breeding technology

abstract

Monopterus albus is also called eel and long fish. The growth rate is fast, generally, it can grow 10 cm in one month and reach 300 grams in nine months, reaching the standard of commercial fish. Monopterus albus is especially suitable for artificial farming in rural areas and is a good way for farmers to get rich. Eel is a temperature-changing animal. As long as the water temperature is 10-32℃, it can be stocked all year round. Free-range eels require good health, active swimming, no disease or disability, and no limit to size. Because eels bully the weak and bite each other without food, the specifications of eels raised in the same pond should be basically the same. Generally, people who weigh more than 100-350g can be put into the pool for sale at any time; A person weighing more than 50 grams can grow to the commodity specifications of the year when put into the cultivation pool; Less than 50 grams can be put into the nursery pond, which can grow to more than 50 grams in the same year, which can provide large-scale eel species for raising eels in the coming year. Stocking density should be flexibly controlled according to stocking specifications and feeding conditions, generally, it is 1-5 kg per square meter of water surface.

Environment that should be paid attention to in eel culture

You should choose a place with plenty of water and sunrise all year round. In terms of water quality, it is the key technology for breeding Monopterus albus. You must change the water frequently to maintain good water quality, once every 3-5 days in spring and autumn, and once every 0/-2 days in summer. The water depth shall not be lower than 10cm, and the injected water temperature shall not exceed 5℃ to avoid death due to sudden temperature drop.

Build an eel pond

To build an eel pond, we should choose a place with slightly higher terrain and convenient irrigation and drainage, mainly small, with an area of 5-20 square meters or 30-60 square meters and a depth of 80- 100 cm. The shape of the pond should be east-west. In order to prevent escape, another pond edge can be made, which is 30-50 cm above the ground. If the pond is built in hard soil, there is no need to build it. 30-60cm medium hardness soil is exposed at the bottom of the pond, which is convenient for Monopterus albus to dig holes and lurk. Dig a water inlet near the water source and leave a water outlet at the opposite lower end parallel to the bottom of the water. All water outlets should be fitted with fishing net cloth to prevent eels from escaping. Aquatic plants, such as Zizania latifolia, Alternanthera philoxeroides and absinthe, can be appropriately planted on the pond surface13 for keeping eels from the wind. Because eels can breathe oxygen directly in the air, they often need to stick their heads out of the water. Therefore, the water level in the fresh fish pond should be shallow. The water level should be determined according to the specifications of the eel, and the water level in the fry pond should be shallow, generally 10-20cm. The culture pond can be deeper, generally 30-40 cm. The water level in the pool for sale can be shallower. Eels have high oxygen consumption and like fresh water quality. So always inject fresh water. Generally, the water is changed 1-2 times a month in winter, 1 times a week in spring and autumn, and 1 times every 1-3 days in summer, and the water change rate is 20-50% each time. Where conditions permit, micro-flow water can be formed in the eel pond. In hot season, the number of water changes should be increased, or loofah and grapes should be planted beside the pool to prevent sun exposure, cooling and heatstroke prevention. A small amount of omnivorous fish, such as tilapia, carp, crucian carp and loach, can be mixed in the large and deep eel pond, which can remove the residual bait feces and purify the water quality. Before preparing Monopterus albus to enter the pond, a small amount of fermented and decomposed organic fertilizer can be applied to cultivate chironomid larvae, silkworms, aquatic insects and other aquatic animals, or snails or loaches can be put into the pond for cultivation to provide fresh bait for fresh fish. Where conditions permit, black lights can be set in the pool to lure insects into the pool.

