Koi fish is a kind of ornamental fish, and it is also one of the most cultured ornamental fish in many families. The weather is getting warmer, and the breeding season in koi fish is coming. The breeding season in koi fish is from the end of April to the middle of June. So, what are the precautions for breeding in koi fish?

Koi fish belongs to Cyprinus and koi fish, and is called Nishikoi in Japan. It is a variation hybrid variety of carp, which is made by artificial breeding and hybridization for nearly 300 years due to the change of breeding environment. Its reproduction is similar to that of common carp, and it can reproduce naturally. But in order to obtain more high-quality products, koi fish often adopts artificial breeding.

First, the choice of parent fish

Parent fish for fry are generally selected, which are over 3 years old, over 60 cm in size, pure in blood, good in color and strong in physique. Generally, the male fish in koi fish can mature at about one and a half years old, but at this time, due to genetic instability, the quality rate of offspring is usually low, so it is difficult to obtain good fish. Therefore, if conditions permit, it is best to choose parent fish over three years old. Of course, it will get twice the result with half the effort if you choose good fish with excellent pedigree for breeding.

Second, the preparation of spawning pool

Preparing spawning ponds as spawning ponds generally adopts small cement ponds. The shape of the pool is not limited, and the scale is 4 meters high, 4 meters wide, 0.8 meters deep and 0.4 to 0.5 meters deep. The PH value of aquaculture water is 7.2-7.4, and it is better to use slightly salty and low-hardness water, and the dissolved oxygen in the water should be above 4 mg/L. Pay attention to the disinfection of the pond and put the fish nest prepared in advance into the pond. Fish nests are usually small bundles of Myriophyllum or palm trees Pi Zha soaked in water.

Third, intensive cultivation of parent fish.

Intensive breeding of parent fish should begin in autumn. At this time, the water temperature is about 25 degrees, and the fish has a strong appetite. Feed with protein content above 38% should be selected and fed at the rate of 8% of body weight, two or three times a day. At the same time, we should properly feed green feed, such as Chinese cabbage, spinach and duckweed. Increase the supply of vitamins, at the same time, appropriately increase starch in feed, such as rice and glutinous rice, and increase the accumulation of fat, which will promote the development of ovaries in spring.

Koi fish (Details)

Fourth, the breeding season

Spawning occurs in northern China, and the breeding season in koi fish is from late April to mid-June. When the water temperature rises to 16- 18℃? You can move the selected parent fish into spawning ponds, and put 2-3 groups of parent fish in each pond. After the parent fish entered the pool, when did they find that the parent fish were scrambling to chase each other? Indicates that spawning is coming. Generally, spawning begins around 4 am and ends around 10. Generally, it can lay 200,000-400,000 eggs at a time. The egg diameter in koi fish is generally 2. 1 to 2.6 mm. After the egg is laid, it absorbs water and expands, and the egg membrane is pulled out, so it will stick to the fish nest and hatch. After the parent fish lays eggs? Take out the fish nest containing fertilized eggs, soak them in 5%-7% salt water for 5 minutes for disinfection, then take out new fish and hatch them in the spawning pool.

Five, spawning water quality and water temperature

The water depth during hatching is generally 30 cm, and the requirements for water quality and temperature are the same as those during spawning. Incubation time is directly related to water temperature? Shorten with the increase of water temperature in the suitable water temperature range? 4-5 days when the water temperature is about 65438 08℃. 3-4 days at 20℃-22℃ and about 3 days at 25℃. The newly hatched larvae do not move or eat. Nutrition depends on absorbing the yolk sac in the abdomen. After the yolk is absorbed, the larvae begin to swim freely and eat the food outside. At this time, bait should be cast in time.

Six, natural reproduction

The water temperature is above 18 degrees, so it can be cultivated. When breeding naturally, prepare the fish nest. Aquatic plants, pine leaves, palm slices, nylon ropes, etc., which can usually be disinfected with permanganate A solution, are mainly used to achieve uniform adhesion of eggs. Tie the above items into small bundles and hang them on the water surface of the pool, which are evenly distributed at the bottom of the pool. The ratio of parent fish is generally one female and two males. 1: 1 is also acceptable if there are many parent fish. It is easiest to lay eggs in the morning in thunderstorm weather. Of course, with artificial flushing stimulation, the effect will be better.

Seven, artificial reproduction

Because koi fish is a hybrid strain, it is usually not easy to get good results by natural breeding. As far as species are concerned, more than 80 species of 13 can interbreed with each other, but their offspring are very complicated. In order to obtain excellent and beautiful offspring, we suggest that artificial breeding is better.

1, artificial natural propagation

Select the same parent fish with good quality and pure blood, put them in an independent clear water pool or cage according to the male-female ratio of 1: 2-3, hang fish nests on the water surface and let them lay eggs naturally.

2. Artificial dry insemination

Select the same parent fish with good quality and pedigree, and put them in an independent clear water pool or a cage with a fish nest according to the male-female ratio of 1: 2. When the chase begins to lay eggs, take out the female fish, anesthetize with anesthetic, dry the water on her body with a dry towel, gently press her abdomen, and put the extruded eggs in a small plate, paying attention to the fact that no water can be mixed in at this time.

Then catch the male fish in the same way, anesthetize with anesthetic, dry the water on the body with a dry towel, gently press the abdomen, suck out the semen with a straw, put the semen into the fish eggs, stir them evenly with chicken feathers or duck feathers, and then put them on the fish nest in the water after stirring them evenly. Be careful not to spread the eggs too tightly, but evenly. This process should be rapid and accurate.

Step 3 hatch

After the fertilized egg absorbs water, it can be soaked in malachite green solution for 5 minutes to prevent the invasion of water mold, and then hatched in clear water. It is best to add an air pump to make the water flow slightly, which is beneficial to the egg's breathing.

4, fry cultivation When the fry hatch, you can swim horizontally and start splashing egg yolk water. After feeding for 3 days, it can be transferred to the fry pond for culture.

Breeding in koi fish is not very complicated. Farming in koi fish is divided into natural farming and artificial farming. In order to obtain high-quality offspring from koi fish, artificial breeding still accounts for the majority, but it mainly depends on the breeder's own ideas.