Climate change alters the reproductive phenology and investment of a lacustrine fish, the three-spine stickleback.

Science.gov (United States)

Hovel, Rachel A; Carlson, Stephanie M; Quinn, Thomas P

2017-06-01

High-latitude lakes are particularly sensitive to the effects of global climate change, demonstrating earlier ice breakup, longer ice-free seasons, and increased water temperatures. Such physical changes have implications for diverse life-history traits in taxa across entire lake food webs. Here, we use a five-decade time series from an Alaskan lake to explore effects of climate change on growth and reproduction of a widely distributed lacustrine fish, the three-spine stickleback (Gasterosteus aculeatus). We used multivariate autoregressive state-space (MARSS) models to describe trends in the mean length for multiple size classes and to explore the influence of physical (date of ice breakup, surface water temperature) and biological (density of con- and heterospecifics) factors. As predicted, mean size of age 1 and older fish at the end of the growing season increased across years with earlier ice breakup and warmer temperatures. In contrast, mean size of age 0 fish decreased over time. Overall, lower fish density and warmer water temperatures were associated with larger size for all cohorts. Earlier ice breakup was associated with larger size for age 1 and older fish but, paradoxically, with smaller size of age 0 fish. To explore this latter result, we used mixing models on age 0 size distributions, which revealed an additional cohort in years with early ice breakup, lowering the mean size of age 0 fish. Moreover, early ice breakup was associated with earlier breeding, evidenced by earlier capture of age 0 fish. Our results suggest that early ice breakup altered both timing and frequency of breeding; three-spine stickleback spawned earlier and more often in response to earlier ice breakup date. While previous studies have shown the influence of changing conditions in northern lakes on breeding timing and growth, this is the first to document increased breeding frequency, highlighting another pathway by which climate change can alter the ecology of northern lakes

Gene Expression in the Three-Spined Stickleback (Gasterosteus aculeatus) of Marine and Freshwater Ecotypes.

Science.gov (United States)

Rastorguev, S M; Nedoluzhko, A V; Gruzdeva, N M; Boulygina, E S; Tsygankova, S V; Oshchepkov, D Y; Mazur, A M; Prokhortchouk, E B; Skryabin, K G

2018-01-01

Three-spine stickleback (Gasterosteus aculeatus) is a well-known model organism that is routinely used to explore microevolution processes and speciation, and the number of studies related to this fish has been growing recently. The main reason for the increased interest is the processes of freshwater adaptation taking place in natural populations of this species. Freshwater three-spined stickleback populations form when marine water three-spined sticklebacks fish start spending their entire lifecycle in freshwater lakes and streams. To boot, these freshwater populations acquire novel biological traits during their adaptation to a freshwater environment. The processes taking place in these populations are of great interest to evolutionary biologists. Here, we present differential gene expression profiling in G. aculeatus gills, which was performed in marine and freshwater populations of sticklebacks. In total, 2,982 differentially expressed genes between marine and freshwater populations were discovered. We assumed that differentially expressed genes were distributed not randomly along stickleback chromosomes and that they are regularly observed in the "divergence islands" that are responsible for stickleback freshwater adaptation.

DNA metabarcoding reveals diverse diet of the three-spined stickleback in a coastal ecosystem.

Directory of Open Access Journals (Sweden)

Eglė Jakubavičiūtė

Full Text Available The three-spined stickleback (Gasterosteus aculeatus L., hereafter 'stickleback' is a common mesopredatory fish in marine, coastal and freshwater areas. In large parts of the Baltic Sea, stickleback densities have increased >10-fold during the last decades, and it is now one of the dominating fish species both in terms of biomass and effects on lower trophic levels. Still, relatively little is known about its diet-knowledge which is essential to understand the increasing role sticklebacks play in the ecosystem. Fish diet analyses typically rely on visual identification of stomach contents, a labour-intensive method that is made difficult by prey digestion and requires expert taxonomic knowledge. However, advances in DNA-based metabarcoding methods promise a simultaneous identification of most prey items, even from semi-digested tissue. Here, we studied the diet of stickleback from the western Baltic Sea coast using both DNA metabarcoding and visual analysis of stomach contents. Using the cytochrome oxidase (CO1 marker we identified 120 prey taxa in the diet, belonging to 15 phyla, 83 genera and 84 species. Compared to previous studies, this is an unusually high prey diversity. Chironomids, cladocerans and harpacticoids were dominating prey items. Large sticklebacks were found to feed more on benthic prey, such as amphipods, gastropods and isopods. DNA metabarcoding gave much higher taxonomic resolution (median rank genus than visual analysis (median rank order, and many taxa identified using barcoding could not have been identified visually. However, a few taxa identified by visual inspection were not revealed by barcoding. In summary, our results suggest that the three-spined stickleback feeds on a wide variety of both pelagic and benthic organisms, indicating that the strong increase in stickleback populations may affect many parts of the Baltic Sea coastal ecosystem.

Coexistence of fish species in a large lowland river: food niche partitioning between small-sized percids, cyprinids and sticklebacks in submersed macrophytes.

Science.gov (United States)

Dukowska, Małgorzata; Grzybkowska, Maria

2014-01-01

In the spring and summer of each year, large patches of submersed aquatic macrophytes overgrow the bottom of the alluvial Warta River downstream of a large dam reservoir owing to water management practices. Environmental variables, macroinvertebrates (zoobenthos and epiphytic fauna, zooplankton) and fish abundance and biomass were assessed at this biologically productive habitat to learn intraseasonal dynamics of food types, and their occurrence in the gut contents of small-sized roach, dace, perch, ruffe and three-spined stickleback. Gut fullness coefficient, niche breadth and niche overlap indicated how the fishes coexist in the macrophytes. Chironomidae dominated in the diet of the percids. However, ruffe consumed mostly benthic chironomids, while perch epiphytic chironomids and zooplankton. The diet of dace resembled that in fast flowing water although this rheophilic species occurred at unusual density there. The generalist roach displayed the lowest gut fullness coefficient values and widest niche breadth; consequently, intraspecific rather than interspecific competition decided the fate of roach. Three-spined stickleback differed from the other fishes by consuming epiphytic simuliids and fish eggs. The diet overlap between fishes reaching higher gut fullness coefficient values was rather low when the food associated with the submersed aquatic macrophytes was most abundant; this is congruent with the niche overlap hypothesis that maximal tolerable niche overlap can be higher in less intensely competitive conditions.

Slow fertilization of stickleback eggs: the result of sexual conflict?

Directory of Open Access Journals (Sweden)

Frommen Joachim G

2006-05-01

Full Text Available Abstract Background The fertilization success in sperm competition in externally fertilizing fish depends on number and quality of sperm. The time delay between sequential ejaculations may further influence the outcome of sperm competition. Such a time interval can load the raffle over fertilization if fertilization takes place very fast. Short fertilization times are generally assumed for externally fertilizing fish such as the three-spined stickleback (Gasterosteus aculeatus. In this pair-spawning fish, territorial males often try to steal fertilizations in nests of neighbouring males. This sneaking behaviour causes sperm competition. Sneakers will only get a share of paternity when eggs are not fertilized immediately after sperm release. Contrary to males, females may be interested in multiple paternity of their clutch of eggs. There thus may be a sexual conflict over the speed of fertilization. Results In this study we used two different in vitro fertilization experiments to assess how fast eggs are fertilized in sticklebacks. We show that complete fertilization takes more than 5 min which is atypically long for externally fertilizing fishes. Conclusion This result suggests that the time difference does not imply high costs to the second stickleback male to ejaculate. Slow fertilization (and concomitant prolonged longevity of sperm may be the result of sexual conflict in which females aimed at complete fertilization and/or multiple paternity.

Social learning in fish

OpenAIRE

Atton, Nicola

2010-01-01

Social learning is known to be a common phenomenon in fish, which they utilise under many different contexts, including foraging, mate-choice and migration. Here I review the literature on social learning in fish and present two studies. The first examines the ability of threespined sticklebacks to use social learning in the enhancement of food preferences. The second study examines the ability of both threespined sticklebacks and ninespined sticklebacks to use social learning in the avoidanc...

Niche segregation in two closely related species of stickleback along a physiological axis: explaining multidecadel changes in fish distribution from iron-induced respiratory impairment

NARCIS (Netherlands)

Verberk, W.C.E.P.; Munckhof, van den P.J.J.; Pollux, B.J.A.

2012-01-01

Acute exposure to iron can be lethal to fish, but long-term sublethal impacts of iron require further study. Here we investigated whether the spatial and temporal distribution (1967–2004) of two closely related species of stickleback matched the spatial distribution of iron concentrations in the

Food intake rates of inactive fish are positively linked to boldness in three-spined sticklebacks Gasterosteus aculeatus.

Science.gov (United States)

Jolles, J W; Manica, A; Boogert, N J

2016-04-01

To investigate the link between personality and maximum food intake of inactive individuals, food-deprived three-spined sticklebacks Gasterosteus aculeatus at rest in their home compartments were provided with ad libitum prey items. Bolder individuals ate considerably more than shyer individuals, even after accounting for body size, while sociability did not have an effect. These findings support pace-of-life theory predicting that life-history strategies are linked to boldness. © 2016 The Authors. Journal of Fish Biology published by John Wiley & Sons Ltd on behalf of The Fisheries Society of the British Isles.

Innate immune responses to gut microbiota differ between oceanic and freshwater threespine stickleback populations

Directory of Open Access Journals (Sweden)

Kathryn Milligan-Myhre

2016-02-01

Full Text Available Animal hosts must co-exist with beneficial microbes while simultaneously being able to mount rapid, non-specific, innate immune responses to pathogenic microbes. How this balance is achieved is not fully understood, and disruption of this relationship can lead to disease. Excessive inflammatory responses to resident microbes are characteristic of certain gastrointestinal pathologies such as inflammatory bowel disease (IBD. The immune dysregulation of IBD has complex genetic underpinnings that cannot be fully recapitulated with single-gene-knockout models. A deeper understanding of the genetic regulation of innate immune responses to resident microbes requires the ability to measure immune responses in the presence and absence of the microbiota using vertebrate models with complex genetic variation. Here, we describe a new gnotobiotic vertebrate model to explore the natural genetic variation that contributes to differences in innate immune responses to microbiota. Threespine stickleback, Gasterosteus aculeatus, has been used to study the developmental genetics of complex traits during the repeated evolution from ancestral oceanic to derived freshwater forms. We established methods to rear germ-free stickleback larvae and gnotobiotic animals monoassociated with single bacterial isolates. We characterized the innate immune response of these fish to resident gut microbes by quantifying the neutrophil cells in conventionally reared monoassociated or germ-free stickleback from both oceanic and freshwater populations grown in a common intermediate salinity environment. We found that oceanic and freshwater fish in the wild and in the laboratory share many intestinal microbial community members. However, oceanic fish mount a strong immune response to residential microbiota, whereas freshwater fish frequently do not. A strong innate immune response was uniformly observed across oceanic families, but this response varied among families of freshwater fish

Comparison of catch per unit effort among four minnow trap models in the three-spined stickleback (Gasterosteus aculeatus) fishery.

Science.gov (United States)

Budria, Alexandre; DeFaveri, Jacquelin; Merilä, Juha

2015-12-21

Minnow traps are commonly used in the stickleback (Gasterostidae) fishery, but the potential differences in catch per unit effort (CPUE) among different minnow trap models are little studied. We compared the CPUE of four different minnow trap models in field experiments conducted with three-spined sticklebacks (Gasterosteus aculeatus). Marked (up to 26 fold) differences in median CPUE among different trap models were observed. Metallic uncoated traps yielded the largest CPUE (2.8 fish/h), followed by metallic black nylon-coated traps (1.3 fish/h). Collapsible canvas traps yielded substantially lower CPUEs (black: 0.7 fish/h; red: 0.1 fish/h) than the metallic traps. Laboratory trials further revealed significant differences in escape probabilities among the different trap models. While the differences in escape probability can explain at least part of the differences in CPUE among the trap models (e.g. high escape rate and low CPUE in red canvas traps), discrepancies between model-specific CPUEs and escape rates suggests that variation in entrance rate also contributes to the differences in CPUE. In general, and in accordance with earlier data on nine-spined stickleback (Pungitius pungitius) trapping, the results suggest that uncoated metallic (Gee-type) traps are superior to the other commonly used minnow trap models in stickleback fisheries.

Ecological and evolutionary effects of stickleback on community structure.

Directory of Open Access Journals (Sweden)

Simone Des Roches

Full Text Available Species' ecology and evolution can have strong effects on communities. Both may change concurrently when species colonize a new ecosystem. We know little, however, about the combined effects of ecological and evolutionary change on community structure. We simultaneously examined the effects of top-predator ecology and evolution on freshwater community parameters using recently evolved generalist and specialist ecotypes of three-spine stickleback (Gasterosteus aculeatus. We used a mesocosm experiment to directly examine the effects of ecological (fish presence and density and evolutionary (phenotypic diversity and specialization factors on community structure at lower trophic levels. We evaluated zooplankton biomass and composition, periphyton and phytoplankton chlorophyll-a concentration, and net primary production among treatments containing different densities and diversities of stickleback. Our results showed that both ecological and evolutionary differences in the top-predator affect different aspects of community structure and composition. Community structure, specifically the abundance of organisms at each trophic level, was affected by stickleback presence and density, whereas composition of zooplankton was influenced by stickleback diversity and specialization. Primary productivity, in terms of chlorophyll-a concentration and net primary production was affected by ecological but not evolutionary factors. Our results stress the importance of concurrently evaluating both changes in density and phenotypic diversity on the structure and composition of communities.

In vitro leukocyte response of three-spined sticklebacks (Gasterosteus aculeatus) to helminth parasite antigens.

Science.gov (United States)

Franke, Frederik; Rahn, Anna K; Dittmar, Janine; Erin, Noémie; Rieger, Jennifer K; Haase, David; Samonte-Padilla, Irene E; Lange, Joseph; Jakobsen, Per J; Hermida, Miguel; Fernández, Carlos; Kurtz, Joachim; Bakker, Theo C M; Reusch, Thorsten B H; Kalbe, Martin; Scharsack, Jörn P

2014-01-01

Helminth parasites of teleost fish have evolved strategies to evade and manipulate the immune responses of their hosts. Responsiveness of fish host immunity to helminth antigens may therefore vary depending on the degree of host-parasite counter-adaptation. Generalist parasites, infective for a number of host species, might be unable to adapt optimally to the immune system of a certain host species, while specialist parasites might display high levels of adaptation to a particular host species. The degree of adaptations may further differ between sympatric and allopatric host-parasite combinations. Here, we test these hypotheses by in vitro exposure of head kidney leukocytes from three-spined sticklebacks (Gasterosteus aculeatus) to antigens from parasites with a broad fish host range (Diplostomum pseudospathaceum, Triaenophorus nodulosus), a specific fish parasite of cyprinids (Ligula intestinalis) and parasites highly specific only to a single fish species as second intermediate host (Schistocephalus pungitii, which does not infect G. aculeatus, and Schistocephalus solidus, infecting G. aculeatus). In vitro responses of stickleback leukocytes to S. solidus antigens from six European populations, with S. solidus prevalence from aculeatus to a G. aculeatus-infecting species. Generalist parasites seem to maintain their ability to infect different host species at the costs of relatively higher immunogenicity compared to specialist parasites. In a comparison of sympatric and allopatric combinations of stickleback leukocytes and antigens from S. solidus, magnitudes of in vitro responses were dependent on the prevalence of the parasite in the population of origin, rather than on sympatry. Antigens from Norwegian (prevalence 30-50%) and Spanish (40-66%) S. solidus induced generally higher in vitro responses compared to S. solidus from two German (<1%) populations. Likewise, leukocytes from stickleback populations with a high S. solidus prevalence showed

In situ experiments to assess effects of constraints linked to caging on ecotoxicity biomarkers of the three-spined stickleback (Gasterosteus aculeatus L.).

Science.gov (United States)

Le Guernic, Antoine; Sanchez, Wilfried; Palluel, Olivier; Bado-Nilles, Anne; Turies, Cyril; Chadili, Edith; Cavalié, Isabelle; Adam-Guillermin, Christelle; Porcher, Jean-Marc; Geffard, Alain; Betoulle, Stéphane; Gagnaire, Béatrice

2016-04-01

The aim of this study was to evaluate the effects of caging constraints on multiple fish biomarkers used during ecotoxicological studies (biometric data, immune and antioxidant systems, and energetic status). Two of these constraints were linked to caging: starvation and fish density in cages, and one in relation to the post-caging handling: a short transport. Three in situ experiments were conducted with three-spined sticklebacks (Gasterosteus aculeatus). The first experiment compared the effects of three densities (low, medium, and high). The second experiment compared effects of starvation in fish fed every two days with fish that were not fed. Finally comparisons between sticklebacks which have suffered a short car transport after caging and sticklebacks killed without preliminary transport were made. The lack of food had no effect on fish energetic reserves but negatively affected their condition index and their immune system. Transport and high density induced oxidative stress, defined as an overproduction of reactive oxygen species and a stimulation of the antioxidant system. These two constraints also harmed the leucocyte viability. In order not to have any impact on ecotoxicity biomarkers during in situ experiments, it is preferable to decrease fish density in cages, prevent transport before dissections, and feed fish when the caging lasts more than two weeks.

Perchlorate Exposure Reduces Primordial Germ Cell Number in Female Threespine Stickleback.

Directory of Open Access Journals (Sweden)

Ann M Petersen

Full Text Available Perchlorate is a common aquatic contaminant that has long been known to affect thyroid function in vertebrates, including humans. More recently perchlorate has been shown to affect primordial sexual differentiation in the aquatic model fishes zebrafish and threespine stickleback, but the mechanism has been unclear. Stickleback exposed to perchlorate from fertilization have increased androgen levels in the embryo and disrupted reproductive morphologies as adults, suggesting that perchlorate could disrupt the earliest stages of primordial sexual differentiation when primordial germ cells (PGCs begin to form the gonad. Female stickleback have three to four times the number of PGCs as males during the first weeks of development. We hypothesized that perchlorate exposure affects primordial sexual differentiation by reducing the number of germ cells in the gonad during an important window of stickleback sex determination at 14-18 days post fertilization (dpf. We tested this hypothesis by quantifying the number of PGCs at 16 dpf in control and 100 mg/L perchlorate-treated male and female stickleback. Perchlorate exposure from the time of fertilization resulted in significantly reduced PGC number only in genotypic females, suggesting that the masculinizing effects of perchlorate observed in adult stickleback may result from early changes to the number of PGCs at a time critical for sex determination. To our knowledge, this is the first evidence of a connection between an endocrine disruptor and reduction in PGC number prior to the first meiosis during sex determination. These findings suggest that a mode of action of perchlorate on adult reproductive phenotypes in vertebrates, including humans, such as altered fecundity and sex reversal or intersex gonads, may stem from early changes to germ cell development.

Human-induced eutrophication maintains high parasite prevalence in breeding threespine stickleback populations.

Science.gov (United States)

Budria, Alexandre; Candolin, Ulrika

2015-04-01

Anthropogenic activities are having profound impacts on species interactions, with further consequences for populations and communities. We investigated the influence that anthropogenic eutrophication has on the prevalence of the parasitic tapeworm Schistocephalus solidus in threespine stickleback Gasterosteus aculeatus populations. We caught stickleback from four areas along the coast of Finland, and within each area from one undisturbed and one eutrophied habitat. We found the prevalence of the parasite to be lower in the eutrophied habitats at the start of the breeding season, probably because of fewer piscivorous birds that transmit the parasite. However, while the prevalence of the parasite declined across the season in the undisturbed habitat, it did less so in eutrophied habitats. We discuss different processes that could be behind the differences, such as lower predation rate on infected fish, higher food availability and less dispersal in eutrophied habitats. We found no effect of eutrophication on the proportion of infected stickleback that entered reproductive condition. Together with earlier findings, this suggests that eutrophication increases the proportion of infected stickleback that reproduce. This could promote the evolution of less parasite resistant populations, with potential consequences for the viability of the interacting parties of the host-parasite system.

The three-spinned stickleback (Gasterosteus Aguleatus) as potential biomonitor of 210Po content at two sampling sites of coastal area of the Gulf of Gdansk

International Nuclear Information System (INIS)

Goral, M.; Bojanowski, R.; Szefer, P.

2006-01-01

The aim of presented study was to evaluate the three-spinned stickleback (Gasterosteus Aguleatus) as potential biomonitor of 210 Po content in the vicinity of mouth of the Vistula River and yacht port in Gdynia. The three-spinned stickleback was collected from the above areas. Fish was caught, samples were weighted and their total lengths was measured. The fish age was determined using sagittal otoliths. The 210 Po content was determined by α-spectrometry, following radiochemical separation. The U Mann-Whitney's test showed insignificant differences in 210 Po activity in samples originated from two various geographic regions. Based on the results of both U Mann-Whitney's test Spearman's rank correlations it seems that stickleback could be useful tool for monitoring because of the lack of the sex- and age-dependent influence on polonium concentration in the fish analysed

Classification of threespine stickleback along the benthic-limnetic axis

OpenAIRE

Willacker, James J.; von Hippel, Frank A.; Wilton, Peter R.; Walton, Kelly M.

2010-01-01

Many species of fish display morphological divergence between individuals feeding on macroinvertebrates associated with littoral habitats (benthic morphotypes) and individuals feeding on zooplankton in the limnetic zone (limnetic morphotypes). Threespine stickleback (Gasterosteus aculeatus L.) have diverged along the benthic-limnetic axis into allopatric morphotypes in thousands of populations and into sympatric species pairs in several lakes. However, only a few well known populations have b...

Hook, Line and Infection: A Guide to Culturing Parasites, Establishing Infections and Assessing Immune Responses in the Three-Spined Stickleback.

Science.gov (United States)

Stewart, Alexander; Jackson, Joseph; Barber, Iain; Eizaguirre, Christophe; Paterson, Rachel; van West, Pieter; Williams, Chris; Cable, Joanne

2017-01-01

The three-spined stickleback (Gasterosteus aculeatus) is a model organism with an extremely well-characterized ecology, evolutionary history, behavioural repertoire and parasitology that is coupled with published genomic data. These small temperate zone fish therefore provide an ideal experimental system to study common diseases of coldwater fish, including those of aquacultural importance. However, detailed information on the culture of stickleback parasites, the establishment and maintenance of infections and the quantification of host responses is scattered between primary and grey literature resources, some of which is not readily accessible. Our aim is to lay out a framework of techniques based on our experience to inform new and established laboratories about culture techniques and recent advances in the field. Here, essential knowledge on the biology, capture and laboratory maintenance of sticklebacks, and their commonly studied parasites is drawn together, highlighting recent advances in our understanding of the associated immune responses. In compiling this guide on the maintenance of sticklebacks and a range of common, taxonomically diverse parasites in the laboratory, we aim to engage a broader interdisciplinary community to consider this highly tractable model when addressing pressing questions in evolution, infection and aquaculture. Copyright © 2017 Elsevier Ltd. All rights reserved.

Extensive lineage-specific gene duplication and evolution of the spiggin multi-gene family in stickleback

Directory of Open Access Journals (Sweden)

Nishida Mutsumi

2007-11-01

Full Text Available Abstract Background The threespine stickleback (Gasterosteus aculeatus has a characteristic reproductive mode; mature males build nests using a secreted glue-like protein called spiggin. Although recent studies reported multiple occurrences of genes that encode this glue-like protein spiggin in threespine and ninespine sticklebacks, it is still unclear how many genes compose the spiggin multi-gene family. Results Genome sequence analysis of threespine stickleback showed that there are at least five spiggin genes and two pseudogenes, whereas a single spiggin homolog occurs in the genomes of other fishes. Comparative genome sequence analysis demonstrated that Muc19, a single-copy mucous gene in human and mouse, is an ortholog of spiggin. Phylogenetic and molecular evolutionary analyses of these sequences suggested that an ancestral spiggin gene originated from a member of the mucin gene family as a single gene in the common ancestor of teleosts, and gene duplications of spiggin have occurred in the stickleback lineage. There was inter-population variation in the copy number of spiggin genes and positive selection on some codons, indicating that additional gene duplication/deletion events and adaptive evolution at some amino acid sites may have occurred in each stickleback population. Conclusion A number of spiggin genes exist in the threespine stickleback genome. Our results provide insight into the origin and dynamic evolutionary process of the spiggin multi-gene family in the threespine stickleback lineage. The dramatic evolution of genes for mucous substrates may have contributed to the generation of distinct characteristics such as "bio-glue" in vertebrates.

Strong and consistent natural selection associated with armour reduction in sticklebacks.

Science.gov (United States)

LE Rouzic, Arnaud; Østbye, Kjartan; Klepaker, Tom O; Hansen, Thomas F; Bernatchez, Louis; Schluter, Dolph; Vøllestad, L Asbjørn

2011-06-01

Measuring the strength of natural selection is tremendously important in evolutionary biology, but remains a challenging task. In this work, we analyse the characteristics of selection for a morphological change (lateral-plate reduction) in the threespine stickleback Gasterosteus aculeatus. Adaptation to freshwater, leading with the reduction or loss of the bony lateral armour, has occurred in parallel on numerous occasions in this species. Completely-plated and low-plated sticklebacks were introduced into a pond, and the phenotypic changes were tracked for 20 years. Fish from the last generation were genotyped for the Ectodysplasin-A (Eda) locus, the major gene involved in armour development. We found a strong fitness advantage for the freshwater-type fish (on average, 20% fitness advantage for the freshwater morph, and 92% for the freshwater genotype). The trend is best explained by assuming that this fitness advantage is maximum at the beginning of the invasion and decreases with time. Such fitness differences provide a quantifiable example of rapid selection-driven phenotypic evolution associated with environmental change in a natural population. © 2011 Blackwell Publishing Ltd.

Effects of environmental variation on host-parasite interaction in three-spined sticklebacks (Gasterosteus aculeatus).

Science.gov (United States)

Scharsack, Jörn P; Franke, Frederik; Erin, Noémi I; Kuske, Andra; Büscher, Janine; Stolz, Hendrik; Samonte, Irene E; Kurtz, Joachim; Kalbe, Martin

2016-08-01

Recent research provides accumulating evidence that the evolutionary dynamics of host-parasite adaptations strongly depend on environmental variation. In this context, the three-spined stickleback (Gasterosteus aculeatus) has become an important research model since it is distributed all over the northern hemisphere and lives in very different habitat types, ranging from marine to freshwater, were it is exposed to a huge diversity of parasites. While a majority of studies start from explorations of sticklebacks in the wild, only relatively few investigations have continued under laboratory conditions. Accordingly, it has often been described that sticklebacks differ in parasite burden between habitats, but the underlying co-evolutionary trajectories are often not well understood. With the present review, we give an overview of the most striking examples of stickleback-parasite-environment interactions discovered in the wild and discuss two model parasites which have received some attention in laboratory studies: the eye fluke Diplostomum pseudospathacaeum, for which host fish show habitat-specific levels of resistance, and the tapeworm Schistocephalus solidus, which manipulates immunity and behavior of its stickleback host to its advantage. Finally, we will concentrate on an important environmental variable, namely temperature, which has prominent effects on the activity of the immune system of ectothermic hosts and on parasite growth rates. Copyright © 2016 The Authors. Published by Elsevier GmbH.. All rights reserved.

Altered neurotransmitter function in CO2-exposed stickleback (Gasterosteus aculeatus): a temperate model species for ocean acidification research.

Science.gov (United States)

Lai, Floriana; Jutfelt, Fredrik; Nilsson, Göran E

2015-01-01

Studies on the consequences of ocean acidification for the marine ecosystem have revealed behavioural changes in coral reef fishes exposed to sustained near-future CO2 levels. The changes have been linked to altered function of GABAergic neurotransmitter systems, because the behavioural alterations can be reversed rapidly by treatment with the GABAA receptor antagonist gabazine. Characterization of the molecular mechanisms involved would be greatly aided if these can be examined in a well-characterized model organism with a sequenced genome. It was recently shown that CO2-induced behavioural alterations are not confined to tropical species, but also affect the three-spined stickleback, although an involvement of the GABAA receptor was not examined. Here, we show that loss of lateralization in the stickleback can be restored rapidly and completely by gabazine treatment. This points towards a worrying universality of disturbed GABAA function after high-CO2 exposure in fishes from tropical to temperate marine habitats. Importantly, the stickleback is a model species with a sequenced and annotated genome, which greatly facilitates future studies on underlying molecular mechanisms.

Consistent individual differences in fathering in threespined stickleback Gasterosteus aculeatus

Directory of Open Access Journals (Sweden)

Laura R. STEIN, Alison M. BELL

2012-02-01

Full Text Available There is growing evidence that individual animals show consistent differences in behavior. For example, individual threespined stickleback fish differ in how they react to predators and how aggressive they are during social interactions with conspecifics. A relatively unexplored but potentially important axis of variation is parental behavior. In sticklebacks, fathers provide all of the parental care that is necessary for offspring survival; therefore paternal care is directly tied to fitness. In this study, we assessed whether individual male sticklebacks differ consistently from each other in parental behavior. We recorded visits to nest, total time fanning, and activity levels of 11 individual males every day throughout one clutch, and then allowed the males to breed again. Half of the males were exposed to predation risk while parenting during the first clutch, and the other half of the males experienced predation risk during the second clutch. We detected dramatic temporal changes in parental behaviors over the course of the clutch: for example, total time fanning increased six-fold prior to eggs hatching, then decreased to approximately zero. Despite these temporal changes, males retained their individually-distinctive parenting styles within a clutch that could not be explained by differences in body size or egg mass. Moreover, individual differences in parenting were maintained when males reproduced for a second time. Males that were exposed to simulated predation risk briefly decreased fanning and increased activity levels. Altogether, these results show that individual sticklebacks consistently differ from each other in how they behave as parents [Current Zoology 58 (1: 45–52, 2012].

Consistent individual differences in fathering in threespined stickleback Gasterosteus aculeatus

Institute of Scientific and Technical Information of China (English)

Laura R. STEIN; Alison M. BELL

2012-01-01

There is growing evidence that individual animals show consistent differences in behavior.For example,individual threespined stickleback fish differ in how they react to predators and how aggressive they are during social interactions with conspecifics.A relatively unexplored but potentially important axis of variation is parental behavior.In sticklebacks,fathers provide all of the parental care that is necessary for offspring survival; therefore paternal care is directly tied to fimess.In this study,we assessed whether individual male sticklebacks differ consistently from each other in parental behavior.We recorded visits to nest,total time fanning,and activity levels of 11 individual males every day throughout one clutch,and then allowed the males to breed again.Half of the males were exposed to predation risk while parenting during the fast clutch,and the other half of the males experienced predation risk during the second clutch.We detected dramatic temporal changes in parental behaviors over the course of the clutch:for example,total time fanning increased six-fold prior to eggs hatching,then decreased to approximately zero.Despite these temporal changes,males retained their individually-distinctive parenting styles within a clutch that could not be explained by differences in body size or egg mass.Moreover,individual differences in parenting were maintained when males reproduced for a second time.Males that were exposed to simulated predation risk briefly decreased fanning and increased activity levels.Altogether,these results show that individual sticklebacks consistently differ from each other in how they behave as parents [Current Zoology 58 (1):45-52,2012].

Heritable differences in schooling behavior among threespine stickleback populations revealed by a novel assay.

Directory of Open Access Journals (Sweden)

Abigail R Wark

2011-03-01

Full Text Available Identifying the proximate and ultimate mechanisms of social behavior remains a major goal of behavioral biology. In particular, the complex social interactions mediating schooling behavior have long fascinated biologists, leading to theoretical and empirical investigations that have focused on schooling as a group-level phenomenon. However, methods to examine the behavior of individual fish within a school are needed in order to investigate the mechanisms that underlie both the performance and the evolution of schooling behavior. We have developed a technique to quantify the schooling behavior of an individual in standardized but easily manipulated social circumstances. Using our model school assay, we show that threespine sticklebacks (Gasterosteus aculeatus from alternative habitats differ in behavior when tested in identical social circumstances. Not only do marine sticklebacks show increased association with the model school relative to freshwater benthic sticklebacks, they also display a greater degree of parallel swimming with the models. Taken together, these data indicate that marine sticklebacks exhibit a stronger tendency to school than benthic sticklebacks. We demonstrate that these population-level differences in schooling tendency are heritable and are shared by individuals within a population even when they have experienced mixed-population housing conditions. Finally, we begin to explore the stimuli that elicit schooling behavior in these populations. Our data suggest that the difference in schooling tendency between marine and benthic sticklebacks is accompanied by differential preferences for social vs. non-social and moving vs. stationary shelter options. Our study thus provides novel insights into the evolution of schooling behavior, as well as a new experimental approach to investigate the genetic and neural mechanisms that underlie this complex social behavior.

Sympatric Speciation in Threespine Stickleback: Why Not?

Directory of Open Access Journals (Sweden)

Daniel I. Bolnick

2011-01-01

Full Text Available Numerous theoretical models suggest that sympatric speciation is possible when frequency-dependent interactions such as intraspecific competition drive disruptive selection on a trait that is also subject to assortative mating. Here, I review recent evidence that both conditions are met in lake populations of threespine stickleback (Gasterosteus aculeatus. Nonetheless, sympatric speciation appears to be rare or absent in stickleback. If stickleback qualitatively fit the theoretical requirements for sympatric speciation, why do they not undergo sympatric speciation? I present simulations showing that disruptive selection and assortative mating in stickleback, though present, are too weak to drive speciation. Furthermore, I summarize empirical evidence that disruptive selection in stickleback drives other forms of evolutionary diversification (plasticity, increased trait variance, and sexual dimorphism instead of speciation. In conclusion, core assumptions of sympatric speciation theory seem to be qualitatively reasonable for stickleback, but speciation may nevertheless fail because of (i quantitative mismatches with theory and (ii alternative evolutionary outcomes.

Reverse Evolution of Armor Plates in the Threespine Stickleback

Science.gov (United States)

Kitano, J.; Bolnick, D.I.; Beauchamp, D.A.; Mazur, M.M.; Mori, S.; Nakano, T.; Peichel, C.L.

2008-01-01

Faced with sudden environmental changes, animals must either adapt to novel environments or go extinct. Thus, study of the mechanisms underlying rapid adaptation is crucial not??only for the understanding of natural evolutionary processes but also for the understanding of human-induced evolutionary change, which is an increasingly important problem [1-8]. In the present study, we demonstrate that the frequency of completely plated threespine stickleback fish (Gasterosteus aculeatus) has increased in an urban freshwater lake (Lake Washington, Seattle, Washington) within the last 40 years. This is a dramatic example of "reverse evolution," [9] because the general evolutionary trajectory is toward armor-plate reduction in freshwater sticklebacks [10]. On the basis of our genetic studies and simulations, we propose that the most likely cause of reverse evolution is increased selection for the completely plated morph, which we suggest could result from higher levels of trout predation after a sudden increase in water transparency during the early 1970s. Rapid evolution was facilitated by the existence of standing allelic variation in Ectodysplasin (Eda), the gene that underlies the major plate-morph locus [11]. The Lake Washington stickleback thus provides a novel example of reverse evolution, which is probably caused by a change in allele frequency at the major plate locus in response to a changing predation regime. ?? 2008 Elsevier Ltd. All rights reserved.

Geographic variation in age structure and longevity in the nine-spined stickleback (Pungitius pungitius.

Directory of Open Access Journals (Sweden)

Jacquelin DeFaveri

Full Text Available Variation in age and size of mature nine-spined sticklebacks (Pungitius pungitius within and among 16 Fennoscandian populations were assessed using skeletochronology. The average age of individuals in a given population varied from 1.7 to 4.7 years. Fish from pond populations were on average older than those from lake and marine populations, and females tended to be older than males. Reproduction in marine and lake populations commenced typically at an age of two years, whereas that in ponds at an age of three years. The maximum life span of the fish varied from 3 to 7 years. Mean body size within and among populations increased with increasing age, but the habitat and population differences in body size persisted even after accounting for variation in population age (and sex structure. Hence, the population differences in mean body size are not explainable by age differences alone. As such, much of the pronounced intraspecific variation in population age structure can be attributed to delayed maturation and extended longevity of the pond fish. The results are contrasted and discussed in the context of similar data from the three-spined stickleback (Gasterosteus aculeatus occupying the same geographic area.

Sequence-Based Mapping and Genome Editing Reveal Mutations in Stickleback Hps5 Cause Oculocutaneous Albinism and the casper Phenotype

Directory of Open Access Journals (Sweden)

James C. Hart

2017-09-01

Full Text Available Here, we present and characterize the spontaneous X-linked recessive mutation casper, which causes oculocutaneous albinism in threespine sticklebacks (Gasterosteus aculeatus. In humans, Hermansky-Pudlak syndrome results in pigmentation defects due to disrupted formation of the melanin-containing lysosomal-related organelle (LRO, the melanosome. casper mutants display not only reduced pigmentation of melanosomes in melanophores, but also reductions in the iridescent silver color from iridophores, while the yellow pigmentation from xanthophores appears unaffected. We mapped casper using high-throughput sequencing of genomic DNA from bulked casper mutants to a region of the stickleback X chromosome (chromosome 19 near the stickleback ortholog of Hermansky-Pudlak syndrome 5 (Hps5. casper mutants have an insertion of a single nucleotide in the sixth exon of Hps5, predicted to generate an early frameshift. Genome editing using CRISPR/Cas9 induced lesions in Hps5 and phenocopied the casper mutation. Injecting single or paired Hps5 guide RNAs revealed higher incidences of genomic deletions from paired guide RNAs compared to single gRNAs. Stickleback Hps5 provides a genetic system where a hemizygous locus in XY males and a diploid locus in XX females can be used to generate an easily scored visible phenotype, facilitating quantitative studies of different genome editing approaches. Lastly, we show the ability to better visualize patterns of fluorescent transgenic reporters in Hps5 mutant fish. Thus, Hps5 mutations present an opportunity to study pigmented LROs in the emerging stickleback model system, as well as a tool to aid in assaying genome editing and visualizing enhancer activity in transgenic fish.

Conserved effects of salinity acclimation on thermal tolerance and hsp70 expression in divergent populations of threespine stickleback (Gasterosteus aculeatus).

Science.gov (United States)

Metzger, David C H; Healy, Timothy M; Schulte, Patricia M

2016-10-01

In natural environments, organisms must cope with complex combinations of abiotic stressors. Here, we use threespine stickleback (Gasterosteus aculeatus) to examine how changes in salinity affect tolerance of high temperatures. Threespine stickleback inhabit a range of environments that vary in both salinity and thermal stability making this species an excellent system for investigating interacting stressors. We examined the effects of environmental salinity on maximum thermal tolerance (CTMax) and 70 kDa heat shock protein (hsp70) gene expression using divergent stickleback ecotypes from marine and freshwater habitats. In both ecotypes, the CTMax of fish acclimated to 20 ppt was significantly higher compared to fish acclimated to 2 ppt. The effect of salinity acclimation on the expression of hsp70-1 and hsp70-2 was similar in both the marine and freshwater stickleback ecotype. There were differences in the expression profiles of hsp70-1 and hsp70-2 during heat shock, with hsp70-2 being induced earlier and to a higher level compared to hsp70-1. These data suggest that the two hsp70 isoforms may have functionally different roles in the heat shock response. Lastly, acute salinity challenge coupled with heat shock revealed that the osmoregulatory demands experienced during the heat shock response have a larger effect on the hsp70 expression profile than does the acclimation salinity.

Development of a bioenergetics model for the threespine stickleback Gasterosteus aculeatus

Science.gov (United States)

Hovel, Rachel A.; Beauchamp, David A.; Hansen, Adam G.; Sorel, Mark H.

2016-01-01

The Threespine Stickleback Gasterosteus aculeatus is widely distributed across northern hemisphere ecosystems, has ecological influence as an abundant planktivore, and is commonly used as a model organism, but the species lacks a comprehensive model to describe bioenergetic performance in response to varying environmental or ecological conditions. This study parameterized a bioenergetics model for the Threespine Stickleback using laboratory measurements to determine mass- and temperature-dependent functions for maximum consumption and routine respiration costs. Maximum consumption experiments were conducted across a range of temperatures from 7.5°C to 23.0°C and a range of fish weights from 0.5 to 4.5 g. Respiration experiments were conducted across a range of temperatures from 8°C to 28°C. Model sensitivity was consistent with other comparable models in that the mass-dependent parameters for maximum consumption were the most sensitive. Growth estimates based on the Threespine Stickleback bioenergetics model suggested that 22°C is the optimal temperature for growth when food is not limiting. The bioenergetics model performed well when used to predict independent, paired measures of consumption and growth observed from a separate wild population of Threespine Sticklebacks. Predicted values for consumption and growth (expressed as percent body weight per day) only deviated from observed values by 2.0%. Our model should provide insight into the physiological performance of this species across a range of environmental conditions and be useful for quantifying the trophic impact of this species in food webs containing other ecologically or economically important species.

Digestive enzymes and gut morphometric parameters of threespine stickleback (Gasterosteus aculeatus): Influence of body size and temperature.

Science.gov (United States)

Hani, Younes Mohamed Ismail; Marchand, Adrien; Turies, Cyril; Kerambrun, Elodie; Palluel, Olivier; Bado-Nilles, Anne; Beaudouin, Rémy; Porcher, Jean-Marc; Geffard, Alain; Dedourge-Geffard, Odile

2018-01-01

Determining digestive enzyme activity is of potential interest to obtain and understand valuable information about fish digestive physiology, since digestion is an elementary process of fish metabolism. We described for the first time (i) three digestive enzymes: amylase, trypsin and intestinal alkaline phosphatase (IAP), and (ii) three gut morphometric parameters: relative gut length (RGL), relative gut mass (RGM) and Zihler's index (ZI) in threespine stickleback (Gasterosteus aculeatus), and we studied the effect of temperature and body size on these parameters. When mimicking seasonal variation in temperature, body size had no effect on digestive enzyme activity. The highest levels of amylase and trypsin activity were observed at 18°C, while the highest IAP activity was recorded at 20°C. When sticklebacks were exposed to three constant temperatures (16, 18 and 21°C), a temporal effect correlated to fish growth was observed with inverse evolution patterns between amylase activity and the activities of trypsin and IAP. Temperature (in both experiments) had no effect on morphometric parameters. However, a temporal variation was recorded for both RGM (in the second experiment) and ZI (in both experiments), and the later was correlated to fish body mass.

Digestive enzymes and gut morphometric parameters of threespine stickleback (Gasterosteus aculeatus): Influence of body size and temperature

Science.gov (United States)

Marchand, Adrien; Turies, Cyril; Kerambrun, Elodie; Palluel, Olivier; Bado-Nilles, Anne; Beaudouin, Rémy; Porcher, Jean-Marc; Geffard, Alain; Dedourge-Geffard, Odile

2018-01-01

Determining digestive enzyme activity is of potential interest to obtain and understand valuable information about fish digestive physiology, since digestion is an elementary process of fish metabolism. We described for the first time (i) three digestive enzymes: amylase, trypsin and intestinal alkaline phosphatase (IAP), and (ii) three gut morphometric parameters: relative gut length (RGL), relative gut mass (RGM) and Zihler’s index (ZI) in threespine stickleback (Gasterosteus aculeatus), and we studied the effect of temperature and body size on these parameters. When mimicking seasonal variation in temperature, body size had no effect on digestive enzyme activity. The highest levels of amylase and trypsin activity were observed at 18°C, while the highest IAP activity was recorded at 20°C. When sticklebacks were exposed to three constant temperatures (16, 18 and 21°C), a temporal effect correlated to fish growth was observed with inverse evolution patterns between amylase activity and the activities of trypsin and IAP. Temperature (in both experiments) had no effect on morphometric parameters. However, a temporal variation was recorded for both RGM (in the second experiment) and ZI (in both experiments), and the later was correlated to fish body mass. PMID:29614133

Species phylogeny and diversification process of Northeast Asian Pungitius revealed by AFLP and mtDNA markers

DEFF Research Database (Denmark)

Takahashi, Hiroshi; Møller, Peter Rask; Shedko, Sergei V.

2016-01-01

Pungitius is a highly diversified genus of sticklebacks (Gasterosteidae) occurring widely in northern parts of the Northern Hemisphere. Several ecologically and genetically divergent types that are largely isolated reproductively but occasionally hybridize in sympatry have been discovered...... of hybridization and mtDNA introgression among distinct species. Our results highlight that the marginal seas of Northeast Asia played a key role as barriers to or facilitators of gene flow in the evolution of species diversity of Pungitius concentrated in this region...

Classification of threespine stickleback along the benthic-limnetic axis.

Science.gov (United States)

Willacker, James J; von Hippel, Frank A; Wilton, Peter R; Walton, Kelly M

2010-11-01

Many species of fish display morphological divergence between individuals feeding on macroinvertebrates associated with littoral habitats (benthic morphotypes) and individuals feeding on zooplankton in the limnetic zone (limnetic morphotypes). Threespine stickleback (Gasterosteus aculeatus L.) have diverged along the benthic-limnetic axis into allopatric morphotypes in thousands of populations and into sympatric species pairs in several lakes. However, only a few well known populations have been studied because identifying additional populations as either benthic or limnetic requires detailed dietary or observational studies. Here we develop a Fisher's linear discriminant function based on the skull morphology of known benthic and limnetic stickleback populations from the Cook Inlet Basin of Alaska and test the feasibility of using this function to identify other morphologically divergent populations. Benthic and limnetic morphotypes were separable using this technique and of 45 populations classified, three were identified as morphologically extreme (two benthic and one limnetic), nine as moderately divergent (three benthic and six limnetic) and the remaining 33 populations as morphologically intermediate. Classification scores were found to correlate with eye size, the depth profile of lakes, and the presence of invasive northern pike (Esox lucius). This type of classification function provides a means of integrating the complex morphological differences between morphotypes into a single score that reflects the position of a population along the benthic-limnetic axis and can be used to relate that position to other aspects of stickleback biology.

Genetic basis for body size variation between an anadromous and two derived lacustrine populations of threespine stickleback Gasterosteus aculeatus in southwest Alaska.

Science.gov (United States)

Bowles, Ella; Johnston, Rebecca A; Vanderzwan, Stevi L; Rogers, Sean M

2016-02-01

Body size is a highly variable trait among geographically separated populations. Size-assortative reproductive isolation has been linked to recent adaptive radiations of threespine stickleback ( Gasterosteus aculeatus ) into freshwater, but the genetic basis of the commonly found size difference between anadromous and derived lacustrine sticklebacks has not been tested. We studied the genetic basis of size differences between recently diverging stickleback lineages in southwest Alaska using a common environment experiment. We crossed stickleback within one anadromous (Naknek River) and one lake (Pringle Lake) population and between the anadromous and two lake populations (Pringle and JoJo Lakes), and raised them in a salinity of 4-6 ppt. The F1 anadromous and freshwater forms differed significantly in size, whereas hybrids were intermediate or exhibited dominance toward the anadromous form. Additionally, the size of freshwater F1s differed from their wild counterparts, with within-population F1s from Pringle Lake growing larger than their wild counterparts, while there was no size difference between lab-raised and wild anadromous fish. Sexual dimorphism was always present in anadromous fish, but not in freshwater, and not always in the hybrid crosses. These results, along with parallel changes among anadromous and freshwater forms in other regions, suggest that this heritable trait is both plastic and may be under divergent and/or sexual selection.

Utility of sequenced genomes for microsatellite marker development in non-model organisms: a case study of functionally important genes in nine-spined sticklebacks (Pungitius pungitius

Directory of Open Access Journals (Sweden)

Shimada Yukinori

2010-05-01

Full Text Available Abstract Background Identification of genes involved in adaptation and speciation by targeting specific genes of interest has become a plausible strategy also for non-model organisms. We investigated the potential utility of available sequenced fish genomes to develop microsatellite (cf. simple sequence repeat, SSR markers for functionally important genes in nine-spined sticklebacks (Pungitius pungitius, as well as cross-species transferability of SSR primers from three-spined (Gasterosteus aculeatus to nine-spined sticklebacks. In addition, we examined the patterns and degree of SSR conservation between these species using their aligned sequences. Results Cross-species amplification success was lower for SSR markers located in or around functionally important genes (27 out of 158 than for those randomly derived from genomic (35 out of 101 and cDNA (35 out of 87 libraries. Polymorphism was observed at a large proportion (65% of the cross-amplified loci independently of SSR type. To develop SSR markers for functionally important genes in nine-spined sticklebacks, SSR locations were surveyed in or around 67 target genes based on the three-spined stickleback genome and these regions were sequenced with primers designed from conserved sequences in sequenced fish genomes. Out of the 81 SSRs identified in the sequenced regions (44,084 bp, 57 exhibited the same motifs at the same locations as in the three-spined stickleback. Di- and trinucleotide SSRs appeared to be highly conserved whereas mononucleotide SSRs were less so. Species-specific primers were designed to amplify 58 SSRs using the sequences of nine-spined sticklebacks. Conclusions Our results demonstrated that a large proportion of SSRs are conserved in the species that have diverged more than 10 million years ago. Therefore, the three-spined stickleback genome can be used to predict SSR locations in the nine-spined stickleback genome. While cross-species utility of SSR primers is limited due

Waterborne citalopram has anxiolytic effects and increases locomotor activity in the three-spine stickleback (Gasterosteus aculeatus).

Science.gov (United States)

Kellner, M; Porseryd, T; Hallgren, S; Porsch-Hällström, I; Hansen, S H; Olsén, K H

2016-04-01

Citalopram is an antidepressant drug, which acts by inhibiting the re-uptake of serotonin from the synaptic cleft into the pre-synaptic nerve ending. It is one of the most common drugs used in treatment of depression, it is highly lipophilic and frequently found in sewage treatment plant effluents and surface waters around the world. Citalopram and other selective serotonin re-uptake inhibitors have, at concentrations that occur in nature, been shown to have behavioural as well as physiological effects on fish and other animals. This study is the result of several different experiments, intended to analyse different aspects of behavioural effects of chronic citalopram exposure in fish. Our model species the three-spine stickleback is common in the entire northern hemisphere and is considered to be a good environmental sentinel species. Female three-spine sticklebacks were exposed to 0, 1.5 and 15μg/l nominal concentrations of citalopram for 21 days and subjected to the novel tank (NT) diving test. In the NT test, the fish exposed to 1.5μg/l, but not the 15μg/l fish made a significantly higher number of transitions to the upper half and stayed there for significantly longer time than the fish exposed to 0μg/l. The 15μg/l group, however, displayed a significantly lower number of freeze bouts and a shorter total freezing time. The test for locomotor activity included in the NT test showed that fish treated with 1.5 and 15μg/l displayed a significantly higher swimming activity than control fish both 5-7 and 15-17min after the start of the experiment. In the next experiment we compared fish exposed to 1.5μg/l and 0.15μg/l to pure water controls with regard to shoaling intensity and found no effect of treatment. In the final experiment the propensity of fish treated with 1.5μg/l to approach an unknown object and aggressive behaviour was investigated using the Novel Object test and a mirror test, respectively. The exposed fish ventured close to the unknown object

Conspicuous carotenoid-based pelvic spine ornament in three-spined stickleback populations—occurrence and inheritance

Directory of Open Access Journals (Sweden)

CR Amundsen

2015-04-01

Full Text Available Reports on reddish carotenoid-based ornaments in female three-spined sticklebacks (Gasterosteus aculeatus are few, despite the large interest in the species’ behaviour, ornamentation, morphology and evolution. We sampled sticklebacks from 17 sites in north-western Europe in this first extensive study on the occurrence of carotenoid-based female pelvic spines and throat ornaments. The field results showed that females, and males, with reddish spines were found in all 17 populations. Specimens of both sexes with conspicuous red spines were found in several of the sites. The pelvic spines of males were more intensely red compared to the females’ spines, and large specimens were more red than small ones. Fish infected with the tapeworm (Schistocephalus solidus had drabber spines than uninfected fish. Both sexes had red spines both during and after the spawning period, but the intensity of the red colour was more exaggerated during the spawning period. As opposed to pelvic spines, no sign of red colour at the throat was observed in any female from any of the 17 populations. A rearing experiment was carried out to estimate a potential genetic component of the pelvic spine ornament by artificial crossing and rearing of 15 family groups during a 12 months period. The results indicated that the genetic component of the red colour at the spines was low or close to zero. Although reddish pelvic spines seem common in populations of stickleback, the potential adaptive function of the reddish pelvic spines remains largely unexplained.

Timing of Infections in the Threespine Stickleback (Gasterosteus aculeatus) by Schistocephalus solidus in Alaska.

Science.gov (United States)

Heins, D C; Eidam, D M; Baker, J A

2016-04-01

This study provides direct evidence for the timing of infections by Schistocephalus solidus in the threespine stickleback (Gasterosteus aculeatus) of south-central Alaska. Young-of-the-year fish in Cheney Lake were infected during their first summer within a few months after hatching in May-June. Infections appear to continue under ice cover on the lake during the subsequent fall and winter. Few, if any, 1-yr-old fish seemed to be infected for the first time, although 1-yr-old hosts with established parasites apparently acquired additional infections.

Environmental concentrations of an androgenic progestin disrupts the seasonal breeding cycle in male three-spined stickleback (Gasterosteus aculeatus).

Science.gov (United States)

Svensson, Johan; Fick, Jerker; Brandt, Ingvar; Brunström, Björn

2014-02-01

Synthetic steroid hormones from contraceptive pharmaceuticals have become global aquatic contaminants. Progestins, the synthetic analogs to progesterone, are receiving increasing attention as contaminants and have been shown to impair reproduction in fish and amphibians at low ng L(-1) concentrations. Certain progestins, such as levonorgestrel have androgenic properties and seem to be several orders of magnitude more potent in terms of reproductive impairment in fish than non-androgenic progestins and progestagens. We recently reported that levonorgestrel has strong androgenic effects in female three-spined sticklebacks (Gasterosteus aculeatus), including induction of the normally male-specific glue protein spiggin and suppression of vitellogenesis. In light of this we investigated if exposure to levonorgestrel could disrupt the highly androgen-dependent seasonal reproductive cycle in male sticklebacks. Male sticklebacks that were in the final stage of a breeding period were exposed to various concentrations of levonorgestrel for six weeks in winter conditions in terms of light and temperature, after which reproductive status was evaluated from gross morphology, histology and key gene transcript levels. During the experimental period the controls had transitioned from full breeding condition into the non-breeding state, including regression of secondary sex characteristics, cessation of spiggin production in the kidney, and resumption of spermatogenesis in the testes. This is ascribed to the natural drop in plasma androgen levels after breeding. However, in the groups concurrently exposed to levonorgestrel, transition to the non-breeding condition was dose-dependently inhibited. Our results show that levonorgestrel can disrupt the seasonal breeding cycle in male sticklebacks. The fitness costs of such an effect could be detrimental to natural stickleback populations. Some effects occurred at a levonorgestrel concentration of 6.5 ng L(-1), well within the range of

Changes in the parasite communities as one of the potential causes of decline in abundance of the three-spined sticklebacks in the Puck Bay

Directory of Open Access Journals (Sweden)

Jolanta Morozińska-Gogol

2015-07-01

Full Text Available In the past, the Puck Bay was a very important area for freshwater and marine ichthyofauna. Due to anthropogenic degradation of the environment, especially eutrophication, commercially important fish species have lost spawning grounds and their distribution and abundance fell significantly. A sharp increase in the number of Gasterosteus aculeatus was recorded since the mid-seventies of the twentieth century. Sticklebacks had become the dominant species and were distributed evenly in the coastal waters. But now, the numbers of sticklebacks are decreasing. In this paper, the parasite community of the three-spined sticklebacks was studied. The values of parasitological indices are counted and compared with previous data. Possible consequences of the harboured parasites for body condition, fecundity and changes in host behaviour are described. Also the other possible reasons for the current reduction in the number of sticklebacks in the Puck Bay are analyzed.

Can the behaviour of threespine stickleback parasitized with Schistocephalus solidus be replicated by manipulating host physiology?

Science.gov (United States)

Grécias, Lucie; Hébert, François Olivier; Berger, Chloé Suzanne; Barber, Iain; Aubin-Horth, Nadia

2017-01-15

Sticklebacks infected by the parasitic flatworm Schistocephalus solidus show dramatic changes in phenotype, including a loss of species-typical behavioural responses to predators. The timing of host behaviour change coincides with the development of infectivity of the parasite to the final host (a piscivorous bird), making it an ideal model for studying the mechanisms of infection-induced behavioural modification. However, whether the loss of host anti-predator behaviour results from direct manipulation by the parasite, or is a by-product (e.g. host immune response) or side effect of infection (e.g. energetic loss), remains controversial. To understand the physiological mechanisms that generate these behavioural changes, we quantified the behavioural profiles of experimentally infected fish and attempted to replicate these in non-parasitized fish by exposing them to treatments including immunity activation and fasting, or by pharmacologically inhibiting the stress axis. All fish were screened for the following behaviours: activity, water depth preference, sociability, phototaxis, anti-predator response and latency to feed. We were able to change individual behaviours with certain treatments. Our results suggest that the impact of S. solidus on the stickleback might be of a multifactorial nature. The behaviour changes observed in infected fish might result from the combined effects of modifying the serotonergic axis, lack of energy and activation of the immune system. © 2017. Published by The Company of Biologists Ltd.

Convergent evolution of SWS2 opsin facilitates adaptive radiation of threespine stickleback into different light environments.

Directory of Open Access Journals (Sweden)

David A Marques

2017-04-01

Full Text Available Repeated adaptation to a new environment often leads to convergent phenotypic changes whose underlying genetic mechanisms are rarely known. Here, we study adaptation of color vision in threespine stickleback during the repeated postglacial colonization of clearwater and blackwater lakes in the Haida Gwaii archipelago. We use whole genomes from 16 clearwater and 12 blackwater populations, and a selection experiment, in which stickleback were transplanted from a blackwater lake into an uninhabited clearwater pond and resampled after 19 y to test for selection on cone opsin genes. Patterns of haplotype homozygosity, genetic diversity, site frequency spectra, and allele-frequency change support a selective sweep centered on the adjacent blue- and red-light sensitive opsins SWS2 and LWS. The haplotype under selection carries seven amino acid changes in SWS2, including two changes known to cause a red-shift in light absorption, and is favored in blackwater lakes but disfavored in the clearwater habitat of the transplant population. Remarkably, the same red-shifting amino acid changes occurred after the duplication of SWS2 198 million years ago, in the ancestor of most spiny-rayed fish. Two distantly related fish species, bluefin killifish and black bream, express these old paralogs divergently in black- and clearwater habitats, while sticklebacks lost one paralog. Our study thus shows that convergent adaptation to the same environment can involve the same genetic changes on very different evolutionary time scales by reevolving lost mutations and reusing them repeatedly from standing genetic variation.

Sublethal effects of a metal contamination due to uranium mine tailings in the three-spined stickleback (Gasterosteus aculeatus L.). Implication in the susceptibility to a biological stress

International Nuclear Information System (INIS)

Le Guernic, Antoine

2015-01-01

Uranium extraction has resulted in a remobilization of this actinide into mine surrounding ecosystems. Uses of metal salts during mining site rehabilitation, and the natural presence of metals have increased the metal contamination in hydro systems submitted to mine tailings. In situ experiments were conducted in two former French uranium mining sites. Three-spined stickleback caging was used to determine the sublethal effects of this metal mixture on this freshwater fish, as well as its effects on fish susceptibility to a sudden biological stress. This pollution, characterised by higher metal concentrations (especially for uranium), has led to an oxidative stress in sticklebacks visible through several bio-markers, and other effects dependent on the study site. The polymetallic contamination has modified the stickleback responses to the biological stress, by preventing their phagocytic and antioxidant responses. This work has reinforced the interest of the caging technique during environmental studies and that of immuno-markers in a multi-bio-marker approach. (author)

Diclofenac affects kidney histology in the three-spined stickleback (Gasterosteus aculeatus) at low μg/L concentrations.

Science.gov (United States)

Näslund, Johanna; Fick, Jerker; Asker, Noomi; Ekman, Elisabet; Larsson, D G Joakim; Norrgren, Leif

2017-08-01

Diclofenac, a commonly used non-steroidal anti-inflammatory drug, is considered for regulation under the European water framework directive. This is because effects on fish have been reported at concentrations around those regularly found in treated sewage effluents (∼1μg/L). However, a recent publication reports no effects on fish at 320μg/L. In this study, three-spined sticklebacks (Gasterosteus aculeatus) were exposed to 0, 4.6, 22, 82 and 271μg/L diclofenac in flow-through systems for 28days using triplicate aquaria per concentration. At the highest concentration, significant mortalities were observed already after 21days (no mortalities found up to 22μg/L). Histological analysis revealed a significant increase in the proportion of renal hematopoietic tissue (renal hematopoietic hyperplasia) after 28days at the lowest concentration and at all higher concentrations, following a clear dose-response pattern. Skin ulcerations of the jaw were noted by macroscopic observations, primarily at the two highest concentrations. No histological changes were observed in the liver. There was an increase in the relative hepatic mRNA levels of c7 (complement component 7), a gene involved in the innate immune system, at 22μg/L and at all higher concentrations, again following a clear dose-response. The bioconcentration factor was stable across concentrations, but lower than reported for rainbow trout, suggesting lower internal exposure to the drug in the stickleback. In conclusion, this study demonstrates that diclofenac causes histological changes in the three-spined stickleback at low μg/L concentrations, which cause concern for fish populations exposed to treated sewage effluents. Copyright © 2017 Elsevier B.V. All rights reserved.

Divergent Selection and Then What Not: The Conundrum of Missing Reproductive Isolation in Misty Lake and Stream Stickleback

Directory of Open Access Journals (Sweden)

Katja Räsänen

2012-01-01

Full Text Available In ecological speciation, reproductive isolation evolves as a consequence of adaptation to different selective environments. A frequent contributor to this process is the evolution of positive assortative mate choice between ecotypes. We tested this expectation for lake and inlet stream threespine stickleback (Gasterosteus aculeatus from the Misty system (Vancouver Island, Canada, which show strong genetically based adaptive divergence and little genetic exchange in nature. This, and work on other stickleback systems, led us to expect positive assortative mating. Yet, our standard “no-choice” laboratory experiment on common-garden fish revealed no evidence for this—despite divergence in traits typically mediating assortative mating in stickleback. These results remind us that divergent natural selection may not inevitably lead to the evolution of positive assortative mate choice. The apparent lack of strong and symmetric reproductive barriers in this system presents a conundrum: why are such barriers not evident despite strong adaptive divergence and low gene flow in nature?

A method for the automated long-term monitoring of three-spined stickleback Gasterosteus aculeatus shoal dynamics.

Science.gov (United States)

Kleinhappel, T K; Al-Zoubi, A; Al-Diri, B; Burman, O; Dickinson, P; John, L; Wilkinson, A; Pike, T W

2014-04-01

This paper describes and evaluates a flexible, non-invasive tagging system for the automated identification and long-term monitoring of individual three-spined sticklebacks Gasterosteus aculeatus. The system is based on barcoded tags, which can be reliably and robustly detected and decoded to provide information on an individual's identity and location. Because large numbers of fish can be individually tagged, it can be used to monitor individual- and group-level dynamics within fish shoals. © 2014 The Fisheries Society of the British Isles.

Variation in age and size in Fennoscandian three-spined sticklebacks (Gasterosteus aculeatus).

Science.gov (United States)

DeFaveri, Jacquelin; Merilä, Juha

2013-01-01

Average age and maximum life span of breeding adult three-spined sticklebacks (Gasterosteus aculeatus) were determined in eight Fennoscandian localities with the aid of skeletochronology. The average age varied from 1.8 to 3.6 years, and maximum life span from three to six years depending on the locality. On average, fish from marine populations were significantly older than those from freshwater populations, but variation within habitat types was large. We also found significant differences in mean body size among different habitat types and populations, but only the population differences remained significant after accounting for variation due to age effects. These results show that generation length and longevity in three-spined sticklebacks can vary significantly from one locality to another, and that population differences in mean body size cannot be explained as a simple consequence of differences in population age structure. We also describe a nanistic population from northern Finland exhibiting long life span and small body size.

Variation in age and size in Fennoscandian three-spined sticklebacks (Gasterosteus aculeatus.

Directory of Open Access Journals (Sweden)

Jacquelin DeFaveri

Full Text Available Average age and maximum life span of breeding adult three-spined sticklebacks (Gasterosteus aculeatus were determined in eight Fennoscandian localities with the aid of skeletochronology. The average age varied from 1.8 to 3.6 years, and maximum life span from three to six years depending on the locality. On average, fish from marine populations were significantly older than those from freshwater populations, but variation within habitat types was large. We also found significant differences in mean body size among different habitat types and populations, but only the population differences remained significant after accounting for variation due to age effects. These results show that generation length and longevity in three-spined sticklebacks can vary significantly from one locality to another, and that population differences in mean body size cannot be explained as a simple consequence of differences in population age structure. We also describe a nanistic population from northern Finland exhibiting long life span and small body size.

Osmoregulatory physiology and rapid evolution of salinity tolerance in threespine stickleback recently introduced to fresh water

Science.gov (United States)

Divino, Jeffrey N; Monette, Michelle Y.; McCormick, Stephen; Yancey, Paul H.; Flannery, Kyle G.; Bell, Michael A.; Rollins, Jennifer L.; von Hippel, Frank A.; Schultz, Eric T.

2016-01-01

Background: Post-Pleistocene diversification of threespine stickleback in fresh water offers a valuable opportunity to study how changes in environmental salinity shape physiological evolution in fish. In Alaska, the presence of both ancestral oceanic populations and derived landlocked populations, including recent lake introductions, allows us to examine rates and direction of evolution of osmoregulation following halohabitat transition.

