Cyprogenia aberti

Cyprogenia aberti, the western fanshell, edible naiad, edible pearly mussel, or western fanshell mussel, is a species of freshwater mussel, an aquatic bivalve mollusk in the family Unionidae, the river mussels.
This species is endemic to the United States, and is found in the Lower Mississippi-St. Francis, Neosho-Verdigris and Upper White River basins within Arkansas, Kansas, Missouri and Oklahoma.
It has a thick, round to triangular shell that is up to long. The fish hosts for the larval stage include logperch. Slenderhead darter, fantail darter, rainbow darter, and orangebelly darter are also good hosts provided they are from the same stream as the mussel.
In 2023 it was listed as a Threatened species under the Endangered Species Act. Water quality degradation, altered stream flow, landscape changes, and habitat fragmentation, all of which are exacerbated by the effects of climate change, are the main threats to this species.