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Sample records for cultured freshwater fish

  1. Recent developments in the application of live feeds in the freshwater ornamental fish culture

    OpenAIRE

    L C Lim; Dhert, P.; Sorgeloos, P

    2003-01-01

    The industrial development of freshwater ornamental fish culture has been hampered by the lack of suitable live feeds for feeding the fish at the various production stages. This paper reports the recent developments in the applications of the freshwater rotifers (Brachionus calyciflorus), Artemia nauplii, decapsulated Artemia cysts and on-grown Artemia in the freshwater ornamental fish culture. Results demonstrate that the rotifers are an ideal starter feed for dwarf gourami (Colisa lalia), a...

  2. A multi-indicator framework for mapping cultural ecosystem services: The case of freshwater recreational fishing

    Science.gov (United States)

    Villamagna, Amy M.; Mogollon, Beatriz; Angermeier, Paul

    2014-01-01

    Despite recent interest, ecosystem services are not yet fully incorporated into private and public decisions about natural resource management. Cultural ecosystem services (CES) are among the most challenging of services to include because they comprise complex ecological and social properties and processes that make them difficult to measure, map or monetize. Like others, CES are vulnerable to landscape changes and unsustainable use. To date, the sustainability of services has not been adequately addressed and few studies have considered measures of service capacity and demand simultaneously. To facilitate sustainability assessments and management of CES, our study objectives were to (1) develop a spatially explicit framework for mapping the capacity of ecosystems to provide freshwater recreational fishing, an important cultural service, (2) map societal demand for freshwater recreational fishing based on license data and identify areas of potential overuse, and (3) demonstrate how maps of relative capacity and relative demand could be interfaced to estimate sustainability of a CES. We mapped freshwater recreational fishing capacity at the 12-digit hydrologic unit-scale in North Carolina and Virginia using a multi-indicator service framework incorporating biophysical and social landscape metrics and mapped demand based on fishing license data. Mapping of capacity revealed a gradual decrease in capacity eastward from the mountains to the coastal plain and that fishing demand was greatest in urban areas. When comparing standardized relative measures of capacity and demand for freshwater recreational fishing, we found that ranks of capacity exceeded ranks of demand in most hydrologic units, except in 17% of North Carolina and 5% of Virginia. Our GIS-based approach to view freshwater recreational fishing through an ecosystem service lens will enable scientists and managers to examine (1) biophysical and social factors that foster or diminish cultural ecosystem

  3. Occurrence of monogeneans on freshwater fishes in Iran: Dactylogyrus spp. on cultured Iranian fishes.

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    Jalali, B; Molnár, K

    1990-01-01

    Thirteen Dactylogyrus spp. were found on cultured fishes in five Iranian fish farms. Besides typical Dactylogyrus vastator, specimens with small anchors were often found in goldfish, which were designated as D. vastator forma minor. Rutilus frisii kutum, a fish cultured only in Iran, was infected by two Dactylogyrus spp. during its short period of prerearing in Iranian fish farms. All Dactylogyrus found are new for the Iranian fauna.

  4. Diversity and distribution of parasites from potentially cultured freshwater fish in Nakhon Si Thammarat

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    Supamattaya, K.

    2005-02-01

    Full Text Available Twenty-one species from 16 genera of potentially cultured freshwater fish were examined for external and internal parasites. Ten individuals of each fish species were sampled from various places in Nakhon Si Thammarat. Eight groups, 72 species were identified and the majority was external (52 spp.. The parasites found were ciliated protozoan (2 spp., myxozoan (2 spp., monogenean (44 spp., digenean (7 spp., cestode (6 spp., nematode (6 spp., acanthocephalan (2 spp. and crustacean (3 spp.. Monogenean was regarded as a major group of parasites with 44 species. Dactylogyrus (Monogenea had the highest number of species (12 spp., whereas Trichodina pediculus (Ciliophora was the most widely distributed species observed from at least 7 fish species (7 families. Most of the parasites (72 % found in this study were specific to their host species.

  5. Freshwater and fish

    Energy Technology Data Exchange (ETDEWEB)

    Saxen, R. [Finnish Centre for Radiation and Nuclear Safety (Finland)

    1997-10-01

    Severe radioactive contamination of the freshwater environment could have serious consequences for both drinking water and fish. Most of the Nordic countries have an abundance of freshwater lakes and rivers. Finland alone has about 56,000 lakes, each with a surface area of 1 hectare or more. Nearly 10% of Finland`s surface is covered with lakes and rivers. In Sweden, about 9% of the surface area is freshwater, in Norway about 5%, and in Denmark only about 2%. Freshwater plays a minor role in Iceland, but even there numerous rivers discharge from the volcanic soils to the Ocean. Cs-137 and {sup 90}Sr are likely to be the most important radionuclides with respect to long term radioactive contamination of freshwater. If radioactive deposition occurs in the absence of snow and ice radionuclides will contaminate the surface water directly and may rapidly enter the aquatic food chain. Fish which eat contaminated plankton become contaminated almost immediately. Deposition during summer increases the transfer for radionuclides to fish since fish metabolism is faster during the warm season. During the cold period, fish metabolism is slow and thus uptake and excretion of radiocaesium are also slow. (EG). 18 refs.

  6. Folkbiology of Freshwater Fish

    Science.gov (United States)

    Medin, Douglas L.; Ross, Norbert O.; Atran, Scott; Cox, Douglas; Coley, John; Proffitt, Julia B.; Blok, Sergey

    2006-01-01

    Cross-cultural comparisons of categorization often confound cultural factors with expertise. This paper reports four experiments on the conceptual behavior of Native American and majority-culture fish experts. The two groups live in the same general area and engage in essentially the same set of fishing-related behaviors. Nonetheless, cultural…

  7. Comparison of lipid content and Fatty Acid composition in the edible meat of wild and cultured freshwater and marine fish and shrimps from china.

    Science.gov (United States)

    Li, Guipu; Sinclair, Andrew J; Li, Duo

    2011-03-09

    The lipid content and fatty acid composition in the edible meat of twenty-nine species of wild and cultured freshwater and marine fish and shrimps were investigated. Both the lipid content and fatty acid composition of the species were specified due to their unique food habits and trophic levels. Most of the marine fish demonstrated higher lipid content than the freshwater fish, whereas shrimps had the lowest lipid content. All the marine fish and shrimps had much higher total n-3 PUFA than n-6 PUFA, while most of the freshwater fish and shrimps demonstrated much lower total n-3 PUFA than n-6 PUFA. This may be the biggest difference in fatty acid composition between marine and freshwater species. The cultured freshwater fish demonstrated higher percentages of total PUFA, total n-3 PUFA, and EPA + DHA than the wild freshwater fish. Two freshwater fish, including bighead carp and silver carp, are comparable to the marine fish as sources of n-3 PUFA.

  8. Input pathways of organochlorine pesticides to typical freshwater cultured fish ponds of South China: hints for pollution control.

    Science.gov (United States)

    Zhang, Bao-Zhong; Yu, Huan-Yun; You, Jing; Zeng, Eddy Y

    2011-06-01

    Air, rain, pond water, bank soil, pond sediment, fish feed, and fish were sampled from four freshwater cultured fish ponds (FWCFPs) in rural areas within the Pearl River Delta (PRD) of South China. Compositional analyses indicated that historical residues were the main sources of DDXs (defined as the sum of dichlorodiphenyltrichloroethane (DDT), dichlorodiphenyldichloroethane (DDD), and dichlorodiphenyldichloroethylene (DDE) and 1-chloro-2,2-bis(4-chlorophenyl)ethane (p,p'-DDMU)), and hexachlorocyclohexanes (HCHs) in the FWCFPs. The input fluxes to the FWCFPs were estimated at 4.0, 1.6, 15, and -0.92 µg/m(2) ·year for DDXs and 3.8, 0.92, 2.9, and -1.4 µg/m(2) ·year for HCHs for dry deposition, wet deposition, feeding, and net air-water exchange in Dongguan, and 3.8, 1.2, 137, and -1.2 µg/m(2) ·year for DDXs and 3.6, 0.66, 5.0, and -1.0 µg/m(2) ·year for HCHs in Shunde, respectively. These results indicated that fish feed was the dominant input source of DDXs to the FWCFPs. As for HCHs, fluxes via dry deposition and feeding were similar and slightly higher than those via wet deposition. Biological effects due to the occurrence of DDXs in the FWCFPs were minimal, and consumption of freshwater fish from the PRD appeared to pose insignificant risk to human health based on some existing regulations and guidelines. Copyright © 2011 SETAC.

  9. Rickettsia-like organism infection in a freshwater cultured fish Ophiocephalus argus C.in China

    Institute of Scientific and Technical Information of China (English)

    GUO Qionglin; JIA Weizhang; HAN Xianpu; CAI Taozhen; GONG Xiaoning; SUN Xiaofeng

    2004-01-01

    From 2001 to 2002,a new and emergent infectious disease of Ophiocephalus argus occurred in a fishery in Hubei Province,China,with an incidence of 60%~70% and a mortality as high as 100%.The diseased fish showed an enlarged abdomen,the millet-like nodules in internal organs,and the swollen kidney which was composed of 5~10 sarcoma-like bodies in cream or gray-white colour or ulcerated into beandregs-like substance.Light microscopic observation revealed the basophilic or acidphilic inclusions in cytoplasm of the cells and the granulomas,a diffusive chronic inflammation in internal organs.Further analysis under an electron microscope indicated that the intracytoplasmic inclusions were rickettsia-like organisms (RLOs) that are either spherical or coccoid,with variable size,ranging from 0.5~1.5 μm in diameter,and enclosed within membrane-bound cytoplasmic vacuoles.RLO had a central nucleoid region with some fine filamentous structures and an electron-dense granule.Its cytoplasm contained abundant ribosomal bodies.Occasionally,RLO appeared to be divided by binary fission.RLOs were also observed in the homogenized tissue of infected fish.The results suggested that the death of cultured O.Argus was caused by RLO infection.

  10. Native Freshwater Fish and Mussel Species Richness

    Data.gov (United States)

    U.S. Environmental Protection Agency — These data represent predicted current distributions of all native freshwater fish and freshwater mussels in the Middle-Atlantic region. The data are available for...

  11. Effects of Pollution on Freshwater Fish.

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    Brungs, W. A.; And Others

    1978-01-01

    Presents a literature review of the effects of pollution on freshwater fish, covering publications of 1976-77. This review includes: (1) water quality; (2) pesticide pollutants; (3) chemical pollutants; (4) miscellaneous pollutants; and (5) physical factors of pollution on freshwater fish. A list of 338 references is also presented. (HM)

  12. The Fresh-water Fishes of Singapore

    NARCIS (Netherlands)

    Alfred, E.R.

    1966-01-01

    CONTENTS Page Introduction 5 Materials................... 6 The environment................. 7 Ichthyological literature of Singapore........... 9 Aquarium fishes................. io Pond culture fishes................ n Introduced species................. 12 Acknowledgements................ 13 Syst

  13. Freshwater fishes of Tsitsikamma National Park

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    I.A. Russell

    2002-12-01

    Full Text Available This study aimed to determine the distribution and relative abundance of freshwater fishes in the Tsitsikamma National Park. Fish assemblages in six river systems were sampled in 2001, with a total of 323 fish from eight species recorded. Indigenous fish collected included four freshwater species (Pseudobarbus afer, Pseudobarbus tenuis, Sandelia capensis, Anguilla mossambica, three estuarine species (Monodactylus falciformis, Caffrogobius gilchristi, Myxus capensis, and one alien (Micropterus salmoides. One additional indigenous species (Galaxias zebratus and two aliens (Salmo trutta, Oncorhynchus mykiss could potentially occur within the park. The topography and locality of the park presents a unique opportunity to meaningfully conserve the endangered P. tenuis as well as other fish characteristic of the eastern reaches of the Cape Floristic Region. Management action is required to minimise opportunities for further establishment and spread of alien fish species and to conserve indigenous fish assemblages within the park.

  14. Opisthorchis viverrini metacercaria in Thai freshwater fish.

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    Waikagul, J

    1998-06-01

    Examination for metacercaria in freshwater fish, the common intermediate hosts of Opisthorchis viverrini was carried out during 1992-1996. The 4-year survey of fish from markets in 14 provinces revealed that metacercariae of O. viverrini were found in fish from Udon Thani, Sa Kaeo and Prachin Buri Provinces; fish from Aranyaprathet district had the highest positive rates (25-28%). Fish from 12 provinces were found to be positive with heterophyid metacercariae, namely: Haplorchis pumilio, H. taichui, H. yokogawai, Stellantchasmus falcatus, Centrocestus formosanus and Haplorchoides cahirinus. It was also observed that the prevalence of O. viverrini metacercaria in fish decreased markedly during the last 10 years.

  15. Freshwater fish of the Wilderness National Park

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    I.A. Russell

    1999-01-01

    Full Text Available The study aimed to determine the distribution and relative abundance of freshwater fish in the Wilderness National Park. Fish assemblages in the Touw and Duiwe rivers were sampled in 1997 and 1998, with a total of 327 fish from nine species recorded. Indigenous species included two freshwater species (Pseudobarbus afer, Sandelia capensis, two catadromous species (Anguilla mossambicus, Myxus capensis, and two estuarine species (Monodactylusfalciformis, Caffrogobius multifasciatus. Three of the nine recorded species were alien (Micropterus dolomieu, Micropterus salmoides, Gambusia affinis, with the Micropterus spp., in particular, likely to have a substantial negative influence on indigenous species. A further one indigenous species, two translocated indigenous species, and five estuarine species could potentially be recorded in these rivers. River catchment management actions to restore perennial flow to the Duiwe River, to prevent the attenuation of floods, and to prevent further establishment and spread of alien and translocated biota are required to conserve indigenous fish assemblages.

  16. Freshwater fishes of Bontebok National Park

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    I.A. Russell

    2001-08-01

    Full Text Available Fish assemblages were sampled at six sites in the Breede River in the Bontebok National Park during 1999 and 2000. A total of 380 fish from 12 species was recorded. Indigenous fish collected included one freshwater species (Barbus andrewi, two catodromous species (Anguilla mossambica, Myxus capensis. and three estuarine species (Gilchris- tella aestuaria, Monodactylusfalciformis, Mugil cephalus. Four of the species recorded were aliens (Tinea tinea, Lepomis macrochirus, Micropterus salmoides, Micropterus dolomieu and two species translocated from other South African rivers (Tilapia sparrmanii, Clarias gariepinus. A further two indigenous species (Sandelia capensis, Pseudobarbus biirchelli could potentially occur within the park, though the high abundance of alien predators means that there is little chance for recolonisation from tributaries higher in the Breede River system. There is little opportunity to meaningfully conserve most indigenous freshwater fish in Bontebok National Park.

  17. First case of Aeromonas schubertii infection in the freshwater cultured snakehead fish, Ophiocephalus argus (Cantor), in China.

    Science.gov (United States)

    Liu, J Y; Li, A H

    2012-05-01

    An epizootic in snakehead fish, Ophiocephalus argus, in earthen ponds in Xianning, Hubei Province, central China, from June to August 2009 was found to be caused by Aeromonas schubertii. The cumulative mortality within 40 days was 45%, and the diseased fish were 18 months old and 35-45 cm in length. Multiple, ivory-white, firm nodules, 0.5-1 mm in diameter, were scattered throughout the kidney. Blood clots, 3-5 mm in diameter, were found in the liver. This is a disease frequently found in cultured snakehead throughout China. Isolated bacteria were Gram negative, facultatively anaerobic, motile, short rod-shaped, with a length of 0.3-1.0 μm. Morphological and biochemical tests, as well as phylogenetic analysis derived from 16S rRNA, gyrB, rpoD and dnaJ gene sequencing all strongly indicated that these snakehead isolates are identical to A. schubertii. In addition, the isolates possessed two plasmids: 5.0 kb and 10.0 kb. Antibiotic sensitivity testing of the isolates was carried out by the standard Kirby-Bauer disc diffusion method. Experimental infection assays were conducted, and pathogenicity (by intraperitoneal injection) was demonstrated in snakehead fingerlings and zebrafish, Brachydanio rerio (Hamilton).

  18. Fish and mussels: importance of fish for freshwater mussel conservation

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    Ronaldo Sousa

    2015-12-01

    Full Text Available Co-extinctions have received trivial consideration in discussions about the global conservation crisis, even though recent studies have emphasised their importance. This situation is even more pronounced in freshwater ecosystems where this phenomenon is largely unrecognized. In this presentation we explore the role of fish for freshwater mussels’ conservation. Freshwater mussels’ need fish as a host to complete their life cycle and given this premise is expected that changes in the fish community due to species extinctions or additions may have great effects. We reviewed the published information and we found: 1 that most of the studies were published in the last few years; 2 that most of the studies were performed in North America (69%, which is probably due to the high number of endemic threatened species in this continent; 3 that most of the mussel species that are specialists in fish hosting are listed as vulnerable or endangered (55%; 4 most studies were performed in laboratory (83% and 5 that the majority of studies were focused on life cycle or on identifying suitable fish hosts of freshwater mussel species with few studies focusing on threats. Since the interaction between fish and freshwater mussels can be easily disrupted and serious threats to this interaction have arisen (e.g. loss and fragmentation of habitat, changes in river flow, climate change, introduction of invasive species, pollution a more holistic approach is needed to find the best management strategies to conserve these animals. In addition, more field studies are required and more information on African, South American and Asian species is essential. Neglect the possible fundamental role of fish in the decline or extinction of freshwater mussels may impair the success of any measure devoted to their conservation; therefore, this issue cannot be ignored.

  19. Why are freshwater fish so threatened?

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    Closs, Gerard P.; Angermeier, Paul; Darwall, William R.T.; Balcombe, Stephen R.

    2015-01-01

    The huge diversity of freshwater fishes is concentrated into an area of habitat that covers only about 1% of the Earth's surface, and much of this limited area has already been extensively impacted and intensively managed to meet human needs (Dudgeon et al., 2006). As outlined in Chapter 1, the number and proportions of threatened species tend to rise wherever fish diversity coincides with dense human populations, intensive resource use and development pressure. Of particular concern is the substantial proportion of the global diversity of freshwater fishes concentrated within the Mekong and Amazon Basins and west-central Africa (Berra, 2001; Abell et al., 2008; Dudgeon, 2011; Chapter 1) with extensive exploitation of water resources planned to accelerate in future years (Dudgeon, 2011; Chapter 1). If current trends continue, and the social, political and economic models that have been used to develop industrialised regions of the world over the past two centuries prevail, then the future of a significant proportion of global diversity of freshwater fish species is clearly uncertain.

  20. Threatened and Endangered Freshwater Fish and Mussel Species Richness

    Data.gov (United States)

    U.S. Environmental Protection Agency — These data represent predicted current distributions of all US listed Threatened and Endangered freshwater fish and freshwater mussels in the Middle-Atlantic region....

  1. Identifying Canadian freshwater fishes through DNA barcodes.

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    Nicolas Hubert

    Full Text Available BACKGROUND: DNA barcoding aims to provide an efficient method for species-level identifications using an array of species specific molecular tags derived from the 5' region of the mitochondrial cytochrome c oxidase I (COI gene. The efficiency of the method hinges on the degree of sequence divergence among species and species-level identifications are relatively straightforward when the average genetic distance among individuals within a species does not exceed the average genetic distance between sister species. Fishes constitute a highly diverse group of vertebrates that exhibit deep phenotypic changes during development. In this context, the identification of fish species is challenging and DNA barcoding provide new perspectives in ecology and systematics of fishes. Here we examined the degree to which DNA barcoding discriminate freshwater fish species from the well-known Canadian fauna, which currently encompasses nearly 200 species, some which are of high economic value like salmons and sturgeons. METHODOLOGY/PRINCIPAL FINDINGS: We bi-directionally sequenced the standard 652 bp "barcode" region of COI for 1360 individuals belonging to 190 of the 203 Canadian freshwater fish species (95%. Most species were represented by multiple individuals (7.6 on average, the majority of which were retained as voucher specimens. The average genetic distance was 27 fold higher between species than within species, as K2P distance estimates averaged 8.3% among congeners and only 0.3% among concpecifics. However, shared polymorphism between sister-species was detected in 15 species (8% of the cases. The distribution of K2P distance between individuals and species overlapped and identifications were only possible to species group using DNA barcodes in these cases. Conversely, deep hidden genetic divergence was revealed within two species, suggesting the presence of cryptic species. CONCLUSIONS/SIGNIFICANCE: The present study evidenced that freshwater fish

  2. Freshwater temperature in the state of Rio Grande do Sul, Southern Brazil, and its implication for fish culture

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    Luciano de Oliveira Garcia

    Full Text Available In this study we verified data of water temperatures collected by CORSAN-RS from 1996 to 2004 in several cities of the state of Rio Grande do Sul, southern Brazil, and analyzed the possibility of raising the most cultivated fish species in Brazil. The water temperature from 1996 to 2004 was 16 to 28ºC in summer, 17 to 23ºC in fall, 14 to 17ºC (down to 9ºC in the coldest months in winter and 14 to 21ºC in spring. Native species of this state, such as silver catfish (Rhamdia quelen, traíra (Hoplias malabaricus, dorado (Salminus brasiliensis, pintado (Pimelodus maculatus, as well as carps (family Cyprinidae, are resistant to the low winter temperatures. These species have a lower growth rate in coldest months (winter/spring but a good development in warmer months (summer/fall, reaching a satisfactory performance throughout the year. In the periods of more intense cold, mortality of some introduced species, such as surubim from Amazon Basin (Pseudoplatystoma sp., pirapitinga (Piaractus brachypomus, pirarucu (Arapaimas gigas, pacu (Piaractus mesopotamicus, tambaqui (Colossoma macropomum and Nile tilapia (Oreochromis niloticus may occur. In addition, as most tropical species have a thermal range for growth and reproduction between 20 to 28ºC, some species may have poor development even in fall. Therefore, water temperature in this state should be considered in the choice of fish species to be cultivated.

  3. Current status of parasitic ciliates Chilodonella spp. (Phyllopharyngea: Chilodonellidae) in freshwater fish aquaculture.

    Science.gov (United States)

    Bastos Gomes, G; Jerry, D R; Miller, T L; Hutson, K S

    2016-07-30

    Freshwater fish farming contributes to more than two-thirds of global aquaculture production. Parasitic ciliates are one of the largest causes of production loss in freshwater farmed fishes, with species from the genus Chilodonella being particularly problematic. While Chilodonella spp. include 'free-living' fauna, some species are involved in mortality events of fish, particularly in high-density aquaculture. Indeed, chilodonellosis causes major productivity losses in over 16 species of farmed freshwater fishes in more than 14 countries. Traditionally, Chilodonella species are identified based on morphological features; however, the genus comprises yet uncharacterized cryptic species, which indicates the necessity for molecular diagnostic methods. This review synthesizes current knowledge on the biology, ecology and geographic distribution of harmful Chilodonella spp. and examines pathological signs, diagnostic methods and treatments. Recent advances in molecular diagnostics and the ability to culture Chilodonella spp. in vitro will enable the development of preventative management practices and sustained freshwater fish aquaculture production.

  4. Ecological speciation in marine v. freshwater fishes.

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    Puebla, O

    2009-10-01

    Absolute barriers to dispersal are not common in marine systems, and the prevalence of planktonic larvae in marine taxa provides potential for gene flow across large geographic distances. These observations raise the fundamental question in marine evolutionary biology as to whether geographic and oceanographic barriers alone can account for the high levels of species diversity observed in marine environments such as coral reefs, or whether marine speciation also operates in the presence of gene flow between diverging populations. In this respect, the ecological hypothesis of speciation, in which reproductive isolation results from divergent or disruptive natural selection, is of particular interest because it may operate in the presence of gene flow. Although important insights into the process of ecological speciation in aquatic environments have been provided by the study of freshwater fishes, comparatively little is known about the possibility of ecological speciation in marine teleosts. In this study, the evidence consistent with different aspects of the ecological hypothesis of speciation is evaluated in marine fishes. Molecular approaches have played a critical role in the development of speciation hypotheses in marine fishes, with a role of ecology suggested by the occurrence of sister clades separated by ecological factors, rapid cladogenesis or the persistence of genetically and ecologically differentiated species in the presence of gene flow. Yet, ecological speciation research in marine fishes is still largely at an exploratory stage. Cases where the major ingredients of ecological speciation, namely a source of natural divergent or disruptive selection, a mechanism of reproductive isolation and a link between the two have been explicitly documented are few. Even in these cases, specific predictions of the ecological hypothesis of speciation remain largely untested. Recent developments in the study of freshwater fishes illustrate the potential for

  5. Arsenic speciation patterns in freshwater fish.

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    Slejkovec, Zdenka; Bajc, Zlatka; Doganoc, Darinka Z

    2004-04-19

    Muscle of 16 freshwater fish (9 different species belonging to 4 different families) was analysed for arsenic species using HPLC separation (anion and cation exchange) followed by on-line UV-decomposition, hydride generation and AFS detection. The main arsenic compounds found in the extracts were arsenobetaine (AsB), which accounted for 92-100% of extractable arsenic in species of salmonids (Salmo marmoratus, Oncorhynchus mykiss, Salmo trutta m. fario), and dimethylarsinic acid (DMAA), which accounted for 75% of extractable arsenic in burbot (Lota lota). AsB was also found in lower concentrations in almost all other fish species analysed (Silurus glanis, L. lota, Barbus barbus, Rutilus pigus virgo, Chondrostoma nasus). Arsenite (As(III)) and trimethylarsine oxide (TMAO) were detected in low concentrations in some representatives of Cyprinidae only (R. pigus virgo, C. nasus). Except in salmonids, an unknown cationic compound was present in most of the samples in relatively low concentrations. Cluster analysis of the generated data seems to indicate that there is a correlation between fish family and the arsenic speciation pattern. This is especially clear for the salmonids which show a completely separate cluster and thus a very distinct arsenic speciation pattern.

  6. Climate and local abundance in freshwater fishes.

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    Knouft, Jason H; Anthony, Melissa M

    2016-06-01

    Identifying factors regulating variation in numbers of individuals among populations across a species' distribution is a fundamental goal in ecology. A common prediction, often referred to as the abundant-centre hypothesis, suggests that abundance is highest near the centre of a species' range. However, because of the primary focus on the geographical position of a population, this framework provides little insight into the environmental factors regulating local abundance. While range-wide variation in population abundance associated with environmental conditions has been investigated in terrestrial species, the relationship between climate and local abundance in freshwater taxa across species' distributions is not well understood. We used GIS-based temperature and precipitation data to determine the relationships between climatic conditions and range-wide variation in local abundance for 19 species of North American freshwater fishes. Climate predicted a portion of the variation in local abundance among populations for 18 species. In addition, the relationship between climatic conditions and local abundance varied among species, which is expected as lineages partition the environment across geographical space. The influence of local habitat quality on species persistence is well documented; however, our results also indicate the importance of climate in regulating population sizes across a species geographical range, even in aquatic taxa.

  7. RESEARCH METHODOLOGY ON NATURAL NUTRITION OF FRESH-WATER FISH

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    Marina Piria

    2001-03-01

    Full Text Available This paper offers the entire review on the research methodology in natural nutrition of fresh-water fish. The data on fresh-water fish nutrition, particularly on fish of lower economic value, is inadequate. Reviewing the literature on assesment of nutritional parameters, the authors obviously use differenet approaches and methods. This paper is about most frequently used parameteres in qualitative and quantitative analysis. The qualitative analysis of food structure is the overall list of determinable taxa (mostlyu species and genera. The quantitative analysis comprises the assessment of particular nutritional categories by nutritional indices and coefficients. Bio-identification and numeric data processing can have numerous drawbacsk such as effect of regurgitation or the degree of digestion of the prey. The analyses of those effects proceed through statistical data processing in order to include spatial distribution of certain prey categories as well. The importance of this data is to determine the nutritional needs of potential species for culture as well as to come up with new insights on a particular aquatic ecosystem.

  8. Culture et Gestion d'Etangs a Poissons d'Eau Douce (Freshwater Fish Pond Culture and Management). Appropriate Technologies for Development. Manual Series--M37.

    Science.gov (United States)

    Chakroff, Marilyn; Druben, Laurel, Ed.

    This is the French translation of a "how-to" manual, designed as a working and teaching tool for extension agents as they establish and/or maintain local fish pond operations. The manual presents information to facilitate technology transfer and to provide a clear guide for warm water fish pond construction and management. Major topic…

  9. Extinction rates in North American freshwater fishes, 1900-2010

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    Burkhead, Noel M.

    2012-01-01

    Widespread evidence shows that the modern rates of extinction in many plants and animals exceed background rates in the fossil record. In the present article, I investigate this issue with regard to North American freshwater fishes. From 1898 to 2006, 57 taxa became extinct, and three distinct populations were extirpated from the continent. Since 1989, the numbers of extinct North American fishes have increased by 25%. From the end of the nineteenth century to the present, modern extinctions varied by decade but significantly increased after 1950 (post-1950s mean = 7.5 extinct taxa per decade). In the twentieth century, freshwater fishes had the highest extinction rate worldwide among vertebrates. The modern extinction rate for North American freshwater fishes is conservatively estimated to be 877 times greater than the background extinction rate for freshwater fishes (one extinction every 3 million years). Reasonable estimates project that future increases in extinctions will range from 53 to 86 species by 2050.

  10. Panbiogeographical analysis of Costa Rican freshwater fishes

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    Jonathan Herrera-Vásquez

    2008-03-01

    Full Text Available Track analysis and Parsimony analysis of endemicity (PAE were performed to analyze the distribution pattern of Costa Rican freshwater fishes. A basic matrix (presence/absence was prepared using the distribution of 77 freshwater fish. The data were analyzed with CLIQUE software in order to find generalized tracks (cliques. Data also were analyzed with the software NONA and Winclada version 1.00.08 in order to perform the Parsimony Analysis of Endemicity (PAE. Fourteen equally probable cliques were found with 31 species in each and the intersection of the amount was selected as a generalized track dividing the country in two main zones: Atlantic slope from Matina to Lake Nicaragua and Pacific slope from the Coto River to the basin of the Tempisque River connected with some branches oriented to the central part of the country. PAE analysis found ten cladogram areas (72 steps, CI=0.45, RI=0.64, using the "strict consensus option" two grouping zones were identified: Atlantic slope and Pacific slope. Both PAE and Track Analysis show the division of the two slopes and the orientation of the generalized track suggests new biogeographical evidence on the influence of both old and new southern elements to explain the migrations of freshwater fish into Central America during two different geological events. Rev. Biol. Trop. 56 (1: 165-170. Epub 2008 March 31.Con el objetivo de analizar el patrón de distribución de peces de agua dulce de Costa Rica se aplicó un análisis de trazos y de parsimonía de endemismos (PAE. Se construyó una matriz básica utilizando la distribución de 77 especies. Se utilizó el programa CLIQUE con la intención de encontrar los trazos generalizados y NONA y Winclada, versión 1.00.08, con el fin de llevar a cabo el PAE. Se encontró un total de 14 cliques igualmente probables con 31 especies. De esta cantidad se construyó un trazo generalizado que constituye la intersección del total, dividiendo el país en dos zonas: Atl

  11. Imperiled Freshwater and Diadromous Fishes of North America

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — List of imperiled freshwater and diadromous fishes of North America as determined by the 2008 American Fisheries Society (AFS) Endangered Species Committee (ESC) on...

  12. Sublethal haematological effects of zinc on the freshwater fish ...

    African Journals Online (AJOL)

    STORAGESEVER

    2008-06-17

    Jun 17, 2008 ... Department of Animal and Environmental Biology, Delta State University, ... exposure of a freshwater fish, Heteroclarias sp. to sublethal concentrations (5.0 .... Spain). Red and white blood cell counts were counted under light.

  13. Freshwater fishes of suriname : the genus Heptapterus (Pimelodidae)

    NARCIS (Netherlands)

    Mees, G.F.

    1967-01-01

    Ichthyological investigations in Suriname, carried out in connection with the "Brokopondo project", financed jointly by the Rijksmuseum van Natuurlijke Historie and the Stichting voor Wetenschappelijk Onderzoek in de Tropen, have yielded large collections of freshwater fishes. These collections will

  14. Microplastics ingestion by a common tropical freshwater fishing resource.

    Science.gov (United States)

    Silva-Cavalcanti, Jacqueline Santos; Silva, José Diego B; França, Elton José de; Araújo, Maria Christina Barbosa de; Gusmão, Felipe

    2017-02-01

    Microplastics pollution is widespread in marine ecosystems and a major threat to biodiversity. Nevertheless, our knowledge of the impacts of microplastics in freshwater environments and biota is still very limited. The interaction of microplastics with freshwater organisms and the risks associated with the human consumption of organisms that ingested microplastics remain major knowledge gaps. In this study, we assessed the ingestion of microplastics by Hoplosternum littorale, a common freshwater fish heavily consumed by humans in semi-arid regions of South America. We assessed the abundance and diversity of both plastic debris and other food items found in the gut of fishes caught by local fishermen. We observed that 83% of the fish had plastic debris inside the gut, the highest frequency reported for a fish species so far. Most of the plastic debris (88.6%) recovered from the guts of fish were microplastics (microplastics at the urbanized sections of the river, and that the ingestion of microplastics was negatively correlated with the diversity of other food items in the gut of individual fish. Nevertheless, microplastics ingestion appears to have a limited impact on H. littorale, and the consequences of human consumption of this fish were not assessed. Our results suggest freshwater biota are vulnerable to microplastics pollution and that urbanization is a major factor contributing to the pollution of freshwater environments with microplastics. We suggest the gut content of fish could be used as a tool for the qualitative assessment of microplastics pollution in freshwater ecosystems. Further research is needed to determine the processes responsible for the high incidence of microplastics ingestion by H. littorale, and to evaluate the risk posed to humans by the consumption of freshwater fish that ingested microplastics.

  15. Conservation status of imperiled North American freshwater and diadromous fishes

    Science.gov (United States)

    Howard L. Jelks; Stephen J. Walsh; Noel M. Burkhead; Salvador Contreras-Balderas; Edmundo Diaz-Pardo; Dean A. Hendrickson; John Lyons; Nicholas E. Mandrak; Frank McCormick; Joseph S. Nelson; Steven P. Plantania; Brady A. Porter; Claude B. Renaud; Juan Jacobo Schmitter-Soto; Eric B. Taylor; Melvin L. Jr. Warren

    2008-01-01

    This is the third compilation of imperiled (i.e., endangered, threatened, vulnerable) plus extinct freshwater and diadromous fishes of North America prepared by the American Fisheries Society?s Endangered Species Committee. Since the last revision in 1989, imperilment of inland fishes has increased substantially. This list includes 700 extant taxa representing 133...

  16. The Fresh-water Fishes of the Island of Trinidad

    NARCIS (Netherlands)

    Boeseman, M.

    1960-01-01

    A few years ago, an interesting collection of fresh-water fishes from Trinidad was presented to the Leiden Museum by Mr. J. S. KENNY, fish culturist of the Trinidad Department of Agriculture. For this gift we are also greatly indebted to Dr. P. WAGENAAR HUMMELINCK of the Zoological Laboratory at Utr

  17. Fish stem cell cultures.

    Science.gov (United States)

    Hong, Ni; Li, Zhendong; Hong, Yunhan

    2011-04-13

    Stem cells have the potential for self-renewal and differentiation. First stem cell cultures were derived 30 years ago from early developing mouse embryos. These are pluripotent embryonic stem (ES) cells. Efforts towards ES cell derivation have been attempted in other mammalian and non-mammalian species. Work with stem cell culture in fish started 20 years ago. Laboratory fish species, in particular zebrafish and medaka, have been the focus of research towards stem cell cultures. Medaka is the second organism that generated ES cells and the first that gave rise to a spermatogonial stem cell line capable of test-tube sperm production. Most recently, the first haploid stem cells capable of producing whole animals have also been generated from medaka. ES-like cells have been reported also in zebrafish and several marine species. Attempts for germline transmission of ES cell cultures and gene targeting have been reported in zebrafish. Recent years have witnessed the progress in markers and procedures for ES cell characterization. These include the identification of fish homologs/paralogs of mammalian pluripotency genes and parameters for optimal chimera formation. In addition, fish germ cell cultures and transplantation have attracted considerable interest for germline transmission and surrogate production. Haploid ES cell nuclear transfer has proven in medaka the feasibility of semi-cloning as a novel assisted reproductive technology. In this special issue on "Fish Stem Cells and Nuclear Transfer", we will focus our review on medaka to illustrate the current status and perspective of fish stem cells in research and application. We will also mention semi-cloning as a new development to conventional nuclear transfer.

  18. Fish Stem Cell Cultures

    Directory of Open Access Journals (Sweden)

    Ni Hong, Zhendong Li, Yunhan Hong

    2011-01-01

    Full Text Available Stem cells have the potential for self-renewal and differentiation. First stem cell cultures were derived 30 years ago from early developing mouse embryos. These are pluripotent embryonic stem (ES cells. Efforts towards ES cell derivation have been attempted in other mammalian and non-mammalian species. Work with stem cell culture in fish started 20 years ago. Laboratory fish species, in particular zebrafish and medaka, have been the focus of research towards stem cell cultures. Medaka is the second organism that generated ES cells and the first that gave rise to a spermatogonial stem cell line capable of test-tube sperm production. Most recently, the first haploid stem cells capable of producing whole animals have also been generated from medaka. ES-like cells have been reported also in zebrafish and several marine species. Attempts for germline transmission of ES cell cultures and gene targeting have been reported in zebrafish. Recent years have witnessed the progress in markers and procedures for ES cell characterization. These include the identification of fish homologs/paralogs of mammalian pluripotency genes and parameters for optimal chimera formation. In addition, fish germ cell cultures and transplantation have attracted considerable interest for germline transmission and surrogate production. Haploid ES cell nuclear transfer has proven in medaka the feasibility of semi-cloning as a novel assisted reproductive technology. In this special issue on “Fish Stem Cells and Nuclear Transfer”, we will focus our review on medaka to illustrate the current status and perspective of fish stem cells in research and application. We will also mention semi-cloning as a new development to conventional nuclear transfer.

  19. There and back again: migration in freshwater fishes

    DEFF Research Database (Denmark)

    Brönmark, C.; Hulthén, K.; Nilsson, P.A.

    2013-01-01

    Animal migration is an amazing phenomenon that has fascinated humans for long. Many freshwater fishes also show remarkable migrations, whereof the spectacular mass migrations of salmonids from the spawning streams are the most well known and well studied. However, recent studies have shown...... that migration occurs in a range of freshwater fish taxa from many different habitats. In this review we focus on the causes and consequences of migration in freshwater fishes. We start with an introduction of concepts and categories of migration, and then address the evolutionary causes that drive individuals...... to make these migratory journeys. The basis for the decision of an individual fish to migrate or stay resident is an evaluation of the costs and benefits of different strategies to maximize its lifetime reproductive effort. We provide examples by discussing our own work on the causes behind seasonal...

  20. Bioconcentration ratio of diazinon by freshwater fish and snail.

    Science.gov (United States)

    Kanazawa, J

    1978-11-01

    The bioconcentration ratios of diazinon from water by freshwater fishes were generally larger than that of crayfish and snails. Among fishes, the bioconcentration ratio of diazinon by topmouth gudgeon was the highest value, 152 being average. However, elimination of diazinon from fish body was linearly rapid. The influence of test concentration centration ratio of diazinon in whole body of topmouth gudgeon was increased proportional to the body weight.

  1. Prevalence of Foodborne Pathogens in Freshwater Fish in Latvia.

    Science.gov (United States)

    Terentjeva, Margarita; Eizenberga, Inga; Valciņa, Olga; Novoslavskij, Aleksandr; Strazdiņa, Vita; Bērziņš, Aivars

    2015-11-01

    The aim of this study was to detect the prevalence of Salmonella spp., Listeria monocytogenes, and Yersinia enterocolitica in freshwater fish in Latvia. In total, 235 samples, including freshly caught fish from fives lakes (n = 129) and fish from retail markets (n = 106), were collected from April 2014 to December 2014 in Latvia. Samples were tested according to International Organization for Standardization methods. No Salmonella spp. were found in fresh fish from lakes or in commercially available fish. In contrast, the overall prevalence of L. monocytogenes and Y. enterocolitica in freshwater fish was 13% (30 of 235) and 14% (34 of 235), respectively, and no significant difference between the prevalence of L. monocytogenes and Y. enterocolitica was observed (P > 0.05). All Y. enterocolitica isolates belonged to the nonpathogenic 1A biotype. Molecular serotyping of L. monocytogenes revealed that the most distributed serogroup was 1/2a-3a (65%), followed by 1/2c-3c (25%), 1/2b-3b (5%), and 4b, 4d, 4e (5%). The prevalence of L. monocytogenes and Y. enterocolitica in freshwater lake fish was 2% (2 of 129) and 3% (4 of 129), respectively. In contrast, the prevalence of L. monocytogenes and Y. enterocolitica in fish at retail markets was 26% (28 of 106) and 28% (30 of 106), respectively. In retail samples, 9 of 58 positive fish contained both L. monocytogenes and Y. enterocolitica. In general, differences in the prevalences of L. monocytogenes and Y. enterocolitica in retail samples were significantly higher than those in freshly caught fish (P < 0.05). The results of this study indicate that freshwater fish could be an important source of Y. enterocolitica and L. monocytogenes for consumers in Latvia.

  2. Effects of cage fish culture on water quality and selected biological ...

    African Journals Online (AJOL)

    Effects of cage fish culture on water quality and selected biological ... varied spatially and temporally but were generally within safe ranges for freshwater habitats. ... and depressed zooplankton diversity at WC suggested impacts from the fish ...

  3. Fish Culture Economics and Extension

    Directory of Open Access Journals (Sweden)

    E.N. Ogamba

    2012-12-01

    Full Text Available Fish culture economics and extension was reviewed to enable fish culturist plan effectively before involved in fish culture and practices. The cost and benefits of fish culture need be known before participation in the business. There is need for cross-link between research and the fishing community. Prior to introduction of any new innovation in fisheries extension and evaluation of such programmers, the agency responsible for such exercise should have full knowledge of the existing farming practice/techniques and the reasons behind them. In assessing or evaluating the impact of any new techniques or programmers, consideration should be given to such factors as natural conditions, local infrastructures, socio cultural setting, farmers’ production aims and labor economics. The study reviews the types of feasibility study, a typical feasibility study and report on a fish farm project and detail analysis of culture extension to enable fish culturist plan effectively before involved in fish culture and practices.

  4. Contribution of conservation genetics in assessing neotropical freshwater fish biodiversity

    Directory of Open Access Journals (Sweden)

    NM. Piorski

    Full Text Available Human activities have a considerable impact on hydrographic systems and fish fauna. The present review on conservation genetics of neotropical freshwater fish reveals that DNA analyses have been promoting increased knowledge on the genetic structure of fish species and their response to environmental changes. This knowledge is fundamental to the management of wild fish populations and the establishment of Evolutionary Significant Units capable of conserving genetic integrity. While population structuring can occur even in long-distance migratory fish, isolated populations can show reduced genetic variation and be at greater risk of extinction. Phylogeography and phylogeny have been powerful tools in understanding the evolution of fish populations, species and communities in distinct neotropic environments. Captive fish can be used to introduce new individuals and genes into the wild and their benefits and disadvantages can be monitored through genetic analysis. Understanding how fish biodiversity in neotropical freshwaters is generated and maintained is highly important, as these habitats are transformed by human development and fish communities are increasingly exploited as food sources to sustain a growing human population.

  5. Restricted-range fishes and the conservation of Brazilian freshwaters.

    Directory of Open Access Journals (Sweden)

    Cristiano Nogueira

    Full Text Available BACKGROUND: Freshwaters are the most threatened ecosystems on earth. Although recent assessments provide data on global priority regions for freshwater conservation, local scale priorities remain unknown. Refining the scale of global biodiversity assessments (both at terrestrial and freshwater realms and translating these into conservation priorities on the ground remains a major challenge to biodiversity science, and depends directly on species occurrence data of high taxonomic and geographic resolution. Brazil harbors the richest freshwater ichthyofauna in the world, but knowledge on endemic areas and conservation in Brazilian rivers is still scarce. METHODOLOGY/PRINCIPAL FINDINGS: Using data on environmental threats and revised species distribution data we detect and delineate 540 small watershed areas harboring 819 restricted-range fishes in Brazil. Many of these areas are already highly threatened, as 159 (29% watersheds have lost more than 70% of their original vegetation cover, and only 141 (26% show significant overlap with formally protected areas or indigenous lands. We detected 220 (40% critical watersheds overlapping hydroelectric dams or showing both poor formal protection and widespread habitat loss; these sites harbor 344 endemic fish species that may face extinction if no conservation action is in place in the near future. CONCLUSIONS/SIGNIFICANCE: We provide the first analysis of site-scale conservation priorities in the richest freshwater ecosystems of the globe. Our results corroborate the hypothesis that freshwater biodiversity has been neglected in former conservation assessments. The study provides a simple and straightforward method for detecting freshwater priority areas based on endemism and threat, and represents a starting point for integrating freshwater and terrestrial conservation in representative and biogeographically consistent site-scale conservation strategies, that may be scaled-up following naturally linked

  6. THE DEVELOPMENT OF FRESHWATER FISHING IN ELAZIĞ

    Directory of Open Access Journals (Sweden)

    Zeki BOYRAZ

    2015-04-01

    Full Text Available Increasing world population has more demand for healthy food day after day. Our research draws attention to increasing freshwater fishery in Elazığ that increased its importance depending on the fishery activities in inland water in recent years. Our reasearch area, Elazığ, is situated in the Upper Fırat part, in the southwest of Eastern Anatolia Region. The main factor that allows freshwater fishery develop in the research field is the existence of fresh water. The most important river within the city borders is Fırat and its tributaries. Hazar Lake has a 86 km2 surface area and it is 30 km far from the city center. Also the Keban Dam, 675 km2 and Karakaya Dam, 268 km2 make up the city borders. Other important dams like Kralkızı, 57 km2 and Özlüce 26 km2 are situated in near distances. In this study we will focus on the potential and development of the freshwater fishery in Elazığ.

  7. Theoretical considerations underlying Na(+) uptake mechanisms in freshwater fishes.

    Science.gov (United States)

    Parks, Scott K; Tresguerres, Martin; Goss, Greg G

    2008-11-01

    Ion and acid-base regulating mechanisms have been studied at the fish gill for almost a century. Original models proposed for Na(+) and Cl(-) uptake, and their linkage with H(+) and HCO(3)(-) secretion have changed substantially with the development of more sophisticated physiological techniques. At the freshwater fish gill, two dominant mechanisms for Na(+) uptake from dilute environments have persisted in the literature. The use of an apical Na(+)/H(+) exchanger driven by a basolateral Na(+)/K(+)-ATPase versus an apical Na(+) channel electrogenically coupled to an apical H(+)-ATPase have been the source of debate for a number of years. Advances in molecular biology have greatly enhanced our understanding of the basic ion transport mechanisms at the fish gill. However, it is imperative to ensure that thermodynamic principles are followed in the development of new models for gill ion transport. This review will focus on the recent molecular advances for Na(+) uptake in freshwater fish. Emphasis will be placed on thermodynamic constraints that prevent electroneutral apical NHE function in most freshwater environments. By combining recent advances in molecular and functional physiology of fish gills with thermodynamic considerations of ion transport, our knowledge in the field should continue to grow in a logical manner.

  8. Book review: Ecology of North American freshwater fishes

    Science.gov (United States)

    Bonar, Scott A.

    2014-01-01

    This book will be important in courses for upper undergraduates studying fish ecology or for graduate students. However, it will also be an excellent reference for the fishery manager who asks ‘Why does this fish do that?’. With the wealth of great information contained in Ross’ book, chances are an answer will be found. Review info: Ecology of North American freshwater fishes. Edited by Stephen T. Ross, 2013. ISBN: 978-0520249455, 408 pp.

  9. CAGE BREEDING OF WARM WATER FRESHWATER FISH SPECIES

    Directory of Open Access Journals (Sweden)

    Roman Safner

    2008-10-01

    Full Text Available In the 1970s, Croatia became actively involved in the contemporary trend of breeding fish in floating cages. In addition to various species of marine fishes, breeding was attempted with trout, carp, catfish, cisco and salmon. Of the above freshwater fish species, specific standards were established only for the cage breeding of rainbow trout. Cage breeding of the remaining species remained at the level of occasional attempts, with more of an experimental than a commercial character. The regular attempts to master this technique for cage breeding of warm water freshwater fish species were aimed at achieving the known benefits of such breeding, such as simplicity of implementing technological measures, easier establishment of the breeding system, simpler manipulation, the possibility of denser colonies per unit volume with a high level of production, easier adaptations to market conditions and fewer initial structural investments. Despite the many advantages, the main reasons for the lack of greater implementation of the cage breeding technology for warm water species of freshwater fish include problems in obtaining the appropriate category and quantity of healthy fry, the specificity and applicability of physical and chemical properties of the recipients and human error. In evaluating the advantages and disadvantages, the final decision on the justification of cage breeding for individual warm water freshwater species must be based on both biological and economic factors. Based on the knowledge of cage breeding acquired to date, the rule for virtually all intensive breeding systems is that it is only recommended for those species with high market demand and a high market price. The technology that demands nutrition with highly concentrated feed and other production expenditures is costly, and is therefore not profitable with less expensive fish species. Furthermore, production must be market oriented, i.e. the appropriate market research measures

  10. INVESTIGATION ON BIODIVERSITY AND CONSERVATION OF FRESHWATER FISHES IN INDONESIA

    Directory of Open Access Journals (Sweden)

    Sudarto Sudarto

    2012-12-01

    Full Text Available Indonesia is one of the richest regions in the world in terms of biodiversity. However, recent evidence has shown that tropical forests destruction has maintained at a high rate over the last few years in this country. At the same time, living resources in Indonesian freshwater ecosystems are important: this country ranks at number seven in terms of production of inland capture fisheries with 323,150 tonnes in 2008. Freshwater fishes represent 42% of the total estimated ichthyofauna, concentrated in 0.01% of the total water covered environment. This environment is closer to human activities, making it critically vulnerable to adverse impacts. Furthermore, there has been some recent debates on the general sustainability of fisheries and aquaculture production systems. This research was focused on initiating a multi-scale study of fish biodiversity in freshwater environments. Two specific actions have been started. A review based on the analyses of the existing scientific literature and of databases on fish taxonomy and distributions. In parallel to this work, a global analysis of the distribution of fish diversity in Indonesia was undertaken. This work aims at identifying the major features of this resource as well as its current and future threats.

  11. Cultivo y Manejo de Estanques Pesqueros de Agua Fresca (Freshwater Fish Pond Culture and Management). Appropriate Technologies for Development. Manual M-1D.

    Science.gov (United States)

    Chakroff, Marilyn; Druben, Laurel, Ed.

    This is the Spanish translation of a "how-to" manual, designed as a working and teaching tool for extension agents as they establish and/or maintain local fish pond operations. The manual presents information to facilitate technology transfer and to provide a clear guide for warm water fish pond construction and management. Major topic…

  12. Evolutionary landscape of amphibians emerging from ancient freshwater fish inferred from complete mitochondrial genomes.

    Science.gov (United States)

    Wang, Xiao-Tong; Zhang, Yan-Feng; Wu, Qian; Zhang, Hao

    2012-05-01

    It is very interesting that the only extant marine amphibian is the marine frog, Fejervarya cancrivora. This study investigated the reasons for this apparent rarity by conducting a phylogenetic tree analysis of the complete mitochondrial genomes from 14 amphibians, 67 freshwater fishes, four migratory fishes, 35 saltwater fishes, and one hemichordate. The results showed that amphibians, living fossil fishes, and the common ancestors of modern fishes are phylogenetically separated. In general, amphibians, living fossil fishes, saltwater fishes, and freshwater fishes are clustered in different clades. This suggests that the ancestor of living amphibians arose from a type of primordial freshwater fish, rather than the coelacanth, lungfish, or modern saltwater fish. Modern freshwater fish and modern saltwater fish were probably separated from a common ancestor by a single event, caused by crustal movement.

  13. PBDEs in freshwater mussels and fish from Flanders, Belgium

    Energy Technology Data Exchange (ETDEWEB)

    Covaci, A.; Voorspoels, S.; Schepens, P. [Antwerp Univ. (Belgium). Toxicological Center; Bervoets, L.; Hoff, P.; Voets, J.; Campenhout, K. van; Blust, R. [Antwerp Univ. (Belgium). Dept. of Ecophysiology, Biochemistry and Toxicology

    2004-09-15

    Polybrominated diphenylethers (PBDEs), a class of brominated flame retardants (BFRs), are widely used in textiles, plastics, electronic equipment and other materials for more than 30 years. Due to their massive use, PBDEs have become ubiquitously present in aquatic organisms and it was recently evidenced that their levels seem to increase rapidly. Higher PBDE concentrations were found in biota from freshwater compared to similar marine species. This is probably due to a higher pollution load found near point pollution sources that are almost exclusively inland located. Zebra mussels (Dreissena polymorpha) fulfil the requirements of a good biomonitoring organism for freshwater ecosystems: they are easy to collect and to handle, are available in sufficient numbers, have a relative long lifespan, are sedentary and resistant to various types of pollution without suffering a too high mortality and have a high filtration rate which favours the bioaccumulation of organic contaminants. Fish species are another suitable tool for the biomonitoring of organic contaminants. The occurrence of PBDEs in fish species from Europe has already received some attention, but the amount of data is still limited. The aim of this study was to evaluate the occurence of PBDEs in zebra mussels and several representative freshwater fish species (eel, carp and gibel carp) at different sites in Flanders, Belgium. In parallel, other organohalogenated contaminants, such as polychlorinated biphenyls (PCBs), p,p'-DDE and hexachlorobenzene (HCB) were also measured and their relationship with PBDEs was investigated.

  14. Freshwater fishes of Golden Gate Highlands National Park

    Directory of Open Access Journals (Sweden)

    I.A. Russell

    2005-06-01

    Full Text Available The study aimed to determine the distribution and relative abundance of freshwater fishes in the Golden Gate Highlands National Park. A total of 1778 fish specimens from three species were collected during surveys carried out in the Little Caledon River during 2002. The chubbyhead barb Barbus anoplus was the only indigenous species recorded, and comprised 99.5 of the total catch. Two of the three recorded species were alien {Cypnnus carpio, Oncorhynchus mykiss}. A further nine indigenous species could potentially occur within the park, though are unlikely to be permanent residents. Barriers formed by instream impoundments may prevent temporary immigration of indigenous fishes, but also limit the further spread of alien species in the park's rivers.

  15. Research on Risk Perception and the Influence Factors Analysis of Freshwater Edible Fish

    Directory of Open Access Journals (Sweden)

    Ruixin Liu

    2015-09-01

    Full Text Available This paper studied 192 consumers’ risk perception of freshwater fish and its influencing factors with Probit regression method based on the survey of Yangzhou city in Jiangsu province. Results showed that nearly 40% of consumers have a higher risk perception for the quality safety of freshwater fish and think that environmental hormone residues and antibiotic residues are main safety problems of freshwater fish. According to the influencing degree, the factors influencing consumer’s risk perception of freshwater fish are food safety concern, food safety situation, consumers' gender, knowledge of freshwater fish, the concept of healthy diet, the purchase experience, kids under the age of 18, education and price of freshwater fish in sequence.

  16. Parasites of freshwater fishes in North America: why so neglected?

    Science.gov (United States)

    Scholz, Tomáš; Choudhury, Anindo

    2014-02-01

    Fish parasitology has a long tradition in North America and numerous parasitologists have contributed considerably to the current knowledge of the diversity and biology of protistan and metazoan parasites of freshwater fishes. The Journal of Parasitology has been essential in disseminating this knowledge and remains a significant contributor to our understanding of fish parasites in North America as well as more broadly at the international level. However, with a few exceptions, the importance of fish parasites has decreased during the last decades, which is reflected in the considerable decline of funding and corresponding decrease of attention paid to these parasites in Canada and the United States of America. After the 'golden age' in the second half of the 20th Century, fish parasitology in Canada and the United States went in a new direction, driven by technology and a shift in priorities. In contrast, fish parasitology in Mexico has undergone rapid development since the early 1990s, partly due to extensive international collaboration and governmental funding. A critical review of the current data on the parasites of freshwater fishes in North America has revealed considerable gaps in the knowledge of their species composition, host specificity, life cycles, evolution, phylogeography, and relationships with their fish hosts. As to the key question, "Why so neglected?" this is probably because: (1) fish parasites are not in the forefront due to their lesser economic importance; (2) there is little funding for this kind of research, especially if a practical application is not immediately apparent; and (3) of shifting interests and a shortage of key personalities to train a new generation (they switched to marine habitats or other fields). Some of the opportunities for future research are outlined, such as climate change and cryptic species diversity. A significant problem challenging future research seems to be the loss of trained and experienced fish

  17. Richness and endemism of the freshwater fishes of Mexico

    Directory of Open Access Journals (Sweden)

    T. Contreras-MacBeath

    2014-02-01

    Full Text Available A study of richness and endemism of the freshwater fishes of Mexico, was carried out in order to identify hotspots and inform conservation efforts. This was done by mapping and overlaying individual species distributions by means of geographical information systems based on museum data. The study was able to confirm several previously proposed centres of freshwater fish richness (Southeastern Mexico, the Mesa Central, the Bravo-Conchos river system and the Panuco and Tuxpan-Nautla rivers. Seven areas with high ‘Corrected Weighted Endemism’ Index values were identified, with the valley of Cuatrociénegas recognized as a true centre. An alarming result was the identification of a “Ghost” centre of endemism (Llanos El Salado in southwestern Nuevo León, where six endemic cyprinodont species are all ‘extinct’ or ‘extinct in the wild’. Forty-nine single site endemics that are distributed all over Mexico were identified. The Chichancanab lagoon in the border between Yucatan and Quintana Roo, where a flock composed of six endemic cyprinodonts is present needs special mention. Three hotspots of richness plus endemism were found in Mexico, the most important of which is the Mesa Central where impacts by human activities have had a detrimental effect on fish populations.

  18. Development of Intermediate Foodstuff Derived from Freshwater Fish in China

    Institute of Scientific and Technical Information of China (English)

    WANG Xichang; Yutaka Fukuda; CHEN Shunsheng; Masahito Yokoyama; CHENG Yudong; YUAN Chunhong; QU Yinghong; Morihiko Sakaguchi

    2005-01-01

    According to the three-dimensional contour maps showing the gel-forming properties of surimi derived from freshwater fish, 8 species of surimi were classified into two types. The V-valley type surimi (silver carp, big-head carp, Chinese snake head and blunt snout bream) shows easy setting, low resistance to gel collapse, high enhancement ability with two-step heating, and narrow optimum heating temperature and time area, which are of the same characteristics as the walleye pollack surimi. In contrast, the Plateau type surimi (tilapia, grass carp, mud carp and common carp) exhibits difficult setting, high resistance to gel collapse, no enhancement ability with two-step heating, and wide optimum heating temperature and time area. There are seasonal changes of gelling properties of silver carp surimi, and the setting ability of surimi gel is higher in winter and lower in summer. The marine fish meat gels and the freshwater fish meat gels have the same acceptability for inland Chinese according to the sensory evaluation results. A slight increase in sensory scorings of kamaboko gels occurred when the extract from walleye pollack muscle was added, especially in the odor scoring of silver carp kamaboko gels.

  19. Physiological responses of fish, Piaractus mesopotamicus, to infection with the freshwater fish louse, Dolops carvalhoi. Abstract

    NARCIS (Netherlands)

    Castro, F.J.; Wendelaar Bonga, S.E.; Fernandes, N.N.

    2007-01-01

    The freshwater fish louse Dolops carvalhoi, is an ectoparasite of pacu, Piaractus mesopotamicus, that causes severe damage to its hosts. The aim of this study was to investigate the physiological responses of pacu to the stress of D. carvalhoi infection. After acclimation at the laboratory condition

  20. Phenotypical and genotypical characterization of Shewanella putrefaciens strains isolated from diseased freshwater fish.

    Science.gov (United States)

    Pękala, A; Kozińska, A; Paździor, E; Głowacka, H

    2015-03-01

    Between 2007 and 2012, a variety of disease outbreaks most often characterized by skin disorders were observed among different species of freshwater fish in Poland. In most cases, the clinical signs included focally necrotized gills, necrotic skin lesions or ulcers. Internally, haemorrhages, oedematous kidney and abnormal spleen enlargement were generally noted. The disorders were accompanied by increased mortality. Most of the problems concerned cultured common carp Cyprinus carpio L. and rainbow trout Oncorhynchus mykiss (Walbaum). Fish have been examined from a number of these farms, and additionally, the wild and ornamental fish with similar clinical signs of diseases were also tested. Bacteria were isolated consistently from lesions and internal organs. They had characteristic orange-pigmented colonies which grew in pure culture or constituted 55-95% of total bacterial flora. One hundred and eighteen isolates were collected and biochemically identified as Shewanella putrefaciens group, and this was confirmed by sequencing. Challenge tests confirmed the pathogenicity of these bacteria. This is the first report characterizing and describing S. putrefaciens as a pathogen of different species of freshwater fish in Europe. © 2014 John Wiley & Sons Ltd.

  1. Risk assessment of residual DDTs in freshwater and marine fish cultivated around the Pearl River Delta, China.

    Science.gov (United States)

    Leung, S Y; Kwok, C K; Nie, X P; Cheung, K C; Wong, M H

    2010-02-01

    Six species of freshwater fish collected from 10 fishponds in Shunde and Zhongshan, China, four species of marine fishes collected from different mariculture farms [four in Hong Kong (Tung Lung Chau, Ma Wan, Cheung Chau and Kat O) and two in mainland China (Daya Bay and Shenzhen)] together with feed (both trash fish and commercial pellets) and sediment were analyzed for DDTs. Total DDTs in freshwater fish flesh decreased in the order of: carnivores [1742 microg/kg lipid weight (l.w.)] > herbivores (165 microg/kg, l.w.) > omnivores (42.5 microg/kg, l.w.), with the highest concentration detected in mandarin fish (Siniperca chuatsi) (2641 microg/kg, l.w.). For marine fish, snubnose pompano (Trachinotus blochii) and orange-spotted grouper (Epinephelus coioides) collected in Ma Wan contained elevated levels of total DDTs (2590 and 2034 microg/kg l.w., respectively). Trash fish used in both freshwater and marine fish farms contained significantly higher levels (86.5-641 microg/kg l.w.) (p culture in order to lower the level of residual DDTs in fish muscle.

  2. EUSTRONGYLIDOSIS’ OCCURENCE IN FRESHWATER FISH FROM THE DANUBIAN DELTA AREA

    Directory of Open Access Journals (Sweden)

    LAURA URDES

    2013-12-01

    Full Text Available The groups of nemathodes who infect fish has been studyied since it has been noticed that these parasites infect a large variety of organisms, being widespread all over the world, in both freshwater and marine species. The aim of this study was to investigate the infections with Eustrongylides sp. in perch, pike, pikeperch, sheat fish, and sun perch, fished into the natural Romanian's lakes, around the Danubian Delta. Our study started on October 2005 and ended on March 2008. The fish have been clinically, pathologically and parasitologically examinated. Following these exams, we have identified the Eustrongylides sp. larvae in muscles, cavity of body and gut in perch, sheat fish and pike; in liver, mesentery and body cavity in pikeperch; into the cavity of body in sun perch. We have also noticed unspecific lesions in these structures, pointing out the presence of circulatory disturbances (congestion and hemorrhage. In perch we have observed the multiparasiting phenomenon, in which Eustrongylides sp. has been found associated with Myxobolus sp., Triaenophorus sp. and Piscicola sp. into the same host.

  3. Global imprint of historical connectivity on freshwater fish biodiversity.

    Science.gov (United States)

    Dias, Murilo S; Oberdorff, Thierry; Hugueny, Bernard; Leprieur, Fabien; Jézéquel, Céline; Cornu, Jean-François; Brosse, Sébastien; Grenouillet, Gael; Tedesco, Pablo A

    2014-09-01

    The relative importance of contemporary and historical processes is central for understanding biodiversity patterns. While several studies show that past conditions can partly explain the current biodiversity patterns, the role of history remains elusive. We reconstructed palaeo-drainage basins under lower sea level conditions (Last Glacial Maximum) to test whether the historical connectivity between basins left an imprint on the global patterns of freshwater fish biodiversity. After controlling for contemporary and past environmental conditions, we found that palaeo-connected basins displayed greater species richness but lower levels of endemism and beta diversity than did palaeo-disconnected basins. Palaeo-connected basins exhibited shallower distance decay of compositional similarity, suggesting that palaeo-river connections favoured the exchange of fish species. Finally, we found that a longer period of palaeo-connection resulted in lower levels of beta diversity. These findings reveal the first unambiguous results of the role played by history in explaining the global contemporary patterns of biodiversity.

  4. Climate change vulnerability of native and alien freshwater fishes of California: a systematic assessment approach

    National Research Council Canada - National Science Library

    Moyle, Peter B; Kiernan, Joseph D; Crain, Patrick K; Quiñones, Rebecca M

    2013-01-01

    ... vulnerability to climate change of freshwater fishes in California, USA. The method uses expert knowledge, supported by literature reviews of status and biology of the fishes, to score ten metrics for both (1...

  5. Freshwater Fish Survey of Mathews Brake Water Body - 1980 and 1981

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — A Freshwater Fish Survey of Mathews Brake water body including land not within Mathews Brake NWR. Methods included Electroshocker, creel census, and seine.

  6. Freshwater fishes distribution in Taiwan and continent of China and its biogeographical significance

    Institute of Scientific and Technical Information of China (English)

    陈宜瑜; 何舜平

    2001-01-01

    Through the comparative analysis of primary freshwater fishes in Chinese continent and the Taiwan Island, we summarize the three distinctions of distribution of freshwater fishes in these areas: (i) there exists a high similarity of freshwater fish fauna between Taiwan and the southeastern shore of the continent; (ii) some species of freshwater fish are found both in the Taiwan Island and East Himalayans; (iii) different freshwater fishes have different distributions in island arch of western Pacific where Taiwan is located, but the distribution pattern shows a similarity to that of adjacent continent. The characteristic distributions of the fishes are closely related to the change in paleogeography and geology in the area. The parsimony analysis of endemicity (PAE analysis) indicates that the three distribution patterns can be explained by the vicariance theory.

  7. Fatty acid profiles in marine and freshwater fish from fish markets in northeastern Poland

    Directory of Open Access Journals (Sweden)

    Łuczyńska Joanna

    2014-09-01

    Full Text Available The fatty acid compositions were studied in eight commercially important fish from fish markets: salmon, Salmo salar L.; cod, Gadus morhua L.; common sole, Solea solea (L.; European flounder, Platichthys flesus (L.; catfish, Clarias gariepinus (Burchell; rainbow trout, Oncorhynchus mykiss (Walb.; Nile tilapia, Oreochromis niloticus (L.; and pangasius, Pangasianodon hypophthalmus (Sauvage. The freshwater fish contained 25.69-42.18% saturated, 34.90-43.79% monounsaturated, 8.46-16.32% n-6 polyunsaturated, and 5.01-20.43% n-3 polyunsaturated acid, while marine fish contained 18.53-32.77% saturated, 17.95-49.89% monounsaturated, 3.40-11.51% n-6 polyunsaturated, and 18.74-45.42% n-3 polyunsaturated acid. Marine fish contained significantly more Ʃn-3 PUFA (29.79%, EPA (12.26%, DHA (13.20%, and a higher n-3/n-6 (6.95 ratio than freshwater fish (13.13, 2.47, 7.14, 1.29% (P≤ 0.05. There were statistically significant differences in the n-3/n-6 ratio among fish species (cod (13.40 > sole (8.47 > flounder (4.30 > rainbow trout (2.41 > catfish (1.83 ≈ salmon (1.63 > tilapia (0.57 ≈ pangasius (0.36 (P ≤0.05.

  8. Gulf-Wide Information System, Environmental Sensitivity Index Freshwater Fish Database, Geographic NAD83, LDWF (2001) [esi_freshwater_fish_LDWF_2001

    Data.gov (United States)

    Louisiana Geographic Information Center — This data set contains sensitive biological resource data for freshwater (inland) fish species in coastal Louisiana. Vector polygons represent water-bodies and other...

  9. Accumulation of heavy metals in freshwater fish in cage aquaculture at Cirata Reservoir, West Java, Indonesia.

    Science.gov (United States)

    Salami, Indah Rachmatiah Siti; Rahmawati, Suphia; Sutarto, Ratri Indri Hapsari; Jaya, Pinilih Marendra

    2008-10-01

    Freshwater fish demand in West Java is supported by cage aquaculture in reservoirs. Cirata Reservoir is one of three cascading hydropower reservoirs built along the Citarum River that receives domestic and industrial wastes. Water pollution by heavy metals, such as copper and lead, increases the health risk of humans who consume the fish. The study was aimed to evaluate the concentration of copper and lead in fish, specifically on Cyprinus carpio, that are widely cultivated in the Cirata Reservoir. Two sizes of fish were collected from five sampling points around floating-cage area. The liver of the fish was found to contain the highest copper level, followed by gills, skin, and muscle. In contrast, lead was also high in the liver, followed by skin, gills, and the muscle, but the copper concentration found in the tissues studied was much higher (31.111 +/- 17.911 mg/kg dry wt) than the lead content (0.290 +/- 0.346 mg/kg dry wt). The concentration of metals in smaller fish was always higher than than that in bigger fish. The metals content was also compared to those in fish exposed in a semistatic laboratory-scale study using Oreochromis niloticus. After 28 days exposure with 0.01 mg Cu/L, fish accumulated 21.53 mg Cu/kg dry wt, whereas for Pb exposure of 0.016 mg/L, fish accumulated up to 7 mg/kg dry wt. However, estimates of Cu and Pb intake from C. carpio consumption were still below the average daily intake (ADI) limit. This study suggested that monitoring of water quality and heavy metals in cultured fish is important in protecting human health.

  10. Shewanella putrefaciens – a new opportunistic pathogen of freshwater fish

    Directory of Open Access Journals (Sweden)

    Paździor Ewa

    2016-12-01

    Full Text Available In recent years, Shewanella putrefaciens, commonly known as a halophilic bacteria, has been associated with serious health disorders in freshwater fish. Therefore, it has been described as a new aetiological agent of the disease, named shewanellosis. S. putrefaciens is a heterogeneous group of microorganisms, belonging to the Alteromonadaceae family. Based on different criteria, three biovars and biogroups as well as four genomic groups have been distinguished. The first infections of S. putrefaciens in fish were reported in rabbitfish (Siganus rivulatus and European sea bass (Dicentrarchus labrax L.. Outbreaks in farmed fish were reported in Poland for the first time in 2004. The disease causes skin disorders and haemorrhages in internal organs. It should be noted that S. putrefaciens could also be associated with different infections in humans, such as skin and tissue infections, bacteraemia, otitis. Investigations on pathogenic mechanisms of S. putrefaciens infections are very limited. Enzymatic activity, cytotoxin secretion, adhesion ability, lipopolysaccharide (LPS, and the presence of siderophores are potential virulence factors of S. putrefaciens. Antimicrobial resistance of S. putrefaciens is different and depends on the isolates. In general, these bacteria are sensitive to antimicrobial drugs commonly used in aquaculture.

  11. Patterns of Macroinvertebrate and Fish Diversity in Freshwater Sulphide Springs

    Directory of Open Access Journals (Sweden)

    Ryan Greenway

    2014-09-01

    Full Text Available Extreme environments are characterised by the presence of physicochemical stressors and provide unique study systems to address problems in evolutionary ecology research. Sulphide springs provide an example of extreme freshwater environments; because hydrogen sulphide’s adverse physiological effects induce mortality in metazoans even at micromolar concentrations. Sulphide springs occur worldwide, but while microbial communities in sulphide springs have received broad attention, little is known about macroinvertebrates and fish inhabiting these toxic environments. We reviewed qualitative occurrence records of sulphide spring faunas on a global scale and present a quantitative case study comparing diversity patterns in sulphidic and adjacent non-sulphidic habitats across replicated river drainages in Southern Mexico. While detailed studies in most regions of the world remain scarce, available data suggests that sulphide spring faunas are characterised by low species richness. Dipterans (among macroinvertebrates and cyprinodontiforms (among fishes appear to dominate the communities in these habitats. At least in fish, there is evidence for the presence of highly endemic species and populations exclusively inhabiting sulphide springs. We provide a detailed discussion of traits that might predispose certain taxonomic groups to colonize sulphide springs, how colonizers subsequently adapt to cope with sulphide toxicity, and how adaptation may be linked to speciation processes.

  12. Distribution pattern of crustacean ectoparasites of freshwater fish from Brazil

    Directory of Open Access Journals (Sweden)

    Marcos Tavares-Dias

    Full Text Available The purpose of this study was to use the informations relating to parasite crustaceans species that was published over the course of one century (1913 to 2013, in order to search for infestation and distribution patterns among these ectoparasites in Brazilian freshwater fish species. This search was carried out on 445 samples of 119 host fish of 27 families within the orders Characiformes, Perciformes, Clupeiformes, Mugiliformes, Osteoglossiformes, Symbranchiformes, Tetraodontiformes and Siluriformes from various regions of Brazil. We organized different host-parasite systems into matrices grouping species at different taxonomic and infestation levels and according to host parameters. Five families of parasites (Ergasilidae, Argulidae, Lernaeidae, Lernaeopodidae and Cymothoidae distributed into 76 species of 27 genera were analyzed in the host samples, which presented dominance of Ergasilidae species, mainly from the genus Ergasilus. Some crustaceans are host and site-specific, especially in relation to fish in particular habitats and lifestyles (e.g. Perulernaea gamitanae, Anphira branchialis and Riggia paranensis, while other parasites frequently have no preference (e.g. Lernaea cyprinacea and Braga patagonica. We found broadly similar distribution patterns for some crustacean species among the different localities, whereas other species showed well-defined geographical patterns, and these findings were discussed.

