Koi breeding is difficult if what you want is to produce high-quality fish for competition purposes. Before you can obtain a prize-winning koi fish, you will have to cull and discard several thousand fry. The koi breeding process is lengthy and hard but it is worth it all.

Choosing the Parents

Choose the male and female from the exact same variety you want to reproduce. If you wish to cross-breed, choose varieties carefully and research more on the sort of offspring you're most likely to get. Just remember that the dominant genes are those from the male parent.

Make sure to use only matured fish for breeding purposes. The ideal breeding age of the female is from 5 years forward as their eggs are larger and much more fertile. Watch out for breeding females younger than 4 years old as your koi might lose their colors and patterns if bred at a young age. The female koi is ready to spawn if you find it sucking at the edges of the pond, aiming to clear an area where she can deposit her eggs.

Male koi can start spawning upon reaching the age of two when small white nodules appear on the pectoral fins as well as on the gill plates. You can really feel those areas to be rougher than usual. You can use the younger males every two weeks but allow a longer time interval for older males to make best use of their fertility potential.

Spawning

Koi will naturally spawn in the early summer months. If you let that to happen, however, the eggs will only be eaten by the some other fish while the females will be more stressed. The net result will be offspring of inferior quality. Moreover, a pond filled with eggs will harbor harmful bacteria that will negatively affect the health of your koi population.

If you are serious in koi breeding, you will need to use a controlled approach. Place the koi brooders in a separate pond and be sure to hang spawning media from the walls of the pond. The female will have them to place her eggs which can be somewhere between 100,000 to 500,000 depending on her mass. You can make use of ropes, artificial grasses, natural plants, vegetable sacking, or even cloth strips as spawning material.

During courtship, the male pursues the female and forces her against the walls of the pond to induce spawning. If there are two or even three males in the pond, they will crowd on her to simultaneously fertilize the eggs.

You will find out that the Koi have spawned when there is foam on the surface of the water and the unique scent of ammonia. By then, you will need to transfer the female to another pond where she can regain her strength. Remove the males too; otherwise, they might feed on the eggs.

Culling

The fry will break out of their eggshells within 5 to 7 days. They will keep on growing and you can start culling on the sixth week. Get rid of the baby koi with deformities like missing fins, deformed mouths, colorless, and also single color.

Culling is crucial in koi breeding. You need to reduce the numbers so the good quality fry can get to a decent size by the end of the season. If you don't cull, the unwanted koi will still fight with the good koi for food and space. Culled fry are usually destroyed or fed to the other fish.

You can release your selected young koi in a mud pond that is very rich in organic food. As they grow larger, you can resume the selection process until you get only the best koi that you would like to keep or sell.