HomeFreshwater aquarium fishGouramis & bettasSiamese fighting fish Siamese fighting fish (Betta splendens) Scientific name: Betta splendens Regan, 1910 The Siamese fighting fish (Betta splendens) is a freshwater fish of the family Osphronemidae that grows to about 6.5 cm (2.6 in). It is easy to keep and semi-aggressive, suits community aquariums and needs a tank of at least 20 L (5 US gal), water at 24–30°C (75–86°F) and a pH of 6.0–8.0. Native range: South Asia, Sluggish waters in Thailand. Siamese fighting fish care at a glanceCare levelEasyTemperamentSemi-aggressiveCommunity tankGoodAdult size6.5 cm (2.6 in)Minimum tank20 L (5 US gal)Temperature24–30°C (75–86°F)pH6.0–8.0Hardness5–19 dGH (89–339 ppm)DietOmnivore. Accepts flakes, frozen foods, live foods and vegetables. BiologyDorsal spines (total): 1; Vertebrae: 29 - 34. Reddish bars on opercle.Source: FishBase, licensed CC BY-NC 4.0. Species factsScientific nameBetta splendensFamilyOsphronemidae (Gouramies)OrderPerciformes (Perch-like fish)ClassActinopterygii (Ray-finned fishes)Maximum length6.5EnvironmentFreshwater;; pH range: 6.0 - 8.0; dH range: 5 - 19 benthopelagicClimateTropicalDistributionAsia: Mekong basin.Conservation status (IUCN)Not EvaluatedThreat to humansHarmlessUsesFisheries: of no interest; aquarium: highly commercialResilienceHigh, minimum population doubling time less than 15 months (tm More gouramis & bettasRoundtail paradisefishMacropodus opercularisCroaking gouramiTrichopsis vittataGiant gouramiOsphronemus goramyBetta albimarginataBetta coccinaPseudosphromenus dayiSee all gouramis & bettas Can it live with...?Siamese fighting fish and BadisSiamese fighting fish and Chocolate gouramiSiamese fighting fish and Crescent bettaSiamese fighting fish and Croaking gouramiSiamese fighting fish and Moonlight gouramiSiamese fighting fish and Ornate ctenopomaSiamese fighting fish and Pygmy gouramiSiamese fighting fish and Roundtail paradisefishSiamese fighting fish and Slim bettaSiamese fighting fish and Spotted bettaSiamese fighting fish and Spotted ctenopoma SourcesTaxonomy, distribution and biology data: FishBase (Froese, R. and D. Pauly, eds.), licensed CC BY-NC 4.0. Aquarium care parameters compiled, checked and converted to metric and imperial units by Guppies.za.net.Last updated 28 September 2026