Unnabeled crystal snail

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Unnabeled crystal snail
Unnabeled crystal snail (Vitrea disphana)

Unnabeled crystal snail ( Vitrea disphana )

Systematics
Order : Lung snails (pulmonata)
Subordination : Land snails (Stylommatophora)
Superfamily : Zonitoidea
Family : Crystal snails (Pristilomatidae)
Genre : Vitrea
Type : Unnabeled crystal snail
Scientific name
Vitrea diaphana
( Studer , 1820)

The ungabeled crystal snail ( Vitrea diaphana ) is a snail native to Central Europe - a species of crystal snails (Pristilomatidae) in the suborder of land snails (Stylommatophora).

features

The right-hand winding, quite small case is strongly flattened-conical, the thread is hardly raised in the side view. It has a width of 3.1 to 4.2 mm and a height of 1.8 to 2.1 mm. It has 5½ to 6 tightly wound, regular, slowly increasing turns. The last turn is 1.7 to 2.3 times as wide at the mouth as the previous turn. The mouth is cut almost halfway from the previous turn. When viewed from above, it is transversely elliptical or transversely ovoid, due to the strong incision through the previous turn, oblique crescent-shaped. The mouth is almost perpendicular to the coil axis. For the most part, the edge of the mouth is straight and tapering sharply. However, it can occasionally be slightly increased. The spindle edge is turned over and thickened like a callus. The umbilicus is closed and is often covered by the folded edge of the spindle.

The thin shell is colorless and glassy-translucent. The housing surface is almost smooth and glossy. The growth strips are only clearly visible near the seam. slightly more streaked.

In the hermaphroditic genitalia, the spermatic duct (vas deferens) is very short. It penetrates the penis apically through a simple pore. The penis is moderately long and thick. The penis retractor does not start exactly apically, but somewhat below (“subapical”). In the female part, the free fallopian tube is very short, the vagina relatively long, almost as long as the penis. In the upper part, the perivaginal gland encloses the vagina. The spermathec is rudimentary, often only a very small worm-like appendage. The penis and vagina open into a comparatively long atrium.

Similar species

The ungrounded crystal snail differs from the common crystal snail ( Vitrea crystallina ) and the narrow-billed crystal snail ( Vitrea subrimata ) by its closed umbilicus. The Transylvanian crystal snail ( Vitrea transsylvanica ) is twisted a little further. The edge of the mouth is curved forward on the upper side. Vitrea erjaveci has more tightly wound turns.

Distribution of the species in Europe (according to Welter-Schultes)

Geographical distribution and habitat

The distribution area extends over southern Poland, the Czech Republic, Slovakia, Hungary, western Ukraine, large parts of Romania, Slovenia, Croatia, the Balkans, Austria, Switzerland, the southern half of Germany, the Italian peninsula, and south-east France to the Eastern Pyrenees. In Bulgaria it has been proven up to 1,300 m above sea level.

The ungabeled crystal snail lives in moderately humid locations, under the leaf litter and dead wood, between the rocks and rubble of mountain forests.

Taxonomy

The taxon was first described in 1820 by Samuel Studer as Glischrus (Helix) diaphana . It is generally valued as a valid taxon. It is the type species of the genus Vitrea Fitzinger, 1833.

The earlier subspecies Vitrea diaphana ssp. erjaveci (Brusina, 1870) is now regarded as an independent species. Vitrea subrimata was also regarded by Adolf Riedel in 1957 as a variety of Vitrea diaphana .

Danger

The species is considered threatened with extinction in Rhineland-Palatinate. According to Vollrath Wiese, the extent of the risk is not known.

literature

  • Klaus Bogon: Land snails biology, ecology, biotope protection. 404 p., Natur Verlag, Augsburg 1990, ISBN 3-89440-002-1 , p. 187/87.
  • Malcolm P. Kerney, RAD Cameron, Jürgen H. Jungbluth: The land snails of Northern and Central Europe . Parey-Verlag, Hamburg and Berlin 1983, 384 pp., ISBN 3-490-17918-8 , p. 163

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. 122.
  2. ^ Alexandru V. Grossu: Gastropoda Romaniae 4 Ordo Stylommatophora Suprafam: Arionacea, Zonitacea, Ariophantacea şi Helicacea. 564 S., Bucharest 1983, pp. 97-99.
  3. ^ Adolf Riedel: Revision of the zonitides of Poland (Gastropoda). Annales Zoologici, 16 (23): 362-464, Posen 1957 PDF , pp. 431-433 (including Vitrea subrimata as a variety).
  4. ^ A b 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. 360)
  5. ↑ Samuel Studer: Short list of the conchylia discovered up to now in our fatherland. Naturwissenschaftlicher Anzeiger der Allgemeine Schweizerischen Gesellschaft für die Gesammte Naturwissenschaften, 3 (11): 83–90, 91–94, Bern 1820 Online at ETH Zurich , p. 86 (under crystallina ).
  6. ↑ Vitrea diaphana (Studer, 1820)
  7. ↑ Fauna Europaea: Vitrea diaphana (S. Studer, 1820)
  8. ^ Rosina Fechter, Gerhard Falkner: Molluscs. Mosaik-Verlag, Munich 1990 (Steinbach's Nature Guide 10), 287 pages, ISBN 3-570-03414-3 , page 174.
  9. ↑ MolluscaBase: Vitrea diaphana (S. Studer, 1820)
  10. ↑ MolluscaBase: Vitrea erjaveci (Brusina, 1870)
  11. ^ Vollrath Wiese: The land snails of Germany. 352 pp., Quelle & Meyer, Wiebelsheim 2014 ISBN 978-3-494-01551-4 (p. 197)