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Sample records for canadian freshwater fishes

  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. 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...

  3. Effects of Pollution on Freshwater Fish.

    Science.gov (United States)

    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)

  4. Mercury in freshwater ecosystems of the Canadian Arctic: recent advances on its cycling and fate.

    Science.gov (United States)

    Chételat, John; Amyot, Marc; Arp, Paul; Blais, Jules M; Depew, David; Emmerton, Craig A; Evans, Marlene; Gamberg, Mary; Gantner, Nikolaus; Girard, Catherine; Graydon, Jennifer; Kirk, Jane; Lean, David; Lehnherr, Igor; Muir, Derek; Nasr, Mina; Poulain, Alexandre J; Power, Michael; Roach, Pat; Stern, Gary; Swanson, Heidi; van der Velden, Shannon

    2015-03-15

    The Canadian Arctic has vast freshwater resources, and fish are important in the diet of many Northerners. Mercury is a contaminant of concern because of its potential toxicity and elevated bioaccumulation in some fish populations. Over the last decade, significant advances have been made in characterizing the cycling and fate of mercury in these freshwater environments. Large amounts of new data on concentrations, speciation and fluxes of Hg are provided and summarized for water and sediment, which were virtually absent for the Canadian Arctic a decade ago. The biogeochemical processes that control the speciation of mercury remain poorly resolved, including the sites and controls of methylmercury production. Food web studies have examined the roles of Hg uptake, trophic transfer, and diet for Hg bioaccumulation in fish, and, in particular, advances have been made in identifying determinants of mercury levels in lake-dwelling and sea-run forms of Arctic char. In a comparison of common freshwater fish species that were sampled across the Canadian Arctic between 2002 and 2009, no geographic patterns or regional hotspots were evident. Over the last two to four decades, Hg concentrations have increased in some monitored populations of fish in the Mackenzie River Basin while other populations from the Yukon and Nunavut showed no change or a slight decline. The different Hg trends indicate that the drivers of temporal change may be regional or habitat-specific. The Canadian Arctic is undergoing profound environmental change, and preliminary evidence suggests that it may be impacting the cycling and bioaccumulation of mercury. Further research is needed to investigate climate change impacts on the Hg cycle as well as biogeochemical controls of methylmercury production and the processes leading to increasing Hg levels in some fish populations in the Canadian Arctic. PMID:24993511

  5. 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.

  6. 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.

  7. 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.

  8. 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...

  9. Implications of dam obstruction for global freshwater fish diversity

    OpenAIRE

    Reidy Liermann, Catherine; Nilsson, Christer; Robertson, James; Ng, Rebecca

    2012-01-01

    Dams are obstructing rivers worldwide, impairing habitat and migration opportunities for many freshwater fish species; however, global data linking dam and fish distributions have been limited. Here, we quantify dam obstruction at the biogeographic scale of freshwater ecoregion, which provides the spatial framework necessary to assess the risk of fish species loss due to dams and allows us to identify both ecoregions and genera at risk. Nearly 50% of the 397 assessed freshwater ecoregions are...

  10. Climate and local abundance in freshwater fishes.

    Science.gov (United States)

    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. PMID:27429769

  11. 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.

  12. Histopathology of Marine and Freshwater Fish Lymphocytosis Disease Virus (LCDV)

    International Nuclear Information System (INIS)

    Lymphocytosis disease (LCD) in fishes is caused by the agent called lymphocytosis disease virus (LCDV). LCDV is a chronic and benign virus. The disease affects 96 species of marine and fresh water fishes ranged among 34 families in the world. Affected fish with LCD has a typical external symptom with clusters consisted of enormously hypertrophied dermal cells on the skin and fins. The hypertrophied cells, generally named lymphocytosis cells, have a thick hyaline capsule, an enlarged nucleus and prominent basophilic cytoplasmic inclusions. Among the four species of fishes, olive flounder Paralichthys olivaceus, and rockfish Sebastes schlegeli were marine cultured fish, and gourami Trichogaster leeri and painted glass fish Channa baculis were freshwater ornamental fish. Although LCD causes low mortality, the disfigurement of infected fish can make them unsellable. Thus LCD has resulted in an important economic loss in the aquaculture industry. This study of histopathology may be adequate for a presumptive diagnosis of lymphocytosis diseases both in marine and freshwater fish species. (author)

  13. 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...

  14. Richness and endemism of the freshwater fishes of Mexico

    OpenAIRE

    T. Contreras-MacBeath; M. B. Rodríguez; Sorani, V.; Goldspink, C.; G. McGregor Reid

    2014-01-01

    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). Se...

  15. Organic environmental poisons in Norwegian freshwater fish

    International Nuclear Information System (INIS)

    According to this article, the level of organic poisons in Norwegian freshwater fish is, on the whole, is too small to threaten human health. It has been found, however, that liver from some species such as burbot, from some lakes, should not be eaten. These lakes are found to contain higher levels of PCB (polychlorinated biphenyls) and DDT (dichlorodiphenyltrichloroethane). Previously, pregnant or breast-feeding women anywhere in Norway have been advised not to eat pike, large perch or large trout because of too much mercury. Other people should not eat these species more often than once per month. In general, the level of organic environmental poisons is higher in the southern part of the country than in the northern part. The sediments of the lakes in large parts of South Norway are contaminated with lead, mercury and cadmium as compared with the conditions before the industrial revolution. However, the level of metals in the lake sediments are relatively low, and these substances are unlikely to appear in the food chain, by and large. The anthropogenic emission of lead was insignificant before the industrial revolution. The exception of lead from German mining industry in the 1700s

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

    OpenAIRE

    LAURA URDES; MARIUS HANGAN; CRISTIANA DIACONESCU; DANIELA IANIłCHI; VLAD SERAFIM

    2013-01-01

    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 be...

  17. 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

  18. 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.

  19. THE DEVELOPMENT OF FRESHWATER FISHING IN ELAZIĞ

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    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.

  20. Recent progress on our understanding of the biological effects of mercury in fish and wildlife in the Canadian Arctic.

    Science.gov (United States)

    Scheuhammer, Anton; Braune, Birgit; Chan, Hing Man; Frouin, Héloïse; Krey, Anke; Letcher, Robert; Loseto, Lisa; Noël, Marie; Ostertag, Sonja; Ross, Peter; Wayland, Mark

    2015-03-15

    This review summarizes our current state of knowledge regarding the potential biological effects of mercury (Hg) exposure on fish and wildlife in the Canadian Arctic. Although Hg in most freshwater fish from northern Canada was not sufficiently elevated to be of concern, a few lakes in the Northwest Territories and Nunavut contained fish of certain species (e.g. northern pike, Arctic char) whose muscle Hg concentrations exceeded an estimated threshold range (0.5-1.0 μg g(-1) wet weight) within which adverse biological effects begin to occur. Marine fish species generally had substantially lower Hg concentrations than freshwater fish; but the Greenland shark, a long-lived predatory species, had mean muscle Hg concentrations exceeding the threshold range for possible effects on health or reproduction. An examination of recent egg Hg concentrations for marine birds from the Canadian Arctic indicated that mean Hg concentration in ivory gulls from Seymour Island fell within the threshold range associated with adverse effects on reproduction in birds. Mercury concentrations in brain tissue of beluga whales and polar bears were generally lower than levels associated with neurotoxicity in mammals, but were sometimes high enough to cause subtle neurochemical changes that can precede overt neurotoxicity. Harbour seals from western Hudson Bay had elevated mean liver Hg concentrations along with comparatively high muscle Hg concentrations indicating potential health effects from methylmercury (MeHg) exposure on this subpopulation. Because current information is generally insufficient to determine with confidence whether Hg exposure is impacting the health of specific fish or wildlife populations in the Canadian Arctic, biological effects studies should comprise a major focus of future Hg research in the Canadian Arctic. Additionally, studies on cellular interactions between Hg and selenium (Se) are required to better account for potential protective effects of Se on Hg

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

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    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

  2. Freshwater fishes of Patagonia: conservation and fisheries.

    Science.gov (United States)

    Cussac, V E; Habit, E; Ciancio, J; Battini, M A; Riva Rossi, C; Barriga, J P; Baigún, C; Crichigno, S

    2016-07-01

    The absence of much literature on the Patagonian fish fauna in comparison with that of the neotropics, has previously been blamed on its poor species diversity. Knowledge of the fishes of Patagonia, however, rose sharply at the beginning of the present century, allowing for an understanding of the complex biogeographical history that has led to the present diversity and distribution patterns. There are several new and potential threats to biodiversity and conservation of Patagonian fishes, such as the introduction of exotic species, damming, climate change and changes geared to safeguard economic interests, often acting synergistically. A great amount of new information is now available and the aim of the present review is to articulate this knowledge in a comprehensive way in order to aid in the development of tools to face the increasing challenges posed by environmental change and human activity. Knowledge about fishes of Patagonia has grown at the same time as human actions, and presence. PMID:27284012

  3. Changes during storage of freshwater fish

    OpenAIRE

    KAŇKA, Martin

    2014-01-01

    The aim of this thesis was to focus on changes during storage. I reviewed in detail the kinds of storage and fish processing. I compared changes in fish during cooling, freezing, mincing meat, smoking, marinating, and sterilizing in cans. Sparing method of storage is cooling, when are preserve chemical and physical properties of the meat. Storage time is relatively short The meat during storage succumbed sensory changes in color, aroma, consistency. When the cooling is deficient, occurs the ...

  4. 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.

  5. CAGE BREEDING OF WARM WATER FRESHWATER FISH SPECIES

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    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

  6. 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...

  7. 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.

  8. CHIRONOMUS PLUMOSUS LARVAE - A SUITABLE NUTRIENT FOR FRESHWATER FARMED FISH

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    I. Bogut

    2007-06-01

    Full Text Available Crude protein, fat, water, ash, dry matter and essential amino and fatty acids were analyzed from freshly collected Chironomus plumosus larvae in order to evaluate their suitability as a component for farmed fish diet. The analyses were performed in intact living organisms and in the dry matter. Essential amino acids were determined by LKB 4101 automatic analyzer, while fatty acids were determined by Chronopack CP 9000 chromatograph with flame ionization detector. Crude protein content was 7.6% and 55.7% in fresh larvae and dry matter, respectively, being a value adequate for growth needs of all freshwater fish sorts and categories. Most essential amino acids in fresh larvae and dry matter are present in quantities adequate for feeding majority of omnivorous and carnivorous freshwater fish species. Crude fat content was 1.3% and 9.7% in fresh larvae and dry matter, respectively, being energetically sufficient for all warm-water living fish. The crude fat contains 26.12% saturated, 30.42% monounsaturated and 34.03% polyunsaturated fatty acids (PUFA. Among the highly unsaturated fatty acids (HUFA, the most abundant is linolenic (7.21%, followed by eicosapentanoic (4.36%, docosahexaenoic (2.49% and docosapentaenoic (1.16% acid. The measured quantity of ω-3 and ω-6 fatty acids (essential for omnivorous fish, as well as ω-6 to ω-3 fatty acid ratio (0.81, completely meets nutritional requirements of carp and tench.

  9. Parasitic Helminth Infection in Tropical Freshwater Fishes of Commercial Fish Farms, in Morelos State, Mexico

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    D. Hernández-Ocampo

    2012-10-01

    Full Text Available The principal aim of this study was realize a helminthological register of the species founded in ornamental fishes cultured in three fish farms and wild fishes existent in the effluents close to these farms in Morelos State, Mexico and an analysis and comparation of the infection values and their relative importance of helminth species invaders associated to ornamental fish industry and their manifestation in wild fishes close to farms. The helminth parasites of freshwater fishes of commercial fish farms, in Morelos State, Mexico were analysed. A total of 419 organisms of six freshwater fish species were collected in three fish farms and in small streams adjacent, in rainy and dry seasons. A total of 40 528 helminth were collected; the metacercarian of the flatworm Centrocestus formosanus affected largest number of host species. There were high levels of infection in all fish for this fluke, specifically for the Mexican molly, Poecilia sphenops it was also found in the native poeciliid fish the Asian tapeworm Botriocephalus acheilognathi, although with lower values in the parameters of infection. A non-deteriorated environment allowed complete the life cycles of parasites, permitting the establishment and maturation in various native and exotic fishes favoured the lack of host specificity of helminths and allogeneic generalists.

  10. Nutritional requirements of freshwater ornamental fish: a review

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    Yohana Velasco-Santamaría

    2011-05-01

    Full Text Available The knowledge of nutritional requirements in ornamental fish species is essential to improve the productive development; however, the nutritional information of these species is scarce and sometimes this information is extrapolated from results obtained from non-ornamental fish species. In ornamental fish, a correct formulation of the diet improve the nutrient digestibility and supply the metabolic needs, reducing the maintenance cost and at the same time the water pollution. Inert food such as meal powder, flakes, milk powder, bovine heart and liver, tubifex worms, as well as live food including Artemia sp., rotifers and Moina have been used extensively in ornamental fish feeding with a diverse range of nutritional values and productive properties. In contrast with farmed fish, skin pigmentation is a mandatory characteristic in ornamental fish and the use of dietary supplements with carotenoids is recommended. The aim of this document is to review the specific nutritional requirements which are indispensable to improve economical and productive potential of freshwater ornamental fish.

  11. Fish stranding in freshwater systems: sources, consequences, and mitigation.

    Science.gov (United States)

    Nagrodski, Alexander; Raby, Graham D; Hasler, Caleb T; Taylor, Mark K; Cooke, Steven J

    2012-07-30

    Fish can become stranded when water levels decrease, often rapidly, as a result of anthropogenic (e.g., canal drawdown, hydropeaking, vessel wakes) and natural (e.g., floods, drought, winter ice dynamics) events. We summarize existing research on stranding of fish in freshwater, discuss the sources, consequences, and mitigation options for stranding, and report current knowledge gaps. Our literature review revealed that ∼65.5% of relevant peer-reviewed articles were found to focus on stranding associated with hydropower operations and irrigation projects. In fact, anthropogenic sources of fish stranding represented 81.8% of available literature compared to only 19.9% attributed to natural fish stranding events. While fish mortality as a result of stranding is well documented, our analysis revealed that little is known about the sublethal and long-term consequences of stranding on growth and population dynamics. Furthermore, the contribution of stranding to annual mortality rates is poorly understood as are the potential ecosystem-scale impacts. Mitigation strategies available to deal with stranding include fish salvage, ramping rate limitations, and physical habitat works (e.g., to contour substrate to minimize stranding). However, a greater knowledge of the factors that cause fish stranding would promote the development and refinement of mitigation strategies that are economically and ecologically sustainable. PMID:22481278

  12. Histopathological study on parasites in freshwater ornamental fishes in Iran.

    Science.gov (United States)

    Nematollahi, A; Jaberi, S; Helan, J Ashrafi; Sheikhzadeh, N

    2016-09-01

    During March 2012 through February 2013, 100 freshwater ornamental fishes in 22 species from some aquarium fish shops were examined. Specimens were dissected and tissue samples consisted of liver, kidney, spleen, heart, intestine, ovary, brain and eye were fixed in 10 % buffered formalin and sections were provided and stained with hematoxylin and eosin, Periodic Acid-Schiff, Giemsa and acid-fast staining (Ziehl-Neelsen). At present study six species of protozoans consisting of Eimeria spp. Cryptosporidium spp., Tetrahymena corlissi, Thecamoeba spp., Giardia spp., Myxobolus spp. and two metazoan parasite consisting of Nematoda spp. and Benedenia monticelli were identified. Thecamoeba, B. monticelli and Cryptosporidium spp. were not reported in previous Iranian studies and it is the first report of infestation to this parasite in ornamental fish in Iran. PMID:27605779

  13. 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

  14. Conservation status of imperiled north American freshwater and diadromous fishes

    Science.gov (United States)

    Jelks, H.L.; Walsh, S.J.; Burkhead, N.M.; Contreras-Balderas, Salvador; Diaz-Pardo, E.; Hendrickson, D.A.; Lyons, J.; Mandrak, N.E.; McCormick, F.; Nelson, Joseph S.; Platania, S.P.; Porter, B.A.; Renaud, C.B.; Schmitter-Soto, J. J.; Taylor, E.B.; Warren, M.L., Jr.

    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 genera and 36 families, a 92% increase over the 364 listed in 1989. The increase reflects the addition of distinct populations, previously non-imperiled fishes, and recently described or discovered taxa. Approximately 39% of described fish species of the continent are imperiled. There are 230 vulnerable, 190 threatened, and 280 endangered extant taxa, and 61 taxa presumed extinct or extirpated from nature. Of those that were imperiled in 1989, most (89%) are the same or worse in conservation status; only 6% have improved in status, and 5% were delisted for various reasons. Habitat degradation and nonindigenous species are the main threats to at-risk fishes, many of which are restricted to small ranges. Documenting the diversity and status of rare fishes is a critical step in identifying and implementing appropriate actions necessary for their protection and management.

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

    OpenAIRE

    Ruixin Liu; Linhai Wu; Lijie Shan; Chunxian Han

    2015-01-01

    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 perc...

  16. 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.

  17. Development of intermediate foodstuff derived from freshwater fish in China

    Science.gov (United States)

    Wang, Xichang; Fukuda, Yutaka; Chen, Shunsheng; Yokoyama, Masahito; Cheng, Yudong; Yuan, Chunhong; Qu, Yinghong; Sakaguchi, Morihiko

    2005-07-01

    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 wall-eye 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.

  18. 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.

  19. 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.

  20. Exchanges of volume, heat and freshwater through the Canadian Arctic Archipelago: a numerical study.

    Science.gov (United States)

    Grivault, Nathan; Hu, Xianmin; Myers, Paul G.

    2016-04-01

    The Canadian Arctic Archipelago (CAA) is a tangle of shallow basins interlinked by narrow straits. It is the main pathway of liquid freshwater from the Arctic Ocean to North Atlantic. It also receives runoff from the Mackenzie River and the glaciers of the different islands that composes the archipelago. This study is based on a set of numerical experiments using a regional configuration of the coupled ocean/sea-ice general circulation model NEMO. We consider a long-term hindcast (1958-2014) as well as the more recent period (2002-2014) using high resolution inter-annual forcing from Environment Canada. We used an improved mapping of runoff to ensure correct amounts of freshwater are added to the system. We evaluate the flow pathways through the CAA, as well as the transport of volume, heat and freshwater. Results are evaluated against observational sections. We also look at the variability and the dynamics driving it. Passive tracers are used to complement the analysis.

  1. An analysis of Nigerian freshwater fishes: those under threat and conservation options

    OpenAIRE

    Olaosebikan, B.D.; Bankole, N.O.

    2005-01-01

    The study assessed qualitatively the threat status of all nigerian freshwater fishes using such criteria as rarity, size at maturity, mode of reproduction, human population density, habitat degradation, pollution and range of each species among others. The biology of 48% (129n) of nigerian freshwater species is not well known. Of the 266 known freshwater fishes, 47 species represented 17% are critically endangered, 15 (5%) are endangered , 8(3%), are vulnerable while 23(8%) are near threatene...

  2. 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.

  3. DIVERSITY OF HELMINTHS OF FRESHWATER FISH IN THE OASES OF BAJA CALIFORNIA SUR, MEXICO

    OpenAIRE

    Mendez, Oscar

    2013-01-01

    Some oases have been evaluated and characterized on the basis of certain biological groups. However, there is nothing known of the helminths in these freshwater environments. We analyzed the diversity of helminths of freshwater fish in thirteen desert oases of Baja California Sur (BCS), Mexico. There were 472 individuals of nine species of fish examined. 24 helminth species were recorded on 273 fish (58%); of these, 176 (64%) were parasitized with a single species and 97 (36%) ...

  4. Geographical linkages between threats and imperilment in freshwater fish in the Mediterranean Basin

    OpenAIRE

    Clavero, Miguel; Hermoso, Virgilio; Levin, Noam; Kark, Salit

    2010-01-01

    Aim The level of imperilment of mediterranean freshwater fish is among the highest recorded for any group of organisms evaluated to date. Here, we describe the geographical patterns in the incidence of threats affecting mediterranean freshwater fish and test whether the effects of specific threats are spatially related to the degree of imperilment of fish faunas. Location The Mediterranean Basin Biome. Methods From the IUCN Red List, we recorded the six main threats to 232 e...

  5. 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

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

    International Nuclear Information System (INIS)

    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+ 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+ 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 (R2 = 61%) and the consumption of PCB-BP+ freshwater fish (R2 = 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+ 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 general population. - Highlights:

  7. Spatial segregation of freshwater fish in an intermittent Cuban stream.

    Directory of Open Access Journals (Sweden)

    José Luis Ponce de León

    2013-09-01

    Full Text Available The spatial segregation of fish species is related to the use of available resources in every river or lake segment. In this work the spatial distribution of four endemic and one introduced freshwater fish species from the Govea stream, in Havana Province, Cuba was studied between june and november of 2005. Both, the effect of sun incidence and the segregation in the water column were analyzed. Gambusia punctata Poey, 1854 feeds on invertebrates, mainly on the surface zone, while herbivores like Girardinus metallicus Poey, 1854 are found in the intermediate zone more frequently. The detritivores like Limia vittata Guichenot, 1853 and Plecostomus commersoni Valenciennes, 1836, and the omnivorous cichlid Nandopsis tetracanthus (Cuvier y Valenciennes, 1831, were found mostly at the bottom. Differences in the mean number of individuals were found for most species in same-depth transects except for N. tetracanthus. In zones exposed to direct sunlight G. metallicus, L. vittata and P. commersoni were found more abundant, whereas G. punctata was mainly noticed in shade areas.

  8. 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.

  9. 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.

  10. 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.

  11. 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. PMID:25283218

  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. Effects of salinity on freshwater fishes in coastal plain drainages in the southeastern U.S.

    Science.gov (United States)

    Peterson, Mark S.; Meador, Michael R.

    1994-01-01

    This review focuses on the influence of salinity on freshwater fishes in coastal rivers and estuaries of the southeastern U.S. Influences of salinity on freshwater fish species can be explained partly through responses evidenced by behavior, physiology, growth, reproduction, and food habits during all aspects of life history. Factors influencing the rate of salinity change affect the community structure and dynamics of freshwater fishes in brackish environments. Our understanding of the relation between salinity and the life history of freshwater fishes is limited because little ecological research has been conducted in low-salinity habitats that we consider an “interface” between freshwater streams and the estuary proper. Much of the available data are descriptive in nature and describe best general patterns, but more specific studies are required to better determine the influence of salinity on freshwater fishes. Improved understanding of the influence of human-induced changes on the productivity and viability of these important systems will require a new research focus.

  14. 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

    2016-01-01

    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. PMID:26497452

  15. 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.

  16. 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

  17. Community ecology of the metazoan parasites of freshwater fishes of Kerala

    OpenAIRE

    Beevi, M. Razia; Radhakrishnan, S.

    2012-01-01

    The prevalence and mean intensity of metazoan parasite infection, the community characteristics (richness index, dominance index, evenness index and Shannon index of diversity) and the qualitative similarity of the metazoan parasite fauna among the species and families of the fishes were determined of 13 fish species of freshwater fishes of Kerala belonging to seven families. The metazoan parasite fauna of this geographical area is very diverse; it consisted of 33 species of parasites belongi...

  18. 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...

  19. 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 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. PMID:23247527

  20. Fish extinctions alter nutrient recycling in tropical freshwaters

    OpenAIRE

    McIntyre, Peter B; Jones, Laura E.; Flecker, Alexander S.; Vanni, Michael J.

    2007-01-01

    There is increasing evidence that species extinctions jeopardize the functioning of ecosystems. Overfishing and other human influences are reducing the diversity and abundance of fish worldwide, but the ecosystem-level consequences of these changes have not been assessed quantitatively. Recycling of nutrients is one important ecosystem process that is directly influenced by fish. Fish species vary widely in the rates at which they excrete nitrogen and phosphorus; thus, altering fish communiti...

  1. FRESHWATER FISH FARMING CONDITIONS IN 1999 AND THE PRODUCTION PLAN FOR 2000

    Directory of Open Access Journals (Sweden)

    Zlatko Homen

    2000-09-01

    Full Text Available One of the activities of the Ministry of Agriculture and Forestry, Fishery and Mediterranean Agriculture Directorate, i. e. Fishery Directorate to be more specific, is the monitoring of conditions in freshwater fish farming. The objective of this work is to show conditions in freshwater fish farming during 1999. and to provide a production plan for 2000. It will also provide detailed insight into the present conditions in freshwater fish farming and into the production trends of this field. Regarding this issue, the »Questionnaire for the Monitoring of Conditions in Freshwater Fish Farming«, was sent to fish farmers aroud the country data was processed from 22 cap ponds and 13 trout ponds. Roughe estimates of conditions were conducted for 2 fish farms, since they haven’t yet returned the mandatoruy questionnaire, i. e. the necessary data. This work features data on the number of employees in fish farms, as well as their qualifications, on the actual production and distribution of farmed freshwater fish, on the areas where production was conducted and on the overall yield. Fish food, raw materials, used tools and incentive funds paid were also taken into consideration. The difficulties faced in this branch of the economy are also inicated. Compared to 1998, a slight decrease in the number of employees of freshwater fish farms has been recorded. The total number of employees in 1999 was 655, of which 555 were on carp ponds and 100 on trout ponds. Data on the qualifications of employees for 1999 show that most of them were unskilled workers, while highly skilled workers make up a minority in this work force. The total production of freshwater in 1999. amoounted to 6.185,51 tons. Of this amount 5.592,52 tons were warm-water fish specied and 592,99 tons were cold-water fish species. Compared to 1998, production decreased by 4,89 percent. Production for 2000 has been planned to increase by 22,15 percent, i. e. the production quantity is projected

  2. Research on marine and freshwater fish identification model based on hyper-spectral imaging technology

    Science.gov (United States)

    Fu, Yan; Guo, Pei-yuan; Xiang, Ling-zi; Bao, Man; Chen, Xing-hai

    2013-08-01

    With the gradually mature of hyper spectral image technology, the application of the meat nondestructive detection and recognition has become one of the current research focuses. This paper for the study of marine and freshwater fish by the pre-processing and feature extraction of the collected spectral curve data, combined with BP network structure and LVQ network structure, a predictive model of hyper spectral image data of marine and freshwater fish has been initially established and finally realized the qualitative analysis and identification of marine and freshwater fish quality. The results of this study show that hyper spectral imaging technology combined with the BP and LVQ Artificial Neural Network Model can be used for the identification of marine and freshwater fish detection. Hyper-spectral data acquisition can be carried out without any pretreatment of the samples, thus hyper-spectral imaging technique is the lossless, high- accuracy and rapid detection method for quality of fish. In this study, only 30 samples are used for the exploratory qualitative identification of research, although the ideal study results are achieved, we will further increase the sample capacity to take the analysis of quantitative identification and verify the feasibility of this theory.

  3. 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).

  4. Nutritional requirements of freshwater ornamental fish: a review

    OpenAIRE

    Yohana Velasco-Santamaría; Wilson Corredor-Santamaría

    2011-01-01

    The knowledge of nutritional requirements in ornamental fish species is essential to improve the productive development; however, the nutritional information of these species is scarce and sometimes this information is extrapolated from results obtained from nonornamental fish species. In ornamental fish, a correct formulation of the diet improve the nutrient digestibility and supply the metabolic needs, reducing the maintenance cost and at the same time the water pollution. Inert food such a...

  5. 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

  6. Scientific uncertainty and the assessment of risks posed by non-native freshwater fishes

    OpenAIRE

    Leprieur, Fabien; Brosse, S.; Garcia Berthou, E.; Oberdorff, Thierry; Olden, J.D.; Townsend, C.R.

    2009-01-01

    The introduction of non-indigenous plants, animals and pathogens is a pressing global environmental challenge. Although not all introduced species become established and the fraction of those that do often have little appreciable effect on their new ecosystems, many others exert significant ecological, evolutionary and economic impacts. Stimulating further debate, Gozlan [Fish and Fisheries (2008) Vol. 9, pp. 106-115] argued that the majority of intentional freshwater fish introductions assoc...

  7. 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.

  8. 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

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

    DEFF Research Database (Denmark)

    Jensen, Ann Britt Bang

    -living fish. The following specific objectives are addressed: Objective 1: To determine the susceptibility of selected European freshwater fish to a panel of ranaviruses Objective 2: To determine whether ornamental fish are susceptible to or can be carriers of ranaviruses Objective 3: To develop a model...... describing the risk of introduction and spread of exotic ranaviruses in European wild and farmed aquatic ecosystems Objectives 1 and 2 have been addressed by experimental trials involving bath challenges of both European farmed and wild fish species and ornamental fish species. The results showed that some...... and susceptibility trials in fish, and discussed in the context of taxonomy and legislation. Objective 3 was addressed by using the principles from the OIE risk assessment framework to develop a generic risk model for assessing the risk of introducing exotic ranaviruses into the EU via imports of infected ornamental...

  10. 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.

  11. Accidental Bait: Do Deceased Fish Increase Freshwater Turtle Bycatch in Commercial Fyke Nets?

    Science.gov (United States)

    Larocque, Sarah M.; Watson, Paige; Blouin-Demers, Gabriel; Cooke, Steven J.

    2012-07-01

    Bycatch of turtles in passive inland fyke net fisheries has been poorly studied, yet bycatch is an important conservation issue given the decline in many freshwater turtle populations. Delayed maturity and low natural adult mortality make turtles particularly susceptible to population declines when faced with additional anthropogenic adult mortality such as bycatch. When turtles are captured in fyke nets, the prolonged submergence can lead to stress and subsequent drowning. Fish die within infrequently checked passive fishing nets and dead fish are a potential food source for many freshwater turtles. Dead fish could thus act as attractants and increase turtle captures in fishing nets. We investigated the attraction of turtles to decomposing fish within fyke nets in eastern Ontario. We set fyke nets with either 1 kg of one-day or five-day decomposed fish, or no decomposed fish in the cod-end of the net. Decomposing fish did not alter the capture rate of turtles or fish, nor did it alter the species composition of the catch. Thus, reducing fish mortality in nets using shorter soak times is unlikely to alter turtle bycatch rates since turtles were not attracted by the dead fish. Interestingly, turtle bycatch rates increased as water temperatures did. Water temperature also influences turtle mortality by affecting the duration turtles can remain submerged. We thus suggest that submerged nets to either not be set or have reduced soak times in warm water conditions (e.g., >20 °C) as turtles tend to be captured more frequently and cannot withstand prolonged submergence.

  12. 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.

  13. 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.

  14. Pre-anthropocene mercury residues in North American freshwater fish.

    Science.gov (United States)

    Hope, Bruce K; Louch, Jeff

    2014-04-01

    Mercury (Hg) has been entering the environment from both natural and anthropogenic sources for millennia, and humans have been influencing its environmental transport and fate from well before the Industrial Revolution. Exposure to Hg (as neurotoxic monomethylmercury [MeHg]) occurs primarily through consumption of finfish, shellfish, and marine mammals, and regulatory limits for MeHg concentrations in fish tissue have steadily decreased as information on its health impacts has become available. These facts prompted us to consider 2 questions: 1) What might the MeHg levels in fish tissue have been in the pre-Anthropocene, before significant human impacts on the environment? and 2) How would these pre-Anthropocene levels have compared with current regulatory criteria for MeHg residues in fish tissue? We addressed the first question by estimating pre-Anthropocene concentrations of MeHg in the tissues of prey and predatory fish with an integrated Hg speciation, transport, fate, and food web model (SERAFM), using estimated Hg concentrations in soil, sediment, and atmospheric deposition before the onset of significant human activity (i.e., ≤2000 BCE). Model results show MeHg residues in fish varying depending on the characteristics of the modeled water body, which suggests that Hg in fish tissue is best considered at the scale of individual watersheds or water bodies. We addressed the second question by comparing these model estimates with current regulatory criteria and found that MeHg residues in predatory (but not prey) fish could have approached or exceeded these criteria in some water bodies during the pre-Anthropocene. This suggests that the possibility of naturally occurring levels of Hg in fish below which it is not possible to descend, regardless of where those levels stand with respect to current regulatory limits. Risk management decisions made under these circumstances have the potential to be ineffectual, frustrating, and costly for decision makers and

  15. A novel oxyconforming response in the freshwater fish Galaxias maculatus.

    Science.gov (United States)

    Urbina, Mauricio A; Glover, Chris N; Forster, Malcolm E

    2012-03-01

    How fish oxygen consumption is modulated by external PO(2) has long been a matter of interest, yet is an experimentally complicated question to answer. In this study closed and semi-closed respirometry were used to evaluate the oxygen consumption rate of the scaleless galaxiid fish, inanga (Galaxias maculatus) as a function of decreasing external PO(2). Both respirometry techniques showed that as environmental oxygen levels declined, oxygen consumption rates also decreased. At no point did inanga regulate oxygen consumption. This is strong evidence that inanga is an oxyconformer. Partitioned respirometry experiments showed that skin plays an important role in oxygen uptake in this fish species, and cutaneous oxygen uptake may have an important role in shaping the oxygen consumption response to hypoxia. PMID:22138470

  16. 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

  17. 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.

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

    DEFF Research Database (Denmark)

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

    2014-01-01

    sequences exhibited a high identity (>99%) with hirame rhabdovirus (HIRRV), a novirhabdovirus usually found in fish in marine Asiatic countries, for instance Japan, China and Korea. The full-length sequence of the phosphoprotein gene (P) demonstrated a higher identity of the present isolate with HIRRV from......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...

  19. 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.

  20. 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.

  1. 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.

  2. Reproductive strategies and genetic variability in tropical freshwater fish

    OpenAIRE

    Maria Dolores Peres Lassala; Erasmo Renesto

    2007-01-01

    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. CHIRONOMUS PLUMOSUS LARVAE - A SUITABLE NUTRIENT FOR FRESHWATER FARMED FISH

    OpenAIRE

    Valentina Rajković; Zdeněk Adámek; Elizabeta Has-Schön; Ivan Bogut; Dalida Galović

    2007-01-01

    Crude protein, fat, water, ash, dry matter and essential amino and fatty acids were analyzed from freshly collected Chironomus plumosus larvae in order to evaluate their suitability as a component for farmed fish diet. The analyses were performed in intact living organisms and in the dry matter. Essential amino acidswere determined by LKB 4101 automatic analyzer, while fatty acids were determined by Chronopack CP 9000 chromatograph with flame ionization detector. Crude protein content was...

  4. Genotoxicity Effects in Freshwater Fish from a Brazilian Impacted River.

    Science.gov (United States)

    de Jesus, Isac Silva; Cestari, Marta Margarete; Bezerra, Marcos de Almeida; Affonso, Paulo Roberto Antunes de Mello

    2016-04-01

    This study evaluated the incidence of nuclear abnormalities (NA) in four fish species from an impacted river in Northeastern Brazil, characterized by accumulation of heavy metals and organic sewage. Two carnivores (Serrasalmus brandtii and Hoplias malabaricus) and two omnivore species (Oreochromis niloticus and Geophagus brasiliensis), used as food sources by local populations, were collected during the dry and the rainy season along Contas River basin. Nuclear abnormalities (bulbs, binuclei, lobes, micronuclei, notches, and vacuoles) were reported in all fish samples, with high occurrence in S. brandtii and H. malabaricus, species commonly found in local fish markets. This result agrees with previous analyses of accumulation of trace metals in both species, suggesting an association of genotoxic effects and biomagnification. Moreover, native specimens collected near urban areas presented higher frequencies of NA while O. niloticus seems to be more tolerant to environmental contamination. Therefore, effective policies are required to reduce the contamination of Contas River, since pollution by xenobiotics are potential threats to both local biodiversity and human population. PMID:26894492

  5. 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

  6. 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.

  7. 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.

  8. 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.

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

    OpenAIRE

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

    2016-01-01

    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 glo...

  10. PATHOGENICITY OF HENNEGUYA PSOROSPERMICA (PHYLUM MYXOZOA) ON FRESHWATER SPECIES OF FISH ORIGINATING FROM THE DANUBIAN DELTA

    OpenAIRE

    M. HANGAN; LAURA URDES; CRISTIANA DIACONESCU; P. VASILE

    2013-01-01

    The aim of this scientific work consisted in establishing the specific ethiology of gills infection, which has been found on the occasion of regullar clinic and anatomopathological examinations, in some freshwater species of fish originating from the Danubian Delta area. Following these examinations, there has been pointed out the macroscopical lesions of gills together with the presence and morphology of parasitic cysts. The microscopic examination of the cysts resulted in diagnosing the spe...

  11. 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.

  12. 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.

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

    Science.gov (United States)

    Borzym, E; Matras, M; Maj-Paluch, J; Baud, M; De Boisséson, C; Talbi, C; Olesen, N J; Bigarré, L

    2014-05-01

    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 to vesiculovirus-like species, except perch rhabdovirus (PRhV) with which it shared moderate serological relations. However, RT-PCR with PRhV probes gave negative results. To identify the virus, a random-priming sequence-independent single primer amplification was adopted. Surprisingly, two of the obtained sequences exhibited a high identity (>99%) with hirame rhabdovirus (HIRRV), a novirhabdovirus usually found in fish in marine Asiatic countries, for instance Japan, China and Korea. The full-length sequence of the phosphoprotein gene (P) demonstrated a higher identity of the present isolate with HIRRV from 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, and in two hosts from fresh water that have not been described before as susceptible species. PMID:23962315

  14. Evaluation of pathogenic fungi occurrence in traumatogenic structures of freshwater fish

    Directory of Open Access Journals (Sweden)

    Fabio Caetano Oliveira Leme

    2011-04-01

    Full Text Available INTRODUCTION: Fungal infections in human skin, such as sporotrichosis, can occur after fish induced trauma. This work aimed to identify fungi in freshwater fish that are pathogenic to humans. METHODS: Extraction of dental arches from Serrassalmus maculatus (piranha and Hoplias malabaricus (wolf fish, stings from Pimelodus maculatus (mandis catfish, dorsal fin rays from Plagioscion spp. (corvina and Tilapia spp., for culture in Mycosel agar. Some cultures were submitted to DNA extraction for molecular identification by sequencing ITS-5.8S rDNA. RESULTS: Cultures identified most yeast as Candida spp., while sequencing also permitted the identification of Phoma spp. and Yarrowia lipolytica. CONCLUSIONS: While the search for S. schenckii was negative, the presence of fungus of the genera Phoma and Candida revealed the pathogenic potential of this infection route. The genus Phoma is involved in certain forms of phaeohyphomycosis, a subcutaneous mycosis caused by dematiaceous fungi, with reports of infections in human organs and systems. Traumatizing structures of some freshwater fish present pathogenic fungi and this may be an important infection route that must be considered in some regions of Brazil, since there are a large number of a fisherman in constant contact with traumatogenic fish.

  15. Food Safety Hazards Related to Emerging Antibiotic Resistant Bacteria in Cultured Freshwater Fishes of Kolkata, India

    Directory of Open Access Journals (Sweden)

    T. Jawahar Abraham

    2011-02-01

    Full Text Available Association of opportunistic human bacterial pathogens in cultured freshwater fishes of Kolkata, India and their sensitivity to broad spectrum antibiotics was investigated. Both indigenous and non-indigenous human bacterial pathogens such as Aeromonas hydrophila, A. caviae, Edwardsiella tarda, Escherichia coli, Pseudomonas spp. and Vibrio parahaemolyticus were isolated from freshwater fishes of Kolkata. These strains were highly resistant to oxytetracycline (62% and nitrofurantoin (46%, and sensitive to ciprofloxacin (91% and chloramphenicol (89%. Multiple Antibiotic Resistance (MAR was high in catfishes (76% followed by miscellaneous fishes (66% and sewage-fed farm grown carps (55%. Among the bacterial species, the MAR was high in Ed. tarda (86%. More than 50% of the strains of A. hydrophila, A. caviae, E. coli, Pseudomonas spp., V. parahaemolyticus and unidentified Gram positive rods exhibited MAR. The results suggested that there is added risk of antibacterial resistance developing in the emerging human bacterial pathogens from freshwater aquaculture and of such antibiotic resistant bacterial pathogens entering the food chain.

  16. 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.

  17. 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. PMID:27220503

  18. 50 CFR 600.525 - Applicability of subpart F to Canadian Albacore Fishing Vessels off the West Coast.

    Science.gov (United States)

    2010-10-01

    ... 50 Wildlife and Fisheries 8 2010-10-01 2010-10-01 false Applicability of subpart F to Canadian Albacore Fishing Vessels off the West Coast. 600.525 Section 600.525 Wildlife and Fisheries FISHERY... Vessels off the West Coast. Fishing by vessels of Canada under the 1981 Treaty Between the Government...

  19. 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.

  20. Isolation and characterisation of flavobacteria from wild and cultured freshwater fish species in Hungary.

    Science.gov (United States)

    Varga, Zsuzsanna; Sellyei, Boglárka; Paulus, Petra; Papp, Melitta; Molnár, Kálmán; Székely, Csaba

    2016-03-01

    The objective of this study was to survey the incidence of Flavobacterium columnare in wild and cultured freshwater fish species in Hungary. This bacterium usually causes disease in waters of more than 25 °C temperature. However, with the introduction of intensive fish farming systems, infected fish exposed to stress develop disease signs also at lower temperatures; in addition, the temperature of natural waters rises to the critical level due to global warming. Twenty-five isolates from wild and cultured freshwater fishes were identified as F. columnare by specific PCR, although both the fragment lengths and the results of PCRRFLP genotyping with BsuRI (HaeIII) and RsaI restriction enzymes raised doubts regarding this species classification. Sequencing of the 16S ribosomal RNA gene revealed that 23 isolates belonged to the species F. johnsoniae and two represented Chryseobacterium spp. The isolates were found to have high-level multidrug resistance: all were resistant to ampicillin and polymyxin B, the 23 F. johnsoniae strains to cotrimoxazole, 88% of them to gentamicin, and 72% to chloramphenicol. The majority of the 25 isolates were sensitive to erythromycin (88%), furazolidone (76%), and florfenicol (68%). PMID:26919138

  1. Planning for Production of Freshwater Fish Fry in a Variable Climate in Northern Thailand

    Science.gov (United States)

    Uppanunchai, Anuwat; Apirumanekul, Chusit; Lebel, Louis

    2015-10-01

    Provision of adequate numbers of quality fish fry is often a key constraint on aquaculture development. The management of climate-related risks in hatchery and nursery management operations has not received much attention, but is likely to be a key element of successful adaptation to climate change in the aquaculture sector. This study explored the sensitivities and vulnerability of freshwater fish fry production in 15 government hatcheries across Northern Thailand to climate variability and evaluated the robustness of the proposed adaptation measures. This study found that hatcheries have to consider several factors when planning production, including: taking into account farmer demand; production capacity of the hatchery; availability of water resources; local climate and other area factors; and, individual species requirements. Nile tilapia is the most commonly cultured species of freshwater fish. Most fry production is done in the wet season, as cold spells and drought conditions disrupt hatchery production and reduce fish farm demand in the dry season. In the wet season, some hatcheries are impacted by floods. Using a set of scenarios to capture major uncertainties and variability in climate, this study suggests a couple of strategies that should help make hatchery operations more climate change resilient, in particular: improving hatchery operations and management to deal better with risks under current climate variability; improving monitoring and information systems so that emerging climate-related risks are known sooner and understood better; and, research and development on alternative species, breeding programs, improving water management and other features of hatchery operations.

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

    International Nuclear Information System (INIS)

    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

  3. 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.

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

    Directory of Open Access Journals (Sweden)

    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. 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. Total and inorganic arsenic in freshwater fish and prawn in Thailand.

