Status of Three Species of Freshwater Snails (Gastropoda: Pleuroceridae) in the Lower Ohio River Basin, Illinois

Illinois Department of Natural Resources Wildlife Preservation Fund Grant/Contract No: RC08-L20WWe report on a status survey of Lithasiaspp. (Gastropoda:Pleuroceridae) we conducted in the Ohio River basin, Illinois. Prior to oursurvey, only three Lithasiaspecies were known to occur in Illinois; however,through our efforts, we found a fourth species (Lithasia geniculata). Thedistribution of L. armigeraand L. verrucosadoes not appear to have changedwithin Illinois, whereas the distribution of L. obovataappears to be declining inIllinois, which prompted us to nominate it for inclusion on the state list ofendangered and threatened species for Illinois by the Illinois Endangered SpeciesProtection Board.Lithasia geniculatahas been recorded only in one location, andwe feel it should be considered for state endangeredINHS Technical Report Prepared for Illinois Department of Natural Resources Wildlife Preservation Fun