MolluscIreland - land and freshwater
  • Ancylus fluviatilis O. F. Müller 1774 River limpet
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Ancylus fluviatilis
© Dr Roy Anderson
Ancylus fluviatilis
© Dr Roy Anderson
Ancylus fluviatilis
© Dr Roy Anderson

Map hosted by the National Biodiversity Data Centre, Waterford
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A small limpet-like, conical shell with a backwardly-directed curved apex. Very common and widespread in flowing water.

Key characteristics

  • A small, limpet-like shell with a conical, backwardly directed apex
  • Shell with fine growth lines but lacking other ormament and fairly dull, pale brown
  • Animal grey


5-8 mm.

World Distribution

In Europe only absent from areas where flowing water is likely to freeze in winter, therefore not in central or northern Scandinavia. Distribution type probably Eurosiberian Southern-temperate (84), but the de-limitation of various southern and eastern forms which may be given independent species status is poorly known.

GBIF distribution map [open in new tab]

Irish Distribution

Abundant throughout except in polluted streams and rivers.


  • A bottom living species ubiquitous in unpolluted running water of all kinds where it adheres to the sides of stones in moderate flows
  • Also lives on stones in the wave zone of lakes
  • Sensitive to pollution but is usually excluded from suitable habitat only by chronic pollution as it will normally recolonize lost territory after point-source incidents (Anderson, 1977).

Red List status

  • Least concern (lc).

Wikipedia link

Wikipedia page for Ancylus fluviatilis

 Anderson, R., (2016). Ancylus fluviatilis O. F. Müller 1774. [In] MolluscIreland. Accessed on 2024-03-03.