Mollusca : Gastropoda : incertae sedis : PlanorbidaeSnails and slugs

Gyraulus parvus (Say, 1817)

Smooth ramshorn

Gyraulus parvus

Description: A small, loosely coiled, pale brown, glossy shell. Aperture almost circular, meeting the previous whorl nearly at a right angle. Surface smooth, with radial growth lines only. 4.5-6 mm.

World Distribution: Found mainly in the northern parts of Europe across Siberia to north-east Asia. Distribution type: Eurasian Boreo-temperate (55).

Irish Distribution: Rare and perhaps declining. Very thinly scattered and mainly near the coast. The number of recorded sites has declined drastically compared to inventories made at the turn of the nineteenth century. Whether these changes are real or reflect less intensive recording effort in later years is unclear.

Ecology:

  • A pioneer species usually restricted to temporary or new habitats with hard or slightly saline water
  • These habitats do not have a rich assemblage of other species and rarely persist in this form or remain suitable for long
  • There is some evidence that pools in abandoned quarries can be attractive

Key Identification Features:

  • A small, loosely coiled, pale brown shell
  • Surface smooth and glossy with radial growth lines only
  • Aperture nearly circular, meeting the previous whorl at a near-right angle

Red list status:

  • Endangered (EN).

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

iNaturalist: Gyraulus parvus at iNaturalist World Species Observations database.

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

Thumbnails for genus Gyraulus

 Anderson, R., 2024. Gyraulus parvus. (Say, 1817). [In] MolluscIreland.
https://www2.habitas.org.uk/molluscireland/species.php?item=90. Accessed on 2024-12-27.