The powder blue tang, like most fish in the family Acanthuridae family, is herbivorous, eating mostly benthic algae. Acanthurus leucosternon has a diurnal activity. It is solitary, territorial and aggressive with other surgeonfish.The fish can reach an average size of 23 cm (9 in) in length. The body has an oval shape and is compressed laterally. Like other surgeonfishes, Acanthurus leucosternon swims with its pectoral fins. The caudal fin has a crescent shape. The fish has a "surgeon's scalpel," an erected part of the spine located at the base of the tail. The mouth is small and pointed in a beak-like manner with tiny and sharp teeth for reaching narrow spaces of food. They are reef safe and are compatible with most species except other species of fish in the genus Acanthurus.