OPTIMAL DIETARY-PROTEIN LEVEL FOR THE GROWTH OF JUVENILE GROUPER, EPINEPHELUS-MALABARICUS, FED SEMIPURIFIED DIETS

In a 50-day feeding trial, juvenile groupers, Epinephelus malabaricus, with an initial mean body weight of 3.79 +/- 1.17 g were fed isoenergetic semipurified diets containing six levels (24, 30, 36, 42, 48 and 54%) of protein. Dextrin was used to replace casein to achieve protein gradation. The dietary protein level that yielded maximum growth in E. malabaricus was 47.8% based on a broken-line model estimation of the weight pin results. The feed efficiency ratio and protein efficiency ratio decreased with the increased dietary protein levels. The survival of the fish was not affected by dietary protein levels. The fish fed the 42% protein diet had the lowest body lipid content.