Planaria is a genus of planarians in the family Planariidae. It is currently represented by a single species, Planaria torva,[1] which is found in Europe.[2] When an individual is cut into pieces, each piece has the ability to regenerate into a fully formed individual.[3]

Planaria torva.jpg
Planaria torva
Scientific classification edit
Kingdom: Animalia
Phylum: Platyhelminthes
Class: Rhabditophora
Order: Tricladida
Family: Planariidae
Genus: Planaria
OF Müller, 1776
P. torva
Binomial name
Planaria torva
(OF Müller, 1773)
  • Fasciola torva OF Müller, 1773
  • Dendroplanaria torva Komárek, 1926
  • Planaria torfrida Perkins, 1928


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.[4]


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.[5] In the United Kingdom, P. torva is a successful predator of the invasive New Zealand mud snail (P. jenkinsi).[6]


  1. ^ Ball, Ian; Reynoldson, T. B. (1981). "British Planarians. Platyhelminthes: Tricladida. Keys and notes for the identification of the species (Synopses of the British Fauna)". Internationale Revue der Gesamten Hydrobiologie und Hydrographie. Cambridge University Press. 68 (2): 141. doi:10.1002/iroh.19830680211.
  2. ^ Turbellarian Taxonomic Database: Distribution of Planaria torva. Access on 21 April 2016.
  3. ^ "Unravelling How Planaria Regenerate". Sedeer el-Showk. Retrieved 26 January 2017.
  4. ^ Ball, Ian R.; Reynoldson, T. B.; Warwick, T. (2009). "The taxonomy, habitat and distribution of the freshwater triclad Planaria torva (Platyhelminthes: Turbellaria) in Britain". Journal of Zoology. 157 (1): 99–123. doi:10.1111/j.1469-7998.1969.tb01691.x. ISSN 0952-8369.
  5. ^ Reynoldson, T. B.; Sefton, A. D. (1976). "The food of Planaria torva (Müller) (Turbellaria-Tricladida), a laboratory and field study". Freshwater Biology. 6 (4): 383–393. doi:10.1111/j.1365-2427.1976.tb01623.x. ISSN 0046-5070.
  6. ^ Reynoldson, T. B.; Piearce, Bronwen (1979). "Predation on snails by three species of triclad and its bearing on the distribution of Planaria torva in Britain". Journal of Zoology. 189 (4): 459–484. doi:10.1111/j.1469-7998.1979.tb03974.x. ISSN 0952-8369.