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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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| Mahé, Kelig; Gourtay, Clemence; Bled--defruit, Geoffrey; Chantre, Celina; De Pontual, Helene; Amara, Rachid; Claireaux, Guy; Audet, C.; Zambonino-infante, Jose-luis; Ernande, Bruno. |
| Otolith shape is an efficient tool for fish stock discrimination. Therefore, it is crucial to identify the environmental parameters that could influence otolith morphogenesis and growth. Current global ocean warming negatively affects the production of polyunsaturated fatty acids (EPA and DHA) by phytoplankton and thus their availability in marine food webs. As EPA and DHA are essential nutrients for most fish species, their deficiency could affect many aspects of fish physiology, notably otolith morphogenesis. The goal of this study was to assess experimentally the combined influences of temperature (T) and dietary polyunsaturated fatty acid (PUFA) content on European seabass (Dicentrarchus labrax) otolith morphogenesis during early life stages. 300... |
| Tipo: Text |
Palavras-chave: N-3 polyunsaturated fatty acids; Otolith shape; Temperature effect; Elliptic Fourier descriptors; Multivariate mixed-effects models; Directional asymmetry. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00588/70054/68017.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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| Delerue-ricard, Sophie; Hanna, Stynen; Barbut, Léo; Morat, Fabien; Mahe, Kelig; Hablützel, Pascal I.; Hostens, Kris; Volckaert, Filip. |
| While otolith shape analysis can provide a valuable tool for discriminating between fish populations, factors which may influence otolith shape, such as the effect of size, directional asymmetry in growth, and local environmental conditions, are often unknown. Here, we analyzed differences in otolith shape across three size classes of age-0 common sole Solea solea L. from nursery grounds off the Belgian coast and in the Wadden Sea. Across size classes, form-factor decreased and roundness remained consistently high in both nursery grounds, while ellipticity increased in the Belgian nursery. Directional asymmetry between left and right otoliths measured by Fourier coefficients accounted for 0.96 and 7.2% of the variance when comparing otoliths overall, and... |
| Tipo: Text |
Palavras-chave: Early-life stages; Fourier coefficients; Nursery ground; Otolith shape; Small-scale spatial structure. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00453/56476/58866.pdf |
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| Costa,Rosa Maria Rodrigues da; Fabré,Nidia Noemí; Amadio,Sidinéia Aparecida; Tuset,Víctor Manuel. |
| ABSTRACT Using morphometric measurements and wavelets functions, the asterisci otoliths of curimatã, Prochilodus nigricans were analysed to identify the variation in shape and growth increment of individuals from Solimões, Japurá and Negro rivers of the Amazon basin, Brazil. The morphometric and morphological analyses did not reveal evidences of population segregation among rivers, but variations were found in the estimation of otolith growth increment. Also, the otolith shape showed a high variability between individuals, identifying four morphotypes. Morphotype 1 shows a more oval shape with a posterior zone clearly rounded; Morphotype 2 shows the posterior zone rounded, but the anterior end is more elongated; Morphotype 3 shows a completely different... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Amazon Basin; Growth increments; Morphotypes; Otolith shape; Phenotypes. |
| Ano: 2018 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252018000400215 |
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