Abstract: The daily total metabolic rates were determined for 31 fish with closed respirometers. In addition, resting daily total metabolic rates were determined for 20fish by confining the fish into a cage within the respirometer. The fish weighed 72.9-133.3g and were fed different ration levels from starvation to 4% bw/day at 25℃. The specific dynamic action and activity metabolism changed with ration level in the form of a "V" shaped curve, with the lowest values at ration levels of about 1% and 2% bw/day,respectively. The energy expenditure of specific dynamic action was 22.14% of food energy.