Zebra and Quagga Mussel Dry Weight Information; Lake Erie 2014

Impacts of dreissenid mussels (Dreissena spp.) on Great Lakes ecosystems are well documented, and a better understanding of mechanisms that cause variation in mussel abundance is needed. An outstanding question is how much mussel biomass is consumed by fish predation. A significant difficulty for investigating mussel consumption by fish is that mussels in stomachs are often a mix of crushed shell and flesh. Here, we provide information on the relationship between shell-and-flesh dry weight measurements and flesh-only dry weight of two species of dreissenid mussel, quagga (Dreissena rostiformis bugensis) and zebra (Dreissena polymorpha), to be used in formulating conservative estimates of flesh-only dry weight in fish diets. Dry weight analyses were conducted to simulate stomach contents ranging from small (individual mussels) to large (aggregate of mussels). All measurements were taken at the USGS Lake Erie Biological Station in Sandusky, Ohio using quagga and zebra mussels collected from Lake Erie in May, 2014.斑贻贝（Dreissena spp.）对五大湖生态系统的影响已有充分文献记载，当前仍需进一步阐明导致贻贝种群丰度产生差异的内在机制。目前一个悬而未决的核心问题是：鱼类捕食所消耗的贻贝生物量究竟有多少。研究鱼类对贻贝的摄食情况存在一项显著难点：鱼类胃容物中的贻贝通常为破碎贝壳与软组织的混合物。本研究针对两种斑贻贝——斑驴贻贝（Dreissena rostiformis bugensis）与斑马贻贝（Dreissena polymorpha），测定了其带壳软组织干重与纯软组织干重之间的关联，该数据可用于构建鱼类日粮中纯软组织干重的保守估算方法。本次干重分析通过模拟不同规格的胃容物开展，样本覆盖单只小型贻贝至大型聚集贻贝群的全范围。所有测量工作均于2014年5月在俄亥俄州桑达斯基市的美国地质调查局（USGS）伊利湖生物站完成，实验所用贻贝采自2014年5月的伊利湖。