A sea slug (Amphorina farrani)

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



Eubranchus farrani is very variable in colour. It usually has a translucent white body, with orange tipped rhinophores and oral tentacles. The white inflated cerrata have conspicuous sub-terminal orange or yellow rings. Some colour variants show individual exaggeration of certain markings. Others may have orange blotches ringed with blue. An all white form is common. Juveniles may have no colour other than pale brown or salmon pink. The cerrata are arranged in up to 10 diagonal rows of up to 5 cerrata in each half row. Oral tentacles and rhinophores are similar in size and relatively short. The maximum length for Eubranchus farrani is 2 cm.

Recorded distribution in Britain and Ireland

Recorded from most British coasts.

Global distribution

Recorded from Norway and the Atlantic coast of France, to the western Mediterranean Sea.


Found on rocky shores in the shallow sublittoral down to 30 m. Feeds on thecate hydroids such as Obelia geniculata.

Depth range


Identifying features

  • Up to 2 cm extended length.
  • Typical coloration is translucent white body with orange tipped rhinophores and oral tentacles.
  • Other colour morphs exist.
  • Cerrata arranged in up to 10 diagonal rows of up to 5 cerrata in each half row.
  • Oral tentacles and rhinophores are similar in size and relatively short.
  • Broad propodial part of foot projects on each side of the head.

Additional information

The spawn is a laid in a spiral ribbon of about 2 turns, flared out on its upper margin. Eubranchus farrani has in the past been confused with Eubranchus tricolour. However, Eubranchus farrani is more slender and smaller, with fewer cerata of less compressed shape, and different colour patterns (Thompson & Brown, 1984).

Listed by

- none -


  1. Hayward, P., Nelson-Smith, T. & Shields, C. 1996. Collins pocket guide. Sea shore of Britain and northern Europe. London: HarperCollins.

  2. 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.]

  3. 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

  4. MarLIN (Marine Life Information Network), 2005. SEArchable BEnthic Data (SEABED) Map [on-line]. Data Access Sub-programme, Marine Life Information Network for Britian and Ireland http://www.marlin.ac.uk,

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

  6. Rudman, W.B., 2003. Eubranchus farrani [on-line]. http://www.seaslugforum.net/factsheet.cfm?base=eubrfarr,

  7. Thompson, T.E. & Brown, G.H., 1984. Biology of Opisthobranch Molluscs, vol. II. London: Ray Society.


  1. Centre for Environmental Data and Recording, 2018. Ulster Museum Marine Surveys of Northern Ireland Coastal Waters. Occurrence dataset https://www.nmni.com/CEDaR/CEDaR-Centre-for-Environmental-Data-and-Recording.aspx accessed via NBNAtlas.org on 2018-09-25.

  2. Conchological Society of Great Britain & Ireland, 2018. Mollusc (marine) data for Great Britain and Ireland - restricted access. Occurrence dataset: https://doi.org/10.15468/4bsawx accessed via GBIF.org on 2018-09-25.

  3. 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.

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

  5. 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.

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

  7. Norfolk Biodiversity Information Service, 2017. NBIS Records to December 2016. Occurrence dataset: https://doi.org/10.15468/jca5lo accessed via GBIF.org on 2018-10-01.

  8. 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:

Oakley, J.A. 2008. Amphorina farrani 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/2149

Last Updated: 24/04/2008