Acanthurus tennentii 


Taxonomy [top]

Kingdom Phylum Class Order Family
Animalia Chordata Actinopterygii Perciformes Acanthuridae

Scientific Name: Acanthurus tennentii
Species Authority: Günther, 1861
Common Name(s):
English Doubleband Surgeonfish, Lieutenant Surgeonfish
French Chirurgien Fer à Cheval
Spanish Sangrador Herradura
Acanthurus bicommatus Smith, 1955
Acanthurus plagiatus Peters, 1876
Acanthurus tennenti Günther, 1861
Taxonomic Notes: Acanthurus tennentii hybridizes with A. olivaceus in Bali, Indonesia (Randall 2001a).

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., Abesamis, R., Clements, K.D., McIlwain, J., Myers, R., Nanola, C., Rocha, L.A. & Stockwell, B.
Reviewer(s): McClenachan, L., Edgar, G. & Kulbicki, M.
Acanthurus tennentii is widely distributed and although utilized for food and aquarium trade, these uses appear to be minor. Its distribution overlaps with a number of marine reserves in parts of its range. It is therefore listed as Least Concern. We recommend monitoring of the harvest levels and population trends of this species.

Geographic Range [top]

Range Description:Acanthurus tennentii is found from East Africa to the west coast of Thailand and along southern Indonesia as far east as Bali including Christmas and Cocos-Keeling. It is not known from the Red Sea (Randall 2001a).
Countries occurrence:
British Indian Ocean Territory; Christmas Island; Cocos (Keeling) Islands; Comoros; Djibouti; French Southern Territories (Mozambique Channel Is.); India (Andaman Is., Nicobar Is.); Indonesia; Kenya; Madagascar; Malaysia; Maldives; Mauritius; Mayotte; Mozambique; Myanmar; Oman; Réunion; Seychelles; South Africa; Sri Lanka; Tanzania, United Republic of; Thailand; Yemen
FAO Marine Fishing Areas:
Indian Ocean – western; Indian Ocean – eastern; Pacific – western central
Lower depth limit (metres):35
Upper depth limit (metres):1
Range Map:Click here to open the map viewer and explore range.

Population [top]

Population:Acanthurus tennentii is common in the Seychelles, Maldives and Mauritius and rare in Oman, where it was observed only in the south (Randall 1995). It is common but not abundant throughout its range (L. Rocha pers. comm. 2010). It is rare on the reef flats of Reunion (Letourner et al. 1993).

In Kenya, landings during 1978-2001 for families that are less important in commercial catches (e.g., scarinae and Acanthuridae) showed rising catches (1978-1984) followed by a general decline during the 1990s (Kaunda-Arara et al. 2003).
Current Population Trend:Stable
Additional data:
Population severely fragmented:No

Habitat and Ecology [top]

Habitat and Ecology:Acanthurus tennentii inhabits shallow-water coral reefs. It is classified as a grazer/detritivore (Choat and Bellwood pers. obs. in Green and Bellwood 2009). 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 tennentii is captured for food in nets and traps. It is also a minor component of the aquarium fishery. Online prices range from $45.99-$89.99 per fish (L. Rocha pers. comm. 2010).

Threats [top]

Major Threat(s): There are indications of localized population declines from fishing in Kenya.

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 -> 9.2. Marine Neritic - Subtidal Rock and Rocky Reefs
suitability: Suitable  
9. Marine Neritic -> 9.3. Marine Neritic - Subtidal Loose Rock/pebble/gravel
suitability: Suitable  
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 -> 9.8.2. Back Slope
suitability: Suitable  
9. Marine Neritic -> 9.8. Marine Neritic - Coral Reef -> 9.8.3. Foreslope (Outer Reef Slope)
suitability: Suitable  
9. Marine Neritic -> 9.8. Marine Neritic - Coral Reef -> 9.8.6. Inter-Reef Rubble Substrate
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
5. Biological resource use -> 5.4. Fishing & harvesting aquatic resources -> 5.4.1. Intentional use: (subsistence/small scale)
♦ timing: Ongoing ♦ scope: Unknown ♦ severity: Unknown ⇒ Impact score: Unknown 
→ Stresses
  • 2. Species Stresses -> 2.1. Species mortality

1. Research -> 1.2. Population size, distribution & trends
1. Research -> 1.3. Life history & ecology
3. Monitoring -> 3.1. Population trends
3. Monitoring -> 3.2. Harvest level trends

♦  Food - human
 Local : ✓ 

♦  Pets/display animals, horticulture
 International : ✓ 

Bibliography [top]

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

Green, A.L. and Bellwood, D.R. 2009. Monitoring functional groups of herbivorous reef fishes as indicators of coral reef resilience – A practical guide for coral reef managers in the Asia Pacific region. IUCN, Gland, Switzerland.

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

Kaunda-Arara, B., Rose, G.A., Muchiri, M.S. and Kaka, R. 2003. Long-term Trends in Coral Reef Fish Yields and Exploitation Rates of Commercial Species from Coastal Kenya. Western Indian Ocean Journal of Marine Science 2(2): 105-116.

Randall, J.E. 1995. Coastal fishes of Oman. University of Hawaii Press, Honolulu, Hawaii.

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., Abesamis, R., Clements, K.D., McIlwain, J., Myers, R., Nanola, C., Rocha, L.A. & Stockwell, B. 2012. Acanthurus tennentii. In: The IUCN Red List of Threatened Species 2012: e.T177997A1516035. . Downloaded on 28 November 2015.
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