HomeFish encyclopediaRay-finned fishesCarpsMinnows or carpsLeast chub Least chub (Iotichthys phlegethontis) Scientific name: Iotichthys phlegethontis Cope, 1874 The Least chub (Iotichthys phlegethontis) is a freshwater fish of the family Cyprinidae. In the aquarium it needs water at 10–26°C (50–79°F). Native range: North America, Bonneville basin in northern Utah, USA. Least chub care at a glanceTemperature10–26°C (50–79°F) BiologyInhabits marshes, ponds, vegetated areas of streams and lakes, usually over mud.Source: FishBase, licensed CC BY-NC 4.0. Species factsScientific nameIotichthys phlegethontisFamilyCyprinidae (Minnows or carps)OrderCypriniformes (Carps)ClassActinopterygii (Ray-finned fishes)Maximum length6.4EnvironmentFreshwater; demersalClimateTemperateDistributionNorth America: Bonneville basin in northern Utah, USA.Conservation status (IUCN)Vulnerable (VU) (B1+2ac)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