Present address: Department of Biological Sciences, Arkansas State University, State University, AR 72467, USA.
Population genetics and phylogeography of freshwater mussels in North America, Elliptio dilatata and Actinonaias ligamentina (Bivalvia: Unionidae)
Article first published online: 11 APR 2008
© 2008 The Authors. Journal compilation © 2008 Blackwell Publishing Ltd
Volume 17, Issue 9, pages 2149–2163, May 2008
How to Cite
ELDERKIN, C. L., CHRISTIAN, A. D., METCALFE-SMITH, J. L. and BERG, D. J. (2008), Population genetics and phylogeography of freshwater mussels in North America, Elliptio dilatata and Actinonaias ligamentina (Bivalvia: Unionidae). Molecular Ecology, 17: 2149–2163. doi: 10.1111/j.1365-294X.2008.03745.x
- Issue published online: 11 APR 2008
- Article first published online: 11 APR 2008
- Received 2 November 2007; revision received 6 February 2008; accepted 11 February 2008
- genetic diversity;
- population genetics;
- postglacial dispersal;
Extrinsic and intrinsic forces combined shape the population structure of every species differently. Freshwater mussels are obligate parasites to a host fish during a juvenile stage (glochidia). Elliptio dilatata (ED) and Actinonaias ligamentina (AL) are co-occurring freshwater mussel taxa with similar North American distribution and share some potential host fish. Using mitochondrial DNA, we determined the genotypes of 190 + individuals from collection sites in at least two tributaries in the Lake Erie and Ohio River watersheds, along with the Ouachita and Strawberry rivers in the southeast. Both species had followed a stepping-stone model of dispersal, with greater pairwise genetic structure among collection sites of ED. Also, phylogeographical analysis for ED found significant geographical structuring of haplotype diversity. Overall, within-population variation increased significantly from north to south, with low genetic diversity in the Strawberry River. We calculated significant among-population structure for both species (ED: ΦST = 0.62, P < 0.001; AL: ΦST = 0.16, P < 0.001). Genetic analysis identified the Ouachita River as an area of significant reproductive isolation for both species. Results for AL indicated dispersal into northern areas from two genetically distinct glacial refugia, where results for ED indicated dispersal followed by low gene flow in northern areas. The conservation strategies for mussels that co-occur in the same ‘bed’ could be species specific. Species such as ED have management units on the population scale, where AL has a more homogeneous genetic structure across its range.