Goldfish
A domesticated carp selectively bred for color over a millennium.
Ry362 · CC BY-SA 3.0
The goldfish (Carassius auratus) is a freshwater fish in the family Cyprinidae, native to China and commonly kept as a pet in indoor aquariums. It is one of the most popular aquarium fish and has become an invasive pest in parts of North America and Australia when released into the wild.
- Largest recorded size
- 20.4 inches (52 cm) as of 2019 in Australia
Lore & Background
Goldfish were first selectively bred for color in imperial China more than 1,000 years ago, with distinct breeds developed over time.
Reader's Guide
Goldfish have been a significant model organism for studying vision and hearing in fish, possessing four kinds of cone cells (red, green, blue, ultraviolet) making them tetrachromats, and two otoliths with Weberian ossicles for sound detection. They are gregarious, display schooling behavior, and have strong associative and social learning abilities. Their ability to survive short periods of anoxic conditions is thought to be an adaptation to frozen water bodies over winter. The largest breeder in the late 19th and early 20th century was Henry Bishop of Baltimore, known as the 'Gold Fish King,' whose farms sold more than one million goldfish a year.
Did You Know?
- Goldfish have four kinds of cone cells, sensitive to red, green, blue, and ultraviolet light, making them tetrachromats.
- The largest goldfish on record measured 20.4 inches (52 cm) in Australia in 2019.
- Goldfish can hybridize with koi and common carp, and some of these hybrids can be fertile.
Gallery
Frequently Asked Questions
What is the goldfish and where does it come from?
The goldfish (Carassius auratus) is a freshwater member of the carp family, Cyprinidae, that originated in China. It is most commonly encountered today as a pet living in indoor home aquariums.
How big can a goldfish actually get?
The largest goldfish on record measured roughly 20.4 inches (52 cm) and was documented in Australia in 2019. Most aquarium-kept individuals stay well below that size.
Why is the goldfish so popular as a pet?
Humans have selectively bred this carp for over a thousand years to produce a wide palette of vivid coloration, making it visually striking in a tank. Its hardiness and relatively simple care needs have kept it among the most widely kept aquarium species.
What problem do goldfish cause in the wild?
When escaped or deliberately dumped pets establish feral populations in parts of North America and Australia, they outcompete native fish for food and habitat. This has earned the species a reputation as an invasive pest in those regions.
How long has the goldfish been a domesticated animal?
It is essentially a domesticated carp line that has been selectively bred for ornamental color for approximately a millennium. That extended history of human selection is what gives modern varieties their distinctive shapes and hues.
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