LEARN MORE ABOUT KOI FISH...

Learn more about Koi Fish….

In Japanese, Koi is a homophone for another word that means "affection" or "love"; and thus, Koi fish are symbols of love and friendship.

One could think that Koi fish are a version of goldfish but there are distinct differences. Goldfish were developed in China more than a thousand years ago by selectively breeding Prussian carp for color mutations favoring yellow, orange, white, and red-and-white colorations.  Goldfish were introduced to Japan in the 16th century and to Europe in the 17th century. Koi, on the other hand, were developed from common carp in Japan in the 1820s. Koi are domesticated common carp (Cyprinus carpio) that are selected and bred for color; they are not a different species, and will revert to the original coloration within a few generations if allowed to breed freely.

In general, goldfish tend to be smaller than koi, and have a greater variety of body shapes and fin and tail configurations. Koi varieties tend to have a common body shape, but have a greater variety of colors and color patterns. Some goldfish varieties, such as the common goldfish, comet goldfish, and shubunkin have body shapes and coloration that are similar to koi, and can be difficult to tell apart from koi when immature. Since goldfish and koi were developed from different species of carp, even though they can interbreed, their offspring are sterile.

Koi have prominent barbels on the lip that are not visible in goldfish. Koi fish are also called nishikigoi in Japan and it translates to what means literally "brocaded carp". Koi fish are domesticated common carp. Carp can be of a dull grey color, but there are some varieties that have bright ornamental colorings and are kept for decorative purposes in outdoor koi ponds or water gardens.

Historically, carp fish were originally found in Central Europe and Asia. In East Asia, various carp species were domesticated and used for food. Once they noticed the ability of carp to survive and adapt to many climates and water conditions, the domesticated species were propagated to many new locations, including Japan. More than a thousand years ago in China, they started to breed carp for their color mutations and size, and these breeding experiments led to the development of the common goldfish.

Koi varieties are distinguished by coloration, patterning, and their scales. While the possible colors are virtually limitless, some of the major colors are white, black, red, yellow, blue, and cream.

Koi also have several categories, the most popular category of koi is the Gosanke, which is made up of the Kohaku (red and white), Taisho Sanshoku, and Showa Sanshoku varieties. There are newer varieties such as the Ghost koi which was developed in the 1980s. Also in the 1980s the Butterfly koi also known as longfin koi, or dragon carp are quite popular for their long and flowing fins. Some koi enthusiasts criticize this overbreeding and don’t consider some varieties as not true nishikigoi. At the end of this blog I will list the most common names for the different varieties that are common today.

Koi fish are hardy and durabile. Koi are cold-water fish, but benefit from being kept in the 15-25 °C (59-77°F) range, and do not react well to long, cold, winter temperatures; their immune systems "turn off" below 10°C. Koi ponds usually have a meter or more of depth in areas of the world that become warm during the summer, whereas in areas that have harsher winters, ponds generally have a minimum of 1.5 meters (4½ feet).

Koi's bright colors put them at a severe disadvantage against predators; a white-skinned Koi is a visual dinner target against the dark green of a pond. Herons, kingfishers, otters, raccoons, cats, foxes, badgers and hedgehogs are all capable of emptying a pond of its fish. A well-designed outdoor pond will have areas too deep for herons to stand, overhangs high enough above the water that mammals cannot reach in, and shade trees overhead to block the view of aerial passers-by. It may prove necessary to string nets or wires above the surface. A well-kept pond usually includes a pump and filtration system to keep the water clear.

Koi are an omnivorous fish, and will eat a wide variety of foods, including peas, lettuce, and watermelon. Koi food is designed not only to be nutritionally balanced, but also to float so as to encourage them to come to the surface. When they are eating, it is possible to check koi for parasites and ulcers. Koi will recognize the persons feeding them and gather around them at feeding times. They can be trained to take food from one's hand. In the winter, their digestive systems slow nearly to a halt, and they eat very little, perhaps no more than nibbles of algae from the bottom. Care should be taken by hobbyists that proper oxygenation and off-gassing occurs over the winter months in small water ponds, so they do not perish. Their appetites will not come back until the water becomes warm in the spring. When the temperature drops below 50°F (10°C), feeding, particularly with protein, should stop or the food can spoil in their stomachs, causing sickness.

Koi can live up to 47 years old. There is a famous scarlet koi, named "Hanako", owned by several individuals, the last of whom was Dr. Komei Koshihara. Hanako was supposedly 226 years old upon her death in 1977.

