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Auteur Ménard, F.; Potier, M.; Jaquemet, S.; Romanov, E.; Sabatié, R.; Cherel, Y. url  doi
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  Titre Pelagic cephalopods in the western Indian Ocean: New information from diets of top predators Type Article scientifique
  Année 2013 Publication Revue Abrégée Deep Sea Research Part II: Topical Studies in Oceanography  
  Volume 95 Numéro Pages 83-92  
  Mots-Clés ecology; Trophic  
  Résumé Using a combination of diverse large predatory fishes and one seabird, we collected information on the cephalopod fauna of the western Indian Ocean. We analyzed the stomach contents of 35 fishes representing ten families (Xiphiidae, Istiophoridae, Scombridae, Carangidae, Coryphaenidae, Alepisauridae, Dasyatidae, Carcharhinidae, Alopiidae and Sphyrnidae) and of the sooty tern Onychoprion fuscata of the Mozambique Channel from 2000 to 2010. Both fresh and accumulated beaks were used for identifying cephalopod prey. Cephalopods were important prey for twelve predators; swordfish Xiphias gladius had the highest cephalopod proportion; sooty tern (O. fuscata) and bigeye tuna (Thunnus obesus) had high proportions too. We recovered 23 cephalopod families and identified 38 species. Ten species from four Teuthida families (Ommastrephidae, Onychoteuthidae, Histioteuthidae and Ancistrocheiridae) and two Octopoda families (Argonautidae and Bolitaenidae) occurred very frequently in the stomach contents, while Sepiida were rare. Ommastrephidae were the most cephalopod food sources: the purpleback flying squid Sthenoteuthis oualaniensis was the most prevalent prey by far, Ornithoteuthis volatilis was important for eleven predators and few but large specimens of the neon flying squid Ommastrephes bartramii were recovered in the stomachs of swordfish in the Indian South Subtropical Gyre province only. Predators' groups were identified based on cephalopod prey composition, on depth in which they forage, and on prey size. Surface predators' diets were characterized by lower cephalopod diversity but greater average numbers of cephalopod prey, whereas the deep-dwelling predators (swordfish and bigeye tuna) preyed on larger specimens than surface predators (O. fuscata or yellowfin tunas Thunnus albacares). Our findings emphasized the usefulness of a community of marine predators to gain valuable information on the biology and the distribution of the cephalopod forage fauna that are discussed with regard to biogeographic province, marine predator, fishing gear to catch the large pelagic fishes, and size of the beaks recovered in the stomachs.  
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  Volume de collection Numéro de collection Edition  
  ISSN 0967-0645 ISBN Médium  
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  Notes Approuvé (up) pas de  
  Numéro d'Appel LL @ pixluser @ collection 291  
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Auteur Meddeb, M.; Niquil, N.; Grami, B.; Mejri, K.; Haraldsson, M.; Chaalali, A.; Pringault, O.; Hlaili, A.S. doi  openurl
  Titre A new type of plankton food web functioning in coastal waters revealed by coupling Monte Carlo Markov chain linear inverse method and ecological network analysis Type Article scientifique
  Année 2019 Publication Revue Abrégée Ecol. Indic.  
