Goldfish
Carassius auratus
Quick answer
The goldfish is a small freshwater fish in the carp family, domesticated in China over a thousand years ago and now the most popular pet fish in the world. Despite the myth of a three-second memory, goldfish can learn, recognize people, and remember things for months. In a proper aquarium or pond they commonly live 10 to 15 years, and some reach 20 or more.
Goldfish facts at a glance
| Scientific name | Carassius auratus |
|---|---|
| Diet | Omnivore |
| Habitat | Freshwater ponds and aquariums |
| Lifespan | 10–15 years, sometimes 20+ |
| Length | 10–20 cm (4–8 in), larger in ponds |
| Top speed | Slow; a gentle cruiser |
| Conservation status | Least Concern (IUCN) |
| Kingdom | Animalia |
|---|---|
| Phylum | Chordata |
| Class | Actinopterygii |
| Order | Cypriniformes |
| Family | Cyprinidae |
| Genus | Carassius |
Where it lives
Domesticated from wild carp in East Asia and now kept in ponds and aquariums worldwide.
Behavior and intelligence
Goldfish are social, curious fish that are far smarter than their reputation suggests. They can be trained to swim through hoops, recognize the person who feeds them, and remember routines for months rather than seconds. They are most active during the day and often beg for food at the surface.
Diet and feeding
Goldfish are omnivores that eat plants, algae, small insects, crustaceans, and prepared flake or pellet food. They have no true stomach and will keep eating as long as food is offered, so overfeeding is a common cause of illness. A varied diet keeps their color bright and digestion healthy.
Habitat and care
Domestic goldfish descend from wild carp native to East Asia and now live worldwide in aquariums and garden ponds. They produce a lot of waste and need much more space and filtration than the classic small bowl provides. In a spacious pond a single goldfish can grow well over 20 cm long.
As a pet
Goldfish are hardy, inexpensive, and tolerant of a wide range of temperatures, which makes them popular first pets. Their main needs are a large enough tank, good filtration, and clean water. Released goldfish can become invasive pests in the wild, so they should never be set free in lakes or rivers.
Frequently asked questions about the Goldfish
How long do goldfish live?
With proper care in a spacious tank or pond, goldfish commonly live 10 to 15 years, and some reach 20 years or more. Most goldfish die young from cramped bowls and poor water rather than old age.
Do goldfish really have a three-second memory?
No, that is a myth. Goldfish can remember things for weeks and months, learn simple tricks, and recognize the people who feed them, showing they have far better memories than the popular story claims.
What do goldfish eat?
Goldfish are omnivores that eat algae, plants, small insects, crustaceans, and commercial flakes or pellets. Because they will overeat, it is best to feed small amounts once or twice a day.
Are goldfish good pets?
Yes. Goldfish are hardy, long-lived, and easy to care for, which makes them good beginner pets, as long as they have a properly sized tank with filtration rather than a tiny bowl.
How big do goldfish get?
Most aquarium goldfish reach 10 to 20 cm (4 to 8 in), but in large ponds with plenty of room they can grow over 30 cm long and weigh several hundred grams.
Can goldfish live in a small bowl?
A small bowl is not suitable. Goldfish produce a lot of waste and need a large, filtered tank or pond to stay healthy; cramped bowls lead to stunted growth and short lives.
