Growth and Survival of Oreochromis niloticus (Linnaeus, 1758) Reared in Earthen Ponds with Aquatic Macrophytes

A feeding trial was conducted to determine tilapia (O. niloticus Linn, 1758) survival and growth under a plant-based feeding regime of fresh aquatic macrophytes (two duckweed: Lemna perpusilla (Torrey, 1843), Spirodela polyrrhiza (L.) Schleid., and one aquatic fern: Azolla pinnata (R.Br.). A diet of crushed snails (Pomacea canaliculata) served as Control. After eight months of culture, tilapia fed with A. pinnata, S. polyrrhiza, L. perpusilla and Control exhibited survival rates of 59.20, 46.40, 39.60 and 34.20, respectively. Best tilapia growth rates were recorded with S. polyrrhiza and A. pinnata macrophytes that had corresponding higher crude protein levels than L. perpusilla. Chi-square values at x20.95, v=2 (5.9<34.6) and x20.95, v=3 (7.81<70.43) indicated that tilapia could utilize aquatic macrophytes per se; however, poor growth (0.46 and 0.52g/day) and survival rates (34.20 ???????? 59.20 %) were observed due to varied crude nutrient profiles of the macrophytes. Tilapia fed with crushed snails in the Control showed highest mortality (65.80 %) and smallest average wet weight value (112.28g/fish) when compared to those reared in the three macrophyte-stocked ponds.