New Zealand has two freshwater crayfish species, with this species being found throughout the North Island and in Northern and West Coast of the South Island. They are slightly smaller (up to 70 mm long in streams) and also less robust and hairy than their Southern cousins. Lengths of crayfish are greatest in lakes (to around 160 mm), with ages over 3 years not being uncommon. They are largely nocturnal in their habitat of lakes, streams, and wetlands, where they feed opportunistically on aquatic insects and vegetation. Freshwater crayfish are thought to function as a keystone species, with the modifications they make upon the environment permitting as greater range of species to exist than if they were not present. These crustaceans also provide an important food source for larger fish and waterfowl. All koura are non-migratory, and carry their eggs and then their developing young under their tails. Juveniles are released as perfect miniatures of the adult, able to fend for themselves immediately.

Conservation status: Northern Koura have been lost from a significant proportion of their historical range through habitat deterioration and the introduction of exotic fishes including trout.

Southern Koura are found through the east and south of the South Island and Stewart Island. They are larger, (about 80 mm long) and have distinctively, hairy spinier pincers. Otherwise they are very similar to that of the Northern Koura (Paranephrops planifrons). As with their northern cousins, they normally shelter in streams and rivers between stones and cobbles. In lakes they burrow into the muddy bottoms at depth during the day, and rise to the shallows to feed at night. They are also able to burrow down into the bottoms of temporary waterbodies that dry out, waiting until the water returns. However, if they do become extinct from a waterway, they are unable to recolonise again afterwards, being without a marine life-phase as does much of our other freshwater life in New Zealand. Local extinctions therefore remain around New Zealand in this way, e.g. from pollution and habitat damage that has occurred in the headwaters of their waterbodies.

Conservation status: Southern Koura have also been lost from parts of their historical range through habitat and water quality damage, and the introduction of exotic fishes; especially trout.