were examined for presence of PDCA and choroidal thickness (CT) was measured by optical coherence tomography. The study group included 41 eyes of 21 children with PDCA (mean age: 9.4 ± 3.7 years; mean refractive error: -11.5 ± 3.1 diopters) and the GobiDCES included 1463 children (age: 11.8 ± 3.5 years). In the study group, all eyes showed an extreme and abrupt thinning of the temporal parapapillary choroid. At 2500 μm nasal to the foveola, CT was PDCA. Parapapillary diffuse choroidal atrophy in children is associated with abrupt segmental thinning of the choroid in the temporal parapapillary region, in addition to the thinning of the subfoveal choroid after adjusting for refractive error and age.

  15. Proteolytic activity in some freshwater animals and associated microflora in a wide pH range.

    Science.gov (United States)

    Kuz'mina, V V; Zolotareva, G V; Sheptitskiy, V A

    2017-04-01

    Proteolytic activity in some freshwater animals (crustacean plankton, sandhopper Amphipoda sp., larvae of chironomids Chironomus sp., oligochaetes Oligohaeta sp., dreissena Dreissena polymorpha, roach Rutilus rutilus heckelii, rudd Scardinius erythrophthalmus, ruff Acerina cernua, and monkey goby Neogobius fluviatilis) prevailing within the food of fishes of various ecological groups as well as in their associated microflora in a wide pH range was investigated. It has been shown that the optimum pH of proteases in the animals' whole organism varies: 6.0 for sandhopper; 8.0 for chironomid larvae, oligochaetes, monkey goby, and ruff; 8.0-9.0 for zooplankton; and 10.0 for roach and rudd. The optimum pH of associated microflora proteases is 6.0 for monkey goby; 7.0 for sandhopper and roach and ruff ; 8.0-9.0 for oligochaetes; 9.0 for zooplankton; and 10.0 for chironomid larvae and rudd. The compensatory role of food items and enteric microbiota proteases in digestive processes in fish of different ecological groups at low pH is discussed.

  16. First detection of circovirus-like sequences in amphibians and novel putative circoviruses in fishes.

    Science.gov (United States)

    Tarján, Zoltán László; Pénzes, Judit J; Tóth, Róza P; Benkő, Mária

    2014-03-01

    The negative samples of a collection, established originally for seeking new adeno- and herpesviruses in lower vertebrates, were screened for the pres-ence of circoviruses by a consensus nested PCR targeting the gene coding for the replication-associated protein. Six fish samples representing five species, namely asp (Aspius aspius), roach (Rutilus rutilus), common bream (Abramis brama), round goby (Neogobius melanostomus) and monkey goby (Neogobius fluviatilis), as well as three frog samples were found positive for circoviral DNA. Sequence analysis of the amplicons indicated the presence of three novel putative circo-like viruses and a circovirus in Hungarian fishes and one novel circovirus in a common toad (Bufo bufo), and another one in a dead and an alive specimen of green tree frog (Litoria caerulea), respectively. In phylogeny reconstruction, the putative bream circovirus clustered together with circoviruses discovered in other cyprinid fishes recently. Three other piscine circoviral sequences appeared closest to sequences derived from different environmental samples. Surprisingly, the nucleotide sequence derived from two fish samples (a bream and a monkey goby) proved to be from porcine circovirus 2 (PCV2), almost identical to a sequence detected in Sweden previously. This is the first report on the detection of PCV2 in fish and circoviral DNA in amphibian hosts.

  17. Attenuation of regional seismic phases (Lg and Sn) in Eastern Mongolia

    Science.gov (United States)

    He, Jing; Sandvol, Eric; Wu, Qingju; Gao, Mengtan; Gallegos, Andrea; Ulziibat, Munkhuu; Demberel, Sodnomsambuu

    2017-11-01

    We present tomographic models of frequency-dependent Lg and Sn attenuation in eastern Mongolia using data from 228 local earthquakes that were recorded by 69 broad-band seismic stations. We adopt the two-station method (TSM) and reverse two-station method (RTM) to measure the frequency-dependent Sn and Lg Q values, respectively. The RTM has the advantage of allowing us to make attenuation measurements that are independent of site effects, instrument responses and source parameters. We have tomographically mapped Lg Q and η in order to understand spatial variations in crustal attenuation across eastern Mongolia and the surrounding regions. High Lg attenuation and low η are found in the volcanic region of the Middle Gobi Desert, while high Lg attenuation and high η are found in and around the tectonically active regions of the South Gobi Desert. We have also examined uppermost mantle attenuation by mapping the variation in Sn attenuation and η values. Regions of high Sn attenuation are found in the mountainous and volcanically active regions of the Middle Gobi Desert. Our Lg and Sn attenuation models correlate well with lateral variations in velocity as well as with the major tectonic units that make up eastern Mongolia. High attenuation regions seem to be associated with low velocities, Quaternary volcanoes and Cenozoic tectonic activity.

  18. Age and growth of Crystallogobius linearis (von Düben, 1845 (Teleostei: Gobiidae from the Adriatic Sea

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    M. La Mesa

    2001-12-01

    Full Text Available Age and growth of the crystal goby Crystallogobius linearis (von Düben, 1845 were investigated by means of daily growth increment counts on the sagittal otoliths. Samples of C. linearis, obtained as by-catch of the Aphia minuta fishery, were collected in a coastal area of the central Adriatic Sea between March and September 1996. Otolith age-readings were carried out on 167 specimens, ranged from 14 to 41 mm of total length, and indicated that the population was composed of individuals from two to seven months old. Growth of both males and females appeared practically linear over the whole size range studied, although in females a slight decrease in growth rate of older specimens was observed. Furthermore, the hatch date distribution of C. linearis, obtained by the backcalculation of the ageing data, indicated a long breeding season of at least eight months. The results of this study indicated that, as reported from literature for most nektonic gobies, the crystal goby is also characterised by a short life span, during which a high reproductive effort is displayed throughout a long breeding season.

  19. The tale of two continents

    International Nuclear Information System (INIS)

    Ednie, H.

    2007-01-01

    This article discussed the development of coal resources in Mongolia by Vancouver-based Ivanhoe Mines. SouthGobi Energy Resources is the largest holder of coal lands under exploration in Mongolia, with 2.3 million hectares, comprising 54 exploration licenses. The properties are located in the southern part of Mongolia in the Gobi Desert bordering China. The opportunities for developing coal from Mongolia to be sold to China were summarized. Ovoot Tolgoi is the most advanced of SouthGobi's projects, with 150 million tonnes of coal resources measured and indicated. The initial plan is for the development of a surface mine. A detailed environmental assessment has been completed and approved. The development plans have also been accepted by local communities. Mining equipment will be purchased once the mining license is granted. The operation will start at 1 million tonnes per year, then increase to 5 million tonnes per year in 5 years. The coal is continuous at depth, and plans for an underground operation have already begun. This article also discussed the challenges of conducting business in Mongolia and improving the infrastructure to support the development of mining operations. 3 figs

  20. Twelve invertebrate and eight fish species new to the marine fauna of Madeira, and a discussion of the zoogeography of the area

    Science.gov (United States)

    Wirtz, Peter

    1998-06-01

    The benthic ctenophore Vallicula multiformis, a large undescribed flatworm species of the genus Pseudoceros, the prosobranch gastropod Tonna maculosa, the opisthobranch gastropods Placida cf. dendritica, Caloria elegans, Aeolidiella sanguinea, Janolus cristatus, the decapod Balssia gasti, the sea urchin Schizaster canaliferus and the tunicates Clavelina lepadiformis, Clavelina dellavallei and Pycnoclavella taureanensis are recorded from Madeira for the first time. This is the first record of a platyctenid ctenophore in the eastern Atlantic. The teleost fishes Pomatoschistus pictus, Vaneaugobius canariensis, Chromogobius sp., Nerophis ophidion, Hippocampus hippocampus, Acanthocybium solandri, Sphyraena viridensis and Sphyraena barracuda are recorded from Madeira for the first time. The presence of the sea-hare Aplysia dactylomela at Madeira is confirmed; the species has increased tremendously in abundance in the last four years. The crocodile fish Grammoplites gruveli can occasionally be found in the mantle cavity of cuttlefish ( Sepia officinalis) sold at the fish market of Funchal, but does not originate from Madeiran waters. An analysis of 100 new records from the coastal fauna of Madeira shows that, while predominantly of lusitanian, mediterranean and mauritanian affinity, Madeira’s shallow water fauna contains a large component of tropical species.

  1. Inter-annual differences of ichthyofauna structure of the Guadiana estuary and adjacent coastal area (SE Portugal/SW Spain): Before and after Alqueva dam construction

    Science.gov (United States)

    Chícharo, M. Alexandra; Chícharo, Luis; Morais, Pedro

    2006-10-01

    The objective of this study was to evaluate how inter-annual changes in the volume of freshwater input and water parameters (salinity, temperature, major dissolved nutrients, seston and chlorophyll a) affect fish assemblages in the Guadiana estuary (South Portugal). During the sampling period (two distinct hydrological years), 56 fish species were identified. Anchovies ( Engraulis encrasicolus) and barbells ( Barbus species) dominated the abundances in the high inflow year (2001), but Pomatoschistus species were the most important taxa in the low inflow year (2002). Barbells and Portuguese toadfish ( Halobatrachus didactylus) dominated the biomass in both years under different inflow conditions, but a reduction in barbells' biomass occurred during the low inflow year. Multivariate analysis indicated a persistent spatial structuring of the estuarine community for both years and in different seasonal periods. Changes in salinity and seston, which were mainly due to changes in freshwater input, had an important influence on the structure of the fish assemblages. In 2002, the increased salinity in the upper estuary allowed colonization by marine species of an area that usually contains freshwater, decreasing even more the habitat for indigenous freshwater species in the downstream area of the Guadiana River. There was also a decrease in the abundances of planktivorous and omnivorous fishes and an increase in carnivorous fishes during the low inflow year. As fishes in these systems are important regulators of processes in the trophic web, changes in the dominant feeding groups can have consequences on water quality, particularly in relation to the occurrence of plankton blooms.

  2. Short-term variability of fish condition and growth in estuarine and shallow coastal areas.

    Science.gov (United States)

    Duarte, Irina A; Vasconcelos, Rita P; França, Susana; Batista, Marisa I; Tanner, Susanne; Cabral, Henrique N; Fonseca, Vanessa F

    2018-03-01

    Short-term variability in condition factor: relative condition factor Kn; biochemical condition: RNA:DNA and protein content; and instantaneous growth rates were determined in estuarine and coastal fish. Dicentrarchus labrax, Solea senegalensis and Pomatoschistus microps were sampled in the Tejo estuary, while Trachurus trachurus was sampled in an adjacent shallow coastal area. Variation of condition indices was more frequent at the week scale (sampling periods with fortnight intervals) than at the daily scale (consecutive days in each sampling period) in all species. Water temperature was correlated with biochemical indices, while salinity showed no effect, evidencing the influence of environmental short-term variation (temperature) on biochemical condition in natural populations. Yet, decreasing individual variability in fish condition was observed along the sampled weeks, resulting in a more homogeneous condition of populations, particularly for T. trachurus likely due to a more stable coastal environment. Biochemical indices proved to be sensitive to short-term environmental variability, despite species-specific responses. Copyright © 2018 Elsevier Ltd. All rights reserved.

  3. Environmental factors affecting larval fish community in the salt marsh area of Guadiana estuary (Algarve, Portugal

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    Renata Gonçalves

    2015-03-01

    Full Text Available Salt marsh areas in the Guadiana estuary are important nursery sites for many fish species of commercial and recreational value. More effective protection measures should be adopted as the area is highly affected by anthropogenic and natural threats. Studying larval fish communities in these impacted nursery areas will be relevant to the management of local ecosystems and to larval fish ecology in general. Spatial and seasonal distribution and the effect of environmental factors on the larval fish community of this ecosystem were studied for one year (April 2010 to March 2011. Larvae were sampled monthly in parallel with phytoplankton and zooplankton. Hydrological data and physical parameters were monitored. A decision tree model was used to assess the influence of environmental factors on the larval fish community. A total of 130 larvae and 1171 eggs were caught. Diplodus sargus, Sardina pilchardus, and Pomatoschistus microps were the most abundant larval fish species. The peaks of fish larvae abundance occurred in March and April. The output of the model demonstrates that the abundance of larval fish is determined by the abundance of eggs, zooplanktonic food, and water flood and flow. This study shows the importance of the Guadiana salt marsh as an area for fish nursery and highlights the need for conservation of this area.

  4. Toxic effects of decomposing red algae on littoral organisms

    Science.gov (United States)

    Eklund, Britta; Svensson, Andreas P.; Jonsson, Conny; Malm, Torleif

    2005-03-01

    Large masses of filamentous red algae of the genera Polysiphonia, Rhodomela, and Ceramium are regularly washed up on beaches of the central Baltic Sea. As the algal masses start to decay, red coloured effluents leak into the water, and this tinge may be traced several hundred meters off shore. In this study, possible toxic effects of these effluents were tested on littoral organisms from different trophic levels. Effects on fertilisation, germination and juvenile survival of the brown seaweed Fucus vesiculosus were investigated, and mortality tests were performed on the crustaceans Artemia salina and Idotea baltica, as well as on larvae and adults of the fish Pomatoschistus microps. Fucus vesiculosus was the most sensitive species of the tested organisms to the red algal extract. The survival of F. vesiculosus recruits was reduced with 50% (LC50) when exposed to a concentration corresponding to 1.7 g l -1 dw red algae. The lethal concentration for I. baltica, A. salina and P. microps were approximately ten times higher. The toxicity to A. salina was reduced if the algal extract was left to decompose during two weeks but the decline in toxicity was not affected by different light or temperature conditions. This study indicates that the filamentous red algae in the central Baltic Sea may produce and release compounds with negative effects on the littoral ecosystem. The effects may be particularly serious for the key species F. vesiculosus, which reproduce in autumn when filamentous red algal blooms are most severe.

  5. Produção do híbrido "cachadia" em diferentes densidades de estocagem em sistema de recirculação de água

    OpenAIRE

    P.M.C Faria; R.K Luz; S.A Prado; E.M Turra; T.B.F Jorge; A.M.Q Lana; E.A Teixeira

    2011-01-01

    Avaliou-se o efeito da densidade de estocagem na produção de "cachadia" (Pseudoplatystoma fasciatum x Leiarius marmoratus) em sistema de recirculação de água. Nas duas primeiras fases, com duração de 27 e 40 dias e usando animais com média de peso inicial de 31 e 57g, respectivamente, foram testados 20, 40, 60 e 80 peixes/m³. Na terceira e quarta fase, usando peixes com média de peso de 169 e 399g durante 41 e 99 dias, respectivamente, foram testados 10, 20, 30 e 40 peixes/m³. A taxa de sobre...

  6. Diversidad y microestructura de quitones (Mollusca: Polyplacophora del Caribe de Costa Rica

    Directory of Open Access Journals (Sweden)

    Cedar I García-Ríos

    2011-03-01

    Full Text Available Los poliplacóforos asociados a los arrecifes de coral en la costa caribeña de Costa Rica han sido poco estudiados. El examen del cascajo de coral acumulado en el sublitoral somero, en cuatro estaciones de colección, localizadas en la Provincia de Limón reveló una diversidad de quitones mayor a la documentada. Anteriormente se habían registrado ocho especies para el Caribe costaricense: Ischnochiton erythronotus (C.B. Adams, 1845; Ischnoplax pectinata (Sowerby 1840; Stenoplax boogii (Haddon, 1886; S. purpurascens (C.B. Adams, 1845; Acanthopleura granulata (Gmelin, 1791; Chiton marmoratus Gmelin, 1791; C. tuberculatus Linnaeus, 1758; Acanthochitona rhodea (Pilsbry, 1893. Otras cinco se registran aquí por primera vez: Callistochiton portobelensis Ferreira 1976; Ischnochiton kaasi Ferreira 1987; I. pseudovirgatus Kaas 1972; Acanthochitona balesae Abbott 1954; Cryptoconchus floridanus (Dall 1889.

  7. New Curculionoidea (Coleoptera records for Canadа

    Directory of Open Access Journals (Sweden)

    Hume Douglas

    2013-06-01

    schevyrewi Semenov Tjan-Shansky, 1902; Tyloderma foveolatum (Say, 1832; (all Curculionidae; Ontario – Trichapion nigrum (Herbst, 1797; Nanophyes marmoratus marmoratus (Goeze, 1777 (both Brentidae; Asperosoma echinatum (Fall, 1917; Micracis suturalis LeConte, 1868; Orchestes alni (Linnaeus, 1758; Phloeosinus pini Swaine, 1915; Scolytus schevyrewi Semenov Tjan-Shansky, 1902; Xyleborinus attenuatus (Blandford, 1894 (all Curculionidae; Quebec – Trigonorhinus alternatus (Say, 1826; Trigonorhinus tomentosus tomentosus (Say, 1826 (both Anthribidae; Trichapion nigrum (Herbst, 1797; Trichapion porcatum (Boheman, 1839; Nanophyes marmoratus marmoratus (Goeze, 1777 (all Brentidae; Lissorhoptrus oryzophilus Kuschel, 1952 (Brachyceridae; Acalles carinatus LeConte, 1876; Ampeloglypter ampelopsis (Riley, 1869; Anthonomus rufipes LeConte, 1876; Anthonomus suturalis LeConte, 1824; Ceutorhynchus hamiltoni Dietz, 1896; Curculio pardalis (Chittenden, 1908; Cyrtepistomus castaneus (Roelofs, 1873; Larinus planus (Fabricius, 1792; Mecinus janthinus (Germar, 1821; Microhyus setiger LeConte, 1876; Microplontus campestris (Gyllenhal, 1837; Orchestes alni (Linnaeus, 1758; Otiorhynchus ligustici (Linnaeus, 1758; Rhinusa neta (Germar, 1821; Trichobaris trinotata (Say, 1832; Tychius liljebladi Blatchley, 1916; Xyleborinus attenuatus (Blandford, 1894; Xyleborus affinis Eichhoff, 1868 (all Curculionidae; Sphenophorus incongruus Chittenden, 1905 (Dryophthoridae; New Brunswick – Euparius paganus Gyllenhal, 1833; Allandrus populi Pierce, 1930; Gonotropis dorsalis (Thunberg, 1796; Euxenus punctatus LeConte, 1876 (all Anthribidae; Loborhynchapion cyanitinctum (Fall, 1927 (Brentidae; Pseudanthonomus seriesetosus Dietz, 1891; Curculio sulcatulus (Casey, 1897; Lignyodes bischoffi (Blatchley, 1916; Lignyodes horridulus (Casey, 1892; Dietzella zimmermanni (Gyllenhal, 1837; Parenthis vestitus Dietz, 1896; Pelenomus squamosus LeConte, 1876; Psomus armatus Dietz, 1891; Rhyncolus macrops Buchanan, 1946; Magdalis

  8. New Curculionoidea (Coleoptera) records for Canada.

    Science.gov (United States)

    Douglas, Hume; Bouchard, Patrice; Anderson, Robert S; de Tonnancour, Pierre; Vigneault, Robert; Webster, Reginald P

    2013-01-01

    Semenov Tjan-Shansky, 1902; Tyloderma foveolatum (Say, 1832); (all Curculionidae); Ontario - Trichapion nigrum (Herbst, 1797); Nanophyes marmoratus marmoratus (Goeze, 1777) (both Brentidae); Asperosoma echinatum (Fall, 1917); Micracis suturalis LeConte, 1868; Orchestes alni (Linnaeus, 1758); Phloeosinus pini Swaine, 1915; Scolytus schevyrewi Semenov Tjan-Shansky, 1902; Xyleborinus attenuatus (Blandford, 1894) (all Curculionidae); Quebec - Trigonorhinus alternatus (Say, 1826); Trigonorhinus tomentosus tomentosus (Say, 1826) (both Anthribidae); Trichapion nigrum (Herbst, 1797); Trichapion porcatum (Boheman, 1839); Nanophyes marmoratus marmoratus (Goeze, 1777) (all Brentidae); Lissorhoptrus oryzophilus Kuschel, 1952 (Brachyceridae); Acalles carinatus LeConte, 1876; Ampeloglypter ampelopsis (Riley, 1869); Anthonomus rufipes LeConte, 1876; Anthonomus suturalis LeConte, 1824; Ceutorhynchus hamiltoni Dietz, 1896; Curculio pardalis (Chittenden, 1908); Cyrtepistomus castaneus (Roelofs, 1873); Larinus planus (Fabricius, 1792); Mecinus janthinus (Germar, 1821); Microhyus setiger LeConte, 1876; Microplontus campestris (Gyllenhal, 1837); Orchestes alni (Linnaeus, 1758); Otiorhynchus ligustici (Linnaeus, 1758); Rhinusa neta (Germar, 1821); Trichobaris trinotata (Say, 1832); Tychius liljebladi Blatchley, 1916; Xyleborinus attenuatus (Blandford, 1894); Xyleborus affinis Eichhoff, 1868 (all Curculionidae); Sphenophorus incongruus Chittenden, 1905 (Dryophthoridae); New Brunswick - Euparius paganus Gyllenhal, 1833; Allandrus populi Pierce, 1930; Gonotropis dorsalis (Thunberg, 1796); Euxenus punctatus LeConte, 1876 (all Anthribidae); Loborhynchapion cyanitinctum (Fall, 1927) (Brentidae); Pseudanthonomus seriesetosus Dietz, 1891; Curculio sulcatulus (Casey, 1897); Lignyodes bischoffi (Blatchley, 1916); Lignyodes horridulus (Casey, 1892); Dietzella zimmermanni (Gyllenhal, 1837); Parenthis vestitus Dietz, 1896; Pelenomus squamosus LeConte, 1876; Psomus armatus Dietz, 1891; Rhyncolus macrops

  9. Diet of Lontra longicaudis (Olfers, 1818 (Carnivora: Mustelidae in three limnic systems in Southern Rio Grande do Sul State, Brazil

    Directory of Open Access Journals (Sweden)

    Fernando Marques Quintela

    2012-12-01

    Full Text Available The aim of the present work was to study the diet of Lontra longicaudis in three limnic systems (anthropogenic shallow lakes, pluvial channel and coastal stream in Rio Grande do Sul State coastal plain, southern Brazil. Fishes were the most consumed item in all the three systems, being Mugilidae the most representative family in the pluvial channel and coastal stream and Cichlidae in the shallow lakes. Other identified items were mollusks, insects, crustaceans, amphibians, reptiles, birds and mammals and vegetal fragments. The high frequency of birds in the shallow lakes was remarkable, considering the lower frequencies of this item in previous investigations on the species diet. There was a high frequency of swamp eels (Synbranchidae, Synbranchus marmoratus in the pluvial channel and shallow lakes, which were usually absent or found in low frequencies in previous studies.

  10. Patrones de abundancia, composición trófica y distribución espacial del ensamble de peces intermareales de la zona centro-sur de Chile Abundance, trophic composition and spatial distribution of the intertidal fish assemblage of South-central Chile

    Directory of Open Access Journals (Sweden)

    PABLO A QUIJADA

    2000-12-01

    Full Text Available En las costas de la zona centro-sur de Chile se han realizado una serie de estudios relacionados con la biología de los peces pelágicos de importancia económica. Por el contrario, el conocimiento acerca de los peces litorales es escaso. En el presente trabajo, se estudiaron los patrones de abundancia, distribución y composición trófica del ensamble de peces que habitan en el intermareal rocoso de la costa de la Octava Región. Esta zona fue muestreada periódicamente entre septiembre de 1998 y enero de 1999. Se capturaron un total de 374 individuos pertenecientes a 13 especies y 8 familias. La especie más abundante en esta zona fue el pejesapo Gobiesox marmoratus (Gobiesocidae seguido de Calliclinus geniguttatus (Labrisomidae, las que en conjunto aportaron el 54 % al número total de peces encontrados. Las restantes especies pertenecieron a las familias Blenniidae, Labrisomidae, Clinidae, Bovichthydae, Tripterygiidae, Ophiididae y Nototheniidae. La presencia de ejemplares en estado juvenil, principalmente de G. marmoratus, indica que estas áreas son muy importantes como zonas de reclutamiento. El análisis trófico indica que este ensamble se compone en su mayoría de especies carnívoras que se alimentan principalmente de crustáceos y gastrópodos, con la excepción de los blénidos Scartichthys viridis, el cual es herbívoro, e Hypsoblennius sordidus que presenta una dieta de tipo omnívoraOn the coast of South-central Chile, a number of studies have been undertaken focusing on the biology of economically important pelagic fishes. In contrast, the knowledge of coastal fishes is scarce. In the present study, we analysed the patterns of abundance, distribution and trophic composition of the intertidal fish assemblage that inhabits rocky intertidal areas along the coast of the Eighth Region. This zone was sampled periodically between September 1998, and January 1999. A total of 374 individuals belonging to 13 species and 8 families were

  11. Diversidad y microestructura de quitones (Mollusca: Polyplacophora del Caribe de Costa Rica

    Directory of Open Access Journals (Sweden)

    Cedar I García-Ríos

    2011-03-01

    Full Text Available Los poliplacóforos asociados a los arrecifes de coral en la costa caribeña de Costa Rica han sido poco estudiados. El examen del cascajo de coral acumulado en el sublitoral somero, en cuatro estaciones de colección, localizadas en la Provincia de Limón reveló una diversidad de quitones mayor a la documentada. Anteriormente se habían registrado ocho especies para el Caribe costaricense: Ischnochiton erythronotus (C.B. Adams, 1845; Ischnoplax pectinata (Sowerby 1840; Stenoplax boogii (Haddon, 1886; S. purpurascens (C.B. Adams, 1845; Acanthopleura granulata (Gmelin, 1791; Chiton marmoratus Gmelin, 1791; C. tuberculatus Linnaeus, 1758; Acanthochitona rhodea (Pilsbry, 1893. Otras cinco se registran aquí por primera vez: Callistochiton portobelensis Ferreira 1976; Ischnochiton kaasi Ferreira 1987; I. pseudovirgatus Kaas 1972; Acanthochitona balesae Abbott 1954; Cryptoconchus floridanus (Dall 1889.Diversity and microstructure of quitons (Mollusca: Polyplacophora from the Caribbean of Costa Rica. The polyplacophorans of the coral reef on the Caribbean coast of Costa Rica have been insufficiently studied. The examination of coral rubble accumulated in the shallow sublitoral waters on four collection stations in Provincia Limón revealed a higher diversity of chitons than was documented. From the country eight species were previously known: Ischnochiton erythronotus (C.B. Adams 1845; Ischnoplax pectinata (Sowerby 1840; Stenoplax boogii (Haddon 1886; S. purpurascens (C.B. Adams 1845; Acanthopleura granulate (Gmelin 1791; Chiton marmoratus Gmelin 1791; C. tuberculatus Linnaeus 1758 and Acanthochitona rhodea (Pilsbry 1893. This study added five more species that are reported here for the first time: Callistochiton portobelensis Ferreira 1976; Ischnochiton kaasi Ferreira 1987; I. pseudovirgatus Kaas 1972; Acanthochitona balesae Abbott 1954 and Cryptoconchus floridanus (Dall 1889. Rev. Biol. Trop. 59 (1: 129-136. Epub 2011 March 01.

  12. Biology and ecomorphology of stream fishes from the rio Mogi-Guaçu basin, Southeastern Brazil

    Directory of Open Access Journals (Sweden)

    Katiane M. Ferreira

    Full Text Available The córrego Paulicéia is a direct tributary of the rio Mogi-Guaçu, located in Santa Rita do Passa Quatro, State of São Paulo, Southeastern Brazil. This stream runs inside a savannah-like (cerrado environment and it associated vegetation. Biological and ecomorphological aspects of its fish community were studied in three stretches of the stream, denominated herein as the upper, middle and lower courses. The fish fauna recorded in this study consisted of 15 species, belonging to five orders and nine families, based in a total of 715 collected individuals representing 1,450 kg of biomass. The most important abiotic factors related to the occurrence and distribution of the fish fauna were the substrate, current speed, and presence or absence of riparian vegetation. The analysis of 336 stomach contents of 13 species demonstrated that 65% of food items are autochthonous, 32% allochthonous, and 3% are of unknown origin. Four alimentary guilds could be identified, based on the predominant food items: omnivores with tendency to insectivory - Astyanax paranae, A. fasciatus and Piabina argentea; larvivores - Corydoras difluviatilis, Cetopsorhamdia iheringi, Phenacorhamdia tenebrosa, Characidium gomesi, Eigenmannia virescens, and Rhamdia quelen; periphyton feeders - Hisonotus sp., Hypostomus ancistroides and Synbranchus marmoratus; and piscivore - Hoplias malabaricus. Reproductions data are presented for Astyanax altiparanae and Hisontus sp. Three ecomorphological groups could be established, based on swimming, feeding, and microhabitat strategies: nektonic (A. fasciatus, A. paranae, Bryconamericus stramineus, P. argentea, H. malabaricus and Phallotorynus jucundus, benthic (C. gomesi, P. tenebrosa, C. iheringi, R. quelen, C. difluviatilis, H. ancistroides and Hisonotus sp., and necktobenthic (E. virescens and S. marmoratus.

  13. Intra-generic and interspecific karyotype patterns of Leptodactylus and Adenomera (Anura, Leptodactylidae) with inclusion of five species from Central Amazonia.

    Science.gov (United States)

    Coelho, Ana Carolina; de Mattos, Thais Lemos; Viana, Patrik; Terencio, Maria Leandra; Schneider, Carlos Henrique; Menin, Marcelo; Gross, Maria Claudia

    2016-02-01

    The genera Leptodactylus and Adenomera comprise 92 species distributed throughout the Neotropical region. These species have a modal diploid chromosome number 2n = 22. However, chromosome rearrangements are evident in the differentiation of five intra-generic groups in the genus Leptodactylus (L. fuscus, L. latrans, L. marmoratus (formally composed by the species of the genus Adenomera), L. melanonotus, L. pentadactylus), yet it is not clear if there is a karyotype pattern for each group. Aiming to understand the intra-generic and interspecific karyotype patterns of Leptodactylus and Adenomera, cytogenetic analyses were performed in A. andreae, L. macrosternum, L. pentadactylus, L. petersii, and L. riveroi using conventional staining, C-banding, nucleolus organizer region (NOR) and hybridization in situ fluorescent (FISH). The karyotype of Leptodactylus riveroi was described for the first time. Adenomera andreae had 2n = 26, while the remaining species 2n = 22. The NOR was found on pair No. 8 of A. andreae, L. macrosternum, L. pentadactylus, and L. riveroi, whereas L. petersii had it on pairs Nos. 6 and 10. These locations were confirmed by the FISH with 18S rDNA probe, except for pair No. 10 of L. petersii. The C-banding pattern was evident at the centromeres of chromosomes of all species and some interspecific variations were also observed. 2n = 22 was observed in the species of the L. latrans group, as well as in the intra-generic groups L. fuscus and L. pentadactylus; in the L. melanonotus group there were three diploid chromosome numbers 2n = 20, 22 and 24; and a larger variation in 2n was also evident in the L. marmoratus group.

  14. Long-term monitoring of tropical alpine habitat change, Andean anurans, and chytrid fungus in the Cordillera Vilcanota, Peru: Results from a decade of study.

    Science.gov (United States)

    Seimon, Tracie A; Seimon, Anton; Yager, Karina; Reider, Kelsey; Delgado, Amanda; Sowell, Preston; Tupayachi, Alfredo; Konecky, Bronwen; McAloose, Denise; Halloy, Stephan

    2017-03-01

    The Cordillera Vilcanota in southern Peru is the second largest glacierized range in the tropics and home to one of the largest high-alpine lakes, Sibinacocha (4,860 m). Here, Telmatobius marmoratus (marbled water frog), Rhinella spinulosa (Andean toad), and Pleurodema marmoratum (marbled four-eyed frog) have expanded their range vertically within the past century to inhabit newly formed ponds created by ongoing deglaciation. These anuran populations, geographically among the highest (5,200-5,400 m) recorded globally, are being impacted by the chytrid fungus Batrachochytrium dendrobatidis ( Bd ), and the disease it causes, chytridiomycosis. In this study, we report results from over a decade of monitoring these three anuran species, their habitat, and Bd infection status. Our observations reveal dynamic changes in habitat including ongoing rapid deglaciation (18.4 m/year widening of a corridor between retreating glaciers from 2005 to 2015), new pond formation, changes in vegetation in amphibian habitat, and widespread occurrence of Bd in amphibians in seven sites. Three of these sites have tested positive for Bd over a 9- to 12-year period. In addition, we observed a widespread reduction in T. marmoratus encounters in the Vilcanota in 2008, 2009, and 2012, while encounters increased in 2013 and 2015. Despite the rapid and dynamic changes in habitat under a warming climate, continued presence of Bd in the environment for over a decade, and a reduction in one of three anuran species, we document that these anurans continue to breed and survive in this high Andean environment. High variability in anuran encounters across sites and plasticity in these populations across habitats, sites, and years are all factors that could favor repopulation postdecline. Preserving the connectivity of wetlands in the Cordillera Vilcanota is therefore essential in ensuring that anurans continue to breed and adapt as climate change continues to reshape the environment.

