Effect of Storage Period on the Efficacy of African Bull Frog Pituitary Extract for Induced Spawning of Clarias gariepinus

摘要

Acetone dried pituitary extract obtained from African bullfrog, Rana adspersa , was stored over a period of 16 weeks and used to induce spawning in the female Clarias gariepinus . Fresh pituitary extract was used as control. Fecundity and egg weight decreased with storage period. Fish injected with pituitary extract stored for 12 weeks and above had significantly (0.05) lower % fertilization and % hatching compared with fish stored for less than 4 weeks. The potency and viability of R. adspersa pituitary extracts decreased with storage periods. The results of this study indicated that stored R. adspersa pituitary hormone extract stored for 4 weeks gave the best result. Its yield was significantly different from that gotten using hormones stored for over 8 to 16 weeks period. It showed that the frog pituitary extract is still potent, viable and effective when stored for not more than 4 weeks. The R. adspersa pituitary hormone stored for 4 weeks can therefore be used as optimum storage period under the experimental conditions used in this study.