Utah Valvata Snail

Valvata utahensis

Description

The Utah valvata snail has a turbinate shell (i.e., it is about equally high as wide), with up to four whorls, and as high as 0.2 in (4.5 mm).

Behavior

The Utah valvata snail feeds on dead plant bio-mass and on algae such as diatoms.

Habitat

The Utah valvata snail lives in deep pools near rapids or in perennial waters associated with large spring complexes. It occurs in areas with swift current, and prefers well-oxygenated water and a bottom substrate of mud or mud-sand among beds of submerged aquatic plants. A common associate is the macrophytic alga, Chara.

Distribution

The Utah valvata snail once occurred rather widely in prehistoric lakes and rivers in parts of California, Idaho, Nevada, Utah, and Wyoming. In the mid-1990s, it only occurred in a few spring and riverine sites in the Snake River, in the Hagerman Valley and below the American Falls dam to Burley, and near Minidoka Dam.

Threats

The Utah valvata snail has suffered habitat destruction and degradation through impoundment and flow-control activities on its streams and rivers. These have resulted in physical modification of its habitat and deteriorated water quality in terms of temperature, oxygen concentration, and nutrients.

Conservation and Recovery

One of the sites of the Utah valvata snail is in the Thousand Springs Preserve, a private protected area owned and managed by the Nature Conservancy. A recovery plan has been prepared for the rare snail, within the larger recovery plan for the Snake River. Its recovery depends upon achieving improvements in habitat and water quality in the Snake River. This would allow viable, naturally reproducing colonies of the snail to persist, and new ones to establish. Specific conservation measures include protection of the remaining free-flowing habitats from hydro-development, prevention of further diversions of water from the Snake River, achieving natural flow conditions, improving water quality, and enhancing watershed conditions.

Contacts

U. S. Fish and Wildlife Service
Regional Office, Division of Endangered Species
Eastside Federal Complex
911 N. E. 11th Ave.
Portland, Oregon 97232-4181
(503) 231-6121
http://pacific.fws.gov/

U. S. Fish and Wildlife Service
Regional Office, Division of Endangered Species
P. O. Box 25486
Denver Federal Center
Denver, Colorado 80225
http://www.r6.fws.gov/

U. S. Fish and Wildlife Service, Snake River Basin
Office
1387 South Vinnell Way, Room 368
Boise, Idaho 83709-1657
Telephone: (208) 378-5243
Fax: (208) 378-5262

References

U. S. Fish and Wildlife Service. 1996. "Utah Valvata Snail (Valvata utahensis )." U. S. Fish and Wildlife Service, Snake River Basin Sub-Ecoregion. (http://www.fws.gov/r1srbo/Outreach/utahvsnl.html). Date Accessed: July 7, 2000.

U. S. Fish and Wildlife Service. 1995. "Snake River Aquatic Species Recovery Plan." Boise, Idaho.