Koi Fish: Another Pond Pet

By Leslie Brown

Just looking at a koi pond can be easy on the eye and restful to the mind. It’s no wonder that the Japanese value koi so highly. Koi--and tattoos of koi--are traditionally considered lucky.

Keeping koi as pets is a hobby that has been gaining in popularity for the past 30 to 40 years, and the hobby has spread worldwide. Koi companions are long-lived, hardy, peace-loving, friendly, and they become a type of pet fish like no other. They will actually show a welcoming excitement as they see you walking towards them.

Koi fish are most treasured by the Japanese who have had a great respect and love for them for thousands of years. In Japanese, the word “koi” means “carp.” The ornamentation of koi fish is very similar to goldfish. However, koi and goldfish are different in that they were originally bred from a different species of carp.

There are 13 basic types of koi and over 100 varieties. Each koi is unique in color pattern, scale variation, and body shape. Some of the major colors are white, black, red, blue, green, yellow, purple and cream. Koi can also have a metallic sheen to their scales. Imported Japanese koi are admired for their intense colors and their differing scale variations. Part of the joy of keeping koi is watching them change color and size over the years.

Koi tend to grow the fastest during the first two years of its life. In the first year, a koi can grow to a length of 7 inches and reach 12 inches by the time it is 2-years old. By its third year, most koi will be about 16-inches long, which is far too large for most home aquariums. Some individual koi have been known to reach a length of over 5 feet. The lifespan for koi can exceed 40 years or more. After the first two years, a koi's growth will slow down, and it will not reach its full length until about 12 to 13 years later. A full grown koi can weigh up to 45 pounds.

Koi are a durable, cold-water fish. They can be kept in anything from small containers to large outdoor ponds. A pond should include a pump and filtration system to keep the water clear.

With their bright colors, koi can be at a disadvantage against predators, such as herons, kingfishers, raccoons, cats, foxes, and badgers. A well-designed outdoor pond will have areas that are too deep for herons to stand in, overhangs high enough above the water that mammals can't reach in, and shade trees to block the view of aerial passersby.

Koi are bottom-feeders, but koi food is designed to float so that it encourages them to come to the surface. They can even recognize the person feeding them, and often gather around at meal time. Koi can even be trained to take the food from your hand! A koi’s appetite is less in the winter, and it doesn’t come back until their water warms up in the spring.

Some koi fish cost a couple hundred dollars, while others can cost a couple hundred thousand dollars. If kept properly, koi can live about 30 years, with some known to live up to 200 years!

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