WorldWideScience

Sample records for forage fish species

  1. Trace elements in Antarctic fish species and the influence of foraging habitats and dietary habits on mercury levels

    Energy Technology Data Exchange (ETDEWEB)

    Goutte, Aurélie, E-mail: aurelie.goutte@ephe.sorbonne.fr [École Pratique des Hautes Études (EPHE), SPL, UPMC Univ Paris 06, UMR 7619 METIS, F-75005, 4 place Jussieu, Paris (France); Cherel, Yves [Centre d' Etudes Biologiques de Chizé, UMR 7372, CNRS-Université de La Rochelle, 79360 Villiers-en-Bois (France); Churlaud, Carine [Littoral Environnement et Sociétés (LIENSs), UMR 7266, CNRS-Université de la Rochelle, 2 rue Olympe de Gouges, 17000 La Rochelle (France); Ponthus, Jean-Pierre [École Pratique des Hautes Études (EPHE), SPL, UPMC Univ Paris 06, UMR 7619 METIS, F-75005, 4 place Jussieu, Paris (France); Massé, Guillaume [Unité Mixte Internationale Takuvik, Pavillon Alexandre-Vachon, Université Laval, QC, Québec (Canada); Bustamante, Paco [Littoral Environnement et Sociétés (LIENSs), UMR 7266, CNRS-Université de la Rochelle, 2 rue Olympe de Gouges, 17000 La Rochelle (France)

    2015-12-15

    This study aims at describing and interpreting concentration profiles of trace elements in seven Antarctic fish species (N = 132 specimens) off Adélie Land. Ichthyofauna plays a key role in the Antarctic ecosystem, as they occupy various ecological niches, including cryopelagic (ice-associated), pelagic, and benthic habitats. Firstly, trace element levels in the studied specimens were similar to those previously observed in fish from the Southern Ocean. Apart from manganese and zinc, concentrations of arsenic, cadmium, copper, iron, mercury (Hg), nickel, selenium and silver differed among fish species. Muscle δ{sup 13}C and δ{sup 15}N values were determined to investigate whether the fish foraging habitats and dietary habits could explain Hg levels. Species and foraging habitat (δ{sup 13}C) were strong predictors for variations of Hg concentrations in muscle tissues. The highest Hg contamination was found in shallow benthic fish compared to cryopelagic and pelagic fish. This pattern was likely due to the methylation of Hg in the coastal sediment and the photodemethylation by ultraviolet radiation in surface waters. - Highlights: • Trace elements and stable isotopes were analyzed in seven Antarctic fish species. • Levels of trace elements in liver and in muscle differed among species. • Hg load was higher in benthic fish than in cryopelagic and pelagic fish. • These findings could be due to the high methylation rate of Hg in the sediment.

  2. Trace elements in Antarctic fish species and the influence of foraging habitats and dietary habits on mercury levels

    International Nuclear Information System (INIS)

    Goutte, Aurélie; Cherel, Yves; Churlaud, Carine; Ponthus, Jean-Pierre; Massé, Guillaume; Bustamante, Paco

    2015-01-01

    This study aims at describing and interpreting concentration profiles of trace elements in seven Antarctic fish species (N = 132 specimens) off Adélie Land. Ichthyofauna plays a key role in the Antarctic ecosystem, as they occupy various ecological niches, including cryopelagic (ice-associated), pelagic, and benthic habitats. Firstly, trace element levels in the studied specimens were similar to those previously observed in fish from the Southern Ocean. Apart from manganese and zinc, concentrations of arsenic, cadmium, copper, iron, mercury (Hg), nickel, selenium and silver differed among fish species. Muscle δ"1"3C and δ"1"5N values were determined to investigate whether the fish foraging habitats and dietary habits could explain Hg levels. Species and foraging habitat (δ"1"3C) were strong predictors for variations of Hg concentrations in muscle tissues. The highest Hg contamination was found in shallow benthic fish compared to cryopelagic and pelagic fish. This pattern was likely due to the methylation of Hg in the coastal sediment and the photodemethylation by ultraviolet radiation in surface waters. - Highlights: • Trace elements and stable isotopes were analyzed in seven Antarctic fish species. • Levels of trace elements in liver and in muscle differed among species. • Hg load was higher in benthic fish than in cryopelagic and pelagic fish. • These findings could be due to the high methylation rate of Hg in the sediment.

  3. Mercury in San Francisco Bay forage fish

    Energy Technology Data Exchange (ETDEWEB)

    Greenfield, Ben K., E-mail: ben@sfei.or [San Francisco Estuary Institute, 7770 Pardee Lane, Oakland, CA 94621 (United States); Jahn, Andrew, E-mail: andyjahn@mac.co [1000 Riverside Drive, Ukiah, CA 95482 (United States)

    2010-08-15

    In the San Francisco Estuary, management actions including tidal marsh restoration could change fish mercury (Hg) concentrations. From 2005 to 2007, small forage fish were collected and analyzed to identify spatial and interannual variation in biotic methylmercury (MeHg) exposure. The average whole body total Hg concentration was 0.052 {mu}g g{sup -1} (wet-weight) for 457 composite samples representing 13 fish species. MeHg constituted 94% of total Hg. At a given length, Hg concentrations were higher in nearshore mudflat and wetland species (Clevelandia ios, Menidia audens, and Ilypnus gilberti), compared to species that move offshore (e.g., Atherinops affinis and Lepidogobius lepidus). Gut content analysis indicated similar diets between Atherinops affinis and Menidia audens, when sampled at the same locations. Hg concentrations were higher in sites closest to the Guadalupe River, which drains a watershed impacted by historic Hg mining. Results demonstrate that despite differences among years and fish species, nearshore forage fish exhibit consistent Hg spatial gradients. - Total mercury in estuarine forage fish varies with species, habitat, and proximity to a historic mercury mine.

  4. Mercury in San Francisco Bay forage fish

    International Nuclear Information System (INIS)

    Greenfield, Ben K.; Jahn, Andrew

    2010-01-01

    In the San Francisco Estuary, management actions including tidal marsh restoration could change fish mercury (Hg) concentrations. From 2005 to 2007, small forage fish were collected and analyzed to identify spatial and interannual variation in biotic methylmercury (MeHg) exposure. The average whole body total Hg concentration was 0.052 μg g -1 (wet-weight) for 457 composite samples representing 13 fish species. MeHg constituted 94% of total Hg. At a given length, Hg concentrations were higher in nearshore mudflat and wetland species (Clevelandia ios, Menidia audens, and Ilypnus gilberti), compared to species that move offshore (e.g., Atherinops affinis and Lepidogobius lepidus). Gut content analysis indicated similar diets between Atherinops affinis and Menidia audens, when sampled at the same locations. Hg concentrations were higher in sites closest to the Guadalupe River, which drains a watershed impacted by historic Hg mining. Results demonstrate that despite differences among years and fish species, nearshore forage fish exhibit consistent Hg spatial gradients. - Total mercury in estuarine forage fish varies with species, habitat, and proximity to a historic mercury mine.

  5. Forage fish, their fisheries, and their predators: who drives whom?

    DEFF Research Database (Denmark)

    Engelhard, Georg H.; Peck, Myron A.; Rindorf, Anna

    2014-01-01

    exist, as in the North Sea. Sandeel appears to be the most important prey forage fish. Seabirds are most dependent on forage fish, due to specialized diet and distributional constraints (breeding colonies). Other than fisheries, key predators of forage fish are a few piscivorous fish species including...... saithe, whiting, mackerel, and horse-mackerel, exploited in turn by fisheries; seabirds and seals have a more modest impact. Size-based foodwebmodelling suggests that reducing fishing mortality may not necessarily lead to larger stocks of piscivorous fish, especially if their early life stages compete...

  6. Effect of forage quality in faeces from different ruminant species fed high and low quality forage

    DEFF Research Database (Denmark)

    Jalali, A R; Nørgaard, P; Nielsen, M O

    2010-01-01

    Effect of forage quality in faeces from different ruminant species fed high and low quality forage......Effect of forage quality in faeces from different ruminant species fed high and low quality forage...

  7. Asymmetric competition, body size, and foraging tactics: testing the ideal free distribution in two competing fish species

    Czech Academy of Sciences Publication Activity Database

    Berec, M.; Křivan, Vlastimil; Berec, Luděk

    2006-01-01

    Roč. 8, č. 5 (2006), s. 929-942 ISSN 1522-0613 R&D Projects: GA AV ČR(CZ) IAA6007303; GA AV ČR IAA100070601 Institutional research plan: CEZ:AV0Z50070508 Keywords : allopatric species * asymmetric competititon * body size Subject RIV: EH - Ecology, Behaviour Impact factor: 1.785, year: 2006

  8. Diet variability of forage fishes in the Northern California Current System

    Science.gov (United States)

    Hill, Andrew D.; Daly, Elizabeth A.; Brodeur, Richard D.

    2015-06-01

    As fisheries management shifts to an ecosystem-based approach, understanding energy pathways and trophic relationships in the Northern California Current (NCC) will become increasingly important for predictive modeling and understanding ecosystem response to changing ocean conditions. In the NCC, pelagic forage fishes are a critical link between seasonal and interannual variation in primary production and upper trophic groups. We compared diets among dominant forage fish (sardines, anchovies, herring, and smelts) in the NCC collected in May and June of 2011 and June 2012, and found high diet variability between and within species on seasonal and annual time scales, and also on decadal scales when compared to results of past studies conducted in the early 2000s. Copepoda were a large proportion by weight of several forage fish diets in 2011 and 2012, which differed from a preponderance of Euphausiidae found in previous studies, even though all years exhibited cool ocean conditions. We also examined diet overlap among these species and with co-occurring subyearling Chinook salmon and found that surf smelt diets overlapped more with subyearling Chinook diets than any other forage fish. Herring and sardine diets overlapped the most with each other in our interdecadal comparisons and some prey items were common to all forage fish diets. Forage fish that show plasticity in diet may be more adapted to ocean conditions of low productivity or anomalous prey fields. These findings highlight the variable and not well-understood connections between ocean conditions and energy pathways within the NCC.

  9. Mercury in Forage Fish from Mexico and Central America: Implications for Fish-Eating Birds.

    Science.gov (United States)

    Elliott, John E; Kirk, David A; Elliott, Kyle H; Dorzinsky, Jessica; Lee, Sandi; Inzunza, Ernesto Ruelas; Cheng, Kimberly M T; Scheuhammer, Tony; Shaw, Patrick

    2015-11-01

    Mercury (Hg) is a global contaminant of aquatic food chains. Aquatic birds, such as the osprey (Pandion haliaetus), with migratory populations breeding in Canada and the northern United States and wintering in the Central and South America, can be exposed to mercury on both the breeding and wintering ranges. We examined Hg levels in 14 fish taxa from 24 osprey wintering sites identified from satellite telemetry. Our main goal was to determine whether fish species that feature in the diet of overwintering and resident fish-eating birds reached toxicity thresholds for Hg. Mean Hg levels in fish whole carcasses ranged from a high of 0.18 µg g(-1) (wet weight) in Scomberomorus sierra to a low of 0.009 µg g(-1) in Catostomidae. Average Hg levels were within published toxicity threshold values in forage fish for only two sites in Mexico (Puerto Vallarta and San Blas Estuary), and all were marine species, such as mackerel (Scomberomorus sierra), sea catfish (Ariopus spp.), and sardinas species (Centropomus spp.). Except for one sample from Nicaragua, sea catfish from Puerto Morazan, none of the fish from sites in Central America had Hg levels which exceeded the thresholds. Nonmetric multidimensional scaling revealed geographical differences in Hg levels with significant pairwise differences between sites along the Pacific Ocean (Mexico) versus the Bay of Campeche, partly due to differences in species composition of sampled fish (and species distributions). Hg increased with trophic level, as assessed by nitrogen stable isotope ratios (δ(15)N but not δ(13)C), in freshwater and marine, but not estuarine, environments. Hg concentrations in forage fish do not account for the elevated Hg reported for many osprey populations on the breeding grounds, thus primary sources of contamination appear to be in the north.

  10. Physiology, phenology and behavioural strategies of forage fish

    DEFF Research Database (Denmark)

    Frisk, Christina

    Forage fish are small individuals, and are very abundant in numbers and can form dense schools. Forage fish are important within the food webs of the oceans, as they are at the lower trophic levels. Forage fish prey on zooplankton and they are themselves preyed on by piscivore fish. The individual...... forage fish and its growth dynamics are governed by an interplay between physiological rates, e.g. metabolism and consumption and the ambient environment as the rates are temperature dependent. The topic of this thesis is to describe the strong link between the individual and the environment through....... The model includes an additional structure pool; gonads, to which energy is transferred during the spawning season. During periods of poor feeding, energy to cover metabolic costs are firstly taken from the reserve pool and secondly, if the reserves are depleted, from the somatic tissue pool. The model...

  11. Fatty acid composition of forage herb species

    DEFF Research Database (Denmark)

    Warner, D.; Jensen, Søren Krogh; Cone, J.W.

    2010-01-01

    The use of alternative forage species in grasslands for intensive livestock production is receiving renewed attention. Data on fatty acid composition of herbs are scarce, so four herbs (Plantago lanceolata, Achillea millefolium, Cichorium intybus, Pastinaca sativa) and one grass species (timothy......, Phleum pratense) were sown in a cutting trial. The chemical composition and concentration of fatty acids (FA) of individual species were determined during the growing season. Concentrations of crude protein and FA were generally higher in the herbs than in timothy. C. intybus had the highest nutritive...

  12. Evaluation of nutritional value some forage species available in Iran ...

    African Journals Online (AJOL)

    Novin

    2012-07-17

    Jul 17, 2012 ... and chemical composition of forage species was estimated. MATERIALS AND METHODS ... head per day at 8.00 a.m. and 6.00 p.m. Forage samples (2 g DM with 2 mm screen ) were weighed into nylon bags ..... methods to study the kinetics of degradation of forage species, instead of the in situ technique, ...

  13. Has eutrophication promoted forage fish production in the Baltic Sea?

    DEFF Research Database (Denmark)

    Eero, Margit; Andersson, Helén C; Almroth-Rosell, Elin

    2016-01-01

    Reducing anthropogenic nutrient inputs is a major policy goal for restoring good environmental status of coastal marine ecosystems. However, it is unclear to what extent reducing nutrients would also lower fish production and fisheries yields. Empirical examples of changes in nutrient loads...... and concurrent fish production can provide useful insights to this question. In this paper, we investigate to what extent a multi-fold increase in nutrient loads from the 1950s to 1980s enhanced forage fish production in the Baltic Sea. We use monitoring data on fish stock dynamics covering the period...

  14. Conservation and Ecology of Marine Forage Fishes--Proceedings of a Research Symposium, September 2012

    Science.gov (United States)

    Liedtke, Theresa; Gibson, Caroline; Lowry, Dayv; Fagergren, Duane

    2013-01-01

    Locally and globally, there is growing recognition of the critical roles that herring, smelt, sand lance, eulachon, and other forage fishes play in marine ecosystems. Scientific and resource management entities throughout the Salish Sea, agree that extensive information gaps exist, both in basic biological knowledge and parameters critical to fishery management. Communication and collaboration among researchers also is inadequate. Building on the interest and enthusiasm generated by recent forage fish workshops and symposia around the region, the 2012 Research Symposium on the Conservation and Ecology of Marine Forage Fishes was designed to elucidate practical recommendations for science and policy needs and actions, and spur further collaboration in support for the precautionary management of forage fish. This dynamic and productive event was a joint venture of the Northwest Straits Commission Forage Fish Program, U.S. Geological Survey (USGS), Washington Department of Fish and Wildlife (WDFW), and The Puget Sound Partnership. The symposium was held on September 12–14, 2012, at the University of Washington, Friday Harbor Laboratories campus. Sixty scientists, graduate students, and fisheries policy experts convened; showcasing ongoing research, conservation, and management efforts targeting forage fish from regional and national perspectives. The primary objectives of this event were to: (1) review current research and management related to marine forage fish species; and (2) identify priority science and policy needs and actions for Washington, British Columbia, and the entire West Coast. Given the diversity of knowledge, interests, and disciplines surrounding forage fish on both sides of the international border, the organizing committee made a concerted effort to contact many additional experts who, although unable to attend, provided valuable insights and ideas to the symposium structure and discussions. The value of the symposium format was highlighted in

  15. Development of forage cryo minced fish technology

    Directory of Open Access Journals (Sweden)

    Titova S. A.

    2017-11-01

    Full Text Available The technology of grinding the frozen fish raw material using the useful model of a piston-type extrusion plant with cold working bodies for fodder minced fish (cryo minced fish feed by the method of cryoextrusion has been developed. The possibility of replacing the standard manufacturing operations (defrosting and subsequent grinding of raw materials to the one (cryoextrusion has been substantiated. The optimal shape of holes of the die for forcing the raw material has been determined in the form of "hourglass", the hole diameter is 7 mm, the length of the process of pushing is 40 s. It has been established that the finished product (cryo minced fish feed has a homogeneous grinding, juicy, crumbly texture, the temperature in the thickness of the product is equal to the temperature of the raw material before processing (–18 °C. The technological scheme of producing the minced fish feed by the method of cryoextrusion has been developed. Researching the chemical composition of fish and feed of mince produced by the traditional and developed methods it has been established that protein content in the cryo minced fish feed remains unchanged. The amino acid composition of cryo minced fish feed has been determined, the amount of essential amino acids is 365.6 mg/g of protein. In the proteins of the cryo minced fish feed methionine has been contained in the minimum quantity (10.0 mg/g protein and in the maximum – serine (155.3 mg/g protein. In the protein of the cryo minced fish feed the only limiting amino acid is methionine. The coefficient of rationality of the cryo minced fish feed whiting is equal to 0.33. The product is not toxic, is not subject to contamination with dangerous microorganisms, has high biological value, contains necessary in animal nutrition mineral elements, the energy value per 100 g of the product is 87 kcal. The combination of the processes of cryoextrusion and lyophilization allows to obtain a new food product with high

  16. Optimal Foraging for Multiple Resources in Several Food Species

    NARCIS (Netherlands)

    Hengeveld, G.M.; Langevelde, van F.; Groen, T.A.; Knegt, de H.J.

    2009-01-01

    The concentrations of resources in forage are not perfectly balanced to the needs of an animal, and food species differ in these concentrations. Under many circumstances, animals should thus forage on multiple food species to attain the maximum and most balanced intake of several resources. In this

  17. Optimal foraging for multiple resources in several food species

    NARCIS (Netherlands)

    Hengeveld, G.M.; van Langevelde, F.; Groen, T.A.; de Knegt, H.J.

    2009-01-01

    The concentrations of resources in forage are not perfectly balanced to the needs of an animal, and food species differ in these concentrations. Under many circumstances, animals should thus forage on multiple food species to attain the maximum and most balanced intake of several resources. In this

  18. CHEMICAL COMPOSITION OF CAATINGA POTENTIAL FORAGES SPECIES

    Directory of Open Access Journals (Sweden)

    Dynara Layza de Souza da Silva

    2015-12-01

    Full Text Available Chemical composition of some potential forages species, natives from Caatinga region, were evaluated. Samples of Macroptilium heterophyllum, Stylosanthes humilis, Rhynchosia mínima, Desmodium tortuosum Sw. Dc, Merremia aegyptia, Mimosa tenuiflora Wild, Bauhinia cheilantha and as well Macroptilium lathyroides, Caesalpinia pyramidalis and Mimosa tenuiflora hays were collected in Rio Grande do Norte Stated, during 2011 rainy season. The analyses: dry matter (DM, crude protein (CP mineral matter (MM ether extract  (EE neutral detergent fiber (NDF, acid detergent fiber (ADF, lignin (LIG, insoluble neutral detergent nitrogen, (INDN insoluble acid detergent nitrogen, (ADIN, total phenol (TF and total tannin (TT were done at Embrapa Caprinos e Ovinos in Ceará State. Plants analyzed, as expected, for tropical species, exhibited high level of cell wall constituents, high lignifications rate and revealed substantial presence of anti nutritional compounds. However, regardless of this data, the main problem, for grazing animals, is due to its xerophytes characteristics. Most of the shrubs and trees are deciduous, losing its leaves during the dry season. In addition, herbaceous presents a very rapid lifetime cycle, germinating and senescing during the brief wet season.

  19. Puffins reveal contrasting relationships between forage fish and ocean climate in the North Pacific

    Science.gov (United States)

    Sydeman, William J.; Piatt, John F.; Thompson, Sarah Ann; Garcia-Reyes, Marisol; Hatch, Scott A.; Arimitsu, Mayumi L.; Slater, Leslie; Williams, Jeffrey C.; Rojek, Nora A.; Zador, Stephani G.; Renner, Heather M.

    2017-01-01

    Long-term studies of predator food habits (i.e., ‘predator-based sampling’) are useful for identifying patterns of spatial and temporal variability of forage nekton in marine ecosystems. We investigated temporal changes in forage fish availability and relationships to ocean climate by analyzing diet composition of three puffin species (horned puffin Fratercula corniculata, tufted puffin Fratercula cirrhata, and rhinoceros auklet Cerorhinca monocerata) from five sites in the North Pacific from 1978–2012. Dominant forage species included squids and hexagrammids in the western Aleutians, gadids and Pacific sand lance (Ammodytes personatus) in the eastern Aleutians and western Gulf of Alaska (GoA), and sand lance and capelin (Mallotus villosus) in the northern and eastern GoA. Interannual fluctuations in forage availability dominated variability in the western Aleutians, whereas lower-frequency shifts in forage fish availability dominated elsewhere. We produced regional multivariate indicators of sand lance, capelin, and age-0 gadid availability by combining data across species and sites using Principal Component Analysis, and related these indices to environmental factors including sea level pressure (SPL), winds, and sea surface temperature (SST). There was coherence in the availability of sand lance and capelin across the study area. Sand lance availability increased linearly with environmental conditions leading to warmer ocean temperatures, whereas capelin availability increased in a non-linear manner when environmental changes led to lower ocean temperatures. Long-term studies of puffin diet composition appear to be a promising tool for understanding the availability of these difficult-to-survey forage nekton in remote regions of the North Pacific.

  20. Odours from marine plastic debris induce food search behaviours in a forage fish.

    Science.gov (United States)

    Savoca, Matthew S; Tyson, Chris W; McGill, Michael; Slager, Christina J

    2017-08-16

    Plastic pollution is an anthropogenic stressor in marine ecosystems globally. Many species of marine fish (more than 50) ingest plastic debris. Ingested plastic has a variety of lethal and sublethal impacts and can be a route for bioaccumulation of toxic compounds throughout the food web. Despite its pervasiveness and severity, our mechanistic understanding of this maladaptive foraging behaviour is incomplete. Recent evidence suggests that the chemical signature of plastic debris may explain why certain species are predisposed to mistaking plastic for food. Anchovy ( Engraulis sp.) are abundant forage fish in coastal upwelling systems and a critical prey resource for top predators. Anchovy ingest plastic in natural conditions, though the mechanism they use to misidentify plastic as prey is unknown. Here, we presented wild-caught schools of northern anchovy ( Engraulis mordax ) with odour solutions made of plastic debris and clean plastic to compare school-wide aggregation and rheotactic responses relative to food and food odour presentations. Anchovy schools responded to plastic debris odour with increased aggregation and reduced rheotaxis. These results were similar to the effects food and food odour presentations had on schools. Conversely, these behavioural responses were absent in clean plastic and control treatments. To our knowledge, this is the first experimental evidence that adult anchovy use odours to forage. We conclude that the chemical signature plastic debris acquires in the photic zone can induce foraging behaviours in anchovy schools. These findings provide further support for a chemosensory mechanism underlying plastic consumption by marine wildlife. Given the trophic position of forage fish, these findings have considerable implications for aquatic food webs and possibly human health. © 2017 The Author(s).

  1. Food of forage fishes in western Lake Erie, 1975-76

    Science.gov (United States)

    Muth, Kenneth M.; Busch, Wolf-Dieter N.

    1989-01-01

    In western Lake Erie in the summer and fall of 1975–1976, food eaten by seven forage fishes—emerald shiner (Notropis atherinoides), spottail shiner (Notropis hudsonius), trout-perch (Percopsis omiscomaycus), andyoung-of-the-year (YOY) of alewife (Alosa pseudoharengus), gizzard shad (Dorosoma cepedianum), white bass (Morone chrysops), and freshwater drum (Aplodi-notus grunniens)—was divided among six major taxa: Cladocera, Copepoda, Diptera, Ostracoda, Amphipoda, and Algae. In addition, fish were eaten by YOY white bass, and Rotifera were consumed by YOY gizzard shad. Interspecies diet overlap indices, calculated to compare the food of the different species and to evaluate diet similarities, were usually highest for YOY white bass and YOY freshwater drum when compared with the other species and usually lowest between emerald shiners and all other forage fishes. Understanding the feeding interactions among fishes that could influence production at the forage-food level of the food web could provide insight into how cascading trophic interactions influence the production of piscivorous predators.

  2. Emergence and seedling growth of five forage legume species at ...

    African Journals Online (AJOL)

    Jane

    2011-08-17

    Aug 17, 2011 ... A field study compared the seedling emergence and structure of five forage legumes .... mean seed mass (without seed coat) per species was used for W1 ...... Of light and length: regulation of hypocotyl growth in Arabidopsis.

  3. Best practices for assessing forage fish fisheries-seabird resource competition

    Science.gov (United States)

    Sydeman, William J.; Thompson, Sarah Ann; Anker-Nilssen, Tycho; Arimitsu, Mayumi L.; Bennison, Ashley; Bertrand, Sophie; Boersch-Supan, Philipp; Boyd, Charlotte; Bransome, Nicole C.; Crawford, Robert J.M.; Daunt, Francis; Furness, Robert W.; Gianuca, Dimas; Gladics, Amanda; Koehn, Laura; Lang, Jennifer W.; Loggerwell, Elizabeth; Morris, Taryn L.; Phillips, Elizabeth M.; Provencher, Jennifer; Punt, André E..; Saraux, Claire; Shannon, Lynne; Sherley, Richard B.; Simeone, Alejandro; Wanless, Ross M.; Wanless, Sarah; Zador, Stephani

    2017-01-01

    Worldwide, in recent years capture fisheries targeting lower-trophic level forage fish and euphausiid crustaceans have been substantial (∼20 million metric tons [MT] annually). Landings of forage species are projected to increase in the future, and this harvest may affect marine ecosystems and predator-prey interactions by removal or redistribution of biomass central to pelagic food webs. In particular, fisheries targeting forage fish and euphausiids may be in competition with seabirds, likely the most sensitive of marine vertebrates given limitations in their foraging abilities (ambit and gape size) and high metabolic rate, for food resources. Lately, apparent competition between fisheries and seabirds has led to numerous high-profile conflicts over interpretations, as well as the approaches that could and should be used to assess the magnitude and consequences of fisheries-seabird resource competition. In this paper, we review the methods used to date to study fisheries competition with seabirds, and present “best practices” for future resource competition assessments. Documenting current fisheries competition with seabirds generally involves addressing two major issues: 1) are fisheries causing localized prey depletion that is sufficient to affect the birds? (i.e., are fisheries limiting food resources?), and 2) how are fisheries-induced changes to forage stocks affecting seabird populations given the associated functional or numerical response relationships? Previous studies have been hampered by mismatches in the scale of fisheries, fish, and seabird data, and a lack of causal understanding due to confounding by climatic and other ecosystem factors (e.g., removal of predatory fish). Best practices for fisheries-seabird competition research should include i) clear articulation of hypotheses, ii) data collection (or summation) of fisheries, fish, and seabirds on matched spatio-temporal scales, and iii) integration of observational and experimental

  4. Sediment-induced turbidity impairs foraging performance and prey choice of planktivorous coral reef fishes.

    Science.gov (United States)

    Johansen, J L; Jones, G P

    2013-09-01

    Sedimentation is a substantial threat to aquatic ecosystems and a primary cause of habitat degradation on near-shore coral reefs. Although numerous studies have demonstrated major impacts of sedimentation and turbidity on corals, virtually nothing is known of the sensitivity of reef fishes. Planktivorous fishes are an important trophic group that funnels pelagic energy sources into reef ecosystems. These fishes are visual predators whose foraging is likely to be impaired by turbidity, but the threshold for such effects and their magnitude are unknown. This study examined the effect of sediment-induced turbidity on foraging in four species of planktivorous damselfishes (Pomacentridae) of the Great Barrier Reef, including inshore and offshore species that potentially differ in tolerance for turbidity. An experimental flow tunnel was used to quantify their ability to catch mobile and immobile planktonic prey under different levels of turbidity and velocity in the range encountered on natural and disturbed reefs. Turbidity of just 4 NTU (nephelometric turbidity units) reduced average attack success by up to 56%, with higher effect sizes for species with offshore distributions. Only the inshore species (Neopomacentrus bankieri), which frequently encounters this turbidity on coastal reefs, could maintain high prey capture success. At elevated turbidity similar to that found on disturbed reefs (8 NTU), attack success was reduced in all species examined by up to 69%. These reductions in attack success led to a 21-24% decrease in foraging rates for all mid to outer-shelf species, in spite of increasing attack rates at high turbidity. Although effects of turbidity varied among species, it always depended heavily on prey mobility and ambient velocity. Attack success was up to 14 times lower on mobile prey, leaving species relatively incapable of foraging on anything but immobile prey at high turbidity. Effects of turbidity were particularly prominent at higher velocities, as

  5. Positive Interactions among Foraging Seabirds, Marine Mammals and Fishes and Implications for Their Conservation

    Directory of Open Access Journals (Sweden)

    Richard R. Veit

    2017-10-01

    Full Text Available There is increasing recognition of the importance of “positive interactions” among species in structuring communities. For seabirds, an important kind of positive interaction is the use of birds of the same species, birds of other species, and other marine predators such as cetaceans, seals and fishes as cues to the presence of prey. The process by which a single bird uses, say, a feeding flock of birds as a cue to the presence of prey is called “local enhancement” or “facilitation.” There are subtly different uses of each of these terms, but the issue we address here is the ubiquity of positive interactions between seabirds and other marine predators when foraging at sea, and whether as a result of their associations the feeding success, and therefore presumably the fitness, of individual seabirds is increased. If this contention is true, then it implies that conservation of any one species of seabird must take into consideration the status and possible conservation of those species that the focal species uses as a cue while foraging. For example, conservation of great shearwaters (Ardenna gravis, which often feed over tuna (e.g., Thunnus schools, should take in to consideration conservation of tuna. Ecosystem management depends on understanding the importance of such processes; the loss of biodiversity, and the consequent threat to foraging success, may be a substantial threat to the stability of marine ecosystems.

  6. Mercury effects on predator avoidance behavior of a forage fish, golden shiner (Notemigonus crysoleucas)

    Science.gov (United States)

    Webber, H.M.; Haines, T.A.

    2003-01-01

    Mercury contamination of fish is widespread in North America and has resulted in the establishment of fish consumption advisories to protect human health, However, the effects of mercury exposure to fish have seldom been investigated. We examined the effects of dietary mercury exposure at environmental levels in a common forage species, golden shiner (Notemigonus crysoleucas). Fish were fed either an unaltered diet (12 ng/g wet wt methylmercury [MeHg] as Hg), a low-Hg diet (455 ng/g Hg), or a high-Hg diet (959 ng/g Hg). After 90 d mean fish whole-body total Hg concentrations were 41, 230, and 518 ng/g wet wt, respectively, which were within the range of concentrations found in this species in northern U.S. lakes. There were no mortalities or differences in growth rate among groups. Groups of fish from each treatment were exposed to a model avian predator and their behavioral response videotaped for analysis. Brain acetylcholinesterase (AChE) activity was determined in fish after behavioral testing. Fish fed the high-Hg diet had significantly greater shoal vertical dispersal following predator exposure, took longer to return to pre-exposure activity level, and had greater shoal area after return to pre-exposure activity than did the other treatments, all of which would increase vulnerability of the fish to predation. There were no differences in brain AChE among treatments. We conclude that mercury exposure at levels currently occurring in northern United States lakes alters fish predator-avoidance behavior in a manner that may increase vulnerability to predation. This finding has significant implications for food chain transfer of Hg and Hg exposure of fish predators.

  7. Foraging and metabolic consequences of semi-anadromy for an endangered estuarine fish.

    Directory of Open Access Journals (Sweden)

    Bruce G Hammock

    Full Text Available Diadromy affords fish access to productive ecosystems, increasing growth and ultimately fitness, but it is unclear whether these advantages persist for species migrating within highly altered habitat. Here, we compared the foraging success of wild Delta Smelt-an endangered, zooplanktivorous, annual, semi-anadromous fish that is endemic to the highly altered San Francisco Estuary (SFE-collected from freshwater (<0.55 psu and brackish habitat (≥0.55 psu. Stomach fullness, averaged across three generations of wild Delta Smelt sampled from juvenile through adult life stages (n = 1,318, was 1.5-fold higher in brackish than in freshwater habitat. However, salinity and season interacted, with higher fullness (1.7-fold in freshwater than in brackish habitat in summer, but far higher fullness in brackish than freshwater habitat during fall/winter and winter/spring (1.8 and 2.0-fold, respectively. To examine potential causes of this interaction we compared mesozooplankton abundance, collected concurrently with the Delta Smelt, in freshwater and brackish habitat during summer and fall/winter, and the metabolic rate of sub-adult Delta Smelt acclimated to salinities of 0.4, 2.0, and 12.0 psu in a laboratory experiment. A seasonal peak in mesozooplankton density coincided with the summer peak in Delta Smelt foraging success in freshwater, and a pronounced decline in freshwater mesozooplankton abundance in the fall coincided with declining stomach fullness, which persisted for the remainder of the year (fall, winter and spring. In brackish habitat, greater foraging 'efficiency' (prey items in stomachs/mesozooplankton abundance led to more prey items per fish and generally higher stomach fullness (i.e., a higher proportion of mesozooplankton detected in concurrent trawls were eaten by fish in brackish habitat. Delta Smelt exhibited no difference in metabolic rate across the three salinities, indicating that metabolic responses to salinity are unlikely to have

  8. Simulating mechanisms for dispersal, production and stranding of small forage fish in temporary wetland habitats

    Science.gov (United States)

    Yurek, Simeon; DeAngelis, Donald L.; Trexler, Joel C.; Jopp, Fred; Donalson, Douglas D.

    2013-01-01

    Movement strategies of small forage fish (wetland habitats affect their overall population growth and biomass concentrations, i.e., availability to predators. These fish are often the key energy link between primary producers and top predators, such as wading birds, which require high concentrations of stranded fish in accessible depths. Expansion and contraction of seasonal wetlands induce a sequential alternation between rapid biomass growth and concentration, creating the conditions for local stranding of small fish as they move in response to varying water levels. To better understand how landscape topography, hydrology, and fish behavior interact to create high densities of stranded fish, we first simulated population dynamics of small fish, within a dynamic food web, with different traits for movement strategy and growth rate, across an artificial, spatially explicit, heterogeneous, two-dimensional marsh slough landscape, using hydrologic variability as the driver for movement. Model output showed that fish with the highest tendency to invade newly flooded marsh areas built up the largest populations over long time periods with stable hydrologic patterns. A higher probability to become stranded had negative effects on long-term population size, and offset the contribution of that species to stranded biomass. The model was next applied to the topography of a 10 km × 10 km area of Everglades landscape. The details of the topography were highly important in channeling fish movements and creating spatiotemporal patterns of fish movement and stranding. This output provides data that can be compared in the future with observed locations of fish biomass concentrations, or such surrogates as phosphorus ‘hotspots’ in the marsh.

  9. Ecology of selected marine communities in Glacier Bay: Zooplankton, forage fish, seabirds and marine mammals

    Science.gov (United States)

    Robards, Martin D.; Drew, Gary S.; Piatt, John F.; Anson, Jennifer Marie; Abookire, Alisa A.; Bodkin, James L.; Hooge, Philip N.; Speckman, Suzann G.

    2003-01-01

    -Bay.We identified 55 species of fish during this study (1999 and 2000) from beach seines, mid-water trawls, and rod and line catches. The diversity of physical, oceanographic, and glacial chronological conditions within Glacier Bay contribute a suite of factors that influence the distribution and abundance of fish. Accordingly, we observed significant differences in the abundance and distribution of fish within the Bay. Most significantly, abundance and diversity (primarily juvenile fish including walleye Pollock, eelblennies, and capelin) were greatest at the head of both the east and west arms where zooplankton abundance was greatest – in close proximity to tidewater glaciers and freshwater runoff. All of Glacier Bay and Icy Strait were surveyed hydroacoustically for plankton and fish during June 1999 surveys. Acoustically determined forage biomass was concentrated in relatively few important areas such as Pt. Adolphus, Berg Bay, on the Geikie-Scidmore shelf, around the Beardslee/Marble islands, and the upper arms of Glacier Bay. Forage biomass (primarily small schooling fish and euphausiids) was concentrated in shallow, nearshore waters; 50 % of acoustic biomass was found at depths 0.01 fish/m3) for seabirds foraging on zooplankton and small schooling fish. Less than 1 % of the area contained patches suitable (e.g., >0.1 fish/m3) for whales foraging on zooplankton and small schooling fish. High-density aggregations of 0.1-10 fish/m3 were comprised mostly of schools containing capelin, pollock, herring or euphausiids (0.1-1 kg/m3).During predator surveys (1999-2000), we observed 63 species of birds and 7 species of marine mammals. Seasonal distribution and abundance of these “apex” predators was highly variable by species. Glacier Bay supports high numbers of seabirds and marine mammals that consume zooplankton and small schooling fish. Nearshore areas had higher densities of both birds and marine mammals. Several areas, such as Pt. Adolphus, Berg Bay, on the Geikie

  10. Morphology and Efficiency of a Specialized Foraging Behavior, Sediment Sifting, in Neotropical Cichlid Fishes

    Science.gov (United States)

    Willis, Stuart; Watkins, Crystal; Honeycutt, Rodney L.; Winemiller, Kirk O.

    2014-01-01

    Understanding of relationships between morphology and ecological performance can help to reveal how natural selection drives biological diversification. We investigate relationships between feeding behavior, foraging performance and morphology within a diverse group of teleost fishes, and examine the extent to which associations can be explained by evolutionary relatedness. Morphological adaptation associated with sediment sifting was examined using a phylogenetic linear discriminant analysis on a set of ecomorphological traits from 27 species of Neotropical cichlids. For most sifting taxa, feeding behavior could be effectively predicted by a linear discriminant function of ecomorphology across multiple clades of sediment sifters, and this pattern could not be explained by shared evolutionary history alone. Additionally, we tested foraging efficiency in seven Neotropical cichlid species, five of which are specialized benthic feeders with differing head morphology. Efficiency was evaluated based on the degree to which invertebrate prey could be retrieved at different depths of sediment. Feeding performance was compared both with respect to feeding mode and species using a phylogenetic ANCOVA, with substrate depth as a covariate. Benthic foraging performance was constant across sediment depths in non-sifters but declined with depth in sifters. The non-sifting Hypsophrys used sweeping motions of the body and fins to excavate large pits to uncover prey; this tactic was more efficient for consuming deeply buried invertebrates than observed among sediment sifters. Findings indicate that similar feeding performance among sediment-sifting cichlids extracting invertebrate prey from shallow sediment layers reflects constraints associated with functional morphology and, to a lesser extent, phylogeny. PMID:24603485

  11. Morphology and efficiency of a specialized foraging behavior, sediment sifting, in neotropical cichlid fishes.

    Science.gov (United States)

    López-Fernández, Hernán; Arbour, Jessica; Willis, Stuart; Watkins, Crystal; Honeycutt, Rodney L; Winemiller, Kirk O

    2014-01-01

    Understanding of relationships between morphology and ecological performance can help to reveal how natural selection drives biological diversification. We investigate relationships between feeding behavior, foraging performance and morphology within a diverse group of teleost fishes, and examine the extent to which associations can be explained by evolutionary relatedness. Morphological adaptation associated with sediment sifting was examined using a phylogenetic linear discriminant analysis on a set of ecomorphological traits from 27 species of Neotropical cichlids. For most sifting taxa, feeding behavior could be effectively predicted by a linear discriminant function of ecomorphology across multiple clades of sediment sifters, and this pattern could not be explained by shared evolutionary history alone. Additionally, we tested foraging efficiency in seven Neotropical cichlid species, five of which are specialized benthic feeders with differing head morphology. Efficiency was evaluated based on the degree to which invertebrate prey could be retrieved at different depths of sediment. Feeding performance was compared both with respect to feeding mode and species using a phylogenetic ANCOVA, with substrate depth as a covariate. Benthic foraging performance was constant across sediment depths in non-sifters but declined with depth in sifters. The non-sifting Hypsophrys used sweeping motions of the body and fins to excavate large pits to uncover prey; this tactic was more efficient for consuming deeply buried invertebrates than observed among sediment sifters. Findings indicate that similar feeding performance among sediment-sifting cichlids extracting invertebrate prey from shallow sediment layers reflects constraints associated with functional morphology and, to a lesser extent, phylogeny.

  12. Emergent Sandbar Construction for Least Terns on the Missouri River: Effects on Forage Fishes in Shallow-Water Habitats

    Science.gov (United States)

    Stucker, J.H.; Buhl, D.A.; Sherfy, M.H.

    2011-01-01

    Emergent sandbars on the Missouri River are actively managed for two listed bird species, piping plovers and interior least terns. As a plunge-diving piscivore, endangered least terns rely on ready access to appropriately sized slender-bodied fish: nesting habitat for plovers and terns, the U.S. Army Corps of Engineers mechanically created several emergent sandbars on the Missouri River. However, it was unknown whether sandbar construction is a benefit or a detriment to forage abundance for least terns. Therefore, we studied the shallowwater (nesting seasons (2006-2008). We sampled every 2 weeks each year from late May to July within 15-16 areas to document the relative abundance, species richness and size classes of fish. Fish relative abundance was negatively related to depth. Catches were dominated by schooling species, including emerald shiner, sand shiner, spotfin shiner and bigmouth buffalo. Significant inter-annual differences in relative abundance were observed, with generally increasing trends in intra-seasonal relative abundance of shiners and the smallest size classes of fish (<34 mm). Significant differences in the fish communities between the sandbar types were not detected in this study. Results suggest that mechanical sandbar habitats host comparable fish communities at similar levels of relative abundance. Further analyses are required to evaluate if the levels of fish relative abundance are adequate to support least tern foraging and reproduction.

  13. Turtle cleaners: reef fishes foraging on epibionts of sea turtles in the tropical Southwestern Atlantic, with a summary of this association type

    Directory of Open Access Journals (Sweden)

    Cristina Sazima

    Full Text Available In the present study we record several instances of reef fish species foraging on epibionts of sea turtles (cleaning symbiosis at the oceanic islands of Fernando de Noronha Archipelago and near a shipwreck, both off the coast of Pernambuco State, northeast Brazil. Nine reef fish species and three turtle species involved in cleaning are herein recorded. Besides our records, a summary of the literature on this association type is presented. Postures adopted by turtles during the interaction are related to the habits of associated fishes. Feeding associations between fishes and turtles seem a localized, albeit common, phenomenon.

  14. Ecosystem-based management objectives for the North Sea: riding the forage fish rollercoaster

    DEFF Research Database (Denmark)

    Dickey-Collas, Mark; Engelhard, Georg H.; Rindorf, Anna

    2014-01-01

    The North Sea provides a useful model for considering forage fish (FF) within ecosystem-based management as it has a complex assemblage of FF species. This paper is designed to encourage further debate and dialogue between stakeholders about management objectives. Changing the management...... whether maintaining the reserves of prey biomass or a more integral approach of monitoring mortality rates across the trophic system is more robust under the ecosystem approach. In terms of trophic energy transfer, stability, and resilience of the ecosystem, FF should be considered as both a sized-based...... pool of biomass and as species components of the system by managers and modellers. Policy developers should not consider the knowledge base robust enough to embark on major projects of ecosystem engineering. Management plans appear able to maintain sustainable exploitation in the short term. Changes...

  15. Habitat Requirements and Foraging Ecology of the Madagascar Fish-Eagle

    OpenAIRE

    Berkelman, James

    1997-01-01

    With a population estimate of 99 pairs, the Madagascar fish-eagle (Haliaeetus vociferoides) is one of the rarest birds of prey in the world. I investigated the ecological requirements of the Madagascar fish-eagle in 1994 and 1995 to help determine management action to prevent its extinction. I investigated fish-eagle foraging ecology in 1996 to determine its prey preference and whether fish abundance and availabi...

  16. Chemokines in teleost fish species.

    Science.gov (United States)

    Alejo, Alí; Tafalla, Carolina

    2011-12-01

    Chemokines are chemoattractant cytokines defined by the presence of four conserved cysteine residues which in mammals can be divided into four subfamilies depending on the arrangement of the first two conserved cysteines in their sequence: CXC (α), CC (β), C and CX(3)C classes. Evolutionarily, fish can be considered as an intermediate step between species which possess only innate immunity (invertebrates) and species with a fully developed acquired immune network such as mammals. Therefore, the functionality of their different immune cell types and molecules is sometimes also intermediate between innate and acquired responses. The first chemokine gene identified in a teleost was a rainbow trout (Oncorhynchus mykiss) chemokine designated as CK1 in 1998. Since then, many different chemokine genes have been identified in several fish species, but their role in homeostasis and immune response remains largely unknown. Extensive genomic duplication events and the fact that chemokines evolve more quickly than other immune genes, make it very difficult to establish true orthologues between fish and mammalian chemokines that would help us with the ascription of immune roles. In this review, we describe the current state of knowledge of chemokine biology in teleost fish, focusing mainly on which genes have been identified so far and highlighting the most important aspects of their expression regulation, due to the great lack of functional information available for them. As the number of chemokine genes begins to close down for some teleost species, there is an important need for functional assays that may elucidate the role of each of these molecules within the fish immune response. Copyright © 2011 Elsevier Ltd. All rights reserved.

  17. Morphology and efficiency of a specialized foraging behavior, sediment sifting, in neotropical cichlid fishes.

    Directory of Open Access Journals (Sweden)

    Hernán López-Fernández

    Full Text Available Understanding of relationships between morphology and ecological performance can help to reveal how natural selection drives biological diversification. We investigate relationships between feeding behavior, foraging performance and morphology within a diverse group of teleost fishes, and examine the extent to which associations can be explained by evolutionary relatedness. Morphological adaptation associated with sediment sifting was examined using a phylogenetic linear discriminant analysis on a set of ecomorphological traits from 27 species of Neotropical cichlids. For most sifting taxa, feeding behavior could be effectively predicted by a linear discriminant function of ecomorphology across multiple clades of sediment sifters, and this pattern could not be explained by shared evolutionary history alone. Additionally, we tested foraging efficiency in seven Neotropical cichlid species, five of which are specialized benthic feeders with differing head morphology. Efficiency was evaluated based on the degree to which invertebrate prey could be retrieved at different depths of sediment. Feeding performance was compared both with respect to feeding mode and species using a phylogenetic ANCOVA, with substrate depth as a covariate. Benthic foraging performance was constant across sediment depths in non-sifters but declined with depth in sifters. The non-sifting Hypsophrys used sweeping motions of the body and fins to excavate large pits to uncover prey; this tactic was more efficient for consuming deeply buried invertebrates than observed among sediment sifters. Findings indicate that similar feeding performance among sediment-sifting cichlids extracting invertebrate prey from shallow sediment layers reflects constraints associated with functional morphology and, to a lesser extent, phylogeny.

  18. Grey seal predation on forage fish in the Baltic Sea

    DEFF Research Database (Denmark)

    Eero, Aro; Neuenfeldt, Stefan; Aho, Teija

    The mean annual growth rate of grey seal stock in the Baltic has been on average 7.5% annually during the last decade. In 2010, a total of approximately 23 100 grey seals were counted. The increase in stock size was highest in the northern areas and the predation pressure of grey seals on clupeoids...... has increased accordingly. The diet of grey seal in the Baltic consists of ca. 20 fish species. The most abundant prey items in the Baltic proper are Baltic herring, sprat, and cod, and in the Bothnian Sea and Bothnian Bay Baltic herring, Coregonus sp., Baltic salmon, and sea trout. An adult seal...... consumes on average round 4.5 kg fish per day, of which 55% are clupeoids in the Baltic Main basin and 70% in the Bothnian Sea and Bothnian Bay. According to acoustic estimates, predator– prey distribution patterns, migration patterns, and multispecies analysis (SMS), the predation effect of grey seals...

  19. Terrestrial and Marine Foraging Strategies of an Opportunistic Seabird Species Breeding in the Wadden Sea.

    Directory of Open Access Journals (Sweden)

    Stefan Garthe

    Full Text Available Lesser black-backed gulls Larus fuscus are considered to be mainly pelagic. We assessed the importance of different landscape elements (open sea, tidal flats and inland by comparing marine and terrestrial foraging behaviours in lesser black-backed gulls breeding along the coast of the southern North Sea. We attached GPS data loggers to eight incubating birds and collected information on diet and habitat use. The loggers recorded data for 10-19 days to allow flight-path reconstruction. Lesser black-backed gulls foraged in both offshore and inland areas, but rarely on tidal flats. Targets and directions were similar among all eight individuals. Foraging trips (n = 108 lasted 0.5-26.4 h (mean 8.7 h, and ranges varied from 3.0-79.9 km (mean 30.9 km. The total distance travelled per foraging trip ranged from 7.5-333.6 km (mean 97.9 km. Trips out to sea were significantly more variable in all parameters than inland trips. Presence in inland areas was closely associated with daylight, whereas trips to sea occurred at day and night, but mostly at night. The most common items in pellets were grass (48%, insects (38%, fish (28%, litter (26% and earthworms (20%. There was a significant relationship between the carbon and nitrogen isotope signals in blood and the proportional time each individual spent foraging at sea/land. On land, gulls preferentially foraged on bare ground, with significantly higher use of potato fields and significantly less use of grassland. The flight patterns of lesser black-backed gulls at sea overlapped with fishing-vessel distribution, including small beam trawlers fishing for shrimps in coastal waters close to the colony and large beam-trawlers fishing for flatfish at greater distances. Our data show that individuals made intensive use of the anthropogenic landscape and seascape, indicating that lesser black-backed gulls are not a predominantly marine species during the incubation period.

  20. Oceanographic conditions structure forage fishes into lipid-rich and lipid-poor communities in lower Cook Inlet, Alaska, USA

    Science.gov (United States)

    Abookire, Alisa A.; Piatt, John F.

    2005-01-01

    Forage fishes were sampled with a mid-water trawl in lower Cook Inlet, Alaska, USA, from late July to early August 1996 to 1999. We sampled 3 oceanographically distinct areas of lower Cook Inlet: waters adjacent to Chisik Island, in Kachemak Bay, and near the Barren Islands. In 163 tows using a mid-water trawl, 229 437 fishes with fork length lipid-poor gadids (walleye pollock and Pacific cod), and significantly increased in lipid-rich species such as Pacific sand lance, Pacific herring, and capelin. ?? Inter-Research 2005.

  1. A day in the life of fish larvae: modeling foraging and growth using quirks.

    Directory of Open Access Journals (Sweden)

    Klaus B Huebert

    Full Text Available This article introduces "Quirks," a generic, individual-based model synthesizing over 40 years of empirical and theoretical insights into the foraging behavior and growth physiology of marine fish larvae. In Quirks, different types of larvae are defined by a short list of their biological traits, and all foraging and growth processes (including the effects of key environmental factors are modeled following one unified set of mechanistic rules. This approach facilitates ecologically meaningful comparisons between different species and environments. We applied Quirks to model young exogenously feeding larvae of four species: 5.5-mm European anchovy (Engraulis encrasicolus, 7-mm Atlantic cod (Gadus morhua, 13-mm Atlantic herring (Clupea harengus, and 7-mm European sprat (Sprattus sprattus. Modeled growth estimates explained the majority of variability among 53 published empirical growth estimates, and displayed very little bias: 0.65% ± 1.2% d(-1 (mean ± standard error. Prey organisms of ∼ 67% the maximum ingestible prey length were optimal for all larval types, in terms of the expected ingestion per encounter. Nevertheless, the foraging rate integrated over all favorable prey sizes was highest when smaller organisms made up >95% of the prey biomass under the assumption of constant normalized size spectrum slopes. The overall effect of turbulence was consistently negative, because its detrimental influence on prey pursuit success exceeded its beneficial influence on prey encounter rate. Model sensitivity to endogenous traits and exogenous environmental factors was measured and is discussed in depth. Quirks is free software and open source code is provided.

  2. Fish with red fluorescent eyes forage more efficiently under dim, blue-green light conditions.

    Science.gov (United States)

    Harant, Ulrike Katharina; Michiels, Nicolaas Karel

    2017-04-20

    Natural red fluorescence is particularly conspicuous in the eyes of some small, benthic, predatory fishes. Fluorescence also increases in relative efficiency with increasing depth, which has generated speculation about its possible function as a "light organ" to detect cryptic organisms under bluish light. Here we investigate whether foraging success is improved under ambient conditions that make red fluorescence stand out more, using the triplefin Tripterygion delaisi as a model system. We repeatedly presented 10 copepods to individual fish (n = 40) kept under a narrow blue-green spectrum and compared their performance with that under a broad spectrum with the same overall brightness. The experiment was repeated for two levels of brightness, a shaded one representing 0.4% of the light present at the surface and a heavily shaded one with about 0.01% of the surface brightness. Fish were 7% more successful at catching copepods under the narrow, fluorescence-friendly spectrum than under the broad spectrum. However, this effect was significant under the heavily shaded light treatment only. This outcome corroborates previous predictions that fluorescence may be an adaptation to blue-green, heavily shaded environments, which coincides with the opportunistic biology of this species that lives in the transition zone between exposed and heavily shaded microhabitats.

  3. Fishing down the largest coral reef fish species.

    Science.gov (United States)

    Fenner, Douglas

    2014-07-15

    Studies on remote, uninhabited, near-pristine reefs have revealed surprisingly large populations of large reef fish. Locations such as the northwestern Hawaiian Islands, northern Marianas Islands, Line Islands, U.S. remote Pacific Islands, Cocos-Keeling Atoll and Chagos archipelago have much higher reef fish biomass than islands and reefs near people. Much of the high biomass of most remote reef fish communities lies in the largest species, such as sharks, bumphead parrots, giant trevally, and humphead wrasse. Some, such as sharks and giant trevally, are apex predators, but others such as bumphead parrots and humphead wrasse, are not. At many locations, decreases in large reef fish species have been attributed to fishing. Fishing is well known to remove the largest fish first, and a quantitative measure of vulnerability to fishing indicates that large reef fish species are much more vulnerable to fishing than small fish. The removal of large reef fish by fishing parallels the extinction of terrestrial megafauna by early humans. However large reef fish have great value for various ecological roles and for reef tourism. Copyright © 2014 Elsevier Ltd. All rights reserved.

  4. Foraging

    NARCIS (Netherlands)

    Ydenberg, R.C.; Prins, H.H.T.

    2012-01-01

    This chapter describes the role played by behavioural adjustments to foraging behaviour in accommodating rapid environmental change. It looks into the adjustments of foraging behaviour to predation danger as a result of changes in the type and array of food available. It investigates the effects of

  5. Shifts in North Sea forage fish productivity and potential fisheries yield

    DEFF Research Database (Denmark)

    Worsøe Clausen, Lotte; Rindorf, Anna; van Deurs, Mikael

    2018-01-01

    productivity. Furthermore, from an ecosystem-based fisheries management perspective, a link between functional complementarity and productivity, indicates that ecosystem resilience may decline with productivity. Based on this, we advise that system productivity, perhaps monitored as forage fish growth, becomes......1. Forage fish populations support large scale fisheries and are key components of marine ecosystems across the world, linking secondary production to higher trophic levels. While climate-induced changes in the North Sea zooplankton community are described and documented in literature......, the associated bottom-up effects and consequences for fisheries remain largely unidentified. 2. We investigated the temporal development in forage fish productivity and the associated influence on fisheries yield of herring, sprat, Norway pout and sandeel in the North Sea. Using principal component analysis, we...

  6. The global susceptibility of coastal forage fish to competition by large jellyfish

    DEFF Research Database (Denmark)

    Schnedler-Meyer, Nicolas Azaña; Mariani, Patrizio; Kiørboe, Thomas

    2016-01-01

    dominance at low primary production, and a shift towards jellyfish with increasing productivity, turbidity and fishing. We present an index of global ecosystem susceptibility to shifts in fish–jellyfish dominance that compares well with data on jellyfish distributions and trends. The results are a step......Competition between large jellyfish and forage fish for zooplankton prey is both a possible cause of jellyfish increases and a concern for the management of marine ecosystems and fisheries. Identifying principal factors affecting this competition is therefore important for marine management......, but the lack of both good quality data and a robust theoretical framework have prevented general global analyses. Here, we present a general mechanistic food web model that considers fundamental differences in feeding modes and predation pressure between fish and jellyfish. The model predicts forage fish...

  7. Impacts of species introductions on the health of fish communities receiving chronic radionuclide exposures

    International Nuclear Information System (INIS)

    Yankovich, T.L.; Casselman, J.M.; Cornett, R.J.J.

    2006-01-01

    A study was conducted to evaluate the potential impacts of a northern pike introduction on the health of a fish community receiving chronic radionuclide exposure, primarily from 90 Sr. Overall, although significant changes occurred in the community composition and the health of fish populations following the pike introduction, these were not linked to radionuclide dose to fishes. This finding was further supported by assessing the health of forage fishes, which did not significantly change in the pre-versus post-pike fish communities and were comparable in condition to forage fishes inhabiting lakes with background radionuclide levels. Application of such resilient species as 'baseline organisms' can provide a useful tool in the routine monitoring of ecosystems affected by multiple stressors. (author)

  8. Variations of thiaminase I activity pH dependencies among typical Great Lakes forage fish and Paenibacillus thiaminolyticus.

    Science.gov (United States)

    Zajicek, J.L.; Brown, L.; Brown, S.B.; Honeyfield, D.C.; Fitzsimons, J.D.; Tillitt, D.E.

    2009-01-01

    The source of thiaminase in the Great Lakes food web remains unknown. Biochemical characterization of the thiaminase I activities observed in forage fish was undertaken to provide insights into potential thiaminase sources and to optimize catalytic assay conditions. We measured the thiaminase I activities of crude extracts from five forage fish species and one strain of Paenibacillus thiaminolyticus over a range of pH values. The clupeids, alewife Alosa pseudoharengus and gizzard shad Dorosoma cepedianum, had very similar thiaminase I pH dependencies, with optimal activity ranges (> or = 90% of maximum activity) between pH 4.6 and 5.5. Rainbow smelt Osmerus mordax and spottail shiner Notropis hudsonius had optimal activity ranges between pH 5.5-6.6. The thiaminase I activity pH dependence profile of P. thiaminolyticus had an optimal activity range between pH 5.4 and 6.3, which was similar to the optimal range for rainbow smelt and spottail shiners. Incubation of P. thiaminolyticus extracts with extracts from bloater Coregonus hoyi (normally, bloaters have little or no detectable thiaminase I activity) did not significantly alter the pH dependence profile of P. thiaminolyticus-derived thiaminase I, such that it continued to resemble that of the rainbow smelt and spottail shiner, with an apparent optimal activity range between pH 5.7 and 6.6. These data are consistent with the hypothesis of a bacterial source for thiaminase I in the nonclupeid species of forage fish; however, the data also suggest different sources of thiaminase I enzymes in the clupeid species.

  9. A stochastic differential equation model for the foraging behavior of fish schools.

    Science.gov (United States)

    Tạ, Tôn Việt; Nguyen, Linh Thi Hoai

    2018-03-15

    Constructing models of living organisms locating food sources has important implications for understanding animal behavior and for the development of distribution technologies. This paper presents a novel simple model of stochastic differential equations for the foraging behavior of fish schools in a space including obstacles. The model is studied numerically. Three configurations of space with various food locations are considered. In the first configuration, fish swim in free but limited space. All individuals can find food with large probability while keeping their school structure. In the second and third configurations, they move in limited space with one and two obstacles, respectively. Our results reveal that the probability of foraging success is highest in the first configuration, and smallest in the third one. Furthermore, when school size increases up to an optimal value, the probability of foraging success tends to increase. When it exceeds an optimal value, the probability tends to decrease. The results agree with experimental observations.

  10. A stochastic differential equation model for the foraging behavior of fish schools

    Science.gov (United States)

    Tạ, Tôn ệt, Vi; Hoai Nguyen, Linh Thi

    2018-05-01

    Constructing models of living organisms locating food sources has important implications for understanding animal behavior and for the development of distribution technologies. This paper presents a novel simple model of stochastic differential equations for the foraging behavior of fish schools in a space including obstacles. The model is studied numerically. Three configurations of space with various food locations are considered. In the first configuration, fish swim in free but limited space. All individuals can find food with large probability while keeping their school structure. In the second and third configurations, they move in limited space with one and two obstacles, respectively. Our results reveal that the probability of foraging success is highest in the first configuration, and smallest in the third one. Furthermore, when school size increases up to an optimal value, the probability of foraging success tends to increase. When it exceeds an optimal value, the probability tends to decrease. The results agree with experimental observations.

  11. Shifts in North Sea forage fish productivity and potential fisheries yield

    NARCIS (Netherlands)

    Clausen, Lotte W.; Rindorf, Anna; Deurs, van Mikael; Dickey-Collas, Mark; Hintzen, Niels T.

    2018-01-01

    1. Forage fish populations support large scale fisheries and are key components of marine ecosystems across the world, linking secondary production to higher trophic levels. While climate-induced changes in the North Sea zooplankton community are described and documented in literature, the

  12. Persistence of forage fish ‘hot spots’ and its association with foraging Steller sea lions (Eumetopias jubatus) in southeast Alaska

    Science.gov (United States)

    Gende, Scott M.; Sigler, Michael F.

    2006-02-01

    Whereas primary and secondary productivity at oceanic 'hotspots' may be a function of upwelling and temperature fronts, the aggregation of higher-order vertebrates is a function of their ability to search for and locate these areas. Thus, understanding how predators aggregate at these productive foraging areas is germane to the study of oceanic hot spots. We examined the spatial distribution of forage fish in southeast Alaska for three years to better understand Steller sea lion ( Eumetopias jubatus) aggregations and foraging behavior. Energy densities (millions KJ/km 2) of forage fish were orders of magnitude greater during the winter months (November-February), due to the presence of schools of overwintering Pacific herring ( Clupea pallasi). Within the winter months, herring consistently aggregated at a few areas, and these areas persisted throughout the season and among years. Thus, our study area was characterized by seasonally variable, highly abundant but highly patchily distributed forage fish hot spots. More importantly, the persistence of these forage fish hot spots was an important characteristic in determining whether foraging sea lions utilized them. Over 40% of the variation in the distribution of sea lions on our surveys was explained by the persistence of forage fish hot spots. Using a simple spatial model, we demonstrate that when the density of these hot spots is low, effort necessary to locate these spots is minimized when those spots persist through time. In contrast, under similar prey densities but lower persistence, effort increases dramatically. Thus an important characteristic of pelagic hot spots is their persistence, allowing predators to predict their locations and concentrate search efforts accordingly.

