Science.gov

Sample records for lepomis gibbosus centrarchidae

  1. Myxobolus lepomis n. sp. (Cnidaria: Myxobolidae), a gill myxozoan infecting Lepomis marginatus Holbrook and Lepomis miniatus Jordan (Perciformes: Centrarchidae), in the Big Thicket National Preserve, Texas, USA.

    PubMed

    Rosser, Thomas G; Baumgartner, Wes A; Barger, Michael A; Griffin, Matt J

    2017-05-01

    A parasitological survey of freshwater fishes in the Big Thicket National Preserve in southeast Texas revealed myxozoan infections in two species of sunfish, Lepomis marginatus Holbrook and Lepomis miniatus Jordan (Perciformes: Centrarchidae). Pseudocysts were elongate-oval, 988 × 485 µm (ex L. marginatus) and 800 × 606 µm (ex L. miniatus) and demonstrated a predilection to the edge of the primary gill lamellae. Myxospores consistent with the genus Myxobolus were oblong, 16.8-21.3 (19.0 ± 0.9) µm long, 7.0-8.8 (7.9 ± 0.5) µm wide and 5.3-6.1 (5.8 ± 0.3) µm thick (ex L. marginatus) and 17.2-20.3 (18.8 ± 0.7) µm long, 7.5-9.9 (8.7 ± 0.6) µm wide, and 6.8-7.2 (7.0 ± 0.2) µm thick (ex L. miniatus); with 2 pyriform polar capsules 8.3-9.8 (9.0 ± 0.5) µm long, 2.2-2.7 (2.5 ± 0.2) µm wide (ex L. marginatus) and 9.2-10.5 (10.0 ± 0.4) µm long, 2.2-3.0 (2.8 ± 0.2) µm wide (ex L. miniatus). Statistically, the measurements of spore body width, polar capsule length, and polar capsule width were significantly different between myxospores from L. marginatus and L. miniatus. However, intraspecific genetic variability between isolates at the 18S rRNA gene was negligible, with < 0.8% variability across > 2,000 bp of sequence. The isolates shared no significant sequence similarity with any myxozoan deposited in the GenBank nucleotide database. Phylogenetic analysis inferred from the 18S rRNA gene from both L. marginatus and L. miniatus placed the isolates within a clade of myxozoan parasites of perciform fishes. Based on shared tissue and host family tropism, overlapping morphological characters and high degrees of sequence conservation at the 18S rRNA gene, we propose these isolates as morphologically distinct, genetically conspecific representatives of M. lepomis n. sp. from the gills of L. marginatus and L. miniatus in the Big Thicket National Preserve in Texas, USA.

  2. UNDULATORY SWIMMING: HOW TRAVELING WAVES ARE PRODUCED AND MODULATED IN SUNFISH (LEPOMIS GIBBOSUS)

    PubMed

    Long; Mchenry; Boetticher

    1994-07-01

    We have developed an experimental procedure in which the in situ locomotor muscles of dead fishes can be electrically stimulated to generate swimming motions. This procedure gives the experimenter control of muscle activation and the mechanical properties of the body. Using pumpkinseed sunfish, Lepomis gibbosus, we investigated the mechanics of undulatory swimming by comparing the swimming kinematics of live sunfish with the kinematics of dead sunfish made to swim using electrical stimulation. In electrically stimulated sunfish, undulatory waves can be produced by alternating left­right contractions of either all the axial muscle or just the precaudal axial muscle. As judged by changes in swimming speed, most of the locomotor power is generated precaudally and transmitted to the caudal fin by way of the skin and axial skeleton. The form of the traveling undulatory wave ­ as measured by tail-beat amplitude, propulsive wavelength and maximal caudal curvature ­ can be modulated by experimental control of the body's passive stiffness, which is a property of the skin, connective tissue and axial skeleton.

  3. Interspecific Aggressive Behaviour of Invasive Pumpkinseed Lepomis gibbosus in Iberian Fresh Waters

    PubMed Central

    Almeida, David; Merino-Aguirre, Raquel; Vilizzi, Lorenzo; Copp, Gordon H.

    2014-01-01

    Pumpkinseed Lepomis gibbosus (L.) are successful invaders in Europe, where this species exerts multiple ecological effects, mainly through trophic interactions. Behavioural interference represents a potential impact for native fauna and this is of particular conservation concern in the Iberian Peninsula because of the highly valuable endemic fauna inhabiting streams of this region. However, aggressive interactions have not previously been examined under natural conditions in Iberian fresh waters. To address this gap in knowledge, the aim of the present study was to assess the effect of pumpkinseed aggression on endemic fauna of an Iberian stream, the River Bullaque (central Spain). In September 2009, we analysed the aggression and environmental contexts of these behavioural interactions by snorkelling: aggressor size, aggression type, shoal size, previous activity to aggression, recipient species, response to aggression, microhabitat structure and prey availability. Small pumpkinseed displayed more threat and fewer pursuit behaviours relative to medium and large individuals, reflecting an ontogenetic behavioural shift from low to high aggression intensity. Small aggressors came from large shoals, with bottom feeding being the most frequently observed activity prior to an aggressive interaction; whereas large pumpkinseed were less gregarious and they were mostly ambulating within the water column prior to aggression. Recipient species of aggression included non-native crayfish and fishes, and more importantly, endemic fishes and frogs. Retreat was the most common response to aggression, irrespective of aggressor size. Small pumpkinseed displayed aggressive behaviours over coarse substrata containing elevated macrobenthos biomass; whereas aggression by large individuals was observed in deeper waters. These findings suggest that small and large pumpkinseed exert a high impact on other stream residents through aggression in competition for food and territory defence

  4. Interspecific aggressive behaviour of invasive pumpkinseed Lepomis gibbosus in Iberian fresh waters.

    PubMed

    Almeida, David; Merino-Aguirre, Raquel; Vilizzi, Lorenzo; Copp, Gordon H

    2014-01-01

    Pumpkinseed Lepomis gibbosus (L.) are successful invaders in Europe, where this species exerts multiple ecological effects, mainly through trophic interactions. Behavioural interference represents a potential impact for native fauna and this is of particular conservation concern in the Iberian Peninsula because of the highly valuable endemic fauna inhabiting streams of this region. However, aggressive interactions have not previously been examined under natural conditions in Iberian fresh waters. To address this gap in knowledge, the aim of the present study was to assess the effect of pumpkinseed aggression on endemic fauna of an Iberian stream, the River Bullaque (central Spain). In September 2009, we analysed the aggression and environmental contexts of these behavioural interactions by snorkelling: aggressor size, aggression type, shoal size, previous activity to aggression, recipient species, response to aggression, microhabitat structure and prey availability. Small pumpkinseed displayed more threat and fewer pursuit behaviours relative to medium and large individuals, reflecting an ontogenetic behavioural shift from low to high aggression intensity. Small aggressors came from large shoals, with bottom feeding being the most frequently observed activity prior to an aggressive interaction; whereas large pumpkinseed were less gregarious and they were mostly ambulating within the water column prior to aggression. Recipient species of aggression included non-native crayfish and fishes, and more importantly, endemic fishes and frogs. Retreat was the most common response to aggression, irrespective of aggressor size. Small pumpkinseed displayed aggressive behaviours over coarse substrata containing elevated macrobenthos biomass; whereas aggression by large individuals was observed in deeper waters. These findings suggest that small and large pumpkinseed exert a high impact on other stream residents through aggression in competition for food and territory defence

  5. Altered trophic pathway and parasitism in a native predator (Lepomis gibbosus) feeding on introduced prey (Dreissena polymorpha).

    PubMed

    Locke, Sean A; Bulté, Grégory; Marcogliese, David J; Forbes, Mark R

    2014-05-01

    Populations of invasive species tend to have fewer parasites in their introduced ranges than in their native ranges and are also thought to have fewer parasites than native prey. This 'release' from parasites has unstudied implications for native predators feeding on exotic prey. In particular, shifts from native to exotic prey should reduce levels of trophically transmitted parasites. We tested this hypothesis in native populations of pumpkinseed sunfish (Lepomis gibbosus) in Lake Opinicon, where fish stomach contents were studied intensively in the 1970s, prior to the appearance of exotic zebra mussels (Dreissena polymorpha) in the mid-1990s. Zebra mussels were common in stomachs of present-day pumpkinseeds, and stable isotopes of carbon and nitrogen confirmed their importance in long-term diets. Because historical parasite data were not available in Lake Opinicon, we also surveyed stomach contents and parasites in pumpkinseed in both Lake Opinicon and an ecologically similar, neighboring lake where zebra mussels were absent. Stomach contents of pumpkinseed in the companion lake did not differ from those of pre-invasion fish from Lake Opinicon. The companion lake, therefore, served as a surrogate "pre-invasion" reference to assess effects of zebra mussel consumption on parasites in pumpkinseed. Trophically transmitted parasites were less species-rich and abundant in Lake Opinicon, where fish fed on zebra mussels, although factors other than zebra mussel consumption may contribute to these differences. Predation on zebra mussels has clearly contributed to a novel trophic coupling between littoral and pelagic food webs in Lake Opinicon.

  6. Effects of river flows on growth of redbreast sunfish Lepomis auritus (Centrarchidae) in Georgia rivers.

    PubMed

    Sammons, S M; Maceina, M J

    2009-05-01

    Effects of river discharge on growth of redbreast sunfish Lepomis auritus were investigated in nine rivers in Georgia, U.S.A. Fish were aged and annular total length increments (L(Tinc)) estimated from measurements from sectioned sagittal otoliths using the generalized regression model that held for the effects of decreasing L(Tinc) from annual age (X): L(Tinc)=b(o)-b(1)(X) +/-b(i)(D), where b(o), b(1) and b(i) were the regression coefficients for the intercept and slopes and D, discharge, was either a single or multiple measurements of annular or seasonal flow volume or variation in flow volume. For eight of nine rivers, higher or greater variation in flows from April to June was associated with greater L. auritus growth; in the last river, higher flows from January to March were associated with greater fish growth. Across all rivers, L. auritus growth increments were 22, 45 and 36% greater in a wet year v. a dry year at ages 1, 2 and 3 years, respectively. Based on the results of this study, increasing water withdrawals by an additional 30% in five Georgia rivers would reduce the predicted number of L. auritus recruiting to 203 mm (angler preferred size) by 19-62%.

  7. Seasonal gonadal development and age-related maturity patterns of introduced pumpkinseed (Lepomis gibbosus Linnaeus, 1758) in a heated thermal reservoir and an adjacent river reach.

    PubMed

    Valente, E; Masson, G; Maul, A; Fox, M G; Meyer, A; Pihan, J C

    2016-05-01

    Testis and ovarian maturation status, maturity profile and gonado-somatic index (GSI) were assessed in pumpkinseed (Lepomis gibbosus) collected from Mirgenbach, a cooling-water reservoir associated with a nuclear power plant, and from the River Moselle 7km downstream of the reservoir's thermal outflow. Histological investigation indicated that in both sexes, gonadal development of pumpkinseed in the heated reservoir was more advanced than in the cooler Moselle River throughout the breeding season. The histological maturity profile of reservoir males ranked by the advancement of sperm cells was highly correlated with its GSI (rs=0.73, P<0.001). GSI of females in the reservoir increased with the stage at maturity, but GSI was not significantly correlated with total length, age or growth rate of the individual. All sampled individuals of both sexes were mature at age 1 in the heated reservoir, whereas 48% of age 1 males and 57% of age 1 females were not mature in the river. GSI patterns suggest that males in the reservoir adopted one of two reproductive strategies (nesters or cuckolders), whereas no small males with large enough testes to be considered cuckolders were apparent in the river. The warm thermal regime of Mirgenbach Reservoir led to precocial maturity, early season reproduction, and the greater prevalence of apparent cuckolder males than would normally occur in this climatic zone. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. Effect of submersed aquatic macrophytes on resource partitioning in yearling rock bass (Ambloplites rupestris) and pumpkinseeds (Lepomis gibbosus) in Lake St. Clair

    USGS Publications Warehouse

    French, John R. P.

    1988-01-01

    Yearling rock bass (Ambloplites rupestris), pumpkinseeds (Lepomis gibbosus), macroinvertebrates, and submersed aquatic plants were sampled at 2- or 3-week intervals from June to October 1979 in a shallow, heavily vegetated embayment in Lake St. Clair to determine whether seasonal changes in plant canopy and plant taxonomic composition affected resource partitioning in these two fish species. In both species, numbers of prey and gut volumes increased with increasing plant canopy until the plant canopy reached a seasonal maximum in mid-summer. Rock bass consumed fewer, larger prey than pumpkinseeds while large Caenidae-Trichoptera-Coenagrionidae, the prey group most preferred by rock bass, was available. Pumpkinseeds ate smaller amphipods, gastropods, and chironomid-lepidopterans that were more abundant numerically than Caenidae-Trichoptera-Coenagrionidae. After mid-summer, the plant canopy declined slowly to one-half of the maximum value, but built-up densities ofHyalella azteca, gastropods, and chironomid-lepidopterans kept availability of prey high throughout late summer. Rock bass shifted to Gammarus, gastropods, and chironomid-lepidopterans as large Caenidae-Trichoptera-Coenagrionidae became scarce. Pumpkinseeds ate more prey in the late season and displayed no prey preference. Their gut volumes peaked in September. Apparently, increasing combined canopy of bushy plants and Heteranthera dubia hindered the foraging of rock bass more than that of pumpkinseeds and caused resource partitioning in the two species.

  9. Alterations in gills of Lepomis gibbosus, after acute exposure to several xenobiotics (pesticide, detergent and pharmaceuticals): morphometric and biochemical evaluation.

    PubMed

    Rodrigues, Sara; Correia, Alberto T; Antunes, Sara C; Nunes, Bruno

    2015-04-01

    In recent decades, scientific research about the effects of anthropogenic xenobiotics on non-target organisms has increased. Among the likely effects, some studies reported the evaluation of biochemical and morphological changes in specific tissues or organs of fishes, such as gills, which are key organs for the direct action of pollutants in the aquatic environment. This work intended to assess biochemical [oxidative stress/phase II conjugation isoenzymes glutathione S-transferase (GSTs)] and morphological [secondary lamellar length (SLL), secondary lamellar width (SLW), interlamellar distance (ID), basal epithelial thickness (BET) and proportion of the secondary lamellae available for gas exchange (PAGE)] changes in gills, after acute exposure to the pesticide chlorfenvinphos, the detergent sodium dodecylsulphate (SDS) and to the anticholinesterasic pharmaceuticals (neostigmine and pyridostigmine). Our results point to a significant, eventually hormetic, effect in the activity of GSTs following exposure to chlorfenvinphos that significantly increased the activity of GSTs at concentration of 0.2 mg/L. The activity of GSTs increased significantly after exposure to 100 mg/L of neostigmine. Considering the morphometric analysis of the gills, the data obtained showed that chlorfenvinphos exerted mainly minor architectural alterations in gills, with the exception of the highest tested concentration of chlorfenvinphos that produced also a slight decrease of the PAGE. The overall conclusions point to a null or negligible toxicity of the selected toxicants towards L. gibbosus, which may be reverted if exposure is withdrawn.

  10. Substrate choice of territorial male topeka shiners (notropis topeka) in the absence of sunfish (lepomis sp.)

    USGS Publications Warehouse

    Witte, C.C.; Wildhaber, M.L.; Arab, A.; Noltie, Douglas B.

    2009-01-01

    Topeka shiners (Notropis topeka), an endangered minnow species, typically spawn on or around breeding Lepomis sunfish (Centrarchidae) nests. Why spawning Topeka shiners are attracted to these nests is unclear, but having the nesting sunfish provide shiner eggs with improved aeration, a lessening of siltation, and protection from egg predators are possibilities. We tested the substrate utilisation of Topeka shiners in outdoor tanks in the absence of sunfish to determine the shiner's fundamental choice. Shiners were provided with substrate patches of cleaned sand, small gravel, large gravel, and small cobble, and the bare floor of the tank. The substrate above which a male shiner established his territory was used as evidence of choice. A statistically significant choice for sand substrates was demonstrated. This fundamental choice might influence which sunfish nests Topeka shiners use, given that nest substrate characteristics differ both between sunfish species and within species by spawning site location. ?? 2009 John Wiley & Sons A/S.

  11. Hybridization and Introgression among Species of Sunfish (Lepomis): Analysis by Mitochondrial DNA and Allozyme Markers

    PubMed Central

    Avise, John C.; Saunders, Nancy C.

    1984-01-01

    We explore the potential of mitochondrial DNA (mtDNA) analysis, alone and in conjunction with allozymes, to study low-frequency hybridization and introgression phenomena in natural populations. MtDNAs from small samples of nine species of sunfish (Lepomis, Centrarchidae) were purified and digested with each of 13 informative restriction enzymes. Digestion profiles for all species were highly distinct: estimates of overall fragment homology between pairs of species ranged from 0–36%. Allozymes encoded by nine nuclear genes also showed large frequency differences among species and together with mtDNA provided many genetic markers for hybrid identification. A genetic analysis of 277 sunfish from two locations in north Georgia revealed the following: (1) a low frequency of interspecific hybrids, all of which appeared to be F1's; (2) the involvement of five sympatric Lepomis species in the production of these hybrids; (3) no evidence for introgression between species in our study locales (although for rare hybridization, most later-generation backcrosses would not be reliably distinguished from parentals); (4) a tendency for hybridizations to take place preferentially between parental species differing greatly in abundance; (5) a tendency for the rare species in a hybrid cross to provide the female parent. Our data suggest that absence of conspecific pairing partners and mating stimuli for females of rarer species may be important factors in increasing the likelihood of interspecific hybridization. The maternal inheritance of mtDNA offers at least two novel advantages for hybridization analysis: (1) an opportunity to determine direction in hybrid crosses; and (2) due to the linkage among mtDNA markers, an increased potential to distinguish effects of introgression from symplesiomorphy or character convergence. PMID:6090268

  12. [Phylogeography and phenotypic diversity of the pumpkinseed Sunfish Lepomis gibbosus (Linnaeus, 1758) of the Northern Black Sea Coast].

    PubMed

    Slynko, E E; Novitsky, R A; Bangs, M R; Douglas, M R; Douglas, M E; Khrystenko, D S; Kasyanov, A N; Slynko, Yu V

    2015-02-01

    This paper studies the origin and the genetic and morphological diversity of the pumpkinseed sunfish, a North American invader that is actively expanding its range in the Northern Black Sea Coast. Based on an analysis of variability of the nucleotide sequence of the mtDNA cyt b locus, it was found that all populations of the Northern Black Sea Coast (basins of Dnieper, Dniester, and Danube rivers) are represented by one haplotype. Intraspecific variability is absent. Phylogeographic analysis revealed that the most related haplotype is in a population of pumpkinseed sunfish from New Germany Lake in the Potomac Riverbasin (Maryland, United States), which makes it possible to consider it a parent of the investigated populations. Morphological variation oin countable traits was highly homogeneous. Significant differentiation of a sample from the population of the Dnieper Reservoir from the populations of the Danube and Dniester was found for plastic traits of both the body and cranium. Analysis of the trajectories of development showed that the Dnieper is inhabited by a "pelagic" morpho-ecological form of pumpkinseed sunfish, while the Dniester and Danube is inhabited by a "littoral" form. It is suggested that the success of the settlement of this North American species in the Northern Black Sea Coast does not depend on the origin or the level of its genetic diversity but is instead likely to be ensured by the realization of its available discrete morpho-ecological variability.

  13. How Will Climate Warming Affect Non-Native Pumpkinseed Lepomis gibbosus Populations in the U.K.?

    PubMed Central

    Zięba, Grzegorz; Fox, Michael G.; Copp, Gordon H.

    2015-01-01

    Of the non-native fishes introduced to the U.K., the pumpkinseed is one of six species predicted to benefit from the forecasted climate warming conditions. To demonstrate the potential response of adults and their progeny to a water temperature increase, investigations of parental pumpkinseed acclimatization, reproduction and YOY over-wintering were carried out in outdoor experimental ponds under ambient and elevated water temperature regimes. No temperature effects were observed on either adult survivorship and growth, and none of the assessed reproductive activity variables (total spawning time, spawning season length, number of spawning bouts) appeared to be responsible for the large differences observed in progeny number and biomass. However, it was demonstrated in a previous study [Zięba G. et al., 2010] that adults in the heated ponds began spawning earlier than those of the ambient ponds. Ambient ponds produced 2.8× more progeny than the heated ponds, but these progeny were significantly smaller, probably due to their late hatching date, and subsequently suffered very high mortality over the first winter. Pumpkinseed in the U.K. will clearly benefit from climate warming through earlier seasonal reproduction, resulting in larger progeny going into winter, and as a result, higher over-winter survivorship would be expected relative to that which occurs under the present climatic regime. PMID:26302021

  14. Novel potassium channel blocker venom peptides from Mesobuthus gibbosus (Scorpiones: Buthidae).

    PubMed

    Diego-García, Elia; Peigneur, Steve; Debaveye, Sarah; Gheldof, Eveline; Tytgat, Jan; Caliskan, Figen

    2013-01-01

    In the present study, we report for the first time, the molecular, biochemical and electrophysiological characterization of the components present in the soluble venom from Mesobuthus gibbosus (Brullé, 1832). According to the epidemiological and clinical situation of scorpion envenomation cases M. gibbosus scorpion is one of the most important health-threatening species of Turkey. Despite the medical importance reported for M. gibbosus, there is no additional information on toxin peptides and venom components to clarify the toxic effect of the M. gibbosus sting. Biochemical characterization of the venom was performed using different protocols and techniques following a bioassay-guided strategy (HPLC, mass spectrometry and Edman degradation sequencing). Venom fractions were tested in electrophysiological assays on a panel of six K(+) channels (K(v)1.1-1.6) by using the two-electrode voltage clamp technique. Three new α-KTx peptides were found and called MegKTx1, MegKTx2 and MegKTx3 (M. gibbosus, K(+) channel toxin number 1-3). A cDNA library from the telson was constructed and specific screening of transcripts was performed. Biochemical and molecular characterization of MegKTx peptides and transcripts shows a relation with toxins of three different α-KTx subfamilies (α-KTx3.x, α-KTx9.x and α-KTx16.x). Copyright © 2012 Elsevier Ltd. All rights reserved.

  15. Contemporary and historical evolutionary processes interact to shape patterns of within-lake phenotypic divergences in polyphenic pumpkinseed sunfish, Lepomis gibbosus

    PubMed Central

    Weese, Dylan J; Ferguson, Moira M; Robinson, Beren W

    2012-01-01

    Historical and contemporary evolutionary processes can both contribute to patterns of phenotypic variation among populations of a species. Recent studies are revealing how interactions between historical and contemporary processes better explain observed patterns of phenotypic divergence than either process alone. Here, we investigate the roles of evolutionary history and adaptation to current environmental conditions in structuring phenotypic variation among polyphenic populations of sunfish inhabiting 12 postglacial lakes in eastern North America. The pumpkinseed sunfish polyphenism includes sympatric ecomorphs specialized for littoral or pelagic lake habitats. First, we use population genetic methods to test the evolutionary independence of within-lake phenotypic divergences of ecomorphs and to describe patterns of genetic structure among lake populations that clustered into three geographical groupings. We then used multivariate analysis of covariance (MANCOVA) to partition body shape variation (quantified with geometric morphometrics) among the effects of evolutionary history (reflecting phenotypic variation among genetic clusters), the shared phenotypic response of all populations to alternate habitats within lakes (reflecting adaptation to contemporary conditions), and unique phenotypic responses to habitats within lakes nested within genetic clusters. All effects had a significant influence on body form, but the effects of history and the interaction between history and contemporary habitat were larger than contemporary processes in structuring phenotypic variation. This highlights how divergence can be better understood against a known backdrop of evolutionary history. PMID:22822436

  16. Contemporary and historical evolutionary processes interact to shape patterns of within-lake phenotypic divergences in polyphenic pumpkinseed sunfish, Lepomis gibbosus.

    PubMed

    Weese, Dylan J; Ferguson, Moira M; Robinson, Beren W

    2012-03-01

    Historical and contemporary evolutionary processes can both contribute to patterns of phenotypic variation among populations of a species. Recent studies are revealing how interactions between historical and contemporary processes better explain observed patterns of phenotypic divergence than either process alone. Here, we investigate the roles of evolutionary history and adaptation to current environmental conditions in structuring phenotypic variation among polyphenic populations of sunfish inhabiting 12 postglacial lakes in eastern North America. The pumpkinseed sunfish polyphenism includes sympatric ecomorphs specialized for littoral or pelagic lake habitats. First, we use population genetic methods to test the evolutionary independence of within-lake phenotypic divergences of ecomorphs and to describe patterns of genetic structure among lake populations that clustered into three geographical groupings. We then used multivariate analysis of covariance (MANCOVA) to partition body shape variation (quantified with geometric morphometrics) among the effects of evolutionary history (reflecting phenotypic variation among genetic clusters), the shared phenotypic response of all populations to alternate habitats within lakes (reflecting adaptation to contemporary conditions), and unique phenotypic responses to habitats within lakes nested within genetic clusters. All effects had a significant influence on body form, but the effects of history and the interaction between history and contemporary habitat were larger than contemporary processes in structuring phenotypic variation. This highlights how divergence can be better understood against a known backdrop of evolutionary history.

  17. Mesobuthus gibbosus (Scorpiones: Buthidae) on the island of Rhodes -- hybridization between Ulysses' stowaways and native scorpions?

    PubMed

    Gantenbein, B; Largiadèr, C R

    2002-05-01

    Allozyme data suggest that the Rhodes population of Mesobuthus gibbosus is a hybrid population of recent origin. Namely, it is a mixture between an autochthonous population and an artificially introduced population probably from the Greek mainland. All samples were mainly composed of F1 hybrid genotypes and genotypes either fixed for autochthonous or introduced alleles. Back-cross hybrid genotypes were very rare. Mitochondrial DNA analysis, in contrast, revealed only one group of closely related haplotypes that are unique for the Rhodes populations, thus suggesting asymmetric introgression of the two marker classes.

  18. Fossil calibrations and molecular divergence time estimates in centrarchid fishes (Teleostei: Centrarchidae).

    PubMed

    Near, Thomas J; Bolnick, Daniel I; Wainwright, Peter C

    2005-08-01

    Molecular clock methods allow biologists to estimate divergence times, which in turn play an important role in comparative studies of many evolutionary processes. It is well known that molecular age estimates can be biased by heterogeneity in rates of molecular evolution, but less attention has been paid to the issue of potentially erroneous fossil calibrations. In this study we estimate the timing of diversification in Centrarchidae, an endemic major lineage of the diverse North American freshwater fish fauna, through a new approach to fossil calibration and molecular evolutionary model selection. Given a completely resolved multi-gene molecular phylogeny and a set of multiple fossil-inferred age estimates, we tested for potentially erroneous fossil calibrations using a recently developed fossil cross-validation. We also used fossil information to guide the selection of the optimal molecular evolutionary model with a new fossil jackknife method in a fossil-based model cross-validation. The centrarchid phylogeny resulted from a mixed-model Bayesian strategy that included 14 separate data partitions sampled from three mtDNA and four nuclear genes. Ten of the 31 interspecific nodes in the centrarchid phylogeny were assigned a minimal age estimate from the centrarchid fossil record. Our analyses identified four fossil dates that were inconsistent with the other fossils, and we removed them from the molecular dating analysis. Using fossil-based model cross-validation to determine the optimal smoothing value in penalized likelihood analysis, and six mutually consistent fossil calibrations, the age of the most recent common ancestor of Centrarchidae was 33.59 million years ago (mya). Penalized likelihood analyses of individual data partitions all converged on a very similar age estimate for this node, indicating that rate heterogeneity among data partitions is not confounding our analyses. These results place the origin of the centrarchid radiation at a time of major

  19. Photo-induced toxicity of polycyclic aromatic hydrocarbons to fish (Lepomis spp. , Lepomis macrochirus, and Pimephales promelas)

    SciTech Connect

    Oris, J.T.

    1985-01-01

    The acute toxicity of polycyclic aromatic hydrocarbons (PAH) to fish in the presence of solar radiation has been assessed. These studies were conducted in a laboratory system under simulated sunlight. Anthracene, a linear 3-ring PAH was used as a model compound in the examination of light intensity and photoperiod effects, the elucidation of possible sites and modes of toxic action, and the development of an environmental hazard assessment. The primary test species in these studies was juvenile sunfish (Lepomis spp., and Lepomis macrochirus). Eleven other PAH were examined for potential photo-activity with larvae of the fathead minnow (Pimephales promelas). A structure-activity relationship has been developed based on molecular structure and photochemical properties which can predictively classify a compound as being phototoxic or non-phototoxic. The results of these experiments are environmentally significant since when compared to current natural PAH concentrations in water and in fish tissue, there are waters in which photo-induced PAH toxicity may presently occur. It is concluded that solar radiation is an important accessory parameter that deserves consideration in the toxicity assessment of PAH in the aquatic environment.

  20. Physiological tradeoffs may underlie the evolution of hypoxia tolerance and exercise performance in sunfish (Centrarchidae).

    PubMed

    Crans, Kyle D; Pranckevicius, Nicole A; Scott, Graham R

    2015-10-01

    Tradeoffs between hypoxia tolerance and aerobic exercise performance appear to exist in some fish taxa, even though both of these traits are often associated with a high O2 transport capacity. We examined the physiological basis for this potential tradeoff in four species of sunfish from the family Centrarchidae. Hypoxia tolerance was greatest in rock bass, intermediate in pumpkinseed and bluegill and lowest in largemouth bass, based on measurements of critical O2 tension (Pcrit) and O2 tension at loss of equilibrium (PO2 at LOE). Consistent with there being a tradeoff between hypoxia tolerance and aerobic exercise capacity, the least hypoxia-tolerant species had the highest critical swimming speed (Ucrit) during normoxia and suffered the greatest decrease in Ucrit in hypoxia. There was also a positive correlation between Ucrit in normoxia and PO2 at LOE, which remained significant after accounting for phylogeny using phylogenetically independent contrasts. Several sub-organismal traits appeared to contribute to both hypoxia tolerance and aerobic exercise capacity (reflected by traits that were highest in both rock bass and largemouth bass), such as the gas-exchange surface area of the gills, the pH sensitivity of haemoglobin-O2 affinity, and the activities of lactate dehydrogenase and the gluconeogenic enzyme phosphoenolpyruvate carboxykinase in the liver. Some other sub-organismal traits were uniquely associated with either hypoxia tolerance (low sensitivity of haemoglobin-O2 affinity to organic phosphates, high pyruvate kinase and lactate dehydrogenase activities in the heart) or aerobic exercise capacity (capillarity and fibre size of the axial swimming muscle). Therefore, the cumulative influence of a variety of respiratory and metabolic traits can result in physiological tradeoffs associated with the evolution of hypoxia tolerance and aerobic exercise performance in fish.

  1. The effects of urbanization on Lepomis macrochirus using the comet assay

    EPA Science Inventory

    Urbanization has been linked to increased concentrations of polycyclic aromatic hydrocarbons in natural waterways. This study was designed to examine the impact of urbanization and a wastewater treatment plant by investigating the impact on field-collected bluegill (Lepomis macr...

  2. The effects of urbanization on Lepomis macrochirus using the comet assay

    EPA Science Inventory

    Urbanization has been linked to increased concentrations of polycyclic aromatic hydrocarbons in natural waterways. This study was designed to examine the impact of urbanization and a wastewater treatment plant by investigating the impact on field-collected bluegill (Lepomis macr...

  3. Mercury concentrations of bluegill (Lepomis macrochirus) vary by sex

    USGS Publications Warehouse

    Madenjian, Charles P.; Francis, James T.; Braunscheidel, Jeffrey J.; Bohr, Joseph R.; Geiger, Matthew J.; Knottnerus, G. Mark

    2015-01-01

    Patterns in relative differences in contaminant concentrations between the sexes across many species of fish may reveal clues for important behavioral and physiological differences between the sexes, and may also be useful in developing fish consumption advisories and efficient designs for programs meant to monitor contaminant levels in fish. We determined skin-off fillet and whole-fish total mercury (Hg) concentrations of 28 adult female and 26 adult male bluegills (Lepomis macrochirus) from Squaw Lake, Oakland County, Michigan (MI), USA. Bioenergetics modeling was used to quantify the effect of growth dilution on the difference in Hg concentrations between the sexes. On average, skin-off fillet and whole-fish Hg concentrations were 25.4% higher and 26.6% higher, respectively, in females compared with males. Thus, the relative difference in Hg concentrations between the sexes for skin-off fillets was nearly identical to that for whole fish. However, mean skin-off fillet Hg concentration (363 ng/g) was 2.3 times greater than mean whole-fish Hg concentration (155 ng/g). Males grew substantially faster than females, and bioenergetics modeling results indicated that the growth dilution effect could account for females having 14.4% higher Hg concentrations than males. Our findings should be useful in revising fish consumption advisories.

  4. The Mediterranean scorpion Mesobuthus gibbosus (Scorpiones, Buthidae): transcriptome analysis and organization of the genome encoding chlorotoxin-like peptides

    PubMed Central

    2014-01-01

    Background Transcrof toxin genes of scorpion species have been published. Up to this moment, no information on the gene characterization of M. gibbosus is available. Results This study provides the first insight into gene expression in venom glands from M. gibbosus scorpion. A cDNA library was generated from the venom glands and subsequently analyzed (301 clones). Sequences from 177 high-quality ESTs were grouped as 48 Mgib sequences, of those 48 sequences, 40 (29 “singletons” and 11 “contigs”) correspond with one or more ESTs. We identified putative precursor sequences and were grouped them in different categories (39 unique transcripts, one with alternative reading frames), resulting in the identification of 12 new toxin-like and 5 antimicrobial precursors (transcripts). The analysis of the gene families revealed several new components categorized among various toxin families with effect on ion channels. Sequence analysis of a new KTx precursor provides evidence to validate a new KTx subfamily (α-KTx 27.x). A second part of this work involves the genomic organization of three Meg-chlorotoxin-like genes (ClTxs). Genomic DNA sequence reveals close similarities (presence of one same-phase intron) with the sole genomic organization of chlorotoxins ever reported (from M. martensii). Conclusions Transcriptome analysis is a powerful strategy that provides complete information of the gene expression and molecular diversity of the venom glands (telson). In this work, we generated the first catalogue of the gene expression and genomic organization of toxins from M. gibbosus. Our result represents a relevant contribution to the knowledge of toxin transcripts and complementary information related with other cell function proteins and venom peptide transcripts. The genomic organization of the chlorotoxin genes may help to understand the diversity of this gene family. PMID:24746279

  5. Uptake, biotransformation, and elimination of rotenone by bluegills (Lepomis macrochirus )

    USGS Publications Warehouse

    Gingerich, W.H.; Rach, J.J.

    1985-01-01

    Yearling bluegills (Lepomis macrochirus) were exposed to sublethal concentrations of [14C]rotenone (5.2 μg/l) for 30 days in a continuous flow exposure system and then transferred to clean, flowing water for an additional 21-day depuration period. Rates of uptake and elimination and profile of the rotenoid metabolites in head, viscera, and carcass components were evaluated by 14C counting and by high performance liquid chromatography. Total [14C]rotenone derived activity was relatively uniform in all body components within 3 days after initial exposure and remained constant during the ensuing 27 days of exposure. Initial uptake rate coefficients were highest in viscera (Ku = 80· h -1) and were nearly identical for head (Ku = 14 · h) and carcass (Ku = 10 · h-1). Analyses of tissue extracts by high performance liquid chromatography confirmed the presence of at least six biotransformation products of rotenone. More than 60% of the activity extracted from viscera was present as a single peak which represented a compound that was extremely soluble in water. Rotenone composed only 0.3% of the extractable activity in viscera taken from fish exposed to rotenone for 30 days; however, rotenone accounted for 15.4% of extractable activity in the head and 20.1% in the carcass components. Rotenolone and 6',7'-dihydro-6'-,7'--dihydroxyrotenolone were tentatively identified as oxidation products in all tissue extracts. Elimination of 14C activity from all body components was biphasic; both phases followed first-order kinetics. The rate of elimination was nearly equal for all body components during the initial phase but was most rapid from viscera during the second phase of elimination. Bioconcentration factors for the head, viscera, and carcass were 165, 3,550, and 125, respectively, when calculated on the basis of total 14C activity but only 25.4, 11, and 26 when calculated as the concentration of parent material.

  6. Growth, life history, and species interactions of bluegill sunfish (Lepomis macrochirus) under heavy predation

    SciTech Connect

    Belk, Mark Carl

    1992-01-01

    The purpose of this study was, first, to compare growth and life history characteristics of an unfished population of bluegill sunfish (Lepomis macrochirus) in the presence of an abundant predator population to characteristic exhibited by bluegills in typical southeastern US reservoirs where the abundance of predators is reduced, but fishing is increased. The second objective was to determine if differences observed between populations were determined genetically or environmentally.

  7. Aggressive interactions between the invasive Rio Grande cichlid (Herichthys cyanoguttatus) and native bluegill (Lepomis macrochirus), with notes on redspotted sunfish (Lepomis miniatus)

    USGS Publications Warehouse

    Lorenz, O. Thomas; O' Connell, Martin T.; Schofield, Pamela J.

    2010-01-01

    The Rio Grande cichlid (Herichthys cyanoguttatus) has been established in the Greater New Orleans Metropolitan area for at least 20 years, and its effect on native fishes is unknown. Behavioral trials were performed to determine if aggressive interactions occur between invasive H. cyanoguttatus and native bluegill (Lepomis macrochirus). When defending a territory as the resident, L. macrochirus were markedly aggressive, averaging 11.6 aggressive actions per lO-min behavioral trial. In contrast, L. macrochirus were extremely passive as invaders, with 0.5 aggressive actions per trial. Herichthys cyanoguttatus were equally aggressive as residents and as invaders, averaging 4.9 and 6.0 aggressive actions per trial, respectively. Herichthys cyanoguttatus interacted aggressively with native species whether they held territory or not, indicating that this invasive species may have fundamentally different strategies of aggression compared with native L. macrochirus. These differences may explain the continued success of H. cyanoguttatus as an invasive fish in southeastern Louisiana.

  8. Effect of winter feeding frequency on growth, survival, and fatty acid metabolism of juvenile bluegill (Lepomis macrochirus) and hybrid bluegill (L.cyanellus ×L. macrochirus)

    USDA-ARS?s Scientific Manuscript database

    There has been an increasing global demand for large bluegill (Lepomis macrochirus) and its hybrid (female Lepomis cyanellus x male L. macrochirus) to supply the food-fish market. However, production of market-size bluegill requires producers to overwinter them in temperate regions. Winter fish mort...

  9. 238,234U contents on Lepomis Cyanellus from San Marcos dam located in a uraniferous area

    NASA Astrophysics Data System (ADS)

    Lares, Magaly Cabral; Luna-Porres, Mayra Y.; Montero-Cabrera, María E.; Renteria-Villalobos, Marusia

    2014-07-01

    Fish species are suitable biomonitors of radioisotopes in aquatic systems. In the present study, it was made the determination of uranium isotopic contents on fish fillet (Lepomis Cyanellus) from San Marcos dam which is located in uranium mineralized zone. Uranium activity concentrations (AC) in fish samples were obtained on wet weight (ww), using liquid scintillation. 238U and 234U AC in fish fillet ranged from 0.0004 to 0.0167 Bq kg-1, and from 0.0013 to 0.0394 Bq kg-1, respectively. The activity ratio (234U/overflow="scroll">238U) in fish fillet ranged from 2.2 to 8.8. Lepomis cyanellus from San Marcos dam shows bioaccumulation factor (FB) of 0.6 L kg-1. The results suggest that the Lepomis Cyanellus in environments with high U contents tends to have a greater bioaccumulation compared to others.

  10. THE SENSIBILITY OF THE SUN-FISH, LEPOMIS, TO MONOCHROMATIC RADIATION OF LOW INTENSITIES

    PubMed Central

    Grundfest, Harry

    1932-01-01

    1. A test is proposed of the hypothesis that visual purple is the photosensitive substance concerned in dim vision. It is based on the fact that fish visual purple is different from that of other vertebrates. If the hypothesis is correct, the fish dim-visibility function should be different from that of other vertebrates and should be determined by the absorption spectrum of its visual purple. 2. A new method is described for obtaining the visibility function of fish, in quantitative terms. It depends on the measurement of the least amounts of various spectral energies which will produce a visual orienting response to the displacement of a constant background. 3. Data are presented on thirteen animals. It is shown that the maximum of the visibility function is identical with the maximum of the absorption spectrum of fish visual purple. The shapes of the visibility curves obtained are, however, variable and different from that of the absorption spectrum. 4. The possibility that Lepomis visual purple is different from that of other fish is ruled out by a series of measurements which confirm the results of Koettgen and Abelsdorff on other fish. 5. Reasons are given for the conclusion that there are present in Lepomis special conditions which distort the visibility curve out of true agreement with that predictable from the absorption spectrum of its visual purple. The suggestion is made that the presence of light absorbing, but not light sensitive, pigments is responsible for this distortion. One of these pigments may perhaps be carotin while the second is unspecified. PMID:19872647

  11. Characterization of a new picornavirus isolated from the freshwater fish Lepomis macrochirus.

    PubMed

    Barbknecht, Marisa; Sepsenwol, Sol; Leis, Eric; Tuttle-Lau, Maren; Gaikowski, Mark; Knowles, Nick J; Lasee, Becky; Hoffman, Michael A

    2014-03-01

    The freshwater fish Lepomis macrochirus (bluegill) is common to North American waters, and important both ecologically and as a sport fish. In 2001 an unknown virus was isolated from bluegills following a bluegill fish kill. This virus was identified as a picornavirus [termed bluegill picornavirus (BGPV)] and a diagnostic reverse transcriptase PCR was developed. A survey of bluegills in Wisconsin waters showed the presence of BGPV in 5 of 17 waters sampled, suggesting the virus is widespread in bluegill populations. Experimental infections of bluegills confirmed that BGPV can cause morbidity and mortality in bluegills. Molecular characterization of BGPV revealed several distinct genome characteristics, the most unusual of which is the presence of a short poly(C) tract in the 3' UTR. Additionally, the genome encodes a polyprotein lacking a leader peptide and a VP0 maturation cleavage site, and is predicted to encode two distinct 2A proteins. Sequence comparison showed that the virus is most closely related to a phylogenetic cluster of picornaviruses that includes the genera Aquamavirus, Avihepatovirus and Parechovirus. However, it is distinct enough, for example sharing only about 38% sequence identity to the parechoviruses in the 3D region, that it may represent a new genus in the family Picornaviridae.

  12. Toxicity and bioaccumulation of waterborne and dietary selenium in juvenile bluegill (Lepomis macrochirus)

    USGS Publications Warehouse

    Cleveland, Laverne; Little, Edward E.; Buckler, Denny R.; Wiedmeyer, Raymond H.

    1993-01-01

    Juvenile bluegill (Lepomis macrochirus) were exposed to waterborne selenium as a 6:1 mixture of selenate to selenite (as Se) for 60 d and to dietary seleno-l-methionine for 90 d. Measured concentrations of total selenium in the waterborne exposure ranged from 0.16 to 2.8 mg/l, and concentrations of seleno-l-methionine in the test diet ranged from 2.3 to 25.0 mg/kg wet weight. Mortality, body weight, condition factor, swimming and feeding behavior, aggression, and selenium tissue residues were monitored during the tests. Increased mortality at measured concentrations of 0.64 mg Se/l and greater was the primary adverse effect of waterborne selenium on the juvenile bluegill. Bluegill exposed to 2.8 mg/l of waterborne Se for 30 d exhibited a significant reduction in condition factor (K), whereas dietary exposure of bluegill to 25 mg Se/kg for 30 d and 13 mg Se/kg or greater for 90 d elicited significant reductions in K. Mortality and swimming activity of bluegill were not affected in the dietary exposure. Net accumulation of Se from both water and diet was directly related to exposure concentration. Bioconcentration factors ranged from 5 to 7 for bluegill exposed to waterborne Se and from 0.5 to 1.0 for fish exposed to dietary Se. Results of these laboratory tests indicate that survival of bluegill may be impaired in natural waters with elevated Se concentrations.

  13. Reproductive Disruption in Wild Longear Sunfish (Lepomis megalotis) Exposed to Kraft Mill Effluent

    PubMed Central

    Fentress, Jennifer A.; Steele, Stacy L.; Bart, Henry L.; Cheek, Ann Oliver

    2006-01-01

    Worldwide, wild fish living in rivers receiving municipal and industrial discharges may experience endocrine disruption as a result of exposure to anthropogenic pollutants. The purpose of this study was to evaluate the hormonal status of wild fish in a U.S. river receiving unbleached kraft and recycled pulp mill effluent (Pearl River at Bogalusa, LA). We evaluated two alternative hypotheses: the effluent contained constituents that suppressed male and female reproduction, or it contained an androgenic substance that masculinized females. To evaluate the likelihood of fish exposure to effluent, we marked 697 longear sunfish (Lepomis megalotis) over a 2-year period; 83% of recaptured fish were found at the site of initial capture, and only one fish migrated from an effluent-receiving site to a reference site. We can reasonably assume that fish captured from an effluent-receiving site are residents, not transitory migrants. To diagnose endocrine disruption, we measured sex steroid hormone [17β-estradiol (E2), testosterone (T), and 11-ketotestosterone (11KT)] and vitellogenin (VTG) concentrations in male and female longear sunfish captured at two sites upstream and two sites downstream of the effluent outfall. Kraft pulp mill effluent did not affect male reproductive physiology but did suppress female T and VTG levels when effluent constituted ≥ 1% of river flow. Masculinization was not observed. Longear sunfish in the Pearl River experience moderate reproductive suppression in response to unbleached kraft and recycled pulp mill effluent. PMID:16393656

  14. Elevated selenium levels in bluegills and their effect on reproduction. [Lepomis macrochirus

    SciTech Connect

    Gillespie, R.B.

    1985-01-01

    A series of 18 artificial crosses of bluegills, Lepomis macrochirus, from Hyco Reservoir, North Carolina (mean Se = 7.94 ppm) and Roxboro City Lake, North Carolina (mean Se = 0.38 ppm) were generated. Neither percent fertilization nor percent hatch differed significantly among the parent combinations. However, all crosses of females with high Se body burdens resulted in larvae with edema; larvae from all crosses of females with low Se body burdens were normal. No differences were found in morphology of the membranes from immature ova between females of the two reservoirs. Sections of heart and intestines appear similar between larvae from females of Hyco Reservoir and Roxboro City Lake suggesting that edema occurs from physiological impairment and not from developmental abnormalities. Mean Se levels in the gonads and carcass of adult bluegills were more than 20 times higher in fishes from Hyco Reservoir than in those from Roxboro City Lake. The high Se concentration in ovaries of Hyco Reservoir bluegills, coupled with high Se levels in larvae from artificial crosses indicated that Se was transferred from females to offspring and resulted in larval edema. /sup 75/Se-selenomethionine was fed to adult bluegills. After 12 weeks of feeding, liver and testis had the highest /sup 75/Se activities according to gamma activity assays while ovary, heart and skeletal muscle had the lowest activities.

  15. Trade-offs between performance and variability in the escape responses of bluegill sunfish (Lepomis macrochirus)

    PubMed Central

    Hitchcock, Amanda C.; Chen, Tiffany; Connolly, Erin; Darakananda, Karin; Jeong, Janet; Quist, Arbor; Robbins, Allison; Ellerby, David J.

    2015-01-01

    Successful predator evasion is essential to the fitness of many animals. Variation in escape behaviour may be adaptive as it reduces predictability, enhancing escape success. High escape velocities and accelerations also increase escape success, but biomechanical factors likely constrain the behavioural range over which performance can be maximized. There may therefore be a trade-off between variation and performance during escape responses. We have used bluegill sunfish (Lepomis macrochirus) escape responses to examine this potential trade-off, determining the full repertoire of escape behaviour for individual bluegill sunfish and linking this to performance as indicated by escape velocity and acceleration. Fish escapes involve an initial C-bend of the body axis, followed by variable steering movements. These generate thrust and establish the escape direction. Directional changes during the initial C-bend were less variable than the final escape angle, and the most frequent directions were associated with high escape velocity. Significant inter-individual differences in escape angles magnified the overall variation, maintaining unpredictability from a predator perspective. Steering in the latter stages of the escape to establish the final escape trajectory also affected performance, with turns away from the stimulus associated with reduced velocity. This suggests that modulation of escape behaviour by steering may also have an associated performance cost. This has important implications for understanding the scope and control of intra- and inter-individual variation in escape behaviour and the associated costs and benefits. PMID:25910940

  16. Mechanisms of force production during linear accelerations in bluegill sunfish Lepomis macrochirus

    NASA Astrophysics Data System (ADS)

    Tytell, Eric D.; Wise, Tyler N.; Boden, Alexandra L.; Sanders, Erin K.; Schwalbe, Margot A. B.

    2016-11-01

    In nature, fish rarely swim steadily. Although unsteady behaviors are common, we know little about how fish change their swimming kinematics for routine accelerations, and how these changes affect the fluid dynamic forces and the wake produced. To study force production during acceleration, particle image velocimetry was used to quantify the wake of bluegill sunfish Lepomis macrochirus and to estimate the pressure field during linear accelerations and steady swimming. We separated "steady" and "unsteady" trials and quantified the forward acceleration using inertial measurement units. Compared to steady sequences, unsteady sequences had larger accelerations and higher body amplitudes. The wake consisted of single vortices shed during each tail movement (a '2S' wake). The structure did not change during acceleration, but the circulation of the vortices increased, resulting in larger forces. A fish swimming unsteadily produced significantly more force than the same fish swimming steadily, even when the accelerations were the same. This increase is likely due to increased added mass during unsteady swimming, as a result of the larger body amplitude. Pressure estimates suggest that the increase in force is correlated with more low pressure regions on the anterior body. This work was supported by ARO W911NF-14-1-0494 and NSF RCN-PLS 1062052.

  17. Phylogeography of the bluegill sunfish, Lepomis macrochirus, in the Mississippi River Basin.

    PubMed

    Kawamura, Kouichi; Yonekura, Ryuji; Katano, Osamu; Taniguchi, Yoshinori; Saitoh, Kenji

    2009-01-01

    The Mississippi River Basin supports the richest fish fauna in eastern North America and has played a key role in the maintenance of fish biodiversity, especially as a refuge for freshwater fishes during glaciations. In this study, we investigated the phylogeography of the bluegill sunfish, Lepomis macrochirus, in eastern North America, using complete sequence of the mitochondrial ND1 gene from 369 samples collected at 15 sites. Phylogenetic analysis revealed two major lineages (northern and southern clades) in a parsimony network. A sympatric distribution of the lineages was widely observed in the Mississippi Basin. Sequence diversity in the two lineages was significantly lower in glaciated regions around the Great Lakes than in unglaciated regions. The two lineages were estimated to have diverged in the Kansan glaciation, and refugia for both existed around the Ouachita Highlands. The southern clade dispersed during the Yasmouth Interglacial, prior to the dispersal of the northern clade during the Sangamon Interglacial. In the northern clade, low genetic diversity and population fragmentation inferred by nested clade analysis (NCA) were considered due to bottleneck events in the Wisconsin glaciation, while the southern clade showed isolation by distance in a Mantel test. A difference in demographic fluctuation suggests that sympatry of the two lineages has resulted from recent secondary admixture through the range expansion of the northern clade in the post-Pleistocene. Large-scale admixture of multiple mtDNA lineages in L. macrochirus, which has not been recorded in other fishes in the Mississippi River Basin, may result from their high vagility.

  18. Phenotypic variation and vulnerability to predation in juvenile bluegill sunfish (Lepomis macrochirus)

    USGS Publications Warehouse

    Chipps, S.R.; Dunbar, J.A.; Wahl, David H.

    2004-01-01

    Bluegill sunfish (Lepomis macrochirus) are known to diversify into two forms specialized for foraging on either limnetic or littoral prey. Because juvenile bluegills seek vegetative cover in the presence of largemouth bass (Micropterus salmoides) predators, natural selection should favor the littoral body design at size ranges most vulnerable to predation. Yet within bluegill populations, both limnetic and littoral forms occur where vegetation and predators are present. While adaptive for foraging in different environments, does habitat-linked phenotypic variation also influence predator evasiveness for juvenile bluegills? We evaluate this question by quantifying susceptibility to predation for two groups of morphologically distinct bluegills; a limnetic form characteristic of bluegills inhabiting open water areas (limnetic bluegill) and a littoral form characteristic of bluegills inhabiting dense vegetation (littoral bluegill). In a series of predation trials, we found that bluegill behaviors differed in open water habitat but not in simulated vegetation. In open water habitat, limnetic bluegills formed more dense shoaling aggregations, maintained a larger distance from the predator, and required longer amounts of time to capture than littoral bluegill. When provided with simulated vegetation, largemouth bass spent longer amounts of time pursuing littoral bluegill and captured significantly fewer littoral bluegills than limnetic fish. Hence, morphological and behavioral variation in bluegills was linked to differential susceptibility to predation in open water and vegetated environments. Combined with previous studies, these findings show that morphological and behavioral adaptations enhance both foraging performance and predator evasiveness in different lake habitats.

  19. Reproductive disruption in wild longear sunfish (Lepomis megalotis) exposed to kraft mill effluent.

    PubMed

    Fentress, Jennifer A; Steele, Stacy L; Bart, Henry L; Cheek, Ann Oliver

    2006-01-01

    Worldwide, wild fish living in rivers receiving municipal and industrial discharges may experience endocrine disruption as a result of exposure to anthropogenic pollutants. The purpose of this study was to evaluate the hormonal status of wild fish in a U.S. river receiving unbleached kraft and recycled pulp mill effluent (Pearl River at Bogalusa, LA). We evaluated two alternative hypotheses: the effluent contained constituents that suppressed male and female reproduction, or it contained an androgenic substance that masculinized females. To evaluate the likelihood of fish exposure to effluent, we marked 697 longear sunfish (Lepomis megalotis) over a 2-year period; 83% of recaptured fish were found at the site of initial capture, and only one fish migrated from an effluent-receiving site to a reference site. We can reasonably assume that fish captured from an effluent-receiving site are residents, not transitory migrants. To diagnose endocrine disruption, we measured sex steroid hormone [17beta-estradiol (E2), testosterone (T), and 11-ketotestosterone (11KT)] and vitellogenin (VTG) concentrations in male and female longear sunfish captured at two sites upstream and two sites downstream of the effluent outfall. Kraft pulp mill effluent did not affect male reproductive physiology but did suppress female T and VTG levels when effluent constituted>or=1% of river flow. Masculinization was not observed. Longear sunfish in the Pearl River experience moderate reproductive suppression in response to unbleached kraft and recycled pulp mill effluent.

  20. Differential sensitivity of CYP1A to 3,3',4',4-tetrachlorobiphenyl and benzo(a)pyrene in two Lepomis species.

    PubMed

    Brammell, Ben F; Price, David J; Birge, Wesley J; Harmel-Laws, Eleana M; Hitron, J Andrew; Elskus, Adria A

    2010-06-01

    Although Lepomis species are abundant in a wide variety of habitats throughout North America and could serve as potentially valuable biomonitoring tools, few studies have examined the induction of pollutant biomarkers in this genus. We hypothesized that the induction of cytochrome P-450 1A (CYP1A), a sensitive and widely used indicator of response to aquatic contaminants, would serve as an effective biomarker of organic pollutant exposure in Lepomis species. We examined the response of CYP1A and two of the major pollutant-responsive phase II enzymes, glutathione S-transferase (GST), and uridine diphosphate glucuronyltransferase (UDPGT), in Lepomis exposed to organic pollutants under laboratory and field conditions. Two Lepomis species (longear sunfish, Lepomis megalottis and bluegill, Lepomis macrochirus) were exposed in the laboratory via intraperitoneal injection to corn oil (vehicle), benzo(a)pyrene (BaP) (10 and 50mg/kg), a polynuclear aromatic hydrocarbon (PAH) or 3,4,3',4'-tetrachlorobiphenyl (PCB 77) (0.1 and 1.0mg/kg), a dioxin-like planar halogenated aromatic hydrocarbon (HAH), and sacrificed 2 (BaP) or 7 (corn oil, PCB77) days later. Lepomis hepatic CYP1A exhibited differential sensitivity to these two classes of environmental contaminants. CYP1A activity was weakly induced in bluegill exposed to 1.0mg/kg PCB 77 (3 fold induction over controls) but strongly induced in both bluegill and longear sunfish exposed to 50mg/kg BaP (37 and 15 fold induction over controls, respectively). In contrast, hepatic GST activity in both species remained unchanged following the treatment with either compound and hepatic UDPGT activity, which was assessed only in BaP-treated longear sunfish, was unaffected by that chemical, indicating these phase II enzymes may not be sensitive pollutant biomarkers in this genus. Further, longear sunfish collected from a PCB contaminated site displayed relatively low levels of CYP1A activity despite PCB body burdens associated with strong

  1. Determination of ten perfluorinated compounds in bluegill sunfish (Lepomis macrochirus) fillets

    SciTech Connect

    Delinsky, Amy D.; Strynar, Mark J.; Nakayama, Shoji F.; Varns, Jerry L.; Ye, XiBiao; McCann, Patricia J.; Lindstrom, Andrew B.

    2009-11-15

    A rigorous solid phase extraction/liquid chromatography/tandem mass spectrometry method for the measurement of 10 perfluorinated compounds (PFCs) in fish fillets is described and applied to fillets of bluegill sunfish (Lepomis macrochirus) collected from selected areas of Minnesota and North Carolina. The 4 PFC analytes routinely detected in bluegill fillets were perfluorooctane sulfonate (PFOS), perfluorodecanoic acid (C10), perfluoroundecanoic acid (C11), and perflurododecanoic acid (C12). Measures of method accuracy and precision for these compounds showed that calculated concentrations of PFCs in spiked samples differed by less than 20% from their theoretical values and that the %RSD for repeated measurements was less than 20%. Minnesota samples were collected from areas of the Mississippi River near historical PFC sources, from the St. Croix River as a background site, and from Lake Calhoun, which has no documented PFC sources. PFOS was the most prevalent PFC found in the Minnesota samples, with median concentrations of 47.0-102 ng/g at locations along the Mississippi River, 2.08 ng/g in the St. Croix River, and 275 ng/g in Lake Calhoun. North Carolina samples were collected from two rivers with no known historical PFC sources. PFOS was the predominant analyte in fish taken from the Haw and Deep Rivers, with median concentrations of 30.3 and 62.2 ng/g, respectively. Concentrations of C10, C11, and C12 in NC samples were among the highest reported in the literature, with respective median values of 9.08, 23.9, and 6.60 ng/g in fish from the Haw River and 2.90, 9.15, and 3.46 ng/g in fish from the Deep River. These results suggest that PFC contamination in freshwater fish may not be limited to areas with known historical PFC inputs.

  2. Functional morphology and hydrodynamics of backward swimming in bluegill sunfish, Lepomis macrochirus.

    PubMed

    Flammang, Brooke E; Lauder, George V

    2016-10-01

    Most teleost fishes, like the bluegill sunfish Lepomis macrochirus, have multiple flexible fins that are used as modifiable control surfaces. This helps to make fish highly maneuverable, permitting behaviors like reversing direction of motion and swimming backwards without having to rotate body position. To answer the question of how fish swim backwards we used high-speed videography and electromyography to determine the kinematics and muscle activity necessary to produce reverse-direction propulsion in four bluegill sunfish. We found that, in contrast to slow forward swimming, low-speed backward swimming is a multi-fin behavior, utilizing the pectoral, dorsal, anal, and caudal fins. The pectoral fins alternate beats, each fin broadly flaring on the outstroke and feathered on the instroke. The dorsal fin and dorsal portion of the caudal fin move out of phase as do the anal fin and ventral portion of the caudal fin. Electromyography of muscles in the pectoral, dorsal, anal, and caudal fins demonstrated bilateral activation when these fins changed direction, suggesting that fins are stiffened at this time. In addition to backward propulsion by the pectoral fins, particle image velocimetry revealed that the dorsal and anal fins are capable of producing reverse momentum jets to propel the fish backward. Because teleost fishes are statically unstable, locomotion at slow speeds requires precise fin control to adequately balance torques produced about the center of mass. Therefore, the kinematics of backward swimming may be the result of compensation for rolling, pitching, and yawning instability. We suggest that asymmetric pectoral fin activity with feathering during adduction balances rolling instability. The ventral to dorsal undulatory wave on the caudal fin controls pitch instability and yaw instability encountered from pectoral-driven backward locomotion. Thrust generation from the dorsal and anal fins decreases the destabilizing effect of the long moment arm of the

  3. Three-dimensional analysis of scale morphology in bluegill sunfish, Lepomis macrochirus.

    PubMed

    Wainwright, Dylan K; Lauder, George V

    2016-06-01

    Fish scales are morphologically diverse among species, within species, and on individuals. Scales of bony fishes are often categorized into three main types: cycloid scales have smooth edges; spinoid scales have spines protruding from the body of the scale; ctenoid scales have interdigitating spines protruding from the posterior margin of the scale. For this study, we used two- and three-dimensional (2D and 3D) visualization techniques to investigate scale morphology of bluegill sunfish (Lepomis macrochirus) on different regions of the body. Micro-CT scanning was used to visualize individual scales taken from different regions, and a new technique called GelSight was used to rapidly measure the 3D surface structure and elevation profiles of in situ scale patches from different regions. We used these data to compare the surface morphology of scales from different regions, using morphological measurements and surface metrology metrics to develop a set of shape variables. We performed a discriminant function analysis to show that bluegill scales differ across the body - scales are cycloid on the opercle but ctenoid on the rest of the body, and the proportion of ctenii coverage increases ventrally on the fish. Scales on the opercle and just below the anterior spinous dorsal fin were smaller in height, length, and thickness than scales elsewhere on the body. Surface roughness did not appear to differ over the body of the fish, although scales at the start of the caudal peduncle had higher skew values than other scales, indicating they have a surface that contains more peaks than valleys. Scale shape also differs along the body, with scales near the base of the tail having a more elongated shape. This study adds to our knowledge of scale structure and diversity in fishes, and the 3D measurement of scale surface structure provides the basis for future testing of functional hypotheses relating scale morphology to locomotor performance.

  4. Use of behavioral endpoints to determine protective concentrations of the insecticide fonofos for bluegill (Lepomis macrochirus)

    USGS Publications Warehouse

    Fairchild, J.F.; Little, E.E.

    1999-01-01

    This research compared the results of laboratory and mesocosm studies to determine the effectiveness of using behavioral measures of sublethal exposure to define environmental concentration ranges that are protective of free-ranging populations of bluegill (Lepomis macrochirus) exposed to the organophophate insecticide fonofos. Thirty-day laboratory chronic studies were conducted to determine the relative sensitivity of standard (e.g. survival and growth) and non-standard behavioral (e.g. swimming capacity, feeding efficiency, and aggression) endpoints in predicting concentrations of fonofos protective of bluegill growth and survival. The lowest observable effect concentration (LOECs) for the standard measures of survival and growth was 5.6 ??g/L. Two behavioral endpoints were of similar sensitivity to the standard measures: swimming capacity, LOEC of 5.6 ??g/L; and prey strike frequency, LOEC of 5.6 ??g/L. However, aggressive interactions were ten-fold more sensitive than swimming or feeding behavior with a LOEC occurring at 0.6 ??g/L. Lab results were compared to an aquatic mesocosm study which exposed adult and juvenile bluegill to a 9.41 ??g/L concentration of fonofos. The dissipation half-life of fonofos was 5 days in 0.1 hectare aquatic mesocosms. Significant mortality among caged bluegill occurred within 4 days of exposure at 9.41 ??g/L. However, the 9.41 ??g/L concentration of fonofos had no statistically significant effects on survival, growth, reproduction, or total biomass of free-ranging populations of bluegill. We conclude from these studies that laboratory data can accurately estimate concentrations that are lethal in the field and that the use of behavioral endpoints can provide ecologically relevant, yet conservative estimates of concentrations that are protective of field populations.

  5. Effects of cadmium on juvenile bluegill (Lepomis macrochirus) foraging behavior and growth

    SciTech Connect

    Bryan, M.D.

    1993-01-01

    Standardized toxicity testing protocols for assessing chemical hazards to aquatic organisms inadequately consider behavioral effects of toxicants; yet, organisms behaving abnormally in the wild experience reduced growth, fitness, and higher mortality. This study determined the effects of cadmium (0, 30, 60, 120, and 240 [mu]g/L) on juvenile bluegill (Lepomis macrochirus) foraging behavior in three 28-d functional response experiments, and one 24-d multi-prey experiment. The study also examined how cadmium-altered behaviors contributed to reduced growth rates. Different sizes of Daphnia magna and D. pulez were used as prey in these experiments. The rate of change (i.e., trends over time) in the number of Daphnia attacker per unit time was the most consistently sensitive behavioral measure of sublethal stress in exposed bluegill; the lowest observed effect concentration (LOEC) for this metric was 30 [mu]g Cd/L. The magnitude and duration of effects on prey attack rates were inversely related to prey size; cadmium had a greater and more prolonged effect on fish foraging on small compared to large prey. Cadmium had little effect on prey capture efficiency and handling time. Patch switching efficiency, as measured by caloric gain per unit time, was not affected by cadmium exposure. Cadmium affected prey selection when preferred prey were scarce, but not when preferred prey were abundant. Evidence suggests that reduced consumption of Daphnia and altered prey selection were the result of cadmium-altered prey search strategy and perhaps reduced motivation to feed. Growth was significantly reduced in bluegill exposed to nominal concentrations of 30 [mu]g Cd/L in two of three experiments and at 60 [mu]g Cd/L in the third experiment. In managing environmental contaminants, exposure must be limited to concentrations that protect organisms' ability to carry-out their most basic and essential ecological activities (i.e., feeding, surviving, and reproducing).

  6. Median fin function in bluegill sunfish Lepomis macrochirus: streamwise vortex structure during steady swimming.

    PubMed

    Tytell, Eric D

    2006-04-01

    Fishes have an enormous diversity of body shapes and fin morphologies. From a hydrodynamic standpoint, the functional significance of this diversity is poorly understood, largely because the three-dimensional flow around swimming fish is almost completely unknown. Fully three-dimensional volumetric flow measurements are not currently feasible, but measurements in multiple transverse planes along the body can illuminate many of the important flow features. In this study, I analyze flow in the transverse plane at a range of positions around bluegill sunfish Lepomis macrochirus, from the trailing edges of the dorsal and anal fins to the near wake. Simultaneous particle image velocimetry and kinematic measurements were performed during swimming at 1.2 body lengths s(-1) to describe the streamwise vortex structure, to quantify the contributions of each fin to the vortex wake, and to assess the importance of three-dimensional flow effects in swimming. Sunfish produce streamwise vortices from at least eight distinct places, including both the dorsal and ventral margins of the soft dorsal and anal fins, and the tips and central notched region of the caudal fin. I propose a three-dimensional structure of the vortex wake in which these vortices from the caudal notch are elongated by the dorso-ventral cupping motion of the tail, producing a structure like a hairpin vortex in the caudal fin vortex ring. Vortices from the dorsal and anal fin persist into the wake, probably linking up with the caudal fin vortices. These dorsal and anal fin vortices do not differ significantly in circulation from the two caudal fin tip vortices. Because the circulations are equal and the length of the trailing edge of the caudal fin is approximately equal to the combined trailing edge length of the dorsal and anal fins, I argue that the two anterior median fins produce a total force that is comparable to that of the caudal fin. To provide additional detail on how different positions contribute to

  7. Speed-dependent intrinsic caudal fin muscle recruitment during steady swimming in bluegill sunfish, Lepomis macrochirus.

    PubMed

    Flammang, Brooke E; Lauder, George V

    2008-02-01

    There are approximately 50 muscles that control tail fin shape in most teleost fishes, and although myotomal muscle function has been extensively studied, little work has been done on the intrinsic musculature that controls and shapes the tail. In this study we measured electrical activity in intrinsic tail musculature to determine if these muscles are active during steady rectilinear locomotion, and to compare intrinsic muscle recruitment patterns to previous data on myotomal muscle fibers. Five bluegill sunfish (Lepomis macrochirus) were anaesthetized and electrode wires surgically placed into a total of 24 intrinsic caudal muscles, up to 13 at a time, and activity was correlated with synchronous recordings from myotomal fibers in the caudal peduncle. After recovery, fish swam steadily at speeds of 0.5, 1.2 and 2.0 L s(-1), while filmed from lateral, posterior and ventral views simultaneously at 250 frames s(-1). Comparison among speeds confirmed that muscle recruitment varies significantly with speed. At 0.5 L s(-1), the caudal fin was generally not used for propulsion, and swimming was accomplished primarily through body undulations. Intrinsic caudal muscle activity at this speed was intermittent and variable. At 1.2 and 2.0 L s(-1), the supracarinalis and infracarinalis muscles acted on the dorsal- and ventral-most fin rays, respectively, to expand the surface area of the caudal fin. The interradialis muscles adducted individual fin rays, dorsally to ventrally, following activation of the hypochordal longitudinalis. Contralateral muscle activity of interradialis muscles occurred as the caudal fin crossed the mean direction of travel and fin height was greatest, whereas ipsilateral activity of carinalis muscles occurred near points of maximum excursion of the fin, at speeds of 1.2 and 2.0 L s(-1), after fin height was lowest. Burst intensity increased with swimming speed, suggesting stiffening of the tail fin against imposed hydrodynamic loads. Activity

  8. Amount and identity of (/sup 14/C) residues in bluegills (Lepomis macrochirus) exposed to (/sup 14/C)triclopyr

    SciTech Connect

    Lickly, T.D.; Murphy, P.G.

    1987-01-01

    The level and identity of (/sup 14/C) residues in bluegills (Lepomis macrochirus) exposed to 2.5 mg/L (/sup 14/C) triclopyr (3,5,6-trichloro-2-pyridinyloxyacetic acid) have been determined. The highest level of radioactivity observed in the flesh of a fish at any time point (0.13 mg/kg, calculated as equivalent mg triclopyr/kg fish) was less than 5% of the fish exposure level of 2.5 mg/L, while the maximum level in the remainder (head, skin, and viscera) was about 95% (2.33 mg/kg) of the fish exposure level, indicating no concentrating effect. The principal components observed in the fish tissues were triclopyr, 3,5,6-trichloro-2-pyridinol, 2-methoxy-3,5,6-trichloropyridine and a conjugate. These components accounted for greater than 75% of all the residues observed.

  9. Will jumping snails prevail? Influence of near-future CO₂, temperature and hypoxia on respiratory performance in the tropical conch Gibberulus gibberulus gibbosus.

    PubMed

    Lefevre, Sjannie; Watson, Sue-Ann; Munday, Philip L; Nilsson, Göran E

    2015-10-01

    Tropical coral reef organisms are predicted to be especially sensitive to ocean warming because many already live close to their upper thermal limit, and the expected rise in ocean CO2 is proposed to further reduce thermal tolerance. Little, however, is known about the thermal sensitivity of a diverse and abundant group of reef animals, the gastropods. The humpbacked conch (Gibberulus gibberulus gibbosus), inhabiting subtidal zones of the Great Barrier Reef, was chosen as a model because vigorous jumping, causing increased oxygen uptake (ṀO2 ), can be induced by exposure to odour from a predatory cone snail (Conus marmoreus). We investigated the effect of present-day ambient (417-454 µatm) and projected-future (955-987 µatm) PCO2 on resting (ṀO2 , rest) and maximum (ṀO2 , max) ṀO2 , as well as ṀO2 during hypoxia and critical oxygen tension (PO2 , crit), in snails kept at present-day ambient (28°C) or projected-future temperature (33°C). ṀO2 , rest and ṀO2 , max were measured both at the acclimation temperature and during an acute 5°C increase. Jumping caused a 4- to 6-fold increase in ṀO2 , and ṀO2 , max increased with temperature so that absolute aerobic scope was maintained even at 38°C, although factorial scope was reduced. The humpbacked conch has a high hypoxia tolerance with a PO2 , crit of 2.5 kPa at 28°C and 3.5 kPa at 33°C. There was no effect of elevated CO2 on respiratory performance at any temperature. Long-term temperature records and our field measurements suggest that habitat temperature rarely exceeds 32.6°C during the summer, indicating that these snails have aerobic capacity in excess of current and future needs. © 2015. Published by The Company of Biologists Ltd.

  10. Testing a bioenergetics-based habitat choice model: bluegill (Lepomis macrochirus) responses to food availability and temperature

    USGS Publications Warehouse

    2011-01-01

    Using an automated shuttlebox system, we conducted patch choice experiments with 32, 8–12 g bluegill sunfish (Lepomis macrochirus) to test a behavioral energetics hypothesis of habitat choice. When patch temperature and food levels were held constant within patches but different between patches, we expected bluegill to choose patches that maximized growth based on the bioenergetic integration of food and temperature as predicted by a bioenergetics model. Alternative hypotheses were that bluegill may choose patches based only on food (optimal foraging) or temperature (behavioral thermoregulation). The behavioral energetics hypothesis was not a good predictor of short-term (from minutes to weeks) patch choice by bluegill; the behavioral thermoregulation hypothesis was the best predictor. In the short-term, food and temperature appeared to affect patch choice hierarchically; temperature was more important, although food can alter temperature preference during feeding periods. Over a 19-d experiment, mean temperatures occupied by fish offered low rations did decline as predicted by the behavioral energetics hypothesis, but the decline was less than 1.0 °C as opposed to a possible 5 °C decline. A short-term, bioenergetic response to food and temperature may be precluded by physiological costs of acclimation not considered explicitly in the behavioral energetics hypothesis.

  11. Influence of cortisol on the attachment and metamorphosis of larval Utterbackia imbecillis on bluegill sunfish (Lepomis macrochirus).

    PubMed

    Dubansky, Benjamin; Whitaker, Brian; Galvez, Fernando

    2011-04-01

    The larvae of unionid freshwater mussels (i.e., glochidia) undergo a parasitic stage requiring their attachment to the external epithelia of fish hosts, where they metamorphose into free-living juveniles. We describe the physiological effects in bluegill sunfish (Lepomis macrochirus) of infection with glochidia from the paper pondshell (Utterbackia imbecillis). Glochidia accumulation on bluegill increased dramatically at concentrations of 2000 glochidia liter(-1) and above, reaching a maximum attachment density of about 30 glochidia g(-1) fish at 4000 glochidia liter(-1). Plasma cortisol was the most sensitive indicator of biological effect to glochidial exposure, increasing significantly in hosts exposed to 2000 glochidia liter(-1) or greater. Glochidia were 31% more likely to undergo successful juvenile metamorphosis when attached to bluegill with elevated plasma cortisol, largely due to the enhanced survivorship of these larvae during the first 48 h after infection. We tested the hypothesis that glochidial attachment and juvenile metamorphosis were stimulated directly by plasma cortisol in fish hosts. Bluegill were given an intraperitoneal injection of cortisol, then infected with 1000 glochidia liter(-1) at 48 h after hormone supplementation. Cortisol-injected fish had a 42% increase in the number of attached glochidia g(-1) fish and a 28% increase in larval metamorphosis compared to sham-injected and control fish. We provide evidence that cortisol enhances glochidial metamorphosis on hosts by improving the retention of attached glochidia. This study gives insights into the influence of host physiology on glochidial attachment and juvenile mussel transformation.

  12. Exploring spatial distributions of larval yellow perch Perca flavescens, bluegill Lepomis macrochirus and their prey in relation to wind.

    PubMed

    Kaemingk, M A; Jolley, J C; Willis, D W; Graeb, B D S

    2011-04-01

    The objectives of the present study were to determine if spatial differences existed between zooplankton, larval yellow perch Perca flavescens and bluegill Lepomis macrochirus (<13 mm total length, L(T)) in Pelican Lake (332 ha), NE, U.S.A. It was hypothesized that wind could act as a transport mechanism for larval fishes in this shallow lake, because strong winds are common at this geographic location. Potential spatial differences were explored, relating to zooplankton densities, size structure and densities of larval P. flavescens and L. macrochirus. Density differences (east v. west side of the lake) were detected for small- (two occasions), medium- (two occasions) and large-sized (one occasion) L. macrochirus larvae. No density differences were detected for small P. flavescens larvae; however, densities of medium- and large-sized P. flavescens were each higher on the west side of the lake on two occasions. There was no evidence that larval P. flavescens and L. macrochirus distributions were related to wind because they were not associated with large wind events. Likewise, large wind event days did not result in any detectable spatial differences of larval P. flavescens and L. macrochirus densities. There appeared to be no spatial mismatch between larval densities and associated prey in the years examined. Thus, wind was not apparently an influential mechanism for zooplankton and larval P. flavescens and L. macrochirus transport within Pelican Lake, and spatial differences in density may instead be related to vegetation and habitat complexities or spawning locations within this shallow lake.

  13. Median fin function during the escape response of bluegill sunfish (Lepomis macrochirus). I: Fin-ray orientation and movement.

    PubMed

    Chadwell, Brad A; Standen, Emily M; Lauder, George V; Ashley-Ross, Miriam A

    2012-08-15

    The fast-start escape response is critically important to avoid predation, and axial movements driving it have been studied intensively. Large median dorsal and anal fins located near the tail have been hypothesized to increase acceleration away from the threat, yet the contribution of flexible median fins remains undescribed. To investigate the role of median fins, C-start escape responses of bluegill sunfish (Lepomis macrochirus) were recorded by three high-speed, high-resolution cameras at 500 frames s(-1) and the 3-D kinematics of individual dorsal and anal fin rays were analyzed. Movement and orientation of the fin rays relative to the body axis were calculated throughout the duration of the C-start. We found that: (1) timing and magnitude of angular displacement varied among fin rays based on position within the fin and (2) kinematic patterns support the prediction that fin rays are actively resisting hydrodynamic forces and transmitting momentum into the water. We suggest that regions within the fins have different roles. Anterior regions of the fins are rapidly elevated to increase the volume of water that the fish may interact with and transmit force into, thus generating greater total momentum. The movement pattern of all the fin rays creates traveling waves that move posteriorly along the length of the fin, moving water as they do so. Flexible posterior regions ultimately act to accelerate this water towards the tail, potentially interacting with vortices generated by the caudal fin during the C-start. Despite their simple appearance, median fins are highly complex and versatile control surfaces that modulate locomotor performance.

  14. Constraints on starting and stopping: behavior compensates for reduced pectoral fin area during braking of the bluegill sunfish Lepomis macrochirus.

    PubMed

    Higham, Timothy E; Malas, Brett; Jayne, Bruce C; Lauder, George V

    2005-12-01

    Many natural animal movements involve accelerating from a standstill and then stopping. Obstacles in natural environments often limit the straight-line distance available for movement, and decreased braking ability theoretically can limit speed for short distances. Consequently, braking ability can be important for avoiding collisions with obstacles and exploiting resources effectively in complex environments. A presumed morphological correlate of improved braking performance in fish is increased pectoral fin area, because most fish protract these structures as they decelerate. However, the kinematics and modulation of velocity during starting and stopping are poorly understood for most species of fish as well as most species of animals. Thus, for bluegill sunfish Lepomis macrochirus with complete and partially ablated pectoral fins (35% original fin area), we analyzed high speed video recordings (200 images s-1) of predatory attacks with a start and stop in a short, standardized distance (40 cm). We quantified body displacement, velocity, acceleration, deceleration and several fin angle variables during each feeding. Unexpectedly, several variables including maximum velocity and maximum deceleration (grand means 72 cm s-1 and -512 cm s-2, respectively) did not change significantly with reduced pectoral fin area. The average values of braking movements of the median and caudal fins did increase with decreased pectoral fin area but lacked statistically significant differences. The primary mechanism of attaining similar braking performance with decreased area of the pectoral fins was that they were protracted significantly more (mean difference=42 degrees) and with a significantly faster average velocity of protraction. Thus, pectoral fin area appears unlikely to be the primary constraint on braking performance for this particular task.

  15. Trace element content of fish feed and bluegill sunfish (Lepomis macrochirus) from aquaculture and wild source in Missouri.

    PubMed

    Ikem, Abua; Egilla, Jonathan

    2008-09-15

    Trace element content of fish feed and bluegill sunfish muscles (Lepomis macrochirus) from aquaculture and natural pond in Missouri were determined using the inductively coupled-plasma optical emission spectrometer (ICP-OES) and the direct mercury analyzer (DMA). Dietary intake rates of trace elements were estimated. Dogfish muscle (DORM-2) and lobster hepatopancreas (TORT-2) reference standards were used in trace element recovery and method validations. The average elemental concentrations (mg/kg diet, dry wt.) of fish feed were: As 1.81, Cd 2.37, Co 0.10, Cr 1.42, Cu 8.0, Fe 404, Mn 35.9, Ni 0.51, Pb 9.16, Se 1.71, Sn 20.7, V 0.09, Zn 118 and Hg 0.07. The mean elemental concentrations (μg/kg wet wt.) in bluegill muscles from both aquaculture and wild (in parenthesis) sources were: As 0.36 (0.06), Cd 0.28 (0.01), Co 0.0 (0.0), Cr 0.52 (0.05), Cu 0.38 (0.18), Fe 17.5 (2.43), Mn 0.18 (0.24), Ni 0.18 (0.04), Pb 1.03 (0.04), Se 0.34 (0.30), Sn 0.66 (0.42), V 0.02 (0.01), Zn 6.97 (9.13) and Hg 0.06 (0.24). Kruskal-Wallis chi square indicated significant differences in As, Cd, Co, Cr, Cu, Fe, Ni, Pb, Sn, V, Zn and Hg (P<0.001), Se (P<0.01) and Mn (P<0.05) across the sampling locations. Dietary intake rates, estimated from weekly consumption of 228g of aquaculture and wild bluegills, posed no health risks for approximately 85% of all samples.