[Edit this paragraph] Technical measures for artificial culture of Monopterus albus

1. Breeding species of eel and selection and release of eel.

Monopterus albus with strong physique, smooth body surface, strong activity and uniform size should be selected. Generally, the weight of each tail is 20g. If 30-50g large-sized eels are put in each tail, the survival rate is high, the weight gain is fast, and the yield is high. Fish fry are wild young eels caught in cages, which can also be bought from the market, but the injured eels with broken skin and tail should be removed or artificially propagated. It is better to purchase goods in early spring. It should be released within a week. The stocking amount is generally 0/.5-3 kg per square meter, and 5-6 kg can be put in good conditions. In short, if the stocking specifications are large, the density will be small, otherwise it will increase accordingly. Before stocking, the fish should be disinfected, and the temperature difference between water and water should not be too large.

2. Feeding and management

Monopterus albus is mainly meat, which can be artificially fed with earthworms, small fish and shrimp, snails and mussels. It can also be fed with some plant feeds with high protein content, such as rice bran and bean cake, but the spoiled feed cannot be fed. The bait can be fed after a short-term adaptation of 1-2 days, usually once a day 1 time, and feeding should be carried out in the evening; You can also gradually advance the feeding time and domesticate it to eat during the day. Feed 1 time at 8 am and 4-5 pm respectively. The daily feeding amount accounts for 3-5% of the total weight of eels, and the feeding amount accounts for 6-7% of the total weight from June to August. The amount of bait should be increased or decreased according to the water temperature, bait quality and water quality. The feeding amount increases with the growth of eels. When the growth temperature is suitable, more frequent feeding should be carried out, and feeding should be stopped below 15℃ and 10℃. Feed should be placed on the eating table, which is convenient for grasping the food intake and removing the residual bait. Eels mainly feed on animal food and like to eat fresh food, such as various insects and their larvae, earthworms, small fish and shrimp, silkworm chrysalis, maggots, snails, mussels, large zooplankton, internal organs of livestock and poultry and tadpoles. The bait should be fresh and not rancid, and some plant bait, such as bean cake, bran or corn flour, can be fed in places where animal bait is insufficient. The above plant bait can be mixed with minced fish and shrimp to form a wet mass (which cannot be dispersed in water for a long time) and then fed. Larger bait should be chopped or hung in the pool to tear. Hard-shell bait such as snails, mussels and clams must be crushed before being released. Bait should be fed at fixed points, with 2-8 feeding points in each fish pond. The suitable water temperature for eel feeding is 15-30℃, and it has the habit of hunting food in the daytime and at night. For example, in winter, if fish ponds are covered with plastic film greenhouses or other measures are taken to raise the temperature and maintain a suitable water temperature, eels can eat and grow all year round, thus greatly shortening the growth period, reducing the cost and improving the yield and efficiency. Remove the residual bait before feeding to avoid affecting the water quality.

Prevent escape

Thunderstorm weather is sultry, the air pressure is low, and the water body lacks oxygen. You can see Monopterus albus coming out of the hole, standing upright in front of the body and sticking its head out of the water. Pay attention to injecting fresh water at this time. In rainy days, we should also pay attention to whether the overflow port is unblocked and whether the fishing net is firm to prevent eels from fleeing. There should be no straw rope or wooden stick sticking out of the pool, so eels are most likely to escape with the water in rainy days. The eel pond is small and shallow. When pouring fresh water, you should prevent the fish from escaping. The water surface of the fish pond should be controlled below 20 cm along the edge of the pond, and the firmness of the fishnet cloth and the pond wall should be checked at any time. Especially in the case of food shortage, thunderstorm, long rainy weather or water quality deterioration, eels are the easiest to escape, so we should pay more attention to escape prevention at this time. In addition, we should also guard against the harm of ducks, rats, cats and other enemies to eels.

Screen fish

The competition among eel species is fierce. After feeding for a period of time, the fish of the same specification will be uneven, which is not conducive to the improvement of yield in the long run. Therefore, during the growth period of eels, all eels in the pond should be caught once every 1 month, and after screening, they are kept in different ponds in three sizes: large, medium and small. Before the end of the autumn growing season, all the fish should be caught, and the fish that meet the commodity specifications should be put into the pool for sale. Other fish with different specifications should be stocked in different pools according to the production needs in the coming year. In this way, after a winter adaptation, eel species can enter a prosperous period early next year.