    Science.gov (United States)

    Saipan, Piyawat; Ruangwises, Suthep; Tengjaroenkul, Bundit; Ruangwises, Nongluck

    2012-10-01

    Total and inorganic arsenic levels were determined in 120 samples of eight freshwater animal species collected from five distribution centers in the central region of Thailand between January and March 2011. Eight species with the highest annual catch, consisting of seven fish species and one prawn species, were analyzed. Concentrations of inorganic arsenic (on a wet weight basis) ranged from 0.010 μg/g in giant prawn (Macrobrachium rosenbergii) to 0.230 μg/g in striped snakehead (Channa striata). Climbing perch (Anabas testudineus) exhibited the highest mean concentrations of total arsenic (0.459 ± 0.137 μg/g), inorganic arsenic (0.121 ± 0.044 μg/g), and percentage of inorganic arsenic (26.2%). Inorganic arsenic levels found in freshwater animals in this study were much lower than the Thai regulatory standard of 2 μg/g. PMID:23043844

  7. 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. PMID:18278356

  8. Monogeneans of freshwater fishes from cenotes (sinkholes) of the Yucatan Peninsula, Mexico.

    Science.gov (United States)

    Mendoza-Franco, E F; Scholz, T; Vivas-Rodríguez, C; Vargas-Vázquez, J

    1999-01-01

    During a survey of the parasites of freshwater fishes from cenotes (sinkholes) of the Yucatan Peninsula the following species of monogeneans were found on cichlid, pimelodid, characid and poeciliid fishes: Sciadicleithrum mexicanum Kritsky, Vidal-Martinez et Rodriguez-Canul, 1994 from Cichlasoma urophthalmus (Günther) (type host), Cichlasoma friedrichsthali (Heckel), Cichlasoma octofasciatum (Regan), and Cichlasoma synspilum Hubbs, all new host records; Sciadicleithrum meekii Mendoza-Franco, Scholz et Vidal-Martínez, 1997 from Cichlasoma meeki (Brind); Urocleidoides chavarriai (Price, 1938) and Urocleidoides travassosi (Price, 1938) from Rhamdia guatemalensis (Günther); Urocleidoides costaricensis (Price et Bussing, 1967), Urocleidoides heteroancistrium (Price et Bussing, 1968), Urocleidoides anops Kritsky et Thatcher, 1974, Anacanthocotyle anacanthocotyle Kritsky et Fritts, 1970, and Gyrodactylus neotropicalis Kritsky et Fritts, 1970 from Astyanax fasciatus; and Gyrodactylus sp. from Gambusia yucatana Regan. Urocleidoides chavarriai, U. travassosi, U. costaricensis, U. heteroancistrium, U. anops, Anacanthocotyle anacanthocotyle and Gyrodactylus neotropicalis are reported from North America (Mexico) for the first time. These findings support the idea about the dispersion of freshwater fishes and their monogenean parasites from South America through Central America to southeastern Mexico, following the emergence of the Panamanian isthmus between 2 and 5 million years ago. PMID:10730199

  9. 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. PMID:18157635

  10. 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. PMID:20557658

  11. 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.

  12. 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.

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

    OpenAIRE

    Emmanuel Andrew Sweke; Julius Michael Assam; Abdillahi Ismail Chande; Athanasio Stephano Mbonde; Magnus Mosha; Abel Mtui

    2016-01-01

    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 ...

  14. Pelagic larval duration predicts extinction risk in a freshwater fish clade.

    Science.gov (United States)

    Douglas, Morgan; Keck, Benjamin P; Ruble, Crystal; Petty, Melissa; Shute, J R; Rakes, Patrick; Hulsey, C Darrin

    2013-01-01

    Pelagic larval duration (PLD) can influence evolutionary processes ranging from dispersal to extinction in aquatic organisms. Using estimates of PLD obtained from species of North American darters (Percidae: Etheostomatinae), we demonstrate that this freshwater fish clade exhibits surprising variation in PLD. Comparative analyses provide some evidence that higher stream gradients favour the evolution of shorter PLD. Additionally, similar to patterns in the marine fossil record in which lower PLD is associated with greater extinction probability, we found a reduced PLD in darter lineages was evolutionarily associated with extinction risk. Understanding the causes and consequences of PLD length could lead to better management and conservation of organisms in our increasingly imperiled aquatic environments.

  15. PATHOGENICITY OF HENNEGUYA PSOROSPERMICA (PHYLUM MYXOZOA ON FRESHWATER SPECIES OF FISH ORIGINATING FROM THE DANUBIAN DELTA

    Directory of Open Access Journals (Sweden)

    M. HANGAN

    2013-12-01

    Full Text Available The aim of this scientific work consisted in establishing the specific ethiology of gills infection, which has been found on the occasion of regullar clinic and anatomopathological examinations, in some freshwater species of fish originating from the Danubian Delta area. Following these examinations, there has been pointed out the macroscopical lesions of gills together with the presence and morphology of parasitic cysts. The microscopic examination of the cysts resulted in diagnosing the specific pathological agent, which was the metazoan Henneguya psorospermica. These aspects and more are being presented in this paper.

  16. 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...

  17. 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.

  18. 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.

  19. Cross-Cordillera exchange mediated by the Panama Canal increased the species richness of local freshwater fish assemblages.

    OpenAIRE

    Smith, Scott A; Bell, Graham; Bermingham, Eldredge

    2004-01-01

    Completion of the Panama Canal in 1914 breached the continental divide and set into motion a natural experiment of unprecedented magnitude by bringing previously isolated freshwater fish communities into contact. The construction of a freshwater corridor connecting evolutionarily isolated communities in Pacific and Caribbean watersheds dramatically increased the rate of dispersal, without directly affecting species interactions. Here, we report that a large fraction of species have been able ...

  20. An Evaluation of Adult Freshwater Mussels Held in Captivity at the White Sulphur Springs National Fish Hatchery, West Virginia

    OpenAIRE

    Boyles, Julie L.

    2004-01-01

    Due to the increasing need to provide refugia for freshwater mussels impacted by anthropogenic activities and exotic species, facilities should be identified and protocols developed for holding mussels in captivity. White Sulphur Springs National Fish Hatchery (WSSNFH), White Sulphur Springs, WV, has held freshwater mussels for nearly eight years, and has the potential to become an important refugium and propagation facility for conservation of mussels in the Ohio River Basin and elsewhere. ...

  1. New and previously described species of Dactylogyridae (Monogenoidea) from the gills of Panamanian freshwater fishes (Teleostei).

    Science.gov (United States)

    Mendoza-Franco, Edgar F; Aguirre-Macedo, M Leopoldina; Vidal-Martínez, Victor M

    2007-08-01

    During an investigation of the diversity of metazoan parasites of 7 freshwater fish species from 3 localities in central Panama, the following gill dactylogyrid (Monogenoidea) species were found: Aphanoblastella chagresii n. sp. from Pimelodella chagresi (Heptapteridae); Aphanoblastella travassosi (Price, 1938) Kritsky, Mendoza-Franco, and Scholz, 2000 from Rhamdia quelen (Heptapteridae); Diaphorocleidus petrosusi n. sp. from Brycon petrosus (Characidae); Gussevia asota Kritsky, Thatcher, and Boeger, 1989, from Astronotus ocellatus (Cichlidae); Sciadicleithrum panamensis n. sp. from Aequidens coeruleopunctatus (Cichlidae); Urocleidoides flegomai n. sp. from Piabucina panamensis (Lebiasinidae); and Urocleidoides similuncus n. sp. from Poecilia gillii (Poeciliidae). Consideration of the comparative morphology and distribution of these parasites along with the evolutionary history of the host fishes suggests that diversification may be associated with geotectonic events that provided isolation of the Central American fauna with the uplift of the Panamanian Isthmus during early Pliocene (3 mya). PMID:17918354

  2. 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.

  3. Community ecology of the metazoan parasites of freshwater fishes of Kerala.

    Science.gov (United States)

    Beevi, M Razia; Radhakrishnan, S

    2012-10-01

    The prevalence and mean intensity of metazoan parasite infection, the community characteristics (richness index, dominance index, evenness index and Shannon index of diversity) and the qualitative similarity of the metazoan parasite fauna among the species and families of the fishes were determined of 13 fish species of freshwater fishes of Kerala belonging to seven families. The metazoan parasite fauna of this geographical area is very diverse; it consisted of 33 species of parasites belonging to seven major taxa: ten species of Monogenea, nine Digenea, two Cestoda, six Nematoda, three Acanthocephala, two Copepoda and one Isopoda. Prevalence of infection ranged from 32.9% (Puntius vittatus) to 87.1% (Mystus oculatus) and mean intensity from 3.8 (Puntius vittatus) to 27.6 (Aplocheilus lineatus). The infra- and component communities of parasites were somewhat characteristic. The dominance pattern of the major taxa was in the order Digenea > Nematoda > Monogenea = Acanthocephala > Cestoda = Copepoda > Isopoda. Macropodus cupanus harboured the richest fauna and Puntius vittatus had the least rich fauna. The parasite fauna of A. lineatus was the most heterogeneous and that of M. cavasius, the most homogeneous. The diversity of the parasite fauna was the greatest in M. cavasius and the least in A. lineatus. The parasite faunas of A. lineatus and M. cupanus and of M. cavasius and M. oculatus were similar. However, in spite of the taxonomic nearness and the similarity of the habits and habitats of the four species of cyprinids (P. amphibius, P. filamentosus, P. sarana and P. vittatus), their parasite fauna were qualitatively very dissimilar-of the seven species of parasites encountered in them only one was shared by the four host species. The cyprinid, Rasbora daniconius, had its own characteristic component community of parasites consisting of six species none of which was shared by the other four cyprinids. The richest parasite fauna was that of the family

  4. (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. PMID:27061778

  5. 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. PMID:24334744

  6. 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.

  7. Consumption of freshwater fish by recreational and native freshwater anglers in the upper St-Maurice (Quebec, Canada) and estimation of the intake of methylmercury in humans

    International Nuclear Information System (INIS)

    Hydro-Quebec is planning to build two hydroelectric reservoirs in the upper Saint-Maurice River, which would flood about 80% of the surrounding area. The methylmercury (MeHg) content in freshwater fish will therefore tend to increase during the first few years. This development will have a direct impact on the amount of MeHg that the actual users of this river section are exposed to. The objective of this study is to assess the consumption of local fish of these target groups using a Monte-Carlo approach. This study is part of a larger research project aimed at assessing human exposure and the health risks related to MeHg contamination in local fish. The fish consumption rate for recreational freshwater anglers was calculated using the duration of the average annual fishing trip, the average number of catches per species, the average fish weight per species exceeding a specific length of fish usually caught, and the edible portion of fish consumed. This rate was calculated for the native communities based on the total number of meals per year per species, the average fish weight per species, and the edible portion. Based on these calculations, average intake for sport fishermen is estimated at 6.9 g/day (sd = 6.4). This value is 5 to 25 times lower on average than for other North American native communities. However, it must be pointed out that the food habits of the native population were very similar to those of non-native populations; less than 30% of the food comes from traditional sources

  8. 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

    2016-03-01

    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. PMID:27010409

  9. 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.

  10. 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)

  11. 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.

  12. 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.

  13. 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. PMID:25800305

  14. 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

    2011-03-01

    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. PMID:21291233

  15. 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

  16. 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.

  17. The impacts of stress on sodium metabolism and copper accumulation in a freshwater fish.

    Science.gov (United States)

    Harley, Rachel A; Glover, Chris N

    2014-02-01

    In freshwater fish, stress can often result in significant modifications to Na(+) metabolism and may be an important aspect to consider in conservation efforts; as maintaining ion balance is critical to survival and ion transport is also a key determinant of metal toxicity. In order to better quantify the response of stress, Na(+) influx, Na(+) efflux, and copper accumulation were measured as a result of handling stress in inanga (Galaxias maculatus). This species is a culturally and economically important fish in New Zealand as one of the major species in the local 'whitebait' fishery. Na(+) influx rates in inanga were found to be 2-3 times greater after handling than in 'recovered' fish, and Na(+) efflux rates increased in the range of 5-6 times. Both influx and efflux rates quickly returned to resting levels within 24h. Increases in Na(+) efflux were strongly correlated with opercular beat frequency. This suggests an increas in ventilation, and subsequent enhanced diffusive loss of Na(+), as the mechanism of increased Na(+) efflux. Total body copper levels were also measured under similar treatments. Fish had significantly higher levels of copper directly after handling than following a 24h recovery; likely due to a shared Na(+)/copper uptake pathway. As accumulation is linked to toxicity, fish exposed to elevated copper levels in stressful environments will consequently be more at risk to metal toxicity. In a natural environment, stress can come from many different sources; among which, anthropogenic disturbances can often be a cause. Given that inanga must migrate through metal-contaminated coastal regions to reach breeding habitats, they will be exposed to toxicants under conditions where perfusion and ventilation of the gill is increased. As such, ion loss would be exacerbated, leading to an enhanced compensatory ion uptake and an increase in accumulation of ion-mimicking toxicants such as copper, exacerbating toxicity. This is a concern as conservation

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

    Directory of Open Access Journals (Sweden)

    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

  19. Ecological studies on the freshwater fishes of the Alligator Rivers region, Northern Territory

    International Nuclear Information System (INIS)

    The tropical climate of the Alligator Rivers Region (ARR) has a distinctive wet-dry cycle , resulting in seasonal flows in the creeks and rivers of its catchments. The present study, begun in August 1978, was aimed at developing an ecological monitoring system that would detect any changes to the freshwater fish communities brought about by recent uranium mining and processing in the lowlands of the ARR. The focus of the synecological studies, was a description of spatial and temporal patterns in the community structure of the fish fauna. Interpretation of these patterns was made possible by the collection of detailed environmental data from the study sites. It was found that of the ARR seasonal changes in environmental conditions were so marked that they often obscured the effects of environmental gradients along a watercourse and differing environmental conditions characteristics of different types of waterbody. Hence it may not be entirely satisfactory to define environmental zones in these catchments based on overall environmental conditions through the whole seasonal cycle, because changes in any one such zone between seasons result in very marked changes in the fish communities of habitats in that zone. 34 refs., 22 tabs., 45 figs., 3 maps

  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. Conflict between background matching and social signalling in a colour-changing freshwater fish.

    Science.gov (United States)

    Kelley, Jennifer L; Rodgers, Gwendolen M; Morrell, Lesley J

    2016-06-01

    The ability to change coloration allows animals to modify their patterning to suit a specific function. Many freshwater fishes, for example, can appear cryptic by altering the dispersion of melanin pigment in the skin to match the visual background. However, melanin-based pigments are also used to signal dominance among competing males; thus colour change for background matching may conflict with colour change for social status signalling. We used a colour-changing freshwater fish to investigate whether colour change for background matching influenced aggressive interactions between rival males. Subordinate males that had recently darkened their skin for background matching received heightened aggression from dominant males, relative to males whose coloration had not changed. We then determined whether the social status of a rival male, the focal male's previous social status, and his previous skin coloration, affected a male's ability to change colour for background matching. Social status influenced skin darkening in the first social encounter, with dominant males darkening more than subordinate males, but there was no effect of social status on colour change in the second social encounter. We also found that the extent of skin colour change (by both dominant and subordinate males) was dependent on previous skin coloration, with dark males displaying a smaller change in coloration than pale males. Our findings suggest that skin darkening for background matching imposes a significant social cost on subordinate males in terms of increased aggression. We also suggest that the use of melanin-based signals during social encounters can impede subsequent changes in skin coloration for other functions, such as skin darkening for background matching. PMID:27429764

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

    Science.gov (United States)

    Strecker, A.L.; Olden, J.D.; Whittier, Joanna B.; Paukert, C.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 tradeoffs 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 multiple

  3. 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.

  4. Can Species Distribution Models Aid Bioassessment when Reference Sites are Lacking? Tests Based on Freshwater Fishes

    Science.gov (United States)

    Labay, Ben J.; Hendrickson, Dean A.; Cohen, Adam E.; Bonner, Timothy H.; King, Ryan S.; Kleinsasser, Leroy J.; Linam, Gordon W.; Winemiller, Kirk O.

    2015-10-01

    Recent literature reviews of bioassessment methods raise questions about use of least-impacted reference sites to characterize natural conditions that no longer exist within contemporary landscapes. We explore an alternate approach for bioassessment that uses species site occupancy data from museum archives as input for species distribution models (SDMs) stacked to predict species assemblages of freshwater fishes in Texas. When data for estimating reference conditions are lacking, deviation between richness of contemporary versus modeled species assemblages could provide a means to infer relative biological integrity at appropriate spatial scales. We constructed SDMs for 100 freshwater fish species to compare predicted species assemblages to data on contemporary assemblages acquired by four independent surveys that sampled 269 sites. We then compared site-specific observed/predicted ratios of the number of species at sites to scores from a multimetric index of biotic integrity (IBI). Predicted numbers of species were moderately to strongly correlated with the numbers observed by the four surveys. We found significant, though weak, relationships between observed/predicted ratios and IBI scores. SDM-based assessments identified patterns of local assemblage change that were congruent with IBI inferences; however, modeling artifacts that likely contributed to over-prediction of species presence may restrict the stand-alone use of SDM-derived patterns for bioassessment and therefore warrant examination. Our results suggest that when extensive standardized survey data that include reference sites are lacking, as is commonly the case, SDMs derived from generally much more readily available species site occupancy data could be used to provide a complementary tool for bioassessment.

  5. 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

  6. Occurrence, bioaccumulation and potential sources of polybrominated diphenyl ethers in typical freshwater cultured fish ponds of South China

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Baozhong [State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China); Graduate School, Chinese Academy of Sciences, Beijing 100049 (China); Ni Honggang [Key Laboratory for Environmental Urban Sciences, Shenzhen Graduate School, Peking University, Shenzhen 518055 (China); Guan Yufeng [State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China); Graduate School, Chinese Academy of Sciences, Beijing 100049 (China); Zeng, Eddy Y., E-mail: eddyzeng@gig.ac.c [State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China)

    2010-05-15

    To determine the potential input sources of polybrominated diphenyl ethers (PBDEs) to fish farming environments in South China, samples of seven various environmental matrices were collected from October 2006-September 2007. Tri- to deca-BDEs were detected in all samples analyzed, with mean concentrations (+-standard deviations) at 5.7 +- 3.6 ng/L in pond water, 15 +- 11 ng/g dry wt. in pond sediment, 12 +- 3.8 ng/g dry wt. in bank soil, 21 +- 20 ng/g lipid wt. in fish, and 93 +- 62 ng/g lipid wt. in fish feeds. In addition, BDE-209 was the major constituent in all samples except fish and BDE-47 was predominant in fish samples. Relatively high abundances of BDE-49 were detected in all the samples compared to those in the penta-BDE technical products. Several bioaccumulation factors were evaluated. Finally, statistical analyses suggested that fish feed, as well as pond water at a lesser degree, may have been the major source of PBDEs in freshwater farmed fish. - Occurrence and sources of polybrominated diphenyl ethers in typical freshwater cultured fish ponds of the Pearl River Delta, South China are examined.

  7. 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. PMID:23494159

  8. Transcriptome profiling of two Iberian freshwater fish exposed to thermal stress.

    Science.gov (United States)

    Jesus, Tiago Filipe; Grosso, Ana Rita; Almeida-Val, Vera Maria Fonseca; Coelho, Maria Manuela

    2016-01-01

    The congeneric freshwater fish Squalius carolitertii and S. torgalensis inhabit different Iberian regions with distinct climates; Atlantic in the North and Mediterranean in the South, respectively. While northern regions present mild temperatures, fish in southern regions often experience harsh temperatures and droughts. Previous work with two hsp70 genes suggested that S. torgalensis is better adapted to harsher thermal conditions than S. carolitertii as a result of the different environmental conditions. We present a transcriptomic characterisation of these species' thermal stress responses. Through differential gene expression analysis of the recently available transcriptomes of these two endemic fish species, comprising 12 RNA-seq libraries from three tissues (skeletal muscle, liver and fins) of fish exposed to control (18 °C) and test (30 °C) conditions, we intend to lay the foundations for further studies on the effects of temperature given predicted climate changes. Results showed that S. carolitertii had more upregulated genes, many of which are involved in transcription regulation, whereas S. torgalensis had more downregulated genes, particularly those responsible for cell division and growth. However, both species displayed increased gene expression of many hsps genes, suggesting that they are able to deal with protein damage caused by heat, though with a greater response in S. torgalensis. Together, our results suggest that S. torgalensis may have an energy saving strategy during short periods of high temperatures, re-allocating resources from growth to stress response mechanisms. In contrast, S. carolitertii regulates its metabolism by increasing the expression of genes involved in transcription and promoting the stress response, probably to maintain homoeostasis. Additionally, we indicate a set of potential target genes for further studies that may be particularly suited to monitoring the responses of Cyprinidae to changing temperatures, particularly

  9. 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

  10. Length weight relationship and condition factor of selected freshwater fish species found in river Ganga, Gomti and Rapti, India.

    Science.gov (United States)

    Sarkar, U K; Khan, G E; Dabas, A; Pathak, A K; Mir, J I; Rebello, S C; Pal, A; Singh, S P

    2013-09-01

    This study is based on the length-weight relationships (LWRs) of 2148 fishes, belonging to 8 families, 12 genera and 15 freshwater fish species (Wallago attu, Rite rita, Sperato seenghala, Sperota aor, Mostacembalus armatus, Macrognathus puncolus, Gudusia chopra, Clupisoma garua, Puntius sophore, Puntius ticto, Rasbora daniconius, Amblypharyngodon mole, Chanda noma, Colisa fociatus and Colisa sota) captured from river Ganga, Gomti and Rapti during May 2011 to March 2012. The growth coefficient (b) values varied between 1.30 and 3.07, with the mean b = 2.03 at priver basin. The objective was to evaluate the pattern of LWRs and condition factors of the freshwater fish species of the main Ganga and tributaries which serves as baseline for other tropical Indian rivers and tributaries.

  11. Length weight relationship and condition factor of selected freshwater fish species found in river Ganga, Gomti and Rapti, India.

    Science.gov (United States)

    Sarkar, U K; Khan, G E; Dabas, A; Pathak, A K; Mir, J I; Rebello, S C; Pal, A; Singh, S P

    2013-09-01

    This study is based on the length-weight relationships (LWRs) of 2148 fishes, belonging to 8 families, 12 genera and 15 freshwater fish species (Wallago attu, Rite rita, Sperato seenghala, Sperota aor, Mostacembalus armatus, Macrognathus puncolus, Gudusia chopra, Clupisoma garua, Puntius sophore, Puntius ticto, Rasbora daniconius, Amblypharyngodon mole, Chanda noma, Colisa fociatus and Colisa sota) captured from river Ganga, Gomti and Rapti during May 2011 to March 2012. The growth coefficient (b) values varied between 1.30 and 3.07, with the mean b = 2.03 at priver basin. The objective was to evaluate the pattern of LWRs and condition factors of the freshwater fish species of the main Ganga and tributaries which serves as baseline for other tropical Indian rivers and tributaries. PMID:24558811

  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. Shape up or ship out: migratory behaviour predicts morphology across spatial scale in a freshwater fish.

    Science.gov (United States)

    Chapman, Ben B; Hulthén, Kaj; Brönmark, Christer; Nilsson, P Anders; Skov, Christian; Hansson, Lars-Anders; Brodersen, Jakob

    2015-09-01

    1. Migration is a widespread phenomenon, with powerful ecological and evolutionary consequences. Morphological adaptations to reduce the energetic costs associated with migratory transport are commonly documented for migratory species. However, few studies have investigated whether variation in body morphology can be explained by variation in migratory strategy within a species. 2. We address this question in roach Rutilus rutilus, a partially migratory freshwater fish that migrates from lakes into streams during winter. We both compare body shape between populations that differ in migratory opportunity (open vs. closed lakes), and between individuals from a single population that vary in migratory propensity (migrants and residents from a partially migratory population). Following hydrodynamic theory, we posit that migrants should have a more shallow body depth, to reduce the costs associated with migrating into streams with higher flow conditions than the lakes the residents occupy all year round. 3. We find evidence both across and within populations to support our prediction, with individuals from open lakes and migrants from the partially migratory population having a more slender, shallow-bodied morphology than fish from closed lakes and all-year residents. 4. Our data suggest that a shallow body morphology is beneficial to migratory individuals and our study is one of the first to link migratory strategy and intraspecific variation in body shape. PMID:25823702

  14. Comparing distribution models for small samples of overdispersed counts of freshwater fish

    Science.gov (United States)

    Vaudor, Lise; Lamouroux, Nicolas; Olivier, Jean-Michel

    2011-05-01

    The study of species abundance often relies on repeated abundance counts whose number is limited by logistic or financial constraints. The distribution of abundance counts is generally right-skewed (i.e. with many zeros and few high values) and needs to be modelled for statistical inference. We used an extensive dataset involving about 100,000 fish individuals of 12 freshwater fish species collected in electrofishing points (7 m 2) during 350 field surveys made in 25 stream sites, in order to compare the performance and the generality of four distribution models of counts (Poisson, negative binomial and their zero-inflated counterparts). The negative binomial distribution was the best model (Bayesian Information Criterion) for 58% of the samples (species-survey combinations) and was suitable for a variety of life histories, habitat, and sample characteristics. The performance of the models was closely related to samples' statistics such as total abundance and variance. Finally, we illustrated the consequences of a distribution assumption by calculating confidence intervals around the mean abundance, either based on the most suitable distribution assumption or on an asymptotical, distribution-free (Student's) method. Student's method generally corresponded to narrower confidence intervals, especially when there were few (≤3) non-null counts in the samples.

  15. Physiological effects of gasoline on the freshwater fish Prochilodus lineatus(Characiformes: Prochilodontidae

    Directory of Open Access Journals (Sweden)

    Juliana D. Simonato

    2013-09-01

    Full Text Available The purpose of this work was to evaluate the effects of the water-soluble fraction of gasoline (WSFG on the Neotropical freshwater fish Prochilodus lineatus. The WSFG was prepared by mixing gasoline in water (1:4 and animals were exposed for 6, 24 and 96h to 5% diluted WSFG or only to water. After exposure, blood was collected from the caudal vein and the gills were removed. The following parameters were analyzed: hematological (hemoglobin, hematocrit, number of red blood cells, osmo-ionic (plasma Na+, Cl- and K+ and plasma osmolarity, metabolic (total plasma proteins and glucose, endocrine (cortisol, density and distribution of chloride cells [CC] in the gills (immunohistochemistry, and branchial Na+/K+-ATPase (NKA activity. Hemolysis was found to occur after 96h exposure to WSFG, as indicated by the decrease in the hematological parameters analyzed, followed by an increase in plasma K+. Secondary stress response was revealed by the occurrence of hyperglycemia in the three periods of exposure, despite the absence of significant increases in the plasma cortisol. The exposure to WSFG also caused an increase in the quantity of CC and in plasma Na+, after 24h, as well as in the enzymatic activity of NKA and plasma osmolarity, after 24h and 96h. These results indicate that fish exposed to the WSFG showed physiological adjusts to maintain their osmotic balance. However, the increase in the quantity of CC in the lamellae may interfere in the gas exchange impairing respiration.

  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. 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.

  18. 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.

  19. Cladogenesis and loss of the marine life-history phase in freshwater galaxiid fishes (Osmeriformes: Galaxiidae).

    Science.gov (United States)

    Waters, J M; Wallis, G P

    2001-03-01

    Switches from migratory (diadromous) to nonmigratory (freshwater) life histories are known to have occurred repeatedly in some aquatic taxa. However, the significance of the loss of diadromy as an initiator for speciation remains poorly understood. The rivers of New Zealand's South Island house a species flock of recently derived nonmigratory galaxiid fishes known as the Galaxias vulgaris complex. Members of this complex are morphologically and genetically similar to the diadromous G. brevipinnis found in New Zealand and southeastern Australia. We hypothesised that South Island's G. vulgaris complex (at least 10 nonmigratory lineages) represents a number of independent radiations from a migratory G. brevipinnis stock, with repeated loss of diadromy. Sequence data were obtained for 31 ingroup samples (G. vulgaris complex and G. brevipinnis) plus four outgroup taxa. A well-resolved phylogeny based on 5039 base pairs of the mitochondrial genome suggests that diadromy has been lost on three separate occasions. Thus, speciation in these galaxiid fishes is partly an incidental phenomenon caused by switches from diadromous to nonmigratory strategies. However, much of the subsequent nonmigratory diversity is monophyletic, suggesting that drainage evolution (vicariance) has also played a major role in cladogenesis. Levels of sequence divergence among major ingroup lineages (1.6-12.7%) suggest that the radiation is considerably older relative to Northern Hemisphere (postglacial) complexes of salmonid, osmerid, and gasterosteid fishes. Sympatric taxa are not monophyletic, suggesting that their coexistence reflects secondary contact rather than sympatric speciation. The monophyly of New Zealand G. brevipinnis is well supported, but both mitochondrial DNA and nuclear sequences indicate that G. brevipinnis is paraphyletic on an intercontinental scale. The divergence (maximum 11.5%) between Tasmanian and New Zealand G. brevipinnis, although large, supports marine dispersal rather

  20. Residual levels of DDTs and PAHs in freshwater and marine fish from Hong Kong markets and their health risk assessment.

    Science.gov (United States)

    Cheung, K C; Leung, H M; Kong, K Y; Wong, M H

    2007-01-01

    Axial and ventral muscle from 10 each species of freshwater and marine fish purchased from markets in Hong Kong were analyzed for dichlorodiphenyltrichloroethane (total DDTs including DDE, DDD and DDT) and polycyclic aromatic hydrocarbons (PAHs). Among the 10 freshwater fish species, rice field eel (Monopterus albus) showed significantly higher levels of DDTs in both ventral (125 ng/g wet wt) and axial muscle (127 ng/g wet wt) than the other species. The highest concentration of PAHs was detected in catfish (Clarias fuscus), with 24.8 ng/g in ventral muscle and 9.1 ng/g in axial muscle. As to marine fish, snubnose pompano (Trachinotus blochii) showed significantly higher levels of DDT and its metabolites (1018 ng/g in ventral and 409 ng/g wet wt in axial tissues) than all other marine fish species. The overall concentrations of PAHs in marine fish species were 15.5-57.0 ng/g (axial muscle) and 18.1-118 ng/g wet wt (ventral muscle) where yellow seafin (Acanthopeyrus latus) and golden threadfin bream (Nemipterus virgatus) exhibited the highest concentrations of PAHs in the axial and ventral muscles, respectively. In general, results showed that levels of PAHs in Hong Kong market fish was low and do not expect to cause any concern for human consumption. However, the levels of DDTs in fish samples ranged from 1.10 to 1018 ng/g wet wt, and based on a fish consumption rate of 142.2g/day to calculate the screening value of 14.4 ng/g wet wt for human consumption (USEPA, 2000. Guidance for assessing chemical contaminant, data for use in fish advisories, vol. 1: fish sampling and analysis, third ed. EPA 823-R-95-007. Office of Water, Washington, DC), there were 9 out of 20 (45%) muscle samples of freshwater fish species and 14 out of 20 (70%) muscle samples of marine fish species had elevated levels of DDTs exceeded the screening value. It was also suggested to use ventral muscle for detecting concentrations of persistent organic pollutants in fish. PMID:16870232

  1. Gene trees versus species trees: reassessing life-history evolution in a freshwater fish radiation.

    Science.gov (United States)

    Waters, Jonathan M; Rowe, Diane L; Burridge, Christopher P; Wallis, Graham P

    2010-10-01

    Mechanisms of speciation are best understood in the context of phylogenetic relationships and as such have often been inferred from single gene trees, typically those derived from mitochondrial DNA (mtDNA) markers. Recent studies, however, have noted the potential for phylogenetic discordance between gene trees and underlying species trees (e.g., due to stochastic lineage sorting, introgression, or selection). Here, we employ a variety of nuclear DNA loci to reassess evolutionary relationships within a recent freshwater fish radiation to reappraise modes of speciation. New Zealand's freshwater-limited Galaxias vulgaris complex is thought to have evolved from G. brevipinnis, a widespread migratory species that retains a plesiomorphic marine juvenile phase. A well-resolved tree, based on four mtDNA regions, previously suggested that marine migratory ability has been lost on 3 independent occasions in the evolution of this species flock (assuming that loss of diadromy is irreversible). Here, we use pseudogene (galaxiid Numt: 1801 bp), intron (S: 903 bp), and exon (RAG-1: 1427 bp) markers, together with mtDNA, to reevaluate this hypothesis of parallel evolution. Interestingly, partitioned Bayesian analysis of concatenated nuclear sequences (3141 bp) and concatenated nuclear and mtDNA (4770 bp) both recover phylogenies implying a single loss of diadromy, not three parallel losses as previously inferred from mtDNA alone. This phylogenetic result is reinforced by a multilocus analysis performed using Bayesian estimation of species trees (BEST) software that estimates the posterior distribution of species trees under a coalescent model. We discuss factors that might explain the apparently misleading phylogenetic inferences generated by mtDNA. PMID:20603441

  2. 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

  3. 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. PMID:26872885

  4. 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.

  5. A population assessment of mercury exposure from two cities of Pakistan with respect to freshwater and marine fish consumption.

    Science.gov (United States)

    Shah, Abdul Qadir; Kazi, Tasneem Gul; Afridi, Hassan Imran; Arain, Mohammad Balal

    2016-06-01

    In this study, we aimed to estimate the level of mercury (Hg) in scalp hair samples of human subjects and its association with consumption of sea- and freshwater fish species. The scalp hairs were collected from both genders (male and female) aged between 15 and 50 years (n = 200), living in coastal areas of Karachi, who mostly consumed sea fish species, referred to as exposed subjects. For comparison purposes, scalp hair samples of both genders (n = 160) were collected from the inhabitants of Karachi and Hyderabad cities who consumed freshwater fish species termed as referent subjects. The frequently consumed fresh and marine fish species were also collected. The level of Hg was determined in fish and scalp hair samples by cold vapor atomic absorption spectrometry, prior to ultrasonic-assisted acid digestion in a mixture of nitric acid and hydrogen peroxide. The validity of methodology was checked by certified reference material (CRM) BCR 397 (human hair) and DORM-2. The concentrations of Hg in sea- and freshwater fish were found in the range of 1.47-2.09 and 0.402-0.676 μg/g, respectively. The exposed subjects had significantly elevated levels of Hg in scalp hair samples (1.8-4.3 μg/g) as compared to referent subjects (0.87-1.95 μg/g) (p < 0.001). A significant positive correlation was obtained between the concentration of Hg in hair and age of study population. Exposed and referent female subjects had higher levels of Hg in scalp hair than that in males of both study groups (p = 0.02-0.031). PMID:25147303

  6. Histo-morphology of the alimentary canal in two freshwater snakehead fish Channa punctata and Channa striata

    OpenAIRE

    Mita Borman; Ismot Ara; Mohammad Kamrujjaman; Md Rafiqun Nabi

    2015-01-01

    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...

  7. 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. PMID:10701569

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

    Directory of Open Access Journals (Sweden)

    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.

  9. 海鱼与淡水鱼的营养味道区别%Nutrition Taste Difference between Fish and Freshwater Fish

    Institute of Scientific and Technical Information of China (English)

    孙建华

    2016-01-01

    High nutritional value of fish is good source of protein nutrition intake of human. Due to the different environment for the growth of marine and freshwater fish, there is great difference between them, especially, there is a certain difference in the nutrition and taste. Based on this, marine and freshwater fish nutrition and flavor were compared, so that people can learn more about the nutritional value of marine and freshwater ifsh.%鱼类的营养价值很高,是人类摄入蛋白质的良好来源,由于海鱼和淡水鱼的生长环境不同,所以他们之间有很大的差别,尤其是在营养成分和味道上有一定的差别。基于此,对海鱼和淡水鱼的营养和味道进行对比,让人们更加了解海鱼和淡水鱼的营养价值。

  10. Larvae of Contracaecum sp. (Nematoda: Anisakidae) in the threatened freshwater fish Sandelia capensis (Anabantidae) in South Africa.

    Science.gov (United States)

    Moravec, Franti Ek; van Rensburg, Candice Jansen; Van As, Liesl L

    2016-08-01

    Third-stage larvae of the nematode genus Contracaecum Railliet et Henry, 1912 (Contracaecum sp.) were, for the first time, recorded from the abdominal cavity of the threatened endemic freshwater fish Sandelia capensis (Cuvier) in South Africa. The larval morphology indicated that they belong to a species of which the adults are parasitic in fish-eating birds. Although the nematode seems to be a common parasite of S. capensis in the locality under study (prevalence 23%), the low intensity of infection recorded (1 to 4) and the generally known low pathogenicity of Contracaecum larvae in fish indicate that this parasite probably does not represent a danger to the local population of this threatened fish species. PMID:27503922

  11. Freshwater fish faunas, habitats and conservation challenges in the Caribbean river basins of north-western South America.

    Science.gov (United States)

    Jiménez-Segura, L F; Galvis-Vergara, G; Cala-Cala, P; García-Alzate, C A; López-Casas, S; Ríos-Pulgarín, M I; Arango, G A; Mancera-Rodríguez, N J; Gutiérrez-Bonilla, F; Álvarez-León, R

    2016-07-01

    The remarkable fish diversity in the Caribbean rivers of north-western South America evolved under the influences of the dramatic environmental changes of neogene northern South America, including the Quechua Orogeny and Pleistocene climate oscillations. Although this region is not the richest in South America, endemism is very high. Fish assemblage structure is unique to each of the four aquatic systems identified (rivers, streams, floodplain lakes and reservoirs) and community dynamics are highly synchronized with the mono-modal or bi-modal flooding pulse of the rainy seasons. The highly seasonal multispecies fishery is based on migratory species. Freshwater fish conservation is a challenge for Colombian environmental institutions because the Caribbean trans-Andean basins are the focus of the economic development of Colombian society, so management measures must be directed to protect aquatic habitat and their connectivity. These two management strategies are the only way for helping fish species conservation and sustainable fisheries. PMID:27401480

  12. Transfer Factors of 137Cs and 85Sr by Freshwater Fish in Tropical Environment

    International Nuclear Information System (INIS)

    The experiment was set up to determine the radionuclide transfer factors (T.F.) of 137Cs and 85Sr by tropical freshwater fish. Mixed breeding catfish between Thai catfish (Clarias acrocephalus) and African catfish (Clarias garispinus African sharptooth) were exposed to 137Cs and 85Sr in two 1000-L tanks for 42 days during uptake phase. The calculated T.F. at equilibrium, in flesh, bone, skin plus fin and head were 3.2, 2.6, 1.6 and 1.5 L.kg-1 for 137Cs and 0.1, 4, 1 and 17 L.kg-1 for 90Sr, respectively. These results revealed a much lower values than reported elsewhere for temperate environment, however were in accordance with the tropical values as observed by others. The biological half-lives of 137Cs and 85Sr in flesh part were 41 and 4 days respectively. It is then imperative that suitable T.F. values are employed in the models to predict the transport of radionuclides within the particular ecosystem and the potential dose to man. Thus the relationship between routine release of radionuclides and resulting dose to man can be established and corresponding release limits stipulated for that particular nuclear site

  13. 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.

  14. 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.

  15. 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. PMID:25899744

  16. The history of critical group doses from the consumption of freshwater fish at Trawsfynydd, North Wales

    International Nuclear Information System (INIS)

    Radionuclides discharged into the aquatic environment from Trawsfynydd power station are, as for all UK facilities, subject to statutory controls to ensure that the resulting public radiation exposure complies with nationally-accepted criteria. Environmental monitoring by MAFF has shown that near this facility the consumption of freshwater fish is radiologically the most important pathway with Cs-137 the dominant radionuclide. Information gathered from consumers over a twenty-five year period has been interpreted so as to derive doses to the public. Committed effective doses (CEDs) are presented using ICRP 1990 methodology and compared with the recommended dose limit of 1 mSv year-1. Doses to the critical group are shown to have exceeded 1 mSv year-1 for two years but do not exceed this limit when averaged over a period of 5 years. Because of the changing habits of the consumers it is suggested that the average annual CED over the lifetime of any member of the public will not exceed 1 mSv year-1 during the operation of the station. (author)

  17. 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.

  18. 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.

  19. 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

  20. 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.

  1. 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.

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

    International Nuclear Information System (INIS)

    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 137Cs 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 137Cs concentrations in different fish

  3. 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

  4. 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.

  5. Development and evaluation of a regression-based model to predict cesium concentration ratios for freshwater fish

    International Nuclear Information System (INIS)

    Data from published studies and World Wide Web sources were combined to produce and test a regression model to predict Cs concentration ratios for freshwater fish species. The accuracies of predicted concentration ratios, which were computed using 1) species trophic levels obtained from random resampling of known food items and 2) K concentrations in the water for 207 fish from 44 species and 43 locations, were tested against independent observations of ratios for 57 fish from 17 species from 25 locations. Accuracy was assessed as the percent of observed to predicted ratios within factors of 2 or 3. Conservatism, expressed as the lack of under prediction, was assessed as the percent of observed to predicted ratios that were less than 2 or less than 3. The model's median observed to predicted ratio was 1.26, which was not significantly different from 1, and 50% of the ratios were between 0.73 and 1.85. The percentages of ratios within factors of 2 or 3 were 67 and 82%, respectively. The percentages of ratios that were <2 or <3 were 79 and 88%, respectively. An example for Perca fluviatilis demonstrated that increased prediction accuracy could be obtained when more detailed knowledge of diet was available to estimate trophic level. - Highlights: • We developed a model to predict Cs concentration ratios for freshwater fish species. • The model uses only two variables to predict a species CR for any location. • One variable is the K concentration in the freshwater. • The other is a species mean trophic level measure easily obtained from (fishbase.org). • The median observed to predicted ratio for 57 independent test cases was 1.26

  6. 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.

  7. 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

    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...... 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......, 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...

  8. 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.

  9. 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. PMID:27551225

  10. 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

  11. 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.

  12. 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 (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.

  13. 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 (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.

  14. 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.

  15. 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.

  16. The prevalence, antimicrobial resistance and PFGE profiles of Laribacter hongkongensis in retail freshwater fish and edible frogs of southern China.

    Science.gov (United States)

    Feng, Jia-li; Hu, Jing; Lin, Jin-yan; Liu, Shan; Chowdhury, Nityananda; Zhang, Ou; Li, Jian-dong; Shi, Lei; Yamasaki, Shinji; Chen, Qing

    2012-10-01

    Laribacter hongkongensis is a novel emerging pathogen associated with human gastroenteritis. We aimed to investigate the prevalence, antimicrobial resistance and genotypic relationship of 199 L. hongkongensis isolates from 690 intestinal samples of fish and frogs. These samples were collected from retail markets in the city of Guangzhou in southern China from October 2008 to September 2009. L. hongkongensis was detected in from 80 (16.3%) out of 490 freshwater fish, and this number included 76 (32.3%) out of 235 grass carp and 4 (14.8%) out of 27 bighead carp. A higher isolation rate of 59.5% (119 out of 200) was observed in edible frogs. The isolation rate was highest in the spring in comparison with other seasons. Notably, 63.8% of the isolates were resistant to at least one class of antimicrobial agents. Analysis by pulsed-field gel electrophoresis (PFGE) revealed that the isolates could be grouped into three clusters. Isolates from fish intestines were grouped into two clusters: cluster I and II. Isolates of frog-origin and several fish-origin isolates were grouped into cluster III. Two patient-derived strains could be classed into cluster III. Extensive genetic heterogeneity among the isolates was observed. The results indicate that L. hongkongensis isolates exhibits host tropism, extensive resistance to widely used antimicrobials and diverse biological evolution in an aquatic environment. The frog is more likely than the freshwater fish to be the potential source for human infection with L. hongkongensis. PMID:22850382

  17. 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.

  18. 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.

  19. 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. PMID:27503877

  20. 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.

  1. A new species of Dermoergasilus Ho & Do, 1982 (Copepoda: Ergasilidae) from freshwater fishes in the south-west of Western Australia.

    Science.gov (United States)

    Hassan, Marina; Jones, Brian; Lymbery, Alan J

    2009-10-01

    A new species of Dermoergasilus Ho & Do, 1982 is described from freshwater fish hosts in the south west of Western Australia. D. occidentalis n. sp. differs from previously described species in the genus principally by the armature of the legs. The new species was found on the gills of the freshwater cobbler Tandanus bostocki Whitely and western minnow Galaxias occidentalis Ogilby in two different river systems. PMID:19731098

  2. INFLUENCED OF CYPERMETHRIN ON DNA, RNA AND RNA/DNA RATIO IN GILLS OF THE FRESHWATER FISH CHANNA STRIATA

    Directory of Open Access Journals (Sweden)

    Gracy A. Raksheskar

    2012-01-01

    Full Text Available In the present study the impact of subletal concentration of cypermethrin exposed to fresh water fish. The DNA, RNA and RNA/DNA ratio were estimated in gill of freshwater fish Channa striata. The sublethal concentration of cypermethrin (0.00078 µl/lit for 24, 48, 72 and 96 hours of different time intervals. The concentration of cypermethrin showed reduce level of DNA as 6.79, 15.77, 15.66, 15.36 in experimental and 15.20, 14.11, 12.16, 10.16 respectively for experimenntal RNA at different exposure period. Whereas the RNA/DNA ratio observed changed (2.23, 2.48, 2.27, 1.97 respectively at different exposure period as compares to control group.

