The Effect of Acute Stress on Post-Stress Oxygen Consumption Rate in Southern Catfish, Silurus meridionalis Chen

摘要

The post-stress oxygen consumption rate (VO2) was investigated in southern catfish (47.43±3.92 g) after different acute stress. The stress treatment were chasing for 2.5 min (CH), air exposure for 2.5 min (AE), 12.5°C coldwater bath for 2.5 min (CB), 2.5 min chasing plus 2.5 min air exposure (CA) and chasing at 12.5°C for 2.5 min (CC), respectively. All water and air temperature was 25°C except that of coldwater bath group. VO2 of all groups were increased immediately after stress (coldwater bath was increased a little slower) and slowly return to a pre-stress level. The VO2peak of CC group was significantly higher than those of all other groups (0.05). The VO2peak of CH group was significantly higher than that of CE group, while the latter was significantly higher than those of AE and CB groups (0.05). The VO2peak/VO2rest in both chasing groups (CH and CC) were significantly higher than those of other groups (0.05). The excess post-stress oxygen consumption rates (EPOC) of both chase groups were significantly larger that of CE group (0.05), while the latter was significantly larger than those of CB and AE groups (0.05). It suggested that: the VO2 response of southern catfish to chase was larger that air exposure and acute low-temperature stress, while air exposure and low-temperature stress might have little effects on VO2 response; Compared to chase effect, added air exposure treatment after chase lowered the post-stress VO2 response, while coldwater bath chase might elevated the post-stress VO2 response and as a sit-and-wait forager with poor aerobic and anaerobic capacity, the stress response of southern catfish was relatively lower.