No evidence for UV-based nest-site selection in sticklebacks

Directory of Open Access Journals (Sweden)

Bakker Theo CM

2006-11-01

Full Text Available Abstract Background Nests are built in various animal taxa including fish. In systems with exclusive male parental care, the choice of a nest site may be an important component of male fitness. The nest site may influence male attractiveness as a mate, and male, embryo, and juvenile survival probabilities. Reproductively active three-spined stickleback males establish and defend a territory in which they build a nest. Territories can differ remarkably in qualities that influence male and female reproductive success like predation risk or abiotic factors such as dissolved oxygen concentration or lighting conditions. The latter may be important because in sticklebacks the extended visual capability into the ultraviolet (UV wave range plays a role in female mate choice. Males are thus expected to be choosy about the habitat in which they will build their nest. Results We tested nest-site choice in male three-spined sticklebacks with respect to different UV lighting conditions. Reproductively active males were given the simultaneous choice to build their nest either in an UV-rich (UV+ or an UV-lacking (UV- environment. Males exhibited no significant nest-site preferences with respect to UV+ or UV-. However, larger males and also heavier ones completed their nests earlier. Conclusion We found that UV radiation as well as differences in luminance had no influence on nest-site choice in three-spined sticklebacks. Males that built in the UV-rich environment were not different in any trait (body traits and UV reflection traits from males that built in the UV-poor environment. There was a significant effect of standard length and body mass on the time elapsed until nest completion in the UV experiment. The larger and heavier a male, the faster he completed his nest. In the brightness control experiment there was a significant effect only of body mass on the duration of nest completion. Whether nest building preferences with respect to UV lighting

TIT FOR TAT in sticklebacks and the evolution of cooperation

Science.gov (United States)

Milinski, Manfred

1987-01-01

The problems of achieving mutual cooperation can be formalized in a game called the Prisoner's Dilemma in which selfish defection is always more rewarding than cooperation1. If the two protagonists have a certain minimum probability of meeting again a strategy called TIT FOR TAT is very successful2. In TIT FOR TAT the player cooperates on the first move and thereafter does whatever the opponent did on the previous move. I have studied the behaviour of fish when confronting a potential predator, because conflicts can arise within pairs of fish in these circumstances which I argue resemble a series of games of Prisoner's Dilemma. Using a system of mirrors, single three-spined sticklebacks (Gasterosteus aculeatus) approaching a live predator were provided with either a simulated cooperating companion or a simulated defecting one. In both cases the test fish behaved according to TIT FOR TAT supporting the hypothesis that cooperation can evolve among egoists.

Effect of parasitism on the toxicity of cadmium to the three-spined stickleback, Gasterosteus aculeatus L

Energy Technology Data Exchange (ETDEWEB)

Pascoe, D.; Cram, P.

1977-03-25

The toxicity of cadmium to sticklebacks was determined over a wide range of concentrations. The 96 h LC50 was found to be 6.5 mg Cd 1/sup -1/. The shape of the time-concentration curve suggests that cadmium may have two toxic mechanisms. The median period of survival for fish infected with the plerocercoids of the cestode, Schistocephalus solidus, was found to be considerably shorter than for non-parasitized fish. This observation is considered in the light of the known effects of S. solidus on its host.

Habitat-dependent olfactory discrimination in three-spined sticklebacks (Gasterosteus aculeatus).

Science.gov (United States)

Hiermes, Meike; Mehlis, Marion; Rick, Ingolf P; Bakker, Theo C M

2015-07-01

The ability to recognize conspecifics is indispensible for differential treatment of particular individuals in social contexts like grouping behavior. The advantages of grouping are multifarious, and there exist numerous additional benefits of joining aggregations of conspecifics. Recognition is based on different signals and transmitted via multiple channels, among others the olfactory channel. The sensory system or the combination of sensory modalities used in recognition processes is highly dependent on the availability and effectiveness of modalities, which are a function of the environmental conditions. Using F1-generations of six three-spined stickleback (Gasterosteus aculeatus) populations from two habitat types (tea-stained and clear-water lakes) from the Outer Hebrides, Scotland, we investigated whether individuals are able to recognize members of their own population solely based on olfactory cues and whether the habitat type an individual originated from had an influence on its recognition abilities. When given the choice (own vs. foreign population) sticklebacks from tea-stained lakes significantly preferred the odor of their own population, whereas fish from clear-water habitats did not show any preference. Moreover, fish from the two habitat types differed significantly in their recognition abilities, indicating that olfactory communication is better developed when visual signaling is disturbed. Thus, the observed odor preferences appear to be the consequence of different selective constraints and adaptations as a result of the differences in environmental conditions that have acted on the parental generations. These adaptations are likely genetically based as the differences are present in the F1-generation that had been reared under identical laboratory conditions.

Population-specific plasma proteomes of marine and freshwater three-spined sticklebacks (Gasterosteus aculeatus).

Science.gov (United States)

Kültz, Dietmar; Li, Johnathon; Zhang, Xuezhen; Villarreal, Fernando; Pham, Tuan; Paguio, Darlene

2015-12-01

Molecular phenotypes that distinguish resident marine (Bodega Harbor) from landlocked freshwater (FW, Lake Solano) three-spined sticklebacks were revealed by label-free quantitative proteomics. Secreted plasma proteins involved in lipid transport, blood coagulation, proteolysis, plasminogen-activating cascades, extracellular stimulus responses, and immunity are most abundant in this species. Globulins and albumins are much less abundant than in mammalian plasma. Unbiased quantitative proteome profiling identified 45 highly population-specific plasma proteins. Population-specific abundance differences were validated by targeted proteomics based on data-independent acquisition. Gene ontology enrichment analyses and known functions of population-specific plasma proteins indicate enrichment of processes controlling cell adhesion, tissue remodeling, proteolytic processing, and defense signaling in marine sticklebacks. Moreover, fetuin B and leukocyte cell derived chemotaxin 2 are much more abundant in marine fish. These proteins promote bone morphogenesis and likely contribute to population-specific body armor differences. Plasma proteins enriched in FW fish promote translation, heme biosynthesis, and lipid transport, suggesting a greater presence of plasma microparticles. Many prominent population-specific plasma proteins (e.g. apoptosis-associated speck-like protein containing a CARD) lack any homolog of known function or adequate functional characterization. Their functional characterization and the identification of population-specific environmental contexts and selective pressures that cause plasma proteome diversification are future directions emerging from this study. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Acclimation capacity of the three-spined stickleback (Gasterosteus aculeatus, L.) to a sudden biological stress following a polymetallic exposure.

Science.gov (United States)

Le Guernic, Antoine; Sanchez, Wilfried; Palluel, Olivier; Bado-Nilles, Anne; Floriani, Magali; Turies, Cyril; Chadili, Edith; Vedova, Claire Della; Cavalié, Isabelle; Adam-Guillermin, Christelle; Porcher, Jean-Marc; Geffard, Alain; Betoulle, Stéphane; Gagnaire, Béatrice

2016-10-01

To get closer to the environmental reality, ecotoxicological studies should no longer consider the evaluation of a single pollutant, but rather combination of stress and their interaction. The aim of this study was to determine if responses of a fish to a sudden biological stress could be modified by a prior exposure to a chemical stress (a polymetallic contamination). For this purpose, in situ experiment was conducted in three ponds in the Haute-Vienne department (France). One pond was chosen for its high uranium concentration due to uranium mine tailings, and the two other ponds, which were not submitted to these tailings. Three-spined sticklebacks (Gasterosteus aculeatus) were caged in these ponds for 14 days. After this period, fish were submitted to a biological stress, exerted by lipopolysaccharides injection after anesthesia, and were sacrificed 4 days after these injections for multi-biomarkers analyses (leucocyte viability, phagocytic capacity and reactive oxygen species production, antioxidant peptide and enzymes, lipid peroxidation and DNA damage). The pond which received uranium mine tailings had higher metallic concentrations. Without biological stress, sticklebacks caged in this pond presented an oxidative stress, with increasing of reactive oxygen species levels, modification of some parts of the antioxidant system, and lipid peroxidation. Caging in the two most metal-contaminated ponds resulted in an increase of susceptibility of sticklebacks to the biological stress, preventing their phagocytic responses to lipopolysaccharides and modifying their glutathione contents and glutathione-S-transferase activity.

A field reciprocal transplant experiment reveals asymmetric costs of migration between lake and river ecotypes of three-spined sticklebacks (Gasterosteus aculeatus).

Science.gov (United States)

Kaufmann, J; Lenz, T L; Kalbe, M; Milinski, M; Eizaguirre, C

2017-05-01

Theory of local adaptation predicts that nonadapted migrants will suffer increased costs compared to local residents. Ultimately this process can result in the reduction of gene flow and culminate in speciation. Here, we experimentally investigated the relative fitness of migrants in foreign habitats, focusing on diverging lake and river ecotypes of three-spined sticklebacks. A reciprocal transplant experiment performed in the field revealed asymmetric costs of migration: whereas mortality of river fish was increased under lake conditions, lake migrants suffered from reduced growth relative to river residents. Selection against migrants thus involved different traits in each habitat but generally contributed to bidirectional reduction in gene flow. Focusing particularly on the parasitic environments, migrant fish differed from resident fish in the parasite community they harboured. This pattern correlated with both cellular phenotypes of innate immunity as well as with allelic variation at the genes of the major histocompatibility complex. In addition to showing the costs of migration in three-spined sticklebacks, this study highlights the role of asymmetric selection particularly from parasitism in genotype sorting and in the emergence of local adaptation. © 2017 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2017 European Society For Evolutionary Biology.

A test of maternal programming of offspring stress response to predation risk in threespine sticklebacks.

Science.gov (United States)

Mommer, Brett C; Bell, Alison M

2013-10-02

Non-genetic maternal effects are widespread across taxa and challenge our traditional understanding of inheritance. Maternal experience with predators, for example, can have lifelong consequences for offspring traits, including fitness. Previous work in threespine sticklebacks showed that females exposed to simulated predation risk produced eggs with higher cortisol content and offspring with altered anti-predator behavior. However, it is unknown whether this maternal effect is mediated via the offspring glucocorticoid stress response and if it is retained over the entire lifetime of offspring. Therefore, we tested the hypothesis that maternal exposure to simulated predation risk has long-lasting effects on the cortisol response to simulated predation risk in stickleback offspring. We measured circulating concentrations of cortisol before (baseline), 15 min after, and 60 min after exposure to a simulated predation risk. We compared adult offspring of predator-exposed mothers and control mothers in two different social environments (alone or in a group). Relative to baseline, offspring plasma cortisol was highest 15 min after exposure to simulated predation risk and decreased after 60 min. Offspring of predator-exposed mothers differed in the cortisol response to simulated predation risk compared to offspring of control mothers. In general, females had higher cortisol than males, and fish in a group had lower cortisol than fish that were by themselves. The buffering effect of the social environment did not differ between maternal treatments or between males and females. Altogether the results show that while a mother's experience with simulated predation risk might affect the physiological response of her adult offspring to a predator, sex and social isolation have much larger effects on the stress response to predation risk in sticklebacks. Copyright © 2013 Elsevier Inc. All rights reserved.

Genetic basis of sexual dimorphism in the threespine stickleback Gasterosteus aculeatus

Science.gov (United States)

Leinonen, T; Cano, J M; Merilä, J

2011-01-01

Sexual dimorphism (SD) in morphological, behavioural and physiological features is common, but the genetics of SD in the wild has seldom been studied in detail. We investigated the genetic basis of SD in morphological traits of threespine stickleback (Gasterosteus aculeatus) by conducting a large breeding experiment with fish from an ancestral marine population that acts as a source of morphological variation. We also examined the patterns of SD in a set of 38 wild populations from different habitats to investigate the relationship between the genetic architecture of SD of the marine ancestral population in relation to variation within and among natural populations. The results show that genetic architecture in terms of heritabilities, additive genetic variances and covariances (as well as correlations) is very similar in the two sexes in spite of the fact that many of the traits express significant SD. Furthermore, population differences in threespine stickleback body shape and armour SD appear to have evolved despite constraints imposed by genetic architecture. This implies that constraints for the evolution of SD imposed by strong genetic correlations are not as severe and absolute as commonly thought. PMID:20700139

Two developmentally temporal quantitative trait loci underlie convergent evolution of increased branchial bone length in sticklebacks

Science.gov (United States)

Erickson, Priscilla A.; Glazer, Andrew M.; Cleves, Phillip A.; Smith, Alyson S.; Miller, Craig T.

2014-01-01

In convergent evolution, similar phenotypes evolve repeatedly in independent populations, often reflecting adaptation to similar environments. Understanding whether convergent evolution proceeds via similar or different genetic and developmental mechanisms offers insight towards the repeatability and predictability of evolution. Oceanic populations of threespine stickleback fish, Gasterosteus aculeatus, have repeatedly colonized countless freshwater lakes and streams, where new diets lead to morphological adaptations related to feeding. Here, we show that heritable increases in branchial bone length have convergently evolved in two independently derived freshwater stickleback populations. In both populations, an increased bone growth rate in juveniles underlies the convergent adult phenotype, and one population also has a longer cartilage template. Using F2 crosses from these two freshwater populations, we show that two quantitative trait loci (QTL) control branchial bone length at distinct points in development. In both populations, a QTL on chromosome 21 controls bone length throughout juvenile development, and a QTL on chromosome 4 controls bone length only in adults. In addition to these similar developmental profiles, these QTL show similar chromosomal locations in both populations. Our results suggest that sticklebacks have convergently evolved longer branchial bones using similar genetic and developmental programmes in two independently derived populations. PMID:24966315

Sperm quality but not relatedness predicts sperm competition success in threespine sticklebacks (Gasterosteus aculeatus).

Science.gov (United States)

Mehlis, Marion; Rahn, Anna K; Bakker, Theo C M

2015-04-26

Mating between close relatives often leads to a reduction of an individual's fitness, due to an increased expression of deleterious alleles. Thus, in many animal taxa pre- as well as postcopulatory inbreeding avoidance mechanisms have evolved. An increased risk of inbreeding and hence a loss of genetic variation may occur during founder events as in most cases only few individuals establish a new population. The threespine stickleback (Gasterosteus aculeatus) is a small externally fertilizing fish species subject to strong sperm competition. Sticklebacks inhabit both marine and freshwater environments and anadromous populations have repeatedly established new genetically less diverse freshwater populations. Previous studies showed that anadromous sticklebacks strongly suffer from inbreeding depression and when given the choice females prefer to mate with unrelated males. The present study aimed to address whether there exists a postcopulatory inbreeding avoidance mechanism solely based on sperm-egg interactions in sperm competition experiments. We used F1 individuals that originated either from a large, genetically heterogeneous anadromous population or from a small, genetically less diverse freshwater population. For each population, eggs of two different females were in vitro fertilized by the same two males' sperm in a paired study design. In the main experiment one male was the female's full-sib brother and in the control experiment all individuals were unrelated. The results revealed that fertilization success was independent of relatedness in both populations suggesting a general lack of a postcopulatory inbreeding avoidance mechanism. Instead, male quality (i.e. sperm morphology) predicted paternity success during competitive fertilization trials. In sticklebacks, there is no evidence for postcopulatory inbreeding avoidance. Sperm morphology predicted paternity instead, thus sperm quality traits are under strong sexual selection, presumably driven by the

Horizontal transmission of the ectoparasite Gyrodactylus arcuatus (Monogenea: Gyrodactylidae) to the next generation of the three-spined stickleback Gasterosteus aculeatus.

Science.gov (United States)

Lumme, Jaakko; Zietara, Marek S

2018-04-19

In the parthenogenetic monogeneans of the genus Gyrodactylus Nordmann, 1832, the genetic diversity within or between hosts is determined by the relative roles of lateral transmission and clonal propagation. Clonality and limited transmission lead to high-amplitude metapopulation dynamics and strong genetic drift. In Baltic populations of the three-spined stickleback Gasterosteus aculeatus Linnaeus, the local mitochondrial diversity of Gyrodactylus arcuatus Bychowsky, 1933 is very high, and spatial differentiation weak. To understand the transmission dynamics in a single location, the transmission of the parasite from adults to next generation sticklebacks was investigated in a northern Baltic brackish water location. By sequencing 777 nt of cox1, as many as 38 separate mitochondrial haplotypes were identified. In August, the intensity of gyrodactylid infection on adult hosts was high, the haplotype diversity (h) was extreme and differentiation between fish was negligible (total h = 0.926, mean h = 0.938). In October, only 46% of the juvenile sticklebacks carried G. arcuatus. The number of parasites per young fish followed a Poisson distribution 0.92 ± 1.04 (mean ± SD) on October 2, and was clearly overdispersed 2.38 ± 5.00 on October 25. The total haplotype diversity of parasites on juveniles was nearly as high as in adults (h = 0.916), but the mean per fish was only h = 0.364 (F ST = 0.60), due to low intensity of infection and rapid clonal propagation of early arrivals. The initial first come first served advantage of the first gyrodactylid colonisers will be lost during the host adulthood via continuous transmission. Nesting and polygamy are suggested as factors maintaining the high genetic diversity of the parasite population. The transmission dynamics and, consequently, the population structure of Baltic G. arcuatus is fundamentally different from that of G. salaris Malmberg, 1957, on the Baltic salmon Salmo salar Linnaeus.

Social Regulation of Gene Expression in Threespine Sticklebacks.

Directory of Open Access Journals (Sweden)

Anna K Greenwood

Full Text Available Identifying genes that are differentially expressed in response to social interactions is informative for understanding the molecular basis of social behavior. To address this question, we described changes in gene expression as a result of differences in the extent of social interactions. We housed threespine stickleback (Gasterosteus aculeatus females in either group conditions or individually for one week, then measured levels of gene expression in three brain regions using RNA-sequencing. We found that numerous genes in the hindbrain/cerebellum had altered expression in response to group or individual housing. However, relatively few genes were differentially expressed in either the diencephalon or telencephalon. The list of genes upregulated in fish from social groups included many genes related to neural development and cell adhesion as well as genes with functions in sensory signaling, stress, and social and reproductive behavior. The list of genes expressed at higher levels in individually-housed fish included several genes previously identified as regulated by social interactions in other animals. The identified genes are interesting targets for future research on the molecular mechanisms of normal social interactions.

Androgens increase lws opsin expression and red sensitivity in male three-spined sticklebacks.

Directory of Open Access Journals (Sweden)

Yi Ta Shao

Full Text Available Optomotor studies have shown that three-spined sticklebacks (Gasterosteus aculeatus are more sensitive to red during summer than winter, which may be related to the need to detect the red breeding colour of males. This study aimed to determine whether this change of red light sensitivity is specifically related to reproductive physiology. The mRNA levels of opsin genes were examined in the retinae of sexually mature and immature fish, as well as in sham-operated males, castrated control males, or castrated males implanted with androgen 11-ketoandrostenedione (11 KA, maintained under stimulatory (L16:D8 or inhibitory (L8:D16 photoperiods. In both sexes, red-sensitive opsin gene (lws mRNA levels were higher in sexually mature than in immature fish. Under L16:D8, lws mRNA levels were higher in intact than in castrated males, and were up-regulated by 11 KA treatment in castrated males. Moreover, electroretinogram data confirmed that sexual maturation resulted in higher relative red spectral sensitivity. Mature males under L16:D8 were more sensitive to red light than males under L8:D16. Red light sensitivity under L16:D8 was diminished by castration, but increased by 11 KA treatment. Thus, in sexually mature male sticklebacks, androgen is a key factor in enhancing sensitivity to red light via regulation of opsin gene expression. This is the first study to demonstrate that sex hormones can regulate spectral vision sensitivity.

Hepatic transcriptomic and metabolomic responses in the Stickleback (Gasterosteus aculeatus) exposed to ethinyl-estradiol

International Nuclear Information System (INIS)

Katsiadaki, Ioanna; Williams, Tim D.; Ball, Jonathan S.; Bean, Tim P.; Sanders, Matthew B.; Wu Huifeng; Santos, Eduarda M.; Brown, Margaret M.; Baker, Paul; Ortega, Fernando; Falciani, Francesco; Craft, John A.; Tyler, Charles R.; Viant, Mark R.; Chipman, James K.

2010-01-01

An established three-spined stickleback (Gasterosteus aculeatus) cDNA array was expanded to 14,496 probes with the addition of hepatic clones derived from subtractive and normalized libraries from control males and males exposed to model toxicants. Microarrays and one-dimensional 1 H nuclear magnetic resonance (NMR) spectroscopy, together with individual protein and gene biomarkers were employed to investigate the hepatic responses of the stickleback to ethinyl-estradiol (EE 2 ) exposure. Male fish were exposed via the water to EE 2 , including environmentally relevant concentrations (0.1-100 ng/l) for 4 days, and hepatic transcript and metabolite profiles, kidney spiggin protein and serum vitellogenin concentrations were determined in comparison to controls. EE 2 exposure did not significantly affect spiggin concentration but significantly induced serum vitellogenin protein at the threshold concentration of 32 ng/l. 1 H NMR coupled with robust univariate testing revealed only limited changes, but these did support the predicted modulation of the amino acid profile by transcriptomics. Transcriptional induction was found for hepatic vitellogenins and choriogenins as expected, together with a range of other EE 2 -responsive genes. Choriogenins showed the more sensitive responses with statistically significant induction at 10 ng/l. Real-time polymerase chain reaction (PCR) confirmed transcriptional induction of these genes. Phosvitinless vitellogenin C transcripts were highly expressed and represent a major form of the egg yolk precursors, and this is in contrast to other fish species where it is a minor component of vitellogenic transcripts. Differences in inducibility between the vitellogenins and choriogenins appear to be in accordance with the sequential formation of chorion and yolk during oogenesis in fish.

Hepatic transcriptomic and metabolomic responses in the Stickleback (Gasterosteus aculeatus) exposed to ethinyl-estradiol

Energy Technology Data Exchange (ETDEWEB)

Katsiadaki, Ioanna, E-mail: ioanna.katsiadaki@cefas.co.uk [Centre for Environment, Fisheries and Aquaculture Science, Cefas Weymouth Laboratory, Weymouth, Dorset DT4 8UB (United Kingdom); Williams, Tim D. [School of Biosciences, University of Birmingham, Birmingham, B15 2TT (United Kingdom); Ball, Jonathan S. [School of Biosciences, University of Exeter, Exeter, Devon, EX4 4QJ (United Kingdom); Bean, Tim P.; Sanders, Matthew B. [Centre for Environment, Fisheries and Aquaculture Science, Cefas Weymouth Laboratory, Weymouth, Dorset DT4 8UB (United Kingdom); Wu Huifeng [School of Biosciences, University of Birmingham, Birmingham, B15 2TT (United Kingdom); Santos, Eduarda M. [School of Biosciences, University of Exeter, Exeter, Devon, EX4 4QJ (United Kingdom); Brown, Margaret M.; Baker, Paul [School of Biological and Biomedical Sciences, Glasgow Caledonian University, Glasgow, G4 0BA (United Kingdom); Ortega, Fernando; Falciani, Francesco [School of Biosciences, University of Birmingham, Birmingham, B15 2TT (United Kingdom); Craft, John A. [School of Biological and Biomedical Sciences, Glasgow Caledonian University, Glasgow, G4 0BA (United Kingdom); Tyler, Charles R. [School of Biosciences, University of Exeter, Exeter, Devon, EX4 4QJ (United Kingdom); Viant, Mark R.; Chipman, James K. [School of Biosciences, The University of Birmingham, Birmingham, B15 2TT (United Kingdom)

2010-05-05

An established three-spined stickleback (Gasterosteus aculeatus) cDNA array was expanded to 14,496 probes with the addition of hepatic clones derived from subtractive and normalized libraries from control males and males exposed to model toxicants. Microarrays and one-dimensional {sup 1}H nuclear magnetic resonance (NMR) spectroscopy, together with individual protein and gene biomarkers were employed to investigate the hepatic responses of the stickleback to ethinyl-estradiol (EE{sub 2}) exposure. Male fish were exposed via the water to EE{sub 2}, including environmentally relevant concentrations (0.1-100 ng/l) for 4 days, and hepatic transcript and metabolite profiles, kidney spiggin protein and serum vitellogenin concentrations were determined in comparison to controls. EE{sub 2} exposure did not significantly affect spiggin concentration but significantly induced serum vitellogenin protein at the threshold concentration of 32 ng/l. {sup 1}H NMR coupled with robust univariate testing revealed only limited changes, but these did support the predicted modulation of the amino acid profile by transcriptomics. Transcriptional induction was found for hepatic vitellogenins and choriogenins as expected, together with a range of other EE{sub 2}-responsive genes. Choriogenins showed the more sensitive responses with statistically significant induction at 10 ng/l. Real-time polymerase chain reaction (PCR) confirmed transcriptional induction of these genes. Phosvitinless vitellogenin C transcripts were highly expressed and represent a major form of the egg yolk precursors, and this is in contrast to other fish species where it is a minor component of vitellogenic transcripts. Differences in inducibility between the vitellogenins and choriogenins appear to be in accordance with the sequential formation of chorion and yolk during oogenesis in fish.

Gyrodactylus gasterostei a difficult meal to swallow for the three-spined sticklebacks, Gasterosteus aculeatus L.

Science.gov (United States)

Grano-Maldonado, M I

2014-01-01

This study examines the transmission strategies employed by parasites in order to colonize new hosts. Three-spined sticklebacks, Gasterosteus aculeatus L., were challenged with Gyrodactylus gasterostei Gläser, 1974 in a chamber and the colonization of new hosts was observed. Live-video recording indicates that gyrodactylid transmission possibly maximizes the chances of contact with an alternatively feeding response from dead parasitized hosts to predatory stickleback. It is proposed that host scavenge feeding may comprise an additional route for gyrodactylid transmission, although its relative importance with respect to other recognized routes remains uncertain. Although it was clearly demonstrated that G. gasterostei can reside in the mouth of its host, the study revealed that scavenging-feeding upon dead parasitized hosts did not contribute significantly to the level of infection in 3 h and parasite transmission observed on the feeding fish. A series of experimental exposures and scanning electron microscope images suggest that once ingested, the parasites can attach to the lining of the buccal cavity and then migrate to their preferred colonization site on the outer surface of the fish. In addition to the direct contact infection pathway normally associated with many. This study highlights that diagnosticians should be aware of the fact that the oral cavity may act as temporary transmission location for gyrodactylid fauna. © 2014 Wiley Periodicals, Inc.

Small changes in gene expression of targeted osmoregulatory genes when exposing marine and freshwater threespine stickleback (Gasterosteus aculeatus to abrupt salinity transfers.

Directory of Open Access Journals (Sweden)

Annette Taugbøl

Full Text Available Salinity is one of the key factors that affects metabolism, survival and distribution of fish species, as all fish osmoregulate and euryhaline fish maintain osmotic differences between their extracellular fluid and either freshwater or seawater. The threespine stickleback (Gasterosteus aculeatus is a euryhaline species with populations in both marine and freshwater environments, where the physiological and genomic basis for salinity tolerance adaptation is not fully understood. Therefore, our main objective in this study was to investigate gene expression of three targeted osmoregulatory genes (Na+/K+-ATPase (ATPA13, cystic fibrosis transmembrane regulator (CFTR and a voltage gated potassium channel gene (KCNH4 and one stress related heat shock protein gene (HSP70 in gill tissue from marine and freshwater populations when exposed to non-native salinity for periods ranging from five minutes to three weeks. Overall, the targeted genes showed highly plastic expression profiles, in addition the expression of ATP1A3 was slightly higher in saltwater adapted fish and KCNH4 and HSP70 had slightly higher expression in freshwater. As no pronounced changes were observed in the expression profiles of the targeted genes, this indicates that the osmoregulatory apparatuses of both the marine and landlocked freshwater stickleback population have not been environmentally canalized, but are able to respond plastically to abrupt salinity challenges.

Small changes in gene expression of targeted osmoregulatory genes when exposing marine and freshwater threespine stickleback (Gasterosteus aculeatus) to abrupt salinity transfers.

Science.gov (United States)

Taugbøl, Annette; Arntsen, Tina; Ostbye, Kjartan; Vøllestad, Leif Asbjørn

2014-01-01

Salinity is one of the key factors that affects metabolism, survival and distribution of fish species, as all fish osmoregulate and euryhaline fish maintain osmotic differences between their extracellular fluid and either freshwater or seawater. The threespine stickleback (Gasterosteus aculeatus) is a euryhaline species with populations in both marine and freshwater environments, where the physiological and genomic basis for salinity tolerance adaptation is not fully understood. Therefore, our main objective in this study was to investigate gene expression of three targeted osmoregulatory genes (Na+/K+-ATPase (ATPA13), cystic fibrosis transmembrane regulator (CFTR) and a voltage gated potassium channel gene (KCNH4) and one stress related heat shock protein gene (HSP70)) in gill tissue from marine and freshwater populations when exposed to non-native salinity for periods ranging from five minutes to three weeks. Overall, the targeted genes showed highly plastic expression profiles, in addition the expression of ATP1A3 was slightly higher in saltwater adapted fish and KCNH4 and HSP70 had slightly higher expression in freshwater. As no pronounced changes were observed in the expression profiles of the targeted genes, this indicates that the osmoregulatory apparatuses of both the marine and landlocked freshwater stickleback population have not been environmentally canalized, but are able to respond plastically to abrupt salinity challenges.

Divergent Macroparasite Infections in Parapatric Swiss Lake-Stream Pairs of Threespine Stickleback (Gasterosteus aculeatus.

Directory of Open Access Journals (Sweden)

Anssi Karvonen

Full Text Available Spatial heterogeneity in diversity and intensity of parasitism is a typical feature of most host-parasite interactions, but understanding of the evolutionary implications of such variation is limited. One possible outcome of infection heterogeneities is parasite-mediated divergent selection between host populations, ecotypes or species which may facilitate the process of ecological speciation. However, very few studies have described infections in population-pairs along the speciation continuum from low to moderate or high degree of genetic differentiation that would address the possibility of parasite-mediated divergent selection in the early stages of the speciation process. Here we provide an example of divergent parasitism in freshwater fish ecotypes by examining macroparasite infections in threespine stickleback (Gasterosteus aculeatus of four Swiss lake systems each harbouring parapatric lake-stream ecotype pairs. We demonstrate significant differences in infections within and between the pairs that are driven particularly by the parasite taxa transmitted to fish from benthic invertebrates. The magnitude of the differences tended to correlate positively with the extent of neutral genetic differentiation between the parapatric lake and stream populations of stickleback, whereas no such correlation was found among allopatric populations from similar or contrasting habitats. This suggests that genetic differentiation is unrelated to the magnitude of parasite infection contrasts when gene flow is constrained by geographical barriers while in the absence of physical barriers, genetic differentiation and the magnitude of differences in infections tend to be positively correlated.

Divergent Macroparasite Infections in Parapatric Swiss Lake-Stream Pairs of Threespine Stickleback (Gasterosteus aculeatus).

Science.gov (United States)

Karvonen, Anssi; Lucek, Kay; Marques, David A; Seehausen, Ole

2015-01-01

Spatial heterogeneity in diversity and intensity of parasitism is a typical feature of most host-parasite interactions, but understanding of the evolutionary implications of such variation is limited. One possible outcome of infection heterogeneities is parasite-mediated divergent selection between host populations, ecotypes or species which may facilitate the process of ecological speciation. However, very few studies have described infections in population-pairs along the speciation continuum from low to moderate or high degree of genetic differentiation that would address the possibility of parasite-mediated divergent selection in the early stages of the speciation process. Here we provide an example of divergent parasitism in freshwater fish ecotypes by examining macroparasite infections in threespine stickleback (Gasterosteus aculeatus) of four Swiss lake systems each harbouring parapatric lake-stream ecotype pairs. We demonstrate significant differences in infections within and between the pairs that are driven particularly by the parasite taxa transmitted to fish from benthic invertebrates. The magnitude of the differences tended to correlate positively with the extent of neutral genetic differentiation between the parapatric lake and stream populations of stickleback, whereas no such correlation was found among allopatric populations from similar or contrasting habitats. This suggests that genetic differentiation is unrelated to the magnitude of parasite infection contrasts when gene flow is constrained by geographical barriers while in the absence of physical barriers, genetic differentiation and the magnitude of differences in infections tend to be positively correlated.

Lateral plate evolution in the threespine stickleback: getting nowhere fast.

Science.gov (United States)

Bell, M A

2001-01-01

Gasterosteus aculeatus is a small Holarctic fish with marine, anadromous, and freshwater populations. Marine and anadromous populations apparently have changed little in the past 10 million years and exhibit limited geographical variation. In contrast, freshwater isolates have been founded repeatedly by marine and anadromous populations, and post-glacial isolates have undergone extraordinary adaptive radiation. Stickleback traits that have diversified during post-glacial radiation, including the 'lateral plates' (LP), can evolve substantially within decades after colonization of fresh water or when the environment (particularly predation regime) changes. Although highly divergent freshwater isolates of G. aculeatus have existed for at least 10 million years, they have rarely experienced sustained evolutionary divergence leading to formation of widespread, phenotypically distinct species. The paradox of rapid LP evolution without sustained divergence has resulted from selective extinction of highly divergent populations, because they are specialized for conditions in small, isolated habitats that tend to dry up within limited periods. Biological species of G. aculeatus may also evolve within decades, and are also prone to extinction because they are endemic to and specialized for small, ephemeral habitats. The high rate of evolution observed in contemporary threespine stickleback populations may not be unique to this species complex and has important implications for use of post-glacial populations in comparative studies, speciation rate, and discrimination of sympatric and allopatric speciation.

GnRH mRNA levels in male three-spined sticklebacks, Gasterosteus aculeatus, under different reproductive conditions.

Science.gov (United States)

Shao, Yi Ta; Tseng, Yung Che; Chang, Chia-Hao; Yan, Hong Young; Hwang, Pung Pung; Borg, Bertil

2015-02-01

In vertebrates, reproduction is regulated by the brain-pituitary-gonad (BPG) axis, where the gonadotropin-releasing hormone (GnRH) is one of the key components. However, very little is known about the possible role of GnRH in the environmental and feedback control of fish reproduction. To investigate this, full-length gnrh2 (chicken GnRH II) and gnrh3 (salmon GnRH) sequences of male three-spined sticklebacks (Gasterosteus aculeatus), which are clustered with the taxa of the same GnRH type as other Euteleostei, were cloned and annotated. gnrh1 is absent in this species. The mRNA levels of gnrh2 and gnrh3 in the sticklebacks' brain were measured under breeding and post-breeding conditions as well as in castrated and sham-operated breeding fish and castrated/sham-operated fish kept under long-day (LD 16:8) and short-day (LD 8:16) conditions. Fully breeding males had considerably higher mRNA levels of gnrh2 and gnrh3 in the thalamus (Th) and in the telencephalon and preoptic area (T+POA), respectively, than post-breeding males. Sham-operated breeding males have higher gnrh3 mRNA levels than the corresponding castrated males. Moreover, higher gnrh2 mRNA levels in the Th and higher gnrh3 mRNA levels in the T+POA and hypothalamus (HypTh) were also found in long-day sham-operated males than in sham-operated fish kept under an inhibitory short day photoperiod. Nevertheless, gnrh2 and gnrh3 mRNA levels were not up-regulated in castrated males kept under long-day photoperiod, which suggests that positive feedbacks on the brain-pituitary-gonad axis are necessary for this response. Copyright © 2014 Elsevier Inc. All rights reserved.

UV Deprivation Influences Social UV Preference in Juvenile Sticklebacks

Directory of Open Access Journals (Sweden)

Ricarda Modarressie

2015-05-01

Full Text Available Social aggregations occur in many different animal taxa and mainly result from non-random assortment. Investigating factors that shape and maintain the composition of social aggregations are among others a main topic for understanding ecological speciation processes. Aggregation decisions are mediated by olfactory and visual cues, which in many animals are extended into the UV part of the electromagnetic spectrum. Here, we were interested in developmental plasticity of social preferences with respect to UV radiation in aquatic organisms. Specifically, we tested whether different lighting environments with respect to UV wavelengths during early life stages influence the shoaling preference in juvenile threespine sticklebacks (Gasterosteus aculeatus. Family (full-sibling groups were split and reared under UV-lacking (UV- and UV-present (UV+ lighting conditions. Subsequent shoal choice experiments, in which test fish from both rearing conditions could simultaneously choose between a shoal seen behind a UV-blocking (UV- and a shoal seen behind a UV-transmitting (UV+ filter, revealed a significant effect of lighting condition during rearing on association preference. Test fish that had been deprived of UV spent significantly more time near the UV- shoal compared to the test fish reared under full-spectrum lighting conditions. The results are discussed with respect to plasticity of the visual system and environmental lighting conditions.

Inappropriate analysis does not reveal the ecological causes of evolution of stickleback armour: a critique of Spence et al. 2013.

Science.gov (United States)

MacColl, Andrew D C; Aucott, Beth

2014-09-01

In a recent paper in this journal, Spence et al. (2013) sought to identify the ecological causes of morphological evolution in three-spined sticklebacks Gasterosteus aculeatus, by examining phenotypic and environmental variation between populations on the island of North Uist, Scotland. However, by using simple qualitative assessments of phenotype and inappropriate measures of environmental variation, Spence et al. have come to a conclusion that is diametrically opposite to that which we have arrived at in studying the same populations. Our criticisms of their paper are threefold: (1) using a binomial qualitative measure of the variation in stickleback armour ("low" versus "minimal" (i.e., "normal" low-plated freshwater sticklebacks versus spineless and/or plateless fish)) does not represent the full range of phenotypes that can be described by quantitative measures of the individual elements of armour. (2) Their use of unspecified test kits, with a probable accuracy of 4 ppm, may not be accurate in the range of water chemistry on North Uist (1 to 30 ppm calcium). (3) Their qualitative assessment of the abundance of brown trout Salmo trutta as the major predator of sticklebacks does not accurately describe the variation in brown trout abundance that is revealed by catch-per-unit-effort statistics. Repeating Spence et al.'s analysis using our own measurements, we find, in direct contradiction to them, that variation in stickleback bony armour is strongly correlated with variation in trout abundance, and unrelated to variation in the concentration of calcium in the lochs in which they live. Field studies in ecology and evolution seldom address the same question in the same system at the same time, and it is salutary that in this rare instance two such studies arrived at diametrically opposite answers.

Ontogenetic and evolutionary effects of predation and competition on nine-spined stickleback (Pungitius pungitius) body size.

Science.gov (United States)

Välimäki, Kaisa; Herczeg, Gábor

2012-07-01

1. Individual- and population-level variation in body size and growth often correlates with many fitness traits. Predation and food availability are expected to affect body size and growth as important agents of both natural selection and phenotypic plasticity. How differences in predation and food availability affect body size/growth during ontogeny in populations adapted to different predation and competition regimes is rarely studied. 2. Nine-spined stickleback (Pungitius pungitius) populations originating from habitats with varying levels of predation and competition are known to be locally adapted to their respective habitats in terms of body size and growth. Here, we studied how different levels of perceived predation risk and competition during ontogeny affect the reaction norms of body size and growth in (i) marine and pond populations adapted to different levels of predation and competition and (ii) different sexes. We reared nine-spined stickleback in a factorial experiment under two levels of perceived predation risk (present/absent) and competition (high/low food supply). 3. We found divergence in the reaction norms at two levels: (i) predation-adapted marine stickleback had stronger reactions to predatory cues than intraspecific competition-adapted pond stickleback, the latter being more sensitive to available food than the marine fish and (ii) females reacting more strongly to the treatments than males. 4. The repeated, habitat-dependent nature of the differences suggests that natural selection is the agent behind the observed patterns. Our results suggest that genetic adaptation to certain environmental factors also involves an increase in the range of expressible phenotypic plasticity. We found support for this phenomenon at two levels: (i) across populations driven by habitat type and (ii) within populations driven by sex. © 2012 The Authors. Journal of Animal Ecology © 2012 British Ecological Society.

Small-sized euryhaline fish as intermediate hosts of the digenetic trematode Cryptocotyle concavum

Science.gov (United States)

Zander, C. D.; Kollra, H.-G.; Antholz, B.; Meyer, W.; Westphal, D.

1984-03-01

Cercariae of the trematode Cryptocotyle concavum, which encyst in skin and/or kidney of sticklebacks and gobies, were studied in the Schlei Fjord (western Baltic Sea). Mean incidence of dermal cysts was 48 % in Gasterosteus aculeatus and 37 % in Pungitius pungitius. No cysts were found in the kidneys of sticklebacks. While 97 % of Pomatoschistus microps had encysted metacercariae in the kidneys, only 2 % had cysts in the skin. Pomatoschistus minutus, however, showed hardly any cyst infestation of either skin or kidney. In P. microps the intensity of infestation by metacercariae was frequently more than 50 cysts; in contrast, sticklebacks rarely exhibited more than 5 dermal cysts. Infested fish were larger than 10 mm in total length, the incidence rate increasing with growth. Parasitic infestation depends on ambient salinity: C. concavum was not found at salinities below 4 ‰. In contrast to the high incidence in fish, the first hosts — the snails Hydrobia stagnalis and H. neglecta — showed remarkably low infection rates (3 to 5 %). The findings reported are related to the distribution of C. concavum, the mode of life of infested fish, the feeding habits of the final hosts and the infestation of P. microps by other parasites. Evidently, P. microps represents an optimal second host for C. concavum.

Habitat-specific morphological variation among threespine sticklebacks (Gasterosteus aculeatus within a drainage basin.

Directory of Open Access Journals (Sweden)

Mike M Webster

Full Text Available Habitat-specific morphological variation, often corresponding to resource specialization, is well documented in freshwater fishes. In this study we used landmark based morphometric analyses to investigate morphological variation among threespine sticklebacks (Gasterosteus aculeatus L. from four interconnected habitat types within a single lowland drainage basin in eastern England. These included the upper and lower reaches of the river, the estuary, a connected ditch network and a coastal salt marsh. We found significant habitat-specific differences in morphology, with three axes of variation describing differences in orbit diameter, body depth, caudal peduncle shape and pectoral fin positioning as well as variation in relative dorsal and pelvic spine size. Interestingly, the ditch system, an artificial and heavily managed habitat, is populated by sticklebacks with a characteristic morphology, suggesting that human management of habitats can in some circumstances lead to morphological variation among the animals that inhabit them. We discuss the mechanisms that conceivably underlie the observed morphological variation and the further work necessary to identify them. Finally, we consider the implications of habitat-specific body shape variation for the behavioural ecology of this ecologically generalist species.

Habitat-Specific Morphological Variation among Threespine Sticklebacks (Gasterosteus aculeatus) within a Drainage Basin

Science.gov (United States)

Webster, Mike M.; Atton, Nicola; Hart, Paul J. B.; Ward, Ashley J. W.

2011-01-01

Habitat-specific morphological variation, often corresponding to resource specialization, is well documented in freshwater fishes. In this study we used landmark based morphometric analyses to investigate morphological variation among threespine sticklebacks (Gasterosteus aculeatus L.) from four interconnected habitat types within a single lowland drainage basin in eastern England. These included the upper and lower reaches of the river, the estuary, a connected ditch network and a coastal salt marsh. We found significant habitat-specific differences in morphology, with three axes of variation describing differences in orbit diameter, body depth, caudal peduncle shape and pectoral fin positioning as well as variation in relative dorsal and pelvic spine size. Interestingly, the ditch system, an artificial and heavily managed habitat, is populated by sticklebacks with a characteristic morphology, suggesting that human management of habitats can in some circumstances lead to morphological variation among the animals that inhabit them. We discuss the mechanisms that conceivably underlie the observed morphological variation and the further work necessary to identify them. Finally, we consider the implications of habitat-specific body shape variation for the behavioural ecology of this ecologically generalist species. PMID:21698269

Different behaviour-body length correlations in two populations of juvenile three-spined stickleback (Gasterosteus aculeatus).

Science.gov (United States)

De Winter, Gunnar; Martins, Henrique Ramalho; Trovo, Rafael Arnoni; Chapman, Ben B

2016-01-01

Behavioural variation among individuals has received a lot of attention by behavioural ecologists in the past few years. Its causes and consequences are becoming vast areas of research. The origin and maintenance of individual variation in behaviour within and among populations is affected by many facets of the biotic and abiotic environment. Here, two populations of lab-reared juvenile three-spined sticklebacks (Gasterosteus aculeatus) are tested for three behaviours (boldness, exploration, and sociability). Given the identical rearing conditions, the only difference between these populations is the parental habitat. In both populations, correlations between behaviour and body length are found. Interestingly, these differ between the populations. In one population body length was negatively correlated with exploratory behaviour, while in the other one body length correlated negatively with sociability. Considering the identical environment these juvenile fish were exposed to, these findings suggest a potential (epi)genetic foundation for these correlations and shows that, in three-spined sticklebacks, the proximate basis for correlations between body length and behaviour appears quite malleable. Copyright © 2015 Elsevier B.V. All rights reserved.

Early Development of the Threespine Stickleback in Relation to Water pH

Directory of Open Access Journals (Sweden)

Olivier Glippa

2017-12-01

Full Text Available Ocean acidification is a growing environmental problem, and there is a need to investigate how the decreasing pH will affect marine organisms. Here we studied the effects of lowered pH on the growth and development of the threespine stickleback (Gasterosteus aculeatus eggs. Adult fish, collected from the natural environment, were allowed to mate in aquaria and the newly produced eggs were incubated in an experiment. Eggs and larvae from ambient conditions (produced in the laboratory were reared at three different pH concentrations (control: pH 7.8; and reduced pH treatments: pH 7.5 and 7.0 for 21 days in the laboratory. Dissolved oxygen concentration (8.1 ± 0.1 mg l−1 and temperature (18.6 ± 0.02°C were monitored regularly. Then, egg diameter, larval length, weight and survival were measured. There was no relationship between egg diameter and pH or oxygen, but a negative relationship was found with temperature. Survival of larvae was not affected by pH or temperature, whereas dissolved oxygen concentration had a positive effect on number of survivors. The pH did not have a significant effect on the final larval length on day 21, but interacted significantly with dissolved oxygen. Higher temperatures were found to have a positive effect on the final larval length and weight. Larval weight, on the other hand, was not related to pH nor oxygen. Coastal zones are characterized by pH levels that fluctuate due to natural processes, such as upwelling and river runoff. Our results suggest that the threespine stickleback larvae are well adapted to the different pHs tested, and egg development will likely not be affected by decreasing pH, but even slight temperature and oxygen changes can have a great impact on the threespine stickleback development.

Morphological differences between habitats are associated with physiological and behavioural trade-offs in stickleback (Gasterosteus aculeatus).

Science.gov (United States)

Seebacher, Frank; Webster, Mike M; James, Rob S; Tallis, Jason; Ward, Ashley J W

2016-06-01

Local specialization can be advantageous for individuals and may increase the resilience of the species to environmental change. However, there may be trade-offs between morphological responses and physiological performance and behaviour. Our aim was to test whether habitat-specific morphology of stickleback (Gasterosteus aculeatus) interacts with physiological performance and behaviour at different salinities. We rejected the hypothesis that deeper body shape of fish from habitats with high predation pressure led to decreases in locomotor performance. However, there was a trade-off between deeper body shape and muscle quality. Muscle of deeper-bodied fish produced less force than that of shallow-bodied saltmarsh fish. Nonetheless, saltmarsh fish had lower swimming performance, presumably because of lower muscle mass overall coupled with smaller caudal peduncles and larger heads. Saltmarsh fish performed better in saline water (20 ppt) relative to freshwater and relative to fish from freshwater habitats. However, exposure to salinity affected shoaling behaviour of fish from all habitats and shoals moved faster and closer together compared with freshwater. We show that habitat modification can alter phenotypes of native species, but local morphological specialization is associated with trade-offs that may reduce its benefits.

Inheritance of vertebral number in the three-spined stickleback (Gasterosteus aculeatus.

Directory of Open Access Journals (Sweden)

Jussi S Alho

Full Text Available Intraspecific variation in the number of vertebrae is taxonomically widespread, and both genetic and environmental factors are known to contribute to this variation. However, the relative importance of genetic versus environmental influences on variation in vertebral number has seldom been investigated with study designs that minimize bias due to non-additive genetic and maternal influences. We used a paternal half-sib design and animal model analysis to estimate heritability and causal components of variance in vertebral number in three-spined sticklebacks (Gasterosteus aculeatus. We found that both the number of vertebrae (h(2 = 0.36 and body size (h(2 = 0.42 were moderately heritable, whereas the influence of maternal effects was estimated to be negligible. While the number of vertebrae had a positive effect on body size, no evidence for a genetic correlation between body size and vertebral number was detected. However, there was a significant positive environmental correlation between these two traits. Our results support the generalization--in accordance with results from a review of heritability estimates for vertebral number in fish, reptiles and mammals--that the number of vertebrae appears to be moderately to highly heritable in a wide array of species. In the case of the three-spined stickleback, independent evolution of body size and number of vertebrae should be possible given the low genetic correlation between the two traits.

Inheritance of Vertebral Number in the Three-Spined Stickleback (Gasterosteus aculeatus)

Science.gov (United States)

Alho, Jussi S.; Leinonen, Tuomas; Merilä, Juha

2011-01-01

Intraspecific variation in the number of vertebrae is taxonomically widespread, and both genetic and environmental factors are known to contribute to this variation. However, the relative importance of genetic versus environmental influences on variation in vertebral number has seldom been investigated with study designs that minimize bias due to non-additive genetic and maternal influences. We used a paternal half-sib design and animal model analysis to estimate heritability and causal components of variance in vertebral number in three-spined sticklebacks (Gasterosteus aculeatus). We found that both the number of vertebrae (h2 = 0.36) and body size (h2 = 0.42) were moderately heritable, whereas the influence of maternal effects was estimated to be negligible. While the number of vertebrae had a positive effect on body size, no evidence for a genetic correlation between body size and vertebral number was detected. However, there was a significant positive environmental correlation between these two traits. Our results support the generalization-in accordance with results from a review of heritability estimates for vertebral number in fish, reptiles and mammals-that the number of vertebrae appears to be moderately to highly heritable in a wide array of species. In the case of the three-spined stickleback, independent evolution of body size and number of vertebrae should be possible given the low genetic correlation between the two traits. PMID:21603609

A non-invasive method based on head morphology to sex mature three-spined stickleback (Gasterosteus aculeatus L.) in rearing conditions.

Science.gov (United States)

de Kermoysan, Goulwen; Péry, Alexandre R R; Porcher, Jean-Marc; Beaudouin, Rémy

2013-08-01

A mathematical model to distinguish mature female and male three-spined sticklebacks Gasterosteus aculeatus L. 1758 is proposed. This method is based on sexual dimorphism in the head morphology. The discrimination was established on five distances of interest on the head, adjusted by the standard length of fish. The parameters were estimated based on a training set composed of 102 fish with an equilibrium sex ratio and validated on a test set composed of 69 fish. The model estimates the relationship between the percentage of fish that can be sexed with our model and the percentage of fish correctly sexed. For instance, to reach 1% of error in the sex determination, only 53% of the fish should be considered, whereas to reach 5% of error, 90% of the fish can be used. Compared to other available methods to sex G. aculeatus, the model is non invasive, not expensive, rapid, replicable, and can be calibrated outside of the breeding period. Copyright © 2013 Elsevier Inc. All rights reserved.

Environmental Influences on the Fish Assemblage of the Humber Estuary, U.K.

Science.gov (United States)

Marshall, S.; Elliott, M.

1998-02-01

Salinity, temperature, turbidity and dissolved oxygen were measured in conjunction with a series of fish samples taken by a 2 m beam trawl from 14 sites throughout the Humber estuary, U.K., over the period April 1992 to November 1994. Sediment type was not measured as the literature indicates that the area is homogeneous. The influences of environmental factors and the characteristics of the fish assemblage were analysed using a range of multivariate techniques, including two-way indicator species analysis, canonical correspondence analysis, principal components analysis and Spearman rank correlation. The analyses indicate that salinity is the dominant factor influencing the distribution of the species, with temperature also having a major influence. Of the species examined, whiting (Merlangius merlangus), sole (Solea solea), flounder (Pleuronectes flesus), sprat (Sprattus sprattus) and herring (Clupea harengus) showed a correlation in distribution to temperature, sole, plaice (Pleuronectes platessa), pogge (Agonus cataphractus) and stickleback (Gasterosteus aculeatus) to salinity, and whiting, flounder, pogge and stickleback to dissolved oxygen. Only cod (Gadus morhua) showed a correlation with tidal state, while whiting, pogge and stickleback were correlated to depth. Unlike in some other estuaries, turbidity did not influence the composition of the fish assemblage. Temperature and salinity fluctuations appear to influence different aspects of the community, with temperature proving to be the best predictor of total abundance, while salinity influenced the species richness and total biomass. The analyses demonstrate the most important variables with regard to environmental-biotic interactions, although they also indicate that the variables measured do not account for all of the observed variation in fish biomass and abundance.

Behavioural disturbances in a temperate fish exposed to sustained high-CO2 levels.

Directory of Open Access Journals (Sweden)

Fredrik Jutfelt

Full Text Available As atmospheric CO2 levels rise, the CO2 concentration in ocean surface waters increases through a process commonly referred to as ocean acidification. Recently, surprising behavioural modifications has been detected in the early life stages of tropical coral reef fish exposed to ocean acidification-relevant CO2 concentrations, but it has been unclear if this effect could occur in temperate waters. Here we show several severe behavioural disturbances, including effects on boldness, exploratory behaviour, lateralisation, and learning in a temperate fish, the three-spined stickleback (Gasterosteus aculeatus. The behavioural effects were consistent throughout the exposure period and increased in effect size with exposure time. We observed the effects on adult sticklebacks, a species known to be tolerant to other environmental stressors. Our findings suggest that behavioural abnormalities that stem from CO2 exposure are not restricted to sensitive tropical species or early life stages and may therefore affect fish on a global scale. The severity of disturbances and the possibility of a serious behavioural problem for fish across the globe is cause for concern.

Color signaling in conspicuous red sticklebacks: do ultraviolet signals surpass others?

Directory of Open Access Journals (Sweden)

Bakker Theo CM

2008-07-01

Full Text Available Abstract Background The use of ultraviolet (UV signals for communication tasks is widespread in vertebrates. For instance, there is a UV component to mate choice in several species. Nevertheless, it remains unclear how the signal value of the UV wave band compares to that of other regions of the animal's visible spectrum. We investigated the relative importance of UV signals compared with signals of longer wavelengths in the threespine stickleback (Gasterosteus aculeatus, a species using UV wavelengths in female and male mate choice as well as in shoaling behavior. In a choice experiment, female sticklebacks were simultaneously presented with four male visual appearances manipulated by optical filters. Each male lacked one wavelength range of the stickleback's visible spectrum corresponding to the spectral sensitivities of the four cone types. The resulting male appearances thus had no UV (UV-, no short-wave (SW-, no medium-wave (MW- or no long-wave (LW- body reflectance. Results Males without UV wavelengths and long wavelengths ("red" were least preferred. In contrast, the removal of medium and most notably short wavelengths left male attractiveness to females rather unaffected. Using color metrics, the effects of the four optical filters on stickleback perception of three male body regions were illustrated as quantal catches calculated for the four single cones. Conclusion The removal of UV light (UV- considerably reduced visual attractiveness of courting males to female three-spined sticklebacks particularly in comparison to the removal of short-wave light (SW-. We thus report first experimental evidence that the UV wave band clearly outranks at least one other part of an animal's visible spectrum (SW- in the context of communication. In addition, females were also less attracted to males presented without long wavelengths (LW- which supports the traditionally considered strong influence of the red color component on stickleback mate choice

Food intake rates of inactive fish are positively linked to boldness in three‐spined sticklebacks Gasterosteus aculeatus

Science.gov (United States)

Manica, A.; Boogert, N. J.

2016-01-01

To investigate the link between personality and maximum food intake of inactive individuals, food‐deprived three‐spined sticklebacks Gasterosteus aculeatus at rest in their home compartments were provided with ad libitum prey items. Bolder individuals ate considerably more than shyer individuals, even after accounting for body size, while sociability did not have an effect. These findings support pace‐of‐life theory predicting that life‐history strategies are linked to boldness. PMID:26940195

On the Status of Threespine Stickleback (Gasterosteus aculeatus Linnaeus 1758 in Lake Bracciano, Italy

Directory of Open Access Journals (Sweden)

Sakshi Sharda

2018-03-01

Full Text Available For many species, the Mediterranean region harbors distinct lineages that are of conservation concerns. However, many of these are threatened by habitat degradation and by the introduction of non-native species. Here, we assess the status of the native threespine stickleback (Gasterosteus aculeatus in the Lake Bracciano region in Italy, where stickleback have been historically present. During a dedicated sampling campaign in summer 2015, surveying the potential habitats that sticklebacks commonly occupy, we could not confirm the presence of this species but found introduced species to be often most abundant. Stickleback are thus likely to either have become extinct over the last decades or be on the verge to extinction in the Lake Bracciano region.

Changes in marine fish community under influence of Leningrad nuclear power plant and another human activities in the watershed of Koporskaya Bay (Gulf of Finland, Baltic Sea)

International Nuclear Information System (INIS)

Zimin, V.L.

1999-01-01

The long-time observations (1978-1997) in the Leningrad nuclear power plant cooling water-body (Koporskaya Bay) in the frame of the Regional Ecological Monitoring Program provided reliable data on the local fish community state. Regular observations allow us to trace structural changes in fish community, because they follow changes on physiological and population levels in this community. 45 species of fishes and lamprey were recorded during all investigation period. However, the species diversity is very poor. Wittaker dominance-diversity curves reflect degradation in the coastal fish community being under influence of the complex industrial and agricultural factors. The fish community is now dominated by only 2-3 species, especially threespined stickleback and ninespined stickleback; while the first species more abundant then the second one as far as ∼10 times

Temporal variation in fish mercury concentrations within lakes from the western Aleutian Archipelago, Alaska.

Directory of Open Access Journals (Sweden)

Leah A Kenney

Full Text Available We assessed temporal variation in mercury (Hg concentrations of threespine stickleback (Gasterosteus aculeatus from Agattu Island, Aleutian Archipelago, Alaska. Total Hg concentrations in whole-bodied stickleback were measured at two-week intervals from two sites in each of two lakes from June 1 to August 10, 2011 during the time period when lakes were ice-free. Across all sites and sampling events, stickleback Hg concentrations ranged from 0.37-1.07 µg/g dry weight (dw, with a mean (± SE of 0.55 ± 0.01 µg/g dw. Mean fish Hg concentrations declined by 9% during the study period, from 0.57 ± 0.01 µg/g dw in early June to 0.52 ± 0.01 µg/g dw in mid-August. Mean fish Hg concentrations were 6% higher in Loon Lake (0.56 ± 0.01 µg/g dw than in Lake 696 (0.53 ± 0.01 µg/g dw, and 4% higher in males (0.56 ± 0.01 µg/g dw than in females (0.54 ± 0.01 µg/g dw. Loon Lake was distinguished from Lake 696 by the presence of piscivorous waterbirds during the breeding season. Mercury concentrations in stickleback from Agattu Island were higher than would be expected for an area without known point sources of Hg pollution, and high enough to be of concern to the health of piscivorous wildlife.

Temporal variation in fish mercury concentrations within lakes from the western Aleutian Archipelago, Alaska

Science.gov (United States)

Kenney, Leah A.; Eagles-Smith, Collin A.; Ackerman, Joshua T.; von Hippel, Frank A.

2014-01-01

We assessed temporal variation in mercury (Hg) concentrations of threespine stickleback (Gasterosteus aculeatus) from Agattu Island, Aleutian Archipelago, Alaska. Total Hg concentrations in whole-bodied stickleback were measured at two-week intervals from two sites in each of two lakes from June 1 to August 10, 2011 during the time period when lakes were ice-free. Across all sites and sampling events, stickleback Hg concentrations ranged from 0.37–1.07 µg/g dry weight (dw), with a mean (± SE) of 0.55±0.01 µg/g dw. Mean fish Hg concentrations declined by 9% during the study period, from 0.57±0.01 µg/g dw in early June to 0.52±0.01 µg/g dw in mid-August. Mean fish Hg concentrations were 6% higher in Loon Lake (0.56±0.01 µg/g dw) than in Lake 696 (0.53±0.01 µg/g dw), and 4% higher in males (0.56±0.01 µg/g dw) than in females (0.54±0.01 µg/g dw). Loon Lake was distinguished from Lake 696 by the presence of piscivorous waterbirds during the breeding season. Mercury concentrations in stickleback from Agattu Island were higher than would be expected for an area without known point sources of Hg pollution, and high enough to be of concern to the health of piscivorous wildlife.

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

Science.gov (United States)

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

2012-11-01

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

Rapid analysis of diclofenac and some of its transformation products in the three-spined stickleback, Gasterosteus aculeatus, by liquid chromatography-tandem mass spectrometry.

Science.gov (United States)

Daniele, Gaëlle; Fieu, Maëva; Joachim, Sandrine; Bado-Nilles, Anne; Baudoin, Patrick; Turies, Cyril; Porcher, Jean-Marc; Andres, Sandrine; Vulliet, Emmanuelle

2016-06-01

Pharmaceuticals are emerging organic contaminants ubiquitously present in the environment due to incessant input into the aquatic compartment mainly resulting from incomplete removal in wastewater treatment plants. One of the major preoccupations concerning pharmaceuticals released into surface waters is their potential for bioaccumulation in biota, possibly leading to deleterious effects on ecosystems especially as they could affect a broad variety of organisms living in or depending on the aquatic environment. Thus, the development of accurate and sensitive methods is necessary to detect these compounds in aquatic ecosystems. Considering this need, this study deals with the analytical development of a methodology to quantify traces of diclofenac together with some of its biotic and abiotic transformation products in whole-body tissue of three-spined stickleback. A simple and reliable extraction method based on a modified QuEChERS extraction is implemented on 200 mg of fish. The detection and quantification of the ten target compounds are performed using liquid chromatography-tandem mass spectrometry. The whole process was successfully validated regarding linearity, recovery, repeatability, and reproducibility. The method limits of detection and quantification do not exceed 1 ng/g. To reproduce environmental conditions, we measured the concentration of DCF and its transformation products in three-spined sticklebacks after a 6-month exposure in mesocosms at several levels of DCF ranging from 0.05 to 4.1 μg/L. The phase I metabolite 4'-hydroxydiclofenac was detected in fish samples exposed at the highest DCF concentration. Graphical abstract Analysis of diclofenac and some of its transformation products in the three-spined stickleback, Gasterosteus aculeatus, by QuEChERS extraction followed by LC-MS/MS.

Hormonal changes over the spawning cycle in the female three-spined stickleback, Gasterosteus aculeatus.

Science.gov (United States)

Roufidou, Chrysoula; Schmitz, Monika; Mayer, Ian; Sebire, Marion; Katsiadaki, Ioanna; Shao, Yi Ta; Borg, Bertil

2018-02-01

Female three-spined sticklebacks are batch spawners laying eggs in a nest built by the male. We sampled female sticklebacks at different time points, when they were ready to spawn and 6, 24, 48 and 72h post-spawning (hps) with a male. Following spawning, almost all females (15 out of 19) had ovulated eggs again at Day 3 post-spawning (72hps). At sampling, plasma, brain and pituitaries were collected, and the ovary and liver were weighed. Testosterone (T) and estradiol (E2) were measured by radioimmunoassay. Moreover, the mRNA levels of follicle-stimulating hormone (fsh-β) and luteinizing hormone (lh-β) in the pituitary, and of the gonadotropin-releasing hormones (GnRHs: gnrh2, gnrh3) and kisspeptin (kiss2) and its G protein-coupled receptor (gpr54) in the brain were measured by real-time qPCR. Ovarian weights peaked in "ready to spawn" females, dropped after spawning, before again progressively increasing from 6 to 72hps. Plasma T levels showed peaks at 24 and 48hps and decreased at 72hps, while E2 levels increased already at 6hps and remained at high levels up to 48hps. There was a strong positive correlation between T and E2 levels over the spawning cycle. Pituitary lh-β mRNA levels showed a peak at 48hps, while fsh-β did not change. The neuropeptides and gpr54 did not show any changes. The changes in T and E2 over the stickleback spawning cycle were largely consistent with those found in other multiple-spawning fishes whereas the marked correlation between T and E2 does not support T having other major roles over the cycle than being a precursor for E2. Crown Copyright © 2017. Published by Elsevier Inc. All rights reserved.

Geographical variation in colour of female threespine stickleback (Gasterosteus aculeatus).

Science.gov (United States)

French, Connor M; Ingram, Travis; Bolnick, Daniel I

2018-01-01

The ecological multifunctionality of colour often results in multiple selective pressures operating on a single trait. Most research on colour evolution focuses on males because they are the most conspicuous sex in most species. This bias can limit inferences about the ecological drivers of colour evolution. For example, little is known about population divergence in colour of female threespine stickleback ( Gasterosteus aculeatus ), which is among the most intensively-studied model vertebrates in evolution, ecology, and behaviour. In contrast, the evolution and ecology of colour in male stickleback has received considerable attention. One aspect of female colouration that is lacking previous research is non-ornamental body colour. Non-ornamental colour can play defensive and social roles, and indicate other aspects of female stickleback ecology. To remedy this knowledge gap, we measured the colour and brightness of one dorsal and one ventral lateral area on female stickleback from nine lake populations on Vancouver Island. We found that lake populations varied in overall colour brightness and dorso-ventral contrast. In addition, we found that female brightness increased with lake size, indicating potential ecological drivers of these colour differences. Our results demonstrate that there is substantial scope for future research on female colour diversification, which has been overlooked because past researchers focused on dramatic male nuptial colours.

Characterization of a genotoxicity biomarker in three-spined stickleback (Gasterosteus aculeatus L.): Biotic variability and integration in a battery of biomarkers for environmental monitoring.

Science.gov (United States)

Santos, Raphael; Joyeux, Aude; Palluel, Olivier; Palos-Ladeiro, Mélissa; Besnard, Aurélien; Blanchard, Christophe; Porcher, Jean Marc; Bony, Sylvie; Devaux, Alain; Sanchez, Wilfried

2016-04-01

As a large array of hazardous substances exhibiting genotoxicity are discharged into surface water, this work aimed at assessing the relevance of adding a genotoxicity biomarker in a battery of biomarkers recently developed in the model fish three-spined stickleback (Gasterosteus aculeatus). First the confounding influence of gender, body length, and season (used as a proxy of age and of the fish reproductive status, respectively) on the level of primary DNA damage in erythrocytes was investigated in wild sticklebacks. Then, the genotoxity biomarker was included in a large battery of biomarkers assessing xenobiotic biotransformation, oxidative stress and neurotoxicity, and implemented in five sites. Gender, age and reproductive status did not influence DNA damage level in fish from the reference site. A significant relationship between the level of primary DNA damage and fish length (as a proxy of age also correlated to the season) was highlighted in the contaminated site. Among all biomarkers investigated in the field, the level of DNA damage was one of the four most discriminating biomarkers with EROD, catalase activity and the level of lipid peroxidation representing together 75.40% of the discriminating power in sampled fish. The level of DNA damage was correlated to the EROD activity and to the level of peroxidation, which mainly discriminated fish from sites under urban pressure. Finally, Integrated Biomarker Response indexes (IBRv2), which were calculated with the whole biomarker response dataset exhibited higher values in the Reveillon (9.62), the Scarpe and Rhonelle contaminated sites (5.11 and 4.90) compared with the two reference sites (2.38 and 2.55). The present work highlights that integration of a genotoxicity biomarker in a multiparametric approach is relevant to assess ecotoxicological risk in freshwater aquatic organisms. © 2014 Wiley Periodicals, Inc.

