A sea slug (Calliopaea bellula)

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



A sea slug that can grow up to 1 cm in length. It is greyish in colour, marbled with white, while the tail is pale red. It has protrusions arranged in five or six rows along the sides of the body.

Recorded distribution in Britain and Ireland

South coast of Britain, Northern Ireland, and the east and west coasts of Ireland, County Down and Kerry respectively.

Global distribution



Found in shallow water, perhaps associated with Zostera.

Depth range


Identifying features

  • Length 1 cm.
  • Rhinophores grey.
  • Cerata arranged in 5 or 6 rows along sides of dorsum.
  • Anal opening antero-dorsal.

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. JNCC (Joint Nature Conservation Committee), 1999. Marine Environment Resource Mapping And Information Database (MERMAID): Marine Nature Conservation Review Survey Database. [on-line] http://www.jncc.gov.uk/mermaid

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


  1. Fenwick, 2018. Aphotomarine. Occurrence dataset http://www.aphotomarine.com/index.html Accessed via NBNAtlas.org on 2018-10-01

  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: 2024-05-18


This review can be cited as:

Wilson, E. 2005. Calliopaea bellula 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 18-05-2024]. Available from: https://www.marlin.ac.uk/species/detail/1250

Last Updated: 02/11/2005