A bristleworm (Ophelia borealis)

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



Ophelia borealis has a stout, segmented body that increases rapidly in width from the head to the 10th segment and grows to up to 2.3 cm in length. The body is divided into a head, thorax of 10 segments, abdomen of 20 segments and a pygidium. It is deep red in colour with an iridescent blue or lilac overtone. The head bears a pointed cone-shaped prostomium and a short, blunt proboscis. The head is differentiated from the thorax by 15 superficial rings. Segments are marked by 5-7 superficial rings, and a pair of parapodia on either side bearing cylindrical, slender chaetae that are longer dorsally. The abdomen bears slender chaetae-like gills and is distinguished by a deep ventral groove that runs from the 7th segment towards the pygidium and two lateral grooves that house vertical rows of small pores above the notopodia. Numerous papillae cover the surface of the pygidium.

Recorded distribution in Britain and Ireland

Ophelia borealis is widespread around the British Isles but less common on the Irish coasts.

Global distribution



Ophelia borealis inhabits clean sand in the subtidal and intertidal zones up to high water.

Depth range


Identifying features

  • Stout, body with approximately 30 segments.
  • Body is widest at tenth segment and up to 2.3 cm in length.
  • Deep pinkish, red colour with a lilac or blue iridescent tint.
  • Segments marked with 5-7 superficial rings.
  • Chaetae slender, unjointed, and shorter on the neuropodia than the notopodia.
  • Abdominal region distinguished by a deep ventral groove commencing at the seventh segment, two lateral grooves and chaetae-like gills.
  • Numerous papillae cover the pygidium.

Additional information

This species is similar to Ophelia limacina.

Listed by

- none -


  1. Bruce, J.R., Colman, J.S. & Jones, N.S., 1963. Marine fauna of the Isle of Man. Liverpool: Liverpool University Press.

  2. Costello, M.J., Bouchet, P., Boxshall, G., Emblow, C. & Vanden Berghe, E., 2004. European Register of Marine Species [On-line]. http://www.marbef.org/data/erms.php,

  3. Foster-Smith, J. (ed.), 2000. The marine fauna and flora of the Cullercoats District. Marine species records for the North East Coast of England. Sunderland: Penshaw Press, for the Dove Marine Laboratory, University of Newcastle upon Tyne.

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

  5. 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.]

  6. Tebble, N. 1952. On three species of the Genus Ophelia (Polychaeta) from British & adjacent waters. The Annals and Magazine of Natural History Vol 5 Series 12, 553-560.


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

  2. OBIS (Ocean Biodiversity Information System),  2024. Global map of species distribution using gridded data. Available from: Ocean Biogeographic Information System. www.iobis.org. Accessed: 2024-05-18


This review can be cited as:

Richards, S. 2007. Ophelia borealis A bristleworm. 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 18-05-2024]. Available from: https://www.marlin.ac.uk/species/detail/22

Last Updated: 12/09/2007