Journal of Experimental Agriculture International

Fry management in aerated, none aerated aquarium and hapa system were determined in Fish Hatchery of Faculty of Agriculture, Shabu Lafia, Nasarawa State University Keffi, Nigeria to assess condition factor, percentage survival rate, increase in total body length and percentage weight gain. Two hundred hatchlings each of Clarias gariepinus were put into12.6 litres of water of 35 x 30 x 15 cm aquarium (with aerator and without aerator) and those of hapas (35 x 30 x 15 cm dimensions) were placed each in 1000 litres of water (aerated and none aerated) in 3 replicates. The fry were fed at 5% of their body weight with Artemia shell free as fry conventional food. The feeding was done four times daily at ¼ part of the 5% body weight for the period of sixteen days. Temperature (27.45±0.05ºC), pH (7.56±0.03); dissolved oxygen (8.20±0.03 mg/L), total alkalinity (15.36±0.03 mg/L) and free carbon dioxide (4.30±0.03 mg/L) monitored in the various treatments were not significantly different from each other. The Percentage weight gain (1117 and 1067), percentage survival rate (92.83 and 91.33), increase in total body length (1.07 and 1.07cm) and condition factor (11.99 and 11.44) of the fry in hapa system (aerated and none aerated respectively) were significantly (p<0.05) higher than those of aquaria treatments. The results of aerated and none aerated hapa treatments were not significantly different (P>0.05) from each other. The use of hapa as improved system for mass production of C. gariepinus fry is highly recommendable in the large body of water.