Nordic diaper snail
| Nordic diaper snail | ||||||||||||
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Nordic diaper snail ( Vertigo ronnebyensis ) |
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| Scientific name | ||||||||||||
| Vertigo ronnebyensis | ||||||||||||
| ( Westerlund , 1871) |
The Nordic diaper snail ( Vertigo ronnebyensis ) is a species of snail of the family of the diaper snail (Vertiginidae) from the suborder of the land snail (Stylommatophora).
features
The right-hand wound, egg-shaped, slightly cylindrical case is 1.91 to 2.28 mm high and 1.13 to 1.33 mm wide. It has 4.5 to 5 slightly arched whorls with a moderately deep seam. The surface is striped regularly, giving it a silky sheen. The thread is only moderately pointed, the last handle is comparatively narrow at the base. The penultimate and last passage therefore have approximately the same diameter. When viewed from the front, the mouth is obliquely pear-shaped.
The edge of the mouth is simple, sharp and hardly thickened (not colored white). Usually there is no bulge in the neck and there is hardly any internal callus. The mouth is reinforced with 2 to 5 weakly developed teeth, usually 3, sometimes 4 or more teeth: a parietal tooth, a columellar tooth, a deep-lying palatal tooth and sometimes a small, higher-lying palatal tooth. The housing is pale brown to yellowish brown in color and translucent. The interruption of growth in winter is almost always marked by a thin white stripe.
Similar species
The shell of the Nordic diaper snail is similar to that of Vertigo modesta . The housing of this type is smaller, more cylindrical and has a thread that is less tapered. The turns are less curved. The last turn is narrower at its base.
Geographical distribution and habitat
The Nordic diaper snail is particularly widespread in Scandinavia. It occurs only very scattered in Central Europe, for example in eastern Germany, in Poland and in north-western Russia as well as along the southern Baltic coast.
The animals live in deciduous and coniferous forests, in Scandinavia typically in coniferous forests, under the deciduous and coniferous litter and under moss, mainly on non-calcareous soils between blueberries ( Vaccinium ). In humid summers they can be found almost anywhere on the forest floor, in dry summers in damp places. But they are less hygrophilous than Vertigo modesta .
Way of life
According to observations made in Poland, the egg-laying period began in June and ended in September at the latest. However, it is very different from person to person. In the most intense period between May and July, the animals laid an egg every other day, or less often every day. The oviposition can also be interrupted for weeks. In total, between one and 55 eggs were laid during a period that usually lasted 40 to 85 days, rarely up to 132 days (mean 23; n = 12). Eggs were seldom laid during two periods. The eggs are 0.58 to 0.78 mm in diameter. They are wrapped in 3 to 6 layers of gelatin. At 18 to 22 ° C, the young hatch after 14 to 22 days. They had a housing with 1.2 to 1.3 turns. The surface of the embryonic shell is covered with fine, irregularly distributed tubercles. About 30% of the young become sexually mature in the year they hatch. The others hibernate as young animals. The interruption of growth in winter is (usually) marked by a white stripe in the housing. Growth will start again in May. A few animals even seem to hibernate twice as juveniles, i.e. before they reach sexual maturity. Most animals die after about a year. Only about 5.5% of individuals live to be two years or older. They can be almost 3 years old.
Taxonomy
The taxon was first described in 1871 by Carl Agardh Westerlund as Pupa ronnebyensis . The type locality is Ronneby in the province of Blekinge in southern Sweden.
Danger
In Germany, the species is “critically endangered” (hazard category 2).
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 (p. 90)
- Stanisław Myzyk: Contribution to the biology of ten vertiginid species. Folia Malacologica, 19 (2): 55-80, Warsaw 2011 doi : 10.2478 / v10125-011-0004-9 .
- Beata M. Pokryszko: The Vertiginidae of Poland (Gastropoda: Pulmonata: Pupilloidea) - a systematic monograph. Annales Zoologici, 43 (8): 133-257, Warsaw 1990.
- 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. 129)
Individual evidence
- ↑ Carl Agardg Westerlund: Expose critique of Mollusques de terre et d'eau douce de la Suède et de la Norvége. Pp. 1–200, Upsala, Berling 1871 Online at Google Books (p. 94).
- ↑ JH Jungbluth, D. von Knorre (with the assistance of U. von Bössneck, K. Groh, E. Hackenberg, H. Kobialka, G. Körnig, H. Menzel-Harloff, H.-J. Niederhöfer, S. Petrick, K Schniebs, V. Wiese, W. Wimmer, ML Zettler): Red list of internal mollusks [snails (Gastropoda) and mussels (Bivalvia)] in Germany. Announcements of the German Malacoological Society, 81: 1-28, Frankfurt / M. 2009 PDF ( Memento of the original from June 16, 2013 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. (1.3 MB)
Web links
- Molluscs of central Europe Vertigo ronnebyensis
- Fauna Europea: Vertigo ronnebyensis
- Vertigo ronnebyensis inthe IUCN Red List of Threatened Species 2013.2. Posted by: Neubert, E., 2011. Retrieved February 13, 2014.