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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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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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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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