稀有鮈鲫在鱼类胚胎急性毒性试验中的适用性研究

为了验证我国本土鱼种稀有鮈鲫（Gobiocypris rarus）在鱼类胚胎急性毒性试验的适用性，评价其在鱼类替代试验中的应用潜力，选取3，4-二氯苯胺和五水硫酸铜，按照《OECD化学品测试准则No.236鱼类胚胎急性毒性试验》，分别开展6次稀有鮈鲫胚胎急性毒性试验，通过评价试验结果的重复性，验证稀有鮈鲫是否适用于鱼类胚胎急性毒性试验.结果表明:3，4-二氯苯胺和五水硫酸铜对稀有鮈鲫胚胎的96 h LC₅₀（96 h半数致死浓度）平均值（x）分别为12.8和1.76 mg/L，标准差（s）分别为1.70和0.197 mg/L；变异系数（CV）分别为13.3%和11.2%，均小于30%；两种化学品6次试验的96 h LC₅₀均在各自x±2s范围内.研究显示，稀有鮈鲫胚胎的形态特征、发育过程及孵化时间等生物学特征均与斑马鱼类似，3，4-二氯苯胺和五水硫酸铜这两种化学品的胚胎急性毒性试验结果具有良好的重复性，其敏感性也与成鱼类似.因此，稀有鮈鲫作为一种我国本土的标准试验鱼种，具有鱼类胚胎急性毒性试验的应用潜力. 

Applicability of Gobiocypris rarus in Fish Embryo Acute Toxicity Test

The study is aimed to validate whether Chinese rare minnow (Gobiocypris rarus) is applicable for fish embryo acute toxicity test, and also to evaluate the possibility of using its embryo as an alternative to test fish in acute toxicity tests, which lay a foundation for producing the related national standard of chemical testing. According to OECD Guidelines for the Testing of Chemicals No.236:Fish Embryo Acute Toxicity Test, six independent embryo tests were performed using newly fertilized eggs of G. rarus that were exposed to two reference substances, i.e. 3,4-dichloroaniline and copper sulfate pentahydrate, respectively. The repeatability of the test results was evaluated to validate whether G. rarus was applicable for fish embryo acute toxicity test. The mean estimates of the concentration causing 50% mortality (LC₅₀, x) of G. rarus embryos for a period of 96 h were 12.8 mg/L for 3,4-dichloroaniline and 1.76 mg/L for copper sulfate pentahydrate, with their corresponding standard deviations of 1.70 and 0.197 mg/L, respectively; and their coefficient of variation (CV) of LC₅₀ values were 13.3% and 11.2%, which was less than 30%. The 96 h LC₅₀ values of six runs for each chemical fallen into the range of (x±2s). The characteristics of G. rarus embryos regarding morphology, stages of development and hatch duration were quite similar to those of Danio rerio, and toxicity tests for two chemicals using G. rarus eggs presented a promising result, too. The sensitivity in G. rarus embryos'' response to the two chemicals was comparable to that of adult fish. Therefore, the endemic fish species, G. rarus could serve as a candidate organism for fish embryo acute toxicity test.