Abstrato

Local Variability in the Sagittae Otolith Shape of Mugil cephalus from the Sea of Tabarka and the Dam of Nebeur in Tunisia

Maïssa Khedher, Abderraouf Ben Faleh, Manel Fatnassi, Manel Rebaya, Abdellah Chalh, Jean- Pierre Quignard and Monia Trabelsi

The otolith shape analysis is a powerful tool to use in studies focusing to marine biology and ecology in various aquatic areas (marine, dam and lagoons) as well the identification of fish stocks of species. In the present study, the sagittae otoliths were used to compare specimens of Mugil cephalus collected from two Tunisian regions, Tabarka Sea and Nebeur Dam. We analyzed the shape variation by sex (male and female) and otolith side (left and right) in order to discriminate the stock structure of Mugil cephalus. Discriminant analysis demonstrated statistical differences in the otolith shape between specimens of two sampling sites, which indicate a clear population differentiation. Also, these results were confirmed by highly statistically significant difference between otoliths’ shape (left and right) for both sexes. Hence, the shape variability of otolith between these two sampling sites is probably correlated with local environmental factors.