Great Pond Snail

Great pond snail, Lymnaea stagnalis, is a large air-breathing freshwater snail, an aquatic pulmonate gastropod mollusk of the family Lymnaeidae, widespread across ponds, lakes and slow-moving fresh water of the Northern Hemisphere. It surfaces periodically to breathe air through a simple lung rather than gills, and because of its large, easily studied nerve cells the species has become a widely used model organism in research on parasitology, neurology, embryonic development and genetic regulation.