  13. Fisheries oceanography of northern pelagic fish species

    DEFF Research Database (Denmark)

    Tsoukali, Stavroula

    for marine organisms. One of the impacts will be the time that species start to spawn, and there is already evidence for earlier spawning in some North Sea fish species. A change like that may likely have a chain reaction, affecting larval stages and whether they will live in environments with high food...... of the species they consume now and increased availability of new species. In addition, there will likely be economic impacts on the local fishing communities. How species respond to climate change is a field of research that receives great attention because the responses will affect the management of fisheries......People are familiar with marine fish species and the great variety of different species that are available in the market, such as herring, cod and sole. What may not be well known is that every individual fish goes through a long, risky journey during its life before reaching maturity. Most...

  14. A foraging cost of migration for a partially migratory cyprinid fish

    DEFF Research Database (Denmark)

    Chapman, Ben B; Eriksen, Anders; Baktoft, Henrik

    2013-01-01

    Rutilus rutilus, which migrates from shallow lakes to streams during winter. By sampling fish from stream and lake habitats in the autumn and spring and measuring their stomach fullness and diet composition, we tested if migrating roach pay a cost of reduced foraging when migrating. Resident fish had...... fuller stomachs containing more high quality prey items than migrant fish. Hence, we document a feeding cost to migration in roach, which adds additional support for the validity of the p/g model of migration in freshwater systems....

  15. Foraging intention affects whether willow tits call to attract members of mixed-species flocks.

    Science.gov (United States)

    Suzuki, Toshitaka N; Kutsukake, Nobuyuki

    2017-06-01

    Understanding how individual behaviour influences the spatial and temporal distribution of other species is necessary to resolve the complex structure of species assemblages. Mixed-species bird flocks provide an ideal opportunity to investigate this issue, because members of the flocks are involved in a variety of behavioural interactions between species. Willow tits ( Poecile montanus ) often produce loud calls when visiting a new foraging patch to recruit other members of mixed-species flocks. The costs and benefits of flocking would differ with individual foraging behaviours (i.e. immediate consumption or caching); thus, willow tits may adjust the production of loud calls according to their foraging intention. In this study, we investigated the link between foraging decisions and calling behaviour in willow tits and tested its influence on the temporal cohesion with members of mixed-species flocks. Observations at experimental foraging patches showed that willow tits produced more calls when they consumed food items compared with when they cached them. Playback experiments revealed that these calls attracted flock members and helped to maintain their presence at foraging patches. Thus, willow tits adjusted calling behaviour according to their foraging intention, thereby coordinating the associations with members of mixed-species flocks. Our findings demonstrate the influence of individual decision-making on temporal cohesion with other species and highlight the importance of interspecific communication in mixed-species flocking dynamics.

  16. Quorum decision-making in foraging fish shoals.

    Directory of Open Access Journals (Sweden)

    Ashley J W Ward

    Full Text Available Quorum responses provide a means for group-living animals to integrate and filter disparate social information to produce accurate and coherent group decisions. A quorum response may be defined as a steep increase in the probability of group members performing a given behaviour once a threshold minimum number of their group mates already performing that behaviour is exceeded. In a previous study we reported the use of a quorum response in group decision-making of threespine sticklebacks (Gasterosteus aculeatus under a simulated predation threat. Here we examine the use of quorum responses by shoals of sticklebacks in first locating and then leaving a foraging patch. We show that a quorum rule explains movement decisions by threespine sticklebacks toward and then away from a food patch. Following both to and from a food patch occurred when a threshold number of initiators was exceeded, with the threshold being determined by the group size.

  17. A new approach to study of seabird-fishery overlap: Connecting chick feeding with parental foraging and overlap with fishing vessels

    Directory of Open Access Journals (Sweden)

    Junichi Sugishita

    2015-07-01

    Full Text Available Incidental fisheries bycatch is recognised as a major threat to albatross populations worldwide. However, fishery discards and offal produced in large quantities might benefit some scavenging seabirds. Here, we demonstrate an integrated approach to better understand the ecological ramifications of fine-scale overlap between seabirds and fisheries. As a case study, we examined whether foraging in association with a fishing vessel is advantageous for chick provisioning in terms of quantity of food delivered to chicks, in northern royal albatross (Diomedea sanfordi at Taiaroa Head, New Zealand. Fine-scale overlap between albatrosses and vessels was quantified by integrating GPS tracking and Vessel Monitoring Systems (VMS. Meal size delivered to chicks was measured using custom-designed nest balances, and monitoring of attendance of adults fitted with radio transmitters was used in conjunction with time-lapse photography at the nest allowed us to allocate each feeding event to a specific parent. The combination of these techniques enabled comparison of meal sizes delivered to chicks with parental foraging trip durations with or without fishing vessels association. A total of 45 foraging trips and associated chick feeding events were monitored during the chick-rearing period in 2012. Differences in the meal size and foraging trip duration relative to foraging overlap with fisheries were examined using a linear mixed-effect model, adjusted for chick age. Our results, based on three birds, suggest that foraging in association with vessels does not confer an advantage for chick feeding for this population that demonstrated low rates of overlap while foraging. The integrated research design presented can be applied to other seabird species that are susceptible to bycatch, and offers a valuable approach to evaluate habitat quality by linking habitat use and foraging success in terms of total amount of food delivered to offspring.

  18. Invasive clonal plant species have a greater root-foraging plasticity than non-invasive ones.

    Science.gov (United States)

    Keser, Lidewij H; Dawson, Wayne; Song, Yao-Bin; Yu, Fei-Hai; Fischer, Markus; Dong, Ming; van Kleunen, Mark

    2014-03-01

    Clonality is frequently positively correlated with plant invasiveness, but which aspects of clonality make some clonal species more invasive than others is not known. Due to their spreading growth form, clonal plants are likely to experience spatial heterogeneity in nutrient availability. Plasticity in allocation of biomass to clonal growth organs and roots may allow these plants to forage for high-nutrient patches. We investigated whether this foraging response is stronger in species that have become invasive than in species that have not. We used six confamilial pairs of native European clonal plant species differing in invasion success in the USA. We grew all species in large pots under homogeneous or heterogeneous nutrient conditions in a greenhouse, and compared their nutrient-foraging response and performance. Neither invasive nor non-invasive species showed significant foraging responses to heterogeneity in clonal growth organ biomass or in aboveground biomass of clonal offspring. Invasive species had, however, a greater positive foraging response in terms of root and belowground biomass than non-invasive species. Invasive species also produced more total biomass. Our results suggest that the ability for strong root foraging is among the characteristics promoting invasiveness in clonal plants.

  19. Effects of habitat composition and landscape structure on worker foraging distances of five bumble bee species.

    Science.gov (United States)

    Redhead, John W; Dreier, Stephanie; Bourke, Andrew F G; Heard, Matthew S; Jordan, William C; Sumner, Seirian; Wang, Jinliang; Carvell, Claire

    2016-04-01

    Bumble bees (Bombus spp.) are important pollinators of both crops and wildflowers. Their contribution to this essential ecosystem service has been threatened over recent decades by changes in land use, which have led to declines in their populations. In order to design effective conservation measures, it is important to understand the effects of variation in landscape composition and structure on the foraging activities of worker bumble bees. This is because the viability of individual colonies is likely to be affected by the trade-off between the energetic costs of foraging over greater distances and the potential gains from access to additional resources. We used field surveys, molecular genetics, and fine resolution remote sensing to estimate the locations of wild bumble bee nests and to infer foraging distances across a 20-km² agricultural landscape in southern England, UK. We investigated five species, including the rare B. ruderatus and ecologically similar but widespread B. hortorum. We compared worker foraging distances between species and examined how variation in landscape composition and structure affected foraging distances at the colony level. Mean worker foraging distances differed significantly between species. Bombus terrestris, B. lapidarius, and B. ruderatus exhibited significantly greater mean foraging distances (551, 536, and 501 m, respectively) than B. hortorum and B. pascuorum (336 and 272 m, respectively). There was wide variation in worker foraging distances between colonies of the same species, which was in turn strongly influenced by the amount and spatial configuration of available foraging habitats. Shorter foraging distances were found for colonies where the local landscape had high coverage and low fragmentation of semi-natural vegetation, including managed agri-environmental field margins. The strength of relationships between different landscape variables and foraging distance varied between species, for example the strongest

  20. Impacts of species introductions on the health of fish communities receiving chronic radionuclide inputs

    International Nuclear Information System (INIS)

    Yankovich, T.L.; Casselman, J.M.; Cornett, R.J.J.

    2004-01-01

    There is widespread interest in gaining further understanding of the relative influences of multiple stressors on aquatic ecosystem structure and function. To address this, work has been done to evaluate the effects of the introduction of an efficient predator (northern pike) on a fish community in a small lake (Perch Lake, Chalk River, Ontario) receiving chronic inputs of radionuclides over a 50-year period. In general, large changes in fish community structure, with corresponding changes in fish health, occurred following the pike introduction. For example, several forage fish species were extirpated from the lake and densities of the past top predator, yellow perch, became greatly reduced, likely due to predation by northern pike and/or other species in the lake. The reduced perch numbers appeared to alleviate an ecological bottleneck, which resulted in significant increases in brown bullhead densities to levels that were much higher than observed in other water bodies under typical conditions. Corresponding changes in the health of the Perch Lake fish community could also be detected, and included decreased fish diversity, shifts in fish community size structure to smaller body sizes, significant reductions in fish condition factors, reduced hepato-somatic indices, depletion of fish internal fat reserves, hardening of the gastrointestinal tract, resorption of gonadal material, degradation of muscle tissue, emaciation and ultimately, mortality of northern pike and brown bullheads. Evaluation of data indicated that female fishes responded more quickly than did males in terms of condition loss, likely due to their higher energetic requirements. In addition, although pike and bullheads were detrimentally affected by the pike introduction, health of forage fish species, such as pumpkinseeds, did not appear to be greatly influenced. No clear relationships existed between fish community health and exposure to radionuclides in the lake. (author)

  1. Exploring the nature of ecological specialization in a coral reef fish community: morphology, diet and foraging microhabitat use.

    Science.gov (United States)

    Brandl, Simon J; Robbins, William D; Bellwood, David R

    2015-09-22

    Patterns of ecological specialization offer invaluable information about ecosystems. Yet, specialization is rarely quantified across several ecological niche axes and variables beyond the link between morphological and dietary specialization have received little attention. Here, we provide a quantitative evaluation of ecological specialization in a coral reef fish assemblage (f. Acanthuridae) along one fundamental and two realized niche axes. Specifically, we examined ecological specialization in 10 surgeonfish species with regards to morphology and two realized niche axes associated with diet and foraging microhabitat utilization using a recently developed multidimensional framework. We then investigated the potential relationships between morphological and behavioural specialization. These relationships differed markedly from the traditional ecomorphological paradigm. While morphological specialization showed no relationship with dietary specialization, it exhibited a strong relationship with foraging microhabitat specialization. However, this relationship was inverted: species with specialized morphologies were microhabitat generalists, whereas generalized morphotypes were microhabitat specialists. Interestingly, this mirrors relationships found in plant-pollinator communities and may also be applicable to other ecosystems, highlighting the potential importance of including niche axes beyond dietary specialization into ecomorphological frameworks. On coral reefs, it appears that morphotypes commonly perceived as most generalized may, in fact, be specialized in exploiting flat and easily accessible microhabitats. © 2015 The Author(s).

  2. Spatial management of marine resources can enhance the recovery of predators and avoid local depletion of forage fish

    DEFF Research Database (Denmark)

    Eero, Margit; Vinther, Morten; Haslob, Holger

    2012-01-01

    fish, i.e., sprat and herring, is historic low in this area, which in combination with increasing cod stock results in locally high predation mortality of forage fish and cannibalism of cod. In line with low prey availability, body weight and nutritional condition of cod drastically declined...... management to enhance the recovery of predator stocks...

  3. Study the Seasonal Variability of Plankton and Forage Fish in the Gulf of Khambhat Using Npzfd Model

    Science.gov (United States)

    Kumar, V.; Kumar, S.

    2016-02-01

    Numerical modelling of marine ecology exploits several assumptions and it is indeed quite challenging to include marine ecological phenomena into a mathematical framework with too many unknown parameters. The governing ordinary differential equations represent the interaction of the biological and chemical processes in a marine environment. The key concern in the development of a numerical models are parameterizations based on output, viz., mathematical modelling of ecological system mainly depends on parameters and its variations. Almost, all constituents of each trophic level of marine food web are depended on phytoplankton, which are mostly influenced by initial slope of P-I curve and nutrient stock in the study domain. Whereas, the earlier plankton dynamic models rarely include a compartment of small fish and as an agent in zooplankton mortality, which is most important for the modelling of higher trophic level of marine species. A compartment of forage fish in the modelling of plankton dynamics has been given more realistic mortality rates of plankton, viz., they feed upon phytoplankton and zooplankton. The inclusion of an additional compartment increases complexity of earlier plankton dynamics model as it introduces additional unknown parameters, which has been specified for performing the numerical simulations.As a case study we applied our analysis to explain the aquatic ecology of Gulf of Khambhat (19o 48' N - 22o20' N, 65o E - 72o40' E), west coast of India, which has rich bio-diversity and a high productive area in the form of plankton and forage fish. It has elevated turbidity and varying geography location, viz., one of the regions among world's ocean with high biological productivity.The model presented in this study is able to bring out the essential features of the observed data; that includes the bimodal oscillations in the observed data, monthly mean chlorophyll-a in the SeaWiFs/MODIS Aqua data and in-situ data of plankton. The additional

  4. Group foraging increases foraging efficiency in a piscivorous diver, the African penguin

    Science.gov (United States)

    McGeorge, Cuan; Ginsberg, Samuel; Pichegru, Lorien; Pistorius, Pierre A.

    2017-01-01

    Marine piscivores have evolved a variety of morphological and behavioural adaptations, including group foraging, to optimize foraging efficiency when targeting shoaling fish. For penguins that are known to associate at sea and feed on these prey resources, there is nonetheless a lack of empirical evidence to support improved foraging efficiency when foraging with conspecifics. We examined the hunting strategies and foraging performance of breeding African penguins equipped with animal-borne video recorders. Individuals pursued both solitary as well as schooling pelagic fish, and demonstrated independent as well as group foraging behaviour. The most profitable foraging involved herding of fish schools upwards during the ascent phase of a dive where most catches constituted depolarized fish. Catch-per-unit-effort was significantly improved when targeting fish schools as opposed to single fish, especially when foraging in groups. In contrast to more generalist penguin species, African penguins appear to have evolved specialist hunting strategies closely linked to their primary reliance on schooling pelagic fish. The specialist nature of the observed hunting strategies further limits the survival potential of this species if Allee effects reduce group size-related foraging efficiency. This is likely to be exacerbated by diminishing fish stocks due to resource competition and environmental change. PMID:28989785

  5. Parasites of forage fishes in the vicinity of Steller sea lion (Eumetopias jubatus) habitat in Alaska.

    Science.gov (United States)

    Moles, A; Heintz, R A

    2007-07-01

    Fish serve as intermediate hosts for a number of larval parasites that have the potential of maturing in marine mammals such as Steller sea lions (Eumetopias jubatus). We examined the prevalence of parasites from 229 fish collected between March and July 2002 near two islands used by Steller sea lions in Southeast Alaska and island habitats in the Aleutian Islands. Sea lion populations have remained steady in Southeast Alaska but have been declining over the last 30 yr in the Aleutian Islands. Even though the fish samples near the Southeast Alaska haul-outs were composed of numerous small species of fish and the Aleutian Islands catch was dominated by juveniles of commercially harvested species, the parasite fauna was similar at all locations. Eleven of the 20 parasite taxa identified were in their larval stage in the fish hosts, several of which have been described from mammalian final hosts. Four species of parasite were more prevalent in Southeast Alaska fish samples, and seven parasite species, including several larval forms capable of infecting marine mammals, were more prevalent in fish from the Aleutian Islands. Nevertheless, parasites available to Steller sea lions from common fish prey are not likely to be a major factor in the decline of this marine mammal species.

  6. Sensory quality criteria for five fish species

    DEFF Research Database (Denmark)

    Warm, Karin; Nielsen, Jette; Hyldig, Grethe

    2000-01-01

    Sensory profiling has been used to develop one sensory vocabulary for five fish species: cod (Gadus morhua), saithe (Pollachius virens), rainbow trout (Salmo gardineri), herring (Clupea harengus) and flounder (Platichthys flessus). A nine- member trained panel assessed 18 samples with variation i...... variation and by presenting references, panel discussions and interpreting plots from multivariate data analysis. The developed profile can be used as a sensory wheel for these species, and with minor changes it may be adapted to similar species......Sensory profiling has been used to develop one sensory vocabulary for five fish species: cod (Gadus morhua), saithe (Pollachius virens), rainbow trout (Salmo gardineri), herring (Clupea harengus) and flounder (Platichthys flessus). A nine- member trained panel assessed 18 samples with variation...

  7. Humans are one of several users of forage fish re- sources. Others ...

    African Journals Online (AJOL)

    and Dyer 1995), fish species that also contribute the bulk of the ... layed sexual maturity, that act to buffer their popula- .... The Act took cognizance of several international ..... seals displace endangered, endemic seabirds off Namibia. Biol.

  8. Apparent foraging success reflects habitat quality in an irruptive species, the Black-backed Woodpecker

    Science.gov (United States)

    Christopher T. Rota; Mark A. Rumble; Chad P. Lehman; Dylan C. Kesler; Joshua J. Millspaugh

    2015-01-01

    Dramatic fluctuations in food resources are a key feature of many habitats, and many species have evolved a movement strategy to exploit food resources that are unpredictable in space and time. The availability of food resources may be a particularly strong determinant of habitat quality for irruptive bird species. We studied the apparent foraging success of Black-...

  9. Composition and foraging behaviour of mixed-species flocks in two ...

    African Journals Online (AJOL)

    Enlarged flock size resulted from a general increase in flocking tendency of all species. At the species level, the Long-billed Crombec Sylvietta rufescens and the Chinspot Batis Batis molitor showed clear feeding benefits within flocks, whereas tits obtained no feeding benefit. Crombecs and batises also changed foraging ...

  10. Quality of the forage apparently consumed by beef calves in natural grassland under fertilization and oversown with cool season forage species

    Directory of Open Access Journals (Sweden)

    Denise Adelaide Gomes Elejalde

    2012-06-01

    Full Text Available The objective of this study was to evaluate the chemical composition of the forage apparently consumed by steers in a natural grassland on region of Campanha, in Rio Grande do Sul, Brazil, subjected or not to different inputs: NP - natural pasture without inputs; FNP - fertilized natural pasture and INP - improved natural grassland with fertilization and over-seeded with cultivated winter species. Three Angus steers testers and a variable number of regulator animals per experimental unit were utilized in order to maintain 13 kg of DM/100 kg of live weight (LW as forage allowance. One time at each season, hand plucking samples were performed along the daily grazing time simulating forage harvested by the animals. The collected samples after drying and grind were submitted to chemical analysis to determine the forage quality. Except in winter and spring, the values of neutral detergent fiber were higher than the critical value of 550 g/kg of DM, which could limit forage intake, demonstrating that the values of forage on offer provided (15.6; 13.7; 13.5; 15.8 kg of DM/100 kg of LW/day in summer, autumn, winter and spring, respectively were not restrictive to intake. The oversowing of winter cultivated species or fertilization positively alter the degradable fiber content. The seasons had marked influence on the chemical composition of forage apparently consumed; positively increasing some fractions of forage chemical composition in the seasons in which native or cultivated winter species increased their participation. The forage chemical composition is the determining factor in animal performance in natural pasture.

  11. Bird species of Mouau with special emphasis on foraging behavior ...

    African Journals Online (AJOL)

    Ten different bird species were peculiar to the Umudike environment and of these eight were regular thus closely observed and identified. The other two species were scarcely available and may be regarded as visiting birds. The eight species identified were either Passerine or Non-Passerine. The northern grey-headed ...

  12. Individual diet variation in a marine fish assemblage: Optimal Foraging Theory, Niche Variation Hypothesis and functional identity

    Science.gov (United States)

    Cachera, M.; Ernande, B.; Villanueva, M. C.; Lefebvre, S.

    2017-02-01

    Individual diet variation (i.e. diet variation among individuals) impacts intra- and inter-specific interactions. Investigating its sources and relationship with species trophic niche organization is important for understanding community structure and dynamics. Individual diet variation may increase with intra-specific phenotypic (or "individual state") variation and habitat variability, according to Optimal Foraging Theory (OFT), and with species trophic niche width, according to the Niche Variation Hypothesis (NVH). OFT proposes "proximate sources" of individual diet variation such as variations in habitat or size whereas NVH relies on "ultimate sources" related to the competitive balance between intra- and inter-specific competitions. The latter implies as a corollary that species trophic niche overlap, taken as inter-specific competition measure, decreases as species niche width and individual niche variation increase. We tested the complementary predictions of OFT and NVH in a marine fish assemblage using stomach content data and associated trophic niche metrics. The NVH predictions were tested between species of the assemblage and decomposed into a between- and a within-functional group component to assess the potential influence of species' ecological function. For most species, individual diet variation and niche overlap were consistently larger than expected. Individual diet variation increased with intra-specific variability in individual state and habitat, as expected from OFT. It also increased with species niche width but in compliance with the null expectation, thus not supporting the NVH. In contrast, species niche overlap increased significantly less than null expectation with both species niche width and individual diet variation, supporting NVH corollary. The between- and within-functional group components of the NVH relationships were consistent with those between species at the assemblage level. Changing the number of prey categories used to

  13. Alien fish species in reservoir systems in Turkey: a review

    OpenAIRE

    Deniz Innal

    2012-01-01

    Turkey’s natural river systems have been anthropogenically altered in the past century. Native fish communities of river systems have comeunder increasing pressure from water engineering projects, pollution, overfishing and the movements of alien fish species. Introduction ofalien fishes is one of the main threats to the survival and genetic integrity of native fishes around the world. In Turkey, alien freshwater fish are continuing to increase in number of species, abundance, and distributio...

  14. Yield and soil carbon sequestration in grazed pastures sown with two or five forage species

    Science.gov (United States)

    Increasing plant species richness is often associated with an increase in productivity and associated ecosystem services such as soil C sequestration. In this paper we report on a nine-year experiment to evaluate the relative forage production and C sequestration potential of grazed pastures sown to...

  15. ABC transporters in fish species: a review

    Directory of Open Access Journals (Sweden)

    Marta eFerreira

    2014-07-01

    Full Text Available ATP-binding cassette (ABC proteins were first recognized for their role in multidrug resistance (MDR in chemotherapeutic treatments, which is a major impediment for the successful treatment of many forms of malignant tumors in humans. These proteins, highly conserved throughout vertebrate species, were later related to cellular detoxification and accounted as responsible for protecting aquatic organisms from xenobiotic insults in the so-called multixenobiotic resistance mechanism (MXR. In recent years, research on these proteins in aquatic species has highlighted their importance in the detoxification mechanisms in fish thus it is of extreme added value to continue these studies. Several transporters have been pointed out as relevant in the ecotoxicological context associated to the transport of xenobiotics, such as P-glycoproteins (Pgps, multidrug-resistance-associated proteins (MRPs 1-5 and breast resistance associated protein (BCRP. In mammals, several nuclear receptors have been identified as mediators of phase I and II metabolizing enzymes and ABC transporters. In aquatic species, knowledge on co-regulation of detoxification mechanism is scarce and needs to be addressed. The interaction of emergent contaminants, with chemosensitizer potential, with ABC transporters in aquatic organisms can compromise detoxification processes and have population effects and should be studied in more detail. This review intends to summarize the recent advances in research on MXR mechanisms in fish species, focusing in 1 regulation and functioning of ABC proteins; 2 cooperation with phase I and II biotransformation enzymes; and 3 ecotoxicological relevance and information on emergent pollutants with ability to modulate ABC transporters expression and activity. Several lines of evidence are clear suggesting the important role of these transporters in detoxification mechanisms and must be further investigated in fish.

  16. Multipurpose uses of forage species, estimation of availability and ...

    African Journals Online (AJOL)

    The percentage crude fibre content of Icancina trichantha (73. 8%) was highest compared with the other browse species. Browse species from Edemani community gave significantly (P < 0.05) higher crude fibre contents than those from Obukpa community. Elaeis guineensis had significantly (P < 0.05) the highest ash ...

  17. The distribution, composition and abundance of fish species in two ...

    African Journals Online (AJOL)

    Fish composition and abundance of two Gold mine reservoir were investigated between May, 2008 and May, 2009. Seven fish families comprising of twelve species of fish were caught during the period of study. The families of fish caught included Anabantidae, Channidae, Clariidae, Cichlidae, Melanopluridae, Mormyridae ...

  18. Effects of forage species or concentrate finishing on animal performance, carcass and meat quality.

    Science.gov (United States)

    Duckett, S K; Neel, J P S; Lewis, R M; Fontenot, J P; Clapham, W M

    2013-03-01

    Angus-cross steers (n = 128; initial BW = 270 ± 3.8 kg) were used in a 3-yr study to assess effects of forage species grazed before slaughter versus concentrate finishing on carcass and meat quality. At the completion of the stockering phase, steers were randomly allotted to mixed pasture (MP; n = 36/yr) or corn-silage concentrate (CON; n = 12/yr) finishing treatments. At 40 d before harvest, MP steers were randomly divided into 3 forage species treatments: alfalfa (AL), pearl millet (PM), or mixed pasture (MP). Average daily BW gain was greater (P = 0.001) for CON than for forage-finished (FOR) steers during the early and overall finishing phase. During the late finishing phase when FOR steers were grazing difference forage species, ADG was greater (P = 0.03) for PM than MP or AL. Harvest weight and HCW were greater (P animal performance. Total fat percentage of the 9th to 11th rib section was 46% less(P = 0.028) for FOR than CON due to reductions (P 0.78) between CON and FOR and were not altered (P > 0.40) by forage species. Trained sensory panel juiciness, initial tenderness, and overall tenderness scores did not differ (P > 0.17) by finishing treatment or forage species. Beef flavor intensity was greater (P 0.05) total lipid content of the LM. Oleic acid concentration and total MUFA of the LM were 21% and 22% less (P = 0.001) for FOR than CON. Concentrations of all individual [linolenic acid, eicosapentaenoic (EPA), docosapentaenoic (DPA), and docosadexaenoic (DHA) acids] and total n-3 fatty acids were greater (P carcass weight with same time endpoints and accelerates deposition of MUFA in comparison with FOR, which reduces carcass weight and fat deposition but maintains high concentrations of n-3 and CLA fatty acids. Finishing system or forage species grazed 40 d before slaughter did not alter beef tenderness but FOR had greater off-flavors according to both trained and descriptive sensory panelists.

  19. Investigation of biological condition of fish species in lower Ogun ...

    African Journals Online (AJOL)

    The study was carried out to investigate the biological condition of fish species in lower Ogun River wetlands. A total of 175 individual fish belonging to 10 species were collected from artisanal fishermen using different types of fishing gears. Two biological indices; condition factor “K” and growth exponent “b” obtained from ...

  20. Turtle cleaners: reef fishes foraging on epibionts of sea turtles in the tropical Southwestern Atlantic, with a summary of this association type

    Directory of Open Access Journals (Sweden)

    Cristina Sazima

    2010-03-01

    Full Text Available In the present study we record several instances of reef fish species foraging on epibionts of sea turtles (cleaning symbiosis at the oceanic islands of Fernando de Noronha Archipelago and near a shipwreck, both off the coast of Pernambuco State, northeast Brazil. Nine reef fish species and three turtle species involved in cleaning are herein recorded. Besides our records, a summary of the literature on this association type is presented. Postures adopted by turtles during the interaction are related to the habits of associated fishes. Feeding associations between fishes and turtles seem a localized, albeit common, phenomenon.No presente estudo registramos diversos episódios de peixes recifais alimentando-se de epibiontes sobre o corpo de tartarugas marinhas (simbiose de limpeza nas ilhas oceânicas do arquipélago de Fernando de Noronha e próximo a um naufrágio na costa de Pernambuco, nordeste do Brasil. Nove espécies de peixes recifais e três espécies de tartarugas envolvidas nas associações são aqui registradas. Além de nossos registros, apresentamos também um resumo da literatura sobre o tema. As posturas adotadas pelas tartarugas durante as interações estão relacionadas com os hábitos dos peixes associados. Associações alimentares entre peixes e tartarugas podem ser consideradas como um fenômeno local, embora comum.

  1. Fish species diversity and conservation in Beijing and adjacent areas

    OpenAIRE

    Chunguang Zhang; Yahui Zhao; Yingchun Xing; Ruilu Guo; Qing Zhang; Yun Feng; Enyuan Fan

    2011-01-01

    Based on field surveys between 2002 and 2010, and fish collections in the National Zoological Museum, Institute of Zoology, Chinese Academy of Sciences, a total of 93 wild fish species including 12 in-troduced species had been recorded in Beijing and adjacent areas. Eighty five of these species, including some migratory and estuarine fishes, are native to the region. Only 43 native wild species were collected in our field work from 2002 to 2010. Compared with the historical records, nearly 50...

  2. Phylogeny of Fish-Infecting Calyptospora species (Apicomplexa: Eimeriorina)

    Science.gov (United States)

    There are numerous species of apicomplexans that infect poikilothermic vertebrates such as fishes, and possess unique morphological features that provide insight into the evolution of this important phylum of parasites. Here the relationship of the fish-infecting Calyptospora spe...

  3. DNA barcode-based molecular identification system for fish species.

    Science.gov (United States)

    Kim, Sungmin; Eo, Hae-Seok; Koo, Hyeyoung; Choi, Jun-Kil; Kim, Won

    2010-12-01

    In this study, we applied DNA barcoding to identify species using short DNA sequence analysis. We examined the utility of DNA barcoding by identifying 53 Korean freshwater fish species, 233 other freshwater fish species, and 1339 saltwater fish species. We successfully developed a web-based molecular identification system for fish (MISF) using a profile hidden Markov model. MISF facilitates efficient and reliable species identification, overcoming the limitations of conventional taxonomic approaches. MISF is freely accessible at http://bioinfosys.snu.ac.kr:8080/MISF/misf.jsp .

  4. Alien fish species in reservoir systems in Turkey: a review

    Directory of Open Access Journals (Sweden)

    Deniz Innal

    2012-12-01

    Full Text Available Turkey’s natural river systems have been anthropogenically altered in the past century. Native fish communities of river systems have comeunder increasing pressure from water engineering projects, pollution, overfishing and the movements of alien fish species. Introduction ofalien fishes is one of the main threats to the survival and genetic integrity of native fishes around the world. In Turkey, alien freshwater fish are continuing to increase in number of species, abundance, and distribution. The present paper reviews fish stocking studies in Turkey’s reservoirs.

  5. Evaluating the role of large jellyfish and forage fishes as energy pathways, and their interplay with fisheries, in the Northern Humboldt Current System

    Science.gov (United States)

    Chiaverano, Luciano M.; Robinson, Kelly L.; Tam, Jorge; Ruzicka, James J.; Quiñones, Javier; Aleksa, Katrina T.; Hernandez, Frank J.; Brodeur, Richard D.; Leaf, Robert; Uye, Shin-ichi; Decker, Mary Beth; Acha, Marcelo; Mianzan, Hermes W.; Graham, William M.

    2018-05-01

    Large jellyfish are important consumers of plankton, fish eggs and fish larvae in heavily fished ecosystems worldwide; yet they are seldom included in fisheries production models. Here we developed a trophic network model with 41 functional groups using ECOPATH re-expressed in a donor-driven, end-to-end format to directly evaluate the efficiency of large jellyfish and forage fish at transferring energy to higher trophic levels, as well as the ecosystem-wide effects of varying jellyfish and forage fish consumption rates and fishing rates, in the Northern Humboldt Current system (NHCS) off of Peru. Large jellyfish were an energy-loss pathway for high trophic-level consumers, while forage fish channelized the production of lower trophic levels directly into production of top-level consumers. A simulated jellyfish bloom resulted in a decline in productivity of all functional groups, including forage fish (12%), with the exception of sea turtles. A modeled increase in forage fish consumption rate by 50% resulted in a decrease in large jellyfish productivity (29%). A simulated increase of 40% in forage fish harvest enhanced jellyfish productivity (24%), while closure of all fisheries caused a decline in large jellyfish productivity (26%) and productivity increases in upper level consumers. These outcomes not only suggest that jellyfish blooms and fisheries have important effects on the structure of the NHCS, but they also support the hypothesis that forage fishing provides a competitive release for large jellyfish. We recommend including jellyfish as a functional group in future ecosystem modeling efforts, including ecosystem-based approaches to fishery management of coastal ecosystems worldwide.

  6. Satellite lakes as reservoirs of fish species diversity

    OpenAIRE

    Nkalubo, W.; Wandera, S.B.; Namulemo, G.

    2010-01-01

    Satellite lakes and rivers in the Victoria and Kyoga basins provide a sanctuary for endangered native fish species. The structural heterogeneity of macrophyte covering these lakes has made it possible for most of the biodiversity to be kept intact. The Kyoga minor lakes have the highest fish species diversity especially of the haplochromines. Most fish communities of these satellite lakes are composed of native species.

  7. Forage fish quality: seasonal lipid dynamics of herring (Clupea harengus L.) and sprat (Sprattus sprattus L.) in the Baltic Sea

    DEFF Research Database (Denmark)

    Røjbek, Maria; Tomkiewicz, Jonna; Jacobsen, Charlotte

    2013-01-01

    seasonally with high levelstowards the end of the annual zooplankton production cycle, succeeded by a decline. Lipid content and fatty acid composition differed significantly between sprat and herring. Sprat lipid content was higher than herring, increasing with fish size and characterized by large......This study investigates lipid content and fatty acid composition of two important forage fish, sprat (Sprattus sprattus) and herring (Clupea harengus) in the Baltic Sea ecosystem. Seasonal variation in lipids was studied during three periods following the annual reproductive cycle considering...... potential differences relating to fish size, sex, and reproductive status. The isopod Saduria entomon, being at times an important prey for predatory fish, was included for comparison. In both sprat and herring, lipid content and absolute contents of essential polyunsaturated fatty acids (PUFAs) varied...

  8. Analysis of the potentiality haying of native forage species in semiarid region

    Directory of Open Access Journals (Sweden)

    Enoque de Sousa Leão

    2017-10-01

    Full Text Available The objective of this study was to evaluate the potential hay production from Spiny Amaranth (Amaranthus spinosus, Hairy Woodrose (Merremia aegyptia, Malva (Sida galheirensis, Mucuna (Mucuna pruriens and Ervanço (Froelichia humboldtiana, native forage species of the semiarid region of Brazil by observing morphological components of the plant, such as the dehydration curve, crude protein loss (CPL curve, chemical composition of plant and hay and hay degradability in situ. There were differences (P < 0.05 among species on leaf, stem and inflorescence quantification with Ervanço, Hairy Woodrose, and Mucuna having a greater number of leaves. There was a linearly increasing response for the dehydration curve of the five forage plants species. Mucuna forage had the greatest hay point at 800 g kg-1 dried matter (DM after 11.8 hours and Woodrose had a lower dehydration efficiency, which required 25 hours of sun exposure. There was no difference in CPL. Mucuna had the lowest crude protein (CP, neutral detergent fiber (NDF and acid detergent fiber (ADF content, 8.4, 67.7 and 73.8 g kg DM-1 in hay in relation to the plant, respectively. Ervanço, Spiny Amaranth, Hairy Woodrose and Malva hay had more of soluble fraction “a” of DM of 31.0, 26.2, 22.1 and 9.7 g kg-1 DM than Mucuna, respectively. Spiny Amaranth and Malva hay had values of 335.4 and 193.2 g kg-1 DM of fraction “b” more than Ervanço hay, respectively. For fraction “a’’ of CP, Spiny Amaranth and Hairy Woodrose hay obtained 312.6 and 227.4 g kg-1 CP more than that observed for Malva, respectively. Mucuna had better hay potential among the forage studied in the semiarid region of Brazil.

  9. Foragers of sympatric Asian honey bee species intercept competitor signals by avoiding benzyl acetate from Apis cerana alarm pheromone.

    Science.gov (United States)

    Wen, Ping; Cheng, Yanan; Qu, Yufeng; Zhang, Hongxia; Li, Jianjun; Bell, Heather; Tan, Ken; Nieh, James

    2017-07-27

    While foraging, animals can form inter- and intraspecific social signalling networks to avoid similar predators. We report here that foragers of different native Asian honey bee species can detect and use a specialized alarm pheromone component, benzyl acetate (BA), to avoid danger. We analysed the volatile alarm pheromone produced by attacked workers of the most abundant native Asian honey bee, Apis cerana and tested the responses of other bee species to these alarm signals. As compared to nest guards, A. cerana foragers produced 3.38 fold higher levels of BA. In foragers, BA and (E)-dec-2-en-1-yl acetate (DA) generated the strongest antennal electrophysiological responses. BA was also the only compound that alerted flying foragers and inhibited A. cerana foraging. BA thereby decreased A. cerana foraging for risky sites. Interestingly, although BA occurs only in trace amounts and is nearly absent in sympatric honeybee species (respectively only 0.07% and 0.44% as much in A. dorsata and A. florea), these floral generalists detected and avoided BA as strongly as they did to their own alarm pheromone on natural inflorescences. These results demonstrate that competing pollinators can take advantage of alarm signal information provided by other species.

  10. SURROGATE SPECIES IN ASSESSING CONTAMINANT RISK FOR ENDANGERED FISHES

    Science.gov (United States)

    Rainbow trout, fathead minnows, and sheepshead minnows were tested as surrogate species to assess contaminant risk for 17 endangered fishes and one toad species. Acute toxicity tests were conducted with carbaryl, copper, 4-nonylphenol, pentachlorophenol, and permethrin in accord...

  11. Forage yield and nutritive value of Elephant grass, Italian ryegrass and spontaneous growing species mixed with forage peanut or red clover

    Directory of Open Access Journals (Sweden)

    Michelle Schalemberg Diehl

    2014-10-01

    Full Text Available The objective of this research was to evaluate of three grazing systems (GS with elephant grass (EG, Italian ryegrass (IR + spontaneous growing species (SGS; EG + IR + SGS + forage peanut (FP; and EG + IR + SGS + red clover (RC, during the winter and summer periods in rotational grazing with dairy cattle. Experimental design was completely randomized with three treatments, two replicates with repeated measures. Lactating Holstein cows receiving 1% BW-daily feed supplement with concentrate were used in the evaluation. Eight grazing cycles were performed during the experimental period. The values of pre forage mass and stocking rate were 2.52, 2.60 and 2.99 t ha-1 and 2.64, 2.77 and 3.14 animal unit ha-1, respectively for GS. Samples of forage were collected by hand-plucking technique to analyze the crude protein (CP, neutral detergent fiber (NDF, in situ dry matter digestibility (ISDMD, in situ organic matter digestibility (ISOMD of forage present between rows of elephant grass, in the rows of elephant grass and the legumes. Higher value of CP, ISOMD and lower of NDF were observed for the grazing systems mixed with legumes forage.

  12. Endangered Fish Species in Kansas: Historic vs Contemporary Distribution

    Science.gov (United States)

    Background/Question/Methods Kansas state has more freshwater fish species than other states in the west and northern US. Based on recent count, more than 140 fishes have been documented in Kansas rivers. And at least five are categorized as endangered species in Kansas (and thre...

  13. Salinity ranges of some southern African fish species occurring in ...

    African Journals Online (AJOL)

    The recorded salinity ranges of 96 fish species occurring in southern African estuaries are documented. Factors influen- cing the tolerance of fishes to low and high salinity regimes are discussed, with most species tolerant of low rather than high salinity conditions. This is important since most systems are subject to periodic ...

  14. Total mercury concentration in common fish species of Lake Victoria ...

    African Journals Online (AJOL)

    Total mercury (THg) concentration was analysed in muscles of common fish species of Lake Victoria in the eastern and southern parts of the lake using cold vapour Atomic Absorption Spectrophotometric technique. Mercury concentration in all fish species was generally lower than the WHO maximum allowable ...

  15. Composition of Mix Species Foraging Flocks of Birds in Riverstan of Montane Region, Sri Lanka

    Directory of Open Access Journals (Sweden)

    W.G.D.D.M. Shermila

    2013-04-01

    Full Text Available Montane zone mixed-species bird flock system is distinct from that of low-land wet zone of SriLanka, although some species are present in both systems. The present study identified the mixed speciesflocks of birds in Riverstan at Knuckles Region, Sri Lanka. Monthly transect counts and opportunisticobservations were made between January and May, 2012. A total of 78 flocks and 27 bird species wereencountered at Riverstan during the study period. The flock size varied between 2 to 13 species and 4 to58 individuals. The mean number of species per flock was 6.03 ± 2.25 and the mean number ofindividuals in a flock was 18.41±9.87. The flock size was positively correlated with the number of speciespresent (r = 0.756, P <0.05. Grey-headed Canary Flycatcher was the most abundant species (mean2.68±1.02 birds per flocks while Sri Lanka White-eye was the most frequent species (mean 5.69±3.92birds per flocks. Grey-headed Canary Flycatcher and Sri Lanka Scimitar-babbler were the nuclear speciesin Riverstan. The leading species were Sri Lanka white-eye and Sri Lanka Yellow-eared Bulbul. Differentbird species used different heights within flocks.Keywords: Mixed-species flock, Nuclear species, Abundance, Foraging flocks

  16. Identification And Study Of Fish Species In Karkheh River (Iran

    Directory of Open Access Journals (Sweden)

    Khoshnood Zahra

    2014-10-01

    Full Text Available For the investigation of fish from Karkheh River, sampling was performed in a six month period from August 2014 to January 2015. All sampled fish were measured for biometrical values (length and weight. General results of the sampling and identification of the fish showed the presence of 14 species from four fish families of Cyprinidae, Mugilidae, Siluridae and Macrostomidae, out of which the Cyprinidae family were the most frequent of the sampled fish. The most significant abundance belongs to Cyprinus carpio. The fish sampled in the present study were: Liza abu, Ctenopharyngodon idella, Barbel sp., Cyprinion macrostomum, Barbus sharpeyi, Hypophthalmichthys molitrix, Barbus esocinus, Barbus barbulus, Barbus luteus, Barbus grypus, Cyprinus carpio, Silurus triostegus, Mastacembelus circumcinctus and Capoeta trutta. Shannon Index results showed that the fish biodiversity in the studyed area followed a uniform path and additionally that the considered area at the studied period has good fish biodiversity.

  17. Genetic calibration of species diversity among North America's freshwater fishes.

    Science.gov (United States)

    April, Julien; Mayden, Richard L; Hanner, Robert H; Bernatchez, Louis

    2011-06-28

    Freshwater ecosystems are being heavily exploited and degraded by human activities all over the world, including in North America, where fishes and fisheries are strongly affected. Despite centuries of taxonomic inquiry, problems inherent to species identification continue to hamper the conservation of North American freshwater fishes. Indeed, nearly 10% of species diversity is thought to remain undescribed. To provide an independent calibration of taxonomic uncertainty and to establish a more accessible molecular identification key for its application, we generated a standard reference library of mtDNA sequences (DNA barcodes) derived from expert-identified museum specimens for 752 North American freshwater fish species. This study demonstrates that 90% of known species can be delineated using barcodes. Moreover, it reveals numerous genetic discontinuities indicative of independently evolving lineages within described species, which points to the presence of morphologically cryptic diversity. From the 752 species analyzed, our survey flagged 138 named species that represent as many as 347 candidate species, which suggests a 28% increase in species diversity. In contrast, several species of parasitic and nonparasitic lampreys lack such discontinuity and may represent alternative life history strategies within single species. Therefore, it appears that the current North American freshwater fish taxonomy at the species level significantly conceals diversity in some groups, although artificially creating diversity in others. In addition to providing an easily accessible digital identification system, this study identifies 151 fish species for which taxonomic revision is required.

  18. The Relationships between Morphological Characteristics and Foraging Behavior in Four Selected Species of Shorebirds and Water Birds Utilizing Tropical Mudflats

    Directory of Open Access Journals (Sweden)

    Nor Atiqah Norazlimi

    2015-01-01

    Full Text Available A study was conducted to investigate the relationship between the physical morphology of shorebirds and water birds (i.e., Lesser adjutant (Leptoptilos javanicus, Common redshank (Tringa totanus, Whimbrel (Numenius phaeopus, and Little heron (Butorides striata and their foraging behavior in the mudflats area of Selangor, Peninsular Malaysia, from August 2013 to July 2014 by using direct observation techniques (using binoculars and a video recorder. The actively foraging bird species were watched, and their foraging activities were recorded for at least 30 seconds for up to a maximum of five minutes. A Spearman Rank Correlation highlighted a significant relationship between bill size and foraging time (R=0.443, p<0.05, bill size and prey size (R=-0.052, p<0.05, bill size and probing depth (R=0.42, p=0.003, and leg length and water/mud depth (R=0.706, p<0.005. A Kruskal-Wallis Analysis showed a significant difference between average estimates of real probing depth of the birds (mm and species (H=15.96, p=0.0012. Three foraging techniques were recorded: pause-travel, visual-feeding, and tactile-hunting. Thus, morphological characteristics of bird do influence their foraging behavior and strategies used when foraging.

  19. Swimbladder Allometry of Selected Midwater Fish Species

    Science.gov (United States)

    1976-01-05

    Gibbs, R. II., Jr., 1971. "Notes on Fishes of the Genus Eustomias ( Stomiatoidei , Melanstomiatidae) in Bermuda Waters, With the Description of...N00140-70-C-0307, Smithsonian Institution. Goodyear, R. H. and R. H. Gibbs, Jr., 1970. "Systematics and Zoogeography of Stomiatoid Fishes of the

  20. POPs and stable isotopes in bird and forage fish tissues - Persistent organic pollutant levels in juvenile salmonids, forage fish and their avian predators from Puget Sound and the outer WA coast

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This project is examining contaminant loads of fish prey species of a resident marine bird (Rhinoceros Auklet) breeding in inland waters (Puget Sound) and in the...

  1. Oral vaccination of fish: Lessons from humans and veterinary species.

    Science.gov (United States)

    Embregts, Carmen W E; Forlenza, Maria

    2016-11-01

    The limited number of oral vaccines currently approved for use in humans and veterinary species clearly illustrates that development of efficacious and safe oral vaccines has been a challenge not only for fish immunologists. The insufficient efficacy of oral vaccines is partly due to antigen breakdown in the harsh gastric environment, but also to the high tolerogenic gut environment and to inadequate vaccine design. In this review we discuss current approaches used to develop oral vaccines for mass vaccination of farmed fish species. Furthermore, using various examples from the human and veterinary vaccine development, we propose additional approaches to fish vaccine design also considering recent advances in fish mucosal immunology and novel molecular tools. Finally, we discuss the pros and cons of using the zebrafish as a pre-screening animal model to potentially speed up vaccine design and testing for aquaculture fish species. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

  2. Forage fish interactions: A symposium on creating the tools for ecosystem-based management of marine resources

    DEFF Research Database (Denmark)

    Peck, M.A.; Neuenfeldt, Stefan; Essington, V.M.

    2014-01-01

    Forage fish (FF) have a unique position within marine foodwebs and the development of sustainable harvest strategies for FF will be a critical step in advancing and implementing the broader, ecosystem-based management of marine systems. In all, 70 scientists from 16 nations gathered for a symposium...... on 12–14 November 2012 that was designed to address three key questions regarding the effective management of FF and their ecosystems: (i) how do environmental factors and predator–prey interactions drive the productivity and distribution of FF stocks across ecosystems worldwide, (ii) what...

  3. Complementarity in nutrient foraging strategies of absorptive fine roots and arbuscular mycorrhizal fungi across 14 coexisting subtropical tree species.

    Science.gov (United States)

    Liu, Bitao; Li, Hongbo; Zhu, Biao; Koide, Roger T; Eissenstat, David M; Guo, Dali

    2015-10-01

    In most cases, both roots and mycorrhizal fungi are needed for plant nutrient foraging. Frequently, the colonization of roots by arbuscular mycorrhizal (AM) fungi seems to be greater in species with thick and sparsely branched roots than in species with thin and densely branched roots. Yet, whether a complementarity exists between roots and mycorrhizal fungi across these two types of root system remains unclear. We measured traits related to nutrient foraging (root morphology, architecture and proliferation, AM colonization and extramatrical hyphal length) across 14 coexisting AM subtropical tree species following root pruning and nutrient addition treatments. After root pruning, species with thinner roots showed more root growth, but lower mycorrhizal colonization, than species with thicker roots. Under multi-nutrient (NPK) addition, root growth increased, but mycorrhizal colonization decreased significantly, whereas no significant changes were found under nitrogen or phosphate additions. Moreover, root length proliferation was mainly achieved by altering root architecture, but not root morphology. Thin-root species seem to forage nutrients mainly via roots, whereas thick-root species rely more on mycorrhizal fungi. In addition, the reliance on mycorrhizal fungi was reduced by nutrient additions across all species. These findings highlight complementary strategies for nutrient foraging across coexisting species with contrasting root traits. © 2015 The Authors. New Phytologist © 2015 New Phytologist Trust.

  4. 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...

  5. As multiple fish species in large marine ecosystems are harvested ...

    African Journals Online (AJOL)

    CMPTMAC10

    and of other top predators such as marine mammals. This concern ... whereas single-species fishing theory implies that fishing leads to surplus by removing larger, older, less-productive ...... pools (the “cod is not a tuna” problem, Longhurst.

  6. Fish species composition, diversity and abundance of the lower New ...

    African Journals Online (AJOL)

    A thirteen-week investigation to determine the fish species composition, diversity and abundance of the Lower New Calabar River, in Rivers State, aimed at providing information on the fish stock and their status for documentation, knowledge improvement, and development of conservation and management strategies was ...

  7. Alien fish species in upper Sakarya River and their distribution ...

    African Journals Online (AJOL)

    However, the fact that the flood plains have been reclaimed, excessive hunting, destruction of the ecologic balance and invasion of the area by the alien fish species threatens the fish stocks in Sakarya River. In this study, we aimed to determine the dispersion area of Carassius gibelio (Bloch, 1782), Oreochromis niloticus ...

  8. Listeria species in retail smoked fish at Jos, Nigeria | Chukwu ...

    African Journals Online (AJOL)

    The prevalence of Listeria species in 65 samples of smoked fish at the retail markets in Jos, Nigeria, is reported. The experimental samples which included 30 catfish (Clarias species) and 35 Tilapia were screened for Listeria monocytogenes and other Listeria species using a two-step enrichment method. Total Listeria ...

  9. Three-dimensional foraging habitat use and niche partitioning in two sympatric seabird species, Phalacrocorax auritus and P. penicillatus

    Science.gov (United States)

    Peck-Richardson, Adam G.; Lyons, Donald E.; Roby, Daniel D.; Cushing, Daniel A.; Lerczak, James A.

    2018-01-01

    Ecological theory predicts that co-existing, morphologically similar species will partition prey resources when faced with resource limitations. We investigated local movements, foraging dive behavior, and foraging habitat selection by breeding adults of 2 closely related cormorant species, double-crested cormorants Phalacrocorax auritus and Brandt’s cormorants P. penicillatus. These species nest sympatrically at East Sand Island in the Columbia River estuary at the border of Oregon and Washington states, USA. Breeding individuals of each species were tracked using GPS tags with integrated temperature and depth data-loggers. The overall foraging areas and core foraging areas (defined as the 95% and 50% kernel density estimates of dive locations, respectively) of double-crested cormorants were much larger and covered a broader range of riverine, mixed-estuarine, and nearshore marine habitats. Brandt’s cormorant foraging areas were less expansive, were exclusively marine, and mostly overlapped with double-crested cormorant foraging areas. Within these areas of overlap, Brandt’s cormorants tended to dive deeper (median depth = 6.48 m) than double-crested cormorants (median depth = 2.67 m), and selected dive locations where the water was deeper. Brandt’s cormorants also utilized a deeper, more benthic portion of the water column than did double-crested cormorants. Nevertheless, the substantial overlap in foraging habitat between the 2 cormorant species in the Columbia River estuary, particularly for Brandt’s cormorants, suggests that superabundant prey resources allow these 2 large and productive cormorant colonies to coexist on a single island near the mouth of the Columbia River.

  10. Mercury concentrations of a resident freshwater forage fish at Adak Island, Aleutian Archipelago, Alaska.

    Science.gov (United States)

    Kenney, Leah A; von Hippel, Frank A; Willacker, James J; O'Hara, Todd M

    2012-11-01

    The Aleutian Archipelago is an isolated arc of over 300 volcanic islands stretching 1,600 km across the interface of the Bering Sea and North Pacific Ocean. Although remote, some Aleutian Islands were heavily impacted by military activities from World War II until recently and were exposed to anthropogenic contaminants, including mercury (Hg). Mercury is also delivered to these islands via global atmospheric transport, prevailing ocean currents, and biotransport by migratory species. Mercury contamination of freshwater ecosystems is poorly understood in this region. Total Hg (THg) concentrations were measured in threespine stickleback fish (Gasterosteus aculeatus) collected from eight lakes at Adak Island, an island in the center of the archipelago with a long military history. Mean THg concentrations for fish whole-body homogenates for all lakes ranged from 0.314 to 0.560 mg/kg dry weight. Stickleback collected from seabird-associated lakes had significantly higher concentrations of THg compared to non-seabird lakes, including all military lakes. The δ(13)C stable isotope ratios of stickleback collected from seabird lakes suggest an input of marine-derived nutrients and/or marine-derived Hg. Copyright © 2012 SETAC.

  11. Genetic calibration of species diversity among North America's freshwater fishes

    OpenAIRE

    April, Julien; Mayden, Richard L.; Hanner, Robert H.; Bernatchez, Louis

    2011-01-01

    Freshwater ecosystems are being heavily exploited and degraded by human activities all over the world, including in North America, where fishes and fisheries are strongly affected. Despite centuries of taxonomic inquiry, problems inherent to species identification continue to hamper the conservation of North American freshwater fishes. Indeed, nearly 10% of species diversity is thought to remain undescribed. To provide an independent calibration of taxonomic uncertainty and to establish a mor...

  12. Movement patterns for a critically endangered species, the leatherback turtle (Dermochelys coriacea), linked to foraging success and population status.

    Science.gov (United States)

    Bailey, Helen; Fossette, Sabrina; Bograd, Steven J; Shillinger, George L; Swithenbank, Alan M; Georges, Jean-Yves; Gaspar, Philippe; Strömberg, K H Patrik; Paladino, Frank V; Spotila, James R; Block, Barbara A; Hays, Graeme C

    2012-01-01

    Foraging success for pelagic vertebrates may be revealed by horizontal and vertical movement patterns. We show markedly different patterns for leatherback turtles in the North Atlantic versus Eastern Pacific, which feed on gelatinous zooplankton that are only occasionally found in high densities. In the Atlantic, travel speed was characterized by two modes, indicative of high foraging success at low speeds (turtles. The most parsimonious explanation for these findings is that Eastern Pacific turtles rarely achieve high foraging success. This is the first support for foraging behaviour differences between populations of this critically endangered species and suggests that longer periods searching for prey may be hindering population recovery in the Pacific while aiding population maintenance in the Atlantic.

  13. Variations in protein and fat contents and their fractions in milk from two species fed different forages.

    Science.gov (United States)

    Kholif, S M; El-Shewy, A A; Morsy, T A; Abd El-Rahman, H H

    2015-02-01

    This study aimed at determining the variations in milk constituents which could be varied by feed and animal species. To achieve this goal, two groups of homoparity Baladi cows and Egyptian buffaloes (n = 20 per species) were used. Each group was divided into two subgroups (n = 10): subgroup I received legume forage (Egyptian clover) and subgroup II received grass forage (sorghum forage). All experimental animals were fed the diet consisting of concentrate, forage and rice straw as 50, 25 and 25% of dry matter intake respectively. Milk samples were taken for analysis. The trial lasted until the 3rd month of parturition. The main results indicated that lactating cattle fed legume forage significantly (p ≤ 0.01) had more content of casein nitrogen (513 mg/100 ml milk), lower content of glutamic acid (23.56 g/100 g milk protein) and more content of cis-9, trans-11 18:2 conjugated linoleic acid (CLA) (0.77 g/100 g milk fat) compared with 433, 26.67 and 0.53, respectively, for cattle fed grass forage. With regard to the species effect, results showed that buffalo milk appeared to contain significantly higher (p ≤ 0.01) contents of casein nitrogen, phenylalanine, glutamic and arachidonic acid compared with cow's milk. However, the latter was significantly (p ≤ 0.01) more in the cis-9, trans-11CLA (0.59 g/100 g milk fat) than that in buffalo milk (0.47 g/100 g milk fat). The results revealed that not only forage type played a critical role in determining the variations of milk nitrogen distribution, milk amino acids and fatty acids but also animal species had a significant effect on these parameters. Journal of Animal Physiology and Animal Nutrition © 2014 Blackwell Verlag GmbH.

  14. Development of Solar Drying Model for Selected Cambodian Fish Species

    Science.gov (United States)

    Hubackova, Anna; Kucerova, Iva; Chrun, Rithy; Chaloupkova, Petra; Banout, Jan

    2014-01-01

    A solar drying was investigated as one of perspective techniques for fish processing in Cambodia. The solar drying was compared to conventional drying in electric oven. Five typical Cambodian fish species were selected for this study. Mean solar drying temperature and drying air relative humidity were 55.6°C and 19.9%, respectively. The overall solar dryer efficiency was 12.37%, which is typical for natural convection solar dryers. An average evaporative capacity of solar dryer was 0.049 kg·h−1. Based on coefficient of determination (R 2), chi-square (χ 2) test, and root-mean-square error (RMSE), the most suitable models describing natural convection solar drying kinetics were Logarithmic model, Diffusion approximate model, and Two-term model for climbing perch and Nile tilapia, swamp eel and walking catfish and Channa fish, respectively. In case of electric oven drying, the Modified Page 1 model shows the best results for all investigated fish species except Channa fish where the two-term model is the best one. Sensory evaluation shows that most preferable fish is climbing perch, followed by Nile tilapia and walking catfish. This study brings new knowledge about drying kinetics of fresh water fish species in Cambodia and confirms the solar drying as acceptable technology for fish processing. PMID:25250381

  15. Development of Solar Drying Model for Selected Cambodian Fish Species

    Directory of Open Access Journals (Sweden)

    Anna Hubackova

    2014-01-01

    Full Text Available A solar drying was investigated as one of perspective techniques for fish processing in Cambodia. The solar drying was compared to conventional drying in electric oven. Five typical Cambodian fish species were selected for this study. Mean solar drying temperature and drying air relative humidity were 55.6°C and 19.9%, respectively. The overall solar dryer efficiency was 12.37%, which is typical for natural convection solar dryers. An average evaporative capacity of solar dryer was 0.049 kg·h−1. Based on coefficient of determination (R2, chi-square (χ2 test, and root-mean-square error (RMSE, the most suitable models describing natural convection solar drying kinetics were Logarithmic model, Diffusion approximate model, and Two-term model for climbing perch and Nile tilapia, swamp eel and walking catfish and Channa fish, respectively. In case of electric oven drying, the Modified Page 1 model shows the best results for all investigated fish species except Channa fish where the two-term model is the best one. Sensory evaluation shows that most preferable fish is climbing perch, followed by Nile tilapia and walking catfish. This study brings new knowledge about drying kinetics of fresh water fish species in Cambodia and confirms the solar drying as acceptable technology for fish processing.

  16. Radurization of commercial freshwater fish species

    International Nuclear Information System (INIS)

    Chuaqui-Offermanns, N.; McDougall, T.E.; Sprung, W.; Sullivan, V.

    1988-01-01

    The effect of radurization on the shelf life of fresh Whitefish obtained through ordinary commercial channels has been determined. Whitefish fillets irradiated at 1.2 kGy and stored at 3 0 C have a shelf life three times longer than the unirradiated fish. When the fish was irradiated at 0.82 kGy a two fold shelf-life extension was obtained. The shelf life was estimated by sensory, chemical and microbiological evaluations. Sensory evaluation involved organoleptic assessment of raw and cooked samples. Since freshwater fish do not contain trimethylamine oxide (TMAO), alternate tests for freshness were required. It was found the determination of hypoxanthine and total volatile acid number (VAN) are excellent tests for freshness and quality of freshwater fish; thus, these analyses were adopted. The degree of radiation-induced lipid oxidation was measured by the thiobarbituric acid test (TBA). It was found at doses of 0.82 and 1.2 kGy the TBA number remained within acceptable limits in all samples. Microbiological analyses consisted of the total microbial load assessment in the sample, as well as Pseudomonas and total psychrotrophic counts. The estimated shelf lives as determined by the three separate evaluations were in very good agreement. (author)

  17. Radurization of commercial freshwater fish species

    Energy Technology Data Exchange (ETDEWEB)

    Chuaqui-Offermanns, N.; McDougall, T.E.; Sprung, W.; Sullivan, V.

    1988-01-01

    The effect of radurization on the shelf life of fresh Whitefish obtained through ordinary commercial channels has been determined. Whitefish fillets irradiated at 1.2 kGy and stored at 3/sup 0/C have a shelf life three times longer than the unirradiated fish. When the fish was irradiated at 0.82 kGy a two fold shelf-life extension was obtained. The shelf life was estimated by sensory, chemical and microbiological evaluations. Sensory evaluation involved organoleptic assessment of raw and cooked samples. Since freshwater fish do not contain trimethylamine oxide (TMAO), alternate tests for freshness were required. It was found the determination of hypoxanthine and total volatile acid number (VAN) are excellent tests for freshness and quality of freshwater fish;thus, these analyses were adopted. The degree of radiation-induced lipid oxidation was measured by the thiobarbituric acid test (TBA). It was found at doses of 0.82 and 1.2 kGy the TBA number remained within acceptable limits in all samples. Microbiological analyses consisted of the total microbial load assessment in the sample, as well as Pseudomonas and total psychrotrophic counts. The estimated shelf lives as determined by the three separate evaluations were in very good agreement

  18. How Do Grass Species, Season and Ensiling Influence Mycotoxin Content in Forage?

    Directory of Open Access Journals (Sweden)

    Adam Nawrath

    2013-11-01

    Full Text Available Mycotoxins are secondary metabolites produced by fungal species that have harmful effects on mammals. The aim of this study was to assess the content of mycotoxins in fresh-cut material of selected forage grass species both during and at the end of the growing season. We further assessed mycotoxin content in subsequently produced first-cutting silages with respect to the species used in this study: Lolium perenne (cv. Kentaur, Festulolium pabulare (cv. Felina, Festulolium braunii (cv. Perseus, and mixtures of these species with Festuca rubra (cv. Gondolin or Poa pratensis (Slezanka. The mycotoxins deoxynivalenol, zearalenone and T-2 toxin were mainly detected in the fresh-cut grass material, while fumonisin and aflatoxin contents were below the detection limits. July and October were the most risky periods for mycotoxins to occur. During the cold temperatures in November and December, the occurrence of mycotoxins in fresh-cut material declined. Although June was a period with low incidence of mycotoxins in green silage, contents of deoxynivalenol and zearalenone in silages from the first cutting exceeded by several times those determined in their biomass collected directly from the field. Moreover, we observed that use of preservatives or inoculants did not prevent mycotoxin production.

