Plethobasus cicatricosus (Say, 1829)

White warty-back pearly mussel, White wartyback



Taxonomy & Nomenclature

Synonym/s: Plethobasus pachosteus Morrison, 1969; Unio cicatricosus Say, 1829; Unio detectus Frierson, 1911; Unio varicosus Lea, 1831


Conservation Status


Last record: 1982

IUCN RedList status: Critically Endangered



Tennessee, USA


Biology & Ecology










Boepple, J.F. and Coker, R.E. 1912. Mussel resources of the Holston and Clinch rivers of eastern Tennessee. U.S. Bureau of Fisheries [Issued separately as U.S. Bureau of Fisheries Document 765] 1911: 1-13.

Bogan, A. and Parmalee, P. 1983. Tennessee's rare mollusks. Tennessee's rare wildlife. Tennessee Department of Conservtaion and Tennessee Heritage Program, Univeristy of TN, Knoxville.

Cicerello, R.R. and Schuster, G.A. 2003. A guide to the freshwater mussels of Kentucky. Kentucky State Nature Preserves Commission Scientific and Technical Series 7(1-62).

Coker, R.E., Shira, A.F., Clark, H.W. and Howard, A.D. 1921. Natural history and propagation of fresh-water mussels. Bulletin of the Bureau of Fisheries. [Issued separately as U.S. Bureau of Fisheries Document 839] 37(1919-1920): 77-181.

Cummings, K.S. and Mayer, C.A. 1992. Field guide to freshwater mussels of the Midwest. Illinois Natural History Survey Manual 5, Illinois.

Cummings, K.S. and Mayer, C.A. 1997. Distributional checklist and status of Illinois freshwater mussels (Mollusca: Unionacea). Conservation and management of freshwater mussels II: initiatives for the future, pp. 129-145. Upper Mississippi River Conservation Committee, Rock Island, Illinois, St. Louis, Missouri.

Evermann, B.W. and Clark, H.W. 1918. The Unionidae of Lake Maxinkukee. Proceedings of the Indiana Academy of Science 1917: 251-285.

Fisher, B.E. 2006. Current status of freshwater mussels (Order Unionoida) in the Wabash River drainage of Indiana. Proceedings of the Indiana Academy of Science 115(2): 103-109.

Frierson, L.S. 1911. Remarks on Unio varicosus, Cicatricosus and Unio compertus, new species. The Nautilus 25(5): 51-54.

Graf, D.L. and Cummings, K.S. 2011. The MUSSEL Project Database: MUSSELp. Available at: (Accessed: 21 July 2018).

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.

Heard, W.H. 1970. Eastern freshwater mollusks. 1. The south Atlantic and Gulf drainages. In: Clarke, A.H. (ed.), Rare and endangered molluscs of North America, pp. 1-56. Malacologia.

Horne, F.R. and McIntosh, S. 1979. Factors influencing distribution of mussels in the Blanco River of central Texas. The Nautilus 94(4): 119-133.

Meek, S.E. and Clark, H.W. 1912. The mussels of the Big Buffalo Fork of White River, Arkansas. U.S. Fish Commission [Issued separately as U.S. Bureau of Fisheries Document 759] 1911: 1-20.

Mirarchi R.E., Garner J.T., Mettee and O'Neil P.E. 2004. Imperiled Aquatic Mollusks and Fishes. Alabama Wildlife 2.

Ortmann, A.E. 1919. A monograph of the naiades of Pennsylvania. Part III. Systematic account of the genera and species. Memoirs of the Carnegie Museum 8: 1–385.

Ortmann, A.E. and Walker, B. 1922. On the nomenclature of certain North American naiades. Occasional Papers of the Museum of Zoology, University of Michigan 112: 1-75.

Parmalee, P.W. 1967. The freshwater mussels of Illinois. Illinois State Museum.

Parmalee P.W. and Bogan A.E. 1998. The Freshwater Mussels of Tennessee. University of Tennessee Press, Knoxville Tennessee.

Simpson, C.T. 1899. The pearly fresh-water mussels of the United States; their habits, enemies, and diseases, with suggestions for their protection. Bulletin of the U.S. Fish Commission [Issued separately as U.S. Bureau of Fisheries Document 413] 18: 279-288.

Smith, P.W. 1971. Illinois streams: a classification based on their fishes and an analysis of factors responsible for disappearance of native species. Illinois Natural History Survey Biological Notes 76: 1-14.

Snyder, N. and Snyder, H. 1969. A comparative study of mollusk predation by Limpkins, Everglade Kites, and Boat-tailed Grackles. Eighth Annual Report of the Cornell Laboratory of Ornithology.

Turgeon, D.D., Quinn, Jr. J.F., Bogan, A.E., Coan, E.V., Hochberg, F.G., Lyons, W.G., Mikkelsen P.M., Neves, R.J., Roper, C.F.E., Rosenberg, G., Roth, B., Scheltema, A., Thompson, F.G., Vecchione, M. and Williams, J.D. 1998. Common and scientific names of aquatic invertebrates from the United States and Canada. American Fisheries Society, Mollusks.

U.S. Fish and Wildlife Service (USFWS). 1984. Recovery plan for the white warty-back pearly mussel (Plethobasus cicatricosus) (Say 1829). In: Ahlstedt, S.A. (ed.), Region 4. USFWS, Atlanta, Georgia.

U.S. Fish and Wildlife Service (USFWS). 1989. Endangered and threatned wildlife and plants; Proposal to list the cracking pearly-mussel as an Endangered Species. Federal Register 54(32): 7225-7229.

U.S. Fish and Wildlife Service (USFWS). 2006. Endangered and threatened wildlife and plants; establishment of nonessential experimental population status for 15 freshwater mussels, 1 freshwater snail, and 5 fishes in the lower French Broad River and in the lower Holston River, Tennessee; Proposed Rule. Federal Register 71 (113). USFWS, Tennessee.

Williams, J.D., Bogan, A.E. and Garner, J.T. 2008. Freshwater Mussels of Alabama and the Mobile Basin in Georgia, Mississippi and Tennessee. University of Alabama Press, Tuscaloosa, Alabama.

Williams, J.D., Warren, M.L.Jr., Cummings, K.S., Harris, J.L. and Neves, R.J. in press. Conservation status of freshwater mussels of North America and Mexico.


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