In this study, analyses of 87 biometric parameters and of genetic variation of the cytochrome b gene show that
A. boyeri populations from shallow waters of Tunisian Islands (Kerkennah) belong, in spite their marine habitat, to the lagoonal
group. Moreover, in all the phylogenetic analyses, the sequences of these marine atherines constitute with the lagoon
ones a clade strongly statistically supported. Moreover, in accordance with ecological rules, vertebral numbers of
wild individuals increased with latitude for all the Atherina species, but for A. boyeri a low decrease of vertebral number
in its more septentrional distribution area is suggested. In addition, the lower values are found for species living in particular
habitats, rocky sea beds or lagoons for respectively punctated and lagoonal fish, and a rapid decrease of mean vertebral
number by latitude has been found for lagoon fish.