SPECIES FACT SHEET

Scientific Name: Pyrgulopsis owyheensis Hershler and Liu, 2009Common Name: Owyhee upland pyrgPhylum: MolluscaClass: GastropodaOrder: LittorinimorphaFamily: Hydrobiidae(FMCS 2019)

Conservation Status : Global Status: G1G2 (last reviewed 10 March 2009)National Status (United States): N1N2State Status: S1S2 (Oregon)(NatureServe 2020)Federal Status (United States): None (USFWS 2020)IUCN Red List: Not assessed (IUCN 2020)

Taxonomic Note: The similarities in external shell morphology between taxa in the Hydrobiidae makes identification to species based on shell characters problematic (Frest and Johannes [n.d.]). Because of this, the distinctions between species within the Pyrgulopsis genus 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 mitochondrial DNA COI (mtCOI) protein sequence has been determined for P. owyheensis (Hershler and Liu 2009; UniProt 2020).

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

Pyrgulopsis owyheensis is closely similar to another regional congener, P. intermedia, but is differentiated by its smaller size as well as its typically disjunct inner shell lip, longer and narrower penial filament, more distally positioned ventral gland of penis, and unique mtCOI sequences (Hershler and Liu 2009). In addition to having unique mitochondrial DNA sequences, P. owyheensis is readily

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distinguished from another congener living in the Owyhee River basin, P. fresti, which has a broad, low-spired, squat shell and a large, disc-shaped, glandular ornament on its penis (Hershler and Liu 2009). P. fresti also lacks a seminal receptacle, a character which it uniquely shares with P. arizonae (Taylor 1987).

A technical description of this species, extracted from Hershler and Liu (2009), is as follows:

Small to medium-sized species having an ovate to narrow conic shell with medium to highly convex whorls. Penis having a medium-sized lobe and medium length filament. Penial ornament consisting of a transverse terminal gland, a penial gland, and a well-developed, distally positioned ventral gland. Shell height about 1.6-3.3 mm with 3.50 to 4.75 whorls. Periostracum tan or dark brown, thin. Protoconch near planispiral, about 1.5 whorls, diameter about 350 µm, surface entirely smooth or weakly wrinkled on initial 0.75 whorl. Teleoconch whorls medium or highly convex, narrowly and sometimes distinctively shouldered, last 0.5 to 0.25 whorl sometimes slightly loosened; sculpture of collabral growth lines. Aperture ovate, angled adapically. Inner lip usually disjunct, rarely adnate, usually thickened internally; columellar shelf absent; outer lip thin, weakly prosocline or orthocline. Umbilicus narrow or perforate; umbilical area sometimes having a narrow, adapertural groove. Shell measurements (mean + standard deviation in parentheses): height 2.13-2.78 mm (2.53 ± 0.16), width 1.79-2.19 mm (2.00 ± 0.11), body whorl height 1.87-2.39 mm (2.13 ± 0.12), body whorl width 1.43-1.89 mm (1.69 ± 0.10), aperture height 1.19-1.41 mm (1.29 ± 0.06), aperture width 1.05-1.32 mm (1.17 ± 0.07) (Hershler and Liu 2009).

Immature: Juvenile snails appear similar to adults but are smaller. Hydrobiidae eggs are typically laid in single capsules that are hemispherical and nongelatinous (Kabat and Hershler 1993).

See Attachment 4 for images of the shell of this species. Additional figures, including shell features, male and female genitalia, and radular and marginal teeth are provided in Hershler and Liu (2009).

Life History:The Pyrgulopsis genus, commonly known as springsnails, is an extremely diverse group of gill-breathing (prosobranch) aquatic snails in the Hydrobiidae family. Taxa in the genus typically have narrow geographic ranges and are obligately aquatic, inhabiting springs and a variety of other perennial freshwater habitats (Hershler 1994; Hershler and Sada 2002; Hershler and Liu 2009). Pyrgulopsis species are commonly found attached to hard substrates and emergent macrophytes, where they feed on periphyton, consisting of algae, bacteria, fungi, and diatoms (Hershler 1998).

