Annual variation of the female Oplegnathus fasciatus in gonadosomatic index, sex hormone and biochemical composition.

In this paper,we studied the annual variation of the female Oplegnathus fasciatus in gonadosomatic index(GSI),sex hormone and biochemical composition.The results show that the average GSI of the female Oplegnathus fasciatus was between 0.77%-14.22%.its main propagation season was from May to June,and at this time the content of the GSI was between 8.50% and 20.56%.The estrogen 2(E2) concentration of serum has a sudden increase in May,but from July,it reduced sharply.The progesterone(P) concentration in serum increased gradually from January to June,and to the peak in June.The content of the crude protein in liver and ovary first increased,then decreased.and to the peak in May.During the ovarian development,The gonad index increased,and the concentration of the fat increased correspondingly,but it decreased in the liver.