SPECIES FACT SHEET

Scientific Name: Pyrgulopsis robusta (Walker, 1908)Common Name(s): Jackson Lake springsnail Phylum: MolluscaClass: GastropodaOrder: LittorinimorphaFamily: Hydrobiidae (Johnson et al. 2013; Hershler and Liu 2017)

Conservation Status:Global Status: G5 (last reviewed 23 September 2011)National Status (United States): N5 (23 September 2011)State Statuses: S2S3 (OR), SNR (WA)(NatureServe 2019)

Federal Status (United States): Not Listed; Pyrgulopsis idahoensis (now synonymized with P. robusta) was delisted in 2007, removing it from the FederalList of Endangered and Threatened Wildlife (Federal Register 2007) IUCN Red List: Least Concern (Cordeiro and Perez 2011)

Synonyms: Pomatiopsis robusta Walker, 1908, Jackson Lake springsnail; Pyrgulopsis hendersoni Pilsbry, 1933, the Harney Lake springsnail (Pyrgulopsis n. sp. 3, the Lake Abert springsnail and the XL Ranch springsnail, are also considered to represent populations of P. hendersoni [Frest and Johannes 1995]); Pyrgulopsis idahoensis Pilsbry, 1933, Idaho springsnail; Pyrgulopsis n. sp. “6”, “8”, “A” “Columbia Springsnail” (Frest and Johannes 1995; Hershler and Liu 2004b; Frest et al. 2008; Johannes 2019)

Taxonomic Notes:Pyrgulopsis robusta was originally described by Walker (1908) as Pomatiopsis robusta. Following several taxonomic revisions, Hershler and Thompson (1987) assigned this species to the Pyrgulopsis genus. Historically, distinctions between species within the genus have typically been made based on the arrangement and number of glands on the penes and other reproductive structures due to morphological similarities in the shells. More recent genetic studies have re-evaulated the taxonomic relationship between taxa in the genus, including P. robusta and three others in the Natricola

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Gregg and Taylor, 1965 subgenus (Hershler and Liu 2004b). Prior to the work of Hershler and Liu (2004b), both Pyrgulopsis hendersoni and Pyrgulopsis n. sp. “Columbia springsnail” were considered to be closely related to the Federally Endangered Pyrgulopsis idahoensis, the Idaho springsnail, and Pyrgulopsis robusta, which was considered endemic to Wyoming. Two other taxa, previously recorded in some unpublished conservation documents (e.g., Frest and Johannes 1995) as Pyrgulopsis n. sp. 3, the Lake Abert springsnail and the XL Ranch springsnail, are also considered to represent populations of P. hendersoni, the Harney Lake springsnail (Hershler and Liu 2004b).

Upon review of morphological characters and mitochondrial and nuclear DNA sequences, Hershler and Liu (2004b) determined that these four Natricola snails do not merit recognition as distinct species and should instead be treated as a single species—P. robusta; and as such, the Natricola Gregg and Taylor, 1965 subgenus is placed in synonymy with Pyrgulopsis Call & Pilsbry, 1886. Based upon this new classification, the USFWS made a final ruling that removes P. idahoensis from the Threatened and Endangered list (Federal Register 2007). In addition, because they have been synonymized with P. robusta, a petition to list the Jackson Lake springsnail, Harney Lake springsnail, and Columbia springsnail (Bowler et al. 2004) as separate species was ruled not warranted by the USFWS (Federal Register 2006).

Citing morphological, ecological, and behavioral differences among the recently synonymized taxa, some researchers have questioned the findings of Hershler and Liu’s 2004 work (Bowler 2003; Bowler et al. 2004). However, no further taxonomic studies have attempted to resolve these taxa. Given the present information, isolated populations of P. robusta, previously considered separate species, will be treated here as one species and referred to as: the “Oregon Closed Lakes Basin population” (formerly P. hendersoni—the Harney Lake springsnail), the “Columbia River population” (formerly P. n. sp. “Columbia springsnail”—in different unpublished reports, this taxon was referred to as P. n. sp. “6”, P. n. sp. “8” and P. n. sp. “A” [i.e., Frest and Johannes 1995; Hershler and Liu 2004b; Bowler et al. 2004; Johannes 2019]), the “northwestern Wyoming population” (formerly P. robusta—Jackson Lake springsnail), and the “Snake River population” (formerly P. idahoensis—the Idaho springsnail).

Technical Description: Adult: Pyrgulopsis is a genus of tiny, gill-breathing, operculate, aquatic snails with dextral shells in the family Hydrobiidae. This North American freshwater 2

genus is characterized as follows (Call and Pilsbry 1886; Hershler 1994): the minute shell (1-8 mm tall) is elongate-conic or turriform, imperforate, and unicarinate, with an acute apex and 4-5 whorls. The aperture is near circular to ovate and the peritreme is continuous. The operculum is thin to moderately thick, amber-red, corneous, with few to many spirals, and near central to highly eccentric nucleus (Call and Pilsbry 1886; Hershler 1998). The similarities in external shell morphology between taxa in this family makes identification to species based on shell characters problematic (Frest and Johannes [n.d.]). Because of this, the distinctions between species within the genus Pyrgulopsis have typically been made based on the number and arrangement of glands on the penis and other reproductive structures. DNA analysis is another tool used to separate species in this genus. The COI sequence and protein sequence are available for P. robusta (Ratnasingham and Herbert 2019; UniProt 2019).

