What fish is also known as the Siamese fighting fish? Betta is the answer, specifically Betta splendens.
The Siamese fighting fish is a freshwater species native to Southeast Asia and is commonly sold simply as a betta. Its scientific name is Betta splendens, while “betta” can also refer more broadly to members of the Betta genus. In ordinary quiz usage, however, Betta is the canonical answer.
People in Thailand and nearby regions historically collected and bred these fish for their aggressive territorial behavior. Males were used in organized fighting matches and gambling, a tradition that helped shape the fish’s common name. Selective breeding later produced the vivid colors and elaborate fins familiar in aquariums.
Bettas are labyrinth fish: they can gulp air at the water’s surface using a specialized labyrinth organ. That adaptation helps them survive in warm, shallow, oxygen-poor habitats such as rice paddies and marshes. A common mistake is treating every Betta species as the Siamese fighting fish; the quiz specifically points to B. splendens.