1. Causes of worldwide freshwater mussel declines are poorly understood, and the potential role of the invasive Asian Clam, Corbicula fluminea, has received little attention.
2. We measured survival and growth of captively‐reared juveniles of four native mussel species during 84‐day in situ exposures at 17 sites in the Rockcastle River system, Kentucky, U.S.A., where mussel declines are attributed to coal mining. We measured water temperature, a comprehensive array of water chemistry variables, and Corbicula abundance at each site during mussel exposures.
3. Mussel survival was high (mean = 85.4%), did not differ among species, and was not related to any measured factor. In contrast, growth varied among sites by an order of magnitude, but growth responses were nearly identical for all four species. We found little evidence of water pollution from coal mining or other sources, and pollution did not explain variation in mussel growth. Growth was best explained by a model including only temperature (positive effect) and Corbicula abundance (negative effect) without interaction.
4. Our model predicts 46% lower mass gain over 84 days for every 10‐fold increase in Corbicula abundance regardless of temperature, but growth may be reduced to unsustainably low levels in cooler streams. Previous ideas about water pollution as a cause of low growth and mussel declines were not supported by our data. Instead, the predicted strong effects of Corbicula, combined with similar responses of four mussel species, suggest that Corbicula may be an important, but overlooked, factor in widespread mussel declines.

中文翻译：

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侵袭性双壳类虾的数量丰富，与野生淡水贻贝的生长负相关

1. 人们对全球淡水贻贝下降的原因知之甚少，而侵入性亚洲蛤Cor（Corbicula fluminea）的潜在作用却鲜为人知。
2. 我们在美国肯塔基州Rockcastle河水系统的17个地点测量了84种原生贻贝在人工饲养的4种贻贝中存活的存活和生长，贻贝的下降归因于煤炭开采。我们测量了贻贝暴露期间每个站点的水温，水化学变量的全面排列以及Corbicula的丰度。
3. 贻贝存活率很高（平均值= 85.4％），在物种之间没有差异，并且与任何可测量的因素都不相关。相反，位点之间的生长变化有一个数量级，但所有四个物种的生长响应几乎相同。我们发现很少有证据表明煤矿开采或其他来源造成水污染，而且污染不能解释贻贝生长的变化。用仅包含温度（正效应）和Corbicula丰度（负效应）而没有相互作用的模型可以最好地解释生长。
4. 我们的模型预测，不管温度如何，Corbicula丰度每增加10倍，则84天之内的质量增加会降低46％，但在凉爽的溪流中，生长可能会降低到不可持续的低水平。我们先前的关于水污染是造成低增长和贻贝下降的原因的想法并未得到我们的数据的支持。取而代之的是，Corbicula的预期强效作用以及四种贻贝物种的相似反应表明，Corbicula可能是造成贻贝普遍下降的重要但被忽视的因素。