EFFECTS OF NET HAPA ON THE SURVIVAL OF CLARIAS GARIEPINUS (BURCHELL1S22) FRY FROM DIFFERENT BROODSTOCK SIZES

摘要

The effects of net hapa on the survival of fry from different broodstock sizes of Clarias gariepinus (Burchell 1822) was investigated in indoor aquaria for five weeks. Net hapa was incorporated to facilitate the separation of hatchlings from unhatchedeggs and shells. The use of incubating net with kakabans inside did not have any effect on incubation period, hatching and survival of the hatchlings. The eggs hatched normally within 24 hours at temperature range of 26 -27 deg C. percent (98%) hatchingwas achieved. Survival of hatchlings was enhanced because pollution due to decaying eggshells and unhatched eggs was eliminated. The survival rate of hatchlings from the three different broodstock sizes were 22.7%, 24.1% and 31.9% for 500g, 350g and 250g broodstocks respectively. There was significant difference (P < 0.05) in survival rate of hatchlings from different sizes of broodstocks. Fecundity obtained from the broodstocks was 42.972; 50,925 and 80,878 for250g, 350g and 500g broodstocks respectively.