Maternal experience with predation risk influences genome-wide embryonic gene expression in threespined sticklebacks (Gasterosteus aculeatus).

Science.gov (United States)

Mommer, Brett C; Bell, Alison M

2014-01-01

There is growing evidence for nongenetic effects of maternal experience on offspring. For example, previous studies have shown that female threespined stickleback fish (Gasterosteus aculeatus) exposed to predation risk produce offspring with altered behavior, metabolism and stress physiology. Here, we investigate the effect of maternal exposure to predation risk on the embryonic transcriptome in sticklebacks. Using RNA-sequencing we compared genome-wide transcription in three day post-fertilization embryos of predator-exposed and control mothers. There were hundreds of differentially expressed transcripts between embryos of predator-exposed mothers and embryos of control mothers including several non-coding RNAs. Gene Ontology analysis revealed biological pathways involved in metabolism, epigenetic inheritance, and neural proliferation and differentiation that differed between treatments. Interestingly, predation risk is associated with an accelerated life history in many vertebrates, and several of the genes and biological pathways that were identified in this study suggest that maternal exposure to predation risk accelerates the timing of embryonic development. Consistent with this hypothesis, embryos of predator-exposed mothers were larger than embryos of control mothers. These findings point to some of the molecular mechanisms that might underlie maternal effects.

Maternal experience with predation risk influences genome-wide embryonic gene expression in threespined sticklebacks (Gasterosteus aculeatus.

Directory of Open Access Journals (Sweden)

Brett C Mommer

Full Text Available There is growing evidence for nongenetic effects of maternal experience on offspring. For example, previous studies have shown that female threespined stickleback fish (Gasterosteus aculeatus exposed to predation risk produce offspring with altered behavior, metabolism and stress physiology. Here, we investigate the effect of maternal exposure to predation risk on the embryonic transcriptome in sticklebacks. Using RNA-sequencing we compared genome-wide transcription in three day post-fertilization embryos of predator-exposed and control mothers. There were hundreds of differentially expressed transcripts between embryos of predator-exposed mothers and embryos of control mothers including several non-coding RNAs. Gene Ontology analysis revealed biological pathways involved in metabolism, epigenetic inheritance, and neural proliferation and differentiation that differed between treatments. Interestingly, predation risk is associated with an accelerated life history in many vertebrates, and several of the genes and biological pathways that were identified in this study suggest that maternal exposure to predation risk accelerates the timing of embryonic development. Consistent with this hypothesis, embryos of predator-exposed mothers were larger than embryos of control mothers. These findings point to some of the molecular mechanisms that might underlie maternal effects.

In vitro effects of prostaglandin E2 on leucocytes from sticklebacks (Gasterosteus aculeatus) infected and not infected with the cestode Schistocephalus solidus.

Science.gov (United States)

Kutyrev, Ivan A; Franke, Frederik; Büscher, Janine; Kurtz, Joachim; Scharsack, Jörn P

2014-12-01

Many helminth parasites have evolved strategies to evade the immune response of their hosts, which includes immunomodulation. Prostaglandin E2 (PGE2) is one of the best-described immunomodulators in mammalian helminth parasite infections. We hypothesized that also in teleost fish anti-helminthic immune responses are regulated via PGE2. We used a model system consisting of the tapeworm Schistocephalus solidus and its host, the three-spined stickleback (Gasterosteus aculeatus), to investigate in vitro effects of PGE2 on head kidney leucocytes (HKL) derived from sticklebacks that were experimentally infected with S. solidus. PGE2 was tested alone or in combination with either S. solidus antigens or bacterial lipopolysaccharides (LPS). After in vitro culture, cell viability and changes in leucocyte subpopulations (granulocytes to lymphocytes ratios) were monitored by flow cytometry and HKL were tested for their capacity to produce reactive oxygen species (ROS) with a chemiluminescence assay. In short term (2 h) HKL cultures PGE2 did not change the total numbers of live HKL, but the production of ROS decreased significantly with high (0.1 μmol L(-1)) PGE2 concentrations. In long-term (96 h) cultures high PGE2 concentrations induced a sharp decrease of leucocytes viability, while low (0.1 pmol L(-1)) and intermediate (0.1 nmol L(-1)) concentrations of PGE2 caused elevated leucocyte viability compared to controls. This coincided with reduced ROS production in cultures with high PGE2 and elevated ROS production in cultures with low PGE2. Granulocyte to lymphocyte ratios increased with high PGE2 concentrations alone and in combination with S. solidus antigens and LPS, most prominently with HKL from S. solidus infected sticklebacks. The present study supports the hypothesis that PGE2 might be an immunomodulator in tapeworm-fish parasite-host interactions. Copyright © 2014 Elsevier Ltd. All rights reserved.

Androgen receptor-beta mRNA levels in different tissues in breeding and post-breeding male and female sticklebacks, Gasterosteus aculeatus

Directory of Open Access Journals (Sweden)

Hoffmann Erik

2012-03-01

Full Text Available Abstract Background Androgens induce male characters by activating androgen receptors (AR. Previous quantitative studies on AR in fishes have been limited to few tissues and/or a single season/reproductive state. The aim of this investigation was to study the possible role of AR-beta expression levels in the control of male traits in the three-spined stickleback. To that end, AR-beta expression levels in major tissues in breeding and post-breeding male and female sticklebacks were examined. Methods AR-beta mRNA levels were quantified in ten tissues; eye, liver, axial muscle, heart, brain, intestine, ovary, testis, kidney and pectoral muscle in six breeding and post-breeding males and females using reverse transcription quantitative PCR. Results Breeding in contrast to post-breeding males built nests and showed secondary sexual characters (e.g. kidney hypertrophy and elevated androgen levels. Post-breeding females had lower ovarian weights and testosterone levels than breeding females. AR-beta was expressed in all studied tissues in both sexes and reproductive states with the highest expression in the gonads and in the kidneys. The kidney is an androgen target organ in sticklebacks, from which breeding males produce the protein spiggin, which is used in nest-building. There was also high AR-beta expression in the intestine, an organ that appears to take over hyperosmo-regulation in fresh water when the kidney hypertrophies in mature males and largely loses this function. The only tissue that showed effects of sex or reproductive state on AR-beta mRNA levels was the kidneys, where post-breeding males displayed higher AR-beta mRNA levels than breeding males. Conclusion The results indicate that changes in AR-beta mRNA levels play no or little role in changes in androgen dependent traits in the male stickleback.

Genome-Wide DNA Methylation Profiling Reveals Epigenetic Adaptation of Stickleback to Marine and Freshwater Conditions.

Science.gov (United States)

Artemov, Artem V; Mugue, Nikolai S; Rastorguev, Sergey M; Zhenilo, Svetlana; Mazur, Alexander M; Tsygankova, Svetlana V; Boulygina, Eugenia S; Kaplun, Daria; Nedoluzhko, Artem V; Medvedeva, Yulia A; Prokhortchouk, Egor B

2017-09-01

The three-spined stickleback (Gasterosteus aculeatus) represents a convenient model to study microevolution-adaptation to a freshwater environment. Although genetic adaptations to freshwater environments are well-studied, epigenetic adaptations have attracted little attention. In this work, we investigated the role of DNA methylation in the adaptation of the marine stickleback population to freshwater conditions. DNA methylation profiling was performed in marine and freshwater populations of sticklebacks, as well as in marine sticklebacks placed into a freshwater environment and freshwater sticklebacks placed into seawater. We showed that the DNA methylation profile after placing a marine stickleback into fresh water partially converged to that of a freshwater stickleback. For six genes including ATP4A ion pump and NELL1, believed to be involved in skeletal ossification, we demonstrated similar changes in DNA methylation in both evolutionary and short-term adaptation. This suggested that an immediate epigenetic response to freshwater conditions can be maintained in freshwater population. Interestingly, we observed enhanced epigenetic plasticity in freshwater sticklebacks that may serve as a compensatory regulatory mechanism for the lack of genetic variation in the freshwater population. For the first time, we demonstrated that genes encoding ion channels KCND3, CACNA1FB, and ATP4A were differentially methylated between the marine and the freshwater populations. Other genes encoding ion channels were previously reported to be under selection in freshwater populations. Nevertheless, the genes that harbor genetic and epigenetic changes were not the same, suggesting that epigenetic adaptation is a complementary mechanism to selection of genetic variants favorable for freshwater environment. © The Author 2017. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Application of Passive Sampling to Characterise the Fish Exometabolome

Directory of Open Access Journals (Sweden)

Mark R. Viant

2017-02-01

Full Text Available The endogenous metabolites excreted by organisms into their surrounding environment, termed the exometabolome, are important for many processes including chemical communication. In fish biology, such metabolites are also known to be informative markers of physiological status. While metabolomics is increasingly used to investigate the endogenous biochemistry of organisms, no non-targeted studies of the metabolic complexity of fish exometabolomes have been reported to date. In environmental chemistry, Chemcatcher® (Portsmouth, UK passive samplers have been developed to sample for micro-pollutants in water. Given the importance of the fish exometabolome, we sought to evaluate the capability of Chemcatcher® samplers to capture a broad spectrum of endogenous metabolites excreted by fish and to measure these using non-targeted direct infusion mass spectrometry metabolomics. The capabilities of C18 and styrene divinylbenzene reversed-phase sulfonated (SDB-RPS Empore™ disks for capturing non-polar and polar metabolites, respectively, were compared. Furthermore, we investigated real, complex metabolite mixtures excreted from two model fish species, rainbow trout (Oncorhynchus mykiss and three-spined stickleback (Gasterosteus aculeatus. In total, 344 biological samples and 28 QC samples were analysed, revealing 646 and 215 m/z peaks from trout and stickleback, respectively. The measured exometabolomes were principally affected by the type of Empore™ (Hemel Hempstead, UK disk and also by the sampling time. Many peaks were putatively annotated, including several bile acids (e.g., chenodeoxycholate, taurocholate, glycocholate, glycolithocholate, glycochenodeoxycholate, glycodeoxycholate. Collectively these observations show the ability of Chemcatcher® passive samplers to capture endogenous metabolites excreted from fish.

Geographical variation in colour of female threespine stickleback (Gasterosteus aculeatus

Directory of Open Access Journals (Sweden)

Connor M. French

2018-05-01

Full Text Available The ecological multifunctionality of colour often results in multiple selective pressures operating on a single trait. Most research on colour evolution focuses on males because they are the most conspicuous sex in most species. This bias can limit inferences about the ecological drivers of colour evolution. For example, little is known about population divergence in colour of female threespine stickleback (Gasterosteus aculeatus, which is among the most intensively-studied model vertebrates in evolution, ecology, and behaviour. In contrast, the evolution and ecology of colour in male stickleback has received considerable attention. One aspect of female colouration that is lacking previous research is non-ornamental body colour. Non-ornamental colour can play defensive and social roles, and indicate other aspects of female stickleback ecology. To remedy this knowledge gap, we measured the colour and brightness of one dorsal and one ventral lateral area on female stickleback from nine lake populations on Vancouver Island. We found that lake populations varied in overall colour brightness and dorso-ventral contrast. In addition, we found that female brightness increased with lake size, indicating potential ecological drivers of these colour differences. Our results demonstrate that there is substantial scope for future research on female colour diversification, which has been overlooked because past researchers focused on dramatic male nuptial colours.

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

Science.gov (United States)

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

2009-01-01

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

Attractive males have faster sperm in three-spined sticklebacks Gasterosteus aculeatus

Directory of Open Access Journals (Sweden)

Marion MEHLIS, Lukas K. HILKE, Theo C. M. BAKKER

2013-12-01

Full Text Available Recent studies have revealed that sexually selected traits may signal sperm quality and hence male fertilisation ability. There is also evidence that the expression of male sexual ornamentation and associated sperm characteristics depend on an individual’s ability to cope with oxidative stress. Carotenoids are known for their antioxidant properties and carotenoid-based ornaments might represent honest signals as these pigments can be traded off between the investment in sexual ornamentation, sperm function as well as immune response. In this study, we examined the relationship between sexual ornamentation (breeding coloration and sperm characteristics (e.g., velocity and morphology in the three-spined stickleback Gasterosteus aculeatus, an externally fertilising fish species, in which sperm competition commonly occurs. During the breeding season males are sperm limited and develop a conspicuous carotenoid-based coloration, which is under strong pre-copulatory sexual selection due to female mate choice and male-male competition. The results of the present study show that the expression of stickleback male breeding coloration is significantly positively associated with the linearity of sperm movement, whereas sperm morphology (head length to tail length ratio is significantly negatively related to the trajectory of sperm movement. Moreover, there is some support for the phenotype-linked fertility hypothesis as the intensity of male red breeding coloration is significantly positively correlated with sperm velocity, which is supposed to be an important determinant of fertilisation success in external fertilisers, indicating the honesty of the sexually selected nuptial red coloration [Current Zoology 59 (6: 761-768, 2013].

Oxygen consumption by sticklebacks (Gasterosteus aculeatus L. ) exposed to zinc

Energy Technology Data Exchange (ETDEWEB)

Brafield, A.E.; Matthiessen, P.

1976-10-01

The rate of oxygen consumption by sticklebacks has been studied by long-term continuous-flow respirometry. Exposure to 1 ppM zinc in calcium-free water causes wide variations in individual responses, but oxygen uptake tends to rise and then become extremely erratic, before declining as death approaches. Behavioural abnormalities such as increased ventilation rate, loss of balance, and long periods of inactivity alternating with spasmodic swimming also occur. Exposure to 6.5 ppM zinc in high-calcium water generally causes a rise in oxygen consumption, followed by fluctuations in the rate of uptake, but no behavioural abnormalities occur and deaths are rare even after exposure for 400 h. If restored to zinc-free water after 40 h exposure to zinc, recovery is generally complete, although fluctuating rates of oxygen uptake persist. These results are discussed in relation to previous work on the effects of heavy metals on fish respiration.

Uptake and loss of dissolved zinc by the stickleback gasterosteus Aculeatus l. [Zinc 65

Energy Technology Data Exchange (ETDEWEB)

Matthiessen, P.; Brafield, A.E.

1977-01-01

Uptake and loss by sticklebacks of both stable zinc and /sup 65/Zn in hard and soft water were studied for periods up to 400 h. In calcium-free water, the zinc uptake curve is approximately asymptotic over a period of 24 h, while in hard water internal Zn levels dropped at 24 h. Over 5 h, fish in hard tapwater absorb about 3 to 5 times more Zn than those in calcium-free water. There is positive linear correlation between log Zn uptake and log wet weight of fish. Whole-body concentration factors (c.f.) at 16 h reach a maximum of 12.2 (mean = 2.9), highest concentrations of Zn being found in the gills (mean c.f. = 5.1), and lowest concentrations in the gonads (mean c.f. = 0.8). Over longer periods (400 h), internal stable zinc levels of fish exposed to 1 and 4 ppM Zn/sup +2/ remain little higher than controls (max. 28%) /sup 65/Zn efflux in zinc-free water falls to zero after 5 h, more zinc (78%) being lost after uptake in tapwater than in calcium-free water (56%).

Ongoing niche differentiation under high gene flow in a polymorphic brackish water threespine stickleback (Gasterosteus aculeatus) population.

Science.gov (United States)

Østbye, Kjartan; Taugbøl, Annette; Ravinet, Mark; Harrod, Chris; Pettersen, Ruben Alexander; Bernatchez, Louis; Vøllestad, Leif Asbjørn

2018-02-05

Marine threespine sticklebacks colonized and adapted to brackish and freshwater environments since the last Pleistocene glacial. Throughout the Holarctic, three lateral plate morphs are observed; the low, partial and completely plated morph. We test if the three plate morphs in the brackish water Lake Engervann, Norway, differ in body size, trophic morphology (gill raker number and length), niche (stable isotopes; δ 15 N, δ 13 C, and parasites (Theristina gasterostei, Trematoda spp.)), genetic structure (microsatellites) and the lateral-plate encoding Stn382 (Ectodysplasin) gene. We examine differences temporally (autumn 2006/spring 2007) and spatially (upper/lower sections of the lake - reflecting low versus high salinity). All morphs belonged to one gene pool. The complete morph was larger than the low plated, with the partial morph intermediate. The number of lateral plates ranged 8-71, with means of 64.2 for complete, 40.3 for partial, and 14.9 for low plated morph. Stickleback δ 15 N was higher in the lower lake section, while δ 13 C was higher in the upper section. Stickleback isotopic values were greater in autumn. The low plated morph had larger variances in δ 15 N and δ 13 C than the other morphs. Sticklebacks in the upper section had more T. gasterostei than in the lower section which had more Trematoda spp. Sticklebacks had less T. gasterostei, but more Trematoda spp. in autumn than spring. Sticklebacks with few and short rakers had more T. gasterostei, while sticklebacks with longer rakers had more Trematoda. spp. Stickleback with higher δ 15 N values had more T. gasterostei, while sticklebacks with higher δ 15 N and δ 13 C values had more Trematoda spp. The low plated morph had fewer Trematoda spp. than other morphs. Trait-ecology associations may imply that the three lateral plate morphs in the brackish water lagoon of Lake Engervann are experiencing ongoing divergent selection for niche and migratory life history strategies under high gene

Metabolic depression and the evolution of hypoxia tolerance in threespine stickleback, Gasterosteus aculeatus.

Science.gov (United States)

Regan, Matthew D; Gill, Ivan S; Richards, Jeffrey G

2017-11-01

Anthropogenic increases in global temperature and agricultural runoff are increasing the prevalence of aquatic hypoxia throughout the world. We investigated the potential for a relatively rapid evolution of hypoxia tolerance using two isolated (for less than 11 000 years) populations of threespine stickleback: one from a lake that experiences long-term hypoxia (Alta Lake, British Columbia) and one from a lake that does not (Trout Lake, British Columbia). Loss-of-equilibrium (LOE) experiments revealed that the Alta Lake stickleback were significantly more tolerant of hypoxia than the Trout Lake stickleback, and calorimetry experiments revealed that the enhanced tolerance of Alta Lake stickleback may be associated with their ability to depress metabolic rate (as indicated by metabolic heat production) by 33% in hypoxia. The two populations showed little variation in their capacities for O 2 extraction and anaerobic metabolism. These results reveal that intraspecific variation in hypoxia tolerance can develop over relatively short geological timescales, as can metabolic rate depression, a complex biochemical response that may be favoured in long-term hypoxic environments. © 2017 The Author(s).

Evolution of multiple phosphodiesterase isoforms in stickleback involved in cAMP signal transduction pathway.

Science.gov (United States)

Sato, Yukuto; Hashiguchi, Yasuyuki; Nishida, Mutsumi

2009-02-20

Duplicate genes are considered to have evolved through the partitioning of ancestral functions among duplicates (subfunctionalization) and/or the acquisition of novel functions from a beneficial mutation (neofunctionalization). Additionally, an increase in gene dosage resulting from duplication may also confer an advantageous effect, as has been suggested for histone, tRNA, and rRNA genes. Currently, there is little understanding of the effect of increased gene dosage on subcellular networks like signal transduction pathways. Addressing this issue may provide further insights into the evolution by gene duplication. We analyzed the evolution of multiple stickleback phosphodiesterase (PDE, EC: 3.1.4.17) 1C genes involved in the cyclic nucleotide signaling pathway. Stickleback has 8-9 copies of this gene, whereas only one or two loci exist in other model vertebrates. Our phylogenetic and synteny analyses suggested that the multiple PDE1C genes in stickleback were generated by repeated duplications of >100-kbp chromosome segments. Sequence evolution analysis did not provide strong evidence for neofunctionalization in the coding sequences of stickleback PDE1C isoforms. On the other hand, gene expression analysis suggested that the derived isoforms acquired expression in new organs, implying their neofunctionalization in terms of expression patterns. In addition, at least seven isoforms of the stickleback PDE1C were co-expressed with olfactory-type G-proteins in the nose, suggesting that PDE1C dosage is increased in the stickleback olfactory transduction (OT) pathway. In silico simulations of OT implied that the increased PDE1C dosage extends the longevity of the depolarization signals of the olfactory receptor neuron. The predicted effect of the increase in PDE1C products on the OT pathway may play an important role in stickleback behavior and ecology. However, this possibility should be empirically examined. Our analyses imply that an increase in gene product sometimes

Evolution of multiple phosphodiesterase isoforms in stickleback involved in cAMP signal transduction pathway

Directory of Open Access Journals (Sweden)

Nishida Mutsumi

2009-02-01

Full Text Available Abstract Background Duplicate genes are considered to have evolved through the partitioning of ancestral functions among duplicates (subfunctionalization and/or the acquisition of novel functions from a beneficial mutation (neofunctionalization. Additionally, an increase in gene dosage resulting from duplication may also confer an advantageous effect, as has been suggested for histone, tRNA, and rRNA genes. Currently, there is little understanding of the effect of increased gene dosage on subcellular networks like signal transduction pathways. Addressing this issue may provide further insights into the evolution by gene duplication. Results We analyzed the evolution of multiple stickleback phosphodiesterase (PDE, EC: 3.1.4.17 1C genes involved in the cyclic nucleotide signaling pathway. Stickleback has 8–9 copies of this gene, whereas only one or two loci exist in other model vertebrates. Our phylogenetic and synteny analyses suggested that the multiple PDE1C genes in stickleback were generated by repeated duplications of >100-kbp chromosome segments. Sequence evolution analysis did not provide strong evidence for neofunctionalization in the coding sequences of stickleback PDE1C isoforms. On the other hand, gene expression analysis suggested that the derived isoforms acquired expression in new organs, implying their neofunctionalization in terms of expression patterns. In addition, at least seven isoforms of the stickleback PDE1C were co-expressed with olfactory-type G-proteins in the nose, suggesting that PDE1C dosage is increased in the stickleback olfactory transduction (OT pathway. In silico simulations of OT implied that the increased PDE1C dosage extends the longevity of the depolarization signals of the olfactory receptor neuron. Conclusion The predicted effect of the increase in PDE1C products on the OT pathway may play an important role in stickleback behavior and ecology. However, this possibility should be empirically examined. Our

Variation in fish community structure, richness and diversity of 56 Danish lakes with contrasting depth and trophic state: Does the method matter?

DEFF Research Database (Denmark)

Menezes, Rosemberg

2011-01-01

The understanding of the variables that determine the structure and composition of fish communities is crucial for developing fish monitoring programs for lakes. Although electrofishing has long been recognized as an efficient method for quantitative investigations of fish populations, it has typ...... are not well caught in the gill nets such as eel, common carp (Carassius carassius) and stickleback (Gasterosteus aculeatus)....

RSCA genotyping of MHC for high-throughput evolutionary studies in the model organism three-spined stickleback Gasterosteus aculeatus

Science.gov (United States)

Lenz, Tobias L; Eizaguirre, Christophe; Becker, Sven; Reusch, Thorsten BH

2009-01-01

Background In all jawed vertebrates, highly polymorphic genes of the major histocompatibility complex (MHC) encode antigen presenting molecules that play a key role in the adaptive immune response. Their polymorphism is composed of multiple copies of recently duplicated genes, each possessing many alleles within populations, as well as high nucleotide divergence between alleles of the same species. Experimental evidence is accumulating that MHC polymorphism is a result of balancing selection by parasites and pathogens. In order to describe MHC diversity and analyse the underlying mechanisms that maintain it, a reliable genotyping technique is required that is suitable for such highly variable genes. Results We present a genotyping protocol that uses Reference Strand-mediated Conformation Analysis (RSCA), optimised for recently duplicated MHC class IIB genes that are typical for many fish and bird species, including the three-spined stickleback, Gasterosteus aculeatus. In addition we use a comprehensive plasmid library of MHC class IIB alleles to determine the nucleotide sequence of alleles represented by RSCA allele peaks. Verification of the RSCA typing by cloning and sequencing demonstrates high congruency between both methods and provides new insight into the polymorphism of classical stickleback MHC genes. Analysis of the plasmid library additionally reveals the high resolution and reproducibility of the RSCA technique. Conclusion This new RSCA genotyping protocol offers a fast, but sensitive and reliable way to determine the MHC allele repertoire of three-spined sticklebacks. It therefore provides a valuable tool to employ this highly polymorphic and adaptive marker in future high-throughput studies of host-parasite co-evolution and ecological speciation in this emerging model organism. PMID:19291291

RSCA genotyping of MHC for high-throughput evolutionary studies in the model organism three-spined stickleback Gasterosteus aculeatus

Directory of Open Access Journals (Sweden)

Becker Sven

2009-03-01

Full Text Available Abstract Background In all jawed vertebrates, highly polymorphic genes of the major histocompatibility complex (MHC encode antigen presenting molecules that play a key role in the adaptive immune response. Their polymorphism is composed of multiple copies of recently duplicated genes, each possessing many alleles within populations, as well as high nucleotide divergence between alleles of the same species. Experimental evidence is accumulating that MHC polymorphism is a result of balancing selection by parasites and pathogens. In order to describe MHC diversity and analyse the underlying mechanisms that maintain it, a reliable genotyping technique is required that is suitable for such highly variable genes. Results We present a genotyping protocol that uses Reference Strand-mediated Conformation Analysis (RSCA, optimised for recently duplicated MHC class IIB genes that are typical for many fish and bird species, including the three-spined stickleback, Gasterosteus aculeatus. In addition we use a comprehensive plasmid library of MHC class IIB alleles to determine the nucleotide sequence of alleles represented by RSCA allele peaks. Verification of the RSCA typing by cloning and sequencing demonstrates high congruency between both methods and provides new insight into the polymorphism of classical stickleback MHC genes. Analysis of the plasmid library additionally reveals the high resolution and reproducibility of the RSCA technique. Conclusion This new RSCA genotyping protocol offers a fast, but sensitive and reliable way to determine the MHC allele repertoire of three-spined sticklebacks. It therefore provides a valuable tool to employ this highly polymorphic and adaptive marker in future high-throughput studies of host-parasite co-evolution and ecological speciation in this emerging model organism.

Region-wide and ecotype-specific differences in demographic histories of threespine stickleback populations, estimated from whole genome sequences.

Science.gov (United States)

Liu, Shenglin; Hansen, Michael M; Jacobsen, Magnus W

2016-10-01

We analysed 81 whole genome sequences of threespine sticklebacks from Pacific North America, Greenland and Northern Europe, representing 16 populations. Principal component analysis of nuclear SNPs grouped populations according to geographical location, with Pacific populations being more divergent from each other relative to European and Greenlandic populations. Analysis of mitogenome sequences showed Northern European populations to represent a single phylogeographical lineage, whereas Greenlandic and particularly Pacific populations showed admixture between lineages. We estimated demographic history using a genomewide coalescence with recombination approach. The Pacific populations showed gradual population expansion starting >100 Kya, possibly reflecting persistence in cryptic refuges near the present distributional range, although we do not rule out possible influence of ancient admixture. Sharp population declines ca. 14-15 Kya were suggested to reflect founding of freshwater populations by marine ancestors. In Greenland and Northern Europe, demographic expansion started ca. 20-25 Kya coinciding with the end of the Last Glacial Maximum. In both regions, marine and freshwater populations started to show different demographic trajectories ca. 8-9 Kya, suggesting that this was the time of recolonization. In Northern Europe, this estimate was surprisingly late, but found support in subfossil evidence for presence of several freshwater fish species but not sticklebacks 12 Kya. The results demonstrate distinctly different demographic histories across geographical regions with potential consequences for adaptive processes. They also provide empirical support for previous assumptions about freshwater populations being founded independently from large, coherent marine populations, a key element in the Transporter Hypothesis invoked to explain the widespread occurrence of parallel evolution across freshwater stickleback populations. © 2016 John Wiley & Sons Ltd.

Population genomics of parallel adaptation in threespine stickleback using sequenced RAD tags.

Directory of Open Access Journals (Sweden)

Paul A Hohenlohe

2010-02-01

Full Text Available Next-generation sequencing technology provides novel opportunities for gathering genome-scale sequence data in natural populations, laying the empirical foundation for the evolving field of population genomics. Here we conducted a genome scan of nucleotide diversity and differentiation in natural populations of threespine stickleback (Gasterosteus aculeatus. We used Illumina-sequenced RAD tags to identify and type over 45,000 single nucleotide polymorphisms (SNPs in each of 100 individuals from two oceanic and three freshwater populations. Overall estimates of genetic diversity and differentiation among populations confirm the biogeographic hypothesis that large panmictic oceanic populations have repeatedly given rise to phenotypically divergent freshwater populations. Genomic regions exhibiting signatures of both balancing and divergent selection were remarkably consistent across multiple, independently derived populations, indicating that replicate parallel phenotypic evolution in stickleback may be occurring through extensive, parallel genetic evolution at a genome-wide scale. Some of these genomic regions co-localize with previously identified QTL for stickleback phenotypic variation identified using laboratory mapping crosses. In addition, we have identified several novel regions showing parallel differentiation across independent populations. Annotation of these regions revealed numerous genes that are candidates for stickleback phenotypic evolution and will form the basis of future genetic analyses in this and other organisms. This study represents the first high-density SNP-based genome scan of genetic diversity and differentiation for populations of threespine stickleback in the wild. These data illustrate the complementary nature of laboratory crosses and population genomic scans by confirming the adaptive significance of previously identified genomic regions, elucidating the particular evolutionary and demographic history of such

Population bottlenecks, genetic diversity and breeding ability of the three-spined stickleback (Gasterosteus aculeatus) from three polluted English Rivers.

Science.gov (United States)

Santos, Eduarda M; Hamilton, Patrick B; Coe, Tobias S; Ball, Jonathan S; Cook, Alastair C; Katsiadaki, Ioanna; Tyler, Charles R

2013-10-15

Pollution is a significant environmental pressure on fish populations in both freshwater and marine environments. Populations subjected to chronic exposure to pollutants can experience impacts ranging from altered reproductive capacity to changes in population genetic structure. Few studies, however, have examined the reproductive vigor of individuals within populations inhabiting environments characterized by chronic pollution. In this study we undertook an analysis of populations of three-spined sticklebacks (Gasterosteus aculeatus) from polluted sites, to determine levels of genetic diversity, assess for evidence of historic population genetic bottlenecks and determine the reproductive competitiveness of males from these locations. The sites chosen included locations in the River Aire, the River Tees and the River Birket, English rivers that have been impacted by pollution from industrial and/or domestic effluents for over 100 years. Male reproductive competitiveness was determined via competitive breeding experiments with males and females derived from a clean water site, employing DNA microsatellites to determine parentage outcome. Populations of stickleback collected from the three historically polluted sites showed evidence of recent population bottlenecks, although only the River Aire population showed low genetic diversity. In contrast, fish collected from two relatively unpolluted sites within the River Gowy and Houghton Springs showed weak, or no evidence of such bottlenecks. Nevertheless, males derived from polluted sites were able to reproduce successfully in competition with males derived from clean water exposures, indicating that these bottlenecks have not resulted in any substantial loss of reproductive fitness in males. Copyright © 2013 Elsevier B.V. All rights reserved.

Survey of fishes and environmental conditions in Abbotts Lagoon, Point Reyes National Seashore, California

Science.gov (United States)

Saiki, M.K.; Martin, B.A.

2001-01-01

This study was conducted to gain a better understanding of fishery resources in Abbotts Lagoon, Point Reyes National Seashore. During February/March, May, August, and November 1999, fish were sampled with floating variable-mesh gill nets and small minnow traps from as many as 14 sites in the lagoon. Water temperature, dissolved oxygen, pH, total ammonia(NH3 + NH4+), salinity, turbidity, water depth, and bottom substrate composition were also measured at each site. A total of 2,656 fish represented by eight species was captured during the study. Gill nets captured Sacramento perch, Archoplites interruptus; largemouth bass, Micropterus salmoides; Pacific herring, Clupea pallasi; prickly sculpin, Cottus asper, silver surfperch, Hyperprosopon ellipticum; longfin smelt, Spirinchus thaleichthys; and striped bass, Morone saxatilis; whereas minnow traps captured Sacramento perch; prickly sculpin; and threespine stickleback, Gasterosteus aculeatus. Cluster analysis (Ward's minimum variance method of fish catch statistics identified two major species assemblages-the first dominated by Sacramento perch and, to a lesser extent, by largemouth bass, and the second dominated by Pacific herring and threespine stickleback. Simple discriminant analysis of environmental variables indicated that salinity contributed the most towards separating the two assemblages.

Reproductive success in a natural population of male three-spined stickleback Gasterosteus aculeatus: effects of nuptial colour, parasites and body size.

Science.gov (United States)

Sparkes, T C; Rush, V; Kopp, D A; Foster, S A

2013-05-01

The effects of nuptial colour, parasites and body size on reproductive success were examined in a natural population of three-spined stickleback Gasterosteus aculeatus. Reproductive males were collected, with the contents of their nests, during the embryo-guarding stage from Lynne Lake (Cook Inlet, Alaska, U.S.A.), and nuptial colour, infection status and body size were recorded. Regression analysis revealed that male body size was the only predictor, of those measured, of reproductive success in nature. © 2013 The Authors. Journal of Fish Biology © 2013 The Fisheries Society of the British Isles.

Purifying Selection Maintains Dosage-Sensitive Genes during Degeneration of the Threespine Stickleback Y Chromosome

Science.gov (United States)

White, Michael A.; Kitano, Jun; Peichel, Catherine L.

2015-01-01

Sex chromosomes are subject to unique evolutionary forces that cause suppression of recombination, leading to sequence degeneration and the formation of heteromorphic chromosome pairs (i.e., XY or ZW). Although progress has been made in characterizing the outcomes of these evolutionary processes on vertebrate sex chromosomes, it is still unclear how recombination suppression and sequence divergence typically occur and how gene dosage imbalances are resolved in the heterogametic sex. The threespine stickleback fish (Gasterosteus aculeatus) is a powerful model system to explore vertebrate sex chromosome evolution, as it possesses an XY sex chromosome pair at relatively early stages of differentiation. Using a combination of whole-genome and transcriptome sequencing, we characterized sequence evolution and gene expression across the sex chromosomes. We uncovered two distinct evolutionary strata that correspond with known structural rearrangements on the Y chromosome. In the oldest stratum, only a handful of genes remain, and these genes are under strong purifying selection. By comparing sex-linked gene expression with expression of autosomal orthologs in an outgroup, we show that dosage compensation has not evolved in threespine sticklebacks through upregulation of the X chromosome in males. Instead, in the oldest stratum, the genes that still possess a Y chromosome allele are enriched for genes predicted to be dosage sensitive in mammals and yeast. Our results suggest that dosage imbalances may have been avoided at haploinsufficient genes by retaining function of the Y chromosome allele through strong purifying selection. PMID:25818858

The impact of selection, gene flow and demographic history on heterogeneous genomic divergence: three-spine sticklebacks in divergent environments.

Science.gov (United States)

Ferchaud, Anne-Laure; Hansen, Michael M

2016-01-01

Heterogeneous genomic divergence between populations may reflect selection, but should also be seen in conjunction with gene flow and drift, particularly population bottlenecks. Marine and freshwater three-spine stickleback (Gasterosteus aculeatus) populations often exhibit different lateral armour plate morphs. Moreover, strikingly parallel genomic footprints across different marine-freshwater population pairs are interpreted as parallel evolution and gene reuse. Nevertheless, in some geographic regions like the North Sea and Baltic Sea, different patterns are observed. Freshwater populations in coastal regions are often dominated by marine morphs, suggesting that gene flow overwhelms selection, and genomic parallelism may also be less pronounced. We used RAD sequencing for analysing 28 888 SNPs in two marine and seven freshwater populations in Denmark, Europe. Freshwater populations represented a variety of environments: river populations accessible to gene flow from marine sticklebacks and large and small isolated lakes with and without fish predators. Sticklebacks in an accessible river environment showed minimal morphological and genomewide divergence from marine populations, supporting the hypothesis of gene flow overriding selection. Allele frequency spectra suggested bottlenecks in all freshwater populations, and particularly two small lake populations. However, genomic footprints ascribed to selection could nevertheless be identified. No genomic regions were consistent freshwater-marine outliers, and parallelism was much lower than in other comparable studies. Two genomic regions previously described to be under divergent selection in freshwater and marine populations were outliers between different freshwater populations. We ascribe these patterns to stronger environmental heterogeneity among freshwater populations in our study as compared to most other studies, although the demographic history involving bottlenecks should also be considered in the

Acute exposure to offshore produced water has an effect on stress- and secondary stress responses in three-spined stickleback Gasterosteus aculeatus.

Science.gov (United States)

Knag, Anne Christine; Taugbøl, Annette

2013-09-01

Pollution is one of today's greatest problems, and the release of contaminants into the environment can cause adverse changes in vitally important biological pathways. In this study, we exposed three-spined stickleback Gasterosteus aculeatus to produced water (PW), i.e. wastewater from offshore petroleum production. PW contains substances such as alkylphenols (APs) and aromatic hydrocarbons (PAHs) known to induce toxicant stress and endocrine disruption in a variety of organisms. Following exposure to PW, a standardized confinement treatment was applied as a second stressor (PW-stress), testing how fish already under stress from the pollutant would respond to an additional stressor. The endpoint for analysis was a combination of blood levels of cortisol and glucose, in addition to transcribed levels of a set of genes related to toxicant stress, endocrine disruption and general stress. The findings of this study indicate that low doses of PW do not induce vitellogenin in immature female stickleback, but do cause an upregulation of cytochrome (CYP1A) and UDP-glucuronsyltransferase (UDP-GT), two biomarkers related to toxicant stress. However, when the second stressor was applied, both genes were downregulated, indicating that the confinement exposure had a suppressive effect on the expression of toxicant biomarkers (CYP1A and UDP-GT). Further, two of the stress related genes, heat shock protein 90 (HSP90) and stress-induced phosphoprotein (STIP), were upregulated in both PW- and PW-stress-treatment, but not in the water control confinement treatment, indicating that PW posed as a larger stress-factor than confinement for these genes. The confinement stressor caused an increased level of glucose in both control and PW-treated fish, indicating hyperglycemia, a commonly reported stress response in fish. © 2013.

Evaluation of chlorpyrifos effects, alone and combined with lipopolysaccharide stress, on DNA integrity and immune responses of the three-spined stickleback, Gasterosteus aculeatus.

Science.gov (United States)

Marchand, Adrien; Porcher, Jean-Marc; Turies, Cyril; Chadili, Edith; Palluel, Olivier; Baudoin, Patrick; Betoulle, Stéphane; Bado-Nilles, Anne

2017-11-01

Organism immune defences might be weakened by pollutants, largely detected in aquatic ecosystems, leading to the facilitation for opportunistic pathogens to infect organisms. In this context, destabilization of fish non-specific immune parameters and erythrocyte DNA integrity was tested, on a model fish species, the three-spined stickleback (Gasterosteus aculeatus), after exposure to chlorpyrifos (CPF). Alone, pesticide exposure induced a genotoxic potential (chlorpyrifos at 1.75 and 0.88µg/L) in addition to a decrease in phagocytosis capacity and a stimulation of respiratory burst. Then, to mimic pathogenic infection, fish exposure to chlorpyrifos was combined with lipopolysaccharides (LPS) stress. In this second experiment, an increase of DNA damage was observed in fish exposed to a lower concentration of chlorpyrifos and LPS. Moreover, at the higher concentration of chlorpyrifos, an early destabilization of innate immunity was observed as suggested by the absence of an increase of lysosomal presence in fish injected with LPS. This study highlighted the usefulness of stress on stress responses to better understand the impact of contaminants on the organism's health. Copyright © 2017 Elsevier Inc. All rights reserved.

Nutritional benefits of filial cannibalism in three-spined sticklebacks ( Gasterosteus aculeatus)

Science.gov (United States)

Mehlis, Marion; Bakker, Theo C. M.; Frommen, Joachim G.

2009-03-01

Although filial cannibalism (eating one’s own offspring) occurs in numerous species, including several teleost fishes, its adaptive value is still not well understood. One often-discussed explanation is that individuals enhance their mass and body condition by consuming part of their eggs. However, evidence for this assumption is scarce thus far. In this study, male three-spined sticklebacks ( Gasterosteus aculeatus), a species with paternal care, were allowed to care for a batch of eggs or for an empty nest under food-deprived conditions. All brood-caring males cannibalised at least part of their eggs and thus preserved their initial mass and body condition. Furthermore, mass as well as body condition was significant positively correlated with the number of cannibalised eggs. In contrast, empty-nest males that had no possibility to cannibalise eggs significantly lost mass and body condition. This is, to our knowledge, the first experimentally documented evidence that mass as well as body condition were preserved by filial cannibalism.

The ecology of an adaptive radiation of three-spined stickleback from North Uist, Scotland.

Science.gov (United States)

Magalhaes, Isabel S; D'Agostino, Daniele; Hohenlohe, Paul A; MacColl, Andrew D C

2016-09-01

There has been a large focus on the genetics of traits involved in adaptation, but knowledge of the environmental variables leading to adaptive changes is surprisingly poor. Combined use of environmental data with morphological and genomic data should allow us to understand the extent to which patterns of phenotypic and genetic diversity within a species can be explained by the structure of the environment. Here, we analyse the variation of populations of three-spined stickleback from 27 freshwater lakes on North Uist, Scotland, that vary greatly in their environment, to understand how environmental and genetic constraints contribute to phenotypic divergence. We collected 35 individuals per population and 30 abiotic and biotic environmental parameters to characterize variation across lakes and analyse phenotype-environment associations. Additionally, we used RAD sequencing to estimate the genetic relationships among a subset of these populations. We found a large amount of phenotypic variation among populations, most prominently in armour and spine traits. Despite large variation in the abiotic environment, namely in ion composition, depth and dissolved organic Carbon, more phenotypic variation was explained by the biotic variables (presence of predators and density of predator and competitors), than by associated abiotic variables. Genetic structure among populations was partly geographic, with closer populations being more similar. Altogether, our results suggest that differences in body shape among stickleback populations are the result of both canalized genetic and plastic responses to environmental factors, which shape fish morphology in a predictable direction regardless of their genetic starting point. © 2016 The Authors. Molecular Ecology Published by John Wiley & Sons Ltd.

Environmental monitoring of the Robertson Reservoir (1990-2005) : evolution of the mercury levels in the flesh of fish

International Nuclear Information System (INIS)

Therrien, J.

2006-04-01

This paper provided details of an environmental monitoring analysis of the stomach contents and mercury levels in the flesh of main fish species in the Robertson Reservoir. The report noted that smelt species were dominant in the reservoir and in the adjoining Ivry Lake, while benthos were dominant the brackish waters of Lake Monger. Sticklebacks were found in the stomachs of the examined fish, while the diet of brook trout was comprised mainly of benthos in lakes and reservoirs. Arctic char mainly ate benthos in the reservoir. Landlocked salmon mainly ate fish in the reservoirs and lakes. Smelt was the primary diet of Arctic char until 2003. After 2003, Arctic char fed mainly on sticklebacks. It was observed that average mercury levels of fish of a standardized length increased by a factor of 2.7 to 4.9 after the impoundment of the reservoir. However, average mercury levels stopped increasing for dwarf Arctic char in 2003. Levels of mercury in brook trout have not increased since 1999. A significant decrease in mercury levels of rainbow smelt were observed. Average mercury levels of fish in the brackish waters of Lake Monger were lower than levels observed in most other freshwater lakes in the region. It was concluded that the number of monthly meals recommended by the fish consumption guide produced in 2001 for the Gros Mecatina region are still appropriate for the reservoir

anyFish 2.0: An open-source software platform to generate and share animated fish models to study behavior

Directory of Open Access Journals (Sweden)

Spencer J. Ingley

2015-12-01

Full Text Available Experimental approaches to studying behaviors based on visual signals are ubiquitous, yet these studies are limited by the difficulty of combining realistic models with the manipulation of signals in isolation. Computer animations are a promising way to break this trade-off. However, animations are often prohibitively expensive and difficult to program, thus limiting their utility in behavioral research. We present anyFish 2.0, a user-friendly platform for creating realistic animated 3D fish. anyFish 2.0 dramatically expands anyFish’s utility by allowing users to create animations of members of several groups of fish from model systems in ecology and evolution (e.g., sticklebacks, Poeciliids, and zebrafish. The visual appearance and behaviors of the model can easily be modified. We have added several features that facilitate more rapid creation of realistic behavioral sequences. anyFish 2.0  provides a powerful tool that will be of broad use in animal behavior and evolution and serves as a model for transparency, repeatability, and collaboration.

Reciprocal cross infection of sticklebacks with the diphyllobothriidean cestode Schistocephalus solidus reveals consistent population differences in parasite growth and host resistance.

Science.gov (United States)

Kalbe, Martin; Eizaguirre, Christophe; Scharsack, Jörn P; Jakobsen, Per J

2016-03-08

In host-parasite evolutionary arms races, parasites are generally expected to adapt more rapidly, due to their large population sizes and short generation times. There exist systems, though, where parasites cannot outpace their hosts because of similar generation times in both antagonists. In those cases concomitant adaptation is expected. We tested this hypothesis in the three-spined stickleback-Schistocephalus solidus tapeworm system, where generation times are comparable in both organisms. We chose two populations of sticklebacks which differ prominently in the prevalence of S. solidus and consequently in its level of selective pressure. We performed a full factorial common garden experiment. Particularly, Norwegian (NO) and German (DE) sticklebacks, as well as hybrids between both stickleback populations and in both parental combinations, were exposed each to a single S. solidus originating from the same two host populations. We found the infection phenotype to depend on the host population, the parasite population, but not their interaction. NO-parasites showed higher infectivity than DE-parasites, with NO-sticklebacks also being more resistant to DE-parasites than to the sympatric NO-parasite. Reciprocally, DE-hosts were more susceptible to the allopatric NO-parasite while DE-parasites grew less than NO-parasites in all stickleback groups. Despite this asymmetry, the ratio of worm to host weight, an indicator of parasite virulence, was identical in both sympatric combinations, suggesting an optimal virulence as a common outcome of parallel coevolved systems. In hybrid sticklebacks, intermediate infection rates and growth of S. solidus from either origin suggests a simple genetic basis of resistance. However, comparison of infection phenotypes in NO-maternal and DE-maternal hybrid sticklebacks indicates local adaptation to the sympatric counterpart in both the host and the parasite. Host-parasite systems with similar generation time show evidence for

Prey fish returned to Forster's tern colonies suggest spatial and temporal differences in fish composition and availability.

Science.gov (United States)

Peterson, Sarah H; Ackerman, Joshua T; Eagles-Smith, Collin A; Herzog, Mark P; Hartman, C Alex

2018-01-01

Predators sample the available prey community when foraging; thus, changes in the environment may be reflected by changes in predator diet and foraging preferences. We examined Forster's tern (Sterna forsteri) prey species over an 11-year period by sampling approximately 10,000 prey fish returned to 17 breeding colonies in south San Francisco Bay, California. We compared the species composition among repeatedly-sampled colonies (≥ 4 years), using both relative species abundance and the composition of total dry mass by species. Overall, the relative abundances of prey species at seven repeatedly-sampled tern colonies were more different than would be expected by chance, with the most notable differences in relative abundance observed between geographically distant colonies. In general, Mississippi silverside (Menidia audens) and topsmelt silverside (Atherinops affinis) comprised 42% of individuals and 40% of dry fish mass over the study period. Three-spined stickleback (Gasterosteus aculeatus) comprised the next largest proportion of prey species by individuals (19%) but not by dry mass (6%). Five additional species each contributed ≥ 4% of total individuals collected over the study period: yellowfin goby (Acanthogobius flavimanus; 10%), longjaw mudsucker (Gillichthys mirabilis; 8%), Pacific herring (Clupea pallasii; 6%), northern anchovy (Engraulis mordax; 4%), and staghorn sculpin (Leptocottus armatus; 4%). At some colonies, the relative abundance and biomass of specific prey species changed over time. In general, the abundance and dry mass of silversides increased, whereas the abundance and dry mass of three-spined stickleback and longjaw mudsucker decreased. As central place foragers, Forster's terns are limited in the distance they forage; thus, changes in the prey species returned to Forster's tern colonies suggest that the relative availability of some fish species in the environment has changed, possibly in response to alteration of the available habitat.

The effects of the painkiller diclofenac and hypoxia on gene transcription and antioxidant system in the gills of three-spined stickleback.

Science.gov (United States)

Lubiana, Pedro; Prokkola, Jenni M; Nikinmaa, Mikko; Burmester, Thorsten; Kanerva, Mirella; Götting, Miriam

2016-01-01

Aquatic organisms face multiple stressors in natural ecosystems. More and more often painkillers are detected in surface waters since their prescription has increased worldwide within the last years. Here we examined the effects of the non-steroidal anti-inflammatory drug (NSAID) diclofenac and hypoxia on three-spined sticklebacks (Gasterosteus aculeatus). We exposed sticklebacks to an environmentally relevant concentration of diclofenac (1μg/L) for 14days, to 24h of hypoxia (2.0mg O2/L), and a combination of both. Hypoxia and diclofenac both can be associated with oxidative stress in fish, but it is unclear whether they would act synergistically. Expression analysis of genes related to antioxidant response, hypoxia response, and chemical metabolism in gills showed that diclofenac alone had little effect, while the combination of hypoxia and diclofenac affected transcript levels most, indicating synergistic effects of these stressors. Of the antioxidant enzymes, only superoxide dismutase activity remained unchanged by treatments, while glutathione peroxidase (GPx) was the most affected antioxidant response on both the transcript and activity levels. Our results suggest that diclofenac may lead to suppressed catalase (CAT) activity but increased GPx activity, probably as compensatory mechanism to remove increasing H2O2 in the gills, and that this response is not affected by hypoxia. The activities of lactate dehydrogenase, CAT, and GPx also showed temporal variability during treatments, which can be attributable to tissue-specific circadian rhythms. Our study shows how responses to NSAIDs and hypoxia can interact in fish, suggesting that getting more insight into temporal variation and about the different levels of regulation of environmental responses is necessary in future studies. Copyright © 2016. Published by Elsevier Inc.

Historical contingency and ecological determinism interact to prime speciation in sticklebacks, Gasterosteus.

Science.gov (United States)

Taylor, E B; McPhail, J D

2000-01-01

Historical contingency and determinism are often cast as opposing paradigms under which evolutionary diversification operates. It may be, however, that both factors act together to promote evolutionary divergence, although there are few examples of such interaction in nature. We tested phylogenetic predictions of an explicit historical model of divergence (double invasions of freshwater by marine ancestors) in sympatric species of three-spined sticklebacks (Gasterosteus aculeatus) where determinism has been implicated as an important factor driving evolutionary novelty. Microsatellite DNA variation at six loci revealed relatively low genetic variation in freshwater populations, supporting the hypothesis that they were derived by colonization of freshwater by more diverse marine ancestors. Phylogenetic and genetic distance analyses suggested that pairs of sympatric species have evolved multiple times, further implicating determinism as a factor in speciation. Our data also supported predictions based on the hypothesis that the evolution of sympatric species was contingent upon 'double invasions' of postglacial lakes by ancestral marine sticklebacks. Sympatric sticklebacks, therefore, provide an example of adaptive radiation by determinism contingent upon historical conditions promoting unique ecological interactions, and illustrate how contingency and determinism may interact to generate geographical variation in species diversity PMID:11133026

Geography of the circadian gene clock and photoperiodic response in western North American populations of the three-spined stickleback Gasterosteus aculeatus.

Science.gov (United States)

O'Brien, C; Unruh, L; Zimmerman, C; Bradshaw, W E; Holzapfel, C M; Cresko, W A

2013-03-01

Controlled laboratory experiments were used to show that Oregon and Alaskan three-spined stickleback Gasterosteus aculeatus, collected from locations differing by 18° of latitude, exhibited no significant variation in length of the polyglutamine domain of the clock protein or in photoperiodic response within or between latitudes despite the fact that male and female G. aculeatus are photoperiodic at both latitudes. Hence, caution is urged when interpreting variation in the polyglutamine repeat (PolyQ) domain of the gene clock in the context of seasonal activities or in relationship to photoperiodism along geographical gradients. © 2013 The Authors. Journal of Fish Biology © 2013 The Fisheries Society of the British Isles.

Prey fish returned to Forster’s tern colonies suggest spatial and temporal differences in fish composition and availability

Science.gov (United States)

Peterson, Sarah; Ackerman, Joshua T.; Eagles-Smith, Collin A.; Herzog, Mark; Hartman, C. Alex

2018-01-01

Predators sample the available prey community when foraging; thus, changes in the environment may be reflected by changes in predator diet and foraging preferences. We examined Forster’s tern (Sterna forsteri) prey species over an 11-year period by sampling approximately 10,000 prey fish returned to 17 breeding colonies in south San Francisco Bay, California. We compared the species composition among repeatedly-sampled colonies (≥ 4 years), using both relative species abundance and the composition of total dry mass by species. Overall, the relative abundances of prey species at seven repeatedly-sampled tern colonies were more different than would be expected by chance, with the most notable differences in relative abundance observed between geographically distant colonies. In general, Mississippi silverside (Menidia audens) and topsmelt silverside (Atherinops affinis) comprised 42% of individuals and 40% of dry fish mass over the study period. Three-spined stickleback (Gasterosteus aculeatus) comprised the next largest proportion of prey species by individuals (19%) but not by dry mass (6%). Five additional species each contributed ≥ 4% of total individuals collected over the study period: yellowfin goby (Acanthogobius flavimanus; 10%), longjaw mudsucker (Gillichthys mirabilis; 8%), Pacific herring (Clupea pallasii; 6%), northern anchovy (Engraulis mordax; 4%), and staghorn sculpin (Leptocottus armatus; 4%). At some colonies, the relative abundance and biomass of specific prey species changed over time. In general, the abundance and dry mass of silversides increased, whereas the abundance and dry mass of three-spined stickleback and longjaw mudsucker decreased. As central place foragers, Forster’s terns are limited in the distance they forage; thus, changes in the prey species returned to Forster’s tern colonies suggest that the relative availability of some fish species in the environment has changed, possibly in response to alteration of the available

Identification of major and minor QTL for ecologically important morphological traits in three-spined sticklebacks (Gasterosteus aculeatus).

Science.gov (United States)

Liu, Jun; Shikano, Takahito; Leinonen, Tuomas; Cano, José Manuel; Li, Meng-Hua; Merilä, Juha

2014-04-16

Quantitative trait locus (QTL) mapping studies of Pacific three-spined sticklebacks (Gasterosteus aculeatus) have uncovered several genomic regions controlling variability in different morphological traits, but QTL studies of Atlantic sticklebacks are lacking. We mapped QTL for 40 morphological traits, including body size, body shape, and body armor, in a F2 full-sib cross between northern European marine and freshwater three-spined sticklebacks. A total of 52 significant QTL were identified at the 5% genome-wide level. One major QTL explaining 74.4% of the total variance in lateral plate number was detected on LG4, whereas several major QTL for centroid size (a proxy for body size), and the lengths of two dorsal spines, pelvic spine, and pelvic girdle were mapped on LG21 with the explained variance ranging from 27.9% to 57.6%. Major QTL for landmark coordinates defining body shape variation also were identified on LG21, with each explaining ≥15% of variance in body shape. Multiple QTL for different traits mapped on LG21 overlapped each other, implying pleiotropy and/or tight linkage. Thus, apart from providing confirmatory data to support conclusions born out of earlier QTL studies of Pacific sticklebacks, this study also describes several novel QTL of both major and smaller effect for ecologically important traits. The finding that many major QTL mapped on LG21 suggests that this linkage group might be a hotspot for genetic determinants of ecologically important morphological traits in three-spined sticklebacks.

A low-density SNP array for analyzing differential selection in freshwater and marine populations of threespine stickleback (Gasterosteus aculeatus).

Science.gov (United States)

Ferchaud, Anne-Laure; Pedersen, Susanne H; Bekkevold, Dorte; Jian, Jianbo; Niu, Yongchao; Hansen, Michael M

2014-10-06

The threespine stickleback (Gasterosteus aculeatus) has become an important model species for studying both contemporary and parallel evolution. In particular, differential adaptation to freshwater and marine environments has led to high differentiation between freshwater and marine stickleback populations at the phenotypic trait of lateral plate morphology and the underlying candidate gene Ectodysplacin (EDA). Many studies have focused on this trait and candidate gene, although other genes involved in marine-freshwater adaptation may be equally important. In order to develop a resource for rapid and cost efficient analysis of genetic divergence between freshwater and marine sticklebacks, we generated a low-density SNP (Single Nucleotide Polymorphism) array encompassing markers of chromosome regions under putative directional selection, along with neutral markers for background. RAD (Restriction site Associated DNA) sequencing of sixty individuals representing two freshwater and one marine population led to the identification of 33,993 SNP markers. Ninety-six of these were chosen for the low-density SNP array, among which 70 represented SNPs under putatively directional selection in freshwater vs. marine environments, whereas 26 SNPs were assumed to be neutral. Annotation of these regions revealed several genes that are candidates for affecting stickleback phenotypic variation, some of which have been observed in previous studies whereas others are new. We have developed a cost-efficient low-density SNP array that allows for rapid screening of polymorphisms in threespine stickleback. The array provides a valuable tool for analyzing adaptive divergence between freshwater and marine stickleback populations beyond the well-established candidate gene Ectodysplacin (EDA).

Effects of offshore wind power on the pelagic fish; Effekter av havsbaserad vindkraft paa pelagisk fisk

Energy Technology Data Exchange (ETDEWEB)

Axenrot, Thomas (SLU, Institutionen foer Akvatiska Resurser, Soetvattenlaboratoriet (Sweden)); Didrikas, Tomas (AquaBiota Water Research AB (Sweden); Stockholms universitet (Sweden))

2012-02-15

Marine wind parks are being planned for and built in coastal and shallow offshore areas in response to an increasing demand for renewable energy. Today's knowledge is limited about possible effects on fish from habitat change and generated underwater sound when wind parks are running. There may also be consequences for the fishery. Studies on fish hearing have shown that many fishes hear low frequency sound like that produced by wind turbines. This study consists of two parts. The first part of the study investigated pelagic fish abundance and spatial distribution at one wind park and two reference areas (200 m to 10 km distance from fundaments) at five different occasions from 2005 through 2007 in the Kalmar Sound of the Baltic Sea. The highest fish densities was found in the most remote reference area. The difference between areas was statistically significant for fish of the size groups 30-80 mm (stickleback), 80-140 mm (sprat, small herring) and 140-250 mm (adult herring). For fish >250 mm, representing cod and salmon, no statistically significant difference between areas was observed. For one group (sticklebacks) Area was significantly pointed out as the most important factor for the observed differences in fish density. No data on fish densities in the investigated areas were collected before the wind park (Utgrunden 1) was built which is a drawback to this part of the study. The second part of the study focused on possible effects of underwater sound generated by wind turbines on fish behaviour in the close vicinity of the fundaments (2-35 m distance). Stationary horizontal acoustics was used to estimate fish abundance and swimming speed in relation to turbine rotor speed and electricity production. The changes of abundance were not consistent and difficult to interpret. Fish swimming speed decreased with increasing turbine rotor speed and electricity production. However, it cannot be distinguished if this was an effect of sound emitted by wind turbines

A role for a neo-sex chromosome in stickleback speciation

Science.gov (United States)

Kitano, Jun; Ross, Joseph A.; Mori, Seiichi; Kume, Manabu; Jones, Felicity C.; Chan, Yingguang F.; Absher, Devin M.; Grimwood, Jane; Schmutz, Jeremy; Myers, Richard M.; Kingsley, David M.; Peichel, Catherine L.

2009-01-01

Sexual antagonism, or conflict between the sexes, has been proposed as a driving force in both sex chromosome turnover and speciation. Although closely related species often have different sex chromosome systems, it is unknown whether sex chromosome turnover contributes to the evolution of reproductive isolation between species. In this study, we show that a newly evolved sex chromosome harbours genes that contribute to speciation in threespine stickleback fish (Gasterosteus aculeatus). We first identified a neo-sex chromosome system found only in one member of a sympatric species pair in Japan. We then performed genetic linkage mapping of male-specific traits important for reproductive isolation between the Japanese species pair. The neo-X chromosome harbours loci for male courtship display traits that contribute to behavioural isolation, while the ancestral X chromosome contains loci for both behavioural isolation and hybrid male sterility. Our work not only provides strong evidence for a large-X effect on reproductive isolation in a vertebrate system, but also provides direct evidence that a young neo-X chromosome contributes to reproductive isolation between closely related species. Our data suggest that sex chromosome turnover might play a greater role in speciation than previously appreciated. PMID:19783981

Conspicuous female ornamentation and tests of male mate preference in threespine sticklebacks (Gasterosteus aculeatus.

Directory of Open Access Journals (Sweden)

Daniel Shane Wright

Full Text Available Sexual selection drives the evolution of exaggerated male ornaments in many animal species. Female ornamentation is now acknowledged also to be common but is generally less well understood. One example is the recently documented red female throat coloration in some threespine stickleback (Gasterosteus aculeatus populations. Although female sticklebacks often exhibit a preference for red male throat coloration, the possibility of sexual selection on female coloration has been little studied. Using sequential and simultaneous mate choice trials, we examined male mate preferences for female throat color, as well as pelvic spine color and standard length, using wild-captured threespine sticklebacks from the Little Campbell River, British Columbia. In a multivariate analysis, we found no evidence for a population-level mate preference in males, suggesting the absence of directional sexual selection on these traits arising from male mate choice. Significant variation was detected among males in their preference functions, but this appeared to arise from differences in their mean responsiveness across mating trials and not from variation in the strength (i.e., slope of their preference, suggesting the absence of individual-level preferences as well. When presented with conspecific intruder males, male response decreased as intruder red throat coloration increased, suggesting that males can discriminate color and other aspects of phenotype in our experiment and that males may use these traits in intrasexual interactions. The results presented here are the first to explicitly address male preference for female throat color in threespine sticklebacks.

Conspicuous female ornamentation and tests of male mate preference in threespine sticklebacks (Gasterosteus aculeatus).

Science.gov (United States)

Wright, Daniel Shane; Pierotti, Michele E R; Rundle, Howard D; McKinnon, Jeffrey S

2015-01-01

Sexual selection drives the evolution of exaggerated male ornaments in many animal species. Female ornamentation is now acknowledged also to be common but is generally less well understood. One example is the recently documented red female throat coloration in some threespine stickleback (Gasterosteus aculeatus) populations. Although female sticklebacks often exhibit a preference for red male throat coloration, the possibility of sexual selection on female coloration has been little studied. Using sequential and simultaneous mate choice trials, we examined male mate preferences for female throat color, as well as pelvic spine color and standard length, using wild-captured threespine sticklebacks from the Little Campbell River, British Columbia. In a multivariate analysis, we found no evidence for a population-level mate preference in males, suggesting the absence of directional sexual selection on these traits arising from male mate choice. Significant variation was detected among males in their preference functions, but this appeared to arise from differences in their mean responsiveness across mating trials and not from variation in the strength (i.e., slope) of their preference, suggesting the absence of individual-level preferences as well. When presented with conspecific intruder males, male response decreased as intruder red throat coloration increased, suggesting that males can discriminate color and other aspects of phenotype in our experiment and that males may use these traits in intrasexual interactions. The results presented here are the first to explicitly address male preference for female throat color in threespine sticklebacks.

The role of calcium and predation on plate morph evolution in the three-spined stickleback (Gasterosteus aculeatus).

Science.gov (United States)

Smith, Carl; Spence, Rowena; Barber, Iain; Przybylski, Mirosław; Wootton, Robert J

2014-09-01

While the genetic basis to plate morph evolution of the three-spined stickleback (Gasterosteus aculeatus) is well described, the environmental variables that select for different plate and spine morphs are incompletely understood. Using replicate populations of three-spined sticklebacks on North Uist, Scotland, we previously investigated the role of predation pressure and calcium limitation on the adaptive evolution of stickleback morphology and behavior. While dissolved calcium proved a significant predictor of plate and spine morph, predator abundance did not. Ecol. Evol., xxx, 2014 and xxx performed a comparable analysis to our own to address the same question. They failed to detect a significant effect of dissolved calcium on morphological evolution, but did establish a significant effect of predation; albeit in the opposite direction to their prediction.

Parasites contribute to ecologically dependent postmating isolation in the adaptive radiation of three-spined stickleback.

Science.gov (United States)

El Nagar, Aliya; MacColl, Andrew D C

2016-08-17

Spatial variation in parasitic infections is common, and has the potential to drive population divergence and the reproductive isolation of hosts. However, despite support from theory and model laboratory systems, little strong evidence has been forthcoming from the wild. Here, we show that parasites are likely to cause reproductive isolation in the adaptive radiation of three-spined stickleback. Adjacent wild populations on the Scottish island of North Uist differ greatly and consistently in the occurrence of different parasites that have substantial effects on fitness. Laboratory-reared fish are more resistant to experimental infection by parasite species from their own population. Furthermore, hybrid backcrosses between the host populations are more resistant to parasites from the parental population to which they are more closely related. These patterns provide strong evidence that parasites can cause ecological speciation, by contributing to selection against migrants and ecologically dependent postmating isolation. © 2016 The Author(s).

Variation in Lateral Plate Quality in Threespine Stickleback from Fresh, Brackish and Marine Water: A Micro-Computed Tomography Study.

Directory of Open Access Journals (Sweden)

Elisabeth Wiig

Full Text Available It is important to understand the drivers leading to adaptive phenotypic diversity within and among species. The threespine stickleback (Gasterosteus aculeatus has become a model system for investigating the genetic and phenotypic responses during repeated colonization of fresh waters from the original marine habitat. During the freshwater colonization process there has been a recurrent and parallel reduction in the number of lateral bone plates, making it a suitable system for studying adaptability and parallel evolution.The aim of this study was to investigate an alternative evolutionary path of lateral plate reduction, where lateral plates are reduced in size rather than number.A total of 72 threespine stickleback individuals from freshwater (n = 54, brackish water (n = 27 and marine water (n = 9 were analysed using microcomputed tomography (μCT to determine variation in size, thickness and structure of the lateral plates. Furthermore, whole-body bone volume, and bone volume, bone surface and porosity of lateral plate number 4 were quantified in all specimens from each environment.The results showed a significant difference in plate size (area and volume among populations, where threespine stickleback from polymorphic freshwater and brackish water populations displayed lateral plates reduced in size (area and volume compared to marine stickleback.Reduction of lateral plates in threespine stickleback in fresh and brackish water occurs by both plate loss and reduction in plate size (area and volume.

