Outdoor fish ponds in koi fish are often rich in algae, and both the walls and the water surface are covered with a layer of moss. The appearance of algae means that there are too many nutrients in the water, so it will cause the growth of algae. These algae can absorb nutrients such as nitrate and ammonia in water, which can be said to be a favorable plant filtration system. At the same time, we can also understand the water quality through the changes of these algae. The water quality is clear and green algae are attached to the wall, indicating that the water quality is stable and there are algae.
However, if the water quality is green, that is, a large number of phytoplankton multiply, indicating that there are too many nutrients in the water. At this time, more attention should be paid to avoid algae lodging caused by insufficient dissolved oxygen in waterproof. Because a large number of algae die, fish will also be affected. Algae in aquariums often appear on the leaves, pond walls and filters of aquatic plants. Some are small green spots, and some are green algae layers. The most serious is comb-shaped black algae. As long as algae appear, it is difficult to remove. Change the water frequently and add algaecide. After a period of treatment, after the algae completely fall off, the aquarium will return to its former scene. We call these substances that can lead to the growth of algae nutritional factors in water, including phosphate, nitrate and so on. , mainly from feed residue and excrement. Changing water every 5 ~ 7 days and monitoring water quality regularly are all ways to prevent these nutrients from being too high. Keeping nitrate concentration below 5ppm and phosphate concentration below 1ppm can effectively prevent the growth of algae in water.
Key points of management in different seasons in koi fish.
In spring, the weather temperature changes greatly, and it is easy to suddenly cool down when it is warm at first. At this time, koi fish, who just moved from indoor to outdoor, should pay special attention. When the temperature drops, the fish pond should be covered with plastic film to keep the water temperature stable. When winter goes and spring comes, it is the moment when fish transition from hibernation to recovery, and their constitution is weak. When feeding, we should pay attention to gradually increasing the amount of bait, and put more bait with a large proportion of plants, so as to facilitate the digestion and absorption of koi fish.
The water temperature is high in summer. In order to maintain the normal growth of koi fish, it is necessary to cover the plastic sunshade net and keep the proper water temperature. Otherwise, phytoplankton and green algae will multiply, and the water quality will be turbid, which will affect the growth of koi fish. At the same time, ultraviolet rays have a certain influence on the color enhancement of koi fish. According to statistics, the sunshine illumination in Beijing is 8000 ~ 12000 lux; After covering with plastic shading net, the illumination drops to 5500 ~ 5800 lux. At this time, the light is soft and suitable for the growth of koi fish.
Autumn in August and September is sunny, which is a good season in Beijing. The temperature and water temperature will drop obviously, which is the most suitable season for the growth of koi fish. You can feed more feed to make the fish full. It is best to increase the proportion of animal protein in the bait composition. Conditional areas can feed some silkworm chrysalis, so that koi fish can have a good winter.
When the temperature drops to 0℃ in winter, koi fish swims slowly and eats less. Therefore, koi fish should be moved to indoor fish ponds for the winter in time. The indoor water temperature should be kept at 2℃ ~ 10℃, and the key points should be kept warm and properly fed, so as to keep the fish from losing weight and prevent fish diseases. During the period from June 165438+ 10 to March of the following year, the frequency of management work such as changing water, adding water and cleaning dirt should be reduced as much as possible, and digestible bait should be used more when feeding, mainly to ensure koi fish to safely overwinter in fish.
Breeding techniques of koi fish
Koi fish is a kind of artificial cultured ornamental carp with colored stripes. Introduced from China to Japan, it became an ornamental fish after variation and improvement in Japan. After long-term continuous improvement and breeding, koi fish has formed three lines: red and white, Dazheng tricolor, Showa tricolor and Huangjin 13. Koi fish is known as "the living jewel in the water" and "the king of ornamental fish" because of its strong physique, colorful patterns and elegant swimming posture. I began to study the introduction and artificial propagation of koi fish in early 2003. After May, it achieved initial success: * * laid about 5 million eggs and 265,438+10,000 fry. After breeding, 320,000 high-quality koi fish fry were obtained. The test results are summarized as follows.
Materials and methods
I. Main facilities
There are *** 10 cement pools in the nursery, each with an area of 3m×8m and a water depth of1.2m. The water source is river water, which is used after secondary sand filtration and is equipped with heating and gas supply facilities. There are 0. 1hm2×2, 0.2hm2×2, 0.33hm2×3, 0.55m2×5, 0.6m2×2, * * about 5.34hm2, small earthen ponds are square, large earthen ponds are rectangular, and the water depth is about 2.5m Each earthen pond is equipped with1.
Second, the choice and cultivation of parents.
