Selective Predation by Muskrats on Freshwater Mussels in 2 Minnesota Rivers
Selective Predation by Muskrats on Freshwater Mussels in 2 Minnesota Rivers
复制标题
明尼苏达州两条河流中麝香鼠对淡水贻贝的选择性捕食
DOI：
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发表时间：
1998
影响因子：
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通讯作者：
D. Hornbach
中科院分区：
文献类型：
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作者：
M. Tyrrell;D. Hornbach
麝鼠（Ondatra zibethicus）的捕食已被假设影响淡水贻贝组合的结构。我们比较了在圣克罗伊河的3个地点和密西西比河的1个地点从贝丘和原位收集的贻贝的种类组成和大小。从河流中采集的贻贝物种多样性高于从水体中采集的贻贝。Logistic回归分析结果显示，河川和河川的贻贝种类组成和贻贝大小存在显著差异，表明河川和河川的贻贝既具有大小选择性，又具有种类特异性。麝鼠从小物种中获取大个体，从大物种中获取小个体，这可能导致物种和大小之间的重要相互作用。小种truncata在优势种的2个位点表现为选择，其他2个位点表现为回避。这一结果表明，麝鼠可能是在使用一种策略，通过选择特定大小的猎物来最大化能量，但在无法获得较大猎物的地方，它们会接受通常被认为是边缘猎物的较小物种。
Muskrat (Ondatra zibethicus) predation has been hypothesized to influence the structure of freshwater mussel assemblages. We compared the species composition and sizes of mussels collected from middens and in situ at 3 locations in the St. Croix River and 1 location in the Mississippi River. Species diversity was greater for mussels collected from the rivers compared to those collected from middens. Logistic regression revealed mussel species composition and mussel size differed significantly between the rivers and middens, which suggested that muskrats were both size-selective and species-specific feeders. A significant interaction between species and size may result from muskrats taking large individuals from small species and small individuals from large species. There was selection for the small species, Truncilla truncata, at the 2 sites where it was the dominant species, and avoidance at the other 2 sites. This result suggested that muskrats may be using a strategy to maximize energy by choosing prey of a particular size, but in locations where larger prey items are not available they will accept smaller species that may normally be considered a marginal prey.