La Croissance de Liza ramada (Risso, 1825) dans la retenue du barrage de Sidi Saad (centre de Tunisie)

Abstract

The aim of this work is the estimation of the age and growth parameters of Liza ramada. Biological samples were collected monthly by the use of gillnets during two years 2007-2008. Scales were used to determine the age of Liza ramada. Relative linear growth does not vary with sex, the allometry is minorate for the relation between total and standard lengths. Positive allometric growth was observed between total length and fork length whereas the relative weight growth is isometric for both sexes. The study of absolute growth using the Von Bertalanffy model showed that the asymptotic length (L∞) is equal to 55.08cm, the growth coefficient K is 0.1542 and the theoretical age is - 1,731. 8 age groups were identified for the population of Liza ramada in Sidi Saad Dam.