  3. 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

    trutta), in 10 Tasmanian lakes and compared the results with those obtained from visual inspection of stomach contents. We obtained 44 unique taxa (OTUs) belonging to 5 phyla, including 7 classes, using the barcode of life approach from cytochrome oxidase I (COI). Compared with visual inspection, DNA...... analysis showed greater accuracy, yielding a 1.4-fold higher number of OTUs. Rarefaction curve analysis showed saturation of visually inspected taxa, while the curves from the DNA barcode did not saturate. The OTUs with the highest proportions of haplotypes were the families of terrestrial insects...... 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 and...

  4. Performances of models for predicting mercury concentrations in fresh-water fish after chronic releases into rivers

    International Nuclear Information System (INIS)

    The performances of assessment models for estimating the transfer and bioaccumulation of mercury in fresh-water ecosystems were tested by being applied to a test scenario proposed in an international cooperative study BIOMOVS. Two kinds of models have been developed to estimate mercury concentrations in fish after chronic releases into rivers. One uses a bioaccumulation factor approach which is applied to ecosystems in equilibrium, whereas the other is a dynamic model which considers the change of the concentrations in water and the metabolism in fish. The success of the models tested by three different scenarios depended upon whether mercury was in equilibrium in the environment. For the scenario where mercury concentrations reached equilibrium, the first model performed satisfactorily. For the scenario where equilibrium was not attained, the first model was not adequate but the second model could predict more accurately. The limitations of applications were suggested for the two models employed here. (author)

  5. 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. PMID:24952970

  6. 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.

  7. 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

    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...

  8. 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)

  9. 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.

  10. Spatial extent and dynamics of dam impacts on tropical island freshwater fish assemblages

    Science.gov (United States)

    Cooney, Patrick B.; Kwak, Thomas J.

    2013-01-01

    Habitat connectivity is vital to the persistence of migratory fishes. Native tropical island stream fish assemblages composed of diadromous species require intact corridors between ocean and riverine habitats. High dams block fish migration, but low-head artificial barriers are more widespread and are rarely assessed for impacts. Among all 46 drainages in Puerto Rico, we identified and surveyed 335 artificial barriers that hinder fish migration to 74.5% of the upstream habitat. We also surveyed occupancy of native diadromous fishes (Anguillidae, Eleotridae, Gobiidae, and Mugilidae) in 118 river reaches. Occupancy models demonstrated that barriers 2 meters (m) high restricted nongoby fish migration and extirpated those fish upstream of 4-m barriers. Gobies are adapted to climbing and are restricted by 12-m barriers and extirpated upstream of 32-m barriers. Our findings quantitatively illustrate the extensive impact of low-head structures on island stream fauna and provide guidance for natural resource management, habitat restoration, and water development strategies.

  11. Fish communities in coastal freshwater ecosystems: the role of the physical and chemical setting

    Directory of Open Access Journals (Sweden)

    Arend Kristin K

    2008-12-01

    Full Text Available 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 phosphorus load, embayment area, and submerged vegetation, to differences in fish species diversity and community relative abundance, biomass, and size structure both among and within embayments. Yellow perch (Perca flavescens and centrarchids numerically dominated most embayment fish communities. Biomass was dominated by piscivorous fishes including brown bullhead (Ameiurus nebulosus, bowfin (Amia calva, and northern pike (Esox lucius. Phosphorus loading influenced relative biomass, but not species diversity or relative abundance. Fish relative abundance differed among embayments; within embayments, fish abundance at individual sampling stations increased significantly with submerged vegetative cover. Relative biomass differed among embayments and was positively related to total phophorus loading and embayment area. Fish community size structure, based on size spectra analysis, differed among embayments, with the frequency of smaller-bodied fishes positively related to percent vegetation. Conclusion The importance of total phosphorus loading and vegetation in structuring fish communities has implications for anthropogenic impacts to embayment fish communities through activities such as farming and residential development, reduction of cultural eutrophication, and shoreline development and maintenance.

  12. Leptospira infections in freshwater fish in Morogoro Tanzania: a hidden public health threat.

    Science.gov (United States)

    Mgode, Georgis F; Mhamphi, Ginethon G; Katkweba, Abdul S; Thomas, Michael

    2014-04-01

    Leptospirosis caused by spirochete bacterium of genus Leptospira affects humans and animals worldwide. Rodents are major reservoirs of leptospires whereas wetland and aquatic migratory birds also carry and transmit leptospires. Leptospirosis studies in fish are lacking in African countries despite favourable environment and abundant reservoirs, which can spread leptospires into aquatic habitats and infect fish. The objectives of this study were to determine presence of Leptospira in fish; the prevalent Leptospira serovars and whether are related to serovars reported in animals; and to ascertain potential public health risk. Live tilapia, catfish and eel fish (n = 48) were caught in Mindu Dam in Morogoro Municipality in eastern Tanzania. Blood sample was collected using syringes and needles to obtain serum for serological detection of leptospirosis using gold standard microagglutination test utilizing local and reference Leptospira serovars Sokoine, Kenya, Pomona and Hebdomadis. Twenty-six fish (54.2%) were positive for serovar Kenya (29.2%) and Sokoine (25%). Leptospira prevalence was high in both catfish (58.3%) and tilapia fish (47.8%). Thus, different fish types are infected with Leptospira found in animals. Fish could be source of Leptospira infection to humans since tilapia and catfish are the common fish type widely consumed in Tanzania. Further study covering lakes, rivers and dams is required to better understand the prevalence of Leptospira in fish and actual public health threats. PMID:26875305

  13. Survey of parasitic fauna of different ornamental freshwater fish species in Iran.

    Science.gov (United States)

    Adel, Milad; Ghasempour, Fatemeh; Azizi, Hamid Reza; Shateri, Mohamad Hadi; Safian, Ahmad Reza

    2015-01-01

    Parasitic diseases are harmful and limiting factors in breeding and rearing ornamental fish industry. In this study, 400 apparently healthy ornamental fishes from five species (each species 80 specimens) including: Goldfish (Carassius auratus), guppy (Poecilia reticulate), angelfish (Pterophyllum scalare), discus (Symphsodon discus) and sailfin mollies (Poecilia latipinna) was obtained from a local ornamental fish farm in the north of Iran during 2011 to 2012. The primary purpose of this study was to determine the parasitic infections of aquarium fish in Iran. For this purpose, fish were first examined for ectoparasites using wet mount under a light microscope. Then, the alimentary ducts of fish were observed under light and stereo microscope. In survey of different infection rates for different parasitic infections in examining fish: Dactylogyrus sp., Gyrodactylus sp., Ichthyophthirius multifiliis Trichodina reticulata, Capillaria sp. and Lernaea cyprinacea were collected from five species. All five fish species had Monogenea (Gyrodactylidae and Dactylogyridae) in their skins and gills, the highest prevalence was observed in C. auratus and the lowest was in P. scalare and S. discus. Also, Capillaria sp. was reported as a first record from the abdominal cavity of P. scalare in Iran. Our findings revealed that the protozoal infections are very common among aquarium fishes. Although, no gross pathology was observed among infected fishes, but it is likely that in case of any changes in the environment, then parasitic infections could be harmful. PMID:25992255

  14. 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 ...

  15. Traditional pharmacopeia in small scale freshwater fish farms in West Java, Indonesia : an ethnoveterinary approach

    OpenAIRE

    Caruso, Domenico; Lusiastuti, A. M.; Taukhid,; Slembrouck, Jacques; Komarudin, O.; Legendre, Marc

    2013-01-01

    The use of plants for herbal medicine in the Indonesian aquaculture is still poorly known. The present study aimed to provide an inventory of the plants used by fish farmers, establishing their respective ethnobotanic importance and identifying the variables that determine the use and the choice of these plants in fish health management. A survey based on a semi-directive questionnaire was conducted using a representative sample of fish farmers (n = 504 from 176 villages) from the province of...

  16. Bioaccumulation of selenium from coal fly ash and associated environmental hazards in a freshwater fish community

    International Nuclear Information System (INIS)

    Bioaccumulation of Se by fish from Pigeon River and Pigeon Lake, Michigan, which receive inputs of Se from a coal fly-ash disposal facility, was studied to assess potential hazards of Se toxicity to fish and wildlife. Se concentrations in fish from sites receiving Se inputs from fly ash disposal ponds were significantly greater than concentrations in fish from upstream sites, which were near normal background concentrations. Se bioaccumulation differed substantially among fish species, especially in the most contaminated site, where whole-body Se concentrations for the five species analyzed ranged from 1.4 to 3.8 microg/g (wet wt.). The top predator in the community, northern pike (Esox lucius), had Se concentrations less than those in likely prey species. Among lower-order consumers, Se concentrations were greater in limnetic species (spottail shiner, Notropis hudsonius, and yellow perch, Perca flavescens), than in benthic species (white sucker, Catostomus commersoni, and rock bass, Ambloplites rupestris). Se concentrations in tissues of fish from the lower Pigeon River and Pigeon Lake approached, but did not exceed lowest observable effect concentrations (LOAECs) for Se in tissues of sensitive fish species. However, Se concentrations in several fish species exceeded LOAECs for dietary Se exposure of sensitive species of birds and mammals, suggesting that consumption of fish in these areas may pose a hazard to piscivorous wildlife

  17. 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.

  18. 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

  19. 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

  20. Canadian environmental sustainability indicators: highlights 2005

    International Nuclear Information System (INIS)

    Canadians' health and their social and economic well-being are fundamentally linked to the quality of their environment. Recognizing this, in 2004 the Government of Canada committed to establishing national indicators of freshwater quality, air quality and greenhouse gas emissions. The goal of these new indicators is to provide Canadians with more regular and reliable information on the state of their environment and how it is linked with human activity. Canadians need clearly defined environmental indicators - measuring sticks that can track the results that have been achieved through the efforts of governments, industries and individuals to protect and improve the environment. Environment Canada, Statistics Canada and Health Canada are working together to further develop and communicate these indicators. Reflecting the joint responsibility for environmental management in Canada, this effort has benefited from the cooperation and input of the provinces and territories. The indicators are: air quality; greenhouse gas emissions; and, freshwater quality. Air quality tracks Canadians' exposure to ground-level ozone - a key component of smog. The indicator measures one of the most common, harmful air pollutants to which people are exposed. The use of the seasonal average of ozone concentrations reflects the potential for long-term health effects. Greenhouse gas emissions tracks the annual releases of the six greenhouse gases that are the major contributors to climate change. The indicator comes directly from the greenhouse gas inventory report prepared by Environment Canada for the United Nations Framework Convention on Climate Change (UNFCCC) and the Kyoto Protocol. The data are widely used to report on progress toward Canada's Kyoto target for reduced emissions. Freshwater quality reports the status of surface water quality at selected monitoring sites across the country. For this first report, the focus of the indicator is on the protection of aquatic life, such as

  1. Effect of Cadmium Chloride on Histopathological Changes in the Freshwater Fish Ophiocephalus striatus (Channa

    Directory of Open Access Journals (Sweden)

    M.V. Lokhande

    2012-01-01

    Full Text Available Histopathological changes were observed in the gill, liver, stomach and intestine of Ophiocephallus striatus exposed to the cadmium chloride. The fishes were exposed to medinlethal concentration of 0.63 mg L-1 at 96 h. The histopathological change due to the toxicity of cadium chloride in experimental gills of fish observed hypertrophy, destroy of gills lamellae and blood congestion possibly caused the haematological changes in experimental fishes like reduced RBC count, decreased blood hemoglobin and anaemia. In experimental liver of fish observed degenerative changes, necrosis and hypertrophy possibly responsible for biochemical changes like reduced liver glycogen. Hepatocelluar dissociation in experimental fish possibly caused the decreased tissue glycogen and lipid in liver. Degenerative changes (ex., cloudy swelling possibly caused the endocrine dysfunction leads to increases transaminase activities (hypersecretion of SGOT and SGPT in present study of haematological study. In experimental stomach of fish hyperchromasia, disintegration of epithelium duct and desquamation of gastric mucosa is observed. Desquamation is a postmortem autolysis which indicates the extremely severe harmful effect of cadmium on the stomach of fish. In experimental intestine of fish degenerative changes in the tips of villi like hydropic degeneration, cloudy swelling and necrosis is observed the histological changes is possibly due to the fulfillment of extra energy requirement under the toxicity of cadmium chloride.

  2. 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.

  3. 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).

  4. Sodium cyanide induced alteration in the whole animal oxygen consumption and behavioural pattern of freshwater fish Labeo rohita.

    Science.gov (United States)

    David, Muniswamy; Sangeetha, Jeyabalan; Harish, Etigemane R

    2015-03-01

    Sodium cyanide is a common environmental pollutant which is mainly used in many industries such as mining, electroplating, steel manufacturing, pharmaceutical production and other specialized applications including dyes and agricultural products. It enters aquatic environment through effluents from these industries. Static renewal bioassay test has been conducted to determine LC, of sodium cyanide on indigenous freshwater carp, Labeo rohita. The behavioural pattern and oxygen consumption were observed in fish at both lethal and sub lethal concentrations. Labeo rohita in toxic media exhibited irregular and erratic swimming movements, hyper excitability, loss of equilibrium and shrinking to the bottom, which may be due to inhibition of cytochrome C oxidase activity and decreased blood pH. The combination of cytotoxic hypoxia with lactate acidosis depresses the central nervous system resulting in respiratory arrest and death. Decrease in oxygen consumption was observed at both lethal and sub lethal concentrations of sodium cyanide. Mortality was insignificant at sub lethal concentration test when fishes were found under stress. Consequence of impaired oxidative metabolism and elevated physiological response by fish against sodium cyanide stress showed alteration in respiratory rate. PMID:25895263

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

    Science.gov (United States)

    Díaz, Juan; Villanova, Gabriela Vanina; 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

  6. 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). PMID:23365511

  7. Levels, Distribution, and Health Risks of Polycyclic Aromatic Hydrocarbons in Four Freshwater Edible Fish Species from the Beijing Market

    Directory of Open Access Journals (Sweden)

    Wen-Jing Wu

    2012-01-01

    Full Text Available 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.

  8. 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.

  9. 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

  10. 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

  11. 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.

  12. 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.

  13. 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.

  14. 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. PMID:27377236

  15. 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

  16. 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.

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

    International Nuclear Information System (INIS)

    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

  18. 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.

  19. Impact of Triazophos on Ionic Regulation in the Blood of Freshwater Fish, Channa punctatus (Bloch)

    OpenAIRE

    Abdul Naveed; P. Venkateshwarlu; C. Janaiah

    2011-01-01

    The blood of fresh water, edible fish, Channa punctatus (=murrel) was exposed to sub lethal concentration of triazophos for 24, 48, 72 and 96 h to evaluate alterations in the levels of minerals i.e., sodium, potassium, chloride, calcium, inorganic phosphate, magnesium and iron. The increased chloride mineral along with sodium and potassium play an important role in neuromuscular excitability, acid-base balance and increased osmotic pressure of the fish. The decreased calcium is of great impor...

  20. Parasites of South African freshwater fish. VI. Nematode parasites of some fish species in the Kruger National Park.

    Science.gov (United States)

    Boomker, J

    1994-03-01

    The nematode parasites of 30 spot-tailed robbers, Brycinus imberi, five tiger-fish, Hydrocynus vittatus, 77 large-scaled yellowfish. Barbus marequensis, two mudsuckers, Labeo molybdinus, 114 catfish, Clarias gariepinus, 46 silver barbel, Schilbe intermedius, 66 squeakers, Synodontis zambezensis, three eels, Anguilla spp., 83 Mozambique bream, Oreochromis mossambicus, 81 red-breasted bream, Tilapia rendalli swierstrae and 32 large-mouthed bream, Serranochromis meridianus, caught in the Sabie, Crocodile and Olifants Rivers in the southern and central regions of the Kruger National Park, were collected, identified and counted. A single Camallanus sp. male was recovered from one of the mudsuckers; Capillaria spp. from three catfish and one squeaker; philometrid nematodes from two silver barbel, 15 squeakers and a large-mouthed bream; Paracamallanus cyathopharynx from one tiger-fish, 80 catfish, 28 silver barbel and one squeaker; Procamallanus laeviconchus from a single catfish; Rhabdochona esseniae from six large-scaled yellowfish; Rhabdochona versterae from 14 spot-tailed robbers; Rhabdochona spp. from 20 catfish, 17 silver barbel, eight squeakers, two eels, one large-mouthed bream and two red-breasted bream; Raillietnema synodontisi from 33 squeakers; Spinitectus petterae from 37 catfish; Spinitectus zambezensis from 55 squeakers; Spinitectus spp. from one tiger-fish and four silver barbel, and Spirocamallanus daleneae and Synodontisia thelastomoides from 33 and 35 squeakers, respectively.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7898896

  1. 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.

  2. The gut microbiome and degradation enzyme activity of wild freshwater fishes influenced by their trophic levels

    Science.gov (United States)

    Liu, Han; Guo, Xianwu; Gooneratne, Ravi; Lai, Ruifang; Zeng, Cong; Zhan, Fanbin; Wang, Weimin

    2016-01-01

    Vertebrate gut microbiome often underpins the metabolic capability and provides many beneficial effects on their hosts. However, little was known about how host trophic level influences fish gut microbiota and metabolic activity. In this study, more than 985,000 quality-filtered sequences from 24 16S rRNA libraries were obtained and the results revealed distinct compositions and diversities of gut microbiota in four trophic categories. PCoA test showed that gut bacterial communities of carnivorous and herbivorous fishes formed distinctly different clusters in PCoA space. Although fish in different trophic levels shared a large size of OTUs comprising a core microbiota community, at the genus level a strong distinction existed. Cellulose-degrading bacteria Clostridium, Citrobacter and Leptotrichia were dominant in the herbivorous, while Cetobacterium and protease-producing bacteria Halomonas were dominant in the carnivorous. PICRUSt predictions of metagenome function revealed that fishes in different trophic levels affected the metabolic capacity of their gut microbiota. Moreover, cellulase and amylase activities in herbivorous fishes were significantly higher than in the carnivorous, while trypsin activity in the carnivorous was much higher than in the herbivorous. These results indicated that host trophic level influenced the structure and composition of gut microbiota, metabolic capacity and gut content enzyme activity. PMID:27072196

  3. The gut microbiome and degradation enzyme activity of wild freshwater fishes influenced by their trophic levels.

    Science.gov (United States)

    Liu, Han; Guo, Xianwu; Gooneratne, Ravi; Lai, Ruifang; Zeng, Cong; Zhan, Fanbin; Wang, Weimin

    2016-01-01

    Vertebrate gut microbiome often underpins the metabolic capability and provides many beneficial effects on their hosts. However, little was known about how host trophic level influences fish gut microbiota and metabolic activity. In this study, more than 985,000 quality-filtered sequences from 24 16S rRNA libraries were obtained and the results revealed distinct compositions and diversities of gut microbiota in four trophic categories. PCoA test showed that gut bacterial communities of carnivorous and herbivorous fishes formed distinctly different clusters in PCoA space. Although fish in different trophic levels shared a large size of OTUs comprising a core microbiota community, at the genus level a strong distinction existed. Cellulose-degrading bacteria Clostridium, Citrobacter and Leptotrichia were dominant in the herbivorous, while Cetobacterium and protease-producing bacteria Halomonas were dominant in the carnivorous. PICRUSt predictions of metagenome function revealed that fishes in different trophic levels affected the metabolic capacity of their gut microbiota. Moreover, cellulase and amylase activities in herbivorous fishes were significantly higher than in the carnivorous, while trypsin activity in the carnivorous was much higher than in the herbivorous. These results indicated that host trophic level influenced the structure and composition of gut microbiota, metabolic capacity and gut content enzyme activity. PMID:27072196

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

    Science.gov (United States)

    Manek, Aditya K; Ferrari, Maud C O; Chivers, Douglas P; Niyogi, Som

    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. PMID:24914525

  5. Toxicity of perfluorooctane sulfonic acid and perfluorooctanoic acid on freshwater macroinvertebrates (Daphnia magna and Moina macrocopa) and fish (Oryzias latipes).

    Science.gov (United States)

    Ji, Kyunghee; Kim, Younghee; Oh, Sorin; Ahn, Byeongwoo; Jo, Hyunye; Choi, Kyungho

    2008-10-01

    Because of their global distribution, persistence, and tendency to bioaccumulate, concerns about perfluorooctane sulfonic acid (PFOS) and perfluorooctanoic acid (PFOA) are growing. We determined the toxicity of PFOS and PFOA in several freshwater organisms, including two cladocerans, Daphnia magna and Moina macrocopa, and the teleost Oryzias latipes. In general, PFOS is approximately 10 times more toxic than PFOA in these organisms. In M. macrocopa, the median lethal concentration (LC50) was 17.95 mg/L for PFOS and 199.51 mg/L for PFOA. Moina macrocopa exhibited greater sensitivity than D. magna to both perfluorinated compounds in both acute and chronic exposures. In the 48-h acute toxicity test, M. macrocopa was approximately two times more sensitive than D. magna. In the 7-d chronic toxicity test, M. macrocopa showed significant reproductive changes at 0.31 mg/L for PFOS, which was approximately seven times lower than the effect concentrations observed over the 21-d exposure in D. magna. Two-generation fish toxicity tests showed that parental exposure to both compounds affected the performance of offspring. Unexposed progeny-generation (F1) fish exhibited elevated mortality and histopathological changes that were correlated with exposure in the parental generation (F0). Continuous exposure from F0 through F1 generations increased the extent of adverse effects. Considering the persistent nature of PFOS and PFOA, more research is required to determine potential consequences of long-term exposure to these compounds in aquatic ecosystems. PMID:18593212

  6. 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 acetaminophen-treated fish tissues. The elevated levels of these enzymes were significantly controlled by the treatment of T. 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.

  7. Length-length relationship, length-weight relationship and condition factor of freshwater fish species of Bangladesh

    Directory of Open Access Journals (Sweden)

    M. Manjurul Alam

    2013-09-01

    Full Text Available The objectives of this study were to describe the length-length relationship (LLR, length-weight relationship (LWR and condition factor of four important freshwater fish species Esomus danricus, Amblypharyngodon mola, Pethia ticto and Glossogobius giuris, collected from different fish market of Gomastapur subdistrict, Chapai Nawabganj, Bangladesh from December 2009 to November 2010. Relationship equations among different body length parameters of each species were found highly significant (p 3.01, 0.025 TL3.03, 0.043 TL2.93 and 0.021 TL2.91 for E. danricus, A. mola, P. ticto and G. giuris respectively. The study period was divided into three major seasons summer (March to June, rainy (July to October and winter (November to February for studying the growth and condition of the specimens. The values of the Fulton’s and relative condition factors indicated apparent growth variation in different seasons. All the species showed maximum robustness in summer and rainy seasons. The information obtained from this study will be helpful for the fishery managers to implement adequate adaption-centric regulations for sustainable fishery management in the water bodies of Gomastapur as well as the other parts of the country.

  8. Size-selective feeding on phytoplankton by two morpho-groups of the small freshwater fish Amblypharyngodon mola.

    Science.gov (United States)

    Nandi, S; Saikia, S K

    2015-08-01

    Two morpho-groups (i.e., small, MGS and big, MGL) of the small freshwater fish Amblypharyngodon mola were studied for their feeding behaviour in the natural environment. Both the morpho-groups fed on a variety of phytoplankton including Cyanophyceae, Chlorophyceae, Bacillariophyceae and Euglenophyceae. The fish had more Chlorophyceae and Bacillariophyceae in their gut than other phytoplankton. Costello's selectivity plots revealed that the MGS fed on the smaller phytoplankters (2-6 µm in size), whereas the MGL fed on both the small and large (up to 12 µm in size) phytoplankters. The differences in mouth areas between the two morpho-groups were explained as a possible reason of size-selective feeding and contribute to overcome gape limitation in A. mola. This is further accompanied by the uniform pore size of the gills (2 µm) in all the morpho-groups. This study concluded that A. mola exhibits a size-dependent feeding strategy regulated by gape limitation at the ingestion level. With ontogenetic shifts, flexibility appears to overcome such a limitation in the MGL, having a wider mouth area supported by jaw opening ability. PMID:26084383

  9. Impact of Triazophos on Ionic Regulation in the Blood of Freshwater Fish, Channa punctatus (Bloch

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    Abdul Naveed

    2011-08-01

    Full Text Available The blood of fresh water, edible fish, Channa punctatus (=murrel was exposed to sub lethal concentration of triazophos for 24, 48, 72 and 96 h to evaluate alterations in the levels of minerals i.e., sodium, potassium, chloride, calcium, inorganic phosphate, magnesium and iron. The increased chloride mineral along with sodium and potassium play an important role in neuromuscular excitability, acid-base balance and increased osmotic pressure of the fish. The decreased calcium is of great importance in blood coagulation, muscle contraction and nerve transmission while decreased iron is an essential constituent of heame in hemoglobin of the fish. The increased magnesium participates in principal metabolic activities, in formation of bones and teeth. Inorganic phosphate acts as a major buffer and is the basis of energy exchange. Triazophos altered the activities of the macro minerals in C. punctatus during stress periods.

  10. Bioaccumulation of heavy metals in fish tissues of a freshwater lake of Bhopal.

    Science.gov (United States)

    Malik, Neetu; Biswas, A K; Qureshi, T A; Borana, K; Virha, Rachna

    2010-01-01

    Contamination of heavy metals, namely, lead, cadmium, zinc, nickel, copper, chromium and mercury was evaluated in the samples of water and tissues of Labeo rohita and Ctenopharyngodon idella of Upper Lake of Bhopal collected during summer, rainy and winter seasons of 2005-2006. Different organs of the fishes accumulated varying quantities of different heavy metals. In L. rohita, accumulation of heavy metals was in the sequence liver>kidney>gills>muscles, and in C. idella, it was gills>liver>kidney>muscles. Zn was the highest accumulating metal in fish, whilst Hg was the lowest and was well corroborated with those of water. The values of heavy metals were so far well within the maximum permissible standard value of heavy metals for drinking water and for fish culture as prescribed by various national and international agencies. PMID:19123040

  11. Toxic elements in free-living freshwater fish, water and sediments in Poland

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    Szkoda Józef

    2014-12-01

    Full Text Available Samples for analysis were collected from 10 areas, including the major Polish rivers and lakes, with different sources of environmental pollution (industrial, municipal, and farming. The materials was taken from the lakes of Mazury, located in a non-industrialised region, from the Brda River, an area impacted by pig farms, from the lakes of Lipczyno Wielkie/Pomerania, from the Wkra River, an area impacted by poultry farms, from the Dunajec River at the Roznowski Reservoir, from the Vistula River at Cracow and Warsaw, from the Odra River at Wroclaw and the Warta River estuary, and also from Rybnik Power Station Reservoir. Concentrations of Pb, Cd, Hg, and As were analysed in 397 fish muscle and 128 sediment samples using an atomic absorption spectrometry technique. The analytical procedures were covered by a quality assurance programme. It was demonstrated that the average concentrations of lead, cadmium, and arsenic in fish were in the low hundredths and thousandths of a mg/kg and never exceeded permitted limits established for food. Higher values of these elements were found in fish from bodies of water located in the zone of influence of large urban agglomerations, especially the Cracow region. High concentrations of lead and cadmium were also found in Vistula River sediments near Cracow, where the maximum values were 134.10 mg/kg and 21.24 mg/kg dry weight for lead and cadmium respectively. The average concentration of mercury in a predatory fish muscle (0.179 mg/kg was almost twice as high as in the omnivorous fish (0.103 mg/kg. Only a single fish sample exceeded the maximum limit for this metal (0.50 mg/kg and did not present a risk to consumers’ health.

  12. Fixed and flexible: coexistence of obligate and facultative migratory strategies in a freshwater fish

    DEFF Research Database (Denmark)

    Brodersen, Jakob; Chapman, Ben B.; Nilsson, P. Anders;

    2014-01-01

    influence, dictating individual consistency in migratory patterns. Unfortunately, field tests of individual consistency compared to the importance of individual condition on migratory propensity are rare. Here we analyse 6 years of field data on roach migration, gathered by tagging almost 3000 individual...... fish and monitoring their seasonal migrations over extended periods of time. Our aims were to provide a field test of the role of condition in wild fish for migratory decisions, and also to assess individual consistency in migratory tendency. Our analyses reveal that (1) migratory strategy, in terms...

  13. Evaluation of acute toxicity of copper cyanide to freshwater fish, Catla catla (Hamilton

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    Hosetti BASALING

    2011-07-01

    Full Text Available The acute toxicity of copper cyanide to the juveniles of Indian major carp Catla catla (2±0.5 cm was evaluated under static renewal conditions. The concentrations of copper cyanide that killed 50% of the carp fingerlings within 96-h (96-h LC50 was found to be 0.76 ± 0.04 mg/L. Fishes exhibited abnormal swimming activity, followed by frequent gill flapping, loss of equilibrium, gulping of air, hyperactivity, convolutions. The respiratory rate of the fish got severely affected (-63.41%± 0.002 when exposed to copper cyanide.

  14. Freshwater fish's spatial patterns in isolated water springs in North-eastern Mexico

    OpenAIRE

    Jorge Palacio-Núñez; José R. Verdú; Catherine Numa; Daniel Jiménez-García; Genaro Olmos Oropeza; Eduardo Galante

    2010-01-01

    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 ...

  15. 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.

  16. 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.

  17. Freshwater fish as a dietary source of vitamin A in Cambodia

    DEFF Research Database (Denmark)

    Roos, Nanna; Chamnan, Chhoun; Loeung, Deap;

    2007-01-01

    Vitamin A deficiency is a public health problem among children and women. Common Cambodian fish species were sampled and screened for vitamin A content. Contents of vitamin A-active compounds (all-trans retinol, all-trans dehydroretinol, 13-cis retinol, 13-cis dehydroretinol and P-carotene) were ...... by Brouwer et al. [Brouwer, I. A., Dusseldorp, M. V., West, C. E., & Steegers-Theunissen, R. P. M. (2001). Bioavailability and bioefficacy of folate and folic acid in man. Nutrition Research Review, 14, 267-293]).......Vitamin A deficiency is a public health problem among children and women. Common Cambodian fish species were sampled and screened for vitamin A content. Contents of vitamin A-active compounds (all-trans retinol, all-trans dehydroretinol, 13-cis retinol, 13-cis dehydroretinol and P-carotene) were...... 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...

  18. Devicyprin induced gonadal impairment in a freshwater food fish, Channa punctatus (Bloch).

    Science.gov (United States)

    Srivastava, Rajesh K; Yadav, Kamlesh K; Trivedi, Sunil P

    2008-03-01

    Synthetic pyrethroids are the recent major class of broad spectrum, photostable, organic insecticides used in agricultural, domestic and veterinary applications and now account for more than 30% of global insecticide use. Cypermethrin is metabolized and eliminated significantly more slowly by fish than by mammals or birds, which may explain this compound's high toxicity in fish compared to other organisms. The present communication deals with histoanatomical alterations in the gonads of a local fresh water food fish, Channa punctatus exposed to 0.033 ppm (96 hr LC50 X 1/10) concentration of a synthetic pyrethroid, devicyprin (cypermethrin 25%) in aquatic medium of aged tap water for 15, 30 and 45 days respectively. In testis, exposure dependent histological damage has been observed in terms of vacuolization, condensation of spermatogonic cells, distortion of tubular epithelium, shrinkage of interstitial cells and general inflammatory responses. Longest exposure of 45 days has resulted in peculiar starry-sky appearance of the testicular tissue. Gross histo-anatomy of ovarian tissue reveals epithelial lesions, inflammatory responses, stromal hemorrhage, increased interstitium and shrinkage of yolk vesicles towards periphery These findings are quite suggestive of reproductive impairments leading to delayed gonadal maturity and adversely affecting processes of sperm production and ovulation and thus, the fish production. PMID:18831372

  19. 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

    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...

  20. Heavy metals: confounding factors in the response of New Zealand freshwater fish assemblages to natural and anthropogenic acidity.

    Science.gov (United States)

    Greig, Hamish S; Niyogi, Dev K; Hogsden, Kristy L; Jellyman, Phillip G; Harding, Jon S

    2010-07-15

    Acidification of freshwaters is a global phenomenon, occurring both through natural leaching of organic acids and through human activities from industrial emissions and mining. The West Coast of the South Island, New Zealand, has both naturally acidic and acid mine drainage (AMD) streams enabling us to investigate the response of fish communities to a gradient of acidity in the presence and absence of additional stressors such as elevated concentrations of heavy metals. We surveyed a total of 42 streams ranging from highly acidic (pH 3.1) and high in heavy metals (10 mg L(-)(1) Fe; 38 mg L(-)(1) Al) to circum-neutral (pH 8.1) and low in metals (0.02 mg L(-)(1) Fe; 0.05 mg L(-)(1) Al). Marked differences in pH and metal tolerances were observed among the 15 species that we recorded. Five Galaxias species, Anguilla dieffenbachii and Anguillaaustralis were found in more acidic waters (pH2.7 mg L(-)(1) and nine taxa were only found in streams with metal concentrations <1 mg L(-)(1). The importance of heavy metals as critical drivers of fish communities has not been previously reported in New Zealand, although the mechanism of the metal effects warrants further study. Our findings indicate that any remediation of AMD streams which seeks to enable fish recolonisation should aim to improve water quality by raising pH above approximately 4.5 and reducing concentrations of dissolved Al and Fe to <1.0 mg L(-)(1). PMID:20478612

  1. 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

  2. Volatile dimethylsiloxanes in market seafood and freshwater fish from the Xúquer River, Spain.

    Science.gov (United States)

    Sanchís, Josep; Llorca, Marta; Picó, Yolanda; Farré, Marinella; Barceló, Damià

    2016-03-01

    Volatile dimethylsiloxanes are a family of synthetic organosilicon-compounds, which have received rising attention because of their widespread use and occurrence in the environment. In the present work, an analytical method based on ultrasound-assisted solid-liquid extraction (USAE) followed by gas chromatography coupled to tandem mass spectrometry (GC-MS/MS) has been optimized and applied to assess the presence of eight volatile dimethyl siloxanes (VMS) (hexamethylcyclotrisiloxane (D3), octamethylcyclotetra-siloxane (D4), decamethylcyclopentasiloxane (D5), dodecamethylcyclohexasiloxane (D6), octamethyltrisiloxane (MDM), decamethyltetrasiloxane (MD2M) and dodecamethylpentasiloxane (MD3M) and tetradecamethylhexasiloxane (MD4M)) in fish. The optimized method presented limits of quantification between 0.1 and 1.3 pg/g for linear volatile dimethylsiloxanes (lVMS) and between 13 and 39 pg/g for cyclic volatile dimethylsiloxanes (cVMS) and intraday relative standard deviation (between 1.9 and 7.0%). Recovery yields were between 71 and 92%. 40 fish samples collected in different markets in Barcelona, (Spain), and 16 samples of fish directly collected at the Xúquer River were analysed. cVMS were detected in almost all the river fish samples at concentrations between pg/g and ng/g, with a significant correlation between the fat content and VMS concentrations in fish. In addition, significant higher concentrations were found in market samples, suggesting sources of contamination from their manipulation and storage in indoor environments. Multivariate analyses were applied to the results and the siloxane profiles and analyte correlations are discussed. PMID:26747987

  3. Parasites of South African freshwater fish. VII. Nematodes of some scaled fishes from the Hartbeespoort Dam, Transvaal.

    Science.gov (United States)

    Boomker, J

    1994-06-01

    The nematode parasites of 16 large-scaled yellowfish, Barbus marequensis, six silverfish, Barbus mattozi, six small-scaled yellowfish, Barbus polylepis, 52 canary kurper, Chetia flaviventris, 11 carp, Cyprinus carpio, 45 Mozambique bream, Oreochromis mossambicus and a single-banded bream, Tilapia sparrmani, caught in the Hartbeespoort Dam, Transvaal, were collected, identified and counted. Contracaecum spp. larvae were recovered from one O. mossambicus, 40 Chetia flaviventris, three Cyprinus carpio, one B. marequensis and five B. mattozi, Rhabdochona esseniae from five B. marequensis, Rhabdochona spp. from one O. mossambicus and four Cyprinus carpio, and unidentified nematode larvae from two O. mossambicus, three Chetia flaviventris, two Cyprinus carpio and from the single T. sparrmani. Burdens in the infected fishes were generally small, and small-scaled yellowfish did not harbour any worms. Only Mozambique bream and canary kurper were caught at regular intervals, but even in these species no pattern of seasonal prevalence of the nematodes was evident. PMID:7596571

  4. Using ecological-niche modeling as a conservation tool for freshwater species: live-bearing fishes in central Mexico.

    Science.gov (United States)

    Domínguez-Domínguez, Omar; Martínez-Meyer, Enrique; Zambrano, Luis; De León, Gerardo Pérez-Ponce

    2006-12-01

    Ecological-niche modeling is an important tool for conservation assessment of terrestrial species; however, its applicability has been poorly explored in the aquatic realm. Goodeines are a monophyletic group of viviparous freshwater fishes that are well known in central Mexico, with 41 species in 19 genera. Given the number of threats to biodiversity in the region, goodeines represent an excellent model with which to test novel conservation approaches. We assessed the conservation status of the goodeines (37 species), based on their potential distributions predicted by ecological-niche models generated with the genetic algorithm for rule-set prediction (GARP). Predictions of species' distributions performed well in six out of eight species for which sufficient information was available to perform estimations of the area under the curve (AUC) in receiver operating characteristic plots. Extensive field surveys conducted in recent years in most cases confirm the models' predictions. Species richness exhibited a nested pattern, in which the number of species increased toward the center of the distribution of the group. At the basin level, the Río Ameca Basin had the highest number of species (11), chiefly because of the high number of microendemic species (6). Human activities within water bodies (e.g., extensive aquaculture) and drainages (e.g., agriculture, ranching, industrial activities) have affected most goodeines severely, given the deleterious effects of pollution and introductions of exotic species, such as carp (Cyprinus carpio, Ctenopharingodon idella) and tilapia (Oreochromis spp.). Our results paint a pessimistic picture for the long-term survival of many goodeines in their natural environment, and realistic conservation measures are complex and would require immediate protection of specific areas that we have identified. Ecological-niche modeling is a suitable tool for conservation assessment of freshwater species, but availability of environmental

  5. 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. PMID:22693638

  6. Morphological and neurotoxicological findings in tropical freshwater fish (Astyanax sp.) after waterborne and acute exposure to water soluble fraction (WSF) of crude oil.

    Science.gov (United States)

    Akaishi, F M; de Assis, H C Silva; Jakobi, S C G; Eiras-Stofella, D R; St-Jean, S D; Courtenay, S C; Lima, E F; Wagener, A L R; Scofield, A L; Ribeiro, C A Oliveira

    2004-02-01

    The water-soluble fraction (WSF) of crude oil is a complex highly volatile and toxic mixture of hydrocarbon chains (polyaromatics, heterocyclics), phenols, and heterocyclic compounds containing nitrogen and sulfur. To evaluate the toxic effects of WSF in tropical freshwater teleosts and to develop methodologies that could investigate the toxic mechanisms of WSF in tropical organisms, an acute toxicity experiment was conducted with Astyanax sp. Three dilutions (15%, 33%, and 50%) of WSF obtained from Campos Bay's crude oil (Brazil) were used to study morphological and biochemical responses of the fish. Prior to exposure, the distribution and rate of volatilization of the WSF into each aquarium for the same exposure period was quantified by spectrofluorimetry. Five individuals of Astyvanax sp. were exposed to duplicate WSF of 0, 15, 33, and 50% for each of 12-, 24-, and 96-h exposures for a total of 120 individuals. Liver and gills were sampled from five fish from each treatment and were analyzed by histology, scanning and transmission electron microscopy. A fragment of muscle was also collected from each fish to measure acetylcholinesterase activity. Water analysis showed that only 4 h after dilution, an important loss of hydrocarbons in 33% and 50% of WSF was observed. In addition, 50% of hydrocarbon mass was lost in all tested dilutions after 24 h with significant difference for the 50% WSF at all measured times, demonstrating the high volatility of WSF in freshwater. Damage in the liver and the gills included the presence of necrosis, loss of hepatocytes limit, inflammation areas, cellular proliferation, aneurysms, and disorganization of the second lamellae. The 33% WSF significantly reduced acetylcholinesterase activity in fish. Our study demonstrated that the WSF of crude oil caused damage in organs and tissues of tropical freshwater Astyanax sp. and provided also the basis for a better understanding of the toxic mechanisms of WSF in freshwater fishes. PMID

  7. 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.

  8. 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.

  9. Trichodina colisae (Ciliophora: Trichodinidae): new parasite records for two freshwater fish species farmed in Brazil.

    Science.gov (United States)

    Jerônimo, Gabriela Tomas; Marchiori, Natália da Costa; Pádua, Santiago Benites de; Dias Neto, José; Pilarski, Fabiana; Ishikawa, Márcia Mayumi; Martins, Maurício Laterça

    2012-01-01

    Family Trichodinidae comprises ciliate protozoa distributed worldwide; they are considered some of the main parasitological agents infecting cultivated fish. However, the trichodinidae parasitizing important fish species cultured in Brazil are unknown, and more taxonomic studies on this group of parasites are required. This research morphologically characterizes Trichodina colisae Asmat & Sultana, (2005) of pacu (Piaractus mesopotamicus) and patinga hybrid (P. mesopotamicus × P. brachypomus) cultivated in the central and southeast regions of the country. Fresh assemblies were made from mucus scraped from the skin, fins and gills, fixed with methanol and, subsequently, impregnated with silver nitrate and stained with Giemsa for assessment under light microscopy. This research reports not only the second occurrence of T. colisae in the world, but also its first occurrence in South America. PMID:23207983

  10. 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.

  11. Genotoxic Effects of Chlorpyrifos in Freshwater Fish Cirrhinus mrigala Using Micronucleus Assay

    OpenAIRE

    Anita Bhatnagar; Abhay Singh Yadav; Navneet Cheema

    2016-01-01

    The genotoxicity of pesticides is an issue of worldwide concern and chlorpyrifos is one of the largest selling organophosphate agrochemicals that has been widely detected in surface waters of India. The studies on long term genotoxic biomarkers are limited; therefore, present study was carried out to analyze the incidence of nuclear anomalies in the blood cells of fresh water fish Cirrhinus mrigala using micronucleus (MN) assay as a potential tool for assessment of genotoxicity. Acute toxicit...

  12. TOXICITY OF ZINC ON THE BIOCHEMICAL CONTENTS OF CERTAIN TISSUES OF FRESHWATER FISH, CHANNA GACHUA (HAM.)

    OpenAIRE

    Kawade S. J; Khillare Y. K

    2012-01-01

    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.

  13. 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.

  14. Radioactivity of surface water and freshwater fish in Finland in 1988-1990

    International Nuclear Information System (INIS)

    Changes over time in the activity concentrations of radionuclides in surface water and in the five largest rivers and some smaller rivers discharging into the Baltic Sea were monitored in 1988-1990. The dominant gamma-emitting radionuclides were 137Cs and 134Cs. The effect of the uneven distribution of Chernobyl deposition is still seen in the results. The activity concentrations of 137Cs in surface water have decreased significantly: In the drainage area where the activity concentrations were highest after the Chernobyl accident, the concentrations in October 1990 were only about 1-4% of the maximum values in May 1986. The decrease in the activity concentrations of 90Sr was much slighter. The study of areal and temporal changes in the activity concentrations of 137Cs in fish, started in 1986, continued in 1988-1990. In all, about 2400 fish samples from southern and middle Finland (excluding Lappland) were analyzed gammaspectrometrially during these three years. Seventeen different fish species were included in the study. (20 refs., 14 figs., 30 tabs.)

  15. 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.).

  16. Conversion of carotenoids into vitamins A(1) and A(2) in two species of freshwater fish.

    Science.gov (United States)

    Gross, J; Budowski, P

    1966-12-01

    1. Examination of two zooplankton species predominating in fish ponds, Daphnia magna and Chironomus larvae, revealed the presence of alpha- and beta-carotene, echinenone, canthaxanthin and 3-hydroxy-4-oxo-beta-carotene in Daphnia, and beta-carotene and cryptoxanthin ester in Chironomus. No specific provitamins A(2) (containing a 3,4-dehydro-beta-ionone ring) were detected. 2. Guppies (Lebistes reticulatus) and platies (Xiphophorus variatus) were found to form vitamin A from beta-carotene and from its oxygen-containing derivatives isozeaxanthin, canthaxanthin and astaxanthin. Slight conversion into vitamin A(2) seemed to occur simultaneously. 3,4-Dehydro-3'-hydroxy-beta-carotene formed little vitamin A, and the latter was mainly of the A(2) type. Lutein was devoid of provitamin A properties. 3. In addition to vitamin A, beta-carotene was detected in fish receiving the 4-oxo- and 4-hydroxy-carotenoids. A reaction scheme for the conversion of carotenoids into retinal and and 3,4-dehydroretinal is presented. 4. It is concluded that natural 4-oxo derivatives of beta-carotene may play a significant role as vitamin A precursors for fish. PMID:16742455

  17. Conversion of carotenoids into vitamins A1 and A2 in two species of freshwater fish

    Science.gov (United States)

    Gross, Jeana; Budowski, P.

