Distinctive Characters: Dorsal fin with 3 spines and 24-28 rays. Anal fin with 20-24 rays. Pectoral fin with 12-14 rays. Third dorsal spine of moderate length (not minute). No groove in front of eye. Second dorsal and anal fins not elevated anteriorly. Caudal fin slightly rounded.
Colour: Dark greenish brown with bright orange lines. Adult male with no bands on dark snout.
Habitat and Biology: Occurs in a variety of habitats on reef flat and reef edge. Extremely varied diet: live
corals, benthic algae, sea urchins, crustaceans, other benthic invertebrates and also small fishes. Distribution: Indo-Pacific.
Remarks: Balistapus undulatus is a common inhabitant of the Maldivian reefs. It is an interesting aquarium fish.