Genetics and taxonomy of ribbed mussels (Geukensia spp.)
- Cite this article as:
- Sarver, S.K., Landrum, M.C. & Foltz, D.W. Marine Biology (1992) 113: 385. doi:10.1007/BF00349163
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Ribbed mussels (232 in all) representing the nominal species Geukensia demissa (Dillwyn, 1817) were collected at nine coastal North American locations (two Pacific, four Atlantic and three Gulf Coast locations) between January 1990 and September 1991, and examined for nine shell characters and for variation at 18 allozyme loci. Two genetically-differentiated groups were identified and called demissa-type and granosissima-type mussles, based on similarity of geographic range to previously recognized subspecies of G. demissa. There was very little genetic differentiation of populations over moderate to large (3000 km) distances along the Atlantic coast (for demissa-type mussels), along the Gulf Coast (for granosissima-type mussels), or between Pacific and Atlantic populations of demissa-type mussles. The two types of mussels were differentiated genetically (Nei's unbiased genetic distance =0.55±0.20) at a level characteristic of separate species in other molluscan taxa, and to a lesser extent were differentiated morphologically. We recommend that the two types of mussels be treated as separate species within the genus Geukensia: G. demissa (Dillwyn, 1817) and G. granosissima (Sowerby, 1914).