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.

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. The color of an individual can be influenced by its diet.

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. Arion slugs are often transported internationally in shipments of plant products and mushrooms. 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.

Species
There are approximately 40 species in the genus.

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 ) – hedgehog slug
 * Arion lusitanicus Mabille, 1868
 * Arion obesoductus (syn. Arion alpinus auctt. non Pollonera, 1887 )
 * 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
 * Arion vulgaris Moquin-Tandon, 1855 (syn. Arion lusitanicus auct. non Mabille ) – Spanish slug

Also included

 * Arion vejdorskyi, a taxon with unclear taxonomic position

Etymology
The name Arion is from Neo-Latin, from the Greek areíones, a “kind of snail or slug.”