Acanthurus pyroferus is a species of tang highly variable in coloration as a juvenile. Some mimic several pygmy angelfish species before changing color dramatically as an adult. The angelfish have a sharp spine the tangs do not have so there is an advantage of looking like an angelfish when they are small. This one is a Centropyge vrolikii mimic. For other photos of this mimic tang, see here.
Posted 1 February 2011