Abstract：
This study examined the impact of sertraline, an antidepressant common in treated wastewater, on the host-parasite dynamics between parasitic freshwater mussel (Unio tumidus, Unionidae) larvae (glochidia) and their host fish (Squalius cephalus, Cyprinidae). Employing a full-factorial design, both fish and glochidia were subjected to sertraline at the combinations of 0 µg L-1 (control), 0.2 µg L-1 (environmentally relevant concentration), and 4 µg L-1 (elevated concentration, short-term exposure of the parasite). The results showed that long-term host exposure (involving intensive sertraline accumulation in the fish brain) marginally increased subsequent glochidia attachment success by 2 %, while parasite exposure at the same environmentally relevant concentrations had no detectable effect. There was also no effect of exposure of glochidia to 0.2 µg L-1 of sertraline on their viability and encapsulation success during the initial parasitic stage. However, a significant alteration in attachment behavior, marked by a 3.3 % increase in attachment success and changes in the glochidia spatial distribution on the host body, was noted after 24 h of glochidia exposure to 4 µg L-1 of sertraline. Importantly, this study provides the first evidence of sertraline transfer from exposed glochidia to nonexposed host fish, as indicated by elevated levels of sertraline (12.8 ng g-1) in the brain tissue of nonexposed hosts. These findings highlight the subtle yet significant effects of pharmaceutical pollutants on freshwater ecosystems but also underscore the importance of understanding the unexpected dynamics of such contamination to predict and address future ecological changes.
摘要：
这项研究检查了舍曲林的影响，在处理过的废水中常见的抗抑郁药，关于寄生淡水贻贝之间的寄主-寄生虫动力学(Uniotumidus，Unionidae）幼虫（glochidia）及其寄主鱼（Squaluuscephalus，鲤科）。采用全因子设计，鱼和glochidia均以0µgL-1的组合接受舍曲林（对照），0.2µgL-1（与环境相关的浓度），和4µgL-1(浓度升高，寄生虫的短期暴露)。结果表明，长期的宿主暴露（涉及鱼脑中强烈的舍曲林积累）会使随后的glochidia附着成功率略微增加2％，而相同环境相关浓度的寄生虫暴露没有可检测的影响。在最初的寄生阶段，glochidia暴露于0.2µgL-1的舍曲林对其生存力和包封成功率也没有影响。然而,依恋行为的显著改变，以附件成功率增加3.3%和宿主身体上球茎空间分布的变化为标志，在甘草暴露于4µgL-1舍曲林24小时后发现。重要的是,这项研究提供了舍曲林从暴露的球藻转移到未暴露的宿主鱼的第一个证据，如未暴露宿主脑组织中舍曲林水平升高（12.8ngg-1）所示。这些发现突出了药物污染物对淡水生态系统的微妙而重大的影响，但也强调了理解此类污染的意外动态以预测和应对未来生态变化的重要性。
