Theodoxus

Theodoxus is a genus of nerites, small water snails with an operculum, some of which live in freshwater, and some in both freshwater and brackish water, aquatic gastropod mollusks in the family Neritidae, the nerites.

== Distribution == The distribution of the genus Theodoxus includes Europe and northern Africa and also extends east to southern Iran. No other species within Neritidae have sympatrical distribution with Theodoxus. The distribution of the genus Theodoxus is an exception within Neritidae, because Neritidae live primarily in the southern hemisphere. Species within Theodoxus are the only Neritidae snails, that live in temperate climate.