Koi breeding is not easy if what you aim for is to produce high-quality fish for competition purposes. Before you can have a prize-winning koi fish, you will have to cull and discard several thousand fry. The koi breeding process is long and difficult but it is all worth it.

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 type of offspring you're most likely to get. Just remember that the dominant genes are the ones from the male parent.

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

Male koi can start spawning upon reaching the age of two when small white nodules show up on the pectoral fins and gill plates. You can really feel those parts to be rougher than normal. You can make use of the younger males every two weeks but allow a longer time interval for older males to maximize their fertility potential.

Spawning

Koi will normally spawn in the early summer months. If you let that to happen, however, the eggs will only be consumed by the some other fish while the females get more anxious. The net result will be offspring of bad quality. Besides, a pond filled with eggs will harbor harmful bacteria that will adversely affect the health of your koi population.

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

During courtship, the male chases the female and forces her towards 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 know that the Koi have spawned if there is foam on the water surface and the distinct scent of ammonia. By then, you will need to transfer the female to a different pond where she can recover her strength. Remove the males too; or else, they could feed on the eggs.

Culling

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

Culling is essential in koi breeding. You need to reduce the numbers so the great quality fry can reach a decent size by the end of the season. If you do not cull, the undesirable koi will still fight with the good koi for food and space. Culled fry are normally destroyed or fed to the other fish.

You can release your selected young koi in a mud pond that is very rich in natural food. As they grow bigger, you can continue the selection procedure until you get only the ideal koi that you would like to keep or sell.