Effect of Repetitive Bouts of Exhaustive Exercise with Different Interval on Oxygen Consumption in Juvenile Southern Catfish

The paper is to investigate the repeating locomotive capacity of warmwater sit-and-wait southern catfish ( Silurus meridionalis Chen) and to test whether post-exercise recovery status has some effects on the next bout of exhaustive exercise metabolic recovery process. The oxygen consumption ( Vo2 ) of juvenile southern catfish ( 17.64～48.21 g, n=40) after repetitive bouts of exhaustive exercise (widely accepted hand-chasing method) with different intervals (10 min interval for a series of 3 bouts, 30 min interval for a series of 2 bouts and 24 h interval for a series of 2 bouts) was investigated at (25.0±1.0)℃ by using flow through respirometer made by laboratory of evolutionary physiology and behaviour (Patent No. ZL 200520010481.0 ). The resting oxygen consumption rate (Vo2rest) is (2. 39±0.13 )to(2.83±0.31 )mg·min-1·kg-1, the peak oxygen consumption rate (Vo2peak) is (8.36±0.26) to(10.39±0.44) mg·min -1·kg-1 and the magnitude of EPOC is (66.31 + 6.37 ) to (88.89±4.61) mg·kg-1. It is found that oxygen consumption can reach a relative stable status at 20～30 min after exhaustive exercise. The pre-exercise status can achieve after 24 h recovery. The recovery rates of post-exercise oxygen consumption are higher in the second and the third bouts of exhaustive exercise compared with the first bout in all interval treatments. However, there are no significant differences in peak oxygen consumption and EPOC magnitude among different bouts of exhaustive exercise. It suggests that exhaustive exercise can elicit the maximum oxygen consumption in juvenile southern catfish.