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Auteur (up) Brouwer, G.M.; Duijnstee, I. a. P.; Hazeleger, J.H.; Rossi, F.; Lourens, L.J.; Middelburg, J.J.; Wolthers, M. doi  openurl
  Titre Diet shifts and population dynamics of estuarine foraminifera during ecosystem recovery after experimentally induced hypoxia crises Type Article scientifique
  Année 2016 Publication Revue Abrégée Estuar. Coast. Shelf Sci.  
  Volume 170 Numéro Pages 20-33  
  Mots-Clés Bacteria; Benthic foraminifera; C-13 label; communities; Diet shifts; differential response; diversity; Hypoxia; in-situ; Intertidal; Macrofauna; Meiofauna; microphytobenthos carbon; population dynamics; Sediment  
  Résumé This study shows foraminiferal dynamics after experimentally induced hypoxia within the wider context of ecosystem recovery. C-13-labeled bicarbonate and glucose were added to the sediments to examine foraminiferal diet shifts during ecosystem recovery and test-size measurements were used to deduce population dynamics. Hypoxia-treated and undisturbed patches were compared to distinguish natural (seasonal) fluctuations from hypoxia-induced responses. The effect of timing of disturbance and duration of recovery were investigated. The foraminiferal diets and population dynamics showed higher fluctuations in the recovering patches compared to the controls. The foraminiferal diet and population structure of Haynesina germanica and Ammonia beccarii responded differentially and generally inversely to progressive stages of ecosystem recovery. Tracer inferred diet estimates in April and June and the two distinctly visible cohorts in the test-size distribution, discussed to reflect reproduction in June, strongly suggest that the ample availability of diatoms during the first month of ecosystem recovery after the winter hypoxia was likely profitable to A. beccarii. Enhanced reproduction itself was strongly linked to the subsequent dietary shift to bacteria. The distribution of the test dimensions of H. germanica indicated that this species had less fluctuation in population structure during ecosystem recovery but possibly reproduced in response to the induced winter hypoxia. Bacteria seemed to consistently contribute more to the diet of H. germanica than diatoms. For the diet and test-size distribution of both species, the timing of disturbance seemed to have a higher impact than the duration of the subsequent recovery period. (C) 2016 Published by Elsevier Ltd.  
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  Langue English Langue du Résumé Titre Original  
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  Volume de collection Numéro de collection Edition  
  ISSN 0272-7714 ISBN Médium  
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  Numéro d'Appel MARBEC @ alain.herve @ collection 2065  
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Auteur (up) Caro, A.; Escalas, A.; Bouvier, C.; Grousset, E.; Lautredou-Audouy, N.; Roques, C.; Charmantier, M.; Gros, O. url  doi
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  Titre Epibiotic bacterial community of Sphaeroma serratum (Crustacea, Isopoda): relationship with molt status Type Article scientifique
  Année 2012 Publication Revue Abrégée Mar. Ecol.-Prog. Ser.  
  Volume 457 Numéro Pages 11-27  
  Mots-Clés 16s ribosomal-rna; Crustacean; DGGE band pattern; Epibiotic biofilm; Molt cycle; Sphaeroma; fish; gastropod; gradient gel-electrophoresis; hydrothermal-vent; in-situ hybridization; mid-atlantic ridge; oxidizing bacteria; phylogenetic diversity; riftia-pachyptila; shrimp rimicaris-exoculata; urothoe-poseidonis  
  Résumé Sphaeroma serratum is a marine isopod species that inhabits seashores from Europe to West Africa. The individuals live under stones in direct contact with reduced sediments and harbour a diverse bacterial community on the cuticle of their pleopods. We investigated the diversity of these epibiotic bacteria on male (pubescent and senescent) and female specimens with electron microscopic observations and molecular tools. The microbial community of S. serratum was shown to be composed of at least 5 bacterial morphotypes observed on the pleopodal cuticle in all male specimens. Using fluorescence in situ hybridization, we identified 5 major phylogenetic groups (alpha-, beta-, gamma- and delta-Proteobacteria and Archaea) whereas denaturing gradient gel electrophoresis (DGGE) of PCR-amplified 16S rRNA gene fragments of epibiotic bacteria revealed 50 bands. The bacterial community associated with S. serratum seems more diverse than in other marine crustaceans, such as Rimicaris. The relative diversity of this bacterial community was also studied in relation to the molt cycle. The comparison of DGGE band patterns of several individuals from female, pubescent male and senescent male groups revealed that the bacterial community diversity was dependent on the sex and the age of the individuals and more generally on the molt status.  
