Arion (gastropod)

Arion is a genus of air-breathing land slugs in the family Arionidae, the roundback slugs. Most species of this Palearctic genus are native to the Iberian Peninsula.^[2]

Arion
Arion rufus
Scientific classification
Kingdom:	Animalia
Phylum:	Mollusca
Class:	Gastropoda
Order:	Stylommatophora
Family:	Arionidae
Genus:	Arion A. Férussac, 1819[1]
Type species
Arion empiricorum A. Férussac, 1819

Species can be difficult to distinguish from one another upon cursory examination, because individuals of a species can vary in color and there are few obvious differences between taxa.^[3] The color of an individual can be influenced by its diet.^[4]

Some Arion are known as pests, such as A. lusitanicus auct. non Mabille (= A. vulgaris), which damages agricultural crops and ornamental plants, and A. rufus, a familiar garden pest.^[5] Arion slugs are often transported internationally in shipments of plant products and mushrooms.^[6] Arion slugs have been identified in North America and Australia as invasive species, altering the plants of ecosystems through seed predation and competing with native slugs.^[7]

Species

There are approximately 40 species in the genus.^[4][8]

Species include:

• Arion ater (Linnaeus, 1758) – black slug
• Arion circumscriptus Johnston, 1828 – brown-banded arion
• Arion distinctus Mabille, 1868 – darkface arion
• Arion fasciatus (Nilsson, 1823) – orange-banded arion
• Arion flagellus Collinge, 1893
• Arion fuscus (O.F.Müller, 1774)
• Arion hortensis Férussac, 1819 – small striped slug
• Arion intermedius Normand, 1852 (syn. Arion alpinus Pollonera, 1887^[9]) – hedgehog slug
• Arion lusitanicus Mabille, 1868
• Arion obesoductus (syn. Arion alpinus auctt. non Pollonera, 1887^[9])
• Arion occultus R.Anderson, 2004
• Arion owenii Davies, 1979 – warty arion
• Arion rufus (Linnaeus, 1758) – red slug
• Arion silvaticus Lohmander, 1937 – forest arion
• Arion simrothi Künkel, 1909
• Arion subfuscus (Draparnaud, 1805) – dusky arion
• Arion transsylvanus Simroth, 1885^[10]
• Arion vulgaris Moquin-Tandon, 1855 (not synonymous to Arion lusitanicus auct. non Mabille) – Spanish slug
• Arion lusitanicus Rowson, B. (2017) - Portuguese slug

Also included

• Arion vejdorskyi, a taxon with unclear taxonomic position

Etymology

The name Arion is in reference to Aelion's De Natura Animalium, which features a story about areíones - snails which leave their shells behind to feed, thus outsmarting predators who attack the empty shells.^[11][12]