This is Cephalopholis miniata, a grouper from the indo-pacific often called the coral trout or coral hind. Unfortunately its also known as coral cod, coral grouper, bluespotted rock cod, liglig, rero, red rock perch, and, erm, 青星九棘鱸 and ചെന് ചേരചാമ്മാം . In fact to save me typing a list of common names can be found here.
My point is simply that common names don't work well for fish - there are too many fish, in too many places with too many languages so scientific names work for fish in a way that is more important perhaps than knowing them for birds or mammals. Whatever you care to call it, this grouper is a gorgeous fish.
By the way, blue water filters out red first so whilst he may look garish to us when properly lit with my strobes to fish whose eyes have evolved in the blue deep he probably looks (or rather doesn't look - you know what I mean) quite stealthy.