Habitat
The eel prefers to live in clean, unpolluted waters, and is the purest water creature in the world. The eel grows in rivers and streams on land and migrates to spawning grounds in the ocean to lay its eggs when it matures, spawning only once in its life and dying afterward. This life pattern, in contrast to the anadromous nature of salmon, is called descending migratory (catadromous). Its life history is divided into six different developmental stages, and in order to adapt to different environments, the body size and color of the different stages change dramatically: egg stage (egg-stage): located in the deep sea spawning ground.
The willow leaf eel (leptocephalus): drifting for long distances in the ocean with the currents, at this time the body is flat and transparent, as thin as a willow leaf, so it is easy to follow the waves. Glass eel (glass eel): when approaching coastal waters, the body turns into a streamlined shape to reduce resistance, in order to get out of the strong currents. Eel threads (elvers): Black pigmentation begins to appear as they enter estuarine waters, but they also form a source of fry for the aquaculture industry. Yellow eel: During the growth period of the eel in the river, the belly of the eel is yellow in color. Silver eel: At maturity, the eel's body turns silver-white, similar to that of deep-sea fish, while its eyes become larger and its pectoral fins widen to accommodate swimming back to the deep sea for spawning. The sex of the eel is determined by the acquired environment. The proportion of females increases when the population is small, and decreases when the population is large, with the overall ratio favoring an increase in the population. Eel fry cannot be bred by artificial propagation, mainly because eels have a very specific life history that is difficult to simulate in an artificial environment. The Japanese eel grows into an adult eel in a freshwater river, and in the summer, it begins to migrate down to the sea, i.e., it swims from the river to the ocean to spawn, which is the opposite of the anadromous migration of trout and salmon, which swims from the ocean back to the river to spawn. Its spawning grounds are thousands of kilometers away in the deep sea between the Philippines and the Malaysian Archipelago. Scientists discovered this spawning ground mainly because many of its newly hatched young are caught here. The eel's young are about 6 centimeters long and weigh 0.1 grams, but their heads are narrow and their bodies are high, thin and transparent like a leaf, so they are called "willow leaf fish". Its body fluids are almost the same as those of seawater, so it can be drifted long distances with ocean currents with little effort. It takes about half a year to drift from the spawning grounds to the Kuroshio Current and then back to the coast of Taiwan, and only a month before it reaches the shore does it begin to metamorphose into the slender, transparent eel threads that are also known as the "glass fish". Therefore, from December to January every year, fishermen will be busy catching eel threads that are about to go back to the river with hand nets on the coast near the estuary and sell them to the farmers. Only after the eels are bought and stocked by the farmers do the colors of the eels appear, turning them into yellow juvenile eels and silver-colored adult eels. The largest eel that can be caught under natural conditions is 45 centimeters and weighs 1,600 grams. Eels spawn and reproduce in the deep sea and grow in freshwater environments. The eel is fierce, voracious, active, ambulatory, strong tendency to rotate the light, like running water, good warmth. The adult eel grows fast, with a rounded appearance, like a round vertebrae, black color and body, more artificial culture in recent years, and crispy meat. This fish is common in all seasons of the year, but in summer and winter seasons are the most fat and delicious. Eel is rich in nutrients, delicious flavor, less thorns and meat, and has a cool summer, nourishing and strengthening the role of the body. Another eel, belonging to the gill family, also belongs to the fish, also like a snake, no scales, belly color yellow, so the name eel. Eel was born in the pond mud hole, or freshwater riverbanks, away from the water is difficult to live, to the people captured when full of saliva foam slippery gurgling. Eel is not only a kind of tender meat, taste delicious food, and since ancient times has recognized its tonic and medical role.
