Modeling tribal exposures to methyl mercury from fish consumption

EPA Science Inventory

Exposure assessment and risk management considerations for tribal fish consumption are different than for the general U.S. population because of higher fish intake from subsistence fishing and/or from unique cultural practices. This research summarizes analyses of available data ...

Predator-induced phenotypic plasticity of shape and behavior: parallel and unique patterns across sexes and species

PubMed Central

Kinnison, Michael T.

2017-01-01

Abstract Phenotypic plasticity is often an adaptation of organisms to cope with temporally or spatially heterogenous landscapes. Like other adaptations, one would predict that different species, populations, or sexes might thus show some degree of parallel evolution of plasticity, in the form of parallel reaction norms, when exposed to analogous environmental gradients. Indeed, one might even expect parallelism of plasticity to repeatedly evolve in multiple traits responding to the same gradient, resulting in integrated parallelism of plasticity. In this study, we experimentally tested for parallel patterns of predator-mediated plasticity of size, shape, and behavior of 2 species and sexes of mosquitofish. Examination of behavioral trials indicated that the 2 species showed unique patterns of behavioral plasticity, whereas the 2 sexes in each species showed parallel responses. Fish shape showed parallel patterns of plasticity for both sexes and species, albeit males showed evidence of unique plasticity related to reproductive anatomy. Moreover, patterns of shape plasticity due to predator exposure were broadly parallel to what has been depicted for predator-mediated population divergence in other studies (slender bodies, expanded caudal regions, ventrally located eyes, and reduced male gonopodia). We did not find evidence of phenotypic plasticity in fish size for either species or sex. Hence, our findings support broadly integrated parallelism of plasticity for sexes within species and less integrated parallelism for species. We interpret these findings with respect to their potential broader implications for the interacting roles of adaptation and constraint in the evolutionary origins of parallelism of plasticity in general. PMID:29491997

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

EPA Science Inventory

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 CFR 8720 - Proclamation 8720 of September 23, 2011. National Hunting and Fishing Day, 2011

Code of Federal Regulations, 2012 CFR

2012-01-01

... Hunting and Fishing Day, 2011 8720 Proclamation 8720 Presidential Documents Proclamations Proclamation 8720 of September 23, 2011 Proc. 8720 National Hunting and Fishing Day, 2011By the President of the... outdoors. As we mark National Hunting and Fishing Day, we are reminded of the uniquely American idea that...

Lost, a desert river and its native fishes: A historical perspective of the lower Colorado River

USGS Publications Warehouse

Mueller, Gordon A.; Marsh, Paul C.

2002-01-01

The Colorado River had one of the most unique fish communities in the world. Seventy-five percent of those species were found no where else in the world. Settlement of the lower basin brought dramatic changes to both the river and its native fish. Those changes began more than 120 years ago as settlers began stocking nonnative fishes. By 1930, nonnative fish had spread throughout the lower basin and replaced native communities. All resemblance of historic river conditions faded with the construction of Hoover Dam in 1935 and other large water development projects. Today, few remember what the Colorado River was really like. Seven of the nine mainstream fishes are now federally protected as endangered. Federal and state agencies are attempting to recover these fish; however, progress has been frustrated due to the severity of human impact. This report presents testimony, old descriptions, and photographs describing the changes that have taken place in hopes that it will provide managers, biologists, and the interested public a better appreciation of the environment that shaped these unique fish.

The unique karyotype of Henochilus wheatlandii, a critically endangered fish living in a fast-developing region in Minas Gerais State, Brazil.

PubMed

Silva, Priscilla C; Santos, Udson; Travenzoli, Natália M; Zanuncio, Jose C; Cioffi, Marcelo de B; Dergam, Jorge A

2012-01-01

Henochilus wheatlandii, the only species of this genus, is critically endangered and was considered extinct for over a century. The rediscovery of this fish in 1996 made it possible to study its phylogenetic relationships with other species in the subfamily Bryconinae. The aim of this study was to characterise the karyotype of H. wheatlandii. Standard staining, C-positive heterochromatin and nucleolar organiser region (NOR) banding, chromomycin A(3) staining, and fluorescent in situ hybridisation (FISH) using 5S rDNA and 18S rDNA probes were conducted on nineteen specimens collected in the Santo Antonio River, a sub-basin of the Doce River in Ferros municipality, Minas Gerais State, Brazil. Henochilus wheatlandii shared the same diploid number and chromosome morphology as other species of Bryconinae. However, its heterochromatin distribution patterns, NOR localisation, and FISH patterns revealed a cytogenetic profile unique among Neotropical Bryconinae, emphasizing the evolutionary uniqueness of this threatened species.

The Unique Karyotype of Henochilus wheatlandii, a Critically Endangered Fish Living in a Fast-Developing Region in Minas Gerais State, Brazil

PubMed Central

Silva, Priscilla C.; Santos, Udson; Travenzoli, Natália M.; Zanuncio, Jose C.; Cioffi, Marcelo de B.; Dergam, Jorge A.

2012-01-01

Henochilus wheatlandii, the only species of this genus, is critically endangered and was considered extinct for over a century. The rediscovery of this fish in 1996 made it possible to study its phylogenetic relationships with other species in the subfamily Bryconinae. The aim of this study was to characterise the karyotype of H. wheatlandii. Standard staining, C-positive heterochromatin and nucleolar organiser region (NOR) banding, chromomycin A3 staining, and fluorescent in situ hybridisation (FISH) using 5S rDNA and 18S rDNA probes were conducted on nineteen specimens collected in the Santo Antonio River, a sub-basin of the Doce River in Ferros municipality, Minas Gerais State, Brazil. Henochilus wheatlandii shared the same diploid number and chromosome morphology as other species of Bryconinae. However, its heterochromatin distribution patterns, NOR localisation, and FISH patterns revealed a cytogenetic profile unique among Neotropical Bryconinae, emphasizing the evolutionary uniqueness of this threatened species. PMID:22848754

Factors influencing movement of two migratory fishes within the tailrace of a large neotropical dam and their implications for hydropower impacts

USGS Publications Warehouse

Suzuki, F. M.; Dunham, Jason B.; Silva, L. G. M.; Alves, C. B. M.; Pompeu, P.S.

2017-01-01

Fish attempting to move upstream through hydroelectric dams can be trapped and killed in turbines. Understanding fish movement patterns can provide useful insights for how to manage dam operations to minimize fish kill in turbines. We evaluated the movements of two migratory fish (Curimba-Prochilodus argenteus and Mandi-Pimelodus maculatus) using acoustic telemetry in the tailrace of Três Marias Dam (São Francisco River, Brazil) from 31 October 2011 to 16 February 2012. The majority of tagged fish left the tailrace in less than one week; however, some individuals returned, performing several visits to the tailrace. Mandi remained longer in the tailrace than Curimba. The number of visits was influenced by diel period, turbine and spillway discharge. Although the diel period was the only important contributor to the visits performed by Curimba, the movements of Mandi were significantly influenced by three factors. We found that whereas Curimba was predominantly diurnal, Mandi showed nocturnal habits. Additionally, visits of Mandi were significantly greater during higher turbine and spillway discharge. We discuss the implications of these results for understanding fish movements in the Três Marias Dam tailrace and their potential implications for adapting hydroelectric operations to minimize fish kills.

Downhole vacuum cleans up tough fishing, milling jobs

DOE Office of Scientific and Technical Information (OSTI.GOV)

LaLande, P.; Flanders, B.

1996-02-01

A unique tool developed to effect reverse circulation downhole is being used successfully in problem milling and fishing operations where conventional techniques fail to recover junk in the hole. Jointly developed by several major operators in conjunction with Baker Oil Tools, the patented Reverse Circulating Tool (RCT) acts as a downhole vacuum cleaner, catching and retaining debris circulated from the wellbore while allowing fishing, milling and washover operations to continue uninterrupted. As described in several case histories overviewed, the unique vacuuming action efficiently cleans up junk and debris in even the most difficult fishing and milling applications. Downhole operations proceedmore » normally, but without threat of damage from milled debris. Developers hold both mechanical and method patents on the RCT.« less

All about Fish. Animal Life for Children. [Videotape].

ERIC Educational Resources Information Center

2000

There is a completely new world to discover in the oceans, lakes, and rivers--a world filled with an amazing variety of fish. While all fish live and breathe underwater, each type looks very different and develops its own unique living habits. In this videotape, students learn more about the body structures of fish as well as how they reproduce…

Spatial and temporal dynamics of commercial reef-fish fisheries on the West Florida Shelf: Understanding drivers of fleet behavior and the implications for future management

NASA Astrophysics Data System (ADS)

Cockrell, M.; Murawski, S. A.; Sanchirico, J. N.; O'Farrell, S.; Strelcheck, A.

2016-02-01

Spatial and temporal patterns of fishing activity have historically been described over relatively coarse scales or with limited datasets. However, new and innovative approaches for fisheries management will require an understanding of both species population dynamics and fleet behavior at finer spatial and temporal resolution. In this study we describe the spatial and temporal patterns of commercial reef-fish fisheries on the West Florida Shelf (WFS) from 2006-14, using a combination of on-board observer, catch logbook, and vessel satellite tracking data. The satellite tracking data is both high resolution (ie, records from each vessel at least once every hour for the duration of a trip), and required of all federally-permitted reef fish vessels in the Gulf of Mexico, making this a uniquely rich and powerful dataset. Along with spatial and temporal fishery dynamics, we quantified concomitant patterns in fishery economics and catch metrics, such as total landings and catch composition. Fishery patterns were correlated to a number of variables across the vessel, trip, and whole fleet scales, including vessel size, distance from home port, number of days at sea, and days available to fish. Notably, changes in management structure during the years examined (eg, establishment of a seasonal closed area in 2009 and implementation of an individual fishing quota system for Grouper-Tilefish in 2010), as well as emergency spatial closures during the Deepwater Horizon oil spill in 2010, enabled us to examine the impacts of specific management frameworks on the WFS reef-fish fishery. This research highlights the need to better understand the biological, economic, and social impacts within fisheries when managing for conservation and fisheries sustainability. We discuss our results in the context of a changing policy and management landscape for marine and coastal resources in the Gulf of Mexico.

Understanding the Spatial Scale of Genetic Connectivity at Sea: Unique Insights from a Land Fish and a Meta-Analysis.

PubMed

Cooke, Georgina M; Schlub, Timothy E; Sherwin, William B; Ord, Terry J

2016-01-01

Quantifying the spatial scale of population connectivity is important for understanding the evolutionary potential of ecologically divergent populations and for designing conservation strategies to preserve those populations. For marine organisms like fish, the spatial scale of connectivity is generally set by a pelagic larval phase. This has complicated past estimates of connectivity because detailed information on larval movements are difficult to obtain. Genetic approaches provide a tractable alternative and have the added benefit of estimating directly the reproductive isolation of populations. In this study, we leveraged empirical estimates of genetic differentiation among populations with simulations and a meta-analysis to provide a general estimate of the spatial scale of genetic connectivity in marine environments. We used neutral genetic markers to first quantify the genetic differentiation of ecologically-isolated adult populations of a land dwelling fish, the Pacific leaping blenny (Alticus arnoldorum), where marine larval dispersal is the only probable means of connectivity among populations. We then compared these estimates to simulations of a range of marine dispersal scenarios and to collated FST and distance data from the literature for marine fish across diverse spatial scales. We found genetic connectivity at sea was extensive among marine populations and in the case of A. arnoldorum, apparently little affected by the presence of ecological barriers. We estimated that ~5000 km (with broad confidence intervals ranging from 810-11,692 km) was the spatial scale at which evolutionarily meaningful barriers to gene flow start to occur at sea, although substantially shorter distances are also possible for some taxa. In general, however, such a large estimate of connectivity has important implications for the evolutionary and conservation potential of many marine fish communities.

Complex expression patterns of lymphocyte-specific genes during the development of cartilaginous fish implicate unique lymphoid tissues in generating an immune repertoire

NASA Technical Reports Server (NTRS)

Miracle, A. L.; Anderson, M. K.; Litman, R. T.; Walsh, C. J.; Luer, C. A.; Rothenberg, E. V.; Litman, G. W.

2001-01-01

Cartilaginous fish express canonical B and T cell recognition genes, but their lymphoid organs and lymphocyte development have been poorly defined. Here, the expression of Ig, TCR, recombination-activating gene (Rag)-1 and terminal deoxynucleosidase (TdT) genes has been used to identify roles of various lymphoid tissues throughout development in the cartilaginous fish, Raja eglanteria (clearnose skate). In embryogenesis, Ig and TCR genes are sharply up-regulated at 8 weeks of development. At this stage TCR and TdT expression is limited to the thymus; later, TCR gene expression appears in peripheral sites in hatchlings and adults, suggesting that the thymus is a source of T cells as in mammals. B cell gene expression indicates more complex roles for the spleen and two special organs of cartilaginous fish-the Leydig and epigonal (gonad-associated) organs. In the adult, the Leydig organ is the site of the highest IgM and IgX expression. However, the spleen is the first site of IgM expression, while IgX is expressed first in gonad, liver, Leydig and even thymus. Distinctive spatiotemporal patterns of Ig light chain gene expression also are seen. A subset of Ig genes is pre-rearranged in the germline of the cartilaginous fish, making expression possible without rearrangement. To assess whether this allows differential developmental regulation, IgM and IgX heavy chain cDNA sequences from specific tissues and developmental stages have been compared with known germline-joined genomic sequences. Both non-productively rearranged genes and germline-joined genes are transcribed in the embryo and hatchling, but not in the adult.

Docosahexaenoic acid (DHA): an ancient nutrient for the modern human brain.

PubMed

Bradbury, Joanne

2011-05-01

Modern humans have evolved with a staple source of preformed docosahexaenoic acid (DHA) in the diet. An important turning point in human evolution was the discovery of high-quality, easily digested nutrients from coastal seafood and inland freshwater sources. Multi-generational exploitation of seafood by shore-based dwellers coincided with the rapid expansion of grey matter in the cerebral cortex, which characterizes the modern human brain. The DHA molecule has unique structural properties that appear to provide optimal conditions for a wide range of cell membrane functions. This has particular implications for grey matter, which is membrane-rich tissue. An important metabolic role for DHA has recently been identified as the precursor for resolvins and protectins. The rudimentary source of DHA is marine algae; therefore it is found concentrated in fish and marine oils. Unlike the photosynthetic cells in algae and higher plants, mammalian cells lack the specific enzymes required for the de novo synthesis of alpha-linolenic acid (ALA), the precursor for all omega-3 fatty acid syntheses. Endogenous synthesis of DHA from ALA in humans is much lower and more limited than previously assumed. The excessive consumption of omega-6 fatty acids in the modern Western diet further displaces DHA from membrane phospholipids. An emerging body of research is exploring a unique role for DHA in neurodevelopment and the prevention of neuropsychiatric and neurodegenerative disorders. DHA is increasingly being added back into the food supply as fish oil or algal oil supplementation.

Docosahexaenoic Acid (DHA): An Ancient Nutrient for the Modern Human Brain

PubMed Central

Bradbury, Joanne

2011-01-01

Modern humans have evolved with a staple source of preformed docosahexaenoic acid (DHA) in the diet. An important turning point in human evolution was the discovery of high-quality, easily digested nutrients from coastal seafood and inland freshwater sources. Multi-generational exploitation of seafood by shore-based dwellers coincided with the rapid expansion of grey matter in the cerebral cortex, which characterizes the modern human brain. The DHA molecule has unique structural properties that appear to provide optimal conditions for a wide range of cell membrane functions. This has particular implications for grey matter, which is membrane-rich tissue. An important metabolic role for DHA has recently been identified as the precursor for resolvins and protectins. The rudimentary source of DHA is marine algae; therefore it is found concentrated in fish and marine oils. Unlike the photosynthetic cells in algae and higher plants, mammalian cells lack the specific enzymes required for the de novo synthesis of alpha-linolenic acid (ALA), the precursor for all omega-3 fatty acid syntheses. Endogenous synthesis of DHA from ALA in humans is much lower and more limited than previously assumed. The excessive consumption of omega-6 fatty acids in the modern Western diet further displaces DHA from membrane phospholipids. An emerging body of research is exploring a unique role for DHA in neurodevelopment and the prevention of neuropsychiatric and neurodegenerative disorders. DHA is increasingly being added back into the food supply as fish oil or algal oil supplementation. PMID:22254110

The coastal fishes and fisheries of the Socotra Archipelago, Yemen.

PubMed

Zajonz, Uwe; Lavergne, Edouard; Klaus, Rebecca; Krupp, Friedhelm; Aideed, Moteah Sheikh; Saeed, Fouad Naseeb

2016-04-30

The Socotra Archipelago is situated in the Gulf of Aden where tropical and "pseudo-temperate" conditions combine to create a unique marine ecosystem. The diversity, ecology, productivity and fisheries of the coastal fish assemblages are still relatively understudied and no update of the scientific knowledge existed. The islands support unique coastal and coral-associated fish assemblages in spite of the limited biogenic reef frameworks. Fish diversity is the highest among comparable Arabian eco-regions, and fish biomass productivity high too by Indian Ocean standards. The production of the once traditionally-managed small-scale fishery is severely declining and whether it is sustainable nowadays is extremely doubtful. At a time when Yemen is torn apart by a severe political and humanitarian crisis it is timely to review and update the current state of knowledge for scientists and managers, and thereby ease access to existing information, facilitating follow-on studies and evidence-based conservation and fisheries management. Copyright © 2015 Elsevier Ltd. All rights reserved.

Histamine (Scombroid) Fish Poisoning: a Comprehensive Review.

PubMed

Feng, Charles; Teuber, Suzanne; Gershwin, M Eric

2016-02-01

Histamine fish poisoning, also known as scombroid poisoning, is the most common cause of ichythyotoxicosis worldwide and results from the ingestion of histamine-contaminated fish in the Scombroidae and Scomberesocidae families, including mackerel, bonito, albacore, and skipjack. This disease was first described in 1799 in Britain and re-emerged in the medical literature in the 1950s when outbreaks were reported in Japan. The symptoms associated with histamine fish poisoning are similar to that of an allergic reaction. In fact, such histamine-induced reactions are often misdiagnosed as IgE-mediated fish allergy. Indeed, histamine fish poisoning is still an underrecognized disease. In this review, we discuss the epidemiology, pathophysiology, evaluation, and treatment of scombroid disease. Because more than 80% of fish consumed in the USA is now imported from other countries, the disease is intimately linked with the global fish trade (National Marine Fisheries Service, 2012). Preventing future scombroid outbreaks will require that fishermen, public health officials, restaurant workers, and medical professionals work together to devise international safety standards and increase awareness of the disease. The implications of scombroid poisoning go far beyond that of fish and have broader implications for the important issues of food safety.

Evolution of Gravity Receptors in the Ear

NASA Technical Reports Server (NTRS)

Popper, Arthur N. (Principal Investigator)

1996-01-01

The general status of a grant to investigate the origins and evolution of two hair cell types in the ears of a teleost fish, Astronotus ocellatus (the oscar), is presented. First, it was demonstrated that the cells in the rostral end of the saccule of the , Carassius auratus, are type 1-like, while those at the caudal end are type 2 cells. It was demonstrated that the dichotomy of hair cell types found in the utricle of the oscar is also found in the goldfish. Second, the lateral line system of the oscar was examined using gentamicin sulphate, an ototocix drug that destroys type 1- like hair cells but does not appear to damage type 2 hair cells. It was demonstrated that the hair cells found in neuromasts of lateral line canal organs were totally destroyed within 1 day of treatment, while the hair cells in free neuromasts were undamaged after 12 days of treatment. Third, it was demonstrated that the calyx, the specialized nerve ending, is not unique to amniotes and that it is present at least in the cristae of semicirular canals in goldfish. These results have demonstrated that: (1) there are multiple hair cell types in the vestibular endorgans of the ear of fishes, (2) these hair cell types are very similar to those found in the mammalian vestibular endorgans, (3) the nerve calyx is also present in fishes, and (4) multiple hair cell types and the calyx have evolved far earlier in the course of vertebrate evolution than heretofore thought. Understanding the structure of the vestibular endorgans has important implications for being able to understand how these organs respond to gravistatic, acceleration and acoustic input. The vestibular endorgans of fishes may provide an ideal system in which to analyze functional differences in hair cells. Not only are the two hair cell types similar to those found in mammals, they are located in very discrete regions in each endorgan. Thus, it is relatively easy to gain access to cells of one or the other type. The presence of two cell types in the lateral line have equally significant implications for studies of the vestibular system.

Rare Social Marketing for Sustainable Fishing in Cortes, Surigao Del Sur, Philippines

ERIC Educational Resources Information Center

Day, Brian A.; DeWan, Amielle; Cadiz, Fel Ceasar; Jakosalem-Balane, Joy; Dueñas, Vincent; Trinidad, Pedro M., Jr.

2014-01-01

Rare's approach to promoting sustainable fishing through social marketing in the Philippines is exemplified in the Cortes Pride campaign. The Cortes Pride campaign is a social marketing behavior change program that was part of a cohort of 12 similar sustainable fishing campaigns in the Philippines, all of which used a unique blend of social…

Histamine poisoning (scombroid fish poisoning): an allergy-like intoxication.

PubMed

Taylor, S L; Stratton, J E; Nordlee, J A

1989-01-01

Histamine poisoning results from the consumption of foods, typically certain types of fish and cheeses, that contain unusually high levels of histamine. Spoiled fish of the families, Scombridae and Scomberesocidae (e.g. tuna, mackerel, bonito), are commonly implicated in incidents of histamine poisoning, which leads to the common usage of the term, "scombroid fish poisoning", to describe this illness. However, certain non-scombroid fish, most notably mahi-mahi, bluefish, and sardines, when spoiled are also commonly implicated in histamine poisoning. Also, on rare occasions, cheeses especially Swiss cheese, can be implicated in histamine poisoning. The symptoms of histamine poisoning generally resemble the symptoms encountered with IgE-mediated food allergies. The symptoms include nausea, vomiting, diarrhea, an oral burning sensation or peppery taste, hives, itching, red rash, and hypotension. The onset of the symptoms usually occurs within a few minutes after ingestion of the implicated food, and the duration of symptoms ranges from a few hours to 24 h. Antihistamines can be used effectively to treat this intoxication. Histamine is formed in foods by certain bacteria that are able to decarboxylate the amino acid, histidine. However, foods containing unusually high levels of histamine may not appear to be outwardly spoiled. Foods with histamine concentrations exceeding 50 mg per 100 g of food are generally considered to be hazardous. Histamine formation in fish can be prevented by proper handling and refrigerated storage while the control of histamine formation in cheese seems dependent on insuring that histamine-producing bacteria are not present in significant numbers in the raw milk.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Peterson, Mark J; Efroymson, Rebecca Ann; Adams, Marshall

The long-term ecological recovery of an impaired stream in response to an industrial facility's pollution abatement actions and the implications of the biological monitoring effort to environmental management is the subject of this special issue of Environmental Management. This final article focuses on the synthesis of the biological monitoring program's components and methods, the efficacy of various biological monitoring techniques to environmental management, and the lessons learned from the program that might be applicable to the design and application of other programs. The focus of the 25-year program has been on East Fork Poplar Creek, an ecologically impaired stream inmore » Oak Ridge, Tennessee with varied and complex stressors from a Department of Energy facility in its headwaters. Major components of the long-term program included testing and monitoring of invertebrate and fish toxicity, bioindicators of fish health, fish contaminant accumulation, and instream communities (including periphyton, benthic macroinvertebrate, and fish). Key parallel components of the program include water chemistry sampling and data management. Multiple lines of evidence suggested positive ecological responses during three major pollution abatement periods. Based on this case study and the related literature, effective environmental management of impaired streams starts with program design that is consistent across space and time, but also adaptable to changing conditions. The biological monitoring approaches used for the program provided a strong basis for assessments of recovery from remedial actions, and the likely causes of impairment. This case study provides a unique application of multidisciplinary and quantitative techniques to address multiple and complex regulatory and programmatic goals, environmental stressors, and remedial actions.« less

MERCURY IN FISH TISSUE ACROSS THE WESTERN UNITED STATES: IMPLICATIONS OF SELENIUM INTERACTIONS

EPA Science Inventory

We collected 2,707 fish from 626 stream/river sites in 12 western USA states using a probability design to assess the spatial extent of whole fish mercury (Hg) concentrations. In all large (> 120 mm) fish, total Hg concentrations (mean µg·g-1; SD; n) in both piscivores (0.26...

Macroinvertebrates as indicators of fish absence in naturally fishless lakes

USGS Publications Warehouse

Schilling, Emily Gaenzle; Loftin, C.S.; Huryn, Alexander D.

2009-01-01

1. Little is known about native communities in naturally fishless lakes in eastern North America, a region where fish stocking has led to a decline in these habitats. 2. Our study objectives were to: (i) characterise and compare macroinvertebrate communities in fishless lakes found in two biophysical regions of Maine (U.S.A.): kettle lakes in the eastern lowlands and foothills and headwater lakes in the central and western mountains; (ii) identify unique attributes of fishless lake macroinvertebrate communities compared to lakes with fish and (iii) develop a method to efficiently identify fishless lakes when thorough fish surveys are not possible. 3. We quantified macroinvertebrate community structure in the two physiographic fishless lake types (n = 8 kettle lakes; n = 8 headwater lakes) with submerged light traps and sweep nets. We also compared fishless lake macroinvertebrate communities to those in fish-containing lakes (n = 18) of similar size, location and maximum depth. We used non-metric multidimensional scaling to assess differences in community structure and t-tests for taxon-specific comparisons between lakes. 4. Few differences in macroinvertebrate communities between the two physiographic fishless lake types were apparent. Fishless and fish-containing lakes had numerous differences in macroinvertebrate community structure, abundance, taxonomic composition and species richness. Fish presence or absence was a stronger determinant of community structure in our study than differences in physical conditions relating to lake origin and physiography. 5. Communities in fishless lakes were more speciose and abundant than in fish-containing lakes, especially taxa that are large, active and free-swimming. Families differing in abundance and taxonomic composition included Notonectidae, Corixidae, Gyrinidae, Dytiscidae, Aeshnidae, Libellulidae and Chaoboridae. 6. We identified six taxa unique to fishless lakes that are robust indicators of fish absence: Graphoderus liberus, Hesperocorixa spp., Dineutus spp., Chaoborus americanus, Notonecta insulata and Callicorixa spp. These taxa are collected most effectively with submerged light traps. 7. Naturally fishless lakes warrant conservation, because they provide habitat for a unique suite of organisms that thrive in the absence of fish predation. ?? 2008 Blackwell Publishing Ltd.

Short-term effects of wildfires on fishes in the southwestern United States, 2002: management implications

Treesearch

John N. Rinne; Codey D. Carter

2008-01-01

Summer 2002 was a season of markedly increased wildfire in the southwestern United States. Four fires affected landscapes that encompassed watersheds and streams containing fishes. Streams affected in three of the four fires were sampled for multiple factors, including fishes, to delineate the impact of fires on aquatic ecosystems in the -Southwest. All fishes were...

Spatial and Temporal Variability of Elemental Signautres in Juvenile Winter Flounder (Psuedopleuronectes americanus): Implications for Natal Connectivity

EPA Science Inventory

Elemental signatures in otoliths (fish ear-stones) have become a powerful tool in fisheries science for identifying fish migration patterns, reconstructing environmental histories, and for delineating the nursery origins of adult fish populations. Assessing connectivity between a...

Microhabitat influence on larval fish assemblages within vegetated beds: Implications for restoration

EPA Science Inventory

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

The three-dimensional structure of anosteocytic lamellated bone of fish.

PubMed

Atkins, Ayelet; Reznikov, Natalie; Ofer, Lior; Masic, Admir; Weiner, Steve; Shahar, Ron

2015-02-01

Fish represent the most diverse and numerous of the vertebrate clades. In contrast to the bones of all tetrapods and evolutionarily primitive fish, many of the evolutionarily more advanced fish have bones that do not contain osteocytes. Here we use a variety of imaging techniques to show that anosteocytic fish bone is composed of a sequence of planar layers containing mainly aligned collagen fibrils, in which the prevailing principal orientation progressively spirals. When the sequence of fibril orientations completes a rotation of around 180°, a thin layer of poorly oriented fibrils is present between it and the next layer. The thick layer of aligned fibrils and the thin layer of non-aligned fibrils constitute a lamella. Although both basic components of mammalian lamellar bone are found here as well, the arrangement is unique, and we therefore call this structure lamellated bone. We further show that the lamellae of anosteocytic fish bone contain an array of dense, small-diameter (1-4 μm) bundles of hypomineralized collagen fibrils that are oriented mostly orthogonal to the lamellar plane. Results of mechanical tests conducted on beams from anosteocytic fish bone and human cortical bone show that the fish bones are less stiff but much tougher than the human bones. We propose that the unique lamellar structure and the orthogonal hypomineralized collagen bundles are responsible for the unusual mechanical properties and mineral distribution in anosteocytic fish bone. Copyright © 2014 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Unique Features of Fish Immune Repertoires: Particularities of Adaptive Immunity Within the Largest Group of Vertebrates

PubMed Central

Sunyer, Oriol J.

2016-01-01

Fishes (i.e., teleost fishes) are the largest group of vertebrates. Although their immune system is based on the fundamental receptors, pathways, and cell types found in all groups of vertebrates, fishes show a diversity of particular features that challenge some classical concepts of immunology. In this chapter, we discuss the particularities of fish immune repertoires from a comparative perspective. We examine how allelic exclusion can be achieved when multiple Ig loci are present, how isotypic diversity and functional specificity impact clonal complexity, how loss of the MHC class II molecules affects the cooperation between T and B cells, and how deep sequencing technologies bring new insights about somatic hypermutation in the absence of germinal centers. The unique coexistence of two distinct B-cell lineages respectively specialized in systemic and mucosal responses is also discussed. Finally, we try to show that the diverse adaptations of immune repertoires in teleosts can help in understanding how somatic adaptive mechanisms of immunity evolved in parallel in different lineages across vertebrates. PMID:26537384

Percent Stomach Emptiness in Fish Collections: Sources of Variation and Study Design Implications

EPA Science Inventory

We summarized fish stomach content data from 369,000 fish from 402 species in 1,096 collections made between 1925 and 2009 and report on the percentage of individuals with empty stomachs (PES). The mean PES among all species, locations, habitats, dates, and collection methods was...

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

EPA Science Inventory

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

[Fish interferon response and its molecular regulation: a review].

PubMed

Zhang, Yibing; Gui, Jianfang

2011-05-01

Interferon response is the first line of host defense against virus infection. Recent years have witnessed tremendous progress in understanding of fish innate response to virus infection, especially in fish interferon antiviral response. A line of fish genes involved in interferon antiviral response have been identified and functional studies further reveal that fish possess an IFN antiviral system similar to mammals. However, fish virus-induced interferon genes contain introns similar to mammalian type III interferon genes although they encode proteins similar to type I interferons, which makes it hard to understand the evolution of vertebrate interferon genes directly resulting in a debate on nomenclature of fish interferon genes. Actually, fish display some unique mechanisms underlying interferon antiviral response. This review documents the recent progress on fish interferon response and its molecular mechanism.

Conserving Shorebirds on Department of Defense Lands

DTIC Science & Technology

2007-06-01

Fish & Wildlife Service and the National Fish and Wildlife Foundation. The booklet also has benefited from advice of Chris Eberly (Department of...as noted, courtesy of U. S . Fish and Wildlife Service Digital Library System (http://images.fws.gov/) Whimbrel, page 5, courtesy of Richard...biologists have a unique opportunity to manage wetland and upland habitat in ways that benefit wildlife populations and help to reverse the rapid

Biological relevance of streamflow metrics: Regional and national perspectives

USGS Publications Warehouse

Carlisle, Daren M.; Grantham, Theodore E.; Eng, Kenny; Wolock, David M.

2017-01-01

Protecting the health of streams and rivers requires identifying ecologically significant attributes of the natural flow regime. Streamflow regimes are routinely quantified using a plethora of hydrologic metrics (HMs), most of which have unknown relevance to biological communities. At regional and national scales, we evaluated which of 509 commonly used HMs were associated with biological indicators of fish and invertebrate community integrity. We quantified alteration of each HM by using statistical models to predict site-specific natural baseline values for each of 728 sites across the USA where streamflow monitoring data were available concurrent with assessments of invertebrate or fish community integrity. We then ranked HMs according to their individual association with biological integrity based on random forest models that included HMs and other relevant covariates, such as land cover and stream chemistry. HMs were generally the most important predictors of biological integrity relative to the covariates. At a national scale, the most influential HMs were measures of depleted high flows, homogenization of flows, and erratic flows. Unique combinations of biologically relevant HMs were apparent among regions. We discuss the implications of our findings to the challenge of selecting HMs for streamflow research and management.

Dietary fat and fiber interact to uniquely modify global histone post-translational epigenetic programming in a rat colon cancer progression model.

PubMed

Triff, Karen; McLean, Mathew W; Callaway, Evelyn; Goldsby, Jennifer; Ivanov, Ivan; Chapkin, Robert S

2018-04-16

Dietary fermentable fiber generates short-chain fatty acids (SCFA), e.g., butyrate, in the colonic lumen which serves as a chemoprotective histone deacetylase inhibitor and/or as an acetylation substrate for histone acetylases. In addition, n-3 polyunsaturated fatty acids (n-3 PUFA) in fish oil can affect the chromatin landscape by acting as ligands for tumor suppressive nuclear receptors. In an effort to gain insight into the global dimension of post-translational modification of histones (including H3K4me3 and H3K9ac) and clarify the chemoprotective impact of dietary bioactive compounds on transcriptional control in a preclinical model of colon cancer, we generated high-resolution genome-wide RNA (RNA-Seq) and "chromatin-state" (H3K4me3-seq and H3K9ac-seq) maps for intestinal (epithelial colonocytes) crypts in rats treated with a colon carcinogen and fed diets containing bioactive (i) fish oil, (ii) fermentable fiber (a rich source of SCFA), (iii) a combination of fish oil plus pectin or (iv) control, devoid of fish oil or pectin. In general, poor correlation was observed between differentially transcribed (DE) and enriched genes (DERs) at multiple epigenetic levels. The combinatorial diet (fish oil + pectin) uniquely affected transcriptional profiles in the intestinal epithelium, e.g., upregulating lipid catabolism and beta-oxidation associated genes. These genes were linked to activated ligand-dependent nuclear receptors associated with n-3 PUFA and were also correlated with the mitochondrial L-carnitine shuttle and the inhibition of lipogenesis. These findings demonstrate that the chemoprotective fish oil + pectin combination diet uniquely induces global histone state modifications linked to the expression of chemoprotective genes. This article is protected by copyright. All rights reserved. © 2018 UICC.

Mate choice and body pattern variations in the Crown Butterfly fish Chaetodon paucifasciatus (Chaetodontidae)

PubMed Central

Levy, Keren; Lerner, Amit; Shashar, Nadav

2014-01-01

ABSTRACT Mate choice is an important ecological behavior in fish, and is often based on visual cues of body patterns. The Crown Butterfly fish Chaetodon paucifasciatus (Chaetodontidae) is a monogamist, territorial species; it swims in close proximity to its partner throughout most of its life. This species is characterized by a pattern of 6–8 vertical black stripes on a white background, on both sides of its body. Our aim was to define spatial features (variations) in body patterns by evaluating the level of dissimilarity between both sides of each individual fish, and the level of dissimilarity between patterns of different individuals. In addition, we tested whether the fish are attracted to or reject specific features of the body patterns. Features were defined and counted using photographs of body patterns. Attraction to or rejection of specific features were tested behaviorally using a dual-choice experiment of video animations of individuals swimming over a coral-reef background. We found that the patterns of each fish and sides of the body were no less dissimilar, compared intraspecificly to other fish, and that each side pattern was unique and distinguishable. Variations in the patterns occurred mostly in the last three posterior stripes. Individuals were mainly attracted to conspecifics with multiple crossing patterns (two or more consecutive crossings), and rejected patterns with holes. Our results suggest that in this species the unique body pattern of each fish is used for conspecific identification of mates and intruders. PMID:25432516

Ciguatera Fish Poisoning

MedlinePlus

... be adversely affected by toxic or harmful marine algae. + Causative algae implicated, not confirmed. Medical Community Ciguatera Fish Poisoning ... Contact Us | Related Links | Site Map The Harmful Algae Page is supported by a National Oceanic and ...

Rapid changes in small fish mercury concentrations in estuarine wetlands: Implications for wildlife risk and monitoring programs

USGS Publications Warehouse

Eagles-Smith, Collin A.; Ackerman, Joshua T.

2009-01-01

Small fish are commonly used to assess mercury (Hg) risk to wildlife and monitor Hg in wetlands. However, limited research has evaluated short-term Hg variability in small fish, which can have important implications for monitoring programs and risk assessment. We conducted a time-series study of Hg concentrations in two small fish species representing benthic (longjaw mudsuckers [Gillichthys mirabilis]) and pelagic (threespine sticklebacks [Gasterosteus aculeatus]) food-webs within three wetland habitats in San Francisco Bay Estuary. We simultaneously monitored prey deliveries, nest initiation, and chick hatching dates of breeding Forster's terns (Sterna forsteri), the most abundant nesting piscivore in the region. Mudsuckers and sticklebacks were the predominant prey fish, comprising 36% and 25% of tern diet, and Hg concentrations averaged (geometric mean ?? SE, ??g/g dw) 0.44 ?? 0.01 and 0.68 ?? 0.03, respectively. Fish Hg concentrations varied substantially over time following a quadratic form in both species, increasing 40% between March and May then decreasing 40% between May and July. Importantly, Forster's terns initiated 68% of nests and 31% of chicks hatched during the period of peak Hg concentrations in prey fish. These results illustrate the importance of short-term temporal variation in small fish Hg concentrations for both Hg monitoring programs and assessing wildlife risk.

Fish and chips? Implanted transmitters help map the endangered pallid sturgeon

USGS Publications Warehouse

Chojnacki, Kimberly; DeLonay, Aaron

2011-01-01

With a flattened snout, long slender tail and rows of bony plates lining its body, the pallid sturgeon (Scaphirhynchus albus) has a unique, almost pre-historic, appearance. This endangered fish is native to the muddy, free-flowing waters of the Missouri River.

The Gills of Reef Fish Support a Distinct Microbiome Influenced by Host-Specific Factors.

PubMed

Pratte, Zoe A; Besson, Marc; Hollman, Rebecca D; Stewart, Frank J

2018-05-01

Teleost fish represent the most diverse of the vertebrate groups and play important roles in food webs, as ecosystem engineers, and as vectors for microorganisms. However, the microbial ecology of fishes remains underexplored for most host taxa and for certain niches on the fish body. This is particularly true for the gills, the key sites of respiration and waste exchange in fishes. Here we provide a comprehensive analysis of the gill microbiome. We focus on ecologically diverse taxa from coral reefs around Moorea, sampling the gills and intestines of adults and juveniles representing 15 families. The gill microbiome composition differed significantly from that of the gut for both adults and juveniles, with fish-associated niches having lower alpha diversity values and higher beta diversity values than those for seawater, sediment, and alga-associated microbiomes. Of ∼45,000 operational taxonomic units (OTUs) detected across all samples, 11% and 13% were detected only in the gill and the intestine, respectively. OTUs most enriched in the gill included members of the gammaproteobacterial genus Shewanella and the family Endozoicimonaceae In adult fish, both gill and intestinal microbiomes varied significantly among host species grouped by diet category. Gill and intestinal microbiomes from the same individual were more similar to one another than to gill and intestinal microbiomes from different individuals. These results demonstrate that distinct body sites are jointly influenced by host-specific organizing factors operating at the level of the host individual. The results also identify taxonomic signatures unique to the gill and the intestine, confirming fish-associated niches as distinct reservoirs of marine microbial diversity. IMPORTANCE Fish breathe and excrete waste through their gills. The gills are also potential sites of pathogen invasion and colonization by other microbes. However, we know little about the microbial communities that live on the gill and the factors shaping their diversity. Focusing on ecologically distinct types of coral reef fish, we provide a comprehensive analysis of the fish gill microbiome. By comparison to microbiomes of the gut and the surrounding environment, we identify microbes unique to the gill niche. These microbes may be targets for further studies to determine the contribution of the microbiome to waste exchange or host immunity. We also show that despite exhibiting a unique taxonomic signature, the gill microbiome is influenced by factors that also influence the gut microbiome. These factors include the specific identity of the host individual. These results suggest basic principles describing how association with fishes structures the composition of microbial communities. Copyright © 2018 American Society for Microbiology.

Bioinspired fabrication and characterization of a synthetic fish skin for the protection of soft materials.

PubMed

Funk, Natasha; Vera, Marc; Szewciw, Lawrence J; Barthelat, Francois; Stoykovich, Mark P; Vernerey, Franck J

2015-03-18

The scaled skin of fish is a high-performance natural armor that represents a source of inspiration for novel engineering designs. In this paper, we present a biomimetic fish skin material, fabricated with a design and components that are simple, that achieves many of the advantageous attributes of natural materials, including the unique combination of flexibility and mechanical robustness. The bioinspired fish skin material is designed to replicate the structural, mechanical, and functional aspects of a natural teleost fish skin comprised of leptoid-like scales, similar to that of the striped red mullet Mullus surmuletus. The man-made fish skin material consists of a low-modulus elastic mesh or "dermis" layer that holds rigid, plastic scales. The mechanics of the synthetic material is characterized under in-plane, bending, and indentation modes of deformation and is successfully described by theoretical deformation models that have been developed. This combined experimental and modeling approach elucidates the critical mechanisms by which the composite material achieves its unique properties and provides design rules that allow for the engineering of scaled skins. Such artificial scaled skins that are flexible, lightweight, transparent, and robust under mechanical deformation may thus have potential as thin protective coatings for soft materials.

Poly- and perfluoroalkylated substances (PFASs) in water, sediment and fish muscle tissue from Lake Tana, Ethiopia and implications for human exposure.

PubMed

Ahrens, Lutz; Gashaw, Habiba; Sjöholm, Margareta; Gebrehiwot, Solomon Gebreyohannis; Getahun, Abebe; Derbe, Ermias; Bishop, Kevin; Åkerblom, Staffan

2016-12-01

Lake Tana is Ethiopia's largest lake and there are plans to increase the harvest of fish from the lake. The objective of this study was to assess the levels of poly- and perfluoroalkyl substances (PFASs) in different compartments of the lake (water, sediment, and fish muscle tissue), and its implications for human exposure. The results showed higher PFAS concentrations in piscivorous fish species (Labeobarbus megastoma and Labeobarbus gorguari) than non-piscivorous species (Labeobarbus intermedius, Oreochromis niloticus and Clarias gariepinus) and also spatial distribution similarities. The ∑PFAS concentrations ranged from 0.073 to 5.6 ng L -1 (on average, 2.9 ng L -1 ) in surface water, 0.22-0.55 ng g -1 dry weight (dw) (on average, 0.30 ng g -1 dw) in surface sediment, and non-detected to 5.8 ng g -1 wet weight (ww) (on average, 1.2 ng g -1 ww) in all fish species. The relative risk (RR) indicates that the consumption of fish contaminated with perfluorooctane sulfonate (PFOS) will likely not cause any harmful effects for the Ethiopian fish eating population. However, mixture toxicity of the sum of PFASs, individual fish consumption patterns and increasing fish consumption are important factors to consider in future risk assessments. Copyright © 2016 Elsevier Ltd. All rights reserved.

Outbreak of scombroid fish poisoning, Taiwan.

PubMed Central

Chen, K T; Malison, M D

1987-01-01

Fish implicated in outbreaks of scombroid poisoning have usually undergone prolonged storage at an inadequate temperature. We report an outbreak of scombroid poisoning in which fish stored on ice for two days caused illness after standing at room temperature for only three to four hours; fish from the same catch did not cause illness after standing at room temperature only one hour. This outbreak suggests scombrotoxins may be produced more rapidly than previously thought possible. PMID:3631369

Outbreak of scombroid fish poisoning, Taiwan.

PubMed

Chen, K T; Malison, M D

1987-10-01

Fish implicated in outbreaks of scombroid poisoning have usually undergone prolonged storage at an inadequate temperature. We report an outbreak of scombroid poisoning in which fish stored on ice for two days caused illness after standing at room temperature for only three to four hours; fish from the same catch did not cause illness after standing at room temperature only one hour. This outbreak suggests scombrotoxins may be produced more rapidly than previously thought possible.

Results of EPA’s Assessment of Fish Tissue from U.S. Rivers for Selenium with Implications for Aquatic Life and Human Health

EPA Science Inventory

EPA’s Office of Water and Office of Research and Development collaborated to conduct the first statistically based survey of contaminants in fish fillets from U.S. rivers. This national fish survey was conducted under the framework of EPA’s National Rivers and Streams Assessment ...

The natural armors of fish: A comparison of the lamination pattern and structure of scales

DOE Office of Scientific and Technical Information (OSTI.GOV)

Murcia, Sandra; Lavoie, Ellen; Linley, Tim

Fish scales exhibit a unique balance of flexibility, strength and toughness, which is essential to provide protection without encumbering locomotion. Although the mechanical behavior and structure of this natural armor are of recent interest, a comparison of these qualities from scales of different fish species has not been reported. In this investigation the armor of fish with different locomotion, size and protection needs were analyzed. Scales from the Arapaima gigas, the tarpon (Megalops atlanticus) and the carp (Cyprinus carpio) were compared in terms of the stacking sequence of individual plies and their microstructure. The scales were also compared with respectmore » to anatomical position to distinguish site-specific functional differences. Results show that the lamination sequence of plies for the carp and tarpon exhibit a Bouligand structure with relative rotation of 75° between consecutive plies. The arapaima scales exhibit a cross-ply structure, with 90° rotation between adjacent plies. In addition, results indicate that the volume fraction of reinforcement, the number of plies and the variations in thickness with anatomical position are unique amongst the three fish. These characteristics should be considered in evaluations focused on the mechanical behavior.« less

The alligator gut microbiome and implications for archosaur symbioses

PubMed Central

Keenan, Sarah W.; Engel, Annette Summers; Elsey, Ruth M.

2013-01-01

Among vertebrate gastrointestinal microbiome studies, complete representation of taxa is limited, particularly among reptiles. Here, we provide evidence for previously unrecognized host-microbiome associations along the gastrointestinal tract from the American alligator, a crown archosaur with shared ancestry to extinct taxa, including dinosaurs. Microbiome compositional variations reveal that the digestive system consists of multiple, longitudinally heterogeneous microbiomes that strongly correlate to specific gastrointestinal tract organs, regardless of rearing histories or feeding status. A core alligator gut microbiome comprised of Fusobacteria, but depleted in Bacteroidetes and Proteobacteria common to mammalians, is compositionally unique from other vertebrate gut microbiomes, including other reptiles, fish, and herbivorous and carnivorous mammals. As such, modern alligator gut microbiomes advance our understanding of archosaur gut microbiome evolution, particularly if conserved host ecology has retained archosaur-specific symbioses over geologic time. PMID:24096888

Unique molecular properties of superoxide dismutase from teleost fish skin.

PubMed

Nakano, T; Sato, M; Takeuchi, M

1995-02-27

A unique Cu,Zn-SOD was found and isolated from plaice Paralichthys olivaceus skin. Surprisingly, the properties of purified fish skin SOD were very different from those of SOD from other sources reported so far. The purified SOD was composed of four same subunits of 16 kDa and the molecular weight of the native SOD was found to be around 65 kDa. The dominant amino acids of the SOD were Ser, Thr, Pro and Glu. Above 70 degrees C, thermostability of the SOD was much lower than that of bovine erythrocyte Cu,Zn-SOD.

50 CFR 680.21 - Crab harvesting cooperatives.

Code of Federal Regulations, 2011 CFR

2011-10-01

...) Minimum number of members. Each crab harvesting cooperative must include at least four unique QS holding... IFQ permit issued to the crab harvesting cooperative for the current fishing season. (2) Transfer of... voluntary. A crab harvesting cooperative is not required to add or remove members during the fishing season...

50 CFR 680.21 - Crab harvesting cooperatives.

Code of Federal Regulations, 2012 CFR

2012-10-01

...) Minimum number of members. Each crab harvesting cooperative must include at least four unique QS holding... IFQ permit issued to the crab harvesting cooperative for the current fishing season. (2) Transfer of... voluntary. A crab harvesting cooperative is not required to add or remove members during the fishing season...

The economic implications of changing regulations for deep sea fishing under the European Common Fisheries Policy: UK case study.

PubMed

Mangi, Stephen C; Kenny, Andrew; Readdy, Lisa; Posen, Paulette; Ribeiro-Santos, Ana; Neat, Francis C; Burns, Finlay

2016-08-15

Economic impact assessment methodology was applied to UK fisheries data to better understand the implications of European Commission proposal for regulations to fishing for deep-sea stocks in the North-East Atlantic (EC COM 371 Final 2012) under the Common Fisheries Policy (CFP). The aim was to inform the on-going debate to develop the EC proposal, and to assist the UK fishing industry and Government in evaluating the most effective options to manage deep sea fish stocks. Results indicate that enforcing the EC proposal as originally drafted results in a number of implications for the UK fleet. Because of the proposed changes to the list of species defined as being deep sea species, and a new definition of what constitutes a vessel targeting deep sea species, a total of 695 active UK fishing vessels would need a permit to fish for deep sea species. However, due to existing and capped capacity limits many vessels would potentially not be able to obtain such a permit. The economic impact of these changes from the status quo reveals that in the short term, landings would decrease by 6540 tonnes, reducing gross value added by £3.3 million. Alternative options were also assessed that provide mitigation measures to offset the impacts of the proposed regulations whilst at the same time providing more effective protection of deep sea Vulnerable Marine Ecosystems (VMEs). The options include setting a 400m depth rule that identifies a depth beyond which vessels would potentially be classified as fishing for deep sea species and designating 'core areas' for deep sea fishing at depths>400m to minimise the risk of further impacts of bottom fishing gear on deep sea habitats. Applying a 400m depth limit and 'core fishing' area approach deeper than 400m, the impact of the EC proposal would essentially be reduced to zero, that is, on average no vessels (using the status quo capacity baseline) would be impacted by the proposal. Copyright © 2016 Elsevier B.V. All rights reserved.

Spatiotemporal Distribution and Assemblages of Fishes below the Lowermost Dam in Protected Reach in the Yangtze River Main Stream: Implications for River Management.

PubMed

Li, Junyi; Zhang, Hui; Lin, Danqing; Wu, Jinming; Wang, Chengyou; Xie, Xuan; Wei, Qiwei

2016-01-01

Now more and more ecologists concern about the impacts of dam construction on fish. However, studies of fishes downstream Gezhouba Dam were rarely reported except Chinese sturgeon ( Acipenser sinensis Gray). In this study, catch investigations and five hydroacoustic detections were completed from 2015 to 2016 to understand the distribution, size, and categories of fishes and their relationship with the environmental factors below Gezhouba Dam in protected reach in the Yangtze River main stream. Results showed significant differences in fish distribution and TS (target strength) between wet and flood seasons. Mean TS in five hydroacoustic detections were -59.98 dB, -54.70 dB, -56.16 dB, -57.90 dB, and -59.17 dB, respectively, and dominant fish species are Coreius guichenoti (Bleeker), Siniperca chuatsi (Basilewsky), and Pelteobagrus vachelli (Richardson). In the longitudinal direction, fish preferred to stay in some specific sections like reaches 2, 4, 7, 8, 11, and 16. Since hydrology factors change greatly in different seasons, environmental characteristics vary along the reaches, and human activities play an important role in the fish behavior, it is concluded that great cross-season changes in hydrology lead to the differences in TS and fish assemblages and that geography characteristics, especially channel geography, together with human activities influence fish longitudinal distribution. This finding provides basic knowledge of spatiotemporal distribution and assemblages of fishes in the extended reaches downstream Gezhouba Dam. In addition, it offers implications for river management. It could also serve as reference of future research on fish habitat.

Spatiotemporal Distribution and Assemblages of Fishes below the Lowermost Dam in Protected Reach in the Yangtze River Main Stream: Implications for River Management

PubMed Central

Li, Junyi; Zhang, Hui; Lin, Danqing; Wu, Jinming; Wang, Chengyou; Xie, Xuan

2016-01-01

Now more and more ecologists concern about the impacts of dam construction on fish. However, studies of fishes downstream Gezhouba Dam were rarely reported except Chinese sturgeon (Acipenser sinensis Gray). In this study, catch investigations and five hydroacoustic detections were completed from 2015 to 2016 to understand the distribution, size, and categories of fishes and their relationship with the environmental factors below Gezhouba Dam in protected reach in the Yangtze River main stream. Results showed significant differences in fish distribution and TS (target strength) between wet and flood seasons. Mean TS in five hydroacoustic detections were −59.98 dB, −54.70 dB, −56.16 dB, −57.90 dB, and −59.17 dB, respectively, and dominant fish species are Coreius guichenoti (Bleeker), Siniperca chuatsi (Basilewsky), and Pelteobagrus vachelli (Richardson). In the longitudinal direction, fish preferred to stay in some specific sections like reaches 2, 4, 7, 8, 11, and 16. Since hydrology factors change greatly in different seasons, environmental characteristics vary along the reaches, and human activities play an important role in the fish behavior, it is concluded that great cross-season changes in hydrology lead to the differences in TS and fish assemblages and that geography characteristics, especially channel geography, together with human activities influence fish longitudinal distribution. This finding provides basic knowledge of spatiotemporal distribution and assemblages of fishes in the extended reaches downstream Gezhouba Dam. In addition, it offers implications for river management. It could also serve as reference of future research on fish habitat. PMID:27843943

Fish as major carbonate mud producers and missing components of the tropical carbonate factory

USGS Publications Warehouse

Perry, C.T.; Salter, M.A.; Harborne, A.R.; Crowley, S.F.; Jelks, H.L.; Wilson, R.W.

2011-01-01

Carbonate mud is a major constituent of recent marine carbonate sediments and of ancient limestones, which contain unique records of changes in ocean chemistry and climate shifts in the geological past. However, the origin of carbonate mud is controversial and often problematic to resolve. Here we show that tropical marine fish produce and excrete various forms of precipitated (nonskeletal) calcium carbonate from their guts ("low" and "high" Mg-calcite and aragonite), but that very fine-grained (mostly <2 ??m) high Mg-calcite crystallites (i.e., >4 mole % MgCO3) are their dominant excretory product. Crystallites from fish are morphologically diverse and species-specific, but all are unique relative to previously known biogenic and abiotic sources of carbonate within open marine systems. Using site specific fish biomass and carbonate excretion rate data we estimate that fish produce ???6.1 ?? 106 kg CaCO3/year across the Bahamian archipelago, all as mud-grade (the <63 ??m fraction) carbonate and thus as a potential sediment constituent. Estimated contributions from fish to total carbonate mud production average ???14% overall, and exceed 70% in specific habitats. Critically, we also document the widespread presence of these distinctive fish-derived carbonates in the finest sediment fractions from all habitat types in the Bahamas, demonstrating that these carbonates have direct relevance to contemporary carbonate sediment budgets. Fish thus represent a hitherto unrecognized but significant source of fine-grained carbonate sediment, the discovery of which has direct application to the conceptual ideas of how marine carbonate factories function both today and in the past.

Fish as major carbonate mud producers and missing components of the tropical carbonate factory

USGS Publications Warehouse

Perry, Chris T.; Salter, Michael A.; Harborne, Alastair R.; Crowley, Stephen F.; Jelks, Howard L.; Wilson, Rod W.

2011-01-01

Carbonate mud is a major constituent of recent marine carbonate sediments and of ancient limestones, which contain unique records of changes in ocean chemistry and climate shifts in the geological past. However, the origin of carbonate mud is controversial and often problematic to resolve. Here we show that tropical marine fish produce and excrete various forms of precipitated (nonskeletal) calcium carbonate from their guts ("low" and "high" Mg-calcite and aragonite), but that very fine-grained (mostly 4 mole % MgCO3) are their dominant excretory product. Crystallites from fish are morphologically diverse and species-specific, but all are unique relative to previously known biogenic and abiotic sources of carbonate within open marine systems. Using site specific fish biomass and carbonate excretion rate data we estimate that fish produce ~6.1 x 106 kg CaCO3/year across the Bahamian archipelago, all as mud-grade (the <63 μm fraction) carbonate and thus as a potential sediment constituent. Estimated contributions from fish to total carbonate mud production average ~14% overall, and exceed 70% in specific habitats. Critically, we also document the widespread presence of these distinctive fish-derived carbonates in the finest sediment fractions from all habitat types in the Bahamas, demonstrating that these carbonates have direct relevance to contemporary carbonate sediment budgets. Fish thus represent a hitherto unrecognized but significant source of fine-grained carbonate sediment, the discovery of which has direct application to the conceptual ideas of how marine carbonate factories function both today and in the past.

Measuring and tracking eye movements of a behaving archer fish by real-time stereo vision.

PubMed

Ben-Simon, Avi; Ben-Shahar, Ohad; Segev, Ronen

2009-11-15

The archer fish (Toxotes chatareus) exhibits unique visual behavior in that it is able to aim at and shoot down with a squirt of water insects resting on the foliage above water level and then feed on them. This extreme behavior requires excellent visual acuity, learning, and tight synchronization between the visual system and body motion. This behavior also raises many important questions, such as the fish's ability to compensate for air-water refraction and the neural mechanisms underlying target acquisition. While many such questions remain open, significant insights towards solving them can be obtained by tracking the eye and body movements of freely behaving fish. Unfortunately, existing tracking methods suffer from either a high level of invasiveness or low resolution. Here, we present a video-based eye tracking method for accurately and remotely measuring the eye and body movements of a freely moving behaving fish. Based on a stereo vision system and a unique triangulation method that corrects for air-glass-water refraction, we are able to measure a full three-dimensional pose of the fish eye and body with high temporal and spatial resolution. Our method, being generic, can be applied to studying the behavior of marine animals in general. We demonstrate how data collected by our method may be used to show that the hunting behavior of the archer fish is composed of surfacing concomitant with rotating the body around the direction of the fish's fixed gaze towards the target, until the snout reaches in the correct shooting position at water level.

Historical changes in Nebraska's lotic fish assemblages: Implications of anthropogenic alterations

USGS Publications Warehouse

Smith, Christopher D.; Fischer, Jesse R.; Quist, Michael C.

2014-01-01

The plains of midwestern North America have undergone significant anthropogenic alterations following European settlement with consequent effects to lotic fish assemblage structure. We examined trends in fish assemblage structure and function in Nebraska's lotic systems using site-specific, presence-absence data from historical (1939–1940) and contemporary surveys (2003–2005; n  =  183). Shifts in fish assemblage structure were characterized by declines of specialist species (e.g., western silvery minnow Hybognathus argyritis) and increases in nonnative, sport, and generalist species (e.g., common carp Cyprinus carpio). Our research illustrates differences between historical and contemporary surveys for both taxonomic and functional metrics. Changes in fish assemblage structure were correlated with a contemporary measure of anthropogenic alteration (Human Threat Index; HTI) and were most pronounced for large-scale threats (i.e., watershed HTI, overall HTI). The HTI is a composite index of cumulative anthropogenic alterations experienced by a stream system and was used to investigate broad-scale implications of anthropogenic activity on fish assemblage structure. Fish assemblages among sites were more similar in contemporary surveys than in historical surveys, such changes might indicate a homogenization of the fish assemblages. Losses of native species and increases in introduced species have occurred in Nebraska's lotic systems across a broad temporal span and shifts are likely related to high levels of human perturbation.

Selective Preservation of Fossil Ghost Fish

NASA Astrophysics Data System (ADS)

Meacham, Amanda

2016-04-01

A unique type of fossil fish preservation has been discovered in the Angelo Member (Fossil Lake) of the Green River Formation. The Angelo Member is a predominately evaporative deposit dominated by dolomite, but contains facies of fossiliferous laminated calcimicrite. Fossil fish occurring in two beds conspicuously lack bones. Fish in the lower bed are only preserved as organic material, including skin, pigments, and eyes. Fish in the upper bed have three-dimensional etching where bones once existed but also contain skin, pigments, and eyes. The top third of the upper bed often contains calcite crystals that are pseudomorphs after trona and possibly halite. Preliminary mineralogical analysis and mapping of evaporate facies suggests that this unique preservation may be related to lake geochemical conditions, such as high pH and alkalinity. To our knowledge, this is the first time this type of preservation has been observed and studied. Fossils and sediments within these beds are being studied both vertically and laterally through the one-meter thick sequence containing the fossil fish using XRD, isotopic, SEM, thin section, and total organic carbon analysis. Nine quarries, 0.5-1 meter square, were excavated for both fossils and rock samples along with 17 additional rock sample locations across an approximately 25-kilometer square region. This investigation has the capability of reconstructing the paleoenvironment and lake chemistry of Fossil Lake during the deposition of the "ghost-fish" beds and solving the mystery of the "missing bones" and the unusual process of preservation.

Symptoms and implications of selenium toxicity in fish: the Belews Lake case example

Treesearch

A. Dennis Lemly

2002-01-01

Belews Lake, North Carolina was contaminated by selenium in wastewater from a coal-fired power plant during the mid-1970s and toxic impacts to the resident fish community (20 species) were studied for over two decades. Symptoms of chronic selcnitun poisoning in Belews Lake fish included, (1) telangiectasia (swelling) of gill lamellae; (2) elevated lymphocytes; (3)...

Scombroid poisoning.

PubMed

Lange, W R

1988-04-01

The symptoms of scombroid poisoning resemble an acute allergic reaction. Tuna, albacore, mackerel and bonito are implicated, as are nonscombroid fish such as mahi-mahi and bluefish. The histamine content of affected fish is high, but the pathophysiology is more complex than the mere ingestion of histamine. Antihistamines and cimetidine appear to be effective in controlling symptoms. Prevention consists of prompt and adequate refrigeration of dark-meated fish.

Rapid Stable Isotope Turnover of Larval Fish in a Lake Superior Coastal Wetland: Implications for Diet and Life History Studies

EPA Science Inventory

Trophic linkages of larval fish in Lake Superior coastal wetlands, rivers and embayments can be identified using naturally occurring differences in the stable isotope ratios of nitrogen (15N:14N, ?15N) and carbon (13C:12C, ?13C). We sampled pelagic fish larvae weekly during sprin...

Niche partitioning of feeding microhabitats produces a unique function for herbivorous rabbitfishes (Perciformes, Siganidae) on coral reefs

NASA Astrophysics Data System (ADS)

Fox, R. J.; Bellwood, D. R.

2013-03-01

Niche theory predicts that coexisting species minimise competition by evolving morphological or behavioural specialisations that allow them to spread out along resource axes such as space, diet and temporal activity. These specialisations define how a species interacts with its environment and, by extension, determine its functional role. Here, we examine the feeding niche of three species of coral reef-dwelling rabbitfishes (Siganidae, Siganus). By comparing aspects of their feeding behaviour (bite location, bite rate, foraging distance) with that of representative species from two other abundant herbivorous fish families, the parrotfishes (Labridae, Scarus) and surgeonfishes (Acanthuridae, Acanthurus), we examine whether rabbitfishes have a feeding niche distinct from other members of the herbivore guild. Measurements of the penetration of the fishes' snouts and bodies into reef concavities when feeding revealed that rabbitfish fed to a greater degree from reef crevices and interstices than other herbivores. There was just a 40 % overlap in the penetration-depth niche between rabbitfish and surgeonfish and a 45 % overlap between rabbitfish and parrotfish, compared with the almost complete niche overlap (95 %) recorded for parrotfish and surgeonfish along this spatial niche axis. Aspects of the morphology of rabbitfish which may contribute to this niche segregation include a comparatively longer, narrower snout and narrower head. Our results suggest that sympatric coexistence of rabbitfish and other reef herbivores is facilitated by segregation along a spatial (and potentially dietary) axis. This segregation results in a unique functional role for rabbitfishes among roving herbivores that of "crevice-browser": a group that specifically feeds on crevice-dwelling algal or benthic organisms. This functional trait may have implications for reef ecosystem processes in terms of controlling the successional development of crevice-based algal communities, reducing their potential to trigger macroalgal outbreaks.

Musculoskeletal anatomy of the pelvic fin of Polypterus: implications for phylogenetic distribution and homology of pre- and postaxial pelvic appendicular muscles.

PubMed

Molnar, Julia L; Johnston, Peter S; Esteve-Altava, Borja; Diogo, Rui

2017-04-01

As a member of the most basal clade of extant ray-finned fishes (actinopterygians) and of one of the most basal clades of osteichthyans (bony fishes + tetrapods), Polypterus can provide insights into the ancestral anatomy of both ray-finned and lobe-finned fishes, including those that gave rise to tetrapods. The pectoral fin of Polypterus has been well described but, surprisingly, neither the bones nor the muscles of the pelvic fin are well known. We stained and dissected the pelvic fin of Polypterus senegalus and Polypterus delhezi to offer a detailed description of its musculoskeletal anatomy. In addition to the previously described adductor and abductor muscles, we found preaxial and postaxial muscles similar to those in the pectoral fin of members of this genus. The presence of pre- and postaxial muscles in both the pectoral and pelvic fins of Polypterus, combined with recent descriptions of similar muscles in the lobe-finned fishes Latimeria and Neoceratodus, suggests that they were present in the most recent common ancestor of bony fishes. These results have crucial implications for the evolution of appendicular muscles in both fish and tetrapods. © 2016 Anatomical Society.

Using posts to an online social network to assess fishing effort

USGS Publications Warehouse

Martin, Dustin R.; Chizinski, Christopher J.; Eskridge, Kent M.; Pope, Kevin L

2014-01-01

Fisheries management has evolved from reservoir to watershed management, creating a need to simultaneously gather information within and across interacting reservoirs. However, costs to gather information on the fishing effort on multiple reservoirs using traditional creel methodology are often prohibitive. Angler posts about reservoirs online provide a unique medium to test hypotheses on the distribution of fishing pressure. We show that the activity on an online fishing social network is related to fishing effort and can be used to facilitate management goals. We searched the Nebraska Fish and Game Association Fishing Forum for all references from April 2009 to December 2010 to 19 reservoirs that comprise the Salt Valley regional fishery in southeastern Nebraska. The number of posts was positively related to monthly fishing effort on a regional scale, with individual reservoirs having the most annual posts also having the most annual fishing effort. Furthermore, this relationship held temporally. Online fishing social networks provide the potential to assess effort on larger spatial scales than currently feasible.

Eoalosa janvieri gen. et sp. nov., a new clupeid fish (Teleostei, Clupeiformes) from the Eocene of Monte Bolca, Italy.

PubMed

Marramà, Giuseppe; Carnevale, Giorgio

2018-01-01

Fishes of the family Clupeidae are extremely abundant in the Eocene fossiliferous limestone of Monte Bolca representing the most common group from this celebrated locality. A new clupeid from the Pesciara site, Eoalosa janvieri gen. et sp. nov., is described. The new taxon exhibits a unique combination of characters supporting its recognition as a new genus and species of clupeid fish that is tentatively placed in the subfamily Alosinae. The description of this new taxon improves our knowledge of the diversity of clupeoid fishes in the Eocene of Monte Bolca.

Addressing species diversity in biotransformation: Variability in expressed transcripts of Phase I and II hepatic enzymes among fishes

EPA Science Inventory

The ability of an organism to metabolize a pollutant is critical to understanding the risk the chemical poses to the organism. In the environment, fish are uniquely exposed to pollutants found in agricultural runoff and discharges from industry and wastewater treatment plants. M...

Hagfish predatory behaviour and slime defence mechanism

PubMed Central

Zintzen, Vincent; Roberts, Clive D.; Anderson, Marti J.; Stewart, Andrew L.; Struthers, Carl D.; Harvey, Euan S.

2011-01-01

Hagfishes (Myxinidae), a family of jawless marine pre-vertebrates, hold a unique evolutionary position, sharing a joint ancestor with the entire vertebrate lineage. They are thought to fulfil primarily the ecological niche of scavengers in the deep ocean. However, we present new footage from baited video cameras that captured images of hagfishes actively preying on other fish. Video images also revealed that hagfishes are able to choke their would-be predators with gill-clogging slime. This is the first time that predatory behaviour has been witnessed in this family, and also demonstrates the instantaneous effectiveness of hagfish slime to deter fish predators. These observations suggest that the functional adaptations and ecological role of hagfishes, past and present, might be far more diverse than previously assumed. We propose that the enduring success of this oldest extant family of fishes over 300 million years could largely be due to their unique combination of functional traits. PMID:22355648

Occupational asthma in the commercial fishing industry: a case series and review of the literature.

PubMed

Lucas, David; Lucas, Raymond; Boniface, Keith; Jegaden, Dominique; Lodde, Brice; Dewitte, Jean-Ariel

2010-01-01

We present a case series of snow crab-induced occupational asthma (OA) from a fishing and processing vessel, followed by a review of OA in the commercial fishing industry. OA is typically caused from an IgE-mediated hypersensitivity reaction after respiratory exposure to aerosolized fish and shellfish proteins. It more commonly occurs due to crustaceans, but molluscs and fin fish are implicated as well. Standard medical therapy for asthma may be used acutely; however, steps to reduce atmospheric allergen concentrations in the workplace have proven to be preventive for this disease.

A symmoriiform chondrichthyan braincase and the origin of chimaeroid fishes.

PubMed

Coates, Michael I; Gess, Robert W; Finarelli, John A; Criswell, Katharine E; Tietjen, Kristen

2017-01-12

Chimaeroid fishes (Holocephali) are one of the four principal divisions of modern gnathostomes (jawed vertebrates). Despite only 47 described living species, chimaeroids are the focus of resurgent interest as potential archives of genomic data and for the unique perspective they provide on chondrichthyan and gnathostome ancestral conditions. Chimaeroids are also noteworthy for their highly derived body plan. However, like other living groups with distinctive anatomies, fossils have been of limited use in unravelling their evolutionary origin, as the earliest recognized examples already exhibit many of the specializations present in modern forms. Here we report the results of a computed tomography analysis of Dwykaselachus, an enigmatic chondrichthyan braincase from the ~280 million year old Karoo sediments of South Africa. Externally, the braincase is that of a symmoriid shark and is by far the most complete uncrushed example yet discovered. Internally, the morphology exhibits otherwise characteristically chimaeroid specializations, including the otic labyrinth arrangement and the brain space configuration relative to exceptionally large orbits. These results have important implications for our view of modern chondrichthyan origins, add robust structure to the phylogeny of early crown group gnathostomes, reveal preconditions that suggest an initial morpho-functional basis for the derived chimaeroid cranium, and shed new light on the chondrichthyan response to the extinction at the end of the Devonian period.

Design and testing of a mesocosm-scale habitat for culturing the endangered Devils Hole Pupfish

USGS Publications Warehouse

Feuerbacher, Olin; Bonar, Scott A.; Barrett, Paul J.

2016-01-01

aptive propagation of desert spring fishes, whether for conservation or research, is often difficult, given the unique and often challenging environments these fish utilize in nature. High temperatures, low dissolved oxygen, minimal water flow, and highly variable lighting are some conditions a researcher might need to recreate to simulate their natural environments. Here we describe a mesocosm-scale habitat created to maintain hybrid Devils Hole × Ash Meadows Amargosa Pupfish (Cyprinodon diabolis × C. nevadensis mionectes) under conditions similar to those found in Devils Hole, Nevada. This 13,000-L system utilized flow control and natural processes to maintain these conditions rather than utilizing complex and expensive automation. We designed a rotating solar collector to control natural sunlight, a biological reactor to consume oxygen while buffering water quality, and a reverse-daylight photosynthesis sump system to stabilize nighttime pH and swings in dissolved oxygen levels. This system successfully controlled many desired parameters and helped inform development of a larger, more permanent desert fish conservation facility at the U.S. Fish and Wildlife Service’s Ash Meadows National Wildlife Refuge, Nevada. For others who need to raise fish from unique habitats, many components of the scalable and modular design of this system can be adapted at reasonable cost.

Hematology, cytochemistry and ultrastructure of blood cells in fishing cat (Felis viverrina).

PubMed

Prihirunkit, Kreangsak; Salakij, Chaleow; Apibal, Suntaree; Narkkong, Nual Anong

2007-06-01

Hematological, cytochemical and ultrastructural features of blood cells in fishing cat (Felis viverrina) were evaluated using complete blood cell counts with routine and cytochemical blood stains, and scanning and transmission electron microscopy. No statistically significant difference was found in different genders of this animal. Unique features of blood cells in this animal were identified in hematological, cytochemical and ultrastructural studies. This study contributes to broaden hematological resources in wildlife animals and provides a guideline for identification of blood cells in the fishing cat.

Impact of treated wastewater reuse and floods on water quality and fish health within a water reservoir in an arid climate.

PubMed

Zaibel, Inbal; Zilberg, Dina; Groisman, Ludmila; Arnon, Shai

2016-07-15

Treated wastewater (TWW) reuse for agricultural irrigation is a well-established approach to coping with water shortages in semi-arid and arid environments. Recently, additional uses of TWW have emerged, including streamflow augmentation and aquatic ecosystem restoration. The purpose of the current study was to evaluate the water quality and fish health, in an artificial reservoir located in an arid climate (the Yeruham Reservoir, Israel), which regularly receives TWW and sporadic winter floods. The temporal distribution of water levels, nutrients and organic micropollutants (OMPs) were measured during the years 2013-2014. OMPs were also measured in sediment and fish tissues. Finally, the status of fish health was evaluated by histopathology. Water levels and quality were mainly influenced by seasonal processes such as floods and evaporation, and not by the discharge of TWW. Out of 16 tested OMPs, estrone, carbamazepine, diclofenac and bezafibrate were found in the reservoir water, but mostly at concentrations below the predicted no-effect concentration (PNEC) for fish. Concentrations of PCBs and dioxins in fish muscle and liver were much lower than the EU maximal permitted concentrations, and similar to concentrations that were found in food fish in Israel and Europe. In the histopathological analysis, there were no evident tissue abnormalities, and low to moderate infection levels of fish parasites were recorded. The results from the Yeruham Reservoir demonstrated a unique model for the mixture effect between TWW reuse and natural floods to support a unique stable and thriving ecosystem in a water reservoir located in an arid region. This type of reservoir can be widely used for recreation, education, and the social and economic development of a rural environment, such as has occurred in the Yeruham region. Copyright © 2016 Elsevier B.V. All rights reserved.

Fish as major carbonate mud producers and missing components of the tropical carbonate factory

PubMed Central

Perry, Chris T.; Salter, Michael A.; Harborne, Alastair R.; Crowley, Stephen F.; Jelks, Howard L.; Wilson, Rod W.

