Available online at www.jpsscientificpublications.com Life Science Archives (LSA) ISSN: 2454-1354 Volume – 2; Issue - 1; Year – 2016; Page: 365 - 375 ©2015 Published by JPS Scientific Publications Ltd. All rights reserved Review Article POST OVULATION MANIPULATION IN FEW FRESHWATER CATFISH J. Godwin Christopher*, School of Biosciences and Technology, Vellore Institute of Technology, Vellore – 632014, India. Abstract The objective was to evaluate the influence of the hormonal induction on the reproductive activity of female freshwater catfish. Control of fish reproduction in captivity is essential for commercial aquaculture. The fish reproductive cycle consists in the growth (gametogenesis) and maturation phase (oocyte maturation), and they are controlled by the reproductive hormones of the brain, pituitary and gonad. Manipulations of reproductive function in cultured fish uses exogenous hormone preparations which act at different levels of the gonad, or the use of synthetic agonists of gonadotropin-releasing hormone. After hormonal induction of maturation, brood stock should spawn spontaneously, however, for many species it is necessary to adapt gamete collection and fertilization in vitro. The main factors that may have significant consequences on gamete quality - mainly on eggs - and the latency period between hormonal injection and stripping for in vitro fertilization. Article History Received : 05.01.2016 Revised : 11.01.2016 Accepted : 18.01.2016 Key words: Oocyte maturation, Induced breeding, Artificial insemination, Sperm to egg ratio, Gamete quality and Catfish. 1. Introduction Fish are the largest phylum of living vertebrates, with around 30,000 fish species out of approximately 50,000 vertebrate species (Nelson, 2006). Fishes inhabit almost every aquatic environment on the planet, presenting an enormous variation in temperature, salinity, oxygen, and other chemical and physical water properties. The existence of these diverse reproductive strategies has important implications for finfish culture and brood stock management. Fish egg quality can be defined as the ability of the egg to be fertilized and subsequently develop into a normal embryo. The egg's potential to produce a viable and normal embryo can be *Corresponding author: J. Godwin Christopher Tel.: +91-9976605776 E-mail: godwinj@vit.ac.in affected by many environmental and biological factors acting at various steps of the oogenetic process (Devlin and Nagahama, 2002). The determinism of egg quality has also been shown to be under the influence of genetic factors (FAO, 2007). While the effects of many experimental factors have been studied, the mechanisms by which they trigger egg quality losses are far less documented. Hormones of maternal origin supplied to the embryo by the egg also have a significant effect on embryonic development as shown by several studies. In fish, it is often useful or necessary to control the timing of spawning or induce the ovulatory process. These techniques are used for biotechnical, experimental or economical reasons to obtain out of season egg production and synchronous egg production within a group of females or, for some species, to obtain eggs from