A moderate increase in temperature is likely to enhance the impact of parasites on aquatic ecosystems. Thus, under higher temperatures, poikilothermic animals (e.g. fish) increase their activity, which can result in a more frequent encounter with parasites and higher infection risk. However, temperature increase may also trigger counteracting processes in ambient communities decreasing the risk of parasitic infections. For instance, the removal of free‐living stages of parasites by filter‐feeding organisms can increase with temperature and potentially mitigate the disease risk in ecosystems under temperature shift. We examined whether an enhanced parasite transmission under higher temperatures can be compensated by the increased removal of parasitic larvae by filter‐feeders. In addition, our study aimed to reveal the behavioral mechanism underlying the more successful transmission of the parasite at higher temperatures. We studied experimentally how temperature, behavior of fish hosts (rainbow trout), and presence of filter‐feeding mussels in the environment influence the infection success of trematode larvae (Diplostomum pseudospathaceum cercariae). We found that heating increased while the presence of filter‐feeding mussels in the environment decreased infection intensities in fish. However, the effect of mussel's presence was constant within the tested range of water temperatures (15–23°C), which suggests that it cannot compensate for the observed increased transmission of parasites with temperature increase. Fish activity before the exposure to parasites was positively related to the host's vulnerability to infection. However, fish activity only weakly correlated with temperature, therefore, it is unlikely to be the only factor influencing the infection success under warmer conditions. In general, we showed that the elimination of trematode larvae by filter‐feeders is unlikely to deter the potential effects of temperature increase on host–parasite interactions in temperate freshwater ecosystems.

中文翻译：

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温度变化下水生生态系统中的寄生虫传播：宿主活动和滤食者消除寄生虫幼虫的影响

温度的适度升高可能会增强寄生虫对水生生态系统的影响。因此，在较高的温度下，体温过高的动物（例如鱼）会增加其活动能力，这可能导致更频繁地遇到寄生虫并增加感染风险。但是，温度升高也可能触发周围社区的抵消过程，从而降低了寄生虫感染的风险。例如，以滤食为生的生物对寄生虫自由活动阶段的去除会随着温度的升高而增加，并有可能减轻温度变化下生态系统中的疾病风险。我们检查了在高温下寄生虫传播的增强是否可以通过滤嘴喂食器对寄生虫幼虫的去除增加得到补偿。此外，我们的研究旨在揭示在高温下更成功地传播寄生虫的行为机制。我们通过实验研究了温度，鱼寄主（虹鳟鱼）的行为以及环境中滤食贻贝的存在如何影响吸虫吸虫的成功（伪狂犬病尾c）。我们发现，当环境中存在滤食性贻贝时，加热会增加，同时会降低鱼类的感染强度。然而，贻贝的存在在测试的水温范围内（15–23°C）是恒定的，这表明它无法补偿所观察到的寄生虫随温度升高而增加的传播。暴露于寄生虫之前的鱼类活动与寄主易感染性呈正相关。但是，鱼的活动与温度之间的关系很小，因此，不可能是在温暖的条件下影响感染成功的唯一因素。一般来说，