  15. Los peces Gobiidae de los arrecifes del Caribe Colombiano. IV. el género Lythrypnus Los peces Gobiidae de los arrecifes del Caribe Colombiano. IV. el género Lythrypnus

    Directory of Open Access Journals (Sweden)

    Garzón Ferreira Jaime

    1992-09-01

    Full Text Available Descriptive and ecological information about seven species of the genus Lythrypnus (Pisces: Gobiidae, based on collections done in six coralline areas along the Colombian Caribbean to 50 m deep, is included; a key to aid in species identification is provided. Two of the species turned out to be new for science: the pigmy goby L. minimus, recently descrited and common only at Rosario and San Bernardo islands, was collected between 1 and 20 m and may be the smallest known vertebrate; Lythrypnus sp., usually misidentified as L. crocodilus and soon to be named, was found between 3 and 18 m and is common at several Caribbean localities (but absent from Rosario and San Bernardo islands. The bluegold goby L. spilus was the most frequent in all the Colombian Caribbean (32% of the samples and was collected between 4 and 40 m; the okapi goby L. okapia was registered for a sole specimen got at the Santa Marta region at 7 m. The island goby L. nesiotes inhabits coralline bottoms over 10 m and was the only species collected also in turbid waters without corals; on the other hand, the dwarf goby L. elasson appears only below 10-40 m deep and was the second species in frequency (26%. The disphasic goby L. heterochroma is another rare form; it was collected in Rosario and Providencia islands between 4 and 8 m. Bahía de Portete was the only explored area where no Lythrypnus species has been found. Se incluye información descriptiva y ecológica de siete especies del género Lythrypnus (Pisces: Gobiidae, con base en colecciones realizadas en seis áreas coralinas a lo largo del Caribe Colombiano, hasta 50 m de profundidad. Se presenta además una clave para identificar dichas especies, de las cuales dos resultaron nuevas para la ciencia: L. minimus, descrita recientemente y común sólo en el sector de las Islas del Rosario y de San Bernardo, se colectó entre 1 y 20 m y es tal vez el vertebrado más pequeño del mundo; y Lythrypnus sp., que ha sido confundida

  16. The latest geodynamics in Asia: Synthesis of data on volcanic evolution, lithosphere motion, and mantle velocities in the Baikal-Mongolian region

    Directory of Open Access Journals (Sweden)

    Sergei Rasskazov

    2017-07-01

    Full Text Available From a synthesis of data on volcanic evolution, movement of the lithosphere, and mantle velocities in the Baikal-Mongolian region, we propose a comprehensive model for deep dynamics of Asia that assumes an important role of the Gobi, Baikal, and North Transbaikal transition-layer melting anomalies. This layer was distorted by lower-mantle fluxes at the beginning of the latest geodynamic stage (i.e. in the early late Cretaceous due to avalanches of slab material that were stagnated beneath the closed fragments of the Solonker, Ural-Mongolian paleoceans and Mongol-Okhotsk Gulf of Paleo-Pacific. At the latest geodynamic stage, Asia was involved in east–southeast movement, and the Pacific plate moved in the opposite direction with subduction under Asia. The weakened upper mantle region of the Gobi melting anomaly provided a counterflow connected with rollback in the Japan Sea area. These dynamics resulted in the formation of the Honshu-Korea flexure of the Pacific slab. A similar weakened upper mantle region of the North Transbaikal melting anomaly was associated with the formation of the Hokkaido-Amur flexure of the Pacific slab, formed due to progressive pull-down of the slab material into the transition layer in the direction of the Pacific plate and Asia convergence. The early–middle Miocene structural reorganization of the mantle processes in Asia resulted in the development of upper mantle low-velocity domains associated with the development of rifts and orogens. We propose that extension at the Baikal Rift was caused by deviator flowing mantle material, initiated under the moving lithosphere in the Baikal melting anomaly. Contraction at the Hangay orogen was created by facilitation of the tectonic stress transfer from the Indo-Asian interaction zone due to the low-viscosity mantle in the Gobi melting anomaly.

  17. Repeated invasions into the twilight zone: evolutionary origins of a novel assemblage of fishes from deep Caribbean reefs.

    Science.gov (United States)

    Tornabene, Luke; Van Tassell, James L; Robertson, D Ross; Baldwin, Carole C

    2016-08-01

    Mesophotic and deeper reefs of the tropics are poorly known and underexplored ecosystems worldwide. Collectively referred to as the 'twilight zone', depths below ~30-50 m are home to many species of reef fishes that are absent from shallower depths, including many undescribed and endemic species. We currently lack even a basic understanding of the diversity and evolutionary origins of fishes on tropical mesophotic reefs. Recent submersible collections in the Caribbean have provided new specimens that are enabling phylogenetic reconstructions that incorporate deep-reef representatives of tropical fish genera. Here, we investigate evolutionary depth transitions in the family Gobiidae (gobies), the most diverse group of tropical marine fishes. Using divergence-time estimation coupled with stochastic character mapping to infer the timing of shallow-to-deep habitat transitions in gobies, we demonstrate at least four transitions from shallow to mesophotic depths. Habitat transitions occurred in two broad time periods (Miocene, Pliocene-Pleistocene), and may have been linked to the availability of underutilized niches, as well as the evolution of morphological/behavioural adaptations for life on deep reefs. Further, our analysis shows that at least three evolutionary lineages that invaded deep habitats subsequently underwent speciation, reflecting another unique mode of radiation within the Gobiidae. Lastly, we synthesize depth distributions for 95 species of Caribbean gobies, which reveal major bathymetric faunal breaks at the boundary between euphotic and mesophotic reefs. Ultimately, our study is the first rigorous investigation into the origin of Caribbean deep-reef fishes and provides a framework for future studies that utilize rare, deep-reef specimens. © 2016 John Wiley & Sons Ltd.

  18. Effect of sub-lethal exposure to ultraviolet radiation on the escape performance of Atlantic cod larvae (Gadus morhua.

    Directory of Open Access Journals (Sweden)

    Yuichi Fukunishi

    Full Text Available The amount of ultraviolet (UV radiation reaching the earth's surface has increased due to depletion of the ozone layer. Several studies have reported that UV radiation reduces survival of fish larvae. However, indirect and sub-lethal impacts of UV radiation on fish behavior have been given little consideration. We observed the escape performance of larval cod (24 dph, SL: 7.6±0.2 mm; 29 dph, SL: 8.2±0.3 mm that had been exposed to sub-lethal levels of UV radiation vs. unexposed controls. Two predators were used (in separate experiments: two-spotted goby (Gobiusculus flavescens; a suction predator and lion's mane jellyfish (Cyanea capillata; a "passive" ambush predator. Ten cod larvae were observed in the presence of a predator for 20 minutes using a digital video camera. Trials were replicated 4 times for goby and 5 times for jellyfish. Escape rate (total number of escapes/total number of attacks ×100, escape distance and the number of larvae remaining at the end of the experiment were measured. In the experiment with gobies, in the UV-treated larvae, both escape rate and escape distance (36%, 38±7.5 mm respectively were significantly lower than those of control larvae (75%, 69±4.7 mm respectively. There was a significant difference in survival as well (UV: 35%,63%. No apparent escape response was observed, and survival rate was not significantly different, between treatments (UV: 66%,74% in the experiment with jellyfish. We conclude that the effect and impact of exposure to sub-lethal levels of UV radiation on the escape performance of cod larvae depends on the type of predator. Our results also suggest that prediction of UV impacts on fish larvae based only on direct effects are underestimations.

  19. Trans-pacific dust transport: integrated analysis of NASA/CALIPSO and a global aerosol transport model

    Directory of Open Access Journals (Sweden)

    K. Eguchi

    2009-05-01

    Full Text Available Detailed 3-D structures of Trans-Pacific Asian dust transport occurring during 5–15 May 2007 were investigated using the NASA/CALIOP vertical-resolved measurements and a three-dimensional aerosol model (SPRINTARS. Both CALIOP and SPRINTARS dust extinctions showed a good agreement along the way of the transport from the dust source regions across North Pacific into North America. A vertically two-layered dust distribution was observed over the northeastern Pacific and North America. The lower dust layer originated from a dust storm generated in the Gobi Desert on 5 May. It was transported at an altitude of around 4 km MSL and has mixed with Asian anthropogenic air pollutants during the course of transport. The upper dust layer mainly originated from a dust storm that occurred in the Taklimakan Desert 2–3 days after the Gobi dust storm generation. The upper dust cloud was transported in higher altitudes above the major clouds layer during the Trans-Pacific transport. It therefore has remained unmixed with the Asian air pollutants and almost unaffected by wet removal. The decay of its concentration level was small (only one-half after its long-distance transport crossing the Pacific. Our dust budget analysis revealed that the Asian dust flux passing through the longitude plane of 140° E was 2.1 Tg, and one third of that arrived North America. The cases analyzed in this study revealed that, while the Gobi Desert is an important source that can contribute to the long-range dust transport, the Taklimakan Desert appears to be another important source that can contribute to the dust transport occurring particularly at high altitudes.

  20. Evolution of microhabitat association and morphology in a diverse group of cryptobenthic coral reef fishes (Teleostei: Gobiidae: Eviota)

    KAUST Repository

    Tornabene, Luke

    2013-01-01

    Gobies (Teleostei: Gobiidae) are an extremely diverse and widely distributed group and are the second most species rich family of vertebrates. Ecological drivers are key to the evolutionary success of the Gobiidae. However, ecological and phylogenetic data are lacking for many diverse genera of gobies. Our study investigated the evolution of microhabitat association across the phylogeny of 18 species of dwarfgobies (genus Eviota), an abundant and diverse group of coral reef fishes. In addition, we also explore the evolution of pectoral fin-ray branching and sensory head pores to determine the relationship between morphological evolution and microhabitat shifts. Our results demonstrate that Eviota species switched multiple times from a facultative hard-coral association to inhabiting rubble or mixed sand/rubble habitat. We found no obvious relationship between microhabitat shifts and changes in pectoral fin-ray branching or reduction in sensory pores, with the latter character being highly homoplasious throughout the genus. The relative flexibility in coral-association in Eviota combined with the ability to move into non-coral habitats suggests a genetic capacity for ecological release in contrast to the strict obligate coral-dwelling relationship commonly observed in closely related coral gobies, thus promoting co-existence through fine scale niche partitioning. The variation in microhabitat association may facilitate opportunistic ecological speciation, and species persistence in the face of environmental change. This increased speciation opportunity, in concert with a high resilience to extinction, may explain the exceptionally high diversity seen in Eviota compared to related genera in the family. © 2012 Elsevier Inc.

  1. The basic features of clay rock in Tamusu area

    International Nuclear Information System (INIS)

    Liu Xiaodong; Liu Pinghui

    2012-01-01

    This paper introduces the Tamusu area location, natural and social economic situation, the regional geological background, as well as the upper Gobi formation of clay rocks, and from the geological conditions, economic conditions, social conditions and other aspects of the Tamusu claystone conducted a preliminary evaluation. The results showed that this area can be used as one of the favorable preselected areas for high-level radioactive waste geological disposal repository, basically meets the siting criteria for geological conditions, environmental protection, land use, social influence and waste transport etc. (authors)

  2. Análisis del transporte de carga en Colombia, para crear estrategias que permitan alcanzar estándares de competitividad e infraestructura internacional

    OpenAIRE

    Rodriguez Rosas, CarlosMario

    2013-01-01

    El sector transporte juega un papel importante en la consolidación de los procesos de globalización y de competitividad en Colombia. La globalización de las economías es una realidad que exige de los países un esfuerzo para optimizar sus procesos productivos, siendo la disponibilidad y accesibilidad de los bienes una condición necesaria para lograr una mayor competitividad en el contexto internacional. Teniendo en cuenta que una de las principales estrategias de internacionalización del gobie...

  3. Evaluating dispersal potential of an invasive fish by the use of aerobic scope and osmoregulation capacity

    DEFF Research Database (Denmark)

    Behrens, Jane W.; Deurs, Mikael van; Christensen, Emil Aputsiaq Flindt

    2017-01-01

    factors such as presence of predators, competitors, and parasites. Early prediction of dispersal potential and future 'area of impact' is challenging, but also a great asset in taking appropriate management actions. Aerobic scope (AS) in fish has been linked to various fitness-related parameters, and may...... waters is unknown to date. We show that AS in round goby is reduced by 30% and blood plasma osmolality increased (indicating reduced capacity for osmoregulation) at salinities approaching oceanic conditions, following slow ramping (5 PSU per week) and subsequent long-term acclimation to salinities...

  4. 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

    The Skagerrak and Kattegat are estuarine straits of high hydrographical and ecological diversity, situated between the saline waters of the North Sea and the brackish waters of the Baltic Sea. These sustain important nursery grounds of many fish species, of which several overwinter during...... 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...

  5. Deep Learning Methods for Quantifying Invasive Benthic Species in the Great Lakes

    Science.gov (United States)

    Billings, G.; Skinner, K.; Johnson-Roberson, M.

    2017-12-01

    In recent decades, invasive species such as the round goby and dreissenid mussels have greatly impacted the Great Lakes ecosystem. It is critical to monitor these species, model their distribution, and quantify the impacts on the native fisheries and surrounding ecosystem in order to develop an effective management response. However, data collection in underwater environments is challenging and expensive. Furthermore, the round goby is typically found in rocky habitats, which are inaccessible to standard survey techniques such as bottom trawling. In this work we propose a robotic system for visual data collection to automatically detect and quantify invasive round gobies and mussels in the Great Lakes. Robotic platforms equipped with cameras can perform efficient, cost-effective, low-bias benthic surveys. This data collection can be further optimized through automatic detection and annotation of the target species. Deep learning methods have shown success in image recognition tasks. However, these methods often rely on a labelled training dataset, with up to millions of labelled images. Hand labeling large numbers of images is expensive and often impracticable. Furthermore, data collected in the field may be sparse when only considering images that contain the objects of interest. It is easier to collect dense, clean data in controlled lab settings, but this data is not a realistic representation of real field environments. In this work, we propose a deep learning approach to generate a large set of labelled training data realistic of underwater environments in the field. To generate these images, first we draw random sample images of individual fish and mussels from a library of images captured in a controlled lab environment. Next, these randomly drawn samples will be automatically merged into natural background images. Finally, we will use a generative adversarial network (GAN) that incorporates constraints of the physical model of underwater light propagation

  6. Regional Sr-Nd isotopic ratios of soil minerals in northern China as Asian dust fingerprints

    Science.gov (United States)

    Nakano, Takanori; Yokoo, Yoriko; Nishikawa, Masataka; Koyanagi, Hideaki

    We report that arid soils in various areas of northern China can be distinguished by using Sr-Nd isotopic ratios of acid-resistant minerals and Sr isotopic ratios of water- and weak-acid-soluble minerals. Our results show that contemporary dust falling on Beijing is transported mainly from the adjacent northwestern to western areas and is more likely to be related to desertification than dust from the remote Takla Makan desert, the southwestern Gobi desert, or the Loess Plateau. Mineral isotope fingerprinting of arid soils is a powerful tool for source identification and impact assessment of mineral dust, and can serve as a desertification index.

  7. Novel acsF Gene Primers Revealed a Diverse Phototrophic Bacterial Population, Including Gemmatimonadetes, in Lake Taihu (China)

    DEFF Research Database (Denmark)

    Huang, Yili; Zeng, Yanhua; Lu, Hang

    2016-01-01

    phylum, Gemmatimonadetes, was isolated from a freshwater lake in the Gobi Desert. To obtain more information about the environmental distribution of phototrophic Gemmatimonadetes, we collected microbial samples from the water column, upper sediment, and deeper anoxic sediment of Lake Taihu, China. Mi...... fundamental biological processes on Earth. Recently, the presence of photosynthetic reaction centers has been reported from a rarely studied bacterial phylum, Gemmatimonadetes, but almost nothing is known about the diversity and environmental distribution of these organisms. The newly designed acsF primers...

  8. Phototrophic gemmatimonadetes

    DEFF Research Database (Denmark)

    Zeng, Yonghui; Koblížek, Michal

    2017-01-01

    Photosynthesis first emerged in prokaryotes over three billion years ago and represents one of the most fundamental biological processes on Earth. So far, species capable of performing (bacterio)chlorophyll-based phototrophy have been reported in seven bacterial phyla, i.e., Cyanobacteria...... of the phylum Gemmatimonadetes. This organism was isolated from a freshwater lake in the Gobi Desert, North China in 2011. It contains fully functional type-2 photosynthetic reaction centers, but they seem to only serve as an auxiliary energy source. Its photosynthesis genes are located in a 42.3 kb long...

  9. Integrated trend assessment of ecosystem changes in the Limfjord (Denmark): evidence of a recent regime shift?

    DEFF Research Database (Denmark)

    Tomczak, Maciej Tomasz; Dinesen, Grete E.; Hoffmann, Erik

    2012-01-01

    and main outflow to the Kattegat in the east. We showed that from 1990 to 1995, the ecosystem structure shifted from dominance by demersal fish species (eel pout, whiting, flounder, plaice) to that of pelagic fish species (sprat, herring, sticklebacks), smallbodied fish species (black goby, pipefish......), jellyfish, common shore crab, starfish and blue mussels. We interpret this change as a regime shift that showed a similar temporal pattern to regime shifts identified in adjacent seas. The observed changes in trophic interactions and food web reorganisation suggested a non-linear regime shift. The analyses...

  10. A theropod dinosaur embryo and the affinities of the flaming cliffs dinosaur eggs.

    Science.gov (United States)

    Norell, M A; Clark, J M; Demberelyin, D; Rhinchen, B; Chiappe, L M; Davidson, A R; McKenna, M C; Altangerel, P; Novacek, M J

    1994-11-04

    An embryonic skeleton of a nonavian theropod dinosaur was found preserved in an egg from Upper Cretaceous rocks in the Gobi Desert of Mongolia. Cranial features identify the embryo as a member of Oviraptoridae. Two embryo-sized skulls of dromaeosaurids, similar to that of Velociraptor, were also recovered in the nest. The eggshell microstructure is similar to that of ratite birds and is of a type common in the Djadokhta Formation at the Flaming Cliffs (Bayn Dzak). Discovery of a nest of such eggs at the Flaming Cliffs in 1923, beneath the Oviraptor philoceratops holotype, suggests that this dinosaur may have been a brooding adult.

  11. The diet of whiting Merlangius merlangus in the western Baltic Sea

    DEFF Research Database (Denmark)

    Ross, Stine Dalmann; Gislason, Henrik; Andersen, Niels Gerner

    2016-01-01

    The diet of whiting Merlangius merlangus in the western Baltic Sea was investigated and compared to the diet in the southern North Sea. Clupeids were important prey in both areas, but especially in the western Baltic Sea where they constituted up to 90% of the diet of larger individuals. Gobies...... North Sea. Estimates of prey abundance and food intake of M. merlangus are required to evaluate its predatory significance in the western Baltic Sea, but its diet suggests that it could be just as significant a fish predator here as in the southern North Sea...

  12. China radiometric calibration sites ground-based automatic observing systems for CAL/VAL

    Science.gov (United States)

    Zhang, Yong; Li, Xin; Rong, Zhiguo; Zhang, Lijun; Hu, Xiuqing; Ba, Xiutian

    2015-10-01

    A brand-new field observing station has been built up in the China radiometric calibration sites (CRCS) of Dunhuang Gobi for CAL/VAL, include house, observing field, power supply, tower crane, et al. Many automatic observation instruments designed and manufactured by Anhui Institute of Optics and Fine Mechanical Chinese Academy of Sciences were deployed in CRCS Dunhuang Site and introduced deeply in this paper. Followed with the finishing of the basic constructions of the field observing station, it will be an open field test and exchange platform for sharing of test data, research and infrastructure, promote exchanges and cooperation between the relevant disciplines and units.

  13. Assessing food web dynamics and relative importance of organic matter sources for fish species in two Portuguese estuaries: a stable isotope approach.

    Science.gov (United States)

    França, Susana; Vasconcelos, Rita P; Tanner, Susanne; Máguas, Cristina; Costa, Maria José; Cabral, Henrique N

    2011-10-01

    Stable carbon and nitrogen isotopes (δ¹³C, δ¹⁵N) were used to analyse food web dynamics of two of the main estuaries of the Portuguese coast: Tejo and Mira. The ultimate sources of organic matter supporting production of some of the most abundant and commercially important fish species were determined; and seasonal, inter- and intra- estuarine differences in the trophic relations among producers and consumers were identified. Stable isotope analysis was performed in different producers, primary consumers (main prey items for fish) and fish species (Solea solea, Solea senegalensis, Pomatoschistus microps, Dicentrarchus labrax, Liza ramada, Diplodus vulgaris and Atherina presbyter) of two areas in each estuary, in July and October 2009. Model calculations showed that the main prey for the fish species in the Tejo estuary used mostly salt marsh-derived organic matter as nutritional sources, with no marked differences between the sampled months. Trophic levels of fish species from the same estuary differed at multiple scales: inter-species, seasonally and spatially (both between and within estuaries). Significant differences in isotopic composition of fish species were more pronounced spatially (between the two sampled areas in the estuary) than seasonally (between sampled months). Trophic relationships in both estuaries demonstrated that organic matter is transferred to higher trophic positions mainly through benthic pathways. This shows the flexibility of these species to share resources and to exploit temporary peaks in prey populations. The present results showed that extensive disturbance in intertidal habitats from both estuaries may potentially change the balance of organic matter in the base of these complex food webs. Copyright © 2011 Elsevier Ltd. All rights reserved.

  14. Biomarker responses to environmental contamination in estuaries: A comparative multi-taxa approach.

    Science.gov (United States)

    Duarte, Irina A; Reis-Santos, Patrick; França, Susana; Cabral, Henrique; Fonseca, Vanessa F

    2017-08-01

    Estuaries are highly productive ecosystems subjected to numerous anthropogenic pressures with consequent environmental quality degradation. In this study, multiple biomarker responses [superoxide dismutase (SOD), catalase (CAT), ethoxyresorufin O-deethylase (EROD) and glutathione S-transferase (GST) activities, as well as lipid peroxidation (LPO) and DNA damage (DNAd)] were determined in two fish (Dicentrarchus labrax and Pomatoschistus microps) and four macroinvertebrate species (Carcinus maenas, Crangon crangon, Hediste diversicolor and Scrobicularia plana) from the Ria de Aveiro and Tejo estuaries over distinct months. Two sites per estuarine system were selected based on anthropogenic pressures and magnitude of environmental contamination. Antioxidant enzyme activities in fish species suggested a ubiquitous response to oxidative stress, while biotransformation and effect biomarkers exhibited higher spatial and temporal variation. In invertebrate species, biotransformation enzyme activity was clearly less variable than in fish evidencing lower xenobiotic transformation capability. Overall, largest biomarker responses were found in the most contaminated sites (Tejo), yet species-specific patterns were evident. These should be factored in multi-taxa approaches, considering that the differential functional traits of species, such as habitat use, life-stage, feeding or physiology can influence exposure routes and biomarker responses. The Integrated Biomarker Response index highlighted patterns in biomarker responses which were not immediately evident when analyzing biomarkers individually. Overall, results provided insights into the complexity of species responses to contamination in naturally varying estuarine environments. Ultimately, multi-taxa and multi-biomarker approaches provide a comprehensive and complementary view of ecosystem health, encompassing diverse forms of biological integration and exposure routes, and allow the validation of results among markers

  15. A high aggression strategy for smaller males.

    Directory of Open Access Journals (Sweden)

    P Andreas Svensson

    Full Text Available Male-male conflict is common among animals, but questions remain as to when, how and by whom aggression should be initiated. Factors that affect agonistic strategies include residency, the value of the contested resource and the fighting ability of the two contestants. We quantified initiation of aggression in a fish, the desert goby, Chlamydogobius eremius, by exposing nest-holding males to a male intruder. The perceived value of the resource (the nest was manipulated by exposing half of the residents to sexually receptive females for two days before the trial. Resident male aggression, however, was unaffected by perceived mating opportunities. It was also unaffected by the absolute and relative size of the intruder. Instead resident aggression was negatively related to resident male size. In particular, smaller residents attacked sooner and with greater intensity compared to larger residents. These results suggest that resident desert goby males used set, rather than conditional, strategies for initiating aggression. If intruders are more likely to flee than retaliate, small males may benefit from attacking intruders before these have had an opportunity to assess the resident and/or the resource.

  16. Stable isotopes reveal diet shift from pre-extinction to reintroduced Przewalski's horses.

    Science.gov (United States)

    Kaczensky, Petra; Burnik Šturm, Martina; Sablin, Mikhail V; Voigt, Christian C; Smith, Steve; Ganbaatar, Oyunsaikhan; Balint, Boglarka; Walzer, Chris; Spasskaya, Natalia N

    2017-07-20

    The Przewalski's horse (Equus ferus przewalskii), the only remaining wild horse within the equid family, is one of only a handful of species worldwide that went extinct in the wild, was saved by captive breeding, and has been successfully returned to the wild. However, concerns remain that after multiple generations in captivity the ecology of the Przewalski's horse and / or the ecological conditions in its former range have changed in a way compromising the species' long term survival. We analyzed stable isotope chronologies from tail hair of pre-extinction and reintroduced Przewalski's horses from the Dzungarian Gobi and detected a clear difference in the isotopic dietary composition. The direction of the dietary shift from being a mixed feeder in winter and a grazer in summer in the past, to a year-round grazer nowadays, is best explained by a release from human hunting pressure. A changed, positive societal attitude towards the species allows reintroduced Przewalski's horses to utilize the scarce, grass-dominated pastures of the Gobi alongside local people and their livestock whereas their historic conspecifics were forced into less productive habitats dominated by browse.

  17. Assessment of lake sturgeon (Acipenser fulvescens) spawning efforts in the lower St. Clair River, Michigan

    Science.gov (United States)

    Nichols, S. Jerrine; Kennedy, Gregory; Crawford, Eric; Allen, Jeffrey; French, John; Black, Glen; Blouin, Marc; Hickey, James P.; Chernyak, Sergei; Haas, Robert; Thomas, Michael

    2003-01-01

    One of the most threatened remaining populations of lake sturgeon in the Great Lakes is found in the connecting channels between Lake Huron and Lake Erie. Only two spawning grounds are presently known to be active in this region, and both are in the St. Clair River. The spawning reef in the St. Clair River delta has been recently colonized by round gobies (Neogobius melanostomus) in densities up to 25/m2, raising concerns regarding predation on the benthic-oriented eggs and larvae of the sturgeon. Investigations in 1998–1999 showed that while round goby predation does occur, a number of other factors may be equally affecting sturgeon spawning success, including few spawning adults (noted in either year. There were factors other than predation affecting larval survival in 1999. There was a higher silt load on the reef than in 1998 and large numbers of dead larvae were found. Recruitment success from this site could be improved by utilizing techniques to increase the number of eggs on the reef, such as reducing the illegal take of adult fish and by placing eggs in predator-exclusion chambers to increase hatch rate.

  18. Inheritance patterns of morphological laterality in mouth opening of zebrafish, Danio rerio.

    Science.gov (United States)

    Hata, Hiroki; Hori, Michio

    2012-01-01

    The inheritance patterns of asymmetry in mouth opening in zebrafish were investigated using crossing experiments. Zebrafish exhibit asymmetric laterality in mouth opening, with each individual having either a leftward (righty) or rightward (lefty) bias. All righty incrosses produced only righty F(1), whereas all lefty incrosses resulted in an F(1) L:R ratio of 2:1. All test crosses between lefty and righty individuals resulted in an F(1) L:R=1:1. These results were consistent with the hereditary pattern for Japanese medaka, three Tanganyikan cichlids, and a Japanese riverine goby. The pattern suggests a one-locus two-allele Mendelian model of inheritance, with the lefty allele being dominant over righty and the dominant homozygote being lethal. To determine the reason for the absence of lefty homozygotes, the survival rates of the offspring were examined according to developmental stage. Survival did not differ among combinations of parent laterality. Thus the mechanism underlying the lethality of the dominant homozygote remains unclear. This study showed that the mouth-opening laterality of zebrafish is genetically determined and that the direction follows a Mendelian inheritance pattern that is shared among cypriniform zebrafish, beloniform medaka, perciform cichlids, and a goby, suggesting a common genetic background in mouth-opening laterality among these species.

  19. Investigation of Three-Dimensional Evolution of East Asian Dust Storm by Modeling and Remote Sensing Measurements

    Directory of Open Access Journals (Sweden)

    Jiawei Li

    2015-01-01

    Full Text Available The three-dimensional evolution of an East Asian dust storm during 23–26 April 2009 was investigated by utilizing a regional air quality model system (RAQMS and satellite measurements. This severe dust storm hit Mt. Tai in east China with daily mean PM10 concentration reaching 1400 μg/m3 and the model captured the PM10 variation reasonably well. Modeled spatial distributions of AOD and vertical profiles of aerosol extinction coefficient during the dust storm were compared with MODIS and CALIPSO data, demonstrating that RAQMS was able to reproduce the 3D structure and the evolution of the dust storm reasonably well. During early days of the dust storm, daily mean dust-induced AOD exceeded 2.0 over dust source regions (the Gobi desert and the Taklamakan desert and was in a range of 1.2–1.8 over the North China Plain, accounting for about 98% and up to 90% of total AOD over corresponding areas, respectively. The top of the dust storm reached about 8 km over east China, with high dust concentration locating at around 40°N. Dust aerosol below 2 km was transported southeastward off the Gobi desert while dust above 2 km was transported out of China along 40°–45°N.

  20. In vivo and in vitro phenotypic differences between Great Lakes VHSV genotype IVb isolates with sequence types vcG001 and vcG002

    Science.gov (United States)

    Imanse, Sierra M.; Cornwell, Emily R.; Getchell, Rodman G.; Kurath, Gael; Bowser, Paul R.

    2014-01-01

    Viral hemorrhagic septicemia virus (VHSV) is an aquatic rhabdovirus first recognized in farmed rainbow trout in Denmark. In the past decade, a new genotype of this virus, IVb was discovered in the Laurentian Great Lakes basin and has caused several massive die-offs in some of the 28 species of susceptible North American freshwater fishes. Since its colonization of the Great Lakes, several closely related sequence types within genotype IVb have been reported, the two most common of which are vcG001 and vcG002. These sequence types have different spatial distributions in the Great Lakes. The aim of this study was to determine whether the genotypic differences between representative vcG001 (isolate MI03) and vcG002 (isolate 2010-030 #91) isolates correspond to phenotypic differences in terms of virulence using both in vitro and in vivo approaches. In vitro infection of epithelioma papulosum cyprini (EPC), bluegill fry (BF-2), and Chinook salmon embryo (CHSE) cells demonstrated some differences in onset and rate of growth in EPC and BF-2 cells, without any difference in the quantity of RNA produced. In vivo infection of round gobies (Neogobius melanostomus) via immersion exposure to different concentrations of vcG001 or vcG002 caused a significantly greater mortality in round gobies exposed to 102 plaque forming units ml− 1 of vcG001. These experiments suggest that there are phenotypic differences between Great Lakes isolates of VHSV genotype IVb.

  1. Long-term trends in daily temperature extremes over Mongolia

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    Dulamsuren Dashkhuu

    2015-06-01

    Full Text Available Various indices have been used to investigate recent changes in the annual frequencies of extreme temperature events in Mongolia. A high-quality daily temperature dataset including 53 station records was used to determine trends from 1961 to 2010. The Climdex1.0 software was used to calculate 11 extreme temperature indices for this study. The results showed significant changes in important temperature indices over the study period, especially in the Gobi Mongolia. The analysis showed that an apparent increase in summer days was observed, while an appreciable decrease in frost days was observed. The maximum values of daily maximum temperature (TXx and daily minimum temperature (TNx and the minimum values of Tmax (TXn and Tmin (TNn tended to increase. However, for TXx and TNx, this increasing trend was mainly observed in the Gobi Mongolia, while for TXn and TNn, this increasing trend was observed over the entire country. A significant reduction at a rate of −0.6 d decade−1 (−1.0 d decade−1 occurred for cool nights (days, and a significant increase at a rate of 2.8 d decade−1 (3.1 d decade−1 occurred for warm nights (days. The reduction of cool nights and cool days occurred over four seasons, while the increase of warm days and warm nights occurred mainly in summer.

  2. Trophic specialization drives morphological evolution in sea snakes.

    Science.gov (United States)

    Sherratt, Emma; Rasmussen, Arne R; Sanders, Kate L

    2018-03-01

    Viviparous sea snakes are the most rapidly speciating reptiles known, yet the ecological factors underlying this radiation are poorly understood. Here, we reconstructed dated trees for 75% of sea snake species and quantified body shape (forebody relative to hindbody girth), maximum body length and trophic diversity to examine how dietary specialization has influenced morphological diversification in this rapid radiation. We show that sea snake body shape and size are strongly correlated with the proportion of burrowing prey in the diet. Specialist predators of burrowing eels have convergently evolved a 'microcephalic' morphotype with dramatically reduced forebody relative to hindbody girth and intermediate body length. By comparison, snakes that predominantly feed on burrowing gobies are generally short-bodied and small-headed, but there is no evidence of convergent evolution. The eel specialists also exhibit faster rates of size and shape evolution compared to all other sea snakes, including those that feed on gobies. Our results suggest that trophic specialization to particular burrowing prey (eels) has invoked strong selective pressures that manifest as predictable and rapid morphological changes. Further studies are needed to examine the genetic and developmental mechanisms underlying these dramatic morphological changes and assess their role in sea snake speciation.

  3. Otolith microchemistry of tropical diadromous fishes: spatial and migratory dynamics

    Science.gov (United States)

    Smith, William E.; Kwak, Thomas J.

    2014-01-01

    Otolith microchemistry was applied to quantify migratory variation and the proportion of native Caribbean stream fishes that undergo full or partial marine migration. Strontium and barium water chemistry in four Puerto Rico, U.S.A., rivers was clearly related to a salinity gradient; however, variation in water barium, and thus fish otoliths, was also dependent on river basin. Strontium was the most accurate index of longitudinal migration in tropical diadromous fish otoliths. Among the four species examined, bigmouth sleeper Gobiomorus dormitor, mountain mullet Agonostomus monticola, sirajo goby Sicydium spp. and river goby Awaous banana, most individuals were fully amphidromous, but 9-12% were semi-amphidromous as recruits, having never experienced marine or estuarine conditions in early life stages and showing no evidence of marine elemental signatures in their otolith core. Populations of one species, G. dormitor, may have contained a small contingent of semi-amphidromous adults, migratory individuals that periodically occupied marine or estuarine habitats (4%); however, adult migratory elemental signatures may have been confounded with those related to diet and physiology. These findings indicate the plasticity of migratory strategies of tropical diadromous fishes, which may be more variable than simple categorization might suggest.

