Morphological differences between two populations of the little tunny,euthynnus alletteratus (Rafinesque,1810) in Tunisian Waters (Central Mediterranean Sea)

In this study we analyzed possible differences among the specimens of the little tunny euthynnus alletteratus (rafinesque,1810) inhabiting tunisian waters. our investigation based on the analysis of morphological characteristics of euthynnus alletteratus from two distant sampling sites (mahdia and zarzis) along the tunisian coast using 11 morphometric and 3 meristic characters in order to investigate the morpholgical variation among them. uni and multivariate analysis of variance of 64 adult specimens showed significant differences among the means of the two studied sites for 8 standardized morphometric measurements out of 11 characters. the principal component analysis (pca),scatter plot of individual component score between pc1 and pc2 showed two morphometric groups. the linear canonical variate analysis (cva),the overall assignments of individuals into their original groups was 95.13%. the morphometric and meristic analysis were fully congruent and confirm the occurrence of two potential differentiated groups. this variation of morphometric and meristic characters in specimens from two populations could be caused by differences in genetic structure or environmental conditions. copyright 2017 zoological society of pakistan.