Comparative efficacy of different inducing agents on breeding performance of a near threatened cyprinid Osteobrama belangeri in captivity.

Abstract

An experiment was conducted to breed a near threatened Cyprinid Osteobrama belangeri in captivity through hormonal inducement. Carp pituitary extract (CPE) and three different GnRH based synthetic hormones viz., Ovaprim, Ovatide and Wova-FH were used as inducing agents. Experiment was conducted following a Completely Randomized Design (CRD). The brooders were injected with different doses of hormones and kept in the breeding hapas at 2:1 male to female ratio. All the inducing agents induced the fishes to breed, whereas no breeding was observed in the control set. Spawning success rate varied depending on the rate of inducement and the type of inducing agent used. CPE at a dose of 9 mg kg−1offemale and 3 mg kg−1of male as well as the synthetic hormones at 0.5 ml kg−1of female and 0.2 ml kg−1of male brooders were found to be effective in inducing the fishes to breed in captivity. Efficacy of the synthetic hormones was significantly higher than that of CPE (P < 0.05). Dose of hormone apparently affected the percentage of fertilization, egg output, hatching rate and spawn production. Administering an over-dose of the inducing agents caused early milting resulting in poor fertilization and under-dosing might cause late inducement in males. The present breeding protocol is simple and can be taken up by small breeders. It will be helpful in aquaculture and conservation of O. belangeri.