2011-01-01

Carbonate mud is a major constituent of recent marine carbonate sediments and of ancient limestones, which contain unique records of changes in ocean chemistry and climate shifts in the geological past. However, the origin of carbonate mud is controversial and often problematic to resolve. Here we show that tropical marine fish produce and excrete various forms of precipitated (nonskeletal) calcium carbonate from their guts (“low” and “high” Mg-calcite and aragonite), but that very fine-grained (mostly < 2 μm) high Mg-calcite crystallites (i.e., MgCO3) are their dominant excretory product. Crystallites from fish are morphologically diverse and species-specific, but all are unique relative to previously known biogenic and abiotic sources of carbonate within open marine systems. Using site specific fish biomass and carbonate excretion rate data we estimate that fish produce ∼6.1 × 106 kg CaCO3/year across the Bahamian archipelago, all as mud-grade (the < 63 μm fraction) carbonate and thus as a potential sediment constituent. Estimated contributions from fish to total carbonate mud production average ∼14% overall, and exceed 70% in specific habitats. Critically, we also document the widespread presence of these distinctive fish-derived carbonates in the finest sediment fractions from all habitat types in the Bahamas, demonstrating that these carbonates have direct relevance to contemporary carbonate sediment budgets. Fish thus represent a hitherto unrecognized but significant source of fine-grained carbonate sediment, the discovery of which has direct application to the conceptual ideas of how marine carbonate factories function both today and in the past. PMID:21368155

Effects of Changes in Food Supply at the Time of Sex Differentiation on the Gonadal Transcriptome of Juvenile Fish. Implications for Natural and Farmed Populations

PubMed Central

Díaz, Noelia; Ribas, Laia; Piferrer, Francesc

2014-01-01

Background Food supply is a major factor influencing growth rates in animals. This has important implications for both natural and farmed fish populations, since food restriction may difficult reproduction. However, a study on the effects of food supply on the development of juvenile gonads has never been transcriptionally described in fish. Methods and Findings This study investigated the consequences of growth on gonadal transcriptome of European sea bass in: 1) 4-month-old sexually undifferentiated fish, comparing the gonads of fish with the highest vs. the lowest growth, to explore a possible link between transcriptome and future sex, and 2) testis from 11-month-old juveniles where growth had been manipulated through changes in food supply. The four groups used were: i) sustained fast growth, ii) sustained slow growth, iii) accelerated growth, iv) decelerated growth. The transcriptome of undifferentiated gonads was not drastically affected by initial natural differences in growth. Further, changes in the expression of genes associated with protein turnover were seen, favoring catabolism in slow-growing fish and anabolism in fast-growing fish. Moreover, while fast-growing fish took energy from glucose, as deduced from the pathways affected and the analysis of protein-protein interactions examined, in slow-growing fish lipid metabolism and gluconeogenesis was favored. Interestingly, the highest transcriptomic differences were found when forcing initially fast-growing fish to decelerate their growth, while accelerating growth of initially slow-growing fish resulted in full transcriptomic convergence with sustained fast-growing fish. Conclusions Food availability during sex differentiation shapes the juvenile testis transcriptome, as evidenced by adaptations to different energy balances. Remarkably, this occurs in absence of major histological changes in the testis. Thus, fish are able to recover transcriptionally their testes if they are provided with enough food supply during sex differentiation; however, an initial fast growth does not represent any advantage in terms of transcriptional fitness if later food becomes scarce. PMID:25340342

Effects of changes in food supply at the time of sex differentiation on the gonadal transcriptome of juvenile fish. Implications for natural and farmed populations.

PubMed

Díaz, Noelia; Ribas, Laia; Piferrer, Francesc

2014-01-01

Food supply is a major factor influencing growth rates in animals. This has important implications for both natural and farmed fish populations, since food restriction may difficult reproduction. However, a study on the effects of food supply on the development of juvenile gonads has never been transcriptionally described in fish. This study investigated the consequences of growth on gonadal transcriptome of European sea bass in: 1) 4-month-old sexually undifferentiated fish, comparing the gonads of fish with the highest vs. the lowest growth, to explore a possible link between transcriptome and future sex, and 2) testis from 11-month-old juveniles where growth had been manipulated through changes in food supply. The four groups used were: i) sustained fast growth, ii) sustained slow growth, iii) accelerated growth, iv) decelerated growth. The transcriptome of undifferentiated gonads was not drastically affected by initial natural differences in growth. Further, changes in the expression of genes associated with protein turnover were seen, favoring catabolism in slow-growing fish and anabolism in fast-growing fish. Moreover, while fast-growing fish took energy from glucose, as deduced from the pathways affected and the analysis of protein-protein interactions examined, in slow-growing fish lipid metabolism and gluconeogenesis was favored. Interestingly, the highest transcriptomic differences were found when forcing initially fast-growing fish to decelerate their growth, while accelerating growth of initially slow-growing fish resulted in full transcriptomic convergence with sustained fast-growing fish. Food availability during sex differentiation shapes the juvenile testis transcriptome, as evidenced by adaptations to different energy balances. Remarkably, this occurs in absence of major histological changes in the testis. Thus, fish are able to recover transcriptionally their testes if they are provided with enough food supply during sex differentiation; however, an initial fast growth does not represent any advantage in terms of transcriptional fitness if later food becomes scarce.

Fish assemblages at engineered and natural channel structures in the lower Missouri river: implications for modified dike structures

USGS Publications Warehouse

Schloesser, J.T.; Paukert, Craig P.; Doyle, W.J.; Hill, T.; Steffensen, K.D.; Travnichek, Vincent H.

2012-01-01

Large rivers throughout the world have been modified by using dike structures to divert water flows to deepwater habitats to maintain navigation channels. These modifications have been implicated in the decline in habitat diversity and native fishes. However, dike structures have been modified in the Missouri River USA to increase habitat diversity to aid in the recovery of native fishes. We compared species occupancy and fish community composition at natural sandbars and at notched and un-notched rock dikes along the lower Missouri River to determine if notching dikes increases species diversity or occupancy of native fishes. Fish were collected using gill nets, trammel nets, otter trawls, and mini fyke nets throughout the lower 1212 river km of the Missouri River USA from 2003 to 2006. Few differences in species richness and diversity were evident among engineered dike structures and natural sandbars. Notching a dike structure had no effect on proportional abundance of fluvial dependents, fluvial specialists, and macrohabitat generalists. Occupancy at notched dikes increased for two species but did not differ for 17 other species (81%). Our results suggest that dike structures may provide suitable habitats for fluvial species compared with channel sand bars, but dike notching did not increase abundance or occupancy of most Missouri River fishes. Published in 2011 by John Wiley & Sons, Ltd.

Fish Ontology framework for taxonomy-based fish recognition

PubMed Central

Ali, Najib M.; Khan, Haris A.; Then, Amy Y-Hui; Ving Ching, Chong; Gaur, Manas

2017-01-01

Life science ontologies play an important role in Semantic Web. Given the diversity in fish species and the associated wealth of information, it is imperative to develop an ontology capable of linking and integrating this information in an automated fashion. As such, we introduce the Fish Ontology (FO), an automated classification architecture of existing fish taxa which provides taxonomic information on unknown fish based on metadata restrictions. It is designed to support knowledge discovery, provide semantic annotation of fish and fisheries resources, data integration, and information retrieval. Automated classification for unknown specimens is a unique feature that currently does not appear to exist in other known ontologies. Examples of automated classification for major groups of fish are demonstrated, showing the inferred information by introducing several restrictions at the species or specimen level. The current version of FO has 1,830 classes, includes widely used fisheries terminology, and models major aspects of fish taxonomy, grouping, and character. With more than 30,000 known fish species globally, the FO will be an indispensable tool for fish scientists and other interested users. PMID:28929028

Contrasting Fish Behavior in Artificial Seascapes with Implications for Resources Conservation

PubMed Central

Koeck, Barbara; Alós, Josep; Caro, Anthony; Neveu, Reda; Crec'hriou, Romain; Saragoni, Gilles; Lenfant, Philippe

2013-01-01

Artificial reefs are used by many fisheries managers as a tool to mitigate the impact of fisheries on coastal fish communities by providing new habitat for many exploited fish species. However, the comparison between the behavior of wild fish inhabiting either natural or artificial habitats has received less attention. Thus the spatio-temporal patterns of fish that establish their home range in one habitat or the other and their consequences of intra-population differentiation on life-history remain largely unexplored. We hypothesize that individuals with a preferred habitat (i.e. natural vs. artificial) can behave differently in terms of habitat use, with important consequences on population dynamics (e.g. life-history, mortality, and reproductive success). Therefore, using biotelemetry, 98 white seabream (Diplodus sargus) inhabiting either artificial or natural habitats were tagged and their behavior was monitored for up to eight months. Most white seabreams were highly resident either on natural or artificial reefs, with a preference for the shallow artificial reef subsets. Connectivity between artificial and natural reefs was limited for resident individuals due to great inter-habitat distances. The temporal behavioral patterns of white seabreams differed between artificial and natural reefs. Artificial-reef resident fish had a predominantly nocturnal diel pattern, whereas natural-reef resident fish showed a diurnal diel pattern. Differences in diel behavioral patterns of white seabream inhabiting artificial and natural reefs could be the expression of realized individual specialization resulting from differences in habitat configuration and resource availability between these two habitats. Artificial reefs have the potential to modify not only seascape connectivity but also the individual behavioral patterns of fishes. Future management plans of coastal areas and fisheries resources, including artificial reef implementation, should therefore consider the potential effect of habitat modification on fish behavior, which could have key implications on fish dynamics. PMID:23935978

Contrasting fish behavior in artificial seascapes with implications for resources conservation.

PubMed

Koeck, Barbara; Alós, Josep; Caro, Anthony; Neveu, Reda; Crec'hriou, Romain; Saragoni, Gilles; Lenfant, Philippe

2013-01-01

Artificial reefs are used by many fisheries managers as a tool to mitigate the impact of fisheries on coastal fish communities by providing new habitat for many exploited fish species. However, the comparison between the behavior of wild fish inhabiting either natural or artificial habitats has received less attention. Thus the spatio-temporal patterns of fish that establish their home range in one habitat or the other and their consequences of intra-population differentiation on life-history remain largely unexplored. We hypothesize that individuals with a preferred habitat (i.e. natural vs. artificial) can behave differently in terms of habitat use, with important consequences on population dynamics (e.g. life-history, mortality, and reproductive success). Therefore, using biotelemetry, 98 white seabream (Diplodus sargus) inhabiting either artificial or natural habitats were tagged and their behavior was monitored for up to eight months. Most white seabreams were highly resident either on natural or artificial reefs, with a preference for the shallow artificial reef subsets. Connectivity between artificial and natural reefs was limited for resident individuals due to great inter-habitat distances. The temporal behavioral patterns of white seabreams differed between artificial and natural reefs. Artificial-reef resident fish had a predominantly nocturnal diel pattern, whereas natural-reef resident fish showed a diurnal diel pattern. Differences in diel behavioral patterns of white seabream inhabiting artificial and natural reefs could be the expression of realized individual specialization resulting from differences in habitat configuration and resource availability between these two habitats. Artificial reefs have the potential to modify not only seascape connectivity but also the individual behavioral patterns of fishes. Future management plans of coastal areas and fisheries resources, including artificial reef implementation, should therefore consider the potential effect of habitat modification on fish behavior, which could have key implications on fish dynamics.

Projected entrainment of fish resulting from aggregate dredging.

PubMed

Drabble, Ray

2012-02-01

Previous research to assess impacts from aggregate dredging has focussed on infaunal species with few studies made of fish entrainment. Entrainment evidence from hydraulic dredging studies is reviewed to develop a sensitivity index for benthic fish. Environmental monitoring attendant with the granting of new licences in the Eastern Channel Region (ECR) in 2006 offers a unique opportunity to assess the effects of dredging upon fish. Projected theoretical fish entrainment rates are calculated based upon: abundance data from 4m beam trawl sampling of fish species over the period 2005-2008; sensitivity data; and dredging activity and footprint derived from Electronic monitoring System (EMS) data. Results have been compared with actual entrainment rates and also against summary results from independent analysis of the changes in fish population over the period 2005-2008 (Drabble, 2012). The case is made for entrainment surveys to form part of impact monitoring for marine aggregate dredging. Copyright © 2011 Elsevier Ltd. All rights reserved.

The effect of creosote on vitellogenin production in rainbow trout (Oncorhynchus mykiss)

USGS Publications Warehouse

Sherry, J.P.; Whyte, J.J.; Karrow, N.A.; Gamble, A.; Boerman, H.J.; Bol, N.C.; Dixon, D.G.; Solomon, K.R.

2006-01-01

As part of a broader investigation into the effects of creosote treatments on the aquatic biota in pond microcosms, we examined the possible implications for vitellogenin (Vtg) production in Oncorhynchus mykiss [rainbow trout (RT)]. Vtg is the precursor of egg yolk protein and has emerged as a useful biomarker of exposure to estrogenic substances. Our a priori intent was to assess the ability of the creosote treatments (nominal cresoste concentrations were 0, 3, and 10 ??l/L immediately after the last subsurface addition) to induce estrogenic responses in RT. The data showed no evidence of an estrogenic response in the treated fish. During the course of the experiment, however, the fish matured and began to produce Vtg, probably in response to endogenous estrogen. A posteriori analysis of the Vtg data from the maturing fish showed that after 28 days, the plasma Vtg concentrations were about 15-fold lower in fish from the creosote-treated microcosms compared with fish from the reference microcosm. Although the experiment design does not permit mechanistic insights, our observation suggests that exposure of female fish to PAH mixtures such as creosote can impair the production of Vtg with possible health implications for embryos and larvae. ?? 2006 Springer Science+Business Media, Inc.

[Study of three ciguatera fish poisoning cases in Xiamen city, in 2005].

PubMed

Luo, He-dong; Bai, Yan-yan; Zhou, Na

2011-06-01

To find out the reason of three ciguatera fish poisoning cases in Xiamen in 2005 and identify the fish species. The grouper implicated in food poisoning and seven other coral reef fishes collected from market were tested by mice bioassay and ciguatoxin-test kit. The mtDNA was extracted from toxic grouper meat, and Cty b gene segment was amplified and the PCR products were sequenced. The sequences were compared with those in the GenBank. The result turned out to be positive by the ciguatoxin-test kit, while the toxicity of the toxic grouper implicated in food poisoning was 0.11 mouse unit (MU)/g by mice bioassay. A 475 bp segments of Cty b gene was amplified by PCR and the sequence was 99% homologous with Epinephelus fuscoguttatus (GenBank: AY950695).No ciguatoxin in six grouper species collected from market was detected. All three food poisoning cases were caused by consumption of ciguatoxin-carrying groupers.

Antimicrobial Peptides from Fish

PubMed Central

Masso-Silva, Jorge A.; Diamond, Gill

2014-01-01

Antimicrobial peptides (AMPs) are found widely distributed through Nature, and participate in the innate host defense of each species. Fish are a great source of these peptides, as they express all of the major classes of AMPs, including defensins, cathelicidins, hepcidins, histone-derived peptides, and a fish-specific class of the cecropin family, called piscidins. As with other species, the fish peptides exhibit broad-spectrum antimicrobial activity, killing both fish and human pathogens. They are also immunomodulatory, and their genes are highly responsive to microbes and innate immuno-stimulatory molecules. Recent research has demonstrated that some of the unique properties of fish peptides, including their ability to act even in very high salt concentrations, make them good potential targets for development as therapeutic antimicrobials. Further, the stimulation of their gene expression by exogenous factors could be useful in preventing pathogenic microbes in aquaculture. PMID:24594555

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

PubMed

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

2011-03-09

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

Water levels shape fishing participation in flood-control reservoirs

USGS Publications Warehouse

Miranda, Leandro E.; Meals, K. O.

2013-01-01

We examined the relationship between fishing effort (hours fished) and average March–May water level in 3 flood control reservoirs in Mississippi. Fishing effort increased as water level rose, peaked at intermediate water levels, and decreased at high water levels. We suggest that the observed arched-shaped relationship is driven by the shifting influence of fishability (adequacy of the fishing circumstances from an angler's perspective) and catch rate along a water level continuum. Fishability reduces fishing effort during low water, despite the potential for higher catch rates. Conversely, reduced catch rates and fishability at high water also curtail effort. Thus, both high and low water levels seem to discourage fishing effort, whereas anglers seem to favor intermediate water levels. Our results have implications for water level management in reservoirs with large water level fluctuations.

Patterns in Habitat and Fish Assemblages within Great Lakes Coastal Wetlands and Implications for Sampling Design

EPA Science Inventory

Discerning fish - habitat associations at a variety of spatial scales is relevant to evaluating stressor responses and assessment protocols in Great Lakes coastal wetlands. NMDS ordination of electrofishing catch-per-effort data identified an overriding influence of geography an...

Vertical stratification in the distribution of demersal fishes along the walls of the La Jolla and Scripps submarine canyons, California, USA

NASA Astrophysics Data System (ADS)

Smith, Joshua G.; Lindholm, James

2016-08-01

The geographic distributions of many coastal marine fish assemblages are strongly driven by habitat features, particularly among demersal fishes that live along the seafloor. Ecologists have long recognized the importance of characterizing fish habitat associations, especially where spatial management is under consideration. However, little is known about fish distributions and habitat suitability in unique demersal habitats such as submarine canyons. The active continental margin of the California coast is cut by eight submarine canyons, several of which extend from the shore to the deep abyssal plain. We sampled the demersal fish assemblages in two of those canyons: (1) the Scripps submarine canyon in the San-Diego-Scripps State Marine Conservation Area (SMCA) and (2) the La Jolla canyon in the Matlahuayl State Marine Reserve (SMR) to gain insight into both the distributions and habitat associations of demersal fishes in canyons. A remotely operated vehicle was used to conduct 21 vertically oriented transects along the canyon walls in depths ranging from 20 to 300 m. Species composition was assessed in three depth-stratified zones (100 m per zone) along the canyon walls. Species richness, abundance, and attributes of the surrounding canyon habitat structure (slope and benthic terrain ruggedness) were quantified. Three distinct assemblage groupings were identified, which comprised 35 species of demersal fishes from 17 families. Among all factors analyzed in this study, depth, slope, and ruggedness were strong explanatory variables of patterns of species richness and abundance; however, the relationship between depth and assemblage structure was non-linear. The greatest number of species was observed in the mid depth-stratified zone. These trends suggest that variation in canyon dynamics across depth strata may facilitate distinct assemblage groupings of demersal fishes, which can in turn be used to better manage these unique habitats.

Estimating Recreational Use of a Unique Trout Stream in the Coastal Plains of South Carolina

Treesearch

George A. James; Nelson W. Taylor; Melvin L. Hopkins

1971-01-01

A sampling technique for estimating fishing use was pilot tested on a small trout stream on the Santee Ranger District, Francis Marion National Forest in South Carolina during fall and winter 1969-70. A short questionnaire, completed by fishermen using the stream, provided information relating to the variables of interest. Reliable estimates of fishing use were...

Clostridium botulinum in Scottish fish farms and farmed trout.

PubMed

Burns, G F; Williams, H

1975-02-01

Rainbow trout and specimens of pond mud were collected from three fish farms and examined for the presence of Clostridium botulinum. Two of the farms were constructed with concrete channels and one was mud-bottomed. Cl. botulinum was isolated only from the mud-bottomed farm (24% of muds), and the isolates were all non-proteolytic type B. The implications of the presence of Cl. botulinum spores in the mud of fish farms is discussed.

Consistent nutrient storage and supply mediated by diverse fish communities in coral reef ecosystems.

PubMed

Allgeier, Jacob E; Layman, Craig A; Mumby, Peter J; Rosemond, Amy D

2014-08-01

Corals thrive in low nutrient environments and the conservation of these globally imperiled ecosystems is largely dependent on mitigating the effects of anthropogenic nutrient enrichment. However, to better understand the implications of anthropogenic nutrients requires a heightened understanding of baseline nutrient dynamics within these ecosystems. Here, we provide a novel perspective on coral reef nutrient dynamics by examining the role of fish communities in the supply and storage of nitrogen (N) and phosphorus (P). We quantified fish-mediated nutrient storage and supply for 144 species and modeled these data onto 172 fish communities (71 729 individual fish), in four types of coral reefs, as well as seagrass and mangrove ecosystems, throughout the Northern Antilles. Fish communities supplied and stored large quantities of nutrients, with rates varying among ecosystem types. The size structure and diversity of the fish communities best predicted N and P supply and storage and N : P supply, suggesting that alterations to fish communities (e.g., overfishing) will have important implications for nutrient dynamics in these systems. The stoichiometric ratio (N : P) for storage in fish mass (~8 : 1) and supply (~20 : 1) was notably consistent across the four coral reef types (but not seagrass or mangrove ecosystems). Published nutrient enrichment studies on corals show that deviations from this N : P supply ratio may be associated with poor coral fitness, providing qualitative support for the hypothesis that corals and their symbionts may be adapted to specific ratios of nutrient supply. Consumer nutrient stoichiometry provides a baseline from which to better understand nutrient dynamics in coral reef and other coastal ecosystems, information that is greatly needed if we are to implement more effective measures to ensure the future health of the world's oceans. © 2014 John Wiley & Sons Ltd.

Hematology, cytochemistry and ultrastructure of blood cells in fishing cat (Felis viverrina)

PubMed Central

Salakij, Chaleow; Apibal, Suntaree; Narkkong, Nual-Anong

2007-01-01

Hematological, cytochemical and ultrastructural features of blood cells in fishing cat (Felis viverrina) were evaluated using complete blood cell counts with routine and cytochemical blood stains, and scanning and transmission electron microscopy. No statistically significant difference was found in different genders of this animal. Unique features of blood cells in this animal were identified in hematological, cytochemical and ultrastructural studies. This study contributes to broaden hematological resources in wildlife animals and provides a guideline for identification of blood cells in the fishing cat. PMID:17519570

Accounting for escape mortality in fisheries: implications for stock productivity and optimal management.

PubMed

Baker, Matthew R; Schindler, Daniel E; Essington, Timothy E; Hilborn, Ray

2014-01-01

Few studies have considered the management implications of mortality to target fish stocks caused by non-retention in commercial harvest gear (escape mortality). We demonstrate the magnitude of this previously unquantified source of mortality and its implications for the population dynamics of exploited stocks, biological metrics, stock productivity, and optimal management. Non-retention in commercial gillnet fisheries for Pacific salmon (Oncorhynchus spp.) is common and often leads to delayed mortality in spawning populations. This represents losses, not only to fishery harvest, but also in future recruitment to exploited stocks. We estimated incidence of non-retention in Alaskan gillnet fisheries for sockeye salmon (O. nerka) and found disentanglement injuries to be extensive and highly variable between years. Injuries related to non-retention were noted in all spawning populations, and incidence of injury ranged from 6% to 44% of escaped salmon across nine river systems over five years. We also demonstrate that non-retention rates strongly correlate with fishing effort. We applied maximum likelihood and Bayesian approaches to stock-recruitment analyses, discounting estimates of spawning salmon to account for fishery-related mortality in escaped fish. Discounting spawning stock estimates as a function of annual fishing effort improved model fits to historical stock-recruitment data in most modeled systems. This suggests the productivity of exploited stocks has been systematically underestimated. It also suggests that indices of fishing effort may be used to predict escape mortality and correct for losses. Our results illustrate how explicitly accounting for collateral effects of fishery extraction may improve estimates of productivity and better inform management metrics derived from estimates of stock-recruitment analyses.

FISH-MEDIATED NUTRIENT AND ENERGY EXCHANGE BETWEEN A LAKE SUPERIOR COASTAL WETLAND AND ITS ADJACENT BAY

EPA Science Inventory

Little has been done to quantify fluxes of organisms, nutrients, and energy between freshwater coastal habitats and adjacent offshore waters or to evaluate the ecological implications of these exchanges on a whole-lake basis. To test the hypothesis that fish-mediated transport m...

A comparison of shoreline seines with fyke nets for sampling littoral fish communities in floodplain lakes

USGS Publications Warehouse

Clark, S.J.; Jackson, J.R.; Lochmann, S.E.

2007-01-01

We compared shoreline seines with fyke nets in terms of their ability to sample fish species in the littoral zone of 22 floodplain lakes of the White River, Arkansas. Lakes ranged in size from less than 0.5 to 51.0 ha. Most contained large amounts of coarse woody debris within the littoral zone, thus making seining in shallow areas difficult. We sampled large lakes (>2 ha) using three fyke nets; small lakes (<2 ha) were sampled using two fyke nets. Fyke nets were set for 24 h. Large lakes were sampled with an average of 11 seine hauls/ lake and small lakes were sampled with an average of 3 seine hauls/lake, but exact shoreline seining effort varied among lakes depending on the amount of open shoreline. Fyke nets collected more fish and produced greater species richness and diversity measures than did seining. Species evenness was similar for the two gear types. Two species were unique to seine samples, whereas 13 species and 3 families were unique to fyke-net samples. Although fyke nets collected more fish and more species than did shoreline seines, neither gear collected all the species present in the littoral zone of floodplain lakes. These results confirm the need for a multiple-gear approach to fully characterize the littoral fish assemblages in floodplain lakes. ?? Copyright by the American Fisheries Society 2007.

Bentho-pelagic divergence of cichlid feeding architecture was prodigious and consistent during multiple adaptive radiations within African rift-lakes.

PubMed

Cooper, W James; Parsons, Kevin; McIntyre, Alyssa; Kern, Brittany; McGee-Moore, Alana; Albertson, R Craig

2010-03-08

How particular changes in functional morphology can repeatedly promote ecological diversification is an active area of evolutionary investigation. The African rift-lake cichlids offer a calibrated time series of the most dramatic adaptive radiations of vertebrate trophic morphology yet described, and the replicate nature of these events provides a unique opportunity to test whether common changes in functional morphology have repeatedly facilitated their ecological success. Specimens from 87 genera of cichlid fishes endemic to Lakes Tanganyka, Malawi and Victoria were dissected in order to examine the functional morphology of cichlid feeding. We quantified shape using geometric morphometrics and compared patterns of morphological diversity using a series of analytical tests. The primary axes of divergence were conserved among all three radiations, and the most prevalent changes involved the size of the preorbital region of the skull. Even the fishes from the youngest of these lakes (Victoria), which exhibit the lowest amount of skull shape disparity, have undergone extensive preorbital evolution relative to other craniofacial traits. Such changes have large effects on feeding biomechanics, and can promote expansion into a wide array of niches along a bentho-pelagic ecomorphological axis. Here we show that specific changes in trophic anatomy have evolved repeatedly in the African rift lakes, and our results suggest that simple morphological alterations that have large ecological consequences are likely to constitute critical components of adaptive radiations in functional morphology. Such shifts may precede more complex shape changes as lineages diversify into unoccupied niches. The data presented here, combined with observations of other fish lineages, suggest that the preorbital region represents an evolutionary module that can respond quickly to natural selection when fishes colonize new lakes. Characterizing the changes in cichlid trophic morphology that have contributed to their extraordinary adaptive radiations has broad evolutionary implications, and such studies are necessary for directing future investigations into the proximate mechanisms that have shaped these spectacular phenomena.

The past and future of fish consumption: Can supplies meet healthy eating recommendations?

PubMed

Thurstan, Ruth H; Roberts, Callum M

2014-12-15

In many developed countries fish and shellfish are increasingly promoted as healthy alternatives to other animal protein. We analysed how much fish was available to UK and global populations after accounting for processing losses, and compared this to recommended levels of fish consumption. In 2012, UK domestic fish landings per capita fell 81% below the recommended intake, although declines were masked by increased imports and aquaculture from the 1970s onwards. Global wild fish supply per capita declined by 32% from its peak in 1970. However, overall fish supplies per capita increased by 10% over the same period due to rapidly expanding aquaculture production. Whilst aquaculture has so far prevented a downturn in global fish supplies, many developed nations continue to aspire to consume more fish than they produce. Until demand is balanced with sustainable methods of production governments should consider carefully the social and environmental implications of greater fish consumption. Copyright © 2014 Elsevier Ltd. All rights reserved.

Coral decline threatens fish biodiversity in marine reserves.

PubMed

Jones, Geoffrey P; McCormick, Mark I; Srinivasan, Maya; Eagle, Janelle V

2004-05-25

The worldwide decline in coral cover has serious implications for the health of coral reefs. But what is the future of reef fish assemblages? Marine reserves can protect fish from exploitation, but do they protect fish biodiversity in degrading environments? The answer appears to be no, as indicated by our 8-year study in Papua New Guinea. A devastating decline in coral cover caused a parallel decline in fish biodiversity, both in marine reserves and in areas open to fishing. Over 75% of reef fish species declined in abundance, and 50% declined to less than half of their original numbers. The greater the dependence species have on living coral as juvenile recruitment sites, the greater the observed decline in abundance. Several rare coral-specialists became locally extinct. We suggest that fish biodiversity is threatened wherever permanent reef degradation occurs and warn that marine reserves will not always be sufficient to ensure their survival.

Materials design principles of ancient fish armour

NASA Astrophysics Data System (ADS)

Bruet, Benjamin J. F.; Song, Juha; Boyce, Mary C.; Ortiz, Christine

2008-09-01

Knowledge of the structure-property-function relationships of dermal scales of armoured fish could enable pathways to improved bioinspired human body armour, and may provide clues to the evolutionary origins of mineralized tissues. Here, we present a multiscale experimental and computational approach that reveals the materials design principles present within individual ganoid scales from the `living fossil' Polypterus senegalus. This fish belongs to the ancient family Polypteridae, which first appeared 96 million years ago during the Cretaceous period and still retains many of their characteristics. The mechanistic origins of penetration resistance (approximating a biting attack) were investigated and found to include the juxtaposition of multiple distinct reinforcing composite layers that each undergo their own unique deformation mechanisms, a unique spatial functional form of mechanical properties with regions of differing levels of gradation within and between material layers, and layers with an undetectable gradation, load-dependent effective material properties, circumferential surface cracking, orthogonal microcracking in laminated sublayers and geometrically corrugated junctions between layers.

Materials design principles of ancient fish armour.

PubMed

Bruet, Benjamin J F; Song, Juha; Boyce, Mary C; Ortiz, Christine

2008-09-01

Knowledge of the structure-property-function relationships of dermal scales of armoured fish could enable pathways to improved bioinspired human body armour, and may provide clues to the evolutionary origins of mineralized tissues. Here, we present a multiscale experimental and computational approach that reveals the materials design principles present within individual ganoid scales from the 'living fossil' Polypterus senegalus. This fish belongs to the ancient family Polypteridae, which first appeared 96 million years ago during the Cretaceous period and still retains many of their characteristics. The mechanistic origins of penetration resistance (approximating a biting attack) were investigated and found to include the juxtaposition of multiple distinct reinforcing composite layers that each undergo their own unique deformation mechanisms, a unique spatial functional form of mechanical properties with regions of differing levels of gradation within and between material layers, and layers with an undetectable gradation, load-dependent effective material properties, circumferential surface cracking, orthogonal microcracking in laminated sublayers and geometrically corrugated junctions between layers.

Associations among hydrologic classifications and fish traits to support environmental flow standards

DOE Office of Scientific and Technical Information (OSTI.GOV)

McManamay, Ryan A; Bevelhimer, Mark S; Frimpong, Dr. Emmanuel A,

2014-01-01

Classification systems are valuable to ecological management in that they organize information into consolidated units thereby providing efficient means to achieve conservation objectives. Of the many ways classifications benefit management, hypothesis generation has been discussed as the most important. However, in order to provide templates for developing and testing ecologically relevant hypotheses, classifications created using environmental variables must be linked to ecological patterns. Herein, we develop associations between a recent US hydrologic classification and fish traits in order to form a template for generating flow ecology hypotheses and supporting environmental flow standard development. Tradeoffs in adaptive strategies for fish weremore » observed across a spectrum of stable, perennial flow to unstable intermittent flow. In accordance with theory, periodic strategists were associated with stable, predictable flow, whereas opportunistic strategists were more affiliated with intermittent, variable flows. We developed linkages between the uniqueness of hydrologic character and ecological distinction among classes, which may translate into predictions between losses in hydrologic uniqueness and ecological community response. Comparisons of classification strength between hydrologic classifications and other frameworks suggested that spatially contiguous classifications with higher regionalization will tend to explain more variation in ecological patterns. Despite explaining less ecological variation than other frameworks, we contend that hydrologic classifications are still useful because they provide a conceptual linkage between hydrologic variation and ecological communities to support flow ecology relationships. Mechanistic associations among fish traits and hydrologic classes support the presumption that environmental flow standards should be developed uniquely for stream classes and ecological communities, therein.« less

The decline of North American freshwater fishes

USGS Publications Warehouse

Walsh, Stephen J.; Jelks, Howard L.; Burkhead, Noel M.

2009-01-01

North America has a broad array of freshwater ecosystems because of the continent's complex geography and geological history. Within a multitude of habitats—that include streams, large rivers, natural lakes, springs, and wetlands—rich assemblages of fishes reside, representing diverse taxonomic groups with unique ecological requirements. They face an unprecedented conservation crisis.1 In the last few decades, the proportion of inland fishes of North America, which are considered imperiled or extinct, increased from 20 to 40%.2 Although extinctions have occurred, many species and populations are declining in range size and abundance. The fish biota of the continent as a whole remains diverse; however, we can take action to stem any further declines.

The Good, The Bad, and The Distant: Soundscape Cues for Larval Fish.

PubMed

Piercy, Julius J B; Smith, David J; Codling, Edward A; Hill, Adam J; Simpson, Stephen D

2016-01-01

Coral reef noise is an important navigation cue for settling reef fish larvae and can thus potentially affect reef population dynamics. Recent evidence has shown that fish are able to discriminate between the soundscapes of different types of habitat (e.g., mangrove and reef). In this study, we investigated whether discernible acoustic differences were present between sites within the same coral reef system. Differences in sound intensity and transient content were found between sites, but site-dependent temporal variation was also present. We discuss the implications of these findings for settling fish larvae.

[Trophic structure of river fish from Corral de San Luis, Magdalena river basin, Colombia Caribbean].

PubMed

Morales, Jenny; García-Alzate, Carlos A

2016-06-01

Ecological studies of species, such as the stomach content analysis, allow us to recognize different trophic groups, the importance of trophic levels and the interrelationships among species and other members of the community. In this investigation, we studied food habits, feeding variation and trophic relationships of the fishes present in streams of the Corral de San Luis drainage, Tubará, Atlántico Department, a part of the lower Magdalena River Basin in Colombian Caribbean. Fish samples of Awaous banana, Agonostomus monticola, Andinoacara latifrons, Hyphessobrycon proteus, Poecilia gillii, Gobiomorus dormitor and Synbranchus marmoratus were obtained using a seine (2x5 m, mesh 0.5 cm), from November 2012 to October 2013. To analyze their stomach contents, we used numeric (% N), volumetric (% V) and frequency of occurrence (% FO) methods, an emptiness coefficient (C.V), index of food item importance (I.A). Besides, physical and chemical habitat parameters were recorded on site. Information obtained was processed using multivariate statistical analysis, ecological indices, and null models: canonical correspondence analysis (CCA), principal component analysis (PCA), trophic niche amplitude (Shannon-Weaver H´) and trophic overlap (Morisita-Horn). We observed significant differences on food resources consumption (K-W= 20.86; p<0.05) among the studied species. They were classified according to their food habits as omnivores with a tendency towards insectivory (A. monticola H´0.60; A. latifrons H´0.43), herbivores with a tendency towards the consumption of algae (A. banana H´0.50; P. gillii H´0.54) and carnivores with a tendency towards insectivory (H. proteus H´0.23); benthic invertebrates and microalgae were found the most important food sources. A total of 65 food items were identified in this study: 21 for A. banana (2 unique, 19 shared), 40 for A. monticola (21 unique, 19 shared), 19 for A. latifrons (5 unique, 14 shared), 6 for H. proteus (1 unique, 5 shared) and P. gillii with 28 (4 unique, 24 shared). The canonical correspondence analysis showed that water conductivity, salinity and pH were the variables that directly influenced fish community structure at the sampled sites. The null model analyses showed that the group of fishes was significantly segregated (p= 0.001) along the trophic axis, with respect to shared food items, and that the segregation was not influenced or generated by competition. The Morisita-Horn index showed false trophic overlap (similarity of about 80 %) between A. banana and P. gillii. The first component of the PCA analysis was explained mainly by phytoplankton, and component two was correlated with items of animal origin. The fishes associated with PC1 were P. gillii and A. banana, with high ingestion values of microalgae. PC2 was explained by A. monticola with high numbers of food items of animal origin. The group of fishes studied behaved as an assemblage; given that the trophic interrelationships showed false trophic overlap, and that they did not exclude one another from the ecosystems, but instead, used different food resources and different physical spaces within their habitat.

Palaeolake isolation and biogeographical process of freshwater fishes in the Yellow River.

PubMed

Kang, Bin; Huang, Xiaoxia; Wu, Yunfei

2017-01-01

The Yellow River, one of the very few in the Earth, originated from many dispersive palaeolakes. Taking this unique advantage, we examined the roles of palaeolake isolation vs. geological processes vs. climate in determining current fish biogeographic pattern. We reviewed available data on fish species and their geographical distribution in the river, as well as palaeolake development, geological and climatic parameters. The 138 fish species recorded in the river could be divided into 8 biogeographic regions, corresponding to the distribution of palaeolakes and respective endemic species. Through variation partitioning analysis, palaeolake isolation was the most influential factor explaining 43.6% of the total variance on the current fish distribution. The Quaternary Ice Age produced a transitional distribution for fishes from the glacier to warm water, especially for the subfamily Schizothoracinae, which showed various degrees of specialisation along altitudes. We suggested that fish biogeography in the Yellow river was basically shaped by palaeolake isolation, and further carved under serials of geologic events and contemporary climate change.

Palaeolake isolation and biogeographical process of freshwater fishes in the Yellow River

PubMed Central

Wu, Yunfei

2017-01-01

The Yellow River, one of the very few in the Earth, originated from many dispersive palaeolakes. Taking this unique advantage, we examined the roles of palaeolake isolation vs. geological processes vs. climate in determining current fish biogeographic pattern. We reviewed available data on fish species and their geographical distribution in the river, as well as palaeolake development, geological and climatic parameters. The 138 fish species recorded in the river could be divided into 8 biogeographic regions, corresponding to the distribution of palaeolakes and respective endemic species. Through variation partitioning analysis, palaeolake isolation was the most influential factor explaining 43.6% of the total variance on the current fish distribution. The Quaternary Ice Age produced a transitional distribution for fishes from the glacier to warm water, especially for the subfamily Schizothoracinae, which showed various degrees of specialisation along altitudes. We suggested that fish biogeography in the Yellow river was basically shaped by palaeolake isolation, and further carved under serials of geologic events and contemporary climate change. PMID:28406965

Valuing recreational fishing quality at rivers and streams

NASA Astrophysics Data System (ADS)

Melstrom, Richard T.; Lupi, Frank; Esselman, Peter C.; Stevenson, R. Jan

2015-01-01

This paper describes an economic model that links the demand for recreational stream fishing to fish biomass. Useful measures of fishing quality are often difficult to obtain. In the past, economists have linked the demand for fishing sites to species presence-absence indicators or average self-reported catch rates. The demand model presented here takes advantage of a unique data set of statewide biomass estimates for several popular game fish species in Michigan, including trout, bass and walleye. These data are combined with fishing trip information from a 2008-2010 survey of Michigan anglers in order to estimate a demand model. Fishing sites are defined by hydrologic unit boundaries and information on fish assemblages so that each site corresponds to the area of a small subwatershed, about 100-200 square miles in size. The random utility model choice set includes nearly all fishable streams in the state. The results indicate a significant relationship between the site choice behavior of anglers and the biomass of certain species. Anglers are more likely to visit streams in watersheds high in fish abundance, particularly for brook trout and walleye. The paper includes estimates of the economic value of several quality change and site loss scenarios.

Fish Allergens at a Glance: Variable Allergenicity of Parvalbumins, the Major Fish Allergens

PubMed Central

Kuehn, Annette; Swoboda, Ines; Arumugam, Karthik; Hilger, Christiane; Hentges, François

2014-01-01

Fish is a common trigger of severe, food-allergic reactions. Only a limited number of proteins induce specific IgE-mediated immune reactions. The major fish allergens are the parvalbumins. They are members of the calcium-binding EF-hand protein family characterized by a conserved protein structure. They represent highly cross-reactive allergens for patients with specific IgE to conserved epitopes. These patients might experience clinical reactions with various fish species. On the other hand, some individuals have IgE antibodies directed against unique, species-specific parvalbumin epitopes, and these patients show clinical symptoms only with certain fish species. Furthermore, different parvalbumin isoforms and isoallergens are present in the same fish and might display variable allergenicity. This was shown for salmon homologs, where only a single parvalbumin (beta-1) isoform was identified as allergen in specific patients. In addition to the parvalbumins, several other fish proteins, enolases, aldolases, and fish gelatin, seem to be important allergens. New clinical and molecular insights advanced the knowledge and understanding of fish allergy in the last years. These findings were useful for the advancement of the IgE-based diagnosis and also for the management of fish allergies consisting of advice and treatment of fish-allergic patients. PMID:24795722

A genomic view of the NOD-like receptor family in teleost fish: Identification of a novel NLR subfamily in zebrafish

USGS Publications Warehouse

Laing, K.J.; Purcell, M.K.; Winton, J.R.; Hansen, J.D.

2008-01-01

Background. A large multigene family of NOD-like receptor (NLR) molecules have been described in mammals and implicated in immunity and apoptosis. Little information, however, exists concerning this gene family in non-mammalian taxa. This current study, therefore, provides an in-depth investigation of this gene family in lower vertebrates including extensive phylogenetic comparison of zebrafish NLRs with orthologs in tetrapods, and analysis of their tissue-specific expression. Results. Three distinct NLR subfamilies were identified by mining genome databases of various non-mammalian vertebrates; the first subfamily (NLR-A) resembles mammalian NODs, the second (NLR-B) resembles mammalian NALPs, while the third (NLR-C) appears to be unique to teleost fish. In zebrafish, NLR-A and NLR-B subfamilies contain five and six genes respectively. The third subfamily is large, containing several hundred NLR-C genes, many of which are predicted to encode a C-terminal B30.2 domain. This subfamily most likely evolved from a NOD3-like molecule. Gene predictions for zebrafish NLRs were verified using sequence derived from ESTs or direct sequencing of cDNA. Reverse-transcriptase (RT)-PCR analysis confirmed expression of representative genes from each subfamily in selected tissues. Conclusion. Our findings confirm the presence of multiple NLR gene orthologs, which form a large multigene family in teleostei. Although the functional significance of the three major NLR subfamilies is unclear, we speculate that conservation and abundance of NLR molecules in all teleostei genomes, reflects an essential role in cellular control, apoptosis or immunity throughout bony fish. ?? 2008 Laing et al; licensee BioMed Central Ltd.

Field-based evaluations of horizontal flat-plate fish screens, II: Testing of a unique off-stream channel device - The Farmers Screen

USGS Publications Warehouse

Mesa, Matthew G.; Rose, Brien P.; Copeland, Elizabeth S.

2012-01-01

Screens are installed at water diversion sites to reduce entrainment of fish. Recently, the Farmers Irrigation District (Oregon) developed a unique flat-plate screen (the “Farmers Screen”) that operates passively and may offer reduced installation and operating costs. To evaluate the effectiveness of this screen on fish, we conducted two separate field experiments. First, juvenile coho salmon Oncorhynchus kisutch were released over a working version of this screen under a range of inflows (0.02–0.42 m3/s) and diversion flows (0.02–0.34 m3/s) at different water depths. Mean approach velocities ranged from 0 to 5 cm/s and sweeping velocities ranged from 36 to 178 cm/s. Water depths over the screen surface ranged from 1 to 25 cm and were directly related to inflow. Passage of fish over the screen under these conditions did not severely injure them or cause delayed mortality, and no fish were observed becoming impinged on the screen surface. Second, juvenile coho salmon and steelhead O. mykiss were released at the upstream end of a 34-m flume and allowed to volitionally move downstream and pass over a 3.5-m section of the Farmers Screen to determine whether fish would refuse to pass over the screen after encountering its leading edge. For coho salmon, 75–95% of the fish passed over the screen within 5 min and 82–98% passed within 20 min, depending on hydraulic conditions. For steelhead, 47–90% of the fish passed over the screen within 5 min and 79–95% passed within 20 min. Our results indicate that when operated within its design criteria, the Farmers Screen provides safe and efficient downstream passage of juvenile salmonids under a variety of hydraulic conditions.

Towards improved behavioural testing in aquatic toxicology: Acclimation and observation times are important factors when designing behavioural tests with fish.

PubMed

Melvin, Steven D; Petit, Marie A; Duvignacq, Marion C; Sumpter, John P

2017-08-01

The quality and reproducibility of science has recently come under scrutiny, with criticisms spanning disciplines. In aquatic toxicology, behavioural tests are currently an area of controversy since inconsistent findings have been highlighted and attributed to poor quality science. The problem likely relates to limitations to our understanding of basic behavioural patterns, which can influence our ability to design statistically robust experiments yielding ecologically relevant data. The present study takes a first step towards understanding baseline behaviours in fish, including how basic choices in experimental design might influence behavioural outcomes and interpretations in aquatic toxicology. Specifically, we explored how fish acclimate to behavioural arenas and how different lengths of observation time impact estimates of basic swimming parameters (i.e., average, maximum and angular velocity). We performed a semi-quantitative literature review to place our findings in the context of the published literature describing behavioural tests with fish. Our results demonstrate that fish fundamentally change their swimming behaviour over time, and that acclimation and observational timeframes may therefore have implications for influencing both the ecological relevance and statistical robustness of behavioural toxicity tests. Our review identified 165 studies describing behavioural responses in fish exposed to various stressors, and revealed that the majority of publications documenting fish behavioural responses report extremely brief acclimation times and observational durations, which helps explain inconsistencies identified across studies. We recommend that researchers applying behavioural tests with fish, and other species, apply a similar framework to better understand baseline behaviours and the implications of design choices for influencing study outcomes. Copyright © 2017 Elsevier Ltd. All rights reserved.

Implications of climate change for potamodromous fishes.

PubMed

Beatty, Stephen J; Morgan, David L; Lymbery, Alan J

2014-06-01

There is little understanding of how climate change will impact potamodromous freshwater fishes. Since the mid 1970s, a decline in annual rainfall in south-western Australia (a globally recognized biodiversity hotspot) has resulted in the rivers of the region undergoing severe reductions in surface flows (ca. 50%). There is universal agreement amongst Global Climate Models that rainfall will continue to decline in this region. Limited data are available on the movement patterns of the endemic freshwater fishes of south-western Australia or on the relationship between their life histories and hydrology. We used this region as a model to determine how dramatic hydrological change may impact potamodromous freshwater fishes. Migration patterns of fishes in the largest river in south-western Australia were quantified over a 4 year period and were related to a number of key environmental variables including discharge, temperature, pH, conductivity and dissolved oxygen. Most of the endemic freshwater fishes were potamodromous, displaying lateral seasonal spawning migrations from the main channel into tributaries, and there were significant temporal differences in movement patterns between species. Using a model averaging approach, amount of discharge was clearly the best predictor of upstream and downstream movement for most species. Given past and projected reductions in surface flow and groundwater, the findings have major implications for future recruitment rates and population viabilities of potamodromous fishes. Freshwater ecosystems in drying climatic regions can only be managed effectively if such hydro-ecological relationships are considered. Proactive management and addressing existing anthropogenic stressors on aquatic ecosystems associated with the development of surface and groundwater resources and land use is required to increase the resistance and resilience of potamodromous fishes to ongoing flow reductions. © 2013 John Wiley & Sons Ltd.

Fishing-gear restrictions and biomass gains for coral reef fishes in marine protected areas.

PubMed

Campbell, Stuart J; Edgar, Graham J; Stuart-Smith, Rick D; Soler, German; Bates, Amanda E

2018-04-01

Considerable empirical evidence supports recovery of reef fish populations with fishery closures. In countries where full exclusion of people from fishing may be perceived as inequitable, fishing-gear restrictions on nonselective and destructive gears may offer socially relevant management alternatives to build recovery of fish biomass. Even so, few researchers have statistically compared the responses of tropical reef fisheries to alternative management strategies. We tested for the effects of fishery closures and fishing gear restrictions on tropical reef fish biomass at the community and family level. We conducted 1,396 underwater surveys at 617 unique sites across a spatial hierarchy within 22 global marine ecoregions that represented 5 realms. We compared total biomass across local fish assemblages and among 20 families of reef fishes inside marine protected areas (MPAs) with different fishing restrictions: no-take, hook-and-line fishing only, several fishing gears allowed, and sites open to all fishing gears. We included a further category representing remote sites, where fishing pressure is low. As expected, full fishery closures, (i.e., no-take zones) most benefited community- and family-level fish biomass in comparison with restrictions on fishing gears and openly fished sites. Although biomass responses to fishery closures were highly variable across families, some fishery targets (e.g., Carcharhinidae and Lutjanidae) responded positively to multiple restrictions on fishing gears (i.e., where gears other than hook and line were not permitted). Remoteness also positively affected the response of community-level fish biomass and many fish families. Our findings provide strong support for the role of fishing restrictions in building recovery of fish biomass and indicate important interactions among fishing-gear types that affect biomass of a diverse set of reef fish families. © 2017 Society for Conservation Biology.

Combined DNA-RNA Fluorescent In situ Hybridization (FISH) to Study X Chromosome Inactivation in Differentiated Female Mouse Embryonic Stem Cells

PubMed Central

Barakat, Tahsin Stefan; Gribnau, Joost

2014-01-01

Fluorescent in situ hybridization (FISH) is a molecular technique which enables the detection of nucleic acids in cells. DNA FISH is often used in cytogenetics and cancer diagnostics, and can detect aberrations of the genome, which often has important clinical implications. RNA FISH can be used to detect RNA molecules in cells and has provided important insights in regulation of gene expression. Combining DNA and RNA FISH within the same cell is technically challenging, as conditions suitable for DNA FISH might be too harsh for fragile, single stranded RNA molecules. We here present an easily applicable protocol which enables the combined, simultaneous detection of Xist RNA and DNA encoded by the X chromosomes. This combined DNA-RNA FISH protocol can likely be applied to other systems where both RNA and DNA need to be detected. PMID:24961515

Histamine production by Klebsiella pneumoniae and an incident of scombroid fish poisoning.

PubMed Central

Taylor, S L; Guthertz, L S; Leatherwood, M; Lieber, E R

1979-01-01

A histamine-producing strain of Klebsiella pneumoniae was isolated from a sample of tuna sashimi implicated in an outbreak of scombroid fish poisoning. None of the other nine gram-negative bacterial strains isolated from the tuna sashimi was capable of equivalent histamine production. Bacterial histamine production was monitored in a tuna fish infusion broth (TFIB), and the implicated K. pneumoniae was capable of producing 442 mg of histamine per 100 g of tuna in TFIB in 7 h under controlled incubation conditions. Only 12 of 50 other K. pneumoniae strains, representing 5 distinct biochemical types, which had been originally isolated from foods, were able to produce such levels of histamine in TFIB. No correlation was found between histamine production and other biochemical characteristics or antibiotic resistance. Of the 12 histamine-producing strains, 11 belonged to type 2, which is characterized as indole negative with positive reactions in the urea and Voges-Proskauer tests. However, only 50% of the type 2 strains examined produced high levels of histamine in TFIB. Additionally, the implicated K. pneumoniae strain and one other strain belonged to type 1, which is characterized by positive reactions in the indole, urea, and Voges-Proskauer tests. PMID:373626

Women fishing in Oceania

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chapman, M.D.

1987-09-01

Women's fishing in Oceania has been overlooked in most subsistence studies in the region and, as a consequence, there are few quantitative data available upon which to base an assessment of its importance. However, in the present study, the few data available on women's fishing in Oceania are examined, and these show that women contribute significantly to marine food yields in the region. Also, it is suggested that the highly regular nature of women's fishing makes women more reliable, and therefore more effective than men as suppliers of protein for subsistence. The implications of these findings for future development policiesmore » in the region are then discussed.« less

Desalination of fish sauce by electrodialysis: effect on selected aroma compounds and amino acid compositions.

PubMed

Chindapan, Nathamol; Devahastin, Sakamon; Chiewchan, Naphaporn; Sablani, Shyam S

2011-09-01

Fish sauce is an ingredient that exhibits unique flavor and is widely used by people in Southeast Asia. Fish sauce, however, contains a significant amount of salt (sodium chloride). Recently, electrodialysis (ED) has been successfully applied to reduce salt in fish sauce; however, no information is available on the effect of ED on changes in compounds providing aroma and taste of ED-treated fish sauce. The selected aroma compounds, amino acids, and sensory quality of the ED-treated fish sauce with various salt concentrations were then analyzed. The amounts of trimethylamine, 2,6-dimethylpyrazine, phenols, and all carboxylic acids except for hexanoic acid significantly decreased, whereas benzaldehyde increased significantly when the salt removal level was higher. The amounts of all amino acids decreased with the increased salt removal level. Significant difference in flavor and saltiness intensity among ED-treated fish sauce with various salt concentrations, as assessed by a discriminative test, were observed. Information obtained in this work can serve as a guideline for optimization of a process to produce low-sodium fish sauce by ED. It also forms a basis for further in-depth sensory analysis of low-sodium fish sauce. © 2011 Institute of Food Technologists®

Integrating Anisakis spp. parasites data and host genetic structure in the frame of a holistic approach for stock identification of selected Mediterranean Sea fish species.

PubMed

Mattiucci, S; Cimmaruta, R; Cipriani, P; Abaunza, P; Bellisario, B; Nascetti, G

2015-01-01

The unique environment of the Mediterranean Sea makes fish stock assessment a major challenge. Stock identification of Mediterranean fisheries has been based mostly from data on biology, morphometrics, artificial tags, otolith shape and fish genetics, with less effort on the use of parasites as biomarkers. Here we use some case studies comparing Mediterranean vs Atlantic fish stocks in a multidisciplinary framework. The generalized Procrustes Rotation (PR) was used to assess the association between host genetics and larval Anisakis spp. datasets on demersal (hake) and pelagic (horse mackerel, swordfish) species. When discordant results emerged, they were due to the different features of the data. While fish population genetics can detect changes over an evolutionary timescale, providing indications on the cohesive action of gene flow, parasites are more suitable biomarkers when considering fish stocks over smaller temporal and spatial scales, hence giving information of fish movements over their lifespan. Future studies on the phylogeographic analysis of parasites suitable as biomarkers, and that of their fish host, performed on the same genes, will represent a further tool to be included in multidisciplinary studies on fish stock structure.

Enzymes in Fermented Fish.

PubMed

Giyatmi; Irianto, H E

Fermented fish products are very popular particularly in Southeast Asian countries. These products have unique characteristics, especially in terms of aroma, flavor, and texture developing during fermentation process. Proteolytic enzymes have a main role in hydrolyzing protein into simpler compounds. Fermentation process of fish relies both on naturally occurring enzymes (in the muscle or the intestinal tract) as well as bacteria. Fermented fish products processed using the whole fish show a different characteristic compared to those prepared from headed and gutted fish. Endogenous enzymes like trypsin, chymotrypsin, elastase, and aminopeptidase are the most involved in the fermentation process. Muscle tissue enzymes like cathepsins, peptidases, transaminases, amidases, amino acid decarboxylases, glutamic dehydrogenases, and related enzymes may also play a role in fish fermentation. Due to the decreased bacterial number during fermentation, contribution of microbial enzymes to proteolysis may be expected prior to salting of fish. Commercial enzymes are supplemented during processing for specific purposes, such as quality improvement and process acceleration. In the case of fish sauce, efforts to accelerate fermentation process and to improve product quality have been studied by addition of enzymes such as papain, bromelain, trypsin, pepsin, and chymotrypsin. © 2017 Elsevier Inc. All rights reserved.

LANDSCAPE CHARACTERIZATION & NON-POINT SOURCE NITROGEN MODELING IN SUPPORT OF TMDL DEVELOPMENT IN THE NEUSE RIVER BASIN, NC

EPA Science Inventory

Pfesteria-like toxic- blooms have been implicated as the causative agent responsible for numerous outbreaks of fish lesions and fish kills in the Mid-Atlantic and southeastern U.S. An increase in frequency, intensity, and severity of toxic blooms in recent years is though...

Trophic linkages between headwater forests and downstream fish habitats: implications for forest and fish management.

Treesearch

Mark S. Wipfli

2005-01-01

This study examined the fluvial transport of invertebrates (aquatic and terrestrial) and coarse organic detritus from forested - headwaters in alternatives-to-clearcutting (ATC) harvest units to aquatic habitats downstream in the coastal mountains of southeastern Alaska. Fifty small streams (mean discharge 2.7 Ls-1, range 0.1-128.1 Ls-...

Coagulability and Rheology: Hematologic Benefits from Exercise, Fish, and Aspirin. Implications for Athletes and Nonathletes.

ERIC Educational Resources Information Center

Eichner, Edward R.

1986-01-01

Healthy hematologic adaptations to exercise are described. The benefits of increased performance for elite athletes and reduced risk of heart attack for the general population are stressed. The advisability of increased amounts of fish in the diet and low doses of aspirin to reduce coronary risk factors are discussed. (Author/MT)

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

PubMed

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.

Significance of Cooking Oil to Bioaccessibility of Dichlorodiphenyltrichloroethanes (DDTs) and Polybrominated Diphenyl Ethers (PBDEs) in Raw and Cooked Fish: Implications for Human Health Risk.

PubMed

Mi, Xiu-Bo; Su, Yang; Bao, Lian-Jun; Tao, Shu; Zeng, Eddy Y

2017-04-26

The present study examined the bioacessibility of DDTs and PBDEs in cooked fish (yellow grouper; Epinephelus awoara) with and without heating using the colon extended physiologically based extraction test. The bioaccessibility of DDTs and PBDEs increased from 60 and 26% in raw fish to 83 and 63%, respectively, after the addition of oil to raw fish. However, they decreased from 83 to 66% and from 63 to 40%, respectively, when oil-added fish were cooked. Human health risk assessment based on bioaccessible concentrations of DDTs and PBDEs in fish showed that the maximum allowable daily fish consumption rates decreased from 25, 59, and 86 g day -1 to 22, 53, and 77 g day -1 for children, youths, and adults, respectively, after fish were cooked with oil. These findings indicated that the significance of cooking oil to the bioaccessibility of DDTs and PBDEs in food should be considered in assessments of human health risk.

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

PubMed

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

2016-06-01

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

Fishing amplifies forage fish population collapses.

PubMed

Essington, Timothy E; Moriarty, Pamela E; Froehlich, Halley E; Hodgson, Emma E; Koehn, Laura E; Oken, Kiva L; Siple, Margaret C; Stawitz, Christine C

2015-05-26

Forage fish support the largest fisheries in the world but also play key roles in marine food webs by transferring energy from plankton to upper trophic-level predators, such as large fish, seabirds, and marine mammals. Fishing can, thereby, have far reaching consequences on marine food webs unless safeguards are in place to avoid depleting forage fish to dangerously low levels, where dependent predators are most vulnerable. However, disentangling the contributions of fishing vs. natural processes on population dynamics has been difficult because of the sensitivity of these stocks to environmental conditions. Here, we overcome this difficulty by collating population time series for forage fish populations that account for nearly two-thirds of global catch of forage fish to identify the fingerprint of fisheries on their population dynamics. Forage fish population collapses shared a set of common and unique characteristics: high fishing pressure for several years before collapse, a sharp drop in natural population productivity, and a lagged response to reduce fishing pressure. Lagged response to natural productivity declines can sharply amplify the magnitude of naturally occurring population fluctuations. Finally, we show that the magnitude and frequency of collapses are greater than expected from natural productivity characteristics and therefore, likely attributed to fishing. The durations of collapses, however, were not different from those expected based on natural productivity shifts. A risk-based management scheme that reduces fishing when populations become scarce would protect forage fish and their predators from collapse with little effect on long-term average catches.

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

PubMed Central

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

2015-01-01

Approximately 30 years ago, it was discovered that free-living bacteria isolated from cold ocean depths could produce polyunsaturated fatty acids (PUFA) such as eicosapentaenoic acid (EPA) (20:5n-3) or docosahexaenoic acid (DHA) (22:6n-3), two PUFA essential for human health. Numerous laboratories have also discovered that EPA- and/or DHA-producing bacteria, many of them members of the Shewanella genus, could be isolated from the intestinal tracts of omega-3 fatty acid-rich marine fish. If bacteria contribute omega-3 fatty acids to the host fish in general or if they assist some bacterial species in adaptation to cold, then cold freshwater fish or habitats should also harbor these producers. Thus, we undertook a study to see if these niches also contained omega-3 fatty acid producers. We were successful in isolating and characterizing unique EPA-producing strains of Shewanella from three strictly freshwater native fish species, i.e., lake whitefish (Coregonus clupeaformis), lean lake trout (Salvelinus namaycush), and walleye (Sander vitreus), and from two other freshwater nonnative fish, i.e., coho salmon (Oncorhynchus kisutch) and seeforellen brown trout (Salmo trutta). We were also able to isolate four unique free-living strains of EPA-producing Shewanella from freshwater habitats. Phylogenetic and phenotypic analyses suggest that one producer is clearly a member of the Shewanella morhuae species and another is sister to members of the marine PUFA-producing Shewanella baltica species. However, the remaining isolates have more ambiguous relationships, sharing a common ancestor with non-PUFA-producing Shewanella putrefaciens isolates rather than marine S. baltica isolates despite having a phenotype more consistent with S. baltica strains. PMID:26497452

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

PubMed

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

2016-01-01

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

Habitat loss and gain: Influence on habitat attractiveness for estuarine fish communities

NASA Astrophysics Data System (ADS)

Amorim, Eva; Ramos, Sandra; Elliott, Michael; Franco, Anita; Bordalo, Adriano A.

2017-10-01

Habitat structure and complexity influence the structuring and functioning of fish communities. Habitat changes are one of the main pressures affecting estuarine systems worldwide, yet the degree and rate of change and its impact on fish communities is still poorly understood. In order to quantify historical modifications in habitat structure, an ecohydrological classification system using physiotopes, i.e. units with homogenous abiotic characteristics, was developed for the lower Lima estuary (NW Portugal). Field data, aerial imagery, historical maps and interpolation methods were used to map input variables, including bathymetry, substratum (hard/soft), sediment composition, hydrodynamics (current velocity) and vegetation coverage. Physiotopes were then mapped for the years of 1933 and 2013 and the areas lost and gained over the 80 years were quantified. The implications of changes for the benthic and demersal fish communities using the lower estuary were estimated using the attractiveness to those communities of each physiotope, while considering the main estuarine habitat functions for fish, namely spawning, nursery, feeding and refuge areas and migratory routes. The lower estuary was highly affected due to urbanisation and development and, following a port/harbour expansion, its boundary moved seaward causing an increase in total area. Modifications led to the loss of most of its sandy and saltmarsh intertidal physiotopes, which were replaced by deeper subtidal physiotopes. The most attractive physiotopes for fish (defined as the way in which they supported the fish ecological features) decreased in area while less attractive ones increased, producing an overall lower attractiveness of the studied area in 2013 compared to 1933. The implications of habitat alterations for the fish using the estuary include potential changes in the nursery carrying capacity and the functioning of the fish community. The study also highlighted the poor knowledge of the impacts of habitat changes on fish due to coastal development and urbanisation and emphasises that ecosystem management and conservation will benefit from a wider understanding of habitat functional roles and habitat changes influencing the functioning and structure of the fish communities.

Overestimating Fish Counts by Non-Instantaneous Visual Censuses: Consequences for Population and Community Descriptions

PubMed Central

Ward-Paige, Christine; Mills Flemming, Joanna; Lotze, Heike K.

2010-01-01

Background Increasingly, underwater visual censuses (UVC) are used to assess fish populations. Several studies have demonstrated the effectiveness of protected areas for increasing fish abundance or provided insight into the natural abundance and structure of reef fish communities in remote areas. Recently, high apex predator densities (>100,000 individuals·km−2) and biomasses (>4 tonnes·ha−1) have been reported for some remote islands suggesting the occurrence of inverted trophic biomass pyramids. However, few studies have critically evaluated the methods used for sampling conspicuous and highly mobile fish such as sharks. Ideally, UVC are done instantaneously, however, researchers often count animals that enter the survey area after the survey has started, thus performing non-instantaneous UVC. Methodology/Principal Findings We developed a simulation model to evaluate counts obtained by divers deploying non-instantaneous belt-transect and stationary-point-count techniques. We assessed how fish speed and survey procedure (visibility, diver speed, survey time and dimensions) affect observed fish counts. Results indicate that the bias caused by fish speed alone is huge, while survey procedures had varying effects. Because the fastest fishes tend to be the largest, the bias would have significant implications on their biomass contribution. Therefore, caution is needed when describing abundance, biomass, and community structure based on non-instantaneous UVC, especially for highly mobile species such as sharks. Conclusions/Significance Based on our results, we urge that published literature state explicitly whether instantaneous counts were made and that survey procedures be accounted for when non-instantaneous counts are used. Using published density and biomass values of communities that include sharks we explore the effect of this bias and suggest that further investigation may be needed to determine pristine shark abundances and the existence of inverted biomass pyramids. Because such studies are used to make important management and conservation decisions, incorrect estimates of animal abundance and biomass have serious and significant implications. PMID:20661304

36 CFR 261.70 - Issuance of regulations.

Code of Federal Regulations, 2010 CFR

2010-07-01

...) Protection of property, roads, or trails. (4) Protection of threatened, endangered, rare, unique, or vanishing species of plants, animals, birds or fish, or special biological communities. (5) Protection of...

Why are reproductively parasitic fish males so small?—influence of tactic-specific selection

NASA Astrophysics Data System (ADS)

Ota, Kazutaka; Kohda, Masanori; Sato, Tetsu

2010-12-01

Despite the wide prevalence of alternative reproductive tactics, little attention has been paid to why reproductively parasitic males are so small. In this study, we tackled this issue in a shell-brooding fish Lamprologus callipterus. Sneaky `dwarf males' of this fish remain much smaller than bourgeois conspecifics throughout their life and employ a unique parasitic tactic, i.e. entering into a gastropod shell where a female is spawning, passing through the space between the female and shell wall and staying behind her to ejaculate throughout the spawning event. Here, we tested the prediction that they remain small to get past her through the shell spaces by interpopulation comparison. We showed, across populations, a negative allometry for sexual size dimorphism, an exponential increase of female size with an increase in shell size and a negative correlation between the magnitude of sexual size dimorphism and shell size. These results suggest that the inner spaces strongly regulate dwarf male size. We conclude that the small bodies of dwarf males arise from adaptation to their unique reproductive behaviour.

Evolution of Fish-Shaped Reptiles (reptilia: Ichthyopterygia) in Their Physical Environments and Constraints

NASA Astrophysics Data System (ADS)

Motani, Ryosuke

2005-01-01

Ichthyosaurs were a group of Mesozoic marine reptiles that evolved fish-shaped body outlines. They are unique in several anatomical characters, including the possession of enormous eyeballs sometimes exceeding 25 cm and an enlarged manus with sometimes up to 20 bones in a single digit, or 10 digits per manus. They are also unique in that their biology has been studied from the perspective of physical constraints, which allowed estimation of such characteristics as optimal cruising speed, visual sensitivity, and even possible basal metabolic rate ranges. These functional inferences, although based on physical principles, obviously contain errors arising from the limitations of fossilized data, but are necessarily stronger than the commonly made inferences based on superficial correlations among quantities without mechanical or optical explanations for why such correlations exist.

Parrotfish sex ratios recover rapidly in Bermuda following a fishing ban

NASA Astrophysics Data System (ADS)

O'Farrell, Shay; Luckhurst, Brian E.; Box, Stephen J.; Mumby, Peter J.

2016-06-01

Parrotfishes are an ecologically and commercially important teleost group whose grazing contributes to maintaining coral-dominated states on hermatypic reefs. However, overfishing has skewed sex ratios of Atlantic parrotfishes because fishing has disproportionate impacts on larger individuals, and males are generally larger than females. Whether protection from fishing may allow sex ratios to return to equilibrium is unknown, as fishing can induce irreversible ecological and/or evolutionary shifts. Bermuda banned trap fishing in 1990, creating a unique opportunity to analyse long-term responses of Atlantic parrotfishes to release from fishing. We found that sex ratios of four common parrotfishes were initially skewed, with male proportions ranging from 0.04 to 0.18. However, male proportions rebounded within 3-4 yr, equilibrating at values ranging from 0.36 to 0.54, similar to those reported at unfished sites in the region. Our results are encouraging for regional efforts to recover lost grazing function by restoring overfished herbivore populations.

Largest global shark biomass found in the northern Galápagos Islands of Darwin and Wolf.

PubMed

Salinas-de-León, Pelayo; Acuña-Marrero, David; Rastoin, Etienne; Friedlander, Alan M; Donovan, Mary K; Sala, Enric

2016-01-01

Overfishing has dramatically depleted sharks and other large predatory fishes worldwide except for a few remote and/or well-protected areas. The islands of Darwin and Wolf in the far north of the Galapagos Marine Reserve (GMR) are known for their large shark abundance, making them a global scuba diving and conservation hotspot. Here we report quantitative estimates of fish abundance at Darwin and Wolf over two consecutive years using stereo-video surveys, which reveal the largest reef fish biomass ever reported (17.5 t [Formula: see text] on average), consisting largely of sharks. Despite this, the abundance of reef fishes around the GMR, such as groupers, has been severely reduced because of unsustainable fishing practices. Although Darwin and Wolf are within the GMR, they were not fully protected from fishing until March 2016. Given the ecological value and the economic importance of Darwin and Wolf for the dive tourism industry, the current protection should ensure the long-term conservation of this hotspot of unique global value.

Exceptional fossil preservation demonstrates a new mode of axial skeleton elongation in early ray-finned fishes.

PubMed

Maxwell, Erin E; Furrer, Heinz; Sánchez-Villagra, Marcelo R

2013-01-01

Elongate body plans have evolved independently multiple times in vertebrates, and involve either an increase in the number or in the length of the vertebrae. Here, we describe a new mechanism of body elongation in saurichthyids, an extinct group of elongate early ray-finned fishes. The rare preservation of soft tissue in a specimen of Saurichthys curionii from the Middle Triassic (Ladinian) of Switzerland provides significant new information on the relationship between the musculature and the skeleton. This new fossil material shows that elongation in these fishes results from doubling the number of neural arch-like elements per myomeric segment. This unique way of generating an elongate body plan demonstrates the evolutionary lability of the vertebral column in non-teleostean fishes. The shape and arrangement of preserved myosepta suggest that S. curionii was not a highly flexible fish, in spite of the increase in the number of neural arch-like elements.

A contemporary review of seafood allergy.

PubMed

Hajeb, Parvaneh; Selamat, Jinap

2012-06-01

Seafood is common item in the world diet; Asian countries have the highest rates of fish consumption in the world, which is higher than world average. Several studies have been conducted on the epidemiology and clinical characteristics of seafood allergy in different countries, and some of the fish and seafood allergens unique to those regions have been characterized. Review on published data showed that seafood allergy is very ubiquitous in some regions of the world. Fish and shellfish are the most common seafood that cause adverse allergic reactions among nations; the symptoms ranged from oral allergy syndromes to urticaria and anaphylaxis. The major identified allergens are parvalbumin in fish and tropomyosin in shellfish. Nevertheless, such studies are lacking from some regions with high fish and seafood consumption. Furthermore, the published data are mostly from small groups of populations, which large-scale epidemiological studies need to be performed.

Phenotypic variation in Lactococcus lactis subsp. lactis isolates derived from intestinal tracts of marine and freshwater fish.

PubMed

Itoi, S; Yuasa, K; Washio, S; Abe, T; Ikuno, E; Sugita, H

2009-09-01

We compared phenotypic characteristics of Lactococcus lactis subsp. lactis derived from different sources including the intestinal tract of marine fish and freshwater fish, and cheese starter culture. In the phylogenetic analysis based on partial 16S rRNA gene nucleotide sequences (1371 bp), freshwater fish-, marine fish- and cheese starter culture-derived strains were identical to that of L. lactis subsp. lactis previously reported. Fermentation profiles determined using the API 50 CH system were similar except for fermentation of several sugars including l-arabinose, mannitol, amygdalin, saccharose, trehalose, inulin and gluconate. The strains did have distinct levels of halotolerance: marine fish-derived strains > cheese starter-derived strain > freshwater fish-derived isolate. Lactococcus lactis subsp. lactis showed extensive diversity in phenotypic adaptation to various environments. The phenotypic properties of these strains suggested that L. lactis subsp. lactis strains from fish intestine have additional functions compared with the cheese starter-derived strain that has previously described. The unique phenotypic traits of the fish intestinal tract-derived L. lactis subsp. lactis might make them useful as a probiotics in aquaculture, and contribute to the development of functional foods and novel food additives, since the strains derived from fish intestines might have additional functions such as antibacterial activity.

Application of biomimetics principles in space optics

NASA Astrophysics Data System (ADS)

Remisova, K.; Hudec, R.

2017-09-01

The principles of biomimetics have been successfully applied in space optics, e.g. in Lobster-Eye X-ray optical systems. However, the recent increase in knowledge on vision of sea animals, especially on mirror eyes of scallops, crustaceans, and deep sea fishes, makes possible to consider other such applications. Especially the discoveries of mirror eyes of the deep sea fishes Dolichopteryx longipes and Rhynchohyalus natalensis are promising because of their unique arrangements and likely active optics.

Temperature and diet effects on omnivorous fish performance: Implications for the latitudinal diversity gradient in herbivorous fishes

USGS Publications Warehouse

Behrens, M.D.; Lafferty, K.D.

2007-01-01

Herbivorous fishes show a clear latitudinal diversity gradient, making up a larger proportion of the fish species in a community in tropical waters than in temperate waters. One proposed mechanism that could drive this gradient is a physiological constraint due to temperature. One prediction based on this mechanism is that if herbivorous fishes could shift their diet to animal material, they would be better able to grow, survive, and reproduce in cold waters. We tested this prediction on the omnivore Girella nigricans under different temperature and diet regimes using RNA-DNA ratios as an indicator of performance. Fish had increased performance (100%) at low temperatures (12??C) when their diet was supplemented with animal material. In contrast, at higher temperatures (17, 22, and 27??C) fish showed no differences between diets. This indicates that omnivorous fishes could increase their performance at low temperatures by consuming more animal matter. This study supports the hypothesis that a relative increase in the nutritional value of plant material at warmer temperatures could drive the latitudinal diversity gradient in herbivorous fishes. ?? 2007 NRC.

Characteristic Features and Contributory Factors in Fatal Ciguatera Fish Poisoning—Implications for Prevention and Public Education

PubMed Central

Chan, Thomas Y. K.

