SPECIES FACT SHEET
Species Common Name: Pristine springsnail
Species Scientific Name: Pristinicola hemphilli (Pilsbry, 1907)
Phylum: Mollusca
Class: Gastropoda
Order: Neotaenioglossa
Family: Hydrobiidae
Technical Description:
According to Hershler et al. (1994), the narrowly-conic, almost pupiform shell is clear-white and
1.7-3.1 mm in length. There are 4.5-5.5 whorls that end in a blunt apex. The protoconch is
finely wrinkled, often eroded and is about 1.5 whorls. Teleoconch whorls have shallow sutures
and are flat to moderately convex and rarely have an abapical shoulder or subsutural angulation.
The sculpture of weak collabral growth lines on the teleoconch is often accompanied by
numerous faint spiral striae. Ovate-elongate aperture is rounded or expanded below and rounded
or slightly angled above. The fairly thick inner lip is complete and slightly reflected, adnate or
very slightly separated from the body whorl. The slightly thickened outer lip can be straight or
slightly curved, usually opisthocline, or sometimes orthocline. Tan-light brown periostracum is
often covered by thick dark deposits. Umbilicus is usually absent or slightly rimate. Ovate
operculum is red-brown, fairly thick and horny; the dorsal surface is unfrilled and nucleus
eccentric. The fairly large attachment scar is raised and callus. Inner edge of the attachment scar
margin is strongly thickened while a weaker scar runs along the outer edge. For a further
detailed description of the morphology of Pristinicola hemphilli, refer to Hershler et al. 1994.
Life History:
Duncan (2008) states this species of snail is semelparous (reproduce a single time before dying)
and males and females live 1-2 years. Pristinicola hemphilli is completely aquatic and breathe
using gills. Snails feed upon algae, yeast, bacteria and diatoms from rocks and woody surfaces,
although they have been known to feed upon other plant surfaces. Plant matter transported by
birds and mammals as well as mud passively moving downstream may help aid in downstream
dispersal.
Range, Distribution, and Abundance:
Duncan (2008) states current sites are dominated by small cold streams which are undisturbed.
Populations at many of the sites contain hundreds of individuals, although numbers vary
considerably from year to year due to environmental factors. Colonies are scattered through the
Colombia and Snake River basins into western Idaho. Pristinicola hemphilli can also be found
in interior Oregon in the Deschutes, Umatilla and John Day River basins. They are also known
to occur in the Rogue, Umpqua and Smith River basins in southern Oregon and Del Norte
County in northern California. Coastal drainages and undisturbed portions of the Willamette
River basin may also contain some populations of this snail.
Habitat Associations:
Frest and Johannes (1999) state habitats supporting this species tend to be small cold springs or
seeps which are in a pristine condition and contain coarse gravel/cobble substrate. Sometimes
snails are found in larger springs or areas of small streams which are affected by springs. Plants
commonly found in association with the species include Rorippa, Mimulus and bryophytes.
Sites tend to occur at low-medium elevation and are in semiarid sage scrub. Also, fairly dense
Douglas fir forests at low-medium elevation in the Cascades and Southern Oregon contain this
species of snail.
Threats:
Duncan (2008) states diversions and groundwater pumping for campground, hatchery stock and
domestic water supplies can induce hydrologic changes affecting flow of the small seeps and
springs which P. hemphelli prefer. Additional damage has also been caused by urbanization,
logging, road construction and maintenance, grazing, and flooding as a result of dam
construction. At some sites in Grant County, WA excessive algae growth and loss of local
populations has occurred due to nutrient-rich groundwater changing the water chemistry.
Conservation Considerations:
Duncan (2008) recommend that vegetative cover should be maintained, as well as water quality
and the current hydrologic regime at sites known to contain this species of snail. Close
monitoring and management of grazing should be enforced to assess the effects upon hydrologic
patterns and the aquatic habitat. Activities which lower the flow rate or raise the water
temperature such as diversions or pumping of groundwater should be restricted.
Conservation Status:
Pristinicola hemphilli is globally ranked G3- rare, threatened or uncommon throughout its range
(Oregon Natural Heritage Information Center 2007). In Oregon this species of snail is ranked
S2- imperiled because of rarity or due to other factors making it vulnerable to extinction or
extirpation.
Since this species of snail is normally associated with springs and seeps which are in pristine
condition, it is very vulnerable to any sort of activities which would disrupt its habitat. Colony
size also tends to be extremely variable from year to year, making it difficult to determine a
population trend.
ATTACHMENTS:
(1)
Map of known sites of Pristinicola hemphilli
(2)
Photo of Pristinicola hemphilli
(3)
Information sources
Preparer: Heather Andrews
Special acknowledgment for the draft Pristine springsnail (Pristinicola hemphilli) species fact sheet prepared
by Nancy Duncan in 2008, from which a large portion of the information in this document was derived.
Date Completed: 6/14/10
Reviewed and edited by Rob Huff, Conservation Planning Coordinator, FS/BLM and Robin Vora, Deschutes
and Ochoco National Forests, September 2010.
ATTACHMENT 1: Map of known sites of Pristinicola hemphilli
Sites recorded in GeoBOB, Oregon Natural Heritage Database and the regional mollusk voucher
database. Image from Duncan (2008).
ATTACHMENT 2: Photo of Pristinicola hemphilli
P. hemphilli snail shell. Image from Duncan (2008).
ATTACHMENT 3: Information Sources
Duncan, N. 2008. Pristine springsnail (Pristinicola hemphilli) species fact sheet.
http://web.or.blm.gov/Mollusks/images/Pristinicola%20hemphilli.pdf. Unpublished BLM
document. in Duncan, N. 2008. WELCOME TO THE MOLLUSK INFORMATION
EXCHANGE. Pacific Northwest Mollusks. http://web.or.blm.gov/ Mollusks/.
Frest, T.J. and E.J. Johannes. 1999. Mollusk survey of southwestern Oregon, with emphasis on
Rogue and Umpqua River drainages. Prepared for Oregon Natural Heritage Program. Seattle,
Washington.
Hershler, R., T.J. Frest, E.J. Johannes, P.A. Bowler and F.G. Thompson. 1994. Two New Genera
of Hydrobiid Snails (Prosobranchia: Rissooidea) from the Northwestern United States. The
Veliger 37(3): 221-243.
Oregon Natural Heritage Information Center. 2007. Rare, Threatened and Endangered Species of
Oregon. Oregon Natural Heritage Information Center Institute for Natural Resources. Oregon
State University, Portland, OR. Available Online
(http://oregonstate.edu/ornhic/publications.html). 100 pp.