Facts About Goldfish

By PetMD Editorial on Feb. 11, 2016

By Kali Wyrosdic

When most people think of goldfish, they don’t realize that this common pet has a rather noble history. Goldfish as we know them today are all descendants of the Prussian carp, native to eastern and southeastern Asia, and look nothing like their dull-colored ancestors. Keep reading to learn all about goldfish then and now, plus some fun goldfish trivia.

A History of the Goldfish

It was during the Song Dynasty (960 AD – 1279 AD) in ancient China that people started to breed silver-colored carp. Once breeding began, a color mutation appeared, resulting in yellow-orange scales. Yellow was designated the imperial color and forbidden to be kept by anyone other than members of the royal family. Commoners had to stick to the orange version, calling them goldfish.

In ancient China it was common to raise goldfish in outdoor ponds and water gardens, which people still do today. On special occasions, or when there was an exceptionally beautiful specimen, goldfish were placed on display indoors in small containers. During the Ming Dynasty around 1276 AD, goldfish were officially bred and brought indoors, achieving red, gold, spotted and other colored fish. Additionally, the fancy-tailed goldfish began to make an appearance.

Where Do Pet Store Goldfish Come From?

These days, goldfish come in all shapes, sizes, fin styles, eye setting configurations and colors. Most goldfish that you see in pet stores come from commercial breeders, usually located in Thailand, Japan, China or Indonesia. While commercial goldfish are yellow, gold and lot of other colors, wild goldfish are almost exclusively olive green or dark grey. Commercial goldfish are suited for indoor living only, but there are species of pond goldfish that thrive in outdoor water gardens and ponds and can grow much larger.

Goldfish are the most popular pet fish and can be found at pet stores around the country. On average, depending on the colors and type, you’ll pay anywhere from a few dollars to upwards of $15 for a pet goldfish. The most expensive goldfish breed, however, is the Ranchu goldfish, which costs about $150 depending on its size and color.

How Big to Goldfish Get?

Common goldfish (the ones that you can win at county fairs), are actually one of the largest species of goldfish, capable of reaching lengths over 18 inches and weighing up to ten pounds. Even the smallest goldfish species reach adult lengths between four and seven inches and are best suited for 20-gallon or larger aquariums, not fish bowls. The size of your goldfish’s tank will affect its growth to an extent, but there are other factors to consider, like the fish’s diet and cleanliness of its environment. Depending on the species and above-mentioned factors, a goldfish can end up being two feet long or as small as two inches.

What do Goldfish Eat and How Long do They Live?

In the wild, goldfish are omnivores, eating aquatic vegetation, frogs, newts, fish eggs and insect larvae. Pet goldfish do well with pellet fish food supplemented with vegetables, but some fancier varieties may require a decent amount of live food in their diet or they run the risk of developing intestinal problems.

Despite the popular myth that goldfish die quite young, goldfish are one of the longest-living fishes out there, with the oldest recorded living goldfish reaching the age of 49. The main reason why so many goldfish die young is that they aren’t kept in the proper conditions. On average, goldfish kept in a bowl have the shortest lifespan at about five years. Goldfish living indoors in an aquarium can live up to ten years, while those kept outdoors in a water garden or pond can live at least 20 years, sometimes up to 30 or 40 years.

What Makes a Good Goldfish Habitat?

In the wild, goldfish prefer freshwater, particularly slow-moving, calm water. Goldfish have also shown preference to thick and muddy water, and cloudy or dense water doesn’t trouble them at all. In other areas, goldfish populations have been found happily living in stagnant backwaters, where they feast on the ample aquatic plant life. An ideal goldfish home will also have zooplankton, fish eggs, insect larvae, detritus and crustaceans roaming around for the fish to feast on. Goldfish also prefer cooler waters, and for this reason shouldn’t be kept in tropical aquariums. Another thing to keep in mind if you want a pet goldfish is that they require twice the amount of space that tropical fish require, so don’t overload your tank.

Are Goldfish Edible?

Goldfish are descendant of carp, which used to be raised for food in ancient Asia. Carp are still the premiere game fish in Europe and considered the most valuable food fish in Asia. That being said, carp isn’t used as a food fish in the United States because it’s extremely tough, bony and greasy. Plus pet fish can carry disease; any other fish makes a better, more filling and healthier meal.

More Fun Facts About Goldfish

Here are a few more bits of goldfish trivia to impress your friends with:

  • Goldfish live and sleep with their eyes open. In fact, they don’t have eyelids so they can’t close their eyes even if they wanted to.
  • Goldfish were once believed to be good luck and it was tradition for newly married men to give one to their wives on the first wedding anniversary.
  • Despite common belief, goldfish do not have three-second memories. They can actually remember things that happened up to three months ago – sometimes more.
  • Goldfish have a sense of routine and can be trained to do small tricks like swimming through hoops and pulling levers to release food.
  • A group of goldfish is called “a troubling,” not a school. 

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