Invasion of top and intermediate consumers in a size structured fish community

OpenAIRE

Ask, Per

2010-01-01

In this thesis I have investigated the effects of invading top and intermediate consumers in a size-structured fish community, using a combination of field studies, a lake invasion experiment and smaller scale pond and aquaria experiments. The lake invasion experiment was based on introductions of an intermediate consumer, ninespine stickleback (Pungitius pungitius L.), in to allopatric populations of an omnivorous top predator, Arctic char (Salvelinus alpinus L.). The invasion experiment was...

Studies on the toxicity of cadmium to the three-spined stickleback Gasterosteus aculeatus L

Energy Technology Data Exchange (ETDEWEB)

Pascoe, D.; Mattey, D.L.

1977-08-01

Cadmium was found to be lethal to sticklebacks at all concentrations from 100.0 to 0.001 mg Cd l/sup -1/, in water of 103-111 mg l/sup -1/ hardness as CaCO/sub 3/. The pattern of mortality as shown by the time-concentration curve suggests that toxicity is not due to a single mechanism but changes with concentration. Fish were found to accumulate cadmium, the whole body levels incrasing from 0.90 ..mu..g/g fresh weight at 0.001 mg Cd l/sup -1/ exposure concentration to 51.0 ..mu..g/g at 100 mg Cd l/sup -1/. The concentration factor was shown to decrease with increasing exposure concentration from 0.51 at 100 mg Cd l/sup -1/ to 511 at 0.001 mg Cd l/sup -1/. The plerocercoid parasite Schistocephalus solidus in the host's perivisceral cavity contained less cadmium than the tissues of its host.

Sympatric and allopatric divergence of MHC genes in threespine stickleback.

Directory of Open Access Journals (Sweden)

Blake Matthews

2010-06-01

Full Text Available Parasites can strongly affect the evolution of their hosts, but their effects on host diversification are less clear. In theory, contrasting parasite communities in different foraging habitats could generate divergent selection on hosts and promote ecological speciation. Immune systems are costly to maintain, adaptable, and an important component of individual fitness. As a result, immune system genes, such as those of the Major Histocompatibility Complex (MHC, can change rapidly in response to parasite-mediated selection. In threespine stickleback (Gasterosteus aculeatus, as well as in other vertebrates, MHC genes have been linked with female mating preference, suggesting that divergent selection acting on MHC genes might influence speciation. Here, we examined genetic variation at MHC Class II loci of sticklebacks from two lakes with a limnetic and benthic species pair, and two lakes with a single species. In both lakes with species pairs, limnetics and benthics differed in their composition of MHC alleles, and limnetics had fewer MHC alleles per individual than benthics. Similar to the limnetics, the allopatric population with a pelagic phenotype had few MHC alleles per individual, suggesting a correlation between MHC genotype and foraging habitat. Using a simulation model we show that the diversity and composition of MHC alleles in a sympatric species pair depends on the amount of assortative mating and on the strength of parasite-mediated selection in adjacent foraging habitats. Our results indicate parallel divergence in the number of MHC alleles between sympatric stickleback species, possibly resulting from the contrasting parasite communities in littoral and pelagic habitats of lakes.

Body armour and lateral-plate reduction in freshwater three-spined stickleback Gasterosteus aculeatus: adaptations to a different buoyancy regime?

Science.gov (United States)

Myhre, F; Klepaker, T

2009-11-01

Several factors related to buoyancy were compared between one marine and two freshwater populations of three-spined stickleback Gasterosteus aculeatus. Fish from all three populations had buoyancy near to neutral to the ambient water. This showed that neither marine nor freshwater G. aculeatus used swimming and hydrodynamic lift to prevent sinking. Comparing the swimbladder volumes showed that freshwater completely plated G. aculeatus had a significantly larger swimbladder volume than both completely plated marine and low-plated freshwater G. aculeatus. Furthermore, body tissue density was lower in low-plated G. aculeatus than in the completely plated marine and freshwater fish. The results show that G. aculeatus either reduce tissue density or increase swimbladder volume to adapt to lower water density. Mass measurements of lateral plates and pelvis showed that loss of body armour in low-plated G. aculeatus could explain the tissue density difference between low-plated and completely plated G. aculeatus. This suggests that the common occurrence of plate and armour reduction in freshwater G. aculeatus populations can be an adaptation to a lower water density.

Paternal care in a fish: epigenetics and fitness enhancing effects on offspring anxiety

OpenAIRE

McGhee, Katie E.; Bell, Alison M.

2014-01-01

In many animals, including humans, interactions with caring parents can have long-lasting effects on offspring sensitivity to stressors. However, whether these parental effects impact offspring fitness in nature is often unclear. In addition, despite evidence that maternal care can influence offspring behaviour via epigenetic alterations to the genome, it remains unclear whether paternal care has similar effects. Here, we show in three-spined sticklebacks, a fish in which fathers are the sole...

No evidence of local adaptation of immune responses to Gyrodactylus in three-spined stickleback (Gasterosteus aculeatus).

Science.gov (United States)

Robertson, Shaun; Bradley, Janette E; MacColl, Andrew D C

2017-01-01

Parasitism represents one of the most widespread lifestyles in the animal kingdom, with the potential to drive coevolutionary dynamics with their host population. Where hosts and parasites evolve together, we may find local adaptation. As one of the main host defences against infection, there is the potential for the immune response to be adapted to local parasites. In this study, we used the three-spined stickleback and its Gyrodactylus parasites to examine the extent of local adaptation of parasite infection dynamics and the immune response to infection. We took two geographically isolated host populations infected with two distinct Gyrodactylus species and performed a reciprocal cross-infection experiment in controlled laboratory conditions. Parasite burdens were monitored over the course of the infection, and individuals were sampled at multiple time points for immune gene expression analysis. We found large differences in virulence between parasite species, irrespective of host, and maladaptation of parasites to their sympatric host. The immune system responded to infection, with a decrease in expression of innate and Th1-type adaptive response genes in fish infected with the less virulent parasite, representing a marker of a possible resistance mechanism. There was no evidence of local adaptation in immune gene expression levels. Our results add to the growing understanding of the extent of host-parasite local adaptation, and demonstrate a systemic immune response during infection with a common ectoparasite. Further immunological studies using the stickleback-Gyrodactylus system can continue to contribute to our understanding of the function of the immune response in natural populations. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

Heat and immunity: an experimental heat wave alters immune functions in three-spined sticklebacks (Gasterosteus aculeatus).

Science.gov (United States)

Dittmar, Janine; Janssen, Hannah; Kuske, Andra; Kurtz, Joachim; Scharsack, Jörn P

2014-07-01

Global climate change is predicted to lead to increased temperatures and more extreme climatic events. This may influence host-parasite interactions, immunity and therefore the impact of infectious diseases on ecosystems. However, little is known about the effects of rising temperatures on immune defence, in particular in ectothermic animals, where the immune system is directly exposed to external temperature change. Fish are ideal models for studying the effect of temperature on immunity, because they are poikilothermic, but possess a complete vertebrate immune system with both innate and adaptive immunity. We used three-spined sticklebacks ( Gasterosteus aculeatus) originating from a stream and a pond, whereby the latter supposedly were adapted to higher temperature variation. We studied the effect of increasing and decreasing temperatures and a simulated heat wave with subsequent recovery on body condition and immune parameters. We hypothesized that the immune system might be less active at low temperatures, but will be even more suppressed at temperatures towards the upper tolerable temperature range. Contrary to our expectation, we found innate and adaptive immune activity to be highest at a temperature as low as 13 °C. Exposure to a simulated heat wave induced long-lasting immune disorders, in particular in a stickleback population that might be less adapted to temperature variation in its natural environment. The results show that the activity of the immune system of an ectothermic animal species is temperature dependent and suggest that heat waves associated with global warming may immunocompromise host species, thereby potentially facilitating the spread of infectious diseases. © 2014 The Authors. Journal of Animal Ecology © 2014 British Ecological Society.

Genetic divergence of a sympatric lake-resident-anadromous three-spined stickleback Gasterosteus aculeatus species pair.

Science.gov (United States)

Drevecky, C J; Falco, R; Aguirre, W E

2013-07-01

The genetic relationship between sympatric, morphologically divergent populations of anadromous and lake-resident three-spined stickleback Gasterosteus aculeatus in the Jim Creek drainage of Cook Inlet, Alaska, was examined using microsatellite loci and mitochondrial d-loop sequence data. Resident samples differed substantially from sympatric anadromous samples in the Jim Creek drainage with the magnitude of the genetic divergence being similar to that between allopatric resident and anadromous populations in other areas. Resident samples were genetically similar within the Jim Creek drainage, as were the anadromous samples surveyed. Neighbour-joining and Structure cluster analysis grouped the samples into four genetic clusters by ecomorph (anadromous v. all resident) and geographic location of the resident samples (Jim Creek, Mat-Su and Kenai). There was no evidence of hybridization between resident and anadromous G. aculeatus in the Jim Creek drainage, which thus appear to be reproductively isolated. © 2013 The Authors. Journal of Fish Biology © 2013 The Fisheries Society of the British Isles.

Disruption of male reproductive behavior in threespine stickleback asterosteus aculeatus exposed to 17β-estradiol

International Nuclear Information System (INIS)

Wibe, Asa Espmark; Rosenqvist, Gunilla; Jenssen, Bjoern Munro

2002-01-01

In past years we have witnessed decreased reproductive capacity in many wildlife species due to exposure to chemicals with endocrine-disrupting properties. In this laboratory experiment male three spine sticklebacks asterosteus aculeatus exposed to 17β-estradiol (2.0 μg/g) dispersed in peanut oil, on days 1, 7, 14, and 21, showed impaired paternal care compared to control fish that were exposed to peanut oil only. There were no differences between the two groups in number of males that built nests or in courtship displays. However, exposed males started nest building significantly later than control males. This study suggests that some but not all essential traits of male reproductive behavior may be altered as a result of exposure to 17β-estradiol. To reveal harmful effects of chemicals with suggested reproductive-disrupting properties it is thus important to take a wide variety of variables related to reproductive behavior into consideration

Introduction and spread of the threespine stickleback (Gasterosteus aculeatus) in Lakes Huron and Michigan

Science.gov (United States)

Stedman, Ralph M.; Bowen, Charles A.

1985-01-01

The threespine stickleback (Gasterosteus aculeatus) was not known to occur in the Great Lakes above Niagara Falls until 1980, when it was collected in South Bay, Manitoulin Island, in the Lake Huron basin. By 1984 this species had been found in tributaries of Lakes Huron and Michigan, and in the open waters of both lakes. All specimens identified were the completely plated morph that is most prevalent in fresh water along the east coast of North America. The status of this species in Lakes Huron and Michigan appears to be “Possibly Established.” If threespine stickleback increase in abundance they may eventually provide additional forage for large salmonids.

Induction of diploid gynogenesis in an evolutionary model organism, the three-spined stickleback (Gasterosteus aculeatus

Directory of Open Access Journals (Sweden)

Scharsack Jörn P

2011-09-01

Full Text Available Abstract Background Rapid advances in genomics have provided nearly complete genome sequences for many different species. However, no matter how the sequencing technology has improved, natural genetic polymorphism complicates the production of high quality reference genomes. To address this problem, researchers have tried using artificial modes of genome manipulation such as gynogenesis for fast production of inbred lines. Results Here, we present the first successful induction of diploid gynogenesis in an evolutionary model system, the three-spined sticklebacks (Gasterosteus aculeatus, using a combination of UV-irradiation of the sperm and heat shock (HS of the resulting embryo to inhibit the second meiotic division. Optimal UV irradiation of the sperm was established by exposing stickleback sperm to a UV- light source at various times. Heat shock parameters like temperature, duration, and time of initiation were tested by subjecting eggs fertilized with UV inactivated sperm 5, 10, 15, 20, 25, or 30 minutes post fertilization (mpf to 30°C, 34°C, or 38°C for 2, 4, 6 or 8 minutes. Gynogen yield was highest when stickleback eggs were activated with 2 minutes UV-irradiated sperm and received HS 5 mpf at 34°C for 4 minutes. Conclusions Diploid gynogenesis has been successfully performed in three-spined stickleback. This has been confirmed by microsatellite DNA analysis which revealed exclusively maternal inheritance in all gynogenetic fry tested. Ploidy verification by flow cytometry showed that gynogenetic embryos/larvae exhibiting abnormalities were haploids and those that developed normally were diploids, i.e., double haploids that can be raised until adult size.

Induction of diploid gynogenesis in an evolutionary model organism, the three-spined stickleback (Gasterosteus aculeatus)

Science.gov (United States)

2011-01-01

Background Rapid advances in genomics have provided nearly complete genome sequences for many different species. However, no matter how the sequencing technology has improved, natural genetic polymorphism complicates the production of high quality reference genomes. To address this problem, researchers have tried using artificial modes of genome manipulation such as gynogenesis for fast production of inbred lines. Results Here, we present the first successful induction of diploid gynogenesis in an evolutionary model system, the three-spined sticklebacks (Gasterosteus aculeatus), using a combination of UV-irradiation of the sperm and heat shock (HS) of the resulting embryo to inhibit the second meiotic division. Optimal UV irradiation of the sperm was established by exposing stickleback sperm to a UV- light source at various times. Heat shock parameters like temperature, duration, and time of initiation were tested by subjecting eggs fertilized with UV inactivated sperm 5, 10, 15, 20, 25, or 30 minutes post fertilization (mpf) to 30°C, 34°C, or 38°C for 2, 4, 6 or 8 minutes. Gynogen yield was highest when stickleback eggs were activated with 2 minutes UV-irradiated sperm and received HS 5 mpf at 34°C for 4 minutes. Conclusions Diploid gynogenesis has been successfully performed in three-spined stickleback. This has been confirmed by microsatellite DNA analysis which revealed exclusively maternal inheritance in all gynogenetic fry tested. Ploidy verification by flow cytometry showed that gynogenetic embryos/larvae exhibiting abnormalities were haploids and those that developed normally were diploids, i.e., double haploids that can be raised until adult size. PMID:21910888

Using Hidden Markov Models to characterise intermittent social behaviour in fish shoals

Science.gov (United States)

Bode, Nikolai W. F.; Seitz, Michael J.

2018-02-01

The movement of animals in groups is widespread in nature. Understanding this phenomenon presents an important problem in ecology with many applications that range from conservation to robotics. Underlying all group movements are interactions between individual animals and it is therefore crucial to understand the mechanisms of this social behaviour. To date, despite promising methodological developments, there are few applications to data of practical statistical techniques that inferentially investigate the extent and nature of social interactions in group movement. We address this gap by demonstrating the usefulness of a Hidden Markov Model approach to characterise individual-level social movement in published trajectory data on three-spined stickleback shoals ( Gasterosteus aculeatus) and novel data on guppy shoals ( Poecilia reticulata). With these models, we formally test for speed-mediated social interactions and verify that they are present. We further characterise this inferred social behaviour and find that despite the substantial shoal-level differences in movement dynamics between species, it is qualitatively similar in guppies and sticklebacks. It is intermittent, occurring in varying numbers of individuals at different time points. The speeds of interacting fish follow a bimodal distribution, indicating that they are either stationary or move at a preferred mean speed, and social fish with more social neighbours move at higher speeds, on average. Our findings and methodology present steps towards characterising social behaviour in animal groups.

Prey partitioning and use of insects by juvenile sockeye salmon and a potential competitor, threespine stickleback, in Afognak Lake, Alaska

Science.gov (United States)

Richardson, Natura; Beaudreau, Anne H.; Wipfli, Mark S.; Finkle, Heather

2017-01-01

Freshwater growth of juvenile sockeye salmon (Oncorhynchus nerka) depends upon the quality and quantity of prey and interactions with potential competitors in the foraging environment. To a large extent, knowledge about the ecology of lake-rearing juvenile sockeye salmon has emerged from studies of commercially important runs returning to deep nursery lakes, yet information from shallow nursery lakes (mean depth ≤ 10 m) is limited. We examined seasonal and ontogenetic variation in diets of juvenile sockeye salmon (N = 219, 30–85 mm) and an abundant potential competitor, threespine stickleback (Gasterosteus aculeatus; N = 198, 42–67 mm), to understand their foraging ecology and potential trophic interactions in a shallow Alaska lake. This study revealed that adult insects made up 74% of all sockeye salmon diets by weight and were present in 98% of all stomachs in Afognak Lake during the summer of 2013. Diets varied temporally for all fishes, but small sockeye salmon (insects in late summer. We found significant differences in diet composition between sockeye salmon and threespine stickleback and the origin of their prey indicated that they also separated their use of habitat on a fine scale; however, the two species showed overlap in size selectivity of zooplankton prey. Considering that aquatic insects can be a primary resource for juvenile sockeye salmon in Afognak Lake, we encourage the development of nursery lake carrying capacity models that include aquatic insects as a prey source for sockeye salmon.

Stickleback Population

Directory of Open Access Journals (Sweden)

Ulrika Candolin

2012-01-01

Full Text Available Human-induced eutrophication has increased offspring production in a population of threespine stickleback Gasterosteus aculeatus in the Baltic Sea. Here, we experimentally investigated the effects of an increased density of juveniles on behaviours that influence survival and dispersal, and, hence, population growth—habitat choice, risk taking, and foraging rate. Juveniles were allowed to choose between two habitats that differed in structural complexity, in the absence and presence of predators and conspecific juveniles. In the absence of predators or conspecifics, juveniles preferred the more complex habitat. The preference was further enhanced in the presence of a natural predator, a perch Perca fluviatilis (behind a transparent Plexiglas wall. However, an increased density of conspecifics relaxed the predator-enhanced preference for the complex habitat and increased the use of the open, more predator-exposed habitat. Foraging rate was reduced under increased perceived predation risk. These results suggest that density-dependent behaviours can cause individuals to choose suboptimal habitats where predation risk is high and foraging rate low. This could contribute to the regulation of population growth in eutrophicated areas where offspring production is high.

Unique mitochondrial DNA lineages in Irish stickleback populations: cryptic refugium or rapid recolonization?

Science.gov (United States)

Ravinet, Mark; Harrod, Chris; Eizaguirre, Christophe; Prodöhl, Paulo A

2014-06-01

Repeated recolonization of freshwater environments following Pleistocene glaciations has played a major role in the evolution and adaptation of anadromous taxa. Located at the western fringe of Europe, Ireland and Britain were likely recolonized rapidly by anadromous fishes from the North Atlantic following the last glacial maximum (LGM). While the presence of unique mitochondrial haplotypes in Ireland suggests that a cryptic northern refugium may have played a role in recolonization, no explicit test of this hypothesis has been conducted. The three-spined stickleback is native and ubiquitous to aquatic ecosystems throughout Ireland, making it an excellent model species with which to examine the biogeographical history of anadromous fishes in the region. We used mitochondrial and microsatellite markers to examine the presence of divergent evolutionary lineages and to assess broad-scale patterns of geographical clustering among postglacially isolated populations. Our results confirm that Ireland is a region of secondary contact for divergent mitochondrial lineages and that endemic haplotypes occur in populations in Central and Southern Ireland. To test whether a putative Irish lineage arose from a cryptic Irish refugium, we used approximate Bayesian computation (ABC). However, we found no support for this hypothesis. Instead, the Irish lineage likely diverged from the European lineage as a result of postglacial isolation of freshwater populations by rising sea levels. These findings emphasize the need to rigorously test biogeographical hypothesis and contribute further evidence that postglacial processes may have shaped genetic diversity in temperate fauna.

Different phylogenomic approaches to resolve the evolutionary relationships among model fish species.

Science.gov (United States)

Negrisolo, Enrico; Kuhl, Heiner; Forcato, Claudio; Vitulo, Nicola; Reinhardt, Richard; Patarnello, Tomaso; Bargelloni, Luca

2010-12-01

Comparative genomics holds the promise to magnify the information obtained from individual genome sequencing projects, revealing common features conserved across genomes and identifying lineage-specific characteristics. To implement such a comparative approach, a robust phylogenetic framework is required to accurately reconstruct evolution at the genome level. Among vertebrate taxa, teleosts represent the second best characterized group, with high-quality draft genome sequences for five model species (Danio rerio, Gasterosteus aculeatus, Oryzias latipes, Takifugu rubripes, and Tetraodon nigroviridis), and several others are in the finishing lane. However, the relationships among the acanthomorph teleost model fishes remain an unresolved taxonomic issue. Here, a genomic region spanning over 1.2 million base pairs was sequenced in the teleost fish Dicentrarchus labrax. Together with genomic data available for the above fish models, the new sequence was used to identify unique orthologous genomic regions shared across all target taxa. Different strategies were applied to produce robust multiple gene and genomic alignments spanning from 11,802 to 186,474 amino acid/nucleotide positions. Ten data sets were analyzed according to Bayesian inference, maximum likelihood, maximum parsimony, and neighbor joining methods. Extensive analyses were performed to explore the influence of several factors (e.g., alignment methodology, substitution model, data set partitions, and long-branch attraction) on the tree topology. Although a general consensus was observed for a closer relationship between G. aculeatus (Gasterosteidae) and Di. labrax (Moronidae) with the atherinomorph O. latipes (Beloniformes) sister taxon of this clade, with the tetraodontiform group Ta. rubripes and Te. nigroviridis (Tetraodontiformes) representing a more distantly related taxon among acanthomorph model fish species, conflicting results were obtained between data sets and methods, especially with respect

Male red ornamentation is associated with female red sensitivity in sticklebacks.

Directory of Open Access Journals (Sweden)

Ingolf P Rick

Full Text Available Sexual selection theory proposes correlated evolutionary changes in mating preferences and secondary sexual characters based on a positive genetic correlation between preference and the preferred trait. Empirical work has provided support for a genetic covariation between female preference and male attractiveness in several taxa. Here, we study parent and offspring visual traits in threespine sticklebacks, Gasterosteus aculeatus. While focusing on the proximate basis of mating preferences, we compare the red breeding coloration of males, which strongly contributes to female choice, with their daughters' red sensitivity measured by optomotor response thresholds. We show that the red color expression of fathers correlates well with their daughters' red sensitivity. Given that a within-population genetic correlation between signal and preference was experimentally confirmed for the red coloration in sticklebacks, our results indicate a proximate mechanism in terms of perceptual sensitivity being involved in the co-evolution of female preferences and male mating signals.

Rapid molecular sexing of three-spined sticklebacks, Gasterosteus aculeatus L., based on large Y-chromosomal insertions.

Science.gov (United States)

Bakker, Theo C M; Giger, Thomas; Frommen, Joachim G; Largiadèr, Carlo R

2017-08-01

There is a need for rapid and reliable molecular sexing of three-spined sticklebacks, Gasterosteus aculeatus, the supermodel species for evolutionary biology. A DNA region at the 5' end of the sex-linked microsatellite Gac4202 was sequenced for the X chromosome of six females and the Y chromosome of five males from three populations. The Y chromosome contained two large insertions, which did not recombine with the phenotype of sex in a cross of 322 individuals. Genetic variation (SNPs and indels) within the insertions was smaller than on flanking DNA sequences. Three molecular PCR-based sex tests were developed, in which the first, the second or both insertions were covered. In five European populations (from DE, CH, NL, GB) of three-spined sticklebacks, tests with both insertions combined showed two clearly separated bands on agarose minigels in males and one band in females. The tests with the separate insertions gave similar results. Thus, the new molecular sexing method gave rapid and reliable results for sexing three-spined sticklebacks and is an improvement and/or alternative to existing methods.

Developmental exposure to the SSRI citalopram causes long-lasting behavioural effects in the three-spined stickleback (Gasterosteus aculeatus).

Science.gov (United States)

Kellner, M; Porseryd, T; Porsch-Hällström, I; Borg, B; Roufidou, C; Olsén, K H

2018-01-01

Selective Serotonin re-uptake inhibitors (SSRIs) are a class of psychotropic drugs used to treat depression in both adolescents and pregnant or breast-feeding mothers as well as in the general population. Recent research on rodents points to long-lasting behavioural effects of pre- and perinatal exposure to SSRIs which last into adulthood. In fish however, studies on effects of developmental exposure to SSRIs appears to be non-existent. In order to study effects of developmental SSRI exposure in fish, three-spine sticklebacks were exposed to 1.5 µg/l of the SSRI citalopram in the ambient water for 30 days, starting two days post-fertilisation. After approximately 100 days of remediation in clean water the fish were put through an extensive battery of behavioural tests. Feeding behaviour was tested as the number of bites against a piece of food and found to be increased in the exposed fish. Aggression levels were measured as the number of bites against a mirror image during 10 min and was also found to be significantly increased in the exposed fish. Novel tank behaviour and locomotor activity was tested in an aquarium that had a horizontal line drawn half-way between the bottom and the surface. Neither the latency to the first transition to the upper half, nor the number of transitions or the total time spent in the upper half was affected by treatment. Locomotor activity was significantly reduced in the exposed fish. The light/dark preference was tested in an aquarium where the bottom and walls were black on one side and white on the other. The number of transitions to the white side was significantly reduced in the exposed fish but there was no effect on the latency to the first transition or the total time spent in the white half. The results in the current study indicate that developmental SSRI exposure causes long-lasting behavioural effects in fish and contribute to the existing knowledge about SSRIs as environmental pollutants.

A universal and reliable assay for molecular sex identification of three-spined sticklebacks (Gasterosteus aculeatus).

Science.gov (United States)

Toli, E-A; Calboli, F C F; Shikano, T; Merilä, J

2016-11-01

In heterogametic species, biological differences between the two sexes are ubiquitous, and hence, errors in sex identification can be a significant source of noise and bias in studies where sex-related sources of variation are of interest or need to be controlled for. We developed and validated a universal multimarker assay for reliable sex identification of three-spined sticklebacks (Gasterosteus aculeatus). The assay makes use of genotype scores from three sex-linked loci and utilizes Bayesian probabilistic inference to identify sex of the genotyped individuals. The results, validated with 286 phenotypically sexed individuals from six populations of sticklebacks representing all major genetic lineages (cf. Pacific, Atlantic and Japan Sea), indicate that in contrast to commonly used single-marker-based sex identification assays, the developed multimarker assay should be 100% accurate. As the markers in the assay can be scored from agarose gels, it provides a quick and cost-efficient tool for universal sex identification of three-spined sticklebacks. The general principle of combining information from multiple markers to improve the reliability of sex identification is transferable and can be utilized to develop and validate similar assays for other species. © 2016 John Wiley & Sons Ltd.

Identification of novel microRNA genes in freshwater and marine ecotypes of the three-spined stickleback (Gasterosteus aculeatus).

Science.gov (United States)

Rastorguev, S M; Nedoluzhko, A V; Sharko, F S; Boulygina, E S; Sokolov, A S; Gruzdeva, N M; Skryabin, K G; Prokhortchouk, E B

2016-11-01

The three-spined stickleback (Gasterosteus aculeatus L.) is an important model organism for studying the molecular mechanisms of speciation and adaptation to salinity. Despite increased interest to microRNA discovery and recent publication on microRNA prediction in the three-spined stickleback using bioinformatics approaches, there is still a lack of experimental support for these data. In this paper, high-throughput sequencing technology was applied to identify microRNA genes in gills of the three-spined stickleback. In total, 595 miRNA genes were discovered; half of them were predicted in previous computational studies and were confirmed here as microRNAs expressed in gill tissue. Moreover, 298 novel microRNA genes were identified. The presence of miRNA genes in selected 'divergence islands' was analysed and 10 miRNA genes were identified as not randomly located in 'divergence islands'. Regulatory regions of miRNA genes were found enriched with selective SNPs that may play a role in freshwater adaptation. © 2016 John Wiley & Sons Ltd.

Implications of a fossil stickleback assemblage for Darwinian gradualism.

Science.gov (United States)

Bell, M A

2009-11-01

Darwin postulated that a complete fossil record would contain numerous gradual transitions between ancestral and descendant species, but 150 years after publication of The Origin of Species, few such transitions have materialized. The fossil stickleback Gasterosteus doryssus and the deposit in which it occurs provide excellent conditions to detect such transitions. Abundant, well-preserved fossils occur in a stratigraphic setting with fine temporal resolution. The paleoecology of G. doryssus resembles the ecology of modern lakes that harbour the phenotypically similar three-spined stickleback Gasterosteus aculeatus. Gasterosteus aculeatus are primitively highly armoured, but G. doryssus comprised two contemporaneous biological species with relatively weak armour, including a near-shore, benthic feeder (benthic) and an offshore planktivore (limnetic). The benthic species expanded its range into the limnetic zone of the lake, where it apparently switched to planktivory and evolved reduced armour within c. 5000 years in response to directional selection. Although gradual evolution of mean phenotypes occurred, a single major gene caused much of evolutionary change of the pelvic skeleton. Thus, Darwin's expectation that transitions between species in the fossil record would be gradual was met at a fine time scale, but for pelvic structure, a well-studied trait, his expectation that gradual change would depend entirely on numerous, small, heritable differences among individuals was incorrect.

Phenotypic plasticity drives a depth gradient in male conspicuousness in threespine stickleback, Gasterosteus aculeatus.

Science.gov (United States)

Brock, Chad D; Cummings, Molly E; Bolnick, Daniel I

2017-08-01

Signal evolution is thought to depend on both a signal's detectability or conspicuousness (signal design) as well as any extractable information it may convey to a potential receiver (signal content). While theoretical and empirical work in sexual selection has largely focused on signal content, there has been a steady accrual of evidence that signal design is also important for trait evolution. Despite this, relatively little attention has been paid to spatial variation in the conspicuousness of a given signal, especially over small spatial scales (relative to an organism's dispersal distance). Here, we show that visual signals of male threespine stickleback vary in conspicuousness, depending on a male's nest depth within a given lake. Deeper nesting males were typically more chromatically conspicuous than shallow nesting males. This trend is partly because all male stickleback are more conspicuous in deep optical environments. However, deep males are even more conspicuous than environmentally driven null expectations, while shallow males tend to be disproportionally cryptic. Experimental manipulation of male nesting depth induced plastic changes in nuptial color that replicated the natural gradients in conspicuousness. We discuss a number of potential mechanisms that could produce depth gradients in conspicuousness in male stickleback, including concomitant depth gradients in diet, predation pressure, male/female density, female preference, and opportunity for sexual selection. © 2017 The Author(s). Evolution © 2017 The Society for the Study of Evolution.

PARTIAL REPRODUCTIVE ISOLATION OF A RECENTLY DERIVED RESIDENT-FRESHWATER POPULATION OF THREESPINE STICKLEBACK (GASTEROSTEUS ACULEATUS) FROM ITS PUTATIVE ANADROMOUS ANCESTOR

Science.gov (United States)

Furin, Christoff G.; Von Hippel, Frank A.; Bell, Michael A.

2012-01-01

We used no-choice mating trials to test for assortative mating between a newly derived resident-freshwater population (8 – 22 generations since founding) of threespine stickleback (Gasterosteus aculeatus) in Loberg Lake, Alaska and its putative anadromous ancestor as well as a morphologically convergent but distantly related resident-freshwater population. Partial reproductive isolation has evolved between the Loberg Lake population and its ancestor within a remarkably short time period. However, Loberg stickleback readily mate with morphologically similar, but distantly related resident-freshwater stickleback. Partial pre-mating isolation is asymmetrical; anadromous females and smaller, resident-freshwater males from Loberg Lake readily mate, but the anadromous males and smaller Loberg females do not. Our results indicate that pre-mating isolation can begin to evolve in allopatry within a few generations after isolation as a correlated effect of evolution of reduced body size. PMID:23025615

Genetics of body shape and armour variation in threespine sticklebacks.

Science.gov (United States)

Leinonen, T; Cano, J M; Merilä, J

2011-01-01

Patterns of genetic variation and covariation can influence the rate and direction of phenotypic evolution. We explored the possibility that the parallel morphological evolution seen in threespine stickleback (Gasterosteus aculeatus) populations colonizing freshwater environments is facilitated by patterns of genetic variation and covariation in the ancestral (marine) population. We estimated the genetic (G) and phenotypic (P) covariance matrices and directions of maximum additive genetic (g(max) ) and phenotypic (p(max) ) covariances of body shape and armour traits. Our results suggest a role for the ancestral G in explaining parallel morphological evolution in freshwater populations. We also found evidence of genetic constraints owing to the lack of variance in the ancestral G. Furthermore, strong genetic covariances and correlations among traits revealed that selective factors responsible for threespine stickleback body shape and armour divergence may be difficult to disentangle. The directions of g(max) and p(max) were correlated, but the correlations were not high enough to imply that phenotypic patterns of trait variation and covariation within populations are very informative of underlying genetic patterns. © 2010 The Authors. Journal of Evolutionary Biology © 2010 European Society For Evolutionary Biology.

Environmentally relevant concentrations of citalopram partially inhibit feeding in the three-spine stickleback (Gasterosteus aculeatus).

Science.gov (United States)

Kellner, M; Porseryd, T; Porsch-Hällström, I; Hansen, S H; Olsén, K H

2015-01-01

Selective Serotonin Re-uptake Inhibitors (SSRI) are mood-altering, psychotropic drugs commonly used in the treatment of depression and other psychological illnesses. Many of them are poorly degraded in sewage treatment plants and enter the environment unaltered. In laboratory studies, they have been demonstrated to affect a wide range of behaviours in aquatic organisms. In this study we investigated the effect of a three-week exposure to 0.15 and 1.5 μg/l of the SSRI citalopram dissolved in the ambient water on the feeding behaviour in three-spine stickleback (Gasterosteus aculeatus). Feeding, measured as the number of attacks performed on a piece of frozen bloodworms during a 10-min period, was reduced by 30-40% in fish exposed to both 0.15 and 1.5 μg/l citalopram. The effects of the environmentally relevant concentration 0.15 μg/l on feeding, an important fitness characteristic, suggests that the ecological significance of environmental SSRI exposure may be pronounced. Copyright © 2014 Elsevier B.V. All rights reserved.

Three-spined stickleback Gasterosteus aculeatus, as a possible paratenic host for salmonid nematodes in a subarctic lake.

Science.gov (United States)

Braicovich, Paola E; Kuhn, Jesper A; Amundsen, Per-Arne; Marcogliese, David J

2016-03-01

In Takvatn, a subarctic lake in northern Norway, 35 of 162 three-spined sticklebacks examined were infected with 106 specimens of third-stage larvae of Philonema oncorhynchi. The prevalence and mean intensity of P. oncorhynchi were 10 % and 2.0 in 2013 and 24 % and 3.0 in 2014, respectively. A single specimen of Cystidicola farionis was found in an additional sample. While the latter is considered an accidental infection, three-spined sticklebacks may function as paratenic hosts of P. oncorhynchi, potentially enhancing its transmission to salmonids due to their central role in the lacustrine food web of this subarctic lake.

In situ effects of metal contamination from former uranium mining sites on the health of the three-spined stickleback (Gasterosteus aculeatus, L.).

Science.gov (United States)

Le Guernic, Antoine; Sanchez, Wilfried; Bado-Nilles, Anne; Palluel, Olivier; Turies, Cyril; Chadili, Edith; Cavalié, Isabelle; Delahaut, Laurence; Adam-Guillermin, Christelle; Porcher, Jean-Marc; Geffard, Alain; Betoulle, Stéphane; Gagnaire, Béatrice

2016-08-01

Human activities have led to increased levels of various pollutants including metals in aquatic ecosystems. Increase of metallic concentrations in aquatic environments represents a potential risk to exposed organisms, including fish. The aim of this study was to characterize the environmental risk to fish health linked to a polymetallic contamination from former uranium mines in France. This contamination is characterized by metals naturally present in the areas (manganese and iron), uranium, and metals (aluminum and barium) added to precipitate uranium and its decay products. Effects from mine releases in two contaminated ponds (Pontabrier for Haute-Vienne Department and Saint-Pierre for Cantal Department) were compared to those assessed at four other ponds outside the influence of mine tailings (two reference ponds/department). In this way, 360 adult three-spined sticklebacks (Gasterosteus aculeatus) were caged for 28 days in these six ponds before biomarker analyses (immune system, antioxidant system, biometry, histology, DNA integrity, etc.). Ponds receiving uranium mine tailings presented higher concentrations of uranium, manganese and aluminum, especially for the Haute-Vienne Department. This uranium contamination could explain the higher bioaccumulation of this metal in fish caged in Pontabrier and Saint-Pierre Ponds. In the same way, many fish biomarkers (antioxidant and immune systems, acetylcholinesterase activity and biometric parameters) were impacted by this environmental exposure to mine tailings. This study shows the interest of caging and the use of a multi-biomarker approach in the study of a complex metallic contamination.

The genomic landscape at a late stage of stickleback speciation: High genomic divergence interspersed by small localized regions of introgression.

Directory of Open Access Journals (Sweden)

Mark Ravinet

2018-05-01

Full Text Available Speciation is a continuous process and analysis of species pairs at different stages of divergence provides insight into how it unfolds. Previous genomic studies on young species pairs have revealed peaks of divergence and heterogeneous genomic differentiation. Yet less known is how localised peaks of differentiation progress to genome-wide divergence during the later stages of speciation in the presence of persistent gene flow. Spanning the speciation continuum, stickleback species pairs are ideal for investigating how genomic divergence builds up during speciation. However, attention has largely focused on young postglacial species pairs, with little knowledge of the genomic signatures of divergence and introgression in older stickleback systems. The Japanese stickleback species pair, composed of the Pacific Ocean three-spined stickleback (Gasterosteus aculeatus and the Japan Sea stickleback (G. nipponicus, which co-occur in the Japanese islands, is at a late stage of speciation. Divergence likely started well before the end of the last glacial period and crosses between Japan Sea females and Pacific Ocean males result in hybrid male sterility. Here we use coalescent analyses and Approximate Bayesian Computation to show that the two species split approximately 0.68-1 million years ago but that they have continued to exchange genes at a low rate throughout divergence. Population genomic data revealed that, despite gene flow, a high level of genomic differentiation is maintained across the majority of the genome. However, we identified multiple, small regions of introgression, occurring mainly in areas of low recombination rate. Our results demonstrate that a high level of genome-wide divergence can establish in the face of persistent introgression and that gene flow can be localized to small genomic regions at the later stages of speciation with gene flow.

The genomic landscape at a late stage of stickleback speciation: High genomic divergence interspersed by small localized regions of introgression.

Science.gov (United States)

Ravinet, Mark; Yoshida, Kohta; Shigenobu, Shuji; Toyoda, Atsushi; Fujiyama, Asao; Kitano, Jun

2018-05-01

Speciation is a continuous process and analysis of species pairs at different stages of divergence provides insight into how it unfolds. Previous genomic studies on young species pairs have revealed peaks of divergence and heterogeneous genomic differentiation. Yet less known is how localised peaks of differentiation progress to genome-wide divergence during the later stages of speciation in the presence of persistent gene flow. Spanning the speciation continuum, stickleback species pairs are ideal for investigating how genomic divergence builds up during speciation. However, attention has largely focused on young postglacial species pairs, with little knowledge of the genomic signatures of divergence and introgression in older stickleback systems. The Japanese stickleback species pair, composed of the Pacific Ocean three-spined stickleback (Gasterosteus aculeatus) and the Japan Sea stickleback (G. nipponicus), which co-occur in the Japanese islands, is at a late stage of speciation. Divergence likely started well before the end of the last glacial period and crosses between Japan Sea females and Pacific Ocean males result in hybrid male sterility. Here we use coalescent analyses and Approximate Bayesian Computation to show that the two species split approximately 0.68-1 million years ago but that they have continued to exchange genes at a low rate throughout divergence. Population genomic data revealed that, despite gene flow, a high level of genomic differentiation is maintained across the majority of the genome. However, we identified multiple, small regions of introgression, occurring mainly in areas of low recombination rate. Our results demonstrate that a high level of genome-wide divergence can establish in the face of persistent introgression and that gene flow can be localized to small genomic regions at the later stages of speciation with gene flow.

Geographical variation in colour of female threespine stickleback (Gasterosteus aculeatus)

OpenAIRE

Connor M. French; Travis Ingram; Daniel I. Bolnick

2018-01-01

The ecological multifunctionality of colour often results in multiple selective pressures operating on a single trait. Most research on colour evolution focuses on males because they are the most conspicuous sex in most species. This bias can limit inferences about the ecological drivers of colour evolution. For example, little is known about population divergence in colour of female threespine stickleback (Gasterosteus aculeatus), which is among the most intensively-studied model vertebrates...

Status and trends of prey fish populations in Lake Michigan, 2013

Science.gov (United States)

Madenjian, Charles P.; Bunnell, David B.; Desorcie, Timothy J.; Kostich, Melissa Jean; Armenio, Patricia M.; Adams, Jean V.

2015-01-01

The U.S. Geological Survey Great Lakes Science Center has conducted lake-wide surveys of the fish community in Lake Michigan each fall since 1973 using standard 12-m bottom trawls towed along contour at depths of 9 to 110 m at each of seven index transects. The resulting data on relative abundance, size and age structure, and condition of individual fishes are used to estimate various population parameters that are in turn used by state and tribal agencies in managing Lake Michigan fish stocks. All seven established index transects of the survey were completed in 2013. The survey provides relative abundance and biomass estimates between the 5-m and 114-m depth contours of the lake (herein, lake-wide) for prey fish populations, as well as burbot, yellow perch, and the introduced dreissenid mussels. Lake-wide biomass of alewives in 2013 was estimated at 29 kilotonnes (kt, 1 kt = 1000 metric tonnes), which was more than three times the 2012 estimate. However, the unusually high standard error associated with the 2013 estimate indicated no significant increase in lake-wide biomass between 2012 and 2013. Moreover, the age distribution of alewives remained truncated with no alewife exceeding an age of 5. The population of age-1 and older alewives was dominated (i.e., 88%) by the 2010 and 2012 year-classes. Record low biomass was observed for deepwater sculpin (1.3 kt) and ninespine stickleback (0.004 kt) in 2013, while bloater (1.6 kt) and rainbow smelt (0.2 kt) biomasses remained at low levels. Slimy sculpin lake-wide biomass was 0.32 kt in 2013, marking the fourth consecutive year of a decline. The 2013 biomass of round goby was estimated at 10.9 kt, which represented the peak estimate to date. Burbot lake-wide biomass (0.4 kt in 2013) has remained below 3 kt since 2001. Numeric density of age-0 yellow perch (i.e., fish per ha, which is indicative of a relatively poor year-class. Lake-wide biomass estimate of dreissenid mussels in 2013 was 23.2 kt. Overall, the total

Brain arginine vasotocin and isotocin in breeding female three-spined sticklebacks (Gasterosteus aculeatus): the presence of male and egg deposition.

Science.gov (United States)

Kulczykowska, Ewa; Kleszczyńska, Agnieszka

2014-08-01

Arginine vasotocin (AVT) and isotocin (IT) are fish hypothalamic nonapeptides involved in numerous social and reproductive behaviors. Vasotocinergic and isotocinergic fibers project to different brain areas where peptides act as neurotransmitters and/or neuromodulators. In this study, we measured whole brain levels of bioactive AVT and IT in breeding females of three-spined stickleback (Gasterosteus aculeatus) when they were kept with: (i) courting nest-owners, (ii) courting males that did not build the nest, (iii) non-courting males, and (iv) alone. Only some of the females kept with courting nest-owners deposited eggs. The highest and similar brain AVT levels were in those of females that did not deposit eggs, regardless of whether they were kept with non-courting or courting male, having the nest or not. The highest IT levels were in females that did not deposit eggs but only in those kept with courting male. We suggest that production of AVT in females' brain is stimulated by the presence of male in close proximity, irrespective of whether or not it displays courting behavior, but that of IT is stimulated by male courtship proxies. Moreover, presence of courting or non-courting male that stimulate IT or/and AVT producing neurones may be decisive for final oocyte maturation or egg deposition, because brain levels of both nonapeptides decrease after egg deposition. Similar AVT levels in brains of aggressive and non-aggressive individuals and lack of correlation between brain IT levels and aggressive behavior of females suggest that the nonapeptides are not related to females aggressiveness in three-spined sticklebacks. Copyright © 2014. Published by Elsevier Inc.

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

Science.gov (United States)

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

2007-01-01

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

Computational identification of miRNAs, their targets and functions in three-spined stickleback (Gasterosteus aculeatus).

Science.gov (United States)

Chaturvedi, Anurag; Raeymaekers, Joost A M; Volckaert, Filip A M

2014-07-01

An intriguing question in biology is how the evolution of gene regulation is shaped by natural selection in natural populations. Among the many known regulatory mechanisms, regulation of gene expression by microRNAs (miRNAs) is of critical importance. However, our understanding of their evolution in natural populations is limited. Studying the role of miRNAs in three-spined stickleback, an important natural model for speciation research, may provide new insights into adaptive polymorphisms. However, lack of annotation of miRNA genes in its genome is a bottleneck. To fill this research gap, we used the genome of three-spined stickleback to predict miRNAs and their targets. We predicted 1486 mature miRNAs using the homology-based miRNA prediction approach. We then performed functional annotation and enrichment analysis of these targets, which identified over-represented motifs. Further, a database resource (GAmiRdb) has been developed for dynamically searching miRNAs and their targets exclusively in three-spined stickleback. Finally, the database was used in two case studies focusing on freshwater adaptation in natural populations. In the first study, we found 44 genomic regions overlapping with predicted miRNA targets. In the second study, we identified two SNPs altering the MRE seed site of sperm-specific glyceraldehyde-3-phosphate gene. These findings highlight the importance of the GAmiRdb knowledge base in understanding adaptive evolution. © 2014 John Wiley & Sons Ltd.

Peroxisomes in intestinal and gallbladder epithelial cells of the stickleback, Gasterosteus aculeatus L. (Teleostei)

NARCIS (Netherlands)

Ruiter, A.J.H. de; Veenhuis, M.; Wendelaar Bonga, S.E.

1988-01-01

The occurrence of microbodies in the epithelial cells of the intestine and gallbladder of the stickleback, Gasterosteus aculeatus L., is described. In the intestine the organelles are predominantly located in the apical and perinuclear zone of the cells and may contain small crystalline cores. In

Small Variations in Early-Life Environment Can Affect Coping Behaviour in Response to Foraging Challenge in the Three-Spined Stickleback.

Directory of Open Access Journals (Sweden)

M Rohaa Langenhof

Full Text Available An increasing concern in the face of human expansion throughout natural habitats is whether animal populations can respond adaptively when confronted with challenges like environmental change and novelty. Behavioural flexibility is an important factor in estimating the adaptive potential of both individuals and populations, and predicting the degree to which they can cope with change.This study on the three-spined stickleback (Gasterosteus aculeatus is an empiric illustration of the degree of behavioural variation that can emerge between semi-natural systems within only a single generation. Wild-caught adult sticklebacks (P, N = 400 were randomly distributed in equal densities over 20 standardized semi-natural environments (ponds, and one year later offspring (F1, N = 652 were presented with repeated behavioural assays. Individuals were challenged to reach a food source through a novel transparent obstacle, during which exploration, activity, foraging, sociability and wall-biting behaviours were recorded through video observation. We found that coping responses of individuals from the first generation to this unfamiliar foraging challenge were related to even relatively small, naturally diversified variation in developmental environment. All measured behaviours were correlated with each other. Especially exploration, sociability and wall-biting were found to differ significantly between ponds. These differences could not be explained by stickleback density or the turbidity of the water.Our findings show that a differences in early-life environment appear to affect stickleback feeding behaviour later in life; b this is the case even when the environmental differences are only small, within natural parameters and diversified gradually; and c effects are present despite semi-natural conditions that fluctuate during the year. Therefore, in behaviourally plastic animals like the stickleback, the adaptive response to human-induced habitat disturbance

Small Variations in Early-Life Environment Can Affect Coping Behaviour in Response to Foraging Challenge in the Three-Spined Stickleback.

Science.gov (United States)

Langenhof, M Rohaa; Apperloo, Rienk; Komdeur, Jan

2016-01-01

An increasing concern in the face of human expansion throughout natural habitats is whether animal populations can respond adaptively when confronted with challenges like environmental change and novelty. Behavioural flexibility is an important factor in estimating the adaptive potential of both individuals and populations, and predicting the degree to which they can cope with change. This study on the three-spined stickleback (Gasterosteus aculeatus) is an empiric illustration of the degree of behavioural variation that can emerge between semi-natural systems within only a single generation. Wild-caught adult sticklebacks (P, N = 400) were randomly distributed in equal densities over 20 standardized semi-natural environments (ponds), and one year later offspring (F1, N = 652) were presented with repeated behavioural assays. Individuals were challenged to reach a food source through a novel transparent obstacle, during which exploration, activity, foraging, sociability and wall-biting behaviours were recorded through video observation. We found that coping responses of individuals from the first generation to this unfamiliar foraging challenge were related to even relatively small, naturally diversified variation in developmental environment. All measured behaviours were correlated with each other. Especially exploration, sociability and wall-biting were found to differ significantly between ponds. These differences could not be explained by stickleback density or the turbidity of the water. Our findings show that a) differences in early-life environment appear to affect stickleback feeding behaviour later in life; b) this is the case even when the environmental differences are only small, within natural parameters and diversified gradually; and c) effects are present despite semi-natural conditions that fluctuate during the year. Therefore, in behaviourally plastic animals like the stickleback, the adaptive response to human-induced habitat disturbance may occur

Mutual mate choice in sticklebacks : attractive males choose big females, which lay big eggs

NARCIS (Netherlands)

Kraak, SBM; Bakker, TCM

1998-01-01

Brighter red three-spined stickleback, Gasterostetus aculeatus, males have been shown to be preferred by females in the laboratory but in the field, these males did not receive more eggs. Instead, they had heavier eggs in their brood. We investigated the hypothesis that sexual selection for red

Population genetic dynamics of three-spined sticklebacks (Gasterosteus aculeatus) in anthropogenic altered habitats.

Science.gov (United States)

Scharsack, Joern P; Schweyen, Hannah; Schmidt, Alexander M; Dittmar, Janine; Reusch, Thorsten Bh; Kurtz, Joachim

2012-06-01

In industrialized and/or agriculturally used landscapes, inhabiting species are exposed to a variety of anthropogenic changes in their environments. Genetic diversity may be reduced if populations encounter founder events, bottlenecks, or isolation. Conversely, genetic diversity may increase if populations adapt to changes in selective regimes in newly created habitats. With the present study, genetic variability of 918 sticklebacks from 43 samplings (21.3 ± 3.8 per sample) at 36 locations from cultivated landscapes in Northwest Germany was analyzed at nine neutral microsatellite loci. To test if differentiation is influenced by habitat alterations, sticklebacks were collected from ancient running waters and adjacent artificial stagnant waters, from brooks with salt water inflow of anthropogenic and natural origin and adjacent freshwater sites. Overall population structure was dominated by isolation by distance (IBD), which was significant across all populations, and analysis of molecular variance (AMOVA) revealed that 10.6% of the variation was explained by river catchment area. Populations in anthropogenic modified habitats deviated from the general IBD structure and in the AMOVA, grouping by habitat type running/stagnant water explained 4.9% of variation and 1.4% of the variation was explained by salt-/freshwater habitat. Sticklebacks in salt-polluted water systems seem to exhibit elevated migratory activity between fresh- and saltwater habitats, reducing IBD. In other situations, populations showed distinct signs of genetic isolation, which in some locations was attributed to mechanical migration barriers, but in others to potential anthropogenic induced bottleneck or founder effects. The present study shows that anthropogenic habitat alterations may have diverse effects on the population genetic structure of inhabiting species. Depending on the type of habitat change, increased genetic differentiation, diversification, or isolation are possible consequences.

Global analysis of genes involved in freshwater adaptation in threespine sticklebacks (Gasterosteus aculeatus).

Science.gov (United States)

DeFaveri, Jacquelin; Shikano, Takahito; Shimada, Yukinori; Goto, Akira; Merilä, Juha

2011-06-01

Examples of parallel evolution of phenotypic traits have been repeatedly demonstrated in threespine sticklebacks (Gasterosteus aculeatus) across their global distribution. Using these as a model, we performed a targeted genome scan--focusing on physiologically important genes potentially related to freshwater adaptation--to identify genetic signatures of parallel physiological evolution on a global scale. To this end, 50 microsatellite loci, including 26 loci within or close to (directional selection were detected in 24 loci, including 17 physiologically important genes, in at least one location. Although no loci showed consistent signatures of selection in all divergent population pairs, several outliers were common in multiple locations. In particular, seven physiologically important genes, as well as reference ectodysplasin gene (EDA), showed signatures of selection in three or more locations. Hence, although these results give some evidence for consistent parallel molecular evolution in response to freshwater colonization, they suggest that different evolutionary pathways may underlie physiological adaptation to freshwater habitats within the global distribution of the threespine stickleback. © 2011 The Author(s). Evolution© 2011 The Society for the Study of Evolution.

Multi-metal contamination with uranium trend impact on aquatic environment and consequences for fish immune system and adaptive responses

Energy Technology Data Exchange (ETDEWEB)

Le Guernic, A.; Gagnaire, B. [IRSN/PRP-ENV/SERIS/LECO (France); Sanchez, W. [Institut national de l' environnement industriel et des risques - INERIS (France); Betoulle, S. [Champagne Ardenne University (France)

2014-07-01

Human activities have conducted to an increase of concentrations of various metals in aquatic ecosystems, including uranium. Its extraction and use have been rapidly magnified because of its role in the nuclear fuel cycle. These activities have led to high concentrations of uranium in the aquatic environment and thus a potential risk to exposed organisms, including fish. Consequences can be observed through metabolic and physiological responses, called biomarkers. Some biomarkers are interesting in order to evaluate the effects of metal contamination, among other immunotoxicity markers, antioxidant defenses and genotoxicity. The aims of this study are: i) to investigate the effects of a multi-metal contamination on a fish, the three-spined stickleback, Gasterosteus aculeatus, and ii) to observe the adaptive capacity of fish due to a combination of stress (chemical stress and biological stress). To meet the first objective, six water bodies (ponds and lakes) located in two departments (Cantal and Haute-Vienne, France) were chosen according to their proximity to old uranium mines and to their levels of metal contamination related to chemical processes appeared during extraction. 240 three-spined sticklebacks were caged for 28 days in the six selected sites. A battery of biomarkers was measured in fish sampled after 14 and 28 of caging. The results for the Haute-Vienne department showed that caged fish in the pond with the highest uranium concentration (20 μg.L{sup -1}) presented the most DNA damage after 14 days of caging. Leukocyte phagocytosis (marker of immunotoxicity) of caged fish in this pond was lower at 14 days and greater at 28 days compared to other ponds without uranium. The multi-metal contamination negatively affected other parameters such as the condition index, oxidative activity, viability of lysosomal membrane and leukocytes distribution. In order to study the response of fish to a combined stress (chemical + biological) (objective ii), a second

Displaced phylogeographic signals from Gyrodactylus arcuatus, a parasite of the three-spined stickleback Gasterosteus aculeatus, suggest freshwater glacial refugia in Europe.

Science.gov (United States)

Lumme, Jaakko; Mäkinen, Hannu; Ermolenko, Alexey V; Gregg, Jacob L; Ziętara, Marek S

2016-08-01

We examined the global mitochondrial phylogeography of Gyrodactylus arcuatus, a flatworm ectoparasite of three-spined stickleback Gasterosteus aculeatus. In accordance with the suggested high divergence rate of 13%/million years, the genetic variation of the parasite was high: haplotype diversity h=0.985 and nucleotide diversity π=0.0161. The differentiation among the parasite populations was substantial (Φst=0.759), with two main allopatric clades (here termed Euro and North) accounting for 54% of the total genetic variation. The diversity center of the Euro clade was in the Baltic Sea, while the North clade was spread across the Barents and White Seas. A single haplotype within the North clade was found in the western and eastern Pacific Ocean. Divergence of main clades was estimated to be circa 200 thousand years ago. Each main clade was further divided into six distinct subclades, estimated to have diverged in isolation since 135 thousand years ago. This second division corresponds approximately to the Eemian interglacial predating the last glacial maximum. A demographic expansion of the subclades is associated with colonisation of northern Europe since the last glacial maximum, circa 15-40 thousand years ago. The parasite phylogeny is most likely explained by sequential isolated bottlenecks and expansions in numerous allopatric refugia. The postglacial intermingling and high variation in the marine parasite populations, separately in the Baltic and Barents Seas, suggest low competition of divergent parasite matrilines, coupled with a large population size and high rate of dispersal of hosts. The genetic contribution of the assumed refugial fish populations maintaining the parasite during the last glacial maximum was not detected among the marine sticklebacks, which perhaps were infected after range expansion. Copyright © 2016 Australian Society for Parasitology. All rights reserved.

Displaced phylogeographic signals from Gyrodactylus arcuatus, a parasite of the three-spined stickleback Gasterosteus aculeatus, suggest freshwater glacial refugia in Europe

Science.gov (United States)

Lumme, Jaakko; Mäkinen, Hannu; Ermolenko, Alexey V.; Gregg, Jacob L.; Ziętara, Marek S.

2016-01-01

We examined the global mitochondrial phylogeography of Gyrodactylus arcuatus, a flatworm ectoparasite of three-spined stickleback Gasterosteus aculeatus. In accordance with the suggested high divergence rate of 13%/million years, the genetic variation of the parasite was high: haplotype diversity h = 0.985 and nucleotide diversity π = 0.0161. The differentiation among the parasite populations was substantial (Φst = 0.759), with two main allopatric clades (here termed Euro and North) accounting for 54% of the total genetic variation. The diversity center of the Euro clade was in the Baltic Sea, while the North clade was spread across the Barents and White Seas. A single haplotype within the North clade was found in the western and eastern Pacific Ocean. Divergence of main clades was estimated to be circa 200 thousand years ago. Each main clade was further divided into six distinct subclades, estimated to have diverged in isolation since 135 thousand years ago. This second division corresponds approximately to the Eemian interglacial predating the last glacial maximum. A demographic expansion of the subclades is associated with colonisation of northern Europe since the last glacial maximum, circa 15–40 thousand years ago. The parasite phylogeny is most likely explained by sequential isolated bottlenecks and expansions in numerous allopatric refugia. The postglacial intermingling and high variation in the marine parasite populations, separately in the Baltic and Barents Seas, suggest low competition of divergent parasite matrilines, coupled with a large population size and high rate of dispersal of hosts. The genetic contribution of the assumed refugial fish populations maintaining the parasite during the last glacial maximum was not detected among the marine sticklebacks, which perhaps were infected after range expansion.

Spatial phenotypic and genetic structure of threespine stickleback (Gasterosteus aculeatus) in a heterogeneous natural system, Lake Mývatn, Iceland.

Science.gov (United States)

Millet, Antoine; Kristjánsson, Bjarni K; Einarsson, Arni; Räsänen, Katja

2013-09-01

Eco-evolutionary responses of natural populations to spatial environmental variation strongly depend on the relative strength of environmental differences/natural selection and dispersal/gene flow. In absence of geographic barriers, as often is the case in lake ecosystems, gene flow is expected to constrain adaptive divergence between environments - favoring phenotypic plasticity or high trait variability. However, if divergent natural selection is sufficiently strong, adaptive divergence can occur in face of gene flow. The extent of divergence is most often studied between two contrasting environments, whereas potential for multimodal divergence is little explored. We investigated phenotypic (body size, defensive structures, and feeding morphology) and genetic (microsatellites) structure in threespine stickleback (Gasterosteus aculeatus) across five habitat types and two basins (North and South) within the geologically young and highly heterogeneous Lake Mývatn, North East Iceland. We found that (1) North basin stickleback were, on average, larger and had relatively longer spines than South basin stickleback, whereas (2) feeding morphology (gill raker number and gill raker gap width) differed among three of five habitat types, and (3) there was only subtle genetic differentiation across the lake. Overall, our results indicate predator and prey mediated phenotypic divergence across multiple habitats in the lake, in face of gene flow.

Fluctuations and trends in structure of fish community in Koporskaya Bay coastal waters (Gulf of Finland, Baltic Sea) and influence of water-intake facilities of the Leningrad nuclear power plant on fish fauna

International Nuclear Information System (INIS)

Zimin, V.L.

1996-01-01

The investigation is based on data obtained in 1978-1995 in Koporskaya Bay (eastern part of the Gulf of Finland), known as the cooling water-body of Leningrad (St. Petersburg) nuclear power plant Leningrad (NPP). 45 fish species were recorded in this period. The fish species diversity reduced significantly in last decade (from 8-9 in early 1980s up to 4-5 species in the nucleus of fish community in 1990s). Most vulnerable species, such as salmonids and coregonids, tend to disappear. Koporskaya Bay coastal area is now dominated by abundant three-spined and nine-spined sticklebacks. However, the relatively improved situation have occurred after beginning of reparation works at the 1st reactor unit, when the thermal loading was declined significantly. Great amount of fishes were perished at the water-intake facilities (more than 400 ton/year, in average). Changes in fish community structure caused noticeable changes in commercial fishing: the average percentage part of baltic herring (main object of fishing in the eastern Gulf of Finland) in commercial catches ranged from 90 up to 98% in the time before the LNPP started in operating, but from 1975, especially in last decade when LNPP has reached their project electrical capacity in 1981, we can see significant variations in herring's share (29-80%) in catches

Preference for cannibalism and ontogenetic constraints in competitive ability of piscivorous top predators.

Directory of Open Access Journals (Sweden)

Pär Byström

Full Text Available Occurrence of cannibalism and inferior competitive ability of predators compared to their prey have been suggested to promote coexistence in size-structured intraguild predation (IGP systems. The intrinsic size-structure of fish provides the necessary prerequisites to test whether the above mechanisms are general features of species interactions in fish communities where IGP is common. We first experimentally tested whether Arctic char (Salvelinus alpinus were more efficient as a cannibal than as an interspecific predator on the prey fish ninespine stickleback (Pungitius pungitius and whether ninespine stickleback were a more efficient competitor on the shared zooplankton prey than its predator, Arctic char. Secondly, we performed a literature survey to evaluate if piscivores in general are more efficient as cannibals than as interspecific predators and whether piscivores are inferior competitors on shared resources compared to their prey fish species. Both controlled pool experiments and outdoor pond experiments showed that char imposed a higher mortality on YOY char than on ninespine sticklebacks, suggesting that piscivorous char is a more efficient cannibal than interspecific predator. Estimates of size dependent attack rates on zooplankton further showed a consistently higher attack rate of ninespine sticklebacks compared to similar sized char on zooplankton, suggesting that ninespine stickleback is a more efficient competitor than char on zooplankton resources. The literature survey showed that piscivorous top consumers generally selected conspecifics over interspecific prey, and that prey species are competitively superior compared to juvenile piscivorous species in the zooplankton niche. We suggest that the observed selectivity for cannibal prey over interspecific prey and the competitive advantage of prey species over juvenile piscivores are common features in fish communities and that the observed selectivity for cannibalism over

Preference for cannibalism and ontogenetic constraints in competitive ability of piscivorous top predators.

Science.gov (United States)

Byström, Pär; Ask, Per; Andersson, Jens; Persson, Lennart

2013-01-01

Occurrence of cannibalism and inferior competitive ability of predators compared to their prey have been suggested to promote coexistence in size-structured intraguild predation (IGP) systems. The intrinsic size-structure of fish provides the necessary prerequisites to test whether the above mechanisms are general features of species interactions in fish communities where IGP is common. We first experimentally tested whether Arctic char (Salvelinus alpinus) were more efficient as a cannibal than as an interspecific predator on the prey fish ninespine stickleback (Pungitius pungitius) and whether ninespine stickleback were a more efficient competitor on the shared zooplankton prey than its predator, Arctic char. Secondly, we performed a literature survey to evaluate if piscivores in general are more efficient as cannibals than as interspecific predators and whether piscivores are inferior competitors on shared resources compared to their prey fish species. Both controlled pool experiments and outdoor pond experiments showed that char imposed a higher mortality on YOY char than on ninespine sticklebacks, suggesting that piscivorous char is a more efficient cannibal than interspecific predator. Estimates of size dependent attack rates on zooplankton further showed a consistently higher attack rate of ninespine sticklebacks compared to similar sized char on zooplankton, suggesting that ninespine stickleback is a more efficient competitor than char on zooplankton resources. The literature survey showed that piscivorous top consumers generally selected conspecifics over interspecific prey, and that prey species are competitively superior compared to juvenile piscivorous species in the zooplankton niche. We suggest that the observed selectivity for cannibal prey over interspecific prey and the competitive advantage of prey species over juvenile piscivores are common features in fish communities and that the observed selectivity for cannibalism over interspecific prey has

Regulatory Architecture of Gene Expression Variation in the Threespine Stickleback Gasterosteus aculeatus

Directory of Open Access Journals (Sweden)

Victoria L. Pritchard

2017-01-01

Full Text Available Much adaptive evolutionary change is underlain by mutational variation in regions of the genome that regulate gene expression rather than in the coding regions of the genes themselves. An understanding of the role of gene expression variation in facilitating local adaptation will be aided by an understanding of underlying regulatory networks. Here, we characterize the genetic architecture of gene expression variation in the threespine stickleback (Gasterosteus aculeatus, an important model in the study of adaptive evolution. We collected transcriptomic and genomic data from 60 half-sib families using an expression microarray and genotyping-by-sequencing, and located expression quantitative trait loci (eQTL underlying the variation in gene expression in liver tissue using an interval mapping approach. We identified eQTL for several thousand expression traits. Expression was influenced by polymorphism in both cis- and trans-regulatory regions. Trans-eQTL clustered into hotspots. We did not identify master transcriptional regulators in hotspot locations: rather, the presence of hotspots may be driven by complex interactions between multiple transcription factors. One observed hotspot colocated with a QTL recently found to underlie salinity tolerance in the threespine stickleback. However, most other observed hotspots did not colocate with regions of the genome known to be involved in adaptive divergence between marine and freshwater habitats.