2016-01-01

In this review, the main objective was to describe the characteristic features of fatal ciguatera fish poisoning and identify contributory factors, with a view to promote prevention and public education. Ciguatera-related deaths, although rare, have been reported from the Pacific, Caribbean, and Indian Ocean regions. The clinical features were generally dominated by convulsions and coma, with various focal neurological signs. Several contributory factors could be identified, including consumption of ciguatoxin (CTX)-rich fish parts (viscera and head) in larger amounts, the most ciguatoxic fish species (e.g., Gymnothorax flavimarginatus) and reef fish collected after storms and individuals' susceptibility. Mass ciguatera fish poisoning with mortalities also occurred when G. flavimarginatus and other ciguatoxic fish species were shared in gatherings and parties. The characteristic features of fatal ciguatera fish poisoning must be recognized early. The public should be repeatedly reminded to avoid eating the most ciguatoxic fish species and the CTX-rich parts of reef fish. To prevent mass poisoning in gatherings and parties, the most ciguatoxic fish species and potentially toxic fish species must be avoided. Particularly after hits by disastrous storms, it is important to monitor the toxicity of reef fish and the incidence rates of ciguatera. PMID:26787145

Characteristic Features and Contributory Factors in Fatal Ciguatera Fish Poisoning--Implications for Prevention and Public Education.

PubMed

Chan, Thomas Y K

2016-04-01

In this review, the main objective was to describe the characteristic features of fatal ciguatera fish poisoning and identify contributory factors, with a view to promote prevention and public education. Ciguatera-related deaths, although rare, have been reported from the Pacific, Caribbean, and Indian Ocean regions. The clinical features were generally dominated by convulsions and coma, with various focal neurological signs. Several contributory factors could be identified, including consumption of ciguatoxin (CTX)-rich fish parts (viscera and head) in larger amounts, the most ciguatoxic fish species (e.g.,Gymnothorax flavimarginatus) and reef fish collected after storms and individuals' susceptibility. Mass ciguatera fish poisoning with mortalities also occurred when G. flavimarginatus and other ciguatoxic fish species were shared in gatherings and parties. The characteristic features of fatal ciguatera fish poisoning must be recognized early. The public should be repeatedly reminded to avoid eating the most ciguatoxic fish species and the CTX-rich parts of reef fish. To prevent mass poisoning in gatherings and parties, the most ciguatoxic fish species and potentially toxic fish species must be avoided. Particularly after hits by disastrous storms, it is important to monitor the toxicity of reef fish and the incidence rates of ciguatera. © The American Society of Tropical Medicine and Hygiene.

Fast-moving soft electronic fish.

PubMed

Li, Tiefeng; Li, Guorui; Liang, Yiming; Cheng, Tingyu; Dai, Jing; Yang, Xuxu; Liu, Bangyuan; Zeng, Zedong; Huang, Zhilong; Luo, Yingwu; Xie, Tao; Yang, Wei

2017-04-01

Soft robots driven by stimuli-responsive materials have unique advantages over conventional rigid robots, especially in their high adaptability for field exploration and seamless interaction with humans. The grand challenge lies in achieving self-powered soft robots with high mobility, environmental tolerance, and long endurance. We are able to advance a soft electronic fish with a fully integrated onboard system for power and remote control. Without any motor, the fish is driven solely by a soft electroactive structure made of dielectric elastomer and ionically conductive hydrogel. The electronic fish can swim at a speed of 6.4 cm/s (0.69 body length per second), which is much faster than previously reported untethered soft robotic fish driven by soft responsive materials. The fish shows consistent performance in a wide temperature range and permits stealth sailing due to its nearly transparent nature. Furthermore, the fish is robust, as it uses the surrounding water as the electric ground and can operate for 3 hours with one single charge. The design principle can be potentially extended to a variety of flexible devices and soft robots.

Fast-moving soft electronic fish

PubMed Central

Li, Tiefeng; Li, Guorui; Liang, Yiming; Cheng, Tingyu; Dai, Jing; Yang, Xuxu; Liu, Bangyuan; Zeng, Zedong; Huang, Zhilong; Luo, Yingwu; Xie, Tao; Yang, Wei

2017-01-01

Soft robots driven by stimuli-responsive materials have unique advantages over conventional rigid robots, especially in their high adaptability for field exploration and seamless interaction with humans. The grand challenge lies in achieving self-powered soft robots with high mobility, environmental tolerance, and long endurance. We are able to advance a soft electronic fish with a fully integrated onboard system for power and remote control. Without any motor, the fish is driven solely by a soft electroactive structure made of dielectric elastomer and ionically conductive hydrogel. The electronic fish can swim at a speed of 6.4 cm/s (0.69 body length per second), which is much faster than previously reported untethered soft robotic fish driven by soft responsive materials. The fish shows consistent performance in a wide temperature range and permits stealth sailing due to its nearly transparent nature. Furthermore, the fish is robust, as it uses the surrounding water as the electric ground and can operate for 3 hours with one single charge. The design principle can be potentially extended to a variety of flexible devices and soft robots. PMID:28435879

Sargassum-associated mobile fauna communities in the Caribbean, Gulf of Mexico, and Sargasso Sea

NASA Astrophysics Data System (ADS)

Martin, L.; Schell, J. M.; Goodwin, D.; Biggs, D.; Siuda, A. N.

2016-02-01

Sargassum natans and S. fluitans are entirely pelagic, offering a pseudo-benthic structural habitat for an associated community of mobile fauna. In turn, the mobile fauna community supports foraging seabirds, fish, and turtles. Recent satellite observations suggest Sargassum in the Sargasso Sea is seeded annually from the Gulf of Mexico. Furthermore, the Caribbean is in the midst of a Sargassum inundation that appears disconnected in origin from the Sargasso Sea and Gulf of Mexico. Sargassum and fauna were collected via dip net during spring and summer 2015 from the Gulf of Mexico, Sargasso Sea and Eastern Caribbean to study the impacts that region, aggregation pattern (isolated clump, windrow, mat), and Sargassum variety morphology have on mobile fauna community composition. Sargassum from all three regions shared five common (frequency >10%) species: flatworm spp., Portunus sayi, Litiopa melanostoma, Leander tenuicornis, and Latreutes fucorum). The Gulf presented the most unique species (9 unique / 16 total) followed by the Sargasso Sea (5 unique / 12 total) and the Caribbean (1 unique / 6 total). The majority of species unique to the Gulf of Mexico were juvenile fish while those in the Caribbean and Sargasso Sea were benthic-like species residing on the Sargassum itself. Differences in the morphological forms of Sargassum had a marked effect on fauna diversity and abundance. In all three regions, fewer individuals and species were found on the broad-leafed, less compact S. natans VIII than on the denser S. natans I and S. fluitans III. This study identifies the differences in macrofauna abundance and diversity between varieties of Sargassum and highlights the potential for dramatic community changes that could result from largescale Sargassum blooms and species shifts. Any shift in these keystone communities could result in negative cascading effects on seabirds, economically important fish populations, and juvenile turtles which use the seaweed as a nursery habitat.

Size-dependent social attraction and repulsion explains the decision of Atlantic cod Gadus morhua to enter baited pots.

PubMed

Anders, N; Fernö, A; Humborstad, O-B; Løkkeborg, S; Rieucau, G; Utne-Palm, A C

2017-12-01

The present study tested whether the presence of already retained fishes inside baited fish pots acted as a social attraction and affected the entrance probability of Atlantic cod Gadus morhua in a fjord in northern Norway. Video analysis revealed that the probability of an entrance initially increased with the presence of low numbers of fishes inside the pot, but subsequently decreased at a critical number of caught fishes. The critical number was dependent on the size of the G. morhua attempting to enter. This demonstrates that social attraction and repulsion play a role in G. morhua pot fishing and has important implications for the capture efficiency of fisheries executed with pots. © 2017 The Fisheries Society of the British Isles.

Influences on the Use of the "Fishing: Get in the Habitat! MinnAqua Leader's Guide" and Implications for Curriculum Dissemination

ERIC Educational Resources Information Center

Athman Ernst, Julie

2010-01-01

The "Fishing: Get in the Habitat! MinnAqua Leader's Guide" is a curriculum created by the Minnesota Department of Natural Resources for educators working primarily with children in grades three through five in formal and nonformal education settings. Like many agency-developed supplemental educational resources, the Leader's Guide is…

Statistical Analysis of Streambed Sediment Grain Size Distributions: Implications for Environmental Management and Regulatory Policy

Treesearch

Brenda Rosser; Matt O' Connor

2007-01-01

Fish habitat in cold water streams in many northwestern California watersheds has been declared degraded under provisions of the Federal Clean Water Act, contributing to listings of anadromous fish species under the Endangered Species Act. It is believed that past and present land management activities induce erosion that contributes excess sand-size and finer sediment...

Measurement of organochlorines in commercial over-the-counter fish oil preparations: implications for dietary and therapeutic recommendations for omega-3 fatty acids and a review of the literature.

PubMed

Melanson, Stacy Foran; Lewandrowski, Elizabeth Lee; Flood, James G; Lewandrowski, Kent B

2005-01-01

The consumption of fish high in omega-3 fatty acids is advocated by the American Heart Association to decrease the risk of coronary artery disease. However, fish contain environmental toxins such as mercury, polychlorinated biphenyls, and organochlorine pesticides, which may negate the beneficial cardiovascular effects of fish meals. Toxin levels vary depending on both the fish source and the specific toxin, and neither farm-raised nor wild fish are toxin free. Fish oil supplements also prevent the progression of coronary artery disease and reduce cardiovascular mortality. However, only sparse data exist on the level of toxins in fish oil. In a previous study we showed that the amount of mercury in 5 over-the-counter brands of fish oil was negligible. To determine the concentrations of polychlorinated biphenyls and other organochlorines in 5 over-the-counter preparations of fish oil. The contents of 5 commercial fish oil brands were sent for organochlorine analysis. The levels of polychlorinated biphenyls and organochlorines were all below the detectable limit. Fish oil supplements are more healthful than the consumption of fish high in organochlorines. Fish oils provide the benefits of omega-3 fatty acids without the risk of toxicity. In addition, fish oil supplements have been helpful in a variety of diseases, including bipolar disorder and depression.

Divergent Expression Patterns and Function Implications of Four nanos Genes in a Hermaphroditic Fish, Epinephelus coioides.

PubMed

Sun, Zhi-Hui; Wang, Yang; Lu, Wei-Jia; Li, Zhi; Liu, Xiao-Chun; Li, Shui-Sheng; Zhou, Li; Gui, Jian-Fang

2017-03-23

Multiple nanos genes have been characterized in several fishes, but the functional implications of their various expression patterns remain unclear. In this study, we identified and characterized four nanos genes from a hermaphroditic fish orange-spotted grouper, Epinephelus coioides . Ecnanos1a and Ecnanos1b show divergent expression patterns, and the dynamic expression change of Ecnanos1a in pituitaries during sex change is associated with testis differentiation and spermatogenesis. Ecnanos2 and Ecnanos3 might be germline stem cells (GSCs) and primordial germ cells (PGCs)-specific markers, respectively. Significantly, Ecnanos3 3'-untranslated region (UTR) is necessary for PGC specific expression, where a non-canonical "GCACGTTT" sequence is required for miR-430-mediated repression of Ecnanos3 RNA. Furthermore, grouper Dead end (Dnd) can relieve miR-430 repression in PGCs by associating with a 23 bp U-rich region (URR) in Ecnanos3 3'-UTR. The current study revealed the functional association of multiple nanos genes with PGC formation and germ cell development in orange-spotted grouper, and opened up new possibilities for developing biotechnologies through utilizing the associations between Ecnanos3 and PGCs or between Ecnanos2 and GSCs in the hermaphroditic fish.

An injectable acoustic transmitter for juvenile salmon

DOE PAGES

Deng, Zhiqun; Carlson, Thomas J.; Li, Huidong; ...

2015-01-29

Salmon recovery, and the potential detrimental effects of dams on fish, has been attracting national attention in due to great environmental and economic implications. Acoustic Telemetry has been the primary method for studying salmon passage. However, the size of the existing transmitters limits the minimum size of fish that can be studied, introducing bias to the study results. We developed the first acoustic fish transmitter that can be implanted by injection instead of surgery. The new injectable transmitter offers improved performance and 30% weight reduction. Because the new transmitter costs significantly less to use, substantially reduces adverse effects of implantation,more » and provides additional biological benefits for tagged fish, it will become the enabling technology for studying migration behavior and survival of species and sizes of fish that have never been studied before. This will lead to critical information for salmon recovery and the development of fish-friendly hydroelectric systems.« less

An injectable acoustic transmitter for juvenile salmon

DOE Office of Scientific and Technical Information (OSTI.GOV)

Deng, Zhiqun; Carlson, Thomas J.; Li, Huidong

Salmon recovery, and the potential detrimental effects of dams on fish, has been attracting national attention in due to great environmental and economic implications. Acoustic Telemetry has been the primary method for studying salmon passage. However, the size of the existing transmitters limits the minimum size of fish that can be studied, introducing bias to the study results. We developed the first acoustic fish transmitter that can be implanted by injection instead of surgery. The new injectable transmitter offers improved performance and 30% weight reduction. Because the new transmitter costs significantly less to use, substantially reduces adverse effects of implantation,more » and provides additional biological benefits for tagged fish, it will become the enabling technology for studying migration behavior and survival of species and sizes of fish that have never been studied before. This will lead to critical information for salmon recovery and the development of fish-friendly hydroelectric systems.« less

Endocrine active chemicals and endocrine disruption in Minnesota streams and lakes: implications for aquatic resources, 1994-2008

USGS Publications Warehouse

Lee, Kathy E.; Schoenfuss, Heiko L.; Barber, Larry B.; Writer, Jeff H.; Blazer, Vicki; Keisling, Richard L.; Ferrey, Mark L.

2010-01-01

Although these studies indicate that wastewater-treatment plant effluent is a conduit for endocrine active chemicals to surface waters, endocrine active chemicals also were present in surface waters with no obvious wastewater-treatment plant effluent sources. Endocrine active chemicals were detected and indicators of endocrine disruption in fish were measured at numerous sites upstream from discharge of wastewater-treatment plant effluent. These observations indicate that other unidentified sources of endocrine active chemicals exist, such as runoff from land surfaces, atmospheric deposition, inputs from onsite septic systems, or other groundwater sources. Alternatively, some endocrine active chemicals may not yet have been identified or measured. The presence of biological indicators of endocrine disruption in male fish indicates that the fish are exposed to endocrine active chemicals. However indicators of endocrine disruption in male fish does not indicate an effect on fish reproduction or changes in fish populations.

Introducing a Novel Media to Improve the Recovery of Culturable Bacteria from the Fish Parasite Anisakis spp. larvae (Nematoda: Anisakidae).

PubMed

Svanevik, Cecilie S; Lunestad, Bjørn T

2017-09-01

This paper describes a cultivation method to increase the recovery of bacteria from the marine muscle-invading parasitic nematode larvae of Anisakis spp. These larvae hold a high and complex population of accumulated bacteria, originating from seawater, crustaceans, fish, and marine mammals, all involved in the lifecycle of Anisakis. Two in-house agars based on fish juice prepared by either mechanical or enzymatic degradation of the fish tissue, were made. The Anisakis larvae were homogenised prior to cultivation on the in-house fish juice agars and the bacterial numbers and diversity were compared to those obtained applying the commercially available Marine Agar and Iron Agar Lyngby. Bacterial colonies of unique appearance were subcultured and identified by 16S rRNA gene sequencing. Totally three of twenty identified taxa were found on the in-house fish juice agars only. Fish juice agar prepared enzymatically would be the best supplementary agar, as this agar gave significantly higher heterotrophic plate counts, compared to mechanical preparation. The enzymatically prepared fish juice gave more suitable agar quality, was more resource efficient, and had apparently increased nutrient density and availability.

Recommendations for control of pathogens and infectious diseases in fish research facilities☆

PubMed Central

Kent, Michael L.; Feist, Stephen W.; Harper, Claudia; Hoogstraten-Miller, Shelley; Mac Law, J.; Sánchez-Morgado, José M.; Tanguay, Robert L.; Sanders, George E.; Spitsbergen, Jan M.; Whipps, Christopher M.

2012-01-01

Concerns about infectious diseases in fish used for research have risen along with the dramatic increase in the use of fish as models in biomedical research. In addition to acute diseases causing severe morbidity and mortality, underlying chronic conditions that cause low-grade or subclinical infections may confound research results. Here we present recommendations and strategies to avoid or minimize the impacts of infectious agents in fishes maintained in the research setting. There are distinct differences in strategies for control of pathogens in fish used for research compared to fishes reared as pets or in aquaculture. Also, much can be learned from strategies and protocols for control of diseases in rodents used in research, but there are differences. This is due, in part, the unique aquatic environment that is modified by the source and quality of the water provided and the design of facilities. The process of control of pathogens and infectious diseases in fish research facilities is relatively new, and will be an evolving process over time. Nevertheless, the goal of documenting, detecting, and excluding pathogens in fish is just as important as in mammalian research models. PMID:18755294

Recommendations for control of pathogens and infectious diseases in fish research facilities

USGS Publications Warehouse

Kent, M.L.; Feist, S.W.; Harper, C.; Hoogstraten-Miller, S.; Law, J.M.; Sanchez-Morgado, J. M.; Tanguay, R.L.; Sanders, G.E.; Spitsbergen, J.M.; Whipps, Christopher M.

2009-01-01

Concerns about infectious diseases in fish used for research have risen along with the dramatic increase in the use of fish as models in biomedical research. In addition to acute diseases causing severe morbidity and mortality, underlying chronic conditions that cause low-grade or subclinical infections may confound research results. Here we present recommendations and strategies to avoid or minimize the impacts of infectious agents in fishes maintained in the research setting. There are distinct differences in strategies for control of pathogens in fish used for research compared to fishes reared as pets or in aquaculture. Also, much can be learned from strategies and protocols for control of diseases in rodents used in research, but there are differences. This is due, in part, the unique aquatic environment that is modified by the source and quality of the water provided and the design of facilities. The process of control of pathogens and infectious diseases in fish research facilities is relatively new, and will be an evolving process over time. Nevertheless, the goal of documenting, detecting, and excluding pathogens in fish is just as important as in mammalian research models.

EPA Office of Water (OW): Fish Consumption Advisories and Fish Tissue Sampling Stations NHDPlus Indexed Datasets

EPA Pesticide Factsheets

The Fish Consumption Advisories dataset contains information on Fish Advisory events that have been indexed to the EPA Office of Water NHDPlus v2.1 hydrology and stored in the Reach Addressing Database (RAD). NHDPlus is a database that interconnects and uniquely identifies the millions of stream segments or reaches that comprise the Nations' surface water drainage system. NHDPlus provides a national framework for assigning reach addresses to water quality related entities, such as fish advisories locations. Reach addresses establish the locations of these entities relative to one another within the NHD surface water drainage network in a manner similar to street addresses. The assignment of reach addresses is accomplished through a process known as reach indexing. Fish consumption advisories and fish tissue sampling stations are reported to EPA by the states. Sampling stations are the locations where a state has collected fish tissue data for use in advisory determinations. Fish consumption advisory locations are coded onto NHDPlus flowline features to create point and linear events. Fish consumption advisory locations are also coded onto NHDPlus waterbody features to create area events. In addition to NHDPlus-reach indexed data, there may also be custom events (point, line, or area) that are not associated with NHDPlus. Although these Fish consumption advisories are not represented in NHDPlus, the data created for them are in an EPA standard format that is co

Reef Fishes at All Trophic Levels Respond Positively to Effective Marine Protected Areas

PubMed Central

Soler, German A.; Edgar, Graham J.; Thomson, Russell J.; Kininmonth, Stuart; Campbell, Stuart J.; Dawson, Terence P.; Barrett, Neville S.; Bernard, Anthony T. F.; Galván, David E.; Willis, Trevor J.; Alexander, Timothy J.; Stuart-Smith, Rick D.

2015-01-01

Marine Protected Areas (MPAs) offer a unique opportunity to test the assumption that fishing pressure affects some trophic groups more than others. Removal of larger predators through fishing is often suggested to have positive flow-on effects for some lower trophic groups, in which case protection from fishing should result in suppression of lower trophic groups as predator populations recover. We tested this by assessing differences in the trophic structure of reef fish communities associated with 79 MPAs and open-access sites worldwide, using a standardised quantitative dataset on reef fish community structure. The biomass of all major trophic groups (higher carnivores, benthic carnivores, planktivores and herbivores) was significantly greater (by 40% - 200%) in effective no-take MPAs relative to fished open-access areas. This effect was most pronounced for individuals in large size classes, but with no size class of any trophic group showing signs of depressed biomass in MPAs, as predicted from higher predator abundance. Thus, greater biomass in effective MPAs implies that exploitation on shallow rocky and coral reefs negatively affects biomass of all fish trophic groups and size classes. These direct effects of fishing on trophic structure appear stronger than any top down effects on lower trophic levels that would be imposed by intact predator populations. We propose that exploitation affects fish assemblages at all trophic levels, and that local ecosystem function is generally modified by fishing. PMID:26461104

Genomic comparison of virulent and non-virulent Streptococcus agalactiae in fish.

PubMed

Delannoy, C M J; Zadoks, R N; Crumlish, M; Rodgers, D; Lainson, F A; Ferguson, H W; Turnbull, J; Fontaine, M C

2016-01-01

Streptococcus agalactiae infections in fish are predominantly caused by beta-haemolytic strains of clonal complex (CC) 7, notably its namesake sequence type (ST) 7, or by non-haemolytic strains of CC552, including the globally distributed ST260. In contrast, CC23, including its namesake ST23, has been associated with a wide homeothermic and poikilothermic host range, but never with fish. The aim of this study was to determine whether ST23 is virulent in fish and to identify genomic markers of fish adaptation of S. agalactiae. Intraperitoneal challenge of Nile tilapia, Oreochromis niloticus (Linnaeus), showed that ST260 is lethal at doses down to 10(2) cfu per fish, whereas ST23 does not cause disease at 10(7) cfu per fish. Comparison of the genome sequence of ST260 and ST23 with those of strains derived from fish, cattle and humans revealed the presence of genomic elements that are unique to subpopulations of S. agalactiae that have the ability to infect fish (CC7 and CC552). These loci occurred in clusters exhibiting typical signatures of mobile genetic elements. PCR-based screening of a collection of isolates from multiple host species confirmed the association of selected genes with fish-derived strains. Several fish-associated genes encode proteins that potentially provide fitness in the aquatic environment. © 2014 John Wiley & Sons Ltd.

The future of fishes and fisheries in the changing oceans.

PubMed

Cheung, W W L

2018-03-01

This paper aims to highlight the risk of climate change on coupled marine human and natural systems and explore possible solutions to reduce such risk. Specifically, it explores some of the key responses of marine fish stocks and fisheries to climate change and their implications for human society. It highlights the importance of mitigating carbon emission and achieving the Paris Agreement in reducing climate risk on marine fish stocks and fisheries. Finally, it discusses potential opportunities for helping fisheries to reduce climate threats, through local adaptation. A research direction in fish biology and ecology is proposed that would help support the development of these potential solutions. © 2018 The Fisheries Society of the British Isles.

Nearshore temperature findings for the Colorado River in Grand Canyon, Arizona: possible implications for native fish

USGS Publications Warehouse

Ross, Robert P.; Vernieu, William S.

2013-01-01

Since the completion of Glen Canyon Dam, Arizona, in 1963, downstream water temperatures in the main channel of the Colorado River in Glen, Marble, and Grand Canyons are much colder in summer. This has negatively affected humpback chub (Gila cypha) and other native fish adapted to seasonally warm water, reducing main-channel spawning activity and impeding the growth and development of larval and juvenile fish. Recently published studies by U.S. Geological Survey scientists found that under certain conditions some isolated nearshore environments in Grand Canyon allow water to become separated from the main-channel current and to warm, providing refuge areas for the development of larval and juvenile fish.

Species identification and vitamin A level in lutjanid fish implicated in vitamin A poisoning.

PubMed

Hwang, Deng-Fwu; Lu, Chi-Huan; Lin, Wen-Feng

2010-04-01

One outbreak of food poisoning associated with ingestion of the liver of a large lutjanid fish was investigated in this study. The symptoms in three patients primarily included headache, nausea, vomiting, fever, vertigo, and visual disorientation and later included peeling of the skin. The species of fish implicated in this incident was Etelis carbunculus (family Lutjanidae) as determined by direct sequence analysis and PCR plus restriction fragment length polymorphism analysis for detection of the cytochrome b gene. Subsequently, several specimens of E. carbunculus of different body weights were collected, and the level of vitamin A in the muscle and liver was determined by high-performance liquid chromatography. The average level of vitamin A in E. carbunculus muscle was 12 +/- 2 IU/g and that in the liver was 9,844 +/- 7,812 IU/g. Regression models indicate that E. carbunculus with higher body weight and liver weight will have higher levels of vitamin A levels in the liver.

Expanding diversity of potential bacterial partners of the methanotrophic ANME archaea using Magneto-FISH

NASA Astrophysics Data System (ADS)

Trembath-Reichert, E.; Green-Saxena, A.; Steele, J. A.; Orphan, V. J.

2012-12-01

Sulfate-coupled anaerobic oxidation of methane (AOM) in marine sediments is the major sink for methane in the oceans. This process is believed to be catalyzed by as yet uncultured syntrophic consortia of ANME archaea (affiliated with the Methanosarcinales) and sulfate-reducing bacteria belonging to the Desulfosarcina/Desulfococcus and Desulfobulbaceae. These syntrophic consortia have been described from methane-rich habitats worldwide and appear to be most concentrated in areas of high methane flux, such as cold seeps along continental margins. The extent of the diversity and ecophysiological potential of these microbial associations is still poorly constrained. In an effort to better characterize the diversity of microorganisms forming associations with different clades of methanotrophic ANME archaea (ANME-1, ANME-2a/b/c, ANME-3) and link these organisms to potentially diagnostic metabolic genes (e.g. mcrA, dsrAB, aprA), we employed a unique culture-independent whole cell capture technique which combines Fluorescence In Situ Hybridization with immuno-magnetic cell capture (Magneto-FISH). We used Magneto-FISH for targeted enrichment of specific ANME groups and their associated bacteria directly from formalin- and ethanol-fixed methane seep sediment. The identity and metabolic gene diversity of captured microorganisms were then assessed by clone library construction and sequencing. Diversity recovered from Magneto-FISH experiments using general and clade-specific ANME targeted probes show both the expected selectivity of the FISH probes (i.e. predominately ANME-2c subclade captured with an ANME-2c probe and multiple ANME groups recovered with the general probe targeting most ANME). Follow up FISH experiments were conducted to confirm physical associations between ANME and unique bacterial members (deltaproteobacteria and other non-sulfate reducing groups) that were common to multiple Magneto-FISH capture experiments. Analyses of metabolic gene diversity for archaeal (mcrA) and sulfate-reducing (aprA and dsrAB) members of the consortia were generally consistent with the diversity observed by 16S rRNA from individual Magneto-FISH experiments. Together, this data indicates a role for the involvement of additional microbial groups in the AOM symbioses at methane seeps.

Elevated streamflows increase dam passage by juvenile coho salmon during winter: Implications of climate change in the Pacific Northwest

USGS Publications Warehouse

Kock, Tobias J.; Liedtke, Theresa L.; Rondorf, Dennis W.; Serl, John D.; Kohn, Mike; Bumbaco, Karin A.

2012-01-01

A 4-year evaluation was conducted to determine the proportion of juvenile coho salmon Oncorhynchus kisutch passing Cowlitz Falls Dam, on the Cowlitz River, Washington, during winter. River and reservoir populations of coho salmon parr were monitored using radiotelemetry to determine if streamflow increases resulted in increased downstream movement and dam passage. This was of interest because fish that pass downstream of Cowlitz Falls Dam become landlocked in Riffe Lake and are lost to the anadromous population. Higher proportions of reservoir-released fish (0.391-0.480) passed Cowlitz Falls Dam than did river-released fish (0.037-0.119). Event-time analyses demonstrated that streamflow increases were important predictors of dam passage rates during the study. The estimated effect of increasing streamflows on the risk of dam passage varied annually and ranged from 9% to 75% for every 28.3 m3/s increase in streamflow. These results have current management implications because they demonstrate the significance of dam passage by juvenile coho salmon during winter months when juvenile fish collection facilities are typically not operating. The results also have future management implications because climate change predictions suggest that peak streamflow timing for many watersheds in the Pacific Northwest will shift from late spring and early summer to winter. Increased occurrence of intense winter flood events is also expected. Our results demonstrate that juvenile coho salmon respond readily to streamflow increases and initiate downstream movements during winter months, which could result in increased passage at dams during these periods if climate change predictions are realized in the coming decades.

Persistent halogenated compounds in aquaculture environments of South China: implications for global consumers' health risk via fish consumption.

PubMed

Yu, Huan-Yun; Zhang, Bao-Zhong; Giesy, John P; Zeng, Eddy Y

2011-10-01

This study examined the potential sources of persistent halogenated compounds (PHCs), including organochlorine pesticides, mainly DDXs (sum of o,p'- and p,p'-DDT, -DDD, and -DDE and p,p'-DDMU) and polybrominated diphenyl ethers, to typical aquaculture environments of South China, determined the relative importance of gill diffusion and fish feeding for exposure of fish to these contaminants and assessed potential health risk for global consumers via consumption of fish from South China. Fish feed is generally a direct and important source of PHCs in both freshwater and seawater aquaculture. In addition, gill diffusion is the predominant uptake route for PHCs (except p,p'-DDMU, o,p'-DDD and -DDT) in farmed freshwater fish, whereas accumulation from the diet is the major route for farmed marine fish. Risks to health of global consumers via consumption of fish from South China are minimal. However, increased risk can be foreseen due to continuous use of brominated fire retardants and electronic waste importation to China. Copyright © 2011 Elsevier Ltd. All rights reserved.

Polyketide synthesis genes associated with toxin production in two species of Gambierdiscus (Dinophyceae).

PubMed

Kohli, Gurjeet S; John, Uwe; Figueroa, Rosa I; Rhodes, Lesley L; Harwood, D Tim; Groth, Marco; Bolch, Christopher J S; Murray, Shauna A

2015-05-28

Marine microbial protists, in particular, dinoflagellates, produce polyketide toxins with ecosystem-wide and human health impacts. Species of Gambierdiscus produce the polyether ladder compounds ciguatoxins and maitotoxins, which can lead to ciguatera fish poisoning, a serious human illness associated with reef fish consumption. Genes associated with the biosynthesis of polyether ladder compounds are yet to be elucidated, however, stable isotope feeding studies of such compounds consistently support their polyketide origin indicating that polyketide synthases are involved in their biosynthesis. Here, we report the toxicity, genome size, gene content and transcriptome of Gambierdiscus australes and G. belizeanus. G. australes produced maitotoxin-1 and maitotoxin-3, while G. belizeanus produced maitotoxin-3, for which cell extracts were toxic to mice by IP injection (LD50 = 3.8 mg kg(-1)). The gene catalogues comprised 83,353 and 84,870 unique contigs, with genome sizes of 32.5 ± 3.7 Gbp and 35 ± 0.88 Gbp, respectively, and are amongst the most comprehensive yet reported from a dinoflagellate. We found three hundred and six genes involved in polyketide biosynthesis, including one hundred and ninety-two ketoacyl synthase transcripts, which formed five unique phylogenetic clusters. Two clusters were unique to these maitotoxin-producing dinoflagellate species, suggesting that they may be associated with maitotoxin biosynthesis. This work represents a significant step forward in our understanding of the genetic basis of polyketide production in dinoflagellates, in particular, species responsible for ciguatera fish poisoning.

Ciguatera fish poisoning in an international ship crew in Saint John Canada: 2015.

PubMed

Muecke, C; Hamper, L; Skinner, A L; Osborne, C

2015-11-05

An international ship crew presented for medical care in Saint John, New Brunswick, following rapid onset of gastrointestinal and in some cases neurological and cardiac symptoms after a common fish meal. Ciguatera poisoning was identified as the cause of illness. This report describes the public health investigation and management of this incident, including collaboration between the implicated provincial and federal authorities.

Comparative analysis of Edwardsiella tarda isolates from fish in the eastern United States suggests the existence of two genetically distinct species, Edwardsiella tarda and Edwardsiella pseudotarda sp. nov

USDA-ARS?s Scientific Manuscript database

Edwardsiella tarda, a Gram-negative member of the family Enterobacteriaceae, is often implicated in significant losses in aquaculture facilities worldwide. Here, we assessed the intra-specific variability of a collection of E. tarda isolates from 4 different fish species in the eastern United State...

The Rise of Jaw Protrusion in Spiny-Rayed Fishes Closes the Gap on Elusive Prey.

PubMed

Bellwood, David R; Goatley, Christopher H R; Bellwood, Orpha; Delbarre, Daniel J; Friedman, Matt

2015-10-19

Jaw protrusion is one of the most important innovations in vertebrate feeding over the last 400 million years [1, 2]. Protrusion enables a fish to rapidly decrease the distance between itself and its prey [2, 3]. We assessed the evolution and functional implications of jaw protrusion in teleost fish assemblages from shallow coastal seas since the Cretaceous. By examining extant teleost fishes, we identified a robust morphological predictor of jaw protrusion that enabled us to predict the extent of jaw protrusion in fossil fishes. Our analyses revealed increases in both average and maximum jaw protrusion over the last 100 million years, with a progressive increase in the potential impact of fish predation on elusive prey. Over this period, the increase in jaw protrusion was initially driven by a taxonomic restructuring of fish assemblages, with an increase in the proportion of spiny-rayed fishes (Acanthomorpha), followed by an increase in the extent of protrusion within this clade. By increasing the ability of fishes to catch elusive prey [2, 4], jaw protrusion is likely to have fundamentally changed the nature of predator-prey interactions and may have contributed to the success of the spiny-rayed fishes, the dominant fish clade in modern oceans [5]. Copyright © 2015 Elsevier Ltd. All rights reserved.

'It's in the blood and you're not going to change it': fish harvesters' narrative accounts of injuries and disability.

PubMed

Murray, Michael

2007-01-01

Accidents are a common occurrence in the fishing industry. Despite this observation, there has been limited research on the factors contributing to this high rate of accidents and no research on the experience of disability among fish harvesters. This paper reports a narrative analysis of the accounts of fish harvesters who became disabled as a result of their work, and could no longer work in the industry. Four primary narrative structures were identified in their accounts: disability as devastation, disability as challenge, disability as phenomenon and disability as opportunity. These narratives represent different temporal orientations to the disability. The findings are discussed with reference to other narrative work on adjustment to illness and the implications for disability rehabilitation for fish harvesters and other workers.

Fatal methane and cyanide poisoning as a result of handling industrial fish: a case report and review of the literature

PubMed Central

Cherian, M; Richmond, I

2000-01-01

The potential health hazards of handling industrial fish are well documented. Wet fish in storage consume oxygen and produce poisonous gases as they spoil. In addition to oxygen depletion, various noxious agents have been demonstrated in association with spoilage including carbon dioxide, sulphur dioxide, and ammonia. A fatal case of methane and cyanide poisoning among a group of deep sea trawler men is described. Subsequent independent investigation as a result of this case led to the discovery of cyanides as a further potential noxious agent. This is thus the first case in which cyanide poisoning has been recognised as a potentially fatal complication of handling spoiled fish. The previous literature is reviewed and the implications of the current case are discussed. Key Words: industrial fish • methane • cyanide PMID:11064677

Elucidating fishing effects in a large-predator dominated system: The case of Darwin and Wolf Islands (Galápagos)

NASA Astrophysics Data System (ADS)

Ruiz, Diego J.; Banks, Stuart; Wolff, Matthias

2016-01-01

Fifty years of artisanal fishing history in Galápagos characterized by boom and bust of resources has changed the natural marine community structure close to fishing ports in the Galápagos Marine Reserve. Nonetheless, the remote Darwin and Wolf Islands are still in a "near natural state" harboring high species richness unique for the archipelago and high biomass. Marine life that aggregates to the pinnacles linked to the wider oceanic seascape makes them interesting and unique systems in terms of community structure and study of on-shore/offshore trophic interactions. Although > 200 km from local fishing ports the two islands also support an artisanal fishery targeting large demersal predators of high trophic levels. They are areas prioritized for conservation actions by Galápagos National Park, and local non-governmental organizations given their natural heritage importance, value to local fishers and revenue from dive tourism attracted by the promise of large marine predator aggregations such as sharks. Given that catch data upon which to base conservation recommendations is sparse it is difficult to accurately estimate present day fishing trends in Darwin and Wolf. We used a trophic steady-state model that connects benthic and pelagic communities to assess the potential effects of a change in fishing intensity in the two islands system. A predator-prey matrix was built using the Ecopath with Ecosim (EwE) software with total biomass estimated at 937 t km- 2. Large fish aggregations accounted for 19%, primary producers for 9.0% and non-fish (seabirds, marine mammals and sea turtles) for less than 0.1% of the total living biomass. The total system size in terms of overall flows was 16,652 t km- 2 year- 1, four times larger than a generic seamount model but smaller than that modeled for a Galápagos upwelling system based upon the western Bolivar Channel region. Consumption and respiration dominated the flows in the system (53.4 and 31.8% respectively). The Darwin and Wolf system shows a mature state, dominated by respiration, and top-down control via sharks and benthic predatory fish as the most important system compartments in terms of biomass. Model simulations suggest that heavy fishing pressure on top predators would greatly change the system's trophic structure. The nature of impacts depended on the types of gears simulated. Reduced natural predator densities through fishing exert strong direct and indirect influences on the system towards sea urchin-dominated benthos.

Origins of invasive piscivores determined from the strontium isotope ratio (87Sr/86Sr) of otoliths

USGS Publications Warehouse

Wolff, Brian A.; Johnson, Brett M.; Breton, Andre R.; Martinez, Patrick J.; Winkelman, Dana L.; Gillanders, Bronwyn

2012-01-01

We examined strontium isotope ratios (87Sr/86Sr) in fish otoliths to determine the origins of invasive piscivores in the Upper Colorado River Basin (UCRB, western USA). We examined 87Sr/86Sr from fishes in different reservoirs, as well as the temporal stability and interspecies variability of 87Sr/86Sr of fishes within reservoirs, determined if 87Sr/86Sr would be useful for "fingerprinting" reservoirs where invasive piscivores may have been escaping into riverine habitat of endangered fishes in the UCRB, and looked for evidence that such movement was occurring. Our results showed that in most cases 87Sr/86Sr was unique among reservoirs, overlapped among species in a given reservoir, and was temporally stable across years. We identified the likely reservoir of origin of river-caught fish in some cases, and we were also able to determine the year of possible escapement. The approach allowed us to precisely describe the 87Sr/86Sr fingerprint of reservoir fishes, trace likely origins of immigrant river fish, and exclude potential sources, enabling managers to focus control efforts more efficiently. Our results demonstrate the potential utility of 87Sr/86Sr as a site-specific and temporally stable marker for reservoir fish and its promise for tracking fish movements of invasive fishes in river-reservoir systems.

Automatic Realistic Real Time Stimulation/Recording in Weakly Electric Fish: Long Time Behavior Characterization in Freely Swimming Fish and Stimuli Discrimination

PubMed Central

Forlim, Caroline G.; Pinto, Reynaldo D.

2014-01-01

Weakly electric fish are unique model systems in neuroethology, that allow experimentalists to non-invasively, access, central nervous system generated spatio-temporal electric patterns of pulses with roles in at least 2 complex and incompletely understood abilities: electrocommunication and electrolocation. Pulse-type electric fish alter their inter pulse intervals (IPIs) according to different behavioral contexts as aggression, hiding and mating. Nevertheless, only a few behavioral studies comparing the influence of different stimuli IPIs in the fish electric response have been conducted. We developed an apparatus that allows real time automatic realistic stimulation and simultaneous recording of electric pulses in freely moving Gymnotus carapo for several days. We detected and recorded pulse timestamps independently of the fish’s position for days. A stimulus fish was mimicked by a dipole electrode that reproduced the voltage time series of real conspecific according to previously recorded timestamp sequences. We characterized fish behavior and the eletrocommunication in 2 conditions: stimulated by IPIs pre-recorded from other fish and random IPI ones. All stimuli pulses had the exact Gymontus carapo waveform. All fish presented a surprisingly long transient exploratory behavior (more than 8 h) when exposed to a new environment in the absence of electrical stimuli. Further, we also show that fish are able to discriminate between real and random stimuli distributions by changing several characteristics of their IPI distribution. PMID:24400122

Bioenergetics models to estimate numbers of larval lampreys consumed by smallmouth bass in Elk Creek, Oregon

USGS Publications Warehouse

Schultz, Luke; Heck, Michael; Kowalski, Brandon M; Eagles-Smith, Collin A.; Coates, Kelly C.; Dunham, Jason B.

2017-01-01

Nonnative fishes have been increasingly implicated in the decline of native fishes in the Pacific Northwest. Smallmouth Bass Micropterus dolomieu were introduced into the Umpqua River in southwest Oregon in the early 1960s. The spread of Smallmouth Bass throughout the basin coincided with a decline in counts of upstream-migrating Pacific Lampreys Entosphenus tridentatus. This suggested the potential for ecological interactions between Smallmouth Bass and Pacific Lampreys, as well as freshwater-resident Western Brook Lampreys Lampetra richardsoni. To evaluate the potential effects of Smallmouth Bass on lampreys, we sampled diets of Smallmouth Bass and used bioenergetics models to estimate consumption of larval lampreys in a segment of Elk Creek, a tributary to the lower Umpqua River. We captured 303 unique Smallmouth Bass (mean: 197 mm and 136 g) via angling in July and September. We combined information on Smallmouth Bass diet and energy density with other variables (temperature, body size, growth, prey energy density) in a bioenergetics model to estimate consumption of larval lampreys. Larval lampreys were found in 6.2% of diet samples, and model estimates indicated that the Smallmouth Bass we captured consumed 925 larval lampreys in this 2-month study period. When extrapolated to a population estimate of Smallmouth Bass in this segment, we estimated 1,911 larval lampreys were consumed between July and September. Although the precision of these estimates was low, this magnitude of consumption suggests that Smallmouth Bass may negatively affect larval lamprey populations.

A case of histamine fish poisoning in a young atopic woman.

PubMed

Wilson, Ben J; Musto, Richard J; Ghali, William A

2012-07-01

Histamine fish poisoning, also known as scombroid poisoning, is a histamine toxicity syndrome that results from eating specific types of spoiled fish. Although typically a benign syndrome, characterized by self-limited flushing, headache, and gastrointestinal symptoms, we describe a case unique in its severity and as a precipitant of an asthma exacerbation. A 25-year-old woman presented to the emergency department (ED) with one hour of tongue and face swelling, an erythematous pruritic rash, and dyspnea with wheezing after consuming a tuna sandwich. She developed abdominal pain, diarrhea and hypotension in the ED requiring admission to the hospital. A diagnosis of histamine fish poisoning was made and the patient was treated supportively and discharged within 24 hours, but was readmitted within 3 hours due to an asthma exacerbation. Her course was complicated by recurrent admissions for asthma exacerbations.

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

USGS Publications Warehouse

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

2012-01-01

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

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

PubMed

Lepak, Jesse M; Hooten, Mevin B; Johnson, Brett M

2012-10-01

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

Impacts of fishing and environmental factors driving changes on littoral fish assemblages in a subtropical oceanic island

NASA Astrophysics Data System (ADS)

Sangil, Carlos; Martín-García, Laura; Hernández, José Carlos; Concepción, Laura; Fernández, Raúl; Clemente, Sabrina

2013-08-01

The structure of demersal fish assemblages of commercial interest was studied at 51 sites on La Palma Island (Canary Islands, northeastern Atlantic). On this island, demersal fish populations are limited and independent from other islands. As deep water separates the islands and the shallow sublittoral platforms are not continuous, adult inter-island migrations are not possible except between the islands of Lanzarote and Fuerteventura. Otherwise, each island functions as a closed system, and the status of an island fish assemblage depends on local environmental conditions and activities performed in situ by the islanders. These circumstances provide a unique opportunity to test the intrainsular variability of fish assemblages. With this background, environmental parameters, fishing pressure and distance to the MPA were considered to identify the main factors explaining the spatial variation of fish assemblages off La Palma Island. Twenty-six fish species were recorded, but 60% of the total fish biomass was represented by only five species (Sparisoma cretense, Pomadasys incisus, Canthidermis sufflamen, Diplodus cervinus cervinus and Bodianus scrofa). However, the structure of assemblages was heterogeneous in response to different variables and showed substantial spatial variation. The assemblages were strongly modified by the presence of upright seaweed cover, fishing activities, and certain environmental variables. Differences were more pronounced in species that occupied the higher trophic levels. The most disturbed assemblages were those located in areas with lower upright seaweed cover and with higher fishing pressure, whereas the best-preserved assemblages corresponded to sites with controlled fishing activities, located within the MPA.

Complex dynamics at the interface between wild and domestic viruses of finfish

USGS Publications Warehouse

Kurath, G.; Winton, J.

2011-01-01

Viral traffic occurs readily between wild and domesticated stocks of finfish because aquatic environments have greater connectivity than their terrestrial counterparts and because the global expansion and dynamic nature of intensive aquaculture provide multiple pathways of transmission and unique drivers of virus adaptation. Supported by examples from the literature, we provide reasons why viruses move from wild fish reservoirs to infect domestic fish in aquaculture more readily than 'domestic' viruses move across the interface to infect wild stocks. We also hypothesize that 'wild' viruses moving across the interface to domestic populations of finfish are more frequently associated with disease outbreaks and host switches compared to domestic viruses that cross the interface to infect wild fish.

Signal Cloaking by Electric Fish

PubMed Central

STODDARD, PHILIP K.; MARKHAM, MICHAEL R.

2010-01-01

Electric fish produce weak electric fields to image their world in darkness and to communicate with potential mates and rivals. Eavesdropping by electroreceptive predators exerts selective pressure on electric fish to shift their signals into less-detectable high-frequency spectral ranges. Hypopomid electric fish evolved a signal-cloaking strategy that reduces their detectability by predators in the lab (and thus presumably their risk of predation in the field). These fish produce broad-frequency electric fields close to the body, but the heterogeneous local fields merge over space to cancel the low-frequency spectrum at a distance. Mature males dynamically regulate this cloaking mechanism to enhance or suppress low-frequency energy. The mechanism underlying electric-field cloaking involves electrogenic cells that produce two independent action potentials. In a unique twist, these cells orient sodium and potassium currents in the same direction, potentially boosting their capabilities for current generation. Exploration of such evolutionary inventions could aid the design of biogenerators to power implantable medical devices, an ambition that would benefit from the complete genome sequence of a gymnotiform fish. PMID:20209064

Critical role of seasonal tributaries for native fish and aquatic biota in the Sacramento River

NASA Astrophysics Data System (ADS)

Marchetti, M.

2016-12-01

We examined the ecology of seasonal tributaries in California in terms of native fishes and aquatic macroinvertebrates. This talk summarizes data from five individual studies. Studying juvenile Chinook growth using otolith microstructure we find that fish grow faster and larger in seasonal tributaries. In a four-year study on the abundance of native fish larvae in tributaries of the Sacramento River we find certain tributaries produce an order of magnitude more native fish larvae than nearby permanent streams. In a study comparing the distribution and abundance of aquatic macroinvertebrates in a seasonal tributary with a permanent stream we find the seasonal tributary contains unique taxa, higher drift densities and ecologically distinct communities. In a cross-watershed comparison of larval fish drift we find that a seasonal tributary produces more larvae than all other streams/rivers we examined. In a comparison of juvenile Chinook growth morphology between seasonal and permanent streams using geometric morphometrics we find that salmon show phenotypic plasticity and their growth is characteristically different in seasonal tributaries. Taken together, this body of work highlights the critical ecological importance of this habitat.

Full-Sibs in Cohorts of Newly Settled Coral Reef Fishes

PubMed Central

Bernardi, Giacomo; Beldade, Ricardo; Holbrook, Sally J.; Schmitt, Russell J.

2012-01-01

Reef fishes exhibit a bipartite life cycle where a benthic adult stage is preceded by a pelagic dispersal phase during which larvae are presumed to be mixed and transported by oceanic currents. Genetic analyses based on twelve microsatellite loci of 181 three-spot dascyllus (Dascyllus trimaculatus) that settled concurrently on a small reef in French Polynesia revealed 11 groups of siblings (1 full sibs and 10 half-sibs). This is the first evidence that fish siblings can journey together throughout their entire planktonic dispersal phase (nearly a month long for three-spot dascyllus). Our findings have critical implications for the dynamics and genetic structure of fish populations, as well as for the design of marine protected areas and management of fisheries. PMID:23028700

Role of self-caught fish in total fish consumption rates for recreational fishermen: Average consumption for some species exceeds allowable intake.

PubMed

Burger, Joanna

2013-01-01

Studies of fish consumption focus on recreational or subsistence fishing, on awareness and adherence to advisories, consumption patterns, and contaminants in fish. Yet the general public obtains their fish from commercial sources. In this paper I examine fish consumption patterns of recreational fishermen in New Jersey to determine: 1) consumption rates for self-caught fish and for other fish, 2) meals consumed per year, 3) average meal size, and average daily intake of mercury, and 4) variations in these parameters for commonly-consumed fish, and different methods of computing intake. Over 300 people were interviewed at fishing sites and fishing clubs along the New Jersey shore. Consumption patterns of anglers varied by species of fish. From 2 to 90 % of the anglers ate the different fish species, and between 9 and 75 % gave fish away to family or friends. Self-caught fish made up 7 to 92 % of fish diets. On average, self-caught fish were eaten for only 2 to 6 months of the year, whereas other fish (commercial or restaurant) were eaten up to 10 months a year. Anglers consumed from 5 to 36 meals of different fish a year, which resulted in intake of mercury ranging from 0.01 to 0.22 ug/kg/day. Average intake of Mako shark, swordfish, and tuna (sushi, canned tuna, self-caught tuna) exceeded the U.S. Environmental Protection Agency's oral, chronic reference dose for mercury of 0.1 ug/kg/day. However, computing intake using consumption for the highest month results in average mercury intake exceeding the reference dose for striped bass and bluefish as well. These data, and the variability in consumption patterns, have implications for risk assessors, risk managers, and health professionals.

Role of self-caught fish in total fish consumption rates for recreational fishermen: Average consumption for some species exceeds allowable intake

PubMed Central

Burger, Joanna

2013-01-01

Studies of fish consumption focus on recreational or subsistence fishing, on awareness and adherence to advisories, consumption patterns, and contaminants in fish. Yet the general public obtains their fish from commercial sources. In this paper I examine fish consumption patterns of recreational fishermen in New Jersey to determine: 1) consumption rates for self-caught fish and for other fish, 2) meals consumed per year, 3) average meal size, and average daily intake of mercury, and 4) variations in these parameters for commonly-consumed fish, and different methods of computing intake. Over 300 people were interviewed at fishing sites and fishing clubs along the New Jersey shore. Consumption patterns of anglers varied by species of fish. From 2 to 90 % of the anglers ate the different fish species, and between 9 and 75 % gave fish away to family or friends. Self-caught fish made up 7 to 92 % of fish diets. On average, self-caught fish were eaten for only 2 to 6 months of the year, whereas other fish (commercial or restaurant) were eaten up to 10 months a year. Anglers consumed from 5 to 36 meals of different fish a year, which resulted in intake of mercury ranging from 0.01 to 0.22 ug/kg/day. Average intake of Mako shark, swordfish, and tuna (sushi, canned tuna, self-caught tuna) exceeded the U.S. Environmental Protection Agency’s oral, chronic reference dose for mercury of 0.1 ug/kg/day. However, computing intake using consumption for the highest month results in average mercury intake exceeding the reference dose for striped bass and bluefish as well. These data, and the variability in consumption patterns, have implications for risk assessors, risk managers, and health professionals. PMID:23914136

Using the internet to understand angler behavior in the information age

USGS Publications Warehouse

Martin, Dustin R.; Pracheil, Brenda M.; DeBoer, Jason A.; Wilde, Gene R.; Pope, Kevin L.

2012-01-01

Declining participation in recreational angling is of great concern to fishery managers because fishing license sales are an important revenue source for protection of aquatic resources. This decline is frequently attributed, in part, to increased societal reliance on electronics. Internet use by anglers is increasing and fishery managers may use the Internet as a unique means to increase angler participation. We examined Internet search behavior using Google Insights for Search, a free online tool that summarizes Google searches from 2004 to 2011 to determine (1) trends in Internet search volume for general fishing related terms and (2) the relative usefulness of terms related to angler recruitment programs across the United States. Though search volume declined for general fishing terms (e.g., fishing, fishing guide), search volume increased for social media and recruitment terms (e.g., fishing forum, family fishing) over the 7-year period. We encourage coordinators of recruitment programs to capitalize on anglers’ Internet usage by considering Internet search patterns when creating web-based information. Careful selection of terms used in web-based information to match those currently searched by potential anglers may help to direct traffic to state agency websites that support recruitment efforts.

Water quality and fish dynamics in forested wetlands associated with an oxbow lake

USGS Publications Warehouse

Andrews, Caroline S.; Miranda, Leandro E.; Kroger, Robert

2015-01-01

Forested wetlands represent some of the most distinct environments in the Lower Mississippi Alluvial Valley. Depending on season, water in forested wetlands can be warm, stagnant, and oxygen-depleted, yet may support high fish diversity. Fish assemblages in forested wetlands are not well studied because of difficulties in sampling heavily structured environments. During the April–July period, we surveyed and compared the water quality and assemblages of small fish in a margin wetland (forested fringe along a lake shore), contiguous wetland (forested wetland adjacent to a lake), and the open water of an oxbow lake. Dissolved-oxygen levels measured hourly 0.5 m below the surface were higher in the open water than in either of the forested wetlands. Despite reduced water quality, fish-species richness and catch rates estimated with light traps were greater in the forested wetlands than in the open water. The forested wetlands supported large numbers of fish and unique fish assemblages that included some rare species, likely because of their structural complexity. Programs developed to refine agricultural practices, preserve riparian zones, and restore lakes should include guidance to protect and reestablish forested wetlands.

Structure of Mesophotic Reef Fish Assemblages in the Northwestern Hawaiian Islands

PubMed Central

Kosaki, Randall K.; Wagner, Daniel; Kane, Corinne

2016-01-01

Mesophotic coral ecosystems (MCEs) support diverse communities of marine organisms with changes in community structure occurring along a depth gradient. In recent years, MCEs have gained attention due to their depths that provide protection from natural and anthropogenic stressors and their relative stability over evolutionary time periods, yet ecological structures of fish assemblages in MCEs remain largely un-documented. Here, we investigated composition and trophic structure of reef fish assemblages in the Northwestern Hawaiian Islands (NWHI) along a depth gradient from 1 to 67 m. The structure of reef fish assemblages as a whole showed a clear gradient from shallow to mesophotic depths. Fish assemblages at mesophotic depths had higher total densities than those in shallower waters, and were characterized by relatively high densities of planktivores and invertivores and relatively low densities of herbivores. Fishes that typified assemblages at mesophotic depths included six species that are endemic to the Hawaiian Islands. The present study showed that mesophotic reefs in the NWHI support unique assemblages of fish that are characterized by high endemism and relatively high densities of planktivores. Our findings underscore the ecological importance of these undersurveyed ecosystems and warrant further studies of MCEs. PMID:27383614

Unexpected high vulnerability of functions in wilderness areas: evidence from coral reef fishes.

PubMed

D'agata, Stéphanie; Vigliola, Laurent; Graham, Nicholas A J; Wantiez, Laurent; Parravicini, Valeriano; Villéger, Sébastien; Mou-Tham, Gerard; Frolla, Philippe; Friedlander, Alan M; Kulbicki, Michel; Mouillot, David

2016-12-14

High species richness is thought to support the delivery of multiple ecosystem functions and services under changing environments. Yet, some species might perform unique functional roles while others are redundant. Thus, the benefits of high species richness in maintaining ecosystem functioning are uncertain if functions have little redundancy, potentially leading to high vulnerability of functions. We studied the natural propensity of assemblages to be functionally buffered against loss prior to fishing activities, using functional trait combinations, in coral reef fish assemblages across unfished wilderness areas of the Indo-Pacific: Chagos Archipelago, New Caledonia and French Polynesia. Fish functional diversity in these wilderness areas is highly vulnerable to fishing, explained by species- and abundance-based redundancy packed into a small combination of traits, leaving most other trait combinations (60%) sensitive to fishing, with no redundancy. Functional vulnerability peaks for mobile and sedentary top predators, and large species in general. Functional vulnerability decreases for certain functional entities in New Caledonia, where overall functional redundancy was higher. Uncovering these baseline patterns of functional vulnerability can offer early warning signals of the damaging effects from fishing, and may serve as baselines to guide precautionary and even proactive conservation actions. © 2016 The Author(s).

Unexpected high vulnerability of functions in wilderness areas: evidence from coral reef fishes

PubMed Central

Vigliola, Laurent; Graham, Nicholas A. J.; Wantiez, Laurent; Parravicini, Valeriano; Villéger, Sébastien; Mou-Tham, Gerard; Frolla, Philippe; Friedlander, Alan M.; Kulbicki, Michel; Mouillot, David

2016-01-01

High species richness is thought to support the delivery of multiple ecosystem functions and services under changing environments. Yet, some species might perform unique functional roles while others are redundant. Thus, the benefits of high species richness in maintaining ecosystem functioning are uncertain if functions have little redundancy, potentially leading to high vulnerability of functions. We studied the natural propensity of assemblages to be functionally buffered against loss prior to fishing activities, using functional trait combinations, in coral reef fish assemblages across unfished wilderness areas of the Indo-Pacific: Chagos Archipelago, New Caledonia and French Polynesia. Fish functional diversity in these wilderness areas is highly vulnerable to fishing, explained by species- and abundance-based redundancy packed into a small combination of traits, leaving most other trait combinations (60%) sensitive to fishing, with no redundancy. Functional vulnerability peaks for mobile and sedentary top predators, and large species in general. Functional vulnerability decreases for certain functional entities in New Caledonia, where overall functional redundancy was higher. Uncovering these baseline patterns of functional vulnerability can offer early warning signals of the damaging effects from fishing, and may serve as baselines to guide precautionary and even proactive conservation actions. PMID:27928042

Recent advances in rice genome and chromosome structure research by fluorescence in situ hybridization (FISH).

PubMed

Ohmido, Nobuko; Fukui, Kiichi; Kinoshita, Toshiro

2010-01-01

Fluorescence in situ hybridization (FISH) is an effective method for the physical mapping of genes and repetitive DNA sequences on chromosomes. Physical mapping of unique nucleotide sequences on specific rice chromosome regions was performed using a combination of chromosome identification and highly sensitive FISH. Increases in the detection sensitivity of smaller DNA sequences and improvements in spatial resolution have ushered in a new phase in FISH technology. Thus, it is now possible to perform in situ hybridization on somatic chromosomes, pachytene chromosomes, and even on extended DNA fibers (EDFs). Pachytene-FISH allows the integration of genetic linkage maps and quantitative chromosome maps. Visualization methods using FISH can reveal the spatial organization of the centromere, heterochromatin/euchromatin, and the terminal structures of rice chromosomes. Furthermore, EDF-FISH and the DNA combing technique can resolve a spatial distance of 1 kb between adjacent DNA sequences, and the detection of even a 300-bp target is now feasible. The copy numbers of various repetitive sequences and the sizes of various DNA molecules were quantitatively measured using the molecular combing technique. This review describes the significance of these advances in molecular cytology in rice and discusses future applications in plant studies using visualization techniques.

Long-term change in benthopelagic fish abundance in the abyssal northeast Pacific Ocean.

PubMed

Bailey, D M; Ruhl, H A; Smith, K L

2006-03-01

Food web structure, particularly the relative importance of bottom-up and top-down control of animal abundances, is poorly known for the Earth's largest habitats: the abyssal plains. A unique 15-yr time series of climate, productivity, particulate flux, and abundance of primary consumers (primarily echinoderms) and secondary consumers (fish) was examined to elucidate the response of trophic levels to temporal variation in one another. Towed camera sled deployments in the abyssal northeast Pacific (4100 m water depth) showed that annual mean numbers of the dominant fish genus (Coryphaenoides spp.) more than doubled over the period 1989-2004. Coryphaenoides spp. abundance was significantly correlated with total abundance of mobile epibenthic megafauna (echinoderms), with changes in fish abundance lagging behind changes in the echinoderms. Direct correlations between surface climate and fish abundances, and particulate organic carbon (POC) flux and fish abundances, were insignificant, which may be related to the varied response of the potential prey taxa to climate and POC flux. This study provides a rare opportunity to study the long-term dynamics of an unexploited marine fish population and suggests a dominant role for bottom-up control in this system.

Ecological mechanisms underlying the sustainability of the agricultural heritage rice-fish coculture system.

PubMed

Xie, Jian; Hu, Liangliang; Tang, Jianjun; Wu, Xue; Li, Nana; Yuan, Yongge; Yang, Haishui; Zhang, Jiaen; Luo, Shiming; Chen, Xin

2011-12-13

For centuries, traditional agricultural systems have contributed to food and livelihood security throughout the world. Recognizing the ecological legacy in the traditional agricultural systems may help us develop novel sustainable agriculture. We examine how rice-fish coculture (RF), which has been designated a "globally important agricultural heritage system," has been maintained for over 1,200 y in south China. A field survey demonstrated that although rice yield and rice-yield stability are similar in RF and rice monoculture (RM), RF requires 68% less pesticide and 24% less chemical fertilizer than RM. A field experiment confirmed this result. We documented that a mutually beneficial relationship between rice and fish develops in RF: Fish reduce rice pests and rice favors fish by moderating the water environment. This positive relationship between rice and fish reduces the need for pesticides in RF. Our results also indicate a complementary use of nitrogen (N) between rice and fish in RF, resulting in low N fertilizer application and low N release into the environment. These findings provide unique insights into how positive interactions and complementary use of resource between species generate emergent ecosystem properties and how modern agricultural systems might be improved by exploiting synergies between species.

Multi-camera volumetric PIV for the study of jumping fish

NASA Astrophysics Data System (ADS)

Mendelson, Leah; Techet, Alexandra H.

2018-01-01

Archer fish accurately jump multiple body lengths for aerial prey from directly below the free surface. Multiple fins provide combinations of propulsion and stabilization, enabling prey capture success. Volumetric flow field measurements are crucial to characterizing multi-propulsor interactions during this highly three-dimensional maneuver; however, the fish's behavior also drives unique experimental constraints. Measurements must be obtained in close proximity to the water's surface and in regions of the flow field which are partially-occluded by the fish body. Aerial jump trajectories must also be known to assess performance. This article describes experiment setup and processing modifications to the three-dimensional synthetic aperture particle image velocimetry (SAPIV) technique to address these challenges and facilitate experimental measurements on live jumping fish. The performance of traditional SAPIV algorithms in partially-occluded regions is characterized, and an improved non-iterative reconstruction routine for SAPIV around bodies is introduced. This reconstruction procedure is combined with three-dimensional imaging on both sides of the free surface to reveal the fish's three-dimensional wake, including a series of propulsive vortex rings generated by the tail. In addition, wake measurements from the anal and dorsal fins indicate their stabilizing and thrust-producing contributions as the archer fish jumps.

Demersal fish distribution and habitat use within and near Baltimore and Norfolk Canyons, U.S. Middle Atlantic Slope

USGS Publications Warehouse

Ross, Steve W.; Rhode, Mike; Quattrini, Andrea M.

2015-01-01

Numerous submarine canyons along the United States middle Atlantic continental margin support enhanced productivity, diverse and unique habitats, active fisheries, and are vulnerable to various anthropogenic disturbances. During two cruises (15 Aug–2 Oct 2012 and 30 Apr–27 May 2013), Baltimore and Norfolk canyons and nearby areas (including two cold seeps) were intensively surveyed to determine demersal fish distributions and habitat associations. Overall, 34 ROV dives (234–1612 m) resulted in 295 h of bottom video observations and numerous collections. These data were supplemented by 40, 30-min bottom trawl samples. Fish observations were assigned to five general habitat designations: 1) sand-mud (flat), 2) sloping sand-mud with burrows, 3) low profile gravel, rock, boulder, 4) high profile, canyon walls, rocks or ridges, and 5) seep-mixed hard and soft substrata, the later subdivided into seven habitats based on amounts of dead mussel and rock cover. The influence of corals, sponges and live mussels (seeps only) on fish distributions was also investigated. Both canyon areas supported abundant and diverse fish communities and exhibited a wide range of habitats, including extensive areas of deep-sea corals and sponges and two nearby methane seeps (380–430 m, 1455–1610 m). All methods combined yielded a total of 123 species of fishes, 12 of which are either new records for this region or have new range data. Depth was a major factor that separated the fish faunas into two zones with a boundary around 1400 m. Fishes defining the deeper zone included Lycodes sp.,Dicrolene introniger, Gaidropsaurus ensis, Hydrolagus affinis, Antimora rostrata, andAldrovandia sp. Fishes in the deep zone did not exhibit strong habitat affinities, despite the presence of a quite rugged, extensive methane seep. We propose that habitat specificity decreases with increasing depth. Fishes in the shallower zone, characterized by Laemonema sp., Phycis chesteri, Nezumia bairdii, Brosme brosme, and Helicolenus dactylopterus, exhibited a variety of habitat use patterns. In general, fish assemblages in the soft substrata areas (dominated by P. chesteri, N. bairdii, Glyptocephalus cynoglossus, Lophius americanus, Merluccius albidus) were different from those in more complex habitats (dominated by Laemonema spp., Hoplostethus spp., B. brosme,Benthocometes robustus, L. americanus, Dysommina rugosa). Although, when present, the dense coral and sponge cover did not statistically affect general fish assemblage patterns in hard bottom habitats, these sessile organisms markedly increased habitat complexity, and some fish species exhibited close association with them. Fish species compositions in the two canyons were not substantially different from the surrounding slopes. However, the diversity of habitats within both the canyons and seeps exerted an important influence on assemblage structure. At least for some species (e.g., B. brosme) canyon and seep environments may be a refuge from intensive bottom fishing activities. We frequently observed evidence of commercial and recreational fishing activity (lost gear on bottom and fishing boats in the area) throughout the canyons and some resulting habitat damage. Conservation measures for the unique and more vulnerable areas (seep and coral habitats) have recently been approved.

Do scientists and fishermen collect the same size fish? Possible implications for exposure assessment.

PubMed

Burger, Joanna; Gochfeld, Michael; Burke, Sean; Jeitner, Christian W; Jewett, Stephen; Snigaroff, Daniel; Snigaroff, Ronald; Stamm, Tim; Harper, Shawn; Hoberg, Max; Chenelot, Heloise; Patrick, Robert; Volz, Conrad D; Weston, James

2006-05-01

Recreational and subsistence fishing plays a major role in the lives of many people, although most Americans obtain their fish from supermarkets or other commercial sources. Fish consumption has generally increased in recent years, largely because of the nutritional benefits. Recent concerns about contaminants in fish have prompted federal and state agencies to analyze fish (especially freshwater fish targeted by recreational anglers) for contaminants, such as mercury and polychlorinated biphenyls (PCBs), and to issue fish consumption advisories to help reduce the public health risks, where warranted. Scientists engaged in environmental sampling collect fish by a variety of means, and analyze the contaminants in those fish. Risk assessors use these levels as the basis for their advisories. Two assumptions of this methodology are that scientists collect the same size (and types) of fish that fishermen catch, and that, for some contaminants (such as methylmercury and PCBs), levels increase with the size and age of the fish. While many studies demonstrate a positive relationship between size and mercury levels in a wide range of different species of fish, the assumption that scientists collect the same size fish as fishermen has not been examined. The assumption that scientists collect the same size fish as those caught (and eaten) by recreationalists or subsistence fishermen is extremely important because contaminant levels are different in different size fish. In this article, we test the null hypothesis that there are no differences in the sizes of fish collected by Aleut fishermen, scientists (including divers), and commercial trawlers in the Bering Sea from Adak to Kiska. Aleut fishermen caught fish using rod-and-reel (fishing rods, hook, and fresh bait) from boats, as they would in their Aleutian villages. The scientists collected fish using rod-and-reel, as well as by scuba divers using spears up to 90 ft depths. A fisheries biologist collected fish from a research/commercial trawler operated under charter to the National Oceanographic and Atmospheric Administration (NOAA). The fish selected for sampling, including those caught commercially in the Bering Sea, represented different trophic levels, and are species regularly caught by Aleuts while fishing near their villages. Not all fish were caught by all three groups. There were no significant differences in length and weight for five species of fish caught by Aleuts, scientists, and fisheries trawls, and for an additional 3 species caught only by the Aleut and scientist teams. There were small, but significant, differences in the sizes of rock greenling (Hexagrammos lagocephalus) and red Irish lord (Hemilepidotus hemilepidotus) caught by the scientist and Aleut fishermen. No scientists caught rock greenling using poles; those speared by the divers were significantly smaller than those caught by the Aleuts. Further, there were no differences in the percent of males in the samples as a function of fishing method or type of fishermen, except for rockfish and red Irish lord. These data suggest that if scientists collect fish in the same manner as subsistence fishermen (in this case, using fishing rods from boats), they can collect the same-sized fish. The implications for exposure and risk assessment are that scientists should either engage subsistence and recreational fishermen to collect fish for analysis, or mimic their fishing methods to ensure that the fish collected are similar in size and weight to those being caught and consumed by these groups. Further, total length, standard length, and weight were highly correlated for all species of fish, suggesting that risk assessors could rely on recreational and commercial fishermen to measure total lengths for the purpose of correlating mercury levels with known size/mercury level relationships. Our data generally demonstrate that the scientists and trawlers can collect the same size fish as those caught by Aleuts, making contaminant analysis, and subsequent contaminant analysis, representative of the risks to fish consumers.

Self-reporting bias in Chinook salmon sport fisheries in Idaho: implications for roving creel surveys

USGS Publications Warehouse

McCormick, Joshua L.; Quist, Michael C.; Schill, Daniel J.

2013-01-01

Self-reporting bias in sport fisheries of Chinook Salmon Oncorhynchus tshawytscha in Idaho was quantified by comparing observed and angler-reported data. A total of 164 observed anglers fished for 541 h and caught 74 Chinook Salmon. Fifty-eight fish were harvested and 16 were released. Anglers reported fishing for 604 h, an overestimate of 63 h. Anglers reported catching 66 fish; four less harvested and four less released fish were reported than observed. A Monte Carlo simulation revealed that when angler-reported data were used, total catch was underestimated by 14–15 fish (19–20%) using the ratio-of-means estimator to calculate mean catch rate. Negative bias was reduced to six fish (8%) when the means-of-ratio estimator was used. Multiple linear regression models to predict reporting bias in time fished had poor predictive value. However, actual time fished and a categorical covariate indicating whether the angler fished continuously during their fishing trip were two variables that were present in all of the top a priori models evaluated. Underreporting of catch and overreporting of time fished by anglers present challenges when managing Chinook Salmon sport fisheries. However, confidence intervals were near target levels and using more liberal definitions of angling when estimating effort in creel surveys may decrease sensitivity to bias in angler-reported data.

Effectiveness of seining after electrofishing to characterize stream fish communities

USGS Publications Warehouse

Meador, Michael R.

2012-01-01

The richness and composition of species collected uniquely to electrofishing and subsequent seining efforts were examined at 271 stream sites across the USA by using wadeable electrofishing methods (backpack or barge electrofishing) or boat electrofishing followed by seining. Seining after wadeable electrofishing resulted in the collection of new species at 42% of sites, whereas seining after boat electrofishing resulted in the collection of new species at 87% of sites. Mean percentage of total observed fish species richness that was collected uniquely by seining was 6% (representing one new species, on average) after wadeable electrofishing compared with 18% (four new species, on average) after boat electrofishing. Shannon–Wiener diversity index values were not significantly different between data from combined sampling (electrofishing and seining) and data from wadeable electrofishing (P = 0.490) but were significantly different between boat electrofishing and combined sampling (P = 0.004). Seining efforts after boat electrofishing can provide critical information that allows for a more complete characterization of the fish community. For sampling in wadeable streams, decisions regarding the use of seines should consider the effectiveness of electrofishing at a given site and the use of seines as an alternative primary sampling gear rather than as a supplement to electrofishing.

Cooperative Fish and Wildlife Research Units - A model partnership program

USGS Publications Warehouse

Dennerline, Donald E.; Childs, Dawn E.

2017-04-20

The U.S. Geological Survey (USGS) Cooperative Fish and Wildlife Research Units (CRU) program is a unique model of cooperative partnership among the USGS, other U.S. Department of the Interior and Federal agencies, universities, State fish and wildlife agencies, and the Wildlife Management Institute. These partnerships are maintained as one of the USGS’s strongest links to Federal and State land and natural resource management agencies.Established in 1935 to meet the need for trained professionals in the growing field of wildlife management, the program currently consists of 40 Cooperative Fish and Wildlife Research Units located on university campuses in 38 States and supports 119 research scientist positions when fully funded. The threefold mission of the CRU program is to (1) conduct scientific research for the management of fish, wildlife, and other natural resources; (2) provide technical assistance to natural resource managers in the application of scientific information to natural resource policy and management; and (3) train future natural resource professionals.

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

PubMed

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

2016-07-01

The remarkable fish diversity in the Caribbean rivers of north-western South America evolved under the influences of the dramatic environmental changes of neogene northern South America, including the Quechua Orogeny and Pleistocene climate oscillations. Although this region is not the richest in South America, endemism is very high. Fish assemblage structure is unique to each of the four aquatic systems identified (rivers, streams, floodplain lakes and reservoirs) and community dynamics are highly synchronized with the mono-modal or bi-modal flooding pulse of the rainy seasons. The highly seasonal multispecies fishery is based on migratory species. Freshwater fish conservation is a challenge for Colombian environmental institutions because the Caribbean trans-Andean basins are the focus of the economic development of Colombian society, so management measures must be directed to protect aquatic habitat and their connectivity. These two management strategies are the only way for helping fish species conservation and sustainable fisheries. © 2016 The Fisheries Society of the British Isles.

Application of truss analysis for the quantification of changes in fish condition

USGS Publications Warehouse

Fitzgerald, Dean G.; Nanson, Jeffrey W.; Todd, Thomas N.; Davis, Bruce M.

2002-01-01

Conservation of skeletal structure and unique body ratios in fishes facilitated the development of truss analysis as a taxonomic tool to separate physically-similar species. The methodology is predicated on the measurement of across-body distances from a sequential series of connected polygons. Changes in body shape or condition among members of the same species can be quantified with the same technique, and we conducted a feeding experiment using yellow perch (Perca flavescens) to examine the utility of this approach. Ration size was used as a surrogate for fish condition, with fish receiving either a high (3.0% body wt/d) or a low ration (0.5%). Sequentially over our 11-week experiment, replicate ration groups of fish were removed and photographed while control fish were repeatedly weighed and measured. Standard indices of condition (total lipids, weight-length ratios, Fulton's condition) were compared to truss measurements determined from digitized pictures of fish. Condition indices showed similarity between rations while truss measures from the caudal region were important for quantifying changing body shape. These findings identify truss analysis as having use beyond traditional applications. It can potentially be used as a cheap, accurate, and precise descriptor of fish condition in the lab as shown here, and we hypothesize that it would be applicable in field studies.