    1966-01-01

    1. Examination of two zooplankton species predominating in fish ponds, Daphnia magna and Chironomus larvae, revealed the presence of α- and β-carotene, echinenone, canthaxanthin and 3-hydroxy-4-oxo-β-carotene in Daphnia, and β-carotene and cryptoxanthin ester in Chironomus. No specific provitamins A2 (containing a 3,4-dehydro-β-ionone ring) were detected. 2. Guppies (Lebistes reticulatus) and platies (Xiphophorus variatus) were found to form vitamin A from β-carotene and from its oxygen-containing derivatives isozeaxanthin, canthaxanthin and astaxanthin. Slight conversion into vitamin A2 seemed to occur simultaneously. 3,4-Dehydro-3′-hydroxy-β-carotene formed little vitamin A, and the latter was mainly of the A2 type. Lutein was devoid of provitamin A properties. 3. In addition to vitamin A, β-carotene was detected in fish receiving the 4-oxo- and 4-hydroxy-carotenoids. A reaction scheme for the conversion of carotenoids into retinal and and 3,4-dehydroretinal is presented. 4. It is concluded that natural 4-oxo derivatives of β-carotene may play a significant role as vitamin A precursors for fish. PMID:16742455

  18. 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

  19. 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. PMID:20411732

  20. Behavioral Responses of the Freshwater Fish, Cyprinus carpio (Linnaeus) Following Sublethal Exposure to Chlorpyrifos

    OpenAIRE

    Halappa, Ramesh; David, Muniswamy

    2009-01-01

    Common carp fingerlings were exposed to different concentrations (0.120 to 0.200 mg/L) of an organophosphate pesticide, chlorpyrifos (20% EC) for 96 h. The acute toxicity (LC50) of chlorpyrifos by static renewal (semi-static) bioassay test was found to be 0.160 mg/L. One-seventh (0.0224 mg/L) and one-fourteenth (0.0112 mg/L) of the 96 h LC50 were selected as sublethal concentrations for subacute studies. The fish were exposed to both the sublethal concentrations for 1, 7 and 14 days and allow...

  1. 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).

  2. 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.

  3. 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.

  4. Out-of-season sperm cryopreserved in different media of the Amazonian freshwater fish pirapitinga (Piaractus brachypomus).

    Science.gov (United States)

    Nascimento, A F; Maria, A N; Pessoa, N O; Carvalho, M A M; Viveiros, A T M

    2010-04-01

    The pirapitinga (Piaractus brachypomus) is a freshwater fish that inhabits the Amazon and Orinoco River basins. The use of cryopreserved sperm has been considered to facilitate procedures during the artificial reproduction. The aim of the present study was to develop a freezing protocol for pirapitinga sperm collected outside the spawning season. Sperm samples were diluted in four freezing media prepared by a combination of two extenders (glucose and BTS-Beltsville Thawing Solution) and two cryoprotectant agents (DMSO and methylglycol) loaded into 0.5-mL straws, frozen in a nitrogen-vapor shipping dewar (dry-shipper) and stored in liquid nitrogen at -196 degrees C. Post-thaw sperm motility was evaluated both subjectively using a light microscope and by a computer-assisted sperm analyzer (CASA). Curvilinear, average path and straight-line velocities were also determined. There were no differences (P>0.05) in post-thaw sperm motility between evaluations performed subjectively and using the CASA. Sperm samples cryopreserved in glucose-methylglycol yielded the greatest post-thaw sperm motility (81%) and fastest sperm velocities when compared to the samples frozen in the other three media (P<0.05). Out-of-season sperm cryopreserved in glucose and methylglycol under the conditions described above is of high quality and can therefore be used to facilitate artificial reproduction procedures, as only females will need handling for hormonal induction and gamete collection during the spawning season. Although the CASA system provides precise data on sperm motility, the subjective evaluation is practical and can be conducted by well-trained personnel at commercial fish farms as an acceptable evaluation of sperm quality. PMID:19679412

  5. 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.

  6. On two new species of the genus Cornudescoides Kulkarni, 1969 (Monogenea: Ancyrocephalinae) from a freshwater fish Mystus vittatus from Meerut (U.P.), India

    OpenAIRE

    Rastogi, Pragati; Mishra, Deepmala; Singh, Jyoti; Rani, Kavita

    2011-01-01

    During study of freshwater monogeneans of Meerut region, we came across five infected specimen of fish Mystus vittatus, infected with monogeneans belonging to the genus Cornudescoides Kulkarni 1969. On subsequent study, the worms appear new to us and are described here in as such. C. kulkarnii n. sp. is characterized by four pairs of head organs, nut cracker shaped accessory piece of cirrus, capitulum or patches with proximal conical protruberance, longer inner root of dorsal anchor and diffe...

  7. Role of morphometry in determining the feeding success of small freshwater fish species: Multivariate analysis of Amblypharyngodon mola, Puntius ticto, and Esomus danricus

    OpenAIRE

    Nandi Sudarshana; Saikia Surjya Kumar

    2015-01-01

    Factor and multiple regression analysis were used to extract the morphometric variables that contributed to feeding success in three small freshwater fishes. Of the first two factors, factor 1, showed high loading of gut weight (GW), length of the upper (UJ), and lower jaws (LJ) in mola, Amblypharyngodon mola (Hamilton), and GW and vertical mouth opening (VMO) in punti, Puntius ticto (Hamilton). In darikana, Esomus danricus (Hamilton), GW, horizontal mouth opening (HMO), and VMO were highly l...

  8. Application of DNA barcoding for identification of freshwater carnivorous fish diets: Is number of prey items dependent on size class for Micropterus salmoides?

    OpenAIRE

    Jo, Hyunbin; Gim, Jeong-An; Jeong, Kwang-Seuk; Kim, Heui-Soo; Joo, Gea-Jae

    2013-01-01

    Understanding predator–prey interactions is a major challenge in ecological studies. In particular, the accurate identification of prey is a fundamental requirement in elucidating food-web structure. This study took a molecular approach in determining the species identity of consumed prey items of a freshwater carnivorous fish (largemouth bass, Micropterus salmoides), according to their size class. Thirty randomly selected gut samples were categorized into three size classes, based on the tot...

  9. 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.

  10. Genotoxic Effects of Chlorpyrifos in Freshwater Fish Cirrhinus mrigala Using Micronucleus Assay

    Directory of Open Access Journals (Sweden)

    Anita Bhatnagar

    2016-01-01

    Full Text Available The genotoxicity of pesticides is an issue of worldwide concern and chlorpyrifos is one of the largest selling organophosphate agrochemicals that has been widely detected in surface waters of India. The studies on long term genotoxic biomarkers are limited; therefore, present study was carried out to analyze the incidence of nuclear anomalies in the blood cells of fresh water fish Cirrhinus mrigala using micronucleus (MN assay as a potential tool for assessment of genotoxicity. Acute toxicity of chlorpyrifos was evaluated by exposing fingerlings to different doses of chlorpyrifos (1/20, 1/10, and 1/5 of LC50 and LC50 was calculated as 0.44 mg L−1 using probit analysis. Blood samples were taken on days 2, 4, 8, 12, 21, 28, and 35. In general, significant effects for both concentration and duration of exposure were observed in treated fish. It was found that MN induction was highest on day 14 at 0.08 mg L−1 concentration of chlorpyrifos. It was concluded that chlorpyrifos is genotoxic pesticide causing nuclear anomalies in Cirrhinus mrigala.

  11. 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.

  12. 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.

  13. The influence of the Mackenzie River plume on distribution and diversity of marine larval fish assemblages on the Canadian Beaufort Shelf

    Science.gov (United States)

    Wong, Sally; Walkusz, Wojciech; Hanson, Mark; Papst, Michael H.

    2013-11-01

    In the Beaufort Sea, freshwater input from the Mackenzie River creates a relatively warm and turbid plume across the coastal shelf region. To determine the influence of this plume on marine larval fish abundance, distribution, and assemblages, we sampled larval fish during July and August of 2007 using 500 μm bongo nets on transects across the plume gradient at three sampling stations per transect, along with oceanographic measurements. Three larval fish assemblages were identified within three distinct oceanographic zones: intense plume, diffuse plume and oceanic. The intense plume assemblage was dominated by Saffron cod (Eleginus gracilis) and Pacific herring (Clupea pallasii); the diffuse plume assemblage was dominated by the Pricklebacks (sub-family Lumpeninae); and the oceanic assemblage was dominated by Arctic cod (Boreogadus saida). Even though there were differences in relative abundance of particular species among these areas, no significant differences in total abundances of larval fish were found.

  14. 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.

  15. Five new species of Urocleidoides (Monogenoidea) (Mizelle and Price 1964) Kritsky, Thatcher, and Boeger, 1986, parasitizing the gills of Panamanian freshwater fishes.

    Science.gov (United States)

    Mendoza-Franco, Edgar F; Reina, Ruth G

    2008-08-01

    During an investigation of gill monogenoidean parasites from freshwater fishes in central Panama, 5 new species of Urocleidoides (sensu stricto) were found: Urocleidoides cultellus n. sp., Urocleidoides visiofortatus n. sp., and Urocleidoides advenai n. sp. from the gymnotiform Brachyhypopomus occidentalis (Hypopomidae); Urocleidoides neotropicalis n. sp. and Urocleidoides piriatiu n. sp. from the characiforms Saccodon dariensis (Parodontidae) and Ctenolucius beani (Ctenoluciidae), respectively. Our findings represent the first known species of Urocleidoides from these fishes in Central America and demonstrate that they are morphologically linked to their South American congeners. PMID:18837577

  16. Distinct migratory and non-migratory ecotypes of an endemic New Zealand eleotrid (Gobiomorphus cotidianus – implications for incipient speciation in island freshwater fish species

    Directory of Open Access Journals (Sweden)

    Stevens Mark I

    2008-02-01

    Full Text Available Abstract Background Many postglacial lakes contain fish species with distinct ecomorphs. Similar evolutionary scenarios might be acting on evolutionarily young fish communities in lakes of remote islands. One process that drives diversification in island freshwater fish species is the colonization of depauperate freshwater environments by diadromous (migratory taxa, which secondarily lose their migratory behaviour. The loss of migration limits dispersal and gene flow between distant populations, and, therefore, is expected to facilitate local morphological and genetic differentiation. To date, most studies have focused on interspecific relationships among migratory species and their non-migratory sister taxa. We hypothesize that the loss of migration facilitates intraspecific morphological, behavioural, and genetic differentiation between migratory and non-migratory populations of facultatively diadromous taxa, and, hence, incipient speciation of island freshwater fish species. Results Microchemical analyses of otolith isotopes (88Sr, 137Ba and 43Ca differentiated migratory and non-migratory stocks of the New Zealand endemic Gobiomorphus cotidianus McDowall (Eleotridae. Samples were taken from two rivers, one lake and two geographically-separated outgroup locations. Meristic analyses of oculoscapular lateral line canals documented a gradual reduction of these structures in the non-migratory populations. Amplified fragment length polymorphism (AFLP fingerprints revealed considerable genetic isolation between migratory and non-migratory populations. Temporal differences in reproductive timing (migratory = winter spawners, non-migratory = summer spawners; as inferred from gonadosomatic indices provide a prezygotic reproductive isolation mechanism between the two ecotypes. Conclusion This study provides a holistic look at the role of diadromy in incipient speciation of island freshwater fish species. All four analytical approaches (otolith

  17. 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. PMID:21975853

  18. 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.

  19. Cloning and Expression Analysis of Skeletal Myosin Heavy Chain (MYHs Gene from the Most Famous Freshwater Fishes in China-Culter alburnus

    Directory of Open Access Journals (Sweden)

    Kun Wang

    2014-04-01

    Full Text Available Culter alburnus, one of the four most famous freshwater fishes, is a very important freshwater fishing species with high economic value in China. The present study focused on the myosin, major protein in skeletal muscles from Culter alburnus in Xingkai Lake. Two types of the gene encoding Myosin Heavy Chain (MYH, a large subunit of the myosin molecule, were cloned from fast skeletal muscle and defined as MYHa (Genbank ID JX272926 and MYHb (Gen bank ID JX402919. The full-length cDNA clones of MYHa and MYHb consisted of 6003 and 5990 bp, which encoded 1933 and 1930 amino acids, respectively. The total levels of the MYHs were significantly higher with the fish age increase. In comparison to the wild and cultured muscles, From 2 to 6 years old, MYHa gene expression of wild population was significantly lower than the cultured population (p<0.05, else MYHb gene expression of wild population was higher than cultured population. The two kinds of genotype interaction affect meat quality traits. The present study has therefore, revealed a complex pattern of expression of MYH genes in relation to developmental stage and population. Our work provided a novel myosin heavy chain gene sequence in fish biology and the results indicate that the MYH gene and the protein it encodes are important for the growth and development of fish, as well as its muscle characterization.

  20. 淡水鱼病毒性疾病的研究进展%Advances on Viral Disease of Freshwater Fish

    Institute of Scientific and Technical Information of China (English)

    吕文雪; 孟庆峰; 钱爱东; 王伟利

    2012-01-01

    为了更好地预防和治疗淡水鱼病毒病.综述了淡水鱼病毒病的研究情况.主要介绍了锦鲤疱疹病毒病、鲤春病毒血症、传染性胰腺坏死病毒病、传染性造血器官坏死症、病毒性出血性败血症等疾病的流行情况、国内外研究进展、病原学的研究、疾病的诊断与防治、并对淡水鱼病毒病研究中存在的问题进行了分析和探讨.旨在为淡水鱼病毒病的深入研究提供理论基础和科学依据.%In this article, the advances on viral diseases of Freshwater fish, such as Koi herpesvirus disease (KHVD), Spring viraemia of carp (SVC), Infectious pancreatic necrosis (IPN), Infectious haematopoietic necrosis (IHN) and viral hemorrhagic septicemia (VHS), were reviewed for prevention and treatment. The epidemic situation, related domestic and foreign researches, aetiology, diagnosis and prevention were introduced. We analyzed and discussed problems in the researches on virus disease of freshwater fish. The goal was to provide theoretical foundation and scientific accordance in further researches on viral diseases of Freshwater fish.

  1. 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.

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

    DEFF Research Database (Denmark)

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

    2016-01-01

    then partition variation in embryonic phenotypic performance to maternal, paternal, and parental interactions using the Restricted Maximum Likelihood (REML) model. Results showed that paternal, maternal, and the paternal. ×. maternal interaction terms were highly significant for both species; clearly......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...... demonstrating that certain family combinations were more compatible than others. Paternal effects explained 20.24% of the total variance, which was 2-fold higher than the maternal effects (10.73%) in Ide, while paternal effects explained 18.9% of the total variance, which was 15-fold higher than the maternal...

  3. Variable survival across low pH gradients in freshwater fish species.

    Science.gov (United States)

    Jellyman, P G; Harding, J S

    2014-11-01

    A series of 14 day experiments was conducted on five common New Zealand fish species (redfin bully Gobiomorphus huttoni, inanga Galaxias maculatus, brown trout Salmo trutta, longfin eel Anguilla dieffenbachii and koaro Galaxias brevipinnis) to assess the effect of pH on survival and changes in body mass. No species survived in water of pH <4 although there was 100% survival of all adults at pH 4.5, G. maculatus larvae were also tested and had high mortality at this pH. Results suggest that adults are tolerant of low-pH waters; however, successful remediation of anthropogenically acidified streams will require an understanding of the susceptibility to low pH on different life cycle stages. PMID:25230112

  4. Effects of trophic exposure to dexamethasone and diclofenac in freshwater fish.

    Science.gov (United States)

    Guiloski, Izonete Cristina; Ribas, João Luiz Coelho; Pereira, Letícia da Silva; Neves, Ana Paula Perbiche; Silva de Assis, Helena Cristina

    2015-04-01

    Steroidal and non-steroidalanti-inflammatories are pharmaceutical prescribed in human medicine and have the potential to contaminate water and sediments via inputs from sewage treatment plants. Their impacts on humans and ecosystems are emerging issues in environmental health. The aim of the present work was to evaluate the effects of diclofenac and dexamethasone in male fish Hoplias malabaricus after trophic exposure. Fish were fed twice every week with Astyanax sp. submitted to intraperitoneal inoculation with diclofenac (0; 0.2; 2.0 or 20.0 μg/kg) or dexamethasone (0; 0.03; 0.3 or 3.0 μg/kg). After 12 doses, blood was collected for testosterone dosage. The gonad and liver were collected to calculate gonadosomatic (GSI) and hepatosomatic index (HSI). Antioxidants enzymes activity and biotransformation were also evaluated in liver and gonads. In liver, diclofenac caused oxidative stress with increased superoxide dismutase (SOD) and glutathione peroxidase (GPx) activities and lipoperoxidation (LPO). The GST activity was reduced by diclofenac in liver. Trophic exposure of H. malabaricus to dexamethasone caused an increase in antioxidant system (GPx, CAT, GST, and GSH) and LPO in liver. However, it reduced antioxidant system (GPX and GST activities and GSH) in gonads. Both diclofenac and dexamethasone reduced the levels of testosterone, causing impairment to reproduction. Diclofenac reduced HSI at the 0.2 μg/kg, but not GSI. Our results suggest that the anti-inflammatory drugs diclofenac and dexamethasone caused oxidative stress and reduced testosterone levels that can have a negative impact in aquatic organisms. PMID:25645142

  5. 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.

  6. 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.

  7. Contemporary temperature-driven divergence in a Nordic freshwater fish under conditions commonly thought to hinder adaptation

    Directory of Open Access Journals (Sweden)

    Gregersen Finn

    2010-11-01

    Full Text Available Abstract Background Evaluating the limits of adaptation to temperature is important given the IPCC-predicted rise in global temperatures. The rate and scope of evolutionary adaptation can be limited by low genetic diversity, gene flow, and costs associated with adaptive change. Freshwater organisms are physically confined to lakes and rivers, and must therefore deal directly with climate variation and change. In this study, we take advantage of a system characterised by low genetic variation, small population size, gene flow and between-trait trade-offs to study how such conditions affect the ability of a freshwater fish to adapt to climate change. We test for genetically-based differences in developmental traits indicating local adaptation, by conducting a common-garden experiment using embryos and larvae from replicate pairs of sympatric grayling demes that spawn and develop in natural cold and warm water, respectively. These demes have common ancestors from a colonization event 22 generations ago. Consequently, we explore if diversification may occur under severely constraining conditions. Results We found evidence for divergence in ontogenetic rates. The divergence pattern followed adaptation predictions as cold-deme individuals displayed higher growth rates and yolk conversion efficiency than warm-deme individuals at the same temperature. The cold-deme embryos had a higher rate of muscle mass development. Most of the growth- and development differences occurred prior to hatch. The divergence was probably not caused by genetic drift as there was a strong degree of parallelism in the divergence pattern and because phenotypic differentiation (QST was larger than estimated genetic drift levels (microsatellite FST between demes from different temperature groups. We also document that these particular grayling populations cannot develop successfully at temperatures above 12°C, whereas other European populations can, and that increasing the

  8. 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

  9. Enantioselective analysis of non-steroidal anti-inflammatory drugs in freshwater fish based on microextraction with a supramolecular liquid and chiral liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Caballo, Carmen; Sicilia, Maria Dolores; Rubio, Soledad

    2015-06-01

    Toxicity of pharmaceuticals to aquatic biota is still largely unknown, and no research on the stereoselective toxicity of chiral drugs to these organisms has been undertaken to date. Because of the lack of analytical methods available for this purpose, this manuscript deals, for the first time, with the enantioselective analysis of the non-steroidal anti-inflammatory drugs (NSAIDs) ibuprofen, naproxen and ketoprofen in freshwater fish. The method was based on the microextraction of NSAIDs from fish muscle with a supramolecular liquid made up of inverted hexagonal aggregates of decanoic acid, their enantiomeric separation by liquid chromatography onto a (R)-1-naphthylglycine and 3,5-dinitrobenzoic acid stationary phase and quantification by tandem mass spectrometry. Limits of quantitation (LOQs) for NSAID enantiomers were in the range 1.7-3.3 ng g(-1). Absolute recoveries were from 97 to 104 %, which indicated the high extraction efficiency of the supramolecular solvent. Extraction equilibrium conditions were reached after 10 min which permitted fast sample treatment. Relative standard deviations for enantiomers in fish muscle were always below 6 %. Isotopically labelled internal standards were used to compensate for matrix interferences. The method in-house validation was carried out with the Oncorhynchus mykiss species, and it was applied to the determination of NSAID enantiomers in different fortified freshwater fish species (Alburnus alburnus, Lepomis gibbosus, Micropterus salmoides, O. mykiss and Cyprinus carpio). PMID:25869485

  10. Acute effects of tetracycline exposure in the freshwater fish Gambusia holbrooki: antioxidant effects, neurotoxicity and histological alterations.

    Science.gov (United States)

    Nunes, B; Antunes, S C; Gomes, R; Campos, J C; Braga, M R; Ramos, A S; Correia, A T

    2015-02-01

    A large body of evidence was compiled in the recent decades showing a noteworthy increase in the detection of pharmaceutical drugs in aquatic ecosystems. Due to its ubiquitous presence, chemical nature, and practical purpose, this type of contaminant can exert toxic effects in nontarget organisms. Exposure to pharmaceutical drugs can result in adaptive alterations, such as changes in tissues, or in key homeostatic mechanisms, such as antioxidant mechanisms, biochemical/physiological pathways, and cellular damage. These alterations can be monitored to determine the impact of these compounds on exposed aquatic organisms. Among pharmaceutical drugs in the environment, antibiotics are particularly important because they include a variety of substances widely used in medical and veterinary practice, livestock production, and aquaculture. This wide use constitutes a decisive factor contributing for their frequent detection in the aquatic environment. Tetracyclines are the individual antibiotic subclass with the second highest frequency of detection in environmental matrices. The characterization of the potential ecotoxicological effects of tetracycline is a much-required task; to attain this objective, the present study assessed the acute toxic effects of tetracycline in the freshwater fish species Gambusia holbrooki by the determination of histological changes in the gills and liver, changes in antioxidant defense [glutathione S-transferase (GST), catalase (CAT), and lipoperoxidative damage] as well as potential neurotoxicity (acetylcholinesterase activity). The obtained results suggest the existence of a cause-and-effect relationship between the exposure to tetracycline and histological alterations (more specifically in gills) and enzymatic activity (particularly the enzyme CAT in liver and GST in gills) indicating that this compound can exert a pro-oxidative activity. PMID:25475590

  11. 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.

  12. Site-specific water quality criteria for lethal/sublethal protection of freshwater fish exposed to zinc in southern Taiwan.

    Science.gov (United States)

    Chen, Wei-Yu; Chen, Tzu-Yin; Hsieh, Nan-Hung; Ju, Yi-Ting

    2016-09-01

    There were considerable concerns about the zinc (Zn) pollution caused by electroplating, chemical, and computer-related high-tech industrial discharges in Kaohsiung Rivers situated at south Taiwan. There is, however, a lack of site-specific water chemistry based toxicity assessment and little is known about the sublethal toxicity on freshwater fish. This study proposes an integrated framework to link experimental and mechanistic model-based data analysis of lethal and sublethal Zn toxicities for grass carp (Ctenopharyn odon idellus) populations for providing the site-specific Zn water quality threshold in Kaohsiung Rivers. A biotic ligand model (BLM) that relates toxicity impairment of physiological active sites impacted by Zn species was used to elucidate the site-specific water chemistry affecting the bioavailability and biological response of grass carp exposed to Zn. Results indicated that 96-h LC50 for mortality and 28-d EC50 for growth inhibition were 474.7 ± 1.3 (mean ± SE) and 149 ± 23.5 μg L(-1), respectively. Here the BLM-based predicted steady-state LC50s for mortality were 2110.7, 818.2, 1303.6, 563.3, and 497.1 μg L(-1), whereas measured steady-state EC50s for growth inhibition were 726.8, 326.2, 373.4, 193.9, and 170.5 μg L(-1) for the Agongdian, Houling, Love, Fengshan, and Gaoping Rivers, respectively. A positive correlation between Mg(2+) and EC50 values were found in both acute (r = 0.94, p water chemistry data and ecophysiological traits would enhance the predictive capacities to assess the potential effect of metal toxicity posed to aquatic organisms. PMID:27337432

  13. 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.

  14. 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.

  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. Occurrence of Trichodinid Ciliophorans (Ciliophora: Peritrichida) in the freshwater fishes of the river Churni with description of Trichodina glossogobae sp. nov. in West Bengal, India.

    Science.gov (United States)

    Mitra, Amlan Kumar; Bandyopadhyay, Probir K; Gong, Yingchun; Bhowmik, Biplab

    2012-04-01

    Between January 2011 and March 2011 occurrence of trichodinid ciliophorans were studied in the freshwater fishes of the river Churni. The biodiversity survey revealed presence of a new species of the genus Trichodina (Ehrenberg 1830) infesting Glossogobius giuris (Hamilton-Buchanan). Another freshwater fish Labeo bata (Hamilton 1822) were found to be infested with two species of the genus Tripartiella Lom 1959: Tripartiella bulbosa (Davis 1947) Lom 1959 and T. copiosa Lom 1959. Adhesive disc size of the new Trichodina species is small measuring 30.6-46.9 (36.2 ± 3.9) μm in diameter. The centre of the disc is finely granular and transforms into dark when impregnated with silver. The overall prevalence of this species is 15.6% (12/77). Tripartiella bulbosa and T. copiosa are very small sized ciliophorans, measuring 16.7-23.8 (20.6 ± 2.2) μm and 15.2-22.4 (19.7 ± 1.9) μm in diameter, respectively. PMID:23542238

  17. Bioaccumulation and tissue distribution of organochlorine pesticides (OCPs) in freshwater fishes: a case study performed in Poyang Lake, China's largest lake.

    Science.gov (United States)

    Zhao, Zhonghua; Wang, Yuyu; Zhang, Lu; Cai, Yongjiu; Chen, Yuwei

    2014-01-01

    Concentrations and tissue distribution of organochlorine pesticides (OCPs) in different tissues of freshwater fish, silver carp (Hypophthalmichthys molitrix) and bighead carp (Aristichthys nobilis), collected from Poyang Lake, China's largest shallow lake, and were studied. OCPs were detected with the observed concentrations ranging from 280.67 to 1,006.58 ng/g wet weight (ww) for bighead carp and from 67.28 to 930.06 ng/g ww for silver carp. Composition analysis demonstrated OCPs in both fish were from the same polluted environment, and then, the species-specific bioaccumulation might be mainly due to the different fish age as well as the different feeding habits elucidating from the stable carbon (δ(13)C) and nitrogen (δ(15)N) isotope analysis. Tissue distribution indicated that dietary intake was the major exposure route of OCPs for both fish and higher accumulation potency of OCPs by the hepatobiliary-related tissues (such as liver, kidney, bile, and heart). The higher metabolic activities of these tissues elucidating from the higher values of δ(15)N might be the potential-determined factor responsible for the tissue-specific accumulation. PMID:24705949

  18. 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.

  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. Shifts in stable-isotope signatures confirm parasitic relationship of freshwater mussel glochidia attached to host fish

    Science.gov (United States)

    Fritts, Mark W.; Fritts, Andrea K.; Carleton, Scott A.; Bringolf, Robert B.

    2013-01-01

    The parasitic nature of the association between glochidia of unionoidean bivalves and their host fish (i.e. the role of fish hosts in providing nutritional resources to the developing glochidia) is still uncertain. While previous work has provided descriptions of development of glochidia on fish hosts, earlier studies have not explicitly documented the flow of nutrition from the host fish to the juvenile mussel. Therefore, our objective was to use stable isotope analysis to quantitatively document nutrient flow between fish and glochidia. Glochidia were collected from nine adult Lampsilis cardium and used to inoculate Micropterus salmoides(n = 27; three fish per maternal mussel) that produced juvenile mussels for the experiment. Adult mussel tissue samples, glochidia, transformed juvenile mussels and fish gill tissues were analysed for δ15N and δ13C isotope ratios. We used a linear mixing model to estimate the fraction of juvenile mussel tissue derived from the host fish's tissue during attachment. Our analyses indicate a distinct shift in both C and N isotopic ratios from the glochidial stage to the juvenile stage during mussel attachment and development. Linear mixing model analysis indicated that 57.4% of the δ15N in juvenile tissues were obtained from the host fish. This work provides novel evidence that larval unionoideans are true parasites that derive nutrition from host fish during their metamorphosis into the juvenile stage.

  1. Prevalence of zoonotic anisakid nematodes in Inuit-harvested fish and mammals from the eastern Canadian Arctic.

    Science.gov (United States)

    Pufall, Erica L; Jones-Bitton, Andria; McEwen, Scott A; Brown, Tanya M; Edge, Victoria L; Rokicki, Jerzy; Karpiej, Katarzyna; Peregrine, Andrew S; Simard, Manon

    2012-11-01

    Human anisakidosis is a recognized Arctic zoonosis that is directly related to the consumption of traditional Inuit foods, particularly raw fish. The epidemiology of infections with the zoonotic anisakid nematodes Anisakis simplex and Pseudoterranova decipiens was investigated from August 2007 to July 2009 in Inuit-harvested fish and marine mammals from Inuit regions of Nunavik, Nunavut, and Nunatsiavut, Canada. Fish were tested for anisakid larvae using the pepsin-HCl digestion method, and the stomachs or stomach contents of beluga whales, walruses, and three seal species were examined for anisakids. Anisakids were found in seven of eight fish species, as well as in ringed seals (18.2%; 31/170), bearded seals (75.0%; 12/16), and beluga whales (78.9%; 15/19), but not walruses (0%; 0/15). In fish, the odds of being infected with A. simplex and/or P. decipiens was 68.6 (95% confidence interval, 11.6-627.7) times higher in marine fish than in anadromous fish, after adjusting for length of fish. Negative binomial models were created for animal species with large enough sample sizes and parasite prevalence estimates to assess risk factors associated with anisakid abundance. In seals, the only risk factor significantly associated with increasing anisakid abundance was increasing length (p whales, the only significant risk factor was year of capture (p = 0.03). In fish, length was the variable most commonly associated with increased anisakid larval abundance, with longer fish having significantly higher larval abundances than shorter fish of the same species. The presence of A. simplex and P. decipiens in bearded seals, ringed seals, and beluga whales from Inuit hunting grounds suggests that they likely act as definitive hosts for these parasites in these environments. With respect to zoonotic disease risk associated with Inuit country foods, among the species of fish examined, Atlantic tomcod, polar cod, and sculpins represented the greatest risk of foodborne disease

  2. 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.

  3. Distribution of polycyclic aromatic hydrocarbon (PAH) residues in several tissues of edible fishes from the largest freshwater lake in China, Poyang Lake, and associated human health risk assessment.

    Science.gov (United States)

    Zhao, Zhonghua; Zhang, Lu; Cai, Yongjiu; Chen, Yuwei

    2014-06-01

    The residual levels, tissue distribution and human health risk assessment of polycyclic aromatic hydrocarbons (PAHs) in edible fishes, bighead carp (Aristichthys nobilis) and silver carp (Hypophthalmichthys molitrix), from the largest freshwater lake in China, Poyang Lake, were studied. PAH concentrations ranged from 105 to 513ng g(-1)ww and from 53.9 to 401ng g(-1)ww in different tissues of bighead carp and silver carp, respectively. Low molecular weight (LMW) PAHs were the predominant compounds, suggesting the gill-water transfer might be the major exposure route for PAHs in the studied fish species. Tissue distribution indicated that the hepatobiliary system accumulated higher concentrations of PAHs than the extrahepatic tissues with bile being the most predominant tissue for both species. Composition analysis demonstrated that PAHs were from the combined petrogenic and pyrogenic origin, and the gasoline combustion might be the main source. A preliminary evaluation of human health risk using benzo[a]pyrene (BaP) potency equivalent concentration (PEC) as well as the incremental lifetime cancer risk (ILCR) indicated that PAHs in fish would induce potential carcinogenic effects. PMID:24732028

  4. 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...

  5. 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.

  6. Application of DNA barcoding for identification of freshwater carnivorous fish diets: Is number of prey items dependent on size class for Micropterus salmoides?

    Science.gov (United States)

    Jo, Hyunbin; Gim, Jeong-An; Jeong, Kwang-Seuk; Kim, Heui-Soo; Joo, Gea-Jae

    2014-01-01

    Understanding predator-prey interactions is a major challenge in ecological studies. In particular, the accurate identification of prey is a fundamental requirement in elucidating food-web structure. This study took a molecular approach in determining the species identity of consumed prey items of a freshwater carnivorous fish (largemouth bass, Micropterus salmoides), according to their size class. Thirty randomly selected gut samples were categorized into three size classes, based on the total length of the bass. Using the universal primer for the mtDNA cytochrome oxidase I (COI) region, polymerase chain reaction (PCR) amplification was performed on unidentified gut contents and then sequenced after cloning. Two gut samples were completely empty, and DNA materials from 27 of 28 gut samples were successfully amplified by PCR (success rate: 96.4%). Sequence database navigation yielded a total of 308 clones, containing DNA from 26 prey items. They comprised four phyla, including seven classes, 12 orders, and 12 families based on BLAST and BOLD database searches. The results indicate that largemouth bass show selective preferences in prey item consumption as they mature. These results corroborate a hypothesis, presence of ontogenetic diet shift, derived through other methodological approaches. Despite the practical limitations inherent in DNA barcoding analysis, high-resolution (i.e., species level) identification was possible, and the predation patterns of predators of different sizes were identifiable. The utilization of this method is strongly recommended for determining specific predator-prey relationships in complex freshwater ecosystems. PMID:24558577

  7. Canadian National Vegetation Classification (CNVC)

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The mandate of the CNVC is to comprehensively classify and describe natural and semi-natural Canadian vegetation in an ecologically meaningful manner. The...

  8. On two new species of the genus Cornudescoides Kulkarni, 1969 (Monogenea: Ancyrocephalinae) from a freshwater fish Mystus vittatus from Meerut (U.P.), India.

    Science.gov (United States)

    Rastogi, Pragati; Mishra, Deepmala; Singh, Jyoti; Rani, Kavita

    2012-04-01

    During study of freshwater monogeneans of Meerut region, we came across five infected specimen of fish Mystus vittatus, infected with monogeneans belonging to the genus Cornudescoides Kulkarni 1969. On subsequent study, the worms appear new to us and are described here in as such. C. kulkarnii n. sp. is characterized by four pairs of head organs, nut cracker shaped accessory piece of cirrus, capitulum or patches with proximal conical protruberance, longer inner root of dorsal anchor and difference in shape and extension of dorsal bars. While C. susanii n. sp. is characterized by presence of seven pairs of head organs, caliper like accessory piece of cirrus, longer and inwardly curved lateral hooks, prominently protruded outer roots and larger inner roots of dorsal anchor. PMID:23543628

  9. 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.

  10. 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.

  11. 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.

  12. 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)。

  13. Dietary exposure to perfluoroalkyl acids of specific French adult sub-populations: High seafood consumers, high freshwater fish consumers and pregnant women

    International Nuclear Information System (INIS)

    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−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. - 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

  14. Higher freshwater fish and sea fish intake is inversely associated with colorectal cancer risk among Chinese population: a case-control study

    OpenAIRE

    Ming Xu; Yu-Jing Fang; Yu-Ming Chen; Min-Shan Lu; Zhi-Zhong Pan; Bo Yan; Xiao Zhong; Cai-Xia Zhang

    2015-01-01

    The association between specific fish intake and colorectal cancer risk remains controversial. This study aimed to examine the association between specific fish intake and colorectal cancer risk in Chinese population in a large case control study. During July 2010 to November 2014, 1189 eligible colorectal cancer cases and 1189 frequency-matched controls (age and sex) completed in-person interviews. A validated food frequency questionnaire was used to estimate dietary intake. Multivariate log...

  15. 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).

  16. Fine-tuning for the tropics: application of eDNA technology for invasive fish detection in tropical freshwater ecosystems.

    Science.gov (United States)

    Robson, Heather L A; Noble, Tansyn H; Saunders, Richard J; Robson, Simon K A; Burrows, Damien W; Jerry, Dean R

    2016-07-01

    Invasive species pose a major threat to aquatic ecosystems. Their impact can be particularly severe in tropical regions, like those in northern Australia, where >20 invasive fish species are recorded. In temperate regions, environmental DNA (eDNA) technology is gaining momentum as a tool to detect aquatic pests, but the technology's effectiveness has not been fully explored in tropical systems with their unique climatic challenges (i.e. high turbidity, temperatures and ultraviolet light). In this study, we modified conventional eDNA protocols for use in tropical environments using the invasive fish, Mozambique tilapia (Oreochromis mossambicus) as a detection model. We evaluated the effects of high water temperatures and fish density on the detection of tilapia eDNA, using filters with larger pores to facilitate filtration. Large-pore filters (20 μm) were effective in filtering turbid waters and retaining sufficient eDNA, whilst achieving filtration times of 2-3 min per 2-L sample. High water temperatures, often experienced in the tropics (23, 29, 35 °C), did not affect eDNA degradation rates, although high temperatures (35 °C) did significantly increase fish eDNA shedding rates. We established a minimum detection limit for tilapia (1 fish/0.4 megalitres/after 4 days) and found that low water flow (3.17 L/s) into ponds with high fish density (>16 fish/0.4 megalitres) did not affect eDNA detection. These results demonstrate that eDNA technology can be effectively used in tropical ecosystems to detect invasive fish species.

  17. 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.

  18. 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.

  19. 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 frequently observed at the study sites and exhibited different spatial patterns of distribution in accordance with the maximum depth of the reservoirs. In the reservoirs with a maximum depth of more than 6 m, high densities of D. brachyurum were observed in the bottom layers; however, in the shallower reservoirs (maximum depth <6 m, D. brachyurum were concentrated in the surface layer. Moreover, during additional surveys, we observed a trend in which D. brachyurum densities increased as the maximum depth or macrophyte biomass increased. Gut contents analysis revealed that predatory fishes in each reservoir frequently consumed D. brachyurum; however, the consumption rate abruptly decreased in reservoirs where the maximum depth was more than 11 m or in the shallow reservoirs supporting a macrophyte bed. Interestingly, the reservoirs more than 11-m depth supported high densities of D. brachyurum in the bottom layer and in the surface macrophyte bed. Based on these results, reservoirs with a maximum depth of more than 11 m or those with a macrophyte bed may provide a refuge for D. brachyurum to avoid fish predation. Compared with other cladoceran species, D. brachyurum readily exploits various types of refugia (in this study, the deep layer or surface macrophyte bed, which may help explain why this species is abundant in various types of reservoirs.

  20. In vivo and in vitro exposures for the evaluation of the genotoxic effects of lead on the Neotropical freshwater fish Prochilodus lineatus

    International Nuclear Information System (INIS)

    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.

  1. Risk assessment for human consumption of perfluorinated compound-contaminated freshwater and marine fish from Hong Kong and Xiamen.

    Science.gov (United States)

    Zhao, Yin G; Wan, Hin T; Law, Alice Y S; Wei, Xi; Huang, Ye Q; Giesy, John P; Wong, Ming H; Wong, Chris K C

    2011-09-01

    Perfluorinated compounds (PFCs) are man-made fluoro-surfactants that are identified as global pollutants and can pose health risks to humans and wildlife. Two aspects of risk assessment were conducted in this study, including exposure and response. Exposure was estimated by using the concentrations of PFCs in fish and applying standard exposure factors. Among different PFCs, PFOS, PFOA, PFNA, PFDA, PFUdA and PFTrDA were detected. Total concentrations of PFC in fish ranged from 0.27-8.4 ng g(-1) to 0.37-8.7 ng g(-1) respectively in Hong Kong and Xiamen. The calculated hazard ratio (HR) of PFOS for all fish was less than 1.0. However, the HR for mandarin fish in Hong Kong and bighead carp, grass carp and tilapia in Xiamen, had HR values of approximately 0.5, indicating that frequent consumption of these 4 more contaminated fish species might pose an unacceptable risk to human health. Our data support the notion that the released/disposed chemical pollutants into water systems make fish a source of environmental toxicants to humans. The risks and potential effects of PFCs to health of coastal population in the Pearl River Delta are of concern. PMID:21705041

  2. Influence of dietary magnesium on mineral, ascorbic acid and glutathione concentrations in tissues of a freshwater fish, the common carp.

    Science.gov (United States)

    Dabrowska, H; Dabrowski, K

    1990-01-01

    Supplementation with dietary Mg at a minimum level of 0.06% seems to be essential to prevent the hypercalcinosis of the kidney and hepatopancreas in a fish, the common carp. Mg deficiency appears to have no effect on the Mg level in kidneys and hepatic tissue, whereas the Fe level in those tissues was significantly diminished by increasing dietary Mg supplementation up to 3.2 g.kg-1. Both hypercalcinosis and accumulation of Fe in soft tissues were more pronounced in fish offered diets high in protein (44%) compared to fish on low dietary protein (25%). The ascorbic acid in the hepatopancreas and kidney was greatly depleted in fish fed the high-protein diets, and this depletion did not correlate with the dietary Mg level nor with a high level of tissue Ca. However, the increased Ca concentration in the kidney coincided with the greatest depletion of ascorbate in fish fed a high-protein diet. The concentration of ascorbate in the brain was much less affected by a low level of vitamin C in the diets than in other tissues. Depletion of ascorbate in soft tissues did not correspond to fish growth but might be rather related to the metabolic rate imposed by the dietary nutrients. It is suggested that the Mg and ascorbic acid requirements in the carp are considerably elevated by the increased dietary protein level.

  3. Cascading life-history interactions: alternative density-dependent pathways drive recruitment dynamics in a freshwater fish.

