Acanthurus nubilus 


Taxonomy [top]

Kingdom Phylum Class Order Family
Animalia Chordata Actinopterygii Perciformes Acanthuridae

Scientific Name: Acanthurus nubilus
Species Authority: (Fowler & Bean, 1929)
Common Name(s):
English Dropoff Surgeonfish, Pin-striped Surgeon, Bluelined Surgeonfish
French Chirurgien Rond
Harpurina nubilus (Fowler & Bean, 1929)
Hepatus nubilus Fowler & Bean, 1929

Assessment Information [top]

Red List Category & Criteria: Least Concern ver 3.1
Year Published: 2012
Date Assessed: 2010-05-04
Assessor(s): Russell, B., Choat, J.H., Myers, R., Abesamis, R., Clements, K.D., McIlwain, J., Nanola, C., Rocha, L.A. & Stockwell, B.
Reviewer(s): Davidson, L., Edgar, G. & Kulbicki, M.
Acanthurus nubilus is widely distributed and occurs in moderately deep water (25 to at least 90 m). It is a rare species that occurs in steep, current-swept drop-offs. Utilization is minor and there are no apparent major threats. It occurs in a number of marine reserves in parts of its range. It is therefore listed as Least Concern.

Geographic Range [top]

Range Description:Acanthurus nubilus is found from Indonesia, Society Islands and New Caledonia. It is also reported from the Austral Islands, Pitcairn, Philippines, and the Marianas (Lieske and Myers 1994).
Countries occurrence:
French Polynesia; Guam; Indonesia; Kiribati (Phoenix Is.); New Caledonia; Northern Mariana Islands; Papua New Guinea; Philippines; Pitcairn; Solomon Islands; Timor-Leste; United States Minor Outlying Islands (Wake Is.)
FAO Marine Fishing Areas:
Indian Ocean – eastern; Pacific – eastern central; Pacific – northwest; Pacific – southwest; Pacific – western central
Lower depth limit (metres):90
Upper depth limit (metres):25
Range Map:Click here to open the map viewer and explore range.

Population [top]

Population:Acanthurus nubilus was recorded as rare in Milne Bay Province, Papua New Guinea and in Raja Ampat, Indonesia, where only 2 were seen on outer drop-offs (Allen 2003, 2003b). There were 1-2 individuals recorded in steep walls in Balicasag Island, Philippines (B. Stockwell pers. comm. 2010). There were loose aggregations observed in Wakatobi, Indonesia (R. Myers pers. comm. 2010).
Current Population Trend:Unknown
Additional data:
Population severely fragmented:No

Habitat and Ecology [top]

Habitat and Ecology:Acanthurus nubilus is typically found on steep drop-offs feeding on zooplankton well away from the substratum at depths of 25 to at least 90 m. It is a rare species that occurs in steep, current-swept drop-offs (Lieske and Myers 1994, Kuiter and Tonozuka 2001). It is usually seen well off the bottom (Randall 1956). It is a planktivore (Myers 1999). The sexes are separate among the acanthurids (Reeson 1983). Acanthurids do not display obvious sexual dimorphism, males assume courtship colours (J.H. Choat pers. comm. 2010).

Use and Trade [top]

Use and Trade: Acanthurus nubilus is collected for food and is a minor component of the aquarium fishery.

Threats [top]

Major Threat(s): There are no major threats known for this species.

Surgeonfishes show varying degrees of habitat preference and utilization of coral reef habitats, with some species spending the majority of their life stages on coral reef while others primarily utilize seagrass beds, mangroves, algal beds, and /or rocky reefs. The majority of surgeonfishes are exclusively found on coral reef habitat, and of these, approximately 80% are experiencing a greater than 30% loss of coral reef area and degradation of coral reef habitat quality across their distributions. However, more research is needed to understand the long-term effects of coral reef habitat loss and degradation on these species' populations. Widespread coral reef loss and declining habitat conditions are particularly worrying for species that recruit into areas with live coral cover, especially as studies have shown that protection of pristine habitats facilitate the persistence of adult populations in species that have spatially separated adult and juvenile habitats (Comeros-Raynal et al. 2012).

Conservation Actions [top]

Conservation Actions: There are no species-specific conservation measures in place for this species. However, its distribution overlaps several marine protected areas within its range.

Classifications [top]

9. Marine Neritic -> 9.8. Marine Neritic - Coral Reef -> 9.8.1. Outer Reef Channel
suitability: Suitable  
9. Marine Neritic -> 9.8. Marine Neritic - Coral Reef -> 9.8.3. Foreslope (Outer Reef Slope)
suitability: Suitable  

In-Place Research, Monitoring and Planning
In-Place Land/Water Protection and Management
  Conservation sites identified:Yes, over part of range
  Occur in at least one PA:Yes
In-Place Species Management
In-Place Education
1. Research -> 1.2. Population size, distribution & trends
3. Monitoring -> 3.1. Population trends

♦  Food - human
 Local : ✓ 

♦  Pets/display animals, horticulture
 International : ✓ 

Bibliography [top]

Allen, G.R. 2003. Appendix 5. List of the reef fishes of Milne Bay Province, Papua New Guinea. In: G.R. Allen, J. P. Kinch, S.A. McKenna, and P. Seeto (eds), A Rapid Marine Biodiversity Assessment of Milne Bay Province, Papua New Guinea–Survey II (2000), pp. 172. Conservation International, Washington, DC, USA.

Allen, G.R. 2003b. Appendix 1. List of the Reef Fishes of the Raja Ampat Islands. In: R. Donnelly, D. Neville and P.J. Mous (eds), Report on a rapid ecological assessment of the Raja Ampat Islands, Papua, Eastern Indonesia, held October 30 – November 22, 2002. The Nature Conservancy - Southeast Asia Center for Marine Protected Areas, Sanur, Bali.

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. and Carpenter, K.E. 2012. The likelihood of extinction of iconic and dominant components of coral reefs: the parrotfishes and surgeonfishes. PLoS ONE

IUCN. 2012. IUCN Red List of Threatened Species (ver. 2012.2). Available at: (Accessed: 17 October 2012).

Kuiter, R.H. and Tonozuka, T. 2001. Pictorial guide to Indonesian reef fishes. Part 3. Jawfishes - Sunfishes, Opistognathidae - Molidae. Zoonetics, Australia.

Lieske, E. and Myers, R.F. 1994. Collins Pocket Guide. Coral reef fishes. Indo-Pacific and Caribbean including the Red Sea. Harper Collins Publishers, New York, USA.

Myers, R.F. 1999. Micronesian reef fishes: a comprehensive guide to the coral reef fishes of Micronesia. Coral Graphics, Barrigada, Guam.

Randall, J.E. 1956. A revision of the surgeonfish genus Acanthurus. Pacific Science 10(2): 159-235.

Randall, J.E. 2001a. Surgeonfishes of the world. Mutual Publishing and Bishop Museum Press, Hawai'i, Honolulu, Hawaii.

Reeson, P.H. 1983. The biology, ecology and bionomics of the surgeonfishes, Acanthuridae. In: J.L. Munro (ed.), Caribbean coral reef fishery resources, pp. 178-190.

Citation: Russell, B., Choat, J.H., Myers, R., Abesamis, R., Clements, K.D., McIlwain, J., Nanola, C., Rocha, L.A. & Stockwell, B. 2012. Acanthurus nubilus. In: The IUCN Red List of Threatened Species 2012: e.T177961A1503615. . Downloaded on 30 November 2015.
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