Cochlostoma

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Cochlostoma
Small forest snail (Cochlostoma septemspirale)

Small forest snail ( Cochlostoma septemspirale )

Systematics
Subclass : Orthogastropoda
Superordinate : Caenogastropoda
Order : Architaenioglossa
Superfamily : Cyclophoroidea
Family : Forest snails (Cochlostomatidae)
Genre : Cochlostoma
Scientific name
Cochlostoma
Jan , 1830

Cochlostoma is a genus of land-living snails from the family of the forest cap snails (Cochlostomatidae) in the order of the Architaenioglossa ("Old Bandzüngler"). The oldest representatives of the genus Cochlostoma come from the Paleocene ( Palaeogene ).

features

The right-handed, highly conical cases are up to 10 mm high and 5 mm wide. They have 7 to 9.5 more or less strongly curved turns, which increase slowly and regularly. The last turn is usually a bit narrowed. The mouth is rounded and provided with a wide mouth lip. The surface is covered with more or less dense, differently shaped, hollow ribs on the inside. Juvenile cases often have a light keel and a narrow mouth lip. The beginning of the following turn (suture) can follow the keel a little or starts exactly on the keel and makes it disappear, or it also starts a little below (the keel can still be seen). It disappears on the adult turns or there is only a slight irregularity in the turn curve. The mouth is almost round. In adult animals, the edge of the mouth is thickened and more or less curved outwards. He can develop so-called ears in the columellar and parietal area ("auriculation"). The inside of the mouth can be thickened by a thick, white lip. The navel is very narrow and needle-shaped; it can be covered by the bent-over edge of the mouth. The operculum is not calcified and consists of two plates that are connected by a chambered space.

The animals are of separate sex. In some species, a slight sexual dimorphism is also documented in the housing. The males have a somewhat smaller and thicker shell, which is often a little darker in color than the female shell. A reliable differentiation based on the housing is often not possible in individual cases. In the female genital tract, the sex gland is located in the apical part of the housing. It is connected to the uterus / bursa copulatorix complex by the fallopian tubes, which are initially thin and later swollen and tightly looped. The bursa copulatorix is ​​closely attached to the upper end of the uterus; from the outside there is hardly any distinction to be seen. The confluence of the fallopian tube in the uterus is somewhat different in the individual groups of the genus Cochlostoma . In the male genital tract, the usually orange-colored sex gland is also in the apical part of the housing. The thin vas deferens runs along the spindle and enters the prostate, which lies on the dorsal edge of the mantle cavity. The prostate is elongated and flattened with a rounded top. It leads to the right side of the animal's eye and runs out into the spermatic duct which runs to the base of the well-developed penis.

The head tentacles are slender and usually a little darker than the body. The eyes are outside at the base of the antennae.

Geographical distribution, habitat and way of life

The distribution area includes Europe, North Africa and Turkey, with the focus of diversity in the Mediterranean area.

The animals usually live in stony habitats, where they hide in cracks and crevices and under the stones. When it rains, they come out and can now be found on the surfaces of stones and rocks, more rarely on pieces of wood and the bark of living trees. There they graze on algae and lichens and also pick up parts of rotting plants.

The females lay only a few, but relatively large eggs. The development time in the egg is correspondingly long and lasts up to two months.

Taxonomy and systematics

The taxon was established in 1830 by Georg Jan as a subgenus of Cyclostoma Draparnaud, 1801. At first it was ignored and was only "revived" by Kobelt (1902). In 1923, Wilhelm Wenz designated Cyclostoma maculatum Draparnaud, 1805, a younger synonym of Cochlostoma septemspirale (Razoumowsky, 1789) as a type species. Fauna Europaea currently accepts five subgenera:

supporting documents

literature

  • Rosina Fechter and Gerhard Falkner: molluscs. 287 p., Mosaik-Verlag, Munich 1990 (Steinbach's Nature Guide 10) ISBN 3-570-03414-3 (p. 140).
  • Serge Gofas: The systematics of Pyrenean and Cantabrian Cochlostoma (Gastropoda, Cyclophoroidea) revisited . In: Journal of Natural History , 2001, 35 (9): 1277-1369 doi : 10.1080 / 002229301750384301 .
  • 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 (pp. 84/5).
  • 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
  • Wilhelm Wenz: Gastropoda extramarina tertiaria. In: Carl Diener (Ed.), Fossilium catalogus, 1 Animalium , 17 + 23: 1-1862, Berlin 1923 Online at www.biodiversitylibrary.org (p. 1773ff.).

Individual evidence

  1. ^ Wilhelm Kobelt: The animal kingdom. A compilation and identification of the recent animal forms. 16. Delivery. Mollusca. Cyclophoridae. SI-XXXIX, pp. 1–662, Berlin, Friedländer 1902 [1] (p. 488)
  2. ↑ Fauna Europaea - Cochlostoma Jan, 1830
  3. ↑ Olivier Gargominy, Theo Ripken: Données nouvelles sur les mollusques (Mollusca, Gastropoda) du Parc national du Mercantour (France) New data on the molluscs (Mollusca, Gastropoda) of the Mercantour National Park (France). MalaCo, 3: 109-139, 2006 PDF ( Memento of the original dated December 30, 2011 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. @1@ 2Template: Webachiv / IABot / www.journal-malaco.fr
  4. ↑ Hartmut Nordsieck: Description of a new Cochlostoma species from Italy, with revision remarks on the Cochlostoma species of the Apennine Peninsula (Gastropoda, Caenogastropoda, Architaenioglossa, Cochlostomatidae). Conchylia, 41: 13-21, 2011.

On-line

Web links

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