Crayfish or koura (Paranephrops)

Taxonomic group

Parastacidae: Paranephrops

Diagnostic features

Paranephrops is the only freshwater crayfish genus in New Zealand. Juveniles could at first glance be mistaken for Paratya shrimps, but only Paranephrops have large chelipeds (pincers) on the first pair of walking legs. Mature Paranephrops are many times larger than Paratya shrimps.

[Paranephrops planifrons] (North Island). Image: Stephen Moore Image — Paranephrops planifrons (North Island). Image: Stephen Moore

[Paranephrops zealandicus] (South Island). Image: Stephen Moore Image — Paranephrops zealandicus (South Island). Image: Stephen Moore

Typical habitats

Paranephrops are widespread in streams and lakes around New Zealand. They are usually found amongst the shelter of stones, woody debris or weed beds.

Feeding

They are omnivores, eating mostly plant matter, but also eating invertebrates when they get the chance.

Indicator value

Hard bottom: 5
Soft bottom: 8.4

The tolerance values (ranging from 0 to 10) give an indication of which are the sensitive taxa (values of 8 or more) and which are the tolerant taxa (values of 3 or less). For more information see: Indicator species

Paranephrops are common in bush covered and farmland streams of moderate to good water quality. They have moderate to high tolerance values of 5 (hard bottom sites) and 8.4 (soft bottom sites).