ABSTRACT
In teleosts as in other vertebrates, pituitary gonadotropins (GtHs) are the major hormones that stimulate various ovarian activities. In most cases, however, GtH action on ovarian development is not direct, but through the biosynthesis of steroid hormones by the ovarian follicles that, in turn, mediates various stages of oogenesis including oocyte growth (vitellogenesis) and oocyte maturation (Nagahama, 1993).
