Some biological parameters of the red mullet, Mullus barbatus L., 1758, from the Gulf of Tunis

The red mullet, Mullus barbatus L. 1758 is one of the main target species of the trawl fishing industry along the continental shelf off the Tunisian Gulf. The reproductive biology of this species has been studied based on statistical sampling conducted between February 2003 and January 2004. Length frequency distribution according to sex revealed that the females were highly represantative in the majority of size classes. Monthly variations in the gonadosomatic index (GSI) showed that males spawn from April to July, whereas the reproductive activity of the females occurs in the late spring and summer (May and July). The estimated lengths at maturity (Lm50) were 13.87 cm for males and 13.94 cm for females. According to the length-weight relationship, positive allometry was confirmed for males, females and pooled sexes.