Laura G. Tiu, Carl D. Webster and James H. Tidwell, Aquaculture Research Center, Kentucky State University, Frankfort, KY 40601

Abstract. Growth, survival, and body composition were evaluated in two feeding trials using juvenile hybrid bluegill (Lepomis cyanellus X L. macrochirus). In Experiment 1, hybrid bluegill (20 g) were stocked into 1.250m³ cages at a rate of 300 fish/cage and fed diets containing 35, 40, 44, or 48% protein for 12 weeks. No significant differences (P < 0.05) in individual length, individual weight, specific growth rate (SGR), condition factor (K), and feed conversion ratio (FCR) were found among treatments and averaged 13.4 cm, 47.4 g, 1.02%/day, 1.96, and 4.06, respectively. In Experiment 2, fifteen hybrid bluegill (15 g) were stocked into 110-L aquaria and fed one of four diets containing 28, 32, 36, or 38% protein for 10 weeks. Fish fed a diet containing 38% protein had higher (P < 0.05) percentage weight gain (265%) than fish fed diets containing 28% (203%) and 32% (219%) protein, but were not significantly different (P >0.05) compared to fish fed a diet containing 36% protein (251%). Results from these studies indicate that hybrid bluegill can be fed a practical diet containing 35-36% protein. Further refinement of diet formulation may allow producers to reduce diet and production costs.