The freshwater or river limpit is a small native species only growing to a maximum of 1cm, though 0.3 is more usual. Despite its common name, it is not related to marine limpits and is instead closer to the ramshorn snails (planorbis sp). They are great algae grazers and will graze algae from rocks, glass and plants (they won't eat live plants). Being a native species, it can survive UK winters but can also be kept in coldwater and tropical aquariums. This species prefers running water and will stay near the outflow of the filter.