In vitro steroid secretion by ovarian follicles of the grouper Epinephelus marginatus

Many studies have employed in vitro incubation techniques to examine steroid production by the ovarian follicle of teleosts. The dusky grouper (Epinephelus marginatus, Perciformes, Serranidae) is a promising species for the Mediterranean aquaculture and restocking program in coastal areas. The reproductive pattern of the species (hermaphrodite protogynous) gives rise to several problems for broodstock management and controlled reproduction. Plasma steroids, expecially estradiol 17 β(E2), show high values also after ovulation in relation to asynchronous oocyte development. This study tests the effectiveness of human chorionic gonadotropin (hCG) in inducing in vitro E2 production by vitellogenic follicles from ovaries at different stages of maturity.