Species name:
Helix pomatia Linnæus, 1758
Originally described in:
Linnæus, C. 1758. Systema naturæ per regna tria naturæ, secundum classes, ordines, genera, species, cum characteribus, differentiis, synonymis, locis. Tomus I. Editio decima, reformata. - pp. [1-4], 1-824. Holmiæ. (Salvius).
Distribution:
SE and central Europe, in the W to S England (probably introduced) and central France, in the N to S Sweden and Norway, in the E to Finland, Estonia, W Belarus and W Ukraine (Uzhgorod), Moldavia, Hungary, N and central Balkans to Rep. Makedonija, N Italy, introduced to Moskva, Kursk, Kyiv, Kharkiv. In SW Bulgaria up to more than 1600 m.
Diagnosis:
Shell creamy white to light brownish, often with indistinct brown colour bands, 5-6 whorls, aperture large, margin white and slightly reflected, umbilicus narrow and partly covered by the reflected columellar margin.
Size:
30-45 x 30-50 mm, egg diameter 5.5-6.5 mm
Biology:
In SE Europe in forests and open habitats, gardens, vineyards, especially along rivers, confined to calcareous substrate. In central Europe in open forests and shrubland on calcareous substrate. Prefers high humidity and lower temperatures, needs loose soil to burrow in order to hibernate and lay its eggs. Up to 2100 m in the Alps, usually below 2000 m. In S England restricted to undisturbed grassy or bushy wastelands, usually not in gardens, with a low reproduction rate and low powers of dispersal.
Average distance of migration reaches 3.5-6 m (Pollard 1975).
Reproduction in central Europe from end of May to September, 40-80 eggs (diameter 5.5-6.5 mm) are laid in clutches (usually 1 per season and individual), in a hole digged by circulating movements of the body inside the soil, usually after rain, juveniles hatch after 3-4 weeks and may consume their sisters under unfavourable climate conditions, the shell is initially whitish, yellowish brown after 8-14 days, after 1 year the shell has 2.5-4 whorls, in Hungary a first apertural margin is built in the third year. Maturity is reached after 2-5 years, life span up to 20 years, 10 year-old individuals are probably not uncommon in natural populations, maximum 35 years.
Threatened:
Threatened by continuous habitat destructions and drainage, usually less threatened by commercial collections. There were many unsuccessful attempts to establish the species in various parts of England, Scotland and Ireland, it only survived in natural habitats in S England, and is threatened by intensive farming and habitat destruction.
Lower concern in Switzerland and Austria, in many regions there are restrictions for commercial collections.
Comments:
References: Germain 1930: 183 (life cycle), Prince 1967, Pavlović 1912: 49 (Serbia), Frömming 1954: 346, Tomić 1959: 23, Damjanov & Likharev 1975: 401, Shilejko 1978: 346, Kerney & Cameron 1979: 205, Bech 1988: 108 (central Lleida, NE Spain, deliberately introduced), Falkner 1990: 250, Manganelli et al. 1995: 34, Turner et al. 1998: 378, Kerney 1999: 206, Falkner et al. 2001: 65, Irikov & Mollov 2006: 813, Sysoev & Schileyko 2009: 170, Welter-Schultes 2012: 615 (range map).
