- English Name : Citron butterflyfish
- Local Name : Rulhigadha bibee
- Size : Max. 12 cm
- Family : CHAETODONTIDAE
- Order : Perciformes
- Distinctive Characters: Dorsal fin with 14 spines and 20-22 rays. Anal fin with 3 spines and 16 or 17 rays. Pectoral fin with 13 or 14 rays. Body depth 1.7-1.9 in standard length.
- Colour: Pale yellow with small spots of variable colour on each scale and a black border on anal fin. A prominent black band through the eyes.
- Habitat and Biology: Common in shallow exposed reef flats and seaward reefs where coral growth is sparse. Usually seen in pairs. Feeds on coral polyps, benthic invertebrates and algae.
- Distribution: Indo-Pacific.
- Remarks: Chaetodon citrinellus is an aggressive species which frequently erects the dorsal spines and faces
downwards in a defence position when approached by other fishes or divers.