Detection of eyeshine by flashlight fishes of the family Anomalopidae.

PubMed

Howland, H C; Murphy, C J; McCosker, J E

1992-04-01

Flashlight fishes of the family Anomalopidae live in clear tropical waters and are nocturnally active. They have luminescent organs located just below the pupils of their eyes. The relation of the luminescent organ to the pupil of the anomalopid eye is similar to that of the illumination and pupil system of the ophthalmoscope and identical to that of some photoretinoscopes. Indeed, one species of flashlight fish, Anomalops katoptron, actually moves its luminous organ away from its pupils in the process of occluding its light organ, making a retinoscopic-like movement. By photographing the eyeshine of a number of fishes with a photoretinoscope and by analyzing the optics of light organs of fish of the family Anomalopidae as well as the optics of reflecting eyes, we show under what light conditions and ranges flashlight fishes may reasonably be able to detect eyeshine from other fishes in the environment. Further, we suggest that flashlight fishes may be able to communicate with each other by altering the accommodation of their eyes. In such a communication system, the sender radiates no energy and communicates only with the interrogating receiver of the information. To our knowledge, this utilization of eyeshine, both for detection and for communication, is unique in the animal kingdom.

Physiologic implications of inter-hormonal interference in fish: lessons from the interaction of adrenaline with cortisol and thyroid hormones in climbing perch (Anabas testudineus Bloch).

PubMed

George, Nimta; Peter, Valsa S; Peter, M C Subhash

2013-01-15

Adrenaline and cortisol, the major stress hormones, are known for its direct control on stress response in fish. Likewise, as an important stress modifier hormone, thyroid hormone has also been implicated in stress response of fish. We tested whether the hypothesis on the phenomenon of inter-hormonal interference, a process that explains the hormonal interactions, operates in fish particularly between adrenaline, cortisol and thyroid hormones. To achieve this goal, indices of acid-base, osmotic and metabolic regulations were quantified after adrenaline challenge in propranolol pre-treated air-breathing fish (Anabas testudineus). Short-term adrenaline (10 ng g(-1)) injection for 30 min produced a rise in plasma cortisol without affecting plasma T(3) and T(4). On the contrary, blocking of adrenaline action with a non-selective blocker, propranolol (25 ng g(-1)) for 90 min reduced plasma cortisol along with plasma T(4) and that indicate a possible interference of these hormones in the absence of adrenaline challenge. Similarly, a reduction in plasma T(3) was found after adrenaline challenge in propranolol pre-treated fish and that suggests a functional synergistic interference of adrenaline with T(3). Adrenaline challenge in these fish, however, failed to abolish this propranolol effect. The remarkable systemic hypercapnia and acidosis by propranolol pre-treatment were reversed by adrenaline challenge, pointing to a direct action of adrenaline on acid-base indices probably by a mechanism which may not require β-adrenergic receptor systems. Interestingly, the prominent adrenaline-induced hyperglycemia, hyperlactemia and hyperuremea were not altered by propranolol treatment. Similarly, adrenaline challenge promoted and propranolol reduced the osmotic competencies of the gills, kidneys and liver of this fish as evident in the sodium and proton pump activities. The modified physiologic actions of adrenaline and its modified interaction with THs and cortisol in blocked fish indicate an interaction of adrenaline with cortisol and THs. Our physiologic evidences thus support the hypothesis of the phenomenon of inter-hormonal interference. Copyright © 2012 Elsevier Inc. All rights reserved.

Genetic resistance to rhabdovirus infection in teleost fish is paralleled to the derived cell resistance status.

PubMed

Verrier, Eloi R; Langevin, Christelle; Tohry, Corinne; Houel, Armel; Ducrocq, Vincent; Benmansour, Abdenour; Quillet, Edwige; Boudinot, Pierre

2012-01-01

Genetic factors of resistance and predisposition to viral diseases explain a significant part of the clinical variability observed within host populations. Predisposition to viral diseases has been associated to MHC haplotypes and T cell immunity, but a growing repertoire of innate/intrinsic factors are implicated in the genetic determinism of the host susceptibility to viruses. In a long-term study of the genetics of host resistance to fish rhabdoviruses, we produced a collection of double-haploid rainbow trout clones showing a wide range of susceptibility to Viral Hemorrhagic Septicemia Virus (VHSV) waterborne infection. The susceptibility of fibroblastic cell lines derived from these clonal fish was fully consistent with the susceptibility of the parental fish clones. The mechanisms determining the host resistance therefore did not associate with specific host immunity, but rather with innate or intrinsic factors. One cell line was resistant to rhabdovirus infection due to the combination of an early interferon IFN induction--that was not observed in the susceptible cells--and of yet unknown factors that hamper the first steps of the viral cycle. The implication of IFN was well consistent with the wide range of resistance of this genetic background to VSHV and IHNV, to the birnavirus IPNV and the orthomyxovirus ISAV. Another cell line was even more refractory to the VHSV infection through different antiviral mechanisms. This collection of clonal fish and isogenic cell lines provides an interesting model to analyze the relative contribution of antiviral pathways to the resistance to different viruses.

Factors controlling the early stages of viral haemorrhagic septicaemia epizootics: Low exposure levels, virus amplification and fish-to-fish transmission

USGS Publications Warehouse

Hershberger, P.K.; Gregg, J.L.; Grady, C.A.; Hart, L.M.; Roon, S.R.; Winton, J.R.

2011-01-01

Viral haemorrhagic septicaemia virus, Genogroup IVa (VHSV), was highly infectious to Pacific herring, Clupea pallasii (Valenciennes), even at exposure doses occurring below the threshold of sensitivity for a standard viral plaque assay; however, further progression of the disease to a population-level epizootic required viral amplification and effective fish-to-fish transmission. Among groups of herring injected with VHSV, the prevalence of infection was dose-dependent, ranging from 100%, 75% and 38% after exposure to 19, 0.7 and 0.07 plaque-forming units (PFU)/fish, respectively. Among Pacific herring exposed to waterborne VHSV (140PFUmL-1), the prevalence of infection, geometric mean viral tissue titre and cumulative mortality were greater among cohabitated herring than among cohorts that were held in individual aquaria, where fish-to-fish transmission was prevented. Fish-to-fish transmission among cohabitated herring probably occurred via exposure to shed virus which peaked at 680PFUmL-1; shed virus was not detected in the tank water from any isolated individuals. The results provide insights into mechanisms that initiate epizootic cascades in populations of wild herring and have implications for the design of VHSV surveys in wild fish populations. ?? Published 2011. This article is a US Government work and is in the public domain in the USA.

Ciguatera fish poisoning in an international ship crew in Saint John Canada: 2015

PubMed Central

Muecke, C; Hamper, L; Skinner, AL; Osborne, C

2015-01-01

An international ship crew presented for medical care in Saint John, New Brunswick, following rapid onset of gastrointestinal and in some cases neurological and cardiac symptoms after a common fish meal. Ciguatera poisoning was identified as the cause of illness. This report describes the public health investigation and management of this incident, including collaboration between the implicated provincial and federal authorities. PMID:29769923

Temporal variability in estuarine fish otolith elemental fingerprints: Implications for connectivity assessments

NASA Astrophysics Data System (ADS)

Reis-Santos, Patrick; Gillanders, Bronwyn M.; Tanner, Susanne E.; Vasconcelos, Rita P.; Elsdon, Travis S.; Cabral, Henrique N.

2012-10-01

The chemical composition of fish otoliths can provide valuable information for determining the nursery value of estuaries to adult populations of coastal fishes. However, understanding temporal variation in elemental fingerprints at different scales is important as it can potentially confound spatial discrimination among estuaries. Otolith elemental ratios (Li:Ca, Mg:Ca, Mn:Ca, Cu:Ca, Sr:Ca, Ba:Ca and Pb:Ca) of Platichthys flesus and Dicentrarchus labrax, from several estuaries along the Portuguese coast in two years and three seasons (spring, summer and autumn) within a year, were determined via Laser Ablation Inductively Coupled Plasma Mass Spectrometry. Elemental fingerprints varied significantly among years and seasons within a year but we achieved accurate classifications of juvenile fish to estuarine nursery of origin (77-96% overall cross-validated accuracy). Although elemental fingerprints were year-specific, variation among seasons did not hinder spatial discrimination. Estuarine fingerprints of pooled seasonal data were representative of the entire juvenile year class and attained high discrimination (77% and 80% overall cross-validated accuracy for flounder and sea bass, respectively). Incorporating seasonal variation resulted in up to an 11% increase in correct classification of individual estuaries, in comparison to seasons where accuracies were lowest. Overall, understanding the implications of temporal variations in otolith chemistry for spatial discrimination is key to establish baseline data for connectivity studies.

Divergent Expression Patterns and Function Implications of Four nanos Genes in a Hermaphroditic Fish, Epinephelus coioides

PubMed Central

Sun, Zhi-Hui; Wang, Yang; Lu, Wei-Jia; Li, Zhi; Liu, Xiao-Chun; Li, Shui-Sheng; Zhou, Li; Gui, Jian-Fang

2017-01-01

Multiple nanos genes have been characterized in several fishes, but the functional implications of their various expression patterns remain unclear. In this study, we identified and characterized four nanos genes from a hermaphroditic fish orange-spotted grouper, Epinephelus coioides. Ecnanos1a and Ecnanos1b show divergent expression patterns, and the dynamic expression change of Ecnanos1a in pituitaries during sex change is associated with testis differentiation and spermatogenesis. Ecnanos2 and Ecnanos3 might be germline stem cells (GSCs) and primordial germ cells (PGCs)-specific markers, respectively. Significantly, Ecnanos3 3′-untranslated region (UTR) is necessary for PGC specific expression, where a non-canonical “GCACGTTT” sequence is required for miR-430-mediated repression of Ecnanos3 RNA. Furthermore, grouper Dead end (Dnd) can relieve miR-430 repression in PGCs by associating with a 23 bp U-rich region (URR) in Ecnanos3 3′-UTR. The current study revealed the functional association of multiple nanos genes with PGC formation and germ cell development in orange-spotted grouper, and opened up new possibilities for developing biotechnologies through utilizing the associations between Ecnanos3 and PGCs or between Ecnanos2 and GSCs in the hermaphroditic fish. PMID:28333083

[Toxin profiles in fish implicated in ciguatera fish poisoning in Amami and Kakeroma Islands, Kagoshima Prefecture, Japan].

PubMed

Yogi, Kentaro; Oshiro, Naomasa; Matsuda, Seiko; Sakugawa, Satsuki; Matsuo, Toshiaki; Yasumoto, Takeshi

2013-01-01

Ciguatoxins (CTXs) responsible for ciguatera fish poisoning (CFP) in Amami Islands, Kagoshima, Japan in 2008 were determined by LC-MS/MS analysis. Ciguatoxin-1B (CTX1B), 54-deoxyCTX1B, and 52-epi-54-deoxyCTX1B were detected in Variola louti and Lutjanus monostigma. The toxin profile distinctly differed from that of a CFP-related fish from Miyazaki, which mainly contained ciguatoxin-3C type toxins. Toxin profiles were species-specific, as observed in fish from Okinawa. The LC-MS/MS and mouse bioassay (MBA) methods produced comparable data, though 54-deoxyCTX1B was not taken into consideration owing to the lack of toxicity data. To improve assessment, toxicity data for this compound are needed. A reef fish caught on the same occasion and judged nontoxic by MBA (<0.025 MU/g) was found to contain low levels of CTX, indicating a potential risk for CFP.

Mercury contamination in Southern New England coastal fisheries and dietary habits of recreational anglers and their families: Implications to human health and issuance of consumption advisories

PubMed Central

Taylor, David L.; Williamson, Patrick R.

2016-01-01

Total mercury (Hg) was measured in coastal fishes from Southern New England (RI, USA), and Hg exposure was estimated for anglers and family members that consumed these resources. Fish Hg was positively related to total length (n = 2028 across 7 fish species), and interspecies differences were evident among legally harvestable fish. Many recreational anglers and their families experienced excessively high Hg exposure rates, which was attributed to the enriched Hg content of frequently consumed fishes. Specifically, 51.5% of participants in this study had Hg exposures exceeding the US EPA reference dose, including 50.0% of women of childbearing years. These results are noteworthy given that Hg neurotoxicity occurs in adults and children from direct and prenatal low-dose exposure. Moreover, this study underscores the need for geographic-specific research that accounts for small-scale spatial variations in fish Hg and dietary habits of at-risk human populations. PMID:27595617

Whole genome sequencing of the fish pathogen Francisella noatunensis subsp. orientalis Toba04 gives novel insights into Francisella evolution and pathogenecity

PubMed Central

2012-01-01

Background Francisella is a genus of gram-negative bacterium highly virulent in fishes and human where F. tularensis is causing the serious disease tularaemia in human. Recently Francisella species have been reported to cause mortality in aquaculture species like Atlantic cod and tilapia. We have completed the sequencing and draft assembly of the Francisella noatunensis subsp. orientalisToba04 strain isolated from farmed Tilapia. Compared to other available Francisella genomes, it is most similar to the genome of Francisella philomiragia subsp. philomiragia, a free-living bacterium not virulent to human. Results The genome is rearranged compared to the available Francisella genomes even though we found no IS-elements in the genome. Nearly 16% percent of the predicted ORFs are pseudogenes. Computational pathway analysis indicates that a number of the metabolic pathways are disrupted due to pseudogenes. Comparing the novel genome with other available Francisella genomes, we found around 2.5% of unique genes present in Francisella noatunensis subsp. orientalis Toba04 and a list of genes uniquely present in the human-pathogenic Francisella subspecies. Most of these genes might have transferred from bacterial species through horizontal gene transfer. Comparative analysis between human and fish pathogen also provide insights into genes responsible for pathogenecity. Our analysis of pseudogenes indicates that the evolution of Francisella subspecies’s pseudogenes from Tilapia is old with large number of pseudogenes having more than one inactivating mutation. Conclusions The fish pathogen has lost non-essential genes some time ago. Evolutionary analysis of the Francisella genomes, strongly suggests that human and fish pathogenic Francisella species have evolved independently from free-living metabolically competent Francisella species. These findings will contribute to understanding the evolution of Francisella species and pathogenesis. PMID:23131096

Biogeochemical and ecological impacts of boundary currents in the Indian Ocean

NASA Astrophysics Data System (ADS)

Hood, Raleigh R.; Beckley, Lynnath E.; Wiggert, Jerry D.

2017-08-01

Monsoon forcing and the unique geomorphology of the Indian Ocean basin result in complex boundary currents, which are unique in many respects. In the northern Indian Ocean, several boundary current systems reverse seasonally. For example, upwelling coincident with northward-flowing currents along the coast of Oman during the Southwest Monsoon gives rise to high productivity which also alters nutrient stoichiometry and therefore, the species composition of the resulting phytoplankton blooms. During the Northeast Monsoon most of the northern Indian Ocean boundary currents reverse and favor downwelling. Higher trophic level species have evolved behavioral responses to these seasonally changing conditions. Examples from the western Arabian Sea include vertical feeding migrations of a copepod (Calanoides carinatus) and the reproductive cycle of a large pelagic fish (Scomberomorus commerson). The impacts of these seasonal current reversals and changes in upwelling and downwelling circulations are also manifested in West Indian coastal waters, where they influence dissolved oxygen concentrations and have been implicated in massive fish kills. The winds and boundary currents reverse seasonally in the Bay of Bengal, though the associated changes in upwelling and productivity are less pronounced. Nonetheless, their effects are observed on the East Indian shelf as, for example, seasonal changes in copepod abundance and zooplankton community structure. In contrast, south of Sri Lanka seasonal reversals in the boundary currents are associated with dramatic changes in the intensity of coastal upwelling, chlorophyll concentration, and catch per unit effort of fishes. Off the coast of Java, monsoon-driven changes in the currents and upwelling strongly impact chlorophyll concentrations, seasonal vertical migrations of zooplankton, and sardine catch in Bali Strait. In the southern hemisphere the Leeuwin is a downwelling-favorable current that flows southward along western Australia, though local wind forcing can lead to transient near shore current reversals and localized coastal upwelling. The poleward direction of this eastern boundary current is unique. Due to its high kinetic energy the Leeuwin Current sheds anomalous, relatively high chlorophyll, warm-core, downwelling eddies that transport coastal diatom communities westward into open ocean waters. Variations in the Leeuwin transport and eddy generation impact many higher trophic level species including the recruitment and fate of rock lobster (Panulirus cygnus) larvae. In contrast, the transport of the Agulhas Current is very large, with sources derived from the Mozambique Channel, the East Madagascar Current and the southwest Indian Ocean sub-gyre. Dynamically, the Agulhas Current is upwelling favorable; however, the spatial distribution of prominent surface manifestations of upwelling is controlled by local wind and topographic forcing. Meanders and eddies in the Agulhas Current propagate alongshore and interact with seasonal changes in the winds and topographic features. These give rise to seasonally variable localized upwelling and downwelling circulations with commensurate changes in primary production and higher trophic level responses. Due to the strong influence of the Agulhas Current, many neritic fish species in southeast Africa coastal waters have evolved highly selective behaviors and reproductive patterns for successful retention of planktonic eggs and larvae. For example, part of the Southern African sardine (Sardinops sagax) stock undergoes a remarkable northward migration enhanced by transient cyclonic eddies in the shoreward boundary of the Agulhas Current. There is evidence from the paleoceanographic record that these currents and their biogeochemical and ecological impacts have changed significantly over glacial to interglacial timescales. These changes are explored as a means of providing insight into the potential impacts of climate change in the Indian Ocean.

An injectable acoustic transmitter for juvenile salmon

NASA Astrophysics Data System (ADS)

Deng, Z. D.; Carlson, T. J.; Li, H.; Xiao, J.; Myjak, M. J.; Lu, J.; Martinez, J. J.; Woodley, C. M.; Weiland, M. A.; Eppard, M. B.

2015-01-01

Salmon recovery and the potential detrimental effects of dams on fish have been attracting national attention due to the environmental and economic implications. In recent years acoustic telemetry has been the primary method for studying salmon passage. However, the size of the existing transmitters limits the minimum size of fish that can be studied, introducing a bias to the study results. We developed the first acoustic fish transmitter that can be implanted by injection instead of surgery. The new injectable transmitter lasts four times longer and weighs 30% less than other transmitters. Because the new transmitter costs significantly less to use and may substantially reduce adverse effects of implantation and tag burden, it will allow for study of migration behavior and survival of species and sizes of fish that have never been studied before. The new technology will lead to critical information needed for salmon recovery and the development of fish-friendly hydroelectric systems.

An injectable acoustic transmitter for juvenile salmon

PubMed Central

Deng, Z. D.; Carlson, T. J.; Li, H.; Xiao, J.; Myjak, M. J.; Lu, J.; Martinez, J. J.; Woodley, C. M.; Weiland, M. A.; Eppard, M. B.

2015-01-01

Salmon recovery and the potential detrimental effects of dams on fish have been attracting national attention due to the environmental and economic implications. In recent years acoustic telemetry has been the primary method for studying salmon passage. However, the size of the existing transmitters limits the minimum size of fish that can be studied, introducing a bias to the study results. We developed the first acoustic fish transmitter that can be implanted by injection instead of surgery. The new injectable transmitter lasts four times longer and weighs 30% less than other transmitters. Because the new transmitter costs significantly less to use and may substantially reduce adverse effects of implantation and tag burden, it will allow for study of migration behavior and survival of species and sizes of fish that have never been studied before. The new technology will lead to critical information needed for salmon recovery and the development of fish-friendly hydroelectric systems. PMID:25630763

Hot moments in spawning aggregations: implications for ecosystem-scale nutrient cycling

NASA Astrophysics Data System (ADS)

Archer, Stephanie K.; Allgeier, Jacob E.; Semmens, Brice X.; Heppell, Scott A.; Pattengill-Semmens, Christy V.; Rosemond, Amy D.; Bush, Phillippe G.; McCoy, Croy M.; Johnson, Bradley C.; Layman, Craig A.

2015-03-01

Biogeochemical hot moments occur when a temporary increase in availability of one or more limiting reactants results in elevated rates of biogeochemical reactions. Many marine fish form transient spawning aggregations, temporarily increasing their local abundance and thus nutrients supplied via excretion at the aggregation site. In this way, nutrients released by aggregating fish could create a biogeochemical hot moment. Using a combination of empirical and modeling approaches, we estimate nitrogen and phosphorus supplied by aggregating Nassau grouper ( Epinephelus striatus). Data suggest aggregating grouper supply up to an order-of-magnitude more nitrogen and phosphorus than daily consumer-derived nutrient supply on coral reefs without aggregating fish. Comparing current and historic aggregation-level excretion estimates shows that overfishing reduced nutrients supplied by aggregating fish by up to 87 %. Our study illustrates a previously unrecognized ecosystem viewpoint regarding fish spawning aggregations and provides an additional perspective on the repercussions of their overexploitation.

Ocean acidification alters the otoliths of a pantropical fish species with implications for sensory function.

PubMed

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.

Ocean acidification alters the otoliths of a pantropical fish species with implications for sensory function

PubMed Central

Bignami, Sean; Enochs, Ian C.; Manzello, Derek P.; Sponaugle, Su; Cowen, Robert K.

2013-01-01

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. PMID:23589887

Shock, Stress or Signal? Implications of Freshwater Flows for a Top-Level Estuarine Predator

PubMed Central

Taylor, Matthew D.; van der Meulen, Dylan E.; Ives, Matthew C.; Walsh, Chris T.; Reinfelds, Ivars V.; Gray, Charles A.

2014-01-01

Physicochemical variability in estuarine systems plays an important role in estuarine processes and in the lifecycles of estuarine organisms. In particular, seasonality of freshwater inflow to estuaries may be important in various aspects of fish lifecycles. This study aimed to further understand these relationships by studying the movements of a top-level estuarine predator in response to physicochemical variability in a large, temperate south-east Australian estuary (Shoalhaven River). Mulloway (Argyrosomus japonicus, 47–89 cm total length) were surgically implanted with acoustic transmitters, and their movements and migrations monitored over two years via fixed-position VR2W acoustic receivers configured in a linear array along the length of the estuary. The study period included a high degree of abiotic variability, with multiple pulses (exponentially high flows over a short period of time) in fresh water to the estuary, as well as broader seasonal variation in flow, temperature and conductivity. The relative deviation of fish from their modal location in the estuary was affected primarily by changes in conductivity, and smaller fish (n = 4) tended to deviate much further downstream from their modal position in the estuary than larger fish (n = 8). High-flow events which coincided with warmer temperatures tended to drive mature fish down the estuary and potentially provided a spawning signal to stimulate aggregation of adults near the estuary mouth; however, this relationship requires further investigation. These findings indicate that pulse and press effects of freshwater inflow and associated physicochemical variability play a role in the movements of mulloway, and that seasonality of large freshwater flows may be important in spawning. The possible implications of river regulation and the extraction of freshwater for consumptive uses on estuarine fishes are discussed. PMID:24752585

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

PubMed Central

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

2014-01-01

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

Understanding behavioral responses of fish to pheromones in natural freshwater environments

USGS Publications Warehouse

Johnson, Nicholas S.; Li, Weiming

2010-01-01

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

Biotransformation and induction: implications for toxicity, bioaccumulation and monitoring of environmental xenobiotics in fish.

PubMed Central

Kleinow, K M; Melancon, M J; Lech, J J

1987-01-01

Biotransformation of xenobiotics in fish occurs by many of the same reactions as in mammals. These reactions have been shown to affect the bioaccumulation, persistence, residue dynamics, and toxicity of select chemicals in fish. P-450-dependent monooxygenase activity of fish can be induced by polycyclic aromatic hydrocarbons, but phenobarbital-type agents induce poorly, if at all. Fish monooxygenase activity exhibits ideal temperature compensation and sex-related variation. Induction of monooxygenase activity by polycyclic aromatic hydrocarbons can result in qualitative as well as quantitative changes in the metabolic profile of a chemical. Induction can also alter toxicity. In addition, multiple P-450 isozymes have been described for several fish species. The biotransformation products of certain chemicals have been related to specific P-450 isozymes, and the formation of these products can be influenced by induction. Exposure of fish to low levels of certain environmental contaminants has resulted in induction of specific monooxygenase activities and monitoring of such activities has been suggested as a means of identifying areas of pollutant exposure in the wild. PMID:3297653

Improved Physicochemical Properties of Yogurt Fortified with Fish Oil/γ-Oryzanol by Nanoemulsion Technology.

PubMed

Zhong, Jinfeng; Yang, Rong; Cao, Xiaoyi; Liu, Xiong; Qin, Xiaoli

2018-01-02

Fish oil has several dietary benefits, but its application in food formulations is limited because of its poor water-solubility, easy oxidation and strong odor. The purposes of this study were to produce a fish oil/γ-oryzanol nanoemulsion and to evaluate the effect of adding this nanoemulsion on the physicochemical and sensory characteristics of yogurts. Adding fish oil/γ-oryzanol nanoemulsion resulted in a significant reduction in the acidity and syneresis of yogurt. Yogurt with the nanoemulsion had significantly lower peroxide value (0.28 mmol/L after 21 days) and higher retention of eicosapentaenoic acid and docosahexaenoic acid contents (decreased to 95% and 94% of its initial value, respectively) than yogurt with fish oil/γ-oryzanol (peroxide value = 0.65 mmol/L; eicosapentaenoic acid and docosahexaenoic acid contents decreased to 72% and 53% of its initial value, respectively). Fish oil/γ-oryzanol nanoemulsion incorporated into yogurt had closer sensory attributes scores to plain yogurt. This study may have important implications for the application of fish oil/γ-oryzanol nanoemulsion in yogurt.

The Lower Danube River-Danube Delta-North West Black Sea: A pivotal area of major interest for the past, present and future of its fish fauna--A short review.

PubMed

Bănăduc, Doru; Rey, Sonia; Trichkova, Teodora; Lenhardt, Mirjana; Curtean-Bănăduc, Angela

2016-03-01

The complex Danube-Black Sea geoecosystem, created by a unique combination of integrated biotopes and biocoenoses related forces and counter-forces in time and space, forms a rich "ichthyosystem". The equilibrium among the fish species captured in the Danube Delta reveals its structural and functional roles in the connectivity of the Danube and Black Sea. The key role of the delta is evidenced by the fact that 57.26% of the Lower Danube-Danube Delta-North West Black Sea fish species use two or three of the subsystems in terms of habitats. Therefore, this convergence area can be considered to be a dynamic and rich "ichthyosystem", with three subsystems. All three evolved interdependently, which permits their flexibility and adaptation in an interdependent way. The habitat heterogeneity, native economic and conservation priority fish species of the Lower Danube-Danube Delta-North Western Black Sea have decreased significantly, and there are no indications that this trend will be halted soon. The Danube "sub-ichtyosystem" seems to be more directly affected than the others. The Lower Danube-Danube Delta-North Western Black Sea "ichthyosystem" exhibits a significant level of flexibility, resilience and adaptation over geological time, but has become much more sensitive to environmental perturbations due to the last century of human impact. This "ichthyosystem" is affected by non-native fish species. The study area represents an interdependent ecological net, without which the specific "ichthyosystem" formed over geological time will disappear. The studied ecological net fish fauna is an accurate indicator of various human pressures. The Lower Danube-Danube Delta-North West Black Sea geoecosystem, in which the Danube Delta provides the pivotal habitat element, is the matrix for a unique "ichthyosystem." However, human impacts decrease its resilience and can induce its extinction. Copyright © 2015 Elsevier B.V. All rights reserved.

Toward a loss of functional diversity in stream fish assemblages under climate change.

PubMed

Buisson, Laëtitia; Grenouillet, Gaël; Villéger, Sébastien; Canal, Julie; Laffaille, Pascal

2013-02-01

The assessment of climate change impacts on biodiversity has so far been biased toward the taxonomic identification of the species likely either to benefit from climate modifications or to experience overall declines. There have still been few studies intended to correlate the characteristics of species to their sensitivity to climate change, even though it is now recognized that functional trait-based approaches are promising tools for addressing challenges related to global changes. In this study, two functional indices (originality and uniqueness) were first measured for 35 fish species occurring in French streams. They were then combined to projections of range shifts in response to climate change derived from species distribution models. We set out to investigate: (1) the relationship between the degrees of originality and uniqueness of fish species, and their projected response to future climate change; and (2) the consequences of individual responses of species for the functional diversity of fish assemblages. After accounting for phylogenetic relatedness among species, we have demonstrated that the two indices used measure two complementary facets of the position of fish species in a functional space. We have also rejected the hypothesis that the most original and/or less redundant species would necessarily experience the greatest declines in habitat suitability as a result of climate change. However, individual species range shifts could lead simultaneously both to a severe decline in the functional diversity of fish assemblages, and to an increase in the functional similarity among assemblages, supporting the hypothesis that disturbance favors communities with combination of common traits and biotic homogenization as well. Our findings therefore emphasize the importance of going beyond the simple taxonomic description of diversity to provide a better assessment of the likely future effects of environmental changes on biodiversity, thus helping to design more effective conservation and management measures. © 2012 Blackwell Publishing Ltd.

Inventory of Anchialine Pools in Hawaii's National Parks

USGS Publications Warehouse

Foote, David

2005-01-01

BACKGROUND Anchialine (?near the sea?) pools are rare and localized brackish waters along coastal lava flows that exhibit tidal fluctuations without a surface connection with the ocean (Fig. 1). In Hawai`i, these pools were frequently excavated or otherwise modified by Hawaiians to serve as sources of drinking water, baths and fish ponds. National Parks in Hawai`i possess the full spectrum of pool types, from walled fish ponds to undisturbed pools in collapsed lava tubes, cracks and caves. Pools contain relatively rare and unique fauna threatened primarily by invasive species and habitat loss. In collaboration with the National Park Service?s Inventory and Monitoring Program, the U.S. Geological Survey?s Pacific Island Ecosystems Research Center undertook inventories of these unique ecosystems in two National Parks on the island of Hawai`i: Hawai`i Volcanoes National Park and Kaloko-Honokohau National Historical Park.

FDA-EPA Public Health Guidance on Fish Consumption: A Case Study on Informal Interagency Cooperation in "Shared Regulatory Space".

PubMed

Holden, Mark

2015-01-01

This article is a case study on how administrative agencies interact with each other in cases of shared regulatory jurisdiction. The theoretical literature on the topic of overlapping jurisdiction both (1) makes predictions about how agencies are expected to behave when they share jurisdiction, and (2) in recent iterations argues that overlapping jurisdiction can confer unique policymaking benefits. Through the lens of that theoretical literature, this article examines the relations between the Food and Drug Administration (FDA) and the Environmental Protection Agency (EPA) regarding the public health risks posed by mercury in fish. It concludes that the FDA-EPA case study (1) corroborates the extant theoretical accounts of how agencies behave in cases of overlapping jurisdiction, (2) supports the conclusion of the recent scholarship that overlapping jurisdiction can confer unique policy benefits, and (3) reveals a few wrinkles not given adequate treatment in the extant literature.

Clinical diagnosis and chemical confirmation of ciguatera fish poisoning in New South Wales, Australia.

PubMed

Farrell, Hazel; Zammit, Anthony; Manning, Jennifer; Shadbolt, Craig; Szabo, Lisa; Harwood, D Tim; McNabb, Paul; Turahui, John A; van den Berg, Debra J

2016-03-31

Ciguatera fish poisoning is common in tropical and sub-tropical areas and larger fish (> 10 kg) are more susceptible to toxin accumulation with age. Although the coastal climate of northern New South Wales is considered sub-tropical, prior to 2014 there has only been 1 documented outbreak of ciguatera fish poisoning from fish caught in the region. During February and March 2014, 2 outbreaks of ciguatera fish poisoning involved 4 and 9 individuals, respectively, both following consumption of Spanish mackerel from northern New South Wales coastal waters (Evans Head and Scotts Head). Affected individuals suffered a combination of gastrointestinal and neurological symptoms requiring hospital treatment. At least 1 individual was symptomatic up to 7 months later. Liquid chromatography-tandem mass spectrometry detected the compound Pacific ciguatoxin-1B at levels up to 1.0 µg kg(-1) in fish tissue from both outbreaks. During April 2015, another outbreak of ciguatera fish poisoning was reported in 4 individuals. The fish implicated in the outbreak was caught further south than the 2014 outbreaks (South West Rocks). Fish tissue was unavailable for analysis; however, symptoms were consistent with ciguatera fish poisoning. To our knowledge, these cases are the southernmost confirmed sources of ciguatera fish poisoning in Australia. Educational outreach to the fishing community, in particular recreational fishers was undertaken after the Evans Head outbreak. This highlighted the outbreak, species of fish involved and the range of symptoms associated with ciguatera fish poisoning. Further assessment of the potential for ciguatoxins to occur in previously unaffected locations need to be considered in terms of food safety.

Laboratory Class Project: Using a Cichlid Fish Display Tank to Teach Students about Complex Behavioral Systems.

PubMed

Nolan, Brian C

2010-01-01

Laboratory activities serve several important functions in undergraduate science education. For neuroscience majors, an important and sometimes underemphasized tool is the use of behavioral observations to help inform us about the consequences of changes that are occurring on a neuronal level. To help address this concern, the following laboratory exercise is presented. The current project tested the prediction that the most dominant fish in a tank of cichlids will have gained the most benefits of its position resulting in the greatest growth and hence, become the largest fish. More specifically: (1) is there evidence that a social hierarchy exists among the fish in our tank based on the number of aggressive acts among the four largest fish; (2) if so, does the apparent rank correspond to the size of the fish as predicted by previous studies? Focal sampling and behavior sampling of aggressive acts between fish were utilized in the data collection. Collectively, the data suggest a social dominance hierarchy may be in place with the following rank order from highest to lowest: Fish A > Fish B > Fish D > Fish C. While the largest (Fish A) seems to be at the top, Fish C ended up being ranked lower than Fish D despite the fact that Fish C is larger. Overall, the project was considered a success by the instructor and students. The students offered several suggestions that could improve future versions of this type of project, in particular concerning the process of constructing a poster about the project. The implications of the data and student learning outcomes are discussed.

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

PubMed

Arend, Kristin K; Bain, Mark B

2008-12-29

We explored how embayment watershed inputs, morphometry, and hydrology influence fish community structure among eight embayments located along the southeastern shoreline of Lake Ontario, New York, USA. Embayments differed in surface area and depth, varied in their connections to Lake Ontario and their watersheds, and drained watersheds representing a gradient of agricultural to forested land use. We related various physicochemical factors, including total phosphorus load, embayment area, and submerged vegetation, to differences in fish species diversity and community relative abundance, biomass, and size structure both among and within embayments. Yellow perch (Perca flavescens) and centrarchids numerically dominated most embayment fish communities. Biomass was dominated by piscivorous fishes including brown bullhead (Ameiurus nebulosus), bowfin (Amia calva), and northern pike (Esox lucius). Phosphorus loading influenced relative biomass, but not species diversity or relative abundance. Fish relative abundance differed among embayments; within embayments, fish abundance at individual sampling stations increased significantly with submerged vegetative cover. Relative biomass differed among embayments and was positively related to total phophorus loading and embayment area. Fish community size structure, based on size spectra analysis, differed among embayments, with the frequency of smaller-bodied fishes positively related to percent vegetation. The importance of total phosphorus loading and vegetation in structuring fish communities has implications for anthropogenic impacts to embayment fish communities through activities such as farming and residential development, reduction of cultural eutrophication, and shoreline development and maintenance.

Techno-socio-economic analysis of losses in capture fishery: a case study in Pelabuhan Ratu, Sukabumi, West Java Province

NASA Astrophysics Data System (ADS)

Nurhayati, A.; Purnomo, A. H.

2018-03-01

This research was aimed at analyzing factors influencing capture fisheries losses, focusing on technical, social and economic aspects at Pelabuhan Ratu. A case study was undertaken, through a survey involving 40 respondents. These respondents represented groups of fishers, collectors, middlemen, processors and consumers. The questions delivered in the survey was adapted from the Exploratory Fish Loss Assessment Method (EFLAM). Based on this research, the fish loss was detected in Palabuhan Ratu, which amounted to 4.25 % at the fisher level and 5.12 % in the following supply chains, due to some factors. It was found that among the technical factors, the most influential ones were handling of landed fish, fish sortation, fish size, fish shelf life and season. Among economic aspect, factors with the most significant influence were fish price fluctuation and price level; meanwhile, among the social factors, those that had the most significant influence was the revenue distribution system. Based on this, the relevant policy implication of this research was the need for effective programs which covers the development of cold chain and distribution facilities and infrastructure, and an improvement in skills and knowledge of fish derivative product processors.

Can personality predict individual differences in brook trout spatial learning ability?

USGS Publications Warehouse

White, S.L.; Wagner, Tyler; Gowan, C.; Braithwaite, V.A.

2017-01-01

While differences in individual personality are common in animal populations, understanding the ecological significance of variation has not yet been resolved. Evidence suggests that personality may influence learning and memory; a finding that could improve our understanding of the evolutionary processes that produce and maintain intraspecific behavioural heterogeneity. Here, we tested whether boldness, the most studied personality trait in fish, could predict learning ability in brook trout. After quantifying boldness, fish were trained to find a hidden food patch in a maze environment. Stable landmark cues were provided to indicate the location of food and, at the conclusion of training, cues were rearranged to test for learning. There was a negative relationship between boldness and learning as shy fish were increasingly more successful at navigating the maze and locating food during training trials compared to bold fish. In the altered testing environment, only shy fish continued using cues to search for food. Overall, the learning rate of bold fish was found to be lower than that of shy fish for several metrics suggesting that personality could have widespread effects on behaviour. Because learning can increase plasticity to environmental change, these results have significant implications for fish conservation.

Fish population dynamics in a seasonally varying wetland

USGS Publications Warehouse

DeAngelis, Donald L.; Trexler, Joel C.; Cosner, Chris; Obaza, Adam; Jopp, Fred

2010-01-01

Small fishes in seasonally flooded environments such as the Everglades are capable of spreading into newly flooded areas and building up substantial biomass. Passive drift cannot account for the rapidity of observed population expansions. To test the reaction-diffusion mechanism for spread of the fish, we estimated their diffusion coefficient and applied a reaction-diffusion model. This mechanism was also too weak to account for the spatial dynamics. Two other hypotheses were tested through modeling. The first--the 'refuge mechanism--hypothesizes that small remnant populations of small fishes survive the dry season in small permanent bodies of water (refugia), sites where the water level is otherwise below the surface. The second mechanism, which we call the 'dynamic ideal free distribution mechanism' is that consumption by the fish creates a prey density gradient and that fish taxis along this gradient can lead to rapid population expansion in space. We examined the two alternatives and concluded that although refugia may play an important role in recolonization by the fish population during reflooding, only the second, taxis in the direction of the flooding front, seems capable of matching empirical observations. This study has important implications for management of wetlands, as fish biomass is an essential support of higher trophic levels.

Fish-like propulsion of an airship with planar membrane dielectric elastomer actuators.

PubMed

Jordi, C; Michel, S; Fink, E

2010-06-01

The goal of our project is to mimic fish-like movement in air, propelling an airship by undulating its hull and a caudal fin. The activation of the fish-like body in air is realized by dielectric elastomers. These actuators are quite unique for their soft light-weight membrane structure and they are therefore very appropriate to the application on inflated structures. The principles of biomimetics for the structural design and movement are discussed and the conception and design of the airship is described. Various development tests, including wind tunnel testing and flight trials, were performed and the results obtained are presented. It can be shown that an 8 m model airship can be propelled in a fish-like manner in air and that the propulsion can be drastically improved by undulating the body as well as the caudal fin contrary to propulsion with only the caudal fin.

Bioluminescent symbionts of the Caribbean flashlight fish (Kryptophanaron alfredi) have a single rRNA operon.

PubMed

Wolfe, C J; Haygood, M G

1993-08-01

Ribosomal RNA (rRNA) operon copy number and gene order were determined for the luminous bacterial symbiont of Kryptophanaron alfredi, an anomalopid (flashlight) fish, and estimated for the luminous symbionts of 3 other fish families and of 3 luminous seawater isolates. Compared with the seawater isolates and other fish symbionts, the copy number of rRNA genes in the K. alfredi symbiont was radically reduced, although gene order appeared conserved among all the strains. The K. alfredi symbiont possesses only a single rRNA operon, whereas the other strains examined have minimum copy numbers ranging from 8 to 11. No difference in copy number was observed between light organ and seawater isolates of the same species, or between isolates of the same species from the light organs of 2 different host families. Thus, the anomalopid symbiosis appears unique among characterized light organ symbioses.

Do intracoelomic telemetry transmitters alter the post-release behaviour of migratory fish?

USGS Publications Warehouse

Wilson, Alexander D.M.; Hayden, Todd A.; Vandergoot, Christopher S.; Kraus, Richard T.; Dettmers, John M.; Cooke, Steven J.; Charles C. Krueger,

2016-01-01

Electronic tags have become a common tool in fish research, enhancing our understanding of how fish interact with their environment and move among different habitats, for estimating mortality and recording internal physiological states. An often-untested assumption of electronic tagging studies is that tagged fish are representative of untagged conspecifics and thus show ‘normal’ behaviour (e.g. movement rates, swimming activity, feeding). Here, we use a unique data set for potamadromous walleye (Sander vitreus) in Lake Huron and Lake Erie tributaries to assess whether the lack of appropriate controls in electronic tagging could seriously affect behavioural data. We used fish tagged in previous years and compared their migratory behaviour during the spawning season to fish tagged in a current year at the same location. The objective of the study was to determine whether intracoelomic acoustic tag implantation altered downstream movement of walleye after spawning. Fish tagged in a given season travelled slower downstream from two river spawning sites than fish tagged in previous years. Fish tagged one or two years earlier showed no differences between each other in downstream travel time, in contrast to fish tagged in a given year. Our results support notions that standard collection and intracoelomic tagging procedures can alter short-term behaviour (i.e. days, weeks, months), and as such, researchers should use caution when interpreting data collected over such time periods. Further, whenever possible, researchers should also explicitly evaluate post-tagging effects on behaviour as part of their experimental objectives.

Assessing three fish species ecological status in Colorado River, Grand Canyon based on physical habitat and population models.

PubMed

Yao, Weiwei; Chen, Yuansheng

2018-04-01

Colorado River is a unique ecosystem and provides important ecological services such as habitat for fish species as well as water power energy supplies. River management for this ecosystem requires assessment and decision support tools for fish which involves protecting, restoring as well as forecasting of future conditions. In this paper, a habitat and population model was developed and used to determine the levels of fish habitat suitability and population density in Colorado River between Lees Ferry and Lake Mead. The short term target fish populations are also predicted based on native fish recovery strategy. This model has been developed by combining hydrodynamics, heat transfer and sediment transport models with a habitat suitability index model and then coupling with habitat model into life stage population model. The fish were divided into four life stages according to the fish length. Three most abundant and typical native and non-native fish were selected as target species, which are rainbow trout (Oncorhynchus mykiss), brown trout (Salmo trutta) and flannelmouth sucker (Catostomus latipinnis). Flow velocity, water depth, water temperature and substrates were used as the suitability indicators in habitat model and overall suitability index (OSI) as well as weight usable area (WUA) was used as an indicator in population model. A comparison was made between simulated fish population alteration and surveyed fish number fluctuation during 2000 to 2009. The application of this habitat and population model indicates that this model can be accurate present habitat situation and targets fish population dynamics of in the study areas. The analysis also indicates the flannelmouth sucker population will steadily increase while the rainbow trout will decrease based on the native fish recovery scheme. Copyright © 2018. Published by Elsevier Inc.

Respondent driven sampling in a biomonitoring study of refugees from Burma in Buffalo, New York who eat Great Lakes fish.

PubMed

Liu, Ming; McCann, Molly; Lewis-Michl, Elizabeth; Hwang, Syni-An

2018-06-01

Refugees from Burma who consume fish caught from local waterbodies have increased risk of exposure to environmental contaminants. We used respondent driven sampling (RDS) to sample this hard-to-reach population for the first Biomonitoring of Great Lakes Populations program. In the current study, we examined the interview data and assessed the effectiveness of RDS to sample the unique population. In 2013, we used RDS to sample 205 Burmese refugees and immigrants residing in Buffalo, New York who consumed fish caught from Great Lakes waters. RDS-adjusted population estimates of sociodemographic characteristics, residential history, fish consumption related behaviors, and awareness of fish advisories were obtained. We also examined sample homophily and equilibrium to assess how well the RDS assumptions were met in the study. Our sample was diverse with respect to sex, age, years residing in Buffalo, years lived in a refugee camp, education, employment, and fish consumption behaviors, and each of these variables reached equilibrium by the end of recruitment. Burmese refugees in Buffalo consumed Great Lakes fish throughout the year; a majority of them consumed the fish more than two times per week during summer, and about one third ate local fish more than once per week in winter. An estimated 60% of Burmese refugees in Buffalo had heard about local fish advisories. RDS has the potential to be an effective methodology for sampling refugees and immigrants in conducting biomonitoring and environmental exposure assessment. Due to high fish consumption and limited awareness and knowledge of fish advisories, some refugee and immigrant populations are more susceptible to environmental contaminants. Increased awareness on local fish advisories is needed among these populations. Published by Elsevier GmbH.

Vertebrate Genome Evolution in the Light of Fish Cytogenomics and rDNAomics

PubMed Central

Howell, W. Mike

2018-01-01

To understand the cytogenomic evolution of vertebrates, we must first unravel the complex genomes of fishes, which were the first vertebrates to evolve and were ancestors to all other vertebrates. We must not forget the immense time span during which the fish genomes had to evolve. Fish cytogenomics is endowed with unique features which offer irreplaceable insights into the evolution of the vertebrate genome. Due to the general DNA base compositional homogeneity of fish genomes, fish cytogenomics is largely based on mapping DNA repeats that still represent serious obstacles in genome sequencing and assembling, even in model species. Localization of repeats on chromosomes of hundreds of fish species and populations originating from diversified environments have revealed the biological importance of this genomic fraction. Ribosomal genes (rDNA) belong to the most informative repeats and in fish, they are subject to a more relaxed regulation than in higher vertebrates. This can result in formation of a literal ‘rDNAome’ consisting of more than 20,000 copies with their high proportion employed in extra-coding functions. Because rDNA has high rates of transcription and recombination, it contributes to genome diversification and can form reproductive barrier. Our overall knowledge of fish cytogenomics grows rapidly by a continuously increasing number of fish genomes sequenced and by use of novel sequencing methods improving genome assembly. The recently revealed exceptional compositional heterogeneity in an ancient fish lineage (gars) sheds new light on the compositional genome evolution in vertebrates generally. We highlight the power of synergy of cytogenetics and genomics in fish cytogenomics, its potential to understand the complexity of genome evolution in vertebrates, which is also linked to clinical applications and the chromosomal backgrounds of speciation. We also summarize the current knowledge on fish cytogenomics and outline its main future avenues. PMID:29443947

Clinical and immunological characteristics of a pediatric population with food protein-induced enterocolitis syndrome (FPIES) to fish.

PubMed

González-Delgado, Purificación; Caparrós, Esther; Moreno, M Victoria; Clemente, Fernando; Flores, Emilio; Velásquez, Laura; Rubio, Gonzalo; Fernández, Javier

2016-05-01

Food protein-induced enterocolitis (FPIES) is an uncommon, non-IgE-mediated food allergy that usually debuts in infancy with profuse vomiting, lethargy, and pallor 2-4 h following ingestion of the offending food. Its immune mechanism is not known. We aimed to describe the clinical features and outcome of children with fish-FPIES as well as to investigate on cellular immune response implicated. Prospective and follow-up clinical study of children with FPIES by fish over a period between 2004 and 2013 was conducted. Measurement in vitro of both cytokine production in peripheral blood mononuclear cells (PBMCs) and expression of HLA-DR in monocyte-derived dendritic cells stimulated with fish extracts. Sixteen children (seven male and nine female) were included, with a mean age of onset at 10 months. Diagnosis was established after a median of 4 reactions. Twelve patients were treated in emergency room, and two were admitted in intensive care. Patch tests were positive in six patients. Skin prick tests (SPTs) and specific IgE to all fish tested were negative. Only three children reached tolerance at a mean age of 4.5 years. Eight children avoided fish because of positive oral food challenge (OFC) after 6 years of age. Other patients have not been challenged because of parent refusal to OFC or a recent diagnosis. TNF-α was increased in patients, and a significant elevation of the HLA-DR marker was also observed in these patients vs. control donors. FPIES caused by fish in many cases presents with severe clinical manifestations. Patch test has poor diagnostic value, and OFC is the gold standard to test tolerance. The cytokine TNF-α may be implicated in the clinical symptoms. Higher expression of HLA-DR in dendritic cells has also been detected in our patients. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

A comparative meta-analysis of maximal aerobic metabolism of vertebrates: implications for respiratory and cardiovascular limits to gas exchange.

PubMed

Hillman, Stanley S; Hancock, Thomas V; Hedrick, Michael S

2013-02-01

Maximal aerobic metabolic rates (MMR) in vertebrates are supported by increased conductive and diffusive fluxes of O(2) from the environment to the mitochondria necessitating concomitant increases in CO(2) efflux. A question that has received much attention has been which step, respiratory or cardiovascular, provides the principal rate limitation to gas flux at MMR? Limitation analyses have principally focused on O(2) fluxes, though the excess capacity of the lung for O(2) ventilation and diffusion remains unexplained except as a safety factor. Analyses of MMR normally rely upon allometry and temperature to define these factors, but cannot account for much of the variation and often have narrow phylogenetic breadth. The unique aspect of our comparative approach was to use an interclass meta-analysis to examine cardio-respiratory variables during the increase from resting metabolic rate to MMR among vertebrates from fish to mammals, independent of allometry and phylogeny. Common patterns at MMR indicate universal principles governing O(2) and CO(2) transport in vertebrate cardiovascular and respiratory systems, despite the varied modes of activities (swimming, running, flying), different cardio-respiratory architecture, and vastly different rates of metabolism (endothermy vs. ectothermy). Our meta-analysis supports previous studies indicating a cardiovascular limit to maximal O(2) transport and also implicates a respiratory system limit to maximal CO(2) efflux, especially in ectotherms. Thus, natural selection would operate on the respiratory system to enhance maximal CO(2) excretion and the cardiovascular system to enhance maximal O(2) uptake. This provides a possible evolutionary explanation for the conundrum of why the respiratory system appears functionally over-designed from an O(2) perspective, a unique insight from previous work focused solely on O(2) fluxes. The results suggest a common gas transport blueprint, or Bauplan, in the vertebrate clade.

Fatal methane and cyanide poisoning as a result of handling industrial fish: a case report and review of the literature.

PubMed

Cherian, M A; Richmond, I

2000-10-01

The potential health hazards of handling industrial fish are well documented. Wet fish in storage consume oxygen and produce poisonous gases as they spoil. In addition to oxygen depletion, various noxious agents have been demonstrated in association with spoilage including carbon dioxide, sulphur dioxide, and ammonia. A fatal case of methane and cyanide poisoning among a group of deep sea trawler men is described. Subsequent independent investigation as a result of this case led to the discovery of cyanides as a further potential noxious agent. This is thus the first case in which cyanide poisoning has been recognised as a potentially fatal complication of handling spoiled fish. The previous literature is reviewed and the implications of the current case are discussed.

Maximum Neutral Buoyancy Depth of Juvenile Chinook Salmon: Implications for Survival during Hydroturbine Passage

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pflugrath, Brett D.; Brown, Richard S.; Carlson, Thomas J.

This study investigated the maximum depth at which juvenile Chinook salmon Oncorhynchus tshawytscha can acclimate by attaining neutral buoyancy. Depth of neutral buoyancy is dependent upon the volume of gas within the swim bladder, which greatly influences the occurrence of injuries to fish passing through hydroturbines. We used two methods to obtain maximum swim bladder volumes that were transformed into depth estimations - the increased excess mass test (IEMT) and the swim bladder rupture test (SBRT). In the IEMT, weights were surgically added to the fishes exterior, requiring the fish to increase swim bladder volume in order to remain neutrallymore » buoyant. SBRT entailed removing and artificially increasing swim bladder volume through decompression. From these tests, we estimate the maximum acclimation depth for juvenile Chinook salmon is a median of 6.7m (range = 4.6-11.6 m). These findings have important implications to survival estimates, studies using tags, hydropower operations, and survival of juvenile salmon that pass through large Kaplan turbines typical of those found within the Columbia and Snake River hydropower system.« less

Real-time distribution of pelagic fish: combining hydroacoustics, GIS and spatial modelling at a fine spatial scale.

PubMed

Muška, Milan; Tušer, Michal; Frouzová, Jaroslava; Mrkvička, Tomáš; Ricard, Daniel; Seďa, Jaromír; Morelli, Federico; Kubečka, Jan

2018-03-29

Understanding spatial distribution of organisms in heterogeneous environment remains one of the chief issues in ecology. Spatial organization of freshwater fish was investigated predominantly on large-scale, neglecting important local conditions and ecological processes. However, small-scale processes are of an essential importance for individual habitat preferences and hence structuring trophic cascades and species coexistence. In this work, we analysed the real-time spatial distribution of pelagic freshwater fish in the Římov Reservoir (Czechia) observed by hydroacoustics in relation to important environmental predictors during 48 hours at 3-h interval. Effect of diurnal cycle was revealed of highest significance in all spatial models with inverse trends between fish distribution and predictors in day and night in general. Our findings highlighted daytime pelagic fish distribution as highly aggregated, with general fish preferences for central, deep and highly illuminated areas, whereas nighttime distribution was more disperse and fish preferred nearshore steep sloped areas with higher depth. This turnover suggests prominent movements of significant part of fish assemblage between pelagic and nearshore areas on a diel basis. In conclusion, hydroacoustics, GIS and spatial modelling proved as valuable tool for predicting local fish distribution and elucidate its drivers, which has far reaching implications for understanding freshwater ecosystem functioning.

Defining thresholds of sustainable impact on benthic communities in relation to fishing disturbance.

PubMed

Lambert, G I; Murray, L G; Hiddink, J G; Hinz, H; Lincoln, H; Hold, N; Cambiè, G; Kaiser, M J

2017-07-14

While the direct physical impact on seabed biota is well understood, no studies have defined thresholds to inform an ecosystem-based approach to managing fishing impacts. We addressed this knowledge gap using a large-scale experiment that created a controlled gradient of fishing intensity and assessed the immediate impacts and short-term recovery. We observed a mosaic of taxon-specific responses at various thresholds. The lowest threshold of significant lasting impact occurred between 1 and 3 times fished and elicited a decrease in abundance of 39 to 70% for some sessile epifaunal organisms (cnidarians, bryozoans). This contrasted with significant increases in abundance and/or biomass of scavenging species (epifaunal echinoderms, infaunal crustaceans) by two to four-fold in areas fished twice and more. In spite of these significant specific responses, the benthic community structure, biomass and abundance at the population level appeared resilient to fishing. Overall, natural temporal variation in community metrics exceeded the effects of fishing in this highly dynamic study site, suggesting that an acute level of disturbance (fished over six times) would match the level of natural variation. We discuss the implications of our findings for natural resources management with respect to context-specific human disturbance and provide guidance for best fishing practices.

Fish, mercury, selenium and cardiovascular risk: current evidence and unanswered questions.

PubMed

Mozaffarian, Dariush

2009-06-01

Controversy has arisen among the public and in the media regarding the health effects of fish intake in adults. Substantial evidence indicates that fish consumption reduces coronary heart disease mortality, the leading cause of death in developed and most developing nations. Conversely, concerns have grown regarding potential effects of exposure to mercury found in some fish. Seafood species are also rich in selenium, an essential trace element that may protect against both cardiovascular disease and toxic effects of mercury. Such protective effects would have direct implications for recommendations regarding optimal selenium intake and for assessing the potential impact of mercury exposure from fish intake in different populations. Because fish consumption appears to have important health benefits in adults, elucidating the relationships between fish intake, mercury and selenium exposure, and health risk is of considerable scientific and public health relevance. The evidence for health effects of fish consumption in adults is reviewed, focusing on the strength and consistency of evidence and relative magnitudes of effects of omega-3 fatty acids, mercury, and selenium. Given the preponderance of evidence, the focus is on cardiovascular effects, but other potential health effects, as well as potential effects of polychlorinated biphenyls and dioxins in fish, are also briefly reviewed. The relevant current unanswered questions and directions of further research are summarized.

The role of fish in a globally changing food system

USGS Publications Warehouse

Lynch, Abigail J.; MacMillan, J. Randy

2017-01-01

Though humans have been fishing for food since they first created tools to hunt, modern food systems are predominately terrestrial focused and fish are frequently overlooked. Yet, within the global food system, fish play an important role in meeting current and future food needs. Capture fisheries are the last large-scale “wild” food, and aquaculture is the fastest growing food production sector in the world. Currently, capture fisheries and aquaculture provide 4.3 billion people with at least 15% of their animal protein. In addition to providing protein and calories, fish are important sources of critical vitamins and vital nutrients that are difficult to acquire through other food sources. As the climate changes, human populations will continue to grow, cultural tastes will evolve, and fish populations will respond. Sustainable fisheries and aquaculture are poised to fill demand for food not met by terrestrial food systems. Climate change and other global changes will increase, decrease, or modify many wild fish populations and aquaculture systems. Understanding the knowledge gaps around these implications for global change on fish production is critical. Applied research and adaptive management techniques can assist with the necessary evolution of sustainable food systems to include a stronger emphasis on fish and other aquatic organisms.

Factors affecting swimming performance of fasted rainbow trout with implications of exhaustive exercise on overwinter mortality

USGS Publications Warehouse

Simpkins, D.G.; Hubert, W.A.; Del Rio, C.M.; Rule, D.C.

2004-01-01

We evaluated the effects of body size, water temperature, and sustained swimming activity on swimming performance and the effects of exhaustive exercise on mortality of fasted juvenile rainbow trout. Fasting caused swimming performance to decline more rapidly for small fish than large fish, and warmer water temperatures and sustained swimming activity further decreased swimming performance. Exhaustive exercise increased mortality among fasted fish. Our observations suggest that juvenile rainbow trout with little or no food intake during winter can swim for long periods of time with little effect on mortality, but swimming to exhaustion can enhance mortality, especially among the smallest juveniles.

Threat Assessment and Targeted Violence at Institutions of Higher Education: Implications for Policy and Practice Including Unique Considerations for Community Colleges

ERIC Educational Resources Information Center

Bennett, Laura; Bates, Michael

2015-01-01

This article provides an overview of the research on targeted violence, including campus violence, and the implications for policy and practice at institutions of higher education. Unique challenges of threat assessment in the community college setting are explored, and an overview of an effective threat assessment policy and team at William…

The Influence of Fish Length on Tissue Mercury Dynamics: Implications for Natural Resource Management and Human Health Risk

PubMed Central

Sackett, Dana K.; Cope, W. Gregory; Rice, James A.; Aday, D. Derek

2013-01-01

Consumption of fish has well-known human health benefits, though some fish may contain elevated levels of mercury (Hg) that are especially harmful to developing children. Fish length is most often the basis for establishing fishery harvest regulations that determine which fish will ultimately be consumed by humans. It is, therefore, essential to quantify the relationship between fish length and Hg accumulation in regard to harvest regulations for effective fishery and public health policy. We examined this relationship for three sportfish from six lakes across North Carolina, USA. Bluegill (Lepomis macrochirus) had the lowest Hg levels and only the very largest fish in the most contaminated site exceeded the US Environmental Protection Agency (USEPA) Hg screening level. Black crappie (Pomoxis nigromaculatus) had an intermediate level of Hg and larger individuals exceeded the USEPA screening level; however, they tended not to exceed this level before reaching the harvest length limit. Largemouth bass (Micropterus salmoides) exceeded the USEPA screening level at sizes below the fishery length limit in two lakes, leaving only higher risk fish for anglers to harvest and consume. Removing the effects of fish age and trophic position, we found strong positive correlations between Hg and fish length for largemouth bass and black crappie. We suggest public health officials and wildlife managers collaborate to structure fishery regulations and length-based fish consumption advisories that protect consumers from Hg exposure and communicate the relative risk of fish consumption. PMID:23388852

Fish wariness is a more sensitive indicator to changes in fishing pressure than abundance, length or biomass.

PubMed

Goetze, Jordan S; Januchowski-Hartley, Fraser A; Claudet, Joachim; Langlois, Tim J; Wilson, Shaun K; Jupiter, Stacy D

2017-06-01

Identifying the most sensitive indicators to changes in fishing pressure is important for accurately detecting impacts. Biomass is thought to be more sensitive than abundance and length, while the wariness of fishes is emerging as a new metric. Periodically harvested closures (PHCs) that involve the opening and closing of an area to fishing are the most common form of fisheries management in the western Pacific. The opening of PHCs to fishing provides a unique opportunity to compare the sensitivity of metrics, such as abundance, length, biomass and wariness, to changes in fishing pressure. Diver-operated stereo video (stereo-DOV) provides data on fish behavior (using a proxy for wariness, minimum approach distance) simultaneous to abundance and length estimates. We assessed the impact of PHC protection and harvesting on the abundance, length, biomass, and wariness of target species using stereo-DOVs. This allowed a comparison of the sensitivity of these metrics to changes in fishing pressure across four PHCs in Fiji, where spearfishing and fish drives are common. Before PHCs were opened to fishing they consistently decreased the wariness of targeted species but were less likely to increase abundance, length, or biomass. Pulse harvesting of PHCs resulted in a rapid increase in the wariness of fishes but inconsistent impacts across the other metrics. Our results suggest that fish wariness is the most sensitive indicator of fishing pressure, followed by biomass, length, and abundance. The collection of behavioral data simultaneously with abundance, length, and biomass estimates using stereo-DOVs offers a cost-effective indicator of protection or rapid increases in fishing pressure. Stereo-DOVs can rapidly provide large amounts of behavioral data from monitoring programs historically focused on estimating abundance and length of fishes, which is not feasible with visual methods. © 2017 by the Ecological Society of America.

Novel expression of the stanniocalcin gene in fish.

PubMed

McCudden, C R; Kogon, M R; DiMattia, G E; Wagner, G F

2001-10-01

It is currently accepted that the fish stanniocalcin (STC) gene is expressed exclusively in the corpuscles of Stannius (CS), unique endocrine glands on the kidneys of bony fishes. In this study, we have re-examined the pattern of fish STC gene expression in the light of the recent evidence for widespread expression of the gene in mammals. Surprisingly, we found by Northern blotting that the fish gene was also expressed in the kidneys and gonads, in addition to the CS glands. Moreover, Southern blotting of RT-PCR products revealed STC mRNA transcripts in all tissues assayed, including brain, heart, gill, muscle and intestine. In situ hybridization studies using digoxigenin-labeled riboprobes localized STC mRNA to chondrocytes, and both mature and developing nephritic tubules. Immunocytochemical staining indicated that the STC protein was widespread in cells of the gill, kidney, brain, eye, pseudobranch and skin. We also characterized the salmon STC gene, establishing that it was comprised of five exons as opposed to four in mammals. A single transcription start site was identified by primer extension 99 bp upstream of the start codon. This is the first evidence of STC gene expression in fish tissues other than the CS glands and suggests that, as in mammals, fish STC operates via both local and endocrine pathways.

Use of a storm water retention system for conservation of regionally endangered fishes

USGS Publications Warehouse

Schaeffer, Jeffrey S.; Bland, James K.; Janssen, John

2012-01-01

Maintaining aquatic biodiversity in urban or suburban areas can be problematic because urban landscapes can be nearly devoid of aquatic habitats other than engineered basins for storm water management. These areas are usually of questionable value for fish, but we examined a case study in which five regionally imperiled fish species were reintroduced into an artificial storm water detention pond and subsequently thrived. Although not a formal experiment, postintroduction survey data suggested that three of the five species maintained high population densities for 10 years after initial stocking, and two persisted in lower numbers. Success was likely due to a combination of unique design features and prior habitat preparation that resulted in clear water conditions that supported dense vegetation. Stocked fish persisted despite occasional bouts of low dissolved oxygen and increased chloride levels resulting from road salt application within the watershed. Transplanted fish served as a source population for both research and further reintroduction experiments. We suggest that, for some fish species, habitat preservation has a middle ground between natural habitats and completely artificial environments that require constant husbandry and that storm water systems could be used to create engineered sanctuaries within the human landscape that have many potential benefits for both humans and fish.

Influence of landscape structure on reef fish assemblages

USGS Publications Warehouse

Grober-Dunsmore, R.; Frazer, T.K.; Beets, J.P.; Lindberg, W.J.; Zwick, P.; Funicelli, N.A.

2008-01-01

Management of tropical marine environments calls for interdisciplinary studies and innovative methodologies that consider processes occurring over broad spatial scales. We investigated relationships between landscape structure and reef fish assemblage structure in the US Virgin Islands. Measures of landscape structure were transformed into a reduced set of composite indices using principal component analyses (PCA) to synthesize data on the spatial patterning of the landscape structure of the study reefs. However, composite indices (e.g., habitat diversity) were not particularly informative for predicting reef fish assemblage structure. Rather, relationships were interpreted more easily when functional groups of fishes were related to individual habitat features. In particular, multiple reef fish parameters were strongly associated with reef context. Fishes responded to benthic habitat structure at multiple spatial scales, with various groups of fishes each correlated to a unique suite of variables. Accordingly, future experiments should be designed to test functional relationships based on the ecology of the organisms of interest. Our study demonstrates that landscape-scale habitat features influence reef fish communities, illustrating promise in applying a landscape ecology approach to better understand factors that structure coral reef ecosystems. Furthermore, our findings may prove useful in design of spatially-based conservation approaches such as marine protected areas (MPAs), because landscape-scale metrics may serve as proxies for areas with high species diversity and abundance within the coral reef landscape. ?? 2007 Springer Science+Business Media B.V.

Development of a multimetric index for fish assemblages in a cold tailwater in Tennessee

USGS Publications Warehouse

Ivasauskas, Tomas J.; Bettoli, Phillip William

2014-01-01

Tailwaters downstream of hypolimnetic-release hydropeaking dams exhibit a unique combination of stressors that affects the structure and function of resident fish assemblages. We developed a statistically and biologically defensible multimetric index of fish assemblages for the Caney Fork River below Center Hill Dam, Tennessee. Fish assemblages were sampled at five sites using boat-mounted and backpack electrofishing gear from fall 2009 through summer 2011. A multivariate statistical approach was used to select metrics that best reflected the downstream gradients in abiotic variables. Five metrics derived from boat electrofishing samples and four metrics derived from backpack electrofishing samples were selected for incorporation into the index based on their high correlation with environmental data. The nine metrics demonstrated predictable patterns of increase or decrease with increasing distance downstream of the dam. The multimetric index generally exhibited a pattern of increasing scores with increasing distance from the dam, indicating a downstream recovery gradient in fish assemblage composition. The index can be used to monitor anticipated changes in the fish communities of the Caney Fork River when repairs to Center Hill Dam are completed later this decade, resulting in altered dam operations.

Largest global shark biomass found in the northern Galápagos Islands of Darwin and Wolf

PubMed Central

Acuña-Marrero, David; Rastoin, Etienne; Friedlander, Alan M.; Donovan, Mary K.; Sala, Enric

2016-01-01

Overfishing has dramatically depleted sharks and other large predatory fishes worldwide except for a few remote and/or well-protected areas. The islands of Darwin and Wolf in the far north of the Galapagos Marine Reserve (GMR) are known for their large shark abundance, making them a global scuba diving and conservation hotspot. Here we report quantitative estimates of fish abundance at Darwin and Wolf over two consecutive years using stereo-video surveys, which reveal the largest reef fish biomass ever reported (17.5 t \\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{upgreek} \\usepackage{mathrsfs} \\setlength{\\oddsidemargin}{-69pt} \\begin{document} }{}${\\mathrm{ha}}^{-1}$\\end{document}ha−1 on average), consisting largely of sharks. Despite this, the abundance of reef fishes around the GMR, such as groupers, has been severely reduced because of unsustainable fishing practices. Although Darwin and Wolf are within the GMR, they were not fully protected from fishing until March 2016. Given the ecological value and the economic importance of Darwin and Wolf for the dive tourism industry, the current protection should ensure the long-term conservation of this hotspot of unique global value. PMID:27190701

Functional diversity of non-lethal effects, chemical camouflage, and variation in fish avoidance in colonizing beetles.

PubMed

Resetarits, William J; Pintar, Matthew R

2016-12-01

Predators play an extremely important role in natural communities. In freshwater systems, fish can dominate sorting both at the colonization and post-colonization stage. Specifically, for many colonizing species, fish can have non-lethal, direct effects that exceed the lethal direct effects of predation. Functionally diverse fish species with a range of predatory capabilities have previously been observed to elicit functionally equivalent responses on oviposition in tree frogs. We tested this hypothesis of functional equivalence of non-lethal effects for four predatory fish species, using naturally colonizing populations of aquatic beetles. Among taxa other than mosquitoes, and with the exception of the chemically camouflaged pirate perch, Aphredoderus sayanus, we provide the first evidence of variation in colonization or oviposition responses to different fish species. Focusing on total abundance, Fundulus chrysotus, a gape-limited, surface-feeding fish, elicited unique responses among colonizing Hydrophilidae, with the exception of the smallest and most abundant taxa, Paracymus, while Dytiscidae responded similarly to all avoided fish. Neither family responded to A. sayanus. Analysis of species richness and multivariate characterization of the beetle assemblages for the four fish species and controls revealed additional variation among the three avoided species and confirmed that chemical camouflage in A. sayanus results in assemblages essentially identical to fishless controls. The origin of this variation in beetle responses to different fish is unknown, but may involve variation in cue sensitivity, different behavioral algorithms, or differential responses to species-specific fish cues. The identity of fish species occupying aquatic habitats is crucial to understanding community structure, as varying strengths of lethal and non-lethal effects, as well as their interaction, create complex landscapes of predator effects and challenge the notion of functional equivalence. © 2016 by the Ecological Society of America.

First Report of Microfaunal Remains from Lignitic Sequences of Bhavnagar Lignite Mine (khadsaliya Formation), Gujarat, India: Implication to Depositional Environments and Age

NASA Astrophysics Data System (ADS)

Maurya, A. S.

2016-12-01

FIRST REPORT OF MICROFAUNAL REMAINS FROM LIGNITIC SEQUENCES OF BHAVNAGAR LIGNITE MINE (KHADSALIYA FORMATION), GUJARAT, INDIA: IMPLICATION TO DEPOSITIONAL ENVIRONMENTS AND AGEABHAYANAND SINGH MAURYA1*, SANJAY KUMAR VERMA1, PRAGYA PANDEY11Department of Earth Sciences, Indian Institute of Technology Roorkee, Roorkee Moderately preserved fish otoliths, fish vertebra, bivalves, pteropods, ostracods and foraminifereral remains were recovered from the grey to greenish-grey clays of Khadsaliya Formation, Bhavnagar Lignite Mine (western India) and quantitatively analyzed to understand the depositional environment. The bio-facies assemblage is diverse and dominated by fauna Fishes, Bivalve, Pteropods and with rare occurrences of Ostracoda and Foraminifera. Fish fauna includes otoliths represented by Ambassidarum, Apogonidarum, Percoideorum and Gobiidarum vastani, out of which Gobiidarum vastani is possibly representing Ypresian (early Eocene). The Globanomalina ovalis a smaller planktic foraminifer is known to be a very short ranged species corresponds to Planktic Foranimiferal Zone 5 to 6 (P5-P6) i.e late Thanetian to early Yepresian. Presence of both fresh water (Lepisosteus, Osteoglossidae), fresh water (Cypridopsis) ostracods and shallow marine fauna (Enchodus, Egertonia and Stephanodus) of fish vertebra; (Cardita) bivalve, , marine water (Globanomalina, Eggrella, Pyrulinoides) foraminifer suggests that Bhavnagar lignite mine have an assemblage of admixed fauna and rocks of Khaldsiya formation at Bhavnagar Lignite mine deposited under marine transgressive-regressive cycles. Some of the microfauna from Bhavnagar lignite mine show close affinities with microfaunal assemblages of the Vastan lignite mine of Gujarat, India which is stated to be of Ypresian (early Eocene).

Genetic Resistance to Rhabdovirus Infection in Teleost Fish Is Paralleled to the Derived Cell Resistance Status

PubMed Central

Verrier, Eloi R.; Langevin, Christelle; Tohry, Corinne; Houel, Armel; Ducrocq, Vincent; Benmansour, Abdenour; Quillet, Edwige; Boudinot, Pierre

2012-01-01

Genetic factors of resistance and predisposition to viral diseases explain a significant part of the clinical variability observed within host populations. Predisposition to viral diseases has been associated to MHC haplotypes and T cell immunity, but a growing repertoire of innate/intrinsic factors are implicated in the genetic determinism of the host susceptibility to viruses. In a long-term study of the genetics of host resistance to fish rhabdoviruses, we produced a collection of double-haploid rainbow trout clones showing a wide range of susceptibility to Viral Hemorrhagic Septicemia Virus (VHSV) waterborne infection. The susceptibility of fibroblastic cell lines derived from these clonal fish was fully consistent with the susceptibility of the parental fish clones. The mechanisms determining the host resistance therefore did not associate with specific host immunity, but rather with innate or intrinsic factors. One cell line was resistant to rhabdovirus infection due to the combination of an early interferon IFN induction - that was not observed in the susceptible cells - and of yet unknown factors that hamper the first steps of the viral cycle. The implication of IFN was well consistent with the wide range of resistance of this genetic background to VSHV and IHNV, to the birnavirus IPNV and the orthomyxovirus ISAV. Another cell line was even more refractory to the VHSV infection through different antiviral mechanisms. This collection of clonal fish and isogenic cell lines provides an interesting model to analyze the relative contribution of antiviral pathways to the resistance to different viruses. PMID:22514610

Sources and fate of antimicrobials in integrated fish-pig and non-integrated tilapia farms.

