Blue TangAcanthurus coeruleus
A member of the surgeonfish family, the Blue Tang is the very common and will often school with large numbers of other Blue Tang and Surgeonfish to graze on algae. The Adult Blue Tang, like other members of the Surgeonfish family have poisonous spines on both sides of their bodies just in front of their tail fins. The Blue Tang has a white or yellow spines and the other Surgeonfish have dark blue or black spines. The Blue Tang has a rounder body than the other Surgeonfish. They can pale to almost white and darken to a deep bluish-brown color. Size is not a measure of age. They can grow to 15 inches, but the average at snorkeling depths is around 8 inches.