''Epioblasma'' is a

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

freshwater mussel Freshwater bivalves are one kind of freshwater mollusc, along with freshwater snails. They are bivalves that live in fresh water as opposed to salt water, which is the main habitat type for bivalves. The majority of species of bivalve molluscs ...

s, 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 ...

s in the family

Unionidae 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. The range of distribution for this family is world-wide. It is at its most diverse ...

, 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.

Reproduction

All Unionidae are known to use the gills, fins, or skin of a host fish for nutrients during the larval glochidia stage. It was discovered in 2004 that female ''Epioblasma'' in the subgenus ''Torulosa'' transfer their parasitic larvae to the host fish by snapping onto the head of the fish and pumping the larvae into the host fish's gills. While using bait to lure host fish towards the larvae is common in the family Unionidae, this was the first time that "fish snapping" behavior had been observed. Examination of other species within the genus ''Epioblasma'' may further reveal unusual reproductive mechanisms.

Taxonomy of the genus ''Epioblasma''

Note: Taxa with a " †" symbol are extinct due to human activity *Subgenus †''Epioblasma'' **†'' Epioblasma flexuosa'' - Leafshell **†'' Epioblasma lewisii'' - Forkshell **†'' Epioblasma stewardsonii'' - Cumberland leafshell *Subgenus ''Pilea'' **†'' Epioblasma haysiana'' - Acornshell **''

Epioblasma obliquata ''Epioblasma obliquata'', commonly called the catspaw, is a species of freshwater mussel. It is native to eastern North America, where it is classified as endangered under the Endangered Species Act. Natural history and conservation This specie ...

'' ***''Epioblasma obliquata obliquata'' - Purple catspaw ***''Epioblasma obliquata perobliqua'' - White catspaw **†'' Epioblasma personata'' - Round combshell *Subgenus ''Plagiola'' **†'' Epioblasma arcaeformis'' - Sugarspoon **''

Epioblasma brevidens The Cumberlandian Combshell (''Epioblasma brevidens'') is a species of freshwater mussel, an aquatic bivalve mollusk in the family Unionidae. This species is endemic to the United States, found mainly in the states of Tennessee and Virginia. Thi ...

'' - Cumberlandian combshell **†''

Epioblasma lenior ''Epioblasma lenior'', the narrow catspaw or Stone's pearly mussel, was a species of freshwater mussel, an aquatic bivalve mollusk in the family Unionidae, the river mussels. This species was endemic to the Tennessee River system in the United ...

'' - Narrow catspaw **''

Epioblasma metastriata The upland combshell (''Epioblasma metastriata'') was a species of freshwater mussel in the family Unionidae. It was endemic to the upper Mobile River Basin in the southeastern United States. This species was found only in the shoals of rivers ...

'' - Upland combshell **'' Epioblasma othcaloogensis'' - Southern acornshell **'' Epioblasma penita'' - Southern combshell *Subgenus ''Torulosa'' **''

Epioblasma ahlstedti ''Epioblasma ahlstedti'', commonly called the Duck River dartersnapper, is a species of freshwater mussel, an aquatic bivalve mollusk in the family Unionidae, the river mussels. It is native to Alabama and Tennessee in the southeastern United S ...

'' - Duck River oyster mussel **†''

Epioblasma biemarginata ''Epioblasma biemarginata'', the angled riffleshell, was a species of freshwater mussel, an aquatic bivalve mollusk in the family Unionidae, the river mussels. It is now extinct. This species was endemic to the drainages of the Cumberland Ri ...

'' - Angled riffleshell **''

Epioblasma capsaeformis The oyster mussel (''Epioblasma capsaeformis'') is a rare species of freshwater mussel in the family Unionidae. This aquatic bivalve mollusk is native to the Cumberland and Tennessee River systems of Kentucky, Tennessee, Alabama, and Virginia ...

'' - Oyster mussel **†''

Epioblasma cincinnatiensis ''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 e ...

'' - Cincinnati Riffleshell **''

Epioblasma florentina ''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 ex ...

'' ***''

Epioblasma florentina aureola ''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 ex ...

'' - Golden riffleshell ***''

Epioblasma florentina curtisii ''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 ex ...

'' - Curtis pearlymussel ***†''

Epioblasma florentina florentina ''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 ex ...

'' - Yellow blossom ***''

Epioblasma florentina walkeri ''Epioblasma walkeri'', common name the tan riffleshell, is a species of freshwater mussel, an aquatic bivalve mollusk in the family Unionidae The Unionidae are a family of freshwater mussels, the largest in the order Unionida, the bivalve ...

'' - Tan riffleshell **†''

Epioblasma propinqua ''Epioblasma propinqua'', the Tennessee riffleshell or nearby pearly mussel, was a species of freshwater mussel in the family Unionidae. It was endemic to the United States, where it was found in the drainages of the Cumberland River, Ohio Rive ...

'' - Tennessee riffleshell **†''

Epioblasma sampsonii ''Epioblasma sampsonii'', the Wabash riffleshell or Sampson's naiad, was a species of freshwater mussel in the family Unionidae. It is now extinct. The species was endemic to the United States The United States of America (U.S.A. or US ...

'' - Wabash riffleshell **''

Epioblasma torulosa ''Epioblasma torulosa'', commonly called the tubercled blossom, is a species of freshwater mussel, a mollusk in the family Unionidae. It is native to eastern North America, where it is considered endangered in both Canada and the United States. ...

'' ***†''

Epioblasma torulosa gubernaculum ''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 e ...

'' - Green blossom ***''

Epioblasma torulosa rangiana The northern riffleshell (''Epioblasma torulosa rangiana''), is a subspecies of freshwater mussel, an aquatic animal, aquatic bivalve mollusk in the family Unionidae, the river mussels. This subspecies is endangered. This species was formerly f ...

'' - Northern riffleshell ***†'' Epioblasma torulosa torulosa'' - Tubercled blossom **†'' Epioblasma turgidula'' - Turgid riffle shell *Subgenus ''Truncillopsis'' **''

Epioblasma triquetra ''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 St ...

'' - Snuffbox

Conservation status

Golden riffleshell mussels ready for release

This entire genus is imperiled. In this genus, 15 species or subspecies are believed to be extinct. Of those remaining, all are federally protected species. The last to be listed as a federally endangered species was ''

'', which was listed in 2012. This group of freshwater mussels is threatened primarily by habitat alteration as are other freshwater mussels. Dams, erosion, and pollution appear to be the primarily threats. Some workers recognize additional species not currently on the official list of recognized species.

Gallery

Image:Epioblasma capsaeformis.jpg, ''

'' Image:Epioblasma triquetra.jpg, ''

'' Image:Epioblasma walkeri.jpg, '' Epioblasma walkeri''

References

{{Taxonbar, from=Q3015342 Bivalve genera Taxa named by Constantine Samuel Rafinesque Taxonomy articles created by Polbot