Yellow boxfish (Ostracion cubicus)

   Medium-sized specimens are light brown with blue spots surrounded by black spots or a black border. Larger adults are mustard-brown with blue-green hues and have a protrusion on the upper lip. The fish's body is protected by an exoskeleton, a shell made of fused bony plates. An additional defense mechanism, in addition to the shell, is the ability to secrete a toxic mucus when threatened.