Freshwater mussels provide invaluable ecological services but are threatened by habitat alteration, poor water quality, invasive species, climate change, and contaminants, including contaminants of emerging concern (CECs). Contaminants of emerging concerns are well documented in aquatic environments, including the Great Lakes Basin, but limited information is available on how environmentally relevant mixtures affect freshwater mussel biology throughout their varied life stages. Our main goal was to assess mussels' reproductive output in response to exposure to agricultural and urban CEC mixtures during glochidial development through juvenile transformation and excystment focusing on how exposure duration and treatment affect: (1) the number of glochidia prematurely released by brooding females, (2) glochidial transformation through host‐fish excystment, and (3) the number of fully metamorphosed juveniles able to continue the lifecycle. Mussels and host fish were exposed to either a control water (CW), control ethanol (CE), agriculture CEC mixture (AM), or urban CEC mixture (UM) for 40 and 100 days. We found no effect from treatment or exposure duration on the number of glochidia prematurely released. Fewer partially and fully metamorphosed AM juveniles were observed during the 100‐day exposure, compared with the 40‐day. During the 40‐day exposure, CW produced more fully metamorphosed individuals compared with CE and UM, but during the 100‐day exposure AM produced more fully metamorphosed individuals compared with the CW. There was reduction in fully metamorphosed juveniles compared with partially metamorphosed for CE and UM during the 40‐day exposure, as well as in the CW during the 100‐day exposure. These results will be important for understanding how mussel populations are affected by CEC exposure. The experiments also yielded many insights for laboratory toxicology exposure studies. Environ Toxicol Chem 2024;00:1–14. © 2024 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC. This article has been contributed to by U.S. Government employees and their work is in the public domain in the USA.

中文翻译：

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农业和城市污染物混合物暴露导致淡水贻贝幼体产量减少

淡水贻贝提供了宝贵的生态服务，但受到栖息地改变、水质差、入侵物种、气候变化和污染物（包括新兴关注污染物（CEC））的威胁。在包括五大湖盆地在内的水生环境中，新出现的污染物已得到充分记录，但有关环境相关混合物如何影响淡水贻贝在其不同生命阶段的生物学的信息有限。我们的主要目标是评估贻贝在钩毛发育过程中通过幼体转化和排泄对农业和城市 CEC 混合物暴露的反应，重点关注接触持续时间和治疗如何影响：(1) 育雏雌性过早释放的钩毛数量， （2）通过寄主鱼的排泄进行钩毛转化，以及（3）能够继续生命周期的完全变态幼体的数量。将贻贝和寄主鱼暴露于对照水 (CW)、对照乙醇 (CE)、农业 CEC 混合物 (AM) 或城市 CEC 混合物 (UM) 中 40 和 100 天。我们发现治疗或暴露时间对过早释放的球毛虫数量没有影响。与 40 天的暴露相比，在 100 天的暴露期间观察到的部分和完全变态的 AM 幼虫较少。在 40 天的暴露期间，与 CE 和 UM 相比，CW 产生了更完全变态的个体，但在 100 天的暴露期间，AM 比 CW 产生了更完全变态的个体。在 40 天暴露期间，CE 和 UM 以及 CW 在 100 天暴露期间，与部分变态相比，完全变态的幼鱼有所减少。这些结果对于了解 CEC 暴露如何影响贻贝种群非常重要。这些实验还为实验室毒理学暴露研究提供了许多见解。环境毒理化学2024；00：1–14。 © 2024 作者。环境毒理学和化学由 Wiley periodicals LLC 代表 SETAC 出版。本文由美国政府雇员撰写，他们的作品在美国属于公共领域。