Low genetic and phenotypic divergence in a contact zone between freshwater and marine sticklebacks: gene flow constrains adaptation

DEFF Research Database (Denmark)

Pedersen, Susanne Holst; Ferchaud, Anne-Laure; Bertelsen, Mia Smedegaard

2017-01-01

Background: Distinct hybrid zones and phenotypic and genomic divergence is often observed between marine and freshwater threespine sticklebacks (Gasterosteus aculeatus). Nevertheless, cases also exist where marinefreshwater divergence is diffuse despite seemingly similar environmental settings...

Detection of immunotoxic effects of estrogenic and androgenic endocrine disrupting compounds using splenic immune cells of the female three-spined stickleback, Gasterosteus aculeatus (L.).

Science.gov (United States)

Bado-Nilles, A; Techer, R; Porcher, J M; Geffard, A; Gagnaire, B; Betoulle, S; Sanchez, W

2014-09-01

Today, the list of endocrine disrupting compounds (EDCs) in freshwater and marine environments that mimic or block endogenous hormones is expanding at an alarming rate. As immune and reproductive systems may interact in a bidirectional way, some authors proposed the immune capacities as attractive markers to evaluate the hormonal potential of environmental samples. Thus, the present work proposed to gain more knowledge on direct biological effects of natural and EDCs on female fish splenic leucocyte non-specific immune activities by using ex vivo assays. After determining the optimal required conditions to analyze splenic immune responses, seven different EDCs were tested ex vivo at 0.01, 1 and 100nM over 12h on the leucocyte functions of female three-spined stickleback, Gasterosteus aculeatus. In summary, we found that natural hormones acted as immunostimulants, whilst EDCs were immunosuppressive. Copyright © 2014 Elsevier B.V. All rights reserved.

The European sea bass Dicentrarchus labrax genome puzzle: comparative BAC-mapping and low coverage shotgun sequencing

Directory of Open Access Journals (Sweden)

Volckaert Filip AM

2010-01-01

Full Text Available Abstract Background Food supply from the ocean is constrained by the shortage of domesticated and selected fish. Development of genomic models of economically important fishes should assist with the removal of this bottleneck. European sea bass Dicentrarchus labrax L. (Moronidae, Perciformes, Teleostei is one of the most important fishes in European marine aquaculture; growing genomic resources put it on its way to serve as an economic model. Results End sequencing of a sea bass genomic BAC-library enabled the comparative mapping of the sea bass genome using the three-spined stickleback Gasterosteus aculeatus genome as a reference. BAC-end sequences (102,690 were aligned to the stickleback genome. The number of mappable BACs was improved using a two-fold coverage WGS dataset of sea bass resulting in a comparative BAC-map covering 87% of stickleback chromosomes with 588 BAC-contigs. The minimum size of 83 contigs covering 50% of the reference was 1.2 Mbp; the largest BAC-contig comprised 8.86 Mbp. More than 22,000 BAC-clones aligned with both ends to the reference genome. Intra-chromosomal rearrangements between sea bass and stickleback were identified. Size distributions of mapped BACs were used to calculate that the genome of sea bass may be only 1.3 fold larger than the 460 Mbp stickleback genome. Conclusions The BAC map is used for sequencing single BACs or BAC-pools covering defined genomic entities by second generation sequencing technologies. Together with the WGS dataset it initiates a sea bass genome sequencing project. This will allow the quantification of polymorphisms through resequencing, which is important for selecting highly performing domesticated fish.

Males do not see only red: UV wavelengths and male territorial aggression in the three-spined stickleback ( Gasterosteus aculeatus)

Science.gov (United States)

Rick, Ingolf P.; Bakker, Theo C. M.

2008-07-01

Animal colour signals serve important functions in intraspecific interactions, including species recognition, mate choice and agonistic behaviour. An increasing interest concerns ultraviolet (UV) wavelengths, for instance studies on the effect of UV in mating decisions. More recently, some studies also established that UV signals affect intrasexual interactions. We studied the role of UV during aggressive encounters between male three-spined sticklebacks ( Gasterosteus aculeatus), a species in which UV has an effect on female and male mate choice and shoaling behaviour. To that aim, we compared the aggressive response of a territorial male to male intruders, either seen in UV-including (UV+) or UV-lacking (UV-) conditions. Our prediction was that, if UV wavelengths are used in male-male competition, a territorial male should show less competitive behaviour towards an intruder representing a lower threat, i.e. the one presented without UV light. Male sticklebacks showed significantly lower levels of aggression towards male opponents lacking an UV component to their coloration than male opponents possessing this colour component. Discrimination was not influenced by a difference in brightness between the UV+ and UV- stimuli. Finally, we present some reflectance-spectrophotometrical data of two skin regions (cheek and abdomen) of the experimental males and analysed relationships between colorimetric variables, body variables and behaviour. Our study emphasises that UV visual cues are of importance in different communicational tasks in the three-spined stickleback.

Repeatability of decision-making behaviour in male threespine stickleback Gasterosteus aculeatus: Effects of dummy vs. live stimuli

Directory of Open Access Journals (Sweden)

Teresa L. DZIEWECZYNSKI, Lindsay M. FORRETTE

2011-02-01

Full Text Available Individuals select from a number of behaviours when responding to various situations and the decisions they make may affect their fitness. The costs and benefits of these responses vary among individuals causing them to differ even in identical situations. One example of this type of situation is when territorial males encounter both a male and female simultaneously, gene- rating a trade-off that likely leads to individual differences due to differing costs of various actions among males. This situation commonly occurs in threespine stickleback, Gasterosteus aculeatus. However, for selection to act effectively, individuals must behave in a consistent manner and measuring repeatability can aid in understanding how selection may shape such trade-offs. Males of this species exhibit consistent individual differences in their response to dummy males and females but it is unknown if patterns are similar when feedback from the stimuli is present. To assess this, male threespine stickleback were tested with dummy and live male and female conspecifics, presented separately and simultaneously. While the same trends were found regardless of stimulus type, males were more aggressive towards the live conspecifics than to the dummies. Repeatability values were similar within a treatment regardless of whether live or dummy conspecifics were used, suggesting that individuals show the same level of consistency. This study adds to our understanding of consistent individual differences by demonstrating that feedback may not affect responses to conflicting stimuli and that male threespine stickleback respond in a consistent manner to both dummy and live stimuli [Current Zoology 57 (1: 101–108, 2011].

The role of the nervous system in fish evolution

Directory of Open Access Journals (Sweden)

Michael H Hofmann

2015-12-01

Full Text Available The nervous system plays an important role in the evolution and adaptation of animals. All sensory and motor functions as well as cognitive abilities are organized in the brain and spinal cord. Volumetric measurements of different brain regions were made in more than 150 species of ray finned fishes as well as in several outgroups. In Actanthopterygii, the hypothalamus shows greatest enlargement most likely due to an enormous visual input via the nucleus glomerulosos. The telencephalon is highly differentiated in many acanthopterygii, mostly coral reef species, but its relative size is not much effected. There is, however, a clear shift from olfactory to visual functions in ray finned fishes. In species with a highly differentiated telencephalon, the area where place memory may be located is very prominent. In basal ray finned fishes, lungfish, amphibia and elasmobranchs, the olfactory bulb is relatively large and the ratio of the olfactory bulb and telencephalon large as well. This holds also for elopomorpha and spiny eels, but in most other groups vision dominates. Apart from differences between larger clades, variation in brain architecture are also seen in closely related species and even between sexes of the same species. Profound differences are present in the cerebellum between male and female swordtails and in the telencephalon of sticklebacks. Morphometric analysis of brain architecture turned out to be an important tool to study the evolution and adaptations of the brain in fishes.

Factors affecting the recovery of fish populations in an industrial river. [Brown trout

Energy Technology Data Exchange (ETDEWEB)

Turnpenny, A W.M.; Williams, R

1981-01-01

The river Ebbw Fawr, an industrial river of South-East Wales, was investigated over a three-year period to follow the re-establishment of fish populations as a result of pollution control measures at coal washeries and a steelworks on the river. These measures were effective in reducing levels of toxic materials and restoring dissolved oxygen levels and pH values acceptable for fish. Five freshwater fish species became established in parts of the river during the study period (1974-77). The brown trout Salmo trutta l. was the first to enter, followed by eel Anguilla anguilla l., stoneloach Noemacheilus barbatulus l., stickleback Gasterosteus aculeatus l. and bullhead Cottus gobio l., respectively. The flounder Platicthys flesus l., a euryhaline species, penetrated the river beyond the upper tidal limit. The minnow Phoxinus phoxinus l., a resident of other parts of the Ebbw system, did not recolonise during the study. Calculated toxicities and the results of fish caging tests indicated that water quality was satisfactory for fish populations throughout the river with the possible exception of a short reach immediately below the steelworks. The absence of fish from some upstream reaches with good water quality was due to the limited numbers of fish available for recolonisation and their restricted movements. Good growth and condition factors among the recolonising brown trout stock suggest that a sport fishery could be developed on the river, though constraints on spawning due to residual silt pollution indicate that stocking with hatchery reared fish will be necessary to maintain trout numbers.

Regulatory Architecture of Gene Expression Variation in the Threespine Stickleback Gasterosteus aculeatus.

Science.gov (United States)

Pritchard, Victoria L; Viitaniemi, Heidi M; McCairns, R J Scott; Merilä, Juha; Nikinmaa, Mikko; Primmer, Craig R; Leder, Erica H

2017-01-05

Much adaptive evolutionary change is underlain by mutational variation in regions of the genome that regulate gene expression rather than in the coding regions of the genes themselves. An understanding of the role of gene expression variation in facilitating local adaptation will be aided by an understanding of underlying regulatory networks. Here, we characterize the genetic architecture of gene expression variation in the threespine stickleback (Gasterosteus aculeatus), an important model in the study of adaptive evolution. We collected transcriptomic and genomic data from 60 half-sib families using an expression microarray and genotyping-by-sequencing, and located expression quantitative trait loci (eQTL) underlying the variation in gene expression in liver tissue using an interval mapping approach. We identified eQTL for several thousand expression traits. Expression was influenced by polymorphism in both cis- and trans-regulatory regions. Trans-eQTL clustered into hotspots. We did not identify master transcriptional regulators in hotspot locations: rather, the presence of hotspots may be driven by complex interactions between multiple transcription factors. One observed hotspot colocated with a QTL recently found to underlie salinity tolerance in the threespine stickleback. However, most other observed hotspots did not colocate with regions of the genome known to be involved in adaptive divergence between marine and freshwater habitats. Copyright © 2017 Pritchard et al.

Effects of chronic exposure to cadmium and temperature, alone or combined, on the threespine stickleback (Gasterosteus aculeatus): Interest of digestive enzymes as biomarkers.

Science.gov (United States)

Hani, Younes Mohamed Ismail; Turies, Cyril; Palluel, Olivier; Delahaut, Laurence; Gaillet, Véronique; Bado-Nilles, Anne; Porcher, Jean-Marc; Geffard, Alain; Dedourge-Geffard, Odile

2018-06-01

The development of predictive, sensitive and reliable biomarkers is of crucial importance for aquatic biomonitoring to assess the effects of chemical substances on aquatic organisms, especially when it comes to combined effects with other stressors (e.g. temperature). The first purpose of the present study was to evaluate the single and combined effects of 90 days of exposure to an environmental cadmium concentration (0.5 μg L -1 ) and two water temperatures (16 and 21 °C) on different parameters. These parameters are involved in (i) the antioxidant system (superoxide dismutase activity -SOD- and total glutathione levels -GSH-), (ii) the energy metabolism, i.e. energy reserves (glycogen, lipids, proteins) and digestive enzymes (trypsin, amylase, intestinal alkaline phosphatase -IAP-), and (iii) biometric parameters (weight, length, Fulton's condition factor, and the gonadosomatic index -GSI-) of threespine stickleback (Gasterosteus aculeatus). The second purpose was to determine the interest of the three digestive enzymes as biomarkers in comparison with the other parameters. The higher temperature (21 °C) impacted the anti-oxidant and energy reserve parameters. In liver, GSH levels increased on day 60, while SOD decreased on days 15 and 90, with a significant decrease of protein and lipid energy reserves on day 90. In muscle, the higher temperature decreased SOD activity only on day 90. G. aculeatus biometric parameters were also impacted by the higher temperature, which limited stickleback growth after 90 days of exposure. In female sticklebacks, the GSI peaked on day 60 and decreased sharply on day 90, while the highest values were reached at day 90 in the control groups, suggesting impaired reproduction in sticklebacks raised at 21 °C. These results suggest that 21 °C is an upper-limit temperature for long-term physiological processes in sticklebacks. In contrast, very low-concentration cadmium exposure had no effect on classical biomarkers

A low-density SNP array for analyzing differential selection in freshwater and marine populations of threespine stickleback (Gasterosteus aculeatus)

DEFF Research Database (Denmark)

Ferchaud, Anne-Laure; Pedersen, Susanne H.; Bekkevold, Dorte

2014-01-01

for rapid and cost efficient analysis of genetic divergence between freshwater and marine sticklebacks, we generated a low-density SNP (Single Nucleotide Polymorphism) array encompassing markers of chromosome regions under putative directional selection, along with neutral markers for background. Results......: RAD (Restriction site Associated DNA) sequencing of sixty individuals representing two freshwater and one marine population led to the identification of 33,993 SNP markers. Ninety-six of these were chosen for the low-density SNP array, among which 70 represented SNPs under putatively directional...... selection in freshwater vs. marine environments, whereas 26 SNPs were assumed to be neutral. Annotation of these regions revealed several genes that are candidates for affecting stickleback phenotypic variation, some of which have been observed in previous studies whereas others are new. Conclusions: We...

Female sticklebacks use male coloration in mate choice and hence avoid parasitized males

Science.gov (United States)

Milinski, Manfred; Bakker, Theo C. M.

1990-03-01

AN important problem in evolutionary biology since the time of Darwin has been to understand why females preferentially mate with males handicapped by secondary sexual ornaments1-3. One hypothesis of sexual selection theory is that these ornaments reliably reveal the male's condition4-6, which can be affected for example by parasites4,7-13. Here we show that in the three-spined stickleback (Gasterosteus aculeatus) the intensity of male red breeding coloration positively correlates with physical condition. Gravid females base their active mate choice on the intensity of the male's red coloration. Choice experiments under green light prevent the use of red colour cues by females, and males that were previously preferred are now chosen no more than randomly, although the courtship behaviour of the males remains unchanged. Parasitieation causes a deterioration in the males' condition and a decrease in the intensity of their red coloration. Tests under both lighting conditions reveal that the females recognize the formerly parasitized males by the lower intensity of their breeding coloration. Female sticklebacks possibly select a male with a good capacity for paternal care14 but if there is additive genetic variation for parasite resistance, then they might also select for resistance genes, as proposed by Hamilton and Zuk4.

Quorum decision-making in foraging fish shoals.

Directory of Open Access Journals (Sweden)

Ashley J W Ward

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

No effect of a parasite on reproduction in stickleback males: a laboratory artefact?

OpenAIRE

Candolin, U.; Voigt, H.-R.

2001-01-01

Experiments are often carried out in the laboratory under arti®cial conditions. Although this can control for confounding factors, it may eliminate important factors that under natural conditions mediate the interaction under investigation. Here, we show that different results can be gained in the ®eld and in the laboratory regarding host±parasite interaction. In the ®eld, courting three-spined stickleback males, Gasterosteus aculeatus, were less often infected with plerocercoids of ...

[THE MICROSPORIDIUM GLUGEA GASTEROSTEI VORONIN 1974 (MICROSPORIDIA: MARINOSPORIDIA) FROM THE THREE-SPINED STICKLEBACK GASTEROSTEUS ACULEATUS (ACTINOPTERYGII: GASTEROSTEIFORMES) AS AN INDEPENDENT SPECIES].

Science.gov (United States)

Tokarev, Y S; Voronin, V N; Senderskiy, I V; Issi, I V

2015-01-01

The microsporidium Glugea gasterostei from the three-spined stickleback Gasterosteus aculeatus was described as an independent species basing upon morphological and ecological traits of the parasite (Voronin, 1974), further supported by ultrastructural characters of its spores (Voronin, 1983). During the revision of microsporidia of the genus Glugea (Canning, Lom, 1986; Lom, 2002), the validity of this species was doubted and it was synonymized with G. anomala. Nevertheless, the molecular phylogenetic analysis performed in the present study showed the unique molecular haplotype of small subunit rRNA gene of G. gasterostei (Genbank accession number KM977990) and its close relatedness to G. anomala, G. atherinae and G. hertwigi (sequence similarity of 99.7 %). One of typical characters of G. gasterostei, as opposed to G. anomala, is the formation of xenomas on inner tissues and not on the surface of infected fishes. This feature is retained even after the infection of different host species. Taken together, these data confirm the validity of G. gasterostei as a separate species among closely related taxa that had diverged comparatively recently.

Relaxin-related gene expression differs between anadromous and stream-resident stickleback (Gasterosteus aculeatus) following seawater transfer.

Science.gov (United States)

Kusakabe, Makoto; Ishikawa, Asano; Kitano, Jun

2014-09-01

Relaxin (RLN) is a hormone that was originally identified as a regulator of pregnancy and reproduction. However, recent mammalian studies have demonstrated that relaxins also have potent osmoregulatory actions. In mammals, six relaxin family peptides have been identified: RLN1/2, RLN3, insulin-like peptide (INSL) 3, INSL4, INSL5, and INSL6. Previous genome database searches have revealed that teleosts also possess multiple relaxin family genes. However, the functions of these relaxin family peptides in teleosts remain unclear. In order to gain insight into the osmoregulatory functions of teleost relaxins, we studied the relaxin family peptides in euryhaline three-spined sticklebacks (Gasterosteus aculeatus), which have diversified into a variety of ecotypes. Rln3a, rln3b, and rln transcripts were abundant in the stickleback brain, whereas insl5b transcript levels were highest in the intestine among tissues. Seawater challenge experiments showed that transcript levels of rln3a, rln3b, and rln in the brain changed significantly after seawater transfer. Particularly, rln3b showed different patterns of temporal changes between anadromous and stream-resident morphs. The transcript levels of relaxin family peptide receptors, rxfp1, rxfp2b, rxfp3-2a, and rxfp3-2b, did not exhibit substantial changes in the brain, although these were constantly higher in the anadromous morph than the stream-resident morph. These results suggest that stickleback relaxin systems are differentially regulated by salinity signals, at least at the transcriptional level, and anadromous and stream-resident morphs differ in relaxin signaling pathways. The differences in the expression of relaxin-related genes between these two morphs provide a foundation for further exploration of the osmoregulatory function of relaxins in teleosts. Copyright © 2014 Elsevier Inc. All rights reserved.

Increased noise levels have different impacts on the anti-predator behaviour of two sympatric fish species.

Directory of Open Access Journals (Sweden)

Irene K Voellmy

Full Text Available Animals must avoid predation to survive and reproduce, and there is increasing evidence that man-made (anthropogenic factors can influence predator-prey relationships. Anthropogenic noise has been shown to have a variety of effects on many species, but work investigating the impact on anti-predator behaviour is rare. In this laboratory study, we examined how additional noise (playback of field recordings of a ship passing through a harbour, compared with control conditions (playback of recordings from the same harbours without ship noise, affected responses to a visual predatory stimulus. We compared the anti-predator behaviour of two sympatric fish species, the three-spined stickleback (Gasterosteus aculeatus and the European minnow (Phoxinus phoxinus, which share similar feeding and predator ecologies, but differ in their body armour. Effects of additional-noise playbacks differed between species: sticklebacks responded significantly more quickly to the visual predatory stimulus during additional-noise playbacks than during control conditions, while minnows exhibited no significant change in their response latency. Our results suggest that elevated noise levels have the potential to affect anti-predator behaviour of different species in different ways. Future field-based experiments are needed to confirm whether this effect and the interspecific difference exist in relation to real-world noise sources, and to determine survival and population consequences.

High degree of genetic differentiation in marine three-spined sticklebacks (Gasterosteus aculeatus).

Science.gov (United States)

Defaveri, Jacquelin; Shikano, Takahito; Shimada, Yukinori; Merilä, Juha

2013-09-01

Populations of widespread marine organisms are typically characterized by a low degree of genetic differentiation in neutral genetic markers, but much less is known about differentiation in genes whose functional roles are associated with specific selection regimes. To uncover possible adaptive population divergence and heterogeneous genomic differentiation in marine three-spined sticklebacks (Gasterosteus aculeatus), we used a candidate gene-based genome-scan approach to analyse variability in 138 microsatellite loci located within/close to (<6 kb) functionally important genes in samples collected from ten geographic locations. The degree of genetic differentiation in markers classified as neutral or under balancing selection-as determined with several outlier detection methods-was low (F(ST) = 0.033 or 0.011, respectively), whereas average FST for directionally selected markers was significantly higher (F(ST) = 0.097). Clustering analyses provided support for genomic and geographic heterogeneity in selection: six genetic clusters were identified based on allele frequency differences in the directionally selected loci, whereas four were identified with the neutral loci. Allelic variation in several loci exhibited significant associations with environmental variables, supporting the conjecture that temperature and salinity, but not optic conditions, are important drivers of adaptive divergence among populations. In general, these results suggest that in spite of the high degree of physical connectivity and gene flow as inferred from neutral marker genes, marine stickleback populations are strongly genetically structured in loci associated with functionally relevant genes. © 2013 John Wiley & Sons Ltd.

Characterization of antibodies for quantitative determination of spiggin protein levels in male and female three-spined stickleback (Gasterosteus aculeatus

Directory of Open Access Journals (Sweden)

Karlsson Johnny

2009-05-01

Full Text Available Abstract Spiggin is an adhesive glycoprotein produced in the kidney of sticklebacks during the breeding season and is subsequently secreted into the urinary bladder from where it is employed for nest building. Since the production of the protein has been shown to be under androgenic control, spiggin has been suggested to be a useful biomarker for androgenic substances in the environment. In this study, two polyclonal spiggin antibodies based on synthetic peptides and one polyclonal antibody directed against native spiggin have been characterized. The antibodies ability to identify spiggin was investigated by quantitative immunoassay. For both peptide antibodies the quantification range was determined to be between 1 and 80 ng spiggin and determination of renal spiggin levels from immature and mature males displayed a 15-fold increase in total spiggin content of the kidney resulting in a 6-fold increase in male kidney weight due to hypertrophy. The kidney somatic index (KSI was found to correlate well with the total renal spiggin content and therefore it appears that KSI in sticklebacks could be used as an initial method to identify substances displaying androgenic effects. Furthermore, western blot analysis revealed that the polyclonal antibodies recognize different spiggin isoforms and that spiggin can be detected in the urinary bladder and kidney of both males and female sticklebacks. In order to develop a quantitative detection method for native spiggin it is necessary to produce a standard that can be used in a bioassay. Due to the adhesive and polymerization characteristics of spiggin the protein is difficult to use as a standard in bioassays. So far spiggin has been shown to exist in at least 14 isoforms, all of which contain polymerization domains. To overcome the solubility problem we have produced recombinant spiggin gamma, with only one polymerization domain, that can be expressed in E. coli. Western blot analysis demonstrated that the

Deciphering the genomic architecture of the stickleback brain with a novel multilocus gene-mapping approach.

Science.gov (United States)

Li, Zitong; Guo, Baocheng; Yang, Jing; Herczeg, Gábor; Gonda, Abigél; Balázs, Gergely; Shikano, Takahito; Calboli, Federico C F; Merilä, Juha

2017-03-01

Quantitative traits important to organismal function and fitness, such as brain size, are presumably controlled by many small-effect loci. Deciphering the genetic architecture of such traits with traditional quantitative trait locus (QTL) mapping methods is challenging. Here, we investigated the genetic architecture of brain size (and the size of five different brain parts) in nine-spined sticklebacks (Pungitius pungitius) with the aid of novel multilocus QTL-mapping approaches based on a de-biased LASSO method. Apart from having more statistical power to detect QTL and reduced rate of false positives than conventional QTL-mapping approaches, the developed methods can handle large marker panels and provide estimates of genomic heritability. Single-locus analyses of an F 2 interpopulation cross with 239 individuals and 15 198, fully informative single nucleotide polymorphisms (SNPs) uncovered 79 QTL associated with variation in stickleback brain size traits. Many of these loci were in strong linkage disequilibrium (LD) with each other, and consequently, a multilocus mapping of individual SNPs, accounting for LD structure in the data, recovered only four significant QTL. However, a multilocus mapping of SNPs grouped by linkage group (LG) identified 14 LGs (1-6 depending on the trait) that influence variation in brain traits. For instance, 17.6% of the variation in relative brain size was explainable by cumulative effects of SNPs distributed over six LGs, whereas 42% of the variation was accounted for by all 21 LGs. Hence, the results suggest that variation in stickleback brain traits is influenced by many small-effect loci. Apart from suggesting moderately heritable (h 2  ≈ 0.15-0.42) multifactorial genetic architecture of brain traits, the results highlight the challenges in identifying the loci contributing to variation in quantitative traits. Nevertheless, the results demonstrate that the novel QTL-mapping approach developed here has distinctive advantages

From "Duck Factory" to "Fish Factory": Climate induced changes in vertebrate communities of prairie pothole wetlands and small lakes

Science.gov (United States)

McLean, Kyle I.; Mushet, David M.; Stockwell, Craig A.

2016-01-01

The Prairie Pothole Region’s myriad wetlands and small lakes contribute to its stature as the “duck factory” of North America. The fishless nature of the region’s aquatic habitats, a result of frequent drying, freezing, and high salinity, influences its importance to waterfowl. Recent precipitation increases have resulted in higher water levels and wetland/lake freshening. In 2012–13, we sampled chemical characteristics and vertebrates (fish and salamanders) of 162 Prairie Pothole wetlands and small lakes. We used non-metric multidimensional scaling, principal component analysis, and bootstrapping techniques to reveal relationships. We found fish present in a majority of sites (84 %). Fish responses to water chemistry varied by species. Fathead minnows (Pimephales promelas) and brook sticklebacks (Culaea inconstans) occurred across the broadest range of conditions. Yellow perch (Perca flavescens) occurred in a smaller, chemically defined, subset. Iowa darters (Etheostoma exile) were restricted to the narrowest range of conditions. Tiger salamanders (Ambystoma mavortium) rarely occurred in lakes with fish. We also compared our chemical data to similar data collected in 1966–1976 to explore factors contributing to the expansion of fish into previously fishless sites. Our work contributes to a better understanding of relationships between aquatic biota and climate-induced changes in this ecologically important area.

The ecology of an adaptive radiation of three?spined stickleback from North Uist, Scotland

OpenAIRE

Magalhaes, Isabel S.; D'Agostino, Daniele; Hohenlohe, Paul A.; MacColl, Andrew D. C.

2016-01-01

Abstract There has been a large focus on the genetics of traits involved in adaptation, but knowledge of the environmental variables leading to adaptive changes is surprisingly poor. Combined use of environmental data with morphological and genomic data should allow us to understand the extent to which patterns of phenotypic and genetic diversity within a species can be explained by the structure of the environment. Here, we analyse the variation of populations of three?spined stickleback fro...

Temporal stability of genetic variability and differentiation in the three-spined stickleback (Gasterosteus aculeatus).

Science.gov (United States)

DeFaveri, Jacquelin; Merilä, Juha

2015-01-01

Temporal variation in allele frequencies, whether caused by deterministic or stochastic forces, can inform us about interesting demographic and evolutionary phenomena occurring in wild populations. In spite of the continued surge of interest in the genetics of three-spined stickleback (Gasterosteus aculeatus) populations, little attention has been paid towards the temporal stability of allele frequency distributions, and whether there are consistent differences in effective size (Ne) of local populations. We investigated temporal stability of genetic variability and differentiation in 15 microsatellite loci within and among eight collection sites of varying habitat type, surveyed twice over a six-year time period. In addition, Nes were estimated with the expectation that they would be lowest in isolated ponds, intermediate in larger lakes and largest in open marine sites. In spite of the marked differences in genetic variability and differentiation among the study sites, the temporal differences in allele frequencies, as well as measures of genetic diversity and differentiation, were negligible. Accordingly, the Ne estimates were temporally stable, but tended to be lower in ponds than in lake or marine habitats. Hence, we conclude that allele frequencies in putatively neutral markers in three-spined sticklebacks seem to be temporally stable - at least over periods of few generations - across a wide range of habitat types differing markedly in levels of genetic variability, effective population size and gene flow.

Temporal stability of genetic variability and differentiation in the three-spined stickleback (Gasterosteus aculeatus.

Directory of Open Access Journals (Sweden)

Jacquelin DeFaveri

Full Text Available Temporal variation in allele frequencies, whether caused by deterministic or stochastic forces, can inform us about interesting demographic and evolutionary phenomena occurring in wild populations. In spite of the continued surge of interest in the genetics of three-spined stickleback (Gasterosteus aculeatus populations, little attention has been paid towards the temporal stability of allele frequency distributions, and whether there are consistent differences in effective size (Ne of local populations. We investigated temporal stability of genetic variability and differentiation in 15 microsatellite loci within and among eight collection sites of varying habitat type, surveyed twice over a six-year time period. In addition, Nes were estimated with the expectation that they would be lowest in isolated ponds, intermediate in larger lakes and largest in open marine sites. In spite of the marked differences in genetic variability and differentiation among the study sites, the temporal differences in allele frequencies, as well as measures of genetic diversity and differentiation, were negligible. Accordingly, the Ne estimates were temporally stable, but tended to be lower in ponds than in lake or marine habitats. Hence, we conclude that allele frequencies in putatively neutral markers in three-spined sticklebacks seem to be temporally stable - at least over periods of few generations - across a wide range of habitat types differing markedly in levels of genetic variability, effective population size and gene flow.

Parasites and parallel divergence of the number of individual MHC alleles between sympatric three-spined stickleback Gasterosteus aculeatus morphs in Iceland.

Science.gov (United States)

Natsopoulou, M E; Pálsson, S; Ólafsdóttir, G Á

2012-10-01

Two pairs of sympatric three-spined stickleback Gasterosteus aculeatus morphs and two single morph populations inhabiting mud and lava or rocky benthic habitats in four Icelandic lakes were screened for parasites and genotyped for MHC class IIB diversity. Parasitic infection differed consistently between G. aculeatus from different benthic habitats. Gasterosteus aculeatus from the lava or rocky habitats were more heavily infected in all lakes. A parallel pattern was also found in individual MHC allelic variation with lava G. aculeatus morphs exhibiting lower levels of variation than the mud morphs. Evidence for selective divergence in MHC allele number is ambiguous but supported by two findings in addition to the parallel pattern observed. MHC allele diversity was not consistent with diversity reported at neutral markers (microsatellites) and in Þingvallavatn the most common number of alleles in each morph was associated with lower infection levels. In the Þingvallavatn lava morph, lower infection levels by the two most common parasites, Schistocephalus solidus and Diplostomum baeri, were associated with different MHC allele numbers. © 2012 The Authors. Journal of Fish Biology © 2012 The Fisheries Society of the British Isles.

The structuring role of fish in Greenland lakes: an overview based on contemporary and paleoecological studies of 87 lakes from the low and the high Arctic

DEFF Research Database (Denmark)

Jeppesen, Erik; Lauridsen, Torben L.; Christoffersen, Kirsten S.

2017-01-01

largest between fishless lakes and lakes hosting only sticklebacks (Gasterosteus aculeatus), while lakes with both Arctic charr (Salvelinus arcticus) and stickleback revealed a more modest response, indicating that presence of charr modulates the predation effect of sticklebacks. It is predicted that more...

Spatial distribution of pelagic fish larvae in the northern main basin of Lake Huron

Science.gov (United States)

Roseman, Edward F.; O'Brien, Timothy P.

2013-01-01

Larval fish occurrence in inshore and offshore zones in the northern main basin of Lake Huron was assessed during 2007 as part of a larger ecological examination of Lake Huron foodwebs and habitats. Day and night collections using neuston and conical nets at inshore (1.5–15 m depths) and offshore (37 and 91 m depths) locations at De Tour and Hammond Bay to assess the abundance, phenology, and spatial distribution of pelagic ichthyoplankton during spring and early summer were made. In general, densities of larval fishes were higher at De Tour than Hammond Bay during daytime neuston net collections, with the exception of Longnose Sucker, which were only collected at Hammond Bay. Lake Whitefish, Burbot, and Rainbow Smelt dominated inshore catches in early spring with Cisco, Deepwater Sculpin, Emerald Shiner, Bloater, Slimy Sculpin, Ninespine Stickleback, and Yellow Perch larvae also collected.Nighttime nearshore and offshore sampling revealed that Rainbow Smelt and Burbot larvae were present in relatively high abundances compared to inshore densities. Concentrations of larvae of deepwater demersal fishes such as Lake Whitefish and Deepwater Sculpin suggest that inshore zones in northern Lake Huron are important nursery habitats emphasizing a critical production and recruitment linkage between inshore and deepwater zones.

Excretory products of the cestode, Schistocephalus solidus, modulate in vitro responses of leukocytes from its specific host, the three-spined stickleback (Gasterosteus aculeatus).

Science.gov (United States)

Scharsack, Jörn Peter; Gossens, Anabel; Franke, Frederik; Kurtz, Joachim

2013-12-01

Helminth parasites have evolved remarkable strategies to manipulate the immune system of their hosts. During infections of three-spined stickleback (Gasterosteus aculeatus) with the cestode Schistocephalus solidus prominent immunological changes occur, presumably due to manipulative activity of the parasite. We hypothesise that excretory/secretory products of the parasite are involved in the manipulation of the stickleback's immune system and that this may depend on the individual parasite and its origin. We therefore produced S. solidus conditioned cell culture media (SSCM) with parasites from different origins (Norway, Spain and Germany) and exposed head kidney leukocytes (HKL) from un-infected sticklebacks in cell cultures to SSCM. After in vitro culture, HKL were subjected to differential cell counts (granulocytes/lymphocytes) by means of flow cytometry. Leukocyte sub-populations were analysed for cell viability and changes in cell morphology. The respiratory burst activity was measured with a luminescence assay. Exposure of HKL to SSCM induced an up-regulation of respiratory burst activity after already 1 h, which was still elevated at 24 h, but which was in some cases significantly down-regulated after 96 h. Respiratory burst was positively correlated with the number of live granulocytes in the culture, suggesting that the respiratory burst activity was changed by SSCM effects on granulocyte viability. After 1 h and 24 h of HKL culture, no lymphocyte responses to SSCM were detectable, but after 96 h lymphocyte viability was significantly decreased with SSCM from Spanish S. solidus. In these cultures, residual lymphocytes increased in size, suggesting that cell death and activation might have occurred in parallel. The highest respiratory burst activity was induced by SSCM from Spanish parasites, in particular when they were grown in sympatric sticklebacks. The in vitro HKL responses to SSCM depended on the individual parasite and its population of origin

Housekeeping genes for quantitative expression studies in the three-spined stickleback Gasterosteus aculeatus

Directory of Open Access Journals (Sweden)

Becker Sven

2008-01-01

Full Text Available Abstract Background During the last years the quantification of immune response under immunological challenges, e.g. parasitation, has been a major focus of research. In this context, the expression of immune response genes in teleost fish has been surveyed for scientific and commercial purposes. Despite the fact that it was shown in teleostei and other taxa that the gene for beta-actin is not the most stably expressed housekeeping gene (HKG, depending on the tissue and experimental treatment, the gene has been used as a reference gene in such studies. In the three-spined stickleback, Gasterosteus aculeatus, other HKG than the one for beta-actin have not been established so far. Results To establish a reliable method for the measurement of immune gene expression in Gasterosteus aculeatus, sequences from the now available genome database and an EST library of the same species were used to select oligonucleotide primers for HKG, in order to perform quantitative reverse-transcription (RT PCR. The expression stability of ten candidate reference genes was evaluated in three different tissues, and in five parasite treatment groups, using the three algorithms BestKeeper, geNorm and NormFinder. Our results showed that in most of the tissues and treatments HKG that could not be used so far due to unknown sequences, proved to be more stably expressed than the one for beta-actin. Conclusion As they were the most stably expressed genes in all tissues examined, we suggest using the genes for the L13a ribosomal binding protein and ubiquitin as alternative or additional reference genes in expression analysis in Gasterosteus aculeatus.

Habitat change influences mate search behaviour in three-spined sticklebacks

DEFF Research Database (Denmark)

Heuschele, Jan; Salminen, Tiina; Candolin, Ulrika

2012-01-01

Mate choice is one of the main mechanisms of sexual selection, with profound implications for individual fitness. Changes in environmental conditions can cause individuals to alter their mate search behaviour, with consequences for mate choice. Human-induced eutrophication of water bodies...... is a global problem that alters habitat structure and visibility in aquatic ecosystems. We investigated whether changes in habitat complexity and male cue modality, visual or olfactory, influence mate search behaviour of female three-spined sticklebacks, Gasterosteus aculeatus. We allowed gravid females...... evaluation in the absence of visual stimulation. This reduced the rate of mate encounters and probably also the opportunity for choice. Our results show that changes in habitat structure and visibility can alter female mate searching, with potential consequences for the opportunity for sexual selection....

The Membranes of the Basal Labyrinth in Kidney Cells of the Stickleback, Gasterosteus aculeatus, Studied in Ultrathin Sections and Freeze-Etch Replicas

NARCIS (Netherlands)

Wendelaar Bonga, S.E.; Veenhuis, M.

1974-01-01

The structure of the basal labyrinth in kidney cells of freshwater sticklebacks was studied in ultrathin sections (after fixation with permanganate, osmium tetroxide, and combinations of glutaraldehyde with osmium tetroxide) and in freeze-etch replicas (after pretreatment with glutaraldehyde and/or

Latitudinal variation in photoperiodic response of the three-spined stickleback Gasterosteus aculeatus in western North America

Science.gov (United States)

Yeates-Burghart, Q. S.; O’Brien, C.; Cresko, W. A.; Holzapfel, C. M.; Bradshaw, W. E.

2014-01-01

Reproductive maturation in both male and female three-spined stickleback Gasterosteus aculeatus was strongly photoperiodic in a northern population (Alaska, 61° N) but not in a southern population (Oregon, 43° N) from western North America. Increasing reliance on photoperiod with increasing latitude is a general phenomenon among vertebrates, and is probably due to the anticipation of a narrower window of opportunity for reproduction and development at higher latitudes. PMID:20738673

The mean and variance of climate change in the oceans: hidden evolutionary potential under stochastic environmental variability in marine sticklebacks.

Science.gov (United States)

Shama, Lisa N S

2017-08-21

Increasing climate variability may pose an even greater risk to species than climate warming because temperature fluctuations can amplify adverse impacts of directional warming on fitness-related traits. Here, the influence of directional warming and increasing climate variability on marine stickleback fish (Gasterosteus aculeatus) offspring size variation was investigated by simulating changes to the mean and variance of ocean temperatures predicted under climate change. Reproductive traits of mothers and offspring size reaction norms across four climate scenarios were examined to assess the roles of standing genetic variation, transgenerational and within-generation plasticity in adaptive potential. Mothers acclimated to directional warming produced smaller eggs than mothers in constant, ambient temperatures, whereas mothers in a predictably variable environment (weekly change between temperatures) produced a range of egg sizes, possibly reflecting a diversified bet hedging strategy. Offspring size post-hatch was mostly influenced by genotype by environment interactions and not transgenerational effects. Offspring size reaction norms also differed depending on the type of environmental predictability (predictably variable vs. stochastic), with offspring reaching the largest sizes in the stochastic environment. Release of cryptic genetic variation for offspring size in the stochastic environment suggests hidden evolutionary potential in this wild population to respond to changes in environmental predictability.

Mortality selection during the 2003 European heat wave in three-spined sticklebacks: effects of parasites and MHC genotype

Directory of Open Access Journals (Sweden)

Milinski Manfred

2008-04-01

Full Text Available Abstract Background Ecological interaction strength may increase under environmental stress including temperature. How such stress enhances and interacts with parasite selection is almost unknown. We studied the importance of resistance genes of the major histocompatibility complex (MHC class II in 14 families of three-spined sticklebacks Gasterosteus aculeatus exposed to their natural macroparasites in field enclosures in the extreme summer of 2003. Results After a mass die-off during the 2003-European heat wave killing 78% of 277 experimental fish, we found strong differences in survival among and within families. In families with higher average parasite load fewer individuals survived. Multivariate analysis revealed that the composition of the infecting parasite fauna was family specific. Within families, individuals with an intermediate number of MHC class IIB sequence variants survived best and had the lowest parasite load among survivors, suggesting a direct functional link between MHC diversity and fitness. The within family MHC effects were, however, small compared to between family effects, suggesting that other genetic components or non-genetic effects were also important. Conclusion The correlation between parasite load and mortality that we found at both individual and family level might have appeared only in the extraordinary heatwave of 2003. Due to global warming the frequency of extreme climatic events is predicted to increase, which might intensify costs of parasitism and enhance selection on immune genes.

Contrasting effects of hypoxia on copper toxicity during development in the three-spined stickleback (Gasterosteus aculeatus).

Science.gov (United States)

Fitzgerald, Jennifer A; Katsiadaki, Ioanna; Santos, Eduarda M

2017-03-01

Hypoxia is a global problem in aquatic systems and often co-occurs with pollutants. Despite this, little is known about the combined effects of these stressors on aquatic organisms. The objective of this study was to investigate the combined effects of hypoxia and copper, a toxic metal widespread in the aquatic environment. We used the three-spined stickleback (Gasterosteus aculeatus) as a model because of its environmental relevance and amenability for environmental toxicology studies. We focused on embryonic development as this is considered to be a sensitive life stage to environmental pollution. We first investigated the effects of hypoxia alone on stickleback development to generate the information required to design subsequent studies. Our data showed that exposure to low oxygen concentrations (24.7 ± 0.9% air saturation; AS) resulted in strong developmental delays and increased mortalities, whereas a small decrease in oxygen (75.0 ± 0.5%AS) resulted in premature hatching. Stickleback embryos were then exposed to a range of copper concentrations under hypoxia (56.1 ± 0.2%AS) or normoxia (97.6 ± 0.1%AS), continuously, from fertilisation to free swimming larvae. Hypoxia caused significant changes in copper toxicity throughout embryonic development. Prior to hatching, hypoxia suppressed the occurrence of mortalities, but after hatching hypoxia significantly increased copper toxicity. Interestingly, when exposures were conducted only after hatching, the onset of copper-induced mortalities was delayed under hypoxia compared to normoxia, but after 48 h, copper was more toxic to hatched embryos under hypoxia. This is the second species for which the protective effect of hypoxia on copper toxicity prior to hatching, followed by its exacerbating effect after hatching is demonstrated, suggesting the hypothesis that this pattern may be common for teleost species. Our research highlights the importance of considering the interactions between multiple

Early exposure to nonlethal predation risk by size-selective predators increases somatic growth and decreases size at adulthood in threespined sticklebacks

NARCIS (Netherlands)

Bell, A. M.; Dingemanse, N. J.; Hankison, S. J.; Langenhof, M. B. W.; Rollins, K.

Predation has an important influence on life history traits in many organisms, especially when they are young. When cues of trout were present, juvenile sticklebacks grew faster. The increase in body size as a result of exposure to cues of predators was adaptive because larger individuals were more

Improvement of the Threespine Stickleback Genome Using a Hi-C-Based Proximity-Guided Assembly.

Science.gov (United States)

Peichel, Catherine L; Sullivan, Shawn T; Liachko, Ivan; White, Michael A

2017-09-01

Scaffolding genomes into complete chromosome assemblies remains challenging even with the rapidly increasing sequence coverage generated by current next-generation sequence technologies. Even with scaffolding information, many genome assemblies remain incomplete. The genome of the threespine stickleback (Gasterosteus aculeatus), a fish model system in evolutionary genetics and genomics, is not completely assembled despite scaffolding with high-density linkage maps. Here, we first test the ability of a Hi-C based proximity-guided assembly (PGA) to perform a de novo genome assembly from relatively short contigs. Using Hi-C based PGA, we generated complete chromosome assemblies from a distribution of short contigs (20-100 kb). We found that 96.40% of contigs were correctly assigned to linkage groups (LGs), with ordering nearly identical to the previous genome assembly. Using available bacterial artificial chromosome (BAC) end sequences, we provide evidence that some of the few discrepancies between the Hi-C assembly and the existing assembly are due to structural variation between the populations used for the 2 assemblies or errors in the existing assembly. This Hi-C assembly also allowed us to improve the existing assembly, assigning over 60% (13.35 Mb) of the previously unassigned (~21.7 Mb) contigs to LGs. Together, our results highlight the potential of the Hi-C based PGA method to be used in combination with short read data to perform relatively inexpensive de novo genome assemblies. This approach will be particularly useful in organisms in which it is difficult to perform linkage mapping or to obtain high molecular weight DNA required for other scaffolding methods. © The American Genetic Association 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Extreme sexual brain size dimorphism in sticklebacks: a consequence of the cognitive challenges of sex and parenting?

Directory of Open Access Journals (Sweden)

Alexander Kotrschal

Full Text Available Selection pressures that act differently on males and females produce numerous differences between the sexes in morphology and behaviour. However, apart from the controversial report that males have slightly heavier brains than females in humans, evidence for substantial sexual dimorphism in brain size is scarce. This apparent sexual uniformity is surprising given that sexually distinct selection pressures are ubiquitous and that brains are one of the most plastic vertebrate organs. Here we demonstrate the highest level of sexual brain size dimorphism ever reported in any vertebrate: male three-spined stickleback of two morphs in an Icelandic lake have 23% heavier brains than females. We suggest that this dramatic sexual size dimorphism is generated by the many cognitively demanding challenges that males are faced in this species, such as an elaborate courtship display, the construction of an ornate nest and a male-only parental care system. However, we consider also alternative explanations for smaller brains in females, such as life-history trade-offs. Our demonstration of unprecedented levels of sexual dimorphism in brain size in the three-spined stickleback implies that behavioural and life-history differences among the sexes can have strong effects also on neural development and proposes new fields of research for understanding brain evolution.

A Comparative BAC Map for the Gilthead Sea Bream (Sparus aurata L.

Directory of Open Access Journals (Sweden)

Heiner Kuhl

2011-01-01

Full Text Available This study presents the first comparative BAC map of the gilthead sea bream (Sparus aurata, a highly valuated marine aquaculture fish species in the Mediterranean. High-throughput end sequencing of a BAC library yielded 92,468 reads (60.6 Mbp. Comparative mapping was achieved by anchoring BAC end sequences to the three-spined stickleback (Gasterosteus aculeatus genome. BACs that were consistently ordered along the stickleback chromosomes accounted for 14,265 clones. A fraction of 5,249 BACs constituted a minimal tiling path that covers 73.5% of the stickleback chromosomes and 70.2% of the genes that have been annotated. The N50 size of 1,485 “BACtigs” consisting of redundant BACs is 337,253 bp. The largest BACtig covers 2.15 Mbp in the stickleback genome. According to the insert size distribution of mapped BACs the sea bream genome is 1.71-fold larger than the stickleback genome. These results represent a valuable tool to researchers in the field and may support future projects to elucidate the whole sea bream genome.

Similarities in temperature-dependent gene expression plasticity across timescales in threespine stickleback (Gasterosteus aculeatus).

Science.gov (United States)

Metzger, David C H; Schulte, Patricia M

2018-04-14

Phenotypic plasticity occurs at a variety of timescales, but little is known about the degree to which plastic responses at different timescales are associated with similar underlying molecular processes, which is critical for assessing the effects of plasticity on evolutionary trajectories. To address this issue, we identified differential gene expression in response to developmental temperature in the muscle transcriptome of adult threespine stickleback (Gasterosteus aculeatus) exposed to 12, 18 and 24°C until hatch and then held at 18°C for 9 months and compared these results to differential gene expression in response to adult thermal acclimation in stickleback developed at 18°C and then acclimated to 5 and 25°C as adults. Adult thermal acclimation affected the expression of 7,940 and 7,015 genes in response to cold and warm acclimation, respectively, and 4,851 of these genes responded in both treatments. In contrast, the expression of only 33 and 29 genes was affected by cold and warm development, respectively. The majority of the genes affected by developmental temperature were also affected by adult acclimation temperature. Many genes that were differentially expressed as a result of adult acclimation were associated with previously identified temperature-dependent effects on DNA methylation patterns, suggesting a role of epigenetic mechanisms in regulating gene expression plasticity during acclimation. Taken together, these results demonstrate similarities between the persistent effects of developmental plasticity on gene expression and the effects of adult thermal acclimation, emphasizing the potential for mechanistic links between plasticity acting at these different life stages. © 2018 John Wiley & Sons Ltd.

New records of Ergasilus (Copepoda: Ergasilidae) in the Laurentian Great Lakes, including a lakewide review of records and host associations

Science.gov (United States)

Hudson, Patrick L.; Bowen, Charles A.; Stedman, Ralph M.

1994-01-01

Ergasilus nerkae was found infecting ninespine stickleback (Pungitius pungitius) in lakes Huron, Michigan, and Superior and threespine stickleback (Gasterosteus aculeatus) and round whitefish (Prosopium cylindraceum) in Lake Huron. Based upon the literature and study of archived material, we propose that E. nerkae is enzootic to the Great Lakes and that ninespine stickleback are a preferred host in Lake Huron. Prevalence of E. nerkae on ninespine stickleback increased from 17% in June to 68% in September, but mean intensity remained light. Prevalence and mean intensity increased with host length. Ergasilus luciopercarum is also reported on lake trout (Salvelinus namaycush) and largemouth bass (Micropterus salmoides) for the first time. Host-parasite records of Ergasilus spp. in North America are reviewed, biology and taxonomy are summarized, and a checklist of Great Lakes host-parasite-locality records is provided. At present, eight species of Ergasilus are known to infect 42 Great Lakes fish species.

Natural selection on MHC IIβ in parapatric lake and stream stickleback: Balancing, divergent, both or neither?

Science.gov (United States)

Stutz, William E; Bolnick, Daniel I

2017-09-01

Major histocompatibility complex (MHC) genes encode proteins that play a central role in vertebrates' adaptive immunity to parasites. MHC loci are among the most polymorphic in vertebrates' genomes, inspiring many studies to identify evolutionary processes driving MHC polymorphism within populations and divergence between populations. Leading hypotheses include balancing selection favouring rare alleles within populations, and spatially divergent selection. These hypotheses do not always produce diagnosably distinct predictions, causing many studies of MHC to yield inconsistent or ambiguous results. We suggest a novel strategy to distinguish balancing vs. divergent selection on MHC, taking advantage of natural admixture between parapatric populations. With divergent selection, individuals with immigrant alleles will be more infected and less fit because they are susceptible to novel parasites in their new habitat. With balancing selection, individuals with locally rare immigrant alleles will be more fit (less infected). We tested these contrasting predictions using three-spine stickleback from three replicate pairs of parapatric lake and stream habitats. We found numerous positive and negative associations between particular MHC IIβ alleles and particular parasite taxa. A few allele-parasite comparisons supported balancing selection, and others supported divergent selection between habitats. But, there was no overall tendency for fish with immigrant MHC alleles to be more or less heavily infected. Instead, locally rare MHC alleles (not necessarily immigrants) were associated with heavier infections. Our results illustrate the complex relationship between MHC IIβ allelic variation and spatially varying multispecies parasite communities: different hypotheses may be concurrently true for different allele-parasite combinations. © 2017 John Wiley & Sons Ltd.

Effects of VIE tagging and partial tissue sampling on the immune response of three-spined stickleback Gasterosteus aculeatus.

Science.gov (United States)

Henrich, T; Hafer, N; Mobley, K B

2014-09-01

A 14 day experiment on effects of visible implant elastomer (VIE) tagging and spine-clipping of three-spined stickleback Gasterosteus aculeatus showed significant increases in immune response, particularly in the granulocyte:lymphocyte ratio, in both treatments and the sham control. A minimum two-week recovery after handling, anaesthesia, tagging and spine-clipping is recommended to minimize effect of manipulation on the immune system. © 2014 The Fisheries Society of the British Isles.

CYP1A inhibition in fish gill filaments: A novel assay applied on pharmaceuticals and other chemicals

Energy Technology Data Exchange (ETDEWEB)

Beijer, Kristina; Abrahamson, Alexandra; Brunstroem, Bjoern [Department of Environmental Toxicology, Uppsala University, Norbyvaegen 18A, SE-752 36 Uppsala (Sweden); Brandt, Ingvar, E-mail: ingvar.brandt@ebc.uu.se [Department of Environmental Toxicology, Uppsala University, Norbyvaegen 18A, SE-752 36 Uppsala (Sweden)

2010-01-31

The gill filament 7-ethoxyresorufin O-deethylase (EROD) assay was originally developed as a biomarker for cytochrome P4501A (CYP1A) induction by Ah-receptor agonists in water. In this study, the assay was adapted to measure inhibition of CYP1A activity in fish gill filaments ex vivo. The experiments were carried out using gill arch filaments from {beta}-naphthoflavone ({beta}NF)-exposed three-spined stickleback (Gasterosteus aculeatus). Candidate CYP1A inhibitors were added to the assay buffer. Nine selected pharmaceuticals and five known or suspected CYP1A-modulating chemicals were examined with regard to their ability to reduce EROD activity in gill filaments. Ellipticine, a well characterized CYP1A inhibitor, was the most effective inhibitor of the compounds tested. At a concentration in the assay buffer of 1 {mu}M the antifungal azoles ketoconazole, miconazole and bitertanol, and the plant flavonoid acacetin reduced gill EROD activity by more than 50%, implying IC50 values below 1 {mu}M. These compounds have previously been shown to inhibit EROD activity in liver microsomes from fish and mammals at similar concentrations. The proton pump inhibitor omeprazole reduced the gill EROD activity by 39% at 10 {mu}M. It is concluded that the modified gill filament EROD assay is useful to screen for waterborne pollutants that inhibit catalytic CYP1A activity in fish gills.

CYP1A inhibition in fish gill filaments: A novel assay applied on pharmaceuticals and other chemicals

International Nuclear Information System (INIS)

Beijer, Kristina; Abrahamson, Alexandra; Brunstroem, Bjoern; Brandt, Ingvar

2010-01-01

The gill filament 7-ethoxyresorufin O-deethylase (EROD) assay was originally developed as a biomarker for cytochrome P4501A (CYP1A) induction by Ah-receptor agonists in water. In this study, the assay was adapted to measure inhibition of CYP1A activity in fish gill filaments ex vivo. The experiments were carried out using gill arch filaments from β-naphthoflavone (βNF)-exposed three-spined stickleback (Gasterosteus aculeatus). Candidate CYP1A inhibitors were added to the assay buffer. Nine selected pharmaceuticals and five known or suspected CYP1A-modulating chemicals were examined with regard to their ability to reduce EROD activity in gill filaments. Ellipticine, a well characterized CYP1A inhibitor, was the most effective inhibitor of the compounds tested. At a concentration in the assay buffer of 1 μM the antifungal azoles ketoconazole, miconazole and bitertanol, and the plant flavonoid acacetin reduced gill EROD activity by more than 50%, implying IC50 values below 1 μM. These compounds have previously been shown to inhibit EROD activity in liver microsomes from fish and mammals at similar concentrations. The proton pump inhibitor omeprazole reduced the gill EROD activity by 39% at 10 μM. It is concluded that the modified gill filament EROD assay is useful to screen for waterborne pollutants that inhibit catalytic CYP1A activity in fish gills.

Population structure and effective/census population size ratio in threatened three-spined stickleback populations from an isolated river basin in northwest Spain.

Science.gov (United States)

Pérez-Figueroa, A; Fernández, C; Amaro, R; Hermida, M; San Miguel, E

2015-08-01

Variability at 20 microsatellite loci was examined to assess the population genetic structure, gene flow, and effective population size (N(e)) in three populations of three-spined stickleback (Gasterosteus aculeatus) from the upper basin of the Miño River in Galicia, NW Spain, where this species is threatened. The three populations showed similar levels of genetic diversity. There is a significant genetic differentiation between the three populations, but also significant gene flow. N(e) estimates based on linkage disequilibrium yielded values of 355 for the Miño River population and 241 and 311 for the Rato and Guisande Rivers, respectively, although we expect that these are overestimates. N(e) estimates based on temporal methods, considering gene flow or not, for the tributaries yielded values of 30-56 and 47-56 for the Rato and Guisande Rivers, respectively. Estimated census size (N(c)) for the Rato River was 880 individuals. This yielded a N(e)/N(c) estimate of 3-6 % for temporal estimation of N(e), which is within the empirical range observed in freshwater fishes. We suggest that the three populations analyzed have a sufficient level of genetic diversity with some genetic structure. Additionally, the absence of physical barriers suggests that conservation efforts and monitoring should focus in the whole basin as a unit.

Male choice in the stream-anadromous stickleback complex.

Directory of Open Access Journals (Sweden)

Jeffrey S McKinnon

Full Text Available Studies of mating preferences and pre-mating reproductive isolation have often focused on females, but the potential importance of male preferences is increasingly appreciated. We investigated male behavior in the context of reproductive isolation between divergent anadromous and stream-resident populations of threespine stickleback, Gasterosteus aculeatus, using size-manipulated females of both ecotypes. Specifically, we asked if male courtship preferences are present, and if they are based on relative body size, non-size aspects of ecotype, or other traits. Because male behaviors were correlated with each other, we conducted a principal components analysis on the correlations and ran subsequent analyses on the principal components. The two male ecotypes differed in overall behavioral frequencies, with stream-resident males exhibiting consistently more vigorous and positive courtship than anadromous males, and an otherwise aggressive behavior playing a more positive role in anadromous than stream-resident courtship. We observed more vigorous courtship toward smaller females by (relatively small stream-resident males and the reverse pattern for (relatively large anadromous males. Thus size-assortative male courtship preferences may contribute to reproductive isolation in this system, although preferences are far from absolute. We found little indication of males responding preferentially to females of their own ecotype independent of body size.

Fast evolution from precast bricks: genomics of young freshwater populations of threespine stickleback Gasterosteus aculeatus.

Directory of Open Access Journals (Sweden)

Nadezhda V Terekhanova

2014-10-01

Full Text Available Adaptation is driven by natural selection; however, many adaptations are caused by weak selection acting over large timescales, complicating its study. Therefore, it is rarely possible to study selection comprehensively in natural environments. The threespine stickleback (Gasterosteus aculeatus is a well-studied model organism with a short generation time, small genome size, and many genetic and genomic tools available. Within this originally marine species, populations have recurrently adapted to freshwater all over its range. This evolution involved extensive parallelism: pre-existing alleles that adapt sticklebacks to freshwater habitats, but are also present at low frequencies in marine populations, have been recruited repeatedly. While a number of genomic regions responsible for this adaptation have been identified, the details of selection remain poorly understood. Using whole-genome resequencing, we compare pooled genomic samples from marine and freshwater populations of the White Sea basin, and identify 19 short genomic regions that are highly divergent between them, including three known inversions. 17 of these regions overlap protein-coding genes, including a number of genes with predicted functions that are relevant for adaptation to the freshwater environment. We then analyze four additional independently derived young freshwater populations of known ages, two natural and two artificially established, and use the observed shifts of allelic frequencies to estimate the strength of positive selection. Adaptation turns out to be quite rapid, indicating strong selection acting simultaneously at multiple regions of the genome, with selection coefficients of up to 0.27. High divergence between marine and freshwater genotypes, lack of reduction in polymorphism in regions responsible for adaptation, and high frequencies of freshwater alleles observed even in young freshwater populations are all consistent with rapid assembly of G. aculeatus

Fast evolution from precast bricks: genomics of young freshwater populations of threespine stickleback Gasterosteus aculeatus.

Science.gov (United States)

Terekhanova, Nadezhda V; Logacheva, Maria D; Penin, Aleksey A; Neretina, Tatiana V; Barmintseva, Anna E; Bazykin, Georgii A; Kondrashov, Alexey S; Mugue, Nikolai S

2014-10-01

Adaptation is driven by natural selection; however, many adaptations are caused by weak selection acting over large timescales, complicating its study. Therefore, it is rarely possible to study selection comprehensively in natural environments. The threespine stickleback (Gasterosteus aculeatus) is a well-studied model organism with a short generation time, small genome size, and many genetic and genomic tools available. Within this originally marine species, populations have recurrently adapted to freshwater all over its range. This evolution involved extensive parallelism: pre-existing alleles that adapt sticklebacks to freshwater habitats, but are also present at low frequencies in marine populations, have been recruited repeatedly. While a number of genomic regions responsible for this adaptation have been identified, the details of selection remain poorly understood. Using whole-genome resequencing, we compare pooled genomic samples from marine and freshwater populations of the White Sea basin, and identify 19 short genomic regions that are highly divergent between them, including three known inversions. 17 of these regions overlap protein-coding genes, including a number of genes with predicted functions that are relevant for adaptation to the freshwater environment. We then analyze four additional independently derived young freshwater populations of known ages, two natural and two artificially established, and use the observed shifts of allelic frequencies to estimate the strength of positive selection. Adaptation turns out to be quite rapid, indicating strong selection acting simultaneously at multiple regions of the genome, with selection coefficients of up to 0.27. High divergence between marine and freshwater genotypes, lack of reduction in polymorphism in regions responsible for adaptation, and high frequencies of freshwater alleles observed even in young freshwater populations are all consistent with rapid assembly of G. aculeatus freshwater genotypes

Relation between the electrolytic solution pressures of the metals and their toxicity to the stickleback (Gasterosteus acelueatus l. )

Energy Technology Data Exchange (ETDEWEB)

Jones, J R.E.

1939-01-01

Lethal concentration limits have been determined for the hydrogen ion and the ions of eighteen metals. The three-spined stickleback (Gasterosteus aculeatus l.) has been employed as test animal. According to their lethal concentration limits on a mg./l. basis their order of increasing toxicity is: Sr, Ca, Na, Ba, Mg, K, Mn, Co, Cr, Ni, Au, Zn, Cd, Pb, Al, Cu, H, Hg, and Ag. On a molar concentration basis the order is as follows: Na, Ca, Sr, Mg, Ba, K, Mn, Co, Cr, Ni, H, Zn, Al, Au, Cd, Pb, Cu, Hg, Ag. All these ions, with the exception of the first six (the metals of the alkalis and alkaline earths), bring about the death of fish by precipitating the gill secretions, thus causing asphyxiation. The alkali and alkaline earth metals appear to enter the body and act as true internal poisons. The position of iron is uncertain. The toxicity of solutions of iron salts appears to be due, mainly if not entirely, to their acidity. On a mg./l. or molar concentration basis there is a marked relationship between the toxicity of the metals and their solution pressures. The metals of very low solution pressure (Ag, Cu, etc.), i.e. those whose ions are most ready to part with their charges and enter into combination with other ions or compounds, are the most toxic as they precipitate the gill secretions and bring about asphyxiation with extreme rapidity. Metals of somewhat higher solution pressure (Zn, Pb, Cd) act in the same way but more slowly. Manganese, which of all the heavy metals has the highest solution pressure, takes effect very slowly and the ions of the alkali and alkaline earth metals, which have a high affinity for their charges, do not precipitate the gill secretions at all. In the case of all ions other than those of the alkali and alkaline earth metals the reactions responsible for the death of the fish take place outside the body. Thus their speed of action does not depend on their penetrating power and the permeability factor does not enter.

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

Science.gov (United States)

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.

A synthesis of ecological and fish-community changes in Lake Ontario, 1970-2000

Science.gov (United States)

Mills, E.L.; Casselman, J.M.; Dermott, R.; Fitzsimons, J.D.; Gal, G.; Holeck, K. T.; Hoyle, J.A.; Johannsson, O.E.; Lantry, B.F.; Makarewicz, J.C.; Millard, E.S.; Munawar, I.F.; Munawar, M.; O'Gorman, R.; Owens, R.W.; Rudstam, L. G.; Schaner, T.; Stewart, T.J.

2005-01-01

We assessed stressors associated with ecological and fishcommunity changes in Lake Ontario since 1970, when the first symposium on Salmonid Communities in Oligotrophic Lakes (SCOL I) was held (J. Fish. Res. Board Can. 29: 613-616). Phosphorus controls implemented in the early 1970s were undeniably successful; lower food-web studies showed declines in algal abundance and epilimnetic zooplankton production and a shift in pelagic primary productivity toward smaller organisms. Stressors on the fish community prior to 1970 such as exploitation, sea lamprey (Petromyzon marinus) predation, and effects of nuisance populations of alewife (Alosa pseudoharengus) were largely ameliorated by the 1990s. The alewife became a pivotal species supporting a multi-million-dollar salmonid sport fishery, but alewife-induced thiamine deficiency continued to hamper restoration and sustainability of native lake trout (Salvelinus namaycush). Expanding salmonine populations dependent on alewife raised concerns about predator demand and prey supply, leading to reductions in salmonine stocking in the early 1990s. Relaxation of the predation impact by alewives and their shift to deeper water allowed recovery of native fishes such as threespine stickleback (Gasterosteus aculeatus) and emerald shiner (Notropis atherinoides). The return of the Lake Ontario ecosystem to historical conditions has been impeded by unplanned introductions. Establishment of Dreissena spp. led to increased water clarity and increased vectoring of lower trophic-level production to benthic habitats and contributed to the collapse of Diporeia spp. populations, behavioral modifications of key fish species, and the decline of native lake whitefish (Coregonus clupeaformis). Despite reduced productivity, exotic-species introductions, and changes in the fish community, offshore Mysis relicta populations remained relatively stable. The effects of climate and climate change on the population abundance and dynamics of Lake Ontario

Extensive behavioural divergence following colonisation of the freshwater environment in threespine sticklebacks.

Directory of Open Access Journals (Sweden)

Carole Di-Poi

Full Text Available Colonisation of novel environments means facing new ecological challenges often resulting in the evolution of striking divergence in phenotypes. However, little is known about behavioural divergence following colonisation, despite the predicted importance of the role of behavioural phenotype-environment associations in adaptive divergence. We studied the threespine stickleback (Gasterosteus aculeatus, a model system for postglacial colonisation of freshwater habitats largely differing in ecological conditions from the ones faced by the descendants of the marine ancestor. We found that common-environment reared freshwater juveniles were less social, more active and more aggressive than their marine counterparts. This behavioural divergence could represent the result of natural selection that acted on individuals following freshwater colonisation, with predation as a key selection agent. Alternatively, the behavioural profile of freshwater juveniles could represent the characteristics of individuals that preferentially invaded freshwater after the glacial retreat, drawn from the standing variation present in the marine population.

