All of the groupers […] are game-fishes worthy of the steel of the angler, and grow to goodly size, twenty to forty pounds. […] Those named are rather sober in their garb, which is more or less marbled or spotted with black, but some of the groupers about Key West are remarkably handsome fishes, and are much given to very gay and bizarre attire; their coats, like Joseph's, being of many colors. […] But the dude of the family is the niggerfish, which is a rag-time dandy, always in full dress for a cake walk.
Source: wiktionary