Farming techniques
Open water culture
Open water culture is the main farming method in China. The scale of the eel farm is 50 acres. Breeding facilities mainly include eel ponds, injection and drainage systems and ancillary facilities. Use rivers, lakes, reservoirs and groundwater as water sources. Generally, only 1/10-1/7 of the pool water is exchanged every day, and it mainly relies on floating cyanobacteria and water trucks or aerators to increase oxygen to improve water quality. The advantage is that the cost of building a pool is low and power consumption is low. The disadvantage is that the yield is low, generally only 1000-2000 kilograms per mu. 1. Breeding facilities (1) eel pool specifications eel pool can be divided into a pool, two pools, three pools and adult eel pools four. The ratio of these pools in the eel farm are 2:8:15:75, i.e. a 50 mu water surface of the eel farm, the first class pool of 1 mu, the second class pool of 4 mu, the third class pool of 7.5 mu, the eel pool of 37.5 mu. The uses and specifications of these pools are as follows. Grade 1 pool: used for eel fry attraction training and raising eel fry to about 0.2 grams. The area is 50-60 square meters and the depth of the pool is 0.8-1.0 meters. Secondary pool: keep eel seed with weight of 0.2-2 grams. The area is 200-400 square meters, the depth of the pool is 1.2-1.5 meters, and the water depth is 0.8-1.0 meters. Tertiary pools: for eel species weighing 2-20 grams. The area is 400-800 square meters, the depth of the pool is 1.4-1.5 meters, and the water depth is 1.0-1. 2 meters. Adult eel pool: to raise eel species weighing about 20 grams into 150-200 grams of edible eels. Area 800-1200 square meters, pool depth 1.5-1.6 meters, water depth 1.0-1.2 meters. (2) Eel pool shape and structure The shape of the eel pool at all levels is good to be round or square with the corners cut off. According to the eel escape, difficult to catch and water quality requirements of the characteristics of the higher, in the structure must have anti-escape, easy to catch and convenient injection and drainage functions. Pool wall is useful stone, brick masonry, cast concrete and concrete prefabricated panels cut three forms, vertical smooth walls around the pool, wall wall height 0.8-1.6 meters, the top of the wall with a cover plate "pressure mouth", the cover plate extends to the pool of 5-10 centimeters, the embankment should be higher than the water surface 0.3-0.5 meters. The bottom of the pool has a pot-bottomed and flat-bottomed two kinds of shape, the requirements of hard, no water leakage. Bottom paved 20 cm thick stone slag, raking and compaction, and then paved 5 cm of yellow sand seam, a pool should also be cement mortar bottom, in order to collect seedlings. The bottom of the pot-shaped drainage is located in the bottom of the pool in the center of the lowest place, the bottom of the flat low-shaped pool tilted to the drainage port, the water inlet and drainage port cross opposite. The water injection port is located on the top of the wall, 20-30 cm above the highest water level of the pond, and extends into the pond about 30 cm; the drainage port is located in the opposite side of the water injection port, the periphery of the three gates; the first mesh gate to play a role in preventing the escape of stainless steel mesh or polyethylene sieve silk mesh, and its mesh, eel seedling pond 1-1.5 mm, eel seed pond 1.5-2 mm, adult eel pond 2-4 mm. The second board gate or dark box, the bottom of the overhang, pressure out of the bottom of the sewage. The third board gate, play the role of overflow, so that the eel pool water level to maintain a constant. Eel ponds have very high water quality requirements, not only each pond requires separate injection and drainage systems, but also the entire eel farm injection and drainage water sources must be strictly separated. Otherwise, it will cause its own pollution due to eel feces and a large number of microcystis deaths, resulting in serious eel deaths. (3) Food shed Eels like to feed in the shade, should be set up in the sunny and windy pool side of the food shed (including food platform, food court and shade shed). Food platform is 90 × 45 × 20 cm rectangular frame, the bottom of the frame taut a mesh size can let the eel species free through the nylon mesh; food field in the food platform below the bottom of the water, the top of the pavement slag or snail shells, requires solid flat; food platform above the shade. 