NL·0578Herbarium of the Nature Library
- Name
- Betta splendens
- Family
- Osphronemidae
- Native to
- Central Thailand and the Chao Phraya and Mekong basins (Cambodia, Laos, Vietnam); introduced elsewhere
- Habitat
- Rice paddies, Marshes, Swamps, Ditches
Siamese fighting fish
Betta splendens
Also calledPla kat ปลากัด (Thai) · Ikan laga (Malay) · Betta (aquarium)
A small air-breathing fish of Thai paddies and marshes, bred over centuries for combat and later for flowing colourful fins. Wild populations are now Vulnerable as their wetlands vanish.
The Siamese fighting fish, commonly known as the Siamese fighter, or locally as the betta, is a freshwater fish native to Mainland Southeast Asia, namely Cambodia, Laos, Myanmar, Malaysia, Thailand, and Vietnam. It is one of more than 70 species of the genus Betta, but the only one eponymously called "betta", owing to its global popularity as a pet; Betta splendens are among the most popular aquarium fish in the world, due to their diverse and colorful morphology and relatively low maintenance. Wikipedia
What it can do
- iBreathes air with a labyrinth organ, so it survives in tiny, stagnant puddles
- iiMales build floating bubble nests and guard eggs and fry
- iiiMales flare their gill covers and fins in aggressive displays to rivals
In the field
Field marks
- aWild males: dull reddish-brown with iridescent blue-green scales and red-tinted fins
- bDomestic males: very long, flowing fins in reds, blues and whites
- cUpturned mouth; long anal fin and short dorsal set back
- dFemales smaller and duller, with shorter fins
- Not to be confused with
- Other wild Betta species (B. imbellis, B. smaragdina, B. mahachaiensis) are very similar and best told apart by range and fin and colour details. Gouramis have thread-like pelvic fins.
- Where to see it
- Paddy fields and marshes of central Thailand (wild fish increasingly rare); fish markets of Bangkok's Chatuchak; aquaria worldwide
- When
- Resident; breeds in the rainy season (May–October)
Life & habits
- Diet
- Carnivore: insects and their larvae, zooplankton
- Habitat
- Shallow, still, vegetated waters: paddies, marshes and floodplain pools
- Size
- Around 6 cm
- Lifespan
- About 2–3 years; up to 5 in captivity
Males guard a territory and a bubble nest. After spawning they catch falling eggs in their mouths and place them in the nest.
Where it lives
Recorded sightings
—
geo-referenced records in GBIF, from museums, herbaria and field observers.
Native range
Central Thailand and the Chao Phraya and Mekong basins (Cambodia, Laos, Vietnam); introduced elsewhere
Drag the globe to turn it. Dots are where records exist, not a range map; darker means more records.
In the stacks
Searching the stacks…
Every page naming Betta splendens in the Biodiversity Heritage Library →
Marginalia
Siamese villagers bred short-finned fighting strains (pla kat) for wagering for centuries, and King Rama III is said to have licensed and taxed the fights. In 2019 Thailand declared the betta its national aquatic animal.
Curiosity
The genus name Betta may come from the Malay 'ikan bettah', and splendens means 'splendid'.
Kinship
Photographs: iNaturalist contributors under the licences shown. Records: GBIF.org. Historical plates: Source Library (CC BY-SA 4.0; originals public domain). Summary text: Nature Library editors and Wikipedia (CC BY-SA). Medicinal and edibility notes are historical and educational, not advice. iNaturalist taxon 95748.