The shell of P. robusta is large for the genus, approximately 4.6-7.5 mm high. The shell height/shell width is 1.48- 2.10 mm and the shell height/aperture height measures between 1.98-3.38 mm. The shell is usually ovate- to narrow-conic with 4.5-6.25 whorls, which are weakly to moderately convex (Hershler and Liu 2004b). Overall, the shell is clear to white with a tan periostracum, and narrowly umbilicate. The aperture is weakly angled above and ovate. The operculum is ovate and multispiral with an eccentric nucleus. Tentacles are pale with a darker patch distal to eyespots. The snout is light to dark gray-brown and the foot is pale-dark gray. The penial lobe and filament are similar in length with the dorsal proximal lobule well developed, usually overlapping the base of the filament. The terminal gland is elongate and transverse. The dorsal distal lobule is well developed, and usually has one or a series of small glands. The ventral lobule is usually well developed and bears a large gland (Hershler and Liu 2004b). For additional morphological details see Hershler and Liu (2004b). A key to the genus is available in Hershler and Liu (2017). 

Immature: Hydrobiidae eggs are typically laid in single capsules that are hemispherical and nongelatinous (Kabat and Hershler 1993). Juvenile P. robusta appear similar to adults but are very small (<1 mm in length; Lysne 2003).

See Attachment 4 for images of this species.

Life History:

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Adults: The Pyrgulopsis genus, commonly known as springsnails, is an extremely diverse group of gill-breathing (prosobranch) aquatic snails in the widespread Hydrobiidae family. Taxa in the genus typically have limited geographic ranges and often narrow environmental tolerances, inhabiting cold to hot springs, and a variety of other perennial freshwater habitats (Hershler 1994; Hershler and Sada 2002; Hershler and Liu 2009). After being synonymized with several isolated Pyrgulopsis populations in the West, P. robusta is now known to have a broad range of environmental tolerances and occurs in a wide variety of habitats (Hershler 2004; Lysne and Koetsier 2006a; 2006b; Lysne et al. 2007). This species is commonly found attached to hard substrates and emergent macrophytes where they feed on periphyton, consisting of algae, bacteria, fungi, and diatoms (Hershler 1998; Lysne et al. 2007).

Snails in this genus may require several months to become sexually mature, and most are semelparous, reproducing only once before death (Frest and Johannes 1995). Pyrgulopsis snails are short lived, with most surviving only one year (Frest and Johannes 1995); however, studies on western prosobranch taxa suggest that some may live longer than a year and overwinter (Dillon 2004). Estimates of survival for P. robusta were averaged at 382 days (Lysne 2003). An extended lifespan may allow for additional reproductive events, suggestive of an iteroparous reproductive strategy in overwintering P. robusta individuals (Lysne et al. 2007). Although many freshwater snails are hermaphroditic, most hydrobiid snails are dioecious and have separate male and female individuals. February to May appears to be the breeding season for many cold water snail species in the Pacific Northwest, and egg laying and hatching may occur between March and July (Frest and Johannes 1995). Hydrobiid snails of the Great Basin are typically oviparous and females likely deposit single eggs covered with a tough membrane or capsule on hard substrates (Hershler 1998). In the Snake River in Idaho, the emergence of young P. robusta snails was greatest in the summer and fall; however, information for snail emergence in Oregon and Washington is not known (Lysne et al. 2007).

Dispersal ability is unknown in this species, but is likely constrained by its gill-breathing requirements and intolerance for desiccation. Mechanisms for dispersal are suspected based on DNA evidence suggesting genetic similarity among isolated populations of P. robusta (Hershler and Liu 2004a; 2004b). Upstream migration may be a mechanism for active dispersal (Hershler and Liu 2004b); while passive dispersal may be mediated by attachment to 4

waterfowl (Liu et al. 2003). Recent introductions of P. robusta in the Columbia River basin are presumably human mediated (Johannes 2019).

Immature: Tiny juvenile P. robusta may emerge from eggs about one week to a month after oviposition (Brown et al. 2008).

Range, Distribution, and Abundance:Type Locality: The type locality for the originally described taxa (the northwestern Wyoming population), is Jackson Lake, Wyoming (Walker 1908). The Oregon Closed Lakes Basin population of P. robusta was originally found at a spring south of Burns in Harney County, OR (Pilsbry 1933). P. idahoensis was first described from Homedale, Owyhee County, Idaho (Pilsbry 1933).

Range: P. robusta is known to occur in four western states including Idaho, Oregon, Washington, and Wyoming (Lysne et al. 2007). Four isolated populations now synonymized with P. robusta include: the “Oregon Closed Lakes Basin population” (formerly P. hendersoni) in southern Oregon, the “Columbia River population” (formerly P. n. sp. 8 “Columbia springsnail”) in Oregon and Washington, the “northwestern Wyoming population” (P. robusta) from Jackson Lake in northwestern Wyoming, and the “Snake River population” (formerly P. idahoensis) in the Snake River Basin of Oregon and Idaho.

