Dugesia is a dugesiid (Dugesiidae) genus of freshwater flatworms or planarians that includes about 80 formally described species. All Dugesia species present a similar external appearance, they all have a triangle-shaped head given by a pair of auricles, a couple of eyes (although there may be more than two), and an elongated and dorsoventrally flattened body. The colouration of Dugesia species ranges from whitish to almost black. Colouration is not a species-specific trait.
The different species are described and classified on the basis of the morphology of their copulatory apparatus.
Dugesia species inhabit and are quite common in the freshwater bodies (from rivulets to lakes) of Africa (including Madagascar), Eurasia and Australasia.