Muskrat predation on a diverse unionid mussel community: impacts of prey species composition, size and shape
1. The muskrat, Ondatra zibethicus, is a predator known to affect species composition, population size and age structure of freshwater unionid mussel communities. Muskrats leave large piles of dead shells (middens) on the edges of rivers, lakes and streams. We compared the species composition and si...
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Published in | Freshwater biology Vol. 56; no. 3; pp. 554 - 564 |
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Main Authors | , , , |
Format | Journal Article |
Language | English |
Published |
Oxford, UK
Blackwell Publishing Ltd
01.03.2011
Wiley Subscription Services, Inc |
Subjects | |
Online Access | Get full text |
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Summary: | 1. The muskrat, Ondatra zibethicus, is a predator known to affect species composition, population size and age structure of freshwater unionid mussel communities. Muskrats leave large piles of dead shells (middens) on the edges of rivers, lakes and streams. We compared the species composition and size structure of shells collected from muskrat middens to the nearby live unionid community in the lower Licking River (Kentucky, USA). 2. Like previous studies, our results suggest that muskrats are both size-selective and species-specific predators; however, our results indicate that mussel shape is also an important factor. 3. We generated a shape metric (‘cubocity') sensitive to the overall shape of the mussel. Species with relatively lower cubocity values (around 0.85) are plate-like or spike-like, while mussels with more cuboidal shells have higher cubocity values (near 1.0). 4. Our results suggest muskrats prefer cuboidal mussels and generally avoid spike-shaped mussels. The endangered fanshell, Cyprogenia stegaria, was the most favoured prey; the fanshell's relative size and shape appear to make it particularly vulnerable to muskrats. 5. We believe the predictive capabilities of this shape metric will be of benefit to those who monitor and manage threatened mussel populations. |
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Bibliography: | http://dx.doi.org/10.1111/j.1365-2427.2010.02523.x ArticleID:FWB2523 istex:2C1AC2A61CF735962F066503FB8BA081EE3D0335 ark:/67375/WNG-5PM33F67-9 Present address: Christopher T. Owen, Division of Aquaculture, Kentucky State University, Frankfort, KY 40601, U.S.A. ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
ISSN: | 0046-5070 1365-2427 |
DOI: | 10.1111/j.1365-2427.2010.02523.x |