The contribution of post-copulatory mechanisms to incipient ecological speciation in sticklebacks.

Science.gov (United States)

Kaufmann, Joshka; Eizaguirre, Christophe; Milinski, Manfred; Lenz, Tobias L

2015-01-01

Ecology can play a major role in species diversification. As individuals are adapting to contrasting habitats, reproductive barriers may evolve at multiple levels. While pre-mating barriers have been extensively studied, the evolution of post-mating reproductive isolation during early stages of ecological speciation remains poorly understood. In diverging three-spined stickleback ecotypes from two lakes and two rivers, we observed differences in sperm traits between lake and river males. Interestingly, these differences did not translate into ecotype-specific gamete precedence for sympatric males in competitive in vitro fertilization experiments, potentially owing to antagonistic compensatory effects. However, we observed indirect evidence for impeded development of inter-ecotype zygotes, possibly suggesting an early stage of genetic incompatibility between ecotypes. Our results show that pre-zygotic post-copulatory mechanisms play a minor role during this first stage of ecotype divergence, but suggest that genetic incompatibilities may arise at early stages of ecological speciation. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

Genetic Architecture of Conspicuous Red Ornaments in Female Threespine Stickleback

Directory of Open Access Journals (Sweden)

Lengxob Yong

2016-03-01

Full Text Available Explaining the presence of conspicuous female ornaments that take the form of male-typical traits has been a longstanding challenge in evolutionary biology. Such female ornaments have been proposed to evolve via both adaptive and nonadaptive evolutionary processes. Determining the genetic underpinnings of female ornaments is important for elucidating the mechanisms by which such female traits arise and persist in natural populations, but detailed information about their genetic basis is still scarce. In this study, we investigated the genetic architecture of two ornaments, the orange-red throat and pelvic spine, in the threespine stickleback (Gasterosteus aculeatus. Throat coloration is male-specific in ancestral marine populations but has evolved in females in some derived stream populations, whereas sexual dimorphism in pelvic spine coloration is variable among populations. We find that ornaments share a common genetic architecture between the sexes. At least three independent genomic regions contribute to red throat coloration, and harbor candidate genes related to pigment production and pigment cell differentiation. One of these regions is also associated with spine coloration, indicating that both ornaments might be mediated partly via pleiotropic genetic mechanisms.

The genetic architecture of parallel armor plate reduction in threespine sticklebacks.

Directory of Open Access Journals (Sweden)

Pamela F Colosimo

2004-05-01

Full Text Available How many genetic changes control the evolution of new traits in natural populations? Are the same genetic changes seen in cases of parallel evolution? Despite long-standing interest in these questions, they have been difficult to address, particularly in vertebrates. We have analyzed the genetic basis of natural variation in three different aspects of the skeletal armor of threespine sticklebacks (Gasterosteus aculeatus: the pattern, number, and size of the bony lateral plates. A few chromosomal regions can account for variation in all three aspects of the lateral plates, with one major locus contributing to most of the variation in lateral plate pattern and number. Genetic mapping and allelic complementation experiments show that the same major locus is responsible for the parallel evolution of armor plate reduction in two widely separated populations. These results suggest that a small number of genetic changes can produce major skeletal alterations in natural populations and that the same major locus is used repeatedly when similar traits evolve in different locations.

New parasites and predators follow the introduction of two fish species to a subarctic lake: implications for food-web structure and functioning

Science.gov (United States)

Amundsen, Per-Arne; Lafferty, Kevin D.; Knudsen, Rune; Primicerio, Raul; Kristoffersen, Roar; Klemetsen, Anders; Kuris, Armand M.

2012-01-01

Introduced species can alter the topology of food webs. For instance, an introduction can aid the arrival of free-living consumers using the new species as a resource, while new parasites may also arrive with the introduced species. Food-web responses to species additions can thus be far more complex than anticipated. In a subarctic pelagic food web with free-living and parasitic species, two fish species (arctic charr Salvelinus alpinus and three-spined stickleback Gasterosteus aculeatus) have known histories as deliberate introductions. The effects of these introductions on the food web were explored by comparing the current pelagic web with a heuristic reconstruction of the pre-introduction web. Extinctions caused by these introductions could not be evaluated by this approach. The introduced fish species have become important hubs in the trophic network, interacting with numerous parasites, predators and prey. In particular, five parasite species and four predatory bird species depend on the two introduced species as obligate trophic resources in the pelagic web and could therefore not have been present in the pre-introduction network. The presence of the two introduced fish species and the arrival of their associated parasites and predators increased biodiversity, mean trophic level, linkage density, and nestedness; altering both the network structure and functioning of the pelagic web. Parasites, in particular trophically transmitted species, had a prominent role in the network alterations that followed the introductions.

The Relationship between the Ionic Composition of the Environment and the Secretory Activity of the Endocrine Cell Types of Stannius Corpuscles in the Teleost Gasterosteus aculeatus

NARCIS (Netherlands)

Wendelaar Bonga, S.E.; Greven, J.A.A.; Veenhuis, M.

1976-01-01

The corpuscles of Stannius of threespined sticklebacks contain two glandular cell types of presumed endocrine nature. To elucidate the function of both cell types the secretory activity of the cells was studied in fully adapted seawater and freshwater fishes and in specimens transferred from sea

78 FR 37176 - Addition of Nonylphenol Category; Community Right-to-Know Toxic Chemical Release Reporting

Science.gov (United States)

2013-06-20

... species of marine animals; the blue mussel (Mytilus edulis), the three-spined stickleback fish...., A. Bergman, A. Granmo, and M. Berggren. 1990. Bioaccumulation of 4-nonylphenol in marine animals--A... previously peer reviewed (Ref. 3). A. Acute Toxicity to Aquatic Animals 1. Freshwater Species. The acute...

Investment in boney defensive traits alters organismal stoichiometry and excretion in fish.

Science.gov (United States)

El-Sabaawi, Rana W; Warbanski, Misha L; Rudman, Seth M; Hovel, Rachel; Matthews, Blake

2016-08-01

Understanding how trait diversification alters ecosystem processes is an important goal for ecological and evolutionary studies. Ecological stoichiometry provides a framework for predicting how traits affect ecosystem function. The growth rate hypothesis of ecological stoichiometry links growth and phosphorus (P) body composition in taxa where nucleic acids are a significant pool of body P. In vertebrates, however, most of the P is bound within bone, and organisms with boney structures can vary in terms of the relative contributions of bones to body composition. Threespine stickleback populations have substantial variation in boney armour plating. Shaped by natural selection, this variation provides a model system to study the links between evolution of bone content, elemental body composition, and P excretion. We measure carbon:nitrogen:P body composition from stickleback populations that vary in armour phenotype. We develop a mechanistic mass-balance model to explore factors affecting P excretion, and measure P excretion from two populations with contrasting armour phenotypes. Completely armoured morphs have higher body %P but excrete more P per unit body mass than other morphs. The model suggests that such differences are driven by phenotypic differences in P intake as well as body %P composition. Our results show that while investment in boney traits alters the elemental composition of vertebrate bodies, excretion rates depend on how acquisition and assimilation traits covary with boney trait investment. These results also provide a stoichiometric hypothesis to explain the repeated loss of boney armour in threespine sticklebacks upon colonizing freshwater ecosystems.

Individual diet has sex-dependent effects on vertebrate gut microbiota

Science.gov (United States)

Bolnick, Daniel I.; Snowberg, Lisa K.; Hirsch, Philipp E.; Lauber, Christian L.; Org, Elin; Parks, Brian; Lusis, Aldons J.; Knight, Rob; Caporaso, J. Gregory; Svanbäck, Richard

2014-01-01

Vertebrates harbour diverse communities of symbiotic gut microbes. Host diet is known to alter microbiota composition, implying that dietary treatments might alleviate diseases arising from altered microbial composition (‘dysbiosis’). However, it remains unclear whether diet effects are general or depend on host genotype. Here we show that gut microbiota composition depends on interactions between host diet and sex within populations of wild and laboratory fish, laboratory mice and humans. Within each of two natural fish populations (threespine stickleback and Eurasian perch), among-individual diet variation is correlated with individual differences in gut microbiota. However, these diet–microbiota associations are sex dependent. We document similar sex-specific diet–microbiota correlations in humans. Experimental diet manipulations in laboratory stickleback and mice confirmed that diet affects microbiota differently in males versus females. The prevalence of such genotype by environment (sex by diet) interactions implies that therapies to treat dysbiosis might have sex-specific effects. PMID:25072318

Insights into the Social Behavior of Surface and Cave-Dwelling Fish (Poecilia mexicana in Light and Darkness through the Use of a Biomimetic Robot

Directory of Open Access Journals (Sweden)

David Bierbach

2018-02-01

Full Text Available Biomimetic robots (BRs are becoming more common in behavioral research and, if they are accepted as conspecifics, allow for new forms of experimental manipulations of social interactions. Nevertheless, it is often not clear which cues emanating from a BR are actually used as communicative signals and how species or populations with different sensory makeups react to specific types of BRs. We herein present results from experiments using two populations of livebearing fishes that differ in their sensory capabilities. In the South of Mexico, surface-dwelling mollies (Poecilia mexicana successfully invaded caves and adapted to dark conditions. While almost without pigment, these cave mollies possess smaller but still functional eyes. Although previous studies found cave mollies to show reduced shoaling preferences with conspecifics in light compared to surface mollies, it is assumed that they possess specialized adaptations to maintain some kind of sociality also in their dark habitats. By testing surface- and cave-dwelling mollies with RoboFish, a BR made for use in laboratory experiments with guppies and sticklebacks, we asked to what extent visual and non-visual cues play a role in their social behavior. Both cave- and surface-dwelling mollies followed the BR as well as a live companion when tested in light. However, when tested in darkness, only surface-dwelling fish were attracted by a live conspecific, whereas cave-dwelling fish were not. Neither cave- nor surface-dwelling mollies were attracted to RoboFish in darkness. This is the first study to use BRs for the investigation of social behavior in mollies and to compare responses to BRs both in light and darkness. As our RoboFish is accepted as conspecific by both used populations of the Atlantic molly only under light conditions but not in darkness, we argue that our replica is providing mostly visual cues.

Maintenance of a genetic polymorphism with disruptive natural selection in stickleback.

Science.gov (United States)

Marchinko, Kerry B; Matthews, Blake; Arnegard, Matthew E; Rogers, Sean M; Schluter, Dolph

2014-06-02

The role of natural selection in the maintenance of genetic variation in wild populations remains a major problem in evolution. The influence of disruptive natural selection on genetic variation is especially interesting because it might lead to the evolution of assortative mating or dominance [1, 2]. In theory, variation can persist at a gene under disruptive natural selection, but the process is little studied and there are few examples [3, 4]. We report a stable polymorphism in the bony armor of threespine stickleback maintained with a deficit of heterozygotes at the major underlying gene, Ectodysplasin (Eda) [5]. The deficit vanishes at the embryo life stage only to re-emerge in adults, indicating that disruptive natural selection, rather than nonrandom mating, is the cause. The mechanism enabling long-term persistence of the polymorphism is unknown, but disruptive selection is predicted to be frequency dependent, favoring homozygous genotypes when they become rare. Further research on the ecological and evolutionary processes affecting individual genes will ultimately lead to a better understanding of the causes of genetic variation in populations. Copyright © 2014 Elsevier Ltd. All rights reserved.

Visible implant elastomer (VIE) tagging and simulated predation risk elicit similar physiological stress responses in three-spined stickleback Gasterosteus aculeatus.

Science.gov (United States)

Fürtbauer, I; King, A J; Heistermann, M

2015-05-01

The effect of visible implant elastomer (VIE) tagging on the immediate physiological stress response was tested in female three-spined stickleback Gasterosteus aculeatus, using non-invasive waterborne cortisol analysis. Post-tagging cortisol levels were significantly higher compared with pretreatment baseline concentrations; however, when comparing post-tagging cortisol levels with cortisol levels after exposure to a simulated aerial predator, no significant differences were found. This study indicates that VIE tagging elicits a physiological stress response similar to those occurring in the everyday lives of this important biological model organism. © 2015 The Fisheries Society of the British Isles.

Directional genetic selection by pulp mill effluent on multiple natural populations of three-spined stickleback (Gasterosteus aculeatus).

Science.gov (United States)

Lind, Emma E; Grahn, Mats

2011-05-01

Contamination can cause a rapid environmental change which may require populations to respond with evolutionary changes. To evaluate the effects of pulp mill effluents on population genetics, we sampled three-spined sticklebacks (Gasterosteus aculeatus) near four pulp mills and four adjacent reference sites and analyzed Amplified Fragment Length Polymorphism (AFLP) to compare genetic variability. A fine scale genetic structure was detected and samples from polluted sites separated from reference sites in multidimensional scaling plots (Pselection. When removing 13 F(ST)-outlier loci, significant at the Pselective agent on natural populations of G. aculeatus, causing a convergence in genotype composition change at multiple sites in an open environment. © The Author(s) 2011. This article is published with open access at Springerlink.com

Genomics of Rapid Incipient Speciation in Sympatric Threespine Stickleback.

Directory of Open Access Journals (Sweden)

David A Marques

2016-02-01

Full Text Available Ecological speciation is the process by which reproductively isolated populations emerge as a consequence of divergent natural or ecologically-mediated sexual selection. Most genomic studies of ecological speciation have investigated allopatric populations, making it difficult to infer reproductive isolation. The few studies on sympatric ecotypes have focused on advanced stages of the speciation process after thousands of generations of divergence. As a consequence, we still do not know what genomic signatures of the early onset of ecological speciation look like. Here, we examined genomic differentiation among migratory lake and resident stream ecotypes of threespine stickleback reproducing in sympatry in one stream, and in parapatry in another stream. Importantly, these ecotypes started diverging less than 150 years ago. We obtained 34,756 SNPs with restriction-site associated DNA sequencing and identified genomic islands of differentiation using a Hidden Markov Model approach. Consistent with incipient ecological speciation, we found significant genomic differentiation between ecotypes both in sympatry and parapatry. Of 19 islands of differentiation resisting gene flow in sympatry, all were also differentiated in parapatry and were thus likely driven by divergent selection among habitats. These islands clustered in quantitative trait loci controlling divergent traits among the ecotypes, many of them concentrated in one region with low to intermediate recombination. Our findings suggest that adaptive genomic differentiation at many genetic loci can arise and persist in sympatry at the very early stage of ecotype divergence, and that the genomic architecture of adaptation may facilitate this.

Reduction of sexual dimorphism in stream-resident forms of three-spined stickleback Gasterosteus aculeatus

Science.gov (United States)

Kitano, J.; Mori, S.; Peichel, C. L.

2013-01-01

Sexual dimorphism in geometric body shape and external morphology was compared between marine and stream-resident forms of three-spined stickleback Gasterosteus aculeatus collected from North America and Japan. Some aspects of sexual dimorphism were shared between ecotypes: males had larger heads than females with no significant effect of ecotype on the magnitude of sexual dimorphism. By contrast, a significant sex-by-ecotype interaction was found for body depth. Males tended to have deeper bodies than females in both forms, but the magnitude of sexual dimorphism was reduced in stream-resident forms. Although females were generally larger in standard length and had larger pelvic girdles, significant sexual dimorphism in these traits was not consistently found across populations or ecotypes. These results suggest that some aspects of sexual dimorphism were shared between ecotypes, while others were unique to each population. The results further suggest that ecology may influence the evolution of sexual dimorphism in some external morphological traits, such as body depth. PMID:22220894

Bet hedging in a warming ocean: predictability of maternal environment shapes offspring size variation in marine sticklebacks.

Science.gov (United States)

Shama, Lisa N S

2015-12-01

Bet hedging at reproduction is expected to evolve when mothers are exposed to unpredictable cues for future environmental conditions, whereas transgenerational plasticity (TGP) should be favoured when cues reliably predict the environment offspring will experience. Since climate predictions forecast an increase in both temperature and climate variability, both TGP and bet hedging are likely to become important strategies to mediate climate change effects. Here, the potential to produce variably sized offspring in both warming and unpredictable environments was tested by investigating whether stickleback (Gasterosteus aculeatus) mothers adjusted mean offspring size and within-clutch variation in offspring size in response to experimental manipulation of maternal thermal environment and predictability (alternating between ambient and elevated water temperatures). Reproductive output traits of F1 females were influenced by both temperature and environmental predictability. Mothers that developed at ambient temperature (17 °C) produced larger, but fewer eggs than mothers that developed at elevated temperature (21 °C), implying selection for different-sized offspring in different environments. Mothers in unpredictable environments had smaller mean egg sizes and tended to have greater within-female egg size variability, especially at 21 °C, suggesting that mothers may have dynamically modified the variance in offspring size to spread the risk of incorrectly predicting future environmental conditions. Both TGP and diversification influenced F2 offspring body size. F2 offspring reared at 21 °C had larger mean body sizes if their mother developed at 21 °C, but this TGP benefit was not present for offspring of 17 °C mothers reared at 17 °C, indicating that maternal TGP will be highly relevant for ocean warming scenarios in this system. Offspring of variable environment mothers were smaller but more variable in size than offspring from constant environment

REINFORCEMENT OF STICKLEBACK MATE PREFERENCES: SYMPATRY BREEDS CONTEMPT.

Science.gov (United States)

Rundle, Howard D; Schluter, Dolph

1998-02-01

Detailed studies of reproductive isolation and how it varies among populations can provide valuable insight into the mechanisms of speciation. Here we investigate how the strength of premating isolation varies between sympatric and allopatric populations of threespine sticklebacks to test a prediction of the hypothesis of reinforcement: that interspecific mate discrimination should be stronger in sympatry than in allopatry. In conducting such tests, it is important to control for ecological character displacement between sympatric species because ecological character divergence may strengthen prezygotic isolation as a by-product. We control for ecological character displacement by comparing mate preferences of females from a sympatric population (benthics) with mate preferences of females from two allopatric populations that most closely resemble the sympatric benthic females in ecology and morphology. No-choice mating trials indicate that sympatric benthic females mate less readily with heterospecific (limnetic) than conspecific (benthic) males, whereas two different populations of allopatric females resembling benthics show no such discrimination. These differences demonstrate reproductive character displacement of benthic female mate choice. Previous studies have established that hybridization between sympatric species occurred in the past in the wild and that hybrid offspring have lower fitness than either parental species, thus providing conditions under which natural selection would favor individuals that do not hybridize. Results are therefore consistent with the hypothesis that female mate preferences have evolved as a response to reduced hybrid fitness (reinforcement), although direct effects of sympatry or a biased extinction process could also produce the pattern. Males of the other sympatric species (limnetics) showed a preference for smaller females, in contrast to the inferred ancestral preference for larger females, suggesting reproductive character

Impact of thermal stress on evolutionary trajectories of pathogen resistance in three-spined stickleback (Gasterosteus aculeatus).

Science.gov (United States)

Schade, Franziska M; Shama, Lisa N S; Wegner, K Mathias

2014-07-26

Pathogens are a major regulatory force for host populations, especially under stressful conditions. Elevated temperatures may enhance the development of pathogens, increase the number of transmission stages, and can negatively influence host susceptibility depending on host thermal tolerance. As a net result, this can lead to a higher prevalence of epidemics during summer months. These conditions also apply to marine ecosystems, where possible ecological impacts and the population-specific potential for evolutionary responses to changing environments and increasing disease prevalence are, however, less known. Therefore, we investigated the influence of thermal stress on the evolutionary trajectories of disease resistance in three marine populations of three-spined sticklebacks Gasterosteus aculeatus by combining the effects of elevated temperature and infection with a bacterial strain of Vibrio sp. using a common garden experiment. We found that thermal stress had an impact on fish weight and especially on survival after infection after only short periods of thermal acclimation. Environmental stress reduced genetic differentiation (QST) between populations by releasing cryptic within-population variation. While life history traits displayed positive genetic correlations across environments with relatively weak genotype by environment interactions (GxE), environmental stress led to negative genetic correlations across environments in pathogen resistance. This reversal of genetic effects governing resistance is probably attributable to changing environment-dependent virulence mechanisms of the pathogen interacting differently with host genotypes, i.e. GPathogenxGHostxE or (GPathogenxE)x(GHostxE) interactions, rather than to pure host genetic effects, i.e. GHostxE interactions. To cope with climatic changes and the associated increase in pathogen virulence, host species require wide thermal tolerances and pathogen-resistant genotypes. The higher resistance we found

Ephemeral stream reaches preserve the evolutionary and distributional history of threespine stickleback in the Santa Clara and Ventura River watersheds of southern California

Science.gov (United States)

Richmond, Jonathan Q.; Jacobs, David K.; Backlin, Adam R.; Swift, Camm C.; Dellith, Chris; Fisher, Robert N.

2015-01-01

Much remains to be understood about the evolutionary history and contemporary landscape genetics of unarmored threespine stickleback in southern California, where populations collectively referred to as Gasterosteus aculeatus williamsoni have severely declined over the past 70+ years and are now endangered. We used mitochondrial sequence and microsatellite data to assess the population genetics and phylogeography of unarmored populations sampled immediately downstream from the type locality of G. a. williamsoni in the upper Santa Clara River, and assessed their distinctiveness with respect to low-armor populations in the downstream sections of the river and the adjacent Ventura River. We also characterized the geographic limits of different plate morphs and evaluated the congruence of those boundaries with barriers to dispersal in both river systems and to neutral genetic variation. We show substantial population structuring within the upper reach of the Santa Clara River, but little partitioning between the lower Santa Clara and Ventura Rivers—we attribute these patterns to different ancestry between spatially subdivided populations within the same drainage, a predominance of downstream gene flow, and ability for coastal dispersal between the Santa Clara and Ventura Rivers. We also show that alleles from introduced low-plate stock have infiltrated a native population in at least one upper Santa Clara River tributary, causing this formerly unarmored population to become gradually low-plated over a 30 + year time period. Measures of genetic diversity, census surveys, and severe habitat disturbance all indicate that unarmored stickleback near the type locality are currently at high risk of extinction.

Heritability of asymmetry and lateral plate number in the threespine stickleback.

Directory of Open Access Journals (Sweden)

John Loehr

Full Text Available The estimation of individual fitness and quality are important elements of evolutionary ecological research. Over the past six decades, there has been great interest in using fluctuating asymmetry (FA to represent individual quality, yet, serious technical problems have hampered efforts to estimate the heritability of FA, which, in turn, has limited progress in the investigation of FA from an evolutionary perspective. Here we estimate the heritability of number of lateral plates, their FA and directional asymmetry (DA in threespine stickleback, Gasterosteus aculeatus. By (i using a meristic trait and (ii basing our calculations on a large half-sib design experiment involving 2,079 offspring from 84 families, we overcame many of the difficulties faced by earlier FA studies. Both lateral plate number and FA in lateral plates were heritable (h(2 = 0.46 and 0.21, respectively, even after controlling for marker genotypes linked to EDA (the major locus influencing plate number. Likewise, DA in lateral plates was heritable h(2 = 0.23. The additive genetic component of FA in lateral plates makes it a prime candidate for further investigation into the evolutionary implications of FA and the genetic underpinnings of developmental instability. This discovery in an evolutionary model species holds the possibility to invigorate the study of FA from an evolutionary perspective.

Environmental change disrupts communication and sexual selection in a stickleback population.

Science.gov (United States)

Candolin, Ulrika; Tukiainen, Iina; Bertell, Elina

2016-04-01

Environmental change that disrupts communication during mate choice and alters sexual selection could influence population dynamics. Yet little is known about such long-term effects. We investigated experimentally the consequences that disrupted visual communication during mate choice has for the quantity and viability of offspring produced in a threespine stickleback population (Gasterosteus aculeatus). We further related the results to long-term monitoring of population dynamics in the field to determine if changes are apparent under natural conditions. The results show that impaired visual communication because of algal blooms reduces reliability of male visual signals as indicators of offspring survival during their first weeks of life. This relaxes sexual selection but has no effect on the number of offspring hatching, as most males have a high hatching success in turbid water. Despite eutrophication and high turbidity levels that interfere with communication during mate choice, the population has grown during recent decades. Large numbers of offspring hatching, combined with high variation in juvenile fitness, has probably shifted selection to later life history stages and maintained a viable population. Together with reduced cost of sexual selection and ongoing ecosystem changes caused by human activities, this could have promoted population growth. These results point to the complexity of ecosystems and the necessity to consider all influencing factors when attempting to understand impacts of human activities on populations.

Sexual imprinting on ecologically divergent traits leads to sexual isolation in sticklebacks.

Science.gov (United States)

Kozak, Genevieve M; Head, Megan L; Boughman, Janette W

2011-09-07

During sexual imprinting, offspring learn parental phenotypes and then select mates who are similar to their parents. Imprinting has been thought to contribute to the process of speciation in only a few rare cases; this is despite imprinting's potential to generate assortative mating and solve the problem of recombination in ecological speciation. If offspring imprint on parental traits under divergent selection, these traits will then be involved in both adaptation and mate preference. Such 'magic traits' easily generate sexual isolation and facilitate speciation. In this study, we show that imprinting occurs in two ecologically divergent stickleback species (benthics and limnetics: Gasterosteus spp.). Cross-fostered females preferred mates of their foster father's species. Furthermore, imprinting is essential for sexual isolation between species; isolation was reduced when females were raised without fathers. Daughters imprinted on father odour and colour during a critical period early in development. These traits have diverged between the species owing to differences in ecology. Therefore, we provide the first evidence that imprinting links ecological adaptation to sexual isolation between species. Our results suggest that imprinting may facilitate the evolution of sexual isolation during ecological speciation, may be especially important in cases of rapid diversification, and thus play an integral role in the generation of biodiversity.

Paternal care in a fish: epigenetics and fitness enhancing effects on offspring anxiety.

Science.gov (United States)

McGhee, Katie E; Bell, Alison M

2014-11-07

In many animals, including humans, interactions with caring parents can have long-lasting effects on offspring sensitivity to stressors. However, whether these parental effects impact offspring fitness in nature is often unclear. In addition, despite evidence that maternal care can influence offspring behaviour via epigenetic alterations to the genome, it remains unclear whether paternal care has similar effects. Here, we show in three-spined sticklebacks, a fish in which fathers are the sole provider of offspring care, that the direct care provided by fathers affects offspring anxiety and the potential for epigenetic alterations to the offspring genome. We find that families are differentially vulnerable to early stress and fathers can compensate for this differential sensitivity with the quality of their care. This variation in paternal care is also linked to the expression in offspring brains of a DNA methyltransferase (Dnmt3a) responsible for de novo methylation. We show that these paternal effects are potentially adaptive and anxious offspring are unlikely to survive an encounter with a predator. By supplying offspring care, fathers reduce offspring anxiety thereby increasing the survival of their offspring-not in the traditional sense through resource provisioning but through an epigenetic effect on offspring behavioural development. © 2014 The Author(s) Published by the Royal Society. All rights reserved.

Grandparental effects in marine sticklebacks: transgenerational plasticity across multiple generations.

Science.gov (United States)

Shama, L N S; Wegner, K M

2014-11-01

Nongenetic inheritance mechanisms such as transgenerational plasticity (TGP) can buffer populations against rapid environmental change such as ocean warming. Yet, little is known about how long these effects persist and whether they are cumulative over generations. Here, we tested for adaptive TGP in response to simulated ocean warming across parental and grandparental generations of marine sticklebacks. Grandparents were acclimated for two months during reproductive conditioning, whereas parents experienced developmental acclimation, allowing us to compare the fitness consequences of short-term vs. prolonged exposure to elevated temperature across multiple generations. We found that reproductive output of F1 adults was primarily determined by maternal developmental temperature, but carry-over effects from grandparental acclimation environments resulted in cumulative negative effects of elevated temperature on hatching success. In very early stages of growth, F2 offspring reached larger sizes in their respective paternal and grandparental environment down the paternal line, suggesting that other factors than just the paternal genome may be transferred between generations. In later growth stages, maternal and maternal granddam environments strongly influenced offspring body size, but in opposing directions, indicating that the mechanism(s) underlying the transfer of environmental information may have differed between acute and developmental acclimation experienced by the two generations. Taken together, our results suggest that the fitness consequences of parental and grandparental TGP are highly context dependent, but will play an important role in mediating some of the impacts of rapid climate change in this system. © 2014 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2014 European Society For Evolutionary Biology.

Sexual dimorphism of head morphology in three-spined stickleback Gasterosteus aculeatus.

Science.gov (United States)

Aguirre, W E; Akinpelu, O

2010-09-01

This study examined sexual dimorphism of head morphology in the ecologically diverse three-spined stickleback Gasterosteus aculeatus. Male G. aculeatus had longer heads than female G. aculeatus in all 10 anadromous, stream and lake populations examined, and head length growth rates were significantly higher in males in half of the populations sampled, indicating that differences in head size increased with body size in many populations. Despite consistently larger heads in males, there was significant variation in size-adjusted head length among populations, suggesting that the relationship between head length and body length was flexible. Inter-population differences in head length were correlated between sexes, thus population-level factors influenced head length in both sexes despite the sexual dimorphism present. Head shape variation between lake and anadromous populations was greater than that between sexes. The common divergence in head shape between sexes across populations was about twice as important as the sexual dimorphism unique to each population. Finally, much of the sexual dimorphism in head length was due to divergence in the anterior region of the head, where the primary trophic structures were found. It is unclear whether the sexual dimorphism was due to natural selection for niche divergence between sexes or sexual selection. This study improves knowledge of the magnitude, growth rate divergence, inter-population variation and location of sexual dimorphism in G. aculeatus head morphology. © 2010 The Authors. Journal compilation © 2010 The Fisheries Society of the British Isles.

Where the lake meets the sea: strong reproductive isolation is associated with adaptive divergence between lake resident and anadromous three-spined sticklebacks.

Directory of Open Access Journals (Sweden)

Mark Ravinet

Full Text Available Contact zones between divergent forms of the same species are often characterised by high levels of phenotypic diversity over small geographic distances. What processes are involved in generating such high phenotypic diversity? One possibility is that introgression and recombination between divergent forms in contact zones results in greater phenotypic and genetic polymorphism. Alternatively, strong reproductive isolation between forms may maintain distinct phenotypes, preventing homogenisation by gene flow. Contact zones between divergent freshwater-resident and anadromous stickleback (Gasterosteus aculeatus L. forms are numerous and common throughout the species distribution, offering an opportunity to examine these contrasting hypotheses in greater detail. This study reports on an interesting new contact zone located in a tidally influenced lake catchment in western Ireland, characterised by high polymorphism for lateral plate phenotypes. Using neutral and QTL-linked microsatellite markers, we tested whether the high diversity observed in this contact zone arose as a result of introgression or reproductive isolation between divergent forms: we found strong support for the latter hypothesis. Three phenotypic and genetic clusters were identified, consistent with two divergent resident forms and a distinct anadromous completely plated population that migrates in and out of the system. Given the strong neutral differentiation detected between all three morphotypes (mean FST = 0.12, we hypothesised that divergent selection between forms maintains reproductive isolation. We found a correlation between neutral genetic and adaptive genetic differentiation that support this. While strong associations between QTL linked markers and phenotypes were also observed in this wild population, our results support the suggestion that such associations may be more complex in some Atlantic populations compared to those in the Pacific. These findings provide an

FMRFamide-like immunoreactive neurons of the nervus terminalis of teleosts innervate both retina and pineal organ.

Science.gov (United States)

Ekström, P; Honkanen, T; Ebbesson, S O

1988-09-13

The tetrapeptide FMRFamide (Phe-Met-Arg-Phe-NH2) was first isolated from molluscan ganglia. Subsequently, it has become clear that vertebrate brains also contain endogenous FMRFamide-like substances. In teleosts, the neurons of the nervus terminalis contain an FMRFamide-like substance, and provide a direct innervation to the retina (Proc. Natl. Acad. Sci. U.S.A., 81 [1984] 940-944). Here we report the presence of FMRFamide-immunoreactive axonal bundles in the pineal organ of Coho salmon and three-spined sticklebacks. The largest numbers of axons were observed proximal to the brain, in the pineal stalk, while the distal part of the pineal organ contained only few axons. No FMRFamide-like-immunoreactive (IR) cell bodies were observed in the pineal organ. In adult fish it was not possible to determine the origin of these axons, due to the large numbers of FMRFamide-like IR axons in the teleost brain. However, by following the development of FMRFamide-like IR neurons in the embryonic and larval stickleback brain, it was possible to conclude that, at least in newly hatched fish, FMRFamide-like IR axons that originate in the nucleus nervus terminalis reach the pineal organ. Thus, it seems there is a direct connection between a specialized part of the chemosensory system and both the retina and the pineal organ in teleost fish.

Repeatable group differences in the collective behaviour of stickleback shoals across ecological contexts

Science.gov (United States)

2018-01-01

Establishing how collective behaviour emerges is central to our understanding of animal societies. Previous research has highlighted how universal interaction rules shape collective behaviour, and that individual differences can drive group functioning. Groups themselves may also differ considerably in their collective behaviour, but little is known about the consistency of such group variation, especially across different ecological contexts that may alter individuals' behavioural responses. Here, we test if randomly composed groups of sticklebacks differ consistently from one another in both their structure and movement dynamics across an open environment, an environment with food, and an environment with food and shelter. Based on high-resolution tracking data of the free-swimming shoals, we found large context-associated changes in the average behaviour of the groups. But despite these changes and limited social familiarity among group members, substantial and predictable behavioural differences between the groups persisted both within and across the different contexts (group-level repeatability): some groups moved consistently faster, more cohesively, showed stronger alignment and/or clearer leadership than other groups. These results suggest that among-group heterogeneity could be a widespread feature in animal societies. Future work that considers group-level variation in collective behaviour may help understand the selective pressures that shape how animal collectives form and function. PMID:29436496

Fish allergy and fish allergens

DEFF Research Database (Denmark)

Kuehn, A; Hilger, Christiane; Ollert, Markus

2016-01-01

Fish is one of the main elicitors for food allergies. For a long time, the clinical picture of fish allergy was reduced to the following features. First, fish-allergic patients suffer from a high IgE cross-reactivity among fishes so that they have to avoid all species. Second, clinically relevant...... symptoms are linked to the presence of IgE-antibodies recognizing parvalbumin, the fish panallergen. This view was challenged by results from recent studies as follows. 1. Allergic reactions which are limited to single or several fish species (mono-or oligosensitisations) apply not only to single cases...... but patients with this phenotype constitute an important sub-group among fish-allergic individuals. 2. Newly identified fish allergens, enolases, aldolases, and fish gelatin, are of high relevance as the majority of the fish-allergic individuals seem to develop specific IgE against these proteins. The present...

Conservation of the photoperiodic neuroendocrine axis among vertebrates: evidence from the teleost fish, Gasterosteus aculeatus.

Science.gov (United States)

O'Brien, Conor S; Bourdo, Ryan; Bradshaw, William E; Holzapfel, Christina M; Cresko, William A

2012-08-01

Photoperiod, or length of day, has a predictable annual cycle, making it an important cue for the timing of seasonal behavior and development in many organisms. Photoperiod is widely used among temperate and polar animals to regulate the timing of sexual maturation. The proper sensing and interpretation of photoperiod can be tightly tied to an organism's overall fitness. In photoperiodic mammals and birds the thyroid hormone pathway initiates sexual maturation, but the degree to which this pathway is conserved across other vertebrates is not well known. We use the threespine stickleback Gasterosteus aculeatus, as a representative teleost to quantify the photoperiodic response of key genes in the thyroid hormone pathway under controlled laboratory conditions. We find that the photoperiodic responses of the hormones are largely consistent amongst multiple populations, although differences suggest physiological adaptation to various climates. We conclude that the thyroid hormone pathway initiates sexual maturation in response to photoperiod in G. aculeatus, and our results show that more components of this pathway are conserved among mammals, birds, and teleost fish than was previously known. However, additional endocrinology, cell biology and molecular research will be required to define precisely which aspects of the pathway are conserved across vertebrates. Copyright © 2012 Elsevier Inc. All rights reserved.

Genome-wide DNA methylation patterns in wild samples of two morphotypes of threespine stickleback (Gasterosteus aculeatus).

Science.gov (United States)

Smith, Gilbert; Smith, Carl; Kenny, John G; Chaudhuri, Roy R; Ritchie, Michael G

2015-04-01

Epigenetic marks such as DNA methylation play important biological roles in gene expression regulation and cellular differentiation during development. To examine whether DNA methylation patterns are potentially associated with naturally occurring phenotypic differences, we examined genome-wide DNA methylation within Gasterosteus aculeatus, using reduced representation bisulfite sequencing. First, we identified highly methylated regions of the stickleback genome, finding such regions to be located predominantly within genes, and associated with genes functioning in metabolism and biosynthetic processes, cell adhesion, signaling pathways, and blood vessel development. Next, we identified putative differentially methylated regions (DMRs) of the genome between complete and low lateral plate morphs of G. aculeatus. We detected 77 DMRs that were mainly located in intergenic regions. Annotations of genes associated with these DMRs revealed potential functions in a number of known divergent adaptive phenotypes between G. aculeatus ecotypes, including cardiovascular development, growth, and neuromuscular development. © The Author 2014. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

The dynamics of color signals in male threespine sticklebacks Gasterosteus aculeatus.

Science.gov (United States)

Hiermes, Meike; Rick, Ingolf P; Mehlis, Marion; Bakker, Theo C M

2016-02-01

Body coloration and color patterns are ubiquitous throughout the animal kingdom and vary between and within species. Recent studies have dealt with individual dynamics of various aspects of coloration, as it is in many cases a flexible trait and changes in color expression may be context-dependent. During the reproductive phase, temporal changes of coloration in the visible spectral range (400-700 nm) have been shown for many animals but corresponding changes in the ultraviolet (UV) waveband (300-400 nm) have rarely been studied. Threespine stickleback Gasterosteus aculeatus males develop conspicuous orange-red breeding coloration combined with UV reflectance in the cheek region. We investigated dynamics of color patterns including UV throughout a male breeding cycle, as well as short-term changes in coloration in response to a computer-animated rival using reflectance spectrophotometry and visual modeling, to estimate how colors would be perceived by conspecifics. We found the orange-red component of coloration to vary during the breeding cycle with respect to hue ( theta /R50) and intensity (achieved chroma/red chroma). Furthermore, color intensity in the orange-red spectral part (achieved chroma) tended to be increased after the presentation of an artificial rival. Dynamic changes in specific measures of hue and intensity in the UV waveband were not found. In general, the orange-red component of the signal seems to be dynamic with respect to color intensity and hue. This accounts in particular for color changes during the breeding cycle, presumably to signal reproductive status, and with limitations as well in the intrasexual context, most likely to signal dominance or inferiority.

Microbiological spoilage of fish and fish products

DEFF Research Database (Denmark)

Gram, Lone; Huss, Hans Henrik

1996-01-01

Spoilage of fresh and lightly preserved fish products is caused by microbial action. This paper reviews the current knowledge in terms of the microbiology of fish and fish products with particular emphasis on identification of specific spoilage bacteria and the qualitative and quantitative...... biochemical indicators of spoilage. Shewanzella putrefaciens and Pseudomonas spp. are the specific spoilage bacteria of iced fresh fish regardless of the origin of the fish. Modified atmosphere stored marine fish from temperate waters are spoiled by the CO2 resistant Photobacterium phosphoreum whereas Gram......- positive bacteria are likely spoilers of CO2 packed fish from fresh or tropical waters. Fish products with high salt contents may spoil due to growth of halophilic bacteria (salted fish) or growth of anaerobic bacteria and yeasts (barrel salted fish). Whilst the spoilage of fresh and highly salted fish...

Predation on larval Atlantic herring (Clupea harengus) in inshore waters of the Baltic Sea

Science.gov (United States)

Kotterba, Paul; Moll, Dorothee; von Nordheim, Lena; Peck, Myron A.; Oesterwind, Daniel; Polte, Patrick

2017-11-01

In fishery science, early life-stage survival and development are regarded as major factors driving the population dynamics of marine fishes. During the last century, the main research focus has been on the spatio-temporal match of larval fish and appropriate food (bottom-up processes). However, these field studies are often criticised for their limited capability to disentangle their results from mortality caused by predation since these top-down mechanisms are rarely studied. We examined the predation on herring (Clupea harengus) larvae in a Baltic inshore lagoon by investigating the spatio-temporal overlap of larval herring and their potential predators such as the dominant threespine stickleback (Gasterosteus aculeatus) in distinct habitats (sublittoral and littoral areas) using a set of different gears and sampling techniques. Despite significant spatial and temporal predator-prey overlap, stomach analyses suggested that very few larvae were consumed by sticklebacks, even if projected to the entire study area and season. Other well-known predators of clupeid larvae such as gelatinous plankton occur later in the year after young herring have migrated out of the system. The observed predation on herring larvae was much less than expected and appears being a minor factor in determining herring reproduction success in our study area, particularly if compared to other causes of mortality such as egg predation. Providing a relatively good shelter from predation might be a key element making transitional waters valuable nursery grounds for the offspring of migrating marine fish species.

Seasonal variation in parasite infection patterns of marine fish species from the Northern Wadden Sea in relation to interannual temperature fluctuations

Science.gov (United States)

Schade, Franziska M.; Raupach, Michael J.; Mathias Wegner, K.

2016-07-01

Marine environmental conditions are naturally changing throughout the year, affecting life cycles of hosts as well as parasites. In particular, water temperature is positively correlated with the development of many parasites and pathogenic bacteria, increasing the risk of infection and diseases during summer. Interannual temperature fluctuations are likely to alter host-parasite interactions, which may result in profound impacts on sensitive ecosystems. In this context we investigated the parasite and bacterial Vibrionaceae communities of four common small fish species (three-spined stickleback Gasterosteus aculeatus, Atlantic herring Clupea harengus, European sprat Sprattus sprattus and lesser sand eel Ammodytes tobianus) in the Northern Wadden Sea over a period of two years. Overall, we found significantly increased relative diversities of infectious species at higher temperature differentials. On the taxon-specific level some macroparasite species (trematodes, nematodes) showed a shift in infection peaks that followed the water temperatures of preceding months, whereas other parasite groups showed no effects of temperature differentials on infection parameters. Our results show that even subtle changes in seasonal temperatures may shift and modify the phenology of parasites as well as opportunistic pathogens that can have far reaching consequences for sensitive ecosystems.

Microbiological spoilage of fish and fish products.

Science.gov (United States)

Gram, L; Huss, H H

1996-11-01

Spoilage of fresh and lightly preserved fish products is caused by microbial action. This paper reviews the current knowledge in terms of the microbiology of fish and fish products with particular emphasis on identification of specific spoilage bacteria and the qualitative and quantitative biochemical indicators of spoilage. Shewanella putrefaciens and Pseudomonas spp. are the specific spoilage bacteria of iced fresh fish regardless of the origin of the fish. Modified atmosphere stored marine fish from temperate waters are spoiled by the CO2 resistant Photobacterium phosphoreum whereas Gram-positive bacteria are likely spoilers of CO2 packed fish from fresh or tropical waters. Fish products with high salt contents may spoil due to growth of halophilic bacteria (salted fish) or growth of anaerobic bacteria and yeasts (barrel salted fish). Whilst the spoilage of fresh and highly salted fish is well understood, much less is known about spoilage of lightly preserved fish products. It is concluded that the spoilage is probably caused by lactic acid bacteria, certain psychotrophic Enterobacteriaceae and/or Photobacterium phosphoreum. However, more work is needed in this area.

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

African Journals Online (AJOL)

This study investigated innovation in utilization of fish tanks for fish culture among fish farmers in Obio/Akpor Local Government Area of Rivers State, Nigeria. Data for this study was obtained through the administration of questionnaire and scheduled interview to 120 sampled fish farmers randomly selected from the study ...

Fish health and fish quality

DEFF Research Database (Denmark)

Ingerslev, Hans-Christian

Aquaculture is an expanding worldwide industry producing an increasing amount of fish every year. The quality of the fish meat is dependent upon many biological and non-biological factors. Infectious diseases are known to cause bleedings and damage of the muscle tissue that may lead to scarring...... are poorly described in fish. The present work in this thesis focused on: 1) examination of potential changes in the quality regarding texture of the muscle tissue in rainbow trout (Oncorhynchus mykiss) after previous infection with the bacterial pathogens Yersinia ruckeri and Vibrio anguillarum; 2...... of these studies showed that previous infections by Yersinia ruckeri and Vibrio anguillarum gave rise to subsequent changes regarding textural quality parameters in fresh fish meat, while no differences were seen for cold-smoked meat from the same fish. The texture in previous infected fish was less flaky and less...

Fish oil quality of by-product (fish skin from swangi fish

Directory of Open Access Journals (Sweden)

La Ode Huli

2015-01-01

Full Text Available The skin of swangi fish is a potential fish skin to be produced for fish oil. The objectives of this research were aimed to determine the yield and the best quality of fish oil and also to compare fatty acid profile of the fish according to different extraction methods. Fish oil extractions were used by wet rendering method with extraction temperatures of 60, 70, 80, 90, 100°C for 20, 30, and 40 minutes. Fish oil quality was determined by the chemical oil characteristics i.e. PV, FFA, AV, anisidin, and TOTOX. Fatty acid profile was analyzed using gas chromatography (Shimadzu. The results of the study showed that the highest fish oil yield in each treatment was obtained extraction temperature of 60°C for 30 minutes with percentage of 0.33, (70°C for 30 minutes 0.46, (80°C for 30 minutes 1.23, (90°C for 20 minutes 1.14 and (100°C for 20 minutes 0.84. These values were lower compare to Bligh & Dyer and Soxhlet methods. Then, the best fish oil quality was resulted on temperature extraction of 60°C for 30 minutes with PV, FFA, anisidin, AV, and TOTOX were 9.17 meq/kg, 6.92%, 13,77 mg KOH/g, 0.86 meq/kg and 19.19 meq/kg, respectively. FUFA fatty acid compositions of swangi skin fish oil especially EPA and DHA in wet rendering method were gained 0.73% and 2.53%, respectively. These results were lower than Bligh & Dyer method which was consisted of 3.66% (EPA, and 13.29% (DHA and also Soxhlet extraction method with value of EPA was 2.78% and DHA was 9.62%.Keywords: EPA, extraction temperature, DHA, fish oil quality, fish skin

Fishing down the largest coral reef fish species.

Science.gov (United States)

Fenner, Douglas

2014-07-15

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

Acoustic noise induces attention shifts and reduces foraging performance in three-spined sticklebacks (Gasterosteus aculeatus.

Directory of Open Access Journals (Sweden)

Julia Purser

2011-02-01

Full Text Available Acoustic noise is known to have a variety of detrimental effects on many animals, including humans, but surprisingly little is known about its impacts on foraging behaviour, despite the obvious potential consequences for survival and reproductive success. We therefore exposed captive three-spined sticklebacks (Gasterosteus aculeatus to brief and prolonged noise to investigate how foraging performance is affected by the addition of acoustic noise to an otherwise quiet environment. The addition of noise induced only mild fear-related behaviours--there was an increase in startle responses, but no change in the time spent freezing or hiding compared to a silent control--and thus had no significant impact on the total amount of food eaten. However, there was strong evidence that the addition of noise increased food-handling errors and reduced discrimination between food and non-food items, results that are consistent with a shift in attention. Consequently, noise resulted in decreased foraging efficiency, with more attacks needed to consume the same number of prey items. Our results suggest that acoustic noise has the potential to influence a whole host of everyday activities through effects on attention, and that even very brief noise exposure can cause functionally significant impacts, emphasising the threat posed by ever-increasing levels of anthropogenic noise in the environment.

Individual variation in habituation: behaviour over time toward different stimuli in threespine sticklebacks (Gasterosteus aculeatus)

Science.gov (United States)

Bell, Alison M.; Peeke, Harman V.S.

2014-01-01

Habituation, or the relatively permanent waning of a response as a result of repeated stimulation, is a form of behavioural plasticity that allows animals to filter out irrelevant stimuli and to focus selectively on important stimuli. Individuals that fail to habituate might be at a disadvantage if they continue to respond to irrelevant stimuli; therefore, habituation can have adaptive significance. In this study we compared rates of behaviour over time toward three different ecologically-relevant stimuli (food, a male intruder and a gravid female) in threespine sticklebacks (Gasterosteus aculeatus). We detected evidence for habituation to the stimuli, and males in this study were especially aggressive toward both male and female conspecifics. Although there were some clear temporal patterns that could be detected by looking at average behaviour, not all individuals behaved in the same ‘average’ way. We detected substantial inter-individual variation in behaviour toward all three stimuli, inter-individual variation in rates of habituation to both male and female conspecifics, but no evidence for correlations between behaviours across stimuli (behavioural syndromes). These results suggest that individual animals vary in rates of habituation, and prompt hypotheses about the causes and consequences of variation in rates of habituation. PMID:25678715

Genetic Coupling of Female Mate Choice with Polygenic Ecological Divergence Facilitates Stickleback Speciation.

Science.gov (United States)

Bay, Rachael A; Arnegard, Matthew E; Conte, Gina L; Best, Jacob; Bedford, Nicole L; McCann, Shaugnessy R; Dubin, Matthew E; Chan, Yingguang Frank; Jones, Felicity C; Kingsley, David M; Schluter, Dolph; Peichel, Catherine L

2017-11-06

Ecological speciation with gene flow is widespread in nature [1], but it presents a conundrum: how are associations between traits under divergent natural selection and traits that contribute to assortative mating maintained? Theoretical models suggest that genetic mechanisms inhibiting free recombination between loci underlying these two types of traits (hereafter, "genetic coupling") can facilitate speciation [2-4]. Here, we perform a direct test for genetic coupling by mapping both divergent traits and female mate choice in a classic model of ecological speciation: sympatric benthic and limnetic threespine stickleback (Gasterosteus aculeatus). By measuring mate choice in F2 hybrid females, we allowed for recombination between loci underlying assortative mating and those under divergent ecological selection. In semi-natural mating arenas in which females had access to both benthic and limnetic males, we found that F2 females mated with males similar to themselves in body size and shape. In addition, we found two quantitative trait loci (QTLs) associated with female mate choice that also predicted female morphology along the benthic-limnetic trait axis. Furthermore, a polygenic genetic model that explains adaptation to contrasting benthic and limnetic feeding niches [5] also predicted F2 female mate choice. Together, these results provide empirical evidence that genetic coupling of assortative mating with traits under divergent ecological selection helps maintain species in the face of gene flow, despite a polygenic basis for adaptation to divergent environments. Copyright © 2017 Elsevier Ltd. All rights reserved.

Sex chromosome turnover contributes to genomic divergence between incipient stickleback species.

Directory of Open Access Journals (Sweden)

Kohta Yoshida

2014-03-01

Full Text Available Sex chromosomes turn over rapidly in some taxonomic groups, where closely related species have different sex chromosomes. Although there are many examples of sex chromosome turnover, we know little about the functional roles of sex chromosome turnover in phenotypic diversification and genomic evolution. The sympatric pair of Japanese threespine stickleback (Gasterosteus aculeatus provides an excellent system to address these questions: the Japan Sea species has a neo-sex chromosome system resulting from a fusion between an ancestral Y chromosome and an autosome, while the sympatric Pacific Ocean species has a simple XY sex chromosome system. Furthermore, previous quantitative trait locus (QTL mapping demonstrated that the Japan Sea neo-X chromosome contributes to phenotypic divergence and reproductive isolation between these sympatric species. To investigate the genomic basis for the accumulation of genes important for speciation on the neo-X chromosome, we conducted whole genome sequencing of males and females of both the Japan Sea and the Pacific Ocean species. No substantial degeneration has yet occurred on the neo-Y chromosome, but the nucleotide sequence of the neo-X and the neo-Y has started to diverge, particularly at regions near the fusion. The neo-sex chromosomes also harbor an excess of genes with sex-biased expression. Furthermore, genes on the neo-X chromosome showed higher non-synonymous substitution rates than autosomal genes in the Japan Sea lineage. Genomic regions of higher sequence divergence between species, genes with divergent expression between species, and QTL for inter-species phenotypic differences were found not only at the regions near the fusion site, but also at other regions along the neo-X chromosome. Neo-sex chromosomes can therefore accumulate substitutions causing species differences even in the absence of substantial neo-Y degeneration.

Fish welfare: Fish capacity to experience pain

Directory of Open Access Journals (Sweden)

Vučinić Marijana

2009-01-01

Full Text Available Teleost fish possess similar nociceptive processing systems to those found in terrestrial vertebrates. It means that they react to potential painful stimuli in a similar manner as mammals and birds. However, the welfare of fish has been the focus of less research than that of higher vertebrates. Humans may affect the welfare of fish through fisheries, aquaculture and a number of other activities. There is scientific evidence to support the assumption that fish have the capacity to experience pain because they possess functional nociceptors, endogenous opioids and opioid receptors, brain structures involved in pain processing and pathways leading from nociceptors to higher brain structures. Also, it is well documented that some anaesthetics and analgesics may reduce nociceptive responses in fish. Behavioural indicators in fish such as lip-rubbing and rocking behaviours are the best proof that fish react to potential painful stimuli. This paper is an overview of some scientific evidence on fish capacity to experience pain.

Fish-allergic patients may be able to eat fish.

Science.gov (United States)

Mourad, Ahmad A; Bahna, Sami L

2015-03-01

Reported fish allergy prevalence varies widely, with an estimated prevalence of 0.2% in the general population. Sensitization to fish can occur by ingestion, skin contact or inhalation. The manifestations can be IgE or non-IgE mediated. Several fish allergens have been identified, with parvalbumins being the major allergen in various species. Allergenicity varies among fish species and is affected by processing or preparation methods. Adverse reactions after eating fish are often claimed to be 'allergy' but could be a reaction to hidden food allergen, fish parasite, fish toxins or histamine in spoiled fish. Identifying such causes would allow free consumption of fish. Correct diagnosis of fish allergy, including the specific species, might provide the patient with safe alternatives. Patients have been generally advised for strict universal avoidance of fish. However, testing with various fish species or preparations might identify one or more forms that can be tolerated.

Fish Allergy

Science.gov (United States)

... Cause Blog Vision Awards Common Allergens Fish Allergy Fish Allergy Learn about fish allergy, how to read ... that you must avoid both. Allergic Reactions to Fish Finned fish can cause severe and potentially life- ...

Cooperation under Predation Risk: Experiments on Costs and Benefits

Science.gov (United States)

Milinski, Manfred; Luthi, Jean H.; Eggler, Rolf; Parker, Geoffrey A.

1997-06-01

Two fish that cooperatively inspect a predator may have negotiated the share of the risk that each takes. A test of both the costs of predator inspection dependent on the distance from which the predator is approached and the potential benefits of cooperation was carried out strictly experimentally. We made either singletons or pairs of dead sticklebacks, Gasterosteus aculeatus, approach hungry pike, Esox lucius, by remote control according to an algorithm that mimicked natural inspection. The predation risk of both single inspectors and parallel inspecting pairs increased with closer inspection distances. A member of an inspecting pair had only about half the risk of that of a single inspector. In pairs, a companion diluted the lead fish's risk of being caught, depending on its distance behind the leader. The absolute risk difference between leader and follower was greatest for close inspection distances and decreased further away from the predator. The leader's relative risk increased with its distance ahead of the laggard. However, for a given distance between leader and laggard, the relative risks to the two fish remained similar with distance from the predator. The cost side of the inequalities that define a 'Prisoner's Dilemma' has thus been measured for this system. In a second experiment the 'attack deterrence hypothesis' of predator inspection (i.e. inspection decreases attack probability) was tested. The pike was offered a choice between two sticklebacks, one of which had carried out a predator inspection visit. There was no indication of attack deterrence through predator inspection.

Color and behavior differently predict competitive outcomes for divergent stickleback color morphs

Science.gov (United States)

Lehto, Whitley R; Lierheimer, V Faith

2018-01-01

Abstract Our knowledge of how male competition contributes to speciation is dominated by investigations of competition between within-species morphs or closely related species that differ in conspicuous traits expressed during the breeding season (e.g. color, song). In such studies, it is important to consider the manner in which putatively sexually selected traits influence the outcome of competitive interactions within and between types because these traits can communicate information about competitor quality and may not be utilized by homotypic and heterotypic receivers in the same way. We studied the roles of breeding color and aggressive behaviors in competition within and between two divergent threespine stickleback Gasterosteus aculeatus color types. Our previous work in this system showed that the switch from red to black breeding coloration is associated with changes in male competition biases. Here, we find that red and black males also use different currencies in competition. Winners of both color types performed more aggressive behaviors than losers, regardless of whether the competitor was of the same or opposite color type. But breeding color differently predicted competitive outcomes for red and black males. Males who were redder at the start of competition were more likely to win when paired with homotypic competitors and less likely to win when paired with heterotypic competitors. In contrast, black color, though expressed in the breeding season and condition dependent, was unrelated to competitive outcomes. Placing questions about the role of male competition in speciation in a sexual signal evolution framework may provide insight into the “why and how” of aggression biases and asymmetries in competitive ability between closely related morphs and species. PMID:29492044

Divergence in sex steroid hormone signaling between sympatric species of Japanese threespine stickleback.

Directory of Open Access Journals (Sweden)

Jun Kitano

Full Text Available Sex steroids mediate the expression of sexually dimorphic or sex-specific traits that are important both for mate choice within species and for behavioral isolation between species. We investigated divergence in sex steroid signaling between two sympatric species of threespine stickleback (Gasterosteus aculeatus: the Japan Sea form and the Pacific Ocean form. These sympatric forms diverge in both male display traits and female mate choice behaviors, which together contribute to asymmetric behavioral isolation in sympatry. Here, we found that plasma levels of testosterone and 17β-estradiol differed between spawning females of the two sympatric forms. Transcript levels of follicle-stimulating hormone-β (FSHβ gene were also higher in the pituitary gland of spawning Japan Sea females than in the pituitary gland of spawning Pacific Ocean females. By contrast, none of the sex steroids examined were significantly different between nesting males of the two forms. However, combining the plasma sex steroid data with testis transcriptome data suggested that the efficiency of the conversion of testosterone into 11-ketotestosterone has likely diverged between forms. Within forms, plasma testosterone levels in males were significantly correlated with male body size, a trait important for female mate choice in the two sympatric species. These results demonstrate that substantial divergence in sex steroid signaling can occur between incipient sympatric species. We suggest that investigation of the genetic and ecological mechanisms underlying divergence in hormonal signaling between incipient sympatric species will provide a better understanding of the mechanisms of speciation in animals.

Repeatability in nest construction by male three-spined sticklebacks

NARCIS (Netherlands)

Rushbrook, B. J.; Dingemanse, N. J.; Barber, I.

Structures built by animals may convey useful information about the builder that may be used by conspecifics in quality assessment. In fish, nest construction has been suggested to reflect qualities of individual builders, but little is known about how consistent individual differences are over

49 CFR 173.218 - Fish meal or fish scrap.

Science.gov (United States)

2010-10-01

... 49 Transportation 2 2010-10-01 2010-10-01 false Fish meal or fish scrap. 173.218 Section 173.218... Fish meal or fish scrap. (a) Except as provided in Column (7) of the HMT in § 172.101 of this subchapter, fish meal or fish scrap, containing at least 6%, but not more than 12% water, is authorized for...

Fish Ontology framework for taxonomy-based fish recognition

Science.gov (United States)

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

2017-01-01

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

Fish Ontology framework for taxonomy-based fish recognition

Directory of Open Access Journals (Sweden)

Najib M. Ali

2017-09-01

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

Diet of yellow-billed loons (Gavia adamsii) in Arctic lakes during the nesting season inferred from fatty acid analysis

Science.gov (United States)

Haynes, T B; Schmutz, Joel A.; Bromaghin, Jeffrey F.; Iverson, S J; Padula, V. M.; Rosenberger, A E

2015-01-01

Understanding the dietary habits of yellow-billed loons (Gavia adamsii) can give important insights into their ecology, however, studying the diet of loons is difficult when direct observation or specimen collection is impractical. We investigate the diet of yellow-billed loons nesting on the Arctic Coastal Plain of Alaska using quantitative fatty acid signature analysis. Tissue analysis from 26 yellow-billed loons and eleven prey groups (nine fish species and two invertebrate groups) from Arctic lakes suggests that yellow-billed loons are eating high proportions of Alaska blackfish (Dallia pectoralis), broad whitefish (Coregonus nasus) and three-spined stickleback (Gasterosteus aculeatus) during late spring and early summer. The prominence of blackfish in diets highlights the widespread availability of blackfish during the early stages of loon nesting, soon after spring thaw. The high proportions of broad whitefish and three-spined stickleback may reflect a residual signal from the coastal staging period prior to establishing nesting territories on lakes, when loons are more likely to encounter these species. Our analyses were sensitive to the choice of calibration coefficient based on data from three different species, indicating the need for development of loon-specific coefficients for future study and confirmation of our results. Regardless, fish that are coastally distributed and that successfully overwinter in lakes are likely key food items for yellow-billed loons early in the nesting season.

Erection of Ceratonova n. gen. (Myxosporea: Ceratomyxidae) to encompass freshwater species C. gasterostea n. sp. from threespine stickleback (Gasterosteus aculeatus) and C. shasta n. comb. from salmonid fishes.

Science.gov (United States)

Atkinson, S D; Foott, J S; Bartholomew, J L

2014-10-01

Ceratonova gasterostea n. gen. n. sp. is described from the intestine of freshwater Gasterosteus aculeatus L. from the Klamath River, California. Myxospores are arcuate, 22.4 ± 2.6 μm thick, 5.2 ± 0.4 μm long, posterior angle 45° ± 24°, with 2 sub-spherical polar capsules, diameter 2.3 ± 0.2 μm, which lie adjacent to the suture. Its ribosomal small subunit sequence was most similar to an intestinal parasite of salmonid fishes, Ceratomyxa shasta (97%, 1,671/1,692 nucleotides), and distinct from all other Ceratomyxa species (<85%), which are typically coelozoic parasites in the gall bladder or urinary system of marine fishes. We propose erection of genus Ceratonova to contain both intestinal, freshwater species and reassign the salmonid parasite as Ceratonova shasta n. comb.

Do bacteria, not fish, produce 'fish kairomone'?

NARCIS (Netherlands)

Ringelberg, J.; Van Gool, E.

1998-01-01

Fish-associated chemicals enhance phototactic downward swimming in Daphnia. If perch were treated with the antibiotic ampicillin, this enhancement was significantly decreased. Therefore, not fish, but bacteria associated with fish, seem to produce this kairomone. [KEYWORDS: Diel vertical migration;

Adoption Of Improved Fish Technologies Among Fish Farmers In ...

African Journals Online (AJOL)

A shortfall exists between fish supply and fish demand in the country despite the introduction of improved technology to fish farmers. This led to huge wage bill on the importation of fish to meet the protein need of the ever increasing population. This prompted this study with focus on adoption of improved fish technologies ...

Which Fish Should I Eat? Perspectives Influencing Fish Consumption Choices

Science.gov (United States)

Choi, Anna L.; Karagas, Margaret R.; Mariën, Koenraad; Rheinberger, Christoph M.; Schoeny, Rita; Sunderland, Elsie; Korrick, Susan

2012-01-01

Background: Diverse perspectives have influenced fish consumption choices. Objectives: We summarized the issue of fish consumption choice from toxicological, nutritional, ecological, and economic points of view; identified areas of overlap and disagreement among these viewpoints; and reviewed effects of previous fish consumption advisories. Methods: We reviewed published scientific literature, public health guidelines, and advisories related to fish consumption, focusing on advisories targeted at U.S. populations. However, our conclusions apply to groups having similar fish consumption patterns. Discussion: There are many possible combinations of matters related to fish consumption, but few, if any, fish consumption patterns optimize all domains. Fish provides a rich source of protein and other nutrients, but because of contamination by methylmercury and other toxicants, higher fish intake often leads to greater toxicant exposure. Furthermore, stocks of wild fish are not adequate to meet the nutrient demands of the growing world population, and fish consumption choices also have a broad economic impact on the fishing industry. Most guidance does not account for ecological and economic impacts of different fish consumption choices. Conclusion: Despite the relative lack of information integrating the health, ecological, and economic impacts of different fish choices, clear and simple guidance is necessary to effect desired changes. Thus, more comprehensive advice can be developed to describe the multiple impacts of fish consumption. In addition, policy and fishery management inter-ventions will be necessary to ensure long-term availability of fish as an important source of human nutrition. PMID:22534056

Fish Rhabdoviruses

Science.gov (United States)

Kurath, G.; Winton, J.

2008-01-01

Many important viral pathogens of fish are members of the family Rhabdoviridae. The viruses in this large group cause significant losses in populations of wild fish as well as among fish reared in aquaculture. Fish rhabdoviruses often have a wide host and geographic range, and infect aquatic animals in both freshwater and seawater. The fish rhabdoviruses comprise a diverse collection of isolates that can be placed in one of two quite different groups: isolates that are members of the established genusNovirhabdovirus, and those that are most similar to members of the genus Vesiculovirus. Because the diseases caused by fish rhabdoviruses are important to aquaculture, diagnostic methods for their detection and identification are well established. In addition to regulations designed to reduce the spread of fish viruses, a significant body of research has addressed methods for the control or prevention of diseases caused by fish rhabdoviruses, including vaccination. The number of reported fish rhabdoviruses continues to grow as a result of the expansion of aquaculture, the increase in global trade, the development of improved diagnostic methods, and heightened surveillance activities. Fish rhabdoviruses serve as useful components of model systems to study vertebrate virus disease, epidemiology, and immunology.

Fish for Feed vs Fish for Food

OpenAIRE

Allan, Geoff L.

2004-01-01

Aquaculture is the fastest-growing food producing industry sector in the world. Demand for feed ingredients, particularly for preferred protein sources such as fishmeal, fish oil and ‘trash fish’, has also increased, raising questions about sustainability and uses of fish for aquaculture feeds or directly as human food. Approximately 30 million metric tonnes (MMT) of fish from capture fisheries are used each year to produce fishmeal and fish oil. The species used are not usually consumed dire...

Fish Allergy

Science.gov (United States)

... Safe Videos for Educators Search English Español Fish Allergy KidsHealth / For Parents / Fish Allergy What's in this ... Print en español Alergia al pescado About Fish Allergy A fish allergy is not exactly the same ...

