The Epic Tale of the Humble Goldfish

It is a common household pet, loved by inquisitive toddlers and parents alike, but the humble goldfish, swimming amiably in its aquarium, hides a remarkable history - one of cultural, scientific, and environmental significance.

Research conducted by Professor Anna Marie Roos, Professor of the History of Science and Medicine at the University of Lincoln, for a new book about the goldfish has revealed the fascinating past of a creature that has become an iconic cultural commodity.

“We know that the goldfish is native to China, the southern Amur River basin, and Korea, and was domesticated more than a thousand years ago,” explained Professor Roos. “Evidence based upon molecular genetics has suggested that goldfish may have originated from the hybridization of the red crucian carp and common carp, which was bred for food."

It appears that goldfish have always been a commodity in one form or another, and were especially so in 19^th-century England and America, their popularity bound up with the consumerist culture of the newly emergent middle class, industrialisation, and booming foreign trade.

The manufacture of round glass fishbowls and the freshwater aquarium, as well as the evolution of scientific aquaculture and commercial goldfish farming, played a role.

The opening of the first public aquarium in 1853 in London at the Zoological Gardens at Regent’s Park also contributed to the popularity of keeping fish as pets. Goldfish hawkers from London would tour around suburbs in the 19^th century offering the fish for sale. It was wrongly believed they did not have to be fed but could subsist from ‘animalcula’ in the water, making them attractive to keep as pets.

Professor Roos says that the goldfish is also of scientific importance. “In their sensory organs, they are a lot like us, making them ideal experimental models. They are also smart enough to be trainable. Studies in visual perception and cognition have revealed that goldfish perceive some of the same colours as humans.”

In 2011, experiments by Caroline DeLong at Rochester Institute of Technology showed that goldfish could recognise shapes, in particular a black circle attached to the tank. The composition of their skin is comparable to ours as well. Just like us, their skin pigment cells or chromatophores produce pigment in response to light, so they can get a tan.

As part of her fieldwork, Professor Roos travelled to Zeeland in the Netherlands to tour the house of Job Baster, the 18^th-century physician who was the first to breed goldfish in captivity in Europe, successful as he paid careful attention to their diet and environmental conditions.

There is, however, a darker side to the goldfish tale, as Professor Roos explains: “What people don’t realise is that goldfish can be toxic for the environment. Those that are flushed down the toilet, escape from ornamental ponds, or are dumped in lakes when fishermen use them as bait can interbreed with common carp, multiplying and disrupting the ecosystem. They get numerous, they get big, and they out eat and outcompete native fish.

In this sense, the goldfish seems to be a particularly salutary case study in this era of climate change and environmental awareness.