CATDOLL : CATDOLL: How to artificially breed eels

1. Construction of eel pond 1. The area of ​​cement pond should be 30-50 square meters. The surface and bottom of the pond should be polished to prevent eels from scratching their skin and causing infection with various bacteria and viruses. The top of the pond should be about 30 cm above the water level, and a natural overflow outlet should be set. The outlet should be fixed with a mesh to prevent eels from escaping. There are two ways to raise eels in cement ponds: with soil and without soil. Both methods require planting water peanuts or water hyacinths to regulate water temperature and provide rest for eels in hot seasons. The entire pond can be planted with only a small part of the feeding port. If it is soil culture, it is appropriate to lay 20 cm to 30 cm of soil, and the water level above the mud layer should be maintained at 20 cm to 25 cm. If the water is too deep, the eels will consume too much energy in their activities. If it is too shallow, the water body will be turbid and the water temperature will change greatly. If it is soilless culture, the water level should be maintained at 30 cm to 40 cm. The advantage of this culture mode is that the water body disinfection effect is good, while in soil culture, it is difficult for the disinfection drug to act on the soil and the bottom, and it is easy to breed various parasites and their intermediate hosts, such as leeches, flat leaf snails, and lymna. 2. Rice field culture First dig up the soil in the rice field, bury the net cage, and then put the soil back into the net cage, fix the four corners of the net cage, and plant water peanuts or water hyacinths. The area should be 20 square meters to 30 square meters. It is not suitable to plant crops with rough and developed root systems such as rice in the net cage, because eels have the habit of drilling soil and easily scratch the epidermis. 3. All kinds of ponds, lakes, and reservoirs are used for net farming, that is, cage soilless farming. The area should be 15 to 20 square meters, which is convenient for disinfection and treatment. When the disease occurs, the cage and the fish can be directly placed in a large disinfection container. Water plants such as water peanuts or water hyacinths should also be cultivated in the cage for eels to rest. The area of ​​the above various breeding modes should not be too large. If it is too large, it will easily cause the size difference of eels to increase during the breeding process, which is not conducive to growth. 2. The selection of species should be yellow eels with large and dense black spots. This kind of eel grows the fastest; yellow eels with small and irregular spots grow generally; yellow and black eels grow slowly; and black or blue-black eels grow the slowest, but this kind of seedling is relatively fierce. When selecting seedlings, you should be careful not to choose seedlings that are injured, electrocuted, fished, or trapped, but choose healthy, energetic seedlings that have strong ability to swim against the current and react quickly when their tails are gently touched. When selecting seeds, you should choose seedlings of the same size, because eels cannibalize each other, which is very likely to happen when there is not enough bait. 3. The impact of water temperature and pH value on eels Yellow eels are very sensitive to changes in water temperature. The suitable water temperature for growth is 15℃~30℃. At 28℃, they are most active, grow fast, and have a high bait utilization rate. During this period, pay attention to feeding the eels to make sure they are full. When the water temperature is below 15℃, yellow eels will not eat and will enter a hibernation state. Therefore, in the northern part of the Yangtze River, when the water temperature is unstable in April, do not add water to the pond or feed the eels to lure them out of the hole, so as to avoid large changes in water temperature causing eel diseases. Eels can use the wet method to hibernate, which is: drain the water first, keep the soil moist, add a layer of straw or hay to keep warm when it is cold or snowing, and prevent ice from forming; deep water hibernation can also be used, but there is a disadvantage, when the weather warms up in the second year, the eels will be more active and will come out of the cave to look for food, but this method is not stable at this time, and the eels are prone to colds and other diseases. pH value is also called acidity and alkalinity. During the breeding process, if the dissolved oxygen is insufficient, the oxidation process is inhibited, the bait residue, organic matter, excrement, etc. gradually accumulate, and the decomposition is insufficient, organic acid will accumulate and the pH value will drop, affecting the growth of eels. Therefore, in the breeding process, attention should be paid to changing fresh and clean water. Because eels like clean water quality, attention should be paid to changing water and measuring pH value frequently. Eels are generally suitable for living in neutral or weakly acidic waters (pH value between 6.5 and 7.2). When changing water, attention should be paid to weather and water temperature. Each time the water is changed, 3 cm to 5 cm is appropriate. It is advisable to slowly put in fresh water and then slowly discharge old water. The same treatment should be applied during the disease season. Changing water too quickly can easily cause a large temperature difference, which can cause eels to catch a cold. 4. Fish pond management 1. Disinfection of fish ponds before stocking fry. The disinfection time should be set about 10 days before stocking fry, because if it is too late, there may be residual poison in the fish pond, and if it is too early, it is easy to breed bacteria again. During disinfection, the pond water should be kept at 5 cm to 6 cm high, and 90 g/m2 to 120 g/m2 of quicklime should be used for disinfection. The next day after disinfection, it is best to stir the mud and lime milk with a rake to make it fully effective. During disinfection, new water should be added every 1 to 2 days and old water should be discharged. 