CATDOLL : CATDOLL: How to raise mandarin fish_Cultivation methods of mandarin fish

Osmanthus fish feed on live fish and live shrimp. The key to breeding osmanthus fish is to find healthy bait fish and shrimp while ensuring the water quality. If the bait fish fed is unhealthy, osmanthus fish is prone to disease. The following is the knowledge about breeding osmanthus fish, I hope it will be useful to you.

Introduction to Mandarin Fish Mandarin fish, commonly known as Mandarin fish, sweet-scented osmanthus fish, etc., is a freshwater bottom-dwelling fierce fish in the order Perciformes, with tender and delicious meat and rich nutrition. The three main species of mandarin fish in my country are the Cockspurred Mandarin fish, the big-eyed mandarin fish and the spotted mandarin fish, among which the Cockspurred Mandarin fish is the most farmed. Guangdong is the main production area of ​​mandarin fish fry. Every year from March to April, the earliest batch of mandarin fish fry in the country are hatched. At the same time, the adult mandarin fish in Guangdong are sold all over the country all year round. It is understood that the farming of mandarin fish in Guangdong Province increased in 2015, but the total amount of fry put in the country was the same as last year.

Breeding techniques for mandarin fish 1. Selection of breeding site

Mandarin fish is a typical ferocious carnivorous fish, and its living environment requires fresh water and rich dissolved oxygen. Mandarin fish only eat live bait fish when they are not domesticated. These conditions require that the pond conditions selected for breeding mandarin fish should be easy to drain, with a water depth of 1.5-2.5m, less than 10m of silt at the bottom of the pond, and oxygenation facilities. The pond area should not be too large, and 1000-3000O is more appropriate. In order to ensure that there is always a supply of live bait fish, the breeding pond is best located in an area rich in natural wild fish, such as near rivers, reservoirs, lakes, etc. If you breed bait fish to feed mandarin fish yourself, the breeding scale is determined by a ratio of 4:1 between the area of ​​bait fish pond and mandarin fish breeding pond. Of course, whether the transportation is convenient is also an issue that cannot be ignored in choosing a breeding site, because the transportation volume of bait fish is relatively large during the breeding process of mandarin fish.

2. Germplasm of seedlings

Through the experience gained from breeding mandarin fish, the quality of mandarin fish seedlings varies. Now, due to the lagging management of seedlings by the fishery administration and the degeneration of the broodstock used for mandarin fish breeding, the overall quality of mandarin fish seedlings has a downward trend. When purchasing mandarin fish seedlings from other places, it is necessary to investigate the scale and technical level of the mandarin fish breeding farm, and try to purchase seedlings from breeding units that breed and raise their own seedlings and use broodstock caught in natural waters. Ensure that the purchased seedlings have pure germplasm, strong disease resistance, and fast growth rate.

3. Fish breeding model

In the northern aquaculture areas, 4-5cm mandarin fish are generally released in May and June for breeding. About 1,000 mandarin fish are released for every 6660 square meters of water surface. Most of the mandarin fish that year do not reach the specifications of commercial fish, and the specifications are about 350g in November. To reach the specifications of commercial fish over 500g, it is necessary to continue breeding until June or July of the following year. However, the price of commercial mandarin fish, especially live mandarin fish, varies greatly throughout the year, showing a trend of low prices at both ends and high prices in the middle. The price of mandarin fish sold in July and August is generally the highest price of the year. Therefore, the cross-year breeding model of mandarin fish is adopted. Although the breeding time is longer, the benefits are also acceptable.

4. Management during the breeding process

4.1 Feeding of bait fish

If the mandarin fish is allowed to grow naturally by preying on bait fish, live bait fish should be fed immediately after the mandarin fish is placed in the pond. The size (weight) of the bait fish should be less than 1/10 of that of the mandarin fish. Low-value wild fish caught in natural waters should be used as bait fish as much as possible. When the number of wild fish is insufficient, artificially cultivated domestic fish species can be used. During the breeding process, attention should be paid to the amount of bait fish at all times. There should always be bait fish 1 to 2 times the weight of the mandarin fish in the pond. Before feeding the bait fish, it should be disinfected with 3 to 4 saline baths, and sick and dead fish should be removed. In order to maintain the physique of the bait fish, a certain amount of powdered feed should be fed every day.

