Dusky Surgeonfish, Acanthurus nigrofuscus (Forsskål 1775)

Other Names: Blackspot Surgeonfish, Brown Surgeonfish, Brown Tang, Dusky Surgeon, Lavender Tang, Spot-cheeked Surgeonfish

A Dusky Surgeonfish, Acanthurus nigrofuscus, at Lord Howe Island in the Tasman Sea, February 2016. Source: John Turnbull / Flickr. License: CC by Attribution-NonCommercial-ShareAlike

A brown to purplish or bluish-brown surgeonfish with small orange spots on the head and chest, a black spot at the rear of the dorsal and anal fin bases, a narrow pale blue margin on the dorsal and anal fins, a black margin around the caudal peduncle blade, and a slightly concave head profile.
Video of a mass spawning of Dusky Surgeonfish(aka Brown Surgeonfish) on the Far Northern Section of the Great Barrier Reef, Queensland.

Cite this page as:
Acanthurus nigrofuscus in Fishes of Australia, accessed 17 Jul 2024, https://fishesofaustralia.net.au/home/species/2189

Dusky Surgeonfish, Acanthurus nigrofuscus (Forsskål 1775)

More Info


Widespread in Australia from Rottnest Island to the Dampier Archipelago, and offshore reefs of Western Australia, Ashmore Reef, Timor Sea, and the far northern Great Barrier Reef, Queensland, and reefs in the Coral Sea, to Jervis Bay, New South Wales, with juveniles further south. Also at Cocos (Keeling) Islands and Christmas Island in the eastern Indian Ocean, the Lord Howe Islandregion and Norfolk Island in the Tasman Sea. Elsewhere the species is widespread in the Indo-west-central Pacific.
A common and abundant surgeonfish on reefs throughout most of its distribution range.
Small groups of this relatively small, aggressive surgeonfish inhabit sheltered coral and rocky reefs, often around bommies - in depths from the surge zone to about 25m. May form large schools in some oceanic areas.


Dorsal fin IX, 24-27; Anal fin III, 22-24; Gill rakers on first arch: anterior row 20-24, posterior row 18-23. 


With or without fine bluish gray longitudinal lines on body; pale pectoral fins with upper edge narrowly black; pelvic fins brown. Lips blackish brown; median upper teeth tend to be pointed. Dorsal fin base with a prominent black spot larger than 1/2 eye diameter; a smaller spot on base of anal fin. Groove of caudal spine encircled with a narrow black margin. 


Dusky Surgeonfish feed mostly on algae, using their teeth to crop reef-grown algal turfs (Tebbett et al. 2017).

Similar Species

The similar Lined Bristletooth, Ctenochaetus striatus, lacks spots at the rear of the dorsal and anal fins.

Species Citation

Chaetodon nigrofuscus Forsskål 1775, Descriptiones Animalium: xiii, 64. Type locality: Djedda, Red Sea.


Australian Faunal Directory

Dusky Surgeonfish, Acanthurus nigrofuscus (Forsskål 1775)


Allen, G.R. 1993. Fishes of Ashmore Reef and Cartier Island. Records of the Western Australian Museum, Supplement 44: 67-91 

Allen, G.R. 1997. Marine Fishes of Tropical Australia and South-east Asia. Perth : Western Australian Museum 292 pp. 106 pls. Allen, G.R. & Erdmann, M.V. 2012. Reef fishes of the East Indies. Perth : Tropical Reef Research 3 vols, 1260 pp.

Allen, G.R. & Russell, B.C. 1986. Part VII Fishes. pp. 79-103 in Berry, P.F. (ed.). Faunal Surveys of the Rowley Shoals, Scott Reef and Seringapatam Reef, northwestern Australia. Records of the Western Australian Museum, Supplement 25: 1-106 

Allen, G.R. & Smith-Vaniz, W.F. 1994. Fishes of Cocos (Keeling) Islands. Atoll Research Bulletin 412: 1-21 

Allen, G.R., Steene, R.C. & Orchard, M. 2007. Fishes of Christmas Island. Christmas Island : Christmas Island Natural History Association 2 edn, 284 pp.  

Allen, G.R. & Swainston, R. 1988. The Marine Fishes of North-Western Australia. A field guide for anglers and divers. Perth, WA : Western Australian Museum vi 201 pp., 70 pls. 

Angert, E., Clements, K.D. & Pace, N.R. 1993. The largest bacterium, Nature 362: 239-241.

Bellwood, D.R. & Fulton, C.J. 2008. Sediment-mediated suppression of herbivory on coral reefs: decreasing resilience to rising sea levels and climate change? Limnology and Oceanography 53: 2695-2701.

Choat, J.H., McIlwain, J., Abesamis, R., Clements, K.D., Myers, R., Nanola, C., Rocha, L.A., Russell, B. & Stockwell, B. 2012. Acanthurus nigrofuscus. The IUCN Red List of Threatened Species 2012: e.T178019A1523035. http://dx.doi.org/10.2305/IUCN.UK.2012.RLTS.T178019A1523035.en. Downloaded on 25 January 2018.

Choat, J.H., Robbins, W.D. & Clements, K.D. 2004. The trophic status of herbivorous fishes on coral reefs. Marine Biology 145: 445-454.

Fishelson, L., Montgomery, L.W. &  Myrberg, A.H. Jr., 1987. Biology of surgeonfish Acanthurus nigrofuscus with emphasis on changeover in diet and annual gonadal cycles. Marine Ecology Progress Series 39: 37-47.

