Pyrgulopsis owyheensis is a tiny, gill-breathing, operculate, aquatic snail endemic to thermal springs. The Owyhee hot springsnail is distinguished by its broad, low-spired, squat shell and large, discshaped, glandular ornament on its penis.
Pyrgulopsis fresti is associated with a very narrow community as it is a hot springs endemic and inhabits thermal springs with temperatures of 24 to 33°C. It lives on loose cobble and basalt rock faces in very shallow water of spring runs and seeps.
Limiting factors
The Owyhee hot springsnail is threatened by the destruction or alteration of its habitat. Disturbances to springs that negatively impact Pyrgulopsis species include livestock grazing (due to trampling of the snail and its habitat from livestock and pollution from their excrement), recreational activities (such as bathing) which may lead to pollution and accidental crushing of the snail, introduction of invasive species, and changes to the availability of underground freshwater storage.
Data gaps
Collect life history information. Obtain current population size and trend data. Assess distribution and determine range. Assess the effects of environmental changes on this species. Develop tools to assess the effects of water withdrawal on water levels and discharge.
Conservation actions
Monitor existing populations and survey suitable habitat for new populations. Restore and protect geothermal springs along the Owyhee River. Manage new and known sites and their associated watersheds to reduce the impacts of heavy grazing, water diversions, vehicle use, recreational use, and other practices that would adversely affect any aspect of this species’ life cycle. Maintain water quality, substrate conditions, and canopy cover at occupied sites.
Key reference or plan
Petition to Protect the Owyhee hot springsnail (Pyrgulopsis fresti) under the Endangered Species Act. 2024. The Center for Biological Diversity. 17 pp.
Hietala-Henschell, K.. and C. Fallon. 2018. Interagency Special Status/Sensitive Species Program (ISSSSP) Species Fact Sheet: Pyrgulopsis fresti. USDA Forest Service Region 6 and USDI Bureau of Land Management Oregon State Office. 14 pp.
