Round fish bowls have smaller water surface area, which affects the amount of oxygen in water.
Belgium is planning to ban the round goldfish bowls, according to The Telegraph. Quoting officials in the Belgian government, the report said that the traditional bowls "cause stress to the fish and should be banned on animal welfare ground".
The report, which is behind a paywall, further said that this is part of an overhaul of the country's animal laws.
Belgian daily La Capitale quoted animal welfare minister Bernard Clerfayt as saying: “We know that the round jar has an impact on fish stress.”
According to Belgian government documents, round tanks often have a smaller water surface area than square or rectangular ones, which affects the amount of oxygen absorbed into the water, La Capitale said in its report.
A small surface area risks the “health and well-being of the fish”, the news report further said.
The proposed ban would apply only to the Brussels-Capital region, the newspaper further quoted the minister as saying. He added that the government would prohibit the sale of round bowls but not the use of them.
“We are not going to start controlling the size of the aquarium in each household. Prohibiting the sale of bowls would be much more effective,” said the minister.
Talking about overhauling the animal welfare law, Mr Clerfayt said that fireworks and electric dog collars will also be added to the list of items deemed harmful to pets.
Belgium already has some of the strictest laws against animal cruelty. The worst such cases are punishable with a 15-year prison sentence and a fine of 10 million euros.
In January, news agency Reuters carried a report saying a leading French aquarium vendor has stopped selling round fish bowls because they "drive fish mad and kill them quickly".