Oplegnathus is currently the sole recognized genus in the knifejaw family (Oplegnathidae) of marine perciform fishes. The largest, the Cape knifejaw, can reach a maximum length of about 90 cm (35 in). Knifejaws have teeth fused into a parrot-like beak in adulthood. They feed on barnacles and mollusks, and are fished commercially. They are native to the Indian and Pacific Oceans.