Helicidae is a large, diverse

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. Ideal ...

of small to large, air-breathing

land snail A land snail is any of the numerous species of snail that live on land, as opposed to the sea snails and freshwater snails. ''Land snail'' is the common name for terrestrial gastropod mollusks that have shells (those without shells are kn ...

s, sometimes called the "typical snails." A number of species in this family are valued as food items, including ''

Cornu aspersum ''Cornu aspersum'' (syn. ''Cryptomphalus aspersus''), known by the common name garden snail, is a species of land snail in the family Helicidae, which includes some of the most familiar land snails. Of all terrestrial molluscs, this species may ...

'' (formerly ''Helix aspersa'') the brown or garden snail, and ''

Helix pomatia ''Helix pomatia'', common names the Roman snail, Burgundy snail, or escargot, is a species of large, edible, air-breathing land snail, a pulmonate gastropod terrestrial mollusc in the family Helicidae.MolluscaBase eds. (2021). MolluscaBase. He ...

'' the "

escargot Snails are considered edible in many areas such as the Mediterranean region, Africa, or Southeast Asia, while in other cultures, snails are seen as a taboo food. In American English, edible land snails are also called escargot, taken from the Fr ...

". The biologies of these two species in particular have been thoroughly studied and documented.

Shell description

The shells of these snails are mostly rather globular in shape. In some genera, such as ''

Cepaea ''Cepaea'' is a genus of medium-sized air-breathing land snails, terrestrial pulmonate gastropod mollusks in the family Helicidae. The shells of species within this genus are often brightly colored and patterned with stripes. The two specie ...

'', the shells are brightly colored and patterned.

Anatomy

The animal is capable of complete retraction within the shell. The tail is without a mucous gland or projection. Tryon G. W. 1887 ''Manual of conchology; structural and systematic. With illustrations of the species''. Second series: Pulmonata
Volume 3
Helicidae - Volume I. pag
3
��4. The mouth is always provided with a jaw, which is striate, ribbed, sulcate or plicate, sometimes composed of several imbricating pieces. The

radula The radula (, ; plural radulae or radulas) is an anatomical structure used by molluscs for feeding, sometimes compared to a tongue. It is a minutely toothed, chitinous ribbon, which is typically used for scraping or cutting food before the food ...

is composed of many transverse horizontal series of teeth, the centrals tricuspidate, about the size of the laterals, laterals bicuspid, or tricuspid with the interior cusp obsolete, marginals usually wider than high, short with two or three small cusps. In the soft parts the most obvious distinction is the lack of a caudal mucous pit, and their possessing a sculptured jaw. Typically, there is a distinction in the dentition, although in some species the lateral teeth take on a pseudozonitoid appearance; even in such cases the extreme marginals in ''Helix'' remain short and very obtuse. This family of snails is defined by the anatomical presence of a

diverticulum In medicine or biology, a diverticulum is an outpouching of a hollow (or a fluid-filled) structure in the body. Depending upon which layers of the structure are involved, diverticula are described as being either true or false. In medicine, t ...

. Some genera within this family create and use

love dart A love dart (also known as a gypsobelum, shooting darts, or just as darts) is a sharp, calcareous or chitinous dart which some hermaphroditic land snails and slugs create. Love darts are both formed and stored internally in a dart sac. Thes ...

s 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 Ploidy () is the number of complete sets of chromosomes in a cell, and hence the number of possible alleles for autosomal and pseudoautosomal genes. Sets of chromosomes refer to the number of maternal and paternal chromosome copies, respecti ...

chromosome A chromosome is a long DNA molecule with part or all of the genetic material of an organism. In most chromosomes the very long thin DNA fibers are coated with packaging proteins; in eukaryotic cells the most important of these proteins ar ...

s lies between 21 and 30 (according to the values in this table).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, . 1-146, cited pages: 139 and 142.

Distribution

The family is native to

Eurasia Eurasia (, ) is the largest continental area on Earth, comprising all of Europe and Asia. Primarily in the Northern and Eastern Hemispheres, it spans from the British Isles and the Iberian Peninsula in the west to the Japanese archipelago ...

and belongs to the Western

Palearctic The Palearctic or Palaearctic is the largest of the eight biogeographic realms of the Earth. It stretches across all of Eurasia north of the foothills of the Himalayas, and North Africa. The realm consists of several bioregions: the Euro-S ...

group. However some species, notably ''

'', have been introduced and become established in numerous different areas 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.

Genera

The family Helicidae contains 3 subfamilies (according to molecular phylogenetic analyses):

Subfamily Helicinae Rafinesque, 1815

In this subfamily the glands are divided. The love dart has four blades or vanes. There are usually two penial papillae.

Tribe Allognathini

*''

Allognathus ''Allognathus'' is a genus of air-breathing land snails, terrestrial pulmonate gastropod mollusks in the family Helicidae, the true snails. The genus is endemic to the Balearic Islands (Western Mediterranean) being present in all major islands a ...

