A detailed guide to koi breeding methods: master the key breeding techniques

Most farmed koi are bred using artificial breeding methods, as this allows for a higher fertilization rate and hatching rate. So what are the breeding methods for koi?

1. Preparation before spawning

1. Isolation: Changing the environment is beneficial for mating, and artificial isolation is the most direct and convenient method. About 1 month before spawning, first isolate the male and female fish and keep them separately. When the breeding season approaches and the female fish shows abdominal swelling and the male fish develops “nuptial tubercles”, then place the female and male fish into the spawning pond.

2. Raise the water temperature: Appropriately raising the water temperature can promote spawning. Moving the brood fish into water that is 2——5°C higher than the original pond water temperature, or switching to a warmer environment, will prompt the parent fish to spawn. When the temperature reaches 25°C, koi become more active and prepare to spawn and breed. There should be ample sunlight during the day to raise the water temperature, and at night covers should be added (foam plastic boards and other insulation materials have good insulation performance) to maintain the water temperature.

3. Check the water quality: Check whether the pH (pH7.2—7.4) and oxygen levels of the water are suitable. Good water quality can promote spawning and improve the fertilization rate.

4. Administer reproduction-promoting hormones: Oral hormones or hormone injections are both acceptable, and vitamin E can also be used to promote reproduction.

5. Disinfection: 2-3 days before spawning, prepare the spawning pond and disinfect it. The palm tree bark, foxtail algae, spawning ropes, etc. used for the fish eggs to attach to must all be sterilized and disinfected. Prepare the water for the spawning pond; it can be tap water or groundwater, but it must be new water. It also needs aeration and dechlorination for one day or more before koi can be placed in it.

2. Start of spawning

1. After placing the male and female fish into the spawning pond, the female fish will swim continuously and rub her head against the spawning nest, while the male fish will rub against the female fish with its pectoral fins or head, forming a chasing behavior that promotes spawning.

2. Those attached to the spawning nest that appear white are dead eggs. Most eggs will be fertilized by sperm to become fertilized eggs, and a small portion of uncompleted eggs are called unfertilized eggs.

3. Completion of spawning

2. Once spawning is confirmed to be complete, slowly remove the parent fish. At this time the parent fish are quite weak and their resistance is quite low, so be careful not to injure them. Disinfect with potassium permanganate.

1. Soak the spawning nest with fertilized eggs in a malachite green solution (1 part per 10,000) for 10——15 minutes, or soak in a 5——7% test solution for 5 minutes, then place it back into another prepared hatching pond.

Although koi breeding methods are a bit troublesome, they are suitable and can effectively improve the fertilization rate and hatching rate, and the fry produced are of higher quality.