Siamese fighting fish

The Siamese fighting fish, often just called a betta, is one of the most beautiful fish you can imagine. With its flowing, colourful fins and bright, shimmering scales, it has earned the nickname “the designer fish of the aquatic world.” Bettas come in almost every colour, from deep blue and red to green, purple, and gold.

Bettas have a clever trick for living in warm, shallow water that does not hold much oxygen: they can gulp air straight from the surface. This lets them survive in places where many other fish could not, like quiet ponds and puddly rice paddies. People noticed how special they were long ago — bettas were first kept and bred in Thailand more than 1,000 years ago, making them one of the earliest tamed fish.

When a male betta is ready to become a father, he builds a floating nest out of bubbles at the top of the water. He gulps air and blows sticky bubbles one by one until the nest takes shape. After the eggs are laid, he tucks them safely into the bubbles and guards them, keeping watch until the tiny babies hatch a day or two later.

Both male and female bettas can puff out the covers over their gills and spread their fins wide to look as big and grand as they can. They do this to tell a rival “this is my space” or as part of courtship. It is a showy display of colour rather than anything to worry about — a bit like a peacock fanning its tail.

Even though bettas are very common in aquariums around the world, their wild cousins need our care. In the shallow waters of central Thailand where they come from, wild bettas are listed by the IUCN as Vulnerable, because their homes are being lost to pollution and to farmland spreading across the land. Protecting these gentle wetlands helps keep wild bettas swimming for years to come.