Oreoleuciscus angusticephalus
Oreoleuciscus angusticephalus, the narrow-headed Altai osman, is a species of freshwater ray-finned fish belonging to the family Leuciscidae, which contains the daces, chubs, true minnows and related species. It is endemic to Mongolia and has a maximum standard length of. Its young feed on plankton while adults feed predominantly on fish. It has a lifespan of over 40 years and takes 8–9 years to mature.