  19. Identification of tetrodotoxin and fish species in a dried dressed fish fillet implicated in food poisoning.

    Science.gov (United States)

    Hwang, Deng-Fwu; Hsieh, Yu-Wen; Shiu, Yu-Cheng; Chen, Shu-Kong; Cheng, Chao-An

    2002-02-01

    There were five victims of neurotoxic food poisoning from a dried dressed fish fillet in Changhua County, Taiwan, in February 2000. The toxicity of the dried dressed fish fillets was 243 mouse units per g according to a tetrodotoxin bioassay. The partially purified toxin was identified as tetrodotoxin and anhydrotetrodotoxin. The sequence of the 376-nucleotide region in the cytochrome b gene of the mitochondrial DNA exhibited the same genotype as that of the toxic puffer fish Lagocephalus lunaris. The same single restriction site for Hinfl was found in the polymerase chain reaction (PCR) products from the dried dressed fish fillet and the muscle of L. lunaris, yielding two DNA fragments of 170 and 206 bp. However, no restriction site for Hinfl was found in the PCR products from other toxic puffer fishes, including Takifugu niphobles, Takifugu oblongus, and Takifugu rubripes. Therefore, the species of the dried dressed fish fillet was identified as L. lunaris and its causative agent was identified as tetrodotoxin.

  20. CAGE BREEDING OF WARM WATER FRESHWATER FISH SPECIES

    Directory of Open Access Journals (Sweden)

    Roman Safner

    2008-10-01

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

  1. Patrones de forrajeo en dos especies de peces intermareales herbívoros de las costas de Chile: Efecto de la abundancia y composición química del alimento Foraging patterns of two species of intertidal herbivorous fishes: Effect of food abundance and chemical composition

    Directory of Open Access Journals (Sweden)

    CRISTIAN W. CACERES

    2000-06-01

    in relation to fish herbivory are: i which are the factors that determine the selection or rejection of a given algal item? and ii are herbivorous fishes capable of extracting the nutrients and energy of a macroalgal diet? In this work, we studied in two species of herbivorous intertidal fishes, Scartichthys viridis and Girella laevifrons, the patterns of food selectivity in the field and in laboratory experiments, the assimilation efficiency for different dietary algal items, and the relationship between the observed patterns and the chemical composition of the algae. The results showed that more than 90% of the diet of these organisms consisted of benthic macroalgae. In the field both species present a non-selective trophic behavior in summer and selective one in winter, characterized by the consumption of green algae in the later season. Furthermore, in the experiments of food selection both species showed a similar pattern characterized by the preference of green and red algae. The results of the assimilation experiments, indicate that Girella laevifrons presents higher values of this parameter than Scartichthys viridis, being in the former the green algae Ulva and Enteromorpha, the items that present a higher efficiency of assimilation. Finally, the results obtained suggest in this herbivorous species a strong relationship among the patterns of food selection and the relationship between food composition and digestive characteristics

  2. Endangered fish species of the world - a review

    OpenAIRE

    Radu Hărşan; I. Valentin Petrescu-Mag

    2008-01-01

    The present paper summarizes a large part of the endangered and critically endangered fish species of the world. The list was constructed using the comprehensive IUCN Red List of Threatened Species (available in December 2008) and the well elaborated FISHBASE (available on the official website, in 2008) for taxonomy and accepted scientific names of the species. To these two important sources, many scientific papers and communications were added when recent and useful reports were found. Howev...

  3. Swimming strategy and body plan of the world’s largest fish: implications for foraging efficiency and thermoregulation

    Directory of Open Access Journals (Sweden)

    Mark eMeekan

    2015-09-01

    Full Text Available The largest animals in the oceans eat prey that are orders of magnitude smaller than themselves, implying strong selection for cost-effective foraging to meet their energy demands. Whale sharks (Rhincodon typus may be especially challenged by warm seas that elevate their metabolism and contain sparse prey resources. Using a combination of biologging and satellite tagging, we show that whale sharks use four strategies to save energy and improve foraging efficiency: 1 fixed, low power swimming, 2 constant low speed swimming, 3 gliding and 4 asymmetrical diving. These strategies increase foraging efficiency by 22 – 32% relative to swimming horizontally and resolve the energy-budget paradox of whale sharks. However, sharks in the open ocean must access food resources that reside in relatively cold waters (up to 20oC cooler than the surface at depths of 250-500 m during the daytime, where long, slow gliding descents, continuous ram ventilation of the gills and filter-feeding could rapidly cool the circulating blood and body tissues. We suggest that whale sharks may overcome this problem through their large size and a specialized body plan that isolates highly vascularized red muscle on the dorsal surface, allowing heat to be retained near the centre of the body within a massive core of white muscle. This could allow a warm-adapted species to maintain enhanced function of organs and sensory systems while exploiting food resources in deep, cool water.

  4. The bottlenose dolphin Tursiops truncatus foraging around a fish farm: Effects of prey abundance on dolphins’ behavior

    Directory of Open Access Journals (Sweden)

    Bruno Díaz LÓPEZ

    2009-08-01

    Full Text Available The extent to which prey abundance influences both bottlenose dolphin foraging behavior and group size in the presence of human activities has not previously been studied. The primary aim of this study was to identify and quantify how wild bottlenose dolphins respond, individually and as groups, to the relative abundance of prey around a fish farm. Detailed views of dolphins’ behavior were obtained by focal following individual animals whilst simultaneously collecting surface and underwater behavioral data. A total of 2150 dive intervals were analyzed, corresponding to 342 focal samples, lasting over 34 hours. Bottlenose dolphins remained submerged for a mean duration of 46.4 seconds and a maximum of 249 seconds. This study provides the first quantified data on bottlenose dolphin diving behavior in a marine fin-fish farm area. This study’s results indicate that within a fish farm area used intensively by bottlenose dolphins for feeding, dolphins did not modify dive duration. Additionally, underwater observations confirmed that dolphins find it easier to exploit a concentrated food source and it appears that hunting tactic and not group size plays an important role during feeding activities. Thus, bottlenose dolphins appear capable of modifying their hunting tactics according to the abundance of prey. When top predators display behavioral responses to activities not directed at them, the task of studying all possible effects of human activities can become even more challenging [Current Zoology 55(4: 243–248, 2009].

  5. Genetic assessment of ornamental fish species from North East India.

    Science.gov (United States)

    Dhar, Bishal; Ghosh, Sankar Kumar

    2015-01-25

    Ornamental fishes are traded with multiple names from various parts around the world, including North East India. Most are collected from the wild, due to lack of species-specific culture or breeding, and therefore, such unmanaged collection of the wild and endemic species could lead to severe threats to biodiversity. Despite many regulatory policies, trade of threatened species, including the IUCN listed species have been largely uncontrolled, due to species identification problems arising from the utilization of multiple trade names. So, the development of species-specific DNA marker is indispensable where DNA Barcoding is proved to be helpful in species identification. Here, we investigated, through DNA Barcoding and morphological assessment, the identification of 128 ornamental fish specimens exported from NE India from different exporters. The generated sequences were subjected to similarity match in BOLD-IDS as well as BLASTN, and analysed using MEGA5.2 for species identification through Neighbour-Joining (NJ) clustering, and K2P distance based approach. The analysis revealed straightforward identification of 84 specimens into 35 species, while 44 specimens were difficult to distinguish based on CO1 barcode alone. However, these cases were resolved through morphology, NJ and distanced based method and found to be belonging to 16 species. Among the 51 identified species, 14 species represented multiple trade names; 17 species belonged to threatened category. Species-level identification through DNA Barcoding along with traditional morphotaxonomy reflects its efficacy in regulating ornamental fish trade and therefore, appeals for their conservation in nature. The use of trade names rather than the zoological name created the passage for trafficking of the threatened species and demands immediate attention for sustaining wildlife conservation. Copyright © 2014 Elsevier B.V. All rights reserved.

  6. Trophic interactions between native and introduced fish species in a littoral fish community.

    Science.gov (United States)

    Monroy, M; Maceda-Veiga, A; Caiola, N; De Sostoa, A

    2014-11-01

    The trophic interactions between 15 native and two introduced fish species, silverside Odontesthes bonariensis and rainbow trout Oncorhynchus mykiss, collected in a major fishery area at Lake Titicaca were explored by integrating traditional ecological knowledge and stable-isotope analyses (SIA). SIA suggested the existence of six trophic groups in this fish community based on δ(13)C and δ(15)N signatures. This was supported by ecological evidence illustrating marked spatial segregation between groups, but a similar trophic level for most of the native groups. Based on Bayesian ellipse analyses, niche overlap appeared to occur between small O. bonariensis (<90 mm) and benthopelagic native species (31.6%), and between the native pelagic killifish Orestias ispi and large O. bonariensis (39%) or O. mykiss (19.7%). In addition, Bayesian mixing models suggested that O. ispi and epipelagic species are likely to be the main prey items for the two introduced fish species. This study reveals a trophic link between native and introduced fish species, and demonstrates the utility of combining both SIA and traditional ecological knowledge to understand trophic relationships between fish species with similar feeding habits. © 2014 The Fisheries Society of the British Isles.

  7. Marine foraging and annual fish consumption of a south polar Skua population in the maritime Antarctic

    NARCIS (Netherlands)

    Hahn, S.M.; Ritz, M.S.; Reinhardt, K.

    2008-01-01

    Pelagic fish are an important component of Antarctic food webs but few quantitative data exist on energy transfer from fish to seabirds for the Seasonal Pack-ice Zone. We studied a local population of south polar, skuas Catharacta maccormicki during a whole breeding cycle and estimated its entire

  8. Proteolytic activities in fillets of selected underutilized Australian fish species.

    Science.gov (United States)

    Ahmed, Z; Donkor, O; Street, W A; Vasiljevic, T

    2013-09-01

    The hydrolytic activity of major endogenous proteases, responsible for proteolysis of myofibrillar proteins during post-mortem storage, may be an indicator of the textural quality of fish which influences consumer purchasing behaviour and thus market value of the final product. Furthermore, it may also influence the type and bioactive properties of the peptides released during post-mortem proteolysis of myofibrillar proteins. This study compared the activities of cathepsins B, B+L, D, H and calpain-like enzymes in crude muscle extracted from 16 Australian underutilized fish species. Fish species had a significant effect on the activity of these enzymes with barracouta showing the highest cathepsins B, B+L, D and H activities. Activities of cathepsins B and B+L were higher than cathepsin H for all studied species. The more commercially important rock ling and tiger flathead demonstrated higher cathepsin B+L activity, whereas gemfish and eastern school whiting showed higher activity towards cathepsin B. Underutilized fish species showing higher endogenous protease activities may be suitable for fish sauce production, whereas those with lower protease activities for surimi processing. Copyright © 2013 Elsevier Ltd. All rights reserved.

  9. Female social response to male sexual harassment in poeciliid fish: a comparison of six species

    Science.gov (United States)

    Dadda, Marco

    2015-01-01

    Sexual harassment is common among poeciliid fish. In some fishes, males show a high frequency of sneak copulation; such sexual activity is costly to the females in terms of foraging efficiency. In mosquitofish (Gambusia holbrooki), when males are present, the distance between females tends to decrease, and this behavior has been interpreted as an adaptive strategy to dilute the costs of male sexual activity. In this study, the tendency to reduce distance in the presence of a male has been investigated in females of six poeciliid species (Girardinus metallicus, Girardinus falcatus, G. holbrooki, Poecilia reticulata, Xiphophorus hellerii, and Xiphophorus mayae) that exhibit different male mating strategies and different levels of sexual activity. Results revealed large interspecific differences in the pattern of female aggregation. Females of species with a high frequency of sneak copulations tended to reduce their social distance in the presence of a male. By contrast, species that rely mainly on courtship showed little or no variation in social distance. The proportion of sneak copulations predicts the degree of variation in female social response, but the amount of total sexual activity does not, suggesting that the change in females' social distance when a male is present may indeed serve to reduce the costs of male sexual harassment. PMID:26483719

  10. Female social response to male sexual harassment in poeciliid fish: A comparison of six species

    Directory of Open Access Journals (Sweden)

    Marco eDadda

    2015-09-01

    Full Text Available Sexual harassment is common among poeciliid fish. In some fishes, males show a high frequency of sneak copulation; such sexual activity is costly to the females in terms of foraging efficiency. In mosquitofish (Gambusia holbrooki, when males are present, the distance between females tends to decrease, and this behavior has been interpreted as an adaptive strategy to dilute the costs of male sexual activity. In this study, the tendency to reduce distance in the presence of a male has been investigated in females of 6 poeciliid species (Girardinus metallicus, Girardinus falcatus, Gambusia holbrooki, Poecilia reticulata, Xiphophorus hellerii and Xiphophorus mayae that exhibit different male mating strategies and different levels of sexual activity. Results revealed large interspecific differences in the pattern of female aggregation. Females of species with a high frequency of sneak copulations tended to reduce their social distance in the presence of a male. By contrast, species that rely mainly on courtship showed little or no variation in social distance. The proportion of sneak copulations predicts the degree of variation in female social response, but the amount of total sexual activity does not, suggesting that the change in females’ social distance when a male is present may indeed serve to reduce the costs of male sexual harassment.

  11. Female social response to male sexual harassment in poeciliid fish: a comparison of six species.

    Science.gov (United States)

    Dadda, Marco

    2015-01-01

    Sexual harassment is common among poeciliid fish. In some fishes, males show a high frequency of sneak copulation; such sexual activity is costly to the females in terms of foraging efficiency. In mosquitofish (Gambusia holbrooki), when males are present, the distance between females tends to decrease, and this behavior has been interpreted as an adaptive strategy to dilute the costs of male sexual activity. In this study, the tendency to reduce distance in the presence of a male has been investigated in females of six poeciliid species (Girardinus metallicus, Girardinus falcatus, G. holbrooki, Poecilia reticulata, Xiphophorus hellerii, and Xiphophorus mayae) that exhibit different male mating strategies and different levels of sexual activity. Results revealed large interspecific differences in the pattern of female aggregation. Females of species with a high frequency of sneak copulations tended to reduce their social distance in the presence of a male. By contrast, species that rely mainly on courtship showed little or no variation in social distance. The proportion of sneak copulations predicts the degree of variation in female social response, but the amount of total sexual activity does not, suggesting that the change in females' social distance when a male is present may indeed serve to reduce the costs of male sexual harassment.

  12. Shape and Texture Based Classification of Fish Species

    DEFF Research Database (Denmark)

    Larsen, Rasmus; Ólafsdóttir, Hildur; Ersbøll, Bjarne Kjær

    2009-01-01

    In this paper we conduct a case study of ¯sh species classi- fication based on shape and texture. We consider three fish species: cod, haddock, and whiting. We derive shape and texture features from an appearance model of a set of training data. The fish in the training images were manual outlined......, and a few features including the eye and backbone contour were also annotated. From these annotations an optimal MDL curve correspondence and a subsequent image registration were derived. We have analyzed a series of shape and texture and combined shape and texture modes of variation for their ability...

  13. Genetic Analysis of Seed Yield Components and its Association with Forage Production in Wild and Cultivated Species of Sainfoin

    Directory of Open Access Journals (Sweden)

    A. Najafipoor

    2017-02-01

    Full Text Available Little is known about genetic variation of seed related traits and their association with forage characters in sainfoin. In order to investigate the variation and relationship among seed yield and its components, 93 genotypes from 21 wild and cultivated species of genus Onobrychis were evaluated using a randomized complete block design with four replications at Isfahan University of Technology Research Farm, Isfahan, Iran. Analysis of variance showed that there was significant difference among genotypes, indicating existence of considerable genetic variation in this germplasm. Panicle fertility and panicle length had the most variation in cultivated and the wild genotypes, respectively. Results of correlation analysis showed that seed yield was positively correlated with number of stems per plant and number of seeds per panicle and negatively correlated with panicle length and days to 50% flowering. Seed yield had positive correlation with forage yield in wild species while this correlation was not significant in cultivated one. Cluster analysis classified the genotypes into three groups which separate wild and cultivated species. Based on principal component analysis the first component was related to seed yield and the second one was related to components of forage yield which can be used for selection of high forage and seed yielding genotypes.

  14. MACROZOOBENTHOS OF MOUNTAIN RIVERS OF THE TRANSCARPATHIAN REGION AS A FORAGE BASE OF BENTHOPHAGOUS FISHES AND SAPROBITY INDICATOR

    Directory of Open Access Journals (Sweden)

    S. Kruzhylina

    2014-12-01

    Full Text Available Purpose. To study qualitative and qualitative indices of macrozoobenthos as one of main components of the forage base of benthophagous fishes in mountain river reaches of the Transcarpathian region and determination of their saprobity level. Methodology. Thhj,9.e study was carried out in summer period of 2009 in mountain river reaches of the Tisa river catchment. Zoobenthos samples were collected by a Surber sampler (25 × 25 cm on the bottoms of different fractions with different water flow rate (riffle, run, pool. Collection, processing and interpretation of the obtained data was carried out according to generally accepted hydrobiological methods developed for mountain river studies. Saprobity was of the studied rivers was calculated by Pantle-Buck formula. The Zelinka-Marvan saprobity index was used for calculations. Findings. Qualitative and quantitative macrozoobenthos indices have been studied. The number of zoobenthos on the investigated river sections ranged from 416 to 7712 ind./m2 with biomasses from 2.96 to 83.84 g/m2. The major portion of the zoobenthic biomass in the majority of rivers was due to caddis fly larvae composing up to 93% of the total biomass. An important role in the total biomass of the zoobenthos also belonged to mayfly (up to 53% and stonefly (up to 55% larvae and in lower degree amphipods (up to 39%, chironomid larvae (up to 14% and aquatic coleopterans (up to 5%. According to the calculated potential fish productivity, the mountain rivers can be apparently separated into three groups: little productive (4.2–12.7 kg/ha, medium productive (13.2–21.6 kg/ha and high productive (25.3–85.3 kg/ha. Mountain river reaches of the Transcarpathian region were found to belong to pure χ-saprobic, and о- і β-mesosaprobic zones, the saprobity index in which ranged from 0.35 (Rika river to 1.7 (Shipot river. Originality. For further calculation and assessment of brown trout (Salmo trutta and European grayling (Thymallus

  15. Productivity and recovery of forage fish under climate change and fishing: North Sea sandeel as a case study

    DEFF Research Database (Denmark)

    Lindegren, Martin; van Deurs, Mikael; MacKenzie, Brian

    2018-01-01

    -east Atlantic, acting as a key prey for predatory fish and sea birds, as well as supporting a large commercial fishery. In this case study, we investigate the underlying factors affecting recruitment and how these in turn affect productivity of the North Sea sandeel using long-term data and modelling. Our...... results demonstrate how sandeel productivity in the central North Sea (Dogger Bank) depends on a combination of external and internal regulatory factors, including fishing and climate effects, as well as density dependence and food availability of the preferred zooplankton prey (Calanus finmarchicus...... and Temora longicornis). Furthermore, our model scenarios suggest that while fishing largely contributed to the abrupt stock decline during the late 1990s and the following period of low biomass, a complete recovery of the stock to the highly productive levels of the early 1980s would only be possible...

  16. Fishing elevates variability in the abundance of exploited species.

    Science.gov (United States)

    Hsieh, Chih-Hao; Reiss, Christian S; Hunter, John R; Beddington, John R; May, Robert M; Sugihara, George

    2006-10-19

    The separation of the effects of environmental variability from the impacts of fishing has been elusive, but is essential for sound fisheries management. We distinguish environmental effects from fishing effects by comparing the temporal variability of exploited versus unexploited fish stocks living in the same environments. Using the unique suite of 50-year-long larval fish surveys from the California Cooperative Oceanic Fisheries Investigations we analyse fishing as a treatment effect in a long-term ecological experiment. Here we present evidence from the marine environment that exploited species exhibit higher temporal variability in abundance than unexploited species. This remains true after accounting for life-history effects, abundance, ecological traits and phylogeny. The increased variability of exploited populations is probably caused by fishery-induced truncation of the age structure, which reduces the capacity of populations to buffer environmental events. Therefore, to avoid collapse, fisheries must be managed not only to sustain the total viable biomass but also to prevent the significant truncation of age structure. The double jeopardy of fishing to potentially deplete stock sizes and, more immediately, to amplify the peaks and valleys of population variability, calls for a precautionary management approach.

  17. Accounting for Incomplete Species Detection in Fish Community Monitoring

    Energy Technology Data Exchange (ETDEWEB)

    McManamay, Ryan A [ORNL; Orth, Dr. Donald J [Virginia Polytechnic Institute and State University; Jager, Yetta [ORNL

    2013-01-01

    Riverine fish assemblages are heterogeneous and very difficult to characterize with a one-size-fits-all approach to sampling. Furthermore, detecting changes in fish assemblages over time requires accounting for variation in sampling designs. We present a modeling approach that permits heterogeneous sampling by accounting for site and sampling covariates (including method) in a model-based framework for estimation (versus a sampling-based framework). We snorkeled during three surveys and electrofished during a single survey in suite of delineated habitats stratified by reach types. We developed single-species occupancy models to determine covariates influencing patch occupancy and species detection probabilities whereas community occupancy models estimated species richness in light of incomplete detections. For most species, information-theoretic criteria showed higher support for models that included patch size and reach as covariates of occupancy. In addition, models including patch size and sampling method as covariates of detection probabilities also had higher support. Detection probability estimates for snorkeling surveys were higher for larger non-benthic species whereas electrofishing was more effective at detecting smaller benthic species. The number of sites and sampling occasions required to accurately estimate occupancy varied among fish species. For rare benthic species, our results suggested that higher number of occasions, and especially the addition of electrofishing, may be required to improve detection probabilities and obtain accurate occupancy estimates. Community models suggested that richness was 41% higher than the number of species actually observed and the addition of an electrofishing survey increased estimated richness by 13%. These results can be useful to future fish assemblage monitoring efforts by informing sampling designs, such as site selection (e.g. stratifying based on patch size) and determining effort required (e.g. number of

  18. Species specific anaesthetics for fish anaesthesia and euthanasia.

    Science.gov (United States)

    Readman, Gareth D; Owen, Stewart F; Knowles, Toby G; Murrell, Joanna C

    2017-08-02

    There is a need to ensure that the care and welfare for fish maintained in the laboratory are to the highest standards. This extends to the use of anaesthetics for both scientific study, humane killing and euthanasia at end of life. An anaesthetic should not induce negative behaviours and fish should not seek to avoid the anaesthetic. Surprisingly little information is available to facilitate a humane choice of anaesthetic agent for fish despite over 100 years of use and the millions of fish currently held in thousands of laboratories worldwide. Using a chemotaxic choice chamber we found different species specific behavioural responses among four closely related fish species commonly held in the laboratory, exposed to three widely used anaesthetic agents. As previously found for zebrafish (Danio rerio), the use of MS-222 and benzocaine also appears to induce avoidance behaviours in medaka (Oryzias latipes); but etomidate could provide an alternative choice. Carp (Cyprinus carpio), although closely related to zebrafish showed avoidance behaviours to etomidate, but not benzocaine or MS-222; and rainbow trout (Oncorhynchus mykiss) showed no avoidance to the three agents tested. We were unable to ascertain avoidance responses in fathead minnows (Pimephales promelas) and suggest different test paradigms are required for that species.

  19. Following a Foraging Fish-Finder: Diel Habitat Use of Blainville's Beaked Whales Revealed by Echolocation

    Science.gov (United States)

    Arranz, Patricia; de Soto, Natacha Aguilar; Madsen, Peter T.; Brito, Alberto; Bordes, Fernando; Johnson, Mark P.

    2011-01-01

    Simultaneous high resolution sampling of predator behavior and habitat characteristics is often difficult to achieve despite its importance in understanding the foraging decisions and habitat use of predators. Here we tap into the biosonar system of Blainville's beaked whales, Mesoplodon densirostris, using sound and orientation recording tags to uncover prey-finding cues available to echolocating predators in the deep-sea. Echolocation sounds indicate where whales search and encounter prey, as well as the altitude of whales above the sea-floor and the density of organisms around them, providing a link between foraging activity and the bio-physical environment. Tagged whales (n = 9) hunted exclusively at depth, investing most of their search time either in the lower part of the deep scattering layer (DSL) or near the sea-floor with little diel change. At least 43% (420/974) of recorded prey-capture attempts were performed within the benthic boundary layer despite a wide range of dive depths, and many dives included both meso- and bentho-pelagic foraging. Blainville's beaked whales only initiate searching when already deep in the descent and encounter prey suitable for capture within 2 min of the start of echolocation, suggesting that these whales are accessing prey in reliable vertical strata. Moreover, these prey resources are sufficiently dense to feed the animals in what is effectively four hours of hunting per day enabling a strategy in which long dives to exploit numerous deep-prey with low nutritional value require protracted recovery periods (average 1.5 h) between dives. This apparent searching efficiency maybe aided by inhabiting steep undersea slopes with access to both the DSL and the sea-floor over small spatial scales. Aggregations of prey in these biotopes are located using biosonar-derived landmarks and represent stable and abundant resources for Blainville's beaked whales in the otherwise food-limited deep-ocean. PMID:22163295

  20. Following a foraging fish-finder: diel habitat use of Blainville's beaked whales revealed by echolocation.

    Directory of Open Access Journals (Sweden)

    Patricia Arranz

    Full Text Available Simultaneous high resolution sampling of predator behavior and habitat characteristics is often difficult to achieve despite its importance in understanding the foraging decisions and habitat use of predators. Here we tap into the biosonar system of Blainville's beaked whales, Mesoplodon densirostris, using sound and orientation recording tags to uncover prey-finding cues available to echolocating predators in the deep-sea. Echolocation sounds indicate where whales search and encounter prey, as well as the altitude of whales above the sea-floor and the density of organisms around them, providing a link between foraging activity and the bio-physical environment. Tagged whales (n = 9 hunted exclusively at depth, investing most of their search time either in the lower part of the deep scattering layer (DSL or near the sea-floor with little diel change. At least 43% (420/974 of recorded prey-capture attempts were performed within the benthic boundary layer despite a wide range of dive depths, and many dives included both meso- and bentho-pelagic foraging. Blainville's beaked whales only initiate searching when already deep in the descent and encounter prey suitable for capture within 2 min of the start of echolocation, suggesting that these whales are accessing prey in reliable vertical strata. Moreover, these prey resources are sufficiently dense to feed the animals in what is effectively four hours of hunting per day enabling a strategy in which long dives to exploit numerous deep-prey with low nutritional value require protracted recovery periods (average 1.5 h between dives. This apparent searching efficiency maybe aided by inhabiting steep undersea slopes with access to both the DSL and the sea-floor over small spatial scales. Aggregations of prey in these biotopes are located using biosonar-derived landmarks and represent stable and abundant resources for Blainville's beaked whales in the otherwise food-limited deep-ocean.

  1. DEVELOPMENT OF TECHNOLOGY FOR FISH CANNED PATE'S COD-FISH SPECIES

    Directory of Open Access Journals (Sweden)

    A. A. Efremova

    2014-01-01

    Full Text Available Summary. Fish and seafood play an important role in a balanced diet. The most reliable method of preservation is the production of canned fish. Cod fishery considered traditional objects of the North Basin, which catches in recent years stored at a consistently high level. They are represented, mainly cod, haddock, pollack, whiting. Lately there has been a tendency to increase yield loaves (polar bib. The aim of this work - the development of technology - canned pate's cod fish species with the addition of plant materials. We used the adopted research microbiological, chemical and physical methods. The weight proportion of water, lipids, protein, mineral raw determined according to State standard 7636-85. Developed a technology - canned pate's cod fish species with the addition of plant materials. Optimized formulation is set to sterilization. Experimentally determined parameters of quality canned and given comprehensive assessment nutritional value of new products, organoleptic, physico-chemical, biochemical and microbiological tests showed that canned pates of Gadidae species of fish with vegetables, meet all safety requirements and are characterized, along with excellent consumer properties, high nutritional value. Based on the results of the research complex developed technical documentation for production of canned vegetables, pates of Gadidae species.

  2. SNP Discovery In Marine Fish Species By 454 Sequencing

    DEFF Research Database (Denmark)

    Panitz, Frank; Nielsen, Rasmus Ory; van Houdt, Jeroen K J

    2011-01-01

    Based on the 454 Next-Generation-Sequencing technology (Roche) a high throughput screening method was devised in order to generate novel genetic markers (SNPs). SNP discovery was performed for three target species of marine fish: hake (Merluccius merluccius), herring (Clupea harengus) and sole...

  3. Feeding ecology of three inshore fish species at Marion Island ...

    African Journals Online (AJOL)

    Three species of fish occur in the shallow inshore waters of Marion Island. Notothenia ... and then expressed as a percentage of the sum of all R.1. values for each ... also spends much of its time lying motionless on the bot- tom. Up to three H.

  4. Fish species composition and abundance on a subtropical, artificial ...

    African Journals Online (AJOL)

    The composition and abundance of fish species on a derelict rocky pier on the Durban beachfront, KwaZulu-. Natal, South Africa, were assessed by means of underwater visual census, using transects. A total of 74 spe- cies were recorded on the reef, with convict surgeons (Acanthurus triostegus), sash damsels ...

  5. Otolith Length-Fish Length Relationships of Eleven US Arctic Fish Species and Their Application to Ice Seal Diet Studies

    Science.gov (United States)

    Walker, K. L.; Norcross, B.

    2016-02-01

    The Arctic ecosystem has moved into the spotlight of scientific research in recent years due to increased climate change and oil and gas exploration. Arctic fishes and Arctic marine mammals represent key parts of this ecosystem, with fish being a common part of ice seal diets in the Arctic. Determining sizes of fish consumed by ice seals is difficult because otoliths are often the only part left of the fish after digestion. Otolith length is known to be positively related to fish length. By developing species-specific otolith-body morphometric relationships for Arctic marine fishes, fish length can be determined for fish prey found in seal stomachs. Fish were collected during ice free months in the Beaufort and Chukchi seas 2009 - 2014, and the most prevalent species captured were chosen for analysis. Otoliths from eleven fish species from seven families were measured. All species had strong linear relationships between otolith length and fish total length. Nine species had coefficient of determination values over 0.75, indicating that most of the variability in the otolith to fish length relationship was explained by the linear regression. These relationships will be applied to otoliths found in stomachs of three species of ice seals (spotted Phoca largha, ringed Pusa hispida, and bearded Erignathus barbatus) and used to estimate fish total length at time of consumption. Fish lengths can in turn be used to calculate fish weight, enabling further investigation into ice seal energetic demands. This application will aid in understanding how ice seals interact with fish communities in the US Arctic and directly contribute to diet comparisons among and within ice seal species. A better understanding of predator-prey interactions in the US Arctic will aid in predicting how ice seal and fish species will adapt to a changing Arctic.

  6. Expression levels of parvalbumins determine allergenicity of fish species.

    Science.gov (United States)

    Griesmeier, U; Vázquez-Cortés, S; Bublin, M; Radauer, C; Ma, Y; Briza, P; Fernández-Rivas, M; Breiteneder, H

    2010-02-01

    Parvalbumins are the most important fish allergens. Polysensitization to various fish species is frequently reported and linked to the cross-reactivity of their parvalbumins. Studies on cross-reactivity and its association to the allergenicity of purified natural parvalbumins from different fish species are still lacking. In addition, some studies indicate that dark muscled fish such as tuna are less allergenic. Total protein extracts and purified parvalbumins from cod, whiff, and swordfish, all eaten frequently in Spain, were tested for their IgE-binding properties with 16 fish allergic patients' sera from Madrid. The extent of cross-reactivity of these parvalbumins was investigated by IgE ELISA inhibition assays. Additionally, the cDNA sequences of whiff and swordfish parvalbumins were determined. Extractable amounts of parvalbumins from cod were 20 times and from whiff 30 times higher than from swordfish. Parvalbumins were recognized by 94% of the patients in extracts of cod and whiff, but only by 60% in swordfish extracts. Nevertheless, a high cross-reactivity was determined for all purified parvalbumins by IgE inhibition. The amino acid sequence identities of the three parvalbumins were in a range of 62-74%. The parvalbumins of cod, whiff and swordfish are highly cross-reactive. The high amino acid sequence identity among cod, whiff and swordfish parvalbumins results in the observed IgE cross-reactivity. The low allergenicity of swordfish is due to the low expression levels of its parvalbumin.

  7. Liquid chromatographic determination of oxytetracycline in edible fish fillets from six species of fish

    Science.gov (United States)

    Meinertz, J.R.; Stehly, G.R.; Gingerich, W.H.

    1998-01-01

    The approved use of oxytetracycline (OTC) in U.S. Aquaculture is limited to specific diseases in salmonids and channel catfish. OTC may also be effective in controlling diseases in other fish species important to public aquaculture, but before approved use of OTC can be augmented, an analytical method for determining OTC in fillet tissue from multiple species of fish will be required to support residue depletion studies. The objective of this study was to develop and validate a liquid chromatographic (LC) method that is accurate, precise, and sensitive for OTC in edible fillets from multiple species of fish. Homogenized fillet tissues from walleye, Atlantic salmon, striped bass, white sturgeon, rainbow trout, and channel catfish were fortified with OTC at nominal concentrations of 10, 20, 100, 1000, and 5000 ng/g. In tissues fortified with OTC at 100, 1000, and 5000 ng/g, mean recoveries ranged from 83 to 90%, and relative standard deviations (RSDs) ranged from 0.9 to 5.8%. In all other tissues, mean recoveries ranged from 59 to 98%, and RSDs ranged from 3.3 to 20%. Method quantitation limits ranged from 6 to 22 ng/g for the 6 species. The LC parameters produced easily integratable OTC peaks without coelution of endogenous compounds. The method is accurate, precise, and sensitive for OTC in fillet tissue from 6 species of fish from 5 phylogenetically diverse groups.

  8. PIXE analysis of otoliths from several species of teleost fish

    International Nuclear Information System (INIS)

    Arai, Nobuaki; Sakamoto, Wataru; Maeda, Kuniko.

    1994-01-01

    In-air PIXE was used to analyze trace elements in otoliths from several species of teleost fish in order to examine the correlation between the trace elements concentrations and environmental conditions. Mn, Fe, Zn and Sr were detected accurately in the order of ppm by using the in-air PIXE. It seemed that concentrations of Sr and Zn in red sea bream otoliths increased in proportion to higher seawater temperature. In addition, there were significant differences in trace element composition between that of reared red sea bream and rockfish and that of wild ones. Preliminary results indicate that the PIXE is a powerful technique to investigate fish otoliths. (author)

  9. Development of Solar Drying Model for Selected Cambodian Fish Species

    OpenAIRE

    Hubackova, Anna; Kucerova, Iva; Chrun, Rithy; Chaloupkova, Petra; Banout, Jan

    2014-01-01

    A solar drying was investigated as one of perspective techniques for fish processing in Cambodia. The solar drying was compared to conventional drying in electric oven. Five typical Cambodian fish species were selected for this study. Mean solar drying temperature and drying air relative humidity were 55.6°C and 19.9%, respectively. The overall solar dryer efficiency was 12.37%, which is typical for natural convection solar dryers. An average evaporative capacity of solar dryer was 0.049 kg·h...

  10. Legumes and forage species sole or intercropped with corn in soybean-corn succession in midwestern Brazil

    Directory of Open Access Journals (Sweden)

    Gessí Ceccon

    2013-02-01

    Full Text Available The feasibility of no-tillage in the Cerrado (Savanna-like vegetation of Brazil depends on the production of sufficient above-ground crop residue, which can be increased by corn-forage intercropping. This study evaluated how above-ground crop residue production and yields of soybean and late-season corn in a soybean-corn rotation were influenced by the following crops in the year before soybean: corn (Zea mays L. intercropped with Brachiaria (Urochloa brizantha cv. Marandu, B. decumbens cv. Basilisk, B. ruziziensis, cv. comum., Panicummaximum cv. Tanzânia, sunn hemp (Crotalaria juncea L., pigeon pea [Cajanus cajan (L. Millsp]; sole corn, forage sorghum [Sorghum bicolor (L. Moench (cv. Santa Elisa], and ruzi grass. In March 2005, corn and forage species were planted in alternate rows spaced 0.90 m apart, and sole forage species were planted in rows spaced 0.45 m apart. In October 2005, the forages were killed with glyphosate and soybean was planted. After the soybean harvest in March 2006, sole late-season corn was planted in the entire experimental area. Corn grain and stover yields were unaffected by intercropping. Above-ground crop residue was greater when corn was intercropped with Tanzania grass (10.7 Mg ha-1, Marandu (10.1 Mg ha-1, and Ruzi Grass (9.8 Mg ha-1 than when corn was not intercropped (4.0 Mg ha-1. The intercropped treatments increased the percentage of soil surface covered with crop residue. Soybean and corn grain yields were higher after sole ruzi grass and intercropped ruzi grass than after other crops. The intercropping corn with Brachiaria spp. and corn with Panicum spp. increases above-ground crop residue production and maintains nutrients in the soil without reducing late-season corn yield and the viability of no-till in the midwestern region of Brazil.

  11. Alley cropping of legumes with grasses as forages : Effect of different grass species and row spacing of gliricidia on the growth and biomass production of forages

    Directory of Open Access Journals (Sweden)

    Siti Yuhaeni

    1998-12-01

    Full Text Available A study to evaluate the effect of different grass species and row spacing of gliricidia (Gliricidia sepium on the growth and biomass production of forages in an alley cropping system was conducted in two different agroclimatical zones i.e. Bogor, located at 500 m a .s .l . with an average annual rainfall of 3,112 nun/year and Sukabumi located at 900 m a .s .l . with an average annual rainfall of 1,402 mm/year . Both locations have low N, P, and K content and the soil is classified as acidic. The experimental design used was a split plot design with 3 replicates . The main plots were different grass species i.e. king grass (Pennisetum purpureum x P. typhoides and elephant grass (P. purpureum. The sub plots were the row spacing of gliricidia at 2, 3, 4, 6 m (1 hedgerows and 4 m (2 hedgerows. The results indicated that the growth and biomass production of grasses were significantly affected (P<0 .05 by the treatments in Bogor. The highest biomass productions was obtained from the 2 m row spacing which gave the highest dry matter production of grasses (1 .65 kg/hill and gliricidia (0 .086 kg/tree . In Sukabumi the growth and biomass production of grasses and gliricidia were also significantly affected by the treatments . The highest dry matter production was obtained with 2 m row spacing (dry matter of grasses and gliricidia were 1 .12 kg/hill and 0 .026 kg/tree, respectively . The result further indicated that biomass production of forages increased with the increase in gliricidia population. The alley cropping system wich is suitable for Bogor was the 2 m row spacing of gliricidia intercropped with either king or elephant grass and for Sukabumi 2 and 4 m (2 rows of gliricidia row spacing intercropped with king or elephant grass .

  12. 76 FR 2663 - Endangered and Threatened Species; Take of Anadromous Fish

    Science.gov (United States)

    2011-01-14

    ... and Threatened Species; Take of Anadromous Fish AGENCY: National Marine Fisheries Service (NMFS... and steelhead, and natural juvenile green sturgeon while carrying out a study measuring fish response... species, taking of length measurements), tissue sampling, release of moribund fish or fish carcasses back...

  13. Enhanced invertebrate prey production following estuarine restoration supports foraging for multiple species of juvenile salmonids (Oncorhynchus spp.)

    Science.gov (United States)

    Woo, Isa; Davis, Melanie; Ellings, Christopher S.; Nakai, Glynnis; Takekawa, John Y.; De La Cruz, Susan

    2018-01-01

    Estuaries provide crucial foraging resources and nursery habitat for threatened populations of anadromous salmon. As such, there has been a global undertaking to restore habitat and tidal processes in modified estuaries. The foraging capacity of these ecosystems to support various species of out-migrating juvenile salmon can be quantified by monitoring benthic, terrestrial, and pelagic invertebrate prey communities. Here, we present notable trends in the availability of invertebrate prey at several sites within a restoring large river delta in Puget Sound, Washington, U.S.A. Three years after the system was returned to tidal influence, we observed substantial additions to amphipod, copepod, and cumacean abundances in newly accessible marsh channels (from 0 to roughly 5,000–75,000 individuals/m2). In the restoration area, terrestrial invertebrate colonization was dependent upon vegetative cover, with dipteran and hymenopteran biomass increasing 3-fold between 1 and 3 years post-restoration. While the overall biodiversity within the restoration area was lower than in the reference marsh, estimated biomass was comparable to or greater than that found within the other study sites. This additional prey biomass likely provided foraging benefits for juvenile Chinook, chum, and coho salmon. Primary physical drivers differed for benthic, terrestrial, and pelagic invertebrates, and these invertebrate communities are expected to respond differentially depending on organic matter exchange and vegetative colonization. Restoring estuaries may take decades to meet certain success criteria, but our study demonstrates rapid enhancements in foraging resources understood to be used for estuary-dependent wildlife.

  14. Movement patterns for a critically endangered species, the leatherback turtle (Dermochelys coriacea, linked to foraging success and population status.

    Directory of Open Access Journals (Sweden)

    Helen Bailey

    Full Text Available Foraging success for pelagic vertebrates may be revealed by horizontal and vertical movement patterns. We show markedly different patterns for leatherback turtles in the North Atlantic versus Eastern Pacific, which feed on gelatinous zooplankton that are only occasionally found in high densities. In the Atlantic, travel speed was characterized by two modes, indicative of high foraging success at low speeds (<15 km d(-1 and transit at high speeds (20-45 km d(-1. Only a single mode was evident in the Pacific, which occurred at speeds of 21 km d(-1 indicative of transit. The mean dive depth was more variable in relation to latitude but closer to the mean annual depth of the thermocline and nutricline for North Atlantic than Eastern Pacific turtles. The most parsimonious explanation for these findings is that Eastern Pacific turtles rarely achieve high foraging success. This is the first support for foraging behaviour differences between populations of this critically endangered species and suggests that longer periods searching for prey may be hindering population recovery in the Pacific while aiding population maintenance in the Atlantic.

  15. 75 FR 2106 - Endangered and Threatened Species; Take of Anadromous Fish

    Science.gov (United States)

    2010-01-14

    ... and Threatened Species; Take of Anadromous Fish AGENCY: National Marine Fisheries Service (NMFS... NMFS regulations (50 CFR parts 222-226) governing listed fish and wildlife permits. Species Covered in... steelhead not to exceed 2 percent of the total number of fish captured for each life stage and species...

  16. 76 FR 27017 - Endangered and Threatened Species; Take of Anadromous Fish

    Science.gov (United States)

    2011-05-10

    ... FURTHER INFORMATION CONTACT: Garth Griffin, Portland, OR, ph.: 503- 231-2005, Fax: 503-230-5441, e-mail... Snohomish River estuary, and Shilshole Bay, Washington. The goal of these projects is to understand changes....g., trophic web effects, plant and animal community dynamics, and forage fish population...

  17. 76 FR 14923 - Endangered and Threatened Species; Take of Anadromous Fish

    Science.gov (United States)

    2011-03-18

    ... and Threatened Species; Take of Anadromous Fish AGENCY: National Marine Fisheries Service (NMFS... knowledge of species listed under the Endangered Species Act (ESA) and help guide management and... harvested groundfish species. The survey would collect data on 90+ fish species in the ocean to fulfill the...

  18. DNA barcoding commercially important fish species of Turkey.

    Science.gov (United States)

    Keskın, Emre; Atar, Hasan H

    2013-09-01

    DNA barcoding was used in the identification of 89 commercially important freshwater and marine fish species found in Turkish ichthyofauna. A total of 1765 DNA barcodes using a 654-bp-long fragment of the mitochondrial cytochrome c oxidase subunit I gene were generated for 89 commercially important freshwater and marine fish species found in Turkish ichthyofauna. These species belong to 70 genera, 40 families and 19 orders from class Actinopterygii, and all were associated with a distinct DNA barcode. Nine and 12 of the COI barcode clusters represent the first species records submitted to the BOLD and GenBank databases, respectively. All COI barcodes (except sequences of first species records) were matched with reference sequences of expected species, according to morphological identification. Average nucleotide frequencies of the data set were calculated as T = 29.7%, C = 28.2%, A = 23.6% and G = 18.6%. Average pairwise genetic distance among individuals were estimated as 0.32%, 9.62%, 17,90% and 22.40% for conspecific, congeneric, confamilial and within order, respectively. Kimura 2-parameter genetic distance values were found to increase with taxonomic level. For most of the species analysed in our data set, there is a barcoding gap, and an overlap in the barcoding gap exists for only two genera. Neighbour-joining trees were drawn based on DNA barcodes and all the specimens clustered in agreement with their taxonomic classification at species level. Results of this study supported DNA barcoding as an efficient molecular tool for a better monitoring, conservation and management of fisheries. © 2013 John Wiley & Sons Ltd.

  19. Anticholinesterase effect of eserine (physostigmine in fish and crustacean species

    Directory of Open Access Journals (Sweden)

    Monserrat José M.

    2001-01-01

    Full Text Available The kinetic characteristic (Km of cholinesterase from the crab Chasmagnathus granulata, the shrimp Farfantepenaeus paulensis and the fish Odontesthes bonaeriensis were compared and correlated with the anticholinesterasic effect of eserine (physostigmine. For the crustaceans, the estimated Km values were about 5-8 times higher than that estimated for the fish (0.04 mM. In the crab and the shrimp, the concentration of eserine which inhibited 50% of cholinesterase activity (IC50 was estimated as 5.33x10-4 and 4.33x10-4 mM, respectively. In both cases, it was significantly higher (P < 0.05 than that estimated for the fish larvae (7.43x10-5 mM. A high Km could reflect a lower affinity of the cholinesterase for its natural substrate, acetylcholine, or for substrate analogues such as carbamates and organophosphorous pesticides. If we consider the IC50 for eserine as an index of enzyme susceptibility to pesticide inhibition, the cholinesterase from the fish larvae may be a better useful tool in assays for pesticide biomonitoring than that from crustacean species.

  20. Effects of recreational fishing on three fish species from the Posidonia oceanica meadows off Minorca (Balearic archipelago, western Mediterranean

    Directory of Open Access Journals (Sweden)

    Luis Cardona

    2007-12-01

    Full Text Available Experimental fishing and visual censuses were conducted at nine Posidonia oceanica sites off Minorca exposed to different levels of fishing intensity to assess the effects of recreational fishing on the species that dominate the catch. Total catch per unit effort (CPUE was highly seasonal and a statistically significant interaction term existed between the season and the level of fishing intensity. CPUE decreased everywhere at the end of the fishing season (autumn, but such a reduction was more intense at those sites exposed to the highest level of fishing. Visual censuses confirmed that there was a lower abundance of vulnerable fish in autumn. Differences vanished in spring probably because fish reshuffled between the considered sites throughout the winter, when the level of fishing intensity was extremely low. Although the average total lengths of Serranus scriba and Diplodus annularis were unaffected by the level of fishing intensity, the average total length of Coris julis was smaller at the most heavily fished sites. In conclusion, recreational fishing has a relevant impact on most of the exploited species and some of the seasonality reported for the Posidonia oceanica fish assemblages might be caused by the seasonality of the fishery.

  1. Preliminary list of endangered fish species (Pisces, Elasmobranchii , Actinopterygii) in Brazil

    OpenAIRE

    Rosa, Ricardo S; Menezes, Naércio A

    1996-01-01

    The Brazilian fish fauna is still poorly known with respect to its diversity and conservation status, particularly of freshwater species. Human activities and population growth are rapidly impacting this fauna to an unchecked extent, so that many fish species are presently threatened. Also, some areas have been so critically altered that their fish fauna can no longer be properly inventoried. There is an urgent need to evaluate the conservation status of Brazilian fish species, since none are...

  2. Levels of Mercury in Persian Gulf Frozen Fish Species

    Directory of Open Access Journals (Sweden)

    Parisa Ziarati

    2017-03-01

    Full Text Available Severe discharge of sewage and industrial effluents into the Persian Gulf leads to the deposition of various types of heavy metals, especially lead and mercury, in the muscles of fish. Total mercury and methylmercury contents were determined in the edible parts (muscle tissue, fillet of two different most popular frozen fish species from the Persian Gulf to ascertain whether the concentrations exceeded the maximum level fixed by the European Commission or not. During the period from October 2015 to June 2016, a total of 150 frozen fish packaged samples were randomly collected from the recognized supermarkets in Tehran province, Iran. The mercury (Hg concentration of samples was determined by atomic absorption spectrophotometer using a mercuric hydride system (MHS 10 and also by direct mercury analyzer (DMA. High concentration of total Hg was found in a Carcharhinus dussumie brand (0.91 ± 0.12 μg/g while the lowest level was detected in Pomadasys furcatus (0.29 ± 0.02 μg/g. In current study the mean concentrations of Mercury in all studied frozen fish samples were 0.79 ± 0.11 µg/g that means Hg levels were above 0.5 μg/g, which is the maximum standard level recommended by Joint FAO/WHO/Expert Committee on Food Additives (JECFA. In 13% of Pomadasys and in 47.2 % of Carcharhinus fish samples total mercury concentrations exceeded the maximum level fixed by the European Commission. All samples had also mean Hg concentrations that exceeded EPA's established safety level of 0.3 μg/g.

  3. possible stimuli for social behaviour in three species of freshwater fish

    African Journals Online (AJOL)

    Social behaviour in fish is manifested in many situations and one form. of this phenomenon is especially interesting. Some species of fish have .... Experi- mental methods of study of fish behaviour, in Techniques lor the Investigation 0/ Fish. Physiology, ed. Pavlovskii, E. N., Oldbourne. Press, London. R ep rod u ced b y Sa b.

  4. 78 FR 59005 - Endangered and Threatened Species; Take of Anadromous Fish

    Science.gov (United States)

    2013-09-25

    ... and Threatened Species; Take of Anadromous Fish AGENCY: National Marine Fisheries Service (NMFS... with Section 10(a)(1)(A) of the ESA of 1973 (16 U.S.C. 1531-1543) and regulations governing listed fish.... Applications Received Permit 1415 The U.S. Fish and Wildlife Services' (USFWS) Red Bluff Fish and Wildlife...

  5. 78 FR 74116 - Endangered and Threatened Species; Take of Anadromous Fish

    Science.gov (United States)

    2013-12-10

    ... and Threatened Species; Take of Anadromous Fish AGENCY: National Marine Fisheries Service (NMFS... plans and request for comment. SUMMARY: Notice is hereby given that the Oregon Department of Fish and... River and Columbia River basins by providing hatchery fish to support fishing opportunities while...

  6. 77 FR 51520 - Endangered and Threatened Species; Take of Anadromous Fish

    Science.gov (United States)

    2012-08-24

    ... and Threatened Species; Take of Anadromous Fish AGENCY: National Marine Fisheries Service (NMFS... (16 U.S.C. 1531-1543) and regulations governing listed fish and wildlife permits (50 CFR parts 222-226... expect to kill any listed fish but a small number, up to 20 percent (equivalent to one fish), may die as...

  7. Foraging in corallivorous butterflyfish varies with wave exposure

    Science.gov (United States)

    Noble, Mae M.; Pratchett, Morgan S.; Coker, Darren J.; Cvitanovic, Christopher; Fulton, Christopher J.

    2014-06-01

    Understanding the foraging patterns of reef fishes is crucial for determining patterns of resource use and the sensitivity of species to environmental change. While changes in prey availability and interspecific competition have been linked to patterns of prey selection, body condition, and survival in coral reef fishes, rarely has the influence of abiotic environmental conditions on foraging been considered. We used underwater digital video to explore how prey availability and wave exposure influence the behavioural time budgets and prey selectivity of four species of obligate coral-feeding butterflyfishes. All four species displayed high selectivity towards live hard corals, both in terms of time invested and frequency of searching and feeding events. However, our novel analysis revealed that such selectivity was sensitive to wave exposure in some species, despite there being no significant differences in the availability of each prey category across exposures. In most cases, these obligate corallivores increased their selectivity towards their most favoured prey types at sites of high wave exposure. This suggests there are costs to foraging under different wave environments that can shape the foraging patterns of butterflyfishes in concert with other conditions such as prey availability, interspecific competition, and territoriality. Given that energy acquisition is crucial to the survival and fitness of fishes, we highlight how such environmental forcing of foraging behaviour may influence the ecological response of species to the ubiquitous and highly variable wave climates of shallow coral reefs.

  8. Specific IgE to fish extracts does not predict allergy to specific species within an adult fish allergic population.

    Science.gov (United States)

    Schulkes, Karlijn Jg; Klemans, Rob Jb; Knigge, Lidy; de Bruin-Weller, Marjolein; Bruijnzeel-Koomen, Carla Afm; Marknell deWitt, Asa; Lidholm, Jonas; Knulst, André C

    2014-01-01

    Fish is an important cause of food allergy. Studies on fish allergy are scarce and in most cases limited to serological evaluation. Our objective was to study patterns of self-reported allergy and tolerance to different commonly consumed fish species and its correlation to IgE sensitization to the same species. Thirty-eight adult fish allergic patients completed a questionnaire regarding atopy, age of onset and symptoms to 13 commonly consumed fish species in the Netherlands (pangasius, cod, herring, eel, hake, pollock, mackerel, tilapia, salmon, sardine, tuna, plaice and swordfish). Specific IgE to these fish extracts were analyzed by ImmunoCAP. Median age of onset of fish allergy was 8.5 years. Severe reactions were reported by the majority of patients (n = 20 (53%) respiratory and of these 20 patients, 6 also had cardiovascular symptoms). After diagnosis, 66% of the patients had eliminated all fish from their diet. Allergy to all species ever tried was reported by 59%. In relation to species ever tried, cod (84%) and herring (79%) were the most frequently reported culprit species while hake (57%) and swordfish (55%) were the least frequent. A positive sIgE (value ≥ 0.35 kUA/L) to the culprit species ranged between 50% (swordfish) and 100% (hake). In tolerant patients, a negative sIgE (value allergy or tolerance was 82% and 25%, respectively. Sensitization to cod parvalbumin (Gad c 1) was present in 77% of all patients. Serological cross-reactivity between fish species is frequent, but in a significant proportion of patients, clinical relevance appears to be limited to only certain species. A well-taken history or food challenge is required for discrimination between allergy to the different fish species.

  9. Foraging behavior and success of a mesopelagic predator in the northeast Pacific Ocean: insights from a data-rich species, the northern elephant seal.

    Directory of Open Access Journals (Sweden)

    Patrick W Robinson

    Full Text Available The mesopelagic zone of the northeast Pacific Ocean is an important foraging habitat for many predators, yet few studies have addressed the factors driving basin-scale predator distributions or inter-annual variability in foraging and breeding success. Understanding these processes is critical to reveal how conditions at sea cascade to population-level effects. To begin addressing these challenging questions, we collected diving, tracking, foraging success, and natality data for 297 adult female northern elephant seal migrations from 2004 to 2010. During the longer post-molting migration, individual energy gain rates were significant predictors of pregnancy. At sea, seals focused their foraging effort along a narrow band corresponding to the boundary between the sub-arctic and sub-tropical gyres. In contrast to shallow-diving predators, elephant seals target the gyre-gyre boundary throughout the year rather than follow the southward winter migration of surface features, such as the Transition Zone Chlorophyll Front. We also assessed the impact of added transit costs by studying seals at a colony near the southern extent of the species' range, 1,150 km to the south. A much larger proportion of seals foraged locally, implying plasticity in foraging strategies and possibly prey type. While these findings are derived from a single species, the results may provide insight to the foraging patterns of many other meso-pelagic predators in the northeast Pacific Ocean.

  10. 76 FR 27016 - Endangered and Threatened Species; Take of Anadromous Fish

    Science.gov (United States)

    2011-05-10

    ... and Threatened Species; Take of Anadromous Fish AGENCY: National Marine Fisheries Service (NMFS... increase knowledge of species listed under the Endangered Species Act (ESA) and help guide management and... during the species' upstream migration. Captured fish would be transported in a tanker truck and released...

  11. 78 FR 28806 - Endangered and Threatened Species; Take of Anadromous Fish

    Science.gov (United States)

    2013-05-16

    ... and Threatened Species; Take of Anadromous Fish AGENCY: National Marine Fisheries Service (NMFS... Resources (CDWR), Permit 17428 to the United States Fish and Wildlife Service (USFWS), and Permit 17777 to... NMFS regulations (50 CFR parts 222-226) governing listed fish and wildlife permits. Species Covered in...

  12. Comparative analysis of diet composition and its relation to morphological characteristics in juvenile fish of three lutjanid species in a Mexican Pacific coastal lagoon

    Directory of Open Access Journals (Sweden)

    Consuelo M. Aguilar-Betancourt

    2017-12-01

    Full Text Available ABSTRACT The main goal of this research was to investigate the differences in diet composition among three species of the genus Lutjanus inhabiting a coastal lagoon as juveniles. The working hypothesis was that these species feed on a common base of food resources and therefore, some niche overlap is present in terms of general diet composition. However, changes in the trophic niche with size and differences in some morphological traits among species explain observed differences in diet. Fish were collected during 42 sampling trips conducted regularly from February 2011 to January 2012 using several types of fishing gear. Total number of analyzed stomachs was 288 for Lutjanus argentiventris from 2.3 to 19.9 cm total length (TL; 178 for Lutjanus colorado ranging from 2.4 to 30.1 cm TL; and 183 for Lutjanus novemfasciatus with 1.2 to 20.0 cm TL. Results indicate that juveniles of all three lutjanid species share a general diet based on decapods and fishes. However, L. novemfasciatus has a more piscivorous habit, which can be explained by a more slender body shape and larger teeth, characteristics, which increase fish catching performance. Larger fish of all three species eat larger prey, which is consistent with the optimum foraging theory.

  13. Metazoan parasite species richness in Neotropical fishes: hotspots and the geography of biodiversity.

    Science.gov (United States)

    Luque, J L; Poulin, R

    2007-06-01

    Although research on parasite biodiversity has intensified recently, there are signs that parasites remain an underestimated component of total biodiversity in many regions of the planet. To identify geographical hotspots of parasite diversity, we performed qualitative and quantitative analyses of the parasite-host associations in fishes from Latin America and the Caribbean, a region that includes known hotspots of plant and animal biodiversity. The database included 10,904 metazoan parasite-host associations involving 1660 fish species. The number of host species with at least 1 parasite record was less than 10% of the total known fish species in the majority of countries. Associations involving adult endoparasites in actinopterygian fish hosts dominated the database. Across the whole region, no significant difference in parasite species richness was detected between marine and freshwater fishes. As a rule, host body size and study effort (number of studies per fish species) were good predictors of parasite species richness. Some interesting patterns emerged when we included only the regions with highest fish species biodiversity and study effort (Brazil, Mexico and the Caribbean Islands). Independently of differences in study effort or host body sizes, Mexico stands out as a hotspot of parasite diversity for freshwater fishes, as does Brasil for marine fishes. However, among 57 marine fish species common to all 3 regions, populations from the Caribbean consistently harboured more parasite species. These differences may reflect true biological patterns, or regional discrepancies in study effort and local priorities for fish parasitology research.

  14. Plant species composition alters the sign and strength of an emergent multi-predator effect by modifying predator foraging behaviour.

    Directory of Open Access Journals (Sweden)

    Andrew Wilby

    Full Text Available The prediction of pest-control functioning by multi-predator communities is hindered by the non-additive nature of species functioning. Such non-additivity, commonly termed an emergent multi-predator effect, is known to be affected by elements of the ecological context, such as the structure and composition of vegetation, in addition to the traits of the predators themselves. Here we report mesocosm experiments designed to test the influence of plant density and species composition (wheat monoculture or wheat and faba bean polyculture on the emergence of multi-predator effects between Adalia bipunctata and Chrysoperla carnea, in their suppression of populations of the aphid Metopolophium dirhodum. The mesocosm experiments were followed by a series of behavioural observations designed to identify how interactions among predators are modified by plant species composition and whether these effects are consistent with the observed influence of plant species composition on aphid population suppression. Although plant density was shown to have no influence on the multi-predator effect on aphid population growth, plant composition had a marked effect. In wheat monoculture, Adalia and Chrysoperla mixed treatments caused greater suppression of M. dirhodum populations than expected. However this positive emergent effect was reversed to a negative multi-predator effect in wheat and faba bean polyculture. The behavioural observations revealed that although dominant individuals did not respond to the presence of faba bean plants, the behaviour of sub-dominants was affected markedly, consistent with their foraging for extra-floral nectar produced by the faba bean. This interaction between plant composition and predator community composition on the foraging behaviour of sub-dominants is thought to underlie the observed effect of plant composition on the multi-predator effect. Thus, the emergence of multi-predator effects is shown to be strongly influenced by

  15. 78 FR 60254 - Endangered and Threatened Species; Take of Anadromous Fish

    Science.gov (United States)

    2013-10-01

    ... and Threatened Species; Take of Anadromous Fish AGENCY: National Marine Fisheries Service (NMFS... regulations governing listed fish and wildlife permits (50 CFR 222-226). NMFS issues permits based on findings... conduct water quality, [[Page 60255

  16. 78 FR 4836 - Endangered and Threatened Species; Take of Anadromous Fish

    Science.gov (United States)

    2013-01-23

    ... and Threatened Species; Take of Anadromous Fish AGENCY: National Marine Fisheries Service (NMFS... steelhead promulgated under the Endangered Species Act (ESA). The plan specifies fishery management...: January 17, 2013. Angela Somma, Chief, Endangered Species Division, Office of Protected Resources...

  17. 78 FR 4834 - Endangered and Threatened Species; Take of Anadromous Fish

    Science.gov (United States)

    2013-01-23

    ... DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration RIN 0648-XC444 Endangered and Threatened Species; Take of Anadromous Fish AGENCY: National Marine Fisheries Service (NMFS... species. Dated: January 16, 2013. Angela Somma, Chief, Endangered Species Division, Office of Protected...

  18. 77 FR 34349 - Endangered and Threatened Species; Take of Anadromous Fish

    Science.gov (United States)

    2012-06-11

    ... and Threatened Species; Take of Anadromous Fish AGENCY: National Marine Fisheries Service (NMFS... and steelhead under the Endangered Species Act (ESA). The HGMPs specify the operations of four... Somma, Chief, Endangered Species Division, Office of Protected Resources, National Marine Fisheries...