  4. Characteristics of Land Use/Cover and Macroscopic Ecological Changes in the Headwaters of the Yangtze River and of the Yellow River over the Past 30 Years

    Directory of Open Access Journals (Sweden)

    Lulu Liu

    2016-03-01

    Full Text Available Based on land use and land cover (LULC datasets in the late 1970s, the early 1990s, 2004 and 2012, we analyzed characteristics of LULC change in the headwaters of the Yangtze River and Yellow River over the past 30 years contrastively, using the transition matrix and LULC change index. The results showed that, in 2012, the LULC in the headwaters of the Yellow River were different compared to those of the headwaters of the Yangtze River, with more grassland and wet- and marshland. In the past 30 years, the grassland and wet- and marshland increasing at the expense of sand, gobi, and bare land and desert were the main LULC change types in the headwaters of the Yangtze River, with the macro-ecological situation experiencing a process of degeneration, slight melioration, and continuous melioration, in that order. In the headwaters of the Yellow River, severe reduction of grassland coverage, shrinkage of wet- and marshland and the consequential expansion of sand, gobi and bare land were noticed. The macro-ecological situation experienced a process of degeneration, obvious degeneration, and slight melioration, in that order, and the overall change in magnitude was more dramatic than that in the headwaters of the Yangtze River. These different LULC change courses were jointly driven by climate change, grassland-grazing pressure, and the implementation of ecological construction projects.

  5. Indicator polychlorinated biphenyl residues in muscle tissue of fish from Black Sea coast of Bulgaria

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    S. Georgieva

    2016-06-01

    Full Text Available Abstract. Polychlorinated biphenyls (PCBs are characterized by high lipophilicity and persistence in the environment and will therefore bioaccumulate and biomagnify in the food chain. PCBs were determined in muscle tissue of four fish species: goby (Neogobius melanostomus, horse mackerel (Trachurus Mediterraneus ponticus, shad (Alosa pontica pontica and turbot (Psetta maxima maeotica. Samples were collected from Bulgarian Black Sea coast during 2007 – 2011. The PCBs were analyzed in order to examine the time trends of PCB concentrations in fish from Black Sea. The six individual PCBs congeners were determined by capillary gas chromatography system with mass spectrometry detection. PCBs were found in all fish species at concentrations ranging between 2.32 ng/g ww (wet weight and 32.87 ng/g ww in goby and shad, respectively. PCB profiles have been found to be similar in all the fish species tested. The most abundant PCB congeners in fish species were hexa- and heptachlorinated PCBs 138, 153 and 180. PCB 153 was the dominant congener in all fish studied and were found in the range from 0.95 ng/g ww (horse mackerel 2011 to 11.67 ng/g ww (shad 2010. The sum of six indicator PCBs in all fish species did not exceed the European maximum limit of 75 ng/g ww. The levels of PCBs in fish from Bulgarian Black Sea coast were found lower than in fish species from other seas – the Aegean Sea and the Mediterranean Sea.

  6. Dynamic modeling predicts continued bioaccumulation of polybrominated diphenyl ethers (PBDEs) in smallmouth bass (Micropterus dolomiu) post phase-out due to invasive prey and shifts in predation

    International Nuclear Information System (INIS)

    Wallace, Joshua S.; Blersch, David M.

    2015-01-01

    Unprecedented food chain links between benthic and pelagic organisms are often thought to disrupt traditional contaminant transport and uptake due to changes in predation and mobilization of otherwise sequestered pollutants. A bioaccumulation model for polybrominated diphenyl ethers (PBDEs) is developed to simulate increases in biotic congener loads based upon trophic transfer through diet and gill uptake for a Lake Erie food chain including two invasive species as a benthic-pelagic link. The model utilizes species-specific bioenergetic parameters in a four-level food chain including the green alga Scenedesmus quadricauda, zebra mussels (Dreissena polymorpha), round goby (Appollonia melanostoma), and the smallmouth bass (Micropterus dolomiu). The model was calibrated to current biotic concentrations and predicts an increase in contaminant load by almost 48% in the upper trophic level in two years. Validation to archival data resulted in <2% error from reported values following a two-year simulation. - Highlights: • A dynamic model assesses continued bioaccumulation of PBDEs in predators of invasive prey. • The model incorporates novel benthic-pelagic energy links due to invasive prey. • Increases in total PBDEs in smallmouth bass due to invasive energy pathways are simulated. • The model is validated to archival data obtained prior to invasion of zebra mussels and round goby. - A dynamic model is developed to simulate continued bioaccumulation of polybrominated diphenyl ethers (PBDEs) in smallmouth bass due to emerging benthic-pelagic energy pathways.

  7. Great Lakes prey fish populations: a cross-basin overview of status and trends based on bottom trawl surveys, 1978-2013

    Science.gov (United States)

    Gorman, Owen T.; Weidel, Brian C.

    2014-01-01

    The assessment of Great Lakes prey fish stocks have been conducted annually with bottom trawls since the 1970s by the Great Lakes Science Center, sometimes assisted by partner agencies. These stock assessments provide data on the status and trends of prey fish that are consumed by important commercial and recreational fishes. Although all these annual surveys are conducted using bottom trawls, they differ among the lakes in the proportion of the lake covered, seasonal timing, trawl gear used, and the manner in which the trawl is towed (across or along bottom contours). Because each assessment is unique, population indices were standardized to the highest value for a time series within each lake for the following prey species: Cisco (Coregonus artedi), Bloater (C. hoyi), Rainbow Smelt (Osmerus mordax), Alewife (Alosa pseudoharengus), and Round Goby (Neogobius melanostomus). In this report, standardized indices are presented in graphical form along with synopses to provide a short, informal cross-basin summary of the status and trends of principal prey fishes. There was basin-wide agreement in the trends of age-1 and older biomass for all prey species, with the highest concordance occurring for coregonids and Rainbow Smelt, and weaker concordance for Alewife. For coregonids, the highest biomass occurred from the mid-1980s to the mid-1990s. Rainbow Smelt biomass declined slowly and erratically during the last quarter century. Alewife biomass was generally higher from the early 1980s through 1990s across the Great Lakes, but since the early 1990s, trends have been divergent across the lakes, though there has been a downward trend in all lakes since 2005. Recently, Lake Huron has shown resurgence in biomass of Bloater, achieving 75% of its maximum record in 2012 due to recruitment of a succession of strong and moderate year classes that appeared in 2005-2011. Also, strong recruitment of the 2010 year class of Alewife has led to a sharp increase in biomass of Alewife in

  8. KEANEKARAGAMAN SPESIES AMFIBI DAN REPTIL DI KAWASAN SUAKA MARGASATWA SERMODAERAH ISTIMEWA YOGYAKARTA

    Directory of Open Access Journals (Sweden)

    D S Yudha

    2016-03-01

    Full Text Available Kawasan Suaka Margasatwa (SM Sermo merupakan salah satu kawasan lindung yang terdapat di Daerah Istimewa Yogyakarta. Kawasan tersebut merupakan habitat bagi berbagai jenis tumbuhan dan hewan, salah satunya adalah herpetofauna (amfibi dan reptil. Hutan di kawasan SM Sermo terdiri dari hutan sekunder yang umum dimasuki manusia dengan kerapatan vegetasi kurang dari 90%, dengan ketinggian antara 90-250 mdpl dan luas sekitar 181 ha. Sampling dilakukan selama dua hari tanggal 13-14 Januari 2013, dan dilakukan pada pagi dan malam hari dengan metode sampling perpaduan antara VES (Visual Encounter Survey, Time Search, dan Road Cruising. Hasil identifikasi diperoleh 5 (lima spesies amfibi dan 13 (tiga belas spesies reptil. Spesies amfibi yang ditemukan di kawasan SM Sermo adalah Fejervarya limnocharis, Duttaphrynus melanostictus, Ingerophrynus biporcatus, Polypedates leucomystax, dan Kaloula baleata. Reptil yang ditemukan terdiri atas dua Subordo, yaitu Subordo Serpentes (ular, dan Subordo Lacertilia (kadal. Subordo Serpentes yang ditemukan terdiri dari 4 (empat spesies, yaitu Ahaetulla prasina, Rhabdophis subminiatus, Pareas carinatus, dan Rhamphotyphlops braminus. Subordo Lacertilia yang ditemukan terdiri dari 9 (sembilan spesies, yaitu Draco volans, Dasia olivacea, Eutropis multifasciata, Eutropis rugifera, Hemidactylus frenatus, Gekko gecko, Cyrtodactylus marmoratus, Lygosoma quadrupes, dan Hemiphyllodactylus typus. Seiring berjalannya waktu, penambahan atau pengurangan jumlah spesies yang terdapat di kawasan SM Sermo dapat terjadi. Dengan demikian, monitoring jenis herpetofauna perlu dilakukan secara rutin untuk memantau keanekaragamannya di kawasan ini.Sermo is one of wildlife sanctuary which located in Daerah Istimewa Yogyakarta. It consists of several unique habitats for wildlife such as herpetofauna (amphibians and reptiles. Forest habitat mostly composed by secondary forest with the vegetation coverage less than 90% in 90-250 meters above sea

  9. Dieta y parasitismo de Leptodactylus diptyx (Anura: Leptodactylidae del nordeste argentino Diet and parasitism of Leptodactylus diptyx (Anura: Leptodactylidae from Northeastern Argentina

    Directory of Open Access Journals (Sweden)

    Víctor Hugo Zaracho

    2012-12-01

    Full Text Available Diversos aspectos de la historia natural de especies del grupo Leptodactylus marmoratus son escasamente conocidos y la poca información existente aborda principalmente los de la biología reproductiva. El objetivo de este trabajo es aportar información acerca de la dieta y del parasitismo de poblaciones de Leptodactylus diptyx del nordeste argentino. Para el estudio trófico, se analizó el contenido estomacal e intestinal de 22 individuos adultos, mientras que para el estudio parasitario, se examinó el tubo digestivo de 40 individuos. Se registró un total de 91 presas, clasificadas en 17 categorías, entre los cuales los himenópteros formícidos fueron los más numerosos (45% y frecuentes (55%. Otras presas importantes fueron colémbolos, coleópteros y arañas. Los valores de diversidad de presas (índice de Shannon y amplitud del nicho (índice de Levins fueron 2.06 y 4.29, respectivamente. El 57.5% de los individuos examinados resultó positivo al examen de endoparásitos, entre los que se incluyen nematodos y acantocefalos. Leptodactylus diptyx representa un nuevo hospedador para los nematodos Cosmocerca sp. y Aplectana sp.The natural history of the Leptodactylus marmoratus species group is poorly known, and there is scarce available information mainly referred to aspects of the reproductive biology. The objective of this study was to contribute to the knowledge of the trophic biology and of the parasitism of Leptodactylus diptyx populations from Northeastern Argentina. The stomach and intestine contents of 22 adult individuals were analyzed for the trophic study, while the alimentary canal and body cavity of 40 individuals were examined for parasites. The diet consisted of 17 different prey items, including mainly Formicidae hymenopterans, collembolans, coleopterans, and spiders. The values of prey diversity calculated by Shannon's index (H' and niche amplitude by Levins's index were 2.06 and 4.29, respectively. The 57.5% of the

  10. Unravelling population genetic structure with mitochondrial DNA in a notional panmictic coastal crab species: sample size makes the difference.

    Science.gov (United States)

    Fratini, Sara; Ragionieri, Lapo; Deli, Temim; Harrer, Alexandra; Marino, Ilaria A M; Cannicci, Stefano; Zane, Lorenzo; Schubart, Christoph D

    2016-07-26

    The extent of genetic structure of a species is determined by the amount of current gene flow and the impact of historical and demographic factors. Most marine invertebrates have planktonic larvae and consequently wide potential dispersal, so that genetic uniformity should be common. However, phylogeographic investigations reveal that panmixia is rare in the marine realm. Phylogeographic patterns commonly coincide with geographic transitions acting as barriers to gene flow. In the Mediterranean Sea and adjoining areas, the best known barriers are the Atlantic-Mediterranean transition, the Siculo-Tunisian Strait and the boundary between Aegean and Black seas. Here, we perform the so far broadest phylogeographic analysis of the crab Pachygrapsus marmoratus, common across the north-eastern Atlantic Ocean, Mediterranean and Black seas. Previous studies revealed no or weak genetic structuring at meso-geographic scale based on mtDNA, while genetic heterogeneity at local scale was recorded with microsatellites, even if without clear geographic patterns. Continuing the search for phylogeographic signal, we here enlarge the mtDNA dataset including 51 populations and covering most of the species' distribution range. This enlarged dataset provides new evidence of three genetically separable groups, corresponding to the Portuguese Atlantic Ocean, Mediterranean Sea plus Canary Islands, and Black Sea. Surprisingly, hierarchical AMOVA and Principal Coordinates Analysis agree that our Canary Islands population is closer to western Mediterranean populations than to mainland Portugal and Azores populations. Within the Mediterranean Sea, we record genetic homogeneity, suggesting that population connectivity is unaffected by the transition between the western and eastern Mediterranean. The Mediterranean metapopulation seems to have experienced a relatively recent expansion around 100,000 years ago. Our results suggest that the phylogeographic pattern of P. marmoratus is shaped by the

  11. Spatial Distribution of Oxygen Isotope of Quartz from Major Asian Dust Sources and Its Application in Source Tracing of Aeolian Dust

    Science.gov (United States)

    Yan, Y.; Sun, Y.

    2015-12-01

    Provenance studies of aeolian dust in East Asia had made much progress. The interpretations of the provenance of modern aeolian dust and paleo-dust (loess) sequences, however, still suffer disputes. To provide more scientific evidence, we present a provenance study using oxygen isotope (δ18O) of quartz as a tracer. We studied the quartz δ18O of both fine (Asia, including the Taklimakan desert, Mongolian Gobi, Badain Juran desert, Tengger desert, Mu Us desert, and Qaidam Basin. Among them, quartz δ18O of both fractions shows consonant increasing trend from the Mongolian Gobi, to the northern Chinese deserts (i.e. Badain Juran, Tennger, and Mu Us deserts), Qaidam Basin, and then to the Taklimakan desert, indicating a decreasing igneous rock coverage in the sources. The coverage ratio survey of the igneous rocks in different sources corroborated this inference. Using quartz δ18O of both fractions can differentiate dust from the Mongolian Gobi, Taklimakan desert and the northern Chinese deserts. Combination of quartz δ18O and quartz Electronic Spinning Resonance signal intensity (ESR) - Crystalinity Index (CI) from previous studies helps further the differentiation. The bivariate plot of quartz δ18O and CI of fine fraction can make clear separation of dust from different sources, regardless of single-sourced or mixed dust, while the trivariate plot of quartz δ18O, ESR, and CI of fine fraction can further increase the differentiability. Applying quartz δ18O-CI, we found that the four natural dust storm events happening in Xi'an in the spring of 2012 mainly originated from the northern Chinese deserts. Dust entrainment monitoring by MODIS images and air mass transport route simulation by back trajectory modeling show that the dust plumes or dust-containing air parcels originating from the northern Chinese deserts reached Xi'an on those dust storm days, thus confirmed the source tracer comparison results. Our study supports the previous proximal

  12. Status and trends of prey fish populations in Lake Michigan, 2013

    Science.gov (United States)

    Madenjian, Charles P.; Bunnell, David B.; Desorcie, Timothy J.; Kostich, Melissa Jean; Armenio, Patricia M.; Adams, Jean V.

    2015-01-01

    The U.S. Geological Survey Great Lakes Science Center has conducted lake-wide surveys of the fish community in Lake Michigan each fall since 1973 using standard 12-m bottom trawls towed along contour at depths of 9 to 110 m at each of seven index transects. The resulting data on relative abundance, size and age structure, and condition of individual fishes are used to estimate various population parameters that are in turn used by state and tribal agencies in managing Lake Michigan fish stocks. All seven established index transects of the survey were completed in 2013. The survey provides relative abundance and biomass estimates between the 5-m and 114-m depth contours of the lake (herein, lake-wide) for prey fish populations, as well as burbot, yellow perch, and the introduced dreissenid mussels. Lake-wide biomass of alewives in 2013 was estimated at 29 kilotonnes (kt, 1 kt = 1000 metric tonnes), which was more than three times the 2012 estimate. However, the unusually high standard error associated with the 2013 estimate indicated no significant increase in lake-wide biomass between 2012 and 2013. Moreover, the age distribution of alewives remained truncated with no alewife exceeding an age of 5. The population of age-1 and older alewives was dominated (i.e., 88%) by the 2010 and 2012 year-classes. Record low biomass was observed for deepwater sculpin (1.3 kt) and ninespine stickleback (0.004 kt) in 2013, while bloater (1.6 kt) and rainbow smelt (0.2 kt) biomasses remained at low levels. Slimy sculpin lake-wide biomass was 0.32 kt in 2013, marking the fourth consecutive year of a decline. The 2013 biomass of round goby was estimated at 10.9 kt, which represented the peak estimate to date. Burbot lake-wide biomass (0.4 kt in 2013) has remained below 3 kt since 2001. Numeric density of age-0 yellow perch (i.e., fish per ha, which is indicative of a relatively poor year-class. Lake-wide biomass estimate of dreissenid mussels in 2013 was 23.2 kt. Overall, the total

  13. INVESTIGATION OF LITHOSPHERIC STRUCTURE IN MONGOLIA: INSIGHTS FROM INSAR OBSERVATIONS AND MODELLING

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    Z. Jing

    2017-09-01

    Full Text Available The western Mongolia is a seismically active intracontinental region, with ongoing tectonic deformation and widespread seismicity related to the far-field effects of India-Eurasia collision. During the 20th century, four earthquakes with the magnitude larger than 8 occurred in the western Mongolia and its surrounding regions, providing a unique opportunity to study the geodynamics of intracontinental tectonic deformations. The 1957 magnitude 8.3 Gobi-Altai earthquake is one of the largest seismic events. The deformation pattern of rupture zone associated with this earthquake is complex, involving left-lateral strike-slip and reverse dip-slip faulting on several distinct geological structures in a 264 × 40 km wide zone. To understand the relationship between the observed postseismic surface deformation and the rheological structure of the upper lithosphere, Interferometric Synthetic Aperture Radar (InSAR data are used to study the 1957 earthquake. Then we developed a postseismic model in a spherical, radially layered elastic-viscoelastic Earth based on InSAR results, and further analysed the dominant contribution to the surface deformation. This work is important for understanding not only the regional tectonics, but also the structure and dynamics of the lithosphere. SAR data were acquired from the ERS1/2 and Envisat from 1996 to 2010. Using the Repeat Orbit Interferometry Package (ROI_PAC, 124 postseismic interferograms are produced on four adjacent tracks. By stacking these interferograms, the maximum InSAR line-of-sight deformation rate along the Gobi-Altai fault zone is obtained. The main results are as follows: (1 The maximum InSAR line-of-sight deformation velocity along this large fault zone is about 6 mm/yr; (2 The modelled surface deformation suggests that the viscoelastic relaxation is the most reasonable mechanism to explain the observed surface motion; (3 The optimal model cover the Gobi-Altai seismogenic thickness is 10

  14. Slip rate and slip magnitudes of past earthquakes along the Bogd left-lateral strike-slip fault (Mongolia)

    Science.gov (United States)

    Prentice, Carol S.; Rizza, M.; Ritz, J.F.; Baucher, R.; Vassallo, R.; Mahan, S.

    2011-01-01

    We carried out morphotectonic studies along the left-lateral strike-slip Bogd Fault, the principal structure involved in the Gobi-Altay earthquake of 1957 December 4 (published magnitudes range from 7.8 to 8.3). The Bogd Fault is 260 km long and can be subdivided into five main geometric segments, based on variation in strike direction. West to East these segments are, respectively: the West Ih Bogd (WIB), The North Ih Bogd (NIB), the West Ih Bogd (WIB), the West Baga Bogd (WBB) and the East Baga Bogd (EBB) segments. Morphological analysis of offset streams, ridges and alluvial fans—particularly well preserved in the arid environment of the Gobi region—allows evaluation of late Quaternary slip rates along the different faults segments. In this paper, we measure slip rates over the past 200 ka at four sites distributed across the three western segments of the Bogd Fault. Our results show that the left-lateral slip rate is∼1 mm yr–1 along the WIB and EIB segments and∼0.5 mm yr–1 along the NIB segment. These variations are consistent with the restraining bend geometry of the Bogd Fault. Our study also provides additional estimates of the horizontal offset associated with the 1957 earthquake along the western part of the Bogd rupture, complementing previously published studies. We show that the mean horizontal offset associated with the 1957 earthquake decreases progressively from 5.2 m in the west to 2.0 m in the east, reflecting the progressive change of kinematic style from pure left-lateral strike-slip faulting to left-lateral-reverse faulting. Along the three western segments, we measure cumulative displacements that are multiples of the 1957 coseismic offset, which may be consistent with a characteristic slip. Moreover, using these data, we re-estimate the moment magnitude of the Gobi-Altay earthquake at Mw 7.78–7.95. Combining our slip rate estimates and the slip distribution per event we also determined a mean recurrence interval of∼2500

  15. Seasonal Variation, Export Dynamics and Consumption of Freshwater Invertebrates in an Estuarine Environment

    Science.gov (United States)

    Williams, D. D.; Williams, N. E.

    1998-03-01

    sections but resumed a benthic existence by virtue of varying degrees of salt tolerance. Of the three fish species common in the estuary, eel, common goby and flounder, the last two preyed measurably on freshwater taxa. Whereas gobies tended to be opportunistic feeders, depending on the section of estuary that they occupied, flounder were more restricted to the upper estuary where they fed selectively on chironomid larvae. On the latter diet, between March and September, the mean wet weight of flounders increased by more than 100 times (from 5 to 540 mg). Gobies were more numerous in the estuary from September to February, and although they ate insects their primary prey was G. zaddachi.

  16. SALINITAS OPTIMAL UNTUK PENDEDERAN BENIH IKAN BETUTU (Oxyeleotris marmorata

    Directory of Open Access Journals (Sweden)

    Idil Ardi

    2017-01-01

    Full Text Available Ikan betutu (Oxyeleotris marmorata termasuk ikan perairan tawar yang memiliki nilai ekonomis penting dan sangat disukai karena memiliki daging yang tebal, tulangnya sedikit, dan gurih. Salah satu faktor lingkungan yang berpengaruh dalam kegiatan budidaya adalah salinitas. Penelitian bertujuan untuk mendapatkan salinitas optimum dalam pemeliharaan benih ikan betutu yang diharapkan dapat meningkatkan sintasan dan pertumbuhannya. Penelitian menggunakan rancangan acak lengkap (RAL dengan empat perlakukan berdasarkan perbedaan salinitas yaitu kontrol ppt, 1 ppt, 3 ppt, dan 5 ppt. Setiap perlakuan dilakukan tiga kali pengulangan. Hasil penelitian menunjukkan terdapat perbedaan nyata (P<0,05 terhadap laju pertumbuhan spesifik, panjang mutlak, bobot mutlak, dan kadar glukosa darah terhadap kontrol (salinitas 0 ppt setelah dipelihara selama 56 hari. Laju pertumbuhan mutlak, bobot mutlak, dan glukosa darah paling baik dijumpai pada benih yang dipelihara dengan salinitas 3 ppt, yaitu 0,94 ± 0,09%; 2,53 ± 0,35 mm; 37,33 ± 6,28 g; dan 0,06 ± 0,01 g/dL. Pemeliharaan benih betutu membutuhkan air bersalinitas. Untuk mengoptimalkan pertumbuhan dan sintasan air media budidaya disarankan bersalinitas 3 ppt. Sand goby (Oxyeleotris marmorata is one of freshwater fish that has high economic value and is more desired for its thick meat, bone less, and tasteful. Salinity is one of the most important environmental factors in fish culture. The purpose of this study was to determine the optimal salinity concentration on growth and survival of sand goby fish. A completely Randomized Design (CRD was used in this study with four treatments of salinity levels comprising A Control; B 1 ppt; C 3 ppt; D 5 ppt. Each treatment was consisted of three replicates. The result showed significant differences (P<0.05 in specific growth rate, absolute length, absolute weight, and blood glucose among the treatments against control after 56 days cultured. Seed reared under the salinity

  17. ACCUMULATION OF SELENIUM IN AQUATIC ORGANISMS OF THE CASPIAN SEA

    Directory of Open Access Journals (Sweden)

    N. A. Golubkina

    2012-01-01

    Full Text Available The question of establishing the levels of selenium accumulation in fish Marine has consistently attracted the attention of researchers. This is due, no doubt, with a surprisingly high concentrations of trace elements in fishmuscle mass compared with terrestrial animals and the wide spread lack of public consumption of selenium in most countries of the world. By the ability to accumulate selenium species investigated can be arranged in series: carp < rudd < pike Kutum < perch < carp < mullet < silverside < pike < roach < sprat common < gobies < sprat anchovy << sturgeon. It is known that the main source of selenium to fish is the food, although there is some element passes through the gills during respiration. Comparing the results with data accumulation of selenium muscle tissue of fish from different regions of the world indicates the absence of express selenodefitsita in the Caspian Sea.

  18. LOSA-M2 aerosol Raman lidar

    Science.gov (United States)

    Balin, Yu S.; Bairashin, G. S.; Kokhanenko, G. P.; Penner, I. E.; Samoilova, S. V.

    2011-10-01

    The scanning LOSA-M2 aerosol Raman lidar, which is aimed at probing atmosphere at wavelengths of 532 and 1064 nm, is described. The backscattered light is received simultaneously in two regimes: analogue and photon-counting. Along with the signals of elastic light scattering at the initial wavelengths, a 607-nm Raman signal from molecular nitrogen is also recorded. It is shown that the height range of atmosphere probing can be expanded from the near-Earth layer to stratosphere using two (near- and far-field) receiving telescopes, and analogue and photon-counting lidar signals can be combined into one signal. Examples of natural measurements of aerosol stratification in atmosphere along vertical and horizontal paths during the expeditions to the Gobi Desert (Mongolia) and Lake Baikal areas are presented.

  19. Study on atmosphere pollution by PIXE analysis combining with statistical method

    International Nuclear Information System (INIS)

    Zhu Guanghua

    1994-06-01

    Atmospheric aerosol samples were collected using an 8-stage cascade impactor or an automatic time sequence step sampler at Jomo Langma, Zhangye at the edge of Gobi Desert and Beijing. Element concentration were analyzed by PIXE (proton induced X-ray emission) technique. The data were analyzed by APCA (absolute principal component analysis) to determine the principal components. The sources and contribution to the aerosol in the above three regions were discussed. The result shows that the PIXE has high sensitivity, multi-element capability, high speed and non-destruction advantages. APCA analytical method can effectively determine the aerosol components in urban area, and it also can distinguish between local components and remote components in the area far from the pollution resources

  20. Recent rapid speciation and ecomorph divergence in Indo-Australian sea snakes. Molecular Evolution

    DEFF Research Database (Denmark)

    Sanders, Kate L.; Redsted Rasmussen, Arne; Mumpuni

    2013-01-01

    -morphological differentiation in a clade of four nominal species with overlapping ranges in Southeast Asia and Australia. Analyses of morphology and stomach contents identified the presence of two distinct ecomorphs: a ‘macrocephalic’ ecomorph that reaches >2 m in length, has a large head and feeds on crevice-dwelling eels...... and gobies; and a ‘microcephalic’ ecomorph that rarely exceeds 1 m in length, has a small head and narrow fore-body and hunts snake eels in burrows. Mitochondrial sequences show a lack of reciprocal monophyly between ecomorphs and among putative species. However, individual assignment based on newly...... developed microsatellites separated co-distributed specimens into four significantly differentiated clusters corresponding to morphological species designations, indicating limited recent gene flow and progress towards speciation. A coalescent species tree (based on mitochondrial and nuclear sequences...

  1. A freshwater species wintering in a brackish environment: Habitat selection and diet of Slavonian grebes in the southern Baltic Sea

    Science.gov (United States)

    Sonntag, Nicole; Garthe, Stefan; Adler, Sven

    2009-09-01

    After the breeding season, Slavonian grebes ( Podiceps auritus) leave their freshwater breeding habitats and migrate to wintering grounds in marine or brackish waters. The most important wintering area in northwestern Europe is located in the southern Baltic Sea, with the largest concentrations in the offshore area of the Pommeranian Bight. Analysis of ship-based surveys revealed that the habitat selection of Slavonian grebes in this brackish area is significantly influenced by water depth and bottom sediment type. The grebes prefer shallow waters of 4-14 m depth and occur only over sandy sediments. While the diving depths of endothermic animals is limited due to energetic constraints and thermoregulation, sediment type is regarded to be a proxy for food choice. The diet of Slavonian grebes in the Pomeranian Bight consists mainly of demersal gobies (Gobiidae) that frequently occur over sandy bottom substrates.

  2. The diet and consumption of dominant fish species in the upper Scheldt estuary, Belgium

    DEFF Research Database (Denmark)

    Maes, J.; De Brabandere, Loreto; Ollevier, F.

    2003-01-01

    Seasonal changes in the diet composition and trophic niche overlap were examined for the dominant members of the fish assemblage of the turbid low-salinity zone of the Scheldt estuary (Belgium). Samples of fish were taken in the cooling water of a power plant. Juveniles of eight species dominated...... the fish assemblage: two goby species, herring, sprat, bass, flounder, eel and pikeperch. Together, they had preyed upon 31 different prey taxa. Calanoid copepods and hyperbenthic mysids were the most important prey items with macrobenthic invertebrates being largely ignored. Pair-wise comparisons...... of trophic niche overlap showed that, in general, niche overlap between individuals of the same species was significantly higher than overlap between individuals from different species, suggesting that the available food resources were partitioned. The total annual prey consumption by the dominant fish...

  3. Energy from the desert. Very large scale photovoltaic systems: socio-economic, financial, technical and environmental aspects. Executive summary

    Energy Technology Data Exchange (ETDEWEB)

    Kurokawa, K.; Ito, M.; Komoto, K.; Vleuten, P. van der; Faiman, D. (eds.)

    2009-05-15

    This executive summary report for the International Energy Agency (IEA) summarises the objectives and concepts of very large scale photovoltaic power generation (VLS-PV) systems and takes a look at the socio-economic, financial and technical aspects involved as well as the environmental impact of such systems. Potential benefits for desert communities, agricultural development and desalination of water are topics that are looked at. The potential of VLS-PV, its energy payback time and CO{sub 2} emission rates are discussed. Case studies for the Sahara and the Gobi Dessert areas are discussed. A VLS-PV roadmap is proposed and scenarios are discussed. Finally, conclusions are drawn and recommendations are made.

  4. Reducing organic contamination of shallow areas in brackish lagoons during rearing fish in cages in polyculture

    Directory of Open Access Journals (Sweden)

    P. Shekk

    2017-07-01

    Full Text Available Purpose. The development of the technology of the controlled rearing of marine fish remains one of the priority strategic trends of development of national mariculture. A study of the possibility of using polyculture for cage culture has a particular interest. Joint cultivation of several species of fish in the same cage, as practice of fish farming has demonstrated, does not have a tangible positive effect. At the same time, the use of cages of special design can provide significant additional fish products through the use of additional aquaculture objects. The ecological state of water areas, where the cages are located, is of great importance. High fish stocking density and the use of artificial feeds can serve as a source of powerful biogenic and organic pollution, which is especially important for shallow water areas with weak water exchange. The purpose of the study is to develop the methods for joint fish production in cage mariculture capable to provide high fish production and to weaken organic pollution of shallow water areas where cage farms are located. Methodology. The studies were conducted in 1999 and 2004. Cages of special design (internal 10 m3 and external 18.75 m3 installed in the brackish Shabolat Lagoon were used for rearing, steelhead trout, haarder, grass goby and round goby in polyculture. The standard aquaculture research methods were used. For express-analysis of environment hydrochemical parameters in cage location area the following devices were used: "ECOTEST-2000 T" (О2, NO2, NO3, NH4, CO2, phosphates, pH; termooksimetr "АJА-101М" (Т; О2; "pH meter-150 M; Refractometer "ATAGO-100" (salinity and water density. Findings. The results of marine fish cultivation in cages in polyculture in the shallow Shabolat lagoon are presented. It has been shown that joint cultivation of salmon, mullet and gobies in specially designed cages in shallow marine lagoons allows using artificial and natural feeds more fully and

  5. Synthesis of (3S,3′S- and meso-Stereoisomers of Alloxanthin and Determination of Absolute Configuration of Alloxanthin Isolated from Aquatic Animals

    Directory of Open Access Journals (Sweden)

    Yumiko Yamano

    2014-05-01

    Full Text Available In order to determine the absolute configuration of naturally occurring alloxanthin, a HPLC analytical method for three stereoisomers 1a–c was established by using a chiral column. Two authentic samples, (3S,3′S- and meso-stereoisomers 1b and 1c, were chemically synthesized according to the method previously developed for (3R,3′R-alloxanthin (1a. Application of this method to various alloxanthin specimens of aquatic animals demonstrated that those isolated from shellfishes, tunicates, and crucian carp are identical with (3R,3′R-stereoisomer 1a, and unexpectedly those from lake shrimp, catfish, biwa goby, and biwa trout are mixtures of three stereoisomers of 1a–c.

  6. A model of trophic flows in the northern Benguela upwelling system during the 1980s

    DEFF Research Database (Denmark)

    Shannon, L.J.; Jarre, Astrid

    1999-01-01

    A model of trophic flows through the northern Benguela between 1980 and 1989 was constructed using the ECOPATH approach. The model serves to close the temporal gap between models of the system for the 1970s and 1990s. The aim is to provide a workable model, with the intention of encouraging...... scientists working on different components of the ecosystem to collaborate to improve and update the model for more recent years. Ultimately, this type of model may form a basis for multispecies management approaches in the region. By the 1980s, sardine Sardinops sagax and hake Merluccius spp. stocks...... in the northern Benguela had both undergone a decline, yet were still heavily fished. Horse mackerel Trachurus trachurus capensis had increased over the previous decade and was the dominant pelagic species during the 1980s, with high catches. Production by some groups, such as goby Sufflogobius bibarbatus...

