Globular glass snail

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Globular glass snail
Globular glass snail (Vitrina pellucida)

Globular glass snail ( Vitrina pellucida )

Systematics
Subordination : Land snails (Stylommatophora)
Superfamily : Limacoidea
Family : Glass snails (Vitrinidae)
Subfamily : Vitrininae
Genre : Showcase
Type : Globular glass snail
Scientific name
Vitrina pellucida
( OV Müller , 1774)

The spherical glass snail ( Vitrina pellucida ) is a type of snail from the family of glass snails (Vitrinidae), which belongs to the suborder Stylommatophora of the terrestrial lung snails (Pulmonata).

features

The right-hand winding, small housing is low-conical. In the side view, the thread is clearly raised. The animal can still withdraw completely into the housing in the adult stage. The case measures 4.5 to 6 mm in diameter and up to 3 mm in height. It has 2.75 to 3.5 turns that increase rapidly. The last turn takes up less than 50% of the case diameter. The top of the turns is flat, the seam is moderately deep. The periphery is well arched and the apex is hemispherical. This results in an overall spherical habit (name!). The housing is not marked. The mouth opening is moderately wide and is very sloping. When viewed from above, the mouth is flattened, elliptical, apart from the slight incision due to the previous turn. The mouth edge is straight and sharp. The mouth has no or only a very small skin seam.

The skin is thin, fragile and translucent, usually with a greenish tinge. The surface of the Teleoconch is smooth and shiny, apart from very fine, irregular, often wrinkled strips of growth. The Protoconch has very small pits that are arranged in a spiral. The soft body is usually gray to dark gray, the head and antennae are usually a little darker. When stretched, the animal can measure about 10 mm. The coat is relatively narrow with a small, gray or dark gray coat flap. This does not cover the apex of the housing. Due to the (dark) gray soft body, the housing also appears very dark in living animals.

In the hermaphroditic genitalia, the spermatic duct (vas deferens) is very short. The slightly club-shaped penis is short, slender and curved. It is surrounded by a tissue covering almost its entire length. The spermatic duct dips under this sheath at the lower end of the penis, but only penetrates apically into the penis. In addition, the penile retractor muscle also starts. Internally, the penis has a large, pilaster- like structure. In the female part, the free fallopian tube (oviduct) is short and wide, a vagina is virtually non-existent. The penis, sperm and free fallopian tubes flow into the long atrium at almost the same level. According to Guisti et al. (2011) the spermatheque flows into the atrium a little above the penis . This short section between the confluence of the spermathec and the penis is surrounded by glandular tissue that also extends to the base of the spermathec, and is described by Giust et al. (2011) interpreted as a short vagina. The spermathec has a short stalk that is strongly thickened at the base. The bladder is comparatively large and egg-shaped. It attaches itself to the lower part of the egg ladder (spermoviduct).

Similar species

The species differs from most other species of glass snails by the spherical habit of the shell. Only the large glass snail ( Phenacolimax major ) still has a certain similarity. However, the case is more pressed and the last turn is a little wider (in relation to the case diameter). The mouth is also more flattened, transversely elliptical.

Distribution of the species in Europe and western Turkey (according to Welter-Schultes, 2012)

Geographical distribution and habitat

The distribution area includes all of Europe, Asia Minor and Central Asia. In the north of Scandinavia, it even penetrates the Arctic Circle. It is also found in Iceland. In Switzerland mountains the species rises to 3,100 m above sea level, in Bulgaria up to 1,800 m. In general, the species is most common in Switzerland at altitudes between 1,000 and 2,000 m above sea level.

The animals live in moist to dry locations of coniferous and deciduous forests, meadows, between stones, on walls, scree slopes, also in the vegetation of streams and in depressions of grassy dunes. It also tolerates acidic soils.

Way of life

In the lowlands the species has an annual cycle. The eggs are laid in autumn and the animals die soon after. The young hatch in spring, they become sexually mature by autumn. The eggs are 0.9 to 1.2 mm in diameter. In Ireland the adults overwinter and lay eggs in spring. The young hatch in early summer. In eastern Germany and Poland, the adults lay eggs in October. The young hatch in February and March. Most of the animals die after they have laid their eggs, a few survive the winter and die in the spring. In Switzerland, eggs are laid between September and November. The animals die each time they lay their eggs. In the south of France, eggs are laid between July and October. About 6 to 8 dirty white colored eggs are laid per clutch. The outer shell is opaque, the size of the proverbial egg-shaped eggs is 0.9 to 1.0 mm × 1.1 to 1.2 mm. At first the young live almost exclusively underground and only come to the surface in autumn. In Switzerland, Lothar Forcart observed sexually mature animals in summer as well as young animals. He interprets this to mean that the species has a cycle of several years in the high mountains. During copulation, each other's penis is inserted into the atrium and the sperm is transferred.