[Edit this paragraph] Management of Monopterus albus culture in summer

1. Feed delicious bait

Monopterus albus is a carnivorous omnivorous fish. I especially like fresh feed, or mixed feed with high protein content, such as larvae of various insects, small fish and shrimp, snails, mussels, silkworm chrysalis, earthworms, fly maggots, and leftovers of livestock. These are ideal feeds for Monopterus albus. Monopterus albus likes to move during the day and at night, and it is better to feed it at 4-6 pm. Monopterus albus is gluttonous and hungry, and its satiety is not easy to be detected. So we should pay attention to regular and quantitative feeding. Generally, every square meter of eel pond should be fed with 400-500 grams of feed every day, accounting for about 5-8% of the body weight of eel. There should be a fixed feeding place and more feeding tables to prevent food grabbing or uneven hunger.

2. Always replenish fresh water.

The depth of eel pond should be appropriate, generally 15-20cm, and the water should be changed frequently, every day or every other day to ensure the quality of fresh water. The weather is sultry. On the eve of a thunderstorm, there will be lack of oxygen in the water. On the eve of this weather, fresh water should be replenished in time. Pay attention to smooth drainage in rainy days, to avoid rain flooding the pool and prevent flight.

Step 3 create a suitable environment

The suitable raw temperature of Monopterus albus is 65438 05-30℃. Too high or too low will affect the feeding and growth of Monopterus albus, so we should pay attention to creating an adaptive environment for Monopterus albus in summer and autumn. Aquatic plants such as water hyacinth, duckweed, arrowhead and water chestnut can be raised in the 1/3 area of the culture pond, and some pumpkins and lentils can be planted beside the pond, and a shelf can be set up on the pond to shade the sun, which is convenient for the growth of Monopterus albus.

4. Pay attention to the prevention and treatment of eel disease

Before stocking eel species, soak them in 4% salt solution or 10ppm bleaching powder for10-20min. Before entering the pond, exotic eels must be soaked in 1 ppm bleaching powder solution or 3% salt solution10-20min for disinfection. Can effectively prevent eel diseases. Monopterus albus will suffer from water mold after injury, so we should be careful in the process of breeding to avoid injury to Monopterus albus. When Monopterus albus suffers from this disease, it can be sprinkled with a mixture of baking soda and salt in the whole pool, or it can be soaked in 3-5% salt solution for 5-8 minutes. During the feeding period, the whole pool is sprinkled with bleaching powder at a concentration of 1 million per month.

5. Overwintering of Monopterus albus

Generally, after June 165438+ 10, when the water temperature drops below 15℃, Monopterus albus begins to burrow into the deep soil layer and go into hibernation until February-March of the following year. Where there is a heat source, keep the pool water at 25-30℃ all year round, so that eels can avoid hibernation and grow all year round. (1) overwintering in dry ponds: drain pond water in winter to keep the soil moist, and cover the upper layer with 18cm straw to prevent the soil layer from freezing. Watch out for mice and cats entering the pond to hurt eels. (2) Overwintering with water: in winter, deepen the water level to improve the water quality, raise the water temperature, break the ice surface in time, and avoid the death of Monopterus albus due to anoxia and suffocation.

