A barnacle (Hesperibalanus fallax)

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



Hesperibalanus (syn. Solidobalanus) fallax is a small barnacle reaching 12 mm in diameter, typically epibiotic and found in shallow seas. The shell comprises six poreless shell plates (parietes) and a poreless calcareous base. The shell plates are generally white with reddish-purple patches. The opercular membrane bears brown or black banding on a yellow field.

Recorded distribution in Britain and Ireland

In the British Isles, Solidobalanus fallax has only been recorded from the southwest coasts of England and Wales.

Global distribution

Considered native to the Atlantic Coast of tropical Africa, Solidobalanus fallax is considered to have extended its range North through Portugal and France to Belgium and the Netherlands.


Solidobalanus fallax is typically epibiotic on a wide range of organisms including other crustaceans, hydroids, algae and molluscs. It has also been recorded from man-made objects such as plastics and lobster pots. Solidobalanus fallax is found in the upper sublittoral to around 200 m.

Depth range


Identifying features

  • Shell almost globose, with thin walls.
  • Basis and shell plates without pores.
  • Lateral projections on shell plates sloped, giving the orifice a toothed look.
  • Opercular membrane yellow with brown or black banding.

Additional information

Hesperibalanus fallax is considered to be non-native within the British Isles as well as northern Europe believed to have relatively recently expanded its range northward from Africa.

Listed by

- none -



    1. Cofnod – North Wales Environmental Information Service, 2018. Records of Invasive Non Native Species held on the Cofnod database. Occurrence dataset: https://doi.org/10.15468/nxdbhu accessed via GBIF.org on 2018-09-25.

    2. Fenwick, 2018. Aphotomarine. Occurrence dataset http://www.aphotomarine.com/index.html Accessed via NBNAtlas.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: 2024-05-21


    This review can be cited as:

    Hosie, A.M. 2008. Hesperibalanus fallax A barnacle. In Tyler-Walters H. Marine Life Information Network: Biology and Sensitivity Key Information Reviews, [on-line]. Plymouth: Marine Biological Association of the United Kingdom. [cited 21-05-2024]. Available from: https://www.marlin.ac.uk/species/detail/2304

    Last Updated: 07/10/2008