Date of this Version
Surveys in the Elkhorn River Basin between 1972 and 1994 documented a unionid fauna of 28 taxa. Two additional taxa were documented by museum records, bringing the total to 30 confirmed for the region. In recent collections only eleven species were found as live specimens or fresh shells, suggesting the possible loss of as much as 63% of the documented fauna of the Basin. Biological diversity was once greatest in the eastern portion of the Basin, reflecting the greater variety of habitats in this region. At present, the greatest diversity appears to be found in the western portion. This reversal of biologic diversity probably reflects the extent of habitat degradation in the eastern portion. Arcidens confragosus, Lampsilis teres f. teres, and Obovaria olivaria are newly reported for Nebraska.