This study was designed to determine the effect of using serially diluted Buserelin acetate (Suprecur®), which is a luteinizing hormone-releasing hormone analogue (LHRHa) with dopamine antagonist (Motilium®) on the latency period, fecundity, percentage fertilization and percentage hatching of Clarias gariepinus. Treatments administered include 50ug/l, 40ug/l, 20ug/l and 10ug/l of Suprecur® in tandem with 5mg/kg of Motilium®. Metrics obtained include egg numbers, latency period, fertilization rate, hatching rates, and survival to first feeding. The results obtained demonstrated that the use of Suprecur® (LHRHa) together with dopamine antagonist (Motilium®) successfully induced ovulation in the experimental Clarias gariepinus broodfish. The highest fecundity was from the treatment T40 There was no significant difference in egg weights stripped from each treated group. The application of 50 µg/kg of Suprecur® with 5mg/kg of Motilium® resulted in earlier synchronization of ovulation (Latency period; 12 hours). Results of the fertilization percentage indicated that an increase in the dose of LHRHa did not significantly affect the fertilization rate in treated groups of broodfish . Overall superiority of 50 µg/kg of Suprecur® plus 5mg/kg of Motilium® in spawning induction was proved by significantly high hatchability, 83.56%. Broodstock used for the 40µg/kg dose had the highest fecundity. There was no significant correlation (p>0.05) between the water quality parameters and the breeding parameters. In conclusion, the result obtained clearly indicates an overall superiority of using 50 µg/kg of Suprecur ® together with 5mg/kg of Motilium® to induce spawning with regard to the recorded high hatchability percentage.
Keywords: Hormone; ovulation; fertilization; hatchability; hypophysation; synthesis.