2. eel breeding (1) eel breeding eel breeding is the weight of 0.1-0.2 of the eel breeding of the white eel to the weight of 10-20 grams of the eel process, most of the eel species can be raised in the second year, the eel can be raised to the weight of 10-20 g of the eel, the eel can be used as a food source for the eel. In the second year, most of the eel seeds can be raised into food eels for market (150-200g/tail). Eel fry are generally raised into eel species in three levels. All levels of eel pool stocking specifications and densities are as follows: first class pool stocked with 0.1-0.2 grams of eel fry 0.2-0.3 kg per square meter; second class pool stocked with 0.3-2 grams of eel fry 0.3-1 kg per square meter; third class pool stocked with 2-20 grams of eel seed 0.5-2 kg per square meter. Eel seedling selection: quality eel seedling requirements head broad kiss blunt, neat specifications; swimming lively, body without trauma, body color smooth jade white; skin moist, strong body, no pathogen parasites. The specification is about 6000 tails per kilogram. Eel seedling stocking: stocking time for March-April, water temperature of 20 ℃ above stocking is more appropriate. Before releasing the fry, the cultivation pool and the eel fry should be sterilized with drugs. The disinfection method of the cultivation pond is the same as that of the domestic fish fry pond. Eel fry disinfection method can refer to Table 7-2. The stocking density is according to the requirements of the primary pond. Feeding training: Feeding training is the key technology for the success or failure of eel raising, and it takes about one month of training. In the first week after the eel seedling is placed in the pond, you should try to make the eel seedling change from scattered feeding to centralized feeding. Generally from the evening, the use of earthworms as bait, will be clean earthworms scattered cast on the food table, feeding 4-5 times a day, the daily feeding amount of eel seedling 20-40% of the total weight. At the same time, hang a 15W electric lamp above the food table, the eel fry to the food table around, concentrated feeding. You can also put a canopy over the food table in the daytime to create a dark environment, which will also induce the eel fry to feed. After one week, if most of the eels are lured to the food table to feed, it shows that the concentrated feeding training has been successful. Then gradually postpone the feeding time backward, and finally switch to daytime. Starting from the second week, gradually reduce the feeding amount of earthworms and increase the amount of mussels, pork spleen or minced meat of fresh fish and other fresh feeds, feeding 4 times a day, with the daily feeding amount accounting for 10-15% of the total weight of the eel fry. 15 days later, gradually mix the earthworms or minced meat with the compound feeds and gradually increase the proportion of the compound feeds. 1 month later, all the eel fry can be switched to the compound feeds, feeding twice a day, with the daily feeding amount accounting for 5-8% of the total weight of the eel fry. The daily feeding amount is 5-8% of the total weight of the eel fry. The feed should be kneaded well with water, and if possible, appropriate amount of oil should be added. Feed should be fed immediately after mixing to prevent α-starch from cracking and affecting adhesion. Classification feeding: eel fry in the feeding due to the ability of individuals to compete for food between the strong and weak, resulting in a large difference in the size of the individual, so every 20-30 days will be different sizes of eel fry sub-feeding, sub-feeding should be stopped for a day before. Because of the eel fry individual is still small, the first few times of sub-culture can be used dense eye fishing sea fishing under the food platform, will be the first on the food platform of the healthy fry priority points out; later as the individual gradually grow, available Guangdong fish sieve or different mesh knotless net for sorting work. After sorting and bathing with dysentery, they can be stocked according to the level. The stocking specifications and densities of all levels of nursery pools are as described above. The daily dosage of eel feed after sorting is 3-5% of the total weight of the fish. Eel fry feeding to the middle and late November, most individuals can grow to about 20 grams, can be used as eel seed into the adult eel pool culture. Water quality regulation: Cultivate and manage the water quality of the eel pond is a reliable guarantee of high yield eel farming. The main measures are: ① Cultivate microcystic algae, increase the dissolved oxygen in the water. As the source of dissolved oxygen in the eel pond water mainly depends on the microcysts in the cyanobacteria produced through photosynthesis, therefore, when the number of microcysts in the pond water is small, the transparency is too large, the microcysts should be fished from the nearby ponds into the eel ponds, and the application of ammonium sulphate, 1.0-1.5 kilograms per acre for 2-3 days, to strengthen the fertilizer, so that it can reproduce rapidly, growth. ② Master the water color. Pool water should be kept thick green palladium, transparency of about 25 centimeters is appropriate. When the water color changes from dense green to light green or light yellow, or the transparency is greater than 25 cm, ammonium sulfate should be applied in time, 0.5-1 kg per mu for 2 consecutive days. When the microcystis is too much, the water color is too thick, and the transparency is less than 15 cm, new water should be injected to increase the transparency to about 25 cm. ③ Get rid of worms in time. Zooplankton is the enemy of Microcystis aeruginosa, especially the biggest impact of rotifers, in order to limit the reproduction