Application of ovaprim on varying sizes of male <i>Heterobranchus bidorsalis</i> to hand strip for milt

Abstract

Matured African catfish (Heterobranchus bidorsalis), size ranging from 500-1600g total body weight (TBW) were procured from private fish farm to Federal University of Technology, (F.U.T.) Minna indoor fish hatchery, maintained for 2 weeks and fed with 40 % crude protein commercial diet. The male breeders were hand stripped after application of (Ovaprim Overdose Inducement (OOI) at 1 ml, 1.25 ml and 1.5 ml to obtain milt to fertilize eggs. Mean fecundity was (402473±479.575a). The hatchlings bred from Conventional Method (CM) and OOI were maintained for 12 weeks to determine survival and mortality rates. Percentage hatching and volume of milt extracted differed significantly (P<0.05) between CM and OOI with highest volume of milt extracted from CM (0.86±0.017a). The male species of H. bidorsalis could be re-used for further genetic studies after milt stripping without killing but adequate feeding is necessary to hasten recovery and development of the gonads. The inducement by application of ovaprim at 1.25 ml was most effective at 12 h latency period and temperature of 24-280 C. This dosage is recommended for hand stripping of male breeders of H. bidorsalis for breeding.

Key Words: Artificial spawning, semen, Heterobranchus bidorsalis, synthetic hormone, breeding.