Article · Wikipedia archive · Last revised Aug 2, 2026

Gyraulus parvus

Gyraulus parvus is a species of freshwater snail in the family Planorbidae, the ram's horn snails. It is known by the common name ash gyro. It is native to much of North America and the Caribbean, where it occurs in Canada, the United States, Mexico, Hispaniola, Jamaica, and Cuba. It is also an introduced species in Eurasia, including Austria, the Czech Republic, France, Germany, and Israel.

Last revised
Aug 2, 2026
Read time
≈ 2 min
Length
433 w
Citations
11
Source
Wikipedia ↗
Gyraulus parvus
Secure
Secure (NatureServe)2
Scientific classification Edit this classification
Kingdom: Animalia
Phylum: Mollusca
Class: Gastropoda
Superorder: Hygrophila
Family: Planorbidae
Genus: Gyraulus
Species:
G. parvus
Binomial name
Gyraulus parvus
(Say, 1817)3
Synonyms
List
  • Anisus (Gyraulus) laevis (Alder, 1838)
  • Gyraulus (Gyraulus) laevis (Alder, 1838)
  • Gyraulus (Torquis) laevis (Alder, 1838)
  • Gyraulus (Torquis) parvus (Say, 1817)
  • Gyraulus cressmani F. C. Baker, 1942 †
  • Gyraulus cyclostomus F. C. Baker, 1934 †
  • Gyraulus labiatus A. B. Leonard, 1948 †
  • Gyraulus laevis (Alder, 1838)
  • Gyraulus similaris (F. C. Baker, 1919)
  • Gyraulus vermicularis albolineatus J. Henderson, 1933
  • Planorbis (Gyraulus) glaber Jeffreys, 1830
  • Planorbis (Gyraulus) laevis Alder, 1838
  • Planorbis (Gyraulus) parvus Say, 1817
  • Planorbis billingsii I. Lea, 1864
  • Planorbis concavus J. G. Anthony, 1843
  • Planorbis elevatus C. B. Adams, 1840
  • Planorbis glaber Jeffreys, 1830
  • Planorbis glaber var. compressa Lloyd, 1874
  • Planorbis laevis Alder, 1838
  • Planorbis parvus Say, 1817
  • Planorbis parvus var. walkeri Vanatta, 1902
  • Planorbis similaris F. C. Baker, 1919
  • Planorbis similis F. C. Baker, 1919
  • Planorbis thermalis Westerlund, 1885

Gyraulus parvus is a species of freshwater snail in the family Planorbidae, the ram's horn snails. It is known by the common name ash gyro.142 It is native to much of North America and the Caribbean, where it occurs in Canada, the United States (including Puerto Rico), Mexico, Hispaniola, Jamaica, and Cuba. It is also an introduced species in Eurasia, including Austria, the Czech Republic, France, Germany, and Israel.1

This common snail occurs in many types of freshwater habitat, such as ponds and lakes.1 It consumes diatoms and other periphyton that it scrapes off of surfaces. It sometimes rests attached to water plants.4

This snail has a thin, transparent, whitish-gray shell measuring 2.5 to 5 millimeters wide. It has 4 to 5 whorls. The upper side is concave and the lower side is flat.5

This snail is an intermediate host for schistosomes that cause swimmer's itch.6

References

References

  1. Cordeiro, J.; Perez, K. (2012). "Gyraulus parvus". IUCN Red List of Threatened Species. 2012 e.T155684A734471. doi:10.2305/IUCN.UK.2012-1.RLTS.T155684A734471.en. Retrieved 1 November 2021.
  2. NatureServe. "Gyraulus parvus". NatureServe Explorer. Arlington, Virginia. Retrieved 5 March 2026.
  3. Say T. (1817). Conchology. pp. A-3 – C-6 [= 1–20], pl. [1–4], in: Nicholson W.: American edition of the British Encyclopedia, or, dictionary of arts and sciences comprising an accurate and popular view of the present improved state of human knowledge. First Edition. IV. pp. (?). Philadelphia. (Mitchell & Ames).
  4. Gyraulus parvus. Archived 2016-12-31 at the Wayback Machine Invertebrate Abstracts. Arizona Game and Fish Department.
  5. Gyraulus parvus. AnimalBase.
  6. Laman, T. G., et al. (1984). The role of Gyraulus parvus as an intermediate host for avian schistosomes. Proc Helminthol Soc Wash 51(2) 267-69.