HomeFreshwater aquarium fishBarbs, danios & rasborasPeamouth Peamouth (Mylocheilus caurinus) Scientific name: Mylocheilus caurinus Richardson, 1836 The Peamouth (Mylocheilus caurinus) is a freshwater fish of the family Cyprinidae. BiologyAdults form schools in lakes and slow-flowing areas of small and medium rivers. Most common around vegetation. Can withstand brackish waters for a limited period. Newly hatched individuals school near the shore, moving into deeper water in the summer. Feed mainly on aquatic insects and its larvae and some terrestrial insects; but also on planktonic crustaceans, mollusks, and small fishes. Preyed upon by fish-eating birds and mammals. Utilized as game fish and as food in the past.Source: FishBase, licensed CC BY-NC 4.0. Species factsScientific nameMylocheilus caurinusFamilyCyprinidae (Minnows or carps)OrderCypriniformes (Carps)ClassActinopterygii (Ray-finned fishes)Maximum length36.0Common length22.5EnvironmentFreshwater; brackish; demersalClimateTemperateDistributionNorth America: Nass (Pacific Slope) and Peace River (Arctic basin) systems in British Columbia, Canada south to Columbia River drainage in Oregon and Idaho, USA; also in Vancouver, Canada and other coastal Islands. Sometimes occurs at Spanish Banks.Conservation status (IUCN)Not EvaluatedThreat to humansHarmlessUsesAquarium: public aquariumsResilienceMedium, minimum population doubling time 1.4 - 4.4 years (tm=4) More barbs, danios & rasborasHypsibarbus wetmoreiGoldfishCarassius auratus auratusLambchop rasboraTrigonostigma espeiDanio erythromicronZebra danioDanio rerioWhite cloud mountain minnowTanichthys albonubesSee all barbs, danios & rasboras SourcesTaxonomy, distribution and biology data: FishBase (Froese, R. and D. Pauly, eds.), licensed CC BY-NC 4.0.Last updated 27 September 2026