  13. Comparative toxicity of eight metals on freshwater fish.

    Science.gov (United States)

    Shuhaimi-Othman, Mohammad; Yakub, Nadzifah; Ramle, Nur-Amalina; Abas, Ahmad

    2015-09-01

    Two freshwater fish, Rasbora sumatrana (Cyprinidae) and Poecilia reticulata (guppy; Poeciliidae), were exposed to a range of eight heavy metals (copper (Cu), cadmium (Cd), zinc (Zn), lead (Pb), nickel (Ni), iron (Fe), aluminium (Al), and manganese (Mn)) at varied concentrations for 96 h in the laboratory. Mortality was assessed and median lethal concentrations (LC50) were calculated. It was observed that the LC50 values increased with a decrease in mean exposure times, for all metals and for both fish types. The 96-h LC50 values for Cu, Cd, Zn, Pb, Ni, Fe, Al, and Mn were 0.006, 0.10, 0.46, 0.63, 0.83, 1.71, 1.53, and 5.71 mg/L for R. sumatrana and 0.038, 0.17, 1.06, 1.99, 15.62, 1.46, 6.76, and 23.91 mg/L for P. reticulata, respectively. The metal toxicity trend for R. sumatrana and P. reticulata from most to least toxic was Cu > Cd > Zn > Pb > Ni > Al > Fe > Mn and Cu > Cd > Zn > Fe > Pb > Al > Ni > Mn, respectively. Results indicated that Cu was the most toxic metal on both fish, and R. sumatrana was more sensitive than P. reticulata to all the eight metals.

  14. Predation of freshwater fish in environments with elevated carbon dioxide

    Science.gov (United States)

    Midway, Stephen R.; Hasler, Caleb T.; Wagner, Tyler; Suski, Cory D.

    2017-01-01

    Carbon dioxide (CO2) in fresh-water environments is poorly understood, yet in marine environments CO2 can affect fish behaviour, including predator–prey relationships. To examine changes in predator success in elevated CO2, we experimented with predatory Micropterus salmoides and Pimephales promelas prey. We used a two-factor fully crossed experimental design; one factor was 4-day (acclimation) CO2 concentration and the second factor CO2 concentration during 20-min predation experiments. Both factors had three treatment levels, including ambient partial pressure of CO2(pCO2; 0–1000 μatm), low pCO2 (4000–5000 μatm) and high pCO2 (8000–10 000 μatm). Micropterus salmoides was exposed to both factors, whereas P. promelas was not exposed to the acclimation factor. In total, 83 of the 96 P. promelas were consumed (n = 96 trials) and we saw no discernible effect of CO2 on predator success or time to predation. Failed strikes and time between failed strikes were too infrequent to model. Compared with marine systems, our findings are unique in that we not only saw no changes in prey capture success with increasing CO2, but we also used CO2 treatments that were substantially higher than those in past experiments. Our work demonstrated a pronounced resiliency of freshwater predators to elevated CO2 exposure, and a starting point for future work in this area.

  15. Mechanisms and regulation of Na(+) uptake by freshwater fish.

    Science.gov (United States)

    Kumai, Yusuke; Perry, Steve F

    2012-12-01

    Mechanisms of ion uptake by freshwater (FW) fish have received considerable attention over the past 80 years. Through an assortment of techniques incorporating whole animal physiology, electrophysiology and molecular biological approaches, three models have been proposed to account for Na(+) uptake. (1) Direct exchange of Na(+) and H(+) via one or more types of Na(+)/H(+) exchanger (slc9), (2) uptake of Na(+) through epithelial Na(+) channels energized by an electrical gradient created by H(+)-ATPase and (3) Na(+)/Cl(-) co-transport (slc12). While each mechanism is supported at least in part by theoretical or experimental data, there are several outstanding questions that have not yet been fully resolved. Furthermore, there are few details concerning how these Na(+) uptake mechanisms are fine tuned in response to the fluctuating FW environments. In this review, we summarize the current understanding of these three Na(+) uptake mechanisms and discuss their regulation by endocrine (cortisol and prolactin) and neurohumoral (catecholamines) factors.

  16. Cadmium concentration in three species of freshwater fishes from Keuretoe River, Northern Aceh, Indonesia

    OpenAIRE

    Muhammad A. Sarong; Abdul L. Mawardi; Muhammad Adlim; Zainal A.Muchlisin

    2013-01-01

    The objectives of present study was to evaluate cadmium (Cd) concentration in some freshwater fishes found in Keuretoe Rivers and to determine the most effective freshwater fishes (Osphronemus goramy, Anguilla marmorata and Hemibagrus nemurus) in accumulating of cadmium. A total of three sampling locations were determined using the purposive of random sampling. A total of three individual fishes at every sampling location were collected, the tissues were processed for Atomic ...

  17. Study on polychlorobiphenyl serum levels in French consumers of freshwater fish

    Energy Technology Data Exchange (ETDEWEB)

    Desvignes, Virginie, E-mail: virginie.desvignes@anses.fr [Risk Assessment Department, French Agency for Food, Environmental and Occupational Health and Safety (ANSES), 27–31, avenue du Général Leclerc, Maisons-Alfort, F-94701 (France); Volatier, Jean-Luc [Risk Assessment Department, French Agency for Food, Environmental and Occupational Health and Safety (ANSES), 27–31, avenue du Général Leclerc, Maisons-Alfort, F-94701 (France); Bels, Frédéric de [Division for Public Health and Care, French National Cancer Institute (INCa), 52, avenue André Morizet, Boulogne Billancourt Cedex, F-92513 (France); Zeghnoun, Abdelkrim [Department of Environmental Health, French Institute for Public Health Surveillance (InVS), 12, rue du Val d' Osne, Saint-Maurice, F-94415 (France); Favrot, Marie-Christine [Ministry of Health, 14, avenue Duquesne, Paris, F-75350 (France); Marchand, Philippe; Le Bizec, Bruno [LUNAM Université, Oniris, Laboratoire d' Etude des Résidus et Contaminants dans les Aliments (LABERCA), USC INRA 1329, Nantes, F-44307 (France); Rivière, Gilles; Leblanc, Jean-Charles; Merlo, Mathilde [Risk Assessment Department, French Agency for Food, Environmental and Occupational Health and Safety (ANSES), 27–31, avenue du Général Leclerc, Maisons-Alfort, F-94701 (France)

    2015-02-01

    Introduction: Polychlorobiphenyls (PCBs) are persistent pollutants that are widespread in the environment and in foodstuffs, particularly in freshwater fish, which frequently exceed the maximum levels set by European regulations. Objectives: First, we describe the consumption of freshwater fish and serum PCB levels in French anglers, a population expected to have the highest level of dietary PCB exposure. Second, we investigated whether there is a statistical relationship between serum PCB levels and the angler consumption of freshwater fish with high PCB bioaccumulation potential (PCB-BP{sup +} freshwater fish) in order to make recommendations with regard to safe consumption of freshwater fish. Methods: We conducted a survey of anglers from six sites with contrasting PCB contamination levels. The survey included a food consumption frequency questionnaire and blood samples were taken to assess serum PCB levels. We used a regression model to determine the main factors contributing to serum PCB levels. Results: Consumption of PCB-BP{sup +} freshwater fish was relatively infrequent. Serum PCB levels of the study population and of women of childbearing age were in the same range as those observed in the French population and in neighbouring European countries, but higher than in the North American population. The two factors with the highest positive association with serum PCB levels were age (R{sup 2} = 61%) and the consumption of PCB-BP{sup +} freshwater fish (R{sup 2} = 2%). Using the regression model, we calculated, for several scenarios depending on the age and gender of the population, the maximum annual frequencies for PCB-BP{sup +} freshwater fish consumption that do not exceed the critical body burden threshold. Conclusion: Following the results of this study, the French agency for food, environmental and occupational health and safety (ANSES) issued an opinion and recommended some specific maximum freshwater fish consumption frequencies to protect the French

  18. Susceptibility of various Japanese freshwater fish species to an isolate of viral haemorrhagic septicaemia virus (VHSV) genotype IVb.

    Science.gov (United States)

    Ito, Takafumi; Olesen, Niels Jørgen

    2013-11-25

    Genotype IVb of viral haemorrhagic septicaemia virus (VHSV) was isolated for the first time in the Great Lakes basin in 2003, where it spread and caused mass mortalities in several wild fish species throughout the basin. In order to prevent further spreading of the disease and to assess risks of new genotypes invading new watersheds, basic microbiological information such as pathogenicity studies are essential. In this study, experimental infections were conducted on 7 indigenous freshwater fish species from Japan by immersion with a VHSV genotype IVb isolate. In Expt 1, cumulative mortalities in bluegill Lepomis macrochirus used as positive controls, Japanese fluvial sculpin Cottus pollux, and iwana Salvelinus leucomaenis pluvius were 50, 80 and 0%, respectively. In Expt 2, cumulative mortalities of 100, 100 and 10% were observed in Japanese fluvial sculpin C. pollux, Japanese rice fish Oryzias latipes and yoshinobori Rhinogobius sp., respectively. No mortality was observed in honmoroko Gnathopogon caerulescens, akaza Liobagrus reini or Japanese striped loach Cobitis biwae. VHSV was detected by RT-PCR from samples of kidney, spleen, and brain from all dead fish, and virus re-isolation by cell culture was successful from all dead fish. We detected the virus in the brain from a few surviving bluegill 50 d post exposure by both cell culture and RT-PCR. These results revealed that VHSV IVb could become a serious threat to wild freshwater fish species in Japan, and that some surviving fish might become healthy carriers of the virus.

  19. How restructuring river connectivity changes freshwater fish biodiversity and biogeography

    Science.gov (United States)

    Lynch, Heather L.; Grant, Evan H. Campbell; Muneepeerakul, Rachata; Arunachalam, Muthukumarasamy; Rodriguez-Iturbe, Ignacio; Fagan, William F.

    2011-01-01

    Interbasin water transfer projects, in which river connectivity is restructured via man-made canals, are an increasingly popular solution to address the spatial mismatch between supply and demand of fresh water. However, the ecological consequences of such restructuring remain largely unexplored, and there are no general theoretical guidelines from which to derive these expectations. River systems provide excellent opportunities to explore how network connectivity shapes habitat occupancy, community dynamics, and biogeographic patterns. We apply a neutral model (which assumes competitive equivalence among species within a stochastic framework) to an empirically derived river network to explore how proposed changes in network connectivity may impact patterns of freshwater fish biodiversity. Without predicting the responses of individual extant species, we find the addition of canals connecting hydrologically isolated river basins facilitates the spread of common species and increases average local species richness without changing the total species richness of the system. These impacts are sensitive to the parameters controlling the spatial scale of fish dispersal, with increased dispersal affording more opportunities for biotic restructuring at the community and landscape scales. Connections between isolated basins have a much larger effect on local species richness than those connecting reaches within a river basin, even when those within-basin reaches are far apart. As a result, interbasin canal projects have the potential for long-term impacts to continental-scale riverine communities.

  20. Species persistence: a re-look at the freshwater fish fauna of Chennai, India

    Directory of Open Access Journals (Sweden)

    J.D.M. Knight

    2010-11-01

    Full Text Available Loss of habitat is one of the prime reasons for species extinction. It is generally established that certain classes of animals are more prone to extinction than others due to their restricted use of available habitats. Freshwater fish are among these sensitive animals. While local extinctions have rendered some species rare throughout their geographical range, many others have demonstrated higher levels of persistence. This paper focuses on a recent in-depth study of the primary freshwater fishes in and around Chennai. The study that spanned a period of two years recorded a total of 75 species of primary freshwater fish, of which 17 are new reports.

  1. Pond Fish Culture Practices in Nigeria

    Directory of Open Access Journals (Sweden)

    J.A. Akankali

    2011-06-01

    Full Text Available Pond fish culture practices in Nigeria was reviewed to refresh the minds of fish and other interested stake holders on some basic principles involved in pond fish culture. Fish pond system is the commonest agricultural techniques in the Niger Delta Region of Nigeria. Profit making, job creation, provision of raw materials for several industries and increase in foreign exchange earnings are some benefits. However, loss of land and introduction some water borne diseases are some disadvantages in pond fish culture. This articles reviews the fish pond management processes, stocking of ponds, feeding of fish, types of culture, fish farming combined with other branches of agriculture, rearing of fish for purposes other than food, other fish culture, types of fish used for fish culture in central east Africa, general biology of the species of value in fish culture and suitable combinations of fish for stocking to reawaken the minds of individuals, companies and government on the need to develop pond fish culture in Nigeria.

  2. Radiological impact of the nuclear power plant accident on freshwater fish in Fukushima: An overview of monitoring results.

    Science.gov (United States)

    Wada, Toshihiro; Tomiya, Atsushi; Enomoto, Masahiro; Sato, Toshiyuki; Morishita, Daigo; Izumi, Shigehiko; Niizeki, Kouji; Suzuki, Shunji; Morita, Takami; Kawata, Gyo

    2016-01-01

    Radionuclide ((131)I, (134)Cs, and (137)Cs) concentrations of monitored freshwater fish species collected from different habitats (rivers, lakes, and culture ponds) in Fukushima Prefecture during March 2011-December 2014 (total 16 species, n = 2692) were analyzed to present a detailed description of radionuclide contamination after the Fukushima Dai-ichi Nuclear Power Plant (FDNPP) accident, and to elucidate species-specific spatiotemporal declining trends of (137)Cs concentration for their respective habitats. Low concentrations of (131)I (≤24 Bq kg(-1)-wet) were detected from only 11 samples collected during March-June 2011, demonstrating that (131)I transferred to freshwater fish were not intense. In river and lake fishes, a more gradual decrease and higher radiocesium ((134)Cs, (137)Cs) concentrations were observed than in culture pond fishes, which strongly implied that radiocesium in freshwater fish species was mainly bioaccumulated through the food web in the wild. During 2011-2014, percentages above the Japanese regulatory limit of 100 Bq kg(-1)-wet for radiocesium in river and lake fish (14.0% and 39.6%, respectively) were higher than in monitored marine fish (9.9%), indicating longer-term contamination of freshwater fish species, especially in lakes. Higher radiocesium concentrations (maximum 18.7 kBq kg(-1)-wet in Oncorhynchus masou) were found in the northwestern areas from the FDNPP with higher deposition. However, radiocesium contamination levels were regarded as 1-2 orders of magnitude less than those after the Chernobyl accident. Lagged increase of (137)Cs concentration and longer ecological half-lives (Teco: 1.2-2.6 y in the central part of Fukushima Prefecture) were observed in carnivorous salmonids (O. masou, Salvelinus leucomaenis), whereas a rapid increase and decrease of (137)Cs concentration and shorter Teco (0.99 and 0.69 y) were found in herbivorous and planktivorous osmerids (Plecoglossus altivelis, Hypomesus nipponensis) with

  3. Trichodina nobilis Chen, 1963 and Trichodina reticulata Hirschmann et Partsch, 1955 from ornamental freshwater fishes in Brazil

    OpenAIRE

    ML. Martins; Marchiori,N.; Roumbedakis,K.; F Lami

    2012-01-01

    In the present work Trichodina reticulata and T. nobilis (Ciliophora: Trichodinidae) are morphologically characterised from ornamental freshwater fish culture in the State of Santa Catarina, Brazil. The prevalence of infection and a list of comparative measurements are discussed. We examined "southern platyfish" Xiphophorus maculatus (n = 35), "goldfish" Carassius auratus (n = 31), "guppy" Poecilia reticulata (n = 20), "sailfin molly" Poecilia latipinna (n = 6), "beta" Betta splendens (n = 2)...

  4. Relationships between community structure of freshwater mussels and host fishes in a central Ohio watershed

    Science.gov (United States)

    The diversity of freshwater mussel communities has declined over the past several decades within watersheds in the Midwestern United States. Host fishes play an important role in the life cycle of freshwater mussels because they serve as hosts for parasitic mussel larvae to ensure successful mussel ...

  5. An updated assessment of human activities, the environment, and freshwater fish biodiversity in Canada

    National Research Council Canada - National Science Library

    Chu, Cindy; Minns, Charles K; Lester, Nigel P; Mandrak, Nicholas E; Rosenfeld, Jordan

    2015-01-01

    ... Canada’s watersheds are changing. Chu et al. (2003) integrated indices of freshwater fish biodiversity, environmental conditions, and anthropogenic stress to identify priority watersheds for conservation and management...

  6. Biodiversity of freshwater fish of a protected river in India: comparison with unprotected habitat

    National Research Council Canada - National Science Library

    Sarkar, Uttam Kumar; Pathak, Ajey Kumar; Tyagi, Lalit Kumar; Srivastava, Satyendra Mohan; Singh, Shri Prakash; Dubey, Vineet Kumar

    2013-01-01

    In India, freshwater environments are experiencing serious threats to biodiversity, and there is an urgent priority for the search of alternative techniques to promote fish biodiversity conservation and management...

  7. EnviroAtlas - Freshwater Fishing Recreation Demand by 12-Digit HUC in the Conterminous United States

    Data.gov (United States)

    U.S. Environmental Protection Agency — This EnviroAtlas dataset includes the total number of recreational days per year demanded by people ages 18 and over for freshwater fishing by location in the...

  8. Drivers of parasite sharing among Neotropical freshwater fishes.

    Science.gov (United States)

    Braga, Mariana P; Razzolini, Emanuel; Boeger, Walter A

    2015-03-01

    Because host-parasite interactions are so ubiquitous, it is of primary interest for ecologists to understand the factors that generate, maintain and constrain these associations. Phylogenetic comparative studies have found abundant evidence for host-switching to relatively unrelated hosts, sometimes related to diversification events, in a variety of host-parasite systems. For Monogenoidea (Platyhelminthes) parasites, it has been suggested that the co-speciation model alone cannot explain host occurrences, hence host-switching and/or non-vicariant modes of speciation should be associated with the origins and diversification of several monogenoid taxa. The factors that shape broad patterns of parasite sharing were investigated using path analysis as a way to generate hypotheses about the origins of host-parasite interactions between monogenoid gill parasites and Neotropical freshwater fishes. Parasite sharing was assessed from an interaction matrix, and explanatory variables included phylogenetic relationships, environmental preferences, biological traits and geographic distribution for each host species. Although geographic distribution of hosts and host ecology are important factors to understand host-parasite interactions, especially within host lineages that share a relatively recent evolutionary history, phylogeny had the strongest overall direct effect on parasite sharing. Phylogenetic contiguity of host communities may allow a 'stepping-stone' mode of host-switching, which increases parasite sharing. Our results reinforce the importance of including evolutionary history in the study of ecological associations, including emerging infectious diseases risk assessment. © 2014 The Authors. Journal of Animal Ecology © 2014 British Ecological Society.

  9. Iridovirus disease in two ornamental tropical freshwater fishes: African lampeye and dwarf gourami.

    Science.gov (United States)

    Sudthongkong, Chaiwud; Miyata, Masato; Miyazaki, Teruo

    2002-04-05

    Many species of ornamental freshwater fishes are imported into Japan from all over the world. We found African lampeye Aplocheilichthys normani and dwarf gourami Colisa lalia suffering from an iridovirus infection just after being imported by tropical fish wholesalers from Singapore. African lampeye were cultured on the Indonesian Island of Sumatra and dwarf gourami were cultured in Malaysia before export. Diseased fishes displayed distinct histopathological signs of iridovirus infection: systemic appearance of inclusion body-bearing cells, and necrosis of splenocytes and hematopoietic cells. Electron microscopy revealed viral particles (African lampeye:180 to 200 nm in edge to edge diameter; dwarf gourami: 140 to 150 nm in diameter) in an inclusion body within the cytoplasm of inclusion body-bearing cells as well as in the cytoplasm of necrotized cells. Experimental infection with an iridovirus isolate from African lampeye (ALIV) revealed pathogenicity of ALIV to African lampeye and pearl gourami Trichogaster leeri. Polymerase chain reaction (PCR) products from ALIV and an iridovirus isolate from dwarf gourami (DGIV) using iridovirus-specific primers were indistinguishable. The nucleotide sequence of PCR products derived from ALIV (696 base pairs) and DGIV (701 base pairs) had 95.3% identity. These results indicate that ALIV and DGIV have a single origin.

  10. Epidemiological investigation of Clonorchis sinensis infection in freshwater fishes in the Pearl River Delta.

    Science.gov (United States)

    Chen, Daixiong; Chen, Jieyun; Huang, Ji; Chen, Xueying; Feng, Dana; Liang, Baofang; Che, Yuchuan; Liu, Xiaodan; Zhu, Cuihua; Li, Xiaomin; Shen, Haoxian

    2010-09-01

    Pearl River Delta region is a high clonorchiasis-endemic area in China. However, no complete epidemiological data exist regarding its infection in freshwater fishes, an important epidemic factor for Clonorchis sinensis. The present study collected freshwater fishes and shrimps from 32 sites of nine cities in the Pearl River Delta, and the encysted metacercariae of C. sinensis were detected by digesting these specimens with artificial gastric juice. The mean infection rate of freshwater fishes was 37.09% (2,160/5,824) with a mean number of 14.269 encysted metacercariae in every infected fish and 0.460 encysted metacercariae in every gram of fish meat. Of these freshwater fishes, 5,219 were domesticated, and the infection rate was 36.69% with a mean number of 10.743 encysted metacercariae in every infected fish and 0.312 encysted metacercariae in every gram of fish meat; the other 605 were wild, and the infection rate was 40.50% with a mean number of 41.829 encysted metacercariae in every infected fish and 8.812 encysted metacercariae in every gram of fish meat. A total of 228 shrimps were examined, and 3.07% of them were infected with a mean number of 1.00 encysted metacercariae in every infected shrimp. Pseudorasbora parva and Ctenopharyngodon idellus had the highest infection rate and degree of infection in the fishes studied. The results demonstrated a high incidence of C. sinensis infection in freshwater fishes and shrimps within Pearl River Delta region and a great difference in the infection rate among different collection sites and different fish species.

  11. First isolation of hirame rhabdovirus from freshwater fish in Europe

    DEFF Research Database (Denmark)

    Borzym, E.; Matras, M.; Maj-Paluch, J.

    2014-01-01

    A rhabdovirus was isolated in cell culture inoculated with tissue material from diseased grayling, Thymallus thymallus (L.), originating from a fish farm affected by a mortality episode in Poland. Diagnostics tests showed that the virus was not related to novirhabdoviruses known in Europe, nor...... China compared with the Korean isolate. An identical viral sequence was also found in brown trout, Salmo trutta trutta L., affected by mortalities in a second farm in the same region, after a likely contamination from the grayling farm. To our knowledge, this is the first report of HIRRV in Europe...

  12. Restricted-Range Fishes and the Conservation of Brazilian Freshwaters

    OpenAIRE

    Cristiano Nogueira; Paulo A. Buckup; Menezes, Naercio A.; Osvaldo T. Oyakawa; Thais P Kasecker; Ramos Neto, Mario B.; da Silva, José Maria C.

    2010-01-01

    BACKGROUND: Freshwaters are the most threatened ecosystems on earth. Although recent assessments provide data on global priority regions for freshwater conservation, local scale priorities remain unknown. Refining the scale of global biodiversity assessments (both at terrestrial and freshwater realms) and translating these into conservation priorities on the ground remains a major challenge to biodiversity science, and depends directly on species occurrence data of high taxonomic and geograph...

  13. Control of predacious flatworms Macrostomum sp. in culturing juvenile freshwater mussels

    Science.gov (United States)

    Zimmerman, L.L.; Neves, R.J.; Smith, D.G.

    2003-01-01

    Flatworms of the genus Macrostomum are voracious predators on newly metamorphosed juvenile freshwater mussels (Unionidae), which require a fish host to transform mussel larvae into free-living juveniles. Toxicity tests were performed with formalin (paracide-F, 37% formaldehyde) to determine the appropriate levels of treatment for eradicating these flatworms from host fish tanks without adversely affecting the culture of juvenile mussels. Results indicate that a 1-h shock treatment of 250 mg/L formalin or a 3-d continuous exposure to 20 mg/L of formalin kills adult Macrostomum but not fish. Observations indicate that a single treatment is insufficient to kill Macrostomum eggs, so a second treatment after 3 d is necessary to kill newly hatched flatworms. Newly metamorphosed freshwater mussels exposed to similar shock and continuous treatments of formalin were also killed. Thus, all host fish introduced for the purpose of mussel production should be quarantined and treated prophylactically to avoid the infestation of mussel culture systems with predacious flatworms.

  14. Innovation in utilization of fish tanks for fish culture among fish ...

    African Journals Online (AJOL)

    ... of fish tanks for fish culture among fish farmers in Obio/Akpor Local Government, Rivers State, Nigeria. ... Open Access DOWNLOAD FULL TEXT ... Data for this study was obtained through the administration of questionnaire and scheduled ...

  15. The Microbiota of Freshwater Fish and Freshwater Niches Contain Omega-3 Fatty Acid-Producing Shewanella Species.

    Science.gov (United States)

    Dailey, Frank E; McGraw, Joseph E; Jensen, Brittany J; Bishop, Sydney S; Lokken, James P; Dorff, Kellen J; Ripley, Michael P; Munro, James B

    2015-10-23

    Approximately 30 years ago, it was discovered that free-living bacteria isolated from cold ocean depths could produce polyunsaturated fatty acids (PUFA) such as eicosapentaenoic acid (EPA) (20:5n-3) or docosahexaenoic acid (DHA) (22:6n-3), two PUFA essential for human health. Numerous laboratories have also discovered that EPA- and/or DHA-producing bacteria, many of them members of the Shewanella genus, could be isolated from the intestinal tracts of omega-3 fatty acid-rich marine fish. If bacteria contribute omega-3 fatty acids to the host fish in general or if they assist some bacterial species in adaptation to cold, then cold freshwater fish or habitats should also harbor these producers. Thus, we undertook a study to see if these niches also contained omega-3 fatty acid producers. We were successful in isolating and characterizing unique EPA-producing strains of Shewanella from three strictly freshwater native fish species, i.e., lake whitefish (Coregonus clupeaformis), lean lake trout (Salvelinus namaycush), and walleye (Sander vitreus), and from two other freshwater nonnative fish, i.e., coho salmon (Oncorhynchus kisutch) and seeforellen brown trout (Salmo trutta). We were also able to isolate four unique free-living strains of EPA-producing Shewanella from freshwater habitats. Phylogenetic and phenotypic analyses suggest that one producer is clearly a member of the Shewanella morhuae species and another is sister to members of the marine PUFA-producing Shewanella baltica species. However, the remaining isolates have more ambiguous relationships, sharing a common ancestor with non-PUFA-producing Shewanella putrefaciens isolates rather than marine S. baltica isolates despite having a phenotype more consistent with S. baltica strains. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  16. Effects of co-cultured fish species combination and formulated feed supplement on phytoplankton community in the enclosures with inte-grated culture of freshwater pearl mussel and fishes%不同鱼类混养组合与饲喂方式对鱼蚌综合养殖水体浮游植物群落结构的影响

    Institute of Scientific and Technical Information of China (English)

    唐金玉; 王岩; 戴杨鑫; 李由明

    2014-01-01

    the enclosures with integrated culture of freshwater pearl mussel Hyriopsis cumingii and fishes. Four treatments, including stocking of grass carp, gibel carp, silver carp and bighead carp with formulated feed supplement (GISB-F ), stocking of grass carp, gibel carp, silver carp and bighead carp without formulated feed supplement (GISB-NF), stocking of silver carp and bighead carp with formulated feed supplement (SB-F), stocking of silver carp and bighead carp without formulated feed supplement (SB-NF), were examined. In each enclosure, 20 mussel, 15 grass carp, 5 gibel carp, 5 silver carp and 5 big-head carp were stocked, respectively. Results showed that the phytoplankton biomass ranged from 3.7 × 108 to 6.0 × 108 cell·L-1 during the experiment. No significant differences were found in the species composition, biomass and biodiver-sity index of phytoplankton, dominance index of the dominant species, and the ratio of cyanobacteria biomass to phy-toplankton biomass between enclosures GISB-F, GISB-NF, SB-F and SB-NF. However, the concentration of chloro-phyll a was higher in the enclosures fed formulated feed than in the enclosures without formulated feed supplement. Seasonal dynamics in phytoplankton community was observed. The dominant species of phytoplankton was green algae (Crucigenia and Scenedesmus) at the beginning of the experiment, and changed to blue-green algae (Merismopedia and Microcyslis) at the end of the experiment, suggesting the trend of occurrence of blue-green algae bloom. The factors that significantly influenced the alteration of community structure of phytoplankton included water temperature (T), ammonia (NH3-N), total nitrogen (TN) and chemical oxygen demand (CODMn). This result indicated that the changes of co-cultured species combination and formulated feed supplement could not change the trend that blue-green algal bloom finally occurred in the enclosures since NH3-N, TN and CODMn increased with the progress of the experiment.

  17. Intake of freshwater fish and associated fatty acids and risk of breast cancer.

    Science.gov (United States)

    Gao, Chang-Ming; Ding, Jian-Hua; Li, Su-Ping; Liu, Yan-Ting; Tang, Jin-Hai; Tajima, Kazuo

    2014-01-01

    To investigate the association between intake of freshwater fish and their fatty acids and the risk of breast cancer in Chinese women, we conducted a case-control study with 669 cases and 682 population-based controls in Jiangsu Province of China. A structured questionnaire was used to elicit detailed information. Unconditional logistic regression analysis was performed to calculate odds ratios (ORs) and 95% confidence intervals (CIs). Total freshwater fish intake was linked to decrease in the adjusted OR for breast cancer, but without dose-dependence. Analyses by freshwater fish species showed that consumption of black carp and silver carp was inversely related to breast cancer risk, with adjusted-ORs for the highest intake category of black carp (≥500g/month) of 0.54 (95%CI=0.33-0.92; P trendcarp (≥1000g/month) of 0.19 (95%CI=0.11-0.33; P trendcarp was positively related to breast cancer risk, with an adjusted OR for the highest intake category (≥1000g/month) of 6.09 (95%CI=3.04-12.2; P trend<0.001). Moderate intakes of SFA, PUFA, n3-PUFA and n6-PUFA from freshwater fish may decrease the risk of breast cancer among premenopausal women. The findings of this study suggest that intake of freshwater fish and their fatty acids may modify risk of breast cancer, and that different species of freshwater fish could have a different actions on breast cancer risk. Future epidemiologic studies are needed to know the effects of freshwater fish intake on breast cancer risk and the cause of these effects.

  18. Freshwater fish internals as a promising source of biologically active lipid complexes

    Directory of Open Access Journals (Sweden)

    Samoilovа D. A.

    2015-12-01

    Full Text Available The research on development of technology of fat extraction from freshwater fish entrails has been carried out. The study of mass composition of freshwater fish internals has shown that the highest content of fat (averaged 13,8 % is typical for internals of fish like carp, perch, silver carp, pike. The higher content is typical for silver carp (14.4 % permitting the possibility of its use as a source of lipid complexes. The chemical composition of the internal organs of researched objects has been studied; to justify the rational modes of extracting lipid complexes from freshwater fish internals the methods of extracting fat (thermal, enzymatic and low temperature have been tested. The quality indicators of raw fat have been analyzed and the conclusion on possibility of combining the ways of oil extraction in order to increase its output and improve the quality characteristics has been made

  19. Indirect Consequences of Recreational Fishing in Freshwater Ecosystems: An Exploration from an Australian Perspective

    Directory of Open Access Journals (Sweden)

    Shelley Burgin

    2017-02-01

    Full Text Available Recreational fishing in freshwater ecosystems is a popular pastime in Australia. Although most native fish are endemic, the fauna is depauperate compared to any landmass of similar size. With commercial fishing no longer a major industry in the country’s freshwaters, the future sustainability of these ecosystems will depend heavily on the actions of recreational fishers. However, there has been limited focus on the consequences of recreational fishing in freshwaters. There is particularly a dearth of information on the indirect consequences of fishers on the waterbodies they depend on for their sport. After outlining the respective trends in commercial and recreational fishing in Australia as a basis for placing the sport in context, the indirect impacts of fishers on water quality, movement (walking, off-road vehicles, the introduction/translocation of fauna (particularly fish, the dispersal of flora and the transmission of fish disease and pathogens are reviewed. It is concluded that with the decline of commercial fishing, the competition between commercial fin-fishing and recreational fishing is negligible, at least throughout most of the country. It is also concluded that each of the issues addressed has the potential to be detrimental to the long-term sustainability of the freshwater ecosystems that the fishers depend on for their recreation. However, information on these issues is scant. This is despite the current and predicted popularity of freshwater recreational fishing continuing to increase in Australia. Indeed, there has been insufficient quantitative assessment of the impacts to even determine what is required to ensure a comprehensive, adequate and representative protection of these freshwater ecosystems. To underpin the sustainability of inland recreational fishing in the country, it was concluded that research is required to underpin the development and implementation of appropriate policies. The alternative is that the

  20. Migration confers survival benefits against avian predators for partially migratory freshwater fish

    DEFF Research Database (Denmark)

    Skov, Christian; Chapman, Ben B.; Baktoft, Henrik

    2013-01-01

    in a freshwater fish (roach, Rutilus rutilus) that commonly migrates from lakes to streams during winter confers a significant survival benefit with respect to bird (cormorant, Phalacrocorax carbo spp.) predation. We tagged over 2000 individual fish in two Scandinavian lakes over 4 years and monitored migratory...... behaviour using passive telemetry. Next, we calculated the predation vulnerability of fish with differing migration strategies, by recovering data from passive integrated transponder tags of fish eaten by cormorants at communal roosts close to the lakes. We show that fish can reduce their predation risk...... knowledge, is one of the first studies to directly quantify a predator avoidance benefit to migrants in the field....

  1. Lysogenic infection in sub-tropical freshwater cyanobacteria cultures and natural blooms

    NARCIS (Netherlands)

    Steenhauer, L.M.; Pollard, P.C.; Brussaard, C.P.D.; Säwström, C.

    2014-01-01

    Lysogeny has been reported for a few freshwater cyanobacteria cultures, but it is unknown how prevalent it is in freshwater cyanobacteria in situ. Here we tested for lysogeny in (a) cultures of eight Australian species of subtropical freshwater cyanobacteria; (b) seven strains of one species: Cylind

  2. Lysogenic infection in sub-tropical freshwater cyanobacteria cultures and natural blooms

    NARCIS (Netherlands)

    Steenhauer, L.M.; Pollard, P.C.; Brussaard, C.P.D.; Säwström, C.

    2014-01-01

    Lysogeny has been reported for a few freshwater cyanobacteria cultures, but it is unknown how prevalent it is in freshwater cyanobacteria in situ. Here we tested for lysogeny in (a) cultures of eight Australian species of subtropical freshwater cyanobacteria; (b) seven strains of one species:

  3. Freshwater fish for nutrition security in India: Evidence from FAO data

    Directory of Open Access Journals (Sweden)

    Nagesh Kumar Barik

    2017-08-01

    Full Text Available The nutritional dimension is integral to the concept of food security. A wide range of food commodities are required to fulfill nutritional security need of the people. Animal proteins which include milk, fish, meat and egg are essentially required for nutritionally balanced diets which are available from diverse food commodities. The fish in general and freshwater fish in particular are among the fast growing sectors with increasing contributions in the nutrition security of Indian consumers. The present paper analyses relative role of fish in the nutritional security of India based on the food balance sheet data of FAO available for the period 1961–2013. The apparent fish consumption per capita per year in India has increased primarily due to increase in freshwater fish availability from 0.7 kg/cap/year in 1961–3.48 kg/cap/year in 2013, enabling increase in the overall fish availability from 1.9 to 5.04 kg/cap/year during this period. During 1961–2013, contributions of freshwater fish to non-vegetarian protein, animal protein and total protein increased from 9.1 to 27.2, 3.3–8.7 and 0.4–1.7%, respectively

  4. Fish Creek Federally Endangered Freshwater Mussel Impact Assessment

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Sediment toxicity was evaluated for one site upstream and three sites downstream of a diesel fuel spill that occurred in Fish Creek (OH and IN) in September 1993...

  5. Arsenic contamination in the freshwater fish ponds of Pearl River Delta: bioaccumulation and health risk assessment.

    Science.gov (United States)

    Cheng, Zhang; Chen, Kun-Ci; Li, Kai-Bin; Nie, Xiang-Ping; Wu, Sheng Chun; Wong, Chris Kong-Chu; Wong, Ming-Hung

    2013-07-01

    This study investigated the extent of arsenic (As) contamination in five common species of freshwater fish (northern snakehead [Channa argus], mandrarin fish [Siniperca chuatsi], largemouth bass [Lepomis macrochirous], bighead carp [Aristichthys nobilis] and grass carp [Ctenopharyngodon idellus]) and their associated fish pond sediments collected from 18 freshwater fish ponds around the Pearl River Delta (PRD). The total As concentrations detected in fish muscle and sediment in freshwater ponds around the PRD were 0.05-3.01 mg kg(-1) wet weight (w. wt) and 8.41-22.76 mg kg(-1) dry weight (d. wt), respectively. In addition, the As content was positively correlated (p < 0.05) to total organic carbon (TOC) contents in sediments. Biota sediment accumulation factor (BSAF) showed that omnivorous fish and zooplankton accumulated higher concentrations of heavy metals from the sediment than carnivorous fish. In addition, feeding habits of fish also influence As accumulation in different fish species. In this study, two typical food chains of the aquaculture ponds were selected for investigation: (1) omnivorous food chain (zooplankton, grass carp and bighead carp) and (2) predatory food chain (zooplankton, mud carp and mandarin fish). Significant linear relationships were obtained between log As and δ (15)N. The slope of the regression (-0.066 and -0.078) of the log transformed As concentrations and δ (15)N values, as biomagnifications power, indicated there was no magnification or diminution of As from lower trophic levels (zooplankton) to fish in the aquaculture ponds. Consumption of largemouth bass, northern snakehead and bighead carp might impose health risks of Hong Kong residents consuming these fish to the local population, due to the fact that its cancer risk (CR) value exceeded the upper limit of the acceptable risk levels (10(-4)) stipulated by the USEPA.

  6. Vectors of invasions in freshwater invertebrates and fishes

    Science.gov (United States)

    Fuller, Pam L.; Canning-Clode, João

    2015-01-01

    Without human assistance, the terrestrial environment and oceans represent barriers to the dispersal of freshwater aquatic organisms. The ability to overcome such barriers depends on the existence of anthropogenic vectors that can transport live organisms to new areas, and the species’ biology to survive the transportation and transplantation into the new environment (Johnson et al., 2006).

  7. Biogeography of freshwater fishes from the Northeastern Mata Atlântica freshwater ecoregion: distribution, endemism, and area relationships

    Directory of Open Access Journals (Sweden)

    Priscila Camelier

    Full Text Available The Northeastern Mata Atlântica freshwater ecoregion (NMAF includes part of the eastern Brazilian coastal drainages, has high level of fish endemism and great biogeographic significance. A taxonomic inventory of freshwater fishes from 25 drainages of the NMAF ecoregion and a biogeographic analysis using the Parsimony Analysis of Endemicity (PAE method were carried out. A total of 192 native species was listed. The PAE method was applied to 24 basins and 37 species, resulting in five equally parsimonious area diagrams. The strict consensus diagram indicates the existence of two main groups of basins throughout the NMAF ecoregion. These groups were denominated: North Group and Central-South Group. The Central-South Group shows a basal polytomy composed by two Groups (Central Group and South Group plus the rio Itapemirim basin. The North Group is composed by eight drainages from the rio Sergipe to the rio Paraguaçu, the Central Group by five drainages from the rio Cachoeira to the rio Jequitinhonha, and the South Group by nine drainages from the rio Buranhém to the rio Doce. Comments about the species distribution and the fish fauna shared with adjacent ecoregions are provided. We also present a comparison of the hypothesis of river relationships proposed herein with published phylogenetic hypotheses that include taxa relevant to this study.

  8. Climate change vulnerability of native and alien freshwater fishes of California: a systematic assessment approach.

    Directory of Open Access Journals (Sweden)

    Peter B Moyle

    Full Text Available Freshwater fishes are highly vulnerable to human-caused climate change. Because quantitative data on status and trends are unavailable for most fish species, a systematic assessment approach that incorporates expert knowledge was developed to determine status and future vulnerability to climate change of freshwater fishes in California, USA. The method uses expert knowledge, supported by literature reviews of status and biology of the fishes, to score ten metrics for both (1 current status of each species (baseline vulnerability to extinction and (2 likely future impacts of climate change (vulnerability to extinction. Baseline and climate change vulnerability scores were derived for 121 native and 43 alien fish species. The two scores were highly correlated and were concordant among different scorers. Native species had both greater baseline and greater climate change vulnerability than did alien species. Fifty percent of California's native fish fauna was assessed as having critical or high baseline vulnerability to extinction whereas all alien species were classified as being less or least vulnerable. For vulnerability to climate change, 82% of native species were classified as highly vulnerable, compared with only 19% for aliens. Predicted climate change effects on freshwater environments will dramatically change the fish fauna of California. Most native fishes will suffer population declines and become more restricted in their distributions; some will likely be driven to extinction. Fishes requiring cold water (<22°C are particularly likely to go extinct. In contrast, most alien fishes will thrive, with some species increasing in abundance and range. However, a few alien species will likewise be negatively affected through loss of aquatic habitats during severe droughts and physiologically stressful conditions present in most waterways during summer. Our method has high utility for predicting vulnerability to climate change of diverse fish

  9. Climate change vulnerability of native and alien freshwater fishes of California: a systematic assessment approach.

    Science.gov (United States)

    Moyle, Peter B; Kiernan, Joseph D; Crain, Patrick K; Quiñones, Rebecca M

    2013-01-01

    Freshwater fishes are highly vulnerable to human-caused climate change. Because quantitative data on status and trends are unavailable for most fish species, a systematic assessment approach that incorporates expert knowledge was developed to determine status and future vulnerability to climate change of freshwater fishes in California, USA. The method uses expert knowledge, supported by literature reviews of status and biology of the fishes, to score ten metrics for both (1) current status of each species (baseline vulnerability to extinction) and (2) likely future impacts of climate change (vulnerability to extinction). Baseline and climate change vulnerability scores were derived for 121 native and 43 alien fish species. The two scores were highly correlated and were concordant among different scorers. Native species had both greater baseline and greater climate change vulnerability than did alien species. Fifty percent of California's native fish fauna was assessed as having critical or high baseline vulnerability to extinction whereas all alien species were classified as being less or least vulnerable. For vulnerability to climate change, 82% of native species were classified as highly vulnerable, compared with only 19% for aliens. Predicted climate change effects on freshwater environments will dramatically change the fish fauna of California. Most native fishes will suffer population declines and become more restricted in their distributions; some will likely be driven to extinction. Fishes requiring cold water (fishes will thrive, with some species increasing in abundance and range. However, a few alien species will likewise be negatively affected through loss of aquatic habitats during severe droughts and physiologically stressful conditions present in most waterways during summer. Our method has high utility for predicting vulnerability to climate change of diverse fish species. It should be useful for setting conservation priorities in many different

  10. Socio-economic drivers of freshwater fish declines in a changing climate: a New Zealand perspective.

    Science.gov (United States)

    Ling, N

    2010-11-01

    New Zealand has a freshwater fish fauna characterized by high levels of national and local endemism and which is threatened by anthropogenic stressors including habitat destruction or deterioration, commercial harvest, pollution and interactions with invasive exotic species. Significant expansion of New Zealand's dairy production has recently created further deterioration of lowland water quality and greater pressure for water allocation in drier eastern regions of the South Island. New Zealand has large freshwater resources and its climate is predicted to experience less dramatic changes in mean annual temperature and precipitation than many other regions of the world as a result of anthropogenic climate change. Predicted changes in regional climate and further expansion of the dairy industry, however, will impose similar pressures on freshwater resources in northern New Zealand to those already acting to threaten freshwater biodiversity in the eastern South Island.

  11. Patterns of distribution of the helminth parasites of freshwater fishes of Mexico.

    Directory of Open Access Journals (Sweden)

    Benjamín Quiroz-Martínez

    Full Text Available In order to draw patterns in helminth parasite composition and species richness in Mexican freshwater fishes we analyse a presence-absence matrix representing every species of adult helminth parasites of freshwater fishes from 23 Mexican hydrological basins. We examine the distributional patterns of the helminth parasites with regard to the main hydrological basins of the country, and in doing so we identify areas of high diversity and point out the biotic similarities and differences among drainage basins. Our dataset allows us to evaluate the relationships among drainage basins in terms of helminth diversity. This paper shows that the helminth fauna of freshwater fishes of Mexico can characterise hydrological basins the same way as fish families do, and that the basins of south-eastern Mexico are home to a rich, predominantly Neotropical, helminth fauna whereas the basins of the Mexican Highland Plateau and the Nearctic area of Mexico harbour a less diverse Nearctic fauna, following the same pattern of distribution of their fish host families. The composition of the helminth fauna of each particular basin depends on the structure of the fish community rather than on the limnological characteristics and geographical position of the basin itself. This work shows distance decay of similarity and a clear linkage between host and parasite distributions.

  12. Trichodina nobilis Chen, 1963 and Trichodina reticulata Hirschmann et Partsch, 1955 from ornamental freshwater fishes in Brazil

    Directory of Open Access Journals (Sweden)

    ML Martins

    Full Text Available In the present work Trichodina reticulata and T. nobilis (Ciliophora: Trichodinidae are morphologically characterised from ornamental freshwater fish culture in the State of Santa Catarina, Brazil. The prevalence of infection and a list of comparative measurements are discussed. We examined "southern platyfish" Xiphophorus maculatus (n = 35, "goldfish" Carassius auratus (n = 31, "guppy" Poecilia reticulata (n = 20, "sailfin molly" Poecilia latipinna (n = 6, "beta" Betta splendens (n = 2 and "spotted headstander" Chilodus punctatus (n = 1. After being anesthetised in a benzocaine solution, fishes were examined for parasitological evaluation. A total of 51.57% fishes were parasitised by Trichodina spp. Carassius auratus was the most parasitised species, followed by X. maculatus and P. reticulata. Beta splendens, C. punctatus and P. latipinna were not parasitised by any trichodinid species. Two species of Trichodina were collected from the skin of fish: T. nobilis was found in C. auratus, P. reticulata and X. maculatus and T. reticulata was only observed in C. auratus. The importance of adequate handling in ornamental fish culture are also discussed.

  13. Trichodina nobilis Chen, 1963 and Trichodina reticulata Hirschmann et Partsch, 1955 from ornamental freshwater fishes in Brazil.

    Science.gov (United States)

    Martins, M L; Marchiori, N; Roumbedakis, K; Lami, F

    2012-05-01

    In the present work Trichodina reticulata and T. nobilis (Ciliophora: Trichodinidae) are morphologically characterised from ornamental freshwater fish culture in the State of Santa Catarina, Brazil. The prevalence of infection and a list of comparative measurements are discussed. We examined "southern platyfish" Xiphophorus maculatus (n = 35), "goldfish" Carassius auratus (n = 31), "guppy" Poecilia reticulata (n = 20), "sailfin molly" Poecilia latipinna (n = 6), "beta" Betta splendens (n = 2) and "spotted headstander" Chilodus punctatus (n = 1). After being anesthetised in a benzocaine solution, fishes were examined for parasitological evaluation. A total of 51.57% fishes were parasitised by Trichodina spp. Carassius auratus was the most parasitised species, followed by X. maculatus and P. reticulata. Beta splendens, C. punctatus and P. latipinna were not parasitised by any trichodinid species. Two species of Trichodina were collected from the skin of fish: T. nobilis was found in C. auratus, P. reticulata and X. maculatus and T. reticulata was only observed in C. auratus. The importance of adequate handling in ornamental fish culture are also discussed.

  14. Survival of cool and warm freshwater fish following chloramine-T exposure

    Science.gov (United States)

    Gaikowski, M.P.; Larson, W.J.; Gingerich, W.H.

    2008-01-01

    Chloramine-T is presently available in the USA to control mortalities associated with bacterial gill disease or external columnaris only through an Investigational New Animal Drug Permit authorized by the US Food and Drug Administration (FDA). Its US approval hinges on FDA's acceptance of several key data, including those describing animal safety. Chloramine-T is presently applied in US aquaculture, by permit only, once daily on consecutive or alternate days for 1??h at 10 to 20??mg/L to control mortalities associated with bacterial gill disease or external columnaris. Our objective was to determine the safety of chloramine-T bath exposures at multiples of the proposed maximum treatment concentration (i.e., 0, 20, 60, 100, and 200??mg/L) administered on four consecutive days at 20????C to lake sturgeon Acipenser fulvescens, northern pike Esox lucius, and walleye Sander vitreum, or at 27????C to channel catfish Ictalurus punctatus, and largemouth bass Micropterus salmoides. All fish were tested as five to eight week old fry except for walleye and channel catfish which were tested as both fry and fingerling (fingerlings were at least four weeks older than the fry tested). Walleye and channel catfish were selected to evaluate the effects of life stage (fry vs. fingerling), temperature (walleye - 15, 20, or 25????C; channel catfish - 22, 27, or 32????C), exposure duration (60 vs. 180??min), and water chemistry (walleye only - reconstituted soft water vs. well water). Except for channel catfish fry, survival was significantly reduced only when fish were treated at 100 or 200??mg/L. Channel catfish fry survival was significantly reduced when exposed at 60??mg/L for 180??min at 27????C. Based on our mortality data, chloramine-T administered once daily for 60??min on four consecutive days at concentrations of up to 20??mg/L is not likely to adversely affect survival of cool or warmwater fish cultured in freshwater. Crown Copyright ?? 2007.

  15. Characterization factors for water consumption and greenhouse gas emissions based on freshwater fish species extinction.

    Science.gov (United States)

    Hanafiah, Marlia M; Xenopoulos, Marguerite A; Pfister, Stephan; Leuven, Rob S E W; Huijbregts, Mark A J

    2011-06-15

    Human-induced changes in water consumption and global warming are likely to reduce the species richness of freshwater ecosystems. So far, these impacts have not been addressed in the context of life cycle assessment (LCA). Here, we derived characterization factors for water consumption and global warming based on freshwater fish species loss. Calculation of characterization factors for potential freshwater fish losses from water consumption were estimated using a generic species-river discharge curve for 214 global river basins. We also derived characterization factors for potential freshwater fish species losses per unit of greenhouse gas emission. Based on five global climate scenarios, characterization factors for 63 greenhouse gas emissions were calculated. Depending on the river considered, characterization factors for water consumption can differ up to 3 orders of magnitude. Characterization factors for greenhouse gas emissions can vary up to 5 orders of magnitude, depending on the atmospheric residence time and radiative forcing efficiency of greenhouse gas emissions. An emission of 1 ton of CO₂ is expected to cause the same impact on potential fish species disappearance as the water consumption of 10-1000 m³, depending on the river basin considered. Our results make it possible to compare the impact of water consumption with greenhouse gas emissions.

  16. The freshwater fishes of Java, as observed by Kuhl and van Hasselt in 1820-23

    NARCIS (Netherlands)

    Roberts, T.R.

    1993-01-01

    A catalog of 79 species of freshwater fishes collected by Kuhl and van Hasselt in western Java in 1820-23 is presented, based on examination of publications, archival materials and specimens in Paris and Leiden. Archival material includes copies of their original drawings (many watercoloured) and

  17. Global streamflow and thermal habitats of freshwater fishes under climate change

    NARCIS (Netherlands)

    Vliet, van M.T.H.; Ludwig, F.; Kabat, P.

    2013-01-01

    Climate change will affect future flow and thermal regimes of rivers. This will directly affect freshwater habitats and ecosystem health. In particular fish species, which are strongly adapted to a certain level of flow variability will be sensitive to future changes in flow regime. In addition, all

  18. PRELIMINARY STUDY OF FISH CULTURE IN ABANDONED SAND MINING POOL

    Directory of Open Access Journals (Sweden)

    Bambang Gunadi

    2006-12-01

    Full Text Available One of main problems in freshwater aquaculture development in Indonesia, especially in Java, is unavailability of developing zone. It is important to find an underutilized area that meets for industrial scale freshwater aquaculture, i.e. sufficient water supply, wide area, and located in one area or zone. The abandoned mining (sand, tin, etc. pools distributed along the country might be the potential area for freshwater aquaculture business. For example, there are at least 13 water pools with total surface area of 250 ha at 15 km side of Citarum River in Karawang District (West Java Province. This study was conducted to obtain preliminary data about the prospect and potency of fish culture (tilapia, clariid catfish, and ‘patin’ catfish in abandoned sand-mining pools in Karawang District. Mini floating net cages of 1 x 1 x 1.5 m3 size were used for culturing fish, i.e. patin catfish (Pangasianodon hypophthalmus, nile tilapia (Oreochromis niloticus, and clariid catfish (Clarias gariepinus, separately. Patin catfish were stocked at a size of 2 g with a density of 300 fish per cage, tilapia were stocked at a size of 6 g with a density of 400 fish per cage, while  the clariid catfish were stocked at a size of 1.4 g with a density of 980 fish per cage. A floating commercial feed (30%—32% protein, 3%—5% fat was used at a daily rate of 9% biomass weight at the beginning and reduced gradually to 3% at the final culture period. Observed data showed that patin catfish grew from the initial size of 2.08 g to the final size 299.59 g in 5 months, nile tilapia grew from individual initial size of 5.92 g to the final size of 247.12 g in 14 weeks, and clariid catfish grew from initial size of 1.39 g to the final size of 73.10 g in 8 weeks. These three species were technically prospective for aquaculture development in the abandoned sand-mining pools.

  19. FishTraits: a database of ecological and life-history traits of freshwater fishes of the United States

    Science.gov (United States)

    Angermeier, Paul L.; Frimpong, Emmanuel A.

    2011-01-01

    The need for integrated and widely accessible sources of species traits data to facilitate studies of ecology, conservation, and management has motivated development of traits databases for various taxa. In spite of the increasing number of traits-based analyses of freshwater fishes in the United States, no consolidated database of traits of this group exists publicly, and much useful information on these species is documented only in obscure sources. The largely inaccessible and unconsolidated traits information makes large-scale analysis involving many fishes and/or traits particularly challenging. We have compiled a database of > 100 traits for 809 (731 native and 78 nonnative) fish species found in freshwaters of the conterminous United States, including 37 native families and 145 native genera. The database, named Fish Traits, contains information on four major categories of traits: (1) trophic ecology; (2) body size, reproductive ecology, and life history; (3) habitat preferences; and (4) salinity and temperature tolerances. Information on geographic distribution and conservation status was also compiled. The database enhances many opportunities for conducting research on fish species traits and constitutes the first step toward establishing a central repository for a continually expanding set of traits of North American fishes.

  20. The global status of freshwater fish age validation studies and a prioritization framework for future research

    Science.gov (United States)

    Pope, Kevin L.; Hamel, Martin J.; Pegg, Mark A.; Spurgeon, Jonathan J.

    2016-01-01

    Age information derived from calcified structures is commonly used to estimate recruitment, growth, and mortality for fish populations. Validation of daily or annual marks on age structures is often assumed, presumably due to a lack of general knowledge concerning the status of age validation studies. Therefore, the current status of freshwater fish age validation studies was summarized to show where additional effort is needed, and increase the accessibility of validation studies to researchers. In total, 1351 original peer-reviewed articles were reviewed from freshwater systems that studied age in fish. Periodicity and age validation studies were found for 88 freshwater species comprising 21 fish families. The number of age validation studies has increased over the last 30 years following previous calls for more research; however, few species have validated structures spanning all life stages. In addition, few fishes of conservation concern have validated ageing structures. A prioritization framework, using a combination of eight characteristics, is offered to direct future age validation studies and close the validation information gap. Additional study, using the offered prioritization framework, and increased availability of published studies that incorporate uncertainty when presenting research results dealing with age information are needed.

  1. Total Suspended Solids Effects on Freshwater Lake Biota Other than Fish.

    Science.gov (United States)

    Chapman, Peter M; Hayward, April; Faithful, John

    2017-08-17

    Protective benchmarks for the effects of total suspended solids (TSS) on freshwater aquatic biota primarily focus on fish; whether these benchmarks will also protect their prey or co-existing lower trophic level aquatic biota was uncertain. We conducted an extensive literature review of TSS effects on those organisms comprising the food webs upon which fish living in lakes depend: phytoplankton, zooplankton, periphyton, and benthic invertebrates. The available literature indicates that TSS benchmarks that protect sensitive life stages of lake fish will also protect their supporting food webs; in other words, the function of lake aquatic communities will be protected and maintained.

  2. Parasites of marine, freshwater and farmed fishes of Portugal: a review

    Directory of Open Access Journals (Sweden)

    Jorge da Costa Eiras

    Full Text Available Abstract An extensive literature review is made of the parasites in marine and freshwater fish in mainland Portugal, the Portuguese archipelagos of the Azores and Madeira, as well as in farmed fish. The host(s of each parasite species, its location in the host, site of capture of the host, whenever possible, and all the available bibliographic references are described. The economic importance of some parasites and the zoonotic relevance of some parasitic forms are discussed. A general overview of the data is provided, and some research lines are suggested in order to increase and complement the current body of knowledge about the parasites of fish from Portugal.

  3. Content comparison of polycyclic aromatic hydrocarbons (PAHs in traditionally smoked freshwater fish

    Directory of Open Access Journals (Sweden)

    Renata Pietrzak-Fiećko

    2015-09-01

    Full Text Available The aim of this study was to compare the content of chosen PAHs (benzo[a]pyrene, benzo[a]anthracene, chrysene, benzo[b]fluoranthene in meat of different freshwater fish species that were traditionally (directly smoked. The survey covered 16 freshwater fish samples of four species: rainbow trout (Oncorhynchus mykiss, carp (Cyprinus carpio, vendace (Coregonus albula and eel (Anguilla anguilla. Average content of sum of four PAHs in meat of trout, carp, vendace and eel was: 2.73, 8.23, 6.45 and 3.65 µg/kg of meat, respectively. Maximum levels of chosen PAHs in meat of examined fish species were not exceeded by any of the samples. Conducted studies confirmed that meat of traditionally smoked trout, carp, vendace and eel is safe in terms of content of the analysed PAHs.

  4. Effects of carbohydrate source for maintaining a high C:N ratio and fish driven re-suspension on pond ecology and production in periphyton-based freshwater prawn culture systems

    NARCIS (Netherlands)

    Asaduzzaman, M.; Wahab, M.A.; Verdegem, M.C.J.; Adhikary, R.K.; Rahman, S.M.S.; Azim, M.E.; Verreth, J.A.J.

    2010-01-01

    The present research investigated the effect of carbohydrate (CH) source for maintaining a high C:N ratio, and tilapia driven bioturbation on pond ecology, production and economical performances in C/N controlled periphyton-based (C/N-CP) freshwater prawn ponds. Two carbohydrate sources (high-cost t

  5. Cadmium concentration in three species of freshwater fishes from Keuretoe River, Northern Aceh, Indonesia

    Directory of Open Access Journals (Sweden)

    Muhammad A. Sarong

    2013-09-01

    Full Text Available The objectives of present study was to evaluate cadmium (Cd concentration in some freshwater fishes found in Keuretoe Rivers and to determine the most effective freshwater fishes (Osphronemus goramy, Anguilla marmorata and Hemibagrus nemurus in accumulating of cadmium. A total of three sampling locations were determined using the purposive of random sampling. A total of three individual fishes at every sampling location were collected, the tissues were processed for Atomic Absorption Spectrophotometry (AAS and data were analyzed by Anova followed by Duncan multiple range test. The result revealed that the cadmium concentration ranges between 0.0064 ppm and 0.0260 ppm. Anova test showed that the sampling locations did not significantly affect the cadmium accumulation in fishes, but the fish species gave significantly effect on the cadmium accumulation in their tissue. The Duncan test showed that high cadmium accumulation was found in gourami at Station 2 and in mottled eel at Station 1, the concentrations were significantly different from Cd content in bagrid catfish at all sampling locations. The higher of cadmium pollution was recorded in Station 3 and gourami accumulated higher cadmium than other fishes studied. Keuretoe River is contaminated with cadmium and the fishes should not be consumed.

  6. Comparison of the Respiratory Metabolism of Juvenile Litopenaeus vannamei Cultured in Seawater and Freshwater

    Institute of Scientific and Technical Information of China (English)

    DING Sen; WANG Fang; DONG Shuanglin; LI Ying

    2014-01-01

    Litopenaeus vannamei, a euryhaline species, can be cultured at a wide range of salinities. The emergence of freshwater pond-culture of L. vannamei is an important prelude to the continued development of shrimp culture in China. In this study, we com-pared the respiratory metabolism of juvenile L. vannamei cultured in freshwater and saltwater by measuring their oxygen consump-tion rate (OCR), ammonium-type nitrogen excretion rate (AER) and pyruvate kinase (PK) and lactate dehydrogenase (LDH) activi-ties at different molting stages in order to physiecologically characterize juvenile L. vannamei under freshwater conditions. The re-sults showed that OCR was significantly higher in saltwater than in freshwater at all stages of molting cycle. However, variation of OCR among molting stages in saltwater was similar with that in freshwater, and the highest OCR was observed at post-molting stage. At all stages of molting cycle, AER was significantly higher in freshwater than in saltwater, and the highest was observed at post-molting stage. The activity of PK was significantly higher in saltwater than in freshwater. Conversely, the activity of LDH was higher in freshwater than in saltwater in general. Significant variation of PK and LDH activities in molting cycle was observed in saltwater and freshwater. The results indicated that aerobic metabolism of juvenile L. vannamei was more active in saltwater than in freshwater;while its protein metabolism was more active in freshwater than in saltwater.

  7. Fungal infection in freshwater fishes of Andhra Pradesh, India

    African Journals Online (AJOL)

    Biotechnology

    2015-02-11

    Feb 11, 2015 ... pieces of mycelia taken out from infected parts of fish body were washed thoroughly ... wrapped in aluminum foils were sterilized in hot air oven at 120°C tem for 24 h. Filtered ..... A survey of impact and evaluation fisheries in ...

  8. Fungal Infections in Some Economically Important Freshwater Fishes

    Directory of Open Access Journals (Sweden)

    Zafar Iqbal*, Uzma Sheikh and Rabia Mughal

    2012-06-01

    Full Text Available Aim of this study was to investigate fungal infections in four species of carps including goldfish, Carassius (C. auratus L.; silver carp, Hypophthalmichthys (H. molitrix Richardsons; rahu, Labeo (L. rohita Hamilton and Ctenopharyngodon (C. idella Valenciennes. Nine specimens of each species were studied for the presence of fungal infections. Infected fishes showed clinical signs such as fungal growth on skin, fins, eyes, eroded fins and scales, hemorrhages on body surface and abdominal distension. The specimens from infected organs of fish were inoculated on each, malt extract, Sabouraud dextrose and potato dextrose agars. The fungal colonies of white, black, green, grey and brown colors were observed in the agar plates. Slides were prepared and stained with 0.05% Trypan blue in lactophenol. C. auratus showed the highest infection rate (44.4% followed by H. molitrix and L. rohita (11.1% each. Five fungal species viz. Aspergillus (33.3%, Penicillium (22.2%, Alternaria (27.7%, Blastomyces spp (11.1% and Rhizopus (5.5% were isolated. Posterior part of the fish had significantly (P=0.05 higher (62.5% infection as compared to anterior part (37.5%. The caudal fin with 31.25% infection was the single most affected area. This study showed that most of the fungi isolated from fishes are considered as normal mycoflora, yet many fungi can cause natural infections in ponds and aquarium.

  9. Characterizing lentic freshwater fish assemblages using multiple sampling methods

    Science.gov (United States)

    Fischer, Jesse R.; Quist, Michael

    2014-01-01

    Characterizing fish assemblages in lentic ecosystems is difficult, and multiple sampling methods are almost always necessary to gain reliable estimates of indices such as species richness. However, most research focused on lentic fish sampling methodology has targeted recreationally important species, and little to no information is available regarding the influence of multiple methods and timing (i.e., temporal variation) on characterizing entire fish assemblages. Therefore, six lakes and impoundments (48–1,557 ha surface area) were sampled seasonally with seven gear types to evaluate the combined influence of sampling methods and timing on the number of species and individuals sampled. Probabilities of detection for species indicated strong selectivities and seasonal trends that provide guidance on optimal seasons to use gears when targeting multiple species. The evaluation of species richness and number of individuals sampled using multiple gear combinations demonstrated that appreciable benefits over relatively few gears (e.g., to four) used in optimal seasons were not present. Specifically, over 90 % of the species encountered with all gear types and season combinations (N = 19) from six lakes and reservoirs were sampled with nighttime boat electrofishing in the fall and benthic trawling, modified-fyke, and mini-fyke netting during the summer. Our results indicated that the characterization of lentic fish assemblages was highly influenced by the selection of sampling gears and seasons, but did not appear to be influenced by waterbody type (i.e., natural lake, impoundment). The standardization of data collected with multiple methods and seasons to account for bias is imperative to monitoring of lentic ecosystems and will provide researchers with increased reliability in their interpretations and decisions made using information on lentic fish assemblages.

  10. Glacial cycles as an allopatric speciation pump in north-eastern American freshwater fishes.

    Science.gov (United States)

    April, Julien; Hanner, Robert H; Dion-Côté, Anne-Marie; Bernatchez, Louis

    2013-01-01

    Allopatric speciation may be the principal mechanism generating new species. Yet, it remains difficult to judge the generality of this process because few studies have provided evidence that geographic isolation has triggered the development of reproductive isolation over multiple species of a regional fauna. Here, we first combine results from new empirical data sets (7 taxa) and published literature (9 taxa) to show that the eastern Great Lakes drainage represents a multispecies suture zone for glacial lineages of freshwater fishes with variable levels of genetic divergence. Second, we performed amplified fragment length polymorphism analyses among four pairs of lineages. Results indicate that lineages with relatively deep levels of mtDNA 5' COI (barcode) sequence divergence (>2%) developed strong reproductive barriers, while lineages with lower levels of divergence show weaker reproductive isolation when found in sympatry. This suggests that a threshold of 2% sequence divergence at mtDNA could be used as a first step to flag cryptic species in North American freshwater fishes. By describing different levels of divergence and reproductive isolation in different co-occurring fishes, we offer strong evidence that allopatric speciation has contributed significantly to the diversification of north-eastern American freshwater fishes and confirm that Pleistocene glacial cycles can be viewed as a 'speciation pump' that played a predominant role in generating biodiversity. © 2012 Blackwell Publishing Ltd.

  11. A review of the global relationship among freshwater fish, autotrophic activity, and regional climate

    Science.gov (United States)

    Deines, Andrew M.; Bunnell, David B.; Rogers, Mark W.; Beard, T. Douglas; Taylor, William W.

    2015-01-01

    The relationship between autotrophic activity and freshwater fish populations is an important consideration for ecologists describing trophic structure in aquatic communities, fisheries managers tasked with increasing sustainable fisheries development, and fish farmers seeking to maximize production. Previous studies of the empirical relationships of autotrophic activity and freshwater fish yield have found positive relationships but were limited by small sample sizes, small geographic scopes, and the inability to compare patterns among many types of measurement techniques. Individual studies and reviews have also lacked consistent consideration of regional climate factors which may inform relationships between fisheries and autotrophic activity. We compiled data from over 700 freshwater systems worldwide and used meta-analysis and linear models to develop a comprehensive global synthesis between multiple metrics of autotrophic activity, fisheries, and climate indicators. Our results demonstrate that multiple metrics of fish (i.e., catch per unit effort, yield, and production) increase with autotrophic activity across a variety of fisheries. At the global scale additional variation in this positive relationship can be ascribed to regional climate differences (i.e., temperature and precipitation) across systems. Our results provide a method and proof-of-concept for assessing inland fisheries production at the global scale, where current estimates are highly uncertain, and may therefore inform the continued sustainable use of global inland fishery resources.

  12. Key Contributors to Variations in Fish Mercury Within and Among Freshwater Reservoirs in Oklahoma, USA

    Science.gov (United States)

    Dong, Zhao; Lynch, Robert A.; Schaider, Laurel A.

    2017-01-01

    Elevated fish mercury (Hg) concentrations in freshwater ecosystems worldwide are a significant human and ecological health concern. Mercury bioaccumulation and biomagnification in lakes and reservoirs are controlled by numerous biogeochemical and ecological factors, contributing to variability in fish Hg concentrations both within and among systems. We measured total mercury concentrations ([THg]) and stable isotopes (δ15N, δ13C) in over 30 fish species in two connected subtropical freshwater reservoirs (Grand Lake and Lake Hudson, Oklahoma, USA), their tributaries, and local farm ponds, all of which are potentially impacted by nearby atmospheric Hg sources. We also conducted an inter-system analysis among 61 reservoirs in Oklahoma to explore biological, chemical and physical factors associated with fish [THg] across systems. We found that [THg] for most species in Grand Lake and Lake Hudson were relatively low compared to other reservoirs in Oklahoma. There were significant spatial variations in many species within and between Grand Lake and Lake Hudson, even after accounting for length and/or trophic position (based on δ15N). Fish in local farm ponds, commonly used in the agricultural regions for raising game fish, had 2–17 times higher [THg] than fish of similar length in nearby reservoirs. The inter-system analysis revealed that pH, water color, rainfall, and nutrients are the best predictors of fish [THg] across systems. Our results provide insight into the key factors associated with fish [THg] variations both within and across systems, and may be useful for exposure assessment and for identifying sites and water bodies prone to high fish [THg] as monitoring priorities. PMID:26729635

  13. A simple web-based tool to compare freshwater fish data collected using AFS standard methods

    Science.gov (United States)

    Bonar, Scott A.; Mercado-Silva, Norman; Rahr, Matt; Torrey, Yuta T.; Cate, Averill

    2016-01-01

    The American Fisheries Society (AFS) recently published Standard Methods for Sampling North American Freshwater Fishes. Enlisting the expertise of 284 scientists from 107 organizations throughout Canada, Mexico, and the United States, this text was developed to facilitate comparisons of fish data across regions or time. Here we describe a user-friendly web tool that automates among-sample comparisons in individual fish condition, population length-frequency distributions, and catch per unit effort (CPUE) data collected using AFS standard methods. Currently, the web tool (1) provides instantaneous summaries of almost 4,000 data sets of condition, length frequency, and CPUE of common freshwater fishes collected using standard gears in 43 states and provinces; (2) is easily appended with new standardized field data to update subsequent queries and summaries; (3) compares fish data from a particular water body with continent, ecoregion, and state data summaries; and (4) provides additional information about AFS standard fish sampling including benefits, ongoing validation studies, and opportunities to comment on specific methods. The web tool—programmed in a PHP-based Drupal framework—was supported by several AFS Sections, agencies, and universities and is freely available from the AFS website and fisheriesstandardsampling.org. With widespread use, the online tool could become an important resource for fisheries biologists.

  14. Use of seasonal freshwater wetlands by fishes in a temperate river floodplain

    Science.gov (United States)

    Henning, Julie A.; Gresswell, Robert E.; Fleming, Ian A.

    2007-01-01

    This study examined the use of freshwater wetland restoration and enhancement projects (i.e. non-estuarine wetlands subject to seasonal drying) by fish populations. To quantify fish use of freshwater emergent wetlands and assess the effect of wetland enhancement (i.e. addition of water control structures), two enhanced and two unenhanced emergent wetlands were compared, as well as two oxbow habitats within the Chehalis River floodplain. Eighteen fish species were captured using fyke nets and emigrant traps from January to the beginning of June, with the most abundant being three-spined stickleback Gasterosteus aculeatus and Olympic mudminnow Novumbra hubbsi. Coho salmon Oncorhynchus kisutch was the dominant salmonid at all sites. Enhanced wetlands, with their extended hydroperiods, had significantly higher abundances of yearling coho salmon than unenhanced wetlands. Both enhanced and unenhanced emergent wetlands yielded higher abundances of non-game native fishes than oxbow habitats. Oxbow habitats, however, were dominated by coho salmon. Fish survival in the wetland habitats was dependent on emigration to the river before dissolved oxygen concentrations decreased and wetlands became isolated and stranding occurred. This study suggests that wetland enhancement projects with an outlet to the river channel appear to provide fishes with important temporary habitats if they have the opportunity to leave the wetland as dissolved oxygen levels deteriorate.

  15. Assessing Potential Conservation and Restoration Areas of Freshwater Fish Fauna in the Indian River Basins

    Science.gov (United States)

    Bhatt, Jay P.; Manish, Kumar; Mehta, Rajender; Pandit, Maharaj K.

    2016-05-01

    Conservation efforts globally are skewed toward terrestrial ecosystems. To date, conservation of aquatic ecosystems, in particular fish fauna, is largely neglected. We provide a country-wide assessment of Indian river ecosystems in order to identify and prioritize areas for protection and restoration of freshwater fish fauna. Using various biodiversity and anthropogenic attributes, coupled with tools of ecological modeling, we delineated areas for fish fauna conservation and restoration in the 20 major river basins of India. To do this, we used prioritization analyses and reserve selection algorithms to derive conservation value index (CVI) and vulnerability index (VI) of the river basins. CVI was estimated using endemicity, rarity, conservation value, and taxonomic singularity, while VI was estimated using a disturbance index derived from percent geographic area of the basin under human settlements, human population density, predominant land use, and total number of exotic fish species in each basin. The two indices, CVI and VI, were converted into geo-referenced maps, and each map was super-imposed onto species richness and forest cover maps, respectively. After superimposition, areas with high CVI and low VI shade intensities were delineated for conservation, while areas with high CVI and high VI shade intensities were demarcated for restoration. In view of the importance of freshwater fish for human livelihoods and consumption, and ecosystems of India's rivers, we call for urgent attention to the conservation of their fish fauna along with restoration of their degraded habitats.

