Kahawai have a firm, solid body with strong swimming muscles. They vary from grey-blue to blue-green above and are silvery beneath with scattered dark grey spots on the back and
flanks. They lack the yellow stripe and yellow fins characteristic of the kingfish.
Young fish, up to 25cm, also have vertical rows of spots below the lateral line. They are easily distinguished from similar sized kingfish by the high spiny dorsal fin that is joined to the soft rayed portion of the fin
AGE & GROWTH
Most kahawai have an average size between 40-50cm long and an average weight of 1 to 2kg. Whilst an impressive weight would be around 6kg, some fish have weighed up to 15kg have been reported to be 26 years old, which is surprising for an organism of this size and such an energetic lifestyle. Larger kahawai are often mistaken for kingfish.
HABITAT & FEEDING
Kahawai are found throughout New Zealand but are more common north of Kaikoura. Juveniles prefer shallow coastal waters while adults can be found in open water. These fish are fast swimming, active carnivores which feed primarily on smaller fishes such as anchovies and yellow-eyed mullet, although they will feed on euphausid crustaceans when these are abundant.
Kahawai are a schooling fish and when hunting for small fish or krill, employ a herding technique that they themselves may be unaware of. As shown in the picture below, kahawai drive the prey to the surface and then gobble them up while poking their backs high out above the water..
These fish have surprisingly soft lips which can be easily ripped – thus losing them from the hook. Both their jaw and pharyngeal teeth are hooked for seizing and holding prey, which
is then swallowed whole.
Rapid moving schools of this fish are often seen by divers ghosting past at the limit of visibility where they can reach speeds of between 7 and 12km/hr.
Kahawai make lengthy migrations, probably associated with spawning and seasonal changes in the abundance of food. With their ability to cover vast distances quickly because of their strength and speed, it makes it impossible to protect them by means of marine reserves.
Kahawai have flesh of medium texture which comes apart in thick flakes which lightens from greyish to white when cooked. It is best to kill kahawai and bleed as soon as possible as the flesh goes off quickly. They do have distinctive brownish blood lines when filleted. Kahawai are reasonably good eating but especially good for curries or fish pie and are brilliant smoked.