A comparative study on the effect of stocking density and feeding regime on the growth rate ofTilapia cameronensisandOreochromis niloticus(Cichlidae) in fishculture in Cameroon

Abstract

Tilapia cameronensis fry were reared in plastic tanks and earthen ponds at the Fishculture Research Station, Foumban, Cameroon. Their growth rate was compared to that of the Nile tilapia (Oreochromis niloticus) fry, reared under identical conditions. Different treatments were applied (food or organic manure only; food combined with organic manure); physical-chemical variables were quantified. The best growth rate was recorded for fry reared in tanks receiving both food and organic manure: the daily weight gain of T. cameronensis fry in tanks was nearly half of that of the Nile tilapia, while in ponds T. cameronensis showed a higher growth rate than O. niloticus (0.19 g.d−1 versus 0.13 g.d−1). The growth rate decreased with increasing stocking density. In another experiment Tilapia cameronensis fry were reared in aquaria at different stocking densities in a recirculated water system. The highest growth rate was recorded for fry stocked at 0.5 fish.l−1 and receiving daily a feeding rate of 15% of the total biomass. This growth rate was comparable to that of fry stocked at 0.25 fish.l−1 receiving the 5% feeding rate. The latter had the lowest FCR. Mortality due to aggressive interactions increased with decreasing stocking density.