  19. Habitat-specific foraging strategies in Australasian gannets

    Directory of Open Access Journals (Sweden)

    Melanie R. Wells

    2016-07-01

    Full Text Available Knowledge of top predator foraging adaptability is imperative for predicting their biological response to environmental variability. While seabirds have developed highly specialised techniques to locate prey, little is known about intraspecific variation in foraging strategies with many studies deriving information from uniform oceanic environments. Australasian gannets (Morus serrator typically forage in continental shelf regions on small schooling prey. The present study used GPS and video data loggers to compare habitat-specific foraging strategies at two sites of contrasting oceanographic regimes (deep water near the continental shelf edge, n=23; shallow inshore embayment, n=26, in south-eastern Australia. Individuals from the continental shelf site exhibited pelagic foraging behaviours typical of gannet species, using local enhancement to locate and feed on small schooling fish; in contrast only 50% of the individuals from the inshore site foraged offshore, displaying the typical pelagic foraging strategy. The remainder adopted a strategy of searching sand banks in shallow inshore waters in the absence of conspecifics and other predators for large, single prey items. Furthermore, of the individuals foraging inshore, 93% were male, indicating that the inshore strategy may be sex-specific. Large inter-colony differences in Australasian gannets suggest strong plasticity in foraging behaviours, essential for adapting to environmental change.

  20. Endangered fish species of Kenya's inland waters with emphasis on Labeo spp

    OpenAIRE

    Kibaara, D.

    1986-01-01

    The importance of water masses, natural or otherwise, in supporting fisheries, and the importance of fish as human food, cannot be overemphasized. The inland waters of Kenya act as habitats for fish, harbouring many different fish species. It has been observed with interest that certain fish species have decreased in numbers over the years within the inland waters. The decline has been at a rate which, if left unchecked, will eventually cause total di...

  1. Na and K Levels in forage species from the communal grazing lands during the dry season at some locations in the Northern Region of Ghana

    International Nuclear Information System (INIS)

    Gomda, Y.M.; Osae, E.K.; Akaho, E.H.K.; Fianu, F.K.; Karbo, N.

    1999-04-01

    Forage species were taken, during the dry season, from five districts in the Northern Region of Ghana and analysed for Na and K using the Neutron Activation Analysis (NAA) technique. The Na level varied in plants species as well as location. The level ranged between 0.049 g/kg DM and 1.14 g/kg DM. This was found to be inadequate for the animals and require supplementation during the dry season. Potassium level in the forage species was between 7.8 to 91.3g/kg DM and appeared to be adequate for the grazing animals. (author)

  2. Prevalence of listeria, Aeromonas, and Vibrio species in fish used for human consumption in Turkey.

    Science.gov (United States)

    Yücel, Nihal; Balci, Senay

    2010-02-01

    A total of 78 raw retail fish samples from 30 freshwater and 48 marine fish were examined for the presence of Listeria, Aeromonas, and Vibrio species. The overall incidence of Listeria spp. was 30% in freshwater samples and 10.4% in marine fish samples. Listeria monocytogenes (44.5%) was the most commonly isolated species in freshwater fish, and Listeria murrayi (83.5%) was the most commonly isolated species in marine fish samples. Motile aeromonads were more common in marine fish samples (93.7%) than in freshwater fish samples (10%). Vibrio alginolyticus, Vibrio fluvialis, and Vibrio damsela were isolated only in marine fish samples, representing 40.9, 38.6, and 36.3% of Vibrio isolates, respectively. In freshwater and marine fish, the highest incidences of Listeria and Aeromonas were found in skin samples; the highest incidence of Vibrio in marine fish was found in gill samples. The location of Listeria spp. and L. monocytogenes in a fish was significantly different among freshwater fish. A high incidence of these bacterial pathogens was found in the brown trout (Salmo trutta) and horse mackerel (Trachurus trachurus). Handling of contaminated fish, cross-contamination, or eating raw fish might pose a health hazard, especially in immunosuppressed individuals, elderly people, and children. This study highlights the importance of bacterial pathogens in fish intended for human consumption, but more study is needed.

  3. Mercury and persistent organic pollutants in native and invading forage species of the Canadian Arctic: Consequences for food web dynamics.

    Science.gov (United States)

    Pedro, Sara; Fisk, Aaron T; Tomy, Gregg T; Ferguson, Steven H; Hussey, Nigel E; Kessel, Steven T; McKinney, Melissa A

    2017-10-01

    Contaminant dynamics within Arctic marine food webs may be altered through the climate-driven northward invasions of temperate/boreal species. Here, we compare tissue concentrations of total mercury (THg) and legacy and emerging persistent organic pollutants (POPs) in native versus invading forage species sampled from 2012 to 2014 near Arviat, Clyde River, and Resolute Bay, NU, representing, low, mid- and high eastern Canadian Arctic regions, respectively. Concentrations of THg, legacy Σ-polychlorinated biphenyls (ΣPCB) and Σ-organochlorine (ΣOC) pesticides were detected in all forage species, whereas emerging halogenated flame retardants were detected in only a few individuals. Concentrations of major contaminant groups among regions did not vary for Arctic cod (Boreogadus saida), while for sculpin (Cottoidea) there was no clear latitudinal trend. Thus, considering interspecific variation, native sculpin and northern shrimp (Pandalus borealis) had the highest overall concentrations of THg (0.17 ± 0.02 and 0.21 ± 0.01 μg g -1 wet weight, respectively), ΣPCB (322 ± 35 and 245 ± 25 ng g -1 lipid weight (lw), respectively), and ΣOC (413 ± 38 and 734 ± 64 ng g -1 lw, respectively). Comparing the keystone native species, Arctic cod, to its 'replacement' species, capelin (Mallotus villosus) and sandlance (Ammodytes spp.), THg concentrations were higher in Arctic cod compared to capelin (p compound patterns, in capelin and sandlance relative to Arctic cod seem, therefore, more likely related to a more "temperate"-type contaminant signature in the invaders. Nevertheless, the relatively small (up to two-fold) magnitude of these differences suggested limited effects of these ecological changes on contaminant uptake by Arctic piscivores. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. Nutrient and energy content, in vitro ruminal fermentation characteristics and methanogenic potential of alpine forage plant species during early summer.

    Science.gov (United States)

    Jayanegara, Anuraga; Marquardt, Svenja; Kreuzer, Michael; Leiber, Florian

    2011-08-15

    Plants growing on alpine meadows are reported to be rich in phenols. Such compounds may affect ruminal fermentation and reduce the plants' methanogenic potential, making alpine grazing advantageous in this respect. The objective of this study was to quantify nutrients and phenols in Alpine forage grasses, herbs and trees collected over 2 years and, in a 24 h in vitro incubation, their effects on ruminal fermentation parameters. The highest in vitro gas production, resulting in metabolisable energy values around 10 MJ kg⁻¹, were found with Alchemilla xanthochlora and Crepis aurea (herbaceous species) and with Sambucus nigra leaves and flowers (tree species). Related to the amount of total gas production, methane formation was highest with Nardus stricta, and lowest with S. nigra and A. xanthochlora. In addition, Castanea sativa leaves led to an exceptional low methane production, but this was accompanied by severely impaired ruminal fermentation. When the data were analysed by principal component analysis, phenol concentrations were negatively related with methane proportion in total gas. Variation in methane production potential across the investigated forages was small. The two goals of limited methane production potential and high nutritive value for ruminants were met best by A. xanthochlora and S. nigra. Copyright © 2011 Society of Chemical Industry.

  5. Preliminarily study on the maximum handling size, prey size and species selectivity of growth hormone transgenic and non-transgenic common carp Cyprinus carpio when foraging on gastropods

    Science.gov (United States)

    Zhu, Tingbing; Zhang, Lihong; Zhang, Tanglin; Wang, Yaping; Hu, Wei; Olsen, Rolf Eric; Zhu, Zuoyan

    2017-10-01

    The present study preliminarily examined the differences in maximum handling size, prey size and species selectivity of growth hormone transgenic and non-transgenic common carp Cyprinus carpio when foraging on four gastropods species (Bellamya aeruginosa, Radix auricularia, Parafossarulus sinensis and Alocinma longicornis) under laboratory conditions. In the maximum handling size trial, five fish from each age group (1-year-old and 2-year-old) and each genotype (transgenic and non-transgenic) of common carp were individually allowed to feed on B. aeruginosa with wide shell height range. The results showed that maximum handling size increased linearly with fish length, and there was no significant difference in maximum handling size between the two genotypes. In the size selection trial, three pairs of 2-year-old transgenic and non-transgenic carp were individually allowed to feed on three size groups of B. aeruginosa. The results show that the two genotypes of C. carpio favored the small-sized group over the large-sized group. In the species selection trial, three pairs of 2-year-old transgenic and non-transgenic carp were individually allowed to feed on thin-shelled B. aeruginosa and thick-shelled R. auricularia, and five pairs of 2-year-old transgenic and non-transgenic carp were individually allowed to feed on two gastropods species (P. sinensis and A. longicornis) with similar size and shell strength. The results showed that both genotypes preferred thin-shelled Radix auricularia rather than thick-shelled B. aeruginosa, but there were no significant difference in selectivity between the two genotypes when fed on P. sinensis and A. longicornis. The present study indicates that transgenic and non-transgenic C. carpio show similar selectivity of predation on the size- and species-limited gastropods. While this information may be useful for assessing the environmental risk of transgenic carp, it does not necessarily demonstrate that transgenic common carp might

  6. Earning their stripes: The potential of tiger trout and other salmonids as biological controls of forage fishes in a western reservoir

    Science.gov (United States)

    Winters, Lisa K.; Budy, Phaedra; Thiede, Gary P.

    2017-01-01

    Maintaining a balance between predator and prey populations can be an ongoing challenge for fisheries managers, especially in managing artificial ecosystems such as reservoirs. In a high-elevation Utah reservoir, the unintentional introduction of the Utah Chub Gila atraria and its subsequent population expansion prompted managers to experimentally shift from exclusively stocking Rainbow Trout Oncorhynchus mykiss to also stocking tiger trout (female Brown Trout Salmo trutta × male Brook Trout Salvelinus fontinalis) and Bonneville Cutthroat Trout O. clarkii utah (hereafter, Cutthroat Trout) as potential biological control agents. We measured a combination of diet, growth, temperature, and abundance and used bioenergetic simulations to quantify predator demand versus prey supply. Utah Chub were the predominant prey type for tiger trout, contributing up to 80% of the diet depending on the season. Utah Chub represented up to 70% of the total diet consumed by Cutthroat Trout. Although Utah Chub dominated the fish biomass in the reservoir, we still estimated abundances of 238,000 tiger trout, 214,000 Cutthroat Trout, and 55,000 Rainbow Trout. Consequently, when expanded to the population level of each predator, tiger trout and Cutthroat Trout consumed large quantities of Utah Chub on an annual basis: tiger trout consumed 508,000 kg (2,660 g/predator) of the standing prey population, and Cutthroat Trout consumed an estimated 322,000 kg (1,820 g/predator). The estimated combined consumption by Cutthroat Trout and tiger trout exceeded the estimate of Utah Chub annual production. As such, our results suggest that the high rates of piscivory exhibited by Cutthroat Trout and tiger trout in artificial lentic ecosystems are likely sufficient to effectively reduce the overall abundance of forage fishes and to prevent forage fishes from dominating fish assemblages. Collectively, this research provides the first documented findings on tiger trout ecology and performance

  7. 75 FR 16738 - Endangered and Threatened Species; Take of Anadromous Fish

    Science.gov (United States)

    2010-04-02

    ... and Threatened Species; Take of Anadromous Fish AGENCY: National Marine Fisheries Service (NMFS... River fall Chinook salmon under the Endangered Species Act (ESA). The FMEP specifies the future... fish, sturgeon, carp, and other species.'' The FMEP describes the management of recreational fisheries...

  8. 75 FR 14134 - Endangered and Threatened Species; Take of Anadromous Fish

    Science.gov (United States)

    2010-03-24

    ... and Threatened Species; Take of Anadromous Fish AGENCY: National Marine Fisheries Service (NMFS... modifications, as required by the Endangered Species Act of 1973 (16 U.S.C. 1531 1543) (ESA), is based on a... trap and beach seine, anesthesize and sample fish for species identification, tags, marks and fin clips...

  9. 77 FR 27186 - Endangered and Threatened Species; Take of Anadromous Fish

    Science.gov (United States)

    2012-05-09

    ... and Threatened Species; Take of Anadromous Fish AGENCY: National Marine Fisheries Service (NMFS... Endangered Species Act (ESA) and to help guide management and conservation efforts. The applications may be... salmon, and LCR steelhead. The purpose of this research is to determine fish species presence and...

  10. 76 FR 51352 - Endangered and Threatened Species; Take of Anadromous Fish

    Science.gov (United States)

    2011-08-18

    ... Department of Fish and Wildlife (WDFW), for a direct take permit pursuant to the Endangered Species Act of... and Threatened Species; Take of Anadromous Fish AGENCY: National Marine Fisheries Service (NMFS... Section 9 of the ESA and Federal regulations prohibit the ``taking'' of a species listed as endangered or...

  11. 76 FR 57717 - Endangered and Threatened Species; Take of Anadromous Fish

    Science.gov (United States)

    2011-09-16

    ... and Threatened Species; Take of Anadromous Fish AGENCY: National Marine Fisheries Service (NMFS..., importing, and exporting of endangered and threatened species (50 CFR parts 222-226). Permits Permit 15926... will be captured by fyke net, identified to species, enumerated and measured. Dead or moribund fish...

  12. 75 FR 78226 - Endangered and Threatened Species; Take of Anadromous Fish

    Science.gov (United States)

    2010-12-15

    ... and Threatened Species; Take of Anadromous Fish AGENCY: National Marine Fisheries Service (NMFS... permits and permit modifications, as required by the Endangered Species Act of 1973 (16 U.S.C. 1531-1543... electrofisher and dipnet; sample fish for species identification, tags, marks and finclips, lengths and weights...

  13. Analysis of endangered Kansas fish species distribution during historical and contemporary periods (pre- and post-1969)

    Science.gov (United States)

    Background/Question/Methods Kansas has more freshwater fish species than other states in the west and northern US. More than 140 fishes have recently been documented in Kansas rivers; of these, at least five are categorized as endangered species in Kansas (and threatened species ...

  14. 77 FR 51763 - Endangered and Threatened Species; Take of Anadromous Fish

    Science.gov (United States)

    2012-08-27

    ... and Threatened Species; Take of Anadromous Fish AGENCY: National Marine Fisheries Service (NMFS... INFORMATION: Authority The issuance of permits and permit modifications, as required by the Endangered Species... (50 CFR parts 222-226) governing listed fish and wildlife permits. Species Covered in This Notice This...

  15. 75 FR 33243 - Endangered and Threatened Species; Take of Anadromous Fish

    Science.gov (United States)

    2010-06-11

    ... and Threatened Species; Take of Anadromous Fish AGENCY: NOAA's National Marine Fisheries Service (NMFS... Endangered Species Act of 1973 (16 U.S.C. 1531-1543) (ESA), is based on a finding that such permits... NMFS regulations (50 CFR parts 222-226) governing listed fish and wildlife permits. Species Covered in...

  16. 75 FR 23671 - Endangered and Threatened Species; Take of Anadromous Fish; Research Permit Applications

    Science.gov (United States)

    2010-05-04

    ... and Threatened Species; Take of Anadromous Fish; Research Permit Applications AGENCY: National Marine... listed under the Endangered Species Act (ESA) and to help guide management and conservation efforts. The... capture, handle, and release juvenile fish from all the species covered by this notice. They would also...

  17. 76 FR 15946 - Endangered and Threatened Species; Take of Anadromous Fish

    Science.gov (United States)

    2011-03-22

    ... and Threatened Species; Take of Anadromous Fish AGENCY: National Marine Fisheries Service (NMFS... research permit application request relating to salmonids listed under the Endangered Species Act (ESA... research activities. The purpose of the research program is to collect warmwater fish species to analyze...

  18. Foraging Activity of Four Bee Species on Sesame Flowers During Two Successive Seasons in Ismailia Governorate, Egypt

    Directory of Open Access Journals (Sweden)

    Soliman M. Kamel

    2013-01-01

    Full Text Available Foraging activity of four bee species, Apis mellifera L., Osmia spp., Ceratina tarsataMorawitz and Xylocopa pubescens Spinola on sesame flowers was studied during two successiveseasons of 2011 and 2012. Experimental observations were made during four periodsof the day: 9:00-11:00 am, 11:00 am-1:00 pm, 1:00-3:00 pm and 3:00-5:00 pm, startingfrom initial flowering until the final session. Observation time was five minutes during eachperiod and four bee species were observed visiting each square meter area. Five spots of 1m2 area were selected randomly, and the number of different species of bees visiting wascounted for five minutes by using electronic stopwatch, voice recorder and digital videocamera. The results of the study indicated that the four bee species were most abundanton sesame flowers between 11:00 am and 1:00 pm, and between 1:00 and 3:00 pm. Amongthe bees, Apis mellifera was the predominant species, followed by Ceratina tarsata, in theseason of 2011, while a reverse order of the two was recorded in 2012. The average timespent per flower was highly significantly different among these four species.

  19. The Foraging Ecology of the Endangered Cape Verde Shearwater, a Sentinel Species for Marine Conservation off West Africa.

    Science.gov (United States)

    Paiva, Vitor H; Geraldes, Pedro; Rodrigues, Isabel; Melo, Tommy; Melo, José; Ramos, Jaime A

    2015-01-01

    Large Marine Ecosystems such as the Canary Current system off West Africa sustains high abundance of small pelagic prey, which attracts marine predators. Seabirds are top predators often used as biodiversity surrogates and sentinel species of the marine ecosystem health, thus frequently informing marine conservation planning. This study presents the first data on the spatial (GPS-loggers) and trophic (stable isotope analysis) ecology of a tropical seabird-the endangered Cape Verde shearwater Calonectris edwardsii-during both the incubation and the chick-rearing periods of two consecutive years. This information was related with marine environmental predictors (species distribution models), existent areas of conservation concern for seabirds (i.e. marine Important Bird Areas; marine IBAs) and threats to the marine environment in the West African areas heavily used by the shearwaters. There was an apparent inter-annual consistency on the spatial, foraging and trophic ecology of Cape Verde shearwater, but a strong alteration on the foraging strategies of adult breeders among breeding phases (i.e. from incubation to chick-rearing). During incubation, birds mostly targeted a discrete region off West Africa, known by its enhanced productivity profile and thus also highly exploited by international industrial fishery fleets. When chick-rearing, adults exploited the comparatively less productive tropical environment within the islands of Cape Verde, at relatively close distance from their breeding colony. The species enlarged its trophic niche and increased the trophic level of their prey from incubation to chick-rearing, likely to provision their chicks with a more diversified and better quality diet. There was a high overlap between the Cape Verde shearwaters foraging areas with those of European shearwater species that overwinter in this area and known areas of megafauna bycatch off West Africa, but very little overlap with existing Marine Important Bird Areas. Further

  20. The Foraging Ecology of the Endangered Cape Verde Shearwater, a Sentinel Species for Marine Conservation off West Africa.

    Directory of Open Access Journals (Sweden)

    Vitor H Paiva

    Full Text Available Large Marine Ecosystems such as the Canary Current system off West Africa sustains high abundance of small pelagic prey, which attracts marine predators. Seabirds are top predators often used as biodiversity surrogates and sentinel species of the marine ecosystem health, thus frequently informing marine conservation planning. This study presents the first data on the spatial (GPS-loggers and trophic (stable isotope analysis ecology of a tropical seabird-the endangered Cape Verde shearwater Calonectris edwardsii-during both the incubation and the chick-rearing periods of two consecutive years. This information was related with marine environmental predictors (species distribution models, existent areas of conservation concern for seabirds (i.e. marine Important Bird Areas; marine IBAs and threats to the marine environment in the West African areas heavily used by the shearwaters. There was an apparent inter-annual consistency on the spatial, foraging and trophic ecology of Cape Verde shearwater, but a strong alteration on the foraging strategies of adult breeders among breeding phases (i.e. from incubation to chick-rearing. During incubation, birds mostly targeted a discrete region off West Africa, known by its enhanced productivity profile and thus also highly exploited by international industrial fishery fleets. When chick-rearing, adults exploited the comparatively less productive tropical environment within the islands of Cape Verde, at relatively close distance from their breeding colony. The species enlarged its trophic niche and increased the trophic level of their prey from incubation to chick-rearing, likely to provision their chicks with a more diversified and better quality diet. There was a high overlap between the Cape Verde shearwaters foraging areas with those of European shearwater species that overwinter in this area and known areas of megafauna bycatch off West Africa, but very little overlap with existing Marine Important Bird

  1. Chemical composition, mineral content and amino acid and lipid profiles in bones from various fish species.

    Science.gov (United States)

    Toppe, Jogeir; Albrektsen, Sissel; Hope, Britt; Aksnes, Anders

    2007-03-01

    The chemical composition, content of minerals and the profiles of amino acids and fatty acids were analyzed in fish bones from eight different species of fish. Fish bones varied significantly in chemical composition. The main difference was lipid content ranging from 23 g/kg in cod (Gadus morhua) to 509 g/kg in mackerel (Scomber scombrus). In general fatty fish species showed higher lipid levels in the bones compared to lean fish species. Similarly, lower levels of protein and ash were observed in bones from fatty fish species. Protein levels differed from 363 g/kg lipid free dry matter (dm) to 568 g/kg lipid free dm with a concomitant inverse difference in ash content. Ash to protein ratio differed from 0.78 to 1.71 with the lowest level in fish that naturally have highest swimming and physical activity. Saithe (Pollachius virens) and salmon (Salmo salar) were found to be significantly different in the levels of lipid, protein and ash, and ash/protein ratio in the bones. Only small differences were observed in the level of amino acids although species specific differences were observed. The levels of Ca and P in lipid free fish bones were about the same in all species analyzed. Fatty acid profile differed in relation to total lipid levels in the fish bones, but some minor differences between fish species were observed.

  2. Fish allergy in patients with parvalbumin-specific immunoglobulin E depends on parvalbumin content rather than molecular differences in the protein among fish species.

    Science.gov (United States)

    Kobayashi, Ayako; Kobayashi, Yukihiro; Shiomi, Kazuo

    2016-10-01

    Allergenic characteristics of purified parvalbumins from different fish species have not been thoroughly investigated. We revealed that purified parvalbumins from nine different fish species have identical IgE-reactivities and high cross-reactivities. We also showed that fish allergenicity is associated with the parvalbumin content of the fish species, rather than species-specific differences in the molecular characteristics of the individual parvalbumin proteins.

  3. Current status of non-native fish species in the St. Louis River estuary

    Science.gov (United States)

    The fish community of the St. Louis River estuary is well characterized, thanks to fishery assessment and invasive species early detection monitoring by federal, state, and tribal agencies. This sampling includes long-standing adult/juvenile fish surveys, larval fish surveys beg...

  4. 77 FR 69593 - Atlantic Highly Migratory Species; Exempted Fishing, Scientific Research, Display, and Chartering...

    Science.gov (United States)

    2012-11-20

    ... Highly Migratory Species; Exempted Fishing, Scientific Research, Display, and Chartering Permits; Letters... intent to issue Exempted Fishing Permits (EFPs), Scientific Research Permits (SRPs), Display Permits... public display and scientific research that is exempt from regulations (e.g., fishing seasons, prohibited...

  5. 78 FR 43858 - Endangered and Threatened Species; Take of Anadromous Fish

    Science.gov (United States)

    2013-07-22

    ... and Threatened Species; Take of Anadromous Fish AGENCY: National Marine Fisheries Service (NMFS... number of predicted adults increase, the number of fish escaping to the spawning grounds will also... fish; and (3) application of a sliding scale approach to determine appropriate ESA take limits on...

  6. 76 FR 2664 - Endangered and Threatened Species; Take of Anadromous Fish

    Science.gov (United States)

    2011-01-14

    ... and Threatened Species; Take of Anadromous Fish AGENCY: National Marine Fisheries Service (NMFS...) and 14092 (applicant: California Department of Fish and Game). In that notice, the permit application... American green sturgeon associated with conducting surveys measuring fish response to initial and...

  7. 78 FR 28805 - Endangered and Threatened Species; Take of Anadromous Fish

    Science.gov (United States)

    2013-05-16

    ... and Threatened Species; Take of Anadromous Fish AGENCY: National Marine Fisheries Service (NMFS..., NMFS received an application, including an HGMP, from the Idaho Department of Fish and Game, a section... the Snake River basin, rear juveniles, and release eggs, juveniles, and adult fish into upper Salmon...

  8. 78 FR 79674 - Endangered and Threatened Species; Take of Anadromous Fish

    Science.gov (United States)

    2013-12-31

    ... and Threatened Species; Take of Anadromous Fish AGENCY: National Marine Fisheries Service (NMFS... the ESA (16 U.S.C. 1531 et seq.) and regulations governing listed fish and wildlife permits (50 CFR.... Fish and Wildlife Service (USFWS) submitted an application and supporting documents to NMFS for a...

  9. 78 FR 31518 - Endangered and Threatened Species; Take of Anadromous Fish

    Science.gov (United States)

    2013-05-24

    ... DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration RIN 0648-XC690 Endangered and Threatened Species; Take of Anadromous Fish AGENCY: National Marine Fisheries Service (NMFS... Department of Fish and Wildlife (ODFW), Washington Department of Fish and Wildlife (WDFW), and U.S. Bureau of...

  10. 78 FR 32378 - Endangered and Threatened Species; Take of Anadromous Fish

    Science.gov (United States)

    2013-05-30

    ... and Threatened Species; Take of Anadromous Fish AGENCY: National Marine Fisheries Service (NMFS... application was provided by the Washington Department of Fish and Wildlife (WDFW) and the Public Utility... Department of Fish and Wildlife submitted an application for an ESA permit to operate the Nason Creek spring...

  11. 77 FR 3743 - Endangered and Threatened Species; Take of Anadromous Fish

    Science.gov (United States)

    2012-01-25

    ... and Threatened Species; Take of Anadromous Fish AGENCY: National Marine Fisheries Service (NMFS... with section 10(a)(1)(A) of the ESA of 1973 (16 U.S.C. 1531-1543) and regulations governing listed fish... listed fish but a small number may die as an unintended result of the research activities. The objectives...

  12. 76 FR 8713 - Endangered and Threatened Species; Take of Anadromous Fish

    Science.gov (United States)

    2011-02-15

    ... and Threatened Species; Take of Anadromous Fish AGENCY: National Marine Fisheries Service (NMFS... (16 U.S.C. 1531-1543) and regulations governing listed fish and wildlife permits (50 CFR parts 222-226... handling of fish is already covered under the Incidental Take Statement associated with the Biological...

  13. 78 FR 7755 - Endangered and Threatened Species; Take of Anadromous Fish

    Science.gov (United States)

    2013-02-04

    ... and Threatened Species; Take of Anadromous Fish AGENCY: National Marine Fisheries Service (NMFS...)(A) of the ESA of 1973 (16 U.S.C. 1531-1543) and regulations governing listed fish and wildlife.... In situations where the SWFSC are unable to rely on collaborators to capture fish through rotary...

  14. 78 FR 52487 - Atlantic Highly Migratory Species; 2014 Atlantic Shark Commercial Fishing Season

    Science.gov (United States)

    2013-08-23

    .... 130402317-3707-01] RIN 0648-XC611 Atlantic Highly Migratory Species; 2014 Atlantic Shark Commercial Fishing... establish opening dates and adjust quotas for the 2014 fishing season for the Atlantic commercial shark... management measures to provide, to the extent practicable, fishing opportunities for commercial shark...

  15. 77 FR 61562 - Atlantic Highly Migratory Species; 2013 Atlantic Shark Commercial Fishing Season

    Science.gov (United States)

    2012-10-10

    .... 120706221-2481-01] RIN 0648-XC106 Atlantic Highly Migratory Species; 2013 Atlantic Shark Commercial Fishing... establish opening dates and adjust quotas for the 2013 fishing season for the Atlantic commercial shark... the 2011 and 2012 Atlantic commercial shark fishing seasons. We propose to keep the porbeagle shark...

  16. 76 FR 67121 - Atlantic Highly Migratory Species; 2012 Atlantic Shark Commercial Fishing Season

    Science.gov (United States)

    2011-10-31

    .... 110913585-1625-01] RIN 0648-BB36 Atlantic Highly Migratory Species; 2012 Atlantic Shark Commercial Fishing... establish opening dates and adjust quotas for the 2012 fishing season for the Atlantic commercial shark... 2011 Atlantic commercial shark fishing seasons. In addition, NMFS proposes season openings based on...

  17. Length-weight relationships for 13 fish species from the Gulf of ...

    African Journals Online (AJOL)

    Length-weight relationships (LWR) were estimated for 13 fish species which are of economic relevance in the commercial fisheries of the Gulf of Gabes (southern Tunisia). A total of 2403 fish specimens were sampled with several fishing gears from October 2008 to September 2009. The sample size ranged from 65 ...

  18. 78 FR 17355 - Endangered and Threatened Species; Take of Anadromous Fish

    Science.gov (United States)

    2013-03-21

    ... and Threatened Species; Take of Anadromous Fish AGENCY: National Marine Fisheries Service (NMFS... 10(a)(1)(A) of the ESA of 1973 (16 U.S.C. 1531-1543) and regulations governing listed fish and... expect to kill any listed fish but a small number may die as an unintended result of the research...

  19. 77 FR 63294 - Endangered and Threatened Species; Take of Anadromous Fish

    Science.gov (United States)

    2012-10-16

    ... and Threatened Species; Take of Anadromous Fish AGENCY: National Marine Fisheries Service (NMFS... Klallam Tribe and the Washington Department of Fish and Wildlife have submitted five Hatchery and Genetic... programs are currently operating, and all five hatchery programs raise fish native to the Elwha River basin...

  20. 78 FR 25954 - Endangered and Threatened Species; Take of Anadromous Fish

    Science.gov (United States)

    2013-05-03

    ... and Threatened Species; Take of Anadromous Fish AGENCY: National Marine Fisheries Service (NMFS... 15, 2012, NMFS received an application, including an HGMP, from the Idaho Department of Fish and Game... salmon returning to the Snake River basin, rear juveniles, and release eggs, juveniles, and adult fish...

  1. 78 FR 18963 - Endangered and Threatened Species; Take of Anadromous Fish

    Science.gov (United States)

    2013-03-28

    ... and Threatened Species; Take of Anadromous Fish AGENCY: National Marine Fisheries Service (NMFS... governing listed fish and wildlife permits (50 CFR parts 222-226). NMFS issues permits based on findings... Administrator for Fisheries, NMFS. Applications Received Permit 17551 The California Department of Fish and...

  2. 77 FR 42278 - Endangered and Threatened Species; Take of Anadromous Fish

    Science.gov (United States)

    2012-07-18

    ... and Threatened Species; Take of Anadromous Fish AGENCY: National Marine Fisheries Service (NMFS... regulations governing listed fish and wildlife permits (50 CFR parts 222-226). NMFS issues permits based on.... This project will examine predation by introduced fishes (striped bass, largemouth bass, smallmouth...

  3. 77 FR 76001 - Endangered and Threatened Species; Take of Anadromous Fish

    Science.gov (United States)

    2012-12-26

    ... and Threatened Species; Take of Anadromous Fish AGENCY: National Marine Fisheries Service (NMFS... regulations governing listed fish and wildlife permits(50 CFR parts 222-226). NMFS issues permits based on... described below, researchers do not expect to kill any listed fish but a small number may die as an...

  4. Functional feeding traits as predictors of invasive success of alien freshwater fish species using a food-fish model.

    Directory of Open Access Journals (Sweden)

    Leopold A J Nagelkerke

    Full Text Available Invasions of Ponto-Caspian fish species into north-western European river basins accelerated since the opening of the Rhine-Main-Danube Canal in 1992. Since 2002, at least five Ponto-Caspian alien fish species have arrived in The Netherlands. Four species belong to the Gobiidae family (Neogobius fluviatilis, Neogobius melanostomus, Ponticola kessleri, and Proterorhinus semilunaris and one to the Cyprinidae family (Romanogobio belingi. These species are expected to be potentially deleterious for the populations of four native benthic fish species: Gobio gobio (Cyprinidae, Barbatula barbatula (Nemacheilidae, Cottus perifretum, and C. rhenanus (Cottidae. Invasion success may be dependent on competitive trophic interactions with native species, which are enabled and/or constrained by feeding-related morphological traits. Twenty-two functional feeding traits were measured in nine species (in total 90 specimens. These traits were quantitatively linked to the mechanical, chemical and behavioral properties of a range of aquatic resource categories, using a previously developed food-fish model (FFM. The FFM was used to predict the trophic profile (TP of each fish: the combined capacities to feed on each of the resource types. The most extreme TPs belonged to three alien species, indicating that they were most specialized among the studied species. Of these three, only P. kessleri overlapped with the two native Cottus species, indicating potential trophic competition. N. fluviatilis and R. belingi did not show any overlap, indicating that there is low trophic competition. The two remaining alien goby species (N. melanostomus and P. semilunaris had average TPs and could be considered generalist feeders. They overlapped with each other and with G. gobio and B. barbatula, indicating potential trophic competition. This study suggests that both generalist and specialist species can be successful invaders. Since the FFM predicts potential interactions between

  5. Functional feeding traits as predictors of invasive success of alien freshwater fish species using a food-fish model.

    Science.gov (United States)

    Nagelkerke, Leopold A J; van Onselen, Eline; van Kessel, Nils; Leuven, Rob S E W

    2018-01-01

    Invasions of Ponto-Caspian fish species into north-western European river basins accelerated since the opening of the Rhine-Main-Danube Canal in 1992. Since 2002, at least five Ponto-Caspian alien fish species have arrived in The Netherlands. Four species belong to the Gobiidae family (Neogobius fluviatilis, Neogobius melanostomus, Ponticola kessleri, and Proterorhinus semilunaris) and one to the Cyprinidae family (Romanogobio belingi). These species are expected to be potentially deleterious for the populations of four native benthic fish species: Gobio gobio (Cyprinidae), Barbatula barbatula (Nemacheilidae), Cottus perifretum, and C. rhenanus (Cottidae). Invasion success may be dependent on competitive trophic interactions with native species, which are enabled and/or constrained by feeding-related morphological traits. Twenty-two functional feeding traits were measured in nine species (in total 90 specimens). These traits were quantitatively linked to the mechanical, chemical and behavioral properties of a range of aquatic resource categories, using a previously developed food-fish model (FFM). The FFM was used to predict the trophic profile (TP) of each fish: the combined capacities to feed on each of the resource types. The most extreme TPs belonged to three alien species, indicating that they were most specialized among the studied species. Of these three, only P. kessleri overlapped with the two native Cottus species, indicating potential trophic competition. N. fluviatilis and R. belingi did not show any overlap, indicating that there is low trophic competition. The two remaining alien goby species (N. melanostomus and P. semilunaris) had average TPs and could be considered generalist feeders. They overlapped with each other and with G. gobio and B. barbatula, indicating potential trophic competition. This study suggests that both generalist and specialist species can be successful invaders. Since the FFM predicts potential interactions between species, it

  6. [Species composition and geographical distribution of threatened fishes in Yunnan Province of Southwest China].

    Science.gov (United States)

    Zhang, Qian; Zhong, Jin-Xin

    2013-05-01

    Based on the related published papers, and by using Geographic Information System (ArcGIS 9.3), this paper analyzed the species composition and geographical distribution of threatened fishes in Yunnan Province of Southwest China. There were 83 threatened species living in the Province, belonging to 5 orders, 13 families, and 47 genera. Cypriniformes was absolutely dominant, with 64 species, followed by Siluriformes, with 16 species. Cyprinidae fishes had 51 species, accounting for 79.7% of Cypriniformes. The most species of Cyprinid fishes were of Barbinae (14 species), Cyprininae (10 species), and Cultrinae (10 species). The threatened fishes could be divided into two zoogeographical regions, i. e., Tibetan Plateau region and Oriental region, and their species composition and geographical distribution were resulted from the historical evolution adapted to the related environments. Whatever in rivers and in lakes, the Cyprinid fishes were both absolutely dominant, occupying 36.1% and 31.3% of the total, respectively. The Cyprinid fishes in rivers were mostly of endangered species, while those in lakes were mostly of vulnerable species. The factors affecting the threatened fishes in the Province were discussed from the two aspects of geodynamic evolution and present situation.

  7. Advanced phenotyping offers opportunities for improved breeding of forage and turf species

    DEFF Research Database (Denmark)

    Walter, Achim; Studer, Bruno; Kölliker, Roland

    2012-01-01

    Background and Aims Advanced phenotyping, i.e. the application of automated, high-throughput methods to characterize plant architecture and performance, has the potential to accelerate breeding progress but is far from being routinely used in current breeding approaches. In forage and turf...... improvement programmes, in particular, where breeding populations and cultivars are characterized by high genetic diversity and substantial genotype × environment interactions, precise and efficient phenotyping is essential to meet future challenges imposed by climate change, growing demand and declining...... resources. Scope This review highlights recent achievements in the establishment of phenotyping tools and platforms. Some of these tools have originally been established in remote sensing, some in precision agriculture, while others are laboratory-based imaging procedures. They quantify plant colour...

  8. Associations of Pseudomonas species and forage grasses enhance degradation of chlorinated benzoic acids in soil

    Energy Technology Data Exchange (ETDEWEB)

    Siciliano, S. D.

    1998-12-01

    Using chlorinated benzoic acid (CBA) as a model compound, this study attempted to show that microorganisms and plants can be used as bioremediation agents to clean up contaminated soil sites in a cost effective and environmentally friendly manner. CBA was used because it is present in soils contaminated with polychlorinated biphenyls (PCBs), or chlorinated pesticides. Sixteen forage grasses were screened in combination with 12 bacterial inoculants for their ability to promote the degradation of CBA in soil. Five associations of plants and bacteria were found to degrade CBA to a greater extent than plants without bacterial inoculants. Bacterial inoculants were shown to stimulate CBA degradation by altering the microbial community present on the root surface and thereby increasing the ability of this community to degrade CBA.

  9. Changes in understory species occurrence of a secondary broadleaved forest after mass mortality of oak trees under deer foraging pressure

    Directory of Open Access Journals (Sweden)

    Hiroki Itô

    2016-12-01

    Full Text Available The epidemic of mass mortality of oak trees by Japanese oak wilt has affected secondary deciduous broadleaved forests that have been used as coppices in Japan. The dieback of oak trees formed gaps in the crown that would be expected to enhance the regeneration of shade-intolerant pioneer species. However, foraging by sika deer Cervus nippon has also affected forest vegetation, and the compound effects of both on forest regeneration should be considered when they simultaneously occur. A field study was conducted in Kyôto City, Japan to investigate how these compound effects affected the vegetation of the understory layer of these forests. The presence/absence of seedlings and saplings was observed for 200 quadrats sized 5 m ×5 m for each species in 1992, before the mass mortality and deer encroachment, and in 2014 after these effects. A hierarchical Bayesian model was constructed to explain the occurrence, survival, and colonization of each species with their responses to the gaps that were created, expanded, or affected by the mass mortality of Quercus serrata trees. The species that occurred most frequently in 1992, Eurya japonica, Quercus glauca, and Cleyera japonica, also had the highest survival probabilities. Deer-unpalatable species such as Symplocos prunifolia and Triadica sebifera had higher colonization rates in the gaps, while the deer-palatable species Aucuba japonica had the smallest survival probability. The gaps thus promoted the colonization of deer-unpalatable plant species such as Symplocos prunifolia and Triadica sebifera. In the future, such deer-unpalatable species may dominate gaps that were created, expanded, or affected by the mass mortality of oak trees.

  10. The effects of turbidity and an invasive species on foraging success of rosyside dace (Clinostomus funduloides)

    Science.gov (United States)

    Peter D. Hazelton; Gary D. Grossman

    2009-01-01

    Habitat degradation and biological invasions are important threats to fish diversity worldwide. We experimentally examined the effects of turbidity, velocity and intra- and interspecific competition on prey capture location, reactive distance and prey capture success of native rosyside dace (Clinostomus funduloides) and invasive yellowfin shiners (Notropis lutipinnis)...

  11. Evaluation of multiwalled carbon nanotubes toxicity in two fish species.

    Science.gov (United States)

    Cimbaluk, Giovani Valentin; Ramsdorf, Wanessa Algarte; Perussolo, Maiara Carolina; Santos, Hayanna Karla Felipe; Da Silva De Assis, Helena Cristina; Schnitzler, Mariane Cristina; Schnitzler, Danielle Caroline; Carneiro, Pedro Gontijo; Cestari, Marta Margarete

    2018-04-15

    Carbon Nanotubes are among the most promising materials for the technology industry. Their unique physical and chemical proprieties may reduce the production costs and improve the efficiency of a large range of products. However, the same characteristics that have made nanomaterials interesting for industry may be responsible for inducing toxic effects on the aquatic organisms. Since the carbon nanotubes toxicity is still a controversial issue, we performed tests of acute and subchronic exposure to a commercial sample of multiwalled carbon nanotubes in two fish species, an exotic model (Danio rerio) and a native one (Astyanax altiparanae). Using the alkaline version of the comet assay on erythrocytes and the piscine micronucleous, also performed on erythrocytes, it was verified that the tested carbon nanotubes sample did not generate apparent genotoxicity by means of single/double DNA strand break or clastogenic/aneugenic effects over any of the species, independently of the exposure period. Although, our findings indicate the possibility of the occurrence of CNTs-DNA crosslinks. Apparently, the sample tested induces oxidative stress after subchronic exposure as shown by activity of superoxide dismutase and catalase. The data obtained by the activity levels of acetylcholinesterase suggests acute neurotoxicity in Astyanax altiparanae and subchronic neurotoxicity in Danio rerio. Copyright © 2017 Elsevier Inc. All rights reserved.

  12. Species List of Alaskan Birds, Mammals, Fish, Amphibians, Reptiles, and Invertebrates. Alaska Region Report Number 82.

    Science.gov (United States)

    Taylor, Tamra Faris

    This publication contains a detailed list of the birds, mammals, fish, amphibians, reptiles, and invertebrates found in Alaska. Part I lists the species by geographical regions. Part II lists the species by the ecological regions of the state. (CO)

  13. 77 FR 31835 - Endangered and Threatened Species; Take of Anadromous Fish

    Science.gov (United States)

    2012-05-30

    ... DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration RIN 0648-XC049 Endangered and Threatened Species; Take of Anadromous Fish AGENCY: National Marine Fisheries Service (NMFS..., 2012. Angela Somma, Chief, Endangered Species Division, Office of Protected Resources, National Marine...

  14. 76 FR 49735 - Endangered and Threatened Species; Take of Anadromous Fish

    Science.gov (United States)

    2011-08-11

    ... DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration RIN 0648-XA631 Endangered and Threatened Species; Take of Anadromous Fish AGENCY: National Marine Fisheries Service (NMFS.... Therese Conant, Acting Chief, Endangered Species Division, Office of Protected Resources, National Marine...

  15. An indicator for ecosystem externalities in fishing

    DEFF Research Database (Denmark)

    Ravn-Jonsen, Lars; Andersen, Ken Haste; Vestergaard, Niels

    2016-01-01

    Ecosystem externalities arise when one use of an ecosystem affects its other uses through the production functions of the ecosystem. We use simulations with a size-spectrum ecosystem model to investigate the ecosystem externality created by fishing of multiple species. The model is based upon...... general ecological principles and is calibrated to the North Sea. Two fleets are considered: a "forage fish" fleet targeting species that mature at small sizes and a "large fish" fleet targeting large piscivorous species. Based on the marginal analysis of the present value of the rent, we develop...... a benefit indicator that explicitly divides the consequences of fishing into internal and external benefits. This analysis demonstrates that the forage fish fleet has a notable economic impact on the large fish fleet, but the reverse is not true. The impact can be either negative or positive, which entails...

  16. The Effect of Water Temperature on Argulus foliaceus L. 1758 (Crustacea; Branchiura on Different Fish Species

    Directory of Open Access Journals (Sweden)

    Mustafa KOYUN

    2011-05-01

    Full Text Available Parasites belonging to Argulus genus, known as fish louse (Argulus foliaceus L. significantly affect in negative way both in natural and farming environment. In this study, the pathogenic effect of fish louse temperature on fish depending on water was investigated. In this research to estimate the effects of several factors such as water temperature, gender of the fish and the infection of fish louse were studied through Poisson regression method. As fish species, Alburnus alburnus (bleak, Carassius carassius (crucian carp and Carassius auratus (golden carp were caught periodically, starting from May during the year, and the parasites were counted. The gender and metrical measures of the examined fish were categorized separately. The degrees of water temperature of the dam were measured. Results from Poisson regression analysis showed that fish louse has harmful effect on the mentioned fish, depending on the water temperature.

  17. Quantification of major allergen parvalbumin in 22 species of fish by SDS-PAGE.

    Science.gov (United States)

    Kobayashi, Yukihiro; Yang, Tao; Yu, Cheng-Tao; Ume, Chiaki; Kubota, Hiroyuki; Shimakura, Kuniyoshi; Shiomi, Kazuo; Hamada-Sato, Naoko

    2016-03-01

    Fish is an important causative material of food allergy. Although the allergenicity of fish is considered to correlate with the content of parvalbumin, the major fish allergen, available information about the parvalbumin content in fish is limited. In this study, a simple and reliable quantification method for fish parvalbumin by SDS-PAGE was first established. Application of the SDS-PAGE method to 22 species of fish revealed a marked variation in parvalbumin content among fish. Furthermore, the parvalbumin content was found to be higher in dorsal white muscle than in ventral white muscle, in rostral part of white muscle than in caudal part of white muscle and in white muscle than in dark muscle. IgE reactivity of fish was roughly proportional to parvalbumin content. Interestingly, large-sized migratory fish, such as salmon, swordfish and tuna, were commonly very low in both parvalbumin content and IgE reactivity. Copyright © 2015 Elsevier Ltd. All rights reserved.

  18. Foraging Activity in Plebeia remota, a Stingless Bees Species, Is Influenced by the Reproductive State of a Colony

    Directory of Open Access Journals (Sweden)

    Patrícia Nunes-Silva

    2010-01-01

    Full Text Available Colonies of the Brazilian stingless bee Plebeia remota show a reproductive diapause in autumn and winter. Therefore, they present two distinct reproductive states, during which colony needs are putatively different. Consequently, foraging should be adapted to the different needs. We recorded the foraging activity of two colonies for 30 days in both phases. Indeed, it presented different patterns during the two phases. In the reproductive diapause, the resource predominantly collected by the foragers was nectar. The majority of the bees were nectar foragers, and the peak of collecting activity occurred around noon. Instead, in the reproductive phase, the predominantly collected resource was pollen, and the peak of activity occurred around 10:00 am. Although the majority of the foragers were not specialized in this phase, there were a larger number of pollen foragers compared to the phase of reproductive diapause. The temperature and relative humidity also influenced the foraging activity.

  19. Indigenous fish species in the modern ichthyofauna of the Balkhash basin

    Directory of Open Access Journals (Sweden)

    Nadir Shamilevich Mamilov

    2015-11-01

    Full Text Available Indigenous fish fauna of the Balkhash basin was mostly formed in the postglacial period and consists of 10 species from Cyprinidae family, 5 from Balitoridae, and 1 from Percidae. More than 20 alien fish species were introduced here during XXth century that led to eradication of indigenous fishes from the Balkhash Lake and the Ili River. Our investigations of the fish fauna during last 25 years revealed permanent shortage of living area of indigenous fishes. Nowadays fish communities from only indigenous fish species exist in some remote and isolated water bodies. Areas of all indigenous fish species are become disconnected. Reduction of habitats goes relatively slow for naked osman Gymnodiptychus dybowskii (Kessler, 1874, spotted thicklip loach Triplophysa strauchii (Kessler, 1874, and gray loach Triplophysa dorsalis (Kessler, 1872. Drastic reductions of areas were revealed for Ili marinka Schizothorax pseudoaksaiensis Herzenstein 1889, Balkhash marinka Schizothorax argentatus Kessler 1874, Severtsov’s loach Triplophysa sewerzowii (G.Nikolskii, 1938, Seven River’s minnow Phoxinus brachyurus Berg 1912, Balkhsh minnow Rhynchocypris poljakowii Kessler 1879, and Balkhash perch Perca schrenkii Kessler 1874. Marinkas, osmans and perch often become victims of overfishing and poaching of local people. In that region water resources usually are used by wasteful way and loaded with pollutants. Many indigenous fish species are able to bear relatively high level of environment pollution. Hence, the main threats for indigenous fishes are introductions of trout and sander, habitats lose and unstable hydrological regimen.

  20. Grades of 43 Fish Species in Japan Based on IgE-binding Activity

    Directory of Open Access Journals (Sweden)

    Harumi Koyama

    2006-01-01

    Conclusions: A correlation was observed between IgE levels and expression of symptoms after fish ingestion. High consumption of salmon, tuna, scad (including saurel, skipper, yellowtail, sardine, bonita and mackerel in Japan might be the cause of the high IgE-binding activity of these species. The grades of fish species consumed widely in Japan are likely to be useful for nutritional instruction of fish-allergic patients.

  1. The differentiation of common species in a coral-reef fish assemblage for recreational scuba diving

    OpenAIRE

    Chen, Tsen-Chien; Ho, Cheng-Tze; Jan, Rong-Quen

    2016-01-01

    Background Recreational scuba diving is a popular activity of the coral reef tourism industry. In practice, local diving centers recommend interesting sites to help visiting divers make their plans. Fish are among the major attractions, but they need to be listed with care because the temporal occurrence of a fish species is difficult to predict. To address this issue, we propose methods to categorize each fish species based on its long-term occurrence and likelihood of being seen. Methods We...

  2. Jointness through fishing days input in a multi-species fishery

    DEFF Research Database (Denmark)

    Hansen, Lars Gårn; Jensen, Carsten Lynge

    .g. translog, normalized quadratic). In this paper we argue that jointness in the latter, essentially separable fishery is caused by allocation of fishing days input among harvested species. We developed a structural model of a multi-species fishery where the allocation of fishing days input causes production...

  3. 78 FR 23222 - Endangered and Threatened Species; Take of Anadromous Fish

    Science.gov (United States)

    2013-04-18

    ... DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration RIN 0648-XC630 Endangered and Threatened Species; Take of Anadromous Fish AGENCY: NOAA's National Marine Fisheries Service (NMFS... CFR parts 222-226) governing listed fish and wildlife permits. Species Covered in This Notice This...

  4. Determining spatio-temporal distribution of bee forage species of Al-Baha region based on ground inventorying supported with GIS applications and Remote Sensed Satellite Image analysis

    Directory of Open Access Journals (Sweden)

    Nuru Adgaba

    2017-07-01

    Full Text Available In arid zones, the shortage of bee forage is critical and usually compels beekeepers to move their colonies in search of better forages. Identifying and mapping the spatiotemporal distribution of the bee forages over given area is important for better management of bee colonies. In this study honey bee plants in the target areas were inventoried following, ground inventory work supported with GIS applications. The study was conducted on 85 large plots of 50 × 50 m each. At each plot, data on species name, height, base diameter, crown height, crown diameter has been taken for each plant with their respective geographical positions. The data were stored, and processed using Trimble GPS supported with ArcGIS10 software program. The data were used to estimate the relative frequency, density, abundance and species diversity, species important value index and apicultural value of the species. In addition, Remotely Sensed Satellite Image of the area was obtained and processed using Hopfield Artificial Neural Network techniques. During the study, 182 species from 49 plant families were identified as bee forages of the target area. From the total number of species; shrubs, herbs and trees were accounting for 61%, 27.67%, and 11.53% respectively. Of which Ziziphus spina-christi, Acacia tortilis, Acacia origina, Acacia asak, Lavandula dentata, and Hypoestes forskaolii were the major nectar source plants of the area in their degree of importance. The average vegetation cover values of the study areas were low (<30% with low Shannon’s species diversity indices (H′ of 0.5–1.52 for different sites. Based on the eco-climatological factors and the variations in their flowering period, these major bee forage species were found to form eight distinct spatiotemporal categories which allow beekeepers to migrate their colonies to exploit the resources at different seasons and place. The Remote Sensed Satellite Image analysis confirmed the spatial

  5. Determining spatio-temporal distribution of bee forage species of Al-Baha region based on ground inventorying supported with GIS applications and Remote Sensed Satellite Image analysis.

    Science.gov (United States)

    Adgaba, Nuru; Alghamdi, Ahmed; Sammoud, Rachid; Shenkute, Awraris; Tadesse, Yilma; Ansari, Mahammad J; Sharma, Deepak; Hepburn, Colleen

    2017-07-01

    In arid zones, the shortage of bee forage is critical and usually compels beekeepers to move their colonies in search of better forages. Identifying and mapping the spatiotemporal distribution of the bee forages over given area is important for better management of bee colonies. In this study honey bee plants in the target areas were inventoried following, ground inventory work supported with GIS applications. The study was conducted on 85 large plots of 50 × 50 m each. At each plot, data on species name, height, base diameter, crown height, crown diameter has been taken for each plant with their respective geographical positions. The data were stored, and processed using Trimble GPS supported with ArcGIS10 software program. The data were used to estimate the relative frequency, density, abundance and species diversity, species important value index and apicultural value of the species. In addition, Remotely Sensed Satellite Image of the area was obtained and processed using Hopfield Artificial Neural Network techniques. During the study, 182 species from 49 plant families were identified as bee forages of the target area. From the total number of species; shrubs, herbs and trees were accounting for 61%, 27.67%, and 11.53% respectively. Of which Ziziphus spina-christi , Acacia tortilis , Acacia origina , Acacia asak , Lavandula dentata , and Hypoestes forskaolii were the major nectar source plants of the area in their degree of importance. The average vegetation cover values of the study areas were low (GIS and satellite image processing techniques could be an important tool for characterizing and mapping the available bee forage resources leading to their efficient and sustainable utilization.

  6. A Mixed-Method Approach for Quantifying Illegal Fishing and Its Impact on an Endangered Fish Species.

    Science.gov (United States)

    Free, Christopher M; Jensen, Olaf P; Mendsaikhan, Bud

    2015-01-01

    Illegal harvest is recognized as a widespread problem in natural resource management. The use of multiple methods for quantifying illegal harvest has been widely recommended yet infrequently applied. We used a mixed-method approach to evaluate the extent, character, and motivations of illegal gillnet fishing in Lake Hovsgol National Park, Mongolia and its impact on the lake's fish populations, especially that of the endangered endemic Hovsgol grayling (Thymallus nigrescens). Surveys for derelict fishing gear indicate that gillnet fishing is widespread and increasing and that fishers generally use 3-4 cm mesh gillnet. Interviews with resident herders and park rangers suggest that many residents fish for subsistence during the spring grayling spawning migration and that some residents fish commercially year-round. Interviewed herders and rangers generally agree that fish population sizes are decreasing but are divided on the causes and solutions. Biological monitoring indicates that the gillnet mesh sizes used by fishers efficiently target Hovsgol grayling. Of the five species sampled in the monitoring program, only burbot (Lota lota) showed a significant decrease in population abundance from 2009-2013. However, grayling, burbot, and roach (Rutilus rutilus) all showed significant declines in average body size, suggesting a negative fishing impact. Data-poor stock assessment methods suggest that the fishing effort equivalent to each resident family fishing 50-m of gillnet 11-15 nights per year would be sufficient to overexploit the grayling population. Results from the derelict fishing gear survey and interviews suggest that this level of effort is not implausible. Overall, we demonstrate the ability for a mixed-method approach to effectively describe an illegal fishery and suggest that these methods be used to assess illegal fishing and its impacts in other protected areas.

  7. Complete chloroplast genome sequence of a major allogamous forage species, perennial ryegrass (Lolium perenne L.).

    Science.gov (United States)

    Diekmann, Kerstin; Hodkinson, Trevor R; Wolfe, Kenneth H; van den Bekerom, Rob; Dix, Philip J; Barth, Susanne

    2009-06-01

    Lolium perenne L. (perennial ryegrass) is globally one of the most important forage and grassland crops. We sequenced the chloroplast (cp) genome of Lolium perenne cultivar Cashel. The L. perenne cp genome is 135 282 bp with a typical quadripartite structure. It contains genes for 76 unique proteins, 30 tRNAs and four rRNAs. As in other grasses, the genes accD, ycf1 and ycf2 are absent. The genome is of average size within its subfamily Pooideae and of medium size within the Poaceae. Genome size differences are mainly due to length variations in non-coding regions. However, considerable length differences of 1-27 codons in comparison of L. perenne to other Poaceae and 1-68 codons among all Poaceae were also detected. Within the cp genome of this outcrossing cultivar, 10 insertion/deletion polymorphisms and 40 single nucleotide polymorphisms were detected. Two of the polymorphisms involve tiny inversions within hairpin structures. By comparing the genome sequence with RT-PCR products of transcripts for 33 genes, 31 mRNA editing sites were identified, five of them unique to Lolium. The cp genome sequence of L. perenne is available under Accession number AM777385 at the European Molecular Biology Laboratory, National Center for Biotechnology Information and DNA DataBank of Japan.

  8. Seasonal variation of assemblage and feeding guild structure of fish species in a boreal tidal basin

    Science.gov (United States)

    Kellnreitner, Florian; Pockberger, Moritz; Asmus, Harald

    2012-08-01

    Species composition, abundance, feeding relationships and guild structure of the fish assemblage in the Sylt-Rømø bight, a tidal basin in the northern Wadden Sea, were investigated to show seasonal differences and the importance of functional groups in this area. The tidal flats and in shallow subtidal areas were sampled using a beach seine and a bottom trawl net was used for deeper subtidal areas and tidal gullies. Species richness of fish was highest in summer where 26 species were caught, while the lowest richness was recorded in winter (17 species). Clear differences in species richness and abundance were found between shallow areas and deeper parts of the bight. Clupea harengus and Ammodytes tobianus were the most abundant species in deeper areas, while Pomatoschistus microps and Pomatoschistus minutus dominated shallower waters. Gut contents of 27 fish species were identified and the guild structure analyzed by UPGMA clustering of niche overlaps. Calanoid copepods (19.9%), Crangon crangon (18.2%) and mysid shrimps (8.4%) were the most abundant prey items of all fish species combined. Seven feeding guilds were present in the fall and winter, and eight and six in spring and summer, respectively. Fish feeding on calanoid copepods and C. crangon were present year round, whereas the occurrence of other guilds varied between seasons. Species composition of prey changed through seasons and, for some fish species, even the feeding mode itself varied with season. Most noticeable, 11 fish species changed guilds between seasons. We found a convergence in summer towards abundant prey items, whereas in winter diet overlap was lower. This is the first investigation of guild structure of almost all fish species present in a Wadden Sea area, and shows that consideration of seasonal differences is essential when determining feeding relationships of fish in temperate areas.

  9. Total mercury levels in commercial fish species from Italian fishery and aquaculture.

    Science.gov (United States)

    Di Lena, Gabriella; Casini, Irene; Caproni, Roberto; Fusari, Andrea; Orban, Elena

    2017-06-01

    Total mercury levels were measured in 42 commercial fish species caught off the Central Adriatic and Tyrrhenian coasts of Italy and in 6 aquaculture species. The study on wild fish covered species differing in living habitat and trophic level. The study on farmed fish covered marine and freshwater species from intensive and extensive aquaculture and their feed. Mercury levels were analysed by thermal decomposition-amalgamation-atomic absorption spectrophotometry. Total mercury concentrations in the muscle of wild fish showed a high variability among species (0.025-2.20 mg kg -1 wet weight). The lowest levels were detected in low trophic-level demersal and pelagic-neritic fish and in young individuals of high trophic-level species. Levels exceeding the European Commission limits were found in large-size specimens of high trophic-level pelagic and demersal species. Fish from intensive farming showed low levels of total mercury (0.008-0.251 mg kg -1 ). Fish from extensive rearing showed variable contamination levels, depending on the area of provenience. An estimation of the human intake of mercury associated to the consumption of the studied fish and its comparison with the tolerable weekly intake is provided.

  10. Arsenic levels in ten species of fish from the east coat of the Arabian Sea, Pakistan

    International Nuclear Information System (INIS)

    Jaffar, M.; Tariq, J.; Ashraf, M.

    1994-01-01

    Arsenic concentrations are estimated in ten marine fish species from the East Coast of the Arabian Sea, Pakistan, by the atomic absorption method. The following species are included in the study: Picnic seabream, Indian scad, Indian ariomma; Bigeye scad, Threadfins Cornet fish; Lefteye flounder, Goldband goatfish, Smooth dwarf monoclebream and half mourning coraker. A total of 716 fish samples within a preselected narrow weight range and comprising of 5-7 specimens of each species are analysed. Of all the species investigated the maximum concentration (17.602) micro g/g dry weight was found in goldband goatfish. (author)

  11. 78 FR 18273 - Draft Guidance for Industry on Purchasing Reef Fish Species Associated With the Hazard of...

    Science.gov (United States)

    2013-03-26

    .... FDA-2013-D-0269] Draft Guidance for Industry on Purchasing Reef Fish Species Associated With the... availability of a draft guidance entitled ``Guidance for Industry: Purchasing Reef Fish Species Associated With... seafood processors who purchase reef fish how to minimize the risk of ciguatera fish poisoning (CFP) from...

  12. Study of the heavy metal phytoextraction capacity of two forage species growing in an hydroponic environment.

    Science.gov (United States)

    Bonfranceschi, Barros A; Flocco, C G; Donati, E R

    2009-06-15

    Sorghum and alfalfa are two important forage crops. We studied their capacity for accumulating heavy metals in hydroponic experiments. Cadmium, nickel (as divalent cations) and chromium (trivalent and hexavalent) were added individually to the nutrient solution in a range of concentrations from 1 to 80 mg/l. Cr(III) was complexed with EDTA to increase its bioavailability. In alfalfa the increases in the concentration of Cr(III) and Cr(VI) favoured translocation of the metals to the upper parts of the plants, while with Ni(II) the level of translocated metal remained almost unchanged. In sorghum, both Cr(VI) and Ni(II) produced similar results to those in alfalfa, but increases in the concentrations of Cd(II) and Cr(III) in the solution lead to a higher accumulation of the metal at the root level. The concentrations referred to the dry biomass of alfalfa were 500 mg/kg (aerial parts) and 1500 mg/kg (roots) of Cr(III), simultaneously enhancing plant growth. Sorghum captured 500 and 1100 mg/kg (in aerial parts) and 300 and 2000 mg/kg (in roots) for Ni(II) and Cd(II) respectively, without significant damage to its biomass. The results show that alfalfa and sorghum can not only grow in the presence of high heavy metal concentration but also capture and translocate them to the aerial parts; because of these results special attention should be given to these crop plants for their possible use in phytoremediation of large contaminated areas but especially to avoid the possible introduction of the metals accumulated in aerial parts into the food chain when those plants grow in contaminated areas.

