Sexual cycle and fecundity of sea bass Dicentrarchus labrax of Annaba's gulf. Investigations on the reproduction of Dicentrarchus labrax in the gulf of Annaba indicate that the sex-ratio is globally in favor of females (S.R.= 43,0%; P < 0,01) and varies over time and as a function of body length. Examination of monthly evolution of gonado-somatic index, hepato-somatic index and shows adiposity places the reproduction season between December and March and affirms that reproduction involves the mobilisation of energetic reserves contained in the liver and mesentery. The first sexual maturity is more precocious in males (23,5 cm and 2 years old) than in females (30,1 cm and 3 years old), in which the relative fertility is rather low (147 eggs.g-1). A survey of oocyte dynamics shows that there is only a single spawn each year. |