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  Volume de collection Numéro de collection Edition  
  ISSN 0171-8630 ISBN Médium  
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  Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 564  
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Auteur (up) Chiarello, M.; Auguet, J.-C.; Bettarel, Y.; Bouvier, C.; Claverie, T.; Graham, N.A.J.; Rieuvilleneuve, F.; Sucre, E.; Bouvier, T.; Villeger, S. doi  openurl
  Titre Skin microbiome of coral reef fish is highly variable and driven by host phylogeny and diet Type Article scientifique
  Année 2018 Publication Revue Abrégée Microbiome  
  Volume 6 Numéro Pages 147  
  Mots-Clés bacterial communities; divergence; diversity; evolution; insights; life-history; Microbiota; mucus; patterns; Phylogenetic diversity; Phylogenetic signal; Phylosymbiosis; sequence data; Teleost; Tropical; vulnerability  
  Résumé Background: The surface of marine animals is covered by abundant and diversified microbial communities, which have major roles for the health of their host While such microbiomes have been deeply examined in marine invertebrates such as corals and sponges, the microbiomes living on marine vertebrates have received less attention. Specifically, the diversity of these microbiomes, their variability among species, and their drivers are still mostly unknown, especially among the fish species living on coral reefs that contribute to key ecosystem services while they are increasingly affected by human activities. Here, we investigated these knowledge gaps analyzing the skin microbiome of 138 fish individuals belonging to 44 coral reef fish species living in the same area. Results: Prokaryotic communities living on the skin of coral reef fishes are highly diverse, with on average more than 600 OTUs per fish, and differ from planktonic microbes. Skin microbiomes varied between fish individual and species, and interspecific differences were slightly coupled to the phylogenetic affiliation of the host and its ecological traits. Conclusions: These results highlight that coral reef biodiversity is greater than previously appreciated, since the high diversity of macro-organisms supports a highly diversified microbial community. This suggest that beyond the loss of coral reefs-associated macroscopic species, anthropic activities on coral reefs could also lead to a loss of still unexplored host-associated microbial diversity, which urgently needs to be assessed.  
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  Volume de collection Numéro de collection Edition  
  ISSN 2049-2618 ISBN Médium  
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  Numéro d'Appel MARBEC @ alain.herve @ collection 2421  
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Auteur (up) Cruaud, P.; Decker, C.; Olu, K.; Arnaud-Haond, S.; Papot, C.; Le Baut, J.; Vigneron, A.; Khripounoff, A.; Gayet, N.; Cathalot, C.; Caprais, J.-C.; Pignet, P.; Godfroy, A.; Cambon-Bonavita, M.-A. doi  openurl
  Titre Ecophysiological differences between vesicomyid species and metabolic capabilities of their symbionts influence distribution patterns of the deep-sea clams Type Article scientifique
  Année 2019 Publication Revue Abrégée Mar. Ecol.-Evol. Persp.  
