Conserved and Divergent Features of Reproductive Neuroendocrinology in Teleost Fishes
Publisher Summary This chapter summarizes the reproductive neuroendocrinology of teleosts, emphasizing both conserved and divergent features. Despite phylogenetic distance, fishes share with tetrapods a number of common characteristics with respect to neuroendocrine control of the reproductive axis. Fishes synthesize luteinizing hormone and follicle-stimulating hormone, which regulate early gametogenesis, steroidogenesis, and ovulation/spermiation. Pituitary gonadotropic secretion is regulated by gonadotropin-releasing hormone, which is, in turn, controlled by a number of neurotransmitters and neuropeptides, including kisspeptins. Gonadal steroids also act at the hypothalamus to regulate secretion of gonadotropins. The chapter outlines that in fishes the role of the environment in sexual differentiation and the diversity of reproductive strategies, leading to multiple variations in a common general mechanism, is of great importance.