    Science.gov (United States)

    Vandenbos, Rena E; Tonn, William M; Boss, Shelly M

    2006-07-01

    Although density-dependent mechanisms in early life-history are important regulators of recruitment in many taxa, consequences of such mechanisms on other life-history stages are poorly understood. To examine interacting and cascading effects of mechanisms acting on different life-history stages, we stocked experimental ponds with fathead minnow (Pimephales promelas) at two different densities. We quantified growth and survival of the stocked fish, the eggs they produced, and the resulting offspring during their first season of life. Per-capita production and survival of eggs were inversely related to density of stocked fish; significant egg cannibalism by stocked minnows resulted in initial young-of-the-year (YOY) densities that were inversely related to adult densities. Subsequent growth and survival of YOY were then inversely related to these initial YOY densities, and survival of YOY was selective for larger fish. Because of these compensatory processes in the egg and YOY stages, treatments did not differ in YOY abundance and mean size at the end of the growing season. Because of differences in the intensity of size-selective mortality, however, variation in end-of season sizes of YOY was strongly (and inversely) related to densities of stocked fish. When mortality was severe in the egg stage (high densities of stocked fish), final YOY size distributions were more variable than when the dominant mortality was size-selective in the YOY stage (low stocked fish densities). These differences in size variation could have subsequent recruitment consequences, as overwinter survival is typically selective for YOY fish larger than a critical threshold size. Density-dependent effects on a given life stage are not independent, but will be influenced by earlier stages; alternative recruitment pathways can result when processes at earlier stages differ in magnitude or selectivity. Appreciation of these cascading effects should enhance our overall understanding of the

  4. Overview of the artificial enhancement and release of endemic freshwater fish in China%中国淡水鱼类人工增殖放流现状

    Institute of Scientific and Technical Information of China (English)

    杨君兴; 潘晓赋; 陈小勇; 王晓爱; 赵亚鹏; 李建友; 李再云

    2013-01-01

    Due to declining fishery resources and the growing development of conservation aquaculture,artificial freshwater fish enhancement and releasing have begun to replace traditional means of recovering endemic and rare fish populations.Artificial proliferation can be beneficial both to endemic fish conservation and technical bottleneck breakthroughs.This overview presents a review of the latest research and the underlying principles behind the conservation implementation processes,as well as the research status of artificial enhancement and release of endangered freshwater fish species in China,such as Mylopharyngodon piceus,Ctenopharyngodon idellus,Hypophthalmichthys molitrix,H.nobilis,Acipenser sinensis,Myxocyprinus asiaticus,and Sinocyclocheilus grahami.The overview also presents evolutionarily significant units,sperm and egg quality,and cryopreservation technologies and cell cultures used in artificial enhancement and release,which help standardize genetic management and minimize the genetic differences between hatched and wild populations.Monitoring fish from cultivation to release is essential to evaluating wild population recovery and adjusting recovery plans.Moreover,the remaining problems of artificial releases are discussed in-depth,touching on issues such as the limitations of domestic hatching,the base number of wild populations necessary to the environment,the proper size at which to release juveniles' into the environment,the geographic confusion of populations,the contradictions in commercial fish selection and fish conservation,and "exotic species" invasion.%随着鱼类资源的持续衰退以及保护水产学的兴起,鱼类人工增殖放流已由传统渔业增殖发展成为特有珍稀鱼类种群恢复的主要技术手段.近年来,我国淡水鱼类人工增殖放流涉及水系多、规模大且种类丰富,取得了显著效果并积累了大量基础资料和经验.为深入开展人工增殖放流基础研究,规范技术并提升生态

  5. Distribution of Helminth Parasites in Intestines and Their Seasonal Rate of Infestation in Three Freshwater Fishes of Kashmir

    Directory of Open Access Journals (Sweden)

    Asifa Wali

    2016-01-01

    Full Text Available The present study was undertaken to determine the incidence of helminth parasites in fishes with special reference to water quality parameters in Dal Lake and River Jhelum and correlate the observations. Water, fish, and parasite samples were collected during different seasons from various sites and processed. Three fish species, namely, Schizothorax niger Heckel 1838, Schizothorax esocinus Heckel 1838, and Schizothorax curvifrons Heckel 1838, were recovered from these water bodies. The physicochemical parameters temperature, dissolved oxygen, pH, and free carbon dioxide showed variation vis-à-vis the season and location of the stations in water bodies. Acanthocephalan parasite Pomphorhynchus kashmirensis Kaw 1941 (27.47% and two intestinal cestodes Bothriocephalus acheilognathi Yamaguti 1934 (30.63% and Adenoscolex oreini Fotedar 1958 (32.43% were recovered from all the three species of Schizothorax. All the three parasites showed higher prevalence during summer and the least prevalence during winter. Parasitic infections were prevalent more in male fishes compared to females. The presence of the parasites had reduced the condition coefficient of the infected fishes in both water bodies. The study also showed that some of the physicochemical features showed a significant positive correlation with the prevalence.

  6. Evaluation of a method for determining concentrations of isoeugenol, an AQUI-S residue, in fillet tissue from freshwater fish species.

    Science.gov (United States)

    Meinertz, J.R.; Schreier, T.M.; Bernardy, J.A.

    2008-01-01

    AQUI-S is a fish anesthetic/sedative that is approved for use in a number of countries throughout the world and has the potential for use in the United States. The active ingredient in AQUI-S is isoeugenol. A method for determining isoeugenol concentrations in edible fillet tissue is needed for regulatory purposes, including surveillance and potential use in studies fulfilling human food safety data requirements if U.S. Food and Drug Administration approval is pursued. A method was developed and evaluated for determining isoeugenol concentrations in fillet tissue using relatively common procedures and equipment. The method produced accurate and precise results with fillet tissue from 10 freshwater fish species. The percentage of isoeugenol recovered from samples fortified with isoeugenol at nominal concentrations of 1, 50, and 100 microg/g for all species was always >80 and <97%. Within-day precision for samples fortified at those same concentrations was < or =10%, and day-to-day precision was < or =4.0%. Method precision with fillet tissue containing biologically incurred isoeugenol was < or =8.1%. There were no or minimal chromatographic interferences in control fillet tissue extracts from 9 of the 10 species. The method detection limits for all but one species ranged from 0.004 to 0.014 microg/g, and the quantitation limits ranged from 0.012 to 0.048 microg/g.

  7. Primary investigation on contamination pattern of legacy and emerging halogenated organic pollutions in freshwater fish from Liaohe River, Northeast China

    International Nuclear Information System (INIS)

    Legacy halogenated compounds, including polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), and emerging organo-halogen pollutants such as Dechlorane Plus (DP), were detected in fish from an old industrial region in Northeast China. PCBs and PBDEs were detected in all of the samples, with concentrations ranging from 38.15 to 170.51 ng/g lipid weight, and 9.40–39.69 ng/g lipid weight, respectively. DP was detected in more than 90% of the samples with concentrations ranging from not detected (ND) to 470 pg g/g lipid weight. Compared with similar data in other areas of the world, PCBs, PBDEs and DP in fish from Liaohe River were at medium or low level. An unusually high percentage of PCB-209 was first reported in the fish samples collected from China. Other halogenated pollutions, such as dichlorodiphenyltrichloroethane (DDT) and its metabolites, octachlorostyrene, chlorinated anisole, chlorinated thioanisole, triclosan-methyl, and other pesticides, have also been identified in the fish samples. - Highlights: ► DP was reported in fish samples from river close to an old industrial base in China. ► The first report on the unusually high fraction of PCB-209 in samples from China. ► GC × GC–TOFMS was used to identify non-targeted halogenated pollutants. - An unusually high percentage of PCB-209 was first reported in the fish samples collected from China, which might indicate that there were distinct sources of pure PCB-209 in the region of Liaohe River.

  8. Discussion on Technology of Producing Pet Food with Freshwater Fish Entrails%淡水鱼内脏研制宠物食品的工艺研究

    Institute of Scientific and Technical Information of China (English)

    叶丽秀; 熊光权; 周明; 杨德; 杜欣; 程薇

    2011-01-01

    [目的]探索淡水鱼内脏研制宠物食品的工艺.[方法]以淡水鱼内脏为原料,比较酶解法与离心法对提取鱼内脏中蛋白质的影响,通过膨化工艺参数选择试验考察挤压温度、螺杆转速、喂料速度等因素对产品质量的影响,确定宠物(猫狗)食品最佳工艺参数.[结果]用离心法处理鱼内脏,蛋白质回收率可达85.48%,但处理后滤渣较多.用酶解法处理鱼内脏,蛋白质和脂肪等营养成分回收率高,滤渣少,酶解最佳条件是:酶解温度50℃,复合酶添加量0.6%,木瓜与风味蛋白酶比例为1∶2,料液比为1∶1.5,水解时间为2.5h.宠物(猫狗)食品膨化工艺参数确定为:各区温度分别是Ⅰ区76℃、Ⅱ区135℃、Ⅲ区176℃,螺杆转速50 r/min,喂料速度17 r/min.[结论]淡水鱼内脏蛋白质的提取工艺,以酶解法优于直接离心法.%[Objective] The study aimed to explore the technology of producing the pet food with the freshwater fish entrails. [ Method ] With the freshwater fish viscera as the raw materials, the effects of the enzymatic and centrifugal methods for extracting the protein from the fish viscera were compared and the factors such as the extrusion temperature, screw speed, feed speed on the on the quality of product was investigated through the extrusion technology parameter selection test to confirm the optimum technology parameter for producing the pet food. [ Result ] The centrifugal method used to treat the fish entrails could get the protein recovery of 85.48% , but with more filter residues. The enzymatic method used to treat the fish entrails could get high recovery of the nutrient component such as the protein and lipid with less filter residues. The optimal enzymatic conditions were as follows; the digestion temperature was SO ℃ , the adding amount of the composite enzyme was 0.6%, the ratio of papaya and flavourzyme was 1 -2, the solid-liquid ratio was 1-1.5 and the hydrolysis time was 2.5 h. The

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

    DEFF Research Database (Denmark)

    Ito, Takafumi; Olesen, Niels Jørgen

    2013-01-01

    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...

  10. Effecy of parathion-methyl on Amazonian fish and freshwater invertebrates: A comparison of sensivity with temperate data

    NARCIS (Netherlands)

    Rico Artero, A.; Geber, R.; Campos Souto, P.; Garcia, M.V.B.; Brink, van den P.J.

    2010-01-01

    Parathion-methyl is an organophosphorous insecticide that is widely used in agricultural production sites in the Amazon. The use of this pesticide might pose a potential risk for the biodiversity and abundance of fish and invertebrate species inhabiting aquatic ecosystems adjacent to the agricultura

  11. An Efficiency Analysis of a Nature-Like Fishway for Freshwater Fish Ascending a Large Korean River

    Directory of Open Access Journals (Sweden)

    Jeong-Hui Kim

    2015-12-01

    Full Text Available Using traps and passive integrated transponder (PIT telemetry, we investigated the effectiveness of the nature-like fishway installed at Sangju Weir on the Nakdong River, Korea. In 11 regular checks over the study period, 1474 individuals classified into 19 species belonging to 5 families were collected by the traps, representing 66% of the species inhabiting the main channel of the Nakdong River. PIT tags were applied to 1615 individuals belonging to 22 species, revealing fishway attraction and passing rates of 20.7% and 14.5%, respectively. Interspecific differences were also shown. For 63.2% of fishes, it took more than a day to pass through the fishway. Some individuals spent a longer time (>28 days inside the fishway, suggesting the fishway was also being used for purposes other than passage. In this study, we verified species diversity of fish using a nature-like fishway installed in a large river in Korea. The results of this study provide a useful contribution to the development of fishways suitable for fish species endemic to Korea and for non-salmonid fish species worldwide.

  12. Environmental contaminants in freshwater fish and their risk to piscivorous wildlife based on a national monitoring program

    Science.gov (United States)

    Hinck, J.E.; Schmitt, C.J.; Chojnacki, K.A.; Tillitt, D.E.

    2009-01-01

    Organochlorine chemical residues and elemental concentrations were measured in piscivorous and benthivorous fish at 111 sites from large U.S. river basins. Potential contaminant sources such as urban and agricultural runoff, industrial discharges, mine drainage, and irrigation varied among the sampling sites. Our objectives were to provide summary statistics for chemical contaminants and to determine if contaminant concentrations in the fish were a risk to wildlife that forage at these sites. Concentrations of dieldrin, total DDT, total PCBs, toxaphene, TCDD-EQ, cadmium, chromium, mercury, lead, selenium, and zinc exceeded toxicity thresholds to protect fish and piscivorous wildlife in samples from at least one site; most exceedences were for total PCBs, mercury, and zinc. Chemical concentrations in fish from the Mississippi River Basin exceeded the greatest number of toxicity thresholds. Screening level wildlife risk analysis models were developed for bald eagle and mink using no adverse effect levels (NOAELs), which were derived from adult dietary exposure or tissue concentration studies and based primarily on reproductive endpoints. No effect hazard concentrations (NEHC) were calculated by comparing the NOAEL to the food ingestion rate (dietary-based NOAEL) or biomagnification factor (tissue-based NOAEL) of each receptor. Piscivorous wildlife may be at risk from a contaminant if the measured concentration in fish exceeds the NEHC. Concentrations of most organochlorine residues and elemental contaminants represented no to low risk to bald eagle and mink at most sites. The risk associated with pentachloroanisole, aldrin, Dacthal, methoxychlor, mirex, and toxaphene was unknown because NOAELs for these contaminants were not available for bald eagle or mink. Risk differed among modeled species and sites. Our screening level analysis indicates that the greatest risk to piscivorous wildlife was from total DDT, total PCBs, TCDD-EQ, mercury, and selenium. Bald eagles

  13. Plasticidade trófica em peixes de água doce Trophic plasticity in freshwater fishes

    Directory of Open Access Journals (Sweden)

    Angelo Antonio Agostinho

    2001-05-01

    Full Text Available Esta revisão apresenta uma síntese a respeito da plasticidade alimentar em teleósteos de água doce em relação às variações espaço-temporais, ontogenéticas, individuais e comportamentais. A ocorrência de dieta flexível é uma característica marcante da ictiofauna fluvial tropical, onde a maioria das espécies pode mudar de um alimento para outro tão logo ocorram oscilações na abundância relativa do recurso alimentar em uso, motivadas por alterações ambientais espaço-temporais. Quase todas as espécies mudam troficamente durante a ontogenia, e em muitas populações, os indivíduos podem apresentar preferências alimentares ou fazer uso de táticas alimentares distintas, conduzindo a um forrageamento intra-específico diferenciado. Essas considerações evidenciam dificuldades que podem ser encontradas no estabelecimento de padrões alimentares específicos fidedignos para as espécies de teleósteosA synthesis on the feeding flexibility in freshwater teleosts concerning seasonal, spatial, ontogenetic, individual and behavioral variation of freshwater teleosts is provided. The occurrence of a flexible diet is a striking aspect of tropical riverine ichthyofauna where most species may switch from a food item to another as soon as the relative abundance of the feeding resource in use oscillates, motivated by seasonal and spatial environmental alterations. There is a trophical change in almost all species during ontogeny, whereas in most populations, individuals may show feeding preferences or make use of distinct feeding tactics that lead towards a differentiated intraspecific foraging. These considerations highlight the difficulty on setting up reliable specific species feeding patterns in tropical teleosts

  14. 我国大宗淡水鱼可持续发展的战略构想%Strategy Conception for Sustainable Development of Massive Freshwater Fish in China

    Institute of Scientific and Technical Information of China (English)

    杨品红; 李梦军

    2011-01-01

    [目的]探索我国大宗淡水鱼可持续发展的战略构想.[方法]在分析我国大宗淡水鱼产业发展现状的基础上,提出了我国大宗淡水鱼可持续发展的战略构想.[结果]针对我国大宗淡水鱼产业面临的问题,提出了我国大宗淡水鱼可持续发展的基本战略:以渔业资源资本化带动资源的持续发展;以终端市场消费需求带动整个产业链的稳定发展:以引导市场消费需求提升产业市场地位;以加工和流通渠道建设带动种苗和养殖产业持续发展;以不同消费层次需求推动多层次多方式健康养殖;以品牌塑造和经营提升产业国际国内市场竞争地位.[结论]该研究对推动我国大宗淡水鱼产业的发展具有重大理论和现实意义.%[Objective] To propose strategy conception for sustainable development of massive freshwater fish in China. [ Method ] The current development status of massive freshwater fish industry in China was analyzed. On this basis, strategy conception for sustainable development of massive freshwater fish in China was proposed. [Result]In order to solve the present problems in the massive freshwater fish industry in China,basic strategies was proposed to develop the massive freshwater fish industry in China. Fishery resources should be capitalized to promote sustainable development of resources. Consumer demand of end-market should be used to drive stable development of the whole industry chain. Consumer demand should be guided to enhance the industrial market position. Processing and distribution channels should be constructed to promote sustainable development of seed and farming industries. Consumer demand at different levels should be used to promote multi-level multi-media healthy culture. Brand building and operating should be performed to enhance the competitive position of the industry in international and domestic markets. [ Conclusion ] The study has great theoretical and practical

  15. Monitoring mercury in freshwater fish in the oil sands region of Northern Alberta : spatial and temporal comparisons to regional mercury concentrations in fish

    International Nuclear Information System (INIS)

    The Regional Aquatics Monitoring Program (RAMP) was launched to provide a better understanding of the potential effects of oil sands development on aquatic systems, and to address issues important to communities of northern Alberta, such as mercury concentrations in fish. Muskeg dewatering, deforestation, flooding, and air emissions are among the potential mercury sources entering the aquatic systems within the oil sands region. RAMP collects non-lethal tissue samples on an annual basis for mercury analysis from northern pike (Esox lucius), walleye (Sander vitreus), and lake whitefish (Coregonus clupeaformis) in various rivers and lakes within the oil sands region. The purpose is to evaluate the suitability of fisheries resources for human consumption and to evaluate the potential cumulative biological effects on fish. A mercury database was developed based on studies in other regions in Alberta and across Canada in order to provide a regional context to the RAMP monitoring results. Data points from 1975 to 2009 were mapped to evaluate spatial and temporal differences in mercury concentrations and any exceedances of subsistence and general consumption guidelines. This monitoring effort has been instrumental in determining whether changes in mercury concentrations in fish are localized to a specific waterbody or regional in nature.

  16. 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...... for offspring growth in the wild is largely unknown. Otoliths of 366 age-0 pike (Esox lucius L.) were sampled in a natural lake over three seasons. All offspring were assigned to more than 330 potential mothers using 16 informative microsatellites. We found temperature and past maternal environment (as...... represented by juvenile growth rate), but not female total length, to jointly contribute to explain within- and among-season size variation in juvenile pike. While there was no statistical evidence for maternal effects on offspring growth rate, fast female juvenile growth positively correlated...

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

    Directory of Open Access Journals (Sweden)

    Marcela Videira

    2016-05-01

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

  18. A comparative analysis on the in vivo toxicity of copper nanoparticles in three species of freshwater fish.

    Science.gov (United States)

    Song, Lan; Vijver, Martina G; Peijnenburg, Willie J G M; Galloway, Tamara S; Tyler, Charles R

    2015-11-01

    Copper nanoparticles (CuNPs) are used extensively in a wide range of products and the potential for toxicological impacts in the aquatic environment is of high concern. In this study, the fate and the acute toxicity of spherical 50nm copper nanoparticles was assessed in juvenile rainbow trout (Oncorhynchus mykiss), fathead minnow (Pimephales promelas) and zebrafish (Danio rerio) for in vivo aqueous exposures following standardized OECD 203 guideline tests. The fate of the CuNPs in the aqueous media was temperature dependent. At the higher study temperature (26±1°C), there was both an enhanced particle aggregation and higher rate of dissolution compared with that at the lower study temperature (15±1°C). 96h LC50s of the CuNPs were 0.68±0.15, 0.28±0.04 and 0.22±0.08mg Cu/L for rainbow trout, fathead minnow and zebrafish, respectively. The 96h lowest-observed-effect concentration (LOEC) for the CuNPs were 0.17, 0.023 and <0.023mg/L for rainbow trout, fathead minnow, and zebrafish respectively, and are below the predicted environmental concentration of CuNPs for some aquatic environments suggesting a possible ecotoxicological risk to fish. Soluble copper was one of main drivers for the acute toxicity of the copper nanoparticles suspensions. Both CuNPs suspension and copper nitrate caused damage to gill filaments and gill pavement cells, with differences in sensitivity for these effects between the fish species studied. We show therefore common toxicological effects of CuNPs in different fish species but with differences in sensitivity with implications for hazard extrapolation between fish species.

  19. Effect of copper on liver key enzymes of anaerobic glucose metabolism from freshwater tropical fish Prochilodus lineatus.

    Science.gov (United States)

    Carvalho, Cleoni dos Santos; Fernandes, Marisa Narciso

    2008-11-01

    We investigated the effect of copper on liver key enzymes of the anaerobic glucose metabolism (hexokinase, HK; phosphofructokinase, PFK; pyruvate kinase, PK; lactate dehydrogenase, LDH) as well as of the pentose pathway (glycose-6-phosphate dehydrogenase, G6PDH) from the fish Prochilodus lineatus. The fish were acclimated at either 20 degrees C or 30 degrees C at pH 7.0, transferred to water at pH 4.5 or 8.0, and exposed to 96 h-CL(50) copper concentrations. Copper accumulation in liver was higher in fish acclimated at 20 degrees C and maintained in water pH 8.0. Three-way analysis of variance revealed a significant effect of temperature on all enzymes, a significant effect of pH on all enzymes except for PK, and a significant effect of copper on only PFK, and LDH in pH 4.5 at 20 degrees C and, at 30 degrees C, on PFK and PK at pH 4.5 and 8.0, HK at pH 4.5 and G6PDH at pH 8.0. There were significant interactions between treatments for many enzymes. These changes suggest that the activity of enzymes in question is modified by a change in ambient water. At least at 30 degrees C, the overall reduction in the glycolytic enzyme activities of copper-exposed fish seems to reduce energy availability via glucose metabolism, thereby contributing to enhance copper toxic effects.

  20. Assessment of Morphometric and Genetic Variation in Three Freshwater Fish Species of the Genus Garra (Osteichthyes: Cyprinidae)

    OpenAIRE

    Arulraj DHINAKARAN; Nabeel Mannalamkunnath ALIKUNHI; Selvaraj CHINNATHAMBI; Ramaiya SORNAM; Kalaiselvam, Murugaiyan; Ramodoss RAJASEKARAN; Subramanian MANIVANNAN

    2011-01-01

    The present study evaluated the patterns of morphometric and genetic variation using RAPD-PCR techniques for the first time on three species of Garra, viz. G. mullya, G. kalakadensis and G. gotyla stenorhynchus, collected from various river basins of South-India. The results of morphological analysis revealed that G. mullya and G. kalakadensis hold many similar characters compared to the other congener, G. gotyla stenorhynchus. However, the G. gotyla stenorhynchus fish species exhibited disti...

  1. Gustatory Detection of Tetrodotoxin and Saxitoxin, and Its Competitive Inhibition by Quinine and Strychnine in Freshwater Fishes

    Directory of Open Access Journals (Sweden)

    Toshiaki J. Hara

    2011-11-01

    Full Text Available Fish detect extremely low levels of marine toxins tetrodotoxin (TTX and saxitoxin (STX via the specialized gustatory receptor(s. Physiological and pharmacological studies show that receptor(s for TTX and STX are distinct from those which detect feeding stimulant amino acids and bile acids, and that TTX and STX do not share the same receptor populations, while interacting with quinine and strychnine in a competitive fashion suggestive of an antidotal relationship.

  2. Research on Interrelationship between some Species of Freshwater Fish and Helmintic Larvae within Aquatic Ecosystems Polluted with Heavy Metals

    OpenAIRE

    Laura Daniela Urdeş; Cristiana Diaconescu; Geanina Vlase; Daniela Ianiţchi; Ştefan Diaconescu; Marius Hangan

    2010-01-01

    The objective of this study was to investigate the ability of some larvae of cestodes and nematodes which live infreshwater fish (intermediate hosts), to exhibit an uptake of heavy metals.According to some scientifical papers treating this subject, only adult worms were able to absorb successfully heavymetals within their hosts. Furthermore, it is believed that only the adults would act as biofilters and consequently astrustworthy indicators of environmental pollution.This study, carried out ...

  3. A comparative analysis on the in vivo toxicity of copper nanoparticles in three species of freshwater fish.

    Science.gov (United States)

    Song, Lan; Vijver, Martina G; Peijnenburg, Willie J G M; Galloway, Tamara S; Tyler, Charles R

    2015-11-01

    Copper nanoparticles (CuNPs) are used extensively in a wide range of products and the potential for toxicological impacts in the aquatic environment is of high concern. In this study, the fate and the acute toxicity of spherical 50nm copper nanoparticles was assessed in juvenile rainbow trout (Oncorhynchus mykiss), fathead minnow (Pimephales promelas) and zebrafish (Danio rerio) for in vivo aqueous exposures following standardized OECD 203 guideline tests. The fate of the CuNPs in the aqueous media was temperature dependent. At the higher study temperature (26±1°C), there was both an enhanced particle aggregation and higher rate of dissolution compared with that at the lower study temperature (15±1°C). 96h LC50s of the CuNPs were 0.68±0.15, 0.28±0.04 and 0.22±0.08mg Cu/L for rainbow trout, fathead minnow and zebrafish, respectively. The 96h lowest-observed-effect concentration (LOEC) for the CuNPs were 0.17, 0.023 and environments suggesting a possible ecotoxicological risk to fish. Soluble copper was one of main drivers for the acute toxicity of the copper nanoparticles suspensions. Both CuNPs suspension and copper nitrate caused damage to gill filaments and gill pavement cells, with differences in sensitivity for these effects between the fish species studied. We show therefore common toxicological effects of CuNPs in different fish species but with differences in sensitivity with implications for hazard extrapolation between fish species. PMID:26121603

  4. Parasites as biological tags of marine, freshwater and anadromous fishes in North America from the Tropics to the Arctic.

    Science.gov (United States)

    Marcogliese, David J; Jacobson, Kym C

    2015-01-01

    Parasites have been considered as natural biological tags of marine fish populations in North America for almost 75 years. In the Northwest Atlantic, the most studied species include Atlantic cod (Gadus morhua), Atlantic herring (Clupea harengus) and the redfishes (Sebastes spp.). In the North Pacific, research has centred primarily on salmonids (Oncorhynchus spp.). However, parasites have been applied as tags for numerous other pelagic and demersal species on both the Atlantic and Pacific coasts. Relatively few studies have been undertaken in the Arctic, and these were designed to discriminate anadromous and resident salmonids (Salvelinus spp.). Although rarely applied in fresh waters, parasites have been used to delineate certain fish stocks within the Great Lakes-St Lawrence River basin. Anisakid nematodes and the copepod Sphyrion lumpi frequently prove useful indicators in the Northwest Atlantic, while myxozoan parasites prove very effective on the coast and open seas of the Pacific Ocean. Relative differences in the ability of parasites to discriminate between fish stocks on the Pacific and Atlantic coasts may be due to oceanographic and bathymetric differences between regions. Molecular techniques used to differentiate populations and species of parasites show promise in future applications in the field.

  5. Subcellular differences in handling Cu excess in three freshwater fish species contributes greatly to their differences in sensitivity to Cu

    Energy Technology Data Exchange (ETDEWEB)

    Eyckmans, Marleen, E-mail: marleen.eyckmans@ua.ac.be [Laboratory for Ecophysiology, Biochemistry and Toxicology, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp (Belgium); Blust, Ronny; De Boeck, Gudrun [Laboratory for Ecophysiology, Biochemistry and Toxicology, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp (Belgium)

    2012-08-15

    Since changes in metal distribution among tissues and subcellular fractions can provide insights in metal toxicity and tolerance, we investigated this partitioning of Cu in gill and liver tissue of rainbow trout (Oncorhynchus mykiss), common carp (Cyprinus carpio) and gibel carp (Carassius auratus gibelio). These fish species are known to differ in their sensitivity to Cu exposure with gibel carp being the most tolerant and rainbow trout the most sensitive. After an exposure to 50 {mu}g/l (0.79 {mu}M) Cu for 24 h, 3 days, 1 week and 1 month, gills and liver of control and exposed fish were submitted to a differential centrifugation procedure. Interestingly, there was a difference in accumulated Cu in the three fish species, even in control fishes. Where the liver of rainbow trout showed extremely high Cu concentrations under control conditions, the amount of Cu accumulated in their gills was much less than in common and gibel carp. At the subcellular level, the gills of rainbow trout appeared to distribute the additional Cu exclusively in the biologically active metal pool (BAM; contains heat-denaturable fraction and organelle fraction). A similar response could be seen in gill tissue of common carp, although the percentage of Cu in the BAM of common carp was lower compared to rainbow trout. Gill tissue of gibel carp accumulated more Cu in the biologically inactive metal pool (BIM compared to BAM; contains heat-stable fraction and metal-rich granule fraction). The liver of rainbow trout seemed much more adequate in handling the excess Cu (compared to its gills), since the storage of Cu in the BIM increased. Furthermore, the high % of Cu in the metal-rich granule fraction and heat-stable fraction in the liver of common carp and especially gibel carp together with the better Cu handling in gill tissue, pointed out the ability of the carp species to minimize the disadvantages related to Cu stress. The differences in Cu distribution at the subcellular level of gills

  6. Subcellular differences in handling Cu excess in three freshwater fish species contributes greatly to their differences in sensitivity to Cu

    International Nuclear Information System (INIS)

    Since changes in metal distribution among tissues and subcellular fractions can provide insights in metal toxicity and tolerance, we investigated this partitioning of Cu in gill and liver tissue of rainbow trout (Oncorhynchus mykiss), common carp (Cyprinus carpio) and gibel carp (Carassius auratus gibelio). These fish species are known to differ in their sensitivity to Cu exposure with gibel carp being the most tolerant and rainbow trout the most sensitive. After an exposure to 50 μg/l (0.79 μM) Cu for 24 h, 3 days, 1 week and 1 month, gills and liver of control and exposed fish were submitted to a differential centrifugation procedure. Interestingly, there was a difference in accumulated Cu in the three fish species, even in control fishes. Where the liver of rainbow trout showed extremely high Cu concentrations under control conditions, the amount of Cu accumulated in their gills was much less than in common and gibel carp. At the subcellular level, the gills of rainbow trout appeared to distribute the additional Cu exclusively in the biologically active metal pool (BAM; contains heat-denaturable fraction and organelle fraction). A similar response could be seen in gill tissue of common carp, although the percentage of Cu in the BAM of common carp was lower compared to rainbow trout. Gill tissue of gibel carp accumulated more Cu in the biologically inactive metal pool (BIM compared to BAM; contains heat-stable fraction and metal-rich granule fraction). The liver of rainbow trout seemed much more adequate in handling the excess Cu (compared to its gills), since the storage of Cu in the BIM increased. Furthermore, the high % of Cu in the metal-rich granule fraction and heat-stable fraction in the liver of common carp and especially gibel carp together with the better Cu handling in gill tissue, pointed out the ability of the carp species to minimize the disadvantages related to Cu stress. The differences in Cu distribution at the subcellular level of gills and

  7. Maryland ESI: FISH (Fish Polygons)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for marine, estuarine, anadromous, and freshwater fish species in Maryland. Vector polygons in this data...

  8. Louisiana ESI: FISH (Fish Polygons)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for freshwater (inland) fish species in coastal Louisiana. Vector polygons represent water-bodies and...

  9. Alabama ESI: FISH (Fish Polygons)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for marine, estuarine, and freshwater fish species in Alabama. Vector polygons in this data set represent...

  10. Anodontites trapesialis (LAMARCK, 1819: a bivalve parasite of freshwater fishes / Anodontites trapesialis (LAMARCK, 1819: um bivalve parasito de peixes de água doce

    Directory of Open Access Journals (Sweden)

    Ângela Teresa Silva-Souza

    2008-08-01

    Full Text Available The bivalve mollusk Anodontites trapesialis has been indicated as an alternative source for aquaculture because it is considered a food of good nutritional value with a protein content close to that of fish. Its shells can be utilized as fertilizer and mixed to the food of domestic animals, and the nacre can be used to manufacture buttons and crafts. However, the larvae of A. trapesialis, which are the lasidium type, are obligatory parasites of freshwater fishes, and the introduction of this bivalve in fish farm tanks have caused trouble and losses for producers. Nothing is known, however, about their development in these environments. On the other hand, it should be pointed out that A. trapesialis is on Brazil’s list of species threatened with extinction. This article provides a compilation of information present in the literature, offering a detailed review, with the aim of presenting a general panorama of what is known about Anodontites trapesialis and its larval parasitism of fishes.O molusco bivalve, Anodontites trapesialis, tem sido indicado como fonte alternativa para a aqüicultura, por ser considerado um alimento de bom valor nutricional com um conteúdo protéico próximo ao do pescado. Suas conchas podem ser utilizadas como fertilizantes calcáreos e ser agregadas a alimentos de animais domésticos e o nácar pode ser utilizado para fabricar botões e artesanatos. No entanto, as larvas de A. trapesialis, que são do tipo lasidium, são parasitas obrigatórias de peixes de água doce e a introdução desse bivalve em tanques de piscicultura tem causado transtornos e prejuízos aos produtores. Nada se conhece, porém, sobre o seu desenvolvimento nesses ambientes. Por outro lado, ressalta-se que A. trapesialis consta da lista brasileira de espécies ameaçadas de extinção. No presente artigo são compiladas as informações presentes na literatura, em uma revisão detalhada, com o objetivo de apresentar o panorama geral do

  11. Braga cigarra comb. nov. for Philostomella cigarra (Crustacea: Isopoda: Cymothoidae with a redescription of the species based on specimens from Galeocharax kneri, a freshwater fish of Minas Gerais State, Brazil

    Directory of Open Access Journals (Sweden)

    Vernon E. Thatcher

    2009-03-01

    Full Text Available Specimens of a cymothoid isopod from a freshwater fish of Minas Gerais State were studied. These were found to be morphologically comparable to Philostomella cigarra Szidat & Schubart, 1960, except for having multilaminate pleopods which is the distinguishing characteristic of the genus Braga Schiödte & Meinert, 1881. The first pleopod is bilaminate while the second is quadrilaminate. Pleopods three to five are trilaminate. It is herein proposed that the generic name Philostomella Szidat & Schubart, 1960, should be considered invalid and that the species P. cigarra should be transferred to Braga. Braga now contains eight species, including B. cigarra comb. nov., all from South American freshwater fishes. The principal difference between this species and the others in the genus is the form of the female which has a narrow pleon and a small pleotelson. A redescription of this species is presented here because previous descriptions in the literature are inaccurate or incomplete.

  12. Record of Urocleidoides vaginoclaustrum Jogunoori, Kritsky and Venkatanarasaiah, 2004 (Monogenea: Dactylogyridae) from a freshwater fish in Mexico.

    Science.gov (United States)

    Mendoza-Palmero, C A; Aguilar-Aguilar, R

    2008-10-01

    We describe herein the first occurrence of the monogenean Urocleidoides vaginoclaustrum in the wild. This monogenean was originally described from an aquarium neotropical fish examined in India. Worms were collected from the gills of Xiphophorus hellerii, a species native to tropical Mexico but introduced to the Los Berros Spring in the State of Durango, Northern Mexico. These specimens showed slight morphological differences in the sclerotized structures of the haptor with respect to the specimens described from India. A brief morphological characterization of this species is presented.

  13. Record of Urocleidoides vaginoclaustrum Jogunoori, Kritsky and Venkatanarasaiah, 2004 (Monogenea: Dactylogyridae) from a freshwater fish in Mexico.

    Science.gov (United States)

    Mendoza-Palmero, C A; Aguilar-Aguilar, R

    2008-10-01

    We describe herein the first occurrence of the monogenean Urocleidoides vaginoclaustrum in the wild. This monogenean was originally described from an aquarium neotropical fish examined in India. Worms were collected from the gills of Xiphophorus hellerii, a species native to tropical Mexico but introduced to the Los Berros Spring in the State of Durango, Northern Mexico. These specimens showed slight morphological differences in the sclerotized structures of the haptor with respect to the specimens described from India. A brief morphological characterization of this species is presented. PMID:18661283

  14. 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).

  15. Research on Interrelationship between some Species of Freshwater Fish and Helmintic Larvae within Aquatic Ecosystems Polluted with Heavy Metals

    Directory of Open Access Journals (Sweden)

    Laura Daniela Urdeş

    2010-10-01

    Full Text Available The objective of this study was to investigate the ability of some larvae of cestodes and nematodes which live infreshwater fish (intermediate hosts, to exhibit an uptake of heavy metals.According to some scientifical papers treating this subject, only adult worms were able to absorb successfully heavymetals within their hosts. Furthermore, it is believed that only the adults would act as biofilters and consequently astrustworthy indicators of environmental pollution.This study, carried out on the Danube Delta area, comes to prove the ability of the larvae to absorb heavy metalswithin their hosts, even when the pollution level with respect to heavy metals is very low.Following the biochemical analyses of water, sediment, aquatic plants, larvae and fish tissues (liver and musclesamples, it resulted that the larvae were able to absorb important quantities within their hosts, so that only scarceamounts to be found in the muscle and liver. Both parasites were able to accumulate some heavy metals within theirhosts, although only one of them did it successfully.

  16. Microscopic morphology and histochemistry of the digestive system of a tropical freshwater fish Trichomycterus brasiliensis (Lütken (Siluroidei, Trichomycteridae

    Directory of Open Access Journals (Sweden)

    Ciro Alberto de Oliveira Ribeiro

    2000-12-01

    Full Text Available The digestive system of Trichomycterus brasiliensis (Lütken, 1874, a small sized tropical Teleostean fish widely distributed in South America, was studied. Tissue samples were prepared for light and scanning electron microscopy (SEM. Trichomycterus brasiliensis shows stratified esophagus epithelium with taste buds and goblet cells with neutral and acid mucus at the anterior region. The stomach is caecal, presenting a pyloric valve with neutral mucus cells. At the terminal portion it is surrounded by a thick muscular wall. The intestine shows two loops; the epithelium is single columnar, with acid and neutral mucus in goblet cells. Multicellular intestinal glands are absent. Granular cells are often seen in the mucosa, less in the submucosa but were not observed in the muscularis. After the intestine-rectal valve, the rectum shows lower mucosal folds, more goblet cells and a thicker muscularis. No lobes were observed at the liver. Small regions of pancreatic tissue may be identified within the hepatic tissue mainly surrounding vessels and ducts. A compact pancreas may also be observed ventrally to the stomach and covering the bile duct. The possible significance of the heterogeneous character of the digestive tube mucosubstances is discussed. The digestive system of T. brasiliensis presents structural characteristics of a predator fish.

  17. Potaspora aequidens n. sp. (Microsporidia, Tetramicridae), a parasite infecting the freshwater fish Aequidens plagiozonatus (Teleostei, Cichlidae) from Brazil.

    Science.gov (United States)

    Videira, Marcela; Casal, Graça; Rocha, Sónia; Gonçalves, Evonnildo; Azevedo, Carlos; Velasco, Michele; Matos, Edilson Rodrigues

    2015-07-01

    Morphological and molecular procedures were used to describe a new species of microsporidian that infects the muscles of the sub-opercular region and the caudal fins of the freshwater Aequidens plagiozonatus in Brazil. This microsporidian forms whitish xenomas containing variable number of spores, reaching up to ~0.4 mm in diameter. The mature spores, pyriformin shape, with slightly round ends, measured 3.4 ± 0.5 μm long and 1.9 ± 0.3 μm wide (n = 50) and showed characteristics typical of Microsporidia. The average thickness of the spore wall was 100 (96-108) nm (n = 50), and the spore wall was composed of two layers, a thin, electron-dense exospore and a thick electron-transparent endospore. The exospore was surrounded by a thin, irregular layer of granular material. The anchoring disc was mushroom-like, located in the apical region of the spore in an eccentric position relative to the spore axis, rendering bilateral asymmetry to the spore. The anterior part of the polar filament (PF) (manubrium) measured approximately 125 (122-128) nm thick (n = 30), and the angle of tilt between the anterior PF and the spore axis was ~45°; the posterior part was packed in 8-9 coils. Phylogenetic analysis showed a strongly supported clade containing family Spragueidae Weissenberg, 1976, family Tetramicridae Matthews and Matthews, 1980, Microsporidium sp. RBS1, and Kabatana spp. In conclusion, the available morphological, ultrastructural, and molecular data shows that this microsporidian is a new species belonging to group 4, classified as Potaspora aequidens n. sp. This is the second species described in the genus Potaspora. PMID:25813455

  18. Riggia cryptocularis sp. nov. (Isopoda, Cymothoidae from the body cavity of a freshwater fish of Mato Grosso do Sul State, Brazil

    Directory of Open Access Journals (Sweden)

    Thatcher Vernon E.

    2003-01-01

    Full Text Available Riggia cryptocularis sp. nov. (Isopoda, Cymothoidae is described on the basis of one female and one male specimen from the body cavity of freshwater fish from Mato Grosso do Sul State, Brazil. The new species is similar in size to R. paranensis Szidat, 1948, but differs from that species in the following respects. The body shapes are different since the widest part of the adult female is more anterior in R. paranensis. The eyes of the new species are covered and non-functional unlike those of the other species. The cephalon of the new species has a postero-dorsal elevation and a rounded and depressed frons which are lacking in the other species. Pereonites 5-7 are subequal in length in the new species and decrease in length in R. paranensis. The pleon/pleotelson tapers in the female of the new species and in the other it is bluntly rounded and with nearly parallel sides. The pleopods of R. cryptocularis sp. nov. also taper while those of R. paranensis are rounded. The recently described species, R. acuticaudata Thatcher, Lopes & Froehlich, 2002, was also obtained in Mato Grosso do Sul State but differs greatly from the presently described species. The body of R. acuticaudata is much smaller, and more rounded. The eyes of this species are large and functional, the dorsum of the cephalon lacks a dorsal prominence and the pleon/pleotelson tapers more abruptly.

  19. Salinity and temperature variations reflecting on cellular PCNA, IGF-I and II expressions, body growth and muscle cellularity of a freshwater fish larvae.

    Science.gov (United States)

    Martins, Y S; Melo, R M C; Campos-Junior, P H A; Santos, J C E; Luz, R K; Rizzo, E; Bazzoli, N

    2014-06-01

    The present study assessed the influence of salinity and temperature on body growth and on muscle cellularity of Lophiosilurus alexaxdri vitelinic larvae. Slightly salted environments negatively influenced body growth of freshwater fish larvae and we observed that those conditions notably act as an environmental influencer on muscle growth and on local expression of hypertrophia and hypeplasia markers (IGFs and PCNA). Furthermore, we could see that salinity tolerance for NaCl 4gl(-)(1) diminishes with increasing temperature, evidenced by variation in body and muscle growth, and by irregular morphology of the lateral skeletal muscle of larvae. We saw that an increase of both PCNA and autocrine IGF-II are correlated to an increase in fibre numbers and fibre diameter as the temperature increases and salinity diminishes. On the other hand, autocrine IGF-I follows the opposite way to the other biological parameters assessed, increasing as salinity increases and temperature diminishes, showing that this protein did not participate in muscle cellularity, but participating in molecular/cellular repair. Therefore, slightly salted environments may provide adverse conditions that cause some obstacles to somatic growth of this species, suggesting some osmotic expenditure with a salinity increment.

  20. Occurrence and availability of prioritary compounds (chlorinated pesticides, polybrominated diphenyl ethers, alkylphenols and heavy metals) in freshwater sediments and fish

    International Nuclear Information System (INIS)

    Full text: The aim of this work was to determine priority organic and inorganic compounds in river sediments and fish and to study their availability. Twelve organ chlorinated compounds (OC), 40 polybromodiphenyl ethers (PBDEs), 2 alkylphenols (nonylphenol and octylphenol) (AP), and 9 heavy metals (HM) were investigated in samples taken in 20 locations along the Ebro river, in north east Spain. Sediment samples represent a stable matrix which indicate recent pollution episodes, whereas fish samples are good sentinels to monitor bioavailability and bioaccumulation. Compound selection was based on their inclusion in European priority lists (Directives 76/464/CEE and 60/2000/EU). The study area covered the Ebro hydrographic basin which is the main tributary in Spain and flows through large agricultural areas characterized by wines, corn and maize and represents an important water source for the many industrial and urban activities settled along its course. To control the quality of the river basin, and in accordance with EU Directives, priority pollutants have been determined in sediment and fish to determine most ubiquitous compounds, geographical distribution and bioavailability of pollutants to two different fish species. For such purpose, different analytical methods were developed to analyse all the above mentioned chemical species in the upper 2 cm sediment layer and in whole fish (Barbus graellsii, Cyprinus carpio). Among compounds studied, hexachlorocyclohexane, pentachlorophenol, aldrin, dieldrin and isodrin, and trichlorobenzene were never detected. All samples contained organic pollutants at total levels between 134 and 3199 μg/Kg-dw and total HM from 60.9 and 5131 mg/kg-dw, depending on sample location. For 18 of the 20 samples points, a correlation of 0.53 was found between total organic and total inorganic concentration. In sediment samples, among the 4 chemical groups studied, HM were present at levels between 0.17 and 4036 mg/kg dry weight (dw), being

  1. Occurrence and availability of prioritary compounds (chlorinated pesticides, polybrominated diphenyl ethers, alkylphenols and heavy metals) in freshwater sediments and fish

    International Nuclear Information System (INIS)

    Full text: The aim of this work was to determine priority organic and inorganic compounds in river sediments and fish and to study their availability. Twelve organ chlorinated compounds (OC), 40 polybromodiphenyl ethers (PBDEs), 2 alkylphenols (nonylphenol and octylphenol) (AP), and 9 heavy metals (HM) were investigated in samples taken in 20 locations along the Ebro river, in north east Spain. Sediment samples represent a stable matrix which indicate recent pollution episodes, whereas fish samples are good sentinels to monitor bioavailability and bioaccumulation. Compound selection was based on their inclusion in European priority lists (Directives 76/464/CEE and 60/2000/EU). The study area covered the Ebro hydrographic basin which is the main tributary in Spain and flows through large agricultural areas characterized by wines, corn and maize and represents an important water source for the many industrial and urban activities settled along its course. To control the quality of the river basin, and in accordance with EU Directives, priority pollutants have been determined in sediment and fish to determine most ubiquitous compounds, geographical distribution and bioavailability of pollutants to two different fish species. For such purpose, different analytical methods were developed to analyse all the above mentioned chemical species in the upper 2 cm sediment layer and in whole fish (Barbus graellsii, Cyprinus carpio). Among compounds studied, hexachlorocyclohexane, pentachlorophenol, aldrin, dieldrin and isodrin, and trichlorobenzene were never detected. All samples contained organic pollutants at total levels between 134 and 3199 μg/Kg-dw and total HM from 60.9 and 5131 mg/kg-dw, depending on sample location. For 18 of the 20 samples points, a correlation of 0.53 was found between total organic and total inorganic concentration. In sediment samples, among the 4 chemical groups studied, HM were present at levels between 0.17 and 4036 mg/kg dry weight (dw), being

  2. Discovering the African freshwater "torpedo": legendary Ethiopia, religious controversies, and a catfish capable of reanimating dead fish.

