Pyramidula rupestris
( Pyramidula rupestris )
Pyramidula rupestris, also called rock pyramid snail, a terrestrial snail from the family of pyramid snails ( Pyramidulidae ).
- 5.1 Literature
- 5.2 Notes and references
- 5.3 online
Features
The housing measures 1.4 to 2.5 mm (or 1.4 to 2 mm ) in height and from 2.5 to 2.7 mm (2.5 to 3 mm) in width. It varies from slightly wider than high up much higher than it is wide. The 4-4 ½ turns are curved and edged by a deep suture greatly. It is frustoconical with almost straight side lines. The umbilicus is wide open and takes up about ¼ of the total diameter a. The fresh case is colored dark brown, somewhat older weathered housing are white gray. Often the cases are also covered with rock crumbs and lichens residues. The Embryonalgehäuse is only visible with a strong magnifying glass, covered with fine pustules; with the naked eye, it appears almost smooth. The juvenile and adult housing, however, is covered with more or less irregular growth lines. The mouth is formed rounded, the mouth rim is simple, not reinforced and very fragile. The last whorl forms at the periphery of a blunt edge.
The soft body is dark gray to black. The antennae are moderately long, relatively thick and relatively strongly thickened at the upper end.
Similar Species
The housing of the rock pyramid snail is very similar to the recently separated as an independent type Pyramidula pusilla Gittenberger & Bank, 1996. Species is slightly bigger on average.
Geographical distribution and habitat
The distribution area includes Western Europe and the Mediterranean region, including North Africa and the Middle East. In the east, the range extends to Central Asia. The species occurs also in the Canary Islands. In Germany it is mainly located in the southwest, as northernmost occurrence in Germany Hönnetal in the Sauerland, the Ith and Thuringia apply.
The kind to have been found up to 3000 m above sea level. The information about the distribution are of limited reliability because it has been separated only recently a new taxon ( Pyramidula pusilla Gittenberger & Bank, 1996) of P. rupestris. Older data do not distinguish between the two taxa. Thus, for example, found recently that in Bulgaria not P. rupestris occurs, but P. pusilla; that is, the earlier evidence of P. rupestris in Bulgaria are suppose to relate to P. pusilla all.
The rock pyramid screw is preferred to find warm and dry, often exposed directly to the south limestone and lime walls, often in small groups in cracks, small pits or small overhangs. Less often you meet them on sloping north slopes or rarely even near rocks on. During times of drought, many copies do not take into protected crevices or columns back, but attach themselves very firmly to the substrate. They can be easily broken and deported in this way with calcareous natural stones.
Way of life
The animals feed on endolithic algae and lichens. The stones are rasped with the help of the radula and added Gesteinsgrus and algae. Therefore, the feces contain not only indigestible algae and lichen remains large amounts of calcium carbonate.
The animals are dioecious. Reproduction takes place over Ovoviviparie. The housing of pups measured at the time of the "birth" of about 0.7 mm in diameter.
Systematics and Taxonomy
The taxon was described in 1801 by Jacques Philippe Raymond Draparnaud as Helix rupestris first time. It is the type species of the genus Pyramidula Fitzinger, 1833. However, was not recognized until recently that actually hide among two or three species, Pyramidula rupestris s.str. and Pyramidula pusilla Gitte Berg & Bank, 1996. Occasionally, the now mostly recognized as a separate type Pyramidula chorismenostoma ( Blanc, 1879) considered a subspecies of Pyramidula rupestris. Accordingly, for example, must the species description are somewhat limited.
Currently, two subspecies are distinguished:
- Pyramidula rupestris rupestris ( Draparnaud, 1801), the Nominatunterart
- Pyramidula rupestris hierosolymitana Bourguignat, 1852