  16. Biodiversity data mining from Argus-eyed citizens: the first illegal introduction record of Lepomis macrochirus macrochirus Rafinesque, 1819 in Japan based on Twitter information.

    PubMed

    Miyazaki, Yusuke; Teramura, Akinori; Senou, Hiroshi

    2016-01-01

    An apparent illegal introduction of Lepomis macrochirus macrochirus from Yokohama City, Kanagawa Prefecture, Japan, is reported based on a juvenile specimen and a photograph of two adults collected on 14 June 2015 and deposited in the Kangawa Prefectural Museum of Natural History. The specimens and photographs were initially reported on the internet-based social networking site, Twitter. Two specimens of Carassius auratus, including an aquarium form, were also reported at the same locality and date, suggesting that the illegal introductions originated from an aquarium release. Our report demonstrates an example of web data mining in the discipline of Citizen Science.

  17. Biodiversity data mining from Argus-eyed citizens: the first illegal introduction record of Lepomis macrochirus macrochirus Rafinesque, 1819 in Japan based on Twitter information

    PubMed Central

    Miyazaki, Yusuke; Teramura, Akinori; Senou, Hiroshi

    2016-01-01

    Abstract An apparent illegal introduction of Lepomis macrochirus macrochirus from Yokohama City, Kanagawa Prefecture, Japan, is reported based on a juvenile specimen and a photograph of two adults collected on 14 June 2015 and deposited in the Kangawa Prefectural Museum of Natural History. The specimens and photographs were initially reported on the internet-based social networking site, Twitter. Two specimens of Carassius auratus, including an aquarium form, were also reported at the same locality and date, suggesting that the illegal introductions originated from an aquarium release. Our report demonstrates an example of web data mining in the discipline of Citizen Science. PMID:27110154

  18. Urbanization and the Level of Microplastic Ingestion by Fish: A Comparison of Freshwater Sunfish (Centrarchidae) from the Brazos River watershed, and Pinfish (Sparidae), from the Brazos Estuary and Inshore Marine Sites, Texas, USA

    NASA Astrophysics Data System (ADS)

    Rieper, K. B.; Peters, C. A.; Bratton, S. P.

    2016-02-01

    While previous research has documented ingestion of macro- and microplastics by aquatic fauna in both freshwater and marine ecosystems, relatively little is known of the environmental and ecological factors influencing the entry and diffusion of plastics and artificial polymers into aquatic foodwebs. Microplastics are defined as 50 μm to 5 mm in length. This study utilized stomach content analysis to compare the level of microplastic artificial polymer ingestion for fish collected from the Brazos River watershed, Brazos estuary, and inshore coastal waters of Texas, USA, in areas with varying levels of urbanization. We collected 318 bluegill (Lepomis macrochirus) and 118 longear sunfish (Lepomis megalotis) at 14 freshwater locales, and 11 samples of 298 pinfish (Lagodon rhomboides) at 6 saltwater locales. Sunfish averaged 12.6 cm in length, and pinfish averaged 14.9 cm. Sunfish averaged .807 microplastics per fish, and pinfish averaged 1.09. The maximum percentage for pinfish with microplastics present per sample (frequency) was 77%, compared to 75% for sunfish. Mean frequencies per sample were also similar: 45% for sunfish and 47% for pinfish. The Brazos River collections, however, had a greater percentage with frequencies of <.30 (42%) for sunfish, versus 9% for pinfish. Sample sites in the center of urbanized zones, including downtown Waco and Galveston, TX, had the greatest frequencies of ingestion, while sites upstream of Waco, TX, had the least. For pinfish, the mean stomach weight per sample was significantly positively correlated (p=.01) to both the percent of individuals ingesting microplastics (cc=.742) and the mean number of plastic particles ingested per fish (cc=.697). The majority of the microplastics were thread shaped, with blue and grey the dominant colors. Comparison with presence of natural food items suggests microplastic ingestion is predominantly incidental for these sentinel fish species.

  19. Morphology and molecules reveal the alien Posthodiplostomum centrarchi Hoffman, 1958 as the third species of Posthodiplostomum Dubois, 1936 (Digenea: Diplostomidae) in Europe.

    PubMed

    Stoyanov, Borislav; Georgieva, Simona; Pankov, Plamen; Kudlai, Olena; Kostadinova, Aneta; Georgiev, Boyko B

    2017-01-01

    Metacercariae of two species of Posthodiplostomum Dubois, 1936 (Digenea: Diplostomidae) were subjected to morphological and molecular studies: P. brevicaudatum (von Nordmann, 1832) from Gasterosteus aculeatus (L.) (Gasterosteiformes: Gasterosteidae), Bulgaria (morphology, cox1 and ITS1-5.8S-ITS2) and Perca fluviatilis L. (Perciformes: Percidae), Czech Republic (morphology, cox1, ITS1-5.8S-ITS2 and 28S); and P. centrarchi Hoffman, 1958 from Lepomis gibbosus (L.) (Perciformes: Centrarchidae), Bulgaria (morphology, cox1 and ITS1-5.8S-ITS2) and Slovakia (cox1 and ITS1-5.8S-ITS2). In addition, cercariae of P. cuticola (von Nordmann, 1832) from Planorbis planorbis (L.) (Mollusca: Planorbidae), Lithuania (morphology and cox1) and metacercariae of Ornithodiplostomum scardinii (Schulman in Dubinin, 1952) from Scardinius erythrophthalmus (L.) (Cypriniformes: Cyprinidae), Czech Republic, were examined (morphology, cox1, ITS1-5.8S-ITS2 and 28S). These represent the first molecular data for species of Posthodiplostomum and Ornithodiplostomum Dubois, 1936 from the Palaearctic. Phylogenetic analyses based on cox1 and ITS1-5.8S-ITS2, using O. scardinii as the outgroup and including the three newly-sequenced Posthodiplostomum spp. from Europe and eight published unidentified (presumably species-level) lineages of Posthodiplostomum from Canada confirmed the distinct status of the three European species (contrary to the generally accepted opinion that only P. brevicaudatum and P. cuticola occur in the Palaearctic). The subspecies Posthodiplostomum minimum centrarchi Hoffmann, 1958, originally described from North America, is elevated to the species level as Posthodiplostomum centrarchi Hoffman, 1958. The undescribed "Posthodiplostomum sp. 3" of Locke et al. (2010) from centrarchid fishes in Canada has identical sequences with the European isolates of P. centrarchi and is recognised as belonging to the same species. The latter parasite, occurring in the alien pumpkinseed sunfish

  20. Life-history variability of non-native centrarchids in regulated river systems of the lower River Guadiana drainage (south-west Iberian Peninsula).

    PubMed

    Ribeiro, F; Collares-Pereira, M J

    2010-02-01

    Life-history variability of two non-native centrarchids, pumpkinseed Lepomis gibbosus and largemouth bass Micropterus salmoides, was evaluated in three stream stretches of the lower River Guadiana drainage (south-west Iberian Peninsula) with different degrees of regulated flows. Abundance, condition and population structure differed among populations for both species, but invasion success was lower in the least regulated river. Lepomis gibbosus were abundant and had multiple age classes in the three river sites, whereas M. salmoides were less abundant and mainly represented by young-of-the-year fish. Juvenile growth in L. gibbosus was similar in all three populations, though longevity was slightly greater in the population from the River Guadiana mainstream. Lepomis gibbosus exhibited a long reproductive season, but the duration of season, size at maturity and reproductive effort varied among populations. The life-history differences found demonstrate the importance of species adaptation to local conditions which might favour their invasion success. Lepomis gibbosus were more adaptable and resilient to local conditions, whereas M. salmoides seemed dependent on reservoirs and large rivers for maintenance of riverine populations.

  1. Histopathologic evaluation of postmortem autolytic changes in bluegill (Lepomis macrohirus) and crappie (Pomoxis anularis) at varied time intervals and storage temperatures

    PubMed Central

    George, Jami; Van Wettere, Arnaud J.; Michaels, Blayk B.; Crain, Debbi

    2016-01-01

    Information is lacking on preserving fish carcasses to minimize postmortem autolysis artifacts when a necropsy cannot be performed immediately. The purpose of this study was to qualitatively identify and score histologic postmortem changes in two species of freshwater fish (bluegill—Lepomis macrochirus; crappie—Pomoxis annularis), at varied time intervals and storage temperatures, to assess the histologic quality of collected samples. A pooled sample of 36 mix sex individuals of healthy bluegill and crappie were euthanized, stored either at room temperature, refrigerated at 4 °C, or frozen at −20 °C, and then necropsied at 0, 4, 24, and 48 h intervals. Histologic specimens were evaluated by light microscopy. Data showed that immediate harvesting of fresh samples provides the best quality and refrigeration would be the preferred method of storage if sample collection had to be delayed for up to 24 h. When sample collection must be delayed more than 24 h, the preferred method of storage to minimize autolysis artifacts is freezing if evaluation of the gastrointestinal tract is most important, or refrigeration if gill histology is most important. The gill arch, intestinal tract, followed by the liver and kidney were the most sensitive organs to autolysis. PMID:27114885

  2. Fin ray sensation participates in the generation of normal fin movement in the hovering behavior of the bluegill sunfish (Lepomis macrochirus).

    PubMed

    Williams, Richard; Hale, Melina E

    2015-11-01

    For many fish species, the pectoral fins serve as important propulsors and stabilizers and are precisely controlled. Although it has been shown that mechanosensory feedback from the fin ray afferent nerves provides information on ray bending and position, the effects of this feedback on fin movement are not known. In other taxa, including insects and mammals, sensory feedback from the limbs has been shown to be important for control of limb-based behaviors and we hypothesized that this is also the case for the fishes. In this study, we examined the impact of the loss of sensory feedback from the pectoral fins on movement kinematics during hover behavior. Research was performed with bluegill sunfish (Lepomis macrochirus), a model for understanding the biomechanics of swimming and for bio-inspired design of engineered fins. The bluegill beats its pectoral fins rhythmically, and in coordination with pelvic and median fin movement, to maintain a stationary position while hovering. Bilateral deafferentation of the fin rays results in a splay-finned posture where fins beat regularly but at a higher frequency and without adducting fully against the side of the body. For unilateral transections, more irregular changes in fin movements were recorded. These data indicate that sensory feedback from the fin rays and membrane is important for generating normal hover movements but is not necessary for generating rhythmic fin movement. © 2015. Published by The Company of Biologists Ltd.

  3. Cadmium, metal-binding proteins, and growth in bluegill (Lepomis macrochirus

    USGS Publications Warehouse

    Cope, W. Gregory; Wiener, James G.; Steingraeber, Mark T.; Atchison, Gary J.

    1994-01-01

    We exposed juvenile bluegill (Lepomis macrochirus) to ~1000 mg∙L−1 of continuously suspended river sediment in a 28-d test with six treatments (randomized block with one sediment-free control and five sediments ranging from 1.3 to 21.4 μg Cd∙g dry weight−1). Each treatment had three replicates, each with 25 fish. Growth was reduced by exposure to suspended sediment, probably due to physical effects of sediment on feeding and to toxicity in the treatment with the greatest concentrations of metals. Mean whole-body concentrations of cadmium (0.04–0.14 μg∙g wet weight−1) were correlated with cadmium concentration in filtered water (8–72 ng∙L−1), suspended sediment (0.61–16.8 μg∙L−1), and bulk sediment. The concentration of hepatic nonthionein cytosolic cadmium (cadmium not bound by metal-binding proteins, MBP) in fish exposed to the two most contaminated sediments exceeded that in controls. The mean concentration of hepatic MBP was correlated with cadmium concentration in filtered water, suspended sediment, bulk sediment, and whole fish. Whole-body cadmium concentration was the most sensitive indicator of cadmium exposure, with lowest observed effect concentrations of 1.9 μg Cd∙L−1 for suspended sediment and 13 ng Cd∙L−1 for filtered water. Sediment-associated cadmium was less available than waterborne cadmium for uptake by fish.

  4. Sucking while swimming: evaluating the effects of ram speed on suction generation in bluegill sunfish Lepomis macrochirus using digital particle image velocimetry.

    PubMed

    Higham, Timothy E; Day, Steven W; Wainwright, Peter C

    2005-07-01

    It is well established that suction feeding fish use a variable amount of swimming (ram) during prey capture. However, the fluid mechanical effects of ram on suction feeding are not well established. In this study we quantified the effects of ram on the maximum fluid speed of the water entering the mouth during feeding as well as the spatial patterns of flow entering the mouth of suction-feeding bluegill sunfish Lepomis macrochirus. Using Digital Particle Image Velocimetry (DPIV) and high-speed video, we observed the flow in front of the mouth of three fish using a vertical laser sheet positioned on the mid-sagittal plane of the fish. From this we quantified the maximum fluid speed (measured at a distance in front of the mouth equal to one half of the maximum mouth diameter), the degree of focusing of water flow entering the mouth, and the shape of the ingested volume of water. Ram speed in 41 feeding sequences, measured at the time of maximum gape, ranged between 0 and 25 cm s(-1), and the ratio of ram speed to fluid speed ranged from 0.1% to 19.1%. In a regression ram speed did not significantly affect peak fluid speed, but with an increase in ram speed the degree of focusing of water entering the mouth increased significantly, and the shape of the ingested volume of water became more elongate and narrow. The implications of these findings are that (1) suction feeders that employ ram of between 0% and 20% of fluid speed sacrifice little in terms of the fluid speeds they generate and (2) ram speed enhances the total body closing speed of the predator.

  5. Spatial and temporal patterns of water flow generated by suction-feeding bluegill sunfish Lepomis macrochirus resolved by Particle Image Velocimetry.

    PubMed

    Day, Steven W; Higham, Timothy E; Cheer, Angela Y; Wainwright, Peter C

    2005-07-01

    The suction-feeding fish generates a flow field external to its head in order to draw prey into the mouth. To date there are very few empirical measurements that characterize the fluid mechanics of suction feeding, particularly the temporal and spatial patterns of water velocity in front of the fish. To characterize the flow in front of suction-feeding bluegill sunfish Lepomis macrochirus, measurements with high spatial (<1 mm) and temporal (500 Hz) resolution were taken using Particle Image Velocimetry (PIV). In an analysis separate from the PIV, high-speed video sequences were used for a novel method of visually tracking every seed particle for the duration of each feeding in order to determine directly the total parcel of water that the fish ingests. PIV measurements and particle tracking show that water is drawn from all around the mouth. Fluid velocity decreases rapidly with distance from the mouth and is only significant (>5% of speed at the mouth) within roughly 1 mouth diameter of the fish. Suction feeders gain little in terms of extending this flow field by even substantial increases in the fluid speed at the mouth opening. Instead, the chief advantage of increased flow speed at the mouth may be the increased magnitude of generated forces within the space very close to the mouth. After scaling of the velocity field based on size of the mouth opening and the measured fluid speed at a fixed position, the measured velocity profiles for all feedings are very similar to one another, so that a functional relationship for the magnitude of fluid speed as a function of distance from the predator mouth is presented and shown to be accurate over the range of kinematic variables tested. This relationship describes the velocity field both along the centerline of the fish and along transects lying at an angle to the centerline within both the mid-sagittal and frontal planes. Comparison of the time-resolved fluid velocity measurements to gape kinematics demonstrate that

  6. Autogenic-allogenic status affects interpond community similarity and species area relationship of macroparasites in the bluegill sunfish, Lepomis macrochirus, from a series of freshwater ponds in the Piedmont area of North Carolina.

    PubMed

    Fellis, K Joel; Esch, Gerald W

    2005-08-01

    The effects of autogenic-allogenic status on the species-area relationship and the relationship between geographic distance and intercommunity dissimilarity were investigated in macroparasite communities of the bluegill sunfish Lepomis macrochirus. Rank correlation analyses were used to examine the relationship between pond surface area and species richness of all species collectively and of autogenic species and allogenic species separately. A positive relationship was found for allogenic species, whereas there was no association for all species, nor was there an association when the study was restricted to autogenic species. Mantel tests were used to determine the relationship between geographic distance and community dissimilarity for all species and for autogenic and allogenic species independently. Total community dissimilarity and allogenic dissimilarity were found to be influenced by geographic distance, whereas autogenic dissimilarity was random with regard to interpond distances. These findings serve to illustrate the importance of the autogenic-allogenic dichotomy and demonstrate that dispersal ability can influence commonly observed ecological patterns.

  7. Lower Mississippi River Environmental Program. Report 7. An Ecological Evaluation of Five Secondary Channel Habitats in the Lower Mississippi River

    DTIC Science & Technology

    1987-12-01

    BG Thomas A. Sands, CE. Accec,. o !, For NTIS CRA&I DTIC I.A : UJ ! i;I- o ,: - Li-< [ K 4 L, D-t ,I., CONTENTS Page PREFACE...Centrarchidae - sunfishes Bluegill (Lepomis macrochirus) * Longear sunfish (Lepomis megalotis ) Largemouth bass (Micropterus salmoides) * White crappie (Pomoxis...4 V) ct, N\\ m 0o $4 - -H 󈧬 0.0 -4 ) Ln rt - -t Ct, -It 00 00 00m Cu 4UC 0~ mI -4) 0 4- 4)3 Cu-q cn I-4- -. 0 N- o P ’ C,, 0’ n c o Ŕ 4.)4JC 01-4

  8. Water-quality assessment of the Albemarle-Pamlico Drainage Basin, North Carolina and Virginia; organochlorine compounds in Asiatic clam (Corbicula fluminea) soft tissues and whole redbrest sunfish (Lepomis auritus) 1992-93

    USGS Publications Warehouse

    Smith, K.E.; Ruhl, P.M.

    1996-01-01

    The analysis of potential contaminants in biological tissues is an important part of many water-quality assessment programs, including the National Water-Quality Assessment (NAWQA) Program. Tissue analyses often are used to provide information about (1) direct threats to ecosystem integrity, and (2) the occurrence and distribution of potential contaminants in the environment. During 1992-93, Asiatic clam (Corbicula fluminea) soft tissues and whole redbreast sunfish (Lepomis auritus) samples were collected and analyzed to obtain information about the occurrence and distribution of organochlorine compounds in the Albemarle-Pamlico drainage Basin of North Carolina and Virginia. The investigation was conducted as part of the NAWQA Program. Relatively few organochlorine compounds were detected and of the compounds detected, all were detected in relatively low concentrations. The organochlorine compounds detected were p,p'-DDD, p,p'-DDE, p,p'-DDT, dieldrin, trans-nonachlor, PCB's, and toxaphene. Multiple compounds were detected at 16 of 19 sites sampled. Compared to Asiatic clams, redbreast sunfish appear to be better bioindicators of organochlorine contamination in aquatic systems. Except for one detection of toxaphene, pesticide concentrations are well below the National Academy of Sciences and National Academy of Engineering (NAS/NAE) guidelines for the protection of fish-eating wildlife.

  9. Water-quality assessment of the Albemarle-Pamlico drainage basin, North Carolina and Virginia; trace elements in Asiatic clam (Corbicula fluminea) soft tissues and redbreast sunfish (Lepomis auritus) livers, 1992-93

    USGS Publications Warehouse

    Ruhl, P.M.; Smith, K.E.

    1996-01-01

    The analysis of potential contaminants in biological tissues is an important part of many water-quality assessment programs, including the National Water-Quality Assessment (NAWQA) Program. Tissue analyses often are used to provide information about (1) direct threats to ecosystem integrity, and (2) the occurrence and distribution of potential contaminants in the environment. During 1992-93, trace elements in Asiatic clam (Corbicula fluminea) soft tissues and redbreast sunfish (Lepomis auritus) livers were analyzed to obtain information about the occurrence and distribution of trace element contaminants in the Albemarle-Pamlico Drainage Basin of North Carolina and Virginia. The investigation was conducted as part of the NAWQA Program. All but 3 of the 22 trace elements that were analyzed were detected. Although all 10 of the U.S. Environmental Protection Agency (U.S. EPA) priority pollutants were detected in the tissues sampled, they were present in relatively low concentrations. Concentrations of U.S. EPA priority pollutants in Asiatic clams collected in the Albemarle-Pamlico Drainage Basin are similar to concentrations observed in other NAWQA study units in the southeastern United States. Mercury (a U.S. EPA priority pollutant) was widely detected, being present in 29 of 30 tissue samples, but concentrations did not exceed the FDA action level for mercury of a risk-based screening value for the general public. Mercury concentrations in Asiatic clams were similar to concentrations in other NAWQA study areas in the Southeast.

  10. 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.

  11. Fishery survey and related limnological conditions of Williams Lake, Hubbard County, Minnesota

    USGS Publications Warehouse

    Taylor, W.W.; LaBaugh, J.W.; Freeberg, M.H.; Dowling, D.C.

    1985-01-01

    Bluegill (Lepomis macrochirus), pumpkinseed sunfish (Lepomis gibbosus), largemouth bass (Micropterus salmoides), yellow perch (Perca flavescens) rock bass (Amploplites rupestris), black crappie (Pomozis nigromaculatus), and northern pike (Esox lucius) were found in Williams Lake, Hubbard County, Minnesota, during a fishery survey of the lake in late August 1982. The most abundant fish were the bluegills. These fish live in the large littoral zone of the lake; this zone underlies 55% of the surface area of the lake. The most ubiquitous benthic invertebrate in the littoral zone (amphipods) and the most abundant benthic invertebrate (chironomid larvae) were major food sources for the bluegill. Other organisms found in the stomach contents of fish collected in this survey were zooplankton, gastropods, Diptera larvae, odonates, terrestrial insects, and other fish. Daphnia were the only zooplankters of a diverse plankton community that were found in stomach contents. The abundance of fish other than bluegill was typical for a system in which northern pike is the major predator.

  12. [Micropterus salmoides (Pisces: Centrarchidae) reproduction in the Gustavo Diaz Ordaz reservoir, Sinaloa, México].

    PubMed

    Beltrán Alvarez, Rigoberto; Sánchez Palacios, Jesús; Ramírez Lozano, Juan Pedro; Ortega Salas, Adolfo-Armando

    2013-09-01

    Micropterus salmoides is an important fish species for sport fishing activities, condition that has promoted its introduction to different reservoirs in Mexico and worldwide. With the aim to improve its fisheries management, this research dealt with some reproductive aspects of this species in the Gustavo Diaz Ordaz reservoir, where it was studied from August 2008 through March 2011. To this end, we obtained 938 specimens, with gillnets of different sizes, to determine their total length (Lt, in cm), weight (Pt, in g), sex, gonadosomatic index, condition factor, fecundity and size at first maturity. Lt and Pt ranged from 15.9 to 63 cm (37.4 +/- 78.0) and 57 to 4431 g (731.7 +/- 619.0), respectively. The Pt-Lt relationship showed a positive allometric growth, with no significant difference between males and females (F = 0.9955, p = 0.3187). The male: female ratio obtained was 1:0.83. Mass spawning lasted from December to April. Size at first maturity was 33.7 cm and average fecundity was 32294 +/- 12878.7 oocytes/female. The gonadosomatic index was low from May through November, and increased between January and March. The condition factor was high before the spawning season and decreased after the reproductive period. We recommend a fishing ban from January to March, and to allow the capture size between 33 and 40 cm.

  13. Interspecific relationships and the evolution of sexual dimorphism in pygmy sunfishes (Centrarchidae: Elassoma).

    PubMed

    Sandel, Michael; Rohde, Fritz C; Harris, Phillip M

    2014-08-01

    The genus Elassoma represents a small but unique component of the aquatic biodiversity hotspot in southeastern North America. We present the first phylogeny of the seven described species, corroborated by sequence data from mitochondrial and nuclear protein coding genes. This analysis reveals a Coastal Plain clade sister to the geographically isolated, and federally protected, Elassoma alabamae. The Coastal Plain clade contains the widespread E. zonatum, which is sister to a clade primarily restricted to lowland Neogene subprovinces. We analyzed morphometric data in a phylogenetic context to illustrate the evolution of sexual shape dimorphism within the genus. Sixteen univariate and three multivariate traits were tested for significant sexual dimorphism for each species, and relative transformation rates were inferred from the time tree. A simple index of interspecific sexual dimorphism revealed greater disparity among sympatric species comparisons than among allopatric comparisons. Results implicate geology as a primary factor influencing ecological diversification, and sexual selection as a mechanism reinforcing reproductive isolation in areas of secondary contact. We discuss putative roles of geological history and sexual selection in the generation and maintenance of the aquatic biodiversity gradient in southeastern North America.

  14. Streamwise vortices destabilize swimming bluegill sunfish (Lepomis macrochirus).

    PubMed

    Maia, Anabela; Sheltzer, Alex P; Tytell, Eric D

    2015-03-01

    In their natural environment, fish must swim stably through unsteady flows and vortices, including vertical vortices, typically shed by posts in a flow, horizontal cross-flow vortices, often produced by a step or a waterfall in a stream, and streamwise vortices, where the axis of rotation is aligned with the direction of the flow. Streamwise vortices are commonly shed by bluff bodies in streams and by ships' propellers and axial turbines, but we know little about their effects on fish. Here, we describe how bluegill sunfish use more energy and are destabilized more often in flow with strong streamwise vorticity. The vortices were created inside a sealed flow tank by an array of four turbines with similar diameter to the experimental fish. We measured oxygen consumption for seven sunfish swimming at 1.5 body lengths (BL) s(-1) with the turbines rotating at 2 Hz and with the turbines off (control). Simultaneously, we filmed the fish ventrally and recorded the fraction of time spent maneuvering side-to-side and accelerating forward. Separately, we also recorded lateral and ventral video for a combination of swimming speeds (0.5, 1.5 and 2.5 BL s(-1)) and turbine speeds (0, 1, 2 and 3 Hz), immediately after turning the turbines on and 10 min later to test for accommodation. Bluegill sunfish are negatively affected by streamwise vorticity. Spills (loss of heading), maneuvers and accelerations were more frequent when the turbines were on than in the control treatment. These unsteady behaviors, particularly acceleration, correlated with an increase in oxygen consumption in the vortex flow. Bluegill sunfish are generally fast to recover from roll perturbations and do so by moving their pectoral fins. The frequency of spills decreased after the turbines had run for 10 min, but was still markedly higher than in the control, showing that fish partially adapt to streamwise vorticity, but not completely. Coping with streamwise vorticity may be an important energetic cost for stream fishes or migratory fishes.

  15. Some effects of Heptachlor on bluegills (Lepomis macrochirus)

    USGS Publications Warehouse

    Andrews, Austin K.; Stebbings, Bruce E.; Van Valin, Charles C.

    1966-01-01

    In complementary studies of the chronic effects of heptachlor on bluegills, four similar earthen ponds were treated once with different concentrations of heptachlor, and the fish in six plastic pools were routinely fed different levels of heptachlor. A fifth pond and two plastic pools were used as controls. Higher dosages resulted in higher concentrations of heptachlor residues, more pronounced tissue pathology, and higher mortality in the test fish. Heptachlor reached a maximum in the pond fish about 3 days after treatment, and could no longer be found in the fish or mud after 56 days. The fish fed continuous levels of heptachlor developed their highest residues at 56 days. Invertebrate populations in the two higher treatment level ponds were eliminated. Lesser effects appeared in the two lower concentrations. At the termination of the experiment, invertebrate populations in the treated ponds and the control were not significantly different, and had achieved or surpassed pretreatment levels. Degenerative liver lesions became pronounced in fish from the two higher exposure ponds, but a heavy infestation of trematode metacercariae in the fish of all the test ponds, except the control, clouded further interpretation of histopathological examinations. Pathology results from the fish in the feeding test, although inconclusive, tended to support the trends which were developing in the contact test. There was an inverse proportional relationship between growth of fish in the feeding test and the amount of heptachlor introduced. The control group showed the highest growth rate, and the groups with progressively higher intake of heptachlor had progressively lower growth rates.

  16. First record of Neoergasilus japonicus (Poecilostomatoida: Ergasilidae), a parasitic copepod new to the Laurentian Great Lakes

    USGS Publications Warehouse

    Hudson, Patrick L.; Bowen, Charles A.

    2002-01-01

    The parasitic copepod Neoergasilus japonicus, native to eastern Asia, was first collected from 4 species of fish (fathead minnow, Pimephales promelas; largemouth bass, Micropterus salmoides; pumpkinseed sunfish, Lepomis gibbosus; and yellow perch, Perca flavescens) in July 1994 in Saginaw Bay, Lake Huron, Michigan. Further sampling in the bay in 2001 revealed infections on 7 additional species (bluegill, Lepomis macrochirus; carp, Cyprinus carpio; channel catfish, Ictalurus punctatus; goldfish, Carassius auratus; green sunfish, Lepomis cyanellus; rock bass, Ambloplites rupestris; and smallmouth bass, Micropterus dolomieu). An additional 21 species examined in 2001 were devoid of the parasite. A limited collection of fish from Lake Superior (n = 8) and Lake Michigan (n = 46) in 1994 showed no infection. Neoergasilus japonicus is most frequently found attached to the dorsal fin and, in decreasing frequency, on the anal, tail, pelvic, and pectoral fins. Prevalence generally ranged from 15 to 70 and intensity from 1 to 10. The greatest number of copepods on a single host was 44. The copepod Neoergasilus japonicus appears to disperse over long distances rather quickly, spreading across Europe in 20 yr and then moving on to North America over a span of 10 yr. Its main vehicle of transport and introduction into the Great Lakes is probably exotic fish hosts associated with the fish-culture industry.

  17. Actinobdella inequinnulata (Annelida: Hirudinida:Rhynchobdellida:Glossiphoniidae) from White Crappie, Pomoxis annularis (Perciformes: Centrarchidae), in Arkansas, USA

    EPA Science Inventory

    One of 4 (25%) white crappie, Pomoxis annularis from the Ouachita River, Dallas County, Arkansas, was found to be infested with 8 glossiphoniid leeches, Actinobdella inequiannulata Moore, 1901. Leeches were removed from within the oeprculum on gills and gill arches. This leech i...

  18. Actinobdella inequinnulata (Annelida: Hirudinida:Rhynchobdellida:Glossiphoniidae) from White Crappie, Pomoxis annularis (Perciformes: Centrarchidae), in Arkansas, USA

    EPA Science Inventory

    One of 4 (25%) white crappie, Pomoxis annularis from the Ouachita River, Dallas County, Arkansas, was found to be infested with 8 glossiphoniid leeches, Actinobdella inequiannulata Moore, 1901. Leeches were removed from within the oeprculum on gills and gill arches. This leech i...

  19. Diversity within the Redeye Bass, Micropterus coosae (Perciformes: Centrarchidae) species group, with descriptions of four new species.

    PubMed

    Baker, Winston H; Blanton, Rebecca E; Johnston, Carol E

    2013-01-01

    The Redeye Bass, Micropterus coosae, was described from the Mobile River basin, Chattahoochee, and Savannah rivers in Alabama and Georgia, USA, by Hubbs and Bailey (1940). At that time the authors recognized significant variation in the Black Warrior River population, and noted that with further study this form may be recognized as a separate taxon. An examination of variation in morphology and mitochondrial DNA supported this observation, and highlighted additional species-level variation, resulting in descriptions of a total of four new species: Micropterus cahabae, new sp., restricted to the Cahaba River system; Micropterus tallapoosae, new sp., restricted to the Tallapoosa River system; Micropterus warriorensis, new sp., from the Black Warrior River system; and Micropterus chattahoochae, new sp., from the Chattahoochee River system. Micropterus coosae is restricted to the Coosa River system. The new species differ from each other and from M. coosae by a combination of pigmentation and scale count characteristics, development of the tooth patch, and divergence within the ND2 gene. While two of these species are relatively common in upland streams within their ranges, M. warriorensis, M. cahabae and M. chattahoochae are uncommon and may warrant protection.

  20. Chromium accumulation in three species of central Florida centrarchids

    SciTech Connect

    Campbell, K.R. |

    1995-02-01

    Stormwater ponds are required in Central Florida when land is developed to treat the resulting stormwater. The St. Johns River Water Management District, the agency that regulates stormwater discharges in Central Florida, frequently approves plans that create habitat for fish and wildlife by planting desirable wetland and aquatic vegetation in the littoral zones of stormwater ponds to compensate for the loss of wetlands. The various species of fish that inhabit stormwater ponds serve as a food source to wildlife, especially wading birds. The objective of this study was to determine if fish that live in stormwater treatment ponds in Orlando, Florida contained significant concentrations of chromium. In order to determine if there were differences in chromium concentrations in fish with different foraging strategies, three species of sunfish (Centrarchidae) with substantially different foraging strategies were selected for this study: largemouth bass (Micropterus salmoides), a predator; redear sunfish (Lepomis microlophus), a bottom feeder; and bluegill sunfish (Lepomis macrochirus), an omnivore. Many researchers have shown that large quantities of chromium are found in urban runoff. Chromium sources are largely associates with the operation of motor vehicles. Several investigators have determined that chromium from urban runoff concentrates in the sediment of stormwater ponds. Sediments represent the most concentrated physical pool of metals in aquatic environments, and they are ingested by many types of aquatic organisms. Most fish are capable of accumulating heavy metals from their diet and from water through their gills. 17 refs., 1 fig., 3 tabs.

  1. A molecular genetic examination of the mating system of pumpkinseed sunfish reveals high pay-offs for specialized sneakers.

    PubMed

    Rios-Cardenas, Oscar; Webster, Michael S

    2008-05-01

    Intrasexual variation in reproductive behaviour and morphology are common in nature. Often, such variation appears to result from conditional strategies in which some individuals (e.g. younger males or those in poor condition) adopt a low pay-off phenotype as a 'best of a bad job'. Alternatively, reproductive polymorphisms can be maintained by balancing selection, with male phenotypes having equal fitnesses at equilibrium, but examples from nature are rare. Many species of sunfish (genus Lepomis) are thought to have alternative male reproductive behaviours, but most empirical work has focused on the bluegill sunfish and the mating systems of other sunfish remain poorly understood. We studied a population of pumpkinseed sunfish (Lepomis gibbosus) in upstate New York. Field observations confirm the existence of two male reproductive strategies: 'parentals' were relatively old and large males that maintained nests, and 'sneakers' were relatively young and small males that fertilize eggs by darting into nests of parentals during spawning. The sneaker and parental male strategies appear to be distinct life-history trajectories. Sneaker males represented 39% of the males observed spawning, and sneakers intruded on 43% of all mating attempts. Microsatellite analyses revealed that sneaker males fertilized an average of 15% of the eggs within a nest. This level of paternity by sneaker males appears to be higher than seen in most other fishes, and preliminary analyses suggest that the two male reproductive strategies are maintained as a balanced polymorphism.

  2. BEHAVIORAL AND PHYSIOLOGICAL RESPONSES OF DAPHNIA MAGNA, CHLORELLA VULGARIS, LEPOMIS MACROCHIRUS, AND VIBRIO FISCHERI TO TOLUENE

    EPA Science Inventory

    The research presented here is a continuation of work designed to further the science of available and developing online toxicity monitors(OTMs) and how they may be most effectively deployed in a watershed management plan and/or water quality early warning system. Source waters o...

  3. Determination of Ten Perfluorinated Compounds in Bluegill Sunfish (Lepomis macrochirus) Fillets

    EPA Science Inventory

    Limited information is known about the environmental distributions of the perfluorinated compounds (PFCs) such as perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA), in part due to a lack of well characterized analytical methods that can be used to accurately mea...

  4. Determination of Ten Perfluorinated Compounds in Bluegill Sunfish (Lepomis macrochirus) Fillets

    EPA Science Inventory

    Limited information is known about the environmental distributions of the perfluorinated compounds (PFCs) such as perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA), in part due to a lack of well characterized analytical methods that can be used to accurately mea...

  5. Motility, ATP levels and metabolic enzyme activity of sperm from bluegill (Lepomis macrochirus).

    PubMed

    Burness, Gary; Moyes, Christopher D; Montgomerie, Robert

    2005-01-01

    Male bluegill displays one of two life history tactics. Some males (termed "parentals") delay reproduction until ca. 7 years of age, at which time they build nests and actively courts females. Others mature precociously (sneakers) and obtain fertilizations by cuckolding parental males. In the current study, we studied the relations among sperm motility, ATP levels, and metabolic enzyme activity in parental and sneaker bluegill. In both reproductive tactics, sperm swimming speed and ATP levels declined in parallel over the first 60 s of motility. Although sneaker sperm initially had higher ATP levels than parental sperm, by approximately 30 s postactivation, no differences existed between tactics. No differences were noted between tactics in swimming speed, percent motility, or the activities of key metabolic enzymes, although sperm from parentals had a higher ratio of creatine phosphokinase (CPK) to citrate synthase (CS). In both tactics, with increasing CPK and CS activity, sperm ATP levels increased at 20 s postactivation, suggesting that capacities for phosphocreatine hydrolysis and aerobic metabolism may influence interindividual variation in rates of ATP depletion. Nonetheless, there was no relation between sperm ATP levels and either swimming speed or percent of sperm that were motile. This suggests that interindividual variation in ATP levels may not be the primary determinant of variation in sperm swimming performance in bluegill.

  6. BEHAVIORAL AND PHYSIOLOGICAL RESPONSES OF DAPHNIA MAGNA, CHLORELLA VULGARIS, CORBICULA FLUMINEA, LEPOMIS MACROCHIRUS, AND VIBRO FISCHERI

    EPA Science Inventory

    The research presented here is a continuation of work designed to further the science of available and developing continuous, automated water quality monitors and how they may be most effectively deployed in a watershed management plan and/or water quality early warning system (W...

  7. The effects of acute temperature change on swimming performance in bluegill sunfish Lepomis macrochirus.

    PubMed

    Jones, Emily A; Jong, Arianne S; Ellerby, David J

    2008-05-01

    Many fish change gait within their aerobically supported range of swimming speeds. The effects of acute temperature change on this type of locomotor behavior are poorly understood. Bluegill sunfish swim in the labriform mode at low speeds and switch to undulatory swimming as their swimming speed increases. Maximum aerobic swimming speed (U(max)), labriform-undulatory gait transition speed (U(trans)) and the relationships between fin beat frequency and speed were measured at 14, 18, 22, 26 and 30 degrees C in bluegill acclimated to 22 degrees C. At temperatures below the acclimation temperature (T(a)), U(max), U(trans) and the caudal and pectoral fin beat frequencies at these speeds were reduced relative to the acclimation level. At temperatures above T(a) there was no change in these variables relative to the acclimation level. Supplementation of oxygen levels at 30 degrees C had no effect on swimming performance. The mechanical power output of the abductor superficialis, a pectoral fin abductor muscle, was measured in vitro at the same temperatures used for the swimming experiments. At and below T(a), maximal power output was produced at a cycle frequency approximately matching the in vivo pectoral fin beat frequency. At temperatures above T(a) muscle power output and cycle frequency could be increased above the in vivo levels at U(trans). Our data suggest that the factors triggering the labriform-undulatory gait transition change with temperature. Muscle mechanical performance limited labriform swimming speed at T(a) and below, but other mechanical or energetic factors limited labriform swimming speed at temperatures above T(a).

  8. BEHAVIORAL AND PHYSIOLOGICAL RESPONSES OF DAPHNIA MAGNA, CHLORELLA VULGARIS, LEPOMIS MACROCHIRUS, AND VIBRIO FISCHERI TO TOLUENE

    EPA Science Inventory

    The research presented here is a continuation of work designed to further the science of available and developing online toxicity monitors(OTMs) and how they may be most effectively deployed in a watershed management plan and/or water quality early warning system. Source waters o...

  9. BEHAVIORAL AND PHYSIOLOGICAL RESPONSES OF DAPHNIA MAGNA, CHLORELLA VULGARIS, CORBICULA FLUMINEA, LEPOMIS MACROCHIRUS, AND VIBRO FISCHERI

    EPA Science Inventory

    The research presented here is a continuation of work designed to further the science of available and developing continuous, automated water quality monitors and how they may be most effectively deployed in a watershed management plan and/or water quality early warning system (W...

  10. Acute and Behavioral Effects of Hydrazine on ’Lepomis macrochirus’

    DTIC Science & Technology

    1978-06-01

    Geiger for their support. 1 INTRODUCTION Hydrazine, monomethyihydrazine (MMH), and unsymmetrical dimethyihydrazine (UDMH) are used as fuels in many Air...water used was a 1 : 1 dilution of tap (hard) water with in-house distilled water. The tap water was allowed to stand in plastic carboys for at least...two weeks before the supernate was siphoned off. The precipitate contained iron and other substances. Table 1 depicts the preexposure water quality

  11. Dim light vision--morphological and functional adaptations of the eye of the mormyrid fish, Gnathonemus petersii.

    PubMed

    Landsberger, Meik; von der Emde, Gerhard; Haverkate, Dorothee; Schuster, Stefan; Gentsch, Janina; Ulbricht, Elke; Reichenbach, Andreas; Makarov, Felix; Wagner, Hans-Joachim

    2008-01-01

    The African weakly electric fish Gnathonemus petersii is well known for its electrosensory capabilities. These animals can detect and distinguish objects through active electrolocation in complete darkness. Because of their nocturnal lifestyle, a low contribution of vision for orientation and object detection has been expected. However, as we show in this review, the retina of G. petersii is highly specialized with hundreds of rods and tens of cones grouped together in bundles in a complex way, ensheathed by a tapetum lucidum. The structure of the bundles goes beyond what would be expected if only photon catch was supposed to be increased. During daytime, the structure of these "macro-receptors" changes dramatically depending on retinomotor movements. During the day, the rods and cones are located in different compartments of the bundle, separated by a narrow canal in the form of a "bottle neck". Investigations on cell structure and neurochemistry in the retina indicate a general organization that is simpler in terms of bipolar and ganglion cell diversity than in tetrachromatic species such as goldfish, yet similar in terms of neurochemical differentiation of amacrine cells. In both respects, the inner retina of the elephantnose fish bears the greatest similarity to catfish and some deep-sea fish retinae. Neuronal circuits and bundle structure give hints of possible adaptations for contrast and/or movement detection. Behavioral experiments suggest that, in contrast to the vision specialists Lepomis gibbosus, pattern detection of G. petersii is not affected by higher spatial frequencies. A pattern of low spatial frequencies, however, was equally well detected by G. petersii and L. gibbosus. Optomotor response experiments indicate that motion vision is important for Gnathonemus, narrowing down the search for the functional specialization of the Gnathonemus retina and providing a starting point for work on multisensory integration in these fish.

  12. Urbanization is a major influence on microplastic ingestion by sunfish in the Brazos River Basin, Central Texas, USA.

    PubMed

    Peters, Colleen A; Bratton, Susan P

    2016-03-01

    Microplastics, degraded and weathered polymer-based particles, and manufactured products ranging between 50 and 5000 μm in size, are found within marine, freshwater, and estuarine environments. While numerous peer-reviewed papers have quantified the ingestion of microplastics by marine vertebrates, relatively few studies have focused on microplastic ingestion by freshwater organisms. This study documents microplastic and manufactured fiber ingestion by bluegill (Lepomis macrochirus) and longear (Lepomis megalotis) sunfish (Centrarchidae) from the Brazos River Basin, between Lake Whitney and Marlin, Texas, USA. Fourteen sample sites were studied and categorized into urban, downstream, and upstream areas. A total of 436 sunfish were collected, and 196 (45%) stomachs contained microplastics. Four percent (4%) of items sampled were debris on the macro size scale (i.e. >5 mm) and consisted of masses of plastic, metal, Styrofoam, or fishing material, while 96% of items sampled were in the form of microplastic threads. Fish length was statistically correlated to the number of microplastics detected (p = 0.019). Fish collected from urban sites displayed the highest mean number of microplastics ingested, followed by downstream and upstream sites. Microplastics were associated with the ingestion of other debris items (e.g. sand and wood) and correlated to the ingestion of fish eggs, earthworms, and mollusks, suggesting that sunfish incidentally ingest microplastics during their normal feeding methods. The high frequency of microplastic ingestion suggest that further research is needed to determine the residence time of microplastics within the stomach and gut, potential for food web transfer, and adverse effects on wildlife and ecosystemic health.

  13. Infection levels and seasonality of monogeneans in the largemouth bass Micropterus salmoides (Perciformes: Centrarchidae) from Nuevo León, Mexico.

    PubMed

    Galaviz-Silva, L; Iruegas-Buentello, F J; Escobar-González, B; Molina-Garza, Z J

    2016-11-01

    Largemouth bass, Micropterus salmoides, is a native fish species with special importance for sport fishing competitions in Nuevo León, Mexico. However, no study has investigated the parasitic fauna of M. salmoides, and no reports are available on monogenean parasites in this fish species. Therefore, we described the monogenean parasites of M. salmoides and the effects of season and fish condition factor in five reservoirs: La Boca (LB), El Cuchillo-Solidaridad (CS), Sombreretillo (S), Laguna Salinillas (LS) and Cerro Prieto (CP). The monogeneans infecting M. salmoides were Clavunculus unguis and Acolpenteron ureteroecetes (collected in all localities), as well as Syncleithrium fusiformis, Haplocleidus furcatus, Clavunculus bifurcatus and Urocleidus principalis (CS). Clavunculus unguis had the highest prevalence in fish from all reservoirs. The abundance of monogeneans was generally greater in late spring to autumn than in winter. Although season was not correlated with abundance (r s = 0.0934, P <  0.0154), the months of highest temperature (from May to September) were positively correlated with parasite abundance. A significant association was observed between fish condition factor and the presence of monogeneans (P <  0.05), except for A. ureteroecetes. Our findings include five new geographic records for C. unguis, S. fusiformis, H. furcatus and C. bifurcatus.

  14. High prevalence of buccal ulcerations in largemouth bass, Micropterus salmoides (Centrarchidae) from Michigan inland lakes associated with Myzobdella lugubris Leidy 1851 (Annelida: Hirudinea)

    PubMed Central

    Faisal, M.; Schulz, C.; Eissa, A.; Whelan, G.

    2011-01-01

    Widespread mouth ulcerations were observed in largemouth bass collected from eight inland lakes in the Lower Peninsula of Michigan during the summer months of 2002 and 2003. These ulcerations were associated with, and most likely caused by, leech parasitism. Through the use of morphological dichotomous keys, it was determined that all leeches collected are of one species: Myzobdella lugubris. Among the eight lakes examined, Lake Orion and Devils Lake had the highest prevalence of leech parasitism (34% and 29%, respectively) and mouth ulcerations (53% and 68%, respectively). Statistical analyses demonstrated that leech and ulcer prevalence varied significantly from one lake to the other. Additionally, it was determined that the relationship between the prevalence of ulcers and the prevalence of leech attachment is significant, indicating that leech parasitism is most likely the cause of ulceration. The ulcers exhibited deep hemorrhagic centers and raised irregular edges. Affected areas lost their epithelial lining and submucosa, with masses of bacteria colonizing the damaged tissues. Since largemouth bass is a popular global sportfish and critical to the food web of inland lakes, there are concerns that the presence of leeches, damaged buccal mucosa, and general unsightliness may negatively affect this important sportfishery. PMID:21395209

  15. Biomarker responses in sunfish species and largemouth bass from the Saluda River, South Carolina.

    PubMed

    Mierzejewski, Jessica; Haney, Dennis C; van den Hurk, Peter

    2014-12-01

    The upstate and Piedmont region of South Carolina is a rapidly urbanizing area as a result of a steadily growing population. This increase in population and development has the potential to negatively impact local aquatic systems like the Saluda River due to increased pollution from runoff, and effluents from industrial and wastewater treatment facilities. During the summer months of 2010, 159 fish from the Centrarchidae family (sunfish species (Lepomis) and largemouth bass - Micropterus salmoides) were collected from 13 sites along the Saluda River. A suite of biomarker assays, including ethoxyresosufin-O-deethylase, bile fluorescence, glutathione S-transferase, thiobarbituric acid reactive substances, bile estrogens, acetylcholinesterase inhibition, metallothionein and tissue metal levels were applied to investigate the impacts of diminished water quality on fish health. Results indicate that fish from the Saluda River are responding to contamination in a site specific manner, with up to four significant biomarker responses in the most impacted sites. Sampling sites in the lower portion of the Saluda watershed are less impacted by pollution than the upper and central sections. The observed biomarker responses can be explained by the proximity of urban areas, point sources and general land use, and demonstrate the applicability of biomarkers in environmental biomonitoring programs.

  16. Monogeneans on native and introduced freshwater fishes from Cuba with the description of a new species of Salsuginus Beverley-Burton, 1984 from Limia vittata (Poeciliidae).

    PubMed

    Mendoza-Franco, Edgar F; Vidal-Martínez, V M; Cruz-Quintana, Y; León, F L Prats

    2006-07-01

    During a parasitological survey carried out between March and September 2003 in Cuba, the following monogeneans were found on the gills of freshwater fishes: Salsuginus cubensis n. sp. on the Cuban molly Limia vittata Guichenot (Poeciliidae); Cichlidogyrus sclerosus Paperna & Thurston, 1969 and C. tilapiae Paperna, 1960 on the African cichlid Tilapia rendalli Boulenger (Cichlidae); Haplocleidus dispar Mueller, 1936 and Pterocleidus acer Mueller, 1936 (all Dactylogyridae) on the sunfish Lepomis macrochirus Rafinesque (Centrarchidae) (new geographical records); and Gyrodactylus sp. (Gyrodactylidae) on the biajaca Nandopsis tetracanthus Valenciennes (Cichlidae) (new host and geographical record). Salsuginus cubensis differs from all other species of the genus in the size and morphology of the copulatory complex. The occurrence of C. sclerosus, C. tilapiae, H. dispar and P. acer in their respective hosts is due to the introduction of these hosts to Cuba. A review of the species composition of the Monogenea in native and introduced freshwater fish from Cuba is presented and the zoogeographical distribution of the species found is briefly discussed.

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

    PubMed

    Kraus, Richard T; Jones, R Christian

    2012-05-01

    Submerged aquatic vegetation (SAV) is considered an important habitat for juvenile and small forage fish species, but many long-term recruitment surveys do not effectively monitor fish communities in SAV. To better understand the impact of recent large increases of SAV on the fish community in tidal freshwater reaches of the Potomac River, we compared traditional seine sampling from shore with drop ring sampling of SAV beds (primarily Hydrilla) in a shallow water (depths, <1.5 m) embayment, Gunston Cove. To accomplish this, we developed species-specific catch efficiency values for the seine gear and calculated area-based density in both shoreline and SAV habitats in late summer of three different years (2007, 2008, and 2009). For the dominant species (Fundulus diaphanus, Lepomis macrochirus, Etheostoma olmstedi, Morone americana, Lepomis gibbosus, and Fundulus heteroclitus), density was nearly always higher in SAV, but overall, species richness was highest in shoreline habitats sampled with seines. Although historical monitoring of fish in Gunston Cove (and throughout Chesapeake Bay) is based upon seine sampling (and trawl sampling in deeper areas), the high densities of fish and larger areal extent of SAV indicated that complementary sampling of SAV habitats would produce more accurate trends in abundances of common species. Because drop ring samples cover much less area than seines and may miss rare species, a combination of methods that includes seine sampling is needed for biodiversity assessment. The resurgence of SAV in tidal freshwater signifies improving water quality, and methods we evaluated here support improved inferences about population trends and fish community structure as indicators of ecosystem condition.

  18. Endocrine disruption and altered gonadal development in white perch (Morone americana) from the lower Great Lakes region.

    PubMed Central

    Kavanagh, Richard J; Balch, Gordon C; Kiparissis, Yiannis; Niimi, Arthur J; Sherry, Jim; Tinson, Cheryl; Metcalfe, Chris D

    2004-01-01

    High prevalences of gonadal intersex have been observed in wild fish populations in areas affected by domestic and industrial effluents. For this study, fish were collected in 1998 from the Cootes Paradise region of Hamilton Harbour in western Lake Ontario, Canada, to determine whether gonadal abnormalities, including intersex, were present in young of the year (YOY) fish. No gonadal abnormalities were observed in goldfish (Carassius auratus), common carp (Cyprinus carpio), gizzard shad (Dorosoma cepedianum), brown bullhead (Ictalurus ameiurus), pumpkinseed (Lepomis gibbosus), and bluegill (Lepomis macrochirus). However, intersex gonads were observed in 8 of 16 male white perch (Morone americana) examined in this survey. Subsequently, in 1999 and 2000 white perch estimated to be YOY to approximately 2 years of age were collected from Cootes Paradise and from two other sites in the lower Great Lakes region. Gonadal intersex was observed in male white perch collected from the Bay of Quinte (22-44%) and Lake St. Clair (45%), although the prevalence and the extent of the intersex condition were lower relative to the 83% prevalence in white perch collected in Cootes Paradise. Intersex was not observed in hatchery-reared white perch or in white perch collected from an uncontaminated reference site (i.e., Deal Lake) in the United States. An analysis of plasma collected in the spring of 2002 from male adult white perch in Cootes Paradise revealed high concentrations of vitellogenin, ranging from 49 to 1,711 microg/mL. These observations indicate that male white perch are exposed to estrogenic endocrine-disrupting substances that may be responsible for the induction of gonadal intersex. PMID:15175179

  19. Allometric scaling in centrarchid fish: origins of intra- and inter-specific variation in oxidative and glycolytic enzyme levels in muscle.

    PubMed

    Davies, Rhiannon; Moyes, Christopher D

    2007-11-01

    The influence of body size on metabolic rate, muscle enzyme activities and the underlying patterns of mRNA for these enzymes were explored in an effort to explain the genetic basis of allometric variation in metabolic enzymes. We studied two pairs of sister species of centrarchid fish: black bass (largemouth bass Micropterus salmoides and smallmouth bass Micropterus dolomieui) and sunfish (pumpkinseed Lepomis gibbosus and bluegill Lepomis macrochirus). Our goal was to assess the regulatory basis of both intraspecific and interspecific variation relative to body size, as well as to gain insights into the evolutionary constraints within lineages. Whole animal routine metabolic rate showed scaling coefficients not significantly different from 1, ranging from (+0.87 to +0.96). However, there were significant effects of body size on the specific activities of oxidative and glycolytic enzymes. Mass-specific activity of the oxidative enzyme citrate synthase (CS) scaled negatively with body size in each species, with scaling coefficients ranging from -0.15 to -0.19, whereas the glycolytic enzyme pyruvate kinase (PK) showed positive scaling, with scaling coefficients ranging from +0.08 to +0.23. The ratio of mass-specific enzyme activity in PK to CS increased with body size, whereas the ratio of mRNA transcripts of PK to CS was unaffected, suggesting the enzyme relationships were not due simply to transcriptional regulation of both genes. The mass-dependent differences in PK activities were best explained by transcriptional regulation of the muscle PK gene; PK mRNA was a good predictor of PK specific enzyme activity within species and between species. Conversely, CS mRNA did not correlate with CS specific enzyme activities, suggesting post-transcriptional mechanisms may explain the observed inter-specific and intraspecific differences in oxidative enzymes.

  20. Ionoregulatory Aspects of the Osmorespiratory Compromise during Acute Environmental Hypoxia in 12 Tropical and Temperate Teleosts.

    PubMed

    Robertson, Lisa M; Val, Adalberto Luis; Almeida-Val, Vera F; Wood, Chris M

    2015-01-01

    In the traditional osmorespiratory compromise, as seen in the hypoxia-intolerant freshwater rainbow trout (Oncorhynchus mykiss), the branchial modifications that occur to improve O2 uptake during hypoxia result in unfavorable increases in the fluxes of ions and water. However, at least one hypoxia-tolerant freshwater species, the Amazonian oscar (Astronotus ocellatus), shows exactly the opposite: decreased branchial flux rates of ions, water, and nitrogenous wastes during acute hypoxia. In order to find out whether the two strategies were widespread, we used a standard 2-h normoxia, 2-h hypoxia (20%-30% saturation), 2-h normoxic recovery protocol to survey 10 other phylogenetically diverse tropical and temperate species. Unidirectional influx and efflux rates of Na(+) and net flux rates of K(+), ammonia, and urea-N were measured. The flux reduction strategy was seen only in one additional species, the Amazonian tambaqui (Colossoma macropomum), which is similarly hypoxia tolerant and lives in the same ion-poor waters as the oscar. However, five other species exhibited evidence of the increased flux rates typical of the traditional osmorespiratory compromise in the trout: the rosaceu tetra (Hyphessobrycon bentosi rosaceus), the moenkhausia tetra (Moenkhausia diktyota), the bluegill sunfish (Lepomis macrochirus), the zebra fish (Danio rerio), and the goldfish (Carassius auratus). Four other species exhibited no marked flux changes during hypoxia: the cardinal tetra (Paracheirodon axelrodi), the hemigrammus tetra (Hemigrammus rhodostomus), the pumpkinseed sunfish (Lepomis gibbosus), and the Atlantic killifish (Fundulus heteroclitus). Overall, a diversity of strategies exist; we speculate that these may be linked to differences in habitat and/or lifestyle.

  1. Morphological change and phenotypic plasticity in native and non-native pumpkinseed sunfish in response to competition

    NASA Astrophysics Data System (ADS)

    Yavno, Stan; Rooke, Anna C.; Fox, Michael G.

    2014-06-01

    Non-indigenous species are oftentimes exposed to ecosystems with unfamiliar species, and organisms that exhibit a high degree of phenotypic plasticity may be better able to contend with the novel competitors that they may encounter during range expansion. In this study, differences in morphological plasticity were investigated using young-of-year pumpkinseed sunfish ( Lepomis gibbosus) from native North American and non-native European populations. Two Canadian populations, isolated from bluegill sunfish ( L. macrochirus) since the last glaciation, and two Spanish populations, isolated from bluegill since their introduction in Europe, were reared in a common environment using artificial enclosures. Fish were subjected to allopatric (without bluegill) or sympatric (with bluegill) conditions, and differences in plasticity were tested through a MANOVA of discriminant function scores. All pumpkinseed populations exhibited dietary shifts towards more benthivorous prey when held with bluegill. Differences between North American and European populations were observed in body dimensions, gill raker length and pelvic fin position. Sympatric treatments induced an increase in body width and a decrease in caudal peduncle length in native fish; non-native fish exhibited longer caudal peduncle lengths when held in sympatry with bluegill. Overall, phenotypic plasticity influenced morphological divergence less than genetic factors, regardless of population. Contrary to predictions, pumpkinseeds from Europe exhibited lower levels of phenotypic plasticity than Canadian populations, suggesting that European pumpkinseeds are more canalized than their North American counterparts.

  2. Thermal physiology of native cool-climate, and non-native warm-climate Pumpkinseed sunfish raised in a common environment.

    PubMed

    Rooke, Anna C; Burness, Gary; Fox, Michael G

    2017-02-01

    Contemporary evolution of thermal physiology has the potential to help limit the physiological stress associated with rapidly changing thermal environments; however it is unclear if wild populations can respond quickly enough for such changes to be effective. We used native Canadian Pumpkinseed (Lepomis gibbosus) sunfish, and non-native Pumpkinseed introduced into the milder climate of Spain ~100 years ago, to assess genetic differences in thermal physiology in response to the warmer non-native climate. We compared temperature performance reaction norms of two Canadian and two Spanish Pumpkinseed populations born and raised within a common environment. We found that Canadian Pumpkinseed had higher routine metabolic rates when measured at seasonally high temperatures (15°C in winter, 30°C in summer), and that Spanish Pumpkinseed had higher critical thermal maxima when acclimated to 30°C in the summer. Growth rates were not significantly different among populations, however Canadian Pumpkinseed tended to have faster growth at the warmest temperatures measured (32°C). The observed differences in physiology among Canadian and Spanish populations at the warmest acclimation temperatures are consistent with the introduced populations being better suited to the warmer non-native climate than native populations. The observed differences could be the result of either founder effects, genetic drift, and/or contemporary adaptive evolution in the warmer non-native climate.

  3. An environmental assessment of a small shallow lake (Little Black Lake, MI) threatened by urbanization.

    PubMed

    Steinman, Alan D; Ogdahl, Mary E; Ruetz, Carl R

    2011-02-01

    A limnological survey was conducted of Little Black Lake, MI, and its tributaries during summer 2007. This small, shallow lake is located in a rapidly developing area of west Michigan. As such, our analytical approach and recommendations can serve as a model for other similar systems threatened by urbanization. Soluble reactive phosphorus and nitrate concentrations in both the inflows to (during baseflow) and Little Black Lake itself were low (≤0.007 and ≤270 mg/L, respectively). Nutrient concentrations increased during stormflow conditions, although the magnitude of the increase depended on the nutrient and sampling location. Macrophyte growth was extensive throughout most parts of the lake, with Chara and Potamogeton spp. present in most sites; based on the coefficient of conservatism, plant composition was indicative of good water quality conditions. Chlorophyll a concentration averaged 1.7 μg/L in Little Black Lake, with cryptophytes and cyanobacteria being the most dominant members (by biovolume) of the phytoplankton community. The fish community in Little Black Lake was dominated by bluegill (Lepomis macrochirus) and pumpkinseed (L. gibbosus), with no invasive species observed. Overall, abiotic and biotic conditions indicate that Little Black Lake is in good ecological health despite increasing pressures of urbanization in its watershed. To maintain this status, it is recommended that the local municipalities develop a comprehensive watershed management plan and implement best management practices to limit nonpoint source pollutant loading to Little Black Lake.

  4. Use of fish-otolith-length regressions to infer size of double-crested cormorant prey fish from recovered otoliths in Lake Ontario

    USGS Publications Warehouse

    Ross, Robert M.; Johnson, James H.; Adams, Connie M.

    2005-01-01

    To provide a method for estimating fish size from fish otoliths for forensic applications or other predictive uses, morphometric measurements were obtained from three centrarchid fishes (pumpkinseed [Lepomis gibbosus], rock bass [Ambloplites rupestris], and smallmouth bass [Micropterus dolomieu]), two percids (yellow perch [Perca flavescens] and walleye [Stizostedion vitreum]), and one clupeid (alewife [Alosa pseudoharengus]) from the eastern basin of Lake Ontario. These species are the principal or economically important prey of Double-crested Cormorants (Phalacrocorax auritus), whose diet can be determined from regurgitated digestive pellets containing fish otoliths. A fuller understanding of the ecosystem roles of cormorants requires estimation of prey-fish size, obtainable from regressions of otolith length on fish length. Up to 100 fish of each species were collected from eastern Lake Ontario and measured for total length and otolith length. Least-squares regressions of otolith length on fish length were calculated for all species, covering life-stage ranges of immature fish to large adults near maximum known size. The regressions with 95% confidence intervals may be applicable outside the Lake Ontario ecosystem if used with caution.

  5. Feeding ecology of Brook Silverside, Golden Shiner, and Subyearling Pumpkinseed in a Lake Ontario embayment

    USGS Publications Warehouse

    Johnson, James H.; Chalupnicki, Marc; Abbett, Ross; Diaz, Avriel R; Nack, Christopher C

    2017-01-01

    Fish feeding ecology has been shown to vary over a 24-h period in terms of the prey consumed and feeding intensity. Consequently, in order to best determine the interspecific feeding associations within a fish community, examination of the diet at multiple times over a 24-h period is often necessary. We examined the diel feeding ecology of three fish species that were numerically dominant in a Lake Ontario embayment during summer. The diet of each of the three species, young-of-year Pumpkinseed Lepomis gibbosus, Golden Shiner Notemigonus crysoleucas, and Brook Silverside Labidesthes sicculus, was distinct with no significant overlap in diet composition occurring within any of the 4-h time intervals. The diet composition of each species suggested that Brook Silverside were feeding at the surface (terrestrial invertebrates and aquatic surface dwelling hemipterans), whereas young-of-year Pumpkinseed (amphipods) and Golden Shiner (tipulids) were feeding on different benthic prey. Differences in feeding periodicity were most pronounced for young-of-year Pumpkinseed. Our findings provide valuable insights on interspecific feeding associations among these three fish species during summer in a Lake Ontario embayment.

  6. Assortative mating but no evidence of genetic divergence in a species characterized by a trophic polymorphism.

    PubMed

    Colborne, S F; Garner, S R; Longstaffe, F J; Neff, B D

    2016-03-01

    Disruptive selection is a process that can result in multiple subgroups within a population, which is referred to as diversification. Foraging-related diversification has been described in many taxa, but many questions remain about the contribution of such diversification to reproductive isolation and potentially sympatric speciation. Here, we use stable isotope analysis of diet and morphological analysis of body shape to examine phenotypic divergence between littoral and pelagic foraging ecomorphs in a population of pumpkinseed sunfish (Lepomis gibbosus). We then examine reproductive isolation between ecomorphs by comparing the isotopic compositions of nesting males to eggs from their nests (a proxy for maternal diet) and use nine microsatellite loci to examine genetic divergence between ecomorphs. Our data support the presence of distinct foraging ecomorphs in this population and indicate that there is significant positive assortative mating based on diet. We did not find evidence of genetic divergence between ecomorphs, however, indicating that isolation is either relatively recent or is not strong enough to result in genetic divergence at the microsatellite loci. Based on our findings, pumpkinseed sunfish represent a system in which to further explore the mechanisms by which natural and sexual selection contribute to diversification, prior to the occurrence of sympatric speciation.

  7. Plant-specific expression of antipredator behaviour by larval damselflies.

    PubMed

    Dionne, Michele; Butler, Mari; Folt, Carol

    1990-06-01

    In this study of interactions between larval damselflies (Zygoptera: Coenagrionidae) and pumpkinseed sunfish (Lepomis gibbosus) we focus on the behaviour of the damselfly prey. First we document a prey behaviour in which damselflies use plant stems or leaves to hide from pumpkinseeds. We then test two hypotheses: (1) that damselfly 'hiding' is a specific antipredator behaviour and (2) that 'hiding' occurs more frequently in plant habitats where damselflies experience greater risk of predation. Since plant species growth forms can influence predation risk, our second hypothesis implies that hiding behaviour is conditional upon the type of vegetation providing habitat structure. Conditional expression of antipredator behaviour according to vegetation type may be important in littoral environments, since predator-prey interactions can occur in habitats with a wide range of macrophyte growth forms. The first hypothesis was supported by our findings that damselfly hiding increased in frequency in the presence of pumpkinseeds, that it was related to the frequency of predator approaches, and that its use reduced damselfly predation risk in high risk habitats. The second hypothesis was supported by our results that damselfly hiding rates were greater in the high risk Scirpus habitats than in the lower risk Potamogeton habitats. These results indicate that prey behaviour can influence predator-prey interactions, and that variation in plant growth form can influence prey behaviour, thus contributing to the impact of habitat structure on predator-prey dynamics.

  8. Effects of size on predation risk, behavioural response to fish, and cost of reduced feeding in larval Ischnura verticalis (Coenagrionidae: Odonata).

    PubMed

    Dixon, S M; Baker, R L

    1988-07-01

    We used laboratory studies to examine the role of predation risk and cost of anti-predator behaviour in determining the behavioural response of several larval instars of Ischnura verticalis to a fish predator (Lepomis gibbosus). Smaller larvae were less susceptible to fish predation than larger larvae. Smaller larvae depressed movement to a greater degree in the presence of fish than did larger larvae; large larvae were generally less active than small larvae regardless of fish presence. Reduced feeding resulted in smaller larvae suffering more in terms of reduced growth than did large larvae. In general, our results tend to support the hypothesis that individuals that suffer high costs of anti-predator behaviour but little risk of predation may only exhibit anti-predator behaviours in the presence of predators, whereas individuals with a higher risk of predation and a lower cost of anti-predator behaviour may evolve anti-predator mechanisms that are in effect even in the absence of predators.

  9. Evidence of secondary consumption of invertebrate prey by Double-crested Cormorants

    USGS Publications Warehouse

    Johnson, J.H.; Ross, R.M.; Smith, D.R.

    1997-01-01

    The piscivorous nature of the Double-crested Cormorant (Phalacrocorax auritus) is well documented. However, many researchers who have used regurgitated pellets to describe the diet of cormorants report that invertebrates compose a small but consistent portion of the diet. We examined the hypothesis that invertebrates found in pellets are primarily the result of secondary consumption. We used odds ratio analysis to examine associations in 2,846 individual pellets between the presence of specific invertebrate prey and the presence of fish species known to consume those invertebrate taxa. Significant (P < 0.05) relationships occurred between gastropods and pumpkinseed (Lepomis gibbosus) and ictalurids, and between decapods and rock bass (Ambloplites rupestris) and smallmouth bass (Micropterus dolomieu). Significant (P < 0.05) relationships were also found between pelecypods and pumpkinseed and ictalurids. We suggest that the invertebrate prey we observed in pellets were present in the digestive tracts of fish that were consumed by Double-crested Cormorants and hence represent secondary consumption by cormorants. We conclude that consumption of invertebrates by Double-crested Cormorants may be overestimated in the literature in instances where the diet was described using pellets.

  10. Fish assemblage structure and habitat associations in a large western river system

    USGS Publications Warehouse

    Smith, C.D.; Quist, Michael; Hardy, R. S.

    2016-01-01

    Longitudinal gradients of fish assemblage and habitat structure were investigated in the Kootenai River of northern Idaho. A total of 43 500-m river reaches was sampled repeatedly with several techniques (boat-mounted electrofishing, hoop nets and benthic trawls) in the summers of 2012 and 2013. Differences in habitat and fish assemblage structure were apparent along the longitudinal gradient of the Kootenai River. Habitat characteristics (e.g. depth, substrate composition and water velocity) were related to fish assemblage structure in three different geomorphic river sections. Upper river sections were characterized by native salmonids (e.g. mountain whitefish Prosopium williamsoni), whereas native cyprinids (peamouth Mylocheilus caurinus, northern pikeminnow Ptychocheilus oregonensis) and non-native fishes (pumpkinseed Lepomis gibbosus, yellow perch Perca flavescens) were common in the downstream section. Overall, a general pattern of species addition from upstream to downstream sections was discovered and is likely related to increased habitat complexity and additions of non-native species in downstream sections. Assemblage structure of the upper sections were similar, but were both dissimilar to the lower section of the Kootenai River. Species-specific hurdle regressions indicated the relationships among habitat characteristics and the predicted probability of occurrence and relative abundance varied by species. Understanding fish assemblage structure in relation to habitat could improve conservation efforts of rare fishes and improve management of coldwater river systems.

  11. Comparative accumulation efficiency of [sup 109]cadmium from natural food (Hyalella azteca) and artificial diet by rainbow trout (Oncorhynchus mykiss)

    SciTech Connect

    Harrison, S.E. ); Curtis, P.J. )

    1992-11-01

    Bioaccumulation models have been proposed to predict the accumulation of chemicals throughout aquatic food-chains. The efficiency with which organisms at each trophic level absorb these substances from their diet is an important component of such models. Metal absorption from food is typically estimated by applying metal salts surficially to commercial fish diets. However, this method may not provide an accurate estimate of in situ accumulation because the efficiency of absorption of metals applied surficially to commercial diets may differ from that of metals absorbed through the food chain. For example, both sunfish (Lepomis gibbosus) and plaice (Pleuronectes platessa) accumulated [sup 65]zinc applied surficially to foods more efficiently than [sup 65]zinc incorporated into live foods. There have apparently been no similar comparisons made for cadmium using fish. Furthermore, few studies have fitted data to exponential equations to provide estimates of the absorption efficiency coefficient (E) and the excretion coefficient (k[sub 2]) for cadmium. We report here the results of direct comparisons of cadmium absorption from commercial trout diet surficially-contaminated with [sup 109]Cd and from natural food (the amphipod Hyalella azteca) cultured in [sup 109]Cd-contaminated microcosms. We calculated absorption efficiency and excretion coefficients for cadmium by monitoring [sup 109]Cd accumulation and excretion in rainbow trout fingerlings fed on the two diets. 19 refs., 2 figs., 1 tab.

  12. Assessment of tolerant sunfish populations (Lepomis sp.) inhabiting selenium-laden coal ash effluents. 1. Hematological and population level assessment.

    PubMed

    Lohner, T W; Reash, R J; Willet, V E; Rose, L A

    2001-11-01

    Sunfish were collected from coal ash effluent-receiving streams and Ohio River watershed reference sites to assess the effects of exposure to low-level selenium concentrations. Selenium, copper, and arsenic concentrations were statistically higher in tissue samples from exposed fish than in reference fish. Leukopenia, lymphocytosis, and neutropenia were evident in exposed fish and were indicative of metal exposure and effect. White blood cell counts and percent lymphocyte values were significantly correlated with liver selenium concentrations. Plasma protein levels were significantly lower in exposed fish than in fish from the Ohio River, indicating that exposed fish may have been nutritionally stressed. Condition factors for fish from the ash pond-receiving streams were the same as, or lower than, those of fish from the reference sites. There was no evidence that the growth rate of fish in the receiving streams differed from that of fish in the reference streams. Despite liver selenium concentrations which exceeded reported toxicity thresholds and evidence of significant hematological changes, there were no significant differences in fish condition factors, liver-somatic indices, or length-weight regressions related to selenium.

  13. Growth, survival, and fatty acid composition of coppernose bluegill (Lepomis macrochirus subspecies) offered different winter feeding regimes

    USDA-ARS?s Scientific Manuscript database

    Winter fish losses are routinely reported by Arkansas sportfish producers in the spring. Juvenile centrarchid species (less than 7.6 cm) are quite susceptible to harsh winter conditions. While some of these winter fish losses can be attributed to predation by fish eating birds and water quality fact...

  14. BEHAVIORAL AND PHYSIOLOGICAL RESPONSES OF DAPHNIA MAGNA, CHLORELLA VULGARIS, CORBICULA FLUMINEA, AND LEPOMIS MACROCHIRUS TO COPPER AND CYANIDE

    EPA Science Inventory

    The research presented here was designed to further the science of available and developing continuous, automated water quality monitors and how they may be most effectively deployed in a watershed management plan and/or water quality early warning system (WQEWS). Source waters ...

  15. Caudal fin shape modulation and control during acceleration, braking and backing maneuvers in bluegill sunfish, Lepomis macrochirus.

    PubMed

    Flammang, B E; Lauder, G V

    2009-01-01

    Evolutionary patterns of intrinsic caudal musculature in ray-finned fishes show that fine control of the dorsal lobe of the tail evolved first, followed by the ability to control the ventral lobe. This progression of increasing differentiation of musculature suggests specialization of caudal muscle roles. Fine control of fin elements is probably responsible for the range of fin conformations observed during different maneuvering behaviors. Here, we examine the kinematics of the caudal fin and the motor activity of the intrinsic caudal musculature during kick-and-glide, braking and backing maneuvers, and compare these data with our previous work on the function of the caudal fin during steady swimming. Kick-and-glide maneuvers consisted of large-amplitude, rapid lateral excursion of the tail fin, followed by forward movement of the fish with the caudal fin rays adducted to reduce surface area and with the tail held in line with the body. Just before the kick, the flexors dorsalis and ventralis, hypochordal longitudinalis, infracarinalis and supracarinalis showed strong activity. During braking, the dorsal and ventral lobes of the tail moved in opposite directions, forming an ;S'-shape, accompanied by strong activity in the interradialis muscles. During backing up, the ventral lobe initiated a dorsally directed wave along the distal edge of the caudal fin. The relative timing of the intrinsic caudal muscles varied between maneuvers, and their activation was independent of the activity of the red muscle of the axial myomeres in the caudal region. There was no coupling of muscle activity duration and electromyographic burst intensity in the intrinsic caudal muscles during maneuvers, as was observed in previous work on steady swimming. Principal-component analysis produced four components that cumulatively explained 73.6% of the variance and segregated kick-and-glide, braking and backing maneuvers from each other and from steady swimming. The activity patterns of the intrinsic caudal muscles during maneuvering suggest motor control independent from myotomal musculature, and specialization of individual muscles for specific kinematic roles.

  16. BEHAVIORAL AND PHYSIOLOGICAL RESPONSES OF DAPHNIA MAGNA, CHLORELLA VULGARIS, CORBICULA FLUMINEA, AND LEPOMIS MACROCHIRUS TO COPPER AND CYANIDE

    EPA Science Inventory

    The research presented here was designed to further the science of available and developing continuous, automated water quality monitors and how they may be most effectively deployed in a watershed management plan and/or water quality early warning system (WQEWS). Source waters ...

  17. Do laboratory species protect endangered species? Interspecies variation in responses to 17β-estradiol, a model endocrine active compound.

    PubMed

    Jorgenson, Z G; Buhl, K; Bartell, S E; Schoenfuss, H L

    2015-01-01

    Although the effects of estrogens on model laboratory species are well documented, their utility as surrogates for other species, including those listed as endangered, are less clear. Traditionally, conservation policies are evaluated based on model organism responses but are intended to protect all species in an environment. We tested the hypothesis that the endangered Rio Grande silvery minnow (Hybognathus amarus) is more vulnerable to endocrine disruption-as assessed through its larval predator-escape performance, survival, juvenile sex ratios, and whole-body vitellogenin concentration-than the commonly used toxicological model species fathead minnow (Pimephales promelas) and the bluegill sunfish (Lepomis macrochirus). Fish were exposed concurrently for 21 days to the model endocrine active compound (EAC) 17ß-estradiol (E2) at 10 ng E2/L and 30 ng E2/L in a flow-through system using reconstituted water that simulated the physicochemical conditions of the Middle Rio Grande in New Mexico, USA. No significant differences were observed between the fathead and silvery minnow in larval predator-escape response or juvenile sex ratio. Rio Grande silvery minnow survival decreased significantly at day 14 compared with the other two species; by day 21, both cyprinid species (silvery minnow and fathead minnow) exhibited a significant decrease in survival compared with bluegill sunfish, a member of the family Centrarchidae. Male Rio Grande silvery minnow showed a significant increase in whole-body vitellogenin concentration in the 10 ng/L treatment, whereas fathead minnow and bluegill sunfish showed no significant increases in vitellogenin concentrations across treatments. Our study showed response differences to estrogen exposures between the two cyprinid species and further divergence in responses between the families Cyprinidae and Centrarchidae. These results suggest that commonly used laboratory model organisms may be less sensitive to EACs than the endangered Rio

  18. Do laboratory species protect endangered species? Interspecies variation in responses to 17β-estradiol, a model endocrine active compound

    USGS Publications Warehouse

    Jorgenson, Zachary G.; Buhl, Kevin J.; Bartell, Stephen E.; Schoenfuss, Heiko L.

    2015-01-01

    Although the effects of estrogens on model laboratory species are well documented, their utility as surrogates for other species, including those listed as endangered, are less clear. Traditionally, conservation policies are evaluated based on model organism responses but are intended to protect all species in an environment. We tested the hypothesis that the endangered Rio Grande silvery minnow (Hybognathus amarus) is more vulnerable to endocrine disruption—as assessed through its larval predator-escape performance, survival, juvenile sex ratios, and whole-body vitellogenin concentration—than the commonly used toxicological model species fathead minnow (Pimephales promelas) and the bluegill sunfish (Lepomis macrochirus). Fish were exposed concurrently for 21 days to the model endocrine active compound (EAC) 17ß-estradiol (E2) at 10 ng E2/L and 30 ng E2/L in a flow-through system using reconstituted water that simulated the physicochemical conditions of the Middle Rio Grande in New Mexico, USA. No significant differences were observed between the fathead and silvery minnow in larval predator-escape response or juvenile sex ratio. Rio Grande silvery minnow survival decreased significantly at day 14 compared with the other two species; by day 21, both cyprinid species (silvery minnow and fathead minnow) exhibited a significant decrease in survival compared with bluegill sunfish, a member of the family Centrarchidae. Male Rio Grande silvery minnow showed a significant increase in whole-body vitellogenin concentration in the 10 ng/L treatment, whereas fathead minnow and bluegill sunfish showed no significant increases in vitellogenin concentrations across treatments. Our study showed response differences to estrogen exposures between the two cyprinid species and further divergence in responses between the families Cyprinidae and Centrarchidae. These results suggest that commonly used laboratory model organisms may be less sensitive to EACs than the endangered

  19. Lack of CYP1A responsiveness in species inhabiting chronically contaminated habitats: two varieties of resistance?

    PubMed

    Brammell, Ben F; Price, David J; Birge, Wesley J; Elskus, Adria A

    2013-03-01

    Organisms chronically exposed to organic pollutants such as polychlorinated biphenyls (PCBs) can develop resistance to these chemicals, a condition associated with reduced inducibility of the biomarker enzyme cytochrome P450 1A (CYP1A). This study addresses the CYP1A response of members of the families Ictaluridae and Centrarchidae, two fish families found throughout much of the United States. We measured CYP1A expression, PCB body burdens, and conducted CYP1A challenge experiments in species from these families residing in the Town Branch/Mud River system (Logan County, KY, USA), a stream system historically contaminated with high levels of PCBs. Despite PCB concentrations in muscle tissue typically associated with elevated CYP1A (16.7 to 75.2μgPCB/g wet edible flesh), resident fish in the contaminated Town Branch/Mud River sites (yellow bullhead [Ameiurus natalis], green sunfish [Lepomis cyanellus], and spotted bass [Micropterus punctulatus]) had hepatic CYP1A activity levels similar to, rather than higher than, those in reference fish, suggesting reduced sensitivity to CYP1A induction. Lack of CYP1A expression following direct contaminant exposure has often been associated with resistance to those contaminants. To determine if CYP1A in resident populations was resistant to induction by PCBs, we exposed resident fish to a single, intraperitoneal injection with a potent CYP1A inducer, 3,4,3',4'-tetrachlorobiphenyl (PCB 77). PCB 77 treatment significantly induced hepatic CYP1A activity and protein in yellow bullhead from reference, but not contaminated, sites and had no effect on CYP1A in green sunfish from either site. The low CYP1A expression levels in resident fish with elevated PCB body burdens, together with the failure of PCB injection to induce CYP1A in certain populations, indicate an acclimatory CYP1A response in yellow bullheads and likely an inherently resistant CYP1A in green sunfish. This work demonstrates for the first time acclimation of CYP1A to

  20. Factors affecting food chain transfer of mercury in the vicinity of the Nyanza site, Sudbury River, Massachusetts

    USGS Publications Warehouse

    Haines, T.A.; May, T.W.; Finlayson, R.T.; Mierzykowski, S.E.

