Summit glass snail
| Summit glass snail | ||||||||||||
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European summit snail ( Eucobresia pegoraii ) |
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| Scientific name | ||||||||||||
| Eucobresia pegorarii | ||||||||||||
| ( Pollonera , 1884) |
The summit glass snail ( Eucobresia pegorarii ) is a "half- nudibranch " from the family of glass snails (Vitrinidae), which is counted among the land snails (Stylommatophora). The animals can no longer withdraw into the small housing.
features
The right-hand wound, small housing is ear-shaped with a very flat thread. It can still be seen in the side view. It has 2.5 slowly growing coils and measures 4.3 to 6 mm in diameter and 2.5 mm in height. The top of the turns is very flat, the seam is hardly deepened. At the bottom the turns are strongly arched. The mouth width is 4.2 mm, the mouth height 3 mm. The last turn is about wider than the thread. A navel is not developed. The mouth rim is straight and tapered thin. The strongly elliptical mouth is very oblique to the winding axis. At the bottom of the mouth there is a moderately wide skin seam. The outer edge of the mouth is slightly curved.
The shell is very thin and fragile. The embryonic housing consists of 1¾ turns. It is milky and cloudy. The Teleoconch is yellowish horn-colored and translucent. The surface is slightly wrinkled radially and very shiny.
The outstretched animal is up to about 18 mm long. The soft body and the coat are light gray to slightly darker gray. The mantle flap is black and does not cover the apex of the housing. The delimitation of the slit-shaped breathing hole is pulled forward like a finger at the top. From the upper edge of this slit a mantle groove leads to the back (also differentiated from Phenacolimax glacialis).
The hermaphroditic duct (ductus hermaphroditicus) flows into the protein gland in the hermaphroditic genitalia. The egg ladder (spermoviduct) is elongated. The spermatic duct (vas deferens) is short and penetrates the penis sheath in the lower half. The penis is thick, moderately long, and curved; it is surrounded by an additional tissue cover (penis cover). The spermatic duct then penetrates the penis apically. The apex is rounded, the penile retractor muscle attaches apically. There is an erectile tissue inside the penis. In the female part, the free fallopian tube (oviduct) and vagina are approximately the same length, but the fallopian tube can also be longer. But the vagina is much thicker. The spermathec has a very short stem and a comparatively very large bladder that is even longer than the stem. However, the length of the stem varies somewhat. The bladder reaches the lower part of the egg duct. The fallopian tubes and spermathec open into a hemispherical papilla in the upper part of the vagina. The vagina and penis flow together into a comparatively long atrium.
Similar species
The summit glass snail differs from the ear-shaped glass snail ( Eucobresia diaphana ) and the alpine glass snail ( Eucobresia nivalis ) by the smaller mantle lobe that does not cover the apex of the shell. The summit glass snail can only be distinguished from the glacier glass snail ( Eucobresia glacialis ) with certain anatomical certainty. The shell of the summit glass snail has a somewhat narrower skin seam at the lower edge of the mouth. The outer edge of the mouth is slightly curved in the summit glass snail and rounded in the summit glass snail. The differences are blurred in individual cases. The glacial glass snail differs through its significantly thicker, conical penis and its strongly thickened vagina.
Geographical distribution and habitat
The distribution area is limited to the Alps; Switzerland ( Valais , Graubünden ), Germany ( Bavarian Alps ), Austrian, Italy and Slovenia .
The animals live on moist mountain meadows and strips of lawn on rock faces, under stones and scree slopes, mostly above the tree line, in Switzerland between 2000 and 3000 m, in Austria between 1240 and 3140 m above sea level.
Way of life
Lothar Forcart found both juvenile and adult animals on the Riffelberg in August 1943 . From this it can be concluded that the species has a development cycle of several years.
Taxonomy
The taxon was first described in 1884 by Carlo Pollonera in the combination Vitrina pegorarii . Today it is consistently listed in the genus Eucobresia Baker, 1929.
Danger
The species is endangered in Bavaria. According to the IUCN assessment, the species is endangered across the entire range.
literature
- Michael P. Kerney, RAD Cameron, Jürgen H. Jungbluth: The land snails of Northern and Central Europe. 384 pp., Paul Parey, Hamburg & Berlin 1983, ISBN 3-490-17918-8 , p. 155.
Individual evidence
- ↑ a b c d Carlo Pollonera: Monografia del genere Vitrina. Atti della Reale Accademia delle Scienze di Torino, 19 (3): 322-342, 1884 Online at Biodiversity Heritage Library , p. 334.
- ↑ Jürgen H. Jungbluth, Dietrich von Knorre: Trivial names of land and fresh water mollusks in Germany (Gastropoda et Bivalvia). Mollusca, 26 (1): 105-156, Dresden 2008 ISSN 1864-5127 , p. 124.
- ↑ a b Lothar Forcart: Monograph of the Swiss Vitrinidae (Moll. Pulm.). Revue Suisee des Zoologie, 51: 629-678, 1944 Online at Biodiversity Heritage Library , pp. 648-652.
- ↑ Francisco W. Welter-Schultes: European non-marine molluscs, a guide for species identification = identification book for European land and freshwater mollusks. A1-A3 S., 679 S., Q1-Q78 S., Göttingen, Planet Poster Ed., 2012 ISBN 3-933922-75-5 , ISBN 978-3-933922-75-5 (S. 425)
- ↑ AnimalBase: Eucobresia pegorarii (Pollonera, 1884)
- ↑ Fauna Europaea: Eucobresia pegorarii (Pollonera, 1884)
- ↑ MolluscaBase: Eucobresia pegorarii (Pollonera, 1884)
- ↑ Bavaria's Red List of Endangered Mussels and Snails PDF
- ^ Vollrath Wiese: The land snails of Germany. 352 pp., Quelle & Meyer, Wiebelsheim 2014, ISBN 978-3-494-01551-4 (p. 236)
- ↑ The IUCN Red List of Threatened Species: Eucobresia pegoraii