The Effects of Stocking Densities on Growth and Survival of Clarias gariepinus Burchell (1822) Fingerlings

189 Fingerlings were stocked at rate of 5, 10, 15, and 20 using a 30 liters capacity plastic tank in three replicates (E1 – E4 respectively) for period of six weeks which was carried out at Post Graduate Laboratory, Department of Zoology and Environmental Biology, Faculty of Science, Ekiti State University, Ado-Ekiti, Nigeria. The control experiment was stocked at 13 fingerlings per bowl, also in 3 replicates (E5). Feeding was done twice daily at 5% body weight. Water quality parameters monitored were pH, dissolved oxygen and temperature which fell within optimum limit for the growth of Clarias gariepinus. The initial mean weight and length of the fingerlings ranged from 0.82 - 0.9g and 4.81- 5.01cm respectively while the final mean weight and length of the fingerlings ranged from 14.61-17.93g and 11.96-13.16cm. Fingerlings stocked at 15 fingerlings per tank exhibited the lowest growth. Tank with 10 fingerlings per tank had the best specific growth rate. The stocking rate depends on the size of the container and it varies from 2 to 10 fingerlings per square meters (FAO, 2018). The survival rate for each group was recorded (Table 1). The growth and survival of African catfish (Clarias gariepinus) fingerlings reared at five stocking densities were evaluated. Fish of mean weight 0.1g were stocked in plastic tanks with three replicates for each treatment of 450 fish/m3. The fish were fed with 42% crude protein floating pellet at 5% body weight twice daily. The best growth performance and highest survival rate was obtained in E3 with mean weight gain of 17.06.±9.1g while E2 and E5 had 15.16±6.29g and 14.03±8.99g respectively. The specific growth rate was increasing daily; E1 to E5 has 6.86%, 6.94%, 5.06%, 6.67% and 6.77%, respectively. The survival rate was highest in E5 (80.77±6.44%) while E2 (80.00±6.32%), E4 (75.00±5.48%), E3 (71.11±8.07%) and E1 (63.33±8.16%) survival rate respectively. The mean weight gain, specific growth rate and survival rate were all dependent on stocking density. Therefore it can be recommended that for optimal growth of fingerlings and fast production of Clarias gariepinus should be stocked at maximum of 450 fish per cubic metre.