Distribution: In Oregon, P. robusta occurs in Harney, Lake, Malheur, and Wasco counties. In Washington it is known from Benton and Klickitat Counties. The Columbia River population was first documented in 1988 by the U.S. Fish and Wildlife Service within deep pool dredge samples from the Columbia River at Bonneville Dam. After this time, additional occurrences of the Columbia River population were documented from several sites in Oregon within the mainstem river, stretching from the lower Columbia east through the Gorge, and north to the Hanford Reach in Washington. Extensive snail surveys in this region before 2002 found no evidence of P. robusta (Neitzel and Frest 1993; Frest and Johannes 2004), and none have been found in historic museum collections or noted by collectors prior to this time (Frest et al. 2008). DNA studies support synonymy of Columbia River populations with those of populations in northwestern Wyoming, indicating these populations are the closest congeners, not geographically closer populations in southeastern Oregon (Hershler and Liu 2004a; 2004b). However, natural (e.g., falls) and built (e.g., dams) barriers presumably prohibit natural dispersal and genetic exchange between these populations (Hershler and Liu 5

2004b). Therefore, occurrences within the Columbia River are thought to result from recent introductions of this snail, rather than natural occurrences (see Johannes 2019). Other isolated populations in Oregon exist at spring sites in the Lake Abert area of Lake County in the Oregon Closed Lakes Basin as well as the South Fork Malheur River in Harney and Lake Counties (Oregon Closed Lakes Basin population), and in the Snake River within the Snake River drainage (near the Oregon-Idaho border) in Malheur County (Snake River population) (Frest and Johannes 1995; Hershler 1998; Hershler and Liu 2004a; 2004b).

BLM/Forest Service Land: Documented: Documented occurrences are known from BLM land in Oregon within the Vale District.

Suspected: In Oregon, this species is suspected to occur in the Lakeview, Burns, and Prineville Districts on BLM land, and on Forest Service land in the Columbia River Gorge National Scenic Area due to the proximity of nearby suitable habitat.

Abundance: Abundance estimates and population numbers for this species are not known. However, snails in the Pyrgulopsis genus likely make up a significant component of the benthic epifauna in the West, with densities of over 1,000 snails/m2 (Mladenka and Minshall 2001).

Habitat Associations:Many springsnails are endemic to a single spring, spring complexes, or local drainages, and are often associated with spring sources or headsprings, which provide stable temperatures, water chemistry, and flows (Hershler 1998; Hershler and Sada 2002; Brown and Lydeard 2010). Throughout its range, Pyrgulopsis robusta occurs in a wide range of habitats from pristine springs to large rivers, reservoirs, and lakes (Hershler and Liu 2004a; 2004b; Stephenson et al. 2004; Sada 2006; Lysne et al. 2007). Although habitats vary, all populations of this species are dependent on perennial freshwaters (Frest and Johannes 1995; Hershler and Liu 2004b). P. robusta has been collected from aquatic habitats with a wide range of temperatures (from 4°C-24°C in the Snake River) to those with narrow annual temperature ranges (14°C to 24°C in geothermal spring habitat in Wyoming; reviewed in Lysne et al. 2007). Some of the Columbia River populations occur in nearshore habitat with slow moving riffles, and others have been documented from relatively deep, cool water with constant flows (Frest and Johannes 1995; Frest et al. 6

2008). The Oregon Closed Lakes Basin population inhabits thermally stable small to large springs and spring pools often with dense macrophytes (commonly nonnative watercress [Rorippa spp.]) and moderate flows (Frest and Johannes 1995). This species is found on a wide range of substrates, including coarse sand, pebbles, and cobbles, as well as on coarse woody debris and emergent macrophytes (including Eleocharis sp., Rorippa sp., and Scirpus sp.; reviewed in Lysne et al. 2007). Substrate at spring habitats may consist of coarse sand and basalt cobbles (Frest and Johannes 1995). In rivers, P. robusta is found on pebble, gravel, and cobble-sized substrates. P. robusta has been documented feeding on algal and microbial films on the surfaces of benthic substrates (Frest and Johannes 1995; Lysne et al. 2007). As grazers which are often locally abundant, this species and others in the genus likely play an important role in ecosystem function as primary consumers (Hershler et al. 2014). P. robusta co-occurs with several other gastropods including FIuminicola sp., Lymnaea sp., Physa sp., Fossaria sp., Gyrartlus parvus, Physella gyrina, Pseudosuccinea colurnella, and Vorticifex effusa, as well as bivalve taxa, including Sphaerium sp., Pisidium variabile, Margaritifera falcata; however, it is typically not known to occur with other Pyrgulopsis taxa (Frest and Johannes 1995; Hershler and Sada 2002; Lysne et al. 2007).

