Mary A. OPIYO
The effect of tank background colour and stocking density on growth rates and survival of Nile tilapia (Oreochromis niloticus) fry (0.32 g) were investigated. The fish were reared in aquari-um with blue, black and clear backgrounds at two stocking densities of 2 fish L-1 and 4 fish L-1. The outside walls and bottoms of each aquarium were painted to achieve one of two colours (blue and black), while noncoloured (clear) aquarium served as a control. The fish were fed a commercial diet (40% crude protein) at a daily rate of 5% of their body weight twice a day for 70 days. The best growth rates, weight gain, specific growth rate, food conversion ratio and survival were achieved in larvae reared under 2 fish L-1 stocking density in the blue back-ground. Fish performance was significantly (P
