Betta
Published
The betta, or Siamese fighting fish, is one of the most striking fish anyone can keep: a small body trailing huge fins in red, blue, white, black or all of them at once. It is also a fish with a long history alongside people.
From rice paddies to show tanks
Wild bettas live in shallow, still and often warm water in Southeast Asia: rice paddies, marshes, floodplains and slow streams in the basins of the Chao Phraya and Mekong rivers. The wild fish is short-finned and fairly dull, turning bright only when two males face off. People in what is now Thailand were breeding them for fighting contests for centuries, and later for colour and fins. Today the wild species is listed as vulnerable, while domestic bettas are bred in huge numbers.
Colours and fins
Selective breeding has produced an enormous range of forms. Fin types include the veiltail (the classic pet-shop betta), the halfmoon, whose tail spreads into a full half circle, the spiky crowntail, the rosetail with extra-branched fins, and the short-finned plakat, closest to the old fighting fish. Colours range from solid red, blue, turquoise and white to near-black, and the "koi" and "marble" bettas carry a gene that makes their pattern change over their lifetime.
Breathing air, building nests
Bettas have a labyrinth organ, a folded chamber above the gills that lets them breathe air from the surface. It is how they survive in warm water with little oxygen. A male ready to breed blows a raft of bubbles at the surface. After spawning, he catches the sinking eggs in his mouth, spits them into the nest and guards them — and later the fry — alone, chasing the female away.
Keeping bettas
The labyrinth organ does not mean a betta can live in a bowl. It needs a heated, filtered tank with a gentle current, since long fins struggle against strong flow, a lid with a little air gap, and plants with broad leaves to rest on near the surface. Never keep two males together — they fight, often to the death. A male can share a larger tank with small, calm fish that do not nip fins or look like another betta.