Koi, which are Japanese carp, are beautiful fish found most often in ponds in Japanese gardens.  Although they come in a number of different color variations, the bright orange and red are the most easily recognized.  Koi typically measure from 6 to 10 inches in length when they are young but as they mature, they can reach 20 feet or more.  This full-grown size usually takes about two years and watching them grow is an interesting process. 

Koi tend to be gentle fish that love to be handfed.  While most people will simply toss food pellets on the surface of the water, if you place pellets inside a closed fist and then carefully lower your hand into the water, the Koi will become curious and slowly start paying attention.  By releasing just a few pellets, the Koi will come even closer.  As you open your hand, the Koi will actually come right up to your hand and eat from it.  You will feel a strong sucking as the Koi inhale the food. 

The scales of Koi are shaped as diamonds with some having a metallic appearance.  Koi are amazingly beautiful and for being so large, very graceful.  The colors are always brilliant and the movement of the Koi, peaceful.  

Below are the various types of Koi:

• Asagi Shusui – This is a combination of two species with the Asagi representing scales with a white edge, giving the Koi a net-like look.  The belly is bright red, extending to the pectoral fins, gill covers, and lips.
• Bekko – This is a reference to any Koi that has two colors
• Goshiki – This name translates to “five colors” and consists of many different patterns of red, blue, black, white, and gray
• Hikari-Utsurimono – Predominantly black, the scales on this type of Koi are a very shiny metallic
• Koromo – Similar to the Asagi, the scales on this Koi have a darkened center, giving the fish a blue-like appearance
• Oringi Koi – This Koi is bright orange with non-metallic scales
• Ogon – Extremely shiny, this Koi can be yellow, gold, white, orange, or even platinum
• Showa-Sanshoku – This is a three-colored Koi that consists of white, red, and black
• Shusui – The scales of this Koi are smooth with orange that runs down the sides and on the cheeks, and the body is white with a blue streak.  For a Koi to fall into this category, the head must be white.
• Tancho – Of all the Koi species, this is the most interesting.  The fish is white and on the head is a perfect circle of red, making the fish look exactly like the flag of Japan.
• Taisho-Sanke – This Koi has three colors with black being the minor color.  To be a Taisho-Sanke Koi, the black must never be more than the color red.  Additionally, the head must be red and account for 50% or more of the head color.