Age et croissance de l'allache ou sardinelle ronde (Sardinella aurita Valenciennes, 1847) dans le Cap Bon (Tunisie)

Abstract

A new esseous part, the opercula bone, is used to estimate age of 2009 round sardine (Sardinella aurita Valenciennes, 1847) captured in the Cap Bon area. The period of sampling with a monthly rhythm, is spread out June 1994 at December 1995 and from June to September 1996. Th relation between the length of fish (LF) and the ray of opercula (RT) is LF= 22,25 RT 0,994 . The validation of age estimate method is carried out directly by the monthly follow-up of overage marginal lengthening and the percentage of individuals with marginal hyaline zone. This study showed that the round sardine has a double cycle of growth of the age-length shows that the females dominate in the majority of age groups the parameter of growth in length according to the model of Von Bertalanffy are estimated by direct enumeration of the hyaline zone and retrocalcul. The curves of growth obtained by employ retrocalculed data describe better the growth of the round sardine in Cap Bon area.