Hopkins William Alexander, DuRant Sarah Elizabeth, Staub Brandon Patrick, Rowe Christopher Lee, Jackson Brian Phillip
Savannah River Ecology Laboratory, University of Georgia, USA.
Environ Health Perspect. 2006 May;114(5):661-6. doi: 10.1289/ehp.8457.
Although many amphibian populations around the world are declining at alarming rates, the cause of most declines remains unknown. Environmental contamination is one of several factors implicated in declines and may have particularly important effects on sensitive developmental stages. Despite the severe effects of maternal transfer of contaminants on early development in other vertebrate lineages, no studies have examined the effects of maternal transfer of contaminants on reproduction or development in amphibians. We examined maternal transfer of contaminants in eastern narrow-mouth toads (Gastrophryne carolinensis) collected from a reference site and near a coal-burning power plant. Adult toads inhabiting the industrial area transferred significant quantities of selenium and strontium to their eggs, but Se concentrations were most notable (up to 100 microg/g dry mass). Compared with the reference site, hatching success was reduced by 11% in clutches from the contaminated site. In surviving larvae, the frequency of developmental abnormalities and abnormal swimming was 55-58% higher in the contaminated site relative to the reference site. Craniofacial abnormalities were nearly an order of magnitude more prevalent in hatchlings from the contaminated site. When all developmental criteria were considered collectively, offspring from the contaminated site experienced 19% lower viability. Although there was no statistical relationship between the concentration of Se or Sr transferred to eggs and any measure of offspring viability, our study demonstrates that maternal transfer may be an important route of contaminant exposure in amphibians that has been overlooked.
尽管世界各地许多两栖动物种群正以惊人的速度减少，但大多数减少的原因仍不明朗。环境污染是与种群减少相关的几个因素之一，并且可能对敏感的发育阶段产生尤为重要的影响。尽管污染物的母体转移对其他脊椎动物谱系的早期发育有严重影响，但尚无研究考察污染物的母体转移对两栖动物繁殖或发育的影响。我们研究了从一个对照点和一家燃煤发电厂附近采集的东部窄口蟾（Gastrophryne carolinensis）体内污染物的母体转移情况。栖息在工业区的成年蟾蜍将大量的硒和锶转移到它们的卵中，但硒的浓度最为显著（高达100微克/克干重）。与对照点相比，受污染点的卵块孵化成功率降低了11%。在存活的幼体中，受污染点发育异常和游泳异常的频率比对照点高55 - 58%。受污染点孵化出的幼体中颅面异常的发生率几乎高出一个数量级。综合考虑所有发育标准，受污染点的后代存活率降低了19%。尽管转移到卵中的硒或锶的浓度与后代生存能力的任何指标之间没有统计学关系，但我们的研究表明，母体转移可能是两栖动物接触污染物的一条被忽视的重要途径。