    Science.gov (United States)

    Piccolino, Marco; Finger, Stanley; Barbara, Jean-Gaël

    2011-07-01

    The electric catfishes of African rivers and lakes, once depicted on Egyptian tomb art, have been largely overlooked in histories and reviews of electric fish biology and animal electricity. This article examines how Westerners, especially Dominican and Jesuit missionaries, discovered them in Ethiopia and other parts of Africa at the beginning of the seventeenth century. What transpired took place against the backdrop of tales involving the Bible, Prester John's mythical empire, and imaginary animals with fabulous powers. In effect, how they were found is related to attempts to convert Ethiopian Christians to true Catholicism, hopes of discovering great riches, and opportunities to trade, and not with the efforts of skilled natural philosophers to document and conduct experiments on the wildlife of this continent. Nevertheless, the early descriptions by Europeans circulated, and during the next century these catfishes began to be used in experiments that helped to make animal electricity a reality. PMID:21736441

  3. Comparison of Material Characteristics among Conventional Freshwater Fish Species%大宗淡水鱼类原料特性比较分析

    Institute of Scientific and Technical Information of China (English)

    杨京梅; 夏文水

    2012-01-01

    The material characteristics of such conventional freshwater fish species as snail carp, grass carp, silver carp, bighead carp, carp, crucian carp and bream were studied. The weight percentage of each part, meat-producing rate, basic components, pH, protein composition and texture profile analysis (TPA) of back muscle were investigated. The results indicated that the weight percentages of viscera and head in seven species of freshwater fish were significantly different. The meat-producing rate of black carp was the highest, 54.33%, while bighead carp was the lowest, 32.80%. Little difference in basic components was observed except for higher crude fat content in bream (4.08%) compared with other fish species. The highest percentages of non- protein nitrogen, water-soluble protein, salt-soluble protein, alkali-soluble protein and alkali-insoluble protein were found in silver carp (1.67%), carp (4.68%), grass carp (9.91%), carp (2.45%) and bream (0.83%), respectively. Based on the TPA parameters, better textural characteristics were observed in black carp and crap.%对7种大宗淡水鱼的原料特性进行比较分析,测定7种大宗淡水鱼鱼体各部分比例、采肉率、基本成分、pH值及蛋白质组成,并对鱼背肉进行质地多面剖析(TPA)测试。结果表明:7种大宗淡水鱼之间内脏和鱼头所占比例差异较明显;青鱼的采肉率最高为54.33%,鳙鱼的最低为32.80%;水分、灰分和粗蛋白含量差异较小;粗脂肪含量鳊鱼最高为4.08%;非蛋白氮、水溶性蛋白、盐溶性蛋白、碱溶性蛋白和碱不溶性蛋白在7种鱼肉中所占比例最高的分别为鲢鱼(1.67%)、鲤鱼(4.68%)、草鱼(9.91%)、鲤鱼(2.45%)和鳊鱼(0.83%);综合考虑TPA测试的相关参数,青鱼和鲤鱼肉的质构特性较好。

  4. Exposure to an agricultural contaminant, 17β-trenbolone, impairs female mate choice in a freshwater fish.

    Science.gov (United States)

    Tomkins, Patrick; Saaristo, Minna; Allinson, Mayumi; Wong, Bob B M

    2016-01-01

    Despite the pivotal role sexual selection plays in population dynamics and broader evolutionary processes, the impact of chemical pollution on female mate choice is poorly understood. One group of chemical contaminants with the potential to disrupt the mechanisms of female mate choice is endocrine disrupting chemicals (EDCs); a broad class of environmental pollutants that can interfere with the endocrinology of organisms at extremely low concentrations. Recent research has revealed that estrogenic EDCs can affect female mate choice in fish, but the impact of androgenic EDC exposure is yet to be studied. To address this, we investigated the effects of an environmentally relevant concentration of trenbolone - an androgenic steroid used as a growth promoter in the cattle industry - on female mate choice in wild-caught guppies (Poecilia reticulata). We exposed male and female guppies to 17β-trenbolone for 21 days (measured concentration 4ng/L) via a flow-through system, and found that trenbolone-exposed female guppies spent less time associating with males, and were less choosy, compared to unexposed females. In contrast, trenbolone had no impact on male reproductive behavior or morphology. This is the first study to show that androgenic EDC exposure can disrupt female mate choice, highlighting the need for studies to investigate the behavioral impacts of environmental contaminants on both sexes.

  5. Laboratory Bioaccumulation, Depuration And Total Dose Rate Of Waterborne Th-232 In Freshwater Fish Of Anabas Testudineus

    International Nuclear Information System (INIS)

    Preliminary results on the study of bioaccumulation, depuration and total dose rate of Th-232 in the whole body of Anabas testudineus are presented. The objective of this study was to evaluate the effect of Th-232 concentration activity on the laboratory bioaccumulation, depuration and total dose rate in Anabas testudineus. Anabas testudineus adults were exposed to different waterborne Th-232 levels: 0 BqL-1 (control), 50 BqL-1 and 100 BqL-1 for 30 day (uptake phase), followed by exposure to radionuclide-free water for 30 days (loss phase). Radionuclide concentration ratios between the whole body levels and water levels, percentage of Th-232 remaining in fish were calculated and total dose rates using ERICA Assessment Tool were also estimated. The results showed the increase of waterborne Th-232 concentration corresponded to a progressive increase of Th accumulation and total dose rate (internal and external) in the whole body of Anabas testudineus. Considering the ERICA dose rate screening value of 10 μGyh-1, the findings can be concluded the estimated of total dose rate (< 5 μGyh-1) in Anabas testudineus is in order of small magnitude. Nevertheless, these preliminary results showed that the Anabas testudineus has a potential to accumulate thorium. (author)

  6. Assessment of Morphometric and Genetic Variation an Three Freshwater Fish Species of the Genus Garra (Osteichthyes: Cyprinidae

    Directory of Open Access Journals (Sweden)

    Arulraj DHINAKARAN

    2011-03-01

    Full Text Available The present study evaluated the patterns of morphometric and genetic variation using RAPD-PCR techniques for the first time on three species of Garra, viz. G. mullya, G. kalakadensis and G. gotyla stenorhynchus, collected from various river basins of South-India. The results of morphological analysis revealed that G. mullya and G. kalakadensis hold many similar characters compared to the other congener, G. gotyla stenorhynchus. However, the G. gotyla stenorhynchus fish species exhibited distinct variation in the morphological characters such as snout length, pre-nasal length, inter-nasal width, gap width, lower jaw to isthmus, head depth at pupil, dorsal fin length and disc width from the other two species of Garra. However, certain morphometric characters overlapped. Hence the RAPD finger printing was used to assess the levels of genetic variation in Garra spp. using RAPD-PCR technique. A total of 72 reliable fragments were detected using 10 Operon primers, ranging from 2600 molecular weight to 3100. The shared RAPD fragments found in both G. mullya and G. kalakadensis with fixed frequencies were observed with all the investigated primers, implying their genetically closer relationship. However, the similarity index observed for G. gotyla stenorhynchus was less with the other two species specifying a genetically distant link. The present investigation thus contribute to the knowledge on morphological and genetic variation in these three Garra species.

  7. Assessment of Morphometric and Genetic Variation in Three Freshwater Fish Species of the Genus Garra (Osteichthyes: Cyprinidae

    Directory of Open Access Journals (Sweden)

    Arulraj DHINAKARAN

    2011-03-01

    Full Text Available The present study evaluated the patterns of morphometric and genetic variation using RAPD-PCR techniques for the first time on three species of Garra, viz. G. mullya, G. kalakadensis and G. gotyla stenorhynchus, collected from various river basins of South-India. The results of morphological analysis revealed that G. mullya and G. kalakadensis hold many similar characters compared to the other congener, G. gotyla stenorhynchus. However, the G. gotyla stenorhynchus fish species exhibited distinct variation in the morphological characters such as snout length, pre-nasal length, inter-nasal width, gap width, lower jaw to isthmus, head depth at pupil, dorsal fin length and disc width from the other two species of Garra. However, certain morphometric characters overlapped. Hence the RAPD finger printing was used to assess the levels of genetic variation in Garra spp. using RAPD-PCR technique. A total of 72 reliable fragments were detected using 10 Operon primers, ranging from 2600 molecular weight to 3100. The shared RAPD fragments found in both G. mullya and G. kalakadensis with fixed frequencies were observed with all the investigated primers, implying their genetically closer relationship. However, the similarity index observed for G. gotyla stenorhynchus was less with the other two species specifying a genetically distant link. The present investigation thus contribute to the knowledge on morphological and genetic variation in these three Garra species.

  8. Exposure to an agricultural contaminant, 17β-trenbolone, impairs female mate choice in a freshwater fish.

    Science.gov (United States)

    Tomkins, Patrick; Saaristo, Minna; Allinson, Mayumi; Wong, Bob B M

    2016-01-01

    Despite the pivotal role sexual selection plays in population dynamics and broader evolutionary processes, the impact of chemical pollution on female mate choice is poorly understood. One group of chemical contaminants with the potential to disrupt the mechanisms of female mate choice is endocrine disrupting chemicals (EDCs); a broad class of environmental pollutants that can interfere with the endocrinology of organisms at extremely low concentrations. Recent research has revealed that estrogenic EDCs can affect female mate choice in fish, but the impact of androgenic EDC exposure is yet to be studied. To address this, we investigated the effects of an environmentally relevant concentration of trenbolone - an androgenic steroid used as a growth promoter in the cattle industry - on female mate choice in wild-caught guppies (Poecilia reticulata). We exposed male and female guppies to 17β-trenbolone for 21 days (measured concentration 4ng/L) via a flow-through system, and found that trenbolone-exposed female guppies spent less time associating with males, and were less choosy, compared to unexposed females. In contrast, trenbolone had no impact on male reproductive behavior or morphology. This is the first study to show that androgenic EDC exposure can disrupt female mate choice, highlighting the need for studies to investigate the behavioral impacts of environmental contaminants on both sexes. PMID:26466515

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

    Directory of Open Access Journals (Sweden)

    Luciano de Oliveira Garcia

    2008-01-01

    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.Neste estudo verificaram-se dados de temperaturas de água coletados pela CORSAN-RS de 1996 a 2004, em várias cidades do estado do Rio Grande Sul, sul do Brasil, e analisou-se a possibilidade de criação das principais espécies de peixe cultivadas no Brasil. A temperatura da água de 1996 a 2004 foi de 16 a 28ºC no verão, de 17 a 25ºC no outono, 14 a 17ºC (chegando a 9ºC nos meses mais frios no inverno e 14 a 21ºC na primavera. Espécies nativas deste estado, como o jundiá (Rhamdia quelen, traíra (Hoplias malabaricus, dourado

  10. Fish and Soup of Hubei Cuisine

    Institute of Scientific and Technical Information of China (English)

    1996-01-01

    I was very impressed by the delicious freshwater fish dish from the well-known Changjiang River and Dongting Lake, the first time I travelled to Hubei Province. Hubei is famous for its freshwater fish dishes since it has so many lakes. The steamed Wuchang fish is one. Wuchang fish is pure, tender and fat and is considered a first-class freshwater fish. Waiters in local restaurants usually bring the fresh Wuchang fish to the

  11. 大宗淡水鱼糜凝胶性质比较研究%Studies on Comparison of Gel Properties of Conventional Freshwater Fish Surimi Gel

    Institute of Scientific and Technical Information of China (English)

    张屹环; 夏文水

    2012-01-01

    Effects of thermal treatment and fermentation on gel properties of 7kinds of conventional freshwater fish surimi gel were investigated. The gel properties, whiteness, folding strength and water holding capacity of surimi gel were investigated for the comparison of 7 kinds of conventional freshwater fish surimi gel which were processed by thermal treatment and fermentation, including black carp, grass carp, silver carp, bighead carp, common carp, crucian and gurnard. The breaking strength and gel strength of common carp surimi gel by thermal treatment were highest, respectively was 771. 83 g、7 733. 86 gmm. The breaking strength, deformation and gel strength of crucian surimi gel were lowest, 484. 77 g、7. 56 mm, 3 667. 38 gmm. Among fermented surimi gel, the breaking strength, deformation and gel strength of sliver carp surimi gel were highest, up to 908. 22 g、13. 20 mm、11 995. 08 gmm. The deformation and gel strength of sliver black carp surimi gel were lowest, 9.87 mm、6 690. 96 gmm respectively. The differences of water holding capacity and whiteness among different species were significant. Compared with the traditional thermal treated surimi gel, the gel properties of fermented surimi gel were higher, and its breaking strength, deformation and gel strength were enhanced to a certain extent. The increase of silver carp surimi gel was highest, 64.88%, 11.86%, 83.37% respectively.%研究热处理和发酵两种处理方法对7种淡水鱼糜凝胶性质的影响.以青、草、鲢、鳙、鲤、鲫、鲂7种大宗淡水鱼为原料制备鱼糜,比较热处理和发酵两种处理方法制备的7种淡水鱼糜凝胶的凝胶强度、白度、折叠强度和持水性等.热处理鱼糜凝胶中,鲤鱼糜凝胶的破断强度、凝胶强度最高,分别为771.83 g、7733.86 g?mm;鲫鱼糜凝胶的破断强度、凹陷深度、凝胶强度最低,为484.77 g、7.56 mm、3667.38 g?mm;发酵鱼糜凝胶中,鲢鱼糜凝胶的破断强度、凹陷深

  12. Transfers to freshwater biota

    International Nuclear Information System (INIS)

    It remains important to monitor the fate of radionuclides, particularly in environmental compartments that comprise human pathways. Therefore, an extensive literature survey has been conducted to compile available data on the transfer of radionuclides and their analogues to edible freshwater biota. Focus was placed on compilation of steady state transfer parameters for two freshwater pathways, including water-to-biota and sediment-to-biota. In general, although in many cases, extensive data were available for fishes and invertebrates, relatively fewer data were available for freshwater primary producers, amphibians and reptiles. To fill in these gaps, data were also compiled on the internal partitioning of elements in the body with respect to tissue masses, which could be used to estimate radionuclide concentrations between compartments in the body. (author)

  13. Screening and characterization of sex-specific DNA fragments in the freshwater fish matrinchã, Brycon amazonicus (Teleostei: Characiformes: Characidae).

    Science.gov (United States)

    da Silva, Eder Marques; Wong, Marina Sek Lien; Martins, Cesar; Wasko, Adriane Pinto

    2012-10-01

    The matrinchã Brycon amazonicus, a commercially important freshwater fish resource, has no heteromorphic sex chromosomes so far described. In the present study, we performed a screening of sex-associated DNA markers in this species, through the use of a random amplified polymorphic DNA (RAPD) assay and a genomic DNA restriction digestion analysis. DNA digestions evidenced no differences between sexes. Sixty-six random primers were used in pooled and individual DNA samples of males and females, and the analysis of the RAPD fingerprints revealed one female sex-associated band. Cloning and sequencing of this band led to the identification of two distinct DNA segments. While one of the isolated fragments showed a significant identity with a described protein gene (phosphatidylinositol glycan anchor biosynthesis, class W), the other fragment, composed of 535 bp, corresponds to a novel DNA marker. Further experiments were performed with this second DNA fragment in order to verify its sex-specificity. Data on dot blot hybridization, using total DNA of both sexes, confirmed its female-specificity in B. amazonicus. A primer set was designed based on its sequence data and used in PCR with DNA samples of this species, leading to diagnose the animals' sexes with a 100 % overall accuracy through a sequence characterized amplified region approach. No amplification results were found for two other species of the genus--B. orbignyanus and B. lundii. The obtained data can lead to the hypothesis that B. amazonicus may present heteromorphic sex chromosomes that should be in an early phase of differentiation. PMID:22527611

  14. Assessing species boundaries using multilocus species delimitation in a morphologically conserved group of neotropical freshwater fishes, the Poecilia sphenops species complex (Poeciliidae).

    Science.gov (United States)

    Bagley, Justin C; Alda, Fernando; Breitman, M Florencia; Bermingham, Eldredge; van den Berghe, Eric P; Johnson, Jerald B

    2015-01-01

    Accurately delimiting species is fundamentally important for understanding species diversity and distributions and devising effective strategies to conserve biodiversity. However, species delimitation is problematic in many taxa, including 'non-adaptive radiations' containing morphologically cryptic lineages. Fortunately, coalescent-based species delimitation methods hold promise for objectively estimating species limits in such radiations, using multilocus genetic data. Using coalescent-based approaches, we delimit species and infer evolutionary relationships in a morphologically conserved group of Central American freshwater fishes, the Poecilia sphenops species complex. Phylogenetic analyses of multiple genetic markers (sequences of two mitochondrial DNA genes and five nuclear loci) from 10/15 species and genetic lineages recognized in the group support the P. sphenops species complex as monophyletic with respect to outgroups, with eight mitochondrial 'major-lineages' diverged by ≥2% pairwise genetic distances. From general mixed Yule-coalescent models, we discovered (conservatively) 10 species within our concatenated mitochondrial DNA dataset, 9 of which were strongly supported by subsequent multilocus Bayesian species delimitation and species tree analyses. Results suggested species-level diversity is underestimated or overestimated by at least ~15% in different lineages in the complex. Nonparametric statistics and coalescent simulations indicate genealogical discordance among our gene tree results has mainly derived from interspecific hybridization in the nuclear genome. However, mitochondrial DNA show little evidence for introgression, and our species delimitation results appear robust to effects of this process. Overall, our findings support the utility of combining multiple lines of genetic evidence and broad phylogeographical sampling to discover and validate species using coalescent-based methods. Our study also highlights the importance of testing for

  15. Discrimination of freshwater fish species by Matrix-Assisted Laser Desorption/Ionization- Time Of Flight Mass Spectrometry (MALDI-TOF MS: a pilot study

    Directory of Open Access Journals (Sweden)

    Rosaria Lauceri

    2012-01-01

    Full Text Available In this study we discriminate three freshwater fish species (the shad Alosa agone Scopoli 1786, the whitefish Coregonus macrophthalmus Nüsslin1882 and the roach Rutilus rutilus Linnaeus 1758 by Matrix-Assisted Laser Desorption/Ionization- Time Of Flight Mass Spectrometry (MALDI-TOF MS using both muscle and liver tissues. The technology enables to analyze tissues after a simple single-step extraction procedure without any further purification. The molecular profile of muscle tissues showed the most intense peaks at m/z range of 11,354.0 (±2.0 SD Da, 3508.5 (±1.5 SD Da and 8567.2 (±1.1 SD Da for the shad, the whitefish and the roach respectively. The molecular profiles of liver tissues exhibit most of the highest peak intensities in the range between 2000 and 6000 m/z values. The roach shows the clearest pattern with high intensities detected at mass ranges between 3000 and 3550 Da with maxima at m/z 3035.2 (±0.2 Da and 3468.7 (±0.3 Da. The shad shows a shared high peak at m/z 3429.0 (±0.3 Da. The whitefish shows a group of major peaks in the m/z range of 3000-3700 Da with the highest being at 3635 (±0.3 Da. The overall signal pattern generated is highly specific for each species and, according to cluster analyses based on the total number of peaks, we could discriminate the three species.

  16. Assessing species boundaries using multilocus species delimitation in a morphologically conserved group of neotropical freshwater fishes, the Poecilia sphenops species complex (Poeciliidae.

    Directory of Open Access Journals (Sweden)

    Justin C Bagley

    Full Text Available Accurately delimiting species is fundamentally important for understanding species diversity and distributions and devising effective strategies to conserve biodiversity. However, species delimitation is problematic in many taxa, including 'non-adaptive radiations' containing morphologically cryptic lineages. Fortunately, coalescent-based species delimitation methods hold promise for objectively estimating species limits in such radiations, using multilocus genetic data. Using coalescent-based approaches, we delimit species and infer evolutionary relationships in a morphologically conserved group of Central American freshwater fishes, the Poecilia sphenops species complex. Phylogenetic analyses of multiple genetic markers (sequences of two mitochondrial DNA genes and five nuclear loci from 10/15 species and genetic lineages recognized in the group support the P. sphenops species complex as monophyletic with respect to outgroups, with eight mitochondrial 'major-lineages' diverged by ≥2% pairwise genetic distances. From general mixed Yule-coalescent models, we discovered (conservatively 10 species within our concatenated mitochondrial DNA dataset, 9 of which were strongly supported by subsequent multilocus Bayesian species delimitation and species tree analyses. Results suggested species-level diversity is underestimated or overestimated by at least ~15% in different lineages in the complex. Nonparametric statistics and coalescent simulations indicate genealogical discordance among our gene tree results has mainly derived from interspecific hybridization in the nuclear genome. However, mitochondrial DNA show little evidence for introgression, and our species delimitation results appear robust to effects of this process. Overall, our findings support the utility of combining multiple lines of genetic evidence and broad phylogeographical sampling to discover and validate species using coalescent-based methods. Our study also highlights the

  17. Identification method of freshwater fish species using multi-kernel support vector machine with bee colony optimization%基于蜂群优化多核支持向量机的淡水鱼种类识别

    Institute of Scientific and Technical Information of China (English)

    吴一全; 殷骏; 戴一冕; 袁永明

    2014-01-01

    为了准确地进行淡水鱼种类自动识别,利用计算机视觉技术,提出了一种基于 Krawtchouk 矩、灰度共生矩阵、蜂群优化多核最小二乘支持向量机(least squares support vector machine,LS-SVM)的识别方法。首先获取淡水鱼样本的灰度图像,计算淡水鱼鱼体的长宽比、鱼头鱼尾的 Krawtchouk 矩不变量形状特征,求得鱼身的灰度共生矩阵纹理特征,将上述形状与纹理特征组合成高维特征向量,并输入到多核LS-SVM,通过人工蜂群(artificial bee colony,ABC)算法对多核LS-SVM中的待定参数进行寻优,ABC算法中的适应度函数为测试样本的识别精度;最后输出识别精度达到最高时的最优参数。利用该方法对鳊鱼、鳙鱼、鲫鱼、草鱼、青鱼5种淡水鱼进行了分类识别,对鳊鱼、鳙鱼、鲫鱼、草鱼4种鱼识别时,各类鱼的识别精度均达到95.83%以上,对鳊鱼、鳙鱼、鲫鱼、青鱼4种鱼识别时,各类鱼的识别精度均达到91.67%以上,对鳊鱼、鳙鱼、鲫鱼、草鱼和青鱼5种鱼识别时,各类鱼的识别精度均达到83.33%以上;与近年来提出的淡水鱼识别方法、BP(back propagation)神经网络方法、单核LS-SVM方法相比,该方法的识别精度更高,从而可快速准确地识别淡水鱼的种类,提高水产养殖的自动化水平。%Currently, the identification of freshwater fish species is conducted by people. Computer vision techniques can solve problems existing in identification by hand, such as a large amount of work and low precision. Firstly, freshwater fish are converted into an image signal. Then images are transmitted to the computer processing system to be analyzed and processed. The features of freshwater fish images are extracted, and the movements of the equipment are controlled according to the features. As a result, the production efficiency and production quality are improved by this substitute

  18. Biochemical and genetic alterations in the freshwater neotropical fish Prochilodus lineatus after acute exposure to Microcystis aeruginosa

    Directory of Open Access Journals (Sweden)

    Cylene Zambrozi Garcia

    2012-09-01

    Full Text Available Microcystins are secondary metabolites produced by different species of cyanobacteria, such as Microcystis aeruginosa (MA. In this study, the biochemical and genetic effects of lyophilized MA were evaluated in the neotropical fish Prochilodus lineatus exposed to 1 or 2 mg L-1 lyophilized MA (treated group or only water (control group in static toxicity tests for 24 and 96 h. The gills and liver were used in the analysis of biotransformation enzymes and antioxidant defenses, blood and gill cells in genetic analysis and in brain and muscle it was determined the activity of acetylcholinesterase (AChE. The results showed the biotransformation pathway activation due to the increase in hepatic CYP1A and in branchial and hepatic glutathione S-transferase (GST. The antioxidant defense proved to be greatly affected by MA exposure leading to changes, both in gills and liver, in the activities of superoxide dismutase (SOD, catalase (CAT, glutathione peroxidase (GPx, glutathione reductase (GR and in the content of tripeptide glutathione (GSH. Lipid peroxidation was not detected, but damage to DNA molecule was observed in blood cells. In conclusion, it can be state the lyophilized MA is able to promote changes in the biochemical and genetic parameters of P. lineatus.As microcistinas são metabólitos secundários produzidos por diferentes espécies de cianobactérias, como a Microcystis aeruginosa (MA. Neste estudo, os efeitos bioquímicos e genéticos de liofilizado de MA foram avaliados para juvenis da espécie de peixe Neotropical Prochilodus lineatus expostos a 1 ou 2 mg L-1 de liofilizado de MA (grupo tratado ou apenas à água (grupo controle, em testes de toxicidade estáticos, durante 24 e 96 h. As brânquias e o fígado foram usados para as análises das enzimas de biotransformação e defesas antioxidantes, células do sangue e das brânquias para análises genéticas e no cérebro e músculo foi determinada a atividade da acetilcolinesterase (ACh

  19. Piscicultura continental no Rio Grande do Sul: situação atual, problemas e perspectivas para o futuro Freshwater fish culture in Rio Grande do Sul State: actual situation, problems and future perspectives

    Directory of Open Access Journals (Sweden)

    Bernardo Baldisserotto

    2009-02-01

    Full Text Available Esta revisão aborda a situação da piscicultura continental no Rio Grande do Sul nos últimos anos em termos de produção e problemas enfrentados pelo setor. Além disso, apresenta algumas perspectivas futuras para a piscicultura continental neste Estado. O Rio Grande do Sul contribui com uma boa porcentagem da produção brasileira de piscicultura continental, mas passa por um período de estagnação nos últimos anos. Há um predomínio muito grande de espécies de peixes exóticas na produção (principalmente carpas. A venda de peixes concentra-se no período que antecede à Páscoa e a fiscalização sanitária ainda é reduzida. Produtores estão iniciando a formação de cooperativas na região central do Rio Grande do Sul. A publicação de livros sobre cultivo de espécies nativas e a estagnação da produção pesqueira extrativa continental nos últimos anos pode favorecer a criação de espécies nativas, das quais várias são sugeridas nesta revisão. A criação de espécies nativas para venda como peixe ornamental ainda é uma opção a ser explorada no futuro pelos piscicultores deste Estado.This review deals with freshwater fish culture in Rio Grande do Sul State, southern Brazil, and analyzes production and problems of this activity in the last years. This State contributes with a good percentage of Brazilian freshwater fish culture, but its production has been stagnated in the last years. Production is based essentially on exotics fish species (mainly carps. Fish sales are concentrated in the Easter period, and sanitary inspection is still reduced. Fish farmers are making cooperatives in the central region of Rio Grande do Sul. The publishing of books of native species and the freshwater fisheries stagnation in the last years may stimulate the raise of native species, and some are suggested in this review. The culture of native species to be sold as ornamental fishes is still a future option for fish farmers of this State.

  20. Evaluation and Choice of Organization Model of Freshwater Fish Circulation in China%我国淡水鱼流通组织模式评价与选择

    Institute of Scientific and Technical Information of China (English)

    李晓红; 金兆国; 卢凤君

    2012-01-01

    结合实地调查,按组织化程度高低把我国淡水鱼流通组织模式分成了企业产运销一体化型、市场交易型和联盟合作型三种类型,并从质量保障能力、数量保障能力、成本竞争优势、快速供应市场能力、节能减排优势五个方面对各模式进行了评价.最后提出了针对火宗淡水鱼、特优淡水鱼以及品牌化淡水鱼流通的组织模式选择策略。%Based on with field investigation, according to the degree of organization, this paper differentiates the organization model oft freshwater fish circulation into three types: market transaction, 'alliance cooperation and product-transport-sale integration, and these models are evaluated in terms of five aspects, such as the quality assurance capacity, quantity guarantee ability, cost competitive advantage, rapid supply market capacity, energy saving and emission reduction. Finally, the paper puts forward circulation organization mode choice strategies of a large amount of frcshwater fish. endemic species and the brand of freshwater fish.

  1. Fishing

    Institute of Scientific and Technical Information of China (English)

    姜群山

    2002-01-01

    @@ Last Saturday my cousin (表兄) came to my home. We were very happy to see each other. We decided that the next day we went to fish. We got up very early that day. When we left home,the moon could still be seen in the sky.

  2. Do the historical biogeography and evolutionary history of the digenean Margotrema spp. across central Mexico mirror those of their freshwater fish hosts (Goodeinae?

    Directory of Open Access Journals (Sweden)

    Andrés Martínez-Aquino

    Full Text Available Host-parasite systems provide an ideal platform to study evolution at different levels, including codivergence in a historical biogeography context. In this study we aim to describe biogeographic and codivergent patterns and associated processes of the Goodeinae freshwater fish and their digenean parasite (Margotrema spp. over the last 6.5 Ma (million years, identifying the main factors (host and/or hydrogeomorphology that influenced the evolution of Margotrema. We obtained a species tree for Margotrema spp. using DNA sequence data from mitochondrial and nuclear molecular markers (COI and ITS1, respectively and performed molecular dating to discern divergence events within the genus. The dispersal-extinction-cladogenesis (DEC model was used to describe the historical biogeography of digeneans and applied to cophylogenetic analyses of Margotrema and their goodeine hosts. Our results showed that the evolutionary history of Margotrema has been shaped in close association with its geographic context, especially with the geological history of central Mexico during the Pleistocene. Host-specificity has been established at three levels of historical association: a Species-Species, represented by Xenotaenia resolanae-M. resolanae exclusively found in the Cuzalapa River Basin; b Species-Lineage, represented by Characodon audax-M. bravoae Lineage II, exclusive to the Upper and Middle Mezquital River Basin, and c Tribe-Lineage, including two instances of historical associations among parasites and hosts at the taxonomical level of tribe, one represented by Ilyodontini-M. bravoae Lineage I (distributed across the Ayuquila and Balsas River Basins, and another comprised of Girardinichthyini/Chapalichthyini-M. bravoae Lineage III, found only in the Lerma River Basin. We show that the evolutionary history of the parasites is, on several occasions, in agreement with the phylogenetic and biogeographic history of their hosts. A series of biogeographic and host

  3. 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

    2009-01-01

    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.A reprodução sazonal de peixes tropicais de água doce pode estar sincronizada com períodos de alto consumo de alimento. Nós examinamos esta hipótese estudando a relação entre dieta e atividade reprodutiva de Creagrutus guanes (Teleostei, Characidae. Nossos resultados mostraram que C. guanes teve uma dieta generalista e onívora, com predominância de insetos aquáticos (principalmente larva de Diptera e sementes. Creagrutus guanes não apresentou variação intersexual ou ontogenética na dieta. Picos de atividade alimentar durante os meses chuvosos não foram sincronizados com atividade reprodutiva nos meses secos. Nossos resultados não sustentam a hipótese de que a estação reprodutiva está sincronizada com o consumo elevado de alimento. A reserva de gordura pode ser um fator importante para a dessincronização de picos de alimentação e reprodução (a reserva de gordura pode influenciar a ausência de sincronia entre os picos de alimentação e reprodução. São apresentadas hipóteses alternativas para a explicação de desova sazonal da espécie

  4. North Slope, Alaska ESI: FISH (Fish Polygons)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for marine, estuarine, anadromous, and freshwater fish species for the North Slope of Alaska. Vector...

  5. Report on some monogenean and clinostomid infestations of freshwater fish and waterbird hosts in Middle Letaba Dam, Limpopo Province, South Africa.

    Science.gov (United States)

    Olivier, P A S; Luus-Powell, Wilmien J; Saayman, J E

    2009-06-01

    This report deals with the results of a parasitological study done as part of a post-impoundment ecological study of Middle Letaba Dam, Limpopo Province, South Africa. It involved a seasonal survey protocol with particular attention to the diversity and prevalence of the parasitic fauna of the indigenous fish community of the dam and the role of selected fish-eating birds in the life cycle and distribution of fish helminths. The potential species composition of fish of the dam is provided. Monogenean and clinostomatid parasites encountered are listed and infestation statistics of fish and fish-eating bird hosts are presented. The results of this study also provide information on new distribution and host records of the encountered monogeneans. PMID:20698439

  6. Report on some monogenean and clinostomid infestations of freshwater fish and waterbird hosts in Middle Letaba Dam, Limpopo Province, South Africa

    Directory of Open Access Journals (Sweden)

    P.A.S. Olivier

    2009-09-01

    Full Text Available This report deals with the results of a parasitological study done as part of a post-impoundment ecological study of Middle Letaba Dam, Limpopo Province, South Africa. It involved a seasonal survey protocol with particular attention to the diversity and prevalence of the parasitic fauna of the indigenous fish community of the dam and the role of selected fish-eating birds in the life cycle and distribution of fish helminths. The potential species composition of fish of the dam is provided. Monogenean and clinostomatid parasites encountered are listed and infestation statistics of fish and fish-eating bird hosts are presented. The results of this study also provide information on new distribution and host records of the encountered monogeneans.

  7. Estimation of Seasonal Risk Caused by the Intake of Lead, Mercury and Cadmium through Freshwater Fish Consumption from Urban Water Reservoirs in Arid Areas of Northern Mexico

    OpenAIRE

    Myrna Nevárez; Leal, Luz O.; Myriam Moreno

    2015-01-01

    Bioavailability and hence bioaccumulation of heavy metals in fish species depends on seasonal conditions causing different risks levels to human health during the lifetime. Mercury, cadmium and lead contents in fish from Chihuahua (Mexico) water reservoirs have been investigated to assess contamination levels and safety for consumers. Muscle samples of fish were collected across the seasons. Lead and cadmium were analyzed by inductively coupled plasma-optical emission spectrometry, and mercur...

  8. 市售淡水鱼中孔雀石绿及其代谢物残留量的调查研究%Monitoring malachite green and its metabolites leumalachite green in retailed freshwater fish

    Institute of Scientific and Technical Information of China (English)

    华永有; 邱文倩; 周亮; 吕华东; 郑奎城; 黄宏南; 林宏琳; 傅武胜

    2011-01-01

    Objective To monitor and assess the residues of malachite green (MC) and its metabolites leucomalachite green (LMG) in freshwater fish. Methods Twenty eight kinds of 207 fish samples were collected from retailers in six cities of Fujian Province. After samples being homogenized and pre-treated, the concentration of total MG in samples was quantified by high performance liquid chromatography ( HPLC) coupled with fluorescence detector. The positive samples analyzed by HPLC were confirmed by HPLC-mass spectrometer ( LC/MS/MS ). Results The detection rate of MG was 23.2% (48/207) with levels ranged from 0.54 to 8 099μg/kg in samples. MG was detected in 92.9% (26/28) of Chinese perch and in 2. 38% of grass carp. Conclusion The detection rate of MG in freshwater fish sold in Fujian markets was relatively high, especially in Chinese perch. It is indicated that the illegal application of MG in supply chains for freshwater fish may be relatively serious. Strengthening surveillance and regulation for attacking illegal application of MG should be promoted to ensure the safety of consuming freshwater fish.%目的 了解福建省餐饮环节淡水鱼孔雀石绿(MG)及其代谢物无色孔雀石绿(LMG)的残留情况.方法207份样品来自福建省6个市有关餐饮场所,共28个品种,制作为鱼肉浆,经前处理后,采用高效液相色谱/荧光法对鱼内浆中孔雀石绿及其代谢物的残留总量进行检测,阳性样品再用高效液相色谱/质谱法确证.结果 15个品种的48份样品检出孔雀石绿及其代谢物,检出率为23.2%,总MG含量在0.54~8 099μg/kg之间.桂花鱼检出率最高,达到92.9% (26/28),草鱼检出率较低,为2.38% (2/84).结论 餐饮环节销售的淡水鱼孔雀石绿及其代谢物的检出率相对较高,在某些品种淡水鱼供应链中滥用MG的现象较为突出,需要有关监管部门加大打击滥用MG的力度,确保淡水鱼的消费安全.

  9. Broad-scale sampling of primary freshwater fish populations reveals the role of intrinsic traits, inter-basin connectivity, drainage area and latitude on shaping contemporary patterns of genetic diversity.

    Science.gov (United States)

    Sousa-Santos, Carla; Robalo, Joana I; Pereira, Ana M; Branco, Paulo; Santos, José Maria; Ferreira, Maria Teresa; Sousa, Mónica; Doadrio, Ignacio

    2016-01-01

    Background. Worldwide predictions suggest that up to 75% of the freshwater fish species occurring in rivers with reduced discharge could be extinct by 2070 due to the combined effect of climate change and water abstraction. The Mediterranean region is considered to be a hotspot of freshwater fish diversity but also one of the regions where the effects of climate change will be more severe. Iberian cyprinids are currently highly endangered, with over 68% of the species raising some level of conservation concern. Methods. During the FISHATLAS project, the Portuguese hydrographical network was extensively covered (all the 34 river basins and 47 sub-basins) in order to contribute with valuable data on the genetic diversity distribution patterns of native cyprinid species. A total of 188 populations belonging to 16 cyprinid species of Squalius, Luciobarbus, Achondrostoma, Iberochondrostoma, Anaecypris and Pseudochondrostoma were characterized, for a total of 3,678 cytochrome b gene sequences. Results. When the genetic diversity of these populations was mapped, it highlighted differences among populations from the same species and between species with identical distribution areas. Factors shaping the contemporary patterns of genetic diversity were explored and the results revealed the role of latitude, inter-basin connectivity, migratory behaviour, species maximum size, species range and other species intrinsic traits in determining the genetic diversity of sampled populations. Contrastingly, drainage area and hydrological regime (permanent vs. temporary) seem to have no significant effect on genetic diversity. Species intrinsic traits, maximum size attained, inter-basin connectivity and latitude explained over 30% of the haplotype diversity variance and, generally, the levels of diversity were significantly higher for smaller sized species, from connected and southerly river basins. Discussion. Targeting multiple co-distributed species of primary freshwater fish allowed

  10. Freshwater Wetlands.

    Science.gov (United States)

    Naturescope, 1986

    1986-01-01

    Provides descriptions about freshwater wetlands, such as marshes, swamps, and bogs. Contains three learning activities which deal with unusual wetland plants, the animals and plants in a typical marsh, and the effects of a draught on a swamp. Included are reproducible handouts and worksheets for two of the activities. (TW)

  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 areas…

  12. Accumulation of heavy metals and human health risk assessment via the consumption of freshwater fish Mastacembelus armatus inhabiting, thermal power plant effluent loaded canal.

    Science.gov (United States)

    Javed, Mehjbeen; Usmani, Nazura

    2016-01-01

    Bioaccumulation of six heavy metals (Mn, Fe, Co, Ni, Cu, Zn) in the muscle of highly consumed fish species (Mastacembelus armatus) were measured using atomic absorption spectrometer. Fe (213.29 mg/kg dry weight) concentration was the most, followed by Zn (186.19 mg/kg dry weight), Ni (58.98 mg/kg dry weight), Cu (41.36 mg/kg dry weight), Co (9.06 mg/kg dry weight) and Mn (9.03 mg/kg dry weight). Estimated daily intake of heavy metals was calculated by mean fish consumption rate 19.5 × 10(-3) kg/day, on the basis of a calculation of the amount of fish consumed by adult individuals (male and female). The studied fish species pose non carcinogenic risk for Co and Ni [target hazard quotient (THQ) > 1] only. Hazard index (HI) was high. Carcinogenic risk (TR) posed by this fish for male and female was 3.43 × 10(-3) and 3.91 × 10(-3), respectively for Ni (the carcinogenic potency slope factor was available for Ni only). The study is an alert indicating that inhabitants who consume these fishes (particularly females) were at risk of Co and Ni toxicity. In India recommended guidelines have yet not been established for these heavy metals, which is essential for setting of toxicological standards. PMID:27386262

  13. Effects of Chopping on Chloramphenicol Residues and Quality of Freshwater Fish%斩拌对淡水鱼肉品质及氯霉素残留的影响

    Institute of Scientific and Technical Information of China (English)

    梁丽雅; 王綪; 王婧; 杨毅青; 马俪珍; 闫师杰

    2014-01-01

    以鲢鱼、鲤鱼和鲶鱼肉为试材,研究斩拌工序对鱼肉品质及氯霉素残留量的影响。结果表明:经斩拌后,鱼肉中蛋白质含量呈下降趋势,鲤鱼显著低于鲢鱼和鲶鱼;自由水峰面积减少,不易流动水峰面积增加,不同斩拌处理的鱼肉水分分布差异不显著;脂肪含量差异不显著;HL斩拌的鱼肉灰分和蛋白质损失量最小。斩拌对鱼肉L*和a*值影响较小,使pH不同程度地升高(6.5~7.5);HL斩拌可显著降低TBARS值。经斩拌氯霉素残留降解率达73.33%~99.13%。斩拌可有效去除氯霉素残留,经HL斩拌后的鱼肉品质最佳。%With silver carp, carp, and catfish flesh as the experimental material,effects of chopping processing on the quality and chloramphenicol residues of freshwater fish were studied. The results showed that after chopped, that protein content of fish flesh showed a downward trend, the value of carp flesh was significantly lower than that of chub and catfish;Free-water content decreased, immobilized-water content increased, and water distribution of different chopping was not significant. The difference of fat content between them was not significant;the ash and protein yield loss in fish flesh was least by HL chopping. The chopping had less affection on L*and a*value of fish flesh. The pH of fish flesh increased in different degrees (6.5-7.5);TBARS values of chub and carp decreased significantly, but the catfish raised by HL chopping. Degradation rate of chloramphenicol residues was 77.33%-99.13%. Chopping can effectively get rid of the chloramphenicol residue , and the quality of fish flesh was the best by HL chopping.

  14. CROATIAN FRESHWATER FISHERIES IN 1996.

    Directory of Open Access Journals (Sweden)

    Mirko Turk

    1997-07-01

    Full Text Available Data on the production and fish catch according to species, on the surface of the fish ponds, on the means of fish catching and on the distribution of the production and the catch in 1996 is presented. The surface area used for production of fish has decreased by 1357 ha or 11.99%. The total fish amount has decreased by 1,921.00 tons or 29.76%. The feeding coefficient is 4 kg (33.33% bigger compared to the previous year. The amount of the fertilizer used has decreased by 18.79%. The fry carp growing ponds make up 5.99% of the total fish pond surfaces, the young carp ponds 21.13%, and the ponds with consumption fish 71.53%. The total fish amount in the carp ponds was 376 kg/ha, and in the trout ponds it was 146.6 tons/ha. The most produced fish species is the carp with 82.21 %, followed by the trout with 8.57%, the herbivorous fish with 4.78%, while all the other fish species make up 4.44% of the entire production. In the structure of herbivorous fish the grass carp is leading with 64,28%, followed by the big head carp with 26.02% and the silver carp with 9.70%. Compared to the previous year the production of the trout and tench has somewhat increased, while the production of all the other species of fish has decreased. Fish catch in open waters has increased by 19.23% in comparison to the previous year. In the production and catch of the total freshwater fish, carp made up 77.46%, the herbivorous fish made up 4.32%, trout 4.32%, sheat fish, pike perch and pike 2.99% and all other fish species 7.36%. As far as the distribution of production and catch is concerned, 46.91% were sold on the market, 39.19% were used for reproduction (stocking the fish farms, mortalities were 6.23%, and for personal use (sports fishing 7.67% was used. The number of fisheries workers has decreased by 17.75%, and the production per worker has also decreased by 26.62%, compared to the previous year. Average production per worker was 5.87 tons of fish.

  15. Disturbance cues in freshwater prey fishes: Does urea function as an ‘early warning cue’in juvenile convict cichlids and rainbow trout?

