Vertigo genesii
Blanke 's whorl snail ( Vertigo genesii )
The Naked whorl snail ( Vertigo genesii ) is a species of snail from the family of the diaper snails ( Vertiginidae ) in the suborder of terrestrial snails ( gastropod ).
- 6.1 Literature
- 6.2 Notes and references
Features
The ovoid to cylindrical -shaped housing is 1.6 to 2.0 mm high and 1.0 to 1.2 mm wide. It has 3.5 to 5 convex turns which are separated by a deep seam. The mouth is oblique ovoid with a slightly flattened top. It is simple and without teeth, very rarely occurs a weakly pronounced Parietalzahn or a callus. The mouth rim is only slightly thickened and barely bent. The housing is weak reddish- brown to dark colored maroon. The surface is finely striated and therefore very smooth and shiny.
Similar Species
The case is similar to the tetradentate whorl snail ( Vertigo geyeri ). The housing is slightly conical and the opening is reinforced with up to four teeth.
Geographical distribution and habitat
The species is fairly common only in the mountains of central and northern Scandinavia. Isolated occurrences are known from southern Sweden, Finland, Germany, Switzerland, northern Italy, north of England, Scotland and Poland. In Switzerland, they are found only 1500-2100 m above sea level. In England, it was found in 300 to 500 m above sea level. According to recent studies, the species is found in southern Siberia, the Altai, in northern Mongolia and the Baikal region and the Tien Shan.
The animals live in open, calcareous seeps on hillsides, on marsh meadows and damp rocky mats of subalpine zone on karbonatreichem rocks and in swamps. Here they live between plant debris and vegetation clumps.
Way of life
Little is known about the way of life. In England it was found throughout the year juveniles, which account on average about 55 % of the population. This results in a high mortality. The frequency of the pups was from August to November the highest.
Taxonomy
The taxon was described in 1856 by Vincent Maria Gredler under the name Pupa Genesii first time. Some authors subdivide the genus into two subgenera Vertigo: Vertigo ( Vertigo ) OF Müller, 1773 and Vertigo ( Vertilla ) Moquin - Tandon, 1856th In this subgenus outline is provided the Tetradentate whorl snail into the genus Vertigo ( Vertigo ).
Endangering
In Germany the species is lost or extinct, the last evidence comes from before 1990.