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Home/Species/ Brilliant Granule Snail

Guppya sterkii

(Dall, 1888)

Brilliant Granule Snail

G5Secure Found in 1 roadless area NatureServe Explorer →
G5SecureGlobal Rank
MediumThreat Impact
Identity
Unique IDELEMENT_GLOBAL.2.111758
Element CodeIMGAS71030
Record TypeSPECIES
ClassificationSpecies
Classification StatusStandard
Name CategoryInvertebrate Animal
Endemicoccurs (regularly, as a native taxon) in multiple nations
KingdomAnimalia
PhylumMollusca
ClassGastropoda
OrderStylommatophora
FamilyHelicarionidae
GenusGuppya
Other Common Names
Brillant Granule (EN) Sterki's Granule (EN) Sterki's Granule Snail (EN)
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.
Taxonomic Comments
Classification uncertain.
Conservation Status
Rank Method Rank calculation - Biotics v2
Review Date2025-09-19
Change Date2002-10-08
Edition Date2025-09-19
Edition AuthorsCordeiro, J. (2009); rev. T. Cornelisse (2025)
Threat ImpactMedium
Range Extent>2,500,000 square km (greater than 1,000,000 square miles)
Number of Occurrences> 300
Rank Reasons
Despite some potential localized threats, this species has a large range and number of occurrences, and it has been documented across its range consistently in recent years.
Range Extent Comments
This species occurs in Ontario, Canada and in the eastern United States from Wisconsin to Vermont, south to Florida and west to Texas, as well as south into Mexico (Lee 2006; Dourson and Feeman 2006; Hotopp and Pearce 2007; NatureServe 2025; RARECAT 2025; InvertEBase 2025).
Occurrences Comments
This species is known from at least approximately 381 occurrences using a 1 km separation distance and records from 1994-2025 (Lee 2006; Dourson and Feeman 2006; Hotopp and Pearce 2007; NatureServe 2025; RARECAT 2025; InvertEBase 2025).
Threat Impact Comments
This species is sensitive to habitat loss that reduces forest cover and leaf litter as well as trampling and off-road vehicle use (Nekola 2009; Forsyth and Nicolai 2018; Michigan Natural Areas Inventory 2025).
Ecology & Habitat

Habitat

This species is found in mixed hardwood forests at all elevations; this is likely one of the most common minuscule snail residents in leaf litter (Dourson 2013).
Terrestrial Habitats
Forest/WoodlandForest - HardwoodWoodland - Hardwood
Other Nations (2)
CanadaN3
ProvinceRankNative
OntarioS3Yes
United StatesN5
ProvinceRankNative
MississippiSNRYes
North CarolinaSUYes
West VirginiaS5Yes
PennsylvaniaS4Yes
MichiganS1Yes
OhioSNRYes
LouisianaSNRYes
WisconsinS2Yes
TennesseeS4Yes
MarylandSNRYes
MissouriSNRYes
South CarolinaSNRYes
AlabamaSNRYes
IowaSNRYes
New YorkSNRYes
IndianaSNRYes
GeorgiaSNRYes
OklahomaSNRYes
KentuckyS4Yes
ArkansasSNRYes
FloridaSNRYes
New JerseySNRYes
VermontSNRYes
TexasS2Yes
VirginiaS4Yes
IllinoisS3Yes
Threat Assessments
ThreatScopeSeverityTiming
1 - Residential & commercial developmentRestricted (11-30%)Serious or 31-70% pop. declineHigh (continuing)
1.1 - Housing & urban areasRestricted (11-30%)Serious or 31-70% pop. declineHigh (continuing)
6 - Human intrusions & disturbanceRestricted (11-30%)Moderate or 11-30% pop. declineHigh (continuing)
6.1 - Recreational activitiesRestricted (11-30%)Moderate or 11-30% pop. declineHigh (continuing)

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Roadless Areas (1)
Tennessee (1)
AreaForestAcres
Slide HollowCherokee National Forest4,057
References (15)
  1. Burke, T.E. 2013. Land snails and slugs of the Pacific Northwest. Oregon State University Press, Corvallis. 352 pp
  2. Dourson, D. and K. Feeman. 2006. A survey of terrestrial Mollusca in selected areas of the Land Between the Lakes National Recreation Area. Journal of the Kentucky Academy of Science, 67(1): 9-18.
  3. Dourson, D.C. 2010. Kentucky's land snails and their ecological communities. Goatslug Publications, Bakersville, NC. 298 pp.
  4. Dourson, D.C. 2013. Land snails of the Great Smoky Mountains National Park and southern Appalachians. Goatslug Publications, Bakersville, NC. 336 pp.
  5. Dourson, D C. and West Virginia DNR. 2015. Land snails of West Virginia. Goatslug Publications, Bakersville, North Carolina. 412 pp.
  6. Forsyth, R. and Nicolai, A., 2018. Guppya sterkii (Dall, 1888)(Gastropoda, Eupulmonata, Euconulidae) in eastern Ontario, Canada. Check List, 14(4), pp.579-583.
  7. Hotopp, K. and T.A. Pearce. 2007. Land snails in New York: statewide distribution and talus site faunas. Final Report for contract #NYHER 041129 submitted to New York State Biodiversity Research Institute, New York State Museum, Albany, New York. 91 pp.
  8. Hubricht, L. 1985. The distribution of the native land mollusks of the eastern United States. Fieldiana: Zoology 24:1-191.
  9. InvertEBase. 2025. Online. Available: https://invertebase.org/portal/index.php.
  10. Lee, H.G. 2006. Landsnails of Claiborne Bluff. American Conchologist, 34(3): 30-31.
  11. Michigan Natural Features Inventory. 2025. Rare Species Explorer (Web Application). Available online at http://mnfi.anr.msu.edu/explorer
  12. NatureServe. 2025. NatureServe Network Biodiversity Location Data. NatureServe, Arlington, Virginia.
  13. Nekola, J.C. 2009. Conservation prioritization of the Ontario and Quebec land snail faunas. Final Report submitted to Committee on the Status of Endangered Wildlife in Canada (COSEWIC), 8 June 2009. 120 pp.
  14. <p>NatureServe's Rapid Analysis of Rarity and Endangerment Conservation Assessment Tool (RARECAT). 2025. Version: 2.1.1 (released April 04, 2025).</p>
  15. 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.