    Directory of Open Access Journals (Sweden)

    Grant E. BROWN, Christopher D. JACKSON, Patrick H. MALKA,Élisa JACQUES, Marc-Andre COUTURIER

    2012-04-01

    Full Text Available Freshwater vertebrate and invertebrate prey species commonly rely on chemosensory information, including non-injury released disturbance cues, to assess local predation threats. We conducted laboratory studies to (1 determine if urea can function as a disturbance cue in juvenile convict cichlids and rainbow trout and (2 determine if the background level of urea influences the behavioral response to a subsequent pulse of urea (‘background noise’ hypothesis. In the first series of trials, juvenile cichlids and trout were exposed to urea at varying concentrations (0 to 0.5 mg L-1 for cichlids and 0 to 1.0 mg L-1 for trout. Our results suggest that both cichilds and trout exhibited functionally similar responses to urea and conspecific disturbance cues and that increasing the concentration of urea results in an increase intensity of antipredator behaviour. In the second series of trials, we pre-exposed cichlids or trout to intermediate or high concentrations of urea (or a distilled water control and then tested for the response to a second pulse of urea at at intermediate or high concentrations (versus a distilled water control. Our results demonstrate that pre-exposure to urea reduces or eliminates the response to a second pulse of urea, supporting the background noise hypothesis. Together, our results suggest that pulses of urea, released by disturbed or stressed individuals, may function as an early warning signal in freshwater prey species [Current Zoology 58 (2: 250–259 , 2012].

  16. INDIRECT SAFETY ASSESSMENT OF ECTODERMAL MERCURY EXPOSURE BY TRADITIONAL MEDICAL FORMULATIONS ON FRESHWATER CAT FISH CLARIAS BATRACHUS USING MICRONUCLEUS ASSAY AND ALKALINE SINGLE-CELL GEL ELECTROPHORESIS (COMET ASSAY

    Directory of Open Access Journals (Sweden)

    Anand Prem Rajan

    2012-02-01

    Full Text Available Mercury and its salts are the major constituents of Ayurvedic, Chinese and Tibetan traditional formulations. The mercury is extensively reported to accumulate in food chain and cause many neurological disorders in environment. The safety assessment of mercury on the ectodermal application on animal model is rarely reported. The void in the scientific study on external exposure of mercury and its genotoxic inside the body lead to the necessity for the present study. The freshwater cat fish Clarias batrachus was used for broad specificity genotoxic indicators micronucleus assay and alkaline single-cell gel electrophoresis (comet assays. The fish was exposed to 0.03 ppm of mercuric chloride for a period of 7, 14, 28 and 35 days ectodermally. The blood sample was assayed for the genotoxicity. The results revealed undoubted DNA damage through the micronuclei and alkaline single-cell gel electrophoresis (comet assays. Hence it is concluded the usage of traditional medicines containing the mercury may be toxic at genetic level in prolonged usage.

  17. Within and between population variation in epidermal club cell investment in a freshwater prey fish: a cautionary tale for evolutionary ecologists.

    Directory of Open Access Journals (Sweden)

    Aditya K Manek

    Full Text Available Many prey fishes possess large club cells in their epidermis. The role of these cells has garnered considerable attention from evolutionary ecologists. These cells likely form part of the innate immune system of fishes, however, they also have an alarm function, releasing chemical cues that serve to warn nearby conspecifics of danger. Experiments aimed at understanding the selection pressures leading to the evolution of these cells have been hampered by a surprisingly large intraspecific variation in epidermal club cell (ECC investment. The goal of our current work was to explore the magnitude and nature of this variation in ECC investment. In a field survey, we documented large differences in ECC investment both within and between several populations of minnows. We then tested whether we could experimentally reduce variation in mean ECC number by raising fish under standard laboratory conditions for 4 weeks. Fish from different populations responded very differently to being held under standard laboratory conditions; some populations showed an increase in ECC investment while others remained unchanged. More importantly, we found some evidence that we could reduce within population variation in ECC investment through time, but could not reduce among-population variation in mean ECC investment. Given the large variation we observed in wild fish and our limited ability to converge mean cell number by holding the fish under standard conditions, we caution that future studies may be hard pressed to find subtle effects of various experimental manipulations; this will make elucidating the selection pressures leading to the evolution of the cells challenging.

  18. Within and between population variation in epidermal club cell investment in a freshwater prey fish: a cautionary tale for evolutionary ecologists.

    Science.gov (United States)

    Manek, Aditya K; Ferrari, Maud C O; Pollock, Robyn J; Vicente, Daniel; Weber, Lynn P; Chivers, Douglas P

    2013-01-01

    Many prey fishes possess large club cells in their epidermis. The role of these cells has garnered considerable attention from evolutionary ecologists. These cells likely form part of the innate immune system of fishes, however, they also have an alarm function, releasing chemical cues that serve to warn nearby conspecifics of danger. Experiments aimed at understanding the selection pressures leading to the evolution of these cells have been hampered by a surprisingly large intraspecific variation in epidermal club cell (ECC) investment. The goal of our current work was to explore the magnitude and nature of this variation in ECC investment. In a field survey, we documented large differences in ECC investment both within and between several populations of minnows. We then tested whether we could experimentally reduce variation in mean ECC number by raising fish under standard laboratory conditions for 4 weeks. Fish from different populations responded very differently to being held under standard laboratory conditions; some populations showed an increase in ECC investment while others remained unchanged. More importantly, we found some evidence that we could reduce within population variation in ECC investment through time, but could not reduce among-population variation in mean ECC investment. Given the large variation we observed in wild fish and our limited ability to converge mean cell number by holding the fish under standard conditions, we caution that future studies may be hard pressed to find subtle effects of various experimental manipulations; this will make elucidating the selection pressures leading to the evolution of the cells challenging. PMID:23469175

  19. Carbon Sink Function of Filter-feeding Fish in Freshwater Fisheries%滤食性鱼类在淡水渔业中的碳汇作用初探

    Institute of Scientific and Technical Information of China (English)

    陈中祥; 牟振波

    2011-01-01

    气候变暖威胁人类的生存与发展,减少CO2等温室气体的排放,发展低碳经济,缓解全球气候变暖的低碳经济是人类的共识。滤食性鱼类通过滤食浮游生物,间接降低大气中的CO2浓度而发挥碳汇作用。本文描述了一个不投饵的淡水生态系统的碳循环,探讨了滤食性鱼类在淡水生态系统中的碳汇作用,依据2009年全国水产养殖相关统计数据,估算了全国滤食性鱼类养殖的年碳汇量,为淡水渔业的低碳发展提供新思路,以推进现代化渔业的科学健康发展。%Climate warming has been a world-concerned global problem.It brings a series of serious consequences,greatly impacts human survival and development.To reduce carbon dioxide emissions and mitigate global warming,the development of the low carbon economy based on low energy consumption,low pollution and low emission has been our common sense.Fixing and sequestrating greenhouse gases by biological carbon sink is one of the most economical and effective ways.By filtering plankton,filter-feeding fish can reduce indirectly atmospheric carbon dioxide concentration and exert carbon sink function.The paper described carbon cycle of freshwater ecosystem without feeding,and presented carbon sink function of filter-feeding fish.At last,carbon sink amount of filter-feeding fish is evaluated based on 2009 relevant statistics of Chinese aquaculture.The research will make a good preparation for low carbon development of freshwater fisheries,and impel the scientific and healthy development of modern fisheries.

  20. 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%),

  1. 淡水鱼鱼糕加工适性和微冻特性的研究%Processed Characteristic and Superchilled Properties of Kamaboko Gels from Nine Different Kinds of Freshwater Fish

    Institute of Scientific and Technical Information of China (English)

    米红波; 千春录; 傲特海; 茅林春

    2012-01-01

    测定了草鱼、鲢鱼、鲫鱼、鲈鱼、鲑鱼、黑鱼、鳊鱼、鲶鱼、鳙鱼等9种淡水鱼的采肉率和成本,比较不同淡水鱼鱼糕的营养特性和品质差异,测定鱼糕微冻贮藏过程中细菌总数、挥发性盐基氮(TVB-N)和硫代巴比妥酸还原值(TBARS)的变化.试验结果表明,鲶鱼采肉率最高,所需成本最低.不同淡水鱼鱼糕总蛋白含量有显著差异(p<0.05),而含水量、脂肪和灰分含量差异不显著(p>0.05).草鱼鱼糕的硬度适中,弹性和凝聚性均优于其他种类淡水鱼鱼糕,咀嚼性和凝胶强度仅次于鲑鱼鱼糕,最适合作为淡水鱼鱼糜制品的加工原料.微冻与真空包装结合能明显延长鱼糕的货架期.草鱼鱼糕、鲢鱼鱼糕、黑鱼鱼糕和鳙鱼鱼糕的微冻保鲜期在56d以上.%Flesh percentage and cost of nine different kinds of freshwater fishes (grass carp, silver carp, crucian carp, perch fish, salmon, snakehead, bream, catfish and bighead) were determined. General nutrition composition and properties of kamaboko gels processed from these freshwater fishes were compared. Meanwhile, quality of kamaboko gels were evaluated in terms of aerobic bacterial count, total volatile basic nitrogen (TVB-N) and thiobarbituric acid reactive substances (TBARS) during superchilled storage at -2 ℃. Results indicated that catfish has the highest flesh percentage and lowest cost. There were no significant difference (p>0.05) in water content, fat content and ash content, while the total protein content of the kamaboko gels from the nine kinds of freshwater fishes was varied (p<0.05). Acceptable hardness, best springiness and cohesiveness were found in kamaboko gels prepared with grass carp, while the chewiness and gel strength were lower than salmon kamaboko gels. The shelf life of kamaboko gels could be prolonged significantly with superchilled storage and vacuum packaging. Kamaboko gels from grass carp, silver carp, snakehead and bighead could

  2. CROATIAN FRESHWATER FISHERIES IN 1997

    Directory of Open Access Journals (Sweden)

    Mirko Turk

    1998-10-01

    Full Text Available Data on the production and fish catch according to species, on the surface of the fish ponds, on the means of fish catching and on the distribution of the production and the catch in 1997 is presented. The surface area used for production of fish has decreased for 836 ha or 8.40%. The total fish amount was bigger for 477 tons, or 10,52%. The feeding coefficient is 2.6 kg decreased 35% for in comparison to the bigger compared to the previous year. The amount of the fertilizer used is bigger for 37.30%. The fry carp growing ponds make up 6.50% of the total fish pond surfaces, the young carp ponds 22.04/0, and the ponds with consumption fish 70.31%. The total amount in the carp ponds was 446 kg/ha, and in the trout ponds it was 160.8 tons/ha. The most produced fish species is the carp with 79.32%, followed by the trout with 11.50%, the herbivorous fish with 4.25%, while all the other fish species make up 4.93% of the entire production. In the structure of herbivorous fish the grass carp is leading with 69,23%, followed by the big head carp with 29.74% and the silver carp with 1.03%. Compared to the previous year the production of the carp, grass carp and tench is increased. Fish catch in open waters has decreased by 5.53% in comparison to the previous year. In the production and catch of the total freshwater fish, carp made up 75.34%, herbivorous fish made up 3.89%, trout 10.66%, sheat fish, pike perch and pike 2.70% and all other fish species 7.41%. As far as the distribution of production and catch of fish is concerned, 52,80% were sold on the market, 37.94% were used for reproduction (stocking the fish farms, mortality was 1.43%, and for personal use (sports fishing 7.83%. The number of fisheries workers has decreased for 8.17%, and the production per worker is bigger for 22.25%, compared to the previous year. Average production per worker was 7.17% tons of fish.

  3. Freshwater aquaculture in the United States: Complying with environmental protection law and policy

    OpenAIRE

    Noble, M.

    1993-01-01

    The author deal with the relations between the freshwater fish culture and the many regulations of the environmental protection in USA. The author develops the federal and state administrative frameworks (federal government administration of aquaculture, the state government administration of aquaculture), the freshwater aquaculture and water rights, the freshwater aquaculture and wetlands regulation, the freshwater aquaculture and water quality regulation, the freshwater aquaculture and wild...

  4. Estimation of seasonal risk caused by the intake of lead, mercury and cadmium through freshwater fish consumption from urban water reservoirs in arid areas of northern Mexico.

    Science.gov (United States)

    Nevárez, Myrna; Leal, Luz O; Moreno, Myriam

    2015-02-04

    Bioavailability and hence bioaccumulation of heavy metals in fish species depends on seasonal conditions causing different risks levels to human health during the lifetime. Mercury, cadmium and lead contents in fish from Chihuahua (Mexico) water reservoirs have been investigated to assess contamination levels and safety for consumers. Muscle samples of fish were collected across the seasons. Lead and cadmium were analyzed by inductively coupled plasma-optical emission spectrometry, and mercury by cold-vapor atomic absorption spectrometry. The highest concentrations of cadmium (0.235 mg/kg), mercury (0.744 mg/kg) and lead (4.298 mg/kg) exceeded the maximum levels set by European regulations and Codex Alimentarius. Lead concentrations found in fish from three water reservoirs also surpassed the limit of 1 mg/kg established by Mexican regulations. The provisional tolerable weekly intake (PTWI) suggested by the World Health Organization for methyl mercury (1.6 µg/kg bw per week) was exceeded in the spring season (1.94 µg/kg bw per week). This might put consumers at risk of mercury poisoning.

  5. Evaluation of metabolic enzymes in response to Excel Mera 71, a glyphosate-based herbicide, and recovery pattern in freshwater teleostean fishes.

    Science.gov (United States)

    Samanta, Palas; Pal, Sandipan; Mukherjee, Aloke Kumar; Ghosh, Apurba Ratan

    2014-01-01

    Metabolic enzymes such as alanine aminotransferase (ALT), aspartate aminotransferase (AST), and alkaline phosphatase (ALP) were evaluated in Indian teleostean fishes, namely, Anabas testudineus (Bloch) and Heteropneustes fossilis (Bloch), for an exposure to 30 days of Excel Mera 71 (17.2 mg/L), a glyphosate formulation, and subsequent depuration under Liv.52, a plant extract at a dose of 187.5 mg/d/250 L for the same period in the same tissues under laboratory condition. ALT activity was significantly increased (PExcel Mera 71 caused alterations in the metabolic enzymatic activities in fish tissues and AST showed the highest alteration in both the fishes, while lowest in ALP and ALT in A. testudineus and H. fossilis, respectively. During depuration under Liv.52, all the enzyme activities came down towards the control condition which indicated the compensatory response by the fish against this herbicidal stress and it was in the following order: AST>ALT>ALP, in A. testudineus, while H. fossilis showed the following trend: ALT>AST>ALP. Therefore, these parameters could be used as indicators of herbicidal pollution in aquatic organisms and were recommended for environmental monitoring for investigating the mechanism involved in the recovery pattern.

  6. Estimation of Seasonal Risk Caused by the Intake of Lead, Mercury and Cadmium through Freshwater Fish Consumption from Urban Water Reservoirs in Arid Areas of Northern Mexico

    Directory of Open Access Journals (Sweden)

    Myrna Nevárez

    2015-02-01

    Full Text Available Bioavailability and hence bioaccumulation of heavy metals in fish species depends on seasonal conditions causing different risks levels to human health during the lifetime. Mercury, cadmium and lead contents in fish from Chihuahua (Mexico water reservoirs have been investigated to assess contamination levels and safety for consumers. Muscle samples of fish were collected across the seasons. Lead and cadmium were analyzed by inductively coupled plasma-optical emission spectrometry, and mercury by cold-vapor atomic absorption spectrometry. The highest concentrations of cadmium (0.235 mg/kg, mercury (0.744 mg/kg and lead (4.298 mg/kg exceeded the maximum levels set by European regulations and Codex Alimentarius. Lead concentrations found in fish from three water reservoirs also surpassed the limit of 1 mg/kg established by Mexican regulations. The provisional tolerable weekly intake (PTWI suggested by the World Health Organization for methyl mercury (1.6 µg/kg bw per week was exceeded in the spring season (1.94 µg/kg bw per week. This might put consumers at risk of mercury poisoning.

  7. Effect of consumption of the nutrient-dense, freshwater small fish Amblypharyngodon mola on biochemical indicators of vitamin A status in Bangladeshi children: a randomised, controlled study of efficacy.

    Science.gov (United States)

    Kongsbak, Katja; Thilsted, Shakuntala H; Wahed, Mohammed A

    2008-03-01

    In Bangladesh, some commonly consumed, indigenous, freshwater small fish species (eaten whole with bone, head and eyes) such as mola (Amblypharyngodon mola) are nutrient-dense, containing preformed vitamin A as retinol and especially 3,4-dehydroretinol. The objective of the present randomised, controlled efficacy study was to evaluate the effects of mola on biochemical indicators of vitamin A status. Children (n 196), aged 3-7 years, with serum retinol 0.36-0.75 micromol/l, were randomly allocated to one of three treatment groups to receive a daily test meal (6 d/week for 9 weeks) of rice and vegetable curry (no vitamin A) ad libitum and 50 g fish curry consisting of: (1) mola, 600 retinol activity equivalents (RAE) (using 40 % biological activity of 3,4-dehydroretinol isomers) (experimental group, n 66); (2) rui (Labeo rohita), a large fish (no vitamin A), with added retinyl palmitate, 600 RAE (positive control group, n 65); or (3) rui, 0 RAE (negative control group, n 65). The nutrient compositions of the dishes were analysed. After 9 weeks, no significant treatment effects were observed for serum retinol (P = 0.52) and retinol-binding protein (P = 0.81) in the experimental group compared with the negative control, whereas the positive control improved significantly (P curry to retinol. Further research on the functional effect of mola in humans is needed. Mola is a nutrient-dense animal-source food, rich in haem Fe, Zn and especially Ca, thus consumption of mola in Bangladesh should continue to be encouraged.

  8. Disturbance cues in freshwater prey fishes: Does urea function as an‘early warning cue’in juvenile convict cichlids and rainbow trout?

    Institute of Scientific and Technical Information of China (English)

    Grant E. BROWN; Christopher D. JACKSON; Patrick H. MALKA; (E)lisa JACQUES; Marc-Andre COUTURIER

    2012-01-01

    Freshwater vertebrate and invertebrate prey species commonly rely on chemosensory information,including non-injury released disturbance cues,to assess local predation threats.We conducted laboratory studies to (1) determine if urea can function as a disturbance cue in juvenile convict cichlids and rainbow trout and (2) determine if the background level of urea influences the behavioral response to a subsequent pulse of urea ('background noise' hypothesis).In the first series of trials,juvenile cichlids and trout were exposed to urea at varying concentrations (0 to 0.5 mg L-1 for cichlids and 0 to 1.0 mg L-1 for trout).Our results suggest that both cichilds and trout exhibited functionally similar responses to urea and conspecific disturbance cues and that increasing the concentration of urea results in an increase intensity of antipredator behaviour.In the second series of trials,we pre-exposed cichlids or trout to intermediate or high concentrations of urea (or a distilled water control) and then tested for the response to a second pulse of urea at at intermediate or high concentrations (versus a distilled water control).Our results demonstrate that pre-exposure to urea reduces or eliminates the response to a second pulse of urea,supporting the background noise hypothesis.Together,our results suggest that pulses of urea,released by disturbed or stressed individuals,may function as an early warning signal in freshwater prey species [Current Zoology 58 (2):250-259,2012].

  9. 常见养殖淡水鱼肠道细菌耐药性研究%Antibiotic resistance of the intestinal flora in the domestic species of cultured freshwater fish

    Institute of Scientific and Technical Information of China (English)

    杨宇宸; 崔泽林; 郭晓奎; 刘畅

    2011-01-01

    Objective To study the different antibiotic resistance of the intestinal flora in domestic species of freshwater fish. Methods The fecal specimens were collected from two species of freshwater fish,and were cultured on agar-plate containing 7 kinds of antibiotics ( penicilin G, cefuroxime sodium, gentamicin,ciprofloxacin, tetracycline, erythromycin and SMZ) for the antibiotic susceptibility test. PCR was applied on the results to analyse the 16S rRNA gene sequences of resistant strains and identify their species. x2test was adopt in the comparison between the two fishes. Results 2956 drug-resistant isolates were screened from all of the samples. The rates of resistance to penicilin G, cefuroxime sodium, gentamicin, ciprofloxacin,tetracycline, erythromycin and SMZ were 8.89%, 1.57%, 0.08%, 0. 11%, 0. 28%, 0.07% and 0.06%,respectively. The results of identification showed that the main components of the 71 strains selected by simple random method were 31 strains of Aeromonas (43.66%), 8 strains of Acinetobacter (11.27%), 6 strains of Pseudomonas (8.45%) and 6 strains of Chryseobacterium (8.45%). There were statistically significant differences in the rates of resistance to penicilin G, cefuroxime sodium, SMZ, erythromycin and tetracycline between the two kinds of fish (x2 values were 129.06,212. 54,7. 76,8. 62 and 35.40, P<0. 05).Conclusions The rates of resistance to penicilin G, cefuroxime sodium, gentamicin, ciprofoxacin,tetracycline, erythromycin and SMZ of the intestinal flora in domestic species of freshwater fish we obtained can provide foundation for us to do some researches and pursue the changes of the antibiotic resistance rates of the intestinal flora in domestic species of freshwater fish in future.%目的 调查分析目前国内常见养殖淡水鱼类肠道菌群对不同抗生素的耐药性现状.方法 选取两种常见养殖淡水鱼类的粪便标本,分别在添加了7种抗生素[青霉素G、头孢呋辛钠、庆大霉素、环丙沙星、

  10. Evaluation of pathogenic fungi occurrence in traumatogenic structures of freshwater fish Avaliação da ocorrência de fungos patogênicos em estruturas traumatogênicas de peixes fluviais

    Directory of Open Access Journals (Sweden)

    Fabio Caetano Oliveira Leme

    2011-04-01

    Full Text Available INTRODUCTION: Fungal infections in human skin, such as sporotrichosis, can occur after fish induced trauma. This work aimed to identify fungi in freshwater fish that are pathogenic to humans. METHODS: Extraction of dental arches from Serrassalmus maculatus (piranha and Hoplias malabaricus (wolf fish, stings from Pimelodus maculatus (mandis catfish, dorsal fin rays from Plagioscion spp. (corvina and Tilapia spp., for culture in Mycosel agar. Some cultures were submitted to DNA extraction for molecular identification by sequencing ITS-5.8S rDNA. RESULTS: Cultures identified most yeast as Candida spp., while sequencing also permitted the identification of Phoma spp. and Yarrowia lipolytica. CONCLUSIONS: While the search for S. schenckii was negative, the presence of fungus of the genera Phoma and Candida revealed the pathogenic potential of this infection route. The genus Phoma is involved in certain forms of phaeohyphomycosis, a subcutaneous mycosis caused by dematiaceous fungi, with reports of infections in human organs and systems. Traumatizing structures of some freshwater fish present pathogenic fungi and this may be an important infection route that must be considered in some regions of Brazil, since there are a large number of a fisherman in constant contact with traumatogenic fish.INTRODUÇÃO: Infecções fúngicas na pele humana (como a esporotricose podem se manifestar após traumatismos por peixes. O objetivo deste trabalho é procurar fungos patogênicos para o homem em peixes fluviais. MÉTODOS: Extração de arcadas dentárias Serrassalmus maculatus (piranha e Hoplias malabaricus (traíra, ferrões de Pimelodus maculatus (mandis, raios da nadadeira dorsal de Plagioscion spp. (corvina e Tilapia spp. para a realização do cultivo em agar Mycosel. Algumas culturas foram submetidas à extração de DNA para a identificação molecular pelo seqüenciamento da região ITS-5.8S do rDNA. RESULTADOS: As culturas mostraram que a maioria das

  11. Accumulation of heavy metals and human health risk assessment via the consumption of freshwater fish Mastacembelus armatus inhabiting, thermal power plant effluent loaded canal

    OpenAIRE

    Javed, Mehjbeen; Usmani, Nazura

    2016-01-01

    Bioaccumulation of six heavy metals (Mn, Fe, Co, Ni, Cu, Zn) in the muscle of highly consumed fish species (Mastacembelus armatus) were measured using atomic absorption spectrometer. Fe (213.29 mg/kg dry weight) concentration was the most, followed by Zn (186.19 mg/kg dry weight), Ni (58.98 mg/kg dry weight), Cu (41.36 mg/kg dry weight), Co (9.06 mg/kg dry weight) and Mn (9.03 mg/kg dry weight). Estimated daily intake of heavy metals was calculated by mean fish consumption rate 19.5 × 10−3 kg...

  12. Metal accumulation and antioxidant defenses in the freshwater fish Carassius auratus in response to single and combined exposure to cadmium and hydroxylated multi-walled carbon nanotubes

    International Nuclear Information System (INIS)

    Highlights: • Cd and OH-MWCNTs have a synergistic effect on Carassius auratus. • OH-MWCNTs significantly increased Cd accumulation in liver after 12 d exposure. • Co-exposure to Cd and OH-MWCNTs evoked severe hepatic oxidative stress. - Abstract: The effects of cadmium, hydroxylated multi-walled carbon nanotubes, and their mixture on metal accumulation and antioxidant defenses were studied using the goldfish Carassius auratus as the test organism. The fish were exposed to 0.1 mg/L Cd, 0.5 mg/L OH-MWCNTs, or 0.1 mg/L Cd + 0.5 mg/L OH-MWCNTs for 3 and 12 days. Then, the Cd concentration was determined in the gill, liver and muscle. Moreover, hepatic antioxidant enzyme activity (superoxide dismutase, catalase and glutathione peroxidase), glutathione level and malondialdehyde content were also measured. A continuous accumulation of Cd was observed throughout the experimental period. Cd accumulation in tissues occurred in the following order: gill > liver > muscle at 3 days and liver > gill > muscle at 12 days. The concentrations of Cd in the livers of fish exposed to the combination of Cd + OH-MWCNTs were significantly higher than those in fish exposed to either single chemical after 12 d of exposure. Meanwhile, the mixture evoked severe oxidative stress in the exposed fish, as indicated by significant inhibition of SOD, CAT and GPx activity, a remarkable decrease in GSH level, and simultaneous elevation of MDA content. These results suggested that the effect of the combined factors on metal accumulation and oxidative stress biomarkers was more obvious than that of single factors at longer exposure durations

  13. Metal accumulation and antioxidant defenses in the freshwater fish Carassius auratus in response to single and combined exposure to cadmium and hydroxylated multi-walled carbon nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Qu, Ruijuan; Wang, Xinghao; Wang, Zunyao, E-mail: wangzun315cn@163.com; Wei, Zhongbo; Wang, Liansheng

    2014-06-30

    Highlights: • Cd and OH-MWCNTs have a synergistic effect on Carassius auratus. • OH-MWCNTs significantly increased Cd accumulation in liver after 12 d exposure. • Co-exposure to Cd and OH-MWCNTs evoked severe hepatic oxidative stress. - Abstract: The effects of cadmium, hydroxylated multi-walled carbon nanotubes, and their mixture on metal accumulation and antioxidant defenses were studied using the goldfish Carassius auratus as the test organism. The fish were exposed to 0.1 mg/L Cd, 0.5 mg/L OH-MWCNTs, or 0.1 mg/L Cd + 0.5 mg/L OH-MWCNTs for 3 and 12 days. Then, the Cd concentration was determined in the gill, liver and muscle. Moreover, hepatic antioxidant enzyme activity (superoxide dismutase, catalase and glutathione peroxidase), glutathione level and malondialdehyde content were also measured. A continuous accumulation of Cd was observed throughout the experimental period. Cd accumulation in tissues occurred in the following order: gill > liver > muscle at 3 days and liver > gill > muscle at 12 days. The concentrations of Cd in the livers of fish exposed to the combination of Cd + OH-MWCNTs were significantly higher than those in fish exposed to either single chemical after 12 d of exposure. Meanwhile, the mixture evoked severe oxidative stress in the exposed fish, as indicated by significant inhibition of SOD, CAT and GPx activity, a remarkable decrease in GSH level, and simultaneous elevation of MDA content. These results suggested that the effect of the combined factors on metal accumulation and oxidative stress biomarkers was more obvious than that of single factors at longer exposure durations.

  14. Checklist of the helminth parasites of the genus Profundulus Hubbs, 1924 (Cyprinodontiformes, Profundulidae), an endemic family of freshwater fishes in Middle-America.

    Science.gov (United States)

    Pinacho-Pinacho, Carlos Daniel; García-Varela, Martín; Hernández-Orts, Jesús S; Mendoza-Palmero, Carlos A; Sereno-Uribe, Ana L; Martínez-Ramírez, Emilio; Andrade-Gómez, Leopoldo; López-Jiménez, Alejandra; Hernández-Cruz, Eduardo; Pérez-Ponce de León, Gerardo

    2015-01-01

    From December 2012 to November 2014, 267 fish belonging to the family Profundulidae (representing nine of the 11 species of the genus Profundulus) were collected in 26 localities of Middle-America, across southern Mexico, Guatemala, and Honduras, comprising the distribution range of the genus, and analyzed for helminth parasites. Additionally, a database with all ten available published accounts of the helminth parasite fauna of this genus (the only genus within the family) was assembled. Based on both sources of information, a checklist containing all the records was compiled as a tool to address future questions in the areas of evolutionary biology, biogeography, ecology and phylogeography of this host-parasite association. The helminth parasite fauna of this fish group consists of 20 nominal species, classified in 17 genera and 14 families. It includes six species of adult digeneans, five metacercariae, two monogeneans, one adult cestode, three adult nematodes and three larval nematodes. The profundulid fishes are parasitized by a specialized group of helminth species (e.g. Paracreptotrema blancoi sensu Salgado-Maldonado et al. (2011b), Paracreptotrema profundulusi Salgado-Maldonado, Caspeta-Mandujano & Martínez Ramírez, 2011, Phyllodistomum spinopapillatum Pérez-Ponce de León, Pinacho-Pinacho, Mendoza-Garfias & García-Varela, 2015, Spinitectus humbertoi Mandujano-Caspeta & Moravec, 2000, Spinitectus mariaisabelae Caspeta-Mandujano Cabañas-Carranza & Salgado-Maldonado, 2007 and Rhabdochona salgadoi Mandujano-Caspeta & Moravec, 2000), representing the core helminth fauna that are not shared with other Middle-American fish species. PMID:26478697

  15. Epidemiological Study on Frequency of Myxosporidian Diseases in Freshwater Fish Stemming from Aquatic Habitats Pertaining to the Danubian Delta Biosphere Reservation

    OpenAIRE

    Laura Daniela Urdeş; Cristiana Diaconescu; Marius Hangan; Marin Monica; Ştefan Diaconescu

    2010-01-01

    order to measure their frequencies and distributions within populations of Esox lucius, Sander lucioperca(Henneguyosis) and Perca fluviatilis (Myxoboliosis) originating from Sontea-Fortuna (S.F.) and Gorgova-Uzlina(G.U.) aquatic habitats, within the Biosphere Reservation of Danubian Delta, Romania.The biologic material was selected without prior knowledge of the disease status. Prevalence was determined byclassifying fishes as either diseased/infected or not, at one moment in time (Point prev...

  16. Effect of oven drying and freeze drying on the antioxidant and functional properties of protein hydrolysates derived from freshwater fish (Cirrhinus mrigala) using papain enzyme.

    Science.gov (United States)

    Elavarasan, Krishnamoorthy; Shamasundar, Bangalore Aswathnarayan

    2016-02-01

    Fish protein hydrolysate (FPH) was prepared from fresh water fish Cirrhinus mrigala using papain and dried in oven (OD-FPH) and freeze dryer (FD-FPH). The electron micrographs of FD-FPH samples showed porous structure. The browning intensity of OD-FPH samples was higher than the FD-FPH samples. The DPPH (2, 2 Diphenyl-1-picrylhydrazyl) free radical scavenging activity and linoleic acid peroxidation inhibition activity of FPH were not affected by oven drying process. The sequential digestion of FPH with pepsin and pancreatin reduced the antioxidant properties in both OD-FPH and FD-FPH samples. The solubility of proteins in OD-FPH was lower at pH 5 while for that of FD-FPH it was at pH 7 with water as solvent. The surface active properties of FD-FPH samples were higher than OD-FPH samples. The oven drying of fish protein hydrolysates may be advocated considering the properties and cost of production. PMID:27162411

  17. Fatty Acid Composition and Levels of Selected Polyunsaturated Fatty Acids in Four Commercial Important Freshwater Fish Species from Lake Victoria, Tanzania

    Directory of Open Access Journals (Sweden)

    Agnes Robert

    2014-01-01

    Full Text Available Fatty acids (FAs particularly ω3 and ω6 polyunsaturated fatty acids (PUFAs play important role in human health. This study aimed to investigate the composition and levels of selected ω3 PUFAs in four commercial fish species, Nile perch (Lates niloticus, Nile tilapia (Oreochromis niloticus, Tilapia zillii, and dagaa (Rastrineobola argentea from Mwanza Gulf in Lake Victoria. The results indicated that 36 types of FAs with different saturation levels were detected. These FAs were dominated by docosahexaenoic (DHA, eicosapentaenoic (EPA, docosapentaenoic (DPA, and eicosatetraenoic acids. O. niloticus had the highest composition of FAs (34 compared to L. niloticus (27, T. zillii (26, and R. argentea (21. The levels of EPA differed significantly among the four commercial fish species (F=6.19,  P=0.001. The highest EPA levels were found in R. argentea followed by L. niloticus and O. niloticus and the lowest in T. zillii. The DPA levels showed no significant difference among the four fish species studied (F=0.652,  P=0.583. The study concluded that all four commercial species collected from Mwanza Gulf are good for human health, but R. argentea is the best for consumption because it contains higher levels of ω3 FAs, mainly EPA.

  18. Leap of faith: voluntary emersion behaviour and physiological adaptations to aerial exposure in a non-aestivating freshwater fish in response to aquatic hypoxia.

    Science.gov (United States)

    Urbina, Mauricio A; Forster, Malcolm E; Glover, Chris N

    2011-05-01

    Lowland stream fauna in areas of intensive agriculture are increasingly under threat from anthropogenic activities leading to eutrophication and subsequent hypoxia. Survival of hypoxic episodes depends upon a combination of behavioural and physiological adaptations. Responses of inanga (Galaxias maculatus: Galaxiidae) to aquatic hypoxia were investigated in the laboratory. Contrary to expectation inanga did not display behaviour that might reduce energy expenditure during oxygen limitation, with swimming activity slightly, but significantly elevated relative to normoxia. Instead, as dissolved oxygen concentrations decreased, the fish moved higher in the water column, increased their swimming speed and exhibited aquatic surface respiration. Physiological changes such as enhanced opercular frequency were also noted. As hypoxia deepened inanga started to leap out of the water, emersing themselves on a floating platform. Once emersed, fish exhibited an enhanced oxygen consumption rate compared to hypoxic fish. Thus inanga appear better adapted to escape hypoxia (a behavioural adaptation) rather than tolerate it (physiological adaptation). The emersion strategy used for inanga in response to severe hypoxia is in agreement with their ability to take up more oxygen from the air than from hypoxic water and therefore may justify the potentially increased risks of desiccation and predation associated with leaving the water. PMID:21316378

  19. Cenozoic tectonic and climatic events in southern Iberian Peninsula: Implications for the evolutionary history of freshwater fish of the genus Squalius (Actinopterygii, Cyprinidae).

    Science.gov (United States)

    Perea, Silvia; Cobo-Simon, Marta; Doadrio, Ignacio

    2016-04-01

    Southern Iberian freshwater ecosystems located at the border between the European and African plates represent a tectonically complex region spanning several geological ages, from the uplifting of the Betic Mountains in the Serravalian-Tortonian periods to the present. This area has also been subjected to the influence of changing climate conditions since the Middle-Upper Pliocene when seasonal weather patterns were established. Consequently, the ichthyofauna of southern Iberia is an interesting model system for analyzing the influence of Cenozoic tectonic and climatic events on its evolutionary history. The cyprinids Squalius malacitanus and Squalius pyrenaicus are allopatrically distributed in southern Iberia and their evolutionary history may have been defined by Cenozoic tectonic and climatic events. We analyzed MT-CYB (510 specimens) and RAG1 (140 specimens) genes of both species to reconstruct phylogenetic relationships and to estimate divergence times and ancestral distribution ranges of the species and their populations. We also assessed their levels of genetic structure and diversity as well as the amount of gene flow between populations. To investigate recent paleogeographical and climatic factors in southern Iberia, we modeled changes-through-time in sea level from the LGM to the present. Phylogenetic, geographic and population structure analyses revealed two well-supported species (S. malacitanus and S. pyrenaicus) in southern Iberia and two subclades (Atlantic and Mediterranean) within S. malacitanus. The origin of S. malacitanus and the separation of its Atlantic and Mediterranean populations occurred during the Serravalian-Tortonian and Miocene-Pliocene periods, respectively. These divergence events occurred in the Middle Pliocene and Pleistocene in S. pyrenaicus. In both species, Atlantic basins possessed populations with higher genetic diversity than Mediterranean, which may be explained by the Janda Lagoon. The isolation of S. malacitanus was

  20. 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

  1. Critical thermal maxima and minima of the platyfish Xiphophorus maculatus Günther (Poecillidae, Cyprinodontiformes: a tropical species of ornamental freshwater fish

    Directory of Open Access Journals (Sweden)

    Viviane Prodocimo

    2001-07-01

    Full Text Available Temperature as an environmental factor has been a frequent subject of study, since it affects either directly or indirectly all living organisms. The determination of thermal limits (critical thermal minima - CTmin and maxima - CTmax for the tropical ornamental freshwater teleost Xiphophorus maculatus Günther, 1866 (platyfish was performed after their acclimation to the following temperatures: 15, 20, 25, and 30ºC, for seven days. After this period, the water temperature was elevated or reduced at a rate of 0.125ºC/min until CTmax and CTmin could be determined as the temperature at which 50% of the animals had lost equilibrium. Mean values for CTmax and CTmin for the acclimation temperatures of 15, 20, 25, and 30ºC were respectively: 39.8,39.8,40.4,41.5ºC (CTmax, and 9.6, 12.8, 13.1, 16.0ºC (CTmin. CTmax and CTmin for X. maculatus were thus affected by acclimation temperature. This tropical species is more heat- than cold- tolerant and would not resist the typical low winter temperatures of southern Brazil. Platyfish can adapt to natural environments in regions of mean annual temperatures around 20-25ºC or be kept in aquaria with other ornamental species that accordingly prefer this temperature range.

  2. The 5S rDNA family evolves through concerted and birth-and-death evolution in fish genomes: an example from freshwater stingrays

    Directory of Open Access Journals (Sweden)

    Araki Carlos S

    2011-05-01

    Full Text Available Abstract Background Ribosomal 5S genes are well known for the critical role they play in ribosome folding and functionality. These genes are thought to evolve in a concerted fashion, with high rates of homogenization of gene copies. However, the majority of previous analyses regarding the evolutionary process of rDNA repeats were conducted in invertebrates and plants. Studies have also been conducted on vertebrates, but these analyses were usually restricted to the 18S, 5.8S and 28S rRNA genes. The recent identification of divergent 5S rRNA gene paralogs in the genomes of elasmobranches and teleost fishes indicate that the eukaryotic 5S rRNA gene family has a more complex genomic organization than previously thought. The availability of new sequence data from lower vertebrates such as teleosts and elasmobranches enables an enhanced evolutionary characterization of 5S rDNA among vertebrates. Results We identified two variant classes of 5S rDNA sequences in the genomes of Potamotrygonidae stingrays, similar to the genomes of other vertebrates. One class of 5S rRNA genes was shared only by elasmobranches. A broad comparative survey among 100 vertebrate species suggests that the 5S rRNA gene variants in fishes originated from rounds of genome duplication. These variants were then maintained or eliminated by birth-and-death mechanisms, under intense purifying selection. Clustered multiple copies of 5S rDNA variants could have arisen due to unequal crossing over mechanisms. Simultaneously, the distinct genome clusters were independently homogenized, resulting in the maintenance of clusters of highly similar repeats through concerted evolution. Conclusions We believe that 5S rDNA molecular evolution in fish genomes is driven by a mixed mechanism that integrates birth-and-death and concerted evolution.

  3. CROATIAN FRESHWATER FISHERIES IN 1995

    Directory of Open Access Journals (Sweden)

    Mirko Turk

    1996-06-01

    Full Text Available The data on the production and catch of fish according to sorts, pond ackerage, fishing means as well as the distribution of production and catch in 1995 have been stated in the paper. Ackerages used for the fish production have been increased by 1710 acres or 6.51%; total fish prinos* is less for 1,252 tons or 17.05%. The highest production of fish was reched by the fish farm Donji Miholjac with 859 kg/ha. A nutritive coefficient is 3.0 kg and it is less by 3.22% compared with the previous year. The nutritive coefficient is less than 2.0 kg in three fish-farms but it is greater than 4.0 kg in five large fish farms. Mostly corn but also wheat dominate in fish nutrition. The fertilizers consumption has been reduced by 14.53%. Of total pond ackerage, growing fish farms occupy 1.25%, new fish farms occupy 17.90% and consumptive fish farms occupy 79.64%. Total fish production in carp ponds is 507 kg/ha and 136.1 ton/ha in trout ponds. With 84.33%, carp is the mostly produced fish sorts, herbivore fish follow it with 3.89% and the production of all other fish makes 11.78% of the total. With 83.97%, grass carp takes the first place in the structure of herbivore fish. It is followed by the big head carp with 9.28% and silver carp with 6.75%. The trout production has been slightly increased by 6. 3%. Pike has appeared again and all other fish sorts has been reduced. Fish catch in open water has been increased by 7.06% compared with the previous year. When we sum up total production and catch of fresh-water fish, we can conclude that carp contributes with 81.08%; herbivore fish with 3.67%; trouts with 5.53%; sheat-fish, pike-perch and pike with 2.74% and all other fish sorts with 6.98%. As to the distribution of production and catch, there has been 49.02% sold on markets, 38.02% has been spent on farm reproduction (set back in ponds, the percentage of mortalities is 7.90%. Sport fishers have spent 5.06% of fish. The number of employees has been reduced

  4. Correlation Among the Contents in Five Kinds of Freshwater Fish, Fish Intake, Mercury in Cord Blood and in Fetal Hair in Wujiang%吴江地区5种淡水鱼含汞量测定及食鱼与脐血汞、胎发汞的相关性

    Institute of Scientific and Technical Information of China (English)

    刘永琴; 吕弘道; 郭俊良; 陈梅竹; 苏海兰

    2011-01-01

    目的 测定吴江地区经常食用的5种淡水鱼含汞量,分析孕期食鱼频率与脐血汞和胎发汞的相关性,从而对孕期控制鱼类摄入量提出相应建议.方法 一年中分四个季度对鳊鱼、鲫鱼、鲢鱼、鲈鱼和黑鱼这5种淡水鱼的背部肌肉和近腹鳍脂肪组织进行含汞量测定,对同期入院分娩的产妇进行食鱼频率问卷调查,所分娩新生儿进行脐血汞和胎发汞测定.结果 5种淡水鱼背部肌肉含汞量(ng/g)依次为8.71±1.92、17.83±1.73、26.14±1.49、31.83 +2.03、35.18±1.75,鳊鱼<鲫鱼<鲢鱼<鲈鱼<黑鱼,差异有高度统计学意义(均P<0.01);腹脂肪含汞量由小到大依次为18.21±1.61(鲫鱼)、19.09±3.14(鳊鱼)、30.67±1.70(黑鱼)、30.83±1.48(鲈鱼)、48.86±2.06(鲢鱼),差异有高度统计学意义(均P<0.01).鳊鱼、鲢鱼腹脂肪含汞量明显高于背肌肉(均P<0.05).孕期每周食淡水鱼或海鱼3次以上者脐血汞、胎发汞含量明显高于每周食鱼1~2次者(P<0.05).结论 吴江地区5种淡水鱼组织含汞量低于中国国家食品鱼类卫生标准,但因甲基汞影响胎儿神经系统发育,对于特殊敏感人群的孕期妇女,建议每周食鱼频率不宜超过2次,且应选择食用组织含汞量少的鱼类,避免食用腹部富含脂肪的组织.%Objective To research the mercury contents of five kinds of freshwater fish in Wujiang and to analyze the correlation among the frequency of fish intake during pregnancy and mercury in cord blood and mercury in fetal hair, and to make appropriate recommendations for controlling fish intake during pregnancy. Methods The mercury contents were determined in the muscles of back and fatty tissue near ventral fin from five kinds of freshwater fish in Wujiang I. E. Bream, crucian carp, silver carp, perch and blackfish in every quarter. At the same time, puerperants in hospital were investigated on the intake frequency of fish by using questionaries, and

  5. Freshwater mussels of the Noxubee National Wildlife Refuge

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This is a summary of the freshwater mussels on Noxubee National Wildlife Refuge. The species listed and assoicated informaiton is based on existing literature. The...

