Freshwater Mussels (Unionidae) in Streams of Northwestern Kansas

The Kansas River System currently represents the western range limit for 9 species of freshwater mussel, although 24 species were reported historically. The purpose of this study was to assess the current status of native mussels (Unionidae) and the Asian clam, Corbicula fluminea, in northwestern Kansas. I sampled 81 sites in the Saline, Smoky Hill, Solomon, and Republican river basins in Kansas. In addition to the non-indigenous Asian clam, 16 unionid species were collected. Potamilus ohiensis, Quadrula quadrula, Leptodea fragilis, and Corbicula fluminea were common within the study area, whereas six species were uncommon or rare. Seven unionid species were collected as weathered shells only. Anodontoides ferussacianus, a species in need of conservation (SNIC), was collected from the Saline and Smoky Hills rivers. Many species have suffered range reductions within the study area, however, the Asian clam’s range is expanding westward in the Solomon, Saline, and Smoky Hill rivers. Postulated causes for the declining mussel fauna include climate change, pollution, excessive siltation, construction of impoundments, and the loss of host fish