Planaria

Planaria is a genus of planarians in the family Planariidae. It is currently represented by a single species, Planaria torva, which is found in Europe. When an individual is cut into pieces, each piece has the ability to regenerate into a fully formed individual. Currently the genus Planaria is defined as freshwater triclads with oviducts that unite to form a common oviduct without embracing the bursa copulatrix and with an adenodactyl present in the male atrium. The testes occur along the whole body. The food of P. torva consists of freshwater gastropods, tubificid worms, and freshwater arthropods, such as isopods of the genus Asellus and chironomid larvae, although it shows a clear preference for snails. In the United Kingdom, P. torva is a successful predator of the invasive New Zealand mud snail (P. jenkinsi).