SPECIES FACT SHEET
Species Common Name: Klamath Rams-horn
Species Scientific Name: Vorticifex klamathensis klamathensis (Baker,
1945)
Phylum: Mollusca
Class: Gastropoda
Order: Basommatophora
Family: Planorbidae
Type Locality: Head of Link River (outlet of Klamath Lake), Klamath
Falls, Klamath Co., OR (Frest and Johannes 1998).
OR/WA BLM and FS Region 6 Units where Suspected or
Documented:
Fremont-Winema National Forest (documented).
Technical Description:
Shell similar to that of V. effusa (Lea, 1856), but with larger, reddish
shell with few, rapidly expanding whorls, and a flat spire, barely visibly
in side view. Many specimens are decollate, i.e. the early whorls are
broken off. The aperture is circular and reflects the rounded periphery of
the body whorl.
Life History:
Semelparous – lives 1-2 years, breeds and dies. Population turn over is
probably greater than 90%.
Freshwater pulmontates generally reproduce by copulation and crossfertilization. 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 hatch as young snails, anatomically complete except for
the reproductive system (Hyman 1967).
Feed by scraping algae and diatoms from rock surfaces in stream. May
occasionally feed on other plant surfaces. Present all year, but not active
in winter. Individuals have no lungs or gills with respiration through the
mantle cavity.
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Range, Distribution (Current and Historic), and Abundance:
Formerly occurred in the Upper Klamath Lake drainage, including Upper
and Lower Klamath Lake and Tule Lake. Currently known from Upper
Klamath Lake, and in the Link River at 14 sites.
Potential habitats on the Klamath Falls Resource Area, Lakeview BLM,
have been surveyed on numerous occasions by Frest and Johannes
(1993, 1995, 1998, and 2000) and by PacifiCorp (2004) with no
individuals of this species found. Based on the results of these surveys,
the Resource Area does not consider this species to be suspected on their
unit.
Habitat Associations:
Found in spring-fed lakes and limnocrenes, as well as large streams with
spring influence, although not found in springs themselves. Very cold,
highly oxygenated water on stable (boulder-gravel) substrate, in areas
with some current velocity. Most sites have abundant large woody
debris.
Threats:
Eutrophication of lake habitats resulting in sedimentation and higher
water temperatures; and modification of stream and lake habitats
resulting from dredging and channelization for logging and irrigation.
Diversion of springs for agriculture, urbanization and domestic water
supplies has removed suitable habitat in some locations.
Conservation Considerations:
(1) Control eutrophication, siltation and pollution,
(2) Prevent loss of spring influence resulting from water diversions
and ground water removal.
Prepared by: Nancy Duncan, April 2008
Edited by: Rob Huff, March 2011
Attachments
(1) Range Map
(2) References
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Attachment 1: Range Map:
Attachment 2: References
Baker, F. C. 1945. The Molluscan Family Planorbidae. University of
Illinois Press, Urbana, Illinois, 530 pp.
Burch, J. B. 1982. Freshwater snails (mollusca: gastropoda) of North
America. Environmental Monitoring and Support Laboratory. U.S.
Environmental Protection Agency. Contract No. 68-03-1280. Cincinnati,
Ohio.
Frest, T. J., and E. J. Johannes. 1998. Freshwater Mollusks of the
Upper Klamath Lake Drainage, Oregon. USDI Bureau of Land
Management. Contract No. ORFO 092094. Portland, OR.
Hyman, L. L. 1967. The invertebrates. Vol VI. Mollusca I. McGrawHill, New York. 792 pp.
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