Zn^(2+)对罗非鱼呼吸运动的影响和解毒的初探

EFFECT OF Zn^(2+)ON THE RESPIRATORY ACTIVITY OF TILAPIA SP.WITH REFERENCE TO DETOXICATION METHODS

将罗非鱼分别置于含有1、4、8、12ppm ZnSO_4的软、硬质水中,研究15d 中不同亚致死浓度 Zn^(2+)对鱼呼吸和咳嗽反应频率的影响;观测比较加入 EDTA 络合剂的变化,探索解除鱼Zn^(2+)中毒的方法。结果如下:1)呼吸频率的变化和咳嗽反应明显受 Zn^(2+)浓度影响,浓度越大,呼吸频率曲线越偏离对照曲线,咳嗽反应的频率亦越高,它们可作为鱼中毒和解毒的生理学监测指标。2)硬水组鱼受 Zn^(2+)毒害明显小于软水组。3)EDTA 可解除或减轻 Zn^(2+)对鱼的毒害,但其在软、硬水中的解毒效应无明显差异。

Fish were exposed to either soft water or hard water containing 1,4,8 and 12 ppm ZnSO_4.The sublethal effects of Zn^(2+) on respiration and cough frequencies were studied over a period of 15 days.Changes in the respiratory activities were recorded after the addition of EDTA.Methods for detoxication were explored.The results are as follows.(1)Respiratory frequency and cough response were apparently affected by Zn^(2+) concentration.The higher the Zn^(2+) concentration,the further the respiratory frequency curve deviated from the control,and the higher the cough frequency.These responses can be used as indices for the physiological monitoring of toxication and detoxication in fish.(2)Zn^(2+) toxicity was apparently lower in hard water than in soft water.(3)EDTA can eliminate or lessen the toxic effect of Zn^(2+);its de- toxication effects were similar in soft and hard water.