Aplexa elongata - (Say, 1821)
Lance Aplexa
Synonym(s): Sibirenauta elgonataus (Say, 1821)
Taxonomic Status: Accepted
Related ITIS Name(s): Aplexa elongata (Say, 1821) (TSN 76697)
French Common Names: physe des mousses
Unique Identifier: ELEMENT_GLOBAL.2.107761
Element Code: IMGASL8010
Informal Taxonomy: Animals, Invertebrates - Mollusks - Freshwater Snails
 
Kingdom Phylum Class Order Family Genus
Animalia Mollusca Gastropoda Basommatophora Physidae Aplexa
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Concept Reference
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Concept Reference: Turgeon, D.D., J.F. Quinn, Jr., A.E. Bogan, E.V. Coan, F.G. Hochberg, W.G. Lyons, P.M. Mikkelsen, R.J. Neves, C.F.E. Roper, G. Rosenberg, B. Roth, A. Scheltema, F.G. Thompson, M. Vecchione, and J.D. Williams. 1998. Common and scientific names of aquatic invertebrates from the United States and Canada: Mollusks. 2nd Edition. American Fisheries Society Special Publication 26, Bethesda, Maryland: 526 pp.
Concept Reference Code: B98TUR01EHUS
Name Used in Concept Reference: Aplexa elongata
Taxonomic Comments: Note that North American snails of this species have mistakenly been referred to the Eurasian species, Aplexa hypnorum (Linnaeus, 1758) (see Te, 1980; Taylor, 2003). An example of this type of error can be found in Clarke (1981) and Pip (2000). Taylor (2003) lists this species as Sibirenauta elongatus. Taylor (2003) also lists another species, Sibirenauta [= Aplexa) pictus (Krause, 1883) that occurs from Chukotka in the basin of the river Kolyma, eastward to Lawrence Bay (Lavrentii Zaliv], in northern Alaska and offshore on St. Matthew Island; in northern Yukon, Northwest Territories on the arctic coast northward to Banks and Victoria Islands of the Arctic Archipelago, but there is some question as to whether this may represent a form or subspecies of Aplexa elongata. A study of molecular phylogeny of the family Physidae conducted by Wethington and Lydeard (2007) resulted in proposed monophyly of the family and supported six major clades, each with a corresponding difference in penial morphology; with Aplexa elongata falling within the Aplexa 1 group.
Conservation Status
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NatureServe Status

Global Status: G5
Global Status Last Reviewed: 06Mar2015
Global Status Last Changed: 14Sep1999
Ranking Methodology Used: Ranked by calculator
Rounded Global Status: G5 - Secure
Reasons: This species is ranked as secure in view of its wide distribution, presumed large population, and lack of known threats.
Nation: United States
National Status: N5 (14Sep1999)
Nation: Canada
National Status: N5 (01Aug2017)

U.S. & Canada State/Province Status
Due to latency between updates made in state, provincial or other NatureServe Network databases and when they appear on NatureServe Explorer, for state or provincial information you may wish to contact the data steward in your jurisdiction to obtain the most current data. Please refer to our Distribution Data Sources to find contact information for your jurisdiction.
United States Alaska (SNR), Colorado (S4), Connecticut (S2), District of Columbia (SNR), Idaho (S3), Illinois (SNR), Indiana (SNR), Iowa (SNR), Maine (SNR), Maryland (SNR), Massachusetts (S4), Michigan (SNR), Montana (SNR), Nebraska (SNR), Nevada (SNR), New Hampshire (SNR), New York (S2), North Dakota (SNR), Ohio (SNR), Oregon (SNR), Pennsylvania (S3S4), South Dakota (SNR), Utah (SH), Vermont (SNR), Virginia (SNR), Washington (S3S4), Wisconsin (SU), Wyoming (S3)
Canada Alberta (S4S5), British Columbia (S5?), Manitoba (S5), New Brunswick (SU), Northwest Territories (SNR), Nova Scotia (SU), Nunavut (SU), Ontario (S5), Prince Edward Island (SU), Quebec (SNR), Saskatchewan (SU), Yukon Territory (SU)

Other Statuses

NatureServe Global Conservation Status Factors

Range Extent: >2,500,000 square km (greater than 1,000,000 square miles)
Range Extent Comments: This species has a broad distribution across northern North America. It ranges from Northwest Territories, Canada, from the vicinity of Great Slave Lake southeast (south of Hudson Bay) to Anticosti Island, Quebec, and Nova Scotia; south through British Columbia, eastern Washington and eastern Oregon to southernmost Utah and Colorado; east across the Great Plains from northeastern Colorado through northern Nebraska to central Illinois, through Indiana and Ohio to Pennsylvania and eastern Massachusetts; also in Illinois and Ohio there are early records from south of the modern known range (Taylor, 2003).

