气体过饱和对不同早期发育阶段鲫的影响研究

Effects of gas supersaturation on Carassius auratus at different early development stages

汛期长江流域大坝的泄洪可能导致下游水体气体过饱和,干扰或损害下游水生生物的正常生命活动。为了研究水体气体过饱和对长江流域重要经济鱼类鲫的影响,将处于不同早期发育阶段(受精卵、仔鱼、稚鱼和幼鱼)的鲫(Carassius auratus)暴露于气体饱和度分别为110%,120%,130%和140%的水体中,其中受精卵暴露至出膜,仔鱼、稚鱼和幼鱼均暴露96 h。结果表明:受精卵的孵化率变化范围为61.43%~72.86%,实验组与对照组之间孵化率无显著差异;仔鱼、稚鱼和幼鱼实验组均出现不同程度的气泡病症状;实验组死亡率随饱和度和暴露时间的增加而升高;相同饱和度下幼鱼死亡率最高,稚鱼次之,仔鱼最低;随着饱和度的升高,幼鱼的半致死时间显著减少。

During the flood season,flood discharge of dams in the Changjiang River could cause gas supersaturation of the downstream water bodies,which might disturb or damage the normal life activities of aquatic organisms living in the downstream area.This paper aimed to study the impact of gas supersaturation on Carassius auratus,one of the important economic species in the Changjiang River,and provide theoretical basis for the protecting of aquatic organism resources in the Changjiang River.Carassius auratus at different early development stages,namely fertilized eggs,larvae,small juveniles and large juveniles,were exposed to water with 110%,120%,130%,and 140% gas saturation.The fertilized eggs were exposed until hatching;larvae,small juveniles and large juveniles were exposed in the gas supersaturation water for 96 h.Results showed that the hatching rate was ranged from 61.43% to 72.86%,and there were no significant difference between the experimental groups and the control group.All the experimental fish showed different degrees of symptoms of gas bubble disease;the mortality of experimental fish increased with the increase of exposure time and the degree of gas supersaturation;the mortality of large juvenile fish was the highest at each saturation,followed by small juvenile fish,and larvae were the lowest.With the increase of gas supersaturation,the semi-lethal time of juvenile fish decreased significantly.