Sharp pan snail

Sharp pan snail
	Sharp pan snail
Systematics
Class :	Snails (gastropoda)
Order :	Lung snails (pulmonata)
Subordination :	Water lung snails (Basommatophora)
Family :	Plate snails (Planorbidae)
Genre :	Anisus
Type :	Sharp pan snail
Scientific name
	Anisus vortex
	( Linnaeus , 1758)

The sharp pancake snail , also known as a spiral-shaped poppet snail ( Anisus vortex ), is a water lung snail (Basommatophora) from the family of poppy snails (Planorbidae).

features

The case is only 0.8 to 1.1 mm high and measures up to 9 mm in diameter. It has up to 7 whorls. The top is almost flat, the bottom is a little sunk. On the upper side, the whorls are flat and only separated from one another by a slight seam. On the other hand, the whorls on the underside are more curved and separated from one another by a clear seam. A high keel is formed on the last passage. The animals have an extremely short, rounded foot and quite long, thin antennae.

Reproduction

In spring several spawning capsules with 2 to 12, possibly also up to 20 eggs are deposited. The development is strongly dependent on temperature and takes about 11 days at 18 °. Then the finished young hatch.

Occurrence, way of life and distribution

The sharp cuspidor snail lives on plants in slowly flowing or stagnant waters. It feeds on rotting leaves of aquatic plants and algae. She rasps off pieces of the surface. It occurs from Western Europe to Siberia. But it is almost completely absent in Scandinavia; there are only small deposits in southern Sweden. It belongs to the water snails that "breathe water" in oxygen-rich waters (the lungs are filled with water), therefore do not come to the surface and are therefore often not discovered for a long time (see Planorbis ).

Similar species

The petite cochlea ( Anisus vorticulus ) is somewhat smaller and has a blunt keel.

Systematics

The sharp pan snail is also placed together with the petite pan snail in the subgenus Anisus (Disculifer) CR Boettger, 1944.

Danger

The species is classified as endangered in Austria and Switzerland.

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 D., ConchBooks, Hackenheim 2002 ISBN 3-925919-60-0
Ewald Frömming: Biology of the Central European freshwater snails. 313 pp., Duncker & Humblot, Berlin 1956.