Wood snail

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Wood snail
Wood snail (Macularia sylvatica)

Wood snail ( Macularia sylvatica )

Systematics
Subordination : Land snails (Stylommatophora)
Superfamily : Helicoidea
Family : Schnirkelschnecken (Helicidae)
Subfamily : Murellinae
Genre : Macularia
Type : Wood snail
Scientific name
Macularia sylvatica
( Draparnaud , 1801)

The forest Schnirkelschnecke ( macularia sylvatica , syn. Cepaea sylvatica , in the misspelling Cepaea sylvatica ), also Cepaea sylvatica or Fleckenstreifige Bänderschnecke is a living on the land snails - kind from the family of Helicid (Helicidae) that the for submission Land snails (Stylommatophora) is expected. According to new molecular genetic studies, it no longer belongs to the genus of the cepaque snails .

features

The right-hand wound case measures 18–25 mm (rarely up to 28 mm) in width and 12–16 mm in height. Above the tree line, the animals are generally smaller and the shells only reach a diameter of 16 to 17 mm. The housing is slightly pressed, spherical and has 5 to 6 turns that grow regularly. In adult animals, the mouth drops slightly from the axis of the coil. The lip in the mouth is brownish at the navel, light to whitish towards the seam. In the spindle area, the lip is callous-like, a characteristic of the species. The lower end of the spindle callus is relatively high, the edge of the mouth does not converge towards the navel with the inner lip-spindle edge. In juvenile specimens, the umbilicus is open, in adult animals it is usually covered by the edge of the mouth.

The surface is coarse and irregularly striped as well as fine spirally striped. The basic color of the housing is whitish or yellowish. Of the total of five bands, the three lower bands are usually comparatively wide and complete, while the two upper bands are very narrow and / or broken up into rows of spots. But also the three lower bands can be broken up into rows of spots in some populations. It is difficult to determine in albinotic specimens in which the banding is completely absent.

Creeping on a horizontal plane, the soft body reaches a length of 40 to 50 millimeters. The head, neck and back are gray-brown to blackish, while the sides are yellowish-white. A white line runs on the back, beginning between the two eye carriers, which clearly stands out against the dark basic color of the body. The sole of the foot is yellowish white, the end of the foot is keeled at an obtuse angle. The crescent-shaped, curved pine with truncated ends is dark horn-brown in color. It is 1.4 to 1.7 mm wide and 0.7 to 0.9 mm high, and is provided with three to four strips that protrude from the upper and lower edges. The radula (rasp tongue) is 5.2 mm long, 1.9 mm wide and has 144 to 149 transverse rows of teeth. There are 41 to 44 teeth in a half-transverse row: a single-pointed central tooth, the slightly larger, asymmetrical side teeth are initially also single-pointed when viewed from the central tooth. From the 10th to the 12th tooth, a small secondary tip appears on the outside, which becomes larger with teeth that follow further outwards. At the same time, by dividing the original tip, another small tip is formed on the inside. At the outer edge, the outer secondary tip can also split, so that four-pointed teeth can appear there.

Pine of the wood snail (after Hesse, 1920)
Radula the wood snail (after Hesse, 1920)

In the reproductive system, the hermaphroditic gland is compactly kidney-shaped, the 8 to 12 mm long hermaphroditic duct is very strongly laid in short S-shaped folds. The mostly translucent albumin gland (or protein gland) is horn yellow or dark lemon yellow. It is narrow tongue-shaped and 15 to 24 mm long. The spermoviduct is 20 to 35 mm long, translucent, whitish and gelatinous. The free fallopian tube is shorter than the vagina. The spermathec is small round with a long, thin stem. This is clearly thickened near the base. About halfway along the length of the stalk, a thin diverticulum branches off, which is more than twice as long as the two halves of the spermathec with stalk. The seminal vesicle measures 2 to 4 mm in diameter. The thick, club-shaped arrow sack, which is 4 to 6 mm long, rises from the front edge of the vagina. It contains a slightly curved to almost straight love arrow 4.5 to 5 mm in length. It has a short neck, a long blade with four longitudinal ridges and a crown with 10 to 15 longitudinal ribs. The four symmetrically arranged longitudinal ridges on the blade widen outwards and gradually narrow towards the tip. Two opposite longitudinal strips are provided in the middle with a flat, very narrow longitudinal groove. This longitudinal channel is missing in the two other opposite longitudinal strips. Behind the base of the arrow sac arise the glandulae mucosae, each with a short stalk of 2 to 4.5 mm (rarely up to 7 mm). There are usually about 4 branches on each gland (rarely more: up to six, or less: up to 3). The branches are 13 to 23 mm long.