Genomic arrangement of salinity tolerance QTLs in salmonids: A comparative analysis of Atlantic salmon (Salmo salar with Arctic charr (Salvelinus alpinus and rainbow trout (Oncorhynchus mykiss

Directory of Open Access Journals (Sweden)

Norman Joseph D

2012-08-01

Full Text Available Abstract Background Quantitative trait locus (QTL studies show that variation in salinity tolerance in Arctic charr and rainbow trout has a genetic basis, even though both these species have low to moderate salinity tolerance capacities. QTL were observed to localize to homologous linkage group segments within putative chromosomal regions possessing multiple candidate genes. We compared salinity tolerance QTL in rainbow trout and Arctic charr to those detected in a higher salinity tolerant species, Atlantic salmon. The highly derived karyotype of Atlantic salmon allows for the assessment of whether disparity in salinity tolerance in salmonids is associated with differences in genetic architecture. To facilitate these comparisons, we examined the genomic synteny patterns of key candidate genes in the other model teleost fishes that have experienced three whole-genome duplication (3R events which preceded a fourth (4R whole genome duplication event common to all salmonid species. Results Nine linkage groups contained chromosome-wide significant QTL (AS-2, -4p, -4q, -5, -9, -12p, -12q, -14q -17q, -22, and −23, while a single genome-wide significant QTL was located on AS-4q. Salmonid genomes shared the greatest marker homology with the genome of three-spined stickleback. All linkage group arms in Atlantic salmon were syntenic with at least one stickleback chromosome, while 18 arms had multiple affinities. Arm fusions in Atlantic salmon were often between multiple regions bearing salinity tolerance QTL. Nine linkage groups in Arctic charr and six linkage group arms in rainbow trout currently have no synteny alignments with stickleback chromosomes, while eight rainbow trout linkage group arms were syntenic with multiple stickleback chromosomes. Rearrangements in the stickleback lineage involving fusions of ancestral arm segments could account for the 21 chromosome pairs observed in the stickleback karyotype. Conclusions Salinity tolerance in

Persistent and plastic effects of temperature on DNA methylation across the genome of threespine stickleback (Gasterosteus aculeatus).

Science.gov (United States)

Metzger, David C H; Schulte, Patricia M

2017-10-11

Epigenetic mechanisms such as changes in DNA methylation have the potential to affect the resilience of species to climate change, but little is known about the response of the methylome to changes in environmental temperature in animals. Using reduced representation bisulfite sequencing, we assessed the effects of development temperature and adult acclimation temperature on DNA methylation levels in threespine stickleback ( Gasterosteus aculeatus ). Across all treatments, we identified 2130 differentially methylated cytosines distributed across the genome. Both increases and decreases in temperature during development and with thermal acclimation in adults increased global DNA methylation levels. Approximately 25% of the differentially methylated regions (DMRs) responded to both developmental temperature and adult thermal acclimation, and 50 DMRs were common to all treatments, demonstrating a core response of the epigenome to thermal change at multiple time scales. We also identified differentially methylated loci that were specific to a particular developmental or adult thermal response, which could facilitate the accumulation of epigenetic variation between natural populations that experience different thermal regimes. These data demonstrate that thermal history can have long-lasting effects on the epigenome, highlighting the role of epigenetic modifications in the response to temperature change across multiple time scales. © 2017 The Author(s).

A flexible whole-genome microarray for transcriptomics in three-spine stickleback (Gasterosteus aculeatus

Directory of Open Access Journals (Sweden)

Primmer Craig R

2009-09-01

Full Text Available Abstract Background The use of microarray technology for describing changes in mRNA expression to address ecological and evolutionary questions is becoming increasingly popular. Since three-spine stickleback are an important ecological and evolutionary model-species as well as an emerging model for eco-toxicology, the ability to have a functional and flexible microarray platform for transcriptome studies will greatly enhance the research potential in these areas. Results We designed 43,392 unique oligonucleotide probes representing 19,274 genes (93% of the estimated total gene number, and tested the hybridization performance of both DNA and RNA from different populations to determine the efficacy of probe design for transcriptome analysis using the Agilent array platform. The majority of probes were functional as evidenced by the DNA hybridization success, and 30,946 probes (14,615 genes had a signal that was significantly above background for RNA isolated from liver tissue. Genes identified as being expressed in liver tissue were grouped into functional categories for each of the three Gene Ontology groups: biological process, molecular function, and cellular component. As expected, the highest proportions of functional categories belonged to those associated with metabolic functions: metabolic process, binding, catabolism, and organelles. Conclusion The probe and microarray design presented here provides an important step facilitating transcriptomics research for this important research organism by providing a set of over 43,000 probes whose hybridization success and specificity to liver expression has been demonstrated. Probes can easily be added or removed from the current design to tailor the array to specific experiments and additional flexibility lies in the ability to perform either one-color or two-color hybridizations.

Landscape genetics of Schistocephalus solidus parasites in threespine stickleback (Gasterosteus aculeatus) from Alaska.

Science.gov (United States)

Sprehn, C Grace; Blum, Michael J; Quinn, Thomas P; Heins, David C

2015-01-01

The nature of gene flow in parasites with complex life cycles is poorly understood, particularly when intermediate and definitive hosts have contrasting movement potential. We examined whether the fine-scale population genetic structure of the diphyllobothriidean cestode Schistocephalus solidus reflects the habits of intermediate threespine stickleback hosts or those of its definitive hosts, semi-aquatic piscivorous birds, to better understand complex host-parasite interactions. Seventeen lakes in the Cook Inlet region of south-central Alaska were sampled, including ten in the Matanuska-Susitna Valley, five on the Kenai Peninsula, and two in the Bristol Bay drainage. We analyzed sequence variation across a 759 bp region of the mitochondrial DNA (mtDNA) cytochrome oxidase I region for 1,026 S. solidus individuals sampled from 2009-2012. We also analyzed allelic variation at 8 microsatellite loci for 1,243 individuals. Analysis of mtDNA haplotype and microsatellite genotype variation recovered evidence of significant population genetic structure within S. solidus. Host, location, and year were factors in structuring observed genetic variation. Pairwise measures revealed significant differentiation among lakes, including a pattern of isolation-by-distance. Bayesian analysis identified three distinct genotypic clusters in the study region, little admixture within hosts and lakes, and a shift in genotype frequencies over time. Evidence of fine-scale population structure in S. solidus indicates that movement of its vagile, definitive avian hosts has less influence on gene flow than expected based solely on movement potential. Observed patterns of genetic variation may reflect genetic drift, behaviors of definitive hosts that constrain dispersal, life history of intermediate hosts, and adaptive specificity of S. solidus to intermediate host genotype.

Landscape genetics of Schistocephalus solidus parasites in threespine stickleback (Gasterosteus aculeatus from Alaska.

Directory of Open Access Journals (Sweden)

C Grace Sprehn

Full Text Available The nature of gene flow in parasites with complex life cycles is poorly understood, particularly when intermediate and definitive hosts have contrasting movement potential. We examined whether the fine-scale population genetic structure of the diphyllobothriidean cestode Schistocephalus solidus reflects the habits of intermediate threespine stickleback hosts or those of its definitive hosts, semi-aquatic piscivorous birds, to better understand complex host-parasite interactions. Seventeen lakes in the Cook Inlet region of south-central Alaska were sampled, including ten in the Matanuska-Susitna Valley, five on the Kenai Peninsula, and two in the Bristol Bay drainage. We analyzed sequence variation across a 759 bp region of the mitochondrial DNA (mtDNA cytochrome oxidase I region for 1,026 S. solidus individuals sampled from 2009-2012. We also analyzed allelic variation at 8 microsatellite loci for 1,243 individuals. Analysis of mtDNA haplotype and microsatellite genotype variation recovered evidence of significant population genetic structure within S. solidus. Host, location, and year were factors in structuring observed genetic variation. Pairwise measures revealed significant differentiation among lakes, including a pattern of isolation-by-distance. Bayesian analysis identified three distinct genotypic clusters in the study region, little admixture within hosts and lakes, and a shift in genotype frequencies over time. Evidence of fine-scale population structure in S. solidus indicates that movement of its vagile, definitive avian hosts has less influence on gene flow than expected based solely on movement potential. Observed patterns of genetic variation may reflect genetic drift, behaviors of definitive hosts that constrain dispersal, life history of intermediate hosts, and adaptive specificity of S. solidus to intermediate host genotype.

Brain morphology of the threespine stickleback (Gasterosteus aculeatus) varies inconsistently with respect to habitat complexity: A test of the Clever Foraging Hypothesis.

Science.gov (United States)

Ahmed, Newaz I; Thompson, Cole; Bolnick, Daniel I; Stuart, Yoel E

2017-05-01

The Clever Foraging Hypothesis asserts that organisms living in a more spatially complex environment will have a greater neurological capacity for cognitive processes related to spatial memory, navigation, and foraging. Because the telencephalon is often associated with spatial memory and navigation tasks, this hypothesis predicts a positive association between telencephalon size and environmental complexity. The association between habitat complexity and brain size has been supported by comparative studies across multiple species but has not been widely studied at the within-species level. We tested for covariation between environmental complexity and neuroanatomy of threespine stickleback ( Gasterosteus aculeatus ) collected from 15 pairs of lakes and their parapatric streams on Vancouver Island. In most pairs, neuroanatomy differed between the adjoining lake and stream populations. However, the magnitude and direction of this difference were inconsistent between watersheds and did not covary strongly with measures of within-site environmental heterogeneity. Overall, we find weak support for the Clever Foraging Hypothesis in our study.

Fish consumption and track to a fish feed formulation

Science.gov (United States)

Cai-Juan, Soong; Ramli, Razamin; Rahman, Rosshairy Abdul

2015-12-01

Strategically located in the equator, Malaysia is blessed with plenty of fish supply. The high demand in fish consumption has helped the development in the fishery industry and provided numerous jobs in the secondary sector, contributing significantly to the nation's income. A survey was conducted to understand the trend of current demands for fish for the purpose of designing a feed formulation, which is still limited in this area of study. Results showed that grouper fish in restaurants commanded a very high price compared to other species of fish. Tiger grouper gained the highest demand in most restaurants, while giant grouper had the highest price in restaurants. Due to the demand and challenges to culture this type of fish, a framework for fish feed formulation is proposed. The formulation framework when materialized could be an alternative to the use of trash fish as the feed for grouper.

75 FR 6058 - Federal Sport Fish Restoration; California Department of Fish and Game Fish Hatchery and Stocking...

Science.gov (United States)

2010-02-05

...] Federal Sport Fish Restoration; California Department of Fish and Game Fish Hatchery and Stocking Program... (NEPA) of 1969, as amended, for the EIR/EIS jointly prepared with CDFG. Under the Sport Fish Restoration... has authority to grant Federal funds from the Sport Fish Restoration and Boating Trust Fund to support...

Relative and combined effects of habitat and fishing on reef fish communities across a limited fishing gradient at Ningaloo.

Science.gov (United States)

Wilson, Shaun K; Babcock, Russ C; Fisher, Rebecca; Holmes, Thomas H; Moore, James A Y; Thomson, Damian P

2012-10-01

Habitat degradation and fishing are major drivers of temporal and spatial changes in fish communities. The independent effects of these drivers are well documented, but the relative importance and interaction between fishing and habitat shifts is poorly understood, particularly in complex systems such as coral reefs. To assess the combined and relative effects of fishing and habitat we examined the composition of fish communities on patch reefs across a gradient of high to low structural complexity in fished and unfished areas of the Ningaloo Marine Park, Western Australia. Biomass and species richness of fish were positively correlated with structural complexity of reefs and negatively related to macroalgal cover. Total abundance of fish was also positively related to structural complexity, however this relationship was stronger on fished reefs than those where fishing is prohibited. The interaction between habitat condition and fishing pressure is primarily due to the high abundance of small bodied planktivorous fish on fished reefs. However, the influence of management zones on the abundance and biomass of predators and target species is small, implying spatial differences in fishing pressure are low and unlikely to be driving this interaction. Our results emphasise the importance of habitat in structuring reef fish communities on coral reefs especially when gradients in fishing pressure are low. The influence of fishing effort on this relationship may however become more important as fishing pressure increases. Copyright © 2012 Elsevier Ltd. All rights reserved.

Fishing degrades size structure of coral reef fish communities.

Science.gov (United States)

Robinson, James P W; Williams, Ivor D; Edwards, Andrew M; McPherson, Jana; Yeager, Lauren; Vigliola, Laurent; Brainard, Russell E; Baum, Julia K

2017-03-01

Fishing pressure on coral reef ecosystems has been frequently linked to reductions of large fishes and reef fish biomass. Associated impacts on overall community structure are, however, less clear. In size-structured aquatic ecosystems, fishing impacts are commonly quantified using size spectra, which describe the distribution of individual body sizes within a community. We examined the size spectra and biomass of coral reef fish communities at 38 US-affiliated Pacific islands that ranged in human presence from near pristine to human population centers. Size spectra 'steepened' steadily with increasing human population and proximity to market due to a reduction in the relative biomass of large fishes and an increase in the dominance of small fishes. Reef fish biomass was substantially lower on inhabited islands than uninhabited ones, even at inhabited islands with the lowest levels of human presence. We found that on populated islands size spectra exponents decreased (analogous to size spectra steepening) linearly with declining biomass, whereas on uninhabited islands there was no relationship. Size spectra were steeper in regions of low sea surface temperature but were insensitive to variation in other environmental and geomorphic covariates. In contrast, reef fish biomass was highly sensitive to oceanographic conditions, being influenced by both oceanic productivity and sea surface temperature. Our results suggest that community size structure may be a more robust indicator than fish biomass to increasing human presence and that size spectra are reliable indicators of exploitation impacts across regions of different fish community compositions, environmental drivers, and fisheries types. Size-based approaches that link directly to functional properties of fish communities, and are relatively insensitive to abiotic variation across biogeographic regions, offer great potential for developing our understanding of fishing impacts in coral reef ecosystems. © 2016

Essential Fish Habitat (EFH) Areas Protected From Fishing

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Designated Essential Fish Habitat (EFH) areas where fishing or the use of fishing gears has been restricted or modified in order to minimize the adverse effects of...

Fishing Fish Stem Cells and Nuclear Transplants

OpenAIRE

Hong, Yunhan

2011-01-01

Fish has been the subject of various research fields, ranging from ecology, evolution, physiology and toxicology to aquaculture. In the past decades fish has attracted considerable attention for functional genomics, cancer biology and developmental genetics, in particular nuclear transfer for understanding of cytoplasmic-nuclear relationship. This special issue reports on recent progress made in fish stem cells and nuclear transfer.

Do Fish Resist?

Directory of Open Access Journals (Sweden)

Dinesh Joseph Wadiwel

2016-03-01

Full Text Available There have been a number of scientific studies on the question of whether fish feel pain. Some have suggested that some fish indeed do feel pain and that this has significant welfare implications (2003. Others have argued that fish do not have the brain development necessary to feel pain. In terms of number of animals killed, the slaughter of sea animals for human consumption significantly exceeds that of any land animals that we use for food, and sea animal slaughter practices frequently lack any basic welfare protections. If fish can be shown to feel pain—or more importantly, if humans can agree that fish feel pain—then this would place a significant question mark over many contemporary fishing practices.  This article substitutes the question 'Do Fish Feel Pain?' with an alternative: 'Do Fish Resist?' It explores the conceptual problems of understanding fish resistance, and the politics of epistemology that surrounds and seeks to develop a conceptual framework for understanding fish resistance to human capture by exploring the development of fishing technologies - the hook, the net and contemporary aquaculture.

Annual reproductive cycle in two free living populations of three-spined stickleback (Gasterosteus aculeatus L.: patterns of ovarian and testicular development

Directory of Open Access Journals (Sweden)

Ewa Sokołowska

2006-03-01

Full Text Available The annual reproductive cycle in two wild populations of three-spinedstickleback was studied. Sticklebacks from the Dead Vistula River(Martwa Wisła (brackish water and the Oliva Stream (Potok Oliwski(freshwater were exposed to annual environmental changes in their naturalhabitats. Ovaries and livers (females, and testes and kidneys (males werecollected during 1-2 years. The gonadosomatic IG, hepatosomaticIH, nephrosomatic IN indices, kidney epithelium height(KEH and size of oocytes were calculated.The number of mature oocytes andpercentage of ovulating females were determined during the spawning season.Histological changes in the ovaries and testes were described throughouta year. Annual reproductive cycles were similar in both populations ofsticklebacks. This is the first histological and morphological study carriedout throughout a year, simultaneously in two wild populations of three-spinedsticklebacks inhabiting different environments. An improved scale of gonadaldevelopment in conjunction with the determined indices and fecundity givea comprehensive description of the reproductive cycle. These new observations,in combination with previously reported features, provide a universal scalethat can be successfully used to distinguish all phases of gametogenesis insticklebacks in different habitats.

Consumer evaluation of fish quality as basis for fish market segmentation

DEFF Research Database (Denmark)

Verbeke, Wim; Vermeir, Iris; Brunsø, Karen

2007-01-01

evaluation: personal relevance attached to fish quality and self-confidence in fish quality evaluation, which allow segmenting the market in four fish consumer segments. The segments are typified as Uninvolved, Uncertain, Self-confident and Connoisseurs, and have distinctive behavioural, attitudinal......This paper focuses on consumer evaluation of fish quality and its association with fish consumption, risk and benefit beliefs and information processing variables. Cross-sectional data were collected from a sample of 429 consumers in March 2003 in Belgium. Two dimensions shape fish quality...... and socio-demographic profiles. The Uninvolved are mainly young males, have the lowest fish consumption level, weakest belief in health benefits from eating fish, and lowest interest in both search and credence information cues. Uncertain fish consumers are mainly females, with a tendency of lower education...

Fish Commoditization: Sustainability Strategies to Protect Living Fish

Science.gov (United States)

Lam, Mimi E.; Pitcher, Tony J.

2012-01-01

The impacts of early fishing on aquatic ecosystems were minimal, as primitive technologies were used to harvest fish primarily for food. As fishing technology grew more sophisticated and human populations dispersed and expanded, local economies transitioned from subsistence to barter and trade. Expanded trade networks and mercantilization led to…

Fish silage as feed ingredient for fish and livestock

NARCIS (Netherlands)

Rurangwa, E.; Vuuren, van A.M.; Poelman, M.

2014-01-01

The present report analyses through a literature review the potential of fish silage to valorise fish processing by-products into economically relevant protein sources for fish and livestock feed production in East Africa.

Non-parallel divergence across freshwater and marine three-spined stickleback Gasterosteus aculeatus populations.

Science.gov (United States)

Pujolar, J M; Ferchaud, A L; Bekkevold, D; Hansen, M M

2017-07-01

This work investigated whether multiple freshwater populations of three-spined stickleback Gasterosteus aculeatus in different freshwater catchments in the Jutland Peninsula, Denmark, derived from the same marine populations show repeated adaptive responses. A total of 327 G. aculeatus collected at 13 sampling locations were screened for genetic variation using a combination of 70 genes putatively under selection and 26 neutral genes along with a marker linked to the ectodysplasin gene (eda), which is strongly correlated with plate armour morphs in the species. A highly significant genetic differentiation was found that was higher among different freshwater samples than between marine-freshwater samples. Tests for selection between marine and freshwater populations showed a very low degree of parallelism and no single nucleotide polymorphism was detected as outlier in all freshwater-marine pairwise comparisons, including the eda. This suggests that G. aculeatus is not necessarily the prime example of parallel local adaptation suggested in much of the literature and that important exceptions exist (i.e. the Jutland Peninsula). While marine populations in the results described here showed a high phenotype-genotype correlation at eda, a low association was found for most of the freshwater populations. The most extreme case was found in the freshwater Lake Hald where all low-plated phenotypes were either homozygotes for the allele supposed to be associated with completely plated morphs or heterozygotes, but none were homozygotes for the putative low-plated allele. Re-examination of data from seven G. aculeatus studies agrees in showing a high but partial association between phenotype-genotype at eda in G. aculeatus freshwater populations and that mismatches occur everywhere in the European regions studied (higher in some areas, i.e. Denmark). This is independent of the eda marker used. © 2017 The Fisheries Society of the British Isles.

Fish elevator and method of elevating fish

Science.gov (United States)

Truebe, Jonathan; Drooker, Michael S.

1984-01-01

A means and method for transporting fish from a lower body of water to a higher body of water. The means comprises a tubular lock with a gated entrance below the level of the lower body of water through which fish may enter the lock and a discharge passage above the level of the upper body of water. The fish raising means in the lock is a crowder pulled upward by a surface float as water from the upper body of water gravitationally flows into the closed lock filling it to the level of the upper body. Water is then pumped into the lock to raise the level to the discharge passage. The crowder is then caused to float upward the remaining distance through the water to the level of the discharge passage by the introduction of air into a pocket on the underside of the crowder. The fish are then automatically discharged from the lock into the discharge passage by the out of water position of the crowder. The movement of the fish into the discharge passage is aided by the continuous overflow of water still being pumped into the lock. A pipe may be connected to the discharge passage to deliver the fish to a selected location in the upper body of water.

Mercury and stable isotope signatures in caged marine fish and fish feeds

Energy Technology Data Exchange (ETDEWEB)

Onsanit, Sarayut; Chen, Min; Ke, Caihuan [State Key Laboratory for Marine Environmental Science, College of Oceanography and Environmental Science, Xiamen University, Xiamen 361005 (China); Wang, Wen-Xiong [State Key Laboratory for Marine Environmental Science, College of Oceanography and Environmental Science, Xiamen University, Xiamen 361005 (China)

2012-02-15

Highlights: Black-Right-Pointing-Pointer Mercury concentrations in caged fish were closely related to Hg concentrations in fish feeds. Black-Right-Pointing-Pointer The trophic transfer factor of methylmercury was dependent on fish feeds, and was the highest for fish fed on pellet feeds. Black-Right-Pointing-Pointer Fish farming may be a good way of reducing the human exposure to Hg because Hg levels can be carefully controlled. - Abstract: Total mercury (THg) and methylmercury (MeHg) concentrations were determined in four species of marine caged carnivorous fish, one species of herbivorous fish and three types of fish feeds (dried pellet feed, forage fish and fish viscera), collected from five cage sites in the rural areas along Fujian coastline, China. For the carnivorous fish, the concentrations of THg and MeHg ranged from 0.03 to 0.31 {mu}g/g and from 0.02 to 0.30 {mu}g/g on wet weight basis, respectively. The concentrations were lower for the herbivorous fish with both within the range of 0.01-0.03 {mu}g/g. Out of the three tested fish feeds, tuna viscera contained the highest level of mercury (0.20 {mu}g/g THg and 0.13 {mu}g/g MeHg), with pellet feed containing the lowest level (0.05 {mu}g/g THg and 0.01 {mu}g/g MeHg). The calculated trophic transfer factor of MeHg was the highest (12-64) for fish fed on pellet feeds, and was the lowest for fish fed on tuna viscera. A significant relationship was found between Hg concentrations in caged fish and in fish feeds, thus Hg was primarily accumulated from the diet. Furthermore, the stable isotope {delta}{sup 15}N was positively correlated with the Hg concentration in two caged sites, indicating that {delta}{sup 15}N may be a suitable tool for tracking mercury in caged fish. We conclude that fish farming may be a good way of reducing the human exposure to Hg because mercury levels can be carefully controlled in such farming systems.

Mercury and stable isotope signatures in caged marine fish and fish feeds

International Nuclear Information System (INIS)

Onsanit, Sarayut; Chen, Min; Ke, Caihuan; Wang, Wen-Xiong

2012-01-01

Highlights: ► Mercury concentrations in caged fish were closely related to Hg concentrations in fish feeds. ► The trophic transfer factor of methylmercury was dependent on fish feeds, and was the highest for fish fed on pellet feeds. ► Fish farming may be a good way of reducing the human exposure to Hg because Hg levels can be carefully controlled. - Abstract: Total mercury (THg) and methylmercury (MeHg) concentrations were determined in four species of marine caged carnivorous fish, one species of herbivorous fish and three types of fish feeds (dried pellet feed, forage fish and fish viscera), collected from five cage sites in the rural areas along Fujian coastline, China. For the carnivorous fish, the concentrations of THg and MeHg ranged from 0.03 to 0.31 μg/g and from 0.02 to 0.30 μg/g on wet weight basis, respectively. The concentrations were lower for the herbivorous fish with both within the range of 0.01–0.03 μg/g. Out of the three tested fish feeds, tuna viscera contained the highest level of mercury (0.20 μg/g THg and 0.13 μg/g MeHg), with pellet feed containing the lowest level (0.05 μg/g THg and 0.01 μg/g MeHg). The calculated trophic transfer factor of MeHg was the highest (12–64) for fish fed on pellet feeds, and was the lowest for fish fed on tuna viscera. A significant relationship was found between Hg concentrations in caged fish and in fish feeds, thus Hg was primarily accumulated from the diet. Furthermore, the stable isotope δ 15 N was positively correlated with the Hg concentration in two caged sites, indicating that δ 15 N may be a suitable tool for tracking mercury in caged fish. We conclude that fish farming may be a good way of reducing the human exposure to Hg because mercury levels can be carefully controlled in such farming systems.

Baseline identification in stable -isotope studies of temperate lotic systems and implications for calculated trophic positions

DEFF Research Database (Denmark)

Kristensen, Peter Brinkmann; Riis, Tenna; Dylmer, Hans Erik

2016-01-01

of two common fish species (three-spined stickleback, Gasterosteus aculeatus, and brown trout Salmo trutta) differed markedly depending on the baseline chosen. The estimated trophic position was lowest when based on Baetidae and highest when using Simuliidae. The trophic position of Gasterosteus...... aculeatus was independent of land use (proxy used=%nature) when based on Gammarus pulex and Simuliidae, and the trophic position of Salmo trutta was independent of land use when based on Simuliidae only. The trophic position estimates based on Baetidae and mean primary consumers correlated with %nature...

Tooth microwear formation rate in Gasterosteus aculeatus.

Science.gov (United States)

Baines, D C; Purnell, M A; Hart, P J B

2014-05-01

Tooth microwear feature densities were significantly increased in a population of laboratory-reared three-spined stickleback Gasterosteus aculeatus in four days, after they were transferred from a limnetic feeding regime to a benthic feeding regime. These results show that even in aquatic vertebrates with non-occluding teeth, changes in feeding can cause changes in tooth microwear in just a few days, as in mammals. © 2014 The Authors. Journal of Fish Biology published by John Wiley & Sons Ltd on behalf of The Fisheries Society of the British Isles.

Tendency in fishing development and fish consumption in Serbia

Directory of Open Access Journals (Sweden)

Tešić Milan

2013-01-01

Full Text Available Production and catch of fish in Serbia increases from year to year, while in the world it reached its peak at the beginning of this century. Serbia has all the favorable natural and economic conditions for further development of fishing. Out of total production, that is, annual fish catch in Serbia, the greatest part is sold by organized purchase, lower part is exported, and the reminder goes to the market through retail. It is well known that food consumption, therefore fish consumption, depends on several factors such as the production level, retail price, consumers purchasing power and their eating habits. Therefore, when analyzing the tendency of production and consumption of fish in Serbia, it is important to investigate the influence of production, price and purchasing power of consumers on it. In order to investigate the set objective, there were used corresponding quantitative data obtained by Statistical Office of the Republic of Serbia. On the basis of the original data, there were determined certain parameters, which were used as variables for calculation of correlational-regressive and maginal analysis for determining the elasticity of demand and consummation of fish per capita in Serbia. Production and catch of fish in Serbia tended to increase during the observed period, with annual growth rate of 17.4%. Beside the fact that annual growth rate is 4.8%, fish consumption per capita in Serbia is still quite small (X=4.89kg, what is a consequence of population habit to consume predominantly meat. In our study we have found out that fish consumption in Serbia mostly depend on fish production per capita (rxy=0.6364, as well as on groos (rxy=0.6045 and net (rxy=0.5969 earnings. Also, it is determined that consumption elasticity has the highest growth in regard to fish production per capita. [Projekat Ministarstva nauke Republike Srbije, br. TR 31011

Fish ladders: safe fish passage or hotspot for predation?

Directory of Open Access Journals (Sweden)

Angelo Antonio Agostinho

Full Text Available Fish ladders are a strategy for conserving biodiversity, as they can provide connectivity between fragmented habitats and reduce predation on shoals that accumulate immediately below dams. Although the impact of predation downstream of reservoirs has been investigated, especially in juvenile salmonids during their downstream movements, nothing is known about predation on Neotropical fish in the attraction and containment areas commonly found in translocation facilities. This study analysed predation in a fish passage system at the Lajeado Dam on the Tocantins River in Brazil. The abundance, distribution, and the permanence (time spent of large predatory fish along the ladder, the injuries imposed by piranhas during passage and the presence of other vertebrate predators were investigated. From December 2002 to October 2003, sampling was conducted in four regions (downstream, along the ladder, in the forebay, and upstream of the reservoir using gillnets, cast nets and counts or visual observations. The captured fish were tagged with thread and beads, and any mutilations were registered. Fish, birds and dolphins were the main predator groups observed, with a predominance of the first two groups. The entrance to the ladder, in the downstream region, was the area with the highest number of large predators and was the only region with relevant non-fish vertebrates. The main predatory fish species were Rhaphiodon vulpinus, Hydrolycus armatus, and Serrasalmus rhombeus. Tagged individuals were detected predating along the ladder for up to 90 days. Mutilations caused by Serrasalmus attacks were noted in 36% of species and 4% of individuals at the top of the ladder. Our results suggested that the high density of fish in the restricted ladder environment, which is associated with injuries suffered along the ladder course and the presence of multiple predator groups with different predation strategies, transformed the fish corridor into a hotspot for

Occurrence of PCDD/F, PCB, PBDE, PFAS, and organotin compounds in fish meal, fish oil and fish feed.

Science.gov (United States)

Suominen, K; Hallikainen, A; Ruokojärvi, P; Airaksinen, R; Koponen, J; Rannikko, R; Kiviranta, H

2011-10-01

We analysed polychlorinated dibenzo-p-dioxins and furans (PCDD/F, dioxins), and polychlorinated biphenyls (PCB) in 13 fish meal, five fish oil, and seven fish feed samples. Polybrominated diphenyl ethers (PBDE), organotin compounds (OTC), and perfluoroalkylated substances (PFAS) were analysed in ten fish meal, two fish oil, and two fish feed samples. All measured TEQ concentrations of PCDD/F and PCB were below the maximum levels set by Directive 2002/32/EC. There was no correlation between concentrations of WHOPCDD/F-TEQ and indicator PCB in our samples. The most common congeners among PBDEs were BDE-47 and BDE-100. BDE-209 was present in five fish meals of the ten analysed. Tributyltin (TBT) was the predominant congener in all samples except in three fish meals, where monobutyltin (MBT) was the major congener. Perfluorooctane sulphonate (PFOS) was the predominant congener in six fish meals of the ten analysed. There was large variation in concentrations and congener distributions of the studied compounds between our samples. Our results underline a need to pay special attention to the origin and purity of feed raw material of marine origin. Copyright © 2011 Elsevier Ltd. All rights reserved.

Fish elevator and method of elevating fish

Energy Technology Data Exchange (ETDEWEB)

Truebe, J.; Drooker, M.S.

1984-02-14

A means and method are disclosed for transporting fish from a lower body of water to a higher body of water. The means comprise a tubular lock with a gated entrance below the level of the lower body of water through which fish may enter the lock and a discharge passage above the level of the upper body of water. The fish raising means in the lock is a crowder pulled upward by a surface float as water from the upper body of water gravitationally flows into the closed lock filling it to the level of the upper body. Water is then pumped into the lock to raise the level to the discharge passage. The crowder is then caused to float upward the remaining distance through the water to the level of the discharge passage by the introduction of air into a pocket on the underside of the crowder. The fish are then automatically discharged from the lock into the discharge passage by the out of water position of the crowder. The movement of the fish into the discharge passage is aided by the continuous overflow of water still being pumped into the lock. A pipe may be connected to the discharge passage to deliver the fish to a selected location in the upper body of water. 6 figs.

Fish under exercise

NARCIS (Netherlands)

Palstra, A.P.; Planas, J.V.

2011-01-01

Improved knowledge on the swimming physiology of fish and its application to fisheries science and aquaculture (i.e., farming a fitter fish) is currently needed in the face of global environmental changes, high fishing pressures, increased aquaculture production as well as increased concern on fish

DNA metabarcoding of fish larvae for detection of non-native fishes

Science.gov (United States)

Our objective was to evaluate the use of fish larvae for early detection of non-native fishes, comparing traditional and molecular taxonomy approaches to investigate potential efficiencies. Fish larvae present an interesting opportunity for non-native fish early detection because...

Preservation of fish and fish products by use of ionizing radiation

International Nuclear Information System (INIS)

Chuaqui-Offermanns, Noemi.

1986-09-01

This report reviews the use of the radurization process in the preservation of fish and fish products. The literature describes several aspects of the process such as the fish species and the doses required, the wholesomeness of the radurized fish, and recommendations by international authorities on the applicability of the process. Areas of further research have been identified. The report concludes that radurization is an effective process for extending the shelf life of fish and fish products. Doses ranging from 0.75 to 2.5 kGy extend the shelf life two to three times compared to unirradiated controls. The loss of nutritional value at these doses is insignificant, and no deleterious short- or long-term toxicological effects have been detected in studies on animals. However, further study is required on consumer acceptance, economic feasibility, and radiation sensitivity of parasites in fish and fish products. 159 refs

Artisan fishing and the fishing company in Óbidos, Pará

Directory of Open Access Journals (Sweden)

Adriana de Aviz

2006-08-01

Full Text Available This work is product of the Project "The time of the plant: the disciplinamento of the workers of the fishing industry (Óbidos-Pará: a comparative study", developed in the years of 2002 and 2003 in the municipality of Óbidos, Pará, objectifying to understand the importance of the time in the disciplinamento of the work in the obidense fishing company. Interviews opened in entrepreneurs had been carried through of fish, controlling, heads of quality control, people in charge of hall and other actors involved in the sector fishing boat and applied half-open questionnaires with laborers and fishing. One used the photographic, recording register and the notebook of notations. The research was carried through in the fishing companies Mundial and Pasquarelli, Colony Z-19 Fishing, in the boats (river Amazon of the artisan fishing and in its residences. As central focus it was looked for to unmask the characteristics of the 'disciplined time' in the sector of improvement of the fishing company, and to detach the joint of the 'natural time' in the process of capture of the fished one. Leaving of these estimated, it was used the 'disciplined time' and the 'natural time' conceived by Thompson (1975.

Concentration of elements in whole-body fish, fish fillets, fish muscle plugs, and fish eggs from the 2008 Missouri Department of Conservation General Contaminant Monitoring Program

Science.gov (United States)

May, Thomas W.; Walther, Michael J.; Brumbaugh, William G.; McKee, Michael J.

2009-01-01

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 whole-body fish, fish fillets, fish muscle plugs, and fish eggs. Whole-body, fillet, or egg samples of catfish (Ictalurus punctatus, Ictalurus furcatus, Pylodictis olivaris), largemouth bass (Micropterus salmoides), walleye (Sander vitreus), crappie (Pomoxis annularis, Pomoxis nigromaculatus), shovelnose sturgeon (Scaphirhynchus platorynchus), northern hog sucker (Hypentelium nigricans), and Missouri saddled darter (Etheostoma tetrazonum) were collected from 23 sites as part of the Missouri Department of Conservation's Fish Contaminant Monitoring Program. Fish dorsal muscle plugs also were collected from walleye (Sander vitreus) at one of the sites.

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

Science.gov (United States)

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

2018-04-01

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

The campaign to DNA barcode all fishes, FISH-BOL.

Science.gov (United States)

Ward, R D; Hanner, R; Hebert, P D N

2009-02-01

FISH-BOL, the Fish Barcode of Life campaign, is an international research collaboration that is assembling a standardized reference DNA sequence library for all fishes. Analysis is targeting a 648 base pair region of the mitochondrial cytochrome c oxidase I (COI) gene. More than 5000 species have already been DNA barcoded, with an average of five specimens per species, typically vouchers with authoritative identifications. The barcode sequence from any fish, fillet, fin, egg or larva can be matched against these reference sequences using BOLD; the Barcode of Life Data System (http://www.barcodinglife.org). The benefits of barcoding fishes include facilitating species identification, highlighting cases of range expansion for known species, flagging previously overlooked species and enabling identifications where traditional methods cannot be applied. Results thus far indicate that barcodes separate c. 98 and 93% of already described marine and freshwater fish species, respectively. Several specimens with divergent barcode sequences have been confirmed by integrative taxonomic analysis as new species. Past concerns in relation to the use of fish barcoding for species discrimination are discussed. These include hybridization, recent radiations, regional differentiation in barcode sequences and nuclear copies of the barcode region. However, current results indicate these issues are of little concern for the great majority of specimens.

Fish parasites, fish food, and the marine environment | Nnadi ...

African Journals Online (AJOL)

The paper addresses the incontrovertible fact that fish and fish products have historically been a reliable supplier of protein, in particular, and food, in general for humans. Seventy to a hundred metric tons arc caught each year since the early seventies. Fish protein represents about twenty five percent of the total animal ...

Fish Marketing of Ribbon Fish (Trichiurus sp. in Nusantara Fishing Port (NFPat Palabuhanratu, West Java

Directory of Open Access Journals (Sweden)

Nur Bambang Azis

2018-01-01

Full Text Available The objective of this research is to study the marketing process of ribbon fish (Trichiurus sp., including the marketing margin, marketing agencies, traders and marketing channels The research was carried out for 3 mo in Nusantara Fishing Port (NFP, Palabuhanratu, Sukabumi, West Java. A case study was used in this research. A purposive sampling method was used to collect data from 55 respondents of fish marketing, consisting of fishermen, agents, traders, and retailers, who were involved in the marketing of ribbon fish in NFP Palabuhanratu. The result of the research showed that ribbon fish production in Palabuhanratu fluctuated from year to year. There are two types of ribbon fish marketing, i.e. type one is from fishermen to retailers, and type two is indirect marketing from fisherman to consumers through intermediate traders (exporters. The greatest marketing margin was obtained from the first type, while the smallest marketing margin was obtained from type two. The form of the market was considered to be oligopsony market. Fisherman’s share is greatest in the collectors and the smallest share is on retailers. Marketing process in traders is efficient due to its lowest margin and highest fisherman’s share.

21 CFR 102.45 - Fish sticks or portions made from minced fish.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 2 2010-04-01 2010-04-01 false Fish sticks or portions made from minced fish. 102... for Specific Nonstandardized Foods § 102.45 Fish sticks or portions made from minced fish. (a) The common or usual name of the food product that resembles and is of the same composition as fish sticks or...

Fish Karyome: A karyological information network database of Indian Fishes.

Science.gov (United States)

Nagpure, Naresh Sahebrao; Pathak, Ajey Kumar; Pati, Rameshwar; Singh, Shri Prakash; Singh, Mahender; Sarkar, Uttam Kumar; Kushwaha, Basdeo; Kumar, Ravindra

2012-01-01

'Fish Karyome', a database on karyological information of Indian fishes have been developed that serves as central source for karyotype data about Indian fishes compiled from the published literature. Fish Karyome has been intended to serve as a liaison tool for the researchers and contains karyological information about 171 out of 2438 finfish species reported in India and is publically available via World Wide Web. The database provides information on chromosome number, morphology, sex chromosomes, karyotype formula and cytogenetic markers etc. Additionally, it also provides the phenotypic information that includes species name, its classification, and locality of sample collection, common name, local name, sex, geographical distribution, and IUCN Red list status. Besides, fish and karyotype images, references for 171 finfish species have been included in the database. Fish Karyome has been developed using SQL Server 2008, a relational database management system, Microsoft's ASP.NET-2008 and Macromedia's FLASH Technology under Windows 7 operating environment. The system also enables users to input new information and images into the database, search and view the information and images of interest using various search options. Fish Karyome has wide range of applications in species characterization and identification, sex determination, chromosomal mapping, karyo-evolution and systematics of fishes.

50 CFR 14.23 - Live farm-raised fish and farm-raised fish eggs.

Science.gov (United States)

2010-10-01

... 50 Wildlife and Fisheries 1 2010-10-01 2010-10-01 false Live farm-raised fish and farm-raised fish eggs. 14.23 Section 14.23 Wildlife and Fisheries UNITED STATES FISH AND WILDLIFE SERVICE, DEPARTMENT OF... Exportation at Designated Ports § 14.23 Live farm-raised fish and farm-raised fish eggs. Live farm-raised fish...

Three Kinds of Fish

DEFF Research Database (Denmark)

Høst, Jeppe Engset

2012-01-01

There are three kinds of fish. Fish you were given, fish you bought and fish you lease. This might sound a bit odd, but it is nevertheless the basis for the activities of Danish commercial fishers since the introduction of transferable fishing concessions (TFCs) in 2007. In the current 2012 reform...... of market based systems are wild speculation, concentration and monopolization of fishing access and subsequent leasing with fishing communities and new entrants very likely being worse off (see for example the chapter “From fishing rights to financial derivatives” is this volume or Olson 2011; Sumaila 2010...... will examine five Danish fishing operations and discuss how they have reacted in different ways to the newly introduced system of transferable fishing concessions. By introducing TFCs as a solution to fleet overcapacity, the EU Commission will also be introducing a system where buying, selling and leasing...

Fishing Access Areas

Data.gov (United States)

Vermont Center for Geographic Information — The Vermont Fish & Wildlife Department maintains developed fishing access areas. These sites provide public access to waters in Vermont for shore fishing...

Fish consumption behavior and fish farming attitude in Kingdom of Saudi Arabia (KSA

Directory of Open Access Journals (Sweden)

Abdul Qader Khan

2018-04-01

Full Text Available This study aimed to explore fish consumption behavior and fish farming attitude of the Saudi households in the Kingdom of Saudi Arabia (KSA. The survey was conducted in Sharurah town situated in Najran province. The data were collected through a well-structured questionnaire from 100 respondents residing in the province. Pearson Correlation Coefficient was used to see the significant and non-significant impact of the two variables. The results showed that majority (37% of the respondents fell in the age group of 25–34 and majority (35% of the respondents have high level of education i.e. up to university level. The results also depicted that majority (31% of the people consume fish and were aware of the nutritional value of fish. However, majority (85% of the respondents were not satisfied by the fish price. The results further indicated that none of the respondent was engaged in fish farming activity i.e. they had no fish farms at their homes. Furthermore, majority (83% respondents had no intentions to start fish farming at their homes in future. The study concludes that fish consumption and preference is high in the study area and people prefer fish more than chicken and meat for consumption purposes because of their knowledge regarding the nutritional value of fish. However, the age and educational level have negative impact on the respondent’s opinion about fish price in the study area. The study recommends that proper policies should be formulated to educate people about fish farming (aquaponics and its importance through fisheries extension services to enhance the interest of people in fish farming. Keywords: Fish consumption, Fish farming, Attitude, Intentions, Saudi Arabia, Aquaponics

Transgenerational effects persist down the maternal line in marine sticklebacks: gene expression matches physiology in a warming ocean.

Science.gov (United States)

Shama, Lisa N S; Mark, Felix C; Strobel, Anneli; Lokmer, Ana; John, Uwe; Mathias Wegner, K

2016-10-01

Transgenerational effects can buffer populations against environmental change, yet little is known about underlying mechanisms, their persistence or the influence of environmental cue timing. We investigated mitochondrial respiratory capacity (MRC) and gene expression of marine sticklebacks that experienced acute or developmental acclimation to simulated ocean warming (21°C) across three generations. Previous work showed that acute acclimation of grandmothers to 21°C led to lower (optimized) offspring MRCs. Here, developmental acclimation of mothers to 21°C led to higher, but more efficient offspring MRCs. Offspring with a 21°C × 17°C grandmother-mother environment mismatch showed metabolic compensation: their MRCs were as low as offspring with a 17°C thermal history across generations. Transcriptional analyses showed primarily maternal but also grandmaternal environment effects: genes involved in metabolism and mitochondrial protein biosynthesis were differentially expressed when mothers developed at 21°C, whereas 21°C grandmothers influenced genes involved in hemostasis and apoptosis. Genes involved in mitochondrial respiration all showed higher expression when mothers developed at 21° and lower expression in the 21°C × 17°C group, matching the phenotypic pattern for MRCs. Our study links transcriptomics to physiology under climate change, and demonstrates that mechanisms underlying transgenerational effects persist across multiple generations with specific outcomes depending on acclimation type and environmental mismatch between generations.

From Fishing to Fish Processing: Separation of Fish from Crustaceans in the Norway Lobster-Directed Multispecies Trawl Fishery Improves Seafood Quality.

Directory of Open Access Journals (Sweden)

Junita D Karlsen

Full Text Available Fishing gears have negative impacts on seafood quality, especially on fish in the mixed trawl fishery targeting Norway lobster (Nephrops norvegicus. In this fishery, which is worth about €80 millions in Denmark alone, the quality of fish can be significantly improved by simple gear changes. A trawl codend divided into an upper and lower codend was designed to separate fish from Norway lobster during the fishing process by encourage fish to swim into the upper codend by using a frame at the entrance of the lower codend. Separate codends for fish and Norway lobster in the same gear provide the opportunity to selectively reduce small low-value fish, which will reduce catch weight and sorting time onboard the vessel. For this horizontally divided test codend and a standard codend, in which the catch was mixed, quality assessments were performed on the same batches of fish during three steps of the value chain: i aboard the fishing vessel; ii at the Fishermen's Collection Central, and iii in the production plant. Four species of fish and fillets from fish caught in the upper codend of the test codend were of significantly better quality for several of the assessed parameters compared with those caught in the standard codend: i newly caught fish showed significantly less scale loss and discolourations and had significantly better texture; ii landed fish had significantly better skin appearance and texture and significantly fewer discolourations; and iii fillets showed significantly fewer blood spots and had significantly better texture. There were no differences in injuries for newly caught fish or gaping and bruises for fillets between the test and standard codends. The decrease in catch-related damages in the test codend is explained by little contact between fish and animals with hard or spiny surfaces due to successful separation of fish and Norway lobster into the upper and lower codends, respectively, and by lower catch weight in the upper

Fish tapeworm infection

Science.gov (United States)

Fish tapeworm infection is an intestinal infection with a parasite found in fish. ... The fish tapeworm ( Diphyllobothrium latum ) is the largest parasite that infects humans. Humans become infected when they eat raw ...

Fish allergy: in review.

Science.gov (United States)

Sharp, Michael F; Lopata, Andreas L

2014-06-01

Globally, the rising consumption of fish and its derivatives, due to its nutritional value and divergence of international cuisines, has led to an increase in reports of adverse reactions to fish. Reactions to fish are not only mediated by the immune system causing allergies, but are often caused by various toxins and parasites including ciguatera and Anisakis. Allergic reactions to fish can be serious and life threatening and children usually do not outgrow this type of food allergy. The route of exposure is not only restricted to ingestion but include manual handling and inhalation of cooking vapors in the domestic and occupational environment. Prevalence rates of self-reported fish allergy range from 0.2 to 2.29 % in the general population, but can reach up to 8 % among fish processing workers. Fish allergy seems to vary with geographical eating habits, type of fish processing, and fish species exposure. The major fish allergen characterized is parvalbumin in addition to several less well-known allergens. This contemporary review discusses interesting and new findings in the area of fish allergy including demographics, novel allergens identified, immunological mechanisms of sensitization, and innovative approaches in diagnosing and managing this life-long disease.

Meet the surrogate fish

International Nuclear Information System (INIS)

Johnson, Bob; Neitzel, Duane; Moxon, Suzanne

1999-01-01

This article gives details of the US Department of Energy's innovative research into the development of a sensor system that will work as a surrogate fish to provide information to aid the design of fish-friendly turbines for hydroelectric power plants. The selection of the dams for the testing of sensor fish, the release and recovery of the sensor fish, the recording of the physical forces exerted on fish as they pass through the turbines, and use of the information gathered to build more sensor fish are discussed. Fish investigations conducted at the Pacific Northwest National Laboratory are briefly described. (UK)

Changes in the concentrations of four maternal steroids during embryonic development in the threespined stickleback (Gasterosteus aculeatus).

Science.gov (United States)

Paitz, Ryan Thomas; Mommer, Brett Christian; Suhr, Elissa; Bell, Alison Marie

2015-08-01

Embryonic exposure to steroids often leads to long-term phenotypic effects. It has been hypothesized that mothers may be able to create a steroid environment that adjusts the phenotypes of offspring to current environmental conditions. Complicating this hypothesis is the potential for developing embryos to modulate their early endocrine environment. This study utilized the threespined stickleback (Gasterosteus aculeatus) to characterize the early endocrine environment within eggs by measuring four steroids (progesterone, testosterone, estradiol, and cortisol) of maternal origin. We then examined how the concentrations of these four steroids changed over the first 12 days post fertilization (dpf). Progesterone, testosterone, estradiol, and cortisol of maternal origin could be detected within unfertilized eggs and levels of all four steroids declined in the first 3 days following fertilization. While levels of progesterone, testosterone, and estradiol remained low after the initial decline, levels of cortisol rose again by 8 dpf. These results demonstrate that G. aculeatus embryos begin development in the presence of a number of maternal steroids but levels begin to change quickly following fertilization. This suggests that embryonic processes change the early endocrine environment and hence influence the ability of maternal steroids to affect development. With these findings, G. aculeatus becomes an intriguing system in which to study how selection may act on both maternal and embryonic processes to shape the evolutionary consequence of steroid-mediated maternal effects. © 2015 Wiley Periodicals, Inc.

Identifying footprints of directional and balancing selection in marine and freshwater three-spined stickleback (Gasterosteus aculeatus) populations.

Science.gov (United States)

Mäkinen, H S; Cano, J M; Merilä, J

2008-08-01

Natural selection is expected to leave an imprint on the neutral polymorphisms at the adjacent genomic regions of a selected gene. While directional selection tends to reduce within-population genetic diversity and increase among-population differentiation, the reverse is expected under balancing selection. To identify targets of natural selection in the three-spined stickleback (Gasterosteus aculeatus) genome, 103 microsatellite and two indel markers including expressed sequence tags (EST) and quantitative trait loci (QTL)-associated loci, were genotyped in four freshwater and three marine populations. The results indicated that a high proportion of loci (14.7%) might be affected by balancing selection and a lower proportion (2.8%) by directional selection. The strongest signatures of directional selection were detected in a microsatellite locus and two indel markers located in the intronic regions of the Eda-gene coding for the number of lateral plates. Yet, other microsatellite loci previously found to be informative in QTL-mapping studies revealed no signatures of selection. Two novel microsatellite loci (Stn12 and Stn90) located in chromosomes I and VIII, respectively, showed signals of directional selection and might be linked to genomic regions containing gene(s) important for adaptive divergence. Although the coverage of the total genomic content was relatively low, the predominance of balancing selection signals is in agreement with the contention that balancing, rather than directional selection is the predominant mode of selection in the wild.

Economic differential of integrated fish, rice cum piggery and fish ...

African Journals Online (AJOL)

Fish, rice cum piggery and fish, rice cum poultry production integration platforms were set up to perfect the ideas of integrated fish farming in Sierra Leone. Water quality parameters measured biweekly included: dissolved oxygen, water temperature, pH, water hardness, water alkalinity, ammonia, nitrate, BOD and nitrite.

Effects of fire on fish populations: Landscape perspectives on persistance of native fishes and nonnative fish invasions

Science.gov (United States)

Dunham, J.B.; Young, M.; Gresswell, Robert E.; Rieman, B.

2003-01-01

Our limited understanding of the short and long-term effects of fire on fish contributes to considerable uncertainty in assessments of the risks and benefits of fire management alternatives. A primary concern among the many potential effects of fire is the effects of fire and fire management on persistence of native fish populations. Limited evidence suggests vulnerability of fish to fire is contingent upon the quality of affected habitats, the amount and distribution of habitat (habitat fragmentation), and habitat specificity of the species in question. Species with narrow habitat requirements in highly degraded and fragmented systems are likely to be most vulnerable to fire and fire-related disturbance. In addition to effects of fire on native fish, there are growing concerns about the effects of fire on nonnative fish invasions. The role of fire in facilitating invasions by nonnative fishes is unknown, but experience with other species suggests some forms of disturbance associated with fire may facilitate invasion. Management efforts to promote persistence of fishes in fire-prone landscapes can take the form of four basic alternatives: (1) pre-fire management; (2) post-fire management; (3) managing fire itself (e.g. fire fighting); and (4) monitoring and adaptive management. Among these alternatives, pre-fire management is likely to be most effective. Effective pre-fire management activities will address factors that may render fish populations more vulnerable to the effects of fire (e.g. habitat degradation, fragmentation, and nonnative species). Post-fire management is also potentially important, but suffers from being a reactive approach that may not address threats in time to avert them. Managing fire itself can be important in some contexts, but negative consequences for fish populations are possible (e.g. toxicity of fire fighting chemicals to fish). Monitoring and adaptive management can provide important new information for evaluating alternatives, but

Fish assemblages

Science.gov (United States)

McGarvey, Daniel J.; Falke, Jeffrey A.; Li, Hiram W.; Li, Judith; Hauer, F. Richard; Lamberti, G.A.

2017-01-01

Methods to sample fishes in stream ecosystems and to analyze the raw data, focusing primarily on assemblage-level (all fish species combined) analyses, are presented in this chapter. We begin with guidance on sample site selection, permitting for fish collection, and information-gathering steps to be completed prior to conducting fieldwork. Basic sampling methods (visual surveying, electrofishing, and seining) are presented with specific instructions for estimating population sizes via visual, capture-recapture, and depletion surveys, in addition to new guidance on environmental DNA (eDNA) methods. Steps to process fish specimens in the field including the use of anesthesia and preservation of whole specimens or tissue samples (for genetic or stable isotope analysis) are also presented. Data analysis methods include characterization of size-structure within populations, estimation of species richness and diversity, and application of fish functional traits. We conclude with three advanced topics in assemblage-level analysis: multidimensional scaling (MDS), ecological networks, and loop analysis.

Fish Marketing of Ribbon Fish (Trichiurus sp.) in Nusantara Fishing Port (NFP)at Palabuhanratu, West Java

Science.gov (United States)

Bambang, Azis Nur

2018-02-01

The objective of this research is to study the marketing process of ribbon fish (Trichiurus sp.), including the marketing margin, marketing agencies, traders and marketing channels The research was carried out for 3 mo in Nusantara Fishing Port (NFP), Palabuhanratu, Sukabumi, West Java. A case study was used in this research. A purposive sampling method was used to collect data from 55 respondents of fish marketing, consisting of fishermen, agents, traders, and retailers, who were involved in the marketing of ribbon fish in NFP Palabuhanratu. The result of the research showed that ribbon fish production in Palabuhanratu fluctuated from year to year. There are two types of ribbon fish marketing, i.e. type one is from fishermen to retailers, and type two is indirect marketing from fisherman to consumers through intermediate traders (exporters). The greatest marketing margin was obtained from the first type, while the smallest marketing margin was obtained from type two. The form of the market was considered to be oligopsony market. Fisherman's share is greatest in the collectors and the smallest share is on retailers. Marketing process in traders is efficient due to its lowest margin and highest fisherman's share.

Changes in the North Sea fish community: evidence of indirect effects of fishing?

DEFF Research Database (Denmark)

Daan, N.; Gislason, Henrik; Pope, J.

2005-01-01

, but such changes may simply reflect the cumulative, direct effects of fishing through selective removal of large individuals. If there is resilience in a fish community towards fishing, we may expect increases in specific components, for instance as a consequence of an associated reduction in predation and....... Taking average fishing mortality of assessed commercial species as an index of exploitation rate of the fish community, it appears that fishing effort reached its maximum in the mid-1980s and has declined slightly since. If the observed changes in the community are caused by indirect effects of fishing...

New salty waffle products "Fish Krekis" with fish & plant semifinished products

Directory of Open Access Journals (Sweden)

Fedorova Dina

2016-04-01

Full Text Available The study examines the directions of expansion of the range of wafer snack products of high nutritional value by using fish & plant semifinished products. The study scientifically grounds the benefits of using the new fish & plant semifinished products in manufacturing waffle salty snack products. The data provided in the article prove that the use of the fish & plant semifinished products & herbal ingredients enable a range of the new wafer snack products «Fish krekis» with high content of proteins, organic calcium, fiber and vitamins, with improved consumer properties, as well as more efficient use of Ukrainian raw fish materials.

Vaccination in Fish

DEFF Research Database (Denmark)

Chettri, Jiwan Kumar

vaccines have reduced the need for usage of antibiotics with more than 99 % since the 1980s. Fish can be vaccinated by three different administration routes: injection, immersion and oral vaccination. Injection vaccination (intraperitoneal injection of vaccine) is the most time consuming and labor...... intensive method, which however, provides the best protection of the fish. Immersion vaccination is used for immunization of a high number of small fish is cost-efficient and fast (30 sec immersion into vaccine). Oral vaccination (vaccine in feed) is the least efficient. As in higher vertebrates fish...... respond to vaccination by increasing the specific antibody titer and by activating the cellular responses. My talk will cover vaccination methods in fish, immune responses and some adverse effect of oil-adjuvanted vaccines in fish with reference to our work in rainbow trout, Oncorhynchus mykiss....

Fish mercury levels in lakes - adjusting for Hg and fish-size covariation

International Nuclear Information System (INIS)

Sonesten, Lars

2003-01-01

Fish-size covariation can be circumvented by regression intercepts of Hg vs. fish length as lake-specific Hg levels. - Accurate estimates of lake-specific mercury levels are vital in assessing the environmental impact on the mercury content in fish. The intercepts of lake-specific regressions of Hg concentration in fish vs. fish length provide accurate estimates when there is a prominent Hg and fish-size covariation. Commonly used regression methods, such as analysis of covariance (ANCOVA) and various standardization techniques are less suitable, since they do not completely remove the fish-size covariation when regression slopes are not parallel. Partial least squares (PLS) regression analysis reveals that catchment area and water chemistry have the strongest influence on the Hg level in fish in circumneutral lakes. PLS is a multivariate projection method that allows biased linear regression analysis of multicollinear data. The method is applicable to statistical and visual exploration of large data sets, even if there are more variables than observations. Environmental descriptors have no significant impact on the slopes of linear regressions of the Hg concentration in perch (Perca fluviatilis L.) vs. fish length, suggesting that the slopes mainly reflect ontogenetic dietary shifts during the perch life span

From fishing to fish processing: Separation of fish from crustaceans in the Norway lobster-directed multispecies trawl fishery improves seafood quality

DEFF Research Database (Denmark)

Karlsen, Junita Diana; Krag, Ludvig Ahm; Albertsen, Christoffer Moesgaard

2015-01-01

Fishing gears have negative impacts on seafood quality, especially on fish in the mixed trawl fishery targeting Norway lobster (Nephrops norvegicus). In this fishery, which is worth about €80 millions in Denmark alone, the quality of fish can be significantly improved by simple gear changes....... A trawl codend divided into an upper and lower codend was designed to separate fish from Norway lobster during the fishing process by encourage fish to swim into the upper codend by using a frame at the entrance of the lower codend. Separate codends for fish and Norway lobster in the same gear provide...... with hard or spiny surfaces due to successful separation of fish and Norway lobster into the upper and lower codends, respectively, and by lower catch weight in the upper codend of the test codend compared with the standard codend. The decrease in damages may also improve quality indirectly by inflicting...

Using Smart Packaging in Fish and Fish Based Product

Directory of Open Access Journals (Sweden)

Elif Tuğçe AKSUN

2016-11-01

Full Text Available Food packaging have three main roles during protection, preservation and storage are still involved better continuance of food quality. Evolution of civilization and improvement of new kind of food stuffs, packaging industry must created new possibilities for preventation of food quality during shelf-life. The quality and safety of perishable food is related to microbial quality has got a significance role. Fish is a very perishable food product. It is a very low acidic food and thus is very liable to the expansion of food poisoning bacteria. Also decomposition of fish can be by reason of enzymatic spoilage, oxidation and/or bacterial spoilage. Fish is an important resource of polyunsaturated fatty acids stated to have defensive effects in opposition to heartconnected diseases. Some smart packaging mechanisms liable to determine this break down incident thought storage. In this review, smart packaging technologies that could be used to detect breakdown compounds from packed fish and fish products.

Retardation Of Lipid Oxidation In Fish Oil-Enriched Fish Pâté- Combination Effects

DEFF Research Database (Denmark)

Nielsen, Nina Skall; Jacobsen, Charlotte

2013-01-01

The oxidative stability during storage of fish pâté made from cod and enriched with 5% oil was investigated. Pâtés were produced with neat fish oil, pre-emulsified fish oil, microencapsulated fish oil, inert medium chain triacylglycerol (MCT) oil or a fish/rapeseed oil mixture. Addition of fish...... stored at 2 or 10C were equally stable. Mixing fish oil with rapeseed oil before emulsification slightly increased the stability of the fish pâtés. Addition of antimicrobial agents, sodium benzoate and potassium sorbate increased oxidative stability. It is recommended to produce enriched fish pâté...... by adding pre-emulsified fish oil or microencapsulated fish oil and store at preferentially 2-10C. Practical Applications: The results from this study can directly be transferred to practical applications in the food industry. Thus, the study showed that fish oil-enriched fish pâté with an acceptable...

[Effects of fish on field resource utilization and rice growth in rice-fish coculture].

Science.gov (United States)

Zhang, Jian; Hu, Liang Liang; Ren, Wei Zheng; Guo, Liang; Wu, Min Fang; Tang, Jian Jun; Chen, Xin

2017-01-01

Rice field can provide habitat for fish and other aquatic animals. Rice-fish coculture can increase rice yield and simultaneously reduce the use of chemicals through reducing rice pest occurrence and nutrient complementary use. However, how fish uses food sources (e.g. phytoplankton, weeds, duckweed, macro-algal and snail) from rice field, and whether the nutrients releasing from those food sources due to fish transforming can improve rice growth are still unknown. Here, we conducted two field experiments to address these questions. One was to investigate the pattern of fish activity in the field using the method of video recording. The other was to examine the utilization of field resources by fish using stable isotope technology. Rice growth and rice yield were also exa-mined. Results showed that fish tended to be more active and significantly expanded the activity range in the rice-fish coculture compared to fish monoculture (fish not living together with rice plants). The contributions of 3 potential aquatic organisms (duckweed, phytoplankton and snail) to fish dietary were 22.7%, 34.8% and 30.0% respectively under rice-fish coculture without feed. Under the treatment with feed, however, the contributions of these 3 aquatic organisms to the fish die-tary were 8.9%, 5.9% and 1.6% respectively. The feed contribution was 71.0%. Rice-fish coculture significantly increased the nitrogen concentration in rice leaves, prolonged tillering stage by 10-12 days and increased rice spike rate and yield. The results suggested that raising fish in paddy field may transform the nutrients contained in field resources to bioavailable for rice plants through fish feeding activity, which can improve rice growth and rice yield.

Can north american fish passage tools work for South american migratory fishes?

Directory of Open Access Journals (Sweden)

Claudio Rafael Mariano Baigún

Full Text Available In North America, the Numerical Fish Surrogate (NFS is used to design fish bypass systems for emigrating juvenile salmon as they migrate from hatchery outfalls and rearing habitats to adult habitat in the oceans. The NFS is constructed of three linked modules: 1 a computational fluid dynamics model describes the complex flow fields upstream of dams at a scale sufficiently resolved to analyze, understand and forecast fish movement, 2 a particle tracking model interpolates hydraulic information from the fixed nodes of the computational fluid model mesh to multiple locations relevant to migrating fish, and 3 a behavior model simulates the cognition and behavior of individual fish in response to the fluid dynamics predicted by the computational fluid dynamics model. These three modules together create a virtual reality where virtual fish exhibit realistic dam approach behaviors and can be counted at dam exits in ways similar to the real world. Once calibrated and validated with measured fish movement and passage data, the NFS can accurately predict fish passage proportions with sufficient precision to allow engineers to select one optimum alternative from among many competing structural or operational bypass alternatives. Although South American fish species are different from North American species, it is likely that the basic computational architecture and numerical methods of the NFS can be used for fish conservation in South America. Consequently, the extensive investment made in the creation of the NFS need not be duplicated in South America. However, its use in South America will require that the behavioral response of the continent's unique fishes to hydrodynamic cues must be described, codified and tested before the NFS can be used to conserve fishes by helping design efficient South American bypass systems. To this end, we identify studies that could be used to describe the movement behavior of South American fishes of sufficient detail

Fish eye optics

Science.gov (United States)

Hudec, R.; Michalova, S.

2017-07-01

We report on small student (high—school) project of the Czech Academy of Sciences dealing with animal (fish) eyes and possible application in science and technology. Albeit most fishes have refractive eyes, the recent discoveries confirm that some fishes have reflective eyes with strange arrangements as well.

Anadromous fish behaviour important for fish passage

International Nuclear Information System (INIS)

Kynard, B.E.

1993-01-01

An understanding of the behavior of target fish species is necessary for proper design, location, and operation of a successful upstream or downstream fishway for anadromous migrants. Important fish behaviors are seasonal and daily timing of migration; rheotaxis and near field behavior; stimulus-response behavior; swimming capability; shoaling behavior; response to physical environmental factors such as illumination, sound, water depth, current velocity, and structure; response to chemicals; and response to biological factors such as competition for space and response to predators. The information on migrant fish behavior is reviewed, using examples from the literature on the behavior of eastern anadromous species, particularly Atlantic salmon (Salmo salar) and American shad (Alosa sapidissima). 87 refs

Recombinant fish parvalbumins: Candidates for diagnosis and treatment of fish allergy.

Science.gov (United States)

Swoboda, Ines; Bugajska-Schretter, A; Valenta, R; Spitzauer, S

2002-01-01

Fish and fish products represent one of the most important causes of IgE-mediated food hypersensitivity. In sensitized individuals contact with and consumption of fish can lead to severe health problems, ranging from urticaria and dermatitis to angiedema, diarrhoea, asthma and, at worst, systemic anaphylactic reactions and death. Parvalbumin, a small calcium-binding protein present in the muscles of vertebrates, was identified as the major fish allergen. We describe the isolation and characterization of cDNA clones coding for carp parvalbumin by IgE immunoscreening of a carp muscle expression library. These clones will be the basis for the production of recombinant carp parvalbumin, a useful tool for in vitro and in vivo diagnosis of fish allergy.

