The pale lilliput naiad, pale lilliput pearly mussel, or pale lilliput, scientific name Toxolasma cylindrellus, is a species

Species

In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...

 of freshwater mussel, an aquatic

Aquatic animal

An aquatic animal is an animal, either vertebrate or invertebrate, which lives in water for most or all of its life. It may breathe air or extract its oxygen from that dissolved in water through specialised organs called gills, or directly through its skin. Natural environments and the animals that...

 bivalve mollusk in the family Unionidae

Unionidae

Unionidae is a family of freshwater mussels, the largest in the order Unionoida, the bivalve mollusks sometimes known as river mussels, naiads, or simply as unionids.The range of distribution for this family is world-wide...

, the river mussels.

Distribution

This species is endemic to the United States

United States

The United States of America is a federal constitutional republic comprising fifty states and a federal district...

. It has experienced a great range reduction and is currently found only in the Paint Rock River

Paint Rock River

The Paint Rock River is a tributary of the Tennessee River in northern Alabama in the United States. Its tributaries also drain a portion of south-central Tennessee....

 drainage in northern Alabama

Alabama

Alabama is a state located in the southeastern region of the United States. It is bordered by Tennessee to the north, Georgia to the east, Florida and the Gulf of Mexico to the south, and Mississippi to the west. Alabama ranks 30th in total land area and ranks second in the size of its inland...

 and southeastern Tennessee

Tennessee

Tennessee is a U.S. state located in the Southeastern United States. It has a population of 6,346,105, making it the nation's 17th-largest state by population, and covers , making it the 36th-largest by total land area...

. The most recent surveys failed to find this species in the Tennessee portion of the drainage.

External links

• Toxolasma cylindrellus. The Nature Conservancy.
• Bogan, A.E. 1996. Toxolasma cylindrellus. 2011 IUCN Red List of Threatened Species. Downloaded on 19 September 2011.