The animals are very insensitive to the cold and can even be observed in mild winters with little snow until January or even February. They feed on withered leaves and dead plant parts. However, carrion is also accepted.

Taxonomy

The taxon was set up in 1774 by Otto Friedrich Müller as Helix pellucida . It is the type species of the genus Vitrina Draparnaud, 1801 and generally accepted.

The Fauna Europaea has 16 synonyms .

Danger

The species is widespread and common in Germany. It is not endangered in existence.

literature

  • Klaus Bogon: Land snails biology, ecology, biotope protection. 404 p., Natur Verlag, Augsburg 1990, ISBN 3-89440-002-1 , p. 180/81.
  • Rosina Fechter and Gerhard Falkner: molluscs. 287 pp., Munich, Mosaik-Verlag 1990 (Steinbach's Nature Guide 10) ISBN 3-570-03414-3 , p. 172
  • Michael P. Kerney, RAD Cameron & Jürgen H. Jungbluth: The land snails of Northern and Central Europe. 384 pp., Paul Parey, Hamburg, pp. 149/50.

Individual evidence

  1. ↑ a b c Lothar Forcart: Monograph of the Swiss Vitrinidae (Moll. Pulm.). Revue Suisse des Zoologie, 51: 629-678, 1944 Online at Biodiversity Heritage Library , pp. 639-641.
  2. ↑ Folco Giusti, Viviana Fiorentino, Andrea Benocci, Giuseppe Manganelli: A Survey of Vitrinid Land Snails (Gastropoda: Pulmonata: Limacoidea). Malacologia, 53 (2): 279-363, 2011 Academia.edu
  3. ^ Alexandru V. Grossu: Gastropoda Romaniae 4 Ordo Stylommatophora Suprafam: Arionacea, Zonitacea, Ariophantacea şi Helicacea. 564 S., Bucharest 1983, pp. 65-67.
  4. ↑ Anatolij A. Schileyko: Treatise on Recent Terrestrial Pulmonate Molluscs Part 11 Trigonochlamydidae, Papillodermidae, Vitrinidae, Limacidae, Bielziidae, Agriolimacidae, Boettgerillidae, Camaenidae. Ruthenica, Supplement 2 (11): 1467-1626, Moscow 2003 ISSN  0136-0027 , p. 1488.
  5. ^ A b 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., Planet Poster Ed., Göttingen 2012, ISBN 3-933922-75-5 , ISBN 978-3-933922-75-5 (p. 429)
  6. ↑ Lothar Forcart: The Nordic species of the genus Vitrina. Archives for Molluscology, 84: 155-166, 1955
  7. ^ Ewald Frömming: Biology of the Central European Landgastropods. 404 S., Duncker & Humblot, Berlin, 1954, pp. 113-115.
  8. ↑ Tomasz Umiński, Urszula Focht: Population dynamics of some land gastropods in a forest habitat in Poland. Malacologia, 18: 181-184, 1979 Online at www.biodiversitylibrary.org .
  9. ↑ Otto Friedrich Müller: Vermium terrestrium et fluviatilium, seu animalium infusoriorum, helminthicorum, et testaceorum, non marinorum, succincta historia. Volume alterum. SI-XXXVI, 1-214, Heineck & Faber, Copenhagen & Leipzig, 1774 Online at www.biodiversitylibrary.org (p. 15)
  10. ↑ AnimalBase: Vitrina pellucida (OV Müller, 1774)
  11. ↑ a b Fauna Europaea: Vitrina pellucida (OF Muller, 1774)
  12. ↑ MolluscaBase: Vitrina pellucida (OV Müller, 1774)
  13. ↑ a b Vollrath Wiese: The land snails of Germany. 352 pp., Quelle & Meyer, Wiebelsheim 2014, ISBN 978-3-494-01551-4 (p. 228).

annotation

  1. ↑ Giusti et al. (2011) take the opposite view, however, that the soft body can no longer be fully withdrawn into the housing.