Planorbis planorbis

Planorbis planorbis is a species of air-breathing freshwater snail, an aquatic gastropod mollusk in the family Planorbidae, the ram's horn snails.

Distribution

 * Cosmopolitan - introduced and being considered invasive to many places and considered as a pest
 * Czech Republic - least concern (LC)
 * Slovakia
 * Germany - not listed in red list
 * the Netherlands
 * Poland
 * Great Britain
 * Ireland
 * Hungary

Description
This species, like all planorbids, has a sinistral shell. The width of the shell is 15 – 20 mm. The keel on the periphery of the shell is near the edge closest to the spire side, which is carried downwards in life.

Ecology
The habitat of this species is shallow standing and slowly running freshwaters on a mud substrate, also ponds and temporarily drying flood waters, up to 1 metre depth. Planorbis planorbis does not tolerate intensive water movements but is tolerant to eutrophic conditions.