Reproductive biology of Argyrosomus regius (Asso, 1801) inhabiting the south eastern Mediterranean Sea, Egypt

The aim of the current work is to study the reproductive biology of Argyrosomus regius (Asso, 1801) collected from the wild catch of Egyptian Mediterranean coast. This is to give a clear image about the spawning season, length at first sexual maturity, and to identify gonadal maturation using histological analysis in respect to steroid hormone concentration throughout 1 year period. The present results revealed that wild meagre has a protracted spawning season starting in April and ending in July. The length at first sexual maturity of female fishes started at larger lengths than males 47 cm for females and 45 cm for males. By comparing calculated gonadosomatic index (GSI) to histological analysis it is clear that male fishes started gonadal maturation before female fishes. Plasma steroid level showed fluctuations in its mean concentration as Testosterone showed massive increase during male gonadal maturation and ripening stages. Plasma Progesterone and Estradiol levels displayed different patterns in their mean concentration during developmental stages throughout the maturation period of ovaries and testes. They showed significant declination in mature fish plasma followed by an insignificant increase during nearly ripe and ripening periods.The current data showed that wild meagre displays a gonochoristic group-synchronous oocyte maturation pattern. More investigation on this important fish species is recommended to establish a breeding protocol for aquaculture purpose.