4.2 Pond water quality regulation

Mandarin fish is a carnivorous, bottom-dwelling fish with strict requirements on water quality. At the same time, due to the large amount of food intake and the large amount of excrement of mandarin fish, the water quality of the pond is easily deteriorated during the breeding process. Therefore, regulating the water quality is the key to breeding good mandarin fish. The following methods are mainly used to regulate the water quality of the pond: ① Add new water. Add water once every 15 days or so, and the water depth of each water addition is 20-30cm; when the water quality deteriorates, the new water should be replaced in time, and the amount of water changed each time should not exceed 1/3 of the original water level. ② Sprinkle quicklime. Quicklime is very effective in regulating water quality. Frequent use can keep the water quality with appropriate alkalinity and hardness. Apply quicklime once every 20 days, with a dosage of 15-20kg per 666O water surface, and mix it with water to make milk and sprinkle it all over the pond. ③ Aerator oxygenation. A 3KW water stirring aerator should be equipped for a 2000-3000O fish pond water surface. The use of aerators follows the principle of "three on, three off" to ensure that the pond is rich in dissolved oxygen. ④ Use microecological preparations. For example, photosynthetic bacteria, Bacillus and EM stock solution, the number of times and dosage must be guaranteed when using.

4.3 Fish disease prevention and control

Mandarin fish is a bottom-dwelling fish, and it is not easy to be discovered in time when it is sick. Therefore, during the normal breeding process, careful observation should be made to find out whether the farmed mandarin fish is sick as early as possible so as to take treatment measures as soon as possible. Mandarin fish are not easy to get sick under normal circumstances, but under artificial high-density breeding conditions, if some common fish diseases occur, it is also quite difficult to treat. Therefore, it is extremely important to take preventive measures against diseases regularly. Mandarin fish are prone to trichodinasis and dactylariasis in the fingerling stage, which can be treated by spraying 0.7ppm copper sulfate, ferrous sulfate (5:2) mixture or conventional insecticides throughout the pond. The most harmful disease in the breeding process of mandarin fish is infectious spleen and kidney necrosis. Preventive measures should be taken for this disease, and fish species carrying the bacteria should not be released. During the breeding period, attention should be paid to keeping the water fresh. In addition, mandarin fish are sensitive to drugs, and it is best to use iodine preparations as disinfectants and bactericidal drugs. When treating parasitic diseases, insecticides with low irritation should also be used.

Mandarin fish seedling cultivation Mandarin fish seedling cultivation is the basis of mandarin fish farming. Mandarin fish seedling cultivation cannot be directly fed with commercial feed or cultivated with fertilizer water method in ponds like other freshwater fish. Therefore, the quality of mandarin fish seedling cultivation technology is directly related to the efficiency of mandarin fish farming.

The cultivation of mandarin fish fry includes two parts: summer flower cultivation and one-year-old fish cultivation.

Summer Flowers

The fry that have just hatched are soft and tender, and are smaller than domestic fish, with a body length of only about 4 mm. After 50 to 60 hours of cultivation, the body length reaches 4 to 5 mm, and the average heartbeat rate is 3 times per second. At this time, the fry begin to eat, that is, they enter the summer flower cultivation stage.

I. Fry cultivation Since the 1990s, the technology of mandarin fish fry cultivation has been continuously improved and enhanced, and the cultivation methods are also diverse. In production, it can be summarized into two methods: flowing water and static water cultivation. Flowing water fry cultivation is divided into hatching tanks and ring channels; static water fry cultivation is divided into fish ponds, cement pools and cages. The survival rate of flowing water fry cultivation is higher than that of static water fry cultivation, but the growth rate is slightly slower than that of static water.

(l) Flowing water cultivation has the advantages of fresh water quality, large water exchange volume, balanced water temperature, small temperature difference, and rich dissolved oxygen, which meets the environmental requirements of mandarin fish fry growth. Most production units adopt this method. The mandarin fish fry that have hatched in the hatching tank (loop) will continue to be cultivated in the original tank (loop) with artificially controlled water flow. In the early stage of seedling cultivation, the stocking density of mandarin fish fry is generally 5,000 to 10,000 per square meter, which gradually decreases as the mandarin fish grow larger.

