Orfe | golden orfe | ide
Leuciscus idus (Linnaeus, 1758)
This member of the Cryprinidae family is native to northern Europe where it is valued as a coarse angling fish. Orfe eggs were illegally imported to New Zealand by mail sometime in the 1980s. Subsequent releases occurred between 1985–86 in at least 8 and possibly 5 more sites north of Auckland. The current status of these populations is in doubt; some believe orfe failed to survive in at least 7 of these sites while others are less certain. At least one release site remains unknown and it seems likely that orfe persist in the wild in at least one location in New Zealand.
In Europe, wild orfe are usually greyish brown with silver bellies. However, the variety of orfe present in New Zealand (the golden orfe) is derived from ornamental pond stocks and thus closely resembles rudd. Although it is not known if the two species co-exist, on orfe the scales are smaller and the fins more orange than red coloured. Rudd also have a small projection at the base of their pelvic and pectoral fins. Eventually, the orfe’s golden colouration may revert to the wild type.
Little is known about the biology of orfe in New Zealand. In Europe they primarily inhabit slow-flowing waters. Their food consists of aquatic invertebrates such as worms and snails, but large orfe may consume other fish and aquatic vegetation. Like the other Cyprinidae, orfe are prolific breeders and large females may contain tens of thousands of eggs. Whether they become a nuisance species in New Zealand or will be successfully eradicated remains to be seen.