Two fish caught in Albert Town lagoon by teenage bothers Hudson and Hawk Weathington in April last year have been in the news this week.
They are the biggest of four goldfish donated by the brother to the museum and highlight the folly of releasing goldfish into waterways.
A large orange carp weighing 2.4kg which set a national spearfishing record for wild goldfish started life as a tiny fish in a home fishbowl. The second, a 1.9kg fish, weighing 1.9kg, was spawned in Otago waterways.
Goldfish are technically a freshwater carp and New Zealand waterways are suited to them – and other carp such as Koi and Grass carp – but the opposite doesn’t apply.
“The typical orange-gold colour we think of as typically goldfish is a fancy domestic characteristic people have selectively bred for pet goldfish,” museum Natural Science curator Emma Burns said.
“So the black-bronze colour of the second whopper is the wild-type characteristic. When pet goldfish are released and breed the successive generations in the populations tend see more black-bronze rather than orange-gold.”
Many of the fish in the museum are fiberglass replicas created for the fish gallery in the 1960s. These two have been skinned, treated, and mounted over a custom mannequin and then painted.
“The taxidermist (Wildmounts) often does trophy mounts for salmon and trout, but this is his first “trophy goldfish,” Emma Burns said.
It is Illegal to release pet goldfish, and in the Wanaka area the population is a growing problem for DOC and Fish and Game.
The grazing habits of the fish causes problems for native fish, and they are sometimes also dumped with oxygen weed, which is pest plant.