Wart barnacle (Verruca stroemia)

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



Verruca stroemia is a small grey box-like barnacle growing up to 1 cm in diameter. This species is distinguished from other barnacles present in Britain and Ireland by its assymmetrical 4 plated shell wall, with strong interlocking sutures. Instead of the paired moveable opercular valves of typical barnacles, half of the operculum is fixed to the substrate, while the other half forms a hinged 'lid'.

Recorded distribution in Britain and Ireland

Widespread in British and Irish seas.

Global distribution

Verruca stroemia has been recorded along the Atlantic coast of Europe from southern Portugal to the White Sea, including Svalbard.


Verruca stroemia is found between extreme low water and 500 m depth. It can be found on rocky shores attached to the undersides of rocks and in crevices.

Depth range


Identifying features

  • Shell flattened, wall comprised of 4 plates (rostrum, carina, tergum, scutum).
  • Shell plates with longitudinal ridges and serrated sutures.
  • Operculum lid-like.
  • Membranous base.

Additional information

The related species Verruca spengleri found from the Azores to the Black Sea has often been confused with Verruca stroemia, which led to erroneous records of Verruca stroemia present in the Mediterranean (see Young et al., 2003). Verruca spengleri has pores permeating the external shell wall and the shell plates (parietes) lack longitudinal ridges, distinguishing it from Verruca stroemia.

Listed by

- none -



    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. Cofnod – North Wales Environmental Information Service, 2018. Miscellaneous records held on the Cofnod database. Occurrence dataset: https://doi.org/10.15468/hcgqsi accessed via GBIF.org on 2018-09-25.

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

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

    5. Fife Nature Records Centre, 2018. St Andrews BioBlitz 2014. Occurrence dataset: https://doi.org/10.15468/erweal accessed via GBIF.org on 2018-09-27.

    6. 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.

    7. Fife Nature Records Centre, 2018. St Andrews BioBlitz 2016. Occurrence dataset: https://doi.org/10.15468/146yiz accessed via GBIF.org on 2018-09-27.

    8. Kent Wildlife Trust, 2018. Biological survey of the intertidal chalk reefs between Folkestone Warren and Kingsdown, Kent 2009-2011. Occurrence dataset: https://www.kentwildlifetrust.org.uk/ accessed via NBNAtlas.org on 2018-10-01.

    9. 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.

    10. National Trust, 2017. National Trust Species Records. Occurrence dataset: https://doi.org/10.15468/opc6g1 accessed via GBIF.org on 2018-10-01.

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

    12. OBIS (Ocean Biodiversity Information System),  2023. Global map of species distribution using gridded data. Available from: Ocean Biogeographic Information System. www.iobis.org. Accessed: 2023-12-10

    13. South East Wales Biodiversity Records Centre, 2018. SEWBReC Myriapods, Isopods, and allied species (South East Wales). Occurrence dataset: https://doi.org/10.15468/rvxsqs accessed via GBIF.org on 2018-10-02.

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


    This review can be cited as:

    Hosie, A.M. 2008. Verruca stroemia Wart barnacle. 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 10-12-2023]. Available from: https://marlin.ac.uk/species/detail/2228

    Last Updated: 09/10/2008