Pomacanthus semicirculatus (Cuvier, 1831)
Uncommon in the Solitary Islands Marine Park. Distributed throughout the Indo-West Pacific region: from the Red Sea and East Africa to Samoa, north to southern Japan and south to Australia.
In Australia recorded from Geraldton north to at least the Dampier Archipelago in Western Australia, throughout the Great Barrier Reef in Queensland south to northern New South Wales and including Lord Howe Island.
Adults frequent coral rich areas on coastal reefs, juveniles generally in shallower protected areas. Depth 1 - 40 m.
Adults with blue colour at front and rear of body, centre with blue scale centres on yellowish background, blue around the eye and blue markings on operculum and opercular spine. Juveniles markedly different to adult, with alternate vertical stripes of dark blue, light blue and white but lacking any complete circular markings as in juvenile Emperor Angelfish, Pomacanthus imperator. Fish of this family can produce a low frequency drum-like or thumping sound loud enough to startle divers. Feed on algae, sponges and tunicates, adults difficult to approach. Grows to 40 cm.
R. Stuart-Smith, G. Edgar, A. Green, I. Shaw, Tropical Marine Fishes of Australia. Reed New Holland Publishers, 2015. p.228.
Atlas of Living Australia website at https://bie.ala.org.au/search?q=Pomacanthus+semicirculatus. Accessed 02/07/18.
FishBase. Froese, R. and D. Pauly. Editors. 2018. World Wide Web electronic publication. https://fishbase.ca/summary/Pomacanthus-semicirculatus.html. Accessed 02/07/18.