White-lipped snail

Description

Cepaea hortensis has a shell up to 22 mm in diameter, tending to be slightly smaller than C. nemoralis. The umbilicus is closed in adults, but narrowly open in juveniles. Although the shells of C. hortensis are most commonly yellow, they exhibit a range of background colours from brown through pink to pale yellow, and up to five brown bands may be present, some of which may fuse with their neighbours. This polymorphism, which is shared with Cepaea nemoralis, has been the subject of considerable research.

This species of snail creates and uses love darts during mating.

The size of the egg is 2 mm.

|Cepaea.hortensis.jpg|Cepaea hortensis |White-lipped Snail (Cepaea hortensis).webm|Specimen in the United Kingdom |Cepaea hortensis - Shell 35.jpg|Yellow shell with five unfused bands

Similar species

In most areas adults of C. hortensis can be distinguished by the pale colouration of the lip around the shell aperture, whereas it is typically brown in C. nemoralis. But in some areas (e.g. Ireland, Pyrenees) C. nemoralis can have a white lip, and C. hortensis can rarely have a brown lip. More certain characters require dissection. A cross section of the love dart of C. hortensis shows a cross with bifurcated blades, whereas that of C. nemoralis is a simple cross. The mucous gland has 4 or more branches in C. hortensis, but 3 or fewer branches in C. nemoralis.

Caucasotachea vindobonensis and Macularia sylvatica are two superficially similar species formerly mistakenly included in the genus Cepaea. Both have a lip that is brown near the columella becoming pale towards the suture, and they have fine growth ridges on the shell whereas in both Cepaea species it is smooth.

Distribution and habitat

The native distribution of this species is Western and Central Europe. Also its occurrence along the coast of northeastern North America should be considered native, since archaeological deposits reveal it to have been present at least 7850 years ago, so before the presence of Viking explorers. The range of C. hortensis extends further north in Scotland than that of C. nemoralis and it is the only Cepaea species in Iceland and northern parts of Scandinavia (up to 67° 30' N). Conversely, the southern limit of C. hortensis is also further north: in Spain it occurs only in the north-east and it is absent from Italy. Cepaea hortensis has been recently introduced to the Moscow region of Russia and to Ukraine, but has not established itself as widely as C. nemoralis. It reaches an altitude of 2050 m in the Swiss Alps.

The two Cepaea species share many of the same habitats, such as woods, dunes and grassland, but the white-lipped snail tolerates wetter and colder areas.

References

References

1. Müller, O. F. 1774. ''Vermivm terrestrium et fluviatilium, seu animalium infusoriorum, helminthicorum, et testaceorum, non marinorum, succincta historia''. Volumen alterum. - pp. I-XXVI [= 1-36], 1-214, [1-10]. Havniae & Lipsiae. (Heineck & Faber).
2. 0-85199-318-4. 1-146, cited page: 428.
3. (1977). "Polymorphism in ''Cepaea'': a problem with too many solutions?". Annual Review of Ecology and Systematics.
4. (2012). "European non-marine molluscs, a guide for species identification = Bestimmungsbuch für europäische Land- und Süsswassermollusken". Planet Poster Editions.
5. (2015). "Molecular phylogeny reveals the polyphyly of the snail genus ''Cepaea'' (Gastropoda: Helicidae)". Molecular Phylogenetics and Evolution.
6. (2016). "Increasing the number of molecular markers resolves the phylogenetic relationship of "''Cepaea''" ''vindobonensis'' (Pfeiffer 1828) with ''Caucasotachea'' Boettger 1909 (Gastropoda: Pulmonata: Helicidae)". Journal of Zoological Systematics and Evolutionary Research.
7. (1979). "A field guide to the land snails of Britain and north-west Europe". Collins.
8. (10 August 2010). "Land snails from St. Elzear cave, Gaspé Peninsula, Quebec: antiquity of ''Cepaea hortensis'' in North America.". Annals of Carnegie Museum.
9. (February 1976). "Polymorphism in relation to habitat in the snail ''Cepaea hortensis'' in Iceland.". Journal of Zoology.
10. (12 February 2009). "Colour polymorphism in northern peripheral populations of ''Cepaea hortensis''". Hereditas.
11. (2016). "Caracoles y babosas de la Península Ibérica y Baleares". Omega.
12. "Checklist of the Italian Fauna On-line version 2.1". Ministry of Environment, Directorate-General for Nature and Sea Protection (PNM).
13. "''Cepaea hortensis''". University of Göttingen.
14. (2015). "The first record of introduced snail ''Cepaea hortensis'' (Müller, 1774) (Stylommatophora: Helicidae) in the central part of European Russia". Ruthenica.
15. (27 September 2021). "Introduced land snail ''Cepaea nemoralis'' (Gastropoda: Helicidae) in Eastern Europe: spreading history and the shell colouration variability". Malacologica Bohemoslovaca.
16. (1998). "Atlas der Mollusken der Schweiz und Liechtensteins". CentreSuisse de cartographie de la faune.