Shortface lanx (Fisherola nuttalli)

Category: Molluscs
Common names: Giant Columbia River limpet
State status: Candidate
Vulnerability to climate change (More details)

Moderate

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 shortface lanx is an uncommon aquatic snail in Washington; its population size has a declining trend. Currently in the state, large populations of this snail persist in the Okanogan River and the Hanford Reach of the Columbia River; small populations are found in the Methow and Grand Ronde rivers. The species requires clear, cold, well-oxygenated waters, and is threatened by pollution and siltation.

Description and Range

Physical description

Shortface lanx is a small pulmonate (lunged) snail in the family Lymnaeidae. It is also known as Giant Columbia River limpet because it has a low, flat conical shell, but it is not a limpet.  The shell may be between 0.3 to 0.5 inches long, 0.25 to 0.4 inches wide, 0.12 to 0.2 inches high; size of adults varies with stream size. The shells are described reddish or brown in color.

Ecology and life history

Shortface lanx are found in unpolluted, cold, well-oxygenated perennial streams and rivers, generally 100 to 325 feet wide, with a cobble-boulder substrate. Within such streams it is found primarily on diatom-covered rocks at the edges of rapids or immediately downstream from rapids in areas that have suitable substrate. These snails have not been found in areas with silt or mud substrates, extreme seasonal variations in water level, an abundance of aquatic plants or algae, bedrock substrate, or where dredging or mining occurs.

Shortface lanx feeds by scraping algae and diatoms from rock surfaces in streams. The species may occasionally feed on other plant surfaces.

Fisherola snails are hermaphrodites but do not appear to be self-fertilized, thus mating occurs between two individuals. Eggs are laid from spring to autumn in gelatinous capsules attached to plants, stones, or other objects. They lack a free-swimming larval stage, and hatchlings are morphologically similar to adults, except that they lack a functional reproductive system. Young snails appear to grow rapidly and require only a few months to reach full size.

Individual F. nuttalli probably live for only one year, as this species breeds once and dies afterwards (semelparous breeding).

Individuals are present year-round in the streams they inhabit, but they are inactive during the winter.

Geographic range

This species was historically present throughout much of the Columbia River drainage in Washington, Montana, Oregon, Idaho, and British Columbia, but most populations were extirpated due to habitat loss resulting from dams, impoundments, water removal, and pollution. This species is now presumed extirpated in Montana and possibly in British Columbia.

Currently in Washington, large populations of the species persist in the Okanogan River and the Hanford Reach of the Columbia River; small populations are found in the Methow and Grand Ronde rivers.

The species also occurs in the lower Deschutes River in Oregon, and the Snake River in Oregon and Idaho. In Idaho, it occurs in the Middle and Upper Snake River reaches from Elmore County, upstream to at least Bingham County. Populations also occur in the Salmon River and Hells Canyon of the Snake River including parts of Nez Perce and Idaho Counties. Additional small populations are found in Oregon in the Grande Ronde, John Day, and Imnaha Rivers, and the lower Columbia River near Bonneville Dam.

For maps of range-wide distribution and conservation status of this species, check out NatureServe Explorer and the International Union for Conservation of Nature’s Redlist.

Climate vulnerability

Sensitivity to climate change

Low-
Moderate

There is limited information on the sensitivity of this species to climate change. This species is found in cold, perennial, highly oxygenated rivers and streams, and may therefore be sensitive to changes in flow regimes and water temperatures that negatively impact dissolved oxygen levels and chemical and biological processes. This species occurs in low densities in isolated populations and therefore may be acutely vulnerable to diseases or other regimes causing mass mortality because they may not be able to quickly rebuild populations.

Confidence: Low

Exposure to climate change

Moderate-
High

  • Altered flow regimes
  • Reduced oxygen
  • Increased water temperatures
  • Increased disease outbreaks
Confidence: Low

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.

For aquatic snails, limiting factors may include hardness, acidity, dissolved oxygen, salinity, high temperature, and food availability as associated with depth. Snails are uncommon in habitats with surface acidity greater than pH 5. Dissolved oxygen limits diversity, so severely polluted waters (oxygen consumed by algae blooms) are often devoid of freshwater snails excepting pollution-tolerant species. Most species live in the shallows, (depths less than 10 feet) where food abundance is greatest. As a result, drastic water fluctuations (draw-downs) may cause declines in snail populations.

Conservation Threats and Actions Needed

  • Fish and wildlife habitat loss or degradation
    • Threat: Pollution and siltation.
    • Action Needed: Protect water quality.
  • Agriculture and aquaculture side effects
    • Threat: Pollution and siltation.
    • Action Needed: Develop management recommendations.

See the Climate vulnerability section for 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.

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. (https://www.canada.ca/en/environment-climate-change/services/species-risk-public-registry.html)

Duncan, N. 2009. Species Fact Sheet: Vespericola columbianus depressa. Interagency Special Status/Sensitive Species Program, Forest Service, Bureau of Land Management. (https://www.fs.fed.us/r6/sfpnw/issssp/documents/planning-docs/sfs-ig-vespericola-columbiana-depressa-2009-02.doc (DOC))

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. & C. Mazzacano. 2014. Species Fact Sheet: Fisherola nuttalli. U.S. Department of Agriculture, Forest Service, Interagency Special Status/Sensitive Species Program (ISSSSP). (https://www.fs.fed.us/r6/sfpnw/issssp/documents3/sfs-ig-fisherola-nuttalli-2014-11.doc (DOC))

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.

Liu, H-P., Marceau D. and R. Hershler.  2016.  Taxonomic identity of two amnicolid gastropods of conservation concern in lakes of the Pacific Northwest of the USA.  Journal of Molluscan Studies.  82:464-471.

Monthey, R. and N. Duncan 2005. Conservation assessment for Lyogyrus n.sp.2, Masked Duskysnail. USDA Forest Service Region 6, and USDI Bureau of Land Management, Oregon and Washington. (Originally issued in 1998 as management recommendations by R. Monthey; revised 2005 by N. Duncan). 10 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.

Washington Department of Natural Resources. 2005. Covered Species Technical Paper. Aquatic Resources Program Endangered Species Act Compliance Project. Prepared by Entrix and Battelle. Washington Department of Natural Resources, Olympia, WA.

Other resources