  7. Small‐scale distribution of fish in offshore windfarms

    DEFF Research Database (Denmark)

    Hansen, Kamilla Sande; Stenberg, Claus; Møller, Peter Rask

    2012-01-01

    Knowledge about small‐scale distribution of fish around turbines in offshore windfarms (OWF) remains relatively scarce. In the present study we used underwater video camera installations to access abundance of fish at 0, 25, and 50 m around the turbine foundations in Middelgrund and Lillgrund OWFs...... in Øresund between Denmark and Sweden in the period August–November 2011. Fish fauna in both localities were dominated in terms of numbers by two‐spotted gobies (Gobiusculus flavescens). Average number of fish observed per hour was a factor 100 higher at Lillgrund and a factor of 2 higher at Middelgrund at 0...... on fish fauna compared to OWFs in areas with heterogeneous sediment. Furthermore, the effect of OWFs on fish appears to be of a much smaller scale than previously thought...

  8. Organochlorine contaminants (PCBs, DDTs, HCB

    Directory of Open Access Journals (Sweden)

    Georgieva Stanislava

    2015-06-01

    Full Text Available Concentrations of organochlorine compounds such as polychlorinated biphenyls (PCBs, DDT and its metabolites, hexachlorobenzene (HCB and hexachlorobutadiene (HBDE were determined in three fish species: goby (Neogobius melanostomus, golden grey mullet (Mugil auratus and silverside (Atherina boyeri. Samples were collected from the Lake Varna and the Lake Beloslav in 2014. The edible fish tissues were analyzed in order to investigate the presence of pollutants in species from the lakes near Varna City, Bulgaria and compared the results to the levels in other aquatic ecosystems. The fifteen congeners of PCBs, HCB, HCBD, DDT and its two main metabolites DDE and DDD were determined by capillary gas chromatography system with mass spectrometry detection. The OCPs levels in the wild fish were found in the order DDTs > PCBs. The other contaminants HCB and HCBD were not detected or were below the analytical detection limit. Among the pesticides, essentially only the metabolites p, p’- DDE and p, p’- DDD were found.

  9. Atmospheric movement of microorganisms in clouds of desert dust and implications for human health

    Science.gov (United States)

    Griffin, Dale W.

    2007-01-01

    Billions of tons of desert dust move through the atmosphere each year. The primary source regions, which include the Sahara and Sahel regions of North Africa and the Gobi and Takla Makan regions of Asia, are capable of dispersing significant quantities of desert dust across the traditionally viewed oceanic barriers. While a considerable amount of research by scientists has addressed atmospheric pathways and aerosol chemistry, very few studies to determine the numbers and types of microorganisms transported within these desert dust clouds and the roles that they may play in human health have been conducted. This review is a summary of the current state of knowledge of desert dust microbiology and the health impact that desert dust and its microbial constituents may have in downwind environments both close to and far from their sources.

  10. Spatial extent and dynamics of dam impacts on tropical island freshwater fish assemblages

    Science.gov (United States)

    Cooney, Patrick B.; Kwak, Thomas J.

    2013-01-01

    Habitat connectivity is vital to the persistence of migratory fishes. Native tropical island stream fish assemblages composed of diadromous species require intact corridors between ocean and riverine habitats. High dams block fish migration, but low-head artificial barriers are more widespread and are rarely assessed for impacts. Among all 46 drainages in Puerto Rico, we identified and surveyed 335 artificial barriers that hinder fish migration to 74.5% of the upstream habitat. We also surveyed occupancy of native diadromous fishes (Anguillidae, Eleotridae, Gobiidae, and Mugilidae) in 118 river reaches. Occupancy models demonstrated that barriers 2 meters (m) high restricted nongoby fish migration and extirpated those fish upstream of 4-m barriers. Gobies are adapted to climbing and are restricted by 12-m barriers and extirpated upstream of 32-m barriers. Our findings quantitatively illustrate the extensive impact of low-head structures on island stream fauna and provide guidance for natural resource management, habitat restoration, and water development strategies.

  11. Columbus State University Global Observation and Outreach for the 2012 Transit of Venus

    Science.gov (United States)

    Perry, Matthew; McCarty, C.; Bartow, M.; Hood, J. C.; Lodder, K.; Johnson, M.; Cruzen, S. T.; Williams, R. N.

    2013-01-01

    Faculty, staff and students from Columbus State University’s (CSU’s) Coca-Cola Space Science Center presented a webcast of the 2012 Transit of Venus from three continents to a global audience of 1.4 million unique viewers. Team members imaged the transit with telescopes using white-light, hydrogen-alpha, and calcium filters, from Alice Springs, Australia; the Gobi Desert, Mongolia; Bryce Canyon, UT; and Columbus, GA. Images were webcast live during the transit in partnership with NASA’s Sun-Earth Day program, and Science Center staff members were featured on NASA TV. Local members of the public were brought in for a series of outreach initiatives, in both Georgia and Australia, before and during the transit. The data recorded from the various locations have been archived for use in demonstrating principles such as the historical measurement of the astronomical unit.

  12. The diet of whiting Merlangius merlangus in the western Baltic Sea.

    Science.gov (United States)

    Ross, S D; Gislason, H; Andersen, N G; Lewy, P; Nielsen, J R

    2016-05-01

    The diet of whiting Merlangius merlangus in the western Baltic Sea was investigated and compared to the diet in the southern North Sea. Clupeids were important prey in both areas, but especially in the western Baltic Sea where they constituted up to 90% of the diet of larger individuals. Gobies, brown shrimps and polychaetes were the main prey of juveniles in the western Baltic Sea, while a wider range of species were consumed in the North Sea. The shift to piscivory occurred at smaller sizes in the western Baltic Sea and the fish prey consumed was proportionately larger than in the southern North Sea. Estimates of prey abundance and food intake of M. merlangus are required to evaluate its predatory significance in the western Baltic Sea, but its diet suggests that it could be just as significant a fish predator here as in the southern North Sea. © 2016 The Fisheries Society of the British Isles.

  13. Notes on shark and ray types at the South China Sea Fisheries Research Institute (SCSFRI) in Guangzhou, China.

    Science.gov (United States)

    White, William T; Last, Peter R

    2013-01-01

    Most of the shark and ray type material at the South China Sea Fisheries Research Institute (SCSFRI) in Guangzhou, China was examined during a museum visit by the senior author in 2009. The status of the shark and ray species described from the South China Sea in the 1980s and deposited in this collection is discussed. Squalus acutirostris is considered a junior synonym of Squalus mitsukurii from the western North Pacific. Centrophorus ferrugineus is considered a junior synonym of Centrophorus squamosus. Centroscymnus macrops is confirmed as a junior synonym of Centroscymnus coelolepis. Scymnodon niger is confirmed as a junior synonym of Zameus squamulosus. Isistius labialis is considered a synonym of Isistius brasiliensis. Halaelurus immaculatus is confirmed as a valid species of the genus Bythaelurus. Urolophus marmoratus is considered a junior synonym of the widespread Plesiobatis daviesi. Springeria nanhaiensis is a questionable synonym of Sinobatis borneensis, following previous researchers. Springeria stenosoma is considered as questionably valid but with further investigation into generic placement required. The validity of species with SCSFRI type specimens not examined in this study are also briefly discussed.

  14. Produção do híbrido "cachadia" em diferentes densidades de estocagem em sistema de recirculação de água

    Directory of Open Access Journals (Sweden)

    P.M.C Faria

    2011-10-01

    Full Text Available Avaliou-se o efeito da densidade de estocagem na produção de "cachadia" (Pseudoplatystoma fasciatum x Leiarius marmoratus em sistema de recirculação de água. Nas duas primeiras fases, com duração de 27 e 40 dias e usando animais com média de peso inicial de 31 e 57g, respectivamente, foram testados 20, 40, 60 e 80 peixes/m³. Na terceira e quarta fase, usando peixes com média de peso de 169 e 399g durante 41 e 99 dias, respectivamente, foram testados 10, 20, 30 e 40 peixes/m³. A taxa de sobrevivência foi acima de 92%, sem diferenças significativas entre tratamentos. Verificou-se redução no ganho de peso diário com redução com o incremento da densidade na segunda e na quarta fase experimental. A biomassa final apresentou relação direta com a densidade em todas as fases. Taxas de conversão alimentar entre 0,8 e 1,3:1 foram registradas. O "cachadia" atingiu 1,1kg em 207 dias de cultivo, mostrando-se promissor para a piscicultura intensiva.

  15. Profile of micronucleus frequencies and nuclear abnormalities in different species of electric fishes (Gymnotiformes) from the Eastern Amazon.

    Science.gov (United States)

    Melo, Karina Motta; Alves, Ingrid Reale; Pieczarka, Julio Cesar; de Oliveira David, José Augusto; Nagamachi, Cleusa Yoshiko; Grisolia, Cesar Koppe

    2013-09-01

    The frequency of spontaneous micronucleus (MN) formation in fish species needs to be determined to evaluate their usefulness for genotoxic biomonitoring. The definition of a good bioindicator takes into account the current knowledge of its metabolic traits as well as other factors including its feeding behavior and relationship to the environment. In this study, we compared the basal frequencies of micronucleated erythrocytes and nuclear abnormalities (NA) among different species of the fish Order Gymnotiformes (Rhamphichthys marmoratus, Steatogenys elegans, Sternopygus macrurus, Parapteronotus hasemani, Gymnotus mamiraua, Gymnotus arapaima, Brachyhypopomus beebei, Brachyhypopomus n. sp. BENN) sampled in several localities of the Eastern Amazon. A baseline of MN and NA frequency in these fish was determined, enabling the identification of potentially useful species as models for genotoxicity studies. Only one impacted sample collected at a site in the River Caripetuba showed a significant number of NAs, which may be due to the release of wastewater by neighbouring mining industries and by the burnt fuel released by the small boats used by a local community. Our results may provide support for further studies in areas of the Eastern Amazon affected by mining, deforestation and other anthropogenic activities.

  16. Profile of micronucleus frequencies and nuclear abnormalities in different species of electric fishes (Gymnotiformes from the Eastern Amazon

    Directory of Open Access Journals (Sweden)

    Karina Motta Melo

    2013-01-01

    Full Text Available The frequency of spontaneous micronucleus (MN formation in fish species needs to be determined to evaluate their usefulness for genotoxic biomonitoring. The definition of a good bioindicator takes into account the current knowledge of its metabolic traits as well as other factors including its feeding behavior and relationship to the environment. In this study, we compared the basal frequencies of micronucleated erythrocytes and nuclear abnormalities (NA among different species of the fish Order Gymnotiformes (Rhamphichthys marmoratus, Steatogenys elegans, Sternopygus macrurus, Parapteronotus hasemani, Gymnotus mamiraua, Gymnotus arapaima, Brachyhypopomus beebei, Brachyhypopomus n. sp. BENN sampled in several localities of the Eastern Amazon. A baseline of MN and NA frequency in these fish was determined, enabling the identification of potentially useful species as models for genotoxicity studies. Only one impacted sample collected at a site in the River Caripetuba showed a significant number of NAs, which may be due to the release of wastewater by neighbouring mining industries and by the burnt fuel released by the small boats used by a local community. Our results may provide support for further studies in areas of the Eastern Amazon affected by mining, deforestation and other anthropogenic activities.

  17. DDT and Derivatives in Indicator Species of the Aquatic Food Web of Rangsit Agricultural Area, Central Thailand

    Science.gov (United States)

    Siriwong, W.; Thirakhupt, K.; Sitticharoenchai, D.; Rohitrattana, J.; Thongkongowm, P.; Borjan, M.; Robson, M.

    2009-01-01

    The presence of DDT and derivatives in the food web of freshwater ecosystems of Rangsit agricultural area, Pathum Thani Province, Thailand were investigated from June 2004 to May 2007. By using gas chromatography (GC) with micro electron capture detector (μ ECD), DDT and derivatives in water, sediment, and fifteen indicator species i.e., 2 producers; Eichhornia crassipes and plankton (phyto- and zoo- plankton), an herbivore; Trichogaster microlepis (3) 3 omnivores; Trichogaster trichopterus, Oreochromis niloticus, and Puntius gonionotus, 6 carnivores; Channa striatus, Oxyeleotris marmoratus, Macrognathus siamensis, Parambassis siamensis, Anabas testudineus, and Pristolepis fasciatus, and 3 detritivores; Macrobrachium lanchesteri, Pomacea sp., and Filopaludina mertensi were measured. Results show low concentration levels (part per billion) of DDT & derivatives in each food web compartment i.e. water, sediment, aquatic plant, plankton, fish, and invertebrates. Magnification patterns, i.e. bioconcentration, bioaccumulation, and biomagnification, based on habitat and foraging behavior of selected freshwater species indicates that DDT & derivatives can accumulate and be magnified through the food chain from the lowest up to the highest trophic level. Therefore, the presence of residues and the evidence of magnification patterns can be observed as ecological indicators for evaluating ecological health risk. PMID:20161116

  18. Studi keanekaragaman reptil dan amfibi di kawasan ekowisata Linggo Asri, Pekalongan, Provinsi Jawa Tengah

    Directory of Open Access Journals (Sweden)

    Rury Eprilurahman

    2012-02-01

    Full Text Available Penelitian keanekaragaman dan kemelimpahan herpetofauna telah dilakukan dalam upaya mendukung kelestarian herpetofauna di kawasan ekowisata Linggo Asri. Penelitian ini dilaksanakan pada tanggal 10–23 Juli 2009 secara aktif nokturnal dan diurnal dengan menggunakan metode purpossive sampling yang terpusat di empat lokasi kajian. Selanjutnya hasil yang diperoleh dianalaisis menggunakan indeks keanekaragaman Shanon & Wiener dan indeks kemerataan Simpson. Total telah ditemukan sebanyak 20 jenis herpetofauna terdiri atas 10 jenis amfibia, 7 jenis lasertilia dan 3 jenis ophidia. Jenis tersebut antara lain yaitu: Fejervarya limnocharis,Fejervarya cancrivora, Occydozyga sumatrana, Occydozyga lima, Hylarana chalconota, Huia masonii, Limnonectes macrodon,Microhyla achatina, Phrynoidis aspera, Polypedates leucomystax, Bronchocela jubata, Eutropis multifasciata, Dasia olivacea,Hemidactylus platyurus, Hemidactylus frenatus, Hemidactylus garnoti, Cyrtodactylus marmoratus, Ahaetula prasina, Oligodonpurpurascens, dan Rhabdophis chrysargos. Diketahui dari jenis-jenis tersebut dua jenis yaitu Huia masonii dan Microhyla achatina merupakan endemik Jawa. Hasil analisis didapatkan nilai indeks keanekeragaman sebesar 2,93 di mana tergolong tinggi. Sedangkan indeks kemerataan sebesar 0,43 yang menandakan persebaran herpetofauna di kawasan ekowisata Linggo Asri tidak merata dan terkonsentrasi beberapa titik. Tipe vegetasi dan ketinggian tempat merupakan faktor ekologi utama yang mempengaruhi penyebaran herpetofauna di kawasan ekowisata Linggo Asri.

  19. Permanent Genetic Resources added to Molecular Ecology Resources database 1 January 2009-30 April 2009.

    Science.gov (United States)

    Abercrombie, L G; Anderson, C M; Baldwin, B G; Bang, I C; Beldade, R; Bernardi, G; Boubou, A; Branca, A; Bretagnolle, F; Bruford, M W; Buonamici, A; Burnett, R K; Canal, D; Cárdenas, H; Caullet, C; Chen, S Y; Chun, Y J; Cossu, C; Crane, C F; Cros-Arteil, S; Cudney-Bueno, R; Danti, R; Dávila, J A; Della Rocca, G; Dobata, S; Dunkle, L D; Dupas, S; Faure, N; Ferrero, M E; Fumanal, B; Gigot, G; González, I; Goodwin, S B; Groth, D; Hardesty, B D; Hasegawa, E; Hoffman, E A; Hou, M L; Jamsari, A F J; Ji, H J; Johnson, D H; Joseph, L; Justy, F; Kang, E J; Kaufmann, B; Kim, K S; Kim, W J; Koehler, A V; Laitung, B; Latch, P; Liu, Y D; Manjerovic, M B; Martel, E; Metcalfe, S S; Miller, J N; Midgley, J J; Migeon, A; Moore, A J; Moore, W L; Morris, V R F; Navajas, M; Navia, D; Neel, M C; De Nova, P J G; Olivieri, I; Omura, T; Othman, A S; Oudot-Canaff, J; Panthee, D R; Parkinson, C L; Patimah, I; Pérez-Galindo, C A; Pettengill, J B; Pfautsch, S; Piola, F; Potti, J; Poulin, R; Raimondi, P T; Rinehart, T A; Ruzainah, A; Sarver, S K; Scheffler, B E; Schneider, A R R; Silvain, J F; Siti Azizah, M N; Springer, Y P; Stewart, C N; Sun, W; Tiedemann, R; Tsuji, K; Trigiano, R N; Vendramin, G G; Wadl, P A; Wang, L; Wang, X; Watanabe, K; Waterman, J M; Weisser, W W; Westcott, D A; Wiesner, K R; Xu, X F; Yaegashi, S; Yuan, J S

    2009-09-01

    This article documents the addition of 283 microsatellite marker loci to the Molecular Ecology Resources Database. Loci were developed for the following species: Agalinis acuta; Ambrosia artemisiifolia; Berula erecta; Casuarius casuarius; Cercospora zeae-maydis; Chorthippus parallelus; Conyza canadensis; Cotesia sesamiae; Epinephelus acanthistius; Ficedula hypoleuca; Grindelia hirsutula; Guadua angustifolia; Leucadendron rubrum; Maritrema novaezealandensis; Meretrix meretrix; Nilaparvata lugens; Oxyeleotris marmoratus; Phoxinus neogaeus; Pristomyrmex punctatus; Pseudobagrus brevicorpus; Seiridium cardinale; Stenopsyche marmorata; Tetranychus evansi and Xerus inauris. These loci were cross-tested on the following species: Agalinis decemloba; Agalinis tenella; Agalinis obtusifolia; Agalinis setacea; Agalinis skinneriana; Cercospora zeina; Cercospora kikuchii; Cercospora sorghi; Mycosphaerella graminicola; Setosphaeria turcica; Magnaporthe oryzae; Cotesia flavipes; Cotesia marginiventris; Grindelia Xpaludosa; Grindelia chiloensis; Grindelia fastigiata; Grindelia lanceolata; Grindelia squarrosa; Leucadendron coniferum; Leucadendron salicifolium; Leucadendron tinctum; Leucadendron meridianum; Laodelphax striatellus; Sogatella furcifera; Phoxinus eos; Phoxinus rigidus; Phoxinus brevispinosus; Phoxinus bicolor; Tetranychus urticae; Tetranychus turkestani; Tetranychus ludeni; Tetranychus neocaledonicus; Tetranychus amicus; Amphitetranychus viennensis; Eotetranychus rubiphilus; Eotetranychus tiliarium; Oligonychus perseae; Panonychus citri; Bryobia rubrioculus; Schizonobia bundi; Petrobia harti; Xerus princeps; Spermophilus tridecemlineatus and Sciurus carolinensis. © 2009 Blackwell Publishing Ltd.

  20. Status and trend of the Kittlitz's Murrelet Brachyramphus brevirostris in Glacier Bay, Alaska

    Science.gov (United States)

    Piatt, John F.; Arimitsu, M.; Drew, G.; Madison, E.N.; Bodkin, J.; Romano, Marc D.

    2011-01-01

    We conducted standardized surveys for marine birds in Glacier Bay in seven years between 1991 and 2008. From our most recent survey, a combination of line- and strip-transect methods completed in 2008, we estimated that 4981 (95% CI 1293-8670) Kittlitz's Murrelets Brachyramphus brevirostris resided in Glacier Bay during the month of June, together with 12 195 (5607-18 783) Marbled Murrelets B. marmoratus. When counts were prorated to assign unidentified Brachyramphus murrelets to species, population estimates increased to 5641 Kittlitz's Murrelets and 13 810 Marbled Murrelets. Our surveys of bird numbers in Glacier Bay between 1991 and 2008 revealed that Kittlitz's Murrelet declined by ???85% during this period. Trend analysis suggested a rate of decline between -10.7% and -14.4% per year. No direct human impacts (e.g., bycatch, oil pollution, vessel disturbance) in our study area could fully account for a decline of this magnitude. Widespread declines of Brachyramphus murrelets and Harbor Seals Phoca vitulina in the Gulf of Alaska during the 1980s-1990s suggest large-scale influences on these marine predators, perhaps related to climate-mediated cycles in food supply. Other natural factors that may impact Glacier Bay populations include predation by avian and terrestrial predators, widespread glacial retreat and its effect on nesting and foraging habitats, and competition for food with marine predators whose abundance in Glacier Bay has increased markedly in recent years (Humpback Whales Megaptera novaeangliae and Steller Sea Lions Eumetopias jubatus).

  1. Determining individual variation in growth and its implication for life-history and population processes using the empirical Bayes method.

    Directory of Open Access Journals (Sweden)

    Simone Vincenzi

    2014-09-01

    Full Text Available The differences in demographic and life-history processes between organisms living in the same population have important consequences for ecological and evolutionary dynamics. Modern statistical and computational methods allow the investigation of individual and shared (among homogeneous groups determinants of the observed variation in growth. We use an Empirical Bayes approach to estimate individual and shared variation in somatic growth using a von Bertalanffy growth model with random effects. To illustrate the power and generality of the method, we consider two populations of marble trout Salmo marmoratus living in Slovenian streams, where individually tagged fish have been sampled for more than 15 years. We use year-of-birth cohort, population density during the first year of life, and individual random effects as potential predictors of the von Bertalanffy growth function's parameters k (rate of growth and L∞ (asymptotic size. Our results showed that size ranks were largely maintained throughout marble trout lifetime in both populations. According to the Akaike Information Criterion (AIC, the best models showed different growth patterns for year-of-birth cohorts as well as the existence of substantial individual variation in growth trajectories after accounting for the cohort effect. For both populations, models including density during the first year of life showed that growth tended to decrease with increasing population density early in life. Model validation showed that predictions of individual growth trajectories using the random-effects model were more accurate than predictions based on mean size-at-age of fish.

  2. Male Armaments and Reproductive Behavior in “Nutcracker” Camel Crickets (Rhaphidophoridae, Pristoceuthophilus

    Directory of Open Access Journals (Sweden)

    Lauren P. Conroy

    2015-01-01

    Full Text Available Males of many species possess striking weaponry used in intrasexual competition for access to females. Until recently, there were no known cases of male weaponry being used against females in sexual coercion. However, in the camel cricket, Pristoceuthophilus marmoratus, males use modified hind legs to fight with each other and also to trap females and force them to copulate. To determine whether hind leg armaments serve similar fighting and mating functions in morphologically similar congeners, we performed a comparative survey of armament use in intra- and inter-sexual interactions in four additional species of Pristoceuthophilus (P. arizonae and three undescribed species: P. ‘Huachuca summer,’ P. ‘Madera’ and P. ‘Mt. Pinos’. Intrasexual leg fighting occurred in all species for which trials were performed, and hints of sexual coercion occurred in two species (P. ‘Huachuca summer’ and P. ‘Mt. Pinos’, suggesting additional cases of a uniquely dual-purpose armament. These findings suggest an evolutionary exaptation of hind leg armaments in this genus, wherein an intrasexual fighting weapon took on a secondary function of sexual coercion.

  3. Male Armaments and Reproductive Behavior in “Nutcracker” Camel Crickets (Rhaphidophoridae, Pristoceuthophilus)

    Science.gov (United States)

    Conroy, Lauren P.; Gray, David A.

    2015-01-01

    Males of many species possess striking weaponry used in intrasexual competition for access to females. Until recently, there were no known cases of male weaponry being used against females in sexual coercion. However, in the camel cricket, Pristoceuthophilus marmoratus, males use modified hind legs to fight with each other and also to trap females and force them to copulate. To determine whether hind leg armaments serve similar fighting and mating functions in morphologically similar congeners, we performed a comparative survey of armament use in intra- and inter-sexual interactions in four additional species of Pristoceuthophilus (P. arizonae and three undescribed species: P. ‘Huachuca summer,’ P. ‘Madera’ and P. ‘Mt. Pinos’). Intrasexual leg fighting occurred in all species for which trials were performed, and hints of sexual coercion occurred in two species (P. ‘Huachuca summer’ and P. ‘Mt. Pinos’), suggesting additional cases of a uniquely dual-purpose armament. These findings suggest an evolutionary exaptation of hind leg armaments in this genus, wherein an intrasexual fighting weapon took on a secondary function of sexual coercion. PMID:26463067

  4. Male Armaments and Reproductive Behavior in "Nutcracker" Camel Crickets (Rhaphidophoridae, Pristoceuthophilus).

    Science.gov (United States)

    Conroy, Lauren P; Gray, David A

    2015-01-07

    Males of many species possess striking weaponry used in intrasexual competition for access to females. Until recently, there were no known cases of male weaponry being used against females in sexual coercion. However, in the camel cricket, Pristoceuthophilus marmoratus, males use modified hind legs to fight with each other and also to trap females and force them to copulate. To determine whether hind leg armaments serve similar fighting and mating functions in morphologically similar congeners, we performed a comparative survey of armament use in intra- and inter-sexual interactions in four additional species of Pristoceuthophilus (P. arizonae and three undescribed species: P. 'Huachuca summer,' P. 'Madera' and P. 'Mt. Pinos'). Intrasexual leg fighting occurred in all species for which trials were performed, and hints of sexual coercion occurred in two species (P. 'Huachuca summer' and P. 'Mt. Pinos'), suggesting additional cases of a uniquely dual-purpose armament. These findings suggest an evolutionary exaptation of hind leg armaments in this genus, wherein an intrasexual fighting weapon took on a secondary function of sexual coercion.

  5. The life cycle of Prosorhynchoides carvajali (Trematoda: Bucephalidae) involving species of bivalve and fish hosts in the intertidal zone of central Chile.

    Science.gov (United States)

    Muñoz, G; Valdivia, I; López, Z

    2015-09-01

    We describe the life cycle of the bucephalid Prosorhynchoides carvajali from the intertidal rocky zone of central Chile. To elucidate the life cycle of this digenean, two mytilid bivalves, Semimytilus algosus and Perumytilus purpuratus, and ten intertidal fish species belonging to the families Blenniidae, Tripterygiidae, Labrisomidae, Kyphosidae and Gobiesocidae were analysed for natural infections. In addition, experimental infections of fish were undertaken and molecular analyses were performed of several developmental stages of the digeneans in various host species. Experimental infections of fish were made from infected mytilids to determine which fish species were suitable for the metacercarial stage of Prosorhynchoides. We also determined the abundance and prevalence of metacercariae in natural infections in fish and found that they were lower than in the experimental infections. A molecular analysis showed that sporocysts from S. algosus were identical to metacercariae from five fish species and P. carvajali adults. Sporocysts isolated from P. purpuratus were similar to metacercaria found in one fish species only (G. laevifrons) but were different from P. carvajali, with 1.9-2.0% genetic divergence. Therefore, the complete life cycle of P. carvajali consists of the mytilid species S. algosus as the first intermediate host, at least five intertidal fish species as second intermediate hosts (Scartichthys viridis, Auchenionchus microcirrhis, Hypsoblennius sordidus, Helcogrammoides chilensis and Gobiesox marmoratus), two carnivorous fish as definitive hosts (Auchenionchus microcirrhis and A. variolosus) and one occasional definitive host (Syciases sanguineus). This is the second description of a life cycle of a marine digenean from Chile.

  6. In Vitro and in Vivo Anticancer Activity of Pardaxin against Proliferation and Growth of Oral Squamous Cell Carcinoma

    Directory of Open Access Journals (Sweden)

    Yifan Han

    2015-12-01

    Full Text Available Pardaxin (H-GFFALIPKIISSPLFKTLLSAVGSALSSSGGQE-OH, a 33-amino-acid polypeptide, is an antimicrobial peptide (AMP isolated from the marine fish species Pardachirus marmoratus. Pardaxin shows antibacterial and antitumor activities. However, pardaxin-induced inhibition of oral cancer and the mechanism of tumor reduction in buccal pouch carcinogenesis after pardaxin painting remain undetermined. Additionally, the toxic effects of pardaxin on normal tissue remain unclear. The present study investigated the anticancer activity of pardaxin in oral squamous cell carcinoma (OSCC cells in the hamster buccal pouch model with or without 7,12-dimethylbenz[a]anthracene (DMBA pretreatment. This is the first study to confirm the effects of pardaxin on normal tissue and its nontoxic effects in vivo. Cell viability assays and colony formation tests in OSCC cell lines (SCC-4 demonstrated that pardaxin reduced cell viability in a dose-dependent manner. Immunofluorescence staining of cleaved caspase-3 in SCC-4 cells revealed that expression of activated caspase-3 in SCC-4 cells significantly increased after 24-h treatment with pardaxin. Additionally, a cell cycle analysis indicated that pardaxin treatment resulted in the cell cycle arrest of SCC-4 cells in the G2/M phase, thereby limiting cell proliferation. Furthermore, pardaxin treatment substantially alleviated carcinogenesis in the DMBA-induced hamster buccal pouch model by lowering prostaglandin E2 levels. These results suggest that pardaxin is a potential marine drug for adjuvant chemotherapy for human OSCC and oral cancer.

  7. Taxonomic revision of the South American catfish genus Ageneiosus (Siluriformes: Auchenipteridae) with the description of four new species

    Science.gov (United States)

    Ribeiro, Frank R.V.; Rapp Py-Daniel, Lúcia H.; Walsh, Stephen J.

    2017-01-01

    The catfish genus Ageneiosus in the exclusively Neotropical family Auchenipteridae is revised. Species of Ageneiosus are widely distributed in all major South American continental drainages except the São Francisco River basin and small rivers along the Brazilian east coast. The taxonomic revision was based on examination of available type specimens, additional museum material and comparisons of original descriptions. A suite of morphometric, meristic and qualitative characters of internal and external anatomy were used to diagnose valid species and determine synonyms. Thirteen valid species are recognized in the genus Ageneiosus, some of which are widely distributed across South America. Ageneiosus pardalis is the only trans-Andean species in the genus. Ageneiosus polystictus and Ageneiosus uranophthalmus are more widely distributed than previously reported. Ageneiosus marmoratus is a junior synonym of Ageneiosus inermis. Ageneiosus dentatus is a valid species and its name is removed from the synonymy of Ageneiosus ucayalensis. Four new species are described: Ageneiosus akamai, Ageneiosus apiaka, Ageneiosus intrusus and Ageneiosus lineatus, all from the Amazon River basin. A dichotomous key for all 13 valid species of Ageneiosus species is provided.

  8. Fighting experience alters brain androgen receptor expression dependent on testosterone status

    Science.gov (United States)

    Li, Cheng-Yu; Earley, Ryan L.; Huang, Shu-Ping; Hsu, Yuying

    2014-01-01

    Contest decisions are influenced by the outcomes of recent fights (winner–loser effects). Steroid hormones and serotonin are closely associated with aggression and therefore probably also play important roles in mediating winner–loser effects. In mangrove rivulus fish, Kryptolebias marmoratus, individuals with higher testosterone (T), 11-ketotestosterone and cortisol levels are more capable of winning, but titres of these hormones do not directly mediate winner–loser effects. In this study, we investigated the effects of winning/losing experiences on brain expression levels of the receptor genes for androgen (AR), oestrogen α/β (ERα/β), glucocorticoid (GR) and serotonin (5-HT1AR). The effect of contest experience on AR gene expression depended on T levels: repeated losses decreased, whereas repeated wins increased AR gene expression in individuals with low T but not in individuals with medium or high T levels. These results lend strong support for AR being involved in mediating winner–loser effects, which, in previous studies, were more detectable in individuals with lower T. Furthermore, the expression levels of ERα/β, 5-HT1AR and GR genes were higher in individuals that initiated contests against larger opponents than in those that did not. Overall, contest experience, underlying endocrine state and hormone and serotonin receptor expression patterns interacted to modulate contest decisions jointly. PMID:25320171

  9. Artificial barriers prevent genetic recovery of small isolated populations of a low-mobility freshwater fish.

    Science.gov (United States)

    Coleman, R A; Gauffre, B; Pavlova, A; Beheregaray, L B; Kearns, J; Lyon, J; Sasaki, M; Leblois, R; Sgro, C; Sunnucks, P

    2018-01-12

    Habitat loss and fragmentation often result in small, isolated populations vulnerable to environmental disturbance and loss of genetic diversity. Low genetic diversity can increase extinction risk of small populations by elevating inbreeding and inbreeding depression, and reducing adaptive potential. Due to their linear nature and extensive use by humans, freshwater ecosystems are especially vulnerable to habitat loss and fragmentation. Although the effects of fragmentation on genetic structure have been extensively studied in migratory fishes, they are less understood in low-mobility species. We estimated impacts of instream barriers on genetic structure and diversity of the low-mobility river blackfish (Gadopsis marmoratus) within five streams separated by weirs or dams constructed 45-120 years ago. We found evidence of small-scale (barriers, as expected for a fish with low mobility. Genetic diversity was lower above barriers in small streams only, regardless of barrier age. In particular, one isolated population showed evidence of a recent bottleneck and inbreeding. Differentiation above and below the barrier (F ST  = 0.13) was greatest in this stream, but in other streams did not differ from background levels. Spatially explicit simulations suggest that short-term barrier effects would not be detected with our data set unless effective population sizes were very small (barriers is reduced and requires more genetic markers compared to panmictic populations. We also demonstrate the importance of accounting for natural population genetic structure in fragmentation studies.

  10. A Study of lymphangiogenesis in a gecko model of tail autotomy

    International Nuclear Information System (INIS)

    Tsopelas, C.; Munns, S.L.; Lewis, B.; Daniels, C.B.; Cooter, R.D.; Chatterton, B.E.

