The growth performance and survival rate of monosex Heterobranchus longifilis juveniles were examined. A total of 144 Heterobranchus longifilis juveniles were stocked in eighteen (18) concrete tanks at stocking density of sixteen (16) fishes per tank of 2 by 2 metre square in flow-through and stagnant water systems triplicated for fifty six (56) days. Mixed sex tanks of Heterobranchus longifilis served as the control. The mean initial weight was taken as 1.22±0.00g while the highest mean final weights were 7.86±0.12 a g and 6.34±0.02 c g for monosex females and males in stagnant culture THFS and THMS. Heterobranchus longifilis also showed highest Specific growth rate of 3.80±0.03g in the female stagnant system THFS. Food conversion ratio and Feed conversion efficiency were highest in female flow-through tank THFF and stagnant tank THFS with values 4.09±0.00 a and 16.83±0.08 a. Performance Index showed Heterobranchus longifilis mixed sex performed better than the flow-through monosex culture of Heterobranchus longifilis. High survival rate 95.83±4.17% was seen in female stagnant tanks THFS. Lowest survival rates were recorded in the monosex flow-through and stagnant systems of Heterobranchus longifilis. Condition factor K was greater than 1 throughout the study for both species. Values were closely similar for the specie in monosex and mixed sex culture. Water quality parameters were at normal ranges for freshwater culture, throughout the study. It is recommended that concrete flow-through and stagnant systems be used for monosex and mixed sex culture of Heterobranchus longifilis.

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Matured African catfish (Clarias gariepinus), size ranging from 200-1600g total body weight (TBW) were procured from a private fish farm and transported in perforated 50 litre water holding capacity jerry can to Federal University of Technology, (F.U.T.) Minna, Bosso campus indoor fish hatchery and maintained for 2 weeks. They were fed with 40 % crude protein commercial diet with good water quality management before being used for breeding. 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. Fecundity increased with body weight and hence larger fish had higher fecundity and differed significantly (P<0.05) from each other. Mean fecundity was (280744±302). 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±0.006a). CM gave the highest percentage survival (75.20 %) though not significantly different (P>0.05), and with ±SEM (2.232) and SD (2.923) of the bred fingerlings that were managed for 12 weeks.The male species of Clarias gariepinus could be re-used for further genetic studies after milt stripping. Milt can be stripped without killing the male but proper and 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 10 h latency period and temperature of 25-290 C. This treatment or dosage is hence recommended for hand stripping of male breeders of Clarias gariepinus for breeding.