Forked doll snail

Forked doll snail
Nabeled pupa snail ( Lauria cylindracea )
Systematics
Order : Lung snails (pulmonata) Subordination : Land snails (Stylommatophora) Superfamily : Pupilloidea Family : Lauriidae Genre : Lauria Type : Forked doll snail
Scientific name
Lauria cylindracea
( Mendes da Costa , 1778)

The Lauria cylindracea ( Lauria cylindracea ) is a breathing land snail from the family of lauriidae . She is viviparous ( ovoviviparous ) and gives birth to very few fully developed young each year. Along with Helix aspersa, it is the most common type of snail in many regions in southern Europe .

features

The case is 3 to 4 mm high and about 1.8 mm wide (thick). It is ovate to approximately cylindrical with a blunt apex, and has five to seven slightly arched convolutions in the adult stage. However, the outer shape can vary from cylindrical to truncated conical. The end turn develops an edge at the lower edge. The mouth is round, elliptical to slightly oval with a white, sharp-edged, outwardly turned edge, which is thickened with callous lips and a parietal callus. However, the degree of turnover can vary. The usually formed angular tooth is connected to the tip of the outer lip; it continues inside the case as a fine, spiral line and can be seen through the shell from the outside. But it can rarely be absent. In juvenile animals there is a columellar lamella and some palatal folds that appear as spiral lines through the housing. They are reabsorbed in the adult stage. The navel is narrow and open.

The skin is brown and translucent, the surface is shiny and has only faint growth lines. The soft body of the animal is dark, with the foot and sides usually a little lighter. The upper antennae are relatively short, the lower antennae very short. The case is carried very high in a vertical position above the body when crawling.

In the genital apparatus, the male and female tracts divide very early, and there is virtually no egg ladder. The thin sperm duct (vas deferens) is therefore very long; it opens apically into the comparatively very short epiphallus . This swells very quickly after the confluence of the spermatic duct; the diameter then decreases by half at the epiphallus / penis transition. A comparatively long, conical blind sack ("caecum" or penile blind sack, also appendix) sits at the transition between epiphallus and penis. The penis is comparatively very long and about three times the length of the epiphallus. The very long penile appendix starts around the beginning of the lower third of the penis. The lower part of the penis appendix is ​​thick (about the thickness of the penis), after which the thickness initially decreases by half. The following part is very long and thin, the end part is again very strong, swollen club-shaped. The retractor muscle divides into two strands, one of which starts at the end of the strongly thickened lower part of the penile appendix, the other strand at the epiphallus / penis transition between the epiphallus and the penile blind sac.

The upper fallopian tube is transformed into the "uterus" in which the eggs are held back until the young are fully developed. Due to the early separation of the spermatic and fallopian tubes, the free fallopian tube is very long overall. The spermathec branches off from the fallopian tube just before the atrium. As a result, the vagina is virtually missing. The stem of the sperm library is very long. The seminal vesicle is comparatively small and lies in the area of ​​the prostate and the protein gland.

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

Geographical distribution and habitat

The bifurcated doll snail is found in Madeira , the Canary Islands and the Azores as well as in the Atlantic influenced regions of Western Europe ( British Isles , France, Belgium, Netherlands, Germany, Denmark), in the coastal areas of Scandinavia (up to 64 ° N; isolated on the Lofoten Islands ), Orkney Islands, Southern Europe (Italy, coastal areas of the Balkan Peninsula and Greece), Asia Minor, Cyprus, isolated on the Crimean peninsula and in the Caucasus , in the Kopet-Dag ( Turkmenistan ), in the Middle East ( Lebanon , Israel ) and in the Arabian Peninsula . There are also some isolated occurrences in western Switzerland, in Mecklenburg-Western Pomerania, in Lower Saxony, in Hesse and on the Isteiner Klotz (Baden-Württemberg). In the meantime the species has also been anthropogenic to New Zealand . There are also reports of finds from South Africa , as well as from North America ( British Columbia and Jamaica ) and Tristan da Cunha in the South Atlantic.

The animals live in forests, on rocks, in meadows in not too humid places, often under ivy on stone walls. However, the need for moisture also seems to be slightly different from region to region. On the Crimean Peninsula, for example, the species is about ten times more common in dry habitats than in moist habitats. In Portugal, on the other hand, they tend to live in damp and shady habitats under mosses, under stones, leaf litter and the bark of rotten trees. In Switzerland it rises up to 800 m above sea level.

Way of life

The bifurcated pupa snail is exclusively viviparous (ovoviviparous). The life cycle has been studied in detail on a population in Israel (Heller et al., 1997). Most land snail species in Israel are inactive during the dry and hot summer months and only wake up again with the onset of autumn and winter rains. The bifurcated doll snail is an exception, because it is also active in summer, as they live in habitats that are still a bit damp in summer. By contrast, they become inactive in the coolest and wettest winter months. The reproductive period usually begins in December, when the animals become very active after the first winter rains. By the middle of summer, all individuals carry three to five fully developed embryos with them, the juvenile snails are successively “born” over the course of the summer. In an individual with embryos, the embryos can be up to 25% of the weight. Very few specimens with embryos were found in late summer and early autumn. Presumably only about five to six juvenile snails are “born” per individual and season. At “birth” the young animals already have a housing with 1.5 to 2.5 coils and a diameter of around one millimeter. The animals take two years to reach sexual maturity and live up to five years.