During the cultivation of mandarin fish fry, the ring channel should be changed once every 5 days or so, and the sediments on both sides of the bottom of the ring channel should be removed. Mandarin fish fry are greedy, so it is best to stop feeding bait fish a few hours before changing the ring channel to avoid unnecessary losses caused by overeating of mandarin fish fry.

(2) Still water culture The pond for cultivating mandarin fish fry is generally a cement pond with an area of ​​30 to 50 square meters and a water depth of 0.8 to 1 meter. Some artificial reefs simulating natural waters can be set at the bottom of the pond to create a good predation environment for mandarin fish fry. Before stocking the fry, the cultivation pond must be thoroughly cleaned and disinfected. The stocking density is generally about 7,000 mandarin fish fry per cubic meter of water. When the mandarin fish grows to about 1.5 cm, it will be better to move it into a cage for cultivation.

2. Feeding Mandarin fish is a typical carnivorous fish. It eats live fry as soon as it opens its mouth, and cannibalizes each other when hungry. This is determined by its biological characteristics. Therefore, accurately grasping the time when Mandarin fish fry open their mouths to eat, selecting good bait fish, and timely supplying palatable bait are one of the key measures for the success of Mandarin fish fry cultivation.

(1) Determination of the feeding time The organ differentiation and development of mandarin fish fry is closely related to water temperature. Generally speaking, when the water temperature is 23.5-25℃, 24-26.5℃, and 26-29℃, the time interval from fertilized eggs to the feeding of mandarin fish fry is 112-120 hours, 105-115 hours, and 90-98 hours, respectively. At this time, mandarin fish fry are active and can actively eat.

(2) Selection of bait fish The size of the bait fish fry directly affects the feeding and survival rate of the mandarin fish fry. In production, it is advisable to select fish fry with flat and long bodies and weak swimming ability such as bream, bream, and silver carp as the starter bait. In particular, live fish fry that have just shed their membranes for 8 hours are the best. At this time, the bait fish is easy to be swallowed by the mandarin fish with its tail. If the old fish fry are fed, the mandarin fish fry can only use a small part of the tail of the bait fish. The remaining part often hangs on the mouth of the mandarin fish fry, which not only affects its movement, but also easily rots and decomposes in the water body, deteriorating the water quality, and even causing fish diseases. If the mandarin fish fry do not get palatable bait fish within 3 to 5 days after they start eating, their activity ability will suddenly decrease, their senses will become dull, and they will gradually become emaciated and die. They may even cannibalize each other and get stuck because they cannot swallow the food.

(3) Bait fish production The mouth opening and body height of mandarin fish change continuously as it grows. Mandarin fish at different stages need to be fed with bait fish fry at a certain developmental stage so that they can be eaten by mandarin fish. For example, a 60-hour-old mandarin fish fry can only swallow a 60- to 216-hour-old slender-scaled cricket fry; an 84-hour-old mandarin fish fry can swallow a 60- to 216-hour-old bream fry; a 108-hour-old mandarin fish fry can swallow bream and carp fry of all stages before 216 hours, and can also swallow grass carp fry of 36 to 108 hours; a 144-hour-old mandarin fish can swallow carp, carp, grass carp, carp, carp before 216 hours, silver carp fry of 12 to 216 hours, and bighead carp fry of 24 to 108 hours. Therefore, timely supply of palatable and sufficient bait fish is an important guarantee for the cultivation of mandarin fish fry. The production of bait fish should be carried out in batches according to the production time, growth and development status and quantity of mandarin fish fry; and while ensuring that the emergence of bait fish fry is synchronized with the start of feeding of mandarin fish; the production of bait fish for the later stage of mandarin fish fry should be arranged, and bait fish of different sizes should be cultivated in the pond in time.

(4) Diet: The diet and the specifications of suitable bait fish for mandarin fish fry of different ages are inconsistent. In the early stage of feeding, each mandarin fish fry is fed 2 to 3 fish per day within 2 days, and the eating speed is slow; at 2 to 4 days old, the diet is 4 to 5 fish per day; at 25 to 8 days old, the diet is 8 to 12 fish per day; at 8 to 12 days old, the diet is 10 to 16 fish per day; at 14 to 15 days old, the diet is 15 to 20 fish per day, and the eating speed increases as the fish grows.

