Wedgetail Triggerfish

Found singly or in small schools over coral, bare rock and rubble, in shallow surge zones of outer reefs. Very territorial.
Juveniles found over algae reefs.

Wedgetail Triggerfish is known in Hawaii as Huma Huma Trigger, or humu-humu-nuku-nuku-a-puaa by native Hawaiians and has recently been reinstated as the Hawaiian state fish.

Triggerfish have a hard spine Dorsal Fin that can be locked.
When sleeping this spine is used to wedge them into place in a crevasse and so deter predators from pulling them out of their bed!
The spine is also held erect as a warning to other fish to stay away.
Several large Titans blow shallow depressions in the sand for nesting and if approached will raise this spine as a warning, if ignored they may charge, even divers! especially the Titan Triggerfish who will take a tasty bite. Beware.