Campeloma decisum

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Campeloma decisum
Secure
Secure (NatureServe)[2]
Scientific classification Edit this classification
Kingdom: Animalia
Phylum: Mollusca
Class: Gastropoda
Subclass: Caenogastropoda
Order: Architaenioglossa
Family: Viviparidae
Genus: Campeloma
Species:
C. decisum
Binomial name
Campeloma decisum
(Say, 1817)

Campeloma decisum, commonly known as the pointed campeloma, is a species of freshwater snail in the family Viviparidae. It is native to lakes, streams, and rivers across eastern North America.

Description

Drawing of the shell and operculum by W. H. Dall.

C. decisum can be found in varied freshwater ecosystems throughout the eastern United States and southeast Canada. The shell shape of this species is highly variable, and is dependent on various environmental factors such as pH, alkalinity, Secchi depth; and the concentration of ammonia, phosphate, and magnesium.[3]

Individuals can live approximately three years and reach sexual maturity after one year.[4] Historically, this species has been known to reproduce both sexually and asexually through parthenogenesis, with individual populations being composed of either males and females or entirely asexual females.[5] Recent genetic studies have indicated that C. decisum likely represents two or more distinct taxa, with sexual populations being related to other sexual Campeloma species and asexual populations being related to the sexual C. geniculum and other asexual Campeloma species.[6] This diversification likely occurred during the Miocene.

Ecology

C. decisum is known for its tendency to burrow in order to shelter from predators like fish and diving ducks. As a result, they do not thrive in aquatic environments with hard substrates. The growth rate and ability of these snails to burrow is negatively affected by the presence of the invasive zebra mussel, Dreissena polymorpha.[7] Known parasites of the species include the trematode Aspidogaster conchicola.[8]

References

  1. Cordeiro, J.; Ormes, M. (2017). "Campeloma decisum". IUCN Red List of Threatened Species. 2017 e.T69632293A69633263. doi:10.2305/IUCN.UK.2017-3.RLTS.T69632293A69633263.en. Retrieved 4 March 2026.
  2. NatureServe. "Campeloma decisum". NatureServe Explorer. Arlington, Virginia. Retrieved 4 March 2026.
  3. Western, Lauren; Zanatta, David T. (2025). "Identifying Environmental Drivers of Shell Shape Variation in the Freshwater Gastropod Campeloma decisum (Say, 1817)". American Malacological Bulletin. 41 (1). doi:10.4003/006.041.0108. ISSN 0740-2783.
  4. Brown, Kenneth M.; Varza, Dennis; Richardson, Terry D. (1989). "Life Histories and Population Dynamics of Two Subtropical Snails (Prosobranchia:Viviparidae)". Journal of the North American Benthological Society. 8 (3). [University of Chicago Press, Society for Freshwater Science]: 222–228. JSTOR 1467325. Retrieved 2023-01-10.
  5. Johnson, Steven G (1992). "Spontaneous and hybrid origins of parthenogenesis in Campeloma decisum (freshwater prosobranch snail)". Heredity. 68 (3). Springer Science and Business Media LLC: 253–261. doi:10.1038/hdy.1992.38. ISSN 0018-067X.
  6. Bower, Aaron M.; Anderson, Frank E.; Minton, Russell L. (2025-08-22). "DNA Barcoding Suggests Sexual and Asexual Campeloma decisum (Say, 1817) (Gastropoda: Viviparidae) are Different Taxa". American Malacological Bulletin. 42 (1). doi:10.4003/006.042.0105. ISSN 0740-2783.
  7. Van Appledorn, Molly; Lamb, David A.; Albalak, Kinneret; Bach, Catherine E. (2007). "Zebra mussels decrease burrowing ability and growth of a native snail, Campeloma decisum". Hydrobiologia. 575 (1): 441–445. doi:10.1007/s10750-006-0280-3. ISSN 0018-8158.
  8. Alevs, Philippe V.; Vieira, Fabiano M.; Santos, Cláudia P.; Scholz, Tomáš; Luque, José L. (2015-02-12). "A Checklist of the Aspidogastrea (Platyhelminthes: Trematoda) of the World". Zootaxa. 3918 (3): 339–96. doi:10.11646/zootaxa.3918.3.2. hdl:11104/0249438. ISSN 1175-5334. PMID 25781098.