The well-fed mandarin fish fry have a swollen, prismatic abdomen and a slightly arched tail peduncle. In flowing water, they stay still against the inner wall or drift with the water. The hungry mandarin fish fry have a flat body and spread out in the channel to find food. Based on this, we can judge whether there are enough bait fish.

(5) Feeding method During the summer flower breeding process of mandarin fish, it can be clearly seen that mandarin fish swallow bait fish from the tail; often half of the fish is held in the mouth, and the other half is exposed outside the mouth. It eats, swims, and digests, and finally spits out the fish head; sometimes you can see the head of the bait fish hanging on the spines behind the gill cover of the mandarin fish fry, which is often mistaken for parasites. At this time, you should pay attention that in this case, no drug treatment is needed, and the fish head will fall off naturally after a period of time.

The mandarin fish fry start to swallow the bait fish from the tail, which is caused by the internal factors of the mandarin fish fry's development. Although the pigmentation of the newly hatched fry has already occurred, the eye activity has not yet begun. Therefore, it mainly relies on touch to prey on bait fish, and the movement of small bait fish is mainly the vibration of the tail, so they are all swallowed by the mandarin fish fry from the tail. After 7 to 10 days of cultivation, when the mandarin fish fry is more than 16 mm long, it has the appearance of an adult fish. It has not yet grown scales, but its eye function and lateral line system are gradually developed and perfected, and its reaction to the outside world is becoming more and more sensitive. At this time, the mandarin fish fry can rely on touch and vision to prey on bait fish at the same time, and the feeding method changes from eating the tail of the bait fish to swallowing from the head. At this time, the hatched fry of silver carp and bighead carp can be fed; but due to the uneven development of mandarin fish fry, some bighead carp or silver carp fry should still be fed for the small-sized mandarin fish fry to eat, so as to achieve the requirement of balanced growth.

3. Management During the summer flowering period of mandarin fish fry cultivation, meticulous management must be implemented, water bodies must be thoroughly disinfected to prevent pathogens from being brought into the nursery pond; water quality must be strictly controlled, and sewage must be discharged and cleaned in a timely manner; bait fish must be bred in a timely manner, and attention must be paid to the connection with the cultivation needs of mandarin fish fry; bait fish must be strictly disinfected before feeding; drugs must be sprayed into the cultivation pond regularly, and work on preventing and controlling fish diseases must be done effectively, thereby effectively improving the survival rate of mandarin fish fry.

After 13 to 15 days of feeding, the mandarin fish fry grows to 2.5 to 3.5 cm. At this time, the mandarin fish fry has summer flowers and can be used to cultivate mandarin fish seeds.

Fish species

The fish seed breeding stage is carried out immediately after the fry breeding stage. In production, the 3 cm summer mandarin fish will be further cultivated into 6-10 cm or 50-100 grams per fish, which is called the mandarin fish seed breeding stage.

After the fish fry grows into summer flowers, the fish body has grown dozens of times; if it is still kept in the original place, the density will be too high, which will affect its growth and increase the difficulty of management. However, if it is directly put into the water surface to grow into commercial fish, the survival rate will be reduced because the summer flowers are still young and have weak ability to forage and defend against harm. Therefore, it is necessary to further cultivate summer flowers into larger fish species.

There are four ways to breed mandarin fish: special pond breeding, cage breeding, cage breeding, and cage breeding. Generally, the survival rate of mandarin fish in special ponds is higher, and some can reach more than 90%; the survival rate of mandarin fish in cage breeding ponds is lower, generally between 20% and 40%. The stocking density of cage breeding ponds is low; the growth rate is faster, and although the survival rate of special pond breeding is higher, the growth rate of mandarin fish is affected due to the high stocking density.

1. Specialized pool cultivation

(l) The fish pond conditions and stocking area should not be too large, preferably 0.05 to 0.2 hectares, with a water depth of more than 1.5 meters. It should be easy to irrigate and drain, and it is best to keep a micro-flow of water. The fish should be raised by artificial feeding, and the stocking density is generally 3,000 to 4,500 per 1,000 square meters. Before stocking summer flowers, the pond should be thoroughly cleaned and strictly disinfected.

(2) The daily feed requirements for feeding mandarin fish are relatively strict. First, it must be alive; second, it must be palatable; third, it must be free of hard thorns; and fourth, it must be supplied in a timely manner.

