Endangered
Villosa fabalis
Villosa fabalis
Villosa fabalis is a bivalve in the family Unionidae (order Unionida), recorded as Endangered.
Appearance
The shell is shiny and green, yellowish-green, or brown, and has many wavy, dark green rays. The shell is thick and solid. The nacre is silvery-white or bluish and iridescent towards the posterior side.
The rayed bean is a small mussel that is rarely larger than 3.8 cm (1.5 in) in length.
It was first described as Unio fabalis by Isaac Lea in 1831, from a specimen from the Ohio River.
Range and habitat
It is native to the drainages of the Ohio River, the Tennessee River, and Lake Erie and Lake St. Currently, it is thought to occur in Michigan, Indiana, Ohio, Pennsylvania, New York, Kentucky, West Virginia, and Ontario. In Canada, it is only known from the Sydenham River, with a small population in the north Thames River.
There have been several reintroduction efforts in different areas.
Pins are Wikidata “endemic to” fields. Orange dots, when present, are GBIF occurrence tiles — survey bias included.
Breeding
Freshwater mussels bury in the bed and live for decades if the river still runs and the host fish still spawn.
In crisis
The main threats to the rayed bean are siltation of rivers, water pollution, and changes in river flow and physical barriers imposed by dams. Many populations are geographically isolated and have become even more so as dams were constructed. Some are below the effective population size needed to sustain the population and maintain genetic diversity.
Several localized threats have been identified for certain populations the rayed bean. Dreissenid mussels from Fanshawe Lake in Ontario represent a potentially devastating threat to the Thames River population.
Villosa fabalis 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 Villosa fabalis, Wikidata item Q3013948. 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.