    2002-01-01

    Full text: Lymphoedema is a debilitating problem for which there is no effective cure. Lymphatic vessels do not regenerate after injuries such as infection, trauma, radiotherapy or tumour invasion. One approach is to determine whether lymph vessels can be regenerated in tissues where these structures have been damaged or removed. This study examined lymphangiogenesis in a gecko model of tail autotomy. Christinus marmoratus can regenerate its tail which is non-oedematous. The lymphatics of gecko tails were visualised using 99m Tc-Sb 2 S 3 colloid, image analyses provided lymph speed and % activity migrated from the injection site. Histological images yielded density and diameter of lymphatic vessels. Measurements were obtained for geckos with non-regenerate tails, 3,6, 9,12, 15, 18 and >24 week (fully) old regenerated tails post autotomy (pa). Fully regenerated tails had significantly slower lymph speed, slower radiocolloid migration from injection site, lower lymphatic density and higher diameter of lymphatic vessels, than similar sized geckos with non-regenerate tails. Their comparison to 6-18 week old tails, confirmed no significant difference in lymph speed, radiocolloid migration or diameter of lymphatic vessels. No measurable lymphatic flow was seen at 3 weeks pa. A functional lymphatic network was established in regenerating gecko tails, where a combination of data elude to a critical lymphangiogenesis period during 3-6 weeks post autotomy. Copyright (2002) The Australian and New Zealand Society of Nuclear Medicine Inc

  11. Modeling habitat for Marbled Murrelets on the Siuslaw National Forest, Oregon, using lidar data

    Science.gov (United States)

    Hagar, Joan C.; Aragon, Ramiro; Haggerty, Patricia; Hollenbeck, Jeff P.

    2018-03-28

    Habitat models using lidar-derived variables that quantify fine-scale variation in vegetation structure can improve the accuracy of occupancy estimates for canopy-dwelling species over models that use variables derived from other remote sensing techniques. However, the ability of models developed at such a fine spatial scale to maintain accuracy at regional or larger spatial scales has not been tested. We tested the transferability of a lidar-based habitat model for the threatened Marbled Murrelet (Brachyramphus marmoratus) between two management districts within a larger regional conservation zone in coastal western Oregon. We compared the performance of the transferred model against models developed with data from the application location. The transferred model had good discrimination (AUC = 0.73) at the application location, and model performance was further improved by fitting the original model with coefficients from the application location dataset (AUC = 0.79). However, the model selection procedure indicated that neither of these transferred models were considered competitive with a model trained on local data. The new model trained on data from the application location resulted in the selection of a slightly different set of lidar metrics from the original model, but both transferred and locally trained models consistently indicated positive relationships between the probability of occupancy and lidar measures of canopy structural complexity. We conclude that while the locally trained model had superior performance for local application, the transferred model could reasonably be applied to the entire conservation zone.

  12. A Bayesian Approach to Inferring Rates of Selfing and Locus-Specific Mutation.

    Science.gov (United States)

    Redelings, Benjamin D; Kumagai, Seiji; Tatarenkov, Andrey; Wang, Liuyang; Sakai, Ann K; Weller, Stephen G; Culley, Theresa M; Avise, John C; Uyenoyama, Marcy K

    2015-11-01

    We present a Bayesian method for characterizing the mating system of populations reproducing through a mixture of self-fertilization and random outcrossing. Our method uses patterns of genetic variation across the genome as a basis for inference about reproduction under pure hermaphroditism, gynodioecy, and a model developed to describe the self-fertilizing killifish Kryptolebias marmoratus. We extend the standard coalescence model to accommodate these mating systems, accounting explicitly for multilocus identity disequilibrium, inbreeding depression, and variation in fertility among mating types. We incorporate the Ewens sampling formula (ESF) under the infinite-alleles model of mutation to obtain a novel expression for the likelihood of mating system parameters. Our Markov chain Monte Carlo (MCMC) algorithm assigns locus-specific mutation rates, drawn from a common mutation rate distribution that is itself estimated from the data using a Dirichlet process prior model. Our sampler is designed to accommodate additional information, including observations pertaining to the sex ratio, the intensity of inbreeding depression, and other aspects of reproduction. It can provide joint posterior distributions for the population-wide proportion of uniparental individuals, locus-specific mutation rates, and the number of generations since the most recent outcrossing event for each sampled individual. Further, estimation of all basic parameters of a given model permits estimation of functions of those parameters, including the proportion of the gene pool contributed by each sex and relative effective numbers. Copyright © 2015 by the Genetics Society of America.

  13. Eficacia del control de larvas de vectores de la malaria con peces larvívoros nativos en San Martín, Perú

    Directory of Open Access Journals (Sweden)

    Elmer Rojas P

    2004-01-01

    Full Text Available Objetivo: Determinar la eficacia del control larvario de vectores de la malaria con peces larvívoros nativos en San Martín, Perú. Material y métodos: Estudio experimental que se llevó a cabo en las localidades de Yumbatos, Alianza y San Juan de Shanusi con ocho criaderos cada uno, identificándose las especies nativas Rivulus urophtalmus "chuina" y Pyrrulina brevis "achualillo" comparados con la eficacia ejercida por Poecilia reticulata "guppy". Se midieron variables como temperatura, pH, concentración de electrolitos en el agua, densidad de los peces y presencia de otros depredadores. Resultados: Los peces nativos alcanzaron una eficacia de 98% en el control de larvas de Anopheles, cuando se mantuvieron en densidades entre 10 y 15 peces/m²; estos peces alcanzan longitudes hasta de 8 cm, y tienen similar o mayor voracidad que Poecilia reticulata. Asimismo, se evidenció la existencia de peces depredadores, Hoplias malabaricus "fasaco" y Simbranchus marmoratus "atinga", los que se alimentan de estos peces pequeños. Conclusiones: Los peces nativos son eficaces para el control de larvas de Anopheles; asimismo, se deben tener en cuenta la existencia de otras especies depredadoras, así como la limpieza de la maleza de los criaderos para incrementar la eficacia del control.

  14. Ready for a fight? The physiological effects of detecting an opponent's pheromone cues prior to a contest.

    Science.gov (United States)

    Garcia, Mark J; Williams, John; Sinderman, Benjamin; Earley, Ryan L

    2015-10-01

    Reception of pheromone cues can elicit significant physiological (e.g. steroid hormone levels) changes in the recipient. These pheromone-induced physiological changes have been well documented for male-female interactions, but scarcely in same-sex interactions (male-male and female-female). We sought to address this dearth in the current literature and examine whether mangrove rivulus fish (Kryptolebias marmoratus) could detect and, ultimately, mount a physiological response to the pheromone signature of a potential, same-sex competitor. We examined steroid hormone levels in mangrove rivulus exposed to one of three treatments: 1) isolation, 2) exposure to pheromones of a size-matched partner, and 3) pheromone exposure to a size-matched opponent followed by a physical encounter with the opponent. We found that exposure to a competitor's pheromone cues elicited a significant increase in testosterone levels. Increases in testosterone were similar across genetically distinct lineages derived from geographically distinct populations. Further, testosterone levels were similar between individuals only exposed to pheromone cues and individuals exposed to both pheromone cues and a subsequent physical encounter. Our findings led us to generate a number of testable predictions regarding how mangrove rivulus utilize pheromone signals in social interactions, the molecular mechanisms linking social stimuli and hormonal responses, and the possible adaptive benefits of hormonal responsiveness to receiving a potential competitor's pheromone cues. Copyright © 2015 Elsevier Inc. All rights reserved.

  15. Model development of dust emission and heterogeneous chemistry within the Community Multiscale Air Quality modeling system and its application over East Asia

    Directory of Open Access Journals (Sweden)

    X. Dong

    2016-07-01

    Full Text Available The Community Multiscale Air Quality (CMAQ model has been further developed in terms of simulating natural wind-blown dust in this study, with a series of modifications aimed at improving the model's capability to predict the emission, transport, and chemical reactions of dust. The default parameterization of initial threshold friction velocity constants are revised to correct the double counting of the impact of soil moisture in CMAQ by the reanalysis of field experiment data; source-dependent speciation profiles for dust emission are derived based on local measurements for the Gobi and Taklamakan deserts in East Asia; and dust heterogeneous chemistry is also implemented. The improved dust module in the CMAQ is applied over East Asia for March and April from 2006 to 2010. The model evaluation result shows that the simulation bias of PM10 and aerosol optical depth (AOD is reduced, respectively, from −55.42 and −31.97 % by the original CMAQ to −16.05 and −22.1 % by the revised CMAQ. Comparison with observations at the nearby Gobi stations of Duolun and Yulin indicates that applying a source-dependent profile helps reduce simulation bias for trace metals. Implementing heterogeneous chemistry also results in better agreement with observations for sulfur dioxide (SO2, sulfate (SO42−, nitric acid (HNO3, nitrous oxides (NOx, and nitrate (NO3−. The investigation of a severe dust storm episode from 19 to 21 March 2010 suggests that the revised CMAQ is capable of capturing the spatial distribution and temporal variation of dust. The model evaluation also indicates potential uncertainty within the excessive soil moisture used by meteorological simulation. The mass contribution of fine-mode particles in dust emission may be underestimated by 50 %. The revised CMAQ model provides a useful tool for future studies to investigate the emission, transport, and impact of wind-blown dust over East Asia and elsewhere.

  16. Predator diversity effects in an exotic freshwater food web.

    Science.gov (United States)

    Naddafi, Rahmat; Rudstam, Lars G

    2013-01-01

    Cascading trophic interactions are often defined as the indirect effects of a predator on primary producers through the effect of the predator on herbivores. These effects can be both direct through removal of herbivores [density-mediated indirect interactions (DMIIs)] or indirect through changes in the behavior of the herbivores [trait-mediated indirect interactions (TMIIs)]. How the relative importance of these two indirect interactions varies with predator diversity remains poorly understood. We tested the effect of predator diversity on both TMIIs and DMIIs on phytoplankton using two competitive invasive dreissenid mussel species (zebra mussel and quagga mussel) as the herbivores and combinations of one, two or all three species of the predators pumpkinseed sunfish, round goby, and rusty crayfish. Predators had either direct access to mussels and induced both TMII and DMII, or no direct access and induced only TMII through the presence of risk cues. In both sets of treatments, the predators induced a trophic cascade which resulted in more phytoplankton remaining with predators present than with only mussels present. The trophic cascade was weaker in three-predator and two-predator treatments than in one-predator treatments when predators had direct access to dreissenids (DMIIs and TMIIs). Crayfish had higher cascading effects on phytoplankton than both pumpkinseed and round goby. Increased predator diversity decreased the strength of DMIIs but had no effect on the strength of TMIIs. The strength of TMIIs was higher with zebra than quagga mussels. Our study suggests that inter-specific interference among predators in multi-species treatments weakens the consumptive cascading effects of predation on lower trophic levels whereas the importance of predator diversity on trait mediated effects depends on predator identity.

  17. A protocol to correct for intra- and interspecific variation in tail hair growth to align isotope signatures of segmentally cut tail hair to a common time line.

    Science.gov (United States)

    Burnik Šturm, Martina; Pukazhenthi, Budhan; Reed, Dolores; Ganbaatar, Oyunsaikhan; Sušnik, Stane; Haymerle, Agnes; Voigt, Christian C; Kaczensky, Petra

    2015-06-15

    In recent years, segmental stable isotope analysis of hair has been a focus of research in animal dietary ecology and migration. To correctly assign tail hair segments to seasons or even Julian dates, information on tail hair growth rates is a key parameter, but is lacking for most species. We (a) reviewed the literature on tail hair growth rates in mammals; b) made own measurements of three captive equid species; (c) measured δ(2)H, δ(13)C and δ(15)N values in sequentially cut tail hairs of three sympatric, free-ranging equids from the Mongolian Gobi, using isotope ratio mass spectrometry (IRMS); and (d) collected environmental background data on seasonal variation by measuring δ(2)H values in precipitation by IRMS and by compiling pasture productivity measured by remote sensing via the normalized difference vegetation index (NDVI). Tail hair growth rates showed significant inter- and intra-specific variation making temporal alignment problematic. In the Mongolian Gobi, high seasonal variation of δ(2)H values in precipitation results in winter lows and summer highs of δ(2)H values of available water sources. In water-dependent equids, this seasonality is reflected in the isotope signatures of sequentially cut tails hairs. In regions which are subject to strong seasonal patterns we suggest identifying key isotopes which show strong seasonal variation in the environment and can be expected to be reflected in the animal tissue. The known interval between the maxima and minima of these isotope values can then be used to correctly temporally align the segmental stable isotope signature for each individual animal. © 2015 The Authors. Rapid Communications in Mass Spectrometry published by John Wiley & Sons Ltd.

  18. Browning in Desert Boundaries in Asia in Recent Decades

    Science.gov (United States)

    Jeong, Su-Jong; Ho, Chang-Hoi; Brown, Molly E.; Kug, Jong-Seong; Piao, Shilong

    2011-01-01

    In this study, the changes in desert boundaries in Asia (Gobi, Karakum, Lut, Taklimakan, and Thar deserts) during the growing season (April October) in the years 1982 2008 were investigated by analyzing the normalized difference vegetation index (NDVI), precipitation, and temperature. In the desert boundary regions, the domain mean NDVI values increased by 7.2% per decade in 1982 1998 but decreased by 6.8% per decade thereafter. Accordingly, the bare soil areas (or nonvegetated areas) of the inside of the desert boundaries contracted by 9.8% per decade in the 1990s and expanded by 8.7% per decade in the 2000s. It is noted that the five deserts experience nearly simultaneous NDVI changes although they cover a very diverse area of Asia. In contrast, changes in temperature and precipitation in the deserts show rather diverse results. In desert boundaries located along 40 N (Gobi, Taklimakan, and Karakum), the decadal changes in vegetation greenness were mainly related to regional climate during the entire analysis period. Precipitation increased in the 1990s, providing favorable conditions for vegetation growth (i.e., greening), but precipitation reduced (19 mm per decade) and warming intensified (0.7 C per decade) in the 2000s, causing less moisture to be available for vegetation growth (i.e., browning). In desert boundaries below 40 N (Lut and Thar), although an increase in precipitation (8 mm per decade) led to greening in the 1990s, local changes in precipitation and temperature did not necessarily cause browning in the 2000s. Observed multidecadal changes in vegetation greenness in the present study suggest that under significant global and/or regional warming, changes in moisture availability for vegetation growth in desert boundaries are an important factor when understanding decadal changes in areas vulnerable to desertification over Asia.

  19. Seasonal and interannual effects of hypoxia on fish habitat quality in central Lake Erie

    Science.gov (United States)

    Arend, Kristin K.; Beletsky, Dmitry; DePinto, Joseph; Ludsin, Stuart A.; Roberts, James J.; Rucinski, Daniel K.; Scavia, Donald; Schwab, David J.; Höök, Tomas O.

    2011-01-01

    1. Hypoxia occurs seasonally in many stratified coastal marine and freshwater ecosystems when bottom dissolved oxygen (DO) concentrations are depleted below 2–3 mg O2 L-1. 2. We evaluated the effects of hypoxia on fish habitat quality in the central basin of Lake Erie from 1987 to 2005, using bioenergetic growth rate potential (GRP) as a proxy for habitat quality. We compared the effect of hypoxia on habitat quality of (i) rainbow smelt, Osmerus mordax mordax Mitchill (young-of-year, YOY, and adult), a cold-water planktivore, (ii) emerald shiner, Notropis atherinoides Rafinesque (adult), a warm-water planktivore, (iii) yellow perch, Perca flavescens Mitchill (YOY and adult), a cool-water benthopelagic omnivore and (iv) round goby Neogobius melanostomus Pallas (adult) a eurythermal benthivore. Annual thermal and DO profiles were generated from 1D thermal and DO hydrodynamics models developed for Lake Erie’s central basin. 3. Hypoxia occurred annually, typically from mid-July to mid-October, which spatially and temporally overlaps with otherwise high benthic habitat quality. Hypoxia reduced the habitat quality across fish species and life stages, but the magnitude of the reduction varied both among and within species because of the differences in tolerance to low DO levels and warm-water temperatures. 4. Across years, trends in habitat quality mirrored trends in phosphorus concentration and water column oxygen demand in central Lake Erie. The per cent reduction in habitat quality owing to hypoxia was greatest for adult rainbow smelt and round goby (mean: -35%), followed by adult emerald shiner (mean: -12%), YOY rainbow smelt (mean: -10%) and YOY and adult yellow perch (mean: -8.5%). 5. Our results highlight the importance of differential spatiotemporally interactive effects of DO and temperature on relative fish habitat quality and quantity. These effects have the potential to influence the performance of individual fish species as well as population dynamics

  20. Browning in desert boundaries in Asia in recent decades

    Science.gov (United States)

    Jeong, Su-Jong; Ho, Chang-Hoi; Brown, Molly E.; Kug, Jong-Seong; Piao, Shilong

    2011-01-01

    In this study, the changes in desert boundaries in Asia (Gobi, Karakum, Lut, Taklimakan, and Thar deserts) during the growing season (April-October) in the years 1982-2008 were investigated by analyzing the normalized difference vegetation index (NDVI), precipitation, and temperature. In the desert boundary regions, the domain mean NDVI values increased by 7.2% per decade in 1982-1998 but decreased by 6.8% per decade thereafter. Accordingly, the bare soil areas (or nonvegetated areas) of the inside of the desert boundaries contracted by 9.8% per decade in the 1990s and expanded by 8.7% per decade in the 2000s. It is noted that the five deserts experience nearly simultaneous NDVI changes although they cover a very diverse area of Asia. In contrast, changes in temperature and precipitation in the deserts show rather diverse results. In desert boundaries located along 40°N (Gobi, Taklimakan, and Karakum), the decadal changes in vegetation greenness were mainly related to regional climate during the entire analysis period. Precipitation increased in the 1990s, providing favorable conditions for vegetation growth (i.e., greening), but precipitation reduced (19 mm per decade) and warming intensified (0.7°C per decade) in the 2000s, causing less moisture to be available for vegetation growth (i.e., browning). In desert boundaries below 40°N (Lut and Thar), although an increase in precipitation (8 mm per decade) led to greening in the 1990s, local changes in precipitation and temperature did not necessarily cause browning in the 2000s. Observed multidecadal changes in vegetation greenness in the present study suggest that under significant global and/or regional warming, changes in moisture availability for vegetation growth in desert boundaries are an important factor when understanding decadal changes in areas vulnerable to desertification over Asia.

  1. Effects of season, sex and body size on the feeding ecology of turtle-headed sea snakes ( Emydocephalus annulatus) on IndoPacific inshore coral reefs

    Science.gov (United States)

    Goiran, C.; Dubey, S.; Shine, R.

    2013-06-01

    In terrestrial snakes, many cases of intraspecific shifts in dietary habits as a function of predator sex and body size are driven by gape limitation and hence are most common in species that feed on relatively large prey and exhibit a wide body-size range. Our data on sea snakes reveal an alternative mechanism for intraspecific niche partitioning, based on sex-specific seasonal anorexia induced by reproductive activities. Turtle-headed sea snakes ( Emydocephalus annulatus) on coral reefs in the New Caledonian Lagoon feed entirely on the eggs of demersal-spawning fishes. DNA sequence data (cytochrome b gene) on eggs that we palpated from stomachs of 37 snakes showed that despite this ontogenetic stage specialization, the prey comes from a taxonomically diverse array of species including damselfish (41 % of samples, at least 5 species), blennies (41 %, 4 species) and gobies (19 %, 5 species). The composition of snake diets shifted seasonally (with damselfish dominating in winter but not summer), presumably reflecting seasonality of fish reproduction. That seasonal shift affects male and female snakes differently, because reproduction is incompatible with foraging. Adult female sea snakes ceased feeding when they became heavily distended with developing embryos in late summer, and males ceased feeding while they were mate searching in winter. The sex divergence in foraging habits may be amplified by sexual size dimorphism; females grow larger than males, and larger snakes (of both sexes) feed more on damselfish (which often lay their eggs in exposed sites) than on blennies and gobies (whose eggs are hidden within narrow crevices). Specific features of reproductive biology of coral reef fish (seasonality and nest type) have generated intraspecific niche partitioning in these sea snakes, by mechanisms different from those that apply to terrestrial snakes.

  2. Corrections and clarifications to the descriptions of Biendongella and Sovvityazius (Perciformes: Gobiidae).

    Science.gov (United States)

    Murdy, Edward O

    2017-06-09

    Prokofiev (2015a) described two new genera and species of Amblyopinae and reported new amblyopine records from waters off Indonesia, the Philippines, and Vietnam. In reviewing Prokofiev's figures and reading the descriptions of his new genera, Biendongella Prokofiev, 2015 and Sovvityazius Prokofiev, 2015, it appeared likely that these new taxa were based on species also under examination by Koichi Shibukawa and me. However, some differences existed between our specimens and those described by Prokofiev in the pterygiophore formula (DF), the presence/absence of hypural 5, and the number of epurals. The data and information on these characters were not abundantly clear from the text and clarification was needed. For example, on page 786 of Prokofiev (2015a) the following diagnostic feature of Biendongella was provided, "DF 3 1221, vacant interneural gap between spined and soft parts of D present; two first pterygiophores of soft part of D each located in its interneural gap…". Similar wording exists for Sovvityazius on page 789, "DF 3 1221, vacant gap between spined and soft parts of D present; two first pterygiophores of soft part of D each in its interneural space…". As for hypural 5 and the number of epurals, the same statement is given for both Biendongella and Sovvityazius on pages 786 and 789, respectively, "Hypural 5 and epural 2 absent." These character states struck me as remarkable as they are atypical for amblyopines. With respect to the DF character above, amblyopine gobies with a pterygiophore formula of 3-1221 have no interneural gap and the interneural space immediately posterior to the pterygiophore of the ultimate spinous ray contains two pterygiophores (Murdy 2011). As for the latter characters, hypural 5 and two epurals are present in amblyopine gobies (Shibukawa and Murdy 2012). In a detailed email to Prokofiev, I asked for clarification of these discrepancies and whether Biendongella and Sovvityazius have the amblyopine synapomorphy of the

  3. Evaluating dispersal potential of an invasive fish by the use of aerobic scope and osmoregulation capacity.

    Directory of Open Access Journals (Sweden)

    Jane W Behrens

    Full Text Available Non-indigenous species (NIS can impact marine biodiversity and ecosystem structure and function. Once introduced into a new region, secondary dispersal is limited by the physiology of the organism in relation to the ambient environment and by complex interactions between a suite of ecological factors such as presence of predators, competitors, and parasites. Early prediction of dispersal potential and future 'area of impact' is challenging, but also a great asset in taking appropriate management actions. Aerobic scope (AS in fish has been linked to various fitness-related parameters, and may be valuable in determining dispersal potential of aquatic invasive species in novel environments. Round goby, Neogobius melanostomus, one of the most wide-ranging invasive fish species in Europe and North America, currently thrives in brackish and fresh water, but its ability to survive in high salinity waters is unknown to date. We show that AS in round goby is reduced by 30% and blood plasma osmolality increased (indicating reduced capacity for osmoregulation at salinities approaching oceanic conditions, following slow ramping (5 PSU per week and subsequent long-term acclimation to salinities ranging between 0 and 30 PSU (8 days at final treatment salinities before blood plasma osmolality measurements, 12-20 additional days before respirometry. Survival was also reduced at the highest salinities yet a significant proportion (61% of the fish survived at 30 PSU. Reduced physiological performance at the highest salinities may affect growth and competitive ability under oceanic conditions, but to what extent reduced AS and osmoregulatory capacity will slow the current 30 km year-1 rate of advance of the species through the steep salinity gradient from the brackish Baltic Sea and into the oceanic North Sea remains speculative. An unintended natural experiment is in progress to test whether the rate of advance slows down. At the current rate of advance the

  4. Fluctuating asymmetry in evaluating the developmental instability of Glossogobius giuris (Hamilton, 1822 from Lake Mainit, Surigao del Norte, Philippines

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    C.C.D.Joseph

    2016-06-01

    Full Text Available This study was conducted to assess the status of Lake Mainit by using fluctuating asymmetry in the populations of Glossogobius giuris. A total of 200 G. giuris was collected with 100 per sex. All the samples were placed in a flat styrofoam for the pinning of its fins to make it wider and to clearly see the samples point of origin for the land-marking process. 10% Formalin was applied in all the fins of the fish samples to make it hardened using a small brush. Twenty (20 landmarks were used to analyze the body shape of the fish. Several studies proved that FA can be used to directly assess water quality and the overall status of the ecosystem. Using thin-plate spline (TPS series, landmark analyses were obtained and subjected to Symmetry and Asymmetry in Geometric Data (SAGE software. Results in Procrustes ANOVA showed that individual symmetry showed a highly significant difference (P = 0.00 as well as Sides (Directional Asymmetry and Interaction (Fluctuating Asymmetry in the study area. All the samples showed FA in both sexes. The results of Principal Component Scores displayed a higher percentage in female (69.2797% than male (63.9214% from Lake Mainit. Variations are almost found in all the body part of the goby in female and male gobies except for anterior insertion of second dorsal fin and superior margin of the preoperculum. Females have a higher fluctuating asymmetry than in males. Females spawn and males protect the eggs from any predators. In this case, females are more susceptible to stress because they have to forage in order to compensate the energy used up during spawning. Males are less susceptible because they usually stay on the nesting ground, and don't have to cover far distances in finding food. This study validates the use of FA in determining the status of the fishes caught connecting to what the status of the environment is based on the result.

  5. The Holocene evolution of Juyan lake, Inner Mongolia, China

    Science.gov (United States)

    Hartmann, K.; Wuennemann, B.; Roeper, H.-P.; Herzschuh, U.

    2003-04-01

    The Juyan Paleolake in Inner Mongolia, China, is the eastern part of three former terminal lakes located at the outer edges of the Hei River fan which formed a large inland delta between the Qilian Mts (Tibetan Plateau) and the Gobi Altay Mts. Detailed geomorphological investigations by remote sensing techniques show that the paleolake is surrounded by several well preserved paleoshorelines indicating lake level fluctuations during the Holocene. At present young dunes migrate into the dry lake basin. In contrast to the neighbouring paleolakes Gaxun Nur and Sogo Nur the lake level fluctuations of the Juyan paleolake were mainly controlled by local rainfall and water supply from the Gobi Altay Mts. An 8.25 m long sediment core from the northwestern part of Juyan lake provides detailed information about changes in sedimentation processes, e.g. variations in salt contents and hydrology between 10 cal ka and 240 cal AD. Grain size variations, geochemical composition and XRD analyses indicate four distinct lake phases of mainly shallow and saline water bodies at 10-7.6 cal ka, 6.6-6.2 cal ka, 5.6-3.2 cal ka and 3-2.5 cal ka, interrupted by desiccation periods with enhanced aeolian deposition. As they are in-phase with lake level changes in western China (e.g. Bosten lake, Sumxi Co, Bangong Co) climate-induced variations in the precipitation/evaporation ratio may be inferred. The youngest detectable period of short term lake phases between 400 BC and 250 AD matches the historical settlements along the shorelines of Juyan lake during Han-Dynasty.

  6. Meiofauna as food source for small-sized demersal fish in the southern North Sea

    Science.gov (United States)

    Schückel, Sabine; Sell, Anne F.; Kihara, Terue C.; Koeppen, Annemarie; Kröncke, Ingrid; Reiss, Henning

    2013-06-01

    Meiofauna play an essential role in the diet of small and juvenile fish. However, it is less well documented which meiofaunal prey groups in the sediment are eaten by fish. Trophic relationships between five demersal fish species (solenette, goby, scaldfish, dab <20 cm and plaice <20 cm) and meiofaunal prey were investigated by means of comparing sediment samples and fish stomach contents collected seasonally between January 2009 and January 2010 in the German Bight. In all seasons, meiofauna in the sediment was numerically dominated by nematodes, whereas harpacticoids dominated in terms of occurrence and biomass. Between autumn and spring, the harpacticoid community was characterized by Pseudobradya minor and Halectinosoma canaliculatum, and in summer by Longipedia coronata. Meiofaunal prey dominated the diets of solenette and gobies in all seasons, occurred only seasonally in the diet of scaldfish and dab, and was completely absent in the diet of plaice. For all fish species (excluding plaice) and in each season, harpacticoids were the most important meiofauna prey group in terms of occurrence, abundance and biomass. High values of Ivlev's index of selectivity for Pseudobradya spp. in winter and Longipedia spp. in summer provided evidence that predation on harpacticoids was species-selective, even though both harpacticoids co-occurred in high densities in the sediments. Most surficial feeding strategies of the studied fish species and emergent behaviours of Pseudobradya spp. and Longipedia spp. might have caused this prey selection. With increasing fish sizes, harpacticoid prey densities decreased in the fish stomachs, indicating a diet change towards larger benthic prey during the ontogeny of all fish species investigated.

  7. PENGARUH SISTEM PERGANTIAN AIR YANG BERBEDA PADA PEMELIHARAAN BENIH IKAN BETUTU (Oxyeleotris marmorata Blkr.

    Directory of Open Access Journals (Sweden)

    Imam Taufik

    2016-12-01

    Full Text Available Penelitian bertujuan untuk mengetahui sistem pergantian air yang paling baik pada pemeliharaan benih ikan betutu. Wadah penelitian: 12 unit bak kayu berlapis plastik (1,9m x 0,8m x 0,5m diisi air 500 L, ditempatkan dalam ruang terlindung dan dilengkapi dengan aerasi. Hewan uji: benih ikan betutu ukuran bobot 0,96±0,08 g/ekor, padat tebar 1 ekor/5 liter air, diberi pakan alami secara berlebih dengan waktu pemeliharaan selama 12 minggu. Perlakuan berupa perbedaan sistem pergantian air: (a resirkulasi, (b semi-statis, dan (c continous flow. Parameter yang diukur: sintasan, pertumbuhan, dan produktivitas benih ikan betutu serta sifat fisika-kimia air pemeliharaan. Hasil penelitian menunjukkan bahwa pergantian air dengan sistem resirkulasi memberikan sintasan yang paling baik terhadap benih ikan betutu (33,0% dibanding continous flow (28,3% dan berbeda nyata (P0,05 dengan nilai secara berturut-turut sebesar: 1,41%; 1,31%; dan 1,50%. The aim of this experiment is to obtain the information on survival rate and growth of sand goby fries. The experiment was conducted at research station CibalagungBogor. Twelve container of 1.9m x 0.8m x 0.5m were used in this experiment, each container was stocked with 1 fish/5L of sand goby fry with 0.96±0.08 gram weight. Three different water exchange were aplied i.e (a recirculation, (b semi static, and (c continous flow. Each treatment was done in three replicates. The result showed that the recirculation gave the best result on survival rate (33.0% compared with continous flow (28.3% and significantly different from semi static (21.3%.

  8. Predator diversity effects in an exotic freshwater food web.

    Directory of Open Access Journals (Sweden)

    Rahmat Naddafi

    Full Text Available Cascading trophic interactions are often defined as the indirect effects of a predator on primary producers through the effect of the predator on herbivores. These effects can be both direct through removal of herbivores [density-mediated indirect interactions (DMIIs] or indirect through changes in the behavior of the herbivores [trait-mediated indirect interactions (TMIIs]. How the relative importance of these two indirect interactions varies with predator diversity remains poorly understood. We tested the effect of predator diversity on both TMIIs and DMIIs on phytoplankton using two competitive invasive dreissenid mussel species (zebra mussel and quagga mussel as the herbivores and combinations of one, two or all three species of the predators pumpkinseed sunfish, round goby, and rusty crayfish. Predators had either direct access to mussels and induced both TMII and DMII, or no direct access and induced only TMII through the presence of risk cues. In both sets of treatments, the predators induced a trophic cascade which resulted in more phytoplankton remaining with predators present than with only mussels present. The trophic cascade was weaker in three-predator and two-predator treatments than in one-predator treatments when predators had direct access to dreissenids (DMIIs and TMIIs. Crayfish had higher cascading effects on phytoplankton than both pumpkinseed and round goby. Increased predator diversity decreased the strength of DMIIs but had no effect on the strength of TMIIs. The strength of TMIIs was higher with zebra than quagga mussels. Our study suggests that inter-specific interference among predators in multi-species treatments weakens the consumptive cascading effects of predation on lower trophic levels whereas the importance of predator diversity on trait mediated effects depends on predator identity.

  9. Gyrodactylus salinae n. sp. (Platyhelminthes: Monogenea infecting the south European toothcarp Aphanius fasciatus (Valenciennes (Teleostei, Cyprinodontidae from a hypersaline environment in Italy

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    Huyse Tine

    2011-06-01

    Full Text Available Abstract Background Historically, non-native species of Gambusia (Poeciliidae have been used to control larval stages of the Asian tiger mosquito, Stegomyia albopicta Reinert, Harbach et Kitching, 2004 throughout Italy. The potential utility of indigenous populations of Aphanius fasciatus (Valenciennes (Teleostei: Cyprinodontidae as an appropriate alternative biological control is currently being explored. A sub-sample of ten fish collected from Cervia Saline, Italy (salinity 65 ppt; 30°C to assess their reproductive capability in captivity, harboured a moderate infection of Gyrodactylus von Nordmann, 1832 (Platyhelminthes, Monogenea. A subsequent morphological and molecular study identified this as being a new species. Results Gyrodactylus salinae n. sp. is described from the skin, fins and gills of A. fasciatus. Light and scanning electron microscopical (SEM examination of the opisthaptoral armature and their comparison with all other recorded species suggested morphological similarities to Gyrodactylus rugiensoides Huyse et Volckaert, 2002 from Pomatoschistus minutus (Pallas. Features of the ventral bar, however, permit its discrimination from G. rugiensoides. Sequencing of the nuclear ribosomal DNA internal transcribed spacers 1 and 2 and the 5.8S rRNA gene and a comparison with all species listed in GenBank confirmed they are unique and represent a new species (most similar to Gyrodactylus anguillae Ergens, 1960, 8.3% pair-wise distance based on 5.8S+ITS2. This represents the first species of Gyrodactylus to be described from Aphanius and, to date, has the longest ITS1 (774 bp sequenced from any Gyrodactylus. Additional sampling of Cervia Saline throughout the year, found G. salinae n. sp. to persist in conditions ranging from 35 ppt and 5°C in December to 65 ppt and 30°C in July, while in captivity a low level of infection was present, even in freshwater conditions (0 ppt. Conclusions The ability of G. salinae n. sp. to tolerate a wide

  10. Atlas de distribución y estado de conservación de los Anfibios de la Comunidad de Madrid

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    Martínez-Solano, I.

