The oval pigtoe, scientific name Pleurobema pyriforme, is a federally endangered 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.

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...

 in the states of Georgia, Florida, and Alabama .

The oval pigtoe was originally described from the Chattahoochee River

Chattahoochee River

The Chattahoochee River flows through or along the borders of the U.S. states of Georgia, Alabama, and Florida. It is a tributary of the Apalachicola River, a relatively short river formed by the confluence of the Chattahoochee and Flint Rivers and emptying into Apalachicola Bay in the Gulf of...

 near Columbus, Georgia

Columbus, Georgia

Columbus is a city in and the county seat of Muscogee County, Georgia, United States, with which it is consolidated. As of the 2010 census, the city had a population of 189,885. It is the principal city of the Columbus, Georgia metropolitan area, which, in 2009, had an estimated population of 292,795...

. Historically, this mussel was very abundant in the Flint River

Flint River (Georgia)

The Flint River is a river in the U.S. state of Georgia. The river drains of western Georgia, flowing south from the upper Piedmont region south of Atlanta to the wetlands of the Gulf Coastal Plain in the southwestern corner of the state. Along with the Apalachicola and the Chattahoochee rivers,...

 in Georgia, the Chattahoochee River in Georgia and 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...

, the Chipola River

Chipola River

The Chipola River is a tributary of the Apalachicola River in Florida. The river crosses Jackson, Calhoun and Gulf counties. The river flows into the Dead Lakes State Recreation Area just before reaching the Apalachicola. The Dead Lakes were formed when the Apalachicola deposited sand bars...

 in Alabama and Florida

Florida

Florida is a state in the southeastern United States, located on the nation's Atlantic and Gulf coasts. It is bordered to the west by the Gulf of Mexico, to the north by Alabama and Georgia and to the east by the Atlantic Ocean. With a population of 18,801,310 as measured by the 2010 census, it...

, the Ochlockonee River

Ochlockonee River

The Ochlockonee River is a fast running river originating in Georgia and flowing for before terminating in Florida.- Background :The Ochlockonee originates south of the town of Sylvester in Worth County in southwest Georgia emptying into Ochlockonee Bay, then into Apalachee Bay, in Florida...

 in Georgia and Florida, the Apalachicola River

Apalachicola River

The Apalachicola River is a river, approximately 112 mi long in the State of Florida. This river's large watershed, known as the ACF River Basin for short, drains an area of approximately into the Gulf of Mexico. The distance to its farthest headstream in northeast Georgia is approximately 500...

 and Suwanee/Santa Fe River

Santa Fe River

The Santa Fe River is a river in northern Florida. The watershed of the river is approximately and spreads across southern Columbia, southern Suwannee, western Bradford, far southern Baker, Union, northern and eastern Gilchrist, and northern Alachua counties. The headwaters of the river are...

s in Florida, and Econfina Creek

Econfina Creek

Econfina Creek is a small river in the middle Florida Panhandle. It flows through hilly country, and has sections of whitewater rapids. Much of its flow comes from springs...

in Florida. However, the populations in all river systems have declined significantly due to land use changes, development, and the construction of dams.

Source

• Bogan, A.E. 2000. Pleurobema pyriforme. 2006 IUCN Red List of Threatened Species. Downloaded on 7 August 2007.