[Article title missing]

Abstract

A study was made to investigate the effects of using carp pituitary extract (CPE), human chorionic gonadotropin (HCG), luteinizing hormone-releasing hormone analogues (LHRHa) and gonadotropin-releasing hormone analogues (GnRHa), with or without dopamine antagonist; domperidone (Dom). The results obtained demonstrated that the use of CPE, HCG, LHRHa or GnRHa together with dopamine antagonist (Dom) successfully induced ovulation in 100% of the experimental Clarias gariepinus broodfish. The highest ovulation index (70.76%) was observed in GnRHa plus Dom treated group. Broodfish of LHRHa treated group showed the lowest ovulation index (12.64%). The application of Dom plus GnRHa (T10) resulted in synchronization of ovulation (Latency period; 15.21 h) because the variation in this group was very low compared with other groups. Results of the fertilization percentage indicated that addition of dopamine antagonist (Dom) successfully increased fertilization rate on the GnRHa, HCG, and CPE-treated broodfish. Overall superiority of GnRHa plus Dom in spawning induction was proved by significant high hatchability, low deformed larvae and high survival rate percentages (81.9%, 2.1% and 89.9% respectively).

Keywords

• Breeding response
• African catfish
• Induced spawning
• Spawning performance
• Larval quality
• Hormones and hormonal analogues
• Dopamine antagonist