Jump to: navigation, search

Pseudobiceros bedfordi

Pseudobiceros bedfordi
Pseudobiceros bedfordi.jpg
Scientific classification
Kingdom: Animalia
Phylum: Platyhelminthes
Subphylum: Turbellaria
Infraphylum: Rhabditophora
Class: Turbellaria
Order: Polycladida
Suborder: Cotylea
Family: Pseudocerotidae
Genus: Pseudobiceros
Species: P. bedfordi
Binomial name
Pseudobiceros bedfordi

Pseudoceros bedfordi Laidlaw, 1903

Pseudobiceros bedfordi, (common names Persian carpet flatworm[1] and Bedford's flatworm) is a species of flatworm in the family Pseudocerotidae.[2] This species has two penises, which it uses to fence, in an attempt to inject sperm into its opponent in order to fertilize it, while avoiding being fertilized itself.[3]


Pseudobiceros bedfordi is a large polyclad flatworm approximately 8-10 cm in length. It has a distinctive pattern consisting of a brown to black background, with multiple transverse, bilateral pink lines around thousands of tightly spaced, bright yellow spots,[4] pink undulating spots with stripes on the sides of the body.[5] The edges of the body are usually ruffled. The underside of Pseudobiceros bedfordi is pale pink. The front of the body has a pair of erect pseudotentacles.[1]


This worm is fast moving, and is able to swim by undulating its body.[4]


Pseudobiceros bedfordi feeds on ascidians and on crustaceans that are small enough to swallow.[5]


Two specimens of Pseudobiceros bedfordi about to engage in penis fencing

Like all flatworms in the genus Pseudobiceros, they are hermaphroditic and have two penises. During mating, they fence with one another using their penises attempting to stab and inject sperm in their opponent, while avoiding being fertilized themselves. They are able to inseminate their opponent by injecting their sperm into any region of the other's body they are able to penetrate. After successfully injecting the other, the sperm streams through their partner's body on their way to ovaries, where they will fertilize the eggs. The stream is visible through the body tissue of the worm, appearing as pale streaks like lightning jags.[6][7]

Habitat and Ecology


Pseudobiceros bedfordi is found on coral rubble[4] and ledges in back reefs, coastal bays, and in lagoons.[5]


This species is found in Indonesia, Malaysia, Kenya, Micronesia, Northern Mariana Islands, Thailand, Australia, Philippines, Solomon Islands, Myanmar, and Palau.[8]

  • Reported here: Papua New Guinea.

Map showing distribution of observations of Pseudobiceros bedfordi.




Flatworm in Hong Kong Phylum Platyhelminthes - Flatworms Pseudobiceros bedfordi. Recordist: May Tse Terms of use.

More Information


  • GBIF: TaxonID: 4859875
  • Namebank ID: 5023383
  • ZipcodeZoo CritterID: 3150521


  1. 1.0 1.1 Persian carpet flatworms (Pseudobiceros bedfordi) on the Shores of Singapore
  2. WoRMS - World Register of Marine Species -(Pseudobiceros bedfordi)(Laidlaw, 1903)
  3. Arnqvist, Gà¶ran; Rowe, Locke (2005), Sexual conflict, Princeton University Press, ISBN 978-0-691-12218-2, p. 185
  4. 4.0 4.1 4.2 Richmond, Matthew D. (1997), A Field Guide to the Seashores of Eastern Africa and the Western Indian Ocean Islands, IDA/Department for Research Cooperation, SAREC, ISBN 91-630-4594-X, p. 154
  5. 5.0 5.1 5.2 Pseudobiceros bedfordi, Pseudobiceros bedfordi
  6. Hermaphrodites duel for manhood, Science News Online. Accessed 14 March 2009.
  7. [http://www.plosbiology.org/article/info:doi/10.1371/journal.pbio.0020183 PLoS Biology: Everything You Always Wanted to Know about Sexes ]
  8. Pseudobiceros bedfordi (Laidlaw, 1903) - Pseudocerotidae » Nudi Pixel


External Links



Page Notes