1. Increases in total suspended solids (TSS) reduce feeding and reproductive success of unionid mussels, but mussels in turbid rivers are less affected than those in clear rivers, probably due to differences in gill and palp morphology. This study was designed to determine whether the differences observed between adult mussels in populations from turbid versus clear rivers are due to phenotypic plasticity.
2. Parasitic larvae (glochidia) of Lampsilis siliquoidea (Fatmucket) obtained from a low turbidity river (TSS < 5 mg/L) were transformed on Ambloplites rupestris (Rock Bass) in the laboratory to obtain juvenile mussels for rearing under clear and turbid conditions in the laboratory (i.e. nominally 0 versus 50 mg/L suspended river sediment). Juveniles obtained were reared under these contrasting conditions until age 3–4 weeks, when they were examined in a feeding experiment under a range of TSS concentrations (0, 5, 10, 15, 20, 25 mg/L).
3. The clearance rate (volume cleared of particles per unit time) of algae by juveniles from both rearing conditions was similar for the no‐TSS control and declined with increased TSS. The rate of decline was, however, lower in the group reared under turbid conditions, which is consistent with reports for adult mussels.
4. Our results indicate that differences in the clearance rate response to high TSS observed in mussels in clear and turbid rivers are probably driven in part by phenotypic plasticity. This finding provides a mechanism to explain how freshwater mussels thrive under turbid conditions as well as informs conservation efforts involving reintroduction of mussels in this highly imperilled taxon.

中文翻译：

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表皮可塑性对浑浊度响应的表型可塑性的证据

1. 总悬浮固体（TSS）的增加会降低混生贻贝的摄食和繁殖成功率，但混浊河流中的贻贝比清澈河流中的贻贝受到的影响较小，这可能是由于g和ill的形态不同所致。这项研究旨在确定在浑浊的河流和清澈的河流中，成年贻贝之间的差异是否归因于表型可塑性。
2. 从低浊度河（TSS <5 mg / L）中获得的兰氏拟南芥（Fatmucket）的寄生幼虫（glochidia）在实验室的Ambloplites rupestris（Rock Bass）上进行转化，以获得幼贻贝，以便在清澈，浑浊的条件下饲养实验室（即名义上为0对50 mg / L的悬浮河沉积物）。在不同的TSS浓度（0、5、10、15、20、25 mg / L）下进行喂养实验时，将这些幼鱼在这些对比条件下饲养到3-4周龄。
3. 两种饲养条件下，幼鱼对藻类的清除率（每单位时间清除的颗粒体积）在无TSS控制下相似，并且随着TSS的增加而降低。但是，在混浊条件下饲养的组中，下降率较低，这与成年贻贝的报告一致。
4. 我们的结果表明，在清澈浑浊的河流中，贻贝观察到的对高TSS的清除率响应的差异可能部分由表型可塑性驱动。这一发现提供了一种机制，可以解释淡水贻贝在浑浊的条件下如何繁衍生息，并为涉及在这种高度受灾的分类群中重新引入贻贝的保护工作提供依据。