    2003-01-01

    The influence of the Nyanza Chemical Waste Dump Superfund Site on the Sudbury River, Massachusetts, was assessed by analysis of sediment, fish prey organisms, and predator fish from four locations in the river system. Whitehall Reservoir is an impoundment upstream of the site, and Reservoir #2 is an impoundment downstream of the site. Cedar Street is a flowing reach upstream of the site, and Sherman Bridge is a flowing reach downstream of the site. Collections of material for analysis were made three times, in May, July, and October. Sediment was analyzed for acid-volatile sulfide (AVS), simultaneously-extracted (SEM) metals (As, Cd, Cr, Hg, Pb, Sb, Zn), and total recoverable Hg. The dominant predatory fish species collected at all sites, largemouth bass (Micropterus salmoides), was analyzed for the same suite of metals as sediment. Analysis of stomach contents of bass identified small fish (yellow perch Perca flavescens, bluegill Lepomis macrochirus, and pumpkinseed Lepomis gibbosus), crayfish, and dragonfly larvae as the dominant prey organisms. Samples of the prey were collected from the same locations and at the same times as predator fish, and were analyzed for total and methyl mercury. Results of AVS and SEM analyses indicated that sediments were not toxic to aquatic invertebrates at any site. The SEM concentrations of As, Cd, and Cr were significantly higher at Reservoir #2 than at the reference sites, and SEM As and Cd were significantly higher at Sherman Bridge than at Cedar St. Sediment total Hg was elevated only at Reservoir #2. Hg was higher at site-influenced locations in all fish species except brown bullhead (Ameiurus nebulosus). Cd was higher in bluegill, black crappie (Pomoxis nigromaculatus), and brown bullhead, and Cr was higher in largemouth bass fillet samples but not in whole-body samples. There were no seasonal differences in sediment or prey organism metals, but some metals in some fish species did vary over time in an inconsistent manner

  1. Estimating the size of fish consumed by double-crested cormorants: Considerations for better understanding cormorant-fish interactions

    USGS Publications Warehouse

    Johnson, James H.; Ross, Robert M.; McKenna, James E.; Lewis, Graham E.

    2006-01-01

    We measured 926 smallmouth bass (Micropterus dolomieu), 6,935 yellow perch (Perca flavescens), 6,416 rock bass (Ambloplites rupestris), and 4,852 pumpkinseed (Lepomis gibbosus) otoliths recovered from double-crested cormorant (Phalacrocorax auritus) pellets to determine the sizes (total lengths) of these fish consumed by cormorants. Otoliths were recovered from cormorant pellets collected from 1993 to 2002 at six colonies along the eastern Lake Ontario–St. Lawrence River corridor. Otolith –length fish length regressions were used to estimate the length of fish species consumed by cormorants. Only 1.5% of these otoliths had no visible erosion, 33.3% had minor erosion, and 65.2% had moderate erosion. We found that the exclusive use of uneroded otoliths severely limited the sample size available for estimating fish size and likely would cause an overestimation of fish size. Species-specific differences were evident when using erosion criteria to determine fish size and could result in bias when estimating length, especially for species such as smallmouth bass whose otoliths possess a rostrum that is readily eroded. Using a random sample (n = 100) of all intact otoliths recovered in pellets provided a conservative estimate of fish length that was smaller than that derived from uneroded or minimally eroded otoliths. Annual variation in the size of fish consumed by cormorants was more pronounced than seasonal variation for most species. We describe and recommend a new technique that incorporates both chick regurgitant and pellet samples for estimating the size of fish consumed by cormorants.

  2. Biotic and abiotic correlates with black bullhead population characteristics in Nebraska sandhill lakes

    USGS Publications Warehouse

    Phelps, Q.E.; Ward, M.J.; Paukert, C.P.; Chipps, S.R.; Willis, D.W.

    2005-01-01

    We explored relationships among black bullhead (Ameiurus melas) population characteristics and physicochemical attributes in shallow lakes and quantified relationships between population characteristics of black bullhead and sport fishes. Lake characteristics and fisheries survey data were collected from the Sandhills region of northcentral Nebraska from May through June, 1998 and 1999. Relative abundance of black bullheads was inversely related to proportional stock density (r=-0.672, df=15, P=0.004); however, neither relative weight nor growth was significantly (P ??? 0.20) related to black bullhead relative abundance. Population characteristics of common panfish species such as bluegill (Lepomis macrochirus), green sunfish (L. cyanellus), pumpkinseed (L. gibbosus), and yellow perch (Perca flavescens) were not correlated with black bullhead relative abundance or size structure. Rather, proportional stock density (r=0.655, df=10, P=0.029) and growth (r=0.59, df=11, P=0.04) of black bullhead were positively related to relative abundance of largemouth bass (Micropterus salmoides). Similarly, black bullhead relative abundance was inversely related to largemouth bass size structure (r=-0.51, df=14, P= 0.05). Black bullhead mean length at age 3 was positively related to total phosphorous concentration (r=0.65, df=16, P=0.004), and bullhead relative abundance was positively related to shoreline development index (r=0.46, df=22, P=0.03). Population characteristics of black bullhead appeared to have little influence on panfish communities. Rather, black bullhead abundance, predator density, and lake productivity exhibited stronger relationships with black bullhead population characteristics.

  3. Little Galloo Island, Lake Ontario: A review of nine years of double-crested cormorant diet and fish consumption information

    USGS Publications Warehouse

    Johnson, James H.; Ross, Robert M.; McCullough, Russ D.

    2002-01-01

    The diet of double-crested cormorants (Phalacrocorax auritus) on Little Galloo Island (LGI) in the eastern basin of Lake Ontario has been quantified since 1992. Over the past nine years considerable information has been generated on cormorant feeding ecology through the examination of approximately 12,000 pellets collected on LGI, where three distinct cormorant feeding periods, pre-chick, chick, and post-chick, are delineated by differences in diet composition and daily fish consumption. Yellow perch (Perca flavescens) were the major prey during pre-chick and post-chick feeding periods. Alewife (Alosa pseudoharengus), which move inshore to spawn in mid-June, dominated (>60%) cormorant diets during the chick feeding period. Mean daily fish consumption (14.6) during the pre-chick feeding period was significantly greater than during the chick feeding (9.3) or post-chick feeding (8.0) periods. The proportion of smallmouth bass (Micropterus dolomieu) in the diet increased over the season (0.8% to 7.2%), while the size of bass consumed declined (214 mm to 143 mm). Forage fish (mainly alewife, three-spine sticklebacks [Gasterosteus aculeatus] and minnows) comprised 58% of the diet of LGI cormorants, followed by panfish (37%) (yellow perch, pumpkinseed [Lepomis gibbosus], rock bass [Ambloplites rupestris]) and gamefish (5%) (mostly smallmouth bass). On the average LGI cormorants consumed about 32.8 million fish annually, weighing about 1.4 million kilograms. Cormorants from LGI consumed more biomass of smallmouth bass and yellow perch annually than is taken by sport (bass and yellow perch) and commercial (perch) fishermen.

  4. Effects of introduced fishes on wild juvenile coho salmon in three shallow pacific northwest lakes

    USGS Publications Warehouse

    Bonar, Scott A.; Bolding, B.D.; Divens, M.; Meyer, W.

    2005-01-01

    Declines in Pacific salmon Oncorhynchus spp. have been blamed on hydropower, overfishing, ocean conditions, and land use practices; however, less is known about the impacts of introduced fish. Most of the hundreds of lakes and ponds in the Pacific Northwest contain introduced fishes, and many of these water bodies are also important for salmon production, especially of coho salmon O. kisutch. Over 2 years, we examined the predation impacts of 10 common introduced fishes (brown bullhead Ameiurus nebulosus, black crappie Pomoxis nigro-maculatus, bluegill Lepomis macrochirus, golden shiner Notemigonus crysoleucas, green sunfish L. cyanellus, largemouth bass Micropterus salmoides, pumpkinseed L. gibbosus, rainbow trout O. mykiss, warmouth L. gulosus, and yellow perch Perca flavescens) and two native fishes (cutthroat trout O. clarkii and prickly sculpin Cottus asper) on wild juvenile coho salmon in three shallow Pacific Northwest lakes, all located in different watersheds. Of these species, largemouth bass were responsible for an average of 98% of the predation on coho salmon in all lakes, but the total impact to each run varied among lakes and years. Very few coho salmon were eaten by black crappies, brown bullheads, cutthroat trout, prickly sculpin, or yellow perch, whereas other species were not observed to eat coho salmon. Juvenile coho salmon growth in all lakes was higher than in nearby streams. Therefore, food competition between coho salmon and introduced fishes in lakes was probably not limiting coho salmon populations. Largemouth bass are widespread and are present in 85% of lowland warmwater public-access lakes in Washington (n = 421), 84% of those in Oregon (n = 179), and 74% of those in the eight northwesternmost counties in California (n = 19). Future research would help to identify the impact of largemouth bass predation across the region and prioritize lakes where impacts are most severe. Nevertheless, attempts to transplant or increase largemouth bass

  5. Patterns of Parental Investment and Sexual Selection in Teleost Fishes: Do They Support Bateman's Principles?

    PubMed

    Rios-Cardenas, Oscar

    2005-11-01

    Bateman demonstrated differences in variance for fertility and mating success between the sexes, with males usually having a greater variance than females. Thus in general, male reproductive success increases with number of mates acquired. These results have been referred to as "Bateman's principles" and taken together with other parameters (e.g., relative parental investment) have been proposed to estimate a component of sexual selection. For this review I examine patterns of parental care and sexual selection in teleost fishes (substrate brooding and with internal fertilization). I present data for the pumpkinseed sunfish Lepomis gibbosus, in which I estimated cost of paternal care and compared direct measures of the intensity of selection on possible sexually selected traits to measures of sexual selection based on Bateman's principles.Despite high levels of paternal care in substrate brooding fishes, sexual selection tends to act more strongly on males than on females, which suggests that maternal investment is higher than paternal investment and that parental care does not limit the reproductive rate for males. In pumpkinseed sunfish, selection favors parents with high levels of defense that may exclude predators more effectively and, as suggested by Bateman's measures, alternative reproductive strategies may decrease the opportunity for sexual selection within the parental strategy. In teleost fishes with internal fertilization, patterns of parental investment and intensity of sexual selection seem to support Bateman's principles, but further studies using these systems and these measures of selection will improve the understanding of factors affecting the intensity of sexual selection and its relation to mating systems.

  6. Interspecific and environment-induced variation in hypoxia tolerance in sunfish.

    PubMed

    Borowiec, Brittney G; Crans, Kyle D; Khajali, Fariborz; Pranckevicius, Nicole A; Young, Alexander; Scott, Graham R

    2016-08-01

    Hypoxia tolerance is a plastic trait, and can vary between species. We compared hypoxia tolerance (hypoxic loss of equilibrium, LOE, and critical O2 tension, Pcrit) and traits that dictate O2 transport and metabolism in pumpkinseed (Lepomis gibbosus), bluegill (L. macrochirus), and the naturally occurring hybrid in different acclimation environments (wild versus lab-acclimated fish) and at different temperatures. Wild fish generally had lower Pcrit and lower PO2 at LOE in progressive hypoxia than lab-acclimated fish, but time to LOE in sustained hypoxia (PO2 of 2kPa) did not vary between environments. Wild fish also had greater gill surface area and higher haematocrit, suggesting that increased O2 transport capacity underlies the environmental variation in Pcrit. Metabolic (lactate dehydrogenase, LDH; pyruvate kinase, PK; citrate synthase; cytochrome c oxidase) and antioxidant (catalase and superoxide dismutase) enzyme activities varied appreciably between environments. Wild fish had higher protein contents across tissues and higher activities of LDH in heart, PK in brain, and catalase in brain, liver, and skeletal muscle. Otherwise, wild fish had lower activities for most enzymes. Warming temperature from 15 to 25°C increased O2 consumption rate, Pcrit, PO2 at LOE, and haemoglobin-O2 affinity, and decreased time to LOE, but pumpkinseed had ≥2-fold longer time to LOE than bluegill and hybrids across this temperature range. This was associated with higher LDH activities in the heart and muscle, and lower or similar antioxidant enzyme activities in several tissues. However, the greater hypoxia tolerance of pumpkinseed collapsed at 28°C, demonstrating that the interactive effects of hypoxia and warming temperature can differ between species. Overall, distinct mechanisms appear to underpin interspecific and environment-induced variation in hypoxia tolerance in sunfish. Copyright © 2016 Elsevier Inc. All rights reserved.

  7. Invasibility of Mediterranean-Climate Rivers by Non-Native Fish: The Importance of Environmental Drivers and Human Pressures

    PubMed Central

    Ilhéu, Maria; Matono, Paula; Bernardo, João Manuel

    2014-01-01

    Invasive species are regarded as a biological pressure to natural aquatic communities. Understanding the factors promoting successful invasions is of great conceptual and practical importance. From a practical point of view, it should help to prevent future invasions and to mitigate the effects of recent invaders through early detection and prioritization of management measures. This study aims to identify the environmental determinants of fish invasions in Mediterranean-climate rivers and evaluate the relative importance of natural and human drivers. Fish communities were sampled in 182 undisturbed and 198 disturbed sites by human activities, belonging to 12 river types defined for continental Portugal within the implementation of the European Union's Water Framework Directive. Pumpkinseed sunfish, Lepomis gibbosus (L.), and mosquitofish, Gambusia holbrooki (Girard), were the most abundant non-native species (NNS) in the southern river types whereas the Iberian gudgeon, Gobio lozanoi Doadrio and Madeira, was the dominant NNS in the north/centre. Small northern mountain streams showed null or low frequency of occurrence and abundance of NNS, while southern lowland river types with medium and large drainage areas presented the highest values. The occurrence of NNS was significantly lower in undisturbed sites and the highest density of NNS was associated with high human pressure. Results from variance partitioning showed that natural environmental factors determine the distribution of the most abundant NNS while the increase in their abundance and success is explained mainly by human-induced disturbance factors. This study stresses the high vulnerability of the warm water lowland river types to non-native fish invasions, which is amplified by human-induced degradation. PMID:25372284

  8. Force transmission via axial tendons in undulating fish: a dynamic analysis.

    PubMed

    Long, John H; Adcock, Bruce; Root, Robert G

    2002-12-01

    Sonomicrometrics of in vivo axial strain of muscle has shown that the swimming fish body bends like a homogenous, continuous beam in all species except tuna. This simple beam-like behavior is surprising because the underlying tendon structure, muscle structure and behavior are complex. Given this incongruence, our goal was to understand the mechanical role of various myoseptal tendons. We modeled a pumpkinseed sunfish, Lepomis gibbosus, using experimentally-derived physical and mechanical attributes, swimming from rest with steady muscle activity. Axially oriented muscle-tendons, transverse and axial myoseptal tendons, as suggested by current morphological knowledge, interacted to replicate the force and moment distribution. Dynamic stiffness and damping associated with muscle activation, realistic muscle force generation, and force distribution following tendon geometry were incorporated. The vertebral column consisted of 11 rigid vertebrae connected by joints that restricted bending to the lateral plane and endowed the body with its passive viscoelasticity. In reaction to the acceleration of the body in an inviscid fluid and its internal transmission of moment via the vertebral column, the model predicted the kinematic response. Varying only tendon geometry and stiffness, four different simulations were run. Simulations with only intrasegmental tendons produced unstable axial and lateral tail forces and body motions. Only the simulation that included both intra- and intersegmental tendons, muscle-enhanced segment stiffness, and a stiffened caudal joint produced stable and large lateral and axial forces at the tail. Thus this model predicts that axial tendons function within a myomere to (1) convert axial force to moment (moment transduction), (2) transmit axial forces between adjacent myosepta (segment coupling), and, intersegmentally, to (3) distribute axial forces (force entrainment), and (4) stiffen joints in bending (flexural stiffening). The fact that all

  9. An assessment of fish assemblage structure in a large river

    USGS Publications Warehouse

    Kiraly, Ian A.; Coghlan, S.M.; Zydlewski, Joseph; Hayes, D.

    2015-01-01

    The Penobscot River drains the largest watershed in Maine and once provided spawning and rearing habitats to 11 species of diadromous fishes. The construction of dams blocked migrations of these fishes and likely changed the structure and function of fish assemblages throughout the river. The proposed removal of two main-stem dams, improved upstream fish passage at a third dam, and construction of a fish bypass on a dam obstructing a major tributary is anticipated to increase passage of and improve habitat connectivity for both diadromous and resident fishes. We captured 61 837 fish of 35 species in the Penobscot River and major tributaries, through 114 km of boat electrofishing. Patterns of fish assemblage structure did not change considerably during our sampling; relatively few species contributed to seasonal and annual variability within the main-stem river, including smallmouth bass Micropterus dolomieu, white sucker Catostomus commersonii, pumpkinseed Lepomis gibbosus, and golden shiner Notemigonus crysoleucas. However, distinct fish assemblages were present among river sections bounded by dams. Many diadromous species were restricted to tidal waters downriver of the Veazie Dam; Fundulus species were also abundant within the tidal river section. Smallmouth bass and pumpkinseed were most prevalent within the Veazie Dam impoundment and the free-flowing river section immediately upriver, suggesting the importance of both types of habitat that supports multiple life stages of these species. Further upriver, brown bullhead Ameiurus nebulosus, yellow perch Perca flavescens, chain pickerel Esox niger, and cyprinid species were more prevalent than within any other river section. Our findings describe baseline spatial patterns of fish assemblages in the Penobscot River in relation to dams with which to compare assessments after dam removal occurs.

  10. How well can fishes prey on zebra mussels in eastern North America?

    USGS Publications Warehouse

    French, John R. P.

    1993-01-01

    Literature on mollusk-eating fishes was reviewed to determine the potential for different species of fish to control zebra mussels in eastern North America. At least six species are potential predators of zebra mussels because they possess (1) both upper and lower pharyngeal teeth or (2) lower pharyngeal teeth and chewing pads located on the dorsal roof for crushing mollusk shells. Freshwater drum (Aplodinotus grunniens) and two centrarchids, redear sunfish (Lepomis microlophus) and pumpkinseed (L. gibbosus), possess both upper and lower pharyngeal teeth and are likely to consume more zebra mussels than fishes with only lower pharyngeal teeth. Only two catostomid species, copper and river redhorses (Moxostoma hubbsi and M. carinatum), have chewing pads that enable them to crush mollusks. The exotic omnivorous common carp (Cyprinus carpio), possessing lower teeth and a chewing pad, may prey on zebra mussels when aquatic insect larvae, its preferred food, become rare. Managing populations of drum, sunfishes and redhorses to reduce exploitation of large individuals and improve their habitats are suggested as means to intensify biological control of zebra mussels in eastern North America. Other Eurasian molluscivores, the roach (Rutilus rutilus) and the black carp (Mylopharyngodon piceus) should not be introduced into North America because research has shown repeatedly that an introduced biological controller usually does not forage for unwanted pests or reside only in preferred habitats of pests. Drum, sunfishes and redhorses should be preferred over these exotics as biological controllers of zebra mussels in North America because these native fishes will likely occupy newly established habitats of zebra mussels.

  11. Centrarchid identification and natural history

    Treesearch

    M.L. Warren

    2009-01-01

    The family Centrarchidae (Order: Perciformes) is one of the most diverse, widespread, and conspicuous fish families native to freshwater habitats of North America. Among endemic fish families of North America, only the North American catfish family (Ictaluridae) has more species. The family name, Centrarchidae, refers to the anal fin spines of species in the family,...

  12. Assessment of tolerant sunfish populations (Lepomis sp.) inhabiting selenium-laden coal ash effluents. 3. Serum chemistry and fish health indicators.

    PubMed

    Lohner, T W; Reash, R J; Willet, V E; Fletcher, J

    2001-11-01

    Sunfish were collected from fly ash discharge-receiving streams to assess the possible effects of exposure to elevated selenium. Concentrations of selenium, copper, and arsenic were statistically higher in fish tissue (liver) samples from effluent-exposed fish than in reference fish. Several biomarkers were indicative of metal exposure and effect. Plasma protein levels and cholesterol levels were significantly lower in exposed fish, indicating nutritional stress. Ion levels (i.e., K) increased with exposure to ash pond metals, indicating possible gill damage. Fish from the receiving streams also had increased serum glucose and osmolality indicating possible acute stress due to sampling. Fish health assessments revealed a lower incidence of fin erosion, kidney discoloration, urolithiasis or nephrocalcinosis, liver discoloration, and parasites in exposed fish and a higher incidence of skin, eye, and gill aberrations. Condition factors of exposed fish were correlated with biomarker response and were the same as or lower than those of reference fish, but not related to selenium levels. Although several serum biochemical indicators differed between the ash pond-receiving stream and reference sites, pollutant exposure was apparently not sufficient to cause functional damage to critical organ systems.

  13. EVIDENCE OF OXIDATIVE STRESS IN BLUEGILL SUNFISH (LEPOMIS MACROCHIRUS) LIVER MICROSOMES SIMULTANEOUSLY EXPOSURE TO SOLAR ULTRAVIOLET RADIATION AND ANTHRACENE. (R823873)

    EPA Science Inventory

    The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

  14. Priority effects among young-of-the-year fish: Reduced growth of bluegill sunfish (Lepomis macrochirus) caused by yellow perch (Perca flavescens)?

    USGS Publications Warehouse

    Kaemingk, Mark A.; Jolley, Jeff C.; Willis, David W.; Chipps, Steven R.

    2012-01-01

    1. When available, Daphnia spp. are often preferred by age-0 yellow perch and bluegill sunfish because of energetic profitability. We hypothesised that predation by age-0 yellow perch could lead to a midsummer decline (MSD) of Daphnia spp. and that priority effects may favour yellow perch because they hatch before bluegill, allowing them to capitalise on Daphnia spp. prior to bluegill emergence.2. Data were collected from 2004 to 2010 in Pelican Lake, Nebraska, U.S.A. The lake experienced a prolonged MSD in all but 1 year (2005), generally occurring within the first 2 weeks of June except in 2008 and 2010 when it occurred at the end of June. MSD timing is not solely related to seasonal patterns of age-0 yellow perch consumption. Nevertheless, when Daphnia spp. biomass was low during 2004 and 2006–2010 (<4 mg wet weight L−1), predation by age-0 yellow perch seems to have suppressed Daphnia spp. biomass (i.e. <1.0 mg wet weight L−1). The exception was 2005 when age-0 yellow perch were absent.3. Growth of age-0 bluegill was significantly faster in 2005, when Daphnia spp. were available in greater densities (>4 mg wet weight L−1) compared with the other years (<0.2 mg wet weight L−1).4. We conclude that age-0 yellow perch are capable of reducing Daphnia biomass prior to the arrival of age-0 bluegill, ultimately slowing bluegill growth. Thus, priority effects favour age-0 yellow perch when competing with age-0 bluegill for Daphnia. However, these effects may be minimised if there is a shorter time between hatching of the two species, higher Daphnia spp. densities or lower age-0 yellow perch densities.

  15. Fish and Aquatic Invertebrate Communities in Waterways, and Contaminants in Fish, at the Barataria Preserve of Jean Lafitte National Historical Park and Preserve, Louisiana, 1999-2000

    USGS Publications Warehouse

    Swarzenski, Christopher M.; Mize, Scott V.; Thompson, Bruce A.; Peterson, Gary W.

    2004-01-01

    Fish and aquatic invertebrate communities in waterways of the Barataria Preserve of Jean Lafitte National Historical Park and Preserve, Louisiana, were surveyed from 1999 to 2000. An inventory of fish in the Barataria Preserve was established, and concentrations of selected organochlorine pesticides, polychlorinated biphenyls, and trace elements; iron; and manganese in fish tissue for selected species were determined. The fish and aquatic invertebrate sampling completed for this study indicated that abundant and diverse communities are present in the Barataria Preserve. Thirty-two species of fish were identified in the Barataria Preserve during this survey. The total number of species identified in a single sampling ranged from 20 to 26. Most of the fish sampled are designated as intermediate in their tolerance to poor water quality. Three species of fish designated as tolerant (common carp, Cyprinus carpio; golden shiner, Notemigonus crysoleucas; and yellow bullhead, Ameiurus natalis), and one as intolerant (lake chubsucker, Erymizon sucetta), were identified. In November 1999, the average total weight of all fish collected by boat-mounted electroshocker from a single site was about 35,000 grams; in May and July 1999, the average total weight was between 9,000 and 10,000 grams. The contribution of spotted gar (Lepisosteus oculatus) to the total weight of the fish averaged between 38 and 41 percent among the three sample periods. Members of the sunfish family (Centrarchidae) contributed between 18 and 28 percent of the total weight. For each sampling period, 60 to 83 percent of the total weight from the sunfish family was contributed by bluegill (Lepomis macrochirus) and largemouth bass (Micropterus salmoides). Aquatic invertebrates were sampled at three sites. Most aquatic invertebrates identified were freshwater species, but some were brackish-water and marine species. About 234,000 organisms were identified and enumerated from the richest-targeted habitat (RTH

  16. Phylogenetic signals in detoxification pathways in Cyprinid and Centrarchid species in relation to sensitivity to environmental pollutants.

    PubMed

    van den Hurk, Peter; Gerzel, Lindsay E; Calomiris, Peter; Haney, Dennis C

    2017-07-01

    Observations in a previous study on biomarker responses in fish collected from urban creeks in Greenville, SC, indicated that there might be considerable differences in the expression of biotransformation enzymes in chub and sunfish species. To further investigate these species differences a dosing experiment was performed in which bluehead and creek chub (Nocomis leptocephalus and Semotilus atromaculatus), and redbreast sunfish, pumpkinseed, and bluegill (Lepomis auritus, L. gibbosus, and L. macrochirus) were injected with benzo[a]pyrene (BaP) as a model compound for common pollutants in urban creeks. Fish were injected with BaP doses of 0, 25 and 50mg/kg, and after 3days BaP metabolites in bile, and enzymatic activities of cytochrome P450-1A (CYP1A), UDP-glucuronosyltransferase (UGT) and glutathione S-transferase (GST) were measured. CYP1A activity was significantly increased after BaP dosing in both species groups, but chubs had significantly lower levels than were observed in the dosed sunfish. The UGT activity in unexposed animals was comparable in both species groups, and significantly increased in both groups as a result of BaP dosage. Finally, GST activity was significantly higher in chubs, but did not change in either species group as a result of BaP exposure. There were no significant differences between species within each species group, and the results confirmed that unexposed chubs have much lower CYP1A activity, but a much higher GST activity than unexposed sunfish. The metabolized BaP was excreted in both species groups, but at the time of sampling there were no differences in the amount of BaP metabolites in the bile of dosed animals. The differences in baseline enzyme activity and induction capacity between both species groups are an example of phylogenetically determined differences between fish families, and may explain why chubs are in general more sensitive to exposure to environmental pollutants than sunfish. This conclusion was corroborated

  17. Assessment of Habitat, Fish Communities, and Streamflow Requirements for Habitat Protection, Ipswich River, Massachusetts, 1998-99

    USGS Publications Warehouse

    Armstrong, David S.; Richards, Todd A.; Parker, Gene W.

    2001-01-01

    The relations among stream habitat, fish communities, and hydrologic conditions were investigated in the Ipswich River Basin in northeastern Massachusetts. Data were assessed from 27 sites on the mainstem of the Ipswich River from July to September 1998 and from 10 sites on 5 major tributaries in July and August 1999. Habitat assessments made in 1998 determined that in a year with sustained streamflow for most of the summer, the Ipswich River contains diverse, high-quality aquatic habitat. Channel types are predominantly low gradient glides, pools, and impoundments, with a sandy streambed and a forest or shrub riparian zone. Features that provide fish habitat are located mostly along stream margins; these features include overhanging brush, undercut banks, exposed roots, and woody debris. These habitat features decrease in availability to aquatic communities with declining streamflows and generally become unavailable after streamflows drop to the point where the edge of water recedes from the stream banks.The mainstem and tributaries were sampled to determine fish species composition, relative abundance, and length frequency. Fish sampling indicates that the fish community in the Ipswich River is currently a warm-water fish community dominated by pond-type fish. However, historical temperature data, and survival of stocked trout in the mainstem Ipswich into late summer of 1998, indicate that the Ipswich River potentially could support cold-water fish species if adequate flows are maintained. Dominant fish species sampled in the mainstem Ipswich River were redfin pickerel (Esox americanus), American eel (Anguilla rostrata), and pumpkinseed (Lepomis gibbosus), which together represented 41, 22, and 10 percent, respectively, of 4,745 fish sampled. The fish communities of the mainstem and tributaries contained few fluvial-dependent or fluvial-specialist species (requiring flow), and were dominated by macrohabitat generalists (tolerant of low-flow, warm-water, and

  18. Survival of vaccinated,feed-trained largemouth bass fry (Micropterus Salmoides Floridanus) during natural exposure to Flavobacterium columnare

    USDA-ARS?s Scientific Manuscript database

    Largemouth bass (Micropterus salmoides floridanus; Centrarchidae) are often reared in government hatchery programs, then stocked to supplement wild fish populations. After the eggs obtained from broodstock are hatched, fry are stocked into ponds to feed on zooplankton and other small invertebrates....

  19. Concentrations of Elements in Hellbender Blood and Fish Fillets from the Missouri Department of Conservation Monitoring Programs

    USGS Publications Warehouse

    May, Thomas W.; Walther, Mike J.; Brumbaugh, William G.

    2007-01-01

    This report presents the results of contaminant monitoring surveys conducted annually by the Missouri Department of Conservation to examine the levels of selected elemental contaminants in hellbender (Cryptobranchus alleganiensis) blood and fish. Catfish (Ictalurus furcatus, Ictalurus punctatus, Pylodictis olivaris), redhorse (Moxostoma anisorum, Moxostoma erythrurum), bass (Micropterus salmoides, Micropterus punctulatus, Micropterus Lacepede, Ambloplites rupestris), walleye (Sander vitreus), and sunfish (Lepomis megalotis) were collected from 17 sites as part of the Department's General Contaminant Monitoring Program. Bluegill (Lepomis macrochirus) and other sunfish (Lepomis megalotis, Lepomis cyanellus) were collected from 18 sites as part of the Department's Resource Assessment and Monitoring Program. Blood from hellbenders was collected from seven sites as part of the Department's Hellbender Monitoring Program.

  20. The trade-off between food and temperature in the habitat choice of bluegill sunfish

    USGS Publications Warehouse

    Wildhaber, M.L.

    2001-01-01

    A model is presented to describe the trade-off between food and temperature in bluegills Lepomis macrochirus, where temperature was the primary factor used in determining the patch in which to reside.

  1. Environmental Impact Analysis Process. Draft Environmental Impact Statement, Winnersville Weapons Range, Lanier and Lowndes Counties, Georgia

    DTIC Science & Technology

    1985-07-01

    of fish caught during electrofishing ....... ................. 35 Table 3.5. Population densities, Lanier and Lowndes counties . . . 37 Table 4.1...numbers of fish caught during electrofishing Common name Scientific name Bluegill Lepomis macrochirus Largemouth bass Micropterus salmoides Lake

  2. INDICATORS OF GENETIC DAMAGE IN MODEL STREAM FISH USING CONTROLLED LABORATORY EXPOSURES

    EPA Science Inventory

    The micronucleus (MN) and single cell gel electrophoresis (SCG) assays are being applied to peripheral blood cells from several fish species using model genotoxicants and envirornmentally relevant pollutants. In initial studies, bluegill sunfish (Lepomis macrochirus, 4 to 5 per ...

  3. AN INTEGRATED EVALUATION OF THE PERSISTENCE AND EFFECTS OF 4-NONYLPHENOL IN AN EXPERIMENTAL LITTORAL ECOSYSTEM

    EPA Science Inventory

    Toxicity and bioaccumulation in bluegill sunfish (Lepomis macrochirus) of 4-nonphenyol (NP), a common precursor and degradation intermediate of certain nonionic surfactants, were evaluated in a set of 18 aquatic mesocosms (littoral enclosures) in northeastern Minnesota. Nonylphe...

  4. Aquatic Habitat Studies on the Lower Mississippi River, River Mile 480 to 530. Report 8. Summary.

    DTIC Science & Technology

    1982-02-01

    fields, and revetted banks) in the Lower Mississippi River. Specific objectives were: a. To quantitatively define effects of the age , size, and...Eight families were collected: Clupeidae, Hiodontidae, Cyprinidae, Catostomidae , Percichthyidae, Centrarchidae, Percidae, and Sciaenidae. This was...the system was to provide for at least 10 to 15 ecologi- cal variables (e.g., trophic level, sexual condition, age , growth stage, etc.) for subsequent

  5. A review of the genus Apristurus (Chondrichthyes: Carcharhiniformes: Scyliorhinidae) from Taiwanese waters.

    PubMed

    Nakaya, Kazuhiro; Kawauchi, Junro

    2013-01-01

    Sharks of the genus Apristurus from Taiwanese waters are reviewed for the first time, and incorrect scientific names and wrong taxonomic information given in the literature are corrected. After extensive examination of specimens deposited in various museums, universities and fisheries institutions in Taiwan, Japan and China, the following five species are recognized from Taiwanese waters: Apristurus herklotsi (Fowler, 1934), A. longicephalus Nakaya, 1975, A. gibbosus Meng, Chu & Li, 1985, A. macrostomus Chu, Meng & Li, 1985, and A. platyrhynchus (Tanaka, 1909). Apristurus herklotsi, A. longicephalus, A. gibbosus and A. macrostomus are reported from Taiwanese waters for the first time, and the presence of A. platyrhynchus is formally recognized based on a single voucher specimen. Each species is fully described, and a key to the species of Apristurus in Taiwanese waters is provided. Morphological and biological information of each species is also provided.

  6. A revision of the South African riffle beetle genus Leielmis Delève, 1964 (Coleoptera: Elmidae).

    PubMed

    Bilton, David T

    2017-04-12

    The riffle beetle genus Leielmis Delève, 1964 is redescribed and shown to contain three species, all of which are apparently endemic to the South African Cape, where they live in permanent mountain streams with cold running water. A lectotype is designated for Helmis georyssoides Grouvelle, 1890, and two additional species (L. gibbosus sp. nov. and L. hirsutus sp. nov.) are described for the first time. Following study of the type series, L. georyssoides is shown to be endemic to Table Mountain; most specimens previously assigned to this taxon representing an additional species (L. gibbosus sp. nov.), widespread in the interior Cape Fold Mountains. The record of Leielmis from Angola is considered highly doubtful. Comparative notes and a key are provided to allow the identification of known species of the genus.

  7. Toxicity of TNT Wastewaters to Aquatic Organisms. Volume 2. Acute Toxicity of Condensate Wastewater and 2,4-Dinitrotoluene

    DTIC Science & Technology

    1983-03-01

    magna), scud (Hyalella azteca), and worm ( Lumbriculus variegatus ); but T. dissimilis was the least sensitive invertebrate species to synthetic...midge) Lumbriculus variegatus (oligochaete) Fish Pimephales promelas (fathead minnow) Lepomis machrochirus (bluegill sunfish) Ictalurus punctatus...day bioconcentration test data were less than 100 in bluegills, D. magna, and L. variegatus , but 2100 to 2500 in the alga S. capricornutum. In bluegills

  8. DNA DAMAGE AND VITELLOGENIN RESPONSES IN FERAL FISH EXPOSED TO URBANIZATION AND WASTE WATER TREATMENT EFFLUENT IN SOUTH CAROLINA, USA

    EPA Science Inventory

    This study was designed to look at the impact of urbanization and a wastewater treatment plant (WWTP) by using field-collected bluegill (Lepomis machrochkrus). Fish were collected from four locations in the same river: above city (reference); below city and above the WWTP; direc...

  9. DNA DAMAGE AND VITELLOGENIN RESPONSES IN FERAL FISH EXPOSED TO URBANIZATION AND WASTE WATER TREATMENT EFFLUENT IN SOUTH CAROLINA, USA

    EPA Science Inventory

    This study was designed to look at the impact of urbanization and a wastewater treatment plant (WWTP) by using field-collected bluegill (Lepomis machrochkrus). Fish were collected from four locations in the same river: above city (reference); below city and above the WWTP; direc...

  10. Draft Genome Sequence of Aeromonas hydrophila TN97-08

    PubMed Central

    Tekedar, Hasan C.; Kumru, Salih; Karsi, Attila; Waldbieser, Geoffrey C.; Sonstegard, Tad; Schroeder, Steven G.; Liles, Mark R.; Griffin, Matt J.

    2016-01-01

    Aeromonas hydrophila is an opportunistic pathogen residing in freshwater environments that causes infection in fish and mammals. Here, we report the draft genome sequence of A. hydrophila strain TN97-08 isolated from a diseased bluegill (Lepomis macrochirus) in 1997. PMID:27231367

  11. Environmental Concentrations, Fate, and Risk Assessment of Pyrethrins and Piperonyl Butoxide After Aerial Ultralow-Volume Applications for Adult Mosquito Management

    DTIC Science & Technology

    2008-01-01

    end point) for PBO samples taken 1 h before the appli- cation for Daphnia magna , rainbow trout (Oncorhynchus my- kiss), and bluegill sunfish (Lepomis...after application in Princeton for D. magna , rainbow trout, and bluegill sunfish were 0.0003, less than 0.0001, and less than 0.0001, respectively

  12. Terrestrial and Aquatic Biological Inventory; Meredosia Lake and Willow Creek Drainage and Levee District: Cass and Morgan Counties, Illinois.

    DTIC Science & Technology

    1982-12-01

    X Blacknose shiner Notropis herterolepis x Bantam sunfish Lepomis symmetricus x Lake whitefish Coregonus clupeaformis x Lake sturgeon Acipenser ... fulvescens x Higgin’s Eye Lampsilis higginsii X Pearly Mussel Pink Mucket Lampsilis orbiculata orbiculata X Pearly Mussel Orange-footed Plethobasis

  13. The complete mitochondrial genomes of largemouth bass of the northern subspecies (Micropterus salmoides salmoides) and Florida subspecies (Micropterus salmoides floridanus) and their applications in the identification of largemouth bass species.

    PubMed

    Li, Sheng-Jie; Bai, Jun-Jie; Cai, Lei; Ma, Dong-Mei; Du, Fang-Fang

    2012-04-01

    The largemouth bass belongs to the family Centrarchidae, which includes two subspecies: the northern subspecies, Micropterus salmoides salmoides, and the Florida subspecies, Micropterus salmoides floridanus. In this study, the complete mitochondrial genomes of the two subspecies were sequenced, and their genetic differences were identified. The mitogenomes of M. s. salmoides and M. s. floridanus are 16,486 and 16,479 bp in length, respectively. The two subspecies consisted of 37 genes (13 protein-coding genes, 2 ribosomal RNA, and 22 transfer RNA), which are typical for vertebrate mtDNA. Phylogenetic analysis provided statistical support for the monophyly of the family Centrarchidae. Comparison of the two subspecies' mitogenomes revealed a relatively high number (450) of single nucleotide polymorphisms (SNPs) in protein-coding genes. We characterized SNPs in the partial cytochrome c oxidase subunit 1 gene of different individuals from three cultured populations, one wild northern subspecies population, and one wild Florida subspecies population. Twenty-eight SNPs were fixed with alternative nucleotides in the two subspecies, which could be used for differentiating them. Based on this gene, phylogenetic tree and genetic distance analyses supported that cultured largemouth bass in China belongs to the northern subspecies.

  14. Three new records of copepods (Siphonostomatoida) parasitic on marine fishes of Iraq, including the relegation of two species of Lernanthropinus to Lernanthropinus temminckii (von Nordmann, 1864).

    PubMed

    Venmathi Maran, B A; Moon, Seong Yong; Adday, Thamir Katea; Khamees, Najim Rijab; Myoung, Jung-Goo

    2014-03-01

    Three parasitic copepods (Siphonostomatoida) belonging to three different genera were recovered from marine fishes of Iraq, and are listed here as new records. The sea lice Caligus epinepheli Yamaguti, 1936 (Caligidae) was collected from the Japanese threadfin bream, Nemipterus japonicus (Bloch). It had been frequently reported from teleost fishes around the world. The second record, comprising male and female, was another caligid, rarely caught from fishes - Hermilius longicornis Bassett-Smith, 1898, collected from the giant catfish, Netuma thalassina (Rüppell). This paper features the first description of the male of the latter species. The third record was the lernanthropid, Lernanthropinus temminckii (von Nordmann, 1864) (Lernanthropidae), redescribed based on the specimens collected from the greater lizard fish, Saurida tumbil (Bloch) (Synodontidae). In order to clarify its taxonomic status, our specimen was compared with the holotype of L. gibbosus (Pillai, 1964) from the collections of Zoological Survey of India, Kolkata, and the syntypes of L. sauridae Do in Ho and Do, 1985 and L. temminckii from the collections of the Smithsonian Institution, Washington D.C. We found similarities in the morphology of the body, mouthparts, and legs 1-4 in three above-mentioned species. The prominent feature, the setation pattern of legs 1 and 2 was similar in all the female specimens examined. In the light of this, we formally relegate L. gibbosus and L. sauridae to synonymy with L. temminckii. Another important similarity is that Lernanthropinus gibbosus, L. sauridae, and L. temminckii have exclusively been parasitic on lizardfishes (Synodontidae). The attachment site of all three copepods reported form Iraq were the gill filaments.

  15. Mollusk collecting and environmental change during the Prehistoric Period in the Mariana Islands

    NASA Astrophysics Data System (ADS)

    Amesbury, J. R.

    2007-12-01

    Archaeological research in the Mariana Islands has revealed changes in mollusk collecting during the Prehistoric Period (approximately 1500 BC to AD 1521). The earliest people at Tumon Bay, Guam and Chalan Piao, Saipan collected mostly bivalves, especially the arc clam Anadara antiquata. After several hundred years, they no longer collected A. antiquata, but collected smaller bivalves instead. By AD 1000, they collected mostly gastropods, primarily the coral reef species Strombus gibberulus gibbosus. One possible explanation is that the people preferred the large arc clam but overharvested it until they were forced to eat the smaller bivalves and then the snails. However, recent evidence in the form of mangrove wood and mangrove pollen supports another explanation, one of non-anthropogenic environmental change. In this case, the relative sea-level decline, which took place in the Marianas within the last 4,000 years, caused the demise of mangrove habitats and of the arc clam at Tumon Bay, Guam and Chalan Piao, Saipan. As mangrove habitats were diminished by sea-level decline, collecting effort shifted to coral reefs, and S. gibberulus gibbosus was harvested throughout the remainder of the Prehistoric Period and into the Historic Period. Southern Guam is the only area in the Marianas in which A. antiquata increased in abundance during the Prehistoric Period. The same types of evidence, mangrove wood and mangrove pollen, indicate that, in contrast to the situation at Tumon Bay and Chalan Piao, mangroves increased in abundance in southern Guam.

  16. Sublethal Effects of JP-4 on Aquatic Organisms and Communities.

    DTIC Science & Technology

    1984-01-01

    Spearman - Karber statistical analysis which does not depend on the presence of partial kills to generate an LC5O. With the this statistical technique...sunfish (Lepomis macrochirus). An abstract of the results of this research can be found in Part I of report. II. MATERIALS AND METHODS A. Manufacture...was performed on the pooled samples of whole blood using the cyanomethemoglobin method . c. The RBC counts were conducted after diluting the whole blood

  17. Habitat Suitability Index Models and Instream Flow Suitability Curves: Warmouth

    USGS Publications Warehouse

    McMahon, Thomas E.; Gebhart, Glen; Maughan, O. Eugene; Nelson, Patrick C.

    1984-01-01

    The wa rmouth (Lepomi s gul osus) occurs naturally throughout the central and southeastern United States. It is distributed throughout Kansas, Iowa, and Missouri, north to southern Wisconsin, lower Michigan, Lake Erie, and western Pennsylvania, and south to Florida and west through the Gulf States to the Rio Grande (Hubbs and Lagler 1947; Larimore 1957). It has been introduced into California (Hubble 1966; Moyle 1976), Arizona (Minckley 1973), and other western states (Smith 1896).

  18. An evaluation of fluorescent elastomer for marking bluegills in experimental studies

    USGS Publications Warehouse

    Dewey, Michael R.; Zigler, Steven J.

    1996-01-01

    We evaluated subdermal injection of a fluorescent elastomer for marking bluegills Lepomis macrochirus in laboratory and pond studies. Marking did not affect the growth or survival of adult or juvenile bluegills. Marks were visible for at least 6 months. This technique is a reliable, relatively inexpensive marking method for the identification of individual fish in experimental studies. Costs of application range from US$0.01 to $0.03 per mark.

  19. Food and feeding of fish in Hartwell Reservoir tailwater, Georgia-South Carolina

    USGS Publications Warehouse

    Barwick, D. Hugh; Hudson, Patrick L.

    1985-01-01

    Food of silver redhorse (Moxostoma anisurum), redbreast sunfish (Lepomis auritus), green sunfish (L. cyanellus), and bluegills (L. macrochirus) was examined to determine whether or not these fish in the Hartwell Reservoir tailwater (Savannah River, Georgia-South Carolina) ate organisms entrained from the reservoir or displaced from the tailwater during water releases associated with the production of hydropower. These fish fed primarily on aquatic insects, crayfish, and terrestrial organisms originating from the tailwater. Major periods of feeding occurred during nongeneration.

  20. Is evolution gradual or rectangular? Evidence from living fishes.

    PubMed Central

    Avise, J C

    1977-01-01

    The traditional view that most evolutionary change is gradual and cumulative within lineages (phyletic gradualism) has recently been challenged by the proposition that the majority of evolutionary change is concentrated within speciation events (rectangular evolution). The logical implications of these competing hypotheses for the means and variances of genetic distance among living members of rapidly and slowly speciating phylads are examined. An example of a critical test of gradual versus rectangular evolution is provided by electrophoretic analyses of genic composition in 69 species of North American Cyprinidae (minnows), and 19 species of Centrarchidae (sunfish). Rate of protein evolution appears somewhat decelerated, if anything, in the rapidly speciating minnows. Results are inconsistent with predictions of rectangular evolution, but are not demonstrably incongruent with predictions of phyletic gradualism. PMID:270743

  1. Endocrine active contaminants in aquatic systems and intersex in common sport fishes.

    PubMed

    Lee Pow, Crystal S D; Law, J Mac; Kwak, Thomas J; Cope, W Gregory; Rice, James A; Kullman, Seth W; Aday, D Derek

    2017-04-01

    Male fish are susceptible to developing intersex, a condition characterized by the presence of testicular oocytes. In the present study, the relationship between intersex and exposure to estrogenic endocrine active contaminants (EACs) was assessed for 2 genera of sport fish, Micropterus and Lepomis, at 20 riverine sites. Seasonal trends and relationships between EACs and intersex (prevalence and severity) were examined at varying putative sources of EACs throughout North Carolina, identified as point sources, nonpoint sources, and reference sites. Intersex was identified in both genera, which was documented for the first time in wild-caught Lepomis. Intersex was more prevalent (59.8%) and more severe (1.6 mean rank) in Micropterus, which was highly correlation to EACs in sediment. In contrast, intersex was less common (9.9%) and less severe (0.2 mean rank) in Lepomis and was highly correlated to EACs in the water column. The authors found that concentrations of polycyclic aromatic hydrocarbons, polychlorinated biphenyls, industrial EACs, and estrogens were highest at point source sites; however, no source type variation was identified in the prevalence or severity of intersex, nor were there seasonal trends in intersex or EAC concentrations. The authors' results associate genus-specific prevalence of intersex with specific EAC classes in common sport fishes having biological, ecological, and conservation implications. Environ Toxicol Chem 2017;36:959-968. © 2016 SETAC. © 2016 SETAC.

  2. Endocrine active contaminants in aquatic systems and intersex in common sport fishes

    USGS Publications Warehouse

    Lee Pow, Crystal S. D.; Law, J. Mac; Kwak, Thomas J.; Cope, W. Gregory; Rice, James A.; Kullman, Seth W.; Aday, D. Derek

    2017-01-01

    Male fish are susceptible to developing intersex, a condition characterized by the presence of testicular oocytes. In the present study, the relationship between intersex and exposure to estrogenic endocrine active contaminants (EACs) was assessed for 2 genera of sport fish, Micropterus and Lepomis, at 20 riverine sites. Seasonal trends and relationships between EACs and intersex (prevalence and severity) were examined at varying putative sources of EACs throughout North Carolina, identified as point sources, nonpoint sources, and reference sites. Intersex was identified in both genera, which was documented for the first time in wild-caught Lepomis. Intersex was more prevalent (59.8%) and more severe (1.6 mean rank) in Micropterus, which was highly correlation to EACs in sediment. In contrast, intersex was less common (9.9%) and less severe (0.2 mean rank) in Lepomis and was highly correlated to EACs in the water column. The authors found that concentrations of polycyclic aromatic hydrocarbons, polychlorinated biphenyls, industrial EACs, and estrogens were highest at point source sites; however, no source type variation was identified in the prevalence or severity of intersex, nor were there seasonal trends in intersex or EAC concentrations. The authors’ results associate genus-specific prevalence of intersex with specific EAC classes in common sport fishes having biological, ecological, and conservation implications.

  3. Effects of zebra mussels on food webs: Interactions with juvenile bluegill and water residence time

    USGS Publications Warehouse

    Richardson, W.B.; Bartsch, L.A.

    1997-01-01

    We evaluated how water residence time mediated the impact of zebra mussels Dreissena polymorpha and bluegill sunfish Lepomis macrochirus on experimental food webs established in 1100-1 outdoor mesocosms. Water residence time was manipulated as a surrogate for seston resupply - a critical variable affecting growth and survival of suspension-feeding invertebrates. We used a 2 x 2 x 2 factorial experimental design with eight treatment combinations (3 replicates/treatment) including the presence or absence of Dreissena (2000 per m2), juvenile bluegill (40 per mesocosm), and short (1100 1 per d) or long (220 1 per d) water residence time. Measures of seston concentration (chlorophyll a, turbidity and suspended solids) were greater in the short- compared to long water-residence mesocosms, but intermediate in short water-residence mesocosms containing Dreissena. Abundance of rotifers (Keratella and Polyarthra) was reduced in Dreissena mesocosms and elevated in short residence time mesocosms. Cladocera abundance, in general, was unaffected by the presence of Dreissena; densities were higher in short-residence time mesocosms, and reduced in the presence of Lepomis. The growth of juvenile Lepomis were unaffected by Dreissena because of abundant benthic food. The final total mass of Dreissena was significantly greater in short- than long-residence mesocosms. Impacts of Dreissena on planktonic food webs may not only depend on the density of zebra mussels but also on the residence time of the surrounding water and the resupply of seston. ?? 1997 Kluwer Academic Publishers.

  4. Movements by two small fishes in a large stream

    USGS Publications Warehouse

    Freeman, Mary C.

    1995-01-01

    Movements by adult Percina nigrojasciata and juvenile Lepomis auritus were examined in a large Coastal Plain stream in the southeastern United States. I marked fishes with subcutaneous injections of acrylic paints to indicate capture location within a 550-m long study site. Recaptures over an 18-month period primarily occurred within 33m of the original capture location, suggesting long-term residence in relatively small areas. However, 11 Percina and three Lepomis moved at least 100 m (maximum distance moved = 200 m for Lepomis, 420 m for Percina), and individuals of both species shifted between distinctly different mesohabitats (boulder riffle, sand pool, and gravel riffle). Distance moved did not strongly relate to time between captures. Long-distance movements (> 33 m) by Percina mostly occurred from Nov. through June. The winter and springtime movements by darters occurred in upstream and downstream directions and into all three mesohabitats, and at least 40% of these movements were unassociated with periods of extreme high flow. Periodic long-range movements may allow small fishes to respond to variation in resources over a large area and across a variety of stream habitats.

  5. Potential human health risk by 234,238U and 210Po due to consumption of fish from the "Luis L. Leon" reservoir (Northern Mexico)

    NASA Astrophysics Data System (ADS)

    Luna-Porres, M. Y.; Rodríguez-Villa, M. A.; Herrera-Peraza, E.; Cabral-Lares, M.; Renteria-Villalobos, M.; Montero-Cabrera, M. E.

    2014-07-01

    The Conchos River is one of the most important in northern Mexico and the main surface waterway in the arid state of Chihuahua. The Luis L. Leon dam produces the Luis L. Leon Reservoir, which is the last major reservoir before the Conchos River enters the Rio Grande at the Texas-Chihuahua border. Activity concentrations (AC) of 234,238U and 210Po in fillet and liver of three stocked fish species (Lepomis cyanellus, Cyprinus carpio and Ictalurus furcatus), as well as in water from the Luis L. Leon reservoir were determined. 238U and 234U ACs in fillet samples showed values of 0.007-0.014 and 0.01-0.02 Bq kg-1 wet weight (ww), respectively. Liver samples for Lepomis cyanellus, Cyprinus carpio and Ictalurus furcatus species, present 210Po AC of 1.16-3.26 0.70-1.13 and 0.93-1.37 Bqṡkg-1 ww. The elemental Bioaccumulation Factor (BAF) for fish tissues respect to their concentrations in water was determined. Lepomis cyanellus species showed the highest BAF for total uranium in fillet, with value 1.5. The annual effective dose for uranium in adults by fish consumption in this work ranged from 4.46×10-3 to 3.68×10-2 μSvṡyear-1. The difference in concentrations of uranium in fillet among the studied species is likely primarily due to their differences in diet and habitat.

  6. STIMULATION BY HYDROCHLORIC ACID AND BY THE NORMAL ALIPHATIC ACIDS IN THE SUNFISH EUPOMOTIS

    PubMed Central

    Allison, James B.

    1932-01-01

    1. The reaction of the sunfish, Eupomotis gibbosus, to different concentrations of hydrochloric acid and of the first six members of the N aliphatic acids has been studied. 2. The stimulating efficiency of hydrochloric acid may best be related to the concentration of hydrogen ions produced by that acid. 3. The stimulating efficiency of the N aliphatic acids may best be correlated with the non-polar nature of a portion of the molecule, but it is necessary to consider the higher potential of the polar group of formic acid to account satisfactorily for its position in the series. 4. When equally effective concentrations of the N aliphatic acids are compared, formic acid is more effective at lower concentrations than at higher. 5. Per cent variation in response appears to be independent of the chemical environment to which the animal responded. PMID:19872671

  7. STIMULATION BY THE MINERAL ACIDS, HYDROCHLORIC, SULFURIC, AND NITRIC, IN THE SUNFISH EUPOMOTIS.

    PubMed

    Cole, W H; Allison, J B

    1933-03-20

    1. The stimulating efficiency of hydrochloric, sulfuric, and nitric acids has been measured in the sunfish Eupomotis gibbosus, by a method which reduces experimental errors to a minimum. 2. The results show that stimulation by these acids is primarily dependent upon the (H(+)) produced in the animal's aquatic environment, and that the reaction time is a logarithmic function of the (H(+)) within the range tested expressed by the equation: (RT-5) = -4.3 log (H(+) x 10(4)) + 9.118. 3. Any effect of the chloride, sulfate, and nitrate ions must itself be measured by the (H(+)). 4. Variation in the reaction time is also a logarithmic function of the (H(+)), and the percentage variation is independent of the (H(+)) over the range tested. 5. Freshly collected fish show a lower threshold for stimulation as determined by the (H(+)) than do fish adapted to laboratory conditions, but relatively the reaction times of the two groups are the same.

  8. STIMULATION BY THE MINERAL ACIDS, HYDROCHLORIC, SULFURIC, AND NITRIC, IN THE SUNFISH EUPOMOTIS

    PubMed Central

    Cole, William H.; Allison, J. B.

    1933-01-01

    1. The stimulating efficiency of hydrochloric, sulfuric, and nitric acids has been measured in the sunfish Eupomotis gibbosus, by a method which reduces experimental errors to a minimum. 2. The results show that stimulation by these acids is primarily dependent upon the (H+) produced in the animal's aquatic environment, and that the reaction time is a logarithmic function of the (H+) within the range tested expressed by the equation: (RT–5) = –4.3 log (H+ x 104) + 9.118. 3. Any effect of the chloride, sulfate, and nitrate ions must itself be measured by the (H+). 4. Variation in the reaction time is also a logarithmic function of the (H+), and the percentage variation is independent of the (H+) over the range tested. 5. Freshly collected fish show a lower threshold for stimulation as determined by the (H+) than do fish adapted to laboratory conditions, but relatively the reaction times of the two groups are the same. PMID:19872730

  9. The effect of model choice on phylogenetic inference using mitochondrial sequence data: lessons from the scorpions.

    PubMed

    Jones, Martin; Gantenbein, Benjamin; Fet, Victor; Blaxter, Mark

    2007-05-01

    Chelicerates are a diverse group of arthropods, with around 65,000 described species occupying a wide range of habitats. Many phylogenies describing the relationships between the various chelicerate orders have been proposed. While some relationships are widely accepted, others remain contentious. To increase the taxonomic sampling of species available for phylogenetic study based on mitochondrial genomes we produced the nearly complete sequence of the mitochondrial genome of the scorpion Mesobuthus gibbosus. Mitochondrial gene order in M. gibbosus largely mirrors that in Limulus polyphemus but tRNA secondary structures are truncated. A recent analysis argued that independent reversal of mitochondrial genome strand-bias in several groups of arthropods, including spiders and scorpions, could compromise phylogenetic reconstruction and proposed an evolutionary model that excludes mutational events caused by strand-bias (Neutral Transitions Excluded, NTE). An arthropod dataset of six mitochondrial genes, when analyzed under NTE, yields strong support for scorpions as sister taxon to the rest of Chelicerata. We investigated the robustness of this result by exploring the effect of adding additional chelicerate genes and taxa and comparing the phylogenies obtained under different models. We find evidence that (1) placement of scorpions arising at the base of the Chelicerata is an artifact of model mis-specification and scorpions are strongly supported as basal arachnids and (2) an expanded chelicerate dataset finds support for several proposed interordinal relationships (ticks plus mites [Acari] and spiders plus whip spiders plus whip scorpions [Araneae+Pedipalpi]). Mitochondrial sequence data are subject to systematic bias that is positively misleading for evolutionary inference and thus extreme methodological care must be taken when using them to infer phylogenies.

  10. Comparative morphology of the postpharyngeal gland in the Philanthinae (Hymenoptera, Crabronidae) and the evolution of an antimicrobial brood protection mechanism.

    PubMed

    Weiss, Katharina; Strohm, Erhard; Kaltenpoth, Martin; Herzner, Gudrun

    2015-12-21

    Hymenoptera that mass-provision their offspring have evolved elaborate antimicrobial strategies to ward off fungal infestation of the highly nutritive larval food. Females of the Afro-European Philanthus triangulum and the South American Trachypus elongatus (Crabronidae, Philanthinae) embalm their prey, paralyzed bees, with a secretion from a complex postpharyngeal gland (PPG). This coating consists of mainly unsaturated hydrocarbons and reduces water accumulation on the prey's surface, thus rendering it unfavorable for fungal growth. Here we (1) investigated whether a North American Philanthus species also employs prey embalming and (2) assessed the occurrence and morphology of a PPG among females of the subfamily Philanthinae in order to elucidate the evolution of prey embalming as an antimicrobial strategy. We provide clear evidence that females of the North American Philanthus gibbosus possess large PPGs and embalm their prey. The comparative analyses of 26 species from six genera of the Philanthinae, using histological methods and 3D-reconstructions, revealed pronounced differences in gland morphology within the subfamily. A formal statistical analysis based on defined characters of the glands confirmed that while all members of the derived tribe Philanthini have large and complex PPGs, species of the two more basal tribes, Cercerini and Aphilanthopsini, possess simple and comparatively small glands. According to an ancestral state reconstruction, the complex PPG most likely evolved in the last common ancestor of the Philanthini, thus representing an autapomorphy of this tribe. Prey embalming, as described for P. triangulum and T. elongatus, and now also for P. gibbosus, most probably requires a complex PPG. Hence, the morphology and size of the PPG may allow for inferences about the origin and distribution of the prey embalming behavior within the Philanthinae. Based on our results, we suggest that prey embalming has evolved as an antimicrobial strategy in

  11. Host specificity of a parasitic fluke: is Posthodiplostomum minimum a centrarchid-infecting generalist or specialist?

    PubMed

    Lane, Beth; Spier, Timothy; Wiederholt, Julia; Meagher, Shawn

    2015-02-01

    Parasite host specificity has important implications for species diversity estimates, food web dynamics, and host shifts. "White grub" is the metacercaria stage of a fluke ( Posthodiplostomum minimum ) that occurs in many fish species, but no attempt has been made to quantify variation in host use by this worm. Here we used 2 approaches to evaluate host specificity within the strain that infects centrarchids ( P. minimum centrarchi). First, we measured parasite loads in 2 centrarchid hosts, bluegill ( Lepomis macrochirus ) and white crappie ( Pomoxis annularis ), from Spring Lake in McDonough County, Illinois. We found that infection levels differed significantly between these hosts. Prevalence in bluegill was 100% and the median intensity was 940 metacercariae, but only 57% of white crappie were infected (median intensity = 4). Site specificity of white grub also differed significantly between the 2 hosts. In bluegills, kidneys were most heavily infected, whereas in white crappies, livers harbored the most worms. We also performed a literature survey of P. minimum prevalence estimates from 14 centrarchid species from other localities. We calculated the mean white grub prevalence for each host species and used this to calculate STD*, a quantitative index of host specificity. STD* was 1.33, significantly closer to the value for a specialist (STD* = 1.00) than a generalist (STD* = 2.00). This reflects the fact that P. minimum prevalence is higher in Lepomis species than it is in centrarchids outside this genus. These data show that P. minimum centrarchi specializes on Lepomis species, but the causes of this specialization are unknown. This worm may be a single species that differs in host use due to ecological or physiological host differences, or it may be a complex of species that vary in host use for similar reasons. Genetic data are required to evaluate these possibilities.

  12. Effects of littoral habitat complexity and sunfish composition on fish production

    USGS Publications Warehouse

    Carey, M.P.; Maloney, K.O.; Chipps, S.R.; Wahl, David H.

    2010-01-01

    Habitat complexity is a key driver of food web dynamics because physical structure dictates resource availability to a community. Changes in fish diversity can also alter trophic interactions and energy pathways in food webs. Few studies have examined the direct, indirect, and interactive effects of biodiversity and habitat complexity on fish production. We explored the effects of habitat complexity (simulated vegetation), sunfish diversity (intra- vs. inter-specific sunfish), and their interaction using a mesocosm experiment. Total fish production was examined across two levels of habitat complexity (low: 161 strands m-2 and high: 714 strands m-2) and two sunfish diversity treatments: bluegill only (Lepomis macrochirus) and bluegill, redear sunfish (Lepomis microlophus), and green sunfish (Lepomis cyanellus) combination. We also measured changes in total phosphorus, phytoplankton, periphyton, and invertebrates to explain patterns in fish production. Bluegill and total fish production were unaffected by the sunfish treatments. Habitat complexity had a large influence on food web structure by shifting primary productivity from pelagic to a more littoral pathway in the high habitat treatments. Periphyton was higher with dense vegetation, leading to reductions in total phosphorus, phytoplankton, cladoceran abundance and fish biomass. In tanks with low vegetation, bluegill exhibited increased growth. Habitat complexity can alter energy flow through food webs ultimately influencing higher trophic levels. The lack of an effect of sunfish diversity on fish production does not imply that conserving biodiversity is unimportant; rather, we suggest that understanding the context in which biodiversity is important to food web dynamics is critical to conservation planning. ?? 2010 John Wiley & Sons A/S.

  13. Influence of prey abundance on size-selective predation by bluegills

    SciTech Connect

    Bartell, S.M.

    1982-01-01

    Bluegills Lepomis macrochirus in Lake Wingra consume zooplankton in a size-selective fashion. Length-frequency distributions of ingested and available prey demonstrated that bluegills feed on a smaller range of ever larger Daphnia galeata and Bosmina longirostris as these prey species increased in abundance. The same was not apparent for Cyclops bicuspidatus as prey. Regression of intensity-of-selection indices for Daphnia and Bosmina versus their combined abundance suggests that these prey species are not differentiated by bluegills in Lake Wingra.

  14. Habitat use by larval fishes in backwater lake of the upper Mississippi River

    USGS Publications Warehouse

    Dewey, M.R.; Jennings, C.A.

    1992-01-01

    Light traps were used to sample larval fishes in Lawrence Lake (Pool 8, upper Mississippi River) from late May through mid-August 1990. Catches differed considerably between vegetated sites and an adjacent open- water area and were highly variable among vegetated stations. Sunfishes (Lepomis spp.) dominated the vegetated sites. Brook silversides (Labidesthes sicculus), Cyprinidae ad gizzard shad (Dorosoma cepedianum) dominated catches at the open-water site. There was no difference in fish use of vegetated habitats near and far from the main channel of the Mississippi River. Taxonomic diversity was greatest at stations with emergent vegetation.

  15. Degradation of organophosphates by fish liver phosphatases

    USGS Publications Warehouse

    Hogan, James W.; Knowles, Charles O.

    1968-01-01

    Liver homogenates of bluegill, Lepomis macrochirus Rafinesque, and channel catfish, Ictalurus punctatus (Walbaum), were shown by a manometric technique to contain soluble enzymes capable of degrading diisopropyl phosphorofluoridate (DFP) and 2,2-dichlorovinyl dimethyl phosphate (dichlorvos). Hydrolysis of the compounds was greatest in the presence of the manganic ion. Tentative identification of certain of the hydrolysis products suggested that cleavage of the anhydride bond was a degradation pathway for DFP and dichlorvos in vitro under the assay conditions employed. Substrate summation, inhibition, and activation experiments failed to clearly indicate more than a single enzyme hydrolyzing DFP and dichlorvos in the two fish.

  16. Environmental and water-quality operational studies. Prey selection and feeding patterns of fish in a Southern United States hydropower tailwater. Final report

    SciTech Connect

    Barwick, D.; Hudson, P.L.; Nestler, J.M.

    1985-10-01

    The downstream effects of peaking hydropower generation at Lake Hartwell Georgia-South Carolina, on the diel prey selection and feeding of four species of fish-silver redhorse (Moxostoma anisurum), redbreast sunfish (Lepomis auritus), green sunfish (L. cyanellus), and bluegill (L. macrochirus)--were determined. Aquatic insects (primarily dipterans, ephemeropterans, and trichopterans), crayfish, and terrestrial organisms (primarily insects) composed most of the food eaten. These fish fed primarily during daylight, before daily hydropower generation began, and little or no feeding occurred during generation. Consequently, few organisms entrained from the reservoir or displaced from the tailwater during hydropower generation were eaten by these fish.

  17. Fish mortality and physicochemistry in a managed floodplain wetland

    USGS Publications Warehouse

    Sargent, J.C.; Galat, D.L.

    2002-01-01

    Patterns of fish mortality and associated physicochemical factors were studied during late spring in a managed wetland canal along the lower Missouri River, Missouri. Mean dawn dissolved oxygen was lower and mean un-ionized ammonia and turbidity were higher during the fish kill than before or after the kill, or than was observed in a nearby wetland canal where no fish kill occurred. Dissolved oxygen at dawn and un-ionized ammonia concentrations were at critically low and high levels respectively, so that both likely contributed to the fish mortality. Timing and magnitude of observed carcasses suggested that Ameiurus melas Rafinesques was the most tolerant species for the sizes observed compared to Ictiobus cyprinellus Valenciennes, Lepomis macrochirus Rafinesque, Cyprinus carpio Linneaus, and Lepomis cyanellus Rafinesque. Decreasing mean lengths of fish carcasses during the fish kill for C. carpio, L. cyanellus, and A. melas, indicate that smaller fishes may have been more tolerant of harsh environmental conditions than larger individuals of the same species. Differential mortalities among species and sizes during drawdowns in actively managed wetland pools may have intentional and unintentional ramifications on wetland and riverine fish community structure, fish-avian interactions, and implementing an ecosystem management perspective to restoring more naturalized river floodplain wetland functions. Late summer and early autumn draining of managed wetlands might be used to benefit a wider diversity of wildlife and fishes.

  18. Effects of predatory fish on survival and behavior of larval gopher frogs (Rana capito) and Southern Leopard Frogs (Rana sphenocephala)

    USGS Publications Warehouse

    Gregoire, D.R.; Gunzburger, M.S.

    2008-01-01

    Southern Leopard Frogs, Rana sphenocephala, are habitat generalists occurring in virtually all freshwater habitats within their geographic range, whereas Gopher Frogs, Rana capito, typically breed in ponds that do not normally contain fish. To evaluate the potential for predation by fish to influence the distribution of these species, we conducted a randomized factorial experiment. We examined the survival rate and behavior of tadpoles when exposed to Warmouth Sunfish, Lepomis gulosus, Banded Sunfish, Enneacanthus obesus, and Eastern Mosquitofish, Gambusia holbrooki. We also conducted a choice experiment to examine the survival rate of the two species of tadpoles when a predator is given a choice of both species simultaneously. Lepomis gulosus consumed the most tadpoles and ate significantly more tadpoles of R. capito than R. sphenocephala. Gambusia holbrooki injured the most tadpoles, especially R. capito. Enneacanthus obesus did not have an effect on behavior or survival of either anuran species. Tadpoles of both anurans increased hiding when in the presence of L. gulosus and G. holbrooki, but a greater proportion of R. capito hid than did R. sphenocephala. Our results suggest that R. capito are more vulnerable to predation by fish than are R. sphenocephala. The introduction of fish may play a role in population declines of certain anurans breeding in normally fish-free wetlands, and even small fish, such as mosquitofish, may have significant negative effects on the tadpoles of R. capito. Copyright 2008 Society for the Study or Amphibians and Reptiles.

  19. Prey vulnerability to peacock cichlids and largemouth bass based on predator gape and prey body depth

    USGS Publications Warehouse

    Hill, Jeffrey E.; Nico, Leo G.; Cichra, Charles E.; Gilbert, Carter R.

    2005-01-01

    The interaction of prey fish body depth and predator gape size may produce prey assemblages dominated by invulnerable prey and excessive prey-to-predator biomass ratios. Peacock cichlids (Cichla ocellaris) were stocked into southeast Florida canals to consume excess prey fish biomass, particularly spotted tilapia (Tilapia mariae). The ecomorphologically similar largemouth bass (Micropterus salmoides) was already present in the canals. We present relations of length-specific gape size for peacock cichlids and largemouth bass. Both predators have broadly overlapping gape size, but largemouth bass ?126 mm total length have slightly larger gape sizes than peacock cichlids of the same length. Also, we experimentally tested the predictions of maximum prey size for peacock cichlids and determined that a simple method of measuring gape size used for largemouth bass also is appropriate for peacock cichlids. Lastly, we determined relations of body depth and length of prey species to investigate relative vulnerability. Using a simple predator-prey model and length frequencies of predators and bluegill (Lepomis macrochirus), redear sunfish (Lepomis microlophus), and spotted tilapia prey, we documented that much of the prey biomass in southeast Florida canals is unavailable for largemouth bass and peacock cichlid predation.

  20. Hypoxia tolerance of two centrarchid sunfishes and an introduced cichlid from karstic Everglades wetlands of southern Florida, U.S.A.

    USGS Publications Warehouse

    Schofield, P.J.; Loftus, W.F.; Brown, M.E.

    2007-01-01

    In this study, the hypoxia tolerance of three Everglades fishes, two native centrarchids (Lepomis gulosus and Lepomis marginatus) and a recently introduced cichlid (Hemichromis letourneuxi), were documented. Aquatic surface respiration (ASR) thresholds were lowest for H. letourneuxi, followed by L. gulosus, then L. marginatus. The ASR thresholds for L. marginatus were within ranges reported for small, freshwater tropical fishes, while those for L. gulosus were similar to swamp-adapted fishes. For H. letourneuxi, ASR thresholds were some of the lowest reported. All three species showed excellent tolerance of low dissolved oxygen levels when allowed access to the surface. When denied surface access, L. marginatus lost equilibrium at a higher oxygen tension than the other species. Overall, although all species easily tolerated hypoxia, H. letourneuxi appeared to be best equipped to deal with hypoxia, followed by L. gulosus, then L. marginatus. Hemichromis letourneuxi also exhibited more aggressive behaviours than the centrarchids. These results suggest that hypoxia is not likely to prevent H. letourneuxi from exploiting the seasonally inundated wetlands of south Florida while expanding its range there.

  1. Cumberlandian Mollusk Conservation Program. Activity 3: identification of fish hosts. [Conradilla caelata; Quadrula intermedia; Epioblasma brevidens; Epioblasma capsaeformis; Epioblasma triquetra; Quadrula cylindrica; Carunculina moesta

    SciTech Connect

    Hill, D.M.

    1986-02-01

    A key element of the Cumberlandian Mollusk Conservation Program undertaken by TVA in 1979 was the determination of fish hosts of Cumberlandian mussel species unique to the Tennessee River drainage and especially the species whose habitat would be inundated by completion of Columbia Dam on the Duck River, Tennessee. Principal emphasis was placed on the birdwing pearly mussel, Conradilla caelata and the Cumberland monkeyface, Quadrula intermedia - two federally listed endangered species with limited distributions outside the proposed inundation zone of the Duck River. Additional species studied included three species of the genus Epioblasma (E. brevidens, E. capsaeformis, and E. triquetra), Quadrula cylindrica, Villosa iris, and Carunculina moesta. Experimental glochidial infection of 55 fish species resulted in the establishment of the following mussel-fish host relationships: Conradilla caelata - Etheostoma zonale; Quadrule intermedia - Hybopsis dissimilis, Hybopsis insignis; Epioblasma brevidens - Etheostoma blennioides, Etheostoma maculatum, Etheostoma rufilineatum, Etheostoma simoterum, Percina caprodes, Cottus carolinae; Epioblasma capsaeformis - Etheostoma maculatum, Etheostoma rufilineatum, Percina sciera, Cottus carolinae; Epioblasma triquetra - Percina caprodes, Cottus carolinae; Quadrula cylindrica - Notropis galacturus, Notropis spilopterus, Hybopsis amblops; and Carunculina moesta - Lepomis cyanellus, Lepomis megalotis.

  2. Electrofishing survey of the Great Miami River, September 17--18, 1996. Annual report

    SciTech Connect

    Moller, B.; Miller, M.C.; Buschelmann, F.; Evans, R.L.

    1996-12-31

    The electrofishing survey of fish from the Great Miami River at RM 19, 24 and 38 from late summer 1996 demonstrated the sensitivity of the fish community to microhabitat variation. The variation was particularly clear between the pooled, low flow sections of the river and the runs, where fast current habitats occurred. In 1996, like most recent years, the differences were obvious between Rm 24 and RM 19 and RM 38. River Mile 24 was characterized by a fish community of current-loving fish, dominated by Catastomidae (suckers), and Ictaluridae (catfish). In contrast, samples from pooled stations at RM 19 and 38 were dominated by Centrarchidae, Clupeidae and Cyprinidae, particularly the carp. The microhabitats sampled around the abutments of bridges at RM 19 and 38 where fast current and physical structure occurred, both resembled the community at RM 24. Changes in the fish communities associated with the upstream/downstream changes in stream volume, channel size, morphology, etc., were evidenced by the community coefficients which showed least similarity between the most distant sites.

  3. Experimental acidification of Little Rock Lake (Wisconsin): fish research approach and early responses.

    PubMed

    Swenson, W A; McCormick, J H; Simonson, T D; Jensen, K M; Eaton, J G

    1989-01-01

    One goal of research at Little Rock Lake, Wisconsin, is to enhance understanding of lake acidification effects on warm- and cool-water fishery resources. The Little Rock Lake fish assemblage is characteristic of many acid sensitive waters in North America and is dominated by yellow perch (Percidae) and sunfishes (Centrarchidae). Analyses of reproduction, early survival and growth rates in the field were designed around the differing reproductive modes of these taxa. Complementary laboratory research on early life stages was conducted to assist in isolating direct effect mechanisms and to determine the reliability of laboratory results in predicting field response. Preliminary findings suggest that lake acidification to pH 5.6 has not influenced reproductive activity of the four most abundant fish species. However, the field results suggest that year-class failure of rock bass (Ambloplites rupestris) may be occurring due to reduced survival of early life stages. Reduced growth and food conversion efficiency of Age 0 largemouth bass (Micropterus salmoides) is also suggested. The laboratory bioassays indicate rock bass is the most acid-sensitive Little Rock Lake species tested. However, rock bass fry survival was not significantly affected until pH was reduced from 5.6 to 5.0.

  4. Observations on the distribution and biology of Huffmanela huffmani (Nematoda: Trichosomoididae).

    PubMed

    Cox, Marlin K; Huffman, David G; Moravec, Frantisek

    2004-03-01

    The nematode parasite Huffmanela huffmani Moravec, 1987 (Trichosomoididae) infects swimbladders of fishes in the family Centrarchidae. Only fish collected from the upper San Marcos River (Texas) have been found infected with H. huffmani eggs with a prevalence of 90%. Hundreds of thousands of H. huffmani eggs have been observed in these fish but only a few specimens of adult worms have ever been found. The San Marcos River arises from springs along the Balcones Fault Zone in San Marcos, Hays County, Texas. The restriction of the parasite to the upper San Marcos River and the high prevalence of the parasite eggs in centrarchids would seem to enable one to solve the life cycle of H. huffmani but this has proved false. Here, the insights and experiments used to help define some of the aspects concerning the life cycle of this enigmatic parasite are described. This study of H. huffmani includes a description of the habitat, the known limits of geographic distribution of the parasite, possible dispersal processes, egg characteristics, the testing of a possible intermediate host, Palaemonetes antrorum (Benedict) (Decapoda: Palaemonidae), and the effects of the digestion process on H. huffmani eggs.

  5. Electrofishing effort required to estimate biotic condition in southern Idaho Rivers

    USGS Publications Warehouse

    Maret, Terry R.; Ott, Douglas S.; Herlihy, Alan T.

    2007-01-01

    An important issue surrounding biomonitoring in large rivers is the minimum sampling effort required to collect an adequate number of fish for accurate and precise determinations of biotic condition. During the summer of 2002, we sampled 15 randomly selected large-river sites in southern Idaho to evaluate the effects of sampling effort on an index of biotic integrity (IBI). Boat electrofishing was used to collect sample populations of fish in river reaches representing 40 and 100 times the mean channel width (MCW; wetted channel) at base flow. Minimum sampling effort was assessed by comparing the relation between reach length sampled and change in IBI score. Thirty-two species of fish in the families Catostomidae, Centrarchidae, Cottidae, Cyprinidae, Ictaluridae, Percidae, and Salmonidae were collected. Of these, 12 alien species were collected at 80% (12 of 15) of the sample sites; alien species represented about 38% of all species (N = 32) collected during the study. A total of 60% (9 of 15) of the sample sites had poor IBI scores. A minimum reach length of about 36 times MCW was determined to be sufficient for collecting an adequate number of fish for estimating biotic condition based on an IBI score. For most sites, this equates to collecting 275 fish at a site. Results may be applicable to other semiarid, fifth-order through seventh-order rivers sampled during summer low-flow conditions.

