A sea slug (Atagema gibba)

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



A sea slug that grows up to 68mm in length. The body is chocolate brown in colour and has small white protrusions all over it to form a net-like pattern which feels stiff and velvety to the touch. It has finger-like oral tentacles on the head.

Recorded distribution in Britain and Ireland

The Lizard peninsula, Cornwall and the east coast of St. Mary's in the Scilly Isles.

Global distribution



Found on steep rock faces in 8-15 m depth.

Depth range


Identifying features

  • Aspect of body flattened but there is a conspicuous elevated zig-zag dorsal pallial ridge from between the rhinophores to the gills.
  • Mantle rim usually loosely crenulated.
  • Trumpet shaped rhinophores and a 5-lipped gill pocket.
  • Distinctive reticulate pattern of tubercles.

Additional information

No text entered

Listed by

- none -


  1. 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.]

  2. Picton, B. E. & Morrow, C.C., 1994. A Field Guide to the Nudibranchs of the British Isles. London: Immel Publishing Ltd.

  3. Thompson, T. E. & Brown, G. H., 1976. British Opisthobranch Molluscs. London: Academic Press. [Synopses of the British Fauna, no. 8.]


  1. Conchological Society of Great Britain & Ireland, 2018. Mollusc (marine) records for Great Britain and Ireland. Occurrence dataset: https://doi.org/10.15468/aurwcz accessed via GBIF.org on 2018-09-25.

  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: 2024-05-25


This review can be cited as:

Wilson, E. 2004. Atagema gibba A sea slug. 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 25-05-2024]. Available from: https://marlin.ac.uk/species/detail/1254

Last Updated: 10/08/2004