  6. Caernarvon freshwater diversion: Contaminants monitoring study (interim report)

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The Caernarvon Freshwater Diversion Structure was completed in January 1991 by the U.S. Army Corps of Engineers. The purpose of the structure is to divert...

  7. Freshwater mussels of North Mississippi National Wildlife Refuge Complex

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — A literature search of the distribution of freshwater mussels anticipated to be found on refuges assoicated with the North Mississippi Refuges Cjomplex and museum...

  8. Distributions and phylogeographic data of rheophilic freshwater fishes provide evidences on the geographic extension of a central-brazilian amazonian palaeoplateau in the area of the present day Pantanal Wetland

    Directory of Open Access Journals (Sweden)

    Alexandre C. Ribeiro

    2013-06-01

    Full Text Available The analysis of the distribution patterns presented by examples of freshwater fishes restricted to headwater habitat: the anostomid Leporinus octomaculatus, the characins Jubiaba acanthogaster, Oligosarcus perdido, Moenkhausia cosmops, Knodus chapadae, Planaltina sp., the loricariid Hypostomus cochliodon, and the auchenipterid Centromochlus sp. provided evidences of a relatively recent shared history between the highlands of the upper rio Paraguay and adjoining upland drainage basins. Restricted to headwater of the uplands in the upper rio Paraguay and adjoining basins, these species provide biological evidence of the former extension of the central Brazilian plateau before the origin of the Pantanal Wetland. Disjunction took place due to an ecological barrier to these rheophilic taxa represented tectonic subsidence related to the origin of the Pantanal Wetland. Molecular analysis of Jubiaba acanthogaster revealed that the sample from the upper rio Xingu basin are the sister-group of a clade that includes samples from the upper rio Arinos (upper rio Tapajós plus the upper rio Paraguay basin, supporting the assumption that the origin of the upper rio Paraguay basin causing vicariance between this basin and the upper rio Tapajós is the least vicariant event in the evolutionary history of the group.

  9. Scanning electron microscope observations on the monogenean parasite Paraquadriacanthus nasalis from the nasal cavities of the freshwater fish Clarias gariepinus in Egypt with a note on some surface features of its microhabitat.

    Science.gov (United States)

    Arafa, Safaa Zaky

    2012-05-01

    Surface features of the monogenean Paraquadriacanthus nasalis Ergens, 1988 (quoted by Kritsky, 1990) inhabiting the nasal cavities of the freshwater fish Clarias gariepinus were studied for the first time using scanning electron microscopy. The anterior adhesive areas possess two slit-like openings. Many small openings were detected on the tegument covering the anterior-most region of the head. Some considerably large openings were also found in the median region between the two slit-like openings of the adhesive sacs. A transverse slit-like mouth opening with two lip-like structures was detected on the ventral surface of the body. Three types of presumed sensory structures were found associated with the tegument of the anterior adhesive area and anterior region of the body. These are surface ciliary sensilla, dome-shaped structures, and many spherical structures. The possible functions of these presumed sensory structures were discussed. The tegument covering the anterior adhesive area lacks microvilli, while the tegument covering the haptor is associated with microvilli. The haptoral sclerites were found in two different positions. Some surface features of the nasal cavities of C. gariepinus (microhabitat of P. nasalis) were also studied using scanning electron microscopy. Many lamellae-like and spine-like structures were recognized. The epithelium lining in some regions of the nasal cavities has small and large openings and covered with mucus. The possible roles of some haptoral sclerites in the attachment of the parasite to the host tissues were discussed. PMID:22015385

  10. Davis Pond Freshwater Prediversion Biomonitoring Study: Freshwater Fisheries and Eagles

    Science.gov (United States)

    Jenkins, Jill A.; Bourgeois, E. Beth; Jeske, Clint W.

    2008-01-01

    In January 2001, the construction of the Davis Pond freshwater diversion structure was completed by the U.S. Army Corps of Engineers. The diversion of freshwater from the Mississippi River is intended to mitigate saltwater intrusion from the Gulf of Mexico and to lessen the concomitant loss of wetland areas. In addition to the freshwater inflow, Barataria Bay basin would receive nutrients, increased flows of sediments, and water-borne and sediment-bound compounds. The purpose of this biomonitoring study was, therefore, to serve as a baseline for prediversion concentrations of selected contaminants in bald eagle (Haliaeetus leucocephalus) nestlings (hereafter referred to as eaglets), representative freshwater fish, and bivalves. Samples were collected from January through June 2001. Two similarly designed postdiversion studies, as described in the biological monitoring program, are planned. Active bald eagle nests targeted for sampling eaglet blood (n = 6) were generally located southwest and south of the diversion structure. The designated sites for aquatic animal sampling were at Lake Salvador, at Lake Cataouatche, at Bayou Couba, and along the Mississippi River. Aquatic animals representative of eagle prey were collected. Fish were from three different trophic levels and have varying feeding strategies and life histories. These included herbivorous striped mullet (Mugil cephalus), omnivorous blue catfish (Ictalurus furcatus), and carnivorous largemouth bass (Micropterus salmoides). Three individuals per species were collected at each of the four sampling sites. Freshwater Atlantic rangia clams (Rangia cuneata) were collected at the downstream marsh sites, and zebra mussels (Dreissena spp.) were collected on the Mississippi River. The U.S. Geological Survey (USGS) Biomonitoring of Environmental Status and Trends (BEST) protocols served as guides for fish sampling and health assessments. Fish are useful for monitoring aquatic ecosystems because they accumulate

  11. Níveis de mercúrio total em peixes de água doce de pisciculturas paulistas Mercury levels in freshwater fishes from piscicultures estabilished in São Paulo State

    Directory of Open Access Journals (Sweden)

    Marcelo A. Morgano

    2005-06-01

    Full Text Available Avaliou-se os níveis de mercúrio total em amostras de peixes de água doce, procedentes de pesqueiros e pisciculturas de 39 regiões do estado de São Paulo. As espécies de peixes estudadas foram: pacu (Piaractus mesopotamicus, tilápia (Oreochromis niloticus, piauçu (Leoporinum sp, matrinxã (Brycon cephalus, tambaqui (Colossoma macropomum e carpa (Cyprinus carpis. Foram avaliadas três metodologias de digestão de amostras para a determinação de mercúrio total, variando-se o volume de mistura sulfonítrica utilizada e a concentração do permanganato de potássio, sendo que o uso de 10mL de mistura sulfonítrica e solução de permanganato de potássio a 7% (m/v na digestão da amostra foi a que forneceu as recuperações mais altas (96%, precisão de 1% e limite de quantificação de 0,3µg/kg. Após a validação do método, foram realizadas as determinações de teor de mercúrio total em 293 amostras de pescado, usando a técnica de espectrometria de emissão com fonte de plasma acoplado em gerador de hidretos. Os níveis médios de mercúrio encontrados variaram entre: tambaqui (0,0003-0,012mg/kg, carpa (0,063mg/kg, matrinxã (0,0003-0,074mg/kg, pacu (0,0003-0,078mg/kg, piauçu (0,0003-0,183mg/kg e tilápia (0,0003-0,217mg/kg. Os resultados mostraram que nenhuma das amostras procedentes das diferentes regiões e diferentes pesque-pagues, apresentaram níveis de mercúrio total acima do permitido pela legislação brasileira, que é de 0,5mg/kg para pescado não-predador.In this work, the levels of mercury were evaluated in samples of freshwater fish, coming from fishing-grounds and piscicultures of 39 regions of São Paulo State. The species of fish studied were: pacu (Piaractus mesopotamicus, tilápia (Oreochromis niloticus, piauçu (Leoporinum sp, matrinxã (Brycon cephalus, tambaqui (Colossoma macropomum and carpa (Cyprinus carpis. Three digestion methodologies of sample were evaluated for the mercury determination, with

  12. Effect of Yerbimat herbicide on lipid peroxidation, catalase activity, and histological damage in gills and liver of the freshwater fish Goodea atripinnis.

    Science.gov (United States)

    Ortiz-Ordoñez, Esperanza; Uría-Galicia, Esther; Ruiz-Picos, Ricardo Arturo; Duran, Angela Georgina Sánchez; Trejo, Yoseline Hernández; Sedeño-Díaz, Jacinto Elías; López-López, Eugenia

    2011-10-01

    The use of herbicides for agricultural and aquatic weed control has increased worldwide. These substances are potentially toxic pollutants because they induce the production of reactive oxygen species for biological systems and exert oxidative stress in nontarget organisms living in the treated aquatic systems. Recent evidence suggests differences in the toxicity of glyphosate in the form of an active ingredient compared to the toxicity of glyphosate in combination with surfactants, such as those found in commercial formulations. In Mexico, one of the most widely used glyphosate-based herbicides is Yerbimat, which has agricultural as well as aquatic weed control applications. However, there are no aquatic toxicity data, particularly regarding native fish. Therefore, we determined the acute toxicity of commercial-formulation Yerbimat in a static bioassay at 96 h (LC(50)). We also determined its toxicity at 96 h in sublethal concentrations to assess the lipid peroxidation levels (LPX), catalase activity, hepatic glycogen content, and histological damage in the liver and gills of the fish Goodea atripinnis associated with chronic exposure (75 days). The LC(50) was 38.95 ± 0.33 mg/L. The results of the short-term exposure study indicate that Yerbimat can potentially induce oxidative stress in G. atripinnis, because LPX was increased in the gills and liver. Catalase activity was reduced in the gills but increased in the liver, whereas hepatic glycogen was depleted. Chronic exposure was associated with histopathological damage in the gills and liver, some of which was irreversible. Yerbimat represents a potential risk for aquatic biota; therefore, we recommend that its application be carefully considered.

  13. Comparative antioxidant status in freshwater fish Carassius auratus exposed to six current-use brominated flame retardants: A combined experimental and theoretical study

    Energy Technology Data Exchange (ETDEWEB)

    Feng, Mingbao; Qu, Ruijuan; Wang, Chao; Wang, Liansheng; Wang, Zunyao, E-mail: wangzun315cn@163.com

    2013-09-15

    Highlights: •A combined experimental and theoretical approach was used for risk assessments of six BFRs in fish. •Oxidative stress biomarkers were measured for toxicity identification. •Toxicity order was proposed via the integrated biomarker response. •Theoretical calculations were performed to analyze the BFRs toxicity. -- Abstract: Decabromodiphenyl ether (BDE-209) and several non-polybrominated diphenyl ether (PBDE) brominated flame retardants (BFRs), such as tetrabromobisphenol A (TBBPA), hexabromocyclododecane (HBCD), decabromodiphenyl ethane (DBDPE), hexabromobenzene (HBB) and pentabromotoluene (PBT), are persistent halogenated contaminants ubiquitously detected in aquatic systems. However, data on comparative toxicological effects of these BFRs are lacking for fish. In this study, a combined experimental and theoretical approach was used to compare and analyze the effects of these BFRs on biochemical biomarkers in liver of Carassius auratus injected intraperitoneally with different doses (10 and 100 mg/kg) for 7, 14 and 30 days. Oxidative stress was evoked evidently for the prolonged exposure, represented by the significantly altered indices (superoxide dismutase, catalase, glutathione peroxidase, reduced glutathione, and malondialdehyde). The integrated biomarker response (IBR) index ranked biotoxicity as: PBT > HBB > HBCD > TBBPA > BDE-209 > DBDPE. Quantum chemical calculations (electronic parameters, frontier molecular orbitals, and Wiberg bond order) were performed for theoretical analysis. Notably, some descriptors were correlated with the toxicity order, probably implying the existence of a potential structure–activity relationship when more BFRs were included. Besides, theoretical calculations also provided some valuable information regarding the molecular characteristics and metabolic pathways of these current-use BFRs, which may facilitate the understanding on their environmental behavior and fate. Overall, this study adopted a combined

  14. Growth of fresh-water prawn Macrobrachium tenellum (Smith, 1871 juveniles fed isoproteic diets substituting fish meal by soya bean meal

    Directory of Open Access Journals (Sweden)

    Manuel García-Ulloa Gomez

    2008-02-01

    Full Text Available Growth parameters (standard length, weight, specific growth rate and daily weight gain of prawn Macrobrachium tenellum juveniles fed 40% crude protein isoproteic diets substituting fish meal with soya bean meal at various levels (20, 40, 60, 80 and 100% were evaluated for 45 days under laboratory conditions. Experimental diets were compared with a 100% fish meal based diet. Total survival was recorded for all the treatments at the end of the experiment. There were no significant differences (p > 0.05 for all the growth parameters among the dietary treatments. The initial mean weight (0.36 ± 0.10 g increased almost three times (1.00 ± 0.13 g after 45 days. The final specific growth fluctuated from 1.82% BW/d for the 60% soya bean meal inclusion diet, to 2.62% for the 100% fish meal diet. The mean final survival was 91.66%. Growth performance of M. tenellum juveniles was not affected by the dietary soya bean meal levels tested.Os parâmetros do crescimento (comprimento padrão, peso, taxa de crescimento específica e ganho diário do peso de juveniles do Macrobrachium tenellum alimentaram a 40% a proteína crua as dietas isoproteic que substituem a refeição de peixes com feijão de soya a refeição nos vários níveis (20, 40, 60, 80 e 100% foi avaliada por 45 dias sob condições do laboratório. As dietas experimentais foram comparadas com uma dieta baseada da refeição de peixes de 100%. A sobrevivência total foi gravada para todos os tratamentos no fim da experiência. Não havia nenhuma diferença significativa (p > 0.05 para todos os parâmetros do crescimento entre os tratamentos dietéticos. O peso médio inicial (0.36 ± 0.10 g aumentado quase três vezes (1.00 ± 0.13 g após 45 dias da cultura. O crescimento específico final flutuou de 1.82% BW/d para a dieta do inclusion da refeição do feijão de soya de 60%, a 2.62% obtidos para a dieta da refeição de peixes de 100%. A sobrevivência final média foi de 91.66%. O

  15. Fish based diets cause archaeological dating problems

    DEFF Research Database (Denmark)

    Philippsen, Bente; Rørbæk, Rasmus

    2013-01-01

    Every time our ancestors cooked freshwater fish in ceramic vessels, they unwittingly set a Carbon-14 trap for future archaeologists......Every time our ancestors cooked freshwater fish in ceramic vessels, they unwittingly set a Carbon-14 trap for future archaeologists...

  16. Coastal Resources Atlas: Long Island: FISH (Fish Polygons)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for marine, estuarine, anadromous, and freshwater fish species for Long Island, New York. Vector polygons...

  17. Cytotoxicity, genotoxicity and oxidative stress of malachite green on the kidney and gill cell lines of freshwater air breathing fish Channa striata.

    Science.gov (United States)

    Majeed, S Abdul; Nambi, K S N; Taju, G; Vimal, S; Venkatesan, C; Hameed, A S Sahul

    2014-12-01

    The cytotoxicity, genotoxicity and oxidative stress of malachite green (MG) was investigated using the fish Channa striata kidney (CSK) and Channa striata gill (CSG) cell lines. Five concentrations ranging from 0.001 to 10 μg mL(-1) were tested in three independent experiments. Cytotoxicity was assessed by 3-(4, 5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, Rhodamine 123 and Alamar Blue. The mitochondrial changes and apoptosis of MG-exposed cells were observed by Rhodamine 123 and acridine orange/ethidium bromide (AO/EB) staining, respectively. In vitro potential DNA damaging effect of MG was tested using comet assay. Mitochondrial damage, apoptosis and DNA fragmentation increased in a concentration-dependent manner. Additionally, DNA electrophoretic mobility experiments were carried out to study the binding effect of MG to double-stranded DNA (dsDNA) of cells. DNA shift mobility experiments showed that MG is capable of strongly binding to linear dsDNA causing its degradation. Biochemical parameters such as lipid peroxidation (MDA), catalase (CAT) activity and reduced glutathione (GSH) levels were evaluated after exposure to MG. In CSK and CSG cell lines exposed to MG for 48 h, a significant increase in lipid peroxidation, which might be associated with decreased levels of reduced glutathione and catalase activity in these cell lines (p < 0.001), was observed. PMID:25023653

  18. Metal accumulation and oxidative stress biomarkers in liver of freshwater fish Carassius auratus following in vivo exposure to waterborne zinc under different pH values.

    Science.gov (United States)

    Qu, Ruijuan; Feng, Mingbao; Wang, Xinghao; Qin, Li; Wang, Chao; Wang, Zunyao; Wang, Liansheng

    2014-05-01

    In this study, laboratory experiments were conducted to investigate the combined effect of zinc and pH on metal accumulation and oxidative stress biomarkers in Carassius auratus. Fish were exposed to 0.1 and 1.0mg Zn/L at three pH values (5.0, 7.25, 9.0) for 3, 12, and 30 d. After each exposure, the contents of three trace elements (Zn, Fe and Cu) were determined in liver. Generally, longer exposure to zinc (12d and 30 d) increased hepatic Zn and Cu deposition, but decreased Fe content. Increasing accumulation of Zn in the tissue was also observed with increasing zinc concentration in the exposure medium. Moreover, hepatic antioxidant enzyme activities including superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx), together with the level of glutathione (GSH) were measured to evaluate the oxidative stress status. The decreases in the four measured biochemical parameters after 3d exposure might reflect the failure of the antioxidant defense system in neutralizing the ROS generated during the metabolic process, while the recovery of the antioxidants at days 12 and 30 suggested a possible shift toward a detoxification mechanism. With regard to the influence of pH on zinc toxicity, the general observation was that the living environment became more stressful when the water conditions changed from an acidic state toward a near-neutral or alkaline state.

  19. Challenges of Freshwater Fisheries in Nepal: A Short Overview

    Directory of Open Access Journals (Sweden)

    Nawaraj Gautam

    2015-12-01

    Full Text Available Abundant freshwater resources originated from Himalayas and high geographical variations in Nepal are two factors which might be positive benefits to improve the aquaculture in land locked country. Low labor cost is also another plus point to get better management in fisheries sector. Freshwater fisheries in Nepal are mostly dominated by catch up fisheries of indigenous fish species available in rivers, lakes and paddy fields but exotic and sophisticated species been also introduced in small scales. Beside these, poly cultural pond fish farming is most viable. Carp fishes are the major species and uncontrolled unmanaged capture fisheries dominants over systematic aquaculture. Poor technological implementations, poor budgetary plan, not proper management strategies, lack of quality fish feed and fingerlins, lower market availability are some of the major challenges of Nepalese freshwater fisheries. Long-term sustainable plan, scientific and technological study on indigenous fish species, proper hygiene management and better disease control might improve the current aquaculture status of Nepal.

  20. Metapopulations in temporary streams - the role of drought-flood cycles in promoting high genetic diversity in a critically endangered freshwater fish and its consequences for the future.

    Science.gov (United States)

    Sousa-Santos, Carla; Robalo, Joana I; Francisco, Sara M; Carrapato, Carlos; Cardoso, Ana Cristina; Doadrio, Ignacio

    2014-11-01

    Genetic factors have direct and indirect impacts in the viability of endangered species. Assessing their genetic diversity levels and population structure is thus fundamental for conservation and management. In this paper we use mitochondrial and nuclear markers to address phylogeographic and demographic data on the critically endangered Anaecypris hispanica, using a broad sampling set which covered its known distribution area in the Iberian Peninsula. Our results showed that the populations of A. hispanica are strongly differentiated (high and significant ФST and FST values, corroborated by the results from AMOVA and SAMOVA) and genetically diversified. We suggest that the restricted gene flow between populations may have been potentiated by ecological, hydrological and anthropogenic causes. Bayesian skyline plots revealed a signal for expansion for all populations (tMRCA between 68kya and 1.33Mya) and a genetic diversity latitudinal gradient was detected between the populations from the Upper (more diversified) and the Lower (less diversified) Guadiana river basin. We postulate a Pleistocenic westwards colonization route for A. hispanica in the Guadiana river basin, which is in agreement with the tempo and mode of paleoevolution of this drainage. The colonization of River Guadalquivir around 60kya with migrants from the Upper Guadiana, most likely by stream capture, is also suggested. This study highlights the view that critically endangered species facing range retreats (about 47% of its known populations have disappeared in the last 15years) are not necessarily small and genetically depleted. However, the extinction risk is not negligible since A. hispanica faces the combined effect of several deterministic and stochastic negative factors and, moreover, recolonization events after localized extinctions are very unlikely to occur due to the strong isolation of populations and to the patchily ecologically-conditioned distribution of fish. The inferred species

  1. Kefir在低值淡水鱼鱼糜脱腥中的应用%Deodorization of Freshwater Fish Surimi by Kefir

    Institute of Scientific and Technical Information of China (English)

    高翔; 王蕊

    2011-01-01

    Kefir is a fermentation starter composed of Lactobacillus,Saccharomycetes,acetic acid bacteria and other microorganisms.Its fermentation products such as acids and alcohols can function to increase aroma and remove unpleasant odor.In the present study,the application of kefir to deodorize silver carp surimi was optimized using one-factor-at-a-time combined with orthogonal array design method based on gel strength of fish surimi and sensory score for fishy smell.The optimal conditions for deodorizing silver carp surimi by kefir were achieved by 60 min culture of kefir inoculated at a level of 2.0 g/100 mL at 26 ℃.Under the optimal deodorization conditions,the fishy smell value of silver carp surimi was 1.1 with a very light fishy smell.In addition,the gel strength and whiteness were 316.45 g·cm and 62.65,respectively,similar to 317.46 g·cm and 61.85 of the control.Therefore,it is feasible to deodorize silver carp surimi by kefir fermentation.%Kefir是由乳酸菌、酵母菌及醋酸菌等多种微生物组成的发酵剂,发酵产物酸、醇均有去腥增香作用。利用Kefir发酵对淡水鱼鱼糜去腥。结果表明:Kefir添加量2.0g/100mL、脱腥温度26℃、脱腥时间60min的条件下,鲢鱼鱼糜的腥味值为1.1,鱼腥味极弱,而凝胶强度为316.45g.cm、白度62.65,与对照组(凝胶强度和白度分别为317.46g.cm和61.85)相似,因此,利用Kefir进行淡水鱼鱼糜脱腥是可行的。

  2. Incidence of the leech Actinobdella pediculata on freshwater drum in Lake Erie

    Science.gov (United States)

    Bur, Michael T.

    1994-01-01

    Actinobdella pediculata (Glossiphoniidae), a freshwater leech, was found attached to freshwater drum (Aplodinotus grunniens) from western Lake Erie during 1991 through 1993. The animal was first observed during routine examinations of freshwater drum collected in May 1991. The leeches were usually attached to the inside, lower portion of the opercula near the isthmus. Incidence of attachment increased with freshwater drum age and length. No noticeable adverse effects on the fish from attachment by the leech were noted.

  3. Cloud point extraction and flame atomic absorption spectrometric determination of trace lead in freshwater fish%浊点萃取-火焰原子吸收光谱法测定淡水鱼中痕量铅

    Institute of Scientific and Technical Information of China (English)

    王秀峰; 李龙; 张春丽; 林朋; 崔书亚

    2012-01-01

    采用以双硫腙为络合剂、Triton X- 100为表面活性剂的新型浊点萃取体系富集淡水鱼中的痕量铅,并用火焰原子吸收光谱法对其进行测定.探讨了溶液pH、表面活性剂浓度、络合剂用量、平衡温度、平衡时间等对浊点萃取及测定灵敏度的影响,优化了实验条件.在最佳条件下测得铅的检出限为0.090μg/L,校准曲线相关系数为0.9999.该方法已用于淡水鱼中痕量铅的测定.%A new cloud point extraction-flame atomic absorption spectrometric method has been developed to determine trace lead. Dithizone was selected as the complex reagent and Triton X - 100 as the surfactant. Effects of pH, concentrations of surfactant and complex reagent, equilibrium temperature and time on the efficiency and sensitivity of cloud point extraction were investigated. Under optimal conditions, the calibration curve was linear over the concentration range of 0. 1 - 60μg/L with correlation coefficient of 0. 9999 and detection limit of 0. 090 μg/L. The present method was applied to the determination of trace lead in freshwater fish samples with satisfactory results.

  4. Freshwater savings from marine protein consumption

    International Nuclear Information System (INIS)

    Marine fisheries provide an essential source of protein for many people around the world. Unlike alternative terrestrial sources of protein, marine fish production requires little to no freshwater inputs. Consuming marine fish protein instead of terrestrial protein therefore represents freshwater savings (equivalent to an avoided water cost) and contributes to a low water footprint diet. These water savings are realized by the producers of alternative protein sources, rather than the consumers of marine protein. This study quantifies freshwater savings from marine fish consumption around the world by estimating the water footprint of replacing marine fish with terrestrial protein based on current consumption patterns. An estimated 7 600 km3 yr−1 of water is used for human food production. Replacing marine protein with terrestrial protein would require an additional 350 km3 yr−1 of water, meaning that marine protein provides current water savings of 4.6%. The importance of these freshwater savings is highly uneven around the globe, with savings ranging from as little as 0 to as much as 50%. The largest savings as a per cent of current water footprints occur in Asia, Oceania, and several coastal African nations. The greatest national water savings from marine fish protein occur in Southeast Asia and the United States. As the human population increases, future water savings from marine fish consumption will be increasingly important to food and water security and depend on sustainable harvest of capture fisheries and low water footprint growth of marine aquaculture. (paper)

  5. Minilernaea floricapitella gen. nov., sp. nov. (Copepoda, Lernaeidae from freshwater fishes of Southern Brazil Minilernaea floricapitella gen. nov., sp. nov.(Copepoda, Lernaeidae de peixes de água doce do Sul do Brazil

    Directory of Open Access Journals (Sweden)

    Vernon E. Thatcher

    2005-12-01

    Full Text Available Minilernaea floricapitella gen. nov., sp. nov. (Copepoda, Cyclopoida, Lernaeidae a parasite of the freshwater fishes, Astyanax spp. and Corydoras ehrhardti Regan, 1912 of Santa Catarina and Paraná States, Brazil, is described, based on 10 postmetamorphic females. The new genus and species has the following characteristics that distinguish it from all other known lernaeids: (1 The body is very small (3.4-5.8 mm in length; (2 The head is provided anteriorly with six lobes and posteriorly with four undivided anchor arms. (3 The first pair of thoracopods is on the head, 2-4 are all on the "neck"; (4 Thoracopod 5 is reduced to a simple papillus near the genital pores; (5 The genital pores are equatorial in the hindbody and there is no pre-genital prominence. Since the head and part of the neck are inserted beneath the skin, the host produces a strong encapsulating reaction.Minilernaea floricapitella gen. nov., sp. nov. (Copepoda, Cyclopoida, Lernaeidae um parasito dos peixes, Astyanax spp. and Corydoras ehrhardti Regan, 1912 dos estados de Santa Catarina e Paraná, Brasil, é descrita baseada em 10 fêmeas pós-metamórficas. O novo gênero e espécie tem as seguintes características que servem para distingui-la dos demais lerneídeos: (1. O corpo é muito pequeno (3.4-5.8 mm de comprimento; (2 A cabeça é provida anteriormente com seis lóbulos e posteriormente com quatro âncoras não divididas; (3 O primeiro par de toracópodos encontra-se na cabeça, quando 2-4 estão no pescoço; Toracópodo 5 é reduzido a uma papila simples perto dos poros genitais; (5 Os poros genitais são localizados na área equatorial do corpo posterior e não existe uma proeminência pre-genital. Já que a cabeça e uma parte do pescoço são inseridas sob a pele, o hospedeiro demostra uma reação encapsuladora forte.

  6. 微波消解-微分电位溶出法测定淡水鱼中镉含量%Determination on Cadmium in Freshwater Fish by Microwave Digestion-Differential Potentiometric Stripping Analysis

    Institute of Scientific and Technical Information of China (English)

    滕晓焕; 章建军

    2011-01-01

    The aim of the study was to seek a quick,simple and new method for the detection of cadmium.Study electrodeposition potential、electrodeposition time、equilibrium potential and equilibrium time that how to effect results through determining freshwater fish cadmium content by glassy carbon mercury membrane electrode electron.Results: When pH was 1.0~2.5;the electrodeposition potential was-1.25V;electrodeposition time was 60s;equilibrium potential was-1.0V;equilibrium time was 30s,the determination result was best.The linear range was at 0~16ng,the detection limit was 0.24ng/mL;the recovery was 98.6%~101.2%;the relative standard deviation was 2.4%.This method is rapid,simple,accurate and reliable.%为镉的检测寻求一种快速、简便的新方法。通过玻碳悬汞电极测定淡水鱼中镉含量,考查了电沉积电位、电沉积时间、平衡电位、平衡时间对测定结果的影响。结果:当pH值为1.0~2.5、电沉积电位为-1.25V、电沉积时间为60s、平衡电位为-1.0V、平衡时间为30s时,测定结果最好。测定镉的线性范围为0~16ng,检出限为0.24ng/mL,回收率为98.6%~101.2%,相对标准偏差为2.4%。该法操作快速、简便,结果准确、可靠。

  7. Climate and local abundance in freshwater fishes

    OpenAIRE

    Knouft, Jason H; Anthony, Melissa M.

    2016-01-01

    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 va...

  8. Markets for Canadian oil

    International Nuclear Information System (INIS)

    This conference presentation presented charts and graphs on the market for Canadian oil. Graphs included crude oil and natural gas prices and heavy oil discount differential. Graphs depicting heavy oil economics such as bitumen blending with condensate were also included along with global crude oil reserves by country. Information on oil sands projects in the Athabasca, Peace River, and Cold Lake deposits was presented along with graphs on oil sands supply costs by recovery type; Canadian production for conventional, oil sands and offshore oil; new emerging oil sands crude types; and 2003 market demand by crude type in the United States and Canada. Maps included Canada and United States crude oil pipelines; western Canadian crude oil markets; long term oil pipeline expansion projects; Canadian and United States crude oil pipeline alternatives; and potential tanker markets for Canadian oil sands production. Lastly, the presentation provided graphs on 2003 refinery crude demand and California market demand. tabs., figs

  9. CROATIAN FRESHWATER FISHERY IN 2001 and 2002

    Directory of Open Access Journals (Sweden)

    Irena Jahutka

    2003-09-01

    Full Text Available For each segment of freshwater fisheries — freshwater aquaculture, commercial and sport and recreational fisheries — there is a legal obligation for data submission to the Ministry of agriculture and forestry, Directorate of fisheries. Within the segments of commercial and sport and recreational fisheries the data submission obligation refers to the period beginning with the year 2003, while in the segment of aquaculture that obligation includes also the year 2002. Data collected for freshwater aquaculture contain the information on production of freshwater fish, total production areas, food, fertilizers and subsidies for freshwater fish farming. Data collected for commercial and sport and recreational fisheries contain the information on catch quantities and number of commercial and sport and recreational fishermen. Freshwater fish production in the year 2001 was 5,549. 50 tons, while the total fresh water fish production in the year 2002 decreased for 1.00% compared to the previous year, amounting to 5,501.07 tons. Although total fresh water fish production constantly decreases comparing to previous years, trout production has increased and the maximum production was noted in the year 2002. Total area of the freshwater fish farms in the year 2001 increased compared to the year 2000 for 2.14% amounting to 11,880.41 ha. Actual production area slightly increased in comparison to the previous year as well and amounted to 9,214.11 ha. In the year 2002 total area of freshwater fish farms was 11,491.29 ha, and 72.13% of that figure was the actual production area, that is 8,288.27 ha. Production per unit area in the year 2001 was 485.31 kg/ha for warm–water species and 280.44 t/ha for cold–water species. In the year 2002 production per unit area for warm–water species was 462.95 kg/ha, and for cold–water species 315.26 t/ha. During the year 2001, in total, 10,575.82 t of food was spent and 1,891 tons of fertilizers and lime, while in the

  10. FRESHWATER FISHERY OF THE REPUBLIC OF CROATIA

    Directory of Open Access Journals (Sweden)

    Zlatko Homen

    1999-09-01

    Full Text Available As fishery, including freshwater, is very important for economy of the Republic of Croatia, the aim of this paper is to show its condition from 1995 to 1998. and also to draw a plan for fish production in 1999. The period from 1998-1999. is more stressed in order to have a total and detailed view into the present condition of the freshwater fishery and into the direction in wish that production is going. Data about carp ponds and also about trout ponds is presented. Twentynine fish-ponds are processed out of which 20 are carp ponds and 9 trout ponds. Data was delivered to the Ministry of Agriculture and Forestry Fisheries Directorate. An assessment of the condition is made for 3 fish-ponds as the desired data was not provided. As to the number of employees on fish-ponds, a slight decline could be percived in the period from 1995 to 1997. In 1998 a number of employees considerably increased for 10.07% in relation to 1997. qualification of the employees in 1998. show that the most of them are unqualified what is in accord with the requirements of a job on a fish-pond. Overall surface of the carp ponds in 1998 was 12,708 and the production surface was 9,782 ha. The most of the fish-ponds have up to 500 ha of total surface (45.45%, while 50% of the fish-ponds have production surface from 500-100 ha. The production in the trout ponds is made on 165,905 m 2 of the overall surface of the ponds, and only 40,538 m 2 are the production surface of the ponds. The production of fish in that period was in constant increase and that increasing trend in expected in 1999, and it will be an 28.30 % increase in relation to 1998. The increase is expected for all kids of fish except for big head carps, silver carps and tinch fishs. As a part of the production of tinch fishs an increase in production of consumption tinch fish is expected, but a decrease in production of one-year and two-year old fishs and two-year old fish. Out of all kinds of fish, the most produced

  11. Salmonid & freshwater Fisheries statistics England & Wales 1996

    OpenAIRE

    1997-01-01

    This is the Salmonid & Freshwater Fisheries Statistics for England & Wales 1996 produced by the Environment Agency in 1997. The principal aim of the Environment Agency in respect of fisheries is to maintain improve and develop fish stocks, the basic fisheries resource, in order to optimise the social and economic benefits from their sustainable exploitation. This report is the second collation of salmon and migratory trout catch statistics for England and Wales produced by the Environment Ag...

  12. Monitoring endangered freshwater biodiversity using environmental DNA

    DEFF Research Database (Denmark)

    Thomsen, Philip Francis; Kielgast, Jos; Iversen, Lars L.;

    2012-01-01

    that depend on practical and taxonomic expertise, which is rapidly declining. Here, we show that a diversity of rare and threatened freshwater animals-representing amphibians, fish, mammals, insects and crustaceans-can be detected and quantified based on DNA obtained directly from small water samples of lakes...... of amphibians and fish can be detected by high-throughput sequencing of DNA extracted from pond water. Our findings underpin the ubiquitous nature of DNA traces in the environment and establish environmental DNA as a tool for monitoring rare and threatened species across a wide range of taxonomic groups....

  13. Some data on the polar bear and its utilization in the Canadian Arctic

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Some data have been collected on the polar bear kill and its utilization, based on information from 14 to 26 coastal settlements in the Canadian Arctic. Tt seems...

  14. Freshwater autotrophic picoplankton: a review

    Directory of Open Access Journals (Sweden)

    John G. STOCKNER

    2002-02-01

    Full Text Available Autotrophic picoplankton (APP are distributed worldwide and are ubiquitous in all types of lakes of varying trophic state. APP are major players in carbon production in all aquatic ecosystems, including extreme environments such as cold ice-covered and/or warm tropical lakes and thermal springs. They often form the base of complex microbial food webs, becoming prey for a multitude of protozoan and micro-invertebrate grazers, that effectively channel APP carbon to higher trophic levels including fish. In this review we examine the existing literature on freshwater autotrophic picoplankton, setting recent findings and current ecological issues within an historic framework, and include a description of the occurrence and distribution of both single-cell and colonial APP (picocyanobacteria in different types of lakes. In this review we place considerable emphasis on methodology and ecology, including sampling, counting, preservation, molecular techniques, measurement of photosynthesis, and include extensive comment on their important role in microbial food webs. The model outlined by Stockner of an increase of APP abundance and biomass and a decrease of its relative importance with the increase of phosphorus concentration in lakes has been widely accepted, and only recently confirmed in marine and freshwater ecosystems. Nevertheless the relationship which drives the APP presence and importance in lakes of differing trophic status appears with considerable variation so we must conclude that the success of APP in oligotrophic lakes worldwide is not a certainty but highly probable.

  15. Preparation of Flavorful Sauce from Freshwater Fish By-products by Enzymatic Hydrolysis and then Fermentation%淡水鱼下脚料酶解酿制风味调味汁

    Institute of Scientific and Technical Information of China (English)

    姚芳; 祁兴普; 刘萍

    2012-01-01

    Based on one-factor-at-a-time experiments,orthogonal array design method was employed to optimize the preparation of flavorful sauce from freshwater fish by-products by enzymatic hydrolysis followed by fermentation.The highest degree of hydrolysis was achieved when a mixture of flavorzyme and alcalase at a ratio of 1:1 was added at a dose of 0.25 g/100 g for 4 h of hydrolysis at 55 ℃ and pH 7.5.The hydrolysate was completely deodorized after 1 h of fermentation at 35 ℃ with yeast at an inoculum size of 2.0 g/100 g.The Maillard reaction products of the fermentation broth obtained after reaction at 115 ℃ for 40 min in the presence of a mixture of xylose and glucose(1:3) at a concentration of 4 g/100 g and L-cysteine hydrochloride at 1.0 g/100 g showed the highest sensory score.The flavorful sauce obtained revealed a strong meat and sauce flavor and no fishy odor.The free amino nitrogen content was 0.86 g/100 mL.Thus,it is a natural seasoning with great development potential.%在单因素试验基础上,通过正交试验对利用淡水鱼下脚料制备鱼酿调味汁的工艺技术进行优化。结果表明:最适酶解反应工艺条件为添加蛋白酶(风味蛋白酶:碱性蛋白酶=1:1)0.25g/100g,在55℃、pH7.5条件下酶解4h;最适发酵工艺条件为添加2.0g/100g酵母在35℃条件下发酵1h;最适美拉德反应的工艺条件为添加还原糖(木糖:葡萄糖=1:3)4g/100g、L-半胱氨酸盐酸盐1.0g/100g,在115℃条件下反应40min。研制出的调味汁有浓郁的肉香味和酱香味,无鱼腥味,游离态氨基酸态氮含量0.86g/100mL,是一种很有发展潜力的天然调味品。

  16. 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

  17. Freshwater variability in the Arctic: Tracing freshwater sources and quantities from 2005 to 2011 in a transect from Ellesmere Island, Canada to the North Pole

    Science.gov (United States)

    Motz, E. A.; Smethie, W. M.

    2011-12-01

    The Switchyard project has gathered data across the Canadian Basin to determine the Arctic Ocean's fractional freshwater composition from three sources: Pacific water, meteoric water (river runoff and precipitation), and sea ice melt water. With a database of the project extending to 2005 as well as using earlier projects' data to date back further, we can view trends and visualize changes in the freshwater content of the Arctic Ocean. In the past decade the Arctic has experienced increases in freshwater with the largest increases from meteoric fractions. In 2008 there was a major increase in meteoric water and decreases in Pacific freshwater fractions. This could be related to the extreme decrease in summer sea ice of 2007. Freshwater inventories across the Canadian Basin vary over the years and show a relationship in the mixed layer of increasing when the Arctic Oscillation (AO) is positive and freshwater is released from the Beaufort Gyre.1 Increases in the quantity of freshwater in the Arctic could lead to greater freshwater exports to the North Atlantic Ocean. This can inhibit the formation of North Atlantic Deep Water and so affect the global thermohaline circulation which moderates much of our planet's climate.2 1 Jones et al. 2008, Pacific freshwater, river water and sea ice meltwater across Arctic Ocean basins: Results from the 2005 Beringia Expedition, Journal of Geophysical Research vol 113, C08012, doi:10.1029/2007JC004124. 32Morison et al. 1998, Hydrography of the upper Arctic Ocean measured from the nuclear submarine U.S.S. Pargo, Deep Sea Research Part I, vol 45, 15-38.

  18. Cholinesterase activity as a device for biomonitoring pesticide exposure in the freshwater mussel Elliptio complanata

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — A die-off of freshwater mussels in 1990, attributed to anticholinesterase pesticide contamination of a North Carolina stream, has led the National Biological...

  19. Developing water quality standards for recovery of imperiled freshwater mussels (family Unionidae)

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Many factors are cited in the decline of freshwater mussel (Family Unionidae) populations in North America and for the listing of greater than 70% of native unionid...

  20. A study on the levels of radioactivity in fish samples from the experimental lakes area in Ontario, Canada.

    Science.gov (United States)

    Chen, Jing; Rennie, Michael D; Sadi, Baki; Zhang, Weihua; St-Amant, Nadereh

    2016-03-01

    To better understand background radiation levels in country foods, a total of 125 fish samples were collected from three lakes (Lake 226, Lake 302 and Lake 305) in the Experimental Lakes Area (ELA) in Ontario of Canada during the summer of 2014. Concentrations of naturally occurring radionuclides ((226)Ra, (210)Pb and (210)Po) as well as anthropogenic radionuclides ((134)Cs and (137)Cs) were measured. This study confirmed that (210)Po is the dominant contributor to radiation doses resulting from fish consumption. While concentrations of (210)Pb and (226)Ra were below conventional detection limits, (210)Po was measured in almost all fish samples collected from the ELA. The average concentration was about 1.5 Bq/kg fresh weight (fw). None of the fish samples analysed in this study contained any detectable levels of (134)Cs. An average (137)Cs level of 6.1 Bq/kg fw was observed in freshwater fishes harvested in the ELA, almost twice that of samples measured in the National Capital Region of Canada in 2014 and more than 20 times higher than the levels observed in marine fish harvested from the Canadian west coast in 2013 and 2014. However, it is important to note that the concentrations of (137)Cs in fish samples from these inland lakes are considered very low from a radiological protection perspective. The resulting radiation dose for people from fish consumption would be a very small fraction of the annual dose from exposure to natural background radiation in Canada. The results indicate that fishes from inland lakes do not pose a radiological health concern. PMID:26803403

  1. Gastric cryptosporidiosis in freshwater angelfish (Pterophyllum scalare).

    Science.gov (United States)

    Murphy, Brian G; Bradway, Daniel; Walsh, Timothy; Sanders, George E; Snekvik, Kevin

    2009-09-01

    A freshwater angelfish (Pterophyllum scalare) hatchery experienced variable levels of emaciation, poor growth rates, swollen coelomic cavities, anorexia, listlessness, and increased mortality within their fish. Multiple chemotherapeutic trials had been attempted without success. In affected fish, large numbers of protozoa were identified both histologically and ultrastructurally associated with the gastric mucosa. The youngest cohort of parasitized fish was the most severely affected and demonstrated the greatest morbidity and mortality. The protozoa were morphologically most consistent with Cryptosporidium. All of the protozoan life stages were identified ultrastructurally and protozoal genomic DNA was isolated from parasitized tissue viscera and sequenced. Histological, ultrastructural, genetic, and phylogenetic analyses confirmed this protozoal organism to be a novel species of Cryptosporidium. PMID:19737774

  2. Canadian beef quality audit.

    OpenAIRE

    Van Donkersgoed, J; Jewison, G; M. Mann; Cherry, B; Altwasser, B; Lower, R; Wiggins, K; Dejonge, R; Thorlakson, B; Moss, E.; C. Mills; Grogan, H

    1997-01-01

    A study was conducted in 4 Canadian processing plants in 1995-96 to determine the prevalence of quality defects in Canadian cattle. One percent of the annual number of cattle processed in Canada were evaluated on the processing floor and 0.1% were graded in the cooler. Brands were observed on 37% and multiple brands on 6% of the cattle. Forty percent of the cattle had horns, 20% of which were scurs, 33% were stubs, 10% were tipped, and 37% were full length. Tag (mud and manure on the hide) wa...

  3. Canadian Irradiation Centre

    International Nuclear Information System (INIS)

    The Canadian Irradiation Centre is a non-profit cooperative project between Atomic Energy of Canada Limited, Radiochemical Company and Universite du Quebec, Institut Armand-Frappier, Centre for Applied Research in Food Science. The Centre's objectives are to develop, demonstrate and promote Canada's radiation processing technology and its applications by conducting applied research; training technical, professional and scientific personnel; educating industry and government; demonstrating operational and scientific procedures; developing processing procedures and standards, and performing product and market acceptance trials. This pamphlet outlines the history of radoation technology and the services offered by the Canadian Irradiation Centre