As the name suggests, it is box-shaped. Boxfish are also known for their armored and rigid body which in most cases would inhibit locomotion. This disadvantage is offset by the boxfish's carapace shape which is much more advantageous for its evolved style of swimming- ostraciiform locomotion. When juvenile, it is bright yellow in color. As it ages, the brightness fades and very old specimens will have blue-grey to black colouration with faded yellow. It feeds mainly on algae, but will also feed on sponges, crustaceans and molluscs. The fish's diet consists of marine algae, worms, crustaceans, molluscs, and small fish. Learn more about Yellow Boxfish