parrot fish, any of about 80 species of fishes of the family Scaridae, a group sometimes regarded as a subfamily of Labridae (order Perciformes), found on tropical reefs. Parrot fishes are elongated, usually rather blunt-headed and deep-bodied, and often very brightly coloured. They have large scales and a characteristic birdlike beak formed by the fused teeth of the jaws. The beak is used to scrape algae and the soft part of coral from coral reefs and is strong enough to leave noticeable scars in the coral. The fish grind their food and bits of coral with platelike teeth in their throats.
Parrot fishes range to a length of about 1.2 metres (4 feet) and weight of about 20 kilograms (45 pounds), or occasionally larger. They are variable in colour, the male of a species often differing considerably from the female, and the young may differ from the adult. Parrot fishes are protogynous hermaphrodites; that is, they first function as females and later transform into males.
Parrot fishes are edible but are not, as a group, of great economic importance. The surf, or rivulated, parrot fish (Callyodon fasciatus) is an Indo-Pacific representative of the family; it grows to 46 centimetres (18 inches) or more, and the male is green and orange or red, the female blue and yellow. Atlantic species include the rainbow parrot fish, which grows to about 90 centimetres and is bright orange and green with a blue beak, and the queen parrot fish (Scarus vetula), which grows to about 50 centimetres and is blue with green, red, and orange if male but reddish or purplish with a white stripe if female.