Abstract

Duong Trinh

Oreochromis variabilis Boulenger (1906) is an indigenous and critically endangered fish species ofLake Victoria. It is among the species targeted for stock enhancement and restoration in Kenya. Such mass stock enhancement requires simple and easily applicable techniques to maximize its larviculture. This study investigated the growth potential of O. variabilisfrom fry to fingerling stages using diets formulated from locally available feed materials during the rearing period. Fish fry reared on formulated diets incorporating Rastrineobola argenteaPellegrin and Caridina niloticaRoux as protein source and cassava as basal feed gave higher growth and survival rates than those maintained on plankton live feed alone. There were significant differences in the final mean lengths and weights of fish fed the three treatment diets. Diet 3 gave significantly higher final mean lengths and weights than Diets 1 and 2. Growth rates of fish fry fed diets 2 and 3 regimens were significantly higher than those fed diet 1. The best food conversion ratio and condition factor were maintained in fry populations reared on Diet 3. The study concluded therefore that, viability of larviculture of O. variabilisusing simple formulated diets may be achieved, and that this result provides an important breakthrough in the propagation of its seed stock for mass culture towards stock enhancement and restoration to marketplace.