Freshwater snails are aquatic gastropod molluscs common in the freshwater ecosystems they inhabit, large and small masses of running or stagnant water, such as ponds, lakes, lagoons and rivers around the world. They are not closely related to each other, some groups come from terrestrial snails while others come from marine snails.
There are more than four thousand species of freshwater snails, with different methods of reproduction and life from one that goes from a few weeks to a few years. Freshwater snails are adapted to various ecological niches, some are completely aquatic, others have an amphibian life form and others alternate periods of dryness alternating with periods of heavy rainfall. These adaptations are reflected in the diversity of their lifestyle: branchial breathing species characteristic of torrents and rivers with strong current and oxygenated waters, totally aquatic species in stagnant waters without oxygen, amphibian species and moderately amphibious species and equipped with an opercular cover that closes the entrance of the shell, to prevent the drying of the animal, while it remains buried in the mud, in the dry season.
They are able to reproduce at a very rapid rate, and some species are considered pests and invasives.