  16. Evaluating invasion risk for freshwater fishes in South Africa

    Directory of Open Access Journals (Sweden)

    Sean M. Marr

    2017-03-01

    Full Text Available Background: South Africa, as a signatory of the Convention on Biological Diversity, has an obligation to identify, prioritise and manage invasive species and their introduction pathways. However, this requires knowledge of the introduction pathways, factors influencing establishment success, invasive potential, current distributions and ecological impacts. Objectives: To evaluate the Fish Invasiveness Screening Kit (FISK to predict the invasion risk posed by fish species proposed for introduction into South Africa. Method: FISK assessments were compiled for species whose invasion status in South Africa was known. A Receiver operating characteristic (ROC analysis was conducted to calibrate the FISK for South Africa. The calibrated FISK was used to evaluate the risk that three species recently proposed for importation for aquaculture could become invasive in South Africa. Results: A FISK score of 14 was identified as the threshold to delineate between species that could become invasive in South Africa and those that are unlikely to become invasive. Of the three species evaluated, Silurus glanis had a high risk of becoming invasive in South Africa, Lates calcarifer was likely to be invasive and Oncorhynchus tshawytscha was unlikely to be invasive in South Africa. Conclusion: FISK was demonstrated to be a useful risk assessment tool to evaluate the invasion risk posed by species proposed for use in aquaculture. For the large number of fish imported for the pet trade, a rapid screening assessment to flag potentially high risk species was recommended prior to a full FISK assessment for flagged species.

  17. Richness and diversity of helminth communities in tropical freshwater fishes: Empirical evidence

    Science.gov (United States)

    Choudhury, A.; Dick, T.A.

    2000-01-01

    Aim: Published information on the richness and diversity of helminth parasite communities in tropical freshwater fishes is reviewed in response to expectations of species-rich parasite communities in tropical regions. Location: Areas covered include the tropics and some subtropical areas. In addition, the north temperate area of the nearctic zone is included for comparison. Methods: Data from 159 communities in 118 species of tropical freshwater fish, summarized from 46 published studies, were used for this review. Parasite community descriptors used in the analyses included component community richness and calculated mean species richness. Data from 130 communities in 47 species of nearctic north temperate freshwater fish were summarized from 31 studies and used for comparison. Results: The component helminth communities of many tropical freshwater fish are species-poor, and considerable proportions of fish from certain parts of the tropics, e.g. West African drainages, are uninfected or lightly infected. Mean helminth species richness was low and equaled or exceeded 2.0 in only 22 of 114 communities. No single group of helminths was identified as a dominant component of the fauna and species composition was variable among and within broader geographical areas. The richest enteric helminth assemblages were found in mochokid and clariid catfish with a mixed carnivorous diet, whereas algal feeders, herbivores and detritivores generally had species-poor gut helminth communities. Comparisons indicated that certain areas in the north temperate region had higher helminth species richness in fishes than areas in the tropics. Main conclusions: Expectations of high species richness in helminth communities of tropical freshwater fishes are not fulfilled by the data. Direct comparisons of infracommunities and component communities in host species across widely separated phylogenetic and geographical lines are inappropriate. Examination of latitudinal differences in richness

  18. Characterization and virulence potential of phenotypically diverse Aeromonas veronii isolates recovered from moribund freshwater ornamental fishes of Kerala, India.

    Science.gov (United States)

    Sreedharan, Krishnan; Philip, Rosamma; Singh, Isaac Sarojani Bright

    2013-01-01

    In the present study, we investigated the involvement of Aeromonas spp. in eliciting disease outbreaks in freshwater ornamental fishes across the state of Kerala, India. We investigated three incidences of disease, in which the moribund fishes exhibited clinical signs such as haemorrhagic septicemia (in gouramy, Trichogaster sp.), dropsy (in Oscar, Astronotus ocellatus) and tail rot/fin rot (in gold fish, Carassius carassius). Pure cultures (n = 20 from each fish; 60 in total) of Aeromonas spp. were recovered from the abdominal fluid as well as from internal organs of affected fishes, although they could not be identified to species level because of the variations in their phenotypic characters. The molecular fingerprinting of the isolates using Enterobacterial Repetitive Intergenic Consensus PCR proved the genetic diversity of the isolates from the three sites. The phylogenetic trees constructed using concatenated sequences (using 16S rRNA, gyrA, gyrB and rpoD genes) indicated that they were related to Aeromonas veronii. They exhibited marked cytotoxic and haemolytic activity, which were responsible for the pathogenic potential of the isolates. The isolates possessed multiple virulence genes such as enterotoxins (act and alt), haemolytic toxins (aerA and hlyA), genes involved in type III secretion system (ascV, aexT and ascF-ascG), glycerophospholipid-cholesterol acyltransferase (gcat) and a type IV pilus (tapA) gene, as determined by PCR. Virulence of representative isolates to goldfish was also tested, and we found LD(50) values of 10(4.07)-10(5.35) cfu/fish. Furthermore, the organisms could be recovered as pure cultures from the lesions as well as from the internal organs.

  19. Prevalence and antimicrobial resistance of Salmonella spp. in raw retail frozen imported freshwater fish to Eastern Province of Saudi Arabia

    Directory of Open Access Journals (Sweden)

    Nasreldin Elhadi

    2014-03-01

    Conclusions: The obtained results of this study shows that these raw retail imported frozen freshwater fish are contaminated with potentially pathogenic Salmonella spp. And the study recommend and suggest that there is a need for adequate consumer measures.

  20. Omega-3 fatty acids in baked freshwater fish from south of Brazil.

    Science.gov (United States)

    Andrade, A D; Visentainer, J V; Matsushita, M; de Souza, N E

    1997-03-01

    Lipid and fatty acid levels in the edible flesh of 17 baked freshwater fish from Brazil's southern region were determined. Analyses of fatty acids methyl esters were performed by gas chromatography. Palmitic acid (C16:0) was the predominant saturated fatty acid, accouting for 50-70% of total saturated acids. Linoleic acid (C18:2 omega 6), linolenic acid (C18:3 omega 3), and docosahexaenoic acid (C22:6 omega 3) were the predominant polyunsatured fatty acids (PUFA). The data revealed that species such as barbado, corvina, pintado, and truta were good sources of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), and that most freshwater fish examined were good sources of PUFA-omega 3.

  1. Comparative toxicity of methanol and N,N-dimethylformamide to freshwater fish and invertebrates

    Energy Technology Data Exchange (ETDEWEB)

    Poirier, S.H.; Knuth, M.L.; Anderson-Buchou, C.D.; Brooke, L.T.; Lima, A.R.; Shubat, P.J.

    1986-10-01

    The organic solvents methanol and N,N-dimethylformamide (DMF) are used widely as industrial solvents. Although some toxicity data appear in the literature for methanol and DMF, there have been few studies which have been flow-through tests for a standard 48- or 96-h exposure period with measured toxicant concentrations. In this study, 96-h flow-through acute toxicity tests with methanol and DMF were conducted with three species of freshwater fish - rainbow trout (Salmo gairdneri), bluegill (Lepomis macrochirus) and fathead minnow (Pimephales promelas). Static acute toxicity tests (48 h) were conducted with DMF and two species of freshwater invertebrates - a midge (Paratanytarsus parthenogeneticus) and a daphnid (Daphnia magna). Median lethal (LC50) and median effect (EC50) concentrations for 96-h exposures were determined for fish and 48-h EC50's were determined for invertebrates.

  2. Length-weight relationships for six freshwater fish species in Iran

    Institute of Scientific and Technical Information of China (English)

    M. S. HEYDARNEJAD

    2009-01-01

    The aim of this study is to report the length-weight relationship parameters (a and b) for some economically important fish species from Iranian freshwaters. The length-weight relationships (LWR) are calculated for six freshwater fish species collected during 2006 and 2007 in Iran. The values of the exponent b in the LWR (W=aLb) vary between 2.985 and 3.543. The LWR with high correlation coefficient (r2) is significant for all the species. These parameters are of great importance to evaluate the relative condition of populations, biology, species management and their fisheries and stock assessment. The application of the length-weight relationships presented here should be limited to the observed length ranges.

  3. Variation in the transfer of radionuclide to freshwater fish: phylogeny or feeding strategy?

    OpenAIRE

    Yankovich, T.; Beresford, N. A.; Wood, M.; Willey, N.

    2011-01-01

    For both terrestrial vascular plants and marine organisms if has been demonstrated the differences in radionuclide transfer between species can be related to their evolutionary history or phylogeny. Relationships between phylogeny and radionuclide transfer offer a potential approach to help to derive best estimate values if data for a given species-radionuclide are not available. In this paper we describe the analyses of data for radionuclide transfer to freshwater fish from a data base re...

  4. Natural fragmentation in river networks as a driver of speciation for freshwater fishes

    OpenAIRE

    Dias, Murilo S.; Cornu, Jean-François; Oberdorff, Thierry; Lasso, Carlos A.; Tedesco, Pablo A.

    2013-01-01

    Although habitat fragmentation fosters extinctions, it also increases the probability of speciation by promoting and maintaining divergence among isolated populations. Here we test for the effects of two isolation factors that may reduce population dispersal within river networks as potential drivers of freshwater fish speciation: 1) the position of subdrainages along the longitudinal river gradient, and 2) the level of fragmentation within subdrainages caused by natural waterfalls. The occur...

  5. Hidalgo Fishes: Dataset on freshwater fishes of Hidalgo state (Mexico) in the MZNA fish collection of the University of Navarra (Spain)

    Science.gov (United States)

    Galicia, David; Pulido-Flores, Griselda; Miranda, Rafael; Monks, Scott; Amezcua-Martínez, Ana; Imas-Lecumberri, María; Chaves-Illana, Angel; Ariño, Arturo H.

    2014-01-01

    Abstract The state of Hidalgo (Mexico) is an important region from the point of view of biodiversity. However, there exists a significant gap in accessible knowledge about species diversity and distribution, especially regarding to freshwater ecosystems. This dataset comprises the sampling records of two projects developed in Hidalgo between 2007 and 2009 about the freshwater fish communities of Tecocomulco lake and rivers belonging to the Metztitlán Canyon Biosphere Reserve. It contains the taxonomic identity (species level) and basic biometric data (total length and weight) as well as date of collection and coordinates of more than 9000 specimens. This dataset is the primary result of the first and unrepeated exhaustive freshwater fish’s survey of Metztitlán Canyon Biosphere Reserve and Tecocomulco lake. It incorporates seven more species to the regional fish fauna, and new exclusive biometric data of ten species. This dataset can be used by studies dealing with, among other interests, North American freshwater fish diversity (species richness, distribution patterns) and biometric analyses, useful for the management and conservation of these areas. The complete dataset is also provided in Darwin Core Archive format. PMID:24843267

  6. A new freshwater biodiversity indicator based on fish community assemblages.

    Directory of Open Access Journals (Sweden)

    Joanne Clavel

    Full Text Available Biodiversity has reached a critical state. In this context, stakeholders need indicators that both provide a synthetic view of the state of biodiversity and can be used as communication tools. Using river fishes as model, we developed community indicators that aim at integrating various components of biodiversity including interactions between species and ultimately the processes influencing ecosystem functions. We developed indices at the species level based on (i the concept of specialization directly linked to the niche theory and (ii the concept of originality measuring the overall degree of differences between a species and all other species in the same clade. Five major types of originality indices, based on phylogeny, habitat-linked and diet-linked morphology, life history traits, and ecological niche were analyzed. In a second step, we tested the relationship between all biodiversity indices and land use as a proxy of human pressures. Fish communities showed no significant temporal trend for most of these indices, but both originality indices based on diet- and habitat- linked morphology showed a significant increase through time. From a spatial point of view, all indices clearly singled out Corsica Island as having higher average originality and specialization. Finally, we observed that the originality index based on niche traits might be used as an informative biodiversity indicator because we showed it is sensitive to different land use classes along a landscape artificialization gradient. Moreover, its response remained unchanged over two other land use classifications at the global scale and also at the regional scale.

  7. A new freshwater biodiversity indicator based on fish community assemblages.

    Science.gov (United States)

    Clavel, Joanne; Poulet, Nicolas; Porcher, Emmanuelle; Blanchet, Simon; Grenouillet, Gaël; Pavoine, Sandrine; Biton, Anne; Seon-Massin, Nirmala; Argillier, Christine; Daufresne, Martin; Teillac-Deschamps, Pauline; Julliard, Romain

    2013-01-01

    Biodiversity has reached a critical state. In this context, stakeholders need indicators that both provide a synthetic view of the state of biodiversity and can be used as communication tools. Using river fishes as model, we developed community indicators that aim at integrating various components of biodiversity including interactions between species and ultimately the processes influencing ecosystem functions. We developed indices at the species level based on (i) the concept of specialization directly linked to the niche theory and (ii) the concept of originality measuring the overall degree of differences between a species and all other species in the same clade. Five major types of originality indices, based on phylogeny, habitat-linked and diet-linked morphology, life history traits, and ecological niche were analyzed. In a second step, we tested the relationship between all biodiversity indices and land use as a proxy of human pressures. Fish communities showed no significant temporal trend for most of these indices, but both originality indices based on diet- and habitat- linked morphology showed a significant increase through time. From a spatial point of view, all indices clearly singled out Corsica Island as having higher average originality and specialization. Finally, we observed that the originality index based on niche traits might be used as an informative biodiversity indicator because we showed it is sensitive to different land use classes along a landscape artificialization gradient. Moreover, its response remained unchanged over two other land use classifications at the global scale and also at the regional scale.

  8. Reproductive strategies and genetic variability in tropical freshwater fish

    Directory of Open Access Journals (Sweden)

    Maria Dolores Peres Lassala

    2007-01-01

    Full Text Available We estimated the genetic variability of nine fish species from the Brazilian upper Paraná River floodplain (Astyanax altiparanae, Hoplias malabaricus, Leporinus lacustris, Loricariichthys platymetopon, Parauchenipterus galeatus, Pimelodus maculatus, Rhaphiodon vulpinus, Roeboides paranensis and Serrasalmus marginatus based on data for 36 putative allozyme loci obtained using corn starch gel electrophoresis of 13 enzymatic systems: aspartate aminotransferase (EC 2.6.1.1, acid phosphatase (EC 3.1.3.2, esterase (EC 3.1.1.1, glycerol-3-phosphate dehydrogenase (EC 1.1.1.8, glucose-6-phosphate dehydrogenase (EC 1.1.1.49, glucose-6-phosphate isomerase (EC 5.3.1.9, Iditol dehydrogenase (EC 1.1.1.14, isocitrate dehydrogenase - NADP+ (EC 1.1.1.42, L-lactate dehydrogenase (EC 1.1.1.27, malate dehydrogenase (EC 1.1.1.37, malate dehydrogenase-NADP+ (EC 1.1.1.40, phosphoglucomutase (EC 5.4.2.2 and superoxide dismutase, (EC 1.15.1.1. The mean expected heterozygosity varied from zero to 0.147. When data from the literature for 75 species of tropical fish were added to the nine species of this study, the heterozygosity values differed significantly among the groups of different reproductive strategies. The highest mean heterozygosity was for the non-migratory without parental care, followed by the long-distance migratory, and the lowest mean was for the non-migratory with parental care or internal fecundation.

  9. Implications of stunting on morphology of freshwater fishes

    Science.gov (United States)

    Chizinski, C.J.; Pope, K.L.; Wilde, G.R.; Strauss, R.E.

    2010-01-01

    The purpose of this study was to assess morphological differences between stunted and non-stunted white perch Morone americana and green sunfish Lepomis cyanellus. Few female M. americana were captured; thus, morphological differences between adult males and juveniles were assessed for M. americana. Similarly, few immature (juvenile) L. cyanellus were captured for the stunted morphotype; thus, male and female morphological differences were assessed for L. cyanellus. Features of the head tended to be relatively larger in stunted fish of both species, whereas the mid-body tended to be relatively larger in non-stunted M. americana, but not in non-stunted L. cyanellus. Adult and juvenile morphology overlapped considerably in non-stunted M. americana, but there was a clear distinction between adult and juvenile morphology of stunted M. americana. There was little sexual dimorphism in shape in stunted L. cyanellus, whereas sexual dimorphism was evident in non-stunted L. cyanellus. It appears that selective forces imposed by predation and food limitation may contribute to morphological diversification between stunted and non-stunted fishes. ?? 2010 The Authors. Journal compilation ?? 2010 The Fisheries Society of the British Isles.

  10. Levels, temporal trends, and tissue distribution of perfluorinated surfactants in freshwater fish from Asian countries.

    Science.gov (United States)

    Murakami, Michio; Adachi, Nozomi; Saha, Mahua; Morita, Chiaki; Takada, Hideshige

    2011-11-01

    Perfluorinated surfactants (PFSs) in Asian freshwater fish species were analyzed to investigate tissue distribution, temporal trends, extent of pollution, and level of PFS exposure through food intake. Freshwater fish species, namely carp, snakehead, and catfish, were collected in Japan, Vietnam, India, Malaysia, and Thailand, and 10 PFSs, including perfluorooctanesulfonate (PFOS) and perfluorooctanoate, were analyzed by liquid chromatography-tandem mass spectrometry. PFSs in carp in Tokyo were more concentrated in kidneys (Σ10 PFSs = 257 ± 95 ng/g wet weight [ww]) and livers (119 ± 36 ng/g ww) than in ovaries (43 ± 2 ng/g ww) and muscles (24 ± 17 ng/g ww). Concentrations of PFOS and its precursor, perfluorooctane sulfonamide, in livers of carp and in waters in Tokyo showed a dramatic decrease during the last decade, probably because of 3 M's phasing-out of the manufacture of perfluorooctanesulfonyl-fluoride-based products in 2000. In contrast, continuing contamination by long-chain perfluorocarboxylates (PFCAs) with ≥ 9 fluorinated carbons was seen in multiple media, suggesting that these compounds continue to be emitted. PFS concentrations in freshwater fish species in tropical Asian countries were generally lower than those in developed countries, such as Japan, e.g., for PFOS in muscle, Vietnam Asian developing countries.

  11. Molecular Phylogenetics of Centrocestus formosanus (Digenea: Heterophyidae) Originated from Freshwater Fish from Chiang Mai Province, Thailand

    Science.gov (United States)

    Wongsawad, Chalobol; Wongsawad, Pheravut; Sukontason, Kom; Maneepitaksanti, Worawit; Nantarat, Nattawadee

    2017-01-01

    This study aimed to investigate the morphology and reconstruct the phylogenetic relationships of Centrocestus formosanus originating from 5 species of freshwater fish, i.e., Esomus metallicus, Puntius brevis, Anabas testudineus, Parambassis siamensis, and Carassius auratus, in Chiang Mai province, Thailand. Sequence-related amplified polymorphism (SRAP) and phylogeny based on internal transcribed spacer 2 (ITS2) and mitochondrial cytochrome c oxidase subunit 1 (CO1) were performed. The results showed similar morphologies of adult C. formosanus from day 5 after infection in chicks. C. formosanus originated from 4 species of freshwater fish had the same number of circumoral spines on the oral sucker, except for those from C. auratus which revealed 34 circumoral spines. The phylogenetic tree obtained from SRAP profile and the combination of ITS2 and CO1 sequence showed similar results that were correlated with the number of circumoral spines in adult worms. Genetic variability of C. formosanus also occurred in different species of freshwater fish hosts. However, more details of adult worm morphologies and more sensitive genetic markers are needed to confirm the species validity of C. formosanus with 34 circumoral spines originating from C. auratus in the future. PMID:28285504

  12. Molecular Phylogenetics of Centrocestus formosanus (Digenea: Heterophyidae) Originated from Freshwater Fish from Chiang Mai Province, Thailand.

    Science.gov (United States)

    Wongsawad, Chalobol; Wongsawad, Pheravut; Sukontason, Kom; Maneepitaksanti, Worawit; Nantarat, Nattawadee

    2017-02-01

    This study aimed to investigate the morphology and reconstruct the phylogenetic relationships of Centrocestus formosanus originating from 5 species of freshwater fish, i.e., Esomus metallicus, Puntius brevis, Anabas testudineus, Parambassis siamensis, and Carassius auratus, in Chiang Mai province, Thailand. Sequence-related amplified polymorphism (SRAP) and phylogeny based on internal transcribed spacer 2 (ITS2) and mitochondrial cytochrome c oxidase subunit 1 (CO1) were performed. The results showed similar morphologies of adult C. formosanus from day 5 after infection in chicks. C. formosanus originated from 4 species of freshwater fish had the same number of circumoral spines on the oral sucker, except for those from C. auratus which revealed 34 circumoral spines. The phylogenetic tree obtained from SRAP profile and the combination of ITS2 and CO1 sequence showed similar results that were correlated with the number of circumoral spines in adult worms. Genetic variability of C. formosanus also occurred in different species of freshwater fish hosts. However, more details of adult worm morphologies and more sensitive genetic markers are needed to confirm the species validity of C. formosanus with 34 circumoral spines originating from C. auratus in the future.

  13. The interaction of fish trypanosome culture forms with some lectins.

    Science.gov (United States)

    Zajícek, P; Pecková, H

    1990-01-01

    The interactions of fish trypanosome culture forms with 11 purified lectins were compared using the agglutination test in microwell plates. Altogether, ten stocks of ten different freshwater fish species were examined. Three basic types of cell-lectin interactions were observed on the microscopical level. The strong agglutination of all stocks regardless their original host was found in the presence of Con A, PSA, RCA60, and RCA120, which implies the presence of relatively high amounts of sugar residues of D-mannose and D-galactose in the surface of culture forms of these parasites. Weak agglutinations of some stocks were observed in the presence of LCA, PNA, SBA, and WGA lectins, but their low intensity makes them not sufficiently reliable for stock characterization. The lectins UEA I, HPA, and PHA caused no agglutination. In conclusion, in case of unequivocal results no remarkable differences in the interactions of various stocks of trypanosomes culture forms with used lectins were observed. These results imply the high degree of similarity of their main cell surface saccharide structures.

  14. Biodiversity of freshwater fish of a protected river in India: comparison with unprotected habitat

    Directory of Open Access Journals (Sweden)

    Uttam Kumar Sarkar

    2013-03-01

    Full Text Available In India, freshwater environments are experiencing serious threats to biodiversity, and there is an urgent priority for the search of alternative techniques to promote fish biodiversity conservation and management. With this aim, the present study was undertaken to assess the fish biodiversity within and outside a river protected area, and to evaluate whether the protected river area provides some benefits to riverine fish biodiversity. To assess this, the pattern of freshwater fish diversity was studied in river Gerua, along with some physicochemical conditions, from April 2000 to March 2004. For this, a comparison was made between a 15km stretch of a protected area (Katerniaghat Wildlife Sanctuary, and an unprotected one 85km downstream. In each site some physicochemical conditions were obtained, and fish were caught by normal gears and the diversity per site described. Our results showed that water temperature resulted warmest during the pre-monsoon season (25ºC and low during the winter (14-15ºC; turbidity considerably varied by season. In the protected area, a total of 87 species belonging to eight orders, 22 families and 52 genera were collected; while a maximum of 59 species belonging to six orders, 20 families and 42 genera were recorded from the unprotected areas. Cyprinids were found to be the most dominant genera and Salmostoma bacaila was the most numerous species in the sanctuary area. Other numerous species were Eutropiichthys vacha, Notopterus notopterus, Clupisoma garua and Bagarius bagarius. The results indicated more species, greater abundances, larger individuals, and higher number of endangered fishes within the sanctuary area when compared to the unprotected area. Analysis on the mean abundance of endangered and vulnerable species for the evaluated areas in the sanctuary versus unprotected ones indicated significant differences in fish abundance (p<0.05. These results showed that this riverine protected area could be

  15. Reproductive biology of freshwater fishes from the Venezuelan floodplains.

    Science.gov (United States)

    Guerrero, H Y; Cardillo, E; Poleo, G; Marcano, D

    2009-03-01

    This review describes the endocrine changes that occur during the annual reproductive cycle of Pygocentrus cariba, Pimelodus blochii, and Oxydoras sifontesi and their relationships with the environmental characteristics of Venezuelan floodplains. Most reproductive studies of teleosts have focused on changes that occur during annual cycles in temperate species but, in tropical fish, this has been examined less frequently. P. cariba, P. blochii, and O. sifontesi are seasonal breeders widely distributed along the Orinoco River. Under natural conditions they have an annual gonadal cycle closely related to changes in the annual hydrology cycle of the Orinoco River which defines two seasons on the floodplain: inundation and isolation. The reproductive cycle of these species seems to be controlled by cues from the external environment. Relevant data about gonadal maturation, for example gonadosomatic index and sexual hormones secretion, are contrasted. The role of catecholamines in neuroendocrine control of the reproductive axis is also considered in this work.

  16. Characterization of fish assemblages and population structure of freshwater fish in two Tunisian reservoirs: implications for fishery management.

    Science.gov (United States)

    Mili, Sami; Ennouri, Rym; Dhib, Amel; Laouar, Houcine; Missaoui, Hechmi; Aleya, Lotfi

    2016-06-01

    To monitor and assess the state of Tunisian freshwater fisheries, two surveys were undertaken at Ghezala and Lahjar reservoirs. Samples were taken in April and May 2013, a period when the fish catchability is high. The selected reservoirs have different surface areas and bathymetries. Using multi-mesh gill nets (EN 14575 amended) designed for sampling fish in lakes, standard fishing methods were applied to estimate species composition, abundance, biomass, and size distribution. Four species were caught in the two reservoirs: barbel, mullet, pike-perch, and roach. Fish abundance showed significant change according to sampling sites, depth strata, and the different mesh sizes used. From the reservoir to the tributary, it was concluded that fish biomass distribution was governed by depth and was most abundant in the upper water layers. Species size distribution differed significantly between the two reservoirs, exceeding the length at first maturity. Species composition and abundance were greater in Lahjar reservoir than in Ghezala. Both reservoirs require support actions to improve fish productivity.

  17. The influence of external subsidies on diet, growth and Hg concentrations of freshwater sport fish: implications for management and fish consumption advisories

    Science.gov (United States)

    Lepak, J.M.; Hooten, M.B.; Johnson, B.M.

    2012-01-01

    Mercury (Hg) contamination in sport fish is a global problem. In freshwater systems, food web structure, sport fish sex, size, diet and growth rates influence Hg bioaccumulation. Fish stocking is a common management practice worldwide that can introduce external energy and contaminants into freshwater systems. Thus, stocking can alter many of the factors that influence Hg concentrations in sport fish. Here we evaluated the influence of external subsidies, in the form of hatchery-raised rainbow trout Oncorhynchus mykiss on walleye Sander vitreus diet, growth and Hg concentrations in two freshwater systems. Stocking differentially influenced male and female walleye diets and growth, producing a counterintuitive size-contamination relationship. Modeling indicated that walleye growth rate and diet were important explanatory variables when predicting Hg concentrations. Thus, hatchery contributions to freshwater systems in the form of energy and contaminants can influence diet, growth and Hg concentrations in sport fish. Given the extensive scale of fish stocking, and the known health risks associated with Hg contamination, this represents a significant issue for managers monitoring and manipulating freshwater food web structures, and policy makers attempting to develop fish consumption advisories to protect human health in stocked systems.

  18. Calibration of FISK, an invasiveness screening tool for nonnative freshwater fishes.

    Science.gov (United States)

    Copp, Gordon H; Vilizzi, Lorenzo; Mumford, John; Fenwick, Gemma V; Godard, Michael J; Gozlan, Rodolphe E

    2009-03-01

    Adapted from the weed risk assessment (WRA) of Pheloung, Williams, and Halloy, the fish invasiveness scoring kit (FISK) was proposed as a screening tool for freshwater fishes. This article describes improvements to FISK, in particular the incorporation of confidence (certainty/uncertainty) ranking of the assessors' responses, and reports on the calibration of the score system, specifically: determination of most appropriate score thresholds for classifying nonnative species into low-, medium-, and high-risk categories, assessment of the patterns of assessors' confidences in their responses in the FISK assessments. Using receiver operating characteristic (ROC) curves, FISK was demonstrated to distinguish accurately (and with statistical confidence) between potentially invasive and noninvasive species of nonnative fishes, with the statistically appropriate threshold score for high-risk species scores being >/=19. Within the group of species classed as high risk using this new threshold, a "higher risk" category could be visually identified, at present consisting of two species (topmouth gudgeon Pseudorasbora parva and gibel carp Carassius gibelio). FISK represents a useful and viable tool to aid decision- and policymakers in assessing and classifying freshwater fishes according to their potential invasiveness.

  19. Diversity and Distribution of Freshwater Fishes in Aceh Water, Northern-Sumatra,Indonesia

    Directory of Open Access Journals (Sweden)

    M.N. Siti Azizah

    2009-01-01

    Full Text Available The objective of the present study was to evaluate the diversity of freshwater fish and its distribution and to establish an inventory of the freshwater fish fauna in Aceh water. Sampling was done in five regions of NAD at 17 sites. Explorative research was conducted from January to June 2008 by investigating rivers based on information by local residents. Sampling was carried out in both lotic and lentic ecosystems. A total of 711 fishes belonging to 114 species, 69 genera, 41 families and 12 orders. Five families were distributed widely and observed in all the five regions i.e., Anguillidae, Clariidae, Cyprinidae, Anabantidae and Channidae. Sixteen families were found in only a single site. The diversity index of fishes in Aceh water ranged from 1.31 to 3.41 with an average of 2.17 indicating moderate values. The highest diversity was found in Lembang River of Aceh Selatan, while regionally, the North and south regions were higher but not significantly different from the West region. Highest similarity was found between Simpang dam and Sibreh irrigation canal of Sibreh. The similarity index between West and North region were relatively higher compared to other regional comparisons.

  20. Literature review of the concentration ratios of selected radionuclides in freshwater and marine fish

    Energy Technology Data Exchange (ETDEWEB)

    Poston, T.M.; Klopfer, D.C.

    1986-09-01

    Concentration ratios (CR's) used for modeling the uptake and food chain transport of radionuclides in fish have usually been conservative; that is, at the high end of reported values. This practice ensures that the dose to the consumer of contaminated fish will not be underestimated. In many models, however, conservative values have been used for all variables that have any uncertainty associated with them. As a result the dose to the consumer is overestimated. Realistic CR values need to be developed to establish model parameters that will accurately reflect tissue burdens in fish and resulting dose rates to consumers. This report reviews and summarizes published literature on the uptake and distribution of stable and radioactive isotopes of 26 elements. Based on this review, we have made recommendations on CR values to be used for modeling the accumulation of radionuclides in fish. Our recommendations are compared with CR values reported in other publications. A generic discussion of abiotic and biotic factors that influence CR values is provided so that CR values may be adjusted based on site-specific characteristics of the fishes habitat. Recommended CR values for freshwater fish and for marine fish are listed. Although this report emphasizes radionuclides, it is applicable to stable elements as well.

  1. Culture of Freshwater Prawns (Macrobrachium Rosenbergii) Using Geothermal Waste Water

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, William C.

    1978-01-01

    The farming of freshwater prawns (Macrobrachium rosenbergii) in geothermal-heated water has been demonstrated to be feasible in a non-tropical climate. The husbandry of prawns is being done in two outdoor raceway ponds, 9.1 m by 2.5 m and 29 m by 3.5 m that are 1.2 m deep. The ponds are not shielded from the ambient climate which during the winter months has recorded air temperatures as low as -20oC. A selected brood stock is held in a small spawning building where larvae are hatched in artificial saltwater and reared to the post-larvae stage which makes the facility self-supporting. This project is providing a model for potential investors to utilize the low-temperature geothermal resources in the western United States for warm water aquaculture. Zooplankton, macroscopic crusteans, from a local euthrophic lake are being fed to the post-larvae and adult prawns in addition to prepared commercial dry pelleted foods to keep operational costs at a minimum. Initial measurements of growth and weight gains indicate the production of two crops of prawns per year at seven to the pond is possible. No work on intensive culture has been done. Plans to enlarge the facility and do work on developing intensive culture are being considered.

  2. Selenium: Mercury molar ratios in freshwater fish in the Columbia River Basin: Potential applications for specific fish consumption advisories

    Science.gov (United States)

    Cusack, Leanne K.; Eagles-Smith, Collin A.; Harding, Anna K.; Kile, Molly; Stone, Dave

    2017-01-01

    Fish provide a valuable source of beneficial nutrients and are an excellent source of low fat protein. However, fish are also the primary source of methylmercury exposure in humans. Selenium often co-occurs with mercury and there is some evidence that selenium can protect against mercury toxicity yet States issue fish consumption advisories based solely on the risks that methylmercury pose to human health. Recently, it has been suggested the selenium: mercury molar ratio be considered in risk management. In order for agencies to utilize the ratio to set consumption guidelines, it is important to evaluate the variability in selenium and mercury in different fish species. We examined 10 different freshwater fish species found within the Columbia River Basin in order to determine the inter- and intra-specific variability in the selenium: mercury molar ratios and the selenium health benefit values. We found significant variation in selenium: mercury molar ratios. The mean molar ratios for each species were all above 1:1, ranging from 3.42:1 in Walleye to 27.2:1 in Chinook salmon. There was a positive correlation between both mercury and selenium with length for each fish species apart from yellow perch and rainbow trout. All species had health benefit values greater than 2. We observed considerable variability in selenium: mercury molar ratios within fish species collected in the Columbia River Basin. Although incorporating selenium: mercury molar ratios into fish consumption holds the potential for refining advisories and assessing the risk of methylmercury exposure, the current understanding of how these ratios apply is insufficient, and further understanding of drivers of variability in the ratios is needed.

  3. Correlation between biochemical parameters and susceptibility of freshwater fish to malathion.

    Science.gov (United States)

    Li Shao-Non; Fan De-Fang

    1996-07-01

    Acute toxicity (96-h LC50) of malathion was tested using five species of freshwater fish, namely, topmouth gudgeon (Pseudorasbora parva), goldfish (Carassius auratus), nile tilapia (Tilapia nilotica), mosquitofish (Gambusia affinis), and rainbow trout (Salmo gairdneri). Correlation was found between susceptibility and biochemical parameters such as activity of brain acetylcholinesterase (AChE) and in vitro resistance of the enzyme to inhibition (IC50) of malaoxon (a major metabolite of malathion). The in vitro study also showed that malaoxon instead of malathion was the main inhibitor of AChE. Susceptibility to malathion was considerably changed as the fish was pretreated with piperonyl butoxide (PB, a P-450 inhibitor) and triphenyl phosphate (TPP, an inhibitor of carboxylesterase), respectively. Toxicity of malathion was significantly increased by TPP, but the responses of fish to PB were quite different among species. This suggested that both carboxylesterase and monooxygenase played an important role in susceptibility determination, and great variations existed among species in activity of monooxygenase.

  4. Discovering hidden biodiversity: The use of complementary monitoring of fish diet based on DNA barcoding in freshwater ecosystems

    DEFF Research Database (Denmark)

    Jo, Hyunbin; Ventura, Marc; Vidal, Nicolas

    2015-01-01

    Formicidae, Chrysomelidae and Torbidae and the freshwater Chironomidae. The haplotype occurrence per lake was negatively correlated with lake depth and transparency. Nearly all haplotypes were only found in one fish gut from a single lake. Our results indicate that DNA barcoding of fish diets is a useful...

  5. Ability of freshwater fish to extract oxygen at different hydrogen-ion concentrations

    Energy Technology Data Exchange (ETDEWEB)

    Wiebe, A.H.; McGavock, A.M.; Fuller, A.C.; Markus, H.C.

    1934-01-01

    Pruthi's observations on the stickleback at pH 3.1 have been confirmed for the stickleback as well as several other species of fresh-water fish. Pruthi's criticism of the work of Powers is invalid within the pH range to which the fish are acclimated. The initial oxygen has either no effect on the lethal oxygen or the effect is in the opposite direction from that suggested by Pruthi. Outside of the pH range normal to the species in question the lethal oxygen is dependent in a large measure on the initial oxygen. Several species of freshwater fish--largemouth blackbass, smallmouth blackbass, white crappie, yellow perch, rainbow trout, as well as the goldfish and green sunfish--have the ability to extract oxygen from the water at low oxygen tensions equally well over a fairly wide range of hydrogen-ion concentration. The bluegill has a somewhat narrower range of toleration. The two species of minnow--steel-colored and bluntnose--tolerate a markedly narrower range of difference in hydrogen-ion concentration as shown by the lethal oxygen. The ability of fish to extract oxygen from the water at low pressure depends more or less on the hydrogen-ion concentration of water. The results obtained in this investigation confirm the studies on pH tolerance of fish previously published. These results also confirm the observations that in highly alkaline water fish require a higher concentration of oxygen to survive.

  6. Effects of co-cultured fish and feed supplement on water chemistry characteristics of freshwater pearl mussel farming%不同混养鱼类和投喂方式对鱼蚌综合养殖水体化学特征的影响

    Institute of Scientific and Technical Information of China (English)

    戴杨鑫; 王岩; 唐金玉; 李由明

    2013-01-01

      选用草鱼(Ctenoparyngodon idellus)、银鲫(Carassius gibelio)、鲢(Hypopthalmichthys molitrix)、鳙(Aristichthys nobilis)作为本研究的混养鱼类,通过围隔实验检验了不同混养鱼类组合(草鱼+鲫+鲢+鳙或鲢+鳙)和配合饲料投喂方式(投喂或不投喂)对三角帆蚌(Hyriopsis cumingii)养殖水体化学特征的影响,实验为期155 d.结果表明,实验设计的混养鱼类组合可显著影响鱼蚌综合养殖水体的 Ca2+、总碱度(Alk)、总硬度(HT)和总磷(TP)水平;投喂配合饲料可显著影响 Ca2+、Alk、HT、氨氮(TAN)、TP 和化学耗氧量(CODMn).采用混养组合(草鱼+鲫+鲢+鳙)且投喂配合饲料的围隔内溶氧(DO)水平和透明度(SD)较低, Ca2+、HT、TN、TP、TAN 和 CODMn 水平较高;采用混养组合(鲢+鳙)且不投喂的围隔内 DO 和 SD 水平较高,而 Ca2+、HT、TN、TP、TAN 和 CODMn 水平较低.随养殖时间延长,各组围隔内 Ca2+水平下降, TN、TP、TAN 和 CODMn 水平升高.实验期间, DO 与 SD 水平呈正相关; DO 和 SD 与 TAN、TN、TP、Ca2+和 CODMn 水平呈负相关.因此,鱼蚌综合养殖中,控制 CODMn 和 TAN 浓度,维持 Ca2+稳定及较高的 DO 水平是水质管理的基本目标.%Integrated culture is widely used in freshwater pearl mussel (Hyriopsis cumingii) farming; however, water chemistry characteristics relating to H. cumingii farming are poorly understood. To assess the effects of co-cultured fish (grass carp, gibel carp, silver carp and bighead carp or silver carp and bighead carp) and formu-lated fish feed supplement (with or without feed supplement) on water chemistry characteristics, a 155-day field experiment was carried out in land-based enclosures. Four treatments including GGSB-F (co-cultured fish grass carp, gibel carp, silver carp and bighead carp were fed formulated feed), GGSB-NF (co-cultured fish grass carp, gibel carp, silver carp and bighead carp were not fed formulated feed), SB

  7. Trait-based prediction of extinction risk of small-bodied freshwater fishes.

    Science.gov (United States)

    Kopf, R Keller; Shaw, Casey; Humphries, Paul

    2017-06-01

    Small body size is generally correlated with r-selected life-history traits, including early maturation, short-generation times, and rapid growth rates, that result in high population turnover and a reduced risk of extinction. Unlike other classes of vertebrates, however, small freshwater fishes appear to have an equal or greater risk of extinction than large fishes. We explored whether particular traits explain the International Union for Conservation of Nature (IUCN) Red List conservation status of small-bodied freshwater fishes from 4 temperate river basins: Murray-Darling, Australia; Danube, Europe; Mississippi-Missouri, North America; and the Rio Grande, North America. Twenty-three ecological and life-history traits were collated for all 171 freshwater fishes of ≤120 mm total length. We used generalized linear mixed-effects models to assess which combination of the 23 traits best explained whether a species was threatened or not threatened. We used the best models to predict the probability of 29 unclassified species being listed as threatened. With and without controlling for phylogeny at the family level, small body size-among small-bodied species-was the most influential trait correlated with threatened species listings. The k-folds cross-validation demonstrated that body size and a random effect structure that included family predicted the threat status with an accuracy of 78% (SE 0.5). We identified 10 species likely to be threatened that are not listed as such on the IUCN Red List. Small body size is not a trait that provides universal resistance to extinction, particularly for vertebrates inhabiting environments affected by extreme habitat loss and fragmentation. We hypothesize that this is because small-bodied species have smaller home ranges, lower dispersal capabilities, and heightened ecological specialization relative to larger vertebrates. Trait data and further model development are needed to predict the IUCN conservation status of the over 11

  8. Colossal aggregations of giant alien freshwater fish as a potential biogeochemical hotspot.

    Science.gov (United States)

    Boulêtreau, Stéphanie; Cucherousset, Julien; Villéger, Sébastien; Masson, Rémi; Santoul, Frédéric

    2011-01-01

    The ubiquity and fascinating nature of animal aggregations are widely recognised. We report here consistent and previously undocumented occurences of aggregations of a giant alien freshwater fish, the Wels catfish (Silurus glanis). Aggregative groups were on average composed of 25 (± 10 SD, ranging from 15 to 44) adults with estimated average total biomass of 651 kg (386 - 1132) and biomass density of 23 kg m(-2) (14 - 40). Aggregations always occurred within the same location. No foraging, reproductive or anti-predator behaviour were observed during the aggregations. A mass-balance model estimated that these colossal aggregations of an alien species can locally release, through excretion only, up to 70 mg P m(-2) h(-1) and 400 mg N m(-2) h(-1), potentially representing the highest biogeochemical hotspots reported in freshwater ecosystems and another unexpected ecological effect of alien species.

  9. Colossal aggregations of giant alien freshwater fish as a potential biogeochemical hotspot.

    Directory of Open Access Journals (Sweden)

    Stéphanie Boulêtreau

    Full Text Available The ubiquity and fascinating nature of animal aggregations are widely recognised. We report here consistent and previously undocumented occurences of aggregations of a giant alien freshwater fish, the Wels catfish (Silurus glanis. Aggregative groups were on average composed of 25 (± 10 SD, ranging from 15 to 44 adults with estimated average total biomass of 651 kg (386 - 1132 and biomass density of 23 kg m(-2 (14 - 40. Aggregations always occurred within the same location. No foraging, reproductive or anti-predator behaviour were observed during the aggregations. A mass-balance model estimated that these colossal aggregations of an alien species can locally release, through excretion only, up to 70 mg P m(-2 h(-1 and 400 mg N m(-2 h(-1, potentially representing the highest biogeochemical hotspots reported in freshwater ecosystems and another unexpected ecological effect of alien species.

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

    Science.gov (United States)

    Sanches, A; Galetti Jr, P M

    2007-12-01

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

  11. Examining predictors of chemical toxicity in freshwater fish using the random forest technique.

    Science.gov (United States)

    Tuulaikhuu, Baigal-Amar; Guasch, Helena; García-Berthou, Emili

    2017-04-01

    Chemical pollution is one of the main issues globally threatening the enormous biodiversity of freshwater ecosystems. The toxicity of substances depends on many factors such as the chemical itself, the species affected, environmental conditions, exposure duration, and concentration. We used the random forest technique to examine the factors that mediate toxicity in a set of widespread fishes and analyses of covariance to further assess the importance of differential sensitivity among fish species. Among 13 variables, the 5 most important predictors of toxicity with random forests were, by order of importance, the chemical substance itself (i.e., Chemical Abstracts Service number considered as a categorical factor), octanol-water partition coefficient (log P), pollutant prioritization, ecological structure-activity relationship (ECOSAR) classification, and fish species for 50% lethal concentrations (LC50) and the chemical substance, fish species, log P, ECOSAR classification, and water temperature for no observed effect concentrations (NOECs). Fish species was a very important predictor for both endpoints and with the two contrasting statistical techniques used. Different fish species displayed very different relationships with log P, often with different slopes and with as much importance as the partition coefficient. Therefore, caution should be exercised when extrapolating toxicological results or relationships among species. In addition, further research is needed to determine species-specific sensitivities and unravel the mechanisms behind them.

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

    Directory of Open Access Journals (Sweden)

    A Sanches

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

  13. Fatty acid composition of freshwater wild fish in subalpine lakes: a comparative study.

    Science.gov (United States)

    Vasconi, Mauro; Caprino, Fabio; Bellagamba, Federica; Busetto, Maria Letizia; Bernardi, Cristian; Puzzi, Cesare; Moretti, Vittorio Maria

    2015-03-01

    In this study, the proximate and fatty acid compositions of the muscle tissue of 186 samples of fish belonging to fifteen species of freshwater fish harvested in subalpine lakes (bleak, shad, crucian carp, whitefish, common carp, pike, black bullhead, burbot, perch, Italian roach, roach, rudd, wels catfish, chub and tench) were investigated. Most of the fish demonstrated a lipid content in the fillet lower than 2.0 g 100 g(-1) wet weight (range 0.6-9.7). A strong relationship between feeding behavior and fatty acid composition of the muscle lipids was observed. Planktivorous fish showed the lowest amounts of n-3 fatty acids (p < 0.05), but the highest monounsaturated fatty acid (MUFA) contents, in particular 18:1n-9. Conversely, carnivorous fish showed the highest amounts of saturated fatty acids and n-3 fatty acids (p < 0.05), but the lowest MUFA contents. Omnivorous fish showed substantial proportions of n-3 fatty acids and the highest contents of n-6 fatty acids. Principal component analysis showed a distinct separation between fish species according to their feeding habits and demonstrated that the most contributing trophic markers were 18:1n-9, 18:3n-3, 22:6n-3 and 20:4n-6. The quantitative amounts n-3 polyunsaturated fatty acid in muscle tissues varied depending on the fish species, the lipid content and the feeding habits. Some species were very lean, and therefore would be poor choices for human consumption to meet dietary n-3 fatty acid requirements. Nevertheless, the more frequently consumed and appreciated fish, shad and whitefish, had EPA and DHA contents in the range 900-1,000 mg 100 g(-1) fresh fillet.

  14. Ecotoxicological effects of jute retting on the survival of two freshwater fish and two invertebrates.

    Science.gov (United States)

    Mondal, Debjit Kumar; Kaviraj, Anilava

    2008-04-01

    Severe deterioration of water quality occurs during jute retting in ponds, canals, floodplain lakes, and other inland water bodies in the rural areas of West Bengal in India. Attempts were made to evaluate changes in the physicochemical parameters of water caused by jute retting, and their impact on the survival of two species of freshwater fish (Labeo rohita and Hypophthalmicthys molitrix) and two species of freshwater invertebrate (Daphnia magna, a Cladocera, and Branchiura sowerbyi, an Oligochaeta). Results showed that jute retting in a pond for 30 days resulted in a sharp increase in the BOD (>1,000 times) and COD (>25 times) of the water, along with a sharp decrease in dissolved oxygen (DO). Free CO(2), total ammonia, and nitrate nitrogen also increased (three to five times) in water as a result of jute retting. Ninety-six-hour static bioassays performed in the laboratory with different dilutions of jute-retting water (JRW) revealed that D. magna and B. sowerbyi were not susceptible to even the raw JRW whereas fingerlings of both species of fish were highly susceptible, L. rohita being more sensitive (96 h LC(50) 37.55% JRW) than H. molitrix (96 h LC(50) 57.54% JRW). Mortality of fish was significantly correlated with the percentage of JRW.

  15. Parasites of freshwater fishes and the Great American Biotic Interchange: a bridge too far?

    Science.gov (United States)

    Choudhury, A; García-Varela, M; Pérez-Ponce de León, G

    2017-03-01

    We examine the extent to which adult helminths of freshwater fishes have been part of the Great American Biotic Interchange (GABI), by integrating information in published studies and new data from Panama with fish biogeography and Earth history of Middle America. The review illustrates the following: (1) the helminth fauna south of the Trans-Mexican Volcanic Belt, and especially south of the Isthmus of Tehuantepec, shows strong Neotropical affinities; (2) host-parasite associations follow principles of the 'biogeographic core fauna' in which host-lineage specificity is pronounced; (3) phylogenetic analysis of the widespread freshwater trematode family Allocreadiidae reveals a complex history of host-shifting and co-diversification involving mainly cyprinodontiforms and characids; (4) allocreadiids, monogeneans and spiruridan nematodes of Middle American cyprinodontiforms may provide clues to the evolutionary history of their hosts; and (5) phylogenetic analyses of cryptogonimid trematodes may reveal whether or how cichlids interacted with marine or brackish-water environments during their colonization history. The review shows that 'interchange' is limited and asymmetrical, but simple narratives of northward isthmian dispersal will likely prove inadequate to explain the historical biogeography of many host-parasite associations in tropical Middle America, particularly those involving poeciliids. Finally, our study highlights the urgent need for targeted survey work across Middle America, focused sampling in river drainages of Colombia and Venezuela, and deeper strategic sampling in other parts of South America, in order to develop and test robust hypotheses about fish-parasite associations in Middle America.

  16. Fishing for gaps in science: a bibliographic analysis of Brazilian freshwater ichthyology from 1986 to 2005.

    Science.gov (United States)

    Azevedo, P G; Mesquita, F O; Young, R J

    2010-06-01

    To investigate Brazilian freshwater ichthyology, from 1986 to 2005, a bibliometric analysis was conducted using abstracts downloaded from The Web of Science database searching for the keywords 'fish', 'pisces', 'teleostei' and the address field having the word 'Brazil'. The results of this study showed that Brazilian freshwater ichthyology publications have been increasing during the study period. This process is a consequence of a series of investments that the Brazilian Government has made. Furthermore, data analyses identified scientific areas where there was a lack of scientific knowledge (e.g. studies of species threatened with extinction and certain hydrologic basins). Research institutions from the north-east and northern region of Brazil had the lowest participation in scientific productivity, which was a reflection of their regions poorer economic situation. This study showed that scientific productivity in Brazilian ichthyology was a direct reflection of state investment in research. Furthermore, data in this study follow expected statistical probabilities, for example, fishes from the most diverse families were the most studied. Thus, the study shows that great progress has been made by Brazilian ichthyologists in the last 20 years; however, due to the mega diversity of fishes in Brazil, much remains to be done if many species are to become known to science and to be saved from extinction. This it seems will depend on continued and further investment by Brazilian Government funding agencies, as Brazilian ichthyologists have demonstrated their capacity to generate high quality information about their study species.

  17. The importance of environmental quality and catch potential to fishing site selection by freshwater anglers in Mississippi

    Science.gov (United States)

    Schramm, H.L.; Gerard, P.D.; Gill, D.A.

    2003-01-01

    We measured the importance of 24 fishing site attributes to Mississippi freshwater anglers. Factor analysis identified four multiattribute factors as important in the selection of fishing location: CLEAN ENVIRONMENT CATCH, COST AND HARVEST and AMENITIES AND SAFETY. In general, the importance of site selection factors differed little among anglers grouped by preferred type of fish, preferred fishing location (lakes and reservoirs, rivers and streams, ponds, or reservoir tailwaters), usual manner of fishing (engine-powered boat, nonpowered boat, or shore), or change in fishing frequency. COST AND HARVEST was more important to anglers with high harvest orientations. We found low correlations between site selection factor importance scores and angler age, fishing frequency, fishing expenditures, or fishing motivation factors. We suggest that the general lack of differences in site selection factors among angler groups indicates that management strategies to improve fishing site attributes should benefit all angler groups. Clean fishing environments and awareness of the availability of desired sport fishes were "very" or "extremely" important to fishing site selection by more than 70% of Mississippi freshwater anglers and should be priority management objectives.

  18. Comparative population genetic analysis of brackish- and freshwater populations of Eurasian perch (Perca fluviatilis L.: implication for fish forensics.

    Directory of Open Access Journals (Sweden)

    Lilian Pukk

    2015-11-01

    Full Text Available Understanding the genetic population structure of commercially important fish species is crucial for developing biologically sound management and conservation strategies. Genetic information can be also useful for fighting against illegal fishing and fish trade. Here, we studied commercially important brackish and freshwater populations of Eurasian perch (Perca fluviatilis L. in Estonia, to describe the genetic divergence among populations and evaluate the power of 16 microsatellite markers to assign individual fish and group of fish to their population of origin. To do so, a total of 785 individuals caught from 13 different sites in the Baltic Sea and four locations in Lake Peipus were analyzed. We found significant differences in genetic diversity between brackish and freshwater populations with Baltic Sea samples showing slightly lower allelic richness and heterozygosity compared to Lake Peipus. We also observed moderate genetic differentiation among populations (overall FST=0.034. Individual self-assignment tests assigned large proportion of individuals correctly back to freshwater or coastal origin (Lake Peipus: 87.1%; Baltic Sea: 89.4%. Also, when evaluating the origin of group of individuals, it was possible to identify the origin of the brackish and freshwater fish groups with very high confidence (log 10 LR > 2 when sample size was larger than 15. Our results demonstrate the power of highly variable genetic markers separating two commercially most important Eurasian perch stocks in Estonia and the usefulness of assignment tests to successfully identify the genetic origin of fish.

  19. Uptake, distribution in different tissues, and genotoxicity of imidacloprid in the freshwater fish Australoheros facetus.

    Science.gov (United States)

    Iturburu, Fernando G; Zömisch, Markus; Panzeri, Ana M; Crupkin, Andrea C; Contardo-Jara, Valeska; Pflugmacher, Stephan; Menone, Mirta L

    2017-03-01

    The neonicotinoid imidacloprid is under re-evaluation by regulatory agencies because of the poor current information available regarding its potential effects. One of the goals of the present study was to determine imidacloprid uptake and distribution in the freshwater fish Australoheros facetus experimentally exposed for 24 h and 48 h to 100 μg/L, 300 μg/L, and 2500 μg/L. The toxicity of imidacloprid to fish reported in the literature is in the milligrams per liter or gram per liter range, but sublethal effects at micrograms per liter in some groups other than fish have been described. Another goal of the present study was to evaluate imidacloprid's potential genotoxicity and to compare it between the individual compound and a commercial formulation. Concentrations of imidacloprid were measured in water, brain, muscle, gills, gut, liver, and blood by liquid chromatography-tandem mass spectrometry. Imidacloprid was detected in all the tissues tested. Concentrations were higher after 48 h than after 24 h in liver, gills, gut, and muscle, whereas in brain and blood they were similar at both exposure times. Although there was no accumulation, only uptake, of imidacloprid, genotoxicity was observed. In fish exposed to IMIDA NOVA 35(®) , increased micronucleus frequency at 100 µg/L and 1000 µg/L was detected, whereas in the imidacloprid active ingredient bioassay it increased only at 1000 µg/L imidacloprid. The present findings warn of the possible consequences that fish living in freshwater ecosystems can suffer. Environ Toxicol Chem 2017;36:699-708. © 2016 SETAC. © 2016 SETAC.

  20. Freshwater fish trypanosomes: definition of two types, host control by antibodies and lack of antigenic variation.

    Science.gov (United States)

    Overath, P; Haag, J; Mameza, M G; Lischke, A

    1999-12-01

    Haemoflagellates of the genus Trypanosoma are prevalent in freshwater fishes and are transmitted by leeches as vectors. As demonstrated by sequence comparisons of nuclear small subunit rRNA genes, trypanosomes isolated from several fish species at different localities can be divided into at least 2 closely related types, designated Type A and Type B. A clone derived from a Type A isolate from carp (Cyprinus carpio) was used to study the anti-parasite immune response in specified pathogen-free outbred carp. Infection leads to an initial rise in parasitaemia in the blood followed by a sharp decline in all fish (acute phase). Thereafter, in some carp, parasites become undetectable both in the blood and in internal organs while, in others, low numbers can be found in the blood for up to 1 year (chronic phase). Fish that have controlled an acute infection with the clone are not only protected against an homologous challenge infection, but also against the infection with parasite lines derived from carp in the chronic phase of infection. Passive immunization experiments with IgM purified from serum of recovered carp indicate that the infection is controlled by antibodies. The anti-parasite antibody level in recovered carp remains high for many months although the parasitaemia is controlled at very low levels and the half life of IgM, t1/2 = 22.5 days, is comparatively short. The effective control of trypanosomes in laboratory infections is in contrast to the high prevalence in natural and farmed freshwater fish populations.

  1. Diseases of cultured marine fishes caused by Platyhelminthes (Monogenea, Digenea, Cestoda).

    Science.gov (United States)

    Ogawa, K

    2015-01-01

    Mariculture is a rapidly developing industrial sector. Generally, fish are maintained in net cages with high density. Cage culture systems allow uncontrolled flow of sea water containing potentially infectious stages of fish parasites. In such culture conditions, prevention of such parasitic infections is difficult for parasites with life cycles that complete within culture sites, among which monogeneans and blood flukes are the most important platyhelminthes. Intense monogenean infections induce respiratory and osmo-regulatory dysfunctions. A variety of control measures have been developed, including freshwater bath treatment and chemotherapy. The potential to control monogenean infections through selective breeding, modified culture techniques to avoid infection, and general fish health management are discussed. It should be noted that mariculture conditions have provided some host-specific monogeneans with a chance to expand their host ranges. Blood flukes sometimes induce mass mortality among farmed fish. In-feed administration of praziquantel is the best solution to treat infected fish. Some cases are described that show how international trade in marine fish has resulted in the spread of hitherto unknown parasites into indigenous farmed and wild fish.

  2. Acanthamoeba sohi, n. sp., a pathogenic Korean isolate YM-4 from a freshwater fish

    OpenAIRE

    Im, Kyung-Il; Shin, Ho-Joon

    2003-01-01

    A new species of Acanthamoeba was isolated from a freshwater fish in Korea and tentatively named Acanthamoeba sp. YM-4 (Korean isolate YM-4). The trophozoites were 11.0-23.0 µm in length and had hyaline filamentous projections. Cysts were similar to those of A. culbertsoni and A. royreba, which were previously designated as Acanthamoeba group III. Acanthamoeba YM-4 can survive at 40℃, and its generation time was 19.6 hr, which was longer than that of A. culbertsoni. In terms of the in vitro c...

  3. Non-native fishes in Florida freshwaters: a literature review and synthesis

    Science.gov (United States)

    Schofield, Pamela J.; Loftus, William F.

    2015-01-01

    Non-native fishes have been known from freshwater ecosystems of Florida since the 1950s, and dozens of species have established self-sustaining populations. Nonetheless, no synthesis of data collected on those species in Florida has been published until now. We searched the literature for peer-reviewed publications reporting original data for 42 species of non-native fishes in Florida that are currently established, were established in the past, or are sustained by human intervention. Since the 1950s, the number of non-native fish species increased steadily at a rate of roughly six new species per decade. Studies documented (in decreasing abundance): geographic location/range expansion, life- and natural-history characteristics (e.g., diet, habitat use), ecophysiology, community composition, population structure, behaviour, aquatic-plant management, and fisheries/aquaculture. Although there is a great deal of taxonomic uncertainty and confusion associated with many taxa, very few studies focused on clarifying taxonomic ambiguities of non-native fishes in the State. Most studies were descriptive; only 15 % were manipulative. Risk assessments, population-control studies and evaluations of effects of non-native fishes were rare topics for research, although they are highly valued by natural-resource managers. Though some authors equated lack of data with lack of effects, research is needed to confirm or deny conclusions. Much more is known regarding the effects of lionfish (Pterois spp.) on native fauna, despite its much shorter establishment time. Natural-resource managers need biological and ecological information to make policy decisions regarding non-native fishes. Given the near-absence of empirical data on effects of Florida non-native fishes, and the lengthy time-frames usually needed to collect such information, we provide suggestions for data collection in a manner that may be useful in the evaluation and prediction of non-native fish effects.

  4. Tissue preference of some myxobolids (Myxozoa: Myxosporea) from the musculature of European freshwater fishes.

    Science.gov (United States)

    Molnár, Kálmán; Székely, Csaba

    2014-01-16

    For several species of fish myxosporeans known at present, the musculature has been designated as the location of intrapiscine development. In the majority of these cases, plasmodia and spores are actually found in the muscle cells, but there are also myxosporeans that select intermuscular connective tissue, fish bones, nerves and capillaries of the musculature as their site of development. During the plasmodial development of Myxobolus, Henneguya and Thelohanellus species in fish inhabiting Hungarian freshwaters, 3 main locations of development inside the muscles were identified. Pseudodispar-type plasmodia, such as M. cyprini, M. musculi and M. pseudodispar, form plasmodia intracellularly in the muscle cells, while the plasmodia of M. pfeifferi, M. sandrae and T. hovorkai develop in the intermuscular connective tissue. A similar development in the connective tissue of the ventricle and the bulbus arteriosus was observed for M. dogieli, a heart parasite found in some cyprinid fishes. The third type of development is represented by M. tauricus, which prefers the collagenous elements of the fin rays, but its plasmodia are commonly found in the muscle attached to the fish bones.

  5. Evaluation of organ distribution of microcystins in the freshwater phytoplanktivorous fish Hypophthalmichthys molitrix

    Institute of Scientific and Technical Information of China (English)

    ZHANG Hang-jun; ZHANG Jian-ying; HONG Ye; CHEN Ying-xu

    2007-01-01

    To evaluate the public health risk of exposure to microcystins in fish food in China, the distribution pattern of microcystin-LR and microcystin-RR in various organs (liver, intestine, kidney, muscle and lipid) of the dominant freshwater phytoplanktivorous fish Hypophthalmichthys molitrix in Hangzhou, China's Tiesha River was investigated with the method of HPLC-ESI-MS analysis. The distribution of microcystins was different in the fish organs and the major total microcystins (microcystin-LR and microcystin-RR) were present in the intestines (6.49 μg/g fresh weight), followed by the livers (4.52 μg/g fresh weight) and the muscles (2.86 μg/g fresh weight). Microcystins were detected in kidneys (1.35 μg/g fresh weight), but not detected in lipid. The results suggested that the mean daily intake from fish was 0.03 μg/kg body weight which was very close to the recommended WHO tolerable daily intake (TDI) level of 0.04 μg/kg body weight per day, and local people were warned they may have health risk if they consumed fish from the river.

  6. Global functional diversity of freshwater fish is concentrated in the Neotropics while functional vulnerability is widespread.

    Science.gov (United States)

    Toussaint, A; Charpin, N; Brosse, S; Villéger, S

    2016-03-16

    Worldwide biodiversity assessments have mainly focused on species richness but little is known about the diversity of species roles, i.e. functional diversity, while this is a key facet to understanding the consequences of global changes on the ecosystem services to human societies. Here, we report the world pattern of functional diversity of freshwater fish using a database encompassing morphological characteristics of more than 9,000 species. The Neotropical realm hosts more than 75% of global functional diversity while other realms each host less than 25%. This discrepancy is mediated by high functional uniqueness in some diversified Neotropical fish orders. Surprisingly, functional diversity patterns were weakly related to functional vulnerability. In the Neotropics the loss of threatened species will cause a limited loss of functional diversity (functional diversity will reach 43% and 33%, respectively, conferring a high functional vulnerability to these realms. Conservation of the Neotropical fish diversity is a key target to maintain world fish functional diversity, but this should not hide the pressing need to conserve the vulnerable fish faunas of the rest of the world, in which functional diversity is to a large extent supported by threatened species.

  7. Risk assessment of fish health and fish welfare in freshwater production systems

    OpenAIRE

    Norwegian Scientific Committee for Food Safety

    2014-01-01

    Physical conditions such as water quantity, water depths, receiver capacity for pollution, currents and renewal of water, is more limited in lakes than in the sea. The consequence is that fresh water farms must be smaller. Signs of pollution from fish farms will appear at an earlier stage than in the sea, and monitoring of water quality in and outside the farm is important to ensure good conditions for the fish.

  8. Late Pleistocene fishes of the Tennessee River Basin: an analysis of a late Pleistocene freshwater fish fauna from Bell Cave (site ACb-2) in Colbert County, Alabama, USA

    OpenAIRE

    Jacquemin, Stephen J.; Jun A. Ebersole; Dickinson, William C.; Charles N Ciampaglio

    2016-01-01

    The Tennessee River Basin is considered one of the most important regions for freshwater biodiversity anywhere on the globe. The Tennessee River Basin currently includes populations of at least half of the described contemporary diversity of extant North American freshwater fishes, crayfish, mussel, and gastropod species. However, comparatively little is known about the biodiversity of this basin from the Pleistocene Epoch, particularly the late Pleistocene (∼10,000 to 30,000 years B.P.) lead...

  9. Chloride uptake and base secretion in freshwater fish: a transepithelial ion-transport metabolon?

    Science.gov (United States)

    Tresguerres, Martin; Katoh, Fumi; Orr, Elizabeth; Parks, Scott K; Goss, Greg G

    2006-01-01

    Despite all the efforts and technological advances during the last few decades, the cellular mechanisms for branchial chloride uptake in freshwater (FW) fish are still unclear. Although a tight 1 : 1 link with HCO-3 secretion has been established, not much is known about the identity of the ion-transporting proteins involved or the energizing steps that allow for the inward transport of Cl- against the concentration gradient. We propose a new model for Cl- uptake in FW fish whereby the combined action of an apical anion exchanger, cytoplasmic carbonic anhydrase, and basolateral V-type H+ -ATPase creates a local [HCO-3] high enough to energize Cl- uptake. Our model is based on analyses of structure-function relationships, reinterpretation of previous results, and novel observations about gill cell subtypes and immunolocalization of the V-H+ -ATPase.

  10. Comparative scale morphologies in common freshwater fishes of Peninsular Malaysia - A case study

    Science.gov (United States)

    Farah-Ayuni, F.; Muse, A. O.; Samat, A.; Shukor, M. N.

    2016-11-01

    Hard plates covering fish body or scales, do not only serve as external protection, but are also important as one of the tools for species identification. This study was designed to recognise morphological characters of fish scales that can be used for identification and to comprehend the inter-specific variations of scales from different species by using selected indices from scale measurements; L1/1, L2/L, L1/L2, and W/L. Sixteen species of common freshwater fishes were sampled from a few localities in Peninsular Malaysia. Examinations were based on photographs to determine the scale morphologies. Basic distinguishable characteristics that were identified are type of scale, the overall shape, the position and shape of the focus, distribution of radii, and the circuli appearance. It was found that scale type and radii arrangement at the anterior field are two significant morphological features that could distinguish between Cyprinidae and other families. Main characters used to identify scales at species level are radii cover, structure of inter radial tongue, and radii arrangement. Meanwhile, multiple comparison tests to reveal inter-specific variations suggested that there are significant differences among 16 species of common freshwater fishes studied. Two indices were found to be suitable to highlight the significant differences (P<0.05) for all species which are index L1/L2 and index W/L. For all indices, species that showed significantly different with most of other species are Osteochilus vittatus, Pristolepis fasciata, Rasbora sumatrana, and Labeo rohita. The scales of Osteochilus vittatus showed significant values with most of other species in more than one index; index L1/L and index L2/L. The distinctive morphological character that distinguished it from other Cyprinidae species is having clearly formed serrations in the middle of the inter-radial tongue at the anterior region.

  11. Patterns of interaction between Neotropical freshwater fishes and their gill Monogenoidea (Platyhelminthes).

    Science.gov (United States)

    Braga, Mariana P; Araújo, Sabrina B L; Boeger, Walter A

    2014-02-01

    Using network analysis, we looked for broad patterns of distribution of Monogenoidea gill parasites on Neotropical freshwater fishes within a host phylogenetic framework. We analyzed a database of Monogenoidea parasitizing fishes from Neotropical rivers, from 23 watersheds, based on species descriptions published until 2011. Host-parasite interactions were organized into five matrices grouping species at different taxonomic levels. The network of interactions between host families and parasite genera was significantly modular and revealed that each fish order has a unique composition of parasite genera. Hence, interactions between lower taxa were analyzed separately for the largest fish orders (Perciformes, Siluriformes, and Characiformes). Networks tended to be loosely connected and organized in modules. Despite the putative high host specificity of monogenoids, some have a wider host range that includes distantly related host species. Among the hosts, the clade composed by the piranhas (Serrasalmus spp. and related species, Serrasalmidae) stands out in terms of parasite richness per host species, resulting in a more connected network. The history of the lineages of each host order within Neotropical freshwaters seems to have a great influence on the extent of parasite sharing. The observed modularity was influenced by both spatial structure and phylogenetic relatedness of species. In average, 37 % of modules of networks between host species and parasite genera were associated with a particular river basin and 63 % of modules were associated with a host family. Hence, spatial structure determines the co-occurrence of host and parasite species, but their evolutionary history is the main factor defining which interactions are possible.

  12. Biochemical responses in freshwater fish after exposure to water-soluble fraction of gasoline.

    Science.gov (United States)

    Bettim, Franciele Lima; Galvan, Gabrieli Limberger; Cestari, Marta Margarete; Yamamoto, Carlos Itsuo; de Assis, Helena Cristina Silva

    2016-02-01

    The water-soluble fraction of gasoline (WSFG) is a complex mixture of mono-polycyclic aromatic hydrocarbons. The study aimed to evaluate the effects of WSFG diluted 1.5% on freshwater fish. Astyanax altiparanae were exposed to the WSFG for 96 h, under a semi-static system, with renewal of 25% of the gasoline test solution every 24 h. In addition, a decay of the contamination (DC) was carried out. During DC, the fish was exposed to the WSFG for 8 d, followed by another 7 d with renewal of 25% of volume aquaria with clean water every 24 h. For depuration, fish were transferred to aquaria with clean water, and in addition, 25% of the water was replaced every 24 h. The liver and kidney biotransformation, antioxidant defenses and lipid peroxidation (LPO) levels were evaluated. In the liver, the WSFG 1.5% caused reduction of glutathione S-transferase (GST) after 96 h and DC. In the kidney, only in depuration an increased GST activity was observed, and after DC a higher LPO levels. An increase of the superoxide dismutase (SOD) activity occurred at 96 h in both tissues; however, in the liver was also observed during the depuration. In WSFG 96 h, the glutathione peroxidase (GPx) activity in the kidney increased. As biomarkers of neurotoxicity, the brain and muscle acetylcholinesterase activities were measured, but the WSFG 1.5% did not change them. Therefore, this study brought forth more data about WSFG effects on freshwater fish after lower concentrations exposure and a DC, simulating an environmental contamination.

  13. Accumulation of polychlorinated biphenyls in the freshwater fish, crucian, from the Han river and the Kum river, Korea

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, G.H.; Kim, Y.B.; Moon, J.Y.; Lee, S.I.; Kim, H.; Song, H. [Pusan National Univ. (Korea)

    2004-09-15

    Even though polychlorinated biphenyls(PCBs) were prohibited from producing and using for a long time, it is still identified in the every environmental media including biota. Since PCBs are lipophilic and persistent, they concentrate readily in the tissue and accumulate exponentially as they move through the food chain. Crucian (Carassius auratus) is most widely living freshwater fish in Korea. So crucian was selected as a representative freshwater fish in this study to determine the accumulation level and distribution characteristics of PCBs. In this study, we attempted to investigate the accumulation profile of individual PCB congeners in the muscle of freshwater fish crucian from the two major rivers, the Han River and Kum River, in Korea.

  14. (90)Sr in fish from the southern Baltic Sea, coastal lagoons and freshwater lake.

    Science.gov (United States)

    Zalewska, Tamara; Saniewski, Michał; Suplińska, Maria; Rubel, Barbara

    2016-07-01

    Activity concentrations of radioactive (90)Sr were studied in four fish species: herring, flounder, sprat and cod caught in the southern Baltic Sea in two periods: 2005-2009 and 2013-2014. The study included also perch from the coastal lagoons - Vistula Lagoon and Szczcin Lagoon and a freshwater lake - Żarnowieckie Lake as well as additional lake species: pike and bream. (90)Sr activity concentrations were compared in relation to species and to particular tissue: muscle, whole fish (eviscerated) and bones. In 2014, in the Baltic, the maximal (90)Sr concentrations were found in fishbones: herring - 0.39 Bq kg(-1) w.w., cod - 0.48 Bq kg(-1) w.w., and flounder - 0.54 Bq kg(-1) w.w. In the whole fish the maximal concentrations were found in flounder - 0.16 Bq kg(-1) w.w. and cod - 0.15 Bq kg(-1) w.w., while in herring - 0.022 Bq kg(-1) w.w. and sprat - 0.026 Bq kg(-1) w.w. they stayed at lower level. Relatively high (90)Sr concentrations were detected in whole fish from freshwater Lake Żarnowieckie: perch - 0.054 Bq kg(-1) w.w., pike - 0.062 Bq kg(-1) w.w. and bream - 0.140 Bq kg(-1) w.w. Concentration ratio (CR) determined for particular fish tissues and for whole eviscerated fish in relation to (90)Sr concentrations in seawater and lake water were showing significant variability unlike the corresponding (137)Cs concentration ratios which are stable and specific for fish species. The study corroborates with the conviction of the growing role of (90)Sr in the overall radioactivity in the southern Baltic Sea as compared to (137)Cs.

