Abstract
This study, on the biology of the Lessepsian fish Sphyraena chrysotaenia, aims to determine some growth and reproduction parameters. Thus, breeding season extends from August to November. The hepato-somatic index (HSI) and the condition factor (CF) variations show that the liver is the organ more responsible for the process of mobilization of the energizing reserves during the sexual cycle. Sexual maturity is reached at 195 mm TL for females and 197.1 mm for males at 2 years. Regarding sex ratio, males outnumbered females by 1:0.84, which was a significant departure from the hypothetical 1:1. Sex ratio ranged from 0.4 to 1.48, showing a temporal pattern over the study period. The length-weight regression was W = 1.02 10−2 TL2.8195 for females and W = 8.1 10−3 TL2.8316 for males, without any significant difference between sexes. Overall, 798 specimens were distributed in six age classes. The maximum observed age was five years for both sexes. Back-calculations of total length-at-age were satisfactorily adjusted to the Von Bertalanffy growth model, and the relative equation was L 28.55 (1 – e −0.311(t + 1.655)) for females and L 26.41 (1 – e −0.3662(t + 1.54)) for males.