Between global climate change and anthropogenic water needs, freshwater systems are becoming more intermittent, stressing organisms adapted to perennial waters. Drought‐induced intermittency concentrates aquatic organisms into drying pools. These pools represent refugia from desiccation but apply other stressors, such as extreme temperatures and increased competition for dwindling resources. In the Southern United States, fishes and freshwater mussels are often concentrated together in drying pools during seasonal, summer droughts. This can result in increased competition for food among invertivorous fish, but also increased food abundance for these fish because mussels increase macroinvertebrate abundance. Further, since mussels require fish as hosts for their ectoparasitic larval phase, glochidia, competition with their host during this biologically active time is detrimental to mussels. We conducted an experiment to examine the effects of freshwater mussels on trophic resources and fish survival in drying pools. We stocked mesocosms with juvenile largemouth bass that were infected or uninfected with glochidia and tracked abiotic conditions, trophic resources and fish survival for 10 days. We found that fish survived longer in the presence of adult mussels, regardless of their infection status. We suspect that prey items supplemented by adult freshwater mussels increased the survival of fish. Thus, the presence of adult mussels and the resources that increase in their presence potentially mitigate stress to fish in “ecological crunch times.” By conserving mussels, fish populations might withstand droughts more easily.

中文翻译：

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淡水贻贝可增加干燥池中大嘴鲈（Micropterus salmoides）的存活率

在全球气候变化和人为用水需求之间，淡水系统变得越来越断断续续，给适应多年生水体的生物造成了压力。干旱引起的间歇性将水生生物集中到干燥池中。这些池代表了干燥造成的避难所，但还施加了其他压力，例如极端温度和对日益减少的资源的竞争加剧。在美国南部，夏季和季节性干旱期间，鱼类和淡水贻贝通常集中在干燥池中。由于贻贝会增加大型无脊椎动物的种群数量，因此这可能导致非食用鱼类之间对食物的竞争加剧，但也导致这些鱼类的食物种群增加。此外，由于贻贝需要鱼类作为其寄生寄生幼虫期的寄主，因此，在此生物活跃时期与寄主的竞争不利于贻贝。我们进行了一项实验，以检验淡水贻贝对干燥池中营养资源和鱼类生存的影响。我们给幼年大嘴鲈的中观世界放养，它们感染了或未感染了甲虫，并追踪了10天的非生物状况，营养资源和鱼类生存情况。我们发现，无论贻贝的感染状况如何，在成年贻贝的存在下鱼的存活时间都更长。我们怀疑以成年淡水贻贝为辅的猎物会增加鱼类的生存率。因此，成年贻贝的存在及其增加的资源有可能减轻“生态紧缩时期”对鱼类的压力。通过保护贻贝，鱼类种群可能更容易经受干旱。