  6. Evidence of a Shift in the Littoral Fish Community of the Sacramento-San Joaquin Delta

    PubMed Central

    Farruggia, Mary Jade; Schreier, Brian; Sommer, Ted

    2017-01-01

    Many estuarine and freshwater ecosystems worldwide have undergone substantial changes due to multiple anthropogenic stressors. Over the past two decades, the Sacramento-San Joaquin Delta (Delta) in California, USA, saw a severe decline in pelagic fishes, a shift in zooplankton community composition, and a rapid expansion of invasive aquatic vegetation. To evaluate whether major changes have also occurred in the littoral fish community, we analyzed a beach seine survey dataset collected from 1995 to 2015 from 26 sites within the Delta. We examined changes in the Delta fish community at three different ecological scales (species, community, and biomass), using clustering analyses, trend tests, and change-point analyses. We found that the annual catch per effort for many introduced species and some native species have increased since 1995, while few experienced a decline. We also observed a steady pattern of change over time in annual fish community composition, driven primarily by a steady increase in non-native Centrarchid species. Lastly, we found that littoral fish biomass has essentially doubled over the 21-year study period, with Mississippi Silverside Menidia audens and fishes in the Centrarchidae family driving most of this increase. The changes in the catch per effort, fish community composition, and biomass per volume indicate that a shift has occurred in the Delta littoral fish community and that the same factors affecting the Delta’s pelagic food web may have been a key driver of change. PMID:28118393

  7. Evidence of a Shift in the Littoral Fish Community of the Sacramento-San Joaquin Delta.

    PubMed

    Mahardja, Brian; Farruggia, Mary Jade; Schreier, Brian; Sommer, Ted

    2017-01-01

    Many estuarine and freshwater ecosystems worldwide have undergone substantial changes due to multiple anthropogenic stressors. Over the past two decades, the Sacramento-San Joaquin Delta (Delta) in California, USA, saw a severe decline in pelagic fishes, a shift in zooplankton community composition, and a rapid expansion of invasive aquatic vegetation. To evaluate whether major changes have also occurred in the littoral fish community, we analyzed a beach seine survey dataset collected from 1995 to 2015 from 26 sites within the Delta. We examined changes in the Delta fish community at three different ecological scales (species, community, and biomass), using clustering analyses, trend tests, and change-point analyses. We found that the annual catch per effort for many introduced species and some native species have increased since 1995, while few experienced a decline. We also observed a steady pattern of change over time in annual fish community composition, driven primarily by a steady increase in non-native Centrarchid species. Lastly, we found that littoral fish biomass has essentially doubled over the 21-year study period, with Mississippi Silverside Menidia audens and fishes in the Centrarchidae family driving most of this increase. The changes in the catch per effort, fish community composition, and biomass per volume indicate that a shift has occurred in the Delta littoral fish community and that the same factors affecting the Delta's pelagic food web may have been a key driver of change.

  8. Constructed Pools-and-Riffles: Application and Assessment in Illinois.

    NASA Astrophysics Data System (ADS)

    Day, D. M.; Dodd, H. R.; Carney, D. A.; Holtrop, A. M.; Whiles, M. R.; White, B.; Roseboom, D.; Kinney, W.; Keefer, L. L.; Beardsley, J.

    2005-05-01

    The diversity of Illinois' streams provides a broad range of conditions, and thus a variety of restoration techniques may be required to adequately compensate for watershed alterations. Resource management agencies and research institutions in the state have collaborated on a variety of applied research initiatives to assess the efficacy of various stream protection and restoration techniques. Constructed pool-and-riffle structures have received significant attention because they tend to address watershed processes (i.e., channel evolution model) and may benefit biotic communities and processes along with physical habitat. Constructed pools-and-riffles have been applied primarily to address geomorphic instability, yet understanding biological responses can provide further rationale for their use and design specifications. In three stream systems around the state, fish were collected pre- and post- installation of structures, using primarily electrofishing techniques (e.g., electric seine & backpack). In general, within the first five years after installation, changes in fish communities have included a shift from high-abundance, small cyprinid-dominated assemblages to low-density Centrarchidae and Catostomidae assemblages. Changes in macro invertebrates at selected sites included increases in filter feeders and sensitive taxa such as the Ephemeroptera, Plecoptera, and Trichoptera (EPT). Ongoing assessments will be critical for understanding long-term influences on stream ecosystem structure and function.

  9. Larval fish dynamics in spring pools in middle Tennessee

    USGS Publications Warehouse

    Bettoli, Phillip William; Goldsworthy, C.A.

    2011-01-01

    We used lighted larval traps to assess reproduction by fishes inhabiting nine spring pools in the Barrens Plateau region of middle Tennessee between May and September 2004. The traps (n = 162 deployments) captured the larval or juvenile forms of Etheostoma crossopterum (Fringed Darter) (n = 188), Gambusia affinis (Western Mosquitofish) (n = 139), Hemitremia flammea (Flame Chub) (n = 55), the imperiled Fundulus julisia (Barrens Topminnow) (n = 10), and Forbesichthys agassizii (Spring Cavefish) (n = 1). The larval forms of four other species (Families Centrarchidae, Cyprinidae, and Cottidae) were not collected, despite the presence of adults. Larval Barrens Topminnow hatched over a protracted period (early June through late September); in contrast, hatching intervals were much shorter for Fringed Darter (mid-May through early June). Flame Chub hatching began before our first samples in early May and concluded by late-May. Juvenile Western Mosquitofish were collected between early June and late August. Our sampling revealed that at least two species (Flame Chub and Fringed Darter) were able to reproduce and recruit in habitats harboring the invasive Western Mosquitofish, while Barrens Topminnow could not.

  10. Epizootiology of Eustrongylides ignotus in Florida: distribution, density, and natural infections in intermediate hosts.

    PubMed

    Coyner, Donald F; Spalding, Marilyn G; Forrester, Donald J

    2002-07-01

    A total of 63,451 fish, representing 39 species, was collected from 176 foraging sites used by ciconiiform wading birds in peninsular Florida (USA) and examined for larvae of Eustrongylides ignotus. Infected fish were identified from 30 (17%) of the sites, all of which had been altered by human disturbance such as removal of sediment to construct ditches and dikes, improve water flow, or increase storage capacity and had a history of receiving anthropogenic nutrients such as sewage effluent, urban runoff, or agricultural runoff. The mosquitofish (Gambusia holbrooki) and several species of sunfish (Centrarchidae) were the most important intermediate hosts. Infected fish were not collected at any of the unaltered sites. A total of 10,508 oligochaetes (representing 36 species) was identified from 22 sites that had fish infected with E. ignotus and 36 sites where no infected fish were collected. None of the oligochaetes was infected with larvae of E. ignotus. Immature tubificids without hair setae (probably Limnodrilus sp.), Dero digitata, and L. hoffmeisteri were the most abundant oligochaetes at sites where infected fish occurred, making up 78% of the total collected. Compared to unaltered sites, altered sites were characterized by higher mean densities of fish and oligochaetes; surface waters with decreased dissolved oxygen and increased total nitrogen, total phosphorus, and chlorophyll-a; sediments with higher soil oxygen demand and total phosphorus; larger grain sizes; and higher percentage emergent vegetation and grasses.

  11. Connectedness of land use, nutrients, primary production, and fish assemblages in oxbow lakes

    USGS Publications Warehouse

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

    2013-01-01

    We explored the strength of connectedness among hierarchical system components associated with oxbow lakes in the alluvial valley of the Lower Mississippi River. Specifically, we examined the degree of canonical correlation between land use (agriculture and forests), lake morphometry (depth and size), nutrients (total nitrogen and total phosphorus), primary production (chlorophyll-a), and various fish assemblage descriptors. Watershed (p < 0.01) and riparian (p = 0.02) land use, and lake depth (p = 0.05) but not size (p = 0.28), were associated with nutrient concentrations. In turn, nutrients were associated with primary production (p < 0.01), and primary production was associated with sunfish (Centrarchidae) assemblages (p < 0.01) and fish biodiversity (p = 0.08), but not with those of other taxa and functional guilds. Multiple chemical and biological components of oxbow lake ecosystems are connected to landscape characteristics such as land use and lake depth. Therefore, a top-down hierarchical approach can be useful in developing management and conservation plans for oxbow lakes in a region impacted by widespread landscape changes due to agriculture.

  12. Discordance between morphological and mechanical diversity in the feeding mechanism of centrarchid fishes.

    PubMed

    Collar, David C; Wainwright, Peter C

    2006-12-01

    Morphological diversity is routinely used to infer ecological variation among species because differences in form underlie variation in functional performance of ecological tasks like capturing prey, avoiding predators, or defending territories. However, many functions have complex morphological bases that can weaken associations between morphological and functional diversification. We investigate the link between these levels of diversity in a mechanically explicit model of fish suction-feeding performance, where the map of head morphology to feeding mechanics is many-to-one: multiple, alternative forms can produce the same mechanical property. We show that many-to-one mapping leads to discordance between morphological and mechanical diversity in the freshwater fish family, the Centrarchidae, despite close associations between morphological changes and their mechanical effects. We find that each of the model's five morphological variables underlies evolution of suction capacity. Yet, the major centrarchid clades exhibit an order of magnitude range in diversity of suction mechanics in the absence of any clear difference in diversity of the morphological variables. This cryptic pattern of mechanical diversity suggests an evolutionary history for suction performance that is unlike the one inferred from comparisons of morphological diversity. Because many-to-one mapping is likely to be common in functional systems, this property of design may lead to widespread discordance between functional and morphological diversity. Although we focus on the interaction between morphology and mechanics, many-to-one mapping can decouple diversity between levels of organization in any hierarchical system.

  13. Composition of Age-0 Fish Assemblages in the Apalachicola River, River Styx, and Battle Bend, Florida

    USGS Publications Warehouse

    Walsh, Stephen J.; Buttermore, Elissa N.; Burgess, O. Towns; Pine, William E.

    2009-01-01

    Light traps were used to sample the age-0 year class of fish communities in the Apalachicola River and associated floodplain water bodies of River Styx and Battle Bend, Florida, in 2006-2007. A total of 629 light traps were deployed during the spring and early summer months (341 between March 15 and June 6, 2006; 288 between March 9 and July 3, 2007). For combined years, 13.8 percent of traps were empty and a total of 20,813 age-0 fish were captured representing at least 40 taxa of 29 genera and 16 families. Trap catches were dominated by relatively few species, with the most abundant groups represented by cyprinids, centrarchids, percids, and catostomids. Six taxa accounted for about 80 percent of all fish collected: Micropterus spp. (28.9 percent), Notropis texanus (28.9 percent), Lepomis macrochirus (7.9 percent), Carpiodes cyprinus (6.2 percent), Cyprinidae sp. (4.6 percent), and Minytrema melanops (4.2 percent). Based on chronological appearance in light traps and catch-per-unit effort, including data from previous years of sampling, peak spawning periods for most species occurred between early March and mid-June. A complementary telemetry study of pre-reproductive adults of select target species (Micropterus spp., Lepomis spp., and M. melanops) revealed distinct patterns of habitat use, with some individual fish exclusively utilizing mainstem river habitat or floodplain habitat during spawning and post-spawning periods, and other individuals migrating between habitats. A comparison of light-trap catches between a pre-enhancement, high-water year (2003) and post-enhancement, low-water year (2007) for the oxbow at Battle Bend revealed some difference in community composition, with slightly greater values of diversity and evenness indices in 2007. Two dominant species, Lepomis macrochirus and Micropterus salmoides, were substantially greater in relative abundance among all age-0 fish collected in 2007 in comparison to 2003. Excavation of sediments at the mouth

  14. Ocean acidification alters predator behaviour and reduces predation rate.

    PubMed

    Watson, Sue-Ann; Fields, Jennifer B; Munday, Philip L

    2017-02-01

    Ocean acidification poses a range of threats to marine invertebrates; however, the emerging and likely widespread effects of rising carbon dioxide (CO2) levels on marine invertebrate behaviour are still little understood. Here, we show that ocean acidification alters and impairs key ecological behaviours of the predatory cone snail Conus marmoreus Projected near-future seawater CO2 levels (975 µatm) increased activity in this coral reef molluscivore more than threefold (from less than 4 to more than 12 mm min(-1)) and decreased the time spent buried to less than one-third when compared with the present-day control conditions (390 µatm). Despite increasing activity, elevated CO2 reduced predation rate during predator-prey interactions with control-treated humpbacked conch, Gibberulus gibberulus gibbosus; 60% of control predators successfully captured and consumed their prey, compared with only 10% of elevated CO2 predators. The alteration of key ecological behaviours of predatory invertebrates by near-future ocean acidification could have potentially far-reaching implications for predator-prey interactions and trophic dynamics in marine ecosystems. Combined evidence that the behaviours of both species in this predator-prey relationship are altered by elevated CO2 suggests food web interactions and ecosystem structure will become increasingly difficult to predict as ocean acidification advances over coming decades. © 2017 The Author(s).

  15. Development of a Method to Extract and Amplify the Complete Mitogenome of Some Sparidae Species

    PubMed Central

    Mascolo, Celestina; Ceruso, Marina; Sordino, Paolo; Palma, Giuseppe; Anastasio, Aniello; Pepe, Tiziana

    2017-01-01

    Previous studies showed that fish mitochondrial DNA (mtDNA) is set up by a closed circular molecule of 16-17 kilobases (kb), comprising 2 ribosomal RNA genes (rRNA), 22 transfer RNA genes (tRNA), 13 protein-coding genes and 2 non-coding regions. The analysis of single mtDNA genes, such as Cytb, COI, 16S and 12S, or short segment of them, has been widely used against species substitution in both fresh and processed fish products. The analysis of the complete mitochondrial genome of fishery products allows to better study and characterise fish species. The aim of this research was to extract and amplify the complete mtDNA of some fish species of commercial interest belonging to the Sparidae family. The studied species were Dentex dentex, Dentex gibbosus, Dentex nufar, Pagellus acarne and Pagellus erythrinus. The entire mitogenome was obtained by gene amplification using long polymerase chain reactions. The analysis of the complete mitochondrial sequences will allow to gain further insights on these species and to find polymorphic sites that assess the degree of genetic variability of the species belonging to the family Sparidae. PMID:28713786

  16. Effects of a non-native cichlid fish (African jewelfish, Hemichromis letourneuxi Sauvage 1880) on a simulated Everglades aquatic community

    USGS Publications Warehouse

    Schofield, Pamela J.; Slone, Daniel H.; Gregoire, Denise R.; Loftus, William F.

    2014-01-01

    In an 8-month mesocosm experiment, we examined how a simulated Everglades aquatic community of small native fishes, snails, and shrimp changed with the addition of either a native predator (dollar sunfish Lepomis marginatus) or a non-native predator (African jewelfish Hemichromis letourneuxi) compared to a no-predator control. Two snail species (Planorbella duryi, Physella cubensis) and the shrimp (Palaemonetes paludosus) displayed the strongest predator-treatment effects, with significantly lower biomasses in tanks with Hemichromis. One small native fish (Heterandria formosa) was significantly less abundant in Hemichromis tanks, but there were no significant treatment effects for Gambusia holbrooki, Jordanella floridae, or Pomacea paludosa (applesnail). Overall, there were few treatment differences between native predator and no-predator control tanks. The results suggest that the potential of Hemichromis to affect basal food-web species that link primary producers with higher-level consumers in the aquatic food web, with unknown consequences for Florida waters.

  17. Effects of increased feeding frequency on growth of hybrid bluegill in ponds

    USGS Publications Warehouse

    Sager, C.R.; Winkelman, D.L.

    2006-01-01

    Increased feeding frequency has been used in aquaculture to increase growth and food conversion efficiency, and recent laboratory studies have indicated that feeding frequency could be used to reduce the size variation within groups of hybrid bluegills (F1: male bluegill Lepomis macrochirus x female green sunfish L. cyanellus). Our experiment evaluated the growth of pond-reared hybrid bluegills fed equal amounts of food either once or four times per day. We were particularly interested in reducing the size variation and increasing the percentage of harvestable-size fish (???110 g). After 194 d, there was no significant effect of feeding frequency on growth, food conversion efficiency, size variation, or percentage of harvestable-size fish.

  18. Individual-based model of bluegill sunfish production in aquatic mesocosms/microcosms

    SciTech Connect

    Florian, J.D. Jr.; Dixon, K.R.; DeAngelis, D.L.; Shaw, J.L.

    1994-12-31

    The development of an individual-based model for ag-ill sunfish, Lepomis macrochirus (Rafinesque) is described. Fish are modeled as an assemblage of individuals. Foraging, bioenergetics, interactions with conspecifics, and reproduction are modeled separately for each fish using control data from aquatic mesocosm/microcosm studies. The individual behavior of each fish is described by decision rules which specify what particular actions the fish performs on a daily basis. A summary of the most important behavioral rules for the model and how physical and resource environments can be taken into account is presented. Development of this type of modeling is pursued for ultimate use in field situations to better understand the influences of natural environmental conditions versus toxicant exposures on populations of fish through time.

  19. Responses of bluegills and black crappies to dissolved oxygen, temperature, and current in backwater lakes of the upper Mississippi River during winter

    USGS Publications Warehouse

    Knights, B.C.; Johnson, B.L.; Sandheinrich, M.B.

    1995-01-01

    We conducted a radiotelemetry study to examine the effects of dissolved oxygen (DO), water temperature, and current velocity on winter habitat selection by bluegills Lepomis macrochirus and black crappies Pomoxis nigromaculatus in the Finger Lakes backwater complex, Pool 5, on the upper Mississippi River. When DO was above 2 mg/L, both species selected areas with water temperature greater than 1 degree C and undetectable current. As dissolved oxygen concentrations fell below 2 mg/L, fish moved to areas with higher DO, despite water temperatures of 1 degree C and lower and current velocities of 1 cm/s. Areas with water temperature less than 1 degree C and current velocity greater than 1 cm/s were avoided. To incorporate the winter habitat requirements of bluegills and black crappies into habitat restoration projects, we recommend designs that allow the inflow of oxygenated water to maintain adequate DO without substantially decreasing temperature and increasing current velocity.

  20. Reproductive biology and juvenile recruitment of the shinyrayed pocketbook, Lampsilis subangulata (Bivalvia: Unionidae) in the Gulf Coastal Plain

    USGS Publications Warehouse

    O'Brien, C. A.; Brim-Box, J.

    1999-01-01

    The reproductive biology, glochidial morphology and recruitment of the federally endangered shinyrayed pocketbook, Lampsilis subangulata, were studied from May 1995 to July 1996 in the Flint River system, Georgia. Gravid female L. subangulata were found nine months of the year. On 19 May 1995, a L. subangulata was discovered releasing a superconglutinate, the first record confirming that this species used this specialized reproductive strategy. Superconglutinate release occurred from late May to mid-July in water temperatures ranging from 20.0 to 23.5 C. Laboratory experiments indicated that two fish species served as primary hosts, the spotted bass (Micropterus punctulatus) and largemouth bass (M. salmoides). Secondary host fish included the eastern mosquitofish (Gambusia holbrooki), guppy (Poecilia reticulata) and bluegill (Lepomis macrochirus). The glochidial morphology of L. subangulata was similar to other lampsiline species. Using quantitative survey methods, no evidence of recent juvenile recruitment was found in the largest known extant L. subangulata population.

  1. Diet overlap of introduced rainbow trout and three native fishes in an Ozark stream

    USGS Publications Warehouse

    Fenner, D.B.; Walsh, M.G.; Winkelman, D.L.

    2005-01-01

    Private angling groups in Oklahoma have requested permission to stock rainbow trout Oncorhynchus mykiss into streams of northeastern Oklahoma although little is known regarding interactions between introduced rainbow trout and native fishes in these systems. Our study objectives were to assess diet overlap between introduced rainbow trout and native smallmouth bass Micropterus dolomieu, shadow bass Ambloplites ariommus, and bluegill sunfish Lepomis macrochirus in Brush Creek, Oklahoma, a small spring-fed Ozark stream. Rainbow trout diet composition differed from that of all three native fishes in the 2 months of comparison (March and May 2001), and rainbow trout diets contained relatively low numbers of prey. It is unlikely that exploitative competition for food resources occurred between rainbow trout and these three native fishes. ?? 2004 by the American Fisheries Society.

  2. Teratogenic effects and monetary cost of selenium poisoning of fish in Lake Sutton, North Carolina.

    PubMed

    Lemly, A Dennis

    2014-06-01

    Selenium pollution from coal ash wastewater was investigated in Lake Sutton, NC. This lake has been continuously used as a cooling pond for a coal-fired power plant since 1972. Historic and recent levels of contamination in fish tissues (14-105µg Se/g dry weight in liver, 24-127 in eggs, 4-23 in muscle, 7-38 in whole-body) exceeded toxic thresholds and teratogenic effects were observed in fish collected in 2013. A high proportion (28.9 percent) of juvenile Lepomis spp. exhibited spinal and craniofacial malformations that were consistent with selenium poisoning. Teratogenic Deformity Index values indicated population-level impacts on the fishery. The partially monetized cost of resultant fishery losses was calculated at over $US 8.6 million annually, and over $US 217 million for the entire period of damage, which dates back to 1987 when chemical and biological monitoring began.

  3. Laboratory studies of the effects of pressure and dissolved gas supersaturation on turbine-passed fish

    SciTech Connect

    Abernethy, C. S.; Amidan, B. G.; Cada, G. F.

    2001-03-01

    Designing advanced turbine systems requires knowledge of environmental conditions that injure or kill fish such as the stresses associated with hydroelectric power production, including pressure changes fish experience during turbine passage and dissolved gas supersaturation (resulting from the release of water from the spillway). The objective of this study was to examine the relative importance of pressure changes as a source of turbine-passage injury and mortality. Specific tests were designed to quantify the response of fish to rapid pressure changes typical of turbine passage, with and without the complication of the fish being acclimated to gas supersaturated water. The study investigated the responses of rainbow trout (Oncorhynchus mykiss), chinook salmon (O. tshawytscha), and bluegill sunfish (Lepomis macrochirus) to these two stresses, both singly and in combination.

  4. Some enzymatic properties of brain Acetylcholinesterase from bluegill and channel catfish

    USGS Publications Warehouse

    Hogan, James W.; Knowles, Charles O.

    1968-01-01

    Using a manometric technique an acetylcholinesterase (EC 3.1.1.7, acetylcholine acetyl-hydrolase) was demonstrated in brain tissue from the bluegill, Lepomis macrochirus Rafinesque, and the channel catfish, Ictalurus punctatus (Walbaum). The activities were 19 and 37 μmoles acetylcholine hydrolyzed/milligram protein per hour for the bluegill and channel catfish enzymes, respectively. The optimum substrate concentration for the hydrolysis of acetylcholine was 10 mMfor the enzymes from both species. Generally, the catfish acetylcholinesterase was somewhat more susceptible than the bluegill to the inhibitors tested; however, the bluegill enzyme was more susceptible to inhibition by malathion and malaoxon.

  5. Behavioural interaction between fish predators and their prey: effects of plant density

    USGS Publications Warehouse

    Savino, Jacqueline F.; Stein, Roy A.

    1989-01-01

    Prey-specific anti-predatory behaviour under different degrees of structural complexity determines foraging success of predators. The behaviour of piscivorous fish (largemouth bass, Micropterus salmoides and northern pike, Esox lucius) and their prey (bluegills, Lepomis macrochirus, and fathead minnows, Pimephales promelas) were quantified in 60-min experiments in laboratory pools (2 multiplied by 4 m in diameter, 0 multiplied by 5 m deep) with artificial vegetation at densities of 0, 50, 250, and 1000 stems/m2. Largemouth bass switched predatory tactics from searching to ambushing as plant density increased whereas northern pike always used ambushing. At high plant density, both predators captured minnows, but not bluegills. Bluegills modified their behaviour more than minnows in response to predators, thereby avoiding predation at high plant densities. Structural complexity alone did not always provide refuge for prey; prey must use the structure to avoid predators. Predators may seek vegetated areas if appropriate, vulnerable prey are present.

  6. Behavior of fish predators and their prey: habitat choice between open water and dense vegetation

    USGS Publications Warehouse

    Savino, Jacqueline F.; Stein, Roy A.

    1989-01-01

    Behavior of largemouth bass, Micropterus salmoides, and northern pike, Esox lucius, foraging on fathead minnows, Pimephales promelas, or bluegills, Lepomis macrochirus, was quantified in pools with 50% cover (half the pool had artificial stems at a density of 1000 stems m−2). Both predators spent most of their time in the vegetation. Largemouth bass searched for bluegills and ambushed minnows, whereas the relatively immobile northern pike ambushed all prey. Minnows were closer to predators and were captured more frequently than bluegills. Even when minnows dispersed, they moved continually and eventually wandered within striking distance of a predator. Bluegills dispersed in the cover with predators. Bass captured the few bluegills that strayed into the open and pike captured those that approached too closely in the cover. The ability of predators to capture prey while residing in habitats containing patches of dense cover may explain their residence in areas often considered to be poor ones for foraging.

  7. Host fish suitability for glochidia of Ligumia recta

    USGS Publications Warehouse

    Khym, J.R.; Layzer, J.B.

    2000-01-01

    In the early 1900s several hosts were identified for the black sandshell Ligumia recta. Recent attempts to propagate juvenile L. recta with two of the reported hosts (bluegill Lepomis macrochirus and largemouth bass Micropterus salmoides) have produced inconsistent results and few juveniles. We conducted this study to determine which of the reported hosts or other fish hosts were the most suitable for glochidial metamorphosis. The duration of glochidial metamorphosis varied among seasons. Despite similar water temperatures, juveniles metamorphosed sooner and over a shorter period of time in the spring than early fall; the modal day of metamorphosis differed by 78 d. Relatively few juveniles were recovered from bluegill and largemouth bass in three trials. White crappie Pomoxis annularis and black crappie P. nigromaculatus were marginally suitable hosts. Although glochidia encysted on all hosts, >10x more juveniles metamorphosed on sauger Stizostedion canadense compared to other hosts tested.

  8. A digital underwater video camera system for aquatic research in regulated rivers

    USGS Publications Warehouse

    Martin, Benjamin M.; Irwin, Elise R.

    2010-01-01

    We designed a digital underwater video camera system to monitor nesting centrarchid behavior in the Tallapoosa River, Alabama, 20 km below a peaking hydropower dam with a highly variable flow regime. Major components of the system included a digital video recorder, multiple underwater cameras, and specially fabricated substrate stakes. The innovative design of the substrate stakes allowed us to effectively observe nesting redbreast sunfish Lepomis auritus in a highly regulated river. Substrate stakes, which were constructed for the specific substratum complex (i.e., sand, gravel, and cobble) identified at our study site, were able to withstand a discharge level of approximately 300 m3/s and allowed us to simultaneously record 10 active nests before and during water releases from the dam. We believe our technique will be valuable for other researchers that work in regulated rivers to quantify behavior of aquatic fauna in response to a discharge disturbance.

  9. Patterns of foraging and distribution of bluegill sunfish in a Mississippi River backwater: Influence of macrophytes and predation

    USGS Publications Warehouse

    Dewey, M.R.; Richardson, W.B.; Zigler, S.J.

    1997-01-01

    We studied the trophic interactions and spatial distributions of bluegills Lepomis macrochirus and largemouth bass Micropterus salmoides in a macrophyte bed in Lake Onalaska, a backwater lake in the upper Mississippi River. The diets of adult and age-0 bluegills were similar and changed seasonally probably in response to changes in life stages of macroinvertebrates (i.e. emergence of winged adults). Diets and diel patterns of abundance of bluegill suggest that age-0 and adults were feeding in the vegetated, littoral zone. Predation by age-0 largemouth bass appears to influence use of vegetated habitat by age-0 bluegills. In summer, when most age-0 bluegills were vulnerable to predation by age-0 largemouth bass, bluegill abundance was strongly correlated with vegetation biomass. In October and November, piscivory by age-0 largemouth bass was limited by gape. Consequently, the relationship between the abundance of age-0 bluegills and vegetation biomass was weakened because predation risk by age-0 largemouth bass was reduced.

  10. Preference of redear sunfish on zebra mussels and rams-horn snails

    USGS Publications Warehouse

    French, John R. P.; Morgan, Michael N.

    1995-01-01

    We tested prey preferences of adult (200- to 222-mm long) redear sunfish (Lepomis microlophus) on two size classes of zebra mussels (Dreissena polymorpha) and two-ridge rams-horns (Helisoma anceps) in experimental aquaria. We also tested physical limitations on consuming these mollusks and determined prey bioenergetic profitability. Redear sunfish strongly preferred rams-horns over zebra mussels, but they displayed no size preference for either prey. Ingestion was not physically limited since both prey species up to 15-mm long fit within the pharyngeal gapes of redear sunfish. Rams-horns were more bioenergetically profitable than zebra mussels and ingestion of rams-horn shell fragments was about three times less than zebra mussels. Rams-horns were somewhat more resistant to shell-crushing, but all size ranges of both prey species tested were crushable by redear sunfish. These studies suggested that the redear sunfish should not be considered a panacea for biological control of zebra mussels.

  11. The effect of fixative on total length of small-bodied stream fishes

    USGS Publications Warehouse

    Brinkley, P.D.; Fischer, John R.; Paukert, C.P.

    2008-01-01

    Longnose dace (Rhinichthys cataractae), red shiner (Cyprinella lutrensis), and green sunfish (Lepomis cyanellus) were fixed in 5% and 10% formalin and 70% and 95% ethyl alcohol to determine fixative effects on total length (TL). Total length reduced over the first 24h for all species (P<0.0001) but then stabilized. Longnose dace and green sunfish TL reduction was less for 5% formalin than for either 70% or 95% ethanol (both P<0.0001), whereas the fixative solution had no effect on red shiner TL (P=0.347). A greater percentage of change in TL was observed in green sunfish and red shiner than in longnose dace, suggesting that body form (compressiform vs. fusiform) may affect shrinkage rate among adult stream fishes.

  12. Redescription of Myxobolus paralintoni (Myxosporea:Myxobolidae), with notes regarding new host and locality.

    PubMed

    Hayden, K J; Rogers, W A

    1997-04-01

    Myxobolus paralintoni Li and Desser, 1985, is redescribed from infected cardiac tissue of redbreast sunfish. Lepomis auritus Linnaeus, from the Potomac River in Montgomery County, Maryland. Mature and developing spores were contained within trophozoites from the collagenous connective tissues of the bulbus arteriosus. Two distinct trophozoites types were found; a thick-walled cyst and a relatively thin-walled "compartmentalized" cyst. Mature spores measure 11.7 13.5 microns in length and 9.0-10.6 microns in width. Polar capsule length and width are 4.5-6.5 microns and 2.7-3.8 microns, respectively, with no intercapsular process present. The sutural ridge had 8-11 triangular folds and the sporoplasm contained a large iodinophilous vacuole. Spores of M. paralintoni are compared with other morphologically similar species of Myxobolus reported from North America.

  13. Linear and nonlinear models for predicting fish bioconcentration factors for pesticides.

    PubMed

    Yuan, Jintao; Xie, Chun; Zhang, Ting; Sun, Jinfang; Yuan, Xuejie; Yu, Shuling; Zhang, Yingbiao; Cao, Yunyuan; Yu, Xingchen; Yang, Xuan; Yao, Wu

    2016-08-01

    This work is devoted to the applications of the multiple linear regression (MLR), multilayer perceptron neural network (MLP NN) and projection pursuit regression (PPR) to quantitative structure-property relationship analysis of bioconcentration factors (BCFs) of pesticides tested on Bluegill (Lepomis macrochirus). Molecular descriptors of a total of 107 pesticides were calculated with the DRAGON Software and selected by inverse enhanced replacement method. Based on the selected DRAGON descriptors, a linear model was built by MLR, nonlinear models were developed using MLP NN and PPR. The robustness of the obtained models was assessed by cross-validation and external validation using test set. Outliers were also examined and deleted to improve predictive power. Comparative results revealed that PPR achieved the most accurate predictions. This study offers useful models and information for BCF prediction, risk assessment, and pesticide formulation. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. Diet of double-crested cormorants wintering in Texas

    USGS Publications Warehouse

    Campo, J.J.; Thompson, B.C.; Barron, J.C.; Telfair II, R. C.; Durocher, P.; Gutreuter, S.

    1993-01-01

    The diets of 420 Double-crested Cormorants (Phalacrocorax auritus) were studied during November 1986-March 1987 on eight public reservoirs in Texas. Prey included 29 fish species and the mean live weight of fish per bird was 122 g. Fishes a??415 mm long were ingested, but those a??125 mm accounted for 90% of cormorant food contents by number. Shad (Dorosoma spp.) and sunfishes (Lepomis spp.) accounted for 90% of the total food items by number. Consumption of fishes (percent by weight) was different for male vs. female and adult vs. juvenile cormorants. Total consumption of fish by weight was consistent throughout the period; however, fewer but much larger fish were consumed after 15 February. Cormorants ate fishes that were most abundant in reservoirs. Sport fishes made up a substantial portion of cormorant food by weight, but not by number on some reservoirs. Cormorants ate very few large sport fish, however.

  15. Habitat Suitability Index Models: Bluegill

    USGS Publications Warehouse

    Stuber, Robert J.; Gebhart, Glen; Maughan, O. Eugene

    1982-01-01

    A literature review encompassing habitat and species characteristics of the bluegill (Lepomis macrochirus) is followed by a discussion of the relationship of habitat variables and life requisites of this species. These data re then incorporated into Habitat Suitability Index models for the bluegill. This is one in a series of publications describing habitat requirements of selected fish and wildlife species. Numerous literature sources have been consulted in an effort to consolidate scientific data on species habitat relationships. These data have subsequently been synthesized into Habitat Suitability Index (HSI) models. the models are based on suitability indices formulated for variables found to affect the life cycle and survival of the species. The models are designed to be modified to evaluate specific habitat alterations using the HSI model building techniques presented in the U.S. Fish and Wildlife Service's Habitat Evaluation Procedures.

  16. Bioenergetic relations in submerged aquatic vegetation: An experimental test of prey use by juvenile bluegills

    USGS Publications Warehouse

    Richardson, W.B.; Zigler, S.J.; Dewey, M.R.

    1998-01-01

    We experimentally tested the hypotheses that bluegills in vegetated habitats grow more rapidly than in nonvegetated habitats because (1) vegetated habitats contain a greater caloric density and (2) are less susceptible to energetic depletion. The 10-week experiment was conducted in enclosures containing factorial combinations of the presence or absence of Vallisneria americana and juvenile bluegills Lepomis macrochirus. After 6 weeks, Vallisneria-only treatments contained a mean of 1048 cal/m2 in the benthos, whereas treatments with both Vallisneria and bluegills contained 610 cal/m2. Hyalella azteca, a preferred prey of bluegill, were nearly depleted in nonvegetated enclosures, whereas Hyalella densities in enclosures with Vallisneria were much less effected by fish. Bluegill growth was significantly greater with Vallisneria than without but declining water temperatures after week 6 resulted in slower growth despite abundant prey. Ultimately, growth of bluegill resulted from an interaction between availability and ingestion of prey, and water temperature. ?? Munksgaard, 1998.

  17. Effects of fish predation on invertebrates associated with a macrophyte in Lake Onalaska, Wisconsin

    USGS Publications Warehouse

    Chilton, E.W.; Margraf, F.J.

    1990-01-01

    We tested the effects of fish predation on the macroinvertebrates associated with Vallisneria americana (Michx) by using enclosure/exclosure experiments in lake Onalaska, Wisconsin. Four treatments were used: open water (cageless) controls, cage-effect controls (partially enclosed cages), exclosures (all fish removed), and enclosures (cages stocked with a known density of bluegills Lepomis macrochirus, Rafinesque). Bluegill predation at the density tested (one 70 mm fish per 0.37m2) did not depress Vallisneria associated invertebrate density. Mean invertebrate abundance and biomass (number and dry weight of invertebrates per g dry plant weight) increased in both exclosures and enclosures relative to open water controls. The most likely explanation is that the cages excluded some vertebrate predator(s) from those two treatments and decreased predation pressure within the cages. Large invertebrates, such as Hyalella azteca, Enallagma sp., Gyraulus sp., and Physa sp., increased in abundance within cages, whereas, small invertebrates such as chironomid larvae decreased in abundance.

  18. Fishes and habitat characteristics of the Keya Paha River, South Dakota-Nebraska

    USGS Publications Warehouse

    Harland, B.; Berry, C.R.

    2004-01-01

    Fishes were collected in four mainstem reaches and eight tributary reaches in the Keya Paha River basin during May and June 2002. Most reaches were characteristically run habitats with sand substrates and riparian pastures. Data were combined with historical records to construct a basin-wide ichthyofaunal list which comprised 38 species from seven families. Dominant species were sand shiners (Notropis ludibundus; 47%), red shiners (Cyprinella lutrensis; 37%), and brassy minnows (Hybognathus hankinsoni; 8%). Dominant game species were bluegill (Lepomis machrochirus) and channel catfish (Ictalurus punctatus). We found one species previously listed as rare in South Dakota - plains topminnow (Fundulus sciadicus), and four species not previously found in the Keya Paha River - silver chub (Macrhybopsis storeriana), river carpsucker (Carpiodes carpio), northern pike (Esox Indus), yellow perch (Perca flavescens).

  19. Relating fish health and reproductive metrics to contaminant bioaccumulation at the Tennessee Valley Authority Kingston coal ash spill site

    DOE PAGES

    Pracheil, Brenda M.; Marshall Adams, S.; Bevelhimer, Mark S.; ...

    2016-05-06

    A 4.1 million m3 release of coal ash into the Emory and Clinch rivers in December 2008 at Tennessee Valley Authority s Kingston Fossil Plant has prompted a long-term, large-scale biological monitoring effort to determine if there are chronic effects of this spill on biota. Of concern in this spill were arsenic (As) and selenium (Se), heavy metal constituents of coal ash that can be toxic to fish and wildlife and also mercury (Hg): a legacy contaminant that can interact with Se in organisms. We used fish filet bioaccumulation data from Bluegill Lepomis macrochirus, Redear Lepomis microlophus, Largemouth Bass Micropterusmore » salmoides and Channel Catfish Ictalurus punctatus and metrics of fish health including fish condition indices, blood chemistry parameters and liver histopathology data collected from 2009-2013 to determine whether tissue heavy metal burdens relate 1) to each other 2) to metrics of fish health (e.g., blood chemistry characteristics and liver histopathology) and condition, and 3) whether relationships between fish health characteristics and heavy metals are related to site and ash-exposure. We found that burdens of Se and As are generally related to each other between tissues, but burdens of Hg between tissues are not generally positively associated. Taking analyses together, there appears to be reductions in growth and sublethal liver and kidney dysfunction in Bluegill and Largemouth Bass as indicated by blood chemistry parameters (elevated blood protein, glucose, phosphorous, blood urea nitrogen and creatinine in ash-affected sites) and related to concentrations of As and Se. Seeing sub-lethal effects in these species of fish is interesting because Redear had the highest filet burdens of Se, but did not have biomarkers indicating disease or dysfunction. We conclude our study by highlighting the complexities inherent in multimetric fish health data and the need for continued monitoring to further untangle contaminant and fish health

  20. Relating fish health and reproductive metrics to contaminant bioaccumulation at the Tennessee Valley Authority Kingston coal ash spill site

    SciTech Connect

    Pracheil, Brenda M.; Marshall Adams, S.; Bevelhimer, Mark S.; Fortner, Allison M.; Greeley, Mark S.; Murphy, Cheryl A.; Mathews, Teresa J.; Peterson, Mark J.

    2016-05-06

    A 4.1 million m3 release of coal ash into the Emory and Clinch rivers in December 2008 at Tennessee Valley Authority s Kingston Fossil Plant has prompted a long-term, large-scale biological monitoring effort to determine if there are chronic effects of this spill on biota. Of concern in this spill were arsenic (As) and selenium (Se), heavy metal constituents of coal ash that can be toxic to fish and wildlife and also mercury (Hg): a legacy contaminant that can interact with Se in organisms. We used fish filet bioaccumulation data from Bluegill Lepomis macrochirus, Redear Lepomis microlophus, Largemouth Bass Micropterus salmoides and Channel Catfish Ictalurus punctatus and metrics of fish health including fish condition indices, blood chemistry parameters and liver histopathology data collected from 2009-2013 to determine whether tissue heavy metal burdens relate 1) to each other 2) to metrics of fish health (e.g., blood chemistry characteristics and liver histopathology) and condition, and 3) whether relationships between fish health characteristics and heavy metals are related to site and ash-exposure. We found that burdens of Se and As are generally related to each other between tissues, but burdens of Hg between tissues are not generally positively associated. Taking analyses together, there appears to be reductions in growth and sublethal liver and kidney dysfunction in Bluegill and Largemouth Bass as indicated by blood chemistry parameters (elevated blood protein, glucose, phosphorous, blood urea nitrogen and creatinine in ash-affected sites) and related to concentrations of As and Se. Seeing sub-lethal effects in these species of fish is interesting because Redear had the highest filet burdens of Se, but did not have biomarkers indicating disease or dysfunction. We conclude our study by highlighting the complexities inherent in multimetric fish health data and the need for continued monitoring to further untangle contaminant and fish health

  1. Variation in predation pressure as a mechanism underlying differences in numerical abundance between populations of the poeciliid fish Heterandria formosa

    USGS Publications Warehouse

    Richardson, J.M.L.; Gunzburger, M.S.; Travis, J.

    2006-01-01

    We explored whether a variation in predation and habitat complexity between conspecific populations can drive qualitatively different numerical dynamics in those populations. We considered two disjunct populations of the least killifish, Heterandria formosa, that exhibit long-term differences in density, top fish predator species, and dominant aquatic vegetation. Monthly censuses over a 3-year period found that in the higher density population, changes in H. formosa density exhibited a strong negative autocorrelation structure: increases (decreases) at one census tended to be followed by decreases (increases) at the next one. However, no such correlation was present in the lower density population. Monthly census data also revealed that predators, especially Lepomis sp., were considerably more abundant at the site with lower H. formosa densities. Experimental studies showed that the predation by Lepomis gulosus occurred at a much higher rate than predation by two other fish and two dragonfly species, although L. gulosus and L. punctatus had similar predation rates when the amount of vegetative cover was high. The most effective predator, L. gulosus, did not discriminate among life stages (males, females, and juveniles) of H. formosa. Increased predation rates by L. gulosus could keep H. formosa low in one population, thereby eliminating strong negative density-dependent regulation. In support of this, changes in H. formosa density were positively correlated with changes in vegetative cover for the population with a history of lower density, but not for the population with a history of higher density. Our results are consistent with the hypothesis that the observed differences among natural populations in numerical abundance and dynamics are caused in part by the differences in habitat complexity and the predator community. ?? Springer-Verlag 2005.

  2. Relating fish health and reproductive metrics to contaminant bioaccumulation at the Tennessee Valley Authority Kingston coal ash spill site

    SciTech Connect

    Pracheil, Brenda M.; Marshall Adams, S.; Bevelhimer, Mark S.; Fortner, Allison M.; Greeley, Mark S.; Murphy, Cheryl A.; Mathews, Teresa J.; Peterson, Mark J.

    2016-05-06

    A 4.1 million m3 release of coal ash into the Emory and Clinch rivers in December 2008 at Tennessee Valley Authority s Kingston Fossil Plant has prompted a long-term, large-scale biological monitoring effort to determine if there are chronic effects of this spill on biota. Of concern in this spill were arsenic (As) and selenium (Se), heavy metal constituents of coal ash that can be toxic to fish and wildlife and also mercury (Hg): a legacy contaminant that can interact with Se in organisms. We used fish filet bioaccumulation data from Bluegill Lepomis macrochirus, Redear Lepomis microlophus, Largemouth Bass Micropterus salmoides and Channel Catfish Ictalurus punctatus and metrics of fish health including fish condition indices, blood chemistry parameters and liver histopathology data collected from 2009-2013 to determine whether tissue heavy metal burdens relate 1) to each other 2) to metrics of fish health (e.g., blood chemistry characteristics and liver histopathology) and condition, and 3) whether relationships between fish health characteristics and heavy metals are related to site and ash-exposure. We found that burdens of Se and As are generally related to each other between tissues, but burdens of Hg between tissues are not generally positively associated. Taking analyses together, there appears to be reductions in growth and sublethal liver and kidney dysfunction in Bluegill and Largemouth Bass as indicated by blood chemistry parameters (elevated blood protein, glucose, phosphorous, blood urea nitrogen and creatinine in ash-affected sites) and related to concentrations of As and Se. Seeing sub-lethal effects in these species of fish is interesting because Redear had the highest filet burdens of Se, but did not have biomarkers indicating disease or dysfunction. We conclude our study by highlighting the complexities inherent in multimetric fish health data and the need for continued monitoring to further untangle contaminant and fish health

  3. Mercury and selenium in fish from the Savannah river: species, trophic level, and locational differences.

    PubMed

    Burger, J; Gaines, K F; Boring, C S; Stephens, W L; Snodgrass, J; Gochfeld, M

    2001-10-01

    Levels of contaminants in fish are of considerable interest because of potential effects on the fish themselves, as well as on other organisms that consume them. In this article we compare the mercury levels in muscle tissue of 11 fish species from the Savannah River, as well as selenium levels because of its known protective effect against mercury toxicity. We sampled fish from three stretches of the river: upstream, along, and downstream the Department of Energy's Savannah River Site, a former nuclear material production facility. We test the null hypothesis that there were no differences in mercury and selenium levels in fish tissue as a function of species, trophic level, and location along the river. There were significant interspecific differences in mercury levels, with bowfin (Amia calva) having the highest levels, followed by largemouth bass (Micropterus salmoides) and pickerel (Esox niger). Sunfish (Lepomis spp.) had the lowest levels of mercury. As expected, these differences generally reflected trophic levels. There were few significant locational differences in mercury levels, and existing differences were not great, presumably reflecting local movements of fish between the sites examined. Selenium and mercury concentrations were positively correlated only for bass, perch (Perca flavescens), and red-breasted sunfish (Lepomis auritus). Mercury levels were positively correlated with body mass of the fish for all species except American eel (Anguilla rostrata) and bluegill sunfish (L. macrochirus). The mercury and selenium levels in fish tissue from the Savannah River are similar to or lower than those reported in many other studies, and in most cases pose little risk to the fish themselves or to other aquatic consumers, although levels in bowfin and bass are sufficiently high to pose a potential threat to high-level consumers. Copyright 2001 Academic Press.

  4. Mercury in sport fish from the Sacramento-San Joaquin Delta region, California, USA.

    PubMed

    Davis, Jay A; Greenfield, Ben K; Ichikawa, Gary; Stephenson, Mark

    2008-02-25

    Total mercury (Hg) concentrations were determined in fillet tissue of sport fish captured in the Sacramento-San Joaquin River Delta and surrounding tributaries, a region particularly impacted by historic gold and mercury mining activity. In 1999 and 2000, mercury concentrations were measured in 767 samples from ten fish species. Largemouth bass (Micropterus salmoides), the primary target species, exhibited a median Hg concentration of 0.53 mug g(-1) (N=406). Only 23 largemouth bass (6%) were below a 0.12 mug g(-1) threshold corresponding to a 4 meals per month safe consumption limit. Most of the largemouth bass (222 fish, or 55% of the sample) were above a 0.47 mug g(-1) threshold corresponding to a 1 meal per month consumption limit. Striped bass (Morone saxatilis), channel catfish (Ictalurus punctatus), white catfish (Ameirus catus), and Sacramento pikeminnow (Ptychocheilus grandis) also had relatively high concentrations, with 31% or more of samples above 0.47 mug g(-1). Concentrations were lowest in redear (Lepomis microlophus) and bluegill (Lepomis macrochirus) sunfish, with most samples below 0.12 mug g(-1), suggesting that targeting these species for sport and subsistence fishing may reduce human dietary exposure to Hg in the region. An improved method of analysis of covariance was performed to evaluate spatial variation in Hg in largemouth bass captured in 2000, while accounting for variability in fish length. Using this approach, Hg concentrations were significantly elevated in the Feather River, northern Delta, lower Cosumnes River, and San Joaquin River regions. In spite of elevated Hg concentrations on all of its tributaries, the central Delta had concentrations that were low both in comparison to safe consumption guidelines and to other locations.

  5. Acute toxicity of TFM and a TFM/niclosamide mixture to selected species of fish, including lake sturgeon (Acipenser fulvescens) and mudpuppies (Necturus maculosus), in laboratory and field exposures

    USGS Publications Warehouse

    Boogaard, M.A.; Bills, T.D.; Johnson, D.A.

    2003-01-01

    The toxicity of the lampricides 3-trifluoromethyl-4-nitrophenol (TFM) and 2???,5-dichloro-4???-nitrosalicylanilide (niclosamide) to non-target fishes has been a major point of concern since their use to control larval sea lamprey (Petromyzon marinus) populations began in the early 1960s. The toxicity of TFM to several non-target fish species has been demonstrated in previous studies. However, little information is available on the toxicity of the TFM/1 % niclosamide mixture. One species of particular concern is the lake sturgeon (Acipenser fulvescens). Juvenile lake sturgeon of several size ranges were exposed to determine potential effects of the lampricides to individuals present in treatment streams. Sac fry were most resistant to the lampricides followed by fingerlings in the 200 to 225 mm size range. Swim-up fry and fingerlings less than 100 mm were the most sensitive. Concentrations that produced 50% mortality (LC50s) in juvenile lake sturgeon of these smaller size ranges were at or near the minimum lethal concentrations (MLCs) required for effective control of larval sea lampreys. The mudpuppy (Necturus maculosus), an amphibian native to several tributaries of the Great Lakes, have also become a species of interest in recent years. Laboratory tests conducted with TFM and a TFM/1 % niclosamide mixture on adult mudpuppies indicate that although the amphibian is sensitive to the lampricides, an adequate margin of safety exists for adult mudpuppies to survive when exposed during stream treatments. Fifteen other fish species native to streams treated with lampricides were investigated in the laboratory to determine their sensitivity to the lampricides. Centrarchids, bluegill (Lepomis macrochirus) and green sunfish (Lepomis cyanellus) were the least sensitive to TFM, while ictalurids, black bullhead (Ictalurus melas), channel catfish (Ictalurus punctatus), and tadpole madtom (Notorus gyrinus) were the most sensitive. On-site bioassays conducted before lampricide

  6. Acute toxicity of TFM and a TFM/niclosamide mixture to selected species of fish, including lake sturgeon (Acipenser fulvescens) and mudpuppies (Necturus maculosus), in laboratory and field exposures

    USGS Publications Warehouse

    Boogaard, M.A.; Bills, T.D.; Johnson, D.A.

    2003-01-01

    The toxicity of the lampricides 3-trifluoromethyl-4-nitrophenol (TFM) and 2',5-dichloro-4'-nitrosalicylanilide (niclosamide) to non-target fishes has been a major point of concern since their use to control larval sea lamprey (Petromyzon marinus) populations began in the early 1960s. The toxicity of TFM to several non-target fish species has been demonstrated in previous studies. However, little information is available on the toxicity of the TFM/1% niclosamide mixture. One species of particular concern is the lake sturgeon (Acipenser fulvescens). Juvenile lake sturgeon of several size ranges were exposed to determine potential effects of the lampricides to individuals present in treatment streams. Sac fry were most resistant to the lampricides followed by fingerlings in the 200 to 225 mm size range. Swim-up fry and fingerlings less than 100 mm were the most sensitive. Concentrations that produced 50% mortality (LC50s) in juvenile lake sturgeon of these smaller size ranges were at or near the minimum lethal concentrations (MLCs) required for effective control of larval sea lampreys. The mudpuppy (Necturus maculosus), an amphibian native to several tributaries of the Great Lakes, have also become a species of interest in recent years. Laboratory tests conducted with TFM and a TFM/1% niclosamide mixture on adult mudpuppies indicate that although the amphibian is sensitive to the lampricides, an adequate margin of safety exists for adult mudpuppies to survive when exposed during stream treatments. Fifteen other fish species native to streams treated with lampricides were investigated in the laboratory to determine their sensitivity to the lampricides. Centrarchids, bluegill (Lepomis macrochirus) and green sunfish (Lepomis cyanellus) were the least sensitive to TFM, while ictalurids, black bullhead (Ictalurus melas), channel catfish (Ictalurus punctatus), and tadpole madtom (Notorus gyrinus) were the most sensitive. On-site bioassays conducted before lampricide

  7. Effects of electrofishing gear type on spatial and temporal variability in fish community sampling

    USGS Publications Warehouse

    Meador, M.R.; McIntyre, J.P.

    2003-01-01

    Fish community data collected from 24 major river basins between 1993 and 1998 as part of the U.S. Geological Survey's National Water-Quality Assessment Program were analyzed to assess multiple-reach (three consecutive reaches) and multiple-year (three consecutive years) variability in samples collected at a site. Variability was assessed using the coefficient of variation (CV; SD/mean) of species richness, the Jaccard index (JI), and the percent similarity index (PSI). Data were categorized by three electrofishing sample collection methods: backpack, towed barge, and boat. Overall, multiple-reach CV values were significantly lower than those for multiple years, whereas multiple-reach JI and PSI values were significantly greater than those for multiple years. Multiple-reach and multiple-year CV values did not vary significantly among electrofishing methods, although JI and PSI values were significantly greatest for backpack electrofishing across multiple reaches and multiple years. The absolute difference between mean species richness for multiple-reach samples and mean species richness for multiple-year samples was 0.8 species (9.5% of total species richness) for backpack samples, 1.7 species (10.1%) for towed-barge samples, and 4.5 species (24.4%) for boat-collected samples. Review of boat-collected fish samples indicated that representatives of four taxonomic families - Catostomidae, Centrarchidae, Cyprinidae, and Ictaluridae - were collected at all sites. Of these, catostomids exhibited greater interannual variability than centrarchids, cyprinids, or ictalurids. Caution should be exercised when combining boat-collected fish community data from different years because of relatively high interannual variability, which is primarily due to certain relatively mobile species. Such variability may obscure longer-term trends.

  8. Baseline assessment of fish communities, benthic macroinvertebrate communities, and stream habitat and land use, Big Thicket National Preserve, Texas, 1999-2001

    USGS Publications Warehouse

    Moring, J. Bruce

    2003-01-01

    The Big Thicket National Preserve comprises 39,300 hectares in the form of nine preserve units connected by four stream corridor units (with two more corridor units proposed) distributed over the lower Neches and Trinity River Basins of southeastern Texas. Fish and benthic macroinvertebrate data were collected at 15 stream sites (reaches) in the preserve during 1999–2001 for a baseline assessment and a comparison of communities among stream reaches. The fish communities in the preserve were dominated by minnows (family Cyprinidae) and sunfishes (family Centrarchidae). Reaches with smaller channel sizes generally had higher fish species richness than the larger reaches in the Neches River and Pine Island Bayou units of the preserve. Fish communities in geographically adjacent reaches were most similar in overall community structure. The blue sucker, listed by the State as a threatened species, was collected in only one reach—a Neches River reach a few miles downstream from the Steinhagen Lake Dam. Riffle beetles (family Elmidae) and midges (family Chironomidae) dominated the aquatic insect communities at the 14 reaches sampled for aquatic insects in the preserve. The Ephemeroptera, Plecoptera and Trichoptera (EPT) Index, an index sensitive to water-quality degradation, was smallest at the Little Pine Island Bayou near Beaumont reach that is in a State 303(d)-listed stream segment on Little Pine Island Bayou. Trophic structure of the aquatic insect communities is consistent with the river continuum concept with shredder and scraper insect taxa more abundant in reaches with smaller stream channels and filter feeders more abundant in reaches with larger channels. Aquatic insect community metrics were not significantly correlated to any of the stream-habitat or land-use explanatory variables. The percentage of 1990s urban land use in the drainage areas upstream from 12 bioassessment reaches were negatively correlated to the reach structure index, which indicates

  9. Exposure of great egret (Ardea albus) nestlings to mercury through diet in the Everglades ecosystem

    SciTech Connect

    Frederick, P.C.; Spalding, M.G.; Sepulveda, M.S.; Williams, G.E.; Nico, L.; Robins, R.

    1999-09-01

    The authors estimated exposure of great egret (Ardea albus) nestlings to mercury in food in the Florida Everglades, USA, by collecting regurgitated food samples during the 1993 to 1996 breeding seasons and during 1995 measured concentrations of mercury in individual prey items from those samples. Great egret nestlings had a diet composed predominantly of fish, though the species composition of fish in the diet fluctuated considerably among years. Great egrets concentrated on the larger fish available in the marsh, especially members of the Centrarchidae. The importance of all nonnative fish fluctuated from 0 to 32% of the diet by biomass and was dominated by pike killifish (Belonesox belizanus) and cichlids (Cichlidae). Total mercury concentrations in prey fish ranged from 0.04 to 1.40 mg/kg wet weight, and they found a significant relationship between mass of individual fish and mercury concentration. The authors estimated the concentration of total mercury in the diet as a whole by weighting the mercury concentration in a given fish species by the proportion of that species in the diet. They estimate that total mercury concentrations in the diets ranged among years from 0.37 to 0.47 mg/kg fish. The authors estimated total mercury exposure in great egret nestlings by combining these mercury concentrations with measurements of food intake rate, as measured over the course of the nestling period in both lab and field situations. They estimate that, at the 0.41 mg/kg level, nestlings would ingest 4.32 mg total mercury during an 80-day nestling period. Captive feeding studies reported elsewhere suggest that this level of exposure in the wild could be associated with reduced fledgling mass, increased lethargy, decreased appetite, and, possibly, poor health and juvenile survival.

  10. Marine and inland fishes of St. Croix, U. S. Virgin Islands: an annotated checklist

    USGS Publications Warehouse

    Smith-Vaniz, William F.; Jelks, Howard L.

    2014-01-01

    An historical account is given for the ichthyological research at St. Croix, U. S. Virgin Islands, followed by an annotated list of 544 species of mostly marine shore fishes known or reported from the island to depths of 200 m. Color photographs are included for 103 of these species. Collections made at Buck Island Reef National Monument with the ichthyocide rotenone in 2001 and 2005 increased the known ichthyofauna by about 80 species. The rational for inclusion of each species in the checklist is given, with remarks for those species for which additional documentation or voucher specimens are needed. Reports of species known or presumed to have been based on misidentifications are discussed. Of the total marine fish fauna of the island, 404 species (75%) are restricted to the western Atlantic Ocean, (223 of these species are essentially Caribbean endemics that do not occur south of the Amazon River outflow), and no St. Croix endemic species are known. An additional 17 species (3.2%) also occur at mid-Atlantic islands, 57 species (10.6 %) are limited to both sides of the Atlantic Ocean, and 40 species (7.4%) have circumtropical distributions. The four most species-rich families are the Gobiidae (47 species), Serranidae (groupers and sea basses, 41), Labridae (wrasses and parrotfishes, 31), and Labrisomidae (scaly blennies, 27). Literature reports of Mosquitofish, Gambusia sp., from St. Croix apparently were based on misidentifications of a different introduced poeciliid genus. Four species of the amphidromus goby genus Sicydium occur in St. Croix inland waters, together with three established introduced species (one cichlid and two poeciliids). Also included are one catfish (Ictaluridae) and three sunfishes (Centrarchidae) known only from ponds. The Lionfish, Pterois volitans, the only introduced marine species, was first reported from St. Croix in 2008 and is now common despite control efforts.

  11. Marine and inland fishes of St. Croix, U. S. Virgin Islands: an annotated checklist.

    PubMed

    Smith-Vaniz, William F; Jelks, Howard L

    2014-05-29

    An historical account is given for the ichthyological research at St. Croix, U. S. Virgin Islands, followed by an annotated list of 544 species of mostly marine shore fishes known or reported from the island to depths of 200 m. Color photographs are included for 103 of these species. Collections made at Buck Island Reef National Monument with the ichthyocide rotenone in 2001 and 2005 increased the known ichthyofauna by about 80 species. The rational for inclusion of each species in the checklist is given, with remarks for those species for which additional documentation or voucher specimens are needed. Reports of species known or presumed to have been based on misidentifications are discussed. Of the total marine fish fauna of the island, 404 species (75%) are restricted to the western Atlantic Ocean, (223 of these species are essentially Caribbean endemics that do not occur south of the Amazon River outflow), and no St. Croix endemic species are known. An additional 17 species (3.2%) also occur at mid-Atlantic islands, 57 species (10.6 %) are limited to both sides of the Atlantic Ocean, and 40 species (7.4%) have circumtropical distributions. The four most species-rich families are the Gobiidae (47 species), Serranidae (groupers and sea basses, 41), Labridae (wrasses and parrotfishes, 31), and Labrisomidae (scaly blennies, 27). Literature reports of Mosquitofish, Gambusia sp., from St. Croix apparently were based on misidentifications of a different introduced poeciliid genus. Four species of the amphidromus goby genus Sicydium occur in St. Croix inland waters, together with three established introduced species (one cichlid and two poeciliids). Also included are one catfish (Ictaluridae) and three sunfishes (Centrarchidae) known only from ponds. The Lionfish, Pterois volitans, the only introduced marine species, was first reported from St. Croix in 2008 and is now common despite control efforts.

  12. Diel and distributional abundance patterns of fish embryos and larvae in the lower Columbia and Deschutes rivers

    USGS Publications Warehouse

    Gadomski, D.M.; Barfoot, C.A.

    1998-01-01

    Diel and distributional abundance patterns of free embryos and larvae of fishes in the lower Columbia River Basin were investigated. Ichthyoplankton samples were collected in 1993 during day and night in the main-channel and a backwater of the lower Columbia River, and in a tributary, the Deschutes River. Fish embryos and larvae collected in the main-channel Columbia River were primarily (85.6%) of native taxa (peamouth Mylocheilus caurinus, northern squawfish Ptychocheilus oregonensis, suckers Catostomus spp., and sculpins Cottus spp.), with two introduced species (American shad Alosa sapidissima and common carp Cyprinus carpio) comprising a smaller percentage of the catch (13.3%). Similarly, in the Deschutes River native taxa [lampreys (Petromyzontidae), minnows (Cyprinidae), and suckers Catostomus spp.] dominated collections (99.5% of the catch). In contrast, 83.5% of embryos and larvae in the Columbia River backwater were of introduced taxa [American shad, common carp, and sunfishes (Centrarchidae)]. In all locations, all dominant taxa except sculpins were collected in significantly greater proportions at night. Taxon-specific differences in proportions of embryos and larvae collected at night can in some instances be related to life history styles. In the main-channel Columbia River, northern squawfish and peamouth were strongly nocturnal and high proportions still had yolksacs, suggesting that they had recently hatched and were drifting downriver to rearing areas. In contrast, sculpin abundances were similar during day and night, and sculpins mostly had depleted yolksacs, indicating sculpins were feeding and rearing in offshore limnetic habitats. Taxon-specific diel abundance patterns and their causes must be considered when designing effective sampling programs for fish embryos and larvae.

  13. Exposure of great egret (Ardea albus) nestlings to mercury through diet in the Everglades ecosystem

    USGS Publications Warehouse

    Frederick, Peter C; Spalding, Marilyn G.; Sepalveda, Maria S.; Williams, Gary E.; Nico, Leo G.; Robins, Robert H.

    1999-01-01

    We estimated exposure of great egret (Ardea albus) nestlings to mercury in food in the Florida Everglades, USA, by collecting regurgitated food samples during the 1993 to 1996 breeding seasons and during 1995 measured concentrations of mercury in individual prey items from those samples. Great egret nestlings had a diet composed predominantly of fish (>95% of biomass), though the species composition of fish in the diet fluctuated considerably among years. Great egrets concentrated on the larger fish available in the marsh, especially members of the Centrarchidae. The importance of all nonnative fish fluctuated from 0 to 32% of the diet by biomass and was dominated by pike killifish (Belonesox belizanus) and cichlids (Cichlidae). Total mercury concentrations in prey fish ranged from 0.04 to 1.40 mg/kg wet weight, and we found a significant relationship between mass of individual fish and mercury concentration. We estimated the concentration of total mercury in the diet as a whole by weighting the mercury concentration in a given fish species by the proportion of that species in the diet. We estimate that total mercury concentrations in the diets ranged among years from 0.37 to 0.47 mg/kg fish (4-year mean = 0.41 mg/kg). We estimated total mercury exposure in great egret nestlings by combining these mercury concentrations with measurements of food intake rate, as measured over the course of the nestling period in both lab and field situations. We estimate that, at the 0.41 mg/kg level, nestlings would ingest 4.32 mg total mercury during an 80-day nestling period. Captive feeding studies reported elsewhere suggest that this level of exposure in the wild could be associated with reduced fledging mass, increased lethargy, decreased appetite, and, possibly, poor health and juvenile survival.

  14. Fish assemblages and environmental variables associated with hard-rock mining in the Coeur d'Alene River basin, Idaho

    USGS Publications Warehouse

    Maret, Terry R.; MacCoy, Dorene E.

    2002-01-01

    As part of the U.S. Geological Survey's National Water Quality Assessment Program, fish assemblages, environmental variables, and associated mine densities were evaluated at 18 test and reference sites during the summer of 2000 in the Coeur d'Alene and St. Regis river basins in Idaho and Montana. Multimetric and multivariate analyses were used to examine patterns in fish assemblages and the associated environmental variables representing a gradient of mining intensity. The concentrations of cadmium (Cd), lead (Pb), and zinc (Zn) in water and streambed sediment found at test sites in watersheds where production mine densities were at least 0.2 mines/km2 (in a 500-m stream buffer) were significantly higher than the concentrations found at reference sites. Many of these metal concentrations exceeded Ambient Water Quality Criteria (AWQC) and the Canadian Probable Effect Level guidelines for streambed sediment. Regression analysis identified significant relationships between the production mine densities and the sum of Cd, Pb, and Zn concentrations in water and streambed sediment (r2 = 0.69 and 0.66, respectively; P < 0.01). Zinc was identified as the primary metal contaminant in both water and streambed sediment. Eighteen fish species in the families Salmonidae, Cottidae, Cyprinidae, Catostomidae, Centrarchidae, and Ictaluridae were collected. Principal components analysis of 11 fish metrics identified two distinct groups of sites corresponding to the reference and test sites, predominantly on the basis of the inverse relationship between percent cottids and percent salmonids (r = -0.64; P < 0.05). Streams located downstream from the areas of intensive hard-rock mining in the Coeur d'Alene River basin contained fewer native fish and lower abundances as a result of metal enrichment, not physical habitat degradation. Typically, salmonids were the predominant species at test sites where Zn concentrations exceeded the acute AWQC. Cottids were absent at these sites, which

  15. Dispersal, vicariance, and timing of diversification in Nothonotus darters.

    PubMed

    Near, Thomas J; Keck, Benjamin P

    2005-10-01

    The species diversity of North American freshwater fishes is unparalleled among temperate regions of the planet. This diversity is concentrated in the Central Highlands of eastern North America and this distribution pattern has inspired different models involving either dispersal or vicariance to explain the high species diversity of North American fishes. The most popular of these models is the Central Highlands vicariance hypothesis (CHVH), which proposes an ancient and diverse widespread fauna that existed across a previously continuous highland landscape that is much different from today. The mechanisms of isolation in the CHVH involve specific instances of vicariance that affected several diverse lineages of Central Highlands fishes. We tested predictions of the CHVH and alternative models using a cytochrome b-inferred phylogeny of the darter clade Nothonotus. A Bayesian mixed-model method was used for phylogenetic analysis. The phylogenetic data set included all 20 recognized Nothonotus species, and most species were represented with multiple sequences. We were able to convert genetic branch lengths to absolute age using external fossil calibrations in the freshwater perciform fish clade Centrarchidae. Using a well-resolved Nothonotus phylogeny and divergence time estimates, we identify equal numbers of instances of both vicariance and dispersal among disjunct regions of the Central Highlands, biogeographic pseudocongruence, rather recent speciation in Nothonotus, and a surprisingly large amount of speciation within highland areas. With regard to Nothonotus, previous Central Highlands biogeographic models offer little in the way of providing possible mechanisms responsible for diversification in the clade. Patterns of speciation in Nothonotus are similar to those discovered in recent efforts that have included speciation as a parameter into classic models of island biogeography.

  16. Response of fishes to floodplain connectivity during and following a 500-year flood event in the unimpounded upper Mississippi River

    USGS Publications Warehouse

    Barko, V.A.; Herzog, D.P.; O'Connell, M. T.

    2006-01-01

    We examined data collected on fish assemblage structure among three differing floodplain types (broad, moderate, and narrow) during the 1993 flood in the unimpounded reach of the upper Mississippi River. This 500 year flood event provided a unique opportunity to investigate fish-floodplain function because the main river channel is otherwise typically disjunct from approximately 82% of its floodplain by an extensive levee system. Fishes were sampled during three separate periods, and 42 species of adult and young-of-the-year (YOY) fishes were captured. Analysis of similarity (ANOSIM) revealed a significant and distinguishable difference between both adult and YOY assemblage structure among the three floodplain types. Analysis of variance revealed that Secchi transparency, turbidity, water velocity, and dissolved oxygen were significantly different among the floodplain types. However, only depth of gear deployment and Secchi transparency were significantly correlated with adult assemblage structure. None of these variables were significantly correlated with YOY assemblage structure. The numerically abundant families (adult and YOY catches combined) on the floodplain included Centrarchidae, Ictularidae, and Cyprinidae. Both native and non-native fishes were captured on the floodplain, and several of the numerically abundant species that were captured on the floodplain peaked in catch-per-unit-effort 1-3 years after the 1993 flood event. This suggests that some species may have used flooded terrestrial habitat for spawning, feeding, or both. The findings from our study provide much needed insight into fish-floodplain function in a temperate, channelized river system and suggest that lateral connectivity of the main river channel to less degraded reaches of its floodplain should become a management priority not only to maintain faunal biodiversity but also potentially reduce the impacts of non-native species in large river systems.

  17. Endosymbiont dominated bacterial communities in a dwarf spider.

    PubMed

    Vanthournout, Bram; Hendrickx, Frederik

    2015-01-01

    The microbial community of spiders is little known, with previous studies focussing primarily on the medical importance of spiders as vectors of pathogenic bacteria and on the screening of known cytoplasmic endosymbiont bacteria. These screening studies have been performed by means of specific primers that only amplify a selective set of endosymbionts, hampering the detection of unreported species in spiders. In order to have a more complete overview of the bacterial species that can be present in spiders, we applied a combination of a cloning assay, DGGE profiling and high-throughput sequencing on multiple individuals of the dwarf spider Oedothorax gibbosus. This revealed a co-infection of at least three known (Wolbachia, Rickettsia and Cardinium) and the detection of a previously unreported endosymbiont bacterium (Rhabdochlamydia) in spiders. 16S rRNA gene sequences of Rhabdochlamydia matched closely with those of Candidatus R. porcellionis, which is currently only reported as a pathogen from a woodlouse and with Candidatus R. crassificans reported from a cockroach. Remarkably, this bacterium appears to present in very high proportions in one of the two populations only, with all investigated females being infected. We also recovered Acinetobacter in high abundance in one individual. In total, more than 99% of approximately 4.5M high-throughput sequencing reads were restricted to these five bacterial species. In contrast to previously reported screening studies of terrestrial arthropods, our results suggest that the bacterial communities in this spider species are dominated by, or even restricted to endosymbiont bacteria. Given the high prevalence of endosymbiont species in spiders, this bacterial community pattern could be widespread in the Araneae order.

  18. Fish assemblage responses to urban intensity gradients in contrasting metropolitan areas: Birmingham, Alabama and Boston, Massachusetts

    USGS Publications Warehouse

    Meador, M.R.; Coles, J.F.; Zappia, H.

    2005-01-01

    We examined fish assemblage responses to urban intensify gradients in two contrasting metropolitan areas: Birmingham, Alabama (BIR) and Boston, Massachusetts (BOS). Urbanization was quantified by using an urban intensity index (UII) that included multiple stream buffers and basin land uses, human population density, and road density variables. We evaluated fish assemblage responses by using species richness metrics and detrended correspondence analyses (DCA). Fish species richness metrics included total fish species richness, and percentages of endemic species richness, alien species, and fluvial specialist species. Fish species richness decreased significantly with increasing urbanization in BIR (r = -0.82, P = 0.001) and BOS (r = -0.48, P = 0.008). Percentages of endemic species richness decreased significantly with increasing urbanization only in BIR (r = - 0.71, P = 0.001), whereas percentages of fluvial specialist species decreased significantly with increasing urbanization only in BOS (r = -0.56, P = 0.002). Our DCA results for BIR indicate that highly urbanized fish assemblages are composed primarily of largescale stoneroller Campostoma oligolepis, largemouth bass Micropterus salmoides, and creek chub Semotilus atromaculatus, whereas the highly urbanized fish assemblages in BOS are dominated by yellow perch Perca flavescens, bluegill Lefomis macrochirus, yellow bullhead Ameiurus natalis, largemouth bass, pumpkinseed L. gibbosus, brown bullhead A. nebulosus, and redfin pickerel Esox americanus. Differences in fish assemblage responses to urbanization between the two areas appear to be related to differences in nutrient enrichment, habitat alterations, and invasive species. Because species richness can increase or decrease with increasing urbanization, a general response model is not applicable. Instead, response models based on species' life histories, behavior, and autecologies offer greater potential for understanding fish assemblage responses to

  19. Endosymbiont Dominated Bacterial Communities in a Dwarf Spider

    PubMed Central

    Vanthournout, Bram; Hendrickx, Frederik

    2015-01-01

    The microbial community of spiders is little known, with previous studies focussing primarily on the medical importance of spiders as vectors of pathogenic bacteria and on the screening of known cytoplasmic endosymbiont bacteria. These screening studies have been performed by means of specific primers that only amplify a selective set of endosymbionts, hampering the detection of unreported species in spiders. In order to have a more complete overview of the bacterial species that can be present in spiders, we applied a combination of a cloning assay, DGGE profiling and high-throughput sequencing on multiple individuals of the dwarf spider Oedothorax gibbosus. This revealed a co-infection of at least three known (Wolbachia, Rickettsia and Cardinium) and the detection of a previously unreported endosymbiont bacterium (Rhabdochlamydia) in spiders. 16S rRNA gene sequences of Rhabdochlamydia matched closely with those of Candidatus R. porcellionis, which is currently only reported as a pathogen from a woodlouse and with Candidatus R. crassificans reported from a cockroach. Remarkably, this bacterium appears to present in very high proportions in one of the two populations only, with all investigated females being infected. We also recovered Acinetobacter in high abundance in one individual. In total, more than 99% of approximately 4.5M high-throughput sequencing reads were restricted to these five bacterial species. In contrast to previously reported screening studies of terrestrial arthropods, our results suggest that the bacterial communities in this spider species are dominated by, or even restricted to endosymbiont bacteria. Given the high prevalence of endosymbiont species in spiders, this bacterial community pattern could be widespread in the Araneae order. PMID:25706947

  20. Rates of molecular evolution in nuclear genes of east Mediterranean scorpions.

    PubMed

    Gantenbein, Benjamin; Keightley, Peter D

    2004-11-01

    Scorpions of the genus Mesobuthus represent a useful terrestrial model system for studying molecular evolution. They are distributed on several Aegean islands and the adjacent mainland, they are believed to have low rates of dispersal, and evolutionary divergence dates of taxa are available based on biogeographic events that separated islands from each other and the mainland. Here, we present data on polymorphism and synonymous (Ks) and non-synonymous (Ka) substitution rates for nine nuclear protein-coding genes of two east Mediterranean scorpion species, Mesobuthus gibbosus and M. cyprius (Buthidae). Levels of polymorphism tend to be lower in populations from islands (mean nucleotide diversity pi = 0.0071 +/- 0.0028) than in mainland populations (mean pi = 0.0201 +/- 0.0085). By using linear regression of genetic divergence versus isolation time, we estimate Ks to be 3.17 +/- 1.54 per (site x 10(9) years), and Ka to be 0.39 +/- 0.94 per (site x 10(9) years). These estimates for both Ks and Ka are considerably lower than for many other invertebrates, such as Drosophila, and may be attributed to scorpions' mammal-like generation times (approximately 2 years) and low metabolic rates. Phylogenetic analysis using maximum likelihood revealed a phylogeny that is congruent with that expected based on biogeographic events and in which divergences at synonymous sites are proportional to the dates that the taxa are believed to have split. Tests of equality of branch lengths for the Cyprus and Crete lineages revealed that Ks-estimates are about the same in both lineages, as expected from the biogeographic events that separated the islands, but Ka was increased in the Cyprus lineage compared to the Cretan lineage.

  1. New records of stink bugs (Hemiptera: Pentatomidae) from Colombia.

    PubMed

    Castro-Huertas, Valentina; Schwertner, Cristiano F; Fernández, Fernando

    2015-06-18

    New records of genera and species of stink bugs (Hemiptera: Pentatomidae) from Colombia are provided. Two genera are new records for South America: Alathetus and Schraderiellus. Fifteen genera are new record for Colombia: Agaclitus, Boea, Ceratozygum, Euthyrhynchus, Eritrachys, Doesburguedessa, Lopadusa, Marmessulus, Paralincus, Patanius, Peromatus, Phalaecus, Phoeacia, Rio, and Tyrannocoris. Forty-nine species from five subfamiles are recorded for the first time in Colombia. Asopinae: Coryzorhaphis carneolus Erichson, Coryzorhaphis superba Breddin, Euthyrhynchus floridanus (Linnaeus), Podisus sagitta Fabricius, Stiretrus anchorago (Fabricius), Stiretrus cinctellus Germar, Tylospilus peruvianus Horvath, Tyrannocoris nigriceps Thomas. Cyrtocorinae: Ceratozygum horridum (Germar). Discocephalinae: Agaclitus dromedarius Stål, Antiteuchus melanoleucus (Westwood), Antiteuchus sepulcralis (Fabricius), Dinocoris gibbosus (Fallou), Dinocoris variolosus (Linnaeus), Discocephalessa terminalis (Walker), Dryptocephala crenata Ruckes, Dryptocephala dentifrons (Latreille), Eurystethus ovalis Ruckes, Paralcippus dimidiatus (Ruckes), Alathetus rufitarsus Dallas, Eritrachys bituberculata Ruckes, Paralincus bimaculatus (Ruckes), Schraderiellus cinctus (Ruckes), Xynocoris recavus (Garbelotto & Campos). Edessinae: Brachystethus cribus (Fabricius), Brachystethus tricolor Bolívar, Doesburguedessa elongatispina Fernandes and Lopadusa fuscopunctata (Distant). Pentatominae: Banasa fulgida Thomas, Banasa paraexpallescens Thomas, Dichelops divisus (Walker), Dichelops nigrum Bergroth, Euschistus carbonerus Rolston, Mormidea bovilla (Distant), Mormidea triangularis (Walker), Murgantia bifasciata Herrich-Schaeffer, Murgantia violascens (Westwood), Oebalus pugnax (Fabricius), Oebalus ypsilon-griseus (DeGeer), Odmalea concolor (Walker), Patanius vittatus Rolston, Proxys albopunctulatus (Palisot), Proxys punctulatus (Palisot), Rhyncholepta grandicallosa Bergroth, Rio insularis Ruckes, Roferta

  2. Solving a novel confinement problem by spartaeine salticids that are predisposed to solve problems in the context of predation.

    PubMed

    Cross, Fiona R; Jackson, Robert R

    2015-03-01

    Intricate predatory strategies are widespread in the salticid subfamily Spartaeinae. The hypothesis we consider here is that the spartaeine species that are proficient at solving prey-capture problems are also proficient at solving novel problems. We used nine species from this subfamily in our experiments. Eight of these species (two Brettus, one Cocalus, three Cyrba, two Portia) are known for specialized invasion of other spiders' webs and for actively choosing other spiders as preferred prey ('araneophagy'). Except for Cocalus, these species also use trial and error to derive web-based signals with which they gain dynamic fine control of the resident spider's behaviour ('aggressive mimicry').The ninth species, Paracyrba wanlessi, is not araneophagic and instead specializes at preying on mosquitoes. We presented these nine species with a novel confinement problem that could be solved by trial and error. The test spider began each trial on an island in a tray of water, with an atoll surrounding the island. From the island, the spider could choose between two potential escape tactics (leap or swim), but we decided at random before the trial which tactic would fail and which tactic would achieve partial success. Our findings show that the seven aggressive-mimic species are proficient at solving the confinement problem by repeating 'correct' choices and by switching to the alternative tactic after making an 'incorrect' choice. However, as predicted, there was no evidence of C. gibbosus or P. wanlessi, the two non-aggressive-mimic species, solving the confinement problem. We discuss these findings in the context of an often-made distinction between domain-specific and domain-general cognition.

  3. Effects of an agricultural drainwater bypass on fishes inhabiting the Grassland Water District and the lower San Joaquin River, California

    USGS Publications Warehouse

    Saiki, M.K.; Martin, B.A.; Schwarzbach, S.E.; May, T.W.

    2001-01-01

    The Grassland Bypass Project, which began operation in September 1996, was conceived as a means of diverting brackish selenium-contaminated agricultural drainwater away from canals and sloughs needed for transporting irrigation water to wetlands within the Grassland Water District (the Grasslands), Merced County, California. The seleniferous drainwater is now routed into the San Luis Drain for conveyance to North Mud Slough and eventual disposal in the San Joaquin River. The purpose of this study was to determine the extent to which the Grassland Bypass Project has affected fishes in sloughs and other surface waters within and downstream from the Grasslands. During September-October 1997, 9,795 fish representing 25 species were captured at 13 sampling sites. Although several species exhibited restricted spatial distributions, association analysis and cluster analysis failed to identify more than one fish species assemblage inhabiting the various sites. However, seleniferous drainwater from the San Luis Drain has influenced selenium concentrations in whole fish within North Mud Slough and the San Joaquin River. The highest concentrations of selenium (12-23 ??g/g, dry weight basis) were measured in green sunfish Lepomis cyanellus from the San Luis Drain where seleniferous drainwater is most concentrated, whereas the second highest concentrations occurred in green sunfish (7.6-17 ??g/g) and bluegills Lepomis macrochirus (14-18 ??g/g) from North Mud Slough immediately downstream from the drain. Although there was some variation, fish in the San Joaquin River generally contained higher body burdens of selenium when captured immediately below the mouth of North Mud Slough (3.1-4.8 ??g/g for green sunfish, 3.7-5.0 ??g/g for bluegills) than when captured upstream from the mouth (0.67-3.3 ??g/g for green sunfish, 0.59-3.7 ??g/g for bluegills). Waterborne selenium was the single most important predictor of selenium concentrations in green sunfish and bluegills, as judged by

  4. Iron in the enameloid of perciform fish.

    PubMed

    Suga, S; Taki, Y; Ogawa, M

    1992-06-01

    It is known that a high concentration of iron is deposited in the enameloid of some teleostean fish. Previously, Suga et al. (1989) pointed out that the iron concentration in the enameloid is related to the phylogeny of fish rather than to the feeding habits, according to the results of quantitative iron analyses on the teeth of marine teleost fish of the Tetraodontiformes. In the present study, in order for the previous idea to be verified, quantitative iron analysis was made with an electron microprobe on the enameloid of fish belonging to the Perciformes, which is the largest group of teleostean fish in the world and consists of both marine and freshwater species. The enameloid of all the fish examined (57 species) contained high iron concentrations ranging from 0.2% to 10.2% at the surface or middle layer, whereas that of an advanced suborder, Tetraodontoidei, of the Tetraodontiformes was very low in iron, at a level which could not be discriminated from the background value of the emission intensity. The distribution pattern of iron in the enameloid was classified into at least two types, namely, type A, in which a high iron concentration was observed mainly in the surface layer, and type B, in which iron was deposited throughout the entire layer, although there were differences in concentration. There were some differences in the concentration and distribution of iron in the enameloid for the families; for example, those of the Scaridae had a type A distribution, with about 0.2% iron only at the surface layer, whereas those of the Cichlidae, Centrarchidae, and Acanthuridae, which showed a type B distribution, contained iron ranging from 2.9% to 10.5% at the surface or middle layer of enameloid. Such differences seemed to be associated with the difference in timing of the commencement of the iron deposition into the developing enameloid, which is probably related to the phylogeny of fish. There was no evidence to support the idea that the iron concentration in

  5. Historical and current perspectives on fish assemblages of the Snake River, Idaho and Wyoming

    USGS Publications Warehouse

    Maret, T.R.; Mebane, C.A.

