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Auteur Ferrari, S.; Horri, K.; Allal, F.; Vergnet, A.; Benhaim, D.; Vandeputte, M.; Chatain, B.; Begout, M.-L.
Titre Heritability of Boldness and Hypoxia Avoidance in European Seabass, Dicentrarchus labrax Type Article scientifique
Année (up) 2016 Publication Revue Abrégée PLoS One
Volume 11 Numéro 12 Pages e0168506
Mots-Clés atlantic salmon; behavioral plasticity; confinement stress; individual-differences; rainbow-trout; rearing conditions; Risk-taking; salmon salmo-salar; stress-coping styles; trout oncorhynchus-mykiss
Résumé To understand the genetic basis of coping style in European seabass, fish from a full factorial mating (10 females x 50 males) were reared in common garden and individually tagged. Individuals coping style was characterized through behavior tests at four different ages, categorizing fish into proactive or reactive: a hypoxia avoidance test (at 255 days post hatching, dph) and 3 risk-taking tests (at 276, 286 and 304 dph). We observed significant heritability of the coping style, higher for the average of risk-taking scores (h(2) = 0.45 +/- 0.14) than for the hypoxia avoidance test (h(2) = 0.19 +/- 0.10). The genetic correlations between the three risk-taking scores were very high (r(A) = 0.96-0.99) showing that although their repeatability was moderately high (r(P) = 0.64-0.72), successive risk-taking tests evaluated the same genetic variation. A mild genetic correlation between the results of the hypoxia avoidance test and the average of risk-taking scores (0.45 +/- 0.27) suggested that hypoxia avoidance and risk-taking tests do not address exactly the same behavioral and physiological responses. Genetic correlations between weight and risk taking traits showed negative values whatever the test used in our population i.e. reactive individual weights were larger. The results of this quantitative genetic analysis suggest a potential for the development of selection programs based on coping styles that could increase seabass welfare without altering growth performances. Overall, it also contributes to a better understanding of the origin and the significance of individual behavioral differences.
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ISSN 1932-6203 ISBN Médium
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Numéro d'Appel MARBEC @ alain.herve @ collection 2071
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Auteur Escalle, L.; Pennino, M.G.; Gaertner, D.; Chavance, P.; Delgado de Molina, A.; Demarcq, H.; Romanov, E.; Mérigot, B.
Titre Environmental factors and megafauna spatio-temporal co-occurrence with purse-seine fisheries Type Article scientifique
Année (up) 2016 Publication Revue Abrégée Fish. Oceanogr.
Volume 25 Numéro 4 Pages 433-447
Mots-Clés cetaceans; Eastern Atlantic Ocean; generalized additive models-boosted regression trees; marine conservation; purse-seine fishery; residual autocovariate; Western Indian Ocean; whale sharks
Résumé Tropical tuna purse-seine fisheries spatially co-occur with various megafauna species, such as whale sharks, dolphins and baleen whales in all oceans of the world. Here, we analyzed a 10-year (2002–2011) dataset from logbooks of European tropical tuna purse-seine vessels operating in the tropical Eastern Atlantic and Western Indian Oceans, with the aim of identifying the principle environmental variables under which such co-occurrence appear. We applied a Delta-model approach using Generalized Additive Models (GAM) and Boosted Regression Trees (BRT) models, accounting for spatial autocorrelation using a contiguity matrix based on a residuals autocovariate (RAC) approach. The variables that contributed most in the models were chlorophyll-a concentration in the Atlantic Ocean, as well as depth and monsoon in the Indian Ocean. High co-occurrence between whale sharks, baleen whales and tuna purse-seine fisheries were mostly observed in productive areas during particular seasons. In light of the lack of a full coverage scientific observer on board program, the large, long-term dataset obtained from logbooks of tuna purse-seine vessels is highly important for identifying seasonal and spatial co-occurrence between the distribution of fisheries and megafauna, and the underlying environmental variables. This study can help to design conservation management measures for megafauna species within the framework of spatial fishery management strategies.
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Volume de collection Numéro de collection Edition
ISSN 1365-2419 ISBN Médium
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Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 1587
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Auteur Sebastian, M.; Smith, A.F.; Gonzalez, J.M.; Fredricks, H.F.; Van Mooy, B.; Koblizek, M.; Brandsma, J.; Koster, G.; Mestre, M.; Mostajir, B.; Pitta, P.; Postle, A.D.; Sanchez, P.; Gasol, J.M.; Scanlan, D.J.; Chen, Y.
Titre Lipid remodelling is a widespread strategy in marine heterotrophic bacteria upon phosphorus deficiency Type Article scientifique
Année (up) 2016 Publication Revue Abrégée Isme J.
Volume 10 Numéro 4 Pages 968-978
Mots-Clés 2 enzymes; agrobacterium-tumefaciens; bacterioplankton groups; Ecology; Mediterranean Sea; mesocosm experiment; microbial food-web; north-atlantic ocean; nutrient limitation; phosphate starvation
Résumé Upon phosphorus (P) deficiency, marine phytoplankton reduce their requirements for P by replacing membrane phospholipids with alternative non-phosphorus lipids. It was very recently demonstrated that a SAR11 isolate also shares this capability when phosphate starved in culture. Yet, the extent to which this process occurs in other marine heterotrophic bacteria and in the natural environment is unknown. Here, we demonstrate that the substitution of membrane phospholipids for a variety of non-phosphorus lipids is a conserved response to P deficiency among phylogenetically diverse marine heterotrophic bacteria, including members of the Alphaproteobacteria and Flavobacteria. By deletion mutagenesis and complementation in the model marine bacterium Phaeobacter sp. MED193 and heterologous expression in recombinant Escherichia coli, we confirm the roles of a phospholipase C (PlcP) and a glycosyltransferase in lipid remodelling. Analyses of the Global Ocean Sampling and Tara Oceans metagenome data sets demonstrate that PlcP is particularly abundant in areas characterized by low phosphate concentrations. Furthermore, we show that lipid remodelling occurs seasonally and responds to changing nutrient conditions in natural microbial communities from the Mediterranean Sea. Together, our results point to the key role of lipid substitution as an adaptive strategy enabling heterotrophic bacteria to thrive in the vast P-depleted areas of the ocean.
