Believe it or not, the oldest documented koi on record was a Japanese koi named Hanako that lived to the ripe old age of 226 years.

Of course, Hanako was an extreme outlier. However, koi that are well cared for can regularly live to 20-30 years of age.

Unfortunately, koi and goldfish will eat aquatic plants that you may have in your pond. However, keeping your fish well fed with fish food will minimize the amount of plant material your koi will go after.

Absolutely! Both koi and goldfish are very docile creatures and will not harm each other in a pond or aquarium.

Koi can be more expensive than others of the same size because of many different factors, mainly color and pattern. The colors on a more expensive koi will tend to be deeper and more vibrant. A koi that has deep red or jet black will be more desirable than a koi with fading red or light grey spots. This can also apply to the pattern of color. The pattern must be evenly distributed throughout the body, without too much color concentrated on one end or side of the koi. Usually, an expensive koi, as compared to another the same size, will have a visually pleasing and balanced pattern, with deep, dark colors.

Koi tend to be more expensive than goldfish because of the extensive culling and selecting process. A single spawning will produce thousands of offspring that exhibit a wide variety of color, pattern, and quality. Separating the desirable koi from the less desirable is a tricky and tedious job.

Koi and goldfish may look similar, but the two are actually two different species. Goldfish were developed by selectively breeding Prussian carp for color mutations. Today, the goldfish is now considered an entirely new species from the Prussian carp. Koi were selectively bred from the common carp over many years to bring out certain colors and patterns. However, koi are still considered common carp and not a species of its own.
There are many ways to tell the two apart, but the easiest way is to look for “barbels” or “whiskers” near the mouth. Koi will have these barbels on the lips, while goldfish will not. Also, goldfish tend to be much smaller and exhibit more variety in body shape than koi. Koi tend to have a common body shape and have a greater variety of color and pattern.