C. hortensis with a yellow shell and five unfused bands
Cepaea hortensis has a shell up to 22 mm (1 in) in diameter, tending to be slightly smaller than C. nemoralis. The umbilicus is closed in adults, but narrowly open in juveniles.[2] 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.[3](See Cepaea § Shell polymorphism.)
Love dart of C. hortensis; scale bars are 0.5 mm in upper image and 50 μm in the cross-section
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.[3] More certain characters require dissection. A cross-section of the love dartofC. hortensis shows a cross with bifurcated blades, whereas that of C. nemoralis is a simple cross. The mucus gland has 4 or more branches in C. hortensis, but 3 or fewer branches in C. nemoralis.[2]
Caucasotachea vindobonensis and Macularia sylvatica are two superficially similar species formerly mistakenly included in the genus Cepaea.[4][5] 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.[6]
The native distribution of this species is Western Europe 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.[7] 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).[8][9] 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.[10][11][12]Cepaea hortensis has been recently introduced to the Moscow region of Russia[13] and to Ukraine,[14] but has not established itself as widely as C. nemoralis. It reaches an altitude of 2050 m in the Swiss Alps.[15]
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.[3]
^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).
^ abWelter-Schultes, F.W. (2012). European non-marine molluscs, a guide for species identification = Bestimmungsbuch für europäische Land- und Süsswassermollusken. Göttingen: Planet Poster Editions. ISBN9783933922755.
^ abcJones, J.S.; Leith, B.H.; Rawlings, P. (1977). "Polymorphism in Cepaea: a problem with too many solutions?". Annual Review of Ecology and Systematics. 8 (1): 109–143. doi:10.1146/annurev.es.08.110177.000545.
^Neiber, M.T.; Hausdorf, B. (2015). "Molecular phylogeny reveals the polyphyly of the snail genus Cepaea (Gastropoda: Helicidae)". Molecular Phylogenetics and Evolution. 93: 143–149. doi:10.1016/j.ympev.2015.07.022. PMID26256642.
^Kerney, M.P.; Cameron, R.A.D. (1979). A field guide to the land snails of Britain and north-west Europe. London: Collins. ISBN000219676X.
^Pearce, T.A.; Olori, J.C.; Kemezis, K.W. (10 August 2010). "Land snails from St. Elzear cave, Gaspé Peninsula, Quebec: antiquity of Cepaea hortensis in North America". Annals of Carnegie Museum. 79 (1): 65–78. doi:10.2992/007.079.0105.
^Bengtson, S.‐A.; Nilsson, A.; Nordström, S.; Rrundgren, S. (February 1976). "Polymorphism in relation to habitat in the snail Cepaea hortensis in Iceland". Journal of Zoology. 178 (2): 173–188. doi:10.1111/j.1469-7998.1976.tb06006.x.
^Welter-Schultes, F. "Cepaea hortensis". Animal Base. University of Göttingen. Retrieved 21 April 2023.
^Egorov, R. (2015). "The first record of introduced snail Cepaea hortensis (Müller, 1774) (Stylommatophora: Helicidae) in the central part of European Russia". Ruthenica. 25 (3): 93–97.
^Turner, H.; Kuiper, J.G.J.; Thew, N.; Bernasconi, R.; Rüetschi, J.; Wüthrich, M.; Gosteli, M. (1998). Atlas der Mollusken der Schweiz und Liechtensteins. Neuchâtel: CentreSuisse de cartographie de la faune. ISBN2884140131.
