The effects of food availability on the bioenergetics and the body composition of the cyprinidRasbora daniconius (Ham.) have been described. During the 15-day experimental period, fish in the weight range of 475 to 1660 mg were fed daily onTubifex tubifex for different durations. The food intake increased from 7·96±2·323 mg dry/fish/day for fish exposed to food for 2 hr to 11·57±0·757 mg dry/fish/day for fish fedad libitum diet. For the same series of fish, the feeding rate also increased. Growth of fish expressed as mg gain in dry weight/fish/day increased with increases in food intake. However, the food conversion efficiency was highly variable in relation to the daily food intake or feeding rate.