Things You Probably Didn't Know About Koi Fish

Koi Fish
One of the most popular pet fish, koi carp evolved from the common carp, which are natives to Asia. Here are some basic facts about koi fish.
PetPonder Staff
Last Updated: Jun 6, 2018
Koi Carp and Water Lily
The koi fish belong to the common carp species Cyprinus carpio, the origin of which, is believed to be from the Caspian and Black seas of Eastern Asia. The koi carp, which is one of the popular types of pet fish, are actually color variations of common carp.
The Japanese started breeding common carp for different color combinations, during the 1820s. Koi carp in different color combinations and patterns got popular, when they were presented in an exhibition in Tokyo, held in 1914.
Koi Fish
Now, we have various types of koi carp that differ in color, pattern and the type of scales. They are available in different colors including white, black, blue, red, yellow and cream.
Based on the color combinations and patterns of scaling, koi fish have been named as ghost koi, butterfly koi, goshiki, kohaku, taisho sanshoku and many more. They are very popular and are being sold across the globe, as a pet fish.
Caring for Koi Fish
Koi fish can be a colorful addition to your fish tank or pond. If properly taken care of, these fish may live up to 30 years and more. They have a very good lifespan and as per records, a koi fish raised by a Japanese family had lived for around 226 years! If you plan to raise these fish, you must have a basic understanding about how to take care of it.
Aquarium or Pond
White Koi Fishes In Black Pond
Whether it be a fish tank or a garden pond, it must be big enough to house fast-growing koi fish. For a full-grown one, you require at least 100 gallons of water.If you have ten such koi fish, your pond must have a capacity to contain 1000 gallons.
The attractive colors of Koi are found to be a disadvantage, as its predators like cats and kingfishers get attracted to the pond. Hence ponds should be made in such places, where it is difficult for these animals to invade. It is advisable to make koi ponds near shady trees to block the view of these predators.
Water Quality
Koi Fish In Japanese Garden
Koi fish thrive well in ponds that are at least 1.5 meters deep. Warm climate is very much suitable for these coldwater fish. They prefer a temperature range of 61 and 75 °F.
During winter, a pond with a good depth ensures that the water does not freeze solid. A regular dip of below 50 °F may sometimes pose a risk to the fish. During this period, do not feed them much, as their digestive systems slow down.
Stocking too much koi fish in a small pond or fish tank is not advisable, as this will affect the water quality. The pond must be provided with a pump and skimmer system. Don't opt for frequent water change in koi pond.
In case of fish tanks, you may go for water change once a month. Otherwise change one-third of the water, once in every three weeks. But, ensure that the tank has a good water filtration system. For koi fish, the ideal pH for water is between 6 to 9. Ensure that the water is clean and clear.
Feeding Them
Beautiful Koi Fish
Koi carp are omnivorous and they eat a wide range of food including bloodworms, algae, lettuce, peas and so on. You may feed them two to three times a day.
They eat very little in winter. When the temperature is too low, they should not be fed with protein as it may cause digestive problems. As the temperature soars, you may include protein-rich food that will help the fish to increase their fat reserves for the next winter. Young koi fish need more proteins, as compared to adults.
These fish can be trained to take food from the hand of the provider. They are also said to have a special ability to identify the person who is regularly providing them food. If the water conditions and feeding are proper, these fish can grow to a length of around 36 inches.
Breeding Them
Koi carps fish
Koi fish reproduce through spawning method where the female koi lays a large number of eggs which are fertilized by one or more male Koi. The parents are carefully chosen by the intelligent breeders, the resulting fry may have unimaginable colors.
A large number of fry may be defective or lack colors and so, they are destroyed by the breeder at various stages. With a careful investigation, a breeder with a good knowledge will be able to breed koi fish of different qualities.
Three grades of koi are popular: Pond grade - they are cheap and are bred by water gardeners; Ornamental grade - they are also inexpensive and they have attractive colors that decorate the place and Show grade - they are expensive, shiny and brightly colored and are mainly bred for shows.
The koi are priced on the basis of their size, color, pattern and type of scales. But it cannot be said that the biggest size always costs more. Generally, the size of the koi depends on size of the pond, food, temperature and oxygen supplies in the pond. Raising koi fish is an interesting hobby. But, you have to take proper care of them.
If you don't provide healthy food or if the water conditions are not proper, then, they will become sick. Monitor them regularly, so that you can prevent and/or treat health problems in your fish. Before buying your favorite koi, check for any infections or parasite disease. If you are planning to raise koi fish, you must gain a sound knowledge about them.