They are small fish, very thin, generally reaching about 7.5 to 12.5 centimeters (3 to 5 inches) in length and height, and 1 to 2 centimeters (< 1 inch) in thickness, and are bright yellow in color across their entire bodies. During the night, in common with many fish, their color fades. A prominent brownish patch develops in the middle of both sides which then makes plane a horizontal white band. This probably helps camouflage the fish during periods of inactivity. They rapidly resume their all-over sulphur-yellow upon waking.
They have an arrow-like shape due to their dorsal and ventral fins being almost an extension to their bodies, and a long snout-like mouth used (as with other tangs) to eat the algae off rocks and coral. They are almost fully herbivores, and have become a popular fish in the marine fish hobby. They also have a sharp spine located near their tail.
Wild grasses, algae, lettuce, and other plant life in general. The yellow tang can also be found eating shrimp and other smaller animals.
