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Endangered Species Program
Conserving and restoring threatened and endangered species and their ecosystems
Status: Endangered, listed October 9, 2001
The scaleshell is a relatively small freshwater mussel that historically occurred across most of the eastern United States. During the last 60 years this mussel became increasingly rare within a reduced range. Of the 55 historical populations, 14 remain scattered within the Mississippi River basin in Arkansas, Missouri, and Oklahoma.
Scaleshell live in medium-sized and large rivers with stable channels and good water quality. They bury themselves in sand and gravel on the bottom with only the edge of their partially-opened shells exposed. As river currents flow over them, they siphon particles out of the water for food such as plant debris, plankton, and other microorganisms. The roles of scaleshell in river ecosystems are as food for wildlife like muskrats, otters, and raccoons and as filters which improve water quality.
Scaleshell Mussel 5-Year Review : 19-page PDF; 920KB (March 2011)
Final Recovery Plan - February 2010
News Release (April 7, 2010): Recovery Plan Outlines Steps to Help Rare Mussel
Natural History, Ecology, and Regulatory Information
Last updated: February 11, 2019