Description: A small, elongate, limpet-like shell with a sharp apex twisted to the left, found widely on the stems of emergent vegetation and macrophytes in still waters. 4-7 mm.

World Distribution: Found across Europe to western and central Siberia. Distribution type: Eurosiberian Wide Temperate (64).

Irish Distribution: Widely distributed in the central plain and northwards to Loughs Neagh and Erne but absent from large areas of the west and north.

Ecology:

• Prefers still water in lakes, pools and slow rivers
• Crawls, closely adhering, on the stems of tall marginal vegetation or submerged macrophytes
• Mainly confined to waters of moderate to high base status
• Rare exceptions include pools in acidic interdrumlin fens where it is probably relict from the earlier, lacustrine stages of fen development

Key Identification Features:

• A small, yellow-brown, limpet-like shell
• Laterally compressed and elongate with a sharp apex which is twisted to the left
• Found closely adhering to immersed plant stems in still water

Red list status:

• Least concern (lc).

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

iNaturalist: Acroloxus lacustris at iNaturalist World Species Observations database.

Thumbnails for genus Acroloxus