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Auteur Mazel, F.; Renaud, J.; Guilhaumon, F.; Mouillot, D.; Gravel, D.; Thuiller, W. url  doi
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  Titre Mammalian phylogenetic diversity-area relationships at a continental scale Type Article scientifique
  Année 2015 Publication Revue Abrégée Ecology  
  Volume 96 Numéro 10 Pages 2814-2822  
  Mots-Clés Biodiversity; Biogeography; community ecology; conservation; conservation biogeography; habitat loss; habitat loss; null models; overestimate extinction rates; patterns; phylogenetic diversity; richness; species-area; species-area relationship; statistics; strict nested design  
  Résumé In analogy to the species-area relationship (SAR), one of the few laws in ecology, the phylogenetic diversity-area relationship (PDAR) describes the tendency of phylogenetic diversity (PD) to increase with area. Although investigating PDAR has the potential to unravel the underlying processes shaping assemblages across spatial scales and to predict PD loss through habitat reduction, it has been little investigated so far. Focusing on PD has noticeable advantages compared to species richness (SR), since PD also gives insights on processes such as speciation/extinction, assembly rules and ecosystem functioning. Here we investigate the universality and pervasiveness of the PDAR at continental scale using terrestrial mammals as study case. We define the relative robustness of PD (compared to SR) to habitat loss as the area between the standardized PDAR and standardized SAR (i.e., standardized by the diversity of the largest spatial window) divided by the area under the standardized SAR only. This metric quantifies the relative increase of PD robustness compared to SR robustness. We show that PD robustness is higher than SR robustness but that it varies among continents. We further use a null model approach to disentangle the relative effect of phylogenetic tree shape and nonrandom spatial distribution of evolutionary history on the PDAR. We find that, for most spatial scales and for all continents except Eurasia, PDARs are not different from expected by a model using only the observed SAR and the shape of the phylogenetic tree at continental scale. Interestingly, we detect a strong phylogenetic structure of the Eurasian PDAR that can be predicted by a model that specifically account for a finer biogeographical delineation of this continent. In conclusion, the relative robustness of PD to habitat loss compared to species richness is determined by the phylogenetic tree shape but also depends on the spatial structure of PD.  
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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 0012-9658 ISBN Médium  
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  Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 1423  
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Auteur Forget, F.; Dagorn, L.; Mérigot, B.; Gaertner, J.C.; Robinson, J.; Cowley, P.D.; Adam, M.S.; Rilwan, Y.; Koonjul, M.; Mangar, V.; Taquet, M.; Ménard, F. url  doi
openurl 
  Titre Beta diversity of pelagic assemblages at fish aggregating devices in the open ocean Type Article scientifique
  Année 2020 Publication Revue Abrégée African Journal of Marine Science  
  Volume 42 Numéro 2 Pages 247-254  
  Mots-Clés FADs; Indian Ocean; Maldives; Mauritius; pelagic fish diversity; Seychelles; species composition; underwater visual census  
  Résumé Owing to difficulties in accessing the vast open ocean, the beta (β) diversity of pelagic fish assemblages remains poorly studied. We investigated the relationship between assemblage similarity and geographical distance between anchored fish aggregating devices (FADs), sampled by standardised underwater visual censuses in three anchored FAD arrays in the Indian Ocean—at the Maldives, the Seychelles and Mauritius. The use of two complementary indices of β-diversity, based on presence/absence data (Jaccard similarity coefficient) and abundance data (Bray–Curtis index), revealed that geographical distance between sampling sites (from 4 to 257 km) appeared to have no effect on the similarity of fish assemblages associated with FADs within each array. The results of this preliminary study question the generalisation of the paradigm of an increase in β-diversity with geographic distance to the open-ocean fish community. Large-scale studies using a variety of datasets should be conducted to further investigate patterns of β-diversity in the open ocean.  
