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Auteur (up) Sardenne, F.; Diaha, N.'G.C.; Amande, M.J.; Zudaire, I.; Couturier, L.I.E.; Metral, L.; Le Grand, F.; Bodin, N. doi  openurl
  Titre Seasonal habitat and length influence on the trophic niche of co-occurring tropical tunas in the eastern Atlantic Ocean Type Article scientifique
  Année 2019 Publication Revue Abrégée Can. J. Fish. Aquat. Sci.  
  Volume 76 Numéro 1 Pages 69-80  
  Mots-Clés lipids; top predators; pacific-ocean; thunnus-albacares; stable-isotope analyses; western; vertical movements; bigeye tuna; vinciguerria-nimbaria; yellowfin tuna  
  Résumé In the Gulf of Guinea, bigeye tuna (Thunnus obesus; BET) and yellowfin tuna (Thunnus albacares; YFT) are an important part of commercial fisheries and play a prominent ecological role as top predators. Using fatty acid profiles and carbon and nitrogen stable isotopes, we examined their trophic niche partitioning in this understudied region. Trophic niche overlap was high (> 70%), similar to percentages in other ocean basins. BET occupied a higher trophic position than YFT and fed on deeper prey (high delta N-15 values and high proportions of monounsaturated fatty acids). The trophic position of YFT decreased slightly in the last 15 years (delta N-15 values decreased by similar to 0.5 parts per thousand), suggesting a change in epipelagic communities, as observed in the eastern Pacific Ocean. Ontogenic changes were limited to BET. For both species, the dietary proportion of the diatom marker 20:5(n-3) increased in the seasonal upwelling area, highlighting the influence of seasonal habitat on the diet of tuna. The relatively lipid-rich muscle (similar to 6% dry mass) of Atlantic tropical tuna suggests a richer diet in this region than that of Indian Ocean tropical tuna and (or) differences in energy allocation strategies.  
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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 0706-652x ISBN Médium  
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  Numéro d'Appel MARBEC @ alain.herve @ collection 2483  
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Auteur (up) Siegwalt, F.; Benhamou, S.; Girondot, M.; Jeantet, L.; Martin, J.; Bonola, M.; Lelong, P.; Grand, C.; Chambault, P.; Benhalilou, A.; Murgale, C.; Maillet, T.; Andreani, L.; Campistron, G.; Jacaria, F.; Hielard, G.; Arque, A.; Etienne, D.; Gresser, J.; Regis, S.; Lecerf, N.; Frouin, C.; Lefebvre, F.; Aubert, N.; Vedie, F.; Barnerias, C.; Thieulle, L.; Guimera, C.; Bouaziz, M.; Pinson, A.; Flora, F.; George, F.; Eggenspieler, J.; Woignier, T.; Allenou, J.-P.; Louis-Jean, L.; Chanteur, B.; Beranger, C.; Crillon, J.; Brador, A.; Habold, C.; Le Maho, Y.; Robin, J.-P.; Chevallier, D. doi  openurl
  Titre High fidelity of sea turtles to their foraging grounds revealed by satellite tracking and capture-mark-recapture: New insights for the establishment of key marine conservation areas Type Article scientifique
  Année 2020 Publication Revue Abrégée Biol. Conserv.  
  Volume 250 Numéro Pages 108742  
  Mots-Clés chelonia-mydas; Developmental area; Green turtle; growth; habitat use; Habitat use; Home range; home-range; immature green turtles; juvenile; lost years; movement patterns; multistate models; Residency; Seagrass; survival  
  Résumé Movement ecology studies are essential to protect highly mobile threatened species such as the green turtle (Chelonia mydas), classified as an endangered species by the IUCN. In 2019, the South Atlantic subpopulation has been downlisted to 'Least Concern', but the maintenance of this status strongly relies on the pursuit of research and conservation, especially on immatures, which contribute to the demographic renewal of this subpopulation. Identifying marine areas used by immatures is therefore crucial to implement efficient measures for the conservation of sea turtles in the Caribbean. We analysed data of capture-mark-recapture of 107 (out of 299) immatures recaptured at least once in Martinique, and satellite tracked 24 immatures to investigate their site fidelity and habitat use. Our results revealed a strong fidelity to foraging grounds, with mean residence times higher than 2 years, and with a high degree of affinity for specific areas within the coastal marine vegetation strip. Home ranges (95% kernel contour) and core areas (50% kernel contour) varied from 0.17 to 235.13 km(2) (mean +/- SD = 30.73 +/- 54.34 km(2)) and from 0.03 to 22.66 km(2) (mean +/- SD = 2.95 +/- 5.06 km(2)), respectively. Our findings shed light on a critical developmental area for immature green turtles in the French West Indies, and should help to refine Regional Management Units and reinforce the cooperative network aiming at ensuring conservation of the species at international scale.  
