Description: A 'keeled' roundback slug, grey or brown on the back with darker spots, thin lateral bands, grey sides below the bands and white sole. The 'keel' consists of a line of tubercles on the back i.e. not a real keel. Widespread in woodland. 30-38 mm.

World Distribution: Mainly middle and northern latitudes in Europe. Distribution type: European Temperate (73).

Irish Distribution: Widespread and locally common.

Ecology:

• A characteristic species of leaf litter and dead wood in woodlands
• Can occur in open woodland with Arion silvaticus
• Also found occasionally in gardens but not on agricultural land
• More localised and less common towards the west

Key Identification Features:

• A roundback slug with grey back flecked with darker grey, thin lateral bands, and grey sides with white sole
• The 'keel' consists of pale, raised tubercles along the back; these are evident in both adults and young, but more conspicuous in the young
• Mucus sticky, clinging, colourless to yellowish
• Contracts to a bell shape

Red list status:

• Least concern (lc).

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

iNaturalist: Arion circumscriptus circumscriptus at iNaturalist World Species Observations database.

GBIF data for Arion fasciatus | Classification: Gastropoda, Stylommatophora, Arionidae, Arion

Thumbnails for genus Arion