Volcano worm (Maxmuelleria lankesteri)

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



Maxmuelleria lankesteri is a large spoon worm with a stout, sac-like body and long, tubular proboscis. The body is covered in round bumps (papillae) while the proboscis is smooth, strap-like and typically rounded at the tip. The animal is green, with a vivid colour to its body and a paler shade to its proboscis, but dead specimens appear a dirty grey. Both the body and proboscis are extensible so the recorded size varies. In its contracted form, the worm can be up to 18 cm in length but the length is almost doubled when the proboscis is fully extended. 

Recorded distribution in Britain and Ireland

Found off the east and south coasts of England and Wales including the Irish Sea, with the majority of records concentrated off the west coast of Scotland.

Global distribution

Maxmuelleria lankesteri is limited to a few locations outside of the UK. It has been recorded between Norway and Sweden in the Skagerrak and Kattegat, whilst in the western Atlantic, it has been recorded off the coast of eastern USA, adjacent to New Jersey. In the Southern Hemisphere, Maxmuelleria lankesteri is found at a single location off the coast of Namibia.  


Maxmuelleria lankesteri are sedentary, sediment dwelling worms. They occupy U-shaped burrows in a variety of substrata, most commonly in fine muds to muddy sands. The burrows fashion an opening at each end, one of which forms the crater of a volcano-shaped mound of mud. Spoon worms are found at depths ranging from the intertidal zone to the deep sea. The burrow itself can extend to 80 cm deep within the sediment with up to 2 m between the openings.

Depth range

0 – 3975 m

Identifying features

  • Stout, sac-like body.
  • Ribbon-like proboscis with rounded tip.
  • Body and proboscis extensible.
  • Body wall is vivid dark green and covered in dermal papillae.
  • Proboscis is paler green and lacks papillae.
  • Up to 18 cm in length when contracted.

Additional information

A muddy mound is located at the opening of the burrow and is formed by the expulsion of fluidized sediment from inside the burrow. Hence, the worm’s common name, ‘the Volcano Worm’. The second, less conspicuous burrow opening is used as an exit for the extension of the proboscis whilst deposit-feeding. The proboscis makes tracks which are often visible in the sediment surrounding the hole and used by surveyors to detect the presence of the nocturnally feeding spoon worm.

Maxmuelleria lankesteri is closely related and similar in appearance to the Mediterranean species, Maxmuelleria gigas. They are thought to be distinguished only by the distribution of their papillae, which in Maxmuelleria gigas are thought to be more concentrated on the anterior and posterior surfaces of the trunk, in comparison to a more uniform distribution in Maxmuelleria lankesteri

Listed by

- none -


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

  2. Hughes, D. J., Ansell, A.D. & Atkinson, R.J.A., 1994. Resource utilization by a sedentary surface deposit feeder, the echiuran worm Maxmuelleria lankesteri. Marine Ecology Progress Series, 112, 267-275.

  3. Hughes, D. J., Ansell, A.D. & Atkinson, R.J.A., 1996. Distribution, ecology and life cycle of Maxmuelleria lankesteri (Echiura: Bonelliidae): a review with notes on field identification. Journal of the Marine Biological Association of the United Kingdom, 76, 897-908.

  4. Hughes, D.J., Ansell, A.D. & Atkinson, R.J.A., 1996. Sediment bioturbation by the echiuran worm Maxmuelleria lankesteri (Herdman) and its consequences radionuclide dispersal in Irish Sea sediments. Journal of Experimental Marine Biology and Ecology, 195 (2), 203-220.

  5. McHugh, D., 1997. Molecular evidence that echiurans and pogonophorans are derived annelids. Proceedings of the National Academy of Sciences of the United States of America, 94 (15), 8006-8009.

  6. Nickell, L.A., Atkinson, R.J.A., Hughes, D.J., Ansell, A.D. & Smith, C.J. 1995. Burrow morphology of the echiuran worm Maxmuelleria lankesteri (Echiura: Bonelliidae), and a brief review of the burrow structure and related ecology of the Echiura. Journal of Natural History, 29, 871-885.

  7. Stephen, A.C., 1960. British echiurids (Echiuroidea), sipunculids (sipunculoidea) and priapulids (Priapuloidea) With keys and notes for the identification of species,  London: Linnean Society of London.

  8. Struck, T.H., Schult, N., Kusen, T., Hickman, E., Bleidorn, C., McHugh, D. & Halanych, K.M., 2007. Annelid phylogeny and the status of Sipuncula and Echiura. BMC Evolutionary Biology, 7 (1), 57.


  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: 2024-05-20


This review can be cited as:

Wilson, C.M. 2018. Maxmuelleria lankesteri Volcano 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 20-05-2024]. Available from: https://www.marlin.ac.uk/species/detail/2316

Last Updated: 01/01/2018