1, parents' choice
The parent fish is pure and excellent, with obvious strain characteristics and strong and flexible constitution. Koi fish has a beautiful swimming posture and no defects, and her body is clean and free from diseases. The age of the parent fish is over 4 years old for females and over 3 years old for males. The ratio of male to female is 4:3. We * * * entered the parent fish: red and white 13 group, tricolor 2 1 group, gold and platinum 2 groups each, and other strains 2 groups. Among them, women are 4 1, men are 3 1, and women account for 72%.
2. Parental intensive culture
65438122/0, after purchasing parent fish, male and female were cultured in separate ponds, and the total intake was 2%, and the amount of silkworm pupa increased or decreased according to the gonad development of the fish. At the beginning of March, the temperature gradually increased to 65438 0℃ in 3 days, and the micro-aeration disappeared after 24 hours when the running water was stopped. Dissolved oxygen is 4-5mg/L, and the ph value is 6.3-7.
3. Pairing spawning and preparation of fish nests
In order to improve the superior product rate of koi fish's offspring, we paired koi fish according to strain classification, and then induced labor with drugs, including LRH-A2, dom and hcg, and the male dosage was halved. Put into a cement pool for production. Because koi fish fish eggs are sticky and heavy, it is necessary to hang a string of Yangshugen in the spawning pond as a gesture.
Fish nest
4, spawning and hatching
The spawning period of parent fish is usually 7- 12 hours. After spawning injection starts at noon 13:00, spawning begins at night, and the whole process needs to be inflated all the time. Pay attention to observation when laying eggs, and replace Yangshugen immediately after fertilized eggs are full. The poplar roots covered with fish eggs were incubated in an incubator, ventilated, and disinfected with 0.2- 10 methylene blue, keeping the water temperature at 20%. It will be released in three days.
5. Breeding of fish larvae and juveniles
Cleaning the pond 7 days before spawning, applying cow dung 100kg every 0.0667hm2, and then disinfecting with quicklime 100kg (every 0667hm2). After 7 days, add 50 cm of water. In general, rotifers and cladocera in ponds reach the peak demand 10 day, which can just meet the bait demand of fry when they are open.
The day before the fry came out of the film, Yang was directly put into the pond to hatch naturally with the fish eggs. Three days later, the fry began to eat when they began to swim horizontally. At this time, rotifers and cladocera cultured in ponds are mainly used, supplemented by soybean milk. /kloc-After 0/5 days, soybean milk was the main food, and after 25 days, bean cake powder was fed until the fry grew to 5cm. Enter the stage of seed selection and sub-cultivation.
6. Selection of koi fish.
When the fry grows to about 5cm, koi fish's body color has been fully displayed. You can choose koi fish at this time. The standard is: healthy fry should be taken as the standard, and the selection of fry should refer to the strain standard of koi fish, which requires obvious strain characteristics, strong physique and bright color. No spots.
result
First, the prenatal cultivation of parent fish
After 76 days of culture, two of them died before induced labor, and the survival rate was 97.22%. The early stage of the whole process (65438+1October 22nd to February15th) belongs to the indoor normal temperature introduction and storage stage; The middle stage (February1June-March 20th) is the intensive cultivation stage of parents' nutrition; The late stage (March 2 1 to April 8) is the stage of artificial gonad heating to promote maturation.
Second, mating, spawning and hatching.
After drug induced spawning, the action period of parent fish drugs is 10 hour, and the pursuit of spawning begins at 22:00 in the evening. It reaches its peak at 2: 00-3: 00 in the middle of the night and basically ends at 5: 00-6: 00 in the morning. * * * lays about 5 million eggs (* * * lays 250 eggs, and 7 are randomly sampled, with an average of about 20,000 eggs per plant). Egg diameter 1.6- 1.8 mm, fertilization rate was 80%, hatching rate was 75%, and about 3 million plants emerged.
Thirdly, the cultivation and selection of larvae and juveniles.
After 50 days in the soil pond, the fry grow to 4-6 cm. At this time, koi fish's body color was fully displayed. At the beginning of June, he began to fish from pond to pond, and at the same time screened the best and retained the worst. The screening criteria are: obvious variety characteristics, strong physique, bright color and no noise. After 20 days of selection, 2,654,380,000 fry were caught in * *. The survival rate of larvae and juveniles cultured in earthen ponds is 70%. 320,000 fry were selected. The selectivity was 14.5%.
