Gone fishin'! Giant former pet goldfish found living in WA waterways

Giant former pet goldfish the size of footballs have travelled hundreds of kilometres through Western Australian waterways, new research has found.

Weighing up to 1.9kg, the goldfish enter river systems after being dumped from aquariums into catchment lakes.

The giant goldfish found in WA waterways.

Murdoch University researchers say the fish are thriving in WA's south, where they have the fastest known growth rate of the species in the world.

"Our research discovered the fish displayed significant seasonal shift habits during breeding season, with one fish moving 230km during the year,"
Dr Stephen Beatty said.

But he warned the invasive fish had the potential to impact water quality, introduce disease, disturb habitat and compete with native species putting them under serious pressure.

Dr Beatty says owners should not release pet fish into waterways, but return them to pet stores if they're unwanted.