    2005-01-01

    The Snake River is the tenth longest river in the United States, extending 1,667 km from its origin in Yellowstone National Park in western Wyoming to its union with the Columbia River at Pasco, Washington. Historically, the main-stem Snake River upstream from the Hells Canyon Complex supported at least 26 native fish species, including anadromous stocks of Chinook salmon Oncorhynchus tshawytscha, steelhead O. mykiss, Pacific lamprey Lampetra tridentata, and white sturgeon Acipenser transmontanus. Of these anadromous species, only the white sturgeon remains in the Snake River between the Hells Canyon Complex and Shoshone Falls. Today, much of the Snake River has been transformed into a river with numerous impoundments and flow diversions, increased pollutant loads, and elevated water temperatures. Current (1993-2002) fish assemblage collections from 15 sites along the Snake River and Henrys Fork contained 35 fish species, including 16 alien species. Many of these alien species such as catfish (Ictaluridae), carp (Cyprinidae), and sunfish (Centrarchidae) are adapted for warmwater impounded habitats. Currently, the Snake River supports 19 native species. An index of biotic integrity (IBI), developed to evaluate large rivers in the Northwest, was used to evaluate recent (1993-2002) fish collections from the Snake River and Henrys Fork in southern Idaho and western Wyoming. Index of biotic integrity site scores and component metrics revealed a decline in biotic integrity from upstream to downstream in both the Snake River and Henrys Fork. Two distinct groups of sites were evident that correspond to a range of IBI scores-an upper Snake River and Henrys Fork group with relatively high biotic integrity (mean IBI scores of 46-84) and a lower Snake River group with low biotic integrity (mean IBI scores of 10-29). Sites located in the lower Snake River exhibited fish assemblages that reflect poor-quality habitat where coldwater and sensitive species are rare or absent, and

  6. Fish communities and related environmental conditions of the lower Boise River, southwestern Idaho, 1974-2004

    USGS Publications Warehouse

    MacCoy, Dorene E.

    2006-01-01

    Within the last century, the lower Boise River has been transformed from a meandering, braided, gravel-bed river that supported large runs of salmon to a channelized, regulated, urban river that provides flood control and irrigation water to more than 1,200 square miles of land. An understanding of the current status of the river's fish communities and related environmental conditions is important to support the ongoing management of the Boise River. Therefore, fish community data from the U.S. Geological Survey and the Idaho Department of Fish and Game collected since 1974 were analyzed to describe the status of fish communities in the lower Boise River. Each set of data was collected to address different study objectives, but is combined here to provide an overall distribution of fish in the lower Boise River over the last 30 years. Twenty-two species of fish in 7 families have been identified in the lower Boise River-3 salmonidae, trout and whitefish; 2 cottidae, sculpins; 3 catostomidae, suckers; 7 cyprinidae, minnows; 4 centrarchidae, sunfish; 2 ictaluridae, catfish; and 1 cobitidae, loach. Analysis of fish community data using an Index of Biotic Integrity (IBI) for Northwest rivers shows a decrease in the biotic integrity in a downstream direction, with the lowest IBI near the mouth of the Boise River. The number of tolerant and introduced fish were greater in the lower reaches of the river. Changes in land use, habitat, and water quality, as well as regulated streamflow have affected the lower Boise River fish community. IBI scores were negatively correlated with maximum instantaneous water temperature, specific conductance, and suspended sediment; as well as the basin land-use metrics, area of developed land, impervious surface area, and the number of major diversions upstream of a site. Fish communities in the upstream reaches were dominated by piscivorous fish, whereas the downstream reaches were dominated by tolerant, omnivorous fish. The percentage of

  7. Non-native species impacts on pond occupancy by an anuran

    USGS Publications Warehouse

    Adams, Michael J.; Pearl, Christopher A.; Galvan, Stephanie; McCreary, Brome

    2011-01-01

    Non-native fish and bullfrogs (Lithobates catesbeianus; Rana catesbeiana) are frequently cited as factors contributing to the decline of ranid frogs in the western United States (Bradford 2005). This hypothesis is supported by studies showing competition with or predation by these introduced species (Kupferberg 1997, Kiesecker and Blaustein 1998, Lawler et al. 1999, Knapp et al. 2001) and studies suggesting a deficit of native frogs at sites occupied by bullfrogs or game fish (Hammerson 1982, Schwalbe and Rosen 1988, Fisher and Shaffer 1996, Adams 1999). Conversely, other studies failed to find a negative association between native ranids and bullfrogs and point out that presence of non-native species correlates with habitat alterations that could also contribute to declines of native species (Hayes and Jennings 1986; Adams 1999, 2000; Pearl et al. 2005). A criticism of these studies is that they may not detect an effect of non-native species if the process of displacement is at an early stage. We are not aware of any studies that have monitored a set of native frog populations to determine if non-native species predict population losses. Our objective was to study site occupancy trends in relation to non-native species for northern red-legged frogs (Rana aurora) on federal lands in the southern Willamette Valley, Oregon. We conducted a 5-yr monitoring study to answer the following questions about the status and trends of the northern red-legged frog: 1) What is the rate of local extinction (how often is a site that is occupied in year t unoccupied in year t+1) and what factors predict variation in local extinction? and 2) What is the rate of colonization (how often is a site that is unoccupied in year t occupied in year t+1) and what factors predict variation in colonization? The factors we hypothesized for local extinction were: 1) bullfrog presence, 2) bullfrogs mediated by wetland vegetation, 3) non-native fish (Centrarchidae), 4) non-native fish mediated by

  8. Response of fish communities to cropland density and natural environmental setting in the Eastern Highland Rim Ecoregion of the lower Tennessee River basin, Alabama and Tennessee, 1999

    USGS Publications Warehouse

    Powell, Jeffrey R.

    2003-01-01

    Response of fish communities to cropland density and natural environmental setting were evaluated at 20 streams in the Eastern Highland Rim Ecoregion of the lower Tennessee River Basin during the spring of 1999. Sites were selected to represent a gradient of cropland densities in basins draining about 30 to 100 square miles. Fish communities were sampled by using a combination of seining and electrofishing techniques. A total of 10,550 individual fish, representing 63 species and 15 families, were collected during the study and included the families Cyprinidae (minnows), 18 species; Percidae (perch and darters), 12 species; and Centrarchidae (sunfish), 12 species. Assessments of environmental characteristics, including instream and terrestrial data and land-cover data, were conducted for each site. Instream measurements, such as depth, velocity, substrate type, and embeddedness, were recorded at 3 points across 11 equidistant transects at each site. Terrestrial measurements, such as bank angle, canopy angle, and canopy closure percentage, were made along the stream bank and midchannel areas. Water-quality data collected included pH, dissolved oxygen, specific conductivity, water temperature, nutrients, and fecal-indicator bacteria. Substrate embeddedness was the only variable correlated with both cropland density and fish communities (as characterized by ordination scores and several community level metrics). Multivariate and nonparametric correlation techniques were used to evaluate fish-community responses to physical and chemical factors associated with a cropland-density gradient, where the gradient was defined as the percentage of the basin in row crops. Principal component analysis and correspondence analysis suggest that the Eastern Highland Rim Ecoregion is composed of three subgroups of sites based on inherent physical and biological differences. Data for the subgroup containing the largest number of sites were then re-analyzed, revealing that several

  9. Interactions of bullfrog tadpole predators and an insecticide: Predation release and facilitation

    USGS Publications Warehouse

    Boone, M.D.; Semlitsch, R.D.

    2003-01-01

    The effect of a contaminant on a community may not be easily predicted, given that complex changes in food resources and predator-prey dynamics may result. The objectives of our study were to determine the interactive effects of the insecticide carbaryl and predators on body size, development, survival, and activity of tadpoles of the bullfrog (Rana catesbeiana). We conducted the study in cattle tank mesocosm ponds exposed to 0, 3.5, or 7.0 mg/l carbaryl, and no predators or two red-spotted newts (Notophthalmus viridescens), bluegill sunfish (Lepomis macrochirus), or crayfish (Orconectes sp.). Carbaryl negatively affected predator survival by eliminating crayfish from all ponds, and by eliminating bluegill sunfish from ponds exposed to the highest concentration of carbaryl; carbaryl exposure did not effect survival of red-spotted newts. Because crayfish were eliminated by carbaryl, bullfrogs were released from predation and survival was near that of predator controls at low concentrations of carbaryl exposure. High concentrations of carbaryl reduced tadpole survival regardless of whether predators survived carbaryl exposure or not. Presence of crayfish and newts reduced tadpole survival, while bluegill sunfish appeared to facilitate bullfrog tadpole survival. Presence of carbaryl stimulated bullfrog tadpole mass and development. Our study demonstrates that the presence of a contaminant stress can alter community regulation by releasing prey from predators that are vulnerable to contaminants in some exposure scenarios.

  10. Interactions of Amphibians, Fish, and Macroinvertebrates in a Southeastern Wetland

    NASA Astrophysics Data System (ADS)

    Schultheis, R. D.; Batzer, D. P.

    2005-05-01

    In fishless habitats, amphibians often compete with and are predators of macroinvertebrates. Unlike fish, the effects these interactions have on macroinvertebrate communities have been largely unexplored. We conducted an experiment in a semi-permanent oxbow wetland in the Piedmont region of Georgia to explore interactions between amphibians and macroinvertebrates. The predator community was dominated by Ambystoma opacum (Marbled Salamander) and Notophthalmus viridescens (Eastern Newt). Salamanders and newts were excluded from areas of wetland habitat using wire mesh cages (1.5M x 1.5M, 3mm mesh). The macroinvertebrate communities within the cages were then compared to the ambient habitat outside the cages. Fish, mostly Lepomis macrochirus (Bluegill) and Gambusia affinis (Mosquito Fish), colonized the wetland late in the first year of the study, and became common by year two. Also in year two, Rana catesbeiana (Bullfrog) became established. Thus, we were able to explore the variable effects on the macroinvertebrate community of a changing predator complex over a two year period.

  11. Determination of perfluorinated compounds in fish fillet homogenates: method validation and application to fillet homogenates from the Mississippi River.

    PubMed

    Malinsky, Michelle Duval; Jacoby, Cliffton B; Reagen, William K

    2011-01-10

    We report herein a simple protein precipitation extraction-liquid chromatography tandem mass spectrometry (LC/MS/MS) method, validation, and application for the analysis of perfluorinated carboxylic acids (C7-C12), perfluorinated sulfonic acids (C4, C6, and C8), and perfluorooctane sulfonamide (FOSA) in fish fillet tissue. The method combines a rapid homogenization and protein precipitation tissue extraction procedure using stable-isotope internal standard (IS) calibration. Method validation in bluegill (Lepomis macrochirus) fillet tissue evaluated the following: (1) method accuracy and precision in both extracted matrix-matched calibration and solvent (unextracted) calibration, (2) quantitation of mixed branched and linear isomers of perfluorooctanoate (PFOA) and perfluorooctanesulfonate (PFOS) with linear isomer calibration, (3) quantitation of low level (ppb) perfluorinated compounds (PFCs) in the presence of high level (ppm) PFOS, and (4) specificity from matrix interferences. Both calibration techniques produced method accuracy of at least 100±13% with a precision (%RSD) ≤18% for all target analytes. Method accuracy and precision results for fillet samples from nine different fish species taken from the Mississippi River in 2008 and 2009 are also presented. Copyright © 2010 Elsevier B.V. All rights reserved.

  12. A comparison of mercury burdens between St. Marks National Wildlife Refuge and St. Andrew Bay, Florida: Evaluation of fish body burdens and physiological responses in largemouth bass, spotted seatrout, striped mullet, and sunfish

    USGS Publications Warehouse

    Huge, D.H.; Rauschenberger, R.H.; Wieser, F.M.; Hemming, J.M.

    2011-01-01

    Musculature from the dorsal region of 130 largemouth bass (Micropterus salmoides), 140 sunfish (Lepomis sp.), 41 spotted seatrout (Cynoscion nebulosus) and 67 striped mullet (Mugil cephalus) were collected from five estuarine and five freshwater sites within the St. Marks National Wildlife Refuge and two estuarine and two freshwater sites from St. Andrew Bay, Florida, United States of America. Musculature was analyzed for total mercury content, sagittal otoliths were removed for age determination and physiological responses were measured. Largemouth bass and sunfish from the refuge had higher mercury concentrations in musculature than those from the bay. Male spotted seatrout, male striped mullet, male and female sunfish and female largemouth bass had mercury burdens positively correlated with length. The majority of all four species of fish from both study areas contained mercury levels below 1.5 part per million, the limit for safe consumption recommended the Florida Department of Health. In comparison, a significant percentage of largemouth bass and sunfish from several sampled sites, most notably Otter Lake and Lake Renfroe within St. Marks National Wildlife Refuge, had mercury levels consistent with the health department's guidelines of 'limited consumption' or 'no consumption guidelines.'

  13. Fish assemblage structure in an Oklahoma Ozark stream before and after rainbow trout introduction

    USGS Publications Warehouse

    Walsh, M.G.; Winkelman, D.L.

    2005-01-01

    Rainbow trout Oncorhynchus mykiss have been widely stocked throughout the United States as a popular sport fish. Our study was initiated to evaluate potential effects of rainbow trout introduction on native fishes to inform future decisions about trout stocking in northeastern Oklahoma streams. We sampled fish assemblages in pools, glides, and riffles in Brush Creek, Delaware County, Oklahoma, from February 2000 to September 2002, and experimentally stocked rainbow trout into the stream from November 2000 to March 2001 and November 2001 to March 2002. We used a combination of multivariate analyses to evaluate seasonal and habitat effects on native fish assemblages and to compare assemblage structure between prestocking, the first year of stocking, and the second year of stocking. Mesohabitat type significantly affected assemblage structure among years, whereas we did not detect an effect of season. We did not detect differences in assemblage structure among years in glide or riffle habitats. Native fish assemblage structure in pool habitats before rainbow trout introduction differed from assemblage structure in both the first and second year of stocking. Declines in seven species, including two native game fish (smallmouth bass Micropterus dolomieu and bluegill Lepomis machrochirus), contributed to assemblage dissimilarity in pool habitats between prestocking conditions and the second year of stocking. Our results indicate that stocking rainbow trout may cause local disruption in assemblage structure in pool habitats. ?? 2004 by the American Fisheries Society.

  14. Efficacy of candidate chemicals for preventing attachment of zebra mussels (Dreissena polymorpha)

    USGS Publications Warehouse

    Cope, W.G.; Bartsch, M.R.; Marking, L.L.

    1997-01-01

    Forty-seven chemicals having potential for preventing the attachment of zebra mussels Dreissena polymorpha were identified and tested. For each chemical, 15 zebra mussels (5-8-mm shell length) in each of two replicates and six treatments were exposed for 48 h followed by a 48-h postexposure period in untreated water. Eleven of the chemicals inhibited the reattachment of zebra mussels after the 48-h exposure; eight had EC50 values ranging from 0.4 to 5.4 mg /L, and three had EC50 values ranging from 19.4 to 29.0 mg/L. Based on an analysis of chemical cost, solubility in water, anticipated treatment concentrations, and potential hazards to humans or the environment, three of the most promising chemicals, all antioxidants (butylated hydroxyanisole [BHA], tert-butylhydroquinone, and tannic acid) were tested on nontarget fish (bluegill, Lepomis macrochirus; channel catfish, Ictalurus punctatus; and rainbow trout, Oncorhynchus mykiss). These chemicals were not selectively toxic to zebra mussels; only the tests with bluegill and BHA and with channel catfish and tannic acid had 48-h LC50 values greater than the concentrations effective for preventing the reattachment of zebra mussels. Although the attachment of zebra mussels can be prevented with selected antioxidants, an alternative formulation should be investigated to minimize effects on nontarget organisms, such as fish.

  15. Parasites of two native fishes in adjacent Adirondack lakes.

    PubMed

    Bauer, Eric F; Whipps, Christopher M

    2013-08-01

    This survey of parasites in 2 adjacent lakes is the first of its kind in the Adirondack Park of New York State. Wolf Lake is designated as a heritage lake whereas nearby Deer Lake is limnologically similar but has at least 5 introduced fish species. Both lakes have 2 native species, i.e., white sucker (Catostomus commersoni) and redbreast sunfish (Lepomis auritus), which were the focus of this study. Parasite communities of both hosts were surveyed and compared between each lake and were statistically evaluated for differences in species similarity, prevalence, mean intensity, and mean abundance. Between lakes, white suckers had significant differences in the prevalence of 4 parasite species (Myxobolus sp. 2, Myxobolus bibulatus, Octospinifer macilentis, and Pomphorhynchus bulbocoli) and mean abundances of 4 parasites (neascus larvae, Octospinifer macilentis, Pomphorhynchus bulbocoli, and Glaridacris confusus). Redbreast sunfish had significant differences in the prevalence of 3 species (Myxobolus uvuliferis, a coccidian species, and Spinitectus carolini) and differences in parasite mean abundance of 5 species (neascus larvae, Clinostomum marginatum , Leptorhynchoides thecatus, Spinitectus carolini, and Eustrongylides sp.). Differences in component communities between lakes were found and, although the exact causes cannot be determined by this study, we speculate on several possible explanations.

  16. Dynamic adjustment of parental care in response to perceived paternity.

    PubMed

    Neff, B D; Gross, M R

    2001-08-07

    Theories of parental care evolution predict that genetic relatedness will be an important variable in the amount of care a parent provides. However, current inferences of relatedness-based parental investment from studies in humans and birds remain challenged. No study has yet demonstrated parental care adjustment in a manner uncomplicated by life-history correlates or experimental design. We now present a unique test that controls for individual life histories and demonstrates paternity-related dynamic adjustments in parental care. Brood-rearing male bluegill sunfish (Lepomis macrochirus) that are cuckolded to a varying degree will either increase or decrease their parental investment in response to changing information on paternity during brood development. Specifically, as parental males detect paternity lost to cuckolders and, hence, a reduction in the value of their brood, they adaptively lower their level of parental care. Conversely, if they detect that their paternity is higher than previously assessed, they adaptively raise their level of parental care. This dynamic adjustment during brood rearing indicates the importance of genetic relatedness in parental investment decisions and provides needed empirical support for theoretical predictions.

  17. Decisions about parental care in response to perceived paternity.

    PubMed

    Neff, Bryan D

    2003-04-17

    Evolutionary ecologists are attempting to explain how parents make behavioural decisions about how much care to provide to their young. Theory predicts that when genetic relatedness to young is decreased by cuckoldry, for example, parents should reduce their care in favour of alternative broods that provide greater reproductive success. Experimental manipulation of perceived paternity has been used to test the theory, but such studies have generated mixed results. Some manipulations can fail to alter a parent's perceived paternity, whereas others may directly affect parental behaviour when, for instance, the manipulation involves capturing the parent. No study has demonstrated parental care adjustment in a manner uncomplicated by experimental design or life history correlates. Here I test the theory using the fact that nest-tending parental male bluegill sunfish (Lepomis macrochirus) can assess their paternity using both the visual presence of parasitic cuckolder males during spawning, and olfactory cues released by newly hatched eggs. By manipulating both types of cues I show that parental males dynamically adjust their parental care, favouring broods that are apparently most closely related. These results confirm the importance of genetic relatedness in parental care decision-making.

  18. Observations of bluegills fed selenium-contaminated Hexagenia nymphs collected from Belews Lake, North Carolina

    SciTech Connect

    Finley, K.A.

    1985-12-01

    Belews Lake, a 1563-ha reservoir in the Piedmont region of North Carolina, was impounded in the early 1970's to provide cooling water for a 2240 Mw coal-fired electric generating station. Hatchery-raised bluegill (Lepomis macrochirus) fingerlings stocked in several net-isolated Belews Lake coves during 1979 experienced a rapid uptake of coal ash-associated trace elements, principally selenium, in skeletal muscle and visceral tissues. Generally, higher selenium concentrations and evidences of acute toxicity, including exophthalmos and extreme abdominal distention, were observed only among fish having unrestricted access to sediments and benthos. Bluegills which were caged above the sediments in the same coves, and presumably had less opportunity to feed on benthic organisms, concentrated selenium to a lesser degree. Those observations, in addition to information provided by inspection of fish stomach contents and tissue elemental analyses of fish and benthic macroinvertebrates, strongly implicate predation on contaminated benthos as an important pathway for selenium uptake and resulting toxicity to fish in Belews Lakes. However, direct experimental evidence relating levels of dietary selenium to toxic effects among warm water fish species is sparse. The present study was intended to document the occurrence of selenium toxicity in bluegills fed to satiation a diet consisting of a common benthic food organism found in Belews Lake.

  19. Persistence of viral RNA in fish infected with VHSV-IVb at 15°C and then moved to warmer temperatures after the onset of disease.

    PubMed

    Goodwin, A E; Merry, G E; Noyes, A D

    2012-07-01

    Smallmouth bass, Micropterus dolomieu Lacepède, bluegill, Lepomis macrochirus Rafinesque (coppernose strain), koi carp, Cyprinus carpio L., and channel catfish Ictalurus punctatus (Rafinesque), were infected by intraperitoneal injection with viral haemorrhagic septicaemia virus genotype IVb (VHSV-IVb) at 15 °C. When clinical signs of disease developed, one-third of the fish was moved to 20°C and one-third to 25°C. Mortality in challenged fish at all three temperatures ranged from 25 to 45% in smallmouth bass and from 70 to 90% in bluegill. No koi carp or channel catfish died during the study. Viral copy numbers detected by quantitative real-time reverse transcriptase PCR (qrt-RTPCR) in fish dying at 20 and 25°C decreased over time. In survivors of the challenge, viral copy numbers were higher in the more susceptible species (smallmouth bass and bluegill) than in the more VHSV-IVb disease-resistant species (koi carp and channel catfish). In fish surviving 28days post-infection, prevalence of infection was 66-100% depending on species and temperature, and VHSV-IVb was detected at 10(3) -10(5) copies μg(-1) host RNA. Our results show that qrt-RTPCR is a useful tool to investigate fish kills even 28days after temperatures are elevated above those known to be permissive for VHSV replication.

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

    PubMed

    Ito, Takafumi; Olesen, Niels Jørgen

    2013-11-25

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

  1. Germ cell-somatic cell relationships: a comparative study of intercellular junctions during spermatogenesis in selected non-mammalian vertebrates.

    PubMed

    Sprando, R L; Russell, L D

    1987-09-01

    Specialized germ cell-somatic cell relationships were surveyed in the testis of species representative of four classes of non-mammalian vertebrates. Desmosome-like junctions were present in all classes studied. In the teleost fish studied (bluegill; Lepomis macrochirus), small, infrequent desmosomes, seen between the spherical cyst cells and spermatocytes, were characterized by poorly represented subsurface densities. In the bullfrog (Rana catesbeiana), similar desmosome-like junctions were found between cyst cell processes and spermatocytes. Reptilian (turtle; Pseudameys scripta) desmosome-like junctions between Sertoli cells and germ cells were heterogeneous and more numerous than those junctions found in fish and amphibians. In general, the reptilian desmosome-like junctions were extensive structures displaying 10 nm filaments associated with the Sertoli cell component of the junctions. Regions within the desmosome where the two plasma membranes converged suggested that gap junctions were a component of the desmosome-like junctions. "Desmosome-gap" junctions persisted in turtle spermatids for sometime after nuclear elongation had commenced. In birds (chicken; Gallus domesticus), "desmosome-gap" junctions, similar to those seen in turtles were described between both spermatocytes and Sertoli cells, and spermatids and Sertoli cells. These junctions were frequently lined by saccules of endoplasmic reticulum. The presence of gap junctions suggest the evolution of mechanisms for somatic cell-germ cell communication although more species should be examined to confirm this hypothesis.

  2. Competitive Interactions between Invasive Nile Tilapia and Native Fish: The Potential for Altered Trophic Exchange and Modification of Food Webs

    PubMed Central

    Martin, Charles W.; Valentine, Marla M.; Valentine, John F.

    2010-01-01

    Recent studies have highlighted both the positive and negative impacts of species invasions. Most of these studies have been conducted on either immobile invasive plants or sessile fauna found at the base of food webs. Fewer studies have examined the impacts of vagile invasive consumers on native competitors. This is an issue of some importance given the controlling influence that consumers have on lower order plants and animals. Here, we present results of laboratory experiments designed to assess the impacts of unintended aquaculture releases of the Nile tilapia (Oreochromis niloticus), in estuaries of the Gulf of Mexico, on the functionally similar redspotted sunfish (Lepomis miniatus). Laboratory choice tests showed that tilapia prefer the same structured habitat that native sunfish prefer. In subsequent interspecific competition experiments, agonistic tilapia displaced sunfish from their preferred structured habitats. When a piscivore (largemouth bass) was present in the tank with both species, the survival of sunfish decreased. Based on these findings, if left unchecked, we predict that the proliferation of tilapia (and perhaps other aggressive aquaculture fishes) will have important detrimental effects on the structure of native food webs in shallow, structured coastal habitats. While it is likely that the impacts of higher trophic level invasive competitors will vary among species, these results show that consequences of unintended releases of invasive higher order consumers can be important. PMID:21200433

  3. Determination of total mercury in fillets of sport fishes collected from Folsom Reservoir, California, 2006

    USGS Publications Warehouse

    May, Thomas W.; Brumbaugh, William G.

    2007-01-01

    This report presents the results of a study by the U.S. Geological Survey, done in cooperation with the U.S. Bureau of Reclamation, to determine mercury concentrations in selected sport fishes from Folsom Reservoir in California. Fillets were collected from each fish sample, and after homogenization and lyophilization of fish fillets, mercury concentrations were determined with a direct mercury analyzer utilizing the process of thermal combustion-gold amalgamation atomic absorption spectroscopy. Mercury concentrations in fillets ranged from 0.031 to 0.20 micrograms per gram wet weight in rainbow trout (Oncorhynchus mykiss) samples and 0.071 to 0.16 micrograms per gram wet weight in bluegill (Lepomis macrochirus) samples. Mercury concentration was 0.98 microgram per gram wet weight in a single spotted bass (Micropterus punctulatus) sample, which was the only one in the sample set which exceeded the U.S. Environmental Protection Agency's fish consumption advisory of 0.30 microgram per gram wet weight.

  4. Geochemical properties of coal wastes and the toxicological effects on aquatic life. Environmental geology notes

    SciTech Connect

    Roy, W.R.; Krapac, I.G.; Griffin, R.A.; Dickerson, D.R.; Schuller, R.M.

    1984-01-01

    Leachates from solid wastes generated by coal mining, cleaning, and gasification are potentially harmful to the environment. The toxicological effects of leachates on aquatic organisms have not been adequately assessed. In this investigation, samples of seven coal-related wastes were charcterized chemically and mineralogically. Laboratory extracts of each sample, obtained by a variety of extraction methods, were used in both acute and chronic bioassay. A coal-slurry sample (coarse fraction) and two samples of coal-cleaning refuse were chemically and mineralogically similar; they generated acidic water-waste systems, both in the laboratory and in the field. Two mine-spoil samples, essentially shale, tended to generate water-waste systems that were neutral in pH; consequently, they released lower quantities of potential pollutants than the acidic wastes. Each extract was tested for acute toxicity with four species of fresh-water aquatic organisms; the green sunfish (Lepomis cyanellus), the fathead minnow, (Pimephales promelas), a crustacean (Daphia magna), and a snail (Physa anatina). The extracts of the two mine spoil samples and of the gasification residue were not toxic to any of the organisms; whereas the extracts from the acidic refuse and slurry samples were acutely toxic to all the organisms.

  5. The effects of steady swimming on fish escape performance.

    PubMed

    Anwar, Sanam B; Cathcart, Kelsey; Darakananda, Karin; Gaing, Ashley N; Shin, Seo Yim; Vronay, Xena; Wright, Dania N; Ellerby, David J

    2016-06-01

    Escape maneuvers are essential to the survival and fitness of many animals. Escapes are frequently initiated when an animal is already in motion. This may introduce constraints that alter the escape performance. In fish, escape maneuvers and steady, body caudal fin (BCF) swimming are driven by distinct patterns of curvature of the body axis. Pre-existing muscle activity may therefore delay or diminish a response. To quantify the performance consequences of escaping in flow, escape behavior was examined in bluegill sunfish (Lepomis macrochirus) in both still-water and during steady swimming. Escapes executed during swimming were kinematically less variable than those made in still-water. Swimming escapes also had increased response latencies and lower peak velocities and accelerations than those made in still-water. Performance was also lower for escapes made up rather than down-stream, and a preference for down-stream escapes may be associated with maximizing performance. The constraints imposed by pre-existing motion and flow, therefore, have the potential to shape predator-prey interactions under field conditions by shifting the optimal strategies for both predators and prey.

  6. Localized effects of coal mine drainage on fish assemblages in a Cumberland Plateau stream in Tennessee

    SciTech Connect

    Schorr, M.S.; Backer, J.C.

    2006-03-15

    The upper watershed of North Chickamauga Creek (NCC), a fourth-order tributary to the Tennessee River, Tennessee, has been impacted by decades of acid mine drainage (AMD) from abandoned coal mines. We assessed fish assemblages, pH, conductivity, and sediment coverage at 12 study reaches (six AMD sites and six reference sites) in the Cumberland Plateau region of the NCC system, May-September 1998. Stream pH increased (3.6 to 6.0) and conductivity decreased (296 to 49 {mu}S/cm) downstream of the AMD-impacted area; however, no discernable gradient was observed in sediment cover. Elevated conductivity at AMD-impacted sites reflected increased concentrations of dissolved metals and other inorganic ions. Reference sites exhibited higher pH (6.0-6.4) and lower conductivity (13-28 {mu}S/cm). Acidified reaches were characterized by low fish species richness and abundance; no fish were observed at sites where the mean pH was {lt} 5. Centrarchids (mostly bluegill (Lepomis macrochirus) and green sunfish (L. cyanellus)) comprised {gt} 90 % of the catch at AMD sites, whereas cypriniids (creek chub (Semotilus atromaculatus) and blacknose dace (Rhinichthys atratulus)) accounted for {gt} 90 % of the catch at reference sites. Findings from this study document the negative effects of acid drainage from coal mines on fish assemblages in a Cumberland Plateau stream.

  7. Reproductive biology of four freshwater mussels (Bivalvia: Unionidae) endemic to eastern Gulf Coastal Plain drainages of Alabama, Florida, and Georgia

    USGS Publications Warehouse

    O'Brien, C. A.; Williams, J.D.

    2002-01-01

    The reproductive biology and glochidial shell morphology of three federally endangered freshwater mussels, the fat threeridge, Amblema neislerii; Gulf moccasinshell, Medionidus penicillatus; and oval pigtoe, Pleurobema pyriforme; and one federally threatened mussel, the purple bankclimber, Elliptoideus sloatianus, were studied from May 1995 to June 1997 in the Apalachicola, Flint, and Ochlockonee river drainages of Florida and Georgia. Gravid A. neislerii were found in early June. Laboratory experiments indicated that five fish species served as hosts: weed shiner, Notropis texanus; bluegill, Lepomis macrochirus; redear sunfish, L. microlophus; largemouth bass, Micropterus salmoides; and blackbanded darter, Percina nigrofasciata. Elliptoideus sloatianus were found gravid from late February through mid-April. None of the 14 fish species exposed to E. sloatianus glochidia resulted in the identification of a primary host fish. Medionidus penicillatus were found gravid during September, November, March, and April. The brown darter, Etheostoma edwini, and blackbanded darter, Percina nigrofasciata, were identified as primary host fishes for M. penicillatus. Pleurobema pyriforme were found gravid from March through July. Only the sailfin shiner, Pleronotropis hypsehpterus, was identified as a primary host fish for P. pyriforme. Glochidial shell morphology of A. neislerii, M. penicillatus, and P. pyriforme were similar to other species in their respective genera. The glochidia of the monotypic species E. sloatianus were morphologically most similar to Epioblasma brevidens and E. capsaeformis.

  8. Development and characterization of a largemouth bass cell line.

    PubMed

    Getchell, Rodman G; Groocock, Geoffrey H; Cornwell, Emily R; Schumacher, Vanessa L; Glasner, Lindsay I; Baker, Barry J; Frattini, Stephen A; Wooster, Gregory A; Bowser, Paul R

    2014-09-01

    Abstract The development and characterization of a new cell line, derived from the ovary of Largemouth Bass Micropterus salmoides, is described. Gonad tissue was collected from Largemouth Bass that were electrofished from Oneida Lake, New York. The tissue was processed and grown in culture flasks at approximately 22°C for more than 118 passages during an 8-year period from 2004 to 2011. The identity of these cells as Largemouth Bass origin was confirmed by sequencing a portion of the cytochrome b gene. Growth rate at three different temperatures was documented. The cell line was susceptible to Largemouth Bass virus (LMBV) and its replication was compared with that of Bluegill Lepomis macrochirus fry (BF-2), one of the cell lines recommended for LMBV isolation by the American Fisheries Society Fish Health Section Blue Book. Quantitative PCR results from the replication trial showed the BF-2 cell line produced approximately 10-fold more LMBV copies per cell than the new Largemouth Bass cell line after 6 d, while the titration assay showed similar quantities in each cell line after 1 week. Received February 18, 2014; accepted April 16, 2014.

  9. Reproductive characteristics of a population of the washboard mussel Megalonaias nervosa (Rafinesque 1820) in the upper Mississippi River

    USGS Publications Warehouse

    Woody, C.A.; Holland-Bartels, L.

    1993-01-01

    The authors examined monthly and age-specific gametogenic development of the washboard mussel, Megalonaias nervosa, from April 1986 to March 1987 in navigation Pool 10 of the upper Mississippi River. The authors found M. nervosa to be a late tachytictic breeder. Female marsupia contained eggs or glochidia primarily from August (17 degree C) through October (9 degree C). Males were mature from July through October. Most females released their glochidia in October. Only one female was gravid in Nov (3 degree C). Most mussels were sexually mature at 8 years of age and then had an estimated average size of 68 mm (shell height). Only 8% of individuals less than or equal to 4 years of age showed any degree of reproductive development, while > 90% of age 5 and older individuals had recognizable reproductive material present. In host specificity studies, three fish species were verified as hosts for the glochidial stage. Green sunfish (Lepomis cyanellus), black bullhead (Ictalurus melas), and channel catfish (Ictalurus punctatus) produced juveniles after 26-28 days at 17 degree C. White suckers (Catastomus commersoni) and yellow perch (Perca flavescens) retained glochidia from 23 up to 26 days, but no juveniles were produced. Glochidia remained attached to common carp (Cyprinus carpio) and fathead minnows (Pimephales promelas) less than or equal to 3 days. Channel catfish were retested at 12 degree C and produced juveniles after 56 days.

  10. Fish abundance and population stability in a reservoir tailwater and an unregulated headwater stream

    USGS Publications Warehouse

    Jacobs, K.E.; Swink, W.D.

    1983-01-01

    Fish abundance and population stability were compared in the tailwater and in an unregulated tributary of Barren River Lake, a flood control reservoir in south central Kentucky. Fish abundance was greater in the tailwater near the dam and was dominated by three species common in the reservoir: gizzard shad (Dorosoma cepedianum), bluegills (Lepomis macrochirus), and white crappies (Pomoxis annularis). Three riverine suckers were less abundant in the tailwater than in the unregulated stream: northern hog suckers (Hypentelium nigricans), black redhorse (Moxostoma duquesnei), and golden redhorse (Moxostoma erythrurum). The fish populations in the tailwater, particularly common carp (Cyprinus carpio), northern hog suckers, black redhorse, and golden redhorse, were less stable than those in the unregulated stream. Population stability is defined as the extent to which fish remain in a stream section. This study suggests that the occurrence of reservoir species in the tailwater was the result of fish passage from the reservoir during high discharges in fall and winter. Reservoir operations (altered flow, low summer water temperature, and poor summer water quality) probably were responsible for the unstable populations of common carp and riverine suckers in the tailwater.

  11. Comparison of treatments to inactivate viral hemorrhagic septicemia virus (VHSV-IVb) in frozen baitfish.

    PubMed

    Phelps, Nicholas B D; Goodwin, Andrew E; Marecaux, Emily; Goyal, Sagar M

    2013-02-28

    Current US state and federal fish health regulations target the spread of viral hemorrhagic septicemia virus-IVb (VHSV-IVb) through movement restrictions of live fish; however, they largely ignore the potential for the virus to be spread through commercial distribution and use of frozen baitfish from VHSV-IVb-positive regions. Some state laws do require treatment of frozen baitfish to inactivate VHSV, and additional methods have been proposed, but few scientific studies have examined the efficacy of these treatments. In this study, bluegills Lepomis macrochirus were challenged with VHSV-IVb and frozen to represent standard industry methods, disinfected by various treatments, and tested for infectious VHSV-IVb using virus isolation. The virus was isolated from 70% of fish subjected to 3 freeze/thaw cycles. All other treatment methods were effective in inactivating the virus, including treatment with isopropyl alcohol, mineral oil, salt and borax, and dehydration. Dehydration followed by rehydration is rapid and effective, and therefore, seems to be the best option for inactivating VHSV-IVb present in frozen baitfish while maintaining their usefulness as bait.

  12. Differences between main-channel and off-channel food webs in the upper Mississippi River revealed by fatty acid profiles of consumers

    USGS Publications Warehouse

    Larson, James H.; Bartsch, Michelle; Gutreuter, Steve; Knights, Brent C.; Bartsch, Lynn; Richardson, William B.; Vallazza, Jonathan M.; Arts, Michael T.

    2015-01-01

    Large river systems are often thought to contain a mosaic of patches with different habitat characteristics driven by differences in flow and mixing environments. Off-channel habitats (e.g., backwater areas, secondary channels) can become semi-isolated from main-channel water inputs, leading to the development of distinct biogeochemical environments. Observations of adult bluegill (Lepomis macrochirus) in the main channel of the Mississippi River led to speculation that the main channel offered superior food resources relative to off-channel areas. One important aspect of food quality is the quantity and composition of polyunsaturated fatty acids (PUFA). We sampled consumers from main-channel and backwater habitats to determine whether they differed in PUFA content. Main-channel individuals for relatively immobile species (young-of-year bluegill, zebra mussels [Dreissena polymorpha], and plain pocketbook mussels [Lampsilis cardium]) had significantly greater PUFA content than off-channel individuals. No difference in PUFA was observed for the more mobile gizzard shad (Dorsoma cepedianum), which may move between main-channel and off-channel habitats even at early life-history stages. As off-channel habitats become isolated from main-channel waters, flow and water column nitrogen decrease, potentially improving conditions for nitrogen-fixing cyanobacteria and vascular plants that, in turn, have low PUFA content. We conclude that main-channel food webs of the upper Mississippi River provide higher quality food resources for some riverine consumers as compared to food webs in off-channel habitats.

  13. Isolation and molecular characterization of a novel picornavirus from baitfish in the USA.

    PubMed

    Phelps, Nicholas B D; Mor, Sunil K; Armien, Anibal G; Batts, William; Goodwin, Andrew E; Hopper, Lacey; McCann, Rebekah; Ng, Terry Fei Fan; Puzach, Corey; Waltzek, Thomas B; Delwart, Eric; Winton, James; Goyal, Sagar M

    2014-01-01

    During both regulatory and routine surveillance sampling of baitfish from the states of Illinois, Minnesota, Montana, and Wisconsin, USA, isolates (n = 20) of a previously unknown picornavirus were obtained from kidney/spleen or entire viscera of fathead minnows (Pimephales promelas) and brassy minnows (Hybognathus hankinsoni). Following the appearance of a diffuse cytopathic effect, examination of cell culture supernatant by negative contrast electron microscopy revealed the presence of small, round virus particles (∼ 30-32 nm), with picornavirus-like morphology. Amplification and sequence analysis of viral RNA identified the agent as a novel member of the Picornaviridae family, tentatively named fathead minnow picornavirus (FHMPV). The full FHMPV genome consisted of 7834 nucleotides. Phylogenetic analysis based on 491 amino acid residues of the 3D gene showed 98.6% to 100% identity among the 20 isolates of FHMPV compared in this study while only 49.5% identity with its nearest neighbor, the bluegill picornavirus (BGPV) isolated from bluegill (Lepomis macrochirus). Based on complete polyprotein analysis, the FHMPV shared 58% (P1), 33% (P2) and 43% (P3) amino acid identities with BGPV and shared less than 40% amino acid identity with all other picornaviruses. Hence, we propose the creation of a new genus (Piscevirus) within the Picornaviridae family. The impact of FHMPV on the health of fish populations is unknown at present.

  14. Concentration trends for lead and calcium-normalized lead in fish fillets from the Big River, a mining-contaminated stream in southeastern Missouri USA

    USGS Publications Warehouse

    Schmitt, Christopher J.; McKee, Michael J.

    2016-01-01

    Lead (Pb) and calcium (Ca) concentrations were measured in fillet samples of longear sunfish (Lepomis megalotis) and redhorse suckers (Moxostoma spp.) collected in 2005–2012 from the Big River, which drains a historical mining area in southeastern Missouri and where a consumption advisory is in effect due to elevated Pb concentrations in fish. Lead tends to accumulated in Ca-rich tissues such as bone and scale. Concentrations of Pb in fish muscle are typically low, but can become elevated in fillets from Pb-contaminated sites depending in part on how much bone, scale, and skin is included in the sample. We used analysis-of-covariance to normalize Pb concentration to the geometric mean Ca concentration (415 ug/g wet weight, ww), which reduced variation between taxa, sites, and years, as was the number of samples that exceeded Missouri consumption advisory threshold (300 ng/g ww). Concentrations of Pb in 2005–2012 were lower than in the past, especially after Ca-normalization, but the consumption advisory is still warranted because concentrations were >300 ng/g ww in samples of both taxa from contaminated sites. For monitoring purposes, a simple linear regression model is proposed for estimating Ca-normalized Pb concentrations in fillets from Pb:Ca molar ratios as a way of reducing the effects of differing preparation methods on fillet Pb variation.

  15. Aminolevulinic acid-dehydratase activity in green sunfish: An indicator of lead bioavailability in suspended sediments

    SciTech Connect

    Caldwell, C.; Steingraeber, M.

    1995-12-31

    Green sunfish (Lepomis cyanellus, 6-32 g) were exposed for 28 days to suspended sediments and sediments not in suspension (bedded). Blood was collected for aminolevulinic acid-dehydratase activity (ALA-D), hemoglobin and blood lead concentrations, and whole body lead concentrations. Results of the metal analysis of filtered and unfiltered water from both suspended and bedded sediment tests revealed that the majority of the metal was associated with particulate matter in suspension. Fish subjected to suspended sediments (0.2, 1.6, and 21.9 ug/g lead, dry weight) had significantly reduced ALA-D and hemoglobin concentrations than fish in bedded sediments. However, there was no significant correlation between lead concentrations in suspended sediments and ALA-D activity. In addition, there were no significant correlations between ALA-D activity and hemoglobin concentrations. Whole body analysis and blood lead concentrations were not good indicators of lead exposure in sediment tests having relatively low concentrations of lead.

  16. Test system for exposing fish to resuspended, contaminated sediment

    USGS Publications Warehouse

    Cope, W.G.; Wiener, J.G.; Steingraeber, M.T.

    1996-01-01

    We describe a new test system for exposing fish to resuspended sediments and associated contaminants. Test sediments were resuspended by revolving test chambers on rotating shafts driven by an electric motor. The timing, speed, and duration of test-chamber revolution were controlled by a rheostat and electronic timer. Each chamber held 45 litres of water and accommodated about 49 g of test fish. The system described had three water baths, each holding six test chambers. We illustrate the performance of this system with results from a 28-day test in which juvenile bluegills Lepomis macrochirus were exposed to resuspended, riverine sediments differing in texture and cadmium content. The test had one sediment-free control and five sediment treatments, with three replicates (chambers) per treatment and 25 fish per replicate. Two-thirds (30 litres) of the test water and sediment in each chamber was renewed weekly. The mean concentration of total suspended solids (TSS) did not vary among treatments; the grand-mean TSS in the five sediment treatments was 975 mg litre−1, similar to the target TSS of 1000 mg litre−1. At the end of the test, an average of 50% of the introduced cadmium was associated with the suspended sediment compartment, whereas the filtered (0.45 μm) water contained 0.4% and bluegills 1.8% of the cadmium.

  17. Thidiazuron uptake, distribution and metabolism in bluegills and channel catfish.

    PubMed

    Knowles, C O; Benezet, H J; Mayer, F L

    1980-01-01

    Bluegills (Lepomis macrochirus) exposed to 0.1 ppm of thidiazuron-14C cotton defoliant for 28 days under continuous flow conditions accumulated relatively low levels of radiocarbon. The maximum detected was 5.4 ppm in fillet tissue after 1 day. During a 14 day depuration period, radioactivity declined to 1.0 ppm or less. Fractionation of offal and fillet tissues from bluegills collected at 28 days indicated that most of the radioactive material was water soluble, although appreciable amounts of organosoluble radioactive material also were present. When bluegills were injected intraperitoneally with thidiazuron-14C, metabolism and elimination were relatively rapid. Organosoluble radioactive material isolated from fish tissue included thidiazuron, its 2-hydroxyphenyl derivative, phenylurea, and several unknowns. Channel catfish (Ictalurus punctatus) exposed under static conditions to a system containing 0.15 ppm of thidiazuron-14C incorporated into soil also accumulated only low concentrations of radiocarbon. The maximum detected was 2.5 ppb in offal tissue at 7 days. In fillet tissue, radioactivity did not exceed 0.5 ppb. There was no evidence from these studies to indicate that thidiazuron would pose a hazard to the aquatic ecosystem.

  18. Biological structure and dynamics of littoral fish assemblages in the eastern Finger Lakes

    USGS Publications Warehouse

    McKenna, James E.

    2001-01-01

    Fish assemblages from three of the New York Finger Lakes were examined for structure within and between lakes and over time. Species-area relationships indicated that local fish assemblages are the result of recent, lake-specific events that altered the regional species pool. Fish assemblages varied among seasons and those occupying eutrophic waters had different characteristics from those in oligotrophic waters. Bluntnose minnows (Pimephales notatus) were a persistent and important component of most assemblages, but abundance of bluegill (Lepomis macrochirus) was the most distinguishing feature. Species associations indicated that interactions among the fishes had little influence on assemblage structure. Correlations between community structure and abiotic factors were identified. Ten abiotic variables were strongly associated with the species assemblages, but could not fully explain differences between assemblages. Results indicate that the abundance and diversity of water column feeders was related to productivity of lake habitat. In general, fish populations were smaller in oligotrophic waters and water column feeders were poorly represented in those assemblages. Productivity at various trophic levels was implicated as a major factor determining lake fish assemblage structure.

  19. Seasonal and diel habitat selection by bluegills in a shallow natural lake

    USGS Publications Warehouse

    Paukert, C.P.; Willis, D.W.

    2002-01-01

    Habitat use by bluegill Lepomis macrochirus may be dictated by the avoidance of predators and the availability of prey. Previous work suggests that bluegills large enough to avoid predators will select habitats based on foraging profitability. However, these studies focused on smaller fish (200 mm total length [TL]) bluegills in a shallow (mean depth = 1.2 m), 332-ha, natural lake (Pelican Lake, Nebraska) with both emergent and submergent vegetation distributed throughout. A total of 78 bluegills (200-273 mm TL) were implanted with radio transmitters and relocated daily for 6 d per month (April-September); up to 20 of the tagged fish were relocated every 2 h for a 24-h period once each month. Regardless of diel period, bluegills used open-water, emergent vegetation, submergent vegetation, and mixed emergent - submergent vegetation habitat types in similar proportions. During April, June, and July, male bluegills positively selected emergent vegetation, whereas female bluegills showed no vegetation selection preference during any month. Throughout the study period, bluegills never avoided open-water habitats, suggesting that larger individuals may continue to use open-water habitats in proportion to their availability. In addition, emergent vegetation appeared to be important, particularly for male bluegills. Although the mechanism for the positive selection of emergent vegetation by males was unclear, the protection or enhancement of such habitats may facilitate the preservation of quality bluegill populations in shallow lakes.

  20. Strong effects of predation by fishes on an invasive macroinvertebrate in a large floodplain river

    USGS Publications Warehouse

    Bartsch, M.R.; Bartsch, L.A.; Gutreuter, S.

    2005-01-01

    We assessed the effects of fish predation on zebra mussels (Dreissena polymorpha) in Navigation Pool 8 of the Upper Mississippi River from 13 May to 5 October, 1998. Concrete-block samplers were deployed at 18 randomly chosen sites in the main-channel border, with 6 sites in the upper, middle, and lower segments of the pool. Two blocks, 1 of which was enclosed in a cage to exclude large predatory fishes, were deployed at each site. After 145 d, blocks were retrieved from 12 of the 18 sites, and zebra mussels were found on all blocks. Densities of zebra mussels were higher on caged blocks than uncaged blocks, and the magnitudes of the differences varied spatially. Mean mussel densities on uncaged blocks were reduced by 66%, 86%, and 20% compared to caged blocks in the upper, middle, and lower pool segments, respectively, over the 145-d interval. Mean daily instantaneous zebra mussel mortality rates from large predators ranged from 0.0016 to 0.0138. Similarly, biomass of zebra mussels was higher on caged than uncaged blocks. Mean mussel biomass on uncaged blocks was reduced by 64% pool-wide, relative to biomass on caged blocks. Zebra mussels were consumed by at least 6 fish taxa including redhorse stickers (Moxostoma spp.), common carp (Cyprinus carpio), bluegill (Lepomis macrochirus), quillback carpsucker (Carpiodes cyprinus), flathead catfish (Pylodictis olivaris), and freshwater drum (Aplodinotus grunniens). Fish predation had an important moderating effect on zebra mussel demography in Pool 8.

  1. Identifying non-point sources of endocrine active compounds and their biological impacts in freshwater lakes

    USGS Publications Warehouse

    Baker, Beth H.; Martinovic-Weigelt, Dalma; Ferrey, Mark L.; Barber, Larry B.; Writer, Jeffrey H.; Rosenberry, Donald O.; Kiesling, Richard L.; Lundy, James R.; Schoenfuss, Heiko L.

    2014-01-01

    Contaminants of emerging concern, particularly endocrine active compounds (EACs), have been identified as a threat to aquatic wildlife. However, little is known about the impact of EACs on lakes through groundwater from onsite wastewater treatment systems (OWTS). This study aims to identify specific contributions of OWTS to Sullivan Lake, Minnesota, USA. Lake hydrology, water chemistry, caged bluegill sunfish (Lepomis macrochirus), and larval fathead minnow (Pimephales promelas) exposures were used to assess whether EACs entered the lake through OWTS inflow and the resultant biological impact on fish. Study areas included two OWTS-influenced near-shore sites with native bluegill spawning habitats and two in-lake control sites without nearby EAC sources. Caged bluegill sunfish were analyzed for plasma vitellogenin concentrations, organosomatic indices, and histological pathologies. Surface and porewater was collected from each site and analyzed for EACs. Porewater was also collected for laboratory exposure of larval fathead minnow, before analysis of predator escape performance and gene expression profiles. Chemical analysis showed EACs present at low concentrations at each study site, whereas discrete variations were reported between sites and between summer and fall samplings. Body condition index and liver vacuolization of sunfish were found to differ among study sites as did gene expression in exposed larval fathead minnows. Interestingly, biological exposure data and water chemistry did not match. Therefore, although results highlight the potential impacts of seepage from OWTS, further investigation of mixture effects and life history factor as well as chemical fate is warranted.

  2. Consequences of Hatch Phenology on Stages of Fish Recruitment

    PubMed Central

    Bogner, David M.; Wuellner, Melissa R.

    2016-01-01

    Little is known about how hatch phenology (e.g., the start, peak, and duration of hatching) could influence subsequent recruitment of freshwater fishes into a population. We used two commonly sympatric fish species that exhibit different hatching phenologies to examine recruitment across multiple life stages. Nine yellow perch (Perca flavescens) and bluegill (Lepomis macrochirus) annual cohorts were sampled from 2004 through 2013 across larval, age-0, age-1, and age-2 life stages in a Nebraska (U.S.A.) Sandhill lake. Yellow perch hatched earlier in the season and displayed a more truncated hatch duration compared to bluegill. The timing of hatch influenced recruitment dynamics for both species but important hatching metrics were not similar between species across life stages. A longer hatch duration resulted in greater larval yellow perch abundance but greater age-1 bluegill abundance. In contrast, bluegill larval and age-0 abundances were greater during years when hatching duration was shorter and commenced earlier, whereas age-0 yellow perch abundance was greater when hatching occurred earlier. As a result of hatch phenology, yellow perch recruitment variability was minimized sooner (age-0 life stage) than bluegill (age-1 life stage). Collectively, hatch phenology influenced recruitment dynamics across multiple life stages but was unique for each species. Understanding the complexities of when progeny enter an environment and how this influences eventual recruitment into a population will be critical in the face of ongoing climate change. PMID:27764216

  3. The influence of fish length on tissue mercury dynamics: implications for natural resource management and human health risk.

    PubMed

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

    2013-02-06

    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.

  4. Previous exposure of predatory fish to a pesticide alters palatability of larval amphibian prey.

    PubMed

    Hanlon, Shane M; Parris, Matthew J

    2013-12-01

    Habitat preferences of organisms are reliant on a variety of factors. For amphibians specifically, preferences can depend on factors such as food availability, water quality, and the presence of potential predators. Because some amphibians breed in permanent bodies of water (e.g., ponds), the threat of predation (e.g., from fish) is constant. Thus, some amphibians are unpalatable to many predators, allowing them to coexist in the same habitats. However, the addition of anthropogenic stressors (i.e., pesticides) may alter the perceived palatability of prey items to predators. The authors tested the hypothesis that bluegill fish (Lepomis macrochirus), previously exposed to the pesticide carbaryl, would consume more unpalatable prey (Fowler's toad [Anaxyrus fowleri] tadpoles) than unexposed predators. Carbaryl is a pesticide that attacks the nervous system and is linked to taste sense in organisms. Moreover, the authors conducted an identical test using palatable prey (gray treefrog [Hyla versicolor] tadpoles) and predicted that no change in preference would be observed. In support of the primary hypothesis, bluegill exposed to the highest concentration of carbaryl consumed more A. fowleri tadpoles compared with those exposed to carbaryl at the lowest concentration or water control. Moreover, an effect of carbaryl on predation success on H. versicolor tadpoles was not observed. The present study shows that an anthropogenic stressor (carbaryl) can alter the perceived palatability of noxious prey to fish predators, potentially altering predator-prey relationships in natural settings. © 2013 SETAC.

  5. Characterization of the gut microbiota of three commercially valuable warmwater fish species.

    PubMed

    Larsen, A M; Mohammed, H H; Arias, C R

    2014-06-01

    Due to the strong influence of the gut microbiota on fish health, dominant bacterial species in the gut are strong candidates for probiotics. This study aimed to characterize the gut microbiota of channel catfish Ictalurus punctatus, largemouth bass Micropterus salmoides and bluegill Lepomis macrochirus to provide a baseline for future probiotic studies. The gut microbiota of five pooled individuals from each fish species was identified using 16S rRNA pyrosequencing. Microbiota differed significantly between fish species in terms of bacterial species evenness. However, all gut communities analysed were dominated by the phylum Fusobacteria, specifically the species Cetobacterium somerae. Relatively high abundances of the human pathogens Plesiomonas shigelloides and Fusobacterium mortiferum, as well as members of the genus Aeromonas, suggest these species are normal inhabitants of the gut. The overwhelming dominance of the genus Cetobacterium in all species warrants further investigation into its role in the fish gut microbiota. This study provides the first characterization of the gut microbiota of three economically significant fishes and establishes a baseline for future probiotic trials. © 2014 The Society for Applied Microbiology.

  6. Snake (Colubridae: Thamnophis) predatory responses to chemical cues from native and introduced prey species

    USGS Publications Warehouse

    Mullin, S.J.; Imbert, H.; Fish, J.M.; Ervin, E.L.; Fisher, R.N.

    2004-01-01

    Several aquatic vertebrates have been introduced into freshwater systems in California over the past 100 years. Some populations of the two-striped garter snake (Thamnophis hammondii) have lived in sympatry with these species since their introduction; other populations have never encountered them. To assess the possible adaptation to a novel prey, we tested the predatory responses of T. hammondii from different populations to different chemosensory cues from native and introduced prey species. We presented chemical extracts from potential prey types and 2 control odors to individual snakes on cotton swabs and recorded the number of tongue flicks and attacks directed at each swab. Subject response was higher for prey odors than control substances. Odors from introduced centrarchid fish (Lepomis) elicited higher response levels than other prey types, including native anuran larvae (Pseudacris regilla). The pattern of response was similar for both populations of snakes (experienced and nai??ve, with respect to the introduced prey). We suggest that the generalist aquatic lifestyle of T. hammondii has allowed it to take advantage of increasing populations of introduced prey. Decisions on the management strategies for some of these introduced prey species should include consideration of how T. hammondii populations might respond in areas of sympatry.

  7. System for maintaining sediment suspensions during larval fish studies

    USGS Publications Warehouse

    Chilton, E.W.

    1991-01-01

    A new system was developed for maintaining suspensions of inorganic solids during laboratory studies on early life stages of fish. Microfine bentonite was successfully held in suspension in specially constructed units during a 21-d fishless test, a 28-d experiment with juvenile green sunfish (lepomis cyanellus), and four shorter experiments (5-9 d) with four species of larval fishes, white sucker (catostomus commersoni), northern pike (esox lucius), channel catfish (ictalurus punctatus), and walleye (stizostedion vitreum). Each experiment on larval fish was conducted until the yolk-sac had been absorbed. Concentrations of bentonite ranged from 0 to 728 mg/l. Each unit consisted of a holding chamber set in a stainless steel bowl and two submersible pumps that recirculated the suspension. Turbidity readings remained nearly constant throughout each experiment. Because the turbidity of suspensions was well correlated with bentonite concentration (r2 = 0.989) And easy to measure, turbidity was used as an indicator of concentration. The system is inexpensive, easy to assemble, and does not require a diluter system to maintain constant concentrations of suspended material.

  8. Differential tolerance of native and nonnative fish exposed to ultraviolet radiation and fluoranthene in Lake Tahoe (California/Nevada), USA.

    PubMed

    Gevertz, Amanda K; Tucker, Andrew J; Bowling, Anna M; Williamson, Craig E; Oris, James T

    2012-05-01

    Within Lake Tahoe (CA/NV), USA, multiple environmental stressors are present that can affect both native and nonnative fish species. Stressors include natural ultraviolet radiation (UVR) and polycyclic aromatic hydrocarbons (PAHs). Many PAHs, such as fluoranthene (FLU) are phototoxic to aquatic organisms in the presence of UVR. Decreasing levels of UVR due to eutrophication and increasing levels of PAHs due to recreational activities may combine to affect the relative ability of native versus nonnative fish species to survive in the lake. The objective of the present study was to examine the differential effects of exposure to different levels of UVR and phototoxic FLU in native and nonnative fish species. Responses to these changes in the native Lahontan redside minnow (Richardsonius egregius) and the nonnative warm-water bluegill sunfish (Lepomis macrochirus) were compared during toxicity tests, which were conducted in controlled outdoor exposures. Physiological defenses were also investigated in an attempt to elucidate ways each species may tolerate UVR and UVR + FLU exposures. It was determined that the native redside minnow is more tolerant to UVR and UVR + FLU exposure when compared to the nonnative bluegill. In addition, a natural UVR coping mechanism, increased pigmentation, is exhibited to a greater extent in the native redside. The present study will help determine the potential for a future successful invasion of the bluegill and similar species in Lake Tahoe and other oligotrophic, montane lakes that are susceptible to habitat alteration, nutrient inputs, and recreational activity.

  9. LONG-TERM CHANGES IN MERCURY CONCENTRATIONS IN FISH FROM THE MIDDLE SAVANNAH RIVER

    SciTech Connect

    Paller, M; Bill Littrell, B

    2007-01-02

    Total mercury levels were measured in largemouth bass (Micropterus salmoides), ''sunfishes'' (Lepomis spp)., and ''catfish'' (primarily Ameiurus spp.) from 1971 to 2004 in the middle reaches of the Savannah River, which drains the coastal plain of the southeastern U.S. Mercury levels were highest in 1971 but declined over the next ten years due to the mitigation of point sources of industrial pollution. Mercury levels began to increase in the 1980s as a possible consequence of mercury inputs from tributaries and associated wetlands where mercury concentrations were significantly elevated in water and fish. Mercury levels in Savannah River fish decreased sharply in 2001-2003 coincident with a severe drought in the Savannah River basin, but returned to previous levels in 2004 with the resumption of normal precipitation. Regression models showed that mercury levels in Savannah River fish changed significantly over time and were affected by river discharge. Despite temporal changes, there was little overall difference in Savannah River fish tissue mercury levels between 1971 and 2004.

  10. Isolation and molecular characterization of a novel picornavirus from baitfish in the USA

    USGS Publications Warehouse

    Phelps, Nicholas B.D.; Mor, Sunil K.; Armien, Anibal G.; Batts, William N.; Goodwin, Andrew E.; Hopper, Lacey; McCann, Rebekah; Ng, Terry Fei Fan; Puzach, Corey; Waltzek, Thomas B.; Delwart, Eric; Winton, James; Goyal, Sagar M.

    2014-01-01

    During both regulatory and routine surveillance sampling of baitfish from the states of Illinois, Minnesota, Montana, and Wisconsin, USA, isolates (n = 20) of a previously unknown picornavirus were obtained from kidney/spleen or entire viscera of fathead minnows (Pimephales promelas) and brassy minnows (Hybognathus hankinsoni). Following the appearance of a diffuse cytopathic effect, examination of cell culture supernatant by negative contrast electron microscopy revealed the presence of small, round virus particles (∼30–32 nm), with picornavirus-like morphology. Amplification and sequence analysis of viral RNA identified the agent as a novel member of the Picornaviridae family, tentatively named fathead minnow picornavirus (FHMPV). The full FHMPV genome consisted of 7834 nucleotides. Phylogenetic analysis based on 491 amino acid residues of the 3D gene showed 98.6% to 100% identity among the 20 isolates of FHMPV compared in this study while only 49.5% identity with its nearest neighbor, the bluegill picornavirus (BGPV) isolated from bluegill (Lepomis macrochirus). Based on complete polyprotein analysis, the FHMPV shared 58% (P1), 33% (P2) and 43% (P3) amino acid identities with BGPV and shared less than 40% amino acid identity with all other picornaviruses. Hence, we propose the creation of a new genus (Piscevirus) within the Picornaviridae family. The impact of FHMPV on the health of fish populations is unknown at present.

  11. Brain Transcriptional Profiles of Male Alternative Reproductive Tactics and Females in Bluegill Sunfish

    PubMed Central

    Partridge, Charlyn G.; MacManes, Matthew D.; Knapp, Rosemary; Neff, Bryan D.

    2016-01-01

    Bluegill sunfish (Lepomis macrochirus) are one of the classic systems for studying male alternative reproductive tactics (ARTs) in teleost fishes. In this species, there are two distinct life histories: parental and cuckolder, encompassing three reproductive tactics, parental, satellite, and sneaker. The parental life history is fixed, whereas individuals who enter the cuckolder life history transition from sneaker to satellite tactic as they grow. For this study, we used RNAseq to characterize the brain transcriptome of the three male tactics and females during spawning to identify gene ontology (GO) categories and potential candidate genes associated with each tactic. We found that sneaker males had higher levels of gene expression differentiation compared to the other two male tactics. Sneaker males also had higher expression in ionotropic glutamate receptor genes, specifically AMPA receptors, compared to other males, which may be important for increased spatial working memory while attempting to cuckold parental males at their nests. Larger differences in gene expression also occurred among male tactics than between males and females. We found significant expression differences in several candidate genes that were previously identified in other species with ARTs and suggest a previously undescribed role for cAMP-responsive element modulator (crem) in influencing parental male behaviors during spawning. PMID:27907106

  12. Relationship of weed shiner and young-of-year bluegill and largemouth bass abundance to submersed aquatic vegetation in Navigation Pools 4, 8, and 13 of the Upper Mississippi River, 1998-2012

    USGS Publications Warehouse

    DeLain, Steven A.; Popp, Walter A.

    2014-01-01

    Aquatic vegetation provides food resources and shelter for many species of fish. This study found a significant relationship between increases in submersed aquatic vegetation (SAV) in four study reaches of the Upper Mississippi River (UMR) and increases in catch-per-unit-effort (CPUE) of weed shiners (Notropis texanus) and age-0 bluegills (Lepomis macrochirus) and largemouth bass (Micropterus salmoides) when all of the study reaches were treated collectively using Long Term Resource Monitoring Program (LTRMP) vegetation and fish data for 1998–2012. The selected fishes were more abundant in study reaches with higher SAV frequencies (Pool 8 and Lower Pool 4) and less abundant in reaches with lower SAV frequencies (Pool 13 and Upper Pool 4). When each study reach was examined independently, the relationship between SAV frequency and CPUE of the three species was not significant in most cases, the primary exception being weed shiners in Lower Pool 4. Results of this study indicate that the prevalence of SAV does affect relative abundance of these vegetation-associated fish species. However, the poor annual relationship between SAV frequency and age-0 relative abundance in individual study reaches indicates that several other factors also govern age-0 abundance. The data indicate that there may be a SAV frequency threshold in backwaters above which there is not a strong relationship with abundance of these fish species. This is indicated by the high annual CPUE variability of the three selected fishes in backwaters of Pool 8 and Lower Pool 4 when SAV exceeded certain frequencies.

  13. Occurrence and Distribution of Organochlorine Compounds in Biological Tissue and Bed Sediment From Streams in the Trinity River Basin, Texas, 1992-93

    USGS Publications Warehouse

    Moring, J. Bruce

    1997-01-01

    This report describes the occurrence and distribution of organochlorine compounds in biological tissue and bed sediment from the Trinity River Basin study area of the National Water-Quality Assessment Program. Concentrations of organochlorine pesticides, polychlorinated biphenyls (PCBs), and other organochlorine compounds were determined in biological tissue and surficial bed sediment from 16 stream sites in the Trinity River Basin of east-central Texas. Asiatic clams (Corbicula fluminea) were collected at 10 sites, and fish, including blue catfish (Ictalurus furcatus), common carp (Cyprinus carpio), bluegill (Lepomis cyanellus), and yellow bullhead (Ameiurus natalis) were collected at all mainstem and two tributary sites. Thirty of the 36 compounds analyzed in biological tissue or surficial bed sediment were detected in one or both media. Overall, more organochlorine compounds were detected in bed sediment than in biological tissue; however, various chlordane isomers, DDT metabolites, and PCBs were detected more frequently in tissue than in sediment. The chlordane isomers and PCBs that were detected more frequently in biological tissue also were detected more frequently at urban sites than at agricultural sites. Organochlorine compound concentrations generally were highest in fish tissue from Trinity River mainstem sites. Fish tissue from the mainstem sites contained a higher percentage of lipids than did fish- and clam-tissue samples from the tributary sites.

  14. Ultraviolet radiation affects invasibility of lake ecosystems by warm-water fish.

    PubMed

    Tucker, Andrew J; Williamson, Craig E; Rose, Kevin C; Oris, James T; Connelly, Sandra J; Olson, Mark H; Mitchell, David L

    2010-03-01

    Predicting where species invasions will occur remains a substantial challenge in ecology, but identifying factors that ultimately constrain the distribution of potential invaders could facilitate successful prediction. Whereas ultraviolet radiation (UVR) is recognized as an important factor controlling species distribution and community composition, the role of UVR in a habitat invasibility context has not been explored. Here we examine how underwater UVR can regulate warm-water fish invasion. In Lake Tahoe, California and Nevada, USA, established populations of exotic bluegill sunfish (Lepomis macrochirus) are currently limited to turbid, low-UVR embayments. An in situ incubation experiment that manipulated incident UVR exposure of larval bluegill, combined with an assessment of UVR exposure levels in nearshore habitats around Lake Tahoe, demonstrates that UVR can mediate habitat invasibility. Our findings suggest that the susceptibility to invasion by UVR sensitive species may increase in transparent aquatic systems threatened by declining water quality, and they highlight the importance of abiotic factors as regulators of invasion risk in ecosystems.

  15. Gill lesions and death of bluegill in an acid mine drainage mixing zone

    USGS Publications Warehouse

    Henry, T.B.; Irwin, E.R.; Grizzle, J.M.; Brumbaugh, W.G.; Wildhaber, M.L.

    2001-01-01

    The toxicity of an acid mine drainage (AMD) mixing zone was investigated by placing bluegill (Lepomis macrochirus) at the confluence of a stream contaminated by AMD and a stream having neutral pH. A mixing channel receiving water from both streams was assembled in the field, during July and October 1996, to determine the toxicity of freshly mixed and aged water (2.9-7.5 min). The AMD stream had elevated concentrations of Al and Fe, which precipitated upon mixing, and of Mn, which did not precipitate in the mixing zone. Fish exposed to freshly mixed water had higher mortality than fish exposed to water after aging. Precipitating Al, but not Fe, accumulated on the gills of bluegill, and accumulation was more rapid early during the mixing process than after aging. Fish exposed for 3.5 h to freshly mixed water had hypertrophy and hyperplasia of gill filament and lamellar epithelial cells. Similar lesions were observed after 6.0 h in fish exposed to water aged after mixing. Results demonstrated that Al was the predominant metal accumulating on the gills of fish in this AMD mixing zone, and that mixing zones can be more toxic than AMD streams in equilibrium.

  16. 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

  17. Phylogeography and conservation genetics of a distinct lineage of sunfish in the Cuatro Ciénegas valley of Mexico.

    PubMed

    Coghill, Lyndon M; Hulsey, C Darrin; Chaves-Campos, Johel; García de Leon, Francisco J; Johnson, Steven G

    2013-01-01

    The valley of Cuatro Ciénegas, an aquatic oasis located in the Mexican Chihuahuan Desert, exhibits the highest level of endemism in North America and is a Mexican National Protected Area. However, little is known about the evolutionary distinctiveness of several vertebrate species present in the Cuatro Ciénegas valley. We conducted a phylogeographic study using mitochondrial haplotypes from the centrarchid fish Lepomis megalotis to determine if the populations found within the valley were evolutionarily distinct from populations outside the valley. We also examined if there was evidence of unique haplotypes of this sunfish within the valley. Genetic divergence of L. megalotis suggests populations within the valley are evolutionarily unique when compared to L. megalotis outside the valley. Significant mitochondrial sequence divergence was also discovered between L. megalotis populations on either side of the Sierra de San Marcos that bisects the valley. Our results reinforce previous studies that suggest the organisms occupying aquatic habitats not only within Cuatro Ciénegas but also in each of the two lobes of the valley generally deserve independent consideration during management decisions.

  18. Phylogeography and Conservation Genetics of a Distinct Lineage of Sunfish in the Cuatro Ciénegas Valley of Mexico

    PubMed Central

    Coghill, Lyndon M.; Hulsey, C. Darrin; Chaves-Campos, Johel; García de Leon, Francisco J.; Johnson, Steven G.

    2013-01-01

    The valley of Cuatro Ciénegas, an aquatic oasis located in the Mexican Chihuahuan Desert, exhibits the highest level of endemism in North America and is a Mexican National Protected Area. However, little is known about the evolutionary distinctiveness of several vertebrate species present in the Cuatro Ciénegas valley. We conducted a phylogeographic study using mitochondrial haplotypes from the centrarchid fish Lepomis megalotis to determine if the populations found within the valley were evolutionarily distinct from populations outside the valley. We also examined if there was evidence of unique haplotypes of this sunfish within the valley. Genetic divergence of L. megalotis suggests populations within the valley are evolutionarily unique when compared to L. megalotis outside the valley. Significant mitochondrial sequence divergence was also discovered between L. megalotis populations on either side of the Sierra de San Marcos that bisects the valley. Our results reinforce previous studies that suggest the organisms occupying aquatic habitats not only within Cuatro Ciénegas but also in each of the two lobes of the valley generally deserve independent consideration during management decisions. PMID:24130826

  19. Potential direct and indirect effects of climate change on a shallow natural lake fish assemblage

    USGS Publications Warehouse

    Breeggemann, Jason J.; Kaemingk, Mark A.; DeBates, T.J.; Paukert, Craig P.; Krause, J.; Letvin, Alexander P.; Stevens, Tanner M.; Willis, David W.; Chipps, Steven R.

    2015-01-01

    Much uncertainty exists around how fish communities in shallow lakes will respond to climate change. In this study, we modelled the effects of increased water temperatures on consumption and growth rates of two piscivores (northern pike [Esox lucius] and largemouth bass [Micropterus salmoides]) and examined relative effects of consumption by these predators on two prey species (bluegill [Lepomis macrochirus] and yellow perch [Perca flavescens]). Bioenergetics models were used to simulate the effects of climate change on growth and food consumption using predicted 2040 and 2060 temperatures in a shallow Nebraska Sandhill lake, USA. The patterns and magnitude of daily and cumulative consumption during the growing season (April–October) were generally similar between the two predators. However, growth of northern pike was always reduced (−3 to −45% change) compared to largemouth bass that experienced subtle changes (4 to −6% change) in weight by the end of the growing season. Assuming similar population size structure and numbers of predators in 2040–2060, future consumption of bluegill and yellow perch by northern pike and largemouth bass will likely increase (range: 3–24%), necessitating greater prey biomass to meet future energy demands. The timing of increased predator consumption will likely shift towards spring and fall (compared to summer), when prey species may not be available in the quantities required. Our findings suggest that increased water temperatures may affect species at the edge of their native range (i.e. northern pike) and a potential mismatch between predator and prey could exist.

  20. Use of main channel and two backwater habitats by larval fishes in the Detroit River

    USGS Publications Warehouse

    McDonald, Erik A.; McNaught, A. Scott; Roseman, Edward F.

    2014-01-01

    Recent investigations in the Detroit River have revealed renewed spawning activity by several important fishes, but little is known about their early life history requirements. We surveyed two main channel and two backwater areas in the lower Detroit River weekly from May to July 2007 to assess habitat use by larval fishes. Backwater areas included a soft-sediment embayment (FI) and a hard-sediment area (HIW). Main channel sites were located adjacent to each backwater area. Water temperature, velocity and clarity measurements and zooplankton samples were collected weekly. A macrophyte assessment was conducted in July. Growth and diet of larval yellow perch (Perca flavescens), bluegill (Lepomis macrochirus) and round goby (Neogobius melanostomus) were used to assess habitat quality. Macrophyte diversity and percent cover were higher and velocity lower at FI than HIW. Although larval fish diversity was highest in the main channel, yellow perch and bluegill larvae only grew beyond the yolk stage at FI, where they preferentially selected copepods, while Daphnia were selected in the main channel. Round goby ate harpacticoid copepods and Daphnia and grew at similar rates in HIW and the main channel. These data indicate that FI was a valuable nursery area for yellow perch and bluegill, whereas HIW was better suited to round goby. We only assessed two backwater areas, thus a complete census of wetland areas in the Detroit River is needed to identify valuable habitats. Restoration of shallow backwater areas is essential for rehabilitating fish populations and should be a priority in the Detroit River.

  1. Using environmental DNA to estimate the distribution of an invasive fish species in ponds.

    PubMed

    Takahara, Teruhiko; Minamoto, Toshifumi; Doi, Hideyuki

    2013-01-01

    Knowledge of the presence of an invasive species is critical to monitoring the sustainability of communities and ecosystems. Environmental DNA (eDNA), DNA fragments that are likely to be bound to organic matters in the water or in shed cells, has been used to monitor the presence of aquatic animals. Using an eDNA-based method, we estimated the presence of the invasive bluegill sunfish, Lepomis macrochirus, in 70 ponds located in seven locales on the Japanese mainland and on surrounding islands. We quantified the concentration of DNA copies in a 1 L water sample using quantitative real-time polymerase chain reaction (qPCR) with a primer/probe set. In addition, we visually observed the bluegill presence in the ponds from the shoreline. We detected bluegill eDNA in all the ponds where bluegills were observed visually and some where bluegills were not observed. Bluegills were also less prevalent on the islands than the mainland, likely owing to limited dispersal and introduction by humans. Our eDNA method simply and rapidly detects the presence of this invasive fish species with less disturbance to the environment during field surveys than traditional methods.

  2. Brain Transcriptional Profiles of Male Alternative Reproductive Tactics and Females in Bluegill Sunfish.

    PubMed

    Partridge, Charlyn G; MacManes, Matthew D; Knapp, Rosemary; Neff, Bryan D

    2016-01-01

    Bluegill sunfish (Lepomis macrochirus) are one of the classic systems for studying male alternative reproductive tactics (ARTs) in teleost fishes. In this species, there are two distinct life histories: parental and cuckolder, encompassing three reproductive tactics, parental, satellite, and sneaker. The parental life history is fixed, whereas individuals who enter the cuckolder life history transition from sneaker to satellite tactic as they grow. For this study, we used RNAseq to characterize the brain transcriptome of the three male tactics and females during spawning to identify gene ontology (GO) categories and potential candidate genes associated with each tactic. We found that sneaker males had higher levels of gene expression differentiation compared to the other two male tactics. Sneaker males also had higher expression in ionotropic glutamate receptor genes, specifically AMPA receptors, compared to other males, which may be important for increased spatial working memory while attempting to cuckold parental males at their nests. Larger differences in gene expression also occurred among male tactics than between males and females. We found significant expression differences in several candidate genes that were previously identified in other species with ARTs and suggest a previously undescribed role for cAMP-responsive element modulator (crem) in influencing parental male behaviors during spawning.

  3. Thermoregulation of fish and other aquatic vertebrates in thermally stressed habitats: roles of behavior, competition, predation and nutrients. Progress report, 1 January 1984-31 December 1986

    SciTech Connect

    Spotila, J.R.; Standora, E.A.

    1986-06-01

    The mechanisms by which fish and turtles thermoregulate in thermally stressed habitats were quantitatively determined. Experiments on the roles of behavior, competition and predation on the thermoregulation of largemouth bass (Micropterus salmoides) and bluegill (Lepomis macrochirus) in extreme environments are described. The presence of the bass changes the upper avoidance temperature of a bluegill. Bass from Par Pond and Pond C on the Savannah River Plant have the same selected temperature but the responses of small bass to tests of selected temperature and upper avoidance temperature are altered by the presence of large conspecific. Field enclosure experiments documented the complex nature of the bluegill-bass interaction in Pond C. The effect of diet protein content and temperature on the growth and assimilation efficiency of the turtle Pseudemys scripta are related. Growth rate increased when turtles were fed diets with a higher protein content. Yearling snapping turtles, Chelydra serpentina, did not grow when kept at 15/sup 0/C. Those kept at 25/sup 0/C grew rapidly. There was no difference in selected temperature between the two groups, although CTM's were significantly different. Mathematical modeling focused on an analysis of the relationship between the thermal conductance of animals, the insulative properties of skin and fur and the external properties of animal-environmental interactions. 70 refs., 21 figs., 10 tabs.

  4. Effect of suspended sediment on vulnerability of young razorback suckers to predation

    USGS Publications Warehouse

    Johnson, J.E.; Hines, R.T.

    1999-01-01

    The decline of native fishes in North America is principally a result of altered habitats, and the impact of mainstream dams has accounted for many of the habitat changes. Diminished turbidity, and introduced nonnative predators were investigated as possible reasons for the decline of endangered razorback suckers Xyrauchen texanus in the Colorado River. In laboratory tests, young razorback suckers selected clear water over two water samples with higher concentrations of suspended sediment. In clear water, however, young razorback suckers were extremely susceptible to predation; native Colorado squawfish Ptychocheilus lucius consumed 90% of test razorback suckers, and nonnative green sunfish Lepomis cyanellus consumed 99.6%. As turbidity increased, razorback sucker predator avoidance improved and differences in predator success disappeared. Winter-spring spawning by razorback suckers in Lake Mohave, along with the extreme susceptibility of larvae to predation in clear water, may account for total recruitment failure in that lake. However, in upper basin rivers, suspended sediments remain high enough to limit predation by fishes tested, suggesting that other impacts, including contaminants and lack of floodplain habitat, may be thwarting recruitment in those rivers.

