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| Mahe, Kelig; Evano, Hugues; Mille, Tiphaine; Bourjea, Jerome. |
| Swordfish (Xiphias gladius) is an oceanic-pelagic species currently fully exploited by several fisheries in the Indian Ocean, with suspicion of overexploitation in the southwest, but without a clear understanding of the real stock structure within this Ocean. Population structure of the Indian stock was studied in the western Indian Ocean using 395 individual samples collected from 2009 to 2014. Sagittal otoliths of the fish have been removed and shape analysis performed on these calcified pieces. Otolith morphometrics data and normalized Elliptical Fourier Descriptors (EFDs) were then extracted automatically by the dedicated imageanalysis system TNPC. Preliminary, side effect was tested by Redundancy analysis (RDA) combined to permutation tests on 91... |
| Tipo: Text |
Palavras-chave: Xiphias gladius; Otolith shape; Fourier descriptors; Stock discrimination; Indian Ocean. |
| Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00269/37980/36068.pdf |
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| Mahe, Kelig; Oudard, Clemence; Mille, Tiphaine; Keating, James P; Gonçalves, Patricia; Clausen, Lotte Worsøe; Petursdottir, G; Rasmussen, H; Meland, E; Mullins, E; Pinnegar, Jk; Hoines, A; Trenkel, Verena. |
| Information on stock identification and spatial stock structure provide a basis for understanding fish population dynamics and improving fisheries management. In this study otolith shape analysis was used to study the stock structure of blue whiting (Micromesistius poutassou) in the northeast Atlantic using 1693 samples from mature fish collected between 37°N and 75°N and 20°W and 25°E. The results indicated two stocks located north and south of ICES Divisions VIa and VIb (54°5 to 60°5 N, 4° to 11°W). The central area corresponds to the spawning area west of Scotland. Sampling year effects and misclassification in the linear discriminant analysis suggested exchanges between the northern and southern stocks. The results corroborate previous studies... |
| Tipo: Text |
Palavras-chave: Micromesistius poutassou; Forme de l’otolithe; Descripteurs de Fourier; Discrimination de stock; Nord-est de l’Océan atlantique.; Micromesistius poutassou; Otolith shape; Fourier descriptors; Stock discrimination; Northeast atlantic. |
| Ano: 2016 |
URL: https://archimer.ifremer.fr/doc/00334/44508/44202.pdf |
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| Mahe, Kelig; Evano, Hugues; Mille, Tiphaine; Muths, D.; Bourjea, Jerome. |
| Swordfish Xiphias gladius is an oceanic-pelagic species. Its population structure in the Western Indian Ocean was studied from the shape of the sagittal otoliths of 391 individuals collected from 2009 to 2014. Normalised elliptical Fourier descriptors (EFDs) were extracted automatically using TNPC software. Principal components analysis (PCA) conducted on EFDs showed no significant effect of side (i.e. left or right otolith). Consequently, all 391 sagittal otoliths were used to identify stocks among six geographical areas: Reunion Island, Mozambique Channel, Rodrigues, South Africa, Madagascar South and Sri Lanka. To investigate the effects of sex, sampling year, sampling season, lower jaw fork length or geographical area on variations in otolith shape,... |
| Tipo: Text |
Palavras-chave: Connectivity; Fourier descriptors; Morphometric markers; Sagittal otoliths; Stock discrimination. |
| Ano: 2016 |
URL: http://archimer.ifremer.fr/doc/00354/46527/46411.pdf |
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