    2006-05-01

    Full Text Available Successful management and conservation planning depend upon the availability, integration and updating of information provided by different disciplines. This paper compiles relevant information for the conservation of amphibians in Comunidad de Madrid (Spain. We obtained chorological information from 1384 sampling localities throughout the region of Madrid, and reviewed relevant scientific literature for the management of amphibian populations in this area. We found at least one amphibian species in 70,3% of sampled localities. Results are illustrated in distribution maps of all 18 species found: Salamandra salamandra, Pleurodeles waltl, Mesotriton alpestris, Lissotriton boscai, Triturus marmoratus, Triturus pygmaeus, Alytes obstetricans, Alytes cisternasii, Discoglossus galganoi, Discoglossus jeanneae, Pelobates cultripes, Pelodytes punctatus, Hyla arborea, Hyla meridionalis, Bufo bufo, Bufo calamita, Rana iberica and Rana perezi. Distribution maps are presented in five-kilometer side UTM grids cells. We compare and integrate our results with previous studies and outline groups of populations representing independent management units, for which we propose risk categories according to the criteria established by the International Union for the Conservation of Nature (IUCN at the regional level. Finally, we point out the main threats for the survival of amphibian populations and discuss possible actions to improve their conservation status.

    La planificación de estrategias de gestión y conservación eficaces depende de la disponibilidad, integración y actualización de información procedente de diversas disciplinas. En este trabajo se recopila información relevante para la conservación de los anfibios de la Comunidad de Madrid. Hemos obtenido información corológica de un total de 1384 puntos de muestreo repartidos por toda la geografía madrileña y revisado la literatura científica de interés para la gestión de las

  11. Disturbance of a rare seabird by ship-based tourism in a marine protected area

    Science.gov (United States)

    Marcella, Timothy K.; Gende, Scott M.; Roby, Daniel D.; Allignol, Arthur

    2017-01-01

    Managers of marine protected areas (MPAs) must often seek ways to allow for visitation while minimizing impacts to the resources they are intended to protect. Using shipboard observers, we quantified the “zone of disturbance” for Kittlitz’s and marbled murrelets (Brachyramphus brevirostris and B. marmoratus) exposed to large cruise ships traveling through Glacier Bay National Park, one of the largest MPAs in North America. In the upper reaches of Glacier Bay, where Kittlitz’s murrelets predominated, binary logistic regression models predicted that 61% of all murrelets within 850 m perpendicular distance of a cruise ship were disturbed (defined as flushing or diving), whereas in the lower reaches, where marbled murrelets predominated, this percentage increased to 72%. Using survival analysis, murrelets in both reaches were found to react at greater distances when ships approached indirectly, presumably because of the ship’s larger profile, suggesting murrelets responded to visual rather than audio cues. No management-relevant covariates (e.g., ship velocity, route distance from shore) were found to be important predictors of disturbance, as distance from ship to murrelet accounted for > 90% of the explained variation in murrelet response. Utilizing previously published murrelet density estimates from Glacier Bay, and applying an average empirical disturbance probability (68%) out to 850 m from a cruise ship’s typical route, we estimated that a minimum of 9.8–19.6% of all murrelets in Glacier Bay are disturbed per ship entry. Whether these disturbance levels are inconsistent with Park management objectives, which include conserving wildlife as well as providing opportunities for visitation, depends in large part on whether disturbance events caused by cruise ships have impacts on murrelet fitness, which remains uncertain.

  12. Invasive amphibians in southern Africa: A review of invasion pathways

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    John Measey

    2017-03-01

    Full Text Available Background: Globally, invasive amphibians are known for their environmental and social impacts that range from poisoning of local fauna and human populations to direct predation on other amphibians. Although several countries on most continents have had multiple introductions of many species, southern Africa appears to have escaped allochthonous introductions. Instead, it has a small number of domestic exotic species that have rapidly expanded their ranges and established invasive populations within South Africa. Objectives & methods: We used the literature to provide a historical overview of dispersal by some of the world’s major invasive amphibians, give examples of species that are commonly moved as stowaways and discuss historical and current amphibian trade in the region. In addition, we give an overview of new South African legislation and how this is applied to amphibian invasions, as well as providing updates on the introduced populations of three domestic exotics: Hyperolius marmoratus, Sclerophrys gutturalis and Xenopus laevis. Results: We show that frogs are mainly moved around southern Africa through ‘jump’ dispersal, although there are a number of records of ‘cultivation’, ‘leading-edge’ and ‘extreme long-distance’ dispersal types. Important pathways include trade in fruit and vegetables, horticultural products and shipping containers. Conclusion: We suggest that southern Africa is becoming more vulnerable to amphibian invasions because of an increase in trade, agricultural and domestic impoundments as well as global climate change. Increasing propagule pressure suggests that preventing new introductions will become a key challenge for the future. Currently, trade in amphibians in the region is practically non-existent, suggesting potential for best practice to prevent importation of species with high invasion potential and to stop the spread of disease.

  13. New Mediterranean Biodiversity Records (April 2015

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    Α. ΖΕΝΕΤΟΣ

    2015-01-01

    Full Text Available The Collective Article ‘New Mediterranean Biodiversity Records’ of the Mediterranean Marine Science journal offers the means to publish biodiversity records in the Mediterranean Sea. The current article is divided in two parts, for records of native and alien species respectively. The new records of native fish species include: the slender sunfish Ranzania laevis and the scalloped ribbonfish Zu cristatus in Calabria; the Azores rockling Gaidropsarus granti in Calabria and Sicily; the agujon needlefish Tylosurus acus imperialis in the Northern Aegean; and the amphibious behaviour of Gouania willdenowi in Southern Turkey. As regards molluscs, the interesting findings include Ischnochiton usticensis in Calabria and Thordisa filix in the bay of Piran (Slovenia. The stomatopod Parasquilla ferussaci was collected from Lesvos island (Greece; the isopod Anilocra frontalis was observed parasitizing the alien Pteragogus trispilus in the Rhodes area. The asteroid Tethyaster subinermis and the butterfly ray Gymnura altavela were reported from several localities in the Greek Ionian and Aegean Seas. The new records of alien species include: the antenna codlet Bregmaceros atlanticus in Saronikos Gulf; three  new fish records and two decapods from Egypt; the establishment of the two spot cardinal fish Cheilodipterus novemstriatus and the first record of the Indo-Pacific marble shrimp Saron marmoratus in semi-dark caves along the Lebanese coastline; the finding of Lagocephalus sceleratus, Sargocentron rubrum, Fistularia commersonii and Stephanolepis diaspros around Lipsi island (Aegean Sea, Greece; the decapod Penaeus hathor in Aegean waters; the decapod Penaeus aztecus and the nudibranch Melibe viridis in the Dodecanese islands; the finding of Pinctada imbricata radiata in the Mar Grande of Taranto (Ionian Sea, Italy and the Maliakos Gulf (Greece.

  14. Status and trend of the Kittlitz's Murrelet Brachyramphus brevirostris in Glacier Bay, Alaska

    Science.gov (United States)

    Piatt, John F.; Arimitsu, Mayumi L.; Drew, Gary S.; Madison, Erica N.; Bodkin, James L.; Romano, Marc D.

    2011-01-01

    We conducted standardized surveys for marine birds in Glacier Bay in seven years between 1991 and 2008. From our most recent survey, a combination of line- and strip-transect methods completed in 2008, we estimated that 4981 (95% CI 1293–8670) Kittlitz’s Murrelets Brachyramphus brevirostris resided in Glacier Bay during the month of June, together with 12 195 (5607–18 783) Marbled Murrelets B. marmoratus. When counts were prorated to assign unidentified Brachyramphus murrelets to species, population estimates increased to 5641 Kittlitz’s Murrelets and 13 810 Marbled Murrelets. Our surveys of bird numbers in Glacier Bay between 1991 and 2008 revealed that Kittlitz’s Murrelet declined by ≥85% during this period. Trend analysis suggested a rate of decline between -10.7% and -14.4% per year. No direct human impacts (e.g., bycatch, oil pollution, vessel disturbance) in our study area could fully account for a decline of this magnitude. Widespread declines of Brachyramphus murrelets and Harbor Seals Phoca vitulina in the Gulf of Alaska during the 1980s-1990s suggest large-scale influences on these marine predators, perhaps related to climate-mediated cycles in food supply. Other natural factors that may impact Glacier Bay populations include predation by avian and terrestrial predators, widespread glacial retreat and its effect on nesting and foraging habitats, and competition for food with marine predators whose abundance in Glacier Bay has increased markedly in recent years (Humpback Whales Megaptera novaeangliae and Steller Sea Lions Eumetopias jubatus).

  15. Disturbance of a rare seabird by ship-based tourism in a marine protected area.

    Science.gov (United States)

    Marcella, Timothy K; Gende, Scott M; Roby, Daniel D; Allignol, Arthur

    2017-01-01

    Managers of marine protected areas (MPAs) must often seek ways to allow for visitation while minimizing impacts to the resources they are intended to protect. Using shipboard observers, we quantified the "zone of disturbance" for Kittlitz's and marbled murrelets (Brachyramphus brevirostris and B. marmoratus) exposed to large cruise ships traveling through Glacier Bay National Park, one of the largest MPAs in North America. In the upper reaches of Glacier Bay, where Kittlitz's murrelets predominated, binary logistic regression models predicted that 61% of all murrelets within 850 m perpendicular distance of a cruise ship were disturbed (defined as flushing or diving), whereas in the lower reaches, where marbled murrelets predominated, this percentage increased to 72%. Using survival analysis, murrelets in both reaches were found to react at greater distances when ships approached indirectly, presumably because of the ship's larger profile, suggesting murrelets responded to visual rather than audio cues. No management-relevant covariates (e.g., ship velocity, route distance from shore) were found to be important predictors of disturbance, as distance from ship to murrelet accounted for > 90% of the explained variation in murrelet response. Utilizing previously published murrelet density estimates from Glacier Bay, and applying an average empirical disturbance probability (68%) out to 850 m from a cruise ship's typical route, we estimated that a minimum of 9.8-19.6% of all murrelets in Glacier Bay are disturbed per ship entry. Whether these disturbance levels are inconsistent with Park management objectives, which include conserving wildlife as well as providing opportunities for visitation, depends in large part on whether disturbance events caused by cruise ships have impacts on murrelet fitness, which remains uncertain.

  16. Disturbance of a rare seabird by ship-based tourism in a marine protected area.

    Directory of Open Access Journals (Sweden)

    Timothy K Marcella

    Full Text Available Managers of marine protected areas (MPAs must often seek ways to allow for visitation while minimizing impacts to the resources they are intended to protect. Using shipboard observers, we quantified the "zone of disturbance" for Kittlitz's and marbled murrelets (Brachyramphus brevirostris and B. marmoratus exposed to large cruise ships traveling through Glacier Bay National Park, one of the largest MPAs in North America. In the upper reaches of Glacier Bay, where Kittlitz's murrelets predominated, binary logistic regression models predicted that 61% of all murrelets within 850 m perpendicular distance of a cruise ship were disturbed (defined as flushing or diving, whereas in the lower reaches, where marbled murrelets predominated, this percentage increased to 72%. Using survival analysis, murrelets in both reaches were found to react at greater distances when ships approached indirectly, presumably because of the ship's larger profile, suggesting murrelets responded to visual rather than audio cues. No management-relevant covariates (e.g., ship velocity, route distance from shore were found to be important predictors of disturbance, as distance from ship to murrelet accounted for > 90% of the explained variation in murrelet response. Utilizing previously published murrelet density estimates from Glacier Bay, and applying an average empirical disturbance probability (68% out to 850 m from a cruise ship's typical route, we estimated that a minimum of 9.8-19.6% of all murrelets in Glacier Bay are disturbed per ship entry. Whether these disturbance levels are inconsistent with Park management objectives, which include conserving wildlife as well as providing opportunities for visitation, depends in large part on whether disturbance events caused by cruise ships have impacts on murrelet fitness, which remains uncertain.

  17. Constraints upon the response of fish and crayfish to environmental flow releases in a regulated headwater stream network.

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    Edwin T Chester

    Full Text Available In dry climate zones, headwater streams are often regulated for water extraction causing intermittency in perennial streams and prolonged drying in intermittent streams. Regulation thereby reduces aquatic habitat downstream of weirs that also form barriers to migration by stream fauna. Environmental flow releases may restore streamflow in rivers, but are rarely applied to headwaters. We sampled fish and crayfish in four regulated headwater streams before and after the release of summer-autumn environmental flows, and in four nearby unregulated streams, to determine whether their abundances increased in response to flow releases. Historical data of fish and crayfish occurrence spanning a 30 year period was compared with contemporary data (electrofishing surveys, Victoria Range, Australia; summer 2008 to summer 2010 to assess the longer-term effects of regulation and drought. Although fish were recorded in regulated streams before 1996, they were not recorded in the present study upstream or downstream of weirs despite recent flow releases. Crayfish (Geocharax sp. nov. 1 remained in the regulated streams throughout the study, but did not become more abundant in response to flow releases. In contrast, native fish (Gadopsis marmoratus, Galaxias oliros, Galaxias maculatus and crayfish remained present in unregulated streams, despite prolonged drought conditions during 2006-2010, and the assemblages of each of these streams remained essentially unchanged over the 30 year period. Flow release volumes may have been too small or have operated for an insufficient time to allow fish to recolonise regulated streams. Barriers to dispersal may also be preventing recolonisation. Indefinite continuation of annual flow releases, that prevent the unnatural cessation of flow caused by weirs, may eventually facilitate upstream movement of fish and crayfish in regulated channels; but other human-made dispersal barriers downstream need to be identified and

  18. Comparison of pigment cell ultrastructure and organisation in the dermis of marble trout and brown trout, and first description of erythrophore ultrastructure in salmonids

    Science.gov (United States)

    Djurdjevič, Ida; Kreft, Mateja Erdani; Sušnik Bajec, Simona

    2015-01-01

    Skin pigmentation in animals is an important trait with many functions. The present study focused on two closely related salmonid species, marble trout (Salmo marmoratus) and brown trout (S. trutta), which display an uncommon labyrinthine (marble-like) and spot skin pattern, respectively. To determine the role of chromatophore type in the different formation of skin pigment patterns in the two species, the distribution and ultrastructure of chromatophores was examined with light microscopy and transmission electron microscopy. The presence of three types of chromatophores in trout skin was confirmed: melanophores; xanthophores; and iridophores. In addition, using correlative microscopy, erythrophore ultrastructure in salmonids was described for the first time. Two types of erythrophores are distinguished, both located exclusively in the skin of brown trout: type 1 in black spot skin sections similar to xanthophores; and type 2 with a unique ultrastructure, located only in red spot skin sections. Morphologically, the difference between the light and dark pigmentation of trout skin depends primarily on the position and density of melanophores, in the dark region covering other chromatophores, and in the light region with the iridophores and xanthophores usually exposed. With larger amounts of melanophores, absence of xanthophores and presence of erythrophores type 1 and type L iridophores in the black spot compared with the light regions and the presence of erythrophores type 2 in the red spot, a higher level of pigment cell organisation in the skin of brown trout compared with that of marble trout was demonstrated. Even though the skin regions with chromatophores were well defined, not all the chromatophores were in direct contact, either homophilically or heterophilically, with each other. In addition to short-range interactions, an important role of the cellular environment and long-range interactions between chromatophores in promoting adult pigment pattern

  19. Prior contest experience exerts a long-term influence on subsequent winner and loser effects

    Science.gov (United States)

    2011-01-01

    Introduction Animals are capable of using information from recent experiences to modify subsequent behavioral responses. Animals' ability or propensity to modify their behavior in the light of new information has repeatedly been shown to correlate with, or be influenced by, either their intrinsic competitive ability or their dominance experience - an influence which can be long-lasting. Using a mangrove killifish, Kryptolebias marmoratus, as the study organism, we investigated whether and if so how the effect of a winning or a losing experience one day prior to a dyadic contest was modulated by both competitive ability measured two months previously and a winning or losing experience forced on the contestants one month previously. Results Winning/losing experience forced on the fish one month previously affected how they utilized information from their winning/losing experience one day before Test Day: Individuals that were randomly assigned a losing experience one month previously were more susceptible to the influence of their 1-day winning/losing experience than those assigned a winning experience. Competitive ability measured two months previously, winning/losing experience from one month previously and the winning/losing experience received one day previously all significantly influenced the fish's contest behaviors on Test Day, although only 2-month competitive ability significantly influenced escalation duration, indicating that it was still a good index for the fish's competitive ability two months later. Conclusions These results suggest that the value to the fish of information from a recent win or loss depends on the outcome of their past contests and show that contest experience has a long-term effect on contest behavior. PMID:22051441

  20. MR findings of cerebral palsy: comparison between preterm patients and fullterm patients

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, Yoon Joon; Kim, Dong Ik; Yoon, Pyeong Ho; Jeon, Pyoung; Ryu, Young Hoon; Hwang, Geum Ju; Kim, Eun Kyung [Yonsei Univ. College of Medicine, Seoul (Korea, Republic of); Lee, Byung Hee [Pundang Cha General Hospital, Sungnam (Korea, Republic of)

    1997-09-01

    To observe the MR findings of cerebral palsy by evaluating cerebral damage resulting from hypoxic ischemic injury and other variable causes and to compare the findings between preterm and full-term patients. We reviewed the MR findings of 102 cerebral palsy patients (71 full-term and 31 preterm). These were analysed with regard to deep and peripheral white matter, gray matter, basal ganglia, the thalamus, brainstem, cerebellum, corpus callosum and ventricles, according to the pattern of injury such as hypoxic ischemic injury, migration anomaly and early intrauterine injury, the findings of full-term and preterm patients were then compared. MR findings of preterm patients(n=3D31) were as follows;hypoxic ischemic injury(n=3D26),normal(n=3D2), and migration anomaly(n=3D3), while those of full-term patients(n=3D71) were hypoxic ischemic injury(n=3D41), normal(n=3D24), migration anomaly(n=3D4), early uterine injury(n=3D2), and perirolandic ischemic injury(n=3D6);in 5 patients, this latter condition was combined with status marmoratus. Periventricular leukomalacia was the most common finding in both preterm patients and full-term patients;selective neuronal necrosis, parasagittal injury and perirolandic injury were observed only in full-term patients. On MRI, variable findings of cerebral palsy were clearly observed;periventricular leukomalacia was the most common finding in both preterm and full-term patients.=20.

  1. Estimation of Coast-Wide Population Trends of Marbled Murrelets in Canada Using a Bayesian Hierarchical Model.

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    Douglas F Bertram

    Full Text Available Species at risk with secretive breeding behaviours, low densities, and wide geographic range pose a significant challenge to conservation actions because population trends are difficult to detect. Such is the case with the Marbled Murrelet (Brachyramphus marmoratus, a seabird listed as 'Threatened' by the Species at Risk Act in Canada largely due to the loss of its old growth forest nesting habitat. We report the first estimates of population trend of Marbled Murrelets in Canada derived from a monitoring program that uses marine radar to detect birds as they enter forest watersheds during 923 dawn surveys at 58 radar monitoring stations within the six Marbled Murrelet Conservation Regions on coastal British Columbia, Canada, 1996-2013. Temporal trends in radar counts were analyzed with a hierarchical Bayesian multivariate modeling approach that controlled for variation in tilt of the radar unit and day of year, included year-specific deviations from the overall trend ('year effects', and allowed for trends to be estimated at three spatial scales. A negative overall trend of -1.6%/yr (95% credibility interval: -3.2%, 0.01% indicated moderate evidence for a coast-wide decline, although trends varied strongly among the six conservation regions. Negative annual trends were detected in East Vancouver Island (-9%/yr and South Mainland Coast (-3%/yr Conservation Regions. Over a quarter of the year effects were significantly different from zero, and the estimated standard deviation in common-shared year effects between sites within each region was about 50% per year. This large common-shared interannual variation in counts may have been caused by regional movements of birds related to changes in marine conditions that affect the availability of prey.

  2. Systematic review and cladistic analysis of the Hernandariinae (Opiliones: Gonyleptidae

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    Marcio Bernardino DaSilva

    2010-08-01

    Full Text Available The harvestmen subfamily Hernandariinae is reviewed and a new classification is proposed based on cladistic analysis using 67 morphological characters. The subfamily is composed of six genera and 23 species and occurs in south-southeastern Brazil, Paraguay, and northeastern Argentina. Fourteen new combinations are proposed: Hernandaria armatifrons (Roewer, 1917; H. una (Mello-Leitão, 1927; Acrogonyleptes granulatus (H. Soares, 1966; A. pectinifemur (Soares & Soares, 1947; Acanthogonyleptes alticola (Mello-Leitão, 1922; A. editus (Roewer, 1943; A. fallax (Mello-Leitão, 1932; A. fulvigranulatus (Mello-Leitão, 1922; A. marmoratus (Mello-Leitão, 1940; A. pictus (Piza, 1942; A. singularis (Mello-Leitão, 1935; A. soaresi (Mello-Leitão, 1944; A. variolosus (Mello-Leitão, 1944. Seven synonymies are proposed: Proweyhia Mello-Leitão, 1927 and Metaxundarava Mello-Leitão, 1927 = Hernandaria Sørensen, 1884; Apembolephaenus calcaratus Soares & Soares, 1945 = H. armatifrons (Roewer, 1917; Sphaerobunus Rower, 1917 and Paraproweyhia Soares & Soares, 1947 = Acrogonyleptes Roewer, 1917; Paraproweyhia curitibae Soares & Soares, 1947 = Acrogonyleptes exochus (Mello-Leitão, 1931; and Melloleitaniana curitibae B. Soares, 1943 = Acrogonyleptes spinifrons Roewer, 1917. Three species are revalidated: Acrogonyleptes granulatus (H. Soares, 1966, A. pectinifemur (Soares & Soares, 1947, and A. spinifrons Roewer, 1917. Seven new species are described: Hernandaria sundermannorum sp. nov. (São Paulo State, Brazil, Hernandaria anitagaribaldiae sp. nov. (Santa Catarina State, Brazil, Hernandaria zumbii sp. nov. (Santa Catarina State, Brazil, Hernandaria chicomendesi sp. nov. (Santa Catarina State, Brazil, Acrogonyleptes cheguevarai sp. nov. (Rio Grande do Sul State, Brazil, Pseudotrogulus pagu sp. nov. (São Paulo State, Brazil, Pseudotrogulus trotskyi sp. nov. (Paraná State, Brazil.

  3. Fauna parasitária dos híbridos siluriformes cachapinta e jundiara nos primeiros estágios de desenvolvimento

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    Arlene Sobrinho Ventura

    2013-08-01

    Full Text Available O objetivo deste trabalho foi avaliar a fauna parasitária dos peixes híbridos cachapinta (Pseudoplatystoma corruscans macho x P. reticulatum fêmea e jundiara (Leiarius marmoratus macho x P. reticulatum fêmea no período de larvicultura. Um total de 315 animais, 126 híbridos jundiara e 189 híbridos cachapinta, foram examinados de acordo com o estágio de desenvolvimento: larvas, pós-larvas e alevinos. Larvas e pós-larvas foram prensadas entre lâmina e lamínula e observadas sob microscopia óptica. Os alevinos foram observados externamente em estereomicroscópio e necropsiados para avaliação interna dos órgãos. Foram aferidos os parâmetros de qualidade de água em todas as fases de cultivo. O exame parasitológico revelou a presença dos protozoários Epistylis sp. e Trichodina sp., no tegumento e nas brânquias, Ichthyophthirius multifiliis no tegumento, dos helmintos Monogenea nas brânquias, e das metacercárias de digenéticos em brânquias, baço, rins, fígado e intestino, em ambos os híbridos analisados. Os parasitos Epystilis sp., Trichodina sp. e metacercária de digenéticos ocorrem com maior frequência nos dois híbridos, nas fases de pós-larvas e alevinos. Há maior prevalência e diversidade de parasitos na fase de alevinagem dos híbridos estudados.

  4. Observation of atmospheric aerosols at Mt. Hua and Mt. Tai in central and east China during spring 2009 – Part 2: Impact of dust storm on organic aerosol composition and size distribution

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    G. H. Wang

    2012-05-01

    Full Text Available PM10 and size-resolved particles (9-stage were simultaneously collected at Mt. Hua and Mt. Tai in central and east China during the spring of 2009 including a massive dust storm occurring on 24 April (named as DS II, and determined for organic compounds to investigate the impact of dust storm on organic aerosols. High molecular weight (HMW n-alkanes, fatty acids, and fatty alcohols and trehalose sharply increased and almost entirely stayed in coarse particles when dust storm was present, suggesting that high level of organic aerosols in the mountain atmospheres during the event largely originated from Gobi desert plants. However, most anthropogenic aerosols (e.g. PAHs, and aromatic and dicarboxylic acids during the event significantly decreased due to a dilution effect, indicating that anthropogenic aerosols in the mountain atmospheres during the nonevent period largely originated from local/regional sources rather than from long-range transport. Trehalose, a metabolism product enriched in biota in dry conditions, was 62 ± 78 and 421 ± 181 ng m−3 at Mt. Hua and Mt. Tai during DS II, 10–30 times higher than that in the nonevent time, indicating that trehalose may be a tracer for dust emissions from Gobi desert regions. Molecular compositions of organic aerosols in the mountain samples demonstrate that domestic coal burning is still the major source of PAHs in China.

    n-Alkanes and fatty acids showed a bimodal size distribution during the nonevent with a major peak in fine mode (<2.1 μm and a small peak in coarse mode (>2.1 μm. The coarse mode significantly increased and even dominated over the whole size range when dust was present. Glucose and trehalose were also dominant in the coarse mode especially in the DS II time. PAHs and levoglucosan concentrated in fine particles with no significant changes in size distribution when dust storm occurred. However, phthalic and succinic acids showed

  5. Migration of some metals in the ecosystem of the Caspian sea

    Science.gov (United States)

    Chaplygin, Wladimir A.; Tanasova, Anastasia S.; Ershova, Tatiana S.; Zaitsev, Vyacheslav F.; Bech, Jaume; Roca, Núria

    2017-04-01

    The content of heavy metals in aquatic organisms of the Caspian sea is connected with the increase of anthropogenic load on aqueous ecosystems, what leads to the disruption of the natural cycle of chemical elements. Heavy metals in small concentrations are included in an organism and are involved in various metabolic processes. One of the reasons for the high content of metals in the body of hydrobionts is the accumulation of the last in the food web and functional disturbance in all parts of the ecosystem. The aim of this work was to trace the migration of some metals in trophic chains in the ecosystem of the Caspian sea. The objects of the study were: various types of soils of the Caspian sea molluscs of the genus Didacna, fish - gobies ceneйcTвa Gobiidae and liver of Russian sturgeon Acipenser gueldenstaedtii, mammal - the liver of the Caspian seal Phoca caspica. The main burden of the accumulation of trace elements takes on the liver, which is a functional depot of many metals and is characterized by high metabolic activity in which there is a filtering and transformation of substances. The content of heavy metals in the objects of study were determined by atomic absorption method. The results are presented in mg/kg dry matter. The results showed that the level of accumulation of heavy metals in different types of soils of the Caspian sea was within the limits of environmental standards for bottom sediments taken in the Netherlands (2009) and heavy metal concentrations in silt and sand soil were below background values (according Verkhnevolzhskaya exploration of the enterprise and the Institute of water problems Russian Academy of Sciences, Russia). It should be noted that silty and sandy soils have a similar distribution pattern of heavy metals. A number of decrease the content of heavy metals in different soils of the Caspian sea were as follows: Silty and sandy soils: Zn>Ni>Pb>Co>Cd>Hg. The metals content in mollusks decreases in the series: Zn

  6. Dust vertical profile impact on global radiative forcing estimation using a coupled chemical-transport–radiative-transfer model

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    L. Zhang

    2013-07-01

    FLG vertical profiles are most significant over the Gobi desert with a value of about 1.1 W m−2. The radiative forcing effect of dust particles is more pronounced at the surface over the Sahara and Gobi deserts by using FLG vertical profile, while it is less significant over the downwind area of Eastern Asia.

  7. Variabilité selon le captureur de l'efficacité de répulsifs à base d'huiles végétales dans la protection individuelle contre les piqûres de Simulium damnosum s. l.

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    Sylla M.

    2002-12-01

    Full Text Available Dans le présent article, nous faisons état de la variabilité selon le captureur de l'efficacité de répulsifs à base d'huiles végétales appliquées sur la peau contre les piqûres de Simulium damnosum s. l. Les expérimentations ont été effectuées en zones de savane (Chaussée-Niaka et de forêt (Soubré de Côte d'Ivoire. Les formulations (lotions, crèmes] testées lors de ces travaux ont été obtenues à partir d'huiles d'amande de palme (Elaeis guineensis, de coco (Cocos nucifera et de gobi (Carapa procera. La technique classique de capture sur homme à l'aide de tubes à hémolyse en matière plastique a été utilisée. Pour chaque journée d'expérimentation, un captureur non traité (jambes non enduites de répulsif servait de témoin. Les résultats indiquent qu'en savane, quels que soient le répulsif et le captureur, la densité simulidienne se situait de 1 à 4, 1 à 6 et de 2 à 10 simulies par homme et par jour lorsque le captureur était respectivement protégé avec le coco, le palmiste et le gobi. Avec les mêmes répulsifs, en zone de forêt, l'agressivité simulidienne variait de 9 à 16, de 2 à 30 et de 8 à 49 piqûres par jour. En comparaison, le témoin recevait de 67 à 90 et de 310 à 533 piqûres par jour, respectivement en zones de savane et de forêt. Malgré les variations importantes dans le nombre de simulies capturées en fonction du captureur choisi, nos résultats montrent que quels que soient le répulsif et l'espèce simulidienne, une protection similaire est conférée à tous les captureurs. Ils indiquent également que le recours à des substances naturelles locales, utilisées comme répulsifs en application dermique, est l'une des meilleures méthodes de protection personnelle contre les simulies.

  8. Asian dust transport during the springtime of year 2001 and 2002 with a nested version of dust transport model

    Science.gov (United States)

    Uno, I.; Satake, S.; Hara, Y.; Takemura, T.; Wang, Z.; Carmichael, G. R.

    2002-12-01

    Number of yellow sand (Kosa) observation has been surprisingly increasing in Japan and Korea since 2000. Especially extremely high PM10 concentration (exceeding 0.5mg/m3) was observed in Japan several times in 2002, so we have an urgent scientific and political need to forecast/reproduce the detailed dust emission, transport and deposition processes. Intensive modeling studies have already been conducted to examine transport of Sahara dust and its impact on global radiation budget. One of the important differences between the Sahara desert and the Asian desert (mainly Gobi Desert and Takla Makan Desert) is the elevation of the dust source. The averaged elevation of Gobi Desert is approximately 1500 to 2500 m. These deserts are surrounded by high mountains. Furthermore advance of the recent manmade desertification made complicated land use patches for the arid region in Inner Mongolia. Therefore the development of a high horizontal resolution dust model is highly required. In this study, we will report a newly developed nested version of the dust transport model (as a part of Chemical weather FORecasting System; CFORS) in order to have a better understanding of Asian springtime heady dust episode. Here, CFORS is a multi-tracer, on-line, system built within the RAMS mesoscale meteorological model. A unique feature of nested CFORS is that multiple tracers are run on-line in RAMS under the two-way nesting, so that all the fine-scale on-line meteorological information such as 3-D winds, boundary-layer turbulence, surface fluxes and precipitation amount are directly used by the dust emission and transport at every time step. As a result, nested-CFORS produces with high time resolution 3-dimensional fields of dust distributions and major meteorological parameters under the nesting capability of RAMS. In this work, the dust transport model simulation with the nested-CFORS was conducted between March and April of the years 2001 and 2002, respectively. The sensititivy

  9. Preliminary Result of Geophysical Some Studieson the Nariinsukhait Coal Deposit

    Science.gov (United States)

    Norov, B.; Purevjav, N.; Roy, D. K., Sr.

    2017-12-01

    Nariinsukhait coal deposit has a strategic importance on Mongolian national economic development. The deposit is located in Gurvan-tes of the Umnu-gobi province, as 849 km south-west away from Ulaanbaatar. The deposit in geographically, belongs to Gobi Altai region region of the Altai mountain region. The area contains Permian, Cretaceous, Jurassic, Triassic age of sediments. Sediments are red or sedimentary cover on some part of area (Minjin. Ch., Batnyam. D., Rentsendorj. S (Baatarkhuyag. A., Altantsetseg. D., 2015). The coal deposit is located in the center portion of the Nariinsukhait basin. The age of coal hosted sedimentary rock is Jurassic estimated by Paleo-botanic methodology, using examination of a total 59 kind of plants, 288 pollen grains (Baatarkhuyag. A., Altantsetseg. D., 2015). The thickness of coal hosted sedimentary sequence is approximately 1105.5m and named as Orgilohbulag formation. In case of geophysical exploration, preliminary interpretation of the coal basin has been done by 3 geophysical methodologies which commonly applying during exploration stage of coal. The interpretations are given below. Natural Gamma Sonde /NGRS 4140/: use to determine natural gamma activation on rock by radionuclides content (238U; 235U; 232Th; 40K). During measurements well contrasted coal bedding and, value indicate between 0-15cps. And depending on the rock type it has been changed, in case of siltstone, argillite, conglomerate value fluctuated between 15-40cps. However, those rocks natural gamma values are difference little, therefore not showing much contrast between rock types. Formation Density Sonde Version B /FDSB 4036/: The Nariinsukhait coal deposit Open holes and protective pipes of density is 0.5-1.5 g/cm3, 1.2-2.3 g/cm3 respectively. Not well contrasted during measurement due to some of sedimentary rock density range is so low as such sandstone, siltstone, and conglomerate. Therefore, applied resistivity methodology and done interpretation. DLL3

  10. From Desert to Dessert: Why Australian Dust Matters.

    Science.gov (United States)

    Hunter, K. A.; Mackie, D. S.; Boyd, P. W.; McTainsh, G. H.

