Cochlostoma crassilabrum

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Cochlostoma crassilabrum
Systematics
Order : Architaenioglossa
Superfamily : Cyclophoroidea
Family : Forest snails (Cochlostomatidae)
Genre : Cochlostoma
Subgenus : Obscurella
Type : Cochlostoma crassilabrum
Scientific name
Cochlostoma crassilabrum
( Dupuy , 1849)

Cochlostoma crassilabrum ( syn. Cochlostoma conicum ) is a species of snail from the family of the forest snail (Cochlostomatidae) in the order Architaenioglossa ("old bandworm")that lives on land.

features

The right-hand winding, cone-shaped case is 10.0 to 13.5 mm high and 4 to 5 mm wide. It has 7 to 8.5 slightly curved turns. The first turns are slightly edged at the periphery, but the edge is completely covered by the following turn. The outer line is almost straight. The last turn is slightly narrowed at the mouth. The first half of the embryonic turn shows only very weak wrinkles, the following 1.5 turns show very fine axial ribs. The following turns then have very strong and irregular ribs (approx. 8 to 9 ribs per millimeter). From about the fourth and fifth turn the ribs become denser; there are now about 12 to 13 ribs per millimeter. The ribs are not thickened at the seam. The mouth has a pear-shaped outline when viewed from the front. The mouth edge is thickened and bent outwards like a collar, but without a clear ring-like reinforcement on the inner edge. The mouth edge is clearly drawn out to "ears" on the spindle side and indistinctly on the parietal edge. The edge of the mouth is also tilted slightly inwards at the edge of the spindle. The mouth edge is white.

The case is colored light brown and has a number of brown spots below the seam. A band with brown spots and whitish intervals runs above the seam and initially approximately below the periphery, which continues on the last turn on the periphery. Another brown band runs around the navel. The whitish intervals in the brown patch band are formed by light sections of the ribs crossing the bands.

A population in the area of Eaux-Bonnes ( Département Pyrénées-Atlantiques ) in the Central Pyrenees differs from the typical specimens of the species by more intense colors. The base color of the case is a little lighter and the periumbilical band is narrower. They have been treated by some authors as a separate species, Cochlostoma mabillianus (Saint-Simon, 1869). The electrophoresis data does not support this. It is just a local variant of Cochlostoma crassilabrum .

In the direction of the Western Pyrenees (Basque Country) the size of the animals decreases on average. The ribs are somewhat stronger and less numerous per millimeter (seven to eight ribs). In addition, the postembryonic convolutions are slightly darker in the basic color. For this form, de Folin and Bérillon (1877) introduced the taxon Pomatias hidalgoi var. Laburdensis . Wilhelm Kobelt treated this taxon as a separate species. This name was unnecessarily replaced by Pomatias berilloni by Fagot (1880) , as he considered the name to be a synonym for Cochlostoma lapurdensis Fagot, 1880. However, this is not the case and Pomatias berilloni Fagot, 1880 is therefore a more recent objective synonym of Pomatias laburdensis de Folin & Bérillon, 1877. However, the differences between Cochlostoma crassilabrum Dupuy, 1849 and Pomatias laburdensis de Folin & Bérillon, 1877 are gradual and also With the help of electrophoresis, no differences could be determined that would justify a possible separation of the populations of the Basque western Pyrenees from Cochlostoma crassilabrum as a species or subspecies.

Another morph, which is only known from a collection from the 19th century, comes from Gerde (near Bagnères-de-Bigorre , Hautes-Pyrénées , France). This population is characterized by a lower, more compact housing, the weak ribs and the lighter color from the surrounding populations. They were called var. Jetschini by Wagner (1897) . It was later formally treated as a subspecies. Serge Gofas' attempts to find this morph again failed.

Similar species

Cochlostoma crassilabrum is very similar to the dark forest snail ( Cochlostoma obscurum ). Some authors treat both taxa as synonyms. Serge Gofas found the following differences, however: Cochlostoma crassilabrum is slightly larger on average (10.0 to 13.5 mm versus 10.0 to 11.0 mm). The edge of the mouth is somewhat wider and thicker, has a lighter white, and is somewhat "eyed" in the spindle area, only weakly "eyed" in the parietal area. The end turn is slightly narrowed.

