University of Georgia, Interdisciplinary Toxicology Program, Warnell School of Forestry and Natural Resources, Athens, Georgia, USA.
Environ Toxicol Chem. 2012 Jul;31(7):1611-20. doi: 10.1002/etc.1866. Epub 2012 May 22.
Freshwater mussels are among the most sensitive aquatic organisms to many contaminants and have complex life-cycles that include several distinct life stages with unique contaminant exposure pathways. Standard acute (24-96 h) and chronic (28 d) toxicity tests with free larva (glochidia) and juvenile mussels are effective at generating data on contaminant effects at two discrete life stages but do not incorporate effects on brooded glochidia. We developed a novel partial life-cycle assay that incorporates exposures to brooding adult female mussels and used this method in combination with acute toxicity tests to assess adverse effects of perfluoroctanesulfonic acid (PFOS) and perfluoroctanoic acid (PFOA) on freshwater mussels. Fatmucket (Lampsilis siliquoidea) were exposed to PFOS at two life stages: brooding glochidia (in marsupia) for 36 d and free glochidia in water for 24 h. In standard acute tests with glochidia (24-48 h exposures) and juveniles (48-96 h exposures) of fatmucket and black sandshell (Ligumia recta), glochidia were 8 to 25 times more sensitive than juveniles. Perfluoroctanesulfonic acid significantly reduced the duration of glochidia viability and reduced probability of metamorphosis at concentrations 3,000 times lower than the most sensitive acute endpoint (24-h EC50). The partial life-cycle test is adaptable to a variety of endpoints and research objectives and is useful for identifying adverse effects at contaminant concentrations below those required for an acute lethal response.
淡水贻贝对许多污染物非常敏感，其生命周期复杂，包括几个不同的生命阶段，每个阶段都有独特的污染物暴露途径。游离幼虫（钩介幼虫）和幼贝的标准急性（24-96 小时）和慢性（28 天）毒性试验可有效生成两种不同生命阶段的污染物影响数据，但不包括对孵育钩介幼虫的影响。我们开发了一种新的部分生命周期测定法，将其与亲贝的孵育暴露相结合，并将该方法与急性毒性试验结合使用，以评估全氟辛烷磺酸（PFOS）和全氟辛酸（PFOA）对淡水贻贝的不良影响。Fatmucket（Lampsilis siliquoidea）在两个生命阶段暴露于 PFOS：孵育钩介幼虫（在育儿袋中）36 天和自由钩介幼虫在水中 24 小时。在 Fatmucket 和黑砂壳（Ligumia recta）幼虫（24-48 小时暴露）和幼贝（48-96 小时暴露）的标准急性试验中，钩介幼虫比幼贝敏感 8 到 25 倍。全氟辛烷磺酸可显著降低钩介幼虫的存活时间，并在比最敏感的急性终点（24 小时 EC50）浓度低 3000 倍的浓度下降低变态的可能性。部分生命周期试验可适应各种终点和研究目标，对于在低于急性致死反应所需浓度的污染物浓度下识别不良影响非常有用。
