2)Kuroko selection and sorting Hajime Isa
Selecting and sorting kuroko narrows down the 500,000~600,000 kego to 150,000~180,000~the whole month of June~
Hajime Isa

Kuroko selection and sorting is a special selection method used only for Kumonryu and Utsurimono like Showa.

There is a trait in Showa Sanshoku that if the fry’s body is not black at the kego stage, that Koi will not grow to be of good quality. So approximately one week after the eggs hatch, the kuroko are picked out. We breeders use large-sized Koi for spawning, so we get about 1kg (2.2 pounds) of eggs at one time. There are about 500,000~600,000 eggs in 1kg. We select and sort the kego when they measure 2~3mm (0.08~0.12 inches) long, which is about one week after hatching. Kuroko selection and sorting is not difficult. All you do is suck the entirely black kego with a narrow hose, so we ask the women and elderly in the neighborhood to help us.

About INPC
The life of Nishikigoi
  1) Spawning
  2) Kuroko selection and sorting
Koi Disease
Nishikigoi Mondo
Kuroko selection and sorting Kuroko selection and sorting
At this time of year in Niigata, you will see a great number of people, regardless of age or sex, selecting and sorting kuroko. One adult can pick out about 70,000 kuroko in one day. Even if six people work on one Koi, it takes a day and a half; 15 days would be needed to select and sort eggs from ten Koi. The number of kuroko that can be found at one time depends on the age or compatibly of the parent, but on average, it is about 30 percent. But this is only an overall average, and sometimes 50 percent of the eggs of one Koi are kuroko, or sometimes only less than 1% of them are. The remaining kego are put back into the field ponds after selection and sorting. They grow by mainly eating plankton and wait until the first selection and sorting to come.

*Kuroko: Black fry. Only Kuroko will be selected in culling Kumonryu and
Utsurimono like Showa.
*Kego: Fry. Koi babies (fry) that have just been born. At first, they are so thin they are nearly invisible, and they do not look like Koi. Depending on body color, they are called Akako (red fry), Kuroko (black fry) or Shiroko
(white fry).