Koi carp (Cyprinus carpio Linnaeus) are a brightly coloured fish native to Asia and Europe. They are an ornamental variant of common carp (Cyprinus carpio carpio) and were developed by selective breeding from the Asian subspecies. Koi carp are one of the most popular ornamental pond fish in the world some colour variants sell for thousands of dollars (especially in Japan).
In the wild, koi carp keep their colour but not the forms that command high prices overseas. This ancient, beautiful and long-lived fish continues to fascinate and intrigue. Millions of dollars are spent each year on a few of the very best Koi specimens, and plenty of additional money is spent on the more common types.
Koi fun fact
Koi can live for many years. Though the average specimen in captivity might live 25 or 35 years, an old koi named Hanako, from Mino province in Japan, has been shown to be over 215 years old based on analysis of her scales, and other 100+ year old fish are known from the same pond. Koi, like wild carp, can grow to 36″ or more under perfect conditions.
Kois can get really old, and large
Koi carp can grow very large, given enough time and the right environment, potentially reaching over three feet in length! They are also fast growing, and will soon outgrow a pond that is too small for them, leading to potential health problems.
What to know about feeding aquarium fish
In nature, fish eat whenever they are hungry and the food is available. If food sources are plentiful, they will eat several times a day. On the other hand, if food sources are scarce, they might go for days between meals. For this reason, fish are very opportunistic and will eat whenever they have a chance.
Regardless of one or two feedings, the key is to keep each feeding very small. Do Not overfeed your fish. Whenever in doubt, the best practice is to underfeed your fish. There are a lot of health concerns related to overfeeding your fish.