Kingfish belong to a large and worldwide family of fishes that include trevallies, jacks and jack mackerels. In New Zealand, the family is represented by (yellowtail) kingfish, trevally, at least three jack mackerel species, koheru and a few rare or occasional visitors, such as amalco jacks, samson fish, amberjacks and pilotfish. Kingfish – haku or kahu in Maori – is the largest jack species in New Zealand, growing to 50kg-plus and nearly two metres in length. Restricted to the Pacific and Indian Oceans, kingfish sub-species are present in warm temperate and temperate waters around the world.
The largest kingfish specimens in the world are caught around New Zealand.
Kingfish inhabit rocky shores, reefs, pinnacles and the turbulent waters surrounding offshore islands in waters up to 200m deep. Juvenile fish are pelagic, free-swimming far out to sea and often gathering under floating objects.
Adults are sometimes described as ‘semi-pelagic’ and occur mainly in open coastal waters.
They patrol coastlines and reefs, entering shallow harbours in search of food and frequenting most marine habitats at various times, taking advantage of whatever food sources are available. Some fish take up residency on suitable reefs, seldom moving far from home. Kingfish are active predators preying of other fish, squid and crustaceans. Juvenile fish start their lives eating plankton, but soon graduate to larger prey.
Big kingfish are quite capable of eating live fish weighing several kilos. Kingfish have been reported from right around New Zealand, including Stewart Island and the Chathams, but they are seasonal visitors to southern waters and much more common in the north.
Kingfish hotspots include the waters of Northland’s east coast and the Bay of Plenty-East Cape area. Kingfish grow quickly at first, reaching 2-3kg in their first year. The most recent studies indicate that females reach sexual maturity at around 5-7 years when they are between 78 and 128cm and males between 75 and 93cm. Earlier studies concluded that sexual maturity was reached at 70cm, which is why the legal size limit for kingfish is set at 75cm.
Kingfish may live for up to 20 years.
Spawning takes place in spring and summer when water temperature is around 20°C. They are thought to free-spawn in moderately deep coastal water near the surface, though this behaviour has never been observed.- See more at: Click Here