Summary and discussion
1. The sex ratio of parent fish is one of the main factors affecting the spawning and fertilization rate of parent fish.
Because koi fish belongs to in vitro fertilization, the number, distribution, density and quality of sperm in water determine the fertilization rate of fish eggs. So generally speaking,
The ratio of male to female in koi fish is 1:2 or 2:3 to ensure the fertilization rate of eggs. For other reasons, the ratio of male to female in koi fish this year is 4:3, which is the main reason why the fertilization rate of eggs is only 80% this year.
2. The success of cultivating fry larvae in earthen ponds (i.e. cultivating ponds) is the key to complete the fry production task in koi fish this year.
In the cultivation of fry in earthen ponds, we should focus on the following aspects: the construction standard of earthen ponds, convenient water intake and drainage, adequate preparation and thorough disinfection of earthen ponds; The basic bait is well cultivated, which can be synchronized with the time when the fry come out of the film, providing sufficient palatable live bait for the fry; Strengthen the management of patrolling the pond, closely observe the growth and health of fry, find fish diseases such as enteritis and rotavirus in time, accurately treat and control them with drugs, and regularly disinfect and prevent diseases with drugs.
Thirdly, the selection of koi fish is a complicated and comprehensive work.
First of all, we should choose a healthy seed standard, and then select the best according to the evaluation standard of koi fish. Starting from the strain characteristics of koi fish, we should also consider the possible changes in the pattern and color of koi fish's body surface when he grows up. Only by careful analysis can we select high-quality koi fish. Because there are many high-quality parents in koi fish, male and female parents can be paired in strict accordance with strain classification to breed offspring. So the next generation has a high selection rate. The qualified rate of fish exceeding the standard in koi fish is 14.5%. Of course, it is the first year of operation, and there may be some errors (1the second selection in October 1 1.93%, and 250,500 carp exceeding the standard are determined, and the qualified rate of future generations should be1kloc. But overall, the fish selection rate in koi fish is much higher than the usual 5%.
Feeding methods in koi fish
Koi fish is an omnivorous fish. Leftovers, peels, etc. About 10% of animal feed such as viscera, snails, maggots, pupae, earthworms, etc. can be added, mixed and crushed into mixed feed. Bean cakes, vegetable cakes, bread crumbs, fish worms, water worms, radishes, duckweeds, crab meat and clams can all be used as bait. The number and proportion depend on the size of the fish. Live snails can be put more, because after they are eaten, they can stay in the water to eat algae and other impurities attached to the bottom of the water and the wall of the pond, which has the function of cleaning the water quality and is a good bait.
The amount of feed is the key to raising koi fish. If the fish can't finish eating because of over-feeding, it will not only cause waste, but also cause residual materials to rot, destroy water quality and affect the survival of fish. The water quality of the fish pond should be light green and fresh, and the bait residue should be fished out in time when patrolling the pond every day. When the water temperature is high in summer, the water should be changed 1 time every 2-3 days, and the amount of water changed in spring and autumn is 1/3 ~ 1/2 of the original pool. Whether koi fish has a strong appetite depends mainly on whether the water environment is comfortable. The water temperature is suitable in spring and autumn, so it can be fed in moderation. In Xia Dong season, when the water temperature is higher than 30℃ or lower than 7℃, the feeding amount should be reduced as appropriate. Generally, 15 minutes to 30 minutes once is appropriate, and the daily feeding amount is 5% to 6% of the fish weight. Generally, feed 15 and 16 at 6:00 am and afternoon in summer, 1 0/times at 7:00 am and 14 in spring and autumn, and 1 3 and 15 times in winter.
How to raise koi fish?
1, some basic knowledge of koi fish. Koi fish's red is Fei, black is ink, and other colors are called color names. When choosing fish, the redder the better, the thicker the ink the better (the darker the better). Koi fish's fin is called hand fin except pectoral fin, and everything else is consistent with the title in the book! Fish farmers who don't use their own ornamental fish for other purposes are called "lovers" and those who specialize in fish farming are called "operators" For example, "Gong Yu" is an operator.
2. carry water. The key step of raising koi fish is to raise water. With good water, koi fish can easily survive and grow. How to raise water well? Generally, you should keep the water well before putting the fish. There are several specific ways: First, tap water should be naturally placed for more than three days. Leave the tap water in the sun for two days. The third is to burn tap water to 40 degrees and let it stand for 8 to 24 hours. There is also a kind of water that uses solar energy, but because many solar energy has aging problems, water often contains some metal oxides, so it is generally not recommended to use it. The water raised by the above methods is generally used for all water changes and initial fish farming. If the water change is general, the requirements can be appropriately reduced according to the actual situation!
