Oplegnathus

Oplegnathus is currently the sole recognized genus in the knifejaw family (Oplegnathidae) of marine centrarchiform ray-finned fishes.^[5] The largest, the Cape knifejaw, can reach a maximum length around 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.^[6]

Oplegnathus Temporal range: Middle Eocene–present PreꞒ Ꞓ O S D C P T J K Pg N [1]
O. fasciatus
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Actinopterygii
Order:	Centrarchiformes
Family:	Oplegnathidae Bleeker, 1853[2]
Genus:	Oplegnathus J. Richardson, 1840
Type species
Oplegnathus conwaii J. Richardson, 1840[3]
Synonyms[4]
Scaradon Temminck & Schlegel, 1844 Ichthyorhamphos Castelnau, 1861 Scarostoma Kner, 1867

The earliest records of knifejaws are fossilized beaks, with attached teeth, known from middle Eocene-aged sediments of the La Meseta Formation of Antarctica. Their early occurrence in Antarctica supports it having temperate climate during the Eocene, and that knifejaws had a wider distribution in the past than today.^[1]

Species

The currently recognized species in this genus are:^[7]

• Oplegnathus conwayi J. Richardson, 1840, 1840 (Cape knifejaw)
• Oplegnathus fasciatus (Temminck & Schlegel, 1844) (barred knifejaw or striped beakfish)
• Oplegnathus insignis (Kner, 1867) (Pacific beakfish)
• Oplegnathus peaolopesi J. L. B. Smith, 1947 (Mozambique knifejaw)
• Oplegnathus punctatus (Temminck & Schlegel, 1844) (spotted knifejaw)
• Oplegnathus robinsoni Regan, 1916 (Natal knifejaw)
• Oplegnathus woodwardi Waite, 1900 (knifejaw)