Powder blue surgeonfish

Deep Six dive site in Similan's, Thailand (2008).
The powder blue tang is light blue with yellow and white highlighted fins. Its face is a uniform black with a white outline. The fish does not undergo color changes as it matures, as some tangs, surgeonfish and unicornfish do. It belongs to the family Acanthuridae, which includes the tangs, unicornfish, and the surgeonfish. In case you are wondering, surgeonfish get their name from the scalpel-like projection located on both sides of their tail. They reach an adult size of about 9-10 inches (23-25 cm).
Habitat: In their natural environment, powder blue surgeonfish are found in shallow waters in the Indian and Pacific Oceans. They are often found along coral reefs where they feed on algae. They are sometimes seen in groups or in pairs.