The emerald betta, Betta smaragdina, is a bubble-nesting labyrinth fish from the Khorat Plateau in eastern Thailand and Mekong tributaries in Laos. It inhabits still and sluggish waters such as rice paddies, swamps and roadside ditches. It has been line-bred for aggression in eastern Thailand, and selectively bred and hybridised for the ornamental trade into colour forms that do not occur naturally. Wild populations vary in the extent of red or green patterning and are often labelled by locality.

Moderate