稀有鮈鲫作为鱼类幼体生长试验受试鱼种的适用性研究

Applicability of Chinese rare minnows for the juvenile fish growth test

目的通过验证稀有鮈鲫作是否适用于幼体生长试验,为相关化学品测试国家标准的制定提供依据。方法以重铬酸钾和3,4-二氯苯胺为参比物质,按照《OECD化学品测试准则No.215鱼类幼体生长试验》,分别开展三次实验室内稀有鮈鲫幼体生长试验以评价试验结果的重复性,进行实验室间比对试验以评价试验结果的再现性。结果实验室内重复试验中,重铬酸钾和3,4-二氯苯胺对稀有鮈鲫生长抑制效应(EC_(20))平均值分别为30.9 mg/L和163μg/L,变异系数均小于15%;实验室间比对试验中,虽然变异系数增大,但是各实验室的28 d EC_(20)均在【math14】±2s范围之内。结论稀有鮈鲫幼体生长试验结果具有良好的重复性和再现性,且稀有鮈鲫对3,4-二氯苯胺的敏感性与虹鳟(Oncorhynchus mykiss)相当,因此稀有鮈鲫可作为鱼类幼体生长试验的本土受试鱼种。

Objective This study is aimed to validate whether Chinese rare minnows(Gobiocypris rarus)are applicable for the juvenile fish growth test as a test fish,and to lay a foundation for the national standards of chemical testing.Methods According to“OECD Guidelines for the Testing of Chemicals No.215:Fish,Juvenile Growth Test”,juvenile fish growth tests were performed using G.rarus that were exposed to two reference substances(potassium bichromate and 3,4-dichloroaniline).To evaluate the repeatability of the testing method using G.rarus,the toxic effects of each substance were determined three times in our testing facility,while other domestic laboratories were involved in the ring test program to evaluate the reproducibility of the method.Results Regarding the repeated tests,the mean estimates of the concentration that would cause a 20%reduction in growth relative to controls(EC 20)were 30.9 mg/L and 163μg/L for potassium bichromate and 3,4-dichloroaniline,respectively.For both,the coefficients of variance were<15%.Although higher coefficients of variance for the datasets of the two substances were reported in the ring test,EC 20 values from all laboratories varied within a range of(±2 s).Conclusions Evaluating the repeatability and reproducibility of this test using G.rarus has presented promising result,and the level of sensitivity of this native fish species is comparable to that of Oncorhynchus mykiss in relation to the exposure of 3,4-dichloroaniline.Therefore,G.rarus can serve as standard test fish for toxicity studies.