Helix pomatia, known as theRoman snail,Burgundy snail, orescargot, is a species of large, air-breathingstylommatophoran landsnail native to Europe. It is characterized by a globular brown shell. It is an edible species which commonly occurssynanthropically throughout its range.
Distribution map ofH. pomatia showing the European countries where the species is presentInOdenwald, GermanyHelix pomatia, light micrograph of an eye;1 anterior chamber,2 lens,3 retina,4 optic nerve
The presentdistribution ofHelix pomatia is considerably affected by the dispersion byhuman and synanthropic occurrences. The northern limits of their natural distribution run presumably through centralGermany and southernPoland with the eastern range limits running through western-mostUkraine andMoldova/Romania toBulgaria. In the south, the species reaches northern Bulgaria, centralSerbia,Bosnia and Hezegovina andCroatia. It occurs in northernItaly southwards to thePo and theLigurian Apennines. Westerly the native range extends to easternFrance.[4][5] Currently,H. pomatia is distributed up to western Russia (broadly distributed in and aroundMoskva),[6] to the south ofFinland,Sweden andNorway, inDenmark and theBenelux. Scattered introduced populations occur westwards up to northernSpain. InGreat Britain, it lives onchalk soils in the south and west ofEngland. In the east, isolated populations live as far as south of Novosibirsk.[6] Introduced populations also exist in the easternUnited States andCanada.[7]
Theshell is creamy white to light brownish, often with indistinct brown colour bands although sometimes the banding is well developed and conspicuous. The shell has five to sixwhorls. Theaperture is large. The apertural margin is slightly reflected in adult snails. Theumbilicus is narrow and partly covered by the reflected columellar margin.[8]
The width of the shell is 30–50 millimetres (1.2–2.0 inches).[8] The height of the shell is 30–45 mm (1.2–1.8 in).[8]
In Central Europe, it occurs in forests and shrubland, as well as in various synanthropic habitats. It lives up to 2,100 m (6,900 ft) above sea level in the Alps, but usually below 2,000 m (6,600 ft).[8] In the south of England, it is restricted to undisturbed grassy or bushy wastelands, usually not in gardens.[8]
A pair ofH. pomatia in courtship, shortly before mating
Drawing of head of matingH. pomatia with everted penis and dart sac shooting alove dart
Drawing ofH. pomatia laying eggs
Eggs are laid in June and July, in clutches of 40–65 eggs.[8] The size of the egg is 5.5–6.5 mm[8] or 8.6 × 7.2 mm.[9] Juveniles hatch after three to four weeks, and may consume their siblings under unfavourable climate conditions.[8] Maturity is reached after two to five years.[8] The life span is up to 20 years, but they often die sooner due to drying in summer and freezing in winter.[8] Ten-year-old individuals are probably not uncommon in natural populations.[8] The maximum lifespan is 35 years.[8]
This species is listed inIUCN Red List, and in European Red List of Non-marine Molluscs as of least concern.[1][11]H. pomatia is threatened by continuoushabitat destructions and drainage, usually less threatened by commercial collections.[8] Many unsuccessful attempts have been made to establish the species in various parts of England, Scotland, and Ireland; it only survived in natural habitats in southern England, and is threatened byintensive farming and habitat destruction.[8] It is of lower concern in Switzerland and Austria, but many regions restrict commercial collecting.[8]
Within its native range,Helix pomatia is mostly a common species. It is also consideredLeast Concern by theIUCN Red List.[1] However, it is listed in the Annex V of theEU'sHabitats Directive and protected by law in several countries to regulate harvesting from free living populations.
The intestinal juice ofH. pomatia contains large amounts of aryl, steroid, and glucosinolate sulfatase activities. These sulfatases have a broad specificity, so they are commonly used as a hydrolyzing agent in analytical procedures such as chromatography where they are used to prepare samples for analysis.[17]
Nowadays, these snails are especially popular in French cuisine. In the English language, it is called by the French nameescargot when used in cooking (escargot simply means snail).
Although this species is highly prized as a food, it is difficult to cultivate and is rarely farmed commercially.[19]
^Linnaeus C. (1758).Systema naturae per regna tria naturae, secundum classes, ordines, genera, species, cum characteribus, differentiis, synonymis, locis. Tomus I. Editio decima, reformata. pp. [1–4], 1–824. Holmiae. (Salvius).
Egorov R. (2015). "Helix pomatia Linnaeus, 1758: the history of its introduction and recent distribution in European Russia".Malacologica Bohemoslovaca14: 91–101.PDF
(in Russian) Roumyantseva E. G. & Dedkov V. P. (2006). "Reproductive properties of the Roman snailHelix pomatia L. in the Kaliningrad Region, Russia".Ruthenica15: 131–138.abstractArchived 2018-12-22 at theWayback Machine
