Mountain glass snail

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Mountain glass snail
Mountain glass snail (Hessemilimax kotulae)

Mountain glass snail ( Hessemilimax kotulae )

Systematics
Subordination : Land snails (Stylommatophora)
Superfamily : Limacoidea
Family : Glass snails (Vitrinidae)
Subfamily : Vitrininae
Genre : Hessemimilax
Type : Mountain glass snail
Scientific name of the  genus
Hessemimilax
Schileyko , 1986
Scientific name of the  species
Hessemilimax kotulae
( Westerlund , 1883)

The mountain glass snail ( Hessemilimax kotulae , syn .: Semilimax kotulae ) is a "half- nudibranch " from the family of glass snails (Vitrinidae), which is counted among the land snails (Stylommatophora). The animals can no longer completely withdraw into the small housing. Hessemilimax kotulae is the type and only species of the genus Hessemilimax Schileyko, 1986.

features

The right-hand wound housing is very flat ear-shaped or broadly ovoid. In the side view, it is very flat and the thread cannot be seen, even slightly deepened. It has a width of 4.3 to 6 mm. There are 1.75 to 1.8 turns; the last turn widens very quickly. At the mouth, the end turn takes up about three quarters of the total diameter. The turns are very flat at the top, so the seam is only weakly pronounced. The turns are open on the underside, so there is basically no underside of the housing. The mouth is very crooked or almost horizontal. The skin seam on the basal and spindle edge of the mouth is very wide. It spirals very far back. This means that all turns are visible.

The shell is very thin and fragile. It is translucent and colorless to slightly greenish. The protoconch is essentially smooth with many regularly arranged rows of very small dimples. The surface of the Teleoconch has very fine strips of growth and weak wrinkles in places, otherwise the surface is smooth and very shiny.

The soft body is uniformly gray, the jacket in front of the housing is very wide; it extends down to the neck. When stretched out, the animal is 12 to 15 mm long. It can no longer withdraw into the housing. The long and narrow mantle flap covers the apex or almost the entire housing. A jacket channel runs from the slit-shaped breathing opening to the back. The sole is divided into three parts in the longitudinal direction. The outer fields are colored darker than the middle field. The radula has 47 elements per transverse row, the middle number is three-pointed, the posterior teeth two-pointed and the marginal tooth single-pointed.

In the hermaphroditic genitalia, the protein gland (albumin gland) is comparatively small and spherical. The egg sperm duct (sperm duct) is elongated, the lower part is inflated. In the male tract of the hermaphroditic reproductive system, the spermatic duct is moderately long. It runs under the penis sheath and along the penis and penetrates the penis subapically. The penis is comparatively long and slim. The penile retractor muscle attaches subapically next to the confluence of the seminal duct on the penis. The other end of the muscle begins at the diaphragm, runs in front of the right optic nerve and under the right ocular retractor muscle.

In the female part of the genital system, the free fallopian tube (oviduct) is short. The vagina is comparatively very short, since the spermathec opens into the wide atrium almost at the same level as the vagina. The spermathec has a short stalk that is thick-walled and broadened at the base. The bladder is egg-shaped.

The sarcobelum (also called the stimulator) is a large blind sac-like structure that is divided into two sections by a strong constriction. The penis, sarcobelum and vagina flow into the long atrium at about the same height.

Similar species

The housing is similar to that of the wide- mouthed glass snail ( Semilimax semilimax ), but the latter has a raised, albeit very flat thread. On the underside, the skin seam is wider and extends much further back in a spiral. The surface of the shell of the mountain glass snail is smoother and shinier than the wide mouthed glass snail ( Semilimax semilimax ).

Distribution of the species (according to Welter-Schultes, 2012)

Geographical distribution and habitat

The distribution area of ​​the species extends from the Swiss Alps (Wallis, Waadt), over the Bavarian and Austrian Alps with gaps to the Carpathians. There are isolated occurrences in the Bohemian Forest, Fichtel Mountains, Ore Mountains and Sudetes, as well as in the Lysa Gora Mountains in central Poland.

The animals live very hidden in cool, damp, shady locations in forests under stones, in damp moss and litter. In Switzerland, the species rises to 2,600 m above sea level. There it lives under the dwarf bushes in the moss or on alpine meadows under stones. It is rarely found in the Alps below 1,300 m. In the low mountain ranges it occurs from around 500 m to the highest elevations.

Way of life

Little is known about the life cycle. Lothar Forcart found (only) adult specimens in Switzerland in August and September, which would indicate an annual cycle.

Taxonomy

The taxon was set up in 1883 by Carl Agardh Westerlund as Vitrina Kotulae . It is the type species and only species of the genus Hessemilimax Schileyko, 1986. While MolluscaBase recognizes the genus Hessemilix as valid, Welter-Schultes lists the species under the genus Semilimax Stabile, 1859.

Danger

According to Vollrath Wiese, the degree of risk is unknown. It does not seem to be endangered in Saxony . In Bavaria it is threatened with extinction and in Austria it is considered endangered. In Switzerland, however, the species is not endangered. According to the IUCN , the population of the species is not endangered.

literature

  • Michael P. Kerney, RAD Cameron & Jürgen H. Jungbluth: The land snails of Northern and Central Europe. 384 pp., Paul Parey, Hamburg, p. 153.

Individual evidence

  1. ↑ 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.
  2. ↑ 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. 66-669.
  3. ↑ Folco Giusti, Viviana Fiorentino, Andrea Benocci, Giuseppe Manganelli: A Survey of Vitrinid Land Snails (Gastropoda: Pulmonata: Limacoidea). Malacologia, 53 (2): 279-363, 2011 Academia.edu , p. 336.
  4. ↑ a b c d 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., Planet Poster Ed., Göttingen 2012, ISBN 3-933922-75-5 , ISBN 978-3-933922-75-5 (p. 430)
  5. ↑ Carl Agardh Westerlund: Malacological Miscelles. Yearbooks of the German Malacoological Society 10: 51-72. Frankfurt am Main, 1883 Online at Biodiversity Heritage Library , p. 54.
  6. ↑ Anatolij A. Schileyko: Treatise on Recent Terrestrial Pulmonate Molluscs Part 11 Trigonochlamydidae, Papillodermidae, Vitrinidae, Limacidae, Bielziidae, Agriolimacidae, Boettgerillidae, Camaenidae. Ruthenica, Supplement 2 (11): 1467-1626, Moscow 2003 ISSN  0136-0027 , p. 1485.
  7. ↑ MolluscaBase: Hessemilimax kotulae (Westerlund, 1883) and Hessemilimax Schileyko, 1986
  8. ↑ AnimalBase: Semilimax kotulae (Westerlund, 1883)
  9. ^ Vollrath Wiese: The land snails of Germany. 352 pp., Quelle & Meyer, Wiebelsheim 2014 ISBN 978-3-494-01551-4 (p. 233).
  10. ↑ mountain pellucida (Semilimax kotulae (Westerlund, 1883)) by Katrin Schniebs. June 20, 2019 release
  11. ↑ The IUCN Red List of Threatened Species: Semilimax kotulae

annotation

  1. ↑ Lothar Forcart even expressly writes that a vagina is missing.