''Arion hortensis'', also known by its common name the "garden slug", "small striped slug" or "black field slug" is a

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

of small air-breathing land slug, a

terrestrial Terrestrial refers to things related to land or the planet Earth. Terrestrial may also refer to: * Terrestrial animal, an animal that lives on land opposed to living in water, or sometimes an animal that lives on or near the ground, as opposed to ...

pulmonate gastropod

mollusk Mollusca is the second-largest phylum of invertebrate animals after the Arthropoda, the members of which are known as molluscs or mollusks (). Around 85,000 extant species of molluscs are recognized. The number of fossil species is e ...

in the

family Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Idea ...

Arionidae, the roundback slugs. In Britain, the name ''Arion hortensis'' was previously applied to a species complex, consisting of this species plus ''

Arion distinctus ''Arion distinctus'' is a species of air-breathing land slug in the family Arionidae, sometimes known as the roundback slugs. It is a terrestrial pulmonate gastropod mollusc. Several vernacular names exist, but it is unclear if they are much ...

'' Mabille, 1868 and '' Arion owneii'' Davies, 1979. Here the name is used '' sensu stricto''.

Description

It is worth noting that with slugs it is often difficult to establish good criteria for identifying species using external features or internal features, as colouration can be quite variable, and the rather plastic anatomy makes diagnostic anatomical features difficult to establish. See the article on ''

'' for characters distinguishing that from this species. The clearest character is the structure at the entrance to the

epiphallus The reproductive system of gastropods (slugs and snails) varies greatly from one group to another within this very large and diverse taxonomic class of animals. Their reproductive strategies also vary greatly, see Mating of gastropods. In many mar ...

. A 30–40 mm. long (exceptionally up to 50 mm) roundback slug. In colour it is grey to bluish black, with dark lateral bands (the right band usually running entirely above the pneumostome). The tentacles are bluish or reddish, and the slug bluish or orange tip at the tail. The first row of tubercles above the foot-fringe is white. The contracted body is semicircular (not bell-shaped) in transverse section. The sole is orange or yellow. The body mucus is yellow-orange. Juveniles are bluish grey with a darker dorsum and a yellow sole.

Distribution

This species is native to

Europe Europe is a large peninsula conventionally considered a continent in its own right because of its great physical size and the weight of its history and traditions. Europe is also considered a subcontinent of Eurasia and it is located entirel ...

an countries and islands including: *

Great Britain Great Britain is an island in the North Atlantic Ocean off the northwest coast of continental Europe. With an area of , it is the largest of the British Isles, the largest European island and the ninth-largest island in the world. It i ...

Ireland Ireland ( ; ga, Éire ; Ulster Scots dialect, Ulster-Scots: ) is an island in the Atlantic Ocean, North Atlantic Ocean, in Northwestern Europe, north-western Europe. It is separated from Great Britain to its east by the North Channel (Grea ...

* and other areas It has been introduced various other countries including to

Tasmania ) , nickname = , image_map = Tasmania in Australia.svg , map_caption = Location of Tasmania in AustraliaCoordinates: , subdivision_type = Country , subdi ...

Ecology

This slug lives in

garden A garden is a planned space, usually outdoors, set aside for the cultivation, display, and enjoyment of plants and other forms of nature. The single feature identifying even the wildest wild garden is ''control''. The garden can incorporate bot ...

fields Fields may refer to: Music * Fields (band), an indie rock band formed in 2006 * Fields (progressive rock band), a progressive rock band formed in 1971 * ''Fields'' (album), an LP by Swedish-based indie rock band Junip (2010) * "Fields", a song b ...

pasture Pasture (from the Latin ''pastus'', past participle of ''pascere'', "to feed") is land used for grazing. Pasture lands in the narrow sense are enclosed tracts of farmland, grazed by domesticated livestock, such as horses, cattle, sheep, or sw ...

s and similar habitat. This slug serves as an intermediary host for '' Muellerius capillaris''.

References

External links

''Arion hortensis''
at

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taxonomy, short description, distribution, biology, status (threats), images
''Arion hortensis''
images at

Encyclopedia of Life The ''Encyclopedia of Life'' (''EOL'') is a free, online encyclopedia intended to document all of the 1.9 million living species known to science. It is compiled from existing trusted databases curated by experts and with the assistance of ...

Description and life habits
Arion (gastropod) Gastropods described in 1819 Gastropods of Europe {{Arionidae-stub