Terminal phase stoplight parrotfish.
Top of photo.
The stoplight parrotfish (Sparisoma viride) is a sex-changing fish inhabiting coral reefs in Florida, Caribbean Sea, Gulf of Mexico, Bermuda and as far south as Brazil. Its typical length is between 1 and 1.5 ft (30 and 46 cm), but it can reach 2 ft (61 cm) at times. It is normally found during the day at depths between 15 and 80 ft (4.6 and 24 m).