A total of 27 Clarias gariepinus breeders (18 males and 9 females) with the female body weight ranging from 750g to 2100g were used to observe the spawning activity of the fish. The study was conducted to determine the reproductive variables of C. gariepinus, such as gonadosomatic index, fecundity, fertility, and hatchability. The pituitary glands (PG) collected from C. gariepinus, Cyprinus carpio, and Oreochromis niloticus were used for induction. The spawning fecundity of C. gariepinus injected with C. gariepinus pituitary gland extract oscillated at 79, 510 eggs, while the recipient of C. carpio pituitary gland extract yielded 106, 550. However, the fish administered with O. niloticus pituitary gland extract did not respond to the induction since there was no egg yield during the stripping procedure. The gonadosomatic index of C.gariepinus and C.carpio induced fish were 12% and 12.23%, respectively. In terms of fertilization rate, the C. gariepinus (88.4%) is higher than C. carpio (76.6%). Concerning the hatchability rate, it was observed that after 31 hours of incubation, the eggs were hatched with a rate of 58.6% and 67.6% for the C. gariepinus and C. carpio induced fish, respectively. Statistical analysis shows no significant difference both in hatchability rate and fertility rate, which implies that both C. gariepinus and C. carpio PG could be used as effective inducing agents in the spawning activity of African Catfish, C. gariepinus.
Fabio C. Ruaza (Fri,) studied this question.