  Volume 40 Numéro 3 Pages e12541  
  Mots-Clés calyptogena-magnifica; chemoautotrophic bacteria; cold seeps; community structure; deep-sea ecosystems; evolutionary relationships; guaymas basin; Guaymas Basin; gulf-of-california; hydrothermal vent clam; macrofaunal communities; marine ecology; pliocardinae bivalve; sulfide-rich sediments; sulfur storage; vesicomyid movements  
  Résumé This study provides an analysis of vesicomyid bivalve-symbiont community distribution across cold seep and hydrothermal vent areas in the Guaymas Basin (Gulf of California, Mexico). Using a combination of morphological and molecular approaches including fluorescent in situ hybridization (FISH), and electronic microscopy observations, vesicomyid clam species and their associated symbionts were characterized and results were analyzed in light of geochemical conditions and other on-site observations. A greater diversity of vesicomyids was found at cold seep areas, where three different species were present (Phreagena soyoae [syn. kilmeri], Archivesica gigas, and Calyptogena pacifica). In contrast, A. gigas was the only species sampled across the hydrothermal vent area. The same haplotype of A. gigas was found in both hydrothermal vent and cold seep areas, highlighting possible contemporary exchanges among neighboring vents and seeps. In either ecosystem, molecular characterization of the symbionts confirmed the specificity between symbionts and hosts and supported the hypothesis of a predominantly vertical transmission. In addition, patterns of clams could reflect potential niche preferences for each species. The occurrence of numerous traces of vesicomyid movements on sediments in the sites colonized by A. gigas seemed to indicate that this species might have a better ability to move. Furthermore, variation in gill sulfur content could reveal a higher plasticity and sulfur storage capacity in A. gigas. Thus, the distribution of vesicomyid species across the chemosynthetic areas of the Guaymas Basin could be explained by differences in biological traits of the vesicomyid species that would allow A. gigas to more easily exploit transient and punctual sources of available sulfide than P. soyoae.  
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  Volume de collection Numéro de collection Edition  
  ISSN 0173-9565 ISBN Médium  
  Région Expédition Conférence  
  Notes WOS:000472949800006 Approuvé pas de  
  Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 2605  
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Auteur (up) de Lorgeril, J.; Escoubas, J.-M.; Loubiere, V.; Pernet, F.; Le Gall, P.; Vergnes, A.; Aujoulat, F.; Jeannot, J.-L.; Jumas-Bilak, E.; Got, P.; Gueguen, Y.; Destoumieux-Garzón, D.; Bachère, E. url  doi
openurl 
  Titre Inefficient immune response is associated with microbial permissiveness in juvenile oysters affected by mass mortalities on field Type Article scientifique
  Année 2018 Publication Revue Abrégée Fish & Shellfish Immunology  
  Volume 77 Numéro Pages 156-163  
  Mots-Clés Host pathogen interaction; Innate immunity; Invertebrate; Mollusk; mortality; Total bacteria  
  Résumé Since 2008, juvenile Crassostrea gigas oysters have suffered from massive mortalities in European farming areas. This disease of complex etiology is still incompletely understood. Triggered by an elevated seawater temperature, it has been associated to infections by a herpes virus named OsHV-1 as well as pathogenic vibrios of the Splendidus clade. Ruling out the complexity of the disease, most of our current knowledge has been acquired in controlled experiments. Among the many unsolved questions, it is still ignored what role immunity plays in the capacity oysters have to survive an infectious episode. Here we show that juvenile oysters susceptible to the disease mount an inefficient immune response associated with microbial permissiveness and death. We found that, in contrast to resistant adult oysters having survived an earlier episode of mortality, susceptible juvenile oysters never exposed to infectious episodes died by more than 90% in a field experiment. Susceptible oysters were heavily colonized by OsHV-1 herpes virus as well as bacteria including vibrios potentially pathogenic for oysters, which proliferated in oyster flesh and body fluids during the mortality event. Nonetheless, susceptible oysters were found to sense microbes as indicated by an overexpression of immune receptors and immune signaling pathways. However, they did not express important immune effectors involved in antimicrobial immunity and apoptosis and showed repressed expression of genes involved in ROS and metal homeostasis. This contrasted with resistant oysters, which expressed those important effectors, controlled bacterial and viral colonization and showed 100% survival to the mortality event. Altogether, our results demonstrate that the immune response mounted by susceptible oysters lacks some important immune functions and fails in controlling microbial proliferation. This study opens the way to more holistic studies on the “mass mortality syndrome”, which are now required to decipher the sequence of events leading to oyster mortalities and determine the relative weight of pathogens, oyster genetics and oyster-associated microbiota in the disease.  
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  ISSN 1050-4648 ISBN Médium  
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  Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 2354  
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