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Auteur Manna, L.R.; Villeger, S.; Rezende, C.F.; Mazzoni, R.
Titre (up) High intraspecific variability in morphology and diet in tropical stream fish communities Type Article scientifique
Année 2019 Publication Revue Abrégée Ecol. Freshw. Fish
Volume 28 Numéro 1 Pages 41-52
Mots-Clés approach reveals; assemblages; body-size; community ecology; competition; ecology; functional diversity; functional traits; habitat use; originality; plasticity; rainforest stream; savannah stream; specialisation; specialization; traits
Résumé Functional diversity of fish communities has been measured according to (a) interspecific variability, assuming that intraspecific variability is negligible, or (b) morphological differences, as good descriptors of complex functions, such as diet. These two assumptions have been scarcely tested on the individual level, especially in species-rich tropical ecosystems. Here, we adapted intraspecific specialisation (ISpe) and intraspecific originality indices (IOri) to assess complementary components of intraspecific variability. Next, we applied these indices to evaluate the intra- and interspecific variability of morphological and diet traits in two contrasting Brazilian stream-dwelling fish assemblages (rainforest and savannah). We also compared correlations between morphology and diet at the individual and species level to test whether accounting for intraspecific variability increases the predictability of diet due to morphological differences. Significant contributions of intraspecific variability to differences between fish were revealed for morphology and diet. Intraspecific variability in the diet was higher than that in morphology in both assemblages. The ISpe was positively correlated to IOri in the diet of both ecosystems. The morphological-dietary relationships were significant but weak at both individual and species levels. Our findings highlight the importance of measuring individual variability and accounting for complementary components of the intraspecific variability (ISpe and IOri). Importantly, we showed that the variability in morphology does not predict diet variability at both intra- and interspecific levels. Thus, high intraspecific variability in morphology and diet challenges the use of functional traits measured at the species level to describe the functional diversity of different fish assemblages.
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ISSN 0906-6691 ISBN Médium
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Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 2472
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Auteur Cox, S.L.; Authier, M.; Orgeret, F.; Weimerskirch, H.; Guinet, C.
Titre (up) High mortality rates in a juvenile free-ranging marine predator and links to dive and forage ability Type Article scientifique
Année 2020 Publication Revue Abrégée Ecol. Evol.
Volume 10 Numéro 1 Pages 410-430
Mots-Clés antarctic fur seals; behavior; bio-logging; body condition; early life; foraging ecology; juvenile mortality; Mirounga leonina; mirounga-leonina; population; regularization paths; southern elephant seal; southern elephant seals; survival; survival analyses; variable selection; weaning mass
Résumé High juvenile mortality rates are typical of many long-lived marine vertebrate predators. Insufficient development in dive and forage ability is considered a key driver of this. However, direct links to survival outcome are sparse, particularly in free-ranging marine animals that may not return to land. In this study, we conduct exploratory investigations toward early mortality in juvenile southern elephant seals Mirounga leonina. Twenty postweaning pups were equipped with (a) a new-generation satellite relay data tag, capable of remotely transmitting fine-scale behavioral movements from accelerometers, and (b) a location transmitting only tag (so that mortality events could be distinguished from device failures). Individuals were followed during their first trip at sea (until mortality or return to land). Two analyses were conducted. First, the behavioral movements and encountered environmental conditions of nonsurviving pups were individually compared to temporally concurrent observations from grouped survivors. Second, common causes of mortality were investigated using Cox's proportional hazard regression and penalized shrinkage techniques. Nine individuals died (two females and seven males) and 11 survived (eight females and three males). All but one individual died before the return phase of their first trip at sea, and all but one were negatively buoyant. Causes of death were variable, although common factors included increased horizontal travel speeds and distances, decreased development in dive and forage ability, and habitat type visited (lower sea surface temperatures and decreased total [eddy] kinetic energy). For long-lived marine vertebrate predators, such as the southern elephant seal, the first few months of life following independence represent a critical period, when small deviations in behavior from the norm appear sufficient to increase mortality risk. Survival rates may subsequently be particularly vulnerable to changes in climate and environment, which will have concomitant consequences on the demography and dynamics of populations.
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ISSN 2045-7758 ISBN Médium
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Notes WOS:000502011200001 Approuvé pas de
Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 2698
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Auteur Nguyen-Kim, H.; Bouvier, T.; Bouvier, C.; Hai, D.N.; Lam, N.N.; Rochelle-Newall, E.; Baudoux, A.C.; Desnues, C.; Reynaud, S.; Ferrier-Pages, C.; Bettarel, Y.
