All gouramis belong to the suborder Anabantoidei and are commonly known as the labyrinth fishes. These fish are characterized primarily by an accessory breathing organ called the labyrinth organ. The labyrinth organ is located next to the gill cavities and is made up of folded membranes mounted on a bony frame. The delicate tissue has a high concentration of blood vessels and func- tions much like a terrestrial lung. If a labyrinth fish is denied access to the air it will drown because the gills alone will not provide sufficient oxygen to the fish.