Siamese fighting fish

The Siamese fighting fish (Betta splendens) is one of the most widely recognized aquarium fish in the world, native to the shallow, sluggish waters of central Thailand including rice paddies, swamps, roadside ditches, and floodplain ponds. In nature it inhabits densely vegetated environments with low dissolved oxygen, an adaptation made possible by its labyrinth organ, which allows it to breathe atmospheric air. Wild specimens reach a standard length of 6-7 cm and exhibit subdued brownish-green coloration with short fins, a stark contrast to the elaborate, brilliantly coloured ornamental strains developed through centuries of selective breeding in Thailand and later worldwide. Modern domesticated varieties include Veiltail, Crowntail, Halfmoon, Plakat, and countless colour morphs. Despite their reputation for aggression — males are highly territorial and will fight to the death if housed together — Bettas can often be maintained alongside carefully chosen peaceful community fish in larger, well-planted aquaria. A tank with base dimensions of at least 45 × 30 cm (approximately 41 litres) is recommended for a single male or a pair. Contrary to popular misconception, they should not be kept in small jars or vases. As bubble nesters, males build and guard a nest of bubbles at the water surface, and the species is relatively easy to breed. The diet should include small live and frozen foods such as bloodworm and Daphnia alongside quality dried pellets.