Lymnaea stagnalis, better known as the great pond snail, is a species of large air-breathing freshwater snail, an aquatic pulmonate gastropod mollusk in the family Lymnaeidae. The great pond snail is a model organism to study parasitology, neurology, embryonal development and genetic regulation. Limnaea stagnalis var. baltica Lindström, 1868: synonym of Lymnaea stagnalis (Linnaeus, 1758)