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Adult: Specific information on the life history of this species is not available, but in general, Pyrgulopsis snails are short lived, surviving only one year (Frest and Johannes 1995). 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). However, studies on western prosobranch taxa suggest that some may live longer than a year and overwinter (Dillon 2004). An extended lifespan may allow for additional reproductive events, suggesting an iteroparous reproductive strategy in overwintering individuals (Lysne et al. 2007). The active season of this species is not well-documented, although known records for adults are from mid-May through mid-October (Deixis MolluscDB 2009; GBIF 2020; Hershler and Liu 2009; ORBIC 2020; USGS 2020).

In general, hydrobiid snails are sexually dimorphic, and the larger females tend to live longer. 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 occurs between March and July. 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).

Dispersal ability is unknown in this species, but it is likely constrained by physiological requirements, which limit them to aquatic habitats, and their intolerance for desiccation. Mechanisms for dispersal are suspected based on DNA evidence suggesting genetic similarity among isolated populations of Pyrgulopsis taxa (Hershler and Liu 2004a). Upstream migration may be a mechanism for active dispersal (Hershler and Liu 2004b); while passive dispersal may be mediated by attachment to waterfowl (Liu et al. 2003). Recent introductions of Pyrgulopsis taxa in the Columbia River basin are presumably human mediated (Johannes 2019).

Immature: Specific information on this species’ immature stages is not well known; however, other taxa in the family emerge from eggs as tiny juvenile snails about one month after oviposition.

Range, Distribution, and Abundance: Type Locality: Owyhee Spring, Malheur County, Oregon (Hershler and Liu 2009).

Range: This species is an Oregon endemic, known only from the Owyhee and Malheur River basins in the Northern Basin and Range Ecoregion.

Distribution: This recently described species is disjunctly distributed among five small groups of springs in southeastern Oregon (Owyhee River near

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Three Forks, Rattlesnake Creek drainage, Owyhee Spring area, lower Owyhee River, Malheur River drainage) (Hershler and Liu 2009). The type locality (Owyhee Spring) population of P. owyheensis is genetically differentiated from the other geographical subunits of this species (1.5-1.8% sequence divergence) and should perhaps be treated as a separate conservation unit (Hershler and Liu 2009).

Forest Service/BLM Lands: Documented: This species is documented on Vale District BLM land in Oregon.Suspected: This species is not suspected on additional BLM/Forest Service lands in Oregon.

Abundance: Abundance estimates for P. owyheensis are unknown.

Habitat Associations: In the West, Pyrgulopsis snails are typically associated with groundwater-influenced freshwater habitats, and many species are endemic to a single spring, spring complexes, or local drainages (Hershler and Sada 2002). As a group, Pyrgulopsis typically occupy small to large springs and spring-influenced portions of streams, lakes and rivers, and often occur in cold-water spring sources or headsprings; however, P. owyheensis is unique, and may occupy both cold and thermal springs (Hershler and Liu 2009). Many species require clean, moderately swift, well-oxygenated waters, typically with gravel-boulder substrates. These habitats provide stable temperatures, water chemistry, and flows needed to sustain their populations (Hershler 1998; Hershler and Sada 2002; Brown and Lydeard 2010).

This species of snail occurs disjunctly in five small spring habitats within the Owyhee and Malheur River basins in southeastern Oregon. P. owyheensis lives in spring sources and stream outflows, including both cold and thermal springs (Deixis MolluskDB 2009; Hershler and Liu 2009). It is found on a variety of hard substrates, including silt-gravel substrate with abundant grasses (Deixis MolluskDB 2009; Hershler and Liu 2009). Reported collection depths are from 0 to 7.6 cm (0 to 3 in.), at elevations of 1090 to 1095 m (3580 to 3590 ft.) (Deixis MolluskDB 2009).

This species co-occurs with the related P. intermedia in a spring along the Owyhee River above Long Sweetwater rapids. It also occurs with the invasive New Zealand mudsnail, Potamopyrgus antipodarum at a seep wall above the mouth of Crooked Creek (Hershler and Liu 2009). It was collected together with the oblique ambersnail, Oxyloma nuttalliana, at the Owyhee Spring site (Deixis MolluskDB 2009). In the Tudor Warm Springs area, P. owyheensis is occasionally sympatric with P. fresti, a hotspring snail restricted to thermal springs with temperatures of 24°C to 33°C (Hershler and Liu 2009). The

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Deixis database describes the collection sites for P. fresti as shallow warm springs flowing over alluvium and basalt pebble substrate or basalt bedrock with no macrophytes (Deixis MolluskDB 2009). 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).

