The U.S. Fish and Wildlife Service (Service) has listed (pdf) the Neosho mucket (Lampsilis rafinesqueana) as endangered and the rabbitsfoot (Quadrula cylindrica cylindrica) as threatened under the Endangered Species Act (ESA).  Both are species of freshwater mussels found in river systems in the eastern half of the United States.

The Service reported that of 16 historical populations of Neosho mucket, only nine remain extant, and of those all but one is declining in numbers.  The Neosho mucket has been extirpated from appriximately 62 percent of its historical range.  Similarly, the rabbitsfoot has been extirpated from approximately 64 percent of its historical range, with only 11 of the 140 historical populations remaining viable.

River damming was cited as the primary cause of the species' decline.  Mining activities, stream dredging, and water pollution were also listed as contibuting factors.

The Service stated that it will make a final determination on critical habitat for these species in the near future.