OPTIMIZATION OF INDUCED OVULATION AND SPAWNING OF AFRICAN CLARIID CATFISH, Heterobranchus bidorsalis (Geoffroy-Saint-Hilaire, 1809) USING SYNTHETIC HORMONE

Résumé

In this study, induced spawning of Heterobranchus bidorsalis was optimized for artificial propagation. A single dose (ml) of synthetic hormone, Ovaprim" (Syndel, Canada), per kg body weight (bw) at 0.5, 0.75, 1 and 1.25 were administered on the broodstock. Ovulation and spermiation were achieved within the latency period of 14±1 h at 27±0.5 °C. Mean spawned eggs for doses of 1 ml/kg (56.77±8.92g) and 1.25 ml/kg (59.93±3.26g) gave significant production compared to 0.5 ml/kg (5.07±2.29g) and 0.75ml/kg (9.13±1.10g) (p<0.05). Percentages of fertility (72.33+2.52, 79.33±4.04, 84±4.58, 8214.36); hatchability (43.47±4.77, 61.73+10.02, 70.4+5.51, 68.57+12.78) and survival (47.37+3.16, 54.07±7.74, 64.67±4.63, 62.4±2.82) for the test doses of 0.5, 0.75, 1, 1.25 m/kg bw were recorded respectively at 28.5 +0.5 "C. The higher doses of 1 and 1.25 ml/kg bw showed significant difference compared to the lowest dose of 0.5ml/kg (p<0.05) while 0.75ml/kg was not significantly different to all other doses (p>0.05). Hatching occurred at 21 h in all the treatments. This study revealed reproductive dysfunction in H. bidorsalis and recommend a dose of Iml/kg bw for optimal induction using synthetic hormone Ovaprim.