Study Calls for Larger Tanks, Better Environment for Betta Fish

It says tank size should be at least 5.6 litres, with plants, hideouts to ensure their welfare

- Chin Hui Shan

A new study in Singapore found that Betta fish — also known as Siamese fighting fish — should be kept in a minimum tank size of 5.6 litres when displayed for sale and it should contain gravel, live plants and hideouts to ensure their welfare.

This provides sufficient space for the fish to swim around, while a variety of accessories helps simulate their natural environment.

But in pet stores, these popular pet fish, known for their striking colours and flamboyant fins and tails, are often kept in small tanks or even plastic bags, leaving them with insufficient space to swim around.

The study by a team of marine scientists from Singapore, Australia and France examined the impact of housing size and furnishings on the behaviour of Betta fish to understand optimal tank conditions. It was published in the scientific journal Animal Welfare in November 2024.

Betta fish are known as fighting fish because they are territorial and aggressive. The small-sized fish with iridescent bodies and multi-hued tails are typically kept singly to prevent them from attacking one another.

Native to Thailand, the fish can also be found in other South-east Asian countries such as Malaysia, Indonesia and Cambodia.