Effects of Tank Background Colour on Growth Performance and Feed Utilization of African Catfish Clarias Gariepinus (Burchell, 1822) Fingerlings

The performance of Clarias gariepinus (Burchell, 1822) fingerlings reared in white, green, blue, black and red coloured tanks was investigated. Each colour was tested in triplicate 1 m³ tanks with an initial stocking density of 100 fingerlings per tank (1.07 g). Fish were fed a commercial diet at 5% body weight per day for eight weeks. Fish weights were sampled every 2 weeks to adjust feeding rates. Tank colour had a significant effect (P < 0.05) on the overall performance of the fingerlings. Rearing in black tanks resulted in a higher daily feed intake (0.44 g) and better growth performance when compared to other tank colours, while the poorest performance was observed in blue and green tanks. Carcass protein and fat content at 8 weeks revealed a trend similar to that observed for growth. Also, serum glucose tests showed higher levels in light background tanks and were thought to be an indication of stress. Survival was not affected by tank colour. It was concluded that dark-coloured tanks such as black or red were better in comparison to light-coloured tanks for the rearing of African catfish fingerlings