水産養殖研究開発ジャーナル

概要

Induced Breeding of African Mud Catfish, Clarias gariepinus (Burchell 1822), using Different Doses of Normal Saline Diluted Ovaprim

Olumuji OK *,Mustapha MK

African mud catfish, Clarias gariepinus is the most sought after farmed fish species in West Africa whose commercial breeding is done using expensive synthetic hormones one of which is ovaprim. The aim of the present paper is to reduce the cost of ovaprim by its dilution with normal saline in induced breeding of C. gariepinus. Induced breeding performance of Clarias gariepinus was evaluated using five different doses of normal saline diluted ovaprim at 0%, 25%, 75% and 100% while undiluted ovaprim served as the control. The ovaprim was administered at the rate of 0.5 ml for each treatment per kg body weight of the fish, represented as treatments A, B, C, D and E respectively. Mean weight of stripped eggs collected were 18.45 g, 17.50 g and 17.25 g in treatments A, B and C respectively with no significant difference (p<0.05) in the values. Spawning did not occur in D and E, thus no egg was collected. Percentage fertilization of the stripped eggs in treatments A, B and C were 88.70%, 87.50% and 77.38% respectively with treatment A showing significant difference (p<0.05) from B and C. Percentage hatchability from the stripped eggs were 56.58%, 54.07% and 57.75% for treatments A, B and C respectively with no significant difference (p<0.05) among the three treatments, while percentage survival of the fry were observed to be 40.27%, 40.87% and 42.52% in treatment A, B and C. There was no significant difference (p<0.05) in the survival rate among the treatments. Comparative cost benefit analysis between the control (undiluted ovaprim) and the different doses of normal saline diluted ovaprim shows that normal saline diluted ovaprim at 50% is the most cost effective. In conclusion, generic ovaprim with 50% normal saline will ensure spawning in Clarias gariepinus with high percentage hatchability of the eggs and survival of the fry.