  13. Study of the heavy metal phytoextraction capacity of two forage species growing in an hydroponic environment

    Energy Technology Data Exchange (ETDEWEB)

    Bonfranceschi, Barros A. [Centro de Investigacion y Desarrollo en Fermentaciones Industriales (CINDEFI, UNLP-CCT La Plata, CONICET), Facultad de Ciencias Exactas (UNLP), Calle 50 y 115, 1900 La Plata (Argentina); Flocco, C.G. [Consejo Nacional de Investigaciones Cientificas y Tecnologicas (CONICET), Buenos Aires (Argentina); Donati, E.R., E-mail: donati@quimica.unlp.edu.ar [Centro de Investigacion y Desarrollo en Fermentaciones Industriales (CINDEFI, UNLP-CCT La Plata, CONICET), Facultad de Ciencias Exactas (UNLP), Calle 50 y 115, 1900 La Plata (Argentina)

    2009-06-15

    Sorghum and alfalfa are two important forage crops. We studied their capacity for accumulating heavy metals in hydroponic experiments. Cadmium, nickel (as divalent cations) and chromium (trivalent and hexavalent) were added individually to the nutrient solution in a range of concentrations from 1 to 80 mg/l. Cr(III) was complexed with EDTA to increase its bioavailability. In alfalfa the increases in the concentration of Cr(III) and Cr(VI) favoured translocation of the metals to the upper parts of the plants, while with Ni(II) the level of translocated metal remained almost unchanged. In sorghum, both Cr(VI) and Ni(II) produced similar results to those in alfalfa, but increases in the concentrations of Cd(II) and Cr(III) in the solution lead to a higher accumulation of the metal at the root level. The concentrations referred to the dry biomass of alfalfa were 500 mg/kg (aerial parts) and 1500 mg/kg (roots) of Cr(III), simultaneously enhancing plant growth. Sorghum captured 500 and 1100 mg/kg (in aerial parts) and 300 and 2000 mg/kg (in roots) for Ni(II) and Cd(II) respectively, without significant damage to its biomass. The results show that alfalfa and sorghum can not only grow in the presence of high heavy metal concentration but also capture and translocate them to the aerial parts; because of these results special attention should be given to these crop plants for their possible use in phytoremediation of large contaminated areas but especially to avoid the possible introduction of the metals accumulated in aerial parts into the food chain when those plants grow in contaminated areas.

  14. Study of the heavy metal phytoextraction capacity of two forage species growing in an hydroponic environment

    International Nuclear Information System (INIS)

    Bonfranceschi, Barros A.; Flocco, C.G.; Donati, E.R.

    2009-01-01

    Sorghum and alfalfa are two important forage crops. We studied their capacity for accumulating heavy metals in hydroponic experiments. Cadmium, nickel (as divalent cations) and chromium (trivalent and hexavalent) were added individually to the nutrient solution in a range of concentrations from 1 to 80 mg/l. Cr(III) was complexed with EDTA to increase its bioavailability. In alfalfa the increases in the concentration of Cr(III) and Cr(VI) favoured translocation of the metals to the upper parts of the plants, while with Ni(II) the level of translocated metal remained almost unchanged. In sorghum, both Cr(VI) and Ni(II) produced similar results to those in alfalfa, but increases in the concentrations of Cd(II) and Cr(III) in the solution lead to a higher accumulation of the metal at the root level. The concentrations referred to the dry biomass of alfalfa were 500 mg/kg (aerial parts) and 1500 mg/kg (roots) of Cr(III), simultaneously enhancing plant growth. Sorghum captured 500 and 1100 mg/kg (in aerial parts) and 300 and 2000 mg/kg (in roots) for Ni(II) and Cd(II) respectively, without significant damage to its biomass. The results show that alfalfa and sorghum can not only grow in the presence of high heavy metal concentration but also capture and translocate them to the aerial parts; because of these results special attention should be given to these crop plants for their possible use in phytoremediation of large contaminated areas but especially to avoid the possible introduction of the metals accumulated in aerial parts into the food chain when those plants grow in contaminated areas.

  15. 77 FR 75611 - Endangered and Threatened Species; Take of Anadromous Fish

    Science.gov (United States)

    2012-12-21

    ... and Threatened Species; Take of Anadromous Fish AGENCY: National Marine Fisheries Service (NMFS... promulgated under the Endangered Species Act (ESA). The plans specify the propagation of five species of... 10, 2000). Dated: December 17, 2012. Angela Somma, Chief, Endangered Species Division, Office of...

  16. 75 FR 50746 - Endangered and Threatened Species; Take of Anadromous Fish

    Science.gov (United States)

    2010-08-17

    ... and Threatened Species; Take of Anadromous Fish AGENCY: National Marine Fisheries Service (NMFS... is intended to increase knowledge of species listed under the Endangered Species Act (ESA) and to..., Chief, Endangered Species Division, Office of Protected Resources, National Marine Fisheries Service...

  17. 78 FR 6298 - Endangered and Threatened Species; Take of Anadromous Fish; Correction

    Science.gov (United States)

    2013-01-30

    ... and Threatened Species; Take of Anadromous Fish; Correction AGENCY: National Marine Fisheries Service... listed species under the Endangered Species Act of 1973. NMFS also announced the availability for public... provided above in the addresses section. Dated: January 24, 2013. Angela Somma, Chief, Endangered Species...

  18. Species richness and patterns of invasion in plants, birds, and fishes in the United States

    Science.gov (United States)

    Thomas J. Stohlgren; David T. Barnett; Curtis H. Flather; Pam L. Fuller; Bruce G. Peterjohn; John T. Kartesz; Lawrence L. Master

    2006-01-01

    We quantified broad-scale patterns of species richness and species density (mean # species/km2) for native and non-indigenous plants, birds, and fishes in the continental USA and Hawaii. We hypothesized that the species density of native and non-indigenous taxa would generally decrease in northern latitudes and higher elevations following...

  19. Explorations on Temperature, Oxygen, Nutrients and Habitat Demands of Fish Species Found in River Coruh

    Directory of Open Access Journals (Sweden)

    Bilal Akbulut

    2009-04-01

    Full Text Available For the protection of our natural resources, fish species being economic and ecological richness of the natural in the basin of the Çoruh to know their request is extremely a vital important issue. In this study, temperature and oxygen demand, food and habitat of 18 fish species in six families found in river Çoruh assessed and discussed with the literature and database. Limiting the impact of water temperature on the reproductive, growth and nutrition emphasized. The fish species in the basin spawn at temperatures between 14-30°C according to database. Three species belonging to a family feed with animal food floating in the water. The species belonging to the other families more feed mixed with plant and animal foods diet in the floor or near the ground. Importance of their environmental demands has clarified for conservation and sustainable use of these fish species inhabiting in Çoruh River.

  20. Life history strategies of fish species and biodiversity in eastern USA streams

    Science.gov (United States)

    Meador, Michael R.; Brown, Larry M.

    2015-01-01

    Predictive models have been used to determine fish species that occur less frequently than expected (decreasers) and those that occur more frequently than expected (increasers) in streams in the eastern U.S. Coupling life history traits with 51 decreaser and 38 increaser fish species provided the opportunity to examine potential mechanisms associated with predicted changes in fish species distributions in eastern streams. We assigned six life history traits – fecundity, longevity, maturation age, maximum total length, parental care, and spawning season duration – to each fish species. Decreaser species were significantly smaller in size and shorter-lived with reduced fecundity and shorter spawning seasons compared to increaser species. Cluster analysis of traits revealed correspondence with a life history model defining equilibrium (low fecundity, high parental care), opportunistic (early maturation, low parental care), and periodic (late maturation, high fecundity, low parental care) end-point strategies. Nearly 50 % of decreaser species were associated with an intermediate opportunistic-periodic strategy, suggesting that abiotic factors such as habitat specialization and streamflow alteration may serve as important influences on life history traits and strategies of decreaser species. In contrast, the percent of increaser species among life history strategy groups ranged from 21 to 32 %, suggesting that life history strategies of increaser species were more diverse than those of decreaser species. This study highlights the utility of linking life history theory to biodiversity to better understand mechanisms that contribute to fish species distributions in the eastern U.S.

  1. Development of Genomic Resources in the Species of Trifolium L. and Its Application in Forage Legume Breeding

    Directory of Open Access Journals (Sweden)

    Leif Skøt

    2012-05-01

    Full Text Available Clovers (genus Trifolium are a large and widespread genus of legumes. A number of clovers are of agricultural importance as forage crops in grassland agriculture, particularly temperate areas. White clover (Trifolium repens L. is used in grazed pasture and red clover (T. pratense L. is widely cut and conserved as a winter feed. For the diploid red clover, genetic and genomic tools and resources have developed rapidly over the last five years including genetic and physical maps, BAC (bacterial artificial chromosome end sequence and transcriptome sequence information. This has paved the way for the use of genome wide selection and high throughput phenotyping in germplasm development. For the allotetraploid white clover progress has been slower although marker assisted selection is in use and relatively robust genetic maps and QTL (quantitative trait locus information now exist. For both species the sequencing of the model legume Medicago truncatula gene space is an important development to aid genomic, biological and evolutionary studies. The first genetic maps of another species, subterranean clover (Trifolium subterraneum L. have also been published and its comparative genomics with red clover and M. truncatula conducted. Next generation sequencing brings the potential to revolutionize clover genomics, but international consortia and effective use of germplasm, novel population structures and phenomics will be required to carry out effective translation into breeding. Another avenue for clover genomic and genetic improvement is interspecific hybridization. This approach has considerable potential with regard to crop improvement but also opens windows of opportunity for studies of biological and evolutionary processes.

  2. Characterization of the Cultivable Gut Microflora in Wild-Caught 
Mediterranean Fish Species.

    Science.gov (United States)

    Jammal, Ahmad; Bariche, Michel; Zu Dohna, Heinrich; Kambris, Zakaria

    2017-05-01

    Microflora of the gastrointestinal tract plays important roles in food digestion, nutrient absorption and in host defense against ingested pathogens. Several studies have focused on the microflora of farmed fishes, but the gut flora of wild fishes remains poorly characterized. The aim of this work was to provide an overview of the bacteria colonizing the gut of wild-caught fishes and to determine whether some bacterial species can be pathogenic. We isolated cultivable bacteria from fifteen wild-caught Mediterranean fish species corresponding to different habitat, diet and origin. Bacterial species identity was determined by 16s rRNA gene sequencing for the 61 isolates. The potential pathogenicity of isolated bacteria was investigated using fruit fly (Drosophila melanogaster) and zebrafish (Danio rerio) as model organisms. Two bacterial strains (Serratia sp. and Aeromonas salmonicida) were lethal when microinjected to Drosophila, while zebrafish did not develop any disease when exposed to any of 34 isolated bacterial strains. However, it was interesting to note that two bacterial strains (Shewanella and Arthrobacter) isolated from marine fishes were able to colonize the guts of freshwater zebrafish. The results of this study give an overview of the bacterial species found in the guts of wild fishes living off Beirut seashore. It shows that some parameters believed to be limiting factors to host-gut colonization by bacteria can be overcome by some species. This pilot study could be extended by sampling a larger number of fish species with several specimens per fish species, and by identifying uncultivable bacteria that reside in the fish guts. Our results may have implications for the utilization of certain bacterial species in fish farming or their use as bio-indicators for water and/or food quality.

  3. Effects of forest fertilization on nitrate and crude protein content in some important reindeer forage species

    Directory of Open Access Journals (Sweden)

    Gustaf Åhman

    1984-05-01

    Full Text Available When forests are fertilized with ammonia nitrate it is possible that grazing reindeer ingest ammonia nitrate by eating grains of fertilizer from the ground or by drinking contaminated water. They can also get nitrate through plants that have absorbed and disposed nitrate. This latter factor is studied in this report. In addition the effect of fertilization on crude protein content in forage plants is investigated. Fertilizing trials were done within two different areas. One was a dry scotch pine forest and the other a humid scotch pine forest. Both were situated 10 to 15 km north west of Lycksele (northern Sweden. Three different rations (75, 150 and 250 kg N/ha of ammonianitrate and one (150 kg N/ha of urea was used. Fertilization was done at two occations, in June and in July. To investigate the effect of fertilization on nitrate and crude protein content in reindeer forage plants, samples were taken of reindeer lichens (Cladina spp., heather {Calluna vulgaris, crowberry (Empetrum spp., cowberry (Vaccinium vitis ideae, blueberry (Vaccinium myrtillus and hair-grass (Deschampsia flexuosa at different times after fertilization. In this trial we could not find any higher degree of contamination of nitrate in lichens. The highest value was 0.013% nitrate-N in dry matter (table 1. Nitrate accumulation was low in shrubs and grass (table 2. The highest value (0.05% was found in heather. The concentrations were definitly below the level that could be considered as injurious to the reindeer. The effect of fertilization on crude protein content in reindeer forage plants was obvious. It was most evident in hair-grass. Four weeks after fertilization with 150 kg N/ha, crude protein content was more than doubled and reached 20% in dry matter (figure 1 and 2. In withered hair-grass in the autumn the effect was very small. One year after fertilization a small rise in crude protein was registered in both grass and shrubs (table 3. Some effect still remained

  4. More Than Just a Spawning Location: Examining Fine Scale Space Use of Two Estuarine Fish Species at a Spawning Aggregation Site

    Directory of Open Access Journals (Sweden)

    Ross E. Boucek

    2017-11-01

    Full Text Available Many species that provide productive marine fisheries form spawning aggregations. Aggregations are predictable both in time and space and constitute nearly all of the reproductive activity for these species. For species that spend weeks to months on spawning aggregation sites, individuals may need to rely on a forage base at or near the spawning site to balance the high energetic cost associated with reproduction. Here, we ask: do spawning fish with protracted spawning seasons use spawning aggregation sites more or less than adjacent foraging habitats? To answer our research question, we tracked 30 Snook (Centropomus undecimalis and 29 Spotted Seatrout (Cynoscion nebulosus at a spawning site during the 2007 spawning season in Tampa Bay (FL, U.S. using acoustic telemetry. We quantified the amount of time both males and females of both species spent in various habitats with network analyses. Surprisingly, results from network analyses revealed that receivers with the highest edge densities for Snook and Seatrout occurred within the seagrass habitat, not the location of spawning. Likewise, we found that both Snook and Seatrout during the spawning season were using the seagrass habitat near the spawning site as much, or more than the location where spawning occurs. Our results show that if protected areas are formed based on only where spawning occurs, the reproductive stock will not be protected from fishing. Further, our results suggest that spawning aggregation sites and areas surrounding used by fishes, may have multiple ecological functions (i.e., larval dispersal and energy provisioning that may need to be considered in conservation actions. Our case study further supports hypotheses put forth in previous work that suggest we must consider more than just spawning sites in protected area development and ecological conservation.

  5. Functional diversity measures revealed impacts of non-native species and habitat degradation on species-poor freshwater fish assemblages.

    Science.gov (United States)

    Colin, Nicole; Villéger, Sébastien; Wilkes, Martin; de Sostoa, Adolfo; Maceda-Veiga, Alberto

    2018-06-01

    Trait-based ecology has been developed for decades to infer ecosystem responses to stressors based on the functional structure of communities, yet its value in species-poor systems is largely unknown. Here, we used an extensive dataset in a Spanish region highly prone to non-native fish invasions (15 catchments, N=389 sites) to assess for the first time how species-poor communities respond to large-scale environmental gradients using a taxonomic and functional trait-based approach in riverine fish. We examined total species richness and three functional trait-based indices available when many sites have ≤3 species (specialization, FSpe; originality, FOri and entropy, FEnt). We assessed the responses of these taxonomic and functional indices along gradients of altitude, water pollution, physical habitat degradation and non-native fish biomass. Whilst species richness was relatively sensitive to spatial effects, functional diversity indices were responsive across natural and anthropogenic gradients. All four diversity measures declined with altitude but this decline was modulated by physical habitat degradation (richness, FSpe and FEnt) and the non-native:total fish biomass ratio (FSpe and FOri) in ways that varied between indices. Furthermore, FSpe and FOri were significantly correlated with Total Nitrogen. Non-native fish were a major component of the taxonomic and functional structure of fish communities, raising concerns about potential misdiagnosis between invaded and environmentally-degraded river reaches. Such misdiagnosis was evident in a regional fish index widely used in official monitoring programs. We recommend the application of FSpe and FOri to extensive datasets from monitoring programs in order to generate valuable cross-system information about the impacts of non-native species and habitat degradation, even in species-poor systems. Scoring non-native species apart from habitat degradation in the indices used to determine ecosystem health is

  6. [Seasonal changes of fish species composition and diversity in mudflat wetlands of Hangzhou Bay].

    Science.gov (United States)

    Jia, Xing-huan; Zhang, Heng; Jiang, Ke-yi; Wu, Ming

    2010-12-01

    In order to understand the spatiotemporal variation of fish species composition and biodiversity in the mudflat wetlands of Hangzhou Bay, thirty six surveys were conducted in the mudflat area, inning area, and aquaculture area in the south bank of the Bay in. March (early spring), May (spring), July (summer), and October (autumn), 2009. A total of 41 species belonging to 9 orders and 16 families were observed, among which, Cyprinid had the largest species number (14 species, 33.3% of the total), followed by Gobiidae (8 species, 19.1%). According to the lifestyle of fish, these 41 species could be divided into five ecological types, i.e., freshwater type (21 species), brackish-water type (16 species), inshore type (2 species), anadromous type (Coilia ectenes), and catadromios type (Anguilla japonica). The fish abundance was the highest (54. 5 fish per net) in summer, followed by in spring and autumn, and the lowest (17.7 fish per net) in early spring. In the three habitats, mudflat area and inning area had the similar seasonal change of fish abundance, i.e., the lowest in early spring, the highest in summer, and then decreased in autumn. Only two or three species were the dominant species in different seasons. In mudflat area, the dominant species were Mugil cephalus and Liza carinatus; while in inning and aquaculture areas, the dominant species were Carassius auratus, Hemiculter leucisculus, and Pseudorasbora parva. The values of Margalef's richness index (D), Pielou's evenness index (J), and Shannon index (H) were lower in March than in other months, but had no significant differences among May, July, and October (P > 0.05). The H value ranged in 0. 27-2. 13, being the lowest in March and higher in May and October (1.66 and 1.63, respectively). Overall, the fish abundance and biodiversity in the mudflat wetlands of Hangzhou Bay had apparent seasonal changes.

  7. Targeting Abundant Fish Stocks while Avoiding Overfished Species: Video and Fishing Surveys to Inform Management after Long-Term Fishery Closures

    Science.gov (United States)

    2016-01-01

    Historically, it has been difficult to balance conservation goals and yield objectives when managing multispecies fisheries that include stocks with various vulnerabilities to fishing. As managers try to maximize yield in mixed-stock fisheries, exploitation rates can lead to less productive stocks becoming overfished. In the late 1990s, population declines of several U.S. West Coast groundfish species caused the U.S. Pacific Fishery Management Council to create coast-wide fishery closures, known as Rockfish Conservation Areas, to rebuild overfished species. The fishery closures and other management measures successfully reduced fishing mortality of these species, but constrained fishing opportunities on abundant stocks. Restrictive regulations also caused the unintended consequence of reducing fishery-dependent data available to assess population status of fished species. As stocks rebuild, managers are faced with the challenge of increasing fishing opportunities while minimizing fishing mortality on rebuilding species. We designed a camera system to evaluate fishes in coastal habitats and used experimental gear and fishing techniques paired with video surveys to determine if abundant species could be caught in rocky habitats with minimal catches of co-occurring rebuilding species. We fished a total of 58 days and completed 741 sets with vertical hook-and-line fishing gear. We also conducted 299 video surveys in the same locations where fishing occurred. Comparison of fishing and stereo-video surveys indicated that fishermen could fish with modified hook-and-line gear to catch abundant species while limiting bycatch of rebuilding species. As populations of overfished species continue to recover along the U.S. West Coast, it is important to improve data collection, and video and fishing surveys may be key to assessing species that occur in rocky habitats. PMID:28002499

  8. 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.

  9. The diet and consumption of dominant fish species in the upper Scheldt estuary, Belgium

    DEFF Research Database (Denmark)

    Maes, J.; De Brabandere, Loreto; Ollevier, F.

    2003-01-01

    Seasonal changes in the diet composition and trophic niche overlap were examined for the dominant members of the fish assemblage of the turbid low-salinity zone of the Scheldt estuary (Belgium). Samples of fish were taken in the cooling water of a power plant. Juveniles of eight species dominated...... of trophic niche overlap showed that, in general, niche overlap between individuals of the same species was significantly higher than overlap between individuals from different species, suggesting that the available food resources were partitioned. The total annual prey consumption by the dominant fish...

  10. Warming impacts on fish species composition in the Kattegat-Belt Sea

    DEFF Research Database (Denmark)

    Bryndum, Karoline Minna; MacKenzie, Brian

    Sea temperatures have been rising in the waters near Denmark during the past 1-2 decades and are expected to affect marine populations, species, communities and foodwebs. Here we investigate whether and how the species richness and composition of the marine fish community in the Kattegat and Belt...... of the southern range limits of all species captured in the surveys shows that the mean southern latitudinal limit of the fish community has been decreasing and is also corrrelated with bottom temperatures; these patterns are consistent with immigration of fish from southerly zoogeographic regions. Warm...

  11. Na and K Levels in forage species from the communal grazing lands during the dry season at some locations in the Northern Region of Ghana

    Energy Technology Data Exchange (ETDEWEB)

    Gomda, Y M; Osae, E K; Akaho, E H.K. [Ghana Atomic Energy Commission, Accra (Ghana); Fianu, F K [University of Ghana, Legon, Accra, (Ghana); Karbo, N [Animal Research Institute, Nyankpala (Ghana)

    1999-09-01

    Forage species were taken, during the dry season, from five districts in the Northern Region of Ghana and analysed for Na and K using the Neutron Activation Analysis (NAA) technique. The Na level varied in plants species as well as location. The level ranged between 0.049 g/kg DM and 1.14 g/kg DM. This was found to be inadequate for the animals and require supplementation during the dry season. Potassium level in the forage species was between 7.8 to 91.3g/kg DM and appeared to be adequate for the grazing animals. (author) Technical report for year ending 1998. 2 tabs.; 18 refs.

  12. Resource partitioning within major bottom fish species in a highly productive upwelling ecosystem

    Science.gov (United States)

    Abdellaoui, Souad; El Halouani, Hassan; Tai, Imane; Masski, Hicham

    2017-09-01

    The Saharan Bank (21-26°N) is a wide subtropical continental shelf and a highly productive upwelling ecosystem. The bottom communities are dominated by octopus and sparid fish, which are the main targets of bottom-trawl fishing fleets. To investigate resource partitioning within the bottom fish community, adult fish from 14 of the most abundant species were investigated for stomach content analysis. Samples were collected during two periods: October 2003 and May 2007. The diet of the analysed species showed more variation between periods than between size classes, suggesting that temporal or spatial variability in prey availability appears to play a significant role in their diet. Multivariate analysis and subsequent clustering led to a grouping of the species within five trophic guilds. Two species were fish feeders, and the others mainly fed on benthic invertebrates, where epibenthic crustaceans, lamellibranchs and fish were the most important groups in defining trophic guilds. We found that the studied species had a high rate of overlapping spatial distributions and overlapping trophic niches. In this highly productive upwelling ecosystem, where food resources may not be a limiting factor, inter-specific competition did not appear to be an important factor in structuring bottom fish communities. For the species that showed differences in the proportions of prey categories in comparison with other ecosystems, the rise of the proportion of epibenthic crustaceans in their diet was a common feature; a possible consequence of the benthic productivity of this highly productive upwelling ecosystem.

  13. Temporal comparison and predictors of fish species abundance and richness on undisturbed coral reef patches

    Directory of Open Access Journals (Sweden)

    Elena L.E.S. Wagner

    2015-12-01

    Full Text Available Large disturbances can cause rapid degradation of coral reef communities, but what baseline changes in species assemblages occur on undisturbed reefs through time? We surveyed live coral cover, reef fish abundance and fish species richness in 1997 and again in 2007 on 47 fringing patch reefs of varying size and depth at Mersa Bareika, Ras Mohammed National Park, Egypt. No major human or natural disturbance event occurred between these two survey periods in this remote protected area. In the absence of large disturbances, we found that live coral cover, reef fish abundance and fish species richness did not differ in 1997 compared to 2007. Fish abundance and species richness on patches was largely related to the presence of shelters (caves and/or holes, live coral cover and patch size (volume. The presence of the ectoparasite-eating cleaner wrasse, Labroides dimidiatus, was also positively related to fish species richness. Our results underscore the importance of physical reef characteristics, such as patch size and shelter availability, in addition to biotic characteristics, such as live coral cover and cleaner wrasse abundance, in supporting reef fish species richness and abundance through time in a relatively undisturbed and understudied region.

  14. Fish species composition, density-distribution patterns, and impingement during upwelling

    International Nuclear Information System (INIS)

    Spigarelli, S.A.; Sharma, R.K.

    1975-01-01

    The effects of cooling system intakes and discharges on Lake Michigan fishes are highly dependent on inshore species composition and spatial distribution which, in turn, are affected by natural hydrological conditions. Significant (5 to 10 C) short-term decreases in water temperature (due to upwelling) could cause cold shock in fish equilibrated to either ambient or plume temperatures; substantial changes in distribution due to avoidance or attraction responses; and resultant changes in susceptibility to impingement. The objectives of this study are to characterize the changes in fish species composition, density, and thermal distribution as a result of natural upwellings, and to relate these factors to intake and discharge effects. Day and night sampling was conducted in ambient (reference) and thermal plume waters near the Zion Nuclear Plant on four occasions between 17 July and 11 September 1975. Density-distribution patterns and species composition of fish were determined by means of gill nets, bottom trawls, seines, and a sonic fish locater

  15. [Species composition, diversity and density of small fishes in two different habitats in Niushan Lake].

    Science.gov (United States)

    Ye, Shao-Wen; Li, Zhong-Jie; Cao, Wen-Xuan

    2007-07-01

    This paper studied the spatial distribution of small fishes in a shallow macrophytic lake, Niushan Lake in spring 2003, and its relations with habitat heterogeneity. Based on the macrophyte cover condition, distance from lake shore and water depth, two representative habitat types in the lake were selected. Habitat A was near the shore with dense submersed macrophyte, while habitat B was far from the shore with sparse submersed macrophyte. Small fishes were sampled quantitatively by block net (180 m2), and their densities within the net area were estimated by multiple mark-recapture or Zippin's removal method. The results showed that there were some differences in species composition, biodiversity measurement, and estimated density of small fishes between the two habitats: 1) the catches in habitat A consisted of 14 small fish species from 5 families, among which, benthopelagic species Rhodeus ocellatus, Paracheilognathus imberbis and Pseudorasbora parva were considered as dominant species, while those in habitat B consisted of 9 small fish species from 3 families, among which, bottom species Rhinogobius giurinus and Micropercops swinhonis were dominant; 2) the Bray-Curtis index between the two small fish communities was 0.222, reflecting their low structure similarity, and no significant difference was observed between their rank/ abundance distributions, both of which belonged to log series distribution; 3) the total density of 9 major species in habitat A was 8.71 ind x m(-2), while that of 5 major species in habitat B was only 3.54 ind x m(-2). The fact that the spatial distribution of the small fishes differed with habitats might be related to their habitat need for escaping predators, feeding, and breeding, and thus, aquatic macrophyte habitat should be of significance in the rational exploitation of small fish resources as well as the conservation of fish resource diversity.

  16. Diversitas Dan Hilangnya Jenis-jenis Ikan Disungai Ciliwung Dan Sungai Cisadane [Study of Fish Diversity and the Lost of Fish Species of River Ciliwung and R. Cisadane

    OpenAIRE

    Hadiaty, Renny Kurnia

    2011-01-01

    The fish research in Indonesian waters has been begun since 16 century ago. Most of the research collected fish around Batavia.Many new species was described and the type specimens deposited at the museums in Europe or America.The study of fish diversity and the lost of fish species was conducted at River Ciliwung and R. Cisadane in 2009. The aim of this study is to describe the recent fish diversity in both river drainages, then make a comparison with the number of species recorded based on ...

  17. Threatened and Endangered Freshwater Fish and Mussel Species Richness

    Data.gov (United States)

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

  18. Nutrient composition of important fish species in Bangladesh and potential contribution to recommended nutrient intakes

    DEFF Research Database (Denmark)

    Bogard, Jessica R.; Thilsted, Shakuntala H.; Marks, Geoffrey C.

    2015-01-01

    Fish, in Bangladesh where malnutrition remains a significant development challenge, is an irreplaceable animal-source food in the diet of millions. However, existing data on the nutrient composition of fish do not reflect the large diversity available and have focused on only a few select nutrien...... indigenous species, which should guide policy and programmes to improve food and nutrition security in Bangladesh....

  19. Food and feeding habits of four selected fish species in Cross River ...

    African Journals Online (AJOL)

    The food and feeding habits of four fish species: Citharinus latus, Ethmalosa fimbriata, Hepsetus odoe and Trichiurus lepturus, from the Cross River Estuary, Nigeria were investigated. In studying the diets and feeding habits of the fishes, both the frequency of occurrence and numerical methods were used. Results show that ...

  20. The intertidal fish fauna of the west coast of South Africa - species ...

    African Journals Online (AJOL)

    1991-11-05

    Nov 5, 1991 ... elucidated by means of stepwise multiple regression, both at the whole community and individual species levels. ... and were selected to represent the full range of pool parame- ... fish and the total mass of fish caught as dependent variables .... 'bi- and tri-modal' vertical zonation patterns at Groenrivier.

  1. 75 FR 75458 - Atlantic Highly Migratory Species; Exempted Fishing, Scientific Research, Display, and Chartering...

    Science.gov (United States)

    2010-12-03

    ... Highly Migratory Species; Exempted Fishing, Scientific Research, Display, and Chartering Permits; Letters... intent to issue Exempted Fishing Permits (EFPs), Scientific Research Permits (SRPs), Display Permits... of HMS for public display and scientific research that is exempt from regulations (e.g., seasons...

  2. 76 FR 5338 - Endangered and Threatened Species; Take of Anadromous Fish

    Science.gov (United States)

    2011-01-31

    ... DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration RIN 0648-XA183 Endangered and Threatened Species; Take of Anadromous Fish AGENCY: National Marine Fisheries Service (NMFS... regulations (50 CFR parts 222-226) governing listed fish and wildlife permits. [[Page 5339

  3. 78 FR 77659 - Endangered and Threatened Species; Take of Anadromous Fish

    Science.gov (United States)

    2013-12-24

    ... DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration RIN 0648-XD040 Endangered and Threatened Species; Take of Anadromous Fish AGENCY: National Marine Fisheries Service (NMFS... NMFS regulations (50 CFR parts 222-226) governing listed fish and wildlife permits. [[Page 77660...

  4. 76 FR 5339 - Endangered and Threatened Species; Take of Anadromous Fish

    Science.gov (United States)

    2011-01-31

    ... DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration RIN 0648-XA182 Endangered and Threatened Species; Take of Anadromous Fish AGENCY: National Marine Fisheries Service (NMFS... are issued in accordance with and are subject to the ESA and NMFS regulations governing listed fish...

  5. 77 FR 2037 - Endangered and Threatened Species; Take of Anadromous Fish

    Science.gov (United States)

    2012-01-13

    ... DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration RIN 0648-XA928 Endangered and Threatened Species; Take of Anadromous Fish AGENCY: National Marine Fisheries Service (NMFS... advises the public that a direct take permit has been issued to the Washington Department of Fish and...

  6. 76 FR 6401 - Endangered and Threatened Species; Take of Anadromous Fish

    Science.gov (United States)

    2011-02-04

    ... DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration RIN 0648-XA110 Endangered and Threatened Species; Take of Anadromous Fish AGENCY: National Marine Fisheries Service (NMFS... and the Washington Department of Fish and Wildlife submitted to NMFS, pursuant to the protective...

  7. 77 FR 67796 - Endangered and Threatened Species; Take of Anadromous Fish

    Science.gov (United States)

    2012-11-14

    ... DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration RIN 0648-XC342 Endangered and Threatened Species; Take of Anadromous Fish AGENCY: National Marine Fisheries Service (NMFS... NMFS regulations governing listed fish and wildlife permits (50 CFR parts 222-226). Those individuals...

  8. Species succession and sustainability of the Great Lakes fish community

    Science.gov (United States)

    Eshenroder, Randy L.; Burnham-Curtis, Mary K.; Taylor, William W.; Ferreri, C. Paola

    1999-01-01

    This article concentrates on the sustainability of the offshore pelagic and deepwater fish communities that were historically dominated by lake trout (Salvelinus namaycush). The causes of alteration in these fish communities (i.e., overfishing, introductions, and cultural eutrophication) were identified by Loftus and Regier (1972). Here we look at the ecology of these altered communities in relation to sustainability and discuss the need for restoration.

  9. The differentiation of common species in a coral-reef fish assemblage for recreational scuba diving.

    Science.gov (United States)

    Chen, Tsen-Chien; Ho, Cheng-Tze; Jan, Rong-Quen

    2016-01-01

    Recreational scuba diving is a popular activity of the coral reef tourism industry. In practice, local diving centers recommend interesting sites to help visiting divers make their plans. Fish are among the major attractions, but they need to be listed with care because the temporal occurrence of a fish species is difficult to predict. To address this issue, we propose methods to categorize each fish species based on its long-term occurrence and likelihood of being seen. We assume that there are K categories of occurrence of a fish assemblage and propose two methods [an arithmetic-mean method (AM) and a geometric-mean method (GM)] to define the range of species in each category. Experiments based on long term datasets collected at three underwater stations (each having 51-53 surveys and totals of 262-284 fish species) on coral reefs in southern Taiwan showed that when K = 4 (rare, occasional, frequent and common categories), 11-14 species were concurrently assigned to the common category by AM for data sets based on surveys 10, 15, 20, 25, 30, 35, 40, 45, or 51-53 in contrast to the 18-26 species assigned as common by GM. If a similarity index of 0.7 (compared to the total pool of fish species) was the minimum threshold for diver satisfaction, then 20-25 surveys provide sufficient data for listing the common species at a given dive spot. Common fish species, are the most temporally stable, and thus are more appropriate for attracting divers. These can be effectively differentiated by either AM or GM with at least 25 surveys. We suggest regular updating of each fish's category through periodic surveys to assure the accuracy of information at a particular dive spot.

  10. Spawning and nursery habitats of neotropical fish species in the tributaries of a regulated river

    Science.gov (United States)

    Makrakis, Maristela Cavicchioli; da Silva, Patrícia S.; Makrakis, Sergio; de Lima, Ariane F.; de Assumpção, Lucileine; de Paula, Salete; Miranda, Leandro E.; Dias, João Henrique Pinheiro

    2012-01-01

    This chapter provides information on ontogenetic patterns of neotropical fish species distribution in tributaries (Verde, Pardo, Anhanduí, and Aguapeí rivers) of the Porto Primavera Reservoir, in the heavily dammed Paraná River, Brazil, identifying key spawning and nursery habitats. Samplings were conducted monthly in the main channel of rivers and in marginal lagoons from October through March during three consecutive spawning seasons in 2007-2010. Most species spawn in December especially in Verde River. Main river channels are spawning habitats and marginal lagoons are nursery areas for most fish, mainly for migratory species. The tributaries have high diversity of larvae species: a total of 56 taxa representing 21 families, dominated by Characidae. Sedentary species without parental care are more abundant (45.7%), and many long-distance migratory fish species are present (17.4%). Migrators included Prochilodus lineatus, Rhaphiodon vulpinus, Hemisorubim platyrhynchos, Pimelodus maculatus, Pseudoplatystoma corruscans, Sorubim lima, two threatened migratory species: Salminus brasiliensis and Zungaro jahu, and one endangered migratory species: Brycon orbignyanus. Most of these migratory species are vital to commercial and recreational fishing, and their stocks have decreased drastically in the last decades, attributed to habitat alteration, especially impoundments. The fish ladder at Porto Primavera Dam appears to be playing an important role in re-establishing longitudinal connectivity among critical habitats, allowing ascent to migratory fish species, and thus access to upstream reaches and tributaries. Establishment of Permanent Conservation Units in tributaries can help preserve habitats identified as essential spawning and nursery areas, and can be key to the maintenance and conservation of the fish species in the Paraná River basin.

  11. 76 FR 43986 - Endangered and Threatened Species; Take of Anadromous Fish

    Science.gov (United States)

    2011-07-22

    ... and Threatened Species; Take of Anadromous Fish AGENCY: National Marine Fisheries Service (NMFS..., in the form of Hatchery and Genetic Management Plans (HGMPs) pursuant to the Endangered Species Act... the ``taking'' of a species listed as endangered or threatened. The term ``take'' is defined under the...

  12. 77 FR 41168 - Endangered and Threatened Species; Take of Anadromous Fish

    Science.gov (United States)

    2012-07-12

    ... and Threatened Species; Take of Anadromous Fish AGENCY: National Marine Fisheries Service (NMFS... available for review pursuant to section 10(c) of the Endangered Species Act (ESA). DATES: Comments and... the ESA. NMFS regulations governing permits for threatened and endangered species are promulgated at...

  13. 75 FR 14133 - Endangered and Threatened Species; Take of Anadromous Fish

    Science.gov (United States)

    2010-03-24

    ... and Threatened Species; Take of Anadromous Fish AGENCY: National Marine Fisheries Service (NMFS..., in the form of Hatchery and Genetic Management Plans (HGMPs) pursuant to the Endangered Species Act... the ``taking'' of a species listed as endangered or threatened. The term ``take'' is defined under the...

  14. 77 FR 21084 - Endangered and Threatened Species; Take of Anadromous Fish

    Science.gov (United States)

    2012-04-09

    ... and Threatened Species; Take of Anadromous Fish AGENCY: National Marine Fisheries Service (NMFS... under the Endangered Species Act (ESA). The proposed research program is intended to increase knowledge.... Lisa Manning, Acting Chief, Endangered Species Division, Office of Protected Resources, National Marine...

  15. 75 FR 82212 - Endangered and Threatened Species; Take of Anadromous Fish

    Science.gov (United States)

    2010-12-29

    ... and Threatened Species; Take of Anadromous Fish AGENCY: National Marine Fisheries Service (NMFS... Chinook salmon under Limit 6 of the Endangered Species Act (ESA) 4(d) Rule for salmon and steelhead, a.... Dated: December 22, 2010. Susan Pultz, Acting Chief, Endangered Species Division, Office of Protected...

  16. 76 FR 61344 - Endangered and Threatened Species; Take of Anadromous Fish

    Science.gov (United States)

    2011-10-04

    ... and Threatened Species; Take of Anadromous Fish AGENCY: National Marine Fisheries Service (NMFS... modifications, as required by the Endangered Species Act of 1973 (16 U.S.C. 1531-1543) (ESA), is based on a.... Species Covered in This Notice This notice is relevant to federally endangered Central California Coast...

  17. 75 FR 14132 - Endangered and Threatened Species; Take of Anadromous Fish

    Science.gov (United States)

    2010-03-24

    ... and Threatened Species; Take of Anadromous Fish AGENCY: National Marine Fisheries Service (NMFS... Endangered Species Act of 1973, as amended (ESA). The proposed modification is to extend the existing permit... regulations prohibit the ``taking'' of a species listed as endangered or threatened. The term ``take'' is...

  18. 76 FR 39856 - Endangered and Threatened Species; Take of Anadromous Fish

    Science.gov (United States)

    2011-07-07

    ... and Threatened Species; Take of Anadromous Fish AGENCY: National Marine Fisheries Service (NMFS... permits and permit modifications, as required by the Endangered Species Act of 1973 (16 U.S.C. 1531-1543... and wildlife permits. Species Covered in This Notice This notice is relevant to federally endangered...

  19. 77 FR 27188 - Endangered and Threatened Species; Take of Anadromous Fish

    Science.gov (United States)

    2012-05-09

    ... and Threatened Species; Take of Anadromous Fish AGENCY: National Marine Fisheries Service (NMFS... regulations promulgated for Pacific salmon and steelhead under the Endangered Species Act (ESA). The HGMPs...). Dated: May 3, 2012. Angela Somma, Chief, Endangered Species Division, Office of Protected Resources...

  20. 76 FR 20956 - Endangered and Threatened Species; Take of Anadromous Fish

    Science.gov (United States)

    2011-04-14

    ... and Threatened Species; Take of Anadromous Fish AGENCY: National Marine Fisheries Service (NMFS... regulations promulgated for salmon and steelhead listed under the Endangered Species Act (ESA). The FMEP... July 10, 2000, Endangered Species Act (ESA) 4(d) rule for salmon and steelhead (65 FR 42422) and...

  1. α-Tocopherol and β-carotene contents of forage species in four-cut system

    DEFF Research Database (Denmark)

    Lindquist, H.; Nadeau, A.; Jensen, Søren Krogh

    2014-01-01

    α-Tocopherol and β-carotene concentrations were measured in herbage of birdsfoot trefoil (Bft), red clover (Rc), white clover (Wc), timothy (Ti) and perennial ryegrass (Pr) grown in four mixtures (Bft+Ti, Rc+Ti, Rc+Pr and Wc+Pr) in a small-plot field experiment at Foulum, Denmark, over 2 years. P......-carotene concentrations were 54 and 62 mg kg−1 DM. In conclusion, herbage of birdsfoot trefoil generally had higher vitamin concentrations than white or red clover, but differences between the two grass species were small and inconsistent....

  2. Nitrogen transfer from forage legumes to nine neighbouring plants in a multi-species grassland

    DEFF Research Database (Denmark)

    Pirhofer-Walzl, Karin; Rasmussen, Jim; Jensen, Henning Høgh

    2012-01-01

    Legumes play a crucial role in nitrogen supply to grass-legume mixtures for ruminant fodder. To quantify N transfer from legumes to neighbouring plants in multi-species grasslands we established a grass-legume-herb mixture on a loamy-sandy site in Denmark. White clover (Trifolium repens L.), red...... amounts of N from legumes than dicotyledonous plants which generally have taproots. Slurry application mainly increased N transfer from legumes to grasses. During the growing season the three legumes transferred approximately 40 kg N ha-1 to neighbouring plants. Below-ground N transfer from legumes...

  3. Species-specific effects of soil fauna on fungal foraging and decomposition.

    Science.gov (United States)

    Crowther, Thomas W; Boddy, Lynne; Jones, T Hefin

    2011-10-01

    Decomposer fungi are primary decomposing agents in terrestrial soils. Their mycelial networks play an important role in nutrient mineralisation and distribution, but are also nutritious resources for various soil invertebrates. Global climate change is predicted to alter the diversity and community composition of these soil fauna. To understand whether changes in invertebrate species diversity are likely to affect fungal-mediated decomposition, this study compared the grazing potentials of different invertebrate taxa and functional groups. Specifically, the grazing impacts of seven invertebrate taxa on the growth and spatial distribution of six basidiomycete fungi growing from beech wood blocks in soil microcosms were explored. Wood decay rates by fungi were also compared. The consequences of grazing were both taxon- and species-specific. Generally, macro-invertebrates caused the greatest damage, while meso- and micro-invertebrates often stimulated mycelial growth. Invertebrate size, preferences and population dynamics are likely to influence grazing potentials. Effects of grazing varied between fungi, with mycelial morphology and biochemistry possibly influencing susceptibility. Heavy grazing indirectly increased fungal-mediated wood decomposition. Changes in invertebrate community composition are predicted to have consequences for fungal growth, activity and community structure in woodland soils. Abiotic climate change factors including CO(2) and temperature affect mycelial productivity directly, but the indirect effects, mediated through changes in the soil invertebrate community, may be equally important in controlling ecosystem functioning.

  4. BIOMETRY AND COMPOSITION OF FISH SPECIES IN OWENA RESERVOIR, ONDO STATE, NIGERIA

    Directory of Open Access Journals (Sweden)

    FAPOHUNDA Olawumi Oluwafunmilola

    2007-11-01

    Full Text Available A survey of fish species present in Owena reservoir was conducted between October 2004 and March 2005. Fish samples were taken from the catch of the fishermen operating in the reservoir. The results of the survey showed that 14 fish species belonging to seven families were recorded. Two families namely Characidae and Clariidae constituted the dominant fish families in the reservoir. Among the Characidae, Brycinus nurse (23.1% and among the Clariidae family, Clarias gariepinus (22.8% were dominant. Other fish species with significant abundance were Sarotherodon galilaeus (9.3%, Parachanna obscura (8.0%, Clarias anguillaris (7.7% and Oreochromis niloticus (6.4%. The meristic features of the two most abundant fish species caught are as follows: Brycinus nurse had two dorsal spines with eight dorsal fins, two anal spines with eleven anal fins, 25 caudal fins, one pectoral spine and 13 pectoral fins and two ventral spines with seven ventral fins. Clarias gariepinus had 75 dorsal fins, 31 anal fins, 10 caudal fins, six pectoral fins and five ventral fins. The morphometric features of the two most abundant fish species are: Brycinus nurse: total length: 312mm, standard length: 255mm, head length: 60mm, body length: 90mm and body girth: 190mm. Clarias gariepinus: total length: 265mm, standard length: 240mm, head length: 62mm, body length: 62mm and body girth: 130mm.

  5. Diversity of aquatic Pseudomonas species and their activity against the fish pathogenic oomycete Saprolegnia

    NARCIS (Netherlands)

    Liu, Y.; Rzeszutek, E.; Voort, van der M.; Wu, C.H.; Thoen, E.; Skaar, I.; Bulone, V.; Dorrestein, P.C.; Raaijmakers, J.M.; Bruijn, de I.

    2015-01-01

    Emerging fungal and oomycete pathogens are increasingly threatening animals and plants globally. Amongst oomycetes, Saprolegnia species adversely affect wild and cultivated populations of amphibians and fish, leading to substantial reductions in biodiversity and food productivity. With the ban of

  6. Florida Reef Fish Visual Census 1981 Species Site Matrix (NODC Accession 0001394)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set is an ArcView shapefile set that contains locations of sampled coral reef fish species at the National Marine Sanctuary along the Florida Keys. The...

  7. Florida Reef Fish Visual Census 1985 Species Site Matrix (NODC Accession 0001394)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set is an ArcView shapefile set that contains locations of sampled coral reef fish species at the National Marine Sanctuary along the Florida Keys. The...

  8. Florida Reef Fish Visual Census 1994 Species Site Matrix (NODC Accession 0001394)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set is an ArcView shapefile set that contains locations of sampled coral reef fish species at the National Marine Sanctuary along the Florida Keys. The...

  9. Florida Reef Fish Visual Census 1998 Species Site Matrix (NODC Accession 0001394)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set is an ArcView shapefile set that contains locations of sampled coral reef fish species at the National Marine Sanctuary along the Florida Keys. The...

  10. Florida Reef Fish Visual Census 1993 Species Site Matrix (NODC Accession 0001394)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set is an ArcView shapefile set that contains locations of sampled coral reef fish species at the National Marine Sanctuary along the Florida Keys. The...

  11. Florida Reef Fish Visual Census 1996 Species Site Matrix (NODC Accession 0001394)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set is an ArcView shapefile set that contains locations of sampled coral reef fish species at the National Marine Sanctuary along the Florida Keys. The...

  12. Florida Reef Fish Visual Census 1982 Species Site Matrix (NODC Accession 0001394)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set is an ArcView shapefile set that contains locations of sampled coral reef fish species at the National Marine Sanctuary along the Florida Keys. The...

  13. 78 FR 43145 - Endangered and Threatened Species; Take of Anadromous Fish

    Science.gov (United States)

    2013-07-19

    ... DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration RIN 0648-XC767 Endangered and Threatened Species; Take of Anadromous Fish AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and Atmospheric Administration, Commerce. ACTION: Notice of availability. SUMMARY: This...

  14. 78 FR 34653 - Endangered and Threatened Species; Take of Anadromous Fish

    Science.gov (United States)

    2013-06-10

    ... DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration RIN 0648-XC717 Endangered and Threatened Species; Take of Anadromous Fish AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and Atmospheric Administration, Commerce. ACTION: Notice of decision and availability of...

  15. Feeding ecology of some fish species occurring in artisanal fishery of Socotra Island (Yemen).

    Science.gov (United States)

    Hassan Ali', Mohammed Kaed; Belluscio, Andrea; Ventura, Daniele; Ardizzone, Giandomenico

    2016-04-30

    The demersal species Lethrinus borbonicus, Lethrinus mahsena, Lethrinus microdon, Lethrinus nebulosus, Lutjanus bohar, Lutjanus gibbus, Lutjanus kasmira, Epinephelus fasciatus, Epinephelus stoliczkae, Carangoides gymnostethus and Euthynnus affinis are important coastal fishes species of the northern coast of Socotra (Yemen), exploited by local fishery. The biology and feeding ecology of these species are poorly known in the area. A total of 1239 specimens were sampled from the main fishing landing site of the island (Hadibo). Total length and weight were measured, stomach contents were analyzed, diet overlap, Fulton's Condition index, and trophic levels were estimated. C. gymnostethus, L. microdon and L. kasmira occupied the highest position (T=4.50), L. nebulosus occupied the lower one (TL=3.41). The role of the increasing abundance of small pelagic fish in the diet of many species after the upwelling event is evident, but also different feeding strategies are reported, according to fish ecology. Copyright © 2016 Elsevier Ltd. All rights reserved.

  16. Addressing species diversity in biotransformation: variability in expressed transcripts of hepatic biotransformation enzymes among fishes

    Science.gov (United States)

    There is increasing evidence that diverse xenobiotic metabolizing enzymes exist among fishes, potentially resulting in different chemical sensitivities and accumulation, but this has never been systematically evaluated. One concern is that model test species such as rainbow trou...

  17. Florida Reef Fish Visual Census 1984 Species Site Matrix (NODC Accession 0001394)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set is an ArcView shapefile set that contains locations of sampled coral reef fish species at the National Marine Sanctuary along the Florida Keys. The...

  18. Florida Reef Fish Visual Census 1989 Species Site Matrix (NODC Accession 0001394)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set is an ArcView shapefile set that contains locations of sampled coral reef fish species at the National Marine Sanctuary along the Florida Keys. The...

  19. Florida Reef Fish Visual Census 1997 Species Site Matrix (NODC Accession 0001394)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set is an ArcView shapefile set that contains locations of sampled coral reef fish species at the National Marine Sanctuary along the Florida Keys. The...

  20. Florida Reef Fish Visual Census 1983 Species Site Matrix (NODC Accession 0001394)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set is an ArcView shapefile set that contains locations of sampled coral reef fish species at the National Marine Sanctuary along the Florida Keys. The...

  1. Florida Reef Fish Visual Census 1980 Species Site Matrix (NODC Accession 0001394)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set is an ArcView shapefile set that contains locations of sampled coral reef fish species at the National Marine Sanctuary along the Florida Keys. The...

  2. Florida Reef Fish Visual Census 1988 Species Site Matrix (NODC Accession 0001394)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set is an ArcView shapefile set that contains locations of sampled coral reef fish species at the National Marine Sanctuary along the Florida Keys. The...

  3. Florida Reef Fish Visual Census 1992 Species Site Matrix (NODC Accession 0001394)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set is an ArcView shapefile set that contains locations of sampled coral reef fish species at the National Marine Sanctuary along the Florida Keys. The...

  4. Florida Reef Fish Visual Census 1990 Species Site Matrix (NODC Accession 0001394)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set is an ArcView shapefile set that contains locations of sampled coral reef fish species at the National Marine Sanctuary along the Florida Keys. The...

  5. Florida Reef Fish Visual Census 1991 Species Site Matrix (NODC Accession 0001394)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set is an ArcView shapefile set that contains locations of sampled coral reef fish species at the National Marine Sanctuary along the Florida Keys. The...

  6. Florida Reef Fish Visual Census 1986 Species Site Matrix (NODC Accession 0001394)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set is an ArcView shapefile set that contains locations of sampled coral reef fish species at the National Marine Sanctuary along the Florida Keys. The...

  7. Florida Reef Fish Visual Census 1987 Species Site Matrix (NODC Accession 0001394)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set is an ArcView shapefile set that contains locations of sampled coral reef fish species at the National Marine Sanctuary along the Florida Keys. The...

  8. Florida Reef Fish Visual Census 1979 Species Site Matrix (NODC Accession 0001394)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set is an ArcView shapefile set that contains locations of sampled coral reef fish species at the National Marine Sanctuary along the Florida Keys. The...

  9. Checklist of non-indigenous fish species of the River Danube

    Directory of Open Access Journals (Sweden)

    Zorić Katarina

    2014-01-01

    Full Text Available Twenty non-indigenous fish species were recorded in the Danube River. The manner of their introduction, vectors, pathways, as well as invasive status are discussed. The major modes of introduction and translocation were found to be aquaculture and fish stocking. The main environmental consequences of the spread of alien fish are related to changes in the structure and functioning of the fish community and to the introduction of non-indigenous parasites. [Projekat Ministarstva nauke Republike Srbije, br. ON 173025, TR 37009 and III 43002 and European Commission 6th Framework Program: Integrated Project ALARM (contract GOCE-CT-2003-506675

  10. The Bifurcation and Control of a Single-Species Fish Population Logistic Model with the Invasion of Alien Species

    OpenAIRE

    Zhang, Yi; Zhang, Qiaoling; Li, Jinghao; Zhang, Qingling

    2014-01-01

    The objective of this paper is to study systematically the bifurcation and control of a single-species fish population logistic model with the invasion of alien species based on the theory of singular system and bifurcation. It regards Spartina anglica as an invasive species, which invades the fisheries and aquaculture. Firstly, the stabilities of equilibria in this model are discussed. Moreover, the sufficient conditions for existence of the trans-critical bifurcation and the singularity ind...

  11. Reef fishes in biodiversity hotspots are at greatest risk from loss of coral species.

    Directory of Open Access Journals (Sweden)

    Sally J Holbrook

    Full Text Available Coral reef ecosystems are under a variety of threats from global change and anthropogenic disturbances that are reducing the number and type of coral species on reefs. Coral reefs support upwards of one third of all marine species of fish, so the loss of coral habitat may have substantial consequences to local fish diversity. We posit that the effects of habitat degradation will be most severe in coral regions with highest biodiversity of fishes due to greater specialization by fishes for particular coral habitats. Our novel approach to this important but untested hypothesis was to conduct the same field experiment at three geographic locations across the Indo-Pacific biodiversity gradient (Papua New Guinea; Great Barrier Reef, Australia; French Polynesia. Specifically, we experimentally explored whether the response of local fish communities to identical changes in diversity of habitat-providing corals was independent of the size of the regional species pool of fishes. We found that the proportional reduction (sensitivity in fish biodiversity to loss of coral diversity was greater for regions with larger background species pools, reflecting variation in the degree of habitat specialization of fishes across the Indo-Pacific diversity gradient. This result implies that habitat-associated fish in diversity hotspots are at greater risk of local extinction to a given loss of habitat diversity compared to regions with lower species richness. This mechanism, related to the positive relationship between habitat specialization and regional biodiversity, and the elevated extinction risk this poses for biodiversity hotspots, may apply to species in other types of ecosystems.

  12. Reef fishes in biodiversity hotspots are at greatest risk from loss of coral species.

    Science.gov (United States)

    Holbrook, Sally J; Schmitt, Russell J; Messmer, Vanessa; Brooks, Andrew J; Srinivasan, Maya; Munday, Philip L; Jones, Geoffrey P

    2015-01-01

    Coral reef ecosystems are under a variety of threats from global change and anthropogenic disturbances that are reducing the number and type of coral species on reefs. Coral reefs support upwards of one third of all marine species of fish, so the loss of coral habitat may have substantial consequences to local fish diversity. We posit that the effects of habitat degradation will be most severe in coral regions with highest biodiversity of fishes due to greater specialization by fishes for particular coral habitats. Our novel approach to this important but untested hypothesis was to conduct the same field experiment at three geographic locations across the Indo-Pacific biodiversity gradient (Papua New Guinea; Great Barrier Reef, Australia; French Polynesia). Specifically, we experimentally explored whether the response of local fish communities to identical changes in diversity of habitat-providing corals was independent of the size of the regional species pool of fishes. We found that the proportional reduction (sensitivity) in fish biodiversity to loss of coral diversity was greater for regions with larger background species pools, reflecting variation in the degree of habitat specialization of fishes across the Indo-Pacific diversity gradient. This result implies that habitat-associated fish in diversity hotspots are at greater risk of local extinction to a given loss of habitat diversity compared to regions with lower species richness. This mechanism, related to the positive relationship between habitat specialization and regional biodiversity, and the elevated extinction risk this poses for biodiversity hotspots, may apply to species in other types of ecosystems.

  13. Foraging ecology of least terns and piping plovers nesting on Central Platte River sandpits and sandbars

    Science.gov (United States)

    Sherfy, Mark H.; Anteau, Michael J.; Shaffer, Terry L.; Sovada, Marsha A.; Stucker, Jennifer H.

    2012-01-01

    Federally listed least terns (Sternula antillarum) and piping plovers (Charadrius melodus) nest on riverine sandbars on many major midcontinent river systems. On the Central Platte River, availability of sandbar habitat is limited, and both species nest on excavated sandpits in the river's floodplain. However, the extent to which sandpit-nesting birds use riverine habitats for foraging is unknown. We evaluated use of foraging habitats by least terns and piping plovers by collecting data on movements, behavior, foraging habitat, and productivity. We radiomarked 16 piping plovers and 23 least terns in 2009-2010 and monitored their movements using a network of fixed telemetry dataloggers. Piping plovers were detected primarily by the datalogger located in their nesting sandpit, whereas least terns were more frequently detected on dataloggers outside of the nesting sandpit. Telemetry data and behavioral observations showed that least terns tended to concentrate at the Kearney Canal Diversion Gates, where forage fish were apparently readily available. Fish sampling data suggested that forage fish were more abundant in riverine than in sandpit habitats, and behavioral observations showed that least terns foraged more frequently in riverine than in sandpit habitats. Piping plovers tended to forage in wet substrates along sandpit shorelines, but also used dry substrates and sandpit interior habitats. The greater mobility of least terns makes a wider range of potential foraging habitats available during brood rearing, making them able to exploit concentrations of fish outside the nesting colony. Thus, our data suggest that different spatial scales should be considered in managing nesting and foraging habitat complexes for piping plovers and least terns.

  14. Important variations in parvalbumin content in common fish species: a factor possibly contributing to variable allergenicity.

    Science.gov (United States)

    Kuehn, A; Scheuermann, T; Hilger, C; Hentges, F

    2010-01-01

    Although 95% of fish-allergic patients are sensitized to the major fish allergen parvalbumin, clinical reactions to different fish species vary considerably in symptoms, intensity and frequency in allergic subjects. This study aimed at the quantification of parvalbumin levels in salmon, trout, cod, carp, mackerel, herring, redfish and tuna. Fish muscle extracts were separated by SDS-PAGE and parvalbumin content was estimated by densitometric band quantification. Individual antisera were raised in BALB/c mice against parvalbumins purified from seven fish species. Parvalbumin content was quantified in fish (raw/processed) and skin prick test (SPT) solutions by ELISA using the corresponding anti-serum for detection and the purified parvalbumins as standards. Using SDS-PAGE scanning, parvalbumin contents were 2 mg for cod, carp, redfish and herring. Using ELISA, parvalbumin content ranged from 2.5 mg per gram raw muscle for carp, herring and redfish. The parvalbumin content of processed samples (cooked/commercial) was 20-60% lower. Allergen content in SPT samples ranged from 20 to 70 μg parvalbumin/ml of extract. No parvalbumin was found in tuna SPT solution. The parvalbumin content of most commonly consumed fish species varies considerably. Differences range from severalfold to one hundredfold. This has to be taken into account when designing food challenge tests and advising fish-allergic patients. Copyright © 2010 S. Karger AG, Basel.

  15. Detection of Listeria species in Gamma irradiated Fishes during Storage periods

    International Nuclear Information System (INIS)

    Mohamed, W.S.

    2011-01-01

    This investigation was carried out to detect the post irradiation recovery and growth of Listeria species encountered in frozen whole Tilapia fishes ,Tilapia fillet and frozen Hamour fillets fishes (-18 degree C) irradiated at 1, 2, 2.5 and 3 kGy. The pathogen was eliminated at a dose of 2.5 kGy of gamma radiation. The presence of the microorganism was monitored for sex months on appropriate selective media. The ability of recovery of the organism from irradiation damage was not influenced by the kind of fish. No increased counts of the organism in irradiated fishes at 2.5 kGy of gamma radiation was noticed during 6 months of freezing storage at -18 degree C. This study also aimed to evaluate the effect of different enrichment procedures on the detection of Listeria species in fishes

  16. Characterization of chitin extracted from fish scales of marine fish species purchased from local markets in North Sulawesi, Indonesia

    Science.gov (United States)

    Rumengan, I. F. M.; Suptijah, P.; Wullur, S.; Talumepa, A.

    2017-10-01

    Chitin is a biodegradable biopolymer with a variety of commercial applications, including in the food food-supplement industries as a marine-derived nutraceutical. The purpose of this study was to characterize the molecular structure of chitin extracted from fish scales of important marine fish purchased from local markets in North Sulawesi. Chitin compound material was obtained from a specific fish scale, and then sequentially carrying out a boiling treatment to separate it from a complex with collagen. From the scales of two fish species, parrotfish (Chlorurus sordidus) and red snapper (Lutjanus argentimaculatus), the rendemen of chitin obtained were 45 % and 33%, respectively. Structural characteristics of the chitin were discussed by FTIR (Fourier Transform Infrared) analysis data. FTIR analysis was done using infrared spectroscopy, which is the resulting spectrum represents the molecular absorption and transmission, creating a molecular fingerprint of the sample. The molecular structure of chitin, C18H26N2O10, where the hydroxyl group on the second carbon replaced by acetyl amide, was shown by the infrared spectra. In the infrared spectra, chitin from parrot fish scales indicated the amide band at 1627.13 cm-1, and chitin from red snapper fish scales the amide band at 1648.09 cm-1 which are a typical one for marine chitin. The hydroxyl and amino bands at the ranged spectra up to 3500 cm-1. The yields of chitin isolated from fish scale were relatively huge. Some treatments are necessary to confirm the molecular conformation and deacetylation behavior. All products from the extraction of fish scales could be more accessible for structural modifications to develop biocompatible materials for pharmaceutical purposes.

  17. Monitoring of fish species in the Lamone river: distribution and morphometric measures of the populations

    Directory of Open Access Journals (Sweden)

    Riccardo Bozzi

    2010-01-01

    Full Text Available Fish samplings were carried out monthly from spring to autumn during 2008, on the Lamone river and the Campigno stream by an electrofishing, in order to verify the presence of fish populations and the most common species represented. Barb, Barbus plebejus, Blageon, Leuciscus muticellus, Chub, Leuciscus cephalus, South European Nase, Chondrostoma genei were identified. A small population of Brown trout, Salmo trutta fario was also recognized. Barb is the most represented species in all the sites. The samplings highlight that Lamone river presented conditions suitable to fully guarantee the life of the fish populations.