[Edit this paragraph] Monopterus albus diseases and control techniques

Ducks must not be allowed to prey in the pond during the growing season, especially in the season when eel seedlings are just released and eel breeding season. In order to prevent cats, rats, birds and other animals from preying on Monopterus albus, it is best to cover the pool with old nets or take other protective measures. In summer, sometimes because of the high temperature, Monopterus albus will suffer from heatstroke and coma. At this time, it is necessary to change cold water, or cool down in the shade, and then feed fresh minced meat. In the early stage of feeding, if the epidermis of eel species is injured, it is easy to cause water mold. The sick eel had white hair, lost appetite and finally died. The control method is to choose healthy young eels and disinfect the eel pond with lime before stocking. If eel with water mold is found, it should be wiped with 5% iodine or soaked in 3-4% salt solution for 5 minutes in time, which can achieve good curative effect. The plum blossom spot of Monopterus albus is a yellow round spot with a soybean on its back. The control method is to raise some toads in the eel pond, because the toad venom on them has preventive and therapeutic effects. If you have this disease, you can peel off the toad's head, tie it with a rope, and drag it in the pool for a few times, 1-2 days to get rid of the disease. Monosomiasis of Monopterus albus is a disease caused by the invasion of trichonematodes into the intestine of Monopterus albus, and a large number of trichonematodes parasitize and cause the death of Monopterus albus. The control method is to clean the pond with quicklime before stocking eel fry, which can kill eggs and prevent diseases. After the sick eel is found, 5 grams (90%) of trichlorfon crystal and 3 kilograms of mixed bean cake powder can be used for every 50 kilograms of eel to make medicinal bait for feeding treatment.

[Edit this paragraph] Prevention and treatment of several common diseases of Monopterus albus

Disease prevention and control should be done well in the process of Monopterus albus culture. Common diseases and prevention methods are introduced as follows:

1. Rotting dermatosis

The sick eel can't move and sticks its head out of the water all day. There are many round erythema of different sizes on their body surfaces, mostly on both sides of the abdomen. Some abdomen will have purple spots the size of broad beans, and serious epidermis will rot into funnel-shaped holes. If you peel off the rotten skin, you can often see the rotten skin and internal organs. Prevention and control methods: (1) It is one of the important preventive measures to change the pool water frequently and maintain good water quality. (2) Spraying 1ppm bleaching powder in the whole pool for 3 days while adding fresh water has a good effect. (3) Feed erythromycin 25,000 units of thiazole mixed bait per cubic meter of water, once a day/kloc-0, and feed continuously for 3-6 days.

Step 2: tinea

This disease is caused by the fact that Monopterus albus bite each other because of excessive stocking density or insufficient bait, and the wound is infected with mold. The wound grew cotton wool-like "white hair", and the sick eel lost its appetite, and finally lost weight and died. Control measures: (1) Soak the eels in 5% salt solution, clean them and release them. (2) Sick patients can be sprinkled with a mixture of 0.04% salt and 0.04% baking soda.

3. Rot tail disease

This disease is easy to occur in high-density eel ponds or during transportation. The diseased eel's tail is inflamed and congested, and then the muscles are rotten and necrotic, so that the tail stalk or tail muscle is rotten, the tail vertebra is exposed, and the diseased eel's head protrudes out of the water, and it is slow to respond and cannot move. Prevention and control methods: (1) Pay attention to the environmental sanitation of the water surface of the eel pond, which can reduce the occurrence and harm of the disease. (2) Spraying 0.2ppm furazolidone in the whole pool. (3) Soaking the disinfected fish with 0.25 unit chlortetracycline solution per ml has a good effect.

4. Capillary nematodiasis

The disease is caused by capillary nematodes invading the intestine of Monopterus albus, which leads to the loss of body weight and then death of Monopterus albus. Control method: (1) Disinfect the eel pond with quicklime before stocking, which can prevent the disease. (2) Every 50kg of Monopterus albus is mixed with 5-7.5g of 9% trichlorfon crystals and fed into mussel meat for 6 days. (3) using a mixture of Chinese herbal medicines, such as Rhizoma Dryopteris crassipes, Fructus Viticis, Caulis Perillae, and Melia Goddess, according to the total dosage of 290g per 50kg of Monopterus albus (the ratio is 16:5:3:5 in turn), adding water three times the total dosage, decocting to12 of the original amount, and pouring out the medicine juice according to the above method.

