Acanthurus coeruleus is a surgeonfish found commonly in the Atlantic Ocean. It can grow up to 16 inches (41 cm) long. Common names include blue barber, blue doctor, blue doctorfish, blue tang, blue tang surgeonfish, yellow barber, and yellow doctorfish.
Although the body of the reef fish can vary in shade from light to dark blue, the dorsal, anal and caudal fins are golden blue. As juveniles, the edges on their dorsal and anal fins and the rings around their eyes are purple-blue, blue or blue-green. Their colors change during growth from a yellow juvenile, yellow tailed blue subadult and the blue adult phase.
Acanthurus coeruleus is common off of Florida, the Bahamas, and other places in the Caribbean sea, including Bonaire. Blue Tangs are very common in Belize and especially Ambergris Caye. They are also common in the Gulf of Mexico. They are also found south to Brazil and north to New York and eat krill.
Relationship with humans 
The fish is not under human threat.
The fish is at low value, giving off a pungent stench. Ciguatera poisoning may occur if the flesh is consumed. The adult fish's caudal spine is sharp, and is only out when the fish experiences excitement of some form. These fins can cut very deep into human skin and have been known to result in infections, mainly characterized by swelling and discoloration. Pain from such infections can last for long periods of time, sometimes for hours. Some species of the genus Acanthurus are even thought to possess poison glands on their caudal spines.
Further reading 
- Humann, P. and N. Deloach. Reef Fish Identification: Florida, Caribbean, Bahamas. New World Publications Inc., Jacksonville. pp. 32-33.