Poplar Oregonian (snail) (Cryptomastix populi)

Three Poplar Oregonian snail shells at different angles and lined up horizontally.
Photo by William Leonard

Poplar Oregonian snail shell specimens.

Category: Molluscs
State status: Candidate
Vulnerability to climate change (More details)

Low

If you see this species, please share your observation using the WDFW wildlife reporting form. Providing detailed information such as a photo and exact coordinates will improve the confidence and value of this observation to WDFW species conservation and management.

The Poplar Oregonian's population size is low and has a declining trend. These snails are in the family Polygyridae. Snails in the Cryptomastix genus are of conservation concern because they have specialized habitat requirements. Snails do not readily disperse and populations are isolated. They are vulnerable to alteration of their habitat. 

Description and Range

Physical description

The Cryptomastix species are medium to moderately large Pacific Northwest native species. The Poplar Oregonian is a medium-sized terrestrial snail, measuring about 0.67 inches (about 17 millimeters) wide by 0.35 inches (8.8 millimeters) high. The shell has a very low, convex-conic spire, with 5-1/2 whorls. A whorl is the part of the shell that is one 360-degree section of the spiral. The shell has fine ridges, and the shell opening is round, with a wide white lip. Live snails have a wine-red shell color and a dark blue-black body.   

Ecology and life history

The Poplar Oregonian is found in talus and brushy draws in canyons in moderately xeric, rather open and dry situations, in talus on steep, cool (generally north or east facing) lower slopes in major river corridors. Many dryland snail species (likely including the Poplar Oregonian) are specialized for such habitats, and they are unable to tolerate high levels of humidity and moisture. 

This species’ biology and ecology are poorly understood, with little or no information available on lifespan, oviposition behavior, eggs, or potential. 

Reproductive biology is likely similar to other species of Cryptomastix that inhabit arid environments. It is hermaphroditic, but self-fertilization is normally avoided; it exchanges gametes with other individuals when conditions are favorable. 

Poplar Oregonians may be partially herbivorous on green plants during certain seasons, while also feeding on microorganisms associated with decaying leaf litter, such as molds, yeasts and bacteria.

Like most land snails, this species is probably relatively sedentary and a poor disperser. 

Geographic range

The Poplar Oregonian is found along the Snake River in Whitman and Asotin Counties, Washington, in the northeast corner of Wallowa County in Oregon, and in Cottonwood Canyon, Nez Perce County, Idaho. It occurs in isolated colonies in comparatively intact portions of its historical range such as roadless areas in the lower Salmon River and northern Hells Canyon. Empty shells are common, but the abundance of living animals is unknown.

Climate vulnerability

Sensitivity to climate change

Low

There is limited information on the sensitivity of the Poplar Oregonian snail to climate change. There is very limited information on this species’ life history. Populations are found in moderately dry and cool, low-elevation talus habitats in river basins. This species appears to be well adapted to drier habitats than other terrestrial snails, and therefore may be less susceptible to changes in moisture levels.

Confidence: Low

Exposure to climate change

  • N/A

Conservation
This species is identified as a Species of Greatest Conservation Need (SGCN) under the State Wildlife Action Plan (SWAP). SGCN-classified species include both those with and without legal protection status under the Federal or State Endangered Species programs, as well as game species with low populations. The WDFW SWAP is part of a nationwide effort by all 50 states and five U.S. territories to develop conservation action plans for fish, wildlife and their natural habitats—identifying opportunities for species' recovery before they are imperiled and more limited.
This species is identified as a Priority Species under WDFW's Priority Habitat and Species Program. Priority species require protective measures for their survival due to their population status, sensitivity to habitat alteration, and/or recreational, commercial, or tribal importance. The PHS program is the agency's main means of sharing fish and wildlife information with local governments, landowners, and others who use it to protect priority habitats for land use planning.

Conservation Threats and Actions Needed

  • Resource information collection needs
    • Threat: Status assessment is insufficient
    • Action Needed: Improve status assessment
  • Fish and wildlife habitat loss or degradation
    • Threat: Mining of basalt talus
    • Action Needed: Management recommendations; technical assessment
  • Agriculture and aquaculture side effects
    • Threat: Livestock grazing practices that do not benefit species
    • Action Needed: Outreach, coordinate with landowners to incorporate management recommendations to benefit the species

See the Climate vulnerability section above for more information about the threats posed by climate change to this species.  

Resources

References

Applegarth, J. S. 1999. Management Recommendations for Cryptomastix hendersoni, the Columbia Oregonian (land snail) v.20, Section 2, in T. E. Burke, J.S. Applegarth, and T. R. Weasma. Management Recommendations for Survey and Manage Terrestrial Mollusks (v. 2). USFS and BLM.

Burke, T. E. 2013. Land Snails and Slugs of the Pacific Northwest. Oregon State University Press, Corvallis, OR. 344 pp.

Burke, T., J. Applegarth, T. Weasma, and N. Duncan. 1999. Management recommendations for Survey and Manage terrestrial mollusks, ver. 2.0. USDA Forest Service, USDI Bureau of Land Management. Available online at http://www.or.blm.gov/surveyandmanage/MR/TM23Species/m2000-003.htm

COSEWIC. 2013. COSEWIC assessment and status report on the Oregon Forestsnail Allogona townsendiana in Canada. Committee on the Status of Endangered Wildlife in Canada. Ottawa. xii + 87pp. (www.registrelep-sararegistry.gc.ca/default_e.cfm).

Duncan, N. 2009. Vespericola columbianus depressa. Species Fact Sheet. Interagency Special Status/Sensitive Species Program, Forest Service, Bureau of Land Management.

Edworthy, A., K. Steensma, H. Zandberg, and P. Lilley. 2012. Dispersal, home range size and habitat use of an endangered land snail, the Oregon Forestsnail (Allogona townsendiana). Canadian Journal of Zoology 90(7):875–884.

Foltz Jordan, S., S.H. Black. 2015. Conservation Assessment for Cryptomastix devia, Puget Oregonian. USDA 2028 Forest Service Region 6 and USDI Bureau of Land Management. Portland, OR. pp. 32.

Frest, T. J., and E. J. Johannes. 1995. Interior Columbia Basin Mollusk Species of Special Concern. Final Report, Deixis Consultants, Seattle. Prepared for Interior Columbia Basin Ecosystem Management Project, Walla Walla, WA 362 pp.

Sato, C. 2018. Conservation assessment of the Poplar Oregonian (Cryptomastix populi) Mollusca. Washington Department of Fish and Wildlife, Wildlife Diversity Division, Olympia, Washington. 2 pp.

Steensma, K. M. M., L. P. Lilley, and H. M. Zandberg. 2009. Life history and habitat requirements of the Oregon forestsnail, Allogona townsendiana (Mollusca, Gastropoda, Pulmonata, Polygyridae), in a British Columbia population. Invertebrate Biology 128:232–242.

USFWS. 2011. Endangered and Threatened Wildlife and Plants: 90-day finding on a petition to list 29 mollusk species as threatened or endangered with critical habitat: proposed rule. Federal Register 76 (No. 193, October 5, 2011): 61826-61853.