The Unionidae are a family of freshwater mussels, the largest in the order Unionida, the bivalve molluscs sometimes known as river mussels, or simply as unionids.
Unionida is a monophyletic order of freshwater mussels, aquatic bivalve molluscs. The order includes most of the larger freshwater mussels, including the freshwater pearl mussels. The most common families are the Unionidae and the Margaritiferidae. All have in common a larval stage that is temporarily parasitic on fish, nacreous shells, high in organic matter, that may crack upon drying out, and siphons too short to permit the animal to live deeply buried in sediment.
Cyprogenia is a genus of freshwater mussels, aquatic bivalve mollusks in the family Unionidae.
Dromus dromas, the dromedary pearlymussel or dromedary naiad, is a rare species of freshwater mussel in the family Unionidae. This aquatic bivalve mollusk is native to the Cumberland and Tennessee River systems in the United States, where it has experienced a large population decline. It is a federally listed endangered species of the United States.
Epioblasma is a genus of freshwater mussels, aquatic bivalve mollusks in the family Unionidae, the river mussels. Most of the species in this genus have been lost in modern times, and the entire genus is threatened with the possibility of extinction.
Lampsilis cardium is a species of freshwater mussel in the family Unionidae, the river mussels. It is known commonly as the plain pocketbook. It is widespread in eastern North America, where it is native to the Mississippi River and Great Lakes drainage systems.
Margaritifera auricularia is a species of European freshwater mussel, an aquatic bivalve mollusk in the family Margaritiferidae, the freshwater pearl mussels. Formerly found throughout western and central Europe, the species is now critically endangered, being confined to a few rivers in Spain and France. M. auricularia is commonly known as Spengler's freshwater mussel in honour of Lorenz Spengler, who first described this species.
Pleurobema oviforme, the Tennessee clubshell, is a species of freshwater mussel in the family Unionidae, the river mussels. It is native to the eastern United States, where it occurs in Alabama, Kentucky, North Carolina, Tennessee, and Virginia. It also previously occurred in Mississippi.
Popenaias popeii, common name the Texas hornshell, is a species of freshwater mussel, an aquatic bivalve mollusk in the family Unionidae, the river mussels.
Ptychobranchus fasciolaris is a species of freshwater mussel in the family Unionidae, the river mussels. Its common name is kidneyshell.
The triangular kidneyshell is a species of freshwater mussel, in the family Unionidae, the river mussels. It is endemic to Alabama in the United States, where it is known from several rivers and streams in the Mobile River Basin. It is a federally listed endangered species of the United States.
The southern kidneyshell is a species of freshwater mussel, an aquatic bivalve mollusk in the family Unionidae, the river mussels.
Ptychobranchus occidentalis is a species of freshwater mussel in the family Unionidae, the river mussels. It is endemic to the United States, where it is known from Arkansas, Kansas, Louisiana, Missouri, and Oklahoma. Its common name is Ouachita kidneyshell.
Ptychobranchus subtentum, also known as the fluted kidneyshell, is a species of freshwater mussel, an aquatic bivalve mollusk in the family Unionidae, the river mussels.
The glochidium is a microscopic larval stage of some freshwater mussels, aquatic bivalve mollusks in the families Unionidae and Margaritiferidae, the river mussels and European freshwater pearl mussels.
Epioblasma triquetra, common name the snuffbox mussel, is a species of freshwater mussel, a mollusk in the family Unionidae. It is native to eastern North America, where it is a listed as an endangered species in both Canada and the United States.
Villosa iris, the rainbow mussel or rainbow-shell, is a species of freshwater mussel, an aquatic bivalve mollusk in the family Unionidae, the river mussels.
Strophitus undulatus is a species of mussel in the Unionidae, the river mussels. It is native to eastern Canada and the eastern United States. Its common names include creeper, squawfoot, sloughfoot, and strange floater.
Fusconaia flava, the Wabash pigtoe, is a freshwater mussel in the family Unionidae.
Megalonaias nervosa is a freshwater mussel species in the family Unionidae. Washboard is the common name used for Megalonaias nervosa.