Threats: Human population growth and climate change will likely intensify threats to freshwater ecosystems and greatly influence groundwater-dependent species extinctions (Hershler et al. 2014). Groundwater-dependent taxa in the Pyrgulopsis genus typically have very narrow geographic ranges and limited dispersal abilities; these life history needs and various current and potential threats put them at high risk of extinction (Frest and Johannes 1995; Hershler and Liu 2009; Johnson et al. 2013; Hershler et al. 2014). 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). More information on current specific threats to this species is needed, but there are likely multiple stressors on their populations, including pollution, habitat loss and degradation, climate change, and invasive species.

P. owyheensis is a narrow endemic with a very limited range, and is associated with clean, cold- and warm-water springs and seeps in an extremely arid region. This species, like others in the genus, depends on stable water chemistry and flows characteristic of spring sources. As a result, these snails are also sensitive to pollution, siltation, and hypoxia. Therefore, pollution and habitat alterations that affect groundwater and source flows, can adversely impact populations of this species.

Modifications to springs that negatively impact Pyrgulopsis species include livestock grazing (which tramples vegetation and pollutes the spring with excrement), recreational activities (such as bathing), diversion of water sources, and introduction of non-native or invasive species (Hershler 1998; Sada and Vinyard 2002). Some of the habitats where this species occurs are grazed rather heavily, and past modification of springs for a bathing pool appears to have impacted the snail populations at some historic sites (Frest and Johannes 1995). Road access on the east side of the Owyhee River crosses some spring runs but is not heavily used (Frest and Johannes 1995).

Impacts to habitat quality and quantity will likely be accelerated by climate change, which may lead to declines in groundwater reserves and springflows, increases in flash flooding, variability in precipitation, and intensified drought conditions in the West (reviewed in IPCC 2014; reviewed in Jiménez Cisneros et al. 2014). Climate change may also greatly impair

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groundwater recharge ability as precipitation patterns in the arid West are altered (Niraula et al. 2017), which could exacerbate already stressed water supplies due to intensive land-use practices and increased water demands (Maupin et al. 2014; IPBES 2018; reviewed in USGCRP 2018). Groundwater levels and associated springflows in this region continue to decline, even after some groundwater conservation measures were implemented after another declining western Pyrgulopsis species, P. bruneauensis, was listed in 1993 (Myler et al. 2007; Adkins and Bartolino 2012). If current rates of geothermal aquifer water withdrawal are not stabilized or reversed, there will continue to be declines in Pyrgulopsis populations.

In the Great Basin, aquatic gastropod taxa like P. owyheensis are further impacted by introductions of nonnative fishes and other freshwater mollusks (Sada and Vinyard 2002). Competition from invasive snails threaten this species; namely the exotic New Zealand mudsnail (Potamopyrgus antipodarum) which has been documented in the Snake River basin and co-occurs with P. owyheensis near the mouth of Crooked Creek (Hershler and Liu 2009). 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). Additional introductions include other nonnative gastropods (e.g., Melanoides tuberculata) and crustaceans (e.g., Procambarus sp.), the former of which may be responsible for springsnail and other native mollusk declines in the Great Basin (Hershler and Sada 1987). Overall, degradation of habitat, climate change, and nonnative species introductions will likely have extremely adverse effects on this species and its life cycle. Since Pyrgulopsis species are generally very rare and highly endemic, they are particularly sensitive to the above threats.

Conservation Considerations: Research: Because much of what is known of Pyrgulopsis taxa is primarily from two species (P. robusta, the widely distributed habitat generalist, and the range restricted P. bruneauensis, a thermal spring endemic), there is a need to better understand the detailed biology, distribution, and status of this species to inform conservation efforts. This includes specifics on its life cycle, fecundity, abundance, recruitment, dispersal ability, physiological tolerances, habitat usage, as well as their role in the food web and nutrient cycling. Research at known sites should include understanding the extent of specific threats to this species and its habitat (e.g., invasive snails and plants, grazing, and groundwater extraction).

