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Helicidae

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Helicidae
Helix pomatia
Scientific classification
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Helicidae

Subfamilies

Ariantinae
Helicinae

The Helicidae, sometimes known as the typical snails, are a taxonomic family of small to large, air-breathing, land snails. In other words, they are terrestrial pulmonate gastropod mollusks.

Several species in this family are edible, including Helix aspersa the garden snail, and Helix pomatia the "escargot".[1] The biology of these two species in particular has been much studied.

Anatomy

This family of snails is defined by the anatomical presence of a diverticulum. Some genera within this family create and use love darts as part of their mating behavior. These snails have one dart apparatus. The dart sac has no accessory sac, and contains two tubular glands, inserted at the base of the dart sac.

In this family, the number of haploid chromosomes varies from 21 to 30 (according to the values in this table).[2]

Helicid snails for sale in Italy.

Distribution

The family is native to Eurasia and belongs the Western Palearctic group..

However some of the species, such as for example Helix aspersa, have been introduced and become established in numerous different places worldwide.

Many accidental introductions happen because the eggs of most Helicidae are laid in the soil, and they may thus easily travel unnoticed along with landscaping plants.

Shell description

The shells of these snails are mostly rather globular in shape. In some genera, such as Cepaea, the shells are brightly colored and patterned.

Genera

Arianta arbustorum
Iberus gualterianus alonensis

Subfamilies and genera within the family Helicidae include:

After Fauna Europaea[3] and Taxonomy Browser[4] the family Helicidae includes the following subfamilies, tribus and genera:

Subfamily Ariantinae Mörch, 1864 - in this subfamily the glands are divided or undivided. The love darts contain tow to four blades. There is only one penial papilla.

Arianta Turton, 1831
Causa
Chilostoma Fitzinger, 1833
Cylindrus Fitzinger, 1833
Drobacia
Faustina
Helicigona A. Férussac, 1821
Isognomostoma Fitzinger, 1833
Vidovicia

Subfamily Helicinae Rafinesque, 1815  : In this subfamily the glands are divided. The love dart has four blades or vanes.There are two penial papillae.

  • Tribe Thebini Wenz, 1923 (the synonym Euparyphinae Perrot, 1939 has been declared an invalid name)
Theba Risso, 1826 - Theba pisana (O. F. Müller, 1774)
Allognathus
Assyriella
Cantareus Risso, 1826
Cepaea Held, 1838
Codringtonia
Cornu Born, 1778
Eobania P. Hesse, 1913
Helix Linnaeus, 1758
Hemicycla
Iberus
Idiomela T. Cockerell, 1921
Lampadia
Leptaxis
Levantina
Otala Schumacher, 1817
Pseudotachea
Tyrrhenaria
Macularia
Marmorana W. Hartmann, 1844 This genus might actually belong to the subfamily Ariantinae and not to the subfamily Helicinae, as has been assumed until now [5]
Tacheocampylaea
Tyrrheniberus

References

  1. ^ M.P. Kerney & R.A.D. Cameron. 1979. A field guide to the land snails of Britain and northwestern Europe. Collins, London.
  2. ^ 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.
  3. ^ Fauna Europaea
  4. ^ Taxonomy Browser
  5. ^ Hartmut Nordsieck. April 2006. Higher classification of Helicoidea and the molecular analyses of their phylogeny.