  18. Farming a new economically viable fish species: Kisinja (Barbus altianalis)

    OpenAIRE

    Aruho, C.; Ondhoro, C.C.

    2010-01-01

    Kisinja (Barbus altianalis)is an indigenous omnivorous fish, of high economic value in Uganda. It was widely distributed in most lakes and rivers in the country but its stocks were depleted due to overfishing and degradation of its natural habitat. 1t can grow up to a maximum length of 120m and a weight of 15kg in the wild and grows faster, attains larger size than commonly farmed fishes in Uganda, including the Nile tilapia, the African catfish, and mirror carp. Kisinja is a highly valuable ...

  19. DNA barcoding for species assignment: the case of Mediterranean marine fishes.

    Directory of Open Access Journals (Sweden)

    Monica Landi

    Full Text Available DNA barcoding enhances the prospects for species-level identifications globally using a standardized and authenticated DNA-based approach. Reference libraries comprising validated DNA barcodes (COI constitute robust datasets for testing query sequences, providing considerable utility to identify marine fish and other organisms. Here we test the feasibility of using DNA barcoding to assign species to tissue samples from fish collected in the central Mediterranean Sea, a major contributor to the European marine ichthyofaunal diversity.A dataset of 1278 DNA barcodes, representing 218 marine fish species, was used to test the utility of DNA barcodes to assign species from query sequences. We tested query sequences against 1 a reference library of ranked DNA barcodes from the neighbouring North East Atlantic, and 2 the public databases BOLD and GenBank. In the first case, a reference library comprising DNA barcodes with reliability grades for 146 fish species was used as diagnostic dataset to screen 486 query DNA sequences from fish specimens collected in the central basin of the Mediterranean Sea. Of all query sequences suitable for comparisons 98% were unambiguously confirmed through complete match with reference DNA barcodes. In the second case, it was possible to assign species to 83% (BOLD-IDS and 72% (GenBank of the sequences from the Mediterranean. Relatively high intraspecific genetic distances were found in 7 species (2.2%-18.74%, most of them of high commercial relevance, suggesting possible cryptic species.We emphasize the discriminatory power of COI barcodes and their application to cases requiring species level resolution starting from query sequences. Results highlight the value of public reference libraries of reliability grade-annotated DNA barcodes, to identify species from different geographical origins. The ability to assign species with high precision from DNA samples of disparate quality and origin has major utility in several

  20. Nitrogen and carbohydrate fractions in exclusive Tifton 85 and in pasture oversown with annual winter forage species - 10.4025/actascianimsci.v34i1.11428

    Directory of Open Access Journals (Sweden)

    Ana Claudia Ruggieri

    2011-11-01

    Full Text Available The experiment was undertaken at the Faculty of Agrarian and Veterinary Sciences (FCAV Jaboticabal, São Paulo State, Brazil, during winter-spring-summer of 2001-2002, to determine the fractionation of nitrogen and carbohydrates in Tifton 85 (Cynodon dactylon Vanderyst x Cynodon nlemfuensis (L. Pers, exclusively or oversown with winter annual forage species. Treatments comprised bristle oat (Avena strigosa Schreb, yellow oat (Avena byzantina C. Koch, triticale (X Triticosecale Wittmack, bristle oat + yellow oat, bristle oat + triticale, yellow oat + triticale, bristle oat + yellow oat + triticale seeded in Tifton 85 and sole crop (control. Experimental design was composed of completely randomized blocks with three replications. Fodder was cut 20 cm high (presence of winter forage and 10 cm high (Tifton 85 pasture. Crude protein, total carbohydrate and the fractions of nitrogen compounds and carbohydrates were determined. Decrease was reported in the levels of chemical compounds in winter forage species and in Tifton 85 during the evaluation periods. The content of nitrogen compounds and carbohydrates varied widely during the evaluation period according to the morphological characteristics of grass species and botanical composition of pastures.

  1. Heavy metal contamination and health risk assessment in three commercial fish species in the Persian Gulf.

    Science.gov (United States)

    Keshavarzi, Behnam; Hassanaghaei, Mina; Moore, Farid; Rastegari Mehr, Meisam; Soltanian, Siyavash; Lahijanzadeh, Ahmad Reza; Sorooshian, Armin

    2018-04-01

    Five heavy metals/metalloids and related potential health risks were investigated in three commercially important fish species (Anodontostoma chacunda, Belangerii, and Cynoglossurs arel) in Musa Estuary and Mahshahr Harbour of the Persian Gulf. A total of 116 fish samples were collected, and their liver and muscle organs were separately analyzed using ICP-MS. Results revealed that studied metals concentrations (with some exceptions) varied among sampling stations, fish species and their organs. Human health risk is evaluated using different indices. The results indicated that arsenic and mercury are the most hazardous elements. Estimated daily intake (EDI) for the metals exceeded the provisional tolerable daily intake (PTDI) for all studied fish species. Also, target risk (TR) of arsenic indicated that consumption over a long period of time may result in a carcinogenic effect. The results are expected to create awareness among the public on the safety of consuming food products grown in particular areas. Copyright © 2018. Published by Elsevier Ltd.

  2. Trophic levels of fish species of commercial importance in the Colombian Caribbean

    Directory of Open Access Journals (Sweden)

    Camilo B García

    2011-09-01

    Full Text Available Ecological studies on commercial important fish species are of great value to support resource management issues. This study calculated trophic levels of those Colombian Caribbean fish species whose diet has been locally described. Usable diet data of 119 species resulted in 164 trophic level estimates. An ordinary regression model relating trophic level and fish size was formulated. The regression slope was positive and significantly different from zero (p<0.05 suggesting a scaling of trophic level with fish size. Both the list of trophic levels and the regression model should be of help in the formulation of trophic indicators and models of neotropical ecosystems. Rev. Biol. Trop. 59 (3: 1195-1203. Epub 2011 September 01.

  3. Distribution of Po-210 in two species of predatory marine fish from the Brazilian coast

    International Nuclear Information System (INIS)

    Mársico, E.T.; Ferreira, M.S.; São Clemente, S.C.; Gouvea, R.C.S.; Jesus, E.F.O.; Conti, C.C.; Conte Junior, C.A.; Kelecom, A.G.A.C.

    2014-01-01

    Polonium-210 ( 210 Po) concentration was quantified in the muscle tissue and organs of two predatory marine fishes (Genypterus brasiliensis and Cynoscion microlepidotus) from Cabo Frio, Rio de Janeiro, Brazil. The species C. microlepidotus, a benthic carnivore, registered higher 210 Po in its tissue. The organs associated with digestion displayed the maximum radionuclide compared with other organs. The average activity was 2 mBq kg −1 for G. brasiliensis and it was 6 mBq kg −1 for C. microlepidotus. The activity concentrations varied significantly between the species and among organs. -- Highlights: • We analyzed the distribution of 210 Po in two species of predator marine fish. • 210 Po tends to accumulate in some organs, which make this radionuclide radiotoxic. • The consumption of small quantities of fish can represent high potential of 210 Po exposure. • Data about 210 Po bioaccumulation in tropical predator marine fish are limited

  4. length-weight relationhip of freshwater wild fish species

    African Journals Online (AJOL)

    Dr Naeem

    2012-06-21

    Jun 21, 2012 ... Length-weight (LWR) and length-length relationships (LLR) were determined for a freshwater catfish ... Key words: Mystus bleekeri, length-weight relationship, length-length relationship, predictive equations. INTRODUCTION. Mystus bleekeri (freshwater catfish Day, 1877), locally ..... fish farmers, Aquacult.

  5. Using a Popular Pet Fish Species to Study Territorial Behaviour

    Science.gov (United States)

    Abante, Maria E.

    2005-01-01

    The colourful, vigorous territorial display behaviour of the Siamese fighting fish, "Betta splendens", has great appeal for both pet enthusiasts and animal behaviourists. Their beauty, longevity, easy maintenance and rearing make them a popular pet and an ideal science laboratory specimen. This investigation utilises "B. splendens" to test for the…

  6. Mercury and lead concentrations in six cartilaginous fish species ...

    African Journals Online (AJOL)

    Mercury and lead concentrations in cartilaginous fishes from Lagos Lagoon and coastal waters of South-West Nigeria were investigated between May and August 2013. There are obvious discharges of toxic heavy metal substances into these waters and which can get to man by bioaccumulation and biomagnifications in ...

  7. Use of fish parasite species richness indices in analyzing anthropogenically impacted coastal marine ecosystems

    Science.gov (United States)

    Dzikowski, R.; Paperna, I.; Diamant, A.

    2003-10-01

    The diversity of fish parasite life history strategies makes these species sensitive bioindicators of aquatic ecosystem health. While monoxenous (single-host) species may persist in highly perturbed, extreme environments, this is not necessarily true for heteroxenous (multiple-host) species. As many parasites possess complex life cycles and are transmitted through a chain of host species, their dependency on the latter to complete their life cycles renders them sensitive to perturbed environments. In the present study, parasite communities of grey mullet Liza aurata and Liza ramada (Mugilidae) were investigated at two Mediterranean coastal sites in northern Israel: the highly polluted Kishon Harbor (KH) and the relatively unspoiled reference site, Ma'agan Michael (MM). Both are estuarine sites in which grey mullet are one of the most common fish species. The results indicate that fish at the polluted site had significantly less trematode metacercariae than fish at the reference site. Heteroxenous gut helminths were completely absent at the polluted sampling site. Consequently, KH fish displayed lower mean parasite species richness. At the same time, KH fish mean monoxenous parasite richness was higher, although the prevalence of different monoxenous taxa was variable. Copepods had an increased prevalence while monogenean prevalence was significantly reduced at the polluted site. This variability may be attributed to the differential susceptibility of the parasites to the toxicity of different pollutants, their concentration, the exposure time and possible synergistic effects. In this study, we used the cumulative species curve model that extrapolates "true" species richness of a given habitat as a function of increasing sample size. We considered the heteroxenous and monoxenous species separately for each site, and comparison of curves yielded significant results. It is proposed to employ this approach, originally developed for estimating the "true" parasite

  8. Fish and phytoplankton exhibit contrasting temporal species abundance patterns in a dynamic north temperate lake.

    Directory of Open Access Journals (Sweden)

    Gretchen J A Hansen

    Full Text Available Temporal patterns of species abundance, although less well-studied than spatial patterns, provide valuable insight to the processes governing community assembly. We compared temporal abundance distributions of two communities, phytoplankton and fish, in a north temperate lake. We used both 17 years of observed relative abundance data as well as resampled data from Monte Carlo simulations to account for the possible effects of non-detection of rare species. Similar to what has been found in other communities, phytoplankton and fish species that appeared more frequently were generally more abundant than rare species. However, neither community exhibited two distinct groups of "core" (common occurrence and high abundance and "occasional" (rare occurrence and low abundance species. Both observed and resampled data show that the phytoplankton community was dominated by occasional species appearing in only one year that exhibited large variation in their abundances, while the fish community was dominated by core species occurring in all 17 years at high abundances. We hypothesize that the life-history traits that enable phytoplankton to persist in highly dynamic environments may result in communities dominated by occasional species capable of reaching high abundances when conditions allow. Conversely, longer turnover times and broad environmental tolerances of fish may result in communities dominated by core species structured primarily by competitive interactions.

  9. Fish and Phytoplankton Exhibit Contrasting Temporal Species Abundance Patterns in a Dynamic North Temperate Lake

    Science.gov (United States)

    Hansen, Gretchen J. A.; Carey, Cayelan C.

    2015-01-01

    Temporal patterns of species abundance, although less well-studied than spatial patterns, provide valuable insight to the processes governing community assembly. We compared temporal abundance distributions of two communities, phytoplankton and fish, in a north temperate lake. We used both 17 years of observed relative abundance data as well as resampled data from Monte Carlo simulations to account for the possible effects of non-detection of rare species. Similar to what has been found in other communities, phytoplankton and fish species that appeared more frequently were generally more abundant than rare species. However, neither community exhibited two distinct groups of “core” (common occurrence and high abundance) and “occasional” (rare occurrence and low abundance) species. Both observed and resampled data show that the phytoplankton community was dominated by occasional species appearing in only one year that exhibited large variation in their abundances, while the fish community was dominated by core species occurring in all 17 years at high abundances. We hypothesize that the life-history traits that enable phytoplankton to persist in highly dynamic environments may result in communities dominated by occasional species capable of reaching high abundances when conditions allow. Conversely, longer turnover times and broad environmental tolerances of fish may result in communities dominated by core species structured primarily by competitive interactions. PMID:25651399

  10. Distribution Species Composition And Size Of Flying Fish Exocoetidae In The Ceram Sea

    Directory of Open Access Journals (Sweden)

    Friesland Tuapetel

    2015-03-01

    Full Text Available Abstract Ceram Sea is new resources area of catching flying fish. The purpose of study is to determine the species composition size and distribution of flying fish caught by drifting baits. Flying fish data collection was conducted in June until October 2013 in three locations i.e Kaimana East Ceram and Fak-Fak. There are three flying fish species collected namely Hirundichthys oxycephalus Torani Cypselurus poecilopterus Banggulung and Chellopogon abeia yellow wing. The results was showed that in Fak-Fak and Kaimana there are two types of fly fishing that H. oxycephalus andC. poecilopterus whereas in East Ceram found three types including H. oxycephalus C. poecilopterus and C. abeia. The dominant type of flying fish in three locations is H. oxycephalus. Flying fish has a variety size range of body size from 195.6 to 243.6 mm in Kaimana East Ceram range from 206.3 to 284.3 mm while Fak-Fak range from 187.1 to 243.1 mm. The result is expected to be a reference literature as basic data for the management and sustainable utilization of flyling fish in Ceram sea.

  11. Prevalence of salmonella species in fishes and its control using irradiation

    International Nuclear Information System (INIS)

    Mohamed, W. S.

    2010-01-01

    The prevalence of Salmonella species infecting frozen Tilapia fish fillets and whole fishes was determined, during the summer seasons of years 2006 and 2007.Elimination of Salmonella species in Tilapia fishes with different doses of γ-rays was investigated. Doses of 1, 2, 3, 3.5, 5, 4 and 5 kGy were used to find out the least dose that will be sufficient to eliminate the pathogen from the examined samples. Two hundred fish fillet samples and 200 whole fishes were subjected for bacteriological examination for the incidence of Salmonella infection. Out of them 19 fillets and 8 whole fishes were infected with the pathogen in a percentage of 9.5 % and 4 % respectively. The serological determination detected the infection with Salmonella typhimurium in all the affected samples. A dose of 3.5 kGy γ-rays was determined to be the least appropriate dose for elimination of Salmonella typhimurium from Tilapia fishes. The best appearance characteristics were obtained at 3.5 kGy of γ-irradiation. There was a gradual decrease in the count of the micro-organism as the dose of irradiation increased (linear regression). So a dose of 3.5 kGy of γ-irradiation is recommended for healthy, good looking and economic fishes for public health benefits.

  12. Shearwater foraging in the Southern Ocean: the roles of prey availability and winds.

    Directory of Open Access Journals (Sweden)

    Ben Raymond

    Full Text Available BACKGROUND: Sooty (Puffinus griseus and short-tailed (P. tenuirostris shearwaters are abundant seabirds that range widely across global oceans. Understanding the foraging ecology of these species in the Southern Ocean is important for monitoring and ecosystem conservation and management. METHODOLOGY/PRINCIPAL FINDINGS: Tracking data from sooty and short-tailed shearwaters from three regions of New Zealand and Australia were combined with at-sea observations of shearwaters in the Southern Ocean, physical oceanography, near-surface copepod distributions, pelagic trawl data, and synoptic near-surface winds. Shearwaters from all three regions foraged in the Polar Front zone, and showed particular overlap in the region around 140 degrees E. Short-tailed shearwaters from South Australia also foraged in Antarctic waters south of the Polar Front. The spatial distribution of shearwater foraging effort in the Polar Front zone was matched by patterns in large-scale upwelling, primary production, and abundances of copepods and myctophid fish. Oceanic winds were found to be broad determinants of foraging distribution, and of the flight paths taken by the birds on long foraging trips to Antarctic waters. CONCLUSIONS/SIGNIFICANCE: The shearwaters displayed foraging site fidelity and overlap of foraging habitat between species and populations that may enhance their utility as indicators of Southern Ocean ecosystems. The results highlight the importance of upwellings due to interactions of the Antarctic Circumpolar Current with large-scale bottom topography, and the corresponding localised increases in the productivity of the Polar Front ecosystem.

  13. Species richness and distribution of chondrichthyan fishes in the Arctic Ocean and adjacent seas

    DEFF Research Database (Denmark)

    Lynghammar, A.; Christiansen, J. S.; Mecklenburg, C. W.

    2013-01-01

    The sea ice cover decreases and human activity increases in Arctic waters. Fisheries and bycatch issues, shipping and petroleum exploitation (pollution issues) make it imperative to establish biological baselines for the marine fishes inhabiting the Arctic Ocean and adjacent seas (AOAS). Species...... richness, zoogeographic affiliations and Red List statuses among chondrichthyan fishes (Chondrichthyes) were examined across 16 AOAS regions as a first step towards credible conservation actions. Published literature and museum vouchers were consulted for presence/absence data. Although many regions...... are poorly sampled, 49 chondrichthyan species have been reported from the AOAS. Skates and rays are the most species-rich taxon, represented by 27 species in family Rajidae and one species in family Dasyatidae. The sharks comprise 20 species in 13 families and the chimaeras one species in family Chimaeridae...

  14. 76 FR 71315 - Endangered and Threatened Species; Take of Anadromous Fish

    Science.gov (United States)

    2011-11-17

    ... species and population level abundance and timing, (2) determine growth rate, size, food habits, and... benefit listed species by helping managers at the power facility tailor their operations to cause the... research would benefit the fish by helping managers at the power facility determine the best way to conduct...

  15. Temporal variations in the food habits of some fish species in Lake ...

    African Journals Online (AJOL)

    Stomach contents of the 12 most abundant fish species in Lake Nokoué, Benin, collected between 2003 and 2005, were analysed for temporal variations in their diet. Several species showed seasonal shifts in their diets based on benthic prey abundance and biomass variation, which are influenced by physico-chemical ...

  16. 76 FR 78242 - Endangered and Threatened Species; Take of Anadromous Fish

    Science.gov (United States)

    2011-12-16

    ... DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration RIN 0648-XA866 Endangered and Threatened Species; Take of Anadromous Fish AGENCY: National Marine Fisheries Service (NMFS... Endangered Species Act (ESA) and to help guide management and conservation efforts. The application may be...

  17. 75 FR 25205 - Endangered and Threatened Species; Take of Anadromous Fish

    Science.gov (United States)

    2010-05-07

    ... DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration RIN 0648-XW33 Endangered and Threatened Species; Take of Anadromous Fish AGENCY: NOAA's National Marine Fisheries Service (NMFS... permit. Dated: May 4, 2010. Therese Conant, Acting Chief, Endangered Species Division, Office of...

  18. Occurrence of three leech species (Annelida: Hirudinida) on fishes in the Kentucky River

    Science.gov (United States)

    Leeches were collected from six fish species distributed among four of ten sites sampled. The leech species observed were Myzobdella reducta (Meyer, 1940) and Myzobdella lugubris Leidy, 1851 of the family Piscicolidae and Placobdella pediculata Hemingway, 1908 of the family Gloss...

  19. Total mercury of selected fish species from Laguna de Bay

    International Nuclear Information System (INIS)

    Relon, Milagros Lontoc

    1996-01-01

    Dalag Ophicephalus striatus Block, kanduli Arius thalassinus Ruppell, bia Amblygobius phalaena Cuvier et Valenciennes and tilapia Tilapia nilotica Linnnaeus collected from Laguna de Bay between Taguig and Binangonan area in August 1989 to July 1990 were analyzed for total mercury by atomic absorption spectrometry. The highest metal concentration in soft muscle tissue was observed in Dalag followed by kanduli, less in bia and least in tilapia with mean values of 0.021, 0.020, 0.013, and 0.008 ug/g, respectively. Analysis using two-way ANOVA showed a significant difference in the mean total mercury in ug/g in the difference fish samples, among the different months and the interaction between these two variables. Mean total mercury of the four fish samples were significantly higher in April than in October. The results show that the levels of total mercury in the fish samples are below the World Health Organization maximum tolerable consumption of mercury in food of 300 ug or 0.03 mg of total mercury per week. (author)

  20. Application of instrumental neutron activation analysis for the analysis of six fish species

    Energy Technology Data Exchange (ETDEWEB)

    Moon, J. H.; Oh, M.; Kim, S. H.; Chung, Y. S. [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2014-05-15

    According to the meeting report of the Food and Agriculture Organization (FAO), annual food fish supply per capita has increased from an average of 9.9 kg in the 1960s to 18.4 kg in 2009, and fish consumption was lowest in Africans (9.1 kg per capita), while Asians consumed 20.7 kg per capita. From the viewpoint of food safety, fish accumulates environmental contaminants and an analysis of hazardous chemical species including toxic heavy metals is important for human health. The aims of this study were to determine the inorganic elemental content in six popular fish species of Korea by NAA and to aid in the evaluation of dietary intake levels in terms of toxic and essential elements. An INAA for the six fish species that are popular in Korea was performed, and sixteen elemental contents were determined. Based on these analytical data and survey data in 2010, intake levels for 3 toxic heavy metals by each fish species are evaluated for Koreans. These dietary intake values for heavy metals can be used for an assessment of human health risk.

  1. Do low-mercury terrestrial resources subsidize low-mercury growth of stream fish? Differences between species along a productivity gradient.

    Directory of Open Access Journals (Sweden)

    Darren M Ward

    Full Text Available Low productivity in aquatic ecosystems is associated with reduced individual growth of fish and increased concentrations of methylmercury (MeHg in fish and their prey. However, many stream-dwelling fish species can use terrestrially-derived food resources, potentially subsidizing growth at low-productivity sites, and, because terrestrial resources have lower MeHg concentrations than aquatic resources, preventing an increase in diet-borne MeHg accumulation. We used a large-scale field study to evaluate relationships among terrestrial subsidy use, growth, and MeHg concentrations in two stream-dwelling fish species across an in-stream productivity gradient. We sampled young-of-the-year brook trout (Salvelinus fontinalis and Atlantic salmon (Salmo salar, potential competitors with similar foraging habits, from 20 study sites in streams in New Hampshire and Massachusetts that encompassed a wide range of aquatic prey biomass. Stable isotope analysis showed that brook trout used more terrestrial resources than Atlantic salmon. Over their first growing season, Atlantic salmon tended to grow larger than brook trout at sites with high aquatic prey biomass, but brook grew two-fold larger than Atlantic salmon at sites with low aquatic prey biomass. The MeHg concentrations of brook trout and Atlantic salmon were similar at sites with high aquatic prey biomass and the MeHg concentrations of both species increased at sites with low prey biomass and high MeHg in aquatic prey. However, brook trout had three-fold lower MeHg concentrations than Atlantic salmon at low-productivity, high-MeHg sites. These results suggest that differential use of terrestrial resource subsidies reversed the growth asymmetry between potential competitors across a productivity gradient and, for one species, moderated the effect of low in-stream productivity on MeHg accumulation.

  2. Bioaccumulation of PCB Contaminants in Five Fish Species in Utah Lake as Affected by Carp Removal

    Science.gov (United States)

    Sanjinez-Guzmán, V. A.; Cadet, E. L.; Crandall, T.; Chamberlain, T.; Rakotoarisaona, H.; Morris, P.

    2017-12-01

    State reports published by the Utah Department of Health (2005) and the Utah Department of Water Quality (2008) determined that there were elevated levels of PCBs (Polychlorinated biphenyls) that exceeded the EPA's cancer (0.02 𝑚𝑔 𝑘𝑔-1) and non-cancer screening levels (0.08 𝑚𝑔 𝑘𝑔-1) in two fish species from Utah Lake, the Common Carp (Cyprinus carpio) and the Channel Catfish (Ictalurus punctatus). Fish consumption advisories were issued for both of these fish species due to their health effects of PCBs. The Common Carp is a non-native predatory species that comprise 90% of the biomass in Utah Lake. As of September 2009, an extensive carp removal program was instituted by the Department of Natural Resources and began the removal of 75% of the carp population. The purpose of this study is to assess the impact of carp removal on PCB levels in five sport fish species consumed by Utah citizens. The fish being analyzed are the Common Carp (Cyprinus carpio), Channel Catfish (Ictalurus punctatus), Black Bullhead (Ameiurus melas), Walleye (Sander vitreus), and White Bass (Morone chrysops). One-hundred twenty (120) fish were collected from Utah Lake and subcategorized by their gender, tissue type (fillet and offal), weight, and size: small (under 33 cm), medium (33 cm - 43 cm), and large (greater than 43 cm). This was done in order to determine the variation of contaminant levels in each subcategory. PCB analysis was performed by Utility Testing Laboratory in Salt Lake City, Utah. Results show there has been a significant increase in PCB levels in all fish species in comparison with the state reports (2008). All fish species have exceeded the EPA cancer screening level, except for the fillet tissue of the White Bass species. In Common Carp fillet, and offal decreased concentrations of 11.80% and 23.72%, respectively. In Channel catfish: the PCB levels in the fillet increase by 87.93%, however, the offal levels

  3. Forage preferences in two species of prairie dog (Cynomys parvidens and Cynomus ludovicianus): Implications for hibernation and facultative heterothermy

    Science.gov (United States)

    Lehmer, E.M.; Biggins, D.E.; Antolin, M.F.

    2006-01-01

    Several laboratory studies have shown that the ingestion of dietary linoleic (18:2 ??6) acid before winter can promote deep and continuous torpor, whereas excess consumption of ??-linolenic acid (18:3 ??3) can interfere with an animal's ability to reach and maintain low body temperatures during torpor. As mammalian heterotherms obtain linoleic and ??-linolenic acid strictly from the diet, diet selection has been proposed as a mechanism that allows hibernators to ingest levels of linoleic and ??-linolenic acid that promote favorable torpor patterns. Here diet, dietary nutrient content and patterns of forage preference of a representative hibernator, the Utah prairie dog Cynomys parvidens, and a facultative heterotherm, the black-tailed prairie dog Cynomys ludovicianus, were examined under natural field conditions. Diets of black-tailed (BTPD) and Utah prairie dogs (UTPD) differed across seasons (BTPD F26,108=9.59, Pplant species relative to their abundance on colonies in any season. Black-tailed prairie dogs did not consume or avoid consumption of plant species based on levels of total lipids, linoleic acid, ??-linolenic acid or nitrogen. Considering only the plants consumed, black-tailed prairie dogs appeared to prefer plants with low levels of ??-linolenic acid (F1,19=5.81, P=0.03), but there were no detectable relationships between preference and other nutrients. Utah prairie dogs consumed plants higher in ??-linolenic acid (t=1.98, P=0.05) and avoided plants high in linoleic acid (t=-2.02, P=0.04), but consumption-avoidance decisions did not appear to be related to nitrogen or total lipids. Of the plants consumed, Utah prairie dogs again preferred plants high in ??-linolenic acid (F1,17=4.62, P=0.05). Levels of linoleic and ??-linolenic acid were positively correlated in plants consumed by prairie dogs (BTPD Pearson r=0.66, P<0.01; UTPD Pearson r=0.79, P<0.01), reducing the opportunity for independent selection of either lipid. ?? 2006 The Authors.

  4. Phytoplankton IF-FISH: Species-specific labeling of cellular proteins by immunofluorescence (IF) with simultaneous species identification by fluorescence immunohybridization (FISH).

    Science.gov (United States)

    Meek, Megan E; Van Dolah, Frances M

    2016-05-01

    Phytoplankton rarely occur as unialgal populations. Therefore, to study species-specific protein expression, indicative of physiological status in natural populations, methods are needed that will both assay for a protein of interest and identify the species expressing it. Here we describe a protocol for IF-FISH, a dual labeling procedure using immunofluorescence (IF) labeling of a protein of interest followed by fluorescence in situ hybridization (FISH) to identify the species expressing that protein. The protocol was developed to monitor expression of the cell cycle marker proliferating cell nuclear antigen (PCNA) in the red tide dinoflagellate, Karenia brevis, using a large subunit (LSU) rRNA probe to identify K. brevis in a mixed population of morphologically similar Karenia species. We present this protocol as proof of concept that IF-FISH can be successfully applied to phytoplankton cells. This method is widely applicable for the analysis of single-cell protein expression of any protein of interest within phytoplankton communities. Copyright © 2016 Elsevier B.V. All rights reserved.

  5. Study on trace elements of ten kinds of fish species at Beijing market by INAA

    International Nuclear Information System (INIS)

    Yuan Guojun; Xiao Caijin; Jin Xiangchun; Yang Wei; Zhang Guiying; Wang Pingsheng; Hua Long; Ni Bangfa

    2013-01-01

    Background: As the improvement of the living standard, the safety of food becomes more and more concerned currently. The fish is healthy food with more protein but less fat. Purpose: We bought ten species of fish from the market, which are often eaten by Chinese, and analyzed the trace elements of them by instrumental neutron activation analysis (INAA). So some detecting methods should be applied to give some suggestions for human. Methods: First of all, we choose six species of fresh water fish, including grass carp, weever, Wuchang Fish, tilapia, crucian, carp, and four species of frozen sea fish, including hairtail, yellow croaker, salmon, ling. All of them were collected from a supermarket in Beijing. Secondly, we remove the squama by Teflon coated scissor, wash the fish with de-ionized water and use ashless filter paper to absorb the water on the fish. Then we cut the squama-less part with titanium knife for about 10 g, put them into plastic bags separately and sealed, balance the net weight, use a tablet machine to press them into slice and freeze at -18℃ for 12 h. And then we put them into a vacuum desiccator to pump for 72 h, balance dry fish, calculate the ratio of moisture and triturate the sample into about 40 meshes in agate. Finally, we prepare three sub-samples about 300 mg with each packed by plastic bag for analysis. We put the samples, NIST-1632a and chemical standard material together, irradiate in micro neutron source reactor (MNSR) for 16 h, measure the radioactivity by Ge detector after cooling 5 d or 10 d, and calculate the contents of 16 elements by the ko-NAA and the relative method. Results: The contents of trace elements are different between fresh water fish and sea fish. The contents of As, Hg, Br: Na, Se in sea fish are apparently higher than fresh water fish, but the contents of Rb and Zn are contrary. Considering most fresh water fishes are feed, Zn was probably added in fodder. The content of As in weever is 2.4 μg·g -1 , the

  6. Food limitation of sea lion pups and the decline of forage off central and southern California

    Science.gov (United States)

    McClatchie, Sam; Field, John; Thompson, Andrew R.; Gerrodette, Tim; Lowry, Mark; Fiedler, Paul C.; Watson, William; Nieto, Karen M.; Vetter, Russell D.

    2016-01-01

    California sea lions increased from approximately 50 000 to 340 000 animals in the last 40 years, and their pups are starving and stranding on beaches in southern California, raising questions about the adequacy of their food supply. We investigated whether the declining sea lion pup weight at San Miguel rookery was associated with changes in abundance and quality of sardine, anchovy, rockfish and market squid forage. In the last decade off central California, where breeding female sea lions from San Miguel rookery feed, sardine and anchovy greatly decreased in biomass, whereas market squid and rockfish abundance increased. Pup weights fell as forage food quality declined associated with changes in the relative abundances of forage species. A model explained 67% of the variance in pup weights using forage from central and southern California and 81% of the variance in pup weights using forage from the female sea lion foraging range. A shift from high to poor quality forage for breeding females results in food limitation of the pups, ultimately flooding animal rescue centres with starving sea lion pups. Our study is unusual in using a long-term, fishery-independent dataset to directly address an important consequence of forage decline on the productivity of a large marine predator. Whether forage declines are environmentally driven, are due to a combination of environmental drivers and fishing removals, or are due to density-dependent interactions between forage and sea lions is uncertain. However, declining forage abundance and quality was coherent over a large area (32.5–38° N) for a decade, suggesting that trends in forage are environmentally driven. PMID:27069651

  7. Comparison of the Condition Factor of Five Fish Species of the Araguaia River Basin, Central Brazil

    Directory of Open Access Journals (Sweden)

    Bruno Bastos Gonçalves

    2016-06-01

    Full Text Available This study aims to assess the condition factor (K of five fish species (Serrasalmus rhombeus, Psectrogaster amazonica, Loricaria cataphracta, Panaque nigrolineatus and Squaliforma emarginata. Samplings were conducted during the low-water period of 2007 and 2008 using gillnets and minnow traps. All equipments were placed along a stretch of 1000 m at 5 pm and retrieved at 7 am. Collected fish were taxonomically identified, weighed (g and measured (standard length; mm. The fish fitness was assessed by the condition factor (K=W/L³ and compared among groups of tributaries by a Kruskal-Wallis test. From the five species considered, two (S. emarginata and P. amazonica displayed significant differences of the condition factor among the groups of tributaries. The highest values of K correspond to fish located in the headwaters, while lowest values are observed in tributaries located in the floodplain.

  8. Some peculiarities of fish abundance, species and sizes distribution, and spacing

    International Nuclear Information System (INIS)

    Astrauskas, A.; Bernotas, E.; Jovaisha, R.

    1995-01-01

    During the construction and exploitation process of Ignalina NPP the abundance of fishes has dropped, and especially stenothermic species (smelt and vendace). The general increase of fish abundance is observed in recent years (1992-1994). This is linked with changes of fish species and their adaptation to the new environmental conditions. Now the partial renovation of vendace abundance is observed, too. It is a result of free feeding recess coming out as the smelt dramatically decreased. Before now the ecosystem of the lake is greatly disbalanced due to antropogenetic impact of the NPP. It's partial stabilisation (but on the essentially high level) is possible only in some generations of fish living in the lake. (author). 18 refs., 1 tab., 11 figs

  9. Determination of chromium, mercury, selenium and zinc in marine fish species of Malaysia

    International Nuclear Information System (INIS)

    Nazaratul Ashifa Abdullah Salim; Wee, B.S.; Ezwiza Sanuri; Mohd Suhaimi Hamzah; Mohd Suhaimi Elias, Shamsiah Abdul Rahman; Azian Hashim

    2013-01-01

    Full-text: Concentrations of chromium, mercury, selenium and zinc were determined in eight commonly edible marine fish species; mackerel, red snapper, thread fin, tuna, hard tail scads, val, doubled spotted queen fish and shark. This study was based on market basket method were those species were collected from two locations of Kuala Selangor and Kuala Terengganu. All elements were measured using instrumental neutron activation analysis (INAA) technique. The accuracy and precision analysis were checked by analyzing Certified Reference Material (CRM) namely DORM-3 and MAA-2. Elements of interest in the edible parts of the investigated fish were mostly in the permissible safety levels for human consumption based on national and international safety guideline except for mercury where some fishes showed slightly higher concentrations than the guidelines. (author)

  10. Helminth communities of four commercially important fish species from Chetumal Bay, Mexico.

    Science.gov (United States)

    Aguirre-Macedo, M L; Vidal-Martínez, V M; González-Solís, D; Caballero, P I

    2007-03-01

    The relative importance of ecology and evolution as factors determining species richness and composition of the helminth communities of fish is a matter of current debate. Theoretical studies use host-parasite lists, but these do not include studies on a temporal or spatial scale. Local environmental conditions and host biological characteristics are shown to influence helminth species richness and composition in four fish species (Eugerres plumieri, Hexanematichthys assimilis, Oligoplites saurus, and Scomberomorus maculatus) in Chetumal Bay, Mexico. With the exception of H. assimilis, the helminth communities had not been previously studied and possible associations between environmental and host biological characteristics as factors determining helminth species richness and composition using redundancy analysis (RDA) are described. Thirty-four helminth species are identified, with the highest number of species (19 total (mean = 6.3 +/- 2.1)) and the lowest (9 (4.0 +/- 1.0)) occurring in H. assimilis and S. maculatus, respectively. The larval nematodes Contracaecum sp. and Pseudoterranova sp. were not only the helminth species shared by all four host species but also were the most prevalent and abundant. Statistical associations between helminth community parameters and local ecological variables such as host habitat use, feeding habits, mobility, and time of residence in coastal lagoons are identified. Phylogeny is important because it clearly separates all four host species by their specialist parasites, although specific habitat and feeding habits also significantly influence the differentiation between the four fish species.

  11. Abundance, distribution and species composition of fish larvae in ...

    African Journals Online (AJOL)

    improving our knowledge of the abundance, distribution and species diversity ... banks as well as in the mid-channel, thus eliminating any bias that might have .... cond method (Table 2) may bias the importance of a single species due to one, ...

  12. Identity and distribution of southern African sciaenid fish species of ...

    African Journals Online (AJOL)

    Two Umbrina species, U. canariensis Valenciennes 1843 and U. robinsoni Gilchrist and Thompson 1908, are recognised from southern Africa. The latter species was hitherto believed to be a synonym of Umbrina ronchus Valenciennes 1843 (type locality Canary Islands). U. canariensis is distributed along the South Africa ...

  13. TOXICITY OF PENTACHLOROPHENOL TO ENDANGERED AND SURROGATE FISH SPECIES

    Science.gov (United States)

    Water quality criteria (WQC) generally are based on the responses of easily cultured and tested surrogate species. Little is known about the relative sensitivity of surrogate and endangered species. The objective of this study was to compare acute and chronic (early life-stage) ...

  14. Target strength of some European fish species and its dependence on fish body parameters

    Czech Academy of Sciences Publication Activity Database

    Frouzová, Jaroslava; Kubečka, Jan; Balk, H.; Frouz, Jan

    2005-01-01

    Roč. 75, 1-3 (2005), s. 86-96 ISSN 0165-7836 R&D Projects: GA AV ČR(CZ) IBS6017004 Institutional research plan: CEZ:AV0Z6017912 Keywords : target strength * freshwater fish * acoustics Subject RIV: EH - Ecology, Behaviour Impact factor: 1.160, year: 2005

  15. Identification of Cryptosporidium Species in Fish from Lake Geneva (Lac Léman) in France.

    Science.gov (United States)

    Certad, Gabriela; Dupouy-Camet, Jean; Gantois, Nausicaa; Hammouma-Ghelboun, Ourida; Pottier, Muriel; Guyot, Karine; Benamrouz, Sadia; Osman, Marwan; Delaire, Baptiste; Creusy, Colette; Viscogliosi, Eric; Dei-Cas, Eduardo; Aliouat-Denis, Cecile Marie; Follet, Jérôme

    2015-01-01

    Cryptosporidium, a protozoan parasite that can cause severe diarrhea in a wide range of vertebrates including humans, is increasingly recognized as a parasite of a diverse range of wildlife species. However, little data are available regarding the identification of Cryptosporidium species and genotypes in wild aquatic environments, and more particularly in edible freshwater fish. To evaluate the prevalence of Cryptosporidiumspp. in fish from Lake Geneva (Lac Léman) in France, 41 entire fish and 100 fillets (cuts of fish flesh) were collected from fishery suppliers around the lake. Nested PCR using degenerate primers followed by sequence analysis was used. Five fish species were identified as potential hosts of Cryptosporidium: Salvelinus alpinus, Esox lucius, Coregonus lavaretus, Perca fluviatilis, and Rutilus rutilus. The presence of Cryptosporidium spp. was found in 15 out of 41 fish (37%), distributed as follows: 13 (87%) C. parvum, 1 (7%) C. molnari, and 1 (7%) mixed infection (C. parvum and C. molnari). C. molnari was identified in the stomach, while C. parvum was found in the stomach and intestine. C. molnari was also detected in 1 out of 100 analyzed fillets. In order to identify Cryptosporidium subtypes, sequencing of the highly polymorphic 60-kDa glycoprotein (gp60) was performed. Among the C. parvum positive samples, three gp60 subtypes were identified: IIaA15G2R1, IIaA16G2R1, and IIaA17G2R1. Histological examination confirmed the presence of potential developmental stages of C. parvum within digestive epithelial cells. These observations suggest that C. parvum is infecting fish, rather than being passively carried. Since C. parvum is a zoonotic species, fish potentially contaminated by the same subtypes found in terrestrial mammals would be an additional source of infection for humans and animals, and may also contribute to the contamination of the environment with this parasite. Moreover, the risk of human transmission is strengthened by the

  16. Identification of Cryptosporidium Species in Fish from Lake Geneva (Lac Léman in France.

    Directory of Open Access Journals (Sweden)

    Gabriela Certad

    Full Text Available Cryptosporidium, a protozoan parasite that can cause severe diarrhea in a wide range of vertebrates including humans, is increasingly recognized as a parasite of a diverse range of wildlife species. However, little data are available regarding the identification of Cryptosporidium species and genotypes in wild aquatic environments, and more particularly in edible freshwater fish. To evaluate the prevalence of Cryptosporidiumspp. in fish from Lake Geneva (Lac Léman in France, 41 entire fish and 100 fillets (cuts of fish flesh were collected from fishery suppliers around the lake. Nested PCR using degenerate primers followed by sequence analysis was used. Five fish species were identified as potential hosts of Cryptosporidium: Salvelinus alpinus, Esox lucius, Coregonus lavaretus, Perca fluviatilis, and Rutilus rutilus. The presence of Cryptosporidium spp. was found in 15 out of 41 fish (37%, distributed as follows: 13 (87% C. parvum, 1 (7% C. molnari, and 1 (7% mixed infection (C. parvum and C. molnari. C. molnari was identified in the stomach, while C. parvum was found in the stomach and intestine. C. molnari was also detected in 1 out of 100 analyzed fillets. In order to identify Cryptosporidium subtypes, sequencing of the highly polymorphic 60-kDa glycoprotein (gp60 was performed. Among the C. parvum positive samples, three gp60 subtypes were identified: IIaA15G2R1, IIaA16G2R1, and IIaA17G2R1. Histological examination confirmed the presence of potential developmental stages of C. parvum within digestive epithelial cells. These observations suggest that C. parvum is infecting fish, rather than being passively carried. Since C. parvum is a zoonotic species, fish potentially contaminated by the same subtypes found in terrestrial mammals would be an additional source of infection for humans and animals, and may also contribute to the contamination of the environment with this parasite. Moreover, the risk of human transmission is strengthened by

  17. Effects of industrial processing on the immunogenicity of commonly ingested fish species.

    Science.gov (United States)

    Sletten, Gaynour; Van Do, Thien; Lindvik, Helene; Egaas, Eliann; Florvaag, Erik

    2010-01-01

    Food-processing techniques may induce changes in fish protein immunogenicity. Allergens from >100 fish species have been identified, but little is known on the effects of processing on fish protein immunogenicity. IgE binding of sera of patients allergic to fresh and processed (smoked, salted/sugar-cured, canned, lye-treated and fermented) cod, haddock, salmon, trout, tuna, mackerel and herring and of hydrolysates based on salmon and whiting was investigated using immunoblot and inhibition ELISA. Parvalbumin oligomers were identified using monoclonal and polyclonal antibodies. IgE binding was seen in most sera at 12-14 kDa (parvalbumin), and at 17-60 kDa for all fish except tuna. Changes in IgE binding appeared to reflect altered parvalbumin monomers and oligomers. Smoked haddock, salmon and mackerel had increased IgE binding and novel bands at 30 kDa. Chemically processed cod, salmon, trout and pickled herring had reduced or abolished IgE binding. The serum of 1 subject, however, had increased IgE binding to these products and also inhibition of binding by both fish hydrolysates to their constituent fish species. Process-induced changes in fish protein immunogenicity were more dependent on process rather than species, although individual responses varied. Changes in the allergenicity of a product may depend on the net effect of processing on parvalbumin oligomerization patterns, which may also vary in different species. Chemical processes generally caused loss in IgE-binding activity, though sensitization may occur to modified or degraded rather than intact peptides as shown by increased binding by chemically processed fish and hydrolysates in 1 subject. The clinical significance of these findings remains to be established.

  18. Species Profiles. Life Histories and Environmental Requirements of Coastal Fishes and Invertebrates (Pacific Southwest) Crangonid Shrimp

    Science.gov (United States)

    1989-12-01

    Engineers, TR EL-82-4. 18 pp. PREFACE This species profile is one of a series on coastal aquatic organisms, principally fish, of sport , commercial, or...in the spring documented. These shrimp are often the and summer in coastal embayments but are predominant food of the principal sport and abundant...inhibit gonadogenesis and Department of Fish and Game 1987), suggesting castrated male shrimp would take on feminizing that environmental conditions

  19. Salinity and temperature tolerance of an emergent alien species, the Amazon fish Astronotus ocellatus

    Science.gov (United States)

    Gutierrel, Silvia M M; Schofield, Pam; Prodocimo, Viviane

    2016-01-01

    Astronotus ocellatus (oscar), is native to the Amazon basin and, although it has been introduced to many countries, little is known regarding its tolerances for salinity and temperature. In this report, we provide data on the tolerance of A. ocellatus to abrupt and gradual changes in salinity, its high and low temperature tolerance, and information on how salinity, temperature, and fish size interact to affect survival. Fish were able to survive abrupt transfer to salinities as high as 16 ppt with no mortality. When salinity change was gradual (2 ppt/day), fish in the warm-temperature experiment (28°C) survived longer than fish in the cool-temperature experiment (18°C). Larger fish survived longer than smaller ones at the higher salinities when the temperature was warm, but when the temperature was cool fish size had little effect on survival. In the temperature-tolerance experiments, fish survived from 9 to 41°C for short periods of time. Overall, the species showed a wide range of temperature and salinity tolerance. Thus, in spite of the tropical freshwater origin of this species, physiological stress is not likely to hinder its dispersal to brackish waters, especially when temperatures are warm.

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

    Directory of Open Access Journals (Sweden)

    Jolanta Morozińska-Gogol

    2009-03-01

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

  1. Accumulation of /sup 210/Po in selected species of Baltic fish

    Energy Technology Data Exchange (ETDEWEB)

    Skwarzec, B

    1988-01-01

    Results are presented here for the /sup 210/Po contents of selected species of Baltic fish. It is shown that /sup 210/Po is non-uniformly distributed within these fish, the highest levels being found in the digestive organs, particularly within the intestine. It is found that the proportional contribution by the digestive organs to the total accumulation of /sup 210/Po is correlated with the degree of repletion of the stomach and that this decreases if food is lacking. Moreover, it is observed that fish represent an important source of supply of /sup 210/Po to humans.

  2. The foraging behaviour of herons and egrets on the Magela Creek flood plain, Northern Territory

    International Nuclear Information System (INIS)

    Recher, H.F.; Holmes, R.T.

    1982-03-01

    Five species of diurnal herons are common on the Magela Creek flood plain and forage along the edges of natural and artifical waterbodies both inside and outside the Ranger Uranium Project Area. The species of heron differ in the kinds and sizes of prey they take, their foraging location, degree of sociality and foraging behaviour. Because it takes relatively large fish, the Great Egret, E. alba, is most likely to be affected by any contamination of the aquatic environment by heavy metals or radionuclides. The Nankeen Night Heron, Nycticorax caledonicus is also abundant on the flood plain and probably feeds on large fish and frogs. The other herons take smaller or immature prey or hunt mostly in terrestrial habitats and are therefore less likely to be affected by contamination of the aquatic environment

  3. Radioactive contamination of the significant fish species in fish-ponds and in natural waters with particular respect to the accumulation of Sr-90 Pt. 2

    International Nuclear Information System (INIS)

    Kantor, D.; Szentjobi, O.

    1977-01-01

    The radioactive contamination of omnivorous fish species (Cyprinus carpio, Hypophtalmictys nobilis Richardson), of herbivorous fish species (Hypophtalmictys molitrix Valenciennes) and carnivorous fish species (Silurus glanis L., Esox Lucius L.) has been investigated. Orientative data have been obtained by analyzing samples originating from various sites. Though differences appeared between the analyzed samples, no incorporations of outstanding nature have been observed. In accordance with experiences described in literature, the isotope Sr-90 is accumulated in an increased degree in the skeleton of fish living in ponds. This is valid in all cases when the vital processes are regulated artificially by fishery methods. A particularly important factor is that the individual fish living in ponds are 2-3 or at most 4 years of age i.e. from the aspect of their ontogenesis their organism is in a strongly build-up phase. Sr-90 proved to be accumulated in a relatively greater amount in the organisms of herbivorous fish. (P.J.)

  4. Nutritive values of some food plants, fresh and processed fish species

    Directory of Open Access Journals (Sweden)

    Ali Aberoumand

    2015-12-01

    Full Text Available The chemical composition of four edible plant foods species, three fish species and one prawn were analyzed in Food Chemistry Laboratory of Behbahan Khatam Alanbia University of Technology, Behbahan, Iran in 2014. The analysis of fatty acid and sugars composition were performed by gas liquid chromatography and high performance liquid chromatography, respectively. Protein and lipid content were founded higher in baked and fried in fish S. commersonnianus (74.29%, (20.20%, fish Sphyraena helleri (88.12% and (17.77%, respectively. Ash content in fish S. commersonnianus varies from 9.80% to 15.34%, and in fish S. helleri from 5.83% to 7.68%. Based on the proximate analysis, it can be calculated that an edible portion of 100 g of studied edible plant foods provides, on average, around 303.9±1.04 kcal. The plant Portulaca neglecta is suitable for high temperature food processes. The macronutrient profile in general revealed that the wild plant foods were with rich sources of protein and carbohydrates, and had low amounts of fat. The highest protein, the lowest fat and energy contents were found in boiled in both fish species; therefore, boiling can be recommended as the best cooking method for healthy diet.

  5. Fish, fans and hydroids: host species of pygmy seahorses

    Directory of Open Access Journals (Sweden)

    Bastian Reijnen

    2011-06-01

    Full Text Available An overview of the octocoral and hydrozoa host species of pygmy seahorses is provided, based on recently collected data for H. bargibanti, H. denise and H. pontohi and literature records. Seven new interspecific host-species associations are recognized, and an overview of the so far documented number of host species is given. Detailed re-examination of octocoral type material and a review of the taxonomic history are included, as a baseline for further studies. The host-specificity and colour morphs of pygmy seahorses are discussed, as well as the validity of (previous identifications and conservations issues.

  6. Underappreciated species in ecology: "ugly fish" in the northwest Atlantic Ocean.

    Science.gov (United States)

    Link, Jason S

    2007-10-01

    Species shifts and replacements are common in ecological studies. Observations thereof serve as the impetus for many ecological endeavors. Many of the species now known to dominate ecosystem functioning were largely ignored until studies of those underappreciated species elucidated their critical roles. Recognizing the potential importance of underappreciated species has implications for functional redundancies in ecosystems and should alter our approach to long-term monitoring. One example of an applied ecological system containing species shifts, underappreciated species, and potential changes in functional redundancies is the topic of fisheries. The demersal component of many fish communities usually consists of high-profile and commercially valuable species that are targets of fisheries, plus a diverse group of lesser known species that have minimal commercial value and focus. Yet ecologically these traditionally nontargeted species are often a major biomass sink in marine ecosystems and can also be critical in the functioning of bentho-demersal food webs. I examined the biomass trajectories of several species of skates, cottids, lophiids, anarhichadids, zooarcids, and similar species in the northeast U.S. Atlantic ecosystem to determine whether their relative abundance has changed across the past four decades. Distribution and stomach contents of these species were also evaluated over time to further elucidate the relative importance of these species. Landings of these underappreciated bentho-demersal fish were also examined in comparison to those species that historically have been commercially targeted. Of particular emphasis was the evaluation of evidence for sequential stock depletion and the ramifications for functional redundancy for this ecosystem. Results indicate that some of these fish species are now the dominant piscivores, benthivores, and scavengers in this ecosystem. These formerly under-studied species generally have either maintained a

  7. The commercial viability of any intensively cultured fish species ...

    African Journals Online (AJOL)

    spamer

    acids. It is, however, the protein in the diet that pro- vides the amino acids. Inadequate protein in the ..... nivorous species such as Atlantic salmon Salmo salar and striped bass Morone ... tailed investigations on essential fatty acid and amino.

  8. Characterization of Vibrio species isolated from freshwater fishes by ribotyping

    OpenAIRE

    Mishra, P.; Samanta, M.; Mohanty, S.; Maiti, N. K.

    2010-01-01

    Three Vibrio species from the resident microflora of gastrointestinal tract of freshwater carps and prawns were isolated and confirmed biochemically as V. fluvialis from Cyprinus carpio/Labeo rohita; V. parahaemolyticus from Macrobrachium rosenbergii and V. harveyi from Macrobrachium malcomsoni. The genetic relationship among these Vibrio species was carried out by polymerase chain reaction (PCR) amplification of 16S rRNA gene followed by restriction digestion with Hae III, Bam HI and Pst I. ...

  9. [Dietary composition and food competition of six main fish species in rocky reef habitat off Gouqi Island].

    Science.gov (United States)

    Wang, Kai; Zhang, Shou-Yu; Wang, Zhen-Hua; Zhao, Jing; Xu, Min; Lin, Jun

    2012-02-01

    Based on the monthly investigation data of fish resources in the rocky reef habitat off Gouqi Island from March 2009 to February 2010, this paper studied the dietary composition of three native fish species (Sebasticus marmoratus, Hexagrammos otakii and Hexagrammos agrammus) and three non-native fish species (Lateolabrax japonica, Nibea albiflora and Larimichthys polyactis). The analysis of gut content indicated that the main prey items of these six dominant fish species were Caprellidae, Gammaridea, juvenile S. marmoratus, Engraulis japonicas and Acetes chinensis and the dietary composition of each of the 6 fish species had obvious seasonal variation. There was an intense food competition between native species H. otakii and H. agrammus in autumn, between non-native species N. albiflora and L. polyactis in summer, between non-native species N. albiflora and native species S. marmoratus in autumn, and between non-native species N. albiflora and native species H. otakii in winter. It was suggested the non-native species N. albiflora was the key species in the food competition among the six dominant fish species in this rocky reef habitat, and thus the feeding behaviors of these six fish species could have definite effects on the resource capacity of juvenile S. marmoratus.

  10. Hierarchical faunal filters: An approach to assessing effects of habitat and nonnative species on native fishes

    Science.gov (United States)

    Quist, M.C.; Rahel, F.J.; Hubert, W.A.

    2005-01-01

    Understanding factors related to the occurrence of species across multiple spatial and temporal scales is critical to the conservation and management of native fishes, especially for those species at the edge of their natural distribution. We used the concept of hierarchical faunal filters to provide a framework for investigating the influence of habitat characteristics and normative piscivores on the occurrence of 10 native fishes in streams of the North Platte River watershed in Wyoming. Three faunal filters were developed for each species: (i) large-scale biogeographic, (ii) local abiotic, and (iii) biotic. The large-scale biogeographic filter, composed of elevation and stream-size thresholds, was used to determine the boundaries within which each species might be expected to occur. Then, a local abiotic filter (i.e., habitat associations), developed using binary logistic-regression analysis, estimated the probability of occurrence of each species from features such as maximum depth, substrate composition, submergent aquatic vegetation, woody debris, and channel morphology (e.g., amount of pool habitat). Lastly, a biotic faunal filter was developed using binary logistic regression to estimate the probability of occurrence of each species relative to the abundance of nonnative piscivores in a reach. Conceptualising fish assemblages within a framework of hierarchical faunal filters is simple and logical, helps direct conservation and management activities, and provides important information on the ecology of fishes in the western Great Plains of North America. ?? Blackwell Munksgaard, 2004.

  11. Trace elements in muscle of three fish species from Todos os Santos Bay, Bahia State, Brazil.

    Science.gov (United States)

    de Santana, Carolina Oliveira; de Jesus, Taíse Bomfim; de Aguiar, William Moura; de Jesus Sant'anna Franca-Rocha, Washington; Soares, Carlos Alberto Caroso

    2017-03-01

    In this study, an analysis was performed on the concentrations of the trace elements Al, As, Ba, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, V, and Zn in muscle of two carnivorous and one planktivorous fish species collected at Todos os Santos Bay (BTS). The accumulation order of the trace elements in Lutjanus analis was Al >Zn >Fe >Cr >Ba >Ni. In Cetengraulis edentulus, the order was Al >Fe >Zn >Cr >Ni >Mn >As. In the species Diapterus rhombeus, the order was Al >Fe >Zn >Cr >Ni >Mn >Cd. To determine the risk related to the consumption of fish, toxicity guidelines were used as standard references. It was observed that the species C. edentulus contained concentrations of As exceeding WHO limits, but these concentrations were acceptable according to the Agência Nacional de Vigilância Sanitária (ANVISA) guidelines. Cd levels were found only in D. rhombeus and in low concentrations according to the determinations of WHO and ANVISA. Pb levels were not detected in any of the three fish species. The analyzed elements did not differ statistically according to the species and feeding habits. The results point to possible risks of human contamination by As related to the consumption of the fish species C. edentulus from the BTS.

  12. Early life of key fish species, capelin Mallotus villosus and Atlantic cod Gadus morhua, in West Greenland

    DEFF Research Database (Denmark)

    Malanski, Evandro

    for the fish larvae during the summer. The duration of the productive season is of great importance for the early life of fish. The present thesis investigates the diets of capelin and cod in the subarctic Kapisigdlit, as well as the feeding of non-commercial larval fish in the entire Godthåbsfjord system...... species were found in the area, and 3 main assemblages were identified according to their similarities, which are related to the hydrographic zones. Fish larvae may benefit from the estuarine circulation to distribute themselves from the spawning areas through the Godthåbsfjord. The diet of the larval...... fish species varied markedly along the fjord. Prey size preferences of fish larvae were positively correlated to their mouth sizes. American plaice and sandeel were probably do not compete for food with other fish species since these, contrary to other species, had high preference for microplankton...

  13. Quantifying tolerance indicator values for common stream fish species of the United States

    Science.gov (United States)

    Meador, M.R.; Carlisle, D.M.

    2007-01-01

    The classification of fish species tolerance to environmental disturbance is often used as a means to assess ecosystem conditions. Its use, however, may be problematic because the approach to tolerance classification is based on subjective judgment. We analyzed fish and physicochemical data from 773 stream sites collected as part of the U.S. Geological Survey's National Water-Quality Assessment Program to calculate tolerance indicator values for 10 physicochemical variables using weighted averaging. Tolerance indicator values (TIVs) for ammonia, chloride, dissolved oxygen, nitrite plus nitrate, pH, phosphorus, specific conductance, sulfate, suspended sediment, and water temperature were calculated for 105 common fish species of the United States. Tolerance indicator values for specific conductance and sulfate were correlated (rho = 0.87), and thus, fish species may be co-tolerant to these water-quality variables. We integrated TIVs for each species into an overall tolerance classification for comparisons with judgment-based tolerance classifications. Principal components analysis indicated that the distinction between tolerant and intolerant classifications was determined largely by tolerance to suspended sediment, specific conductance, chloride, and total phosphorus. Factors such as water temperature, dissolved oxygen, and pH may not be as important in distinguishing between tolerant and intolerant classifications, but may help to segregate species classified as moderate. Empirically derived tolerance classifications were 58.8% in agreement with judgment-derived tolerance classifications. Canonical discriminant analysis revealed that few TIVs, primarily chloride, could discriminate among judgment-derived tolerance classifications of tolerant, moderate, and intolerant. To our knowledge, this is the first empirically based understanding of fish species tolerance for stream fishes in the United States.

  14. Multi-scale approach for predicting fish species distributions across coral reef seascapes.

    Directory of Open Access Journals (Sweden)

    Simon J Pittman

    Full Text Available Two of the major limitations to effective management of coral reef ecosystems are a lack of information on the spatial distribution of marine species and a paucity of data on the interacting environmental variables that drive distributional patterns. Advances in marine remote sensing, together with the novel integration of landscape ecology and advanced niche modelling techniques provide an unprecedented opportunity to reliably model and map marine species distributions across many kilometres of coral reef ecosystems. We developed a multi-scale approach using three-dimensional seafloor morphology and across-shelf location to predict spatial distributions for five common Caribbean fish species. Seascape topography was quantified from high resolution bathymetry at five spatial scales (5-300 m radii surrounding fish survey sites. Model performance and map accuracy was assessed for two high performing machine-learning algorithms: Boosted Regression Trees (BRT and Maximum Entropy Species Distribution Modelling (MaxEnt. The three most important predictors were geographical location across the shelf, followed by a measure of topographic complexity. Predictor contribution differed among species, yet rarely changed across spatial scales. BRT provided 'outstanding' model predictions (AUC = >0.9 for three of five fish species. MaxEnt provided 'outstanding' model predictions for two of five species, with the remaining three models considered 'excellent' (AUC = 0.8-0.9. In contrast, MaxEnt spatial predictions were markedly more accurate (92% map accuracy than BRT (68% map accuracy. We demonstrate that reliable spatial predictions for a range of key fish species can be achieved by modelling the interaction between the geographical location across the shelf and the topographic heterogeneity of seafloor structure. This multi-scale, analytic approach is an important new cost-effective tool to accurately delineate essential fish habitat and support

  15. Comparison of Mitochondrial Reactive Oxygen Species Production of Ectothermic and Endothermic Fish Muscle

    Directory of Open Access Journals (Sweden)

    Lilian Wiens

    2017-09-01

    Full Text Available Recently we demonstrated that the capacity of isolated muscle mitochondria to produce reactive oxygen species, measured as H2O2 efflux, is temperature-sensitive in isolated muscle mitochondria of ectothermic fish and the rat, a representative endothermic mammal. However, at physiological temperatures (15° and 37°C for the fish and rat, respectively, the fraction of total mitochondrial electron flux that generated H2O2, the fractional electron leak (FEL, was far lower in the rat than in fish. Those results suggested that the elevated body temperatures associated with endothermy may lead to a compensatory decrease in mitochondrial ROS production relative to respiratory capacity. To test this hypothesis we compare slow twitch (red muscle mitochondria from the endothermic Pacific bluefin tuna (Thunnus orientalis with mitochondria from three ectothermic fishes [rainbow trout (Oncorhynchus mykiss, common carp (Cyprinus carpio, and the lake sturgeon (Acipenser fulvescens] and the rat. At a common assay temperature (25°C rates of mitochondrial respiration and H2O2 efflux were similar in tuna and the other fishes. The thermal sensitivity of fish mitochondria was similar irrespective of ectothermy or endothermy. Comparing tuna to the rat at a common temperature, respiration rates were similar, or lower depending on mitochondrial substrates. FEL was not different across fish species at a common assay temperature (25°C but was markedly higher in fishes than in rat. Overall, endothermy and warming of Pacific Bluefin tuna red muscle may increase the potential for ROS production by muscle mitochondria but the evolution of endothermy in this species is not necessarily associated with a compensatory reduction of ROS production relative to the respiratory capacity of mitochondria.

