Orange-Spotted Filefish

Oxymonacanthus longirostris

The orange-spotted filefish (Oxymonacanthus longirostris), also known as the harlequin filefish or longnose filefish, is a small, brilliantly colored filefish reaching about 12 cm in length. Its elongated body is covered in vibrant orange spots on a turquoise to green-blue background, creating one of the most eye-catching color combinations found on any reef fish. The snout is long and narrow, adapted for picking individual coral polyps from branching Acropora corals, its exclusive food source. This extreme dietary specialization means the species is entirely dependent on healthy Acropora coral for survival. It is found throughout the Indo-Pacific, from the Red Sea to Fiji, inhabiting shallow coral reefs with abundant Acropora growth. Orange-spotted filefish are typically seen in pairs, maintaining long-term pair bonds. They sleep by biting onto a coral branch with their small teeth, hanging motionless among the branches. This species is considered highly vulnerable to coral bleaching events, as loss of Acropora directly eliminates its food supply. Finding a pair on a reef is a sign of excellent coral health.