Distinctive Characters: Dorsal fin with 3 spines and 24-26 rays. Anal fin with 23-24 rays. Pectoral rays 14-15. A deep groove before eye. 4 or 5 rows of small spines posteriorly on sides of body. Second dorsal and anal fins slightly elevated anteriorly. Caudal fin rounded to double emarginate.
Colour: Yellowish, the scale centers dark brown to dark olive, abruptly whitish posteriorly. A wedge- shaped blackish bar from top of head to gill opening, enclosing eye. A broad blackish streak on upper lip crossed by two narrow pale blue bands.
Habitat and Biology: Found in a wide ranging of habitats but mainly on reef slopes. Feeds on a wide variety of benthic invertebrates, including sea urchins, corals and molluscs.
Remarks: Balistoides viridescens is fairly common in the Maldives and ranges widely from lagoons to deep reef slopes. Eggs are laid in nests on sandy or rubble patches on the slope. These are protected by the adults, which drive away any intruders including divers with great ferocity.