Selectivity of fish ladders: a bottleneck in Neotropical fish movement

Directory of Open Access Journals (Sweden)

Carlos Sérgio Agostinho

Full Text Available Although dozens of fish ladders have been constructed at dams of Brazilian reservoirs, there are few studies evaluating their efficiency as a tool for the conservation of Neotropical ichthyofauna, especially for migratory species. Therefore, the present study evaluated the selectivity of the species that entered and ascended the fish ladder located next to Lajeado Dam (Luis Eduardo Magalhães Hydroelectric Power Plant on the Tocantins River. Samples were taken monthly from November, 2002 through October, 2003, in the resting pools of the ladder, using cast nets, and in the downstream stretch, using gillnets. The selectivity of the ladder in attracting fish was evaluated by comparing the occurrence, relative abundance, dominance and the congruence of abundance ranks of migratory and non-migratory species in the ladder and in the stretch of river immediately downstream. Species richness and fish abundance in the resting pools were used to evaluate selectivity along the ladder. The effects on selectivity by temporal variations in water level downriver and maximum flow velocity in the fish ladder were also analyzed. Out of the 130 species recorded downriver, 62.3% were caught in the ladder, and migratory species were clearly favored. However, more than 2/3 of the catch belonged to only three species (Rhaphiodon vulpinus, Psectrogaster amazonica and Oxydoras niger. Although the majority of the species that entered the ladder were able to reach its top, there was a sharp reduction in abundance of individuals towards the top. Temporal variations in the water level below the dam influenced richness and abundance of fish concentrated downstream and in the ladder, with lower values during periods of low water. In the ladder, a maximum flow velocity of 2.3 m/s, although also selective, proved to be more appropriate for fish ascension than a velocity of 2.8 m/s. It was concluded that the entry and ascension of the fish in the ladder were not congruent with

Fish-T1K (Transcriptomes of 1,000 Fishes) Project: large-scale transcriptome data for fish evolution studies.

Science.gov (United States)

Sun, Ying; Huang, Yu; Li, Xiaofeng; Baldwin, Carole C; Zhou, Zhuocheng; Yan, Zhixiang; Crandall, Keith A; Zhang, Yong; Zhao, Xiaomeng; Wang, Min; Wong, Alex; Fang, Chao; Zhang, Xinhui; Huang, Hai; Lopez, Jose V; Kilfoyle, Kirk; Zhang, Yong; Ortí, Guillermo; Venkatesh, Byrappa; Shi, Qiong

2016-01-01

Ray-finned fishes (Actinopterygii) represent more than 50 % of extant vertebrates and are of great evolutionary, ecologic and economic significance, but they are relatively underrepresented in 'omics studies. Increased availability of transcriptome data for these species will allow researchers to better understand changes in gene expression, and to carry out functional analyses. An international project known as the "Transcriptomes of 1,000 Fishes" (Fish-T1K) project has been established to generate RNA-seq transcriptome sequences for 1,000 diverse species of ray-finned fishes. The first phase of this project has produced transcriptomes from more than 180 ray-finned fishes, representing 142 species and covering 51 orders and 109 families. Here we provide an overview of the goals of this project and the work done so far.

'Fish matters': the relevance of fish skin biology to investigative dermatology.

Science.gov (United States)

Rakers, Sebastian; Gebert, Marina; Uppalapati, Sai; Meyer, Wilfried; Maderson, Paul; Sell, Anne F; Kruse, Charli; Paus, Ralf

2010-04-01

Fish skin is a multi-purpose tissue that serves numerous vital functions including chemical and physical protection, sensory activity, behavioural purposes or hormone metabolism. Further, it is an important first-line defense system against pathogens, as fish are continuously exposed to multiple microbial challenges in their aquatic habitat. Fish skin excels in highly developed antimicrobial features, many of which have been preserved throughout evolution, and infection defense principles employed by piscine skin are still operative in human skin. This review argues that it is both rewarding and important for investigative dermatologists to revive their interest in fish skin biology, as it provides insights into numerous fundamental issues that are of major relevance to mammalian skin. The basic molecular insights provided by zebrafish in vivo-genomics for genetic, regeneration and melanoma research, the complex antimicrobial defense systems of fish skin and the molecular controls of melanocyte stem cells are just some of the fascinating examples that illustrate the multiple potential uses of fish skin models in investigative dermatology. We synthesize the essentials of fish skin biology and highlight selected aspects that are of particular comparative interest to basic and clinically applied human skin research.

Fish allergens at a glance: variable allergenicity of parvalbumins, the major fish allergens.

Science.gov (United States)

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

2014-01-01

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

Fish allergens at a glance: Variable allergenicity of parvalbumins, the major fish allergens

Directory of Open Access Journals (Sweden)

Annette eKuehn

2014-04-01

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

Perceptions of recreational fishing boat captains: knowledge and effects of fish consumption advisories.

Science.gov (United States)

Burger, J; Johnson, B B; Shukla, S; Gochfeld, M

2003-04-01

The impacts of fish consumption advisories on recreational and subsistence fishing, particularly in fresh waters, have been examined extensively. By contrast, little attention has focused on organized recreational fishing, such as from party and charter boats, and particularly for salt water fish. We interviewed 93 New Jersey boat captains to determine their knowledge about fish consumption advisories, and whether, in their opinion, clients knew of fish consumption advisories, and whether they thought advisories had an effect on recreational fishing and their businesses. Advisories were ranked by captains as a moderate influence on the success of their business, less so than number of fish caught, strength of the economy, overfishing by commercial boats, and management regulations. Only one boat captain had not heard warnings about eating fish, but what captains said they had heard was mixed in its accuracy and completeness. Clients expect captains to know about fish, and about half of boat captains said clients had asked about the safety of eating fish. Captains who felt advisories were affecting their businesses tended to fish for species without high levels of mercury (except for bluefish) or PCBs, the primary contaminants of concern for state advisories and federal advice. However, these captains worked closer to areas (e.g., Raritan Bay complex and New York Harbor) subject to advisories than did other captains, and were more prone to say that management regulations (e.g., fish size, creel limits, seasons) and marketing and advertising by the industry or state were strong influences on the success of their seasons. Comparing captains who thought advisories had some or great effect (60%) versus those reporting "no effect" (40%), there was no difference in the mean percentage of trips targeting high mercury species such as swordfish and shark. Many captains said they would or might post advisories, but 42% of the boat captains said they would not post consumption

Duration of pregnancy in relation to fish oil supplementation and habitual fish intake: a randomised clinical trial with fish oil

DEFF Research Database (Denmark)

Olsen, Sjurdur Frodi; Østerdal, M L; Salvig, J D

2007-01-01

OBJECTIVE: To examine the effect of fish oil supplementation on duration of pregnancy, conditional on the woman's habitual fish intake. DESIGN: Multicentre 1:1 randomised clinical trial of effect of fish oil in a high-risk population of pregnant women in whom habitual fish intake was assessed...... at randomisation. SETTING: Nineteen university delivery wards in seven European countries. SUBJECTS: Pregnant women with preterm delivery, intrauterine growth retardation (IUGR), or pregnancy-induced hypertension (PIH) in a previous pregnancy (group 1, n=495); with twin pregnancies (group 2, n=367......); or with suspicion of IUGR or threatening preeclampsia in the current pregnancy (group 3, n=106). Women were stratified into low, middle, or high fish consumers. METHODS: The intervention group received fish oil capsules providing 2.7 g long-chain n-3 fatty acids per day (n-3 poly unsaturated fatty acids (PUFA...

Habitat degradation and fishing effects on the size structure of coral reef fish communities.

Science.gov (United States)

Wilson, S K; Fisher, R; Pratchett, M S; Graham, N A J; Dulvy, N K; Turner, R A; Cakacaka, A; Polunin, N V C

2010-03-01

Overfishing and habitat degradation through climate change pose the greatest threats to sustainability of marine resources on coral reefs. We examined how changes in fishing pressure and benthic habitat composition influenced the size spectra of island-scale reef fish communities in Lau, Fiji. Between 2000 and 2006 fishing pressure declined in the Lau Islands due to declining human populations and reduced demand for fresh fish. At the same time, coral cover declined and fine-scale architectural complexity eroded due to coral bleaching and outbreaks of crown-of-thorns starfish, Acanthaster planci. We examined the size distribution of reef fish communities using size spectra analysis, the linearized relationship between abundance and body size class. Spatial variation in fishing pressure accounted for 31% of the variation in the slope of the size spectra in 2000, higher fishing pressure being associated with a steeper slope, which is indicative of fewer large-bodied fish and/or more small-bodied fish. Conversely, in 2006 spatial variation in habitat explained 53% of the variation in the size spectra slopes, and the relationship with fishing pressure was much weaker (approximately 12% of variation) than in 2000. Reduced cover of corals and lower structural complexity was associated with less steep size spectra slopes, primarily due to reduced abundance of fish < 20 cm. Habitat degradation will compound effects of fishing on coral reefs as increased fishing reduces large-bodied target species, while habitat loss results in fewer small-bodied juveniles and prey that replenish stocks and provide dietary resources for predatory target species. Effective management of reef resources therefore depends on both reducing fishing pressure and maintaining processes that encourage rapid recovery of coral habitat.

Intelligent Fish Freshness Assessment

Directory of Open Access Journals (Sweden)

Hamid Gholam Hosseini

2008-01-01

Full Text Available Fish species identification and automated fish freshness assessment play important roles in fishery industry applications. This paper describes a method based on support vector machines (SVMs to improve the performance of fish identification systems. The result is used for the assessment of fish freshness using artificial neural network (ANN. Identification of the fish species involves processing of the images of fish. The most efficient features were extracted and combined with the down-sampled version of the images to create a 1D input vector. Max-Win algorithm applied to the SVM-based classifiers has enhanced the reliability of sorting to 96.46%. The realisation of Cyranose 320 Electronic nose (E-nose, in order to evaluate the fish freshness in real-time, is experimented. Intelligent processing of the sensor patterns involves the use of a dedicated ANN for each species under study. The best estimation of freshness was provided by the most sensitive sensors. Data was collected from four selected species of fishes over a period of ten days. It was concluded that the performance can be increased using individual trained ANN for each specie. The proposed system has been successful in identifying the number of days after catching the fish with an accuracy of up to 91%.

Why fishing magnifies fluctuations in fish abundance.

Science.gov (United States)

Anderson, Christian N K; Hsieh, Chih-hao; Sandin, Stuart A; Hewitt, Roger; Hollowed, Anne; Beddington, John; May, Robert M; Sugihara, George

2008-04-17

It is now clear that fished populations can fluctuate more than unharvested stocks. However, it is not clear why. Here we distinguish among three major competing mechanisms for this phenomenon, by using the 50-year California Cooperative Oceanic Fisheries Investigations (CalCOFI) larval fish record. First, variable fishing pressure directly increases variability in exploited populations. Second, commercial fishing can decrease the average body size and age of a stock, causing the truncated population to track environmental fluctuations directly. Third, age-truncated or juvenescent populations have increasingly unstable population dynamics because of changing demographic parameters such as intrinsic growth rates. We find no evidence for the first hypothesis, limited evidence for the second and strong evidence for the third. Therefore, in California Current fisheries, increased temporal variability in the population does not arise from variable exploitation, nor does it reflect direct environmental tracking. More fundamentally, it arises from increased instability in dynamics. This finding has implications for resource management as an empirical example of how selective harvesting can alter the basic dynamics of exploited populations, and lead to unstable booms and busts that can precede systematic declines in stock levels.

Augmented fish health monitoring

International Nuclear Information System (INIS)

Michak, P.; Rogers, R.; Amos, K.

1991-05-01

The Bonneville Power Administration (BPA) initiated the Augmented Fish Health Monitoring project in 1986. This project was a five year interagency project involving fish rearing agencies in the Columbia Basin. Historically, all agencies involved with fish health in the Columbia Basin were conducting various levels of fish health monitoring, pathogen screening and collection. The goals of this project were; to identify, develop and implement a standardized level of fish health methodologies, develop a common data collection and reporting format in the area of artificial production, evaluate and monitor water quality, improve communications between agencies and provide annual evaluation of fish health information for production of healthier smolts. This completion report will contain a project evaluation, review of the goals of the project, evaluation of the specific fish health analyses, an overview of highlights of the project and concluding remarks. 8 refs., 1 fig., 4 tabs

Monitoring of heavy metals in marine and freshwater fishes and nutritional evaluation of fish consumption

International Nuclear Information System (INIS)

Rina Mulyaningsih

2014-01-01

Fish is a food source of minerals. Uptake of heavy metals in fish could come from water, sediment and fish feed. Monitoring of minerals content and contaminants in fish has been carried out to evaluate nutrition and food safety, using neutron activation analysis techniques. Marine fish species that being analyzed are Kembung (Rastrelliger faughni), mackerel (Acanthocybium solandri), Tuna (Authis thazard) and freshwater fishes are Bawal (Colossoma macropomum), Nila (Oreochromis niloticus), Mas (Cyprinus carpio), sampled from 6 markets in North Jakarta. Monitoring results indicate that the essential minerals contained in fish are Fe, K, Na, Zn, Ca, Mg, and Se. Se and Ca concentrations in marine fish are higher than in freshwater fish. The concentration of other essential elements varies depending on the type of fish. The concentration of arsenic in marine fish is 3 times higher than that of freshwater fish; Hg and Cr content in all fish species were observed. From the evaluation of the adequacy of nutrition, with assuming a consumption of 86.68 g fish/day, for men aged 19 - 30 years, and referring to data from the Institute of Medicine USA, the Ca intake : 2.5 - 6.3; Cl : 1.5 - 3.3; Fe : 11.5 - 26.9; Na : 1.5 - 4.1; K : 3.4 - 6.7 and Zn 3.9 - 7.2% of the recommended value. Cr intake exceeds the recommended value, while As and Hg is not recommended in the food. In fact these metals contained in the studied fish, but the concentration is still below the value of standards issued by BPOM. (author)

A Study of Fish Lice (Argulus Sp.) Infection in Freshwater Food Fish

OpenAIRE

Aalberg K.; Koščová L.; Šmiga Ľ.; Košuth P.; Koščo J.; Oros M.; Barčák D.; Lazar P.

2016-01-01

Argulus sp., commonly referred to as fish lice, are crustacean ectoparasites of fishes. The hematophagous parasites attach to and feed off the integument of their hosts. Outbreaks of epizootics have been reported worldwide, causing mass mortalities and having serious economic implications for fish farms and culture efforts. Argulus fish lice may also serve as vectors of infectious diseases and as intermediate hosts of other parasites. Two native European species, A. foliaceus and A. coregoni,...

BIOTECHNOLOGY OF THE FISH AQUACULTURE

Directory of Open Access Journals (Sweden)

L. P. Buchatsky

2013-12-01

Full Text Available The latest progress in biotechnology on fish aquaculture and different modern methods of investigations for increasing of fish productivity in aquaculture are analyzed. Except for the applied aspect, the use of modern biotechnological methods of investigations opens new possibilities for fundamental researches of sex-determining mechanisms, polyploidy, distant hybridization, and developmental biology of bony fishes. Review contains examples of utilizing modern biotechnology methods to obtain transgenic fishes with accelerated growth and for designing surrogate fishes. Methods for receiving unisexual shoals of salmon and sturgeon female fishes with the view of obtaining a large quantity of caviar, as well as receiving sterile (triploid fishes are analyzed. Great attention is given to androgenesis, particularly to disperm one, in connection with the problem of conserving rare and vanishing fish species using only sperm genetic material. Examples how distant hybrids may be obtained with the use of disperm androgenesis and alkylated DNA are given. Methods of obtaining fish primordium germ cells, recent developments in cultivation of fish stem cells and their use in biotechnology, as well as ones of transplantation of oogonium and spermatogonium to obtain surrogate fishes. The examples of successful experiments on spermatogonial xenotransplantation and characteristic of antifreezing fish proteins and also the prospect of their practical usage are given.

Trophic pathways supporting Arctic grayling in a small stream on the Arctic Coastal Plain, Alaska

Science.gov (United States)

McFarland, Jason J.; Wipfli, Mark S.; Whitman, Matthew S.

2018-01-01

Beaded streams are prominent across the Arctic Coastal Plain (ACP) of Alaska, yet prey flow and food web dynamics supporting fish inhabiting these streams are poorly understood. Arctic grayling (Thymallus arcticus) are a widely distributed upper-level consumer on the ACP and migrate into beaded streams to forage during the short 3-month open-water season. We investigated energy pathways and key prey resources that support grayling in a representative beaded stream, Crea Creek. We measured terrestrial invertebrates entering the stream from predominant riparian vegetation types, prey types supporting a range of fish size classes, and how riparian plants and fish size influenced foraging habits. We found that riparian plants influenced the quantity of terrestrial invertebrates entering Crea Creek; however, these differences were not reflected in fish diets. Prey type and size ingested varied with grayling size and season. Small grayling (15 cm FL) foraged most heavily on ninespine stickleback (Pungitius pungitius) throughout the summer, indicating that grayling can be insectivorous and piscivorous, depending on size. These findings underscore the potential importance of small streams in Arctic ecosystems as key summer foraging habitats for fish. Understanding trophic pathways supporting stream fishes in these systems will help interpret whether and how petroleum development and climate change may affect energy flow and stream productivity, terrestrial–aquatic linkages and fishes in Arctic ecosystems.

Enzymes in Fermented Fish.

Science.gov (United States)

Giyatmi; Irianto, H E

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

Bibliographic review of works accomplished about irradiated chicken, fish and fish products , spices and condiments

International Nuclear Information System (INIS)

Bernardes, B.; Dias Filho, M.

1983-07-01

Table of foods that can be irradiated and its respective nominal doses are shown. Bibliographic reviews of works performed about irradiated chicken, fish and fish products, spices and condiments are shown. The irradiation purpose in chicken were to increase the shelf-life and to eliminate the pathogenic microorganism in chicken stored below 10 0 C; in fish and fish products the purposes were to control the insect infestation in dry-fish during the storage and the sell exposure to reduce the macrobian charge in packed and non packed fish and in fish products. To reduce pathogenic microorganism in packing and unpacking fish; in spices and condiments to control the insect infestation, to reduce the microbial contamination. (L.M.J.)

Benzo[a]pyrene and Benzo[k]fluoranthene in Some Processed Fish and Fish Products

Directory of Open Access Journals (Sweden)

Olatunde S. Olatunji

2015-01-01

Full Text Available In this study, the concentration levels of the probable carcinogenic PAH fractions, benzo[a]pyrene (BaP and benzo[k]fluoranthrene (BkF in fillets of some processed fish species were investigated. Fish species comprising Merluccius poli (hake, Tyrsites atun (snoek, Seriola lalandi (yellow-tail and Brama brama (angel fish were bought in fish shops at Gordon’s Bay, Western Cape, South Africa. The fish were gutted, filleted and prepared for edibility by frying, grilling and boiling. Polycyclic aromatic hydrocarbons were extracted from each homogenized fish sample, cleaned-up using solid phase extraction (SPE, and analysed for the PAH fractions, BaP and BkF using a Gas Chromatograph coupled with a Flame Ionization Detector (GC-FID. The sum of the two PAHs (∑2PAH i.e., BaP and BkF ranged between 0.56 and 1.46 µg/kg, in all boiled, grilled and fried fish species. The fried fish extracts showed significantly higher (p < 0.05 abundance of ∑2PAH, than grilled and boiled fish. Dietary safety and PAHs toxicity was also discussed.

Fish allergy in childhood.

Science.gov (United States)

Pascual, Cristina Y; Reche, Marta; Fiandor, Ana; Valbuena, Teresa; Cuevas, Teresa; Esteban, Manuel Martin

2008-11-01

Fish and its derived products play an important role in human nutrition, but they may also be a potent food allergen. Fish can be an ingested, contact, and inhalant allergen. Gad c I, a Parvalbumin, the major allergen in codfish, is considered as fish and amphibian pan-allergen. Prevalence of fish allergy appears to depend on the amount of fish eaten in the local diet. In Europe, the highest consumption occurs in Scandinavian countries, Spain and Portugal. In Spain, fish is the third most frequent allergen in children under 2 yr of age after egg and cow's milk. An adverse reaction to fish may be of non-allergic origin, due to food contamination or newly formed toxic products, but the most frequent type of adverse reactions to fish are immunologic-mediated reactions (allergic reactions). Such allergic reactions may be both IgE-mediated and non-IgE-mediated. Most cases are IgE-mediated, due to ingestion or contact with fish or as a result of inhalation of cooking vapors. Some children develop non-IgE-mediated type allergies such as food protein induced enterocolitis syndrome. The clinical symptoms related to IgE-mediated fish allergy are most frequently acute urticaria and angioedema as well as mild oral symptoms, worsening of atopic dermatitis, respiratory symptoms such as rhinitis or asthma, and gastrointestinal symptoms such as nausea and vomiting. Anaphylaxis may also occur. Among all the species studied, those from the Tunidae and Xiphiidae families appear to be the least allergenic.

FISH and PNA FISH for the diagnosis of Q fever endocarditis and vascular infections.

Science.gov (United States)

Prudent, Elsa; Lepidi, Hubert; Angelakis, Emmanouil; Raoult, Didier

2018-06-13

Purpose. Endocarditis and vascular infections are common manifestations of persistent localized infection due to Coxiella burnetii and recently, fluorescence in situ hybridization (FISH) was proposed as an alternative tool for their diagnosis. In this study, we evaluated the efficiency of FISH in a series of valve and vascular samples infected by C. burnetii. Methods. We tested 23 C. burnetii -positive valves and thrombus samples obtained from patients with Q fever endocarditis. Seven aneurysms and thrombus specimens were retrieved from patients with Q fever vascular infection. Samples were analyzed by culture, immunochemistry and FISH with oligonucleotide and PNA probes targeting C. burnetii -specific 16S ribosomal RNA sequences. Results. Immunohistochemical analysis was positive for five (17%) samples with significantly more copies of C. burnetii DNA than the negative ones ( p= 0.02). FISH was positive for 13 (43%) samples and presented 43% and 40% sensitivity compared to qPCR and culture, respectively. PNA FISH detected C. burnetii in 18 (60%) samples and presented 60% and 55% sensitivity compared to qPCR and culture, respectively. Immunohistochemistry had 38% and 28% sensitivity compared to FISH and PNA FISH, respectively. Samples found positive by both immunohistochemistry and PNA FISH contained significantly more copies of C. burnetii DNA than the negative ones ( p= 0.03). Finally, PNA FISH was more sensitive than FISH (60% versus 43%) for the detection of C. burnetii Conclusion. We provide evidence that PNA FISH and FISH are important assays for the diagnosis of C. burnetii endocarditis and vascular infections. Copyright © 2018 American Society for Microbiology.

Fish mucus metabolome reveals fish life-history traits

Science.gov (United States)

Reverter, M.; Sasal, P.; Banaigs, B.; Lecchini, D.; Lecellier, G.; Tapissier-Bontemps, N.

2017-06-01

Fish mucus has important biological and ecological roles such as defense against fish pathogens and chemical mediation among several species. A non-targeted liquid chromatography-mass spectrometry metabolomic approach was developed to study gill mucus of eight butterflyfish species in Moorea (French Polynesia), and the influence of several fish traits (geographic site and reef habitat, species taxonomy, phylogeny, diet and parasitism levels) on the metabolic variability was investigated. A biphasic extraction yielding two fractions (polar and apolar) was used. Fish diet (obligate corallivorous, facultative corallivorous or omnivorous) arose as the main driver of the metabolic differences in the gill mucus in both fractions, accounting for 23% of the observed metabolic variability in the apolar fraction and 13% in the polar fraction. A partial least squares discriminant analysis allowed us to identify the metabolites (variable important in projection, VIP) driving the differences between fish with different diets (obligate corallivores, facultative corallivores and omnivorous). Using accurate mass data and fragmentation data, we identified some of these VIP as glycerophosphocholines, ceramides and fatty acids. Level of monogenean gill parasites was the second most important factor shaping the gill mucus metabolome, and it explained 10% of the metabolic variability in the polar fraction and 5% in the apolar fraction. A multiple regression tree revealed that the metabolic variability due to parasitism in the polar fraction was mainly due to differences between non-parasitized and parasitized fish. Phylogeny and butterflyfish species were factors contributing significantly to the metabolic variability of the apolar fraction (10 and 3%, respectively) but had a less pronounced effect in the polar fraction. Finally, geographic site and reef habitat of butterflyfish species did not influence the gill mucus metabolome of butterflyfishes.

Detection and identification of globally distributed mycobacterial fish pathogens in some ornamental fish in India.

Science.gov (United States)

Shukla, Shubhra; Sharma, Rolee; Shukla, Sanjeev Kumar

2013-09-01

Mycobacteriosis is a progressive disease of a wide range of wild and captive, marine and freshwater fish species. Conventional detection of fish Mycobacteria is based on histopathology, culture, and biochemical characteristics. The present study analyzed the occurrence of Mycobacteria in clinically ill ornamental fish of different species, from different places of India. In first group, 60 fish were examined for presence of granulomatous inflammation and acid-fast bacteria. Thirty-eight (63.34 %) fish were positive for granulomatous inflammations. Presences of acid-fast bacteria were detected in 27 (45 %) fish having granulomatous inflammation and in two (3.33 %) fish without granulomatous inflammation. In total, AFB were found in 29 (48.34 %) of the 60 fish examined. In second group, 20 fish having granulomatous inflammation, 12 (60 %) samples were positive using Ziehl-Neelsen (Z-N) staining and 11 (55 %) of them were culture positive. Eight (40 %) samples were Z-N negative but two (10 %) of them were culture positive. In total, 13 (65 %) of the 20 examined fish were culture positive. On the basis of biochemical tests and 16S rRNA sequencing, 13 isolates were identified: five as Mycobacterium fortuitum, five as Mycobacterium gordonae, and three as Mycobacterium chelonae. In comparison of two decontamination methods, 2 % HCl treatment was better than 4 % NaOH treatment. Mycobacteria recovery from decontaminated samples was significantly high on Lowenstein-Jensen medium compared to Middlebrook 7H11 agar and Stonebrink (SB) media. The disease is transmissible from fish to fish and also from fish to human, so the significance of Mycobacteria in ornamental fish should not be overlooked.

Immunostimulants in fish diets

Science.gov (United States)

Gannam, A.L.; Schrock, R.M.

1999-01-01

Various immunostimulants and their methods of application in fish culture are examined in this review. Important variables such as life stage and innate disease resistance of the fish; immunostimulant used, its structure and mode of action; and the fish's environment are discussed. Conflicting results have been published about the efficacy of immunostimulants in fish diets. Some researchers have had positive responses demonstrated as increased fish survival, others have not. Generally, immunostimulants enhance individual components of the non-specific immune response but that does not always translate into increased fish survival. In addition, immunostimulants fed at too high a dose or for too long can be immunosuppressive. [Article copies available for a fee from The Haworth Document Delivery Service: 1-800-342-9678. E-mail address: getinfo@haworthpressinc.com ].

Fish and hydroelectricity

International Nuclear Information System (INIS)

Zorpette, G.

1990-01-01

This paper reports on the problems that hydroelectric plants have regarding fish populations. The utilities that operate these plants are finding that accommodating migrating fish presents unique engineering challenges, not the least of which involves designing and building systems to protect fish species whose migratory behavior remains something of a mystery. Where such systems cannot be built, the status of hydroelectric dams may be in doubt, as is now the case with several dams in the United States. A further twist in some regions in the possibility that certain migratory fish will be declared threatened or endangered-a development that could wreak havoc on the hydroelectric energy supply in those regions

Fish impingement at estuarine power stations and its significance to commercial fishing

International Nuclear Information System (INIS)

Turnpenny, A.W.H.

1989-01-01

The abstraction of cooling water (CW) at power stations sited on tidal waters inevitably leads to mortalities of some fish which are drawn in with the CW supply and become impinged on the intake screens. These fish are predominantly 0- or 1-group juveniles which, owing to their small size, are unable to resist intake currents. Commercial fishermen often object to the fact that juvenile fish are killed in this way. Their concern stems from the fact that in order to protect stocks, commercial fishing is restricted to fish which are above a statutory minimum landing size, whereas the majority of fish killed by impingement are below this size. This Report considers the significance of impingement mortalities at four estuarine sites in Britain for six commercially important species. Life tables are used to establish expected survival trajectories for each species and to compute reproductive potential. Each fish killed on intake screens is then considered in terms of the fraction of the reproductive potential of a single adult at maturity, and is ascribed an 'adult equivalent' value. Total catches of mixed juveniles and adults are then presented as 'adult equivalent' values. (author)

Emerging role of phenolic compounds as natural food additives in fish and fish products.

Science.gov (United States)

Maqsood, Sajid; Benjakul, Soottawat; Shahidi, Fereidoon

2013-01-01

Chemical and microbiological deteriorations are principal causes of quality loss of fish and fish products during handling, processing, and storage. Development of rancid odor and unpleasant flavor, changes of color and texture as well as lowering nutritional value in fish can be prevented by appropriate use of additives. Due to the potential health hazards of synthetic additives, natural products, especially antioxidants and antimicrobial agents, have been intensively examined as safe alternatives to synthetic compounds. Polyphenols (PP) are the natural antioxidants prevalent in fruits, vegetables, beverages (tea, wine, juices), plants, seaweeds, and some herbs and show antioxidative and antimicrobial activities in different fish and fish products. The use of phenolic compounds also appears to be a good alternative for sulphiting agent for retarding melanosis in crustaceans. Phenolic compounds have also been successfully employed as the processing aid for texture modification of fish mince and surimi. Thus, plant polyphenolic compounds can serve as potential additives for preventing quality deterioration or to retain the quality of fish and fish products.

Improving fish survival through turbines

International Nuclear Information System (INIS)

Ferguson, J.W.

1993-01-01

Much of what is known about fish passage through hydroturbines has been developed by studying migratory species of fish passing through large Kaplan turbine units. A review of the literature on previous fish passage research presented in the accompanying story illustrates that studies have focused on determining mortality levels, rather than identifying the causal mechanism involved. There is a need for understanding how turbine designs could be altered to improve fish passage conditions, how to retrofit existing units, and how proposed hydro plant operational changes may affect fish survival. The US Army Corps of Engineers has developed a research program to define biologically based engineering criteria for improving fish passage conditions. Turbine designs incorporating these criteria can be evaluated for their effects on fish survival, engineering issues, costs, and power production. The research program has the following objectives: To gain a thorough knowledge of the mechanisms of fish mortality; To define the biological sensitivities of key fish species to these mechanisms of mortality; To develop new turbine design criteria to reduce fish mortality; To construct prototype turbine designs, and to test these designs for fish passage, hydro-mechanical operation, and power production; and To identify construction and power costs associated with new turbine designs

Persistent Organohalogens in Paired Fish Fillet and Eggs: Implications for Fish Consumption Advisories.

Science.gov (United States)

Zhang, Xianming; Gandhi, Nilima; Bhavsar, Satyendra P

2016-04-13

Fish consumption is associated with both health benefits from high-quality proteins, minerals, vitamins, and fatty acids and risks from contaminants in fish. Fish consumption advisories are issued by many government agencies to keep exposure to contaminants at a safe level. Such advisories are typically based on fillets and neglect consumption of other fish parts such as eggs by certain subpopulations. To evaluate potential for dietary exposure to toxic organic chemicals via fish eggs, we analyzed polybrominated diphenyl ethers (PBDEs), polychlorinated naphthalenes (PCNs), dioxin-like polychlorinated biphenyls (dlPCBs), and polychlorinated dibenzodioxins/furans (PCDD/Fs) in paired fillet and eggs of fish from a tributary to Lake Ontario, one of the North American Great Lakes. All wet weight based concentrations in fish eggs were statistically higher than in the paired fillet samples. In fish eggs, concentrations of Σ14PBDEs, Σ14PCNs, and Σ12dlPCBs were 41-118, 0.3-1.7, and 30-128 ng/g wet weight (ww), respectively; Σ3PCDD/Fs and total (dlPCB+ PCDD/Fs) toxic equivalents (TEQs) were 4-22 and 9-54 pg/g ww, respectively. In fillet samples, Σ14PBDEs, Σ14PCNs, and Σ12dlPCBs were 4-116, 0.05-0.66, and 6-85 ng/g, respectively; Σ3PCDD/Fs and TEQs were 2-10 and 3.4-31 pg/g ww, respectively. In contrast, the fillets had higher lipid normalized concentrations than the paired egg samples, suggesting that these chemicals did not reach equilibrium between the fillets and eggs. Accordingly, measured concentrations in eggs or empirical relationship with fillet rather than prediction from equilibrium partitioning model should be used to evaluate contaminant exposure via consumption of fish eggs. For fatty fish from the lower Great Lakes area, we suggest one fillet meal be reduced from the advised fish consumption frequency for consumptions of 207 ± 37, 39 ± 2, 105 ± 51, and 119 ± 9 g fish eggs of brown trout, Chinook salmon, Coho salmon, and rainbow trout, respectively.

Fishing effects on energy use by North Sea fishes

NARCIS (Netherlands)

Jennings, S.; Hal, van R.; Hiddink, J.G.; Maxwell, T.A.D.

2008-01-01

Fishing affects patterns of energy use in fish populations, as demonstrated by changes in population energy consumption and the size and age when energy demands are greatest. We compare theoretical predictions and observed patterns of energy use (expressed as the primary production required to

Infection dynamics of the monogenean parasite Gyrodactylus gasterostei on sympatric and allopatric populations of the three-spined stickleback Gasterosteus aculeatus.

Science.gov (United States)

Raeymaekers, Joost A M; Wegner, K Mathias; Huyset, Tine; Volckaert, Filip A M

2011-03-01

Parasites with high host specificity maximally depend on their hosts, which should increase the likelihood of coevolution. However, coevolution requires reciprocal selection exerted by the host and the parasite, and thus a considerable level of parasite virulence. In species of the monogenean ectoparasite genus Gyrodactylus consecutive generations are confronted with a single host, which may constrain the evolution of virulence. Transmission, which is often important in the ecology of Gyrodactylus species, may have the opposite effect, but may also lead to the avoidance of coevolutionary arms races. We investigated the potential outcome of coevolution between Gyrodactylus gasterostei Gläser, 1974 and its host, the three-spined stickleback (Gasterosteus aculeatus L.) by determining the strength of genotype by genotype (GxG) interactions on two levels: within and between sympatric and allopatric host populations. To do so, we compared the parasite's infection dynamics on laboratory-reared sympatric (Belgian) and allopatric (German) hosts. We found that a parasite line successfully infected a range of sympatric host genotypes (represented by families), while it failed to establish on allopatric hosts. Phylogeographic studies suggest that neutral genetic divergence between the host populations cannot explain this dramatic difference. Provided that this result can be generalised towards other parasite lines, we conclude that coevolution in this host-parasite system is more likely to lead to local adaptation on the population level than to GxG interactions within populations.

Multiple cues produced by a robotic fish modulate aggressive behaviour in Siamese fighting fishes.

Science.gov (United States)

Romano, Donato; Benelli, Giovanni; Donati, Elisa; Remorini, Damiano; Canale, Angelo; Stefanini, Cesare

2017-07-05

The use of robotics to establish social interactions between animals and robots, represents an elegant and innovative method to investigate animal behaviour. However, robots are still underused to investigate high complex and flexible behaviours, such as aggression. Here, Betta splendens was tested as model system to shed light on the effect of a robotic fish eliciting aggression. We evaluated how multiple signal systems, including a light stimulus, affect aggressive responses in B. splendens. Furthermore, we conducted experiments to estimate if aggressive responses were triggered by the biomimetic shape of fish replica, or whether any intruder object was effective as well. Male fishes showed longer and higher aggressive displays as puzzled stimuli from the fish replica increased. When the fish replica emitted its full sequence of cues, the intensity of aggression exceeded even that produced by real fish opponents. Fish replica shape was necessary for conspecific opponent perception, evoking significant aggressive responses. Overall, this study highlights that the efficacy of an artificial opponent eliciting aggressive behaviour in fish can be boosted by exposure to multiple signals. Optimizing the cue combination delivered by the robotic fish replica may be helpful to predict escalating levels of aggression.

Turbine related fish mortality

International Nuclear Information System (INIS)

Eicher, G.J.

1993-01-01

A literature review was conducted to assess the factors affecting turbine-related fish mortality. The mechanics of fish passage through a turbine is outlined, and various turbine related stresses are described, including pressure and shear effects, hydraulic head, turbine efficiency, and tailwater level. The methodologies used in determining the effects of fish passage are evaluated. The necessity of adequate controls in each test is noted. It is concluded that mortality is the result of several factors such as hardiness of study fish, fish size, concentrations of dissolved gases, and amounts of cavitation. Comparisons between Francis and Kaplan turbines indicate little difference in percent mortality. 27 refs., 5 figs

Immunity to Fish Rhabdoviruses

OpenAIRE

Purcell, Maureen K.; Laing, Kerry J.; Winton, James R.

2012-01-01

Members of the family Rhabdoviridae are single-stranded RNA viruses and globally important pathogens of wild and cultured fish and thus relatively well studied in their respective hosts or other model systems. Here, we review the protective immune mechanisms that fish mount in response to rhabdovirus infections. Teleost fish possess the principal components of innate and adaptive immunity found in other vertebrates. Neutralizing antibodies are critical for long-term protection from fish rhabd...

The prevalence of parasites in ornamental fish from fish market in Medan

Science.gov (United States)

Dewi, R. R.; Desrita; Fadhilla, A.

2018-02-01

Parasites still become the major problem in ornamental fish as the fast grown of its trading in Indonesia. Parasites causes diseases in ornamental fish hence followed by death and reducing its appearence. In this study, the prevalence of parasites in 100 apparently healthy ornamental fishes namely Guppy (Poecilia reticulate) and Goldfish (Carrasius auratus) were determined. The method of this research used was survey in local fish market in Medan from March to May 2017 The aim of this study was to determine the parasite that infects aquarium fishes and find out its prevalence. For this purpose, ornamental fishes were examined for parasites from their skin, fin, gill and intestine using wet mount method under a light microscope. The survey result showed that parasites that infect Guppy and Goldfish were Monogenea (Dactylogyrus sp and Gyrodactylus sp) in their skin and gill, Protozoa (piscinodinium sp) in their gill and Nematoda (Capillaria sp) in abdominal cavity. Prevalence rate of parasites that attack Guppy in Medan is Dactylogyrus sp (8%), Gyrodactylus sp (14 %), Piscinodinium sp (6%) and Capillaria sp (8%). Then, prevalence rate of Capilaria sp that attack Goldfish is 4%. The conclusion of this work revealed that the prevalence rate of ectoparasite and endoparasites in ornamental fishes in Medan had the low rate as well as there was no pathological findings is observed. However, these parasites could be a harmful parasitic diseases in case there is the changes in aquarium environment and improper fish handling.

Fish reproduction

National Research Council Canada - National Science Library

Rocha, Maria João; Arukwe, Augustine; Kapoor, B. G

2008-01-01

... of reproductive systems is essential for such studies. Fishes comprise over 28,000 species, with a remarkable variability in morphology, physiology and environmental adaptation. Knowledge on fish reproduction is scattered across numerous sources that shows a dynamic research field. The Editors believe it to be an opportune moment for a...

Monetary values of freshwater fish and fish-kill counting guidelines

National Research Council Canada - National Science Library

1982-01-01

.... The product is a set of documented monetary values of freshwater fish that may be used, in conjunction with standard sampling programs outlined in Part II of this book, to assess the value of fish...

Soluble protein isolated from low cost fish and fish wastes

OpenAIRE

Lekshmy Nair, A.; Gopakumar, K.

1982-01-01

The method of preparation, composition, amino acid content, protein efficiency ratio and areas of possible application of water soluble protein isolates from low cost fish and fish wastes are discussed in detail in this communication.

Quantifying relative fishing impact on fish populations based on spatio-temporal overlap of fishing effort and stock density

DEFF Research Database (Denmark)

Vinther, Morten; Eero, Margit

2013-01-01

Evaluations of the effects of management measures on fish populations are usually based on the analyses of population dynamics and estimates of fishing mortality from stock assessments. However, this approach may not be applicable in all cases, in particular for data-limited stocks, which may...... GAM analyses to predict local cod densities and combine this with spatio-temporal data of fishing effort based on VMS (Vessel Monitoring System). To quantify local fishing impact on the stock, retention probability of the gears is taken into account. The results indicate a substantial decline...... in the impact of the Danish demersal trawl fleet on cod in the Kattegat in recent years, due to a combination of closed areas, introduction of selective gears and changes in overall effort....

Technical Suitability and Static Stability of Sungkur Fishing Boats for Fish and Shrimp Catching

Science.gov (United States)

Rusmilyansari; Rosadi, E.; Iriansyah

2017-10-01

Sungkur fishing gear is operated actively on one the side of fishing boat, which requires technical suitability and fishing gear stability to ensure success in fish catching. This is a case study which aimed to analyze some technical issues related to the boat, boat’s hydrostatic parameters, and the boat’s stability. The data were collected though observation, measuring the boat to obtain the offset table. The data were analyzed numerically and descriptively. The data were processed with technical formula, Microsoft Office’s Excel software, graphic display, minitab, statistical data processing, and maxsurf program. The research results showed that: (1) the sungkur fishing boat dimensional ratio L/B (6.47 - 7.00); L/D (10.90 - 11.20) and B/D (1.60 - 1.668) is within the range value of Indonesian fishing boats suitable to operate the fishing gear by towing or dragging. However, during fish catching operation, there have been problems in a hydrodynamic force due to the fishing gear movement, which affect the fish catching efficiency. (2) The boat’s coefficient of fineness is in the fine type shape; the displacement on each waterline has increased; the loads of the boat are getting larger following the increase of waterline from one to five; this is also shown from the increasing midship area value. Ton per centimeter immersion to change wl 1 by 1 cm needs 0.04 tons of weight. (3) Sungkur fishing boat have a good static stability, which is proven by the positive value of angle of maximum GZ by 79.1 - 83.6. In other words, the boat has the ability to return to its original position after tilting; however, stability dynamics happens because fishing gear operation are located on just one side of boat.

Contaminants in popular farmed fish consumed in The Netherlands and their levels in fish feedContaminants in popular farmed fish consumed in The Netherlands and their levels in fish feed

NARCIS (Netherlands)

Leeuwen, van S.; Velzen, van M.; Swart, K.; Veen, van der I.; Traag, W.A.; Spanjer, M.; Scholten, J.; Rijn, van H.

2008-01-01

Investigated is a wide range of pollutants in the top five consumed fish in the Netherlands (salmon, trout, tilapia, pangasius and shrimps). Farmed fish samples were collected from different sources (supermarkets, fish stores, markets and suppliers for restaurants) and analysed for PCDD/Fs, PCBs,

Perspectives on fish impingement

International Nuclear Information System (INIS)

Sharma, R.K.

1977-01-01

Data on fish impingement and related parameters are being gathered at a large number of power stations throughout the country at substantial monetary and manpower costs. A national survey of fish impingement at power plants was conducted and much of the information compiled in a standardized format--an effort that we think will aid in planning improvements in the design, siting, and operation of the cooling-water intakes. This paper examines the objectives of the fish impingement studies, monitoring programs, variables affecting fish impingement, siting and design criteria, state-of-the-art of screening systems, and suggestions for meeting 316(b) requirements. It also discusses where the emphasis should be placed in future fish-impingement related activities

Fish and mussels: importance of fish for freshwater mussel conservation

Directory of Open Access Journals (Sweden)

Ronaldo Sousa

2015-12-01

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

Effect of Recreational Fish Feeding on Reef Fish Community ...

African Journals Online (AJOL)

... that the reaction to bread at feeding sites was quicker than at control sites, which indicates that some species learn to feed on this novel source of food. Keywords:human-animal interactions, reef fish, recreational fish feeding, tourism impacts, MPAs, coral reefs, Kenya West Indian Ocean Journal of Marine Science Vol.

Fish losses due to bacterial flora and infections of fishes in Kainji ...

African Journals Online (AJOL)

This paper assesses the losses incurred as a result of bacterial flora and infection in captured and cultured fish. The role played by these bacterial flora on the overall quality and health of fish is discussed. Bacteria have been reported to cause diseases in ponds and increase in the spoilage rate of raw and preserved fish in ...

Distance from a fishing community explains fish abundance in a no-take zone with weak compliance.

Science.gov (United States)

Advani, Sahir; Rix, Laura N; Aherne, Danielle M; Alwany, Magdy A; Bailey, David M

2015-01-01

There are numerous examples of no-take marine reserves effectively conserving fish stocks within their boundaries. However, no-take reserves can be rendered ineffective and turned into 'paper parks' through poor compliance and weak enforcement of reserve regulations. Long-term monitoring is thus essential to assess the effectiveness of marine reserves in meeting conservation and management objectives. This study documents the present state of the 15-year old no-take zone (NTZ) of South El Ghargana within the Nabq Managed Resource Protected Area, South Sinai, Egyptian Red Sea. Previous studies credited willing compliance by the local fishing community for the increased abundances of targeted fish within the designated NTZ boundaries compared to adjacent fished or take-zones. We compared benthic habitat and fish abundance within the NTZ and the adjacent take sites open to fishing, but found no significant effect of the reserve. Instead, the strongest evidence was for a simple negative relationship between fishing pressure and distance from the closest fishing village. The abundance of targeted piscivorous fish increased significantly with increasing distance from the village, while herbivorous fish showed the opposite trend. This gradient was supported by a corresponding negative correlation between the amount of discarded fishing gear observed on the reef and increasing distance from the village. Discarded fishing gear within the NTZ suggested decreased compliance with the no-take regulations. Our findings indicate that due to non-compliance the no-take reserve is no longer functioning effectively, despite its apparent initial successes and instead a gradient of fishing pressure exists with distance from the nearest fishing community.

THE CLASSIC WAY OF FISH PROCESSING

Directory of Open Access Journals (Sweden)

Đurica Kalember

1998-04-01

Full Text Available Today's population faces great difficulties in fish marketing, although it is very valuable food. The classic supply with fresh fish has little influence on its consumption, which is not remarkable anyhow. Therefore one shulud be reminded on the classic, almost forgotten, ways of fish processing that can substantially increase fish assortment and improve its distribution. After cleaning and cutting the fish (primary procedures in its processing, comes salting, after which the salted fish can become an end-product or it can be one of many semi-products in the fish production chain. The most common methods of fish salting are dry-salting, dry-wet-salting (Greek-Dalmatian and wet-salting (pickling. The aim of fish drying is its dehydratation. Our country has the experience of traditional drying, sun-drying and natural drying of fish. Each of these has its own special qualities, depending on the fish species and the drying temperature. Smoked fish gets a very distinctive and spicy aroma and a specific colour. There are two kinds of smoking - cold and warm - based on the smoke derived from burning some special trees or, lately, from smoke preparations. Marinades are old procedures of fish processing in acetic acid and specific spices which can be prepared cold, fried or cooked. Fish-roe of some specific fish species has a special value and is considered a delicacy. The most precious black caviar is derived from the sturgeon roe and some of its related species.

One Fish, Two Fish, Redfish, You Fish!

Science.gov (United States)

White, Katherine; Timmons, Maryellen; Medders, Paul

2011-01-01

The recreational fishing activity presented in this article provides a hands-on, problem-based experience for students; it unites biology, math, economics, environmental policy, and population dynamics concepts. In addition, the activity allows students to shape environmental policy in a realistic setting and evaluate their peers' work. By…

Scorpion fish sting

Science.gov (United States)

... page: //medlineplus.gov/ency/article/002849.htm Scorpion fish sting To use the sharing features on this page, please enable JavaScript. Scorpion fish are members of the family Scorpaenidae, which includes ...

A Study of Fish Lice (Argulus Sp. Infection in Freshwater Food Fish

Directory of Open Access Journals (Sweden)

Aalberg K.

2016-09-01

Full Text Available Argulus sp., commonly referred to as fish lice, are crustacean ectoparasites of fishes. The hematophagous parasites attach to and feed off the integument of their hosts. Outbreaks of epizootics have been reported worldwide, causing mass mortalities and having serious economic implications for fish farms and culture efforts. Argulus fish lice may also serve as vectors of infectious diseases and as intermediate hosts of other parasites. Two native European species, A. foliaceus and A. coregoni, as well as the invasive Japanese fish louse A. japonicus, have previously been recorded in Slovakia. This study investigated samples collected at fish farms and culture sites of Common carp (Cyprinus carpio L., Pike-perch (Sander lucioperca L. and Brook trout (Salvelinus fontinalis M. in Eastern Slovakia, as well as samples collected from live fish imported to the Slovak Republic. A quantitative description of the of Argulus sp. was recorded from each locality. Samples from Common carp were identified as the invasive A. japonicus, and samples from Pike-perch and Brook trout were identified as A. foliaceus. Evidence of a mixed infection of Pike-perch with both A. foliaceus and A. japonicus was found in samples from Zemplínska Šírava, which was substantiated by electron microscopic examination. Morphometric characteristics were measured and averages and ranges produced for each species and sex.

Fish parasites

DEFF Research Database (Denmark)

This book contains 22 chapters on some of the most important parasitic diseases in wild and farmed fish. International experts give updated reviews and provide solutions to the problems......This book contains 22 chapters on some of the most important parasitic diseases in wild and farmed fish. International experts give updated reviews and provide solutions to the problems...

Fish pelleting

African Journals Online (AJOL)

PUBLICATIONS1

fish meal pelletizing machine utilized 4kg of ingredients to produce 3.77kg pellets at an effi- ciency of .... Design and fabrication of fish meal pellet processing machine ... 53 ... horsepower for effective torque application on .... two edges were tacked with a spot weld to hold ... then welded on to the shaft making sure that the.

Design and testing of small scale fish meat bone separator useful for fish processing.

Science.gov (United States)

Ali Muhammed, M; Manjunatha, N; Murthy, K Venkatesh; Bhaskar, N

2015-06-01

The present study relates to the food processing machinery and, more specifically machine for producing boneless comminuted meat from raw fish fillet. This machine is of belt and drum type meat bone separator designed for small scale fish processing in a continuous mode. The basic principal involved in this machine is compression force. The electric geared motor consists of 1HP and the conveyor belt has a linear velocity of 19 to 22 m min(-1), which was sufficient to debone the fish effectively. During the meat bone separation trials an efficiency up to 75 % on dressed fish weight basis was observed and with a capacity to separate 70 kg h(-1) of meat from fish at the machine speed of 25 rpm. During the trials, it was demonstrated that there was no significant change in the proximate composition of comminuted fish meat when compared to unprocessed fish meat. This design has a greater emphasis on hygiene, provision for cleaning-in-place (CIP) and gives cost effective need and reliability for small scale industries to produce fish meat in turn used for their value added products.

[Performance evaluation of a fluorescamine-HPLC method for determination of histamine in fish and fish products].

Science.gov (United States)

Kikuchi, Hiroyuki; Tsutsumi, Tomoaki; Matsuda, Rieko

2012-01-01

A method for the quantification of histamine in fish and fish products using tandem solid-phase extraction and fluorescence derivatization with fluorescamine was previously developed. In this study, we improved this analytical method to develop an official test method for quantification of histamine in fish and fish products, and performed a single laboratory study to validate it. Recovery tests of histamine from fillet (Thunnus obesus), and two fish products (fish sauce and salted and dried whole big-eye sardine) that were spiked at the level of 25 and 50 µg/g for T. obesus, and 50 and 100 µg/g for the two fish products, were carried out. The recoveries of histamine from the three samples tested were 88.8-99.6% with good repeatability (1.3-2.1%) and reproducibility (2.1-4.7%). Therefore, this method is acceptable for the quantification of histamine in fish and fish products. Moreover, surveillance of histamine content in food on the market was conducted using this method, and high levels of histamine were detected in some fish products.

Gene Expression Contributes to the Recent Evolution of Host Resistance in a Model Host Parasite System

Directory of Open Access Journals (Sweden)

Brian K. Lohman

2017-09-01

Full Text Available Heritable population differences in immune gene expression following infection can reveal mechanisms of host immune evolution. We compared gene expression in infected and uninfected threespine stickleback (Gasterosteus aculeatus from two natural populations that differ in resistance to a native cestode parasite, Schistocephalus solidus. Genes in both the innate and adaptive immune system were differentially expressed as a function of host population, infection status, and their interaction. These genes were enriched for loci controlling immune functions known to differ between host populations or in response to infection. Coexpression network analysis identified two distinct processes contributing to resistance: parasite survival and suppression of growth. Comparing networks between populations showed resistant fish have a dynamic expression profile while susceptible fish are static. In summary, recent evolutionary divergence between two vertebrate populations has generated population-specific gene expression responses to parasite infection, affecting parasite establishment and growth.

Fish population dynamics

National Research Council Canada - National Science Library

Gulland, J. A

1977-01-01

This book describes how the dynamics of fish populations can be analysed in terms of the factors affecting their rates of growth, mortality and reproduction, with particular emphasis on the effects of fishing...

Histamine fish poisoning revisited.

Science.gov (United States)

Lehane, L; Olley, J

2000-06-30

Histamine (or scombroid) fish poisoning (HFP) is reviewed in a risk-assessment framework in an attempt to arrive at an informed characterisation of risk. Histamine is the main toxin involved in HFP, but the disease is not uncomplicated histamine poisoning. Although it is generally associated with high levels of histamine (> or =50 mg/100 g) in bacterially contaminated fish of particular species, the pathogenesis of HFP has not been clearly elucidated. Various hypotheses have been put forward to explain why histamine consumed in spoiled fish is more toxic than pure histamine taken orally, but none has proved totally satisfactory. Urocanic acid, like histamine, an imidazole compound derived from histidine in spoiling fish, may be the "missing factor" in HFP. cis-Urocanic acid has recently been recognised as a mast cell degranulator, and endogenous histamine from mast cell degranulation may augment the exogenous histamine consumed in spoiled fish. HFP is a mild disease, but is important in relation to food safety and international trade. Consumers are becoming more demanding, and litigation following food poisoning incidents is becoming more common. Producers, distributors and restaurants are increasingly held liable for the quality of the products they handle and sell. Many countries have set guidelines for maximum permitted levels of histamine in fish. However, histamine concentrations within a spoiled fish are extremely variable, as is the threshold toxic dose. Until the identity, levels and potency of possible potentiators and/or mast-cell-degranulating factors are elucidated, it is difficult to establish regulatory limits for histamine in foods on the basis of potential health hazard. Histidine decarboxylating bacteria produce histamine from free histidine in spoiling fish. Although some are present in the normal microbial flora of live fish, most seem to be derived from post-catching contamination on board fishing vessels, at the processing plant or in the

Parvalbumin--the major tropical fish allergen.

Science.gov (United States)

Lim, Dawn Li-Chern; Neo, Keng Hwee; Yi, Fong Cheng; Chua, Kaw Yan; Goh, Denise Li-Meng; Shek, Lynette Pei-Chi; Giam, Yoke Chin; Van Bever, Hugo P S; Lee, Bee Wah

2008-08-01

Fish allergy is common in countries where consumption is high. Asian nations are amongst the world's largest consumers of fish but the allergen profiles of tropical fish are unknown. This study sought to evaluate the allergenicity of four commonly consumed tropical fish, the threadfin (Polynemus indicus), Indian anchovy (Stolephorus indicus), pomfret (Pampus chinensis) and tengirri (Scomberomorus guttatus). Immunoglobulin E (IgE) cross-reactivity with parvalbumin of cod fish (Gad c 1), the major fish allergen, was also studied. Detection of tropical fish and cod specific-IgE was performed by UniCap assay, and skin prick tests were also carried out. The IgE-binding components of tropical fish were identified using IgE immunoblot techniques, and cross-reactivity with Gad c 1 was assessed by ELISA inhibition and IgE immunoblot inhibition. Clinically, nine of 10 patients studied were allergic to multiple fish. All patients exhibited detectable specific-IgE to cod fish (10 of 10 skin prick test positive, eight of 10 UniCap assay positive) despite lack of previous exposure. The major allergen of the four tropical fish was the 12-kDa parvalbumin. IgE cross-reactivity of these allergens to Gad c 1 was observed to be moderate to high in the tropical fish studied. Parvalbumins are the major allergens in commonly consumed tropical fish. They are cross-reactive with each other as well as with Gad c 1. Commercial tests for cod fish appear to be sufficient for the detection of tropical fish specific-IgE.

Distance from a fishing community explains fish abundance in a no-take zone with weak compliance.

Directory of Open Access Journals (Sweden)

Sahir Advani

Full Text Available There are numerous examples of no-take marine reserves effectively conserving fish stocks within their boundaries. However, no-take reserves can be rendered ineffective and turned into 'paper parks' through poor compliance and weak enforcement of reserve regulations. Long-term monitoring is thus essential to assess the effectiveness of marine reserves in meeting conservation and management objectives. This study documents the present state of the 15-year old no-take zone (NTZ of South El Ghargana within the Nabq Managed Resource Protected Area, South Sinai, Egyptian Red Sea. Previous studies credited willing compliance by the local fishing community for the increased abundances of targeted fish within the designated NTZ boundaries compared to adjacent fished or take-zones. We compared benthic habitat and fish abundance within the NTZ and the adjacent take sites open to fishing, but found no significant effect of the reserve. Instead, the strongest evidence was for a simple negative relationship between fishing pressure and distance from the closest fishing village. The abundance of targeted piscivorous fish increased significantly with increasing distance from the village, while herbivorous fish showed the opposite trend. This gradient was supported by a corresponding negative correlation between the amount of discarded fishing gear observed on the reef and increasing distance from the village. Discarded fishing gear within the NTZ suggested decreased compliance with the no-take regulations. Our findings indicate that due to non-compliance the no-take reserve is no longer functioning effectively, despite its apparent initial successes and instead a gradient of fishing pressure exists with distance from the nearest fishing community.

Consumers’ attitude towards fish meat

Directory of Open Access Journals (Sweden)

Francesca Conte

2014-09-01

Full Text Available The overall aim of this paper is to show the factors that may affect consumers’ attitude towards farmed fish products. Consumers ask new products on the basis of different quality attributes: stability, safety, composition, better health effects, environment protection, etc. Different and controversial opinions on farmed and wild fish are also explored by literature review. The authors pay attention also to fish welfare as an emerging issue and effective information about fish products as a factor exerting a positive influence on consumers’ decision of purchase. Some relevant legislative notes on the paper’s topics are also cited. The qualitative aspects of aquaculture fish and the consumers’ demand and choice need further studies, according to some factors, such as the changing consumers’ attitudes towards fish products, the different fish quality perception and the development in the aquaculture systems.

Contamination with heavy metals and bacteria in some local and imported fish and fish products

International Nuclear Information System (INIS)

Salem, S.B.; El-Dashlout, A.A.; El-Schiwee, M.A.; EL-Shourbagy, G.A.; Ibrahim, R.E.

2004-01-01

Some local and imported fish and fish products sold in retail markets of three cities at Sharkia Governorate, Egypt, were examined against heavy metals contamination (i.e. Pb, Cd and Hg) and the presence of some specific groups of bacteria. The results showed that concentrations of Pb in fresh and frozen fish, salted and smoked fish and canned fish samples were lower than the permissible limits recommended by the Egyptian Organization 1993 (1.0 mg/kg). On the other hand, all the tested fish and fish products of collected samples showed levels of Cd (0.29-0.41 mg/kg) higher than the permissible limit (0.10 mg/kg) recommended by the Egyptian Organization. Such limits should be re-considered because the limit determined by WHO (1992) was 0.5 mg/kg. Mercury level in fresh mullet was equal or lower (0.46-0.50 mg/kg) than the limit of Egyptian Organization (0.50 mg/kg) while other fresh and frozen fish, salted and smoked fish samples had higher Hg than the allowance. In most cases, imported canned products of sardine, mackerel and tuna had higher Pb, Cd and Hg concentrations than that found in the local ones. Among fresh fish samples, such as mackarona, contained the highest total bacterial count, while mullet was the lowest. Considering salted and smoked fish, heavy salted mullet had the highest total bacterial count, while the lowest number was recorded in salted sardine. Smoked herring showed lowest total bacterial count than salted samples. Generally, no correlation was observed between fish species or consumption place and the contamination with heavy metals and bacteria

[Imported tropical fish causes ciguatera fish poisoning in Germany].

Science.gov (United States)

Zimmermann, Katharina; Eisenblätter, Anneka; Vetter, Irina; Ebbecke, Martin; Friedemann, Miriam; Desel, Herbert

2015-01-01

Ciguatera is a seafood-borne illness caused by consumption of tropical fish contaminated with ciguatoxins, lipophilic polyethers that are produced in benthic dinoflagellates and accumulate through the marine food chain. Ciguatera cases in Europe usually occur in travellers returning from tropical and subtropical regions of the Pacific and Carribean, where ciguatera is endemic. In 2012, several cases of ciguatera occurred in Germany due to sale of contaminated fish products originating from the Indian Ocean. Although the symptomatology in these cases were typical of ciguatera, with patients reporting gastrointestinal discomfort including nausea, vomiting and diarrhea as well as neurological effects including widespread intense pruritus, paresthesias, hypothermia or altered temperature sensation and diffuse pain, correct diagnosis was delayed in all cases due to lack of awareness of the treating medical practitioners. In light of increasing global mobility, trade, and occurrence of ciguatoxic fish in previously non-endemic areas, ciguatera should be considered as a possible diagnosis if gastrointestinal and neurological symptoms occur shortly after consumption of fish. Georg Thieme Verlag Stuttgart.

Fish-friendly future

International Nuclear Information System (INIS)

Brookshier, P.; Newman, Gemma

2001-01-01

The latest US research into ways of reducing the harm to fish from hydroelectric turbines is outlined. Laboratory studies, field studies and advanced computational studies are being carried out to improve the understanding of and reduce the effects of stress and injury to fish from turbines. The Advanced Hydro Turbine System programme is part of the Department of Energy's Hydropower Programme. Turbine passage injuries are caused by a number of mechanisms, leaving the fish either dead or stunned. Advanced turbine technology can help to minimise fish injury and can add dissolved oxygen to the discharged water, thus improving water quality. Turbine modifications are aimed at all species, but studies have focussed on salmon, trout and eels. The new minimum gap runner (MGR) appear as efficient as standard Kaplan turbines

Of Fish and Micrornas

DEFF Research Database (Denmark)

Bela-Ong, Dennis; Schyth, Brian Dall; Lorenzen, Niels

Fish is an important small vertebrate multidisciplinary model for investigating various aspects of reproduction, development, disease (immunology, toxicology, carcinogenesis), and aging. It is also an important model for comparative and evolutionary studies because it represents the lower...... to the mechanisms of control of gene expression, impacting a broad range of biological processes. Thus far, >25, 000 miRNA sequences have been identified in 193 species, including fish. In fish, the interest on miRNAs started with the analysis of their expression and function during embryonic development. In our...... selection markers to identify disease-resistant fish....

Changes in the North Sea fish community: evidence of indirect effects of fishing?

NARCIS (Netherlands)

Daan, N.; Gislason, H.; Pope, J.G.; Rice, J.C.

2005-01-01

We investigate changes in the North Sea fish community with particular reference to possible indirect effects of fishing, mediated through the ecosystem. In the past, long-term changes in the slope of size spectra of research vessel catches have been related to changes in fishing effort, but such

Farming in a fish tank.

Science.gov (United States)

Youth, H

1992-01-01

Water, fish, and vegetables are all things that most developing countries do not have enough of. There is a method of food production called aquaculture that integrates fish and vegetable growing and conserves and purifies water at the same time. A working system that grows vegetables and fish for regional supermarkets in Massachusetts is a gravity fed system. At the top of the system is a 3,000 gallon fish rearing tank that measures 12 feet in diameter. Water trickles out of the tank and fish wastes are captured which can be composted and used in farm fields. The water goes into a bio filter that contains bacteria which convert harmful ammonia generated from fish waste into beneficial nitrate. Then the water flows into 100 foot long hydroponic tanks where lettuce grows. A 1/6 horsepower pump return the purified water to the fish tank and completes the cycle. The key to success is maintaining a balance between the fish nutrients and waste and the plants nutrients and waste. The system is estimated to produce 35,000 heads of lettuce and 2 tons of fish annually which translates into $23,500. The system could be adapted to developing countries with several modifications to reduce the start up cost.

Housekeeping genes for quantitative expression studies in the three-spined stickleback Gasterosteus aculeatus

NARCIS (Netherlands)

Hibbeler, S.; Scharsack, J.P.; Becker, S.

2008-01-01

Background During the last years the quantification of immune response under immunological challenges, e.g. parasitation, has been a major focus of research. In this context, the expression of immune response genes in teleost fish has been surveyed for scientific and commercial purposes. Despite the

Effects of discharge fluctuation and the addition of fine sediment on stream fish and macroinvertebrates below a water-filtration facility

Science.gov (United States)

Erman, Don C.; Ligon, Franklin K.

1988-01-01

A small, coastal stream in the San Francisco Bay area of California, USA, received the discharges from a drinking-water filtration plant. Two types of discharges were present. Discharges from filter backwashing were 3 4 times base stream flow, occurred 10 60 times per day, contained fine sediments, and each lasted about 10 min. The other discharge was a large, steady flow of relatively sediment-free water from occasional overflow of the delivery aqueduct which generally lasted several hours a day. Samples of invertebrates from natural substrates had significantly fewer taxa and lower density at the two stations below the backwash than at the two above. However, when stable artificial substrates were used, there were no significant differences among all four stations. The aqueduct apparently had no effect because the. invertebrate community at the station upstream of the backwash but downstream of the aqueduct was statistically similar to the station above the aqueduct. To test for acute toxicity, we exposed additional artificial substrates to short-term simulated backwash conditions. These exposures had no effect on invertebrate density or drift. Three-spine stickleback ( Gasterosteus aculeatus) populations were also significantly reduced at the two downstream stations and were made up mostly of larger, adult fish. Prickly sculpins ( Cottus asper), restricted to the most downstream station, were emaciated and had poor growth, probably as a result of scarce benthic food organisms. Artificial redds with eggs of rainbow trout ( Salmo gairdneri) had significantly lower survival at two stations below the plant backwash (30.7% and 41.8%) than at the one above it (61.4%). Hatchery rainbow trout held in cages below the treatment plant from 7 to 37 days survived and continued to feed. Thus, the major effect of the water treatment plant on fish and invertebrates probably was not from acute toxicity in the discharges or the occasionally large discharge of clean water from the