  15. The cold-water connection: Bergmann's rule in North American freshwater fishes.

    Science.gov (United States)

    Rypel, Andrew L

    2014-01-01

    Understanding general rules governing macroecological body size variations is one of the oldest pursuits in ecology. However, this science has been dominated by studies of terrestrial vertebrates, spurring debate over the validity of such rules in other taxonomic groups. Here, relationships between maximum body size and latitude, temperature, and elevation were evaluated for 29 North American freshwater fish species. Bergmann's rule (i.e., that body size correlates positively with latitude and negatively with temperature) was observed in 38% of species, converse Bergmann's rule (that body size correlates negatively with latitude and positively with temperature) was observed in 34% of species, and 28% of species showed no macroecological body size relationships. Most notably, every species that expressed Bergmann's rule was a cool- or cold-water species while every species that expressed converse Bergmann's rule was a warm-water species, highlighting how these patterns are likely connected to species thermal niches. This study contradicts previous research suggesting Bergmann's rule does not apply to freshwater fishes, and is congruent with an emerging paradigm of variable macroecological body size patterns in poikilotherms.

  16. Probing diversity in freshwater fishes from Mexico and Guatemala with DNA barcodes.

    Science.gov (United States)

    Valdez-Moreno, M; Ivanova, N V; Elías-Gutiérrez, M; Contreras-Balderas, S; Hebert, P D N

    2009-02-01

    The freshwater fish fauna of Mexico and Guatemala is exceptionally diverse with >600 species, many endemic. In this study, patterns of sequence divergence were analysed in representatives of this fauna using cytochrome c oxidase subunit 1 (COI) DNA barcodes for 61 species in 36 genera. The average divergence among conspecific individuals was 0.45%, while congeneric taxa showed 5.1% divergence. Three species of Poblana, each occupying a different crater lake in the arid regions of Central Mexico, have had a controversial taxonomic history but are usually regarded as endemics to a single lake. They possess identical COI barcodes, suggesting a very recent history of isolation. Representatives of the Cichlidae, a complex and poorly understood family, were well discriminated by barcodes. Many species of Characidae seem to be young, with low divergence values (clusters were apparent in the Bramocharax-Astyanax complex. The symbranchid, Opisthernon aenigmaticum, has been regarded as a single species ranging from Guatemala to Mexico, but it includes two deeply divergent barcode lineages, one a possible new endemic species. Aside from these special cases, the results confirm that DNA barcodes will be highly effective in discriminating freshwater fishes from Central America and that a comprehensive analysis will provide new important insights for understanding diversity of this fauna.

  17. Trematode diversity in freshwater fishes of the Globe II: 'New World'.

    Science.gov (United States)

    Choudhury, Anindo; Aguirre-Macedo, M Leopoldina; Curran, Stephen S; de Núñez, Margarita Ostrowski; Overstreet, Robin M; de León, Gerardo Pérez-Ponce; Santos, Cláudia Portes

    2016-03-01

    We provide a summary overview of the diversity of trematode parasites in freshwater fishes of the 'New World', i.e. the Americas, with emphasis on adult forms. The trematode fauna of three regions, South America, Middle America, and USA and Canada (North America north of Mexico), are considered separately. In total, 462 trematode species have been reported as adults from the Americas. The proportion of host species examined for parasites varies widely across the Americas, from a high of 45% in the Mexican region of Middle America to less than 5% in South America. North and South America share no adult species, and one exclusively freshwater genus, Creptotrema Travassos, Artigas & Pereira, 1928 in the Allocreadiidae Looss, 1902 is the most widely distributed. Metacercariae of strigeiforms maturing in fish-eating birds (e.g. species of the Diplostomidae Poirier, 1886) are common and widely distributed. The review also highlights the paucity of known life-cycles. The foreseeable future of diversity studies belongs to integrative approaches and the application of molecular ecological methods. While opportunistic sampling will remain important in describing and cataloguing the trematode fauna, a better understanding of trematode diversity and biology will also depend on strategic sampling throughout the Americas.

  18. Reproductive impairment of a viviparous fish species inhabiting a freshwater system with anthropogenic impact.

    Science.gov (United States)

    Hued, Andrea Cecilia; Nostro, Fabiana Laura Lo; Wunderlin, Daniel Alberto; Bistoni, María de Los Ángeles

    2013-02-01

    The potential threat to animal reproduction by contaminated freshwater systems posed the necessity to identify and develop bioindicators and biomarkers to be used for screening and evaluation of the effects in organisms. The main goal of this work was to determine, through histological analyses and changes in gonopodium morphology, whether a freshwater system polluted by anthropogenic activities-sewage, agricultural, and industrial-could cause alterations at the organ level. We also propose the live-bearing fish, Jenynsia multidentata, as a species suitable to study the effects of contaminated aquatic environments. We compared male fish sampled at two different stations in Suquía River basin (Córdoba, Argentina), both differing in degree of pollution, through liver and testis histology and gonopodial morphometric parameters. The water quality, based on the physicochemical characteristics of the studied stations, varied markedly with a decrease in water quality at the downstream site (station 2). At the highest polluted area, detrimental effects on liver and testis were evidenced on histological analysis. Male individuals from station 2 also presented noticeable structural changes of the anal fin, such as a straight gonopodium and abnormal tip area. The present results demonstrate that a freshwater system polluted by the impacts of anthropogenic activities has detrimental effects to J. multidentata. The alterations registered in individuals from the polluted station indicate an impairment of male reproductive performance and imply a risk for other live-bearing species as well as the entire biodiversity. We consider J. multidentata a sentinel species that is useful to evaluate the potential risk present in the studied basin not only to itself but to other species as well.

  19. Histopathology of feral fish from a PCB-contaminated freshwater lake

    Energy Technology Data Exchange (ETDEWEB)

    Koponen, Kari; Ritola, Ossi; Huuskonen, Sirpa E.; Lindstroem-Seppae, Pirjo [Univ. of Kuopio (Finland). Dept. of Physiology; Myers, Mark S. [National Oceanic and Atmospheric Administration, Seattle, WA (United States). National Marine Fisheries Service

    2001-05-01

    The purpose of this study was to evaluate the potential toxic effects of chronic sublethal polychlorinated biphenyl (PCB) exposure on feral fish, using histopathology as an endpoint. Histopathological study of bream (Abramis brama) and asp (Aspius aspius) living in a PCB-polluted freshwater lake revealed abnormal cellular changes in the renal corpuscle of both species. Dilation of glomerular capillaries (DGC), mesangial edema (ME), an adhesion between visceral and parietal layers of Bowman's capsule (ABC), and filling of Bowman's space (FBS), were highly prevalent features in lake fish. The prevalence of each of these lesions was significantly lower, or totally absent in fish caught from reference locations. Cellular alterations in liver, gill, gonads, spleen, and intestine were all linked to seasonal changes. The results suggest that some of the observed histopathological changes in renal glomeruli, particularly DGC and ME, could possibly indicate a prolonged chemical stress caused by PCBs and related compounds. It is also possible that chronic PCB exposure may have suppressed and weakened the immuno systems of exposed fish making them more vulnerable to secondary parasitic infection.

  20. Evaluation of a Method for Quantifying Eugenol Concentrations in the Fillet Tissue from Freshwater Fish Species.

    Science.gov (United States)

    Meinertz, Jeffery R; Schreier, Theresa M; Porcher, Scott T; Smerud, Justin R

    2016-01-01

    AQUI-S 20E(®) (active ingredient, eugenol; AQUI-S New Zealand Ltd, Lower Hutt, New Zealand) is being pursued for approval as an immediate-release sedative in the United States. A validated method to quantify the primary residue (the marker residue) in fillet tissue from AQUI-S 20E-exposed fish was needed. A method was evaluated for determining concentrations of the AQUI-S 20E marker residue, eugenol, in freshwater fish fillet tissue. Method accuracies from fillet tissue fortified at nominal concentrations of 0.15, 1, and 60 μg/g from six fish species ranged from 88-102%. Within-day and between-day method precisions (% CV) from the fortified tissue were ≤8.4% CV. There were no coextracted compounds from the control fillet tissue of seven fish species that interfered with eugenol analyses. Six compounds used as aquaculture drugs did not interfere with eugenol analyses. The lower limit of quantitation (LLOQ) was 0.012 μg/g. The method was robust, i.e., in most cases, minor changes to the method did not impact method performance. Eugenol was stable in acetonitrile-water (3 + 7, v/v) for at least 14 days, in fillet tissue extracts for 4 days, and in fillet tissue stored at ~ -80°C for at least 84 days.

  1. Chernobyl radiocesium in freshwater fish: Long-term dynamics and sources of variation

    Energy Technology Data Exchange (ETDEWEB)

    Sundbom, M. [Uppsala Univ., Dept. of Limnology, Uppsala (Sweden)

    2002-04-01

    The aim of this thesis was to investigate both the long-term temporal pattern and sources of individual variation for radiocesium in freshwater fish. The basis for the study is time series of {sup 137}Cs activity concentrations in fish from three lakes in the area North-west of Uppsala, Sweden that received considerable amounts of {sup 137}Cs from Chernobyl in may 1986. The lakes were Lake Ekholmssjoen, Lake Flatsjoen and Lake Siggeforasjoen, all small forest lakes, but with different morphometrical and chemical characteristics. The data were collected regularly, usually several times per year, during 1986-2000, using consistent methods. More than 7600 fish individuals from 7 species covering wide size ranges and feeding habits were analysed for {sup 137}Cs. For each fish was the length, weight, sex, and often the stomach contend recorded. The evaluation on long-term trends were based on data from all three lakes, while the study on sources of variation evaluated data from Lake Flatsjoen only. (au)

  2. Can backcalculation models unravel complex larval growth histories in a tropical freshwater fish?

    Science.gov (United States)

    Starrs, D; Ebner, B C; Fulton, C J

    2013-07-01

    This experimental study compared the precision and accuracy of the biological intercept (BI), modified fry (MF) and time-varying growth (TVG) backcalculation models in estimating the early growth of the tropical freshwater purple-spotted gudgeon Mogurnda adspersa. Larvae were reared up to 41 days post hatching under two temperatures and four different feeding regimes. Food and temperature treatments induced complex growth profiles among fish, and although total length (LT ) and otolith radius were related under all conditions, some uncoupling was evident in the otolith-somatic-growth (OSG) relationship of fish subjected to periods of changing food availability. Furthermore, otolith growth was found to be significantly influenced by temperature, but not by food availability. Analysis of backcalculation residuals by linear mixed effects modelling revealed that BI and TVG were equally precise in predicting somatic growth, with the highest accuracy provided by TVG. The performance of all the three models declined as the OSG relationship weakened under low-food conditions, with maximum errors estimated to be 39, 60 and 36% of observed LT for the BI, MF and TVG models, respectively. The need for careful validation of backcalculation models is emphasized when examining fishes subjected to variable environmental conditions, and when exploring the differential influence of temperature and food on fish LT and otolith growth.

  3. Bioconcentration and Acute Intoxication of Brazilian Freshwater Fishes by the Methyl Parathion Organophosphate Pesticide

    Directory of Open Access Journals (Sweden)

    João Bosco de Salles

    2015-01-01

    Full Text Available Three species of freshwater Brazilian fishes (pacu, Piaractus mesopotamicus; piavussu, Leporinus macrocephalus, and curimbatá, Prochilodus lineatus were exposed to an acute dose of 5 ppm methyl parathion organophosphate pesticide. Three to five individuals per species were exposed, one at a time, to 40 liters tap water spiked with Folidol 600. Pesticide concentrations and cholinesterase (ChE activities were evaluated in serum, liver, brain, heart, and muscle. The bioconcentration of methyl parathion was similar for all studied fishes. Brain tissue showed the highest pesticide concentration, reaching 80 ppm after exposure for 30 min to methyl parathion. Three to 5 hours of 5 ppm methyl parathion exposure provoked the death of all P. lineatus at 92% brain AChE inhibition, whereas fish from the other two species survived for up to 78 hours with less than 80% brain AChE inhibition. Our results indicate that acute toxic effects of methyl parathion to fish are correlated with brain AChE sensitivity to methyl paraoxon.

  4. Bioconcentration and Acute Intoxication of Brazilian Freshwater Fishes by the Methyl Parathion Organophosphate Pesticide

    Science.gov (United States)

    Bosco de Salles, João; Matos Lopes, Renato; de Salles, Cristiane M. C.; Cassano, Vicente P. F.; de Oliveira, Manildo Marcião; Cunha Bastos, Vera L. F.; Bastos, Jayme Cunha

    2015-01-01

    Three species of freshwater Brazilian fishes (pacu, Piaractus mesopotamicus; piavussu, Leporinus macrocephalus, and curimbatá, Prochilodus lineatus) were exposed to an acute dose of 5 ppm methyl parathion organophosphate pesticide. Three to five individuals per species were exposed, one at a time, to 40 liters tap water spiked with Folidol 600. Pesticide concentrations and cholinesterase (ChE) activities were evaluated in serum, liver, brain, heart, and muscle. The bioconcentration of methyl parathion was similar for all studied fishes. Brain tissue showed the highest pesticide concentration, reaching 80 ppm after exposure for 30 min to methyl parathion. Three to 5 hours of 5 ppm methyl parathion exposure provoked the death of all P. lineatus at 92% brain AChE inhibition, whereas fish from the other two species survived for up to 78 hours with less than 80% brain AChE inhibition. Our results indicate that acute toxic effects of methyl parathion to fish are correlated with brain AChE sensitivity to methyl paraoxon. PMID:26339593

  5. Evaluation of a method for quantifying eugenol concentrations in the fillet tissue from freshwater fish species

    Science.gov (United States)

    Meinertz, Jeffery R.; Schreier, Theresa M.; Porcher, Scott T.; Smerud, Justin R.

    2016-01-01

    AQUI-S 20E® (active ingredient, eugenol; AQUI-S New Zealand Ltd, Lower Hutt, New Zealand) is being pursued for approval as an immediate-release sedative in the United States. A validated method to quantify the primary residue (the marker residue) in fillet tissue from AQUI-S 20E–exposed fish was needed. A method was evaluated for determining concentrations of the AQUI-S 20E marker residue, eugenol, in freshwater fish fillet tissue. Method accuracies from fillet tissue fortified at nominal concentrations of 0.15, 1, and 60 μg/g from six fish species ranged from 88–102%. Within-day and between-day method precisions (% CV) from the fortified tissue were ≤8.4% CV. There were no coextracted compounds from the control fillet tissue of seven fish species that interfered with eugenol analyses. Six compounds used as aquaculture drugs did not interfere with eugenol analyses. The lower limit of quantitation (LLOQ) was 0.012 μg/g. The method was robust, i.e., in most cases, minor changes to the method did not impact method performance. Eugenol was stable in acetonitrile–water (3 + 7, v/v) for at least 14 days, in fillet tissue extracts for 4 days, and in fillet tissue stored at ~ −80°C for at least 84 days.

  6. Mitigating the impact of oil-palm monoculture on freshwater fishes in Southeast Asia.

    Science.gov (United States)

    Giam, Xingli; Hadiaty, Renny K; Tan, Heok Hui; Parenti, Lynne R; Wowor, Daisy; Sauri, Sopian; Chong, Kwek Yan; Yeo, Darren C J; Wilcove, David S

    2015-10-01

    Anthropogenic land-cover change is driving biodiversity loss worldwide. At the epicenter of this crisis lies Southeast Asia, where biodiversity-rich forests are being converted to oil-palm monocultures. As demand for palm oil increases, there is an urgent need to find strategies that maintain biodiversity in plantations. Previous studies found that retaining forest patches within plantations benefited some terrestrial taxa but not others. However, no study has focused on aquatic taxa such as fishes, despite their importance to human well-being. We assessed the efficacy of forested riparian reserves in conserving freshwater fish biodiversity in oil-palm monoculture by sampling stream fish communities in an oil-palm plantation in Central Kalimantan, Indonesia. Forested riparian reserves maintained preconversion local fish species richness and functional diversity. In contrast, local and total species richness, biomass, and functional diversity declined markedly in streams without riparian reserves. Mechanistically, riparian reserves appeared to increase local species richness by increasing leaf litter cover and maintaining coarse substrate. The loss of fishes specializing in leaf litter and coarse substrate decreased functional diversity and altered community composition in oil-palm plantation streams that lacked riparian reserves. Thus, a land-sharing strategy that incorporates the retention of forested riparian reserves may maintain the ecological integrity of fish communities in oil-palm plantations. We urge policy makers and growers to make retention of riparian reserves in oil-palm plantations standard practice, and we encourage palm-oil purchasers to source only palm oil from plantations that employ this practice. © 2015 Society for Conservation Biology.

  7. Photosynthesis and fish production in culture ponds

    Energy Technology Data Exchange (ETDEWEB)

    Szyper, J.P.

    1995-12-31

    The widely-cultured Nile tilapia, Oreochromis niloticus, has been the major species used in standardized experiments by the Pond Dynamics/Aquaculture Collaborative Research Support Program (PD/ACRSP). Yields of Nile Tilapia from fertilized, unfed ponds have served as a bioassay for effectiveness of pond management protocols developed during worldwide tropical experiments. Yield rates near 10 T/ha/y can be achieved without feed inputs in ponds which maintain high standing stocks of phytoplankton and exhibit high rates near 10 T/ha/y can be achieved without feed inputs in ponds which maintain high standing stocks of phytoplankton and exhibit high rates of primary production. Fish production is related to daytime net photosynthetic production, but it is not clear whether production of food materials or oxygen is the more direct influence. Excessively high standing stocks of phytoplankton are not the best net producers, and increase and risk of nighttime oxygen depletion. Fish readily grow to individual sizes of 200-300 g/fish in fertilized ponds, which is sufficient market size in many locations. Supplemental feeding of caged or free-ranging fish greatly accelerates growth beyond 300 g and potentiates high areal yields; the PD/A CRSP has also developed efficient feeding regimes and shown that supplemental feeding need not begin before fish reach 200 g weight. High standing stocks of phytoplankton and high photosynthetic rates in eutrophic ponds make study of photosynthesis possible without radioisotopes. Such ponds also exhibit complete extinction of incident solar radiation within shallow depths, and vertical temperature structure resembling that of deeper bodies of water. These characteristics make ponds useful as microcosms for study of some aspects of photosynthesis in natural waters.

  8. Bioaccumulation and Depuration of Copper in the Kidney and Liver of a Freshwater Fish, Capoeta fusca

    Directory of Open Access Journals (Sweden)

    Borhan Mansouri

    2016-07-01

    Full Text Available Background: This study aims to investigate the patterns of bioaccumulation and depuration of copper in the selected kidney and liver of Capoeta fusca. Methods: The fish were collected between September and November 2010 from a qanat in Birjand. They were exposed to two types treatments with copper (0.25 and 0.75 mg/L for a period of 41 days. The fish under study were exposed to the above-mentioned sub-lethal concentrations separately for 14 and 21 days (accumulation period. At the end of this period, the remaining fish were kept in tap water (elimination period for 31 and 41 days. Results: The findings showed that the accumulation of copper in lower and higher sub-lethal concentrations was higher in kidney as the mean accumulation of copper on day 21 was 1.9±0.1 μg/g and 2.93±0.47 μg/g respectively, in 0.25 μg/g and 0.75 μg/g concentrations. On the other hand, the results also showed that the depuration level of copper in the given concentrations was higher in liver than kidney. The bioaccumulation and depuration of copper significantly increased in the kidney and liver of C. fusca (P<0.01. Conclusion: Based on the present work, it is concluded that C. fusca has a potential for the rapid accumulation and depuration of copper in freshwater. Also, the results indicate that the fish C. fusca, as representative fish species in the East of Iran, can be a useful bioindicator organism of water contamination with copper.

  9. A Qualitative Meta-Analysis Reveals Consistent Effects of Atrazine on Freshwater Fish and Amphibians

    Science.gov (United States)

    Rohr, Jason R.; McCoy, Krista A.

    2010-01-01

    Objective The biological effects of the herbicide atrazine on freshwater vertebrates are highly controversial. In an effort to resolve the controversy, we conducted a qualitative meta-analysis on the effects of ecologically relevant atrazine concentrations on amphibian and fish survival, behavior, metamorphic traits, infections, and immune, endocrine, and reproductive systems. Data sources We used published, peer-reviewed research and applied strict quality criteria for inclusion of studies in the meta-analysis. Data synthesis We found little evidence that atrazine consistently caused direct mortality of fish or amphibians, but we found evidence that it can have indirect and sublethal effects. The relationship between atrazine concentration and timing of amphibian metamorphosis was regularly nonmonotonic, indicating that atrazine can both accelerate and delay metamorphosis. Atrazine reduced size at or near metamorphosis in 15 of 17 studies and 14 of 14 species. Atrazine elevated amphibian and fish activity in 12 of 13 studies, reduced antipredator behaviors in 6 of 7 studies, and reduced olfactory abilities for fish but not for amphibians. Atrazine was associated with a reduction in 33 of 43 immune function end points and with an increase in 13 of 16 infection end points. Atrazine altered at least one aspect of gonadal morphology in 7 of 10 studies and consistently affected gonadal function, altering spermatogenesis in 2 of 2 studies and sex hormone concentrations in 6 of 7 studies. Atrazine did not affect vitellogenin in 5 studies and increased aromatase in only 1 of 6 studies. Effects of atrazine on fish and amphibian reproductive success, sex ratios, gene frequencies, populations, and communities remain uncertain. Conclusions Although there is much left to learn about the effects of atrazine, we identified several consistent effects of atrazine that must be weighed against any of its benefits and the costs and benefits of alternatives to atrazine use. PMID

  10. Lead toxicity on non-specific immune mechanisms of freshwater fish Channa punctatus.

    Science.gov (United States)

    Paul, Nilantika; Chakraborty, Samujjwal; Sengupta, Mahuya

    2014-07-01

    Lead has no known role in the body that is physiologically relevant, and its harmful effects are myriad. Lead from the atmosphere and soil ends up in water bodies thus affecting the aquatic organisms. This situation has thus prompted numerous investigations on the effects of this metal on the biological functions of aquatic organisms, particularly on immune mechanisms in fish. This paper addresses the immunotoxicologic effects of lead acetate in intestinal macrophages of freshwater fish Channa punctatus. Fish were exposed to lead acetate (9.43mg/l) for 4 days. When checked for its effects on macrophages, it was noted that lead interfered with bacterial phagocytosis, intracellular killing capacity and cell adhesion as well as inhibited release of antimicrobial substances like nitric oxide (NO) and myeloperoxidase (MPO). On giving bacterial challenge with Staphylococcus aureus to intestinal macrophages of both control and lead treated groups, the macrophages showed significantly higher concentration of viable bacteria in the intracellular milieu in lead treated group as compared to control. We also report that in vivo exposure to lead acetate inhibits phagocytosis, which is evident from a reduced phagocytic index of treated group from that of the control. The amount of MPO and NO released by the control cells was also reduced significantly upon in vivo lead treatment. The property of antigenic adherence to the macrophage cell membrane, a vital process in phagocytosis, was significantly decreased in the treated group as compared to control. Severe damage in intestinal epithelium, disarrangement and fragmentation of mucosal foldings was observed in lead treated group when compared with the untreated group. The present results also showed decreased tumor necrosis factor-alpha (TNF-α) level upon metal exposure in sera as well as cell lysate of lead exposed fish thus, implicating both MAPK signaling pathways as well as NFκβ signaling. We thus conclude that lead affects

  11. Using Historical Atlas Data to Develop High-Resolution Distribution Models of Freshwater Fishes.

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    Jian Huang

    Full Text Available Understanding the spatial pattern of species distributions is fundamental in biogeography, and conservation and resource management applications. Most species distribution models (SDMs require or prefer species presence and absence data for adequate estimation of model parameters. However, observations with unreliable or unreported species absences dominate and limit the implementation of SDMs. Presence-only models generally yield less accurate predictions of species distribution, and make it difficult to incorporate spatial autocorrelation. The availability of large amounts of historical presence records for freshwater fishes of the United States provides an opportunity for deriving reliable absences from data reported as presence-only, when sampling was predominantly community-based. In this study, we used boosted regression trees (BRT, logistic regression, and MaxEnt models to assess the performance of a historical metacommunity database with inferred absences, for modeling fish distributions, investigating the effect of model choice and data properties thereby. With models of the distribution of 76 native, non-game fish species of varied traits and rarity attributes in four river basins across the United States, we show that model accuracy depends on data quality (e.g., sample size, location precision, species' rarity, statistical modeling technique, and consideration of spatial autocorrelation. The cross-validation area under the receiver-operating-characteristic curve (AUC tended to be high in the spatial presence-absence models at the highest level of resolution for species with large geographic ranges and small local populations. Prevalence affected training but not validation AUC. The key habitat predictors identified and the fish-habitat relationships evaluated through partial dependence plots corroborated most previous studies. The community-based SDM framework broadens our capability to model species distributions by innovatively

  12. Improving disease prevention and treatment in controlled fish culture

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    Terech-Majewska Elżbieta

    2016-09-01

    Full Text Available The aim of the work was to evaluate long-term results of studies focusing on improving methods for preventing and treating fish diseases using selected natural and syntetic immunomodulators and vaccines in fish culture. Simultaneously, attention is drawn to infectious or environmental threats against which appropriately composed immunoprophylaxis can be used in production cycles. Fish culture is intensifying in Poland and globally, which means that the role of prevention and well-designed prophylaxis is of increasing significance to the prevention and treatment of fish diseases. Currently, 33 fish species are cultured in Poland as stocking material or for production. The primary methods for preventing diseases in controlled fish culture are ensuring the welfare of fish and other prophylactic methods, including immunoprophylaxis. Many infectious and non-infectious threats that can cause direct losses and limit fish culture are present in the aquatic environment. Fish diseases generally stem from the simultaneous action of many factors that coincide and are difficult to distinguish. Pesticides (organochlorine insecticides, organophosphorus herbicides, aromatic hydrocarbons, pentachlorophenol, heavy metals, and chemotherapeutics are particularly toxic to fish. Biodegradation, which is continual in aquatic environments, is a process by which toxic and other substances that negatively affect fish become bioavailable and impact the immune system, the functioning of which is a specific bioindicator of environmental quality. Innate immunity plays a key role in the defense against disadvantageous factors, which also include pathogens. Immunomodulation methods can protect resistance mechanisms, thereby increasing disease prevention and treatment in controlled fish culture.

  13. Whole-body calcium flux rates in cichlid teleost fish Oreochromis mossambicus adapted to freshwater

    Energy Technology Data Exchange (ETDEWEB)

    Flik, G.; Fenwick, J.C.; Kolar, Z.; Mayer-Gostan, N.; Wendelaar Bonga, S.E.

    1985-10-01

    Radiotracer techniques were used to measure influx and efflux rates of CaS in freshwater-adapted Oreochromis mossambicus. The influx rate of CaS is related to body weight (W) as Fin = 50W0.805 nmol CaS /h. For a 20-g fish the calculated influx rate was 558 nmol CaS /h, and this was attributed largely to extraintestinal uptake since the drinking rate was estimated to be only 28 microliter water/h, which corresponds to an intake of 22.4 nmol CaS /h. The CaS efflux rate was calculated using the initial rate of appearance of radiotracer in the ambient water and the specific activity of plasma CaS . Tracer efflux rates were constant over 6-8 h, which indicated that there was no substantial loss of tracer in either the urine or the feces because this would have resulted in random bursts of tracer loss. Efflux rates then primarily represent integumentary and presumably branchial efflux rates. The efflux rate of CaS is related to body weight as Fout = 30W0.563 nmol CaS /h, which means an efflux rate of 162 nmol CaS /h for a 20-g fish. The net whole-body CaS influx, calculated as Fnet = Fin - Fout, was 396 nmol/h for a 20-g fish, which proves that the ambient water is an important source of CaS .

  14. Radioactive cesium accumulation in freshwater fishes after the Fukushima nuclear accident.

    Science.gov (United States)

    Arai, Takaomi

    2014-01-01

    The Fukushima Daiichi Nuclear Power Plant (F1NPP) accident released large amounts of radioactive substances into the environment and contaminated the terrestrial and marine ecosystems in East Japan. The unpredicted nuclear accident is of global concern for human health and ecosystems. Investigations of radionuclides in the local environments were performed shortly after the accident began; however the temporal and spatial effects and variations in the released radionuclides on the natural environment remain unclear. In the present study, three-year (May 2011 to March 2014) fluctuations and accumulations of total Cs, (134)Cs and (137)Cs in freshwater fishes in Fukushima prefecture after the F1NPP accident were examined. The total Cs, (134)Cs and (137)Cs concentrations decreased gradually during the three-year period that followed the F1NPP accident. However higher levels, i.e., exceeding 100 Bq kg(-1), which is the interim limit of radiocesium level in Japan, were detected in several fish species. Radiocesium accumulation patterns in fishes in Fukushima prefecture varied between regions and corresponded to the environmental radiocesium levels in the Fukushima region. These radionuclides are widely distributed and remain in the natural environment. Moreover, a fresh input of radiocesium substances from the F1NPP site into the terrestrial environment remains.

  15. The trace element analysis in freshwater fish species, water and sediment in Iyidere stream (Rize-Turkey).

    Science.gov (United States)

    Verep, Bulent; Mutlu, Cengiz; Apaydin, Gokhan; Cevik, Ugur

    2012-07-15

    Many environmental problems like dam construction, agricultural debris, flooding and industrial establishments threaten Iyidere stream (Rize, Turkey) on the southeastern coast of the Black Sea (Turkey). The trace element concentrations in water, fish and sediments in lyidere stream (Rize, Turkey) were investigated in this study. The concentration of six different elements in ten freshwater fish species and sediment was determined using energy dispersive X-ray fluorescence method. A radioisotope excited X-ray fluorescence analysis using the method of multiple standard addition is applied for the elemental analysis of fish and sediments. Water samples for trace metals were analyzed using standard spectrophotometry methods. A qualitative analysis of spectral peaks showed that ten different freshwater fish samples (Chondrostoma colchicum, Chalcalburnus chalcoides, Salmo trutta labrax, Alburnoides bipunctatus, Leuciscus cephalus, Barbus taurus escherichia, Capoeta tinca, Neogobius kessleri, Rutilus frisii, Lampetra lanceolata) and sediment contained phosphorus (P), sulphur (S), chlorine (Cl), potassium (K), calcium (Ca) and titanium (Ti). Heavy metals as toxic elements for biota (Pb, Cd, Hg, Zn and Mn etc.) were not detected in fish, water and sediments. Thus, It can be declared that freshwater fish of Iyidere does not contains health risks for consumers in terms of metal pollution.

  16. Levels and body distribution of polybrominated diphenyl ethers (PBDEs) and hexabromocyclododecanes (HBCDs) in freshwater fishes from the Yangtze River, China.

    Science.gov (United States)

    Xian, Qiming; Ramu, Karri; Isobe, Tomohiko; Sudaryanto, Agus; Liu, Xiaohua; Gao, Zishen; Takahashi, Shin; Yu, Hongxia; Tanabe, Shinsuke

    2008-03-01

    Polybrominated diphenyl ethers (PBDEs) and hexabromocyclododecanes (HBCDs) were determined in muscle, liver and eggs of freshwater fishes from the lower reach of the Yangtze River, China. The present study is the first to report HBCD concentrations in the environment of China. The concentrations of PBDEs and HBCDs in muscle of freshwater fishes from the Yangtze River ranged from 18 to 1100ng/g and 12 to 330ng/g lipid weight (wt.), respectively. When compared with other regions of the world, the contamination of PBDEs in biota could be regarded as moderate, whereas contamination of HBCDs in biota was relatively high. The PBDE congener profiles in fishes of the present study were markedly different from those observed in freshwater and marine fishes from other regions of the world. In the present study, BDE-15, BDE-28 and BDE-47 were the predominant congeners in the fishes. This particular congener profile in fishes from the Yangtze River revealed that a specific commercial PBDE formulation (probably made in China) might have been used in the Yangtze River Delta region.

  17. High level multiple antibiotic resistance among fish surface associated bacterial populations in non-aquaculture freshwater environment.

    Science.gov (United States)

    Ozaktas, Tugba; Taskin, Bilgin; Gozen, Ayse G

    2012-12-01

    Freshwater fish, Alburnus alburnus (bleak), were captured from Lake Mogan, situated in Ankara, during spring. The surface mucus of the fish was collected and associated bacteria were cultured and isolated. By sequencing PCR-amplified 16S RNA encoding genes, the isolates were identified as members of 12 different genera: Acinetobacter, Aeromonas, Bacillus, Brevundimonas, Gordonia, Kocuria, Microbacterium, Mycobacterium, Pseudomonas, Rhodococcus, and Staphylococcus, in addition to one strain that was unidentified. The mucus-dwelling bacterial isolates were tested for resistance against ampicillin, kanamycin, streptomycin and chloramphenicol. About 95% of the isolates were found to be resistant to ampicillin, 93% to chloramphenicol, and 88% to kanamycin and streptomycin. A Microbacterium oxydans and the unidentified environmental isolate were resistant to all four antibiotics tested at very high levels (>1600 μg/ml ampicillin and streptomycin; >1120 μg/ml kanamycin; >960 μg/ml chloramphenicol). Only a Kocuria sp. was sensitive to all four antibiotics at the lowest concentrations tested (3.10 μg/ml ampicillin and streptomycin; 2.15 μg/ml kanamycin; 1.85 μg/ml chloramphenicol). The rest of the isolates showed different resistance levels. Plasmid isolations were carried out to determine if the multiple antibiotic resistance could be attributed to the presence of plasmids. However, no plasmid was detected in any of the isolates. The resistance appeared to be mediated by chromosome-associated functions. This study indicated that multiple antibiotic resistance at moderate to high levels is common among the current phenotypes of the fish mucus-dwelling bacterial populations in this temperate, shallow lake which has not been subjected to any aquaculturing so far but under anthropogenic effect being in a recreational area.

  18. Detection of Vibrio Species Isolated from Ornamental Guppy Fish in Kashan, Isfahan, Iran Fish culturing Pounds

    OpenAIRE

    Samira Kiani; Nafiseh Sadat Naghavi; Alireza Nazari

    2016-01-01

    Introduction: Gram-negative bacteria are the most pathogenic bacteria for marine organisms including ornamental fish. Materials and methods: In the present study Vibrio species isolated from ornamental guppy fish in Kashan, Isfahan, Iran fish ponds and were detected according to molecular detection and genetic alignment. Liver, kidney, skin, brain and gill samples were taken from ornamental guppy fish in Kashan, Isfahan, Iran. Samples were cultured on enriched culture media and purificati...

  19. Laboratory Studies of the Effects of Static and Variable Magnetic Fields on Freshwater Fish

    Energy Technology Data Exchange (ETDEWEB)

    Cada, Glenn F [ORNL; Bevelhimer, Mark S [ORNL; Fortner, Allison M [ORNL; Riemer, Kristina P [ORNL; Schweizer, Peter E [ORNL

    2012-04-01

    benthic invertebrates (Gill et al. 2005, 2009). It is known that numerous marine and freshwater organisms are sensitive to electrical and magnetic fields, often depending on them for such diverse activities as prey location and navigation (DOE 2009; Normandeau et al. 2011). Despite the wide range of aquatic organisms that are sensitive to EMF and the increasing numbers of underwater electrical transmitting cables being installed in rivers and coastal waters, little information is available to assess whether animals will be attracted, repelled, or unaffected by these new sources of EMF. This knowledge gap is especially significant for freshwater systems, where electrosensitive organisms such as paddlefish and sturgeon may interact with electrical transmission cables. We carried out a series of laboratory experiments to test the sensitivity of freshwater fish and invertebrates to the levels of EMF that are expected to be produced by HK projects in rivers. In this context, EM fields are likely to be emitted primarily by generators in the water column and by transmission cables on or buried in the substrate. The HK units will be located in areas of high-velocity waters that are used as only temporary habitats for most riverine species, so long-term exposure of fish and benthic invertebrates to EMF is unlikely. Rather, most aquatic organisms will be briefly exposed to the fields as they drift downstream or migrate upstream. Because the exposure of most aquatic organisms to EMF in a river would be relatively brief and non-lethal, we focused our investigations on detecting behavioral effects. For example, attraction to the EM fields could result in prolonged exposures to the fields or the HK rotor. On the other hand, avoidance reactions might hinder upstream migrations of fish. The experiments reported here are a continuation of studies begun in FY 2010, which focused on the potential effects of static magnetic fields on snails, clams, and fathead minnows (Cada et al. 2011

  20. "Freshwater killer whales": beaching behavior of an alien fish to hunt land birds.

    Directory of Open Access Journals (Sweden)

    Julien Cucherousset

    Full Text Available The behavioral strategies developed by predators to capture and kill their prey are fascinating, notably for predators that forage for prey at, or beyond, the boundaries of their ecosystem. We report here the occurrence of a beaching behavior used by an alien and large-bodied freshwater predatory fish (Silurus glanis to capture birds on land (i.e. pigeons, Columbia livia. Among a total of 45 beaching behaviors observed and filmed, 28% were successful in bird capture. Stable isotope analyses (δ(13C and δ(15N of predators and their putative prey revealed a highly variable dietary contribution of land birds among individuals. Since this extreme behavior has not been reported in the native range of the species, our results suggest that some individuals in introduced predator populations may adapt their behavior to forage on novel prey in new environments, leading to behavioral and trophic specialization to actively cross the water-land interface.

  1. Trematode diversity in freshwater fishes of the Globe I: 'Old World'.

    Science.gov (United States)

    Scholz, Tomáš; Besprozvannykh, Vladimir V; Boutorina, Tamara E; Choudhury, Anindo; Cribb, Thomas H; Ermolenko, Alexey V; Faltýnková, Anna; Shedko, Marina B; Shimazu, Takeshi; Smit, Nico J

    2016-03-01

    In this paper, we review, continent by continent, the trematode fauna of freshwater fishes of the 'Old World', a vast area consisting of the Palaearctic, Ethiopian, Oriental and Australasian zoogeographical regions. Knowledge of this fauna is highly uneven and clearly incomplete for almost all regions, sometimes dramatically so. Although the biggest problem remains the completion of the 'first pass' of alpha taxonomy, there are in addition great problems relating to biogeography and elucidation of life-cycles. For the latter, molecular data, i.e. matching DNA sequences of larval stages and corresponding adults, may represent a powerful tool that should be used in future studies. Another challenging problem represents the existence of cryptic species and, in particular, considerable decrease of experts in taxonomy and life-cycles of trematodes.

  2. Freshwater Killer Whales”: Beaching Behavior of an Alien Fish to Hunt Land Birds

    Science.gov (United States)

    Cucherousset, Julien; Boulêtreau, Stéphanie; Azémar, Frédéric; Compin, Arthur; Guillaume, Mathieu; Santoul, Frédéric

    2012-01-01

    The behavioral strategies developed by predators to capture and kill their prey are fascinating, notably for predators that forage for prey at, or beyond, the boundaries of their ecosystem. We report here the occurrence of a beaching behavior used by an alien and large-bodied freshwater predatory fish (Silurus glanis) to capture birds on land (i.e. pigeons, Columbia livia). Among a total of 45 beaching behaviors observed and filmed, 28% were successful in bird capture. Stable isotope analyses (δ13C and δ15N) of predators and their putative prey revealed a highly variable dietary contribution of land birds among individuals. Since this extreme behavior has not been reported in the native range of the species, our results suggest that some individuals in introduced predator populations may adapt their behavior to forage on novel prey in new environments, leading to behavioral and trophic specialization to actively cross the water-land interface. PMID:23227213

  3. "Freshwater killer whales": beaching behavior of an alien fish to hunt land birds.

    Science.gov (United States)

    Cucherousset, Julien; Boulêtreau, Stéphanie; Azémar, Frédéric; Compin, Arthur; Guillaume, Mathieu; Santoul, Frédéric

    2012-01-01

    The behavioral strategies developed by predators to capture and kill their prey are fascinating, notably for predators that forage for prey at, or beyond, the boundaries of their ecosystem. We report here the occurrence of a beaching behavior used by an alien and large-bodied freshwater predatory fish (Silurus glanis) to capture birds on land (i.e. pigeons, Columbia livia). Among a total of 45 beaching behaviors observed and filmed, 28% were successful in bird capture. Stable isotope analyses (δ(13)C and δ(15)N) of predators and their putative prey revealed a highly variable dietary contribution of land birds among individuals. Since this extreme behavior has not been reported in the native range of the species, our results suggest that some individuals in introduced predator populations may adapt their behavior to forage on novel prey in new environments, leading to behavioral and trophic specialization to actively cross the water-land interface.

  4. Taxonomic distinctness and richness of helminth parasite assemblages of freshwater fishes in Mexican hydrological basins.

    Directory of Open Access Journals (Sweden)

    Benjamín Quiroz-Martínez

    Full Text Available In this paper, we analyse the distributional patterns of adult helminth parasites of freshwater fishes with respect to the main hydrological basins of Mexico. We use the taxonomic distinctness and the variation in taxonomic distinctness to explore patterns of parasite diversity and how these patterns change between zoogeographical regions. We address questions about the factors that determine the variation of observed diversity of helminths between basins. We also investigate patterns of richness, taxonomic distinctness and distance decay of similarity amongst basins. Our analyses suggest that the evolution of the fauna of helminth parasites in Mexico is mostly dominated by independent host colonization events and that intra--host speciation could be a minor factor explaining the origin of this diversity. This paper points out a clear separation between the helminth faunas of northern--nearctic and southern--neotropical components in Mexican continental waters, suggesting the availability of two distinct taxonomic pools of parasites in Mexican drainage basins. Data identifies Mexican drainage basins as unities inhabited by freshwater fishes, hosting a mixture of neotropical and nearctic species, in addition, data confirms neotropical and neartic basins/helminth faunas. The neotropical basins of Mexico are host to a richest and more diversified helminth fauna, including more families, genera and species, compared to the less rich and less diverse helminth fauna in the nearctic basins. The present analysis confirms distance--decay as one of the important factors contributing to the patterns of diversity observed. The hypothesis that helminth diversity could be explained by the ichthyological diversity of the basin received no support from present analysis.

  5. Defining conservation priorities for freshwater fishes according to taxonomic, functional, and phylogenetic diversity

    Science.gov (United States)

    Strecker, Angela; Olden, Julian D.; Whittier, Joanna B.; Paukert, Craig P.

    2011-01-01

    To date, the predominant use of systematic conservation planning has been to evaluate and conserve areas of high terrestrial biodiversity. Although studies in freshwater ecosystems have received recent attention, research has rarely considered the potential trade-offs between protecting different dimensions of biodiversity and the ecological processes that maintain diversity. We provide the first systematic prioritization for freshwaters (focusing on the highly threatened and globally distinct fish fauna of the Lower Colorado River Basin, USA) simultaneously considering scenarios of: taxonomic, functional, and phylogenetic diversity; contemporary threats to biodiversity (including interactions with nonnative species); and future climate change and human population growth. There was 75% congruence between areas of highest conservation priority for different aspects of biodiversity, suggesting that conservation efforts can concurrently achieve strong complementarity among all types of diversity. However, sizable fractions of the landscape were incongruent across conservation priorities for different diversity scenarios, underscoring the importance of considering multiple dimensions of biodiversity and highlighting catchments that contribute disproportionately to taxonomic, functional, and phylogenetic diversity in the region. Regions of projected human population growth were not concordant with conservation priorities; however, higher human population abundance will likely have indirect effects on native biodiversity by increasing demand for water. This will come in direct conflict with projected reductions in precipitation and warmer temperatures, which have substantial overlap with regions of high contemporary diversity. Native and endemic fishes in arid ecosystems are critically endangered by both current and future threats, but our results highlight the use of systematic conservation planning for the optimal allocation of limited resources that incorporates

  6. Taxonomic distinctness and richness of helminth parasite assemblages of freshwater fishes in Mexican hydrological basins.

    Science.gov (United States)

    Quiroz-Martínez, Benjamín; Salgado-Maldonado, Guillermo

    2013-01-01

    In this paper, we analyse the distributional patterns of adult helminth parasites of freshwater fishes with respect to the main hydrological basins of Mexico. We use the taxonomic distinctness and the variation in taxonomic distinctness to explore patterns of parasite diversity and how these patterns change between zoogeographical regions. We address questions about the factors that determine the variation of observed diversity of helminths between basins. We also investigate patterns of richness, taxonomic distinctness and distance decay of similarity amongst basins. Our analyses suggest that the evolution of the fauna of helminth parasites in Mexico is mostly dominated by independent host colonization events and that intra--host speciation could be a minor factor explaining the origin of this diversity. This paper points out a clear separation between the helminth faunas of northern--nearctic and southern--neotropical components in Mexican continental waters, suggesting the availability of two distinct taxonomic pools of parasites in Mexican drainage basins. Data identifies Mexican drainage basins as unities inhabited by freshwater fishes, hosting a mixture of neotropical and nearctic species, in addition, data confirms neotropical and neartic basins/helminth faunas. The neotropical basins of Mexico are host to a richest and more diversified helminth fauna, including more families, genera and species, compared to the less rich and less diverse helminth fauna in the nearctic basins. The present analysis confirms distance--decay as one of the important factors contributing to the patterns of diversity observed. The hypothesis that helminth diversity could be explained by the ichthyological diversity of the basin received no support from present analysis.

  7. Toxicity, sublethal effects, and potential modes of action of select fungicides on freshwater fish and invertebrates

    Science.gov (United States)

    Elskus, Adria A.

    2012-01-01

    Despite decades of agricultural and urban use of fungicides and widespread detection of these pesticides in surface waters, relatively few data are available on the effects of fungicides on fish and invertebrates in the aquatic environment. Nine fungicides are reviewed in this report: azoxystrobin, boscalid, chlorothalonil, fludioxonil, myclobutanil, fenarimol, pyraclostrobin, pyrimethanil, and zoxamide. These fungicides were identified as emerging chemicals of concern because of their high or increasing global use rates, detection frequency in surface waters, or likely persistence in the environment. A review of the literature revealed significant sublethal effects of fungicides on fish, aquatic invertebrates, and ecosystems, including zooplankton and fish reproduction, fish immune function, zooplankton community composition, metabolic enzymes, and ecosystem processes, such as leaf decomposition in streams, among other biological effects. Some of these effects can occur at fungicide concentrations well below single-species acute lethality values (48- or 96-hour concentration that effects a response in 50 percent of the organisms, that is, effective concentration killing 50 percent of the organisms in 48 or 96 hours) and chronic sublethal values (for example, 21-day no observed adverse effects concentration), indicating that single-species toxicity values may dramatically underestimate the toxic potency of some fungicides. Fungicide modes of toxic action in fungi can sometimes reflect the biochemical and (or) physiological effects of fungicides observed in vertebrates and invertebrates; however, far more studies are needed to explore the potential to predict effects in nontarget organisms based on specific fungicide modes of toxic action. Fungicides can also have additive and (or) synergistic effects when used with other fungicides and insecticides, highlighting the need to study pesticide mixtures that occur in surface waters. For fungicides that partition to

  8. Inland Ertebølle Culture: the importance of aquatic resources and the freshwater reservoir effect in radiocarbon dates from pottery food crusts

    Directory of Open Access Journals (Sweden)

    Bente Philippsen

    2014-11-01

    Full Text Available The Ertebølle culture is a late Mesolithic hunter-gatherer-fisher culture in southern Scandinavia, northern Germany and Poland. Archaeological finds as well as scientific analyses of humans and their artefacts indicate the great importance of aquatic resources, both marine and freshwater, to Ertebølle subsistence. In northern Germany, modern freshwater fish samples can have very high apparent radiocarbon ages (up to 3000 years. If such dramatic 'freshwater reservoir effects' also existed during the late Mesolithic, they could lead to artificially old radiocarbon dates for the bones of Ertebølle humans and domestic dogs, and for carbonised food crusts on cooking pots. Conversely, if we can demonstrate radiocarbon age 'offsets' in such samples, we can often attribute them to the exploitation of freshwater food resources. This article discusses methods of identifying freshwater resources in prehistoric pottery, including radiocarbon reservoir effects. We consider the results of radiocarbon, stable isotope and elemental analyses of food crusts on prehistoric pottery from four sites in the Alster and Trave valleys: Kayhude, Schlamersdorf, Bebensee and Seedorf.

  9. Nematode and mercury content in freshwater fish belonging to different trophic levels.

    Science.gov (United States)

    Olivero-Verbel, Jesus; Caballero-Gallardo, Karina

    2013-06-01

    Fish are a protein source for many people in Colombia. However, environmental pollution of some aquatic ecosystems may pose health risks to humans. The aim of this study was to assess the levels of total mercury (T-Hg) in muscle and their relationship with nematode infections in fish from Dique Channel, a freshwater ecosystem located Northern Colombia. Eight hundred ninety fish specimens belonging to 13 different species were collected. T-Hg concentration was measured using atomic absorption spectroscopy, previous electrothermal atomization. Nematodes were identified as Contracaecum sp. Species such as Hoplias malabaricus and Sorubim cuspicaudus presented the highest values for Hg and parasite infection (0.09 ± 0.01, 0.12 ± 0.02 μg/g; prevalence 100, 100 %, respectively), whereas the lowest were detected in Prochilodus magdalenae (0.02 ± 0.002 μg/g; 0 %). Pooled data revealed a high correlation between trophic level and parasite abundance (ρ = 0.771; P = 0.002) as well as with T-Hg (ρ = 0.786; P < 0.001). The overall correlation between parasite abundance and T-Hg was moderately to low but positive (ρ = 0.217; P < 0.001). However, when individual species were considered, pair relationships between parasite abundance, morphometric parameters, and Hg concentration, varied between positive and negative values. These data suggest the presence of nematodes is determined by the trophic level of the fish species, similarly to what occurs with Hg. Moreover, the co-occurrence of these two stressors involves different types of interactions with morphometric variables that are species-specific. These observations open new doors to the understanding of the interaction between chemical pollutants and organisms.

  10. Detection of mycobacteria in aquarium fish in Slovenia by culture and molecular methods.

    Science.gov (United States)

    Pate, M; Jencic, V; Zolnir-Dovc, M; Ocepek, M

    2005-04-06

    Thirty-five aquarium fish were investigated for the presence of mycobacteria by culture and molecular methods. The following species were examined: goldfish Carassius auratus auratus, guppy Poecilia reticulata, 4 three-spot gourami Trichogaster trichopterus, dwarf gourami Colisa lalia, Siamese fighting fish Betta splendens, freshwater angelfish Pterophyllum scalare, African cichlid fish Cichlidae spp., cichlid fish Microgeophagus altispinosus, cichlid fish Pseudotropheus lombardoi, blue streak hap Labidochromis caeruleus, sterlet Acipenser ruthenus, southern platyfish Xiphophorus maculatus, and catfish Corydoras spp. Isolates of mycobacteria were obtained in 29 cases (82.9%). Two specimens were positive using Ziehl-Neelsen (ZN) staining, but the cultivation failed. Four specimens were both ZN- and culture-negative. On the basis of GenoType Mycobacterium assay (Hain Life-science) and restriction enzyme analysis of the amplified products (PCR-RFLP), 23 isolates (79.3%) were identified: 7 as Mycobacterium fortuitum, 6 as M. gordonae, 6 as M. marinum, 3 as M. chelonae, and 1 as M. peregrinum. Five isolates remained unidentified (Mycobacterium spp.). One case probably represented a mixed infection (M. marinum/M. fortuitum). Since M. marinum infections are also detected in humans, the significance of mycobacteria in aquarium fish should not be overlooked.

  11. Prevalence and antimicrobial resistance of Salmonella spp. in raw retail frozen imported freshwater fish to Eastern Province of Saudi Arabia.

    Science.gov (United States)

    Elhadi, Nasreldin

    2014-03-01

    To determine the proportion of imported frozen fish contaminated with Salmonella among retail food stores and supermarkets in the Eastern Province of Saudi Arabia. A total of 223 frozen freshwater fish purchased from different supermarkets and grocery stores were analyzed for the presence of foodborne pathogen Salmonella. The isolation of Salmonella was determined and confirmed by using the methods of US Food and Drug Administration's Bacteriological Analytical Manual, CHROMagar Salmonella plus, biochemical tests and API 20E strips. Antimicrobial susceptibilities of Salmonella isolates were determined by the disk diffusion method on Muller-Hinton agar, as described by Kirby-Bauer, in accordance with the guidelines of the Clinical and Laboratory Standards Institute. Out of the total 223 fish samples (20 of catfish, 18 of carfu, 20 of mirgal, 25 of milkfish, 35 of mackerel, 75 of tilapia, and 30 of rohu), 89 (39.9%) were tested positive for Salmonella. The prevalence of positive samples were reported for the freshwater fish of pangas (60.0%, n=12), carfu (27.7%, n=5), mirgal (35.0%, n=7), milkfish (52.0%, n=13), mackerel (31.4 %, n=11), tilapia imported from Thailand (64.0%, n=16), tilapia imported from India (28.0%, n=14), rohu imported from Thailand (26.6%, n=4) and rohu imported from Myanmar (46.6%, n=7). A total of 140 isolates of Salmonella spp. were yielded from at least seven different types of frozen freshwater fish imported from 5 different countries and were tested for their susceptibility to 16 selected antimicrobial agents. The highest antibiotic resistance was observed to tetracycline (90.71%) followed by ampicillin (70%) and amoxicillin-clavulanic acid (45%). The obtained results of this study shows that these raw retail imported frozen freshwater fish are contaminated with potentially pathogenic Salmonella spp. And the study recommend and suggest that there is a need for adequate consumer measures.

  12. Prevalence and antimicrobial resistance of Salmonella spp. in raw retail frozen imported freshwater fish to Eastern Province of Saudi Arabia

    Institute of Scientific and Technical Information of China (English)

    Nasreldin Elhadi

    2014-01-01

    Objective:To determine the proportion of imported frozen fish contaminated with Salmonella among retail food stores and supermarkets in the Eastern Province of Saudi Arabia. Methods: A total of 223 frozen freshwater fish purchased from different supermarkets and grocery stores were analyzed for the presence of foodborne pathogen Salmonella. The isolation of Salmonella was determined and confirmed by using the methods of US Food and Drug Administration’s Bacteriological Analytical Manual, CHROMagar Salmonella plus, biochemical tests and API 20E strips. Antimicrobial susceptibilities of Salmonella isolates were determined by the disk diffusion method on Muller-Hinton agar, as described by Kirby-Bauer, in accordance with the guidelines of the Clinical and Laboratory Standards Institute. Results:Out of the total 223 fish samples (20 of catfish, 18 of carfu, 20 of mirgal, 25 of milkfish, 35 of mackerel, 75 of tilapia, and 30 of rohu), 89 (39.9%) were tested positive for Salmonella. The prevalence of positive samples were reported for the freshwater fish of pangas (60.0%, n=12), carfu (27.7%, n=5), mirgal (35.0%, n=7), milkfish (52.0%, n=13), mackerel (31.4 %, n=11), tilapia imported from Thailand (64.0%, n=16), tilapia imported from India (28.0%, n=14), rohu imported from Thailand (26.6%, n=4) and rohu imported from Myanmar (46.6%, n=7). A total of 140 isolates of Salmonella spp. were yielded from at least seven different types of frozen freshwater fish imported from 5 different countries and were tested for their susceptibility to 16 selected antimicrobial agents. The highest antibiotic resistance was observed to tetracycline (90.71%) followed by ampicillin (70%) and amoxicillin-clavulanic acid (45%). Conclusions: The obtained results of this study shows that these raw retail imported frozen freshwater fish are contaminated with potentially pathogenic Salmonella spp. And the study recommend and suggest that there is a need for adequate consumer measures.

  13. Functional diversity of the lateral line system among populations of a native Australian freshwater fish.

    Science.gov (United States)

    Spiller, Lindsey; Grierson, Pauline F; Davies, Peter M; Hemmi, Jan; Collin, Shaun P; Kelley, Jennifer L

    2017-06-15

    Fishes use their mechanoreceptive lateral line system to sense nearby objects by detecting slight fluctuations in hydrodynamic motion within their immediate environment. Species of fish from different habitats often display specialisations of the lateral line system, in particular the distribution and abundance of neuromasts, but the lateral line can also exhibit considerable diversity within a species. Here, we provide the first investigation of the lateral line system of the Australian western rainbowfish (Melanotaenia australis), a species that occupies a diversity of freshwater habitats across semi-arid northwest Australia. We collected 155 individuals from eight populations and surveyed each habitat for environmental factors that may contribute to lateral line specialisation, including water flow, predation risk, habitat structure and prey availability. Scanning electron microscopy and fluorescent dye labelling were used to describe the lateral line system in M. australis, and to examine whether the abundance and arrangement of superficial neuromasts (SNs) varied within and among populations. We found that the SNs of M. australis were present in distinct body regions rather than lines. The abundance of SNs within each body region was highly variable, and also differed among populations and individuals. Variation in SN abundance among populations was best explained by habitat structure and the availability of invertebrate prey. Our finding that specific environmental factors explain among-population variation in a key sensory system suggests that the ability to acquire sensory information is specialised for the particular behavioural needs of the animal. © 2017. Published by The Company of Biologists Ltd.

  14. Impact of Refrigerated Storage on Quality of Oil from Freshwater Jarko (Wallago attu Fish.

    Directory of Open Access Journals (Sweden)

    Nusrat N. Memon

    2010-12-01

    Full Text Available The effect of refrigerated storage on the quality of freshwater fish oil Jarko (Wallago attu was evaluated by measuring fatty acid profile, free fatty acids (FFA, peroxide value (PV, acid value (AV, sponification value (SV, iodine value (IV and poylene index (PI up to the time period of 120 days. After 120 days storage, mono unsaturated fatty acids (MUFA and polyunsaturated fatty acids (PUFA contents were decreased by 24.89% and 33.70%, respectively. While, saturated fatty acids (SFA content was found to be increased by 26.82%, against the actual value. The change in polyunsaturated fatty acids during refrigerated storage was measured by the PI value. The PI decreased during storage due to lipid oxidation, but remained nearly constant after 90th day of storage. The results of PV, AV and FFA demonstrates that Wallago attu fish oil remained acceptable for consumption for 60 days but eventually exceeded the recommended values after 60 days of refrigerated storage.

  15. Day and night trophic variations of dominant fish species in a lagoon influenced by freshwater seeps.

    Science.gov (United States)

    Arceo-Carranza, D; Vega-Cendejas, M E; Hernández de Santillana, M

    2013-01-01

    The aim of this study was to determine the trophic structure and nycthemeral variations in the diet of dominant fish species (Ariopsis felis, Bairdiella chrysoura, Micropogonias undulatus, Eucinostomus gula, Eucinostomus argenteus, Lagodon rhomboides and Sphoeroides testudineus) in Celestun Lagoon, a biosphere reserve located in the southern Gulf of Mexico, and influenced by freshwater seeps. A total of 1473 stomachs were analysed and nine trophic groups were recorded. Bray-Curtis analyses with analyses of similarity (ANOSIM) statistical tests were used to determine two groups of feeding guilds: zoobenthivores and omnivores, with significant differences between time and habitat. The relationships between fish feeding habits, size class and environmental variables were investigated using canonical correspondence analysis (CCA). Most of the species showed a low niche breadth with high specialization towards amphipod consumption, with the exception of L. rhomboides (0·60), which indicated generalist feeding. This study in a protected area is an important source of information for drawing up conservation policies in relation to the management of aquatic resources, and will aid in the establishment of priority areas for conservation.

  16. Endosulfan-mediated Biochemical Changes in the Freshwater Fish Clarias batrachus

    Institute of Scientific and Technical Information of China (English)

    G. TRIPATHI AND PRIYANKA VERMA

    2004-01-01

    Objective Endosulfan is an extremely toxic organochlorine pesticide to aquatic organisms which might be hampering fish health through impairment of metabolism sometimes leading to death.So an experimental protocol was designed to look at endosulfan effects on a number of selected biochemical endpoints as well as to develop a mechanistic understanding of biochemical effects of endosulfan in freshwater fish. Methods The adult freshwater catfish Clarias batrachus were collected and acclimatized to laboratory condition for two weeks prior to experimentation. The toxicity bioassay test of commercial grade endosulfan (35% EC) was conducted for 21 days to determine its initial lethal concentration. The fish were exposed to sublethal concentration of endosulfan (0.06 mg/L) for 21 days. Pesticide - withdrawal experiments were also performed to study recovery. Protein synthesis inhibitors were injected to know the possible mechanism of recovery. The specimens of C. batrachus were sacrificed and brain, liver and caudal white skeletal muscle were removed. Tissues were homogenized and fractions were obtained by differential centrifugation. The activities of citrate synthase (CS), glucose 6-phosphate dehydrogenase (G6-PDH) and lactate dehydrogease (LDH) were assayed spectrophotometrically. Similarly, DNA, RNA and protein content were measured as per standard procedure. Results The exposure of sublethal concentration of endosulfan decreased the activity of citrate synthase (CS) and glucose 6-phosphate dehydrogenase (G6-PDH) in the brain, liver and skeletal muscle of the freshwater catfish, C. batrachus. The brain lactate dehydrogenase (LDH) activity was also reduced in response to endosulfan toxicity. The maximum reduction in activities of these enzyme was 34%-43%. Withdrawal of endosulfan restored the enzyme activity to control level in all the three tissues. The recovery in enzyme activity appears to be due to dissociation of endosulfan or its metabolite(s) from the enzyme

  17. Laboratory Studies of the Short-term Responses of Freshwater Fish to Electromagnetic Fields

    Energy Technology Data Exchange (ETDEWEB)

    Bevelhimer, Mark S [ORNL; Cada, Glenn F [ORNL; Fortner, Allison M [ORNL; Schweizer, Peter E [ORNL; Riemer, Kristina P [ORNL

    2013-01-01

    Hydrokinetic energy technologies are being proposed as an environmentally preferred means of generating electricity from river and tidal currents. Among the potential issues that must be investigated in order to resolve environmental concerns are the effects on aquatic organisms of electromagnetic fields created by underwater generators and transmission cables. The behavioral responses of common freshwater fishes to static and variable electromagnetic fields (EMF) that may be emitted by hydrokinetic projects were evaluated in laboratory experiments. Various fish species were exposed to either static (DC) EMF fields created by a permanent bar magnet or variable (AC) EMF fields created by a switched electromagnet for 48 h, fish locations were recorded with a digital imaging system, and changes in activity level and distribution relative to the magnet position were quantified at 5-min intervals. Experiments with fathead minnows, redear sunfish, striped bass, lake sturgeon, and channel catfish produced mixed results. Except for fathead minnows there was no effect on activity level. Only redear sunfish and channel catfish exhibited a change in distribution relative to the position of the magnet with an apparent attraction to the EMF source. In separate experiments, rapid behavioral responses of paddlefish and lake sturgeon to onset of the AC field were recorded with high-speed video. Paddlefish did not react to a variable, 60-Hz magnetic field like that which would be emitted by an AC generator or cable, but lake sturgeon consistently responded to the variable, AC-generated magnetic field with a variety of altered swimming behaviors. These results will be useful for determining under what circumstances cables or generators need to be positioned to minimize interactions with sensitive species.

  18. Late Pleistocene fishes of the Tennessee River Basin: an analysis of a late Pleistocene freshwater fish fauna from Bell Cave (site ACb-2 in Colbert County, Alabama, USA

    Directory of Open Access Journals (Sweden)

    Stephen J. Jacquemin

    2016-02-01

    Full Text Available The Tennessee River Basin is considered one of the most important regions for freshwater biodiversity anywhere on the globe. The Tennessee River Basin currently includes populations of at least half of the described contemporary diversity of extant North American freshwater fishes, crayfish, mussel, and gastropod species. However, comparatively little is known about the biodiversity of this basin from the Pleistocene Epoch, particularly the late Pleistocene (∼10,000 to 30,000 years B.P. leading to modern Holocene fish diversity patterns. The objective of this study was to describe the fish assemblages of the Tennessee River Basin from the late Pleistocene using a series of faunas from locales throughout the basin documented from published literature, unpublished reports, and an undocumented fauna from Bell Cave (site ACb-2, Colbert County, AL. Herein we discuss 41 unequivocal taxa from 10 late Pleistocene localities within the basin and include a systematic discussion of 11 families, 19 genera, and 24 identifiable species (28 unequivocal taxa specific to the Bell Cave locality. Among the described fauna are several extirpated (e.g., Northern Pike Esox lucius, Northern Madtom Noturus stigmosus and a single extinct (Harelip Sucker Moxostoma lacerum taxa that suggest a combination of late Pleistocene displacement events coupled with more recent changes in habitat that have resulted in modern basin diversity patterns. The Bell Cave locality represents one of the most intact Pleistocene freshwater fish deposits anywhere in North America. Significant preservational, taphonomic, sampling, and identification biases preclude the identification of additional taxa. Overall, this study provides a detailed look into paleo-river ecology, as well as freshwater fish diversity and distribution leading up to the contemporary biodiversity patterns of the Tennessee River Basin and Mississippi River Basin as a whole.

  19. Late Pleistocene fishes of the Tennessee River Basin: an analysis of a late Pleistocene freshwater fish fauna from Bell Cave (site ACb-2) in Colbert County, Alabama, USA.

    Science.gov (United States)

    Jacquemin, Stephen J; Ebersole, Jun A; Dickinson, William C; Ciampaglio, Charles N

    2016-01-01

    The Tennessee River Basin is considered one of the most important regions for freshwater biodiversity anywhere on the globe. The Tennessee River Basin currently includes populations of at least half of the described contemporary diversity of extant North American freshwater fishes, crayfish, mussel, and gastropod species. However, comparatively little is known about the biodiversity of this basin from the Pleistocene Epoch, particularly the late Pleistocene (∼10,000 to 30,000 years B.P.) leading to modern Holocene fish diversity patterns. The objective of this study was to describe the fish assemblages of the Tennessee River Basin from the late Pleistocene using a series of faunas from locales throughout the basin documented from published literature, unpublished reports, and an undocumented fauna from Bell Cave (site ACb-2, Colbert County, AL). Herein we discuss 41 unequivocal taxa from 10 late Pleistocene localities within the basin and include a systematic discussion of 11 families, 19 genera, and 24 identifiable species (28 unequivocal taxa) specific to the Bell Cave locality. Among the described fauna are several extirpated (e.g., Northern Pike Esox lucius, Northern Madtom Noturus stigmosus) and a single extinct (Harelip Sucker Moxostoma lacerum) taxa that suggest a combination of late Pleistocene displacement events coupled with more recent changes in habitat that have resulted in modern basin diversity patterns. The Bell Cave locality represents one of the most intact Pleistocene freshwater fish deposits anywhere in North America. Significant preservational, taphonomic, sampling, and identification biases preclude the identification of additional taxa. Overall, this study provides a detailed look into paleo-river ecology, as well as freshwater fish diversity and distribution leading up to the contemporary biodiversity patterns of the Tennessee River Basin and Mississippi River Basin as a whole.

  20. Laboratory Studies of the Effects of Static and Variable Magnetic Fields on Freshwater Fish

    Energy Technology Data Exchange (ETDEWEB)

    Cada, Glenn F [ORNL; Bevelhimer, Mark S [ORNL; Fortner, Allison M [ORNL; Riemer, Kristina P [ORNL; Schweizer, Peter E [ORNL

    2012-04-01

    benthic invertebrates (Gill et al. 2005, 2009). It is known that numerous marine and freshwater organisms are sensitive to electrical and magnetic fields, often depending on them for such diverse activities as prey location and navigation (DOE 2009; Normandeau et al. 2011). Despite the wide range of aquatic organisms that are sensitive to EMF and the increasing numbers of underwater electrical transmitting cables being installed in rivers and coastal waters, little information is available to assess whether animals will be attracted, repelled, or unaffected by these new sources of EMF. This knowledge gap is especially significant for freshwater systems, where electrosensitive organisms such as paddlefish and sturgeon may interact with electrical transmission cables. We carried out a series of laboratory experiments to test the sensitivity of freshwater fish and invertebrates to the levels of EMF that are expected to be produced by HK projects in rivers. In this context, EM fields are likely to be emitted primarily by generators in the water column and by transmission cables on or buried in the substrate. The HK units will be located in areas of high-velocity waters that are used as only temporary habitats for most riverine species, so long-term exposure of fish and benthic invertebrates to EMF is unlikely. Rather, most aquatic organisms will be briefly exposed to the fields as they drift downstream or migrate upstream. Because the exposure of most aquatic organisms to EMF in a river would be relatively brief and non-lethal, we focused our investigations on detecting behavioral effects. For example, attraction to the EM fields could result in prolonged exposures to the fields or the HK rotor. On the other hand, avoidance reactions might hinder upstream migrations of fish. The experiments reported here are a continuation of studies begun in FY 2010, which focused on the potential effects of static magnetic fields on snails, clams, and fathead minnows (Cada et al. 2011

  1. Selenium:Mercury Molar Ratios in Freshwater Fish from Tennessee: Individual, Species, and Geographical Variations have Implications for Management

    Science.gov (United States)

    Burger, Joanna; Gochfeld, Michael; Jeitner, C.; Donio, M.; Pittfield, T.

    2014-01-01

    Vertebrates, including humans, can experience adverse effects from mercury consumed in fish. Humans often prefer large predatory fish that bioaccumulate high mercury levels. Recent attention has focused on the role of selenium countering mercury toxicity, but there is little research on the selenium:mercury molar ratios in freshwater fish. We examine selenium:mercury molar ratios in freshwater fish from Tennessee at Poplar Creek which receives ongoing inputs of mercury from the Department of Energy’s Oak Ridge Y-12 facility. Our objective was to determine variation of the ratios within species that might affect the protectiveness of selenium against mercury toxicity. Within species, the ratio was correlated significantly and positively with fish length only for two species. There was great individual variation in the selenium:mercury molar ratio within each species, except striped bass. The lack of a clear relationship between the selenium:mercury molar ratio and fish length, and the intraspecific variation, suggests that it would be difficult to use the molar ratio in predicting either the risk from mercury toxicity or in devising consumption advisories. PMID:22456727

  2. Assessing Potential Conservation and Restoration Areas of Freshwater Fish Fauna in the Indian River Basins.

    Science.gov (United States)

    Bhatt, Jay P; Manish, Kumar; Mehta, Rajender; Pandit, Maharaj K

    2016-05-01

    Conservation efforts globally are skewed toward terrestrial ecosystems. To date, conservation of aquatic ecosystems, in particular fish fauna, is largely neglected. We provide a country-wide assessment of Indian river ecosystems in order to identify and prioritize areas for protection and restoration of freshwater fish fauna. Using various biodiversity and anthropogenic attributes, coupled with tools of ecological modeling, we delineated areas for fish fauna conservation and restoration in the 20 major river basins of India. To do this, we used prioritization analyses and reserve selection algorithms to derive conservation value index (CVI) and vulnerability index (VI) of the river basins. CVI was estimated using endemicity, rarity, conservation value, and taxonomic singularity, while VI was estimated using a disturbance index derived from percent geographic area of the basin under human settlements, human population density, predominant land use, and total number of exotic fish species in each basin. The two indices, CVI and VI, were converted into geo-referenced maps, and each map was super-imposed onto species richness and forest cover maps, respectively. After superimposition, areas with high CVI and low VI shade intensities were delineated for conservation, while areas with high CVI and high VI shade intensities were demarcated for restoration. In view of the importance of freshwater fish for human livelihoods and consumption, and ecosystems of India's rivers, we call for urgent attention to the conservation of their fish fauna along with restoration of their degraded habitats.

  3. Fish abundances in shoreline habitats and submerged aquatic vegetation in a tidal freshwater embayment of the Potomac River.

    Science.gov (United States)

    Kraus, Richard T; Jones, R Christian

    2012-05-01

    Submerged aquatic vegetation (SAV) is considered an important habitat for juvenile and small forage fish species, but many long-term recruitment surveys do not effectively monitor fish communities in SAV. To better understand the impact of recent large increases of SAV on the fish community in tidal freshwater reaches of the Potomac River, we compared traditional seine sampling from shore with drop ring sampling of SAV beds (primarily Hydrilla) in a shallow water (depths, shoreline and SAV habitats in late summer of three different years (2007, 2008, and 2009). For the dominant species (Fundulus diaphanus, Lepomis macrochirus, Etheostoma olmstedi, Morone americana, Lepomis gibbosus, and Fundulus heteroclitus), density was nearly always higher in SAV, but overall, species richness was highest in shoreline habitats sampled with seines. Although historical monitoring of fish in Gunston Cove (and throughout Chesapeake Bay) is based upon seine sampling (and trawl sampling in deeper areas), the high densities of fish and larger areal extent of SAV indicated that complementary sampling of SAV habitats would produce more accurate trends in abundances of common species. Because drop ring samples cover much less area than seines and may miss rare species, a combination of methods that includes seine sampling is needed for biodiversity assessment. The resurgence of SAV in tidal freshwater signifies improving water quality, and methods we evaluated here support improved inferences about population trends and fish community structure as indicators of ecosystem condition.

  4. Environmental changes on freshwater fish communities in South America in the last five decades: a case study in northeast Argentina.

