Koi fish: Characteristics, history, types and more.... (2024)

Today you will know one of the most famous fish around the world: the koi fish that has inspired some legends and its image has a large number of symbolisms, among other things.

Koi fish are some of the most popular pond fish. Their long and powerful bodies are very similar to those of the wild carp.

The Kois’ physical appearance also resembles that of a common carpbut unlike these, the Koi has two barbs at the bottom of its mouth.

Koi fish often grow to lengths of more than 24 inches and are more suitable for outdoor ponds than aquariums.

Taxonomy🐠

Animalia Kingdom Phylum: ChordataClass: Actinopterygii Order: CypriniformesFamily: CyprinidaeGenus: CyprinusSpecies: C. carpio
(Linnaeus, 1758)

History .🐠

The name koi is an abbreviation of the Japanese word nishikigoi, which is made-up of “nishiki”, which means ‘something of beautiful colors’, and “goi”, which is the name that is applied in Japan to carps (common carps) in general.

Traditionally, it’s pointed out that the original development of koi carp may have occurred in China, starting from common carp specimens with spontaneous genetic mutations that appeared among those that were raised to serve as food in flooded terraces for rice cultivation.

These particular specimens were crossed with each other and selected to fix well-defined color lines.Another hypothesis is that they had a multiple origin, with contributions also from the lineage of wild carps native to Japan.

What is known is that the varieties of current kois present in their genetic heritage lineage of 3 or 4 subclades with continental origin. Even many varieties received contributions from the European carp, (having been imported from Germany to Japan) when the mirror carps were introduced to the island, to give kois a metallic look around 1904.

Another possibility is that the complete development of the kois has occurred in Japan, but based on mutant continental specimens that emerged in the Central Asian carp lineage.

What nobody argues is that it was in Japan where koi carps were perfected and for about two centuries, which means that almost all varieties are known worldwide for their Japanese name.

It’s believed that the first koi were transported to the Japanese archipelago in 1820, being taken to the prefecture of Niigata, in the cities of Ojiya and Nagaoka.

In that country they would reach great popularity after their exhibition at the annual Tokyo exhibition of 1914, which resulted in Emperor Hirohito introducing them to the Imperial Palace pond. The intensive production and selection of new varieties took strong momentum in the 1950s and, finally, from Japan they would be disseminated worldwide.

They have become very profitable commercially, paying for them really high amounts of even 100.000 dollars…

The Koi Fish’ Legend🐠

Popular mythology tells that a shoal of koi fish released a few in the Yellow River of China. The objective of each one of them was to challenge the channel until reaching a waterfall invaded by demons.

While everyone finally refused to overcome this last stretch, one last koi dared to try several jumps and reach the top. As a reward the gods transformed him into a dragon, a symbol of strength derived from the perseverance of a brave fish.

This is the reason why koi is a particular synonym of constancy and positivism in Chinese and Japanese cultures.

More koi fish symbols

According to other stories, the name of koi fish emerged around 500 B.C., after the delivery of a black carp that King Shoko de Ro made to Confucius as present.

Let’s watch it

The Koi Fish’ Main Characteristics.🐠

These striking fish have a life expectancy of about 30 years.Yet, it’s thought that some individuals have lived for even two centuries.

Koi fish have a robust body that becomes slender on the sides.

In addition, they have a tiny mouth, and their teeth are distributed in 3 rows.

The fin on their back is elongated and sunken, with its spine closed.

. Nishikigos have large scales; their hue is a greenish brown, with golden and bluish reflections and a whitish belly.

Finally, it’s recognized that a koi fish is healthy when it is not excessively energetic, nor passive in the extreme. We invite you to read our article the anatomy of fish to learn about such an interesting topic.

How much a Koi Fish Grows?🐠

Koi fish are quite large and with proper care, can measure between two and three feet long. The Koi Chagoi variety is even larger up to four feet long in some cases.

Young koi carp can be kept in large indoor aquariums, but they need to be transferred to a large pond as they grow.

