a large, edible fish, Nematistius pectoralis, inhabiting the warmer waters of the Pacific Ocean, having the first dorsal fin composed of brightly colored filamentous rays.
roost·er·fish (rōō'stər-fĭsh') n.
pl.roosterfish or roost·er·fish·es A brightly colored food and game fish (Nematistius pectoralis) found from the Gulf of California to Panama.