Number of Occurrences: > 300
Number of Occurrences Comments: This species is represented by a large number of occurrences (subpopulations).

Population Size: >1,000,000 individuals

Number of Occurrences with Good Viability/Integrity: Many to very many (41 to >125)

Overall Threat Impact: Low
Overall Threat Impact Comments: Given the large geographic distribution of this species, it is unlikely that any major threat is impacting its global population. However, some sub-populations may be experiencing localized declines due to habitat loss and degradation.

Short-term Trend: Relatively Stable (<=10% change)
Short-term Trend Comments: Trend over the past 10 years is unknown, but presumed stable overall. There may be localized declines; it was not found in surveys conducted in Indiana in 2006-2008, even though it had been considered abundant at some sites in 1982 (Pyron et al. 2008).

Environmental Specificity: Narrow. Specialist or community with key requirements common.
Environmental Specificity Comments: In a study of physid distribution across habitat gradient as a response to predators, this species was found to be most successful in shallow, temporary ponds with few predators (Turner and Montgomery, 2009).

Other NatureServe Conservation Status Information

Distribution
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Global Range: (>2,500,000 square km (greater than 1,000,000 square miles)) This species has a broad distribution across northern North America. It ranges from Northwest Territories, Canada, from the vicinity of Great Slave Lake southeast (south of Hudson Bay) to Anticosti Island, Quebec, and Nova Scotia; south through British Columbia, eastern Washington and eastern Oregon to southernmost Utah and Colorado; east across the Great Plains from northeastern Colorado through northern Nebraska to central Illinois, through Indiana and Ohio to Pennsylvania and eastern Massachusetts; also in Illinois and Ohio there are early records from south of the modern known range (Taylor, 2003).

U.S. States and Canadian Provinces

Due to latency between updates made in state, provincial or other NatureServe Network databases and when they appear on NatureServe Explorer, for state or provincial information you may wish to contact the data steward in your jurisdiction to obtain the most current data. Please refer to our Distribution Data Sources to find contact information for your jurisdiction.
Color legend for Distribution Map
Endemism: occurs (regularly, as a native taxon) in multiple nations

U.S. & Canada State/Province Distribution
United States AK, CO, CT, DC, IA, ID, IL, IN, MA, MD, ME, MI, MT, ND, NE, NH, NV, NY, OH, OR, PA, SD, UT, VA, VT, WA, WI, WY
Canada AB, BC, MB, NB, NS, NT, NU, ON, PE, QC, SK, YT

Range Map
No map available.


U.S. Distribution by County Help
State County Name (FIPS Code)
ID Bear Lake (16007), Teton (16081)
UT Morgan (49029)*, Rich (49033)*, Uintah (49047)*, Washington (49053)*, Weber (49057)*
* Extirpated/possibly extirpated
U.S. Distribution by Watershed Help
Watershed Region Help Watershed Name (Watershed Code)
14 Ashley-Brush (14060002)+*, Duchesne (14060003)+*
15 Upper Virgin (15010008)+*, Fort Pierce Wash (15010009)+*, Lower Virgin (15010010)+*
16 Bear Lake (16010201)+, Upper Weber (16020101)+*, Lower Weber (16020102)+*
17 Teton (17040204)+
+ Natural heritage record(s) exist for this watershed
* Extirpated/possibly extirpated
Ecology & Life History
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Habitat Type: Freshwater
Non-Migrant: N
Locally Migrant: N
Long Distance Migrant: N
Riverine Habitat(s): CREEK, Pool
Lacustrine Habitat(s): Shallow water
Palustrine Habitat(s): FORESTED WETLAND, HERBACEOUS WETLAND, TEMPORARY POOL
Special Habitat Factors: Benthic
Habitat Comments: This species lives in different habitats including temporary pools, dried up ponds, under moist leaves, ravines, clean brooks, ponds, and lake margins (Taylor, 2003).
Economic Attributes Not yet assessed
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Management Summary Not yet assessed
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Population/Occurrence Delineation
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Group Name: Freshwater Snails