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  Langue English Langue du Résumé Titre Original  
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  Volume de collection Numéro de collection Edition  
  ISSN 0006-3207 ISBN Médium  
  Région Expédition Conférence  
  Notes WOS:000582432900003 Approuvé pas de  
  Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 2886  
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Auteur (up) Sirot, C.; Gronkjaer, P.; Pedersen, J.B.; Panfili, J.; Zetina-Rejon, M.; Tripp-Valdez, A.; Ramos-Miranda, J.; Flores-Hernandez, D.; Sosa-Lopez, A.; Darnaude, A.M. doi  openurl
  Titre Using otolith organic matter to detect diet shifts in Bardiella chrysoura, during a period of environmental changes Type Article scientifique
  Année 2017 Publication Revue Abrégée Mar. Ecol.-Prog. Ser.  
  Volume 575 Numéro Pages 137-152  
  Mots-Clés aquatic ecosystems; Bairdiella chrysoura; climate-change; Coastal ecosystem; fish otoliths; food-web; movement patterns; prey availability; Stable isotope analysis; stable-isotope analysis; survival; temporal-changes; terminos lagoon; Trophic ecology; Trophic interactions  
  Résumé Accurate knowledge on fish trophic ecology and its modifications is crucial for understanding the impact of global change on ecosystems. In this context, we investigated the value of the delta C-13 and delta N-15 of otolith soluble organic matter (SOM) for identifying temporal diet shifts in American silver perch Bairdiella chrysoura over a 30-yr period characterized by strong changes in its population size and habitats within the Terminos Lagoon (Mexico). We first compared the otolith SOM isotopic signatures from present-clay adults to those of muscle and the main local prey. Our results suggest that otolith SOM can be confidently extracted and analyzed for both present and past otoliths of this species. The mean otolith SOM signatures obtained (-15.92 +/- 1.35%, for delta C-13 and 9.38 +/- 0.93%, for delta N-15) were consistent with those of the diet as 85% of the individual signatures were included within the prey isotopic niche area. Moreover, this study supports a trophic enrichment factor between diet and otolith (TEFdiet-otolith) close to 0 for delta N-15, while for delta C-13, the TEFololith-muscle of +0.02% warrants further investigation. Then, we compared past and contemporary otolith SOM signatures to investigate temporal diet shifts in B. chrysoura. This showed that 613C and delta N-15 differed significantly between the past and present period even if the temporal shift remained relatively small (respectively +1.17%, and 0.55%). The present study substantiates the use of otolith SOM delta C-13 and delta N-15 as a proxy of fish present and past trophic position, opening the possibility for major progress in studies of temporal changes in food web ecology.  
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  Volume de collection Numéro de collection Edition  
  ISSN 0171-8630 ISBN Médium  
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  Numéro d'Appel MARBEC @ alain.herve @ collection 2172  
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Auteur (up) Sturrock, A.M.; Trueman, C.N.; Darnaude, A.M.; Hunter, E. url  doi
openurl 
  Titre Can otolith elemental chemistry retrospectively track migrations in fully marine fishes? Type Article scientifique
  Année 2012 Publication Revue Abrégée J. Fish Biol.  
