MolluscIreland - land and freshwater
  • Planorbis planorbis (Linnaeus 1758) Margined ramshorn
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Planorbis planorbis
© Dr Roy Anderson
Planorbis planorbis
© Dr Roy Anderson
Planorbis planorbis
© Dr Roy Anderson

Map hosted by the National Biodiversity Data Centre, Waterford
To view the species profile on Biodiversity Maps and access the live map, please click on the map.


Shell a flat coil with a low, inconspicuous keel near the lower (flat) side. Last whorl about total shell breadth. Aperture nearly circular. Shell glossy but invariably covered with a matt deposit. Widespread in temporary habitats.

Key characteristics

  • Shell a medium-sized flat coil with a keel on the lower (flat) side
  • Last whorl is about total shell breadth
  • Aperture nearly circular with the keel obvious on the lower side
  • Surface glossy brown but usually covered with a matt deposit


12-17 mm.

World Distribution

Occurs across Europe to central Siberia. Distribution type: Eurosiberian Wide-temperate (64).

GBIF distribution map [open in new tab]

Irish Distribution

A hard water species which is common in temporary habitats or habitats of small size in central and southern Ireland. In Northern Ireland it is found mainly around Lough Neagh. Absent from large areas of the south-west, west and north-west and the interdrumlin fens of Cos. Down and Armagh.


  • Common in winter flooding margins of lakes and large rivers
  • Not usually in larger habitats or in permanent water bodies

Red List status

  • Least concern (lc).

Wikipedia link

Wikipedia page for Planorbis planorbis

 Anderson, R., (2016). Planorbis planorbis (Linnaeus 1758). [In] MolluscIreland. Accessed on 2024-07-12.