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.