This is a heavy body fish with an average weight of around 35 pounds, which makes necessary a big pond (500 to 1,000 gallons of water for every adult) for housing them.

It’s also necessary to point out, that kois need clean, high quality water in their ponds (which can be achieved using a filtration system designed for use in outdoor koi ponds).

When properly raised and cared for, a koi fish can live up to 20 years, and sometimes longer.

Curious Beliefs about Koi Fish:

• There is a belief that koi fish have the quality of distinguishing the face of their owner.
• They are very strong fish capable of traveling against the current.
• Koi fish have the ability to swim to the top of the waterfalls, where they was supposedly transformed into a dragon. Because of this legend, koi fish are associated with a long life, patience, strength and courage. For all this, their figure is among the favorites of many when choosing the symbol of a tattoo.

Are Koi Fish Edible?🐠

Chinese farmers originally bred koi for eating, and it wasn’t until the 1800s that the fish was bred as a pet due to its unique and striking colors.

Though they aren’t poisonous to eat, it’s advised that the types of koi that are kept as pets in water gardens or backyard ponds shouldn’t be eaten.

here they are

Koi Fish: Habitat and Distribution🐠

It originates from Asia and parts of Europe, although it has been taken to almost every continent. Koi fish inhabit stagnant or in fluid water.

It’s also very common to find it in many aquariums or ponds. It’s quite resistant and adaptable, withstands temperatures between 17 to 24ºC can live in fresh water like brackish.

Types of Koi fish🐠

Koi types are distinguished by their color, pattern and scaling. Some of the main colors are: white, black, red, yellow, blue and cream, even so, there are possible colors in the koi fish that are virtually unlimited.

Breeders have identified and named a series of specific categories, the most notable being Gosanke, which is made up of the Kohaku, Taisho Sanshoku and Showa Sanshoku varieties.

Let’s know fully about them

Kōhaku:🐠

Name in Japanese 紅白. It is a white-skinned koi, with large red marks on the top.

Their name means «red and white»; and this was the first ornamental variety that was established in Japan at the end of the 19th century.

Taishō Sanshoku:🐠

It is also known as Taisho Sanke and its name in Japanese is 大 正 三 色. This species is very similar to kohaku, except for the addition of small black marks called sumi. This variety was first exhibited in 1914 by the Koi breeder Gonzo Hiroi, during the reign of Emperor Taisho.

Tancho🐠

The Koi «Tancho» is one of the most popular varieties in the world due to its simplicity. It has an intense and pure White (Sumi) color that covers their entire body, with a red, circular (Hi / Aka) spot on the head, which makes it surprising and subtle.

This stain should not touch the eyes and should not pass the nostrils or shoulders. There are different forms of spots such as oval, square, heart, diamond, flower and cross, but these are not as appreciated as the circular spot. Within the Koi variety «Tancho» we find the following types:

• Tancho Goromo
• Tancho Goshiki
• Tancho Kohaku
• Tancho Kujaku
• Sanke Tancho

This species is very popular in Japan because its shape is very similar to the Japanese flag.

Let’s meet one of them

Kawarimono🐠

The class of Koi Fish «Kawarimono» is very wide because it includes all Kois Fish that don’t fit into any category, so the terminology of this variety os «All in one».

Within the Kawarimono Variety we find 14 different types of koi fish with a single characteristic: they don’t have metallic colors.

This class of Koi Fish is divided into 3 groups, one color, black and others. Many people consider this variety to be the “leftover” since here we find many Kois Fish that do not fall into any other category, but this doesn’t mean that within this variety we cannot find very beautiful Kois fish.

• Ochiba Shigure
• Kumonryu
• Beni Kumonryu
• Benigoi
• Karasugoi
• Haijiro
• Aka Haijiro
• Chagoi
• Kigoi
• Midorigoi
• Soragoi

Hikarimono (Ogon)🐠

The «Hikarimono» are single-colored Koi fish whose scales and skin shine, which makes them been known as “metallic”. . Their head should be of a lighter hue than the rest of their body, but it should not lose its brightness, which should be extended by the fins, mainly by the pectoral fins.

