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Presented at the NABS Annual meeting, Athens, Georgia, 2003
in Molecular Approaches to Population Structure and Bioassessment
Hierarchical analysis of mtDNA variation in two widespread mussel species
C.L. Elderkin1, D.J. Berg2, J.L. Metcalfe-Smith3, C.C. Vaughn4, and S.I. Guttman1. 1Department of Zoology, Miami University, Oxford, Ohio 45056, 2Department of Zoology, Miami University, Hamilton, Ohio 45011, 3National Water Research Institute, Environment Canada, Burlington, Ontario, Canada L7R 4A6, 4Department of Zoology and Oklahoma Biological Survey, University of Oklahoma, Norman, Oklahoma 73019
Knowledge of genetic structure of target species is essential for the development of effective conservation plans. Amblema plicata and Eliptio dilatata are common, widespread freshwater mussel species. However, A. plicata are habitat generalists, whereas E. dilatata are generally restricted to headwater habitats. We sequenced mtDNA from ~10 individuals in two populations, from two rivers in each of three distinct drainages: Northern Lake Erie, Ohio River, and Ouachita River (for a total of twelve populations). We used this hierarchical design to estimate percent variation at four levels: within populations, among populations within river, among rivers within drainage, and among drainages. We sequenced a 652-base portion of the mitochondrial cytochrome oxidase I (COI) gene. Multiple haplotypes were identified for both species, and unique sequences were found in southern populations, indicating that these populations are much older. Also, for E. dilatata we found 4X the variation among rivers and among drainages than for A. plicata. These results suggest that genetic drift has had a more profound effect on E. dilatata than on A. plicata populations. Overall, management decisions for habitat specialists may involve a much larger geographic scale than for generalists, in order to preserve the genetic variation present in these species.
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