Effects of Stocking Density on the Growth and Survival of Nile Tilapia (Oreochromis niloticus) Fry in Floating Cages in Togo

Aim/Background: To determine the optimal stocking density of juvénile Nile tilapia (Oreochromis niloticus) allowing better growth and survival of fish in floating cages on the Zio River Dam at Quality Agro-Fish Farm in Togo. Materials and Methods: Three stocking densities (D1=350 individuals, D2=500 individuals and D3=750 individuals) were considered in the 1 m3 floating cages. The experiment was carried out in triplicate for 45 days. The subjects were fed 4 times a day at a feeding rate of 8% of their biomass with the Raanan diet. Results and Conclusion: The average temperature was 27.11 ± 0.30°C, the average pH 7.18 ± 0, 16 and average dissolved oxygen of 5.2 ± 0.95 mg/L. The initial average was 2 ± 0.09 g, the final average weights were 27.33 ± 0.11 g (D1), 25.42 ± 0.21 g (D2) and 20.05 ± 0.14 g (D3). Mortality was inversely proportional to the experimentation time (p<0.05). The highest average weight and survival rate are obtained at the level of the lowest D1 density (27.33 g and 90.86%) (p<0.05). The feed index was higher with the high density D3 (3.59), but the lowest and the best feed index was obtained with the low density D1 (2.884) (p<0.05). Thus, the optimal density obtained was 350 fry in a floating cage of 1 m3.