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).
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).
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).
Up to 250 mm long, but usually much shorter.
Consumes plant, fungus and sometimes feces, carrion (Herbert 1997).
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).
Molecular Biology and Genetics
Statistics of barcoding coverage
Specimens with Sequences:541
Specimens with Barcodes:477
Species With Barcodes:52
Unlike some slugs, European Arionidae have no internal shell. They also have no keel on the back. The caudal mucous pit is above the tip of the tail. The respiratory pore (pneumostome) is in front of the midpoint of the mantle. The body length is up to 250 mm. Mantle covers only a part of the body and lies in the anterior part.
The jaw is odontognathic, which means it is transversally ribbed. Radular teeth include: central tricuspid, lateral bi- or tricuspid, marginal bicuspid, all having broad bases. Teeth are often accreted. The digestive system forms 2 loops. The heart, in relation to body axis, is titled to the left. The kidney is circular (surrounding aorta). Cephalic retractors tend to divide into separate branches attached independently to the posterior part of pallial complex. The shell is strongly reduced in places, most often completely buried in the mantle, usually of loose crystals or plate-like. Genitalia: the penis is present only in some species, epiphallus is present in nearly all of them. Male copulatory organs are generally reduced, their role being taken over by a well-developed atrium and the epiphallus that produces spermatophores.
Family Arionidae has no subfamilies according to the taxonomy of the Gastropoda by Bouchet & Rocroi, 2005.
Genera within the family Arionidae include:
- Anadenulus Cockerell, 1890
- Ariolimax Mörch, 1859 - Banana slug
- Arion Férussac, 1819
- Ariunculus Lessona, 1881
- Carinacauda Leonard, Chichester, Richart & Young, 2011
- Geomalacus Allman, 1843
- Gliabates Webb, 1959
- Hemphillia Bland & Binney, 1872
- Hesperarion Simroth, 1891
- Letourneuxia Bourguignat, 1866
- Magnipelta Pilsbry, 1953
- Prophysaon Bland & W. G. Binney, 1873
- Securicauda Leonard, Chichester, Richart & Young, 2011
- Udosarx Webb, 1959
- Zacoleus Pilsbry, 1903
The parasites of the Arionidae slugs include the Sciomyzidae.
This article incorporates public domain text from the reference.
- "Family summary for Arionidae". AnimalBase, last change 12-06-2009, accessed 4 August 2010.
- Barker G. M.: Gastropods on Land: Phylogeny, Diversity and Adaptive Morphology. in Barker G. M. (ed.): The biology of terrestrial molluscs. CABI Publishing, Oxon, UK, 2001, ISBN 0-85199-318-4. 1-146, cited pages: 139 and 142. (In the reference specified as Ariononae.)
- Cockerell (1890). Ann. Mag. nat. Hist. (6)6: 278.
- Leonard; Chichester, Richart & Young (2011). "Securicauda hermani and Carinacauda stormi, two new genera and species of slug from the Pacific Northwest of the United States (Gastropoda: Stylommatophora: Arionidae), with notes on Gliabates oregonius Webb 1959". Zootaxa 2746: 43–56.
- Webb (1959). Gastropodia 1(3): 22.
- Bland T.[disambiguation needed] & Binney W. G. (1874). "Description of Hemphillia, a new Genus of Terrestrial Mollusks". Annals of the Lyceum of Natural History of New York. 10: 208-211. Plate 9.
- Simroth (1891). Malak. Bl. (N.S.) 11: 111.
- Pilsbry H. A. (1953). Nautilus 67: 37.
- Bland & Binney W. G. (1873). Ann. Lyceum nat. Hist. N. York 10(3): 921.
- Webb (1959). Gastropodia 1: 22.
- Pilsbry H. A. (1903). Proc. Acad. nat. Sci. Philad. 55: 626.
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