    Directory of Open Access Journals (Sweden)

    Alejandra Volpedo

    2017-01-01

    Full Text Available Environmental changes together with other stressors, such as habitat destruction, may cause widespread extinctions, decrease in biodiversity and disrupt natural communities, resulting in novel species assemblages. South America has a large diversity of freshwater fishes with complex evolutionary histories, mainly due to the presence of a wide variety of aquatic environments. Argentina has experienced an increase in rainfall in the last five decades leading to important climatic and hydrological changes. These changes caused the displacement of the isohyets towards the west. This study reports changes in the composition of freshwater fishes in northeast Argentina during the last five decades, and investigated a causal relationship between the variation in fish assemblages and climate change. The changes in the distribution and composition of fish communities between 1962 and 2010 were analyzed in 22 stations. These stations were agrouped in relation to the ichthyogeographic provinces: Great Rivers province (GRp and Pampean province (Pp. The correlation between rainfall in relation to the number total species from each of the studied provinces showed a significant positive correlation in Pp and not correlation in GRp. The annual mean river discharge and the number of total species from each ecoregion showed a significant positive correlation in GRp, and not correlation in Pp. The results of this study strongly suggest that the rainfall variations and river discharges observed in northeast Argentina induced changes in the composition of fish assemblages that lead to the redistribution of fish species among ichthyogeographic provinces.

  5. A Simple "in Vitro" Culture of Freshwater Prawn Embryos for Laboratory Investigations

    Science.gov (United States)

    Porntrai, Supaporn; Damrongphol, Praneet

    2008-01-01

    Giant freshwater prawn ("Macrobrachium rosenbergii" De Man) embryos can be cultured "in vitro" to hatching in 15% (v/v) artificial seawater (ASW). This technique can be applied as a bioassay for testing toxicity or for the effects of various substances on embryo development and can be used as a simple and low-cost model for…

  6. A Simple "in Vitro" Culture of Freshwater Prawn Embryos for Laboratory Investigations

    Science.gov (United States)

    Porntrai, Supaporn; Damrongphol, Praneet

    2008-01-01

    Giant freshwater prawn ("Macrobrachium rosenbergii" De Man) embryos can be cultured "in vitro" to hatching in 15% (v/v) artificial seawater (ASW). This technique can be applied as a bioassay for testing toxicity or for the effects of various substances on embryo development and can be used as a simple and low-cost model for studying embryo…

  7. A Simple "in Vitro" Culture of Freshwater Prawn Embryos for Laboratory Investigations

    Science.gov (United States)

    Porntrai, Supaporn; Damrongphol, Praneet

    2008-01-01

    Giant freshwater prawn ("Macrobrachium rosenbergii" De Man) embryos can be cultured "in vitro" to hatching in 15% (v/v) artificial seawater (ASW). This technique can be applied as a bioassay for testing toxicity or for the effects of various substances on embryo development and can be used as a simple and low-cost model for…

  8. Comparative analysis of technical efficiency for different production culture systems and species of freshwater aquaculture in Peninsular Malaysia

    Directory of Open Access Journals (Sweden)

    Abdullahi Iliyasu

    2016-05-01

    Full Text Available This study estimated the bias-corrected technical efficiency (BCTE of different culture systems and species of freshwater aquaculture in Malaysia using bootstrapping data envelopment analysis (DEA. Data were collected from 307 respondents from three states in Peninsular Malaysia using a well-structured questionnaire as well as oral interviews. The findings indicate that all technical efficiency scores for all culture systems and species are below the optimal level (i.e. one. In addition, the results show that farmers’ experience, contact with extension workers and household size have a positive and statistically significant impact on technical efficiency. This implies that farmers who have long tenure in fish farming and also the opportunity to meet with extension workers are operating close to the production frontier (technically efficient. On the other hand, the age of the farmers has a negative and statistically significant impact on technical efficiency. Although educational level and farm status have a positive impact on technical efficiency, they are statistically insignificant. Furthermore, all the inputs used in the production process of different culture systems and species contained slacks and need to be reduced accordingly. Feed, the major input in fish production and constituting over half of the production costs, is equally over-utilized. Thus, the government, in collaboration with research institutes and universities, should design a feeding formula for fish depending on species, culture systems and stages of growth. This could help to reduce production costs, increasing the farmers' income, as well as providing much needed animal protein to consumers at an affordable rate.

  9. Influence of temperature and nutrient content on lipid production in freshwater microalgae cultures

    OpenAIRE

    BOHNENBERGER,JULIANA E.; LUCIANE O. CROSSETTI

    2014-01-01

    The production of biomass by microalgae is considered a clean alternative compared to other plant crops that require large areas for cultivation and that generate environmental impacts. This study evaluated the influence of temperature and nutrients on lipid contents of cultured species of freshwater microalgae, with a view toward using these lipids for biodiesel production. Two strains of Monoraphidium contortum, a culture containing Chlorella vulgaris and Desmodesmus quadricauda and another...

  10. The potential for a fish ladder to mitigate against the loss of marine-estuarine-freshwater connectivity in a subtropical coastal lake

    CSIR Research Space (South Africa)

    Weerts, Steven P

    2014-01-01

    Full Text Available Increasing water demand in coastal regions has resulted in the construction of weirs and barrages in coastal freshwaters. These form barriers to migrations of estuarine and euryhaline marine fishes and crustaceans. This study assessed the impact...

  11. Environmental and organismal predictors of intraspecific variation in the stoichiometry of a neotropical freshwater fish.

    Science.gov (United States)

    El-Sabaawi, Rana W; Kohler, Tyler J; Zandoná, Eugenia; Travis, Joseph; Marshall, Michael C; Thomas, Steven A; Reznick, David N; Walsh, Matthew; Gilliam, James F; Pringle, Catherine; Flecker, Alexander S

    2012-01-01

    The elemental composition of animals, or their organismal stoichiometry, is thought to constrain their contribution to nutrient recycling, their interactions with other animals, and their demographic rates. Factors that affect organismal stoichiometry are generally poorly understood, but likely reflect elemental investments in morphological features and life history traits, acting in concert with the environmental availability of elements. We assessed the relative contribution of organismal traits and environmental variability to the stoichiometry of an insectivorous Neotropical stream fish, Rivulus hartii. We characterized the influence of body size, life history phenotype, stage of maturity, and environmental variability on organismal stoichiometry in 6 streams that differ in a broad suite of environmental variables. The elemental composition of R. hartii was variable, and overlapped with the wide range of elemental composition documented across freshwater fish taxa. Average %P composition was ∼3.2%(±0.6), average %N∼10.7%(±0.9), and average %C∼41.7%(±3.1). Streams were the strongest predictor of organismal stoichiometry, and explained up to 18% of the overall variance. This effect appeared to be largely explained by variability in quality of basal resources such as epilithon N:P and benthic organic matter C:N, along with variability in invertebrate standing stocks, an important food source for R. hartii. Organismal traits were weak predictors of organismal stoichiometry in this species, explaining when combined up to 7% of the overall variance in stoichiometry. Body size was significantly and positively correlated with %P, and negatively with N:P, and C:P, and life history phenotype was significantly correlated with %C, %P, C:P and C:N. Our study suggests that spatial variability in elemental availability is more strongly correlated with organismal stoichiometry than organismal traits, and suggests that the stoichiometry of carnivores may not be

  12. FRESHWATER FISH AND DECAPOD CRUSTACEAN POPULATIONS ON RÉUNION ISLAND, WITH AN ASSESSMENT OF SPECIES INTRODUCTIONS.

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    KEITH P.

    2002-01-01

    Full Text Available Streams of Réunion Island shelter with 26 fish species and 11 decapod crustacean species. Some species have been introduced (18%, some other are endemic to the island or to the Madagascar-Mascarenes region (16.2%, are originated from Indo-Pacific area (35.2% or from Indo-African area (27%. Gobiidae and Palaemonidae are the prevailing family in freshwaters, with the highest number of species. 16 species were introduced, mainly fishes, beginning at the turn of the 19th century, but only 4 of those have become acclimatised, while 7 have disappeared and the status of the other is uncertain.

  13. Spinitectus mexicanus n. sp. (Nematoda : Cystidicolidae) from the intestine of the freshwater fish Heterandria bimaculata in Mexico.

    Science.gov (United States)

    Caspeta-Mandujano, J M; Moravec, F; Salgado-Maldonado, G

    2000-02-01

    A new nematode, Spinitectus mexicanus n. sp., is described on the basis of the specimens recovered from the intestine of Heterandria bimaculata (Heckel) (Poeciliidae, Cyprinodontiformes) from 3 rivers of the Papaloapan River basin (type locality La Basura River), Los Tuxtlas, Veracruz State, Mexico. It differs from its congeners mainly in having the spination of the cuticle separated into 4 longitudinal sectors, each with posteriorly diminishing numbers of larger spines at the anterior part of body. It is the first species of Spinitectus described from a poeciliid fish and the second reported from freshwater fishes in Mexico.

  14. Spatial and temporal characterization of fish assemblages in a tropical coastal system influenced by freshwater inputs: northwestern Yucatan Peninsula.

    Science.gov (United States)

    Arceo-Carranza, Daniel; Vega-Cendejas, Ma Eugenia

    2009-01-01

    Coastal lagoons are important systems for freshwater, estuarine and marine organisms; they are considered important zones of reproduction, nursery and feeding for many fish species. The present study investigates the fish assemblages of the natural reserve of Dzilam and their relationship with the hydrologic variables. A total of 6 474 individuals (81 species) were collected, contributing with more than 50% considering the Importance Value Index (IVI), Sphoeroides testudineus, Fundulus persimilis, Anchoa mitchilli, Eucinostomus gula, Eucinostomus argenteus and Mugil trichodon. Differences in species composition were found between seasons the highest during the cold fronts. Spatially, differences were related with the presence of freshwater seeps, the highest in the ecological characterized eastern part and the lowest with higher difference in specific composition located in the western part of the internal zone, due to a higher abundance and dominance of L. rhomboides. Salinity and temperature were the variables that presented a higher influence in the distribution of some pelagic species such as A. mitchilli and A. hepsetus. Because of the abundant freshwater seeps characteristic of the coastal lagoons of Yucatan Peninsula their community structure and fish assemblage display spatial and temporal differences in specific composition.

  15. A moving target--incorporating knowledge of the spatial ecology of fish into the assessment and management of freshwater fish populations.

    Science.gov (United States)

    Cooke, Steven J; Martins, Eduardo G; Struthers, Daniel P; Gutowsky, Lee F G; Power, Michael; Doka, Susan E; Dettmers, John M; Crook, David A; Lucas, Martyn C; Holbrook, Christopher M; Krueger, Charles C

    2016-04-01

    Freshwater fish move vertically and horizontally through the aquatic landscape for a variety of reasons, such as to find and exploit patchy resources or to locate essential habitats (e.g., for spawning). Inherent challenges exist with the assessment of fish populations because they are moving targets. We submit that quantifying and describing the spatial ecology of fish and their habitat is an important component of freshwater fishery assessment and management. With a growing number of tools available for studying the spatial ecology of fishes (e.g., telemetry, population genetics, hydroacoustics, otolith microchemistry, stable isotope analysis), new knowledge can now be generated and incorporated into biological assessment and fishery management. For example, knowing when, where, and how to deploy assessment gears is essential to inform, refine, or calibrate assessment protocols. Such information is also useful for quantifying or avoiding bycatch of imperiled species. Knowledge of habitat connectivity and usage can identify critically important migration corridors and habitats and can be used to improve our understanding of variables that influence spatial structuring of fish populations. Similarly, demographic processes are partly driven by the behavior of fish and mediated by environmental drivers. Information on these processes is critical to the development and application of realistic population dynamics models. Collectively, biological assessment, when informed by knowledge of spatial ecology, can provide managers with the ability to understand how and when fish and their habitats may be exposed to different threats. Naturally, this knowledge helps to better evaluate or develop strategies to protect the long-term viability of fishery production. Failure to understand the spatial ecology of fishes and to incorporate spatiotemporal data can bias population assessments and forecasts and potentially lead to ineffective or counterproductive management actions.

  16. A moving target—incorporating knowledge of the spatial ecology of fish into the assessment and management of freshwater fish populations

    Science.gov (United States)

    Cooke, Steven J.; Martins, Eduardo G; Struthers, Daniel P; Gutowsky, Lee F G; Powers, Michael H.; Doka, Susan E; Dettmers, John M.; Crook, David A; Lucas, Martyn C.; Holbrook, Christopher; Krueger, Charles C.

    2016-01-01

    Freshwater fish move vertically and horizontally through the aquatic landscape for a variety of reasons, such as to find and exploit patchy resources or to locate essential habitats (e.g., for spawning). Inherent challenges exist with the assessment of fish populations because they are moving targets. We submit that quantifying and describing the spatial ecology of fish and their habitat is an important component of freshwater fishery assessment and management. With a growing number of tools available for studying the spatial ecology of fishes (e.g., telemetry, population genetics, hydroacoustics, otolith microchemistry, stable isotope analysis), new knowledge can now be generated and incorporated into biological assessment and fishery management. For example, knowing when, where, and how to deploy assessment gears is essential to inform, refine, or calibrate assessment protocols. Such information is also useful for quantifying or avoiding bycatch of imperiled species. Knowledge of habitat connectivity and usage can identify critically important migration corridors and habitats and can be used to improve our understanding of variables that influence spatial structuring of fish populations. Similarly, demographic processes are partly driven by the behavior of fish and mediated by environmental drivers. Information on these processes is critical to the development and application of realistic population dynamics models. Collectively, biological assessment, when informed by knowledge of spatial ecology, can provide managers with the ability to understand how and when fish and their habitats may be exposed to different threats. Naturally, this knowledge helps to better evaluate or develop strategies to protect the long-term viability of fishery production. Failure to understand the spatial ecology of fishes and to incorporate spatiotemporal data can bias population assessments and forecasts and potentially lead to ineffective or counterproductive management actions.

  17. Descriptions of diplostomid metacercariae (Digenea: Diplostomidae from freshwater fishes in the Tshwane area

    Directory of Open Access Journals (Sweden)

    Esmey B.E. Moema

    2013-03-01

    Full Text Available The metacercarial (larval stages of diplostomid digeneans are known to inhabit freshwater fish, causing tissue damage in the process. Due to their widespread diversity, little is known about their life cycle. The classification of these parasitic stages to the species level using only the morphology is very challenging due to the lack of genitalia; they are regarded to be the most important structures in the identification of these organisms. In this study, additional morphological information through light and scanning electron microscopy is given for two different diplostomids found in the cranial cavity of Clarias gariepinus and the vitreous chambers of Tilapia sparrmanii and Pseudocrenilabrus philander. The diplostomid metacercaria inhabiting the cranial cavity of Clarias gariepinus was morphologically identified as Diplostomulum (Tylodelphys mashonenseand an unknown metacercaria of the genus Diplostomumwas found in the vitreous chambers of Pseudocrenilabrus philander and Tilapia sparrmanii. Both parasitic species’ 28S recombinant deoxyribonucleic acid genomic regions were successfully amplified using Dig 125/1500R primer pairs. The assay yielded a product of approximately 1300 base pairs as seen on the gel images. There were 14 nucleotide differences over the entire analysed sequences resulting in a 1.1% (14/1273 nucleotide difference. In line with the morphological characteristics of these parasites, there seemed to be a slight difference in their genetic makeup. The application of molecular techniques on digenetic trematodes seems very promising and may yield great potential in future descriptions of morphologically similar parasitic species.

  18. Activity of esterases from different tissues of freshwater fish and responses of their isoenzymes to inhibitors.

    Science.gov (United States)

    Li, S N; Fan, D F

    1997-06-06

    Activity of nonspecific esterase from different tissues (i.e., liver, gallbladder, heart, intestine, and muscle) of five species of freshwater fish, namely, topmouth gudgeon (Pseudorasbora parva), goldfish (Carassius auratus), nile tilapia (Tilapia nilotica), mosquitofish (Gambusia affinis), and rainbow trout (Salmo gairdneri) was tested using alpha-naphthyl acetate as substrate. The results indicated that activity of the enzyme was mainly concentrated in the digestive system (i.e., intestine, liver, bile). The overall activity was highest in nile tilapia, followed by mosquitofish, topmouth gudgeon, goldfish, and lowest in rainbow trout. Electrophoresis and the following in vitro treatment of the isoenzymes with triphenol phosphate (TPP, an inhibitor of carboxylesterase) indicated the TPP-sensitive esterase was mainly distributed in liver of the five species. The enzyme was not found in the other five tissues (including gill) except in gallbladder of topmouth gudgeon and goldfish. The correlation was obviously improved between susceptibility and detoxification capacity if activity of the TPP-sensitive esterase was employed instead of that of the nonspecific esterase to make the comparison. In vitro treatment of nonspecific esterase in liver with malaoxon proved that the active metabolite of malathion inhibited a different isoenzyme from the TPP-sensitive one.

  19. Osmoregulatory adaptations of freshwater air-breathing snakehead fish (Channa striata) after exposure to brackish water.

    Science.gov (United States)

    Nakkrasae, La-iad; Wisetdee, Khanitha; Charoenphandhu, Narattaphol

    2015-07-01

    NaCl-rich rock salt dissolved in natural water source leads to salinity fluctuation that profoundly affects freshwater ecosystem and aquatic fauna. The snakehead (Channa striata) can live in saline water, but the osmoregulatory mechanisms underlying this ability remain unclear. Herein, we found that exposure to salinities ≥ 10‰ NaCl markedly elevated plasma cortisol and glucose levels, and caused muscle dehydration. In a study of time-dependent response after being transferred from fresh water (0‰ NaCl, FW) to salt-dissolved brackish water (10‰ NaCl, SW), FW-SW, cortisol increased rapidly along with elevations of plasma glucose and lactate. Interestingly, plasma cortisol returned to baseline after prolonged exposure, followed by a second peak that probably enhanced the branchial Na(+)/K(+)-ATPase activity. Under SW-FW condition, Na(+)/K(+)-ATPase activity was not altered as compared to SW-adapted fish. In conclusion, salinity change, especially FW-SW, induced a stress response and hence cortisol release in C. striata, which might increase plasma glucose and lactate to energize the branchial Na(+)/K(+)-ATPase.

  20. In vitro probiotic profiling of novel Enterococcus faecium and Leuconostoc mesenteroides from Tunisian freshwater fishes.

    Science.gov (United States)

    El-Jeni, Rim; El Bour, Monia; Calo-Mata, Pilar; Böhme, Karola; Fernández-No, Inmaculada C; Barros-Velázquez, Jorge; Bouhaouala-Zahar, Balkiss

    2016-01-01

    Novel lactic acid bacteria isolated from different organs of freshwater fish were examined for their potential application as probiotics in raw and processed foods. Four isolates of Enterococcus faecium and Leuconostoc mesenteroides were identified at the molecular level by 16S rRNA sequencing and random amplification of polymorphic DNA - polymerase chain reaction, and their antimicrobial activity against a panel of pathogens and food-poisoning bacteria was investigated. The whole bacteriocins of the 4 isolates were characterized by enterobacterial repetitive intergenic consensus sequences in PCR. The isolates exhibited high inhibitory activities against food-borne pathogens and spoilage microbial species and have significant probiotic profiles, since they survived at pH 3.0 and in the presence of bile salts, pancreatin, and pepsin, without any detectable hemolytic activity. Further, moderate heat resistance, adhesion ability to steel surfaces, and sensitivity to clinically relevant antimicrobial agents were revealed for all the isolates. These results highlight the specific probiotic properties of the strains and give evidence for potential application in minimally processed foods subjected to moderate heat processing.

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

    Directory of Open Access Journals (Sweden)

    Miguel Clavero

    2015-12-01

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

  2. Comparing the Performance of Protected and Unprotected Areas in Conserving Freshwater Fish Abundance and Biodiversity in Lake Tanganyika, Tanzania

    Directory of Open Access Journals (Sweden)

    Emmanuel Andrew Sweke

    2016-01-01

    Full Text Available Marine protected areas have been shown to conserve aquatic resources including fish, but few studies have been conducted of protected areas in freshwater environments. This is particularly true of Lake Tanganyika, Tanzania. To better conserve the lake’s biodiversity, an understanding of the role played by protected areas in conserving fish abundance and diversity is needed. Sampling of fish and environmental parameters was performed within the Mahale Mountains National Park (MMNP and nearby unprotected areas at depths between 5 m and 10 m. Twelve replicates of fish sampling were performed at each site using gillnets set perpendicularly to the shore. Mann-Whitney tests were performed, and the total amount of species turnover was calculated. A total of 518 individual fish from 57 species were recorded in the survey. The fish weight abundance was fivefold greater in the MMNP than in the unprotected areas. Fish abundance and diversity were higher in the MMNP than in the unprotected areas and decreased with distance from it. Our findings confirmed the importance of the protected area in conserving fish resources in Lake Tanganyika. The study provides baseline information for management of the resources and guiding future studies in the lake and other related ecosystems. Management approaches that foster awareness and engage with communities surrounding the MMNP are recommended for successful conservation of the resources in the region.

  3. A new approach to predicting environmental transfer of radionuclides to wildlife: A demonstration for freshwater fish and caesium

    Energy Technology Data Exchange (ETDEWEB)

    Beresford, N.A., E-mail: nab@ceh.ac.uk [NERC Centre for Ecology and Hydrology, Lancaster Environment Centre, Library Av. Bailrigg, Lancaster LA1 4AP (United Kingdom); Yankovich, T.L. [Saskatchewan Research Council, Environment and Forestry, 125, 15 Innovation Blvd., Saskatoon, SK S7N 2X8 (Canada); Wood, M.D. [School of Environment and Life Sciences, Room 323, Peel Building, University of Salford, Manchester, M5 4WT (United Kingdom); Fesenko, S. [International Atomic Energy Agency, 1400 Vienna (Austria); Andersson, P. [Strålsäkerhetsnymdigheten, Swedish Radiation Safety Authority, SE-171 16 Stockholm (Sweden); Muikku, M. [STUK, P.O. Box 14, 00881 Helsinki (Finland); Willey, N.J. [Centre for Research in Biosciences, University of the West of England, Coldharbour Lane, Frenchay, Bristol BS16 1QY (United Kingdom)

    2013-10-01

    The application of the concentration ratio (CR) to predict radionuclide activity concentrations in wildlife from those in soil or water has become the widely accepted approach for environmental assessments. Recently both the ICRP and IAEA have produced compilations of CR values for application in environmental assessment. However, the CR approach has many limitations, most notably, that the transfer of most radionuclides is largely determined by site-specific factors (e.g. water or soil chemistry). Furthermore, there are few, if any, CR values for many radionuclide-organism combinations. In this paper, we propose an alternative approach and, as an example, demonstrate and test this for caesium and freshwater fish. Using a Residual Maximum Likelihood (REML) mixed-model regression we analysed a dataset comprising 597 entries for 53 freshwater fish species from 67 sites. The REML analysis generated a mean value for each species on a common scale after REML adjustment taking account of the effect of the inter-site variation. Using an independent dataset, we subsequently test the hypothesis that the REML model outputs can be used to predict radionuclide, in this case radiocaesium, activity concentrations in unknown species from the results of a species which has been sampled at a specific site. The outputs of the REML analysis accurately predicted {sup 137}Cs activity concentrations in different species of fish from 27 Finnish lakes; these data had not been used in our initial analyses. We recommend that this alternative approach be further investigated for other radionuclides and ecosystems. - Highlights: • An alternative approach to estimating radionuclide transfer to wildlife is presented. • Analysed a dataset comprising 53 freshwater fish species collected from 67 sites. • Residual Maximum Likelihood mixed model regression is used. • Model output takes account of the effect of inter-site variation. • Successfully predicted {sup 137}Cs concentrations in

  4. Biodiversity of freshwater fish of a protected river in India: comparison with unprotected habitat

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    Uttam Kumar Sarkar

    2013-03-01

    Full Text Available In India, freshwater environments are experiencing serious threats to biodiversity, and there is an urgent priority for the search of alternative techniques to promote fish biodiversity conservation and management. With this aim, the present study was undertaken to assess the fish biodiversity within and outside a river protected area, and to evaluate whether the protected river area provides some benefits to riverine fish biodiversity. To assess this, the pattern of freshwater fish diversity was studied in river Gerua, along with some physicochemical conditions, from April 2000 to March 2004. For this, a comparison was made between a 15km stretch of a protected area (Katerniaghat Wildlife Sanctuary, and an unprotected one 85km downstream. In each site some physicochemical conditions were obtained, and fish were caught by normal gears and the diversity per site described. Our results showed that water temperature resulted warmest during the pre-monsoon season (25ºC and low during the winter (14-15ºC; turbidity considerably varied by season. In the protected area, a total of 87 species belonging to eight orders, 22 families and 52 genera were collected; while a maximum of 59 species belonging to six orders, 20 families and 42 genera were recorded from the unprotected areas. Cyprinids were found to be the most dominant genera and Salmostoma bacaila was the most numerous species in the sanctuary area. Other numerous species were Eutropiichthys vacha, Notopterus notopterus, Clupisoma garua and Bagarius bagarius. The results indicated more species, greater abundances, larger individuals, and higher number of endangered fishes within the sanctuary area when compared to the unprotected area. Analysis on the mean abundance of endangered and vulnerable species for the evaluated areas in the sanctuary versus unprotected ones indicated significant differences in fish abundance (pEn India los ambientes de agua dulce están experimentando una grave amenaza

  5. SE Asian freshwater fish population and networks: the impacts of climatic and environmental change on a vital resource

    Science.gov (United States)

    Santos, Rita; Parsons, Daniel; Cowx, Ian

    2016-04-01

    The Mekong River is the 10th largest freshwater river in the world, with the second highest biodiversity wealth, behind the much larger Amazon basin. The fisheries activity in the Lower Mekong countries counts for 2.7 million tons of fish per year, with an estimated value worth up to US 7 billion. For the 60 million people living in the basin, fish represent their primary source of economic income and protein intake, with an average per capita consumption estimated at 45.4 Kg. The proposed hydropower development in the basin is threatening its sustainability and resilience. Such developments affect fish migration patterns, hydrograph flood duration and magnitudes and sediment flux. Climate change is also likely to impact the basin, exacerbating the issues created by development. As a monsoonal system, the Mekong River's pronounced annual flood pulse cycle is important in creating variable habitat for fish productivity. Moreover, the annual flood also triggers fish migration and provides vital nutrients carried by the sediment flux. This paper examines the interactions between both dam development and climate change scenarios on fish habitat and habitat connectivity, with the aim of predicting how these will affect fish species composition and fisheries catch. The project will also employ Environmental DNA (eDNA) to quantify and understand the species composition of this complex and large freshwater system. By applying molecular analysis, it is possible to trace species abundance and migration patterns of fish and evaluate the ecological networks establish between an inland system. The aim of this work is to estimate, using process-informed models, the impacts of the proposed dam development and climate change scenarios on the hydrological and hydraulic conditions of habitat availability for fish. Furthermore, it will evaluate the connectivity along the Mekong and its tributaries, and the importance of maintaining these migration pathways, used by a great diversity

  6. Spatial gradients in freshwater fish diversity, abundance and current pattern in the Himalayan region of Upper Ganges Basin, India

    Directory of Open Access Journals (Sweden)

    AJEY KUMAR PATHAK

    2014-10-01

    Full Text Available Pathak AK, Sarkar UK, Singh SP. 2014. Spatial gradients in freshwater fish diversity, abundance and current pattern in the Himalayan region of Upper Ganges Basin, India. Biodiversitas 15: 186-194.The present study describes the analysis and mapping of the different measurements of freshwater fish biodiversity of the Upper Ganges basin in the Himalayan region using spatial interpolation methods of Geographical Information System. The diversity, richness and abundance of fishes for each sampling location were determined and Kriging interpolation was applied on each fisheries measurement to predict and produce semivariogram. The semivariogarms produced were cross validated and reclassified. The reclassified maps for richness, abundance and diversity of fishes, occurrence of cold water threatened fish and abundance of important genera like Tor, Schziothorax and species were produced. The result of the Kriging produced good results and overall error in the estimation process was found significant. The cross validation of semovariograms also provided a better result with the observed data sets. Moreover, weighted overlay analysis of the reclassified raster maps of richness and abundance of fishes produced the classified raster map at different evaluation scale (0-10 qualitatively describing the gradient of species richness and abundance compositely. Similarly, the classified raster map at same evaluation scale qualitatively describing the gradient of species abundance and diversity compositely was produced and published. Further, basin wise analysis between Alaknanda/Pindar and Ganga1 sub basins showed 0.745 disparities at 0.745 distances in 2 dimensional spaces. The richness, diversity and abundance of threatened fishes among the different sampling locations were not significant (p = 0.9.

  7. Laboratory culture of the freshwater benthic gastropod Bellamya aeruginosa (Reeve) and its utility as a test species for sediment toxicity.

    Science.gov (United States)

    Ma, Taowu; Gong, Shuangjiao; Zhou, Ke; Zhu, Cheng; Deng, Kaidong; Luo, Qinghua; Wang, Zijian

    2010-01-01

    This study aimed to develop original laboratory culture and sediment toxicity testing protocols for the freshwater gastropod Bellamya aeruginosa (Reeve), a new potential species for sediment toxicity testing. B. aeruginosa was successfully cultured with an effective culture system under proposed laboratory conditions. Optimal ad libitum feeding levels for larvae, juveniles, and adults were 2.0, 6.0, and 16.0 mg fish food/(snail x day), respectively. Mean survival rates of juveniles were higher than 90%. The snails could be sexed at 9 weeks of age, and their generation time is approximately 4 months. Reproduction continued all year around; the mean fecundity was 0.55 newborn/(female x day). The utility of this species for bioassays was evaluated in both 10-day and 28-day case studies with artificial sediments. The 10-day LC50 of Cu for larvae was 480 gg/g dry weight (dw), and the lowest observed effects concentration of Cu for survival and growth of larvae was 195 microg/g dw. Survival and growth are reliable indicators of acute toxicity. Larvae accumulated more Cu than adults. B. aeruginosa exhibited a higher sensitivity to Cu exposure than standard test species (Hyalella azteca and Chironomus tentans). The 28-day test of sediment toxicity with adults showed that fecundity was a robust endpoint indicator of reproductive toxicity, and the biochemical endpoints of superoxide dismutase, catalase, and glutathione could be used as sensitive biomarkers for Cu-induced oxidative damage. B. aeruginosa can be therefore recommended as a candidate for the standardization of the freshwater sediment toxicity test protocol.

  8. Fish fins as non-lethal surrogates for muscle tissues in freshwater food web studies using stable isotopes.

    Science.gov (United States)

    Hette Tronquart, Nicolas; Mazeas, Laurent; Reuilly-Manenti, Liana; Zahm, Amandine; Belliard, Jérôme

    2012-07-30

    Dorsal white muscle is the standard tissue analysed in fish trophic studies using stable isotope analyses. However, sampling white muscle often implies the sacrifice of fish. Thus, we examined whether the non-lethal sampling of fin tissue can substitute muscle sampling in food web studies. Analysing muscle and fin δ(15)N and δ(13)C values of 466 European freshwater fish (14 species) with an elemental analyser coupled with an isotope ratio mass spectrometer, we compared the isotope values of the two tissues. Correlations between fin and muscle isotope ratios were examined for all fish together and specifically for 12 species. We further proposed four methods of assessing muscle from fin isotope ratios and estimated the errors made using these muscle surrogates. Despite significant differences between isotope values of the two tissues, fin and muscle isotopic signals are strongly correlated. Muscle values, estimated with raw fin isotope ratios (1st method), induce an error of ca. 1‰ for both isotopes. In comparison, specific (2nd method) or general (3rd method) correlations provide meaningful corrections of fin isotope ratios (errors muscle estimates (errors >0.8‰). There is little chance that a global model can be created. However, the 2nd and 3rd methods of estimating muscle values from fin isotope ratios should provide an acceptable level of error for the studies of European freshwater food web. We thus recommend that future studies use fin tissue as a non-lethal surrogate for muscle. Copyright © 2012 John Wiley & Sons, Ltd.

  9. Effect of an acute and chronic toxicity of four commercial detergents on the freshwater fish Gambusia affinis Baird & Gerard.

    Science.gov (United States)

    Saxena, Pratibha; Sharma, Subhasini; Sharma, Shweta; Suryavathi, V; Grover, Ruby; Soni, Pratima; Kumar, Suresh; Sharma, K P

    2005-04-01

    The toxic effects of four commercial detergents (two washing powders and two cakes) are reported in this paper on behavior, mortality and RBC counts of a freshwater fish Gambusia affinis. During acute toxicity studies (96h), surface movements of fish increased markedly for 24h, only at higher concentrations (>10 ppm) of all the four detergents. Thereafter, they were lethargic and bottom dwellers similar to those exposed for a period of 30 days in the longterm ecotoxicological studies made on detergent powders at a sublethal concentration (10 ppm). The detergents exposed to fish were found slippery due to mucous secretion. Hemorrhage regions were also found on their gills. The dissolved oxygen content also decreased (10-18%) in the detergent treatments of higher concentration (> 10 ppm). During acute toxicity studies, cakes (LC50 = 6.69 - 19.98ppm) were found more toxic than powders (LC50 = 18.34-20.72ppm). In comparison to the control fish, RBC counts decreased (12-64%) in the detergent exposed fish, being more pronounced among those exposed to cakes. The chronic exposure (30 days) of the fish also resulted in reduction in the RBC counts (41-58%). It is thus evident that all the four detergents are toxic to the fish Gambusia affinis.

  10. Geothermal aquaculture: a guide to freshwater prawn culture

    Energy Technology Data Exchange (ETDEWEB)

    Hayes, A.; Johnson, W.C.

    1980-05-01

    Biological data of the Malaysian prawn, Macrobrachium rosenbergii, are summarized. A history on its rearing techniques is given, but through the use of geothermal water or industrial warm water effluent, its range can be expanded. The use of wasted geothermal water at the Oregon Institute of Technology for prawn ponds is noted. Pond management and design; the hatchery design and function for larval culture; and geothermal applications (legal aspects and constraints) are discussed. (MCW)

  11. Determination of moderately polar arsenolipids and mercury speciation in freshwater fish of the River Elbe (Saxony, Germany).

    Science.gov (United States)

    Arroyo-Abad, Uriel; Pfeifer, Matthias; Mothes, Sibylle; Stärk, Hans-Joachim; Piechotta, Christian; Mattusch, Jürgen; Reemtsma, Thorsten

    2016-01-01

    Arsenic and mercury are frequent contaminants in the environment and care must be taken to limit their entrance into the food chain. The toxicity of both elements strongly depends upon their speciation. Total amounts of As and Hg as well as their species were analyzed in muscle and liver of 26 fishes of seven freshwater fish species caught in the River Elbe. The median concentrations of As were 162 μg kg(-1) w.w. in liver and 92 μg kg(-1) w.w. in muscle. The median concentrations of total Hg were 241 μg kg(-1) w.w. in liver and 256 μg kg(-1) w.w. in muscle. While this level of Hg contamination of the freshwater fish in the River Elbe is significantly lower than 20 years ago, it exceeds the recommended environmental quality standard of 20 μg Hg kg(-1) w.w. by a factor of 5-50. However, the European maximum level of 500 μg Hg kg(-1) for fish for human consumption is rarely exceeded. Arsenic-containing fatty acids and hydrocarbons were determined and partially identified in methanolic extracts of the fish by HPLC coupled in parallel to ICP-MS (element specific detection) and ESI-Q-TOF-MS (molecular structure detection). While arsenobetaine was the dominant As species in the fish, six arsenolipids were detected and identified in the extracts of liver tissue in common bream (Abramis brama), ide (Leuciscus idus), asp (Aspius aspius) and northern pike (Esox lucius). Four arsenic-containing fatty acids (AsFA) and two arsenic-containing hydrocarbons (AsHC) are reported in freshwater fish for the first time. With respect to mercury the more toxic MeHg(+) was the major species in muscle tissue (>90% of total Hg) while in liver Hg(2+) and MeHg(+) were of equal importance. The results show the high relevance of element speciation in addition to the determination of total element concentrations to correctly assess the burden of these two elements in fish.

  12. Small fishes crossed a large mountain range: Quaternary stream capture events and freshwater fishes on both sides of the Taebaek Mountains.

    Science.gov (United States)

    Kim, Daemin; Hirt, M Vincent; Simons, Andrew M; Won, Yong-Jin

    2016-08-31

    The Taebaek Mountains in South Korea serves as the most apparent biogeographic barrier for South Korean freshwater fishes, resulting in two distinct ichthyofaunal assemblages on the eastern (East/Japan Sea slope) and western (Yellow Sea and Korea Strait slopes) sides of the mountain range. Of nearly 100 species of native primary freshwater fishes in South Korea, only 18 species occur naturally on both sides of the mountain range. Interestingly, there are five rheophilic species (Phoxinus phoxinus, Coreoleuciscus splendidus, Ladislavia taczanowskii, Iksookimia koreensis and Koreocobitis rotundicaudata) found on both sides of the Taebaek Mountains that are geographically restricted to the Osip River (and several neighboring rivers, for L. taczanowskii and I. koreensis) on the eastern side of the mountain range. The Osip River and its neighboring rivers also shared a rheophilic freshwater fish, Liobagrus mediadiposalis, with the Nakdong River on the western side of the mountain range. We assessed historical biogeographic hypotheses on the presence of these rheophilic fishes, utilizing DNA sequence data from the mitochondrial cytochrome b gene. Results of our divergence time estimation indicate that ichthyofaunal transfers into the Osip River (and several neighboring rivers in East Sea slope) have occurred from the Han (Yellow Sea slope) and Nakdong (Korea Strait slope) rivers since the late-Pleistocene. The inferred divergence times for the ichthyofaunal transfer across the Taebaek Mountains were consistent with the timing of hypothesized multiple reactivations of the Osip River Fault (late-Pleistocene), suggesting that the Osip River Fault reactivations may have caused stream capture events, followed by ichthyofaunal transfer, not only between the Osip and Nakdong rivers, but also between the Osip and Han rivers. This article is protected by copyright. All rights reserved.

  13. Scales of freshwater fish Labeo rohita as bioindicators of water pollution in Tung Dhab Drain, Amritsar, Punjab, India.

    Science.gov (United States)

    Kaur, Rajbir; Dua, Anish

    2015-01-01

    This study examined the impact of municipal wastewater on scale morphology of freshwater fish Labeo rohita. Fish were exposed to sublethal concentrations (17.7, 26.6, or 35.4%) of municipal wastewater for durations of 15, 30, and 60 d. Recovery experiments were also performed for a duration of 60 d. Scales were extracted after respective exposure periods, cleaned, and processed for scanning electron microscopy. Results showed concentration- and exposure duration-dependent alterations in the morphology of scales. Severe damage was observed at the anterior and posterior portions of scales in the form of lepidontal breakage and uprooting, destructions at the base of circuli and radii along with complete structural loss in the focal region and adjacent circuli and radii, and alterations in structure of tubercles. Data indicate that scales of fish L. rohita may be employed as bioindicators of water pollution and could be incorporated into water monitoring surveillance.

  14. Mercury and selenium concentrations in muscle tissue of different species of predatory freshwater fish and correlation between these elements.

    Science.gov (United States)

    Strapáč, Imrich; Sokol, Jozef; Žatko, Daniel; Baranová, Mária

    2012-01-01

    Concentrations of total mercury and selenium were determined in 49 and 42 muscle tissue samples, respectively, of six species of predatory freshwater fish, dace (Leuciscus leuciscus), pike perch (Sander lucioperca), pike (Esox lucius), European catfish (Silurus glanis), rainbow trout (Oncorhynchus mykiss) and asp (Aspius aspius). Muscle selenium concentration did not correlate with the corresponding total mercury concentration (R² < 0.198) in all examined predatory fish species. There was an inverse correlation between the ratio Se/Hg content and the total mercury content in the muscle tissues of dace, pike perch, pike, European catfish and asp. The muscle tissue of rainbow trout exhibits a linear correlation between the ratio Se/Hg content and the total mercury content. The total mercury concentration of all examined samples did not exceed the hygienic limit for Hg for predatory fish.

  15. Structuring of zooplankton and fish larvae assemblages in a freshwater-influenced Greenlandic fjord- influence from hydrography and prey availability

    DEFF Research Database (Denmark)

    Swalethorp, Rasmus; Malanski, Evandro; Munk, Peter

    2015-01-01

    fish species to changing hydrographical and feeding environments in a sub-Arctic area in Greenland. The study was carried out along a transect covering a wide range of physical conditions from the deep ocean to the icecap in the Godtha°bsfjord on the south-western Greenland coast. Along the transect......The recent increase in temperature and freshwater runoff in the Arctic will influence the functioning of the plankton ecosystem and hence the life of the fish larvae residing in these areas. Here, we studied the strength of physical– biological linkages and the adaptability of individual larval......, we identified a series of distinct zooplankton and larval fish assemblages which showed linkage to water mass characteristics, to the presence of frontal structures and to availability of preferred prey. Spawning site location and water circulation was also likely to influence distributional patterns...

  16. CEPF Western Ghats Special Series: Freshwater fish fauna of Krishna River at Wai, northern Western Ghats, India

    Directory of Open Access Journals (Sweden)

    S.S. Kharat

    2012-06-01

    Full Text Available Freshwater fish fauna of the Krishna River at Wai, and the Dhom reservoir upstream of Wai, was studied. Fifty one species belonging to 14 families and 33 genera were recorded; 13 endemic to the Western Ghats and two to the Krishna River system. Moderate to rare populations were found for six globally threatened species: Gonoproktopterus curmuca, Labeo potail, Schismatorhynchos nukta, Tor khudree, T. mussullah and Parapsilorhynchus discophorus. Fish in this area are under threat due to two introduced species and five transplanted species, and due to other anthropogenic activities such as overfishing and organic and inorganic pollution of the river. Site based conservation action plans are needed for conservation of rare and threatened fish in this area.

  17. Two new species of Myxobolus (Myxozoa: Myxosporea: Bivalvulida) infecting Indian freshwater fishes in Punjab Wetlands (India).

    Science.gov (United States)

    Kaur, Harpreet; Singh, Ranjeet

    2011-05-01

    A survey of parasites of freshwater fishes in Harike and Ropar Wetlands of Punjab (India) revealed the presence of two new myxosporean species belonging to the genus Myxobolus Butschli 1882. Spores of the first species, M. duodenalis sp. nov. parasitize the inner wall of the duodenum of Wallago attu (Bloch and Schneider) (Cypriniformis: Cyprinidae) vern. mulli are characterized by a broad, pyriform shape with a blunt anterior end and measures 9.0 × 3.20 μm. Spore valves are thin, smooth, and symmetrical with no parietal folds. There are two polar capsules, prominently unequal and pyriform in shape, with a narrow anterior end and a rounded posterior end. The larger polar capsule measures 4.70 × 1.76 μm and the smaller 2.76 × 1.06 μm. The larger polar capsule occupies more than half, while the smaller one occupies one third of the spore body cavity. An intercapsular process is absent. Spores of the second species, Myxobolus patialensis sp. nov. parasitize the caudal fin of Labeo rohita (Ham. 1822) (Cypriniformis: Cyprinidae) vern. rohu are pyriform in valvular view, measuring 11.28 × 6.67 μm. The two shell valves are asymmetrical and contain five parietal folds along the posterior end of the spore. Two anteriorly situated polar capsules, elongated and oval in shape are prominently unequal in size. The larger polar capsule measures 4.8 × 3.1 μm and smaller one 1.70 × 1.51 μm. The larger polar capsule lies obliquely to the spore axis and the smaller one is at the same level but pointing outward anteriolaterally. An intercapsular process is absent. This species is characterized by having a prominent ridge on the shell surface anteriolaterally on the side of the smaller polar capsule.

  18. Two new species of Rhabdochona (Nematoda: Rhabdochonidae) from freshwater fishes in Thailand.

    Science.gov (United States)

    Moravec, Frantisek; Yooyen, Thanapon

    2011-09-01

    Two new species ofrhabdochonid nematodes are described from the intestine of freshwater fishes in Chiang Mai Province, northern Thailand: Rhabdochona (Rhabdochona) pseudomysti sp. n. from the catfish Pseudomystus siamensis (Regan) (Bagridae, Siluriformes) in the Fang Brook, a tributary of the Kok River (the Mekong River basin), Fang District and Rhabdochona (Globochona) thaiensis sp. n. from the cyprinid Mystacoleucus marginatus (Valenciennes) (Cyprinidae, Cypriniformes) in the Ping River (the Chao Phraya River basin), Muang District. Rhabdochona pseudomysti is mainly characterized by simple, leaf-like oval deirids (a unique feature among Rhabdochona spp.), a prostom with 14 anterior teeth, the presence of basal prostomal teeth, the length ratio of the muscular and glandular portions of oesophagus (1:2.1-2.6), an unusually long left spicule (1.10-1.22 mm), length ratio of spicules (1:11.5-14.7), arrangement of genital papillae, and conspicuously elevated vulval lips. Rhabdochona thaiensis differs from other representatives of the subgenus Globochona Moravec, 1972 possessing caudal projections on the tail tip in that it has only 2 claw-shaped projections located ventrally on the tail tip of both males and females; the species is mainly characterized by the presence of distinct pseudolabia, 8 anterior prostomal teeth, absence of basal teeth, bifurcated deirids, length ratio of the muscular and glandular portions of oesophagus (1:11.3-11.9), conspicuously short (135-141 microm) left spicule, arrangement of genital papillae, and somewhat elevated vulval lips. Fully developed eggs of R. pseudomysti and R. thaiensis remain unknown. These are the first nominal species of Rhabdochona reported from Thailand.

  19. Spatial heterogeneity in the Mediterranean Biodiversity Hotspot affects barcoding accuracy of its freshwater fishes.

    Science.gov (United States)

    Geiger, M F; Herder, F; Monaghan, M T; Almada, V; Barbieri, R; Bariche, M; Berrebi, P; Bohlen, J; Casal-Lopez, M; Delmastro, G B; Denys, G P J; Dettai, A; Doadrio, I; Kalogianni, E; Kärst, H; Kottelat, M; Kovačić, M; Laporte, M; Lorenzoni, M; Marčić, Z; Özuluğ, M; Perdices, A; Perea, S; Persat, H; Porcelotti, S; Puzzi, C; Robalo, J; Šanda, R; Schneider, M; Šlechtová, V; Stoumboudi, M; Walter, S; Freyhof, J

    2014-11-01

    Incomplete knowledge of biodiversity remains a stumbling block for conservation planning and even occurs within globally important Biodiversity Hotspots (BH). Although technical advances have boosted the power of molecular biodiversity assessments, the link between DNA sequences and species and the analytics to discriminate entities remain crucial. Here, we present an analysis of the first DNA barcode library for the freshwater fish fauna of the Mediterranean BH (526 spp.), with virtually complete species coverage (498 spp., 98% extant species). In order to build an identification system supporting conservation, we compared species determination by taxonomists to multiple clustering analyses of DNA barcodes for 3165 specimens. The congruence of barcode clusters with morphological determination was strongly dependent on the method of cluster delineation, but was highest with the general mixed Yule-coalescent (GMYC) model-based approach (83% of all species recovered as GMYC entity). Overall, genetic morphological discontinuities suggest the existence of up to 64 previously unrecognized candidate species. We found reduced identification accuracy when using the entire DNA-barcode database, compared with analyses on databases for individual river catchments. This scale effect has important implications for barcoding assessments and suggests that fairly simple identification pipelines provide sufficient resolution in local applications. We calculated Evolutionarily Distinct and Globally Endangered scores in order to identify candidate species for conservation priority and argue that the evolutionary content of barcode data can be used to detect priority species for future IUCN assessments. We show that large-scale barcoding inventories of complex biotas are feasible and contribute directly to the evaluation of conservation priorities. © 2014 John Wiley & Sons Ltd.

  20. Waterborne iron acquisition by a freshwater teleost fish, zebrafish Danio rerio.

    Science.gov (United States)

    Bury, Nicolas R; Grosell, Martin

    2003-10-01

    Waterborne iron accumulation by the gills of the zebrafish Danio rerio was assessed in ion-poor water. Branchial iron uptake, which comprises both the iron that has entered the gill cells and iron that is strongly bound to the epithelia, has high- and low-affinity components. At low nominal [Fe] (reducing agent dithiothreitol (DTT), branchial iron accumulation was significantly enhanced at [Fe]>15 nmol l(-1). The proton pump inhibitor bafilomycin A significantly reduced iron uptake in the presence of DTT. On the basis of these observations we conclude that branchial iron uptake at low [Fe] shows characteristics similar to those of other iron-transporting epithelia, coupling an apical membrane ferric reductase to a Fe(2+)/H(+) symporter. Zebrafish branchial iron transport at 18.6 nmol l(-1) was inhibited by 200 nmol l(-1) Cd(2+). But, unlike other Fe(2+)/H(+) symporters, iron uptake was not affected by other divalent metals (Co(2+), Ni(2+), Pb(2+), Cu(2+), Zn(2+) and Mn(2+)). Zebrafish loaded with (59)Fe from the water showed a loss of 7.9 pmol Fe g(-1) body mass over the first day and a further loss of 5.7 pmol Fe g(-1) body mass over the following 28 days. The depuration kinetics followed a two-component exponential model; for the short-lived component, t(1/2)=0.31 days, and for the long-lived component, t(1/2)=13.2 days. The daily iron loss by zebrafish can be compensated by iron uptake at exceedingly low water iron concentrations (uptake rate at 1.625 nmol l(-1) Fe=0.425 pmol g(-1) h(-1)), demonstrating that uptake of iron from the water is potentially an important source of this nutritive metal in freshwater teleost fish.

  1. Evaluation of the effects of pressure gradients on four Brazilian freshwater fish species

    Directory of Open Access Journals (Sweden)

    Paulo dos Santos Pompeu

    2009-02-01

    Full Text Available This work aimed to experimentally evaluate the behavior of Brazilian freshwater fish species when submitted to a gradual increase in pressure, as well as sudden decompression's effects simulating the passage through a hydroelectric turbine. Four species from the São Francisco river basin were tested: Astyanax bimaculatus, Hypostomus sp., Leporinus reinhardti and Prochilodus costatus. For all of them mortality rates due to decompression were extremely low. However, the symptoms related to decompression, such as bulged eyes and hemorrhage, were not observed only in Hypostomus sp., and were more frequent the larger the pressure values were, considering the values from which decompression was performed. All these symptoms decreased significantly after 24 h of observation. With the increase in pressure inside the apparatus, the four tested species moved towards the upper levels. This behavior could make possoble the implementation of bypass downstream fish passages in dams constructed in Brazil.Este trabalho teve como objetivo avaliar experimentalmente o comportamento de espécies brasileiras quando submetidas a um aumento gradual na pressão, bem como os efeitos de uma descompressão rápida simulando a passagem por uma turbina hidrelétrica. Quatro espécies da bacia do rio São Francisco foram testadas: Astyanax bimaculatus, Hypostomus sp., Leporinus reinhardti e Prochilodus costatus. Para todas elas as taxas de mortalidade devido à descompressão foram extremamente baixas. No entanto, sintomas relacionados à descompressão, como exoftalmia e hemorragia só não foram observados em Hypostomus sp., sendo mais freqüentes quanto maior o valor de pressão a partir do qual realizou-se a descompressão. Todos estes sintomas diminuíram significativamente após 24 horas de observação. Com o aumento da pressão no aparato, as espécies testadas se movimentaram em direção aos níveis superiores. Este comportamento sugere a possibilidade de se

  2. BIODIVERSITY AND CONSERVATION OF FRESHWATER FISH IN HONG KONG, CHINA%中国香港淡水鱼类的生物多样性与保护

    Institute of Scientific and Technical Information of China (English)

    VIRGINIA Laifun Lee; MARIA Lauching Young; TONY Kingtung Chan; SAMUEL Kinsan Lam; FRANCO Kwokyan Ng; JULIA Wingyin Chan

    2006-01-01

    We surveyed the distribution, composition and diversity of freshwater fish in Hong Kong, China from 2002 to 2004.Sites surveyed were mainly streams, marshes and estuaries. There are ponds for aquaculture and reservoirs in Hong Kong but no large natural water bodies. From the 220 sites surveyed, 114 species of 37 families were found. Gobiidae (with 24 species) and Cyprinidae (21 species) were the dominant families. This survey has increased the number of freshwater fish species recorded in Hong Kong to 167. Among these, 71 (42.5%) are primary freshwater fish, 44 are brackish and 46 are vagrants. The remaining 6 species are diadromous. In Hong Kong, freshwater fish are conserved by a combination of measures. About 38% of Hong Kong' s land area is designated as country parks and/or special areas, and is managed for nature conservation and educational purposes. In addition, another 5% of land area is zoned for conservation in the statutory land use zoning system to protect them from development and incompatible land uses. Major development projects have to go through the statutory environmental impact assessment process to ensure that they will not have adverse impact as far as practicable. There are conservation action plans for important species. For example, captive-bred individuals of the endemic Hong Kong Paradise Fish Macropodus hongkongensis have been released to suitable and secure sites inside country parks and their populations are regularly monitored. Other measures such as wetland creation, restoration and enhancement programmes are also implemented for freshwater fish conservation.

  3. An inventory of coastal freshwater fishes from Amapá highlighting the occurrence of eight new records for Brazil.

    Science.gov (United States)

    Melo, Bruno F; Benine, Ricardo C; Britzke, Ricardo; Gama, Cecile S; Oliveira, Claudio

    2016-01-01

    The Amazon Basin occupies a vast portion of northern South America and contains some of the highest species richness in the world. The northern Brazilian state of Amapá is delimited by the Amazonas River to the south, the Oyapock River to the northern boundary with French Guyana, and the Atlantic northeastern coast to Amazon estuary. Despite several expeditions to the Amazon in recent decades, little is known about the freshwater ichthyofauna from Amapá, with records limited to local inventories and species descriptions. This paper presents a compilation of the freshwater fish diversity sampled in fifteen sites covering two major Amapá ecoregions during the dry season of 2015. 120 species representing eight orders and 40 families are reported upon in this work. Eight species appear for the first time in the Brazilian territory providing new information for future conservation status evaluations.

  4. An inventory of coastal freshwater fishes from Amapá highlighting the occurrence of eight new records for Brazil

    Science.gov (United States)

    Melo, Bruno F.; Benine, Ricardo C.; Britzke, Ricardo; Gama, Cecile S.; Oliveira, Claudio

    2016-01-01

    Abstract The Amazon Basin occupies a vast portion of northern South America and contains some of the highest species richness in the world. The northern Brazilian state of Amapá is delimited by the Amazonas River to the south, the Oyapock River to the northern boundary with French Guyana, and the Atlantic northeastern coast to Amazon estuary. Despite several expeditions to the Amazon in recent decades, little is known about the freshwater ichthyofauna from Amapá, with records limited to local inventories and species descriptions. This paper presents a compilation of the freshwater fish diversity sampled in fifteen sites covering two major Amapá ecoregions during the dry season of 2015. 120 species representing eight orders and 40 families are reported upon in this work. Eight species appear for the first time in the Brazilian territory providing new information for future conservation status evaluations. PMID:27551225

  5. Fish diets in a freshwater-deprived semiarid estuary (The Coorong, Australia) as inferred by stable isotope analysis

    Science.gov (United States)

    Lamontagne, S.; Deegan, B. M.; Aldridge, K. T.; Brookes, J. D.; Geddes, M. C.

    2016-09-01

    In 2007, high rates of water extraction combined with a regional drought stopped freshwater discharge to the Coorong, a ∼120 km estuarine and coastal lagoon system at the outlet of the River Murray (Australia). The sources of organic matter sustaining the Coorong food web in the absence of river-borne organic matter and nutrient inputs were evaluated by measuring δ13C, δ15N and δ34S in large-bodied fish and their prey. In general, the δ34S of the food web (mean = 11.3‰; range = 4.32-18.9‰) suggested a comparable contribution from autochthonous pelagic (∼21‰) and benthic (organisms (-20 to -9.2‰) was also consistent with a dominant contribution from autochtonous sources to the food web. A Bayesian mixing model framework (SIMMR) was used to estimate the diet of large-bodied fish for statistically-determined prey groups based on their similarity in isotopic composition. Argyrosomus japonicus preyed primarily on Fish Group 1 (small pelagic fish like galaxiids and Hyperlophus vittatus), Rhombosolea tapirina on Invertebrate Group 2 (polychaetes like Capitella spp.) but Acanthopagrus butcheri fed on a wide variety of fish and invertebrate groups. A partial switch in diet to other prey groups suggested larger Ar. japonicus fed on larger prey, such as crabs and adult Aldrichetta forsteri. Despite being numerically abundant at the time, Fish Group 2 (benthic species) was a relatively low proportion of large-bodied fish diets. This probably reflected the tendency of some salt-tolerant members of this group (such as Atherinosoma microstoma) to prefer hypersaline habitats, which the large-bodied fish avoided. As the heavily preyed-on Fish Group 1 included species with a marine component to their life-cycle, marine productivity may also help to maintain this estuarine ecosystem in the absence of river-borne organic matter inputs.

  6. Risk assessment of non-native fishes in the Balkans Region using FISK, the invasiveness screening tool for non-native freshwater fishes

    Directory of Open Access Journals (Sweden)

    P. SIMONOVIC

    2013-06-01

    Full Text Available A high level of freshwater fish endemism in the Balkans Region emphasizes the need for non-native species risk assessments to inform management and control measures, with pre-screening tools, such as the Fish Invasiveness Screening Kit (FISK providing a useful first step. Applied to 43 non-native and translocated freshwater fishes in four Balkan countries, FISK reliably discriminated between invasive and non-invasive species, with a calibration threshold value of 9.5 distinguishing between species of medium and high risk sensu lato of becoming invasive. Twelve of the 43 species were assessed by scientists from two or more Balkan countries, and the remaining 31 species by a single assessor. Using the 9.5 threshold, three species were classed as low risk, 10 as medium risk, and 30 as high risk, with the latter category comprised of 26 moderately high risk, three high risk, and one very high risk species. Confidence levels in the assessments were relatively constant for all species, indicating concordance amongst assessors.

  7. The detection of dioxin- and estrogen-like pollutants in marine and freshwater fishes cultivated in Pearl River Delta, China

    Energy Technology Data Exchange (ETDEWEB)

    Wei, X.; Ching, L.Y. [Department of Biology, Hong Kong Baptist University, Kowloon (Hong Kong); Cheng, S.H. [Department of Biology and Chemistry, City University of Hong Kong (Hong Kong); Wong, M.H. [Department of Biology, Hong Kong Baptist University, Kowloon (Hong Kong); Croucher institute of Environmental Sciences, Hong Kong Baptist University, Kowloon (Hong Kong); Wong, Chris K.C., E-mail: ckcwong@hkbu.edu.h [Department of Biology, Hong Kong Baptist University, Kowloon (Hong Kong); Croucher institute of Environmental Sciences, Hong Kong Baptist University, Kowloon (Hong Kong)

    2010-06-15

    In this study we aimed to assess the dioxin- and estrogen-like activities of contaminants extracted from twenty species of freshwater and seawater fishes, using luciferase reporter assays. Transfected MCF7 cells were treated with sample extracts and luciferase activities were then measured at 24-h of post-treatment. The mean values of the detected dioxin- and estrogen-like activities in the freshwater fishes were 25.3 pg TEQ/g ww and 102.3 pM EEQ/g ww whereas in the seawater fishes, the values were 46.2 pg TEQ/g ww and 118.8 pM EEQ/g ww. Using sample-relevant dosage of estrogen, inductions of cell proliferation markers (i.e. retinoblastoma, cyclin D) and stimulations of cell growth were revealed by Western blotting, colony formation and BrdU uptake assays. A cotreatment with TCDD significantly reduced these effects. Using the sample extracts with different dioxin- and estrogen-like activities, similar observation was revealed. The data highlighted the mixture effect of food contaminants on human health. - The data reveals the potential risk of dietary intake of endocrine-disrupting chemicals.

  8. Fish community structure in freshwater karstic water bodies of the Sian Ka'an Reserve in the Yucatan peninsula, Mexico

    Science.gov (United States)

    Zambrano, L.; Vazquez-Dominguez, E.; Garcia-Bedoya, D.; Loftus, W.F.; Trexler, J.C.

    2006-01-01

    We evaluated the relationship between limnetic characteristics and fish community structure (based on species richness, abundance and individual size) in contrasting but interconnected inland aquatic habitats of freshwater karstic wetlands in the Yucatan peninsula, Mexico. In the western hemisphere, freshwater karstic wetlands are found in south-eastern Mexico, northern Belize, western Cuba, Andros Island, Bahamas and the Everglades of southern Florida. Only in the Everglades have fish communities been well described. Karstic wetlands are typically oligotrophic because calcium carbonate binds phosphorus, making it relatively unavailable for plants. Fourteen permanent and seasonally flooded water bodies were sampled in both wet and dry seasons in Sian Ka'an Biosphere Reserve, in the Mexican state of Quintana Roo. Water systems were divided by morphology in four groups: cenotes with vegetation (CWV), cenotes without vegetation (CNV), wetlands (WTL), and temporal cenotes (TPC). Discriminant analysis based on physical characteristics such as turbidity, temperature, depth and oxygen confirmed that these habitats differed in characteristics known to influence fish communities. A sample-based rarefaction test showed that species richness was significantly different between water systems groups, showing that WTL and CWV had higher richness values than CNV and TPC. The most abundant fish families, Poeciliidae, Cichlidae and Characidae, differed significantly in average size among habitats and seasons. Seasonal and inter-annual variation, reflecting temporal variation in rainfall, strongly influenced the environmental differences between shallow and deep habitats, which could be linked to fish size and life cycles. Five new records of species were found for the reserve, and one new record for Quintana Roo state. ?? 2006 by Verlag Dr. Friedrich Pfeil.

  9. Estimating cultural benefits from surface water status improvements in freshwater wetland ecosystems.

    Science.gov (United States)

    Roebeling, Peter; Abrantes, Nelson; Ribeiro, Sofia; Almeida, Pedro

    2016-03-01

    Freshwater wetlands provide crucial ecosystem services, though are subject to anthropogenic/natural stressors that provoke negative impacts on these ecosystems, services and values. The European Union Water Framework Directive aims to achieve good status of surface waters by 2015, through implementation of Catchment Management Plans. Implementation of Catchment Management Plans is costly, though associated benefits from improvements in surface water status are less well known. This paper establishes a functional relationship between surface water status and cultural ecosystem service values of freshwater systems. Hence, we develop a bio-economic valuation approach in which we relate ecological status and chemical status of surface waters (based on local physio-chemical and benthic macro-invertebrates survey data) to willingness-to-pay (using benefit-function transfer). Results for the Pateira de Fermentelos freshwater wetland (Portugal) show that the current status of surface waters is good from a chemical though only moderate from an ecological perspective. The current cultural ecosystem service value of the wetland is estimated at 1.54 m€/yr- increasing to 2.02 m€/yr in case good status of surface waters is obtained. Taking into account ecosystem services and values in decision making is essential to avoid costs from externalities and capture benefits from spill-overs--leading to more equitable, effective and efficient water resources management. Copyright © 2015 Elsevier B.V. All rights reserved.

  10. Two new genera of Paramphistomidae (Trematoda, Digenea from freshwater fish of Rondônia State, Brazil

    Directory of Open Access Journals (Sweden)

    Veron E. Thatcher

    1992-01-01

    Full Text Available Two new genera and species of Paramphistomidae (Trematoda, Digenea are described from freshwater fish of Rondônia State, Brazil. Pronamphistoma cichlasomae gen. et sp. nov. from Cichlasoma severum (Heckel is characterized as having a small, robust body with an anterior collar-like expansion, diverticula within the wall of the oral sucker and vitellaria in lateral fanshaped configurations. Micramphistoma ministoma gen. et sp. nov. from Hypopomus sp lacks oral diverticula, has anteriorly situated parallel tests and a very small postero-ventral acebtabulum. Neither of the new forms closely resembles any known genus.

  11. Climate warming reduces fish production and benthic habitat in Lake Tanganyika, one of the most biodiverse freshwater ecosystems.

    Science.gov (United States)

    Cohen, Andrew S; Gergurich, Elizabeth L; Kraemer, Benjamin M; McGlue, Michael M; McIntyre, Peter B; Russell, James M; Simmons, Jack D; Swarzenski, Peter W

    2016-08-23

    Warming climates are rapidly transforming lake ecosystems worldwide, but the breadth of changes in tropical lakes is poorly documented. Sustainable management of freshwater fisheries and biodiversity requires accounting for historical and ongoing stressors such as climate change and harvest intensity. This is problematic in tropical Africa, where records of ecosystem change are limited and local populations rely heavily on lakes for nutrition. Here, using a ∼1,500-y paleoecological record, we show that declines in fishery species and endemic molluscs began well before commercial fishing in Lake Tanganyika, Africa's deepest and oldest lake. Paleoclimate and instrumental records demonstrate sustained warming in this lake during the last ∼150 y, which affects biota by strengthening and shallowing stratification of the water column. Reductions in lake mixing have depressed algal production and shrunk the oxygenated benthic habitat by 38% in our study areas, yielding fish and mollusc declines. Late-20th century fish fossil abundances at two of three sites were lower than at any other time in the last millennium and fell in concert with reduced diatom abundance and warming water. A negative correlation between lake temperature and fish and mollusc fossils over the last ∼500 y indicates that climate warming and intensifying stratification have almost certainly reduced potential fishery production, helping to explain ongoing declines in fish catches. Long-term declines of both benthic and pelagic species underscore the urgency of strategic efforts to sustain Lake Tanganyika's extraordinary biodiversity and ecosystem services.

  12. Climate warming reduces fish production and benthic habitat in Lake Tanganyika, one of the most biodiverse freshwater ecosystems

    Science.gov (United States)

    Cohen, Andrew S.; Gergurich, Elizabeth L.; Kraemer, Benjamin M.; McGlue, Michael M.; McIntyre, Peter B.; Russell, James M.; Simmons, Jack D.; Swarzenski, Peter W.

    2016-01-01

    Warming climates are rapidly transforming lake ecosystems worldwide, but the breadth of changes in tropical lakes is poorly documented. Sustainable management of freshwater fisheries and biodiversity requires accounting for historical and ongoing stressors such as climate change and harvest intensity. This is problematic in tropical Africa, where records of ecosystem change are limited and local populations rely heavily on lakes for nutrition. Here, using a ∼1,500-y paleoecological record, we show that declines in fishery species and endemic molluscs began well before commercial fishing in Lake Tanganyika, Africa’s deepest and oldest lake. Paleoclimate and instrumental records demonstrate sustained warming in this lake during the last ∼150 y, which affects biota by strengthening and shallowing stratification of the water column. Reductions in lake mixing have depressed algal production and shrunk the oxygenated benthic habitat by 38% in our study areas, yielding fish and mollusc declines. Late-20th century fish fossil abundances at two of three sites were lower than at any other time in the last millennium and fell in concert with reduced diatom abundance and warming water. A negative correlation between lake temperature and fish and mollusc fossils over the last ∼500 y indicates that climate warming and intensifying stratification have almost certainly reduced potential fishery production, helping to explain ongoing declines in fish catches. Long-term declines of both benthic and pelagic species underscore the urgency of strategic efforts to sustain Lake Tanganyika’s extraordinary biodiversity and ecosystem services.

  13. Inventory of the freshwater fishes from a densely collected area in South America-a case study of the current knowledge of Neotropical fish diversity.

    Science.gov (United States)

    Bertaco, Vinicius A; Ferrer, Juliano; Carvalho, Fernando R; Malabarba, Luiz R

    2016-07-18

    We herein analyse the history of the description of the freshwater fish fauna from three drainages in one of the most densely collected areas of Brazil, and possibly of South America, the Rio Grande do Sul State, southern Brazil. An updated inventory of the freshwater fish species from rio Uruguay (partial) in Brazil, Laguna dos Patos (complete) and rio Tramandaí basins (complete) is presented. We found the number of new species described in these drainages increased nearly 56% since 1981, reaching a total of 422 species, but even now 10% of this number still corresponds to undescribed species. This rate of species description suggests that previous estimates of the Neotropical fish fauna are low, and we predict a final number of Neotropical fishes larger than the largest prediction estimate (8,000 species), after other regions of South and Central Americas become densely sampled. We discuss and attempt to demonstrate that species diversity knowledge is historically and strictly related to collecting efforts. We also demonstrate that the ecoregions in eastern South America with the highest density of species per area correspond to the areas more densely sampled in collections, and this may represent a bias in such kinds of analyses. This uneven sampling in Brazilian regions is apparently associated with the uneven distribution of Zoological research centers in different regions of the country. Small-sized species represents an important source of new species, along with little explored regions or little explored habitats, sometimes associated with restricted range species, and species complexes that need revisionary work. In contrast to other Neotropical regions, Atheriniformes are relatively diverse, sharing the fifth place in species richness with Gymnotiformes, and there is a remarkably high number of species of Rivulidae. Eight species are endemic to the rio Tramandaí drainage, 68 to the Laguna dos Patos system, and 78 to the rio Uruguay drainage. Almost 10

  14. Invasive species and habitat degradation in Iberian streams: an analysis of their role in freshwater fish diversity loss.

    Science.gov (United States)

    Hermoso, Virgilio; Clavero, Miguel; Blanco-Garrido, Francisco; Prenda, José

    2011-01-01

    Mediterranean endemic freshwater fish are among the most threatened biota in the world. Distinguishing the role of different extinction drivers and their potential interactions is crucial for achieving conservation goals. While some authors argue that invasive species are a main driver of native species declines, others see their proliferation as a co-occurring process to biodiversity loss driven by habitat degradation. It is difficult to discern between the two potential causes given that few invaded ecosystems are free from habitat degradation, and that both factors may interact in different ways. Here we analyze the relative importance of habitat degradation and invasive species in the decline of native fish assemblages in the Guadiana River basin (southwestern Iberian Peninsula) using an information theoretic approach to evaluate interaction pathways between invasive species and habitat degradation (structural equation modeling, SEM). We also tested the possible changes in the functional relationships between invasive and native species, measured as the per capita effect of invasive species, using ANCOVA. We found that the abundance of invasive species was the best single predictor of natives' decline and had the highest Akaike weight among the set of predictor variables examined. Habitat degradation neither played an active role nor influenced the per capita effect of invasive species on natives. Our analyses indicated that downstream reaches and areas close to reservoirs had the most invaded fish assemblages, independently of their habitat degradation status. The proliferation of invasive species poses a strong threat to the persistence of native assemblages in highly fluctuating environments. Therefore, conservation efforts to reduce native freshwater fish diversity loss in Mediterranean rivers should focus on mitigating the effect of invasive species and preventing future invasions.

  15. Page 1 Tropical Freshwater Biology, 7 (1998) 37-51 37 FISH ...

    African Journals Online (AJOL)

    KEY WORDS: fish diversity - distribution - abundance - River Jamieson -. Nigeria. ... The river flows all year round with the highest level and discharge during .... Mormyridae O 50 6 40 .... Studies On the fish community of River Ase, Bendel.

  16. Characterizing the early life history of an imperiled freshwater mussel (Ptychobranchus jonesi) with host-fish determination and fecundity estimation

    Science.gov (United States)

    Mcleod, John; Jelks, Howard; Pursifull, Sandra; Johnson, Nathan A.

    2017-01-01

    Conservation of imperiled species is frequently challenged by insufficient knowledge of life history and environmental factors that affect various life stages. The larvae (glochidia) of most freshwater mussels in the family Unionidae are obligate ectoparasites of fishes. We described the early life history of the federally endangered Southern Kidneyshell Ptychobranchus jonesi and compared methods for estimating fecundity and conducting host trials on this conglutinate-producing mussel species. Glochidial inoculation baths and direct feeding of conglutinates to Percina nigrofasciata, Etheostoma edwini, and Etheostoma fusiforme resulted in successful metamorphosis to the juvenile life stage. Ptychobranchus jonesi glochidia did not metamorphose on 25 other species of fishes tested representing 11 families. Three juveniles were recovered from Gambusia holbrooki resulting in a metamorphosis rate 90% for ≥5 d. Feeding conglutinates directly to fishes allowed us to estimate seminatural infestation rates and calculate average numbers of juveniles produced per conglutinate, unlike the traditional approach of infesting fish hosts in an inoculation bath. Regressions based on the physical dimensions of each conglutinate or conglutinate segment were the most practical method used to estimate fecundity. Species distribution information, early life-history description, and methods developed for determining fecundity and conducting host trials may assist in the conservation of P. jonesi during recovery options that include captive propagation, augmentation, and reestablishment.

  17. Cs-137 in freshwater fish in Finland, Norway and Faroe Islands with examples of ecological half-times

    Energy Technology Data Exchange (ETDEWEB)

    Saxen, R. [STUK (Finland); Liland, A.; Thoerring, H. [NRPA (Norway); Joensen, H.P. [Frodskaparsetur Foeroya (Faroe Islands)

    2005-07-01

    The deposition from Chernobyl in spring 1986 was most unevenly distributed in Finland and elevated the {sup 137}Cs contents of freshwater fishes significantly. Finland can be divided into five categories on the basis of the average deposition of {sup 137}Cs in each municipality. High activity concentrations of {sup 137}Cs still occur in fish in certain Finnish lakes in the areas of the highest deposition. The observed ecological half-times of {sup 137}Cs in perch in certain Finnish lakes varied by a factor of about three. The longest halftime of {sup 137}Cs in perch was approximately 9 years and the shortest approximately 3 years, determined for the time period of 1988-2002. The Norwegian lakes differ also from each other with respect to the decrease rates of {sup 137}Cs in fish. In some cases there were clearly two components in the reduction of {sup 137}Cs. Ecological half-times of {sup 137}Cs in trout and Arctic char varied from 1.4 y to 4.7 y in 1988-1994. There is an indication of somewhat more rapid reduction of {sup 137}Cs in fish in certain Norwegian lakes compared to Finnish ones, although ecological half-times for the Norwegian and for the Finnish lakes were estimated for different time intervals in the examples, and are thus not directly comparable. (au)

  18. Effects of nutritional status on metabolic rate, exercise and recovery in a freshwater fish

    Energy Technology Data Exchange (ETDEWEB)

    Gingerich, Andrew J.; Philipp, D. P.; Suski, C. D.