Genital apparatus of the wood snail (after Hesse, 1920)
Love arrow of the wood snail (after Hesse, 1920)

In the male genital tract, the penis is relatively short at 5 to 8 mm. It has two ring-shaped bulges at the transition to the epiphallus. The slender epiphallus is about as long as the penis. The penile retractor muscle inserts on the outer ring bulge, roughly in the middle of the male organ (penis and epiphallus). At the entrance of the spermatic duct into the epiphallus, a very long and thin flagellum branches off, which is about three times as long as the penis and epiphallus together. The spermatic duct is comparatively short and straight.

The chromosome set is 2n = 50.

Similar species

The shape of the shell is very similar to that of the garden banded snail ( Cepaea hortensis ). However, it differs in size. The garden tapestry is significantly smaller on average, and on average also has slightly fewer turns. The streaking of the ribbed banded snail is much coarser and somewhat more irregular. A characteristic of the wood snail is a callus-like thickening of the mouth lip in the spindle area. The upper and lower edges of the mouth run approximately parallel, in the ribbed banded snail ( Caucasotachea vindobonensis ) the upper and lower mouth edge converge towards the umbilical area. The mouth lip is in this type and in the grove snail ( Cepaea nemoralis brownish) in Cepaea hortensis whitish.

The love arrow of the ribbed banded snail ( Caucasotachea vindobonensis ) is significantly shorter at 3 to 3.5 mm, which affects the blade, neck and crown. The love arrow is almost the same thickness, in the upper blade area it is even a little thicker on the ribbed banded snail. One pair of the blade strips is wider on the outside than the other pair of the longitudinal strips. The love arrow of the garden banded snail ( Cepaea hortensis ), which is similar in size and cross-section, has a more constricted neck and a shorter crown. The much larger love arrow of the grove banded snail ( Cepaea nemoralis ), whose longitudinal ridges do not widen on the blade at the outer edge of the edge, is more different. In addition, an opposing pair of the longitudinal strips is slightly shorter than the other pair of longitudinal strips, the greatest thickness is achieved in the middle of the blade.

In the genital tract, in both Cepaea nemoralis and Cepaea hortensis, the diverticulum on the stem of the spermathec is very short to rudimentary. In Caucasotachea vindobonensis , the branches of the glandulae mucosae (mucous glands) lie close together and are also less branched. In Macularia sylvatica , on the other hand, the glandulae mucosae are branched several times, the branches protrude in tufts. The arrow sack is also shorter due to the shorter love arrow. The flagellum in the male genital tract is also significantly shorter in this species in relation to the penis / epiphallus length.

The chromosome set is 2n = 44 in the grove cepid snail and the garden cone snail, the chromosome number is 2n = 50 in the ribbed cepaque snail.

Distribution of the wood snail in Europe (according to Welter-Schultes, 2012)

Geographical distribution and habitat

The species is native to the Swiss, French and northwest Italian Alps and the Jura in France and Switzerland as well as on the Upper Rhine near Schaffhausen. It used to occur on the German side of the High Rhine near Waldshut and in the Upper Rhine Valley to Karlsruhe and Worms. A final record from Baden-Württemberg, however, comes from 1954. Since then it has been lost and is considered extinct. Paul Hesse examined specimens that he had received from near Waldshut in 1920 . Some specimens from the Upper Rhine near Schaffhausen were settled in the English Garden of Landsberg am Lech in 1878 . What became of this colony is unclear. Cepaea sylvativa is not on the Red List of Endangered Animals and Vascular Plants in Bavaria. So the colony is probably extinct again.

The wood snail lives in light mountain forests and moist meadows near the forests, between limestone pebbles and blocks between 500 and 2,500 m altitude ( Valais ). It occurs almost exclusively on chalky soils and requires high humidity.

Way of life

Little is known about the way of life of the species. The animals feed on fresh greenery, but also on lichens. According to Ewald Frömming, self-fertilization does not occur in the wood snail.

Taxonomy

The taxon was established in 1801 by Jacques Philippe Raymond Draparnaud . The genus Cepaea is / was divided into sub-genera by some authors. In this sub-genus, which is also represented by Fauna Europaea, the wood snail is placed in the sub-genus Cepaea (Austrotachea) Pfeffer, 1930. In 2015/16, however, molecular genetic studies revealed that the genus Cepaea is polyphyletic in its previous version. Cepaea vindobonensis was transferred to the genus Caucasotachea Boettger, 1909, Cepaea sylvatica to the genus Macularia . The genus Cepaea is monophyletic again with only two more recent species (grove cepaea, garden cape snail and some fossil species) .

