Siamese fighting fish, also known as bettas, are tropical freshwater fish native to the Indochinese peninsula, the region once known as Siam. In the wild, these often colorful fish generally prefer warm, shallow waters. As a domesticated tank fish, Siamese fighting fish are considered hardy and easy to care for as long as they are fed a live-food diet and given a warm-water environment. They can, however, attack other fish in the tank, especially if those fish are other Siamese fighting fish or other tropical fish with large, flowing fins, such as angelfish. These fish should always be given access to the surface of the water, since they have a special organ that allows them to breathe oxygen out of the air.
The Siamese fighting fish may be one of the most popular types of freshwater aquarium fish, especially for freshwater fish novices. These fish often come in bright, attractive colors including white, pink, red, blue, or purple. The typically betta fish reaches a size of about 3 inches (7 cm) in length, and may live for two to three years. These fish normally prefer a water temperature of 75 to 86 degrees Fahrenheit (24 to 30 C). Though many Siamese fighting fish are kept in very small containers, aquarium enthusiasts often stress that, ideally, each fish should be allowed a tank capacity of 2 to 3 gallons (7.5 to 11.4 liters).
In their natural habitat, Siamese fighting fish are adapted to life in shallow waters that aren’t disturbed by a strong current. Like other fish of the family Osphronemidae, betta fish generally possess a labyrinth organ. This organ allows the fish to breathe oxygen from the air, so that it can continue to thrive in waters that do not contain high levels of oxygen. Because the betta fish typically relies on its labyrinth organ to breathe, it should always be allowed access to the surface of the water in its tank or bowl.
These fish are considered meat-eating fish, and in the wild, they subsist largely on insects. Live food, including brine shrimp, glassworms, and plankton are most often recommended for betta fish. Frozen and freeze-dried foods may usually be safely substituted for live foods.
The Siamese fighting fish is generally believed to be an aggressive fish, and it has been known to attack other members of its species when kept in the same tank. Male betta fish are considered more aggressive than females. Because betta fish can be aggressive, aquarium enthusiasts must generally exercise care when selecting tank mates for this variety. It is generally considered inadvisable to keep a betta fish in the same tank with other bettas, but other species of tropical fish can thrive in the same tank as the betta, as long as they do not have long or large fins.