MolluscIreland - land and freshwater
  • Arion (Arion) rufus (Linnaeus 1758) Large red slug
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Arion (Arion) rufus
© Dr Roy Anderson
Arion (Arion) rufus
© Dr Roy Anderson
Arion (Arion) rufus
© Dr Roy Anderson

Map hosted by the National Biodiversity Data Centre, Waterford
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Arion (Arion) rufus
© Dr Roy Anderson
Arion (Arion) rufus
© Dr Roy Anderson

A large roundback slug similar to Arion ater but with slightly brighter colouration, a much brighter foot fringe and sole and a less strong rocking response. Juveniles possess distinct lateral bands. Found in drier, warmer places, including gardens.

Key characteristics

  • A large roundback slug varying in colour from whitish through orange and browns to black, with the sides of the body below the mantle pale in darker specimens
  • Foot fringe always a rich orange to carmine-red, often contrasting with a darker upper body
  • Sole paler than the upper body and usually with an orange flush near the head end; in dark specimens strong lineolations radiating inwards from the sides, are present
  • Juveniles are pale grey-brown with dark brown to black bands edged above with pale reddish or yellow
  • Rocking response is muted, and sometimes not exhibited at all
  • Reproduction is mainly sexual; copulating individuals should be looked for in late July or August


70-140 mm.

World Distribution

True range is uncertain due to confusion with related species. Probably only occurs in the extreme coastal fringes of Europe. Distribution type: Oceanic Temperate (71).

GBIF distribution map [open in new tab]

Irish Distribution

Widespread in gardens in the east. In the west more in natural habitats near the sea.


  • Probably common in gardens in the main urban centres of the east, but much under-recorded
  • Elsewhere, on dry coastal habitats such as dunes and heathy hill slopes
  • Recorded from several western islands
  • Not known to eat or damage green vegetable material but its presence in gardens will alert suspicions to that effect


British and Irish A. rufus have been well characterized by Quick (1960) and are probably distinct from the 'red slug' of Continental authors (e.g. Chevallier, 1981).

Red List status

  • Least concern (lc).

Wikipedia link

Wikipedia page for Arion rufus

 Anderson, R., (2016). Arion (Arion) rufus (Linnaeus 1758). [In] MolluscIreland. Accessed on 2024-07-13.