Spotted Knifejaw

Oplegnathus punctatus

The Spotted Knifejaw is a reef-associated fish known for its distinctive black-brown body adorned with irregular black spots. It features a unique dental structure where its teeth fuse into a parrot-like beak, enabling it to feed on hard-shelled prey. Typically, the species can grow up to 86 cm in length and weigh up to 12.1 kg. Divers can identify this fish by its single dorsal fin and ctenoid scales, which are small and rigid. The Spotted Knifejaw inhabits rocky and coral reefs, often found in the Indian and Western Pacific Oceans, including regions near southern Korea, Taiwan, China, Japan, and Hawaii. It prefers depths ranging from 3 to 135 meters, although most observations occur at depths shallower than 40 meters. Juveniles are often seen near drifting seaweed, while adults are more prevalent in rocky habitats. Dietary habits of the Spotted Knifejaw vary with age; juveniles consume more seaweed and zooplankton, while adults favor larger prey like cnidarians and crustaceans. The species is not currently evaluated for conservation status, but it is valued in aquaculture for its rapid growth and taste. Divers encountering this fish may observe its calm behavior as it navigates the reef environment.