PubMed

Li, Kang; Liu, Liping; Zhan, Jia; Scippo, Marie-Louise; Hvidtfeldt, Kristian; Liu, Yuan; Dalsgaard, Anders

2017-10-01

Antimicrobial contamination in aquaculture products constitutes a food safety hazard, but little is known about the introduction and accumulation of antimicrobials in integrated fish-pig aquaculture. This study, conducted in 2013, aimed to determine the residues of 11 types of antimicrobials by UPLC-MS/MS analysis in fish feed (n=37), pig feed (n=9), pig manure (n=9), pond sediment (n=20), fish skin (n=20) and muscle tissue (n=20) sampled from integrated tilapia-pig farms, non-integrated tilapia farms and fish feed supply shops. There was a higher occurrence of antimicrobial residues in fish skin from both integrated and non-integrated farms, and in pig manure. Enrofloxacin (3.9-129.3μg/kg) and sulfadiazine (0.7-7.8μg/kg) were commonly detected in fish skin and muscle, pig manure and pond sediment from integrated farms, with different types of antimicrobials found in pig manure and tilapia samples. In non-integrated farms, sulfadiazine (2.5-89.9μg/kg) was the predominant antimicrobial detected in fish skin and muscle, fish feed and pond sediment. In general, antimicrobials seemed not to be commonly transmitted from pig to fish in tilapia-pig integrated farms, and fish feed, pig feed and pond sediment did not seem as important sources of the antimicrobials found in fish from both systems. The frequent findings of antimicrobial residues in fish skin compared with fish muscle was probably due to different pharmacokinetics in different tissue types, which have practical food safety implications since antimicrobial residues monitoring is usually performed analyzing mixed skin and fish muscle samples. Copyright © 2017 Elsevier B.V. All rights reserved.

Zebrafish AID is capable of deaminating methylated deoxycytidines

PubMed Central

Abdouni, Hala; King, Justin J.; Suliman, Mussa; Quinlan, Matthew; Fifield, Heather; Larijani, Mani

2013-01-01

Activation-induced cytidine deaminase (AID) deaminates deoxycytidine (dC) to deoxyuracil (dU) at immunoglobulin loci in B lymphocytes to mediate secondary antibody diversification. Recently, AID has been proposed to also mediate epigenetic reprogramming by demethylating methylated cytidines (mC) possibly through deamination. AID overexpression in zebrafish embryos was shown to promote genome demethylation through G:T lesions, implicating a deamination-dependent mechanism. We and others have previously shown that mC is a poor substrate for human AID. Here, we examined the ability of bony fish AID to deaminate mC. We report that zebrafish AID was unique among all orthologs in that it efficiently deaminates mC. Analysis of domain-swapped and mutant AID revealed that mC specificity is independent of the overall high-catalytic efficiency of zebrafish AID. Structural modeling with or without bound DNA suggests that efficient deamination of mC by zebrafish AID is likely not due to a larger catalytic pocket allowing for better fit of mC, but rather because of subtle differences in the flexibility of its structure. PMID:23585279

Insectivory versus piscivory in Black Terns: Implications for food provisioning and growth of chicks

USGS Publications Warehouse

Gilbert, A.T.; Servello, F.A.

2005-01-01

The Black Tern (Chlidonias niger) is known for insectivory in their breeding range, but they are piscivorous in winter and feed some fish to chicks. Fish have potentially high value for chick provisioning because of their larger mass, but the relative value of fish and insect diets for chick growth is unknown. In 1999-2000, we documented use of fish and insects for provisioning chicks at four Black Tern colonies in Maine and examined chick growth rates at two colonies (Douglas Pond and Carlton Pond) that differed in fish and insect use. Deliveries of fish and insects to broods were documented using video cameras and observations from blinds, while concurrently measuring chick growth in nest enclosures. Fish use was substantial (>25% of deliveries) at three of four colonies. Fish comprised 29% of items and 56% of metabolizable energy delivered to chicks at Douglas Pond compared to 13% of items and 22% of metabolizeable energy at Carlton Pond. Food delivery rate was inversely related to the proportion of large fish. In brood diets at Douglas and Carlton Ponds and increased with brood age at Carlton Pond only, apparently due to high insect use. Chick growth rate did not vary with respect to fish and insect composition of diets. It is concluded that adults were able to raise chicks through age 12 d at comparable growth rates with insect-or fish-dominated diets. Use of fish may be more energy efficient for adults, and the capability to use both fish and insects may reduce potential variability in food availability during the breeding season.

Effects of fish community on occurrences of Yangtze finless porpoise in confluence of the Yangtze and Wanhe Rivers.

PubMed

Zhang, Xiaoke; Yu, Daoping; Wang, Huili; Wan, An; Chen, Minmin; Tao, Feng; Song, Zunrong

2015-06-01

The Yangtze finless porpoise is a subspecies of narrow-ridged finless porpoise endemic to the middle and lower reaches of the Yangtze River and the adjoining Poyang and Dongting Lakes. With the depletion of fish stocks in the Yangtze River in recent decades, food availability has become the most important factor affecting the survival of this subspecies. Despite this, the relationships between fish community and occurrences of porpoise are far from being fully understood. Therefore, during September 2013 to August 2014, the occurrences of porpoise were investigated in confluence of the Yangtze and Wanhe Rivers; fish community was also surveyed synchronously in confluence and two adjacent transects. The results showed that (1) the confluence had maximum fish species richness, and the main dominant species was upper fish, while the other two transects were mainly dominated by demersal fish. ANOVA analyses showed that individual number and yield of upper fish which can be eaten by porpoise (upper edible fish) in the confluence were significantly higher than other two transects. (2) Average group size of the porpoise was 3.7 ± 1.8 individuals. The occurrences of porpoise in different seasons had great differences, and the porpoise was more likely to be detected in autumn and winter. (3) Fish community had significant effects on occurrences of porpoise, and the main influencing factors were fish species richness, individual number, and yield of edible fish, especially the upper edible fish. The results of this study will have important implications for the conservation of porpoise.

Anthropogenic disturbance and environmental associations with fish assemblage structure in two nonwadeable rivers

USGS Publications Warehouse

Parks, T. P.; Quist, Michael C.; Pierce, C.L.

2016-01-01

Nonwadeable rivers are unique ecosystems that support high levels of aquatic biodiversity, yet they have been greatly altered by human activities. Although riverine fish assemblages have been studied in the past, we still have an incomplete understanding of how fish assemblages respond to both natural and anthropogenic influences in large rivers. The purpose of this study was to evaluate associations between fish assemblage structure and reach-scale habitat, dam, and watershed land use characteristics. In the summers of 2011 and 2012, comprehensive fish and environmental data were collected from 33 reaches in the Iowa and Cedar rivers of eastern-central Iowa. Canonical correspondence analysis (CCA) was used to evaluate environmental relationships with species relative abundance, functional trait abundance (e.g. catch rate of tolerant species), and functional trait composition (e.g. percentage of tolerant species). On the basis of partial CCAs, reach-scale habitat, dam characteristics, and watershed land use features explained 25.0–81.1%, 6.2–25.1%, and 5.8–47.2% of fish assemblage variation, respectively. Although reach-scale, dam, and land use factors contributed to overall assemblage structure, the majority of fish assemblage variation was constrained by reach-scale habitat factors. Specifically, mean annual discharge was consistently selected in nine of the 11 CCA models and accounted for the majority of explained fish assemblage variance by reach-scale habitat. This study provides important insight on the influence of anthropogenic disturbances across multiple spatial scales on fish assemblages in large river systems.

Three decades of recurrent declines and recoveries in corals belie ongoing change in fish assemblages

NASA Astrophysics Data System (ADS)

Lamy, T.; Galzin, R.; Kulbicki, M.; Lison de Loma, T.; Claudet, J.

2016-03-01

Coral reefs are increasingly being altered by a myriad of anthropogenic activities and natural disturbances. Long-term studies offer unique opportunities to understand how multiple and recurrent disturbances can influence coral reef resilience and long-term dynamics. While the long-term dynamics of coral assemblages have been extensively documented, the long-term dynamics of coral reef fish assemblages have received less attention. Here, we describe the changes in fish assemblages on Tiahura reef, Moorea, from 1979 to 2011. During this 33-yr period, Tiahura was exposed to multiple disturbances (crown-of-thorns seastar outbreaks and cyclones) that caused recurrent declines and recoveries of coral cover and changes in the dominant coral genera. These shifts in coral composition were associated with long-term cascading effects on fish assemblages. The composition and trophic structure of fish assemblages continuously shifted without returning to their initial composition, whereas fish species richness remained stable, albeit with a small increase over time. We detected nonlinear responses of fish density when corals were most degraded. When coral cover dropped below 10 % following a severe crown-of-thorns sea star outbreak, the density of most fish trophic groups sharply decreased. Our study shows that historical contingency may potentially be an important but largely underestimated factor explaining the contemporary structure of reef fish assemblages and suggests that temporal stability in their structure and function should not necessarily be the target of management strategies that aim at increasing or maintaining coral reef resilience.

Parasitism, personality and cognition in fish.

PubMed

Barber, I; Mora, A B; Payne, E M; Weinersmith, K L; Sih, A

2017-08-01

It is well established that parasites can have profound effects on the behaviour of host organisms, and that individual differences in behaviour can influence susceptibility to parasite infections. Recently, two major themes of research have developed. First, there has been a growing interest in the proximate, mechanistic processes underpinning parasite-associated behaviour change, and the interactive roles of the neuro-, immune, and other physiological systems in determining relationships between behaviour and infection susceptibility. Secondly, as the study of behaviour has shifted away from one-off measurements of single behaviours and towards a behavioural syndromes/personality framework, research is starting to focus on the consequences of parasite infection for temporal and contextual consistency of behaviour, and on the implications of different personality types for infection susceptibility. In addition, there is increasing interest in the potential for relationships between cognition and personality to also have implications for host-parasite interactions. As models well-suited to both the laboratory study of behaviour and experimental parasitology, teleost fish have been used as hosts in many of these studies. In this review we provide a broad overview of the range of mechanisms that potentially generate links between fish behaviour, personality, and parasitism, and illustrate these using examples drawn from the recent literature. In addition, we examine the potential interactions between cognition, personality and parasitism, and identify questions that may be usefully investigated with fish models. Copyright © 2016 Elsevier B.V. All rights reserved.

Georgia fishery study: implications for dose calculations. Revision 1

DOE Office of Scientific and Technical Information (OSTI.GOV)

Turcotte, M.D.S.

Fish consumption will contribute a major portion of the estimated individual and population doses from L-Reactor liquid releases and Cs-137 remobilization in Steel Creek. It is therefore important that the values for fish consumption used in dose calculations be as realistic as possible. Since publication of the L-Reactor Environmental Information Document (EID), data have become available on sport fishing in the Savannah River. These data provide SRP with a site-specific sport fish harvest and consumption values for use in dose calculations. The Georgia fishery data support the total population fish consumption and calculated dose reported in the EID. The datamore » indicate, however, that both the EID average and maximum individual fish consumption have been underestimated, although each to a different degree. The average fish consumption value used in the EID is approximately 3% below the lower limit of the fish consumption range calculated using the Georgia data. Maximum fish consumption in the EID has been underestimated by approximately 60%, and doses to the maximum individual should also be recalculated. Future dose calculations should utilize an average adult fish consumption value of 11.3 kg/yr, and a maximum adult fish consumption value of 34 kg/yr. Consumption values for the teen and child age groups should be increased proportionally: (1) teen average = 8.5; maximum = 25.9 kg/yr; and (2) child average = 3.6; maximum = 11.2 kg/yr. 8 refs.« less

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

PubMed Central

Arend, Kristin K; Bain, Mark B

2008-01-01

Background We explored how embayment watershed inputs, morphometry, and hydrology influence fish community structure among eight embayments located along the southeastern shoreline of Lake Ontario, New York, USA. Embayments differed in surface area and depth, varied in their connections to Lake Ontario and their watersheds, and drained watersheds representing a gradient of agricultural to forested land use. Results We related various physicochemical factors, including total phosphorus load, embayment area, and submerged vegetation, to differences in fish species diversity and community relative abundance, biomass, and size structure both among and within embayments. Yellow perch (Perca flavescens) and centrarchids numerically dominated most embayment fish communities. Biomass was dominated by piscivorous fishes including brown bullhead (Ameiurus nebulosus), bowfin (Amia calva), and northern pike (Esox lucius). Phosphorus loading influenced relative biomass, but not species diversity or relative abundance. Fish relative abundance differed among embayments; within embayments, fish abundance at individual sampling stations increased significantly with submerged vegetative cover. Relative biomass differed among embayments and was positively related to total phophorus loading and embayment area. Fish community size structure, based on size spectra analysis, differed among embayments, with the frequency of smaller-bodied fishes positively related to percent vegetation. Conclusion The importance of total phosphorus loading and vegetation in structuring fish communities has implications for anthropogenic impacts to embayment fish communities through activities such as farming and residential development, reduction of cultural eutrophication, and shoreline development and maintenance. PMID:19114002

Current ecological understanding of fungal-like pathogens of fish: what lies beneath?

PubMed Central

Gozlan, Rodolphe E.; Marshall, Wyth L.; Lilje, Osu; Jessop, Casey N.; Gleason, Frank H.; Andreou, Demetra

2014-01-01

Despite increasingly sophisticated microbiological techniques, and long after the first discovery of microbes, basic knowledge is still lacking to fully appreciate the ecological importance of microbial parasites in fish. This is likely due to the nature of their habitats as many species of fish suffer from living beneath turbid water away from easy recording. However, fishes represent key ecosystem services for millions of people around the world and the absence of a functional ecological understanding of viruses, prokaryotes, and small eukaryotes in the maintenance of fish populations and of their diversity represents an inherent barrier to aquatic conservation and food security. Among recent emerging infectious diseases responsible for severe population declines in plant and animal taxa, fungal and fungal-like microbes have emerged as significant contributors. Here, we review the current knowledge gaps of fungal and fungal-like parasites and pathogens in fish and put them into an ecological perspective with direct implications for the monitoring of fungal fish pathogens in the wild, their phylogeography as well as their associated ecological impact on fish populations. With increasing fish movement around the world for farming, releases into the wild for sport fishing and human-driven habitat changes, it is expected, along with improved environmental monitoring of fungal and fungal-like infections, that the full extent of the impact of these pathogens on wild fish populations will soon emerge as a major threat to freshwater biodiversity. PMID:24600442

Modulation of thermal noise and spectral sensitivity in Lake Baikal cottoid fish rhodopsins.

PubMed

Luk, Hoi Ling; Bhattacharyya, Nihar; Montisci, Fabio; Morrow, James M; Melaccio, Federico; Wada, Akimori; Sheves, Mudi; Fanelli, Francesca; Chang, Belinda S W; Olivucci, Massimo

2016-12-09

Lake Baikal is the deepest and one of the most ancient lakes in the world. Its unique ecology has resulted in the colonization of a diversity of depth habitats by a unique fauna that includes a group of teleost fish of the sub-order Cottoidei. This relatively recent radiation of cottoid fishes shows a gradual blue-shift in the wavelength of the absorption maximum of their visual pigments with increasing habitat depth. Here we combine homology modeling and quantum chemical calculations with experimental in vitro measurements of rhodopsins to investigate dim-light adaptation. The calculations, which were able to reproduce the trend of observed absorption maxima in both A1 and A2 rhodopsins, reveal a Barlow-type relationship between the absorption maxima and the thermal isomerization rate suggesting a link between the observed blue-shift and a thermal noise decrease. A Nakanishi point-charge analysis of the electrostatic effects of non-conserved and conserved amino acid residues surrounding the rhodopsin chromophore identified both close and distant sites affecting simultaneously spectral tuning and visual sensitivity. We propose that natural variation at these sites modulate both the thermal noise and spectral shifting in Baikal cottoid visual pigments resulting in adaptations that enable vision in deep water light environments.

Modulation of thermal noise and spectral sensitivity in Lake Baikal cottoid fish rhodopsins

NASA Astrophysics Data System (ADS)

Luk, Hoi Ling; Bhattacharyya, Nihar; Montisci, Fabio; Morrow, James M.; Melaccio, Federico; Wada, Akimori; Sheves, Mudi; Fanelli, Francesca; Chang, Belinda S. W.; Olivucci, Massimo

2016-12-01

Lake Baikal is the deepest and one of the most ancient lakes in the world. Its unique ecology has resulted in the colonization of a diversity of depth habitats by a unique fauna that includes a group of teleost fish of the sub-order Cottoidei. This relatively recent radiation of cottoid fishes shows a gradual blue-shift in the wavelength of the absorption maximum of their visual pigments with increasing habitat depth. Here we combine homology modeling and quantum chemical calculations with experimental in vitro measurements of rhodopsins to investigate dim-light adaptation. The calculations, which were able to reproduce the trend of observed absorption maxima in both A1 and A2 rhodopsins, reveal a Barlow-type relationship between the absorption maxima and the thermal isomerization rate suggesting a link between the observed blue-shift and a thermal noise decrease. A Nakanishi point-charge analysis of the electrostatic effects of non-conserved and conserved amino acid residues surrounding the rhodopsin chromophore identified both close and distant sites affecting simultaneously spectral tuning and visual sensitivity. We propose that natural variation at these sites modulate both the thermal noise and spectral shifting in Baikal cottoid visual pigments resulting in adaptations that enable vision in deep water light environments.

The adaptation of polar fishes to climatic changes: Structure, function and phylogeny of haemoglobin.

PubMed

Verde, Cinzia; Giordano, Daniela; di Prisco, Guido

2008-01-01

In the Antarctic, fishes of dominant suborder Notothenioidei have evolved in a unique thermal scenario. Phylogenetically related taxa of the suborder live in a wide range of latitudes, in Antarctic, sub-Antarctic and temperate oceans. Consequently, they offer a remarkable opportunity to study the physiological and biochemical characters gained and, conversely, lost during their evolutionary history. The evolutionary perspective has also been pursued by comparative studies of some features of the heme protein devoted to O(2) transport in fish living in the other polar region, the Arctic. The two polar regions differ by age and isolation. Fish living in each habitat have undergone regional constraints and fit into different evolutionary histories. The aim of this contribution is to survey the current knowledge of molecular structure, functional features, phylogeny and adaptations of the haemoglobins of fish thriving in the Antarctic, sub-Antarctic and Arctic regions (with some excursions in the temperate latitudes), in search of insights into the convergent processes evolved in response to cooling. Current climate change may disturb adaptation, calling for strategies aimed at neutralising threats to biodiversity.

Seasonal distribution and abundance of fishes and decapod crustaceans in a Cape Cod estuary

USGS Publications Warehouse

Able, K.W.; Fahay, M.P.; Heck, K.L.; Roman, C.T.; Lazzari, M.A.; Kaiser, S.C.

2002-01-01

Sampling in several habitat types (sand/mud, eelgrass, sand, gravel, macroalgae/mud) during all seasons with a variety of gears in Nauset Marsh, Massachusetts during 1985-1987 found a fauna consisting of 35 fish and 10 decapod crustacean species. Although most of the abundant species were found in several habitat types, species richness and habitat use appeared to be highest for vegetated habitats (eelgrass, macroalgae). The fishes and decapods were numerically dominated by cold-water taxa; however, numerous fish species, represented by rare individuals of predominantly southern forms, enriched the fauna. Species composition of Nauset Marsh could be distinguished from estuaries south of Cape Cod and even from the south shore of the cape. Both fishes and decapods were most abundant during the summer, apparently due to the contributions from spring and summer spawning in the estuary and the adjacent Atlantic Ocean. The location of Nauset Marsh and other estuaries on Cape Cod provide a unique opportunity to evaluate the importance of this region as a faunal boundary to estuarine species.

Life history trade-offs and community dynamics of small fishes in a seasonally pulsed wetland

USGS Publications Warehouse

DeAngelis, D.L.; Trexler, J.C.; Loftus, W.F.

2005-01-01

We used a one-dimensional, spatially explicit model to simulate the community of small fishes in the freshwater wetlands of southern Florida, USA. The seasonality of rainfall in these wetlands causes annual fluctuations in the amount of flooded area. We modeled fish populations that differed from each other only in efficiency of resource utilization and dispersal ability. The simulations showed that these trade-offs, along with the spatial and temporal variability of the environment, allow coexistence of several species competing exploitatively for a common resource type. This mechanism, while sharing some characteristics with other mechanisms proposed for coexistence of competing species, is novel in detail. Simulated fish densities resembled patterns observed in Everglades empirical data. Cells with hydroperiods less than 6 months accumulated negligible fish biomass. One unique model result was that, when multiple species coexisted, it was possible for one of the coexisting species to have both lower local resource utilization efficiency and lower dispersal ability than one of the other species. This counterintuitive result is a consequence of stronger effects of other competitors on the superior species. ?? 2005 NRC.

Mercury in fish and macroinvertebrates from New York's streams and rivers: A compendium of data sources

USGS Publications Warehouse

Riva-Murray, Karen; Burns, Douglas A.

2016-01-01

The U.S. Geological Survey has compiled a list of existing data sets, from selected sources, containing mercury (Hg) concentration data in fish and macroinvertebrate samples that were collected from flowing waters of New York State from 1970 through 2014. Data sets selected for inclusion in this report were limited to those that contain fish and (or) macroinvertebrate data that were collected across broad areas, cover relatively long time periods, and (or) were collected as part of a broader-scale (e.g. national) study or program. In addition, all data sets listed were collected, processed, and analyzed with documented methods, and contain critical sample information (e.g. fish species, fish size, Hg species) that is needed to analyze and interpret the reported Hg concentration data. Fourteen data sets, all from state or federal agencies, are listed in this report, along with selected descriptive information regarding each data source and data set contents. Together, these 14 data sets contain Hg and related data for more than 7,000 biological samples collected from more than 700 unique stream and river locations between 1970 and 2014.

Conflicts between sensory performance and locomotion in weakly electric fish

NASA Astrophysics Data System (ADS)

Maciver, Malcolm; Shirgaonkar, Anup; Patankar, Neelesh

2008-11-01

The knifefish Apteronotus albifrons hunts for small water insects at night using a self-generated electric field to perceive its world. Using this unique sensory adaptation, the fish senses prey that are near its body with a detection volume that approximates a cylinder that has a length ten times its radius, similar to the fish's elongated body plan. If the fish swims straight, then the back portion of the actively generated detection volume is scanning fluid already scanned by the front portion, but the energy expended to overcome drag is minimized. If it swims with the body pitched, then the rate of volume scanned for prey is increased, but the energy needed to overcome body drag is also increased. In this work we examine the compromise the fish makes between minimizing energy in overcoming drag and maximizing scan rate. We use computational fluid dynamics simulations to assess the impact of changes in body pitch angle on drag, and computational neuroscience simulations to assess the shape and size of the prey detection volume and how body angle changes the scan volume rate.

Relationships between structural complexity, coral traits, and reef fish assemblages

NASA Astrophysics Data System (ADS)

Darling, Emily S.; Graham, Nicholas A. J.; Januchowski-Hartley, Fraser A.; Nash, Kirsty L.; Pratchett, Morgan S.; Wilson, Shaun K.

2017-06-01

With the ongoing loss of coral cover and the associated flattening of reef architecture, understanding the links between coral habitat and reef fishes is of critical importance. Here, we investigate whether considering coral traits and functional diversity provides new insights into the relationship between structural complexity and reef fish communities, and whether coral traits and community composition can predict structural complexity. Across 157 sites in Seychelles, Maldives, the Chagos Archipelago, and Australia's Great Barrier Reef, we find that structural complexity and reef zone are the strongest and most consistent predictors of reef fish abundance, biomass, species richness, and trophic structure. However, coral traits, diversity, and life histories provided additional predictive power for models of reef fish assemblages, and were key drivers of structural complexity. Our findings highlight that reef complexity relies on living corals—with different traits and life histories—continuing to build carbonate skeletons, and that these nuanced relationships between coral assemblages and habitat complexity can affect the structure of reef fish assemblages. Seascape-level estimates of structural complexity are rapid and cost effective with important implications for the structure and function of fish assemblages, and should be incorporated into monitoring programs.

Dietary intake of heavy metals from eight highly consumed species of cultured fish and possible human health risk implications in Bangladesh.

PubMed

Ullah, A K M Atique; Maksud, M A; Khan, S R; Lutfa, L N; Quraishi, Shamshad B

2017-01-01

Concentrations of five heavy metals (Pb, Cd, Cr, As and Hg) in eight highly consumed cultured fish species ( Labeo rohita, Clarias gariepinus, Hypophthalmichthys molitrix, Cyprinus capio, Puntius sarana, Oreochromis mossambicus, Pangasius pangasius and Anabas testudineus ) collected from four wholesale markets of Dhaka city, Bangladesh (Karwan Bazar, Mohammadpur Town Hall, Newmarket and Mirpur-1) were measured using atomic absorption spectrometry (AAS) in order to evaluate the potential human health risks from the consumption of fish. The estimated daily intake (EDI) of all the studied heavy metals calculated on the basis of mean fish consumption of 49.5 g person -1 d -1 by Bangladeshi households indicated that no risk to people's health with respect to the EDI of investigated heavy metals through the consumption of the fish samples. From the human health point of view, the estimation of non-carcinogenic risk indicated that intake of individual heavy metal through the consumption of fish was safe for human health, whereas, consumption of combined heavy metals suggested potential health risk to highly exposed consumers. However, the estimation of carcinogenic risk of arsenic due to the consumption of fish indicated that consumers remain at risk of cancer.

Global fishmeal and fish-oil supply: inputs, outputs and markets.

PubMed

Shepherd, C J; Jackson, A J

2013-10-01

Recent data on fishmeal and fish-oil supply are presented identifying key producer countries and raw material sources and distinguishing between whole fish and by-products. The conversion of these raw materials into marine ingredients is discussed and global volumes presented. This is followed by a summary of the main countries using these marine ingredients over recent years. Uses of fishmeal and fish-oil by market segment are then presented. From this, a global mass balance of inputs and outputs is derived which allows the calculation of the input-to-output ratios (fish in:fish out; FIFO) for the main aquaculture production types to be made. Current areas of focus by the industry include the need to demonstrate sustainable practice, more strategic use of marine ingredients, greater use of fishery and land-animal by-products as well as vegetable substitutes, and novel sources of essential omega-3 fats, notably the long-chain polyunsaturated fatty acids, eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids. Implications are drawn for future supply prospects of fishmeal and fish-oil and their future role in aquaculture, agriculture and human health. © 2013 The Fisheries Society of the British Isles.

Behavioural responses to human-induced change: Why fishing should not be ignored.

PubMed

Diaz Pauli, Beatriz; Sih, Andrew

2017-03-01

Change in behaviour is usually the first response to human-induced environmental change and key for determining whether a species adapts to environmental change or becomes maladapted. Thus, understanding the behavioural response to human-induced changes is crucial in the interplay between ecology, evolution, conservation and management. Yet the behavioural response to fishing activities has been largely ignored. We review studies contrasting how fish behaviour affects catch by passive (e.g., long lines, angling) versus active gears (e.g., trawls, seines). We show that fishing not only targets certain behaviours, but it leads to a multitrait response including behavioural, physiological and life-history traits with population, community and ecosystem consequences. Fisheries-driven change (plastic or evolutionary) of fish behaviour and its correlated traits could impact fish populations well beyond their survival per se , affecting predation risk, foraging behaviour, dispersal, parental care, etc., and hence numerous ecological issues including population dynamics and trophic cascades . In particular, we discuss implications of behavioural responses to fishing for fisheries management and population resilience. More research on these topics, however, is needed to draw general conclusions, and we suggest fruitful directions for future studies.

Jaboya vs. jakambi: Status, negotiation, and HIV risks among female migrants in the "sex for fish" economy in Nyanza Province, Kenya.

PubMed

Camlin, Carol S; Kwena, Zachary A; Dworkin, Shari L

2013-06-01

In Nyanza Province, Kenya, HIV incidence is highest (26.2%) in the beach communities along Lake Victoria. Prior research documented high mobility and HIV risks among fishermen; mobility patterns and HIV risks faced by women in fishing communities are less well researched. This study aimed to characterize forms of mobility among women in the fish trade in Nyanza; describe the spatial and social features of beaches; and assess characteristics of the "sex-for-fish" economy and its implications for HIV prevention. We used qualitative methods, including participant observation in 6 beach villages and other key destinations in the Kisumu area of Nyanza that attract female migrants, and we recruited individuals for in-depth semi-structured interviews at those destinations. We interviewed 40 women, of whom 18 were fish traders, and 15 men, of whom 7 were fishermen. Data were analyzed using Atlas.ti software. We found that female fish traders are often migrants to beaches; they are also highly mobile. They are at high risk of HIV acquisition and transmission via their exchange of sex for fish with jaboya fishermen.

Mercury and methylmercury in reservoirs in Indiana

USGS Publications Warehouse

Risch, Martin R.; Fredericksen, Amanda L.

2015-01-01

Methylmercury (reported as Hg) in fish-tissue samples collected for the State fish consumption advisory program was used to describe MeHg food-web accumulation and magnification in the reservoirs. The highest percentages of fish-tissue samples with Hg concentrations that exceeded the criterion of 0.30 milligram per kilogram for protection of human health were from Monroe Lake (38 percent) and Patoka Lake (33 percent). A review of the number and size of fish species caught from these two reservoirs resulted in two implications for fish consumption by humans. First, the highest numbers of fish harvested for potential human consumption were species more likely to have MeHg concentrations lower than the human-health criterion (crappie, bluegill, and catfish). Second, although largemouth bass were likely to have MeHg concentrations higher than the human-health criterion, they were caught and released more often than they were harvested. However, the average size largemouth bass (in both reservoirs) and above-average size walleye (in Monroe Lake) that were harvested for potential human consumption were likely to have MeHg concentrations higher than the human-health criterion.

Distinguishing centrarchid genera by use of lateral line scales

USGS Publications Warehouse

Roberts, N.M.; Rabeni, C.F.; Stanovick, J.S.

2007-01-01

Predator-prey relations involving fishes are often evaluated using scales remaining in gut contents or feces. While several reliable keys help identify North American freshwater fish scales to the family level, none attempt to separate the family Centrarchidae to the genus level. Centrarchidae is of particular concern in the midwestern United States because it contains several popular sport fishes, such as smallmouth bass Micropterus dolomieu, largemouth bass M. salmoides, and rock bass Ambloplites rupestris, as well as less-sought-after species of sunfishes Lepomis spp. and crappies Pomoxis spp. Differentiating sport fish from non-sport fish has important management implications. Morphological characteristics of lateral line scales (n = 1,581) from known centrarchid fishes were analyzed. The variability of measurements within and between genera was examined to select variables that were the most useful in further classifying unknown centrarchid scales. A linear discriminant analysis model was developed using 10 variables. Based on this model, 84.4% of Ambloplites scales, 81.2% of Lepomis scales, and 86.6% of Micropterus scales were classified correctly using a jackknife procedure. ?? Copyright by the American Fisheries Society 2007.

Toxicogenomic analysis of the hepatic effects of perfluorooctanoic acid on rare minnows (Gobiocypris rarus)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wei Yanhong; Graduate School of the Chinese Academy of Sciences, Beijing, 100080; Liu Yang

2008-02-01

Perfluorooctanoic acid (PFOA) is a ubiquitous environmental contaminant that has been detected in a variety of terrestrial and aquatic organisms. To assess the effects of PFOA in fish and predict its potential mode of action, a toxicogenomic approach was applied to hepatic gene expression profile analysis in male and female rare minnows (Gobiocypris rarus) using a custom cDNA microarray containing 1773 unique genes. Rare minnows were treated with continuous flow-through exposure to PFOA at concentrations of 3, 10, and 30 mg/L for 28 days. Based on the observed histopathological changes, the livers from fish exposed to 10 mg/L PFOA weremore » selected for further hepatic gene expression analysis. While 124 and 171 genes were significantly altered by PFOA in males and females, respectively, of which 43 genes were commonly regulated in both sexes. The affected genes are involved in multiple biological processes, including lipid metabolism and transport, hormone action, immune responses, and mitochondrial functions. PFOA exposure significantly suppressed genes involved in fatty acid biosynthesis and transport but induced genes associated with intracellular trafficking of cholesterol. Alterations in expression of genes associated with mitochondrial fatty acid {beta}-oxidation were only observed in female rare minnows. In addition, PFOA inhibited genes responsible for thyroid hormone biosynthesis and significantly induced estrogen-responsive genes. These findings implicate PFOA in endocrine disruption. This work contributes not only to the elucidation of the potential mode of toxicity of PFOA to aquatic organisms but also to the use of toxicogenomic approaches to address issues in environmental toxicology.« less

MARINE LEECH ANTICOAGULANT DIVERSITY AND EVOLUTION.

PubMed

Tessler, Michael; Marancik, David; Champagne, Donald; Dove, Alistair; Camus, Alvin; Siddall, Mark E; Kvist, Sebastian

2018-03-16

Leeches (Annelida: Hirudinea) possess powerful salivary anticoagulants and, accordingly, are frequently employed in modern, authoritative medicine. Members of the almost exclusively marine family Piscicolidae account for 20% of leech species diversity, and feed on host groups (e.g., sharks) not encountered by their freshwater and terrestrial counterparts. Moreover, some species of Ozobranchidae feed on endangered marine turtles and have been implicated as potential vectors for the tumor-associated turtle herpesvirus. In spite of their ecological importance and unique host associations, there is a distinct paucity of data regarding the salivary transcriptomes of either of these families. Using next generation sequencing, we profiled transcribed, putative anticoagulants and other salivary bioactive compounds that have previously been linked to bloodfeeding from 7 piscicolid species (3 elasmobranch-feeders; 4 non-cartilaginous fish-feeders) and 1 ozobranchid species (2 samples). In total, 149 putative anticoagulants and bioactive loci were discovered in varying constellations throughout the different samples. The putative anticoagulants showed a broad spectrum of described antagonistic pathways, such as inhibition of factor Xa and platelet aggregation, that likely have similar bioactive roles in marine fish and turtles. A transcript with homology to ohanin, originally isolated from king cobras, was found in Cystobranchus vividus but is otherwise unknown from leeches. Estimation of selection pressures for the putative anticoagulants recovered evidence for both positive and purifying selection along several isolated branches in the gene trees and positive selection was also estimated for a few select codons in a variety of marine species. Similarly, phylogenetic analyses of the amino acid sequences for several anticoagulants indicated divergent evolution.

Can personality predict individual differences in brook trout spatial learning ability?

PubMed

White, S L; Wagner, T; Gowan, C; Braithwaite, V A

2017-08-01

While differences in individual personality are common in animal populations, understanding the ecological significance of variation has not yet been resolved. Evidence suggests that personality may influence learning and memory; a finding that could improve our understanding of the evolutionary processes that produce and maintain intraspecific behavioural heterogeneity. Here, we tested whether boldness, the most studied personality trait in fish, could predict learning ability in brook trout. After quantifying boldness, fish were trained to find a hidden food patch in a maze environment. Stable landmark cues were provided to indicate the location of food and, at the conclusion of training, cues were rearranged to test for learning. There was a negative relationship between boldness and learning as shy fish were increasingly more successful at navigating the maze and locating food during training trials compared to bold fish. In the altered testing environment, only shy fish continued using cues to search for food. Overall, the learning rate of bold fish was found to be lower than that of shy fish for several metrics suggesting that personality could have widespread effects on behaviour. Because learning can increase plasticity to environmental change, these results have significant implications for fish conservation. Copyright © 2016 Elsevier B.V. All rights reserved.

Behavior and movement of formerly landlocked juvenile coho salmon after release into the free-flowing Cowlitz River, Washington

USGS Publications Warehouse

Kock, Tobias J.; Henning, Julie A.; Liedtke, Theresa L.; Royer, Ida M.; Ekstrom, Brian K.; Rondorf, Dennis W.

2011-01-01

Formerly landlocked Coho Salmon (Oncorhynchus kisutch) juveniles (age 2) were monitored following release into the free-flowing Cowlitz River to determine if they remained in the river or resumed seaward migration. Juvenile Coho Salmon were tagged with a radio transmitter (30 fish) or Floy tag (1050 fish) and their behavior was monitored in the lower Cowlitz River. We found that 97% of the radio-tagged fish remained in the Cowlitz River beyond the juvenile outmigration period, and the number of fish dispersing downstream decreased with increasing distance from the release site. None of the tagged fish returned as spawning adults in the 2 y following release. We suspect that fish in our study failed to migrate because they exceeded a threshold in size, age, or physiological status. Tagged fish in our study primarily remained in the Cowlitz River, thus it is possible that these fish presented challenges to juvenile salmon migrating through the system either directly by predation or indirectly by competition for food or habitat. Given these findings, returning formerly landlocked Coho Salmon juveniles to the free-flowing river apparently provided no benefit to the anadromous population. These findings have management implications in locations where landlocked salmon have the potential to interact with anadromous species of concern.

Seasonal variation of Opisthorchis viverrini infection in cyprinoid fish in north-east Thailand: implications for parasite control and food safety.

PubMed

Sithithaworn, P; Pipitgool, V; Srisawangwong, T; Elkins, D B; Haswell-Elkins, M R

1997-01-01

Reported is the seasonal pattern of Opisthorchis viverrini metacercariae in cyprinoid fish in north-east Thailand. Samples of fish were collected in 1991-92 at monthly intervals from two areas-Khon Kaen Province, where the opisthorchiasis transmission rate was high, and Mahasarakham Province, where the rate was low. Metacercarial loads in both study areas had similar seasonal patterns. High burdens occurred in the late rainy season and winter (July to January) with low burdens during the summer (March to June). The average burden for Puntius leiacanthus in Khon Kaen was 1.68 metacercariae per fish (127.43 per kg), higher than for all species of cyprinoid fish from the low transmission area. The intensities of infection among P. leiacanthus and Cyclocheilichthys armatus collected in Mahasarakham were comparable, but lower than the intensity of Hampala dispar (0.75 metacercariae per fish) concurrently sampled from the same area (P < 0.05). There was no significant difference in metacercarial load per kg between fish species from Mahasarakham. The results indicate that seasonal variation in metacercariae was a common phenomenon in areas with both high and low endemicity of infection. Also, the metacerarial load in fish was positively associated with infection levels among humans.

Fisheries impacts on China's coastal ecosystems: Unmasking a pervasive 'fishing down' effect.

PubMed

Liang, Cui; Pauly, Daniel

2017-01-01

Intensive fishing can strongly impact marine ecosystems; among other things, it usually causes the mean trophic level of the catches to decline, an indicator of the occurrence of the 'fishing down' (FD) phenomenon. Although FD occurs throughout the world oceans, it can easily be masked by diverse factors, which has misled authors as to its generality. In this contribution, which uses the East China Sea as an example, we explore the masking effect on FD of the taxonomic coarseness of catch data, of assuming that individual sizes remain constant after intensive fishing, and the geographic expansion of fisheries. The result showed that all of these masking factors occur in the East China Sea, where only a few species are reported separately and the bulk of the catch is pooled into non-informative 'mixed fishes'. Also, the small mesh sizes and intensive fishing have reduced the sizes of fish and their trophic levels, while the fisheries have expanded offshore. Overall, taking the masking factors into account, the fishing down effect, i.e., the decline of the mean trophic level of the catch between 1979 and 2014 is in the order of 0.15 TL per decade, i.e., one of the highest estimates of FD in the world. Some ecological implications are presented.

Food protein-induced enterocolitis syndrome caused by fish and/or shellfish in Italy.

PubMed

Miceli Sopo, Stefano; Monaco, Serena; Badina, Laura; Barni, Simona; Longo, Giorgio; Novembre, Elio; Viola, Serena; Monti, Giovanna

2015-12-01

The study describes the demographic features, culprit foods, clinical features and outcomes for children presenting with acute fish and/or shellfish food protein-induced enterocolitis syndrome (FPIES) in four Italian paediatric allergy centres. A retrospective/prospective study was undertaken. All children diagnosed with fish or shellfish FPIES were enrolled. The diagnosis of FPIES was based on Sicherer's or Miceli Sopo clinical criteria. Skin prick tests (SPT) were performed in all patients, at the time of diagnosis and prior to OFC. Seventy children were enrolled. Mean age at first episode was 14 months (range 6-46 months); mean age at diagnosis was 34 months (range 6-164 months). Sole and cod were the fish most commonly implicated. Fifty-seven of 70 (81%) children had FPIES exclusively to fish, 37 of 57 (65%) children had single-fish FPIES, 20 of 57 (35%) multiple-fish FPIES, nine of 70 (13%) presented adverse reactions exclusively to shellfish, and four of 70 (6%) presented adverse reactions to both fish and shellfish. Only four (5.7%) children presented episodes of acute FPIES with different foods (2 to cow's milk, 1 to egg, 1 to beef); in all cases, onset was prior to that of fish or shellfish FPIES. Fifteen of 70 (21%) children tolerated fish other than the offending fish. Twenty-four of 70 (34%) children achieved tolerance (age range 24-102 months). The chief peculiarities of acute fish and shellfish FPIES, compared to more frequent cow's milk or soy FPIES, are (i) later age of onset, (ii) longer persistence and (iii) possibility of tolerating fish other than the offending fish. Adverse reactions with shellfish are possible. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Shark Detectives

ERIC Educational Resources Information Center

Hitt, Dia

2005-01-01

Oceans are often considered mysterious, fascinating places filled with unique and scary animals. One of the most misunderstood and therefore scariest animals is the shark, yet the whale shark, the world's largest fish, is considered harmless to humans. This student-directed activity involves research, deductive reasoning, and students' own…

Facial Recognition in a Discus Fish (Cichlidae): Experimental Approach Using Digital Models

PubMed Central

Satoh, Shun; Tanaka, Hirokazu; Kohda, Masanori

2016-01-01

A number of mammals and birds are known to be capable of visually discriminating between familiar and unfamiliar individuals, depending on facial patterns in some species. Many fish also visually recognize other conspecifics individually, and previous studies report that facial color patterns can be an initial signal for individual recognition. For example, a cichlid fish and a damselfish will use individual-specific color patterns that develop only in the facial area. However, it remains to be determined whether the facial area is an especially favorable site for visual signals in fish, and if so why? The monogamous discus fish, Symphysopdon aequifasciatus (Cichlidae), is capable of visually distinguishing its pair-partner from other conspecifics. Discus fish have individual-specific coloration patterns on entire body including the facial area, frontal head, trunk and vertical fins. If the facial area is an inherently important site for the visual cues, this species will use facial patterns for individual recognition, but otherwise they will use patterns on other body parts as well. We used modified digital models to examine whether discus fish use only facial coloration for individual recognition. Digital models of four different combinations of familiar and unfamiliar fish faces and bodies were displayed in frontal and lateral views. Focal fish frequently performed partner-specific displays towards partner-face models, and did aggressive displays towards models of non-partner’s faces. We conclude that to identify individuals this fish does not depend on frontal color patterns but does on lateral facial color patterns, although they have unique color patterns on the other parts of body. We discuss the significance of facial coloration for individual recognition in fish compared with birds and mammals. PMID:27191162

Facial Recognition in a Discus Fish (Cichlidae): Experimental Approach Using Digital Models.

PubMed

Satoh, Shun; Tanaka, Hirokazu; Kohda, Masanori

2016-01-01

A number of mammals and birds are known to be capable of visually discriminating between familiar and unfamiliar individuals, depending on facial patterns in some species. Many fish also visually recognize other conspecifics individually, and previous studies report that facial color patterns can be an initial signal for individual recognition. For example, a cichlid fish and a damselfish will use individual-specific color patterns that develop only in the facial area. However, it remains to be determined whether the facial area is an especially favorable site for visual signals in fish, and if so why? The monogamous discus fish, Symphysopdon aequifasciatus (Cichlidae), is capable of visually distinguishing its pair-partner from other conspecifics. Discus fish have individual-specific coloration patterns on entire body including the facial area, frontal head, trunk and vertical fins. If the facial area is an inherently important site for the visual cues, this species will use facial patterns for individual recognition, but otherwise they will use patterns on other body parts as well. We used modified digital models to examine whether discus fish use only facial coloration for individual recognition. Digital models of four different combinations of familiar and unfamiliar fish faces and bodies were displayed in frontal and lateral views. Focal fish frequently performed partner-specific displays towards partner-face models, and did aggressive displays towards models of non-partner's faces. We conclude that to identify individuals this fish does not depend on frontal color patterns but does on lateral facial color patterns, although they have unique color patterns on the other parts of body. We discuss the significance of facial coloration for individual recognition in fish compared with birds and mammals.

Fish Karyome version 2.1: a chromosome database of fishes and other aquatic organisms

PubMed Central

Nagpure, Naresh Sahebrao; Pathak, Ajey Kumar; Pati, Rameshwar; Rashid, Iliyas; Sharma, Jyoti; Singh, Shri Prakash; Singh, Mahender; Sarkar, Uttam Kumar; Kushwaha, Basdeo; Kumar, Ravindra; Murali, S.

2016-01-01

A voluminous information is available on karyological studies of fishes; however, limited efforts were made for compilation and curation of the available karyological data in a digital form. ‘Fish Karyome’ database was the preliminary attempt to compile and digitize the available karyological information on finfishes belonging to the Indian subcontinent. But the database had limitations since it covered data only on Indian finfishes with limited search options. Perceiving the feedbacks from the users and its utility in fish cytogenetic studies, the Fish Karyome database was upgraded by applying Linux, Apache, MySQL and PHP (pre hypertext processor) (LAMP) technologies. In the present version, the scope of the system was increased by compiling and curating the available chromosomal information over the globe on fishes and other aquatic organisms, such as echinoderms, molluscs and arthropods, especially of aquaculture importance. Thus, Fish Karyome version 2.1 presently covers 866 chromosomal records for 726 species supported with 253 published articles and the information is being updated regularly. The database provides information on chromosome number and morphology, sex chromosomes, chromosome banding, molecular cytogenetic markers, etc. supported by fish and karyotype images through interactive tools. It also enables the users to browse and view chromosomal information based on habitat, family, conservation status and chromosome number. The system also displays chromosome number in model organisms, protocol for chromosome preparation and allied techniques and glossary of cytogenetic terms. A data submission facility has also been provided through data submission panel. The database can serve as a unique and useful resource for cytogenetic characterization, sex determination, chromosomal mapping, cytotaxonomy, karyo-evolution and systematics of fishes. Database URL: http://mail.nbfgr.res.in/Fish_Karyome PMID:26980518

Fish Karyome version 2.1: a chromosome database of fishes and other aquatic organisms.

PubMed

Nagpure, Naresh Sahebrao; Pathak, Ajey Kumar; Pati, Rameshwar; Rashid, Iliyas; Sharma, Jyoti; Singh, Shri Prakash; Singh, Mahender; Sarkar, Uttam Kumar; Kushwaha, Basdeo; Kumar, Ravindra; Murali, S

2016-01-01

A voluminous information is available on karyological studies of fishes; however, limited efforts were made for compilation and curation of the available karyological data in a digital form. 'Fish Karyome' database was the preliminary attempt to compile and digitize the available karyological information on finfishes belonging to the Indian subcontinent. But the database had limitations since it covered data only on Indian finfishes with limited search options. Perceiving the feedbacks from the users and its utility in fish cytogenetic studies, the Fish Karyome database was upgraded by applying Linux, Apache, MySQL and PHP (pre hypertext processor) (LAMP) technologies. In the present version, the scope of the system was increased by compiling and curating the available chromosomal information over the globe on fishes and other aquatic organisms, such as echinoderms, molluscs and arthropods, especially of aquaculture importance. Thus, Fish Karyome version 2.1 presently covers 866 chromosomal records for 726 species supported with 253 published articles and the information is being updated regularly. The database provides information on chromosome number and morphology, sex chromosomes, chromosome banding, molecular cytogenetic markers, etc. supported by fish and karyotype images through interactive tools. It also enables the users to browse and view chromosomal information based on habitat, family, conservation status and chromosome number. The system also displays chromosome number in model organisms, protocol for chromosome preparation and allied techniques and glossary of cytogenetic terms. A data submission facility has also been provided through data submission panel. The database can serve as a unique and useful resource for cytogenetic characterization, sex determination, chromosomal mapping, cytotaxonomy, karyo-evolution and systematics of fishes. Database URL: http://mail.nbfgr.res.in/Fish_Karyome. © The Author(s) 2016. Published by Oxford University Press.

Coal: special report number 2

USGS Publications Warehouse

Keenlyne, Kent D.

1977-01-01

The Fish and Wildlife Service has extensive biological expertise within the Department of Interior and exerts national leadership in the management and protection of the nation's fish and wildlife resources, their habitat, and environment. Specifically, the Office of Biological Services obtains and assimilates biological and environmental data and identifies additional informational needs and means to provide environmental and biological input into major natural resource decisions. Coal Coordinators assist in carrying out Fish and Wildlife Service involvement in the Interior Department Coal Leasing Program through a multi-stage process designed to assemble existing fish and wildlife inventory data and to prioritize fish and wildlife values in areas subject to coal leasing and associated development. This report is designed to identify possible areas of concern for wildlife and its habitat in Wyoming in the development of coal and the associate implication of land use changes. This report summarizes past and present development of the coal resource in Wyoming in anticipation of future identification of data needs for making sound resource decisions in the development of coal.

Predation Risk within Fishing Gear and Implications for South Australian Rock Lobster Fisheries.

PubMed

Briceño, Felipe; Linnane, Adrian Joseph; Quiroz, Juan Carlos; Gardner, Caleb; Pecl, Gretta Tatyana

2015-01-01

Depredation of southern rock lobster (Jasus edwardsii) within fishing gear by the Maori octopus (Pinnoctopus cordiformis) has economic and ecological impacts on valuable fisheries in South Australia. In addition, depredation rates can be highly variable resulting in uncertainties for the fishery. We examined how in-pot lobster predation was influenced by factors such as lobster size and sex, season, fishing zone, and catch rate. Using mixed modelling techniques, we found that in-pot predation risk increased with lobster size and was higher for male lobsters. In addition, the effect of catch rate of lobsters on predation risk by octopus differed among fishing zones. There was both a seasonal and a spatial component to octopus predation, with an increased risk within discrete fishing grounds in South Australia at certain times of the year. Information about predation within lobster gear can assist fishery management decision-making, potentially leading to significant reduction in economic losses to the fishery.

Laterality Influences Schooling Position in Rainbowfish, Melanotaenia spp

PubMed Central

Bibost, Anne-Laurence; Brown, Culum

2013-01-01

Cerebral lateralization is a widespread trait among animals, is often manifested as side biases in behaviour (laterality) and has been suggested to provide fitness benefits. Here we examined the influence of laterality on the organisation of fish schools using rainbowfish (Melanotaenia spp) as model species. The pattern and strength of laterality for each individual was determined by examining eye preferences whilst examining their reflection in a mirror. Schools of four fish of known laterality were then created and the preferred position for each fish within the school was repeatedly observed in a flume. Fish which showed right eye preferences in the mirror test preferentially adopted a position on the left side of the school. Conversely, fish that showed left eye preferences in the mirror test or where non-lateralised preferentially adopted a position slightly to the right side of the school. However, this general pattern varied depending on the species and sex of the school. Our results strongly implicate individual laterality in the geometry of school formation. PMID:24260506

Laterality influences schooling position in rainbowfish, Melanotaenia spp.

PubMed

Bibost, Anne-Laurence; Brown, Culum

2013-01-01

Cerebral lateralization is a widespread trait among animals, is often manifested as side biases in behaviour (laterality) and has been suggested to provide fitness benefits. Here we examined the influence of laterality on the organisation of fish schools using rainbowfish (Melanotaenia spp) as model species. The pattern and strength of laterality for each individual was determined by examining eye preferences whilst examining their reflection in a mirror. Schools of four fish of known laterality were then created and the preferred position for each fish within the school was repeatedly observed in a flume. Fish which showed right eye preferences in the mirror test preferentially adopted a position on the left side of the school. Conversely, fish that showed left eye preferences in the mirror test or where non-lateralised preferentially adopted a position slightly to the right side of the school. However, this general pattern varied depending on the species and sex of the school. Our results strongly implicate individual laterality in the geometry of school formation.

Predation Risk within Fishing Gear and Implications for South Australian Rock Lobster Fisheries

PubMed Central

Briceño, Felipe; Linnane, Adrian Joseph; Quiroz, Juan Carlos; Gardner, Caleb; Pecl, Gretta Tatyana

2015-01-01

Depredation of southern rock lobster (Jasus edwardsii) within fishing gear by the Maori octopus (Pinnoctopus cordiformis) has economic and ecological impacts on valuable fisheries in South Australia. In addition, depredation rates can be highly variable resulting in uncertainties for the fishery. We examined how in-pot lobster predation was influenced by factors such as lobster size and sex, season, fishing zone, and catch rate. Using mixed modelling techniques, we found that in-pot predation risk increased with lobster size and was higher for male lobsters. In addition, the effect of catch rate of lobsters on predation risk by octopus differed among fishing zones. There was both a seasonal and a spatial component to octopus predation, with an increased risk within discrete fishing grounds in South Australia at certain times of the year. Information about predation within lobster gear can assist fishery management decision-making, potentially leading to significant reduction in economic losses to the fishery. PMID:26489035

Type C botulism in pelicans and other fish-eating birds at the Salton Sea

USGS Publications Warehouse

Rocke, T.E.; Nol, P.; Pelizza, C.; Sturm, K.K.

2004-01-01

In 1996, type C avian botulism killed over 10,000 pelicans and nearly 10,000 other fish-eating birds at the Salton Sea in southern California. Although botulism had been previously documented in waterbirds at the Sea, this die-off was unusual in that it involved primarily fish-eating birds. The American White Pelican (Pelecanus erythrorynchos) was the species with the greatest mortality in 1996. Since 1996, mortality has recurred every year but losses have declined (<2,000 birds/year), with relatively more Brown Pelicans (P. occidentalis) than White Pelicans afflicted. In 2000, morbidity and mortality of Brown Pelicans with type C botulism (1311) approached the numbers afflicted in 1996 (2034). In recent years, mortality reached a peak earlier in the summer, July and August, in contrast to 1996 when mortality reached a peak in September. An exotic fish species, tilapia (Oreochromis mossambicus), has been implicated as the source of toxin for birds at Salton Sea, but the source of toxin for fish is unknown.

Locomotion in labrid fishes: implications for habitat use and cross-shelf biogeography on the Great Barrier Reef

NASA Astrophysics Data System (ADS)

Bellwood, D.; Wainwright, P.

2001-09-01

Coral reefs exhibit marked zonation patterns within single reefs and across continental shelves. For sessile organisms these zones are often related to wave exposure. We examined the extent to which wave exposure may shape the distribution patterns of fishes. We documented the distribution of 98 species of wrasses and parrotfishes at 33 sites across the Great Barrier Reef. The greatest difference between labrid assemblages was at the habitat level, with exposed reef flats and crests on mid- and outer reefs possessing a distinct faunal assemblage. These exposed sites were dominated by individuals with high pectoral fin aspect ratios, i.e. fishes believed to be capable of lift-based swimming which often achieve high speeds. Overall, there was a strong correlation between estimated swimming performance, as indicated by fin aspect ratio, and degree of water movement. We propose that swimming performance in fishes limits access to high-energy locations and may be a significant factor influencing habitat use and regional biogeography of reef fishes.

Fish fertilizer: a native north american practice?

PubMed

Ceci, L

1975-04-04

The belief that the use of fish fertilizers originated among North American Indians, and was communicated as such by Squanto to the Plymouth settlers, has achieved the status of folklore and is therefore difficult to challenge. However, examination of the documentary evidence of Squanto's history and of native cultivation practices, and a cultural analysis of the implications of the use of fish fertilizer, have produced complementary lines of evidence. This evidence indicates that widely held beliefs about the "manner of the Indians" should be revised: Squanto's advice at Plymouth is probably best viewed as an interesting example of culture contact, one in which a native "culture-bearer" conveyed a technological idea from one group of Europeans to another.

[Residues of tetracycline and quinolones in wild fish living around a salmon aquaculture center in Chile].

PubMed

Fortt Z, Antonia; Cabello C, Felipe; Buschmann R, Alejandro

2007-02-01

The presence of residues of tetracycline, quinolones and antiparasitic drugs was investigated in wild fish captured around salmon aquaculture pens in Cochamó, Region X, Chile. Residues of both antibiotics were found in the meta [corrected] of two species of wild fish that are consumed by humans, robalo (Elginops maclovinus) and cabrilla (Sebastes capensis) [corrected] These findings suggest that the antibiotic usage in salmon aquaculture in Chile has nvironmental implications that may affect human and animal health. More studies are needed in Chile to determine the relevance of these findings for human and animal health and the environment to regulate this use of antibiotics.

Husbandry stress exacerbates mycobacterial infections in adult zebrafish, Danio rerio (Hamilton)

USGS Publications Warehouse

Ramsay, J.M.; Watral, Virginia G.; Schreck, C.B.; Kent, M.L.

2009-01-01

Mycobacteria are significant pathogens of laboratory zebrafish, Danio rerio (Hamilton). Stress is often implicated in clinical disease and morbidity associated with mycobacterial infections but has yet to be examined with zebrafish. The aim of this study was to examine the effects of husbandry stressors on zebrafish infected with mycobacteria. Adult zebrafish were exposed to Mycobacterium marinum or Mycobacterium chelonae, two species that have been associated with disease in zebrafish. Infected fish and controls were then subjected to chronic crowding and handling stressors and examined over an 8-week period. Whole-body cortisol was significantly elevated in stressed fish compared to non-stressed fish. Fish infected with M. marinum ATCC 927 and subjected to husbandry stressors had 14% cumulative mortality while no mortality occurred among infected fish not subjected to husbandry stressors. Stressed fish, infected with M. chelonae H1E2 from zebrafish, were 15-fold more likely to be infected than non-stressed fish at week 8 post-injection. Sub-acute, diffuse infections were more common among stressed fish infected with M. marinum or M. chelonae than non-stressed fish. This is the first study to demonstrate an effect of stress and elevated cortisol on the morbidity, prevalence, clinical disease and histological presentation associated with mycobacterial infections in zebrafish. Minimizing husbandry stress may be effective at reducing the severity of outbreaks of clinical mycobacteriosis in zebrafish facilities. ?? 2009 Blackwell Publishing Ltd.

The Electric Field of a Weakly Electric Fish

NASA Astrophysics Data System (ADS)

Rasnow, Brian K.

Freshwater fish of the genus Apteronotus (family Gymnotidae) generate a weak, high frequency electric field (<100 mV/cm, 0.5-10 kHz) which permeates their local environment. These nocturnal fish are acutely sensitive to perturbations in their electric field caused by other electric fish, and nearby objects whose impedance is different from the surrounding water. This thesis presents high temporal and spatial resolution maps of the electric potential and field on and near Apteronotus. The fish's electric field is a complicated and highly stable function of space and time. Its characteristics, such as spectral composition, timing, and rate of attenuation, are examined in terms of physical constraints, and their possible functional roles in electroreception. Temporal jitter of the periodic field is less than 1 musec. However, electrocyte activity is not globally synchronous along the fish's electric organ. The propagation of electrocyte activation down the fish's body produces a rotation of the electric field vector in the caudal part of the fish. This may assist the fish in identifying nonsymmetrical objects, and could also confuse electrosensory predators that try to locate Apteronotus by following its fieldlines. The propagation also results in a complex spatiotemporal pattern of the EOD potential near the fish. Visualizing the potential on the same and different fish over timescales of several months suggests that it is stable and could serve as a unique signature for individual fish. Measurements of the electric field were used to calculate the effects of simple objects on the fish's electric field. The shape of the perturbation or "electric image" on the fish's skin is relatively independent of a simple object's size, conductivity, and rostrocaudal location, and therefore could unambiguously determine object distance. The range of electrolocation may depend on both the size of objects and their rostrocaudal location. Only objects with very large dielectric constants cause appreciable phase shifts, and these are strongly dependent on the water conductivity.

Underwater Intruder Detection Sonar for Harbour Protection: State of the Art Review and Implications

DTIC Science & Technology

2006-10-01

intruder would appear as a small moving “ blob ” of energetic echo in the echograph, and the operator could judge whether the contact is a threat that calls...visually then as a small fluctuating “ blob ” against a fluctuating background of sound clutter and reverberation, making it difficult to visually...4. Non-random false alarms caused by genuine underwater contacts that happened not to be intruders—by large fish , or schools of fish , or marine

The Influence of Coral Reef Benthic Condition on Associated Fish Assemblages

PubMed Central

Chong-Seng, Karen M.; Mannering, Thomas D.; Pratchett, Morgan S.; Bellwood, David R.; Graham, Nicholas A. J.

2012-01-01

Accumulative disturbances can erode a coral reef’s resilience, often leading to replacement of scleractinian corals by macroalgae or other non-coral organisms. These degraded reef systems have been mostly described based on changes in the composition of the reef benthos, and there is little understanding of how such changes are influenced by, and in turn influence, other components of the reef ecosystem. This study investigated the spatial variation in benthic communities on fringing reefs around the inner Seychelles islands. Specifically, relationships between benthic composition and the underlying substrata, as well as the associated fish assemblages were assessed. High variability in benthic composition was found among reefs, with a gradient from high coral cover (up to 58%) and high structural complexity to high macroalgae cover (up to 95%) and low structural complexity at the extremes. This gradient was associated with declining species richness of fishes, reduced diversity of fish functional groups, and lower abundance of corallivorous fishes. There were no reciprocal increases in herbivorous fish abundances, and relationships with other fish functional groups and total fish abundance were weak. Reefs grouping at the extremes of complex coral habitats or low-complexity macroalgal habitats displayed markedly different fish communities, with only two species of benthic invertebrate feeding fishes in greater abundance in the macroalgal habitat. These results have negative implications for the continuation of many coral reef ecosystem processes and services if more reefs shift to extreme degraded conditions dominated by macroalgae. PMID:22870294

The influence of coral reef benthic condition on associated fish assemblages.

PubMed

Chong-Seng, Karen M; Mannering, Thomas D; Pratchett, Morgan S; Bellwood, David R; Graham, Nicholas A J

2012-01-01

Accumulative disturbances can erode a coral reef's resilience, often leading to replacement of scleractinian corals by macroalgae or other non-coral organisms. These degraded reef systems have been mostly described based on changes in the composition of the reef benthos, and there is little understanding of how such changes are influenced by, and in turn influence, other components of the reef ecosystem. This study investigated the spatial variation in benthic communities on fringing reefs around the inner Seychelles islands. Specifically, relationships between benthic composition and the underlying substrata, as well as the associated fish assemblages were assessed. High variability in benthic composition was found among reefs, with a gradient from high coral cover (up to 58%) and high structural complexity to high macroalgae cover (up to 95%) and low structural complexity at the extremes. This gradient was associated with declining species richness of fishes, reduced diversity of fish functional groups, and lower abundance of corallivorous fishes. There were no reciprocal increases in herbivorous fish abundances, and relationships with other fish functional groups and total fish abundance were weak. Reefs grouping at the extremes of complex coral habitats or low-complexity macroalgal habitats displayed markedly different fish communities, with only two species of benthic invertebrate feeding fishes in greater abundance in the macroalgal habitat. These results have negative implications for the continuation of many coral reef ecosystem processes and services if more reefs shift to extreme degraded conditions dominated by macroalgae.

Fish as Reservoirs and Vectors of Vibrio cholerae

PubMed Central

Senderovich, Yigal; Izhaki, Ido; Halpern, Malka

2010-01-01

Vibrio cholerae, the etiologic agent of cholera, is autochthonous to various aquatic environments, but despite intensive efforts its ecology remains an enigma. Recently, it was suggested that copepods and chironomids, both considered as natural reservoirs of V. cholerae, are dispersed by migratory waterbirds, thus possibly distributing the bacteria between water bodies within and between continents. Although fish have been implicated in the scientific literature with cholera cases, as far as we know, no study actually surveyed the presence of the bacteria in the fish. Here we show for the first time that fish of various species and habitats contain V. cholerae in their digestive tract. Fish (n = 110) were randomly sampled from freshwater and marine habitats in Israel. Ten different fish species sampled from freshwater habitats (lake, rivers and fish ponds), and one marine species, were found to carry V. cholerae. The fish intestine of Sarotherodon galilaeus harboured ca. 5×103 V. cholerae cfu per 1 gr intestine content—high rates compared with known V. cholerae cfu numbers in the bacteria's natural reservoirs. Our results, combined with evidence from the literature, suggest that fish are reservoirs of V. cholerae. As fish carrying the bacteria swim from one location to another (some fish species move from rivers to lakes or sea and vice versa), they serve as vectors on a small scale. Nevertheless, fish are consumed by waterbirds, which disseminate the bacteria on a global scale. Moreover, V. cholerae isolates had the ability to degrade chitin, indicating a commensal relationship between V. cholerae and fish. Better understanding of V. cholerae ecology can help reduce the times that human beings come into contact with this pathogen and thus minimize the health risk this poses. PMID:20066040

Fish as reservoirs and vectors of Vibrio cholerae.

PubMed

Senderovich, Yigal; Izhaki, Ido; Halpern, Malka

2010-01-06

Vibrio cholerae, the etiologic agent of cholera, is autochthonous to various aquatic environments, but despite intensive efforts its ecology remains an enigma. Recently, it was suggested that copepods and chironomids, both considered as natural reservoirs of V. cholerae, are dispersed by migratory waterbirds, thus possibly distributing the bacteria between water bodies within and between continents. Although fish have been implicated in the scientific literature with cholera cases, as far as we know, no study actually surveyed the presence of the bacteria in the fish. Here we show for the first time that fish of various species and habitats contain V. cholerae in their digestive tract. Fish (n = 110) were randomly sampled from freshwater and marine habitats in Israel. Ten different fish species sampled from freshwater habitats (lake, rivers and fish ponds), and one marine species, were found to carry V. cholerae. The fish intestine of Sarotherodon galilaeus harboured ca. 5 x 10(3)V. cholerae cfu per 1 gr intestine content-high rates compared with known V. cholerae cfu numbers in the bacteria's natural reservoirs. Our results, combined with evidence from the literature, suggest that fish are reservoirs of V. cholerae. As fish carrying the bacteria swim from one location to another (some fish species move from rivers to lakes or sea and vice versa), they serve as vectors on a small scale. Nevertheless, fish are consumed by waterbirds, which disseminate the bacteria on a global scale. Moreover, V. cholerae isolates had the ability to degrade chitin, indicating a commensal relationship between V. cholerae and fish. Better understanding of V. cholerae ecology can help reduce the times that human beings come into contact with this pathogen and thus minimize the health risk this poses.

Fish intelligence, sentience and ethics.

PubMed

Brown, Culum

2015-01-01

Fish are one of the most highly utilised vertebrate taxa by humans; they are harvested from wild stocks as part of global fishing industries, grown under intensive aquaculture conditions, are the most common pet and are widely used for scientific research. But fish are seldom afforded the same level of compassion or welfare as warm-blooded vertebrates. Part of the problem is the large gap between people's perception of fish intelligence and the scientific reality. This is an important issue because public perception guides government policy. The perception of an animal's intelligence often drives our decision whether or not to include them in our moral circle. From a welfare perspective, most researchers would suggest that if an animal is sentient, then it can most likely suffer and should therefore be offered some form of formal protection. There has been a debate about fish welfare for decades which centres on the question of whether they are sentient or conscious. The implications for affording the same level of protection to fish as other vertebrates are great, not least because of fishing-related industries. Here, I review the current state of knowledge of fish cognition starting with their sensory perception and moving on to cognition. The review reveals that fish perception and cognitive abilities often match or exceed other vertebrates. A review of the evidence for pain perception strongly suggests that fish experience pain in a manner similar to the rest of the vertebrates. Although scientists cannot provide a definitive answer on the level of consciousness for any non-human vertebrate, the extensive evidence of fish behavioural and cognitive sophistication and pain perception suggests that best practice would be to lend fish the same level of protection as any other vertebrate.

The effects of clam fishing on the properties of surface sediments in the lagoon of Venice, Italy

NASA Astrophysics Data System (ADS)

Aspen, R. J.; Vardy, S.; Perkins, R. G.; Davidson, I. R.; Bates, R.; Paterson, D. M.

Harvesting of clams(Tapes philippinarum) has important socio-economic and environmental implications for the Venice lagoon area, Italy. Clam harvesting disrupts the structure of benthic communities but the effects upon sediment stability and surface structure remain unclear. The effect of clam fishing on the sediment properties of the lagoon bed was investigated at two different sites, a heavily fished site (San Angelo) and an infrequently fished site (San Giaccomo). Both sites were assessed for immediate impacts of fishing, using indicators of biogenic sediment stabilisation. Samples were taken at three points along three 100 m linear transects at each site prior to and post fishing. Paired samples were also taken parallel to each transect at a distance of 5m, to allow for temporal variation. Sediment stability, measured with a cohesive strength meter (CSM), was significantly higher at the less impacted site (F1,34 = 6.23, p < 0.018), was correlated with indicators of biogenic sediment stabilisation and decreased by approximately 50% following the trawling event. Concomitant decreases in chlorophyll a (chl a), colloidal-S carbohydrate and dry bulk density were observed on the transect after fishing but not adjacent to the fishing path. At the heavily impacted site, clam fishing by trawling had, in general, no significant effect on the biological and physical properties (although chl a did decrease significantly after fishing). The lack of a significant impact from fishing at the impacted site was attributed to the higher frequency of fishing occurring in this area. Hence, frequent fishing of the lagoon prevents establishment of biotic communities, preventing biostabilisation and thus reduces the stability of the surface sediment.

50 CFR 223.203 - Anadromous fish.

Code of Federal Regulations, 2011 CFR

2011-10-01

... identifiably unique biological and life history traits. Populations may be aggregated for management purposes... units, describe how the management units are defined, given biological and life history traits, so as to... impacts. (E) Provide for effective monitoring and adaptive management. (F) Use the best available science...

Dwarf char, a new form of chars (the genus Salvelinus) in Lake Kronotskoe

USGS Publications Warehouse

Pavlov, S.D.; Pivovarov, E.A.; Ostberg, C.O.

2012-01-01

Lake Kronotskoe is situated in the Kronotskii State Nature Reserve and is a unique natural heritage of Kamchatka. The lake–river system of the reserve includes numerous springs and small streams and three large inflowing rivers, Listvennichnaya, Unana, and Uzon, which form the main bays of Lake Kronotskoe; one river (Kronotskaya) flows from the lake. This river is characterized by several rapids, which are assumed to be unsurmountable barriers for fish migration. The ichthyofauna of the lake has been isolated for a long time, and some endemic fishes appeared, including char of the genus Salvelinus and the residential form of red salmon Oncorhynchus nerka (the local name is kokanee). These species are perfect model objects to study microevolution processes. Char of Lake Kronotskoe are characterized by significant polymorphism and plasticity [1–3]; therefore, they are extremely valuable for studying the processes of speciation and form development. That is why the populations of char in Lake Kronotskoe are unique and attract special attention of researchers. 

Functional morphology of the gills of the bowfin, Amia calva L., with special reference to their significance during air exposure.

PubMed

Daxboeck, C; Barnard, D K; Randall, D J

1981-03-01

The bowfin, Amia calva is a facultative air breathing fish restricted to North America and is reported to estivate. The relative and functional gill surface areas of A. calva are not reduced, as in many amphibious fish, but have areas comparable to many completely aquatic species. The secondary lamellae are fused to form a lattice-work of rectangular pores, a gill arrangement unique among fresh-water fishes. This highly modified gill structure imparts considerable rigidity such that these do not collapse upon air exposure. In vivo blood gas measurements from air exposed Amia reveal that these gills must be free of water, since there is both O2 uptake and CO2 excretion across them. The observed ventilatory motions therefore pass air over the secondary lamellae for diffusive gas exchange during air exposure. In the artificial conditions of our experiments, however, air exposure was associated with a marked acidosis and the fish died within 2 hours of being returned to normoxic water.

Hydrodynamic aspects of thrust generation in gymnotiform swimming

NASA Astrophysics Data System (ADS)

Shirgaonkar, Anup A.; Curet, Oscar M.; Patankar, Neelesh A.; Maciver, Malcolm A.

2008-11-01

The primary propulsor in gymnotiform swimmers is a fin running along most of the ventral midline of the fish. The fish propagates traveling waves along this ribbon fin to generate thrust. This unique mode of thrust generation gives these weakly electric fish great maneuverability cluttered spaces. To understand the mechanical basis of gymnotiform propulsion, we investigated the hydrodynamics of a model ribbon-fin of an adult black ghost knifefish using high-resolution numerical experiments. We found that the principal mechanism of thrust generation is a central jet imparting momentum to the fluid with associated vortex rings near the free edge of the fin. The high-fidelity simulations also reveal secondary vortex rings potentially useful in rapid sideways maneuvers. We obtained the scaling of thrust with respect to the traveling wave kinematic parameters. Using a fin-plate model for a fish, we also discuss improvements to Lighthill's inviscid theory for gymnotiform and balistiform modes in terms of thrust magnitude, viscous drag on the body, and momentum enhancement.

Resolution of ray-finned fish phylogeny and timing of diversification.

PubMed

Near, Thomas J; Eytan, Ron I; Dornburg, Alex; Kuhn, Kristen L; Moore, Jon A; Davis, Matthew P; Wainwright, Peter C; Friedman, Matt; Smith, W Leo

2012-08-21

Ray-finned fishes make up half of all living vertebrate species. Nearly all ray-finned fishes are teleosts, which include most commercially important fish species, several model organisms for genomics and developmental biology, and the dominant component of marine and freshwater vertebrate faunas. Despite the economic and scientific importance of ray-finned fishes, the lack of a single comprehensive phylogeny with corresponding divergence-time estimates has limited our understanding of the evolution and diversification of this radiation. Our analyses, which use multiple nuclear gene sequences in conjunction with 36 fossil age constraints, result in a well-supported phylogeny of all major ray-finned fish lineages and molecular age estimates that are generally consistent with the fossil record. This phylogeny informs three long-standing problems: specifically identifying elopomorphs (eels and tarpons) as the sister lineage of all other teleosts, providing a unique hypothesis on the radiation of early euteleosts, and offering a promising strategy for resolution of the "bush at the top of the tree" that includes percomorphs and other spiny-finned teleosts. Contrasting our divergence time estimates with studies using a single nuclear gene or whole mitochondrial genomes, we find that the former underestimates ages of the oldest ray-finned fish divergences, but the latter dramatically overestimates ages for derived teleost lineages. Our time-calibrated phylogeny reveals that much of the diversification leading to extant groups of teleosts occurred between the late Mesozoic and early Cenozoic, identifying this period as the "Second Age of Fishes."

Long-term changes in deep-water fish populations in the northeast Atlantic: a deeper reaching effect of fisheries?

PubMed

Bailey, D M; Collins, M A; Gordon, J D M; Zuur, A F; Priede, I G

2009-06-07

A severe scarcity of life history and population data for deep-water fishes is a major impediment to successful fisheries management. Long-term data for non-target species and those living deeper than the fishing grounds are particularly rare. We analysed a unique dataset of scientific trawls made from 1977 to 1989 and from 1997 to 2002, at depths from 800 to 4800 m. Over this time, overall fish abundance fell significantly at all depths from 800 to 2500 m, considerably deeper than the maximum depth of commercial fishing (approx. 1600 m). Changes in abundance were significantly larger in species whose ranges fell at least partly within fished depths and did not appear to be consistent with any natural factors such as changes in fluxes from the surface or the abundance of potential prey. If the observed decreases in abundance are due to fishing, then its effects now extend into the lower bathyal zone, resulting in declines in areas that have been previously thought to be unaffected. A possible mechanism is impacts on the shallow parts of the ranges of fish species, resulting in declines in abundance in the lower parts of their ranges. This unexpected phenomenon has important consequences for fisheries and marine reserve management, as this would indicate that the impacts of fisheries can be transmitted into deep offshore areas that are neither routinely monitored nor considered as part of the managed fishery areas.