of rotifers, eel ponds can be equipped with a certain number of bighead carp, generally per mu can be equipped with 2-year-old bighead carp 10-20 tails. If the zooplankton is still reproducing too fast, then crystal trichlorfon can be used to splash, so that the pool water is 0.5-1ppm concentration. The water can be injected into the pond at the right time. In order to improve the water quality of the eel pond, a waterwheel aerator should also be installed to increase the oxygen, and the start-up time can be referred to the part of domestic fish culture. At the same time, the water should be changed 1/10-1/7 every day. When changing water, the residual bait and feces in the pool water should be discharged out of the pool. (2) Adult eel aquaculture Adult eel aquaculture is the production process of raising eel species weighing more than 20 grams into commercial eels weighing 150-200 grams. At present, there are two forms of eel farming in our country: specialized and mixed farming. Pond specialization: that is, in the pond high-density monoculture eel, the general Luotian pond mu output of more than 1,000 kilograms. Eel seed stocking: Before stocking eel seed, the eel pond and eel seed should be sterilized with drugs before being put into the eel pond for rearing. Stocking time is generally in March, late to early April, when the water temperature is above 13 ℃. The stocking density depends on the yield index, eel pond conditions, eel species specifications and breeding techniques and other factors to determine. Generally, the stocking quantity of more than 1000 kilograms per mu is about 20 grams of eel species specification, 150-200 kilograms per mu; about 50 grams of specification, 300-400 kilograms per mu. Semi-flowing pond stocking density, per square meter can be put about 20 grams of eel species weight 3-5 kg, well-equipped flowing pond per flat language word meter can be put 10-15 kg. Feeding management: Feeding management mainly includes feeding, rotating catch and release, water quality management, fish disease prevention and control. Feeding feed date eel feed fresh feed and feed with two types. The feeding method adopts the principle of "four fixed". Every day 9-10 a.m. feeding, in the water temperature of 25 ℃ daily feeding amount, with feed for the total weight of the pond eel 2-5%, fresh feed for 10-15%. Early spring or late fall when the water temperature is low, or when the water temperature exceeds 30 ℃, the daily feeding amount can be reduced as appropriate. Generally, it is required to finish the feed within 20 minutes. Eel feed mixing should be uniform, soft, add water and oil mixing amount can refer to Table 7-3. mixing should be fed immediately. Rotation catch and release date eel in the feeding process, individual growth rate difference is very large, must take staged stocking, staged fishing, catching the big stay small, catching the big to make up for the small and other measures. Generally every month or so graded thinning once, so that the same pool of eel specifications neat, reasonable density. the end of March stocking of eel species, in early June has been part of the market specifications, you can carry out the first fishing; after June, the water temperature rises, the eel want to flourish, fast-growing, to the end of July can be carried out in the second fishing, fishing and immediately replenish the eel species; in early September, there are a considerable number of market specifications, the third fishing; mid-November for the clearing of the eel, the eel is not a good idea, but the eel is a good choice. In early September, a considerable number of eels reached the market specification, and the third fishing; in mid-November, the pond was cleared for fishing, and those that did not reach the market specification were kept as eel seed for the following spring. Classification and dilution before 1-2 days to stop feeding, and to replace the pond water, the implementation of the original pond hanging water, so that the eel empty stomach food, and then smooth fish sieve for selection. The operation should be careful and meticulous to prevent damage to the fish. Water quality management date water quality management measures can refer to the practice of the seedling cultivation stage. Pond mixing date in the breeding of four large fish ponds mixed eel, there are two ways of eel feed and eel feed. The former with 15-20 grams of eel species 50-100 tails per mu, eel to fish ponds in the wild fish and shrimp, benthic critters and feed debris for food, the end of the year can be caught weighing 150-200 grams of food eel 10-15 kilograms; the latter is to carry out high-density mix-farming, with 15-20 grams of eel species 1000-2000 tails per acre, feeding once a day eel feed, feeding amount of eel total body weight of the 1-2% of the total weight of the eel. The eel can also eat wild fish and shrimp and benthic animals in the pond. At the end of the year, 150-300 kilograms of food eels can be caught. These two mixed farming methods have been widely promoted in the Pearl River Delta in Guangdong, so that the economic benefits of fish ponds significantly improved.