Threats:As a result of limited dispersal abilities, endemism, and high vulnerability to habitat loss and degradation, freshwater gastropods have among the highest extinction rates of any taxa group relative to their background extinction rate (Johnson et al. 2013). Many taxa in the Pyrgulopsis genus are groundwater-dependent and sensitive to modification of the aquatic environments they inhabit (Frest and Johannes 1995; Hershler et al. 2014). Owing to their narrow habitat needs and geographic ranges, many springsnails are at high risk of extirpation and extinction. In spring habitat, P. robusta depends on stable water chemistry and flows characteristic of spring sources, therefore changes to groundwater levels and source flows can impact populations. Activities that lower the water table and dry out habitat, such as water diversion for domestic, industrial or stock use, also adversely affect this snail. In fact, groundwater extraction, diversion, and depletion have been linked to the loss of Pyrgulopsis species, including the extinction of P. brandi in Mexico (Hershler 1994) and the extirpation of several others in the West from aquifer drawdown (Myler et al. 2007; USFWS 2013). These snails are also sensitive to pollution, siltation, and hypoxia. Spring sites where Pyrgulopsis taxa are known to occur have been most heavily damaged or even destroyed by the 7

associated impacts from livestock grazing (Frest and Johannes 1995). In rivers, impoundments, agricultural inputs, and siltation threaten P. robusta populations (Frest and Johannes 1995; Frest et al. 2008). Overall, the degradation of water quality and quantity, substrate conditions, and riparian habitat will likely have adverse effects on this species and its life cycle.

Competition from invasive snails also threatens this species (Riley et al. 2008). The exotic New Zealand mudsnail (Potamopyrgus antipodarum) has been documented in the range of P. robusta and is abundant in the Snake River Basin and Columbia River Basin (Frest and Johannes 2003; Hardy et al. 2004; Lysne et al. 2007; Frest et al. 2008). In areas with degraded water quality, this introduced snail can reach high densities, and it likely competes for food and other habitat resources with endemic snails (Riley et al. 2008). These snails and their habitats are also impacted by introductions of nonnative fishes, many of which were introduced for sport and as biological control agents, and are now widespread (Sada and Vinyard 2002). Other nonnative introductions include mollusks (i.e., Melanoides tuberculata) and crustaceans (Procambarus sp.), the former of which may be responsible for springsnail declines and other mollusks in the Great Basin (Hershler and Sada 1987).

Conservation Considerations:Research: While considerable research focus has been placed on the life history of this taxon (reviewed by Lysne et al. 2007) compared to others in the genus, there is still much to be learned about environmental tolerances of Pyrgulopsis taxa, including P. robusta. This includes specifics on its physiological tolerances, habitat usage, dispersal ability, as well as its role in the food web and nutrient cycling. Questions regarding mechanisms of dispersal still exist for this species related to the occurrence of geographically isolated populations. More research is needed to further understand the implications of polyploidy (the state of a cell or organism having more than two paired sets of chromosomes) in this species and whether this trait can explain its wide-ranging environmental tolerances. This research may aid in a better understanding of the factors that constrain some springsnail populations to specific habitat types (Hershler et al. 2014; Liu and Hershler 2014). Research at known sites could include understanding the extent of specific threats to this species and its habitat (e.g., invasive snails and plants, grazing, impoundments, and groundwater extraction).

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Inventory: Quantitative sampling is important to determine the population status of this species and density estimates in its habitat. Additional surveys can occur in similar habitats in a variety of freshwater habitats, including springs, lakes, and slow flowing river habitat. Surveys for this species can also aid in the detection and extent of invasive Potamopyrgus antipodarum populations.

Management: Manage new and known sites and their associated watersheds to reduce any impacts of grazing, water diversions, recreation, and other practices that may directly impact habitat or adversely affect water quality. Where grazing threatens spring systems, exclosures can be constructed to keep livestock out of sensitive areas. Because snails in the genus are closely associated with their perennial aquatic habitats, protection of these habitats, including maintenance of water quality and quantity, substrate conditions, and riparian areas would likely benefit and help maintain this species (Hershler 1998). Where impoundments occur near spring habitats, conservation measures can include removal of structures that impede or limit flows, followed by restoration of altered habitat.

Version 2: Prepared by: Michele Blackburn The Xerces Society for Invertebrate ConservationDate: 20 December 2019

Reviewed by: Candace FallonThe Xerces Society for Invertebrate ConservationDate: 20 December 2019

Version 1: Prepared by: Heather AndrewsDate: April 2011

Reviewed by: Rob HuffFS/BLM Conservation Planning CoordinatorDate: June 2011

Recommended citation:Blackburn, M., H. Andrews, and R. Huff. 2019. Interagency Special Status/Sensitive Species Program (ISSSSP) Species Fact Sheet: Pyrgulopsis robusta. USDA Forest Service Region 6 and USDI Bureau of Land Management 9

Oregon State Office. 20 pp. Available at: https://www.fs.fed.us/r6/sfpnw/issssp/species-index/fauna-invertebrates.shtml.

