Helicidae


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 the brown or garden snail, and Helix pomatia. 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 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 are scheduled for whole genome sequencing and assembly.
Image:Snails-Italy.jpg|thumb|Helicid snails for sale as food in Italy; from the front Eobania vermiculata, Cantareus apertus, and Helix sp.

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, Canary Islands and the Madeira Archipelago. 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

Image:Snail black on grass2.jpg|thumb|Arianta arbustorum
Image:Iberus gualterianus alonensis3.JPG|thumb|Iberus gualtieranus alonensis
The family Helicidae contains 3 subfamilies :

Subfamily [Helicinae] Rafinesque, 1815

Genital system anatomy : mucous glands divided into 2 or more branches, love dart with four blades along its length, two penial papillae/verges.

Tribe Allognathini Westerlund, 1903

Tribe [Helicini] [Rafinesque], 1815

Aristena Psonis, Vardinoyannis & Poulakakis, 2022Amanica Nordsieck, 2017Caucasotachea Boettger, 1909Codringtonia Kobelt, 1898Helix Linnaeus, 1758 - type genusIsaurica Kobelt, 1901Levantina Kobelt, 1871Lindholmia Hesse, 1918Maltzanella Hesse, 1917Neocrassa Subai, 2005

Tribe Thebini Wenz, 1923

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, 1826Cornu Born, 1778Eobania P. Hesse, 1913Eremina Pfeiffer, 1855Gyrostomella P. Hesse, 1911Loxana Pallary, 1899Massylaea Möllendorff, 1898Otala Schumacher, 1817Rossmaessleria P. Hesse, 1907Theba Risso, 1826

Tribe Maculariini Neiber, Korábek, Glaubrecht & Hausdorf, 2021

Macularia Albers, 1850

Subfamily Murellinae Hesse, 1918

Genital system anatomy : 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.

Subfamily Ariantinae Mörch, 1864

Genital system anatomy: mucous glands divided into 2 branches or undivided, love dart with two blades on the tip, one penial papilla.

''Incertae sedis''