Inventory: Quantitative sampling of snails is important to determine the population status of this species and density estimates in its habitat. Abundance estimates for this species at new and known sites would assist

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future conservation efforts, since population size is important in evaluating the stability of a species at a given locality. Additional surveys of springs and stream outflows in southeastern Oregon are needed in order to accurately delineate the geographic range of this species (Hershler and Liu 2009). Future surveys can occur in similar spring-influenced habitats in the Northern Basin and Range Ecoregion. Surveys for this species can also aid in the detection and understanding of extent of invasive Potamopyrgus antipodarum populations.

Management: New and known sites and their associated watersheds can be managed to reduce any associated impacts of grazing, water diversions, recreation, and other practices that would adversely affect any aspect of this species’ life cycle. Where grazing threatens spring systems, grazing practices could be limited and livestock could be excluded from sensitive areas. Because Pyrgulopsis snails are strictly associated with their aquatic habitat and are often endemic to small spring sites, habitat protection, including maintenance of water quality, substrate conditions, and riparian areas would likely benefit and help maintain populations of this species (Hershler 1998). Where impoundments or channelization of outflows occur in P. owyheensis habitat, conservation measures can include removal of structures that impede or limit flows and restoration of altered habitat. Where groundwater extraction threatens habitat, consider protecting these areas to restore environmental flows, support habitat for P. owyheensis, and conserve groundwater-dependent ecosystems.

Version 2:Prepared by: Michele BlackburnXerces Society for Invertebrate Conservation Date: June 2020

Reviewed by: Candace FallonXerces Society for Invertebrate Conservation Date: June 2020

Version 1:Prepared by: Sarah Foltz JordanXerces Society for Invertebrate Conservation Date: June 2010

Edited by: Sarina JepsenXerces Society for Invertebrate Conservation Date: July 2010

Recommended citation:

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Blackburn, M. and S. Foltz Jordan. 2020. Interagency Special Status/Sensitive Species Program (ISSSSP) Species Fact Sheet: Pyrgulopsis owyheensis. USDA Forest Service Region 6 and USDI Bureau of Land Management Oregon State Office. 17 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 Species Distribution in Oregon(4) Images of the Shells of this Species(5) Aquatic Gastropod Survey Protocol, including specifics for

this species

ATTACHMENT 1: References Adkins, C.B. and J.R. Bartolino. 2012. Historical and potential groundwater drawdown in the Bruneau area, Owyhee County, southwestern Idaho; Scientific Investigations Report; 2012-5119; U.S. Department of the Interior, U.S. Geological Survey. Prepared in cooperation with the U.S. Fish and Wildlife Service. Reston, Virginia. 36 pp.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, volume V: 9-14.Deixis MolluscDB database. 2009. An unpublished collection of mollusk records maintained by Ed Johannes.Dillon, R.T. 2004. The Ecology of Freshwater Molluscs. Cambridge University Press, Cambridge, UK. 523 pp.[FMCS] 2019. Freshwater Mollusk Conservation Society. The 2019 checklist of freshwater gastropods (Mollusca: Bivalvia: Unionida) of the United States and Canada. Considered and approved by the Gastropod Names Subcommittee 14 April 2019.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. Johannes. Hershler, R. 1994. A review of the North American freshwater snail genus Pyrgulopsis (Hydrobiidae). Smithsonian Contributions to Zoology 554:1-115.

