The effects of hypoxia on survival and reproduction of Calanus sinicus
低氧对中华哲水蚤存活和繁殖影响的实验研究

The mortality rates and reproduction of Calanus sinicus at different concentration of dissolved oxygen (DO) were investigated. The results showed that when DO declined to 2 mg/L, C. sinicus all died in 1 h. When DO declined to 3 mg/L, C.sinicus all died in 96 h. When DO was 4-6 mg/L, basically there was no death. But the spawning rate of C. sinicus could be significantly inhibited under this hypoxia condition. When DO was 4 mg/L, almost no spawn. When DO was 6 mg/L, the total spawning amount was only 15% of nornoxic group. When DO was 4-6 mg/L, the hatching rate was 60% of nomixic group. Therefore, hypoxia inhibits both survival and reproduction of C. sinicus. Long time hypoxia would reduce the population quantities of C. sinicus and even change the structure of ecosystem.