Profiles of gonadotropins and steroid hormone-like substances in the hemolymph of mud crab Scylla paramamosain during the reproduction cycle

To elucidate the role of gonadotropins-like substances in mud crab Scylla paramamosain, hemolymph samples were measured for concentrations of follicle stimulating hormone (FSH), luteinizing hormone (LH) and steroid hormones by enzyme-linked immunosorbent assay (ELISA). Hormonal concentration data were analyzed in association with the stages of gonadal development. ELISA has shown that in the female crab, the level of FSH reaches its peak in the early stage of ovary development, while estradiol and LH peaked during the late maturing stage of the ovary. In the male crab, testosterone and FSH culminated during the spermatid stage, and the level of LH peaked during the sperm stage. These results indicated that substances resembling the vertebrate FSH and LH are present in the hemolymph of S. paramamosain, and they may be involved in the development of the gonad.