The quality of the color and the shape or design of the scales is fundamental in this species, since when presenting some stain both on the skin and on the scales, it would be highly visible, greatly devaluing its value.

. The variations of “Hikarimono” Koi fishs depend on the colors:

• Nezu Ogon
• Orenji Ogon
• Platinum Ogon
• Yamabuki Ogon

The Koi «Ogon» are very sought after by fans, and this not only happens because of their beauty, but also because they are very visible in the pond, as well as are very intelligent and can reach large sizes.

Goromo🐠

In the “Koromo” variety, the Koi Fish has black shading on its spots or color patterns. This species was available since the fifties and was generated through the cross between a female Koi Narumi Carp Asagi and a male Kohaku Carp.

Depending on the colors of the patterns we can find the following types of Koi Goromo fish:

• Ai Goromo
• Budo Goromo
• Sumi Goromo
• Goshiki

Hikarimoyo🐠

The word «Hikari» means «Metallic» and within this variety «Hikarimoyo» enter all types of Koi fish that have two or more metallic colors.

Many types of Hikarimoyo were formed by crossing different «Hikarimono».

The Hikarimoyo Kois have a metallic skin and scales with strong color patterns giving them a unique beauty. This variety is subdivided into:

• Kin Showa
• Kujaku
• Yamato Nishiki
• Doitsu Hariwake
• Kikusui

here they are

Matsuba🐠

The Koi Fish «Matsuba» has a solid color whose scales have a black pattern as if it were a shadow, thus giving it a net-like design.

The colors may be metallic or not, but mostly these Koi Matsuba are brightly colored.

The head must be free of any stain or black mark, and its base color may vary, within which we find white, yellow and red.

• Shiro M

• Aka Matsuba

Bekko🐠

The Koi Fish «Bekko» is characterized by having solid colors with black spots. The base colors of this fish can be three, Red (Aka), White (Shiro) and Yellow (Ki), the latter being very difficult to achieve today.

The spots should be an intense black color (such as carbon) and should be balanced symmetrically on the upper part of the Koi Fish’s body, the head should be clean without spots, while the fins may have some. Within the «Bekko» variety we find three types of Kois Fish:

• Shiro bekko
• Ki Bekko
• Aka Bekko

The «Bekko» is generally the first variety of Japanese Fish that beginner fans recognize, as well as being highly sought after for their Garden Ponds.

here they are

Utsurimono🐠

This type of Japanese carp «Utsurimono» is characterized by having the color Black (Sumi) as a base with spots of White (Shiro) or Red (Hi / Aka) or Yellow (Ki).

This species is commonly confused with the «Bekko» variety. So that this does not happen we must pay attention in detail to the colors. The deepest color will be taken as the basis, in this case it should be the color Black (Sumi).

Another characteristic of this species of Koi is the appearance of «Motoguro» …, which is a solid black spot (Sumi) that appears on the pectoral fins of the fish, starting at the joint of the fish (attached to the body of the Koi ) and extends to about half of the fin.

The other species presents the «Motoguro» is the variety «Showa».

Within the species «Utsurimono» we find three types of Japanese carp:

• Shiro Utsuri
• Ki Utsuri
• Hi Utsuri

The spots of this Koi Fish are similar to the spots of inks, so the term «Utsuri» means «Print» in Japanese

Asagi

The Koi Carps «Asagi» are one of the oldest and most beautiful races of the Nishikigoi. Within this variety of Koi Fish we also find the Koi Carp “Shusui”

• Asagi
• Shusui

Let’s watch

Koi Fish: Care and Longevity🐠

Keys in caring koi fish

Pond water

The water where the koi fish lives must be kept in optimal conditions and be of the highest quality. Getting it will help us in its good maintenance.

In addition, the pond must have a good filtration system and high oxygen content. An option to keep the water with a high oxygen content is with the installation of a waterfall in the pond, which will generally be covered with algae and plants that are, in turn, a natural filter for fish.

