Arionidae Gray, 1840

Languages: English



The center of diversity for the family is the western Palearctic, especially the Iberian peninsula (Wiktor 1996).

About 35 species are in the genera Arion, Geomalacus, and Letourneuxia (Barker & Efford 2004).

Author(s): Paustian, Megan
Rights holder(s): Paustian, Megan



External:  Plain or striped body; mantle lies on the anterior part of the body; pneumostome anterior to midpoint on right side of mantle; granular skin on mantle; round tail with caudal pit at tip, no keel;  wide foot fringe; sole one part.

Internal:  Internal shell small and plate-like or just vestigial calcareous granules; Jaw odontognathic, ribbed; radular teeth: central tricuspid, lateral bi- or tricuspid, marginal bicuspid, all having broad bases, teeth often accreted; heart, in relation to body axis, is titled to the left; Kidney circular (surrounding aorta); cephalic retractors tend to divide into separate branches attached independently to the posterior part of pallial complex; 2-loop digestive system; male copulatory organs generally reduced, their role being taken over by a well-developed atrium and epiphallus that produces spermatophores; thus, no penis, just long epiphallus; no vagina; ligula in atrium or end of oviduct (Wiktor 2001).

Author(s): Paustian, Megan; (F. Welter Schultes)
Rights holder(s): Paustian, Megan; (F. Welter Schultes)


Up to 250 mm long, but usually much shorter.

Author(s): (F. Welter Schultes)
Rights holder(s): (F. Welter Schultes)

Ecology and Distribution


Native throughout Europe and north to Scandinavia, N Africa down to the Sahara, with some species in Asia east to the Urals (and Siberia); major speciation center in Iberian Peninsula (De Winter 1986; Wiktor et al. 2000); not in the Caucasus or Black Sea region (Wiktor 1983).

Author(s): Paustian, Megan
Rights holder(s): Paustian, Megan


For its defense, an arionid slug will retract its head, become hemispherical, and stick down to the substrate. Many Arion species have extra colored pigment as a deterent in the slime that they produce when perturbed (Rollo & Wellington 1979).

Author(s): Paustian, Megan
Rights holder(s): Paustian, Megan

Trophic Strategy

Consumes plant, fungus and sometimes feces, carrion (Herbert 1997).

Author(s): Paustian, Megan
Rights holder(s): Paustian, Megan


Barker, GM., & Efford MG. (2004).  Predatory gastropods as natural enemies of terrestrial gastropods and other invertebrates. (Barker G., Ed.).Natural Enemies of Terrestrial Molluscs. 279-403. Cambridge, MA: CABI Publishing.
Castillejo, J. (1997).  Las babosas de la familia Arionidae Gray, 1840 en la Península Ibérica e Islas Baleares. Morfología y distribución (Gastropoda, Pulmonata, Terrestria Nuda). Rev. Real Acad. Gal. Cien.. 16, 51-118.
d'Audebard de Férussac, A. E. J. P. J., & Deshayes G. - P. (Submitted).  Histoire naturelle générale et particulière des mollusques terrestres et fluviatiles, tant des espèces que l'on trouve aujourd'hui vivantes, que des dépouilles fossiles de celles qui n'existent plus; classés d'après les caractères essentiels que présenten. Tome 1: 8 + 184 pp.; Tome 2 (1): 402 pp.; 2 (2): 260 + 22 + 16 pp.; Atlas 1: 70 pl.; Atlas 2: 166 + 5 pl.
Herbert, DG. (1997).  The terrestrial slugs of KwaZulu-Natal: diversity, biogeography and conservation. Ann. Natal Mus.. 38, 197-239.
Pilsbry, HA. (1948).  Land Mollusca of North America north of Mexico. The Academy of Natural Sciences of Philadelphia Monograph. 3, 748-770.
Quick, HE. (1960).  British slugs (Pulmonata: Testacellidae, Arionidae, Limacidae). Bulletin of the British Museum (Natural History), Zoology. 6, 103-226.
Schultes, W. F. (2010).  Arion.
Wiktor, A. (1983).  The slugs of Bulgaria (Arionidae, Milacidae, Limacidae, Agriolimacidae - Gastropoda, Stylommatophora). Annales Zoologici. 37(3), 71-205.
Wiktor, A. (2001).  Fauna Graeciae VIII: The slugs of Greece (Arionidae, Milacidae, Limacidae, Agriolimacidae - Gastropoda, Stylommatophora). Irakleio: Natural History Museum of Crete, University of Crete.
Wiktor, A., & Parejo C. (1989).  Arion (Kobeltia) paularensis sp. n. from Central Spain (Gastropoda, Pulmonata: Arionidae). Malakologische Abhandlungen. 14(4), 27-33.
Wiktor, A., Chen DN., & Wu M. (2000).  Stylommatophoran slugs of China (Gastropoda: Pulmonata) – Prodromus. Folia Malacologia. 8(1), 3-35.