Koi (definite introduction)
Koi is a kind of guinea fish and is also used in many families. One of the most popular koi fish, the weather is getting warmer, and the growth season of koi is coming soon. The growth season of koi is from the end of April to mid-June. So, what are the important things to pay attention to when growing koi? ?
Koi carp belongs to the genus Cyprinus of the family Cyprinidae (Carpio) and koi carp (Brocarded Carp). It was originally called Nishki Goi in Japan. It is a mutated hybrid species of carp. It was developed after nearly 300 years of artificial selection and hybridization due to the gradual change in body color caused by changes in the breeding environment. Its growth is similar to that of ordinary carp and can grow naturally. However, in order to win more high-quality products, artificial growth is often used to grow koi.
1. Selection of broodstock
Broodstock used for dry breeding are generally chosen to be over 3 years old, some are over 60 centimeters in height, with pure bloodline and unique color quality. Out, those with a prosperous constitution are better. Generally, male koi fish can mature at one year old, and female fish can mature at one and a half years old. However, due to genetic instability at this time, the quality rate of the offspring produced is often relatively low, and it is not easy to obtain good fish. Therefore, if conditions permit, , it is best to choose dried broodstock fish above 3 years old. Naturally, if you use the best fish species with special bloodlines to grow, you will get twice the result with half the effort.
2. Preparation of the spawning pool
The preparation of the spawning pool as the spawning pool generally uses a small cement pool. The shape of the pool is not limited, and the size is 4 meters high, 4 meters wide, 0.8 meters deep, and the water depth is 0.4 to 0.5 meters. The pH value of growing water is 7.2-7.4. Water quality with brackishness and low hardness is better. Dissolved oxygen in water should be kept above 4 mg/L. Note that the pond water is disinfected and the pre-made fish nests are placed in the pond in advance. The fish nests are generally made of steamed and soaked foxtail algae or brown bark tied into small bundles and dried.
3. Enhanced cultivation of broodstock
The enhanced cultivation of broodstock should start in autumn. At this time, the water temperature is around 25 degrees, and the fish's appetite is strong. Feed with a protein content of more than 38% should be used at a rate of 8% of the body weight, two to three times a day, and appropriate amounts of green feed should be fed at the same time. , such as vegetables, spinach, duckweed, etc., to increase the supply of vitamins. At the same time, it is appropriate to add starches, such as rice, glutinous rice, etc., in the feed to reduceLess fat accumulation will be useful in promoting ovarian development in spring.
Koi (confirm introduction)
4. The growing season
The spawning season is in the Shuofang area of our country. From late April to mid-June is the growing season for koi. When the water temperature rises to 16-18°C, the best broodstock can be moved into the spawning pool, and 2 to 3 groups of broodstock can be placed in each pool. After the parent fish enter the pond, when it is found that the parent fish are chasing each other closely, it indicates that they are about to lay eggs. Spawning generally starts around 4 o'clock in the morning and ends around 10 am. Generally, 200,000-400,000 eggs can be erupted at one time. The diameter of koi eggs is generally 2.1 to 2.6 mm. After they are laid, they absorb water and swell, and the egg membrane is lifted out. The stickiness will adhere to the fish nest for hatching. After the parent fish lays eggs, take out the fish nest with fertilized eggs, soak it in 5% to 7% salt water for 5 minutes for disinfection, and then remove the new fish and hatch them in the spawning pool.
5. Water quality and water temperature for spawning
The water depth during incubation is generally 30 cm. The water quality and water temperature requirements are the same as the water used for spawning. The length of the incubation time is directly related to the water temperature. It expands with the increase of the water temperature within the appropriate water temperature range. It takes 4-5 days when the water temperature is around 18°C. It takes 3-4 days at 20℃-22℃ and about 3 days at 25℃. The newly hatched larvae do not move or eat. Nutrition is obtained by absorbing the yolk sac in the abdomen. After the yolk absorption is completed, the larvae begin to swim freely and begin to eat external food; at this time, the bait should be fed immediately.
6. Natural growth
When the water temperature is above 18 degrees, growth work can be carried out. When carrying out natural growth, a good fish nest should be prepared, and often aquatic plants, pine needles, palm flakes, nylon ropes, etc. that have been disinfected with permanganate nail solution can be used, mainly as long as the eggs can be evenly attached. Tie the above objects into small bundles, hang them on the water surface of the pond and scatter them evenly on the bottom of the pond. The ratio of broodstock fish is generally one female to two males. If there are many broodstock fish used for growth, 1:1 is also possible. It is easiest to lay eggs in the morning during thunderstorms. Naturally coupled with artificial flushing stimulation, the effect will be better.
7. Artificial growth
Because koi is a hybrid strain, it is difficult to obtain the best results from natural growth. Simple speciesIn terms of species, more than 80 species in 13 major categories can hybridize with each other, but the descendants are very mixed. In order to obtain outstanding and beautiful offspring, we suggest that it is better to use human resources to grow them.
1. Artificial natural growth
Use high-quality broodstock of the same species with good bloodlines, and put them into independent clean water ponds or cages at a male-to-male ratio of 1:2-3. Hang fish nests on the water surface to allow them to spawn naturally.
2. Artificial insemination
Use high-quality broodstock of the same species with good bloodline, with a male-to-male ratio of 1:2, and put them into separate clean water ponds or cages. Fish nests are hung on the water surface. When it catches up and starts spawning, take out the female fish, anesthetize it with an anesthetic, wipe the water on the body with a towel, press the abdomen gently, use a small plate to pack the squeezed eggs, pay attention to this moment No water should be mixed in.
Then use the same method to capture the male fish, anesthetize it with an anesthetic, wipe the water on the body with a towel, press the abdomen gently, suck out the semen flowing out with a straw, and put the semen in the place where you have taken it. Stir the eggs evenly with chicken or duck feathers, and then sprinkle the mixed eggs evenly on the fish nest in the water. Be careful not to spread the eggs too densely, but evenly. This process should be done quickly and correctly.
3. Hatching
After absorbing water, the fertilized eggs can be soaked in malachite green liquid for 5 minutes to prevent the invasion and outbreak of saprolegnia, and then transferred to clean water for hatching. It is best to Add air to the air pump to make the water flow slightly, which helps the eggs breathe.
4. Fry cultivation. When the fry hatch and can swim, sprinkle egg yolk water and feed them continuously for 3 days before they can be transferred to the fry pond for cultivation.
Generally speaking, the growth of koi is not very mixed. The growth of koi is divided into natural growth and artificial growth. In order to obtain high-quality koi descendants, artificial growth is still the most common nowadays, but this The main thing still depends on the breeder's own imagination.
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