Betta fish, also known as Siamese fighting fish, are popular freshwater aquarium fish known for their vibrant colors and flowing fins. They are native to Southeast Asia, particularly in rice paddies and shallow waters. Betta fish are relatively small, typically growing to about 2.5 to 3 inches in length. They are known for their territorial behavior, especially males, which can become aggressive towards each other. These fish require specific care to thrive, including a warm water temperature between 76°F and 82°F and a tank with plenty of hiding spots. Betta fish are also known for their ability to breathe air through a specialized organ called the labyrinth organ, allowing them to survive in low-oxygen environments.