Species description: This freshwater snail is non-native but is now widespread around Britain and Ireland. It has an elongated shell with 7-8 whorls and dextral coiling. There are deep grooves between the whorls. The shell can be grey or dark to light brown. It is usually 4-6 mm in size, but in ideal conditions (including native habitat) it reaches up to 12 mm. It has a thin operculum and an oval aperture.

Habitat: Lakes, lagoons and estuaries. Primarily freshwater but may be found at very low salinities.

Distribution: Now widespread around Britain and Ireland.

Similar Species: Could potentially be confused with some native species of freshwater snail.

Key Identification Features:

• 7-8 whorls on elongated shell.
• Deep grooves between whorls.
• Has a thin operculum.
• Grey, light brown or dark brown.

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

iNaturalist: Potamopyrgus antipodarum at iNaturalist World Species Observations database.

WoRMS: Potamopyrgus antipodarum at World Register of Marine Species. Accepted name: Potamopyrgus antipodarum (J. E. Gray, 1843). AphiaID: 147123.

Classification: Biota; Animalia; Mollusca; Gastropoda; Caenogastropoda; Littorinimorpha; Truncatelloidea; Tateidae; Potamopyrgus