A total of sixty juvenile Oreochromis niloticus (Nile tilapia) were fed three species of aquatic weed, namely Azolla filiculoides (water fern), Elodea sp. and Pistia stratiotes (water lettuce) to determine which of the weeds will be selectively consumed, and preferred of all. A control group of twenty Nile tilapia was fed compounded feed. The selectivity of the weeds was observed based on their utilization as food source, and Azolla filiculoides was found to be highly utilized, followed by Elodea sp. and the roots of Pistia stratiotes. The growth response of the fish to the diets was found to be highest for fish fed compounded feed followed by Azolla filiculoides and Elodea sp., while Pistia stratiotes produced a negative growth trend. It is therefore postulated that Azolla filiculoides and Pista sp. are good feedstuffs for O. niloticus especially when used together with other feedstuff
