Koi are a hardy fresh, cold water fish, that have the ability to survive on most of the continents of the world. Originally, the fish we now know as koi, developed from the common carp in China, where is was domesticated for a food source. Due to natural color mutations, historical records indicate that carp were first bred for color mutations in that country.
Because of the carp’s natural ability to survive under a variety of conditions, breeding the colorful variations in Japan started in the 1820′s. This is also where the koi name came from. It wasn’t until 1914, that the rest of the world became aware of the color variations of the carp, when the first were put on exhibition in Tokyo.
The hobby of keeping koi eventually spread worldwide.
Being omnivorous, koi will often eat a wide variety of foods, including watermelon, peas and lettuce. However, koi food is designed to not only be nutritious but also float, forcing the fish close to the surface, where they can be seen and admired. Also it is possible to check the fish for parasites and ulcers when they are eating close to the surface of the water.
Koi will often learn to recognize the person who regularly feeds them and will gather as close as the pond will allow them. They can even be trained to take food from the hand that feeds them. This makes the koi a very interesting pet to keep.
Their digestive system comes to nearly a halt and they eat very little during the winter. They may take small amounts of algae from the bottom of their pond, to sustain them, but their appetites will not return before the pond warms again in the spring warm weather. It is wise not to feed them after the temperatures drops below 10 °C (50 °F) because the proteins can go rancid in their stomachs, and cause them to become sick.
When koi are bought in a pet shop, they are generally quite small fry, often only the size of gold fish. Often they are bought by amateurs and placed in an aquarium. They can grow quite large relatively quickly and need space to live in. It is possible to increase the size of the aquarium to something in which they can live, but more often an outside pond is build for the fish. The pond usually includes a pump and filtration system to keep the water clear.
Koi are at a disadvantage when they are in a pond. Predators such as raccoons, cats, fox, badgers, heron and kingfishers are capable of catching these fish because the pond is not usually very deep and the fish are generally as bright as the owner can find. A well designed pond will have very deep areas that large birds cannot stand in, branches high enough that mammals cannot use to reach the pond, and shade trees so that birds flying overhead cannot see them. Some people string nets or wires above the surface.
Koi can be extremely long lived. The oldest known koi was a scarlet fish named “Hanako”, who had been owned by several individuals. Hanako was reported to be 226 years old upon her death. This was supported by tests that were done on one scale and examining it extensively in 1966. Hanako was born in 1751 and died July 7th, 1977. She is the oldest koi fish ever recorded.
Nice tips you got there!