MarLIN

information on the biology of species and the ecology of habitats found around the coasts and seas of the British Isles

A sea slug (Onchidoris bilamellata)

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

Summary

Description

Onchidoris bilamellata can grow to 4 cm in length and are usually white with a brown pattern on the mantle. However immature specimens and the occasional adult may be completely white in colour. It bears many (usually white) club shaped projections (tubercles) on its mantle and has two ringed sensory tentacles on its head. The numerous (up to 29) retractile gills are speckled brown around the edges and arranged in a horseshoe shape. The head extends to form an oral veil which lacks tentacles. The spawn is in the shape of a flattered coil attached to the substratum by one edge and contains many thousand eggs.

Recorded distribution in Britain and Ireland

Recorded all around Britain and Ireland.

Global distribution

Its range in the eastern Pacific is from Alaska to Baja California, Mexico. Occurs in the eastern and western Atlantic basins. Widely distributed in north west Europe reaching its southern limit on the French Atlantic coast.

Habitat

Onchidoris bilamellata can be found in the intertidal and shallow sublittoral, to a depth of 20 m.

Depth range

-

Identifying features

  • Grows up to 4 cm in length.
  • Dirty white colour with a brown pattern.
  • Horseshoe shaped gills.
  • Club shaped projections (usually white) on the mantle.

Additional information

This species produces acid secretions from the mantle when disturbed. It is gregarious and feeds exclusively on barnacles, especially Semibalanus balanoides.

Listed by

- none -

Further information sources

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Bibliography

  1. Hayward, P.J. & Ryland, J.S. (ed.) 1995a. The marine fauna of the British Isles and north-west Europe. Volume 2. Molluscs to Chordates. Oxford Science Publications. Oxford: Clarendon Press.

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

  5. Picton, B.E., 2000. Nudibranchs of the British Isles. http://www.pictonb.freeserve.co.uk/nudibranchs/index.html, 2003-09-11

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

Datasets

  1. Centre for Environmental Data and Recording, 2018. IBIS Project Data. Occurrence dataset: https://www.nmni.com/CEDaR/CEDaR-Centre-for-Environmental-Data-and-Recording.aspx accessed via NBNAtlas.org on 2018-09-25.

  2. 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.

  3. 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.

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

  5. Environmental Records Information Centre North East, 2018. ERIC NE Combined dataset to 2017. Occurrence dataset: http://www.ericnortheast.org.uk/home.html accessed via NBNAtlas.org on 2018-09-38

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

  7. Fife Nature Records Centre, 2018. St Andrews BioBlitz 2015. Occurrence dataset: https://doi.org/10.15468/xtrbvy accessed via GBIF.org on 2018-09-27.

  8. Kent Wildlife Trust, 2018. Kent Wildlife Trust Shoresearch Intertidal Survey 2004 onwards. Occurrence dataset: https://www.kentwildlifetrust.org.uk/ accessed via NBNAtlas.org on 2018-10-01.

  9. Manx Biological Recording Partnership, 2017. Isle of Man wildlife records from 01/01/2000 to 13/02/2017. Occurrence dataset: https://doi.org/10.15468/mopwow accessed via GBIF.org on 2018-10-01.

  10. Merseyside BioBank., 2018. Merseyside BioBank (unverified). Occurrence dataset: https://doi.org/10.15468/iou2ld accessed via GBIF.org on 2018-10-01.

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

  12. OBIS,  2018. Global map of species distribution using gridded data. Available from: Ocean Biogeographic Information System. www.iobis.org. Accessed: 2018-11-15

  13. South East Wales Biodiversity Records Centre, 2018. SEWBReC Molluscs (South East Wales). Occurrence dataset: https://doi.org/10.15468/jos5ga accessed via GBIF.org on 2018-10-02.

  14. South East Wales Biodiversity Records Centre, 2018. Dr Mary Gillham Archive Project. Occurance dataset: http://www.sewbrec.org.uk/ accessed via NBNAtlas.org on 2018-10-02

  15. Yorkshire Wildlife Trust, 2018. Yorkshire Wildlife Trust Shoresearch. Occurrence dataset: https://doi.org/10.15468/1nw3ch accessed via GBIF.org on 2018-10-02.

Citation

This review can be cited as:

Edwards, R.V. 2004. Onchidoris bilamellata A sea slug. In Tyler-Walters H. and Hiscock K. (eds) Marine Life Information Network: Biology and Sensitivity Key Information Reviews, [on-line]. Plymouth: Marine Biological Association of the United Kingdom. [cited 15-11-2018]. Available from: https://www.marlin.ac.uk/species/detail/1974

Last Updated: 08/04/2004