Toothless door snail
| Toothless door snail | ||||||||||||
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Balea perversa |
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| Systematics | ||||||||||||
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| Scientific name | ||||||||||||
| Balea perversa | ||||||||||||
| Linnaeus , 1758 |
The toothless door snail ( Balea perversa ) is a small land snail with a left-handed shell that also occurs in Germany, Austria and Switzerland.
features
The conical housing (7-10 × 2.5-2.7 mm) is light brownish or greenish yellow in color. It has eight to nine coils, with the last coil also being the widest, unlike many other door snails. It looks shiny, which is due to the very fine ribbing. The mouth is square and toothless except for the upper lamella, which is reduced to a small callus. The clausilium , which gives the door snail family its name, is missing.
Way of life
Balea perversa lives in moss, in coarse tree bark, tree hollows and un jointed walls, on roadsides and rocky embankments, more rarely in the litter. The snail feeds on mosses , algae , lichens and cyanobacteria .
The animals can give birth to 10 to 20 young ( ovoviviparous ) per year . Under favorable conditions, it takes three to four months to reach sexual maturity. The snails are easily spread by birds.
Spread and endangerment
The main distribution of the toothless door snail is in Western Europe and the British Isles. Earlier information about its distribution in Eastern Europe is now being questioned.
It is endangered by the loss of its biotopes (modernization of old buildings, removal of old trees), acid rain and air pollution. The snail is integrated into near-natural ecosystems; it has largely disappeared from urban areas. In Germany it occurs only scattered and is endangered (RL-D 2009: endangerment level 3), in Bavaria it is highly endangered (RL-BY 2003: endangerment level 2). It is also considered endangered in Austria (RL-At: endangerment level 3). In Switzerland it is classified as "vulnerable" (RL-Ch: VU).
Individual evidence
- ^ Vollrath Wiese: The land snails of Germany . Quelle & Meyer Verlag 2014, 352 pp. ISBN 978-3-494-01551-4
- ↑ a b c "Species summary for Balea perversa " . AnimalBase , last modified Jan. 10, 2015, accessed Nov. 14, 2018.
- ^ Edmund Gittenberger, Dick SJ Groenenberg, Bas Kokshoorn and Richard C. Preece: Molecular trails from hitch-hiking snails. Nature volume 439, page 409 (January 26, 2006).
- ^ Francisco Welter-Schultes: European non-marine molluscs, a guide for species identification (2012). ISBN 978-3-933922-75-5 .
- ↑ Balea perversa . Fauna Europaea. Retrieved November 14, 2018.
