|Scientific Name:||Acanthurus olivaceus|
|Species Authority:||Bloch & Schneider, 1801|
Acanthurus chrysosoma Bleeker, 1857
Acanthurus eparei Lesson, 1830
Acanthurus humeralis Valenciennes, 1835
Ctenodon erythromelas Swainson, 1839
Harpurus paroticus Forster, 1844
Hepatus chrysosoma (Bleeker, 1857)
Hepatus olivaceus (Bloch & Schneider, 1801)
Rhombotides olivaceus (Bloch & Schneider, 1801)
Rhombotides xanthosoma Bleeker, 1865
Teuthis olivaceus (Bloch & Schneider, 1801)
|Taxonomic Notes:||This species hybridizes with Acanthurus nigricauda in the Marshall Is. and A. tennentii in Bali (Randall 2001a).|
|Red List Category & Criteria:||Least Concern ver 3.1|
|Assessor(s):||Russell, B., McIlwain, J., Choat, J.H., Abesamis, R., Clements, K.D., Myers, R., Nanola, C., Rocha, L.A. & Stockwell, B.|
|Reviewer(s):||Davidson, L., Edgar, G. & Kulbicki, M.|
Acanthurus olivaceus is widely distributed and is moderately common. It is a minor component of the aquarium trade and is landed in fish markets. There are no apparent major threats and its distribution overlaps with several marine protected areas. It is therefore listed as Least Concern.
|Range Description:||Acanthurus olivaceus is found from southern Japan to northern New South Wales, Australia, eastwards to the Hawaiian Islands and Tuamotu Archipelago. In the Indian Ocean, it is found from Christmas Island (Allen and Swainston, 1988), Cocos-Keeling Islands (Allen and Smith-Vaniz 1994), Western Australia to Ningaloo Reef (Allen and Swainston 1988).|
Native:American Samoa (American Samoa); Australia; Brunei Darussalam; China; Christmas Island; Cocos (Keeling) Islands; Cook Islands; Disputed Territory (Paracel Is., Spratly Is.); Fiji; French Polynesia; Guam; Hong Kong; Indonesia; Japan; Kiribati (Gilbert Is., Kiribati Line Is., Phoenix Is.); Macao; Malaysia; Marshall Islands; Micronesia, Federated States of ; Nauru; New Caledonia; Niue; Northern Mariana Islands; Palau; Papua New Guinea; Philippines; Samoa; Singapore; Solomon Islands; Taiwan, Province of China; Timor-Leste; Tokelau; Tonga; Tuvalu; United States (Hawaiian Is.); United States Minor Outlying Islands (Howland-Baker Is., Johnston I., Midway Is., US Line Is.); Vanuatu; Viet Nam; Wallis and Futuna
|FAO Marine Fishing Areas:||
Indian Ocean – eastern; Pacific – eastern central; Pacific – northwest; Pacific – southwest; Pacific – western central
|Range Map:||Click here to open the map viewer and explore range.|
Acanthurus olivaceus is common in most of its range (G. Allen pers. comm.). It was recorded as occasional in terms of relative abundance in Milne Bay Province and northern Bismarck Sea, Papua New Guinea (Allen 2003, 2009). It is moderately common on mixed sand reef at Raja Ampat, Indonesia (Allen 2003b). It is common in the American Samoa National Park (National Park of Samoa Checklist of Fishes accessed 21 April 2010). It is rare in Calamianes Islands and Puerto Princesa City, Philippines (Werner and Allen 2000, Palawan Council for Sustainable Development unpub. data). It is common and abundant in the Spratly Islands and Tubbataha, Philippines (S. Conales, Jr. pers. comm. 2010).
At Moorea, French Polynesia, SPOT satellite images allowed estimation of the surface area of fringing reef (1,076 ha), barrier reef (3,788 ha) and outer slope (493 ha). A total of 23,132 individuals were recorded in this area in fish visual surveys conducted from 1990-1993 (Lecchini et al. 2006). The Acanthuridae family was dominant on the barrier reef (2.30 ind. m-2) and on the outer slope, (1.61 spec. m-2). On the outer slope, this species accounted for 7.5% of the total density (Moussa 2009).
It is moderately common in Guam and Saipan particularly on exposed coasts. It comprises 3% of the total Acanthurid density in both Guam and Saipan (J. McIlwain unpub. data). 3,000 kg were landed in Hawaii each year in commercial landings (Hawaii Division of Aquatic Resources unpub. data). In Guam it comprises 5%, and Saipan 2%, of the Acanthurid fishery (Guam Division of Aquatic and Wildlfe Resources and P. Houk unpub. data). It is a minor component of the fishery in Pohnpei (Rhodes et al. 2008).
This species is one of the eight most collected aquarium fish in West Hawaii. The total number of individuals caught from FY 2005-2009 was 5,195 with a total value of $9, 654. There was a non-significant decrease in overall density across Fish Replenishment Areas (FRAs) surveyed from 1999-2009. However, the FRAs were shown to be effective in terms of increases inside the FRAs relative to long term marine protected areas (Walsh et al. 2010).
|Habitat and Ecology:||
Acanthurus olivaceus is usually encountered grazing over sand near reefs, sometimes in small aggregations (Randall 2001a), submarine observations to 62 m (Chave and Mundy 1994). It occurs over coral and rubble bottoms (Brown and Allen 2008). It is found in depths from 9 to at least 46 m depth, juveniles inhabit protected bays and lagoons, singly or in small groups in as little as 3 m. Adults occur singly or in schools. Its diet is dominated by organic detritus and calcareous sediments with very small portions of identifiable algae (Choat et al. 2002).
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). This species was reported to form spawning aggregations on the Great Barrier Reef (Squire and Samoilys unpub. data). Size at sexual maturity 180 mm (Choat and Robertson 2002a).Growth
It shows rapid growth for the first three to four years of life. Beyond four years, growth declines sharply; resulting in extended periods of asymptotic growth. The maximum number of annuli recorded for this species was 32 to 35 (Choat and Axe 1996). Maximum age recorded was 33 years in the Great Barrier Reef (Choat and Robertson 2002a).
|Use and Trade:||Acanthurus olivaceus is occasionally seen in fish markets. Juveniles are sought after aquarium fish. Online prices range from $29.99-$69.99 (L. Rocha pers. comm. 2010).|
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:||There are no species-specific conservation measures in place for this species. However, its distribution overlaps several marine protected areas within its range.|
|Citation:||Russell, B., McIlwain, J., Choat, J.H., Abesamis, R., Clements, K.D., Myers, R., Nanola, C., Rocha, L.A. & Stockwell, B. 2012. Acanthurus olivaceus. The IUCN Red List of Threatened Species. Version 2014.2. <www.iucnredlist.org>. Downloaded on 01 October 2014.|