Goldfish facts for kids

Kids Encyclopedia Facts

Quick facts for kids Goldfish

Goldfish in an aquarium
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Actinopterygii
Order:	Cypriniformes
Family:	Cyprinidae
Genus:	Carassius
Species:	C. auratus (Linnaeus, 1758)

Goldfish (Carassius auratus) are a type of fish that people have raised as pets for a very long time. They are part of the carp family. Goldfish were first bred in China during the Tang Dynasty.

These amazing fish can grow quite large, sometimes up to 59 cm long and weigh 3 kg. But most pet goldfish usually stay about half that size. If they are well cared for, goldfish can live for up to 30 years! However, many goldfish in small aquariums don't live as long. This is because they need lots of space to swim and to keep their water clean. Goldfish like water temperatures between 10 and 30 degrees Celsius.

It was once thought that goldfish had very short memories. But scientists have shown this isn't true! In experiments, some goldfish learned to kick a small ball underwater. Another goldfish even learned to swim through a maze.

There are many different kinds of goldfish. The most common one is golden-colored. But goldfish come in many shapes, sizes, and colors. Some have beautiful, fancy tails. Another popular type is the black moor, which is black. Wild goldfish, called Prussian carp, are usually silver-green.

History of Goldfish
All About Goldfish
Goldfish Behavior
- What Do Goldfish Eat?
- Goldfish Reproduction
Different Kinds of Goldfish
Images for kids
See also

History of Goldfish

Three goldfish from Fish Swimming Amid Falling Flowers, a Song dynasty painting by Liu Cai (c.1080–1120)

A Ryukin goldfish from an old Japanese book.

For thousands of years, people in ancient China raised different kinds of carp as food. Some of these carp, which were usually gray or silver, sometimes had special red, orange, or yellow colors. The first time this was written down was during the Jin dynasty (265–420).

During the Tang Dynasty (618–907), it became popular to keep carp in special ponds and watergardens. A natural change in their genes made some carp turn gold (yellowish-orange) instead of silver. People started to breed these gold fish. They kept them in ponds. For special events, they would move the goldfish to smaller containers to show them off.

By the Song Dynasty (960–1279), people were very good at breeding goldfish. In 1162, the empress of the Song Dynasty even ordered a pond to be built just for red and gold goldfish. Around this time, only the imperial family was allowed to keep yellow goldfish. This was because yellow was the color of the emperor. This might be why there are more orange goldfish than yellow ones today. Other colors of goldfish were first seen in 1276.

A western aquarium from the 1850s, showing goldfish and other coldwater species.

During the Ming dynasty (1368–1644), people started keeping goldfish indoors. This allowed them to breed fish with new features that might not survive in outdoor ponds. The first goldfish with fancy tails were seen during the Ming dynasty. In 1603, goldfish arrived in Japan. Then, in 1611, they were brought to Portugal and from there to other parts of Europe.

In the 1620s, goldfish were very special in southern Europe. Their shiny scales were thought to bring good luck and fortune. It became a tradition for husbands to give their wives a goldfish on their first wedding anniversary. This was a symbol of good years to come. But this tradition didn't last long, as goldfish became more common and lost their special status. Goldfish first came to North America around 1850 and quickly became popular in the United States.

All About Goldfish

How Big Do Goldfish Get?

In 2008, the biggest goldfish known was thought to be 19 in (19 inches (48 cm)). It lived in the Netherlands. Another large goldfish named "Goldie" was a pet in England. It measured 15 in (15 inches (38 cm)) and weighed over 2 lb (2 pounds (0.91 kg)). In 2010, a goldfish measuring 16 in (16 inches (41 cm)) and weighing 5 lb (5 pounds (2.3 kg)) was caught in a pond in England. It was likely left there after growing too big for a tank.

Goldfish Vision

Goldfish have amazing eyesight! Their vision has been studied a lot by scientists. Goldfish have four types of special cells in their eyes called cone cells. These cells help them see different colors: red, green, blue, and even ultraviolet light. Because they can see four different primary colors, they are called tetrachromats.

Are Goldfish Smart?

Goldfish are very good at learning things, especially by connecting ideas or by watching others. They can also tell different humans apart just by looking at them. Goldfish owners often notice their fish get excited when they come near the tank. The fish might swim to the front, move quickly, or go to the surface looking for food. But they might hide when other people approach. Over time, goldfish learn that their owners mean food. They often "beg" for food when their owners are close.

If goldfish see humans often, they stop seeing them as a threat. After living in a tank for a few weeks or months, you might even be able to feed a goldfish by hand without it swimming away!

Goldfish can remember things for at least three months. They can also tell the difference between different shapes, colors, and sounds. With positive reinforcement (like giving them a reward), goldfish can be trained. They can learn to react to different colored lights or even do tricks. Fish often respond to certain colors when it's feeding time. They can also learn to expect food at the same time each day.

Goldfish Behavior

Goldfish are social fish. They often swim together in groups, which is called schooling. They also show similar ways of finding food. Goldfish might even act the same way when they see their own reflection in a mirror.

Goldfish have learned behaviors that come from their wild carp ancestors. They are a "generalist" species, meaning they can eat many different things, breed in various ways, and avoid predators well. This helps them survive. Goldfish are usually "friendly" towards each other. It's very rare for one goldfish to hurt another, even during breeding. The only real problem they have with each other is competing for food. Faster types of goldfish, like commons, can eat all the food before slower, fancier types can get to it. This can make the fancier fish grow slowly or even starve. So, it's best to keep goldfish types with similar body shapes and swimming abilities together.

What Do Goldfish Eat?

Various types of prepared fish food.

In the wild, goldfish eat small crustaceans, insects, and different plants. Like most fish, they will eat whenever they can and don't stop on their own. Giving them too much food can make them sick, often by blocking their intestines. This happens more often with fancy goldfish because their intestines are twisted. When there's too much food, they make more waste because they don't digest all the protein. You might see long trails of waste coming from the fish if they are overfed.

Special goldfish food has less protein and more carbohydrates than regular fish food. Some people also give their goldfish shelled peas (without the skin), blanched green leafy vegetables, and bloodworms. Young goldfish also benefit from eating brine shrimp. Just like with people, goldfish have their own favorite foods!

Goldfish Reproduction

Goldfish can only become old enough to breed if they have enough water and the right food. Most goldfish will breed in captivity, especially in ponds. Breeding usually happens after a big change in temperature, often in the spring. Male goldfish will chase females that are full of eggs. They bump and nudge the females to encourage them to release their eggs.

Goldfish, like all cyprinids, lay eggs. Their eggs are sticky and attach to water plants, like Cabomba or Elodea. The eggs usually hatch within 48 to 72 hours.

After about a week, the baby fish, called fry, start to look like tiny goldfish. But it can take a year for them to get their adult goldfish color. Until then, they are a metallic brown, just like their wild ancestors. In their first few weeks, the fry grow very quickly. This helps them survive because adult goldfish (and other fish or insects) might eat them.

Some very fancy goldfish can't breed naturally because their bodies have changed so much. There is a special way to help them breed called "hand stripping," but it can hurt the fish if not done correctly. In tanks, adult goldfish might also eat any young fish they find.