'' *''

'' Held, 1838 *'' Hemicycla'' *'' Iberus'' *'' Pseudotachea''

Tribe Helicinini Rafinesque, 1815

* '' Assyriella'' * '' Caucasotachea'' * '' Codringtonia'' * ''

Helix A helix () is a shape like a corkscrew or spiral staircase. It is a type of smooth space curve with tangent lines at a constant angle to a fixed axis. Helices are important in biology, as the DNA molecule is formed as two intertwined helices ...

Linnaeus Carl Linnaeus (; 23 May 1707 – 10 January 1778), also known after his ennoblement in 1761 as Carl von Linné Blunt (2004), p. 171. (), was a Swedish botanist, zoologist, taxonomist, and physician who formalised binomial nomenclature, ...

1758 Events January–March * January 1 – Swedish biologist Carl Linnaeus (Carl von Linné) publishes in Stockholm the first volume (''Animalia'') of the 10th edition of ''Systema Naturae'', the starting point of modern zoological ...

type genus In biological taxonomy, the type genus is the genus which defines a biological family and the root of the family name. Zoological nomenclature According to the International Code of Zoological Nomenclature, "The name-bearing type of a nominal ...

* †'' Megalotachea'' Pfeffer, 1930 * '' Isaurica'' * '' Levantina'' Kobelt, 1871 * '' Lindholmia'' * '' Maltzanella'' * :'' Neocrassa'' * ''Tyrrhenaria'': synonym of ''

'' Linnaeus, 1758 * '' Xeroleuca'' Kobelt, 1877

Tribe Otalini

* '' Cantareus'' Risso, 1826 * '' Cornu'' Born, 1778 * '' Eobania'' P. Hesse, 1913 * '' Massylaea'' Möllendorff, 1898 * '' Otala'' Schumacher, 1817 * '' Rossmaessleria''

Tribe Thebini

* ''

Theba ''Theba'' is a taxonomic genus of air-breathing land snails, medium-sized pulmonate gastropod mollusks in the family Helicidae, the true snails. MolluscaBase eds. (2021). MolluscaBase. Theba Risso, 1826. Accessed through: World Register of Mar ...

'' Risso, 1826 A 2022 phylogenetic analysis proposed that all groups of the

Maghreb The Maghreb (; ar, الْمَغْرِب, al-Maghrib, lit=the west), also known as the Arab Maghreb ( ar, المغرب العربي) and Northwest Africa, is the western part of North Africa and the Arab world. The region includes Algeria, ...

radiation belonged to a single tribe, Thebini, without support for a separate Otalini tribe. The same study proposed a new tribe, Maculariini trib. nov. containing the genus '' Macularia'' due to the wide geographic disjunction between the western Alpine '' Macularia'' and the primarily Maghrebian Thebini tribe.

Subfamily Murellinae

Tribe Murellini Hesse, 1918

* '' Macularia'' Albers, 1850 *'' 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.Nordsieck H. (2006). ''Higher classification of Helicoidea and the molecular analyses of their phylogeny''
hnords.de
, Accessed 20/06/12 *'' Tacheocampylaea'' *'' Tyrrheniberus''

Subfamily Ariantinae Mörch, 1864

In this subfamily the glands are divided or undivided. The love darts contain two to four blades. There is only one penial papilla. *'' Arianta'' Turton, 1831 *'' Campylaea'' H. Beck, 1837 *'' Campylaeopsis'' A.J. Wagner, 1914 * '' Cattania'' Brusina, 1904 *''

Causa ''Causa'' is a genus of air-breathing land snails, terrestrial 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 (). Aro ...

'' Schileyko, 1971 *'' Chilostoma'' Fitzinger, 1833 *'' Corneola'' Held, 1838 *'' Cylindrus'' Fitzinger, 1833 *'' Delphinatia'' P. Hesse, 1931 *'' Dinarica'' Kobelt, 1902 *'' Drobacia'' Brusina, 1904 *'' Faustina'' Kobelt, 1904 *'' Helicigona'' A. Férussac, 1821 *'' Isognomostoma'' Fitzinger, 1833 *'' Josephinella'' F. Haas, 1936 *'' Kollarix'' Groenenberg, Subai & E. Gittenberger, 2016 *'' Kosicia'' Brusina, 1904 *'' Liburnica'' Kobelt, 1904 *'' Mesodontopsis'' Pilsbry, 1895 † *'' Metacampylaea'' Pilsbry, 1895 † *'' Paradrobacia'' H. Nordsieck, 2014 † *'' Pseudoklikia'' H. Nordsieck, 2018 † *'' Pseudotrizona'' Groenenberg, Subai & E. Gittenberger, 2016 *'' Thiessea'' Kobelt, 1904 *'' Vidovicia'' Brusina, 1904 *'' Pseudochloritis'' C. R. Boettger, 1909

''Incertae sedis''

*'' Idiomela'' T. Cockerell, 1921 *'' Lampadia''

References

External links

{{taxonbar, from=Q1418257 Helicoidea Gastropod families Taxa named by Constantine Samuel Rafinesque