① Feeding amount After stocking mandarin fish, regular sampling should be conducted to determine the growth rate, survival rate and pond stock of mandarin fish in the pond. Based on this, and with reference to factors such as temperature changes, the feeding amount should be 5% to 10% of the total number of mandarin fish in the pond; the number of bait fish to be put in should be calculated. It is also possible to calculate the amount of bait fish that is suitable for the average size of mandarin fish (1/3 to 1/2 of the body length of mandarin fish) that needs to be added in the first 2 to 3 days based on the density of the remaining bait fish in the mandarin fish pond. In the total amount of bait fish fed, attention should be paid to the ratio of bait fish of different sizes, so that mandarin fish with different growth rates can choose suitable bait.

② It is better to feed the bait fish every 5 days. Because within 2 to 3 days after feeding, the bait fish's activities are relatively sluggish, and the mandarin fish's appetite is particularly strong, which is conducive to predation. If the time interval is too long, it will easily cause mandarin fish predation difficulties and increase physical energy consumption. More bait fish must be fed, which increases the dissolved oxygen consumption in the pond. On the one hand, it increases the actual bearing capacity of the fish pond, and on the other hand, it is not good for the growth of mandarin fish.

③Solutions to bait fish The most prominent problem in breeding mandarin fish is the need for a large number of bait fish. There are usually four ways to solve this problem:

Original pond cultivation: Using original pond cultivation of mandarin fish can solve the problem of early mandarin fish. Bait fish. The method is to put bream, silver carp, bighead carp, grass carp and other fish fry in batches 10 to 15 days after stocking mandarin fish, with a stocking density of 3 million to 5 million per hectare, fertilize the pond with water, and sprinkle soybean milk every day. When the bait fish grows to about 1.5 cm, it is just the right bait for mandarin fish to be put into the pond in summer.

Equipped with bait fish breeding pond: Prepare bait fish breeding pond with a ratio of 1:1-2, stock white crucian carp, bighead carp, silver carp, bighead carp and other species that are easy to reproduce, easy to catch, and are popular with mandarin fish, and stock 750,000 summer flowers per hectare; other summer flowers species raised in ponds are stocked as usual, and then the fish species of palatable size are screened out and fed to mandarin fish according to the principle of pulling nets in stages and in small quantities and multiple times. Generally, pull nets once every half a month, and 10-20 kilograms each time is appropriate. In October, the nets will no longer be pulled after the first half of the month, and more fish can be caught in the last time to ensure that there is sufficient bait in the later stage of mandarin fish breeding, and the fish species in the bait pond will grow well in the later stage. This method shows the ecological balance and coordination between various species in the breeding system and improves the economic benefits of pond breeding.

Cultivate small-sized domestic fish fingerlings: Plan to appropriately increase the stocking density in the one-year-old domestic fish fingerling breeding pond, and take out a certain number of small-sized fish fingerlings in batches at different times to feed the mandarin fish. This method can not only ensure the supply of bait fish for mandarin fish, but also make full use of the fish pond; improve the efficiency of the fish fingerling pond.

Utilizing wild fish: This method can harvest mandarin fish without increasing any cost and improve the efficiency of the pond.

(3) Daily management: Patrol the pond once in the morning, afternoon and evening every day to observe the fish activities, feeding, water quality changes, etc.; and regularly measure the water temperature and pH, and keep records. The water level of the pond for raising mandarin fish should be shallow at the beginning, 50-70 cm is better, because the fish are smaller at this time; the activity ability is weak, and the low water level is conducive to raising the water temperature. Relatively increase the density of bait fish. After several days of growth, adopt the method of phased water injection to gradually increase the water level of the pond to increase the dissolved oxygen content in the water and the activity space of the fish. Generally, new water is injected twice a week, and the water is changed once every two weeks to keep the water fresh; the transparency is controlled at about 40 cm. The specific number of water injections and the amount of water injected each time should be determined according to the actual situation. Mandarin fish are very sensitive to acidic water quality, so quicklime water is added every once in a while to adjust the pH. Mandarin fish cannot tolerate low oxygen, so it is best to equip the pond with an aerator. When the weather is hot and humid, keep the machine running for 1 to 2 hours at noon and for about 2 hours between 2:00 and 5:00 in the middle of the night. Ensuring sufficient dissolved oxygen is an important measure to improve the growth rate and survival rate of mandarin fish. During the breeding process, we must also follow the principle of early prevention when there is no disease and early treatment when there is disease, spray drugs regularly, and do a good job of sterilization and insecticide.