Forsskål, P. 1775. Descriptiones Animalium Avium, Amphibiorum, Piscium, Insectorum, Vermium; quæ in Itinere Orientali observavit Petrus Forskål. Post Mortem Auctoris edidit Carsten Niebuhr. Adjuncta est Materia Medica Kakirina atque Tabula Maris Rubri Geographica. Hauniæ : Mölleri 1-19, i-xxxiv, 164 pp., 1 map. 

Francis, M. 1993. Checklist of the coastal fishes of Lord Howe, Norfolk, and Kermadec Islands, southwest Pacific Ocean. Pacific Science 47(2): 136-170 figs 1-2 

Hutchins, J.B. 2001. Biodiversity of shallow reef fish assemblages in Western Australia using a rapid censusing technique. Records of the Western Australian Museum 20: 247-270 

Hutchins, J.B. 2003. Checklist of marine fishes of the Dampier Archipelago, Western Australia. pp. 453-478 in Wells, F.E., Walker, D.I., & Jones, D.S. (eds). Proceedings of the Eleventh International Marine Biological Workshop: The Marine Flora and Fauna of Dampier, Western Australia. Perth : Western Australian Museum. 

Hutchins, J.B. & Swainston, R. 1986. Sea Fishes of Southern Australia. Complete field guide for anglers and divers. Perth : Swainston Publishing 180 pp. 

Johnson, J.W. 1999. Annotated checklist of the fishes of Moreton Bay, Queensland, Australia. Memoirs of the Queensland Museum 43(2): 709-762.

Johnson, J.W. 2010. Fishes of the Moreton Bay Marine Park and adjacent continental shelf waters, Queensland, Australia. pp. 299-353 in Davie, P.J.F. & Phillips, J.A. Proceedings of the Thirteenth International Marine Biological Workshop, The Marine Fauna and Flora of Moreton Bay. Memoirs of the Queensland Museum 54(3) 

Kuiter, R.H. 1992. Tropical reef-fishes of the western Pacific Indonesia and adjacent waters. Gramedia Pustaka Utama, Jakarta. 314 pp.

Kuiter, R.H. 1993. Coastal Fishes of South-eastern Australia. Bathurst : Crawford House Press 437 pp. 

Kuiter, R.H. & Debelius, H. 2001. Surgeonfishes, Rabbitfishes and Their Relatives. A comprehensive guide to Acanthuroidei. Chorleywood, U.K. : TMC Publishing 208 pp. 

Oxley, W.G., Ayling, A.M., Cheal, A.J. & Osborne, K. 2004. Marine surveys undertaken in the Elizabeth and Middleton Reefs Marine National Nature Reserve, December 2003. Townsville : Australian Institute of Marine Sciences 64 pp. 

Oxley, W.G., Ayling, A.M., Cheal, A.J. & Thompson, A.A. 2003. Marine surveys undertaken in the Coringa-Herald National Nature Reserve, March-April 2003. Townsville : Australian Institute of Marine Science 59 pp. 

Oxley, W.G., Emslie, M., Muir, P. & Thompson, A.A. 2004. Marine surveys undertaken in the Lihou Reef National Nature Reserve, March 2004. Townsville : Australian Institute of Marine Science i-vii, 1-67 pp. 

Purcell, S.W. & Bellwood, D.R. 1993. A functional analysis of food procurement in two surgeonfish species, Acanthurus nigrofuscus and Ctenochaetus striatus (Acanthuridae), Environmental Biology of Fishes 37: 139-159.

Randall, J.E. 1956. A revision of the surgeon fish genus Acanthurus. Pacific Science 10(2): 159-235 figs 1-23 pls 1-3 

Randall, J.E. 2001. Surgeonfishes of Hawai'i and the World. Honolulu : Mutual Publishing and Bishop Museum Press 125 pp. 

Randall, J.E. 2001. Zanclidae, Acanthuridae. pp. 3651-3683 in Carpenter, K.E. & Niem, T.H. (eds). The Living Marine Resources of the Western Central Pacific. FAO Species Identification Guide for Fisheries Purposes. Rome : FAO Vol. 6 pp. 3381-4218. 

Randall, J.E., Allen, G.R. & Steene, R. 1990. Fishes of the Great Barrier Reef and Coral Sea. Bathurst : Crawford House Press 507 pp. figs.

Randall, J.E., Allen, G.R. & Steene, R. 1997. Fishes of the Great Barrier Reef and Coral Sea. Bathurst : Crawford House Press 557 pp. figs.

Robertson, D.R. 1983. On the spawning behavior and spawning cycles of eight surgeonfishes (Acanthuridae) from the Indo-Pacific. Environmental Biology of Fishes 9(3/4): 193-223. 

Russell, B.C. 1983. Annotated checklist of the coral reef fishes in the Capricorn-Bunker group, Great Barrier Reef, Australia. Great Barrier Reef Marine Park Authority. Special Publication Series 1: 1-184 figs 1-2 

Russell, B.C., Larson, H.K., Hutchins, J.B. & Allen, G.R. 2005. Reef fishes of the Sahul Shelf. The Beagle, Records of the Museums and Art Galleries of the Northern Territory Supplement 1 2005: 83-105 

Tebbett, S.B., Goatley, C.H.R. & Bellwood, D.R. 2017. The effects of algal turf sediments and organic loads on feeding by coral reef surgeonfishes., PLOS One, doi:10.1371/journal.pone.0169479. 

Tebbett, S.B., Goatley, C.H.R. & Bellwood, D.R. 2017. Clarifying functional roles: algal removal by the surgeonfishes Ctenochaetus striatus and Acanthurus nigrofuscusCoral Reefs doi:10.1007/s00338-017-1571-z Abstract

Quick Facts

CAAB Code:37437014

Danger:IUCN Least Concern

Depth:1-25 m

Habitat:Aquarium fish

Max Size:21 cm TL

Max Size:Reef associated

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