Resolution of ray-finned fish phylogeny and timing of diversification

PubMed Central

Near, Thomas J.; Eytan, Ron I.; Dornburg, Alex; Kuhn, Kristen L.; Moore, Jon A.; Davis, Matthew P.; Wainwright, Peter C.; Friedman, Matt; Smith, W. Leo

2012-01-01

Ray-finned fishes make up half of all living vertebrate species. Nearly all ray-finned fishes are teleosts, which include most commercially important fish species, several model organisms for genomics and developmental biology, and the dominant component of marine and freshwater vertebrate faunas. Despite the economic and scientific importance of ray-finned fishes, the lack of a single comprehensive phylogeny with corresponding divergence-time estimates has limited our understanding of the evolution and diversification of this radiation. Our analyses, which use multiple nuclear gene sequences in conjunction with 36 fossil age constraints, result in a well-supported phylogeny of all major ray-finned fish lineages and molecular age estimates that are generally consistent with the fossil record. This phylogeny informs three long-standing problems: specifically identifying elopomorphs (eels and tarpons) as the sister lineage of all other teleosts, providing a unique hypothesis on the radiation of early euteleosts, and offering a promising strategy for resolution of the “bush at the top of the tree” that includes percomorphs and other spiny-finned teleosts. Contrasting our divergence time estimates with studies using a single nuclear gene or whole mitochondrial genomes, we find that the former underestimates ages of the oldest ray-finned fish divergences, but the latter dramatically overestimates ages for derived teleost lineages. Our time-calibrated phylogeny reveals that much of the diversification leading to extant groups of teleosts occurred between the late Mesozoic and early Cenozoic, identifying this period as the “Second Age of Fishes.” PMID:22869754

Chronic nitrate enrichment decreases severity and induces protection against an infectious disease.

PubMed

Smallbone, Willow; Cable, Jo; Maceda-Veiga, Alberto

2016-05-01

Excessive fertilisation is one of the most pernicious forms of global change resulting in eutrophication. It has major implications for disease control and the conservation of biodiversity. Yet, the direct link between nutrient enrichment and disease remains largely unexplored. Here, we present the first experimental evidence that chronic nitrate enrichment decreases severity and induces protection against an infectious disease. Specifically, this study shows that nitrate concentrations ranging between 50 and 250mgNO3(-)/l reduce Gyrodactylus turnbulli infection intensity in two populations of Trinidadian guppies Poecilia reticulata, and that the highest nitrate concentration can even clean the parasites from the fish. This added to the fact that host nitrate pre-exposure altered the fish epidermal structure and reduced parasite intensity, suggests that nitrate protected the host against the disease. Nitrate treatments also caused fish mortality. As we used ecologically-relevant nitrate concentrations, and guppies are top-consumers widely used for mosquito bio-control in tropical and often nutrient-enriched waters, our results can have major ecological and social implications. In conclusion, this study advocates reducing nitrate level including the legislative threshold to protect the aquatic biota, even though this may control an ectoparasitic disease. Copyright © 2016 Elsevier Ltd. All rights reserved.

Floodplain farm fields provide novel rearing habitat for Chinook salmon

PubMed Central

Jeffres, Carson; Conrad, J. Louise; Sommer, Ted R.; Martinez, Joshua; Brumbaugh, Steve; Corline, Nicholas; Moyle, Peter B.

2017-01-01

When inundated by floodwaters, river floodplains provide critical habitat for many species of fish and wildlife, but many river valleys have been extensively leveed and floodplain wetlands drained for flood control and agriculture. In the Central Valley of California, USA, where less than 5% of floodplain wetland habitats remain, a critical conservation question is how can farmland occupying the historical floodplains be better managed to improve benefits for native fish and wildlife. In this study fields on the Sacramento River floodplain were intentionally flooded after the autumn rice harvest to determine if they could provide shallow-water rearing habitat for Sacramento River fall-run Chinook salmon (Oncorhynchus tshawytscha). Approximately 10,000 juvenile fish (ca. 48 mm, 1.1 g) were reared on two hectares for six weeks (Feb-March) between the fall harvest and spring planting. A subsample of the fish were uniquely tagged to allow tracking of individual growth rates (average 0.76 mm/day) which were among the highest recorded in fresh water in California. Zooplankton sampled from the water column of the fields were compared to fish stomach contents. The primary prey was zooplankton in the order Cladocera, commonly called water fleas. The compatibility, on the same farm fields, of summer crop production and native fish habitat during winter demonstrates that land management combining agriculture with conservation ecology may benefit recovery of native fish species, such as endangered Chinook salmon. PMID:28591141

High compliance with dietary recommendations in a cohort of meat eaters, fish eaters, vegetarians, and vegans: results from the European Prospective Investigation into Cancer and Nutrition–Oxford study☆☆☆

PubMed Central

Sobiecki, Jakub G.; Appleby, Paul N.; Bradbury, Kathryn E.; Key, Timothy J.

2016-01-01

The aim of this study was to investigate differences in dietary intakes between 30 251 participants in the European Prospective Investigation into Cancer and Nutrition–Oxford study, comprising 18 244 meat eaters, 4 531 fish eaters, 6 673 vegetarians, and 803 vegans aged 30 to 90 years who completed semiquantitative food frequency questionnaires. We hypothesized that these groups characterized by varying degrees of animal product exclusion have significantly different intakes of many nutrients, with possible implications for dietary adequacy and compliance with population dietary goals. Nutrient intakes were estimated including fortification in foods, but excluding dietary supplements. Dietary supplementation practices were also evaluated. Highly significant differences were found in estimated nutrient intakes between meat eaters and vegans, with fish eaters and vegetarians usually having intermediate values. Meat eaters had the highest energy intakes, followed by fish eaters and vegetarians, whereas vegans had the lowest intakes. Vegans had the highest intakes of polyunsaturated fatty acids, dietary fiber, vitamins C and E, folate, magnesium, iron, and copper. Meat eaters had the highest intake of saturated fatty acids, protein, vitamin B2, vitamin B12, vitamin D, zinc, and iodine. Fish eaters had the highest intakes of calcium and selenium. There were no statistically significant differences in sodium and potassium intakes between dietary groups. With the exception of sodium intake, compliance with population dietary goals was high across diet groups. The results suggested a high prevalence of inadequacy for dietary vitamin B12 and iodine in vegans. The diet groups under study showed striking differences in dietary intakes, with possible implications for compliance with dietary recommendations, as well as cardiometabolic diseases risk. PMID:27101764

High compliance with dietary recommendations in a cohort of meat eaters, fish eaters, vegetarians, and vegans: results from the European Prospective Investigation into Cancer and Nutrition-Oxford study.

PubMed

Sobiecki, Jakub G; Appleby, Paul N; Bradbury, Kathryn E; Key, Timothy J

2016-05-01

The aim of this study was to investigate differences in dietary intakes between 30251 participants in the European Prospective Investigation into Cancer and Nutrition-Oxford study, comprising 18 244 meat eaters, 4 531 fish eaters, 6 673 vegetarians, and 803 vegans aged 30 to 90 years who completed semiquantitative food frequency questionnaires. We hypothesized that these groups characterized by varying degrees of animal product exclusion have significantly different intakes of many nutrients, with possible implications for dietary adequacy and compliance with population dietary goals. Nutrient intakes were estimated including fortification in foods, but excluding dietary supplements. Dietary supplementation practices were also evaluated. Highly significant differences were found in estimated nutrient intakes between meat eaters and vegans, with fish eaters and vegetarians usually having intermediate values. Meat eaters had the highest energy intakes, followed by fish eaters and vegetarians, whereas vegans had the lowest intakes. Vegans had the highest intakes of polyunsaturated fatty acids, dietary fiber, vitamins C and E, folate, magnesium, iron, and copper. Meat eaters had the highest intake of saturated fatty acids, protein, vitamin B2, vitamin B12, vitamin D, zinc, and iodine. Fish eaters had the highest intakes of calcium and selenium. There were no statistically significant differences in sodium and potassium intakes between dietary groups. With the exception of sodium intake, compliance with population dietary goals was high across diet groups. The results suggested a high prevalence of inadequacy for dietary vitamin B12 and iodine in vegans. The diet groups under study showed striking differences in dietary intakes, with possible implications for compliance with dietary recommendations, as well as cardiometabolic diseases risk. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

Distribution of microcystins in a lake foodweb: no evidence for biomagnification.

PubMed

Ibelings, B W; Bruning, K; de Jonge, J; Wolfstein, K; Pires, L M Dionisio; Postma, J; Burger, T

2005-05-01

Microcystins, toxins produced by cyanobacteria, may play a role in fish kills, although their specific contribution remains unclear. A better understanding of the eco-toxicological effects of microcystins is hampered by a lack of analyses at different trophic levels in lake foodwebs. We present 3 years of monitoring data, and directly compare the transfer of microcystin in the foodweb starting with the uptake of (toxic) cyanobacteria by two different filter feeders: the cladoceran Daphnia galeata and the zebra mussel Dreissena polymorpha. Furthermore foodwebs are compared in years in which the colonial cyanobacterium Microcystis aeruginosa or the filamentous cyanobacterium Planktothrix agardhii dominated; there are implications in terms of the types and amount of microcystins produced and in the ingestion of cyanobacteria. Microcystin concentrations in the seston commonly reached levels where harmful effects on zooplankton are to be expected. Likewise, concentrations in zooplankton reached levels where intoxication of fish is likely. The food chain starting with Dreissena (consumed by roach and diving ducks) remained relatively free from microcystins. Liver damage, typical for exposure to microcystins, was observed in a large fraction of the populations of different fish species, although no relation with the amount of microcystin could be established. Microcystin levels were especially high in the livers of planktivorous fish, mainly smelt. This puts piscivorous birds at risk. We found no evidence for biomagnification of microcystins. Concentrations in filter feeders were always much below those in the seston, and yet vectorial transport to higher trophic levels took place. Concentrations of microcystin in smelt liver exceeded those in the diet of these fish, but it is incorrect to compare levels in a selected organ to those in a whole organism (zooplankton). The discussion focuses on the implications of detoxication and covalent binding of microcystin for the transfer of the toxin in the foodweb. It seems likely that microcystins are one, but not the sole, factor involved in fish kills during blooms of cyanobacteria.

A fish is not a fish: patterns in fatty acid composition of aquatic food may have had implications for hominin evolution.

PubMed

Joordens, Josephine C A; Kuipers, Remko S; Wanink, Jan H; Muskiet, Frits A J

2014-12-01

From c. 2 Ma (millions of years ago) onwards, hominin brain size and cognition increased in an unprecedented fashion. The exploitation of high-quality food resources, notably from aquatic ecosystems, may have been a facilitator or driver of this phenomenon. The aim of this study is to contribute to the ongoing debate on the possible role of aquatic resources in hominin evolution by providing a more detailed nutritional context. So far, the debate has focused on the relative importance of terrestrial versus aquatic resources while no distinction has been made between different types of aquatic resources. Here we show that Indian Ocean reef fish and eastern African lake fish yield on average similarly high amounts of eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), and arachidonic acid (AA). Hence a shift from exploiting tropical marine to freshwater ecosystems (or vice versa) would entail no material difference in dietary long-chain polyunsaturated fatty acid (LC-PUFA) availability. However, a shift to marine ecosystems would likely mean a major increase in access to brain-selective micronutrients such as iodine. Fatty fish from marine temperate/cold waters yield twice as much DHA and four times as much EPA as tropical fish, demonstrating that a latitudinal shift in exploitation of African coastal ecosystems could constitute a significant difference in LC-PUFA availability with possible implications for brain development and functioning. We conclude that exploitation of aquatic food resources could have facilitated the initial moderate hominin brain increase as observed in fossils dated to c. 2 Ma, but not the exceptional brain increase in later stages of hominin evolution. We propose that the significant expansion in hominin brain size and cognition later on may have been aided by strong directional selecting forces such as runaway sexual selection of intelligence, and nutritionally supported by exploitation of high-quality food resources in stable and productive aquatic ecosystems. Copyright © 2014 Elsevier Ltd. All rights reserved.

Levels and patterns of persistent organic pollutants (POPs) in tilapia (Oreochromis sp.) from four different lakes in Tanzania: geographical differences and implications for human health.

PubMed

Polder, A; Müller, M B; Lyche, J L; Mdegela, R H; Nonga, H E; Mabiki, F P; Mbise, T J; Skaare, J U; Sandvik, M; Skjerve, E; Lie, E

2014-08-01

In Tanzania fish is one of the most important protein sources for the rapidly increasing population. Wild fish is threatened by overfishing and pollution from agriculture, industries, mining, household effluents and vector control. To monitor possible implications for public health, the geographical differences of the occurrence and levels of persistent organic pollutants (POPs) in tilapia fish (Oreochromis sp.) from four different Tanzanian lakes were investigated in 2011. Concentrations of organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs), polybrominated diphenyls (PBDEs) and hexabromocyclododecane (HBCDD) were determined in pooled samples of tilapia muscle from Lake (L) Victoria, L. Tanganyika, L. Nyasa (also called L. Malawi) and L. Babati in Tanzania in 2011. Levels of Σ-DDTs (274 ng/g lipid weight (lw)) and sum of 7 indicator PCBs (Σ-7PCBs) (17 ng/g lw) were significantly higher in tilapia from L. Tanganyika compared to the other lakes. The highest levels of Σ-endosulfan (94 ng/g lw) were detected in tilapia from L. Victoria. Toxaphenes were detected in low levels in fish from L. Tanganyika and L. Babati. Results revealed a geographic difference in the use of DDT and endosulfan between L. Victoria and L. Tanganyika. Low ratios of DDE/DDT in tilapia from L. Tanganyika indicated an on-going use of DDT in the area. Median levels of ΣBDEs, including BDE-209, were highest in L. Victoria (19.4 ng/g lw) and BDE-209 was present in 68% of the samples from this lake. The presence of BDE-209 indicates increasing influence of imported products from heavy industrialized countries. The measured POP levels in the studied tilapia were all below MRLs of EU or were lower than recommended levels, and thus the fish is considered as safe for human consumption. They may, however, pose a risk to the fish species and threaten biodiversity. Copyright © 2014 Elsevier B.V. All rights reserved.

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

PubMed Central

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

2016-01-01

Fishes use multimodal signals during both inter- and intra-sexual displays to convey information about their sex, reproductive state, and social status. These complex behavioral displays can include visual, auditory, olfactory, tactile, and hydrodynamic signals, and the relative role of each sensory channel in these complex multi-sensory interactions is a common focus of neuroethology. The mechanosensory lateral line system of fishes detects near-body water movements and is implicated in a variety of behaviors including schooling, rheotaxis, social communication, and prey detection. Cobalt chloride is commonly used to chemically ablate lateral line neuromasts, thereby eliminating water-movement cues to test for mechanosensory-mediated behavioral functions. However, cobalt acts as a nonspecific calcium channel antagonist and could potentially disrupt function of all superficially located sensory receptor cells, including those for chemosensing. Here, we examined whether CoCl2 treatment used to ablate the lateral line system also impairs olfaction in three freshwater fishes, the African cichlid fish Astatotilapia burtoni, goldfish Carassius auratus, and the Mexican blind cavefish Astyanax mexicanus. To examine the impact of CoCl2 on the activity of peripheral receptors, we quantified DASPEI fluorescence intensity of the olfactory epithelium from fish exposed to control and CoCl2 solutions. In addition, we examined brain activation in olfactory processing regions of A. burtoni immersed in either control or cobalt solutions. All three species exposed to CoCl2 had decreased DASPEI staining of the olfactory epithelium, and in A. burtoni, cobalt treatment caused reduced neural activation in olfactory processing regions of the brain. To our knowledge this is the first empirical evidence demonstrating that the same CoCl2 treatment used to ablate the lateral line system also impairs olfactory function. These data have important implications for the use of CoCl2 in future research and suggest that previous studies using CoCl2 should be reinterpreted in the context of both impaired mechanoreception and olfaction. PMID:27416112

Archer fish fast hunting maneuver may be guided by directionally selective retinal ganglion cells.

PubMed

Tsvilling, Vadim; Donchin, Opher; Shamir, Maoz; Segev, Ronen

2012-02-01

Archer fish are known for their unique hunting method, where one fish in a group shoots down an insect with a jet of water while all the other fish are observing the prey's motion. To reap its reward, the archer fish must reach the prey before its competitors. This requires fast computation of the direction of motion of the prey, which enables the fish to initiate a turn towards the prey with an accuracy of 99%, at about 100 ms after the prey is shot. We explored the hypothesis that direction-selective retinal ganglion cells may underlie this rapid processing. We quantified the degree of directional selectivity of ganglion cells in the archer fish retina. The cells could be categorized into three groups: sharply (5%), broadly (37%) and non-tuned (58%) directionally selective cells. To relate the electrophysiological data to the behavioral results we studied a computational model and estimated the time required to accumulate sufficient directional information to match the decision accuracy of the fish. The computational model is based on two direction-selective populations that race against each other until one reaches the threshold and drives the decision. We found that this competition model can account for the observed response time at the required accuracy. Thus, our results are consistent with the hypothesis that the fast response behavior of the archer fish relies on retinal identification of movement direction. © 2012 The Authors. European Journal of Neuroscience © 2012 Federation of European Neuroscience Societies and Blackwell Publishing Ltd.

Modulation of telomerase activity in fish muscle by biological and environmental factors.

PubMed

Peterson, Drew Ryan; Mok, Helen Oi Lam; Au, Doris Wai Ting

2015-12-01

Telomerase expression has long been linked to promotion of tumor growth and cell proliferation in mammals. Interestingly, telomerase activity (TA) has been detected in skeletal muscle for a variety of fish species. Despite this being a unique feature in fish, very few studies have investigated the potential role of TA in muscle. The present study was set to prove the concepts that muscle telomerase in fish is related to body growth, and more specifically, to muscle cell proliferation and apoptosis in vivo. Moreover, muscle TA can be influenced by biotic factors and modulated by environmental stress. Using three fish species, mangrove red snapper (Lutjanus argentimaculatus), orange-spotted grouper (Epinephelus coioides), and marine medaka (Oryzias melastigma), the present work reports for the first time that fish muscle TA was sensitive to the environmental stresses of starvation, foodborne exposure to benzo[a]pyrene, and hypoxia. In marine medaka, muscle TA was coupled with fish growth during early life stages. Upon sexual maturation, muscle TA was confounded by sex (female>male). Muscle TA was significantly correlated with telomerase reverse transcriptase (TERT) protein expression (Pearson correlation r=0.892; p≤0.05), which was coupled with proliferating cell nuclear antigen (PCNA) cell proliferation, but not associated with apoptosis (omBax/omBcl2 ratio) in muscle tissue. The results reported here have bridged the knowledge gap between the existence and function of telomerase in fish muscle. The underlying regulatory mechanisms of muscle TA in fish warrant further exploration for comparison with telomerase regulation in mammals. Copyright © 2015 Elsevier Inc. All rights reserved.

Relationships among catch, angler catisfaction, and fish assemblage characteristics of an urban small impoundment fishery

USGS Publications Warehouse

Ivasauskas, Tomas J.; Xiong, Wilson N.; Engman, Augustin C.; Fischer, Jesse R.; Kwak, Thomas J.; Rundle, Kirk R.

2017-01-01

Urban fisheries provide unique angling opportunities for people from traditionally underrepresented demographics. Lake Raleigh is a 38-ha impoundment located on the North Carolina State University campus in Raleigh. Like many urban fisheries, little is known about angler use and satisfaction or how angling catch rate is related to fish availability in Lake Raleigh. We characterized the recreational fishery and fish assemblage with concurrent creel and boat electrofishing surveys over the course of one year. In total, 245 anglers were interviewed on 68 survey days. On average, anglers spent 1.7 h fishing per trip and caught 0.385 fish h –1. A large proportion of anglers (43.9%) targeted multiple species, whereas 36.5% targeted largemouth bass (Micropterus salmoides), 10.0% targeted panfish (i.e., sunfishes [Lepomis spp.] and crappies [Pomoxis spp.]), and 9.6% targeted catfish (Ameiurus spp. and Ictalurus spp.). Most anglers (69.4%) were satisfied with their experience, and overall satisfaction was unrelated to catch rate. Pulsed-DC boat electrofishing was conducted on 25 dates, and 617 fish were sampled. Angler catch rate was unrelated to electrofishing catch rate, implying that anglers' catch rate was independent of fish density or availability. Our results demonstrate that even minimally managed urban fisheries can provide high angler satisfaction, with limited dedication of management resources. Relationships Among Catch, Angler Satisfaction, and Fish Assemblage Characteristics of an Urban Small Impoundment Fishery (PDF Download Available). Available from: https://www.researchgate.net/publication/316636550_Relationships_Among_Catch_Angler_Satisfaction_and_Fish_Assemblage_Characteristics_of_an_Urban_Small_Impoundment_Fishery [accessed Aug 11, 2017].

Critical swimming speed of brown trout (Salmo trutta) infested with freshwater pearl mussel (Margaritifera margaritifera) glochidia and implications for artificial breeding of an endangered mussel species.

PubMed

Taeubert, Jens-Eike; Geist, Juergen

2013-04-01

Unionid freshwater mussels need to attach to a host fish for completion of their life cycle. It remains unclear whether the relationship between these mussels and their host fishes can be considered parasitic, mutualistic, or commensal. Herein, we studied the effects of Margaritifera margaritifera infestation on Salmo trutta, the most important host of this endangered mussel species in Central Europe. Glochidial load of host fish increased with increasing glochidial concentration, but the highest ratios of encysted glochidia to exposed glochidia were found at low concentration (15,000 glochidia L(-1)) during infestation. Host fish mortality occurred at infestation rates of ~350 glochidia per g fish weight and was highest (60%) at the highest infestation rates (~900 glochidia per g fish weight). On a sublethal level, swimming performance of hosts was inversely related to infestation rates, with infestation of ~900 glochidia per g fish weight reducing critical swimming speed of S. trutta significantly by ~20% compared to infestation with 6 glochidia per g fish weight. The high mortality and the impaired swimming capability of highly infested hosts indicate a parasitic interaction between M. margaritifera and its host. For conservation and reintroduction of M. margaritifera via glochidia-infested S. trutta, we recommend glochidial loads of 5-100 glochidia per g fish weight, while for artificial breeding of juvenile M. margaritifera under laboratory conditions, higher infestation rates of up to 300 glochidia per g fish weight are ideal to balance high yields of mussels and welfare of host fishes.

Fish communities of the Sacramento River Basin: Implications for conservation of native fishes in the Central Valley, California

USGS Publications Warehouse

May, J.T.; Brown, L.R.

2002-01-01

The associations of resident fish communities with environmental variables and stream condition were evaluated at representative sites within the Sacramento River Basin, California between 1996 and 1998 using multivariate ordination techniques and by calculating six fish community metrics. In addition, the results of the current study were compared with recent studies in the San Joaquin River drainage to provide a wider perspective of the condition of resident fish communities in the Central Valley of California as a whole. Within the Sacramento drainage, species distributions were correlated with elevational and substrate size gradients; however, the elevation of a sampling site was correlated with a suite of water-quality and habitat variables that are indicative of land use effects on physiochemical stream parameters. Four fish community metrics - percentage of native fish, percentage of intolerant fish, number of tolerant species, and percentage of fish with external anomalies - were responsive to environmental quality. Comparisons between the current study and recent studies in the San Joaquin River drainage suggested that differences in water-management practices may have significant effects on native species fish community structure. Additionally, the results of the current study suggest that index of biotic integrity-type indices can be developed for the Sacramento River Basin and possibly the entire Central Valley, California. The protection of native fish communities in the Central Valley and other arid environments continues to be a conflict between human needs for water resources and the requirements of aquatic ecosystems; preservation of these ecosystems will require innovative management strategies.

76 FR 25666 - Submission for OMB Review; Comment Request

Federal Register 2010, 2011, 2012, 2013, 2014

2011-05-05

... such as estuaries and sloughs; and snorkeling or scuba diving on fish aggregating devices such as ship wrecks. The survey will help enhance NMFS' understanding of the economic implications of its public trust...

Sea-louse parasites on juvenile wild salmon in the Broughton Archipelago, British Columbia, Canada.

PubMed

Peacock, Stephanie J; Bateman, Andrew W; Krkošek, Martin; Connors, Brendan; Rogers, Scott; Portner, Lauren; Polk, Zephyr; Webb, Coady; Morton, Alexandra

2016-07-01

The global expansion of aquaculture has changed the structure of fish populations in coastal environments, with implications for disease dynamics. In Pacific Canada, farmed salmon act as reservoir hosts for parasites and pathogens, including sea lice (Lepeophtheirus salmonis and Caligus clemensi) that can transmit to migrating wild salmon. Assessing the impact of salmon farms on wild salmon requires regular monitoring of sea-louse infections on both farmed and wild fish. Since 2001, we have collected juvenile pink (Oncorhynchus gorbuscha) and chum (O. keta) salmon annually at three sites in the Broughton Archipelago in British Columbia, Canada, during the annual juvenile salmon migration from fresh water to the open ocean. From sampled fish, we recorded counts of parasitic copepodid-, chalimus-, and motile-stage sea lice. We report louse abundances as well as supplementary observations of fish size, development, and health. © 2016 by the Ecological Society of America.

Estrogenic alkylphenols in fish tissues, sediments, and waters from the U.K. Tyne and Tees estuaries

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lye, C.M.; Frid, C.L.J.; Gill, M.E.

1999-04-01

Nonylphenols and related compounds are common products of biodegradation of a large group of nonionic surfactants, the nonylphenol polyethoxylates. Many of these compounds are known to be environmentally persistent and to elicit estrogenic response in both mammals and fish. In this study, nonylphenol (NP), nonylphenol monoethoxylate (NP1EO), and octylphenol (OP) were found in tissues of mature male flounder, Platichthys flesus, and in tissues of juvenile flounder. These fish also showed detectable levels of the yolk protein vitellogenin in their plasma, indicative of estrogenic exposure. The compounds were also found in discharges from a major sewage treatment works and in sedimentsmore » from two estuaries in north-east England; the highest levels from the highly industrialized Tees and lower levels from the industrialized/urbanized Tyne estuary. The implications of these findings for fish populations are discussed.« less

Marine Biodiversity in Juan Fernández and Desventuradas Islands, Chile: Global Endemism Hotspots

PubMed Central

Friedlander, Alan M.; Ballesteros, Enric; Caselle, Jennifer E.; Gaymer, Carlos F.; Palma, Alvaro T.; Petit, Ignacio; Varas, Eduardo; Muñoz Wilson, Alex; Sala, Enric

2016-01-01

The Juan Fernández and Desventuradas islands are among the few oceanic islands belonging to Chile. They possess a unique mix of tropical, subtropical, and temperate marine species, and although close to continental South America, elements of the biota have greater affinities with the central and south Pacific owing to the Humboldt Current, which creates a strong biogeographic barrier between these islands and the continent. The Juan Fernández Archipelago has ~700 people, with the major industry being the fishery for the endemic lobster, Jasus frontalis. The Desventuradas Islands are uninhabited except for a small Chilean military garrison on San Félix Island. We compared the marine biodiversity of these islands across multiple taxonomic groups. At San Ambrosio Island (SA), in Desventuradas, the laminarian kelp (Eisenia cokeri), which is limited to Desventuradas in Chile, accounted for >50% of the benthic cover at wave exposed areas, while more sheltered sites were dominated by sea urchin barrens. The benthos at Robinson Crusoe Island (RC), in the Juan Fernández Archipelago, comprised a diverse mix of macroalgae and invertebrates, a number of which are endemic to the region. The biomass of commercially targeted fishes was >2 times higher in remote sites around RC compared to sheltered locations closest to port, and overall biomass was 35% higher around SA compared to RC, likely reflecting fishing effects around RC. The number of endemic fish species was extremely high at both islands, with 87.5% of the species surveyed at RC and 72% at SA consisting of regional endemics. Remarkably, endemics accounted for 99% of the numerical abundance of fishes surveyed at RC and 96% at SA, which is the highest assemblage-level endemism known for any individual marine ecosystem on earth. Our results highlight the uniqueness and global significance of these biodiversity hotspots exposed to very different fishing pressures. PMID:26734732

Marine Biodiversity in Juan Fernández and Desventuradas Islands, Chile: Global Endemism Hotspots.

PubMed

Friedlander, Alan M; Ballesteros, Enric; Caselle, Jennifer E; Gaymer, Carlos F; Palma, Alvaro T; Petit, Ignacio; Varas, Eduardo; Muñoz Wilson, Alex; Sala, Enric

2016-01-01

The Juan Fernández and Desventuradas islands are among the few oceanic islands belonging to Chile. They possess a unique mix of tropical, subtropical, and temperate marine species, and although close to continental South America, elements of the biota have greater affinities with the central and south Pacific owing to the Humboldt Current, which creates a strong biogeographic barrier between these islands and the continent. The Juan Fernández Archipelago has ~700 people, with the major industry being the fishery for the endemic lobster, Jasus frontalis. The Desventuradas Islands are uninhabited except for a small Chilean military garrison on San Félix Island. We compared the marine biodiversity of these islands across multiple taxonomic groups. At San Ambrosio Island (SA), in Desventuradas, the laminarian kelp (Eisenia cokeri), which is limited to Desventuradas in Chile, accounted for >50% of the benthic cover at wave exposed areas, while more sheltered sites were dominated by sea urchin barrens. The benthos at Robinson Crusoe Island (RC), in the Juan Fernández Archipelago, comprised a diverse mix of macroalgae and invertebrates, a number of which are endemic to the region. The biomass of commercially targeted fishes was >2 times higher in remote sites around RC compared to sheltered locations closest to port, and overall biomass was 35% higher around SA compared to RC, likely reflecting fishing effects around RC. The number of endemic fish species was extremely high at both islands, with 87.5% of the species surveyed at RC and 72% at SA consisting of regional endemics. Remarkably, endemics accounted for 99% of the numerical abundance of fishes surveyed at RC and 96% at SA, which is the highest assemblage-level endemism known for any individual marine ecosystem on earth. Our results highlight the uniqueness and global significance of these biodiversity hotspots exposed to very different fishing pressures.

Marine Habitat Use by Anadromous Bull Trout from the Skagit River, Washington

USGS Publications Warehouse

Hayes, Michael C.; Rubin, Steve P.; Reisenbichler, Reginald; Goetz, Fred A.; Jeanes, Eric; McBride, Aundrea

2011-01-01

Acoustic telemetry was used to describe fish positions and marine habitat use by tagged bull trout Salvelinus confluentus from the Skagit River, Washington. In March and April 2006, 20 fish were captured and tagged in the lower Skagit River, while 15 fish from the Swinomish Channel were tagged during May and June. Sixteen fish tagged in 2004 and 2005 were also detected during the study. Fish entered Skagit Bay from March to May and returned to the river from May to August. The saltwater residency for the 13 fish detected during the out-migration and return migration ranged from 36 to 133 d (mean ± SD, 75 ± 22 d). Most bull trout were detected less than 14 km (8.5 ± 4.4 km) from the Skagit River, and several bay residents used the Swinomish Channel while migrating. The bull trout detected in the bay were associated with the shoreline (distance from shore, 0.32 ± 0.27 km) and occupied shallow-water habitats (mean water column depth, Zostera sp.) vegetation classes made up more than 70% of the area used by bull trout. Our results will help managers identify specific nearshore areas that may require further protection to sustain the unique anadromous life history of bull trout.

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

PubMed

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

2016-03-16

Worldwide biodiversity assessments have mainly focused on species richness but little is known about the diversity of species roles, i.e. functional diversity, while this is a key facet to understanding the consequences of global changes on the ecosystem services to human societies. Here, we report the world pattern of functional diversity of freshwater fish using a database encompassing morphological characteristics of more than 9,000 species. The Neotropical realm hosts more than 75% of global functional diversity while other realms each host less than 25%. This discrepancy is mediated by high functional uniqueness in some diversified Neotropical fish orders. Surprisingly, functional diversity patterns were weakly related to functional vulnerability. In the Neotropics the loss of threatened species will cause a limited loss of functional diversity (<10%) whereas in the Nearctic and Palearctic realms, decline of the functional diversity will reach 43% and 33%, respectively, conferring a high functional vulnerability to these realms. Conservation of the Neotropical fish diversity is a key target to maintain world fish functional diversity, but this should not hide the pressing need to conserve the vulnerable fish faunas of the rest of the world, in which functional diversity is to a large extent supported by threatened species.

Linking Fossil Fish Cyclicity and Paleoenvironmental Proxies in the mid-Devonian

NASA Astrophysics Data System (ADS)

Grogan, D.; Whiteside, J. H.; Trewin, N. H.; Johnson, J. E.

2009-12-01

The significant radiation of fishes throughout the Devonian, combined with the abundance of well-preserved fossil fish assemblages from this period, provides for a high-resolution record of prevalent fish taxa in the Orcadian basin of North Scotland. In addition to their ability to serve as a lake-level and lake-chemistry proxy, the waxing and waning of dominant fish taxa exhibit a pronounced cyclicity, suggesting they respond to broader climate rhythms. Recent studies of mid-Devonian lacustrine sedimentary sequences have quantitatively demonstrated the presence of Milankovitch cyclicity in geochemical and gamma ray proxy records. Spectral analysis of gamma ray data show a strong obliquity peak usually associated with ice-house conditions; this obliquity signal is unexpected as tropical latitudes in the mid-Devonian are traditionally thought to have been in a greenhouse climate. Geochemical data include the measurement of bulk carbon and nitrogen stable isotopes, molecule-specific carbon isotopes of plant biomarkers, and depth ranks from eight sections of the Caithness Flagstone Group of the Orcadian Basin. Evidence for orbital forcing of climate change paired with the fossil fish record provides a unique opportunity to establish an astronomically calibrated timescale for the mid-Devonian, as well as to make a quantitative assessment of the validity of a greenhouse climate existing in the mid-Devonian.

A large outbreak of scombroid fish poisoning associated with eating yellowfin tuna (Thunnus albacares) at a military mass catering in Dakar, Senegal.

PubMed

Demoncheaux, J-P; Michel, R; Mazenot, C; Duflos, G; Iacini, C; de Laval, F; Delaval, F; Saware, E M; Renard, J-C

2012-06-01

On 26 November 2010, an outbreak of scombroid fish poisoning occurred in the French Armed Forces in Dakar, Senegal. This chemical intoxication, due to high histamine concentration in fish, is often mistaken for an allergic reaction. A case-control study was undertaken including the 71 cases and 78 randomly selected controls among lunch attendees. The usual symptoms for scombroid fish poisoning were observed in cases, i.e. flushing (85.9%), headache (83.1%), rapid/weak pulse (59.1%) and diarrhoea (47.9%). Symptoms occurred from within a few minutes to up to 3 h following the meal. Most patients quickly recovered with antihistamine and/or symptomatic treatment. Tuna was the only food item positively associated with illness (odds ratio 36.3, 95% confidence interval 6.3-210.0), with the risk of illness increasing with the quantity of fish consumed. No bacterial contamination was found in leftover food, but histamine concentration in tuna was found to be 4900 mg/kg, almost 50-fold higher than the concentration allowed by European regulations. This report is unique because of the large size of the case series - to our knowledge, the largest event of scombroid fish poisoning ever reported - and the chemical and bacteriological analyses results obtained on leftover food.

DHA and EPA Content and Fatty Acid Profile of 39 Food Fishes from India

PubMed Central

Mahanty, Arabinda; Sankar, T. V.; Anandan, R.; Paul, B. N.; Sarma, Debajit; Syama Dayal, J.; Venkateshwarlu, G.; Mathew, Suseela; Karunakaran, D.; Chanda, Soumen; Shahi, Neetu; Das, Puspita; Das, Partha; Akhtar, Md Shahbaz; Vijayagopal, P.; Sridhar, N.

2016-01-01

Docosahexaenoic acid (DHA) is the principal constituent of a variety of cells especially the brain neurons and retinal cells and plays important role in fetal brain development, development of motor skills, and visual acuity in infants, lipid metabolism, and cognitive support and along with eicosapentaenoic acid (EPA) it plays important role in preventing atherosclerosis, dementia, rheumatoid arthritis, Alzheimer's disease, and so forth. Being an essential nutrient, it is to be obtained through diet and therefore searching for affordable sources of these ω-3 polyunsaturated fatty acids (PUFA) is important for consumer guidance and dietary counseling. Fish is an important source of PUFA and has unique advantage that there are many food fish species available and consumers have a wide choice owing to availability and affordability. The Indian subcontinent harbors a rich fish biodiversity which markedly varies in their nutrient composition. Here we report the DHA and EPA content and fatty acid profile of 39 important food fishes (including finfishes, shellfishes, and edible molluscs from both marine water and freshwater) from India. The study showed that fishes Tenualosa ilisha, Sardinella longiceps, Nemipterus japonicus, and Anabas testudineus are rich sources of DHA and EPA. Promotion of these species as DHA rich species would enhance their utility in public health nutrition. PMID:27579313

Taxonomic composition and endemism of the helminth fauna of freshwater fishes of Mexico.

PubMed

Salgado-Maldonado, Guillermo; Quiroz-Martínez, Benjamín

2013-01-01

We examine the taxonomic composition and endemism of adult helminth parasites of freshwater fishes of Mexico, with regard to the main hydrological basins of the country. A presence-absence matrix, including every species of adult helminth parasites of freshwater fishes from 23 Mexican hydrological basins was compiled and examined in this paper. The helminth fauna of freshwater fishes of Mexico consists of a large group of Central American Neotropical species (S = 119) and another set, less rich of Nearctic species (S = 48), which are distributed along with the families of its fish hosts; insufficient data preclude the assignation of three species. This fauna is composed predominantly by nematodes, trematodes, and monogeneans, which together contributed 86 % of the total species recorded; cestodes and acanthocephalans being the taxa with the least species recorded. Current data suggests a 22 % (37/170) endemism amongst helminths of freshwater fishes of Mexico. Data suggests that the isolation of bodies of water in the Mexican territory, mostly in the Neotropical areas of southeastern Mexico and in the central Altiplano Mexicano (Mexican Highland Plateau), with well delimited basins separated by orographic features, provided peculiar conditions that have been conducive to the diversification of a unique helminth fauna.

DHA and EPA Content and Fatty Acid Profile of 39 Food Fishes from India.

PubMed

Mohanty, Bimal Prasanna; Ganguly, Satabdi; Mahanty, Arabinda; Sankar, T V; Anandan, R; Chakraborty, Kajal; Paul, B N; Sarma, Debajit; Syama Dayal, J; Venkateshwarlu, G; Mathew, Suseela; Asha, K K; Karunakaran, D; Mitra, Tandrima; Chanda, Soumen; Shahi, Neetu; Das, Puspita; Das, Partha; Akhtar, Md Shahbaz; Vijayagopal, P; Sridhar, N

2016-01-01

Docosahexaenoic acid (DHA) is the principal constituent of a variety of cells especially the brain neurons and retinal cells and plays important role in fetal brain development, development of motor skills, and visual acuity in infants, lipid metabolism, and cognitive support and along with eicosapentaenoic acid (EPA) it plays important role in preventing atherosclerosis, dementia, rheumatoid arthritis, Alzheimer's disease, and so forth. Being an essential nutrient, it is to be obtained through diet and therefore searching for affordable sources of these ω-3 polyunsaturated fatty acids (PUFA) is important for consumer guidance and dietary counseling. Fish is an important source of PUFA and has unique advantage that there are many food fish species available and consumers have a wide choice owing to availability and affordability. The Indian subcontinent harbors a rich fish biodiversity which markedly varies in their nutrient composition. Here we report the DHA and EPA content and fatty acid profile of 39 important food fishes (including finfishes, shellfishes, and edible molluscs from both marine water and freshwater) from India. The study showed that fishes Tenualosa ilisha, Sardinella longiceps, Nemipterus japonicus, and Anabas testudineus are rich sources of DHA and EPA. Promotion of these species as DHA rich species would enhance their utility in public health nutrition.

Conifer density within lake catchments predicts fish mercury concentrations in remote subalpine lakes

USGS Publications Warehouse

Eagles-Smith, Collin A.; Herring, Garth; Johnson, Branden L.; Graw, Rick

2016-01-01

Remote high-elevation lakes represent unique environments for evaluating the bioaccumulation of atmospherically deposited mercury through freshwater food webs, as well as for evaluating the relative importance of mercury loading versus landscape influences on mercury bioaccumulation. The increase in mercury deposition to these systems over the past century, coupled with their limited exposure to direct anthropogenic disturbance make them useful indicators for estimating how changes in mercury emissions may propagate to changes in Hg bioaccumulation and ecological risk. We evaluated mercury concentrations in resident fish from 28 high-elevation, sub-alpine lakes in the Pacific Northwest region of the United States. Fish total mercury (THg) concentrations ranged from 4 to 438 ng/g wet weight, with a geometric mean concentration (±standard error) of 43 ± 2 ng/g ww. Fish THg concentrations were negatively correlated with relative condition factor, indicating that faster growing fish that are in better condition have lower THg concentrations. Across the 28 study lakes, mean THg concentrations of resident salmonid fishes varied as much as 18-fold among lakes. We used a hierarchal statistical approach to evaluate the relative importance of physiological, limnological, and catchment drivers of fish Hg concentrations. Our top statistical model explained 87% of the variability in fish THg concentrations among lakes with four key landscape and limnological variables: catchment conifer density (basal area of conifers within a lake's catchment), lake surface area, aqueous dissolved sulfate, and dissolved organic carbon. Conifer density within a lake's catchment was the most important variable explaining fish THg concentrations across lakes, with THg concentrations differing by more than 400 percent across the forest density spectrum. These results illustrate the importance of landscape characteristics in controlling mercury bioaccumulation in fish.

Conifer density within lake catchments predicts fish mercury concentrations in remote subalpine lakes.

PubMed

Eagles-Smith, Collin A; Herring, Garth; Johnson, Branden; Graw, Rick

2016-05-01

Remote high-elevation lakes represent unique environments for evaluating the bioaccumulation of atmospherically deposited mercury through freshwater food webs, as well as for evaluating the relative importance of mercury loading versus landscape influences on mercury bioaccumulation. The increase in mercury deposition to these systems over the past century, coupled with their limited exposure to direct anthropogenic disturbance make them useful indicators for estimating how changes in mercury emissions may propagate to changes in Hg bioaccumulation and ecological risk. We evaluated mercury concentrations in resident fish from 28 high-elevation, sub-alpine lakes in the Pacific Northwest region of the United States. Fish total mercury (THg) concentrations ranged from 4 to 438 ng/g wet weight, with a geometric mean concentration (±standard error) of 43 ± 2 ng/g ww. Fish THg concentrations were negatively correlated with relative condition factor, indicating that faster growing fish that are in better condition have lower THg concentrations. Across the 28 study lakes, mean THg concentrations of resident salmonid fishes varied as much as 18-fold among lakes. We used a hierarchal statistical approach to evaluate the relative importance of physiological, limnological, and catchment drivers of fish Hg concentrations. Our top statistical model explained 87% of the variability in fish THg concentrations among lakes with four key landscape and limnological variables: catchment conifer density (basal area of conifers within a lake's catchment), lake surface area, aqueous dissolved sulfate, and dissolved organic carbon. Conifer density within a lake's catchment was the most important variable explaining fish THg concentrations across lakes, with THg concentrations differing by more than 400 percent across the forest density spectrum. These results illustrate the importance of landscape characteristics in controlling mercury bioaccumulation in fish. Published by Elsevier Ltd.

Using industry ROV videos to assess fish associations with subsea pipelines

NASA Astrophysics Data System (ADS)

McLean, D. L.; Partridge, J. C.; Bond, T.; Birt, M. J.; Bornt, K. R.; Langlois, T. J.

2017-06-01

Remote Operated Vehicles are routinely used to undertake inspection and maintenance activities of underwater pipelines in north-west Australia. In doing so, many terabytes of geo-referenced underwater video are collected at depths, and on a scale usually unobtainable for ecological research. We assessed fish diversity and abundance from existing ROV videos collected along 2-3 km sections of two pipelines in north-west Australia, one at 60-80 m water depth and the other at 120-130 m. A total of 5962 individual fish from 92 species and 42 families were observed. Both pipelines were characterised by a high abundance of commercially important fishes including: snappers (Lutjanidae) and groupers (Epinephelidae). The presence of thousands of unidentifiable larval fish, in addition to juveniles, sub-adults and adults suggests that the pipelines may be enhancing, rather than simply attracting, fish stocks. The prevalence and high complexity of sponges on the shallower pipeline and of deepwater corals on the deeper pipeline had a strong positive correlation with the fish abundance. These habitats likely offer a significant food source and refuge for fish, but also for invertebrates upon which fish feed. A greater diversity on the shallower pipeline, and a higher abundance of fishes on both pipelines, were associated with unsupported pipeline sections (spans) and many species appeared to be utilising pipeline spans as refuges. This study is a first look at the potential value of subsea pipelines for fishes on the north-west shelf. While the results suggest that these sections of pipeline appear to offer significant habitat that supports diverse and important commercially fished species, further work, including off-pipeline surveys on the natural seafloor, are required to determine conclusively the ecological value of pipelines and thereby inform discussions regarding the ecological implications of pipeline decommissioning.

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

USGS Publications Warehouse

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.

Hydrologic filtering of fish life history strategies across the United States: implications for stream flow alteration

DOE PAGES

McManamay, Ryan A.; Frimpong, Emmanuel A.

2015-01-01

Lotic fish have developed life history strategies adapted to the natural variation in stream flow regimes. The natural timing, duration, and magnitude of flow events has contributed to the diversity, production, and composition of fish assemblages over time. Studies evaluating the role of hydrology in structuring fish assemblages have been more common at the local or regional scale with very few studies conducted at the continental scale. Furthermore, quantitative linkages between natural hydrologic patterns and fish assemblages are rarely used to make predictions of ecological consequences of hydrologic alterations. We ask two questions: (1) what is the relative role ofmore » hydrology in structuring fish assemblages at large scales? and (2) can relationships between fish assemblages and natural hydrology be utilized to predict fish assemblage responses to hydrologic disturbance? We developed models to relate fish life histories and reproductive strategies to landscape and hydrologic variables separately and then combined. Models were then used to predict the ecological consequences of altered hydrology due to dam regulation. Although hydrology plays a considerable role in structuring fish assemblages, the performance of models using only hydrologic variables was lower than that of models constructed using landscape variables. Isolating the relative importance of hydrology in structuring fish assemblages at the continental scale is difficult since hydrology is interrelated to many landscape factors. By applying models to dam-regulated hydrologic data, we observed some consistent predicted responses in fish life history strategies and modes of reproduction. In agreement with existing literature, equilibrium strategists are predicted to increase following dam regulation, whereas opportunistic and periodic species are predicted to decrease. In addition, dam regulation favors the selection of reproductive strategies with extended spawning seasons and preference for stable conditions.« less

Hydrologic filtering of fish life history strategies across the United States: implications for stream flow alteration

DOE Office of Scientific and Technical Information (OSTI.GOV)

McManamay, Ryan A.; Frimpong, Emmanuel A.

Lotic fish have developed life history strategies adapted to the natural variation in stream flow regimes. The natural timing, duration, and magnitude of flow events has contributed to the diversity, production, and composition of fish assemblages over time. Studies evaluating the role of hydrology in structuring fish assemblages have been more common at the local or regional scale with very few studies conducted at the continental scale. Furthermore, quantitative linkages between natural hydrologic patterns and fish assemblages are rarely used to make predictions of ecological consequences of hydrologic alterations. We ask two questions: (1) what is the relative role ofmore » hydrology in structuring fish assemblages at large scales? and (2) can relationships between fish assemblages and natural hydrology be utilized to predict fish assemblage responses to hydrologic disturbance? We developed models to relate fish life histories and reproductive strategies to landscape and hydrologic variables separately and then combined. Models were then used to predict the ecological consequences of altered hydrology due to dam regulation. Although hydrology plays a considerable role in structuring fish assemblages, the performance of models using only hydrologic variables was lower than that of models constructed using landscape variables. Isolating the relative importance of hydrology in structuring fish assemblages at the continental scale is difficult since hydrology is interrelated to many landscape factors. By applying models to dam-regulated hydrologic data, we observed some consistent predicted responses in fish life history strategies and modes of reproduction. In agreement with existing literature, equilibrium strategists are predicted to increase following dam regulation, whereas opportunistic and periodic species are predicted to decrease. In addition, dam regulation favors the selection of reproductive strategies with extended spawning seasons and preference for stable conditions.« less

Reduced reproductive success of hatchery coho salmon in the wild: insights into most likely mechanisms.

PubMed

Thériault, Véronique; Moyer, Gregory R; Jackson, Laura S; Blouin, Michael S; Banks, Michael A

2011-05-01

Supplementation of wild salmonids with captive-bred fish is a common practice for both commercial and conservation purposes. However, evidence for lower fitness of captive-reared fish relative to wild fish has accumulated in recent years, diminishing the apparent effectiveness of supplementation as a management tool. To date, the mechanism(s) responsible for these fitness declines remain unknown. In this study, we showed with molecular parentage analysis that hatchery coho salmon (Oncorhynchus kisutch) had lower reproductive success than wild fish once they reproduced in the wild. This effect was more pronounced in males than in same-aged females. Hatchery spawned fish that were released as unfed fry (age 0), as well as hatchery fish raised for one year in the hatchery (released as smolts, age 1), both experienced lower lifetime reproductive success (RS) than wild fish. However, the subset of hatchery males that returned as 2-year olds (jacks) did not exhibit the same fitness decrease as males that returned as 3-year olds. Thus, we report three lines of evidence pointing to the absence of sexual selection in the hatchery as a contributing mechanism for fitness declines of hatchery fish in the wild: (i) hatchery fish released as unfed fry that survived to adulthood still had low RS relative to wild fish, (ii) age-3 male hatchery fish consistently showed a lower relative RS than female hatchery fish (suggesting a role for sexual selection), and (iii) age-2 jacks, which use a sneaker mating strategy, did not show the same declines as 3-year olds, which compete differently for females (again, implicating sexual selection). © 2011 Blackwell Publishing Ltd.

Fathead minnow and bluegill sunfish life-stage responses to 17β-estradiol exposure in outdoor mesocosms

USGS Publications Warehouse

Elliott, Sarah M.; Kiesling, Richard L.; Jorgenson, Zachary G.; Rearick, Daniel C.; Schoenfuss, Heiko L.; Fredricks, Kim T.; Gaikowski, Mark P.

2014-01-01

Developmental and reproductive effects of 17β-estradiol (E2) exposure on two generations of fathead minnows and one generation of bluegill sunfish were assessed. Fish were exposed to E2 for six continuous weeks in outdoor mesocosms simulating natural lake environments. First generation fish were exposed while sexually mature. Second generation fathead minnows were exposed either during early development, sexual maturity, or both stages. Multiple endpoints were measured to assess effects of E2 exposure on fecundity and fish health and development. Plasma vitellogenin concentrations were highly variable in all fish. Differences in egg production timing for both species indicate differences in fecundity between females exposed to E2 and controls. First generation fathead minnows exposed to E2 had lower body condition factors and reduced secondary sexual characteristic expression by males. Only a difference in relative liver weight was observed in second generation fathead minnows. First generation bluegill males exposed to E2 had significantly smaller testes compared to controls. Although fish response was highly variable, results indicate that exposure to E2 at environmentally relevant concentrations affect fathead minnow and bluegill sunfish health and development, which may have implications for the health and sustainability of fish populations. Furthermore, exposure timing and environmental factors affect fish response to E2 exposure.

Autonomous Soft Robotic Fish Capable of Escape Maneuvers Using Fluidic Elastomer Actuators.

PubMed

Marchese, Andrew D; Onal, Cagdas D; Rus, Daniela

2014-03-01

In this work we describe an autonomous soft-bodied robot that is both self-contained and capable of rapid, continuum-body motion. We detail the design, modeling, fabrication, and control of the soft fish, focusing on enabling the robot to perform rapid escape responses. The robot employs a compliant body with embedded actuators emulating the slender anatomical form of a fish. In addition, the robot has a novel fluidic actuation system that drives body motion and has all the subsystems of a traditional robot onboard: power, actuation, processing, and control. At the core of the fish's soft body is an array of fluidic elastomer actuators. We design the fish to emulate escape responses in addition to forward swimming because such maneuvers require rapid body accelerations and continuum-body motion. These maneuvers showcase the performance capabilities of this self-contained robot. The kinematics and controllability of the robot during simulated escape response maneuvers are analyzed and compared with studies on biological fish. We show that during escape responses, the soft-bodied robot has similar input-output relationships to those observed in biological fish. The major implication of this work is that we show soft robots can be both self-contained and capable of rapid body motion.

Phenotypic and genotypic heterogeneity among Streptococcus iniae isolates recovered from cultured and wild fish in North America, Central America and the Caribbean islands.

PubMed

Chou, Lucy; Griffin, Matt J; Fraites, Trellor; Ware, Cynthia; Ferguson, Hugh; Keirstead, Natalie; Brake, John; Wiles, Judy; Hawke, John P; Kearney, Michael T; Getchell, Rodman G; Gaunt, Patricia; Soto, Esteban

2014-12-01

Streptococcus iniae, the etiological agent of streptococcosis in fish, is an important pathogen of cultured and wild fish worldwide. During the last decade outbreaks of streptococcosis have occurred in a wide range of cultured and wild fish in the Americas and Caribbean islands. To gain a better understanding of the epizootiology of S. iniae in the western hemisphere, over 30 S. iniae isolates recovered from different fish species and geographic locations were characterized phenotypically and genetically. Species identities were determined biochemically and confirmed by amplification and sequencing of the 16S rRNA gene. Repetitive-element palindromic PCR fingerprinting as well as biochemical and antimicrobial susceptibility profiles suggest that a single strain of S. iniae was responsible for two different disease outbreaks among reef fishes in the Caribbean, one in 1999 and another in 2008. Interestingly, a majority of the isolates recovered from cultured fish in the Americas were genetically distinct from the Caribbean isolates and exhibited a trend toward higher minimal inhibitory concentration with respect to several antibiotics as well as greater genetic variability. The biological significance of this genetic variability is unclear, but it could have implications for future vaccine development and treatment.

Epidemiology and Clinical Features of Ciguatera Fish Poisoning in Hong Kong

PubMed Central

Chan, Thomas Y. K.

2014-01-01

In the present review, the main objective was to describe the epidemiology and clinical features of ciguatera fish poisoning in Hong Kong. From 1989 to 2008, the annual incidence of ciguatera varied between 3.3 and 64.9 (median 10.2) per million people. The groupers have replaced the snappers as the most important cause of ciguatera. Pacific-ciguatoxins (CTX) are most commonly present in reef fish samples implicated in ciguatera outbreaks. In affected subjects, the gastrointestinal symptoms often subside within days, whereas the neurological symptoms can persist for weeks or even months. Bradycardia and hypotension, which can be life-threatening, are common. Treatment of ciguatera is primarily supportive and symptomatic. Intravenous mannitol (1 g/kg) has also been suggested. To prevent ciguatera outbreaks, the public should be educated to avoid eating large coral reef fishes, especially the CTX-rich parts. A Code of Practice on Import and Sale of Live Marine Fish for Human Consumption for Prevention and Control of Ciguatera Fish Poisoning was introduced from 2004 to 2013. The Food Safety Ordinance with a tracing mechanism came into full effect in February 2012. The Government would be able to trace the sources of the fishes more effectively and take prompt action when dealing with ciguatera incidents. PMID:25333356

Epidemiology and clinical features of ciguatera fish poisoning in Hong Kong.

PubMed

Chan, Thomas Y K

2014-10-20

In the present review, the main objective was to describe the epidemiology and clinical features of ciguatera fish poisoning in Hong Kong. From 1989 to 2008, the annual incidence of ciguatera varied between 3.3 and 64.9 (median 10.2) per million people. The groupers have replaced the snappers as the most important cause of ciguatera. Pacific-ciguatoxins (CTX) are most commonly present in reef fish samples implicated in ciguatera outbreaks. In affected subjects, the gastrointestinal symptoms often subside within days, whereas the neurological symptoms can persist for weeks or even months. Bradycardia and hypotension, which can be life-threatening, are common. Treatment of ciguatera is primarily supportive and symptomatic. Intravenous mannitol (1 g/kg) has also been suggested. To prevent ciguatera outbreaks, the public should be educated to avoid eating large coral reef fishes, especially the CTX-rich parts. A Code of Practice on Import and Sale of Live Marine Fish for Human Consumption for Prevention and Control of Ciguatera Fish Poisoning was introduced from 2004 to 2013. The Food Safety Ordinance with a tracing mechanism came into full effect in February 2012. The Government would be able to trace the sources of the fishes more effectively and take prompt action when dealing with ciguatera incidents.

Spatial structuring within a reservoir fish population: implications for management

USGS Publications Warehouse

Stewart, David R.; Long, James M.; Shoup, Daniel E.

2014-01-01

Spatial structuring in reservoir fish populations can exist because of environmental gradients, species-specific behaviour, or even localised fishing effort. The present study investigated whether white crappie exhibited evidence of improved population structure where the northern more productive half of a lake is closed to fishing to provide waterfowl hunting opportunities. Population response to angling was modelled for each substock of white crappie (north (protected) and south (unprotected) areas), the entire lake (single-stock model) and by combining simulations of the two independent substock models (additive model). White crappie in the protected area were more abundant, consisting of larger, older individuals, and exhibited a lower total annual mortality rate than in the unprotected area. Population modelling found that fishing mortality rates between 0.1 and 0.3 resulted in sustainable populations (spawning potential ratios (SPR) >0.30). The population in the unprotected area appeared to be more resilient (SPR > 0.30) at the higher fishing intensities (0.35–0.55). Considered additively, the whole-lake fishery appeared more resilient than when modelled as a single-panmictic stock. These results provided evidence of spatial structuring in reservoir fish populations, and we recommend model assessments used to guide management decisions should consider those spatial differences in other populations where they exist.

Factors influencing tropical island freshwater fishes:Species, status, and management implications in puerto rico [Factores que influencian a los peces tropicales de agua dulce: Especies, estado actual e implicaciones para el manejo en Puerto Rico

USGS Publications Warehouse

Wesley, Neal J.; Lilyestrom, Craig G.; Kwak, T.J.

2009-01-01

Anthropogenic effects including river regulation, watershed development, contamination, and fish introductions have substantially affected the majority of freshwater habitats in Europe and North America. This pattern of resource development and degradation is widespread in the tropics, and often little is known about the resources before they are lost. This article describes the freshwater resources of Puerto Rico and identifies factors that threaten conservation of native fishes. The fishes found in freshwater habitats of Puerto Rico represent a moderately diverse assemblage composed of 14 orders, 29 families, and 82 species. There are fewer than 10 species of native peripherally-freshwater fish that require a link to marine systems. Introductions of nonindigenous species have greatly expanded fish diversity in freshwater systems, and native estuarine and marine species (18 families) also commonly enter lowland rivers and brackish lagoons. Environmental alterations, including land use and development, stream channelization, pollution, and the impoundment of rivers, combined with nonnative species introductions threaten the health and sustainability of aquatic resources in Puerto Rico. Six principal areas for attention that are important influences on the current and future status of the freshwater fish resources of Puerto Rico are identified and discussed.

The Effect of Elevated CO2 and Temperature on the Hatch Rate and Survival of Estuarine Forage Fish

NASA Astrophysics Data System (ADS)

Merlo, L. R.; Gobler, C.

2016-02-01

The World Oceans are acidifying and warming, yet little is known regarding how these processes will combine to impact fish populations. In estuaries, microbial respiration of eutrophication-enhanced organic matter can create elevated CO2 levels during late spring and summer seasons when thermal extremes can occur and temperate fish spawn. Here, we report on experiments that exposed fish embryos (e.g. Menidia beryllina, inland silverside) to normal and elevated CO2 (400 and 2,000 ppm) and the range of temperatures experienced within temperate estuaries during the spawning season (16 - 30C). Fish survival and growth rates were quantified from hatching through early life, larval stages. Temperature controlled egg hatching times, with elevated temperatures leading to more rapid hatch rates. Elevated levels of CO2 significantly depressed post-hatch survival of fish. Survival rates of fish exposed to elevated CO2 at lower than ideal temperatures were significantly lower than predicted by either variable individually indicating the ability of these stressors to synergistically interact. Since embryonic stages have been identified as being highly sensitive to acidification, this finding may be associated with the extended exposure of eggs to high CO2 at lower temperatures. The physiological mechanisms driving experimental trends and broader ecological implications of the study will be discussed.

Fisheries impacts on China's coastal ecosystems: Unmasking a pervasive ‘fishing down’ effect

PubMed Central

Pauly, Daniel

2017-01-01

Intensive fishing can strongly impact marine ecosystems; among other things, it usually causes the mean trophic level of the catches to decline, an indicator of the occurrence of the ‘fishing down’ (FD) phenomenon. Although FD occurs throughout the world oceans, it can easily be masked by diverse factors, which has misled authors as to its generality. In this contribution, which uses the East China Sea as an example, we explore the masking effect on FD of the taxonomic coarseness of catch data, of assuming that individual sizes remain constant after intensive fishing, and the geographic expansion of fisheries. The result showed that all of these masking factors occur in the East China Sea, where only a few species are reported separately and the bulk of the catch is pooled into non-informative ‘mixed fishes’. Also, the small mesh sizes and intensive fishing have reduced the sizes of fish and their trophic levels, while the fisheries have expanded offshore. Overall, taking the masking factors into account, the fishing down effect, i.e., the decline of the mean trophic level of the catch between 1979 and 2014 is in the order of 0.15 TL per decade, i.e., one of the highest estimates of FD in the world. Some ecological implications are presented. PMID:28267755

Rapid Evolution of piRNA Pathway in the Teleost Fish: Implication for an Adaptation to Transposon Diversity

PubMed Central

Yi, Minhan; Chen, Feng; Luo, Majing; Cheng, Yibin; Zhao, Huabin; Cheng, Hanhua; Zhou, Rongjia

2014-01-01

The Piwi-interacting RNA (piRNA) pathway is responsible for germline specification, gametogenesis, transposon silencing, and genome integrity. Transposable elements can disrupt genome and its functions. However, piRNA pathway evolution and its adaptation to transposon diversity in the teleost fish remain unknown. This article unveils evolutionary scene of piRNA pathway and its association with diverse transposons by systematically comparative analysis on diverse teleost fish genomes. Selective pressure analysis on piRNA pathway and miRNA/siRNA (microRNA/small interfering RNA) pathway genes between teleosts and mammals showed an accelerated evolution of piRNA pathway genes in the teleost lineages, and positive selection on functional PAZ (Piwi/Ago/Zwille) and Tudor domains involved in the Piwi–piRNA/Tudor interaction, suggesting that the amino acid substitutions are adaptive to their functions in piRNA pathway in the teleost fish species. Notably five piRNA pathway genes evolved faster in the swamp eel, a kind of protogynous hermaphrodite fish, than the other teleosts, indicating a differential evolution of piRNA pathway between the swamp eel and other gonochoristic fishes. In addition, genome-wide analysis showed higher diversity of transposons in the teleost fish species compared with mammals. Our results suggest that rapidly evolved piRNA pathway in the teleost fish is likely to be involved in the adaption to transposon diversity. PMID:24846630

How to catch a parasite: Parasite Niche Modeler (PaNic) meets Fishbase

USGS Publications Warehouse

Strona, Giovanni; Lafferty, Kevin D.

2012-01-01

Parasite Niche Modeler (PaNic) is a free online software tool that suggests potential hosts for fish parasites. For a particular parasite species from the major helminth groups (Acanthocephala, Cestoda, Monogenea, Nematoda, Trematoda), PaNic takes data from known hosts (maximum body length, growth rate, life span, age at first maturity, trophic level, phylogeny, and biogeography) and hypothesizes similar fish species that might serve as hosts to that parasite. Users can give varying weights to host attributes and create custom models. In addition to suggesting plausible hosts (with varying degrees of confidence), the models indicate known host species that appear to be outliers in comparison to other known hosts. These unique features make PaNic an innovative tool for addressing both theoretical and applied questions in fish parasitology. PaNic can be accessed at .

Stakeholder participation in research design and decisions: scientists, fishers, and mercury in saltwater fish.

PubMed

Burger, Joanna; Gochfeld, Michael; Fote, Tom

2013-03-01

Individuals who fish and eat self-caught fish make decisions about where to fish, the type to eat, and the quantity to eat. Federal and state agencies often issue consumption advisories for some fish with high mercury (Hg) concentrations, but seldom provide either the actual metal levels to the general public, or identify the fish that have low contaminant levels. Community participatory research is of growing importance in defining, studying, and resolving complex exposure and risk issues, and this paper is at the intersection of traditional stakeholder approaches and community-based participatory research. The objective of this paper is to describe the process whereby stakeholders (fishers), were involved in directing and refining research questions to address their particular informational needs about mercury levels in fish, potential risks, and methods to maintain health, by balancing the risks and benefits of fish consumption. A range of stakeholders, mainly individual fishers, fishing organizations, and other scientists, were involved at nearly every stage. Community participants influenced many aspects of the design and implementation of the research, in the determination of which fish species to sample, in the collection of the samples, and in the final analyses and synthesis, as well as the communication of results and implications of the research through their fishing club publications, talks and gatherings. By involving the most interested and affected communities, the data and conclusions are relevant to their needs because the fish examined were those they ate and wanted information about, and directly address concerns about the risk from consuming self-caught fish. Although mercury levels in fish presumed to be high in mercury are known, little information was available to the fishermen on mercury levels in fish that were low and thus provided little risk to their families. While community participatory research is more time-consuming and expensive than traditional scientific research, both the process and results are better scientifically in terms of community relevance.

Stakeholder Participation in Research Design and Decisions: Scientists, Fishers, and Mercury in Saltwater Fish

PubMed Central

Burger, Joanna; Gochfeld, Michael; Fote, Tom

2015-01-01

Individuals who fish and eat self-caught fish make decisions about where to fish, the type to eat, and the quantity to eat. Federal and state agencies often issue consumption advisories for some fish with high mercury (Hg) concentrations, but seldom provide either the actual metal levels to the general public, or identify the fish that have low contaminant levels. Community participatory research is of growing importance in defining, studying, and resolving complex exposure and risk issues, and this paper is at the intersection of traditional stakeholder approaches and community-based participatory research. The objective of this paper is to describe the process whereby stakeholders (fishers), were involved in directing and refining research questions to address their particular informational needs about mercury levels in fish, potential risks, and methods to maintain health, by balancing the risks and benefits of fish consumption. A range of stakeholders, mainly individual fishers, fishing organizations, and other scientists, were involved at nearly every stage. Community participants influenced many aspects of the design and implementation of the research, in the determination of which fish species to sample, in the collection of the samples, and in the final analyses and synthesis, as well as the communication of results and implications of the research through their fishing club publications, talks and gatherings. By involving the most interested and affected communities, the data and conclusions are relevant to their needs because the fish examined were those they ate and wanted information about, and directly address concerns about the risk from consuming self-caught fish. Although mercury levels in fish presumed to be high in mercury are known, little information was available to the fishermen on mercury levels in fish that were low and thus provided little risk to their families. While community participatory research is more time-consuming and expensive than traditional scientific research, both the process and results are better scientifically I in terms of community relevance. PMID:23413085

Local variability in metazoan parasites of the pelagic fish species, Engraulis ringens: implications for fish stock assessment using parasites as biological tags.

PubMed

Chavez, Rosa A; Valdivia, Isabel M; Oliva, Marcelo E

2007-06-01

Parasites have been used successfully as biological tags in population studies, mainly in marine fishes, but also in marine mammals, crustaceans and molluscs. Almost all published information dealing with parasites as biological tags evaluates differences between localities. However, local variability in the component community has not been assessed. In this work, we examined whether local variation of the metazoan parasite fauna of Engraulis ringens, extracted from five independent samples from two nearby localities in northern Chile, can be a factor causing bias in stock identification. Our results show that local variability, as estimated by a single sample, may suffice to represent component community variability with no need for replicated data.

Polybrominated diphenyl ethers (PBDEs) in Great Lakes fish: Levels, patterns, trends and implications for human exposure.

PubMed

Gandhi, Nilima; Gewurtz, Sarah B; Drouillard, Ken G; Kolic, Terry; MacPherson, Karen; Reiner, Eric J; Bhavsar, Satyendra P

2017-01-15

Levels of polybrominated diphenyl ethers (PBDEs) were measured in edible portions of Great Lakes fish, with the goal of examining patterns/trends and evaluating implications for human exposure. A total of 470 fillets of 18 fish species collected from various parts of the Canadian waters of the Great Lakes between 2006 and 2013 were analyzed for 17 (expanded to 33 in 2009) PBDEs. For a limited number of species, fillet to whole body and fillet to eggs PBDEs were compared to examine pattern and concentration among tissue types. Levels and patterns of PBDEs varied dramatically within and among the 18 fish species. Bottom dwelling Common Carp (and White Sucker) exhibited the highest ∑PBDE levels (27-71ng/g). Lake Trout and Lake Whitefish from Lake Superior had higher levels than those from the other Great Lakes; otherwise the spatial trend was Lake Ontario≫Erie~Huron~Superior. The measured levels would result in restriction on consumption of only Common Carp from the Toronto waterfront area, which is in proximity to the most urbanised region on the Canadian side of the basin. Deca-BDE was the major congener in panfish, while BDE-47 was the major congener in top predators and its contribution to ∑PBDE increased with the contamination. Although ∑PBDE was related to fish length and lipid content when all measurements were pooled, the relationships were variable for individual sampling events (species/location/year). Whole body ∑PBDE for bottom dweller Brown Bullhead and Common Carp were 2.6-4.9 times greater and egg ∑PBDE for four fatty Salmon/Trout species were same to 6.5 times greater than the corresponding fillet concentrations. Levels of major lower brominated PBDEs appear to have declined in fish fillets by 46-74% between 2006/07 and 2012. Although PBDE in existing consumer items will remain in-use for a while, it will likely not result in appreciable accumulation of PBDEs in fish. Based on an overall assessment, regular monitoring of PBDEs in Great Lake fish can be replaced with targeted surveillance and focus can be shifted to other in-use flame retardants. Crown Copyright © 2016. Published by Elsevier B.V. All rights reserved.

Acculturation and Dietary Intakes by Gender Among Mongolians in South Korea: Nutrition Education Implication for Multicultural Families.

PubMed

Park, Hae Ryun; Tserendejid, Zuunnast; Lee, Joung Hee; Lim, Young Suk

2017-10-01

We explored the relationship between acculturation and dietary intake by gender for 500 Mongolians residing in South Korea. The high acculturation (HA) group females consumed more fish and shellfish, vegetables, beans, and rice, and less meats, flours, and oil than the low acculturation (LA) group did. However, there was no statistical difference in food group intake between HA and LA group males. HA group females showed higher intake of carbohydrates, fiber, sodium, potassium, calcium, vitamin A, and folate compared with LA group females. However, only folate and vitamin B2 intake was statistically different between HA and LA group males. Acculturation and gender interactions were found for the consumption of meats, flours, fish and shellfish, beans, and vegetables. The findings from this study have implications for developing customized nutrition intervention programs by gender for immigrants.

Something fishy? News media presentation of complex health issues related to fish consumption guidelines.

PubMed

Greiner, Amelia; Clegg Smith, Katherine; Guallar, Eliseo

2010-11-01

The news media are an important source of dietary information. Understanding news content, particularly the portrayal of risks and benefits of certain foods, is relevant for effective public health communication. Fish consumption may reduce risk for CVD and aid neonatal development, but recent work shows public confusion about the benefits of fish, challenged by the evidence of mercury and other contaminants in fish. We present an analysis of the messages about fish in US news media over 15 years, identifying trends in coverage and highlighting implications of current messaging. We conducted a descriptive text analysis and coded for manifest content: locality of focus, story frame, reference to studies, inclusion of government guidelines and portrayal of uncertainty. We identified chronological patterns and analysed the data for statistically significant relationships between media source and content. News stories were selected from five daily newspapers and five television networks (1993-2007). We analysed 310 health-related news stories on fish. Risk messages outweighed benefit messages four to one, and health benefits only became prominent after 2002. No difference existed in coverage topic by news source. Fish consumption has increasingly become a national issue. With the bulk of messages about fish consumption focused on risk, the benefits may be lost to consumers. This gap creates a need for public health to work with news media to more effectively communicate benefits and risks around fish consumption and health and to consider options for communicating tailored information where it can be more readily utilised.

Fish mercury increase in Lago Manso, a new hydroelectric reservoir in tropical Brazil.

PubMed

Hylander, Lars D; Gröhn, Janina; Tropp, Magdalena; Vikström, Anna; Wolpher, Henriette; de Castro E Silva, Edinaldo; Meili, Markus; Oliveira, Lázaro J

2006-10-01

It has been frequently demonstrated that mercury (Hg) concentrations in fish rise in newly constructed hydroelectric reservoirs in the Northern Hemisphere. In the present work, we studied whether similar effects take place also in a tropical upland reservoir during impoundment and discuss possible causes and implications. Total Hg concentrations in fish and several soil and water parameters were determined before and after flooding at Rio Manso hydroelectric power plant in western Brazil. The Hg concentrations in soil and sediment were within the background levels in the region (22-35 ng g(-1) dry weight). There was a strong positive correlation between Hg and carbon and sulphur in sediment. Predatory fish had total Hg concentrations ranging between 70 and 210 ng g(-1) f.w. 7 years before flooding and between 72 and 755 ng g(-1) f.w. during flooding, but increased to between 216 and 938 ng g(-1) f.w. in the piscivorous and carnivorous species Pseudoplatystoma fasciatum, cachara, and Salminus brasiliensis, dourado, 3 years after flooding. At the same time, concentrations of organic carbon in the water increased and oxygen concentrations decreased, indicating increased decomposition and anoxia as contributing to the increased Hg concentrations in fish. The present fish Hg concentrations in commonly consumed piscivorous species are a threat to the health of the population dependent on fishing in the dam and downstream river for sustenance. Mercury exposure can be reduced by following fish consumption recommendations until fish Hg concentrations decrease to a safe level.

Mercury contamination in fish and human hair from Hainan Island, South China Sea: Implication for human exposure.

