The Siamese fighting fish (Betta splendens), commonly known as the betta, is a freshwater fish native to Southeast Asia, namely Cambodia, Laos, Myanmar, Malaysia, Indonesia, Thailand, and Vietnam.It is one of 73 species of the genus Betta, but the only one eponymously called “betta”, owing to its global popularity as a pet; Betta splendens are among the most popular aquarium fish in the world, due to their diverse and colorful morphology and relatively low maintenance.