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Hershler, R. 1998. A systematic review of the Hydrobiid snails (Gastropoda: Rissooidea) of the Great Basin, Western United States. Part I. Genus Pyrgulopsis. The Veliger 41(1):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 assigned to the North American freshwater gastropod subgenus Natricola (Rissooidea: Hydrobiidae). The Veliger 47(1): 66-81.Hershler, R. and H. 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 2006:1-22.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. 1987. Springsnails (Gastropoda: Hydrobiidae) of Ash Meadows, Amargosa Basin, California-Nevada. Proceedings of the Biological Society of Washington 100:776-843.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.[IPBES] 2018. The Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services. The IPBES regional assessment report on biodiversity and ecosystem services for the Americas. Rice, J., Seixas, C. S., Zaccagnini, M. E., Bedoya-Gaitán, M., and Valderrama N. (eds.). Secretariat of the IPBES, Bonn, Germany. 656 pp.[IPCC] 2014. Intergovernmental Panel on Climate Change. Climate Change 2014: Synthesis Report. Contribution of Working Groups I, II and III to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change [Core Writing Team, R.K. Pachauri and L.A. Meyer (eds.)]. IPCC, Geneva, Switzerland, 151 pp.[IUCN] 2020. International Union for Conservation of Nature and Natural Resources. The IUCN Red List of Threatened Species. Version 2020-1. Available at: https://www.iucnredlist.org [Accessed May 2020].Jiménez Cisneros, B.E., T. Oki, N.W. Arnell, G. Benito, J.G. Cogley, P. Döll, T. Jiang, and S.S. Mwakalila. 2014. Freshwater resources. In: Climate Change 2014: Impacts, Adaptation, and Vulnerability. Part A: Global and Sectoral Aspects. Contribution of Working Group II to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change [Field, C.B., V.R. Barros, D.J. Dokken, K.J. Mach, M.D. Mastrandrea, T.E. Bilir, M. Chatterjee, K.L. Ebi, Y.O. Estrada, R.C. Genova, B. Girma, E.S. Kissel, A.N. Levy, S. MacCracken, P.R.

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Mastrandrea, and L.L. White (eds.)]. Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA, p. 229-269.Johannes, E.J. 2019. Pyrgulopsis robusta (Walker, 1908) in the Columbia River: an introduction. Tentacle 27:10-13.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., 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., 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.Maupin, M.A., J. F. Kenny, S.S. Hutson, J.K. Lovelace, N.L. Barber, and Kristin S. Linsey. 2014. Estimated Use of Water in the United States in 2010. USGC Circular 1405. U.S. Geological Survey, Reston, VA. 56 pp.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(2): 199-205. NatureServe. 2020. Pyrgulopsis owyheensis Hershler and Liu, 2009. NatureServe Explorer [web application]. NatureServe, Arlington, Virginia. Available at: http://www.natureserve.org/explorer/ [Accessed May 2020].Niraula, R., T. Meixner, F. Dominguez, N. Bhattarai, M. Rodell, H. Ajami, D. Gochis, and C. Castro. 2017. How might recharge change under projected climate change in the western US?. Geophysical Research Letters 44(20): 10-407. 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. 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. Taylor, D.W. 1987. Fresh-water molluscs from New Mexico and vicinity. New Mexico Bureau of Mines & Mineral Resources Bulletin 116: 1-50.

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UniProt. 2019. Pyrgulopsis owyheensis. UniProtKB database. [online database] Available at: https://www.uniprot.org/. [Accessed May 2020].[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.[USFWS] 2020. United States Fish and Wildlife Service. Environmental Conservation Online System (ECOS). Online database. Available at: https://ecos.fws.gov/ecp0/reports/ad-hoc-species-report-input [Accessed May 2020].[USGCRP] 2018. U.S. Global Change Research Program. Impacts, Risks, and Adaptation in the United States: Fourth National Climate Assessment, Volume II [Reidmiller, D.R., C.W. Avery, D.R. Easterling, K.E. Kunkel, K.L.M. Lewis, T.K. Maycock, and B.C. Stewart (eds.)]. Washington, DC, USA, 1515 pp.

Map references: Deixis MolluscDB database. 2009. An unpublished collection of mollusk records maintained by Ed Johannes. [GBIF] 2020. Global Biodiversity Information Facility. [online database]. Available at: www.gbif.org [Accessed May 2020].Hershler, R. and H. 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 2006:1-22. [ORBIC] 2020. Oregon Biodiversity and Information Center. GIS export provided to Candace Fallon, the Xerces Society, by Lindsey Wise, Biodiversity Data Manager, January 2020.[USGS] 2020. U.S. Geological Survey. Species occurrence data for the Nation—USGS Biodiversity Information Serving Our Nation (BISON) (ver. 1.1, May 2019). Available at: https://bison.usgs.gov/#home [Accessed May 2020].

ATTACHMENT 2: List of pertinent, knowledgeable contacts: Ed Johannes, Deixis Consultants, Seattle-Tacoma, Washington.Robert Hershler, Research Zoologist Emeritus, Smithsonian National Museum of Natural History, Washington DC.

