Use of saggital otolith shape analysis to discriminate Northeast Atlantic and Western Mediterranean stocks of Atlantic saury, Scomberesox saurus saurus (Walbaum)

The aim of this study was to test the hypothesis that Atlantic saury stocks from the Mediterranean Sea and northeastern Atlantic could be identified by means of saggital otolith shape. Saury is a pelagic fish inhabiting the north Atlantic that undertakes long migrations for feeding and reproduction. A combination of otolith shape indices and elliptic Fourier descriptors are analysed by multivariate statistical procedures. The results obtained show that saury from the Mediterranean Sea and northeastern Atlantic can be distinguished using otolith shape analysis. Whether or not those differences are due to genetic isolation is not tested here but possible drivers of the observed shape variation are explored.

► We tested the hypothesis of the presence of different stocks of Atlantic saury in the Mediterranean and northeastern Atlantic.
► We used a combination of otolith shape indices and elliptic Fourier descriptors.
► Those stocks can be distinguished by means of otolith shape analysis.
► We give a detail discussion of possible mechanism involved in the differences.