Temperature

The koi fish is a cold water fish, and that means it can withstand cold temperatures.

Ideally, we should keep our pond at a stable temperature throughout the year, ranging from 18ºC to 25ºC.

Diet

Feeding is essential in the care of koi fish and we will provide them with the right amount of food they are able to digest in a few minutes.

We can differentiate two feeding periods if a heating system is not maintained in the pond. If the pond lacks this system, the koi will winter and it is not advisable to provide food since they won’t digest it.

At the moment when the water temperature exceeds 7ºC we will begin to feed them again progressively.

In the case that the pond keeps its temperature stable in winter, thanks to the heating system installed, the diet must varied and can be complemented with fresh vegetables.

Keep in mind that the koi fish will eat any type of green plant, so we must take care of the type of decoration that is put in the pond. One way to prevent koi from killing all the plants in the pond is to grow aquatic lentils that will be eaten by them.

We invite you to read our article decorating aquariums to….

Can koi live with other fish?🐠

Koi are docile and social fish that enjoy living as a couple or in a group. When considering whether or not to add a new fish to an existing habitat, always ensure that its environmental and nutritional needs are the same as those of current fish.

Moreover, in the case of adding a koi fish to an existing pond, make sure that the size of your pond is large enough to house an adult koi.

In addition, it’s very important to point out that koi are very friendly and do not eat other fish or fight among themselves.

If you are mixing species, make sure the same can be said of the other types of fish in your pond before adding koi.

Not only are they friendly with other fish, but they can also surface when they see their owner or when it’s time to eat. Some koi even like to be pets and come to the surface by a small pat on the head.

Final Consideration

Smaller fish can be an easy target for a hungry adult koi. Smaller fish won’t be able to resist a koi attack. In addition, koi fish have a big mouth through which a smaller fish can easily pass when it sucks water to eat or breathe.

Smaller fish that Koi will eat

• Danios
• Guppies
• Little fish
• Siamese seaweed eater
• Small medium fish that Koi may or may not eat
• Barb
• Fancy goldfish
• Juvenile fish
• Mollies
• Small catfish

Fish Koi won’t eat

Medium and large size fish are excellent pond mates for koi. There is a wide range of fish species that can be housed with koi in a garden or aquarium pond. But these are the best fish to house with koi:

• Gold orfe
• Tench
• Barbel
• Sturgeon
• Pleco

Keeping koi fish safe

One thing to keep in mind is the safety of your koi, especially because they are known as notorious jumpers. Usually, when they jump out of the water, they re-enter and remain safe, but sometimes they simply jump out of the water and if left unattended, they will surely die.

The other thing you should know is that predators stalk prey. You should consider installing a protective fence and bird nets to keep the koi safe at all times.

With these tips in mind, your koi fish will be happy and stay healthy, while reaching their full potential. Good luck and happy koi!

Here they are again

Learning about Common Carps🐠

The Common Carp (Cyprinus carpio) originates from the European and Asian continents. It’s one of the most resistant freshwater fish and that best suits the place where it lives, that is why it has managed to conquer virtually every corner of the planet and has earned the «privilege» to enter the list of the 100 most invasive alien species according to the International Union for Conservation of Nature.

Adult specimens typically reach a length ranging from 60 to 90 centimeters, and a weight of around 9 kilograms.

It’s estimated that some specimens, if they enjoy certain conditions during their lifetime, can reach 1.2 meters and weigh 40 Kg, and exceed 60 years of age, almost nothing!

They would also survive in stagnant, low brackish waters as long as they are in a temperature range between 17 and 24 oC.

Common Carps are mainly omnivorous, and their diet consists of aquatic plants, insects, small crustaceans, etc. The breeding season begins in spring, and takes place in shallow, dense waters in vegetation.

Females get to lay up to 300,000 eggs that, depending on the water temperature, can hatch after 3-4 days.Both males and females reach sexual maturity at 4 years of age. We invite you to read our article goldfish to learn aboutcyprinids species….

Let’s watch and learn