Great Pond Snail

The distribution of this species is holarctic, mainly the temperate zones of Northern America, Europe and Asia. The snail can be found in many ponds, lakes and very slow-moving rivers with a rich underwater vegetation. The northernmost populations exist in northern Norway, and in Central Europe, it inhabits even montane ecosystems at 1700 meters above sea level. In the Saprobic system used in Germany to judge the quality of freshwater biotopes, the species has a value of 1.9 and indicates a biotope with a water quality class II, the second-highest.

Lymnaea stagnalis is a simultaneously hermaphroditic species and can mate in the male and female role, but within one copulation only one sexual role is performed at a time. Lymnaea stagnalis perform more inseminations in larger groups and prefer to inseminate novel over familiar partners. Such higher motivation to copulate when a new partner is encountered is known as the Coolidge effect and has been demonstrated in hermaphrodites firstly in 2007.