Threadfin butterflyfish

Chaetodon auriga

Distinguished by an elegant chevron tapestry and an eye-catching trailing filament, the threadfin butterflyfish is an iconic, widely distributed chaetodontid across shallow tropical coral reefs. Its disc-shaped, pearlescent white body features two sets of fine grey lines crossing at right angles across the flanks, creating a distinct chevron pattern. A bold black vertical bar masks the eye, while the posterior body, soft dorsal, and caudal fins blaze in bright canary-yellow. Adults develop a prolonged filamentous streamer extending from the upper soft dorsal fin, behind which rests a prominent, dark false-eye spot (ocellus) engineered to misdirect predators. Distributed from the Red Sea and East Africa across the tropical Pacific to Hawaii and the Marquesas, it navigates lagoons, sandy reef flats, and outer slopes between one and thirty-five meters depth. As a broad-spectrum omnivore, it browses on coral polyps, polychaete tentacles, sea anemones, and algae. Maximum recorded total length attains twenty-three centimetres.

Meet this fish