Details
Acanthurus leucosternon
The powder blue tang is a vivid surgeonfish of Indian Ocean reefs. Its blue body and yellow dorsal fin stand out as it grazes algae.
Map: Ecoregions 2017 © RESOLVE (CC BY 4.0) · Natural Earth (PD)
It uses outer reef slopes, wave-washed reef edges, and shallow lagoon reefs in the Indian Ocean. Hard surfaces with algal growth and open swimming space are favored.
Length is 19-25 cm and weight 300-600 g. The body is powdery blue, the dorsal fin yellow, the face black, and the chest white; a sharp spine sits on the tail base.
Diurnal fish feed in loose groups or small aggregations. Some individuals are territorial and may present the tail spine during disputes.
A herbivore, it grazes mainly filamentous algae from rocks and reef surfaces. By cropping algae, it can help keep coral surfaces from being overgrown.
During spawning, adults rise into the water column and release eggs and sperm. Eggs and larvae drift before young fish join reef habitats.
It is listed as Least Concern. Popular in the aquarium trade, it depends on healthy reefs with algal grazing surfaces.
