Known by the scientific name Betta splendens, Siamese Fighting Fish are the most popular species of Betta in the aquarium trade. These fish are native to the rice paddies and shallow waters of Thailand, Laos, Cambodia and Vietnam. Siamese Fighting Fish are naturally fairly dull in coloration, but have been selectively bred to exhibit a variety of vibrant colors as well as various fin types. Popular fin types include crown tail, veil tail, halfmoon and round tail.