Finely ribbed oat grain snail

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Finely ribbed oat grain snail
Finely ribbed oat grain snail

Finely ribbed oat grain snail

Systematics
Order : Lung snails (pulmonata)
Subordination : Land snails (Stylommatophora)
Superfamily : Pupilloidea
Family : Corn snails (Chondrinidae)
Genre : Chondrina
Type : Finely ribbed oat grain snail
Scientific name
Chondrina arcadica
( Reinhardt , 1881)

The finely ribbed oat grain snail ( Chondrina arcadica ) is a species of the grain snail (Chondrinidae) from the suborder of the terrestrial pulmonary snail (Stylommatophora).

features

The right-hand winding, oblong-conical housing is 5.5 to 7.5 mm high and 2.5 mm wide. It has seven turns, which are comparatively strong on the periphery and all of which are evenly curved. The mouth is elliptical and light brownish inside. The thin and fragile edge of the mouth is sharp and only slightly bent in the columellar and upper palatal areas, it is interrupted in the parietal area. The dentition consists of a strong angular tooth located very far forward, a weaker parietal tooth located deeper in the mouth, two columnar folds and usually three palatal teeth. However, usually only two of them are well developed, the third is weak or completely absent.

The housing is colored dark gray to dark red-brown, the surface does not shine or only weakly. The ornamentation consists of more or less regular, clear growth stripes, which are occasionally reinforced with finely ribs (name!).

The animals are hermaphrodites. In the genital apparatus, the prostate is very long; it is basically just a thin layer of the egg conductor (spermoviduct). The spermatic duct (vas deferens) lies close to the penis opening in the atrium, and the penis and spermatic duct are enclosed by a tissue cover. The spermatic duct leaves the tissue after a short distance and penetrates the epiphallus. This with a small constriction into the penis, which then describes a 180 ° loop. There is no blind bag. The penis retactor muscle starts roughly in the middle of the penis, well in front of the penile loop. In the female tract, the free fallopian tube (oviduct) is very short, while the vagina is very long. The sperm library is a long tube that attaches to the egg ladder. The reservoir (bladder) is elongated, club-shaped, without a diverticulum. The spermathec does not extend to the albumin gland.

Similar species

The shell of the finely ribbed oat grain snail is similar to that of the western oat grain snail ( Chondrina avenacea ), but is a little smaller and more conical in shape. In comparison, the seven whorls are more evenly arched and somewhat more regular and coarsely ribbed. The rye grain snail ( Abida secale ) has a larger end coil than the finely ribbed oat grain snail.

Distribution area of ​​the finely ribbed grain snail in Europe and Western Turkey (according to Welter-Schultes)

Geographical occurrence and habitat

The almost closed distribution area extends from the Czech Republic , Slovakia , Austria , southern Switzerland and north-eastern Italy through Slovenia , Hungary , Romania , the Balkans to Greece and Asia Minor, in the north from the Crimea to the Caucasus . North of this area there are isolated occurrences in southeast Germany, southern Poland, Öland , Gotland and on Lake Vänern (southern Sweden). The species is very rare in Germany and only occurs in a few locations in the Allgäu , Franconia and the eastern Swabian Alb . In Austria the species rises up to 2400 m above sea level, in Bulgaria up to 1900 m.

The animals mostly live in dry, open habitats on calcareous, mostly south-exposed rock surfaces and rock debris in mountain regions. The animals feed on lichens , which they graze on the surface with the radula. Occasionally the western oat grain snail ( Chondrina avenacea ) and the finely ribbed oat grain snail appear sympatric .

Way of life

The animals are usually very local and move little, usually only 7 to 10 cm per day. The animals rarely leave their ancestral habitat. In a very warm and dry summer (summer 1947) Walter Klemm observed a population of Chondrina arcadica that had left its ancestral habitat, a rock face, and crawled eight to ten meters further up beech trunks. After it rained, the entire population crawled back to their ancestral habitat.

Taxonomy

The taxon was established in 1881 by Otto Reinhardt in the form of Torquilla avenacea var. Arcadica . The species has long been described under the more recent synonym Chondrina clienta (Westerlund, 1883); today after Fauna Europaea and MolluscaBase a subspecies of Chondrina arcadica . The fauna Europaea and MolluscaBase divide the species into five subspecies:

  • Chondrina arcadica subsp. abundans (Westerlund, 1894)
  • Chondrina arcadica subsp. bulgarica H. Nordsieck, 1970
  • Chondrina arcadica subsp. caucasica Ehrmann, 1931, Caucasus, Crimea
  • Chondrina arcadica subsp. clienta (Westerlund, 1883)
  • Chondrina arcadica subsp. arcadica (Reinhardt, 1881)

This subspecies is not supported by Welter-Schultes.

Danger

No information is available about the stock situation. In Germany it is classified as extreme rarely .

literature

  • Klaus Bogon: Land snails biology, ecology, biotope protection. 404 p., Natur Verlag, Augsburg 1990, ISBN 3-89440-002-1 (p. 130)
  • Edmund Gittenberger: Contributions to the knowledge of the pupillacea: III. Chondrininae. Zoologische Verhandelingen, 127 (1): 3-267, 1973 ISSN  0024-1652 PDF .
  • 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. 116)

Individual evidence

  1. ↑ Jürgen H. Jungbluth and Dietrich von Knorre: Trivial names of land and freshwater mollusks in Germany (Gastropoda et Bivalvia). Mollusca, 26 (1): 105-156, Dresden 2008 ISSN  1864-5127 , p. 117 (as Chondrina arcadica clienta ).
  2. ↑ Alexandru V. Grossu: Gastropoda Romaniae 2 Subclasa Pulmonata I Ordo Basommatophora II Ordo Stylommatophora Suprafamiliile: Succineacea, Cochlicopacea, Pupillacea. 443 S., Bucharest 1987, pp. 330-336.
  3. ^ 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. 159)
  4. ↑ Igor Balashov, Nina Gural-Sverlova: An annotated checklist of the terrestrial molluscs of Ukraine. Journal of Conchology, 41 (1): 91-109, 2012 PDF (773 KB)
  5. ↑ a b Roman Egorov: Illustrated catalog of the recent terrestrial molluscs of Russia and adjacent regions. Treasure of Russian Shells, Supplement 5. Moscow, 2008 ISSN 1025-2517 PDF (774 KB)
  6. ↑ Walter Klemm: Ecological and biological observations on snails, especially rock snails. Archives for Molluscology, 80 (1/3): 49-56, Frankfurt / M., 1951.
  7. ↑ Otto Reinhardt: A number of Greek snails. Meeting reports of the Gesellschaft Naturforschender Freunde zu Berlin, 1881 (9): 135-137, Berlin 1881 Online at Biodiversity Heritage Library , p. 137.
  8. ↑ Fauna Europaea: Chondrina arcadica (Reinhardt, 1881) (accessed on July 9, 2018)
  9. ↑ MolluscaBase: Chondrina arcadica (Reinhardt, 1881)
  10. ↑ AnimalBase: Chondrina arcadica (Reinhardt, 1881)
  11. ^ Vollrath Wiese: The land snails of Germany. 352 pp., Quelle & Meyer, Wiebelsheim 2014, ISBN 978-3-494-01551-4 (p. 89)