Clausilia dubia is a species of small, very elongate, left-handed air-breathing land snail, a sinistral terrestrial pulmonate gastropod mollusk in the family Clausiliidae, the door snails, all of which have a clausilium.MolluscaBase eds. (2020). MolluscaBase. Clausilia dubia Draparnaud, 1805. Accessed through: World Register of Marine Species at: http://marinespecies.org/aphia.php?p=taxdetails&id=1050049 on 2020-08-17
Subspecies Clausilia dubia alpicola Clessin, 1878 Clausilia dubia bucculenta Klemm, 1960 Clausilia dubia carpathica Brancsik, 1888 Clausilia dubia dubia Draparnaud, 1805 Clausilia dubia dydima F. J. Schmidt, 1847 Clausilia dubia floningiana Westerlund, 1890 Clausilia dubia geretica Bourguignat, 1877 Clausilia dubia gracilior Clessin, 1887 Clausilia dubia gratiosa Sajó, 1968 Clausilia dubia grimmeri L. Pfeiffer, 1848 Clausilia dubia huettneri Klemm, 1960 Clausilia dubia ingenua Hudec & Brabenec, 1963 Clausilia dubia kaeufeli Klemm, 1960 Clausilia dubia otvinensis H. von Gallenstein, 1895 Clausilia dubia runensis Tschapeck, 1883 Clausilia dubia schlechtii A. Schmidt, 1856 Clausilia dubia speciosa A. Schmidt, 1856 Clausilia dubia suttoni Westerlund, 1881 Clausilia dubia tettelbachiana Rossmässler, 1838 Clausilia dubia vindobonensis A. Schmidt, 1856
Distribution The species is widespread in Europe, living in countries and islands including (among others):
Austria Czech Republic Great Britain, the north of England Slovakia UkraineBalashov I. & Gural-Sverlova N. 2012. An annotated checklist of the terrestrial molluscs of Ukraine. Journal of Conchology. 41 (1): 91-109.
In Finland, as of 2019, the species is only known to live in two locations: the Ylistönmäki hill in Jyväskylä and the Kettuvuori hill in Heinola. Formerly, they had also been found on the Riihivuori hill in Muurame, but disappeared after a skiing center was built there. The species may have spread to Finland during a warm, rainy period in the 18th century.
Description All the species of snails in the family of door snails are left-handed, which is an uncommon feature in gastropods in general. These snails have shells which are extremely high-spired, with numerous whorls.
Clausilia dubia is a relatively large species for this family, reaching 16 mm in height.
The weight of the adult live snail is about 123 mg.
References
Bank, R. A.; Neubert, E. (2017). Checklist of the land and freshwater Gastropoda of Europe. Last update: July 16, 2017 Sysoev, A. V. & Schileyko, A. A. (2009). Land snails and slugs of Russia and adjacent countries. Sofia/Moskva (Pensoft). 312 pp., 142 plates