A sea slug (Aeolidiella sanguinea)

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



A sea slug with an orange brown body which is covered by an extensive fawn or light brown surface pigment, with a rim around the edge of the foot. It has numerous protrusions along its body (cerata) that are also covered with dense flecks of fawn coloured pigment. Aeolidiella sanguinea grows up to 46 mm.

Recorded distribution in Britain and Ireland

A nationally rare species, recorded from Lough Hyne, Galway Bay and Donegal Bay in Ireland and from the Calf of Man, Isle of Man.

Global distribution



Typically a sublittoral species but occasionally found on the lower shore in muddy inlets but also on exposed rocky coasts.

Depth range


Identifying features

  • Superficial pigment on ceratal surfaces and around edge of foot.
  • The hear bears sensory tentacles (rhinophores) and oral tentacles with outer portion pigmented.
  • Rhinophores, cerata and oral tentacles bear white tips.

Additional information

This species feeds on Sagartiid anemones, especially Cylista elegans (Picton & Morrow, 1994).


  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., 1984. Biology of Opisthobranch Molluscs, vol. II. London: Ray Society.


  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. Manx Biological Recording Partnership, 2018. Isle of Man historical wildlife records 1990 to 1994. Occurrence dataset:https://doi.org/10.15468/aru16v accessed via GBIF.org on 2018-10-01.

  3. NBN (National Biodiversity Network) Atlas. Available from: https://www.nbnatlas.org.

  4. OBIS (Ocean Biodiversity Information System),  2024. Global map of species distribution using gridded data. Available from: Ocean Biogeographic Information System. www.iobis.org. Accessed: 2024-06-15


This review can be cited as:

Wilson, E. 2006. Aeolidiella sanguinea 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 15-06-2024]. Available from: https://marlin.ac.uk/species/detail/1260

Last Updated: 14/08/2006