HomeFish encyclopediaRay-finned fishesCarpsMinnows or carpsKyushu bitterling Kyushu bitterling (Rhodeus atremius) Scientific name: Rhodeus atremius Jordan & Thompson, 1914 The Kyushu bitterling (Rhodeus atremius) is a freshwater fish of the family Cyprinidae. In the aquarium it needs water at 10–25°C (50–77°F). Native range: Asia, Japan (Kyushu Island). Kyushu bitterling care at a glanceTemperature10–25°C (50–77°F) Species factsScientific nameRhodeus atremiusFamilyCyprinidae (Minnows or carps)OrderCypriniformes (Carps)ClassActinopterygii (Ray-finned fishes)Maximum length6.0EnvironmentFreshwater;; pH range: 6.8 - 7.8; dH range: ? - 20 benthopelagicClimateTemperateDistributionAsia: Japan (Kyushu Island).Threat to humansHarmlessResilienceHigh, minimum population doubling time less than 15 months (Preliminary K or Fecundity.) SourcesTaxonomy, distribution and biology data: FishBase (Froese, R. and D. Pauly, eds.), licensed CC BY-NC 4.0.Last updated 27 September 2026