Acanthurus olivaceus (Bloch and Schneider, 1801)

Common Name: 
Orangeblotch Surgeonfish

Uncommon as adults in the Solitary Islands Marine Park. Widespread Indo-Pacific, Christmas Island and Cocos-Keeling Islands in the eastern Indian Ocean to Hawaii in the Pacific Ocean, north to Japan, south to Lord Howe Island. In Australia north from Exmouth in Western Australia and from the northern Great Barrier Reef in Queensland south to northern New South Wales.

Ecological Notes: 

Frequents shallow rocky and coral reef areas, benthic feeder grazing on fine filamentous alga on rocks and sand. Juveniles in more protected bays or lagoons. Depth range from 3 to at least 46m.

Additional Notes: 

Juveniles, pictured in top and centre photographs, usually in small aggregations, often with other surgeonfish juveniles. Adult in lower photograph with large black-edged orange blotch just behind and below eye. Colouration may vary, head and anterior half of body usually abruptly paler than posterior half of body. Adults singly or in small groups, feed on fine filamentous algae growing on rocks and sand. A tropical species preferring water temperature above 24C degrees. Grows to 35cm.


R. Stuart-Smith, G. Edgar, A. Green, I. Shaw, Tropical Marine Fishes of Australia. Reed New Holland Publishers, 2015. p.427.

FishBase. Froese, R. and D. Pauly. Editors. 2018. World Wide Web electronic publication. Accessed 11/04/18.