ATTACHMENTS:(1)References (2)List of pertinent or knowledgeable contacts (3)Map of known records in Oregon and Washington(4)Photographs and/or illustrations of this species(5)Survey protocol, including specifics for this species

ATTACHMENT 1: References Bowler, P. 2003. Comments upon the report by Hershler and Liu on the “Taxonomic Status of the Idaho Springsnail (Pyrgulopsis idahoensis).” Letter submitted June 16, 2003 to Mr. Stephen Duke, Program Manager for Endangered Species and Private Lands, United States Department of the Interior, Fish and Wildlife Service, Snake River Fish and Wildlife Office, 1387 South Vinnell Way, Room 368, Boise, Idaho 83709.

Bowler, P.A., Biodiversity Conservation Alliance, Center for Biological Diversity, Center for Native Ecosystems, Western Watersheds Project, and the Xerces Society for Invertebrate Conservation. 2004. Petition to list the Jackson Lake springsnail (Pyrgulopsis robusta), Harney Lake springsnail (Pyrgulopsis hendersoni), and Columbia springsnail (Pyrgulopsis new species 6) as Threatened or Endangered. Report submitted to the United States Secretary of the Interior, Washington, D.C., July 2004. 59 pp.

Brown, K. M., B. Lang. and K. E. Perez. 2008. The conservation ecology of North American pleurocerid and hydrobiid gastropods. Journal of the North American Benthological Society 27(2): 484-495.

Brown, K. M. and C. Lydeard. 2010. Mollusca: Gastropoda. In: Ecology and classification of North American freshwater invertebrates. Third Edition. Academic Press. San Diego, CA. 277-306 pp.

Call, R.E. and H.A. Pilsbry. 1886. On Pyrgulopsis, a new genus of rissoid mollusk, with description of two new forms. Proceeding Davenport Academy of Natural Sciences. 10:9-14.

Cordeiro, J. and K. Perez. 2011. Pyrgulopsis robusta. The IUCN Red List of Threatened Species 2011: e.T18984A8773910. Available at:

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http://dx.doi.org/10.2305/IUCN.UK.2011-2.RLTS.T18984A8773910.en. [Accessed 3 December 2019].

Dillon, R.T. 2004. The Ecology of Freshwater Molluscs. Cambridge University Press, Cambridge, UK. 523 pp.

Federal Register. 2006. 12-Month Finding on a Petition To List the Jackson Lake Springsnail, Harney Lake Springsnail, and Columbia Springsnail, 71: 188, September 28, 2006.

Federal Register. 2007. Final Rule to Remove the Idaho Springsnail (Pyrgulopsis idahoensis) from the list of Endangered and Threatened Wildlife, 72: 150, August 6, 2007.

Frest, T.J. and E.J. Johannes. 1995. Interior Columbia Basin mollusk species of special concern. Final report: Interior Columbia Basin Ecosystem Management Project, Walla Walla, WA. Contract #43-0E00-4-9112. 274 pp. plus appendices.

Frest, T.J. and E.J. Johannes. [n.d.]. Northwestern U.S. sensitive nonmarine mollusks. Unpublished document. Available from E.J. Johannes.

Frest, T.J. and E.J. Johannes. 2003. Progress Report, Owyhee Mollusk Inventorty. Vale District BLM, Vale, OR.

Frest, T.J. and E.J. Johannes. 2004. Some freshwater mollusks of the Lower Columbia River, Oregon and Washington. In: Lower Columbia River Aquatic Nonindigenous Species Survey 2001-2004. Final Technical Report: Appendices (Sytsma M.D., Cordell, J.R., Chapman, J.W. & Draheim, R.C.). Prepared for the U.S. Coast Guard and the U.S. Fish & Wildlife Service. Center for Lakes and Reservoirs, Portland State University, Portland, Oregon. p. 69-88.

Frest, T.J., E.J. Johannes, and B.L. Tiller. 2008. Mollusk observations along the Hanford Reach of the Columbia River: 100 and 300 areas river corridor baseline risk assessment. Appendix F. Mollusk observations for the 100/300 area. In: Inter-Areas Component of the River Corridor Baseline Risk Assessment Sampling Summary (Queen, J.M.). Washington Closure Hanford, LLC, Richland, Washington. p. Fi-ii, F1-40.

Gregg, W.O. and D.W. Taylor. 1965. Fontelicella (Prosobranchia: Hydrobiidae), a new genus of West American freshwater snails. Malacologia 3:103-110.

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Hardy, M.A., T.R. Maret, and D.L. George. 2004 Reconnaissance of chemical and biological quality in the Owyhee River from the Oregon State line to the Owyhee Reservoir, Oregon 2001-02: US Geological Survey Water-Resources Investigations Report 03-4327. 48 pp.

Hershler, R. 1994. A review of the North American freshwater snail genus Pyrgulopsis (Hydrobiidae). Smithsonian Contributions to Zoology 554: 1-115.

Hershler, R. 1998. A systematic review of the hydrobiid snails (Gastropoda: Rissooidea) of the Great Basin, western United States. Part I. Genus Pyrgulopsis. Veliger 41: 1-132.

Hershler, R. and H.-P. Liu. 2004a. A molecular phylogeny of aquatic gastropods provides a new perspective on biogeographic history of the Snake River region: Molecular Phylogenetics and Evolution 32: 927-937.

