A flatworm (Procerodes littoralis)

Distribution data supplied by the Ocean Biodiversity Information System (OBIS). To interrogate UK data visit the NBN Atlas.Map Help



Procerodes littoralis is a small free-living flatworm that reaches up to 7 mm in length. It has a flat and bilaterally symmetrical body. Flatworms are notoriously hard to identify in the field. However, Procerodes littoralis has a pale grey-brown dorsal colouring, and its body is widest at the posterior end. The head has a pointed tentacular lobe on either side. Three diverging stripes are visible in front of its small pair of eyes. Unlike similar species, Procerodes littoralis moves like a leech when disturbed, rather than moving smoothly.

Recorded distribution in Britain and Ireland

Recorded at a few locations off the coasts of Scotland, Anglesey (Wales) and south-west England but may be under recorded.

Global distribution



Often found on the smooth undersides of small boulders in gravel or sandy brackish seabeds.

Depth range


Identifying features

  • Up to 7 mm in length, 1 mm in width.
  • Transverse bands on body are absent.
  • Pointed tentacular lobe on either side of the head.
  • Two well separated eyes.
  • Three diverging stripes on the head.
  • Three major branches to the gut, situated amongst multiple yolk glands.

Additional information

No text entered

Listed by

- none -


  1. Cannon, L.R.G. (ed.), 1995. Biology of Turbellaria & some related Flatworms: Proceedings of the VIIth International Symposium on the Biology of the Turbellaria, Abo/ Turku, Finland. Kluwer Academic Publishers.

  2. Hayward, P.J. & Ryland, J.S. (ed.) 1995b. Handbook of the marine fauna of North-West Europe. Oxford: Oxford University Press.

  3. Howson, C.M. & Picton, B.E., 1997. The species directory of the marine fauna and flora of the British Isles and surrounding seas. Belfast: Ulster Museum. [Ulster Museum publication, no. 276.]


  1. Fenwick, 2018. Aphotomarine. Occurrence dataset http://www.aphotomarine.com/index.html Accessed via NBNAtlas.org on 2018-10-01

  2. NBN (National Biodiversity Network) Atlas. Available from: https://www.nbnatlas.org.

  3. OBIS (Ocean Biodiversity Information System),  2024. Global map of species distribution using gridded data. Available from: Ocean Biogeographic Information System. www.iobis.org. Accessed: 2024-06-20

  4. Suffolk Biodiversity Information Service., 2017. Suffolk Biodiversity Information Service (SBIS) Dataset. Occurrence dataset: https://doi.org/10.15468/ab4vwo accessed via GBIF.org on 2018-10-02.


This review can be cited as:

Barnes, M.K.S. 2008. Procerodes littoralis A flatworm. In Tyler-Walters H. and Hiscock K. Marine Life Information Network: Biology and Sensitivity Key Information Reviews, [on-line]. Plymouth: Marine Biological Association of the United Kingdom. [cited 20-06-2024]. Available from: https://marlin.ac.uk/species/detail/92

Last Updated: 22/05/2008