  Volume 81 Numéro 2 Pages 766-795  
  Mots-Clés chemical fingerprint; geolocation; microchemistry; movement; natural; tag; trace metals  
  Résumé Otolith microchemistry can provide valuable information about stock structure and mixing patterns when the magnitude of environmental differences among areas is greater than the cumulative influence of any vital effects. Here, the current understanding of the underlying mechanisms governing element incorporation into the otolith is reviewed. Hard and soft acid and base (HSAB) theory is employed to explore the differences in chemical behaviours, distributions and affinities between elements. Hard acid cations (e.g. Mg2+, Li+ and Ba2+) tend to be less physiologically influenced and accepted more readily into the otolith crystal lattice but are relatively homogeneous in seawater. Soft acid cations (e.g. Zn2+ and Cu2+) on the other hand, exhibit more varied distributions in seawater, but are more likely to be bound to blood proteins and less available for uptake into the otolith. The factors influencing the geographical distribution of elements in the sea, and their incorporation into the otoliths of marine fishes are reviewed. Particular emphasis is placed on examining physiological processes, including gonad development, on the uptake of elements commonly used in population studies, notably Sr. Finally, case studies are presented that either directly or indirectly compare population structuring or movements inferred by otolith elemental fingerprints with the patterns indicated by additional, alternative proxies. The main obstacle currently limiting the application of otolith elemental microchemistry to infer movements of marine fishes appears to lie in the largely homogeneous distribution of those elements most reliably measured in the otolith. Evolving technologies will improve the discriminatory power of otolith chemistry by allowing measurement of spatially explicit, low level elements; however, for the time being, the combination of otolith minor and trace element fingerprints with alternative proxies and stable isotopic ratios can greatly extend the scope of migration studies. Among the otolith elements that routinely occur above instrument detection limits, Ba, Mn and Li were deemed the most likely to prove reliable geographic markers in marine species.  
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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 0022-1112 ISBN Médium  
  Région Expédition Conférence  
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  Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 462  
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Auteur (up) Suquet, M.; Cosson, J.; Donval, A.; Labbe, C.; Boulais, M.; Haffray, P.; Bernard, I.; Fauvel, C. url  doi
openurl 
  Titre Marathon vs sprint racers: an adaptation of sperm characteristics to the reproductive strategy of Pacific oyster, turbot and seabass Type Article scientifique
  Année 2012 Publication Revue Abrégée J. Appl. Ichthyol.  
  Volume 28 Numéro 6 Pages 956-960  
  Mots-Clés activation; crassostrea-gigas; fertilization; marine fish; motility; movement; pecten-maximus; respiration; scophthalmus-maximus; spermatozoa  
  Résumé This work assesses the present knowledge on Pacific oyster sperm biology in comparison to two marine fish species (turbot and seabass) whose sperm characteristics are well described. Sperm morphology mainly differs by the presence of an acrosome in Pacific oyster which is absent in both fish species. In turbot as in Pacific oyster, a sperm maturation process along the genital tract is observed. Sperm motility is triggered by changes in osmolality for seabass and turbot and in pH for Pacific oyster. However, complementary factors are involved to maintain sperm immotile in the genital tract. Sperm movement duration is very long in Pacific oyster (2024 h), compared to turbot (35 min) and seabass (4050 s). A high capacity of ATP regeneration is observed in Pacific oyster sperm, sustained by the limited changes in its morphology observed at the end of the swimming phase. Then, the total distance covered by spermatozoa is very different among the studied species (seabass: 2 mm, turbot: 12 mm, Pacific oyster: 1 m). Considering the main characteristics of sperm movement, the three studied species can be separated in two groups: the sprint racer group (seabass: high velocity and short distance covered) and the marathonian racer one (Pacific oyster: low velocity but covering long distances). To an intermediate extent, turbot sperm belongs to the sprint racer group. Then, the two different sperm movement strategies observed in the three species, are compensated by the behaviour of the breeders.  
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  Éditeur de collection Titre de collection Titre de collection Abrégé  
  Volume de collection Numéro de collection Edition  
  ISSN 0175-8659 ISBN Médium  
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  Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 701  
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