Native to the Khorat Plateau in eastern Thailand, a saucer-shaped upland region enclosed by the Mekong River main channel to the north and eastthat. The plateau is drained by the Mun, Chi, Songkhram, and Loei rivers, of which all belong to the Mekong watershed, and B. smaragdina has also been recorded from Mekong tributaries in central Laos.
Type locality is ‘Nong Khai, Thailand’.
Inhabits still and sluggish waters, including rice paddies, swamps, roadside ditches, streams and ponds. These are often shaded by submerged, surface or marginal vegetation and sometimes contain little dissolved oxygen.
Water conditions tend to vary and change rapidly during the annual monsoon season. Substrates can vary from leaf litter to mud, sand, or deep sediment.
Introduction of ornamental forms and other Betta species such as B. splendens is known to be having an adverse effect on the genetic integrity of some wild populations.
Temperature: 22 – 28 °C
pH: 5.5 – 7.5
Hardness: 18 – 179 ppm