Titre (up) High occurrence of viruses in the mucus layer of scleractinian corals Type Article scientifique
Année 2014 Publication Revue Abrégée Environmental Microbiology Reports
Volume 6 Numéro 6 Pages 675-682
Mots-Clés abundance; bacteria; communities; diversity; ecology; gradient gel-electrophoresis; level physiological profiles; microbial; reef; release; water
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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ISSN 1758-2229 ISBN Médium
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Notes <p>ISI Document Delivery No.: AU6GU<br/>Times Cited: 1<br/>Cited Reference Count: 51<br/>Nguyen-Kim, Hanh Bouvier, Thierry Bouvier, Corinne Hai Doan-Nhu Lam Nguyen-Ngoc Rochelle-Newall, Emma Baudoux, Anne-Claire Desnues, Christelle Reynaud, Stephanie Ferrier-Pages, Christine Bettarel, Yvan<br/>EC2CO CORINE Project; TOTAL Foundation; French Institute of Research for Development (IRD)<br/>This work was supported by the EC2CO CORINE Project, the TOTAL Foundation and the French Institute of Research for Development (IRD). We thank Telesphore Sime-Ngando, Didier Debroas, Pham The Thu, Chu Van Thuoc, Sonia Monteil and Delphine Bonnet for their participation in the CORINE mission in Vietnam, their assistance in diving, field operations and technical support during the cruise, and Sebastien Villeger for his advice on statistical analysis. We are also very grateful to Michel Galey, Alexandre Portier and all the staff from Whale Island Resort for their hospitality and help during our stay.<br/>Wiley-blackwell<br/>Hoboken</p> Approuvé pas de
Numéro d'Appel MARBEC @ alain.herve @ collection 1170
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Auteur Leprieur, F.; Colosio, S.; Descombes, P.; Parravicini, V.; Kulbicki, M.; Cowman, P.F.; Bellwood, D.R.; Mouillot, D.; Pellissier, L.
Titre (up) Historical and contemporary determinants of global phylogenetic structure in tropical reef fish faunas Type Article scientifique
Année 2016 Publication Revue Abrégée Ecography
Volume 39 Numéro 9 Pages 825-835
Mots-Clés biodiversity hotspots; climate-change; community ecology; coral-reefs; damselfishes teleostei; evolutionary origins; genetic-structure; indo-pacific; latitudinal diversity gradient; species richness
Résumé Identifying the main determinants of tropical marine biodiversity is essential for devising appropriate conservation measures mitigating the ongoing degradation of coral reef habitats. Based on a gridded distribution database and phylogenetic information, we compared the phylogenetic structure of assemblages for three tropical reef fish families (Labridae: wrasses, Pomacentridae: damselfishes and Chaetodontidae: butterflyfishes) using the net relatedness (NRI) and nearest taxon (NTI) indices. We then related these indices to contemporary and historical environmental conditions of coral reefs using spatial regression analyses. Higher levels of phylogenetic clustering were found for fish assemblages in the Indo-Australian Archipelago (IAA), and more particularly when considering the NTI index. The phylogenetic structure of the Pomacentridae, and to a lower extent of the Chaeotodontidae and Labridae, was primarily associated with the location of refugia during the Quaternary period. Phylogenetic clustering in the IAA may partly result from vicariance events associated with coral reef fragmentation during the glacial periods of the Quaternary. Variation in the patterns among fish families further suggest that dispersal abilities may have interacted with past habitat availability in shaping the phylogenetic structure of tropical reef fish assemblages.
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Langue English Langue du Résumé Titre Original
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Volume de collection Numéro de collection Edition
ISSN 0906-7590 ISBN Médium
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Numéro d'Appel MARBEC @ alain.herve @ collection 1633
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Auteur Toussaint, A.; Beauchard, O.; Oberdorff, T.; Brosse, S.; Villeger, S.
Titre (up) Historical assemblage distinctiveness and the introduction of widespread non-native species explain worldwide changes in freshwater fish taxonomic dissimilarity Type Article scientifique
Année 2014 Publication Revue Abrégée Global Ecology and Biogeography
Volume 23 Numéro 5 Pages 574-584
Mots-Clés Beta diversity; differentiation; freshwater fish; homogenization; macroecology; partitioning; turnover
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ISSN 1466-8238 ISBN Médium
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Numéro d'Appel MARBEC @ alain.herve @ collection 1174
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