  5. Implications of stunting on morphology of freshwater fishes

    USGS Publications Warehouse

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

    2010-01-01

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

  6. Use of preserved museum fish to evaluate historical and current mercury contamination in fish from two rivers in Oklahoma, USA.

    PubMed

    Hill, J Jaron; Chumchal, Matthew M; Drenner, Ray W; Pinder, John E; Drenner, S Matthew

    2010-02-01

    We examined the effects of a commonly used preservation technique on mercury concentration in fish tissue. After fixing fish muscle tissue in formalin followed by preservation in isopropanol, we found that mercury concentration in fish muscle tissue increased by 18%, reaching an asymptote after 40 days. We used formalin-isopropanol-preserved longear sunfish (Lepomis megalotis) from the Sam Noble Oklahoma Museum of Natural History to examine historical changes and predict current mercury concentrations in fish from two rivers in southeastern Oklahoma. Glover River was free-flowing, while Mountain Fork River was impounded in 1970 and a coldwater trout fishery was established upstream from the collection site in 1989. Mercury concentrations in longear sunfish from Glover River showed no historical changes from 1963 to 2001. Mercury concentrations in longear sunfish from Mountain Fork River showed no change from 1925 to 1993 but declined significantly from 1993 to 2003. We also compared mercury concentrations of the most recently collected longear sunfish in the museum to mercury concentrations of unpreserved fish collected from the rivers in 2006. Concentrations of mercury in museum fish were not significantly different from mercury concentrations in unpreserved fish we collected from the rivers. Our study indicates that preserved museum fish specimens can be used to evaluate historical changes and predict current levels of mercury contamination in fish.

  7. Gill lesions and death of bluegill in an acid mine drainage mixing zone.

    PubMed

    Henry, T B; Irwin, E R; Grizzle, J M; Brumbaugh, W G; Wildhaber, M L

    2001-06-01

    The toxicity of an acid mine drainage (AMD) mixing zone was investigated by placing bluegill (Lepomis macrochirus) at the confluence of a stream contaminated by AMD and a stream having neutral pH. A mixing channel receiving water from both streams was assembled in the field, during July and October 1996, to determine the toxicity of freshly mixed and aged water (2.9-7.5 min). The AMD stream had elevated concentrations of Al and Fe, which precipitated upon mixing, and of Mn, which did not precipitate in the mixing zone. Fish exposed to freshly mixed water had higher mortality than fish exposed to water after aging. Precipitating Al, but not Fe, accumulated on the gills of bluegill, and accumulation was more rapid early during the mixing process than after aging. Fish exposed for 3.5 h to freshly mixed water had hypertrophy and hyperplasia of gill filament and lamellar epithelial cells. Similar lesions were observed after 6.0 h in fish exposed to water aged after mixing. Results demonstrated that Al was the predominant metal accumulating on the gills of fish in this AMD mixing zone, and that mixing zones can be more toxic than AMD streams in equilibrium.

  8. Microscopic examination of skin in native and nonnative fish from Lake Tahoe exposed to ultraviolet radiation and fluoranthene.

    PubMed

    Gevertz, Amanda K; Oris, James T

    2014-02-01

    The presence of nonnative species in Lake Tahoe (CA/NV), USA has been an ongoing concern for many decades, and the management of these species calls for an understanding of their ability to cope with the Lake's stressors and for an understanding of their potential to out-compete and reduce the populations of native species. Decreasing levels of ultraviolet radiation (UVR) due to eutrophication and increasing levels of phototoxic polycyclic aromatic hydrocarbons (PAHs) due to recreational activities may combine to affect the relative ability of native versus nonnative fish species to survive in the lake. Following a series of toxicity tests which exposed larvae of the native Lahontan redside minnow (Richardsonius egregius) and the nonnative warm-water bluegill sunfish (Lepomis macrochirus) to UVR and FLU, the occurrence of skin damage and/or physiologic defense mechanisms were studied using multiple microscopic techniques. The native minnow appeared to exhibit fewer instances of skin damage and increased instances of cellular coping mechanisms. This study supports the results of previous work conducted by the authors, who determined that the native redside minnow is the more tolerant of the two species, and that setting and adhering to a water quality standard for UVR transparency may aid in preventing the spread of the less tolerant nonnative bluegill and similar warm-water species.

  9. Assessing variability in chemical acute toxicity of unionid mussels: Influence of intra- and inter-laboratory testing, life stage, and species

    USGS Publications Warehouse

    Raimondo, Sandy; Lilavois, Crystal R.; Lee, Larisa; Augspurger, Tom; Wang, Ning; Ingersoll, Christopher G.; Bauer, Candice R.; Hammer, Edward J.; Barron, Mace G.

    2016-01-01

    We developed a toxicity database for unionid mussels to examine the extent of intra- and inter-laboratory variability in acute toxicity tests with mussel larvae (glochidia) and juveniles; the extent of differential sensitivity of the two life stages; and the variation in sensitivity among commonly tested mussels (Lampsilis siliquoidea, Utterbackia imbecillis, Villosa iris), commonly tested cladocerans (Daphnia magna, Ceriodaphnia dubia) and fish (Oncorhynchus mykiss, Pimephales promelas, Lepomis macrochirus). The results of these analyses indicate intra-laboratory variability for median effect concentrations (EC50) averaged about 2 fold for both life stages, while inter-laboratory variability averaged 3.6 fold for juvenile mussels and 6.3 fold for glochidia. The EC50s for juveniles and glochidia were within a factor of 2 of each other for 50% of paired records across chemicals, with juveniles more sensitive than glochidia by more than 2 fold for 33% of the comparisons made between life stages. There was a high concurrence of the sensitivity of commonly tested L. siliquoidea, U. imbecillis, and V. iris to that of other mussels. However, this concurrence decreases as the taxonomic distance of the commonly tested cladocerans and fish to mussels increases. The compiled mussel database and determination of data variability will advance risk assessments by including more robust species sensitivity distributions, interspecies correlation estimates, and availability of taxon-specific empirically derived application factors for risk assessment.

  10. Isolation of Acholeplasma laidlawii from centrarchids in a Central Florida Lake

    USGS Publications Warehouse

    Francis-Floyd, R.; Reed, P.; Gibbs, P.; Shotts, E.; Bolon, B.; Coleman, W.; Klinger, R.

    1998-01-01

    In 1991, the poor physical condition of largemouth bass Micropterus salmoides from Lake Harris, Florida, was associated with the decline of the lake's fishery. The swim bladders of emaciated bass had mild inflammation and ecchymotic hemorrhages. A mycoplasma-like organism isolated from swim bladders was initially believed to be the causative agent. The organism was later identified as Acholeplasma laidlawii by using a fluorescent antibody procedure and was demonstrated to be nonpathogenic. Parenteral injection of the organism into healthy largemouth bass fingerlings produced no signs of disease or difference in growth rate compared with control fish during a 16-month period. Field studies resulted in isolation of A. laidlawii from black crappies Pomoxis nigromaculatus, bluegills Lepomis macrochirus, and redear sunfish L. microlophus, but not from noncentrarchids in Lake Harris or from any fish species in a control fishery (Lake Holly, Florida). The absence of organisms in all emaciated bass, our inability to reproduce the disease, and isolation of the organism from seemingly healthy fish suggest this organism was not pathogenic.

  11. Importance of floodplain connectivity to fish populations in the Apalachicola River, Florida

    USGS Publications Warehouse

    Burgess, O.T.; Pine, William E.; Walsh, S.J.

    2013-01-01

    Floodplain habitats provide critical spawning and rearing habitats for many large-river fishes. The paradigm that floodplains are essential habitats is often a key reason for restoring altered rivers to natural flow regimes. However, few studies have documented spatial and temporal utilization of floodplain habitats by adult fish of sport or commercial management interest or assessed obligatory access to floodplain habitats for species' persistence. In this study, we applied telemetry techniques to examine adult fish movements between floodplain and mainstem habitats, paired with intensive light trap sampling of larval fish in these same habitats, to assess the relationships between riverine flows and fish movement and spawning patterns in restored and unmodified floodplain distributaries of the Apalachicola River, Florida. Our intent is to inform resource managers on the relationships between the timing, magnitude and duration of flow events and fish spawning as part of river management actions. Our results demonstrate spawning by all study species in floodplain and mainstem river habitat types, apparent migratory movements of some species between these habitats, and distinct spawning events for each study species on the basis of fish movement patterns and light trap catches. Additionally, Micropterus spp., Lepomis spp. and, to a lesser degree, Minytrema melanops used floodplain channel habitat that was experimentally reconnected to the mainstem within a few weeks of completing the restoration. This result is of interest to managers assessing restoration activities to reconnect these habitats as part of riverine restoration programmes globally.

  12. Population characteristics and ecological role of northern pike in shallow natural lakes in Nebraska

    USGS Publications Warehouse

    Paukert, C.P.; Willis, D.W.

    2003-01-01

    Northern pike Esox lucius were sampled in Nebraska's Sandhill lakes during 1998 and 1999 to determine population characteristics and their influence on the fish community in these shallow, warm lakes at the southwestern edge of this species' natural range. Density-dependent growth, size structure, and condition were not evident in the northern pike populations sampled. Relative abundance of largemouth bass Micropterus salmoides was positively related to size structure of yellow perch Perca flavescens and bluegills Lepomis macrochirus when northen pike were absent. When northern pike and largemouth bass populations were sympatric, these relationships were less evident. Population size structure of yellow perch was lower in lakes with northern pike, but decreased size structure was not evident for bluegills. Northern pike growth decreased with July bottom water temperature, which ranged from 20??C to 25??C. Recruitment patterns of northern pike in the Sandhill lakes appeared to be lake-specific, strong and weak year-classes occurring in the same year among different populations. Northern pike in these shallow, warm lakes act as a top-down predator and appear to structure fish communities predominated by largemouth bass and panfish. Biologists managing warmwater Midwestern lakes thus should consider the effect of northern pike on fish communities.

  13. Steroid hormones in bluegill, a species with male alternative reproductive tactics including female mimicry.

    PubMed

    Knapp, Rosemary; Neff, Bryan D

    2007-12-22

    The proximate mechanisms underlying the evolution and maintenance of within-sex variation in mating behaviour are still poorly understood. Species characterized by alternative reproductive tactics provide ideal opportunities to investigate such mechanisms. Bluegill (Lepomis macrochirus) are noteworthy in this regard because they exhibit two distinct cuckolder (parasitic) morphs (called sneaker and satellite) in addition to the parental males that court females. Here we confirm previous findings that spawning cuckolder and parental males have significantly different levels of testosterone and 11-ketotestosterone. We also report, for the first time, that oestradiol and cortisol levels are higher in cuckolders than in parental males. The two cuckolder morphs did not differ in average levels of any of the four hormones. However, among satellite males which mimic females in appearance and behaviour, there was a strong negative relationship between oestradiol levels and body length, a surrogate for age. This finding suggests that for satellite males, oestradiol dependency of mating behaviour decreases with increasing mating experience. Although such decreased hormone dependence of mating behaviour has been reported in other taxa, our data represent the first suggestion of the relationship in fishes.

  14. Fluidized bed ash and passive treatment reduce the adverse effects of acid mine drainage on aquatic organisms.

    PubMed

    Porter, Clint M; Nairn, Robert W

    2010-10-15

    Elevated concentrations of acidity and metals in acid mine drainage (AMD) may be effectively addressed by active and passive treatment technologies. However, typical evaluations consider only chemical water quality with little if any regard for biological metrics. Robust evaluations including both chemical and biological indicators of water quality improvement are needed. In this study, injection of alkaline fluidized bed ash (FBA) into a flooded underground coal mine was coupled with a five-cell passive treatment system to ameliorate an abandoned AMD discharge in eastern Oklahoma. The passive system included process units promoting both aerobic and anaerobic treatment mechanisms. Resulting water quality changes and biological responses were evaluated. Organisms of two distinct functional groups (the filter-feeding mollusk Corbicula fluminea and the wide-spectrum feeding fish Lepomis macrochirus) were exposed to mine waters in several treatment cells. The combination of treatment technologies was hypothesized to limit potential negative effects on these aquatic organisms. Tissues were harvested and analyzed for concentrations of several metals (Al, Fe, Mn, Mg, Ca, Ni, Cu and Zn) of interest. Organismal responses, such as hepatosomatic index, condition factor, and condition index, did not vary significantly among organisms exposed within different treatment cells when compared to non-AMD impaired waters. Metal tissue accumulation trends, compared to aqueous concentrations, were observed for Fe, Ni and Zn. Exposure experiments with these two organisms indicated that FBA introductions coupled with passive treatment decreased the potential adverse effects of AMD to biological systems. Copyright © 2010 Elsevier B.V. All rights reserved.

  15. Multiple stressors in amphibian communities: Effects of chemical contamination, bullfrogs, and fish

    USGS Publications Warehouse

    Boone, M.D.; Semlitsch, R.D.; Little, E.E.; Doyle, M.C.

    2007-01-01

    A leading hypothesis of amphibian population declines is that combinations of multiple stressors contribute to declines. We examined the role that chemical contamination, competition, and predation play singly and in combination in aquatic amphibian communities. We exposed larvae of American toads (Bufo americanus), southern leopard frogs (Rana sphenocephala), and spotted salamanders (Ambystoma maculatum) to overwintered bullfrog tadpoles (R. catesbeiana), bluegill sunfish (Lepomis macrochirus), the insecticide carbaryl, and ammonium nitrate fertilizer in 1000-L mesocosms. Most significantly, our study demonstrated that the presence of multiple factors reduced survival of B. americanus and A. maculatum and lengthened larval periods of R. sphenocephala. The presence of bluegill had the largest impact on the community; it eliminated B. americanus and A. maculatum and reduced the abundance of R. sphenocephala. Chemical contaminants had the second strongest effect on the community with the insecticide, reducing A. maculatum abundance by 50% and increasing the mass of anurans (frogs and toads) at metamorphosis; the fertilizer positively influenced time and mass at metamorphosis for both anurans and A. maculatum. Presence of overwintered bullfrogs reduced mass and increased time to metamorphosis of anurans. While both bluegill and overwintered bullfrog tadpoles had negative effects on the amphibian community, they performed better in the presence of one another and in contaminated habitats. Our results indicate that predicting deleterious combinations from single-factor effects may not be straightforward. Our research supports the hypothesis that combinations of factors can negatively impact some amphibian species and could contribute to population declines. ?? 2007 by the Ecological Society of America.

  16. Fish Scale Evidence for Rapid Post Glacial Colonization of an Atlantic Coastal Pond

    NASA Technical Reports Server (NTRS)

    Daniels, R. A.; Peteet, Dorothy

    1996-01-01

    Fish scales from the sediment of Allamuchy Pond, New Jersey, USA, indicate that fishes were present in the pond within 400 years of the time of the first deposition of organic material, at approximately 12,600 yrs BP. The earliest of the scales, from a white sucker, Catostomus commersoni, appears in sediment dated 12,260 +/- 220 yrs BP. Presence of scales in sediment deposited before I 0,000 yrs BP indicates that Atlantic salmon, Salmo salar, sunfish, Lepomis sp., and yellow perch, Perca flavescens, also were early inhabitants of the pond. The timing of the arrival of each of these fishes suggests that they migrated out from Atlantic coastal refugia. A minnow scale, referred to Phoxininae, was also retrieved; it could not be matched to any cyprinid currently found in northeastern North America. The species present historically in this pond are from five families found currently in ponds throughout the Northeast and sugoest that the lentic palaeo-enviromnent was similar to present mid-elevation or high-latitude lentic systems.

  17. Small nonnative fishes as predators of larval razorback suckers

    USGS Publications Warehouse

    Carpenter, J.; Mueller, G.A.

    2008-01-01

    The razorback sucker (Xyrauchen texanus), an endangered big-river fish of the Colorado River basin, has demonstrated no sustainable recruitment in 4 decades, despite presence of spawning adults and larvae. Lack of adequate recruitment has been attributed to several factors, including predation by nonnative fishes. Substantial funding and effort has been expended on mechanically removing nonnative game fishes, typically targeting large predators. As a result, abundance of larger predators has declined, but the abundance of small nonnative fishes has increased in some areas. We conducted laboratory experiments to determine if small nonnative fishes would consume larval razorback suckers. We tested adults of three small species (threadfin shad, Dorosoma petenense; red shiner, Cyprinella lutrensis; fathead minnow, Pimephales promelas) and juveniles of six larger species (common carp, Cyprinus carpio; yellow bullhead, Ameiurus natalis; channel catfish, Ictalurus punctatus; rainbow trout, Oncorhynchus mykiss; green sunfish, Lepomis cyanellus; bluegill, L. macrochirus). These nonnative fishes span a broad ecological range and are abundant within the historical range of the razorback sucker. All nine species fed on larval razorback suckers (total length, 9-16 mm). Our results suggest that predation by small nonnative fishes could be responsible for limiting recovery of this endangered species.

  18. Ecology and control of an introduced population of Southern Watersnakes (Nerodia fasciata) in southern California

    USGS Publications Warehouse

    Reed, Robert; Todd, Brian D; Miano, Oliver J.; Canfield, Mark; Fisher, Robert N.; McMartin, Louanne

    2016-01-01

    Native to the southeastern United States, Southern Watersnakes (Nerodia fasciata) are known from two sites in California, but their ecological impacts are poorly understood. We investigated the ecology of Southern Watersnakes in Machado Lake, Harbor City, Los Angeles County, California, including an assessment of control opportunities. We captured 306 watersnakes as a result of aquatic trapping and hand captures. We captured snakes of all sizes (162–1063 mm snout–vent length [SVL], 3.5–873.3 g), demonstrating the existence of a well-established population. The smallest reproductive female was 490 mm SVL and females contained 12–46 postovulatory embryos (mean  =  21). Small watersnakes largely consumed introduced Western Mosquitofish (Gambusia affinis), while larger snakes specialized on larval and metamorph American Bullfrogs (Lithobates catesbeianus) and Green Sunfish (Lepomis cyanellus). Overall capture per unit effort (CPUE) in traps declined with time during an intensive 76-d trapping bout, but CPUE trends varied considerably among traplines and it is unlikely that the overall decline in CPUE represented a major decrease in the snake population size. Although we found no direct evidence that Southern Watersnakes are affecting native species in Machado Lake, this population may serve as a source for intentional or unintentional transportation of watersnakes to bodies of water containing imperiled native prey species or potential competitors.

  19. Inhibition of sunfish feeding by defensive steroids from aquatic beetles: Structure activity relationships.

    PubMed

    Gerhart, D J; Bondura, M E; Commito, J A

    1991-07-01

    The vertebrate hormone deoxycorticosterone is the most commonly occurring component of defensive secretions from aquatic beetles in the family Dytiscidae. Deoxycorticosterone and the structurally related steroids pregn-4-en-20α:-ol-3-one and pregn-4-en-20β-ol-3-one were tested for their ability to inhibit feeding by bluegill sunfish,Lepomis macrochirus, in laboratory assays. Deoxycorticosterone at oral doses of 660μg (2 x 10(-6) mol) per pellet caused 94% inhibition in the acceptance of artificial food pellets. At the same molar dosage, pregn-4-en-20α-ol-3-one inhibited food consumption by 58%, while its epimer, pregn-4-en-20β-ol-3-one, did not significantly inhibit feeding. These results indicate that specific stereochemical conditions must be satisfied for the pregnenes to be noxious toL. macrochirus and suggest the existence of a receptor-ligand interaction. The potency of the three steroids in assays of feeding inhibition contradicts earlier results based on toxicity and anesthetic assays in which fish were immersed in solutions of steroids.

  20. Evaluation of the flood-pulse concept based on statistical models of growth of selected fishes of the upper Mississippi River system

    USGS Publications Warehouse

    Gutreuter, S.; Bartels, A.D.; Irons, K.; Sandheinrich, M.B.

    1999-01-01

    The flood-pulse concept (FPC) states that annual inundation is the principal force responsible for productivity and biotic interactions in river-floodplain systems. Somatic growth is one component of production, and we hypothesized that, if the FPC applies, growth of fishes that use the moving littoral zone should differ among years with differing flood pattern, whereas nonlittoral fishes would show no such response. Growth of largemouth bass (Micropterus salmoides) and bluegill (Lepomis macrochirus), species that exploit littoral resources, increased during a year having an unusual warm-season flood in the Upper Mississippi River system and was reduced during low-water years. Growth of white bass (Morone chrysops), which do not rely heavily on the littoral zone, did not differ significantly between the extreme-flood and low-water years. Patterns of growth of black crappie (Pomoxis nigromaculatus), which have intermediate dependence on the moving littoral zone, were somewhat ambiguous. These results are consistent with the hypothesis that the FPC applies, at least under certain conditions, to this temperate river system. Our results can also provide an important basis from which to assess some costs and benefits of water level management strategies in large regulated temperate rivers.

  1. The antioxidant glutathione in the fish cell lines EPC and BCF-2: response to model pro-oxidants as measured by three different fluorescent dyes.

    PubMed

    Jos, A; Cameán, A M; Pflugmacher, S; Segner, H

    2009-04-01

    Reduced glutathione (GSH) protects cells against injury by oxidative stress and maintains a range of vital functions. In vitro cell cultures have been used as experimental models to study the role of GSH in chemical toxicity in mammals; however, this approach has been rarely used with fish cells to date. The present study aimed to evaluate sensitivity and specificity of three fluorescent dyes for measuring pro-oxidant-induced changes of GSH contents in fish cell lines: monochlorobimane (mBCl), 5-chloromethylfluorescein diacetate (CMFDA) and 7-amino-4-chloromethylcoumarin (CMAC-blue). Two cell lines were studied, the EPC line established from a skin tumour of carp Cyprinus carpio, and BF-2 cells established from fins of bluegill sunfish Lepomis macrochirus. The cells were exposed for 6 and 24 h to low cytotoxic concentrations of pro-oxidants including hydrogen peroxide, paraquat (PQ), copper and the GSH synthesis inhibitor, L-buthionine-SR-sulfoximine (BSO). The results indicate moderate differences in the GSH response between EPC and BF-2 cells, but distinct differences in the magnitude of the GSH response for the four pro-oxidants. Further, the choice of GSH dye can critically affect the results, with CMFDA appearing to be less specific for GSH than mBCl and CMAC-blue.

  2. Long-term changes in mercury concentrations in fish from the middle Savannah River.

    PubMed

    Paller, M H; Littrell, James W

    2007-09-01

    Total mercury levels were measured in largemouth bass (Micropterus salmoides), "sunfish" (Lepomis spp.), and "catfish" (primarily Ameiurus spp. and Ictalurus punctatus) from 1971 to 2004 in the middle Savannah River (river km 191 to 302), which drains the coastal plain of the southeastern U.S. Total mercury concentrations were higher in largemouth bass (overall mean of 0.55 mg/kg from 1971 to 2004), a piscivorous (trophic level 4) species than in the other taxa (means of 0.22-0.26 mg/kg), but temporal trends were generally similar among taxa. Mercury levels were highest in 1971 but declined over the next 10 years due to the mitigation of point source industrial pollution. Mercury levels in fish began to increase in the 1980s as a likely consequence of mercury inputs from tributaries and associated wetlands where mercury concentrations were significantly elevated in water and fish. Mercury levels in Savannah River fish decreased sharply in 2001-2003 coincident with a severe drought in the Savannah River basin, but returned to previous levels in 2004 with the resumption of normal precipitation. Regression models showed that mercury levels in fish changed significantly over time and were affected by river discharge. Mercury levels in Savannah River fish were only slightly lower in 2004 (0.3 to 0.8 mg/kg) than in 1971 (0.4 to 1.0 mg/kg) despite temporal changes during the intervening years.

  3. Tactic-specific success in sperm competition.

    PubMed

    Fu, P; Neff, B D; Gross, M R

    2001-06-07

    Sperm competition is a major force in sexual selection, but its implications for mating-system and life-history evolution are only beginning to be understood. The well-known sneak-guard model predicts that sneaks will win in sperm competition. We now provide empirical confirmation of this prediction. Bluegill sunfish (Lepomis macrochirus) have both sneak (cuckolder) and guard (parental) males. Guards make nests, court females and provide solitary parental care for the embryos. Sneaks include small cuckolders, which are termed 'sneakers', that dart in and out of nests in order to ejaculate between the spawning pair and larger cuckolders, which are termed 'satellites', that mimic females in order to ejaculate between the spawning pair. Using field behavioural data, genetic data and new mathematical models for paternity analyses, we show, for the first time to the authors' knowledge, that sneaks fertilize more eggs than guards during sperm competition. In addition, we show that sneakers are superior to satellites in sperm competition and, thus, that even among sneaks there are tactic-specific differences in competitive success.

  4. Sperm competition in a fish with external fertilization: the contribution of sperm number, speed and length.

    PubMed

    Stoltz, J A; Neff, B D

    2006-11-01

    The role of sperm number and quality in male competitiveness was investigated using in vitro fertilization experiments with bluegill (Lepomis macrochirus). Bluegill males use one of three mating tactics: 'sneakers', which streak spawn; 'satellites', which mimic females; and 'parentals', which are territorial. The in vitro experiments mimicked natural spawning by incorporating these males' mean proximity to eggs and timing of sperm release. Using a maximum-likelihood algorithm, raffle equations were fit to paternity data, which revealed a strong effect of sperm number on male competitiveness. There was no difference in sperm flagellum length, curvilinear swim speed or path linearity among the three male mating types, and these traits did not explain any additional variation in male competitiveness. It was estimated that, given closer proximity to eggs, satellites need release only 0.34 times as many sperm as parentals to obtain equal paternity. Despite being farther from the eggs and releasing sperm about half a second after parentals, sneakers need only release 0.58 times as many sperm as parentals to obtain equal paternity. Thus, the increased competitiveness of sneakers' sperm must come from a component of sperm quality other than speed or length.

  5. Habitat selection by three littoral zone fishes: effects of predation pressure, plant density and macrophyte type

    USGS Publications Warehouse

    Chick, J.H.; McIvor, C.C.

    1997-01-01

    We conducted laboratory experiments which demonstrated that three littoral zone fishes differentially selected among three macrophytes when seeking refuge from predation. In the presence of a predator (a juvenile Micropterus salmoides), mosquitofish (Gambusia holbrooki), sailfin mollies (Poecilia latipinna). and dollar sunfish (Lepomis marginatus) displayed ferential use of four tank areas containing patches of either Hydrilla verticillata, Potamogeton illinoensis, Panicum hemitomon, or no plants. Patterns habitat selection, and the consistency of these patterns among replicates, differed among the three fishes and among three plant-density treatments - natural (each macrophyte presented at its mean field density), equal (all three macrophytes at the same density), and control (no plants). Selection for H. verticillata by mosquitofish was significant for both the equal and natural treatments, and thus was not caused by differences in plant density alone. Sailfin mollies displayed significant selection for H. verticillata only in the natural plant-density treatments. Dollar sunfish showed less consistent habitat selection than either mosquitofish or sailfin mollies. Significant habitat selection was not found in the absence of a predator, and there was no evidence for lection among the tank areas in control treatments. Patterns of habitat selection by the three fishes in our laboratory study corresponded to observed habitat use in Lake Okeechobee.

  6. Sensitivity of juvenile striped bass to chemicals used in aquaculture

    USGS Publications Warehouse

    Bills, Terry D.; Marking, Leif L.; Howe, George E.

    1993-01-01

    Efforts to restore anadromous striped bass (Morone saxatilis) populations by the U.S. Fish and Wildlife Service and other agencies over the past 20 years have concentrated on hatchery culture to supplement dwindling natural reproduction. Adult fish captured for artificial spawning are stressed by handling and crowding in rearing ponds and are often exposed to therapeutants, anesthetics, disinfectants, and herbicides used in fish culture. We determined the toxicity of 17 fishery chemicals (chloramine-T, erythromycin, formalin, Hyamine 3500, Roccal, malachite green, sulfamerazine, benzocaine, etomidate, Finquel (MS-222) , metomidate, quinaldine sulfate, chlorine, potassium permanganate, Aquazine, copper sulfate, and Rodeo) to striped bass fry (average weight = 1 g) in reconstituted water (total hardness 40 mg/L) at 12 degree C. The 96-h LC50's (concentration calculated to produce 50% mortality in a population) ranged from 0.129 mg/L for malachite green to 340 mg/L for erythromycin. We also determined the effects of selected levels of water temperature, hardness, and pH on the toxicity of chloramine-T, formalin, malachite green, and Roccal. There were no differences in toxicity for any of the chemicals at any water quality variable tested except for chloramine-T, which was about 25 times more toxic in soft, acid water than in soft, alkaline water. Our data show that the striped bass is as sensitive to fishery chemicals as rainbow trout (Oncorhynchus mykiss), but is generally less resistant than bluegill (Lepomis macrochirus) and channel catfish (Ictalurus punctatus).

  7. Light climate and dissolved organic carbon concentration influence species-specific changes in fish zooplanktivory

    USGS Publications Warehouse

    Weidel, Brian C.; Baglini, Katherine; Jones, Stuart E.; Kelly, Patrick T.; Solomon, Christopher T.; Zwart, Jacob A.

    2017-01-01

    Dissolved organic carbon (DOC) in lakes reduces light penetration and limits fish production in low nutrient lakes, reportedly via reduced primary and secondary production. Alternatively, DOC and light reductions could influence fish by altering their visual feeding. Previous studies report mixed effects of DOC on feeding rates of zooplanktivorous fish, but most investigators tested effects of a single concentration of DOC against clear-water, turbid, or algal treatments. We used a controlled laboratory study to quantify the effects of a DOC gradient (3–19 mg L−1) on average light climate and the zooplankton feeding rate of 3 common, north temperate fishes. Light availability, which was inversely related to DOC concentration, had a positive and linear effect on zooplankton consumption by juvenile largemouth bass (Micropterus salmoides) and bluegill (Lepomis macrochirus), explaining 22% and 28% of the variation in consumption, respectively. By contrast, zooplankton feeding rates by fathead minnow (Pimephales promelas) were best predicted by a nonlinear, negative influence of light (R2 = 0.13). In bluegill feeding trials we found a general trend for positive selection of larger zooplankton (Cladocera and Chaoboridae); however, the light climate did not influence the selection of prey type. Largemouth bass selected for larger-bodied zooplankton, with weak evidence that selectivity for large Cladocera changed from negative to neutral selection based on electivity values across the light gradient. Our results suggest that the effect of DOC on the light climate of lakes may directly influence fish zooplanktivory and that this influence may vary among fish species.

  8. Use of biorobotic models of highly deformable fins for studying the mechanics and control of fin forces in fishes.

    PubMed

    Tangorra, James; Phelan, Chris; Esposito, Chris; Lauder, George

    2011-07-01

    Bony fish swim with a level of agility that is unmatched in human-developed systems. This is due, in part, to the ability of the fish to carefully control hydrodynamic forces through the active modulation of the fins' kinematics and mechanical properties. To better understand how fish produce and control forces, biorobotic models of the bluegill sunfish's (Lepomis macrochirus) caudal fin and pectoral fins were developed. The designs of these systems were based on detailed analyses of the anatomy, kinematics, and hydrodynamics of the biological fins. The fin models have been used to investigate how fin kinematics and the mechanical properties of the fin-rays influence propulsive forces and to explore kinematic patterns that were inspired by biological motions but that were not explicitly performed by the fish. Results from studies conducted with the fin models indicate that subtle changes to the kinematics and mechanical properties of fin rays can significantly impact the magnitude, direction, and time course of the 3D forces used for propulsion and maneuvers. The magnitude of the force tends to scale with the fin's stiffness, but the direction of the force is not invariant, and this causes disproportional changes in the magnitude of the thrust, lift, and lateral components of force. Results from these studies shed light on the multiple strategies that are available to the fish to modulate fin forces.

  9. The effect of fin ray flexural rigidity on the propulsive forces generated by a biorobotic fish pectoral fin.

    PubMed

    Tangorra, James L; Lauder, George V; Hunter, Ian W; Mittal, Rajat; Madden, Peter G A; Bozkurttas, Meliha

    2010-12-01

    A biorobotic pectoral fin was developed and used to study how the flexural rigidities of fin rays within a highly deformable fish fin affect the fin's propulsive forces. The design of the biorobotic fin was based on a detailed analysis of the pectoral fin of the bluegill sunfish (Lepomis macrochirus). The biorobotic fin was made to execute the kinematics used by the biological fin during steady swimming, and to have structural properties that modeled those of the biological fin. This resulted in an engineered fin that had a similar interaction with the water as the biological fin and that created close approximations of the three-dimensional motions, flows, and forces produced by the sunfish during low speed, steady swimming. Experimental trials were conducted during which biorobotic fins of seven different stiffness configurations were flapped at frequencies from 0.5 to 2.0 Hz in flows with velocities that ranged from 0 to 270 mm s(-1). During these trials, thrust and lift forces were measured, kinematics were recorded in three dimensions, and digital particle image velocimetry was used to evaluate flow hydrodynamics. The results of the trials revealed that slight changes to the fin's mechanical properties or to the operating conditions can have significant impact on the direction, magnitude and time course of the propulsive forces. In general, the magnitude of the 2-D (thrust and lift) propulsive force scaled with fin ray stiffness, and increased as the fin's flapping speed increased or as the velocity of the flow decreased.

  10. Complex inter-Kingdom interactions: carnivorous plants affect growth of an aquatic vertebrate.

    PubMed

    Davenport, Jon M; Riley, Alex W

    2017-05-01

    Coexistence of organisms in nature is more likely when phenotypic similarities of individuals are reduced. Despite the lack of similarity, distantly related taxa still compete intensely for shared resources. No larger difference between organisms that share a common prey could exist than between carnivorous plants and animals. However, few studies have considered inter-Kingdom competition among carnivorous plants and animals. In order to evaluate interactions between a carnivorous plant (greater bladderwort, Utricularia vulgaris) and a vertebrate (bluegill, Lepomis macrochirus) on a shared prey (zooplankton), we conducted a mesocosm experiment. We deployed two levels of bladderwort presence (functional and crushed) and measured bluegill responses (survival and growth). Zooplankton abundance was reduced the greatest in bluegill and functional bladderwort treatments. Bluegill survival did not differ among treatments, but growth was greatest with crushed bladderwort. Thus, bluegill growth was facilitated by reducing interference competition in the presence of crushed bladderwort. The facilitating effect was dampened, however, when functional bladderwort removed a shared prey. To our knowledge, this is one of the first studies to experimentally demonstrate interactions between a carnivorous plant and a fish. Our data suggest that carnivorous plants may actively promote or reduce animal co-occurrence from some ecosystems via facilitation or competition.

  11. Bluegill growth as modified by plant density: an exploration of underlying mechanisms

    USGS Publications Warehouse

    Savino, Jacqueline F.; Marschall, Elizabeth A.; Stein, Roy A.

    1992-01-01

    Bluegill (Lepomis macrochira) growth varies inconsistently with plant density. In laboratory and field experiments, we explored mechanisms underlying bluegill growth as a function of plant and invertebrate density. In the laboratory, bluegills captured more chironomids (Chironomus riparius) than damselflies (Enallagma spp. and Ischnura spp.), but energy intake per time spent searching did not differ between damselfly and chironomid treatments. From laboratory data, we described prey encounter rates as functions of plant and invertebrate density. In Clark Lake, Ohio, we created 0.05-ha mesocosms of inshore vegetation to generate macrophyte densities of 125, 270, and 385 stems/m2 of Potamogeton and Ceratophyllum and added 46-mm bluegill (1/m2). In these mesocosms, invertebrate density increased as a function of macrophyte density. Combining this function with encounter rate functions derived from laboratory data, we predicted that bluegill growth should peak at a high macrophyte density, greater than 1000 stems/m2, even though growth should change only slightly beyond 100 stems/m2. Consistent with our predictions, bluegills did not grow differentially, nor did their use of different prey taxa differ, across macrophyte densities in the field. Bluegills preferred chironomid pupae, which were relatively few in numbers but vulnerable to predation, whereas more cryptic, chironomid larvae, which were associated with vegetation but were relatively abundant, were eaten as encountered. Bluegill avoided physid snails. Contrary to previous work, vegetation did not influence growth or diet of bluegill beyond relatively low densities owing to the interaction between capture probabilities and macroinvertebrate densities.

  12. A pilot study testing a natural and a synthetic Molluscicide for controlling invasive apple snails (Pomacea maculata)

    USGS Publications Warehouse

    Olivier, Heather M.; Jenkins, Jill A.; Berhow, Mark; Carter, Jacoby

    2016-01-01

    Pomacea maculata (formerly P. insularum), an apple snail native to South America, was discovered in Louisiana in 2008. These snails strip vegetation, reproduce at tremendous rates, and have reduced rice production and caused ecosystem changes in Asia. In this pilot study snails were exposed to two molluscicides, a tea (Camellia sinensis) seed derivative (TSD) or niclosamide monohydrate (Pestanal®, 2′,5-dichloro-4′-nitrosalicylanilide, CAS #73360-56-2). Mortality was recorded after exposure to high or low concentrations (0.03 and 0.015 g/L for TSD, 1.3 and 0.13 mg/L for niclosamide). The TSD induced 100 % mortality at both concentrations. Niclosamide caused 100 % and 17 % mortality at high and low concentrations respectively. These molluscicides were also tested on potential biocontrol agents, the red swamp crayfish (Procambarus clarkii) and redear sunfish (Lepomis microlophus). No crayfish mortalities occurred at either concentration for either chemical, but sunfish experienced 100 % mortality with TSD (0.03 g/L), and 21 % mortality with niclosamide (0.13 mg/L).

  13. Reproductive effects assessment of largemouth bass and bluegill in the Watts Bar Lake/Clinch River system

    SciTech Connect

    Niemela, S.L.; McCracken, M.K.; Ivey, L.J.; Greeley, M.S. Jr.

    1995-12-31

    Successful reproduction is key to the survival and maintenance of viable fish populations and therefore an important consideration in ecological risk assessments. In order to evaluate the reproductive health of fish in the Watts Bar Lake/Clinch River system downstream of the Department of Energy facilities in Oak Ridge, TN, largemouth bass (Micropterus salmoides) and bluegill sunfish (Lepomis macrochirus) were collected from seven sites at the beginning of the spawning period and a suite of parameters indicative of reproductive condition were measured. Measures of reproductive condition common to male and female fish included gonadal somatic index (GSI), and plasma concentrations of reproductive hormones. Gender specific analyses included a histological examination of the testes in males and a quantitative evaluation of ovarian parameters in females including determinations of fecundity, the number of vitellogenic and atretic oocytes, and the incidences of ovarian parasites. Evidence of reproductive impairment in largemouth bass at the two sites immediately adjacent to the Oak Ridge Reservation included lower GSIs and reproductive hormone levels (males and females), and reduced fecundity and an increase in the number of atretic oocytes (females). Similar trends were not observed in bluegill sunfish. These findings suggest that reproduction in a top-level predatory fish species, the largemouth bass, may be negatively affected by activities on the Oak Ridge Reservation.

  14. Multiple stressors in amphibian communities: effects of chemical contamination, bullfrogs, and fish.

    PubMed

    Boone, Michelle D; Semlitsch, Raymond D; Little, Edward E; Doyle, Meaghan C

    2007-01-01

    A leading hypothesis of amphibian population declines is that combinations of multiple stressors contribute to declines. We examined the role that chemical contamination, competition, and predation play singly and in combination in aquatic amphibian communities. We exposed larvae of American toads (Bufo americanus), southern leopard frogs (Rana sphenocephala), and spotted salamanders (Ambystoma maculatum) to overwintered bullfrog tadpoles (R. catesbeiana), bluegill sunfish (Lepomis macrochirus), the insecticide carbaryl, and ammonium nitrate fertilizer in 1000-L mesocosms. Most significantly, our study demonstrated that the presence of multiple factors reduced survival of B. americanus and A. maculatum and lengthened larval periods of R. sphenocephala. The presence of bluegill had the largest impact on the community; it eliminated B. americanus and A. maculatum and reduced the abundance of R. sphenocephala. Chemical contaminants had the second strongest effect on the community with the insecticide, reducing A. maculatum abundance by 50% and increasing the mass of anurans (frogs and toads) at metamorphosis; the fertilizer positively influenced time and mass at metamorphosis for both anurans and A. maculatum. Presence of overwintered bullfrogs reduced mass and increased time to metamorphosis of anurans. While both bluegill and overwintered bullfrog tadpoles had negative effects on the amphibian community, they performed better in the presence of one another and in contaminated habitats. Our results indicate that predicting deleterious combinations from single-factor effects may not be straightforward. Our research supports the hypothesis that combinations of factors can negatively impact some amphibian species and could contribute to population declines.

  15. Using hierarchical Bayesian multi-species mixture models to estimate tandem hoop-net based habitat associations and detection probabilities of fishes in reservoirs

    USGS Publications Warehouse

    Stewart, David R.; Long, James M.

    2015-01-01

    Species distribution models are useful tools to evaluate habitat relationships of fishes. We used hierarchical Bayesian multispecies mixture models to evaluate the relationships of both detection and abundance with habitat of reservoir fishes caught using tandem hoop nets. A total of 7,212 fish from 12 species were captured, and the majority of the catch was composed of Channel Catfish Ictalurus punctatus (46%), Bluegill Lepomis macrochirus(25%), and White Crappie Pomoxis annularis (14%). Detection estimates ranged from 8% to 69%, and modeling results suggested that fishes were primarily influenced by reservoir size and context, water clarity and temperature, and land-use types. Species were differentially abundant within and among habitat types, and some fishes were found to be more abundant in turbid, less impacted (e.g., by urbanization and agriculture) reservoirs with longer shoreline lengths; whereas, other species were found more often in clear, nutrient-rich impoundments that had generally shorter shoreline length and were surrounded by a higher percentage of agricultural land. Our results demonstrated that habitat and reservoir characteristics may differentially benefit species and assemblage structure. This study provides a useful framework for evaluating capture efficiency for not only hoop nets but other gear types used to sample fishes in reservoirs.

  16. Interactions of multiple predators with different foraging modes in an aquatic food web.

    PubMed

    Carey, Michael P; Wahl, David H

    2010-02-01

    Top predators can have different foraging modes that may alter their interactions and effects on food webs. Interactions between predators may be non-additive resulting from facilitation or interference, whereas their combined effects on a shared prey may result in emergent effects that are risk enhanced or risk reduced. To test the importance of multiple predators with different foraging modes, we examined the interaction between a cruising predator (largemouth bass, Micropterus salmoides) and an ambush predator (muskellunge, Esox masquinongy) foraging on a shared prey (bluegill sunfish, Lepomis macrochirus) with strong anti-predator defense behaviors. Additive and substitution designs were used to compare individual to combined predator treatments in experimental ponds. The multiple predator interaction facilitated growth of the cruising predator in the combined predator treatments, whereas predator species had substitutable effects on the growth of the ambush predator. The combined predator treatments created an emergent effect on the prey; however, the direction was dependent on the experimental design. The additive design found a risk-reducing effect, whereas the substitution design found a risk-enhancing effect for prey fish. Indirect effects from the predators weakly extended to lower trophic levels (i.e., zooplankton community). Our results highlight the need to consider differences in foraging mode of top predators, interactions between predators, and emergent effects on prey to understand food webs.

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

    PubMed

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

    2011-01-01

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

  18. Fish Community Responses to the Establishment of a Piscivore, Northern Pike (Esox lucius), in a Nebraska Sandhill Lake

    USGS Publications Warehouse

    DeBates, T.J.; Paukert, C.P.; Willis, D.W.

    2003-01-01

    Northern pike (Esox lucius) was first documented in West Long Lake, Nebraska, in 1998 when two pike <380 mm were collected. In 2002, a Peterson mark-recapture population estimate on northern pike revealed density and standing stock (i.e., biomass) estimates of 35.8 fish/ha (95% CI= ?? 8.8) and 22.0 kg/ha (95% CI= ?? 5.4), respectively. Consequently, West Long Lake was sampled in 2002 to compare relative abundance, size structure, and growth of bluegill (Lepomis macrochirus), largemouth bass (Micropterus salmoides), and yellow perch (Perca flavescens) prior to and after the establishment of a high-density northern pike population. Bluegill, largemouth bass, and yellow perch relative abundances were significantly lower in 2002 than 1998. Similarly, size structures of all three species were significantly different between years. Size structure declined for both bluegill and yellow perch, and increased for largemouth bass. Growth was significantly higher for bluegill, largemouth bass, and yellow perch in 2002 than 1998. While the fish community changes were expected with the establishment of northern pike, they occurred in a relatively short time period (i.e., four years).

  19. Fish lesions in the Chesapeake Bay: Pfiesteria-like dinoflagellates and other etiologies.

    PubMed

    Kane, A S; Oldach, D; Reimschuessel, R

    1998-05-01

    Ulcerative lesions and mass mortalities of Atlantic estuarine fish, particularly menhaden (Brevoortia tyrannus), have been associated with exposure to Pfiesteria-like dinoflagellates and their toxins. We collected fish from the Chicamacomico River, Maryland, and observed solitary ulcerative lesions on the majority of menhaden sampled. One striped bass (Morone saxatilis) had an area of reddening around the base of the dorsal fin. Bluegill (Lepomis machrochirus), channel catfish (Ictalurus punctatus), yellow perch (Perca flavescens), and carp (Cyprinus carpio) were externally nonremarkable. Histologically ulcerative menhaden lesions demonstrated marked chronic inflammatory infiltrate in large areas of exposed necrotic muscle. The ulcers contained granulomata with fungal hyphae in the necrotic tissue. Gram negative rod-shaped bacteria were also observed in the lesions, a common finding in ulcers of aquatic organisms. Our data suggest that typical ulcerative lesions observed on fish from areas of Pfiesteria-like dinoflagellate blooms are reflective of dermatosis, which may be related to a variety of individual or combined environmental stressors. Exposure to dinoflagellate toxin)s) potentially represents one such stressor. The role of Pfiesteria-like dinoflagellate toxin in fish primary lesion development is currently under investigation.

  20. Histopathological changes in selenium-exposed fish

    SciTech Connect

    Sorensen, E.M.; Bell, J.S.; Harlan, C.W.

    1983-06-01

    Redear sunfish (Lepomis microlophus) were collected from Martin Lake in east Texas. For at least 8 months, 1 year earlier, aqueous selenium-laden effluent from man-made sources was released into this 5,000-acre reservoir (unpublished data). Redear sunfish from a reference lake, 8 km upstream, were collected for comparison to Martin Lake fish. The hepatopancreas (i.e., liver and associated, disseminated exocrine pancrease), mesonephros (i.e., kidney), gonads, heart, spleen, stomach, and gill arches were preserved for histopathological examination using optical and/or transmission electron microscopy. Livers from Martin Lake redear sunfish (which had accumulated approximately 20 ppm selenium in the liver) showed central necrosis, reduced quantities of rough endoplasmic reticulum and glycogen particles, and increased numbers of lysosome-like structures. Kidneys showed proliferative glomerulonephritis, and exocrine pancreas showed marked hypertrophy at the optical level. Ultrastructurally, architectural disorganization, reduced rough endoplasmic reticulum, increased cisternal space, and proliferation of smooth endoplasmic reticulum were evident. The stomach, spleen, gill, heart, and gonads showed no abnormalities.

  1. Growth and mortality of larval sunfish in backwaters of the upper Mississippi River

    USGS Publications Warehouse

    Zigler, S.J.; Jennings, C.A.

    1993-01-01

    The authors estimated the growth and mortality of larval sunfish Lepomis spp. in backwater habitats of the upper Mississippi River with an otolith-based method and a length-based method. Fish were sampled with plankton nets at one station in Navigation Pools 8 and 14 in 1989 and at two stations in Pool 8 in 1990. For both methods, growth was modeled with an exponential equation, and instantaneous mortality was estimated by regressing the natural logarithm of fish catch for each 1-mm size-group against the estimated age of the group, which was derived from the growth equations. At two of the stations, the otolith-based method provided more precise estimates of sunfish growth than the length-based method. We were able to compare length-based and otolith-based estimates of sunfish mortality only at the two stations where we caught the largest numbers of sunfish. Estimates of mortality were similar for both methods in Pool 14, where catches were higher, but the length-based method gave significantly higher estimates in Pool 8, where the catches were lower. The otolith- based method required more laboratory analysis, but provided better estimates of the growth and mortality than the length-based method when catches were low. However, the length-based method was more cost- effective for estimating growth and mortality when catches were large.

  2. Stereological analyses of hepatocyte changes parallel arsenic accumulation in the livers of green sunfish

    SciTech Connect

    Sorensen, E.M.; Ramirez-Mitchell, R.; Pradzynski, A.; Bayer, T.L.; Wenz, L.L.

    1985-11-01

    Cellular changes in hepatocytes of green sunfish (Lepomis cyanellus) exposed to arsenic-contaminated or control lake water were compared with the level of arsenic in the liver. Standard stereological procedures involved conversion of two-dimensional data (i.e. fractional measurements of morphological changes) to three-dimensional data for interpretation. Both the volume and numbers of nuclei increased slightly with increasing concentration of arsenic in the liver. Significant increases (p less than 0.01) were observed in the volumes occupied by necrotic and fibrous bodies as arsenic levels in the liver increased; linear regression analysis of these data resulted in 0.9066 and 0.9359 correlation coefficients for necrotic and fibrous bodies, respectively, when volume changes were considered on a unit body weight basis. The volume occupied by necrotic areas, abnormal lysosomes, and autophagic vacuoles increased with increased arsenic concentration. The surface density of rough endoplasmic reticulum increased with increasing arsenic concentration; linear regression resulted in a correlation coefficient of 0.8367 when data were based on unit body weight.

  3. Derivation of water quality criteria of phenanthrene using interspecies correlation estimation models for aquatic life in China.

    PubMed

    Wu, Jiangyue; Liu, Zhengtao; Yan, Zhenguang; Yi, Xianliang

    2015-06-01

    Species sensitivity distribution (SSD) method has been widely used to derive water quality criteria (WQC). However, the toxicity data of some environmental pollutants are not easily accessible, especially for endangered and threatened species. Thus, it would be very desirable and economical to predict the toxicity of those species not subjected to toxicity test with the aid of a mathematical model. The interspecies correlation estimation (ICE) model (developed by the US Environmental Protection Agency (USEPA)) uses the initial toxicity estimate for one species to produce correlated toxicity values for multiple species, and it can be utilized to develop SSD and HC5 (hazardous concentration, 5th percentile). In this study, we explored the applicability of ICE to predict toxicity of phenanthrene to various species. ICE-based SSDs were generated using three surrogate species (Oncorhynchus mykiss, Lepomis macrochirus, and Daphnia magna) and compared with the metrical-based SSD. The corresponding HC5 of both models were also compared. The results showed there were no significant differences between HC5 derived from measured acute and ICE-based predicted values. The ICE model was verified as a valid approach for generating SSDs with limited toxicity data and deriving WQC for phenanthrene.

  4. Using Environmental DNA to Estimate the Distribution of an Invasive Fish Species in Ponds

    PubMed Central

    Takahara, Teruhiko; Minamoto, Toshifumi; Doi, Hideyuki

    2013-01-01

    Knowledge of the presence of an invasive species is critical to monitoring the sustainability of communities and ecosystems. Environmental DNA (eDNA), DNA fragments that are likely to be bound to organic matters in the water or in shed cells, has been used to monitor the presence of aquatic animals. Using an eDNA-based method, we estimated the presence of the invasive bluegill sunfish, Lepomis macrochirus, in 70 ponds located in seven locales on the Japanese mainland and on surrounding islands. We quantified the concentration of DNA copies in a 1 L water sample using quantitative real-time polymerase chain reaction (qPCR) with a primer/probe set. In addition, we visually observed the bluegill presence in the ponds from the shoreline. We detected bluegill eDNA in all the ponds where bluegills were observed visually and some where bluegills were not observed. Bluegills were also less prevalent on the islands than the mainland, likely owing to limited dispersal and introduction by humans. Our eDNA method simply and rapidly detects the presence of this invasive fish species with less disturbance to the environment during field surveys than traditional methods. PMID:23437177

  5. Environmental mercury concentrations in cultured low-trophic-level fish using food waste-based diets.

    PubMed

    Cheng, Zhang; Mo, Wing Yin; Man, Yu Bon; Lam, Cheung Lung; Choi, Wai Ming; Nie, Xiang Ping; Liu, Yi Hui; Wong, Ming Hung

    2015-01-01

    In this study, different types of food wastes were used as the major source of protein to replace the fish meal in fish feeds to produce quality fish (polyculture of different freshwater fish). During October 2011-April 2012, the concentrations of Hg in water, suspended particulate matter, and sediment of the three experimental fish ponds located in Sha Tau Kok Organic Farm were monitored, and the results were similar to or lower than those detected in commercial fish ponds around the Pearl River Delta (PRD) region (by comparing data of previous and present studies). Health risk assessments indicated that human consumption of grass carp (Ctenopharyngodon idellus), a herbivore which fed food waste feed pellets would be safer than other fish species: mud carp (Cirrhina molitorella), bighead carp (Hypophthalmichthys nobilis), and largemouth bass (Lepomis macrochirus). Due to the lower species diversity and substantially shorter food chains of the polyculture system consisting of only three fish species, the extent of Hg biomagnification was significantly lower than other polyculture ponds around PRD. Furthermore, the use of food waste instead of fish meal (mainly consisted of contaminated trash fish) further reduced the mercury accumulation in the cultured fish.

  6. Presence and biomagnification of organochlorine chemical residues in oxbow lakes of northeastern Louisiana

    USGS Publications Warehouse

    Niethammer, K.R.; White, D.H.; Baskett, T.S.; Sayre, M.W.

    1984-01-01

    Samples (98) of 16 spp. of animals were collected at Lake Providence, 88 samples of 15 spp. at Lake Bruin and 21 samples of 5 spp. at Lake St. John, Louisiana, between July 15 and Sept. 25, 1980. Residues of 13 organochlorine compounds were identified in these samples. Substantial concentrations of many compounds throughout the food webs of all 3 lakes showed that the lakes acted as sumps, accumulating residues from nearby agricultural land. DDT and its metabolites (DDE, TDE and DDMU [1-chloro-2,2,-bis(p-chlorophenyl)ethylene]), toxaphene and polychlorobiphenyls (PCB) were the principal organochloride residues detected. With few exceptions, biomagnification of the principal residues was clearly illustrated. Tertiary consumers such as green-backed heron (Butorides striatus), snakes, spotted gar (Lepisosteus oculatus) and largemouth bass (Micropterus salmoides) contained the highest residues. Bluegill (Lepomis macrochirus), blacktail shiner (Notropis venustus), yellow-crowned night heron (Nycticorax violaceus) and other secondary consumers contained lower levels of residues. Primary consumers, crayfish (Orconectes lancifer) and threadfin shad (Dorosoma petenense), contained relatively low residue levels of most compounds. Frogs contained lower residue levels than expected based on their position in the food web. Residue levels in immature green-backed herons and .gtoreq. 1 of the longer-lived predators, e.g., snakes, gars or largemouth bass could be monitored to evaluate levels of organochlorine chemical contaminants in aquatic habitats.

  7. Experimental Infections of Bluegill with the Trematode Ribeiroia ondatrae (Digenea: Cathaemasiidae): Histopathology and Hematological Response

    PubMed Central

    Calhoun, Dana M.; Schaffer, Paula A.; Gregory, Jacklyn R.; Hardy, Katherine M.; Johnson, Pieter T. J.

    2016-01-01

    Infections by the digenetic trematode, Ribeiroia ondatrae, cause severe limb malformations in many North American amphibians. Ribeiroia ondatrae also infects fishes as second intermediate hosts, but less is known about the pathology and immune responses initiated in infected fish, even though reports of infected fish date back to early 1900s. To this end, we experimentally exposed juvenile Bluegills Lepomis macrochirus to three doses of R. ondatrae cercariae and monitored the pathology, parasite infection success, and humoral responses over 648 h. All exposed fish became infected with metacercariae, and the average infection load increased with exposure dose. Histologically, infection was associated with acute hemorrhages in the lateral line and local dermis at 36 h, followed by progressive granulomatous inflammation that led to the destruction of encysted metacercariae. Correspondingly, over the course of 648 h we observed an 85% decline in average infection load among hosts, reflecting the host’s clearance of the parasite. Infection was not associated with changes in fish growth or survival, but did correlate with leukocytosis and neutrophilia in circulating host blood. Understanding the physiological responses of R. ondatrae in Bluegill will help to clarify the ecological effects of this parasite and provide a foundation for subsequent comparisons into its effects on behavior, individual health, and population dynamics of Bluegill. PMID:26587684

  8. Competitive interactions between invasive Nile tilapia and native fish: the potential for altered trophic exchange and modification of food webs.

    PubMed

    Martin, Charles W; Valentine, Marla M; Valentine, John F

    2010-12-21

    Recent studies have highlighted both the positive and negative impacts of species invasions. Most of these studies have been conducted on either immobile invasive plants or sessile fauna found at the base of food webs. Fewer studies have examined the impacts of vagile invasive consumers on native competitors. This is an issue of some importance given the controlling influence that consumers have on lower order plants and animals. Here, we present results of laboratory experiments designed to assess the impacts of unintended aquaculture releases of the Nile tilapia (Oreochromis niloticus), in estuaries of the Gulf of Mexico, on the functionally similar redspotted sunfish (Lepomis miniatus). Laboratory choice tests showed that tilapia prefer the same structured habitat that native sunfish prefer. In subsequent interspecific competition experiments, agonistic tilapia displaced sunfish from their preferred structured habitats. When a piscivore (largemouth bass) was present in the tank with both species, the survival of sunfish decreased. Based on these findings, if left unchecked, we predict that the proliferation of tilapia (and perhaps other aggressive aquaculture fishes) will have important detrimental effects on the structure of native food webs in shallow, structured coastal habitats. While it is likely that the impacts of higher trophic level invasive competitors will vary among species, these results show that consequences of unintended releases of invasive higher order consumers can be important.

  9. Metal levels in fish from the Savannah River: potential hazards to fish and other receptors.

    PubMed

    Burger, Joanna; Gaines, Karen F; Boring, C Shane; Stephens, Warren L; Snodgrass, Joel; Dixon, Carline; McMahon, Michael; Shukla, Sheila; Shukla, Tara; Gochfeld, Michael

    2002-05-01

    Fish are ideal indicators of heavy metal contamination in aquatic systems because they occupy different trophic levels and are different sizes and ages. In this paper, we report concentrations of arsenic, cadmium, chromium, copper, lead, manganese, strontium(88) and mercury in the muscle of 11 species of fish from the Savannah River near the Savannah River Site. We test the hypotheses that there are no locational, species, or trophic-level differences in contaminant levels. There were significant species differences for all metals; higher-trophic-level fish generally had higher levels of arsenic, chromium, and copper. There were relatively few locational differences, and where there were such differences, they were small. The relationships between body weight and contaminant levels were generally positive, except for strontium, where there was a negative correlation for bowfin (Amia cal va), bass (Micropterus salmoides), yellow perch (Perca flavescens), and shellcracker (Lepomis microlophus) and no relationship for the other species. The levels of most metals were similar to, or lower than, those for the United States generally, and the levels of metals in fish from the Savannah River do not appear to pose a health threat to the fish themselves or to higher-order consumers, based on levels known to cause effects. 2002 Elsevier Science (USA)

  10. Differential accumulation of selenium among axial muscle, reproductive and liver tissues of four warmwater fish species

    SciTech Connect

    Sager, D.R.; Cofield, C.R.

    1984-06-01

    Bluegill (Lepomis macrochirus), largemouth bass (Micropterus salmoides), white catfish (Ictalurus catus), and channel catfish (Ictalurus punctatus), collected from an electric power plant cooling reservoir and a municipal water supply reservoir near Roxboro, North Carolina, were analyzed for selenium concentrations in axial muscle, reproductive and liver tissues. Fishes from the municipal water reservoir had lower selenium concentrations (<0.2-2.1 ..mu..g/g - wet weight) than found in the cooling reservoir fishes (1.6-70.0 ..mu..g/g - wet weight) but similar distributions of concentrations among the tissues was evident. Selenium was differentially accumulated, with higher concentrations in liver tissues (0.7 - 70.0 ..mu..g/g - wet weight), followed by female productive tissues (0.7 - 25.0 ..mu..g/g - wet weight), axial muscle tissues (< 0.2 - 23.0 ..mu..g/g - wet weight) and male reproductive tissues (0.02 - 7.2 ..mu..g/g - wet weight).

  11. A Pilot Study Testing a Natural and a Synthetic Molluscicide for Controlling Invasive Apple Snails (Pomacea maculata).

    PubMed

    Olivier, Heather M; Jenkins, Jill A; Berhow, Mark; Carter, Jacoby

    2016-03-01

    Pomacea maculata (formerly P. insularum), an apple snail native to South America, was discovered in Louisiana in 2008. These snails strip vegetation, reproduce at tremendous rates, and have reduced rice production and caused ecosystem changes in Asia. In this pilot study snails were exposed to two molluscicides, a tea (Camellia sinensis) seed derivative (TSD) or niclosamide monohydrate (Pestanal(®), 2',5-dichloro-4'-nitrosalicylanilide, CAS #73360-56-2). Mortality was recorded after exposure to high or low concentrations (0.03 and 0.015 g/L for TSD, 1.3 and 0.13 mg/L for niclosamide). The TSD induced 100 % mortality at both concentrations. Niclosamide caused 100 % and 17 % mortality at high and low concentrations respectively. These molluscicides were also tested on potential biocontrol agents, the red swamp crayfish (Procambarus clarkii) and redear sunfish (Lepomis microlophus). No crayfish mortalities occurred at either concentration for either chemical, but sunfish experienced 100 % mortality with TSD (0.03 g/L), and 21 % mortality with niclosamide (0.13 mg/L).

  12. What Causes Partial F1 Hybrid Viability? Incomplete Penetrance versus Genetic Variation

    PubMed Central

    López-Fernández, Hernán; Bolnick, Daniel I.

    2007-01-01

    Background Interspecific hybrid crosses often produce offspring with reduced but non-zero survivorship. In this paper we ask why such partial inviability occurs. This partial inviability could arise from incomplete penetrance of lethal Dobzhansky-Muller incompatibilities (DMIs) shared by all members of a hybrid cross. Alternatively, siblings may differ with respect to the presence or number of DMIs, leading to genotype-dependent variation in viability and hence non-Mendelian segregation of parental alleles in surviving F1 hybrids. Methodology/Principal Findings We used amplified fragment length polymorphisms (AFLPs) to test for segregation distortion in one hybrid cross between green and longear sunfish (Lepomis cyanellus and L. megalotis). Hybrids showed partial viability, and twice as much segregation distortion (36.8%) of AFLPs as an intraspecific control cross (18.8%). Incomplete penetrance of DMIs, which should cause genotype-independent mortality, is insufficient to explain the observed segregation distortion. Conclusions/Significance We conclude that F1 hybrid sunfish are polymorphic for DMIs, either due to sex-linked DMI loci (causing Haldane's Rule), or polymorphic autosomal DMI loci. Because few AFLP markers were sex-linked (2%), the most parsimonious conclusion is that parents may have been heterozygous for loci causing hybrid inviability. PMID:18074018

  13. Acidification as environmental pollution: effects on fish-pond ecology

    SciTech Connect

    Murad, H.A.

    1987-01-01

    To establish the impact of acidity on fish production in ponds, experiments were conducted in fertilized sunfish (Lepomis spp.) ponds and fed channel catfish (Ictalurus punctatus) ponds. The alkalinity and pH of pond water were lowered by additions of H/sub 2/SO/sub 4/. Total alkalinity levels were 1, 3, 6, 8, and 20 mg/liter in sunfish ponds and 0, 5, and 20 in catfish production ponds. Water quality and phytoplankton density were monitored. The decrease in alkalinity caused changes in fish production and phytoplankton communities. Production of sunfish decreased with decreasing alkalinity below 20 mg/liter. Channel catfish yields were not affected significantly at a total alkalinity of 5 mg/liter and above (P > 0.05). No sign of fish stress of aluminum accumulation in the tissue were detected in catfish. There was no relation between alkalinity level and off-flavor in catfish. Chlorophyll a concentration increased as alkalinity and pH decreased, although total number of phytoplankters, gross photosynthesis, and turbidity decreased with decreases in total alkalinity. Phosphorus was more available at low alkalinity levels. Total hardness increased as alkalinity decreased.

  14. Seasonal and diel patterns of larval fish drift in a western South Carolina swamp

    SciTech Connect

    Kissick, L.A.; Paller, M.H.; Heuer, J.H.

    1988-01-01

    Fish larvae were collected weekly during 1986-1987 from the lower 3 km of Steel Creek (Barnwell County), a riverine swamp, to assess reproduction in this rarely studied habitat type. In 1987, larvae appeared in the following order and abundance (as a percentage of the total diural density): blackbanded darter Percina nigromaculatus (3%) and other darters Etheostoma spp. (32%); pirate perch Aphredoderus sayanus (NA); pygmy sunfish Elassoma spp. (7%); chubsuckers Erimyson spp. (13%); bluespotted sunfish Enneacanthus gloriosus (16%); bluegill Lepomis macrochirus (1%), redbreast sunfish L. auritus (<1%), brook silverside Labidesthes sicculus (6%) and ironcolor shiner Notropis chalybaeus (8%); warmouth L. gulosus (8%); spotted sunfish L. punctatus (NA). Unidentified cyprinids (2%), centrarchids (2%) and miscellaneous species (3%) were collected throughout the study period. Monthly diel collections showed that drift densities of chubsuckers, cyprinids, Etheostoma spp., bluegill and pygmy sunfish increased 41 to 160X after sundown; pirate perch and spotted sunfish were collected only at night. Swamp densities peaked during 2000-0159 h (111.5 per 100m), whereas densities in the channel that drained the swamp into the Savannah River peaked during 0200-0759 h (38.7). The later peak in the channel was attributed to larvae that had drifted from the swamp and were essentially lost from the system. 4 figs., 1 tab.

  15. Concentrations of elements in fish fillets, fish muscle plugs, and crayfish from the 2011 Missouri Department of Conservation general contaminant monitoring program

    USGS Publications Warehouse

    May, Thomas W.; Walther, Michael J.; Brumbaugh, William G.; McKee, Michael J.

    2013-01-01

    This report presents the results of a contaminant monitoring survey conducted annually by the Missouri Department of Conservation to examine the levels of selected elemental contaminants in fish fillets, fish muscle plugs, and crayfish. Fillet samples of yellow bullhead (Ameiurus natalis), golden redhorse (Moxostoma erythrurum), longear sunfish (Lepomis megalotis), and channel catfish (Ictalurus punctatus) were collected from six sites as part of the Missouri Department of Conservation’s Fish Contaminant Monitoring Program. Fish dorsal muscle plugs were collected from largemouth bass (Micropterus salmoides) at eight of the sites, and crayfish from two sites. Following preparation and analysis of the samples, highlights of the data were as follows: cadmium and lead residues were most elevated in crayfish tissue samples from the Big River at Cherokee Landing, with 1 to 8 micrograms per gram dry weight and 22 to 45 micrograms per gram dry weight, respectively. Some dorsal muscle plugs from largemouth bass collected from Clearwater Lake, Lake St. Louis, Noblett Lake, Hazel Creek Lake, and Harrison County Lake contained mercury residues (1.7 to 4.7 micrograms per gram dry weight) that exceeded the U.S. Environmental Protection Agency Water Quality Criterion of 1.5 micrograms per gram dry weight of fish tissue (equivalent to 0.30 micrograms per gram wet weight).

  16. Behavioral responses of anuran larvae to chemical cues of native and introduced predators in the Pacific Northwestern United States

    USGS Publications Warehouse

    Pearl, Christopher A.; Adams, Michael J.; Schuytema, Gerald S.; Nebeker, A.V.

    2003-01-01

    We compared behavioral responses of larvae of three Pacific Northwest anurans from different hydroperiods to water borne cues of native and introduced predators. Two native anurans (Pacific Treefrog, Pseudacris regilla, and Northern Red-Legged Frog, Rana aurora aurora) and introduced Bullfrogs (Rana catesbeiana) responded to water conditioned by native Redside Shiners (Richardsonius balteatus) by increasing refuge use. The larvae of the two native anurans differed in their response to introduced predator cues. Rana aurora aurora, which occur in temporary and permanent waters, responded to both introduced Bluegill Sunfish (Lepomis macrochirus) and introduced Crayfish (Procambarus clarkii). Pseudacris regilla, which occur primarily in temporary ponds, did not respond to water borne cues from either introduced predator. The broader responses of R. a. aurora may indicate greater behavioral plasticity or more exposure to novel predators than experienced by P. regilla. Larvae of introduced R. catesbeiana responded strongly to cues from two fish native to the Pacific northwest but did not alter behavior in response to any of five potential predators with which they coexist in their native range. Fish that occur with R. catesbeiana in their native range generally find Bullfrog larvae unpalatable. This pattern suggests that Bullfrog larvae can recognize cues of novel predators that may find them palatable, which could contribute to their success as an invasive species in the region.

  17. Environmental factors regulating the recruitment of walleye Sander vitreus and white bass Morone chrysops in irrigation reservoirs

    USGS Publications Warehouse

    DeBoer, Jason A.; Pope, Kevin L.; Koupal, Keith D.

    2013-01-01

    Understanding the environmental factors that regulate fish recruitment is essential for effective management of fisheries. Generally, first-year survival, and therefore recruitment, is inherently less consistent in systems with high intra- and interannual variability. Irrigation reservoirs display sporadic patterns of annual drawdown, which can pose a substantial challenge to recruitment of fishes. We developed species-specific models using an 18-year data set compiled from state and federal agencies to investigate variables that regulate the recruitment of walleye Sander vitreus and white bass Morone chrysops in irrigation reservoirs in south-west Nebraska, USA. The candidate model set for walleye included only abiotic variables (water-level elevation, minimum daily air temperature during winter prior to hatching, annual precipitation, spring warming rate and May reservoir discharge), and the candidate model set for white bass included primarily biotic variables (catch per unit effort (CPUE) of black crappie Pomoxis nigromaculatus, CPUE of age-0 walleye, CPUE of bluegill Lepomis macrochirus and CPUE of age-3 and older white bass), each of which had a greater relative importance than the single abiotic variable (minimum daily air temperature during winter after hatching). Our findings improve the understanding of the recruitment of fishes in irrigation reservoirs and the relative roles of abiotic and biotic factors.

  18. A minimally invasive method of piscine tissue collection and an analysis of long-term field-storage conditions for samples

    PubMed Central

    Campanella, James J; Smalley, John V

    2006-01-01

    Background The acquisition of high-quality DNA for use in phylogenetic and molecular population genetic studies is a primary concern for evolutionary and genetic researchers. Many non-destructive DNA sampling methods have been developed and are used with a variety of taxa in applications ranging from genetic stock assessment to molecular forensics. Results The authors have developed a field sampling method for obtaining high-quality DNA from sunfish (Lepomis) and other freshwater fish that employs a variation on the buccal swab method and results in the collection of DNA suitable for PCR amplification and polymorphism analysis. Additionally, since the circumstances of storage are always a concern for field biologists, the authors have tested the potential storage conditions of swabbed samples and whether those conditions affect DNA extraction and PCR amplification. It was found that samples stored at room temperature in the dark for over 200 days could still yield DNA suitable for PCR amplification and polymorphism detection. Conclusion These findings suggest that valuable molecular genetic data may be obtained from tissues that have not been treated or stored under optimal field conditions. Furthermore, it is clear that the lack of adequately low temperatures during transport and long term storage should not be a barrier to anyone wishing to engage in field-based molecular genetic research. PMID:16734898

  19. The development of a site-specific water-quality standard for copper

    SciTech Connect

    Sinclair, R.M.

    1989-01-01

    This dissertation proposes to determine, for one toxic chemical, copper, if the Federal water quality standard and the state interpretation of that standard are appropriate for the Duck River, some 50 miles south of Nashville, Tennessee. This involved conducting toxicity tests in Duck River water, and the use of the computer metal speciation program MINTEQA1 to predict instream impact. The speciation model chosen for the determination of chemical equilibria in this study was MINTEQA1. To test the validity of the MINTEQA1 speciation model, water chemistry from the Duck River was entered into the model. At the typical site pH of 7.8, 55.7% of the copper is bound as Cu(OH){sub 2}, 29.8% is bound as copper humate, and 12.7% is found as CuCO{sub 3}. Of extreme importance to the toxicity of copper in the site water is the complete absence of the most toxic species, ionic copper. The test species were the brook silversides minnow (Labidesthes sicculus), mosquitofish (Gambusia affinis), caddisfly larvae (Cheumatopsyche sp.), fathead minnow (Pimephales promelas), geniculate river snail (Lithasia geniculata), sunfish (Lepomis sp.), and the amphipod (Hyalella azeca). The test concentrations were confirmed by atomic absorption spectroscopy on selected concentrations. The caddisfly larvae was the single most tolerant species observed during this study, while the amphipod and snail were the two most sensitive species tested.

  20. Detection of genotoxic insult as DNA strand breaks in fish blood cells by agarose gel electrophoresis

    SciTech Connect

    Theodorakis, C.W. ); D'Surney, S.J. . Dept. of Biology); Shugart, L.R. . Environmental Sciences Division)

    1994-07-01

    DNA, isolated from the blood cells of bluegill sunfish (Lepomis macrochirus) exposed in the lab to bedded sediment collected from a site contaminated with genotoxic compounds (i.e., PAHs, PCBs, and heavy metals), was examined for strand breakage by agarose gel electrophoresis. Before electrophoresis the blood cells were embedded in agarose plugs and incubated with proteinase. After electrophoresis under both neutral (pH 7) or alkaline (pH 12) conditions, the median molecular length (MML) of the DNA distributed in the gel was determined. These quantitative measures were used to estimate the difference in the number of double- and single-strand breaks between DNA preparations. Both types of strand breakage were found to be greater in fish exposed to sediment contaminated with genotoxic compounds as compared to nonexposed fish. A statistically significant correlation was demonstrated between the MML value obtained by the electrophoretic assay reported here and the F value (measure of DNA double-strandedness) obtained by the alkaline unwinding assay.

  1. New species of Proterometra (Digenea: Azygiidae) and its life cycle in the Chickasawhay River, Mississippi, USA, with supplemental observations of Proterometra autraini.

    PubMed

    Womble, Matthew R; Orélis-Ribeiro, Raphael; Bullard, Stephen A

    2016-02-01

    We describe Proterometra ariasae n. sp. based upon cercariae shed from a freshwater snail, Pleurocera sp., and adults infecting the buccal cavity of longear sunfish, Lepomis megalotis, captured from the Chickasawhay River, Mississippi, USA. We also provide supplemental observations of cercarial and adult paratypes of Proterometra autraini from the Au Train River, Michigan, USA. Sequence data for the ribosomal internal transcribed spacer 2 (ITS2) from adults and cercariae of the new species were identical. Adults of the new species differ from congeners by having (i) a markedly large body, (ii) a proportionally large oral sucker, (iii) ovoid testes, (iv) a strongly muscular and laterally expanded pars prostatica, (v) a uterus that is extensively convoluted between the ovary and ventral sucker (vi) and a vitellarium as long as the caeca and extending posteriad beyond the anterior margin of the testes. Cercariae of the new species differ from those of its congeners by having (i) a tail stem that is shorter than 10mm and that lacks a medial constriction, (ii) obcordate furcae that are wider than long, (iii) mamillae distributed throughout the anterior tail stem only, and (v) a proportionally small distome that has relatively few uterine eggs and remains withdrawn in the anterior tail stem region in actively swimming cercariae. This is the first report of Proterometra from Mississippi, the second description to employ morphology and sequence data to elucidate a life cycle for Proterometra, and the third species of Proterometra from an intermediate host not assigned to Elimia.

  2. Evaluation of screening procedures for bioconcentratable organic chemicals in effluents and sediments

    SciTech Connect

    Burkhard, L.P.; Sheedy, B.R.

    1995-04-01

    Screening procedures have been developed by the US Environmental Protection Agency (EPA) to isolate and tentatively identify nonpolar organic chemicals in effluent and sediment samples with high potential to form chemical residues in aquatic organisms. The objective of this study was to determine if the sample components tentatively identified by the effluent- and sediment-screening procedures actually form chemical residues in aquatic organisms. This evaluation consisted of analyzing effluent and sediment samples from a field site with discharges from two coke-manufacturing facilities using the screening procedures. Effluent, sediment, crayfish (Decapoda), and sunfish (Lepomis sp.) samples from the field site were also prepared using conventional sample preparation procedures and analyzed for the tentatively identified chemicals (TIDs) reported by the screening procedures. Results of the screening procedures were then compared to the results of the analyses on the samples prepared using the conventional sample preparation procedures. For the effluent-screening procedure, 182 of 183 TIDs in Coke Plant 1 effluent and all of the 7 TIDs in Coke Plant 2 effluent were found in the crayfish, sunfish, and/or sediment samples downstream of the discharges. For the sediment-screening procedure, 92 of 93 TIDs and all of 47 TIDs in sediment samples from two sampling stations downstream of the discharges were found in the crayfish and/or sunfish samples.

  3. Bioaccumulation of organic and inorganic selenium in a laboratory food chain

    SciTech Connect

    Besser, J.M.; Canfield, T.J.; La Point, T.W. )

    1993-01-01

    Aquatic organisms accumulated selenium (Se) from inorganic and organic Se species via aqueous and food-chain exposure routes. The authors measured aqueous and food-chain Se bioaccumulation from selenate, selenite, and seleno-L-methionine in a laboratory food chain of algae (Chlamydomonas reinhardtii), daphnids (Daphnia magna), and fish (bluegill, Lepomis macrochirus). Selenium concentrations were monitored radiometrically with [sup 75]Se-labeled compounds. All three organisms concentrated Se more strongly from aqueous selenomethionine than from either inorganic Se species. Bioconcentration factors estimated from 1 [mu]g Se/L Se-methionine exposures were approximately 16,000 for algae, 200,000 for daphnids, and 5,000 for bluegills. Algae and daphnids concentrated Se more strongly from selenite than selenate whereas bluegills concentrated Se about equally from both inorganic species. Bioaccumulation of foodborne Se by daphnids and bluegills was similar in food chains dosed with different Se species. Daphnids and bluegills did not accumulate Se concentrations greater than those in their diet, except at very low dietary Se concentrations. Food-chain concentration factors (CFs) for daphnids decreased from near 1.0 to 0.5 with increases in algal Se concentrations, whereas CFs estimated from bluegill exposures averaged 0.5 over a range of foodborne Se concentrations. In exposures based on selenite, bluegills accumulated greater Se concentrations from food than from water.

  4. Aquatic hazard assessment of the organophosphate insecticide fonofos

    USGS Publications Warehouse

    Fairchild, James F.; Little, Edward E.; Huckins, James N.

    1992-01-01

    This study determined the acute and chronic toxicity of the organophosphate insecticide fonofos to standard freshwater aquatic organisms under laboratory conditions. Fonofos was acutely toxic to bluegill (Lepomis macrochirus), Daphnia (D. magna), and midge (Chironomous riparius) at 5.3, 2.7, and 39 μg/L, respectively. Three fonofos formulations (technical, 94.8% A.I.; 20G, field granular 20% A.I.; and 4E, field liquid 4#/gal A.I.) exhibited similar acute toxicities to bluegill. Exposure to fonofos delayed reproduction and decreased the intrinsic rate of increase of Daphnia during 21-d chronic exposure at the lowest tested concentration (0.08 μg/L). The no observable effect concentration (NOEC) for Daphnia survival was 0.42 μg/L; 0% survival occurred at the lowest observable effect concentration (LOEC) of 1.45 μg/L. The NOEC for midge emergence was 3.42 μg/L; only 34% emergence occurred at the LOEC of 8.24 μg/L. Chronic 30-d exposure of juvenile bluegills decreased growth and survival at 5.65 μg/L (LOEC), but no effects occurred at 2.33 μg/L (NOEC). The relative hazard of fonofos to aquatic life is similar to other carbamate and organophosphate corn insecticides.

  5. MOAtox: A comprehensive mode of action and acute aquatic toxicity database for predictive model development.

    PubMed

    Barron, M G; Lilavois, C R; Martin, T M

    2015-04-01

    The mode of toxic action (MOA) has been recognized as a key determinant of chemical toxicity and as an alternative to chemical class-based predictive toxicity modeling. However, the development of quantitative structure activity relationship (QSAR) and other models has been limited by the availability of comprehensive high quality MOA and toxicity databases. The current study developed a dataset of MOA assignments for 1213 chemicals that included a diversity of metals, pesticides, and other organic compounds that encompassed six broad and 31 specific MOAs. MOA assignments were made using a combination of high confidence approaches that included international consensus classifications, QSAR predictions, and weight of evidence professional judgment based on an assessment of structure and literature information. A toxicity database of 674 acute values linked to chemical MOA was developed for fish and invertebrates. Additionally, species-specific measured or high confidence estimated acute values were developed for the four aquatic species with the most reported toxicity values: rainbow trout (Oncorhynchus mykiss), fathead minnow (Pimephales promelas), bluegill (Lepomis macrochirus), and the cladoceran (Daphnia magna). Measured acute toxicity values met strict standardization and quality assurance requirements. Toxicity values for chemicals with missing species-specific data were estimated using established interspecies correlation models and procedures (Web-ICE; http://epa.gov/ceampubl/fchain/webice/), with the highest confidence values selected. The resulting dataset of MOA assignments and paired toxicity values are provided in spreadsheet format as a comprehensive standardized dataset available for predictive aquatic toxicology model development.

