Theliderma sparsa, the Appalachian Rockshell pearly mussel or Appalachian rockshell, is a species of freshwater mussel, an aquatic bivalve mollusk in the family Unionidae, the river mussels.

This species is endemic to western Virginia and eastern Tennessee in the Appalachia region, in the Southeastern United States.

It is critically endangered due to pollution of the rivers in which it lives. Being a detritivore, the mussel absorbs the pollutants which contaminate the river as it feeds.

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