ATTACHMENT 3: Map of Species Distribution in Oregon

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Records of Pyrgulopsis owyheensis in Oregon relative to Forest Service and BLM lands. A map showing overlap of P. owyheensis with other Pyrgulopsis species is provided in Hershler and Liu (2009).

ATTACHMENT 4: Images of this species

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Shells of P. owyheensis. A—I Shells. Scale bar = 1.0 mm. A. Holotype, USNM 883435. B, USNM 1071259. C. USNM 1092854. D. USNM 1115390. E. USNM 1115400. F. USNM 1115388. G. USNM 1107074. H. USNM 1107073. I. USNM 1102152. J. Shell apex, USNM 1102152. Scale bar = 100 µm. K. Close-up of protoconch sculpture, USNM 1102152. Scale bar = 100 µm. Figure extracted from Hershler and Liu (2009); used with permission.

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ATTACHMENT 5: Aquatic Gastropod Survey Protocol, including specifics for this species:

Survey Protocol

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, 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

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Species-specific survey details:Pyrgulopsis owyheensis

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). 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 owyheensis 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/.

P. owyheensis is readily distinguished from other congeners living in the Owyhee River basin and adjacent drainages by its small size and ovate to narrow conic shell with medium to highly convex whorls and distinct inner lip. Characters of the penial filament and ventral gland of the penis also help distinguish this species (Hershler and Liu 2009), in addition to other characters outlined in the Species Fact Sheet. Expert identification is recommended for this species.

Where: Surveys for P. owyheensis can occur in small-medium, cold to warm springs, seep walls, and spring-influenced creeks in southeastern Oregon. P. owyheensis is disjunctly distributed among five small groups of springs and seepage habitats in southeastern Oregon (Owyhee River near Three Forks, Rattlesnake Creek drainage, Owyhee Spring area, lower Owyhee River, Malheur River drainage) (Hershler and Liu 2009). Conduct surveys in both cold and warm springs (24 to 33°C), at depths less than 7.62 cm (3 in.). Hand or dip net collection are the recommended survey techniques for this species (Deixis MolluscDB 2009). Search for snails fastened to rocks or in silt, sand, gravel, loose cobble substrates, and within and among emergent

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vegetation. Since the most recent collections by R. Hershler and others are over a decade old (2002 to 2007) (Hershler and Liu 2009), future surveys should confirm that this species is extant at known sites. Surveys of the surrounding area are still needed in order to accurately delineate the geographic range of this species and identify its conservation needs. In particular, future surveys of seeps and springs in the areas between the known sites in southeastern Oregon are recommended in order to determine whether the intervening areas are also inhabited by this species (Hershler and Liu 2009). Ongoing monitoring of known sites is recommended to determine population trends and potential and current habitat threats including groundwater extraction and drawdown. Re-evaluation of this species’ status at these sites is critical to identify both its current distribution and its conservation needs. 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.

When: In Oregon, P. owyheensis has been collected from May through October (Deixis MolluscDB 2009; GBIF 2020; Hershler and Liu 2009; ORBIC 2020; USGS 2020). Sampling in springs can be conducted any time of year, but for semelparous (i.e., lay eggs once at maturity and die) snails like many 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. When possible, 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 coldest months to improve detection of bottom-dwelling species. These and other recommendations are outlined further in Duncan (2008).

References: (Survey Protocol only)Deixis MolluscDB database. 2009. An unpublished collection of mollusk records maintained by Ed Johannes.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].

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[GBIF] 2020. Global Biodiversity Information Facility. [online database]. Available at: www.gbif.org [Accessed May 2020].Hershler, R. and H. 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 2006:1-22.[ORBIC] 2020. Oregon Biodiversity and Information Center. GIS export provided to Candace Fallon, the Xerces Society, by Lindsey Wise, Biodiversity Data Manager, January 2020.US Forest Service, Pacific Northwest Region. Invasive Aquatic Species. [Available at: http://www.fs.usda.gov/detail/r6/forest-grasslandhealth/invasivespecies/?cid=stelprdb5302184][USGS] 2020. U.S. Geological Survey. Species occurrence data for the Nation—USGS Biodiversity Information Serving Our Nation (BISON) (ver. 1.1, May 2019). Available at: https://bison.usgs.gov/#home [Accessed May 2020].

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