High-temperature season focus on good water quality management
"Water" is the lifeblood of the eel industry, good water quality management, is a high-temperature season breeding work of the highest priority. 1. Artificial cooling method. The water temperature down, not rely on "air conditioning", no "fan", with artificial methods can be achieved to reduce the purpose of water temperature. The practice is: 1 in the top of the intensive pool, covered with a layer of black shade cloth, that shade cloth can be ventilated and breathable, but also can block the direct sunlight, adding a cool degree of the water surface, so that the water temperature can be reduced by 1 ℃ ~ 2 ℃ or so. 2 advance sewage water. Normal sewage water, are in the morning at 8:00 a.m., the high temperature season can be advanced to 6:00 a.m., because the water body at night is relatively cooler than during the day, while the water temperature is low, when the sewage water, so do the same can be achieved to reduce the water temperature. 3 to raise the water level. High temperature season, no matter whether it is a soil pool or, intensive pool also, always raise the water level to the highest boundary. High water level, water space, the temperature rises slowly, is also a good way to cool down. 4 increase the amount of water exchange, when the highest temperature at noon, the use of machine wells or deep wells to the pool to supplement some of the cooler water, but also can obviously receive the cooling effect. 2. Flood exclusion method. High-temperature season is also a season of frequent rainstorms, eel farms often because of flooding into the pool, causing eel poisoning, insect pests, gill rot and many other diseases occur, how to avoid flooding into the pool: 1 where heavy rain, take no feeding, no sewage, no water change, rather than less than feeding a meal, not to risk the use of flooding. 2 pools into the small amount of flooding how to do? Once a small amount of flood water has entered the pool, use potassium permanganate 1.5ppm to regulate the water quality, or use quicklime 15-20ppm to improve the water quality, or you can also use water purification treasure 3ppm to purify the water quality.3 Adjust and change the time of sewage and water change to stagger the chance of direct contact with flood water. During the flood period, sometimes you can advance the sewage water change, sometimes you can also delay the sewage water change, not routine restrictions, try to avoid flood water into the pool.4 A lot of flood water into the pool how to do? Once a large amount of flood water enters the pool, first of all, stop feeding, then purify the water with a water quality improver such as HaiZhongBao, and finally, use potassium permanganate 2 ppm+insecticide 2# for de-worming, sterilizing and disinfecting.
Greenhouse Stopper Culture
This type of culture is matched with dew ponds, with a steel skeleton above the cultivation ponds, covered with plastic tiles or film, and heating measures to keep the pond water at about 25℃. The specifications and stocking density of eel pools at all levels as well as the feeding and management methods are basically the same as those of open-air pool culture. Eel fry can be separated from the pond after about one month of feeding, with a survival rate of about 80%. eel fry stocked in late February and kept for 120-150 days can be raised to 3-5 grams of eel seed, and by the end of the year, they can be raised to about 50 grams of eel seed, and 20-30% of the eel seed is raised to food eel for sale.
Eel disease control
Eel farming should pay special attention to the prevention and control of fish disease. The main diseases are water mold, small melon worm disease, rotavirus disease, anchor head lernae, gill disease, eel swim bladder nematodes and red fin disease, etc., which can be prevented and controlled according to conventional methods.
Eel is also known as white eel, white loach, etc. It is a valuable fish in freshwater aquaculture. Its meat is tender and flavorful, with high nutritional value, and it has medicinal effects such as removing blood stasis, nourishing and toning. Eel grows rapidly, strong adaptability, even in the dissolved oxygen is very little, other fish can not live in the waters can live normally, artificial culture technology requirements are not high, the feed source is also wide. In recent years, a large number of farmers in the earthen pond eel aquaculture, are to obtain high yield and high efficiency. Early spring put eel seed, late fall and early winter can be marketed, generally 800 kilograms per mu ~ 1000 kilograms. Now the eel earth pond high-yield and efficient farming tips are introduced as follows: First, the pond selection and disinfection Eel ponds require ventilation and sunny, adequate water supply, the area should not be too large, in the earth pond planted around 0.8 m to 1 m wide water lily or water peanut, etc., and with a fence or mesh fence, which can prevent the eel from fleeing, but also can be shaded, and is conducive to its growth. Before stocking the land should be dug out too much silt, level the bottom of the pool, repair the ridge and the inlet and outlet, in the eel species in the pool before 10 days ~ 15 days per 1000 square meters with lime 100 kg ~ 125 kg to disinfect the pool, thoroughly kill the wild fish and hostile organisms. Then in the eel species in the pool 5 days ~ 7 days before the injection of water 0.6 m ~ 0.7 m deep, the water inlet with 60 mesh sieve filtration. Finally fertilization, generally per 1000 square meters splashed with 300 kg ~ 400 kg of rotting pig and cow dung, to be light green or yellowish-brown water and then put the eel seed, so that it can eat enough natural bait in the pool. 15 days or so will deepen the pool water to 1.5 meters. Second, the