  6. The enigmatic ichnofossil Tisoa siphonalis and widespread authigenic seep carbonate formation during the Late Pliensbachian in southern France

    NASA Astrophysics Data System (ADS)

    van de Schootbrugge, B.; Harazim, D.; Sorichter, K.; Oschmann, W.; Fiebig, J.; Püttmann, W.; Peinl, M.; Zanella, F.; Teichert, B.; Hoffmann, J.; Stadnitskaia, A.; Rosenthal, Y.

    2010-06-01

    Tubular carbonate concretions of up to 1 m in length and perpendicular to bedding, occur abundantly in the Upper Pliensbachian (upper Amaltheus margaritatus Zone, Gibbosus Subzone) in outcrops (Fontaneilles section) in the vicinity of Rivière-sûr-Tarn, southern France. Stable isotope analyses of these concretions show negative &delta13C values that decrease from the rim to the center from -18.8‰ to -25.7‰ (V-PDB), but normal marine δ18O values (-1.8‰). Carbon isotope analyses of Late Pliensbachian bulk carbonate (matrix) samples from the Fontaneilles section show clearly decreasing C-isotope values across the A. margaritatus Zone, from +1‰ to -3‰ (V-PDB). Isotope analyses of coeval belemnite rostra do not document such a negative C-isotope trend with values remaining stable around +2‰ (V-PDB). Computer tomographic (CT) scanning of the tubular concretions show multiple canals that are lined or filled entirely with pyrite. Previously, the formation of these concretions with one, two, or more central tubes, has been ascribed to the activity of an enigmatic organism, possibly with annelid or arthropod affinities, known as Tisoa siphonalis. Our results suggest tisoan structures are abiogenic. Based on our geochemical analyses and sedimentological observations we suggest that these concretions formed as a combination of the anaerobic oxidation of methane (AOM) and sulfate reduction within the sediment. Fluids rich in methane and/or hydrocarbons likely altered local bulk rock carbon isotope records, but did not affect the global carbon cycle. Interestingly, Tisoa siphonalis has been described from many locations in the Grands Causses Basin in southern France, and from northern France and Luxemburg, always occurring at the same stratigraphic level. Upper Pliensbachian authigenic carbonates thus possibly cover an area of many thousand square kilometers. Greatly reduced sedimentation rates are needed to explain the stabilization of the sulfate

  7. The enigmatic ichnofossil Tisoa siphonalis and widespread authigenic seep carbonate formation during the Late Pliensbachian in southern France

    NASA Astrophysics Data System (ADS)

    van de Schootbrugge, B.; Harazim, D.; Sorichter, K.; Oschmann, W.; Fiebig, J.; Püttmann, W.; Peinl, M.; Zanella, F.; Teichert, B. M. A.; Hoffmann, J.; Stadnitskaia, A.; Rosenthal, Y.

    2010-10-01

    Tubular carbonate concretions of up to 1 m in length and perpendicular to bedding, occur abundantly in the Upper Pliensbachian (upper Amaltheus margaritatus Zone, Gibbosus Subzone) in outcrops (Fontaneilles section) in the vicinity of Rivière-sûr-Tarn, southern France. Stable isotope analyses of these concretions show negative δ13C values that decrease from the rim to the center from -18.8‰ to -25.7‰ (V-PDB), but normal marine δ18O values (-1.8‰). Carbon isotope analyses of Late Pliensbachian bulk carbonate (matrix) samples from the Fontaneilles section show clearly decreasing C-isotope values across the A. margaritatus Zone, from +1‰ to -3‰ (V-PDB). Isotope analyses of coeval belemnite rostra do not document such a negative C-isotope trend with values remaining stable around +2‰ (V-PDB). Computer tomographic (CT) scanning of the tubular concretions show multiple canals that are lined or filled entirely with pyrite. Previously, the formation of these concretions with one, two, or more central tubes, has been ascribed to the activity of an enigmatic organism, possibly with annelid or arthropod affinities, known asTisoa siphonalis. Our results suggest tisoan structures are abiogenic. Based on our geochemical analyses and sedimentological observations we suggest that these concretions formed as a combination of the anaerobic oxidation of methane (AOM) and sulfate reduction within the sediment. Fluids rich in methane and/or hydrocarbons likely altered local bulk rock carbon isotope records, but did not affect the global carbon cycle. Interestingly, Tisoa siphonalis has been described from many locations in the Grands Causses Basin in southern France, and from northern France and Luxemburg, always occurring at the same stratigraphic level. Upper Pliensbachian authigenic carbonates thus possibly cover an area of many thousand square kilometers. Greatly reduced sedimentation rates are needed to explain the stabilization of the sulfate-methane transition

  8. Late Pliensbachian (Early Jurassic) Cold Seep Carbonates: Methane Release Prior to the Toarcian Oceanic Anoxic Event

    NASA Astrophysics Data System (ADS)

    van de Schootbrugge, B.; Harazim, D.; Sorichter, K.; Fiebig, J.; Zanella, F.; Oschmann, W.; Rosenthal, Y.

    2008-12-01

    We present evidence for methane seepage during the Early Jurassic (~ 185 Ma) in the form of newly discovered extensive occurrences of carbonate concretions that resemble the subsurface plumbing system of better known Cenozoic to Recent examples of cold seep carbonates. Columnar carbonate concretions of up to 1 m in length that are perpendicular to bedding, occur abundantly in the Upper Pliensbachian (upper Amaltheus margaritatus Zone, gibbosus Subzone) in outcrops in the vicinity of Riviere-sur-Tarn, southern France. Stable isotope analyses of these nodules show depleted δ13C values that decrease from the rim to the center from -18.8 to -25.7‰ (V-PDB), but normal marine δ18O values (-1.8‰). Computer tomographic (CT) scanning of the columnar concretions show one or more central canals that are lined or filled entirely with pyrite and late diagenetic minerals. Septarian cracks are also filled with secondary calcite and/or siderite. Based on our preliminary geochemical and sedimentological observations we suggest that these concretions formed as a combination of the anaerobic oxidation of methane (AOM) and sulfate reduction within the sediment. Previously, these concretions with one, two or more central tubes have been ascribed to the activity of an enigmatic organism, possibly with annelid or arthropod affinities, known as Tisoa siphonalis. Our results suggest tisoan structures are abiogenic. Interestingly, Tisoa siphonalis has been described from many locations in the Grands Causses Basin in southern France, and from northern France and Luxemburg, always occurring at the same stratigraphic level. Upper Pliensbachian cold seep carbonates thus possibly cover an area of several thousand square kilometers, largely distributed across the basin centres of the NW European epicontinental seaway. Our findings may have far reaching implications for understanding the Toarcian Oceanic Anoxic Event, which is interpreted to bear the hallmarks of catastrophic methane release

  9. Mercury bioaccumulation in fish in a region affected by historic gold mining; the South Yuba River, Deer Creek, and Bear River watersheds, California, 1999

    USGS Publications Warehouse

    May, Jason T.; Hothem, Roger L.; Alpers, Charles N.; Law, Matthew A.

    2000-01-01

    Mercury that was used historically for gold recovery in mining areas of the Sierra Nevada continues to enter local and downstream water bodies, including the Sacramento Delta and the San Francisco Bay of northern California. Methylmercury is of particular concern because it is the most prevalent form of mercury in fish and is a potent neurotoxin that bioaccumulates at successive trophic levels within food webs. In April 1999, the U.S. Geological Survey, in cooperation with several other agencies the Forest Service (U.S. Department of Agriculture), the Bureau of Land Management, the U.S. Environmental Protection Agency, the California State Water Resources Control Board, and the Nevada County Resource Conservation District began a pilot investigation to characterize the occurrence and distribution of mercury in water, sediment, and biota in the South Yuba River, Deer Creek, and Bear River watersheds of California. Biological samples consisted of semi-aquatic and aquatic insects, amphibians, bird eggs, and fish. Fish were collected from 5 reservoirs and 14 stream sites during August through October 1999 to assess the distribution of mercury in these watersheds. Fish that were collected from reservoirs included top trophic level predators (black basses, Micropterus spp.) intermediate trophic level predators [sunfish (blue gill, Lepomis macrochirus; green sunfish, Lepomis cyanellus; and black crappie, Poxomis nigromaculatus)] and benthic omnivores (channel catfish, Ictularus punctatus). At stream sites, the species collected were upper trophic level salmonids (brown trout, Salmo trutta) and upper-to-intermediate trophic level salmonids (rainbow trout, Oncorhynchus mykiss). Boneless and skinless fillet portions from 161 fish were analyzed for total mercury; 131 samples were individual fish, and the remaining 30 fish were combined into 10 composite samples of three fish each of the same species and size class. Mercury concentrations in samples of black basses

  10. Mercury Contamination and Bioaccumulation Associated with Historical Gold Mining in the Bear and Yuba River Watersheds, Sierra Nevada, California

    NASA Astrophysics Data System (ADS)

    Alpers, C. N.; Hunerlach, M. P.; Hothem, R. L.; May, J. T.; Taylor, H. E.; DeWild, J. F.; Olson, M. L.; Krabbenhoft, D. P.; Marvin-DiPasquale, M.

    2001-12-01

    Extensive use of mercury in the mining and recovery of gold during the late 19th and early 20th centuries has led to widespread mercury contamination of water, sediment, and biota in the Sierra Nevada foothills of California. The watersheds of the Bear and Yuba Rivers were selected for study by the U.S. Geological Survey and other federal, state, and local agencies on the basis of (1) results of previous studies of bioaccumulation, (2) observations of visible elemental mercury at numerous mine sites and in river sediments, and (3) extensive historical mining on federal lands and adjacent private lands. Of 53 unfiltered water samples analyzed for total recoverable mercury (Hg-T), 17 samples (32 percent) had concentrations in excess of the U.S. Environmental Protection Agency (EPA) aquatic-life criterion of 50 nanograms per liter (ng/L). Water flowing from two separate tunnels in one mining district had Hg-T concentrations greater than 100,000 ng/L, exceeding the EPA drinking-water standard of 2,000 ng/L. Monthly sampling of the Bear River near its mouth revealed monomethylmercury (MeHg) concentrations in unfiltered water samples greater than 0.4 ng/L during July-August 1999 and January 2000. Game fish were collected from 5 reservoirs and 14 stream sites during 1999 to assess the distribution of mercury in the food chain and to examine the potential risk for humans and wildlife. Of 141 fish fillet samples of black basses (Micropterus spp.), sunfish (Lepomis macrochirus and Lepomis cyanellus), black crappie (Poxomis nigromaculatus), channel catfish (Ictularus punctatus), brown trout (Salmo trutta), and rainbow trout (Oncorhynchus mykiss) analyzed for Hg-T, 52 percent exceeded the EPA criterion of 0.3 parts per million (ppm), wet basis. Eighty-nine percent of the bass had Hg-T greater than 0.3 ppm total mercury. Based on these data, three counties issued a public health notification recommending limited consumption of game fish from the Bear and Yuba watersheds

  11. Injury and mortality of warmwater fishes immobilized by electrofishing

    USGS Publications Warehouse

    Dolan, C.R.; Miranda, L.E.

    2004-01-01

    Most studies of injury associated with electrofishing have focused on salmonids: few have given attention to warmwater fishes. Under controlled laboratory conditions, we treated bluegill Lepomis macrochirus, channel catfish Ictalurus punctatus, and largemouth bass Micropterus salmoides of various sizes to duty cycles ranging from 1.5% to 100%. This range of duty cycles represented continuous DC and pulsed-DC frequencies ranging from 15 to 110 Hz and pulse durations of 1 to 6 ms. At each duty cycle, fish were exposed to power densities in excess of those required to immobilize them within 3 s, and we subsequently determined the incidence of hemorrhage, spinal injury, and mortality. Incidence of hemorrhage averaged 3% (range, 0-25%), differed among species, and was not related to duty cycle or fish size. Incidence of spinal injury averaged 3% (range, 0-22%) and mortality averaged 10% (range, 0-75%); both differed among species and were related to duty cycle, fish size, and interactions among these variables. Largemouth bass was the species most vulnerable to hemorrhage, spinal injury, and mortality, channel catfish the least vulnerable; bluegills exhibited effects that were intermediate. Small centrarchids were especially susceptible to mortality. Fish tetanized by the electrical treatment were more likely to experience injury and mortality than fish that were only narcotized. However, mortality was not related to the injuries studied because hemorrhage and spinal injuries were similar in fish that survived electroshock and in those that died. We suggest that electrofishing with intermediate to high duty cycles could reduce electrofishing-induced injury and mortality to warmwater fish. Additionally, the power output and electrode system should be managed to induce narcosis and prevent tetany and to avoid the large peak powers required to immobilize small individuals.

  12. Effect of species, life stage, and water temperature on the toxicity of hydrogen peroxide to fish

    USGS Publications Warehouse

    Rach, J.J.; Schreier, T.M.; Howe, G.E.; Redman, S.D.

    1997-01-01

    Hydrogen peroxide is a drug of low regulatory priority status that is effective in treating fish and fish eggs infected by fungi. However, only limited information is available to guide fish culturists in administering hydrogen peroxide to diseased fish. Laboratory tests were conducted to determine (1) the sensitivity of brown trout Salmo trutta, lake trout Salvelinus namaycush, fathead minnow Pimephales promelas, walleye Stizostedion vitreum, channel catfish Ictalurus punctatus, and bluegill Lepomis, machrochirus to hydrogen peroxide treatments; (2) the sensitivity of various life stages of rainbow trout Oncorhynchus mykiss to hydrogen peroxide treatments; and (3) the effect of water temperature on the acute toxicity of hydrogen peroxide to three fish species. Fish were exposed to hydrogen peroxide concentrations ranging from 100 to 5,000 mu L/L (ppm) for 15-min or 45-min treatments every other day for four consecutive treatments to determine the sensitivity of various species and life stages of fish. Except for walleye, most species of fish tested (less than or equal to 2 g) tolerated hydrogen peroxide of 1,000 mu L/L or greater. Walleyes were sensitive to hydrogen peroxide concentrations as low as 100 mu L/L. A correlation was found between the toxicity of hydrogen peroxide and the life stages of rainbow trout; larger fish were more sensitive. Generally, the toxicity of hydrogen peroxide increased for all species as water temperature increased. The results of these experiments demonstrate that it is important to consider the effects of species, life stage, and water temperature when conducting hydrogen peroxide treatments.

  13. Hydrologic modification to improve habitat in riverine lakes: Management objectives, experimental approach, and initial conditions

    USGS Publications Warehouse

    Johnson, Barry L.; Barko, John W.; Gerasimov, Yuri; James, William F.; Litvinov, Alexander; Naimo, Teresa J.; Wiener, James G.; Gaugush, Robert F.; Rogala, James T.; Rogers, Sara J.; Schoettger, R.A.

    1996-01-01

    The Finger Lakes habitat-rehabilitation project is intended to improve physical and chemical conditions for fish in six connected back water lakes in Navigation Pool 5 of the upper Missouri River. The primary management objective is to improve water temperature, dissolved oxygen concentration and current velocity during winter for bluegills, Lepomis macrochirus, and black crappies, Pomoxis nigromaculatus, two of the primary sport fishes in the lakes. The lakes will be hydrologically altered by Installing culverts to Introduce controlled flows of oxygenated water into four lakes, and an existing unregulated culvert on a fifth lake will be equipped with a control gate to regulate inflow. These habitat modifications constitute a manipulative field experiment that will compare pre-project (1991 to summer 1993) and post-project (fall 1993 to 1996) conditions in the lakes, including hydrology, chemistry, rooted vegetation, and fish and macroinvertebrate communities. Initial data indicate that the Finger Lakes differ in water chemistry, hydrology, and macrophyte abundance. Macroinvertebrate communities also differed among lakes: species diversity was highest in lakes with dense aquatic macrophytes. The system seems to support a single fish community, although some species concentrated in individual lakes at different times. The introduction of similar flows into five of the lakes will probably reduce the existing physical and chemical differences among lakes. However, our ability to predict the effects of hydrologic modification on fish populations is limited by uncertainties concerning both the interactions of temperature, oxygen and current in winter and the biological responses of primary and secondary producers. Results from this study should provide guidance for similar habitat-rehabilitation projects in large rivers.

  14. Effects of pulse and press drying disturbance on benthic stream communities

    USGS Publications Warehouse

    Lynch, Dustin T.; Magoulick, Daniel D.

    2016-01-01

    Natural disturbance is an integral component of most ecosystems and occurs in 3 different forms: pulse, press, and ramp. In lotic ecosystems, seasonal drought is a major form of disturbance, particularly in intermittent headwater streams, which often are reduced to pools that serve as refuges for biota. We used simulated intermittent stream pools to compare the effects of control, pulse, and press drying on growth and survival in 3 fish species (Lepomis megalotis, Campostoma anomalum, and Etheostoma spectabile) commonly found together in drought-prone streams in the Ozark Highlands, USA. We also compared effects on benthic community structure, including periphyton and chironomid density and sediment in deep (permanently watered) and shallow (intermittently dewatered) habitat. Only one species, L. megalotis, showed a significant reduction in length and mass growth in press drying compared with control treatments. Drying and type of drying had no effect on survival of any fish species. Drying and type of drying had strong overall effects on periphyton growth in shallow habitats, where ash-free dry mass decreased and the autotrophic index (the ratio of chlorophyll a to total biomass) increased significantly in drying relative to control and in press relative to pulse treatments. Drying negatively affected sediment accumulation in shallow habitat and chironomid density in deep habitat. Drying in intermittent streams has species-dependent effects on fish growth and benthic structure, and pulse and press drying differ in their effects on periphyton in these systems. These effects may have important consequences in seasonally drying streams as anthropogenic influence on stream drying increases.

  15. Response latencies to postural disturbances in three species of teleostean fishes.

    PubMed

    Webb, Paul W

    2004-02-01

    Flow in aquatic systems is characterized by unsteadiness that creates destabilizing perturbations. Appropriate correction responses depend on response latency. The time between a disturbance induced by either removal of a flow refuge or striking various parts of the body with a narrow water jet was measured for three species, chosen as examples of modes in teleostean body/fin organization that are expected to affect stability. Creek chub Semotilus atromaculatus is representative of fusiform-bodied soft-rayed teleosts, smallmouth bass Micropterus dolomieu of fusiform-bodied spiny-rayed forms and bluegill Lepomis macrochirus of deep-bodied spiny-rayed forms. Observations were made at 23 degrees C. Loss of refuge resulted in a surge that fish corrected by starting to swim within 129+/-29 ms (mean +/- 2 S.E.M.) for chub, which was significantly shorter than minimal times of approximately 200 ms for bluegill and bass. Slips and heaves induced by water jets initially resulted in extension of the median and paired fins that would damp growth of the disturbance, but otherwise these disturbances were ignored. Yaws and pitches were more likely to cause fish to swim away from the stimulus, making corrections as they did so. There were no differences in latencies for slip, heave, yaw and pitch disturbances within each species, but latencies varied among species. For these disturbances, responses averaged 123+/-19 ms for chub, again significantly smaller than those of 201+/-24 ms for bass and 208+/-52 ms for bluegill. Values for the two centrarchids were not significantly different (P>0.08). The response latency for rolling disturbances did not differ among species but was significantly smaller than that for other disturbances, with an overall latency of 70+/-15 ms. The greater responsiveness to hydrostatic rolling instability is attributed to functions requiring an upright posture and differences among species in habitat preferences.

  16. Biomarkers of metals exposure in fish from lead-zinc mining areas of southeastern Missouri, USA.

    PubMed

    Schmitt, Christopher J; Whyte, Jeffrey J; Roberts, Aaron P; Annis, Mandy L; May, Thomas W; Tillitt, Donald E

    2007-05-01

    The potential effects of proposed lead-zinc mining in an ecologically sensitive area were assessed by studying a nearby mining district that has been exploited for about 30 y under contemporary environmental regulations and with modern technology. Blood and liver samples representing fish of three species (largescale stoneroller, Campostoma oligolepis, n=91; longear sunfish, Lepomis megalotis, n=105; and northern hog sucker, Hypentelium nigricans, n=20) from 16 sites representing a range of conditions relative to mining activities were collected. Samples were analyzed for metals (also reported in a companion paper) and for biomarkers of metals exposure [erythrocyte delta-aminolevulinic acid dehydratase (ALA-D) activity; concentrations of zinc protoporphyrin (ZPP), iron, and hemoglobin (Hb) in blood; and hepatic metallothionein (MT) gene expression and lipid peroxidation]. Blood lead concentrations were significantly higher and ALA-D activity significantly lower in all species at sites nearest to active lead-zinc mines and in a stream contaminated by historical mining than at reference or downstream sites. ALA-D activity was also negatively correlated with blood lead concentrations in all three species but not with other metals. Iron and Hb concentrations were positively correlated in all three species, but were not correlated with any other metals in blood or liver in any species. MT gene expression was positively correlated with liver zinc concentrations, but neither MT nor lipid peroxidase differences among fish grouped according to lead concentrations were statistically significant. ZPP was not detected by hematofluorometry in most fish, but fish with detectable ZPP were from sites affected by mining. Collectively, these results confirm that metals are released to streams from active lead-zinc mining sites and are accumulated by fish.

  17. Predictability of littoral-zone fish communities through ontogeny in Lake Texoma, Oklahoma-Texas, USA

    USGS Publications Warehouse

    Eggleton, M.A.; Ramirez, R.; Hargrave, C.W.; Gido, K.B.; Masoner, J.R.; Schnell, G.D.; Matthews, W.J.

    2005-01-01

    We sampled larval, juvenile and adult fishes from littoral-zone areas of a large reservoir (Lake Texoma, Oklahoma-Texas) (1) to characterize environmental factors that influenced fish community structure, (2) to examine how consistent fish-environment relationships were through ontogeny (i.e., larval vs. juvenile and adult), and (3) to measure the concordance of larval communities sampled during spring to juvenile and adult communities sampled at the same sites later in the year. Larval, juvenile and adult fish communities were dominated by Atherinidae (mainly inland silverside, Menidia beryllina) and Moronidae (mainly juvenile striped bass, Morone saxatilis) and were consistently structured along a gradient of site exposure to prevailing winds and waves. Larval, juvenile and adult communities along this gradient varied from atherinids and moronids at highly exposed sites to mostly centrarchids (primarily Lepomis and Micropterus spp.) at protected sites. Secondarily, zooplankton densities, water clarity, and land-use characteristics were related to fish community structure. Rank correlation analyses and Mantel tests indicated that the spatial consistency and predictability of fish communities was high as larval fishes sampled during spring were concordant with juvenile and adult fishes sampled at the same sites during summer and fall in terms of abundance, richness, and community structure. We propose that the high predictability and spatial consistency of littoral-zone fishes in Lake Texoma was a function of relatively simple communities (dominated by 1-2 species) that were structured by factors, such as site exposure to winds and waves, that varied little through time. ?? Springer 2005.

  18. Distribution and accumulation of rotenone in tissues of warm water fishes

    SciTech Connect

    Rach, J.J.; Gingerich, W.H.

    1986-03-01

    The tissue distribution of rotenoid residues was determined in tissues of common carp Cyprinus carpio (88.2 g), bluegills Lepomis macrochirus (47.9 g), and yellow perch Perca flavescens (67.7 g) after the fish were exposed to 50..mu..g/L of rotenone-6a/sup 14/C(15.9 x 10/sup 4/ Bq/..mu..M). Exposures were terminated 1 h after the fish were moribund and failed to respond to gentle prodding. The fish were dissected, and various tissues were oxidized to determine /sup 14/C-rotenone accumulation and distribution. Major rotenone metabolites were identified by gradient-elution high performance liquid chromatography. The exposure time required for fish to reach total incapacitation was 3 h for bluegills and yellow perch, and 11.25 h for common carp. The mean rotenoid concentrations (..mu..g/100g fish) in the whole body were 22.4 in yellow perch, 39.7 in bluegills, and 107.8 in common carp. The percentage of rotenone-derived /sup 14/C activity was higher in the carcass components than in the head or viscera; the skin and bone contained about 60% of the carcass activity. The highest relative rotenoid concentrations were found in the liver, bile, gills, brain, and heart. Percentages of total rotenoid material as parent rotenone were highest in yellow perch (70.0 in the viscera and 84.4 in the fillet), followed by those for bluegills (22.7 and 27.8) and common carp (9.7 and 48.5).

  19. Non-invasive measurement of instantaneous forces during aquatic locomotion: a case study of the bluegill sunfish pectoral fin.

    PubMed

    Peng, Jifeng; Dabiri, John O; Madden, Peter G; Lauder, George V

    2007-02-01

    Swimming and flying animals generate unsteady locomotive forces by delivering net momentum into the fluid wake. Hence, swimming and flying forces can be quantified by measuring the momentum of animal wakes. A recently developed model provides an approach to empirically deduce swimming and flying forces based on the measurement of velocity and vortex added-mass in the animal wake. The model is contingent on the identification of the vortex boundary in the wake. This paper demonstrates the application of that method to a case study quantifying the instantaneous locomotive forces generated by the pectoral fins of the bluegill sunfish (Lepomis macrochirus Rafinesque), measured using digital particle image velocimetry (DPIV). The finite-time Lyapunov exponent (FTLE) field calculated from the DPIV data was used to determine the wake vortex boundary, according to recently developed fluid dynamics theory. Momentum of the vortex wake and its added-mass were determined and the corresponding instantaneous locomotive forces were quantified at discrete time points during the fin stroke. The instantaneous forces estimated in this study agree in magnitude with the time-averaged forces quantified for the pectoral fin of the same species swimming in similar conditions and are consistent with the observed global motion of the animals. A key result of this study is its suggestion that the dynamical effect of the vortex wake on locomotion is to replace the real animal fin with an ;effective appendage', whose geometry is dictated by the FTLE field and whose interaction with the surrounding fluid is wholly dictated by inviscid concepts from potential flow theory. Benefits and limitations of this new framework for non-invasive instantaneous force measurement are discussed, and its application to comparative biomechanics and engineering studies is suggested.

  20. Diet dynamics of the juvenile piscivorous fish community in Spirit Lake, Iowa, USA, 1997-1998

    USGS Publications Warehouse

    Pelham, M.E.; Pierce, C.L.; Larscheid, J.G.

    2001-01-01

    We assessed temporal dynamics and variation among species and age-classes in the diets of age 0 and age 1 piscivorous fish species in Spirit Lake, Iowa, USA during 1997 and 1998. Species included walleye Stizostedion vitreum, yellow perch Perca flavescens, smallmouth bass Micropterus dolomieui, largemouth bass Micropterus salmoides, black crappie Pomoxis nigromaculatus and white bass Morone chrysops. Thirty taxa were identified in diets, including 12 species of fish. We found dramatic differences in diets among species, among age-classes within species and over time. Walleye, largemouth bass, smallmouth bass and white bass were piscivorous at age 0. Black crappie began piscivory at age 1. Yellow perch also began piscivory at age 1, but fish were a very small fraction of age-1 diets. The primary temporal pattern, seen in several species and age- classes, was an increase in piscivory from spring to fall. This pattern was due to the lack of small, age-0 prey fish in spring. Although some patterns were evident, the taxonomic composition of the diets of all species was highly variable over time, making generalizations difficult. A surprising result was the absence of yellow perch in the diet of age-0 walleye, despite their abundance in Spirit Lake and prominence in diets of age-1 walleye and other age 1-piscivores. Age-0 yellow perch were consistently too large to be eaten by age-0 piscivores, which preyed primarily on invertebrates and smaller fish such as johnny darters Etheostoma nigrum and age 0 bluegill Lepomis macrochirus. This finding suggests that predator-prey interactions and resulting population dynamics may be quite different in Spirit Lake than in other systems dominated by walleye and yellow perch.

  1. Visibility from Roads Predict the Distribution of Invasive Fishes in Agricultural Ponds

    PubMed Central

    Kizuka, Toshikazu; Akasaka, Munemitsu; Kadoya, Taku; Takamura, Noriko

    2014-01-01

    Propagule pressure and habitat characteristics are important factors used to predict the distribution of invasive alien species. For species exhibiting strong propagule pressure because of human-mediated introduction of species, indicators of introduction potential must represent the behavioral characteristics of humans. This study examined 64 agricultural ponds to assess the visibility of ponds from surrounding roads and its value as a surrogate of propagule pressure to explain the presence and absence of two invasive fish species. A three-dimensional viewshed analysis using a geographic information system quantified the visual exposure of respective ponds to humans. Binary classification trees were developed as a function of their visibility from roads, as well as five environmental factors: river density, connectivity with upstream dam reservoirs, pond area, chlorophyll a concentration, and pond drainage. Traditional indicators of human-mediated introduction (road density and proportion of urban land-use area) were alternatively included for comparison instead of visual exposure. The presence of Bluegill (Lepomis macrochirus) was predicted by the ponds' higher visibility from roads and pond connection with upstream dam reservoirs. Results suggest that fish stocking into ponds and their dispersal from upstream sources facilitated species establishment. Largemouth bass (Micropterus salmoides) distribution was constrained by chlorophyll a concentration, suggesting their lower adaptability to various environments than that of Bluegill. Based on misclassifications from classification trees for Bluegill, pond visual exposure to roads showed greater predictive capability than traditional indicators of human-mediated introduction. Pond visibility is an effective predictor of invasive species distribution. Its wider use might improve management and mitigate further invasion. The visual exposure of recipient ecosystems to humans is important for many invasive species that

  2. The role of hybridization in the distribution, conservation and management of aquatic species: Symposium review

    USGS Publications Warehouse

    Epifanio, John; Nielsen, Jennifer L.

    2001-01-01

    This issue of Reviews in Fish Biology and Fisheries contains six papers addressing several critical aspects of hybridization in fishes and aquatic organisms. Hybridization is a phenomenon long recognized in fishes (Hubbs, 1920, 1955; Schwarz, 1981), as well as in other plant and vertebrate taxa, despite some rather dogmatic proclamations to the contrary, e.g., comments made by David Starr Jordan at the beginning of the 20th century that the species “line” is rarely crossed in fishes (Clark Hubbs, personal communication). Since that time, interspecific genetic introgression has been well documented in many fish genera and species: Barbus (Berrebi and CattaneoBerrebi, 1993); Cyprinodon (Echelle and Connor, 1989; Dowling and DeMarais, 1993); Gambusia (Hubbs, 1959; Scribner and Avise, 1994); Esox (Wahl and Stein, 1993); Lepomis (Avise et al., 1984); Luxilus (Duvernell and Aspinwall, 1995); Morone (Harrell et al., 1993); Notropis (Dowling et al., 1989; Dowling and Hoeh, 1991); Oncorhynchus (Busack and Gall, 1981; Campton and Utter, 1985; Loudenslager et al., 1986; Leary et al., 1987; Forbes and Allendorf, 1991; Dowling and Childs, 1992); Salmo (Nyman, 1970; Wilkins et al., 1993; Giuffra et al., 1996; Hartley, 1996; Perez et al., 1999); Salvalinus (Hammar et al., 1991; Bernatchez et al., 1995; Baxter et al., 1997; Glemet et al., 1998; Wilson and Bernatchez, 1998); Sebastes (Seeb, 1988); Stizostedion (Billington et al., 1988). See also reviews in Campton (1987), Verspoor and Hammar (1991), Smith (1992), and Scribner et al. (2000). More recently, a number of investigations have documented not only first generation hybrids, but also subsequent generation introgressant hybrids (Bartley et al., 1990; Verspoor and Hammar, 1991). As a result, our views about species typology and hybrids continue to change.

  3. Biomarkers of metals exposure in fish from lead-zinc mining areas of Southeastern Missouri, USA

    USGS Publications Warehouse

    Schmitt, C.J.; Whyte, J.J.; Roberts, A.P.; Annis, M.L.; May, T.W.; Tillitt, D.E.

    2007-01-01

    The potential effects of proposed lead-zinc mining in an ecologically sensitive area were assessed by studying a nearby mining district that has been exploited for about 30 y under contemporary environmental regulations and with modern technology. Blood and liver samples representing fish of three species (largescale stoneroller, Campostoma oligolepis, n=91; longear sunfish, Lepomis megalotis, n=105; and northern hog sucker, Hypentelium nigricans, n=20) from 16 sites representing a range of conditions relative to mining activities were collected. Samples were analyzed for metals (also reported in a companion paper) and for biomarkers of metals exposure [erythrocyte ??-aminolevulinic acid dehydratase (ALA-D) activity; concentrations of zinc protoporphyrin (ZPP), iron, and hemoglobin (Hb) in blood; and hepatic metallothionein (MT) gene expression and lipid peroxidation]. Blood lead concentrations were significantly higher and ALA-D activity significantly lower in all species at sites nearest to active lead-zinc mines and in a stream contaminated by historical mining than at reference or downstream sites. ALA-D activity was also negatively correlated with blood lead concentrations in all three species but not with other metals. Iron and Hb concentrations were positively correlated in all three species, but were not correlated with any other metals in blood or liver in any species. MT gene expression was positively correlated with liver zinc concentrations, but neither MT nor lipid peroxidase differences among fish grouped according to lead concentrations were statistically significant. ZPP was not detected by hematofluorometry in most fish, but fish with detectable ZPP were from sites affected by mining. Collectively, these results confirm that metals are released to streams from active lead-zinc mining sites and are accumulated by fish. ?? 2007 Elsevier Inc. All rights reserved.

  4. Using data from an encounter sampler to model fish dispersal

    USGS Publications Warehouse

    Obaza, A.; DeAngelis, D.L.; Trexler, J.C.

    2011-01-01

    A method to estimate speed of free-ranging fishes using a passive sampling device is described and illustrated with data from the Everglades, U.S.A. Catch per unit effort (CPUE) from minnow traps embedded in drift fences was treated as an encounter rate and used to estimate speed, when combined with an independent estimate of density obtained by use of throw traps that enclose 1 m2 of marsh habitat. Underwater video was used to evaluate capture efficiency and species-specific bias of minnow traps and two sampling studies were used to estimate trap saturation and diel-movement patterns; these results were used to optimize sampling and derive correction factors to adjust species-specific encounter rates for bias and capture efficiency. Sailfin mollies Poecilia latipinna displayed a high frequency of escape from traps, whereas eastern mosquitofish Gambusia holbrooki were most likely to avoid a trap once they encountered it; dollar sunfish Lepomis marginatus were least likely to avoid the trap once they encountered it or to escape once they were captured. Length of sampling and time of day affected CPUE; fishes generally had a very low retention rate over a 24 h sample time and only the Everglades pygmy sunfish Elassoma evergladei were commonly captured at night. Dispersal speed of fishes in the Florida Everglades, U.S.A., was shown to vary seasonally and among species, ranging from 0.05 to 0.15 m s-1 for small poeciliids and fundulids to 0.1 to 1.8 m s-1 for L. marginatus. Speed was generally highest late in the wet season and lowest in the dry season, possibly tied to dispersal behaviours linked to finding and remaining in dry-season refuges. These speed estimates can be used to estimate the diffusive movement rate, which is commonly employed in spatial ecological models.

  5. Distribution and abundance of nonnative fishes in streams of the western United States

    USGS Publications Warehouse

    Schade, C.B.; Bonar, Scott A.

    2005-01-01

    This report presents data from one of the largest standardized stream surveys conducted in he western United States, which shows that one of every four individual fish in streams of 12 western states are nonnative. The states surveyed included Arizona, California, Colorado, Idaho, Montana, Nevada, North Dakota, Oregon, South Dakota, Utah, Washington, and Wyoming. The most widely distributed and abundant nonnative fishes in the western USA were brook trout Salvelinus fontinalis, brown trout Salmo trutta, rainbow trout Oncorhynchus mykiss, common carp Cyprinus carpio, smallmouth bass Micropterus dolomieu, largemouth bass M. salmoides, green sunfish Lepomis cyanellus, fathead minnow Pimephales promelas, yellow perch Percaflavescens, yellow bullhead Ameiurus natalis, cutthroat trout O. clarkii, western mosquitofish Gambusia affinis, golden shiner Notemigonus crysoleucas, channel catfish Ictalurus punctatus, and red shiner Cyprinella lutrensis. The greatest abundance and distribution of nonnative fishes was in interior states, and the most common nonnatives were introduced for angling. Nonnative fishes were widespread in pristine to highly disturbed streams influenced by all types of land use practices. We present ranges in water temperature, flow, stream order, riparian cover, human disturbance, and other environmental conditions where the 10 most common introduced species were found. Of the total western U.S. stream length bearing fish, 50.1% contained nonnative fishes while 17.9% contained physical environment that was ranked highly or moderately disturbed by humans. Introduced fishes can adversely affect stream communities, and they are much more widespread in western U.S. streams than habitat destruction. The widespread distribution and high relative abundance of nonnative fishes and their documented negative effects suggest their management and control should elicit at least as much attention as habitat preservation in the protection of native western U.S. stream

  6. Effects on aquatic and human health due to large scale bioenergy crop expansion.

    PubMed

    Love, Bradley J; Einheuser, Matthew D; Nejadhashemi, A Pouyan

    2011-08-01

    In this study, the environmental impacts of large scale bioenergy crops were evaluated using the Soil and Water Assessment Tool (SWAT). Daily pesticide concentration data for a study area consisting of four large watersheds located in Michigan (totaling 53,358 km²) was estimated over a six year period (2000-2005). Model outputs for atrazine, bromoxynil, glyphosate, metolachlor, pendimethalin, sethoxydim, triflualin, and 2,4-D model output were used to predict the possible long-term implications that large-scale bioenergy crop expansion may have on the bluegill (Lepomis macrochirus) and humans. Threshold toxicity levels were obtained for the bluegill and for human consumption for all pesticides being evaluated through an extensive literature review. Model output was compared to each toxicity level for the suggested exposure time (96-hour for bluegill and 24-hour for humans). The results suggest that traditional intensive row crops such as canola, corn and sorghum may negatively impact aquatic life, and in most cases affect the safe drinking water availability. The continuous corn rotation, the most representative rotation for current agricultural practices for a starch-based ethanol economy, delivers the highest concentrations of glyphosate to the stream. In addition, continuous canola contributed to a concentration of 1.11 ppm of trifluralin, a highly toxic herbicide, which is 8.7 times the 96-hour ecotoxicity of bluegills and 21 times the safe drinking water level. Also during the period of study, continuous corn resulted in the impairment of 541,152 km of stream. However, there is promise with second-generation lignocellulosic bioenergy crops such as switchgrass, which resulted in a 171,667 km reduction in total stream length that exceeds the human threshold criteria, as compared to the base scenario. Results of this study may be useful in determining the suitability of bioenergy crop rotations and aid in decision making regarding the adaptation of large

  7. Lethality and bioaccumulation of 4-nonylphenol in bluegill sunfish in littoral enclosures

    SciTech Connect

    Liber, K.; Gangl, J.A.; Corry, T.D.; Heinis, L.J.; Stay, F.S.

    1999-03-01

    Toxicity and bioaccumulation in bluegill sunfish (Lepomis macrochirus) of 4-nonylphenol (NP), a common precursor and degradation intermediate of certain nonionic surfactants, were evaluated in a set of 18 aquatic mesocosms (littoral enclosures) in northeastern Minnesota. Nonylphenol was applied to enclosures every 48 h over a 20-d period (11 applications) at rates of 3, 30, 100, and 300 {micro}g/L. Additional enclosures served as untreated controls. Maximum NP levels in the integrated water column 2 h after each application averaged 5 {+-} 4, 23 {+-} 11, 76 {+-} 21, and 243 {+-} 41 {micro}g/L over the 11 applications at the 3-, 30-, 100-, and 300-{micro}g/L treatments, respectively. Sixty-one percent of the NP dissipated from the water column within {approximately} 39 h of each application. Estimated survival of stocked juvenile bluegills was significantly reduced at the 300-{micro}g/L NP treatment. No significant effects were noted at the other NP treatments; however, the 100-{micro}g/L enclosure with the highest mean NP concentration (93 {+-} 39 {micro}g/L) within that treatment had four to nine times more dead bluegills and four to six times fewer bluegills captured at the end of the season than the other two 100-{micro}g/L enclosures (64 {+-} 23 and 71 {+-} 32 {micro}g/L) and the controls, suggesting increased mortality in this enclosure. Nonylphenol tissue concentrations in juvenile bluegills collected from enclosures treated with 3 and 30 {micro}g/L NP ranged from 0.01 to 2.94 {micro}g/g wet weight and showed a significant positive relationship with the average measured NP concentration in the water. The mean wet weight nonequilibrium NP bioaccumulation factor was 87 {+-} 124. There was no relationship between fish lipid content and NP tissue concentration.

  8. Relating fish health and reproductive metrics to contaminant bioaccumulation at the Tennessee Valley Authority Kingston coal ash spill site.

    PubMed

    Pracheil, Brenda M; Marshall Adams, S; Bevelhimer, Mark S; Fortner, Allison M; Greeley, Mark S; Murphy, Cheryl A; Mathews, Teresa J; Peterson, Mark J

    2016-08-01

    A 4.1 million m(3) coal ash release into the Emory and Clinch rivers in December 2008 at the Tennessee Valley Authority's Kingston Fossil Plant in east Tennessee, USA, prompted a long-term, large-scale biological monitoring effort to determine if there are chronic effects of this spill on resident biota. Because of the magnitude of the ash spill and the potential for exposure to coal ash-associated contaminants [e.g., selenium (Se), arsenic (As), and mercury (Hg)] which are bioaccumulative and may present human and ecological risks, an integrative, bioindicator approach was used. Three species of fish were monitored-bluegill (Lepomis macrochirus), redear sunfish (L. microlophus), and largemouth bass (Micropterus salmoides)-at ash-affected and reference sites annually for 5 years following the spill. On the same individual fish, contaminant burdens were measured in various tissues, blood chemistry parameters as metrics of fish health, and various condition and reproduction indices. A multivariate statistical approach was then used to evaluate relationships between contaminant bioaccumulation and fish metrics to assess the chronic, sub-lethal effects of exposure to the complex mixture of coal ash-associated contaminants at and around the ash spill site. This study suggests that while fish tissue concentrations of some ash-associated contaminants are elevated at the spill site, there was no consistent evidence of compromised fish health linked with the spill. Further, although relationships between elevated fillet burdens of ash-associated contaminants and some fish metrics were found, these relationships were not indicative of exposure to coal ash or spill sites. The present study adds to the weight of evidence from prior studies suggesting that fish populations have not incurred significant biological effects from spilled ash at this site: findings that are relevant to the current national discussions on the safe disposal of coal ash waste.

  9. Temporal changes in taxonomic and functional diversity of fish assemblages downstream from mountaintop mining

    USGS Publications Warehouse

    Hitt, Nathaniel P.; Chambers, Douglas B.

    2014-01-01

    Mountaintop mining (MTM) affects chemical, physical, and hydrological properties of receiving streams, but the long-term consequences for fish-assemblage structure and function are poorly understood. We sampled stream fish assemblages using electrofishing techniques in MTM exposure sites and reference sites within the Guyandotte River basin, USA, during 2010–2011. We calculated indices of taxonomic diversity (species richness, abundance, Shannon diversity) and functional diversity (functional richness, functional evenness, functional divergence) to compare exposure and reference assemblages between seasons (spring and autumn) and across years (1999–2011). We based temporal comparisons on 2 sites that were sampled during 1999–2001 by Stauffer and Ferreri (2002). Exposure assemblages had lower taxonomic and functional diversity than reference assemblages or simulated assemblages that accounted for random variation. Differences in taxonomic composition between reference and exposure assemblages were associated with conductivity and aqueous Se concentrations. Exposure assemblages had fewer species, lower abundances, and less biomass than reference assemblages across years and seasons. Green Sunfish (Lepomis cyanellus) and Creek Chub (Semotilus atromaculatus) became numerically dominant in exposure assemblages over time because of their persistence and losses of other taxa. In contrast, species richness increased over time in reference assemblages, a result that may indicate recovery from drought. Mean individual biomass increased as fish density decreased and most obligate invertivores were apparently extirpated at MTM exposure sites. Effects of MTM were not related to physical-habitat conditions but were associated with water-quality variables, which may limit quality and availability of benthic macroinvertebrate prey. Simulations revealed effects of MTM that could not be attributed to random variation in fish assemblage structure.

  10. Seasonality of odonate-mediated methylmercury flux from permanent and semipermanent ponds and potential risk to red-winged blackbirds (Agelaius phoeniceus).

    PubMed

    Williams, Edward B; Chumchal, Matthew M; Drenner, Ray W; Kennedy, James H

    2017-10-01

    Methylmercury (MeHg) is an aquatic contaminant that can be transferred to terrestrial predators by emergent aquatic insects such as odonates (damselflies and dragonflies). We assessed the effects of month and pond permanence on odonate-mediated MeHg flux (calculated as emergent odonate biomass × MeHg concentration) in 10 experimental ponds and the potential risk to nestling red-winged blackbirds (Agelaius phoeniceus) posed by consuming MeHg-contaminated odonates. Emergent odonates were collected weekly from permanent ponds with bluegill (Lepomis macrochirus; n = 5) and semipermanent ponds without fish (n = 5) over an 8-mo period (January-August 2015). The MeHg flux from damselflies, aeshnid dragonflies, and libellulid dragonflies began in March and peaked in April, May, and June, respectively, and then declined throughout the rest of the summer. Odonate-mediated MeHg flux from semipermanent ponds without fish was greater than that from permanent ponds with fish. Nesting of red-winged blackbirds overlapped with peak odonate emergence and odonate-mediated MeHg flux. Because their diet can be dominated by damselflies and dragonflies, we tested the hypothesis that MeHg-contaminated odonates may pose a health risk to nestling red-winged blackbirds. Concentrations of MeHg in odonates exceeded wildlife values (the minimum odonate MeHg concentrations causing physiologically significant doses in consumers) for nestlings, suggesting that MeHg-contaminated odonates can pose a health risk to nestling red-winged blackbirds. Environ Toxicol Chem 2017;36:2833-2837. © 2017 SETAC. © 2017 SETAC.

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

    PubMed

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

    2013-07-01

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

  12. Behavioral and physiological antipredator responses of the San Marcos salamander, Eurycea nana.

    PubMed

    Davis, Drew R; Gabor, Caitlin R

    2015-02-01

    Exposure to predatory stimuli typically results in the elevation of circulating glucocorticoid levels and a behavioral response of freezing or escape behavior in many prey species. Corticosterone (CORT) is the main glucocorticoid in amphibians and is known to be important in modulating many behaviors and developmental functions. The federally threatened San Marcos salamander, Eurycea nana, decreases activity in response to both native and introduced predatory fish, however, experience may further influence these interactions. To better understand the indirect effects of fish predators on this salamander, we examined both the antipredator behavior and water-borne CORT release rates in response to chemical cues (kairomones) from two fish species that varied in temporal risk of predation: (1) a low encounter frequency predator (largemouth bass, Micropterus salmoides), (2) a high encounter frequency predator (redbreast sunfish, Lepomis auritus), and (3) a blank water control. Salamanders reduced activity (antipredator response) after exposure to both predator treatments, but not to the blank water control, and the response to M. salmoides was significantly stronger than that to L. auritus. The CORT response (post-stimulus/pre-stimulus release rates) did not differ between the blank water control and L. auritus treatments, and both were significantly less than the CORT response to M. salmoides. Overall, E. nana showed a decreased antipredator response and no CORT response towards the high encounter frequency L. auritus as compared to the low encounter frequency M. salmoides. Eurycea nana may mute antipredator and CORT responses to high temporal frequency predators. There was, however, no correlation between CORT release rates and antipredator behavior, which suggests that the presence of predators may be affecting CORT response and behavior independently.

  13. Multimodal communication, mismatched messages and the effects of turbidity on the antipredator behavior of the Barton Springs salamander, Eurycea sosorum.

    PubMed

    Zabierek, Kristina C; Gabor, Caitlin R

    2016-09-01

    Prey may use multiple sensory channels to detect predators, whose cues may differ in altered sensory environments, such as turbid conditions. Depending on the environment, prey may use cues in an additive/complementary manner or in a compensatory manner. First, to determine whether the purely aquatic Barton Springs salamander, Eurycea sosorum, show an antipredator response to visual cues, we examined their activity when exposed to either visual cues of a predatory fish (Lepomis cyanellus) or a non-predatory fish (Etheostoma lepidum). Salamanders decreased activity in response to predator visual cues only. Then, we examined the antipredator response of these salamanders to all matched and mismatched combinations of chemical and visual cues of the same predatory and non-predatory fish in clear and low turbidity conditions. Salamanders decreased activity in response to predator chemical cues matched with predator visual cues or mismatched with non-predator visual cues. Salamanders also increased latency to first move to predator chemical cues mismatched with non-predator visual cues. Salamanders decreased activity and increased latency to first move more in clear as opposed to turbid conditions in all treatment combinations. Our results indicate that salamanders under all conditions and treatments preferentially rely on chemical cues to determine antipredator behavior, although visual cues are potentially utilized in conjunction for latency to first move. Our results also have potential conservation implications, as decreased antipredator behavior was seen in turbid conditions. These results reveal complexity of antipredator behavior in response to multiple cues under different environmental conditions, which is especially important when considering endangered species.

  14. Assessing variability in chemical acute toxicity of unionid mussels: Influence of intra- and interlaboratory testing, life stage, and species.

    PubMed

    Raimondo, Sandy; Lilavois, Crystal R; Lee, Larisa; Augspurger, Tom; Wang, Ning; Ingersoll, Chris G; Bauer, Candice; Hammer, Edward; Barron, Mace G

    2016-03-01

    The authors developed a toxicity database for unionid mussels to examine the extent of intra- and interlaboratory variability in acute toxicity tests with mussel larvae (glochidia) and juveniles; the extent of differential sensitivity of the 2 life stages; and the variation in sensitivity among commonly tested mussels (Lampsilis siliquoidea, Utterbackia imbecillis, and Villosa iris), commonly tested cladocerans (Daphnia magna and Ceriodaphnia dubia), and fish (Oncorhynchus mykiss, Pimephales promelas, and Lepomis macrochirus). The results of these analyses indicate that intralaboratory variability for median effect concentrations (EC50) averaged about 2-fold for both life stages, whereas interlaboratory variability averaged 3.6-fold for juvenile mussels and 6.3-fold for glochidia. The EC50s for juveniles and glochidia were within a factor of 2 of each other for 50% of paired records across chemicals, with juveniles more sensitive than glochidia by more than 2-fold for 33% of the comparisons made between life stages. There was a high concurrence of sensitivity of commonly tested L. siliquoidea, U. imbecillis, and V. iris to that of other mussels. However, this concurrence decreased as the taxonomic distance of the commonly tested cladocerans and fish to mussels increased. The compiled mussel database and determination of data variability will advance risk assessments by including more robust species sensitivity distributions, interspecies correlation estimates, and availability of taxon-specific empirically derived application factors for risk assessment. Published 2015 Wiley Periodicals Inc on behalf of SETAC. This article is a US Government work and, as such, is in the public domain in the United States of America.

  15. Frequency and Severity of Trauma in Fishes Subjected to Multiple-pass Depletion Electrofishing

    USGS Publications Warehouse

    Panek, Frank; Densmore, Christine L.

    2013-01-01

    The incidence and severity of trauma associated with multiple-pass electrofishing and the effects on short-term (30-d) survival and growth of Rainbow Trout Oncorhynchus mykiss, Brook Trout Salvelinus fontinalis, and five representative co-inhabiting nontarget or bycatch species were examined. Fish were held in four rectangular fiberglass tanks (190 × 66 cm) equipped with electrodes, a gravel–cobble stream substrate, and continuous water flow. Fish were exposed to one, two, or three electroshocks (100-V, 60-Hz pulsed DC) spaced 1 h apart or were held as a control. The heterogeneous field produced a mean (±SD) voltage gradient of 0.23 ± 0.024 V/cm (range = 0.20–0.30 V/cm) with a duty cycle of 30% and a 5-s exposure. Radiographs of 355 fish were examined for evidence of spinal injuries, and necropsies were performed on 303 fish to assess hemorrhagic trauma in soft tissue. Using linear regression, we demonstrated significant relationships between the number of electrical shocks and the frequency and severity of hemorrhagic and spinal trauma in each of the nontarget species (Potomac Sculpin Cottus girardi, Channel Catfish Ictalurus punctatus, Fathead Minnow Pimephales promelas, Green Sunfish Lepomis cyanellus, and Largemouth Bass Micropterus salmoides). Most of the injuries in these species were either minor or moderate. Rainbow Trout and Brook Trout generally sustained the highest incidence and severity of injuries, but those injuries were generally independent of the number of treatments. The 30-d postshock survival for the trout species was greater than 94%; survival for the bycatch species ranged from 80% (Fathead Minnow) to 100% (Green Sunfish and Channel Catfish). There were no significant differences in 30-d postshock condition factors despite observations of altered feeding behavior lasting several days to 1 week posttreatment in several of the study species.

  16. Trophic relations of introduced flathead catfish in an atlantic river

    USGS Publications Warehouse

    Baumann, Jessica R.; Kwak, Thomas J.

    2011-01-01

    The flathead catfish Pylodictis olivaris is a large piscivore that is native to the Mississippi and Rio Grande river drainages but that has been widely introduced across the United States. River ecologists and fisheries managers are concerned about introduced flathead catfish populations because of the negative impacts on native fish communities or imperiled species associated with direct predation and indirect competition from this apex predator. We studied the trophic relations of introduced flathead catfish in an Atlantic river to further understand the effects on native fish communities. Crayfish (Astacidea) occurred most frequently in the flathead catfish diet, while sunfish Lepomis spp. comprised the greatest percentage by weight. Neither of two sympatric imperiled fish species (the federally endangered Cape Fear shiner Notropis mekistocholas and the Carolina redhorse Moxostoma sp., a federal species of concern) was found in any diet sample. An ontogenetic shift in diet was evident when flathead catfish reached about 300 mm, and length significantly explained the variation in the percent composition by weight of sunfish and darters Etheostoma and Percina spp. Flathead catfish showed positive prey selectivity for taxa that occupied similar benthic microhabitat, highlighting the importance of opportunistic feeding and prey encounter rates. Flathead catfish displayed a highly variable diel feeding chronology during July, when they had a mean stomach fullness of 0.32%, but then showed a single midday feeding peak during August (mean fullness = 0.52%). The gastric evacuation rate increased between July (0.40/h) and August (0.59/h), as did daily ration, which more than doubled between the 2 months (3.06% versus 7.37%). Our findings increase the understanding of introduced flathead catfish trophic relations and the degree of vulnerability among prey taxa, which resource managers may consider in fisheries management and conservation of native fish populations and

  17. Droplet digital polymerase chain reaction (PCR) outperforms real-time PCR in the detection of environmental DNA from an invasive fish species.

    PubMed

    Doi, Hideyuki; Takahara, Teruhiko; Minamoto, Toshifumi; Matsuhashi, Saeko; Uchii, Kimiko; Yamanaka, Hiroki

    2015-05-05

    Environmental DNA (eDNA) has been used to investigate species distributions in aquatic ecosystems. Most of these studies use real-time polymerase chain reaction (PCR) to detect eDNA in water; however, PCR amplification is often inhibited by the presence of organic and inorganic matter. In droplet digital PCR (ddPCR), the sample is partitioned into thousands of nanoliter droplets, and PCR inhibition may be reduced by the detection of the end-point of PCR amplification in each droplet, independent of the amplification efficiency. In addition, real-time PCR reagents can affect PCR amplification and consequently alter detection rates. We compared the effectiveness of ddPCR and real-time PCR using two different PCR reagents for the detection of the eDNA from invasive bluegill sunfish, Lepomis macrochirus, in ponds. We found that ddPCR had higher detection rates of bluegill eDNA in pond water than real-time PCR with either of the PCR reagents, especially at low DNA concentrations. Limits of DNA detection, which were tested by spiking the bluegill DNA to DNA extracts from the ponds containing natural inhibitors, found that ddPCR had higher detection rate than real-time PCR. Our results suggest that ddPCR is more resistant to the presence of PCR inhibitors in field samples than real-time PCR. Thus, ddPCR outperforms real-time PCR methods for detecting eDNA to document species distributions in natural habitats, especially in habitats with high concentrations of PCR inhibitors.

  18. Effects of implanted transmitters on adult bluegills at two temperatures

    USGS Publications Warehouse

    Knights, Brent C.; Lasee, Becky A.

    1996-01-01

    Laterally compressed panfishes are small and have limited intraperitoneal space; thus, they may suffer adversely from surgically implanted transmitters even if the transmitter meets the generally recommended ratio of transmitter weight to fish weight of 2%. We studied the effects of intraperitoneal transmitters (2.81 g) on survival, growth, healing, and health of bluegills Lepomis macrochirus (mean weight 133 g) held for 8 weeks at 6 degree C and 20 degree C. Radio-tagged bluegills at 20 degree C had a mortality rate of 10% and tag loss rate of 15%. At 6 degree C, bluegills had no mortality or tag loss. Radio-tagged and reference fish fed in both 20 degree C raceways; however, a few reference fish appeared dominant at feeding time. This dominance by a few reference fish was also indicated by a large weight gain for three reference fish in each 20 degree C raceway. At 6 degree C, neither reference fish nor radio-tagged fish fed activity. Radio-tagged fish held at 20 degree C exhibited pelvic fin erosion, erythema and necrosis at the antenna exit and at suture insertions, and lost or loose sutures, effects not observed in other test fishes. Examination of fish held at 20 degree C also showed enclosure of the transmitters in a fibrous capsule and adhesion of visceral organs. Epithelialization over the incision occurred in radio-tagged bluegills at both temperatures, but there was little further healing at 6 degree C. At 20 degree C, tissue responses included chronic inflammation and dermal granulation. Radio-tagged fish did not appear to be more susceptible than reference fish to bacterial infection. Mortality, adverse morphological effects, altered behavior, and limited healing in bluegills suggest that implanted transmitters impaired their health. Thus, movement and habitat use data collected by telemetry for this species and perhaps for other panfishes should be interpreted with caution.

  19. Temperature acclimation alters oxidative capacities and composition of membrane lipids without influencing activities of enzymatic antioxidants or susceptibility to lipid peroxidation in fish muscle

    PubMed Central

    Grim, J. M.; Miles, D. R. B.; Crockett, E. L.

    2010-01-01

    Cold acclimation of ectotherms results typically in enhanced oxidative capacities and lipid remodeling, changes that should increase the risk of lipid peroxidation (LPO). It is unclear whether activities of antioxidant enzymes may respond in a manner to mitigate the increased potential for LPO. The current study addresses these questions using killifish (Fundulus heteroclitus macrolepidotus) and bluegill (Lepomis macrochirus) acclimated to 5 and 25°C for 9 days and 2 months, respectively. Because the effects of temperature acclimation on pro- and antioxidant metabolism may be confounded by variable activity levels among temperature groups, one species (killifish) was also subjected to a 9-day exercise acclimation. Oxidative capacity of glycolytic (skeletal) muscle (indicated by the activity of cytochrome c oxidase) was elevated by 1.5-fold in killifish, following cold acclimation, but was unchanged in cardiac muscle and also unaffected by exercise acclimation in either tissue. No changes in citrate synthase activity were detected in either tissue following temperature acclimation. Enzymatic antioxidants (catalase and superoxide dismutase) of either muscle type were unaltered by temperature or exercise acclimation. Mitochondria from glycolytic muscle of cold-acclimated killifish were enriched in highly oxidizable polyunsatured fatty acids (PUFA), including diacyl phospholipids (total carbons:total double bonds) 40:8 and 44:12. Increased oxidative capacity, coupled with elevated PUFA content in mitochondria from cold-acclimated animals did not, however, impact LPO susceptibility when measured with C11-BODIPY. The apparent mismatch between oxidative capacity and enzymatic antioxidants following temperature acclimation will be addressed in future studies. PMID:20086129

  20. Supraphysiological cortisol elevation alters the response of wild bluegill sunfish to subsequent stressors.

    PubMed

    McConnachie, Sarah H; O'Connor, Constance M; Gilmour, Kathleen M; Iwama, George K; Cooke, Steven J

    2012-06-01

    Wild fish are frequently exposed to multiple stressors, but the influence of previous or ongoing stress on an animal's subsequent response is poorly understood. Using wild-caught bluegill sunfish (Lepomis macrochirus) as a model, we used exogenous hormone implants to experimentally raise circulating cortisol in a group of fish for ∼10 days. We also maintained sham-treated and control groups of fish. We subjected all animals to a secondary stressor in the form of either a heat challenge or fasting challenge. We compared survival, body condition, and plasma-borne indicators of physiological status among cortisol-treated, sham-treated, and control groups following the secondary stressor. In order to compare short- and long-term effects of cortisol treatment, we initiated the secondary stressor either 4 or 30 days following initial cortisol treatment. Cortisol-treated fish succumbed to the fasting challenge sooner than sham-treated and control fish at both 4 and 30 days. Interestingly, cortisol-treated fish lost equilibrium sooner than sham-treated and control fish during the heat challenge when conducted at 30 days, but not at 4 days. These results demonstrate that multiple simultaneous stressors have cumulative effects on bluegill sunfish. Furthermore, these results demonstrate that supraphysiological cortisol doses alter the long-term responses of bluegill sunfish to additional challenges, even after apparent recovery. Such cumulative and long-term effects may be an important factor in mediating the response of wild animals to natural and anthropogenic stressors, and should be considered in ecological studies.

  1. Potential human health risk by metal(loid)s, 234,238U and 210Po due to consumption of fish from the "Luis L. Leon" Reservoir (Northern México).

    PubMed

    Luna-Porres, Mayra Y; Rodríguez-Villa, Marco A; Herrera-Peraza, Eduardo F; Renteria-Villalobos, Marusia; Montero-Cabrera, María E

    2014-06-25

    Concentrations of As, Cu, Fe, Hg, Pb and Zn and activity concentrations from 234,238U and 210Po in water, fillet, liver and gills were determined in three stocked fish species from the Luis L. Leon reservoir, located in Northern Mexico. The considered species were Lepomis cyanellus, Cyprinus carpio and Ictalurus furcatus. 238U and 234U activity concentration (AC) in fillet samples showed values of 0.007-0.014 and 0.01-0.02 Bq∙kg-1 wet weight (ww), respectively. Liver samples for L. cyanellus, C. carpio and I. furcatus present 210Po AC of 1.16-3.26, 0.70-1.13 and 0.93-1.37 Bq∙kg-1 ww. Arsenic, mercury and lead concentration intervals in fillet samples were 0.13-0.39, 0.005-0.126 and 0.009-0.08 mg∙kg-1 ww, respectively, while in gill samples they were 0.11-0.43, 0.002-0.039 and 0.02-0.26 mg∙kg-1 ww. The elemental Bioaccumulation Factor (BAF) for fish tissues with respect to their concentrations in water was determined. L. cyanellus showed the highest BAF values for As and total U, being BAFAs = 37 and 40 L∙kg-1 in fillet and gills, respectively, and BAFU total = 1.5 L∙kg-1 in fillet. I. furcatus showed the highest BAF values for Hg and Pb, being BAFHg = 40 and 13 L∙kg-1 in fillet and gills, and BAFPb = 6.5 and 22 L∙kg-1 in fillet and gills, respectively. Some metal(loid) concentrations are slightly higher than European regulations for fish fillets. The difference in concentrations of metal(loid)s in fillet among the studied species is probably due to their differences in diet and habitat.

  2. Toxicity of nitrite to fish: a review

    SciTech Connect

    Lewis, W.M. Jr.; Morris, D.P.

    1986-03-01

    Nitrite, an intermediate in the oxidation of ammonium to nitrate, changes hemoglobin to methemoglobin, which does not carry oxygen; nitrite may thus cause anoxia in fish and other aquatic organisms. The published literature on nitrite toxicity to fish, which consists of about 40 papers, shows that the ratio of the 24-h LC50 (concentration lethal to half of the test organisms in 24 h) to the 96-h LC50 has a median value of 2.0 and is fairly uniform across species; toxicity tests of differing duration can therefore be standardized to a common duration. In general, chronic effects are difficult to detect at concentrations below one-fifth of the 96-h LC50. Most fish concentrate nitrite in fresh water; chloride in the external environment offsets the toxicity of nitrite by competing with nitrite for uptake through the chloride cells of the gills. Bicarbonate also reduces the toxicity of nitrite, but it is less than 1% as effective as chloride. Calcium reduces the toxicity of nitrite, but much less than chloride; the effects of other metal cations have not been studied. Hydrogen ion concentration of the medium has not been shown to have a discrete effect on the toxicity of nitrite except at extreme concentrations uncharacteristic of the environments in which fish ordinarily live. Nitrite toxicity is exacerbated by low oxygen concentrations because nitrite reduces the oxygen-carrying capacity of the blood. Very small fish seem less sensitive to nitrite than fish of intermediate or large size. Present evidence suggests that salmonids are among the fishes most sensitive to nitrite. The least-sensitive species tested thus far are the largemouth bass Micropterus salmoides and bluegill Lepomis macrochirus; the largemouth bass does not concentrate nitrite.

  3. Northwestern salamanders Ambystoma gracile in mountain lakes: record oviposition depths among salamanders

    USGS Publications Warehouse

    Hoffman, R.; Pearl, C.A.; Larson, G.L.; Samora, B.

    2012-01-01

    Oviposition timing, behaviors, and microhabitats of ambystomatid salamanders vary considerably (Egan and Paton 2004; Figiel and Semlitsch 1995; Howard and Wallace 1985; Mac-Cracken 2007). Regardless of species, however, females typically oviposit using sites conducive to embryo development and survival. For example, the results of an experiment by Figiel and Semlitsch (1995) on Ambystoma opacum (Marbled Salamander) oviposition indicated that females actively selected sites that were under grass clumps in wet versus dry treatments, and surmised that environmental conditions such as humidity, moisture, and temperature contributed to their results. Other factors associated with ambystomatid oviposition and embryo survival include water temperature (Anderson 1972; Brown 1976), dissolved oxygen concentration (Petranka et al. 1982; Sacerdote and King 2009), oviposition depth (Dougherty et al. 2005; Egan and Paton 2004), and oviposition attachment structures such as woody vegetation (McCracken 2007; Nussbaum et al. 1983). Resetarits (1996), in creating a model of oviposition site selection for anuran amphibians, hypothesized that oviparous organisms were also capable of modifying oviposition behavior and site selection to accommodate varying habitat conditions and to minimize potential negative effects of environmental stressors. Kats and Sih (1992), investigating the oviposition of Ambystoma barbouri (Streamside Salamander) in pools of a Kentucky stream, found that females preferred pools without predatory Lepomis cyanellus (Green Sunfish), and that the number of egg masses present in a pool historically containing fish increased significantly the year after fish had been extirpated from the pool. Palen et al. (2005) determined that Ambystoma gracile (Northwestern Salamander) and Ambystoma macrodactylum (Longtoed Salamander) eggs were deposited either at increased depth or in full shaded habitats, respectively, as water transperancy to UV-B radiation increased.

  4. Impacts of golden alga Prymnesium parvum on fish populations in reservoirs of the upper Colorado River and Brazos River basins, Texas

    USGS Publications Warehouse

    VanLandeghem, Matthew M.; Farooqi, Mukhtar; Farquhar, B.; Patino, Reynaldo

    2013-01-01

    Several reservoirs in the upper Colorado River and Brazos River basins in Texas have experienced toxic blooms of golden alga Prymnesium parvum and associated fish kills since 2001. There is a paucity of information, however, regarding the population-level effects of such kills in large reservoirs, species-specific resistance to or recovery from kills, or potential differences in the patterns of impacts among basins. We used multiple before-after, control-impact analysis to determine whether repeated golden alga blooms have led to declines in the relative abundance and size structure of fish populations. Sustained declines were noted for 9 of 12 fish species surveyed in the upper Colorado River, whereas only one of eight species was impacted by golden alga in the Brazos River. In the upper Colorado River, White Bass Morone chrysops, White Crappie Pomoxis annularis, Largemouth Bass Micropterus salmoides, Bluegill Lepomis macrochirus, River Carpsucker Carpiodes carpio, Freshwater Drum Aplodinotus grunniens, Channel Catfish Ictalurus punctatus, Flathead Catfish Pylodictis olivaris, and Blue Catfish I. furcatus exhibited sustained declines in relative abundance, size structure, or both; Gizzard Shad Dorosoma cepedianum, Longnose Gar Lepisosteus osseus, and Common Carp Cyprinus carpio did not exhibit those declines. In the Brazos River, only the relative abundance of Blue Catfish was impacted. Overall, toxic golden alga blooms can negatively impact fish populations over the long-term, but the patterns of impact can vary considerably among river basins and species. In the Brazos River, populations of most fish species appear to be healthy, suggesting a positive angling outlook for this basin. In the upper Colorado River, fish populations have been severely impacted, and angling opportunities have been reduced. Basin-specific management plans aimed at improving water quality and quantity will likely reduce bloom intensity and allow recovery of fish populations to the

  5. Summary of total mercury concentrations in fillets of selected sport fishes collected during 2000-2003 from Lake Natoma, Sacramento County, California

    USGS Publications Warehouse

    Saiki, Michael K.; Slotton, Darrell G.; May, Thomas W.; Ayers, Shaun M.; Alpers, Charles N.

    2004-01-01

    This report summarizes results of total mercury measurements in skinless fillets of sport fishes collected during August 2000, September?October 2002, and July 2003 from Lake Natoma, a small (8,760 acre-feet) afterbay for Folsom Dam on the lower American River. The primary objective of the study was to determine if mercury concentrations in fillets approached or exceeded guidelines for human consumption. The Food and Drug Administration (FDA) human-health action level for methylmercury in commercially caught fish is 1.0 ?g/g (microgram per gram); the U.S. Environmental Protection Agency (USEPA) human-health criterion for methylmercury residue in fish tissue is 0.30 ?g/g. Wet weight concentrations of total mercury in skinless fillets were as high as 0.19 ?g/g in bluegill (Lepomis macrochirus), 0.39 ?g/g in redear sunfish (L. microlophus), 1.02 ?g/g in largemouth bass (Micropterus salmoides), and 1.89 ?g/g in channel catfish (Ictalurus punctatus). Maximum concentrations of mercury in other fish species varied from 0.10 ?g/g in rainbow trout (Oncorhynchus mykiss) to 0.56 ?g/g in white catfish (A-meiurus catus). Altogether, 1 of 86 largemouth bass and 11 of 11 channel catfish exceeded the FDA human-health action level. In addition, 1 of 20 redear sunfish, 26 of 86 largemouth bass, 2 of 3 spotted bass (M. punctulatus), 1 of 1 brown bullhead (A. nebulosus), and 1 of 1 white catfish exceeded the USEPA human-health criterion. These results indicate that some fish species inhabiting Lake Natoma contain undesirably high concentrations of mercury in their skinless fillets.

  6. Centrarchid assemblages in Mississippi state-operated fishing lakes

    USGS Publications Warehouse

    Olive, J.A.; Miranda, L.E.; Hubbard, W.D.

    2005-01-01

    We evaluated electrofishing catch per effort in 27 state-operated fishing lakes in Mississippi to identify patterns of centrarchid community composition and to determine whether those patterns were related to selected environmental characteristics and to artificial nutrient enrichment. Ordination with detrended correspondence analysis recognized two major axes accounting for 77% of the variability in species ordination. Axis 1 showed a distinct separation between the body sizes of various species. A notable exception was the density of small (<30 cm) largemouth bass Micropterus salmoides, which aligned with the large individuals of other centrarchid species. This pattern suggested that through predation, high densities of small largemouth bass exerted significant control over the size structure of fish communities. Axis 2 separated species of crappies Pomoxis spp., suggesting that conditions other than strong species interactions also moderated the composition of crappies in the assemblages. However, neither lake morphometry nor watershed composition exhibited a major influence over axes 1 or 2. In small, intensively managed lakes with low habitat complexity, the regulatory importance of biotic interactions may overwhelm that of abiotic factors. Nutrient enrichment influenced community structure by changing the densities of bluegill Lepomis macrochirus and largemouth bass substantially but had a minor or no effect on other species. The management techniques used in these state-operated lakes are usually targeted toward a particular species without adequately considering the other species within the community. Our results show that attention to community-level interactions could provide valuable insight into factors that affect the quality of the fishery, insight that is not available through traditional population-level assessments. ?? Copyright by the American Fisheries Society 2005.

  7. Ecological risk of methylmercury in Everglades National Park, Florida, USA.

    PubMed

    Rumbold, D G; Lange, T R; Axelrad, D M; Atkeson, T D

    2008-10-01

    Dramatic declines in mercury levels have been reported in Everglades biota in recent years. Yet, methylmercury (MeHg) hot spots remain. This paper summarizes a risk assessment of MeHg exposure to three piscivorous wildlife species (bald eagle, Haliaeetus leucocephalus; wood stork, Mycteria americana; and great egret, Ardea albus) foraging at a MeHg hot spot in northern Everglades National Park (ENP). Available data consisted of literature-derived life history parameters and tissue concentrations measured in 60 largemouth bass (Micropterus salmoides), 60 sunfish (Lepomis spp.), and three composite samples of mosquitofish (Gambusia holbrooki) collected from 2003 to 2005. To assess risk, daily MeHg intake was estimated using Monte Carlo methods and compared to literature-derived effects thresholds. The results indicated the likelihood was very high, ranging from 98-100% probability, that these birds would experience exposures above the acceptable dose when foraging in northern ENP. Moreover, the likelihood that these birds would experience exposures above the lowest-observed-adverse-effect level (LOAEL) ranged from a 14% probability for the wood stork to 56% probability for the eagle. Data from this study, along with the results from several other surveys suggest that biota in ENP currently contain the highest MeHg levels in South Florida and that these levels are similar to or greater than other known MeHg hot spots in the United States. Given these findings, this paper also outlines a strategic plan to obtain additional measured and modeled information to support risk-based management decisions in ENP.

  8. Piscivory in juvenile walleyes: Relative importance of prey species, timing of spawning of prey fish, and density on growth and survival

    USGS Publications Warehouse

    Kolar, C.S.; Wahl, David H.; Hooe, M.L.

    2003-01-01

    We examined the effect of the timing of spawning by prey fish and the species of prey fish on the growth and survival of juvenile walleye Stizostedion vitreum. We expected that age-0 walleyes would grow more in ponds when stocked about the same time as the spawning of gizzard shad Dorosoma cepedianum than when stocked about 6 weeks after spawning. We found, however, that the timing of larval gizzard shad presence did not affect walleye growth or survival. Also contrary to our expectations, walleyes from ponds with bluegill Lepomis macrochirus grew more (by 9% in total length and 38% in mass) than those from ponds with gizzard shad. However, the density of gizzard shad was lower than that of bluegills, particularly after the first few weeks of the experiment. Bluegills remained within the gape limits of walleyes throughout the experiment, whereas gizzard shad outgrew their vulnerability to predation. Late-spawned gizzard shad remained vulnerable to walleye predation only slightly longer than did those from early spawned ponds. The survival of age-0 walleyes was unaffected by water temperature, the timing of spawning by prey fish, prey species, or density. Our results suggest that even though walleyes typically grow faster in systems with gizzard shad as prey than in those with bluegills, juvenile walleyes can still grow well in bluegill-dominated systems. In some systems, high densities of a less beneficial prey (e.g., abundant bluegills rather than less abundant gizzard shad) may overcome the growth differences of juvenile walleyes that would be expected based on the differences in prey species alone. A wide variation in individual walleye growth in our ponds, even within prey treatments, indicated the complexity of interactions among the factors affecting juvenile walleye growth.

  9. Acute toxicity of an acid mine drainage mixing zone to juvenile bluegill and largemouth bass

    USGS Publications Warehouse

    Henry, T.B.; Irwin, E.R.; Grizzle, J.M.; Wildhaber, M.L.; Brumbaugh, W.G.

    1999-01-01

    The toxicity of an acid mixing zone produced at the confluence of a stream that was contaminated by acid mine drainage (AMD) and a pH-neutral stream was investigated in toxicity tests with juvenile bluegill Lepomis macrochirus and largemouth bass Micropterus salmoides. Fish mortalities in instream cages located in the mixing zone, below the mixing zone, and upstream in both tributaries were compared to determine relative toxicity at each site. In all tests and for both species, significantly higher mortality was observed in the mixing zone than at any other location, including the acid stream, which had lower pH (2.9-4.3). The mixing zone was defined chemically by rapid precipitation of dissolved aluminum and iron, which arrived from the low-pH stream, and by the presence of white precipitates, which were attached to the substratum and which extended below the confluence. Possible seasonal changes in mixing zone toxicity were investigated by conducting field tests with bluegill in June, July, and August 1996 and in January 1997 and by conducting field tests with largemouth bass in April and May 1997. Toxicity was not significantly different at the extremes of temperature, pH, and metal concentration that occurred in June and July, as compared with January. Toxicity was significantly lower in August; however, elevated stream discharge during the August test may have disturbed mixing zone characteristics. High toxicity in AMD mixing zones may lower the survival of fishes in streams, reduce available habitat, and impede movements of migratory fish.

  10. Contaminants of emerging concern in tributaries to the Laurentian Great Lakes: II. Biological consequences of exposure

    PubMed Central

    Brigham, Mark E.; Choy, Steven J.; Moore, Jeremy N.; Banda, Jo A.; Gefell, Daniel J.; Minarik, Thomas A.

    2017-01-01

    The Laurentian Great Lakes contain one fifth of the world’s surface freshwater and have been impacted by human activity since the Industrial Revolution. In addition to legacy contaminants, nitrification and invasive species, this aquatic ecosystem is also the recipient of Contaminants of Emerging Concern (CECs) with poorly understood biological consequences. In the current study, we documented the presence, concentrations, and biological effects of CECs across 27 field sites in six Great Lakes tributaries by examining over 2250 resident and caged sunfish (Lepomis ssp.) for a variety of morphological and physiological endpoints and related these results to CEC occurrence. CEC were ubiquitous across studies sites and their presence and concentrations in water and sediment were highest in effluent dominated rivers and downstream of municipal wastewater treatment plant discharges. However, even putative upstream reference sites were not free of CEC presence and fish at these sites exhibited biological effects consistent with CEC exposure. Only the Fox River exhibited consistent adverse biological effects, including increased relative liver size, greater prominence of hepatocyte vacuoles and increased plasma glucose concentrations. Canonical Redundancy Analysis revealed consistent patterns of biological consequences of CEC exposure across all six tributaries. Increasing plasma glucose concentrations, likely as a result of pollutant-induced metabolic stress, were associated with increased relative liver size and greater prominence of hepatocyte vacuoles. These indicators of pollutant exposure were inversely correlated with indicators of reproductive potential including smaller gonad size and less mature gametes. The current study highlights the need for greater integration of chemical and biological studies and suggests that CECs in the Laurentian Great Lakes Basin may adversely affect the reproductive potential of exposed fish populations. PMID:28953953

  11. Hydrodynamics of a robotic fish tail: effects of the caudal peduncle, fin ray motions and the flow speed.

    PubMed

    Ren, Ziyu; Yang, Xingbang; Wang, Tianmiao; Wen, Li

    2016-02-08

    Recent advances in understanding fish locomotion with robotic devices have included the use of biomimetic flapping based and fin undulatory locomotion based robots, treating two locomotions separately from each other. However, in most fish species, patterns of active movements of fins occur in concert with the body undulatory deformation during swimming. In this paper, we describe a biomimetic robotic caudal fin programmed with individually actuated fin rays to mimic the fin motion of the Bluegill Sunfish (Lepomis macrochirus) and coupled with heave and pitch oscillatory motions adding to the robot to mimic the peduncle motion which is derived from the undulatory fish body. Multiple-axis force and digital particle image velocimetry (DPIV) experiments from both the vertical and horizontal planes behind the robotic model were conducted under different motion programs and flow speeds. We found that both mean thrust and lift could be altered by changing the phase difference (φ) from 0° to 360° between the robotic caudal peduncle and the fin ray motion (spanning from 3 mN to 124 mN). Notably, DPIV results demonstrated that the caudal fin generated multiple wake flow patterns in both the vertical and horizontal planes by varying φ. Vortex jet angle and thrust impulse also varied significantly both in these two planes. In addition, the vortex shedding position along the spanwise tail direction could be shifted around the mid-sagittal position between the upper and lower lobes by changing the phase difference. We hypothesize that the fish caudal fin may serve as a flexible vectoring propeller during swimming and may be critical for the high maneuverability of fish.

  12. Self-imposed length limits in recreational fisheries

    USGS Publications Warehouse

    Chizinski, Christopher J.; Martin, Dustin R.; Hurley, Keith L.; Pope, Kevin L.

