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Auteur Zhao, T.; Villeger, S.; Cucherousset, J. doi  openurl
  Titre Accounting for intraspecific diversity when examining relationships between non-native species and functional diversity Type Article scientifique
  Année (down) 2019 Publication Revue Abrégée Oecologia  
  Volume 189 Numéro 1 Pages 171-183  
  Mots-Clés fish; Intraspecific variability; size; disturbance; Non-native species; phenotypic plasticity; Functional diversity; reveals; catfish silurus-glanis; coexistence; Community assembly; energy relationships; Functional traits; success; trait variability  
  Résumé Quantifying changes in functional diversity, the facet of biodiversity accounting for the biological features of organisms, has been advocated as one of the most integrative ways to unravel how communities are affected by human-induced perturbations. The present study assessed how functional diversity patterns varied among communities that differed in the degree to which non-native species dominated the community in temperate lake fish communities and whether accounting for intraspecific functional variability could provide a better understanding of the variation of functional diversity across communities. Four functional diversity indices were computed for 18 temperate lake fish communities along a gradient of non-native fish dominance using morphological functional traits assessed for each life-stage within each species. First, we showed that intraspecific variability in functional traits was high and comparable to interspecific variability. Second, we found that non-native fish were functionally distinct from native fish. Finally, we demonstrated that there was a significant relationship between functional diversity and the degree to which non-native fish currently dominated the community and that this association could be better detected when accounting for intraspecific functional variability. These findings highlighted the importance of incorporating intraspecific variability to better quantify the variation of functional diversity patterns in communities facing human-induced perturbations.  
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  Langue English Langue du Résumé Titre Original  
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  Volume de collection Numéro de collection Edition  
  ISSN 0029-8549 ISBN Médium  
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  Numéro d'Appel MARBEC @ alain.herve @ collection 2479  
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Auteur Escalle, L.; Gaertner, D.; Chavance, P.; Murua, H.; Simier, M.; Jose Pascual-Alayon, P.; Menard, F.; Ruiz, J.; Abascal, F.; Mérigot, B. doi  openurl
  Titre Catch and bycatch captured by tropical tuna purse-seine fishery in whale and whale shark associated sets: comparison with free school and FAD sets Type Article scientifique
  Année (down) 2019 Publication Revue Abrégée Biodivers. Conserv.  
  Volume 28 Numéro 2 Pages 467-499  
  Mots-Clés diversity; mortality; atlantic; biology; Bycatch; strategies; Megafauna; behavior; dominance; yellowfin; Catch composition; Diversity; Ecosystem approach to fisheries management; swimming speeds; Tuna purse-seine fishery  
  Résumé In an ecosystem approach to fisheries management (EAFM) framework of the tuna purse-seine fishery, the assessment of target species, but also that of bycatch species, is essential. In the Atlantic and Indian oceans, purse-seine nets are sometimes set around tuna schools associated with whale sharks and baleen whales, although less frequently than around free-swimming tuna schools or those associated with fish aggregating devices (FAD). However, knowledge on the targeted catch and bycatch in these megafauna associated fishing sets is still relatively limited. Therefore, the aims of this study were to assess species and size composition of the target tuna species, as well as the diversity of bycatch species in whale and whale shark associated sets. Whale associated sets were found to be very similar to free school sets in terms of tuna catch (large yellowfin tuna), bycatch occurrence (presence in half the sets) and species assemblage (alpha and beta diversity). Whale shark associated sets were intermediate between FAD and free school sets, with tuna catch (skipjack and juvenile yellowfin) closer to FAD than to free school sets. However, the presence of large yellowfin, the bycatch composition (with almost no finfish, abundantly captured in FAD sets) and the species assemblage showed similarity with free school sets. This study highlights the need for an EAFM in the tuna purse-seine fishery by providing knowledge on pelagic multi-specific catches and bycatches.  
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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 2482  
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Auteur Bernard, C.; Escalas, A.; Villeriot, N.; Agogué, H.; Hugoni, M.; Duval, C.; Carré, C.; Got, P.; Sarazin, G.; Jézéquel, D.; Leboulanger, C.; Grossi, V.; Ader, M.; Troussellier, M. url  doi
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  Titre Very Low Phytoplankton Diversity in a Tropical Saline-Alkaline Lake, with Co-dominance of Arthrospira fusiformis (Cyanobacteria) and Picocystis salinarum (Chlorophyta) Type Article scientifique
  Année (down) 2019 Publication Revue Abrégée Microb Ecol  
  Volume 78 Numéro 3 Pages 603-617  
  Mots-Clés Cyanobacteria; Diversity; Extreme environment; Phytoplankton; Picoeukaryote; Thalassohaline lake  
  Résumé Lake Dziani Dzaha (Mayotte Island, Indian Ocean) is a tropical thalassohaline lake which geochemical and biological conditions make it a unique aquatic ecosystem considered as a modern analogue of Precambrian environments. In the present study, we focused on the diversity of phytoplanktonic communities, which produce very high and stable biomass (mean2014–2015 = 652 ± 179 μg chlorophyll a L−1). As predicted by classical community ecology paradigms, and as observed in similar environments, a single species is expected to dominate the phytoplanktonic communities. To test this hypothesis, we sampled water column in the deepest part of the lake (18 m) during rainy and dry seasons for two consecutive years. Phytoplanktonic communities were characterized using a combination of metagenomic, microscopy-based and flow cytometry approaches, and we used statistical modeling to identify the environmental factors determining the abundance of dominant organisms. As hypothesized, the overall diversity of the phytoplanktonic communities was very low (15 OTUs), but we observed a co-dominance of two, and not only one, OTUs, viz., Arthrospira fusiformis (Cyanobacteria) and Picocystis salinarum (Chlorophyta). We observed a decrease in the abundance of these co-dominant taxa along the depth profile and identified the adverse environmental factors driving this decline. The functional traits measured on isolated strains of these two taxa (i.e., size, pigment composition, and concentration) are then compared and discussed to explain their capacity to cope with the extreme environmental conditions encountered in the aphotic, anoxic, and sulfidic layers of the water column of Lake Dziani Dzaha.  
