Induction of maturation and ovulation by pimozide-LHRH analogue treatment and resulting high quality egg production in the Asian catfish, Clarias batrachus (L.)

Abstract

In Clarias batrachus (250–310 g), collected from nature in the early spawning season, simultaneous injections of pimozide (a dopamine antagonist) and the luteinizing hormone-releasing hormone analogue (LHRHa), des-Gly 10 [D-Ala 6]-LHRH ethylamide, caused a high rate of ovulation (85.7%), while injections of either pimozide or LHRHa alone or the vehicle medium did not. The ovulated fish produced an average of 21.15±2.6 g eggs with a very high hatching rate (91.88±1.51%) and a high yield of normal fry (85.5±3.1%). The results suggest that the combination can be used as a simple and efficient method for inducing ovulation in the catfish.