Species Details

Details of Blackstreak Surgeonfish will be displayed below

Blackstreak Surgeo...   

Common Name: Blackstreak Surgeonfish
Scientific Name: Acanthurus nigricauda
Local Name: Andhun kaalhu
Dhivehi Name: އަނދުންކާޅު
Animalia  (Kingdom)
Chordata  (Plylum)
Perciformes  (Order)
Acanthuridae  (Family)
Acanthurus   (Genus)

Blackstreak Surgeonfish's description

Dorsal spines (total): 9; Dorsal soft rays (total): 25-28; Anal spines: 3; Anal soft rays: 23 - 26. Color in life dark brown without lines on body or spots on head (one phase is purplish grey); horizontal black band behind upper gill opening absent on juveniles <6 cm SL; elongate purple band may be present anterior to dorsal origin; caudal fin brown; outer third of pectoral fin pale. Species with gizzard-like stomach.

Blackstreak Surgeonfish's facts

Did you know?

  • Blackstreak Surgeonfish is poisonous to eat.

Blackstreak Surgeonfish's Behavior & Ecology

Occurs in clear lagoon and seaward reefs around isolated coral heads. Solitary or in small groups. Prefers sandy bottoms of bays and lagoons rather than the coral reefs like most other Acanthuridae.

Blackstreak Surgeonfish's Relationship with Humans

Blackstreak Surgeonfish is harvested as food (in some parts of the world) and is a component of the aquarium trade. Harvest is not considered a major threat globally and it occurs in a number of marine reserves in parts of its distribution.

Blackstreak Surgeonfish habitat

Acanthurus nigricauda occurs in sandy areas near coral reefs or rocky bottom where it grazes on the biofilm on sandy surfaces. It has low levels of SCFAs (short chain fatty acids) (Clements and Choat 1995). Its diet is dominated by organic detritus and calcareous sediments with very small portions of identifiable algae (Choat et al. 2002b).


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.).

Blackstreak Surgeonfish threats

Acanthurus nigricauda may be affected by targeted fishing in some parts of its range.

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).

Blackstreak Surgeonfish's status