5. echinococcosis

It is parasitic on the intestine by echinococcosis, causing inflammation and congestion, blocking the intestine, and even causing intestinal perforation in severe cases, leading to the death of Monopterus albus. Control method: (1) Disinfect the eel pond with quicklime before stocking, which can prevent the disease. (2) 40-50g of 90% trichlorfon crystals are added into every 50kg of Monopterus albus feed for 6 days continuously.

[Edit this paragraph] Causes and prevention of death of Monopterus albus in cage culture in winter.

Generally farmed Monopterus albus will be sold around the Spring Festival, and will continue to be farmed in the next year. Monopterus albus cultured in cages often dies during hibernation in winter, which causes great economic losses to farmers. Based on the summary of many years' breeding practice, the author thinks that there are many reasons for the death of eel raised in cage in winter, and corresponding measures can be taken to prevent it.

1. Unhealthy

Monopterus albus died because of its poor constitution and poor resistance to environmental changes, especially sudden changes in water temperature and diseases. Therefore, it is necessary to strengthen feeding management from autumn before overwintering to enhance the physique of Monopterus albus. The main measures are: feeding energy feed rich in protein and certain fat, such as earthworm, snail meat, fresh fish, fly maggot and complete compound feed. Increase the frequency of feeding from once every night to once every morning; In autumn, the water temperature gradually decreases, and the food intake decreases in the morning and evening, and the feeding time can be gradually concentrated at noon when the water temperature is high; Feed enough each time.

2. Water plants make people uncomfortable

In winter, all the aquatic plants in the cage wither, but Monopterus albus still needs to inhabit the aquatic plants in the upper layer of the water body. At this time, if there are too few aquatic plants or there are no criss-crossing dense aquatic plants in this layer, Monopterus albus will not have a good habitat, and finally fall into the cage bottom and die of lack of oxygen. The preventive measures are: before overwintering, a large number of aquatic plants should be cultured in cages. Peanut is the best aquatic plant species, because its water and underwater parts are very developed, and its underwater parts will not die in winter.

3. Poor water quality

Monopterus albus mainly relies on degraded gills and skin to breathe oxygen in the water during hibernation, such as poor water quality and lack of oxygen in the water, which will also lead to the death of Monopterus albus. Therefore, good water quality must be maintained during wintering. The method is to maintain a certain water fertility, often replenish fresh water and maintain a high water level.

4. Water is frozen.

The tolerance of Monopterus albus to low temperature is generally 65438 0℃. In cold winter, if the withered aquatic plants in the cage can't cover the water surface and freeze, it will also lead to the long death time of Monopterus albus. The prevention method is: correctly select aquatic plants for breeding, such as water peanuts, oil sunflower, etc., instead of water hyacinth.

5. Disease invasion

There are mainly water mold, skin rot and grasshopper damage. The disease seriously affects the physique of the overwintering Monopterus albus, and the sick individuals are easy to die in winter, so the disease spread among the sick individuals. Therefore, we must strictly prevent diseases and treat diseases as soon as possible before wintering. Before hibernation, it is necessary to sprinkle some sterilization and pest control drugs on the water to prevent it.

6. Harm to people and animals, etc

Because Monopterus albus is very weak during hibernation, external interference will make it fall into the cage bottom with poor water quality, unable to return to the aquatic plants on the surface, and die of hypoxia and suffocation. Therefore, don't pull aquatic plants at will in winter and stir the water body.

7. The value of cage culture of Monopterus albus

A cage of 6-8 square meters, 20 kilograms of seedlings, can harvest more than 60 kilograms of finished eels by the end of the year, with a net increase of about 40 kilograms. If you can't reach this level, you should review your technical experience. In recent years, the transfer price at the end of each year is higher than that in 30 yuan. Therefore, after deducting the cost, a cage can make a net profit of more than 1 1,000 yuan. A pond with a water surface of 3 to 4 mu can hold at least 100 cages, which can make a net profit of more than 65,438+10,000 yuan a year. The bigger the scale, the more you earn.