Those goldfish swimming around in your tank can get very big under the right circumstances and encounters with giant goldfish are becoming more common every day.
The Great Lakes of the United States appear to host millions of the small carp.
Goldfish (family cyprinidae) are one of the most common fish kept as pets in home aquariums. Poor water quality and inappropriate temperature can stunt growth.
Giant goldfish are nothing more than pets released by careless owners. They quickly grow well past their normal small size and often reach several pounds.
The upper size limit is unknown, but reports are that a fisherman caught a 67 pounder.
According to CNN the fish was caught in France by a British angler. CNN referred to the fish ,named Goldy for her color, both as a goldfish and a carp closely related to a goldfish.
Most giant giant goldfish weigh in around 3 pounds. The big fish cause problems in lakes. The obvious solution, goldfish filets, is out of the question. They have too many bones, they taste and smell awful and can carry disease or toxins.
According to Brittanica goldfish are a member of the carp family. These fish are native to east Asia and were domesticated centuries ago. As far as size goes the encyclopedia says they do revert from their aquarium size to a “normal” size.
“Escaping from park and garden pools, the goldfish has become naturalized in many areas of the eastern United States. Upon resuming wild life, it reverts to its original colour and may grow from an aquarium size of about 5–10 centimetres (2–4 inches) to a length of up to 30 centimetres.” A weight of 67 pounds would certainly qualify as a giant goldfish. (Links in original)
Goldfish are omnivorous bottom feeders so they have a range of feeding options and seem to survive well.
Human intervention has created many dozens of different goldfish, Britannica says.
“The goldfish is naturally greenish-brown or gray. The species, however, is variable, and numerous abnormalities occur. A deviant fish may be black, spotted, golden, white, or white with silver; it may have a trilobed tail fin or protruding eyes; or it may lack the normally long dorsal fin. Centuries of selecting out and breeding such abnormal specimens have produced over 125 breeds of goldfish, including the common, pet-shop comet; the veiltail, with a three-lobed, flowing tail; the lionhead, with a swollen “hood” on the head; and the celestial, with protruding, upward-directed eyes.” (Link in original)
Invasive snakeheads are another troubling fish species. But they are apparently good on the grill.