- EnglishName: Blackpyramid butterflyfish
- Local Name : Oimathi bibee
- Size : Max. 18 cm
- Family: CHAETODONTIDAE
- Order : Perciformes
- Distinctive Characters: Dorsal fin with 12 spines and 24-26 rays. Anal fin with 3 spines and 20-21 rays. Pectoral fin with 17 rays. Body depth 1.5 in standard length.
- Colour: Dark brown with broad white area in middle of the body. Dorsal spines over white area are yellow. Caudal fin mostly white.
- Habitat and Biology: Commonly found at depths 1-35 m. Usually seen in large schools. Feeds on zooplankton well above the corals, to which it retreats at the approach of danger.
- Distribution: Western Indian Ocean.
- Remarks: Hemitaurichthys zoster is very common in the Maldives. It is unusual for a butterflyfish in that it feeds mainly on plankton, and presumably for this reason has adopted a schooling mode of life unlike most of the butterflyfishes.