    2006-12-01

    The growth of some types of phytoplankton in several parts of the world ocean, including much of the Southern Ocean, is limited by the supply of iron. Large Australian dust storms uplift, transport and abrade soils, to produce aeolian dust that is a significant source iron to the Southern Ocean. Atmospheric processes that enhance the dissolution of iron from aeolian dusts are of interest and have been studied for material from major dust producing regions like the Sahara, Gobi and Australian deserts; the reported solubility of iron from aeolian dusts ranges from <0.01% to 80%. The characteristic red soils, sands and dusts from Australia are generally believed to consist of quartz grains with a coating of fine grains and crystals of iron oxides, primarily hematite and goethite. The precise mineralogy of soil and dust grain coatings is poorly understood and it also not well known how the coatings are altered during uplift and transport to the ocean. Current models to understand the processes operating during the transport and atmospheric processing of dust include some generalisations and simplifications that are not always warranted and our work has shown the overlooked complexity of the system. Models for aeolian-iron dissolution based on Northern Hemisphere data commonly include the pollutants SOx and NOx. The modern Southern Hemisphere is less polluted and thus resembles past environmental systems. The dissolution of iron from soils of the Saharan, Gobi and Australian deserts in the presence of protons only (i.e. without SOx and NOx) occurs in two phases. The first, faster phase, representing up to 20% of total iron is via a surface-controlled mechanism. The rate determining variable is the exposed surface area of the iron oxides and not the size of the underlying quartz grain. The second, slower, phase of dissolution occurs via the transport-controlled formation of a leached layer. During the simulated aeolian abrasion of Australian soils from dust producing

  11. Diurnal and seasonal variations in carbon dioxide exchange in ecosystems in the Zhangye oasis area, Northwest China.

    Directory of Open Access Journals (Sweden)

    Lei Zhang

    Full Text Available Quantifying carbon dioxide exchange and understanding the response of key environmental factors in various ecosystems are critical to understanding regional carbon budgets and ecosystem behaviors. For this study, CO2 fluxes were measured in a variety of ecosystems with an eddy covariance observation matrix between June 2012 and September 2012 in the Zhangye oasis area of Northwest China. The results show distinct diurnal variations in the CO2 fluxes in vegetable field, orchard, wetland, and maize cropland. Diurnal variations of CO2 fluxes were not obvious, and their values approached zero in the sandy desert, desert steppe, and Gobi ecosystems. Additionally, daily variations in the Gross Primary Production (GPP, Ecosystem Respiration (Reco and Net Ecosystem Exchange (NEE were not obvious in the sandy desert, desert steppe, and Gobi ecosystems. In contrast, the distributions of the GPP, Reco, and NEE show significant daily variations, that are closely related to the development of vegetation in the maize, wetland, orchard, and vegetable field ecosystems. All of the ecosystems are characterized by their carbon absorption during the observation period. The ability to absorb CO2 differed significantly among the tested ecosystems. We also used the Michaelis-Menten equation and exponential curve fitting methods to analyze the impact of Photosynthetically Active Radiation (PAR on the daytime CO2 flux and impact of air temperature on Reco at night. The results show that PAR is the dominant factor in controlling photosynthesis with limited solar radiation, and daytime CO2 assimilation increases rapidly with PAR. Additionally, the carbon assimilation rate was found to increase slowly with high solar radiation. The light response parameters changed with each growth stage for all of the vegetation types, and higher light response values were observed during months or stages when the plants grew quickly. Light saturation points are different for different

  12. Shelter effect efficacy of sand fences: A comparison of systems in a wind tunnel

    Science.gov (United States)

    Wang, Tao; Qu, Jianjun; Ling, Yuquan; Liu, Benli; Xiao, Jianhua

    2018-02-01

    The Lanzhou-Xinjiang High-speed Railway runs through an expansive wind area in the Gobi Desert and blown-sand disasters are a critical issue affecting its operation. To strengthen the blown-sand disaster shelter systems along the railway, the shelter effects of punching plate and wire mesh fences with approximately equal porosity (48%) were simulated in a wind tunnel. The experimental results showed that the wind velocity was reduced to a higher extent by the punching plate fence than by the wire mesh fence. When a single row of sand fencing was used, the wind velocity reduction coefficient (Rcz) values downwind of the punching plate fence and wire mesh fence reached 71.77% and 39.37%, respectively. When double rows of sand fencing were used, the Rcz values downwind of the punching plate and wire mesh fences were approximately 87.48% and 60.81%, respectively. For the flow field structure on the leeward side of the fencing, the deceleration zone behind the punching plate fence was more pronounced than that behind the wire mesh fence. The vortex zone was not obvious and the reverse flow disappeared for both types of fences, which indicates that the turbulent intensity was small. The sand-trapping efficiency of the wire mesh fence was close to that of punching plate fence. When a single row of sand fencing was set up, the total mass flux density decreased, on average, by 65.85% downwind of the wire mesh fence, and 75.06% downwind of the punching plate fence; when double rows of sand fencing were present, the total mass flux density decreased, on average, by 84.53% downwind of the wire mesh fence and 84.51% downwind of the punching plate fence. In addition, the wind-proof efficiency and the sand-proof efficiency of the punching plate fence and the wire mesh fence decreased with increasing wind velocities. Consequently, punching plate and wire mesh fences may effectively control the sand hazard in the expansive wind area of the Gobi Desert.

  13. Acoustics of fish shelters: frequency response and gain properties.

    Science.gov (United States)

    Lugli, Marco

    2012-11-01

    Many teleosts emit sounds from cavities beneath stones and other types of submerged objects, yet the acoustical properties of fish shelters are virtually unexplored. This study examines the gain properties of shelters commonly used by Mediterranean gobies as hiding places and/or nest sites in the field (flat stones, shells belonging to five bivalve species), or within aquarium tanks (tunnel-shaped plastic covers, concrete blocks, concrete cylinder pipe, halves of terracotta flower pots). All shelters were acoustically stimulated using a small underwater buzzer, placed inside or around the shelter to mimic a fish calling from the nest site, and different types of driving stimuli (white noise, pure tones, and artificial pulse trains). Results showed the presence of significant amplitude gain (3-18 dB) at frequencies in the range 100-150 Hz in all types of natural shelters but one (Mytilus), terracotta flower pots, and concrete blocks. Gain was higher for stones and artificial shelters than for shells. Gain peak amplitude increased with the weight of stones and shells. Conclusions were verified by performing analogous acoustical tests on flat stones in the stream. Results draw attention to the use of suitable shelters for proper recording of sounds produced by fishes kept within laboratory aquaria.

  14. Regional prediction of carbon isotopes in soil carbonates for Asian dust source tracer

    Science.gov (United States)

    Chen, Bing; Cui, Xinjuan; Wang, Yaqiang

    2016-10-01

    Dust particles emitted from deserts and semi-arid lands in northern China cause particulate pollution that increases the burden of disease particularly for urban population in East Asia. The stable carbon isotopes (δ13C) of carbonates in soils and dust aerosols in northern China were investigated. We found that the δ13C of carbonates in surface soils in northern China showed clearly the negative correlation (R2 = 0.73) with Normalized Difference Vegetation Index (NDVI). Using Moderate Resolution Imaging Spectroradiometer (MODIS) satellite-derived NDVI, we predicted the regional distribution of δ13C of soil carbonates in deserts, sandy lands, and steppe areas. The predictions show the mean δ13C of -0.4 ± 0.7‰ in soil carbonates in Taklimakan Desert and Gobi Deserts, and the isotope values decrease to -3.3 ± 1.1‰ in sandy lands. The increase in vegetation coverage depletes 13C in soil carbonates, thus the steppe areas are predicted by the lowest δ13C levels (-8.1 ± 1.7‰). The measurements of atmospheric dust samples at eight sites showed that the Asian dust sources were well assigned by the 13C mapping in surface soils. Predicting 13C in large geographical areas with fine resolution offers a cost-effective tracer to monitor dust emissions from sandy lands and steppe areas which show an increasing role in Asian dust loading driven by climate change and human activities.

  15. Agonistic reciprocity is associated with reduced male reproductive success within haremic social networks.

    Science.gov (United States)

    Solomon-Lane, Tessa K; Pradhan, Devaleena S; Willis, Madelyne C; Grober, Matthew S

    2015-07-22

    While individual variation in social behaviour is ubiquitous and causes social groups to differ in structure, how these structural differences affect fitness remains largely unknown. We used social network analysis of replicate bluebanded goby (Lythrypnus dalli) harems to identify the reproductive correlates of social network structure. In stable groups, we quantified agonistic behaviour, reproduction and steroid hormones, which can both affect and respond to social/reproductive cues. We identified distinct, optimal social structures associated with different reproductive measures. Male hatching success (HS) was negatively associated with agonistic reciprocity, a network structure that describes whether subordinates 'reciprocated' agonism received from dominants. Egg laying was associated with the individual network positions of the male and dominant female. Thus, males face a trade-off between promoting structures that facilitate egg laying versus HS. Whether this reproductive conflict is avoidable remains to be determined. We also identified different social and/or reproductive roles for 11-ketotestosterone, 17β-oestradiol and cortisol, suggesting that specific neuroendocrine mechanisms may underlie connections between network structure and fitness. This is one of the first investigations of the reproductive and neuroendocrine correlates of social behaviour and network structure in replicate, naturalistic social groups and supports network structure as an important target for natural selection. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

  16. Diet of Ctenogobius shufeldti (Jordan and Eigenmann, 1887 (Teleostei, Gobiidae in Guaratuba Bay, subtropical west Atlantic

    Directory of Open Access Journals (Sweden)

    Diego Zanlorenzi

    2011-02-01

    Full Text Available The diet composition of the American freshwater goby, Ctenogobius shufeldti, was investigated in an estuarine area and two of its tributaries. 397 individuals, total length from 21 to 70mm, were sampled over a period of 12 months and their stomach contents were analysed by the Frequency of Occurrence and Number of Points methods. According to the Alimentary Index, diet was constituted mainly by Ostracoda (IA=50.51 and Tanaidacea (IA=40.85, and secondarily by Gastropoda (IA=1.21, Amphipoda (IA=0.10, Isopoda (IA=0.01, Cirripedia (IA=0.01, Decapoda larvae (IA=0.01, Insecta (IA=0.01, Chlorophyta (IA=2.15 and Rodophyta (IA=0.15 filamentous algae, and plants (IA=4.99. Diversity of diet was higher in rivers than in the Bay. Except for Decapoda larvae, items found in the two rivers were the same. In the Bay, Amphipoda and Cirripedia were not found. Previous to this research, the filamentous algae Chlorophyta and Rodophyta had not been noted in the diet of this species in estuaries close to Guaratuba. In view of this, and regarding the possible roles played by cryptobenthic fish species in aquatic communities (Depczynski and Bellwood, 2003, it is concluded that C. shufeldti takes part in trophic dynamics feeding on benthic organisms as well as on algae, a behaviour that can result from both marine and continental influences existing in the region.

  17. Digitization of uranium deposit information in basin. A new strategy of ISL sandstone-type uranium deposits exploration

    International Nuclear Information System (INIS)

    Tan Chenglong

    2006-01-01

    The discovered ISL sandstone-type uranium deposits in the entire world are mostly blind deposits, many of them occur in bleak desert, gobi desert, and semi-hilly land area. Exploration methods for these deposits mainly depend on great and systematic drilling. There are many large-medium size Meso-Cenozoic sedimentary basins in northern China, and over twenty of them are thick overburden basins which are mostly the virgin land for ISL sandstone-type uranium deposit. Due to the comprehensive national power, geological background, uranium exploration ability, great and systematic drilling is not favorable for prospecting ISL sandstone-type uranium deposit in China. According to the exploration and prospecting experiences for mineral ore bodies at home and abroad, uranium information mapping based on geochemical survey of the basins is a new strategy for ISL sandstone-type uranium deposits. It is an economic, practical, fast and effective method, and has been manifested by the performing information digitization for oil and gas resources, gold mineral resources in China and the mapping of uranium information for whole Europe continent. (authors)

  18. Customizing a rangefinder for community-based wildlife conservation initiatives

    Science.gov (United States)

    Ransom, Jason I.

    2011-01-01

    Population size of many threatened and endangered species is relatively unknown because estimating animal abundance in remote parts of the world, without access to aircraft for surveying vast areas, is a scientific challenge with few proposed solutions. One option is to enlist local community members and train them in data collection for large line transect or point count surveys, but financial and sometimes technological constraints prevent access to the necessary equipment and training for accurately quantifying distance measurements. Such measurements are paramount for generating reliable estimates of animal density. This problem was overcome in a survey of Asiatic wild ass (Equus hemionus) in the Great Gobi B Strictly Protected Area, Mongolia, by converting an inexpensive optical sporting rangefinder into a species-specific rangefinder with visual-based categorical labels. Accuracy trials concluded 96.86% of 350 distance measures matched those from a laser rangefinder. This simple customized optic subsequently allowed for a large group of minimally-trained observers to simultaneously record quantitative measures of distance, despite language, education, and skill differences among the diverse group. The large community-based effort actively engaged local residents in species conservation by including them as the foundation for collecting scientific data.

  19. Direct radiative effects of dust aerosols emitted from the Tibetan Plateau on the East Asian summer monsoon - a regional climate model simulation

    Science.gov (United States)

    Sun, Hui; Liu, Xiaodong; Pan, Zaitao

    2017-11-01

    While dust aerosols emitted from major Asian sources such as Taklimakan and Gobi deserts have been shown to have strong effect on Asian monsoon and climate, the role of dust emitted from Tibetan Plateau (TP) itself, where aerosols can directly interact with the TP heat pump because of their physical proximity both in location and elevation, has not been examined. This study uses the dust-coupled RegCM4.1 regional climate model (RCM) to simulate the spatiotemporal distribution of dust aerosols originating within the TP and their radiative effects on the East Asian summer monsoon (EASM) during both heavy and light dust years. Two 20-year simulations with and without the dust emission from TP showed that direct radiative cooling in the mid-troposphere induced by the TP locally produced dust aerosols resulted in an overall anticyclonic circulation anomaly in the low troposphere centered over the TP region. The northeasterly anomaly in the EASM region reduces its strength considerably. The simulations found a significant negative correlation between the TP column dust load produced by local emissions and the corresponding anomaly in the EASM index (r = -0.46). The locally generated TP dust can cause surface cooling far downstream in Bohai Gulf and the China-North Korea border area through stationary Rossby wave propagation. Although dust from within TP (mainly Qaidam Basin) is a relatively small portion of total Asian aerosols, its impacts on Asian monsoon and climate seems disproportionately large, likely owning to its higher elevation within TP itself.

  20. Establishment of a cell line from kidney of seabass, Lates calcarifer (Bloch

    Directory of Open Access Journals (Sweden)

    Phromkunthong, W.

    2003-01-01

    Full Text Available Primary cell culture from caudal fin and kidney of seabass (Lates calcarifer Bloch using tissue explant method were cultured in three different medias with various salt concentrations. Only seabass kidney (SK cells grew well in Leibovitze's-15 medium containing 8 g/l of NaCl supplemented with 10 % fetal bovine serum at an optimum temperature of 25 oC. Over a period of 24 months, SK cells were subcultured over than 75 passages and exhibited epithelial-like cells. The chromosome number of SK cells was 42. The cells were found to be free from bacterial, fungal and mycoplasma contamination. Seabass cells can be kept at -80 oC and/or in liquid nitrogen (-196 oC for at least 24 months with a survival rate of 83.20 and 74.50 %, respectively. Nine fish viruses were tested for their infectivity and this SK cells were susceptible to sand goby virus (SGV, chub reovirus (CRV, snake-head rhabdovirus (SHRV, red seabream iridovirus (RSIV, seabass iridovirus (SIV and grouper iridovirus-2 (GIV-2.

  1. Snow and Dust over Inner Mongolia

    Science.gov (United States)

    2002-01-01

    A severe snow-and-sand storm hit an 80,000 square-mile (205,000-square-km) stretch of the Chinese province of Mongolia on New Year's Eve, killing 21 people and leaving thousands of people to face possible starvation. The affected area is located about 250 miles (400 km) northwest of Beijing. It is the worst snowstorm to hit the region in more than 50 years. Lasting about 3 days, the storm dumped 24 inches (60 cm) of snow mixed with sand from the Gobi Desert, stranding many residents in deep drifts. The Chinese Red Cross reports that almost 1 million people were affected by the storm and at least 10,000 head of livestock are confirmed dead. As many as 120,000 residents are in need of food and other supplies. The Sea-viewing Wide Field-of-view Sensor (SeaWiFS), flying aboard the OrbView-2 satellite, acquired this image of the storm on January 2, 2001, as it approached China's eastern provinces. You can see storm clouds (white pixels) and windblown dust (brownish pixels) crossing the Yellow Sea and East China Sea toward Japan and the western Pacific. Provided by the SeaWiFS Project, NASA/Goddard Space Flight Center, and ORBIMAGE

  2. Impacts of aquatic nonindigenous invasive species on the Lake Erie ecosystem

    Science.gov (United States)

    Austen, Madeline J.W.; Ciborowski, Jan J.H.; Corkum, Lynda D.; Johnson, Tim B.; MacIsaac, Hugh J.; Metcalfe-Smith, Janice L.; Schloesser, Donald W.; George, Sandra E.

    2002-01-01

    Lake Erie is particularly vulnerable to the introduction and establishment of aquatic nonindigenous invasive species (NIS) populations. A minimum of 144 aquatic NIS have been recorded in the Lake Erie basin including several species [e.g., Eurasian watermilfoil (Myriophyllum spicatum); zebra mussel (Dreissena polymorpha); quagga mussel (Dreissena bugensis); an amphipod (Echinogammarus ischnus); round goby (Neogobius melanostomus); and sea lamprey (Petromyzon marinus)] that have had discernible impacts on the lake's ecology. NIS pose threats to the Lake Erie ecosystem for a variety of reasons including their ability to proliferate quickly, compete with native species, and transfer contaminants (e.g., PCBs) and disease through the food web. Six of the 14 beneficial use impairments listed in Annex 2 of the Great Lakes Water Quality Agreement are impaired in Lake Erie, in part as a result of the introduction of NIS. The Lake Erie Lakewide Management Plan (LaMP) has adopted an ecosystem approach to restore beneficial use impairments in the lake. Furthermore, a research consortium, known as the Lake Erie Millennium Network, is working alongside the LaMP, to address research problems regarding NIS, the loss of habitat, and the role of contaminants in the Lake Erie ecosystem.

  3. Hypoxia tolerance in coral-reef triggerfishes (Balistidae)

    Science.gov (United States)

    Wong, Corrie C.; Drazen, Jeffrey C.; Callan, Chatham K.; Korsmeyer, Keith E.

    2018-03-01

    Despite high rates of photosynthetic oxygen production during the day, the warm waters of coral reefs are susceptible to hypoxia at night due to elevated respiration rates at higher temperatures that also reduce the solubility of oxygen. Hypoxia may be a challenge for coral-reef fish that hide in the reef to avoid predators at night. Triggerfishes (Balistidae) are found in a variety of reef habitats, but they also are known to find refuge in reef crevices and holes at night, which may expose them to hypoxic conditions. The critical oxygen tension ( P crit) was determined as the point below which oxygen uptake could not be maintained to support standard metabolic rate (SMR) for five species of triggerfish. The triggerfishes exhibited similar levels of hypoxia tolerance as other coral-reef and coastal marine fishes that encounter low oxygen levels in their environment. Two species, Rhinecanthus rectangulus and R. aculeatus, had the lowest P crit ( 3.0 kPa O2), comparable to the most hypoxia-tolerant obligate coral-dwelling gobies, while Odonus niger and Sufflamen bursa were moderately tolerant to hypoxia ( P crit 4.5 kPa), and Xanthichthys auromarginatus was intermediate ( P crit 3.7 kPa). These differences in P crit were not due to differences in oxygen demand, as all the species had a similar SMR once mass differences were taken into account. The results suggest that triggerfish species are adapted for different levels of hypoxia exposure during nocturnal sheltering within the reef.

  4. Depth distribution and abundance of a coral-associated reef fish: roles of recruitment and post-recruitment processes

    Science.gov (United States)

    Smallhorn-West, Patrick F.; Bridge, Tom C. L.; Munday, Philip L.; Jones, Geoffrey P.

    2017-03-01

    The abundance of many reef fish species varies with depth, but the demographic processes influencing this pattern remain unclear. Furthermore, while the distribution of highly specialized reef fish often closely matches that of their habitat, it is unclear whether changes in distribution patterns over depth are the result of changes in habitat availability or independent depth-related changes in population parameters such as recruitment and mortality. Here, we show that depth-related patterns in the distribution of the coral-associated goby, Paragobiodon xanthosoma, are strongly related to changes in recruitment and performance (growth and survival). Depth-stratified surveys showed that while the coral host, Seriatopora hystrix, extended into deeper water (>20 m), habitat use by P. xanthosoma declined with depth and both adult and juvenile P. xanthosoma were absent below 20 m. Standardization of S. hystrix abundance at three depths (5, 15 and 30 m) demonstrated that recruitment of P. xanthosoma was not determined by the availability of its habitat. Reciprocal transplantation of P. xanthosoma to S. hystrix colonies among three depths (5, 15 and 30 m) then established that individual performance (survival and growth) was lowest in deeper water; mortality was three times higher and growth greatly reduced in individuals transplanted to 30 m. Individuals collected from 15 m also exhibited growth rates 50% lower than fish from shallow depths. These results indicate that the depth distribution of this species is limited not by the availability of its coral habitat, but by demographic costs associated with living in deeper water.

  5. Application of a Deep Neural Network to Metabolomics Studies and Its Performance in Determining Important Variables.

    Science.gov (United States)

    Date, Yasuhiro; Kikuchi, Jun

    2018-02-06

    Deep neural networks (DNNs), which are kinds of the machine learning approaches, are powerful tools for analyzing big sets of data derived from biological and environmental systems. However, DNNs are not applicable to metabolomics studies because they have difficulty in identifying contribution factors, e.g., biomarkers, in constructed classification and regression models. In this paper, we describe an improved DNN-based analytical approach that incorporates an importance estimation for each variable using a mean decrease accuracy (MDA) calculation, which is based on a permutation algorithm; this approach is called DNN-MDA. The performance of the DNN-MDA approach was evaluated using a data set of metabolic profiles derived from yellowfin goby that lived in various rivers throughout Japan. Its performance was compared with that of conventional multivariate and machine learning methods, and the DNN-MDA approach was found to have the best classification accuracy (97.8%) among the examined methods. In addition to this, the DNN-MDA approach facilitated the identification of important variables such as trimethylamine N-oxide, inosinic acid, and glycine, which were characteristic metabolites that contributed to the discrimination of the geographical differences between fish caught in the Kanto region and those caught in other regions. As a result, the DNN-MDA approach is a useful and powerful tool for determining the geographical origins of specimens and identifying their biomarkers in metabolomics studies that are conducted in biological and environmental systems.

  6. Light scattering and absorption properties of dust particles retrieved from satellite measurements

    International Nuclear Information System (INIS)

    Hu, R.-M.; Sokhi, R.S.

    2009-01-01

    We use the radiative transfer model and chemistry transport model to improve our retrievals of dust optical properties from satellite measurements. The optical depth and absorbing optical depth of mineral dust can be obtained from our improved retrieval algorithm. We find the nonsphericity and absorption of dust particles strongly affect the scattering signatures such as phase function and polarization at the ultraviolet wavelengths. From our retrieval results, we find the high levels of dust concentration occurred over most desert regions such as Saharan and Gobi deserts. The dust absorption is found to be sensitive to mineral chemical composition, particularly the fraction of strongly absorbing dust particles. The enhancement of polarization at the scattering angles exceeding 120 0 is found for the nonspherical dust particles. If the polarization is neglected in the radiative transfer calculation, a maximum 50 percent error is introduced for the case of forward scattering and 25 percent error for the case of backscattering. We suggest that the application of polarimeter at the ultraviolet wavelengths has the great potential to improve the satellite retrievals of dust properties. Using refined optical model and radiative transfer model to calculate the solar radiative forcing of dust aerosols can reduce the uncertainties in aerosol radiative forcing assessment.

  7. Responses of three different ecotypes of reed (Phragmites communis Trin.) to their natural habitats: leaf surface micro-morphology, anatomy, chloroplast ultrastructure and physio-chemical characteristics.

    Science.gov (United States)

    Liu, Yubing; Li, Xinrong; Liu, Meiling; Cao, Bo; Tan, Huijuan; Wang, Jin; Li, Xiaojun

    2012-02-01

    The adaptational characteristics due to long-term adaptation in the natural habitats of common reed (Phragmites communis Trin.) contrasted considerably among three different ecotypes: dune reed (DR), Gobi salt reed (GSR) and swamp reed (SR). The micromorphologies of leaf adaxial surfaces showed tapered setae and a non-smooth surface in DR, compound papillose structures with wax and hairs in GSR, but only papillose structures for the smooth surface of SR. Anatomical analysis showed that DR and GSR had higher bundle-sheath cell areas and a lower xylem/phloem ratio than SR. There were many sclerenchyma cells in vascular bundle of DR and GSR and crystal idioblasts in all ecotypes. Chloroplasts had ellipsoid shape in SR, but they were attached to the cell wall with oblong shape and contained many starch grains in DR and GSR. Higher concentrations of NO, H(2)O(2) and lipid peroxidation, higher ratio of carotenoids/chlorophyll and higher activities in T-AOC and SOD were found in DR and GSR. Na(+)/K(+)-ATPase and Ca(2+)/Mg(2+)-ATPase activities were greatest in GSR. All these data suggested that the greater relative stress tolerance of DR and GSR was due to a combination of morpho-anatomical adaptational characteristics and physio-chemical responses, and indicated the different mechanisms in their respective natural habitats. Copyright © 2011 Elsevier Masson SAS. All rights reserved.

  8. Both male and female identity influence variation in male signalling effort

    Directory of Open Access Journals (Sweden)

    Svensson P Andreas

    2011-08-01

    Full Text Available Abstract Background Male sexual displays play an important role in sexual selection by affecting reproductive success. However, for such displays to be useful for female mate choice, courtship should vary more among than within individual males. In this regard, a potentially important source of within male variation is adjustment of male courtship effort in response to female traits. Accordingly, we set out to dissect sources of variation in male courtship effort in a fish, the desert goby (Chlamydogobius eremius. We did so by designing an experiment that allowed simultaneous estimation of within and between male variation in courtship, while also assessing the importance of the males and females as sources of courtship variation. Results Although males adjusted their courtship depending on the identity of the female (a potentially important source of within-male variation, among-male differences were considerably greater. In addition, male courtship effort towards a pair of females was highly repeatable over a short time frame. Conclusion Despite the plasticity in male courtship effort, courtship displays had the potential to reliably convey information about the male to mate-searching females. Our experiment therefore underscores the importance of addressing the different sources contributing to variation in the expression of sexually-selected traits.

  9. Levels of Platinum Group Metals in Selected Species (Sarotherodon melanotheron, Chonophorus lateristriga, Macrobrachium vollenhovenii and Crassostrea tulipa in Some Estuaries and Lagoons Along the Coast of Ghana

    Directory of Open Access Journals (Sweden)

    D. K. Essumang

    2010-01-01

    Full Text Available The use of some biota as bioindicators of heavy metal pollution has been demonstrated as particularly adequate due to their capacity of bioconcentration. This study evaluated the levels of platinum group metals (PGMs in some selected species along the coastal belt of Ghana, using the neutron activation analysis (NAA method. The result was processed to evaluate pollution indices in order to map the distribution of the metals in those species in the lagoons and estuaries along the costal belt of Ghana. The analysis showed significant levels of all PGMs in blackchin tilapia (Sarotherodon melanotheron Cichlidae, brown goby (Chonophorus lateristriga Gobiidae, shrimp (Macrobrachium vollenhovenii Palaemonidae, and mangrove oysters (Crassostrea tulipa Ostreidae in the lagoons and river Pra estuary. However, the oysters showed an elevated mean concentration of 0.13 μ/g (dry weight Pd. From the pollution indices, most of the sampling sites registered mean contamination factor (CF values between 1.20 and 3.00 for Pt, Pd, and Rh. The pollution load index (PLI conducted also gave an average pollution index between 0.79 and 2.37, indicating progressive contamination levels. The results revealed that anthropogenic sources, industrial and hospital effluent, etc., together with vehicular emissions, could be the contributing factors to the deposition of PGMs along the Ghanaian coast.

  10. A collaborative approach for estimating terrestrial wildlife abundance

    Science.gov (United States)

    Ransom, Jason I.; Kaczensky, Petra; Lubow, Bruce C.; Ganbaatar, Oyunsaikhan; Altansukh, Nanjid

    2012-01-01

    Accurately estimating abundance of wildlife is critical for establishing effective conservation and management strategies. Aerial methodologies for estimating abundance are common in developed countries, but they are often impractical for remote areas of developing countries where many of the world's endangered and threatened fauna exist. The alternative terrestrial methodologies can be constrained by limitations on access, technology, and human resources, and have rarely been comprehensively conducted for large terrestrial mammals at landscape scales. We attempted to overcome these problems by incorporating local peoples into a simultaneous point count of Asiatic wild ass (Equus hemionus) and goitered gazelle (Gazella subgutturosa) across the Great Gobi B Strictly Protected Area, Mongolia. Paired observers collected abundance and covariate metrics at 50 observation points and we estimated population sizes using distance sampling theory, but also assessed individual observer error to examine potential bias introduced by the large number of minimally trained observers. We estimated 5671 (95% CI = 3611–8907) wild asses and 5909 (95% CI = 3762–9279) gazelle inhabited the 11,027 km2 study area at the time of our survey and found that the methodology developed was robust at absorbing the logistical challenges and wide range of observer abilities. This initiative serves as a functional model for estimating terrestrial wildlife abundance while integrating local people into scientific and conservation projects. This, in turn, creates vested interest in conservation by the people who are most influential in, and most affected by, the outcomes.

  11. Influence of salinity, competition and food supply on the growth of Gobiosoma robustum and Microgobius gulosus from Florida Bay, U. S. A.

    Science.gov (United States)

    Schofield, P.J.

    2004-01-01

    The code Gobiosoma robustum and clown Microgobius gulosus gobies were grown in the laboratory over 27 days at two salinities (5 and 35), two food levels [low (a fixed proportion of initial mass) and high (saturation)] and both with and without the presence of the other species. Both species exhibited greatest growth at the high food level and the low (5) salinity. Neither species was affected by the presence of the other species, and there were no overall differences in growth between the two species. Thus, the observed competitive superiority of G. robustum over M. gulosus does not seem to confer an advantage relative to feeding success. Furthermore, as growth of G. robustum was greater at the lower salinity, it is clear that some factor other than salinity is restricting this species from north-eastern Florida Bay. Additional work on the importance of predation and food resources in various regions of Florida Bay is needed to further evaluate the underlying mechanisms responsible for the bay-wide distribution of these species. ?? 2004 The Fisheries Society of the British Isles.

  12. A simplified Suomi NPP VIIRS dust detection algorithm

    Science.gov (United States)

    Yang, Yikun; Sun, Lin; Zhu, Jinshan; Wei, Jing; Su, Qinghua; Sun, Wenxiao; Liu, Fangwei; Shu, Meiyan

    2017-11-01

    Due to the complex characteristics of dust and sparse ground-based monitoring stations, dust monitoring is facing severe challenges, especially in dust storm-prone areas. Aim at constructing a high-precision dust storm detection model, a pixel database, consisted of dusts over a variety of typical feature types such as cloud, vegetation, Gobi and ice/snow, was constructed, and their distributions of reflectance and Brightness Temperatures (BT) were analysed, based on which, a new Simplified Dust Detection Algorithm (SDDA) for the Suomi National Polar-Orbiting Partnership Visible infrared Imaging Radiometer (NPP VIIRS) is proposed. NPP VIIRS images covering the northern China and Mongolian regions, where features serious dust storms, were selected to perform the dust detection experiments. The monitoring results were compared with the true colour composite images, and results showed that most of the dust areas can be accurately detected, except for fragmented thin dusts over bright surfaces. The dust ground-based measurements obtained from the Meteorological Information Comprehensive Analysis and Process System (MICAPS) and the Ozone Monitoring Instrument Aerosol Index (OMI AI) products were selected for comparison purposes. Results showed that the dust monitoring results agreed well in the spatial distribution with OMI AI dust products and the MICAPS ground-measured data with an average high accuracy of 83.10%. The SDDA is relatively robust and can realize automatic monitoring for dust storms.

  13. Numerical Modeling of 1997-2006 Asian Dust and Mass Budget Analysis in East Asia and West Pacific

    Science.gov (United States)

    Liu, M.; Westphal, D. L.

    2006-12-01

    East Asia has two of the Earth's major natural dust sources: the Taklamakan Desert in west China and the Gobi Desert in Mongolia and northwest China. Desertification has increased dust-erodible areas surrounding the deserts so the dust storm frequency has increased in the last few decades. Severe dust storms not only impact East Asia, but also can reach far beyond the continent, as did the dust clouds of April 1998, 2001 and 2005 that drifted over the Pacific Ocean and to North America. The US Navy's operational Coupled Ocean/Atmospheric Mesoscale Prediction System (COAMPS) is used to simulate the dust events for the springs of 1997 through 2006 at a resolution of one quarter of degree with multiple size bins. We use the modeled data to investigate the spatial and temporal dependence of dust emission, transport and deposition, and estimate the impacts of dust on environment. The distribution of dust plumes in area coverage and vertical depth is studied, as is the inter-annual variation of dust patterns from the different deserts of China and Mongolia, and the fluxes across the Pacific. It is found that PM10 is the dominant fraction particles over the continent and near the ocean, while PM2.5 becomes dominant in the boundary outflow along 170E. The details of analyzed model results will be presented at the meeting.

  14. [Imagination and creation: 1-hydroxyindole chemistry and the dream challenge].

