Left-handed diaper snail
| Left-handed diaper snail | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
Left-handed diaper snail ( Vertigo pusilla ) |
||||||||||||
| Systematics | ||||||||||||
|
||||||||||||
| Scientific name | ||||||||||||
| Vertigo pusilla | ||||||||||||
| ( OV Müller , 1774) |
The left-wound diaper snail ( Vertigo pusilla ) is a species of snail from the family of the diaper snail (Vertiginidae) in the suborder of the land snail (Stylommatophora). The German trivial name is somewhat misleading in that there is a second vertigo type, the narrow diaper snail ( Vertigo angustior ) , which has a left-handed housing.
features
The yellowish-brown shell of the left-hand nappy snail is, as the German common name suggests, left-hand wound and of a bulbous, egg-shaped shape. It has 4.2 to 5.25 well arched, translucent turns, is 1.66 to 2.18 mm high and 1.01 to 1.20 mm wide ( Myzyk ). The turns are separated from each other by a deep seam. The shiny surface shows fine, irregular growth stripes. Six teeth usually extend into the mouth, two parietal teeth, two columellar teeth and two palatal teeth. Rarely there can be up to nine teeth, two smaller teeth parietal and angular, and very rarely (around 1.2% of cases) an infraparietal tooth on the parietal wall. The edge of the mouth is slightly thickened with lips, only slightly broadened and curved outwards.
Similar species
Within the genus Vertigo , only the narrow diaper snail ( Vertigo angustior ) has a left-handed casing. This species is slightly smaller and the outer wall of the last turn has a notch that corresponds to a long, lamellar upper palatal tooth on the inside.
Geographical distribution and habitat
The distribution area of the species extends from Ireland and the Iberian Peninsula in the west to Bulgaria, Asia Minor, the Caucasus region, Ukraine and Russia to the Altai. In Scandinavia the area reaches up to 68 ° N. The species is only very scattered and local in this huge area. In Poland it rises up to 1500 m above sea level, in Switzerland up to 1900 m and in Bulgaria up to 1600 m.
It prefers somewhat drier habitats such as dry, stony soils, stone walls, rocks, light deciduous and mixed forests and bushes, hedges, and is exceptionally also found in sand dunes. It lives there in the litter and in tree crevices and holes, which store some moisture.
Way of life
According to observations made in Poland, the animals begin to lay eggs in May. The eggs are laid in a moist substrate, which the hatchlings serve as food as soon as they hatch. At the beginning of the egg-laying period, an egg was laid almost every day, later in the season the intervals increased. The oviposition period lasted between half a month and about 50 days, rarely more than 130 days. Some individuals laid their last eggs in May, others only in early September. The number of eggs that are produced during an egg-laying period varies widely from 4 to 74 (mean: 29 eggs). Many animals died at the end of the egg-laying period, others overwintered and laid further eggs during a second season. So two specimens came to a total of 102 and 89 eggs in the two egg-laying periods. The diameter of the eggs ranges from 0.52 to 0.70 mm. Most eggs were laid in the single-cell stage, few eggs were further developed. The speed of development is strongly temperature dependent. At 27 ° C, the young hatch after 11 days, at 24 ° C after 12 days, and at 10 ° C after 18 to 19 days. At the time of hatching, the young had a housing with 1.25 to 1.3 coils and a width of 0.52 to 0.6 mm. Further development is rather slow. Only about 16% of the young became sexually mature in the same year, usually only at the end of the egg-laying season (2nd half of August to October). In October, the animals went into hibernation, which is documented in the housing by a single bright growth strip. Activity and growth resumed in some animals in the first half of April, in others not until the end of May. Most of them became sexually mature now, a few probably hibernated a second time before they became sexually mature. The animals live to be two to three years old. In mid-September, a population comprised 15% of individuals hatched that year, with only 4% adult and the rest still juvenile. 71% had hatched the year before, 12% two and 2% three years ago.
In Switzerland the picture was somewhat different. There the young hatched after 7 to 12 days. Under favorable conditions, they reached sexual maturity after 30 to 40 days. In Switzerland, three to four generations per year are therefore possible. The animals only live about 1.5 years.
Taxonomy
The taxon was first described by Otto Friedrich Müller in 1774 . It is the type species of the genus Vertigo OF Müller, 1773. Some authors subdivide the genus Vertigo into two sub-genera: Vertigo (Vertigo) OF Müller, 1773 and Vertigo (Vertilla) Moquin-Tandon, 1856. In this sub-genre, the left-hand nappy snail is divided into the Genus Vertigo (Vertigo) posed.
supporting documents
literature
- Klaus Bogon: Land snails biology, ecology, biotope protection. 404 p., Natur Verlag, Augsburg 1990 ISBN 3-89440-002-1 (p. 108)
- Rosina Fechter and Gerhard Falkner: molluscs. 287 p., Mosaik-Verlag, Munich 1990 (Steinbach's Nature Guide 10) ISBN 3-570-03414-3 (p. 140)
- 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): pp. 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): pp. 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
Individual evidence
- ↑ Otto Friedrich Müller: Vermivm terrestrium et fluviatilium, seu animalium infusoriorum, helminthicorum, et testaceorum, non marinorum, succincta historia. Volume alterum. SI-XXXVI, pp. 1-214, Havniæ / Copenhagen & Lipsiæ / Leipzig, Heineck & Faber, 1774 Online at www.biodiversitylibrary.com (p. 124).
- ^ Molluscs of central Europe Vertigo pusilla
