Distinctive Characters: Dorsal fin with 2 detached spines and 43-49 rays. First dorsal spine originates over eye. Anal fin with 46-52 rays. Pectoral fin with 13-15 rays. Body elongate and very compressed. Profile of snout concave. Mouth small and upturned. Caudal peduncle deeper than long. Caudal fin rounded and long (longer than head), posterior edge often ragged.
Colour: Olive brown to grey with irregular blue spots and short lines and small black spots.
Habitat and Biology: Seen in lagoons or on outer reef slopes to depths of about 20 m. A shy and solitary species, but occasionally observed in small groups. Feeds on a wide variety of benthic organisms including algae, sea grasses, hydrozoans, gorgonians, anemones and tunicates.
Remarks: Aluterus scriptus is one of the largest of the filefishes. It is similar to A. monoceros, but A. monoceros has a convex dorsal head profile and a bulbous ventral head profile, a much smaller caudal peduncle depth and also a much shorter caudal fin.