A very diverse genus
The genus Betta includes more than 70 described species, all from South-East Asia: Thailand, Cambodia, Laos, Vietnam, Malaysia and Indonesia. They live in calm, shallow water: rice paddies, marshes, ditches, forest streams and peat swamps with dark, acidic water.
In the wild, they all have short fins. The spectacular veils of the aquarium Betta are the result of more than a century of selective breeding.
Two ways to protect the eggs
- ✓Bubble-nesters: the male builds a bubble nest at the surface and guards the eggs there, like the splendens.
- ✓Mouthbrooders: the male holds the eggs in his mouth until they hatch, without eating, for roughly one to two weeks.
The splendens complex
The fighting fish's closest relatives: iridescent bubble-nesters.
Betta splendens
The wild form
📍 Thailand, Cambodia, Laos, Vietnam
Red-brown body with blue-green sheen, short fins. Listed as "vulnerable" by the IUCN: its habitat is shrinking and crosses with released farmed fish threaten pure populations.
Betta imbellis
The peaceful betta
📍 Southern Thailand, Malaysia, Sumatra
Blue-green body and red-edged tail. Much less aggressive than the splendens, but males stay territorial: a large, densely planted tank is essential.
Betta smaragdina
The emerald betta
📍 North-east Thailand, Laos
Emerald-green scales that look like chain mail. Lives in the rice paddies and ponds of the Isan region.
Betta mahachaiensis
The Mahachai betta
📍 Mahachai area, near Bangkok
Described in 2012. Lives in slightly brackish swamps among nipa palms. Its tiny range, eaten away by urban growth, makes it especially threatened.
Betta siamorientalis
The eastern betta
📍 Eastern Thailand, Cambodia
Also described in 2012, from populations long mistaken for the splendens. One of the species that have only recently been well understood.
Betta stiktos
The spotted betta
📍 Cambodia
Described in 2005. The least known of the group, it remains rare in aquariums and among breeders.
The mouthbrooders
Less showy, often larger, and much sought after by enthusiasts.
Betta macrostoma
The "Brunei beauty"
📍 Brunei and northern Borneo
Up to about ten centimetres, in bright orange and red. Protected in its home country: only buy captive-bred fish.
Betta albimarginata
The white-edged betta
📍 Eastern Borneo
Small (about 5 cm), orange-red with fins edged in black and white. Peaceful, it suits a small, well-planted tank.
Betta channoides
The snakehead betta
📍 Eastern Borneo
Small and red, with an elongated head like a snakehead fish. Lives in soft, acidic forest streams.
Betta pugnax
The forest-stream betta
📍 Malay Peninsula
The species that gave its name to the pugnax group, a set of mouthbrooders from forest streams.
Keeping them
What they need
- ✓Soft, often acidic water (pH 5 to 7 depending on species)
- ✓A well-covered tank: they are excellent jumpers
- ✓Plenty of plants, hiding places and leaf litter (catappa)
- ✓Soft light and very little current
- ✓Live or frozen food: many refuse pellets
Buying them responsibly
Choose captive-bred fish from breeders or specialist clubs. Many wild species are threatened, and some are protected in their home countries.
Always record the scientific name and, if possible, where the line comes from: that is what keeps populations pure.