驱赶和空气暴露对南方鲇耗氧率和呼吸频率的影响

在25℃条件下对不同驱赶时间(0、0.5、1、2.5和5 min)和空气暴露(0、2.5、5、10和20 min)南方鲇(Silurus meridionalis)幼鱼(22.11～79.52 g)恢复过程中的耗氧率(VO)和呼吸频率(Vf)进行了测定。实验发现:经驱赶和空气暴露处理后,实验鱼耗氧率和呼吸频率立即显著上升(P<0.05),然后缓慢回落至稳定水平;对于驱赶逆境胁迫,0.5 min处理能诱导最大耗氧率峰值(约170 mg/h),2.5 min处理能诱导最大运动后过量氧耗(EPOC)(约35 mg);对于空气暴露逆境胁迫,5 min处理能诱导最大耗氧率峰值(约160 mg/h),10 min处理能诱导最大EPOC(约20 mg);无论驱赶还是空气暴露,呼吸频率的反应(上升28%～62%)远小于耗氧率(上升174%～254%)。实验表明两种逆境均能引起明显的胁迫反应,南方鲇对驱赶的反应远大于空气暴露。

Effects of Chase and Air Exposure on Oxygen Consumption and Respiration Frequency in Silurus meridionalis

The stress-related respiration response in juvenile southern catfish(22.11~79.52 g)during the resume process of chase(0,0.5,1,2.5 and 5 min)and air exposure(0,2.5,5,10 and 20 min)treatment were examined at 25℃ in this study.The results show that the oxygen consumption rate(VO)and respiration frequency(Vf)increased immediately after chase or air exposure treatment and slowly returned to pre-treatment status.The maximal peak VO was about 170 mg/h for 0.5 min chase group and the maximal excess post-chase oxygen consumption(EPOC)was about 35 mg for 2.5 min chase group.The maximal peak VO was about 160 mg/h for 5 min air exposure group and the maximal EPOC was about 20 mg for 10 min air exposure group.The Vf (rose 28%~62%)response to either chase or air exposure stress was much lower than those of VOrose 174%~254%).It suggested that the stress response of chase in southern catfish was much larger than that of air exposure.