Koi reproduce through spawning in which a female lays a vast number of eggs and one or more males fertilize them. Koi will produce thousands of offspring from a single spawning. Nurturing the resulting offspring (referred to as "fry") is a tricky and tedious job, usually done only by professionals. Although a koi breeder may carefully select the parents they wish based on their desired characteristics, the resulting fry will nonetheless exhibit a wide range of color and quality.

Here is a list of the major named varieties:

1.       Kohaku: White-skinned koi, with large red markings on the top

2.       Sanke, Taisho Sanshoku or Taisho Sanke: White skinned koi, with large red and small black markings called sumi

3.       Showa Sanke: Black skinned koi with red and white markings

4.       Tancho: any koi with a solitary red patch on its head

5.       Chagoi: Tea-colored koi coloration can range in color from pale olive-drab green or brown to copper or bronze and more recently, darker, subdued orange shades – famous for its docile, friendly personality and large size, it is considered a sign of good luck among koi keepers.

6.       Asagi: pale greenish koi known for its light blue color above and usually red below, but also occasionally pale yellow or cream, generally below the lateral line and on the cheeks

7.       Utsurimono: Zebra color pattern markings black koi with white, red, or yellow markings.

8.       Bekko: White, red, or yellow skinned koi with black markings, Shiro Bekko (white and black), Akka Bekko (red and black) and Ki Bekko (yellow and black)

9.       Goshiki:  is a dark koi where the base color can range from nearly black to very pale, sky blue and it has red patterns.

10.   Shusui : means "autumn green"; was created by crossing Japanese Asagi with German mirror carp. The fish has no scales, except for a single line of large mirror scales on its back, extending from head to tail. The most common type of Shūsui have a pale, sky-blue/gray color above the lateral line and red or orange (and very, very rarely bright yellow) below the lateral line and on the cheeks.

11.   Kinginrin: is a koi with metallic (glittering, metal-flake-appearing) scales. The name translates into English as "gold and silver scales"; it is often abbreviated to Ginrin. There are Ginrin versions of almost all other varieties of koi, and they are fashionable. Their sparkling, glittering scales contast to the smooth, even, metallic skin and scales seen in the Ogon varieties.

12.   Kawarimono: is a "catch-all" term for koi that cannot be put into one of the other categories. This is a competition category, and many new varieties of koi compete in this one category.

13.   Ogon: is a metallic koi of one color only. The most commonly encountered colors are gold, platinum, and orange. Cream specimens are very rare. Ogon compete in the Kawarimono category and the Japanese name means "gold.

14.   Kumonryu: This word literally means "nine tattooed dragons". The koi  is a black doitsu-scaled fish with curling white markings. The patterns are thought to be reminiscent of Japanese ink paintings of dragons. They famously change colour with the seasons.

15.   Ochiba:  is a light blue/gray koi with copper, bronze, or yellow (Kohaku-style) pattern, reminiscent of autumn leaves on water. The Japanese name means "fallen leaves".

16.   Koromo: is a white fish with a Kohaku-style pattern with blue or black-edged scales only over the head pattern. Hikari-moyomono (光模樣者?) is a koi with coloured markings over a metallic base or in two metallic colours.

17.   Kikokuryu: literally "sparkle" or "glitter black dragon" is a metallic-skinned version of the Kumonryu.

18.   Kin-Kikokuryu: literally "gold sparkle black dragon" or "gold glitter black dragon" is a metallic-skinned version of the Kumonryu with a Kohaku-style hi pattern.

19.   Ghost koi: Is a hybrid of Ogon and wild carp with metallic scales, is considered by some to be not nishikigoi.

20.   Butterfly koi is a hybrid of koi and Asian carp with long flowing fins. Various colorations depend on the koi stock used to cross. It also is considered by some to not be nishikigoi.

21.   Doitsu-goi:  originated by crossbreeding numerous different established varieties with "scaleless" German carp. The most common type has a row of scales beginning at the front of the dorsal fin and ending at the end of the dorsal fin (along both sides of the fin). The second type has a row of scales beginning where the head meets the shoulder and running the entire length of the fish (along both sides). The third type is the same as the second, with the addition of a line of (often quite large) scales running along the lateral line (along the side) of the fish, also referred to as "mirror koi". The fourth (and rarest) type is referred to as "armor koi" and are completely (or nearly) covered with very large scales that resemble plates of armor.  

Hope you enjoyed learning more about beautiful Koi…

Margarita Ochoa-Maya, MD