Comparative effects of GnRH-based drugs on induced spawning of the freshwater catfish, Heteropneustes fossilis

Abstract

Breeding experiments were conducted in Heteropneustes fossilis employing GnRH-based inducing agents like ovaprim, ovatide and wova-FH. The catfish responded well to ovaprim (0.40-0.55 ml/kg), ovatide (0.45-0.55 mg/kg) and wova-FH (0.50-0.60 mg/kg). Ovaprim gave better results in terms of fertilization and hatching success on low dose and latency period was also less as compared to ovatide and wova-FH. The overall performance of ovaprim was better when compared with the other two drugs. Among ovatide and wova-FH, the latter appeared to be better in spawning performance. The gonadotrophs (cynophils), distributed in the proximal pars distalis (PPD) of the pituitary gland, exhibited hyperactivity and degranulation in ovaprim, ovatide and wova-FH induced-bred H. fossilis suggesting release of the hormone (gonadotropin) in response to administration of the drugs.