Investigating otolith mass asymmetry in six benthic and pelagic fish species (Actinopterygii) from the Gulf of Tunis

Otolith mass asymmetry can significantly affect the vestibular system functionalities; usually, X values of vary between −0.2 and + 0.2 (−0.2 < 0.2). These change during a fish life therefore they are not related to total length. We collected 404 specimens from Gulf Tunis, including three pelagic species: Sardina pilchardus (Walbaum, 1792) (74 otolith pairs), Trachurus mediterraneus (Steindachner, 1868) (66 Chelon auratus (Risso, 1810) (60 pairs) benthic Gobius niger Linnaeus, 1758 (77 Mullus barbatus Trachinus draco (67 pairs). The relation length was first calculated compared, then evaluated. comparison species showed significant difference ( P 0.05), where absolute mean value does exceed critical (0.2) for all studied species. No has been found magnitude in both specimens. Environmental factors have an indirect effect on somatic growth accretion. this study be due environments.