Quick answer
Kois (Cyprinus rubrofuscus) are fishs found across Asia. The ornamental carp of garden ponds. Adults typically weigh roughly 5 kg (11 lb), reach speeds of Slow, steady swimmer, and live 25–35 years, sometimes much longer. They feed on omnivore and are listed as Least Concern on the IUCN Red List. Developed as an ornamental carp in Japan and kept in ponds worldwide; wild ancestors live in East Asian rivers and lakes.
Key takeaway
Kois (Cyprinus rubrofuscus) are fishs found across Asia. The ornamental carp of garden ponds. Adults typically weigh roughly 5 kg (11 lb), reach speeds of Slow, steady swimmer, and live 25–35 years, sometimes much longer. They feed on omnivore and are listed as Least Concern on the IUCN Red List. Developed as an ornamental carp in Japan and kept in ponds worldwide; wild ancestors live in East Asian rivers and lakes.
Koi overview
Koi (Cyprinus rubrofuscus) is a fish listed here as Least Concern. Typical weight about 5 kg; lifespan around 25–35 years, sometimes much longer.
Koi ecology
Diet: Omnivore. Habitat: Garden ponds; wild carp in rivers and lakes. Movement and social systems reflect those pressures across the native range.
Kois and people
Learn before you travel or keep related pets. Wild kois are not toys; captive care needs species-specific husbandry.
Status and further reading
Conservation label in our guides: Least Concern. See the full Koi profile for taxonomy, FAQs, and related topic guides on this site.
Range and habitat
Kois inhabit Developed as an ornamental carp in Japan and kept in ponds worldwide; wild ancestors live in East Asian rivers and lakes. Their preferred habitat includes garden ponds; wild carp in rivers and lakes, where they find food, shelter, and breeding sites. Population density varies with prey availability, water access, and human disturbance. Protected areas and intact corridors remain essential for long-term p
Physical characteristics and behaviour
Adult kois typically measure about 0.75 m in length and weigh roughly 5 kg (11 lb). They can sprint at Slow, steady swimmer when hunting or escaping predators. Kois are known for the ornamental carp of garden ponds — social structure, daily activity, and seasonal movements all reflect pressures in their native environment.
Sources
Koi FAQs
What are key facts about kois?
Kois (Cyprinus rubrofuscus) are fishs found across Asia. The ornamental carp of garden ponds. Adults typically weigh roughly 5 kg (11 lb), reach speeds of Slow, steady swimmer, and live 25–35 years, sometimes much longer. They feed on omnivore and are listed as Least Concern on the IUCN Red List. Developed as an ornamental carp in Japan and kept in ponds worldwide; wild ancestors live in East Asian rivers and lakes.
What is the scientific name of the koi?
Cyprinus rubrofuscus — used in research and conservation listings for kois.
What do kois eat?
Kois are described as omnivores, with seasonal and regional variation in Garden ponds; wild carp in rivers and lakes.
Where do kois live?
They are associated with Garden ponds; wild carp in rivers and lakes. Local presence depends on food, cover, and human land use.
What is the conservation status of kois?
Listed in our guides as Least Concern. Check the IUCN Red List and national assessments for the latest formal category.