(4) Pooling of mandarin fish for wintering In late autumn and early winter, when the water temperature drops to around 10°C, pooling of ponds can begin. The purpose of pooling is to classify and count mandarin fish of different sizes for stocking or sale. Pooling allows a comprehensive understanding of the current year's fish production, summarizing experience and lessons learned, proposing a production plan for the next year, and cleaning the stocked fish ponds in a timely manner to prepare for next year's production.

The following points should be noted when merging fish ponds: First, merging fish ponds is generally carried out on a sunny day with a water temperature of about 10℃. When the water temperature is high, the fish have strong mobility; the oxygen consumption is large; the fish are easily injured during the operation; when the water temperature is too low, it is not suitable to merge ponds on freezing and snowing days to avoid the death of fish due to frostbite. Second, the number of bait fish in the pond should be gradually controlled half a month before pulling the net. Pulling the net, fishing, selecting fish, and transporting should be done carefully to avoid fish injuries. Mandarin fish species raised in adult fish ponds (or broodstock ponds) can be merged in time with the fishing of adult fish (or clearing of broodstock ponds). When pulling the net, special attention should be paid to prevent the death of mandarin fish species due to lack of oxygen. Third, choose a fish pond that is leeward and sunny, with an area of ​​0.1 to 0.2 hectares and a water depth of more than 2 meters as a wintering ground. Mandarin fish species with a size of 10 to 15 cm can be stocked with 45,000 to 75,000 per hectare.

After the mandarin fish ponds are combined, management should still be strengthened to keep the water quality at a certain level of fertility, and a certain number of bait fish should be placed in the ponds for them to eat. In the areas north of the Yangtze River, the winter ice season is long; oxygenation measures should also be taken to prevent hypoxia in the fish ponds.

2. Other breeding methods

(1) There are two types of cage culture: adult fish pond and broodstock pond. The stocking time is generally from June to July each year. The cage culture of summer flower mandarin fish with a size of 2.5 to 3.5 cm is carried out at a stocking density of 4,000 to 7,000 per hectare. Usually, the cage culture pond does not need to be specially fed. Wild fish in the adult fish pond or broodstock pond can be used. Therefore, before the summer flower is released, the number of wild fish in the pond should be investigated and tested. If there are a large number of wild fish in the pond, the stocking amount can be appropriately increased. During the breeding process, three points must be paid attention to: First, it is not advisable to cage culture other varieties of summer flower in the cage culture pond to prevent small-sized fish from being swallowed by them; second, mandarin fish are sensitive to drugs, and the slightest carelessness may cause the annihilation of the mandarin fish species. Therefore, when using fish medicine, you should choose to use it and accurately calculate the amount of medicine used, especially in high temperature seasons, you should be more cautious in using medicine, usually use low doses or stop using it; third, mandarin fish has higher requirements for dissolved oxygen than domestic fish; it is easy to float, so the water quality of the culture pond should not be too fertile, especially for adult fish ponds dominated by fertile fish. Therefore, regularly adding new water to keep the pond water fresh and high in dissolved oxygen is also one of the key measures for the success of culture.

(2) Interception and breeding: Small rivers and ditches are rich in wild fish and have better water quality and dissolved oxygen conditions than ponds. In a suitable area of ​​a river or ditch, a section of water is cut off with a net and a certain number of summer mandarin fish are released. This method can not only utilize wild fish in the river but also obtain mandarin fish with high economic value. Generally, 3,000 to 5,000 fish are released per hectare.

(3) Cage breeding The size of the cage should be 50 to 100 square meters. The mesh size should be determined according to the size of the summer flower of mandarin fish and the size of the bait fish. The location should be sheltered from the wind. It should be sunny, with a wide surface and a certain amount of micro-current. The bottom of the cage should be at least 0.5 meters above the bottom of the water. The stocking density is 20 to 40 per square meter.

The breeding and management of these methods are basically similar to those of special pond cultivation.

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