Hershler, R. and H.-P. Liu. 2004b. Taxonomic reappraisal of species assisgned to the North American freshwater gastropod subgenus Natricola (Rissooidea: Hydrobiidae). The Veliger 47(1): 66-81.

Hershler, R and H.-P. Liu. 2009. New species and records of Pyrgulopsis (Gastropoda: Hydrobiidae) from the Snake River basin, southeastern Oregon: further delineation of a highly imperiled fauna. Zootaxa: 1-22.

Hershler, R. and H.-P. Liu. 2017. Annotated checklist of freshwater truncatelloidean gastropods of the western United States, with an illustrated key to the genera. Technical Note 449. U.S. Department of the Interior, Bureau of Land Management, National Operations Center, Denver, CO.

Hershler, R., H.-P. Liu, and J. Howard. 2014. Springsnails: a new conservation focus in Western North America. BioScience. 64(8):693-700.

Hershler R. and D.W. Sada. 2002. Biogeography of Great Basin aquatic snails of the genus Pyrgulopsis. In: Hershler, R., Madsen, D.B., Currey, D.R. (eds) Great Basin aquatic systems history. Smithson Contributions to Earth Science 33: pp 255–276.

Hershler, R. and F.G. Thompson. 1987. North American Hydrobiidae (Gastropoda: Rissoacea): redescription and systematic relationship to Tryonia stimpson, 1865 and Pyrgulopsis Call & Pilsbry 1886. Nautilus 101: 25-32.

Johannes, E.J. 2019. Pyrgulopsis robusta (Walker, 1908) in the Columbia River: an introduction. Tentacle 27:10-13.

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Johnson, P.D., A.E. Bogan, K.M., Brown, N.M. Burkhead, J.R. Cordeiro, J.T. Garner, P.D. Hartfield, D.A.W. Lepitzki, G.L. Mackie, E. Pip, T.A. Tarpley, J.S. Tiemann, N.V. Whelan, and E.E. Strong. 2013. Conservation Status of Freshwater Gastropods of Canada and the United States. Fisheries. 38(6):247-282.

Kabat, A.R. and R. Hershler. 1993. The Prosobranch snail family Hydrobiidae (Gastropoda: Rissooidea): Review of classification and supraspecific taxa. Smithsonian Institution Press, Washington, D.C. Number 547.

Liu, H-P. and R. Hershler. 2014. Microsatellite primers for a western North American springsnail (Pyrgulopsis robusta): Evidence for polyploidy and cross-amplification in P. bruneauensis. Journal of Molluscan Studies 80: 107–110.

Liu, H-P., R. Hershler, and K. Clift. 2003. Mitochondrial DNA sequences reveal extensive cryptic diversity within a western American springsnail. Molecular Ecology. 12: 2771-2782.

Lysne, S.J. 2003. The life history and ecology of two endangered Snake River gastropods: Utah valvata (Valvata utahensis; Call) and Idaho springsnail (Pyrgulopsis idahoensis: Pilsbry). M.S. Thesis, Boise State University, Boise, Idaho. 103 pp.

Lysne, S. and P. Koetsier. 2006a. Experimental studies on habitat preference and tolerances of three species of snails from the Snake River of southern Idaho, U.S.A. American Malacological Bulletin 21: 77-85.

Lysne, S. and P. Koetsier. 2006b. Growth rate and thermal tolerance of two endangered Snake River snails. Western North American Naturalist 66(2): 230-239.

Lysne, S.J., L.A. Riley, W.H. Clark and O.J. Smith. 2007. The life history, ecology, and distribution of the Jackson Lake springsnail (Pyrgulopsis robusta Walker 1908). Journal of Freshwater Ecology 22: 647-653.

Mladenka G.C., G.W. Minshall. 2001. Variation in the life history and abundance of three populations of Bruneau hot springsnails (Pyrgulopsis bruneauensis). Western North American Naturalist 61: 204–212.

Myler C.D., G.C. Mladenka, and G.W. Minshall. 2007. Trend analysis shows decline of an endangered thermophilic springsnail (Pyrgulopsis bruneauensis) in southwestern Idaho. Western North American Naturalist 67: 199–205.

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NatureServe. 2019. “Pyrgulopsis robusta” NatureServe Explorer: An online encyclopedia of life [web application]. Version 7.1. NatureServe, Arlington, Virginia. Available at: http://explorer.natureserve.org.

Neitzel, D.R. and T.J. Frest. 1993. Survey of Columbia River Basin streams for Columbia Pebblesnail Fluminicola columbiana and Shortface Lanx Fisherola nuttalli. Pacific Northwest Laboratory, Richland, Washington. ix + 29 p., appendices.

Pilsbry, H. A. 1933. Amnicolidae from Wyoming and Oregon. The Nautilus 47:9-12.

Ratnasingham, S. and Hebert, P.D.N. 2019. BOLD: The Barcode of Life Data System. “Pyrgulopsis robusta”. Available at: www.barcodinglife.org. [Accessed 21 November 2019].

Riley, L.A., Dybdah,l M.F., Hall, R.O. 2008. Invasive species impact: Asymmetric interactions between invasive and endemic freshwater snails. Journal of the North American Benthological Society 27: 509–520.

