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Planaria torva.jpg
Planaria torva
Scientific classification e
Kingdom: Animalia
Phylum: Platyhelminthes
Order: Tricladida
Family: Planariidae
Genus: Planaria
OF Müller, 1776

Planaria is a genus of planarians in the family Planariidae. When an individual is cut into pieces, each piece has the ability to regenerate into a fully formed individual.[1]


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.[2]

Planaria originally have habitats in dark, murky water which results in such sensitivity (Paskin et al., 2014). They are also sensitive to other stimuli such as chemical gradients, vibration, magnetic and electric fields (Deochand et al., 2018). Their central nervous system includes the anterior (head, brain and eyes) and middle (abdominal trunk and pharynx) (Deochand et al., 2018).


The food of Planaria species includes of freshwater gastropods, tubificid worms, and freshwater arthropods, such as isopods of the genus Asellus and chironomid larvae.[3] In the United Kingdom, P. torva is a successful predator of the invasive New Zealand mud snail (Potamopyrgus jenkinsi).[4]


The following species are recognised in the genus Planaria:


  1. ^ "Unravelling How Planaria Regenerate". Sedeer el-Showk. Retrieved 26 January 2017.
  2. ^ 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.
  3. ^ 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.
  4. ^ 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.