PubMed

Liu, Jin-Ling; Xu, Xiang-Rong; Yu, Shen; Cheng, Hefa; Peng, Jia-Xi; Hong, Yi-Guo; Feng, Xin-Bin

2014-11-01

Hair has long been recognized as a good biomarker for human exposure to Hg. The mercury concentrations in 14 species of marine fish and hair samples from 177 coastal residents in Hainan, South China Sea were investigated to assess the status of mercury exposure associated with marine fish consumption. Concentrations of total Hg (THg) and methylmercury (MeHg) in the fish muscles were 0.094 ± 0.008 and 0.066 ± 0.006 μg/gww, respectively, which were far below the limit considered safe for consumption (0.5 μg/g). The average THg concentrations in hair of adults (1.02 ± 0.92 μg/g) were lower than the provisional tolerable weekly intake (PTWI) level of 2.2 μg/g. However, 23.7% of children had a hair THg level exceeding the RfD level of 1μg/g, indicating a great risk of Hg exposure to children via fish consumption. The concentration of THg in hair was significantly correlated with fish consumption but not with gender-specific fish intake. With higher fish consumption frequency, the fishermen had significantly elevated hair Hg levels compared to the students and the other general public, who had similar hair THg levels but different fish consumption patterns, indicating the existence of other sources of Hg exposure to the residents of Hainan Island. Copyright © 2014 Elsevier Inc. All rights reserved.

Colony geometry and structural complexity of the endangered species Acropora cervicornis partly explains the structure of their associated fish assemblage.

PubMed

Agudo-Adriani, Esteban A; Cappelletto, Jose; Cavada-Blanco, Francoise; Croquer, Aldo

2016-01-01

In the past decade, significant efforts have been made to describe fish-habitat associations. However, most studies have oversimplified actual connections between fish assemblages and their habitats by using univariate correlations. The purpose of this study was to identify the features of habitat forming corals that facilitate and influences assemblages of associated species such as fishes. For this we developed three-dimensional models of colonies of Acropora cervicornis to estimate geometry (length and height), structural complexity (i.e., volume, density of branches, etc.) and biological features of the colonies (i.e., live coral tissue, algae). We then correlated these colony characteristics with the associated fish assemblage using multivariate analyses. We found that geometry and complexity were better predictors of the structure of fish community, compared to other variables such as percentage of live coral tissue or algae. Combined, the geometry of each colony explained 40% of the variability of the fish assemblage structure associated with this coral species; 61% of the abundance and 69% of fish richness, respectively. Our study shows that three-dimensional reconstructions of discrete colonies of Acropora cervicornis provides a useful description of the colonial structural complexity and may explain a great deal of the variance in the structure of the associated coral reef fish community. This demonstration of the strongly trait-dependent ecosystem role of this threatened species has important implications for restoration and conservation efforts.

Colony geometry and structural complexity of the endangered species Acropora cervicornis partly explains the structure of their associated fish assemblage

PubMed Central

Cappelletto, Jose; Cavada-Blanco, Francoise; Croquer, Aldo

2016-01-01

In the past decade, significant efforts have been made to describe fish-habitat associations. However, most studies have oversimplified actual connections between fish assemblages and their habitats by using univariate correlations. The purpose of this study was to identify the features of habitat forming corals that facilitate and influences assemblages of associated species such as fishes. For this we developed three-dimensional models of colonies of Acropora cervicornis to estimate geometry (length and height), structural complexity (i.e., volume, density of branches, etc.) and biological features of the colonies (i.e., live coral tissue, algae). We then correlated these colony characteristics with the associated fish assemblage using multivariate analyses. We found that geometry and complexity were better predictors of the structure of fish community, compared to other variables such as percentage of live coral tissue or algae. Combined, the geometry of each colony explained 40% of the variability of the fish assemblage structure associated with this coral species; 61% of the abundance and 69% of fish richness, respectively. Our study shows that three-dimensional reconstructions of discrete colonies of Acropora cervicornis provides a useful description of the colonial structural complexity and may explain a great deal of the variance in the structure of the associated coral reef fish community. This demonstration of the strongly trait-dependent ecosystem role of this threatened species has important implications for restoration and conservation efforts. PMID:27069801

Optimum swimming pathways of fish spawning migrations in rivers

USGS Publications Warehouse

McElroy, Brandon; DeLonay, Aaron; Jacobson, Robert

2012-01-01

Fishes that swim upstream in rivers to spawn must navigate complex fluvial velocity fields to arrive at their ultimate locations. One hypothesis with substantial implications is that fish traverse pathways that minimize their energy expenditure during migration. Here we present the methodological and theoretical developments necessary to test this and similar hypotheses. First, a cost function is derived for upstream migration that relates work done by a fish to swimming drag. The energetic cost scales with the cube of a fish's relative velocity integrated along its path. By normalizing to the energy requirements of holding a position in the slowest waters at the path's origin, a cost function is derived that depends only on the physical environment and not on specifics of individual fish. Then, as an example, we demonstrate the analysis of a migration pathway of a telemetrically tracked pallid sturgeon (Scaphirhynchus albus) in the Missouri River (USA). The actual pathway cost is lower than 105 random paths through the surveyed reach and is consistent with the optimization hypothesis. The implication—subject to more extensive validation—is that reproductive success in managed rivers could be increased through manipulation of reservoir releases or channel morphology to increase abundance of lower-cost migration pathways.

Gene editing tools: state-of-the-art and the road ahead for the model and non-model fishes.

PubMed

Barman, Hirak Kumar; Rasal, Kiran Dashrath; Chakrapani, Vemulawada; Ninawe, A S; Vengayil, Doyil T; Asrafuzzaman, Syed; Sundaray, Jitendra K; Jayasankar, Pallipuram

2017-10-01

Advancements in the DNA sequencing technologies and computational biology have revolutionized genome/transcriptome sequencing of non-model fishes at an affordable cost. This has led to a paradigm shift with regard to our heightened understandings of structure-functional relationships of genes at a global level, from model animals/fishes to non-model large animals/fishes. Whole genome/transcriptome sequencing technologies were supplemented with the series of discoveries in gene editing tools, which are being used to modify genes at pre-determined positions using programmable nucleases to explore their respective in vivo functions. For a long time, targeted gene disruption experiments were mostly restricted to embryonic stem cells, advances in gene editing technologies such as zinc finger nuclease, transcriptional activator-like effector nucleases and CRISPR (clustered regulatory interspaced short palindromic repeats)/CRISPR-associated nucleases have facilitated targeted genetic modifications beyond stem cells to a wide range of somatic cell lines across species from laboratory animals to farmed animals/fishes. In this review, we discuss use of different gene editing tools and the strategic implications in fish species for basic and applied biology research.

Region specific changes in nonapeptide levels during client fish interactions with allopatric and sympatric cleaner fish

PubMed Central

Soares, Marta C.; Cardoso, Sónia C.; Mazzei, Renata; André, Gonçalo I.; Morais, Marta; Gozdowska, Magdalena; Kalamarz-Kubiak, Hanna; Kulczykowska, Ewa

2017-01-01

Social relationships are crucially dependent on individual ability to learn and remember ecologically relevant cues. However, the way animals recognize cues before engaging in any social interaction and how their response is regulated by brain neuromodulators remains unclear. We examined the putative involvement of arginine vasotocin (AVT) and isotocin (IT), acting at different brain regions, during fish decision-making in the context of cooperation, by trying to identify how fish distinguish and recognize the value of other social partners or species. We hypothesized that the behavioural responses of cleaner fish clients to different social contexts would be underlain by changes in brain AVT and IT levels. We have found that changes in AVT at the level of forebrain and optic tectum are linked with a response to allopatric cleaners (novel or unfamiliar stimuli) while those at cerebellum are associated with the willingness to be cleaned (in response to sympatric cleaners). On the other hand, higher brain IT levels that were solely found in the diencephalon, also in response to allopatric cleaners. Our results are the first to implicate these nonapeptides, AVT in particular, in the assessment of social cues which enable fish to engage in mutualistic activities. PMID:28683143

Recreational fishing in surface mine lakes - a case study in St. Clair County, Illinois

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mannz, R.H.

1985-12-09

Recent mining legislation mandates the reclamation of surface-mined areas to the pre-mining contour, eliminating the potential of many new lakes. However, many pre-law mine lakes have considerable recreational value benefiting the surrounding regions. During 1983, 5296 anglers participated in Peabody Coal Company's Coal Company's recreational fishing program in St. Clair County, Illinois. A random sample of participants were mailed a questionnaire designed to identify user/area characteristics economic implications, and sport fishing resources of the program lakes. Sample data indicated 62,760 angling days spent on 600 acres of program waters during 1983. The single most sought after fish was the largemore » mouth bass. Expenditures by 1983 program users were estimated at $753,120 or $1255 per acre of surface water. Opportunity cost calculations indicated that recreational fishing was an equal or better trade-off to the regional economy when compared to income that could have been produced from rowcrop agriculture. Reclamation techniques designed for fish and wildlife purposes and leaving such areas should be encouraged. Returning surface-mined areas to the pre-mining contour and use is not necessarily the most cost effective or desirable method of reclamation. 14 references, 4 tables.« less

Fish assemblages, connectivity, and habitat rehabilitation in a diked Great Lakes coastal wetland complex

USGS Publications Warehouse

Kowalski, Kurt P.; Wiley, Michael J.; Wilcox, Douglas A.

2014-01-01

Fish and plant assemblages in the highly modified Crane Creek coastal wetland complex of Lake Erie were sampled to characterize their spatial and seasonal patterns and to examine the implications of the hydrologic connection of diked wetland units to Lake Erie. Fyke netting captured 52 species and an abundance of fish in the Lake Erie–connected wetlands, but fewer than half of those species and much lower numbers and total masses of fish were captured in diked wetland units. Although all wetland units were immediately adjacent to Lake Erie, there were also pronounced differences in water quality and wetland vegetation between the hydrologically isolated and lake-connected wetlands. Large seasonal variations in fish assemblage composition and biomass were observed in connected wetland units but not in disconnected units. Reestablishment of hydrologic connectivity in diked wetland units would allow coastal Lake Erie fish to use these vegetated habitats seasonally, although connectivity does appear to pose some risks, such as the expansion of invasive plants and localized reductions in water quality. Periodic isolation and drawdown of the diked units could still be used to mimic intermediate levels of disturbance and manage invasive wetland vegetation.

Large but uneven reduction in fish size across species in relation to changing sea temperatures.

PubMed

van Rijn, Itai; Buba, Yehezkel; DeLong, John; Kiflawi, Moshe; Belmaker, Jonathan

2017-09-01

Ectotherms often attain smaller body sizes when they develop at higher temperatures. This phenomenon, known as the temperature-size rule, has important consequences for global fisheries, whereby ocean warming is predicted to result in smaller fish and reduced biomass. However, the generality of this phenomenon and the mechanisms that drive it in natural populations remain unresolved. In this study, we document the maximal size of 74 fish species along a steep temperature gradient in the Mediterranean Sea and find strong support for the temperature-size rule. Importantly, we additionally find that size reduction in active fish species is dramatically larger than for more sedentary species. As the temperature dependence of oxygen consumption depends on activity levels, these findings are consistent with the hypothesis that oxygen is a limiting factor shaping the temperature-size rule in fishes. These results suggest that ocean warming will result in a sharp, but uneven, reduction in fish size that will cause major shifts in size-dependent interactions. Moreover, warming will have major implications for fisheries as the main species targeted for harvesting will show the most substantial declines in biomass. © 2017 John Wiley & Sons Ltd.

An emerging role for gasotransmitters in the control of breathing and ionic regulation in fish.

PubMed

Perry, Steve; Kumai, Y; Porteus, C S; Tzaneva, V; Kwong, R W M

2016-02-01

Three gases comprising nitric oxide, carbon monoxide and hydrogen sulphide, collectively are termed gasotransmitters. The gasotransmitters control several physiological functions in fish by acting as intracellular signaling molecules. Hydrogen sulphide, first implicated in vasomotor control in fish, plays a critical role in oxygen chemoreception owing to its production and downstream effects within the oxygen chemosensory cells, the neuroepithelial cells. Indeed, there is emerging evidence that hydrogen sulphide may contribute to oxygen sensing in both fish and mammals by promoting membrane depolarization of the chemosensory cells. Unlike hydrogen sulphide which stimulates breathing in zebrafish, carbon monoxide inhibits ventilation in goldfish and zebrafish whereas nitric oxide stimulates breathing in zebrafish larvae while inhibiting breathing in adults. Gasotransmitters also modulate ionic uptake in zebrafish. Though nothing is known about the role of CO, reduced activities of branchial Na(+)/K(+)-ATPase and H(+)-ATPase activities in the presence of NO donors suggest an inhibitory role of NO in fish osmoregulation. Hydrogen sulphide inhibits Na(+) uptake in zebrafish larvae and contributes to lowering Na(+) uptake capacity in fish acclimated to Na(+)-enriched water whereas it stimulates Ca(2+) uptake in larvae exposed to Ca(2+)-poor water.

High prevalence of vaterite in sagittal otoliths causes hearing impairment in farmed fish

PubMed Central

Reimer, T.; Dempster, T.; Warren-Myers, F.; Jensen, A. J.; Swearer, S. E.

2016-01-01

The rapid growth of aquaculture raises questions about the welfare status of mass-produced species. Sagittal otoliths are primary hearing structures in the inner ear of all teleost (bony) fishes and are normally composed of aragonite, though abnormal vaterite replacement is sometimes seen in the wild. We provide the first widespread evaluation of the prevalence of vaterite in otoliths, showing that farmed fish have levels of vaterite replacement over 10 times higher than wild fish, regardless of species. We confirm this observation with extensive sampling of wild and farmed Atlantic salmon in Norway, the world’s largest producer, and verify that vateritic otoliths are common in farmed salmon worldwide. Using a mechanistic model of otolith oscillation in response to sound, we demonstrate that average levels of vaterite replacement result in a 28–50% loss of otolith functionality across most of a salmonid’s known hearing range and throughout its life cycle. The underlying cause(s) of vaterite formation remain unknown, but the prevalence of hearing impairment in farmed fish has important implications for animal welfare, the survival of escapees and their effects on wild populations, and the efficacy of restocking programs based on captive-bred fish. PMID:27121086

Mapping of single-copy genes by TSA-FISH in the codling moth, Cydia pomonella.

PubMed

Carabajal Paladino, Leonela Z; Nguyen, Petr; Síchová, Jindra; Marec, František

2014-01-01

We work on the development of transgenic sexing strains in the codling moth, Cydia pomonella (Tortricidae), which would enable to produce male-only progeny for the population control of this pest using sterile insect technique (SIT). To facilitate this research, we have developed a number of cytogenetic and molecular tools, including a physical map of the codling moth Z chromosome using BAC-FISH (fluorescence in situ hybridization with bacterial artificial chromosome probes). However, chromosomal localization of unique, single-copy sequences such as a transgene cassette by conventional FISH remains challenging. In this study, we adapted a FISH protocol with tyramide signal amplification (TSA-FISH) for detection of single-copy genes in Lepidoptera. We tested the protocol with probes prepared from partial sequences of Z-linked genes in the codling moth. Using a modified TSA-FISH protocol we successfully mapped a partial sequence of the Acetylcholinesterase 1 (Ace-1) gene to the Z chromosome and confirmed thus its Z-linkage. A subsequent combination of BAC-FISH with BAC probes containing anticipated neighbouring Z-linked genes and TSA-FISH with the Ace-1 probe allowed the integration of Ace-1 in the physical map of the codling moth Z chromosome. We also developed a two-colour TSA-FISH protocol which enabled us simultaneous localization of two Z-linked genes, Ace-1 and Notch, to the expected regions of the Z chromosome. We showed that TSA-FISH represents a reliable technique for physical mapping of genes on chromosomes of moths and butterflies. Our results suggest that this technique can be combined with BAC-FISH and in the future used for physical localization of transgene cassettes on chromosomes of transgenic lines in the codling moth or other lepidopteran species. Furthermore, the developed protocol for two-colour TSA-FISH might become a powerful tool for synteny mapping in non-model organisms.

Mapping of single-copy genes by TSA-FISH in the codling moth, Cydia pomonella

PubMed Central

2014-01-01

Background We work on the development of transgenic sexing strains in the codling moth, Cydia pomonella (Tortricidae), which would enable to produce male-only progeny for the population control of this pest using sterile insect technique (SIT). To facilitate this research, we have developed a number of cytogenetic and molecular tools, including a physical map of the codling moth Z chromosome using BAC-FISH (fluorescence in situ hybridization with bacterial artificial chromosome probes). However, chromosomal localization of unique, single-copy sequences such as a transgene cassette by conventional FISH remains challenging. In this study, we adapted a FISH protocol with tyramide signal amplification (TSA-FISH) for detection of single-copy genes in Lepidoptera. We tested the protocol with probes prepared from partial sequences of Z-linked genes in the codling moth. Results Using a modified TSA-FISH protocol we successfully mapped a partial sequence of the Acetylcholinesterase 1 (Ace-1) gene to the Z chromosome and confirmed thus its Z-linkage. A subsequent combination of BAC-FISH with BAC probes containing anticipated neighbouring Z-linked genes and TSA-FISH with the Ace-1 probe allowed the integration of Ace-1 in the physical map of the codling moth Z chromosome. We also developed a two-colour TSA-FISH protocol which enabled us simultaneous localization of two Z-linked genes, Ace-1 and Notch, to the expected regions of the Z chromosome. Conclusions We showed that TSA-FISH represents a reliable technique for physical mapping of genes on chromosomes of moths and butterflies. Our results suggest that this technique can be combined with BAC-FISH and in the future used for physical localization of transgene cassettes on chromosomes of transgenic lines in the codling moth or other lepidopteran species. Furthermore, the developed protocol for two-colour TSA-FISH might become a powerful tool for synteny mapping in non-model organisms. PMID:25471491

Seahorse Brood Pouch Transcriptome Reveals Common Genes Associated with Vertebrate Pregnancy.

PubMed

Whittington, Camilla M; Griffith, Oliver W; Qi, Weihong; Thompson, Michael B; Wilson, Anthony B

2015-12-01

Viviparity (live birth) has evolved more than 150 times in vertebrates, and represents an excellent model system for studying the evolution of complex traits. There are at least 23 independent origins of viviparity in fishes, with syngnathid fishes (seahorses and pipefish) unique in exhibiting male pregnancy. Male seahorses and pipefish have evolved specialized brooding pouches that provide protection, gas exchange, osmoregulation, and limited nutrient provisioning to developing embryos. Pouch structures differ widely across the Syngnathidae, offering an ideal opportunity to study the evolution of reproductive complexity. However, the physiological and genetic changes facilitating male pregnancy are largely unknown. We used transcriptome profiling to examine pouch gene expression at successive gestational stages in a syngnathid with the most complex brood pouch morphology, the seahorse Hippocampus abdominalis. Using a unique time-calibrated RNA-seq data set including brood pouch at key stages of embryonic development, we identified transcriptional changes associated with brood pouch remodeling, nutrient and waste transport, gas exchange, osmoregulation, and immunological protection of developing embryos at conception, development and parturition. Key seahorse transcripts share homology with genes of reproductive function in pregnant mammals, reptiles, and other live-bearing fish, suggesting a common toolkit of genes regulating pregnancy in divergent evolutionary lineages. © The Author 2015. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Response of Coastal Fishes to the Gulf of Mexico Oil Disaster

PubMed Central

Fodrie, F. Joel; Heck, Kenneth L.

2011-01-01

The ecosystem-level impacts of the Deepwater Horizon disaster have been largely unpredictable due to the unique setting and magnitude of this spill. We used a five-year (2006–2010) data set within the oil-affected region to explore acute consequences for early-stage survival of fish species inhabiting seagrass nursery habitat. Although many of these species spawned during spring-summer, and produced larvae vulnerable to oil-polluted water, overall and species-by-species catch rates were high in 2010 after the spill (1,989±220 fishes km-towed−1 [μ ± 1SE]) relative to the previous four years (1,080±43 fishes km-towed−1). Also, several exploited species were characterized by notably higher juvenile catch rates during 2010 following large-scale fisheries closures in the northern Gulf, although overall statistical results for the effects of fishery closures on assemblage-wide CPUE data were ambiguous. We conclude that immediate, catastrophic losses of 2010 cohorts were largely avoided, and that no shifts in species composition occurred following the spill. The potential long-term impacts facing fishes as a result of chronic exposure and delayed, indirect effects now require attention. PMID:21754992

Polychlorinated biphenyl congener patterns in fish near the Hanford Site (Washington State, USA).

PubMed

Rodenburg, Lisa A; Delistraty, Damon; Meng, Qingyu

2015-03-03

It is well-known that absorption, distribution, metabolism, and excretion (ADME) processes in fish can alter polychlorinated biphenyl (PCB) congener patterns in fish, but these patterns have never been investigated using an advanced source-apportionment tool. In this work, PCB congener patterns in freshwater fish were examined with positive matrix factorization (PMF). PCB congeners were quantified via EPA Method 1668 in fillet and carcass of six species in four study areas in the Columbia River near the Hanford Site. Six factors were resolved with PMF2 software. Depletion and enhancement of PCB congeners in factors, relative to Aroclor 1254, suggested biotransformation (via cytochrome P450) and bioaccumulation in fish, respectively. Notable differences were observed among species and across study locations. For example, sturgeon and whitefish exhibited congener patterns consistent with Aroclor weathering, suggesting potential PCB metabolism in these species. In terms of location, average concentration of total PCBs for all species combined was significantly higher (P < 0.05) at Hanford 100 and 300 areas, relative to upriver and downriver study sites. Furthermore, a distinct PCB signature in sturgeon and whitefish, collected at Hanford study areas, suggests that Hanford is a unique PCB source.

Fish oil: what the prescriber needs to know

PubMed Central

Cleland, Leslie G; James, Michael J; Proudman, Susanna M

2006-01-01

There is a general belief among doctors, in part grounded in experience, that patients with arthritis need nonsteroidal anti-inflammatory drugs (NSAIDs). Implicit in this view is that these patients require the symptomatic relief provided by inhibiting synthesis of nociceptive prostaglandin E2, a downstream product of the enzyme cyclo-oxygenase (COX), which is inhibited by NSAIDs. However, the concept of 'safe' NSAIDs has collapsed following a multiplicity of observations establishing increased risk for cardiovascular events associated with NSAID use, especially but not uniquely with the new COX-2-selective NSAIDs. This mandates greater parsimony in the use of these agents. Fish oils contain a natural inhibitor of COX, reduce reliance on NSAIDs, and reduce cardiovascular risk through multiple mechanisms. Fish oil thus warrants consideration as a component of therapy for arthritis, especially rheumatoid arthritis, in which its symptomatic benefits are well established. A major barrier to the therapeutic use of fish oil in inflammatory diseases is ignorance of its mechanism, range of beneficial effects, safety profile, availability of suitable products, effective dose, latency of effects and instructions for administration. This review provides an evidence-based resource for doctors and patients who may choose to prescribe or take fish oil. PMID:16542466

Ranking the contributions of commercial fish and shellfish varieties to mercury exposure in the United States: implications for risk communication.

PubMed

Groth, Edward

2010-04-01

Fish and shellfish have important nutritional benefits, and US per capita seafood consumption has increased substantially since 2002. Recent research has reinforced concerns about adverse effects of methylmercury exposure, suggesting that methylmercury doses associated with typical US rates of fish consumption may pose measurable risks, with no threshold. These converging trends create a need to improve risk communication about fish consumption and mercury. The analysis performed here identifies the relative importance of different fish and shellfish as sources of mercury in the US seafood supply and proposes improved consumer advice, so that the public can benefit from fish consumption while minimizing mercury exposure. I have quantified contributions to total mercury in the US seafood supply by 51 different varieties of fish and shellfish, then ranked and sorted the 51 varieties in terms of relative impact. Except for swordfish, most fish with the highest mercury levels are relatively minor contributors to total inputs. Tuna (canned light, canned albacore and fresh/frozen varieties) accounts for 37.4 percent of total mercury inputs, while two-thirds of the seafood supply and nine of the 11 most heavily consumed fish and shellfish are low or very low in mercury. Substantial improvement in risk communication about mercury in fish and seafood is needed; in particular, several population subsets need better guidance to base their seafood choices more explicitly on mercury content. I have sorted the 51 seafood varieties into six categories based on mercury levels, as a framework for improving risk communication in this regard. (c) 2009 Elsevier Inc. All rights reserved.

Fish Ecology and Evolution in the World's Oxygen Minimum Zones and Implications of Ocean Deoxygenation.

PubMed

Gallo, N D; Levin, L A

Oxygen minimum zones (OMZs) and oxygen limited zones (OLZs) are important oceanographic features in the Pacific, Atlantic, and Indian Ocean, and are characterized by hypoxic conditions that are physiologically challenging for demersal fish. Thickness, depth of the upper boundary, minimum oxygen levels, local temperatures, and diurnal, seasonal, and interannual oxycline variability differ regionally, with the thickest and shallowest OMZs occurring in the subtropics and tropics. Although most fish are not hypoxia-tolerant, at least 77 demersal fish species from 16 orders have evolved physiological, behavioural, and morphological adaptations that allow them to live under the severely hypoxic, hypercapnic, and at times sulphidic conditions found in OMZs. Tolerance to OMZ conditions has evolved multiple times in multiple groups with no single fish family or genus exploiting all OMZs globally. Severely hypoxic conditions in OMZs lead to decreased demersal fish diversity, but fish density trends are variable and dependent on region-specific thresholds. Some OMZ-adapted fish species are more hypoxia-tolerant than most megafaunal invertebrates and are present even when most invertebrates are excluded. Expansions and contractions of OMZs in the past have affected fish evolution and diversity. Current patterns of ocean warming are leading to ocean deoxygenation, causing the expansion and shoaling of OMZs, which is expected to decrease demersal fish diversity and alter trophic pathways on affected margins. Habitat compression is expected for hypoxia-intolerant species, causing increased susceptibility to overfishing for fisheries species. Demersal fisheries are likely to be negatively impacted overall by the expansion of OMZs in a warming world. © 2016 Elsevier Ltd. All rights reserved.

Dynamic hypoxic zones in Lake Erie compress fish habitat, altering vulnerability to fishing gears

USGS Publications Warehouse

Kraus, Richard T.; Knight, Carey T.; Farmer, Troy M.; Gorman, Ann Marie; Collingsworth, Paris D.; Warren, Glenn J.; Kocovsky, Patrick M.; Conroy, Joseph D.

2015-01-01

Seasonal degradation of aquatic habitats from hypoxia occurs in numerous freshwater and coastal marine systems and can result in direct mortality or displacement of fish. Yet, fishery landings from these systems are frequently unresponsive to changes in the severity and extent of hypoxia, and population-scale effects have been difficult to measure except in extreme hypoxic conditions with hypoxia-sensitive species. We investigated fine-scale temporal and spatial variability in dissolved oxygen in Lake Erie as it related to fish distribution and catch efficiencies of both active (bottom trawls) and passive (trap nets) fishing gears. Temperature and dissolved oxygen loggers placed near the edge of the hypolimnion exhibited much higher than expected variability. Hypoxic episodes of variable durations were frequently punctuated by periods of normoxia, consistent with high-frequency internal waves. High-resolution interpolations of water quality and hydroacoustic surveys suggest that fish habitat is compressed during hypoxic episodes, resulting in higher fish densities near the edges of hypoxia. At fixed locations with passive commercial fishing gear, catches with the highest values occurred when bottom waters were hypoxic for intermediate proportions of time. Proximity to hypoxia explained significant variation in bottom trawl catches, with higher catch rates near the edge of hypoxia. These results emphasize how hypoxia may elevate catch rates in various types of fishing gears, leading to a lack of association between indices of hypoxia and fishery landings. Increased catch rates of fish at the edges of hypoxia have important implications for stock assessment models that assume catchability is spatially homogeneous.

Is Your Fish Dead? Create Your Library Brand

ERIC Educational Resources Information Center

Fullner, Sheryl Kindle

2007-01-01

Establishing a library brand requires positive effects on publics. Five publics identify each library: students, teachers, administration, parents, and community. It takes effort to target each of those five publics with a consistent message about what a library offers that makes it unique. Librarians, scrambling to accomplish the necessities of…

Analysis of fish movements between Great Lakes coastal wetlands and near shore habitat via otolith microchemistry

EPA Science Inventory

Great Lakes coastal wetlands are unique habitats with physical connections with near shore environments. This facilitates the exchange of energy between habitats in a principle known as habitat coupling. Coupling can be facilitated by movements of consumers; however, wetland us...

Fundulus as the Premier Teleost Model in Environmental Biology: Opportunities for New Insights Using Genomics

EPA Science Inventory

A strong foundation of basic and applied research documents that the estuarine fish Fundulus heteroclitus and related species are unique laboratory and field models for understanding how individuals and populations interact with their environment. In this paper we summarize an ex...

Visual observation of fishes and aquatic habitat [Chapter 17

Treesearch

Russell F. Thurow; C. Andrew Dolloff; J. Ellen Marsden

2012-01-01

Whether accomplished above the water surface or performed underwater by snorkel, scuba, or hookah divers or remotely operated vehicles (ROVs); direct observation techniques are among the most effective means for obtaining accurate and often unique information on aquatic organisms in their natural surroundings. Many types of studies incorporate direct observation...

Novel Acoustic Techniques for Assessing Fish Schooling in the Context of an Operational Ocean Observatory

DTIC Science & Technology

2008-09-30

Atlantic Bight (MAB). The surveys will be positioned adaptively using real-time data collected with the international constellation of ocean color...and onshore waters. A unique acoustic scattering source was identified during the experiment as dense, monotypic aggregations of a pelagic gastropod

Rheological and Functional Properties of Catfish Skin Protein Hydrolysates

USDA-ARS?s Scientific Manuscript database

Catfish skin is an abundant and underutilized resource that can be used as a unique protein source to make fish skin hydrolysates. The objectives of this study were to: isolating soluble and insoluble proteins from hydrolyzed catfish skin and study the chemical and functional properties of the prote...

Gone Fishing

ERIC Educational Resources Information Center

Springer Pence, Mary E.

2004-01-01

In this article, the author describes how the orientation staff at the University of Louisville used a unique blend of play and student learning to engage more students more deeply in their orientation experience as they learn the basics for success in college. This approach to orientation is based from Stephen Lundin, Harry Paul, and John…

Wood and fish residuals composting in Alaska

Treesearch

David Nicholls; Thomas Richard; Jesse A. Micales

2002-01-01

The unique climates and industrial mix in southeast and south central Alaska are challenges being met by the region's organics recyclers. OMPOSTING wood residuals in Alaska has become increasingly important in recent years as wood processors and other industrial waste managers search for environmentally sound and profitable outlets. Traditionally, Alaska?s...

Characteristics of nonylphenol and bisphenol A accumulation by fish and implications for ecological and human health.

PubMed

Lee, Ching-Chang; Jiang, Ling-Ying; Kuo, Yi-Ling; Chen, Chung-Yu; Hsieh, Chia-Yi; Hung, Chung-Feng; Tien, Chien-Jung

2015-01-01

Fish populations constitute an important part of aquatic ecosystems. Thus, their accumulation of nonylphenol (NP) and bisphenol A (BPA) may pose risks to ecosystems and human health. This study analyzed the concentrations of NP and BPA in four types of fishes (i.e., wild/farmed freshwater fishes and wild/farmed marine fishes). Wild freshwater fishes contained higher concentrations of NP and BPA than the other three types of fishes. The concentrations of NP in the wild freshwater fishes ranged from 1.01 to 277 μg/kg ww, with bioconcentration factors (BCFs) and biota-sediment accumulation factors (BSAFs) ranging from 74.0 to 2.60 × 10(4)L/kg and from 0.003 to 18.3, respectively. The wild freshwater fishes contained relatively low amounts of BPA, varying from ND to 25.2 μg/kg ww, with the BCFs and BSAFs ranging from 1.00 to 274L/kg and from 0.003 to 3.40, respectively. Five fish species particularly showed high BCFs and BSAFs, indicating that they could be an important source of NP for higher trophic levels, most likely resulting in ecological risks. The demersal fishes showed a greater ability to accumulate NP than the pelagic ones. The fact that the 95th percentile values of the risk quotient (RQ) for NP and BPA were higher than the acceptable threshold indicated that these two compounds would have adverse effects on aquatic organisms in Taiwanese rivers. The consumption of wild marine fishes had the highest 95th percentile values of hazard quotient (HQ) for NP and BPA among the four types of fishes, particularly for the population aged 0-3 years. However, the 95th percentile values of HQ for NP and BPA were all less than 1, suggesting that exposure to NP and BPA through fish consumption posed no remarkable risk to human health in Taiwan. Copyright © 2014 Elsevier B.V. All rights reserved.

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

PubMed

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.

Effects of dams in river networks on fish assemblages in non-impoundment sections of rivers in Michigan and Wisconsin, USA

USGS Publications Warehouse

Stewart, Jana S.; Lizhu Wang,; Infante, Dana M.; Lyons, John D.; Arthur Cooper,

2011-01-01

Regional assessment of cumulative impacts of dams on riverine fish assemblages provides resource managers essential information for dam operation, potential dam removal, river health assessment and overall ecosystem management. Such an assessment is challenging because characteristics of fish assemblages are not only affected by dams, but also influenced by natural variation and human-induced modification (in addition to dams) in thermal and flow regimes, physicochemical habitats and biological assemblages. This study evaluated the impacts of dams on river fish assemblages in the non-impoundment sections of rivers in the states of Michigan and Wisconsin using multiple fish assemblage indicators and multiple approaches to distinguish the influences of dams from those of other natural and human-induced factors. We found that environmental factors that influence fish assemblages in addition to dams should be incorporated when evaluating regional effects of dams on fish assemblages. Without considering such co-influential factors, the evaluation is inadequate and potentially misleading. The role of dams alone in determining fish assemblages at a regional spatial scale is relatively small (explained less than 20% of variance) compared with the other environmental factors, such as river size, flow and thermal regimes and land uses jointly. However, our results do demonstrate that downstream and upstream dams can substantially modify fish assemblages in the non-impoundment sections of rivers. After excluding river size and land-use influences, our results clearly demonstrate that dams have significant impacts on fish biotic-integrity and habitat-and-social-preference indicators. The influences of the upstream dams, downstream dams, distance to dams, and dam density differ among the fish indicators, which have different implications for maintaining river biotic integrity, protecting biodiversity and managing fisheries.

The Farther the Better: Effects of Multiple Environmental Variables on Reef Fish Assemblages along a Distance Gradient from River Influences.

PubMed

Neves, Leonardo M; Teixeira-Neves, Tatiana P; Pereira-Filho, Guilherme H; Araújo, Francisco G

2016-01-01

The conservation and management of site-attached assemblages of coastal reefs are particularly challenging because of the tremendous environmental variation that exists at small spatial scales. In this sense, understanding the primary sources of variation in spatial patterns of the biota is fundamental for designing effective conservation policies. We investigated spatial variation in fish assemblages around the windward and leeward sides of coastal islands situated across a gradient of riverine influence (13 km in length). Specifically, relationships between rocky reef fish assemblages and benthic, topographic and physical predictors were assessed. We hypothesized that river induced disturbances may overcome local habitat features in modeling spatial patterns of fish distribution. Fish assemblages varied primarily due to the strong directional gradient of riverine influence (22.6% of the estimated components of variation), followed by topographic complexity (15%), wave exposure (9.9%), and benthic cover (8%). The trophic structure of fish assemblages changed from having a high abundance of invertebrate feeders in macroalgae-dominated reefs close to river mouths to a high proportion of herbivores, planktivores and invertebrate feeder species in reefs with large boulders covered by epilithic algal matrices, as the distance from rivers increased. This gradient led to an increase of 4.5-fold in fish richness and fish trophic group diversity, 11-fold in fish biomass and 10-fold in fish abundance. Our results have implications for the conservation and monitoring of assemblages patchily distributed at small spatial scales. The major role of distance from river influences on fish assemblages rather than benthic cover and topographic complexity suggest that managing land-based activities should be a conservation priority toward reef restoration.

Fish Ecology and Evolution in the World's Oxygen Minimum Zones and Implications of a Warming Ocean

NASA Astrophysics Data System (ADS)

Gallo, N.; Navarro, E. C.; Yazzie, A. T.; Barry, J. P.; Levin, L. A.

2016-02-01

Predicting how demersal fish communities will respond as hypoxic areas expand with climate change requires an understanding of how existing oxygen gradients influence the abundance, diversity, and trophic ecology of demersal fish communities. A literature review of studies from continental margins with oxygen minimum zones in the Pacific, Atlantic, and Indian Ocean, is combined with new data from research cruises to the Gulf of California and the US West Coast, to examine how hypoxic areas influence the structure and function of demersal fish communities. Oxygen minimum zones (OMZs) are deep-sea environments where organisms experience chronic hypoxic and suboxic conditions and have persisted over much longer timescales than coastal eutrophication-induced hypoxic zones, allowing for the evolution of adaptations to low oxygen conditions. While coastal studies have found that fish are one of the most hypoxia-intolerant groups, representative demersal fish species in the orders Cottiformes, Scorpaeniformes, Pleuronectiformes, Gobiiformes, Perciformes, Lophiiformes, Carcharhiniformes, Ophidiiformes, Myxiniformes, and Gadiformes have evolved to exploit physiologically extreme OMZ environments and are important components of the benthic community. In OMZs, certain fish species are some of the most hypoxia-tolerant members of the megafauna community, present even under extremely low oxygen conditions (< 5 µmol/kg) where most invertebrates are absent, though these communities are typically characterized by single-species dominance. To explore differences in the trophic ecology of these "hypoxia-tolerant" fish communities, stable isotope and gut content analysis are used to compare the Southern California Bight OMZ core fish community to the hypoxia-intolerant upper slope fish community. Results show that fish living in the OMZ core have significantly enriched δ13C and δ15N signatures and feed on different prey items.

Understanding spearfishing in a coral reef fishery: Fishers' opportunities, constraints, and decision-making.

PubMed

Pavlowich, Tyler; Kapuscinski, Anne R

2017-01-01

Social and ecological systems come together during the act of fishing. However, we often lack a deep understanding of the fishing process, despite its importance for understanding and managing fisheries. A quantitative, mechanistic understanding of the opportunities fishers encounter, the constraints they face, and how they make decisions within the context of opportunities and constraints will enhance the design of fisheries management strategies to meet linked ecological and social objectives and will improve scientific capacity to predict impacts of different strategies. We examined the case of spearfishing in a Caribbean coral reef fishery. We mounted cameras on fishers' spearguns to observe the fish they encountered, what limited their ability to catch fish, and how they made decisions about which fish to target. We observed spearfishers who dove with and without the assistance of compressed air, and compared the fishing process of each method using content analysis of videos and decision models of fishers' targeting selections. Compressor divers encountered more fish, took less time to catch each fish, and had a higher rate of successful pursuits. We also analyzed differences among taxa in this multispecies fishery, because some taxa are known to be ecologically or economically more valuable than others. Parrotfish are ecologically indispensable for healthy coral reefs, and they were encountered and captured more frequently than any other taxon. Fishers made decisions about which fish to target based on a fish's market value, proximity to the fisher, and taxon. The information uncovered on fishers' opportunities, constraints, and decision making has implications for managing this fishery and others. Moreover, it demonstrates the value of pursuing an improved understanding of the fishing process from the perspective of the fishers.

The Farther the Better: Effects of Multiple Environmental Variables on Reef Fish Assemblages along a Distance Gradient from River Influences

PubMed Central

Neves, Leonardo M.; Teixeira-Neves, Tatiana P.; Pereira-Filho, Guilherme H.; Araújo, Francisco G.

2016-01-01

The conservation and management of site-attached assemblages of coastal reefs are particularly challenging because of the tremendous environmental variation that exists at small spatial scales. In this sense, understanding the primary sources of variation in spatial patterns of the biota is fundamental for designing effective conservation policies. We investigated spatial variation in fish assemblages around the windward and leeward sides of coastal islands situated across a gradient of riverine influence (13 km in length). Specifically, relationships between rocky reef fish assemblages and benthic, topographic and physical predictors were assessed. We hypothesized that river induced disturbances may overcome local habitat features in modeling spatial patterns of fish distribution. Fish assemblages varied primarily due to the strong directional gradient of riverine influence (22.6% of the estimated components of variation), followed by topographic complexity (15%), wave exposure (9.9%), and benthic cover (8%). The trophic structure of fish assemblages changed from having a high abundance of invertebrate feeders in macroalgae-dominated reefs close to river mouths to a high proportion of herbivores, planktivores and invertebrate feeder species in reefs with large boulders covered by epilithic algal matrices, as the distance from rivers increased. This gradient led to an increase of 4.5-fold in fish richness and fish trophic group diversity, 11-fold in fish biomass and 10-fold in fish abundance. Our results have implications for the conservation and monitoring of assemblages patchily distributed at small spatial scales. The major role of distance from river influences on fish assemblages rather than benthic cover and topographic complexity suggest that managing land-based activities should be a conservation priority toward reef restoration. PMID:27907017

Effects of dams in river networks on fish assemblages in non-impoundment sections of rivers in Michigan and Wisconsin, USA

USGS Publications Warehouse

Wang, L.; Infante, D.; Lyons, J.; Stewart, J.; Cooper, A.

2011-01-01

Regional assessment of cumulative impacts of dams on riverine fish assemblages provides resource managers essential information for dam operation, potential dam removal, river health assessment and overall ecosystem management. Such an assessment is challenging because characteristics of fish assemblages are not only affected by dams, but also influenced by natural variation and human-induced modification (in addition to dams) in thermal and flow regimes, physicochemical habitats and biological assemblages. This study evaluated the impacts of dams on river fish assemblages in the non-impoundment sections of rivers in the states of Michigan and Wisconsin using multiple fish assemblage indicators and multiple approaches to distinguish the influences of dams from those of other natural and human-induced factors. We found that environmental factors that influence fish assemblages in addition to dams should be incorporated when evaluating regional effects of dams on fish assemblages. Without considering such co-influential factors, the evaluation is inadequate and potentially misleading. The role of dams alone in determining fish assemblages at a regional spatial scale is relatively small (explained less than 20% of variance) compared with the other environmental factors, such as river size, flow and thermal regimes and land uses jointly. However, our results do demonstrate that downstream and upstream dams can substantially modify fish assemblages in the non-impoundment sections of rivers. After excluding river size and land-use influences, our results clearly demonstrate that dams have significant impacts on fish biotic-integrity and habitat-and-social-preference indicators. The influences of the upstream dams, downstream dams, distance to dams, and dam density differ among the fish indicators, which have different implications for maintaining river biotic integrity, protecting biodiversity and managing fisheries. ?? 2010 John Wiley & Sons, Ltd.

Repeated evolution of amphibious behavior in fish and its implications for the colonization of novel environments.

PubMed

Ord, Terry J; Cooke, Georgina M

2016-08-01

We know little about on how frequently transitions into new habitats occur, especially the colonization of novel environments that are the most likely to instigate adaptive evolution. One of the most extreme ecological transitions has been the shift in habitat associated with the move from water to land by amphibious fish. We provide the first phylogenetic investigation of these transitions for living fish. Thirty-three families have species reported to be amphibious and these are likely independent evolutionary origins of fish emerging onto land. Phylogenetic reconstructions of closely related taxa within one of these families, the Blenniidae, inferred as many as seven convergences on a highly amphibious lifestyle. Taken together, there appear to be few constraints on fish emerging onto land given amphibious behavior has evolved repeatedly many times across ecologically diverse families. The colonization of novel habitats by other taxa resulting in less dramatic changes in environment should be equally, if not, more frequent in nature, providing an important prerequisite for subsequent adaptive differentiation. © 2016 The Author(s). Evolution © 2016 The Society for the Study of Evolution.

Proximate composition, energetic value, and relative abundance of prey fish from the inshore eastern Bering Sea: Implications for piscivorous predators

USGS Publications Warehouse

Ball, J.R.; Esler, Daniel N.; Schmutz, J.A.

2007-01-01

Changing ocean conditions and subsequent shifts in forage fish communities have been linked to numerical declines of some piscivorous marine birds and mammals in the North Pacific. However, limited information about fish communities is available for some regions, including nearshore waters of the eastern Bering Sea, where many piscivores reside. We determined proximate composition and energetic value of a suite of potential forage fish collected from an estuary on the Yukon-Kuskokwim Delta, Alaska, during 2002 and 2003. Across species, energy density ranged from 14.5 to 20.7 kJ g−1 dry mass and varied primarily as a function of lipid content. Total energy content was strongly influenced by body length and we provide species-specific predictive models of total energy based on this relationship; some models may be improved further by incorporating year and date effects. Based on observed energetic differences, we conclude that variation in fish size, quantity, and species composition of the prey community could have important consequences for piscivorous predators.

Size-related bioconcentration kinetics of hydrophobic chemicals in fish

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sijm, D.T.H.M.; Linde, A. van der

1994-12-31

Uptake and elimination of hydrophobic chemicals by fish can be regarded as passive diffusive transport processes. Diffusion coefficients, lipid/water partitioning, diffusion pathlenghts, concentration gradients and surface exchange areas are key parameters describing this bioconcentration distribution process. In the present study two of these parameters were studied: the influence of lipid/water partitioning was studied by using hydrophobic chemicals of different hydrophobicity, and the surface exchange area by using different sizes of fish. By using one species of fish it was assumed that all other parameters were kept constant. Seven age classes of fish were exposed to a series of hydrophobic, formore » five days, which was followed by a deputation phase lasting up to 6 months. Bioconcentration parameters, such as uptake and elimination rate constants, and bioconcentration factors were determined. Uptake of the hydrophobic compounds was compared to that of oxygen. Uptake and elimination rates were compared to weight and estimated (gill) exchange areas. The role of weight and its implications for extrapolations of bioconcentration parameters to other species and sizes will be discussed.« less

Invasive lionfish drive Atlantic coral reef fish declines.

PubMed

Green, Stephanie J; Akins, John L; Maljković, Aleksandra; Côté, Isabelle M

2012-01-01

Indo-Pacific lionfish (Pterois volitans and P. miles) have spread swiftly across the Western Atlantic, producing a marine predator invasion of unparalleled speed and magnitude. There is growing concern that lionfish will affect the structure and function of invaded marine ecosystems, however detrimental impacts on natural communities have yet to be measured. Here we document the response of native fish communities to predation by lionfish populations on nine coral reefs off New Providence Island, Bahamas. We assessed lionfish diet through stomach contents analysis, and quantified changes in fish biomass through visual surveys of lionfish and native fishes at the sites over time. Lionfish abundance increased rapidly between 2004 and 2010, by which time lionfish comprised nearly 40% of the total predator biomass in the system. The increase in lionfish abundance coincided with a 65% decline in the biomass of the lionfish's 42 Atlantic prey fishes in just two years. Without prompt action to control increasing lionfish populations, similar effects across the region may have long-term negative implications for the structure of Atlantic marine communities, as well as the societies and economies that depend on them.

Invasive Lionfish Drive Atlantic Coral Reef Fish Declines

PubMed Central

Green, Stephanie J.; Akins, John L.; Maljković, Aleksandra; Côté, Isabelle M.

2012-01-01

Indo-Pacific lionfish (Pterois volitans and P. miles) have spread swiftly across the Western Atlantic, producing a marine predator invasion of unparalleled speed and magnitude. There is growing concern that lionfish will affect the structure and function of invaded marine ecosystems, however detrimental impacts on natural communities have yet to be measured. Here we document the response of native fish communities to predation by lionfish populations on nine coral reefs off New Providence Island, Bahamas. We assessed lionfish diet through stomach contents analysis, and quantified changes in fish biomass through visual surveys of lionfish and native fishes at the sites over time. Lionfish abundance increased rapidly between 2004 and 2010, by which time lionfish comprised nearly 40% of the total predator biomass in the system. The increase in lionfish abundance coincided with a 65% decline in the biomass of the lionfish's 42 Atlantic prey fishes in just two years. Without prompt action to control increasing lionfish populations, similar effects across the region may have long-term negative implications for the structure of Atlantic marine communities, as well as the societies and economies that depend on them. PMID:22412895

Endogenous orienting in the archer fish.

PubMed

Saban, William; Sekely, Liora; Klein, Raymond M; Gabay, Shai

2017-07-18

The literature has long emphasized the neocortex's role in volitional processes. In this work, we examined endogenous orienting in an evolutionarily older species, the archer fish, which lacks neocortex-like cells. We used Posner's classic endogenous cuing task, in which a centrally presented, spatially informative cue is followed by a target. The fish responded to the target by shooting a stream of water at it. Interestingly, the fish demonstrated a human-like "volitional" facilitation effect: their reaction times to targets that appeared on the side indicated by the precue were faster than their reaction times to targets on the opposite side. The fish also exhibited inhibition of return, an aftermath of orienting that commonly emerges only in reflexive orienting tasks in human participants. We believe that this pattern demonstrates the acquisition of an arbitrary connection between spatial orienting and a nonspatial feature of a centrally presented stimulus in nonprimate species. In the literature on human attention, orienting in response to such contingencies has been strongly associated with volitional control. We discuss the implications of these results for the evolution of orienting, and for the study of volitional processes in all species, including humans.

Effect of fish oil on glutathione redox system in multiple sclerosis

PubMed Central

Sorto-Gomez, Tania E; Ortiz, Genaro G; Pacheco-Moises, Fermín P; Torres-Sanchez, Erandis D; Ramirez-Ramirez, Viridiana; Macias-Islas, Miguel A; de la Rosa, Alfredo Celis; Velázquez-Brizuela, Irma E

2016-01-01

Multiple sclerosis (MS) is a chronic, inflammatory and autoimmune disease of the central nervous system. Dysregulation of glutathione homeostasis and alterations in glutathione-dependent enzyme activities are implicated in the induction and progression of MS. Evidence suggests that Omega-3 polyunsaturated fatty acids (PUFAs) have anti-inflammatory, antioxidant and neuroprotective effects. The aim of the present work was to evaluate the effect of fish oil on the activity of glutathione reductase (GR), content of reduced and oxidized glutathione, and GSH/GSSG ratio in MS. 50 patients with relapsing-remitting MS were enrolled. The experimental group received orally 4 g/day of fish oil for 12 months. Fish oil supplementation resulted in a significant increase in n-3 fatty acids and a decrease n-6 fatty acids. No differences in glutathione reductase activity, content of reduced and oxidized glutathione, and GSH/GSSG ratio were found. Conclusion: Glutathione reductase activity was not significantly different between the groups; however, fish oil supplementation resulted in smaller increase in GR compared with control group, suggesting a possible effect on antioxidant defence mechanisms. PMID:27335704

High fluid shear strain causes injury in silver shark: Preliminary implications for Mekong hydropower turbine design

DOE Office of Scientific and Technical Information (OSTI.GOV)

Baumgartner, L. J.; Thorncraft, G.; Phonekhampheng, O.

Fluid shear arises when two bodies of water, travelling at different velocities, intersect. Fish entrained at the interface of these two water masses will experience shear stress; which can be harmful. The stress magnitude is dependent on waterbody mass and velocity; with the fish impact largely related to body size. Elevated shear stress occurs where rapidly flowing water passes near spillways, across screens, within turbine draft tubes or other passage routes. A flume was used to determine critical tolerances of silver shark (Balantiocheilos melanopterus) to different shear stress rates generated by a high velocity jet. Fish experienced higher levels ofmore » injury and mortality as shear stress was increased. Excessive shear forces had damaging impacts on fish. Mortality occurred at shear levels higher that 600/s. It is important that developers should attempt to model potential shear profiles expected during turbine passage in selected designs. These data will be critical to determine potential impacts on fish. If the likelihood of adverse impact is high, then alternative designs which have lower shear stress could be explored.« less

Fish egg injection as an alternative exposure route for early life stage toxicity studies: Description of two unique methods: Chapter 4

USGS Publications Warehouse

Walker, Mary K.; Zabel, Erik W.; Akerman, Gun; Balk, Lennart; Wright, Peggy J.; Tillitt, Donald E.

1996-01-01

In the environment, lipophilic contaminants such as halogenated aromatic hydrocarbons (HAHs, e.g., polychlorinated biphenyls, PCBs) and polycyclic aromatic hydrocarbons (PAHs, e.g., benzo[a]pyrene) readily bioaccumulate in fish, and the bioaccumulation of these lipophilic chemicals by adult fish may have significant consequences on the development and survival of their offspring. Halogenated and polycyclic aromatic hydrocarbons translocate from adult female body stores into eggs during oocyte maturation, and early life stages of fish are often more sensitive than adults to the toxicity of these chemicals. Thus, the presence of persistent, bioaccumulative contaminants in the environment may pose a risk to fish early life stage survival and ultimately reduce recruitment into the adult population.Typically, standard early life stage toxicity studies exposed embryos, larvae, and juveniles to graded concentrations of waterborne toxicants, and dose-response relationships are based on the concentrations of chemicals in the water. However, use of waterborne exposure to assess the toxicity of persistent, bioaccumulative contaminants, such as HAHs and PAHs, has two significant drawbacks. First, uptake of hydrophobic chemicals, such as HAHs and PAHs, into the developing embryo from water is not a significant route of exposure in the environment since concentrations of these chemicals freely dissolved in water are extremely low. Rather, maternal deposition into developing oocytes is the most significant source of these chemicals to the embryo. Second, the dose received by the target tissue, in this case the developing embryo, is the most accurate predictor of the toxic response, and since extrapolation from water concentrations of the chemical to egg concentrations is required, the exact dose received by the embryo can only be estimated, often with large uncertainty. Due to these drawbacks, it is important to develop an alternative exposure method that will directly expose the developing embryo without the need to chronically expose adult fish with subsequent natural deposition of hydrophobic chemicals into the oocytes. Fish egg injection provides this exposure route. Embryos are exposed directly after fertilization with known doses of contaminants, the dose is delivered prior to critical developmental events, and extrapolation of the dose received by the embryo is not needed.We have developed two unique fish egg injection methods as alternative routes of exposure for fish early life stage toxicity studies of lipophilic environmental contaminants. With either method, individual fish eggs are injected with a known dose of chemical. The first approach, a microinjection method, originally developed to assess the developmental toxicity of HAH congeners to early life stages of salmonids, utilizes micro-syringes, 30- gauge stainless steel injection needles, and micro- to nanoliter injection volume. The second approach, a nano-injection method, utilizes glass capillary micropipettes with 2 to 10 µm tips as injection needles, and nano- to picoliter injection volume, allowing injection of nearly any size of fish egg.Both of these egg injection methods allow an investigator to assess the toxicity of lipophilic environmental contaminants to early life stages of fish in a manner that realistically reflects environmental exposure and allows accurate quantitation of the dose to the developing embryo. These injection techniques, however, are not limited to use with only lipophilic chemicals. Since the developmental toxicity of many environmental contaminants ultimately depends on the dose received by the embryo, these egg injection methods could serve as a realistic exposure route in many fish early life stage toxicity studies.

Seasonal changes in community composition and trophic structure of fish populations of five salt marshes along the Essex coastline, United Kingdom

NASA Astrophysics Data System (ADS)

Green, Benjamin C.; Smith, David J.; Earley, Sarah E.; Hepburn, Leanne J.; Underwood, Graham J. C.

2009-11-01

European intertidal salt marshes are important nursery sites for juvenile fish and crustaceans. Due to the increasing threat of habitat loss, the seasonal changes of salt marsh fish communities need to be understood in order to appreciate the ecological and economic importance of the saltmarsh habitat. This study was the first in Great Britain to investigate the seasonal changes of salt marsh fish communities and the variation in community structure between closely located marsh habitats. Between February 2007 and March 2008, five marshes on three estuaries of the Essex coastline were sampled using flume nets to block off intertidal creeks at high tide. Fourteen fish species were caught. The community overall was dominated by three species that made up 91.6% of the total catch: the common goby Pomatoschistus microps (46.2% of the total catch), juvenile herring Clupea harengus (24.3%), and juvenile and larval sea bass Dicentrarchus labrax (21.2%). Cluster analysis demonstrated clear seasonal patterns, with some community structures unique to specific marshes or estuaries. The marsh fish community shifts from a highly diverse community during spring, to a community dominated by D. labrax and P. microps in autumn, and low diversity during winter months. Gravimetric stomach content analysis of fish community identified three main trophic guilds; macroinvertivores, planktivores and omnivores. The macroinvertivore feeding guild contained D. labrax and P. microps, the two most frequently occurring species. This investigation demonstrates the importance of British salt marshes as nursery habitats for commercial fish species.

Recovery of Coastal Fauna after the 2011 Tsunami in Japan as Determined by Bimonthly Underwater Visual Censuses Conducted over Five Years.

PubMed

Masuda, Reiji; Hatakeyama, Makoto; Yokoyama, Katsuhide; Tanaka, Masaru

2016-01-01

Massive tsunamis induce catastrophic disturbance in marine ecosystems, yet they can provide unique opportunities to observe the process of regeneration. Here, we report the recovery of fauna after the 2011 tsunami in northeast Japan based on underwater visual censuses performed every two months over five years. Both total fish abundance and species richness increased from the first to the second year after the tsunami followed by stabilization in the following years. Short-lived fish, such as the banded goby Pterogobius elapoides, were relatively abundant in the first two years, whereas long-lived species, such as the black rockfish Sebastes cheni, increased in the latter half of the survey period. Tropical fish species were recorded only in the second and third years after the tsunami. The body size of long-lived fish increased during the survey period resulting in a gradual increase of total fish biomass. The recovery of fish assemblages was slow at one site located in the inner bay, where the impact of the tsunami was the strongest. Apart from fish, blooms of the moon jellyfish Aurelia sp. occurred only in the first two years after the tsunami, whereas the abundances of sea cucumber Apostichopus japonicus and abalone Haliotis discus hannai increased after the second year. Although we lack quantitative data prior to the tsunami, we conclude that it takes approximately three years for coastal reef fish assemblages to recover from a heavy disturbance such as a tsunami and that the recovery is dependent on species-specific life span and habitat.

Epigenomics in marine fishes.

PubMed

Metzger, David C H; Schulte, Patricia M

2016-12-01

Epigenetic mechanisms are an underappreciated and often ignored component of an organism's response to environmental change and may underlie many types of phenotypic plasticity. Recent technological advances in methods for detecting epigenetic marks at a whole-genome scale have launched new opportunities for studying epigenomics in ecologically relevant non-model systems. The study of ecological epigenomics holds great promise to better understand the linkages between genotype, phenotype, and the environment and to explore mechanisms of phenotypic plasticity. The many attributes of marine fish species, including their high diversity, variable life histories, high fecundity, impressive plasticity, and economic value provide unique opportunities for studying epigenetic mechanisms in an environmental context. To provide a primer on epigenomic research for fish biologists, we start by describing fundamental aspects of epigenetics, focusing on the most widely studied and most well understood of the epigenetic marks: DNA methylation. We then describe the techniques that have been used to investigate DNA methylation in marine fishes to date and highlight some new techniques that hold great promise for future studies. Epigenomic research in marine fishes is in its early stages, so we first briefly discuss what has been learned about the establishment, maintenance, and function of DNA methylation in fishes from studies in zebrafish and then summarize the studies demonstrating the pervasive effects of the environment on the epigenomes of marine fishes. We conclude by highlighting the potential for ongoing research on the epigenomics of marine fishes to reveal critical aspects of the interaction between organisms and their environments. Copyright © 2016 Elsevier B.V. All rights reserved.

High-resolution FISH on super-stretched flow-sorted plant chromosomes.

PubMed

Valárik, M; Bartos, J; Kovárová, P; Kubaláková, M; de Jong, J H; Dolezel, J

2004-03-01

A novel high-resolution fluorescence in situ hybridisation (FISH) strategy, using super-stretched flow-sorted plant chromosomes as targets, is described. The technique that allows longitudinal extension of chromosomes of more than 100 times their original metaphase size is especially attractive for plant species with large chromosomes, whose pachytene chromosomes are generally too long and heterochromatin patterns too complex for FISH analysis. The protocol involves flow cytometric sorting of metaphase chromosomes, mild proteinase-K digestion of air-dried chromosomes on microscopic slides, followed by stretching with ethanol:acetic acid (3 : 1). Stretching ratios were assessed in a number of FISH experiments with super-stretched chromosomes from barley, wheat, rye and chickpea, hybridised with 45S and 5S ribosomal DNAs and the [GAA]n microsatellite, the [TTTAGGG]n telomeric repeat and a bacterial artificial chromosome (BAC) clone as probes. FISH signals on stretched chromosomes were brighter than those on the untreated control, resulting from better accessibility of the stretched chromatin and maximum observed sensitivity of 1 kbp. Spatial resolution of neighbouring loci was improved down to 70 kbp as compared to 5-10 Mbp after FISH on mitotic chromosomes, revealing details of adjacent DNA sequences hitherto not obtained with any other method. Stretched chromosomes are advantageous over extended DNA fibres from interphase nuclei as targets for FISH studies because they still retain chromosomal integrity. Although the method is confined to species for which chromosome flow sorting has been developed, it provides a unique system for controlling stretching degree of mitotic chromosomes and high-resolution bar-code FISH.

Recovery of Coastal Fauna after the 2011 Tsunami in Japan as Determined by Bimonthly Underwater Visual Censuses Conducted over Five Years

PubMed Central

Masuda, Reiji; Hatakeyama, Makoto; Yokoyama, Katsuhide; Tanaka, Masaru

2016-01-01

Massive tsunamis induce catastrophic disturbance in marine ecosystems, yet they can provide unique opportunities to observe the process of regeneration. Here, we report the recovery of fauna after the 2011 tsunami in northeast Japan based on underwater visual censuses performed every two months over five years. Both total fish abundance and species richness increased from the first to the second year after the tsunami followed by stabilization in the following years. Short-lived fish, such as the banded goby Pterogobius elapoides, were relatively abundant in the first two years, whereas long-lived species, such as the black rockfish Sebastes cheni, increased in the latter half of the survey period. Tropical fish species were recorded only in the second and third years after the tsunami. The body size of long-lived fish increased during the survey period resulting in a gradual increase of total fish biomass. The recovery of fish assemblages was slow at one site located in the inner bay, where the impact of the tsunami was the strongest. Apart from fish, blooms of the moon jellyfish Aurelia sp. occurred only in the first two years after the tsunami, whereas the abundances of sea cucumber Apostichopus japonicus and abalone Haliotis discus hannai increased after the second year. Although we lack quantitative data prior to the tsunami, we conclude that it takes approximately three years for coastal reef fish assemblages to recover from a heavy disturbance such as a tsunami and that the recovery is dependent on species-specific life span and habitat. PMID:27942028

Distribution and movement of humpback chub in the Colorado River, Grand Canyon, based on recaptures

USGS Publications Warehouse

Paukert, C.P.; Coggins, L.G.; Flaccus, C.E.

2006-01-01

Mark-recapture data from the federally endangered humpback chub Gila cypha in the Colorado River, Grand Canyon, were analyzed from 1989 to 2002 to determine large-scale movement patterns and distribution. A total of 14,674 recaptures from 7,127 unique fish were documented; 87% of the recaptures occurred in the same main-stem river reach or tributary as the original captures, suggesting restricted distribution by most fish. A total of 99% of all recaptures were from in and around the Little Colorado River (LCR), a tributary of the Colorado River and primary aggregation and spawning location of humpback chub in Grand Canyon. Time at liberty averaged 394 d, but some fish were recaptured near their main-stem capture location over 10 years later. Proportionally fewer large (>300-mm) humpback chub exhibited restricted distribution than small (<200-mm) fish. However, several fish did move more than 154 km throughout Grand Canyon between capture and recapture, suggesting that limited movement occurs throughout Grand Canyon. The majority of the recaptured fish remained in or returned to the LCR or the Colorado River near the LCR. Although many large-river fishes exhibit extensive migrations to fulfill their life history requirements, most of the humpback chub in Grand Canyon appear to remain in or come back to the LCR and LCR confluence across multiple sizes and time scales. Detecting trends in the overall abundance of this endangered fish in Grand Canyon can probably be accomplished by monitoring the area in and around the LCR.

Prevalence and Population Structure of Vibrio vulnificus on Fishes from the Northern Gulf of Mexico

PubMed Central

Tao, Zhen; Larsen, Andrea M.; Bullard, Stephen A.; Wright, Anita C.

2012-01-01

The prevalence of Vibrio vulnificus on the external surfaces of fish from the northern Gulf of Mexico was determined in this study. A collection of 242 fish comprising 28 species was analyzed during the course of 12 sampling trips over a 16-month period. The prevalence of V. vulnificus was 37% but increased up to 69% in summer. A positive correlation was found between the percentages of V. vulnificus-positive fish and water temperatures, while salinity and V. vulnificus-positive fish prevalence were inversely correlated. A general lineal model (percent V. vulnificus-positive fish = 0.5930 − 0.02818 × salinity + 0.01406 × water temperature) was applied to best fit the data. Analysis of the population structure was carried out using 244 isolates recovered from fish. Ascription to 16S rRNA gene types indicated that 157 isolates were type A (62%), 72 (29%) were type B, and 22 (9%) were type AB. The percentage of type B isolates, considered to have greater virulence potential, was higher than that previously reported in oyster samples from the northern Gulf of Mexico. Amplified fragment length polymorphism (AFLP) was used to resolve the genetic diversity within the species. One hundred twenty-one unique AFLP profiles were found among all analyzed isolates, resulting in a calculated Simpson's index of diversity of 0.991. AFLP profiles were not grouped on the basis of collection date, fish species, temperature, or salinity, but isolates were clustered into two main groups that correlated precisely with 16S rRNA gene type. The population of V. vulnificus associated with fishes from the northern Gulf of Mexico is heterogeneous and includes strains of great virulence potential. PMID:22923394

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

PubMed

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

2016-07-01

Invasive species pose a major threat to aquatic ecosystems. Their impact can be particularly severe in tropical regions, like those in northern Australia, where >20 invasive fish species are recorded. In temperate regions, environmental DNA (eDNA) technology is gaining momentum as a tool to detect aquatic pests, but the technology's effectiveness has not been fully explored in tropical systems with their unique climatic challenges (i.e. high turbidity, temperatures and ultraviolet light). In this study, we modified conventional eDNA protocols for use in tropical environments using the invasive fish, Mozambique tilapia (Oreochromis mossambicus) as a detection model. We evaluated the effects of high water temperatures and fish density on the detection of tilapia eDNA, using filters with larger pores to facilitate filtration. Large-pore filters (20 μm) were effective in filtering turbid waters and retaining sufficient eDNA, whilst achieving filtration times of 2-3 min per 2-L sample. High water temperatures, often experienced in the tropics (23, 29, 35 °C), did not affect eDNA degradation rates, although high temperatures (35 °C) did significantly increase fish eDNA shedding rates. We established a minimum detection limit for tilapia (1 fish/0.4 megalitres/after 4 days) and found that low water flow (3.17 L/s) into ponds with high fish density (>16 fish/0.4 megalitres) did not affect eDNA detection. These results demonstrate that eDNA technology can be effectively used in tropical ecosystems to detect invasive fish species. © 2016 John Wiley & Sons Ltd.

Theme and variations: amphibious air-breathing intertidal fishes.

PubMed

Martin, K L

2014-03-01

Over 70 species of intertidal fishes from 12 families breathe air while emerging from water. Amphibious intertidal fishes generally have no specialized air-breathing organ but rely on vascularized mucosae and cutaneous surfaces in air to exchange both oxygen and carbon dioxide. They differ from air-breathing freshwater fishes in morphology, physiology, ecology and behaviour. Air breathing and terrestrial activity are present to varying degrees in intertidal fish species, correlated with the tidal height of their habitat. The gradient of amphibious lifestyle includes passive remainers that stay in the intertidal zone as tides ebb, active emergers that deliberately leave water in response to poor aquatic conditions and highly mobile amphibious skipper fishes that may spend more time out of water than in it. Normal terrestrial activity is usually aerobic and metabolic rates in air and water are similar. Anaerobic metabolism may be employed during forced exercise or when exposed to aquatic hypoxia. Adaptations for amphibious life include reductions in gill surface area, increased reliance on the skin for respiration and ion exchange, high affinity of haemoglobin for oxygen and adjustments to ventilation and metabolism while in air. Intertidal fishes remain close to water and do not travel far terrestrially, and are unlikely to migrate or colonize new habitats at present, although in the past this may have happened. Many fish species spawn in the intertidal zone, including some that do not breathe air, as eggs and embryos that develop in the intertidal zone benefit from tidal air emergence. With air breathing, amphibious intertidal fishes survive in a variable habitat with minimal adjustments to existing structures. Closely related species in different microhabitats provide unique opportunities for comparative studies. © 2013 The Fisheries Society of the British Isles.

Dynamic catch trends in the history of recreational spearfishing in Australia.

PubMed

Young, Matthew A L; Foale, Simon; Bellwood, David R

2015-06-01

The sustained decline in marine fisheries worldwide underscores the need to understand and monitor fisheries trends and fisher behavior. Recreational fisheries are unique in that they are not subject to the typical drivers that influence commercial and artisanal fisheries (e.g., markets or food security). Nevertheless, although exposed to a different set of drivers (i.e., interest or relaxation), recreational fisheries can contribute to fishery declines. Recreational fisheries are also difficult to assess due to an absence of past monitoring and traditional fisheries data. Therefore, we utilized a nontraditional data source (a chronology of spearfishing publications) to document historical trends in recreational spearfishing in Australia between 1952 and 2009. We extracted data on reported fish captures, advertising, and spearfisher commentary and used regression models and ordination analyses to assess historical change. The proportion of coastal fish captures reported declined approximately 80%, whereas the proportion of coral reef and pelagic fish reports increased 1750% and 560%, respectively. Catch composition shifted markedly from coastal temperate or subtropical fishes during the 1950s to 1970s to coral reef and pelagic species in the 1990s to 2000s. Advertising data and commentary by spearfishers indicated that pelagic fish species became desired targets. The mean weight of trophy coral reef fishes also declined significantly over the study period (from approximately 30-8 kg). Recreational fishing presents a highly dynamic social-ecological interface and a challenge for management. Our results emphasize the need for regulatory agencies to work closely with recreational fishing bodies to observe fisher behavior, detect shifts in target species or fishing intensity, and adapt regulatory measures. © 2015 Society for Conservation Biology.

The Real Bounty: Marine Biodiversity in the Pitcairn Islands

PubMed Central

Friedlander, Alan M.; Caselle, Jennifer E.; Ballesteros, Enric; Brown, Eric K.; Turchik, Alan; Sala, Enric

2014-01-01

In 2012 we conducted an integrated ecological assessment of the marine environment of the Pitcairn Islands, which are four of the most remote islands in the world. The islands and atolls (Ducie, Henderson, Oeno, and Pitcairn) are situated in the central South Pacific, halfway between New Zealand and South America. We surveyed algae, corals, mobile invertebrates, and fishes at 97 sites between 5 and 30 m depth, and found 51 new records for algae, 23 for corals, and 15 for fishes. The structure of the ecological communities was correlated with age, isolation, and geomorphology of the four islands. Coral and algal assemblages were significantly different among islands with Ducie having the highest coral cover (56%) and Pitcairn dominated by erect macroalgae (42%). Fish biomass was dominated by top predators at Ducie (62% of total fish biomass) and at Henderson (35%). Herbivorous fishes dominated at Pitcairn, while Oeno showed a balanced fish trophic structure. We found high levels of regional endemism in the fish assemblages across the islands (45%), with the highest level observed at Ducie (56% by number). We conducted the first surveys of the deep habitats around the Pitcairn Islands using drop-cameras at 21 sites from depths of 78 to 1,585 m. We observed 57 fish species from the drop-cams, including rare species such as the false catshark (Pseudotriakis microdon) and several new undescribed species. In addition, we made observations of typically shallow reef sharks and other reef fishes at depths down to 300 m. Our findings highlight the uniqueness and high biodiversity value of the Pitcairn Islands as one of the least impacted in the Pacific, and suggest the need for immediate protection. PMID:24963808

Community assembly of a euryhaline fish microbiome during salinity acclimation.

PubMed

Schmidt, Victor T; Smith, Katherine F; Melvin, Donald W; Amaral-Zettler, Linda A

2015-05-01

Microbiomes play a critical role in promoting a range of host functions. Microbiome function, in turn, is dependent on its community composition. Yet, how microbiome taxa are assembled from their regional species pool remains unclear. Many possible drivers have been hypothesized, including deterministic processes of competition, stochastic processes of colonization and migration, and physiological 'host-effect' habitat filters. The contribution of each to assembly in nascent or perturbed microbiomes is important for understanding host-microbe interactions and host health. In this study, we characterized the bacterial communities in a euryhaline fish and the surrounding tank water during salinity acclimation. To assess the relative influence of stochastic versus deterministic processes in fish microbiome assembly, we manipulated the bacterial species pool around each fish by changing the salinity of aquarium water. Our results show a complete and repeatable turnover of dominant bacterial taxa in the microbiomes from individuals of the same species after acclimation to the same salinity. We show that changes in fish microbiomes are not correlated with corresponding changes to abundant taxa in tank water communities and that the dominant taxa in fish microbiomes are rare in the aquatic surroundings, and vice versa. Our results suggest that bacterial taxa best able to compete within the unique host environment at a given salinity appropriate the most niche space, independent of their relative abundance in tank water communities. In this experiment, deterministic processes appear to drive fish microbiome assembly, with little evidence for stochastic colonization. © 2015 John Wiley & Sons Ltd.

Transgenerational marking of freshwater fishes with enriched stable isotopes: a tool for fisheries management and research.

PubMed

Munro, A R; Gillanders, B M; Thurstan, S; Crook, D A; Sanger, A C

2009-08-01

A promising new method of marking larval freshwater fishes with enriched stable isotopes by means of injecting the maternal parent with the marking agent was investigated. The (138)Ba:(137)Ba ratios in the otoliths of larval golden perch Macquaria ambigua were compared to determine the effect of injecting female broodstock with different dosages of enriched (137)Ba at various times before spawning. There was 100% mark success in the progeny of fish injected with 20 microg g(-1) of enriched (137)Ba 24 h before inducing spawning with hormones and 40 microg g(-1) administered at the same time as inducement of spawning. Injection of 40 microg g(-1) enriched (137)Ba 21 days before spawning resulted in only 81% mark success and suggests rapid elimination of barium in M. ambigua. Injection with enriched (137)Ba did not significantly affect the fertilization rate, number of fertilized eggs or hatching rate compared with long-term hatchery records. These results suggest that transgenerational marking is an effective and affordable means of mass-marking larval fishes. Thousands of larval fishes can be permanently marked with a unique artificial isotopic mark via a single injection into the maternal parent, thus avoiding the handling of individual fishes or having to deal with chemical baths. Because no single mark or tagging method is suitable for all situations, transgenerational marking with enriched stable isotopes provides another method for researchers and managers to discriminate both hatchery-reared and wild fishes.

Mitochondrial DNA identification of game and harvested freshwater fish species.