Use Class: Not applicable
Minimum Criteria for an Occurrence: Occurrences are based on some evidence of historical or current presence of single or multiple specimens, including live specimens or recently dead shells (i.e., soft tissue still attached without signs of external weathering or staining), at a given location with potentially recurring existence. Weathered shells constitute a historic occurrence. Evidence is derived from reliable published observation or collection data; unpublished, though documented (i.e. government or agency reports, web sites, etc.) observation or collection data; or museum specimen information.
Mapping Guidance: Unlike most freshwater mussels [possibly excepting Uniomerus tetralasmus (Say, 1831) (see Isley, 1914)], some freshwater pulmonates are able to survive in intermittent streams and ponds by settling into sediment on the bottom and aestivating in otherwise dry or frozen conditions. Some species (e.g. Stagnicola spp.) may form a sheet of mucus just within the aperture called an epiphragm that effectively seals the snail from harsh external conditions (Jokinen, 1978; Brown, 1991). For ephemeral or intermittent water species, it may be particularly difficult to define the limits of an occurrence. Movement out of the water for the purposes of aestivation is on the order of cm (Jokinen, 1978), not m or km, so this behavior should not affect separation distance between occurrences. Species that may be found in intermittent waters include: Aplexa elongata, Fossaria bulimoides, F. dalli, F. modicella, F. obrussa, F. parva, Gyraulus circumstriatus, G. crista, G. parvus, Laevapex fuscus, Physa vernalis, Physella gyrina, Planorbella campestris, Planorbula armigera, Stagnicola caperata, S. elodes, S. exilis.
Separation Barriers: Separation barriers are largely based on permanent hydrological discontinuity between water bodies, with distances of 30 meters or greater between maximum high water marks constituting a separation barrier. Additional barriers are chemical and/or physical and include any connecting water body (regardless of size) with one or more of the following on a permanent basis: no dissolved calcium content, acidity greater than pH 5, lack of dissolved oxygen, extremely high salinity such as that found in saline lakes and brine waters, or temperature greater than 45

An additional physical barrier, particularly for flowing water, is presence of upland habitat between water connections. High waterfalls and anthropogenic barriers to water flow such as dams are barriers as they limit movement in an upstream direction.

Separation Distance for Unsuitable Habitat: 2 km
Separation Distance for Suitable Habitat: 2 km
Alternate Separation Procedure: Freshwater cave species (mostly prosobranchs) may occur near entrances to very deep in cave systems with specimens occurring on the undersides of small stones in riffle areas (Hershler et al., 1990). For cave species, separation distance cannot often be determined accurately due to varying degrees of accessibility to occupied cave habitat. In these instances, each cave where an observation or collection was recorded (see Minimum EO Criteria, above) constitutes an element occurrence regardless of separation distance. Multiple caves within a single hydrological cave system are each considered separately. Caves with multiple entrances and passages known to be connected, but with connecting passages too small or unsafe for human entry shall be treated as a single element occurrence when the non-negotiable portion of the cave is thought to be less than approximately 300 m linear length. Species known to occur in caves include: Amnicola cora, Antrobia spp., Antrobis spp., Antroselates spp., Dasyscias spp., Fontigens aldrichi, F. antroecetes, F. bottimeri, F. morrisoni, F. nickliniana, F. orolibas, F. prosperpina, F. tartarea, F. turritella, Holsingeria spp., Phreatodrobia spp., Stygopyrgus spp.
Separation Justification: Freshwater snails have adapted to most North American habitats including permanent standing, intermittent, and flowing waters. As a whole, pulmonates (previously Subclass Pulmonata) are better dispersers than prosobranchs (previously Subclass Prosobranchia). Pulmonates adapt better to changing temperature and oxygen concentration, resist desiccation better (use pulmonary respiration, store excreted nitrogen as urea, aestivate), and have faster crawling rates (including righting response and actual movement rate) than prosobranchs (Brown et al., 1998). Some species are more tolerant to adverse habitat conditions such as high pollution levels (e.g. Physella spp.), high altitude [e.g. Acroloxus coloradensis (Henderson, 1930)], underground cave pools and springs (e.g. Fontigens spp., Phreatodrobia spp.) and hot springs (e.g. Pyrgulopsis spp.).

Precise geographic distribution of many American freshwater snails is not known but presumably reflects past geological, geographic, and climatic change (Smith, 1989). Movements between isolated or inaccessible portions of water bodies is possible but dependent on outside, passive processes (e.g. rafting, periodic flooding, transport by vertebrates, introduction by humans). Long-distance dispersal is generally not considered when assigning separation distances as otherwise impracticably large separation distances would result.

