The Siamese fighting fish (Betta splendens), also sometimes colloquially known as the betta, is a species in the gourami family which is popular as an aquarium fish. They are called pla-kad (biting fish) in Thai or trey krem in Khmer. They are aggressive towards their own species (females can group). However, they can be paired with other fish.This species is native to the Mekong basin of Laos, Cambodia, Vietnam and Thailand, the latter formerly known as Siam.