Endangered
Oyster mussel
Epioblasma capsaeformis
Oyster mussel is a bivalve in the family Unionidae (order Unionida) — Epioblasma capsaeformis, recorded as Endangered.
Appearance
The periostracum is sunshiny, yellowish green, with green rays over the entire shell. The nacre color is bluish-white to creamy. Host fish species for this mussel include the wounded darter (Etheostoma vulneratum), redline darter (E. Rufilineatum), bluebreast darter (Etheostoma camarum), dusky darter (Percina sciera), banded sculpin (Cottus carolinae), black sculpin (Cottus baileyi), and mottled sculpin (Cottus bairdi).
This mussel is elliptical or obovate in shape and reaches a maximum length of 70 mm.
Range and habitat
This aquatic bivalve mollusk is native to the Cumberland and Tennessee River systems of Kentucky, Tennessee, Alabama, and Virginia in the United States. This mussel was once widely distributed and common. It is now extirpated from the Cumberland River system and the main artery of the Tennessee River.
Pins are Wikidata “endemic to” fields. Orange dots, when present, are GBIF occurrence tiles — survey bias included.
Habits
This mussel is known as a long term brooder, or bradytictic, meaning it spawns in late summer or fall and releases its larvae in early spring.
In crisis
It has declined 80% from its historical abundance. It remains in the Nolichucky River of Tennessee and the Clinch River in Tennessee and Virginia. Specimens once classified as this species that remain in the Duck River in Tennessee have now been classified as a separate species, Epioblasma ahlstedti.
The main threat to this species is habitat alteration such as channelization and impoundments of waterways, increased silt, and pollution.
Oyster mussel is Endangered on this catalog because that is the IUCN category stored on Wikidata. Confirm the official criteria and any later count on iucnredlist.org.
Sources
Written for this catalog from the English Wikipedia article on Oyster mussel, Wikidata item Q308039. Family and order context is original field-guide writing about the group, not a copied assessment of this one species. Wikipedia text is CC BY-SA. Not an IUCN assessment. Counts, when quoted, can change — confirm them on the recovery programme and on iucnredlist.org.