Sada, D.W. 2006. Harney Lake springsnail (family Hydrobiidae: Pyrgulopsis robusta sensu Pyrgulopsis 'hendersoni ') surveys in 2006. Technical report submitted to: U.S. Fish and Wildlife Service, Boise, Idaho. 46 pages.

Sada, D.W. and G.L. Vinyard. 2002. Anthropogenic changes in biogeography of Great Basin aquatic biota. Pages 277-293 in R. Hershler, D.B. Madsen, and D.R. Currey (eds.). Great Basin Aquatic Systems History. Smithsonian Contributions to the Earth Sciences. Number 33. 405 pp.

Stephenson, M.A., B.M. Bean, A.J. Foster, and W.H. Clark. 2004. Snake River Aquatic Macroinvertebrate and ESA Snail Survey. Idaho Power Company Technical report submitted to: U.S. Fish and Wildlife Service, Boise, Idaho in fulfillment of Section 10 permit #799558-4 requirements. 78 pp.

UniProt. 2019. “Pyrgulopsis robusta” UniProtKB database. [online database] Available at: https://www.uniprot.org/. [Accessed 3 December 2019].

[USFWS] 2013. United States Fish and Wildlife Service. Endangered and threatened wildlife and plants; determination of endangered species status for six west Texas aquatic invertebrates. Federal Register 78: 41228–41258.

Walker, B. 1908. Pomatiopsis robusta n. sp. The Nautilus. 21: 97.

Map references:

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Frest, T.J., E.J. Johannes, and B.L. Tiller. 2008. Mollusk observations along the Hanford Reach of the Columbia River: 100 and 300 areas river corridor baseline risk assessment. Appendix F. Mollusk observations for the 100/300 area. In: Inter-Areas Component of the River Corridor Baseline Risk Assessment Sampling Summary (Queen, J.M.). Washington Closure Hanford, LLC, Richland, Washington. p. Fi-ii, F1-40.

[GBIF] 2019. Global Biodiversity Information Facility. [online database]. Available at: https://doi.org/10.15468/dl.zojaiz [Accessed 4 December 2019].

[NMNH] 2019. National Museum of Natural History. Invertebrate Zoology Collections. Available at: https://collections.nmnh.si.edu/.

[ORBIC] 2018. Oregon Biodiversity and Information Center. GIS export provided to Candace Fallon, the Xerces Society, by Lindsey Wise, Biodiversity Data Manager, October 2018.

ATTACHMENT 2: List of pertinent, knowledgeable contactsEd Johannes, Deixis Consultants, Seattle-Tacoma, WA

Robert Hershler, Research Zoologist Emeritus, Smithsonian National Museum of Natural History, Washington DC.

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ATTACHMENT 3: Map of known Pyrgulopsis robusta records in Oregon and Washington.

Known records of Pyrgulopsis robusta in Oregon and Washington, relative to Forest Service and BLM land.

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ATTACHMENT 4: Images of Pyrgulopsis robusta.

Figure 1: Images of Pyrgulopsis robusta (d, shell; e-f, opercula; scale bars = 0.67 mm, 0.6 mm). Images extracted from Hershler (1994). Used with permission. Taxonomic group: Aquatic Gastropoda

How: Please refer to the following documents for detailed mollusk survey methodology:

1. General collection and monitoring methods for aquatic mollusks:

See documents under the heading “Invertebrates – Mollusks” on the Interagency Sensitive and Special Status Species web page: https://www.fs.fed.us/r6/sfpnw/issssp/inventories/identification.shtml

2. Standard survey methodology that can be used by field personnel to determine presence/absence of aquatic mollusk species in a given waterbody, and to document species locations and habitats in a consistent format:

Duncan, N. 2008. Survey Protocol for Aquatic Mollusk Species: Preliminary Inventory and Presence/Absence Sampling. Version 3.1. Portland, OR. Interagency Special Status/Sensitive Species Program. U.S. Department of Interior, Bureau of Land Management,

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Oregon/Washington and U.S. Department of Agriculture, Forest Service, Region 6. 52 pp. Available at: https://www.fs.fed.us/r6/sfpnw/issssp/species-index/fauna-invertebrates.shtml

Inventory and Monitoring protocol page, with NRIS/GeoBOB field forms. Available at: http://www.fs.fed.us/r6/sfpnw/issssp/species-index/fauna-invertebrates.shtml

ID services page, with current versions of field tags. Available at: http://www.fs.fed.us/r6/sfpnw/issssp/inventories/identification.shtml

Species-specific survey details:Pyrgulopsis robusta

How to survey: Aquatic snails may occur in a variety of habitat types, including springs, rivers and streams, and lakes and ponds. Seek out key habitat features known to be utilized by the target species (e.g., small-medium cold to thermal springs, spring influenced creeks, lakes, and medium to large rivers and reservoirs). Record geographic coordinates and key habitat features for each site surveyed. Standardized abundance estimates for this species at new and known sites would assist future conservation efforts, since population size is important in evaluating the stability of a species at a given locality.

