Survival, growth and feed utilization of two clariid catfish (Clarias gariepinus, Burchell 1822 and Heterobranchus bidorsalis, Geoffroy, 1809) and their reciprocal hybrids

摘要

An experiment was conducted to determine the survival rate, fertilization rate, growth performance and feed utilization of two African clariid catfish Clarias gariepinus and Heterobranchus bidorsalis and their reciprocal hybrids. Four genetic crosses were made: C. gariepinus female x C. gariepinus male, H. bidorsalis female x H. bidorsalis male, C. gariepinus female x H. bidorsalis male and H. bidorsalis female x C. gariepinus male. The experiment was divided into two phases: artificial propagation of the fish species using a synthetic hormone and rearing the fry for 14 days, then further rearing the 14-day-old fry for an additional 35 days. In the first phase of the experiment, fry survival was estimated in each experimental unit (genetic cross); in the second phase, growth and nutrient utilization were investigated. Results revealed that the highest percentage of fertilization, hatching rate and percentage of survival was in the hybrid (H. bidorsalis female x C. gariepinus male) followed by the purebred H. bidorsalis (H. bidorsalis female x H. bidorsalis male). These three factors were significantly different (P < 0.05) among the genetic crosses. The purebred H. bidorsalis (H. bidorsalis female x H. bidorsalis male) had the highest percentage values of weight gain, specific growth rate and protein efficiency ratio and that these three parameters were significant (P < 0.05) among the four genetic crosses. Based on the results of this study, the purebred H. bidorsalis is recommended for commercial aquacultural practices.