Natural Resources, School of


Date of this Version



Project funded 1992–1997 by the U.S. Fish and Wildlife Service, Grand Island, Nebraska. Copyright 1997, the authors. Used by permission.


We surveyed the mollusks of the Niobrara River in Nebraska from 1992–1996. We found two species of unionid clams and ten species of snails that either must live in water or near water. Both clams and snails are poorly sampled in the state, however we attribute the low number of species of unionid clams in the Niobrara to its cold, fast flow and rocky bottom. In contrast, the Platte River is slower moving with a muddy bottom and has at least 11 species of unionid clams. Each species has been mapped with latitude/longitude coordinates. Specimens have been curated and are housed in the Division of Zoology of the University of Nebraska State Museum.