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  Langue Langue du Résumé Titre Original  
  Éditeur de collection Titre de collection Titre de collection Abrégé  
  Volume de collection Numéro de collection Edition  
  ISSN 1814-232x ISBN Médium  
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  Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 2813  
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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
openurl 
  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 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  
  Région Expédition Conférence  
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  Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 2494  
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Auteur Alves-Júnior, F.D.A.; Silva, E.D.S.; Araújo, M.D.S.L.C.D.; Cardoso, I.; Bertrand, A.; Souza-Filho, J.F. url  doi
openurl 
  Titre Taxonomy of deep-sea shrimps of the Superfamily Oplophoroidea Dana 1852 (Decapoda: Caridea) from Southwestern Atlantic Type Article scientifique
  Année 2019 Publication Revue Abrégée Zootaxa  
  Volume 4613 Numéro 3 Pages 401-442  
  Mots-Clés Crustacea; Acanthephyridae; New Records; bathypelagic shrimps; deep waters; deep-sea biodiversity; Northeastern Brazil; Oplophoridae  
  Résumé In this paper, we provide some available information about the occurrence and some taxonomic aspects of 19 species from the Superfamily Oplophoroidea in the southwestern Atlantic (Brazilian waters), with the update to 22 species of Oplophoroidea occurring in Brazilian waters. Samples were collected during two sets of surveys. The first was performed in 2009 and 2011 in the Potiguar Basin in northeast of Brazil (03–05°S; 38–35°W; between the States of Ceará and Rio Grande do Norte) under the framework of the project “Avaliação da biota bentônica e planctônica da Bacia Potiguar e Ceará (Bpot)”, with samples collected from bottom trawls in the continental slope at depth ranging from 150–2068 m. Second, under the in the framework of the ABRACOS (Acoustic along the Brazilian coast), performed in 2015 and 2017 on seamounts and offshore areas in Northeast Brazil (Ceará Chain, Rio Grande do Norte and Rocas Atoll, Fernando de Noronha Archipelago and Pernambuco State), with samples with pelagic micronekton and mesopelagic nets, in depths ranging from 50–1260 m. We highlight the occurrence of 14 species of the family Acanthephyridae and 5 species of the family Oplophoridae, including the first occurrences of five species to Brazilian deep waters: Acanthephyra kingsleyi Spence Bate, 1888, Ephyrina ombango Crosnier & Forest, 1973, Meningodora compsa (Chace, 1940), M. longisulca Kikuchi, 1985 and Systellapsis curvispina Crosnier, 1987. These records increase the knowledge on deep-sea shrimps occurring in Southwestern Atlantic.  
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  Langue en Langue du Résumé Titre Original  
  Éditeur de collection Titre de collection Titre de collection Abrégé  
  Volume de collection Numéro de collection Edition  
  ISSN 1175-5334 ISBN Médium  
  Région Expédition Conférence  
  Notes Approuvé pas de  
  Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 2584  
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Auteur Clavareau, L.; Sabarros, P.S.; Escalle, L.; Bach, P.; Abascal, F.J.; Lopez, J.; Murua, H.; Pascual Alayon, P.J.; Ramos, M.L.; Ruiz, J.; Mérigot, B. url  doi
openurl 
  Titre Elasmobranch bycatch distributions and mortality: Insights from the European tropical tuna purse-seine fishery Type Article scientifique
  Année 2020 Publication Revue Abrégée Global Ecology and Conservation  
  Volume 24 Numéro Pages e01211  
  Mots-Clés At-haulback mortality; Biodiversity; Life stage; Sex ratio; Spatio-temporal distribution  
  Résumé Despite bycatch of elasmobranch (sharks and rays) being a major concern in most fisheries worldwide, there is a lack of knowledge on their spatio-temporal species distribution, biology (life stage and sex-ratios), as well as their at-haulback mortality rate. Observer data from the French and Spanish tropical purse-seine tuna fisheries operating in the eastern Atlantic and western Indian Oceans between 2005 and 2017 were analysed to investigate elasmobranch bycatch. Data included 24 elasmobranchs species and distribution patterns of catch per unit of effort (CPUE) by species and sex-ratio were found to vary with life stages, areas, seasons and fishing modes. In general, higher catches were found in FAD-associated sets (>40%) than free tuna school sets (<17%) although this can vary depending on the species. For the large majority of species, a high proportion of juveniles were caught (30.7–100%), apparent at-haulback mortality rates was high (24.3–63.9%) and finally sex ratios was unbalanced (13.3–66.7% of females). Areas and seasons identified from these different components should be of interest for the monitoring and management of elasmobranch bycatches.  
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  Langue en Langue du Résumé Titre Original  
  Éditeur de collection Titre de collection Titre de collection Abrégé  
  Volume de collection Numéro de collection Edition  
  ISSN 2351-9894 ISBN Médium  
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  Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 2812  
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