NECESSITY OF DIETARY-CHOLESTEROL FOR THE FRESH-WATER PRAWN

The cholesterol requirement of the freshwater prawn Macrobrachium rose nbergii, in terms of daily requirement (mg cholesterol/kg body weight/ day), was assessed by the feeding experiment using casein-based diets with graded levels of supplemental cholesterol and by the analysis of carcass cholesterol. The prawn grew on a diet without supplemental cho lesterol, and the body cholesterol was increased even in the prawn fed a cholesterol-free diet. However, the highest weight gain was obtaine d on the diet with 0.1% supplemental cholesterol. These results indica ted that the juvenile M. rosenbergii was capable of de novo cholestero l synthesis in contrast to other prawn species but required a dietary source of cholesterol for the maximum growth. When the diet containing 0.1% supplemental cholesterol was given to the prawn, it was suggeste d that dietary cholesterol was retained in the body at the rate of 0.0 65 mg/g body weight/day and the apparent body retention efficiency of dietary cholesterol was 83%. Based on the above results, when true fee ding levels (or % ingestion of diet) are 7 to 3% of body weight, optim um dietary cholesterol levels for the juvenile M. rosenbergii are sugg ested to be 0.11 to 0.26% in diet under the experimental conditions ad opted.