|Scientific Name:||Acanthurus tristis|
|Species Authority:||Randall, 1993|
|Taxonomic Notes:||Hybrids of Acanthurus trisis with A. pyroferus were observed in Bali, Indonesia (Randall 2001a).|
|Red List Category & Criteria:||Least Concern ver 3.1|
|Assessor/s:||Abesamis, R., Clements, K.D., Choat, J.H., McIlwain, J., Myers, R., Nanola, C., Rocha, L.A., Russell, B. & Stockwell, B.|
|Reviewer/s:||McClenachan, L., Edgar, G. & Kulbicki, M.|
Acanthurus tristis is found in the eastern Indian Ocean. It is rare in parts of its range and can be common but not abundant in parts of its distribution (Bali). Juveniles are a minor component of the aquarium trade in Sri Lanka and it is incidentally captured for food. Harvesting is not considered to be a threat at present time and its distribution overlaps with marine protected areas in parts of its range. It is therefore listed as Least Concern. We recommend monitoring of the harvest levels and population status of this species.
|Range Description:||Acanthurus tristis is found from the Andaman Sea, southern Indonesia to the Maldive Islands and Chagos Archipelago.|
Native:Bangladesh; British Indian Ocean Territory; Christmas Island; Cocos (Keeling) Islands; India (Andaman Is., Nicobar Is.); Indonesia; Malaysia (Peninsular Malaysia); Maldives; Myanmar; Sri Lanka; Thailand
|FAO Marine Fishing Areas:||
Indian Ocean – eastern; Indian Ocean – western; Pacific – western central
|Range Map:||Click here to open the map viewer and explore range.|
|Population:||Acanthurus tristis is rare in the Seychelles, Christmas and Cocos Islands (J.H. Choat pers. comm. 2010). It is common in Bali, Indonesia, but not abundant (L. Rocha pers. comm. 2010). This species is a target reef fish in western Thailand. One hundred and twenty-four individuals were recorded from 14 sites off the western coast of Thailand, four months after the Sumatran tsunami disaster (Allen 2005).|
|Habitat and Ecology:||
Acanthurus tristis occurs on shallow lagoon and seaward reefs, in areas of mixed coral, rock or sand. It generally occurs in deeper and more sheltered waters, frequently over sand and rubble bottoms (J.H. Choat pers. comm. 2010). It is classified as a detritivore (Choat and Beood 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). Juveniles of this species resemble Centropyge eibli (Kuiter and Debelius 1994).
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.|
Allen, M. 2005. A post-tsunami assessment of coral reef fin-fish resources on the Andaman Sea coast of Thailand. In: G.R. Allen and G.S. Stone (eds), Rapid Assessment Survey of Tsunami-affected Reefs of Thailand. Final Technical Report. November 15, 2005.
Comeros-Raynal, M.T., Choat, J.H., Polidoro, B., Clements, K.D., Abesamis, R., Craig, M.T., Lazuardi, M.E., McIlwain, J., Muljadi, A., Myers, R.F., et al.. 2012. The likelihood of extinction of iconic and dominant components of coral reefs: the parrotfishes and surgeonfishes. PLoS ONE http://dx.plos.org/10.1371/journal.pone.0039825.
DeBruin, G.H.P., Russell, B.C. and Bogusch, A. 1994. The Marine Fishery Resources of Sri Lanka. FAO, Rome (Italy).
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: http://www.iucnredlist.org. (Accessed: 17 October 2012).
Kuiter, R.H. and Debelius, H. 1994. Southeast Asia Tropical Fish Guide. IKAN-Unterwasserarchiv. Frankfurt, Germany. 321 p
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.
thatpetplace.com. 2010. Acanthurus tristis "Half black Mimic ang". Available at: http://www.thatpetplace.com/pet/group/6732/product.web. (Accessed: 13 April).
|Citation:||Abesamis, R., Clements, K.D., Choat, J.H., McIlwain, J., Myers, R., Nanola, C., Rocha, L.A., Russell, B. & Stockwell, B. 2012. Acanthurus tristis. In: IUCN 2013. IUCN Red List of Threatened Species. Version 2013.2. <www.iucnredlist.org>. Downloaded on 24 April 2014.|