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  Volume de collection Numéro de collection Edition  
  ISSN 1432-184x ISBN Médium  
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  Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 2494  
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Auteur Barneche, D.R.; Rezende, E.L.; Parravicini, V.; Maire, Eva; Edgar, G.J.; Stuart-Smith, R.D.; Arias-Gonzalez, J.E.; Ferreira, C.E.L.; Friedlander, A.M.; Green, A.L.; Luiz, O.J.; Rodriguez-Zaragoza, F.A.; Vigliola, L.; Kulbicki, M.; Floeter, S.R. doi  openurl
  Titre Body size, reef area and temperature predict global reef-fish species richness across spatial scales Type Article scientifique
  Année (down) 2019 Publication Revue Abrégée Glob. Ecol. Biogeogr.  
  Volume 28 Numéro 3 Pages 315-327  
  Mots-Clés biodiversity; diversity; patterns; coral-reefs; spatial scale; community assembly; biogeography; extrapolation; local diversity; neutral theory; range size; rarefaction; regional diversity; species energy  
  Résumé Aim To investigate biotic and abiotic correlates of reef-fish species richness across multiple spatial scales. Location Tropical reefs around the globe, including 485 sites in 109 sub-provinces spread across 14 biogeographic provinces. Time period Present. Major taxa studied 2,523 species of reef fish. Methods We compiled a database encompassing 13,050 visual transects. We used hierarchical linear Bayesian models to investigate whether fish body size, reef area, isolation, temperature, and anthropogenic impacts correlate with reef-fish species richness at each spatial scale (i.e., sites, sub-provinces, provinces). Richness was estimated using coverage-based rarefaction. We also tested whether species packing (i.e., transect-level species richness/m(2)) is correlated with province-level richness. Results Body size had the strongest effect on species richness across all three spatial scales. Reef area and temperature were both positively correlated with richness at all spatial scales. At the site scale only, richness decreased with reef isolation. Species richness was not correlated with proxies of human impacts. Species packing was correlated with species richness at the province level following a sub-linear power function. Province-level differences in species richness were also mirrored by patterns of body size distribution at the site scale. Species-rich provinces exhibited heterogeneous assemblages of small-bodied species with small range sizes, whereas species-poor provinces encompassed homogeneous assemblages composed by larger species with greater dispersal capacity. Main conclusions Our findings suggest that body size distribution, reef area and temperature are major predictors of species richness and accumulation across scales, consistent with recent theories linking home range to species-area relationships as well as metabolic effects on speciation rates. Based on our results, we hypothesize that in less diverse areas, species are larger and likely more dispersive, leading to larger range sizes and less turnover between sites. Our results indicate that changes in province-level (i.e., regional) richness should leave a tractable fingerprint in local assemblages, and that detailed studies on local-scale assemblage composition may be informative of responses occurring at larger scales.  
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  Editeur Lieu de Publication Éditeur  
  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 1466-822x ISBN Médium  
  Région Expédition Conférence  
  Notes Approuvé pas de  
  Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 2522  
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Auteur Su, G.; Villeger, S.; Brosse, S. doi  openurl
  Titre Morphological diversity of freshwater fishes differs between realms, but morphologically extreme species are widespread Type Article scientifique
  Année (down) 2019 Publication Revue Abrégée Glob. Ecol. Biogeogr.  
  Volume 28 Numéro 2 Pages 211-221  
  Mots-Clés diet; ecology; patterns; vulnerability; richness; freshwater fish; functional diversity; extinction risk; traits; biogeographical realms; functional redundancy; functional vulnerability; mismatch; morphological traits; morphologically extreme species; rivers  
  Résumé Aim The aim was to analyse the morphological diversity of the world freshwater fish fauna. We tested to which extent the distributions of morphological traits are supported by extreme morphologies and how those extreme morphologies are distributed among realms and affect the functional vulnerability. We also analysed the contribution of between- and within-order morphological variability to the morphological differences between realms. Major taxa studied Freshwater fish. Location Global. Time period 1960s-2010s. Methods We used a global database of freshwater fishes from the six realms. Ten morphological traits were measured on 9,150 species, that is, 75% of the ca. 13,000 freshwater fish species. A principal components analysis was conducted to combine the 10 traits into a multidimensional space. We used Kolmogorov-Smirnov tests to compare the difference in morphological diversity between the six realms and between and within the major fish orders. We then identified the morphologically extreme species and quantified their contributions to the morphological range to assess the functional vulnerability and redundancy of fish faunas in the six biogeographical realms for freshwater ecosystems. Results We report a strong morphological variability among freshwater fishes of the world, with significant morphological differences among realm fish faunas, caused by an interplay between taxonomic composition of the realm faunas and morphological differences within orders among the realms. Morphologically extreme species accounted for a large percentage of the filling of the global morphological space and are distributed throughout the world. Main conclusions Fish morphological diversity is largely supported by a few species with extreme trait combinations, indicating that functional vulnerability exists throughout the world. Our results suggest that more attention should be paid to these morphologically extreme species and that they should be protected to ensure the sustainability of functions they support.  
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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 1466-822x ISBN Médium  
  Région Expédition Conférence  
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  Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 2528  
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