Steephead Parrotfish, Chlorurus microrhinos (Bleeker 1854)

Other Names: Blunt-head Parrotfish, Gibbus Parrotfish, Heavybeak Parrotfish, Pacific Steephead Parrotfish

A male Steephead Parrotfish, Chlorurus microrhinos, in the Abrolhos Islands, Western Australia. Source: Rick Stuart-Smith / Reef Life Survey. License: CC by Attribution


This large parrotfish plays a very important role on coral reefs. As they graze schools of Steephead Parrotfish excavate coral to remove algae.

Footage of a Steephead Parrotfish sleeping in its protective mucus shield.

Cite this page as:
Dianne J. Bray, Chlorurus microrhinos in Fishes of Australia, accessed 28 Jan 2020,

Steephead Parrotfish, Chlorurus microrhinos (Bleeker 1854)

More Info


Rottnest Island to northern Western Australia including offshore reefs, Ashmore Reef, Timor Sea, and the northern Great Barrier Reef to Sydney, New South Wales; also Christmas Island in the eastern Indian Ocean, reefs in the Coral Sea, and the Lord Howe Island region in the Tasman Sea. Elsewhere the species is widespread in the east-Indo-west-central Pacific. Occurs in habitats ranging from inshore reefs to exposed outer reefs, forming schools of up to 40 individuals on reef fronts and reef crests.
This species is the most abundant large parrotfish in the Great Barrier Reef Marine Park and in Western Australian marine parks.


Herbivore - feeds on algae obtained by crunching coral from the reef.


A fast growing species, attaining a maximum age of 15 years.


This large parrotfish is targeted for food in much of its range, and is heavily fished in some areas.


In a recent study of steephead parrotfish on the Great Barrier Reef, tagged individuals had their internal temperatures monitored for a 24 h period using active acoustic telemetry. At night, on the reef, C. microrhinos were found to maintain a consistent average peritoneal cavity temperature 0.16 +/- 0.005°C (SE) warmer than the ambient temperature of the surrounding water (Welsh et al. 2012).


Dianne J. Bray

Steephead Parrotfish, Chlorurus microrhinos (Bleeker 1854)


Choat, J.H., Axe, L.M. & Lou, D.C. 1996. Growth and longevity in fishes of the family Scaridae. Marine Ecology Progress Series 145: 33-41 (as Chlorurus gibbus)

Choat, J.H., Carpenter, K.E., Clements, K.D., Rocha, L.A., Russell, B., Myers, R., Lazuardi, M.E., Muljadi, A., Pardede, S. & Rahardjo, P. 2012. Chlorurus microrhinos. The IUCN Red List of Threatened Species 2012: e.T190728A17783512. Downloaded on 02 August 2016.

Choat, J.H. & Randall, J.E. 1986. A review of the parrotfishes (family Scaridae) of the Great Barrier Reef of Australia with description of a new species. Records of the Australian Museum 38: 175-228.

Comeros-Raynal, M.T., Choat, J.H., Polidoro, B.A., Clements, K.D., Abesamis, R., Craig, M.T., Lazuardi, M.E., McIlwain, J., Muljadi, A., Myers, R.F., Nañola Jr., C.L., Pardede, S., Rocha, L.A., Russell, B., Sanciangco, J.C., Stockwell, B., Harwell, H. & Carpenter, K.E. 2012. The likelihood of extinction of iconic and dominant components of coral reefs: the parrotfishes and surgeonfishes. PLoS ONE

Russ, G. 1984. Distribution and abundance of herbivorous grazing fishes in the central Great Barrier Reef. I. Levels of variability across the entire continental shelf. Marine Ecology Progress Series 20: 23-34.

Smith, L.L., Fessler, J.L., Alfaro, M.E., Streelman, J.T. & Westneat, M.W. 2008. Phylogenetic relationships and the evolution of regulatory gene sequences in the parrotfishes. Molecular Phylogenetics and Evolution 49: 136-152. 

Welsh JQ, Bellwood DR (2012) Regional endothermy in a coral reef fish? PLoS ONE 7(3): e33187. doi:10.1371/journal.pone.0033187 pdf

Westneat, M.W. & Alfaro, M.E. 2005. Phylogenetic relationships and evolutionary history of the reef fish family Labridae. Molecular Phylogenetics and Evolution 36: 370–390.

Quick Facts

CAAB Code:37386020

Biology:Able to change sex

Conservation:IUCN Least Concern

Depth:1-50 m

Habitat:Reef associated

Max Size:80 cm TL

Species Maps

CAAB distribution map