Abstract

In the present study, intramuscular injection of ovaprim-C was studied on the number of eggs/kg, fertilization rate and hatching percentage during April to June 2008 at Fish Seed Hatchery, Satyana Road, Faisalabad, Pakistan on Grass carp (Ctenopharyngodon idella). Fishes were spawned successfully following a single dose of injection of ovaprim-C (luteinizing hormone releasing hormone analogue) with 0.6 ml/kg for female and 0.2 ml/kg for male. Ova and milt were strippedsimultaneously and mixture was stirred for 15 to 30 s during which fertilization occurred. Hatching occurred within 18 to 22 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 = 0.926). 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 < 0.001) and can be used to estimate the absolute and relative fecundity with a fair amount of accuracy.

Key words: Fish, induced spawning, fecundity, ovaprim-C, Ctenopharyngodon idella.