Ricky Stoddart

The Difficulties of Predicting How Koi Will Grow

Identifying young koi with a potential for future growth is a subject that i'm hugely passionate about and approximately 10 years ago Fujio Oomo from Nishikigoi Niigata Direct (NND) shared his thoughts with me on that very topic.

In this piece, written personally by Fujio, he shares his thoughts about predicting the growth of koi from four months old.

I hope you enjoy the read.

The difficulties of prediction how 4 months old koi will be growing and developing for the next 7 months - Written by Fujio Oomo, NND

The Grow Out Contests are recently becoming more and more popular in many countries among koi hobbyists. This is why I took some example pictures how they have been changing for its over looking features during 7 months at their child age.

I have been wondering for the past a couple of years why many koi hobbyists would like to take part in this kind of very difficult and unpredictable events. Why they would like to challenge this kind of grow out contest?

I guess there are some reasons for the answers. The main reason is probably koi hobbyists would like to confirm their eyes whether their koi selection would make a point, right selection or lose a point, wrong selection. If the hobbyist would predict the koi future in the right way, he might think my appreciation of koi and my eyes to select koi was right. Eventually he can get a little more confidence for his own koi selection. On the other hand, if the selected koi does not grow better, he may think my eyes are not good enough to predict the koi growing in future. And another reason is simply they would like to see the change of development.

I think the ways of thinking of these two cases are both right. However, I think there is one more important point which I definitely have to take on is the freak of chance, in other words, I would say you have had 'Good luck' or 'Good fortune'.

As a conclusion for the success of Grow Out event for koi keepers, you have to brush up your eyes first and plus you have to bring 'Lady Luck' over to your side. These 2 main factors will lead you to the success of Grow Out event.

So at the Grow Out Contest, if your selection went wrong direction, you do not need to be reluctant too much, it was just unlucky this time. Just 'Lady luck was not with you' And hopefully Lady luck will be with you next time and you might get a very good result next time!!

I would like to show you some examples as follows:

Among many grow out contests, I think the contest supported by one dealer last October, 2010, might be the most difficult and challenge worthy contest, because the all the koi were just 4 months old koi(very young koi) and I guess probably nobody have never ever challenged it before.

So it might be a little too much works for the koi keepers, but worthy to try to step up their eyes and experience to higher level how to profound the dramatic change of body shape, development of sumi and many more.

Let me explain you about colour development by taking examples with the pictures. Who can predict the great change of sumi development and the development of red colour for these koi.

Let’s take a close look at sample pictures.

Sample pictures A and B: Showa

You can see how sumi has been developing overall of the body on both showa. You can see the Motoguro developing on the right side fin of A fish.

Sample A.png

Sample B.png

Sample pictures C and D: Sanke

Who could guess the percentage of sumi coming up for the next 7 months on these koi? If you could guess the right result when you see the 4 months old koi on the left side pictures, your eyes are really superb.

Sample C.png

Sample D.png

Sample pictures E and F: Sumi downing

The following examples are Sumi has been going down for 6 months, but Sumi might come up again in the future. No one can predict if sumi is coming up again or stay downing.

But I think these sumi is becoming sharper and clearly when they grow older.

Sample E.png

Sample F.png

Sample pictures G and H: Not much change to Sumi

The last examples are the koi has not been changing a lot for 6 months growing period in our growing indoor facility. As the koi grows older, the red colour is becoming deeper than before. But Sumi does not change a lot and just stay the same as before.

Sample G.png

Sample H.png

These explanation on the above, there are mainly 3 patterns .

  • Pattern 1: Sumi has been developed
  • Pattern 2: Sumi has been going down
  • Pattern 3: Sumi has just stay nearly as same as before.

For the growing rate, they mostly showed 20cm growth in 6 months period of contest. It means the rate of monthly growth was 3.3cm. The water temperature has been kept at 24 degrees during 6 months period. The indoor pond has 30 tons of water and 10 tons of filter system. 80 pcs of these size have been growing in the same pond. It mean one fish has 380 litter of water volume. It means approximately 2 fish for one ton of water. I feed 7 times a day. 5 times by auto-feeder and 2 times by hand feeding. I used 50% of Sakihikari high protein food and 50% of Sakihikari colour food.

Prize Winner for the contest:

Finally the result: 1st prize goes to Sanke (Sample I) 43cm as picture below: The picture on the left side was taken on 13th, Sep, 2010. and the size was 24cm on that day. The picture on the right side was taken on 4th, April, 2011 and the size was 43cm on that day.

Sample I.png

The 2nd prize goes to Showa (Sample J) 44cm as picture below The picture on the left side was taken on 13th, Sep, 2010. and the size was 24cm on that day. The picture on the right side was taken on 4th, April, 2011 and the size was 44cm on that day.

Sample J.png

All at last, I would like to explain it again that the real meaning of grow out contest is to have a good opportunity to learn how the sumi pattern has been developed through these period, how the depth of hi is becoming changing, how the white skin has been improved through these months and how the body-shape has been developed. Sometimes you might get the right selection by your right decision. And sometimes you might not get the right selection by your own decision. Sometimes disappointed. And sometimes, pleasing very much.

If you win or lose for Grow Out Contest, it is not a big matter at all. The more important point for all the participants is to learn how to profound the development and the potential of individual koi

I am hoping that Lady Luck will always on your side.

By the way, do you know who selected 'Sample fish A and Sample fish B' ? Honestly these 2 fish are the Champion Tategoi among 150 entry fish.

The answer is… “No one selected these 2 koi” I was very happy that “The Lady Luck” was with me. I thank you so much.

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