PubMed

Kyle, C J; Wilson, C C

2007-02-14

The use of DNA in forensics has grown rapidly for human applications along with the concomitant development of bioinformatics and demographic databases to help fully realize the potential of this molecular information. Similar techniques are also used routinely in many wildlife cases, such as species identification in food products, poaching and the illegal trade of endangered species. The use of molecular techniques in forensic cases related to wildlife and the development of associated databases has, however, mainly focused on large mammals with the exception of a few high-profile species. There is a need to develop similar databases for aquatic species for fisheries enforcement, given the large number of exploited and endangered fish species, the intensity of exploitation, and challenges in identifying species and their derived products. We sequenced a 500bp fragment of the mitochondrial cytochrome b gene from representative individuals from 26 harvested fish taxa from Ontario, Canada, focusing on species that support major commercial and recreational fisheries. Ontario provides a unique model system for the development of a fish species database, as the province contains an evolutionarily diverse array of freshwater fish families representing more than one third of all freshwater fish in Canada. Inter- and intraspecific sequence comparisons using phylogenetic analysis and a BLAST search algorithm provided rigorous statistical metrics for species identification. This methodology and these data will aid in fisheries enforcement, providing a tool to easily and accurately identify fish species in enforcement investigations that would have otherwise been difficult or impossible to pursue.

Survey of n-3 and n-6 polyunsaturated fatty acids in fish and fish products

PubMed Central

2012-01-01

Background The imbalance of the n-3/n-6 ratio in the Western diet is characterised by a low intake of n-3 long-chain (LC) PUFA and a concurrent high intake of n-6 PUFA. Fish, in particular marine fish, is a unique source of n-3 LC PUFA. However, FA composition of consumed fish changed, due to the increasing usage of n-6 PUFA-rich vegetable oils in aquaculture feed and in fish processing (frying) which both lead to a further shift in n-6 PUFA to the detriment of n-3 LC PUFA. The aim of this study was to determine the ratio of n-3/n-6 including the contents of EPA and DHA in fish fillets and fish products from the German market (n=123). Furthermore, the study focussed on the FA content in farmed salmon compared to wild salmon as well as in processed Alaska pollock fillet, e.g., fish fingers. Results Total fat and FA content in fish products varied considerably depending on fish species, feed management, and food processing. Mackerel, herring and trout fillets characteristically contained adequate dietary amounts of absolute EPA and DHA, due to their high fat contents. However, despite a lower fat content, tuna, pollock, and Alaska pollock can contribute considerable amounts of EPA and DHA to the human supply. Farmed salmon are an appropriate source of EPA and DHA owing to their higher fat content compared to wild salmon (12.3 vs. 2.1 wt %), however with elevated SFA, n-9 and n-6 FA contents representing the use of vegetable oils and oilseeds in aquaculture feed. The n-3/n-6 ratio was deteriorated (2.9 vs. 12.4) but still acceptable. Compared to pure fish fillets, breaded and pre-fried Alaska pollock fillet contained extraordinarily high fat and n-6 PUFA levels. Conclusions Since fish species vary with respect to their n-3 LC PUFA contents, eating a variety of fish is advisable. High n-6 PUFA containing pre-fried fish support the imbalance of n-3/n-6 ratio in the Western diet. Thus, consumption of pure fish fillets is to be favoured. The lower n-3 PUFA portion in farmed fish can be offset by the higher fat content, however, with an unfavourable FA distribution compared to wild fellows. PMID:23110317

Survey of n-3 and n-6 polyunsaturated fatty acids in fish and fish products.

PubMed

Strobel, Claudia; Jahreis, Gerhard; Kuhnt, Katrin

2012-10-30

The imbalance of the n-3/n-6 ratio in the Western diet is characterised by a low intake of n-3 long-chain (LC) PUFA and a concurrent high intake of n-6 PUFA. Fish, in particular marine fish, is a unique source of n-3 LC PUFA. However, FA composition of consumed fish changed, due to the increasing usage of n-6 PUFA-rich vegetable oils in aquaculture feed and in fish processing (frying) which both lead to a further shift in n-6 PUFA to the detriment of n-3 LC PUFA.The aim of this study was to determine the ratio of n-3/n-6 including the contents of EPA and DHA in fish fillets and fish products from the German market (n=123). Furthermore, the study focussed on the FA content in farmed salmon compared to wild salmon as well as in processed Alaska pollock fillet, e.g., fish fingers. Total fat and FA content in fish products varied considerably depending on fish species, feed management, and food processing. Mackerel, herring and trout fillets characteristically contained adequate dietary amounts of absolute EPA and DHA, due to their high fat contents. However, despite a lower fat content, tuna, pollock, and Alaska pollock can contribute considerable amounts of EPA and DHA to the human supply.Farmed salmon are an appropriate source of EPA and DHA owing to their higher fat content compared to wild salmon (12.3 vs. 2.1 wt %), however with elevated SFA, n-9 and n-6 FA contents representing the use of vegetable oils and oilseeds in aquaculture feed. The n-3/n-6 ratio was deteriorated (2.9 vs. 12.4) but still acceptable. Compared to pure fish fillets, breaded and pre-fried Alaska pollock fillet contained extraordinarily high fat and n-6 PUFA levels. Since fish species vary with respect to their n-3 LC PUFA contents, eating a variety of fish is advisable. High n-6 PUFA containing pre-fried fish support the imbalance of n-3/n-6 ratio in the Western diet. Thus, consumption of pure fish fillets is to be favoured. The lower n-3 PUFA portion in farmed fish can be offset by the higher fat content, however, with an unfavourable FA distribution compared to wild fellows.

Gene expression fingerprints of largemouth bass (Micropterus salmoides) exposed to pulp and paper mill effluents.

PubMed

Denslow, Nancy D; Kocerha, Jannet; Sepúlveda, Maria S; Gross, Timothy; Holm, Stewart E

2004-08-18

Effluents from pulp and paper mills that historically have used elemental chlorine in the bleaching process have been implicated in inhibiting reproduction in fish. Compounds with estrogenic and androgenic binding affinities have been found in these effluents, suggesting that the impairment of reproduction is through an endocrine-related mode of action. To date, a great deal of attention has been paid to phytoestrogens and resin acids that are present in mill process streams as a result of pulping trees. Estrogen and estrogen mimics interact directly with the estrogen receptor and have near immediate effects on gene transcription by turning on the expression of a unique set of genes. Using differential display (DD) RT-PCR, we examined changes in gene expression induced by exposure to paper mill effluents. Largemouth bass were exposed to 0, 10, 20, 40, and 80% paper mill effluent concentrations in large flow-through tanks for varied periods of time including 7, 28 or 56 days. Plasma hormone levels in males and females and plasma vitellogenin (Vtg) in females decreased with dose and time. Measurements of changes in gene expression using DD RT-PCR suggest that the gene expression patterns of male fish do not change much with exposure, except for the induction of a few genes including CYP 1A, a protein that is induced through the action of the Ah receptor in response to dioxin and similar polyaromatic hydrocarbons. However, in the case of females, exposure to these effluents resulted in an up-regulation of CYP 1A that was accompanied by a generalized down-regulation of genes normally expressed during the reproductive season. These antiestrogenic changes are in agreement with previous studies in bass exposed to these effluents, and could result in decreased reproductive success in affected populations.

Elevated PDGFRB gene copy number gain (CNG) is prognostic for improved survival outcomes in resected malignant pleural mesothelioma

PubMed Central

Tsao, Anne S.; Harun, Nusrat; Fujimoto, Junya; Devito, Vikki; Lee, J. Jack; Kuhn, Elisabetta; Mehran, Reza; Rice, David; Moran, Cesar; Hong, Waun Ki; Shen, Li; Suraokar, Milind; Wistuba, Ignacio

2014-01-01

Background PDGF/PDGFR pathway has been implicated in malignant pleural mesothelioma (MPM) carcinogenesis and evidence suggests autocrine mechanisms of proliferation. We sought to evaluate the incidence of PDGFRB gene copy number gain (CNG) by fluorescence in situ hybridization (FISH) and PDGFR pathway protein expression by immunohistochemistry (IHC) and correlate it to patient clinical outcome. Methods 88 archived tumor blocks from resected MPM with full clinical information were used to perform IHC biomarkers (PDGFRα, PDGFRβ, p-PDGFRβ) and FISH analysis of PDGFRB gene CNG. Spearman's rank correlation, Wilcoxon rank-sum test, Kruskal-Wallis test, BLiP plots, and Kaplan-Meier method were used to analyze the biomarkers and correlation to clinical outcome. Results Several correlations between the IHC biomarkers were seen; however, none correlated to clinically relevant patient demographics or histology. In the CNG analysis, PDGFRB gene CNG in > 10% of tumor cells had lower cytoplasmic p-PDGFRβ (p=0.029), while PDGFRB gene CNG in > 40% of tumor cells had a higher cytoplasmic PDGFRβ (p=0.04). PDGFRB gene CNG status did not associate with patient demographics or tumor characteristics. PDGFR pathway IHC biomarkers did not associate with survival outcomes. However, patients with PDGFRB CNG > 40% of tumor cells had improved relapse-free survival [HR 0.25 (95% CI 0.09, 0.72), p=0.0096] and improved overall survival [HR 0.32 (95% CI 0.11, 0.89), p=0.029]. Conclusions PDGFRB CNG > 40% of MPM tumor cells is a potential prognostic biomarker for surgery and may identify a unique population of mesothelioma patients. Future validation of this biomarker in prospective trials is needed. PMID:24747001

Trophic structure and avian communities across a salinity gradient in evaporation ponds of the San Francisco Bay estuary

USGS Publications Warehouse

Takekawa, John Y.; Miles, A.K.; Schoellhamer, D.H.; Athearn, N.D.; Saiki, M.K.; Duffy, W.D.; Kleinschmidt, S.; Shellenbarger, G.G.; Jannusch, C.A.

2006-01-01

Commercial salt evaporation ponds comprise a large proportion of baylands adjacent to the San Francisco Bay, a highly urbanized estuary. In the past two centuries, more than 79% of the historic tidal wetlands in this estuary have been lost. Resource management agencies have acquired more than 10 000 ha of commercial salt ponds with plans to undertake one of the largest wetland restoration projects in North America. However, these plans have created debate about the ecological importance of salt ponds for migratory bird communities in western North America. Salt ponds are unique mesohaline (5–18 g l−1) to hyperhaline (> 40 g l−1) wetlands, but little is known of their ecological structure or value. Thus, we studied decommissioned salt ponds in the North Bay of the San Francisco Bay estuary from January 1999 through November 2001. We measured water quality parameters (salinity, DO, pH, temperature), nutrient concentrations, primary productivity, zooplankton, macroinvertebrates, fish, and birds across a range of salinities from 24 to 264 g l−1. Our studies documented how unique limnological characteristics of salt ponds were related to nutrient levels, primary productivity rates, invertebrate biomass and taxa richness, prey fish, and avian predator numbers. Salt ponds were shown to have unique trophic and physical attributes that supported large numbers of migratory birds. Therefore, managers should carefully weigh the benefits of increasing habitat for native tidal marsh species with the costs of losing these unique hypersaline systems.

Structure and function of the hearts of lizards and snakes.

PubMed

Jensen, Bjarke; Moorman, Antoon F M; Wang, Tobias

2014-05-01

With approximately 7000 species, snakes and lizards, collectively known as squamates, are by far the most species-rich group of reptiles. It was from reptile-like ancestors that mammals and birds evolved and squamates can be viewed as phylogenetically positioned between them and fishes. Hence, their hearts have been studied for more than a century yielding insights into the group itself and into the independent evolution of the fully divided four-chambered hearts of mammals and birds. Structurally the heart is complex and debates persist on rudimentary issues such as identifying structures critical to understanding ventricle function. In seeking to resolve these controversies we have generated three-dimensional (3D) models in portable digital format (pdf) of the anaconda and anole lizard hearts ('typical' squamate hearts) and the uniquely specialized python heart with comprehensive annotations of structures and cavities. We review the anatomy and physiology of squamate hearts in general and emphasize the unique features of pythonid and varanid lizard hearts that endow them with mammal-like blood pressures. Excluding pythons and varanid lizards it is concluded that the squamate heart has a highly consistent design including a disproportionately large right side (systemic venous) probably due to prevailing pulmonary bypass (intraventricular shunting). Unfortunately, investigations on rudimentary features are sparse. We therefore point out gaps in our knowledge, such as the size and functional importance of the coronary vasculature and of the first cardiac chamber, the sinus venosus, and highlight areas with implications for vertebrate cardiac evolution. © 2013 The Authors. Biological Reviews © 2013 Cambridge Philosophical Society.

Revisiting Ramakrishnan's approach to relatively. [Velocity addition theorem uniqueness

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nandi, K.K.; Shankara, T.S.

The conditions under which the velocity addition theorem (VAT) is formulated by Ramakrishnan gave rise to doubts about the uniqueness of the theorem. These conditions are rediscussed with reference to their algebraic and experimental implications. 9 references.

Fish with Chips: Tracking Reef Fish Movements to Evaluate Size and Connectivity of Caribbean Marine Protected Areas

PubMed Central

Pittman, Simon J.; Monaco, Mark E.; Friedlander, Alan M.; Legare, Bryan; Nemeth, Richard S.; Kendall, Matthew S.; Poti, Matthew; Clark, Randall D.; Wedding, Lisa M.; Caldow, Chris

2014-01-01

Coral reefs and associated fish populations have experienced rapid decline in the Caribbean region and marine protected areas (MPAs) have been widely implemented to address this decline. The performance of no-take MPAs (i.e., marine reserves) for protecting and rebuilding fish populations is influenced by the movement of animals within and across their boundaries. Very little is known about Caribbean reef fish movements creating a critical knowledge gap that can impede effective MPA design, performance and evaluation. Using miniature implanted acoustic transmitters and a fixed acoustic receiver array, we address three key questions: How far can reef fish move? Does connectivity exist between adjacent MPAs? Does existing MPA size match the spatial scale of reef fish movements? We show that many reef fishes are capable of traveling far greater distances and in shorter duration than was previously known. Across the Puerto Rican Shelf, more than half of our 163 tagged fish (18 species of 10 families) moved distances greater than 1 km with three fish moving more than 10 km in a single day and a quarter spending time outside of MPAs. We provide direct evidence of ecological connectivity across a network of MPAs, including estimated movements of more than 40 km connecting a nearshore MPA with a shelf-edge spawning aggregation. Most tagged fish showed high fidelity to MPAs, but also spent time outside MPAs, potentially contributing to spillover. Three-quarters of our fish were capable of traveling distances that would take them beyond the protection offered by at least 40–64% of the existing eastern Caribbean MPAs. We recommend that key species movement patterns be used to inform and evaluate MPA functionality and design, particularly size and shape. A re-scaling of our perception of Caribbean reef fish mobility and habitat use is imperative, with important implications for ecology and management effectiveness. PMID:24797815

[Spatio-temporal dynamics of fishing effort in a multi-species artisanal diving fishery and its effects on catch variability: insights for sustainable management].

PubMed

Naranjo Madrigall, Helven; Salas Marquez, Silvia

2014-12-01

Artisanal diving fisheries are a source of income, employment and food security of coastal areas in many countries. Understanding the dynamics of these fisheries, including the spatial and temporal dynamics of fishing effort, gears and species can help to address the challenges involved in fisheries management. We aimed to analyze the differences in fishing strategies undertaken by fishers that use two different diving methods (hookah and free diving), the conditions and their potential impacts on catches when adjustments to those strategies are applied over time. For this, detailed information of fishing operations from artisanal boats in the North Pacific coast of Costa Rica was analyzed in two fishing seasons (2007-2008 and 2011-2012). Data were collected by onboard observers (fishing site, fishing time, species composition, depth and visibility). Additionally, interviews with divers were applied to obtain information of price per species, species volume and fishing operations. From the total number of trips during both seasons, hookah diving was represented by a sample size of 69.3%, while free diving, with a sample of 41.9%. More than 15 species were identified in each fishing season. Nevertheless, three categories had substantial contributions in both seasons with differences in the proportions for each case: green lobster (Panulirus gracilis), octopus (Octopus sp.) and parrotfish (Scarus perrico and S. ghobban). It is worth noting that an important proportion of catch was retained by fishers for personal consumption purposes, including species of high commercial value. Additional night diving activity, increased the number of dives from one season to another. Besides, cooperation processes in free diving fishing operations, and changes in fishing effort between seasons, defined important changes in fishing strategies. Potential causes of changes in fishing strategies and the implications for management to ensure the sustainability of these fisheries in the long term are discussed.

Fish with chips: tracking reef fish movements to evaluate size and connectivity of Caribbean marine protected areas.

PubMed

Pittman, Simon J; Monaco, Mark E; Friedlander, Alan M; Legare, Bryan; Nemeth, Richard S; Kendall, Matthew S; Poti, Matthew; Clark, Randall D; Wedding, Lisa M; Caldow, Chris

2014-01-01

Coral reefs and associated fish populations have experienced rapid decline in the Caribbean region and marine protected areas (MPAs) have been widely implemented to address this decline. The performance of no-take MPAs (i.e., marine reserves) for protecting and rebuilding fish populations is influenced by the movement of animals within and across their boundaries. Very little is known about Caribbean reef fish movements creating a critical knowledge gap that can impede effective MPA design, performance and evaluation. Using miniature implanted acoustic transmitters and a fixed acoustic receiver array, we address three key questions: How far can reef fish move? Does connectivity exist between adjacent MPAs? Does existing MPA size match the spatial scale of reef fish movements? We show that many reef fishes are capable of traveling far greater distances and in shorter duration than was previously known. Across the Puerto Rican Shelf, more than half of our 163 tagged fish (18 species of 10 families) moved distances greater than 1 km with three fish moving more than 10 km in a single day and a quarter spending time outside of MPAs. We provide direct evidence of ecological connectivity across a network of MPAs, including estimated movements of more than 40 km connecting a nearshore MPA with a shelf-edge spawning aggregation. Most tagged fish showed high fidelity to MPAs, but also spent time outside MPAs, potentially contributing to spillover. Three-quarters of our fish were capable of traveling distances that would take them beyond the protection offered by at least 40-64% of the existing eastern Caribbean MPAs. We recommend that key species movement patterns be used to inform and evaluate MPA functionality and design, particularly size and shape. A re-scaling of our perception of Caribbean reef fish mobility and habitat use is imperative, with important implications for ecology and management effectiveness.

SEM/EDS and optical microscopy analyses of microplastics in ocean trawl and fish guts.

PubMed

Wang, Zhong-Min; Wagner, Jeff; Ghosal, Sutapa; Bedi, Gagandeep; Wall, Stephen

2017-12-15

Microplastic particles from Atlantic and Pacific Ocean trawls, lab-fed fish guts and ocean fish guts have been characterized using optical microscopy and SEM/EDS in terms of size, morphology, and chemistry. We assessed whether these measurements could serve as a rapid screening process for subsequent identification of the likely microplastic candidates by micro-spectroscopy. Optical microscopy enabled morphological classification of the types of particles or fibers present in the sample, as well as the quantification of particle size ranges and fiber lengths. SEM/EDS analysis was used to rule out non-plastic particles and screen the prepared samples for potential microplastic, based on their element signatures and surface characteristics. Chlorinated plastics such as polyvinyl chloride (PVC) could be easily identified with SEM/EDS due to their unique elemental signatures including chlorine, as could mineral species that are falsely identified as plastics by optical microscopy. Particle morphology determined by optical microscopy and SEM suggests the fish ingested particles contained both degradation fragments from larger plastic pieces and also manufactured microplastics. SEM images of microplastic particle surfaces revealed characteristic cracks consistent with environmental exposure, as well as pigment particles consistent with manufactured materials. Most of the microplastic surfaces in the fish guts and ocean trawls were covered with biofilms, radiolarians, and crustaceans. Many of the fish stomachs contained micro-shell pieces which visually resembled microplastics. Copyright © 2017 Elsevier B.V. All rights reserved.

Telomeres and NextGen CO-FISH: Directional Genomic Hybridization (Telo-dGH™).

PubMed

McKenna, Miles J; Robinson, Erin; Goodwin, Edwin H; Cornforth, Michael N; Bailey, Susan M

2017-01-01

The cytogenomics-based methodology of Directional Genomic Hybridization (dGH™) emerged from the concept of strand-specific hybridization, first made possible by Chromosome Orientation FISH (CO-FISH), the utility of which was demonstrated in a variety of early applications, often involving telomeres. Similar to standard whole chromosome painting (FISH), dGH™ is capable of identifying inter-chromosomal rearrangements (translocations between chromosomes), but its distinctive strength stems from its ability to detect intra-chromosomal rearrangements (inversions within chromosomes), and to do so at higher resolution than previously possible. dGH™ brings together the strand specificity and directionality of CO-FISH with sophisticated bioinformatics-based oligonucleotide probe design to unique sequences. dGH™ serves not only as a powerful discovery tool-capable of interrogating the entire genome at the megabase level-it can also be used for high-resolution targeted detection of known inversions, a valuable attribute in both research and clinical settings. Detection of chromosomal inversions, particularly small ones, poses a formidable challenge for more traditional cytogenetic approaches, especially when they occur near the ends or telomeric regions. Here, we describe Telo-dGH™, a strand-specific scheme that utilizes dGH™ in combination with telomere CO-FISH to differentiate between terminal exchange events, specifically terminal inversions, and an altogether different form of genetic recombination that often occurs near the telomere, namely sister chromatid exchange (SCE).

Histology of the first fish

USGS Publications Warehouse

Smith, M.P.; Sansom, I.J.; Repetski, J.E.

1996-01-01

THE first description of Anatolepis Bockelie & Fortey was from early Ordovician sediments of Ny Friesland, Spitsbergen1,2, but the genus is now known from many localities in North America and Greenland, ranging in age from the Late Cambrian period to the Early Ordovician3-6. Although initially interpreted as an agnathan fish2,3 that predated other representatives7, this has been widely disputed because the available histological data were unconvincing6,8-10 and the scales fell outside the known morphological range of other accepted early vertebrates9-11. Further doubt was cast upon the vertebrate affinity of Anatolepis when specimens from East Greenland were interpreted as the cuticular fragments of aglaspid arthropods6, although this interpretation has also been refuted12. Here we report on the morphology and histology of large collections of Anatolepis, and demonstrate the presence of dentine, a tissue unique to vertebrates, confirming that the taxon is both a vertebrate and the oldest known fish.

Fishes in paleochannels of the Lower Mississippi River alluvial valley: A national treasure

USGS Publications Warehouse

Miranda, Leandro E.

2016-01-01

Fluvial geomorphology of the alluvial valley of the Lower Mississippi River reveals a fascinating history. A prominent occupant of the valley was the Ohio River, estimated to have flowed 25,000 years ago over western Tennessee and Mississippi to join the Mississippi River north of Baton Rouge, Louisiana, 750–800 km south of the present confluence. Over time, shifts in the Mississippi and Ohio rivers toward their contemporary positions have left a legacy of abandoned paleochannels supportive of unique fish assemblages. Relative to channels abandoned in the last 500 years, paleochannels exhibit harsher environmental conditions characteristic of hypereutrophic lakes and support tolerant fish assemblages. Considering their ecological, geological, and historical importance, coupled with their primordial scenery, the hundreds of paleochannels in the valley represent a national treasure. Altogether, these waterscapes are endangered by human activities and would benefit from the conservation attention afforded to our national parks and wildlife refuges.

Evolution of heteromorphic sex chromosomes in the order Aulopiformes.

PubMed

Ota, K; Kobayashi, T; Ueno, K; Gojobori, T

2000-12-23

The fish order Aulopiformes contains both synchronously hermaphroditic and gonochoristic species. From the cytogenetic viewpoint, few reports show that gonochoristic Aulopiformes have heteromorphic sex chromosomes. Because fish in this order give us a unique opportunity to elucidate the evolution of sex chromosomes, it is important to examine a phylogenetic relationship in Aulopiformes by both molecular evolutionary and cytogenetic methods. Thus, we conducted molecular phylogenetic and cytogenetic studies of six Aulopiform species. Our results suggested that hermaphroditic species were evolutionarily derived from gonochoristic species. It follows that the hermaphroditic species might have lost the heteromorphic sex chromosomes during evolution. Here, we suggest a possibility that heteromorphic sex chromosomes can disappear from the genome, even if they have appeared once in evolution. Taking into account Ohno's hypothesis that heteromorphic sex chromosomes might have emerged from autosomes, we propose the hypothesis that heteromorphic sex chromosomes may have undergone repeated events of appearance and disappearance during the course of fish evolution.

Surgical insertions of transmitters and telemetry methods in fisheries research

USGS Publications Warehouse

Wargo Rub, A. Michelle; Jepsen, Niels; Liedtke, Theresa L.; Moser, L; Weber III, E. P. Scott

2015-01-01

Use of electronic transmitter and monitoring systems to track movements of aquatic animals has increased continuously since the inception of these systems in the mid-1950s. The purpose of the present report is to provide information about veterinary principles and their incorporation into surgical implantation procedures for fish. We also intend to provide insight into the unique challenges of field-based aquatic surgical studies. Within this context, 4 aspects of the process for surgical implantation of transmitters in fish (ie, handling, aseptic technique, anesthesia, and implantation) will be described. Effects of surgical insertion of transmitters (ie, tagging) and aspects of the surgical implantation process where collaboration and professional exchanges among nonveterinarian researchers and veterinarians may be most fruitful will be discussed. Although this report focuses on surgical implantation, the principles and protocols described here (other than incision and suture placement) are also applicable to studies that involve injection of transmitters into fish.

FISH-mapping of the 5S rDNA locus in chili peppers (Capsicum-Solanaceae).

PubMed

Aguilera, Patricia M; Debat, Humberto J; Scaldaferro, Marisel A; Martí, Dardo A; Grabiele, Mauro

2016-03-01

We present here the physical mapping of the 5S rDNA locus in six wild and five cultivated taxa of Capsicum by means of a genus-specific FISH probe. In all taxa, a single 5S locus per haploid genome that persistently mapped onto the short arm of a unique metacentric chromosome pair at intercalar position, was found. 5S FISH signals of almost the same size and brightness intensity were observed in all the analyzed taxa. This is the first cytological characterization of the 5S in wild taxa of Capsicum by using a genus-derived probe, and the most exhaustive and comprehensive in the chili peppers up to now. The information provided here will aid the cytomolecular characterization of pepper germplasm to evaluate variability and can be instrumental to integrate physical, genetic and genomic maps already generated in the genus.

Working Conditions, Occupational Injuries, and Health Among Filipino Fish Processing Workers in Dutch Harbor, Alaska

PubMed Central

Garcia, Gabriel Macasiray; de Castro, Butch

2017-01-01

This study explored how unique environmental conditions in Alaska influenced occupational health and safety for Filipino fish processing workers, many of whom migrated from warm locations (e.g., the Philippines, California, and Nevada). In-depth interviews were conducted with 26 Filipino workers in one commercial fish processing company in Dutch Harbor. Results indicated that cold weather interferes with workers’ job performance, increasing their risk for injury and illness, whereas the community’s isolation and rural nature causes loneliness and boredom, resulting in more high-risk behaviors. Other non-environmental factors affecting worker health include roommate and supervisor concerns and culture-specific practices. Findings suggest the importance of job rotation to avoid long exposures to cold temperatures, the value of a designated individual to inform workers about company and community resources that promote healthy lifestyles, and the possible utility of a joint worker–management safety committee. PMID:27729501

Working Conditions, Occupational Injuries, and Health Among Filipino Fish Processing Workers in Dutch Harbor, Alaska.

PubMed

Garcia, Gabriel Macasiray; de Castro, Butch

2017-05-01

This study explored how unique environmental conditions in Alaska influenced occupational health and safety for Filipino fish processing workers, many of whom migrated from warm locations (e.g., the Philippines, California, and Nevada). In-depth interviews were conducted with 26 Filipino workers in one commercial fish processing company in Dutch Harbor. Results indicated that cold weather interferes with workers' job performance, increasing their risk for injury and illness, whereas the community's isolation and rural nature causes loneliness and boredom, resulting in more high-risk behaviors. Other non-environmental factors affecting worker health include roommate and supervisor concerns and culture-specific practices. Findings suggest the importance of job rotation to avoid long exposures to cold temperatures, the value of a designated individual to inform workers about company and community resources that promote healthy lifestyles, and the possible utility of a joint worker-management safety committee.

Genetic and environmental melanoma models in fish

PubMed Central

Patton, E Elizabeth; Mitchell, David L; Nairn, Rodney S

2010-01-01

Experimental animal models are extremely valuable for the study of human diseases, especially those with underlying genetic components. The exploitation of various animal models, from fruitflies to mice, has led to major advances in our understanding of the etiologies of many diseases, including cancer. Cutaneous malignant melanoma is a form of cancer for which both environmental insult (i.e., UV) and hereditary predisposition are major causative factors. Fish melanoma models have been used in studies of both spontaneous and induced melanoma formation. Genetic hybrids between platyfish and swordtails, different species of the genus Xiphophorus, have been studied since the 1920s to identify genetic determinants of pigmentation and melanoma formation. Recently, transgenesis has been used to develop zebrafish and medaka models for melanoma research. This review will provide a historical perspective on the use of fish models in melanoma research, and an updated summary of current and prospective studies using these unique experimental systems. PMID:20230482

Divorce and Family Role Based on Slerek as Traditional Fishing Method in Muncar Banyuwangi Coastal Area

NASA Astrophysics Data System (ADS)

Buhani, Burhani; Surahmi, Sri

2018-05-01

Muncar is a sub district in Banyuwangi which is a ocean fishery area. Banyuwangi has a big number of divorce in marriage. In Muncar there are many separation cases but the number of divorce is zero in 2012. This research is aimed to describe the causes of this phenomena. The research is done by field interview to local people. The interview results are used to describe the causes of the phenomena. The result shows that separation happen because economical and ethnical factor. There is also a unique understanding which come from the philosophy of traditional fishing method that called slerek. This method describe a couple of fishing boat or vessel which represent a role of marriage couple. Slerek did not effect the knowledge and attitude to prevent separation and divorce in Muncar district but can be used as premarital education material.

ECOLOGICAL CRITERIA FOR PRIORITIZATION OF CULVERT REPLACEMENT

EPA Science Inventory

Culvert passage issues are gaining national and international focus, because they are implicated in the decline of particular species and in the more general loss of biodiversity in freshwater ecosystems. In the Pacific Northwest, inadequate fish passage at culverts is recognized...

EE2 Changes Gene Expression in Fathead Minnow Testis

EPA Science Inventory

Environmental estrogens have been implicated in altering reproductive health of aquatic animals. Early studies of sewage treatment effluents attributed the feminization of male fish to exposure to mixtures of natural and synthetic estrogens. One of the most potent estrogens kno...

Genotype-environment interaction in passive avoidance learning of the paradise fish (Macropodus opercularis).

PubMed

Csányi, V; Gervai, J

1985-01-01

Passive dark avoidance conditioning and effects of the presence and absence of a fish-like dummy on the training process were studied in four inbred strains of paradise fish. Strain differences were found in the shuttle activity during habituation trials, and in the sensitivity to the mild electric shock punishment. The presence or absence of the dummy in the punished dark side of the shuttle box had a genotype-dependent effect on the measures taken during the conditioning process. The statistical analysis of the learning curves revealed differences in the way the strains varied in the different environments, i.e. genotype--environment interaction components of variances were identified. The results are discussed in the light of previous investigations and their implication in further genetic analysis.

Bluefish-associated scombroid poisoning. An example of the expanding spectrum of food poisoning from seafood.

PubMed

Etkind, P; Wilson, M E; Gallagher, K; Cournoyer, J

1987-12-18

Five persons who attended a medical conference developed symptoms suggestive of an intoxication after a common meal. Although the symptoms were recognized as typical of scombroid poisoning, no fish of the Scrombridae family had been served. However, food histories implicated bluefish (Pomatomus saltatrix). The initially frozen bluefish had been improperly handled in storage and thawing. Elevated levels of histamine, putrescine, and cadaverine were detected in uncooked samples. This outbreak emphasizes that scombroid-type poisoning (1) can be caused by nonscombroid fish such as bluefish, (2) is probably more common than currently recognized, and (3) may become even more widespread as fish become a larger part of our diet. Physicians who work in conjunction with public health officials can help prevent additional cases and outbreaks.

Commercial fishing industry deaths - forensic issues.

PubMed

Byard, Roger W

2013-04-01

The commercial fishing industry has one of the highest injury and mortality rates of all occupational areas. This results from the nature of the work involving vessels often manned by only a few individuals who are working with heavy-duty equipment in dangerous environments at all hours. Economic pressures may force inappropriately geared vessels to operate further out to sea than is safe. Deaths result from a wide variety of situations involving vessel loss, falls overboard, fire and explosions, cable entanglements and gas exposure. Autopsies are often difficult as there are no diagnostic features of either drowning or hypothermia and features may be obscured by putrefaction and postmortem animal predation. The forensic implications of deaths in the fishing industry are reviewed. Copyright © 2012 Elsevier Ltd and Faculty of Forensic and Legal Medicine. All rights reserved.

Rapid evolution of piRNA pathway in the teleost fish: implication for an adaptation to transposon diversity.

PubMed

Yi, Minhan; Chen, Feng; Luo, Majing; Cheng, Yibin; Zhao, Huabin; Cheng, Hanhua; Zhou, Rongjia

2014-05-19

The Piwi-interacting RNA (piRNA) pathway is responsible for germline specification, gametogenesis, transposon silencing, and genome integrity. Transposable elements can disrupt genome and its functions. However, piRNA pathway evolution and its adaptation to transposon diversity in the teleost fish remain unknown. This article unveils evolutionary scene of piRNA pathway and its association with diverse transposons by systematically comparative analysis on diverse teleost fish genomes. Selective pressure analysis on piRNA pathway and miRNA/siRNA (microRNA/small interfering RNA) pathway genes between teleosts and mammals showed an accelerated evolution of piRNA pathway genes in the teleost lineages, and positive selection on functional PAZ (Piwi/Ago/Zwille) and Tudor domains involved in the Piwi-piRNA/Tudor interaction, suggesting that the amino acid substitutions are adaptive to their functions in piRNA pathway in the teleost fish species. Notably five piRNA pathway genes evolved faster in the swamp eel, a kind of protogynous hermaphrodite fish, than the other teleosts, indicating a differential evolution of piRNA pathway between the swamp eel and other gonochoristic fishes. In addition, genome-wide analysis showed higher diversity of transposons in the teleost fish species compared with mammals. Our results suggest that rapidly evolved piRNA pathway in the teleost fish is likely to be involved in the adaption to transposon diversity. © The Author(s) 2014. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

Middle to late cenozoic geology, hydrography, and fish evolution in the American Southwest

USGS Publications Warehouse

Spencer, J.E.; Smith, G.R.; Dowling, T.E.

2008-01-01

An evaluation of the poorly understood Cenozoic hydrologic history of the American Southwest using combined geological and biological data yields new insights with implications for tectonic evolution. The Mesozoic Cordilleran orogen next to the continental margin of southwestern North America probably formed the continental divide. Mountain building migrated eastward to cause uplift of the Rocky Mountains during the Late Cretaceous to early Tertiary Laramide orogeny. Closed drainage basins that developed between the two mountain belts trapped lake waters containing fish of Atlantic affinity. Oligocene-Miocene tectonic extension fragmented the western mountain belt and created abundant closed basins that gradually filled with sediments and became conduits for dispersal of fishes of both Pacific and Atlantic affinity. Abrupt arrival of the modern Colorado River to the Mojave-Sonora Desert region at ca. 5 Ma provided a new conduit for fish dispersal. Great dissimilarities in modern fish fauna, including differences in their mitochondrial deoxyribonucleic acid (DNA), indicate that late Miocene runoff from the Colorado Plateau did not flow down the Platte or Rio Grande, or through the Lake Bonneville Basin. Fossil fishes from the upper Miocene part of the Bidahochi Formation on the Colorado Plateau have characteristics that reflect a habitat of large, swift-moving waters, and they are closely related to fossil fishes associated with the Snake and Sacramento Rivers. This evidence suggests that influx of fishes from the ancestral Snake River involved a major drainage, not merely small headwater transfers. ?? 2008 The Geological Society of America.

Effects of activity and energy budget balancing algorithm on laboratory performance of a fish bioenergetics model

USGS Publications Warehouse

Madenjian, Charles P.; David, Solomon R.; Pothoven, Steven A.

2012-01-01

We evaluated the performance of the Wisconsin bioenergetics model for lake trout Salvelinus namaycush that were fed ad libitum in laboratory tanks under regimes of low activity and high activity. In addition, we compared model performance under two different model algorithms: (1) balancing the lake trout energy budget on day t based on lake trout energy density on day t and (2) balancing the lake trout energy budget on day t based on lake trout energy density on day t + 1. Results indicated that the model significantly underestimated consumption for both inactive and active lake trout when algorithm 1 was used and that the degree of underestimation was similar for the two activity levels. In contrast, model performance substantially improved when using algorithm 2, as no detectable bias was found in model predictions of consumption for inactive fish and only a slight degree of overestimation was detected for active fish. The energy budget was accurately balanced by using algorithm 2 but not by using algorithm 1. Based on the results of this study, we recommend the use of algorithm 2 to estimate food consumption by fish in the field. Our study results highlight the importance of accurately accounting for changes in fish energy density when balancing the energy budget; furthermore, these results have implications for the science of evaluating fish bioenergetics model performance and for more accurate estimation of food consumption by fish in the field when fish energy density undergoes relatively rapid changes.

Sampling little fish in big rivers: Larval fish detection probabilities in two Lake Erie tributaries and implications for sampling effort and abundance indices

USGS Publications Warehouse

Pritt, Jeremy J.; DuFour, Mark R.; Mayer, Christine M.; Roseman, Edward F.; DeBruyne, Robin L.

2014-01-01

Larval fish are frequently sampled in coastal tributaries to determine factors affecting recruitment, evaluate spawning success, and estimate production from spawning habitats. Imperfect detection of larvae is common, because larval fish are small and unevenly distributed in space and time, and coastal tributaries are often large and heterogeneous. We estimated detection probabilities of larval fish from several taxa in the Maumee and Detroit rivers, the two largest tributaries of Lake Erie. We then demonstrated how accounting for imperfect detection influenced (1) the probability of observing taxa as present relative to sampling effort and (2) abundance indices for larval fish of two Detroit River species. We found that detection probabilities ranged from 0.09 to 0.91 but were always less than 1.0, indicating that imperfect detection is common among taxa and between systems. In general, taxa with high fecundities, small larval length at hatching, and no nesting behaviors had the highest detection probabilities. Also, detection probabilities were higher in the Maumee River than in the Detroit River. Accounting for imperfect detection produced up to fourfold increases in abundance indices for Lake Whitefish Coregonus clupeaformis and Gizzard Shad Dorosoma cepedianum. The effect of accounting for imperfect detection in abundance indices was greatest during periods of low abundance for both species. Detection information can be used to determine the appropriate level of sampling effort for larval fishes and may improve management and conservation decisions based on larval fish data.

Perspectives: Gene Expression in Fisheries Management

USGS Publications Warehouse

Nielsen, Jennifer L.; Pavey, Scott A.

2010-01-01

Functional genes and gene expression have been connected to physiological traits linked to effective production and broodstock selection in aquaculture, selective implications of commercial fish harvest, and adaptive changes reflected in non-commercial fish populations subject to human disturbance and climate change. Gene mapping using single nucleotide polymorphisms (SNPs) to identify functional genes, gene expression (analogue microarrays and real-time PCR), and digital sequencing technologies looking at RNA transcripts present new concepts and opportunities in support of effective and sustainable fisheries. Genomic tools have been rapidly growing in aquaculture research addressing aspects of fish health, toxicology, and early development. Genomic technologies linking effects in functional genes involved in growth, maturation and life history development have been tied to selection resulting from harvest practices. Incorporating new and ever-increasing knowledge of fish genomes is opening a different perspective on local adaptation that will prove invaluable in wild fish conservation and management. Conservation of fish stocks is rapidly incorporating research on critical adaptive responses directed at the effects of human disturbance and climate change through gene expression studies. Genomic studies of fish populations can be generally grouped into three broad categories: 1) evolutionary genomics and biodiversity; 2) adaptive physiological responses to a changing environment; and 3) adaptive behavioral genomics and life history diversity. We review current genomic research in fisheries focusing on those that use microarrays to explore differences in gene expression among phenotypes and within or across populations, information that is critically important to the conservation of fish and their relationship to humans.

Cultural and health implications of fish advisories in a Native American community

PubMed Central

Hoover, Elizabeth

2014-01-01

Introduction Fish advisories are issued in an effort to protect human health from exposure to contaminants, but Native American communities may suffer unintended health, social, and cultural consequences as a result of warnings against eating local fish. This paper focuses on the Mohawk community of Akwesasne, which lies downstream from a Superfund site, and explores how fish advisories have impacted fish consumption and health. Methods 65 Akwesasne community members were interviewed between March 2008 and April 2009. Interviews were semi-structured, lasted from 30–90 minutes and consisted of open-ended questions about the impacts of environmental contamination on the community. Detailed field notes were also maintained during extensive visits between 2007–2011. Interviews were transcribed, and these transcripts as well as the field notes were analyzed in NVivo 8.0. This research received approval from the Akwesasne Task Force on the Environment Research Advisory Committee, as well as the Brown University Institutional Review Board. Results Three-quarters of the 50 Akwesasne Mohawks interviewed have ceased or significantly curtailed their local fish consumption due to the issuance of fish advisories or witnessing or hearing about deformities on fish. Many of these respondents have turned to outside sources of fish, from other communities or from grocery stores. This change in fish consumption concerns many residents because cultural and social connections developed around fishing are being lost and because fish has been replaced with high-fat high-carb processed foods, which has led to other health complications. One-quarter of the 50 interviewees still eat local fish, but these are generally middle-aged or older residents; fish consumption no longer occurs in the multi-generational social context it once did. Conclusions Human health in Native American communities such as Akwesasne is intimately tied to the health of the environment. Fish advisories should not be used as an institutional control to protect humans from exposure to contaminants; if Akwesasne are to achieve optimal health, the contaminated environment has to be remediated to a level that supports clean, edible fish. PMID:25243106

The isolation, purification and amino-acid sequence of insulin from the teleost fish Cottus scorpius (daddy sculpin).

PubMed

Cutfield, J F; Cutfield, S M; Carne, A; Emdin, S O; Falkmer, S

1986-07-01

Insulin from the principal islets of the teleost fish, Cottus scorpius (daddy sculpin), has been isolated and sequenced. Purification involved acid/alcohol extraction, gel filtration, and reverse-phase high-performance liquid chromatography to yield nearly 1 mg pure insulin/g wet weight islet tissue. Biological potency was estimated as 40% compared to porcine insulin. The sculpin insulin crystallised in the absence of zinc ions although zinc is known to be present in the islets in significant amounts. Two other hormones, glucagon and pancreatic polypeptide, were copurified with the insulin, and an N-terminal sequence for pancreatic polypeptide was determined. The primary structure of sculpin insulin shows a number of sequence changes unique so far amongst teleost fish. These changes occur at A14 (Arg), A15 (Val), and B2 (Asp). The B chain contains 29 amino acids and there is no N-terminal extension as seen with several other fish. Presumably as a result of the amino acid substitutions, sculpin insulin does not readily form crystals containing zinc-insulin hexamers, despite the presence of the coordinating B10 His.

Update on HER2 testing for breast and upper gastrointestinal tract cancers.

PubMed

Ross, Jeffrey S

2011-06-01

With the regulatory approvals in Europe and the USA of trastuzumab-based anti-HER2 targeted therapy for upper gastrointestinal cancers in 2010, HER2 testing has now become universal for newly diagnosed cases of both breast cancer and adenocarcinomas of esophagus, stomach and gastroesophageal origin. In the 12 years or more since the approval of trastuzumab for breast cancer, general refinements in approaches to HER2 testing, including a greater understanding of the implications of preanalytic factors impacting the test results and the application of standardization of reporting of HER2 test results, have taken place. There has also been continuing development in breast cancer with the introduction of new HER2 tests, including non-FISH tests, dimerization assays, phosphorylated HER2 receptor tests, mRNA-based tests, HER2 gene sequencing tests and the application of HER2 testing to circulating tumor cells. Most recently, the introduction of HER2 testing for upper gastrointentinal malignancies has emphasized the need for performing and interpreting slide-based assays in a manner unique to these specimens and not to apply the breast cancer testing protocols to esophageal and gastric adenocarcinomas.

The behavioral response of prey fish to predators: the role of predator size.

PubMed

Tang, Zhong-Hua; Huang, Qing; Wu, Hui; Kuang, Lu; Fu, Shi-Jian

2017-01-01

Predation is one of the key factors governing patterns in natural systems, and adjustments of prey behaviors in response to a predator stimulus can have important ecological implications for wild fish. To investigate the effects of predators on the behavior of prey fish and to test whether the possible effects varied with predator size, black carp (Mylopharyngodon piceus) and snakehead (Channa argus) (a size-matched predator treatment with a similar body size to prey fish and a larger predator treatment with approximately 2.7 times of the body mass of prey fish) were selected to function as prey and predator, respectively. Their spontaneous activities were videorecorded in a central circular arena surrounded by a ring holding the stimulus fish. The distance between prey and predator fish was approximately 200% of the distance between two prey fish, which suggested that black carp can distinguish their conspecifics from heterospecifics and probably recognize the snakehead as a potential predator. The prey fish spent substantially less time moving and exhibited an overall shorter total distance of movement after the size-matched or large predator was introduced, which possibly occurred due to increased vigilance or efforts to reduce the possibility of detection by potential predators. However, there was no significant difference in either distance or spontaneous activities between two predator treatments. These findings suggested that (1) an anti-predator strategy in black carp might involve maintaining a safe distance, decreasing activity and possibly increased vigilance and that (2) the behaviors of prey response to predators were not influenced by their relative size difference.

Nitrification and Microbial Activity in Response to Wastewater Effluent in the Sacramento/San Joaquin River Delta

NASA Astrophysics Data System (ADS)

Challenor, T.; Damashek, J.; Tolar, B. B.; Francis, C.; Casciotti, K. L.

2016-12-01

Nitrification, the oxidation of ammonium (NH4+) to nitrate (NO3-) by a coterie of ammonia-oxidizing bacteria (AOB) and archaea (AOA), is a crucial step in removing nitrogen from marine ecosystems. The Sacramento/San Joaquin River delta receives ammonium-laden effluent from the Sacramento Regional Wastewater Treatment Plant (SRWTP) and nitrate from agriculture runoff. The system provides freshwater to irrigate the Central Valley and drinking water for many millions of people. In recent years, however, this environment has experienced ecological turmoil - the Pelagic Organism Decline (POD) refers to a die-out of fish and other species over the course of three decades. One explanation implicated excessive ammonium input, claiming it limited primary productivity and hurt pelagic fish down the line. A new hypothesis, however, posits that the ecosystem may soon face the opposite problem: over-productivity and hypoxia due to increased light availability and reduced turbidity. Studying the rate of nitrification and the makeup of the microbial community will further elucidate how nutrient loading has impacted this ecosystem. Nitrification rates were calculated from water samples collected in the Sacramento River starting at the SRWTP and moving downstream. Samples were spiked with 15N-labeled ammonium and incubated for 24 hours in triplicate. Four time-points were extracted and the "denitrifier" method was used to measure the isotopic ratio of N over time. DNA and RNA were extracted from filtered water at each site and PCR and qPCR assays were used targeting the amoA gene, which encodes the α-subunit of ammonia monooxygenase, responsible for oxidizing ammonium to nitrite (NO2-). Consistent with previous nitrification data, rates were highest in the lower river downstream of the SRWTP, where nitrate concentrations were correspondingly elevated. AOB predominated in the ammonia oxidizing community, and some clades were unique to this ecosystem. Nitrifying microbes provide an ecological service in reducing ammonium availability, a goal of wastewater regulation. Monitoring the activity of the Sacramento River's nitrifying community will be important for analyzing how this ecosystem responds to future changes that will impact populations of fish and people living in California.

Classification of a Hypervirulent Aeromonas hydrophila Pathotype Responsible for Epidemic Outbreaks in Warm-Water Fishes.

PubMed

Rasmussen-Ivey, Cody R; Hossain, Mohammad J; Odom, Sara E; Terhune, Jeffery S; Hemstreet, William G; Shoemaker, Craig A; Zhang, Dunhua; Xu, De-Hai; Griffin, Matt J; Liu, Yong-Jie; Figueras, Maria J; Santos, Scott R; Newton, Joseph C; Liles, Mark R

2016-01-01

Lineages of hypervirulent Aeromonas hydrophila (vAh) are the cause of persistent outbreaks of motile Aeromonas septicemia in warm-water fishes worldwide. Over the last decade, this virulent lineage of A. hydrophila has resulted in annual losses of millions of tons of farmed carp and catfish in the People's Republic of China and the United States (US). Multiple lines of evidence indicate US catfish and Asian carp isolates of A. hydrophila affiliated with sequence type 251 (ST251) share a recent common ancestor. To address the genomic context for the putative intercontinental transfer and subsequent geographic spread of this pathogen, we conducted a core genome phylogenetic analysis on 61 Aeromonas spp. genomes, of which 40 were affiliated with A. hydrophila , with 26 identified as epidemic strains. Phylogenetic analyses indicate all ST251 strains form a coherent lineage affiliated with A. hydrophila . Within this lineage, conserved genetic loci unique to A. hydrophila were identified, with some genes present in consistently higher copy numbers than in non-epidemic A. hydrophila isolates. In addition, results from analyses of representative ST251 isolates support the conclusion that multiple lineages are present within US vAh isolated from Mississippi, whereas vAh isolated from Alabama appear clonal. This is the first report of genomic heterogeneity within US vAh isolates, with some Mississippi isolates showing closer affiliation with the Asian grass carp isolate ZC1 than other vAh isolated in the US. To evaluate the biological significance of the identified heterogeneity, comparative disease challenges were conducted with representatives of different vAh genotypes. These studies revealed that isolate ZC1 yielded significantly lower mortality in channel catfish, relative to Alabama and Mississippi vAh isolates. Like other Asian vAh isolates, the ZC1 lineage contains all core genes for a complete type VI secretion system (T6SS). In contrast, more virulent US isolates retain only remnants of the T6SS ( clpB, hcp, vgrG , and vasH ) which may have functional implications. Collectively, these results characterize a hypervirulent A. hydrophila pathotype that affects farmed fish on multiple continents.

Biphasic modulation of neuro- and interrenal steroidogenesis in juvenile African sharptooth catfish (Clarias gariepinus) exposed to waterborne di-(2-ethylhexyl) phthalate.

PubMed

Arukwe, Augustine; Ibor, Oju R; Adeogun, Aina O

2017-12-01

Receptor (i.e. genomic) and non-receptor (or non-genomic) effects of endocrine toxicology have received limited or almost non-existent attention for tropical species and regions. In the present study, we have evaluated the effects of di-(2-ethylhexyl) phthalate (DEHP) on neuro- and interrenal steroidogenesis of the African catfish (Clarias gariepinus) using molecular, immunochemical and physiological approaches. Juvenile fish (mean weight and length: 5.6±0.6g and 8.2±1.2cm, respectively), were randomly distributed into ten 120L rectangular glass tanks containing 60L of dechlorinated tap water, at 50 fish per exposure group. The fish were exposed to environmentally relevant concentrations of DEHP, consisting of 0 (ethanol solvent control), 10, 100, 200, and 400μg DEHP/L water and performed in two replicates. Brain, liver and head kidney samples were collected at day 3, 7 and 14 after exposure, and analysed for star, p450scc, cyp19a1, cyp17, cyp11β-, 3β-, 17β- and 20β-hsd, and 17β-ohase mRNA expression using real-time PCR. The StAR, P450scc and CYP19 proteins were measured using immunoblotting method, while estradiol-17β (E2) and testosterone (T) were measured in liver homogenate using enzyme immunoassay (EIA). Our data showed a consistent and unique pattern of biphasic effect on star and steroidogenic enzyme genes with increases at low concentration (10μg/L) and thereafter, a concentration-dependent decrease in both the brain and head kidney, that paralleled the expression of StAR, P450scc and CYP19 proteins. Cellular E2 and T levels showed an apparent DEHP concentration-dependent increase at day 14 of exposure. The observed consistency in the current findings and in view of previous reports on contaminants-induced alterations in neuro- and interrenal steroidogenesis, the broader toxicological and endocrine disruptor implication of our data indicate potentials for overt reproductive, metabolic, physiological and general health consequences for the exposed organisms. Copyright © 2017 Elsevier Inc. All rights reserved.

Classification of a Hypervirulent Aeromonas hydrophila Pathotype Responsible for Epidemic Outbreaks in Warm-Water Fishes

PubMed Central

Rasmussen-Ivey, Cody R.; Hossain, Mohammad J.; Odom, Sara E.; Terhune, Jeffery S.; Hemstreet, William G.; Shoemaker, Craig A.; Zhang, Dunhua; Xu, De-Hai; Griffin, Matt J.; Liu, Yong-Jie; Figueras, Maria J.; Santos, Scott R.; Newton, Joseph C.; Liles, Mark R.

2016-01-01

Lineages of hypervirulent Aeromonas hydrophila (vAh) are the cause of persistent outbreaks of motile Aeromonas septicemia in warm-water fishes worldwide. Over the last decade, this virulent lineage of A. hydrophila has resulted in annual losses of millions of tons of farmed carp and catfish in the People's Republic of China and the United States (US). Multiple lines of evidence indicate US catfish and Asian carp isolates of A. hydrophila affiliated with sequence type 251 (ST251) share a recent common ancestor. To address the genomic context for the putative intercontinental transfer and subsequent geographic spread of this pathogen, we conducted a core genome phylogenetic analysis on 61 Aeromonas spp. genomes, of which 40 were affiliated with A. hydrophila, with 26 identified as epidemic strains. Phylogenetic analyses indicate all ST251 strains form a coherent lineage affiliated with A. hydrophila. Within this lineage, conserved genetic loci unique to A. hydrophila were identified, with some genes present in consistently higher copy numbers than in non-epidemic A. hydrophila isolates. In addition, results from analyses of representative ST251 isolates support the conclusion that multiple lineages are present within US vAh isolated from Mississippi, whereas vAh isolated from Alabama appear clonal. This is the first report of genomic heterogeneity within US vAh isolates, with some Mississippi isolates showing closer affiliation with the Asian grass carp isolate ZC1 than other vAh isolated in the US. To evaluate the biological significance of the identified heterogeneity, comparative disease challenges were conducted with representatives of different vAh genotypes. These studies revealed that isolate ZC1 yielded significantly lower mortality in channel catfish, relative to Alabama and Mississippi vAh isolates. Like other Asian vAh isolates, the ZC1 lineage contains all core genes for a complete type VI secretion system (T6SS). In contrast, more virulent US isolates retain only remnants of the T6SS (clpB, hcp, vgrG, and vasH) which may have functional implications. Collectively, these results characterize a hypervirulent A. hydrophila pathotype that affects farmed fish on multiple continents. PMID:27803692

Exceptional vertebrate biotas from the Triassic of China, and the expansion of marine ecosystems after the Permo-Triassic mass extinction

NASA Astrophysics Data System (ADS)

Benton, Michael J.; Zhang, Qiyue; Hu, Shixue; Chen, Zhong-Qiang; Wen, Wen; Liu, Jun; Huang, Jinyuan; Zhou, Changyong; Xie, Tao; Tong, Jinnan; Choo, Brian

2013-10-01

The Triassic was a time of turmoil, as life recovered from the most devastating of all mass extinctions, the Permo-Triassic event 252 million years ago. The Triassic marine rock succession of southwest China provides unique documentation of the recovery of marine life through a series of well dated, exceptionally preserved fossil assemblages in the Daye, Guanling, Zhuganpo, and Xiaowa formations. New work shows the richness of the faunas of fishes and reptiles, and that recovery of vertebrate faunas was delayed by harsh environmental conditions and then occurred rapidly in the Anisian. The key faunas of fishes and reptiles come from a limited area in eastern Yunnan and western Guizhou provinces, and these may be dated relative to shared stratigraphic units, and their palaeoenvironments reconstructed. The Luoping and Panxian biotas, both from the Guanling Formation, are dated as Anisian (Pelsonian) on the basis of conodonts and radiometric dates, the former being slightly older than the latter. The Xingyi biota is from the Zhuganpo Formation, and is Ladinian or early Carnian, while the Guanling biota is from the overlying Xiaowa Formation, dated as Carnian. The first three biotas include extensive benthos and burrowing in the sediments, and they were located in restricted basins close to shore. Further, even though the Luoping and Panxian biotas are of similar age, their faunas differ significantly, reflecting perhaps palaeogeographically isolated basins. Between the time of the Xingyi and Guanling biotas, there was a major transgression, and the Guanling biota is entirely different in character from the other three, being dominated by pelagic forms such as large floating crinoids attached to logs, very large ichthyosaurs and thalattosaurs, and pseudoplanktonic bivalves, with no benthos and no burrowing. Phylogenetic study of the fishes and marine reptiles shows apparently explosive diversification among 20 actinopterygian lineages very early in the Early Triassic, but a later expansion of marine reptile groups, in the late Olenekian and early Anisian. This offset in diversification patterns is matched by comparisons of feeding guild categories and body size data. New research tools will shed considerable light on the phylogenetic and ecological implications of recovery of mairne vertebrates in the Triassic.

Large-scale associations between macroalgal cover and grazer biomass on mid-depth reefs in the Caribbean

NASA Astrophysics Data System (ADS)

Williams, I.; Polunin, N.

2001-05-01

Since the 1970s, macroalgae have become considerably more abundant on many Caribbean reefs and overfishing of grazing fishes has been implicated as a contributory factor. We explored relationships between algal cover and grazers (biomass of herbivorous fishes and abundance of the sea-urchin Diadema antillarum) on mid-depth reefs (12-15 m) in 19 areas at seven locations in Jamaica, Barbados, Belize, Grand Cayman and Cuba, between April 1997 and April 1998. Diadema antillarum density was never >0.01 m-2, while herbivorous fish biomass (acanthurids and scarids ≥12 cm total length) varied from 2-5 g m-2 in Jamaica to 17.1 g m-2 in Barbados, and was strongly correlated, negatively with macroalgal cover and positively with 'cropped' substratum (sum of 'bare', turf and crustose-coralline substrata) cover. However, overfishing of herbivorous fishes alone cannot explain the widespread abundance of macroalgae, as even on lightly fished reefs, macroalgal cover was mostly >20%. Herbivorous fish populations on those reefs were apparently only able to maintain approximately 40-60% of reef substratum in cropped states, but due to low space-occupation by coral and other invertebrates, 70-90% of substratum was available to algae. The abundance of macroalgae on lightly fished reefs may therefore be a symptom of low coral cover in combination with the continuing absence of Diadema antillarum.

Effects of temperature on disease progression and swimming stamina in Ichthyophonus-infected rainbow trout, Oncorhynchus mykiss (Walbaum).

PubMed

Kocan, R; Hershberger, P; Sanders, G; Winton, J

2009-10-01

Rainbow trout, Oncorhynchus mykiss, were infected with Ichthyophonus sp. and held at 10 degrees C, 15 degrees C and 20 degrees C for 28 days to monitor mortality and disease progression. Infected fish demonstrated more rapid onset of disease, higher parasite load, more severe host tissue reaction and reduced mean-day-to-death at higher temperature. In a second experiment, Ichthyophonus-infected fish were reared at 15 degrees C for 16 weeks then subjected to forced swimming at 10 degrees C, 15 degrees C and 20 degrees C. Stamina improved significantly with increased temperature in uninfected fish; however, this was not observed for infected fish. The difference in performance between infected and uninfected fish became significant at 15 degrees C (P = 0.02) and highly significant at 20 degrees C (P = 0.005). These results have implications for changes in the ecology of fish diseases in the face of global warming and demonstrate the effects of higher temperature on the progression and severity of ichthyophoniasis as well as on swimming stamina, a critical fitness trait of salmonids. This study helps explain field observations showing the recent emergence of clinical ichthyophoniasis in Yukon River Chinook salmon later in their spawning migration when water temperatures were high, as well as the apparent failure of a substantial percentage of infected fish to successfully reach their natal spawning areas.

Effects of temperature on disease progression and swimming stamina in Ichthyophonus-infected rainbow trout, Oncorhynchus mykiss (Walbaum)

USGS Publications Warehouse

Kocan, R.; Hershberger, P.; Sanders, G.; Winton, J.

2009-01-01

Rainbow trout, Oncorhynchus mykiss, were infected with Ichthyophonus sp. and held at 10 ??C, 15 ??C and 20 ??C for 28 days to monitor mortality and disease progression. Infected fish demonstrated more rapid onset of disease, higher parasite load, more severe host tissue reaction and reduced mean-day-to-death at higher temperature. In a second experiment, Ichthyophonus-infected fish were reared at 15 ??C for 16 weeks then subjected to forced swimming at 10 ??C, 15 ??C and 20 ??C. Stamina improved significantly with increased temperature in uninfected fish; however, this was not observed for infected fish. The difference in performance between infected and uninfected fish became significant at 15 ??C (P = 0.02) and highly significant at 20 ??C (P = 0.005). These results have implications for changes in the ecology of fish diseases in the face of global warming and demonstrate the effects of higher temperature on the progression and severity of ichthyophoniasis as well as on swimming stamina, a critical fitness trait of salmonids. This study helps explain field observations showing the recent emergence of clinical ichthyophoniasis in Yukon River Chinook salmon later in their spawning migration when water temperatures were high, as well as the apparent failure of a substantial percentage of infected fish to successfully reach their natal spawning areas. ?? 2009 Blackwell Publishing Ltd.

Dispersal capacity predicts both population genetic structure and species richness in reef fishes.

PubMed

Riginos, Cynthia; Buckley, Yvonne M; Blomberg, Simon P; Treml, Eric A

2014-07-01

Dispersal is a fundamental species characteristic that should directly affect both rates of gene flow among spatially distributed populations and opportunities for speciation. Yet no single trait associated with dispersal has been demonstrated to affect both micro- and macroevolutionary patterns of diversity across a diverse biological assemblage. Here, we examine patterns of genetic differentiation and species richness in reef fishes, an assemblage of over 7,000 species comprising approximately one-third of the extant bony fishes and over one-tenth of living vertebrates. In reef fishes, dispersal occurs primarily during a planktonic larval stage. There are two major reproductive and parental investment syndromes among reef fishes, and the differences between them have implications for dispersal: (1) benthic guarding fishes lay negatively buoyant eggs, typically guarded by the male parent, and from these eggs hatch large, strongly swimming larvae; in contrast, (2) pelagic spawning fishes release small floating eggs directly into the water column, which drift unprotected before small weakly swimming larvae hatch. Using phylogenetic comparative methods, we show that benthic guarders have significantly greater population structure than pelagic spawners and additionally that taxonomic families of benthic guarders are more species rich than families of pelagic spawners. Our findings provide a compelling case for the continuity between micro- and macroevolutionary processes of biological diversification and underscore the importance of dispersal-related traits in influencing the mode and tempo of evolution.

Kounis syndrome following canned tuna fish ingestion.

PubMed

De Gennaro, Luisa; Brunetti, Natale Daniele; Locuratolo, Nicola; Ruggiero, Massimo; Resta, Manuela; Diaferia, Giuseppe; Rana, Michele; Caldarola, Pasquale

2017-04-01

Kounis syndrome (KS) is a complex of cardiovascular symptoms and signs following either allergy or hypersensitivity and anaphylactic or anaphylactoid insults. We report the case of 57-year-old man, with hypertension and history of allergy, referred for facial rash and palpitations appeared after consumption of canned tuna fish. Suddenly, the patient collapsed: electrocardiogram showed ST-elevation in inferior leads. The patient was transferred from the spoke emergency room for coronary angio, which did not show any sign of coronary atherosclerosis. A transient coronary spasm was therefore hypothesized and the final diagnosis was KS. To the best of our knowledge, this is one of the first cases of KS following the ingestion of tuna fish. KS secondary to food allergy has also been reported, and shellfish ingestion has been considered as one of the most active KS inducer foods. Canned tuna fish too is well known as an allergy inducer. Tuna fish allergy should be considered, however, within the context of scombroid food poisoning, also called histamine fish poisoning. Fish with high levels of free histidine, the enzyme substrate converted to histamine by bacterial histidine decarboxylase, are those most often implicated in scombroid poisoning. Inflammatory mediators such as histamine constitute the pathophysiologic basis of Kounis hypersensitivity-associated acute coronary syndrome. Patients with coronary risk factors, allergic reaction after food ingestion, and suspected scombroid poisoning should be therefore carefully monitored for a prompt diagnosis of possible coronary complications.

Environmental risk assessment of alkylphenols from offshore produced water on fish reproduction.

PubMed

Beyer, Jonny; Myhre, Lars Petter; Sundt, Rolf C; Meier, Sonnich; Tollefsen, Knut-Erik; Vabø, Rune; Klungsøyr, Jarle; Sanni, Steinar

2012-04-01

Concern has been raised over whether environmental release of alkylphenols (AP) in produced water (PW) discharges from the offshore oil industry could impose a risk to the reproduction of fish stocks in the North Sea. An environmental risk assessment (ERA) was performed to determine if environmental exposure to PW APs in North Sea fish populations is likely to be high enough to give effects on reproduction endpoints. The DREAM (Dose related Risk and Effect Assessment Model) software was used in the study and the inputs to the ERA model included PW discharge data, fate information of PW plumes, fish distribution information, as well as uptake and elimination information of PW APs. Toxicodynamic data from effect studies with Atlantic cod (Gadus morhua) exposed to APs were used to establish a conservative environmental risk threshold value for AP concentration in seawater. By using the DREAM software to 1) identify the areas of highest potential risk and 2) integrate fish movement and uptake/elimination rates of APs for the chosen areas we found that the environmental exposure of fish to APs from PW is most likely too low to affect reproduction in wild populations of fish in the North Sea. The implications related to risk management of offshore PW and uncertainties in the risk assessment performed are discussed. Copyright © 2011 Elsevier Ltd. All rights reserved.

Six-Degree-of-Freedom Sensor Fish Design and Instrumentation

PubMed Central

Deng, Zhiqun; Carlson, Thomas J.; Duncan, Joanne P.; Richmond, Marshall C.

2007-01-01

Fish passing through dams may be injured or killed despite advances in turbine design, project operations and other fish bypass systems. The six-degree-of-freedom (6DOF) Sensor Fish device is an autonomous sensor package that characterizes the physical conditions and physical stresses to which fish are exposed when they pass through complex hydraulic environments. It has been used to identify the locations and operations where conditions are severe enough to injure or kill fish. During the design process, a set of governing equations of motion for the Sensor Fish was derived and simulated to understand the design implications of instrument selection and placement within the body of the device. The Sensor Fish package includes three rotation sensors, three acceleration sensors, a pressure sensor, and a temperature sensor with a sampling frequency of 2,000 Hz. Its housing is constructed of clear polycarbonate plastic. It is 24.5 mm in diameter and 90 mm in length and weighs about 43 g, similar to the size and density of a yearling salmon smolt. The accuracy of the pressure sensor was determined to be within 0.2 psi. In laboratory acceptance tests, the relative errors of both the linear acceleration and angular velocity measurements were determined to be less than 5%. An exposure is defined as a significant event when the acceleration reaches predefined thresholds. Based on the different characteristic of acceleration and rotation velocities, the exposure event is categorized as either a collision between the Sensor Fish and a solid structure or shear caused by turbulence. Since its development in 2005, the 6DOF Sensor Fish has been deployed successfully at many major dams in the United States. PMID:28903301

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

PubMed

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.

Understanding spearfishing in a coral reef fishery: Fishers’ opportunities, constraints, and decision-making

PubMed Central

Pavlowich, Tyler; Kapuscinski, Anne R.

2017-01-01

Social and ecological systems come together during the act of fishing. However, we often lack a deep understanding of the fishing process, despite its importance for understanding and managing fisheries. A quantitative, mechanistic understanding of the opportunities fishers encounter, the constraints they face, and how they make decisions within the context of opportunities and constraints will enhance the design of fisheries management strategies to meet linked ecological and social objectives and will improve scientific capacity to predict impacts of different strategies. We examined the case of spearfishing in a Caribbean coral reef fishery. We mounted cameras on fishers’ spearguns to observe the fish they encountered, what limited their ability to catch fish, and how they made decisions about which fish to target. We observed spearfishers who dove with and without the assistance of compressed air, and compared the fishing process of each method using content analysis of videos and decision models of fishers’ targeting selections. Compressor divers encountered more fish, took less time to catch each fish, and had a higher rate of successful pursuits. We also analyzed differences among taxa in this multispecies fishery, because some taxa are known to be ecologically or economically more valuable than others. Parrotfish are ecologically indispensable for healthy coral reefs, and they were encountered and captured more frequently than any other taxon. Fishers made decisions about which fish to target based on a fish’s market value, proximity to the fisher, and taxon. The information uncovered on fishers’ opportunities, constraints, and decision making has implications for managing this fishery and others. Moreover, it demonstrates the value of pursuing an improved understanding of the fishing process from the perspective of the fishers. PMID:28750077

Fish product mislabelling: failings of traceability in the production chain and implications for illegal, unreported and unregulated (IUU) fishing.

PubMed

Helyar, Sarah J; Lloyd, Hywel Ap D; de Bruyn, Mark; Leake, Jonathan; Bennett, Niall; Carvalho, Gary R

2014-01-01

Increasing consumer demand for seafood, combined with concern over the health of our oceans, has led to many initiatives aimed at tackling destructive fishing practices and promoting the sustainability of fisheries. An important global threat to sustainable fisheries is Illegal, Unreported and Unregulated (IUU) fishing, and there is now an increased emphasis on the use of trade measures to prevent IUU-sourced fish and fish products from entering the international market. Initiatives encompass new legislation in the European Union requiring the inclusion of species names on catch labels throughout the distribution chain. Such certification measures do not, however, guarantee accuracy of species designation. Using two DNA-based methods to compare species descriptions with molecular ID, we examined 386 samples of white fish, or products labelled as primarily containing white fish, from major UK supermarket chains. Species specific real-time PCR probes were used for cod (Gadus morhua) and haddock (Melanogrammus aeglefinus) to provide a highly sensitive and species-specific test for the major species of white fish sold in the UK. Additionally, fish-specific primers were used to sequence the forensically validated barcoding gene, mitochondrial cytochrome oxidase I (COI). Overall levels of congruence between product label and genetic species identification were high, with 94.34% of samples correctly labelled, though a significant proportion in terms of potential volume, were mislabelled. Substitution was usually for a cheaper alternative and, in one case, extended to a tropical species. To our knowledge, this is the first published study encompassing a large-scale assessment of UK retailers, and if representative, indicates a potentially significant incidence of incorrect product designation.

The hypothalamic-pituitary-thyroid (HPT) axis in fish and its role in fish development and reproduction.

PubMed

Blanton, Michael L; Specker, Jennifer L

2007-01-01

Bony fishes represent the largest vertebrate class and are a very diverse animal group. This chapter provides a thorough review of the available scientific literature on the thyroid system in these important vertebrate animals. The molecular components of the hypothalamic-pituitary-thyroid (HPT) axis in this group correspond closely to those of mammals. The thyroid tissue in the fishes is organized as diffuse follicles, with a few exceptions, rather than as an encapsulated gland as is found in most other vertebrate species. The features of this diffuse tissue in fishes are reviewed with an emphasis on feedback relationships within the HPT axis, the molecular biology of the thyroid system in fishes, and comparisons versus the thyroid systems of other vertebrate taxa. A review of the role of thyroid hormone in fish development and reproduction is included. Available information about the HPT axis in fishes is quite detailed for some species and rather limited or absent in others. This review focuses on species that have been intensively studied for their value as laboratory models in assays to investigate disruption in normal function of the thyroid system. In addition, in vitro and in vivo assay methods for screening chemicals for their potential to interfere with the thyroid system are reviewed. It is concluded that there are currently no in vitro or in vivo assays in fish species that are sufficiently developed to warrant recommendation for use to efficiently screen chemicals for thyroid disruption. Methods are available that can be used to measure thyroid hormones, although our ability to interpret the causes and implications of potential alterations in T4 or T3 levels in fishes is nonetheless limited without further research.

Incomplete digestion of codfish represents a risk factor for anaphylaxis in patients with allergy

PubMed Central

Untersmayr, Eva; Vestergaard, Helle; Malling, Hans-Jørgen; Jensen, Louise Bjerremann; Platzer, Michael H.; Boltz-Nitulescu, George; Scheiner, Otto; Skov, Per Stahl; Jensen-Jarolim, Erika; Poulsen, Lars K.

2010-01-01

Background Fish represents one of the most important allergenic foods causing severe allergic reactions. Nevertheless, it has been shown that gastric digestion significantly reduces its allergenic capacity. Objective In this study, we assessed the absorption kinetics of fish proteins and investigated the clinical reactivity of patients with fish allergy to codfish digested at physiological or elevated gastric pH. Methods Healthy individuals were openly challenged with codfish and blood samples were evaluated by histamine release for absorbed fish allergens. Patients with allergy were recruited on the basis of previously diagnosed codfish allergy. Fish extracts were digested with gastric enzymes at pH 2.0 and 3.0 and used for histamine release, skin prick tests, and titrated double-blind placebo-controlled food challenges. Results Ingestion experiments in subjects without allergy revealed absorption of biologically active fish allergens only 10 minutes after ingestion with maximal serum levels after 1 to 2 hours. Incubation of fish proteins with digestive enzymes at pH 2.0 resulted in a fragmentation of the proteins leading to a reduced biological activity evidenced by a significantly smaller wheal reaction and reduced histamine release. Fish digested at pH 3.0 revealed comparable reactivity patterns as undigested extracts. Moreover, these test materials triggered reactions at 10-fold to 30-fold lower cumulated challenge doses in patients with allergy. Conclusion Our data indicate the paramount importance of gastric digestion for fish allergens because the quantitatively significant absorption and elicitation of symptoms seemed to take place in the intestine. Clinical implications Hindered digestion puts patients with fish allergy at risk to develop severe allergic reactions at minute amounts of allergens. PMID:17215033

Might "Unique" Factors Be "Common"? On the Possibility of Indeterminate Common-Unique Covariances

ERIC Educational Resources Information Center

Grayson, Dave

2006-01-01

The present paper shows that the usual factor analytic structured data dispersion matrix lambda psi lambda' + delta can readily arise from a set of scores y = lambda eta + epsilon, shere the "common" (eta) and "unique" (epsilon) factors have nonzero covariance: gamma = Cov epsilon,eta) is not equal to 0. Implications of this finding are discussed…

Water-level fluctuations influence sediment porewater chemistry and methylmercury production in a flood-control reservoir.

EPA Science Inventory

Reservoirs typically have elevated fish mercury (Hg) levels compared to natural lakes and rivers. A unique feature of reservoirs is water-level management which can result in sediment exposure to the air. The objective of this study is to identify how reservoir water-level fluct...