  Volume 104 Numéro Pages 67-85  
  Mots-Clés Bacterial multivorous food web; biogenic carbon; Coastal waters; continental-shelf; Ecology; ecosystem attributes; flow networks; Food web modeling; grazing impact; gulf; mediterranean sea; model analysis; Network analysis; Seasonal variations; seasonal-dynamics; trophic network; Trophic structure  
  Résumé Plankton food webs (PFW) typology is based on different categories of functioning, according to the dominant processes and the role played by heterotrophic bacteria, small vs large phytoplankton, and small vs large zooplankton. Investigating the structure and the function of planktonic food webs in two SW Mediterranean waters (inshore and marine sites) at four seasons, using inverse (LIM-MCMC) and ecological network (ENA) analyses, we identified a new type of food web, called the “bacterial multivorous food web”. This food web adds to the conventional trophic continuum as previously reported. The “bacterial multivorous food web” present in winter showed the lowest primary production among seasons, but highest bacterial production. Several food web ratios characterized this new typology e.g. picophytoplankton net primary production to total primary production varied from 0.20 to 0.28; bacterial to primary production ratio is higher than values reported in global scale (congruent to 1); bacterial net production to the potential protozoan prey net production was high (>0.2). In this special food web, carbon was mostly recycled, with a moderate fraction channeled to deep waters, which lead to a higher retention of carbon inside the ecosystem. This winter PFW also seemed to be the most organized, specialized, stable and mature, as related to common interpretations of ENA. The spring was characterized by herbivorous food web, with highest activity coinciding with low stability. Although less usual, the herbivorous pathway was also observed during summer, in inshore waters. The autumn food webs, which functioned as multivorous or microbial food webs, appeared to be stable and mature. Finally, our study demonstrates the usefulness of food web models derived ratios combined with ecological network analysis indices to conduct evaluation of the structure and functioning of ecosystems and potentially to support management decisions in marine environment.  
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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 1470-160x ISBN Médium  
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  Notes Approuvé (up) pas de  
  Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 2596  
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Auteur Cowart, D.A.; Durand, L.; Cambon-Bonavita, M.-A.; Arnaud-Haond, S. doi  openurl
  Titre Investigation of bacterial communities within the digestive organs of the hydrothermal vent shrimp Rimicaris exoculata provide insights into holobiont geographic clustering Type Article scientifique
  Année 2017 Publication Revue Abrégée PLoS One  
  Volume 12 Numéro 3 Pages e0172543  
  Mots-Clés alignment; chamber; deposits; diversity; Ecology; microbial community; mid-atlantic ridge; population; sequence data; sp nov.  
  Résumé Prokaryotic communities forming symbiotic relationships with the vent shrimp, Rimicaris exoculata, are well studied components of hydrothermal ecosystems at the Mid-Atlantic Ridge (MAR). Despite the tight link between host and symbiont, the observed lack of spatial genetic structure seen in R. exoculata contrasts with the geographic differentiation detected in specific bacterial ectosymbionts. The geographic clustering of bacterial lineages within a seemingly panmictic host suggests either the presence of finer scale restriction to gene flow not yet detected in the host, horizontal transmission (environmental selection) of its endosymbionts as a consequence of unique vent geochemistry, or vertically transmitted endosymbionts that exhibit genetic differentiation. To identify which hypothesis best fits, we tested whether bacterial assemblages exhibit differentiation across sites or host populations by performing a 16S rRNA metabarcoding survey on R. exoculata digestive prokaryote samples (n = 31) taken from three geochemically distinct vents across MAR: Rainbow, Trans-Atlantic Geotraverse (TAG) and Logatchev. Analysis of communities across two organs (digestive tract, stomach), three molt colors (white, red, black) and three life stages (eggs, juveniles, adults) also provided insights into symbiont transmission mode. Examining both whole communities and operational taxonomic units (OTUs) confirmed the presence of three main epibionts: Epsilonproteobacteria, Mollicutes and Deferribacteres. With these findings, we identified a clear pattern of geographic segregation by vent in OTUs assigned to Epsilonproteobacteria. Additionally, we detected evidence for differentiation among all communities associated to vents and life stages. Overall, results suggest a combination of environmental selection and vertical inheritance of some of the symbiotic lineages.  
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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 1932-6203 ISBN Médium  
  Région Expédition Conférence  
  Notes Approuvé (up) pas de  
  Numéro d'Appel MARBEC @ alain.herve @ collection 2085  
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Auteur Jacquet, C.; Mouillot, D.; Kulbicki, M.; Gravel, D. doi  openurl
  Titre Extensions of Island Biogeography Theory predict the scaling of functional trait composition with habitat area and isolation Type Article scientifique
  Année 2017 Publication Revue Abrégée Ecol. Lett.  
