The Role of Neurohypophysial Hormones in the Endocrine and Paracrine Control of Gametogenesis in Fish

Arginine vasopressin (AVP) and oxytocin (OXT) are neuropeptides traditionally recognized for their roles in the control of osmoregulation, blood pressure, lactation, and parturition in mammals. However, growing evidence suggests that AVPand OXT also regulate gonadal functions in teleost fish. Their expression in both male and female gonads, the presence of their receptors in ovaries and testes, and their interactions with steroids and other gonadal factors indicate a role in modulating gametogenesis and steroidogenesis via autocrine and paracrine mechanisms. Here, we review the current findings on AVP and OXT in teleost gonads, compared to the observed functions in mammals, emphasizing their systemic interactions within the hypothalamic-pituitary-gonadal (HPG) axis. While highlighting the roles of gonadal AVP and OXT in fish reproduction, we underscore the need for further research to unravel their complex multifactorial regulatory networks. Insights into the vasopressinergic system could enhance aquaculture practices by improving spawning success and reproductive efficiency.