It’s a common sight to see an arc-eye hawkfish perched in a head of coral, well assuming you’re in the water that is. If a predator comes along, they slip deeper into the coral for protection.
There are two patterns to these fish. Sometimes they’re paler than this one and have a distinctive white stripe on the side. One study has shown that the lighter fish tend to inhabit slightly deeper water where the coral is spread farther apart. Both patterns have the arc behind the eyes and the blue and red bars on the gill covers.