Effect Of Ph On The Growth Performance Of Heterobranchus Bidorsalis (♂) X Clarias Gariepinus (♀) Hybrid Juveniles

Abstract

Twelve plastic basins each filled with 6 litres of dechlorinated tap water at pH 6 7 (control), 75 and 8 such that each pH treatment was replicated three timesin a Latin square design were used for the study. The tanks were randomly stocked with 10 four-week-old Clarias gariepinus (♀) x Heterobranchus bidorsalis (♂) hybrid juvenies (mean weght 3.32 ± 0.05 g) and fed 30.25% crude protein diets for five weeks. Fish growth was measured by weighing the juveniles every week and the weight differences, specific growth rate (SGR) and food conversion ratio (FCR) determined. Fsh raised at pH treatment 7.0 recorded signfcantly higher weght gan (P < 005) than other pH treatmentsWeght gan of fish rased at pH 6.0 was however not different (P > 005) from that offish raised on pH 8.0 treatment. There was significant diference (P < 0.05) in the SGR of the juveniles raised at pH 6 and pH 8. There was no sgnificant difference (P > 0.05) between the SGR of fsh rased at pH 7 and pH 7.5 bu there was sgnificant difference between the SGR of fish raised at pH 7 and fish raised at other treatments. Fish showed reduced growth when raised at pH 6 andpH 8 and positive growth when raised at pH 7 and 7.5 though there was no significant dfference (P> 005) in FCR o fish cultured at all pH treatments. Our results showed that the optimal pH rangeor raisng the hybrid catish juvenies was between 7.0 – 7.5 pH.

Keywords: Heterobranchus bidorsalis x Clarias gariepinus hybrid, Optimal pH range

Animal Research International Vol. 4 (1) 2007 pp. 639-642