Medionidus simpsonianus Walker, 1905

Ochlockonee moccasinshell



Taxonomy & Nomenclature



Conservation Status

Last record: 1993 (Suckling et al. 2004)

Rediscovered in 2007

IUCN RedList status: Critically Endangered



Ochloknee River system, Florida & Georgia, USA


Biology & Ecology










Graf, Daniel L. and Cummings, Kevin S. (2021). A ‘big data’ approach to global freshwater mussel diversity (Bivalvia: Unionoida), with an updated checklist of genera and species. Journal of Molluscan Studies 87(1): eyaa034.

Suckling, Kieran, Slack, Rhiwena and Nowicki, Brian. (2004). Extinct and the Endangered Species Act. Centre For Biological Diversity. 63 pp.

USFWS. 2003. Recovery Plan for endangered fat threeridge (Amblema neislerii), shinyrayed pocketbook (Lampsilis subangulata), gulf moccasinshell (Medionidus penicillatus), Ochlockonee moccasinshell (Medionidus simpsonianus), and oval pigtoe (Pleurobema pyriforme); and threatened chipola slabshell (Elliptio chipolaensis), and purple bankclimber (Elliptoideus sloatianus). U.S. Fish and Wildlife Service, Southeast Region, Atlanta, Georgia. 142 pp. Available at:


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