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| Nikolic, Natacha; Puech, Alexis; Chouvelon, Tiphaine; Munschy, Catherine; Bodin, Nathalie; Brach-papa, Christophe; Potier, Michel; West, Wendy; Knoery, Joel; Zudaire, Iker; Dhurmeea, Zahirah; Degroote, Maxime; Cedras, Maria; Evano, Hugues; Bourjea, Jerome. |
| The GERMON project had several aims i) to understand the populations’ structure between albacore tuna southwest of the Indian Ocean and southeast Atlantic, ii) to determine the origin of juveniles observed in South Africa iii) to improve the understanding of the biology field (Size/Size and Size/Weight; reproduction and feeding area; trophic linkages) and iv) to initiate work on chemical analyzes and adaptation of the albacore species to its environment. These aims have been held and the results allow a better understanding of the management albacore. A general summary of results is presented in Part 9. |
| Tipo: Text |
Palavras-chave: Germon; Thunnus alalunga; Génétique; Stock; Structure; Connectivité; Chimie; Reproduction; Alimentation; Habitat; Albacore; Thunnus alalunga; Genetic; Stock; Structure; Connectivity; Chemical; Reproduction; Feeding behavior; Habitat. |
| Ano: 2015 |
URL: http://archimer.ifremer.fr/doc/00293/40461/39152.pdf |
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| Dhurmeea, Zahirah; Zudaire, Iker; Chassot, Emmanuel; Cedras, Maria; Nikolic, Natacha; Bourjea, Jerome; West, Wendy; Appadoo, Chandani; Bodin, Nathalie. |
| The reproductive biology of albacore tuna, Thunnus alalunga, in the western Indian Ocean was examined through analysis of the sex ratio, spawning season, length-at-maturity (L50), spawning frequency and fecundity. From 2013 to 2015, a total of 923 female and 867 male albacore were sampled. A bias in sex ratio was found in favor of females with fork length (LF) < 100 cm. Using histological analyses and gonadosomatic index, spawning was found to occur between 10°S and 30°S, mainly to the east of Madagascar from October to January. Large females contributed more to reproduction through their longer spawning period compared to small individuals. The L50 (mean ± standard error) of female albacore was estimated at 85.3 ± 0.7 cm LF. Albacore spawn on average... |
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| Ano: 2016 |
URL: https://archimer.ifremer.fr/doc/00362/47284/47261.pdf |
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| Sardenne, Fany; Diaha, N'Guessan Constance; Amande, Monin Justin; Zudaire, Iker; Couturier, Lydie; Metral, Luisa; Le Grand, Fabienne; Bodin, Nathalie. |
| In the Gulf of Guinea, bigeye Thunnus obesus (BET) and yellowfin tuna Thunnus albacares (YFT) are important for commercial fisheries and play a prominent ecological role as top predators. Using fatty acid profiles and carbon and nitrogen stable isotopes we examined their niche partitioning in this understudied region. 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 δ15N values and high proportions of mono-unsaturated fatty acids). The trophic position of YFT decreased slightly in the last 15 years (δ15N values decrease ~0.5 ‰) suggesting a change in epipelagic communities, as observed in the eastern Pacific Ocean. Ontogenic changes were limited to... |
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| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00436/54796/56254.pdf |
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