Betta

Looks how to spot one

Scaled fish with long flowing fins in most bred strains

A small, slim fish with a slightly upturned mouth. Wild fish are short-finned and fairly muted, while ornamental strains have been bred for large, dramatic fins such as veiltail, doubletail and deltatail shapes. Males carry the brightest colours and the longest fins; females are usually smaller and plainer.13

Personality what they are like

Confident and territorial. Males will not tolerate other males and do best as the only betta in a tank; females can also be territorial in tight spaces. They show off by flaring fins and gill covers and tend to watch what goes on outside the glass.134

Daily activity how busy a day looks

A slow, deliberate swimmer that likes calm water. Plants, floating leaves and hiding spots give it places to explore and rest near the surface.34

Grooming and care the hands-on bits

Keep water warm and stable at about 22 to 30 C, pH roughly 6.0 to 8.0 (wild-caught fish prefer softer, more acidic water) and soft to medium hardness. Use a heater and gentle filtration so long fins are not pushed around by strong currents, and keep the surface accessible because bettas gulp air.32

Home where they are happiest

Seriously Fish recommends a tank with a base of around 45 x 30 cm (about 40 litres) and advises against tiny bowls or jars; about 45 litres is suggested when other fish share the tank. A planted, well-covered tank with calm water mimics the still, vegetated paddies and marshes it comes from.31

Food basics what goes in the bowl

A carnivore that eats small invertebrates and insect larvae in the wild. In the aquarium offer a quality betta pellet or flake plus small live or frozen foods like daphnia, brine shrimp and bloodworm. Feed small portions, as bettas are prone to overeating.134

Company who they like around

Best kept alone or, with care, in a larger tank with calm, short-finned companions. Never house two males together, and avoid fin-nipping species or fish with long trailing fins.31

The story where it all began

People in the central plains of Thailand began keeping and breeding these fish more than 1,000 years ago, originally selecting them for sparring contests between males. Over time breeders also selected for colour and fin shape, producing the ornamental forms seen today. The fish reached Europe in the late 19th century, arriving in France in 1874, and the ichthyologist Charles Tate Regan gave it the name Betta splendens in 1910. Intensive line breeding has since created countless colour and fin varieties, and the wild form is now rarely seen in the hobby. In 2019 Thailand named it the country's national aquatic animal.13

Recognised by the official bits

IUCN Red List

Wild species assessed as Vulnerable (2011)2

Government of Thailand

Declared Thailand's national aquatic animal in February 20191

International Betta Congress

Hobby organisation that runs judged betta shows with its own show standards and classes5