''Arion fuscus'', also known as the "dusky arion", 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 Slug, or land slug, is a common name for any apparently shell-less terrestrial gastropod mollusc. The word ''slug'' is also often used as part of the common name of any gastropod mollusc that has no shell, a very reduced shell, or only a smal ...

, 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 Pulmonata or pulmonates, is an informal group (previously an order, and before that a subclass) of snails and slugs characterized by the ability to breathe air, by virtue of having a pallial lung instead of a gill, or gills. The group includ ...

gastropod The gastropods (), commonly known as snails and slugs, belong to a large taxonomic class of invertebrates within the phylum Mollusca called Gastropoda (). This class comprises snails and slugs from saltwater, from freshwater, and from land. T ...

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 Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its ...

Arionidae Arionidae, common name the "roundback slugs" or "round back slugs" are a taxonomic family of air-breathing land slugs, terrestrial pulmonate gastropod mollusks in the superfamily Arionoidea. Distribution The distribution of this family of slug ...

, the roundback slugs. ''Arion subfuscus'' (Draparnaud, 1805) is considered by some authors to be a partial

synonym A synonym is a word, morpheme, or phrase that means exactly or nearly the same as another word, morpheme, or phrase in a given language. For example, in the English language, the words ''begin'', ''start'', ''commence'', and ''initiate'' are all ...

for ''Arion fuscus''. ''Arion subfuscus'' (Draparnaud, 1805) and ''A. fuscus'' (Müller, 1774) have very similar morphology and have overlapping distributional ranges in northwestern Europe. ''Arion fuscus'' is widespread throughout Central, North and East Europe whereas ''A. subfuscus'' is restricted to West Europe. (For practical purposes the two are synonyms in Germany and in the Czech Republic.) The two taxa are referred to as the

species complex In biology, a species complex is a group of closely related organisms that are so similar in appearance and other features that the boundaries between them are often unclear. The taxa in the complex may be able to hybridize readily with each oth ...

''Arion subfuscus''/''fuscus'' both members having several evolutionary lineages. They are only separable by

alloenzyme Alloenzymes (or also called allozymes) are variant forms of an enzyme which differ structurally but not functionally from other allozymes coded for by different alleles at the same locus. These are opposed to isozymes, which are enzymes that perfo ...

analysis and gonad type.

Description

A 50–70 mm roundback slug. It is brown in colour, ranging from black-brown through olive-brown to orange and bright reddish-orange. Darker lateral bands are present. Dark pigment reaches under the pneumostome from back to front. The foot fringe is pale with thin lines. The sole is uniformly pale/translucent.The tentacles are pale or dark. It does not contract into a bell shape when stimulated. The Dusky Arion differs from other ''Arion'' species in its yellow-orange body mucus. Genitalia:Atrium about half diameter of spermatheca, spermatheca spherical, oviduct large and swollen like in ''

Arion lusitanicus ''Arion lusitanicus'', also known by its common name Portuguese slug, is a species of air-breathing land slug, a terrestrial pulmonate gastropod mollusk in the family Arionidae. Distribution ''Arion lusitanicus'' is endemic to forests of the ...

Distribution

This species occurs in

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 Continent#Subcontinents, subcontinent of Eurasia ...

an and

Asia Asia (, ) is one of the world's most notable geographical regions, which is either considered a continent in its own right or a subcontinent of Eurasia, which shares the continental landmass of Afro-Eurasia with Africa. Asia covers an area ...

n countries and islands including: *

Austria Austria, , bar, Östareich officially the Republic of Austria, is a country in the southern part of Central Europe, lying in the Eastern Alps. It is a federation of nine states, one of which is the capital, Vienna, the most populous ...

Bulgaria Bulgaria (; bg, България, Bǎlgariya), officially the Republic of Bulgaria,, ) is a country in Southeast Europe. It is situated on the eastern flank of the Balkans, and is bordered by Romania to the north, Serbia and North Macedon ...

Czech Republic The Czech Republic, or simply Czechia, is a landlocked country in Central Europe. Historically known as Bohemia, it is bordered by Austria to the south, Germany to the west, Poland to the northeast, and Slovakia to the southeast. The ...

- least concern (LC) *

Germany Germany,, officially the Federal Republic of Germany, is a country in Central Europe. It is the second most populous country in Europe after Russia, and the most populous member state of the European Union. Germany is situated betwe ...

Netherlands ) , anthem = ( en, "William of Nassau") , image_map = , map_caption = , subdivision_type = Sovereign state , subdivision_name = Kingdom of the Netherlands , established_title = Before independence , established_date = Spanish Netherl ...

Arion subfuscus — Anemoon
/ref> *

Poland Poland, officially the Republic of Poland, is a country in Central Europe. It is divided into 16 administrative provinces called voivodeships, covering an area of . Poland has a population of over 38 million and is the fifth-most populous ...

Slovakia Slovakia (; sk, Slovensko ), officially the Slovak Republic ( sk, Slovenská republika, links=no ), is a landlocked country in Central Europe. It is bordered by Poland to the north, Ukraine to the east, Hungary to the south, Austria to the s ...

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 is ...

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 ...

China China, officially the People's Republic of China (PRC), is a country in East Asia. It is the world's most populous country, with a population exceeding 1.4 billion, slightly ahead of India. China spans the equivalent of five time zones and ...

Wiktor A., De-niu C. & Wu M. (2000). "Stylommatophoran slugs of China (Gastropoda: Pulmonata) – prodromus". ''Folia Malacologica'' 8(1): 3-35. * and other areas

Habitat

This slug lives under fallen logs and under bark in

woodland A woodland () is, in the broad sense, land covered with trees, or in a narrow sense, synonymous with wood (or in the U.S., the ''plurale tantum'' woods), a low-density forest forming open habitats with plenty of sunlight and limited shade (see ...

areas, but it also lives in hedges,

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 both ...

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 swine ...

s and

dune A dune is a landform composed of wind- or water-driven sand. It typically takes the form of a mound, ridge, or hill. An area with dunes is called a dune system or a dune complex. A large dune complex is called a dune field, while broad, f ...

References

External links

''Arion subfuscus''
at

Animalbase AnimalBase is a project brought to life in 2004 and is maintained by the University of Göttingen, Germany. The goal of the AnimalBase project is to digitize early zoological literature, provide copyright-free open access to zoological works, and pr ...

taxonomy,short description, distribution, biology,status (threats), images
''Arion subfuscus''
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 non ...

Arion (gastropod) Gastropods of Europe Gastropods of Asia Fauna of England Gastropods described in 1774 Taxa named by Otto Friedrich Müller {{Arionidae-stub

Description

Distribution

Habitat

References

Further reading

External links