Betta imbellis has a pair of suprabranchial chambers that each house a labyrinth organ, a complex bony structure lined with thin, highly vascularised respiratory epithelium.

[4] Betta imbellis occurs naturally in Southern Thailand, Malaysia, and Indonesia, although it has been introduced to Singapore.

[5] Betta imbellis lives in sluggish bodies of water, including rice paddies, swamps, streams and ponds, with a substrate composed of leaf litter and mud.

In captivity, the species is fed live or frozen food like Daphnia, Artemia or bloodworms.

After mating, the male catches the falling eggs and places them in his bubble nest.