The Basics Of Hi Development

By: Brady Brandwood  - Lotus Land Koi Farm

Koi development can be a confusing topic particularly for folks just getting into the koi hobby. One of the reasons for this is that there are no "exacts" in koi. Another reason is a koi's colors can be easily changed by environment and diet. Several of my "Koi Pals" have purchased young Kohakus with truly red Hi from reputable koi dealers only to have the red fade to orange within two weeks of the sale. When this happens the orange color is generally the true color of the young koi at that time. It is simply immature orange based Hi. It is probably high quality Hi, but it is not ready to be red yet. Most, or at least many, young koi for sale by dealers are "colored up" or fed large amounts of color enhancing food, or forced into finishing early, to enhance the red. It is simple koi business. Orange koi don't sell in America when sitting in a blue tub beside koi with a rich bright red shade of Hi. So importers and dealers often make them more appealing by enhancing the red pigment. We do not do this at Lotus Land Koi Farm. We think it is important to know what you are actually buying. There are some young koi that have a purple based Hi that looks deep red even in very young koi, but in my experience purple based Hi does not last long. It tends to bleed around the edges where red meets white as the koi grows. Orange based Hi is high quality "elegant" Hi. It thickens and becomes red slowly over time, and it stays. Well finished orange based Hi on a jumbo koi is an incredibly beautiful thing to see.

As I mentioned in an earlier article "Understanding Basic Koi Development", with koi color development takes a back seat to growth, and a koi's growth takes a back seat to egg production. So, if a koi is growing quickly, as in a mud pond, or in a large sparsely populated koi pond, the koi's colors will be "down". The Hi will look thin and can be perceived as of low quality. Koi keepers in America run from this scrappy looking Hi at full speed. Don't be afraid of this! It's scary, but it is how koi develop. Photo (A) shows an example of the Hi of a growing koi. This is a 24 inch male Kohaku just out of a mud pond in October. When this koi's growth slows down the Hi will thicken and become the Hi we all desire.!

 Photo (B) is of the same  male Kohaku two years later, now 5 years old and 25 inches long. You can see how beautiful, glossy and thick the Hi looks now that it is  finishing. This koi was not fed any color enhancers at any point during it's growth. The Hi finished naturally to the shade and thickness it was destined to be. If you look at the growth figures  mentioned, you can see this Kohaku only grew an additional inch over  the past 2 years. It's growth was slowing down, so the koi's energy then went to color, and boy did it! The Hi began to thicken. Photos (C) & (D) show another example of a Showa (C) before the Hi matured,  and (D) after. We can see the shade of Hi has gone from orange to  red, and it looks much thicker and more solid. This happened naturally over a three year time period.t

It is my opinion that young koi should not be fed food high in color enhancers as they are growing because as they are developing we really need to know what stage of development they are in. When a person buys a "colored-up" fish with little information about the koi's  history they have no idea whether the koi is finished, or near  finished. It may not be your intention to buy a koi that is finished  at only 12 inches long. Knowing the koi's history, true age, and stage of Hi development will prevent this from happening, or it can help you choose a high quality small koi that will stay small, if that is your desire. If a koi's colors are "finished" at an early age the koi should be kept small to maintain this beauty. Tyring to grow a  small finished koi larger can cause the colors to fade away or break up. This is the reason a koi can generally not win Baby Grand  Champion and then later also win Grand Champion. It either looks good small, or it looks good large, but not both.

To identify a koi that is in a growing pattern look for a vertical slash of darker thick Hi in the center of each scale in the Hi pattern. See photos (E) & (F). This dark slash of Hi tells you the  koi is growing and the Hi will thicken in time, usually to the color  shade of this slash. With young koi under twelve months this may be hard to determine since the Hi is not even developed to this point yet. High quality young koi should have an even orangy shade of Hi.  Given this darker spot in the center of each scale indicates the koi  is still growing, you may see it on and off over the years as the koi goes in and out of growth spurts. If, for example, in the past two  seasons of harvesting I am not seeing the growth marks in the scales of a certain koi I know that koi has essentially stopped growing. So, now it is ready to be put into a pristine pond where the colors will now finish. This growth information is very important to determine when the koi will finish. This information helps the koi keeper form  a game plan for the koi's future. Understanding how Hi develops will better help you chart the course you want to take with your koi.

The Hi on a high quality koi will, or should, thicken up any time a  koi is put into a situation where the growth is restricted, or where the koi has reached it's adult size. Given this, we can see that a  koi can be forced or tricked into "finishing" by placing it in a small  or crowded pond where it has no room to grow. At this point size is  compromised for quick beauty. This is where patience comes into play.  Do you want your koi to be finished now? Or, would you prefer to let  your koi grow to it's full size before the colors are finished? This concept is the reason male koi may be a better choice for many koi keepers. A hobbyist who has a small pond and a lot of koi is never going to be able to grow a jumbo female koi out to her full potential, so the extra money spent on a female koi would be wasted since the  difference in price (size) between a male koi and a female koi could  never be realized.

I'm not concerned about the quality of the Hi on this Sanke (G) because I know her history and know she comes from a bloodline whos Hi  and white thicken very slowly. Ten years would be the average age of  maturity for this line of female Sanke. She is only five years old  and 68 cm, or 27 inches long. Given all this I feel very fortunate to have her in my pond. My job now is to be patient, give her a good environment, and let her develop at her own pace. When she stops growing in length she will begin to color up. If we compare this Sanke's Hi to the Hi of the female Showa in photo (H) we can see the  difference in finished and unfinished Hi. This Showa is 12 years old  and has finished developing in length and color. We see no growth  marks in her scales. The type and shade of her Hi and the shape of her body resemble that of a Sensuke bloodline Kohaku. Sensuke Kohakus  are known for their orange or persimmon shade of Hi, so we can see how knowing the history of this Showa or having a knowledge of bloodlines  can help us decide if we are going to like her in her finished state. The shade of her Hi is orange, but it is thick orange. Knowing she has Sensuke Kohaku in her blood I knew she would not be dark red when  finished. I believe orange works on her, another koi keeper may not.

If you come across a koi that you are thinking about buying, but the Hi looks thin, find out more about the koi. Ask the dealer for the history of the koi, in particular find out where it has been living  over the past year, and look for the growth marks in the center of  each scale. Has it been in a pond that would allow it to grow quickly? If it hasn't been growing very fast, and doesn't have the  growth marks in the center of each scale, it probably just has thin Hi  and this is undesirable for show fish.

A good simple way to understand how orange Hi becomes red Hi is to roll or brush red paint over a white surface, let it dry, then roll  another coat, and another. You will see as the paint thickens the shade of red becomes darker. With each coat of red you apply you are making it more difficult for the white base to show through. Naturally the shade of white on the base will affect how the red looks when it dries, as is the case with koi. The white on koi comes in many shades from a stark blue white to an eggshell yellowy white.

If we go back to the red paint on a white background analogy we find that it takes us longer to paint the many layers of red if we choose a  larger area to paint. Duh! What I'm getting at here is if we had two koi the same size, the koi with the larger Hi pattern will take longer to finish than the koi with the small Hi pattern.

The more we learn about koi the more we realize what an incredible accomplishment it was for the Japanese koi farmers to develop carp into what we see and keep today. If we look at how fast our society moves we can see how easy it is for us to become impatient with our koi. We've come to expect everything instantly. The time and patience it takes to develop and finish high quality koi are in direct  conflict with our fast paced lifestyles. Maybe we should try and  relax and move at their pace more often. Koi get beautiful slowly over time. Does that sound like an interesting concept, or what!