The effects of sea temperature and food availability in fish reproduction: boarfish Capros aper as an indicator species.

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Identifying populations of the Blue Jack Mackerel (Trachurus picturatus) in the Northeast Atlantic by using geometric morphometrics and otolith shape analysis

Publication . Vasconcelos, Joana; Vieira, Ana R.; Sequeira, Vera; González, José A.; Kaufmann, Manfred; Gordo, Leonel Serrano

The population structure of the blue jack mackerel (Trachurus picturatus, Osteichthyes, Carangi dae), in the northeast Atlantic is still unknown. To identify any dis tinct population units, three areas were selected: waters off Madeira, Peniche (mainland Portugal), and the Canary Islands. Knowledge of population structure is an aspect of the population dynamics of a spe cies that is essential to effectively assess the existence of stocks and manage fisheries. In this study, geo metric morphometrics and otolith shape analysis were successfully applied for population identifica tion. Multivariate analysis of vari ance (MANOVA) revealed no body shape differences between males and females in each area studied, and therefore the sexes were com bined for the analysis. The results of the discriminant analysis showed that a low misclassification occurred among areas; 78.0% of individuals were correctly classified. MANOVA performed on the otolith normalized elliptic Fourier descriptors revealed significant areal differences, but no difference between sexes. An overall classification success of 73.3% in the canonical discriminant analysis was achieved. These results indicate the usefulness of both otolith and body shape analysis for differentiation of blue jack mackerel stocks from the northeast Atlantic and indicate the existence of at least three distin guishable populations of this specie

2017Journal article

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