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Langue English Langue du Résumé Titre Original
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Volume de collection Numéro de collection Edition
ISSN 1751-7362 ISBN Médium
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Numéro d'Appel MARBEC @ alain.herve @ collection 1624
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Auteur Dalongeville, A.; Andrello, M.; Mouillot, D.; Albouy, C.; Manel, S.
Titre Ecological traits shape genetic diversity patterns across the Mediterranean Sea: a quantitative review on fishes Type Article scientifique
Année (up) 2016 Publication Revue Abrégée J. Biogeogr.
Volume 43 Numéro 4 Pages 845-857
Mots-Clés atlantic bluefin tuna; bass dicentrarchus-labrax; climate-change; cod gadus-morhua; ecological traits; effective population-size; genetic diversity; gilthead sea; life-history traits; marine fishes; marine populations; Mediterranean Sea; microsatellite markers; microsatellites; mitochondrial; mitochondrial DNA; molecular markers; population genetics
Résumé AimWe set out to identify the determinants of the variation in genetic diversity among fish species and test whether multi-species genetic diversity is randomly distributed in space. LocationMediterranean Sea. MethodsWe collected genetic diversity data from 39 published studies on Mediterranean fishes (31 species) along with the spatial coordinates of the sampling sites. We focused on microsatellite heterozygosity (151 data points) and mitochondrial haplotype diversity (201 data points). We used linear regressions to link genetic diversity and 11 ecological traits. We also tested for spatial autocorrelation and trends in the residuals. ResultsAmong-species variation in microsatellite heterozygosity was explained by three ecological traits: vertical distribution, migration type and body length. Variation in mitochondrial haplotype diversity was also explained by vertical distribution and migration type, and by reproductive strategy (semelparity). However, vertical distribution and migration type showed opposite effects on microsatellites and mitochondrial diversity. After accounting for the effects of ecological traits, no spatial pattern was detected, except for one of the species considered. Main conclusionsEcological factors explain an important proportion of the among-species genetic diversity. These results suggest that life history strategies of the species influence the variation of microsatellite diversity indirectly through their effect on effective population size, while the spatial variations of genetic diversity seem to be too complex to be identified in our analysis. We found very different effects of traits on mitochondrial and nuclear DNA diversity, which can be explained by the specificities of mitochondrial DNA (absence of recombination, maternal inheritance and non-neutrality).
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Langue English Langue du Résumé Titre Original
Éditeur de collection Titre de collection Titre de collection Abrégé
Volume de collection Numéro de collection Edition
ISSN 0305-0270 ISBN Médium
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Numéro d'Appel MARBEC @ alain.herve @ collection 1627
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Auteur Escalle, L.; Gaertner, D.; Chavance, P.; Delgado de Molina, A.; Ariz, J.; Mérigot, B.
Titre Consequences of fishing moratoria on catch and bycatch: the case of tropical tuna purse-seiners and whale and whale shark associated sets Type Article scientifique
Année (up) 2016 Publication Revue Abrégée Biodivers. Conserv.
Volume 25 Numéro 9 Pages 1637-1659
Mots-Clés atlantic-ocean; Before-after analysis; dolphin; dynamics; fisheries; impacts; management; Marine megafauna; Monte Carlo simulation; mortality; Purse-seine fishery; strategies; time; Time-area regulation
Résumé Time-area regulations have been introduced to manage stocks of tropical tuna, given the increased use of drifting fish aggregation devices (FADs). However, the consequences in terms of changes in fishing strategies and effort reallocation may not always be as expected. For instance, in the eastern Pacific Ocean, previous studies have highlighted that the increase use of FAD-fishing following the demand for tuna caught without dolphin mortality has raised concerns about the bycatch and the capture of juvenile tuna. In the tropical eastern Atlantic and western Indian Oceans, this study aimed to (1) assess, using before-after analysis, the consequences of previous time-area regulations on FAD sets on the fishing effort allocated to megafauna associated sets, and (2) evaluate through Monte Carlo simulations the potential effect of new regulations banning whale or/and whale shark associated sets. Firstly, we showed that previous time-area regulations, which were mainly implemented during seasons with few whale and whale shark associated sets, generally had thus little effect on the number of megafauna associated sets. Secondly, some simulations, particularly when both whale and whale shark associated sets were banned, predicted consequences of changes in fishing strategy. Indeed, these types of ban could lead to an increase in the number of FAD and free school sets but no change in the tuna catch, as well as a slight decrease in bycatch. These results indicate that an ecosystem approach to fisheries, by taking into account megafauna associated sets and bycatch, should thus be adopted when implementing management or conservation measures.
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Langue English Langue du Résumé Titre Original
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Volume de collection Numéro de collection Edition
ISSN 0960-3115 ISBN Médium
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Numéro d'Appel MARBEC @ alain.herve @ collection 1640
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