SREL Reprint #2215

Conservation genetics of North American freshwater mussels Amblema and Megalonaias

Margaret Mulvey1, Charles Lydeard2, Debra L. Pyer1, Kimberly M. Hicks1, Jayne Brim-Box3, James D. Williams3,
and Robert S. Butler4

1Savannah River Ecology Laboratory, Drawer E, Aiken, SC 29802, USA
2Department of Biological Sciences, University of Alabama, Tuscaloosa, AL 35487, USA
3USGS, Biological Resources Division, Gainesville, FL 32606, USA
4U. S. Fish and Wildlife Service, Asheville Field Office, 160 Zillicoa Street, Asheville, NC 28801, USA

Abstract: Freshwater bivalves are among the most endangered groups of organisms in North America. Efforts to protect the declining mussel fauna are confounded by ambiguities associated with recognition of distinct evolutionary entities or species. This, in part, is due to the paucity of reliable morphological characters for differentiating taxa. We have employed allozymes and DNA sequence data to search for diagnosable distinct evolutionary entities within two problematic genera of unionid mussels, Amblema and Megalonaias. Within the genus Amblema three species are recognized based on our DNA sequence data for the mitochondrial 16S rRNA and allozyme data (Amblema neislerii, A. plicata, and A. elliotti). Only one taxonomically distinct entity is recognized within the genus Megalonaias—M. nervosa Megalonaias boykiniana of the Apalachicolan Region is not diagnosable and does not warrant specific taxonomic status. Interestingly, Megalonaias from west of the Mississippi River, including the Mississippi, exhibited an allozyme and mtDNA haplotype frequency shift suggestive of an east-west dichotomy. The results of this study eliminate one subspecies of Amblema and increase the range of A. plicata. This should not affect the conservation status of "currently stable" assigned to A. plicata by Williams et al (1993). The conservation status of A. elliotti needs to be reexamined because its distribution appears to be limited to the Coosa River System in Alabama and Georgia.

SREL Reprint #2215

Mulvey, M., C. Lydeard, D.L. Pyer, K.M. Hicks, J. Brim-Box, J.D. Williams, and R.S. Butler. 1997. Conservation genetics of North American freshwater mussels Amblema and Megalonaias. Conservation Biology 11:868-878.

This information was provided by the University of Georgia's Savannah River Ecology Laboratory (srel.uga.edu).