Przybyla, C., Fievet, J., Callier, M., & Blancheton, J. - P. (2014). Effect of dietary water content on European sea bass (Dicentrarchus labrax) growth and disease resistance. Aquat. Living Resour., 27(2), 73–81.
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Pool, T. K., Grenouillet, G., & Villeger, S. (2014). Species contribute differently to the taxonomic, functional, and phylogenetic alpha and beta diversity of freshwater fish communities. Diversity and Distributions, 20(11), 1235–1244.
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Patino, J., Weigelt, P., Guilhaumon, F., Kreft, H., Triantis, K. A., Naranjo-Cigala, A., et al. (2014). Differences in species-area relationships among the major lineages of land plants: a macroecological perspective. Global Ecology and Biogeography, 23(11), 1275–1283.
Résumé: AimAlthough the increase in species richness with increasing area is considered one of the few laws in ecology, the role of environmental and taxon-specific features in shaping species-area relationships (SARs) remains controversial. Using 421 land-plant floras covering continents, continental islands and oceanic islands, we investigate whether variations in SAR parameters can be interpreted in terms of differences among lineages in speciation mode and dispersal capacities (TAXON), or of geological history and geographical isolation between continents and islands (GEO). LocationGlobal. MethodsLinear mixed-effects models describing variation in SARs, depending on the factors GEO and TAXON and controlling for differences between realms (REALM) and biomes (BIOME). ResultsThe best random-effect structure included both random slopes and random intercepts for GEO, TAXON, REALM and BIOME. This accounted for 77% of the total variation in species richness, substantially more than the 27% statistically explained by the model with fixed effects only (i.e. the simple SAR). The slopes of the SARs were higher for oceanic islands than for continental islands and continents, and higher in spermatophytes than in pteridophytes and bryophytes. The intercepts largely exhibited the reverse trend. TAXON was included in best-fit models restricted to oceanic and continental islands, but not continents. Analysing each plant lineage separately, the intercept of GEO was only included in the random structure of spermatophytes. Main conclusionsSAR parameters varied considerably depending on geological history and taxon-specific traits. Such differences in SARs among land plants challenge the neutral theory that the accumulation of species richness on islands is controlled exclusively by extrinsic factors. Taxon-specific differences in SARs were, however, confounded by interactions with geological history and geographical isolation. This highlights the importance of applying integrative frameworks that take both environmental context and taxonomic idiosyncrasies into account in SAR analyses.
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Nguyen-Kim, H., Bouvier, T., Bouvier, C., Hai, D. N., Lam, N. N., Rochelle-Newall, E., et al. (2014). High occurrence of viruses in the mucus layer of scleractinian corals. Environmental Microbiology Reports, 6(6), 675–682.
Résumé: Viruses attract increasing interest from environmental microbiologists seeking to understand their function and role in coral health. However, little is known about their main ecological traits within the coral holobiont. In this study, a quantitative and qualitative characterization of viral and bacterial communities was conducted on the mucus of seven different coral species of the Van Phong Bay (Vietnam). On average, the concentrations of viruses and bacteria were, respectively, 17- and twofold higher in the mucus than in the surrounding water. The examination of bacterial community composition also showed remarkable differences between mucus and water samples. The percentage of active respiring cells was nearly threefold higher in mucus (m=24.8%) than in water (m=8.6%). Interestingly, a positive and highly significant correlation was observed between the proportion of active cells and viral abundance in the mucus, suggesting that the metabolism of the bacterial associates is probably a strong determinant of the distribution of viruses within the coral holobiont. Overall, coral mucus, given its unique physicochemical characteristics and sticking properties, can be regarded as a highly selective biotope for abundant, diversified and specialized symbiotic microbial and viral organisms.
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Morat, F., Letourneur, Y., Blamart, D., Pecheyran, C., Darnaude, A. M., & Harmelin-Vivien, M. (2014). Offshore-onshore linkages in the larval life history of sole in the Gulf of Lions (NW-Mediterranean). Estuarine Coastal and Shelf Science, 149, 194–202.
Résumé: Understanding individual dispersion from offshore natal areas to coastal nurseries during pelagic larval life is especially important for the sustainable management of exploited marine fish species. For several years, the hatching period, the larval life duration, the average growth rate and the otolith chemical composition (delta C-13, delta O-18, Sr:Ca and Ba:Ca) during the larval life were studied for young of the year (YOY) of sole collected in three main nurseries of the Gulf of Lions (GoL) (Thau, Mauguio and Berre). We investigated the spatial variation in the origin of the sole larvae which colonised the nurseries around the GoL, and whether temporal differences in environmental conditions during this life stage affected growth and larval life duration. The hatching period ranges from October to March, depending on year and site. Average ages at metamorphosis varied between 43 and 50 days, with the lowest and highest values consistently found for Mauguio and Berre, respectively. Otolith growth rates ranged between 2.7 and 3.2 mu m d(-1), with the lowest values in Thau and Mauguio and the highest in Berre. Otolith chemical composition during the larval life also varied, suggesting contrasted larval environmental histories in YOY among nurseries. In fishes from Berre and Mauguio, larval life was more influenced by the Rhone River, showing consistently higher larval Ba:Ca ratios (10/23 mu mol mol(-1)) and lower delta C-13 (-6.5/-6.1 parts per thousand) and delta O-18 values (-1.6/0.1 parts per thousand) than for Thau (with Ba:Ca ratios < 8 mu mol mol(-1), delta C-13 similar to-2.3 parts per thousand and delta O-18 similar to 1.5 parts per thousand). Differences in larval otolith composition were observed for 2004, with higher Ba:Ca and lower delta C-13 and delta O-18 values than in the two other years. These differences were explained by changes in composition and chemical signatures of water masses after an exceptional flooding event of the Rhone River in late 2003. (C) 2014 Elsevier Ltd. All rights reserved.
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