A peanut worm (Nephasoma (Nephasoma) minutum)

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



Nephasoma minutum, 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 The introvert can be withdrawn into the trunk.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. The trunk is at least three times as long as it is wide and about the same length of the introvert. The introvert is covered by many spine-like hooks at the anterior end. Nephasoma minutum may reach up to 1.5 cm in length. It is very variable in colour, from grey-yellow to orange or pure white. The oral tentacles of Nephasoma minutum are largely rudimentary and the introvert hooks are arranged irregularly. The oral disc has two distinct lobes.

Recorded distribution in Britain and Ireland

Found throughout the British Isles and off north-east Ireland.

Global distribution



Nephasoma minutum is a benthic species often found in rock crevices on the lower shore or sublittorally but may also occur in mud, sand or gravel.

Depth range


Identifying features

  • Up to 1.5 cm in length.
  • Trunk without shields.
  • Tentacles entirely surround the mouth but are rudimentary.
  • Dorsal pair of retractor muscles are absent.
  • Two internal kidney-like organs (nephridia).
  • Nephridiopores posterior to anus.

Additional information

Unlike Nephasoma rimicola, Nephasoma minutum has only rudimentary oral tentacles the introvert hooks are arranged irregularly and the oral disc has two distinct lobes (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.]

  5. Stephen, A.C. & Edmonds, S.J., 1972. The Phyla Sipuncula and Echiura. London, Trustees of the British Museum (Natural History).


  1. Environmental Records Information Centre North East, 2018. ERIC NE Combined dataset to 2017. Occurrence dataset: http://www.ericnortheast.org.ukl accessed via NBNAtlas.org on 2018-09-38

  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: 2024-04-23

  4. South East Wales Biodiversity Records Centre, 2018. SEWBReC Worms (South East Wales). Occurrence dataset: https://doi.org/10.15468/5vh0w8 accessed via GBIF.org on 2018-10-02.


This review can be cited as:

Barnes, M.K.S. 2008. Nephasoma (Nephasoma) minutum 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/119

Last Updated: 22/05/2008