Also known as Bullseye, Hatchet Fish, Sweeper Fish.
Found in schools during the day sheltering in caves, under ledges, harbours and in shipwrecks, dispersing at night to hunt for food over coral and rocky reefs.
They feed nocturnally on crustaceans and worms.
Length - 14.7cm
Depth - ?m
Widespread Indo-West Pacific
Sweepers school during the day, but at night they float high above the bottom to hunt for larger zooplankton.
Several species are triangular shaped. Ref: https://www.fishbase.se/summary/67361