Uncommon to rare in the Solitary Islands Marine Park. Distributed throughout the Indo-Pacific region: from East Africa to Pitcairn, north to the Ryuku Islands, south to Tonga and Rapa. In Australia recorded from the Coral Sea and southern Great Barrier Reef in Queensland, northern New South Wales and including Lord Howe Island.
Frequents surge zones of clear rocky shorelines, shallow exposed reef, usually with a mix of rocky substrate with coral and algae. Depth 0 - 10 m.
Distinguished from similar Surge Wrasse, Thalassoma purpureum by the plain brown/orange head. Females have a spotted head and lack the "V" shaped mark on the snout, see lower photograph, male in top photograph. Found solitary or in small groups. Feeds on crustaceans, molluscs and brittle stars. Grows to 30 cm.
R. Stuart-Smith, G. Edgar, A. Green, I. Shaw, Tropical Marine Fishes of Australia. Reed New Holland Publishers, 2015. p.340.
Atlas of Living Australia website at https://bie.ala.org.au/search?q=thalassoma+trilobatum. Accessed 11/07/18.
FishBase. Froese, R. and D. Pauly. Editors. 2018. World Wide Web electronic publication. https://fishbase.ca/summary/Thalassoma-trilobatum.html. Accessed 11/07/18.