Koi carp are an ornamental strain of the common carp (Cyprinus carpio) native to Asia and Europe. This species is thought to have been imported into New Zealand accidentally in the 1960s as part of a goldfish consignment.
Koi.
Koi
Koi carp were probably initially released into the wild accidentally from private ponds during large scale flooding. Wild stocks of koi carp were first found in the Waikato River in 1983 by which time they had likely established a breeding population.
Further illegal introductions have occurred elsewhere, for the purposes of coarse fishing (a traditional British pastime involving the catch and release of certain species including koi carp, rudd, perch and tench) and for ornamental purposes in amenity ponds. Isolated populations have been progressively discovered throughout New Zealand.