Induced Spawning and Hatching Rate of Grass Carp (Ctenopharyngodon idella) by Using a Single Intramuscular Injection of Ovaprim at Demar Fish Hatchery Dhamtari (C.G), India

The study was carried out at Demar fish hatchery, Dhamtari (Chhattisgarh), India. Intramuscular injection of ovaprim was studied on the number of eggs/kg, fertilization rate and hatching percentage during May to July 2010 on Grass carp (Ctenopharyngodon idella). Fishes were spawned successfully by a single dose of injection of ovaprim (luteinizing hormone releasing hormone analogue) with 0.5 ml/kg for female and 0.2 ml/kg for male. Ova and milt were stripped simultaneously and mixture was stirred for 20 to 30 s during which fertilization occurred. Hatching occurred within 16 to 20 h after fertilization. Experiment was conducted in circular spawning tank with 2 m diameter. Regression analysis was applied to assess the body weight dependence of absolute fecundity (total ripe eggs in the ovary) and relative fecundity (number of eggs/kg). It was observed that body weight has positive influence on absolute fecundity (r = 0.930). Equations were developed to describe these relationships. If it is impossible to determine the absolute and relative fecundity, then these parameters can be determined from the body weight. The equations of these parameters are highly significant (P < 0.002) and can be used to estimate the absolute and relative fecundity with a fair amount of accuracy.