The control of reproduction in finfish species through GnRH treatments

Abstract

Fish in captivity can show some dysfunctions, at different levels, in the physiological processes of reproduction, due to  the lack of synthesis or release of gonadotropins (GtHs) by hypophysis. As a consequence, a worsening of quality and  quantity of spawned gametes, or a lack of egg and sperm spawning, can be observed. The farmers can act on fish repro-  ductive cycle manipulating the environmental parameters of rearing, the diet, the genetics or using GnRH treatments.  Nowadays, they are used mainly GnRH, synthesized in laboratory as analogues. These releasing factors, naturally pro-  duced by hypothalamus, let to overcome the technological and biological limits of the “traditional” hormonal treatments  with hCG, being more effective, cheaper and easily available on market. This article makes a historical survey of the con-  ditioning treatments for fish reproduction and also considers the future perspectives of these treatments, examining the  topics that research will have to focus, in order to make these treatments common worldwide, in any hatchery and for  each farmed  species of finfish. 

Keywords

• Fish species, Reproductive cycles, GnRHa, GnRHA releasing systems