Isognomostoma isognomostomos
Mask worm ( Isognomostoma isognomostomos )
The mask worm ( Isognomostoma isognomostomos ) is a Landschneckenart from the family of helicid ( Helicidae ), in the subordination of terrestrial snails ( gastropod ) is provided. The name comes from the snail mask some resembling a grinning mouth mouth of the shell here.
Features
The housing is flat cone-shaped and measures 4-7 x 11-14 mm. It has 5-6 turns with moderately arched whorls. The periphery of coping is rounded, the bottom is flat. The navel is slotted and sometimes covered by the aperture rim. The Basalrand and the outer edge of the mouth are internally thickened lamellar, the outer edge and Basalrand are pulled like teeth. The case mouth is rounded - triangular. The shell is relatively thin and translucent; it is colored brown horn. The top is fine gekörnelt and covered with fine, relatively long hairs.
Back, head and antennae of the animal are almost black in color, the sole is gray.
Life, the occurrence and distribution
The mask snail prefers to live in rocky rubble of relatively moist deciduous forests in the mountains and on the hills. In the vertical direction it comes from about 300 m in front of up to about 1800 m altitude. It feeds on decayed plant parts, but also fungi. For the winter rest, the housing is closed by a calcareous Epiphragma.
The mask worm occurs in the central part of Central Europe. The distribution area extends from the Spanish Pyrenees in the west, across central France and Südostbelgien about Switzerland, the southern half of Germany, the Czech Republic, Austria to Poland, Latvia, further south through Hungary to southern Russia. But it comes within this area against only very scattered.
Reproduction
The mask worm is like all terrestrial snails a hermaphrodite. The animals are mutually beneficial; the partner is stimulated with a 2.2 mm long, chalky love arrow. Eggs are laid in late June / early July. Otherwise, little is known about the reproduction. The animals are up to five years old.
System
The species was described in 1784 by the naturalist Johann Samuel Schröter under the name Helix isognomostomos first time. The species was later described under the name Helix personata Lamarck, 1792. This name is a junior synonym of Isognomostoma isognomostomos.
Endangering
The occurrence of the mask worm are very scattered; the mask screw is therefore not a common animal. However, it comes in suitable habitat still remains relatively numerous. It therefore applies in Germany as not at risk.
Soft animal of the year
The mask screw was 2007 mollusc of the year. "The title is awarded by a board of trustees, which has made it its mission to inform the public of selected species and make in this way also molluskenkundliche topics and conservation issues on the known. "