Bloody ribbon worm (Lineus sanguineus)

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



Lineus sanguineus is a moderately-sized free-living nemertean worm that can reach up to 20 cm in length and 3 mm in width. Like all ribbon worms, it is an unsegmented, bilaterally symmetrical ciliated worm with a separate mouth and anus. Lineus sanguineus has longitudinal grooves on opposite sides of its head with four to six eyes on each side and a distinct mouth. When irritated it contracts into tight coils. It has varied but uniform colouring.

Recorded distribution in Britain and Ireland

Recorded from the Sound of Jura in Scotland, near Dover, and at Eight Acre Pond on the Solent in England.

Global distribution

Scattered records occur in Britain; France; Nova Scotia, Canada, the Gulf or Maine, the USA; and Punta Arenas, Chile.


Lineus sanguineus is an intertidal species. It is usually found under rocks or embedded in black mud.

Depth range


Identifying features

  • Up to 20 cm in length.
  • Longitudinal grooves on either side of the head.
  • Four to six eyes arranged regularly relatively far back on the head.
  • No caudal cirrus.
  • Lateral nerves embedded in or external to the body wall.

Additional information

Lineus sanguineus can be differentiated from similar species such as Lineus rubens by having its eyes arranged more regularly and further back.

Listed by

- none -


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

  2. 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 Accessed via on 2018-10-01

  2. NBN (National Biodiversity Network) Atlas. Available from:

  3. OBIS (Ocean Biodiversity Information System),  2024. Global map of species distribution using gridded data. Available from: Ocean Biogeographic Information System. Accessed: 2024-07-14


This review can be cited as:

Barnes, M.K.S. 2008. Lineus sanguineus Bloody ribbon worm. 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 14-07-2024]. Available from:

Last Updated: 22/05/2008