Food consumption and growth of two piscivorous fishes, the mandarin fish and the Chinese snakehead

Rates of maximum food consumption and growth were determined for immature mandarin fish Siniperca chuatsi (47·2—540·2 g) and Chinese snakehead Channa argus (45·0—546·2 g) at 10, 15, 20, 25, 30 and 35) C. The relationship between maximum rate of food consumption ( C max), body weight ( W ) and temperature ( T ) was described by the multiple regression equations: In C max=?4·880+0·597 In W +0·284 T ?0·0048 T ² for the mandarin fish, and In C max=?6·718+ 0·522 In W +0·440 T ?0·0077 T ² for the Chinese snakehead. The optimum temperature for consumption was 29·6) C for the mandarin fish and 28·6) C for the Chinese snakehead. The relationship between growth rate ( G ), body weight and temperature was ln( G +0·25)=?0·439?0·500 ln W +0·270 T ?0·0046 T ² for the mandarin fish, and ln( G +0·25)=?6·150+ (0·175?0·026 T ) ln W +0·571 T ?0·0078 T ² for the Chinese snakehead. The weight exponent in the growth–weight relationship was ?0·83 for the mandarin fish, but decreased with increasing temperature for the Chinese snakehead. The optimum temperature for growth was 29·3) C for the mandarin fish, but tended to decrease with increasing weight for the Chinese snakehead, being 30·3) C for a 45-g fish, and 26·1°C for a 550-g fish.