MolluscIreland - land and freshwater
  • Limacus flavus (Linnaeus 1758) Yellow slug
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Limacus flavus
© Dr Roy Anderson
Limacus flavus
© Dr Roy Anderson

Map hosted by the National Biodiversity Data Centre, Waterford
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A medium to large slug with a yellowish-green ground colour overlaid with greyish or grey-green spotting. Very similar to L. maculatus but differs in its paler colouration with less green overall and a distinct yellow keel. An early introduction from the Mediterranean but now dying out in Ireland.

Key characteristics

  • A medium to large yellow-green or yellow-grey or brownish slug
  • Ground colour overlaid with grey to grey-green spots, these mostly small in contradistinction to the large blotches of L. maculatus - tentacles bluish
  • Keel short and invariably yellow
  • Mucus yellowish, moderately watery
  • Breathing pore towards the rear of the mantle
  • Juveniles similar in colour to adults (pale)


80-130 mm.

World Distribution

Its natural range is difficult to determine but is probably west Mediterranean. Spread by man to many parts of the world, including the British Isles.

GBIF distribution map [open in new tab]

Irish Distribution

Formerly widespread in the vicinity of larger conurbations but rare in later years and there are very few recent records. It may be suffering unequal competition from Limax maculatus which now infests suitable urban habitats. Recent records in Ireland include gardens in Coleraine Co. Londonderry (Cook & Radford, 1988), the Tropical Ravine in Belfast Botanic Gardens and a stable yard at Belvedere in the Lagan Valley, Co. Down. The Tropical Ravine record dates from 1975 but the species has not been seen there in recent years and only L. maculatus can be found there now.


  • Incompletely naturalized and occurs only in outhouses and cellars in close proximity to man

Red List status

  • Not applicable.

Wikipedia link

Wikipedia page for Limacus flavus

 Anderson, R., (2016). Limacus flavus (Linnaeus 1758). [In] MolluscIreland. Accessed on 2024-06-24.