They are found around New Zealand, usually in water no more than 200 metres deep. In spring and summer, they congregate in large numbers in broad shallow bays. In autumn, they migrate to the outer shelf. Most Rig make extensive coastal migrations. The females appear to travel the greatest distance-often up to 200 kilometres.
Pale golden-brown to grey body above with numerous small blue and white spots and white below. There are no spines or dorsal fins.
Rig belong to the Triakidae family (smooth dogfish).
Most females breed every year. Following a 10 to 11 month gestation period, Rig give birth in shallow coastal waters in spring and summer. Their young are born in litters of 10 to 20 pups measuring 30 centimetres. Juveniles disappear into deeper waters when the temperatures drop in autumn. Their growth rate is relatively rapid, Rig reach maturity at four to five years.
Rig are caught in coastal waters throughout New Zealand after their spring migration, usually in long set nets in shallow water (less than 50 metres deep).