Helicidae is a large, diverse family of western Palaearctic, medium to large-sized, air-breathing land snails, sometimes called the "typical snails." It includes some of the largest European land snails, several species are common in anthropogenic habitats, and some became invasive on other continents. A number of species in this family are valued as food items, including Cornu aspersum (formerly Helix aspersa; "petit gris") the brown or garden snail, and Helix pomatia (the "escargot").M.P. Kerney & R.A.D. Cameron. 1979. A field guide to the land snails of Britain and northwestern Europe. Collins, London. The biologies of these two species in particular have been thoroughly studied and documented.
Shell description
The shells are usually flattened or depressed conical. Globular shells are found in the genera Helix, Maltzanella, Lindholmia, Cornu, Cantareus, Eremina, and Idiomella. One species, Cylindrus obtusus, has a cylindrical shell. In some genera, especially in Cepaea, the shells are brightly colored and patterned.
Anatomy Helicidae typically have a ribbed jaw, bursa copulatrix with a diverticulum, and one dart sac accompanied by a pair of (usually) branched, tubular mucous glands inserting at the base of the dart sac.
Genetics In this family, the number of haploid chromosomes lies between 22 and 30.
In the " project, four species (Cepaea nemoralis, Cepaea hortensis, Cornu aspersum, and Arianta arbustorum) are scheduled for whole genome sequencing and assembly ().
Distribution The core of helicids is distributed in from the Caucasus through Turkey and Europe to North Africa. However, some genera or species live beyond these limits. Helicids occur on Cape Verde (Eremina), Canary Islands (Theba, Hemicycla) and the Madeira Archipelago (Lampadia, Idiomela). Levantina extends far south in western Arabia, and Eremina desertella is distributed as south as Sudan, Eritrea and Puntland in Somalia. Cepaea hortensis lives on Iceland and in a small area in eastern Canada. Some species, notably Cornu aspersum and Theba pisana have been introduced and become established in numerous different areas worldwide.
Taxonomy
The family Helicidae contains 3 subfamilies (according to molecular phylogenetic analyses):
Subfamily Helicinae Rafinesque, 1815 Genital system anatomy (does not apply on all species, as derived states are found in some of them): mucous glands divided into 2 or more branches, love dart with four blades (vanes) along its length, two penial papillae/verges.
Tribe Allognathini Westerlund, 1903 Source: Allognathus Cepaea Held, 1838 Hemicycla Iberus Idiomela T. Cockerell, 1921 Lampadia
Tribe Helicini Rafinesque, 1815 Source: Aristena Psonis, Vardinoyannis & Poulakakis, 2022 Amanica Nordsieck, 2017 Caucasotachea Boettger, 1909 Codringtonia Kobelt, 1898 Helix Linnaeus, 1758 - type genus Isaurica Kobelt, 1901 Levantina Kobelt, 1871 Lindholmia Hesse, 1918 Maltzanella Hesse, 1917 Neocrassa Subai, 2005
Tribe Thebini Wenz, 1923 Source:
A 2022 phylogenetic analysis proposed that all groups of the Maghreb 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. Cantareus Risso, 1826 Cornu Born, 1778 Eobania P. Hesse, 1913 Eremina Pfeiffer, 1855 Gyrostomella P. Hesse, 1911 Loxana Pallary, 1899 Massylaea Möllendorff, 1898 Otala Schumacher, 1817 Rossmaessleria P. Hesse, 1907 Theba Risso, 1826
Tribe Maculariini Neiber, Korábek, Glaubrecht & Hausdorf, 2021 Macularia Albers, 1850
Subfamily Murellinae Hesse, 1918 Source:
Genital system anatomy (does not apply on all species, as derived states are found in some of them): mucous glands weakly branched or undivided, love dart with four blades along its length, one penial papilla.
Distributed in Sardinia, Corsica, the Apennine Peninsula and Sicily. Marmorana W. Hartmann, 1844 Tacheocampylaea Tyrrheniberus
Subfamily Ariantinae Mörch, 1864 Source:
Genital system anatomy: mucous glands divided into 2 branches or undivided, love dart with two blades on the tip, one penial papilla. Arianta Turton, 1831 Campylaea H. Beck, 1837 Campylaeopsis A.J. Wagner, 1914 Cattania Brusina, 1904 Causa 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 Pseudotrizona Groenenberg, Subai & E. Gittenberger, 2016 Thiessea Kobelt, 1904 Vidovicia Brusina, 1904 Pseudochloritis C. R. Boettger, 1909 Mesodontopsis Pilsbry, 1895 Metacampylaea Pilsbry, 1895 Paradrobacia H. Nordsieck, 2014 Pseudoklikia H. Nordsieck, 2018
Incertae sedis †Megalotachea Pfeffer, 1930
References
External links