A variety of methods may be used to sample for aquatic snails, including hand and dip-net collection, kick-net collection, and the use of surber samplers, grab samples, dredges, and wire-basket benthos samplers. Duncan (2008) outlines methods appropriate for typical aquatic habitats. Sample procedures should limit impacts to sensitive habitats, particularly springs and streambeds. Surveyors should avoid use of chemicals such as bug repellant or sunblock, which may wash off into the water. Surveyors should also take steps to disinfect gear prior to sampling and reduce risk of transferring invasive species among sampling sites (Duncan 2008). More information on invasive species and prevention strategies can be found at: http://www.fs.usda.gov/detail/r6/forest-grasslandhealth/invasivespecies/?cid=stelprdb5302184. Because Pyrgulopsis robusta populations occur in watersheds where the New Zealand mudsnail has been found, new occurrences of this invasive species can be documented at: https://www.invasivesnet.org/.

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Where: Surveys for P. robusta can occur in small-medium cold to thermal springs, spring influenced creeks, or medium to large-sized rivers and reservoirs. While out in the landscape, permanent springs in the arid West can be identified from a distance by locating green vegetation bordering the spring run and source, from geographic features such as hillsides, valleys, or gulches (Johannes 2016). Additionally, USGS 7.5’ topographic maps of potential survey areas can be used to narrow searches and identify larger mapped springs (Johannes 2016). Surveys could target spring sites with floating or emergent aquatic plants; this species has been found associated with Eleocharis, Rorippa, and Scirpus (Frest and Johannes 1995; reviewed in Lysne et al. 2007). At spring sites, surveyors could search on rocks and within and among emergent vegetation. In river habitats, this species is likely to occur on rocky substrate, including basalt pebble-cobble, in both nearshore, shallow riffle habitat and deep pools with constant flows (Frest and Johannes 1995; Frest et al. 2008). The more recent occurrence in the Columbia River, and the extension of this species’ range further upstream in the river’s mainstem suggests that the species may have a wider distribution in Oregon and Washington than is currently documented. Ongoing monitoring of known sites is recommended to determine population trends and potential and current threats. Re-evaluation of this species’ status at these sites is critical to identifying both its current distribution and its conservation needs. Future surveys could occur in spring-influenced habitat as well as lakes and rivers in the Oregon Closed Lakes Basin and the Columbia River Basin in Oregon and Washington.

When: In Oregon and Washington, P. robusta has been collected throughout the entire year. Sampling in springs can be conducted any time of year, but for semelparous (i.e., lay eggs once at maturity and die) snails like Pyrgulopsis species, surveys should be avoided during periods of population turnover (Duncan 2008). When most of the population is dying off or the majority of the individuals present are immature, it may be difficult to collect enough specimens or mature individuals for identification. This time period is not well known for all species, but as a general rule, it is recommended to avoid sampling in the spring (Duncan 2008). The breeding and egg laying season are also poorly defined for most Pyrgulopsis species, but may occur February to July. Surveys outside of this period are recommended to avoid impacts to breeding populations. Surveys in flowing waters should be conducted after water levels and flows have decreased and survey conditions are safe. Surveys in lakes or other lentic habitats should not occur during the

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coldest months to improve detection of bottom-dwelling species. These and other recommendations are outlined further in Duncan (2008).

References (Survey Protocol only):Duncan, N. 2008. Survey Protocol for Aquatic Mollusk Species: Preliminary Inventory and Presence/Absence Sampling. Version 3.1. Portland, OR. Interagency Special Status/Sensitive Species Program. U.S. Department of Interior, Bureau of Land Management, Oregon/Washington and U.S. Department of Agriculture, Forest Service, Region 6. 52 pp. [Available at: http://www.fs.fed.us/r6/sfpnw/issssp/species-index/fauna-invertebrates.shtml].

Frest, T.J. and E.J. Johannes. 1995. Interior Columbia Basin mollusk species of special concern. Final report: Interior Columbia Basin Ecosystem Management Project, Walla Walla, WA. Contract #43-0E00-4-9112. 274 pp. plus appendices.

Frest, T.J., E.J. Johannes, and B.L. Tiller. 2008. Mollusk observations along the Hanford Reach of the Columbia River: 100 and 300 areas river corridor baseline risk assessment. Appendix F. Mollusk observations for the 100/300 area. In: Inter-Areas Component of the River Corridor Baseline Risk Assessment Sampling Summary (Queen, J.M.). Washington Closure Hanford, LLC, Richland, Washington. p. Fi-ii, F1-40.

Johannes, E.J. 2016. Springs and the minute snail that inhabit them in the Puget Sound region: Searching for the concealed. Deixis Consultants, SeaTac, Washington. 44(3): 34-37.

Lysne, S.J., L.A. Riley, W.H. Clark and O.J. Smith. 2007. The life history, ecology, and distribution of the Jackson Lake springsnail (Pyrgulopsis robusta Walker 1908). Journal of Freshwater Ecology 22: 647-653.

US Forest Service, Pacific Northwest Region. Invasive Aquatic Species. [Available at: http://www.fs.usda.gov/detail/r6/forest-grasslandhealth/invasivespecies/?cid=stelprdb5302184]

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