中文摘要：

高坝工程在泄流时,高速水流强烈的掺气作用导致下游水体中总溶解气体（Total Dissolved Gas,TDG）过饱和,从而使水体中鱼类患上气泡病,威胁到其生存。本文以二龄齐口裂腹鱼幼鱼为研究对象,对其开展了急性致死实验、间歇胁迫实验、水平回避实验和垂直回避实验,结果表明齐口裂腹鱼持续暴露在TDG饱和度为120%、125%和130%的水体中的半致死时间分别为10.7 h、9.5 h和6.5 h。通过短时间的TDG过饱和暴露结合长时间的清水恢复能显著地延长齐口裂腹鱼在TDG过饱和水体中的生存时间。齐口裂腹鱼对饱和度为135%和145%水体具有较强的探知和回避能力,而当水体TDG饱和度为125%及以下时,其探知和回避能力较弱。齐口裂腹鱼在垂直方向具有利用补偿水深来回避水体中TDG过饱和的能力。

英文摘要：

When high dams discharge flows, the intense aeration produced by high velocity flow leads to the generation of total dissolved gas （TDG） supersaturation downstream of the dams, which makes fish sus- ceptible to gas bubble disease and threatens their survival. Two-year-old Schizothorax pernanti was used for experiments on acute lethality, intermittent exposure, horizontal avoidance and vertical avoidance of TDG supersaturation. The median lethal times （LT50） of the fish in supersaturated water were 10.7 h, 9.5 h and 6.5 h, respectively, when the TDG supersaturated levels were 120 %, 125 % and 130 %. The survival time of Schizothorax pernanti exposed to the TDG supersaturated water extended through exposing to the TDG supersaturated water a short period of time and recovering in the fresh water for a long time. Schizothorux pernanti had strong ability of detection and avoidance to the TDG supersaturated water when the TDG supersaturat- ed levels were 135 % and 145 %, and when the supersaturated level was 125 % or below, this kind of ability of Schizothorax pernanti was weaker. Schizothorax pernanti has the ability to use compensation depth to avoid TDG supersaturated water in the vertical direction.