Koi Fry professional koi breeding

On hatching the fry are nothing more than a transparent sliver with eyes and a yolk sac, they are upright in the water. They feed off the yolk sac initially and their swim bladder gradually inflates so that within a day they are horizontal in the water and free swimming. At this satge the fry are about 7mm (0.28") long and are a pale yellow in colour. As the yolk sac is depleted they start to dart about looking for food. It is at this stage that they are carefully taken to the prepared mud ponds to feed on the infusoria, and grow on during the warm summer months. A few weeks after this the first cull ( something picked out from others, especially something rejected because of inferior quality) takes place. The mud ponds are harvested carefully using very large, fine nets, great care is taken so as not to damage the stock. Any fish that have deformities or those having poor colour, size and shape are culled, this can amount to about 80% of the stock. The ones that are already showing signs of developing into koi with good pattern and colour are kept back. At this stage of development they are about 1.25 cm (0.5") long, so you can see that it takes a very experienced person to spot potential at this time. When the fry are about 2.5 cm (1") long, usually by late July, a further cull takes place. Roughly 50% of the fry are kept back this time and their diet is supplemented with a powdered fry food which is placed in suspended baskets around the ponds. Towards the end of August a third cull takes place where approximately 60% of fry are retained and the rest destroyed. Now about 5 cm (2") long the babies are fed mainly on pelleted food. In late October when the fish are about 10 cm (4") long the mud ponds are harvested and the best Tosai (one year olds) make the final selection and are grown on over winter in the indoor pools. Up to 30% of the remainder may be destroyed and the rest are sold cheaply at auction. These are the ones that may be grown on in countries such as Thailand or Taiwan and then sold cheaply around the world advertised as Japanese bred koi. You can now understand why the quality of Japanes koi is so high, as each fish has had to survive four separate culls in order to make it through on merit.