species: Briareum violaceum cf. in Lizard Island Field Guide (Lizard Island Field Guide)
Briareum violaceum cf.

©Stefano Borghi: Briareum violaceum cf. at Mermaid Cove, Lizard Island.

©Andy Lewis: A colony of Briareum at Lizard Island. The purple colour suggests Briareum violaceum but sclerites need to be examined for definitive species identification.

©Andy Lewis: Polyps of Briareum, possibly Briareum violaceum.
Kingdom Animalia
Phylum Cnidaria
Class Octocorallia
Order Scleralcyonaceae
Family Briareidae
Genus Briareum
Species Briareum violaceum cf.

Distinguishing features

Three species of Briareum are known from the central Indo-west Pacfic (Samimi-Namin and van Ofwegen, 2016). They are distinguished mainly on sclerite shape and size, so identification of living specimens is hazardous. The identifications provided in this field guide are tentative ones provided by experts or students of the group.

Briareum species have a thin encrusting morphology, with the colony surface often raised into protruding lumps. Polyps are monomorphic and retractile, with considerable variation in characteristics. In some specimens, polyps hardly protrude, while in others, polyps may be 15 mm tall with a distinct oral disk. Colonies may be several meters in area, and mono-specific stands extending over many tens of meters have been reported from some inshore reefs.

In Briareum violaceum, all sclerites are magenta, unlike Briareum stechei which has both magenta and colourless sclerites (Samimi-Namin and van Ofwegen, 2016).


  • Size data has not been obtained.



©Atlas of Living Australia: Australian distribution

Web resources


References that assist with identification

  • Samimi-Namin, K. and L.P. van Ofwegen (2016). Overview of the genus Briareum (Cnidaria, Octocorallia, Briareidae) in the Indo-Pacific, with the description of a new species. Zookeys, 577: 1-44. LIRS catalog number 90281.

Other references

  • Burghardt, I., J. Evertsen, G. Johnsen and H. Waegele (2005). Solar powered sea slugs - mutualistic symbiosis of aeolid Nudibranchia (Mollusca, Gastropoda, Opisthobranchia) with Symbiodinium, Symbiosis, 38: 227-250. LIRS catalog number 916.
  • Burghardt, I., K. Stemmer and H. Waegele (2008). Symbiosis between Symbiodinium (Dinophyceae) and various taxa of Nudibranchia (Mollusca: Gastropoda), with analysis of long-term retention, Organisms, Diversity and Evolution, 8: 66-76. LIRS catalog number 1125.
  • View all references