Pointed pond snail
| Pointed pond snail | ||||||||||||
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Pointed pond snail ( Viviparus contectus ), |
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| Scientific name | ||||||||||||
| Viviparus contectus | ||||||||||||
| Millet , 1813 |
The tip pond snail ( Viviparus contectus ) is a freshwater snail from the family of the pond snail (order Architaenioglossa ).
features
The case measures up to 45 mm in height and up to 35 mm in width. It has 6 to 6.5 turns and is greenish-brown to black. The turns are stepped and the navel is open. The apex is pointed. There are usually three red bands on the coils. Under different living conditions, it develops various shape variants ( V. c. F. Virescens , V. c. F. Nigerrimus and V. c. F. Menzeli ).
Reproduction
Like all members of the Viviparidae family, the animals are viviparous ( ovoviviparous ). In the uterus of the female, the young gradually mature from 12–30 egg capsules during the summer, which then usually leave the mantle cavity of the mother in a size of 2.5 to 10 mm.
Way of life and distribution
V. contectus are found mainly in stagnant waters, often in murky, weedy and veralgten muddy ponds and brooks (see. The German surname sump cover screw). It is also found in acidic bog pools and swamps. This distinguishes V. contectus from most other Viviparidae. It is a grazer, filter feeder, or feeds on detritus. The animals overwinter buried in the mud and can live up to 13 years.
The species occurs in almost all of Europe. It is absent in Norway, Finland and southern Europe.
Similar species
One can best distinguish the two types by the separation of the individual passages of the housing: Viviparus viviparus has slimmer, non-stepped housing coils; in the case of V. contectus , the more bulbous whorls are distinctly stepped. This makes it a more pointed impression. In V. viviparus the umbilicus is significantly narrower, almost closed.
Danger
The pointed mud snail is listed on the Red Lists of Germany and Austria as endangered, in Switzerland as critically endangered. It has been added to the Czech Republic 's early warning list . Mechanical weed removal measures, other hydraulic engineering measures and drainage of water bodies are considered to be the causes of danger .
literature
- Peter Glöer: The animal world of Germany. Mollusca I Freshwater gastropods of Northern and Central Europe Key to identification, way of life, distribution. 2. rework. Ed., 327 pages, ConchBooks, Hackenheim 2002 ISBN 3-925919-60-0
Web links
- European Viviparidae - Viviparus contectus
- MollBase
- www.wirbellose.de
- Viviparus contectus in the Red List of Threatened Species of the IUCN 2013.2. Posted by: Van Damme, D., Kebapçı, U. & Seddon, M., 2012. Retrieved February 12, 2014.
