The Bluehead (Thalassoma bifasciatum) is a species of wrasse that is easily identified by its bright blue head. A secondary identifying feature are the two dark bars behind the head, which are separated by a white band.
Blueheads are commonly seen on reefs, particularly in shallow areas. They are one of the prettiest and most colorful fish in shallow reef areas.
Here is a Bluehead seen from the front. In the background are a variety of juvenile wrasses.