The Blue Tang, a surgeonfish, is commonly found in the Tropical Atlantic Ocean. It can grow up to 16 inches long. Its colors change during growth, starting as a yellow juvenile and then becoming a yellow tailed blue sub-adult before entering the final blue adult phase. The adult fish 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 swelling and discoloration. Some species are even thought to possess poison glands on their caudal spines.
Exhibit: Flint River Gallery, Gift Shop Tank