''Pleurobema clava'', the clubshell, club naiad or clubshell pearly mussel, is a

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

of freshwater mussel, an aquatic

bivalve Bivalvia (), in previous centuries referred to as the Lamellibranchiata and Pelecypoda, is a class of marine and freshwater molluscs that have laterally compressed bodies enclosed by a shell consisting of two hinged parts. As a group, bival ...

mollusk Mollusca is the second-largest phylum of invertebrate animals after the Arthropoda, the members of which are known as molluscs or mollusks (). Around 85,000 extant species of molluscs are recognized. The number of fossil species is e ...

in the family Unionidae, the river mussels. This species is

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsew ...

to the

United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territorie ...

. It is a federally protected endangered species and is listed under Appendix I of the Convention on International Trade in Endangered Species of Wild Flora and Fauna. Clubshells prefer clean, loose sand and gravel in medium to small rivers and streams, burying themselves in the bottom substrate to depths of up to four inches. Once settled in, clubshells are long-lived, living possibly up to 50 years. Clubshells are endangered, most likely because of agricultural run-off, industrial waste, mining of streams for gravel and sand,

impoundment Impoundment may refer to: Water control * The result of a dam, creating a body of water ** A reservoir, formed by a dam ** Coal slurry impoundment, a specialized form of such a reservoir used for coal mining and processing * Impounded dock, an enc ...

and the proliferation of the exotic invasive species the zebra mussel. Prior to its endangered status, clubshells could be found in the Ohio, Cumberland, and Tennessee River systems, and Lake Erie drainages. Currently, however, these mussels can be found in the United States in the states of Illinois, Indiana, Kentucky, Michigan, New York, Ohio, Pennsylvania, Tennessee, and West Virginia. At the time of its listing under the

Endangered Species Act of 1973 The Endangered Species Act of 1973 (ESA or "The Act"; 16 U.S.C. § 1531 et seq.) is the primary law in the United States for protecting imperiled species. Designed to protect critically imperiled species from extinction as a "consequence of ec ...

in 1993, ''P. clava'' was likely limited to no more than twelve rivers or streams.

References

{{Taxonbar, from=Q1054605 Molluscs of the United States clava Bivalves described in 1819 ESA endangered species Taxonomy articles created by Polbot