Danger

The species is extinct or missing in Germany. According to the IUCN assessment, however, the species is not endangered overall.

literature

  • Bogon, Klaus 1990: Land snails biology, ecology, biotope protection. 404 p., Natur Verlag, Augsburg ISBN 3-89440-002-1 (p. 380/1)
  • 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. 283)

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. 129.
  2. ^ Rosina Fechter and Gerhard Falkner: Molluscs. 287 pp., Mosaik-Verlag, Munich 1990 (Steinbach's Nature Guide 10) ISBN 3-570-03414-3 (p. 240)
  3. ^ Molluscs of Central Europe: Cepaea sylvatica
  4. ↑ a b Manfred Colling, Gerhard Falkner, Klaus Groh, Jürgen H. Jungbluth, Matthias Klemm, Hans-Jörg Niederhöfer, Wolfgang Rähle, Günter Schmid: Red List and Species Directory of Snails and Mussels in Baden-Württemberg 2008 PDF
  5. ↑ a b c d e Paul Hesse: Iconography of the land and freshwater mollusks with excellent consideration of the European species not yet shown by EA Rossmässler, continued by Dr. W. Kobelt. New episode, 23: 5 + 262 pp., Pl. 631–660, Berlin & Wiesbaden, CW Kreidel's Verlag 1920 Online at www.biodiversitylibrary.org .
  6. ↑ a b J. JB Gill, AJ Cain: The karyotype of Cepaea sylvatica (Pulmonata: Helicidae) and its relationship to Those of C. hortensis and C. nemoralis. Biological Journal of the Linnean Society, 14 (3-4): 293-301, 1980 doi : 10.1111 / j.1095-8312.1980.tb00110.x
  7. ↑ 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. 606)
  8. ^ Günter Schmid: Mollusks introduced or released in Baden-Württemberg. Annual books of the Society for Natural History Württemberg, 158: 253-302, [2002] 2003.
  9. ↑ Jürgen Jungbluth, Dietrich von Knorre: Red list of internal mollusks [snails (Gastropoda) and mussels (Bivalvia)] in Germany. 6. Revised and extended version 2008. Communications of the German Malacoological Society, 81: 1–28, Frankfurt a. M., May 2009 PDF (p. 8)
  10. ↑ Red List of Endangered Animals and Vascular Plants Bavaria's Short Version 185 S., Munich 2005 PDF ( Memento of the original from March 4, 2016 in the Internet Archive ) Info: The archive link was automatically inserted and not yet checked. Please check the original and archive link according to the instructions and then remove this notice. @1@ 2Template: Webachiv / IABot / www.bestellen.bayern.de
  11. ↑ AnimalBase: Cepaea sylvatica (Draparnaud, 1801)
  12. ^ Ewald Frömming: Biology of the Central European Landgastropods. 404 pp., Duncker & Humblot, Berlin 1954 (p. 322)
  13. ^ Jacques Philippe Raymond Draparnaud: Tableau des mollusques terrestres et fluviatiles de la France. 2 + 116 pp., Montpellier & Paris, Renaud; Bossange, Masson & Besson 1801 Online at www.biodiversitylibrary.org (p. 79).
  14. ↑ a b Hartmut Nordsieck: On the systematics of the genus Cepaea Held (Gastropoda, Stylommatophora, Helicidae). 2014 Online ( Memento of the original from March 7, 2014 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.hnords.de
  15. ↑ Fauna Europaea: Cepaea (Austrotachea) sylvatica (Draparnaud, 1801)
  16. ↑ Marco T. Neiber, Bernhard Hausdorf: Molecular phylogeny reveals the polyphyly of the snail genus Cepaea (Gastropoda: Helicidae). Molecular Phylogenetics and Evolution, 93: 143-149, 2015 doi : 10.1016 / j.ympev.2015.07.022
  17. ↑ Marco T. Neiber, Christina Sagorny, Bernhard Hausdorf: Increasing the number of molecular markers resolves the phylogenetic relationship of 'Cepaea' vindobonensis (Pfeiffer 1828) with Caucasotachea Boettger 1909 (Gastropoda: Pulmonata: Helicidae). Journal of Zoological Systematics and Evolutionary Research, 54 (1): 40-45, 2016 doi : 10.1111 / jzs.12116
  18. ↑ MolluscaBase: Macularia sylvatica (Draparnaud, 1801)
  19. ^ Vollrath Wiese: The land snails of Germany. 352 p., Quelle & Meyer, Wiebelsheim 2014 ISBN 978-3-494-01551-4 (p. 308)
  20. ↑ The IUCN Red List of Threatened Species: Cepaea sylvatica