    2010-11-20

    The influence of feeding on swimming performance and exercise recovery in fish is poorly understood. Examining swimming behavior and physiological status following periods of feeding and fasting is important because wild fish often face periods of starvation. In the current study, researchers force fed and fasted groups of largemouth bass (Micropterus salmoides) of similar sizes for a period of 16 days. Following this feeding and fasting period, fish were exercised for 60 s and monitored for swimming performance and physiological recovery. Resting metabolic rates were also determined. Fasted fish lost an average of 16 g (nearly 12%) of body mass, while force fed fish maintained body mass. Force fed fish swam 28% further and required nearly 14 s longer to tire during exercise. However, only some physiological conditions differed between feeding groups. Resting muscle glycogen concentrations was twofold greater in force fed fish, at rest and throughout recovery, although it decreased in both feeding treatments following exercise. Liver mass was nearly three times greater in force fed fish, and fasted fish had an average of 65% more cortisol throughout recovery. Similar recovery rates of most physiological responses were observed despite force fed fish having a metabolic rate 75% greater than fasted fish. Results are discussed as they relate to largemouth bass starvation in wild systems and how these physiological differences might be important in an evolutionary context.

  19. Effects of nutritional status on metabolic rate, exercise and recovery in a freshwater fish.

    Science.gov (United States)

    Gingerich, Andrew James; Philipp, David P; Suski, Cory D

    2010-03-01

    The influence of feeding on swimming performance and exercise recovery in fish is poorly understood. Examining swimming behavior and physiological status following periods of feeding and fasting is important because wild fish often face periods of starvation. In the current study, researchers force fed and fasted groups of largemouth bass (Micropterus salmoides) of similar sizes for a period of 16 days. Following this feeding and fasting period, fish were exercised for 60 s and monitored for swimming performance and physiological recovery. Resting metabolic rates were also determined. Fasted fish lost an average of 16 g (nearly 12%) of body mass, while force fed fish maintained body mass. Force fed fish swam 28% further and required nearly 14 s longer to tire during exercise. However, only some physiological conditions differed between feeding groups. Resting muscle glycogen concentrations was twofold greater in force fed fish, at rest and throughout recovery, although it decreased in both feeding treatments following exercise. Liver mass was nearly three times greater in force fed fish, and fasted fish had an average of 65% more cortisol throughout recovery. Similar recovery rates of most physiological responses were observed despite force fed fish having a metabolic rate 75% greater than fasted fish. Results are discussed as they relate to largemouth bass starvation in wild systems and how these physiological differences might be important in an evolutionary context.

  20. 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.

  1. Phylogenetic analysis of aerobic freshwater and marine enrichment cultures efficient in hydrocarbon degradation: effect of profiling method

    NARCIS (Netherlands)

    Chang, Y.J.; Stephen, J.R.; Richter, A.P.; Venosa, A.D.; Bruggemann, J.; MacNaughton, S.J.; Kowalchuk, G.A.; Haines, J.R.; Kline, E.; White, D.C.

    2000-01-01

    Aerobically grown enrichment cultures derived from hydrocarbon- contaminated seawater and freshwater sediments were generated by growth on crude oil as sole carbon source. Both cultures displayed a high rate of degradation for a wide range of hydrocarbon compounds. The bacterial species composition

  2. Climate change impacts on freshwater fish, coral reefs, and related ecosystem services in the United States

    Science.gov (United States)

    We analyzed the potential physical and economic impacts of climate change on freshwater fisheries and coral reefs in the United States, examining a reference scenario and two policy scenarios that limit global greenhouse gas (GHG) emissions. We modeled shifts in suitable habitat ...

  3. Philometra mirabilis sp. n. (Nematoda: Philometridae), a new gonad-infecting parasite from the freshwater fish Cichla mirianae (Cichlidae) in Brazilian Amazon.

    Science.gov (United States)

    Moravec, František; Diggles, Ben

    2015-05-01

    A new nematode species, Philometra mirabilis sp. n. (Philometridae), is described based on a subgravid female specimen recovered from the ovary of the freshwater perciform fish Cichla mirianae Kullander and Ferreira (Cichlidae) in the Juruena River (Amazon River basin), State of Mato Grosso, Brazil. The new species is morphologically very different from congeners parasitizing fishes in South America, being mainly characterized by the markedly elongate, narrow body 171 mm long (maximum width/body length 1:598), the presence of three small cone-shaped oesophageal teeth protruding out of the mouth and an onion-shaped oesophageal inflation distinctly separated from the posterior part of the oesophagus, the relative length of the oesophagus, and the rounded posterior end of the body without any caudal projections. It is the third known valid species of Philometra Costa, 1845 parasitizing a freshwater fish in South America and the second species of this genus reported from fishes of the family Cichlidae.

  4. Cymothoa indica (Isopoda; Cymothoidae and Alitropus typus (Isopoda; Aegidae on freshwater fish Tilapia mossambica (Cichlidae in Vellar estuary, Southeast coast of India

    Directory of Open Access Journals (Sweden)

    G. Rameshkumar

    2010-09-01

    Full Text Available The study was carried out to establish the extent of double parasitation of two species of isopods Cymothoa indica and Alitropus typus on Tilapia mossambica. Cymothoa indica, a typical Indo-Pacific genus, and A. typus, a common crustacean parasite of fish in Southeast Asia, which feeds by sucking blood species, are reported by the first time in the freshwater fish Tilapia from Vellar estuary.

  5. Presence of lactobacilli in the intestinal content of freshwater fish from a river and from a farm with a recirculation system.

    Science.gov (United States)

    Bucio, Adolfo; Hartemink, Ralf; Schrama, Johan W; Verreth, Johan; Rombouts, Frans M

    2006-08-01

    Lactobacilli are Gram-positive and catalase negative rods commonly found in lactic acid fermented foods and in the gastrointestinal tract of mammals and birds. Few studies have described lactobacilli in freshwater fish. We analysed the presence of lactobacilli in the intestines of young and adult freshwater fish inhabiting a river environment and from fish reared in an aquaculture unit with a water recirculation system. Various species of lactobacilli were present in relatively high number in the intestines of edible fresh water fish from the river, especially in the warm season but in low numbers in the cold season. Lactobacilli were scarcely found in the intestines of edible farmed fish reared in a recirculation system in warm water. Lactobacilli are reported for the first time from the intestines of wild European eel, perch, rudd, ruffe, bleak, silver bream, chub, somnul and farmed African catfish. The two first fishes, and the last one are highly valuable species for fisheries and aquaculture. Additionally, improved methods for storage and bacteriological analysis of fish intestinal content are described. The natural presence of lactic acid bacteria in fish may be of great interest in producing fermented fish products worldwide.

  6. Cobalt Chloride Treatment Used to Ablate the Lateral Line System Also Impairs the Olfactory System in Three Freshwater Fishes.

    Science.gov (United States)

    Butler, Julie M; Field, Karen E; Maruska, Karen P

    2016-01-01

    Fishes use multimodal signals during both inter- and intra-sexual displays to convey information about their sex, reproductive state, and social status. These complex behavioral displays can include visual, auditory, olfactory, tactile, and hydrodynamic signals, and the relative role of each sensory channel in these complex multi-sensory interactions is a common focus of neuroethology. The mechanosensory lateral line system of fishes detects near-body water movements and is implicated in a variety of behaviors including schooling, rheotaxis, social communication, and prey detection. Cobalt chloride is commonly used to chemically ablate lateral line neuromasts, thereby eliminating water-movement cues to test for mechanosensory-mediated behavioral functions. However, cobalt acts as a nonspecific calcium channel antagonist and could potentially disrupt function of all superficially located sensory receptor cells, including those for chemosensing. Here, we examined whether CoCl2 treatment used to ablate the lateral line system also impairs olfaction in three freshwater fishes, the African cichlid fish Astatotilapia burtoni, goldfish Carassius auratus, and the Mexican blind cavefish Astyanax mexicanus. To examine the impact of CoCl2 on the activity of peripheral receptors, we quantified DASPEI fluorescence intensity of the olfactory epithelium from fish exposed to control and CoCl2 solutions. In addition, we examined brain activation in olfactory processing regions of A. burtoni immersed in either control or cobalt solutions. All three species exposed to CoCl2 had decreased DASPEI staining of the olfactory epithelium, and in A. burtoni, cobalt treatment caused reduced neural activation in olfactory processing regions of the brain. To our knowledge this is the first empirical evidence demonstrating that the same CoCl2 treatment used to ablate the lateral line system also impairs olfactory function. These data have important implications for the use of CoCl2 in future

  7. Cobalt Chloride Treatment Used to Ablate the Lateral Line System Also Impairs the Olfactory System in Three Freshwater Fishes.

    Directory of Open Access Journals (Sweden)

    Julie M Butler

    Full Text Available Fishes use multimodal signals during both inter- and intra-sexual displays to convey information about their sex, reproductive state, and social status. These complex behavioral displays can include visual, auditory, olfactory, tactile, and hydrodynamic signals, and the relative role of each sensory channel in these complex multi-sensory interactions is a common focus of neuroethology. The mechanosensory lateral line system of fishes detects near-body water movements and is implicated in a variety of behaviors including schooling, rheotaxis, social communication, and prey detection. Cobalt chloride is commonly used to chemically ablate lateral line neuromasts, thereby eliminating water-movement cues to test for mechanosensory-mediated behavioral functions. However, cobalt acts as a nonspecific calcium channel antagonist and could potentially disrupt function of all superficially located sensory receptor cells, including those for chemosensing. Here, we examined whether CoCl2 treatment used to ablate the lateral line system also impairs olfaction in three freshwater fishes, the African cichlid fish Astatotilapia burtoni, goldfish Carassius auratus, and the Mexican blind cavefish Astyanax mexicanus. To examine the impact of CoCl2 on the activity of peripheral receptors, we quantified DASPEI fluorescence intensity of the olfactory epithelium from fish exposed to control and CoCl2 solutions. In addition, we examined brain activation in olfactory processing regions of A. burtoni immersed in either control or cobalt solutions. All three species exposed to CoCl2 had decreased DASPEI staining of the olfactory epithelium, and in A. burtoni, cobalt treatment caused reduced neural activation in olfactory processing regions of the brain. To our knowledge this is the first empirical evidence demonstrating that the same CoCl2 treatment used to ablate the lateral line system also impairs olfactory function. These data have important implications for the use of

  8. First DNA Barcode Reference Library for the Identification of South American Freshwater Fish from the Lower Paraná River

    Science.gov (United States)

    Brancolini, Florencia; del Pazo, Felipe; Posner, Victoria Maria; Grimberg, Alexis; Arranz, Silvia Eda

    2016-01-01

    Valid fish species identification is essential for biodiversity conservation and fisheries management. Here, we provide a sequence reference library based on mitochondrial cytochrome c oxidase subunit I for a valid identification of 79 freshwater fish species from the Lower Paraná River. Neighbour-joining analysis based on K2P genetic distances formed non-overlapping clusters for almost all species with a ≥99% bootstrap support each. Identification was successful for 97.8% of species as the minimum genetic distance to the nearest neighbour exceeded the maximum intraspecific distance in all these cases. A barcoding gap of 2.5% was apparent for the whole data set with the exception of four cases. Within-species distances ranged from 0.00% to 7.59%, while interspecific distances varied between 4.06% and 19.98%, without considering Odontesthes species with a minimum genetic distance of 0%. Sequence library validation was performed by applying BOLDs BIN analysis tool, Poisson Tree Processes model and Automatic Barcode Gap Discovery, along with a reliable taxonomic assignment by experts. Exhaustive revision of vouchers was performed when a conflicting assignment was detected after sequence analysis and BIN discordance evaluation. Thus, the sequence library presented here can be confidently used as a benchmark for identification of half of the fish species recorded for the Lower Paraná River. PMID:27442116

  9. Description of Rhabdochona (Globochona) rasborae sp. n. (Nematoda: Rhabdochonidae) from the freshwater cyprinid fish Rasbora paviana Tirant in southern Thailand.

    Science.gov (United States)

    Moravec, Frantisek; Kamchoo, Kanda

    2012-09-01

    A new nematode species, Rhabdochona (Globochona) rasborae sp. n. (Rhabdochonidae), is described from the intestine of the freshwater cyprinid fish (sidestripe rasbora) Rasbora paviana Tirant in the Bangbaimai Subdistrict, Muang District, Surat Thani Province, southern Thailand. It differs from other representatives of the subgenus Globochona Moravec, 1972 which possess eggs provided with lateral swellings in having a spinose formation at the tail tip of both sexes and in some other morphological features, such as the body length of gravid female (8.6-23.7 mm), presence of two-three swellings on the egg, eight anterior prostomal teeth, length ratio of spicules (1:5.3-6.7) and arrangement of male genital papillae. This is the third nominal species of Rhabdochona Railliet, 1916 and the second species of the subgenus Globochona reported from fishes in Thailand. The three species of Rhabdochona recently described from fishes in Pakistan, viz. R. annai Kakar, Bilqees et Khan, 2012, R. bifurcatum [sic] Kakar et Bilqees, 2012, and R. pakistanica Kakar, Bilqees et Khan, 2012, are considered to be species inquirendae.

  10. Toxicity of Moringa oleifera seed extract on some hematological and biochemical profiles in a freshwater fish, Cyprinus carpio.

    Science.gov (United States)

    Kavitha, Chokkalingam; Ramesh, Mathan; Kumaran, Satyanarayanan Senthil; Lakshmi, Srinivasan Audhi

    2012-11-01

    The study was carried out to investigate the acute and sublethal toxicity of Moringa oleifera seed extract on hematological and biochemical variables of a freshwater fish Cyprinus carpio under laboratory conditions. The 96 h LC50 value of M. oleifera seed extract to the fish C. carpio was estimated by probit analysis method and was found to be 124.0 mg/L (with 95% confidence limits). For sublethal studies a non lethal dose of 1/10th of 96 h LC50 value (12.40 mg/L) was taken. During acute treatment (96 h), hematological variables like red blood cell count (RBC), hemoglobin (Hb), hematocrit (Hct), and mean corpuscular hemoglobin concentration (MCHC) were significantly (Pseed extract. However a significant (Pseed extract while a significant (Pseed extract exposed fish, whereas plasma protein level declined. However, a biphasic trend was noticed in Hb, Hct, RBC and MCHC levels. This study may provide baseline information about the toxicity of M. oleifera seed extract to C. carpio and to establish safer limit in water purification.

  11. Levels, distribution, and health risks of polycyclic aromatic hydrocarbons in four freshwater edible fish species from the Beijing market.

    Science.gov (United States)

    Wu, Wen-Jing; Qin, Ning; He, Wei; He, Qi-Shuang; Ouyang, Hui-Ling; Xu, Fu-Liu

    2012-01-01

    We first estimated the content of polycyclic aromatic hydrocarbons (PAHs) in the brain, liver, bladder, roe, and muscle of four species of edible freshwater fish from the Beijing market. The distribution characteristics of PAHs in these tissues and organs were analyzed to determine their health risks to humans. The results showed that the residual levels of wet weight and lipid-normalized weight ∑PAHs in various tissues of these fish ranged from 0.51 ng·g(-1) to 28.78 ng·g(-1) and from 93.62 ng·g(-1) to 8203.43 ng·g(-1), respectively. The wet weight contents of ∑PAHs were relatively higher in the brain and lower in the liver and muscle. But the differences were not significant. And the differences of lipid-normalized weight PAHs were significant, which in the bighead carp were found significantly the highest, followed in crucian carp, and the lowest in grass carp and carp. The contents of ∑PAHs were the highest in the liver and the lowest in the brain. In the tissues with a higher lipid content, higher residual levels of PAHs were found. The carcinogenic risks for humans from residual ∑PAHs in the various fish tissues were far below 10(-5).

  12. Accumulation and half-lives of 13 pesticides in muscle tissue of freshwater fishes through food exposure.

    Science.gov (United States)

    Lazartigues, Angélique; Thomas, Marielle; Banas, Damien; Brun-Bellut, Jean; Cren-Olivé, Cécile; Feidt, Cyril

    2013-04-01

    Fish are often exposed to various molecules like pesticides. Some of these compounds get biomagnified within aquatic food web, inducing health hazards of consumers. However, behaviors of many pesticides are still unknown. This work aims to study the uptake and the elimination of some of them in muscle tissue of edible fish (azoxystrobin, clomazone, diflufenican, dimethachlor, carbendazim, iprodion, isoproturon, mesosulfuron-methyl, metazachlor, napropamid, quizalofop, and thifensulfuron-methyl). Two freshwater fish species (Perca fluviatilis and Cyprinus carpio) were exposed to a mixture of these 13 pesticides, via multi-contaminated pellets, and then, eliminated. Compounds were measured in food, water and muscle tissue using multi-residues methods. Kinetics, biomagnification factors (BMFs) and half-lives (t1/2) were estimated and they did not show a large difference between the species. Muscular BMFs ranged from 2 × 10(-6) (mesosulfuron-methyl in perch) to 1 × 10(-3) (isoproturon and napropamid in perch) and t1/2 ranged from 0.8 (mesosulfuron-methyl in perch) to 40.3d (napropamid in carp). BMFs were also modeled as a function of Kow value. All BMF values were explained by the model, except for diflufenican which had a BMF lower than that expected by our modeling work, probably due to an efficient metabolism. Results led to the conclusion that none of these chemicals would probably be biomagnified within aquatic food webs.

  13. Size-based hydroacoustic measures of within-season fish abundance in a boreal freshwater ecosystem.

    Directory of Open Access Journals (Sweden)

    Riley A Pollom

    Full Text Available Eleven sequential size-based hydroacoustic surveys conducted with a 200 kHz split-beam transducer during the summers of 2011 and 2012 were used to quantify seasonal declines in fish abundance in a boreal reservoir in Manitoba, Canada. Fish densities were sufficiently low to enable single target resolution and tracking. Target strengths converted to log2-based size-classes indicated that smaller fish were consistently more abundant than larger fish by a factor of approximately 3 for each halving of length. For all size classes, in both years, abundance (natural log declined linearly over the summer at rates that varied from -0.067 x day(-1 for the smallest fish to -0.016 x day(-1 for the largest (R2 = 0.24-0.97. Inter-annual comparisons of size-based abundance suggested that for larger fish (>16 cm, mean winter decline rates were an order of magnitude lower (-0.001 x day(-1 and overall survival higher (71% than in the main summer fishing season (mean loss rate -0.038 x day(-1; survival 33%. We conclude that size-based acoustic survey methods have the potential to assess within-season fish abundance dynamics, and may prove useful in long-term monitoring of productivity and hence management of boreal aquatic ecosystems.

  14. The Implications of Ranaviruses to European farmed and wild freshwater fish

    DEFF Research Database (Denmark)

    Jensen, Ann Britt Bang

    fish species are susceptible to some or all of the ranaviruses tested, while other fish species were not found to be susceptible to infection with ranaviruses. Furthermore, virus could be re-isolated from several of the challenged fish even if no significant mortalities were observed. A separate study...... demonstrated that European stocks of the two fish species (redfin perch and rainbow trout) listed as susceptible to infection with epizootic haematopoietic necrosis virus did not show significant mortalities in bath challenges. These results are compared to published literature on ranavirus outbreaks...... fish from Asia. In the process of creating the model, a pathway for introduction was identified, and the potential risks of several ranaviruses were evaluated as part of a hazard identification process. This model used expert opinion to provide estimates of the probabilities of each step...

  15. Presence of lactobacilli in the intestinal content of freshwater fish from a river and from a farm with a recirculation system

    NARCIS (Netherlands)

    Bucio Galindo, A.; Hartemink, R.; Schrama, J.W.; Verreth, J.A.J.; Rombouts, F.M.

    2006-01-01

    Lactobacilli are Gram-positive and catalase negative rods commonly found in lactic acid fermented foods and in the gastrointestinal tract of mammals and birds. Few studies have described lactobacilli in freshwater fish. We analysed the presence of lactobacilli in the intestines of young and adult fr

  16. Aeromonas salmonicida subsp. salmonicida strains isolated from Chinese freshwater fish contain a novel genomic island and possible regional-specific mobile genetic elements profiles

    DEFF Research Database (Denmark)

    Long, Meng; Nielsen, Tue Kjærgaard; Leisner, Jørgen Johannes

    2016-01-01

    Two strains of Aeromonas salmonicida, YK and BG, were isolated from largemouth bronze gudgeon and northern whitefish in China, and identified as A. salmonicida subsp. salmonicida based on phylogenetic analysis of vapA and 16S rRNA gene sequences. YK and BG originated from freshwater fish, one of ...

  17. Toxicity of rotenone to giant river freshwater prawn Macrobrachium rosenbergii

    Science.gov (United States)

    Aquaculturists have often suffered predation losses in the production of freshwater giant river prawn Macrobrachium rosenbergii due to the presence of wild fish species in culture ponds. The piscicide rotenone is widely used to remove undesirable fish species from ponds. Although evidence in the t...

  18. A new species of Dactylogyrus (Monogenea: Dactylogyridae) parasitic on an endangered freshwater fish, Rhodeus atremius atremius, endemic to Japan.

    Science.gov (United States)

    Nitta, Masato; Nagasawa, Kazuya

    2016-10-01

    A new dactylogyrid monogenean Dactylogyrus bicorniculus sp. nov. is described from the gills of the kazetoge bitterling, Rhodeus atremius atremius (Jordan and Thompson, 1914), an endemic species in Japan, from Saga Prefecture, northern Kyūshū. D. bicorniculus sp. nov. resembles Dactylogyrus bicornis Malevitskaja, 1941 and Dactylogyrus lophogonus Zhang and Ji, 1980 because they have two common features, a large V-shaped ventral bar and well-developed second marginal hooks. However, the new species is distinguished from these congeners by a shorter penis and an accessory piece. A phylogenetic analysis of 28S rDNA shows that D. bicorniculus sp. nov. is a basal species with the T-shaped ventral bar in the genus. The new species has strict host-specificity to R. a. atremius, one of the endangered freshwater fishes in Japan, and may face the danger of co-extinction with its host.

  19. Kinetic characters and resistance to inhibition of crude and purified brain acetylcholinesterase of three freshwater fishes by organophosphates.

    Science.gov (United States)

    Shaonan, Li; Xianchuan, Xie; Guonian, Zhu; Yajun, Tan

    2004-07-14

    Acetylcholinesterase (AChE) was purified from the brain of three fresh-water fishes, topmouth gudgeon (Pseudorasbora parva), goldfish (Carassius auratus auratus) and rainbow trout (Oncorrhychus mykiss, formerly named Salmo gairdneri) by PEG2000/phosphate-salt two phases extraction, DEAE-Sephadex A-50 and Sephadex G-200 chromatography. Kinetic characters and resistance to inhibition of crude and purified enzymes by organophosphates were then studied. Although the crude enzyme from the trout displayed a different specific activity, kinetic curve, Vmax, and sensitivity to inhibition by oxidized malathion and triazopos compared with the two cyprinoids (i.e. topmouth gudgeon and goldfish), the purified enzymes of all the three species showed no significant difference in all aspects. The result suggested a negligible intrinsic difference of brain AChEs among the tested species.

  20. Role of catecholamines and nitric oxide on pigment displacement of the chromatophores of freshwater snakehead teleost fish, Channa punctatus.

    Science.gov (United States)

    Biswas, Saikat P; Jadhao, Arun G; Palande, Nikhil V

    2014-04-01

    We are reporting for the first time that the catecholamines (adrenaline and noradrenaline) inhibit the effect of nitric oxide (NO) on melanosome dispersion in freshly isolated scales of the freshwater snakehead fish, Channa punctatus. We studied the effect of NO and catecholamines on the pigment displacement by observing the changes in the melanophore index. The scales when treated with solution containing NO donor sodium nitroprusside (SNP) showed dispersion of melanosomes, whereas NO synthase blocker N-omega-Nitro-L-arginine suppresses this action of SNP. Treatment with adrenaline and noradrenaline on the isolated scales caused aggregation of melanosomes. Scales treated with solution containing catecholamines and SNP resulted in aggregation of melanosomes suggesting that catecholamines mask the effect of SNP. These results suggest that the catecholamines are inhibiting the effect of NO and causing the aggregation of the melanosomes may be via surface receptors.

  1. Automatic underwater radiotelemetry system to monitor temperature responses of fish in a freshwater environment

    Energy Technology Data Exchange (ETDEWEB)

    Prepejchal, W.; Thommes, M.M.; Spigarelli, S.A.; Haumann, J.R.; Hess, P.E.

    1980-11-01

    An automated radiotelemetry system developed to monitor body and water temperature of free-swimming fish is described. The receiving and data acquisition unit can be programmed to monitor as many as 16 transmitters (fish); each transmitter can time-multiply data from up to 9 resistive transducers. A typical transmitter with saddle-type attachment, suitable for fish weighing 1 to over 10 kg, has a submerged weight of less than 10 g. The typical range is 2700 m for fish 1 m below the surface. Complete schematics and operational logic are provided for the receiver and data processing printed circuit boards, for 3 types of fish transmitters, and for an environmental parameter monitor. Construction methods, calibration and tagging procedures, and the required computer programs are detailed. This system was in operation for 3 years at the Point Beach Nuclear Power Plant, Two Creeks, Wisconsin. Of the 89 fish tagged, 77 fish provided useable body and water temperature information with tracking times ranging from 0.5 to 505 hours. Modifications which would further improve the system's reliability are discussed.

  2. Automatic underwater radiotelemetry system to monitor temperature responses of fish in a freshwater environment

    Energy Technology Data Exchange (ETDEWEB)

    Prepejchal, W.; Thommes, M.M.; Spigarelli, S.A.; Haumann, J.R.; Hess, P.E.

    1980-11-01

    An automated radiotelemetry system developed to monitor body and water temperature of free-swimming fish is described. The receiving and data acquisition unit can be programmed to monitor as many as 16 transmitters (fish); each transmitter can time-multiply data from up to 9 resistive transducers. A typical transmitter with saddle-type attachment, suitable for fish weighing 1 to over 10 kg, has a submerged weight of less than 10 g. The typical range is 2700 m for fish 1 m below the surface. Complete schematics and operational logic are provided for the receiver and data processing printed circuit boards, for 3 types of fish transmitters, and for an environmental parameter monitor. Construction methods, calibration and tagging procedures, and the required computer programs are detailed. This system was in operation for 3 years at the Point Beach Nuclear Power Plant, Two Creeks, Wisconsin. Of the 89 fish tagged, 77 fish provided useable body and water temperature information with tracking times ranging from 0.5 to 505 hours. Modifications which would further improve the system's reliability are discussed.

  3. Physiological response of some economically important freshwater salmonids to catch-and-release fishing

    Science.gov (United States)

    Wedemeyer, G.A.; Wydoski, R.S.

    2008-01-01

    Catch-and-release fishing regulations are widely used by fishery resource managers to maintain both the quantity and quality of sport fish populations. We evaluated blood chemistry disturbances in wild brook trout Salvelinus fontinalis, brown trout Salmo trutta, cutthroat trout Oncorhynchus clarkii, and Arctic grayling Thymallus arcticus that had been hooked and played for 1-5 min in waters of the intermountain western United States. A hatchery stock of brown trout was included for comparison. To assess time needed for recovery, additional test groups were played for 5 min and then released into net-pens, where they were held for up to 72 h. The osmoregulatory and metabolic disturbances associated with catch-and-release fishing under the conditions we tested were minimal and judged to be well within normal physiological tolerance limits. In fish that were held for recovery, the blood chemistry alterations that did occur appeared to be related to stress from confinement in the net-pens. Our results confirm the results of previous studies, showing that prerelease air exposure and handling cause more physiological stress than does either hooking per se or playing time. Fishery managers must be aware of the differences in the perceptions, attitudes, and values of different societal groups, some of which feel that catch-and-release fishing should be banned because it is cruel to the animals. On the basis of brain anatomy, it seems highly unlikely that fish experience pain in the same manner as humans experience it, because fish lack a neocortex, the brain structure that enables the sensation of pain in higher vertebrates. However, independent of the neurobiological argument, our results indicate that under conditions similar to those tested, fish subjected to catch and release are neither suffering nor particularly stressed. Improved education programs about the relatively benign physiological effects of catch-and-release fishing as a fishery management practice would

  4. Paternal identity impacts embryonic development for two species of freshwater fish

    DEFF Research Database (Denmark)

    Siddique, Mohammad Abdul Momin; Linhart, Otomar; Krejszeff, Sławomir;

    2017-01-01

    Paternal, compared to maternal, contributions were believed to have only a limited influence on embryonic development and larval fitness traits in fishes. Therefore, the perspective of male influence on early life history traits has come under scrutiny. This study was conducted to determine paren...... into consideration for reproduction of these and likely other economically important fish species.......Paternal, compared to maternal, contributions were believed to have only a limited influence on embryonic development and larval fitness traits in fishes. Therefore, the perspective of male influence on early life history traits has come under scrutiny. This study was conducted to determine...

  5. Effects of the organophosphorous methyl parathion on the branchial epithelium of a freshwater fish Metynnis roosevelti

    Directory of Open Access Journals (Sweden)

    Machado Marcelo Rubens

    2003-01-01

    Full Text Available Gills are vital structures for fish, since they are the main site for gaseous exchange as well as partially responsible for osmorregulation, acid-basic balance, excretion of nitrogenous compounds and taste. Chemicals in the water may alter the morphology of branchial cells of fish that are, therefore, a useful model for environmental impact and ecotoxicology studies. In order to investigate the effects of an organophosphorous compound, methyl parathion, on the gills of the fish, samples of Metynnis roosevelti were exposed to lethal (7ppm and sublethal (1ppm doses of Mentox 600 CE. Through light and scanning electron microscopy, shrinking of the branchial epithelium, followed by detachment and hyperplasia were observed. Externally, the branchial filaments presented the gradual disappearance of microridges. Even in sublethal doses, the organophosphorous reduced the health and fitness of these fish, as consequence of secondary effects derived from changes in the branchial epithelium, impairing oxygenation and ionic balance of the organism.

  6. Freshwater aquaculture nurseries and infection of fish with zoonotic trematodes, Vietnam.

    Science.gov (United States)

    Phan, Van Thi; Ersbøll, Annette Kjær; Nguyen, Thanh Thi; Nguyen, Khue Viet; Nguyen, Ha Thi; Murrell, Darwin; Dalsgaard, Anders

    2010-12-01

    Residents of the Red River Delta region of northern Vietnam have a long tradition of eating raw fish. Fish-borne zoonotic trematodes (FZTs) are estimated to infect ≈1 million persons in Vietnam. It remains uncertain at what stages in the aquaculture production cycle fish become infected with FZTs. Newly hatched fish (fry) from 8 hatcheries and juveniles from 27 nurseries were therefore examined for FZT infection. No FZTs were found in fry from hatcheries. In nurseries, FZT prevalence in juveniles was 14.1%, 48.6%, and 57.8% after 1 week, 4 weeks, and when overwintered in ponds, respectively. FZT prevalence was higher in grass carp (paquaculture management practices, particularly in nurseries, to minimize the risk of distributing infected juveniles to grow-out ponds and, subsequently, to markets for human consumption.

  7. A Qualitative Meta-Analysis Reveals Consistent Effects of Atrazine on Freshwater Fish and Amphibians

    National Research Council Canada - National Science Library

    Jason R. Rohr; Krista A. McCoy

    .... In an effort to resolve the controversy, we conducted a qualitative meta-analysis on the effects of ecologically relevant atrazine concentrations on amphibian and fish survival, behavior, metamorphic...

  8. Dissolved organic carbon ameliorates the effects of UV radiation on a freshwater fish

    Energy Technology Data Exchange (ETDEWEB)

    Manek, Aditya K., E-mail: aditya.manek@usask.ca [Department of Biology, University of Saskatchewan, Saskatoon, S7N 5E2 SK (Canada); Ferrari, Maud C.O. [Department of Biomedical Sciences, WCVM, University of Saskatchewan, Saskatoon, S7N 5B4 SK (Canada); Chivers, Douglas P.; Niyogi, Som [Department of Biology, University of Saskatchewan, Saskatoon, S7N 5E2 SK (Canada)

    2014-08-15

    Anthropogenic activities over the past several decades have depleted stratospheric ozone, resulting in a global increase in ultraviolet radiation (UVR). Much of the negative effects of UVR in aquatic systems is minimized by dissolved organic carbon (DOC) which is known to attenuate UVR across the water column. The skin of many fishes contains large epidermal club cells (ECCs) that are known to play a role in innate immune responses and also release chemical alarm cues that warn other fishes of danger. This study investigated the effects of in vivo UVR exposure to fathead minnows (Pimephales promelas), under the influence of two sources of DOC: Sigma Aldrich humic acid, a coal based commercial source of DOC and Luther Marsh natural organic matter, a terrigenous source of DOC. Specifically, we examined ECC investment and physiological stress responses and found that fish exposed to high UVR, in the presence of either source of DOC, had higher ECC investment than fish exposed to high UVR only. Similarly, exposure to high UVR under either source of DOC, reduced cortisol levels relative to that in the high UVR only treatment. This indicates that DOC protects fish from physiological stress associated with UVR exposure and helps maintain production of ECC under conditions of UVR exposure. - Highlights: • We examined the combined effect of UV radiation and Dissolved Organic Carbon on fish. • Physiological stress response and epidermal club cell investment were measured. • Fish exposed to high UVR and DOC had higher ECC investment and reduced cortisol levels. • DOC plays a role in protecting fish from physiological stress and maintains ECC production.

  9. Understanding behavioral responses of fish to pheromones in natural freshwater environments.

    Science.gov (United States)

    Johnson, Nicholas S; Li, Weiming

    2010-10-01

    There is an abundance of experimental studies and reviews that describe odorant-mediated behaviors of fish in laboratory microcosms, but research in natural field conditions has received considerably less attention. Fish pheromone studies in laboratory settings can be highly productive and allow for controlled experimental designs; however, laboratory tanks and flumes often cannot replicate all the physical, physiological and social contexts associated with natural environments. Field experiments can be a critical step in affirming and enhancing understanding of laboratory discoveries and often implicate the ecological significance of pheromones employed by fishes. When findings from laboratory experiments have been further tested in field environments, often different and sometimes contradictory conclusions are found. Examples include studies of sea lamprey (Petromyzon marinus) mating pheromones and fish alarm substances. Here, we review field research conducted on fish pheromones and alarm substances, highlighting the following topics: (1) contradictory results obtained in laboratory and field experiments, (2) how environmental context and physiological status influences behavior, (3) challenges and constraints of aquatic field research and (4) innovative techniques and experimental designs that advance understanding of fish chemical ecology through field research.

  10. Understanding behavioral responses of fish to pheromones in natural freshwater environments

    Science.gov (United States)

    Johnson, Nicholas S.; Li, Weiming

    2010-01-01

    There is an abundance of experimental studies and reviews that describe odorant-mediated behaviors of fish in laboratory microcosms, but research in natural field conditions has received considerably less attention. Fish pheromone studies in laboratory settings can be highly productive and allow for controlled experimental designs; however, laboratory tanks and flumes often cannot replicate all the physical, physiological and social contexts associated with natural environments. Field experiments can be a critical step in affirming and enhancing understanding of laboratory discoveries and often implicate the ecological significance of pheromones employed by fishes. When findings from laboratory experiments have been further tested in field environments, often different and sometimes contradictory conclusions are found. Examples include studies of sea lamprey (Petromyzon marinus) mating pheromones and fish alarm substances. Here, we review field research conducted on fish pheromones and alarm substances, highlighting the following topics: (1) contradictory results obtained in laboratory and field experiments, (2) how environmental context and physiological status influences behavior, (3) challenges and constraints of aquatic field research and (4) innovative techniques and experimental designs that advance understanding of fish chemical ecology through field research.

  11. Arsenic in freshwater fish in the Chihuahua County water reservoirs (Mexico).

    Science.gov (United States)

    Nevárez, Myrna; Moreno, Myriam Verónica; Sosa, Manuel; Bundschuh, Jochen

    2011-01-01

    Water reservoirs in Chihuahua County, Mexico, are affected by some punctual and non-punctual geogenic and anthropogenic pollution sources; fish are located at the top of the food chain and are good indicators for the ecosystems pollution. The study goal was to: (i) determine arsenic concentration in fish collected from the Chuviscar, Chihuahua, San Marcos and El Rejon water reservoirs; (ii) to assess if the fishes are suitable for human consumption and (iii) link the arsenic contents in fish with those in sediment and water reported in studies made the same year for these water reservoirs. Sampling was done in summer, fall and winter. The highest arsenic concentration in the species varied through the sampling periods: Channel catfish (Ictalurus punctatus) with 0.22 ± 0.15 mg/kg dw in winter and Green sunfish (Lepomis cyanellus) with 2.00 ± 0.15 mg/kg dw in summer in El Rejon water reservoir. A positive correlation of arsenic contents was found through all sampling seasons in fish samples and the samples of sediment and water. The contribution of the weekly intake of inorganic arsenic, based on the consumption of 0.245 kg fish muscles/body weight/week was found lower than the acceptable weekly intake of 0.015 mg/kg/body weight for inorganic arsenic suggested by FAO/WHO.

  12. Influence of temperature and nutrient content on lipid production in freshwater microalgae cultures.

    Science.gov (United States)

    Bohnenberger, Juliana E; Crossetti, Luciane O

    2014-09-01

    The production of biomass by microalgae is considered a clean alternative compared to other plant crops that require large areas for cultivation and that generate environmental impacts. This study evaluated the influence of temperature and nutrients on lipid contents of cultured species of freshwater microalgae, with a view toward using these lipids for biodiesel production. Two strains of Monoraphidium contortum, a culture containing Chlorella vulgaris and Desmodesmus quadricauda and another strain of Microcystis aeruginosa were maintained in the laboratory for six days, in five culture media: modified ASM-1 (control, with high concentrations of phosphate and nitrate; phosphorus-deficient; non-limiting phosphate; nitrogen-deficient; and non-limiting nitrate). The cultures were then exposed to temperatures of 13°C, 25°C (control) and 37°C for eight days (n=3). Lipids were extracted by the cold-solvent (methanol and chloroform) method. On average, the highest total lipid yields were observed when the strains were maintained at 13°C and in the non-limiting nitrate medium. The lipid percentage varied depending on the concentration of algal biomass. This study showed that manipulation of controlling factors can increase the lipid concentration, optimizing the total production in order to use this raw material for biodiesel.

  13. Influence of temperature and nutrient content on lipid production in freshwater microalgae cultures

    Directory of Open Access Journals (Sweden)

    JULIANA E. BOHNENBERGER

    2014-09-01

    Full Text Available The production of biomass by microalgae is considered a clean alternative compared to other plant crops that require large areas for cultivation and that generate environmental impacts. This study evaluated the influence of temperature and nutrients on lipid contents of cultured species of freshwater microalgae, with a view toward using these lipids for biodiesel production. Two strains of Monoraphidium contortum, a culture containing Chlorella vulgaris and Desmodesmus quadricauda and another strain of Microcystis aeruginosa were maintained in the laboratory for six days, in five culture media: modified ASM-1 (control, with high concentrations of phosphate and nitrate; phosphorus-deficient; non-limiting phosphate; nitrogen-deficient; and non-limiting nitrate. The cultures were then exposed to temperatures of 13°C, 25°C (control and 37°C for eight days (n=3. Lipids were extracted by the cold-solvent (methanol and chloroform method. On average, the highest total lipid yields were observed when the strains were maintained at 13°C and in the non-limiting nitrate medium. The lipid percentage varied depending on the concentration of algal biomass. This study showed that manipulation of controlling factors can increase the lipid concentration, optimizing the total production in order to use this raw material for biodiesel.

  14. Morphology and small subunit rDNA-based phylogeny of Ceratomyxa amazonensis n. sp. parasite of Symphysodon discus, an ornamental freshwater fish from Amazon.

    Science.gov (United States)

    Mathews, Patrick D; Naldoni, Juliana; Maia, Antonio A; Adriano, Edson A

    2016-10-01

    The specious genus Ceratomyxa Thélodan, 1892, infect mainly gallbladder of marine fishes, with only five species reported infecting species from freshwater environment. This study performed morphological and phylogenetic analyses involving a new Ceratomyxa species (Ceratomyxa amazonensis n. sp.) found in gallbladder of Symphysodon discus Heckel, 1840 (Perciformes: Cichlidae), an important ornamental fish endemic to Amazon basin. Mature spores were strongly arcuate shaped and measured 7.0 ± 0.3 (6.2-7.6) μm in length, 15.8 ± 0.4 (15.0-16.7) μm in thickness, and polar capsules 3.22 ± 0.34 (2.4-3.6) μm in length and 2.63 ± 0.17 (2.4-2.9) μm in width. This was the first small subunit ribosomal DNA (SS rDNA) sequencing performed to Ceratomyxa species parasite of freshwater fish, and the phylogenetic analysis showed C. amazonensis n. sp. clustering in the early diverging subclade of the ceratomyxids, together with species of parasites of amphidromous/estuaries fishes, suggesting some role of the transition of the fishes between marine/freshwater environments in the evolutionary history of these parasites.

  15. Increased production of outer membrane vesicles by cultured freshwater bacteria in response to ultraviolet radiation.

    Science.gov (United States)

    Gamalier, Juliana P; Silva, Thiago P; Zarantonello, Victor; Dias, Felipe F; Melo, Rossana C N

    2017-01-01

    Secretion of membrane vesicles is an important biological process of both eukaryotic and prokaryotic cells. This process has been characterized in pathogenic bacteria, but is less clear in non-pathogenic bacteria from aquatic ecosystems. Here, we investigated, for the first time, the process of formation of outer membranes vesicles (OMVs), nanoscale vesicles extruded from the outer membrane (OM) of gram-negative bacteria, in cultures of freshwater bacteria after exposure or not to ultraviolet radiation (UVR) as an environmental stressor. Non-axenic cultures of freshwater bacteria isolated from a Brazilian aquatic ecosystem (Funil reservoir) were exposed or not to UVR (UVA+UVB) over a 3h period, during which cell density, viability and ultrastructure were analyzed. First, we showed that UVR induce bacterial death. UVR triggered significant negative effect on cell density after 3h of UVR treatment. This decrease was directly associated with cell death as revealed by a cell viability fluorescent probe that enables the distinction of live/dead bacteria. Transmission electron microscopy (TEM) revealed changes indicative of cell death after 3h of UVR exposure, with significant increase of damaged cells compared to the control group. Second, we demonstrated that gram-negative bacteria release OMVs during normal growth and after UVR exposure. OMVs were clearly identified as round, membrane-bound vesicles budding off from the bacterial OM as isolated or clustered vesicles or free in the extracellular medium. Remarkably, quantitative TEM analyses showed that bacteria respond to UVR with increased formation of OMVs. Moreover, while OMVs numbers per intact or damaged cell did not differ in the untreated group, UVR led to a higher vesiculation by bacteria in process of death. This means that degenerating bacteria release OMVs before lysis and that this secretion might be an adaptive/protective response to rapid changes in environmental conditions such as UV radiation. Copyright

  16. Application of sulphur isotope ratios to examine weaning patterns and freshwater fish consumption in Roman Oxfordshire, UK

    Science.gov (United States)

    Nehlich, Olaf; Fuller, Benjamin T.; Jay, Mandy; Mora, Alice; Nicholson, Rebecca A.; Smith, Colin I.; Richards, Michael P.

    2011-09-01

    This study investigates the application of sulphur isotope ratios (δ 34S) in combination with carbon (δ 13C) and nitrogen (δ 15N) ratios to understand the influence of environmental sulphur on the isotopic composition of archaeological human and faunal remains from Roman era sites in Oxfordshire, UK. Humans ( n = 83), terrestrial animals ( n = 11), and freshwater fish ( n = 5) were analysed for their isotope values from four locations in the Thames River Valley, and a broad range of δ 34S values were found. The δ 34S values from the terrestrial animals were highly variable (-13.6‰ to +0.5‰), but the δ 34S values of the fish were clustered and 34S-depleted (-20.9‰ to -17.3‰). The results of the faunal remains suggest that riverine sulphur influenced the terrestrial sulphur isotopic signatures. Terrestrial animals were possibly raised on the floodplains of the River Thames, where highly 34S-depleted sulphur influenced the soil. The humans show the largest range of δ 34S values (-18.8‰ to +9.6‰) from any archaeological context to date. No differences in δ 34S values were found between the males (-7.8 ± 6.0‰) and females (-5.3 ± 6.8‰), but the females had a linear correlation ( R2 = 0.71; p practices (including breastfeeding and weaning patterns) during the Romano-British Period.

  17. Rhabdochona (Rhabdochona) hypsibarbi n. sp. (Nematoda: Rhabdochonidae) from the freshwater cyprinid fish Hypsibarbus wetmorei (Smith) in northeast Thailand.

    Science.gov (United States)

    Moravec, František; Pachanawan, Adithepchaikarn; Kamchoo, Kanda

    2013-04-01

    A new nematode species, Rhabdochona (Rhabdochona) hypsibarbi n. sp. (Rhabdochonidae), is described from the intestine of the freshwater cyprinid fish Hypsibarbus wetmorei (Smith) in the Mekong River, Nakhon Phanom Province, northeast Thailand. It is mainly characterized by medium-sized, bifurcate deirids, the presence of 14 anterior prostomal teeth and distinct basal teeth, length ratio of the muscular and glandular portions of esophagus (1:6-9), length of the left spicule (669-774 μm), absence of a dorsal barb on the right spicule, length ratio of spicules (1:4.9-6.0), arrangement of genital papillae, and smooth eggs without filaments or swellings. In addition, specifically unidentified fourth-stage larvae of Rhabdochona (Rhabdochona) sp., morphologically similar to R. hypsibarbi, were recorded from the red-tailed tinfoil Barbonymus altus (Günther) (Cyprinidae) in the Mekong River, Nakhon Phanom Province, northeast Thailand. Rhabdochona hypsibarbi is the fourth nominal species of Rhabdochona Railliet, 1916 reported from fishes in Thailand and the second species of the nominotypical subgenus found in this country.

  18. Responses of antioxidant defense system to polyfluorinated dibenzo-p-dioxins (PFDDs) exposure in liver of freshwater fish Carassius auratus.

    Science.gov (United States)

    Li, Chenguang; Qin, Li; Qu, Ruijuan; Sun, Ping; Wang, Zunyao

    2016-04-01

    In this study, we evaluated the toxicity of ten polyfluorinated dibenzo-p-dioxins (PFDDs) congeners to freshwater fish Carassius auratus, by determining the antioxidative responses and lipid peroxidation in the liver after the fish were injected with two different concentrations (10 and 100 µmol/kg) of individual PFDDs for 3 and 14 days. The results showed that oxidative stress was obviously induced in some PFDDs-treated groups, as implied by the significantly inhibited antioxidants levels (superoxide dismutase, catalase, reduced glutathione, and glutathione S-transferase) and elevated malondialdehyde content. In addition, the oxidative stress inducing ability was variable for different PFDDs congeners, which was related with the substitution number and position of fluorine atom. Based on the calculated integrated biomarker response (IBR) values, the toxicity was ranked as 2,3,7,8-FDD>Octa-FDD>1,2,3,4,7-FDD>1,3,6,8-FDD>1,2,3,4,6,7-FDD>1,2,6,7-FDD>1,2,7-FDD>DD>2,7-FDD>2-FDD. This study can enhance the general understanding of the PFDDs induced oxidative stress in aquatic organisms.

  19. Influence of Dilution Rate on Enzymes of Intermediary Metabolism in Two Freshwater Bacteria Grown in Continuous Culture

    NARCIS (Netherlands)

    Matin, A.; Grootjans, A.; Hogenhuis, H.

    1976-01-01

    Two freshwater bacteria, a Pseudomonas sp. and a Spirillum sp., were grown in continuous culture under steady-state conditions in L-lactate-, succinate-, ammonium- or phosphate-limited media. In Pseudomonas sp., NAD-independent and NAD-dependent L-lactate dehydrogenases, aconitase, isocitrate dehydr

  20. Genetic diversity of cultured and wild populations of the freshwater prawn Macrobrachium rosenbergii based on microsatellite analysis

    Science.gov (United States)

    Freshwater prawn Macrobrachium rosenbergii culture in the Western Hemisphere is primarily, if not entirely, based on thirty-six individual prawn introduced to Hawaii from Malaysia in 1965 and 1966. Little information is available regarding the genetic background or current population status of cult...

  1. Detection of Vibrio Species Isolated from Ornamental Guppy Fish in Kashan, Isfahan, Iran Fish culturing Pounds

    Directory of Open Access Journals (Sweden)

    Samira Kiani

    2016-03-01

    Full Text Available Introduction: Gram-negative bacteria are the most pathogenic bacteria for marine organisms including ornamental fish. Materials and methods: In the present study Vibrio species isolated from ornamental guppy fish in Kashan, Isfahan, Iran fish ponds and were detected according to molecular detection and genetic alignment. Liver, kidney, skin, brain and gill samples were taken from ornamental guppy fish in Kashan, Isfahan, Iran. Samples were cultured on enriched culture media and purification steps were performed based on microbiological methods. Primary identification was done using biochemical characterization of the isolated bacteria. Molecular detection was done based on amplification of 16SrDNA sequence of Vibrio cholera genome containing ITS (internal transcribed spacer; and sequence alignment of the amplified nucleotides. Results: The isolated bacteria detected as Vibrio spp., including Vibrio cholera (99% sequence similarity, Vibrio alginolyticus, Vibrio mimicus and Vibrio parahaemolyticus (up to 90% similarity in the genome sequence. The aquaculture ponds had alkaline water and the amount of five-day BOD was not in a safe range, which are favorable conditions for Vibrio species. Discussion and conclusion: Aquatic organisms in Iran can be carriers of human pathogens such as Vibrio species. The results obtained in the present study and similar investigations should be mentioned in aquaculture healthcare systems.

  2. Sex identification and PIT-tagging: tools and prospects for studying intersexual differences in freshwater fishes

    DEFF Research Database (Denmark)

    Hulthén, K.; Chapman, B.B.; Nilsson, P.A.

    2014-01-01

    . The observed sex ratio of recaptured fish did not differ from the expected values of equal recapture rates between males and females. Hence, there is no observable evidence for an adverse effect of tagging close to the reproductive period and therefore this method is suitable for studying intersexual......This study evaluated a technique to allow the long-term monitoring of individual fishes of known sex in the wild using sex confirmation in close proximity to the reproductive period combined with individual tagging. Hundreds of partially migratory roach Rutilus rutilus were tagged with passive...... integrated transponders (PIT) following sex determination in spring and various performance measures were compared with fish tagged outside the reproductive period in autumn. Short-term survival was >95% for R. rutilus sexed and tagged under natural field conditions. Total length (LT) did not affect...

  3. Effects of low arsenic concentration exposure on freshwater fish in the presence of fluvial biofilms.

    Science.gov (United States)

    Tuulaikhuu, Baigal-Amar; Bonet, Berta; Guasch, Helena

    2016-02-15

    Arsenic (As) is a highly toxic element and its carcinogenic effect on living organisms is well known. However, predicting real effects in the environment requires an ecological approach since toxicity is influenced by many environmental and biological factors. The purpose of this paper was to evaluate if environmentally-realistic arsenic exposure causes toxicity to fish. An experiment with four different treatments (control (C), biofilm (B), arsenic (+As) and biofilm with arsenic (B+As)) was conducted and each one included sediment to enhance environmental realism, allowing the testing of the interactive effects of biofilm and arsenic on the toxicity to fish. Average arsenic exposure to Eastern mosquitofish (Gambusia holbrooki) was 40.5 ± 7.5 μg/L for +As treatment and 34.4 ± 1.4 μg/L for B+As treatment for 56 days. Fish were affected directly and indirectly by this low arsenic concentration since exposure did not only affect fish but also the function of periphytic biofilms. Arsenic effects on the superoxide dismutase (SOD) and glutathione reductase (GR) activities in the liver of mosquitofish were ameliorated in the presence of biofilms at the beginning of exposure (day 9). Moreover, fish weight gaining was only affected in the treatment without biofilm. After longer exposure (56 days), effects of exposure were clearly seen. Fish showed a marked increase in the catalase (CAT) activity in the liver but the interactive influence of biofilms was not further observed since the arsenic-affected biofilm had lost its role in water purification. Our results highlight the interest and application of incorporating some of the complexity of natural systems in ecotoxicology and support the use of criterion continuous concentration (CCC) for arsenic lower than 150 μg/L and closer to the water quality criteria to protect aquatic life recommended by the Canadian government which is 5 μg As/L.

  4. Freshwater fish as a dietary source of vitamin A in Cambodia

    DEFF Research Database (Denmark)

    Roos, Nanna; Chamnan, Chhoun; Loeung, Deap

    2007-01-01

    determined by high-performance liquid chromatography in samples of raw, whole fish from 29 fish species and in raw, edible parts from 24 species. Replicate samples were analysed in seven selected species. Two species, Parachela siamensis and Rasbora tornieri had very high vitamin A contents >1500 RAE/100 g...... of carotenoid bioefficacy for the control of vitamin A deficiency in developing countries. Journal of Nutrition, 132, 2920S-2926S]. Dehydroretinoids (vitamin A(2)) are not converted to all-trans-retinol but have similar metabolic functions. In this paper, RAE refers to the functional bioefficacy as defined...

  5. Metabolic effects of trichlorfon (Masoten®) on the neotropical freshwater fish pacu (Piaractus mesopotamicus).

    Science.gov (United States)

    Venturini, Francine P; Moraes, Fernanda D; Cortella, Lucas R X; Rossi, Priscila A; Cruz, Claudinei; Moraes, Gilberto

    2015-02-01

    Fish parasites are among the crucial limiting factors in aquaculture. The organophosphorous pesticide trichlorfon is widely used as an insecticide and against fish parasites worldwide. In this study, the effects of environmental trichlorfon on biochemical and physiological parameters were investigated in Piaractus mesopotamicus (pacu), a widely farmed fish in South America, through sublethal exposure (8 µg L(-1), 10 % of the LC50; 96 h) and recovery. The activity of brain acetylcholinesterase (AChE) was reduced after exposure (15.5 %) and remained decreased during the recovery (21.5 %). In white muscle, AChE activity decreased 31 % only after recovery. Alkaline phosphatase (ALP) and acid phosphatase (ACP) activities of the liver, muscle and plasma were steady during exposure. However, after the recovery period, ALP activity was increased in the liver and muscle and decreased in plasma, while ACP was increased in the liver and decreased in muscle. Intermediary metabolism was also affected by trichlorfon, depicting increase of energetic demand (hypoglycemia, neoglucogenesis and lipid catabolism), which remained even after recovery. These results indicate that P. mesopotamicus is adversely affected by sublethal concentrations of trichlorfon and are useful for assessing the impact as well as the pros and cons of its use in controlling fish parasites in aquaculture.

  6. Effects of illegal cyanide fishing on vitellogenin in the freshwater African catfish, Clarias gariepinus (Burchell, 1822).

    Science.gov (United States)

    Authman, Mohammad M N; Abbas, Wafaa T; Abumourad, Iman M K; Kenawy, Amany M

    2013-05-01

    The effects of cyanide, used in illegal fishing, on one of the most economically important Nile fishes, the African catfish (Clarias gariepinus), were studied. Cyanide impacts were evaluated in terms of biochemical, molecular and histopathological characteristics. After exposure to sublethal concentration (0.05mg/l) of potassium cyanide (KCN) for two and four weeks, GOT (glutamate oxaloacetate transaminase) was significantly increased in both male and female, while GPT (glutamate pyruvate transaminase), total plasma protein, phosphoprotein phosphorus (Vgt) in serum, vitellogenin gene expression (Vtg mRNA) and estrogen receptors (ER mRNA) were significantly decreased in female. On the other hand, male C. gariepinus showed a significant increase in Vtg and Vtg mRNA. Liver, testis and ovaries showed distinct histopathological changes. It was concluded that, cyanide caused damaging effects to fish and can cause serious disturbance in the natural reproduction and a drastic decline in fish population. Therefore, it is recommended that, the use of cyanide compounds must be prohibited to conserve the fisheries resources.

  7. Absence of fractionation of mercury isotopes during trophic transfer of methylmercury to freshwater fish in captivity

    Science.gov (United States)

    Kwon, Sae Yun; Blum, Joel D.; Carvan, Michael J.; Basu, Niladri; Head, Jessica A.; Madenjian, Charles P.; David, Solomon R.

    2012-01-01

    We performed two controlled experiments to determine the amount of mass-dependent and mass-independent fractionation (MDF and MIF) of methylmercury (MeHg) during trophic transfer into fish. In experiment 1, juvenile yellow perch (Perca flavescens) were raised in captivity on commercial food pellets and then their diet was either maintained on unamended food pellets (0.1 μg/g MeHg) or was switched to food pellets with 1.0 μg/g or 4.0 μg/g of added MeHg, for a period of 2 months. The difference in δ202Hg (MDF) and Δ199Hg (MIF) between fish tissues and food pellets with added MeHg was within the analytical uncertainty (δ202Hg, 0.07 ‰; Δ199Hg, 0.06 ‰), indicating no isotope fractionation. In experiment 2, lake trout (Salvelinus namaycush) were raised in captivity on food pellets and then shifted to a diet of bloater (Coregonus hoyi) for 6 months. The δ202Hg and Δ199Hg of the lake trout equaled the isotopic composition of the bloater after 6 months, reflecting reequilibration of the Hg isotopic composition of the fish to new food sources and a lack of isotope fractionation during trophic transfer. We suggest that the stable Hg isotope ratios in fish can be used to trace environmental sources of Hg in aquatic ecosystems.

  8. Sex identification and PIT-tagging: tools and prospects for studying intersexual differences in freshwater fishes.

    Science.gov (United States)

    Hulthén, K; Chapman, B B; Nilsson, P A; Hansson, L-A; Skov, C; Baktoft, H; Brodersen, J; Brönmark, C

    2014-02-01

    This study evaluated a technique to allow the long-term monitoring of individual fishes of known sex in the wild using sex confirmation in close proximity to the reproductive period combined with individual tagging. Hundreds of partially migratory roach Rutilus rutilus were tagged with passive integrated transponders (PIT) following sex determination in spring and various performance measures were compared with fish tagged outside the reproductive period in autumn. Short-term survival was >95% for R. rutilus sexed and tagged under natural field conditions. Total length (LT ) did not affect the probability of survival within the size range tagged (119-280 mm), nor were there differences in timing of migration the following season between individuals sexed and tagged in spring and individuals tagged in autumn (i.e. outside the reproductive period). Also, a similar per cent of R. rutilus sexed and tagged in spring and tagged in autumn migrated the following season (34·5 and 34·7%). Moreover, long-term recapture data revealed no significant differences in body condition between R. rutilus individuals sexed and tagged in spring, individuals tagged in autumn and unmanipulated individuals. The observed sex ratio of recaptured fish did not differ from the expected values of equal recapture rates between males and females. Hence, there is no observable evidence for an adverse effect of tagging close to the reproductive period and therefore this method is suitable for studying intersexual differences and other phenotypic traits temporarily expressed during reproduction at the individual level in fishes.

  9. EFFECTS OF THE HEAVY METAL, ZINC, ON THE FRESHWATER FISH TILAPIA NILOTICA L.

    Directory of Open Access Journals (Sweden)

    VIRGINIA S. CARING

    1992-01-01

    Full Text Available Gills, gonads, and blood of Tilapia nilotica exposed to different concentrations of zinc sulfate (ZnSO4. 7H2O exhibited histological effects. Gills of posthatch larvae exposed chronically for 21 days to 2 ppm zinc sulfate and fingerlings to 10 ppm sublethal zinc concentrations exhibited hyperplasia that resulted in fusion of adjacent secondary gill lamellae. The same effects were observed in 4-hour short-term exposure to 30 ppm lethal dose. Posthatch larvae subjected to 2 and 5 ppm sublethal levels of zinc for 30 days retained undifferentiated gonads with differentiation with oogonial proliferation. Ovaries of control fish demonstrated healthy oocyte growth and other normal histological features after 57 days. In contrast, ovaries in treated groups exhibited excessive amounts of connective tissue, hyperemia and markedly reduced oocyte number. Oocytes had wavy irregular surface outlines. Deviation from normal was observed to be dose dependent. In juvenile tilapia, spermatogenesis was observed in control testes. Testes of zinc-exposed fish, on the other hand, remained immature. Hyperemia was markedly pronounced in both testes and ovary after 90 days exposure to zinc. Blood of Tilapia nilotica fingerlings exposed to sublethal concentrations of 2, 5, and 10 ppm zinc for 30, 60, and 90 days exhibited anisocytosis and poikilocytosis. There was an increase in hematocrit values in zinc-reared fish which, however, reverted to control/near control levels at day 90. Hemoglobin values were inversely proportional to the level of zinc in the rearing water. The marked reduction in hemoglobin values in fish reared at the higher zinc concentrations of 5 and 10 ppm suggests the development of some degree of anemia which is also supported by the observations of anisocytosis and poikilocytosis. INTRODUCTION Heavy metal contamination of aquatic environments has become a current serious problem because of increased industrialization. In the Philippines, data gathered

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

    Science.gov (United States)

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

    2017-09-01

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

  11. Molecular phylogeny and phylogeography of the Australian freshwater fish genus Galaxiella, with an emphasis on dwarf galaxias (G. pusilla.

    Directory of Open Access Journals (Sweden)

    Peter J Unmack

    Full Text Available The freshwater fauna of Southern Australia is primarily restricted to the southwestern and southeastern corners of the continent, and is separated by a large, arid region that is inhospitable to this biota. This geographic phenomenon has attracted considerable interest from biogeographers looking to explain evolutionary diversification in this region. Here, we employed phylogenetic and phylogeographic approaches to evaluate the effect of this barrier on a group of four galaxiid fish species (Galaxiella endemic to temperate Southern Australia. We also tested if continental shelf width has influenced connectivity among populations during low sea levels when rivers, now isolated, could have been connected. We addressed these questions by sampling each species across its range using multiple molecular markers (mitochondrial cytochrome b sequences, nuclear S7 intron sequences, and 49 allozyme loci. These data also allowed us to assess species boundaries, to refine phylogenetic affinities, and to estimate species ages. Interestingly, we found compelling evidence for cryptic species in G. pusilla, manifesting as allopatric eastern and western taxa. Our combined phylogeny and dating analysis point to an origin for the genus dating to the early Cenozoic, with three of the four species originating during the Oligocene-Miocene. Each Galaxiella species showed high levels of genetic divergences between all but the most proximate populations. Despite extensive drainage connections during recent low sea levels in southeastern Australia, populations of both species within G. pusilla maintained high levels of genetic structure. All populations experienced Late Pleistocene-Holocene population growth, possibly in response to the relaxation of arid conditions after the last glacial maximum. High levels of genetic divergence and the discovery of new cryptic species have important implications for the conservation of this already threatened group of freshwater

  12. Molecular phylogeny and phylogeography of the Australian freshwater fish genus Galaxiella, with an emphasis on dwarf galaxias (G. pusilla).

    Science.gov (United States)

    Unmack, Peter J; Bagley, Justin C; Adams, Mark; Hammer, Michael P; Johnson, Jerald B

    2012-01-01

    The freshwater fauna of Southern Australia is primarily restricted to the southwestern and southeastern corners of the continent, and is separated by a large, arid region that is inhospitable to this biota. This geographic phenomenon has attracted considerable interest from biogeographers looking to explain evolutionary diversification in this region. Here, we employed phylogenetic and phylogeographic approaches to evaluate the effect of this barrier on a group of four galaxiid fish species (Galaxiella) endemic to temperate Southern Australia. We also tested if continental shelf width has influenced connectivity among populations during low sea levels when rivers, now isolated, could have been connected. We addressed these questions by sampling each species across its range using multiple molecular markers (mitochondrial cytochrome b sequences, nuclear S7 intron sequences, and 49 allozyme loci). These data also allowed us to assess species boundaries, to refine phylogenetic affinities, and to estimate species ages. Interestingly, we found compelling evidence for cryptic species in G. pusilla, manifesting as allopatric eastern and western taxa. Our combined phylogeny and dating analysis point to an origin for the genus dating to the early Cenozoic, with three of the four species originating during the Oligocene-Miocene. Each Galaxiella species showed high levels of genetic divergences between all but the most proximate populations. Despite extensive drainage connections during recent low sea levels in southeastern Australia, populations of both species within G. pusilla maintained high levels of genetic structure. All populations experienced Late Pleistocene-Holocene population growth, possibly in response to the relaxation of arid conditions after the last glacial maximum. High levels of genetic divergence and the discovery of new cryptic species have important implications for the conservation of this already threatened group of freshwater species.

  13. The influence of douchi starter cultures on the composition of extractive components, microbiological activity, and sensory properties of fermented fish pastes.

    Science.gov (United States)

    Kasankala, Ladislaus M; Xiong, Youling L; Chen, Jie

    2011-01-01

    Three experiments were conducted to test the hypothesis that douchi cultures could serve as a potential starter for enhancing the quality attributes of fermented silver carp meat. In experiment 1, an active, prefermented douchi culture was incorporated into a fish paste to aid in the fish fermentation (30 d) and facilitate biochemical production of extractive flavor components (PRF). In experiment 2, a fully fermented (30 d) douchi was added to a fish paste and the mixture was fermented for 30 d (PSF). In experiment 3, a fish paste without the douchi culture was fermented for 30 d (CF). Total extracted free amino acids increased by 68.0, 68.6, and 78.8% (P 100 mg/mL). The concentrations of both formaldehyde-reactive nitrogen and ammonia nitrogen extractives increased significantly (P PSF > CF. Low amounts of biogenic amines (ingredient commonly used in China, Japan, and other Asian countries. It is also used in many Chinese cuisines in the United States. On the other hand, fermented seafood made from freshwater fish such as silver carp is known to contain bioactive components believed to promote health. The findings from the present study indicated that douchi as a novel starter can be used to produce fermented silver carp fish pastes with excellent flavor and consumer acceptability. The results may be applicable to other fish species to produce similar fermentation products.

  14. Laboratory Experiments on the Effects of Blade Strike from Hydrokinetic Energy Technologies on Larval and Juvenile Freshwater Fishes

    Energy Technology Data Exchange (ETDEWEB)

    Schweizer, Peter E [ORNL; Cada, Glenn F [ORNL; Bevelhimer, Mark S [ORNL

    2012-03-01

    will make contact with the rotor blade or will bypass the blade while entrained in the boundary layer of water flowing over the blade surface. The study quantified both immediate and delayed mortalities (observed immediately, 3 hours, and 24 hours after encountering the blade) among freshwater YOY fish resulting from contact with the blade or turbulent flows in the wake of the blade.

  15. Spatial and temporal characterization of fish assemblages in a tropical coastal system influenced by freshwater inputs: northwestern Yucatan peninsula

    Directory of Open Access Journals (Sweden)

    Daniel Arceo-Carranza

    2009-06-01

    Full Text Available Coastal lagoons are important systems for freshwater, estuarine and marine organisms; they are considered important zones of reproduction, nursery and feeding for many fish species. The present study investigates the fish assemblages of the natural reserve of Dzilam and their relationship with the hydrologic variables. A total of 6 474 individuals (81 species were collected, contributing with more than 50% considering the Importance Value Index (IVI, Sphoeroides testudineus, Fundulus persimilis, Anchoa mitchilli, Eucinostomus gula, Eucinostomus argenteus and Mugil trichodon. Differences in species composition were found between seasons the highest during the cold fronts. Spatially, differences were related with the presence of freshwater seeps, the highest in the ecological characterized eastern part and the lowest with higher difference in specific composition located in the western part of the internal zone, due to a higher abundance and dominance of L. rhomboides. Salinity and temperature were the variables that presented a higher influence in the distribution of some pelagic species such as A. mitchilli and A. hepsetus. Because of the abundant freshwater seeps characteristic of the coastal lagoons of Yucatan Peninsula their community structure and fish assemblage display spatial and temporal differences in specific composition. Rev. Biol. Trop. 57 (1-2: 89-103. Epub 2009 June 30.Las lagunas costeras son sistemas importantes para muchas especies de organismos dulceacuícolas, estuarinos y marinos, ya que son consideradas zonas de reproducción, refugio y alimentación de muchas especies de peces. El presente estudio analizó los ensamblajes de la comunidad íctica de la reserva de Dzilam y su relación con las variables hidrológicas. Se capturaron un total de 6 474 individuos (81 especies, en donde Sphoeroides testudineus, Fundulus persimilis, Anchoa mitchilli, Eucinostomus gula, Eucinostomus argenteus and Mugil trichodon contribuyeron con m

  16. Self-confidence of anglers in identification of freshwater sport fish

    Science.gov (United States)

    Chizinski, C.J.; Martin, D. R.; Pope, Kevin L.

    2014-01-01

    Although several studies have focused on how well anglers identify species using replicas and pictures, there has been no study assessing the confidence that can be placed in angler's ability to identify recreationally important fish. Understanding factors associated with low self-confidence will be useful in tailoring education programmes to improve self-confidence in identifying common species. The purposes of this assessment were to quantify the confidence of recreational anglers to identify 13 commonly encountered warm water fish species and to relate self-confidence to species availability and angler experience. Significant variation was observed in anglers self-confidence among species and levels of self-declared skill, with greater confidence associated with greater skill and with greater exposure. This study of angler self-confidence strongly highlights the need for educational programmes that target lower skilled anglers and the importance of teaching all anglers about less common species, regardless of skill level.

  17. Histopathological changes in the gill and liver tissues of freshwater fish, Cirrhinus mrigala exposed to dichlorvos

    Directory of Open Access Journals (Sweden)

    Babu Velmurugan

    2009-10-01

    Full Text Available The histopathological effects of dichlorvos, an organophosphate pesticide, on the gill and liver tissues in Cirrhinus mrigala were determined by light microscopy. The fishes were exposed to sublethal concentrations (0.91 and 1.82 ppm of dichlorvos for 10 days with parallel untreated control. No histopathological effects were observed in control group. Hyperplasia, desquamation, and necrosis of epithelial, epithelial lifting, oedema, lamellar fusion, collapsed secondary lamellae, curling of secondary lamellae and aneurism in the secondary lamellae were observed in gill tissues exposed to dichlorvos. Hepatic lesions in the liver tissues of fishes exposed to dichlorvos were characterized by cloudy swelling of hepatocytes, congestion, vacuolar degeneration, karyolysis, karyohexis, dilation of sinusoids and nuclear hypertrophy.

  18. An annotated distributional checklist of exotic freshwater fishes from the Baja California Peninsula, Mexico

    OpenAIRE

    Gorgonio Ruiz-Campos; Salvador Contreras-Balderas; Asunción Andreu-Soler; Alejandro Varela-Romero; Ernesto Campos

    2012-01-01

    We documented the distributional status of 27 exotic fish species in the inland waters of the Baja California Peninsula, Mexico, based on voucher specimens collected from 122 sites between 1977 and 2010, and on published records. The species reported here are representatives of genera from the Atlantic drainages of North America (Ictalurus, Ameiurus, Pylodictis, Morone, Lepomis, Pomoxis, Dorosoma, Cyprinella, and Micropterus), Middle America (Poecilia, Gambusia, and Xiphophorus), Eurasia (Cyp...

  19. TOXICITY OF ZINC ON THE BIOCHEMICAL CONTENTS OF CERTAIN TISSUES OF FRESHWATER FISH, CHANNA GACHUA (HAM.

    Directory of Open Access Journals (Sweden)

    Kawade S. J

    2012-08-01

    Full Text Available Industrial effluent containing heavy metals, on entering aquatic environment causes biochemical disturbances in the fish. The present study deals with the toxicity of Zinc as (ZnSO4, as a component of industrial waste and its effect on tissue glycogen and protein level at 24, 48, 72 & 96 hrs respectively .The estimated glycogen and protein concentration in the tissues- gills, liver, kidney, ovary and testis were found to be reduced during the exposure periods.

  20. Impacts of Malathion on Mortality and BiochemicalL Changes of Freshwater Fish Labeo Rohita

    Directory of Open Access Journals (Sweden)

    S. Arun

    2011-10-01

    Full Text Available Malathion was used in vivo on fresh water fish Labeo rohita to study its toxicity. The acute toxicity tests were conducted during certain intervals in various concentrations (5, 10, 15, 20, 25 and 30 mg/L of malathion. The physical and chemical analyses of water were carried out by following APHA methods. While treating with malathion, the percentage of fish mortality was assessed during 24, 48, 72 and 96 hours. The lethal and sub-lethal concentration of malathion were found to be LC100 (25 mg/L and LC0 (5 mg/L, respectively. The antioxidant enzyme activity (Catalase 43.1±2.3, 16.5±0.57, 23.9±0.17 μ moles of phenol liberated/min/100mg protein and Glutathion-S-transferase (GST 270.5±0.16, 143.2±1.03, 215.5±0.72 μ moles of phenol liberated/min/100mg protein, in the liver, muscle and gill, respectively increased during the accumulation of malathion, whereas it decreased (Catalase 17±1.44, 7.9±0.23, 10.7±0.69 μ moles of phenol liberated/min/100mg protein and GST 219.5±1.12, 108.1±0.34, 160.2±0.46 μ moles of phenol liberated/min/100mg protein during depuration period. The effects of malathion resulted in the gradual decrease of nucleic acids, protein, free amino acids (FAA and glycogen. During recovery period, the levels of biochemical components progressively increased indicating a probable recovery from the disruption of internal organ. Hence, the pesticide intoxication has made a disturbance in normal functioning of cells with significant alterations in the fundamental biochemical mechanisms of fish. It suggests that the continuous exposure of pesticide leads to abnormal changes causing fish to death.