Geographical distribution and habitat

The distribution area stretches from the Eastern Pyrenees to the eastern part of the Cantabrian Mountains.

The animals live between limestone cliffs with a preference for shaded surfaces of smaller blocks in the shade of large blocks. In the Basque Country, the animals can often be found in the grass at the foot of larger limestone blocks. The species occurs there from about 500 to about 1500 m above sea level.

Taxonomy

The taxon was described by Dominique Dupuy in 1849 as Pomatias crassilabrum . He described the species in detail in 1851. Wilhelm Kobelt transferred it to the genus Cochlostoma , subgenus Obscurella Clessin, 1889. Some authors treat the species as a synonym for the dark forest snail ( Cochlostoma obscurum ). Gofas (2001) performed allozyme electrophoresis on the species. He found a calculated genetic distance of 0.18 to 0.21 between the two disjoint populations of Cochlostoma obscurum in Burgundy and the foothills of the Pyrenees. In contrast, the genetic distance between the foothills of the Pyrenees and the high-mountain Pyrenees (= Cochlostoma crassilabrum ) was significantly greater at 0.32 to 0.42 and approached the genetic distance of 0.45 to 0.67 for the sympatric species Cochlostoma partioti and Cochlostoma crassilabrum . In addition, the high mountain populations (= C. crassilabrum ) are significantly larger on average. Since the two populations Cochlostoma crassilabrum and Cochlostoma obscurum do not occur sympatric , the ultimate proof of the independence of the two taxa is still pending.

Serge Gofas lists the following synonyms for Cochlostoma crassilabrum :

  • Pomatias mabillianus Saint-Simon, 1869
  • Pomatias frossardi Bourguignat in Frossard, 1870
  • Pomatias spelaeus Fagot, 1876
  • Pomatias hidalgoi var. Laburdensis de Folin and BERILLON, 1877
  • Pomatias berilloni Fagot, 1880
  • Pomatias fagoti Bourguignat in Fagot, 1880c
  • Pomatias ventricosus Salvañá, 1887
  • Pomatias isoicus Fagot, 1889
  • Pomatias isabanus Fagot, 1889
  • Pomatias filicium Fagot, 1889
  • Pomatias bearnicus Fagot, 1891
  • Pomatias saulcyi Fagot, 1891
  • Pomatias daralli Locard, 1894
  • Pomatias angustus Locard, 1894
  • Pomatias (Rhabdotakra) berilloni var. Kobelti Wagner, 1897

supporting documents

literature

  • Serge Gofas: The systematics of Pyrenean and Cantabrian Cochlostoma (Gastropoda, Cyclophoroidea) revisited. Journal of Natural History, 35 (9): 1277-1369, 2001 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 (p. 64)
  • 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. ↑ Alexandre Guillaume Léopold de Folin, Ferdinand Bérillon: Contribution à la faune malacologique de la région extrême S.-O. de la France. Bulletin de la Société de Borda à Dax, 2 (2): pp. 199–210, Dax 1877 (online at gallica.bnf.fr) (p. 202)
  2. ^ 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 Online at www.biodiversitylibrary.org (p. 498)
  3. ↑ Serge Gofas: The systematics of Pyrenean and Cantabrian Cochlostoma (Gastropoda, Cyclophoroidea) revisited. Journal of Natural History, 35 (9): 1277-1369, 2001
  4. ↑ Dominique Dupuy: Catalogus extramarinorum Galliae testaceorum ... brevioribus specierum nondum descriptorum diagnosibus. 4 pp., Paris, self-published.
  5. ↑ Dominique Dupuy: Histoire Naturelle des Mollusques terrestres et d'eau douce qui vivent en France. Volume 5, pp. 459-594, plates 22-24, Paris 1851 [1] (p. 511).

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