A peanut worm (Nephasoma (Nephasoma) rimicola)

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



Nephasoma rimicola, like all sipunculid worms, has an unsegmented body consisting of an introvert and a trunk. The introvert can be withdrawn into the trunk. The mouth, which is on the end of the introvert, is surrounded by up to 16 tentacles. Nephasoma rimicola, has a trunk at least three times as long as it is wide, about the same length of the introvert. The introvert is covered by many spine-like hooks at the anterior end. The body may reach up to 6 cm in length and colouration is extremely variable. Nephasoma rimicola has well formed oral tentacles and the introvert hooks are arranged in rings.

Recorded distribution in Britain and Ireland

Found at several locations of the south-west coasts of Britain, including the mouth of the Exe estuary, Bideford in north Devon and Milford Haven on south coast of Pembrokeshire and west of the Isle of Wight.

Global distribution



Nephasoma rimicola is a benthic species often on found in lower shore rock crevices.

Depth range


Identifying features

  • Up to 6 cm in length.
  • Trunk without shields.
  • Well formed tentacles entirely surround the mouth.
  • Dorsal pair of retractor muscles are absent.
  • Two internal kidney-like organs (nephridia).
  • Nephridiopores anterior to anus.

Additional information

Unlike Nephasoma minutum, Nephasoma rimicola has well formed oral tentacles and the introvert hooks are arranged in rings (Cutler, 1994).

Listed by

- none -


  1. Cutler, E.B., 1994. The Sipuncula. Their systematics, biology and evolution. Ithaca, Cornell University Press.

  2. Gibbs, P.E., 1986. The taxonomy of some little-known Sipuncula from the North-East Atlantic region including new records. Journal of the Marine Biological Association of the United Kingdom, 66, 335-341

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

  4. 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. 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: 2024-04-23


This review can be cited as:

Barnes, M.K.S. 2008. Nephasoma (Nephasoma) rimicola A peanut 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 23-04-2024]. Available from: https://www.marlin.ac.uk/species/detail/120

Last Updated: 22/05/2008