  16. Experimental infection of Aphanomyces invadans and susceptibility in seven species of tropical fish

    Directory of Open Access Journals (Sweden)

    Seyedeh F. Afzali

    2015-09-01

    Full Text Available Aim: Epizootic ulcerative syndrome (EUS causes by aquatic oomycete fungus, Aphanomyces invadans is a dangerous fish disease of a wide range of fresh and brackish water, wild and farmed fish throughout the world. The objective of the present study was to determine the susceptibility of a number of tropical fish species to the EUS and compare the severity of infection between experimental groups. Materials and Methods: Snakehead, Channa striata (Bloch, 1793; snakeskin gourami, Trichopodus pectoralis (Regan, 1910; koi carp, Cyprinus carpio (Linnaeus, 1758; broadhead catfish, Clarias macrocephalus (Günther, 1864; goldfish, Carassius auratus (Linnaeus, 1758; climbing perch, Anabas testudineus (Bloch, 1792; and Nile tilapia, Oreochromis niloticus (Linnaeus, 1758 were challenged by intramuscular injection using zoospores of Aphanomyces invadans (NJM9701. The infected fish skins and muscles were examined for EUS histopathological characteristics, and the results on the severity of lesions and mortality were analyzed using SPSS program. Results: All zoospore-injected fish were shown to be susceptible to the EUS infection except Nile tilapia. Although, the general histopathological pattern was similar in the zoospore-injected group, but there were some variation in granulomatous reaction, that is the presence or absence of giant cells, and time of mortality were detected. The result of statistical analysis showed that there was a significant difference between species, (c2=145.11 and p<0.01. Conclusion: Gourami, koi carp, and catfish were demonstrated to be highly susceptible while goldfish and climbing perch were found to be moderately susceptible to the EUS infection. These findings suggested that the cellular response of fish to mycotic infection and granulomatous reaction varied in different fish species, which could not be an indicator of susceptibility or resistant to the EUS itself, although it was shown that the granulation rate and the level of

  17. Warmed Winter Water Temperatures Alter Reproduction in Two Fish Species.

    Science.gov (United States)

    Firkus, Tyler; Rahel, Frank J; Bergman, Harold L; Cherrington, Brian D

    2018-02-01

    We examined the spawning success of Fathead Minnows (Pimephales promelas) and Johnny Darters (Etheostoma nigrum) exposed to elevated winter water temperatures typical of streams characterized by anthropogenic thermal inputs. When Fathead Minnows were exposed to temperature treatments of 12, 16, or 20 °C during the winter, spawning occurred at 16 and 20 °C but not 12 °C. Eggs were deposited over 9 weeks before winter spawning ceased. Fathead Minnows from the three winter temperature treatments were then exposed to a simulated spring transition. Spawning occurred at all three temperature treatments during the spring, but fish from the 16° and 20 °C treatment had delayed egg production indicating a latent effect of warm winter temperatures on spring spawning. mRNA analysis of the egg yolk protein vitellogenin showed elevated expression in female Fathead Minnows at 16 and 20 °C during winter spawning that decreased after winter spawning ceased, whereas Fathead Minnows at 12 °C maintained comparatively low expression during winter. Johnny Darters were exposed to 4 °C to represent winter temperatures in the absence of thermal inputs, and 12, 16, and 20 °C to represent varying degrees of winter thermal pollution. Johnny Darters spawned during winter at 12, 16, and 20 °C but not at 4 °C. Johnny Darters at 4 °C subsequently spawned following a simulated spring period while those at 12, 16, and 20 °C did not. Our results indicate elevated winter water temperatures common in effluent-dominated streams can promote out-of-season spawning and that vitellogenin expression is a useful indicator of spawning readiness for fish exposed to elevated winter temperatures.

  18. Warmed Winter Water Temperatures Alter Reproduction in Two Fish Species

    Science.gov (United States)

    Firkus, Tyler; Rahel, Frank J.; Bergman, Harold L.; Cherrington, Brian D.

    2018-02-01

    We examined the spawning success of Fathead Minnows ( Pimephales promelas) and Johnny Darters ( Etheostoma nigrum) exposed to elevated winter water temperatures typical of streams characterized by anthropogenic thermal inputs. When Fathead Minnows were exposed to temperature treatments of 12, 16, or 20 °C during the winter, spawning occurred at 16 and 20 °C but not 12 °C. Eggs were deposited over 9 weeks before winter spawning ceased. Fathead Minnows from the three winter temperature treatments were then exposed to a simulated spring transition. Spawning occurred at all three temperature treatments during the spring, but fish from the 16° and 20 °C treatment had delayed egg production indicating a latent effect of warm winter temperatures on spring spawning. mRNA analysis of the egg yolk protein vitellogenin showed elevated expression in female Fathead Minnows at 16 and 20 °C during winter spawning that decreased after winter spawning ceased, whereas Fathead Minnows at 12 °C maintained comparatively low expression during winter. Johnny Darters were exposed to 4 °C to represent winter temperatures in the absence of thermal inputs, and 12, 16, and 20 °C to represent varying degrees of winter thermal pollution. Johnny Darters spawned during winter at 12, 16, and 20 °C but not at 4 °C. Johnny Darters at 4 °C subsequently spawned following a simulated spring period while those at 12, 16, and 20 °C did not. Our results indicate elevated winter water temperatures common in effluent-dominated streams can promote out-of-season spawning and that vitellogenin expression is a useful indicator of spawning readiness for fish exposed to elevated winter temperatures.

  19. Context-dependent interactions and the regulation of species richness in freshwater fish

    Science.gov (United States)

    MacDougall, Andrew S.; Harvey, Eric; McCune, Jenny L.; Nilsson, Karin A.; Bennett, Joseph; Firn, Jennifer; Bartley, Timothy; Grace, James B.; Kelly, Jocelyn; Tunney, Tyler D.; McMeans, Bailey; Matsuzaki, Shin-Ichiro S.; Kadoya, Taku; Esch, Ellen; Cazelles, Kevin; Lester, Nigel; McCann, Kevin S.

    2018-01-01

    Species richness is regulated by a complex network of scale-dependent processes. This complexity can obscure the influence of limiting species interactions, making it difficult to determine if abiotic or biotic drivers are more predominant regulators of richness. Using integrative modeling of freshwater fish richness from 721 lakes along an 11olatitudinal gradient, we find negative interactions to be a relatively minor independent predictor of species richness in lakes despite the widespread presence of predators. Instead, interaction effects, when detectable among major functional groups and 231 species pairs, were strong, often positive, but contextually dependent on environment. These results are consistent with the idea that negative interactions internally structure lake communities but do not consistently ‘scale-up’ to regulate richness independently of the environment. The importance of environment for interaction outcomes and its role in the regulation of species richness highlights the potential sensitivity of fish communities to the environmental changes affecting lakes globally.

  20. Photoactivated toxicity of PAH to endangered fishes and standard laboratory test species

    International Nuclear Information System (INIS)

    Buckler, D.R.; Mount, D.R.; Tillitt, D.E.

    1994-01-01

    Polynuclear aromatic hydrocarbons (PAH) have been detected in water and sediment from the San Juan River Basin, located in the Four Corners area of the southwestern US. In addition to possessing extensive oil and gas deposits, the San Juan contains several threatened or endangered fish species such as Colorado squawfish and razorback suckers. Proposed expansion of oil and gas development in the basin has sparked concerns that potential increases in PAH loading may jeopardize these and other native fishes. In response, the authors conducted laboratory exposures of threatened and endangered species to various PAH both with and without accompanying exposure to UV light. As predicted from the literature, exposure to UV light caused a marked photo-activated toxicity response in all species; however, the sensitivity to PAH both with and without UV exposure varied among species and lifestages. Supplemental studies were conducted to evaluate the physiological mechanisms for variation in sensitivity between species and lifestage

  1. Derived concentration factors for caesium-137 in edible species of North Sea fish

    International Nuclear Information System (INIS)

    Steele, A.K.

    1990-01-01

    Concentration factor (CF=Bq kg -1 fillet/Bg kg -1 filtered sea water) values for 137 Cs in fillets of cod (Gadus morhua), haddock (Merlanogrammus aeglefinus), plaice (Pleuronectes platessa) and whiting (Merlangius merlangius), were derived from fish and filtered seawater concentrations. Samples were collected in twelve sampling boxes in the North Sea over an eight-year period - 1978-1985. The range of results with species, between species, and between surveys are discussed. Mean CF values of 92, 58, 39 and 150 were found in cod, haddock, plaice and whiting respectively. These support the International Atomic Energy Authority recommended CF value of 100 for fish in generalised dose assessments. (author)

  2. Genetic diversity and species diversity of stream fishes covary across a land-use gradient

    Science.gov (United States)

    Blum, M.J.; Bagley, M.J.; Walters, D.M.; Jackson, S.A.; Daniel, F.B.; Chaloud, D.J.; Cade, B.S.

    2012-01-01

    Genetic diversity and species diversity are expected to covary according to area and isolation, but may not always covary with environmental heterogeneity. In this study, we examined how patterns of genetic and species diversity in stream fishes correspond to local and regional environmental conditions. To do so, we compared population size, genetic diversity and divergence in central stonerollers (Campostoma anomalum) to measures of species diversity and turnover in stream fish assemblages among similarly sized watersheds across an agriculture-forest land-use gradient in the Little Miami River basin (Ohio, USA). Significant correlations were found in many, but not all, pair-wise comparisons. Allelic richness and species richness were strongly correlated, for example, but diversity measures based on allele frequencies and assemblage structure were not. In-stream conditions related to agricultural land use were identified as significant predictors of genetic diversity and species diversity. Comparisons to population size indicate, however, that genetic diversity and species diversity are not necessarily independent and that variation also corresponds to watershed location and glaciation history in the drainage basin. Our findings demonstrate that genetic diversity and species diversity can covary in stream fish assemblages, and illustrate the potential importance of scaling observations to capture responses to hierarchical environmental variation. More comparisons according to life history variation could further improve understanding of conditions that give rise to parallel variation in genetic diversity and species diversity, which in turn could improve diagnosis of anthropogenic influences on aquatic ecosystems. ?? 2011 Springer-Verlag.

  3. Can pelagic forage fish and spawning cisco (Coregonus artedi) biomass in the western arm of Lake Superior be assessed with a single summer survey?

    Science.gov (United States)

    Yule, D.L.; Stockwell, J.D.; Schreiner, D.R.; Evrard, L.M.; Balge, M.; Hrabik, T.R.

    2009-01-01

    Management efforts to rehabilitate lake trout Salvelinus namaycush in Lake Superior have been successful and the recent increase in their numbers has led to interest in measuring biomass of pelagic prey fish species important to these predators. Lake Superior cisco Coregonus artedi currently support roe fisheries and determining the sustainability of these fisheries is an important management issue. We conducted acoustic and midwater trawl surveys of the western arm of Lake Superior during three periods: summer (July-August), October, and November 2006 to determine if a single survey can be timed to estimate biomass of both prey fish and spawning cisco. We evaluated our methods by comparing observed trawl catches of small (cisco increased substantially in November, while small bloater Coregonus hoyi biomass was lower. We compared our summer 2006 estimates of total fish biomass to the results of a summer survey in 1997 and obtained similar results. We conclude that the temporal window for obtaining biomass estimates of pelagic prey species in the western arm of Lake Superior is wide (July through October), but estimating spawning cisco abundance is best done with a November survey.

  4. Artificial marine habitats favour a single fish species on a long-term scale: the dominance of Boops boops around off-shore fish cages

    Directory of Open Access Journals (Sweden)

    Rodrigo Riera

    2014-12-01

    Full Text Available Off-shore fish cages are new artificial habitats that can affect pelagic fish assemblages and constitute an important food source for wild fish assemblages. This aggregation has noticeable ecological consequences in cage areas in impoverished ecosystems such as those in the Canary archipelago (NE Atlantic Ocean. However, this new habitat could be dominated by a single species, reducing its positive ecological effects. Wild fish assemblages associated with an off-shore fish lease on the northeastern coast of Tenerife (Canary Islands were sampled for six years. Fish assemblage structure beneath fish cages and at controls ( > 500 m from cages differed significantly between locations, with 13 times greater abundance at cage locations. These differences were mainly explained by the dominance of bogue (Boops boops around fish cages. This trend was consistent in the long-term throughout the study period (2004-2009, affecting local fisheries. The presence of fish cages significantly altered wild fish assemblages in the study area, enhancing mainly biomass and abundance of one species, bogue, and causing shifts in species composition.

  5. Fish, fans and hydroids: host species of pygmy seahorses.

    Science.gov (United States)

    Reijnen, Bastian T; van der Meij, Sancia E T; van Ofwegen, Leen P

    2011-01-01

    An overview of the octocoral and hydrozoan host species of pygmy seahorses is provided based on literature records and recently collected field data for Hippocampus bargibanti, Hippocampus denise and Hippocampus pontohi. Seven new associations are recognized and an overview of the so far documented host species is given. A detailed re-examination of octocoral type material and a review of the taxonomic history of the alcyonacean genera Annella (Subergorgiidae) and Muricella (Acanthogorgiidae) are included as baseline for future revisions. The host specificity and colour morphs of pygmy seahorses are discussed, as well as the reliability of (previous) identifications and conservation issues.

  6. The fish fauna of Anambra river basin, Nigeria: species abundance and morphometry

    Directory of Open Access Journals (Sweden)

    Gregory Ejikeme Odo

    2009-06-01

    Full Text Available The fish yields of most Nigeria inland waters are generally on the decline for causes that may range from inadequate management of the fisheries to degradation of the water bodies. Sustainable exploitation requires knowledge of the ichthyofaunal composition in the water bodies. We did a survey of fish species in Anambra river basin for 22 months. Fish samples were collected using four different gears -hook and line of size 13, caste nets, gill nets, and cages of mesh sizes of 50mm, 75mm, and 100mm each. We recorded 52 fish species belonging to 17 families: 171, 236, and 169 individuals at Ogurugu, Otuocha, and Nsugbe stations respectively. Two families, Characidae, 19.5 %, and Mochokidae, 11.8%, constituted the dominant fish families in the river. The dominant fish species were Citherinus citherius, 9.02%, and Alestes nurse, 7.1%. Other fish species with significant abundance were Synodontis clarias 6.9%, Macrolepidotus curvier 5.7%, Labeo coubie 5.4%, Distichodus rostrtus 4.9%, and Schilbe mystus 4.5%. The meristic features of the two most abundant fish species caught are as follows: Citharinus citharius dorsal fins 20, anal fins 30, caudal fins 21, pectoral fins, 9 and 8 ventral fins, and Alestes nurse 10 dorsal fins, 14 anal fins, 31 caudal fins, 7 pectoral fins and 6 ventral fins. The morphometric features of the two most abundant fish species are Citharinus citharius total length 300mm, standard length 231mm, head length 69mm, body length 101mm, body girth 176 mm, body weight 900mg. Alestes nurse total length 200, standard length 140mm, head length 60mm, body length 80mm, body girth120mm, body weight 400mg. The most abundant animal utilizing the basin was Ardea cinerea(D3 with 22.2% occurrence (D4 and this was followed by Caprini with 13.51%, and Varanus niloticus, 10.04%. The least abundant animals utilizing basin were Chephalophus rufilatus, and Erythrocebus patas, with 0.58% each of occurrence. Rev. Biol. Trop. 57 (1-2: 177-186. Epub

  7. fish species and size distribution and abundance in different areas

    African Journals Online (AJOL)

    Larger individuals dominated in deep waters recording a mode at 45.5 cm TL. ... as a result of trophic interactions with introduced species ... sea level. The climate is equatorial with two wet seasons, one between October and. December, the ...

  8. Sperm quality and cryopreservation of Brazilian freshwater fish species: a review.

    Science.gov (United States)

    Viveiros, A T M; Godinho, H P

    2009-03-01

    The Brazilian freshwater fish diversity is the richest in the world. Only 0.7% of all Brazilian species have had any aspect of their sperm biology addressed up to this date. The majority of the fish species described in this review migrate during the spawning season (a phenomenon known as piracema). Urbanization, pollution, hydroelectric dams and deforestation are some of the causes of stock depletion or even local extinction of some of these species. The knowledge concerning sperm quality and minimum sperm:egg ratio is important to maximize the use of males without reducing hatching rates. Furthermore, sperm cryopreservation and gene banking can guarantee the conservation of genetic diversity and development of adequate breeding programs of native fish species. In this review, we present and evaluate the existing information on Brazilian fish species that have been subject to sperm quality and cryopreservation studies. The following parameters were evaluated: volume of extractable sperm, sperm motility, sperm concentration, freezing media, freezing methods, and post-thaw sperm quality. Although the existing protocols yield relatively high post-thaw motility and fertilization rates, the use of cryopreserved sperm in routine hatchery production is still limited in Brazil.

  9. Trophodynamics and diet overlap of small pelagic fish species in the Bay of Biscay

    KAUST Repository

    Bachiller, E; Irigoien, Xabier

    2015-01-01

    Small pelagic fish are the link between planktonic production and higher trophic levels. Competition for resources may play a role in the population dynamics of species, some of them probably standing out from the others due to greater feeding success. It is therefore important to understand the trophic niche of species overlapping both spatially and temporally. In this study, we have investigated the diet, prey preference, trophic niche breadth and diet overlap of the 8 major small pelagic species (anchovy, sardine, sprat, Atlantic and Mediterranean horse mackerel, bogue, Atlantic mackerel and Atlantic chub mackerel) inhabiting the Bay of Biscay. Results indicate that all fish feed mainly on calanoid copepods, incorporating larger prey like euphausiids and decapods to complete their diet. Differences in ingested prey diversity seem to be more limited by the available zooplankton at sea than by a specific diet preference by fish species, resulting in an overall high diet overlap, especially within clupeids but also between clupeids and other (larger) predator species. Consumption estimations for different prey groups could therefore determine whether such a large diet overlap between small pelagic fish, together with spatial co-occurrence, results in competition or enhances the effects of intraguild predation, which is important in terms of an ecosystem approach to fisheries management.

  10. Trophodynamics and diet overlap of small pelagic fish species in the Bay of Biscay

    KAUST Repository

    Bachiller, E

    2015-08-27

    Small pelagic fish are the link between planktonic production and higher trophic levels. Competition for resources may play a role in the population dynamics of species, some of them probably standing out from the others due to greater feeding success. It is therefore important to understand the trophic niche of species overlapping both spatially and temporally. In this study, we have investigated the diet, prey preference, trophic niche breadth and diet overlap of the 8 major small pelagic species (anchovy, sardine, sprat, Atlantic and Mediterranean horse mackerel, bogue, Atlantic mackerel and Atlantic chub mackerel) inhabiting the Bay of Biscay. Results indicate that all fish feed mainly on calanoid copepods, incorporating larger prey like euphausiids and decapods to complete their diet. Differences in ingested prey diversity seem to be more limited by the available zooplankton at sea than by a specific diet preference by fish species, resulting in an overall high diet overlap, especially within clupeids but also between clupeids and other (larger) predator species. Consumption estimations for different prey groups could therefore determine whether such a large diet overlap between small pelagic fish, together with spatial co-occurrence, results in competition or enhances the effects of intraguild predation, which is important in terms of an ecosystem approach to fisheries management.

  11. Species differences in contaminants in fish on and adjacent to the Oak Ridge Reservation, Tennessee

    International Nuclear Information System (INIS)

    Burger, Joanna; Campbell, K.R.

    2004-01-01

    Risks to humans and other organisms from consuming fish have become a national concern in the USA. In this paper, we examine the concentrations of 137 Cs, arsenic, beryllium, cadmium, lead, mercury, and selenium in three species of fish from two river reaches adjacent to the US Department of Energy's Oak Ridge Reservation in Tennessee. We were interested in whether there were species and locational differences in radiocesium and metal concentrations and whether concentrations were sufficiently high to pose a potential health risk to humans or other receptors. Striped bass (Morone saxatilis) were significantly larger than white bass (M. chrysops), and crappie (Pomoxis spp.) were the smallest fish. Lead was significantly lower in striped bass, mercury was significantly higher in striped bass, and selenium was significantly higher in white bass compared to the other species. There were no other species differences in contaminants. White bass, the only species that was sufficiently abundant for a comparison, had significantly higher concentrations of cadmium, lead, and selenium in fillets from the Clinch River and significantly higher concentrations of mercury in fillets from Poplar Creek. The low concentrations of most contaminants in fish from the Clinch River do not appear to present a risk to humans or other consumers, although mercury concentrations in striped bass ranged as high as 0.79 ppm, well above the 0.5-ppm action level for human consumption of some US states

  12. Regional and Seasonal Differences in Species Composition and Trophic Groups for Tidepool Fishes of a Western Pacific Island – Taiwan

    Directory of Open Access Journals (Sweden)

    Colin K. C. Wen

    2018-03-01

    Full Text Available Spatial and temporal variations in the species composition of assemblages are common in many marine organisms, including fishes. Variations in the fish species composition of subtidal coral reefs have been well documented, however much less is known about such differences for intertidal fish assemblages. This is surprising, given that intertidal fishes are more vulnerable to terrestrial human disturbances. It is critical to evaluate the ecology and biology of intertidal fishes before they are severely impacted by coastal development, especially in developing countries such as those in the tropical western Pacific region where coastal development is rapidly increasing. In this study, we investigated the species composition, abundance, biomass and species number (richness for intertidal fish assemblages in subtropical (northern and tropical (southern Taiwan across four seasons by collecting fishes from tidepools using clove oil. We also examined the gut contents of collected fishes to identify their trophic functional groups in order to investigate regional and seasonal variations for different trophic groups. We found significant differences in the species composition of tidepool fish assemblages between subtropical and tropical Taiwan. Bathygobius fuscus, Abudefduf vaigiensis and Istiblennius dussumieri were dominant species in subtropical Taiwan, whereas Bathygobius coalitus, Abudefduf septemfasciatus and Istiblennius lineatus were dominant in tropical Taiwan. Other species such as Bathygobius cocosensis, Abudefduf sordidus and Istiblennius edentulus were common in both regions. For trophic groups, omnivores and detritivores had or showed trends towards higher species numbers and abundances in the subtropical region, whereas herbivores, planktivores and general carnivores had or showed trends towards higher species numbers and biomass in the tropical region. Overall, many intertidal fish species and trophic groups showed differences in

  13. EFFECTS OF FARMING SYSTEMS ON SPECIES COMPOSITION, NUTRIENT CONTENT AND DIGESTIBILTY OF FORAGES OF THE NATURAL PASTURE OF ASSOSA ZONE (WESTERN ETHIOPIA

    Directory of Open Access Journals (Sweden)

    Beyene Teklu

    2010-07-01

    Full Text Available Forage species of the natural pasture of Assosa Zone of Benshangule-Gumuz (Western Ethiopia were identified and their chemical composition and in vitro dry matter digestibility (IVDMD determined. Data were collected from two farming systems (shifting cultivation: SC and permanent farming system: PFS and two grazing types (communal grazing land: CGL, riverside grazing land: RSGL. 18 grasses, 2 legumes, sedge, 2 forbs and 17 trees/shrubs were identified from the natural pasture of both farming systems. Hyparrhenia rufa had significantly lower (P

  14. Biota monitoring under the Water Framework Directive: On tissue choice and fish species selection.

    Science.gov (United States)

    Fliedner, Annette; Rüdel, Heinz; Lohmann, Nina; Buchmeier, Georgia; Koschorreck, Jan

    2018-04-01

    The study addresses the topic of suitable matrices for chemical analysis in fish monitoring and discusses the effects of data normalization in the context of the European Water Framework Directive (WFD). Differences between species are considered by comparing three frequently monitored species of different trophic levels, i.e., chub (Squalius cephalus, n = 28), (bream, Abramis brama, n = 11), and perch (Perca fluviatilis, n = 19) sampled in the German Danube. The WFD priority substances dioxins, furans and dioxin-like polychlorinated biphenyls (PCDD/F + dl-PCB), polybrominated diphenyl ethers (PBDE), α-hexabromocyclododecane (α-HBCDD), hexachlorobenzene (HCB), mercury (Hg), and perfluorooctane sulfonic acid (PFOS) as well as non-dioxin-like (ndl)-PCB were analyzed separately in fillet and carcass and whole body concentrations were calculated. Hg was analyzed in individual fish fillets and carcasses, all other substances were determined in pool samples, which were compiled on the basis of fish size (3 chub pools, 1 bream pool, 2 perch pools). The data were normalized to 5% lipid weight (or 26% dry mass in the case of Hg and PFOS) for comparison between matrices and species. Hg concentrations were generally higher in fillet than in whole fish (mean whole fish-to-fillet ratio: 0.7) whereas all other substances were mostly higher in whole fish. In the case of lipophilic substances these differences leveled after lipid normalization. Significant correlations (p ≤ .05) were detected between Hg and fish weight and age. Hg concentrations varied least among younger fish. PCDD/F, dl-PCB, ndl-PCB, PBDE, α-HBCDD and HCB correlated significantly (p ≤ .05) with lipid concentrations. Fillet-to-whole fish conversion equations and/or conversion factors were derived for all substances except α-HCBDD. Although more data also for individual fish would be desirable the results are nevertheless a step on the way to translate fillet concentrations of priority

  15. The importance of live-feed traps - farming marine fish species

    DEFF Research Database (Denmark)

    Nielsen, Rasmus; Nielsen, Max; Abate, Tenaw Gedefaw

    2017-01-01

    This article analyses the challenges of different live-feed regimes for the rearing of marine finfish larvae and discusses the potential alternative live feeds to avert a future live-feed trap. Live feeds are indispensable for the successful rearing of larvae of most marine fish species. Brine...... shrimps (Artemia) and rotifers comprise the live feeds of choice in marine aquaculture today. However, their nutritional composition is deficient in especially essential fatty acids, and enrichment with fish oil is needed. Fish oil is considered a limited resource owing to its origin in fully exploited...... wild fish stocks. Moreover, fluctuations of the natural population of Artemia will, most likely, influence future availability and prices. This emphasizes the need for optimal exploitation of available live-feed resources and development of new sustainable alternatives, such as copepods. An array...

  16. Social learning of an associative foraging task in zebrafish

    Science.gov (United States)

    Zala, Sarah M.; Määttänen, Ilmari

    2013-05-01

    The zebrafish ( Danio rerio) is increasingly becoming an important model species for studies on the genetic and neural mechanisms controlling behaviour and cognition. Here, we utilized a conditioned place preference (CPP) paradigm to study social learning in zebrafish. We tested whether social interactions with conditioned demonstrators enhance the ability of focal naïve individuals to learn an associative foraging task. We found that the presence of conditioned demonstrators improved focal fish foraging behaviour through the process of social transmission, whereas the presence of inexperienced demonstrators interfered with the learning of the control focal fish. Our results indicate that zebrafish use social learning for finding food and that this CPP paradigm is an efficient assay to study social learning and memory in zebrafish.

  17. The influence of arbuscular mycorrhizae on root precision nutrient foraging of two pioneer plant species during early reclamation

    Science.gov (United States)

    Boldt-Burisch, Katja; Naeth, M. Anne

    2017-04-01

    On many post mining sites in the Lusatian Mining District (East Germany) soil heterogeneity consists of sandy soil with embedded clay-silt fragments. Those clays silt fragments might act as nutrient hotspots. Arbuscular mycorrhizal fungi in an infertile ecosystem could enhance a plant's ability to selectively forage for those nutrients and thus to improve plants nutrient supply. In our study we investigated whether silt-clay fragments within a sandy soil matrix induced preferential root growth of Lotus corniculatus and Calamagrostis epigeios, whether arbuscular mycorrhizae influenced root foraging patterns, and to what extent selective rooting in clay silt fragments influenced plant growth were addressed in this research. Soil types were sterile and non-sterile sandy soil and clay-silt fragments. Treatments were with and without arbuscular mycorrhizae, with and without soil solution, and soil solution and mycorrhizal inoculum combined. Root biomass, root density and intraradical fungal alkaline phosphatase activity and frequency were determined in fragments relative to sandy soil. Furthermore, temporal relationship of number of roots in fragments and plant height was assessed. Lotus corniculatus showed strong selective rooting into fragments especially with those plants treated with commercial cultivated arbuscular mycorrhizae; Calamagrostis epigeios did not. Without arbuscular mycorrhizae, L. corniculatus growth was significantly reduced and selective rooting did not occur. Selective rooting induced significant growth spurts of L. corniculatus. Roots in fragments had higher fungal alkaline phosphatase activity suggesting that mycorrhizal efficiency and related plants phosphorus supply is enhanced in roots in fragments. The application of cultivated arbuscular mycorrhizal fungi significantly and quickly influenced root foraging patterns, especially those of L. corniculatus, suggesting mycorrhizae may also enhance the ability of other plants to selectively forage

  18. Relationship between ecomorphology and trophic segregation in four closely related sympatric fish species (Teleostei, Sciaenidae).

    Science.gov (United States)

    Blasina, Gabriela; Molina, Juan; Lopez Cazorla, Andrea; Díaz de Astarloa, Juan

    This study explores the relationship between ecomorphology and trophic segregation in four closely related sympatric fish species (Teleostei, Sciaenidae) that are known to differ in their trophic habits. Only adult specimens were analyzed: 103 Cynoscion guatucupa, 77 Pogonias cromis, 61 Micropogonias furnieri, and 48 Menticirrhus americanus. The four species presented divergent ecomorphological traits related to swimming agility, prey spotting and capture, and the potential size of prey they were able to swallow. Results suggest that these sciaenid species can partition the food resources, even though they completely overlap in space. Differences in their ecomorphological traits appear to correlate closely with the diet and consequently could explain the trophic differentiation observed. Arguably, these ecomorphological differences play a significant role in the coexistence of the adults of these sympatric fish species. Copyright © 2016 Académie des sciences. Published by Elsevier SAS. All rights reserved.

  19. Evaluation of protected, threatened, and endangered fish species in Upper Bear Creek watershed

    International Nuclear Information System (INIS)

    Ryon, M.G.

    1998-07-01

    The East Bear Creek Site for the proposed centralized waste facility on the US Department of Energy's Oak Ridge Reservation was evaluated for potential rare, threatened or endangered (T and E) fish species in the six primary tributaries and the main stem of Bear Creek that are within or adjacent to the facility footprint. These tributaries and portion of Bear Creek comprise the upper Bear Creek watershed. One T and E fish species, the Tennessee dace (Phoxinus tennesseensis), was located in these streams. The Tennessee dace is listed by the State of Tennessee as being in need of management, and as such its habitat is afforded some protection. Surveys indicated that Tennessee dace occupy the northern tributaries NT-1, NT-4, and NT-5, as well as Bear Creek. Several specimens of the dace were gravid females, indicating that the streams may function as reproductive habitat for the species. The implications of impacts on the species are discussed and mitigation objectives are included

  20. Physiological and ecological factors influencing the radiocaesium contamination of fish species from Kiev reservoir

    Energy Technology Data Exchange (ETDEWEB)

    Koulikov, A.O. [A.N. Severtzov Institute of Evolutionary Morphology and Ecology of Animals, Russian Academy of Sciences, Moscow (Russian Federation)

    1995-11-23

    The monitoring of {sup 137}Cs contamination of fish from the northern part of the Kiev reservoir between 1987 and 1992 indicated systematic differences in the long-term average contamination levels of different species, which are closely related to their trophic levels. The average contamination of the predatory species: perch (Perca fluviatilis) and pike (Esox lucius) were roughly factors of 6.3 and 4.4 respectively, higher than those of the nonpredatory species: bream (Abramis brama), silver bream (Blicca bjoerkna) and rudd (Scardinius erythrophothalmus). For tench (Tinca tinca) and goldfish (Carassius sp.), this factor is 2. The solution of the caesium balance equation in fish obtained for equilibrium conditions, which is applicable to the long-term contamination, provides some explanations for these accumulation differences between the species with respect to influences by different ecological and physiological factors.

  1. Ecomorphology and resource use by dominant species of tropical estuarine juvenile fishes

    Directory of Open Access Journals (Sweden)

    André Luiz Machado Pessanha

    Full Text Available Eleven ecomorphological attributes and diet of seventeen juvenile fish species were examined to test the hypothesis that morphological patterns determine resource uses in estuarine habitats. Species were separated according to the apparatus to food capture and habitat use (benthic or pelagic in three different groups: (1 a group with depressed fish body, strong caudal peduncle and enlarged pectoral fins; (2 a second group laterally flattened with a wide protruding mouth, and (3 a third group strongly flattened with small pectorals fins. The following six trophic groups were organized based on prey categories: Zooplanktivores, Benthivores, Omnivores, Detritivores, Macrocarnivores and Insectivores. Significant results (PERMANOVA between ecomorphological indices and habitat and between ecomorphological indices and trophic groups were found. These data indicate that similarity of ecomorphological forms, which minimize the influence of environment and partitioning of food, would help facilitate the co-existence of these fish when they are abundant in this tropical estuary.

  2. Mercury Contamination in an Indicator Fish Species from Andean Amazonian Rivers Affected by Petroleum Extraction.

    Science.gov (United States)

    Webb, Jena; Coomes, Oliver T; Mainville, Nicolas; Mergler, Donna

    2015-09-01

    Elevated mercury (Hg) concentrations in fish from Amazonia have been associated with gold-mining, hydroelectric dams and deforestation but few studies consider the role of petroleum extraction. Hg levels were determined in fish samples collected in three river basins in Ecuador and Peru with contrasting petroleum exploitation and land-use characteristics. The non-migratory, piscivorous species, Hoplias malabaricus, was used as a bioindicator. The rate of Hg increase with body weight for this species was significantly higher on the Corrientes River, near the site of a recent oil spill, than on the other two rivers. In the absence of substantial deforestation and other anthropogenic sources in the Corrientes River basin, this finding suggests that oil contamination in Andean Amazonia may have a significant impact on Hg levels in fish.

  3. Thermal tolerance of some important fish species from Kali river, Karnataka

    International Nuclear Information System (INIS)

    Ayyappan, S.; Pal, A.K.; Das, T.; Bagchi, S.; Dalvi, R.

    2002-01-01

    Fish catch composition of Kadra reservoir at three different sampling points, viz., end of the hot water discharge channel of the nuclear power station i.e. Mixing Zone (Mz), 500 meters away from mixing zone at Hartuga village (Hv) and 15 km away from mixing zone at Virgae village (Vv) and thermal tolerance studies viz., Critical temperature maximum (CTmax), Critical temperature minimum (CTmin), oxygen consumption rates of different fish were determined for acclimation temperatures of 26, 31, 33 and 36 degC. The enzyme activities viz., Acetylcholine esterase (AchE), Malate dehydrogenase (MDH), Lactate dehydrogenase (LDH), Aspartate amino transferase (AST), Alanine amino transferase (ALT), Acid phosphatase (ACP) and Alkaline phosphatase (ALP) were studied in liver, gill, brain and muscle of Puntius ticto and Rasbora elanga at different acclimatized temperatures in a constant thermostatic aquarium. The fish catch composition varied at different sampling points. The predominant fish species identified from the three sampling points were Etroplus suratensis, Puntius sarana, Rasbora elanga, Chela argenta, Chela sardinella, Danio aequipinnatus at Mixing zone, Etroplus suratensis, Channa striatus, Channa micropeltes, Channa marulius, Ompok bimaculatus, Ompok malabarichus, Horabagrus brachysoma, Nemacheilus Sp., Mastacymbelus armastus at Hartuga village and Puntiu ticto, Labeo calbasu, Citrine cirrhosa, Ambasis dayi, Hemiramphus schlosseri, Periopthalmus limbatus at Virgae village. CT max varied from 38.5 degC to 42.6 degC in different fish species. Oxygen consumption rate of all species of fishes increased with increase in water temperature but magnitudes of increase was different in different species. The enzymatic activities increased concomitantly with increase in temperature up to 33 degC and followed a decrease at 36 degC. (author)

  4. Foraging behavior of three bee species in a natural mimicry system: female flowers which mimic male flowers in Ecballium elaterium (Cucurbitaceae).

    Science.gov (United States)

    Dukas, Reuyen

    1987-12-01

    The behavior of Apis mellifera and two species of solitary bees which forage in the flowers of monoecious Ecballium elaterium (L.) A. Rich (Cucurbitaceae) were compared. The female flowers of E. elaterium resemble male flowers visually but are nectarless, and their number is relatively smaller. Apis mellifera was found to discriminate between the two genders and to pay relatively fewer visits to female flowers (mean of 30% relative to male flowers) from the beginning of their activity in the morning. The time spent by honeybees in female flowers is very short compared to that spent in male flowers. It is surmised that the bees remember the differences between the flowers where they foraged on the previous days. In contrast, the two species of solitary bees Lasioglossum politum (Morawitz) (Halictidae) and Ceratina mandibularis Fiese (Anthophoridae) visit the female flowers with nearly equal frequencies at the beginning of each foraging day and stay longer in these flowers. Over the day there is a decline in the relative frequency of visits to female flowers and also in the mean time spent in them. The study shows that bees can collect rewards at high efficiency from the flowers of Ecballium elaterium because of their partial discrimination ability and the scarcity of the mimic flowers. It is suggested that the memory pattern of some solitary bees may be different from that of Apis mellifera. It seems that the limited memory and discrimination ability of bees can lead to a high frequency of visits to the mimic flowers during a long flowering season.

  5. Diel vertical migration of major fish-species in Lake Victoria, East Africa

    NARCIS (Netherlands)

    Goudswaard, P.C.; Wanink, J.H.; Witte, F.; Katunzi, E.F.B.; Berger, M.R.; Postma, D.J.

    2004-01-01

    Understanding of migration patterns is essential in the interpretation of hydro-acoustic stock assessment data of partly demersal partly pelagic fish stocks. In this paper we provide this kind of information for some species that were common in the Mwanza Gulf of Lake Victoria in the 1980s, before

  6. Diel vertical migration of major fish-species in Lake Victoria, East Africa.

    NARCIS (Netherlands)

    Goudswaard, KPC; Wanink, JH; Witte, F; Katunzi, EFB; Berger, MR; Postma, DJ

    2004-01-01

    Understanding of migration patterns is essential in the interpretation of hydro-acoustic stock assessment data of partly demersal partly pelagic fish stocks. In this paper we provide this kind of information for some species that were common in the Mwanza Gulf of Lake Victoria in the 1980s, before

  7. Short Note Flood effects on trophic linkages of selected fish species ...

    African Journals Online (AJOL)

    The St Lucia Estuary, a UNESCO World Heritage Site, has experienced prolonged mouth closure since 2002. Until recently it was hypersaline, but heavy rainfall between October 2010 and January 2011 led to a large overall decrease in salinity. A stable isotope study was conducted in March 2011 on selected fish species ...

  8. Divergent mating preferences and nuptial coloration in sibling species of cichlid fish

    NARCIS (Netherlands)

    Sluijs, Inke van der

    2008-01-01

    Mate choice by female cichlid fish from Lake Victoria plays an important role in speciation and the maintenance of species. Females are expected to select against males that are intermediate in their phenotype during the process of speciation driven by sexual selection. To test this, we hybridized

  9. 78 FR 24382 - Endangered and Threatened Species; Take of Anadromous Fish

    Science.gov (United States)

    2013-04-25

    ... design forest management activities (e.g., timber sales, grazing plans, road building) in such a way as to conserve listed species. The USFS does not intend to kill any of the listed fish being captured... projects. The researchers do not propose to kill any of the listed salmonids being captured, but a small...

  10. The finfish species caught with various fishing gear in Odi River ...

    African Journals Online (AJOL)

    The finfish species caught with various fishing gear in Odi River was studied in the Kolokuma/Opokuma axis of River Nun for six months (November – December 2011 and January, 2012 for dry season and May, June and July 2012 for wet season) to enhance management of its and similar water bodies fishery. Drift gillnet ...

  11. Analysing environmental and fishing effects on a short-lived species ...

    African Journals Online (AJOL)

    Short-lived species are extremely dependent on the seasonal and interannual variability of environmental conditions, and determining their stock status is often difficult. This study investigates the effects of environmental variability and fishing pressure on the stock of octopus Octopus vulgaris in Senegalese waters over a ...

  12. 76 FR 72678 - Atlantic Highly Migratory Species; Exempted Fishing, Scientific Research, Display, and Chartering...

    Science.gov (United States)

    2011-11-25

    ... require scientists to report their activities associated with these tags. Examples of research conducted... stock assessments. The public display and scientific research quotas for sandbar sharks are now limited... Highly Migratory Species; Exempted Fishing, Scientific Research, Display, and Chartering Permits; Letters...

  13. Genetic characterization of fin fish species from the Warri River at ...

    African Journals Online (AJOL)

    SAM

    2014-07-02

    Jul 2, 2014 ... Genetic characterization of fin fish species from the. Warri River at Ubeji, Niger Delta, Nigeria. Asagbra ..... Prochilodus lineatus, Salminus brasiliensis and Steindachneridion scripta) from Uruguay River basin. Brazilian Archives Biol. Tech. 49(4):589-598. Saad YM, Shaden-Hanafi M, Essa MA, Guerges AA ...

  14. 78 FR 13864 - Atlantic Highly Migratory Species; Exempted Fishing, Scientific Research, Display, and Chartering...

    Science.gov (United States)

    2013-03-01

    ... Highly Migratory Species; Exempted Fishing, Scientific Research, Display, and Chartering Permits; Letters... Permits (EFPs), Scientific Research Permits (SRPs), Display Permits, Letters of Acknowledgment (LOAs), and... scientific research, the acquisition of information and data, the enhancement of safety at sea, the purpose...

  15. Investigation of sensory profiles and hedonic drivers of emerging aquaculture fish species.

    Science.gov (United States)

    Alexi, Niki; Byrne, Derek V; Nanou, Evangelia; Grigorakis, Kriton

    2018-02-01

    The aquaculture sector needs to increase the diversity fish species and their processed products to cover rising consumer demands. Candidates for this diversification have been identified to be meagre, greater amberjack, pikeperch and wreckfish. Yet scientific knowledge on their sensory profiles and consumer hedonic responses is scarce. The aim of the current study was to investigate these aspects, since they are essential for product development and market targeting. Species exhibited different sensory profiles with the exception of the odor/flavor profiles of meagre and greater amberjack, which were similar. Texture was more important than odor/flavor in explaining interspecies differences. Yet the hedonic responses were equally related to texture and odor/flavor. None of the species received negative hedonic scores. Both positive and negative hedonic drivers were identified within the odor/flavor and texture modalities. The distinct profiles of meagre, greater amberjack, pikeperch and wreckfish make these fish species valuable first materials for new product development and for covering markets with different sensory preferences. Differences in fish texture are more easily perceivable, yet small variations in fish odor/flavor can have a great impact on consumers' hedonic responses. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  16. 76 FR 31590 - Endangered and Threatened Species; Take of Anadromous Fish

    Science.gov (United States)

    2011-06-01

    ... online at: https://apps.nmfs.noaa.gov/preview/preview_open_for_comment.cfm . These documents are also... to the disadvantage of the listed species which are the subject of the permits; and (3) are... included in the annual California Department of Fish and Game research program under the ESA 4(d) rule for...

  17. 77 FR 24469 - Endangered and Threatened Species; Take of Anadromous Fish

    Science.gov (United States)

    2012-04-24

    ... be viewed online at: https://apps.nmfs.noaa.gov/preview/preview_open_for_comment.cfm . These... operate to the disadvantage of the listed species which are the subject of the permits; and (3) are... Fisheries, NMFS. Applications Received Permit 14808 The California Department of Fish and Game (CDFG) is...

  18. Cooking process evaluation on micronutrient and total mercury content in fish species in Manaus, Brazil

    International Nuclear Information System (INIS)

    Farias, Luciana; Favaro, Deborah I.T.; Vaconcellos, Marina B.A.

    2007-01-01

    This study evaluated different cooking processes (roasted, cooked and fried) on micronutrient (Ca, Fe, K, Na, Se and Zn) and total Hg content in fish species most consumed by Manaus residents and surrounding communities. Twelve different fresh water fish species were purchased at the central receiving market (CEASA) in Manaus and prepared at the INPA Food and Nutrition Laboratory. In total 64 fish samples were analysed. Analytical determinations were performed by Neutron Activation Analysis Technique (NAA) for micronutrients and Atomic Absorption Spectrometry (CV AAS) for total Hg. All analytical methods were developed and validated for precision and accuracy by means of reference material analyses with certified values for the elements determined. The concentration variation of the analyzed elements was: Hg (2392 to 19 μ kg -1 ); K (19187 to 1185 mg kg -1 ); Ca (14590 to 994 mg kg -1 ); Na (18386 to 12850 mg kg -1 ); Fe (5580 to 4 mg kg -1 ); Se (5249 to 129 μg kg -1 ) and Zn (684 to 15 mg kg -1 ). The effect of the different cooking processes on the variation of micronutrient composition was quite significant. On the other hand Hg composition variation seems to be more related to fish species rather than the cooking process itself. As was expected, predatory species presented higher Hg and Se levels. (author)

  19. The South American freshwater fish Prochilodus lineatus (Actinopterygii: Characiformes: Prochilodontidae): new species in Vietnamese aquaculture

    Czech Academy of Sciences Publication Activity Database

    Kalous, L.; Bui, A.T.; Petrtýl, M.; Bohlen, Jörg; Chaloupková, P.

    2012-01-01

    Roč. 43, č. 6 (2012), 955-958 ISSN 1355-557X Grant - others:MZe(CZ) 29/MZe/B/08-10 Institutional research plan: CEZ:AV0Z50450515 Keywords : exotic species * aquaculture * Prochilodus lineatus Subject RIV: GL - Fishing Impact factor: 1.422, year: 2012

  20. Amount and qualities of carotenoids in fillets of fish species fed with ...

    African Journals Online (AJOL)

    Using column (CC), thin- layer (TLC) and high- performance liquid chromatography (HPLC), carotenoid content was examined in the fillets (muscles with skin) of 16 fish species from the fisheries of West African Coast. 15 carotenoids, including 6 ketocarotenoids (4'- hydroxyechinenone, canthaxanthin, phoenicopterone, ...

  1. Fish Species Observed in the Hawaii Exclusive Economic Zone from the 1750s through 2003 (NODC Accession 0001486)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A list of Hawaiian fish species was created from contemporary and historical documents dating back to 1758. For each species, the name of the person who described...

  2. Freshwater fishes in Greek lakes: Species richness and body size patterns

    Directory of Open Access Journals (Sweden)

    Anthi Oikonomou

    2015-11-01

    Full Text Available Freshwater ecosystems are widely recognised as hotspots of biodiversity and endemism; thus they are of great value for conservation biogeography. Amongst the taxa found in freshwater ecosystems, fish are the ideal biological model for testing biogeographical patterns and have often been used in large-scale ecological and biogeographical analyses. Lakes of Greece provide a unique opportunity to test biogeographical theories, however, biogeographical studies in Greece at broader, regional, scales, based on the distribution of freshwater species, species richness and endemism, are scarce. The aim of the current study is to test the effect of key environmental factors and spatial variables on species richness of lacustrine fishes and to test their effect on species’ size distributions. We assembled datasets of species richness and body size and environmental (predictor factors for 13 Greek lakes. Model selection procedures revealed that fish species richness increased with ecosystem area and decreased with altitude. In addition, our results showed that latitude per se is a good predictor of body size. Indeed, the mean size of lacustrine communities in the northern and southern lake ecosystems differed significantly. These patterns reflect the biogeographical history of these areas and highlight the crucial role connectivity plays in communities’ species composition.

  3. Avian predator buffers against variability in marine habitats with flexible foraging behavior

    Science.gov (United States)

    Schoen, Sarah K.; Piatt, John F.; Arimitsu, Mayumi L.; Heflin, Brielle; Madison, Erica N.; Drew, Gary S.; Renner, Martin; Rojek, Nora A.; Douglas, David C.; DeGange, Anthony R.

    2018-01-01

    How well seabirds compensate for variability in prey abundance and composition near their breeding colonies influences their distribution and reproductive success. We used tufted puffins (Fratercula cirrhata) as forage fish samplers to study marine food webs from the western Aleutian Islands (53°N, 173°E) to Kodiak Island (57°N, 153°W), Alaska, during August 2012–2014. Around each colony we obtained data on: environmental characteristics (sea surface temperature and salinity, seafloor depth and slope, tidal range, and chlorophyll-a), relative forage fish biomass (hydroacoustic backscatter), and seabird community composition and density at-sea. On colonies, we collected puffin chick-meals to characterize forage communities and determine meal energy density, and measured chicks to obtain a body condition index. There were distinct environmental gradients from west to east, and environmental variables differed by ecoregions: the (1) Western-Central Aleutians, (2) Eastern Aleutians, and, (3) Alaska Peninsula. Forage fish biomass, species richness, and community composition all differed markedly between ecoregions. Forage biomass was strongly correlated with environmental gradients, and environmental gradients and forage biomass accounted for ~ 50% of the variability in at-sea density of tufted puffins and all seabird taxa combined. Despite the local and regional variability in marine environments and forage, the mean biomass of prey delivered to puffin chicks did not differ significantly between ecoregions, nor did chick condition or puffin density at-sea. We conclude that puffins can adjust their foraging behavior to produce healthy chicks across a wide range of environmental conditions. This extraordinary flexibility enables their overall success and wide distribution across the North Pacific Ocean.

  4. Human Health Risk from Metals in Fish from Saudi Arabia: Consumption Patterns for Some Species Exceed Allowable Limits

    KAUST Repository

    Burger, Joanna

    2014-10-06

    ABSTRACT: Fish are a healthful source of protein, but contaminants in some fish pose a risk. While there are multiple risk assessments from Europe and North America, there are far fewer for other parts of the world. We examined the risks from mercury, arsenic, lead, and other metals in fish consumed by people in Jeddah area, Saudi Arabia, using site-specific data on consumption patterns and metal levels in fish. The U.S. Environmental Protection Agency\\'s Hazard Quotient (HQ) and cumulative Hazard Index (HI) for non-cancer endpoints and Carcinogenic Index for cancer were used to determine the health risk based on fish consumption rates. Of the 13 fish species examined, HQ was greater than 1 (indicating elevated risk) in two species for arsenic, and seven species for methylmercury. The cumulative HI for all metals was above 1 for all but three species of fish at the mean consumption rates. Generally, fish species with HI above 1 for one sampling location, had HI above 1 for all sampling locations. The implications of these findings are discussed in the light of strategies for reducing risk from fish consumption while encouraging dietary intakes of fish with low mercury and arsenic levels.

  5. Primary versus secondary drivers of foraging activity in sandeel schools (Ammodytes tobianus)

    DEFF Research Database (Denmark)

    Deurs, Mikael van; Behrens, Jane; Warnar, Thomas

    2011-01-01

    to fishery biologists and has consequences for a wide range of predators ranging from birds and mammals to commercially important species. However, experimental studies that shed light on the primary drivers of foraging activity in fish are rare. In the present study, whole schools of sandeel (A. tobianus......The commercially and ecologically valuable sandeel (Ammodytes ssp.) make distinct vertical shifts between an inactive stage, during which they seek refuge in the sand, and a pelagic schooling stage, during which they forage. This characteristic discontinuous foraging pattern constitutes a challenge......) were caught in August in east Denmark (65A degrees 02'30N; 12A degrees 37'00E) and kept in large tanks in the laboratory. It was found that the amount of food ingested and memory of past days feeding history are primary drivers of foraging activity at the level of the entire school, whereas external...

  6. Concentration of arsenic in water, sediments and fish species from naturally contaminated rivers.

    Science.gov (United States)

    Rosso, Juan José; Schenone, Nahuel F; Pérez Carrera, Alejo; Fernández Cirelli, Alicia

    2013-04-01

    Arsenic (As) may occur in surface freshwater ecosystems as a consequence of both natural contamination and anthropogenic activities. In this paper, As concentrations in muscle samples of 10 fish species, sediments and surface water from three naturally contaminated rivers in a central region of Argentina are reported. The study area is one of the largest regions in the world with high As concentrations in groundwater. However, information of As in freshwater ecosystems and associated biota is scarce. An extensive spatial variability of As concentrations in water and sediments of sampled ecosystems was observed. Geochemical indices indicated that sediments ranged from mostly unpolluted to strongly polluted. The concentration of As in sediments averaged 6.58 μg/g ranging from 0.23 to 59.53 μg/g. Arsenic in sediments barely followed (r = 0.361; p = 0.118) the level of contamination of water. All rivers showed high concentrations of As in surface waters, ranging from 55 to 195 μg/L. The average concentration of As in fish was 1.76 μg/g. The level of contamination with As differed significantly between species. Moreover, the level of bioaccumulation of As in fish species related to the concentration of As in water and sediments also differed between species. Whilst some fish species seemed to be able to regulate the uptake of this metalloid, the concentration of As in the large catfish Rhamdia quelen mostly followed the concentration of As in abiotic compartments. The erratic pattern of As concentrations in fish and sediments regardless of the invariable high levels in surface waters suggests the existence of complex biogeochemical processes behind the distribution patterns of As in these naturally contaminated ecosystems.

  7. Pollution Problem in River Kabul: Accumulation Estimates of Heavy Metals in Native Fish Species.

    Science.gov (United States)

    Ahmad, Habib; Yousafzai, Ali Muhammad; Siraj, Muhammad; Ahmad, Rashid; Ahmad, Israr; Nadeem, Muhammad Shahid; Ahmad, Waqar; Akbar, Nazia; Muhammad, Khushi

    2015-01-01

    The contamination of aquatic systems with heavy metals is affecting the fish population and hence results in a decline of productivity rate. River Kabul is a transcountry river originating at Paghman province in Afghanistan and inters in Khyber Pakhtunkhwa province of Pakistan and it is the major source of irrigation and more than 54 fish species have been reported in the river. Present study aimed at the estimation of heavy metals load in the fish living in River Kabul. Heavy metals including chromium, nickel, copper, zinc, cadmium, and lead were determined through atomic absorption spectrophotometer after tissue digestion by adopting standard procedures. Concentrations of these metals were recorded in muscles and liver of five native fish species, namely, Wallago attu, Aorichthys seenghala, Cyprinus carpio, Labeo dyocheilus, and Ompok bimaculatus. The concentrations of chromium, nickel, copper, zinc, and lead were higher in both of the tissues, whereas the concentration of cadmium was comparatively low. However, the concentration of metals was exceeding the RDA (Recommended Dietary Allowance of USA) limits. Hence, continuous fish consumption may create health problems for the consumers. The results of the present study are alarming and suggest implementing environmental laws and initiation of a biomonitoring program of the river.

  8. Risk-benefit evaluation of fish from Chinese markets: Nutrients and contaminants in 24 fish species from five big cities and related assessment for human health

    Energy Technology Data Exchange (ETDEWEB)

    Du, Zhen-Yu, E-mail: zdu@nifes.no [National Institute of Nutrition and Seafood Research (NIFES), N-5817 Bergen (Norway); Zhang, Jian [National Institute of Nutrition and Seafood Research (NIFES), N-5817 Bergen (Norway); Institute of Nutrition and Food Safety, Chinese Center for Disease Control and Prevention, Beijing, 100050 (China); Department of Biomedicine, University of Bergen (Norway); Wang, Chunrong; Li, Lixiang; Man, Qingqing [Institute of Nutrition and Food Safety, Chinese Center for Disease Control and Prevention, Beijing, 100050 (China); Lundebye, Anne-Katrine; Froyland, Livar [National Institute of Nutrition and Seafood Research (NIFES), N-5817 Bergen (Norway)

    2012-02-01

    The risks and benefits of fish from markets in Chinese cities have not previously been fully evaluated. In the present study, 24 common fish species with more than 400 individual samples were collected from markets from five big Chinese cities in 2007. The main nutrients and contaminants were measured and the risk-benefit was evaluated based on recommended nutrient intakes and risk level criteria set by relevant authorities. The comprehensive effects of nutrients and contaminants in marine oily fish were also evaluated using the data of two related human dietary intervention trials performed in dyslipidemic Chinese men and women in 2008 and 2010, respectively. The results showed that concentrations of contaminants analyzed including DDT, PCB{sub 7}, arsenic and cadmium were much lower than their corresponding maximum limits with the exception of the mercury concentration in common carp. Concentrations of POPs and n-3 LCPUFA, mainly EPA and DHA, were positively associated with the lipid content of the fish. With a daily intake of 80-100 g marine oily fish, the persistent organic pollutants in fish would not counteract the beneficial effects of n-3 LCPUFA in reducing cardiovascular disease (CVD) risk markers. Marine oily fish provided more effective protection against CVD than lean fish, particularly for the dyslipidemic populations. The risk-benefit assessment based on the present daily aquatic product intake in Chinese urban residents (44.9 and 62.3 g for the average values for all cities and big cities, respectively) indicated that fish, particularly marine oily fish, can be regularly consumed to achieve optimal nutritional benefits from n-3 LCPUFA, without causing significant contaminant-related health risks. However, the potential health threat from contaminants in fish should still be emphasized for the populations consuming large quantities of fish, particularly wild fish. - Highlights: Black-Right-Pointing-Pointer We collected 24 fish species with more than

  9. Risk–benefit evaluation of fish from Chinese markets: Nutrients and contaminants in 24 fish species from five big cities and related assessment for human health

    International Nuclear Information System (INIS)

    Du, Zhen-Yu; Zhang, Jian; Wang, Chunrong; Li, Lixiang; Man, Qingqing; Lundebye, Anne-Katrine; Frøyland, Livar

    2012-01-01

    The risks and benefits of fish from markets in Chinese cities have not previously been fully evaluated. In the present study, 24 common fish species with more than 400 individual samples were collected from markets from five big Chinese cities in 2007. The main nutrients and contaminants were measured and the risk–benefit was evaluated based on recommended nutrient intakes and risk level criteria set by relevant authorities. The comprehensive effects of nutrients and contaminants in marine oily fish were also evaluated using the data of two related human dietary intervention trials performed in dyslipidemic Chinese men and women in 2008 and 2010, respectively. The results showed that concentrations of contaminants analyzed including DDT, PCB 7 , arsenic and cadmium were much lower than their corresponding maximum limits with the exception of the mercury concentration in common carp. Concentrations of POPs and n-3 LCPUFA, mainly EPA and DHA, were positively associated with the lipid content of the fish. With a daily intake of 80–100 g marine oily fish, the persistent organic pollutants in fish would not counteract the beneficial effects of n-3 LCPUFA in reducing cardiovascular disease (CVD) risk markers. Marine oily fish provided more effective protection against CVD than lean fish, particularly for the dyslipidemic populations. The risk–benefit assessment based on the present daily aquatic product intake in Chinese urban residents (44.9 and 62.3 g for the average values for all cities and big cities, respectively) indicated that fish, particularly marine oily fish, can be regularly consumed to achieve optimal nutritional benefits from n-3 LCPUFA, without causing significant contaminant-related health risks. However, the potential health threat from contaminants in fish should still be emphasized for the populations consuming large quantities of fish, particularly wild fish. - Highlights: ► We collected 24 fish species with more than 400 individual samples

  10. Occurrence and Intensity of Anisakid Nematode Larvae in Some Commercially Important Fish Species in Persian Gulf

    Directory of Open Access Journals (Sweden)

    Maryam DADAR

    2016-10-01

    Full Text Available Background: Anisakid nematodes are common parasites of fish, mammals, fish-eating birds, and reptiles with a worldwide distribution, causing diseases in human, fish and important economic losses.Methods: A preliminary epidemiological study was carried out on Anisakid nematodes larvae in some commercially important fish species to evaluate the anisakid nematode larvae from greater lizardfish, (Saurida tumbil, Japanese thread fin bream (Nemipterus japonicus, crocodile longtom (Tylosurus crocodilus crocodiles and longfin trevally (Carangoides armatus from the Persian Gulf of Iran.Result: The collected larvae were identified mainly as the third larval stage (L3 of Hysterothylacium larval type A, B and C, Anisakis sp., Raphidascaris sp., Pseudoterranova sp. and Philometra sp. (Nematoda: Philometridae. The prevalence of Anisakid larvae infection of examined fishes was 97.2% in N. japonicus, 90.3% in S. tumbil, 20.5% in crocodile longtom and 5.5% in longfin trevally. Anisakis type III for the first time was different from Anisakis type I and Anisakis type II.Discussion: Zoonotic anisakids by high prevalence in edible fish could be a health hazard for people. So health practices should be considered in these areas.

  11. Nutritional evaluation of commercially important fish species of Lakshadweep archipelago, India.

    Directory of Open Access Journals (Sweden)

    Kottila Veettil Dhaneesh

    Full Text Available Estimation of nutrition profile of edible fishes is essential and thus a bio-monitoring study was carried out to find out the nutritional composition of commonly available fishes in Agatti Island water of Lakshadweep Sea. Protein, carbohydrate, lipid, ash, vitamin, amino acid and fatty acid composition in the muscle of ten edible fish species were studied. Proximate analysis revealed that the protein, carbohydrate, lipid and ash contents were high in Thunnus albacares (13.69%, Parupeneus bifasciatus (6.12%, Hyporhamphus dussumieri (6.97% and T. albacares (1.65%, respectively. Major amino acids were lysine, leucine and methionine, registering 2.84-4.56%, 2.67-4.18% and 2.64-3.91%, respectively. Fatty acid compositions ranged from 31.63% to 38.97% saturated (SFA, 21.99-26.30% monounsaturated (MUFAs, 30.32-35.11% polyunsaturated acids (PUFAs and 2.86-7.79% branched fatty acids of the total fatty acids. The ω-3 and ω-6 PUFAs were ranged 13.05-21.14% and 6.88-9.82% of the total fatty acids, respectively. Hence, the fishes of Lakshadweep Sea are highly recommended for consumption, since these fishes are highly enriched with nutrition. The results can be used as a baseline data for comparing the various nutritional profiles of fishes in future.

  12. Petroleum hydrocarbon concentrations in ten commercial fish species along Tamilnadu coast, Bay of Bengal, India.

    Science.gov (United States)

    Veerasingam, S; Venkatachalapathy, R; Raja, P; Sudhakar, S; Rajeswari, V; Asanulla, R Mohamed; Mohan, R; Sutharsan, P

    2011-05-01

    The aim of the present study was to evaluate the distribution of petroleum hydrocarbons in ten commercial fish species and water samples in three estuaries along Tamilnadu coast, Bay of Bengal, India. Fish and water samples collected from Tamilnadu coast, India, were extracted and analyzed for petroleum hydrocarbons by ultraviolet fluorescence (UVF) spectroscopy. The petroleum hydrocarbon concentration (PHC) in coastal waters and fish species varied between 2.28 and 14.02 μg/l and 0.52 and 2.05 μg/g, respectively. The highest PHC concentration was obtained in Uppanar estuarine waters (14.02 ± 0.83) and the lowest was observed in Vellar estuarine waters (2.28 ± 0.25). Among the ten fish species, Sardinella longiceps have high PHC concentration from all the locations. This study suggests that S. longiceps can be used as a good biological indicator for petroleum hydrocarbon pollution in water. The concentration of petroleum hydrocarbons in coastal waters along Tamilnadu coast is markedly higher than that in the background, but there is no evidence for its increase in fish of this region. From a public health point, petroleum hydrocarbon residue levels in all fish samples analyzed in this study are considerably lower than the hazardous levels. At present, as Tamilnadu coastal area is in a rapid development stage of new harbour, chemical industries, power plants, oil exploration and other large-scale industries, further assessment of petroleum hydrocarbons and the various hydrodynamic conditions acting in the region are to be studied in detail and continuous pollution monitoring studies should be conducted for improving the aquatic environment. The results will also be useful for pollution monitoring program along the coastal region and also to check the levels of petroleum hydrocarbons.

