University of Applied Sciences Zittau/Görlitz, Theodor-Körner-Allee 16, D-02763 Zittau, Germany.
Sci Total Environ. 2012 Oct 1;435-436:90-5. doi: 10.1016/j.scitotenv.2012.07.005. Epub 2012 Jul 28.
The development of a chronic mollusc toxicity test is a current work item on the agenda of the OECD. The freshwater pond snail Lymnaea stagnalis is one of the candidate snail species for such a test. This paper presents a 21-day chronic toxicity test with L. stagnalis, focussing on embryonic development. Eggs were collected from freshly laid egg masses and exposed individually until hatching. The endpoints were hatching success and mean hatching time. Tributyltin (TBT), added as TBT-chloride, was chosen as model substance. The selected exposure concentrations ranged from 0.03 to 10 μg TBT/L (all as nominal values) and induced the full range of responses. The embryos were sensitive to TBT (the NOEC for mean hatching time was 0.03 μg TBT/L and the NOEC for hatching success was 0.1 μg TBT/L). In addition, data on maximum limit concentrations of seven common solvents, recommended in OECD aquatic toxicity testing guidelines, are presented. Among the results, further findings as average embryonic growth and mean hatching time of control groups are provided. In conclusion, the test presented here could easily be standardised and is considered useful as a potential trigger to judge if further studies, e.g. a (partial) life-cycle study with molluscs, should be conducted.
OECD 目前正在制定慢性贝类毒性测试方法，淡水圆田螺（Lymnaea stagnalis）是候选贝类物种之一。本文报告了一项为期 21 天的慢性毒性测试，以胚胎发育为重点，研究对象为圆田螺。从新产下的卵团中收集卵子，单独暴露至孵化。终点为孵化成功率和平均孵化时间。三丁基锡（TBT）作为模型物质，以 TBT 氯化物的形式添加。选择的暴露浓度范围为 0.03 至 10μg TBT/L（均为名义值），并诱导了全范围的反应。胚胎对 TBT 敏感（平均孵化时间的无可见效应浓度为 0.03μg TBT/L，孵化成功率的无可见效应浓度为 0.1μg TBT/L）。此外，还报告了 OECD 水生毒性测试指南中推荐的七种常见溶剂的最高限量浓度数据。在这些结果中，还提供了对照组的平均胚胎生长和平均孵化时间等进一步发现。总之，本文提出的测试方法易于标准化，可作为潜在的触发因素，用于判断是否需要进行进一步的研究，例如使用贝类进行（部分）生命周期研究。
