Mollusca : Gastropoda : incertae sedis : PlanorbidaeSnails and slugs

Gyraulus albus (O. F. Müller, 1774)

White ramshorn

Gyraulus albus

Description: A small, loosely coiled, faintly glossy, sometimes dull-whitish shell. The surface sculpture is characteristic and has radial growth lines inter-cut with strong radial striae. The body whorl expands strongly to produce a wide, broadly oval aperture which meets the previous whorl at an obtuse angle. Widespread. 5-8 mm.

World Distribution: Distributed across the northern hemiphere. Distribution type: Circumpolar Wide-temperate (66).

Irish Distribution: Rarely a dominant animal in any particular habitat, but one of the most prolific still water planorbids in our area. It occurs in all but the most dystrophic or acid of lake environments.

Ecology:

  • Usually inhabits deeper, weedy water in lakes and large ponds
  • Abundant in water to 20m depth within Lough Neagh and an item of diet for over-wintering diving ducks (Winfield & Winfield, 1994)
  • Prefers calcareous conditions but present in all but the most base-depleted lakes

Key Identification Features:

  • A small, loosely coiled, dull brown or whitish shell
  • Surface with strong radial growth lines inter-cut with strong spiral striae to produce a characteristic cross-striation
  • Body whorl expands strongly to produce a wide, broadly oval aperture which meets the previous whorl at an obtuse angle
  • Whorls convex, sutures deep

Red list status:

  • Least concern (lc).

Distribution Map from NBN: Gyraulus albus at National Biodiversity Network mapping facility, data for UK.

iNaturalist: Gyraulus albus at iNaturalist World Species Observations database.

GBIF data for Gyraulus albus | Classification: Gastropoda, incertae sedis, Planorbidae, Gyraulus

Thumbnails for genus Gyraulus

 Anderson, R., 2024. Gyraulus albus. (O. F. Müller, 1774). [In] MolluscIreland.
https://www2.habitas.org.uk/molluscireland/species.php?item=88. Accessed on 2024-12-26.