Chondrina

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Chondrina
Western oat grain snail (Chondrina avenacea)

Western oat grain snail ( Chondrina avenacea )

Systematics
Order : Lung snails (pulmonata)
Subordination : Land snails (Stylommatophora)
Superfamily : Pupilloidea
Family : Corn snails (Chondrinidae)
Subfamily : Chondrininae
Genre : Chondrina
Scientific name
Chondrina
Reichenbach , 1828

Chondrina , also less commonly known as oat grain snails , is a genus of the grain snails (Chondrinidae) from the suborder of the land snails (Stylommatophora). About 40 species are currently assigned to the genus. The taxonomic position of some species is still controversial.

features

The housings are cylindrical, spindle-shaped to tower-shaped. They are 3.5 to 14 mm high and 1.8 to 4.1 mm wide. The shell is rather thin-walled and colored horn-colored to dark brown. The cases have 6.25 to 8.5 turns, which are rather slightly curved. The surface is finely striped radially to roughly radially ribbed. With a few exceptions, the mouth edge is usually not thickened. The mouth has up to five palatal lamellae, a basal lamella, two spindle lamellae, an angular lamella, a spiral lamella and a parietal lamella. The angular lamella begins in the upper corner of the palatal rim and extends comparatively deep into the mouth. In addition, special lamellae and edge folds can be developed in individual species. However, the entire mouth reinforcement can also be partially or rarely completely reduced. The mouth rim is bent over. The navel is very narrow or closed.

In the male reproductive system, the penile retractor muscle starts below the middle of the penis. The spermatic duct lies very close to the penis in the lower part of the penis. There is no blind sac (caecum or flagellum) at the tip of the penis. Very rarely is the point where the blind sack attaches to other grain snail genera, which can be interpreted as a rudimentary blind sack. The enlargement of the penis contains a horseshoe-shaped pillar structure (pilaster). The seminal vesicle (spermathek) does not reach the albumin gland (protein gland) and lies next to the egg ladder (spermoviduct). The stem is not covered by the prostate.

The radula has 27 to 50 teeth in a semi-transverse row (including the central tooth), the main tips of which usually do not protrude very clearly from the secondary tips. Two narrow supporting cusps sit on the basal plate of the central tooth, the immediately adjacent posterior teeth have a narrow supporting cusp on the basal plate.

Geographical distribution and habitat

The distribution area of ​​the genus Chondrina extends from Portugal in the west to the Caucasus region in the east. In the north it extends into Central Europe, in the south to North Africa.

The species of the genus Chondrina live exclusively on the surface of rocks (mostly limestone rocks), where they graze the growing lichens.

Taxonomy and systematics

Basically, the taxon was set up as Chondrus by Georges Cuvier as early as 1817 . Cuvier assigned two species to the genus: Bulimus avenaceus Bruguière, 1792 and Bulimus zebra Olivier, 1801. John Edward Gray designated Bulimus zebra as a type of Chondrus Cuvier, 1817 in 1847 (p. 175) .

Ludwig Reichenbach replaced the name with Chondrina in 1828 , because he believed that Chondrus was preoccupied by a genus of algae. This is no longer a reason to propose a substitute name, as the International Rules for Zoological Nomenclature and the International Code of Nomenclature for Algae, Fungi and Plants are independent of each other. Because Chondrina is a substitute name, Bulimus zebra is also the type of Chondrina (see remarks by Francisco Welter Schultes). Several later type species determinations established Bulimus avenaceus Bruguière, 1792 as type species; they are actually invalid. But this would also mean that Chondrina is a younger, objective synonym of Chondrus Cuvier, 1817, a valid and independent genus of the glutton family (Enidae). The name Chondrina has caught on and has since been in constant use with Bulimus avenaceus Bruguière, 1792 as a type species. In order to stabilize the current use of the name Chondrina with Bulimus avenaceus Bruguière, 1792 as a type species, the Commission for Zoological Nomenclature would have to make a decision to fix Bulimus avenaceus Bruguière, 1792 as a type species.

In the Treatise on Recent terrestrial pulmonate molluscs, Part 1 , Anatolij Schileyko divided the genus into two sub-genera, Chondrina (Chondrina) Reichenbach, 1828 and Chondrina (Granopupa) O. Boettger, 1889. Fauna Europaea (and other authors) is not like that followed, but treated Granopupa as an independent genus. The synonymization of the genus Rupestrella Monterosato, 1894 with Chondrina (Granopupa) by the same author, have not been adopted by the following authors and Fauna Europaea.

Currently assigned species:

Chondrina Reichenbach, 1828 is the type genus of the family Chondrinidae Steenberg, 1925 (grain snails) or the subfamily Chondrininae Steenberg, 1925.

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. 116)
  • 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. 65)
  • Bas Kokshoorn: "Resolving riddles and presenting new puzzles in Chondrinidae phylogenetics". Doctoral thesis, Leiden University , ISBN 978-90-71382-56-7 . Open Access
  • Bas Kokshoorn, Edmund Gittenberger: "Chondrinidae taxonomy revisited: new synonymies, new taxa, and a checklist of species and subspecies (Mollusca: Gastropoda: Pulmonata)". Zootaxa, 2539: 1-62, 2010 Preview (PDF; 22 kB).
  • Anatolij A. Schileyko: Treatise on Recent terrestrial pulmonate molluscs, Part 1. Achatinellidae, Amastridae, Orculidae, Strobilopsidae, Spelaeodiscidae, Valloniidae, Cochlicopidae, Pupillidae, Chondrinidae, Pyramidulidae. Ruthenica, Supplement 2 (1): 1-126, Moscow 1998 ISSN  0136-0027
  • 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

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
  2. ↑ Georges Cuvier: Le règne animal distribué d'après son organization: pour servir de base a l'histoire naturelle des animaux et d'introduction a l'anatomie comparée avec figures, dessinées d'après nature. Paris, Déterville: 1817 Online at www.biodiversitylibrary.org (p. 408)
  3. ↑ John Edward Gray: A list of the genera of recent Mollusca, their synonyma and types. - Proceedings of the Zoological Society of London, 15: 129-219, 1847 Online at www.biodiversitylibrary.org .
  4. ^ Heinrich Gottlieb Ludwig Reichenbach: General pocket library of the encyclopedic basic sciences, in their mutual relationships and according to the demands of the time. Zoology or natural history of the animal kingdom. 1. Ribbon. Pp. 1–108, PG Hilschersche Buchhandlung, Dresden 1828. Online at Google Books (p. 93)
  5. ↑ Animal Base: Genus taxon summary for Chondrina Reichenbach, 1828
  6. ↑ Fauna Europaea: Granopupa O. Boettger 1889
  7. ^ Fauna Europaea: Chondrina Reichenbach, 1828

Web links

Commons : Chondrina  - collection of images, videos and audio files