3. change the water. You can't be lazy and take chances to raise koi fish. Generally speaking, it is required to change the water every day, about two tenths of it every day. Then do a big water change every 20 days (total water change), and it is best to have a trickle in and out at any time. The minimum requirement is to change one third of the water once a week. If the mixed water greening is serious during this period, it is necessary to shorten the time of large water exchange and increase the daily water exchange. If there is no special need, please use transparent water for breeding, which is beneficial to viewing. Changing water is the most troublesome and daily work in the process of fish farming, and it is often the most patient and enthusiastic! !
4. put the fish. After you buy koi fish, don't put the fish in the tank immediately, but put the fish bag in the fish tank to adapt to the water temperature (don't open the fish bag). If you put it in immediately, the fish will easily catch a cold (the bigger the fish, the easier it is to catch a cold, which is mainly manifested in standing still, jumping over the jar, smashing the jar, not eating, etc. ), but big fish usually heal themselves, and the life risk factor is small! )。 The time to adapt to the water temperature is generally about one hour. If the original fish water is not very dirty, it is recommended to put it in the fish tank with the water. If the raw water quality is poor, it will easily lead to poor water quality. Open the filter immediately after releasing the fish, and the oxygen explodes, so that the fish can easily and quickly adapt to the new environment. Don't feed the fish for a week after release. First, fish can adapt to the new environment as soon as possible. Second, you can observe whether the fish you bought is sick. If you find anything unusual, please ask the boss to replace it immediately (it is difficult to determine the reason after some fish are fed, and new fish are generally not eaten).
5, medication and daily management. When you go to a fish shop to buy fish, the boss will usually recommend some medicines for you to buy together. In fact, as long as the water is raised well before releasing the fish, there is no need to put those medicines at all. Because the boss often makes some rumors to let you buy more of their things. In the actual process of raising fish, I also don't recommend using drugs, because some of my friends died of drugs for no reason. Think about it, why do you take medicine when you are not sick? If the fish is sick, it is necessary to choose specific medicines according to different situations, but generally speaking, the medicines sold by merchants are not as good as those sold by earthwork (except "everything must be removed"), so when the fish is sick, they usually choose earthwork, such as salt, oxytetracycline, Penicillium powder and berberine. If you can't determine the cause, it is recommended to add a lot of oxytetracycline (according to my experience), because I feel as if Western medicine thinks that disease is inflammation! ! Ha ha laugh ... What specific diseases will be analyzed in detail, so I won't say it here! !
6. Filtering and inventory quantity. In addition to filtering out impurities, the most important function of filtration is to cultivate a biochemical system to make fish grow healthily. If it's not too big, I still suggest buying the filter screen directly from the fish shop owner, because the boss will provide you with the filter system professionally (it's a little economical to do it yourself, but many small problems are very troublesome! )。 In this process, you only need to ensure that the flow rate of your filter pump can make the water in the fish tank circulate four times per hour, and change activated carbon and other substances at any time according to the biochemical damage degree in the filter. So how big a fish tank can support koi fish, and how many koi fish plants can support the growth of koi fish? According to my own experience and related books, it is better to raise a koi fish of about 20 cm every 60 liters to 100 liters of water, and the length of the tank should be above 90 cm. The best water depth for raising koi fish is 60 cm to 250 cm. It is said that the water depth of about 200 cm is the easiest to raise big fish. When the fish is raised in the tank to be close to the width of the tank, it is necessary to change the fish to a larger tank or pool in time.
7. Choose fish. When choosing fish, I suggest you choose what you like and what you think looks good. Don't pursue luxury and novelty. This is the most important thing for beginners, because a good koi fish is not only expensive, but also many fish have color problems (it is said that many well-sold fish will change color and fade after a long time! ! The price of real natural colors is mostly more than 3,000 yuan (the best japanese koi is about 35 cm), and it takes a lot of time to raise fish. If you don't go home, you will spoil the fish. Of course, the most basic requirements for selection are that the fish body surface is undamaged, the posture is normal, the body shape is perfect, the crimson ink is thick, the nose flower is big, and the fish must be long.
8. koi fish and Feng Shui. Koi fish has the function of flourishing geomantic omen, and is known as the King of Geomantic Fish. As early as in ancient China, many dignitaries raised koi fish's prosperous geomantic omen. More is based on the owner's life, keeping fish safe and seeking wealth. According to the books I have read, I think some of them are quite incisive. Let me share it with you for reference only. Generally, people who raise fish for wealth at home can raise three koi fish, two red and one black. If it is used for other purposes, it is better to raise odd numbers, and it is better to raise fish with more than three colors together. Don't put the fish tank under the beam as the cabinet wall (according to the pulse of the room), and don't put it under the stairs, in the kitchen or in the bedroom.