Flat gloss snail

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Flat gloss snail
Flat shining snail (Mediterranea depressa)

Flat shining snail ( Mediterranea depressa )

Systematics
Order : Lung snails (pulmonata)
Subordination : Land snails (Stylommatophora)
Superfamily : Zonitoidea
Family : Gloss snails (Oxychilidae)
Genre : Mediterranea
Type : Flat gloss snail
Scientific name
Mediterranea depressa
( Sterki , 1880)

The flat gloss snail ( Mediterranea depressa , syn .: Oxychilus depressus ) is a snail native to Central Europe - species of the gloss snail (Oxychilidae) in the suborder of the land snail (Stylommatophora).

features

The right-handed case of surfaces glass snail is as the name suggests, strongly flattened (-kegelig). In the side view, the thread is barely visible, the apex slightly arched. It has a width of 6.5 to 8 mm and a height of 3 to 4.5 mm. In the adult stage 4½ to 5 turns are formed, which expand slowly and regularly. They are strongly flattened on the top and only form a flat seam. The periphery is more rounded. The last turn increases barely noticeably towards the mouth and decreases very little. The navel is deep and very narrow. When viewed from above, the mouth is somewhat flattened, elliptical or ovoid, apart from the incision of the previous turn, and slightly crooked. The mouth edge is straight and pointed.

The skin is whitish to light yellowish and translucent. The surface is glossy and has fine and weak, regular growth stripes, somewhat clearer towards the navel.

The soft body varies in color from very light gray to blue-gray. Glands in the coat of juvenile animals appear through the shell as red spots. In the hermaphroditic genitalia, the vas deferens is quite long and enters the epiphallus apically. The epiphallus is short and lies against the penis before the transition into the penis or is connected to the penis by a thin membrane. The penis is very distended slightly above the middle. Inside, the penis has hook-shaped or thorn-shaped appendages and complex folds. The penis is surrounded by a sheath in the proximal part. The penile retractor muscle attaches apically to the penis, at the apex of the loop that is formed by the epiphallus and penis. The epiphallus is only about half the length of the penis. The free fallopian tube (oviduct) and the vagina are roughly the same length. The perivaginal gland at the junction of the vagina and free discharger is well developed. The stem of the spermathec is short, the bladder (reservoir) spherical. It lies against the lower part of the egg ladder. There is no atrium. The male and female outlets open separately into a shallow pit.

Similar species

The deep and very narrow umbilicus is narrower than that of the other European Oxychilus species. The thread of the smooth gloss snail ( Morlina glabra ) is higher and the turns on the top are slightly more convex.

Distribution area of ​​the species (according to Welter-Schultes)

Geographical distribution and habitat

The distribution area extends over Central Europe, the Eastern Alps and the Balkans to Greece. There are two isolated occurrences in the Italian western Alps. In Germany there are isolated locations in the Black Forest, the Franconian Jura, the Bavarian Forest, the Thuringian Forest and the Ore Mountains. In Austria the occurrences are also very scattered. The species is a little more common in the Carpathian Mountains.

The species prefers to live in moderately humid habitats in forests, in scree and between rocks, in open grass slopes with individual bushes or trees, also above the tree line. It lives underground in soils rich in humus and detritus. In Bulgaria it is often found in caves (entrances). It prefers calcareous soils, but silicate soils are tolerated. In Switzerland (Engadin) and Bulgaria it rises up to 2,600 m above sea level.

Taxonomy

The taxon was first described by Victor Sterki in 1880 as Hyalina depressa . The taxon is generally recognized, but the genus is controversial. In the conservative systematisation it is classified as Oxychilus depressus (Sterki, 1880) in the genus Oxychilus Fitzinger, 1833. Riedel (1969), Grossu (1983) and Kerney et al. (1983) put it as Oxychilus (Riedelius) depressus (Sterki, 1880) to the subgenus Oxychilus (Riedelius) Hudec, 1961. However, since the type species from Oxychilus (Riedelius) Hudec is to be put to Mediterranea , Schileyko (2003) suggested the new one Name (in reality a new scientific name) Riedeloconcha before, with Hyalina depressa Sterki as type species. However, since Hyalina depressa Sterki belongs well to the genus Mediterranea Clessin, 1880, these genera are more recent, subjective synonyms of Mediterranea . The MolluscaBase divides the family Oxychilidae into several subfamilies. In this system, Mediterranea is in the nominate subfamily Oxychilinae.

Danger

The species is not common anywhere, the occurrences are very dispersed and there is little connection between the individual populations. It is considered to be critically endangered in Germany and Austria. It is also endangered in Switzerland and Saxony. On the other hand, it is assessed by the IUCN as safe for the entire distribution area.

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. 123.
  2. ↑ a b c 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. 381)
  3. ↑ Victor Sterki: Hyalina depressa n. Sp. Bulletin of the German Malacoological Society, 12 (10): 104–105. Frankfurt am Main, 1889 Online at Biodiversity Heritage Library
  4. ↑ Oxychilus depressus (Sterki, 1880)
  5. ^ Rosina Fechter, Gerhard Falkner: Molluscs. Mosaik-Verlag, Munich 1990 (Steinbach's Nature Guide 10), 287 pp., ISBN 3-570-03414-3 , p. 182.
  6. ^ Alexandru V. Grossu: Gastropoda Romaniae 4 Ordo Stylommatophora Suprafam: Arionacea, Zonitacea, Ariophantacea şi Helicacea. 564 pp., Bucharest 1983, pp. 136-138 (as Oxychilus (Riedelius) depressus ).
  7. ^ MP Kerney, RAD Cameron, Jürgen H. Jungbluth: Die Landschnecken Northern and Central Europe . Parey-Verlag, Hamburg and Berlin 1983, 384 pp., ISBN 3-490-17918-8 , p. 172 (as Oxychilus (Riedelius) depressus )
  8. ↑ Adolf Riedel: The sub-genera Morlina AJ Wagner and Riedelius Hudec of the genus Oxychilus Fitzinger (Gastropoda, Zonitidae). Annales Zoologici, 27 (6): 91-130, 1969 PDF
  9. ↑ Anatolij A. Schileyko: Treatise on Recent Terrestrial Pulmonate Molluscs Part 10 Ariophantidae, Ostracolethidae, Ryssotidae, Milacidae, Dyakiidae, Staffordiidae, Gastrodontidae, Zonitidae, Daudebardiidae, Parmacellidae. Ruthenica, Supplement 2 (10): 1307-1488, Moscow 2003, ISSN  0136-0027 , p. 1429/30 (as Riedeliconcha depressa ).
  10. ↑ MolluscaBase ": Mediterranea depressa (Sterki, 1880)
  11. ↑ Fauna Europaea: Mediterranea depressa (Sterki, 1880)
  12. ^ Vollrath Wiese: The land snails of Germany. 352 p., Quelle & Meyer, Wiebelsheim 2014 ISBN 978-3-494-01551-4 (p. 188/89)
  13. ↑ Katrin Schniebs, Heike Reise, Ulrich Bößneck: Red List of Mollusks of Saxony. State Office for Environment and Geology, Free State of Saxony, 2006. PDF
  14. ↑ IUCN Red List of Threatened Species: Mediterranea depressa