Causa holosericea
Genabelte mask worm ( Causa holosericea )
The Genabelte mask worm ( Causa holosericea ) is a terrestrial snail from the family of helicid ( Helicidae ).
Features
The casing is thick disc-shaped with 4.5 to 5 turns, if the animal is adult. The coil is lifted only slightly out of the plane. It measures about 5 to 6 x 9 to 12 mm. The whorls are convex and form a distinct suture; they take too slowly. The end turn is closely below the top edge of a (about 1/3 as viewed from the top), the bottom is flattened. She is at first faintly lowered toward the mouth. It was not until the last quarter or fifth lowers stronger. The umbilicus is relatively wide and deep, reaching 1/5 to 1/4 of the total diameter. The opening is at an oblique angle to the coil axis; the back part before projecting. It is roughly rectangular with rounded corners. The mouth edge is relatively sharp exterior, interior thickened lipped; the lip is white. The mouth extend into two or three rounded triangular teeth, a tooth from the outer edge, and one or two teeth of the bottom edge. On the outside behind the mouth of shallow pits are designed, corresponding to the teeth on the inside.
The body is brown to reddish- brown and opaque. The outside has fine, somewhat irregular growth lines. It is finely gekörnelt and densely covered with short, stiff, curved hairs. Hair fall from or be scraped off, they leave fine scars. The animal is dark gray to black-gray, the top is usually a bit darker than the sides.
Geographic occurrence and habitat
The Genabelte mask worm occurs in the Alps and in the Swiss Jura, in a few isolated locations in the low mountain ranges of Germany ( Bavarian Alps, Bavarian Forest, Ore Mountains, Franconian Switzerland, Northern Franconian Jura), Czech ( Bohemian Massif, Northern Carpathians), in the Slovak Ore ( Veporer Mountains) and in the Polish middle and high mountains ( Sudetes, Tatra ) ago. A deposit is located in western Belarus.
She lives mainly in moist coniferous forests with rocky ground, often on lime-poor soils rubble with rotting wood, but also on rocky, grassy slopes and between rocks. It usually lives in the middle and high mountains at altitudes between 1000 and 2000 m above sea level; in Switzerland is the highest occurrence at 2800 m.
Way of life
Little is known about the way of life. According to Ewald Frömming the animals ate under laboratory conditions no fresh plant material, but the fruiting bodies of various fungi.
Systematics and Nomenclature
The species is often attributed in the literature Samuel Emanuel Studer, eg Fechter & Falkner (1990 ), Kerney et al. (1983) and Bogon (1990). Frequently, Johann Friedrich Gmelin appears with the year 1791. The type was, however, published in 1788 by Johann Friedrich Gmelin under the name Helix holosericea. Later the species was usually found to be Isognomostoma holosericeum to the genus Isognomostoma.
Endangering
The species is on the Red List of Saxony listed as endangered ( Level 2). In Bavaria, the species is classified in Level 3 ( endangered).