Greenish pancake snail

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Greenish pancake snail
Systematics
Order : Lung snails (pulmonata)
Subordination : Land snails (Stylommatophora)
Superfamily : Punctoidea
Family : European slugs (Helicodiscidae)
Genre : Lucilla
Type : Greenish pancake snail
Scientific name
Lucilla scintilla
( Lowe , 1852)

The greenish disc snail ( Lucilla scintilla ) is a species of snail in the family of point snails (Punctidae) from the suborder of land snails (Stylommatophora). It was probably anthropogenic to Europe.

features

The small, right-hand wound case is almost disc-shaped; In the side view, the thread extends beyond the penultimate turn, but only slightly. It measures up to 2.2 mm in width and 1.1 mm in height (W / H index = 2). The 3½ to 4 turns increase slowly and regularly and are well arched on the periphery. The seam is comparatively deep. The navel is wide and deep; it takes up a little less than a third of the width of the case. The mouth is rounded and heavily indented due to the previous turn. The mouth opening is at an angle to the winding axis. The edge of the mouth is simple, straight and not reinforced.

The casing is yellowish-brown, the periostracum is yellowish to greenish-yellowish in color. The shell is thin, fragile and translucent. The surface has fine strips of growth at irregular intervals. This makes the surface shiny. At high magnification, faint spiral stripes can be seen in some individuals.

Due to their way of life, the animals have reduced their eyes deep in the ground.

Similar species

The shell of the greenish disc snail is in the adult stage with about 2.2 mm to 3 mm significantly smaller than the shell of the white disc snail ( Lucilla singleyana ). The shell of the greenish disc snail is very flat and conical when viewed from the side, while the shell of the white disc snail is almost flat and disc-shaped. In the side view, the thread of the white disc snail can hardly be seen, while it is also very flat in the greenish disc snail, but it is clearly (more) visible. The umbilicus of the white disc snail is slightly flatter and wider than the umbilicus of the greenish disc snail ( Lucilla scintilla ). In the greenish disc snail the periostracum is yellowish or yellow-greenish, in the white disc snail it is colorless. According to Pilsbry, the white pancake snail is said to have spiral stripes, which, however, should only be visible under high magnification and should be absent from the greenish pancake snail. According to Horsak et al. (2009), however, this characteristic occurs in individuals of both species, but can also be absent in other individuals in both species.

Distribution in Europe (according to Welter-Schultes, 2012)

Geographical distribution and habitat

The original range is not known for sure. The type material comes from Madeira . Otherwise the species occurs in almost all of Europe, mostly rarely and very locally. The species is also widespread in North America. The species has only been reliably proven in the British Isles since 1975. It is missing in fossil deposits, an indication that it was introduced. Schivkov also described the species from the Caucasus.

The animals live deep in loose soil in vineyards, gardens, lawns, in greenhouses and on streets. They are usually only found when large amounts of soil are sifted through. Even then, living specimens are very rare. They are more commonly found in rivers and streams in rivers and streams.

Taxonomy

The taxon was set up in 1852 by Richard Thomas Lowe as Helix (Lucilla) scintilla . It is the type species of the genus Lucilla Lowe, 1852 by monotype. The type locality is Madeira. Presumably the species was introduced to Madeira back then. The species is currently generally accepted. Kerney et al. (1983) had not yet separated the two species, but listed them under Helicodiscus (Hebetodiscus) singleyanus .

Danger

In Central Europe, the species is endangered by intensive land use and the contamination of vineyard soils with copper. According to Vollrath Wiese, an assessment of the existing situation in Germany is not possible due to insufficient data.

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 , p. 121.
  2. ↑ a b Michal Horsák, Jozef Šteffek, Tomáš Čejka, Vojen Ložek, Lucie Juřičkova: Occurrence of Lucilla scintilla (RT Lowe, 1852) and Lucilla singleyana (Pilsbry, 1890) in the Czech and Slovak Republics - with remarks how to distinguish these two non-native minute snails. Malacologica Bohemoslovaca, 8: 24-27, 2009 PDF
  3. ^ 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., Göttingen, Planet Poster Ed., 2012 ISBN 3-933922-75-5 , ISBN 978-3-933922-75-5 (S. 203)
  4. ↑ Evgenij V. Schikov: Lucilla singleyana (Pilsbry, 1890) and L. scintilla (RT Lowe, 1852) (Gastropoda, Pulmonata, Endodontidae) in the Caucasus and in Russia. Folia Malacologica, 25: 165-174, 2017 doi : 10.12657 / folmal.025.013
  5. ↑ AnimalBase: Lucilla scintilla (Lowe, 1852) (accessed June 18, 2018)
  6. ^ Richard Thomas Lowe: Brief diagnostic notices of new Maderan land shells. Annals and Magazine of Natural History (2) 9 (50): 112-120, 275-279, London 1852 Online at Biodiversity Heritage Library p. 115.
  7. ↑ Fauna Europaea: Lucilla scintilla (RT Lowe, 1852) (accessed June 18, 2018)
  8. ↑ MolluscaBase: Lucilla scintilla (RT Lowe, 1852) (accessed June 18, 2018)
  9. ↑ a b Vollrath Wiese: The land snails of Germany. 352 pp., Quelle & Meyer, Wiebelsheim 2014 ISBN 978-3-494-01551-4 , pp. 158/59.
  10. ↑ 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. 136