eel seed treatment and put eel growth temperature of 20 ℃ ~ 28 ℃, water temperature in 12 ℃ when the beginning of feeding, so put the time is generally in late February to mid-March. Before placement, first put the eel seed bag into the water to soak 20 minutes ~ 30 minutes to adapt to the water temperature, the temperature difference between inside and outside the bag is less than 5 ℃ before removing the bag, and then use a small water basin to the bag poured into 2 pots ~ 3 pots of water, so that the eel species from the state of high oxygen dissolved state gradually adapted to the state of low oxygen dissolved. At the same time, the eel seed should be sterilized before putting in, every 50 kilograms of water with salt 0.75 kilograms ~ 1 kilograms of eel seed immersion 15 minutes ~ 20 minutes. The eel species required to be placed in the body color greenish gray, skin, rich in elasticity, swimming active, the same pool of eel species specifications to be neat and consistent, otherwise due to the mutual competition between the eel will affect the feeding of the individual body weak. Stocking density is generally per 1000 square meters can be put 4000 to 5000 tail 20 grams of eel; 50 grams of about 3000 to 4000 tail; 100 grams of about 2000 to 3000 tail can be put. At the same time, every 1000 square meters of soil pool can be mixed with bighead carp 50, silver carp 30, tilapia 200, on the one hand, can be filter-feeding plankton, food net eel feces, play a role in purifying the water; on the other hand, it can increase the fish production. Feed type and feeding eel artificial aquaculture mainly rely on special feed (available on the market), and in every 50 kg of special feed add multivitamin (vitamin a, b, c, e) 50 grams ~ 60 grams, cod liver oil 1.5 kg ~ 2 kg (water temperature below 20 ℃ or 35 ℃ should stop supplying cod liver oil). Add less for young eels and more for adult eels. If there is a temporary lack of specialized feed, available small mixed fish, livestock and poultry offal, silkworm pupae and other animal feed grated and mixed with flour instead of its crude protein content must be more than 40%. Eel is carnivorous fish, voracious. Feeding should implement the "four" principle, that is, quality, quantity, timing, positioning. Fixed quality: that is, to ensure the quality of feed. The modulated feed should be soft and hard (1.2 times to 1.3 times the amount of water), fresh and clean, not spoiled and corrupt. Quantitative: that is, the amount of feeding according to the specifications of the eel, feeding, digestion and weather, water temperature, water quality conditions in the appropriate amount of casting. The general daily feeding amount is 1.5% to 2.5% of the eel's body weight, and it is appropriate to finish it within 12 hours. Timing: i.e., fish size is small, high density, daily at 8:00 a.m., 4:00 p.m. around 1 feeding; eel specifications in more than 100 grams, daily at 8:00 a.m. ~ 9:00 a.m. to feed 1 time can be. Positioning: that is, the feed is put on a fixed food table, every 1000 square meters of soil pool can be set up 2 to 3 food table. Four, daily management and disease prevention Every morning and evening, inspect the pool, observe the eel activities and feeding conditions, after the rain to check the drainage, etc., to prevent the escape of fish. Normally every 10 days ~ 15 days to refill the new water 1 time, summer and fall every 5 days ~ 7 days 1 time, each time the amount of water for the whole pool of about 10%. At the same time, pay attention to make the ph value between 7 ~ 8.5, ph value is too high should be replaced with new water, too low every 1000 square meters with 15 kilograms ~ 20 kilograms of quicklime adjustment.
Warm water aquaculture
Warm water eel farming is currently a more advanced farming method. It is required to control the water temperature at the optimal water temperature for eels (27℃ up and down) and to carry out running water culture. The advantage is that the eel has fewer diseases, faster growth and higher yields. Generally released in early February, the year can be raised into all edible eel, mu yield of about 15,000 kg. The disadvantage is that the infrastructure investment is larger, breeding technology is strong. This type of culture can be divided into two types: factory waste heat warm drainage culture and indoor circulating filtration culture due to different water sources. The former uses factory waste heat and warm water, can save energy, the structure is simpler, the breeding cost is lower; the latter use boiler heating, pool water recycling, need to build biological filtration tank, the structure is more complex, one-time investment is larger. Waste heat warm water eel farming are required to utilize the topographic elevation as much as possible to build eel ponds, so that they can be automatically injected and drained. Because the pool water is discharged immediately after use, it is generally operated in the open air. The main facilities include cold water and hot water pipes, temperature control pools, eel ponds, and drainage pipes. Circulating filter eel farms are generally operated indoors and are equipped with biological filtration tanks. The size of warm running water eel farm is usually 1-2 acres. Each pool is a concrete structure, with an area of 30-50 square meters, a depth of 1.2-1.4 meters, and a water storage of 1.0-1.2 meters. Pool was round or square excision four corners, round pool pool bottom was pot bottom shape, the drainage outlet in the center of the pool bottom, by two semi-circular drainage pier and pier on both sides of the three gates. The bottom of the square pool is flat walled and tilted to the drainage outlet. Other equipment requirements and feeding management methods are generally the same as the open pool.