  Volume 20 Numéro 2 Pages 135-146  
  Mots-Clés Allometric theory; animal abundance; body-size; body-size distributions; complex food webs; coral-reef fishes; diversity; Ecology; evolution; Food web; global patterns; island biogeography; population-density; species richness; tropical reefs  
  Résumé The Theory of Island Biogeography (TIB) predicts how area and isolation influence species richness equilibrium on insular habitats. However, the TIB remains silent about functional trait composition and provides no information on the scaling of functional diversity with area, an observation that is now documented in many systems. To fill this gap, we develop a probabilistic approach to predict the distribution of a trait as a function of habitat area and isolation, extending the TIB beyond the traditional species-area relationship. We compare model predictions to the body-size distribution of piscivorous and herbivorous fishes found on tropical reefs worldwide. We find that small and isolated reefs have a higher proportion of large-sized species than large and connected reefs. We also find that knowledge of species body-size and trophic position improves the predictions of fish occupancy on tropical reefs, supporting both the allometric and trophic theory of island biogeography. The integration of functional ecology to island biogeography is broadly applicable to any functional traits and provides a general probabilistic approach to study the scaling of trait distribution with habitat area and isolation.  
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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 1461-023x ISBN Médium  
  Région Expédition Conférence  
  Notes Approuvé (up) pas de  
  Numéro d'Appel MARBEC @ alain.herve @ collection 2087  
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Auteur Abgrall, C.; Chauvat, M.; Langlois, E.; Hedde, M.; Mouillot, D.; Salmon, S.; Winck, B.; Forey, E. doi  openurl
  Titre Shifts and linkages of functional diversity between above- and below-ground compartments along a flooding gradient Type Article scientifique
  Année 2017 Publication Revue Abrégée Funct. Ecol.  
  Volume 31 Numéro 2 Pages 350-360  
  Mots-Clés biodiversity; community assembly; community ecology; disturbance; divergence; environmental gradient; feeding guilds; functional traits; microarthropod communities; null models; patterns; plant; plant communities; soil collembola; soil-plant interactions; species traits; trait convergence and trait divergence  
  Résumé 1. Trait-based approaches have the potential to reveal general and predictive relationships between organisms and ecosystem functioning. However, the mechanisms underlying the functional structure of communities are still unclear. Within terrestrial ecosystems, several studies have shown that many ecological processes are controlled by the interacting above-and belowground compartments. However, few studies have used traits to reveal the functional relationships between plants and soil fauna. Mostly, research combining plants and soil fauna solely used the traits of one assemblage in predictive studies. 2. Above-ground (plants) and below-ground (Collembola) compartments were sampled over a flooding gradient in northern France along the Seine River. First, we measured the effect of flooding on functional and taxonomic assembly within both communities. We then considered the linkages between plant and Collembolan species richness, community traits and assessed whether traits of both compartments converged at high flooding intensity (abiotic filtering) and diverged when this constraint is released (biotic filtering). 3. Species richness of both taxa followed the same bell-shaped pattern along the gradient, while a similar significant pattern of functional richness was only observed for plants. Further analyses revealed a progressive shift from trait convergence to divergence for plants, but not for Collembola, as constraints intensity decreased. Instead, our results highlighted that Collembola traits were mainly linked to the variations in plant traits. This leads, within Collembola assemblages, to convergence of a subset of perception and habitat-related traits for which the relationship with plant traits was assessed. 4. Synthesis. Using a trait-based approach, our study highlighted that functional relationships occur between above-and below-ground compartments. We underlined that functional composition of plant communities plays a key role in structuring Collembola assemblages in addition to the role of abiotic variables. Our study clearly shows that functional diversity provides a new approach to link the above-and below-ground compartments and might, therefore, be further considered when studying ecological processes at the interface between both compartments.  
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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 0269-8463 ISBN Médium  
  Région Expédition Conférence  
  Notes Approuvé (up) pas de  
  Numéro d'Appel MARBEC @ alain.herve @ collection 2091  
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