One of more than sixty species of Betta, the Emerald-Green Betta, also called the Emerald Betta, is relatively uncommon in the aquarium trade. These fish are native to the slow-moving waters of rice paddies, swamps and ditches in northeastern Thailand. In their natural habitat, Betta fish must be equipped to survive in water that contains relatively low oxygen content. To surive in this environment, Emerald Bettas have a special organ called a labyrinth which enables the fish to breathe air at the surface of the water.