  1. Fish communities in coastal freshwater ecosystems: the role of the physical and chemical setting

    OpenAIRE

    Arend Kristin K; Bain Mark B

    2008-01-01

    Abstract Background We explored how embayment watershed inputs, morphometry, and hydrology influence fish community structure among eight embayments located along the southeastern shoreline of Lake Ontario, New York, USA. Embayments differed in surface area and depth, varied in their connections to Lake Ontario and their watersheds, and drained watersheds representing a gradient of agricultural to forested land use. Results We related various physicochemical factors, including total phosphoru...

  2. Molecular phylogeny and host specificity of the larval Eustrongylides (Nematoda: Dioctophmidae) from freshwater fish in China.

    Science.gov (United States)

    Xiong, Fan; Li, Wen X; Wu, Shan G; Zou, Hong; Wang, Gui T

    2013-02-01

    The nematodes Eustrongylides spp. collected from different fish species in China were examined for their intra- and interspecific evolutionary variations using the molecular markers mitochondrial cytochrome oxidase c subunit 1 (COI) gene and internal transcribed spacer (ITS) rDNA regions. The phylogenetic analysis indicated that Eustrongylides species are divided into 3 well-supported clades. The ITS divergence between the clades suggested that clades 2 and 3 might represent the same species, whereas clade 1 represent another cryptic species. The host specificity of these nematodes was analyzed according to prevalence data, host range, and phylogenetic information. Clade 1 was found in 4 fish species, i.e., Odontobutis obscurus, Silurus asotus, Culter mongolicus, and Acanthogobius flavimanus, but was predominant in the 2 perciform species, O. obscurus and A. flavimanus. Clade 2 was found in 3 fish species, Monopterus albus, Channa argus, and Channa asiatica, but was predominant in M. albus, reported to feed primarily on oligochaetes, the first intermediate host of Eustrongylides sp. Clade 3 was found in 9 species, but its low prevalence suggests accidental infection in all species. Although the larval nematode presented low host specificity, it exhibited some host preference.

  3. Contamination of Omnivorous Freshwater Fish Species and Sediments by Chlorinated Hydrocarbons in Poland

    Directory of Open Access Journals (Sweden)

    Niewiadowska Alicja

    2014-10-01

    Full Text Available The occurrence and concentrations of organochlorine pesticides and polychlorinated biphenyls (PCBs were determined in 158 muscle samples of bream (Abramis brama and roach (Rutilus rutilus, and 84 samples of sediments collected from 10 river and lake sampling sites in 2011 and 2012. The concentrations of DDTs (p,p’-DDT, o,p’-DDT, p,p’-DDE, and p,p’-DDD, HCH isomers (a-, ß-, and y-HCH, HCB, and PCBs (six indicator PCB congeners 28, 52, 101, 138, 153 and 180 were determined using the capillary gas chromatography. The mean concentrations of DDTs in bream and roach were in the range of 11.2-654 and 4.5-121 ug/kg wet weight respectively, and PCBs were in the range of 1.3-75.9 and 1.1-112 ug/kg wet weight, respectively. Mean concentrations of DDTs and PCBs in sediments were 0.5-270 ug/kg dry weight and ⋋0.1-2.2 ug/kg dry weight respectively. The study showed clear spatial differences in the levels of organochlorine pesticides and PCBs in fish and sediments from different aquatic ecosystems. The highest levels of contaminants were detected in fish and sediments from the Vistula River in vicinity of Cracow. The possible risk to the fish meat consumers and ecological risk were evaluated.

  4. Radioactivity of surface water and freshwater fish in Finland in 1991-1994

    Energy Technology Data Exchange (ETDEWEB)

    Saxen, R.; Koskelainen, U.

    1996-01-01

    Changes over time in the activity concentrations of {sup 3}H, {sup 90}Sr and gamma-emitting radionuclides in lake and river water were studied. The uneven distribution of Chernobyl deposition is still seen in areal concentrations. {sup 137}CS in surface water has decreased significantly: In the drainage area where the activity concentrations were highest after the Chernobyl accident the concentrations in October 1992 were only about 1-4 % of the maximum values in May 1986. The decrease in the activity concentrations of {sup 90}Sr was much slighter, and 30-90 % of the values for {sup 90}Sr in May 1986 still remained in various drainage areas in October 1992. Amounts of {sup 137}Cs and {sup 90}Sr transported by the five largest rivers to the Baltic Sea after the Chernobyl accident were estimated to be 38 and 5.5 TBq, respectively, during 1986-1994. Areal and temporal changes in the activity concentrations of {sup 137}Cs in fish were also studied in 1991-1994. In all, about 1800 fish samples from southern and central Finland were analysed gammaspectrometrically during this period. Nineteen different fish species were included in the study. The highest activity concentrations of {sup 137}Cs were detected in small oligotrophic lakes in the area of highest deposition. The average activity concentrations, weighted by catches, in each of the eight statistical fisheries and in the whole country were calculated. (25 refs., 19 figs., 8 tabs.).

  5. MICRONUCLEI PROFILE: AN INDEX OF CHROMOSOMAL ABERRATIONS IN FRESHWATER FISHES (SYNODONTIS CLARIAS AND TILAPIA NILOTICA

    Directory of Open Access Journals (Sweden)

    J.C. OKONKWO

    2011-01-01

    Full Text Available Incidence of chromosomal aberrations in Synodontis clarias and Tilapia nilotica (Linnaeus 1757 were measured using the conventional micronucleus assay in fish erythrocytes. The species showed varying degree of micronuclei frequencies in their respective genomes of sampled gill and kidney blood. Cytological examinations showed bi-nucleated cells, deformed nuclei including the main aberrations, micronucleus formations in various genomes of the fish from different locations considered in this study. Comparison of the micronucleus rates in peripheral and kidney blood of the two species revealed no statistical difference (P> 0.05. On species occurrence of the measured chromosomal aberrations, averages of micronucleus frequencies recorded in Synodontis clarias showed visible variation and to be 2.2 folds higher than the values obtained in the corresponding Tilapia sp. but there was no statistical difference (P>0.01 among the two breeds. The work recommends that micronuclei tests in fish erythrocytes be carried out at various times, thus making it possible to follow-up the changing micronuclei frequencies and concludes that gills and kidney erythrocytes can be used in studies concerning chromosomal aberrations since the sampling of the peripheral blood is appropriate as it allows collecting several samples from the same individuals, without having to sacrifice it.

  6. FISH in micronucleus test demonstrates aneugenic action of rotenone in a common freshwater fish species, Nile tilapia (Oreochromis niloticus).

    Science.gov (United States)

    Melo, Karina M; Grisolia, Cesar K; Pieczarka, Julio C; de Souza, Ludmilla R; Filho, José de Souza; Nagamachi, Cleusa Y

    2014-05-01

    Aneuploidies are numerical genetic alterations that lead to changes in the normal number of chromosomes due to abnormal segregation during cell division. This type of alteration can occur spontaneously or as a result of exposure to mutagenic agents. The presence of these agents in the environment has increased concern about potential damage to human health. Rotenone, derived from plants of the genera Derris and Lonchocarpus, is a product that is used all over the world as a pesticide and piscicide. Before establishing its potential and efficiency for these purposes, it is essential to know more about the possible adverse effects that it may cause. The current work aimed to evaluate the mutagenic potential of rotenone using fish from the species Oreochromis niloticus, as well as to help in understanding its action mechanism. Our results showed the mutagenic potential of rotenone evidenced by increased formation of micronuclei and nuclear buds at low doses of exposure. The use of fluorescence in situ hybridisation technique made it possible to measure the aneugenic potential of the substance, probably due to its impairment of mitotic spindle formation.

  7. Climate change risks, extinction debt, and conservation implications for a threatened freshwater fish: Carmine shiner (Notropis percobromus).

    Science.gov (United States)

    Pandit, Shubha N; Maitland, Bryan M; Pandit, Laxmi K; Poesch, Mark S; Enders, Eva C

    2017-11-15

    Climate change is affecting many freshwater species, particularly fishes. Predictions of future climate change suggest large and deleterious effects on species with narrow dispersal abilities due to limited hydrological connectivity. In turn, this creates the potential for population isolation in thermally unsuitable habitats, leading to physiological stress, species declines or possible extirpation. The current extent of many freshwater fish species' spatio-temporal distribution patterns and their sensitivity to thermal impacts from climate change - critical information for conservation planning - are often unknown. Carmine shiner (Notropis percobromus) is an ecologically important species listed as threatened or imperilled nationally (Canada) and regionally (South Dakota, United States) due to its restricted range and sensitivity to water quality and temperature. This research aimed to determine the current distribution and spatio-temporal variability in projected suitable habitat for Carmine shiner using niche-based modeling approaches (MaxEnt, BIOCLIM, and DOMAIN models). Statistically downscaled, bias-corrected Global Circulation Models (GCMs) data was used to model the distribution of Carmine shiner in central North America for the period of 2041-2060 (2050s). Maximum mean July temperature and temperature variability were the main factors in determining Carmine shiner distribution. Patterns of projected habitat change by the 2050s suggest the spatial extent of the current distribution of Carmine shiner would shift north, with >50% of the current distribution changing with future projections based on two Representative Concentrations Pathways for CO2 emissions. Whereas the southern extent of the distribution would become unsuitable for Carmine shiner, suitable habitats are predicted to become available further north, if accessible. Importantly, the majority of habitat gains for Carmine shiner would be in areas currently inaccessible due to dispersal

  8. Agricultural sources of contaminants of emerging concern and adverse health effects on freshwater fish

    Science.gov (United States)

    Tillitt, Donald E.; Buxton, Herbert T.

    2011-01-01

    Agricultural contaminants of emerging concern (CECs) are generally thought of as certain classes of chemicals associated with animal feeding and production facilities. Veterinary pharmaceuticals used in animal food production systems represent one of the largest groups of CECs. In our review, we discuss the extensive increase in use of antibiotics in animal feeding operations (AFOs) around the world. AFOs are a major consumer of antibiotics and other veterinary pharmaceuticals and over the past decade there has been growing information on the occurrence, release, and fate of CECs from animal food production operations, including the application of pharmaceutical-containing manure to agricultural fields and releases from waste lagoons. Concentrations of CECs in surface and ground water in proximity to AFOs correspond to their presence in the AFO wastes. In many cases, the environmental concentrations of agriculturally-derived CECs are below toxicity thresholds. Hormones and hormone replacement compounds are a notable exception, where chemical concentrations near AFOs can exceed concentrations known to cause adverse effects on endocrine-related functions in fish. In addition, some agricultural pesticides, once thought to be safe to non-target organisms, have demonstrated endocrine-related effects that may pose threats to fish populations in agricultural regions. That is, we have pesticides with emerging concerns, thus, the concern is emerging and not necessarily the chemical. In this light, one must consider certain agricultural pesticides to be included in the list of CECs. Even though agricultural pesticides are routinely evaluated in regulatory testing schemes which have been used for decades, the potential hazards of some pesticides have only recently been emerging. Emerging concerns of pesticides in fish include interference with hormone signaling pathways; additive (or more than additive) effects from pesticide mixtures; and adverse population-level effects at

  9. A remarkable sand-dwelling fish assemblage from central Amazonia, with comments on the evolution of psammophily in South American freshwater fishes

    Directory of Open Access Journals (Sweden)

    Jansen Zuanon

    paedomorphic traits. We consider that the little variable specific composition of fish sand-dwelling assemblages and the wide (although patchy geographical distribution of their species in the Amazon are due to the widespread occurrence and low complexity of this specialised habitat. The pre-existence of benthic habits, small size, and the broad distribution of rivers with sandy beds, mainly in the Amazon and Orinoco basins, possibly played a determinant role in the origin and diversification of psammophilous assemblages among freshwater fishes in South America.

  10. Bilogy, life cycle and phylogeny of malacosporeans in fish and bryozoans

    OpenAIRE

    HRABCOVÁ, Martina

    2015-01-01

    Malacosporeans (Myxozoa) comprising only three nominal species, cycle between vertebrate (fish) and invertebrate (bryozoans) host in freshwater aquatic ecosystems. This thesis is focused on in vitro cultivation of bryozoans, using algal cultures in order to investigate malacosporean life cycles via transmission experiments. Moreover, the biodiversity, prevalence, distribution, habitat/host preference and phylogenetic trends of malacosporeans in freshwater fish hosts are scrutinized using ligh...

  11. Heavy metal distribution in tissues of six fish species included in human diet, inhabiting freshwaters of the Nature Park "Hutovo Blato" (Bosnia and Herzegovina).

    Science.gov (United States)

    Has-Schön, Elizabeta; Bogut, Ivan; Rajković, Valentina; Bogut, Stjepan; Cacić, Milan; Horvatić, Janja

    2008-01-01

    The aim of the study was to quantify heavy metal (mercury, lead, cadmium, and arsenic) concentration in tissues (muscles, liver, kidney, gills, and gonads) of six fish species (carp: Cyprinus carpio, tench: Tinca tinca, pumpkinseed: Lepomis gibosus, prussian carp: Carassius auratus gibelio, hasselquist: Salmo dentex, eel: Anguilla anguilla) from the freshwaters of the Nature Park Hutovo Blato, Bosnia and Herzegovina, and determine whether they are potentially harmful for human health if included in the diet. Fish were angled from the Svitava Lake in the second part of August of the year 2003, and fish tissues were stored at -18 degrees C until analysis. Heavy metal concentration was determined by atomic absorption spectrophotometry in the Veterinary Institute Brno, Czech Republic, and expressed as mg.kg(-1) of wet tissue. Concentration of mercury, lead, and arsenic in most tissues of all analyzed fish types is lower than the maximal allowed concentration (MAC) in most countries. Cadmium concentration is also low in muscles and gonads, but kidney, liver, and gill concentrations exceed MAC value in most countries. Hasselquist, an endemic type for that region, differs from other fish types in the fact that it has very low cadmium concentration in liver and kidney, but the highest concentration of arsenic in most tissues, especially muscles. In muscles and gonads of all fish types analyzed, Pb is present in higher concentration than Cd, whereas in liver, gills, and particularly kidney, the situation is opposite, suggesting diverse metabolic pathways and unequal bioaccumulation of these two metals in different fish tissues. Although the region of the Nature Park Hutovo Blato in Bosnia and Herzegovina is not an agricultural territory, the intensive agricultural activities in the neighboring regions already result in high cadmium concentration in inner organs of fish species analyzed. Therefore, fish types in the freshwaters of the Park may be included in the human diet

  12. Exploring the relationship between convenience and fish consumption: a cross-cultural study.

    Science.gov (United States)

    Olsen, Svein Ottar; Scholderer, Joachim; Brunsø, Karen; Verbeke, Wim

    2007-07-01

    The purpose of the present study is to explore cultural differences in the meaning of convenience and the relationships between convenience, attitudes and fish consumption in five European countries. The results suggest that the meaning of meal convenience is not culture specific, whilst the absolute levels of convenience orientation and the perceived inconvenience of fish differ between cultures. Convenience orientation was highest in Poland, followed by Spain, and was lowest in the Netherlands. The relationships between convenience orientation and attitudes towards fish, and convenience orientation and fish consumption, were insignificant in most countries. However, convenience orientation was positively related to the perceived inconvenience of fish. Perceived inconvenience of fish was negatively related to both attitudes towards fish and to fish consumption. Together, these results confirm some earlier findings that fish is generally perceived as a relatively inconvenient type of food. This study suggests that convenience orientation can be crucial to understanding food choice or behaviour only when critical mediating constructs are explored.

  13. The freshwater fish fauna history between Rhine and Ebro: general considerations and comments from on-going developments in fish taxonomy

    Directory of Open Access Journals (Sweden)

    Henri Persat

    2015-11-01

    Full Text Available Because of its position between Central Europe and the Iberian Peninsula, French territory is an obligatory expansion route for their respective continental faunas, freshwater ones included. The twin Rhine-Rhone river drainage basins make an obvious link between both Central and Northern Europe and the South-Western Europe. But how fish might have dispersed along the series of rivers of the Western side of France (Seine, Loire, Charente, Garonne and Adour is less evident, as the ice ages have had a large impact on the pre-existing faunas, before human intervention blurred phylogeographic patterns, either indirectly with trans-watershed canals, or directly with purposeful translocations. What might have survived during the last glacial times is a key question in terms of management and conservation of the local fish biodiversity. Unfortunately, this diversity had been neglected or underappreciated in France until modern phylogeographic and population genetic research provided new and enlightening insights into interspecific and intraspecific variation. Thus, after one century of scientific starvation, French territory recently "gained" a series of novel species in various genera, such as Gobio, Cottus, Squalius, Leuciscus, Phoxinus, and Esox, waiting for more on going "acquisitions" in a near future. These novelties trace a quite different biogeographic landscape of what was formerly supposed to be uniform. Each major river basin retains traces of a more or less recent evolutionary history to put back into the succession of hydrographic and climatic events since the first major invasion, the entrance of cyprinids in Europe during the Oligocene era initiated by the coalescence of what was formerly only an archipelago. The timing of dispersion and on-site speciation will be discussed from the examples provided by the presently investigated genera according to evidence or hypotheses on river connections, sea-level fluctuations and climatic events.

  14. Freshwater fish's spatial patterns in isolated water springs in North-eastern Mexico.

    Science.gov (United States)

    Palacio-Núñez, Jorge; Verdú, José R; Numa, Catherine; Jiménez-García, Daniel; Olmos Oropeza, Genaro; Galante, Eduardo

    2010-03-01

    The Media Luna lake-spring was selected as representative of all thermal or no thermal springs in the zone of Valley of Rioverde, a semi-arid vegetation in the North-eastern of Mexico. This system is inhabited by 11 fish species, of which six are native. Four of the native species are endemic to the region and threatened due to touristic pressure and to the introduction of exotic species. The objectives were to determine the characteristics that influence the spatial distribution of the fish species, to analyze their spatial distribution patterns, and to describe the relationships between the different species. The general aim was to establish some basis for the conservation of these fish communities and their habitat. Several sessions were initiated in 1992 through direct observation. Later, between 1998 and 1999 five systematically seasonal sampling sessions were conducted (54 subaquatic transects/session). Finally, the data was updated by sampling in summer 2002 and winter 2006. Through the analysis was performed only for endemics of the region, like Ataeniobius toweri Meek, Cualac tessellatus Miller, Cichlasoma bartoni Bean and C. labridens Pellegrin, in at least one life stage, showed correlation with habitat variables or with other species. For these species, patterns of spatial aggregation and association with other species were observed. These results show a certain degree of specialization of endemic species to some microhabitat characteristics, as well as a significant interaction with other native species which they coexist. In addition, some significant relations between endemic and alien species suggest an antagonist relation. Management actions focused in the touristic use of the spring represent the main threat for these species, followed by an adequate management of exotic species. This study provides basis for future responsible management of these wetlands, where tourism and conservation can be combined.

  15. Behavioral and biochemical responses in freshwater fish Carassius auratus exposed to sertraline.

    Science.gov (United States)

    Xie, Zhengxin; Lu, Guanghua; Li, Sheng; Nie, Yang; Ma, Binni; Liu, Jianchao

    2015-09-01

    Sertraline is one of the most commonly prescribed selective serotonin reuptake inhibitors and is frequently detected in the aquatic environment. However, knowledge regarding relationships among molecular or biochemical endpoints involved in modes of action (MOAs) of sertraline and ecologically important behavioral responses of fish is insufficient. The present study aimed to investigate the bioconcentration and possible adverse outcomes pathways (AOPs) in crucian carp (Carassius auratus) exposed to various concentrations of sertraline (4.36, 21.3 and 116 μg L(-1)) for 7 d. Bioconcentration factor values were in the range of 19.5-626 in liver, 6.94-285 in brain, 4.01-146 in gill and 0.625-43.1 in muscle during the entire period of exposure. Liver superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) and glutathione-S-transferase (GST) activities and brain acetylcholinesterase (AChE) activity were selected as biochemical endpoints associated with MOAs. Swimming activity, shoaling, feeding rate and food consumption were determined to assess behavioral responses. Fish plasma levels of sertraline exceeding human therapeutic doses were also predicted from external exposure concentrations. Significant enhancements in CAT, GPx, AChE and swimming activities and decreases in shoaling tendency, feeding rate and food consumption were observed when fish plasma levels exceeded human therapeutic thresholds. Shoaling, feeding rate and food consumption were correlated with the activities of SOD, CAT and GST. A significant positive correlation between swimming activity and AChE activity was also observed. As such, our study provides important AOPs linking biochemical responses with ultimate ecologically relevant behavioral endpoints.

  16. Paternal identity impacts embryonic development for two species of freshwater fish

    DEFF Research Database (Denmark)

    Siddique, Mohammad Abdul Momin; Linhart, Otomar; Krejszeff, Sławomir;

    2017-01-01

    Paternal, compared to maternal, contributions were believed to have only a limited influence on embryonic development and larval fitness traits in fishes. Therefore, the perspective of male influence on early life history traits has come under scrutiny. This study was conducted to determine...... effects (1.3%) in Northern pike. Together, these results indicate that male effects are of major importance during embryonic development for these species. Furthermore, this study demonstrates that genetic compatibility between sires and dams plays an important role and needs to be taken...

  17. Toxicity studies of butachlor to the freshwater fish Channa punctata (Bloch).

    Science.gov (United States)

    Tilak, K S; Veeraiah, K; Bhaskara Thathaji, P; Butchiram, M S

    2007-04-01

    The toxicity studies were conducted on the fish Channa punctata (Bloch) by employing static and continuous flow through systems, for the toxicant butachlor (technical grade+) and its commercial formulation+ (machete 50% EC). The LC50 values are 297.89 ppb and 247.46 ppb for 24 hr and 48 hr in static for technical and 636.45 and 546.09 for machete. In continuous flow through the values are 270.05, 233.52 to the technical and 567.85 and 481.49 respectively for machete. The tissues show qualitative accumulation and were quantitatively analysed by gas liquid chromatography (GLC).

  18. Invasion risks posed by ornamental freshwater fish trade to southeastern Brazilian rivers

    Directory of Open Access Journals (Sweden)

    Andre Lincoln Barroso de Magalhaes

    Full Text Available A model was developed to assess the risk of invasion of ornamental non-native fishes to six rivers in the state of Minas Gerais, southeastern Brazil, with focus on species popularity. Thirty-nine aquarium shops, in six cities, were visited monthly from January to December 2007. In each city, fish species were identified, and their biology and invasion history information was obtained from the literature. We calculated the annual frequency of occurrence and average number of specimens monthly available in stores. Quarterly water temperature and dissolved oxygen data from 1997 to 2007 were obtained for the Velhas, Muriaé, Uberabinha, Sapucaí-Mirim, Doce and Todos os Santos Rivers from public databases. The invasion risk of each species was assessed through a model comprising nine parameters grouped in four variables: (i Invasiveness (thermal and dissolved oxygen ranges, diet, parental care or fecundity, (ii History of invasions (establishment, (iii Propagule pressure (commercial success, comprising annual frequency of occurrence and number of specimens available monthly at stores, and (iv Invasibility (water temperature and dissolved oxygen in the target river compatible with the species ranges. Of the 345 ornamental fish species for sale, 332 are non-native to either Minas Gerais (n = 151 or Brazil (n = 194. Based on the proposed cutting values, in particular the compatibility between species and recipient thermal ranges, five ornamental non-native species (Cyprinus rubrofuscus, Carassius auratus, Xiphophorus hellerii, Poecilia reticulata, and P. latipinna can potentially invade the Velhas and Muriaé Rivers, four species (Cyprinus rubrofuscus, Carassius auratus, X. helleri, and P. reticulata the Uberabinha River, four species (Cyprinus rubrofuscus, Carassius auratus, X. maculatus, and P. reticulata the Sapucaí-Mirim River, three species (Carassius auratus, X. hellerii, and P. reticulata the Doce River, and three species (Cyprinus rubrofuscus

  19. Rhipidocotyle gibsoni n. sp. from a Brazilian Freshwater Fish and Rhipidocotyle froesi n.sp. for r. baculum (linton, 1905 of Eckmann (1932 (Bucephalidae; Digenea

    Directory of Open Access Journals (Sweden)

    Anna Kohn

    1994-12-01

    Full Text Available Rhipidocotyle gibsoni n.sp. is described from Acestrorhynchus lacustris from Paraná River, brazil. It is most closely related to r. froesi n. sp. and to R. eckmanni in the shape of the cephalic hood, differing in the extent of the uterus, in the position of the vitelline follicles and in that the host is a freshwater fish. Rhipidocotyle froesi n. sp. is proposed for the marine specimens described by Eckmann (1932 as R. baculum (Linton, 1905.

  20. Culturing and environmental DNA sequencing uncover hidden kinetoplastid biodiversity and a major marine clade within ancestrally freshwater Neobodo designis.

    Science.gov (United States)

    von der Heyden, Sophie; Cavalier-Smith, Thomas

    2005-11-01

    Bodonid flagellates (class Kinetoplastea) are abundant, free-living protozoa in freshwater, soil and marine habitats, with undersampled global biodiversity. To investigate overall bodonid diversity, kinetoplastid-specific PCR primers were used to amplify and sequence 18S rRNA genes from DNA extracted from 16 diverse environmental samples; of 39 different kinetoplastid sequences, 35 belong to the subclass Metakinetoplastina, where most group with the genus Neobodo or the species Bodo saltans, whilst four group with the subclass Prokinetoplastina (Ichthyobodo). To study divergence between freshwater and marine members of the genus Neobodo, 26 new Neobodo designis strains were cultured and their 18S rRNA genes were sequenced. It is shown that the morphospecies N. designis is a remarkably ancient species complex with a major marine clade nested among older freshwater clades, suggesting that these lineages were constrained physiologically from moving between these environments for most of their long history. Other major bodonid clades show less-deep separation between marine and freshwater strains, but have extensive genetic diversity within all lineages and an apparently biogeographically distinct distribution of B. saltans subclades. Clade-specific 18S rRNA gene primers were used for two N. designis subclades to test their global distribution and genetic diversity. The non-overlap between environmental DNA sequences and those from cultures suggests that there are hundreds, possibly thousands, of different rRNA gene sequences of free-living bodonids globally.

  1. Ecotoxicological effects of carbofuran and oxidised multiwalled carbon nanotubes on the freshwater fish Nile tilapia: nanotubes enhance pesticide ecotoxicity.

    Science.gov (United States)

    Campos-Garcia, Janaína; Martinez, Diego Stéfani T; Alves, Oswaldo L; Leonardo, Antônio Fernando Gervásio; Barbieri, Edison

    2015-01-01

    The interactions of carbon nanotubes with pesticides, such as carbofuran, classical contaminants (e.g., pesticides, polyaromatic hydrocarbons, heavy metals, and dyes) and emerging contaminants, including endocrine disruptors, are critical components of the environmental risks of this important class of carbon-based nanomaterials. In this work, we studied the modulation of acute carbofuran toxicity to the freshwater fish Nile tilapia (Oreochromis niloticus) by nitric acid treated multiwalled carbon nanotubes, termed HNO3-MWCNT. Nitric acid oxidation is a common chemical method employed for the purification, functionalisation and aqueous dispersion of carbon nanotubes. HNO3-MWCNT were not toxic to Nile tilapia at concentrations ranging from 0.1 to 3.0 mg/L for exposure times of up to 96 h. After 24, 48, 72 and 96 h, the LC50 values of carbofuran were 4.0, 3.2, 3.0 and 2.4 mg/mL, respectively. To evaluate the influence of carbofuran-nanotube interactions on ecotoxicity, we exposed the Nile tilapia to different concentrations of carbofuran mixed together with a non-toxic concentration of HNO3-MWCNT (1.0 mg/L). After 24, 48, 72, and 96 h of exposure, the LC50 values of carbofuran plus nanotubes were 3.7, 1.6, 0.7 and 0.5 mg/L, respectively. These results demonstrate that HNO3-MWCNT potentiate the acute toxicity of carbofuran, leading to a more than five-fold increase in the LC50 values. Furthermore, the exposure of Nile tilapia to carbofuran plus nanotubes led to decreases in both oxygen consumption and swimming capacity compared to the control. These findings indicate that carbon nanotubes could act as pesticide carriers affecting fish survival, metabolism and behaviour.

  2. Toxicity assessment on haemotology, biochemical and histopathological alterations of silver nanoparticles-exposed freshwater fish Labeo rohita

    Science.gov (United States)

    Rajkumar, K. S.; Kanipandian, N.; Thirumurugan, R.

    2016-01-01

    The increasing use of nano based-products induces the potential hazards from their manufacture, transportation, waste disposal and management processes. In this report, we emphasized the acute toxicity of silver nanoparticles (AgNPs) using freshwater fish Labeo rohita as an aquatic animal model. The AgNPs were synthesized using chemical reduction method and the formation of AgNPs was monitored by UV-Visible spectroscopy analysis. The functional groups, crystaline nature and morphological characterizations were carried out by fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and high resolution transmission electron microscopy (HRTEM) analysis. UV-Vis range was observed at 420 nm and XRD pattern showed that the particles are crystalline nature. HRTEM analysis revealed that the morphology of particles was spherical and size ranges between 50 and 100 nm. This investigation was extended to determine the potential acute toxicity, L. rohita was treated orally with the lethal concentration (LC50) of AgNPs. The antioxidative responses were studied in the three major tissues such as gill, liver and muscle of L. rohita. The results of this investigation showed that increasing the concentration of AgNPs led to bioaccumulation of AgNPs in the major tissues. The haematological parameters showed significant alterations in the treated fish. The histological changes caused by chemically synthesized AgNPs demonstrated the damages in the tissues, primary lamella and blood vessels of L. rohita. The histological study also displayed the formation of vacuolation in liver and muscle when compared with untreated tissues (control) of L. rohita.

  3. Provenancing fish in freshwaters of the Alpine Foreland using Sr/Ca and 87Sr/86Sr ratios in otoliths and otolith shape parameters

    Directory of Open Access Journals (Sweden)

    Johannes Oehm

    2015-12-01

    Although the studied freshwaters were located only in a 50 km range around lake Chiemsee on a similar geological background, differences in water chemistry, fish otolith chemistry and shape were identified. Species specific differences in reflection of the Sr/Ca ratio of a specific water body were detected. Microchemical and morphological otoliths analyses complemented each other and allowed assigning fish to specific groups of waters of origin. This information provides an important basis for the further application of otolith chemistry and shape analysis in the Alpine foreland for a diverse range of ecological questions.

  4. Study of the microbial flora of freshwater and seawater fish filets in different packaging conditions by metagenomic analysis targeted on the 16S ribosomal DNA

    OpenAIRE

    Delhalle, Laurent; Taminiau, Bernard; Nezer, Carine; Daube, Georges

    2012-01-01

    Metagenomics has appeared as a powerful tool to study bacterial composition of various environmental samples. This work describes the application of this technique to study the bacterial population of two fresh fish filets. The two fish species are from freshwater (pangasius) and seawater (haddock), respectively. Samples where directly analyzed the day of receipt. Others samples were analyzed at the end their shelf life after storage at 4°C (1/3 of their shelf life) and 8°C (2/3 of their shel...

  5. Notes on the occurrence of Trypanosoma sp. (Kinetoplastida: Trypanosomatidae in freshwater fishes from South Africa

    Directory of Open Access Journals (Sweden)

    Maryke L. Ferreira

    2013-03-01

    Full Text Available A total of 257 fishes from four families, Clariidae, Cichlidae, Cyprinidae and Schilbeidae were collected from three localities: the Sand River Dam, Swaziland; the Nylsvlei Nature Reserve, South Africa and the Vaal Dam and Vaal River Barrage, South Africa. Only fishes (n= 154 from Clariidae and Cichlidae were found to be infected with trypanosomes. A total of 221 Clarias gariepinus (Burchell 1822 were collected from the Vaal Dam and Vaal Barrage area, South Africa. Of these, 74%(89/121 were infected with trypanosomes from the Vaal Dam and 63%(63/100 from the Vaal River Barrage, with no seasonal infection pattern. A prevalence of 25%(1/4 was found in C. gariepinus from the Sand River Dam, Swaziland, and a 50% (1/2 prevalence was found in Tilapia sparrmanii from the Nylsvlei Nature Reserve, South Africa. Standard measurements conformed closely to the morphometric and morphological descriptions of Trypanosoma mukasai. This article provides new locality records for T. mukasai from the Vaal Dam, Vaal River Barrage and Nylsvlei Nature Reserve (South Africa and the Sand River Dam (Swaziland. Tilapia sparrmanii collected in the Sand River Dam in Swaziland is also noted as a new host record.

  6. Observations on cucullanid nematodes from freshwater fishes in Mexico, including Dichelyne mexicanus sp. n.

    Science.gov (United States)

    Caspeta-Mandujano, J M; Moravec, F; Salgado-Maldonado, G

    1999-01-01

    A new cucullanid nematode, Dichelyne mexicanus sp. n., is described from the intestine of three species of fishes, Agonostomus monticola (Bancroft) (Mugilidae, Perciformes) (type host), Ictalurus balsanus (Jordan et Snyder) (Ictaluridae, Siluriformes) and Cichlasoma beani (Jordan) (Cichlidae, Perciformes), from three rivers (La Maquina River, Veracruz; Chontalcoatlán River, Guerrero and Santiago River, Nayarit) in central Mexico. This species is characterised by the absence of a ventral sucker in the male (subgenus Dichelyne) and it differs from its congeners mainly in possessing very unequal and dissimilar spicules (left 0.465-0.768 mm and right 293-548 mm long), an asymmetrical gubernaculum, and two intestinal caeca. Another cucullanid nematode, Cucullanus caballeroi Petter, 1977, is reported from Dormitator maculatus (Bloch) (Eleotridae, Perciformes) from the La Palma and La Maquina Rivers and Balzapote stream, Veracruz, being briefly described and illustrated; this represents a new host record. Findings of D. mexicanus and C. caballeroi represent a new record of cucullanid nematodes from fishes in Mexican fresh waters.

  7. Helminth parasites of freshwater fishes from Cuatro Ciénegas, Coahuila, in the Chihuahuan Desert of Mexico: inventory and biogeographical implications.

    Science.gov (United States)

    Aguilar-Aguilar, Rogelio; Martínez-Aquino, Andrés; Espinosa-Pérez, Héctor; Pérez-Ponce de León, Gerardo

    2014-06-01

    As part of an ongoing inventory of the helminth parasites of freshwater fishes in Mexico, 570 individual fish were collected between Apr 2008 and Oct 2011 in 26 localities along the Cuatro Ciénegas region in Coahuila State, northern Mexico. Seventeen species of hosts, mostly corresponding to Nearctic freshwater elements, were studied. A total of 8324 individual worms were collected during this survey, representing 25 species of helminths, of which 9 were digeneans, 3 monogeneans, 3 acanthocephalans, 9 nematodes and 1 cestode. Most of the records in this checklist represent new host or locality records. The information provided in this checklist may be helpful for our understanding of the biodiversity and historical biogeography of this host-parasite system, because in the Cuatro Ciénegas region occur a Nearctic freshwater fish fauna, along with Neotropical and endemic elements, and from a biogeographical point of view, this may represent a transitional area. © 2013 International Society of Zoological Sciences, Institute of Zoology/Chinese Academy of Sciences and Wiley Publishing Asia Pty Ltd.

  8. Histo-morphology of the alimentary canal in two freshwater snakehead fish Channa punctata and Channa striata

    Directory of Open Access Journals (Sweden)

    Mita Borman

    2015-12-01

    Full Text Available The histo-morphological study of the alimentary canal of two carnivore freshwater snakehead fish Channa punctata and C. striata was carried out from October 2013 to July 2014. It revealed that three major parts like oesophagus, stomach and intestine composed of short thick-walled body. The oesophagus begins with buccopharynx. Structure and arrangement of both villiform and canine teeth on jaws in C. striata are more extendable and stronger than C. punctata and thereby made the former one more successful predator. The availability and arrangement pattern of mucous pits and taste bud pores in oesophagus are also prominent in C. striata. The TS of stomach of both the species has broad GM devoid of goblet mucous cells, but surface layer CC and basal layer GG open through gastric pits. The length of intestine (16.0 cm and intestinal pyloric caeca (5.5 cm in C. striata are larger than C. punctata (7.0 cm and 1.5 cm, respectively. However, the TS of intestinal Sr. 0.05 mm; MM. 0.8 mm; Mu 0.5 mm suggest in favour of carnivore habit of both the species.

  9. Hepatoprotective activity of Tribulus terrestris extract against acetaminophen-induced toxicity in a freshwater fish (Oreochromis mossambicus).

    Science.gov (United States)

    Kavitha, P; Ramesh, R; Bupesh, G; Stalin, A; Subramanian, P

    2011-12-01

    The potential protective role of Tribulus terrestris in acetaminophen-induced hepatotoxicity in Oreochromis mossambicus was investigated. The effect of oral exposure of acetaminophen (500 mg/kg) in O. mossambicus at 24-h duration was evaluated. The plant extract (250 mg/kg) showed a remarkable hepatoprotective activity against acetaminophen-induced hepatotoxicity. It was judged from the tissue-damaging level and antioxidant levels in liver, gill, muscle and kidney tissues. Further acetaminophen impact induced a significant rise in the tissue-damaging level, and the antioxidant level was discernible from the enzyme activity modulations such as glutamate oxaloacetic transaminase, glutamate pyruvic transaminase, alkaline phosphatase, acid phosphatase, glucose-6-phosphate dehydrogenase, lactate dehydrogenase, superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase, glutathione S-transferase, lipid peroxidase and reduced glutathione. The levels of all these enzymes have significantly (p terrestris extract (250 kg/mg). Histopathological changes of liver, gill and muscle samples were compared with respective controls. The results of the present study specify the hepatoprotective and antioxidant properties of T. terrestris against acetaminophen-induced toxicity in freshwater fish, O. mossambicus.

  10. Unraveling the sequence information in COI barcode to achieve higher taxon assignment based on Indian freshwater fishes.

    Science.gov (United States)

    Chakraborty, Mohua; Ghosh, Sankar Kumar

    2015-04-01

    Efficacy of cytochrome c oxidase subunit I (COI) DNA barcode in higher taxon assignment is still under debate in spite of several attempts, using the conventional DNA barcoding methods, to assign higher taxa. Here we try to understand whether nucleotide and amino acid sequence in COI gene carry sufficient information to assign species to their higher taxonomic rank, using 160 species of Indian freshwater fishes. Our results reveal that with increase in the taxonomic rank, sequence conservation decreases for both nucleotides and amino acids. Order level exhibits lowest conservation with 50% of the nucleotides and amino acids being conserved. Among the variable sites, 30-50% were found to carry high information content within an order, while it was 70-80% within a family and 80-99% within a genus. High information content shows sites with almost conserved sequence but varying at one or two locations, which can be due to variations at species or population level. Thus, the potential of COI gene in higher taxon assignment is revealed with validation of ample inherent signals latent in the gene.

  11. Factors influencing tropical island freshwater fishes:Species, status, and management implications in puerto rico [Factores que influencian a los peces tropicales de agua dulce: Especies, estado actual e implicaciones para el manejo en Puerto Rico

    Science.gov (United States)

    Wesley, Neal J.; Lilyestrom, C.G.; Kwak, T.J.

    2009-01-01

    Anthropogenic effects including river regulation, watershed development, contamination, and fish introductions have substantially affected the majority of freshwater habitats in Europe and North America. This pattern of resource development and degradation is widespread in the tropics, and often little is known about the resources before they are lost. This article describes the freshwater resources of Puerto Rico and identifies factors that threaten conservation of native fishes. The fishes found in freshwater habitats of Puerto Rico represent a moderately diverse assemblage composed of 14 orders, 29 families, and 82 species. There are fewer than 10 species of native peripherally-freshwater fish that require a link to marine systems. Introductions of nonindigenous species have greatly expanded fish diversity in freshwater systems, and native estuarine and marine species (18 families) also commonly enter lowland rivers and brackish lagoons. Environmental alterations, including land use and development, stream channelization, pollution, and the impoundment of rivers, combined with nonnative species introductions threaten the health and sustainability of aquatic resources in Puerto Rico. Six principal areas for attention that are important influences on the current and future status of the freshwater fish resources of Puerto Rico are identified and discussed.

  12. Trypanosomiasis in hybrid catfish (Clarias macrocephalus x Clarias gariepinus and other freshwater fishes

    Directory of Open Access Journals (Sweden)

    Promkhunthong, W.

    2005-02-01

    Full Text Available The infestation of Trypanosoma sp. (Kinetoplastida in the hybrid catfish and some fresh water fish was studied showing such parasitic infestation was specific only in catfish. The virulence as determined by LD50 for 5 days was 2.28x1010 cell in a fish sample. The parasitic infestation caused hematological changes by the reduction of red as well as white blood cells. The reductions were highly significant as compared to the healthy sample (p<0.05 as noted by the red and white blood cell count which dropped from 2.14±0.48x106 to 1.62±0.27x106 cells/ml and from 1.45±3.76x105 to 2.42±0.78x104 cells/ml blood in the infested samples, respectively. Similar trend was noted for hemoglobin and hematocrit which dropped significantly (p<0.05. The hemoglobin in healthy fish is 7.075±0.929g/100g, which dropped to 6.268±0.697g/100g in the samples with infestation. The percentage of hematocrit in healthy sample is 25.275±3.318%, which dropped to 21.722±3.068% in the samples with infestation. The reverse trend was recognized for serum protein andleukocrit which increased in the samples with Trypanosoma sp. infestation. The density gradient centrifugation technique was employed in the isolation of parasites in which 50% Percoll solution in 0.85% final preparation of saline solution was capable of removing Trypanosoma sp. from the blood. The study of antibody levels in serum showed that the infested hybrid catfish could develop the antibody which reached a peak 14 days after the infestation. Trypanosoma sp. was unable to cause histological changes in the tissues of gill, liver, kidney, spleen, stomach and intestine. Minor inflammations were observed, even the cases that large number of parasites were found in the tissues, blood streams and sinuses. Marked reductions were recorded for mature red blood cells while there were the formation of immature red blood and phagocytotic cells at higher rates as compared to the healthy individual.

  13. Hierarchy formation and hormonal profiles in Australoherus facetus, an invasive freshwater fish in Portugal.

    Directory of Open Access Journals (Sweden)

    Flávia Baduy

    2015-11-01

    Full Text Available Australoheros facetus is a highly social neotropical cichlid that is invasive in the Guadiana and Odelouca basins (Southern Portugal. Phenotypic plasticity is believed to be a key component for invasive success. However, its biology remains largely unknown. In this research we aimed to characterize the behaviour and hormone profiles (Testosterone (T, Estradiol (E, 11-keto-testosterone (11KT and Cortisol throughout the formation of stable social groups, a crucial step in the life-history of A. facetus. Fifteen social groups (n=4-6 size matched individuals per group were observed and filmed until stable hierarchies were formed (7 days at different periods of the year. An ethogram was established and a dominance index (DI=wins/ total interactions was used to quantify social dominance. Blood samples were taken from all fish at the beginning and end of the experiment. After the trial period, the animals were sacrificed and the gonads inspected for sex determination. A pair breeding strategy with territorial behaviour was found, and territorial status was attributed to fish that formed a breeding couple and defended an arena. A positive correlation was found between dominance and size for both sexes (length: females R=0.63, males R=0.74; Weight: females R=0.79; males R=0.69; p<0.05. There were no differences between individuals in the initial levels of all hormones, but while T and E showed no evident pattern, final 11KT was higher in territorial males (territorial=2.30ng/mL, non-territorial=1.11ng/mL, p<0.05. Final cortisol were higher in non-territorial males (territorial=96.91ng/mL, non-territorial=163.3ng/mL, p<0.05 and negatively correlated with dominance (R=-0.47, p<0.05. These results suggest that size is the main driver for social dominance and that high social status lowers stress in all fish and increases 11KT secretion in males. Further analysis are in progress to understand the complex reproductive processes and the interspecific

  14. [Diet of the tropical freshwater fish Heterandria bimaculata (Haeckel) and Poecilia sphenops Valenciennes (Cyprinidontiformes: Poeciliidae)].

    Science.gov (United States)

    Trujillo-Jiménez, Patricia; Beto, Héctor Toledo

    2007-06-01

    We analyzed the diet and feeding habits of the fishes Heterandria bimaculata and Poecilia sphenops. Specimens were captured monthly in "Los Carros" damp, Morelos, Mexico (18 degrees 37' N, 98 degrees 43' W). We quantified gut content by the numerical method and by the frequency of occurrence method; and used the MacArthur and Levin's indices for niche overlap. The diet of H. bimaculata was composed by 16 prey categories, mainly dipterans (Culicidae predominated), independently of sex, size and season. The index of niche overlap was high, from 0.74 to 0.99. The diet of P. sphenops consisted of 11 items, detritus being the most consumed, also independently of sex, size and season. The niche overlap index was high (0.99), indicating overlapping for all analyses. There was little diet overlap (0.26) between the two species.

  15. [Citogenetic characterization of the tropical freshwater fish Parachromis managuensis (Pisces: Cichlidae)].

    Science.gov (United States)

    Arias-Rodríguez, Lenin; Páramo-Delgadillo, Salomón; Durán-González, Alicia de la Luz

    2006-03-01

    To describe the cytogenetics of the jaguar cichlid fish Parachromis managuensis, we collected eight males and 13 females in Villahermosa, Tabasco, México. The specimens were processed with standard cytogenetic techniques (slightly modified), and high quality fields of chromosomes in mitosis and meiosis were obtained; 14 of these fields were analyzed by meristics and statistics methods. The specimens presented a diploid modal number of 2n = 48 chromosomes, which is similar to the number reported for others Central American cichlids; five pairs were submetacentric-metacentrics (biarmed) and 19 were subtelocentric-telocentric (uni-armed), giving a fundamental number (NF) of 58. The haploid number was confirmed by counting meiotic fields in metaphase I. There was not evidence of heteromorphism: sexual chromosomes were not identifiable.

  16. Non-native freshwater fishes in the Iberian Southeast: black list and potential impacts

    Directory of Open Access Journals (Sweden)

    Fátima Amat-Trigo

    2015-10-01

    At least, sixteen species had been introduced the Southeast Iberian by the beginning of the 20th century, but the rate of introduction is highly elevated in the last two decades, with the majority of introductions since 2000. Most studies reviewed reported only potential impacts. Failed introductions are poorly documented and existing information is scattered in regional publications, reports and other grey literature. Due to the interbasin water transfers (Tajo-Segura channel, the number of translocated species is high, however, information about these fishes is not regarded by researchers and their potential impacts are neglected. We established a black list with sixteen cited species and nineteen potential invasive species. Additionally, research needs and management priority measures are evaluated.

  17. Assessing the impact of non-native freshwater fishes on native species using relative weight

    Directory of Open Access Journals (Sweden)

    Giannetto D.

    2012-01-01

    Full Text Available The aim of the research was to test relative weight (Wr, a condition index which allows evaluation of fish well-being, as a tool to investigate the impact of the presence of non native species (NNS on the condition of the key native species (NS of the Tiber River basin (Italy: Barbustyberinus Bonaparte, Leuciscus cephalus (Linnaeus, Leuciscus lucumonis Bianco, Rutilus rubilio (Bonaparte and Telestes muticellus (Bonaparte. By means of Canonical Correlation Analysis, data from 130 sampling sites, distributed throughout Tiber River basin, were examined. Wr of NS was related to densities of NNS and to environmental variables. Moreover, the correlation between Wr of NS and density of NNS was investigated through linear regression analysis and covariance analysis. Preliminary results encourage the use of Wr as a tool to assess the relationship between NS and ecological factors (such as the presence of NNS and to explain the changes that occur along the longitudinal gradient of a river.

  18. Amplification of a GC-rich heterochromatin in the freshwater fish Leporinus desmotes (Characiformes, Anostomidae

    Directory of Open Access Journals (Sweden)

    Vladimir Pavan Margarido

    2000-09-01

    Full Text Available This is the first description of the karyotype of Leporinus desmotes. The diploid female number was 2n = 54 meta- and submetacentric chromosomes. The nucleolar organizing regions (NORs were studied by silver nitrate staining and rDNA fluorescence in situ hybridization (FISH and were found to be located in the telomeric region of the long arm of the 9th pair. C-banding revealed centromeric and telomeric heterochromatin segments in most chromosomes. Intercalar blocks of heterochromatin were observed in the long arm of six chromosome pairs. Besides a NOR-adjacent heterochromatin, all of the intercalar heterochromatic segments were brightly fluorescent by mithramycin staining. These data suggest that a unique amplification of a primordial GC-rich heterochromatin, probably NOR-associated, may have taken place in the karyotype diversification of this Leporinus species.Esta é a primeira descrição do cariótipo de Leporinus desmotes fêmea. O número diplóide encontrado foi 2n = 54 cromossomos meta- e submetacêntricos. As regiões organizadoras de nucléolos (NORs foram estudadas através da impregnação pela prata e por hibridização in situ com sondas de DNAr (FISH, e foram localizadas na região telomérica do braço longo do 9º par. Heterocromatinas centromérica e telomérica foram reveladas pelo bandamento C na maioria dos cromossomos. Adicionalmente, grande quantidade de heterocromatina intercalar ou subtelomérica foi também observada. Diferenciação composicional na maior parte da heterocromatina identificada em L. desmotes pode ser inferida através da coloração pela mitramicina, caracterizando um caso peculiar de amplificação de segmentos heterocromáticos ricos em bases GC neste grupo de peixes.

  19. Nutrient budgets and effluent characteristics in giant freshwater prawn (Macrobrachium rosenbergii) culture ponds.

    Science.gov (United States)

    Adhikari, Subhendu; Sahu, Bharat Chandra; Mahapatra, Abhijit S; Dey, Lambodar

    2014-05-01

    It is important to understand nutrient budgets of aquaculture practices for efficiency of input resources and to utilize all output nutrient sources. The aim of the present study was to develop a nutrient budget for giant freshwater prawn (Macrobrachium rosenbergii) culture ponds. The study was conducted in farmer's ponds (0.25-0.5 ha) of Odisha, India, and the results showed that feed accounted 97% total nitrogen (N), 98.7% total phosphorus (P) and 90% total organic carbon (OC), respectively. The harvested prawn accounted for recovery of 37% N, 10% P and 15% OC, respectively. The N, P and OC accumulated in sediment were 52%, 76%, and 65%, respectively. Nutrient loads in the effluents were 2.22 ± 0.66 kg inorganic N, 0.40 ± 0.15 kg P, and 21.01 ± 6.4 kg OC per ton of prawn production. The present study implicated that high nutrient values observed in both water and sediment provide important opportunities for nutrient reuse through pond sediment applications to croplands as an organic manure, as well as pond water irrigation to crops as a "liquid fertilizer".

  20. Length-weight relationships for 36 freshwater fish species from two tropical reservoirs: Ayamé I and Buyo, Côte d’Ivoire

    Directory of Open Access Journals (Sweden)

    Leonard Tah

    2012-12-01

    Full Text Available Nowadays, the successful management of small scale fisheries requires the use of biometric data collected in the field, in order to transform them into suitable indicators. The present study describes the lengthweight relationships for 36 freshwater fish species from two tropical reservoirs Ayame I and Buyo, in Côte d’Ivoire. The main objective of the study was to provide a length weight key for a wide range of freshwater fish species from these tropical reservoirs exploited by the inland fisheries. The samplings were carried out at Buyo from July 1997 to August 1998, and from August 2004 to July 2005 in Ayame I. Fish specimens were collected from catches of artisanal fisheries using gill-nets, cast-nets, beach seines and bamboo traps. After landings, samples were identified, total weight for each specimen was recorded to the nearest gram and standard length was measured to the nearest millimetre. A total of 12 724 individuals belonging to 15 families and 24 genera were obtained in this study. The results indicated that the family with the highest number of species was Cichlidae with eight species. Six families were recorded with only one species per family. The value of the exponent b in the length weight relationships (W=aLb ranged from 2.173 for Marcusenius furcidens to 3.472 for Polypterus endlicheri and the median of b was 2.756. The modal value of the exponent b equal to 2.70 indicates that most of the fish species in Ayame I and Buyo Reservoirs have negative allometric growth. The length weight parameters of the three species, Lates niloticus, Synodontis koensis and S. punctifer are described for the first time in these regions. The present length-weight key for 36 freshwater fish species could be used as a valuable tool for fishery managers, in order to improve the inland fisheries statistics largely based on hydropower reservoirs in Côte d’Ivoire.

  1. Length-weight relationships for 36 freshwater fish species from two tropical reservoirs: Ayamé I and Buyo, Côte d'Ivoire.

    Science.gov (United States)

    Tah, Leonard; Gouli; Bi, Goore; Da Costa, Kouassi Sebastino

    2012-12-01

    Nowadays, the successful management of small scale fisheries requires the use of biometric data collected in the field, in order to transform them into suitable indicators. The present study describes the length-weight relationships for 36 freshwater fish species from two tropical reservoirs Ayame I and Buyo, in Côte d'Ivoire. The main objective of the study was to provide a length weight key for a wide range of freshwater fish species from these tropical reservoirs exploited by the inland fisheries. The samplings were carried out at Buyo from July 1997 to August 1998, and from August 2004 to July 2005 in Ayame I. Fish specimens were collected from catches of artisanal fisheries using gill-nets, cast-nets, beach seines and bamboo traps. After landings, samples were identified, total weight for each specimen was recorded to the nearest gram and standard length was measured to the nearest millimetre. A total of 12 724 individuals belonging to 15 families and 24 genera were obtained in this study. The results indicated that the family with the highest number of species was Cichlidae with eight species. Six families were recorded with only one species per family. The value of the exponent b in the length weight relationships (W=aL(b)) ranged from 2.173 for Marcusenius furcidens to 3.472 for Polypterus endlicheri and the median of b was 2.756. The modal value of the exponent b equal to 2.70 indicates that most of the fish species in Ayame I and Buyo Reservoirs have negative allometric growth. The length weight parameters of the three species, Lates niloticus, Synodontis koensis and S. punctifer are described for the first time in these regions. The present length-weight key for 36 freshwater fish species could be used as a valuable tool for fishery managers, in order to improve the inland fisheries statistics largely based on hydropower reservoirs in Côte d'Ivoire.

  2. Exploring the relationship between convenience and fish consumption: A cross-cultural study

    DEFF Research Database (Denmark)

    Olsen, Svein Ottar; Scholderer, Joachim; Brunsø, Karen

    2007-01-01

    The purpose of the present study is to explore cultural differences in the meaning of convenience and the relationships between convenience, attitudes and fish consumption in five European countries. The results suggest that the meaning of meal convenience is not culture specific, whilst...... the absolute levels of convenience orientation and the perceived inconvenience of fish differ between cultures. Convenience orientation was highest in Poland, followed by Spain, and was lowest in the Netherlands. The relationships between convenience orientation and attitudes towards fish, and convenience...... orientation and fish consumption, were insignificant in most countries. However, convenience orientation was positively related to the perceived inconvenience of fish. Perceived inconvenience of fish was negatively related to both attitudes towards fish and to fish consumption. Together, these results confirm...

  3. Bacteriological quality of aquacultured freshwater fish portions in prepackaged trays stored at 3 degrees C.

    Science.gov (United States)

    González-Rodríguez, M N; Sanz, J J; Santos, J A; Otero, A; García-López, M L

    2001-09-01

    Fresh trout fillets and salmon slices packed in trays were obtained from two multinational chain supermarkets and evaluated for freshness and bacteriological quality immediately after packaging and during storage at 3 degrees C. Initial aerobic counts at 30 and 25 degrees C were significantly (P fish was spoiled. Although initial presumptive Staphylococcus aureus counts were approximately 3 log CFU/g, only 4 of 84 selected colonies belonged to this species. Neither Salmonella nor antimicrobial residues were detected in any sample. Ethanol content in salmon slices did not significantly (P > 0.05) increase until they became inedible. Significant correlation (r = +0.72, P < 0.05) was observed between this chemical index and viable counts at 30 degrees C only when salmon slices were inedible. Trout fillets were acceptable for 7 days, and salmon slices showed signs of spoilage after 4 days. Although public health concerns associated with packed trout and salmon appear to be minimal, data on sensory quality, shelf life, and total viable and Enterobacteriaceae counts strongly suggest the need to improve the quality control systems used by European multinational retailers, especially for imported salmon.

  4. Invasion risks posed by ornamental freshwater fish trade to southeastern Brazilian rivers

    Directory of Open Access Journals (Sweden)

    André Lincoln Barroso de Magalhães

    Full Text Available A model was developed to assess the risk of invasion of ornamental non-native fishes to six rivers in the state of Minas Gerais, southeastern Brazil, with focus on species popularity. Thirty-nine aquarium shops, in six cities, were visited monthly from January to December 2007. In each city, fish species were identified, and their biology and invasion history information was obtained from the literature. We calculated the annual frequency of occurrence and average number of specimens monthly available in stores. Quarterly water temperature and dissolved oxygen data from 1997 to 2007 were obtained for the Velhas, Muriaé, Uberabinha, Sapucaí-Mirim, Doce and Todos os Santos Rivers from public databases. The invasion risk of each species was assessed through a model comprising nine parameters grouped in four variables: (i Invasiveness (thermal and dissolved oxygen ranges, diet, parental care or fecundity, (ii History of invasions (establishment, (iii Propagule pressure (commercial success, comprising annual frequency of occurrence and number of specimens available monthly at stores, and (iv Invasibility (water temperature and dissolved oxygen in the target river compatible with the species ranges. Of the 345 ornamental fish species for sale, 332 are non-native to either Minas Gerais (n = 151 or Brazil (n = 194. Based on the proposed cutting values, in particular the compatibility between species and recipient thermal ranges, five ornamental non-native species (Cyprinus rubrofuscus, Carassius auratus, Xiphophorus hellerii, Poecilia reticulata, and P. latipinna can potentially invade the Velhas and Muriaé Rivers, four species (Cyprinus rubrofuscus, Carassius auratus, X. helleri, and P. reticulata the Uberabinha River, four species (Cyprinus rubrofuscus, Carassius auratus, X. maculatus, and P. reticulata the Sapucaí-Mirim River, three species (Carassius auratus, X. hellerii, and P. reticulata the Doce River, and three species (Cyprinus rubrofuscus

  5. Past connection and isolation of catchments: The sea-level changes affect the distribution and genetic variability of coastal freshwater fishes

    Science.gov (United States)

    Tschá, Marcel K.; Bachmann, Lutz; Abilhoa, Vinícius; Boeger, Walter A.

    2017-05-01

    The Atlantic coast of South America is characterized by a great diversity and endemism of fishes. Past eustatic changes that promoted cycles of isolation, expansion, and connection of coastal catchments are considered putative drivers of genetic differentiation and phylogenetic diversity. It is hypothesized that recent eustatic movements have left signs of impact on the demographic history and local distribution patterns of freshwater fishes. This study addressed the phylogeography and demographic history of two siluriform (Scleromystax barbatus, Rineloricaria sp.) and one characiform (Mimagoniates microlepis) fish species from the coastal plain of the state of Paraná, Paranaguá Bay, Brazil. Nucleotide sequence data of the mitochondrial cytochrome b gene support the hypothesis that the populations of the three species are genetically differentiated at all sampled catchments. Haplotype networks of these populations indicate different histories and include scenarios of secondary contact, population expansion, and isolation. Neutrality tests and the reconstructed patterns of demographic history in mismatch distributions were also consistent with population expansion in the western basins and, in general, secondary contact in the northern basins. Our results are consistent with the reconstructed paleodrainage in the region and with the hypothesis that recurrent reconnections and isolation of streams associated with eustatic changes have strongly influenced the current pattern of diversity, and reflect the distribution of freshwater fishes in this coastal hydrographic system.

  6. Biochemical biomarkers of exposure to deltamethrin in freshwater fish, Ancistrus multispinis

    Directory of Open Access Journals (Sweden)

    Helena Cristina da Silva de Assis

    2009-12-01

    Full Text Available This study aimed to determine the effect of sublethal doses of deltamethrin, using biochemical biomarkers as activities of cholinesterase (ChE, ethoxyresorufin-O-deethylase (EROD and the Na+K+- ATPase and levels of total cytochrome P450 (CYP450. Fishes received sublethal doses of deltamethrin and were sacrificed after 96 h of exposure. Samples of gills, heart, brain, liver and muscle were collected for enzymatic analyses. Deltamethrin inhibited the activity of the gills and heart Na+ K+-ATPase, induced the liver total CYP450, as well as the liver EROD activity. The activity of the ChE was not inhibited by deltamethrin. Deltamethrin altered the hepatic metabolism and the normal ionic flux in Ancistrus multispinis.Deltametrina é um inseticida piretroide, usado in agricultura, na medicina veterinária a em saúde pública devido a sua baixa toxicidade para mamíferos. Contudo, para espécies não alvo como os peixes a deltametrina é extremamente tóxica. Esse estudo tem por objetivo determinar o efeito de doses subletais de deltametrina, usando biomarcadores bioquímicos como atividade da colinesterase (ChE, níveis totais de citocromo P450 (CYP450, atividade da ethoxyresorufin-O-deethylase (EROD e da Na+K+-ATPase. Os peixes receberam doses subletais de deltametrina e após 96 horas de exposição foram sacrificados e o fígado, brânquias, coração e músculo foram coletados para as medidas enzimáticas. A atividade da Na+K+-ATPase em brânquias e coração foi inibida. A deltametrina aumentou os níveis de CYP450 total, bem como a atividade da EROD. A atividade da ChE não foi inibida. Deltametrina alterou a atividade da Na+K+-ATPase e desta forma o fluxo normal de ions em A. multispinnis, bem como seu metabolismo hepático. Os efeitos detectados através de biomarcadores tornam esse inseticida um importante contaminante para organismos aquáticos.

  7. Community based fish culture in the public and private floodplains of Bangladesh

    NARCIS (Netherlands)

    Mahfuzul Haque, A.B.

    2015-01-01

    Seasonal floodplains are water bodies that retain water for 5-6 months during which they are suitable to grow fish and other aquatic animals. Out of 2.8 million ha of medium and deep-flooded areas, about 1.5 million ha are estimated to be suitable for Community-Based Fish Culture (CBFC). WorldFish h

  8. Community based fish culture in the public and private floodplains of Bangladesh

    NARCIS (Netherlands)

    Mahfuzul Haque, A.B.

    2015-01-01

    Seasonal floodplains are water bodies that retain water for 5-6 months during which they are suitable to grow fish and other aquatic animals. Out of 2.8 million ha of medium and deep-flooded areas, about 1.5 million ha are estimated to be suitable for Community-Based Fish Culture (CBFC). WorldFish h

  9. Community based fish culture in the public and private floodplains of Bangladesh

    NARCIS (Netherlands)

    Mahfuzul Haque, A.B.

    2015-01-01

    Seasonal floodplains are water bodies that retain water for 5-6 months during which they are suitable to grow fish and other aquatic animals. Out of 2.8 million ha of medium and deep-flooded areas, about 1.5 million ha are estimated to be suitable for Community-Based Fish Culture (CBFC). WorldFish

  10. Study on the Toxicity of Extract from Seed Cake of Camellia oleifera Abel to Freshwater Fishes, Shrimps and Snails%油茶饼粕浸出液对淡水鱼·虾·螺的毒性研究

    Institute of Scientific and Technical Information of China (English)

    叶显峰; 郑世雄; 祖国掌; 徐启龙; 赵同德; 谢士峰; 李国峰

    2011-01-01

    snails had higher tolerance to extract from C. oleifera, [Conclusion] It is of good foreground to control wild fishes and prevent and treat the diseases in artificial culture of freshwater shrimps and crabs by using extract from C. oleifera.

  11. Laboratory and field validation of a simple method for detecting four species of non-native freshwater fish using eDNA.

    Science.gov (United States)

    Davison, P I; Créach, V; Liang, W-J; Andreou, D; Britton, J R; Copp, G H

    2016-09-01

    This paper presents the first phase in the development and validation of a simple and reliable environmental (e)DNA method using conventional PCR to detect four species of non-native freshwater fish: pumpkinseed Lepomis gibbosus, sunbleak Leucaspius delineatus, fathead minnow Pimephales promelas and topmouth gudgeon Pseudorasbora parva. The efficacy of the approach was demonstrated in indoor tank (44 l) trials in which all four species were detected within 24 h. Validation was through two field trials, in which L. gibbosus was detected 6-12 h after its introduction into outdoor experimental ponds and P. parva was successfully detected in disused fish rearing ponds where the species was known to exist. Thus, the filtration of small (30 ml) volumes of pond water was sufficient to capture fish eDNA and the approach emphasised the importance of taking multiple water samples of sufficient spatial coverage for detecting species of random or patchy distribution.

  12. Characterization and Antibacterial Potential of Lactic Acid Bacterium Pediococcus pentosaceus 4I1 Isolated from Freshwater Fish Zacco koreanus

    Directory of Open Access Journals (Sweden)

    Vivek K. Bajpai

    2016-12-01

    Full Text Available This study was undertaken to characterize a lactic acid bacterium 4I1, isolated from the freshwater fish, Zacco koreanus. Morphological, biochemical and molecular characterization of 4I1 revealed it to be Pediococcus pentosaceus 4I1. The cell free supernatant (CFS of P. pentosaceus 4I1 exhibited significant (p<0.05 antibacterial effects (inhibition zone diameters: 16.5–20.4 mm against tested foodborne pathogenic bacteria with MIC and MBC values of 250-500 and 500-1,000 µg/mL, respectively. Further, antibacterial action of CFS of P. pentosaceus 4I1 against two selected bacteria Staphylococcus aureus KCTC-1621 and Escherichia coli O157:H7 was determined in subsequent assays. The CFS of P. pentosaceus 4I1 revealed its antibacterial action against S. aureus KCTC-1621 and E. coli O157:H7 on membrane integrity as confirmed by a reduction in cell viability, increased potassium ion release (900 and 800 mmol/L, reduced absorption at 260-nm (3.99 and 3.77 OD, and increased relative electrical conductivity (9.9 and 9.7%, respectively. Gas chromatography-mass spectrometry (GC-MS analysis of the CFS of P. pentosaceus 4I1 resulted in the identification of seven major compounds, which included amino acids, fatty acids and organic acids. SEM-based morphological analysis further confirmed the antibacterial effect of CFS of P. pentosaceus 4I1 against S. aureus KCTC-1621 and E. coli O157:H7. In addition, the CFS of P. Pentosaceus 4I1 displayed potent inhibitory effects on biofilms formation by S. aureus KCTC-1621 and E. coli O157:H7. The study indicates the CFS of P. pentosaceus 4I1 offers an alternative means of controlling foodborne pathogens.

  13. Evaluating the effects of laboratory protocols on eDNA detection probability for an endangered freshwater fish.

    Science.gov (United States)

    Piggott, Maxine P

    2016-05-01

    The effectiveness and accuracy of detection using environmental DNA (eDNA) is dependent on understanding the influence laboratory methods such as DNA extraction and PCR strategies have on detection probability. Ideally choice of sampling and extraction method will maximize eDNA yield and detection probability. Determining the survey effort required to reach a satisfactory detection probability (via increased PCR replicates or more sampling) could compensate for a lower eDNA yield if the sampling and extraction method has other advantages for a study, species or system. I analysed the effect of three different sampling and extraction methods on eDNA yield, detection probability and PCR replication for detecting the endangered freshwater fish Macquaria australasica from water samples. The impact of eDNA concentration, PCR strategy, target amplicon size and two marker regions: 12S (a mitochondrial gene) and 18S (a nuclear gene) was also assessed. The choice of sampling and extraction method and PCR strategy, rather than amplicon size and marker region, had the biggest effect on detection probability and PCR replication. The PCR replication effort required to achieve a detection probability of 0.95, ranged from 2 to 6 PCR replicates depending on the laboratory method used. As all methods yielded eDNA from which M. australasica was detected using the three target amplicons, differences in eDNA yield and detection probability between the three methods could be mitigated by determining the appropriate PCR replication effort. Evaluating the effect sampling and extraction methods will have on the detection probability and determining the laboratory protocols and PCR replication required to maximize detection and minimize false positives and negatives is a useful first step for eDNA occupancy studies.

  14. Culture, hydrology, and other situational controls on atoll freshwater availability (Majuro, Republic of the Marshall Islands)

    Science.gov (United States)

    Shuster, W.

    2016-12-01

    The comparatively uncertain rainfall catch and rising seas in isolated North Pacific atoll communities has presented serious challenges to maintain human communities with freshwater volume. Moreover, the feudal hierarchy, which structures social and economic relationships among local governance and citizens contributes equally to problems and potential solutions. These relationships modulate the availability of critical ecosystem services generated by freshwater, with additional constraints contributed by climate change, rainfall variability (e.g., current El Niño climate pattern), and continuous threat of drought. The major freshwater resources for an atoll are the groundwater freshwater lens, residential and commercial rainwater harvesting, large-scale rainfall catchments (e.g., an airport runway), imported-virtual water, or desalinization subsidies. The significance of each of these resources scale across different atolls according to size, topography, soils, population, infrastructure, and land ownership. The potential integration and coordination of these water resources is largely unrealized due to land ownership, the lack of a contiguous catchment area, uneven and fractured governance. The situational aspects are further characterized by feuding among families and communities (some resource rich, some resource poor), and conflicting land use priorities where agriculture placement and practice can compromise the quality of already limited freshwater resources. This presentation uses the example of Majuro atoll (Republic of the Marshall Islands), field data and other observations, to illustrate sociohydrologic-drivers of freshwater availability, and suggests approaches that may improve on current and ongoing threats to public health and well-being.

  15. Sodium turnover rate determines sensitivity to acute copper and silver exposure in freshwater animals

    DEFF Research Database (Denmark)

    Grosell, Martin Hautopp; Nielsen, Claus; Bianchini, A.

    2002-01-01

    Copper, Silver, Freshwater, Fish, Crustaceans, Sodium transport, Ammonia excretion, Predicting mortality......Copper, Silver, Freshwater, Fish, Crustaceans, Sodium transport, Ammonia excretion, Predicting mortality...

  16. The Sustainability of Aquaculture as a Farm Enterprise: Impacts and Consequences of Fish Culture in Rwanda.

    Science.gov (United States)

    Molnar, Joseph J.; And Others

    Rwanda, a small country in Africa, has experienced declines in per capita food production. Fish culture is one part of a many-stranded effort to increase food production and food security by intensifying the use of land resources to produce a much-needed protein crop. Beginning in 1983, the Rwanda National Fish Culture Project has assisted farmers…

  17. Phylogeography, historical demography and distribution modelling of freshwater fishes inhabiting seasonally fluctuating Mediterranean river systems: a case study using the Iberian cyprinid Squalius valentinus

    Directory of Open Access Journals (Sweden)

    Silvia Perea

    2015-12-01

    Full Text Available The Mediterranean freshwater fish fauna has evolved under constraints imposed by the seasonal weather/hydrological patterns that define the Mediterranean climate. These conditions have influenced the genetic and demographic structure of aquatic communities since their origins in the Mid-Pliocene. Freshwater species in Mediterranean-type climates will likely constitute genetically well-differentiated populations as a consequence of fragmentation resulting from drought/flood cycles, to varying extents depending on basin size. We developed an integrative framework to study spatial patterns in genetic diversity, demographic trends, distribution modelling, and landscape genetics to evaluate the evolutionary response of Mediterranean-type freshwater fish to seasonal fluctuations in weather. To test this evolutionary response, the model species used was Squalius valentinus, an endemic cyprinid of the Spanish Levantine area, where seasonal weather fluctuations are extreme, although our findings may be extrapolated to other Mediterranean-type species. Our results underscore the significant role of the Mediterranean climate, along with Pleistocene glaciations, in diversification of S. valentinus. We found higher nuclear diversity in larger drainage basins, but higher mitochondrial diversity correlated to habitat suitability rather than basin size. We also found strong correlation between genetic structure and climatic factors associated with Mediterranean seasonality. Demographic and migration analyses suggested population expansion during glacial periods that also contributed to the current genetic structure of S. valentinus populations. The inferred species distribution models support the significant contribution of precipitation and isothermality for S. valentinus habitat suitability. We highlight the importance of stable habitat conditions, fostered by typical karstic springs found on the Mediterranean littoral coasts, for the preservation of

  18. A Review of Topography in Fish Culture in Nigeria Part 1

    Directory of Open Access Journals (Sweden)

    J.F.N. Abowei

    2011-10-01

    Full Text Available A review of topography in fish culture in Nigeria part two is aimed at bridging the technical language gap between the fish culturist and; both land surveyors and civil engineers. The fish culturists need to understand the principles in topography for good site selection in fish culture. The fish farmer can design and build fishponds, reservoirs and small dams and use existing topographical maps. An adequate knowledge of topography by fish culturist bridges the technical language gap between the fish culturist and; both land surveyors and civil engineers. The fish culturist can discuss his plans, projects and understand books on topography, engineering and surveying. Good fish farm construction can only be possible with the right topography. Features of a fish pond, different kinds of pond, advantages and disadvantages of these types of pond, basic pond types, characteristics of shallow and deep ponds, setting out a straight line between two points, prolonging a line, horizontal distance measurement, pace count, chaining, clisimeter, stadia method are some principles in topography for good site selection in fish culture reviewed in this part aimed at enabling the fish culturists know these basic principles to design and build fishponds, reservoirs and small dams and use existing topographical maps.

