The RSPCA is calling on the government and local councils across England to ban funfairs from giving away goldfish in plastic bags as prizes.
The animal-welfare charity said the creatures silently suffer “immense pain and stress” by being put in small bags and handed out to fair-goers.
Many goldfish die before their new owners even get them home.
Goldfish are sensitive and sentient beings, capable of feeling pain, the charity says. But when kept in water in bags for hours on end, they may suffer from shock, oxygen starvation or sudden changes in water temperature, and many do not recover.
The charity said giving pets away as prizes also damages how animals are perceived by society.
More than 160 English councils out of around 300 have banned funfairs from using goldfish as prizes.
District and borough councils, unitary authorities and in some cases, town or parish councils, usually own the land where funfairs operate.
All of Wales's 22 local authorities have restricted the activity on their land, but giving away goldfish is legal on private land in both England and Wales.
So the RSPCA is also calling on both the UK and Welsh governments to outlaw giving pets as prizes.
Goldfish, which can live for up to 30 years, may grow up to 30cm long, and experts say young ones need at least 60 litres of water each, while adults need even more space.
But at funfairs, the bags of water used are small so the oxygen runs out unless replenished frequently, the charity explained.
“There is no way to control the temperature, and the bags are often placed in direct sunlight, so they could overheat,” a spokesperson said.
“We have also received reports of dead fish lying in the plastic bags, filled with 'green slime' while the games continue.
“Transport home will also be stressful; goldfish are easily stressed by sudden changes to their environment. Once 'home', the owner may not have prepared the right environment.”
In 2019, a man who swallowed a goldfish at a funfair was banned from keeping them as pets.
Evie Button, an RSPCA animal welfare expert, said: “They're misunderstood pets as they can make great companions; but can be challenging to look after and owners must do their research before they acquire the fish, not afterwards.
“Handing someone a sentient animal in a plastic bag full of water as a prize can clearly encourage individuals to not treat them as a sentient being, but rather as a worthless object that can be thrown away.”
In a survey of more than 2,200 adults last month, nearly three in four (73 per cent) agreed that local governments should ban the giving of pets as prizes on council-owned land, and more than eight in 10 (84 per cent) said keeping a goldfish in a bag was cruel.
A Department for Food and Rural Affairs spokesperson said: “It is an offence to cause an animal any unnecessary suffering. We are clear that if anyone considers that an animal is suffering at a fair, they should report it to the relevant local authority who have powers to investigate such matters.”
The Local Government Association declined to comment.
