PDF(Pubmed)
Abstract：
Freshwater mussels (Mollusca: Unionidae) play a crucial role in freshwater river environments where they live in multi-species aggregations and often serve as long-lived benthic ecosystem engineers. Many of these species are imperiled and it is imperative that we understand their basic needs to aid in the reestablishment and maintenance of mussel beds in rivers. In an effort to expand our knowledge of the diet of these organisms, five species of mussel were introduced into enclosed systems in two experiments. In the first, mussels were incubated in water from the Clinch River (Virginia, USA) and in the second, water from a manmade pond at the Commonwealth of Virginia\'s Aquatic Wildlife Conservation Center in Marion, VA. Quantitative PCR and eDNA metabarcoding were used to determine which planktonic microbes were present before and after the introduction of mussels into each experimental system. It was found that all five species preferentially consumed microeukaryotes over bacteria. Most microeukaryotic taxa, including Stramenopiles and Chlorophytes were quickly consumed by all five mussel species. We also found that they consumed fungi but not as quickly as the microalgae, and that one species of mussel, Ortmanniana pectorosa, consumed bacteria but only after preferred food sources were depleted. Our results provide evidence that siphon feeding Unionid mussels can select preferred microbes from mixed plankton, and mussel species exhibit dietary niche differentiation.
摘要：
淡水贻贝（Mollusca：Unionidae）在淡水河流环境中起着至关重要的作用，它们生活在多物种聚集中，并且经常充当长寿的底栖生态系统工程师。其中许多物种受到威胁，我们必须了解它们的基本需求，以帮助重建和维护河流中的贻贝床。为了扩大我们对这些生物饮食的认识，在两个实验中，将五种贻贝引入封闭系统。在第一,贻贝在克林奇河(弗吉尼亚州，美国)，在第二个，马里恩弗吉尼亚联邦水生野生动物保护中心的人造池塘里的水，VA.定量PCR和eDNA元编码用于确定在将贻贝引入每个实验系统之前和之后存在哪些浮游微生物。发现所有五个物种都优先于细菌消耗微真核生物。大多数微真核生物类群，包括Stramenopiles和绿藻被所有五种贻贝迅速消耗。我们还发现它们消耗真菌，但不如微藻快，还有一种贻贝，Ortmannianapectorosa,消耗细菌，但仅在首选食物来源耗尽后。我们的结果提供了证据，虹吸喂养Unionid贻贝可以从混合浮游生物中选择优选的微生物，贻贝物种表现出饮食生态位分化。