    2014-01-01

    A primary motivating factor on the decision to harvest a fish among consumptive-orientated anglers is the size of the fish. There is likely a cost-benefit trade-off for harvest of individual fish that is size and species dependent, which should produce a logistic-type response of fish fate (release or harvest) as a function of fish size and species. We define the self-imposed length limit as the length at which a captured fish had a 50% probability of being harvested, which was selected because it marks the length of the fish where the probability of harvest becomes greater than the probability of release. We assessed the influences of fish size, catch per unit effort, size distribution of caught fish, and creel limit on the self-imposed length limits for bluegill Lepomis macrochirus, channel catfish Ictalurus punctatus, black crappie Pomoxis nigromaculatus and white crappie Pomoxis annularis combined, white bass Morone chrysops, and yellow perch Perca flavescens at six lakes in Nebraska, USA. As we predicted, the probability of harvest increased with increasing size for all species harvested, which supported the concept of a size-dependent trade-off in costs and benefits of harvesting individual fish. It was also clear that probability of harvest was not simply defined by fish length, but rather was likely influenced to various degrees by interactions between species, catch rate, size distribution, creel-limit regulation and fish size. A greater understanding of harvest decisions within the context of perceived likelihood that a creel limit will be realized by a given angler party, which is a function of fish availability, harvest regulation and angler skill and orientation, is needed to predict the influence that anglers have on fish communities and to allow managers to sustainable manage exploited fish populations in recreational fisheries.

  13. Visibility from roads predict the distribution of invasive fishes in agricultural ponds.

    PubMed

    Kizuka, Toshikazu; Akasaka, Munemitsu; Kadoya, Taku; Takamura, Noriko

    2014-01-01

    Propagule pressure and habitat characteristics are important factors used to predict the distribution of invasive alien species. For species exhibiting strong propagule pressure because of human-mediated introduction of species, indicators of introduction potential must represent the behavioral characteristics of humans. This study examined 64 agricultural ponds to assess the visibility of ponds from surrounding roads and its value as a surrogate of propagule pressure to explain the presence and absence of two invasive fish species. A three-dimensional viewshed analysis using a geographic information system quantified the visual exposure of respective ponds to humans. Binary classification trees were developed as a function of their visibility from roads, as well as five environmental factors: river density, connectivity with upstream dam reservoirs, pond area, chlorophyll a concentration, and pond drainage. Traditional indicators of human-mediated introduction (road density and proportion of urban land-use area) were alternatively included for comparison instead of visual exposure. The presence of Bluegill (Lepomis macrochirus) was predicted by the ponds' higher visibility from roads and pond connection with upstream dam reservoirs. Results suggest that fish stocking into ponds and their dispersal from upstream sources facilitated species establishment. Largemouth bass (Micropterus salmoides) distribution was constrained by chlorophyll a concentration, suggesting their lower adaptability to various environments than that of Bluegill. Based on misclassifications from classification trees for Bluegill, pond visual exposure to roads showed greater predictive capability than traditional indicators of human-mediated introduction. Pond visibility is an effective predictor of invasive species distribution. Its wider use might improve management and mitigate further invasion. The visual exposure of recipient ecosystems to humans is important for many invasive species that

  14. Contaminants of emerging concern in tributaries to the Laurentian Great Lakes: II. Biological consequences of exposure.

    PubMed

    Thomas, Linnea M; Jorgenson, Zachary G; Brigham, Mark E; Choy, Steven J; Moore, Jeremy N; Banda, Jo A; Gefell, Daniel J; Minarik, Thomas A; Schoenfuss, Heiko L

    2017-01-01

    The Laurentian Great Lakes contain one fifth of the world's surface freshwater and have been impacted by human activity since the Industrial Revolution. In addition to legacy contaminants, nitrification and invasive species, this aquatic ecosystem is also the recipient of Contaminants of Emerging Concern (CECs) with poorly understood biological consequences. In the current study, we documented the presence, concentrations, and biological effects of CECs across 27 field sites in six Great Lakes tributaries by examining over 2250 resident and caged sunfish (Lepomis ssp.) for a variety of morphological and physiological endpoints and related these results to CEC occurrence. CEC were ubiquitous across studies sites and their presence and concentrations in water and sediment were highest in effluent dominated rivers and downstream of municipal wastewater treatment plant discharges. However, even putative upstream reference sites were not free of CEC presence and fish at these sites exhibited biological effects consistent with CEC exposure. Only the Fox River exhibited consistent adverse biological effects, including increased relative liver size, greater prominence of hepatocyte vacuoles and increased plasma glucose concentrations. Canonical Redundancy Analysis revealed consistent patterns of biological consequences of CEC exposure across all six tributaries. Increasing plasma glucose concentrations, likely as a result of pollutant-induced metabolic stress, were associated with increased relative liver size and greater prominence of hepatocyte vacuoles. These indicators of pollutant exposure were inversely correlated with indicators of reproductive potential including smaller gonad size and less mature gametes. The current study highlights the need for greater integration of chemical and biological studies and suggests that CECs in the Laurentian Great Lakes Basin may adversely affect the reproductive potential of exposed fish populations.

  15. Metallothionein and bioaccumulation of cadmium in juvenile bluegills exposed to aqueous and sediment-associated cadmium

    SciTech Connect

    Cope, W.G.

    1991-01-01

    The author evaluated metallothionein (MT), free (unbound) hepatic cadmium and whole body cadmium as indicators of cadmium exposure in juvenile bluegills Lepomis macrochirus in laboratory tests. Two types of cadmium exposure were tested; aqueous and sediment-associated. In the aqueous tests, fish were exposed to cadmium (0.0 to 32.3 [mu]g/L) in an intermittent-flow diluter. In the sediment-associated cadmium test, fish were exposed to resuspended river sidment containing 1.3 to 21.4 [mu]g Cd/g (dry weight) at a nominal total suspended solids concentration of 1,000 mg/L in revolving, circular glass exposure chambers. Total cadmium concentrations were measured in various bluegill liver fractions, whole bluegill, water, and resuspended sediment to assess the partitioning and bioaccumulation of cadmium after the tests. Mean concentrations of MT and free cadmium in bluegill livers and concentrations of cadmium in whole bluegills were positively correlated with aqueous cadmium concentration and were equally suitable as indicators of aqueous cadmium exposure. Sediment-associated cadmium was biologically available, but to a lesser extent than aqueous cadmium. Cadmium concentrations in whole bluegills exposed to resuspended river sediment were 1.5- to 3.5-fold the concentrations in bluegills in sediment-free controls. Free cadmium and MT concentrations in bluegill liver and whole-body cadmium concentrations in bluegills were positively correlated with the cadmium concentrations in filtered water, resuspended sediment, and bulk river sediment; however, whole-body cadmim concentrations were a more sensitive indicator of exposure to sediment-associated cadmium than either free cadmium or MT concentratons in liver.

  16. Whole-lake invasive crayfish removal and qualitative modeling reveal habitat-specific food web topology

    DOE PAGES

    Hansen, Gretchen J. A.; Tunney, Tyler D.; Winslow, Luke A.; ...

    2017-02-10

    Patterning of the presence/absence of food web linkages (hereafter topology) is a fundamental characteristic of ecosystems that can influence species responses to perturbations. However, the insight from food web topology into dynamic effects of perturbations on species is potentially hindered because most described topologies represent data integrated across spatial and temporal scales. We conducted a 10-year, whole-lake experiment in which we removed invasive rusty crayfish (Orconectes rusticus) from a 64-ha north-temperate lake and monitored responses of multiple trophic levels. We compared species responses observed in two sub-habitats to the responses predicted from all topologies of an integrated, literature-informed base foodmore » web model of 32 potential links. Out of 4.3 billion possible topologies, only 308,833 (0.0072%) predicted responses that qualitatively matched observed species responses in cobble habitat, and only 12,673 (0.0003%) matched observed responses in sand habitat. Furthermore, when constrained to predictions that both matched observed responses and were highly reliable (i.e., predictions were robust to link strength values), only 5040 (0.0001%) and 140 (0.000003%) topologies were identified for cobble and sand habitats, respectively. A small number of linkages were nearly always present in these valid, reliable networks in sand, while a greater variety of possible network configurations were possible in cobble. Direct links involving invasive rusty crayfish were more important in cobble, while indirect effects involving Lepomis spp. were more important in sand. Importantly, the importance of individual species linkages differed dramatically among cobble and sand sub-habitats within a single lake, even though species composition was identical. Furthermore the true topology of food webs is difficult to determine, constraining topologies to include spatial resolution that matches observed experimental outcomes may reduce possibilities to

  17. Predator avoidance, microhabitat shift, and risk-sensitive foraging in larval dragonflies.

    PubMed

    Pierce, C L

    1988-10-01

    Dragonfly larvae (Odonata: Anisoptera) are often abundant in shallow freshwater habitats and frequently co-occur with predatory fish, but there is evidence that they are underutilized as prey. This suggests that species which successfully coexist with fish may exhibit behaviors that minimize their risk of predation. I conducted field and laboratory experiments to determine whether: 1) dragonfly larvae actively avoid fish, 2) microhabitat use and foraging success of larvae are sensitive to predation risk, and 3) vulnerability of larvae is correlated with microhabitat use. I experimentally manipulated the presence of adult bluegills (Lepomis macrochirus) in defaunated patches of littoral substrate in a small pond to test whether colonizing dragonfly larvae would avoid patches containing fish. The two dominant anisopteran species, Tetragoneuria cynosura and Ladona deplanata (Odonata: Libellulidae), both strongly avoided colonizing patches where adult bluegills were present. Laboratory experiments examined the effects of diel period and bluegills on microhabitat use and foraging success, using Tetragoneuria, Ladona and confamilial Sympetrum semicictum, found in a nearby fishless pond. Tetragoneuria and Ladona generally occupied microhabitats offering cover, whereas Sympetrum usually occupied exposed locations. Bluegills induced increased use of cover in all three species, and use of cover also tended to be higher during the day than at night. Bluegills depressed foraging in Tetragoneuria and to a lesser extent in Ladona, but foraging in Sympetrum appeared unaffected. Other laboratory experiments indicated that Sympetrum were generally more vulnerable than Tetragoneuria or Ladona to bluegill predation, and that vulnerability was positively correlated with use of exposed microhabitats. Both fixed (generally low use of exposed microhabitats, diel microhabitat shifts) and reactive (predator avoidance, predator-sensitive microhabitat shifts) behavioral responses appear to

  18. CRITICAL ILLUMINATION AND CRITICAL FREQUENCY FOR RESPONSE TO FLICKERED LIGHT, IN DRAGONFLY LARVAE

    PubMed Central

    Crozier, W. J.; Wolf, Ernst; Zerrahn-Wolf, Gertrud

    1937-01-01

    Curves relating flicker frequency (F) to mean critical illumination (Im) for threshold response to flickered light, with equal durations of light and no light intervals, and relating illumination (I) to mean critical flicker frequency (Fm) for the same response, have been obtained from homogeneous data based upon the reactions of dragonfly larvae (Anax junius). These curves exhibit the properties already described in the case of the fish Lepomis. The curve for Fm lies above the curve of Im by an amount which, as a function of I, can be predicted from a knowledge either of the variation of Im or of Fm. The law of the observable connection between F and I is properly expressed as a band, not as a simple curve. The variation of Im (and of Fm) is not due to "experimental error," but is an expression of the variable character of the organism's capacity to exhibit the reaction which is the basis of the measurements. As in other series of measurements, P.E.I is a rectilinear function of Im; P.E.F passes through a maximum as F (or I) increases. The form of P.E.F as a function of I can be predicted from the measurements of P.E.I. It is pointed out that the equations which have been proposed for the interpretation of curves of critical flicker frequency as a function of intensity, based upon the balance of light adaptation and dark adaptation, have in fact the character of "population curves;" and that their contained constants do not have the properties requisite for the consistent application of the view that the shape of the F - I curve is governed by the steady state condition of adaptation. These curves can, however, be understood as resulting from the achievement of a certain level of difference between the average effect of a light flash and its average after effect during the dark interval. PMID:19872997

  19. Effects of depletion sampling by standard three-pass pulsed DC electrofishing on blood chemistry parameters of fishes from Appalachian streams

    USGS Publications Warehouse

    Densmore, Christine L.; Panek, Frank M.

    2013-01-01

    Adverse effects on fishes captured by electrofishing techniques have long been recognized, although the extent of associated physical injury and behavioral alterations are highly variable and dependent on a number of factors. We examined the effects of three-pass pulsed DC (PDC) electrofishing on two salmonid species (Rainbow Trout Oncorhynchus mykiss and Brook Trout Salvelinus fontinalis) and five other genera (Green Sunfish Lepomis cyanellus, Potomac Sculpin Cottus girardi, Fathead Minnow Pimephales promelas, Largemouth Bass Micropterus salmoides, and Channel Catfish Ictalurus punctatus) common to Appalachian streams. We examined the corresponding effects of PDC electroshock on the following physiological indicators of stress and trauma: blood glucose and serum lactate, as well as on other blood chemistry, namely, enzymes, electrolytes, minerals, and proteins. All species demonstrated physiological responses to PDC electroshock, indicated by the biochemical differences in blood parameters in unshocked and shocked groups of fish with or without gross evidence of hemorrhagic trauma. Serum lactate was the most consistent indicator of these effects. Significant differences in whole blood glucose levels were also noted in treatment groups in all species except Green Sunfish, although the patterns observed were not as consistent as for serum lactate. Elevations in the serum enzymes, aspartate aminotransferase and creatine kinase, in the electroshocked fish occurred only in the two salmonid species. In many instances, although blood parameters were elevated in electroshocked fish compared with the unshocked controls for a given species, there were no differences in those levels in electroshocked fish based on the presence of gross hemorrhagic trauma to axial musculature. While some of the blood parameters examined correlated with both the occurrence of electroshock and the resultant tissue injury, there was no apparent link between the altered blood chemistry and

  20. Summary of total mercury concentrations in fillets of selected sport fishes collected during 2000-2003 from Lake Natoma, Sacramento County, California

    USGS Publications Warehouse

    Saiki, Michael K.; Slotton, Darrell G.; May, Thomas W.; Ayers, Shaun M.; Alpers, Charles N.

    2004-01-01

    This report summarizes results of total mercury measurements in skinless fillets of sport fishes collected during August 2000, September?October 2002, and July 2003 from Lake Natoma, a small (8,760 acre-feet) afterbay for Folsom Dam on the lower American River. The primary objective of the study was to determine if mercury concentrations in fillets approached or exceeded guidelines for human consumption. The Food and Drug Administration (FDA) human-health action level for methylmercury in commercially caught fish is 1.0 ?g/g (microgram per gram); the U.S. Environmental Protection Agency (USEPA) human-health criterion for methylmercury residue in fish tissue is 0.30 ?g/g. Wet weight concentrations of total mercury in skinless fillets were as high as 0.19 ?g/g in bluegill (Lepomis macrochirus), 0.39 ?g/g in redear sunfish (L. microlophus), 1.02 ?g/g in largemouth bass (Micropterus salmoides), and 1.89 ?g/g in channel catfish (Ictalurus punctatus). Maximum concentrations of mercury in other fish species varied from 0.10 ?g/g in rainbow trout (Oncorhynchus mykiss) to 0.56 ?g/g in white catfish (A-meiurus catus). Altogether, 1 of 86 largemouth bass and 11 of 11 channel catfish exceeded the FDA human-health action level. In addition, 1 of 20 redear sunfish, 26 of 86 largemouth bass, 2 of 3 spotted bass (M. punctulatus), 1 of 1 brown bullhead (A. nebulosus), and 1 of 1 white catfish exceeded the USEPA human-health criterion. These results indicate that some fish species inhabiting Lake Natoma contain undesirably high concentrations of mercury in their skinless fillets.

  1. Predicting propulsive forces using distributed sensors in a compliant, high DOF, robotic fin.

    PubMed

    Kahn, Jeff C; Peretz, David J; Tangorra, James L

    2015-05-18

    Engineered robotic fins have adapted principles of propulsion from bony-finned fish, using spatially-varying compliance and complex kinematics to produce and control the fin's propulsive force through time. While methods of force production are well understood, few models exist to predict the propulsive forces of a compliant, high degree of freedom, robotic fin as it moves through fluid. Inspired by evidence that the bluegill sunfish (Lepomis macrochirus) has bending sensation in its pectoral fins, the objective of this study is to understand how sensors distributed within a compliant robotic fin can be used to estimate and predict the fin's propulsive force. A biorobotic model of a bluegill sunfish pectoral fin was instrumented with pressure and bending sensors at multiple locations. Experiments with the robotic fin were executed that varied the swimming gait, flapping frequency, stroke phase, and fin stiffness to understand the forces and sensory measures that occur during swimming. A convolution-based, multi-input-single-output (MISO) model was selected to model and study the relationships between sensory data and propulsive force. Subsets of sensory data were studied to determine which sensor modalities and sensor placement locations resulted in the best force predictions. The propulsive forces of the fin were accurately predicted using the linear MISO model on intrinsic sensory data. Bending sensation was more effective than pressure sensation for predicting propulsive forces, and the importance of bending sensation was consistent with several results in biology and engineering studies. It was important to have a spatial distribution of sensors and multiple sensory modalities in order to predict forces across large changes to dynamics. The relationship between propulsive forces and intrinsic sensory measures is complex, and good models should allow for temporal lags between forces and sensory data, changes to the model within a fin stroke, and changes to the

  2. A robotic fish caudal fin: effects of stiffness and motor program on locomotor performance.

    PubMed

    Esposito, Christopher J; Tangorra, James L; Flammang, Brooke E; Lauder, George V

    2012-01-01

    We designed a robotic fish caudal fin with six individually moveable fin rays based on the tail of the bluegill sunfish, Lepomis macrochirus. Previous fish robotic tail designs have loosely resembled the caudal fin of fishes, but have not incorporated key biomechanical components such as fin rays that can be controlled to generate complex tail conformations and motion programs similar to those seen in the locomotor repertoire of live fishes. We used this robotic caudal fin to test for the effects of fin ray stiffness, frequency and motion program on the generation of thrust and lift forces. Five different sets of fin rays were constructed to be from 150 to 2000 times the stiffness of biological fin rays, appropriately scaled for the robotic caudal fin, which had linear dimensions approximately four times larger than those of adult bluegill sunfish. Five caudal fin motion programs were identified as kinematic features of swimming behaviors in live bluegill sunfish, and were used to program the kinematic repertoire: flat movement of the entire fin, cupping of the fin, W-shaped fin motion, fin undulation and rolling movements. The robotic fin was flapped at frequencies ranging from 0.5 to 2.4 Hz. All fin motions produced force in the thrust direction, and the cupping motion produced the most thrust in almost all cases. Only the undulatory motion produced lift force of similar magnitude to the thrust force. More compliant fin rays produced lower peak magnitude forces than the stiffer fin rays at the same frequency. Thrust and lift forces increased with increasing flapping frequency; thrust was maximized by the 500× stiffness fin rays and lift was maximized by the 1000× stiffness fin rays.

  3. Comparative Evaluation of Four Presumptive Tests for Blood to Detect Epithelial Injury on Fish

    SciTech Connect

    Colotelo, Alison HA; Smokorowski, Karen; Haxton, Tim; Cooke, Steven J.

    2014-06-01

    Current methods of fish epithelial injury detection are limited to gross macroscopic examination that has a subjective bias as well as an inability to reliably quantify the degree of injury. Fluorescein, a presumptive test for blood, has been shown to have the capability to detect and quantify fish epithelial injury. However, there are several other presumptive tests for blood (Bluestar*, phenolphthalein, and HemastixH) that may have benefits over the use of fluorescein, particularly for field research on wild fish. This study investigated the capabilities of these four tests to detect and quantify a variety of injuries commonly encountered by fish (abrasion, cuts, fin frays, and punctures) using the freshwater bluegill Lepomis macrochirus as a model. Fluorescein was consistently found to be the most reliable (i.e., detected the highest proportion of true positive results and rarely detected false positive reactions) of the four presumptive tests for blood compared. Further testing was conducted to examine the reliability of fluorescein. By 24 h after an injury was inflicted, the injury was no longer detectable by fluorescein, and when fluorescein was applied to an injured fish, the fluorescein was no longer detectable 3 h after application. In a comparison of two common anaesthetics used in fisheries research, there was no significant difference in the proportion of injury detected when 3- aminobenzoic acid ethyl ester methanesulfate (tricaine) was used compared with a clove oil and ethanol (1:9) solution. In summary, fluorescein was the most reliable presumptive test for blood examined in this study for the detection and quantification of recent (hours) fish epithelial injury.

  4. Effect and acceptance of bluegill length limits in Nebraska natural lakes

    USGS Publications Warehouse

    Paukert, C.P.; Willis, D.W.; Gabelhouse, D.W.

    2002-01-01

    Bluegill Lepomis macrochirus populations in 18 Nebraska Sandhill lakes were evaluated to determine if a 200-mm minimum length limit would increase population size structure. Bluegills were trap-netted in May and June 1998 and 1999, and a creel survey was conducted during winter 1998-2001 on one or two lakes where bluegills had been tagged to determine angler exploitation. Thirty-three percent of anglers on one creeled lake were trophy anglers (i.e., fishing for large [???250 mm] bluegills), whereas 67% were there to harvest fish to eat. Exploitation was always less than 10% and the total annual mortality averaged 40% across all 18 lakes. The time to reach 200 mm ranged from 4.3 to 8.3 years. The relative stock density of preferred-length fish increased an average of 2.2 units in all 18 lakes with a 10% exploitation rate. However, yield declined 39% and the number harvested declined 62%. Bluegills would need to reach 200 mm in 4.2 years to ensure no reduction in yield at 10% exploitation. Both yield and size structure were higher with a 200-mm minimum length limit (relative to having no length limit) only in populations with the lowest natural mortality and at exploitation of 30% or more. Although 100% (N = 39) of anglers surveyed said they would favor a 200-mm minimum length limit to improve bluegill size structure, anglers would have to sacrifice harvest to achieve this goal. While a 200-mm minimum length limit did minimally increase size structure at current levels of exploitation across all 18 bluegill populations, the populations with the lowest natural mortality and fastest growth provided the highest increase in size structure with the lowest reduction in yield and number harvested.

  5. Movement, home range, and site fidelity of bluegills in a Great Plains Lake

    USGS Publications Warehouse

    Paukert, C.P.; Willis, D.W.; Bouchard, M.A.

    2004-01-01

    Little is known about the distribution, movement, and home ranges of bluegills Lepomis macrochirus in lentic environments. Therefore, the objectives of this study were to evaluate the seasonal and diel differences in movement rates, site fidelity, and home range of bluegills in a shallow, natural Great Plains lake. A total of 78 bluegills (200-273 mm total length) were implanted with radio transmitters in March and May 2000. Of these fish, 10 males and 10 females were randomly selected and located every 2 h during one 24-h period each month from April to September 2000. Bluegill movement peaked during midsummer: however, there was little difference in diel movements, suggesting relatively consistent movement throughout the 24-h period. Home range estimates (which included the 24-h tracking plus an additional six locations from the same fish located once per day for six consecutive days each month) ranged up to 172 ha, probably because only about half of the bluegills exhibited site fidelity during any month sampled. Bluegill movement did not appear to be strongly linked with water temperature, barometric pressure, or wind speed. These results suggest that bluegills move considerable distances and that many roam throughout this 332-ha shallow lake. However, diel patterns were not evident. Sampling bluegills in Great Plains lakes using passive gears (e.g., trap nets) may be most effective during the summer months, when fish are most active. Active sampling (e.g., electrofishing) may be more effective than the use of passive gears in spring and fall, when bluegills are less active.

  6. Chemical Defense of the Eastern Newt (Notophthalmus viridescens): Variation in Efficiency against Different Consumers and in Different Habitats

    PubMed Central

    Marion, Zachary H.; Hay, Mark E.

    2011-01-01

    Amphibian secondary metabolites are well known chemically, but their ecological functions are poorly understood—even for well-studied species. For example, the eastern newt (Notophthalmus viridescens) is a well known secretor of tetrodotoxin (TTX), with this compound hypothesized to facilitate this salamander's coexistence with a variety of aquatic consumers across the eastern United States. However, this assumption of chemical defense is primarily based on observational data with low replication against only a few predator types. Therefore, we tested the hypothesis that N. viridescens is chemically defended against co-occurring fishes, invertebrates, and amphibian generalist predators and that this defense confers high survivorship when newts are transplanted into both fish-containing and fishless habitats. We found that adult eastern newts were unpalatable to predatory fishes (Micropterus salmoides, Lepomis macrochirus) and a crayfish (Procambarus clarkii), but were readily consumed by bullfrogs (Lithobates catesbeianus). The eggs and neonate larvae were also unpalatable to fish (L. macrochirus). Bioassay-guided fractionation confirmed that deterrence is chemical and that ecologically relevant concentrations of TTX would deter feeding. Despite predatory fishes rejecting eastern newts in laboratory assays, field experiments demonstrated that tethered newts suffered high rates of predation in fish-containing ponds. We suggest that this may be due to predation by amphibians (frogs) and reptiles (turtles) that co-occur with fishes rather than from fishes directly. Fishes suppress invertebrate consumers that prey on bullfrog larvae, leading to higher bullfrog densities in fish containing ponds and thus considerable consumption of newts due to bullfrog tolerance of newt chemical defenses. Amphibian chemical defenses, and consumer responses to them, may be more complex and indirect than previously appreciated. PMID:22164212

  7. Undulatory locomotion of flexible foils as biomimetic models for understanding fish propulsion.

    PubMed

    Shelton, Ryan M; Thornycroft, Patrick J M; Lauder, George V

    2014-06-15

    An undulatory pattern of body bending in which waves pass along the body from head to tail is a major mechanism of creating thrust in many fish species during steady locomotion. Analyses of live fish swimming have provided the foundation of our current understanding of undulatory locomotion, but our inability to experimentally manipulate key variables such as body length, flexural stiffness and tailbeat frequency in freely swimming fish has limited our ability to investigate a number of important features of undulatory propulsion. In this paper we use a mechanical flapping apparatus to create an undulatory wave in swimming flexible foils driven with a heave motion at their leading edge, and compare this motion with body bending patterns of bluegill sunfish (Lepomis macrochirus) and clown knifefish (Notopterus chitala). We found similar swimming speeds, Reynolds and Strouhal numbers, and patterns of curvature and shape between these fish and foils, suggesting that flexible foils provide a useful model for understanding fish undulatory locomotion. We swam foils with different lengths, stiffnesses and heave frequencies while measuring forces, torques and hydrodynamics. From measured forces and torques we calculated thrust and power coefficients, work and cost of transport for each foil. We found that increasing frequency and stiffness produced faster swimming speeds and more thrust. Increasing length had minimal impact on swimming speed, but had a large impact on Strouhal number, thrust coefficient and cost of transport. Foils that were both stiff and long had the lowest cost of transport (in mJ m(-1) g(-1)) at low cycle frequencies, and the ability to reach the highest speed at high cycle frequencies. © 2014. Published by The Company of Biologists Ltd.

  8. Molecular Zoogeography of Freshwater Fishes in the Southeastern United States

    PubMed Central

    Bermingham, Eldredge; Avise, John C.

    1986-01-01

    Restriction fragment length polymorphisms in mitochondrial DNA (mtDNA) were used to reconstruct evolutionary relationships of conspecific populations in four species of freshwater fish—Amia calva, Lepomis punctatus, L. gulosus, and L. microlophus. A suite of 14-17 endonucleases was employed to assay mtDNAs from 305 specimens collected from 14 river drainages extending from South Carolina to Louisiana. Extensive mtDNA polymorphism was observed within each assayed species. In both phenograms and Wagner parsimony networks, mtDNA clones that were closely related genetically were usually geographically contiguous. Within each species, major mtDNA phylogenetic breaks also distinguished populations from separate geographic regions, demonstrating that dispersal and gene flow have not been sufficient to override geographic influences on population subdivision.—Importantly, there were strong patterns of congruence across species in the geographic placements of the mtDNA phylogenetic breaks. Three major boundary regions were characterized by concentrations of phylogenetic discontinuities, and these zones agree well with previously described zoogeographic boundaries identified by a different kind of data base—distributional limits of species—suggesting that a common set of historical factors may account for both phenomena. Repeated episodes of eustatic sea level change along a relatively static continental morphology are the likely causes of several patterns of drainage isolation and coalescence, and these are discussed in relation to the genetic data.—Overall, results exemplify the positive role that intraspecific genetic analyses may play in historical zoogeographic reconstruction. They also point out the potential inadequacies of any interpretations of population genetic structure that fail to consider the influences of history in shaping that structure. PMID:17246340

  9. Quantifying precision of in situ length and weight measurements of fish

    USGS Publications Warehouse

    Gutreuter, S.; Krzoska, D.J.

    1994-01-01

    We estimated and compared errors in field-made (in situ) measurements of lengths and weights of fish. We made three measurements of length and weight on each of 33 common carp Cyprinus carpio, and on each of a total of 34 bluegills Lepomis macrochirus and black crappies Pomoxis nigromaculatus. Maximum total lengths of all fish were measured to the nearest 1 mm on a conventional measuring board. The bluegills and black crappies (85–282 mm maximum total length) were weighed to the nearest 1 g on a 1,000-g spring-loaded scale. The common carp (415–600 mm maximum total length) were weighed to the nearest 0.05 kg on a 20-kg spring-loaded scale. We present a statistical model for comparison of coefficients of variation of length (Cl ) and weight (Cw ). Expected Cl was near zero and constant across mean length, indicating that length can be measured with good precision in the field. Expected Cw decreased with increasing mean length, and was larger than expected Cl by 5.8 to over 100 times for the bluegills and black crappies, and by 3 to over 20 times for the common carp. Unrecognized in situ weighing errors bias the apparent content of unique information in weight, which is the information not explained by either length or measurement error. We recommend procedures to circumvent effects of weighing errors, including elimination of unnecessary weighing from routine monitoring programs. In situ weighing must be conducted with greater care than is common if the content of unique and nontrivial information in weight is to be correctly identified.

  10. Hepatic cadmium, metal-binding proteins and bioaccumulation in bluegills exposed to aqueous cadmium

    USGS Publications Warehouse

    Cope, W.G.; Atchison, G.J.; Wiener, J.G.

    1994-01-01

    We examined sublethal responses of juvenile bluegills Lepomis macrochirus to aqueous cadmium in two 28-d tests (test I, 0.0-8.4 μg Cd per liter; test II, 0.0-32.3 μg Cd per liter) in an intermittent-flow diluter. The experimental design was completely randomized, with two replicates in each of eight treatments (seven Cd exposures and one water control with 25 fish per replicate). Cadmium did not affect the growth of test fish. The mean whole-body concentrations of Cd in exposed fish were 1.8- to 44-fold those in controls in the two tests. Mean concentrations of hepatic nonthionein cytosolic Cd (not bound by metal-binding proteins, MBP) in all Cd treatments greatly exceeded those in controls, and mean concentrations of hepatic MBP in all treatments except one (0.8 μg Cd per liter in test I) exceeded those in controls. Nonthionein cytosolic Cd, hepatic MBP, and whole-body Cd in bluegills were linearly related to exposure concentrations within the range 0 to 20 μg Cd per liter. Much of the total Cd-binding capacity of hepatic MBP per fish was occupied by Cd after the 28-d exposures, although additional Cd-binding capacity remained unoccupied by Cd in fish in all treatments. The mean total Cd-binding capacity of hepatic MBP per fish, which ranged from 1.7 to 14 nmol Cd in test I and from 0.8 to 24 nmol Cd in test II, increased in a concentration-response manner at exposure concentrations below 13 μg/L. Nonthionein cytosolic Cd was the most sensitive indicator of Cd exposure, based on an LOEC of 0.8 μg Cd per liter.

  11. Potential Reservoirs and Risk Factors for VHSV IVb in an Enzootic System: Budd Lake, Michigan.

    PubMed

    Throckmorton, Elizabeth; Brenden, Travis; Peters, Amber K; Newcomb, Tammy J; Whelan, Gary E; Faisal, Mohamed

    2017-03-01

    Viral hemorrhagic septicemia virus genotype IVb (VHSV IVb) has caused major, sporadic fish die-offs in the Laurentian Great Lakes region of North America since 2005. Presently, factors affecting VHSV IVb persistence in enzootic systems are not well understood. Even with annual surveillance, the virus can go undetected for several years after an outbreak before again re-emerging, which suggests that the virus is maintained in the system either below detectable levels or in untested reservoirs. The aim of this study was to identify potential reservoirs of VHSV IVb in Budd Lake, Michigan; VHSV IVb was first detected in Budd Lake in 2007 but remained undetected until 2011. Additionally, we explored the susceptibility of naive fish introduced into a water body enzootic for VHSV IVb by stocking age-0 Largemouth Bass Micropterus salmoides at varying densities into enclosures in the lake. The virus was not detected among samples of the fishes Notropis spp. and Lepomis spp., cylindrical papershell mussels Anodontoides ferussacianus, leeches (subclass Hirudinea), sediment, or water. However, the virus was successfully isolated from amphipods (family Hyalellidae) and Largemouth Bass held in the enclosures. Our finding of VHSV IVb in Hyalellidae amphipods in combination with other research that has detected the virus in Diporeia spp., a large benthic amphipod important as a food resource to Great Lake fishes, suggests that benthic macroinvertebrates are a reservoir for VHSV IVb in infected systems. If there are environmental reservoirs for VHSV IVb in infected systems, they are likely unevenly distributed. Findings of this study add to our understanding of the seemingly complex ecology of this deadly and economically detrimental virus. Received February 22, 2016; accepted October 16, 2016.

  12. Predation on exotic zebra mussels by native fishes: Effects on predator and prey

    USGS Publications Warehouse

    Magoulick, D.D.; Lewis, L.C.

    2002-01-01

    1. Exotic zebra mussels, Dreissena polymorpha, occur in southern U.S. waterways in high densities, but little is known about the interaction between native fish predators and zebra mussels. Previous studies have suggested that exotic zebra mussels are low profitability prey items and native vertebrate predators are unlikely to reduce zebra mussel densities. We tested these hypotheses by observing prey use of fishes, determining energy content of primary prey species of fishes, and conducting predator exclusion experiments in Lake Dardanelle, Arkansas. 2. Zebra mussels were the primary prey eaten by 52.9% of blue catfish, Ictalurus furcatus; 48.2% of freshwater drum, Aplodinotus grunniens; and 100% of adult redear sunfish, Lepomis microlophus. Blue catfish showed distinct seasonal prey shifts, feeding on zebra mussels in summer and shad, Dorosoma spp., during winter. Energy content (joules g-1) of blue catfish prey (threadfin shad, Dorosoma petenense; gizzard shad, D. cepedianum; zebra mussels; and asiatic clams, Corbicula fluminea) showed a significant species by season interaction, but shad were always significantly greater in energy content than bivalves examined as either ash-free dry mass or whole organism dry mass. Fish predators significantly reduced densities of large zebra mussels (>5 mm length) colonising clay tiles in the summers of 1997 and 1998, but predation effects on small zebra mussels (???5 mm length) were less clear. 3. Freshwater drum and redear sunfish process bivalve prey by crushing shells and obtain low amounts of higher-energy food (only the flesh), whereas blue catfish lack a shell-crushing apparatus and ingest large amounts of low-energy food per unit time (bivalves with their shells). Blue catfish appeared to select the abundant zebra mussel over the more energetically rich shad during summer, then shifted to shad during winter when shad experienced temperature-dependent stress and mortality. Native fish predators can suppress adult zebra

  13. Heavy metal distribution in tissues of six fish species included in human diet, inhabiting freshwaters of the Nature Park "Hutovo Blato" (Bosnia and Herzegovina).

    PubMed

    Has-Schön, Elizabeta; Bogut, Ivan; Rajković, Valentina; Bogut, Stjepan; Cacić, Milan; Horvatić, Janja

    2008-01-01

    The aim of the study was to quantify heavy metal (mercury, lead, cadmium, and arsenic) concentration in tissues (muscles, liver, kidney, gills, and gonads) of six fish species (carp: Cyprinus carpio, tench: Tinca tinca, pumpkinseed: Lepomis gibosus, prussian carp: Carassius auratus gibelio, hasselquist: Salmo dentex, eel: Anguilla anguilla) from the freshwaters of the Nature Park Hutovo Blato, Bosnia and Herzegovina, and determine whether they are potentially harmful for human health if included in the diet. Fish were angled from the Svitava Lake in the second part of August of the year 2003, and fish tissues were stored at -18 degrees C until analysis. Heavy metal concentration was determined by atomic absorption spectrophotometry in the Veterinary Institute Brno, Czech Republic, and expressed as mg.kg(-1) of wet tissue. Concentration of mercury, lead, and arsenic in most tissues of all analyzed fish types is lower than the maximal allowed concentration (MAC) in most countries. Cadmium concentration is also low in muscles and gonads, but kidney, liver, and gill concentrations exceed MAC value in most countries. Hasselquist, an endemic type for that region, differs from other fish types in the fact that it has very low cadmium concentration in liver and kidney, but the highest concentration of arsenic in most tissues, especially muscles. In muscles and gonads of all fish types analyzed, Pb is present in higher concentration than Cd, whereas in liver, gills, and particularly kidney, the situation is opposite, suggesting diverse metabolic pathways and unequal bioaccumulation of these two metals in different fish tissues. Although the region of the Nature Park Hutovo Blato in Bosnia and Herzegovina is not an agricultural territory, the intensive agricultural activities in the neighboring regions already result in high cadmium concentration in inner organs of fish species analyzed. Therefore, fish types in the freshwaters of the Park may be included in the human diet

  14. Early life history and spatiotemporal changes in distribution of the rediscovered Suwannee moccasinshell Medionidus walkeri (Bivalvia: Unionidae)

    USGS Publications Warehouse

    Johnson, Nathan A.; Mcleod, John; Holcomb, Jordan; Rowe, Matthew T.; Williams, James D.

    2016-01-01

    Accurate distribution data are critical to the development of conservation and management strategies for imperiled species, particularly for narrow endemics with life history traits that make them vulnerable to extinction. Medionidus walkeri is a rare freshwater mussel endemic to the Suwannee River Basin in southeastern North America. This species was rediscovered in 2012 after a 16-year hiatus between collections and is currently proposed for listing under the Endangered Species Act. Our study fills knowledge gaps regarding changes in distribution and early life history requirements of M. walkeri. Spatiotemporal changes in M. walkeri distribution were displayed using a conservation status assessment map incorporating metadata from 98 historical (1916–1999) and 401 recent (2000–2015) site surveys from museums and field notes representing records for 312 specimens. Recent surveys detected M. walkeri only in the middle Suwannee subbasin (n = 86, 22 locations) and lower Santa Fe subbasin (n = 2, 2 locations), and it appears the species may be extirpated from 67% of historically occupied 10-digit HUCs. In our laboratory experiments, M. walkeri successfully metamorphosed on Percina nigrofasciata (56.2% ± 8.9) and Etheostoma edwini (16.1% ± 7.9) but not on Trinectes maculatus, Lepomis marginatus, Notropis texanus, Noturus leptacanthus, Etheostoma fusiforme, or Gambusia holbrooki. We characterize M. walkeri as a lure-displaying host fish specialist and a long-term brooder (bradytictic), gravid from fall to early summer of the following year. The early life history and distribution data presented here provide the baseline framework for listing decisions and future efforts to conserve and recover the species.

  15. Effects of landscape change on fish assemblage structure in a rapidly growing metropolitan area in North Carolina, USA

    USGS Publications Warehouse

    Kennen, J.G.; Chang, M.; Tracy, B.H.

    2005-01-01

    We evaluated a comprehensive set of natural and land-use attributes that represent the major facets of urban development at fish monitoring sites in the rapidly growing Raleigh-Durham, North Carolina metropolitan area. We used principal component and correlation analysis to obtain a nonredundant subset of variables that extracted most variation in the complete set. With this subset of variables, we assessed the effect of urban growth on fish assemblage structure. We evaluated variation in fish assemblage structure with nonmetric multidimensional scaling (NMDS). We used correlation analysis to identify the most important environmental and landscape variables associated with significant NMDS axes. The second NMDS axis is related to many indices of land-use/land-cover change and habitat. Significant correlations with proportion of largest forest patch to total patch size (r = -0.460, P < 0.01), diversity of patch types (r = 0.554, P < 0.001), and population density (r = 0.385, P < 0.05) helped identify NMDS axis 2 as a disturbance gradient. Positive and negative correlations between the abundance of redbreast sunfish Lepomis auritus and bluehead chub Nocomis leptocephalus, respectively, and NMDS axis 2 also were evident. The North Carolina index of biotic integrity and many of its component metrics were highly correlated with urbanization. These results indicate that aquatic ecosystem integrity would be optimized by a comprehensive integrated management strategy that includes the preservation of landscape function by maximizing the conservation of contiguous tracts of forested lands and vegetative cover in watersheds. ?? 2005 by the American Fisheries Society.

  16. Tradeoffs of warm adaptation in aquatic ectotherms: Live fast, die young?

    PubMed

    Martinez, E; Porreca, A P; Colombo, R E; Menze, M A

    2016-01-01

    In the face of a changing climate, questions regarding sub-lethal effects of elevated habitat temperature on the physiology of ectotherms remain unanswered. In particular, long-term responses of ectotherms to the warming trend in tropical regions are unknown, and understudied due to the difficulties in specimen and community traceability. In freshwater lakes employed as cooling reservoirs for power plants, increased physiological stress from high water temperature can potentially alter the community structure of fishes. We employ this highly tractable system to assess how thermal regimes can alter the physiology and ecology of aquatic species. We documented a significantly reduced lifespan, growth performance, and a shift in the age structure towards younger individuals in the thermally- impacted Coffeen Lake population of bluegill (Lepomis macrochirus), compared to a non-impacted control group (Lake Mattoon). Average age calculated for the Lake Mattoon population was 2.42 years, whereas the average age of bluegill from Coffeen Lake was only 0.96 years, and average specimen mass in Lake Mattoon was more than six times that of Coffeen Lake. During laboratory cross-acclimation studies of bluegill from Lake Mattoon at 17.5 and 35.0°C, citrate synthase (CS) activity obtained from white muscle was regulated through acclimation, whereas cold-acclimated specimens exhibited twice the activity at 25°C, if compared to CS activity values from warm-acclimated specimens. This study raises the questions about the causal relationships between physiological performance and habitat temperature, in particular how thresholds in an organism's physiology may modulate their community structure, and consequently their ecological success. Copyright © 2015 Elsevier Inc. All rights reserved.

  17. Consumptive effects of fish reduce wetland crayfish recruitment and drive species turnover.

    PubMed

    Kellogg, Christopher M; Dorn, Nathan J

    2012-04-01

    Predators and dry-disturbances have pronounced effects on invertebrate communities and can deterministically affect compositional turnover between discrete aquatic habitats. We examined the effect of sunfish (Lepomis spp.) predators on two native crayfish, Procambarus alleni and P. fallax, that regionally coexist in an expansive connected wetland in order to test the hypotheses that sunfish predation limits crayfish recruitment (both species) and that it disproportionately affects P. alleni, the species inhabiting temporary wetlands. In replicate vegetated wetlands (18.6 m(2)), we quantified summertime crayfish recruitment and species composition across an experimental gradient of sunfish density. Separately, we quantified effects of sunfish on crayfish growth, conducted a complimentary predation assay in mesocosms, and compared behavior of the two crayfish. Sunfish reduced P. alleni summertime recruitment by >99% over the full sunfish gradient, and most of the effect was caused by low densities of sunfish (0.22-0.43 m(-2)). P. alleni dominated wetlands with few or no sunfish, but the composition shifted towards P. fallax dominance in wetlands with abundant sunfish. P. fallax survived better than P. alleni over 40 h in smaller mesocosms stocked with warmouth. Sunfish reduced P. fallax recruitment 62% in a second wetland experiment, but growth rates of caged crayfish (both species) were unaffected by sunfish presence, suggesting predatory effects were primarily consumptive. Consistent with life histories of relatively fish-sensitive invertebrates, P. alleni engaged in more risky behaviors in the laboratory. Our results indicate that sunfish predators limit recruitment of both species, but disproportionately remove the more active and competitively dominant P. alleni. Spatially and temporally variable dry-disturbances negatively co-varying with sunfish populations allow for regional coexistence of these two crayfish and may release populations of either species from

  18. Comparative toxicity of copper and acridine to fish, Daphnia and algae

    SciTech Connect

    Blaylock, B.G.; Frank, M.L.; McCarthy, J.F.

    1985-01-01

    A comparison was made of the sensitivity of fish, Daphnia and algae to the toxic effects of copper and acridine. A series of toxicity tests was conducted with these organisms, and the following biological endpoints determined: LC50s for fish, LC50s and effects on reproduction of Daphnia and 50% inhibition of the growth rate of algae. The 96-h LCO50s for bluegill (Lepomis macrochirus) and Daphnia magna exposed to copper were 2.2 and 0.13 mg/L, respectively. A chronic exposure to 0.03 mg/L of copper for 14 d significantly decreased reproduction in Daphnia. Exposure to 0.4 and 0.2 mg/L copper inhibited the growth rate of Selenastrum capricornutum and Chlorella vulgaris, respectively, by 50%. The 96-h LC50s for fathead minnows (Pimephales promelas) and D. magna exposed to acridine were 2.3 and 3.1 mg/L, respectively. A chronic exposure to 1.25 mg/L acridine for 14 d significantly inhibited reproduction in Daphnia, and an exposure to 0.9 mg/L inhibited the growth rate of S. capricornutum by 50%. Based on the biological endpoints determined in these tests, Daphnia were more sensitive to copper than were fish or algae. In contrast, the most sensitive biological endpoint in tests with acridine was the inhibition of algal growth. Comparison of these test results indicates that short-term toxicity tests used for screening toxicants for possible environmental effects should include both plant and animal species. 16 references, 4 figures, 4 tables.

  19. Aquatic toxicity of triclosan.

    PubMed

    Orvos, David R; Versteeg, Donald J; Inauen, Josef; Capdevielle, Marie; Rothenstein, Arthur; Cunningham, Virginia

    2002-07-01

    The aquatic toxicity of triclosan (TCS), a chlorinated biphenyl ether used as an antimicrobial in consumer products, was studied with activated-sludge microorganisms, algae, invertebrates, and fish. Triclosan, a compound used for inhibiting microbial growth, was not toxic to wastewater microorganisms at concentrations less than aqueous solubility. The 48-h Daphnia magna median effective concentration (EC50) was 390 microg/L and the 96-h median lethal concentration values for Pimephales promelas and Lepomis macrochirus were 260 and 370 microg/L, respectively. A no-observed-effect concentration (NOEC) and lowest-observed-effect concentration of 34.1 microg/L and 71.3 microg/L, respectively, were determined with an early life-stage toxicity test with Oncorhynchus mykiss. During a 96-h Scenedesmus study, the 96-h biomass EC50 was 1.4 microg/L and the 96-h NOEC was 0.69 microg/L. Other algae and Lemna also were investigated. Bioconcentration was assessed with Danio rerio. The average TCS accumulation factor over the five-week test period was 4,157 at 3 microg/L and 2,532 at 30 microg/L. Algae were determined to be the most susceptible organisms. Toxicity of a TCS-containing wastewater secondary effluent to P. promelas and Ceriodaphnia was evaluated and no observed differences in toxicity between control and TCS-treated laboratory units were detected. The neutral form of TCS was determined to be associated with toxic effects. Ionization and sorption will mitigate those effects in the aquatic compartment.

  20. Proterometra epholkos sp. n. (Digenea: Azygiidae) from Terrapin Creek, Alabama, USA: molecular characterization of life cycle, redescription of Proterometra albacauda, and updated lists of host and geographic locality records for Proterometra spp. in North America.

    PubMed

    Womble, Matthew R; Orélis-Ribeiro, Raphael; Bullard, Stephen A

    2015-02-01

    Proterometra epholkos sp. n. asexually reproduces in the stream dwelling prosobranch, Elimia cf. modesta (Cerithioidea: Pleuroceridae) and infects the buccal cavity epithelium of spotted bass, Micropterus punctulatus (Perciformes: Centrarchidae) in the Coosa River (Terrapin Creek; N33°51'36.56″, W85°31'28.15″; Cleburne County, Alabama, USA). We characterize cercariae and adults of the new species using morphology and molecular sequence data and redescribe its morphologically similar congener Proterometra albacauda based on the holotype and paratype (USNPC Nos. 61229-30). The new species can be distinguished most easily from P. albacauda by the combination of having cercariae with long mamillae (>100μm) that encircle the tail stem anteriorly, that are restricted to 1 lateral column per body margin at midbody, and that are absent from the medial surface of the tail stem as well as by having adults with a partly extracecal uterus, a transverse metraterm occupying the space between the oral sucker and prostatic sac, and a vitellarium that is longer than the ceca and extends anteriad to the level of or beyond the posterior margin of the oral sucker. Sequence data from the ribosomal internal transcribed spacer 2 (ITS2; 251bp) did not reject the notion that the cercariae and adults we collected simultaneously from those infected, sympatric, individual snails and fish in Terrapin Creek were conspecific. Also provided herein for species of Proterometra are (i) taxonomic keys for cercariae and adults based on morphological and behavioral characteristics sourced from the published literature, (ii) updated lists of host records (prosobranchs and fishes) and geographic locality records for Proterometra spp., and (iii) synopses and assessments of the morphological features previously used to differentiate them. Proterometra macrostoma (type species), Proterometra melanophora, and Proterometra hodgesiana are species inquirendae; requiring new collections from type

  1. Phylogeny and temporal diversification of darters (Percidae: Etheostomatinae).

    PubMed

    Near, Thomas J; Bossu, Christen M; Bradburd, Gideon S; Carlson, Rose L; Harrington, Richard C; Hollingsworth, Phillip R; Keck, Benjamin P; Etnier, David A

    2011-10-01

    Discussions aimed at resolution of the Tree of Life are most often focused on the interrelationships of major organismal lineages. In this study, we focus on the resolution of some of the most apical branches in the Tree of Life through exploration of the phylogenetic relationships of darters, a species-rich clade of North American freshwater fishes. With a near-complete taxon sampling of close to 250 species, we aim to investigate strategies for efficient multilocus data sampling and the estimation of divergence times using relaxed-clock methods when a clade lacks a fossil record. Our phylogenetic data set comprises a single mitochondrial DNA (mtDNA) gene and two nuclear genes sampled from 245 of the 248 darter species. This dense sampling allows us to determine if a modest amount of nuclear DNA sequence data can resolve relationships among closely related animal species. Darters lack a fossil record to provide age calibration priors in relaxed-clock analyses. Therefore, we use a near-complete species-sampled phylogeny of the perciform clade Centrarchidae, which has a rich fossil record, to assess two distinct strategies of external calibration in relaxed-clock divergence time estimates of darters: using ages inferred from the fossil record and molecular evolutionary rate estimates. Comparison of Bayesian phylogenies inferred from mtDNA and nuclear genes reveals that heterospecific mtDNA is present in approximately 12.5% of all darter species. We identify three patterns of mtDNA introgression in darters: proximal mtDNA transfer, which involves the transfer of mtDNA among extant and sympatric darter species, indeterminate introgression, which involves the transfer of mtDNA from a lineage that cannot be confidently identified because the introgressed haplotypes are not clearly referable to mtDNA haplotypes in any recognized species, and deep introgression, which is characterized by species diversification within a recipient clade subsequent to the transfer of

  2. Water-quality, sediment-quality, stream-habitat, and biological data for Mustang Bayou near Houston, Texas, 2004-05

    USGS Publications Warehouse

    Sneck-Fahrer, Debra A.; East, Jeffery W.

    2007-01-01

    the stream bottom at M1 and analyzed for concentrations of trace elements (metals), polycyclic aromatic hydrocarbons, organochlorine pesticides, and polychlorinated biphenyls. No organochlorine pesticides or polychlorinated biphenyls were detected. No concentrations of metals exceeded State screening levels. Measurable concentrations of 11 polycyclic aromatic hydrocarbon (PAH) compounds were detected, and three other PAH compounds were detected but not quantified by the laboratory. Stream habitat and aquatic biota (benthic macroinvertebrates and fish) were surveyed at each site three times during the study to evaluate aquatic life use. Characteristics of habitat measured during each survey were scored using a habitat quality index. Average aquatic-life-use scores were 'limited' for M3-M6 and 'intermediate' for M1 and M2. A total of 2,557 macroinvertebrate individuals were identified from Mustang Bayou. Benthic macroinvertebrate assemblages were scored using indexes specified by the Texas Commission on Environmental Quality. Average aquatic-life-use scores were 'limited' at M1, 'intermediate' at M3-M6, and 'high' at M2. Forty-six species of fish representing 20 families were collected from Mustang Bayou. A total of 4,115 fish were collected. Sunfish (Centrarchidae) was the most abundant family, accounting for about 28 percent. Aquatic-life-use scores at sites in Mustang Bayou were determined using the regional index of biotic integrity for ecoregion 34 and were 'high' for all sites.

  3. Accumulation of metals in fish from lead-zinc mining areas of southeastern Missouri, USA

    USGS Publications Warehouse

    Schmitt, Christopher J.; Brumbaugh, William G.; May, Thomas W.

    2007-01-01

    The potential effects of proposed lead-zinc mining in an ecologically sensitive area were assessed by studying a nearby mining district that has been exploited for about 30 yr under contemporary environmental regulations and with modern technology. Blood and liver samples representing fish of three species (largescale stoneroller, Campostoma oligolepis, n=91; longear sunfish, Lepomis megalotis, n=105; and northern hog sucker, Hypentelium nigricans, n=20) were collected from 16 sites representing a range of conditions relative to lead-zinc mining and ore beneficiation in southeastern Missouri. Samples were analyzed for lead, zinc, and cadmium, and for a suite of biomarkers (reported in a companion paper). A subset of the hog sucker (n=9) representing three sites were also analyzed for nickel and cobalt. Blood and liver lead concentrations were highly correlated (r=0.84-0.85, P < 0.01) in all three species and were significantly (ANOVA, P < 0.01) greater at sites < 10 km downstream of active lead-zinc mines and mills and in a historical lead-zinc mining area than at reference sites, including a site in the area proposed for new mining. Correlations between blood and liver cadmium concentrations were less evident than for lead but were nevertheless statistically significant (r=0.26-0.69, P < 0.01-0.07). Although blood and liver cadmium concentrations were highest in all three species at sites near mines, within-site variability was greater and mining-related trends were less evident than for lead. Blood and liver zinc concentrations were significantly correlated only in stoneroller (r=0.46, P < 0.01) and mining-related trends were not evident. Concentrations of cobalt and nickel in blood and liver were significantly higher (ANOVA, P < 0.01) at a site near an active mine than at a reference site and a site in the historical lead-zinc mining area. These findings confirm previous studies indicating that lead and other metals are released to streams from active lead

  4. Locomotor forces on a swimming fish: three-dimensional vortex wake dynamics quantified using digital particle image velocimetry.

    PubMed

    Drucker; Lauder

    1999-01-01

    Quantifying the locomotor forces experienced by swimming fishes represents a significant challenge because direct measurements of force applied to the aquatic medium are not feasible. However, using the technique of digital particle image velocimetry (DPIV), it is possible to quantify the effect of fish fins on water movement and hence to estimate momentum transfer from the animal to the fluid. We used DPIV to visualize water flow in the wake of the pectoral fins of bluegill sunfish (Lepomis macrochirus) swimming at speeds of 0.5-1.5 L s(-)(1), where L is total body length. Velocity fields quantified in three perpendicular planes in the wake of the fins allowed three-dimensional reconstruction of downstream vortex structures. At low swimming speed (0.5 L s(-)(1)), vorticity is shed by each fin during the downstroke and stroke reversal to generate discrete, roughly symmetrical, vortex rings of near-uniform circulation with a central jet of high-velocity flow. At and above the maximum sustainable labriform swimming speed of 1.0 L s(-)(1), additional vorticity appears on the upstroke, indicating the production of linked pairs of rings by each fin. Fluid velocity measured in the vicinity of the fin indicates that substantial spanwise flow during the downstroke may occur as vortex rings are formed. The forces exerted by the fins on the water in three dimensions were calculated from vortex ring orientation and momentum. Mean wake-derived thrust (11.1 mN) and lift (3.2 mN) forces produced by both fins per stride at 0.5 L s(-)(1) were found to match closely empirically determined counter-forces of body drag and weight. Medially directed reaction forces were unexpectedly large, averaging 125 % of the thrust force for each fin. Such large inward forces and a deep body that isolates left- and right-side vortex rings are predicted to aid maneuverability. The observed force balance indicates that DPIV can be used to measure accurately large-scale vorticity in the wake of

  5. A hydrodynamic analysis of fish swimming speed: wake structure and locomotor force in slow and fast labriform swimmers.

    PubMed

    Drucker, E G; Lauder, G V

    2000-08-01

    Past study of interspecific variation in the swimming speed of fishes has focused on internal physiological mechanisms that may limit the ability of locomotor muscle to generate power. In this paper, we approach the question of why some fishes are able to swim faster than others from a hydrodynamic perspective, using the technique of digital particle image velocimetry which allows measurement of fluid velocity and estimation of wake momentum and mechanical forces for locomotion. We investigate the structure and strength of the wake in three dimensions to determine how hydrodynamic force varies in two species that differ markedly in maximum swimming speed. Black surfperch (Embiotoca jacksoni) and bluegill sunfish (Lepomis macrochirus) swim at low speeds using their pectoral fins exclusively, and at higher speeds switch to combined pectoral and caudal fin locomotion. E. jacksoni can swim twice as fast as similarly sized L. macrochirus using the pectoral fins alone. The pectoral fin wake of black surfperch at all speeds consists of two distinct vortex rings linked ventrally. As speed increases from 1.0 to 3.0 L s(-)(1), where L is total body length, the vortex ring formed on the fin downstroke reorients to direct force increasingly downstream, parallel to the direction of locomotion. The ratio of laterally to downstream-directed force declines from 0.93 to 0.07 as speed increases. In contrast, the sunfish pectoral fin generates a single vortex ring per fin beat at low swimming speeds and a pair of linked vortex rings (with one ring only partially complete and attached to the body) at maximal labriform speeds. Across a biologically relevant range of swimming speeds, bluegill sunfish generate relatively large lateral forces with the paired fins: the ratio of lateral to downstream force remains at or above 1.0 at all speeds. By increasing wake momentum and by orienting this momentum in a direction more favorable for thrust than for lateral force, black surfperch are able

  6. Locomotor function of the dorsal fin in teleost fishes: experimental analysis of wake forces in sunfish.

    PubMed

    Drucker, E G; Lauder, G V

    2001-09-01

    A key evolutionary transformation of the locomotor system of ray-finned fishes is the morphological elaboration of the dorsal fin. Within Teleostei, the dorsal fin primitively is a single midline structure supported by soft, flexible fin rays. In its derived condition, the fin is made up of two anatomically distinct portions: an anterior section supported by spines, and a posterior section that is soft-rayed. We have a very limited understanding of the functional significance of this evolutionary variation in dorsal fin design. To initiate empirical hydrodynamic study of dorsal fin function in teleost fishes, we analyzed the wake created by the soft dorsal fin of bluegill sunfish (Lepomis macrochirus) during both steady swimming and unsteady turning maneuvers. Digital particle image velocimetry was used to visualize wake structures and to calculate in vivo locomotor forces. Study of the vortices generated simultaneously by the soft dorsal and caudal fins during locomotion allowed experimental characterization of median-fin wake interactions. During high-speed swimming (i.e. above the gait transition from pectoral- to median-fin locomotion), the soft dorsal fin undergoes regular oscillatory motion which, in comparison with analogous movement by the tail, is phase-advanced (by 30% of the cycle period) and of lower sweep amplitude (by 1.0 cm). Undulations of the soft dorsal fin during steady swimming at 1.1 bodylength s(-1) generate a reverse von Kármán vortex street wake that contributes 12% of total thrust. During low-speed turns, the soft dorsal fin produces discrete pairs of counterrotating vortices with a central region of high-velocity jet flow. This vortex wake, generated in the latter stage of the turn and posterior to the center of mass of the body, counteracts torque generated earlier in the turn by the anteriorly positioned pectoral fins and thereby corrects the heading of the fish as it begins to translate forward away from the turning stimulus. One

  7. Total mercury concentrations in fillets of bluegill, redear sunfish, largemouth bass, and other fishes from Lake Natoma, Sacramento County, California

    USGS Publications Warehouse

    Saiki, M.K.; Martin, B.A.; May, T.W.; Alpers, C.N.

    2005-01-01

    This study was conducted during September-October 2002 to verify preliminary findings of elevated total mercury concentrations in skinless fillets of sportfishes inhabiting Lake Natoma. Although we measured total mercury concentrations, most mercury in fish flesh occurs in the methylated form. In August 2000, other investigators collected a small number of fish containing mercury concentrations that exceeded 0.30 ??g/g wet weight, the U.S. Environmental Protection Agency (USEPA) tissue residue criterion derived from a reference dose for methylmercury that may cause undesirable neurological abnormalities in human infants exposed in utero when pregnant women consume mercury-contaminated foods. During our study, skinless fillets of bluegill, Lepomis macrochirus, contained as much as 0.19 ??g Hg/g wet weight (1.06 ??g Hg/g dry weight); redear sunfish, L. microlophus, contained as much as 0.39 ??g Hg/g wetweight (1.99 ??g Hg/g dry weight); and largemouth bass, Micropterus salmoides, contained as much as 0.86 ??g Hg/g wet weight (3.85 ??g Hg/g dry weight). Maximum concentrations of mercury in other fish species varied from 0.097 ??g/g wet weight (0.537 ??g/g dry weight) in rainbow trout, Oncorhynchus mykiss, to 0.56 ??g/g wet weight (3.07 ??g/g dry weight) in white catfish, Ameiurus catus. Altogether, 1 of 20 redear sunfish, 14 of 61 largemouth bass, 1 of 1 brown builhead, A. nebulosus, 2 of 3 spotted bass, M. punctulatus, and 1 of 1 white catfish exceeded the USEPA fish tissue methylmercury residue criterion. Only bluegill and largemouth bass exhibited significant correlations between fish total length (TL), weight, and age, and total mercury concentration in fillets. Judging from a best-fit power-curve equation, largemouth bass measuring 273 mm TL (roughly 292g) or larger are estimated to contain total mercury concentrations in their fillets that exceed the USEPA fish tissue methylmercury criterion. These results confirmed that some fish species inhabiting Lake Natoma

  8. Potential Human Health Risk by Metal(loid)s, 234,238U and 210Po due to Consumption of Fish from the “Luis L. Leon” Reservoir (Northern México)

    PubMed Central

    Luna-Porres, Mayra Y.; Rodríguez-Villa, Marco A.; Herrera-Peraza, Eduardo F.; Renteria-Villalobos, Marusia; Montero-Cabrera, María E.

    2014-01-01

    Concentrations of As, Cu, Fe, Hg, Pb and Zn and activity concentrations from 234,238U and 210Po in water, fillet, liver and gills were determined in three stocked fish species from the Luis L. Leon reservoir, located in Northern Mexico. The considered species were Lepomis cyanellus, Cyprinus carpio and Ictalurus furcatus. 238U and 234U activity concentration (AC) in fillet samples showed values of 0.007–0.014 and 0.01–0.02 Bq∙kg−1 wet weight (ww), respectively. Liver samples for L. cyanellus, C. carpio and I. furcatus present 210Po AC of 1.16–3.26, 0.70–1.13 and 0.93–1.37 Bq∙kg−1 ww. Arsenic, mercury and lead concentration intervals in fillet samples were 0.13–0.39, 0.005–0.126 and 0.009–0.08 mg∙kg−1 ww, respectively, while in gill samples they were 0.11–0.43, 0.002–0.039 and 0.02–0.26 mg∙kg−1 ww. The elemental Bioaccumulation Factor (BAF) for fish tissues with respect to their concentrations in water was determined. L. cyanellus showed the highest BAF values for As and total U, being BAFAs = 37 and 40 L∙kg−1 in fillet and gills, respectively, and BAFU total = 1.5 L∙kg−1 in fillet. I. furcatus showed the highest BAF values for Hg and Pb, being BAFHg = 40 and 13 L∙kg−1 in fillet and gills, and BAFPb = 6.5 and 22 L∙kg−1 in fillet and gills, respectively. Some metal(loid) concentrations are slightly higher than European regulations for fish fillets. The difference in concentrations of metal(loid)s in fillet among the studied species is probably due to their differences in diet and habitat. PMID:24968208

  9. Influence of metal(loid) bioaccumulation and maternal transfer on embryo-larval development in fish exposed to a major coal ash spill.

    PubMed

    Greeley, Mark S; Adams, S Marshall; Elmore, Logan R; McCracken, Mary K

    2016-04-01

    In December 2008, an earthen retaining wall at the Tennessee Valley Authority (TVA) Kingston Fossil Fuel Plant failed and released 4.1 millionm(3) of coal ash to rivers flowing into Watts Bar Reservoir in east Tennessee, United States (U.S.). As part of a comprehensive effort to evaluate the risks to aquatic resources from this spill - the largest in U.S. history - we compared bioaccumulation and maternal transfer of selenium (Se), arsenic (As), and mercury (Hg) in adult redear sunfish (Lepomis macrolophus), collected two years after the spill from both coal-ash exposed and non-exposed areas of the Emory and Clinch Rivers, with the success of embryo-larval development in their offspring. Whole body and ovary concentrations of Se in female sunfish at three study sites downstream of the spill were significantly elevated (site means=4.9-5.3 and 6.7-9.0mg/kg d.w. whole body and ovary concentrations, respectively) compared with concentrations in fish from reference sites upstream of the spill site (2.2-3.2mg/kg d.w. for whole bodies and 3.6-4.8mg/kg d.w. for ovaries). However, Se concentrations in coal ash-exposed areas remain below proposed U.S. Environmental Protection Agency (USEPA) criteria for the protection of aquatic life. Site-to-site variation in fish concentrations of As and Hg were not well-correlated with ash-exposure, reflecting the multiple sources of these metal(loid)s in the affected watersheds. In 7-day laboratory tests of embryos and larvae derived from in vitro crosses of eggs and sperm from these field-collected sunfish, fertilization success, hatching success, embryo-larval survival, and incidences of developmental abnormalities did not differ significantly between ash-exposed and non-exposed fish. Furthermore, these developmental endpoints were not correlated with whole body or ovary concentrations of Se, As, or Hg in the maternal fish, or with fish size, ovary weight, or gonadal-somatic indices. Results from this and related studies associated

  10. Escaping Flatland: three-dimensional kinematics and hydrodynamics of median fins in fishes.

    PubMed

    Tytell, Eric D; Standen, Emily M; Lauder, George V

    2008-01-01

    Fish swimming has often been simplified into the motions of a two-dimensional slice through the horizontal midline, as though fishes live in a flat world devoid of a third dimension. While fish bodies do undulate primarily horizontally, this motion has important three-dimensional components, and fish fins can move in a complex three-dimensional manner. Recent results suggest that an understanding of the three-dimensional body shape and fin motions is vital for explaining the mechanics of swimming, and that two-dimensional representations of fish locomotion are misleading. In this study, we first examine axial swimming from the two-dimensional viewpoint, detailing the limitations of this view. Then we present data on the kinematics and hydrodynamics of the dorsal fin, the anal fin and the caudal fin during steady swimming and maneuvering in brook trout, Salvelinus fontinalis, bluegill sunfish, Lepomis macrochirus, and yellow perch, Perca flavescens. These fishes actively move the dorsal and anal fins during swimming, resulting in curvature along both anterio-posterior and dorso-ventral axes. The momentum imparted to the fluid by these fins comprises a substantial portion of total swimming force, adding to thrust and contributing to roll stability. While swimming, the caudal fin also actively curves dorso-ventrally, producing vortices separately from both its upper and lower lobes. This functional separation of the lobes may allow additional control of three-dimensional orientation, but probably reduces swimming efficiency. In contrast, fish may boost the caudal fin's efficiency by taking advantage of the flow from the dorsal and anal fins as it interacts with the flow around the caudal fin itself. During maneuvering, fish readily use their fins outside of the normal planes of motion. For example, the dorsal fin can flick laterally, orienting its surface perpendicular to the body, to help in turning and braking. These data demonstrate that, while fish do move

  11. Water-quality models to assess algal community dynamics, water quality, and fish habitat suitability for two agricultural land-use dominated lakes in Minnesota, 2014

    USGS Publications Warehouse

    Smith, Erik A.; Kiesling, Richard L.; Ziegeweid, Jeffrey R.

    2017-07-20

    proportion of good-growth habitat and a sustained period of optimal growth habitat in the summer, without any periods of lethal oxythermal habitat. For Madison and Pearl Lakes, examples of important cool-water fish, particularly game fish, include northern pike (Esox lucius), walleye (Sander vitreus), and black crappie (Pomoxis nigromaculatus); examples of important warm-water fish include bluegill (Lepomis macrochirus), largemouth bass (Micropterus salmoides), and smallmouth bass (Micropterus dolomieu). Sensitivity analyses were completed to understand lake response effects through the use of controlled departures on certain calibrated model parameters and input nutrient loads. These sensitivity analyses also operated as land-use change scenarios because alterations in agricultural practices, for example, could potentially increase or decrease nutrient loads.

  12. Tissue-specific HSP70 levels and reproductive physiological responses in fishes inhabiting a metal-contaminated creek.

    PubMed

    Yoo, J L; Janz, D M

    2003-07-01

    The 70-kDa stress protein family (HSP70) plays important roles in a variety of physiological processes, including protein chaperoning, protection against apoptosis, steroidogenesis, and general cellular stress responses in vertebrate organisms, and has also been proposed as a biochemical marker of environmental stress, such as toxicant exposure. The objectives of this study were to determine HSP70 protein expression in head kidney, liver, gill, and ovarian tissues and to examine reproductive physiological responses in female fishes exposed chronically to sublethal metal concentrations. Female black bullhead (Ameiurus melas) and bluegill sunfish (Lepomis macrochirus) were collected from Tar Creek, Oklahoma (flowing through the Tri-State mining district) and from a nearby reference creek (Lytle Creek) during spring (prespawning; 26.5 +/- 0.95 degrees C water temperature) and winter (ovarian recrudescence; 4.8 +/- 0.80 degrees C water temperature). Aqueous (dissolved and suspended) concentrations of Cd and Zn and liver concentrations of Cd and Zn in both fish species were significantly greater at Tar Creek compared to Lytle Creek. HSP70 expression was consistently elevated in the head kidney of both fish species collected at Tar Creek in comparison to fish collected from the reference creek. In contrast, no consistent differences were observed in HSP70 expression in liver, gill, or ovarian tissues between sites. Significant seasonal differences were observed in expression of HSP70 in gill tissue of both species, in ovarian and liver tissue of bluegill sunfish and in head kidney of black bullhead. Serum testosterone concentration was significantly reduced in sunfish collected from Tar Creek during winter. Gonadosomatic and hepatosomatic indices were significantly lower in black bullhead collected from Tar Creek during spring, and condition factors were lower in black bullhead collected from Tar Creek during both spring and winter. There was no significant difference in

  13. Direct and indirect effects of multiple enemies on water strider mating dynamics.

    PubMed

    Sih, Andrew; Krupa, James J

    1996-01-01

    Previous studies have shown that green sunfish, Lepomis cyanellus, have strong effects on the activity, habitat use, social interactions and mating dynamics of a stream-dwelling water strider, Aquarius remigis (family Gerridae, hence, gerrids). In nature, however, stream pools often contain not just sunfish and water striders, but also smaller fish such as minnows. Here, we used factorial experiments in seminatural streams to document the direct and indirect effects of sunfish and fathead minnows, Pimephales promelas, on water strider survival and behavior. Sunfish, minnows and gerrids all consume surface prey (here, crickets); thus these three species are potential food competitors. Sunfish eat minnows. Accordingly, the presence of sunfish caused minnows to increase their schooling behavior and shift their activity from the surface toward the bottom substrate. The presence of sunfish was also associated with an increase in the number of missing gerrids, whereas minnows caused relatively little gerrid disappearance. Most interestingly, the presence of minnows decreased the effect of sunfish on gerrid disappearance rates; that is, minnows apparently had an indirect positive effect on water strider survival. We suggest that this indirect positive effect reflects the fact that minnows are alternative prey for sunfish. The effects of sunfish and minnows on gerrid mortality explained the influence of these fish on gerrid behavior. Sunfish caused decreases in male gerrid activity, female availability, mating activity, mating frequency and mating duration. Larger males had a mating advantage over smaller males only in pools with sunfish and no minnows. Sunfish also caused a borderline significant decrease in the large female mating advantage. These results were all observed in previous studies and can be viewed as adaptive responses to predation risk. These patterns were not consistent with the expected effects of sunfish as food competitors with water striders. In

  14. The Release Rate of Environmental DNA from Juvenile and Adult Fish

    PubMed Central

    Maruyama, Atsushi; Nakamura, Keisuke; Yamanaka, Hiroki; Kondoh, Michio; Minamoto, Toshifumi

    2014-01-01

    The environmental DNA (eDNA) technique is expected to become a powerful, non-invasive tool for estimating the distribution and biomass of organisms. This technique was recently shown to be applicable to aquatic vertebrates by collecting extraorganismal DNA floating in the water or absorbed onto suspended particles. However, basic information on eDNA release rate is lacking, despite it being essential for practical applications. In this series of experiments with bluegill sunfish (Lepomis macrochirus), we examined the effect of fish developmental stage on eDNA release rate. eDNA concentration reached equilibrium 3 days after the individual fish were introduced into the separate containers, enabling calculation of the eDNA release rate (copies h−1) from individual fish on the assumption that the number of eDNA released from the fish per unit time equals total degradation in the container (copies h−1). The eDNA release rate was 3–4 times higher in the adult (body weight: 30–75 g) than in the juvenile group (0.5–2.0 g). Such positive relationship between fish size and eDNA release rate support the possibility of biomass rather than density estimation using eDNA techniques. However, the eDNA release rate per fish body weight (copies h−1 g−1) was slightly higher in the juvenile than the adult group, which is likely because of the ontogenetic reduction in metabolic activity. Therefore, quantitative eDNA data should be carefully interpreted to avoid overestimating biomass when the population is dominated by juveniles, because the age structure of the focal population is often variable and unseen in the field. eDNA degradation rates (copies l−1 h−1), calculated by curve fitting of time-dependent changes in eDNA concentrations after fish removal, were 5.1–15.9% per hour (half-life: 6.3 h). This suggests that quantitative eDNA data should be corrected using a degradation curve attained in the target field. PMID:25479160

  15. Identifying the Effects on Fish of Changes in Water Pressure during Turbine Passage

    SciTech Connect

    Becker, James M.; Abernethy, Cary S.; Dauble, Dennis D.

    2003-09-01

    Migratory and resident fish in the Columbia River are exposed to stresses associated with hydroelectric power production, including pressure changes during turbine passage and dissolved gas supersaturation. We investigated the responses of fall Chinook salmon (Oncorhynchus tshawytscha), rainbow trout (Oncorhynchus mykiss), and bluegill sunfish (Lepomis macrochirus) to these two stresses, singly and in combination, in the laboratory. Fish were exposed to total dissolved gas levels of 100%, 120%, or 135% of saturation while being held at either surface or 30 ft of pressure. Some of these fish were then subjected to decreases in pressure simulating passage through a Kaplan turbine under “worst case” (to 0.1 atmospheres) or more “fish friendly” (to 0.5 atmospheres) scenarios. Surface- and depth-acclimated Chinook salmon and bluegill, with no exposure to dissolved gas above ambient levels, were subjected to decreases in pressure simulating passage through a bulb turbine under “worst case” (to 0.68 atmospheres) or more “fish friendly” (to 1.0 atmospheres) scenarios. Bluegill, the most pressure-sensitive among the three species, incurred injuries that ranged from mild (internal hemorrhaging) (bulb turbine) to death (Kaplan turbine). For each type of turbine passage, bluegill acclimated to 30 ft depth and subjected to the more severe pressure nadir were more susceptible to injury/death. However, even control bluegill (i.e., not subjected to simulated turbine passage) experienced mild to moderate injury from rapidly ascending from 30 ft of pressure to surface pressure. The dissolved gas level had only a small additive effect on the injury/death rate of bluegill subjected to simulated Kaplan turbine passage. Thus, while physoclistous fish, such as bluegill, appear to be susceptible to injury from any rapid pressure decrease, those that are most severe (e.g., Kaplan turbine passage) are likely to be most injurious. Chinook salmon and rainbow trout were much

  16. Angler effort and catch within a spatially complex system of small lakes.

    USGS Publications Warehouse

    Pope, Kevin L.; Chizinski, Christopher J.; Martin, Dustin R.; Barada, Tony J.; Schuckman, Jeffrey J.

    2014-01-01

    Spatial layout of waterbodies and waterbody size can affect a creel clerk’s ability to intercept anglers for interviews and to accurately count anglers, which will affect the accuracy and precision of estimates of effort and catch. This study aimed to quantify angling effort and catch across a spatially complex system of 19 small (<100 ha) lakes, the Fremont lakes. Total (±SE) angling effort (hours) on individual lakes ranged from 0 (0) to 7,137 (305). Bank anglers utilized 18 of the 19 lakes, and their mean (±SE) trip lengths (hours) ranged from 0.80 (0.31) to 7.75 (6.75), depending on the waterbody. In contrast, boat anglers utilized 14 of the 19 lakes, and their trip lengths ranged from 1.39 (0.24) to 4.25 (0.71), depending on the waterbody. The most sought fishes, as indexed by number of lakes on which effort was exerted, were anything (17 of 19 lakes), largemouth bassMicropterus salmoides (15 of 19 lakes), and channel catfish Ictalurus punctatus (13 of 19 lakes). Bluegill Lepomis machrochirus, crappie Pomoxis spp., and largemouth bass were caught most frequently across the lakes, but catch rates varied considerably by lake. Of the 1,138 parties interviewed, most parties (93%) visited a single lake but there were 77 (7%) parties that indicated that they had visited multiple lakes during a single day. The contingent of parties that visited more than one lake a day were primarily (87%) bank anglers.. The number of lake-to-lake connections made by anglers visiting more than one waterbody during a single day was related to catch rates and total angling effort. The greater resolution that was achieved with a lake specific creel survey at Fremont lakes revealed a system of lakes with a large degree of spatial variation in angler effort and catch that would be missed by a coarser, system-wide survey that did not differentiate individual lakes.

  17. Characterization of alpha-2-macroglobulin from groupers.

    PubMed

    Chuang, Wen-Hsiao; Lee, Kuo-Kau; Liu, Ping-Chung

    2013-08-01

    was performed respectivity. However, no band was detected using plasma from the freshwater fish species and other animal species. Thus, further indicates that the protein structure of α-2-M of Epinephelus spp. was closely related among seawater fish species. In addition the identity of the two subunits was identified using LC/MS/MS which was similar to α-2-M of grass carp (Ctenopharyngodon idella) and bluegill sunfish (Lepomis macrochirus) on the protein hit.

  18. An Assessment of the Bioaccumulation of PCBs and Chloridane Near the U.S. Department of Energy's Kansas City Plant

    SciTech Connect

    Peterson, M.J.

    2003-12-30

    important component of this effort, the fish sampling locations and species collected were essentially the same as in previous studies. In general, locations were chosen upstream and downstream of major KCP outfalls to help evaluate the importance of those outfalls as sources of PCBs. Green sunfish (Lepomis cyanellus) and channel catfish (Ictalurus punctatus) were again the primary species collected.

  19. Uptake and Disposition of Select Pharmaceuticals by Bluegill Exposed at Constant Concentrations in a Flow-Through Aquatic Exposure System.

    PubMed

    Zhao, Jian-Liang; Furlong, Edward T; Schoenfuss, Heiko L; Kolpin, Dana W; Bird, Kyle L; Feifarek, David J; Schwab, Eric A; Ying, Guang-Guo

    2017-03-29

    The increasing use of pharmaceuticals has led to their subsequent input into and release from wastewater treatment plants, with corresponding discharge into surface waters that may subsequently exert adverse effects upon aquatic organisms. Although the distribution of pharmaceuticals in surface water has been extensively studied, the details of uptake, internal distribution, and kinetic processing of pharmaceuticals in exposed fish have received less attention. For this research, we investigated the uptake, disposition, and toxicokinetics of five pharmaceuticals (diclofenac, methocarbamol, rosuvastatin, sulfamethoxazole, and temazepam) in bluegill sunfish (Lepomis macrochirus) exposed to environmentally relevant concentrations (1000-4000 ng L(-1)) in a flow-through exposure system. Temazepam and methocarbamol were consistently detected in bluegill biological samples with the highest concentrations in bile of 4, 940, and 180 ng g(-1), respectively, while sulfamethoxazole, diclofenac, and rosuvastatin were only infrequently detected. Over 30-day exposures, the relative magnitude of mean concentrations of temazepam and methocarbamol in biological samples generally followed the order: bile ≫ gut > liver and brain > muscle, plasma, and gill. Ranges of bioconcentration factors (BCFs) in different biological samples were 0.71-3960 and 0.13-48.6 for temazepam and methocarbamol, respectively. Log BCFs were statistically positively correlated to pH adjusted log Kow (that is, log Dow), with the strongest relations for liver and brain (r(2) = 0.92 and 0.99, respectively), implying that bioconcentration patterns of ionizable pharmaceuticals depend on molecular status, that is, whether a pharmaceutical is un-ionized or ionized at ambient tissue pH. Methocarbamol and temazepam underwent rapid uptake and elimination in bluegill biological compartments with uptake rate constants (Ku) and elimination rate constants (Ke) at 0.0066-0.0330 h(-1) and 0.0075-0.0384 h(-1), respectively