Prior studies recognized the presence of a single dreissenid species in Lake Superior - the zebra mussel Dreissena polymorpha. However, taxonomic keys based on traditional shell morphology are not always able to differentiate dreissenid species with confidence. We thus employed genetic and morphological analyses to identify dreissenids in a major river-embayment of Lake Superior - the lower St. Louis River/Duluth-Superior Harbor - during 2005-2006. Our results revealed the presence of a second dreissenid species - the quagga mussel D. bugensis (alternatively known as D. rostriformis bugensis). Both species occurred in mixed clusters, in which zebra mussels outnumbered quagga mussels (20-160:1). The largest quagga mussel collected in 2005 was 26.5 mm long and estimated to be two years old, suggesting that the initial introduction occurred no later than 2003. Further monitoring is necessary to determine whether the quagga mussel will colonize Lake Superior. Our results indicate that the coupling of conventional morphological and molecular approaches is essential for monitoring dreissenid species.
|Original language||English (US)|
|Number of pages||9|
|Journal||Journal of Great Lakes Research|
|State||Published - 2008|
Bibliographical noteFunding Information:
We thank Kevin Stroom for assistance with photographs. We also thank Dan Molloy, Ron Dermott, Ted Angradi, Tim Dawson, Mary Ann Starus, and an anonymous reviewer for helpful comments on a previous version of this manuscript. This study was funded by the U.S. Environmental Protection Agency. It has been subjected to review by the National Health and Environmental Effects Laboratory and approved for publication. Approval does not signify that the contents reflect the views of the agency and no official endorsement should be inferred.
Copyright 2017 Elsevier B.V., All rights reserved.
- Dreissena bugensis
- Dreissena rostriformis
- Duluth-Superior Harbor
- Lake Superior
- Non-indigenous species
- Quagga mussel
- Range expansion