MolluscIreland - land and freshwater
  • Tandonia rustica (Millet 1843)
Click on the thumbnails to enlarge the images
Tandonia rustica
© Dr Roy Anderson
Tandonia rustica
© Dr Roy Anderson
Tandonia rustica
© Dr Roy Anderson

Map hosted by the National Biodiversity Data Centre, Waterford
To view the species profile on Biodiversity Maps and access the live map, please click on the map.


A large keeled slug with a characteristic warm buff to grayish-buff ground colour conspicuously spotted with brown or black. Respiratory pore with a pale rim and mantle with two thin dark lateral bands. Keel yellowish to white. Sole pale, mucus colourless. Very rare.

Key characteristics

  • A large keeled slug with a characteristic warm body colour
  • Body a warm buff to greyish-buff speckled with brown to black spots and with two thin lateral bands on the mantle
  • Breathing pore with a pale rim
  • Keel yellowish to white
  • Mucus colourless, moderately sticky
  • Mantle granular with deep but inconspicuous horseshoe-shaped groove


70-100 mm.

World Distribution

This species may have originated in south-east Europe and spread by human agency north-west to the British Isles, like several other slug species. However, it is difficult to rule it out as a native. Distribution type: European Southern-temperate (83).

GBIF distribution map [open in new tab]

Irish Distribution

Stelfox (1911a) refers to spotted keeled slugs having been found near Blarney and Aghada in East Cork. Dissection was not performed on these and the records remained unconfirmed until Cawley (1996b) discovered the present species on roadsides near Blarney. More recently Pascal Sweeney (pers. comm.) has reported a live specimen from woods at Rostellan 3 km from Stelfox's Aghada site.


  • Usually found concealed in the lower layers of deep beech or oak leaf litter
  • Also occurs under dead wood and deeply embedded stones but always in shaded woodland environments on shallow soils over limestone
  • The scarcity of higher plants in these places suggests a diet of leaf litter, spiced seasonally with fungi or dead animal remains
  • Eggs have been produced in captivity in the autumn but the timing of reproduction in the wild is uncertain

Red List status

  • Vulnerable (VU).

Wikipedia link

Wikipedia page for Tandonia rustica

 Anderson, R., (2016). Tandonia rustica (Millet 1843). [In] MolluscIreland. Accessed on 2024-03-02.