A brittlestar (Ophiopsila aranea)

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



Ophiopsila aranea are a red/brown colour and covered in tiny white spots. Extending from a central disc are five radial arms. The disc diameter can reach 15 mm, has no scales and is slightly granular. The arms are proportional to the disc, being approximately seven times the diameter. The arms are formed from small, straight and separate radial shields and are rounded towards the tips. Along each side of each arm are six to eight spines. The dorsal plates of the elongated arms are oval in shape and the ventral plates have slightly concave outer edges. There are two mouth papillae (teeth) on each side of the jaw which curve slightly outwards.

Recorded distribution in Britain and Ireland

Ophiopsila aranea is a nationally rare but locally abundant species which can be found in the Plymouth area, for example, in crevices on the Mewstone Ledges.

Global distribution



Ophiopsila aranea are found on hard substratum, usually in crevices at depths of 25 to 185 m.

Depth range


Identifying features

  • The disc has no scales
  • Radial shields thin and linear.
  • The arms are proportionally long in relation to the disc.
  • Six to eight spines along each side of each arm.

Additional information

Both the disc and arms of very fragile and can be easily dislocated. Ophiopsila aranea are commonly found in crevices with the long arms protruding out into water.

Ophiopsila aranea may be easily confused with the similar looking Ophiopsila annulosa, which has 11-12 spines on each side of each arm.

Listed by

- none -


  1. Gibson, R., Hextall, B. & Rogers, A., 2001. Photographic guide to the sea and seashore life of Britain and 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. MBA (Marine Biological Association), 1957. Plymouth Marine Fauna. Plymouth: Marine Biological Association of the United Kingdom.

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

  5. Ruppert, E.E. & Barnes, R.D., 1994. Invertebrate zoology (6th ed.). Fort Worth, USA: Saunders College Publishing.

  6. Stachowitsch, M., 1992. The invertebrates: an illustrated glossary. USA: Wiley-Liss.


  1. Isle of Wight Local Records Centre, 2017. IOW Natural History & Archaeological Society Marine Invertebrate Records 1853- 2011. Occurrence dataset: https://doi.org/10.15468/d9amhg accessed via GBIF.org on 2018-09-27.

  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: 2024-06-24


This review can be cited as:

Heard, J.R. 2007. Ophiopsila aranea A 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 24-06-2024]. Available from: https://marlin.ac.uk/species/detail/2098

Last Updated: 07/06/2007