Gravel brittlestar (Ophiopsila annulosa)

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



Ophiopsila annulosa displays the characteristic brittle star body plan with a flat central disc and five distinctly demarcated thin arms. As a member of the order Ophiurida, its arms are usually moved horizontally and the discs and arms are covered with scales. The circular disc can reach 22 mm in diameter, while the arms reach up to 13 cm in length. It has both tooth and mouth papillae, a smooth dorsal disc area and notably wiry arms. It has about twelve arm spines per segment. The disc is mottled reddish brown and white in colour. The arms are very distinctly banded brown and white.

Recorded distribution in Britain and Ireland

Found at several locations around western Britain and Ireland including Plymouth in Devon, near Bantry in County Cork, Connemara in County Galway and in Inverness-shire, Scotland.

Global distribution



Ophiopsila annulosa is a benthic sublittoral species that can usually be found burrowing in coarse gravel and sand at depths of around 30 m.

Depth range


Identifying features

  • Disc up to 22 mm in diameter.
  • Arms up to 13 cm in length.
  • Wiry arms and robust body.
  • Dorsal side of disc is smooth with very small scales.
  • Twelve small arm spines per arm segment and no row of papillae at the base of each arm.
  • Tooth papillae and two mouth papillae are present.

Additional information

It can be differentiated from Ophiopsila aranea by having about twelve arm spines and by being more robust.


  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.]

  3. Mortensen, T.H., 1927. Handbook of the echinoderms of the British Isles. London: Humphrey Milford, Oxford University Press.

  4. Picton, B.E., 1993. A field guide to the shallow-water echinoderms of the British Isles. London: Immel Publishing Ltd.

  5. Southward, E.C. & Campbell, A.C., 2006. Echinoderms. The Linnean Society of London. Avon: The Bath Press. [Synopses of the British Fauna No. 56.]


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

  2. 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. Ophiopsila annulosa Gravel brittlestar. 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