MolluscIreland - land and freshwater
  • Limacus maculatus (Kaleniczenko 1851) Irish yellow slug
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Limacus maculatus
© Dr Roy Anderson
Limacus maculatus
© Dr Roy Anderson
Limacus maculatus
© Dr Roy Anderson

Map hosted by the National Biodiversity Data Centre, Waterford
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A medium to large slug with pale greenish-grey body overlaid with large irregular dark green markings. Keel very short, sole whitish or yellowish. Mucus pale yellow to deep orange. Tentacles grey to bluish. A common variant has the dark mottling broken up into fine spots which create a spotted appearance rather similar to that of Limacus flavus. A late introduction from south-east Europe, now widespread and common.

Key characteristics

  • A medium to large blotched green slug
  • Ground colour greenish-grey with more or less of an orange tinge, overlaid by large dark green blotches or patterned with an array of small, dark mixed with pale, spots - mantle generally green, unspotted
  • Mucus yellowish to deep orange
  • Tentacles grey to bluish-grey
  • Keel short and the same colour as the rest of the back
  • Juveniles very dark green with slightly paler blotches


80-130 mm.

World Distribution

Probably native only to south-eastern Europe (Wiktor & Norris, 1982; Wiktor, 2001) and an introduction in the British Isles.

GBIF distribution map [open in new tab]

Irish Distribution

In Britain this is still a local and synanthropic species whereas in Ireland, though common in towns and gardens, it is also widespread in the general landscape. There has been a perceptible increase in abundance in recent decades with urban habitats seeing a particularly dramatic change.


  • Has a strong association with rotting wood in natural habitats where it may feed on wood rot fungi
  • In anthropic situations maculatus will enter dwellings and damp outhouses where it has been observed scavenging, among other things, on food laid out for pets or on damp wall-paper
  • Cook & Radford (1988) found a substantial percentage of saxicolous lichen in the gut contents of specimens living in the vicinity of walls at Coleraine, Co Londonderry


In the nineteen-seventies it became clear that a taxon found in Irish woods was anatomically distinct from the strongly anthropic flavus and after some confusion and the application of several names (grossui Lupu, hibernicus nom.nud.) it was described new to science from Irish material under the name pseudoflavus (Evans, 1978a). This name was shortly replaced by maculatus (Kaleniczenko), a name identified with an eastern European taxon (Wiktor & Norris, 1982). The natural range of this species is imperfectly known but includes Romania, Bulgaria, Turkey and western Russia. Some authors prefer to place this species in Limax in which case the specific name should be ecarinatus Boettger.

Red List status

  • Not applicable.

Wikipedia link

Wikipedia page for Limacus maculatus

 Anderson, R., (2016). Limacus maculatus (Kaleniczenko 1851). [In] MolluscIreland. Accessed on 2024-03-02.