Taxonomy

The taxon was first described by Emanuel Mendes da Costa in 1801 as Turbo cylindraceus . The species is de facto the type species of the genus Lauria Gray, 1840, since the formal type species, Pupa umbilicata Draparnaud, 1801 is a younger subjective synonym of Lauria cylindracea .

In molecular genetic studies it was found that there is a northern and a southern population within the taxon, which differ on the basis of a mini-satellite motif (TGGAAGTG). This mini-satellite motif occurs twice in a row in the southern population, and even three times in a row in the northern population. The border between the two populations runs through Germany. The populations in Mecklenburg-Western Pomerania belong to the northern population, while specimens from Rhineland Palatinate already belong to the southern population.

Hazard and protection

The species is very common in southern Europe, the second most common in Portugal, it is also very common in Great Britain, but populations have declined. In Switzerland, the species occurs or only occurred in a few, very warm locations that have already disappeared due to habitat destruction. It is also a rare species in Germany. It is classified as endangered in Germany.

literature

• 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
• J. Heller, N. Sivan and AN Hodgon: Reproductive biology and population dynamics of an ovoviviparous land snail, Lauria cylindracea (Pupillidae). Journal of Zoology London, 243: 263-280, 1997 doi : 10.1111 / j.1469-7998.1997.tb02781.x
• Francisco W. Welter-Schultes: European non-marine molluscs, a guide for species identification = identification book for European land and freshwater mollusks. A1-A3 p., 679 p., Q1-Q78 p., Planet Poster Ed., Göttingen 2012, ISBN 3-933922-75-5 , ISBN 978-3-933922-75-5 (p. 132)

Individual evidence

1. ↑ ^{a b} Animal Base - Lauria cylindracea
2. ^ 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 (p. 202)
3. ^ Anna Ritchie: Excavation of a Neolithic farmstead at Knap of Howar, Papa Westray, Orkney. Proc Soc Antiq Scot, 113: 40-121, 1983 PDF
4. ^ Yaroslav Starobogatov: Fauna and Zoogeography of Molluscs of Turkmenistan. Biogeography and Ecology of Turkmenistan, Monographiae Biologicae, 72: 535-543, 1994 preview
5. ↑ Holger Menzel-Harlof: The mollusc fauna of the NSG Campower Steilufer (district of Northwest Mecklenburg ) with special consideration of the occurrence of Lauria cylindracea (DA COSTA, 1778). Announcements of the NGM, 4 (1): 44-52, 2004 PDF
6. ^ Walter Wimmer, Karl-Heinz Eichler: Lauria cylindracea (Da Costa, 1778) (Gastropoda: Lauriidae) in the Braunschweig Botanical Garden - first record for Lower Saxony. Braunschweiger Naturkundliche Schriften, 7 (2): 339-343, 2005 ISSN  0174-3384 PDF ( Memento of the original from September 3, 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. 
7. ↑ Carsten Renker: A record of the nabeled pupa snail, Lauria cylindracea (Da Costa, 1778), for Hessen (Gastropoda: Stylommatophora: Lauriidae). Communications of the German Malacoological Society, 82: 49-50, Frankfurt a. M., 2009 PDF ( Memento of the original dated September 3, 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. 
8. ↑ Verena Rösch and Felix Weiß: A record of the Nabeled pupa snail Lauria cylindracea (DA COSTA 1778) at the Isteiner Klotz: first record of life in Baden-Württemberg (Gastropoda: Stylommatophora: Lauriidae). Mitt. German malakozool. Ges. 81: 29-30, Frankfurt a. M., May 2009
9. ^ Museum of New Zealand or RC Willan: The chrysalis snail (Lauria cylindracea) in New Zealand. Poirieria, 9: 27-9, 1977.
10. ^ HE Quick: Emigrant British Snails. Proceedings of the Malacological Society, 29: 181-189, London 1952
11. ^ David G. Herbert: The introduced terrestrial Mollusca of South Africa. SANBI Biodiversity Series, 15, 108 S., Pretoria 2010 PDF
12. ^ Robert G. Forsyth: Land Snails of British Columbia. Royal British Columbia Museum Handbook. IV + 188 pp., Royal BC Museum, Victoria, 2004
13. ^ Gary Rosenberg, Igor V. Muratov: Status Report on the Terrestrial Mollusca of Jamaica. Proceedings of the Academy of Natural Sciences of Philadelphia, 155 (1): 117-161, Philadelphia, Pennsylvania 2006 doi : 10.1635 / i0097-3157-155-1-117.1
14. ^ RC Preece: Introduced land molluscs on the islands of the Tristan da Cunha - Gough group (South Atlantic). Journal of Conchology, 37: 253-259, 2001. Abstract
15. ↑ Emanuel Mendes da Costa: Historia naturalis testaceorum Britanniæ, or, the British conchology; containing the descriptions and other particulars of natural history of the shells of Great Britain and Ireland: illustrated with figures. In English and French. London, Millan, White, Emsley & Robson 1778. Online at www.biodiversitylibrary.org (p. 89)
16. ^ Carsten Renker: Genetic break in Lauria cylindracea (Da Costa 1778) (Gastropoda: Stylommatophora: Lauriidae). Archives for Molluscology: International Journal of Malacology, 136, (1): 1-7 Abstract
17. ^ Vollrath Wiese: The land snails of Germany. 352 pp., Quelle & Meyer, Wiebelsheim 2014 ISBN 978-3-494-01551-4 (p. 111)