  19. Toxicity of the Herbicide Atrazine: Effects on Lipid Peroxidation and Activities of Antioxidant Enzymes in the Freshwater Fish Channa Punctatus (Bloch

    Directory of Open Access Journals (Sweden)

    Satish Kumar Srivastava

    2010-08-01

    Full Text Available The present study was undertaken to evaluate the toxicity and effects of a commercial formulation of the herbicide atrazine (Rasayanzine on lipid peroxidation and antioxidant enzyme system in the freshwater air breathing fish Channa punctatus. The 12, 24, 48, 72 and 96 h LC50 of atrazine, calculated by probit analysis, were determined to be 77.091, 64.053, 49.100, 44.412 and 42.381 mg·L-1, respectively, in a semi static system with significant difference (p < 0.05 in LC10-90 values obtained for different times of exposure. In addition to concentration and time dependent decrease in mortality rate, stress signs in the form of behavioral changes were also observed in response to the test chemical. In fish exposed for 15 days to different sublethal concentrations of the herbicide (1/4 LC50 = ~10.600 mg·L-1, 1/8 LC50 = ~5.300 mg·L-1 and 1/10 LC50 = ~4.238 mg·L-1 induction of oxidative stress in the liver was evidence by increased lipid peroxidation levels. The antioxidants superoxide dismutase (SOD, catalase (CAT and glutathione reductase (GR responded positively in a concentration dependent pattern, thus, suggesting the use of these antioxidants as potential biomarkers of toxicity associated with contaminations exposure in freshwater fishes.

  20. Improving the culturability of freshwater bacteria using FW70, a low-nutrient solid medium amended with sodium pyruvate.

    Science.gov (United States)

    Imazaki, Iori; Kobori, Youichi

    2010-04-01

    Bacterial culture based on the use of plate media is an effective method for investigating bacterial populations in the environment. To improve the culturability of bacteria from freshwater lakes, we developed a new medium, FW70, which contains sodium pyruvate, casamino acids, and lake water and is solidified using gellan gum. To test the importance of these components, we prepared a series of media in which one or more of the components was absent. Water was sampled 31 times from 3 Japanese lakes and was passed through a membrane filter (pore size = 0.45 microm) to remove fast-growing microbes before the water was spread onto the plates. In most cases, significantly larger numbers of bacterial colonies were detected on FW70 than on other media. Furthermore, to test the practicality of FW70, we compared it with standard nutrient agar and R2A agar. In all cases, the culturability was significantly greater on FW70 than on standard nutrient agar or R2A agar. Some isolates recovered by means of FW70 belonged to bacteria that had not previously been classified. These results suggest that FW70 improves the culturability of freshwater bacteria and can be used for the isolation of novel bacteria as a result of the filtration step.

  1. Fish culture in heated effluents (eastern Europe). [Growth increase in carp and rainbow trout

    Energy Technology Data Exchange (ETDEWEB)

    Backiel, T.; Gay, B.; La Croix, M.J.B.; Ophel, I.L. (eds.)

    1976-01-01

    Dependence of growth and reproduction of cultivated fishes on temperature are briefly reviewed. Experiments with and commercial-size operations of various methods of fish culture with the use of heated effluents are exemplified. Cage culture, earthen ponds, flowing water culture have demonstrated possibilities of growth increase in carp and rainbow trout and of controlled reproduction of the former. Problems involved in utilization of various systems and several points of view on the use of low-grade heat for fish culture are considered.

  2. Acute and chronic effects of diazinon on the activities of three dehydrogenases in the digestive system of a freshwater teleost fish Channa punctatus.

    Science.gov (United States)

    Sastry, K V; Malik, P V

    1982-01-01

    The effect of acute exposure to LC50 for 96 h (3.1 mg/l) and chronic exposure to a sublethal concentration (0.31 mg/l) of diazinon has been studied in the liver, stomach, intestine and pyloric ceca of a freshwater teleost fish, Channa punctatus. In acute exposure succinate dehydrogenase (SDH) activity was elevated in intestine and pyloric ceca. No alteration was noted in lactate dehydrogenase activity but pyruvate dehydrogenase was inhibited in pyloric ceca. Chronic exposure resulted in inhibition of the activities of the three dehydrogenases in all the four parts at both intervals.

  3. Genotoxicity of freshwater ecosystem shows DNA damage in preponderant fish as validated by in vivo micronucleus induction in gill and kidney erythrocytes.

    Science.gov (United States)

    Obiakor, M O; Okonkwo, J C; Ezeonyejiaku, C D

    2014-12-01

    Genotoxicity of Anambra River was studied by micronucleus (MN) assay of preponderant fish species in the river. The micronucleus indices obtained were used as biomarker to estimate and predict pollution profile and possible danger of feeding on the aquatic species. Micronuclei profile of the fish was measured from gill and kidney erythrocytes using microscopic technique. Season, species and location effects on micronuclei, together with their interactions were also determined. Two major seasons (rainy and dry) and preponderant fish species in the river (Synodontis clarias, Linnaeus, 1758 and Tilapia nilotica, Linnaeus, 1757) were studied at five distinct locations that displayed differential environmental stresses. The study showed that the micronucleus index of fish is an excellent biomarker for measuring pollution level and genotoxicity of freshwater habitat. Season, species of fish and location affect micronuclei profile of the fish species sampled in the river. Disease outbreak among rural dwellers depending on the river for domestic and other uses is imminent and they lack knowledge on its health implication. Moreover, the study maintained that the micronuclei in fish could be measured from either the gill or kidney; however, gill is more efficient as it enables collection of several samples from the same individuals without sacrificing it, and Synodontis clarias fish species appeared to be more vulnerable to the genotoxic damage than Tilapia nilotica. Consequently, the study recommended regular monitoring (micronucleus tests) of edible aquatic life such as Synodontis clarias in order to eliminate the danger of people feeding on toxic metals, some of which are carcinogenic. Copyright © 2014 Elsevier B.V. All rights reserved.

  4. An overview of freshwater fish aging in South America: the science, biases and future directions - doi: 10.4025/actascibiolsci.v32i4.8664 An overview of freshwater fish aging in South America: the science, biases and future directions - doi: 10.4025/actascibiolsci.v32i4.8664

    Directory of Open Access Journals (Sweden)

    Erivelto Goulart

    2010-11-01

    Full Text Available South America harbors the largest freshwater diversity in the world (about 4,475 valid species. Aging studies of 153 species published in 92 papers were reviewed for this publication. They were categorized according to the journal where they were published, decade, number of researches per river basin, methods and structures most used to estimate age, validation methods, period and causes of the formation of the age ring and age of the fish in South America. Our results showed an increase in the studies of age and growth, especially in the Paraná river basin. Scales were the structure most used in the studies of aging. Most of the researchers did not validate age. On a continental level, there was no specific period for growth ring formation, but in general, it was related to reproductive activity and flooding period. South American freshwater fishes did not present high longevity (maximum of 15 years. The ongoing governmental support to the fishery in South America, such as in Brazil with the creation of the Ministry of Fishing and Aquaculture, will certainly enlarge the fishing industry. Thus, it is necessary to know and to evaluate the fishery stocks correctly in order to guarantee sustainable use.South America harbors the largest freshwater diversity in the world (about 4,475 valid species. Aging studies of 153 species published in 92 papers were reviewed for this publication. They were categorized according to the journal where they were published, decade, number of researches per river basin, methods and structures most used to estimate age, validation methods, period and causes of the formation of the age ring and age of the fish in South America. Our results showed an increase in the studies of age and growth, especially in the Paraná river basin. Scales were the structure most used in the studies of aging. Most of the researchers did not validate age. On a continental level, there was no specific period for growth ring formation, but

  5. Heavy metal profile of water, sediment and freshwater cat fish, Chrysichthys nigrodigitatus (Siluriformes: Bagridae, of Cross River, Nigeria

    Directory of Open Access Journals (Sweden)

    Ezekiel Olatunji Ayotunde

    2012-09-01

    Full Text Available Cross River serves as a major source of drinking water, transportation, agricultural activities and fishing in Cross River State, Nigeria. Since there is no formal control of effluents discharged into the river, it is important to monitor the levels of metals contaminants in it, thus assessing its suitability for domestic and agricultural use. In order to determine this, three sampling stations designated as Ikom (Station I, Obubra Ogada (Station II and Calabar (Station III were randomly selected to study. For this, ten samples of the freshwater Silver Catfish (Chryshchythys nigrogitatus (29.4-39.5cm SL, 310-510g, sediment and water were collected from each sampling Station from June 2009-June 2010. The heavy metals profiles of Zn, Cu, Fe, Co, Pb, Cd and Cr, in water, sediments and fish muscle were analyzed by atomic absorption spectrophotometry (AAS. In fish, the heavy metals concentration was found to be Cu>Fe>Zn>Cu>Pb>Cd>Co; the highest mean concentration of Copper (0.297±0.022 μg/g, Cadmium (0.011±0.007μg/g, Iron (0.371±0.489μg/g, Lead (0.008±0.008μg/g, were determined for the fish. In water, the order was found to be Fe>Pb>Zn>Cu>Cr>Cd>Co; the highest mean concentration of Iron (0.009±0.00μg/g, Copper (0.015±0.01 μg/g, Lead (0.0002±0.00μg/g Cadmium (0.0006±0.001μg/g, Zinc (0.0036±0.003μg/g, were observed in the surface water, respectively. The highest mean concentration of Copper (0.037±0.03μg/g, Iron (0.053±0.04μg/g, Lead (0.0002±0.00μg/g, Cobalt (0.0002±0.00μg/g, Cadmium (0.0006±0.001μg/g and Zinc (.009±0.0015μg/g was observed in the bottom water. In sediments, the concentration order found was Zn>Fe>Cu>Pb>Co>Cd; the highest mean concentration of 0.057±0.04μg/g, 0.043±0.03μg/g, 0.0006±0.00μg/g, 0.0002±0.00μg/g, 0.0009±0.00μg/g, 0.099±0.00404μg/g in Iron, Copper, Lead, Cobalt, Cadmium and Zinc were observed in the sediment, respectively; Chromium was not detected in the sediment for the whole

  6. Limnological study with reference to fish culture of Bothali (Mendha) reservoir, district - Gadchiroli (India).

    Science.gov (United States)

    Tijare, Rajendra V

    2012-04-01

    Limnological study with reference to fish culture was carried out at Bothali (Mendha) reservoir, district Gadchiroli, India. Water samples from different sampling locations were collected and processed for physico-chemical analysis. The physico-chemical analysis revealed that the reservoir is favourable for fish culture as the phosphate content in water is moderate in amount. This reservoir can produce a good yield of fishes. Though the reservoir is presently exploited and is under pisciculture, a better treatment of the reservoir such as prevention of entry of organic matter, reduction of phosphate ion concentration to certain extent is necessary to obtain a maximum fish yield.

  7. A new species of Henneguya, a gill parasite of a freshwater fish Anabas testudineus (Bloch) affected with ulcerative disease syndrome from Manipur, India.

    Science.gov (United States)

    Hemanand, Th; Meitei, N Mohilal; Bandyopadhyay, Probir K; Mitra, Amlan K

    2008-01-01

    A new species of Henneguya parasitizing tissues affected by the ulcerative disease syndrome of a freshwater fish Anabas testudineus (Bloch) from Khiodum and Pumlen lakes of Manipur state is described. Of the fishes examined 75% were found to be infested with this myxozoan parasite. Mature spores of the new species are elongated, biconvex, and oval with bluntly rounded anterior end and gradually tapering posterior end with a caudal prolongation, measuring 12.6-15.4 (14.0+/- 1.1) microm in length. Length of the caudal prolongation is 11.2-12.6 (11.7+/- 0.6) microm. The width of the spores is 5.6-7.0 (6.3+/- 0.5) microm. The length of the polar capsules is 5.6-6.3 (5.5+/- 0.3) microm.

  8. Detection of Vibrio Species Isolated from Ornamental Guppy Fish in Kashan, Isfahan, Iran Fish culturing Pounds

    National Research Council Canada - National Science Library

    Samira Kiani; Nafiseh Sadat Naghavi; Alireza Nazari

    2016-01-01

    .... Materials and methods: In the present study Vibrio species isolated from ornamental guppy fish in Kashan, Isfahan, Iran fish ponds and were detected according to molecular detection and genetic alignment...

  9. Bioaccumulation and depuration of chromium in the selected organs and whole body tissues of freshwater fish Cirrhinus mrigala individually and in binary solutions with nickel

    Institute of Scientific and Technical Information of China (English)

    PL. RM. Palaniappan; S. Karthikeyan

    2009-01-01

    Contamination of aquatic ecosystems with heavy metals has been receiving increased worldwide attention due to their harmful effects on human health and other organisms in the environment.Most of the studies dealing with toxic effects of metals deal with single metal species, while the aquatic organisms are typically exposed to mixtures of metals.Hence, in order to provide data supporting the usefulness of freshwater fish as indicators of heavy metal pollution, it has been proposed in the present study to investigate the bioaccumulation and depuration of chromium in the selected organs of freshwater fingerlings Cirrhinus mrigala, individually and in binary solutions with nickel.The results show that the kidney is a target organ for chromium accumulation, which implies that it is also the "critical" organ for toxic symptoms.The results further show that accumulation of nickel in all the tissues of C.mrigala is higher than that of chromium.In addition, the metal accumulations of the binary mixtures of chromium and nickel are substantially higher than those of the individual metals, indicating synergistic interactions between the two metals.Theoretically the simplest explanation for an additive joint action of toxicants in a mixture is that they act in a qualitatively similar way.The observed data suggest that C.mrigala could be suitable monitoring organisms to study the bioavailability of water-bound metals in freshwater habitats.

  10. Bioaccumulation and risk assessment of per- and polyfluoroalkyl substances in wild freshwater fish from rivers in the Pearl River Delta region, South China.

    Science.gov (United States)

    Pan, Chang-Gui; Zhao, Jian-Liang; Liu, You-Sheng; Zhang, Qian-Qian; Chen, Zhi-Feng; Lai, Hua-Jie; Peng, Feng-Jiao; Liu, Shuang-Shuang; Ying, Guang-Guo

    2014-09-01

    Per- and polyfluoroalkyl substances (PFASs) are used in various industries, which results in their ubiquitous occurrence in the environment. This study determined the concentrations of eighteen PFASs in muscle and liver of nine wild freshwater fish species collected from rivers in the Pearl River Delta (PRD) region, South China, and assessed their bioaccumulation and potential health risks to local people. The results showed that eight and twelve PFASs were detected in the fish muscle and liver samples, respectively. Perfluorooctane sulfonate (PFOS) was found to be the predominant PFAS both in muscle and liver with its highest concentrations of 79ng/g wet weight (ww) in muscle and 1500ng/g ww in liver, followed by Perfluoroundecanoic acid (PFUnDA) and Perfluorotridecanoic acid (PFTrDA) with trace concentrations. The mean PFOS concentrations in fish muscle and liver tissues of the nine collected species ranged from 0.40ng/g in mud carp to 25ng/g in snakehead, and from 5.6ng/g in mud carp to 1100ng/g in snakehead, respectively. Significant positive correlations were found among PFASs both in water and fish, indicating a similar pollution source for these PFASs. In tilapia samples, PFOS concentrations showed an increasing trend with increasing length and weight, but no significant difference between genders. Bioaccumulation factors (logBAF) in fish for the PFASs were in the range from 2.1 to 5.0. The calculated hazard ratios (HR) of PFOS for all fishes were in the range of 0.05-2.8, with four out of nine species (tilapia, chub, leather catfish and snakehead) having their HR values more than 1.0. The results suggest that frequent consumption of these four fish species may pose health risks to local population.

  11. Effects of herbal essential oils used to extend the shelf life of freshwater-reared Asian sea bass fish (Lates calcarifer).

    Science.gov (United States)

    Harpaz, S; Glatman, L; Drabkin, V; Gelman, A

    2003-03-01

    Sensory and microbiological characteristics of Asian sea bass (Lates calcarifer) fish raised in a freshwater pond were evaluated during cold storage for 33 days. Whole fish (averaging 400 g each) were stored in a cold storage room at 0 to 2 degrees C. Essential oils of herbs--thyme (Thymus vulgaris) and oregano (Origanum vulgare)--added at 0.05% (vol/vol) were used as preservatives. On the basis of the sensory test results as well as the bacteriological tests, the addition of oregano and thyme essential oils can considerably slow the process of spoilage. The fish treated with these oils were still fit for human consumption after 33 days of storage. The results obtained through sensory tests are corroborated to a great extent by the chemical (hypoxanthine) tests and to a lesser extent by the physical (Cosmos units) tests. The initial total bacteriological counts were 1.7 x 10(3) CFU/cm2 on the fish surface and fish flesh, and in the control treatment (without preservatives), these counts rose continuously, reaching around 10(7) CFU/cm2 on the fish surface and 10(3) CFU/g in the flesh after 33 days of storage at 0 to 2 degrees C. The use of herbal essential oils as preservatives, on the other hand, resulted in a maximal count of 10(5) CFU/cm2 on the fish surface, while the bacterial count in the flesh remained <10(2) CFU/g by the end of the 33-day storage period at 0 to 2 degrees C.

  12. Morphofunctional changes in Leydig cells throughout the continuous spermatogenesis of the freshwater teleost fish, Serrasalmus spilopleura (Characiformes, Characidae): an ultrastructural and enzyme study.

    Science.gov (United States)

    Nóbrega, R H; Quagio-Grassiotto, I

    2007-08-01

    The freshwater fish Serrasalmus spilopleura (piranha) has a continuous type of reproduction; gametes are constantly produced and released during the reproductive cycle. The testes do not undergo seasonal morphological changes but exhibit two constant regions throughout the year: the medullar region (involved with spermatogenesis) and the cortical region (involved with spermiation and sperm storage). We have evaluated the ultrastructure of the Leydig cells and the activity of 3beta-HSD (an essential enzyme related to steroid hormone biosynthesis) and acid phosphatase (AcPase; lysosomal marker enzyme) in these two regions. The activity of 3beta-HSD is stronger in the medullar region, and the Leydig cells in this region have a variety of cytological features that reflect differences in hormone synthesis and/or that could be linked to steroidogenic cells under various degrees of hormonal activity. In the cortical region, 3beta-HSD activity is weak and the Leydig cells exhibit signs of degeneration, as confirmed by their ultrastructure and intense AcPase activity. These degenerative signs are indicative of cytoplasmic remodelling to degrade steroidogenic enzymes, such as 3beta-HSD, that could lead to senescence or even to autophagic cell degeneration. S. spilopleura thus constitutes an interesting model for increasing our understanding of steroidogenesis control in freshwater teleost fish.

  13. Molecular phylogeny and historical biogeography of the Indonesian freshwater fish Rasbora lateristriata species complex (Actinopterygii: Cyprinidae): Cryptic species and west-to-east divergences.

    Science.gov (United States)

    Kusuma, Wahyu Endra; Ratmuangkhwang, Sahat; Kumazawa, Yoshinori

    2016-12-01

    Rasbora lateristriata is a primary freshwater fish described from Java Island of Indonesia but its taxonomy, phylogeny, and distributional boundary have not been fully studied. Rasbora baliensis was described as a species endemic to Balinese lakes but its taxonomic status has been controversial in relation to R. lateristriata. Here, we collected Rasbora fishes from various freshwater localities of Java Island, as well as five neighboring islands to conduct molecular and morphological analyses on their phylogenetic relationships. Both molecular analyses using two mitochondrial and two nuclear gene sequences and morphological analyses featuring the body color pattern consistently support that the currently recognized R. lateristriata forms a species complex including at least four major lineages that possibly represent different species. In one of the major lineages, Balinese individuals cluster with those from East Javanese, Lombok and Sumbawa localities, calling for taxonomic revision on R. baliensis. The other three major lineages occur in distinct regions of central, west-central, and western Java and they can be clearly distinguished by the combination of pigmentation patterns in the basicaudal blotch and the supra anal pigment. Our molecular phylogeny suggests west-to-east divergences of the R. lateristriata species complex in Java Island from the late Miocene to Plio-Pleistocene before it finally crossed Wallace's Line, colonizing Lombok and Sumbawa Islands very recently. Copyright © 2016 Elsevier Inc. All rights reserved.

  14. Coastal environmental gradients – Key to reproduction habitat mapping of freshwater fish in the Baltic Sea

    OpenAIRE

    Kallasvuo, Meri

    2010-01-01

    Habitat requirements of fish are most strict during the early life stages, and the quality and quantity of reproduction habitats lays the basis for fish production. A considerable number of fish species in the northern Baltic Sea reproduce in the shallow coastal areas, which are also the most heavily exploited parts of the brackish marine area. However, the coastal fish reproduction habitats in the northern Baltic Sea are poorly known. The studies presented in this thesis focused on the ...

  15. Spatial and temporal patterns of mercury concentrations in freshwater fish across the Western United States and Canada

    Science.gov (United States)

    Eagles-Smith, Collin A.; Ackerman, Josh; Willacker, James J.; Tate, Michael T.; Lutz, Michelle A; Fleck, Jacob; Stewart, Robin; Wiener, James G.; Evers, David C.; Lepak, Jesse M; Davis, Jay A; Pritz, Colleen Flanagan

    2016-01-01

    Methylmercury contamination of fish is a global threat to environmental health. Mercury (Hg) monitoring programs are valuable for generating data that can be compiled for spatially broad syntheses to identify emergent ecosystem properties that influence fish Hg bioaccumulation. Fish total Hg (THg) concentrations were evaluated across the Western United States (US) and Canada, a region defined by extreme gradients in habitat structure and water management. A database was compiled with THg concentrations in 96,310 fish that comprised 206 species from 4262 locations, and used to evaluate the spatial distribution of fish THg across the region and effects of species, foraging guilds, habitats, and ecoregions. Areas of elevated THg exposure were identified by developing a relativized estimate of fish mercury concentrations at a watershed scale that accounted for the variability associated with fish species, fish size, and site effects. THg concentrations in fish muscle ranged between 0.001 and 28.4 (μg/g wet weight (ww)) with a geometric mean of 0.17. Overall, 30% of individual fish samples and 17% of means by location exceeded the 0.30 μg/g ww US EPA fish tissue criterion. Fish THg concentrations differed among habitat types, with riverine habitats consistently higher than lacustrine habitats. Importantly, fish THg concentrations were not correlated with sediment THg concentrations at a watershed scale, but were weakly correlated with sediment MeHg concentrations, suggesting that factors influencing MeHg production may be more important than inorganic Hg loading for determining fish MeHg exposure. There was large heterogeneity in fish THg concentrations across the landscape; THg concentrations were generally higher in semi-arid and arid regions such as the Great Basin and Desert Southwest, than in temperate forests. Results suggest that fish mercury exposure is widespread throughout Western US and Canada, and that species, habitat type, and region play an important

  16. Effects of Salinity on Reproduction, Growth and metabolism Related Indicators in Freshwater Fishes%盐度对淡水鱼类繁殖·生长及代谢相关指标的影响

    Institute of Scientific and Technical Information of China (English)

    张龙岗

    2011-01-01

    Effects of the difference in variation of water salinity and treatment time on reproduction, growth, metabolism and other related indicators in freshwater fishes was summerized. It is expect to provide the theory basis for saline-alkali wetland and brackish eraes in freshwater fish farming.%综述了水体盐度变化以及作用时间对淡水鱼类繁殖、生长以及代谢等方面相关指标的影响,以期为半咸水地区淡水鱼养殖提供理论依据.

  17. CROATIAN FRESHWATER FISHERIES IN 1994

    Directory of Open Access Journals (Sweden)

    Mirko Turk

    1995-09-01

    Full Text Available Data on the production and catch of fish according to species, on the surface of the fish ponds, on the means of fish catching and on the distribution of the product and catch in 1994 is presented. The surface area used for production of fish has decreased by 274 ha or 2,51%. The total amount of fish has decreased by 1.263 tons or 14,78%. The highest production of fish was reached by the fish farm Donji Miholjac with 1.231 kg/ha. The feeding coefficient is 3,10 kg. Only on one fish farm was the feeding coefficient less than 2.0 kg (1,40 and on two large farms this coefficient was greater than 5,00 kg. The main fish food is still wheat followed by corn. The amount of fertilizer used was decreased by 14,40%. The fry carp growing ponds make up 0,92% of the surface area of the entire fish farm, the young carp ponds 21,77% and the culturing ponds for consumption fish 76,55%. The total amount of fish in the carp ponds was 660 kg/ha, and in the trout ponds it was 123.4 tons/ha. The carp is the highest produced fish with 80, 35%, then the herbivorous fish with 5,65 and all other fish make up 14% of the total production. In the structure of herbivorous fish the grass carp is leading with 54, 70%, followed by the big head carp with 25,54% and the silver carp with 19,76%. In comparison with the previous year the production of "all other fish- has significantly increased (287%, and sheat fish 18,90%, while the production of trench has decreased (71%. Fish catch in open waters has increased by 20,57% in comparison to the previous year. Carp made up 78,07% of the total production and catch of freshwater fish, the herbivorous fish made up 5,40%, trout 4,38%, the sheat fish, pike perch and pike 2,86% and all other fish species 9,28%. As far as the distribution of production and catch, 51,60% were sold on the market, 37,54% were used for reproduction (stocking the fish farms , mortalities were 6,35% and for personal use (sports fishing 4,50% was used. The number

  18. Fish condition factor, peroxisome proliferator activated receptors and biotransformation responses in Sarotherodon melanotheron from a contaminated freshwater dam (Awba Dam) in Ibadan, Nigeria.

    Science.gov (United States)

    Adeogun, Aina O; Ibor, Oju R; Onoja, Anyebe B; Arukwe, Augustine

    2016-10-01

    The relationship between condition factor (CF), peroxisome proliferator-activated receptors (PPARs), phase 1 biotransformation (CYP1A isoforms) and contaminant burden has been studied in Sarotherodon melanotheron from a contaminated tropical freshwater dam (Awba Dam) and compared to a reference site (Modete Dam) in Southwest, Nigeria. A total of 89 fish (57 males and 32 females) was collected from Awba Dam and 95 fish (48 males and 47 females) from the reference site. In general, fish sampled from Awba Dam were bigger than reference site. Sediment samples were also collected from both sites for contaminant analysis. Expression of ppar and cyp1 isoforms was analyzed using validated real-time PCR, while CYP1A and PPAR protein levels were analyzed using immunochemical method with specific antibodies. CYP-mediated catalytic responses (EROD, MROD and BROD) were performed by biochemical methods. We observed significant increases in ppar and cyp1 isoforms mRNA in both male and female fish from Awba Dam, compared to the reference site. Catalytic activities of EROD, MROD and BROD paralleled cyp1 transcript levels. Sex-related differences in PPAR and CYP1A protein levels were also observed, showing higher CYP1A proteins in males, compared with females, and higher PPAR proteins in females compared with males. Principal component analysis (PCA) biplot showed positive relationships between biological responses (ppar isoforms), condition factor (CF) and sediment PCBs, PAHs, OCPs and heavy metal concentrations. The present study shows that S. melanotheron inhabiting Awba Dam are severely affected by different classes of environmental contaminants that target metabolic processes (PPAR) and biotransformation pathways (CYP1A) in male and female fish, compared to a reference site. Interestingly, fish from Awba Dam were exhibiting good growth (evidence by high CF values) that paralleled increases in the transcriptional activation of ppar and cyp1 isoforms, despite the high

  19. Mercúrio total em pescado de água-doce Total mercury in fresh-water fish

    Directory of Open Access Journals (Sweden)

    Sandra Emi KITAHARA

    2000-08-01

    Full Text Available O mercúrio total foi quantificado em 11 espécies de peixes de água-doce, originárias de diferentes procedências comerciais. O mercúrio vem sendo utilizado na agricultura, indústria, mineração, etc., e isso tem provocado drástico aumento desse metal no meio ambiente, atingindo em conseqüência a cadeia trófica. Nesse contexto, o homem, através do consumo de alimentos, principalmente pescado, torna-se vulnerável à ação tóxica do mercúrio. Os resultados obtidos para as espécies mandi - Pimelodus maculatus, tilápia - Tilapia sp, sagüiru - Cyphocharax modestus, lambari - Astyanax sp, sardela - Triportheus sp, traíra - Hoplias sp, curimbatá - Prochilodus sp e dourado - Salminus sp, comercializadas em São Paulo - SP, e para o jaraqui - Semaprochilodus insignis, curimatã - Prochilodus nigricans e matrinchã - Brycon sp, procedentes da Amazônia brasileira, variaram de 0,01 a 0,39mgHg/Kg. Os resultados observados, sob o ponto-de-vista de Saúde Pública, estão abaixo dos limites de tolerância brasileiros, de 0,5 e 1,0mgHg/Kg, para espécies não-predadoras e predadoras, respectivamente. Nas espécies de hábito alimentar carnívoro (traíra e dourado os teores de mercúrio foram de 0,26 a 0,39mgHg/Kg. A expectativa de ocorrência de espécies excessivamente contaminadas não se confirmou.Total mercury was quantified in 11 fresh-water fish species from different commercial origins. Mercury has been used in agriculture, industry, mining, etc. Consequently there was an increase of mercury discharge to environment, that enters into the throphic chain. In this context, the man, through the consumption of foods, mainly fishery products, turns vulnerable to mercury. The obtained results for mandi - Pimelodus maculatus, tilápia - Tilapia sp, sagüiru - Cyphocharax modestus, lambari- Astyanax sp, sardela - Triportheus sp, traíra - Hoplias sp, curimbatá - Prochilodus sp and dourado - Salminus sp, commercialized in São Paulo-SP, and

  20. Dietary exposure to perfluoroalkyl acids of specific French adult sub-populations: high seafood consumers, high freshwater fish consumers and pregnant women.

    Science.gov (United States)

    Yamada, A; Bemrah, N; Veyrand, B; Pollono, C; Merlo, M; Desvignes, V; Sirot, V; Marchand, P; Berrebi, A; Cariou, R; Antignac, J P; Le Bizec, B; Leblanc, J C

    2014-09-01

    Perfluoroalkyl acids (PFAAs) are globally found in various media, including food and especially fishery products. In the present study, the dietary exposure to 15 perfluoroalkyl acids was assessed for 3 French adult populations, namely high seafood consumers, high freshwater fish consumers, and pregnant women. Purified food extracts were analysed by LC-MS/MS and PFBA, PFPA, PFHxA, PFHpA, PFOA, PFNA, PFDA, PFUnA, PFTrDA, PFTeDA, PFBS, PFHxS, PFHpS, PFOS and PFDS were monitored and quantified according to the isotope dilution principle. Under lower bound (LB) hypothesis (i.e. contamination valuesfreshwater fish consumers appear as the most exposed to PFOS (7.5 ng.kg(-1) bw.d(-1)), PFUnA (1.3 ng.kg(-1) bw.d(-1)), PFDA (0.4 ng.kg(-1) bw.d(-1)) and PFHpS (0.03 ng.kg(-1) bw.d(-1)) while high seafood consumers appear as the most exposed to PFOA (1.2 ng.kg(-1) bw.d(-1)), PFNA (0.2 ng.kg(-1) bw.d(-1)) and PFHxS (0.06 ng.kg(-1) bw.d(-1)). For all considered populations, the major exposure contributors are fish, seafood and water under LB hypothesis, while dairy products, bread and crispbread are the main contributors under upper bound (UB) hypothesis. Besides this food exposure assessment, further studies are needed to assess the more global PFAA exposure, taking into account indoor and outdoor air, dust and cutaneous contact, which could be other important contributors for this particular class of chemicals.

  1. On Manifestation Fields of Fish Culture%论鱼文化的表现领域

    Institute of Scientific and Technical Information of China (English)

    张岳林

    2000-01-01

    鱼类的自然属性一旦和人类相联系就有了社会属性,两者的结合即产生了鱼文化。鱼文化在我国的历史上及人们的饮食、风俗、美术等方面都有各种表现。在表现为各种生熟海鲜的同时反映出了鱼的馔食文化,在表现为各种鱼祭鱼信仰的同时演化出了鱼的风俗文化,在表现为各种图画造型的同时展现出了鱼的美术文化。探讨鱼文化的表现领域、规律属性等,对于挖掘民俗文化、建设和丰富人们的文化生活等,都有重要的文化史价值和现实意义。%Once associated with mankind,the natural property of fishes is charactisfic of social one.As a result of their integration fish culture universally comes into being.In the history of our country exist various manifestations about fish culture which can be found in diets,customs and even the fine arts and so on.These forms mirror fishes' food culture,custom culture and art culture while they exhibit kinds of rawcooked seafoods,fish sacrifices and fish convictions.Therefore,this paper aims at the research into the fields and regularities of activities of fish culture so that it has important cultural value and great significnce for tapping the culture of folk custom and enriching people's cultural life.

  2. Myxozoan pathogens of Malaysian fishes cultured in ponds and net-cages.

    Science.gov (United States)

    Székely, Cs; Shaharom-Harrison, F; Cech, G; Mohamed, K; Molnár, K

    2009-01-28

    We describe new myxosporean species from Malaysian fishes cultured in pond farms and net-cages. Myxobolus omari sp. nov. and M. leptobarbi sp. nov. were found in the muscles of Pangasianodon hypophthalmus and Leptobarbus hoevenii, respectively, while plasmodia and spores of Thelohanellus zahrahae sp. nov. and Henneguya daoudi sp. nov. were detected in the gills of Barbonymus gonionotus and Trichogaster trichopterus, respectively. Plasmodia and spores found in these fishes differed from the known myxosporean species in respect of their morphology, tissue tropism and 18S rDNA structure. No major pathological changes were found, but in the future these species might pose a potential threat to more intensified fish culture.

  3. In vitro culture of embryonic hearts from guppy fish (Poecilia reticulata )

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Forty embryonic hearts were taken out byanatomical needle from denuded embryos of the ovovivipar ity guppy fish that were dechorioned by mechanic method or by trypsin digestion, and were in vitro cultured. In the cul tured hearts, 80% have maintained beating in vitro for 4weeks, and the longest record for beating was 142 d. Owing to fish embryo transparency, beating frequency and blood color changes are easily viewed from the embryonic hearts under a dissecting microscope. The current study established the in vitro culture method of embryonic hearts in guppy fish,which can be used as a model for the study of heart and car diovascular system in vertebrates.

  4. Fish Culture Data - Characterization of Sexual Growth Dimorphism in Sablefish

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Sexual growth dimorphism (SGD) is a common phenomenon in nature. Numerous marine fishes exhibit SGD, with females often growing faster and attaining larger sizes...

  5. Fish Culture - North Puget Sound Chinook salmon captive propagation

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NOAA Fisheries is a cooperator with the Washington Department of Fish and Wildlife and the Lummi, Nooksack, and Stillaguamish Tribes in a 10-year program to rebuild...

  6. Development of a multi-locus sequence typing scheme for Laribacter hongkongensis, a novel bacterium associated with freshwater fish-borne gastroenteritis and traveler's diarrhea

    Directory of Open Access Journals (Sweden)

    Lee Edwin KY

    2009-01-01

    Full Text Available Abstract Background Laribacter hongkongensis is a newly discovered, facultative anaerobic, Gram-negative, motile, sea gull-shaped rod associated with freshwater fish borne gastroenteritis and traveler's diarrhea. A highly reproducible and discriminative typing system is essential for better understanding of the epidemiology of L. hongkongensis. In this study, a multilocus sequence typing (MLST system was developed for L. hongkongensis. The system was used to characterize 146 L. hongkongensis isolates, including 39 from humans and 107 from fish. Results Fragments (362 to 504 bp of seven housekeeping genes were amplified and sequenced. Among the 3068 bp of the seven loci, 332 polymorphic sites were observed. The median number of alleles at each locus was 34 [range 22 (ilvC to 45 (thiC]. All seven genes showed very low dn/ds ratios of ISA measurement showed significant linkage disequilibrium in isolates from both humans and fish. The ISA for the isolates from humans and fish were 0.270 and 0.636, indicating the isolates from fish were more clonal than the isolates from humans. Only one interconnected network (acnB was detected in the split graphs. The P-value (P = 0 of sum of the squares of condensed fragments in Sawyer's test showed evidence of intragenic recombination in the rho, acnB and thiC loci, but the P-value (P = 1 of maximum condensed fragment in these gene loci did not show evidence of intragenic recombination. Congruence analysis showed that all the pairwise comparisons of the 7 MLST loci were incongruent, indicating that recombination played a substantial role in the evolution of L. hongkongensis. A website for L. hongkongensis MLST was set up and can be accessed at http://mlstdb.hku.hk:14206/MLST_index.html. Conclusion A highly reproducible and discriminative MLST system was developed for L. hongkongensis.

  7. Effects of sodium sulfate on the freshwater microalga Chlamydomonas moewusii: implications for the optimization of algal culture media.

    Science.gov (United States)

    Mera, Roi; Torres, Enrique; Abalde, Julio

    2016-02-01

    The study of the microalgal growth kinetics is an indispensable tool in all fields of phycology. Knowing the optimal nutrient concentration is an important issue that will help to develop efficient growth systems for these microorganisms. Although nitrogen and phosphorus are well studied for this purpose, sulfur seems to be less investigated. Sulfate is a primary sulfur source used by microalgae; moreover, the concentration of this compound is increasing in freshwater systems due to pollution. The aim of this study was to investigate the effects of different sodium sulfate concentrations in the culture medium on growth and growth kinetics of the freshwater microalga Chlamydomonas moewusii. Production of biomass, chl content, kinetic equations, and a mathematical model that describe the microalgal growth in relation with the concentration of sodium sulfate were obtained. The lowest concentration of sodium sulfate allowing optimal growth was 0.1 mM. Concentrations higher than 3 mM generated a toxic effect. This work demonstrates that this toxic effect was not directly due to the excess of sulfate ion but by the elevation of the ionic strength. An inhibition model was successfully used to simulate the relationship between specific growth rate and sodium sulfate in this microalga.

  8. Records of the bird capillariid nematode Ornithocapillaria appendiculata (Freitas, 1933) n. comb. from freshwater fishes in Mexico, with remarks on Capillaria patzcuarensis Osorio-Sarabia et al., 1986.

    Science.gov (United States)

    Moravec, F; Salgado-Maldonado, G; Osorio-Sarabia, D

    2000-01-01

    Re-examination of capillariid specimens collected from the freshwater fish Chirostoma estor Jordan from Lake Pátzcuaro in 1985-1986 and deposited as paratypes of Capillaria patzcuarensis Osorio-Sarabia, Pérez-Ponce de León & Salgado-Maldonado, 1986 showed that their morphology was in contradiction with the description of this species and, in fact, they could be identified as the species originally described as C. appendiculata Freitas, 1933 from cormorants Phalacrocorax brasilianus (Gm.) in Brazil; conspecific capillariid specimens were later recorded from Chirostoma estor and Cyprinus carpio L. from the same locality. This species and two others are transferred to Ornithocapillaria Barus & Sergeeva, 1990 as O. appendiculata (Freitas, 1933) n. comb., O. carbonis (Dubinin & Dubinina, 1940) n. comb., and O. phalacrocoraxi (Borgarenko, 1975) n. comb. This is the first record of O. appendiculata in Mexico. Its occurrence in fishes suggests that these nematodes may be acquired by their fish hosts accidentally while feeding on cormorant excrement containing mature nematodes. A female capillariid collected from one of 110 Chirostoma estor examined from this locality in April, 1998 was identified as Capillaria patzcuarensis. Both capillariid species are briefly described and illustrated.

  9. Fluorescence in situ hybridization and sequential catalysed reporter deposition (2C-FISH for the flow cytometric sorting of freshwater ultramicrobacteria

    Directory of Open Access Journals (Sweden)

    Stefan M Neuenschwander

    2015-03-01

    Full Text Available Flow cytometric sorting is a powerful tool to physically separate cells within mixed microbial communities. If combined with phylogenetic staining (fluorescence in situ hybridization, FISH it allows to specifically sort defined genotypic microbial populations from complex natural samples. However, the targeted enrichment of freshwater ultramicrobacteria, such as members of the LD12 clade of Alphaproteobacteria (SAR11-IIIb, is still challenging. Current FISH protocols, even in combination with signal amplification by catalysed reporter deposition (CARD, are not sufficiently sensitive for the distinction of these bacteria from background noise by flow cytometry, presumably due to their low ribosome content and small cell sizes. We, therefore, modified a CARD based flow sorting protocol with the aim of increasing its sensitivity to a level sufficient for ultramicrobacteria. This was achieved by a second signal amplification step mediated by horseradish peroxidase labelled antibodies targeted to the fluorophores that were previously deposited by CARD-FISH staining. The protocol was tested on samples from an oligo-mesotrophic lake. Ultramicrobacteria affiliated with LD12 Alphaproteobacteria could be successfully sorted to high purity by flow cytometry. The ratios of median fluorescence signal to background ranged around 20, and hybridization rates determined by flow cytometry were comparable to those obtained by fluorescence microscopy. Potential downstream applications of our modified cell staining approach range from the analysis of microdiversity within 16S rRNA-defined populations to that of functional properties, such as the taxon-specific incorporation rates of organic substrates.

  10. Thermal and maternal environments shape the value of early hatching in a natural population of a strongly cannibalistic freshwater fish

    DEFF Research Database (Denmark)

    Pagel, T.; Bekkevold, Dorte; Pohlmeier, S.;

    2015-01-01

    Hatching early in the season is often assumed to elevate fitness, particularly in cannibalistic fish in which size-dependent predation mortality is a major selective force. While the importance of the thermal environment for the growth of fish is undisputed, the relevance of maternal effects...

  11. Composite fish culture for mosquito control in rice fields in southern India.

    Science.gov (United States)

    Victor, T J; Chandrasekaran, B; Reuben, R

    1994-09-01

    Composite culture of edible fishes (common carp, Cryprinus carpio; silver carp, Hypopthalmithys molitrix, grass carp, Ctenopharyngodon idella; catla, Catla catla; rohu, Labeo rohita; and mrigal, Cirrhinus mrigala) in rice fields in the Cauvery delta of Tamil Nadu, southern India, resulted in 81.0% reduction in the immature mosquito population of anophelines and 83.5% of culicines. Analysis of fish feces for mosquito larval head capsules showed that common carp and silver carp are effective larvivores. The selective feeding of common carp on culicines and silver carp on anophelines is correlated to their trophic niches. Net profit in the fish-cum-rice fields was 2.5 times greater than fields in which rice alone was cultured. Hence, rice-cum-fish culture can be recommended to the farming community in this area.

  12. Studies on the Developmental Potentiality of Cultured Cell Nuclei of Fish

    Directory of Open Access Journals (Sweden)

    Hongxi Chen, Yonglan Yi, Minrong Chen, Xingqi Yang

    2010-01-01

    Full Text Available By means of the serial nuclear transplantation technique, the authors obtained a nuclear transplant fish from subcultured cell originated from the blastula cells of the crucian carp (Carassius auratus Linnaeus. This nuclear transplant fish survived for three years, but its sexual glands were undifferentiated. The authors have also obtained a sexually mature adult fish from short-term cultured kidney cell nucleus of an adult crucian carp. Results of the experiment implied that the subcultured cell nuclei of fish blastula cells and the specialized somatic cell nuclei of adult fish still retained their developmental totipotency, and thus, it indicated that there is a possibility of fish somatic cell breeding through the use of nuclear transplantation.

  13. Suitability of magnetic particle immunoassay for the analysis of PBDEs in Hawaiian freshwater fish and crabs in comparison with gas chromatography/electron capture detection-ion trap mass spectrometry

    Science.gov (United States)

    A gas chromatograph/electron capture detector-ion trap mass spectrometer (GC/ECD-ITMS) was used for the determination of polybrominated diphenyl ethers (PBDEs) in freshwater fish and crabs. The samples were also analyzed with an enzyme-linked immunosorbent assay (ELISA). GC/ECD-ITMS results showed...

  14. Environmental management of marine fish culture in Hong Kong.

    Science.gov (United States)

    Lee, J H W; Choi, K W; Arega, F

    2003-01-01

    Marine fish farming is an important commercial practice in Hong Kong. Marine fish farms located in eutrophic coastal waters often face the threat of severe dissolved oxygen depletion associated with algal blooms and red tides. On the other hand, mariculture activities also contribute to pollution. The sustainable management of mariculture requires proper siting of the fish farms and stocking density control. Both of these are related to the carrying capacity of the water body concerned, which is mainly governed by its flushing characteristics. A simple method to determine the carrying capacity of a fish farm has been developed by using three-dimensional (3D) hydrodynamic modelling and its effective coupling with a diagenetic water quality model. A systematic methodology using numerical tracer experiments has been developed to compute the tidal flushing in a fish farm. The flushing time is determined from the results of a numerical tracer experiment using robust 3D hydrodynamic and mass transport models. A unit tracer concentration is initially prescribed inside the region of interest and zero elsewhere; the subsequent mass transport and the mass removal process are then tracked. The fish farms are usually situated in well-sheltered shallow embayments and may not connect directly to the open water. It is found that it is necessary to define both "local" and "system-wide" flushing times to represent the effectiveness of the mass exchange with the surrounding water body and the open sea respectively. A diagenetic water quality model simulating the sediment-water-pollutant interaction is employed to address the response of the water column and the benthic layer to pollution discharges. With the flushing rate reliably computed, the carrying capacity of the fish farm can be determined in terms of key water quality parameters: chlorophyll-a, dissolved oxygen, organic nitrogen and potential lowest dissolved oxygen level on a day of negligible photosynthetic production. The

  15. A new species of Hedruris Nitzsch, 1821 (Nematoda: Hedruridae) parasitic in the freshwater fish Oligosarcus jenynsii (Günther, 1864) (Characidae) from Argentina.

    Science.gov (United States)

    Rossin, María Alejandra; Timi, Juan Tomás

    2016-11-01

    Nematodes belonging to genus Hedruris Nitzsch, 1821 (Nematoda: Hedruridae) were found in the stomach of the freshwater fish Oligosarcus jenynsii (Günther, 1864) (Characidae) from a shallow eutrophic lake in Argentina. Morphological comparisons with congeneric relatives showed that these nematodes belong to a new species, for which H. bifida n. sp. is proposed. Hedruris bifida n. sp. can be distinguished from its congeners by the following combination of characters: bifid deirids, absence of precloacal papillae and nine pairs of postcloacal papillae and non-mammillated eggs. The new species closely resembles Hedruris suttonae Brugni & Viozzi, 2010¸ the only known species from Argentina; however, the bifid deirids in the new species and the distribution pattern of perianal spines in females clearly distinguish both species. Hedruris bifida n. sp. represents the second nominal species of the genus in Argentina and the eighth species described in the Neotropical region.

  16. How does diet influence the reproductive seasonality of tropical freshwater fish?: A case study of a characin in a tropical mountain river

    Directory of Open Access Journals (Sweden)

    Tania M. Ballesteros

    Full Text Available Seasonal breeding of tropical freshwater fish may be synchronized with periods of high food consumption. We explored this hypothesis by studying the relationship between diet and reproductive activity of Creagrutus guanes (Teleostei, Characidae. Our results showed that C. guanes had a generalist and omnivorous diet dominated by aquatic insects (mainly Diptera larvae and seeds. Creagrutus guanes did not show intersexual or ontogenetic variation in diet. Peaks of feeding activity during rainy months were not synchronized with breeding in dry months. Our results do not support the hypothesis that the reproductive season has to be synchronized with high food consumption. We discussed the hypothesis fat reserves may be an important factor for the desynchronization of peaks of feeding and reproduction as explanation of seasonal breeding of this species.

  17. Magnesium status in freshwater fish, common carp (Cyprinus carpio, L.) and the dietary protein-magnesium interaction.

    Science.gov (United States)

    Dabrowska, H; Meyer-Burgdorff, K H; Gunther, K D

    1991-04-01

    Common carp juveniles were fed for 9 weeks one of the eight semipurified diets containing graded levels of magnesium, 0.08, 0.6, 1.1, 3, 2 g Mg kg(-1) and 25 or 44% protein.Fish growth and feed utilization were significantly affected by both Mg and protein levels in the diets. Significant interaction between these two studied variables existed in relation to the fish performance as well as to mean deposition rate of several minerals in common carp body. The fish fed diets containing 0.08 g Mg kg(-1) had reduced growth and developed deficiency signs such as muscle flaccidity and skin hemorrhages.Results indicated that a minimum Mg level of 0.6 g Mg kg(-1) was required to elevate plasma and bone magnesium content and to reduce the whole body Ca concentration (hypercalcinosis symptom). Further increase of dietary Mg up to 3.2 g Mg kg(-1) improved growth rate of fish insignificantly, but the deposition rate of dietary Mg fell to as low as 7.4 and 10.7 percent in low- and high-protein diet fed fish, respectively. In Mg-deficient fish, considerable amount of magnesium was absorbed via extra-oral routes, however, this way of the covering magnesium need becomes insufficient in fast growing fish.

  18. Water quality, welfare and pathology of fish cultured in sport fishing lakes and ponds from Romania

    OpenAIRE

    Cristin Borda; Silvana Popescu; Anca Boaru; Cristina I. El Mahdy

    2013-01-01

    Fish welfare and their health depend on a large extent on the water quality where they live.Variation in physical, chemical or biological characteristics, in limits too high or very short time,represent serious stress factors for fish. Stress factors reduce the animal’s overall resistance to pestsand diseases and increase the virulence of some pathogenic biotic agents or conditioned pathogens.This research has proposed emphasizing the impact of medial water parameters situated at the limit of...

  19. Role of mangroves in brackish water fish culture

    Digital Repository Service at National Institute of Oceanography (India)

    Wafar, S.

    very obvious that any kind of damage or destruction for mangroves may affect the capture or culture fishery resources. Aquaculture development is recently becoming the more fashionable landuse of mangroves. Prawn culture is being practiced throughout...

  20. Effect of culture season and stocking density on the growth and production of giant freshwater prawn (Macrobrachium rosenbergii de Ma raised in northern Thailand

    Directory of Open Access Journals (Sweden)

    Rodrigo P. Baysa

    2007-12-01

    Full Text Available This study evaluated the effects of culture season and different stocking density on productivity of freshwater prawn that was raised in northern Thailand. The experiment was conducted at the Faculty of Fisheries Technology and Aquatic Resources, Maejo University, Chiang Mai, Thailand. This study was divided into two experiments; each treatment was replicated three times. The first experiment investigated the effect of climatic condition on the culture and production of freshwater prawn post larvae (PL 10; mean weight of 0.02 g stocked in 400m2 ponds. Results of the first experiment revealed freshwater prawn raised during the dry season to summer obtained higher growth rate (0.19 g and 0.15 g/day and survival rate (34.27% and 24.49% than that of summer to rainy season (p<0.05. The second experiment investigated the effect of 2 different socking densities (25 and 50 individuals/m2 on the production survival of freshwater prawn. Results showed that the rate of growth, survival rate, and production, were much higher at a stocking density of 25 individuals/m2 (p<0.05 in contrast to 50 individuals/m2. Growth performances of freshwater prawns were triggered by stocking density and season.

  1. A Comparative Study of the Influence of Energy Level in the Fillet and Food Intake of Economically Important Marine-and-Freshwater Fish Species from Saudi Arabia

    Directory of Open Access Journals (Sweden)

    Mohd. Javed Kamal Shamsi

    2014-11-01

    Full Text Available Energy content interms of calories/ gram dry weight in the fillet as well as in the food as the dietary ratio of some economically important fishes from different habitat (Marine and freshwater were determined by two methods; The Organic Carbon and The Karzinkin Tarkovaskaya. The energy value of the nutrients in the fillet/food was determined by these two methods which were highly significant (p<0.001 and in order [Rastrillegar kanagurta(988.50/8251.66 and 12088.28/8694.46 Joules gm-1; Lethrinus lentjan (7274.80/ 5544.50 and 9237.30/ 5978.26 Joules gm-1; Aphareus rutilans (6891.56/ 4813.56 and 9092 58/ 5136.78 Joules gm-1 and Chanos chanos (6681.50/ 5120.56 and 8841.48/ 5520.54 Joules gm-1] in Marine water fishes. As compare to other environment of freshwater, the order was as such, Clarius gariepinus (7888.61/6613.83 and 8779.25/7290.40 Joules gm-1 Oreochromis niloticus (6103.00/4778.69 and 6896.20/5584.16 Joules gm-1; Cyprinus carpio (5639.38/4276.49 and 6370.41/4942.18 Joules gm-1 and Gara tibanica (4353. 22/3300.45 and 3882.73/2680.53 Joules gm-1 respectively. The moisture content and the ratio of energetic values of fillet/food were also determined and tabulated. Consistency of the results obtained indicate the reliability of the method used and to explain the validity of conversion factor from weight to energy which will be useful for general estimation of energy contents and energy flow in aquatic ecosystem.

  2. Testing for shared biogeographic history in the lower Central American freshwater fish assemblage using comparative phylogeography: concerted, independent, or multiple evolutionary responses?

    Science.gov (United States)

    Bagley, Justin C; Johnson, Jerald B

    2014-05-01

    A central goal of comparative phylogeography is determining whether codistributed species experienced (1) concerted evolutionary responses to past geological and climatic events, indicated by congruent spatial and temporal patterns ("concerted-response hypothesis"); (2) independent responses, indicated by spatial incongruence ("independent-response hypothesis"); or (3) multiple responses ("multiple-response hypothesis"), indicated by spatial congruence but temporal incongruence ("pseudocongruence") or spatial and temporal incongruence ("pseudoincongruence"). We tested these competing hypotheses using DNA sequence data from three livebearing fish species codistributed in the Nicaraguan depression of Central America (Alfaro cultratus, Poecilia gillii, and Xenophallus umbratilis) that we predicted might display congruent responses due to co-occurrence in identical freshwater drainages. Spatial analyses recovered different subdivisions of genetic structure for each species, despite shared finer-scale breaks in northwestern Costa Rica (also supported by phylogenetic results). Isolation-with-migration models estimated incongruent timelines of among-region divergences, with A. cultratus and Xenophallus populations diverging over Miocene-mid-Pleistocene while P. gillii populations diverged over mid-late Pleistocene. Approximate Bayesian computation also lent substantial support to multiple discrete divergences over a model of simultaneous divergence across shared spatial breaks (e.g., Bayes factor [B 10] = 4.303 for Ψ [no. of divergences] > 1 vs. Ψ = 1). Thus, the data support phylogeographic pseudoincongruence consistent with the multiple-response hypothesis. Model comparisons also indicated incongruence in historical demography, for example, support for intraspecific late Pleistocene population growth was unique to P. gillii, despite evidence for finer-scale population expansions in the other taxa. Empirical tests for phylogeographic congruence indicate that multiple

  3. Study on the Heat Pump Drying of the Freshwater Fish%淡水鱼热泵干燥工艺研究

    Institute of Scientific and Technical Information of China (English)

    顾震; 徐刚; 张森旺; 徐建国

    2012-01-01

    以淡水鱼为原料,研究分析预处理工艺、干燥室内风速、干燥室内风温对干燥时间、产品的TVBN值和产品复水性的影响。确定了适合淡水鱼片热泵干燥的工艺参数为:新鲜鱼片,干燥室内风速1.0 m/s,风温50℃。在该工艺条件下干燥的鱼片干制品复水性好,感官评定好,新鲜度好,属于一级品,并且具有干燥时间短的优点。%This used the freshwater fish as raw material.The effects of the dry time,the product’s re-hydration and the TVBN value were studied and analyzed on the pretreatment craft,the wind speed of drying chamber and the wind temperature of drying chamber.The result showed the optimum parameter of the heat pump drying: The fillet of freshwater fish,the wind speed was 1.0 m/s in the drying chamber and the wind temperature was 50 ℃.Under the technique conditions,the re-hydration of the fillet product was good,the TVBN value was small and belonged to the primes,the dry time was short and the organoleptic investigation was good.

  4. Identification of major allergens from four kinds of freshwater fishes%四种淡水鱼致敏蛋白免疫原性研究

    Institute of Scientific and Technical Information of China (English)

    刘楚怡; 刘蓉; 薛文通; 张惠

    2011-01-01

    Aiming to investigate the major allergens of the following four kinds of freshwater fishes,Grass carp(Ctenopharyngodon idellus),Snakehead(Ophicephalus argus),Catfish(Silurus asotus)and Japanese sea perch(Lateolabrax japonicus)were studied.Fish muscle was extracted in the same volume of coca's buffer(pH 8.3).The relative contents of major allergens were quantified by SDS-PAGE densitometry.Immunoblot on the four kinds of freshwater fish protein extracts were performed with sera from 12 eczema patients with serum specific immunoglobulin E of fish proteins.In result,the major allergen of Grass carp was 107,62,50,27ku protein.There were 6 major allergic protein of Snakehead which were 62,50,34,32,28,17ku.The positive protein which were connected with the specific immunoglobulin E of Catfish were 62,50,39,37ku protein.Japanese sea perch major allergen were 62,50,37,34,32,18ku protein.%对常见的食物过敏原,草鱼(Ctenopharyngodon idellus)、乌鳢(Ophicephalus argus)、鲇鱼(Silurus asotus)、花鲈(Lateolabrax japonicus)四种淡水鱼进行了特异性抗原的识别,通过coca’s缓冲液分别于四类鱼肌肉组织中提取蛋白粗提液,经SDS-PAGE分离出多种分子量不同的蛋白组分并对其进行分析,再通过Western-blotting识别四种淡水鱼过敏原研究其免疫原性。由SDS-PAGE电泳分别得到四种淡水鱼全蛋白电泳图,通过免疫印迹等方法发现草鱼与IgE结合的阳性带主要有4条(107、62、50、27ku),乌鳢与IgE结合的阳性带主要有6条(62、50、34、32、28、17ku),鲇鱼与IgE结合的阳性带主要有4条(62、50、39、37ku),花鲈与IgE结合的阳性带主要有6条(62、50、37、34、32、18ku)。

  5. Dietary exposure to perfluoroalkyl acids of specific French adult sub-populations: High seafood consumers, high freshwater fish consumers and pregnant women

    Energy Technology Data Exchange (ETDEWEB)

    Yamada, A., E-mail: ami.s.yamada@gmail.com [Risk Assessment Directorate, French Agency for Food, Environmental and Occupational Health and Safety (ANSES), 27-31 avenue du Général Leclerc, Maisons-Alfort 94701 (France); Bemrah, N., E-mail: nawel.bemrah@anses.fr [Risk Assessment Directorate, French Agency for Food, Environmental and Occupational Health and Safety (ANSES), 27-31 avenue du Général Leclerc, Maisons-Alfort 94701 (France); Veyrand, B., E-mail: bruno.veyrand@oniris-nantes.fr [LUNAM Université, Oniris, Laboratoire d' Etude des Résidus et Contaminants dans les Aliments (LABERCA), USC INRA 1329, Nantes 44307 (France); Pollono, C., E-mail: charles.pollono@oniris-nantes.fr [LUNAM Université, Oniris, Laboratoire d' Etude des Résidus et Contaminants dans les Aliments (LABERCA), USC INRA 1329, Nantes 44307 (France); Merlo, M., E-mail: mathilde.merlo@anses.fr [Risk Assessment Directorate, French Agency for Food, Environmental and Occupational Health and Safety (ANSES), 27-31 avenue du Général Leclerc, Maisons-Alfort 94701 (France); Desvignes, V., E-mail: virginie.desvignes@anses.fr [Risk Assessment Directorate, French Agency for Food, Environmental and Occupational Health and Safety (ANSES), 27-31 avenue du Général Leclerc, Maisons-Alfort 94701 (France); Sirot, V., E-mail: sirotv@gmail.com [Risk Assessment Directorate, French Agency for Food, Environmental and Occupational Health and Safety (ANSES), 27-31 avenue du Général Leclerc, Maisons-Alfort 94701 (France); and others

    2014-09-01

    Perfluoroalkyl acids (PFAAs) are globally found in various media, including food and especially fishery products. In the present study, the dietary exposure to 15 perfluoroalkyl acids was assessed for 3 French adult populations, namely high seafood consumers, high freshwater fish consumers, and pregnant women. Purified food extracts were analysed by LC–MS/MS and PFBA, PFPA, PFHxA, PFHpA, PFOA, PFNA, PFDA, PFUnA, PFTrDA, PFTeDA, PFBS, PFHxS, PFHpS, PFOS and PFDS were monitored and quantified according to the isotope dilution principle. Under lower bound (LB) hypothesis (i.e. contamination values < LOD considered as 0), high freshwater fish consumers appear as the most exposed to PFOS (7.5 ng.kg{sup −1} bw.d{sup −1}), PFUnA (1.3 ng.kg{sup −1} bw.d{sup −1}), PFDA (0.4 ng.kg{sup −1} bw.d{sup −1}) and PFHpS (0.03 ng.kg{sup −1} bw.d{sup −1}) while high seafood consumers appear as the most exposed to PFOA (1.2 ng.kg{sup −1} bw.d{sup −1}), PFNA (0.2 ng.kg{sup −1} bw.d{sup −1}) and PFHxS (0.06 ng.kg{sup −1} bw.d{sup −1}). For all considered populations, the major exposure contributors are fish, seafood and water under LB hypothesis, while dairy products, bread and crispbread are the main contributors under upper bound (UB) hypothesis. Besides this food exposure assessment, further studies are needed to assess the more global PFAA exposure, taking into account indoor and outdoor air, dust and cutaneous contact, which could be other important contributors for this particular class of chemicals. - Highlights: • The dietary exposure was estimated for 15 perfluoroalkyl acids. • Despite the overestimation, the FFQ remains useful to evaluate the whole diet. • The high fish consumers are the most dietary exposed population. • Fishery products are the main exposure contributors under LB hypothesis.

  6. Geographical origin of Amazonian freshwater fishes fingerprinted by ⁸⁷Sr/⁸⁶Sr ratios on fish otoliths and scales.

    Science.gov (United States)

    Pouilly, Marc; Point, David; Sondag, Francis; Henry, Manuel; Santos, Roberto V

    2014-08-19

    Calcified structures such as otoliths and scales grow continuously throughout the lifetime of fishes. The geochemical variations present in these biogenic structures are particularly relevant for studying fish migration and origin. In order to investigate the potential of the (87)Sr/(86)Sr ratio as a precise biogeochemical tag in Amazonian fishes, we compared this ratio between the water and fish otoliths and scales of two commercial fish species, Hoplias malabaricus and Schizodon fasciatus, from three major drainage basins of the Amazon: the Madeira, Solimões, and Tapajós rivers, displaying contrasted (87)Sr/(86)Sr ratios. A comparison of the (87)Sr/(86)Sr ratios between the otoliths and scales of the same individuals revealed similar values and were very close to the Sr isotopic composition of the local river where they were captured. This indicates, first, the absence of Sr isotopic fractionation during biological uptake and incorporation into calcified structures and, second, that scales may represent an interesting nonlethal alternative for (87)Sr/(86)Sr ratio measurements in comparison to otoliths. Considering the wide range of (87)Sr/(86)Sr variations that exist across Amazonian rivers, we used variations of (87)Sr/(86)Sr to discriminate fish origin at the basin level, as well as at the sub-basin level between the river and savannah lakes of the Beni River (Madeira basin).

  7. Investigation and traceability of residual malachite green and its metabolite in freshwater fish%养殖鱼孔雀石绿及其代谢物残留量的调查与溯源

    Institute of Scientific and Technical Information of China (English)

    傅武胜; 郑奎城; 邱文倩; 王琪林; 方勤美

    2013-01-01

    Objective To monitor and assess the residues of malachite green (MG) and its metabolite leuco-malachite green (LMG) in freshwater fish from Fujian and Guangdong provinces. And to carry out the residual traceability of MG for finding the main reasons of high percentage of MG in Chinese perch. Methods A total of 16 kinds of 66 fish samples and 26 water samples were collected from the retailers in Fujian and Guangdong province. After samples being homogenized and pretreated, the concentration of total MG in sam-ples was quantified by high pressure liquid chromatography (HPLC) coupled with fluorescence detector. The MG positive samples analyzed by HPLC were confirmed by HPLC-mass spectrometer (LC-MS/MS). Results The detection rate of MG was 56.1%(37/66) with levels ranged from 0.50 to 148μg/kg in samples. MG was detected in 75.8% (25/33) of Chinese perch. The detection rate of MG (53.3%~60.0%) was very similar in freshwater fish sold in Fujian and Guangdong in the retailer. Conclusion High percentage of MG was found in freshwater fish from Fujian and Guangdong province. And no MG was found in water sample from the same cultured pool in the markets. It is indicated that the illegal application of MG in supply chains for Chinese perch may be in the cultivation rather than in the long store and wholesale.%  目的了解福建与广东两省水产批发市场养殖鱼孔雀石绿(MG)及其代谢物的残留情况;并通过水产批发市场活鱼以及暂养水中MG测定,对养殖鱼MG污染情况进行溯源分析,初步推测养殖鱼MG残留的原因,为有效遏制MG滥用提供科学依据.方法16个品种的66份鲜活养殖鱼分别购自福建、广东两省的3个水产批发市场,制作成鱼肉浆;来自同一市场的26份水样均为桂花鱼的暂养水;样品经前处理后,采用高压液相色谱-荧光法检测MG及其代谢物LMG的残留总量.结果检出MG的样品占56.1%(37/66),桂花鱼MG检出率最高(75.8%),

  8. A pilot study to conduct a freshwater fish inventory of small tundra ponds on the Bristol Bay Coastal Plain, Alaska

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — State-owned lands on the Bristol Bay coastal plain in southwest Alaska have been opened for oil and gas exploration. This area encompasses numerous small lakes and...

  9. In vivo and in vitro exposures for the evaluation of the genotoxic effects of lead on the Neotropical freshwater fish Prochilodus lineatus

    Energy Technology Data Exchange (ETDEWEB)

    Monteiro, V.; Cavalcante, D.G.S.M.; Vilela, M.B.F.A. [Laboratory of Animal Ecophysiology, Department of Physiological Sciences, Londrina State University, PB 6001, 86051-990 Londrina, PR (Brazil); Sofia, S.H. [Laboratory of Genetics and Animal Ecology, Department of General Biology, Londrina State University, PB 6001, 86051-990 Londrina, PR (Brazil); Martinez, C.B.R., E-mail: cbueno@uel.br [Laboratory of Animal Ecophysiology, Department of Physiological Sciences, Londrina State University, PB 6001, 86051-990 Londrina, PR (Brazil)

    2011-08-15

    In the present study, in vivo and in vitro exposures were used to assess the genotoxicity of lead (Pb) to the freshwater fish Prochilodus lineatus. The comet assay using blood, liver and gill cells, and the occurrence of micronuclei (MN) and other erythrocytic nuclear abnormalities (ENA) were used to assess the genotoxic potential of lead in vivo. Metallothionein content (MT) was measured in fish liver in order to evaluate the protection of fish against Pb toxicity. Fish erythrocytes were exposed to Pb in vitro (1, 3 and 6 h) and the number of viable cells, DNA integrity, using the comet assay, and lysosomal membrane stability, measured by the neutral red retention assay (NRRA) were analyzed. The results of the comet assay after in vivo toxicity tests (6, 24 and 96 h) showed that Pb was genotoxic for all the three tissues analyzed after 96 h exposure. A significant increase in liver MT content was observed after 6 and 24 h of Pb exposure. MN frequency did not increase after Pb exposures, but the frequency of the other ENA, such as kidney-shaped nuclei, segmented nuclei and lobed nuclei, showed a significant increase after 24 and 96 h, indicating that ENA is a better biomarker for Pb exposure than MN alone after short-term exposures. The results of the comet assay performed with erythrocytes in vitro exposed to lead confirmed its genotoxic effect and showed that DNA damage increased with increasing exposure time. Moreover, the NRRA clearly indicated that Pb induces a destabilization of the lysosomal membrane. These results demonstrate the potential genotoxicity and cytotoxicity of lead after acute exposures.

  10. In vivo and in vitro exposures for the evaluation of the genotoxic effects of lead on the Neotropical freshwater fish Prochilodus lineatus.

    Science.gov (United States)

    Monteiro, V; Cavalcante, D G S M; Viléla, M B F A; Sofia, S H; Martinez, C B R

    2011-08-01

    In the present study, in vivo and in vitro exposures were used to assess the genotoxicity of lead (Pb) to the freshwater fish Prochilodus lineatus. The comet assay using blood, liver and gill cells, and the occurrence of micronuclei (MN) and other erythrocytic nuclear abnormalities (ENA) were used to assess the genotoxic potential of lead in vivo. Metallothionein content (MT) was measured in fish liver in order to evaluate the protection of fish against Pb toxicity. Fish erythrocytes were exposed to Pb in vitro (1, 3 and 6 h) and the number of viable cells, DNA integrity, using the comet assay, and lysosomal membrane stability, measured by the neutral red retention assay (NRRA) were analyzed. The results of the comet assay after in vivo toxicity tests (6, 24 and 96 h) showed that Pb was genotoxic for all the three tissues analyzed after 96 h exposure. A significant increase in liver MT content was observed after 6 and 24 h of Pb exposure. MN frequency did not increase after Pb exposures, but the frequency of the other ENA, such as kidney-shaped nuclei, segmented nuclei and lobed nuclei, showed a significant increase after 24 and 96 h, indicating that ENA is a better biomarker for Pb exposure than MN alone after short-term exposures. The results of the comet assay performed with erythrocytes in vitro exposed to lead confirmed its genotoxic effect and showed that DNA damage increased with increasing exposure time. Moreover, the NRRA clearly indicated that Pb induces a destabilization of the lysosomal membrane. These results demonstrate the potential genotoxicity and cytotoxicity of lead after acute exposures.

  11. De novo genome assembly and annotation of Australia's largest freshwater fish, the Murray cod (Maccullochella peelii), from Illumina and Nanopore sequencing read.

    Science.gov (United States)

    Austin, Christopher M; Tan, Mun Hua; Harrisson, Katherine A; Lee, Yin Peng; Croft, Laurence J; Sunnucks, Paul; Pavlova, Alexandra; Gan, Han Ming

    2017-08-01

    One of the most iconic Australian fish is the Murray cod, Maccullochella peelii (Mitchell 1838), a freshwater species that can grow to ∼1.8 metres in length and live to age ≥48 years. The Murray cod is of a conservation concern as a result of strong population contractions, but it is also popular for recreational fishing and is of growing aquaculture interest. In this study, we report the whole genome sequence of the Murray cod to support ongoing population genetics, conservation, and management research, as well as to better understand the evolutionary ecology and history of the species. A draft Murray cod genome of 633 Mbp (N50 = 109 974bp; BUSCO and CEGMA completeness of 94.2% and 91.9%, respectively) with an estimated 148 Mbp of putative repetitive sequences was assembled from the combined sequencing data of 2 fish individuals with an identical maternal lineage; 47.2 Gb of Illumina HiSeq data and 804 Mb of Nanopore data were generated from the first individual while 23.2 Gb of Illumina MiSeq data were generated from the second individual. The inclusion of Nanopore reads for scaffolding followed by subsequent gap-closing using Illumina data led to a 29% reduction in the number of scaffolds and a 55% and 54% increase in the scaffold and contig N50, respectively. We also report the first transcriptome of Murray cod that was subsequently used to annotate the Murray cod genome, leading to the identification of 26 539 protein-coding genes. We present the whole genome of the Murray cod and anticipate this will be a catalyst for a range of genetic, genomic, and phylogenetic studies of the Murray cod and more generally other fish species of the Percichthydae family. © The Authors 2017. Published by Oxford University Press.

  12. Application of FISK, an invasiveness screening tool for non-native freshwater fishes, in the Murray-Darling Basin (southeastern Australia).

    Science.gov (United States)

    Vilizzi, Lorenzo; Copp, Gordon H

    2013-08-01

    The Fish Invasiveness Scoring Kit (FISK) is currently one of the most popular pre-screening tools for freshwater fishes. A recent upgrade has ensured its wider climatic relevance to countries with subtropical regions. This enhancement is of particular importance to Australia, which encompasses tropical, arid, and temperate zones, and where the introduction of non-native fish species poses a significant risk to biodiversity. In this study, 55 fish species previously evaluated in a U.K.-based calibration of FISK are reassessed for their potential invasiveness in the Murray-Darling Basin (MDB; southeastern Australia), the continent's largest catchment encompassing arid and temperate climates. Approximately half of the species were classed as "medium risk" and the other half as "high risk," and the ≥19 threshold previously identified from the calibration study was confirmed. The three highest scoring species (common carp Cyprinus carpio carpio, goldfish Carassius auratus, and eastern mosquitofish Gambusia holbrooki) were those already present and invasive in the area, whereas nearly half of the tropical and subtropical species had lower scores compared to U.K. assessments, possibly because of climate change predictions of drier conditions across the MDB. There were some discordances between FISK and two Australian-based assessment protocols, one of which is qualitative and the other represents a simplified version of FISK. Notably, the Australian origins of FISK should provide for an additional reason for further applications of the tool in other RA areas (i.e., drainage basins) of the continent, ultimately encouraging adoption as the country's reference screening tool for management and conservation purposes.

  13. Spatio-temporal distribution of Diaphanosoma brachyurum (Cladocera: Sididae in freshwater reservoir ecosystems: importance of maximum water depth and macrophyte beds for avoidance of fish predation

    Directory of Open Access Journals (Sweden)

    Jong-Yun Choi

    2014-10-01

    Full Text Available In empirical studies, Cladocera is commonly utilized as a primary food source for predators such as fish, thus, predator avoidance are important strategies to sustain their population in freshwater ecosystems. In this study, we tested the hypothesis that water depth is an important factor in determining the spatial distribution of Diaphanosoma brachyurum Liévin, 1848 in response to fish predation. Quarterly monitoring was implemented at three water layers (i.e., water surface and middle and bottom layers in 21 reservoirs located in the southeastern part of South Korea. D. brachyurum individuals were