    Science.gov (United States)

    Somei, Masanori

    2008-04-01

    We have had five dreams to challenge through our life. To meet our end, we needed imaginary compounds, 1-hydroxytryptophans. This review describes how we had conceived the 1-hydroxyindole hypothesis, how we created a general synthetic method for 1-hydroxyindoles after 20 years' research, and how we have developed the chemistry of 1-hydroxytryptophans with full of new findings and discoveries. During the period, we defined "the efficient synthesis" and "the ideal synthesis" consisting of originality rate (OR), intellectual property factor (IPF), and application potential factor (APF). For evaluating the originality and the efficiency of the synthetic research, these indexes are more effective than both citation index and impact factor. Taking advantage of our 1-hydroxyindole chemistry, we have achieved three "ideal syntheses" approximately with high OR, IPF, and APF values. The methods employ only conventional reagents and reaction conditions without using any protecting groups. These methods made possible to produce such intellectual properties as leads for an alpha(2)-blocker, an inhibitor of platelet aggregation, an anti-osteoporosis agent, and a promising medicine for combating desertification, changing Gobi desert to the tract with full of green plants. These would be suitable for realizing our five dreams. Chemical conversion of enmein to gibberellin A(15), four-step total synthesis of optically active ergot alkaloids, and various new reactions for the synthesis of 4-substituted indoles are also involved.

  15. Long-Term Variability of Airborne Asian Dust Observed from TOMS

    Science.gov (United States)

    Herman, J. R.; Hsu, N. C.; Seftor, C. J.; Holben, B. N.; Holben, B. N.; Einaudi, Franco (Technical Monitor)

    2001-01-01

    Recent studies suggest that airborne Asian dust may not only play an important role in the regional radiation budget, but also influence the air quality over North America through long-range transport. In this paper, we use satellite data to investigate the long-term variability of airborne Asian dust as well as the daily variation of the dust aerosol distribution. By combining the Total Ozone Mapping Spectrometer (TOMS) aerosol index with National Centers for Environmental Prediction (NCEP) wind data, our analysis shows a strong correlation between the generation of dust storms in the region and the passage of springtime weather fronts. This is consistent with earlier studies performed by other researchers. According to both the Nimbus-7 and Earth-Probe TOMS data the Takla Makan desert, the Gobi desert, and the and region of Inner Mongolia are major sources of the eastward-flowing airborne Asian dust. Heavily populated areas in eastern China (e.g., Beijing) are often on the primary path of the dust storms originating in these desert regions. The increasing desertification north of the Beijing region has served to exacerbate problems stemming from these storms. The time series derived from 20 years of TOMS aerosol index data shows the first significant satellite evidence of the atmospheric effect of increasing desertification, indicating that the amount of dust blown eastward has increased strongly during the past few years including the year 2000.

  16. Deinococcus gobiensis cold shock protein improves salt stress tolerance of escherichia coli

    International Nuclear Information System (INIS)

    Jiang Shijie; Wang Jin; Yang Mingkun; Chen Ming; Zhang Wei; Luo Xuegang

    2013-01-01

    The Deinococcus gobiensis I-0, an extremely radiation-resistant bacterium, isolated from the Gobi, has superior resistance to abiotic stress (e.g radiation, oxidation, dehydration and so on). The two cold-shock proteins encoded by csp1 (Dgo C A1136) and csp2 (Dgo P A0041) were identified in the complete genome sequence of D. gobiensis. In this study, we showed that D. gobiensis Csp1 protected Escherichia coli cells against cold shock and other abiotic stresses such as salt and osmotic shocks. The quantitative real-time PCR assay shows that the expression of trehalose synthase (otsA, otsB) was up-regulated remarkably under salt stress in the csp1-expressing strain, while no difference in the expression of the genes involved in trehalose degradation (treB and treC). The results suggested that Csp1 caused the accumulation of the trehalose was a major feature for improving tolerance to salt stress in E. coli. (authors)

  17. An exquisitely preserved troodontid theropod with new information on the palatal structure from the Upper Cretaceous of Mongolia

    Science.gov (United States)

    Tsuihiji, Takanobu; Barsbold, Rinchen; Watabe, Mahito; Tsogtbaatar, Khishigjav; Chinzorig, Tsogtbaatar; Fujiyama, Yoshito; Suzuki, Shigeru

    2014-02-01

    Troodontidae is a clade of small-bodied theropod dinosaurs. A new troodontid, Gobivenator mongoliensis gen. et sp. nov., is described based on the most complete skeleton of a Late Cretaceous member of this clade presently known, from the Campanian Djadokhta Formation in the central Gobi Desert. G. mongoliensis is different from other troodontids in possessing a pointed anterior end of the fused parietal and a fossa on the surangular in front of the posterior surangular foramen. The skull was superbly preserved in the specimen and provides detailed information of the entire configuration of the palate in Troodontidae. Overall morphology of the palate in Gobivenator resembles those of dromaeosaurids and Archaeopteryx, showing an apparent trend of elongation of the pterygoid process of the palatine and reduction of the pterygopalatine suture toward the basal Avialae. The palatal configuration suggests that the skull of Gobivenator would have been akinetic but had already acquired prerequisites for later evolution of cranial kinesis in birds, such as the loss of the epipterygoid and reduction in contact areas among bones.

  18. {sup 241}Pu concentrations in water, plankton and fish from the southern Baltic Sea

    Energy Technology Data Exchange (ETDEWEB)

    Struminska-Parulska, D.I.; Skwarzec, B. [Gdansk, Univ. (Poland). Facuty of Chemistry

    2013-08-01

    The aim of the work was to determine {sup 241}Pu activities in different components (water, plankton and fish) of the southern Baltic Sea ecosystem. Measurement of {sup 241}Pu in the samples was done indirectly by determining the increment in {sup 241}Am from the decay of the {beta}-emitting {sup 241}Pu in samples collected 10-15 years after the Chernobyl accident. Enhanced levels of {sup 241}Pu were observed in all analyzed Baltic samples. The highest {sup 241}Pu concentrations in fish were found in Perciformes: benthic round goby (0.863 {+-} 0.066 mBq/g ww) and pelagic perch (0.666 {+-} 0.001 mBq/g ww). Plutonium is also non-uniformly distributed in the organs and tissues of the analyzed fish; especially pelagic herring and cod as well as benthic flounder. Most of {sup 241}Pu in flounder, herring and cod is located in soft tissues, especially digestive organs (stomach, intestine, liver). The annual individual effective doses calculated on the basis of {sup 241}Pu concentrations in fish indicated that the impact of the consumption of {sup 241}Pu containing Baltic fish on the annual effective dose for a statistical inhabitant of Poland was very small. (orig.)

  19. Ecological conversion efficiency and its influencers in twelve species of fish in the Yellow Sea Ecosystem

    Science.gov (United States)

    Tang, Qisheng; Guo, Xuewu; Sun, Yao; Zhang, Bo

    2007-09-01

    The ecological conversion efficiencies in twelve species of fish in the Yellow Sea Ecosystem, i.e., anchovy ( Engraulis japonicus), rednose anchovy ( Thrissa kammalensis), chub mackerel ( Scomber japonicus), halfbeak ( Hyporhamphus sajori), gizzard shad ( Konosirus punctatus), sand lance ( Ammodytes personatus), red seabream ( Pagrus major), black porgy ( Acanthopagrus schlegeli), black rockfish ( Sebastes schlegeli), finespot goby ( Chaeturichthys stigmatias), tiger puffer ( Takifugu rubripes), and fat greenling ( Hexagrammos otakii), were estimated through experiments conducted either in situ or in a laboratory. The ecological conversion efficiencies were significantly different among these species. As indicated, the food conversion efficiencies and the energy conversion efficiencies varied from 12.9% to 42.1% and from 12.7% to 43.0%, respectively. Water temperature and ration level are the main factors influencing the ecological conversion efficiencies of marine fish. The higher conversion efficiency of a given species in a natural ecosystem is acquired only under the moderate environment conditions. A negative relationship between ecological conversion efficiency and trophic level among ten species was observed. Such a relationship indicates that the ecological efficiency in the upper trophic levels would increase after fishing down marine food web in the Yellow Sea ecosystem.

  20. Detrital zircon evidence for the ternary sources of the Chinese Loess Plateau

    Science.gov (United States)

    Sun, Jimin; Ding, Zhongli; Xia, Xiaoping; Sun, Min; Windley, Brian F.

    2018-04-01

    The provenance of Chinese loess is fundamental for understanding its origin, transportation and climatic significance. In this paper, eight samples were collected for detrital zircon age analysis, five from different deserts, and three from the Jingbian Section in the northern Chinese Loess Plateau, covering an age range of 2.6-0.03 Ma. The new results, integrated with knowledge of relevant topography and wind patterns, demonstrate that the age spectra of the detrital zircons in the loess are different from those of the sands from the Tarim, Junggar and Qaidam basins, implying that these basins were not the sources of the silts of the Loess Plateau. Further analysis suggests that the three sources for the loess are: (1) clastic materials eroded from the mountains of the Central Asian Orogenic Belt (especially the Gobi Altai and Hangay), (2) clastic loess-sized materials generated by erosion of the Qilian Mountains in the NE Tibetan Plateau, and (3) minor clastic debris derived from the mountains of the North China Craton. Thus, silts of the Loess Plateau have a complex origin, although inland basins, long believed to be important sources, have only a minor role at most.

  1. Characterization of the current biological communities within the Nanticoke River in the vicinity of the Vienna SES

    Energy Technology Data Exchange (ETDEWEB)

    Stroup, C.F.; Brindley, A.; Kazyak, P.F.

    1991-07-01

    Pursuant to a utility's intent to file for permission to build a generating station along the Nanticoke River, Maryland, a field program was conducted to update characterizations of major aquatic biota of the river in proximity to the existing power plant and a potential intake/discharge location. This characterization sampled five stations on the Nanticoke River, spanning 14 miles from Chapter Point to Riverton, between July 1988 and October 1989. During the study period, the juvenile and adult fish community was dominated by white perch, Atlantic menhaden, bay anchovy, hogchoker, and spot. Spring ichthyoplankton was composed of white perch, striped bass, yellow perch, and alosids, while summer ichthyoplankton was dominated by naked gobies and bay anchovy. Acartia tonsa, Eurytemora affinis and Bosmina longirostris dominated zooplankton samples. The phytoplankton community was composed primarily of diatoms, green algae, and monads. Polychaetes and crustaceans were the dominant macrobenthic taxa, with molluscs contributing to total abundance primarily during spring recruitment. The final report presents the results of fish, ichthyoplankton, zooplankton, and benthic surveys conducted between July 1988 and October 1989 in the middle portion of the Nanticoke River, Maryland. During the dry conditions of 1988, aquatic communities were dominated by estuarine species, while the lower saline environment of 1989 resulted in the presence of more freshwater species.

  2. Injury occurrence and mood states during a desert ultramarathon.

    Science.gov (United States)

    Graham, Scott M; McKinley, Mairi; Chris, Connaboy C; Westbury, Tony; Baker, Julien S; Kilgore, Lon; Florida-James, Geraint

    2012-11-01

    To describe injuries and illnesses presented and profile mood states and sleep patterns during a desert environment ultramarathon. Prospective study gathering data on mood states and injury patterns. : Gobi Desert, Mongolia. Eleven male competitors (mean mass, 83.7 ± 7.1 kg; body mass index, 24 ± 1.79 kg/m; age, 33 ± 11 years). Injuries were clinically assessed and recorded each day. Mood state was assessed using the Brunel Mood Scale. All subjects presented with abrasion injuries, dehydration, and heat stress. Vigor decreased over the first 6 days while fatigue increased (P mood alterations (P < 0.05). Increased anger and fatigue correlated strongly with sleep disruption (r = 0.736 and 0.768, respectively). Vigor and depression displayed a moderately strong correlation to sleep (r = 0.564 and -0.530). Injury patterns were similar to those reported in other adventure/ultradistance events. Consistent with previous work, data show increased fatigue and reduced vigor in response to an arduous physical challenge.

  3. Lake Michigan offshore ecosystem structure and food web changes from 1987 to 2008

    Science.gov (United States)

    Rogers, Mark W.; Bunnell, David B.; Madenjian, Charles P.; Warner, David M.

    2014-01-01

    Ecosystems undergo dynamic changes owing to species invasions, fisheries management decisions, landscape modifications, and nutrient inputs. At Lake Michigan, new invaders (e.g., dreissenid mussels (Dreissena spp.), spiny water flea (Bythotrephes longimanus), round goby (Neogobius melanostomus)) have proliferated and altered energy transfer pathways, while nutrient concentrations and stocking rates to support fisheries have changed. We developed an ecosystem model to describe food web structure in 1987 and ran simulations through 2008 to evaluate changes in biomass of functional groups, predator consumption, and effects of recently invading species. Keystone functional groups from 1987 were identified as Mysis, burbot (Lota lota), phytoplankton, alewife (Alosa pseudoharengus), nonpredatory cladocerans, and Chinook salmon (Oncorhynchus tshawytscha). Simulations predicted biomass reductions across all trophic levels and predicted biomasses fit observed trends for most functional groups. The effects of invasive species (e.g., dreissenid grazing) increased across simulation years, but were difficult to disentangle from other changes (e.g., declining offshore nutrient concentrations). In total, our model effectively represented recent changes to the Lake Michigan ecosystem and provides an ecosystem-based tool for exploring future resource management scenarios.

  4. The offshore benthic fish community

    Science.gov (United States)

    Lantry, Brian F.; Lantry, Jana R.; Weidel, Brian C.; Walsh, Maureen; Hoyle, James A.; Schaner, Teodore; Neave, Fraser B.; Keir, Michael

    2014-01-01

    Lake Ontario’s offshore benthic fish community includes primarily slimy sculpin, lake whitefish, rainbow smelt, lake trout, burbot, and sea lamprey. Of these, lake trout have been the focus of an international restoration effort for more than three decades (Elrod et al. 1995; Lantry and Lantry 2008). The deepwater sculpin and three species of deepwater ciscoes (Coregonus spp.) that were historically important in the offshore benthic zone became rare or were extirpated by the 1960s (Christie 1973; Owens et al. 2003; Lantry et al. 2007b; Roth et al. 2013). Ecosystem changes continue to influence the offshore benthic fish community, including the effects of dreissenid mussels, the near disappearance of burrowing amphipods (Diporeia spp.) (Dermott et al. 2005; Watkins et al. 2007), and the increased abundance and expanded geographic distribution of round goby (see Nearshore Fish Community chapter) (Lantry et al. 2007b). The fish-community objectives for the offshore benthic fish community, as described by Stewart et al. (1999), are:

  5. Conjugation with the Central Asian Foldbelt: Interpretation of the 3DV and Tynda-Amurzet Transects

    Science.gov (United States)

    Kheraskova, T. N.; Yakovlev, D. V.; Pimanova, N. N.; Berezner, O. S.

    2018-01-01

    In this paper we consider the results of geological interpretation of 3DV (Tommot-Skovorodino segment) and Tynda-Amurzet geophysical transects crosscutting the Aldan Shield and the Stanovoi Granite-Greenstone Domain of the Siberian Platform; the Selengino-Stanovoi, Mongolia-Okhotsk, and Gobi-Hinggang foldbelts; and the Argun and Mamyn microcontinents with a total extent of sections of about 1000 km and depth of about 40 km. The data of previous studies and follow-up electric conductivity information have been used. The data of geological mapping, subject studies, and insights into the deep-seated structure of the considered territory obtained with a complex of geophysical methods are discussed. It is shown that Mesozoic strike-slip and thrust faults play the leading role in the present-day structure of the territory and in control rifting and mantle diapirism. It is suggested that Californian-type metamorphic nuclei, which are of structure-forming significance for adjacent territories in the west, have also developed in the studied region.

  6. Mapping Palaeohydrography in Deserts: Contribution from Space-Borne Imaging Radar

    Directory of Open Access Journals (Sweden)

    Philippe Paillou

    2017-03-01

    Full Text Available Space-borne Synthetic Aperture Radar (SAR has the capability to image subsurface features down to several meters in arid regions. A first demonstration of this capability was performed in the Egyptian desert during the early eighties, thanks to the first Shuttle Imaging Radar mission. Global coverage provided by recent SARs, such as the Japanese ALOS/PALSAR sensor, allowed the mapping of vast ancient hydrographic systems in Northern Africa. We present a summary of palaeohydrography results obtained using PALSAR data over large deserts such as the Sahara and the Gobi. An ancient river system was discovered in eastern Lybia, connecting in the past the Kufrah oasis to the Mediterranean Sea, and the terminal part of the Tamanrasett river was mapped in western Mauritania, ending with a large submarine canyon. In southern Mongolia, PALSAR images combined with topography analysis allowed the mapping of the ancient Ulaan Nuur lake. We finally show the potentials of future low frequency SAR sensors by comparing L-band (1.25 GHz and P-band (435 MHz airborne SAR acquisitions over a desert site in southern Tunisia.

  7. An annotated checklist of the fishes of the Northern Territory, Australia.

    Science.gov (United States)

    Larson, Helen K; Williams, Rex S; Hammer, Michael P

    2013-01-01

    There are 1474 fish species now known from the Northern Territory, in 195 families, with a number of these species still undescribed. The 1474 species include 120 new records for the NT and three for Australia, while nine non-native species exist as small feral populations.The most speciose family is the Gobiidae (gobies), with 150 recognised species, and is the main fish group inhabiting coral reef and mangrove areas. The fish fauna of the Northern Territory occupies several biogeographical regions, which include the internal river drainages of Australia and the Sahul Shelf adjoining New Guinea and Indonesia. The Northern Territory's fish fauna most closely resembles that of north-western Western Australia, and many species are shared with this region. Among the Northern Territory's fish fauna are 55 species considered to be threatened under various listings (ASFB, EPBC), with the poor state of knowledge of the NT's fish populations and their true distributions hindering assessment. Many sampling gaps remain and the basic biology of most species is unknown.

  8. Assessment of Downscaling Planetary Boundaries to Semi-Arid Ecosystems with a Local Perception: A Case Study in the Middle Reaches of Heihe River

    Directory of Open Access Journals (Sweden)

    Heng Yi Teah

    2016-11-01

    Full Text Available The middle reaches of Heihe River are located in the oasis of the Gobi Desert where limited freshwater supply supports more than 1.5 million inhabitants. The intense agricultural activities are depleting the groundwater reserve. Consequently, natural landscapes and habitats are degraded. Though such development improves the livelihood of the local community, long-term sustainability of the ecosystem is at risk. Local authorities must be informed holistically to prepare for adapting to the changes and/or mitigating the impacts. The purpose of this study was to perform a regional sustainability assessment based on downscaling the planetary boundaries (PBs. We proposed a regional safe operating space framework that applied a top-down approach using the environmental monitoring data, and a bottom-up approach using knowledge from the local perception about environmental disaster. We conducted on-site samplings and interviews of residents to demonstrate the method. Overall, we showed that the middle reaches had transgressed the safe operating space, particularly on the freshwater use and biogeochemical flow dimensions. We found that the local perception acquired from interviews complemented the insufficiency of the monitoring data and provided the insightful social implications of transgressing the safe operating space, i.e., the anticipated impacts on local livelihood, for policy support.

  9. Singularity analysis of multisource geodatasets for information extraction and integration for mineral prospecting

    Science.gov (United States)

    Zhao, Jie

    2015-04-01

    Local singularity analysis (LSA) developed in the context of fractal and multifractals has been utilized as an efficient way to characterize non-linear geological phenomenon like flood, landslide, tectonic evolution, etc. In the past decade, this technique has been successfully applied for mineral exploration in many areas for various types of mineral deposits. Mineralization as a cascade geo-process is associated with multiple geological processes including tectono-magmatism, sedimentation, and metamorphisms which often depict non-linear properties Proper description of spatial distributions of these geological bodies can benefit mineral exploration. Current study is about identification of geological bodies in eastern Tianshan mineral district, a Gobi-desert area with thick over-burden. LSA technique was utilized to identify weak anomalies associated with mineralization from both weak and strong background. In addition to geochemical data, this study employs LSA to analyze geological and geophysical data for extracting geo-anomalies for mapping spatial distributions of felsic intrusions, intermediate-mafic volcanic strata, and faults that are associated with iron mineralization. Furthermore, these diverse geo-anomalies are integrated for delineating targets for iron mineral deposits in the covered areas.

  10. Dinosaur eggshell geochemistry as an indicator of Central Asian Cretaceous paleoenvironments

    Science.gov (United States)

    Montanari, S.; Higgins, P.; Norell, M.

    2011-12-01

    The Late Cretaceous fossiliferous beds of Mongolia's Gobi Desert have yielded spectacular articulated remains of an extraordinary diversity of fossil mammals, reptiles, birds, and dinosaurs. Paleoenvironmental interpretations of the deposits at these localities have ranged from arid wind-blown dune fields to more mesic, moist environments. Among the diversity of fossils, dinosaur eggshells are commonly found at these localities and dinosaur embryos, although rare, are also encountered. Dinosaur (including modern bird) eggs are constructed of calcite (CaCO3) allowing carbon and oxygen stable isotopes to be quantified to provide information about the environment the egg-laying animals were living in. Here we show that dinosaur eggshell from the Djadokhta Formation at one locality has not been significantly altered and reflects an environment that of dry-climate adapted C3 plants and isolated, ephemeral water sources during the egg-laying season. Carbonate nodules from the same eggshell-bearing layers also independently reflects a similar environmental signal. This study represents the first geochemical analysis of dinosaur remains from the Cretaceous of Mongolia and illustrates the potential of utilizing dinosaur eggshell geochemistry to reconstruct Mesozoic environments.Mean, n, standard deviation, and range for both carbon and oxygen isotope values for all materials sampled

  11. Aerosol contamination survey during dust storm process in Northwestern China using ground, satellite observations and atmospheric modeling data

    Science.gov (United States)

    Filonchyk, Mikalai; Yan, Haowen; Shareef, Tawheed Mohammed Elhessin; Yang, Shuwen

    2018-01-01

    The present survey addresses the comprehensive description of geographic locations, transport ways, size, and vertical aerosol distribution during four large dust events which occurred in the Northwest China. Based on the data from 35 ground-based air quality monitoring stations and the satellite data, emission flows for dust events within the period of 2014 to 2017 have been estimated. The data show that maximum peak daily average PM10 and PM2.5 concentrations exceeded 380 and 150 μg/m3, respectively, and the PM2.5/PM10 ratio was ranging within 0.12-0.66. Both satellite data and simulation data of the Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) coincide with location and extension of a dust cloud. The Cloud Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO) found dust at 0 to 10 km altitude which remained at this level during the most part of its trajectory. The vertical aerosol distribution at a wave of 532 nm total attenuated backscatter coefficient range of 0.0025-0.003 km-1 × sr-1. Moderate Resolution Imaging Spectroradiometer (MODIS) (Terra) Collection 6 Level-3 aerosol products data show that aerosol optical depth (AOD) at pollution epicenters exceeds 1. A comprehensive data survey thus demonstrated that the main sources of high aerosol pollutions in the territory were deserted areas of North and Northwest China as well as the most part of the Republic of Mongolia, where one of the largest deserts, Gobi, extends.

  12. Predation on walleye eggs by fish on reefs in western Lake Erie

    Science.gov (United States)

    Roseman, E.F.; Taylor, W.W.; Hayes, D.B.; Jones, A.L.; Francis, J.T.

    2006-01-01

    We examined diets of fishes from gillnet and egg pump collections conducted on reefs in western Lake Erie during walleye (Sander vitreus) egg incubation periods from 1994–1999 and 2004 to assess incidence of walleye eggs in fish diets. We collected no potential egg predators in samples taken in 1994 but from 1995–1999 and in 2004 we caught 22 different species of fish on reefs in addition to spawning walleye. In most years, white perch (Morone americana) stomachs contained more walleye eggs than any other species on the reefs averaging 253 eggs per stomach. We also found lower numbers of walleye eggs in the stomachs of channel catfish (Ictalurus punctatus; 53 eggs/stomach), johnny darter (Etheostoma nigrum; 2 eggs/stomach), logperch (Percina caprodes; 10 eggs/stomach), quillback (Carpiodes cyprinus; 184 eggs/stomach), rock bass (Ambloplites rupestris; 3 eggs/stomach), round goby (Neogobius melanostomus; 4 eggs/stomach), sculpin (Cottidae; 21 eggs/stomach), silver chub (Macrhybopsis storeriana; 3 eggs/stomach), spottail shiner (Notropis hudsonius; 14 eggs/stomach), trout-perch (Percopsis omiscomaycus; 30 eggs/stomach), white sucker (Catastomus commersonii; 20 eggs/stomach), and yellow perch (Perca flavescens; 181 eggs/stomach). Similar to other studies of predation on walleye eggs, our results indicate that prolonged incubation periods increase the potential for egg loss due to predation.

  13. The Meteoritical Bulletin, No. 80, 1996 July

    Science.gov (United States)

    Grossman, Jeffrey N.

    1996-07-01

    The Meteoritical Bulletin No. 80 lists data for 178 meteorites. Noteworthy are 3 HED meteorites (ALH 88102, Hammadah al Hamra (HaH) 059, and Monticello); 3 ureilites (HaH 064, HaH 126, and Dar al Gani (DaG) 084); 4 irons (Baygorria (IAB), Ste. Croix (IIIAB), Sargiin Gobi (IAB), and Tarahumara (IIE)); an unusual metal-rich meteorite (Vermillion); 8 carbonaceous chondrites (HaH 043 (C03), HaH 073 (C4), DaG 055 (C3) and 5 C03 chondrites (probably paired) from DaG); an R chondrite (DaG 013); and 6 unequilibrated ordinary chondrites (ALH 88105 (L3), Camel Donga 016 (L3), HaH 093 (LL3.9), HaH 096 (LL(L)3), Richfield (LL3.7), and Sarir Quattusah (LL(L)3)). Three recent falls of ordinary chondrites (Coleman (LL5), St. Robert (H5), and Tsukuba (H5-6)) are described.

  14. An analysis of the correlation between dust storms in Korea and 137Cs nuclide concentration

    International Nuclear Information System (INIS)

    Choi, Soo-won; Kim, Jeong-hun; Shin, Sang-hwa; Hwang, Joo-ho

    2008-01-01

    Dust storms occur in Korea during spring time when fine dust is blown in from the far western regions of western China and Mongolia. A fine powdery dust is blown up into the sky and enters the upper reaches of the atmosphere where it is carried easterly across China then slowly falls to the ground on the Korean peninsula and Japan. The dust originates mostly in the Gobi dessert of China, as well as the yellow earth regions in the middle and upper streams of the Yellow river in China. Previous studies on dust storms have been limited to following or estimating their courses, distribution and frequency, or distribution of the heavy metals they transmit. However, since radionuclides exist in the dust, they must also exist in the dust storms. In this study, we analyzed the correlation of :1 37 Cs nuclide concentration based on a count of annual dust storm occurrence in the city of Suwon, South Korea and assessed seasonal differences of 137 Cs nuclide concentration

  15. Provenance of Chinese Loess: Evidence from Stable Lead Isotope

    Directory of Open Access Journals (Sweden)

    Feng Wu

    2011-01-01

    Full Text Available Twenty-seven samples of typical loess and paleosol strata collected in nine different regions of the Chinese Loess Plateau (CLP were fractionated into PM1.0, PM2.5, PM10 and Total Suspended Particulates (TSP (particulate matter with aerodynamic diameters less than 1.0, 2.5, 10 and ~30 £gm, respectively by a resuspension chamber at the Desert Research Institute (DRI; Reno, NV, United States. The amounts and isotope ratios of lead (Pb were quantified in the loess samples. Our size-segregated analysis demonstrated that the Pb isotopic composition in the loess-paleosol deposits was preserved after grain-size sorting and that therefore the isotope ratio can serve as a proxy for source tracing. A similar pattern of Pb isotope ratios was observed for sediment collected from potential source regions and the loess samples suggested that the Gobi and deserts in southern Mongolia and northern China are major sources for the deposits in the CLP. No significant deviation of Pb isotope amount was found between the nine samples of loess and paleosol strata, implying the stability of loess sources during the glacial and interglacial regime.

  16. Model Study on the Transport and Mixing of Dust Aerosols and Pollutants during an Asian Dust Storm in March 2002

    Directory of Open Access Journals (Sweden)

    Xiujuan Zhao

    2007-01-01

    Full Text Available The transport and mixing of dust aerosols and pollutants in East Asia during March 18 to 22, 2002 was studied using the nested air quality prediction model system (NAQPMS. Dust was primarily generated in the Gobi desert on 19 March and then swept across several areas of East Asia. The model results were verified with observations of surface weather, TSP/PM10, SO2 and lidar data. The model simulated the right timing and strength of dust events, capturing most of the variation features in dust and SO2. Numerical results showed that the dust aerosols were mainly transported in two layers and mixed with pollutants in different ways. Some of the dust kicked up in the source region was uplifted to a higher layer (200 - 2000 m layer and transported downwind faster than dust of the lower level. This lower-level dust was of greater concentration. The dust arriving at the upper layer began to drop and mixed well with pollutants in the atmosphere during ¡§the first period¡¨. During ¡§the second period¡¨, pollutants were diluted by the dust air mass that was transported along the lower layer. The remaining pollutants mixed well with dust aerosols during this period. The mixed air mass of the higher layer (1500 m eventually reached the Northwestern Pacific. A large amount of clouds in the upper layers potentially led to an increase in sulfate mass on the surface of dust particles.

  17. Model Study on the Transport and Mixing of Dust Aerosols and Pollutants during an Asian Dust Storm in March 2002

    Directory of Open Access Journals (Sweden)

    Xiujuan Zhao

    2007-01-01

    Full Text Available The transport and mixing of dust aerosols and pollutants in East Asia during March 18 to 22, 2002 was studied using the nested air quality prediction model system (NAQPMS. Dust was primarily generated in the Gobi desert on 19 March and then swept across several areas of East Asia. The model results were verified with observations of surface weather, TSP/PM10, SO2 and lidar data. The model simulated the right timing and strength of dust events, capturing most of the variation features in dust and SO2. Numerical results showed that the dust aerosols were mainly transported in two layers and mixed with pollutants in different ways. Some of the dust kicked up in the source region was uplifted to a higher layer (200 - 2000 m layer and transported downwind faster than dust of the lower level. This lower-level dust was of greater concentration. The dust arriving at the upper layer began to drop and mixed well with pollutants in the atmosphere during _ first _ During _ second _ pollutants were diluted by the dust air mass that was transported along the lower layer. The remaining pollutants mixed well with dust aerosols during this period. The mixed air mass of the higher layer (1500 m eventually reached the Northwestern Pacific. A large amount of clouds in the upper layers potentially led to an increase in sulfate mass on the surface of dust particles.

  18. Development of standard weight equations for Caribbean and Gulf of Mexico amphidromous fishes

    Science.gov (United States)

    Cooney, Patrick B.; Kwak, Thomas J.

    2010-01-01

    We collected and compiled length and weight information from four countries and one commonwealth to develop standard weight (Ws) equations for three amphidromous fish species native to the Caribbean and Gulf of Mexico regions: mountain mullet Agonostomus monticola (N = 9,768 individuals, 52 populations), river goby Awaous banana (N = 1,847 individuals, 62 populations), and bigmouth sleeper Gobiomorus dormitor (N = 2,983 individuals, 53 populations). Linear and quadratic Ws equations for three quartiles (25%, median, 75%) are presented for these three species. The length-weight relationship from eight lentic bigmouth sleeper populations was significantly different from that of lotic populations, reflecting higher weights of juvenile fish (equations were developed for lotic populations of bigmouth sleepers. W(s) equations were not developed from lentic bigmouth sleeper populations alone due to the low number of applicable populations caused by life history constraints; the equation from combined lentic and lotic populations is suggested for application to lentic bigmouth sleeper populations. These morphometric relationships for amphidromous fishes may improve the ability to assess existing and potential sport fisheries and allow ecological assessment based on fish condition.

  19. Alonzo Pond and the 1930 Logan Museum Expedition to North Africa - The Beloit College Symposium, edited by L. B. Breitborde, Logan Museum Bulletin (new series, vol. 1, no. 1, 1992

    Directory of Open Access Journals (Sweden)

    Andrew L. Christenson

    1994-11-01

    Full Text Available After a 32 year hiatus, the Logan Museum Bulletin returns with a number on the man who contributed to three of the first five numbers of the old series, Alonzo W. Pond. Pond is one of those archaeologists with a distinctive name most professionals recognize, but whose specific accom­plishments do not easily come to mind. For lithic analysts, his work on flintknapper Halvor Skavlem stands foremost (pond 1930, but for desert enthusiasts his work with Roy Chapman Andrews in the Gobi, the Rainbow Bridge-Monument Valley Expedition in the American South­ west, and Beloit College in the Sahara are most memorable. The last season of the latter expedi­tion is the focus of this slim volume, based upon a symposium given in 1985. The six chapters in the volume stand alone without an editorial structure and 50 readers are on their own to synthesize the information provided. Unfortunately, the longest contribution, Kit Hinsley's revision of a previously published (Hinsley 1989 visual analysis of late 19th century archaeological images, although of interest in the grand scale of things, sticks out as being unrelated to the concern of the volume. The author or editor should have done something to make this unrelatedness less obvious.

  20. Aeolian processes over gravel beds: Field wind tunnel simulation and its application atop the Mogao Grottoes, China

    Science.gov (United States)

    Zhang, Weimin; Tan, Lihai; Zhang, Guobin; Qiu, Fei; Zhan, Hongtao

    2014-12-01

    The aeolian processes of erosion, transport and deposition are threatening the Mogao Grottoes, a world culture heritage site. A field wind tunnel experiment was conducted atop the Mogao Grottoes using weighing sensors to quantify aeolian processes over protective gravel beds. Results reveal that aeolian erosion and deposition over gravel beds are basically influenced by gravel coverage and wind speed. Erosion is a main aeolian process over gravel beds and its strength level is mainly determined by gravel coverage: strong (50%). Aeolian deposition only occurs when gravel coverage is equal to or greater than 30% and wind speeds are between 8 and 12 m s-1, and this process continues until the occurrence of the equilibrium coverage. In addition, the change in conditions of external sand supply affects the transition between aeolian deposition and erosion over gravel beds, and the quantity of sand transport at the height of 0-24 mm is an important indicator of aeolian deposition and erosion over gravel beds. Our results also demonstrate that making the best use of wind regime atop the Mogao Grottoes and constructing an artificial gobi surface in staggered arrays, with 30% coverage and 30-mm-high gravels and in 40 mm spacing can trap westerly invading sand flow and enable the stronger easterly wind to return the deposited sand on the gravel surface back to the Mingsha Mountain so as to minimize the damage of the blown sand flux to the Mogao Grottoes.