A bristleworm (Sternaspis scutata)

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



Sternaspis scutata is a stout burrowing worm, whitish-grey in colour, with a leathery texture. Its body is up to 3.5 cm in length and 1-1.5 cm wide. The body is divided into 20-22 segments, the first seven forming the anterior region, the remainder forming the posterior region. The anterior region is much smaller and narrower than the posterior region into which it can withdraw. The head is reduced and bears a small translucent rounded prostomium above the mouth. The first segment behind the head forms a peristomium that is covered by short papillae. The 2nd-4th segments are each marked by a row of dark spines on either side. Two tubular papillae mark the division between the anterior and posterior region at the 7th and 8th segments. The remaining posterior segments are covered on the ventral surface by a pair of brown stiff plates that both bear a bundle of 15-17 chaetae that are much longer and more noticeable than the notochaetae. Numerous long, slender, occasionally spiralled gills extend from the posterior.

Recorded distribution in Britain and Ireland

Sternaspis scutata is a rare species only recorded along the south Devon coast, from Plymouth Sound to Otterton Point, and in Dorset at Portland Harbour.

Global distribution

Sternaspis scutata is widely distributed and has been recorded from the Arctic, North Sea, Mediterranean Sea, Pacific Ocean, south Atlantic Ocean and Antartica.


Sternaspis scutata inhabits sandy and muddy substrata, where it burrows head-down, exposing the gills on its posterior end.

Depth range


Identifying features

  • Stout worm up to 3.5 cm long and 1-1.5 cm wide.
  • Body divided into 20-22 segments that are not visible in the mid-ventral posterior region.
  • Row of dark spines on either side of 2nd-4th segments.
  • Two tubular papillae present on 7th-8th segment.
  • Two stiff, brown-coloured plates, each bearing 15-17 chaetae, cover the ventral surface of the most posterior segments.
  • Main body whitish-grey in colour.

Additional information

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Listed by

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  1. Bartolomaeus, T. 1992. On the ultrastructure of the cuticle, the epidermis and the gills of Sternaspis scutata (Annelida). Microfauna Marina, 7, 237-253.

  2. Blake, J.A., Hilbig, B., and Scott, P.V., 2000. Taxonomic Atlas of the benthic fauna of the Santa Maria Basin and Western Santa Barbara Channel. Volume 7. The Annelida Part 4. Polychaeta: Flabelligeridae to Sternaspidae. Santa Barbara, California: Santa Barbara Museum of Natural History.

  3. Campbell, A.C., 1982. The Hamlyn guide to the flora and fauna of the Mediterranean Sea. London: Hamlyn.

  4. Crothers, J. A., 1997. A key to the major groups of British marine invertebrates. Field Studies, 9, 1-177.

  5. Day, J.H., 1967. A monograph on the Polychaeta of Southern Africa. Vol.1 - Errantia; Vol.2 - Sedentaria. London: British Museum (Natural History).

  6. 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.]

  7. Shelley, R., Widdicombe, S., Woodward, M., Stevens, T., McNeill, C.L. & Kendall, M.A. 2008. An investigation of the impacts on biodiversity and ecosystem functioning of soft sediments by the non-native polychaete Sternaspis scutata (Polychaeta: Sternaspidae). Journal of Experimental Marine Biology and Ecology, 366, 146-150.


  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: 2024-05-18


This review can be cited as:

Richards, S. 2007. Sternaspis scutata 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/24

Last Updated: 12/09/2007