红剑鱼、孔雀鱼、食蚊鱼亚慢性毒性试验

Subchronic Toxicity Test for Xiphophorus helleri,Lebistes reticulatus and Gambusia affinis

目的研究一种快速评价有毒化学品对红剑鱼、孔雀鱼、食蚊鱼慢性毒性的试验方法。方法选择<3d龄的红剑鱼、孔雀鱼、食蚊鱼幼鱼开始暴露,试验药物为国际标准参比毒物Cr6+、Cu2+、Zn2+和Cd2+,试验温度为25±1℃,每天更换试验液1次,试验持续5d。依据试验鱼的每尾干重和现存量作为观察指标,测定了铬、锌、铜、镉对红剑鱼、孔雀鱼和食蚊鱼的无可观察效应浓度(NOEC)和最低可观察效应浓度(LOEC)。结果铬、锌、铜、镉对红剑鱼和食蚊鱼的NOEC分别是2500、100、10、10μg/L,LOEC分别是5000、200、20、20μg/L。铬、锌、铜、镉对孔雀鱼的NOEC分别是2500、100、10、20μg/L,LOEC分别是5000、200、20、40μg/L;这与7天亚慢性试验结果相接近。结论红剑鱼、孔雀鱼、食蚊鱼,亚慢性毒性试验可从7d缩短为5d。

A rapid approach was described to estimate the chronic toxicity of toxicants to the Xiphophorus helleri, Lebistes reticulatus and Gambusis affinis. Tests were initiated using 〈 3d old X. helleri, L. reticulatus and G. affinis lavage and were run for 5d under static-renewal condition at 25 ± 1℃ . Based on growth and standing crop,to X. helleri and G. affinis,the no observed effect concentration（NOEC） of Cr^6＋ , Zn^2＋ , Cu^2＋ and Cd^2＋ were 2500, 100,10, 10 μg/L and lowest observed effect concentration （LOEC） were 5000,200,20,20 μg/L, respectively. The NOEC of Cr^6＋ , Zn^2＋, Cu^2＋ and Cd^2＋ were 2500, 100, 10, 20 μg/L, the LOEC were 5000, 200, 20, 40 μg/L for L. reticulates, respectively. Compared with 7 d subchronic test using the same reference toxicants, the results agreed well, which indicate that short-term methods for estimating the chronic toxicity to freshwater fish may be shorten from 7 d to 5 d.