A male Betta mahachaiensis, or Mahachai Betta, is a wild betta species from Thailand with an elongated, slender body and a brown to black body featuring iridescent blue-green scales and fins. Males are characterized by their vibrant coloration and more prominent fins, often sporting parallel red or green bars on their cheeks. These fish, adapted to brackish, coastal mangrove swamps, require hard, slightly brackish water and thrive in tanks with leaf litter and floating plants, and can be kept in planted community tanks.