  13. Assessing historical fish community composition using surveys, historical collection data, and species distribution models.

    Science.gov (United States)

    Labay, Ben; Cohen, Adam E; Sissel, Blake; Hendrickson, Dean A; Martin, F Douglas; Sarkar, Sahotra

    2011-01-01

    Accurate establishment of baseline conditions is critical to successful management and habitat restoration. We demonstrate the ability to robustly estimate historical fish community composition and assess the current status of the urbanized Barton Creek watershed in central Texas, U.S.A. Fish species were surveyed in 2008 and the resulting data compared to three sources of fish occurrence information: (i) historical records from a museum specimen database and literature searches; (ii) a nearly identical survey conducted 15 years earlier; and (iii) a modeled historical community constructed with species distribution models (SDMs). This holistic approach, and especially the application of SDMs, allowed us to discover that the fish community in Barton Creek was more diverse than the historical data and survey methods alone indicated. Sixteen native species with high modeled probability of occurrence within the watershed were not found in the 2008 survey, seven of these were not found in either survey or in any of the historical collection records. Our approach allowed us to more rigorously establish the true baseline for the pre-development fish fauna and then to more accurately assess trends and develop hypotheses regarding factors driving current fish community composition to better inform management decisions and future restoration efforts. Smaller, urbanized freshwater systems, like Barton Creek, typically have a relatively poor historical biodiversity inventory coupled with long histories of alteration, and thus there is a propensity for land managers and researchers to apply inaccurate baseline standards. Our methods provide a way around that limitation by using SDMs derived from larger and richer biodiversity databases of a broader geographic scope. Broadly applied, we propose that this technique has potential to overcome limitations of popular bioassessment metrics (e.g., IBI) to become a versatile and robust management tool for determining status of

  14. Metal concentrations in demersal fish species from Santa Maria Bay, Baja California Sur, Mexico (Pacific coast).

    Science.gov (United States)

    Jonathan, M P; Aurioles-Gamboa, David; Villegas, Lorena Elizabeth Campos; Bohórquez-Herrera, Jimena; Hernández-Camacho, Claudia J; Sujitha, S B

    2015-10-15

    Concentrations of 11 trace metals (Fe, Mn, Cr, Cu, Ni, Co, Pb, Zn, Cd, As, Hg) in 40 fish species from Santa Maria Bay, Baja California Sur, Mexico, the strategically important area for marine mammals and organisms were analyzed. Based on their concentrations the ranking of metals Fe>Zn>Ni>Cr>Mn>Pb>Cu>Co>As>Cd>Hg suggests that organism size, metabolism and feeding habits are correlated with metal concentrations. Local geological formations affect the concentrations of different metals in the aquatic environment and are subsequently transferred to fishes. The correlation analysis suggests that metabolism and nurturing habits impact the concentration of metals. Concentrations of Fe and Mn appear to be influenced by scavenging and absorption processes, which vary by species. The considerable variability in the metal concentrations obtained in different species underscores the importance of regular monitoring. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. Comparative study of infection with Tetrahymena of different ornamental fish species

    DEFF Research Database (Denmark)

    Sharon, G.; Leibowitz, M. Pimenta; Chettri, Jiwan Kumar

    2014-01-01

    different super orders. The species examined were platy (Xiphophorus), molly (Poecilia sphenops) and angelfish (Pterophyllum scalare) of the Acanthopterygii super order (which also includes guppies) and goldfish (Carassius auratus auratus) and koi carp (Cyprinus carpio) of the Ostariophysi super order....... These two super orders are phylogenetically distant from each other. Infection with Tetrahymena resulted in parasite invasion of internal organs, skin and muscle in all fish species. A relatively strong inflammatory response was observed in infected goldfish and koi, with negligible response in fish species...... of the Acanthopterygii super order. Guppies were the most susceptible to Tetrahymena infection, exhibiting a mortality rate of 87% and 100% in two separate experiments. A high mortality rate was also observed in platy (77%), while that of molly and angelfish was significantly lower (23% and 33%, respectively). Goldfish...

  16. Biology and early development of eight fish species from the Alligator Rivers Region

    International Nuclear Information System (INIS)

    Ivantsoff, W.; Crowley, L.E.L.M.; Howe, E.; Semple, G.

    1988-01-01

    The following fish were studied: Melanotaenia nigrans, Melanotaenia splendida australis, Melanotaenia splendida inornata, Pseudomugil gertrudae, Pseudomugil tenellus, Craterocephalus nov. sp., Craterocephalus stercusmuscarum stercusmuscarum, and Ambassis macleavi. Coloration, other specific attributes, sexual dichromatism and dimorphism were recorded whenever possible so that the sexes could be easily recognised. Mating and other behaviour patterns were noted to facilitate recognition of breeding pairs. Spawning patterns and occurrence of cannibalism were recorded, as was the effect of the presence of more than one breeding pair in a tank. Egg numbers at each spawning were recorded and the main breeding season for each of the species was determined. No single stimulus to spawning could be determined. Spawning appeared to be sporadic but continuous throughout the year, with a peak during late spring/early summer. Detailed records of embryonic development were kept for all species except Ambassis macleayi. Time of development to hatching, at constant temperature, was recorded. Larval development of rainbow-fishes was recorded in detail and times to particular developmental stages noted and compared. For other species, the times to particular developmental stages were recorded and representative larval stages described and drawn. General recommendations are made in regard to the requirements to breed and maintain fish, the numbers that can be produced for further study and the constraints that may be present when working with selected fish. 46 refs., 18 figs., 16 tabs

  17. Metal contents in common edible fish species and evaluation of potential health risks to consumers

    Directory of Open Access Journals (Sweden)

    Naglaa Farag Soliman

    2015-12-01

    Full Text Available Objective: To conduct a health risk assessment of some heavy metals attributed to consumption of common edible fish species available for consumers. Methods: Concentrations of Cd, Cr, Cu, Fe, Mn, Pb and Zn were determined in muscles, gills, livers, bones and skins of six common edible fish species, namely Oreochromis niloticus, Mugil cephalus, Sardinella aurita, Mullus barbatus, Boops boops, Pagrus pagrus. Concentrations of heavy metals were determined by atomic absorption spectrophotometer and expressed as µg/g of wet tissue. Results: Results showed that iron and zinc were the most abundant among all fish tissues under investigation. The data obtained in the present work were compared well with the counterpart data reported internationally. The estimated values of all metals in muscles of fish in this study were below the permissible limits. Moreover, the potential health risks of metals to human via consumption of seafood were assessed by estimating daily intake and target heath quotient. Generally, risk values for the measured metals do not pose unacceptable risks at mean ingestion rate for muscles. Conclusions: It can be concluded that the investigated metals in edible parts of the examined species have no health problems for consumers.

  18. Biology and early development of eight fish species from the Alligator Rivers Region. Technical memorandum 22

    Energy Technology Data Exchange (ETDEWEB)

    Ivantsoff, W; Crowley, L E.L.M.; Howe, E; Semple, G

    1988-01-01

    The following fish were studied: Melanotaenia nigrans, Melanotaenia splendida australis, Melanotaenia splendida inornata, Pseudomugil gertrudae, Pseudomugil tenellus, Craterocephalus nov. sp., Craterocephalus stercusmuscarum stercusmuscarum, and Ambassis macleavi. Coloration, other specific attributes, sexual dichromatism and dimorphism were recorded whenever possible so that the sexes could be easily recognised. Mating and other behaviour patterns were noted to facilitate recognition of breeding pairs. Spawning patterns and occurrence of cannibalism were recorded, as was the effect of the presence of more than one breeding pair in a tank. Egg numbers at each spawning were recorded and the main breeding season for each of the species was determined. No single stimulus to spawning could be determined. Spawning appeared to be sporadic but continuous throughout the year, with a peak during late spring/early summer. Detailed records of embryonic development were kept for all species except Ambassis macleayi. Time of development to hatching, at constant temperature, was recorded. Larval development of rainbow-fishes was recorded in detail and times to particular developmental stages noted and compared. For other species, the times to particular developmental stages were recorded and representative larval stages described and drawn. General recommendations are made in regard to the requirements to breed and maintain fish, the numbers that can be produced for further study and the constraints that may be present when working with selected fish. 46 refs., 18 figs., 16 tabs.

  19. Agronomic and forage characteristics of Guazuma ulmifolia Lam.

    OpenAIRE

    Manríquez-Mendoza, Leonor Yalid; López-Ortíz, Silvia; Pérez-Hernández, Ponciano; Ortega- Jiménez, Eusebio; López-Tecpoyotl, Zenón Gerardo; Villarruel-Fuentes, Manuel

    2011-01-01

    Native trees are an important source of forage for livestock, particularly in regions having prolonged dry periods. Some tree species have fast growth rates, good nutritional quality, and the ability to produce forage during dry periods when the need for forage is greater. Guazuma ulmifolia Lam. is a tree native to tropical America that has a high forage potential. This species is mentioned in a number of studies assessing the forage potential of trees in a diverse array of environments and v...

  20. Characterizing fish responses to a river restoration over 21 years based on species' traits.

    Science.gov (United States)

    Höckendorff, Stefanie; Tonkin, Jonathan D; Haase, Peter; Bunzel-Drüke, Margret; Zimball, Olaf; Scharf, Matthias; Stoll, Stefan

    2017-10-01

    Understanding restoration effectiveness is often impaired by a lack of high-quality, long-term monitoring data and, to date, few researchers have used species' trait information to gain insight into the processes that drive the reaction of fish communities to restoration. We examined fish-community responses with a highly resolved data set from 21 consecutive years of electrofishing (4 years prerestoration and 17 years postrestoration) at multiple restored and unrestored reaches from a river restoration project on the Lippe River, Germany. Fish abundance peaked in the third year after the restoration; abundance was 6 times higher than before the restoration. After 5-7 years, species richness and abundance stabilized at 2 and 3.5 times higher levels relative to the prerestoration level, respectively. However, interannual variability of species richness and abundance remained considerable, illustrating the challenge of reliably assessing restoration outcomes based on data from individual samplings, especially in the first years following restoration. Life-history and reproduction-related traits best explained differences in species' responses to restoration. Opportunistic short-lived species with early female maturity and multiple spawning runs per year exhibited the strongest increase in abundance, which reflected their ability to rapidly colonize new habitats. These often small-bodied and fusiform fishes typically live in dynamic and ephemeral instream and floodplain areas that river-habitat restorations often aim to create, and in this case their increases in abundance indicated successful restoration. Our results suggest that a greater consideration of species' traits may enhance the causal understanding of community processes and the coupling of restoration to functional ecology. Trait-based assessments of restoration outcomes would furthermore allow for easier transfer of knowledge across biogeographic borders than studies based on taxonomy. © 2017 Society for

  1. Optimising invasive fish management in the context of invasive species legislation in South Africa

    Directory of Open Access Journals (Sweden)

    Darragh J. Woodford

    2017-03-01

    Full Text Available Background: South Africa hosts a large number of non-native freshwater fishes that were introduced for various industries. Many of these species are now listed under the National Environmental Management: Biodiversity Act (NEM:BA Alien and Invasive Species (A&IS lists and regulations, though the practical options available to conservation agencies to effectively manage these fishes vary greatly among species and regions. Objectives & methods: We assessed the history and status of national legislation pertaining to invasive freshwater fishes, and the practical implications of the legislation for managing different species with contrasting distributions, impacts and utilisation value. Results: The smallmouth bass, despite being a potential conflict-generating species, is fairly straightforward to manage based on current legislation. Two species of trout, which remain absent from the NEM:BA A&IS lists because of ongoing consultation with stakeholders, continue to be managed in regions like the Western Cape province using existing provincial legislation. To maximise the limited capacity for management within conservation agencies, we proposed a decision-support tool that prioritises invasive fish populations that represent high environmental risk and low potential for conflict with stakeholders. Using three case studies, we demonstrated how the tool can be used to set management goals of ‘eradicate’, ‘manage against impacts and further spread’ and ‘continue to monitor population’ as the most pragmatic solutions given the state of an invasion, its socio-economic impact and the capacity of the responsible agency to act. Conclusion: By choosing a pragmatic management strategy, conservation agencies can maximise the effective deployment of limited resources, while minimising avoidable conflicts with stakeholders.

  2. Feeding habits of four species of mesopelagic fishes from the Northern Chilean.

    Science.gov (United States)

    Oliva A, Eduardo; Ulloa H, Raúl; Bleck Z, Jorge

    2006-06-01

    The feeding habits of four species of mesopelagic fishes from northern Chile are described: Triphoturus mexicanus, Diogenichtys atlanticus, Vinciguerria lucetia and Cyclothone acclinidens. Samples were captured in September 1988 between 18 degrees 25' and 19 degrees 09'S in the South West Pacific. The quantitative and qualitative analyses of the stomach content showed that the species have a zooplanktophagous opportunistic behavior, mainly predating on Crustaceans, especially on Copepods. The evaluation of the trophic spectrum and diversity of T. mexicanus and C. acclinidens suggests that these are nictoepipelagic species, while D. atlanticus and V. lucetia would be typical mesopelagic.

  3. Global and Regional Patterns in Riverine Fish Species Richness: A Review

    Directory of Open Access Journals (Sweden)

    Thierry Oberdorff

    2011-01-01

    Full Text Available We integrate the respective role of global and regional factors driving riverine fish species richness patterns, to develop a synthetic model of potential mechanisms and processes generating these patterns. This framework allows species richness to be broken down into different components specific to each spatial extent and to establish links between these components and the processes involved. This framework should help to answer the questions that are currently being asked by society, including the effects of species invasions, habitat loss, or fragmentation and climate change on freshwater biodiversity.

  4. Vertebrate Herbivore Browsing on Neighboring Forage Species Increases the Growth and Dominance of Siberian Alder Across a Latitudinal Transect in Northern Alaska.

    Science.gov (United States)

    McNeill, E. M.; Ruess, R. W.

    2017-12-01

    Vertebrate herbivores strongly influence plant growth and architecture, biogeochemical cycling, and successional dynamics in boreal and arctic ecosystems. One of the most notable impacts of vertebrate herbivory is on the growth and spread of alder, a chemically-defended, N-fixing shrub whose distribution in the Alaskan arctic has expanded dramatically over the past 60 years. Although herbivore effects on thin-leaf alder are well described for interior Alaskan floodplains, no work has been conducted on the effects of herbivores on Siberian alder (Alnus viridis spp fruticosa), despite the increasing importance of this species to high latitude ecosystems. We characterized browsing by snowshoe hares, moose, and willow ptarmigan on dominant shrub species across topo-edaphic sequences within 5 ecoregions along a 600 km latitudinal transect extending from interior Alaska to the North Slope. Ptarmigan browsed wind-blown lowland and alpine sites devoid of trees in all regions; moose browsed predominantly willow species in hardwood and mixed forests and were absent north of the Brooks Range; snowshoe hares selected habitats and forage based on their local density and vulnerability to predators. Browsing intensity on Siberian alder was either undetectable or low, limited primarily to hare browsing on young ramets in the northern boreal forest where hare density relative to forage availability is highest. Overall, alder height growth was positively correlated with levels of herbivory on competing shrub species. Our data support the hypothesis that vertebrate herbivore browsing is indirectly augmenting the growth, dominance, and possible spread of Siberian alder throughout its northern Alaskan range. Given the potential high rates of N-fixation inputs by Siberian alder, we believe herbivores are also having strong indirect effects on biogeochemical cycling and possibly C storage in these landscapes.

  5. Forage quantity and quality

    Science.gov (United States)

    Jorgenson, Janet C.; Udevitz, Mark S.; Felix, Nancy A.; Douglas, David C.; Reynolds, Patricia E.; Rhode, E.B.

    2002-01-01

    The Porcupine caribou herd has traditionally used the coastal plain of the Arctic National Wildlife Refuge, Alaska, for calving. Availability of nutritious forage has been hypothesized as one of the reasons the Porcupine caribou herd migrates hundreds of kilometers to reach the coastal plain for calving (Kuropat and Bryant 1980, Russell et al. 1993).Forage quantity and quality and the chronology of snowmelt (which determines availability and phenological stages of forage) have been suggested as important habitat attributes that lead calving caribou to select one area over another (Lent 1980, White and Trudell 1980, Eastland et al. 1989). A major question when considering the impact of petroleum development is whether potential displacement of the caribou from the 1002 Area to alternate calving habitat will limit access to high quantity and quality forage.Our study had the following objectives: 1) quantify snowmelt patterns by area; 2) quantify relationships among phenology, biomass, and nutrient content of principal forage species by vegetation type; and 3) determine if traditional concentrated calving areas differ from adjacent areas with lower calving densities in terms of vegetation characteristics.

  6. Impact of genetically improved fish species and technology on selected hatchery and fish production in Bangladesh

    Directory of Open Access Journals (Sweden)

    MS Islam

    2017-06-01

    Full Text Available The study was carried out in IAPP commanding areas from July to September 2015. A total of 8 hatchery and 240 farmers were selected for this study from Rangpur and Barisal region. About 153% Tilapia production increased which was from 34 to 86 lakh, which was 148% in Rangpur district. Thai koi production was increased about 320% in Rangpur and it was 152% in Barisal. It was observed that, per hatchery Tilapia profit was Tk. 17.35 lakh and Tk. 17.18 lakh in Rangpur and Barisal, respectively. While, total profit was 3.9 times more for Thai koi in Rangpur and it was about 1.7 times more in Barisal after IAPP-BFRI project implementation. Impact of improved germplasm on grow out system was estimated. Finding shows that before IAPP-BFRI project the average harvesting weight of tilapia fish was 122g but after using IAPP-BFRI germplasm, it increased to 194g in Rangpur district. In case of Thai Koi, the harvesting weight gain was 26% in Rangpur district and it was statistically significant at 1% level. Survey results also show that per acre profit was only Tk.86671 for Tilapia farming before IAPP whereas it was increased to Tk. 234853 after IAPP-BFRI intervention. At the same time, profit from Thai Koi was increased about 189% after IAPPBFRI activities. Similarly, profit was increased about 86% in case of Pangus farming and this positive impact was statistically significant at 1% level. Therefore, it may conclude that, farmers can significantly increase Tilapia, Thai Koi and Pangus production as well as can maximize profit using IAPP technology.

  7. Turbidity interferes with foraging success of visual but not chemosensory predators.

    Science.gov (United States)

    Lunt, Jessica; Smee, Delbert L

    2015-01-01

    Predation can significantly affect prey populations and communities, but predator effects can be attenuated when abiotic conditions interfere with foraging activities. In estuarine communities, turbidity can affect species richness and abundance and is changing in many areas because of coastal development. Many fish species are less efficient foragers in turbid waters, and previous research revealed that in elevated turbidity, fish are less abundant whereas crabs and shrimp are more abundant. We hypothesized that turbidity altered predatory interactions in estuaries by interfering with visually-foraging predators and prey but not with organisms relying on chemoreception. We measured the effects of turbidity on the predation rates of two model predators: a visual predator (pinfish, Lagodon rhomboides) and a chemosensory predator (blue crabs, Callinectes sapidus) in clear and turbid water (0 and ∼100 nephelometric turbidity units). Feeding assays were conducted with two prey items, mud crabs (Panopeus spp.) that rely heavily on chemoreception to detect predators, and brown shrimp (Farfantepenaus aztecus) that use both chemical and visual cues for predator detection. Because turbidity reduced pinfish foraging on both mud crabs and shrimp, the changes in predation rates are likely driven by turbidity attenuating fish foraging ability and not by affecting prey vulnerability to fish consumers. Blue crab foraging was unaffected by turbidity, and blue crabs were able to successfully consume nearly all mud crab and shrimp prey. Turbidity can influence predator-prey interactions by reducing the feeding efficiency of visual predators, providing a competitive advantage to chemosensory predators, and altering top-down control in food webs.

  8. Integrative taxonomy detects cryptic and overlooked fish species in a neotropical river basin.

    Science.gov (United States)

    Gomes, Laís Carvalho; Pessali, Tiago Casarim; Sales, Naiara Guimarães; Pompeu, Paulo Santos; Carvalho, Daniel Cardoso

    2015-10-01

    The great freshwater fish diversity found in the neotropical region makes management and conservation actions challenging. Due to shortage of taxonomists and insufficient infrastructure to deal with such great biodiversity (i.e. taxonomic impediment), proposed remedies to accelerate species identification and descriptions include techniques that combine DNA-based identification and concise morphological description. The building of a DNA barcode reference database correlating meristic and genetic data was developed for 75 % of the Mucuri River basin's freshwater fish. We obtained a total of 141 DNA barcode sequences from 37 species belonging to 30 genera, 19 families, and 5 orders. Genetic distances within species, genera, and families were 0.74, 9.5, and 18.86 %, respectively. All species could be clearly identified by the DNA barcodes. Divergences between meristic morphological characteristics and DNA barcodes revealed two cryptic species among the Cyphocharax gilbert and Astyanax gr. bimaculatus specimens, and helped to identify two overlooked species within the Gymnotus and Astyanax taxa. Therefore, using a simplified model of neotropical biodiversity, we tested the efficiency of an integrative taxonomy approach for species discovery, identification of cryptic diversity, and accelerating biodiversity descriptions.

  9. Mayfly and fish species identification and sex determination in bleak (Alburnus alburnus) by MALDI-TOF mass spectrometry.

    Science.gov (United States)

    Maasz, G; Takács, P; Boda, P; Varbiro, G; Pirger, Z

    2017-12-01

    Besides food quality control of fish or cephalopods, the novel mass spectrometry (MS) approaches could be effective and beneficial methods for the investigation of biodiversity in ecological research. Our aims were to verify the applicability of MALDI-TOF MS in the rapid identification of closely related species, and to further develop it for sex determination in phenotypically similar fish focusing on the low mass range. For MALDI-TOF MS spectra analysis, ClinProTools software was applied, but our observed classification was also confirmed by Self Organizing Map. For verifying the wide applicability of the method, brains from invertebrate and vertebrate species were used in order to detect the species related markers from two mayflies and eight fish as well as sex-related markers within bleak. Seven Ephemera larvae and sixty-one fish species related markers were observed and nineteen sex-related markers were identified in bleak. Similar patterns were observed between the individuals within one species. In contrast, there were markedly diverse patterns between the different species and sexes visualized by SOMs. Two different Ephemera species and male or female fish were identified with 100% accuracy. The various fish species were classified into 8 species with a high level of accuracy (96.2%). Based on MS data, dendrogram was generated from different fish species by using ClinProTools software. This MS-based dendrogram shows relatively high correspondence with the phylogenetic relationships of both the studied species and orders. In summary, MALDI-TOF MS provides a cheap, reliable, sensitive and fast identification tool for researchers in the case of closely related species using mass spectra acquired in a low mass range to define specific molecular profiles. Moreover, we presented evidence for the first time for determination of sex within one fish species by using this method. We conclude that it is a powerful tool that can revolutionize ecological and

  10. The Bifurcation and Control of a Single-Species Fish Population Logistic Model with the Invasion of Alien Species

    Directory of Open Access Journals (Sweden)

    Yi Zhang

    2014-01-01

    Full Text Available The objective of this paper is to study systematically the bifurcation and control of a single-species fish population logistic model with the invasion of alien species based on the theory of singular system and bifurcation. It regards Spartina anglica as an invasive species, which invades the fisheries and aquaculture. Firstly, the stabilities of equilibria in this model are discussed. Moreover, the sufficient conditions for existence of the trans-critical bifurcation and the singularity induced bifurcation are obtained. Secondly, the state feedback controller is designed to eliminate the unexpected singularity induced bifurcation by combining harvested effort with the purification capacity. It obviously inhibits the switch of population and makes the system stable. Finally, the numerical simulation is proposed to show the practical significance of the bifurcation and control from the biological point of view.

  11. Species profiles: Life histories and environmental requirements of coastal fishes and invertebrates (south Florida)

    Energy Technology Data Exchange (ETDEWEB)

    Jory, D.E.; Iversen, E.S. (Miami Univ., FL (USA). Rosenstiel School of Marine and Atmospheric Sciences)

    1989-08-01

    Black, red, and Nassau groupers (Mycteroperca bonaci, Epinephelus morio, and E. striatus, respectively) are widely distributed on rocky bottoms and reefs along the south Florida coast. They are the most valuable marine finfish group in Florida, comprising about 25% of the total value of landings in 1984. The three species can be distinguished by morphometric, meristic, and body color characteristics. Younger fish are typically found in shallow, inshore grass beds, and larger, older fish are generally restricted to deep waters. The three species are protogynous hermaphrodites. Sexual transition can occur at any length over about 300 mm SL. An offshore movement apparently coincides with the onset of sexual maturity. Spawning aggregations have been observed throughout the year, but occur mostly between late spring and early summer. Fecundity estimates range from about 800,000 to 5,000,000 eggs per female. Both the eggs and the larvae are planktonic. Their early life history is poorly known. Larvae probably leave the plankton and become benthic at around 20--30 mm SL. Growth rates range from about 2 to 10 mm/month. The three species are unspecialized carnivores, feeding on a variety of fishes, crustaceans, and mollusks. Interspecific competition for food and shelter may be common because of the overlap in distribution, habitat, size, and food habitats. For the three species, a number of predators and parasites have been reported. Both the black and red groupers have been implicated in ciguatera poisonings in south Florida. 70 refs., 3 figs., 3 tabs.

  12. Ecological conversion efficiency and its influencers in twelve species of fish in the Yellow Sea Ecosystem

    Science.gov (United States)

    Tang, Qisheng; Guo, Xuewu; Sun, Yao; Zhang, Bo

    2007-09-01

    The ecological conversion efficiencies in twelve species of fish in the Yellow Sea Ecosystem, i.e., anchovy ( Engraulis japonicus), rednose anchovy ( Thrissa kammalensis), chub mackerel ( Scomber japonicus), halfbeak ( Hyporhamphus sajori), gizzard shad ( Konosirus punctatus), sand lance ( Ammodytes personatus), red seabream ( Pagrus major), black porgy ( Acanthopagrus schlegeli), black rockfish ( Sebastes schlegeli), finespot goby ( Chaeturichthys stigmatias), tiger puffer ( Takifugu rubripes), and fat greenling ( Hexagrammos otakii), were estimated through experiments conducted either in situ or in a laboratory. The ecological conversion efficiencies were significantly different among these species. As indicated, the food conversion efficiencies and the energy conversion efficiencies varied from 12.9% to 42.1% and from 12.7% to 43.0%, respectively. Water temperature and ration level are the main factors influencing the ecological conversion efficiencies of marine fish. The higher conversion efficiency of a given species in a natural ecosystem is acquired only under the moderate environment conditions. A negative relationship between ecological conversion efficiency and trophic level among ten species was observed. Such a relationship indicates that the ecological efficiency in the upper trophic levels would increase after fishing down marine food web in the Yellow Sea ecosystem.

  13. Susceptibility of Japanese Cyprininae fish species to cyprinid herpesvirus 2 (CyHV-2).

    Science.gov (United States)

    Ito, Takafumi; Maeno, Yukio

    2014-03-14

    Cyprinid herpesvirus 2 (CyHV-2) is known as the causative agent of herpesviral haematopoietic necrosis (HVHN) of goldfish (Carassius auratus). Recently, the virus has also been detected from Prussian carp (C. gibelio) and crucian carp (C. carassius) from European and Asian countries. To analyze the risk of spreading to new host species, the susceptibility of other fish species to the virus is essential. In this study experimental infections of indigenous Cyprininae species in Japan were performed by immersion in and intraperitoneal injection of a CyHV-2 isolate. Although Edonishiki, a variety of goldfish, immersed with the virus showed a cumulative mortality of 90%, no mortality was observed in ginbuna C. auratus langsdorfii, nagabuna C. auratus buergeri, nigorobuna C. auratus grandoculis and common carp Cyprinus carpio. Cumulative mortality was 100, 20 and 10% in intraperitoneally injected Edonishiki, ginbuna and nagabuna, respectively. Furthermore all Edonishiki immersed with the virus died. However, even after stimuli of sudden temperature changes, the immersed ginbuna and nagabuna did not die. Moreover no mortality was observed in co-reared Ranchu, another variety of goldfish, with immersed ginbuna and nagabuna although all three Ranchu co-reared with immersed Edonishiki died. CyHV-2 DNA was detected and the virus was re-isolated from all dead fish. Moreover CyHV-2 DNA was detected from some of the surviving Carassius spp. These results revealed that susceptibility of Japanese indigenous Cyprininae fish species to CyHV-2 is much lower than for goldfish. In addition, ability of replication of CyHV-2 might be different among Carassius fish species. Copyright © 2014 Elsevier B.V. All rights reserved.

  14. COMPARATIVE STUDIES ON EFFECTS OF FREEZING ON PHYSICOCHEMICAL PROPERTIES OF FILLETS TWO FISH SPECIES IN IRAN

    Directory of Open Access Journals (Sweden)

    Ali Aberoumand

    2018-04-01

    Full Text Available Because of fishes Sparidentex hasta and Pampus argenteus in the southern of Iran are consumed abundant in a particular season and it should be frozen for consumption throughout the year. Therefore, this research was carried out to investigate the effects of freezing on some of the physicochemical properties of fillets the fishes. Factors such as fat with chloroform-methanol method, amount of TBA (Thiobarbituric acid in fish muscle accordance method of Pearson, pH using a pH meter, FFA (Free fatty acids with titration in the presence of phenolphthalein was determined based on the percentage of oleic acid, peroxide value according to AOAC (Association of Official Analytical Chemists, in fresh samples at time zero and after different periods of freezing were tested respectively. Result showd that TBA (Thiobarbituric acid content in fish fillet, found Pampus argenteus and Sparidentex hasta 0.65 and 0.53 respectively. The results showed that the highest percentage of fat found for Pampus argenteus at 95 days 24.2(%2 and for Sparidentex hasta at 35 days (25.19%, free fatty acids contents found highest (0.9% and (0.97% for Sparidentex hasta and Pampus argenteus after 95 days. It can conclude that the TBA (Thiobarbituric acid, FFA (Free fatty acids  contents and pH of both fish species during storage in freezer were increased. Peroxide value in fish Pampus argenteus was reduced but, in Sparidentex hasta showed no significant differently.  The best time of storage of fishes Pampus argenteus and Sparidentex hasta at -18 °C was 35 days freezing, but nutritional value of fillets and fatty acids greatly reduced

  15. Ocean acidification alters the otoliths of a pantropical fish species with implications for sensory function.

    Science.gov (United States)

    Bignami, Sean; Enochs, Ian C; Manzello, Derek P; Sponaugle, Su; Cowen, Robert K

    2013-04-30

    Ocean acidification affects a wide diversity of marine organisms and is of particular concern for vulnerable larval stages critical to population replenishment and connectivity. Whereas it is well known that ocean acidification will negatively affect a range of calcareous taxa, the study of fishes is more limited in both depth of understanding and diversity of study species. We used new 3D microcomputed tomography to conduct in situ analysis of the impact of ocean acidification on otolith (ear stone) size and density of larval cobia (Rachycentron canadum), a large, economically important, pantropical fish species that shares many life history traits with a diversity of high-value, tropical pelagic fishes. We show that 2,100 μatm partial pressure of carbon dioxide (pCO2) significantly increased not only otolith size (up to 49% greater volume and 58% greater relative mass) but also otolith density (6% higher). Estimated relative mass in 800 μatm pCO2 treatments was 14% greater, and there was a similar but nonsignificant trend for otolith size. Using a modeling approach, we demonstrate that these changes could affect auditory sensitivity including a ∼50% increase in hearing range at 2,100 μatm pCO2, which may alter the perception of auditory information by larval cobia in a high-CO2 ocean. Our results indicate that ocean acidification has a graded effect on cobia otoliths, with the potential to substantially influence the dispersal, survival, and recruitment of a pelagic fish species. These results have important implications for population maintenance/replenishment, connectivity, and conservation efforts for other valuable fish stocks that are already being deleteriously impacted by overfishing.

  16. Widespread hybridization and bidirectional introgression in sympatric species of coral reef fish

    KAUST Repository

    Harrison, Hugo B.

    2017-10-28

    Coral reefs are highly diverse ecosystems, where numerous closely related species often coexist. How new species arise and are maintained in these high geneflow environments have been long-standing conundrums. Hybridization and patterns of introgression between sympatric species provide a unique insight into the mechanisms of speciation and the maintenance of species boundaries. In this study, we investigate the extent of hybridization between two closely related species of coral reef fish: the common coral trout (Plectropomus leopardus) and the bar-cheek coral trout (Plectropomus maculatus). Using a complementary set of 25 microsatellite loci, we distinguish pure genotype classes from first- and later-generation hybrids, identifying 124 interspecific hybrids from a collection of 2,991 coral trout sampled in inshore and mid-shelf reefs of the southern Great Barrier Reef. Hybrids were ubiquitous among reefs, fertile and spanned multiple generations suggesting both ecological and evolutionary processes are acting to maintain species barriers. We elaborate on these finding to investigate the extent of genomic introgression and admixture from 2,271 SNP loci recovered from a ddRAD library of pure and hybrid individuals. An analysis of genomic clines on recovered loci indicates that 261 SNP loci deviate from a model of neutral introgression, of which 132 indicate a pattern of introgression consistent with selection favouring both hybrid and parental genotypes. Our findings indicate genome-wide, bidirectional introgression between two sympatric species of coral reef fishes and provide further support to a growing body of evidence for the role of hybridization in the evolution of coral reef fishes.

  17. Genotoxic effects of water pollution on two fish species living in Karasu River, Erzurum, Turkey.

    Science.gov (United States)

    Yazıcı, Zehra; Sişman, Turgay

    2014-11-01

    Karasu River, which is the only river in the Erzurum plain, is the source of the Euphrates River (Eastern Anatolia of Turkey). The river is in a serious environmental situation as a result of pollution by agricultural and industrial sewage and domestic discharges. The present study aims to evaluate genotoxic effects of toxic metals in chub, Leuciscus cephalus, and transcaucasian barb, Capoeta capoeta, collected from contaminated site of the Karasu River, in comparison with fish from an unpolluted reference site. Heavy metal concentrations in surface water of the river were determined. The condition factor (CF) was taken as a general biomarker of the health of the fish, and genotoxicity assays such as micronucleus (MN) and other nuclear abnormalities (NA) were carried out on the fish species studied. MN and NA such as kidney-shaped nucleus, notched nucleus, binucleated, lobed nucleus, and blebbed nucleus were assessed in peripheral blood erythrocytes, gill epithelial cells, and liver cells of the fish. A significant decrease in CF values associated with a significant elevation in MN and NA frequencies was observed in fish collected from the polluted sites compared with those from the reference site. Results of the current study show the significance of integrating a set of biomarkers to identify the effects of anthropogenic pollution. High concentrations of heavy metals have a potential genotoxic effects, and the toxicity is possibly related to industrial, agricultural, and domestic activities.

  18. Effects of fishing technique on assessing species composition in aquatic systems in semi-arid Brazil

    Directory of Open Access Journals (Sweden)

    ESF Medeiros

    Full Text Available In most ecological field research, appropriate sampling is critical for the understanding of processes underlying fish populations and communities, and is even more important in heterogeneous environments such as the aquatic systems of the semi-arid region of Brazil. This study intends to make a contribution to the development of sampling programs and gear selection in aquatic systems of semi-arid Brazil by evaluating the effects of different fishing techniques on the assessment of richness and composition of the fish fauna in selected aquatic environments. Six sites were selected to represent typical artificial (reservoirs and natural (intermittent streams environments and four different types of sampling gear were applied to each site during four occasions. The present study shows that when selecting sampling techniques to be used in aquatic systems in semi-arid Brazil, one must consider the objectives of the study, e.g. ecological or taxonomic, in order to decide on inclusion of rare species in the sampling population. Also, the effect of the sampling gear on natural abundances of fish must be considered given that some sampling techniques are highly detrimental to fish population numbers.

  19. forage systems mixed with forage legumes grazed by lactating cows

    Directory of Open Access Journals (Sweden)

    Clair Jorge Olivo

    2017-02-01

    Full Text Available Current research evaluates productivity, stocking and nutritional rates of three forage systems with Elephant Grass (EG + Italian Ryegrass (IR + Spontaneous Growth Species (SGS, without forage legumes; EG + IR + SGS + Forage Peanut (FP, mixed with FP; and EG + IR + SGS + Red Clover (RC, mixed with RC, in rotational grazing method by lactating cows. IR developed between rows of EG. FP was maintained, whilst RC was sow to respective forage systems. The experimental design was completely randomized, with three treatments and two replication, subdivided into parcels over time. Mean rate for forage yield and average stocking rate were 10.6, 11.6 and 14.4 t ha-1; 3.0, 2.8 and 3.1 animal unit ha-1 day-1, for the respective systems. Levels of crude protein and total digestible nutrients were 17.8, 18.7 and 17.5%; 66.5, 66.8 and 64.8%, for the respective forage systems. The presence of RC results in better and higher forage yield in the mixture, whilst FP results in greater control of SGS. The inclusion of forage legumes in pasture systems provides better nutritional rates.

  20. An eDNA Assay to Monitor a Globally Invasive Fish Species from Flowing Freshwater.

    Science.gov (United States)

    Adrian-Kalchhauser, Irene; Burkhardt-Holm, Patricia

    2016-01-01

    Ponto-Caspian gobies are a flock of five invasive fish species that have colonized freshwaters and brackish waters in Europe and North America. One of them, the round goby Neogobius melanostomus, figures among the 100 worst invaders in Europe. Current methods to detect the presence of Ponto-Caspian gobies involve catching or sighting the fish. These approaches are labor intense and not very sensitive. Consequently, populations are usually detected only when they have reached high densities and when management or containment efforts are futile. To improve monitoring, we developed an assay based on the detection of DNA traces (environmental DNA, or eDNA) of Ponto-Caspian gobies in river water. The assay specifically detects invasive goby DNA and does not react to any native fish species. We apply the assay to environmental samples and demonstrate that parameters such as sampling depth, sampling location, extraction protocol, PCR protocol and PCR inhibition greatly impact detection. We further successfully outline the invasion front of Ponto-Caspian gobies in a large river, the High Rhine in Switzerland, and thus demonstrate the applicability of the assay to lotic environments. The eDNA assay requires less time, equipment, manpower, skills, and financial resources than the conventional monitoring methods such as electrofishing, angling or diving. Samples can be taken by untrained individuals, and the assay can be performed by any molecular biologist on a conventional PCR machine. Therefore, this assay enables environment managers to map invaded areas independently of fishermen's' reports and fish community monitorings.

  1. 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.

  2. The Effects of Zebra Mussels (Dreissena polymorpha) on the Foraging Success of Eurasian Perch (Perca fluviatilis) and Ruffe (Gymnocephalus cernuus)

    Science.gov (United States)

    Dieterich, Axel; Mörtl, Martin; Eckmann, Reiner

    2004-07-01

    Complex habitat structures can influence the foraging success of fish. Competition for food between fish species can therefore depend on the competitors' abilities to cope with structural complexity. In laboratory experiments, we comparatively assessed effects of zebra mussels (Dreissena polymorpha Pall.) on the foraging success of Eurasian perch (Perca fluviatilis L.) and ruffe (Gymnocephalus cernuus (L.)). In single-species and mixed-species experiments, the fish were fed caddisfly larvae (Tinodes waeneri (L.)) over complex (mussel-covered stones) and less-complex (bare stones) substrates. With intraspecific competition, food consumption by perch and ruffe decreased significantly when the complex substrate was used. With interspecific competition, food consumption by perch and ruffe did not change with substrate complexity, but perch clearly out-competed ruffe on both substrates. Zebra mussel beds provide a refuge for macrozoobenthos against predation by ruffe and probably also by perch. (

  3. Historical change in fish species distribution: shifting reference conditions and global warming effects.

    Science.gov (United States)

    Pont, Didier; Logez, M; Carrel, G; Rogers, C; Haidvogl, G

    Species distributions models (SDM) that rely on estimated relationships between present environmental conditions and species presence-absence are widely used to forecast changes of species distributions caused by global warming but far less to reconstruct historical assemblages. By compiling historical fish data from the turn to the middle of the twentieth century in a similar way for several European catchments (Rhône, Danube), and using already published SDMs based on current observations, we: (1) tested the predictive accuracy of such models for past climatic conditions, (2) compared observed and expected cumulated historical species occurrences at sub-catchment level, and (3) compared the annual variability in the predictions within one sub-catchment (Salzach) under a future climate scenario to the long-term variability of occurrences reconstructed during an extended historical period (1800-2000). We finally discuss the potential of these SDMs to define a "reference condition", the possibility of a shift in baseline condition in relation with anthropogenic pressures, and past and future climate variability. The results of this study clearly highlight the potential of SDM to reconstruct the past composition of European fish assemblages and to analyze the historical ecological status of European rivers. Assessing the uncertainty associated with species distribution projections is of primary importance before evaluating and comparing the past and future distribution of species within a given catchment.

  4. 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

  5. Microplastics as a vector for the transport of the bacterial fish pathogen species Aeromonas salmonicida.

    Science.gov (United States)

    Viršek, Manca Kovač; Lovšin, Marija Nika; Koren, Špela; Kržan, Andrej; Peterlin, Monika

    2017-12-15

    Microplastics is widespread in the marine environment where it can cause numerous negative effects. It can provide space for the growth of organisms and serves as a vector for the long distance transfer of marine microorganisms. In this study, we examined the sea surface concentrations of microplastics in the North Adriatic and characterized bacterial communities living on the microplastics. DNA from microplastics particles was isolated by three different methods, followed by PCR amplification of 16S rDNA, clone libraries preparation and phylogenetic analysis. 28 bacterial species were identified on the microplastics particles including Aeromonas spp. and hydrocarbon-degrading bacterial species. Based on the 16S rDNA sequences the pathogenic fish bacteria Aeromonas salmonicida was identified for the first time on microplastics. Because A. salmonicida is responsible for illnesses in fish, it is crucial to get answers if and how microplastics pollution is responsible for spreading of diseases. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Mercury and selenium levels in 19 species of saltwater fish from New Jersey as a function of species, size, and season

    Science.gov (United States)

    Burger, Joanna; Gochfeld, Michael

    2014-01-01

    There are few data on risks to biota and humans from mercury levels in saltwater fish. This paper examines mercury and selenium levels in muscle of 19 species of fish caught by recreational fisherfolk off the New Jersey shore, as a function of species of fish, size, and season, and risk of mercury to consumers. Average mercury levels ranged from 0.01 ppm (wet weight) (Menhaden Brevoortia tyrannus) to 1.83 ppm (Mako Shark Isurus oxyrinchus). There were four categories of mercury levels: very high (only Mako), high (averaging 0.3–0.5 ppm, 3 species), medium (0.14–0.20 ppm, 10 species), and low (below 0.13 ppm, 5 species). Average selenium levels for the fish species ranged from 0.18 ppm to 0.58 ppm, and had lower variability than mercury (coefficient of variation=38.3 vs 69.1%), consistent with homeostatic regulation of this essential element. The correlation between mercury and selenium was significantly positive for five and negative for two species. Mercury levels showed significant positive correlations with fish size for ten species. Size was the best predictor of mercury levels. Selenium showed no consistent relationship to fish length. Over half of the fish species had some individual fish with mercury levels over 0.3 ppm, and a third had fish with levels over 0.5 ppm, levels that pose a human health risk for high end consumers. Conversely several fish species had no individuals above 0.5 ppm, and few above 0.3 ppm, suggesting that people who eat fish frequently, can reduce their risk from mercury by selecting which species (and which size) to consume. Overall, with the exception of shark, Bluefin Tuna (Thunnus thynnus), Bluefish (Pomatomus saltatrix) and Striped Bass (Morone saxatilis), the species sampled are generally medium to low in mercury concentration. Selenium:mercury molar ratios were generally above 1:1, except for the Mako shark. PMID:21292311

  7. Improvement scheme for the determination of arsenic species in mussel and fish tissues

    DEFF Research Database (Denmark)

    Lagarde, F.; Amran, M. B.; Leroy, M. J. F.

    1999-01-01

    Six interlaboratory studies were organised by the Standard, Measurement and Testing Programme of the European Commission on the determination of arsenic species (arsenobetaine, arsenocholine, monomethylarsonic acid, dimethylarsinic acid, As(III) and As(V)) in marine matrices and soil. A step-by-s...... and at the end of the six campaigns allowed the certification of a reference material of tuna-fish tissue (BCR-CRM 627) for its total arsenic, arsenobetaine and dimethylarsinic acid contents....

  8. Critically endangered fish species of Turkish Seas (Mediterranean and Aegean): Longfin gurnard, Chelidonichthys obscurus (Walbaum, 1792)

    OpenAIRE

    Cemal Turan; Deniz Ergüden; Mevlüt Gürlek

    2016-01-01

    Longfin gurnard Chelidonichthys obscurus (Walbaum, 1792) is reported several times from various researchers in the checklist of Turkish marine fishes. However, last three decades, the species is not occurred in the distributional range, comprising the northeastern Mediterranean Sea and Aegean Sea coast of Turkey. It is possibly critically endangered or absent in the Turkish Seas. Moreover, there has no any biological study been carried out on C. obscurus in Turkey. C. obscurus is considered t...

  9. Non-native fish introductions in the Czech Republic – species inventory, facts and future perspectives

    Czech Academy of Sciences Publication Activity Database

    Musil, J.; Jurajda, Pavel; Adámek, Z.; Horký, P.; Slavík, O.

    2010-01-01

    Roč. 26, Suppl. 2 (2010), s. 38-45 ISSN 0175-8659. [International Conference and Workshop on Managing Alien Species for Sustainable Development of Aquaculture and Fisheries. Florence, 05.11.2008-07.11.2008] Institutional research plan: CEZ:AV0Z60930519 Keywords : freshwater fish * fisheries management * invasion success Subject RIV: EH - Ecology, Behaviour Impact factor: 0.945, year: 2010

  10. Selenium and mercury molar ratios in saltwater fish from New Jersey: Individual and species variability complicate use in human health fish consumption advisories☆

    Science.gov (United States)

    Burger, Joanna; Gochfeld, Michael

    2014-01-01

    Balancing risk versus benefits to humans and other organisms from consuming fish is a national concern in the USA, as well as in many other parts of the world. Protecting public health is both a federal and state responsibility, and states respond by issuing fish consumption advisories, particularly for mercury. Recently it has been emphasized that the protective role of selenium against mercury toxicity depends on their molar ratios, which should be evaluated as an indication of selenium’s protective capacity, and incorporated in risk assessments for fish consumption. However, there is no single “protective” ratio agreed upon. In this paper we examine the selenium:mercury (Se:Hg) molar ratios in a wide range of saltwater fish caught and eaten by recreational fishers along the New Jersey coast. We were particularly interested in interspecific and intraspecific variability, and whether the molar ratios were consistent within a species, allowing for its use in managing risk. The selenium–mercury molar ratio showed significant variation among and within fish species. The molar ratio decreased with the size of the fish species, decreased with the mercury levels, and within a fish species, the selenium:mercury ratio decreased with fish size. As an essential element, selenium undergoes some homeostatic regulation, but it is also highly toxic. Within species, mercury level tends to increase with size, accounting for the negative relationship between size and ratio. This variability may make it difficult to use the selenium:mercury molar ratio in risk assessment, risk management, and risk communication at this time, and more information is needed on how mercury and selenium actually interact and on the relationship between the molar ratios and health outcomes. PMID:22405995

  11. Genome analysis of Betanodavirus from cultured marine fish species in Malaysia.

    Science.gov (United States)

    Ransangan, Julian; Manin, Benny Obrain

    2012-04-23

    Betanodavirus is the causative agent of the viral nervous necrosis (VNN) or viral encephalopathy and retinopathy disease in marine fish. This disease is responsible for most of the mass mortalities that occurred in marine fish hatcheries in Malaysia. The genome of this virus consists of two positive-sense RNA molecules which are the RNA1 and RNA2. The RNA1 molecule contains the RdRp gene which encodes for the RNA-dependent RNA polymerase and the RNA2 molecule contains the Cp gene which encodes for the viral coat protein. In this study, total RNAs were extracted from 32 fish specimens representing the four most cultured marine fish species in Malaysia. The fish specimens were collected from different hatcheries and aquaculture farms in Malaysia. The RNA1 was successfully amplified using three pairs of overlapping PCR primers whereas the RNA2 was amplified using a pair of primers. The nucleotide analysis of RdRp gene revealed that the Betanodavirus in Malaysia were 94.5-99.7% similar to the RGNNV genotype, 79.8-82.1% similar to SJNNV genotype, 81.5-82.4% similar to BFNNV genotype and 79.8-80.7% similar to TPNNV genotype. However, they showed lower similarities to FHV (9.4-14.2%) and BBV (7.2-15.7%), respectively. Similarly, the Cp gene revealed that the viruses showed high nucleotide similarity to RGNNV (95.9-99.8%), SJNNV (72.2-77.4%), BFNNV (80.9-83.5%), TPNNV (77.2-78.1%) and TNV (75.1-76.5%). However, as in the RdRp gene, the coat protein gene was highly dissimilar to FHV (3.0%) and BBV (2.6-4.1%), respectively. Based on the genome analysis, the Betanodavirus infecting cultured marine fish species in Malaysia belong to the RGNNV genotype. However, the phylogenetic analysis of the genes revealed that the viruses can be further divided into nine sub-groups. This has been expected since various marine fish species of different origins are cultured in Malaysia. Copyright © 2011 Elsevier B.V. All rights reserved.

  12. Intra-seasonal variation in foraging behavior among Adélie penguins (Pygocelis adeliae) breeding at Cape Hallett, Ross Sea, Antarctica

    Science.gov (United States)

    Lyver, P.O.B.; MacLeod, C.J.; Ballard, G.; Karl, B.J.; Barton, K.J.; Adams, J.; Ainley, D.G.; Wilson, P.R.

    2011-01-01

    We investigated intra-seasonal variation in foraging behavior of chick-rearing Adélie penguins, Pygoscelis adeliae, during two consecutive summers at Cape Hallett, northwestern Ross Sea. Although foraging behavior of this species has been extensively studied throughout the broad continental shelf region of the Ross Sea, this is the first study to report foraging behaviors and habitat affiliations among birds occupying continental slope waters. Continental slope habitat supports the greatest abundances of this species throughout its range, but we lack information about how intra-specific competition for prey might affect foraging and at-sea distribution and how these attributes compare with previous Ross Sea studies. Foraging trips increased in both distance and duration as breeding advanced from guard to crèche stage, but foraging dive depth, dive rates, and vertical dive distances travelled per hour decreased. Consistent with previous studies within slope habitats elsewhere in Antarctic waters, Antarctic krill (Euphausia superba) dominated chick meal composition, but fish increased four-fold from guard to crèche stages. Foraging-, focal-, and core areas all doubled during the crèche stage as individuals shifted distribution in a southeasterly direction away from the coast while simultaneously becoming more widely dispersed (i.e., less spatial overlap among individuals). Intra-specific competition for prey among Adélie penguins appears to influence foraging behavior of this species, even in food webs dominated by Antarctic krill.

  13. Determination of trace metals and analysis of arsenic species in tropical marine fishes from Spratly islands.

    Science.gov (United States)

    Li, Jingxi; Sun, Chengjun; Zheng, Li; Jiang, Fenghua; Wang, Shuai; Zhuang, Zhixia; Wang, Xiaoru

    2017-09-15

    Trace metal contents in 38 species of tropical marine fishes harvested from the Spratly islands of China were determined by microwave digestion and inductively coupled plasma mass spectrometry analysis. Arsenic species were determined by high-performance liquid chromatography and inductively coupled plasma mass spectrometry analysis. The average levels of Al, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Mo, Cd, Pb, and U in the fish samples were 1.683, 0.350, 0.367, 2.954, 36.615, 0.087, 0.319, 1.566, 21.946, 20.845, 2.526, 3.583, 0.225, 0.140, and 0.061mg·kg -1 , respectively; Fe, Zn, and As were found at high concentrations. The trace metals exhibited significant positive correlation between each other, with r value of 0.610-0.852. Further analysis indicated that AsB (8.560-31.020mg·kg -1 ) was the dominant arsenic species in the fish samples and accounted for 31.48% to 47.24% of the total arsenic. As(III) and As(V) were detected at low concentrations, indicating minimal arsenic toxicity. Copyright © 2017. Published by Elsevier Ltd.

  14. Endoparasite fauna of five Gadiformes fish species from the coast of Chile: host ecology versus phylogeny.

    Science.gov (United States)

    Chávez, R A; González, M T; Oliva, M E; Valdivia, I M

    2012-03-01

    The aims of the present study were to compare, using multivariate analyses, the degree of similarity of the endoparasite fauna of five fish species belonging to the order Gadiformes: Merluccius gayi, Merluccius australis, Macruronus magellanicus (Gadoidei) and Micromesistius australis and Nezumia pulchella (Macrouroidei), from the southern and central Chilean coast, and to evaluate whether the composition of the endoparasite fauna was determined by phylogenetic or ecological relationships. We employed our database of Merluccius australis, M. magellanicus and Micromesistius australis, which was complemented with published information for M. magellanicus, Merluccius australis, Micromesistius australis, M. gayi and N. pulchella. A higher number of endoparasite species was recorded for Merluccius australis, Micromesistius australis and M. magellanicus, namely Anisakis sp. and Hepatoxylon trichiuri, which is the most prevalent parasite among these hosts. Aporocotyle wilhelmi and Hysterothylacium sp. were detected only in M. gayi, whereas Lepidapedon sp. was found exclusively in N. pulchella. These results suggest that fish ecology rather than host phylogeny was the most important factor for the determination of similarity in parasite composition. This result could be explained by the similar trophic patterns of hosts and by the predominance of generalist larval species among these fish parasite communities.

  15. Reduction of herbivorous fish pressure can facilitate focal algal species forestation on artificial structures.

    Science.gov (United States)

    Gianni, Fabrizio; Bartolini, Fabrizio; Airoldi, Laura; Mangialajo, Luisa

    2018-07-01

    Coastal areas have been transformed worldwide by urbanization, so that artificial structures are now widespread. Current coastal development locally depletes many native marine species, while offering limited possibilities for their expansion. Eco-engineering interventions intend to identify ways to facilitate the presence of focal species and their associated functions on artificial habitats. An important but overlooked factor controlling restoration operations is overgrazing by herbivores. The aim of this study was to quantify the effects of different potential feeders on Cystoseira amentacea, a native canopy-forming alga of the Mediterranean infralittoral fringe, and test whether manipulation of grazing pressure can facilitate the human-guided installation of this focal species on coastal structures. Results of laboratory tests and field experiments revealed that Sarpa salpa, the only strictly native herbivorous fish in the Western Mediterranean Sea, can be a very effective grazer of C. amentacea in artificial habitats, up to as far as the infralittoral fringe, which is generally considered less accessible to fishes. S. salpa can limit the success of forestation operations in artificial novel habitats, causing up to 90% of Cystoseira loss after a few days. Other grazers, such as limpets and crabs, had only a moderate impact. Future engineering operations,intended to perform forestation of canopy-forming algae on artificial structures, should consider relevant biotic factors, such as fish overgrazing, identifying cost-effective techniques to limit their impact, as is the usual practice in restoration programmes on land. Copyright © 2018 Elsevier Ltd. All rights reserved.

  16. Evidence of population resistance to extreme low flows in a fluvial-dependent fish species

    Science.gov (United States)

    Katz, Rachel A.; Freeman, Mary C.

    2015-01-01

    Extreme low streamflows are natural disturbances to aquatic populations. Species in naturally intermittent streams display adaptations that enhance persistence during extreme events; however, the fate of populations in perennial streams during unprecedented low-flow periods is not well-understood. Biota requiring swift-flowing habitats may be especially vulnerable to flow reductions. We estimated the abundance and local survival of a native fluvial-dependent fish species (Etheostoma inscriptum) across 5 years encompassing historic low flows in a sixth-order southeastern USA perennial river. Based on capturemark-recapture data, the study shoal may have acted as a refuge during severe drought, with increased young-of-the-year (YOY) recruitment and occasionally high adult immigration. Contrary to expectations, summer and autumn survival rates (30 days) were not strongly depressed during low-flow periods, despite 25%-80% reductions in monthly discharge. Instead, YOY survival increased with lower minimum discharge and in response to small rain events that increased low-flow variability. Age-1+ fish showed the opposite pattern, with survival decreasing in response to increasing low-flow variability. Results from this population dynamics study of a small fish in a perennial river suggest that fluvial-dependent species can be resistant to extreme flow reductions through enhanced YOY recruitment and high survival

  17. Mercury bioaccumulation and risk to three waterbird foraging guilds is influenced by foraging ecology and breeding stage

    International Nuclear Information System (INIS)

    Eagles-Smith, Collin A.; Ackerman, Joshua T.; De La Cruz, Susan E.W.; Takekawa, John Y.

    2009-01-01

    We evaluated mercury (Hg) in five waterbird species representing three foraging guilds in San Francisco Bay, CA. Fish-eating birds (Forster's and Caspian terns) had the highest Hg concentrations in thier tissues, but concentrations in an invertebrate-foraging shorebird (black-necked stilt) were also elevated. Foraging habitat was important for Hg exposure as illustrated by within-guild differences, where species more associated with marshes and salt ponds had higher concentrations than those more associated with open-bay and tidal mudflats. Importantly, Hg concentrations increased with time spent in the estuary. Surf scoter concentrations tripled over six months, whereas Forster's terns showed an up to 5-fold increase between estuary arrival and breeding. Breeding waterbirds were at elevated risk of Hg-induced reproductive impairment, particularly Forster's terns, in which 48% of breeding birds were at high risk due to their Hg levels. Our results highlight the importance of habitat and exposure timing, in addition to trophic position, on waterbird Hg bioaccumulation and risk. - The influence of foraging habitat, trophic position, and exposure timing on mercury bioaccumulation and risk to reproduction is evaluated in three waterbird guilds.

  18. Rapidly shifting baselines in Yangtze fishing communities and local memory of extinct species.

    Science.gov (United States)

    Turvey, Samuel T; Barrett, Leigh A; Yujiang, Hao; Lei, Zhang; Xinqiao, Zhang; Xianyan, Wang; Yadong, Huang; Kaiya, Zhou; Hart, Tom; Ding, Wang

    2010-06-01

    Local ecological knowledge can provide a unique source of data for conservation, especially in efforts to investigate the status of rare or possibly extinct species, but it is unlikely to remain constant over time. Loss of perspective about past ecological conditions caused by lack of communication between generations may create "shifting baseline syndrome," in which younger generations are less aware of local species diversity or abundance in the recent past. This phenomenon has been widely discussed, but has rarely been examined quantitatively. We present new evidence of shifting baselines in local perception of regional species declines and on the duration of "community memory" of extinct species on the basis of extensive interviews with fishers in communities across the middle-lower Yangtze basin. Many Yangtze species have experienced major declines in recent decades, and the Yangtze River dolphin or baiji (Lipotes vexillifer) and Yangtze paddlefish (Psephurus gladius) may have become extinct during the 21(st) century. Although informants across all age classes were strongly aware of the Yangtze ecosystem's escalating resource depletion and environmental degradation, older informants were more likely to recognize declines in two commercially important fish species, Reeves' shad (Tenualosa reevesii) and Yangtze pufferfish (Takifugu fasciatus), and to have encountered baiji and paddlefish in the past. Age was also a strong predictor of whether informants had even heard of baiji or paddlefish, with younger informants being substantially less likely to recognize either species. A marked decrease in local knowledge about the Yangtze freshwater megafauna matched the time of major population declines of these species from the 1970s onwards, and paddlefish were already unknown to over 70% of all informants below the age of 40 and to those who first started fishing after 1995. This rapid rate of cultural baseline shift suggests that once even megafaunal species cease to

  19. Ecomorphological correlates of twenty dominant fish species of Amazonian floodplain lakes

    Directory of Open Access Journals (Sweden)

    F. K. Siqueira-Souza

    Full Text Available Abstract Fishes inhabiting Amazonian floodplain lakes exhibits a great variety of body shape, which was a key advantage to colonize the several habitats that compose these areas adjacent to the large Amazon rivers. In this paper, we did an ecomorphological analysis of twenty abundant species, sampled in May and August 2011, into two floodplain lakes of the lower stretch of the Solimões River. The analysis detected differences among species, which could be probably associated with swimming ability and habitat use preferences.

  20. [Species and size composition of fishes in Barra de Navidad lagoon, Mexican central Pacific].

    Science.gov (United States)

    González-Sansón, Gaspar; Aguilar-Betancourt, Consuelo; Kosonoy-Aceves, Daniel; Lucano-Ramírez, Gabriela; Ruiz-Ramírez, Salvador; Flores-Ortega, Juan Ramón; Hinojosa-Larios, Angel; de Asís Silva-Bátiz, Francisco

    2014-03-01

    Coastal lagoons are considered important nursery areas for many coastal fishes. Barra de Navidad coastal lagoon (3.76km2) is important for local economy as it supports tourism development and artisanal fisheries. However, the role of this lagoon in the dynamics of coastal fish populations is scarcely known. Thus, the objectives of this research were: to characterize the water of the lagoon and related weather conditions, to develop a systematic list of the ichthyofauna, and to estimate the proportion of juveniles in the total number of individuals captured of most abundant species. Water and fish samples were collected between March 2011 and February 2012. Physical and chemical variables were measured in rainy and dry seasons. Several fishing gears were used including a cast net, beach purse seine and gillnets of four different mesh sizes. Our results showed that the lagoon is most of the time euhaline (salinity 30-40ups), although it can be mixopolyhaline (salinity 18-30ups) during short periods. Chlorophyll and nutrients concentrations suggested eutrophication in the lagoon. Mean water temperature changed seasonally from 24.9 degrees C (April, high tide) to 31.4 degrees C (October, low tide). Considering ichthyofauna species, a total of 36 448 individuals of 92 species were collected, 31 of them adding up to 95% of the total of individuals caught. Dominant species were Anchoa spp. (44.6%), Diapterus peruvianus (10.5%), Eucinostomus currani (8.1%), Cetengraulis mysticetus (7.8%), Mugil curema (5.2%) and Opisthonema libertate (4.5%). The lagoon is an important juvenile habitat for 22 of the 31 most abundant species. These included several species of commercial importance such as snappers (Lutjanus argentiventris, L. colorado and L. novemfasciatus), snook (Centropomus nigrescens) and white mullet (Mugil curema). Other four species seem to use the lagoon mainly as adults. This paper is the first contribution on the composition of estuarine ichthyofauna in Jalisco