Description: A small, yellow-brown, sinistral shell with short, blunt spire. Shell slippery and highly polished. The animal is grey and outgrowths of the mantle partly cover the shell. These have finger-like lobes or digitations. Widespread and common. 8-12 mm.

World Distribution: This species has a wide distribution in the western Palaearctic, but like Aplexa hypnorum, confusion with allied forms makes the eastern limits of its distribution uncertain. The range is probably Eurasian Boreo-temperate (55). Several "species" found in North America may be conspecific in which case the range could be Circumpolar Boreo-temperate.

Irish Distribution: Widespread throughout Ireland but sparser in the west and north.

Ecology:

• A fragile but active species usually of clear, weedy and slow-flowing or stagnant waters such as canals, slow rivers and moderate-sized lakes, or the sheltered margins of larger lakes
• Tolerant of moderate eutrophication
• The effect of incursions by alien Physidae has not been assessed but Kerney (1999) observed little effect upon populations in Britain, except at organically polluted sites

Key Identification Features:

• A small, sinistral, yellow-brown shell
• Spire short and blunt
• Animal dark grey with finger-like lobes or digitations of the mantle partly covering the shell in life
• Shell fragile, polished and slippery

Red list status:

• Least concern (lc).

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

iNaturalist: Physa fontinalis at iNaturalist World Species Observations database.

GBIF data for Physa fontinalis | Classification: Gastropoda, incertae sedis, Physidae, Physa

Thumbnails for genus Physa