Arc-Eye Hawkfish

In the Atlantic there is only one member of the hawkfish family, the redspotted hawkfish, and it is a testament to the biodiversity of the Pacific Ocean that there are at least 15 hawkfishes, maybe more.  Perched on coral this Pacific arc-eye hawkfish waits to ambush small fish or crustaceans.  Not having a swim bladder to provide buoyancy it must dart out to capture prey and then return to rest, perched on its pectoral fins.

We generally assume that nature has a purpose behind each shape and color.  What function  does the bright white stripe on the arc-eye hawkfish serve?  Is it to attract small critters or just a product of natural selection?  The multi-colored arc-shaped markings behind the eye and the three orange dashes on the edge of the gill.  What purpose do they serve?  Sometimes I do not want to know the answer, to me the arc-eye hawkfish is typical of life in the ocean, a beautiful mystery.