Several factors contribute to limiting freshwater snail distribution but none apply across diverse habitats or taxa. Approximately 95% of all freshwater gastropods are restricted to waters with calcium concentrations greater than 3 mg/liter (Brown, 1991; for exceptions see Jokinen, 1983). Calcium uptake for shell construction requires energy expenditure (active transport) when calcium concentration is low, but is passive at higher concentrations (Greenaway, 1971). Typically, no known biotic or abiotic factors consistently limit the abundance or distribution of freshwater gastropods among sites (DeVries et al., 2003). At specific localities, limiting factors may include hardness, acidity, dissolved oxygen, salinity, high temperature, and food availability as associated with depth (Smith, 1989). Most species and the largest populations occur in hard, alkaline waters with normal range 20-180 ppm (Shoup, 1943; Harman, 1974). Snails are uncommon in habitats with surface acidity greater than pH 5 (see also Jokinen, 1983). Dissolved oxygen limits diversity so severely polluted waters (oxygen consumed by algae blooms) are often devoid of freshwater snails excepting pollution tolerant species. Because pulmonates can utilize atmospheric oxygen, they can exist under anaerobic conditions for longer time periods (Harman and Berg, 1971; Harman, 1974; McMahon, 1983). High salinity is limiting to freshwater gastropods and inland saline lakes generally lack an associated snail fauna. Most species (excepting hot springs species) are intolerant of temperatures greater than 45ēC (McDonald, 1969; van der Schalie and Berry, 1973), a condition rarely occurring naturally. Lower temperatures are less limiting as snails have been found foraging in ice-covered waters (Harman and Berg, 1971; Harman, 1974). Most species live in the shallows, (depths less than 3 m) where food abundance is greatest. As a result, drastic water fluctuations (draw-downs) may cause declines in snail populations (Hunt and Jones, 1972).

Any contiguous, occupied stretch of suitable flowing water habitat 2 km long or greater is considered an element occurrence. Two km was chosen based upon the limited active movement capabilities of most benthic invertebrates and observed home range of freshwater snails (J. Cordeiro, personal observation) as well as the relatively short life span of most species (five years for most stream species and two years for most pond species).

Date: 18Oct2004
Author: Cordeiro, J.
Notes: Prosobranchs: Neritidae: Neritina; Viviparidae: Campeloma, Cipangopaludina, Lioplax, Tulotoma, Viviparus; Ampullariidae: Marisa, Pomacea; Pleuroceridae: Elimia, Goniobasis, Gyrotoma, Io, Juga, Leptoxis, Lithasia, Pleurocera; Thiaridae: Melanoides, Tarebia; Bithyniidae: Bithynia; Hydrobiidae: Amnicola, Antrobia, Antrorbis, Antroselates, Aphaostracon, Balconorbis, Birgella, Cincinnatia, Clappia, Cochliopa, Cochliopina, Colligyrus, Dasyscias, Eremopyrgus, Floridiscrobs, Fluminicola, Fontelicella, Fontigens, Gillia, Heleobops, Holsingeria, Hoyia, Hydrobia, Lepyrium, Littoridina, Littoridinops, Lyogyrus, Notogillia, Onobops, Paludina, Phreatoceras, Phreatodrobia, Potamopyrgus, Pristinicola, Probythinella, Pyrgophorus, Pyrgulopsis, Rhapinema, Somatogyrus, Spilochlamys, Spurwinkia, Stiobia, Stygopyrgus, Taylorconcha, Texadina, Texapyrgu, Tryonia; Assimineidae: Assiminea; Pomatiopsidae: Pomatiopsis, Heterostropha; Valvatidae: Valvata
MORE IN BCD EO SPECS NOTES TAB

Population/Occurrence Viability
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U.S. Invasive Species Impact Rank (I-Rank) Not yet assessed
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Authors/Contributors
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NatureServe Conservation Status Factors Edition Date: 06Mar2015
NatureServe Conservation Status Factors Author: Cordeiro, J. (2008), Ormes, M. (2015)
Element Ecology & Life History Edition Date: 21Feb2008
Element Ecology & Life History Author(s): Cordeiro, J.

Zoological data developed by NatureServe and its network of natural heritage programs (see Local Programs) and other contributors and cooperators (see Sources).

References
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