2. Disinfection and stocking of fry Before stocking, in order to determine whether there are residual poisons in the fish pond, 5 cm to 10 cm bighead carp or silver carp fry can be used as "test water fish" at a rate of 2 to 3 fish/m2. If the fish activities are normal, the toxicity has disappeared, otherwise the stocking should be postponed. Before stocking, the fry should be disinfected by immersing them in 3% to 5% salt for 10 minutes to 15 minutes, or 2ppm to 5ppm potassium permanganate, which can eliminate some pathogens and parasites and increase disease resistance. It is best to disinfect in a cool place to avoid exposure to sunlight. The time can be appropriately increased or decreased depending on the physique of the eel fry to see if the fry is abnormal. After disinfection, put them in clean water for temporary breeding in preparation for stocking. When stocking, they should be divided into ponds according to size to avoid killing each other. It should also be noted that the water temperature of the temporary breeding pond should be equivalent to the water temperature of the large fish pond (i.e. the stocking pond). The temperature difference between the two should not be greater than 3°C. If the difference is large, the water temperature should be adjusted appropriately. 3. Feeding management and growth: Add some new water about a week after the eel is put into the pond. Add water once every 2 to 3 days, and each time 3 cm to 5 cm is appropriate. Keep the water level at about 25 cm. When it is hot in summer, the number of water changes can be appropriately increased, and each time 3 cm to 5 cm is appropriate to avoid excessive temperature differences. Patrol the pond every day, and remove sick eels in time to analyze the cause of the disease (sick fish generally do not enter the hole and float on the water surface). Adhere to intensive breeding, and feed at regular times, fixed points, fixed quality, and fixed quantities. For disease prevention, 1PPM bleaching powder or 0.2PPM trichlorfon can be used to spray the entire pond (90% crystal type). Disease prevention drugs should be prepared in several varieties and replaced frequently to prevent pathogens from developing drug resistance. The growth rate of eels has a lot to do with the nutritional components, types, and quality of bait. In traditional breeding, small fish, shrimps, earthworms, river clams, snails, etc. are used, and the freshness is difficult to guarantee. Eels are prone to sour and deterioration. The nutrients are relatively single, basically based on protein, and the protein content of these introduced wild fish is not high. The digestive organs of eels are weak, not easy to sour and deteriorate, and eels are prone to disease. The nutrients are relatively single, basically based on protein, and the protein content of these wild fish is not high. The digestive organs of eels are weak, not easy to digest and absorb, and are not suitable for the growth requirements of eels. In particular, fresh ice fish and clams are more difficult to digest and absorb, and are very likely to cause enteritis. Feeding earthworms is prone to various parasitic diseases. Because earthworms live in moist and fertile soil, and various parasites also like to reproduce and lay eggs in this environment, earthworms have become an indirect infection of eels. In order to improve economic benefits, larger eel seedlings should be selected to achieve the purpose of listing in the same year. Therefore, eels should be fed with complete and easy-to-digest and absorb complete feed. There are three types of eel compound feeds on the market, namely powder, granular and expanded feed. Powder and granular feeds inevitably have the disadvantages of easy loss, water pollution, and difficulty in observing feeding conditions. Expanded feed has good floating properties, high stability in water, light water pollution, and easy observation of feeding conditions. In addition, expanded feed is sterilized at high temperature during the expansion process and does not carry pathogens. It is the first choice in breeding feed. Farmers should choose good feed manufacturers and well-known brands to ensure product quality. At present, the "Yinxiang" and "Fuxing" brand eel expanded feeds on the market have been recognized by the majority of farmers. V. Main diseases and their treatment 1. The cause of hemorrhagic disease is unknown, and it is a septicemic disease. Eels fed with earthworms are more likely to develop this disease because parasitic diseases are very likely to cause hemorrhagic disease and enteritis. (1) Symptoms: There is bloody liquid in the mouth, which will flow out when the fish is turned upside down, and it is more obvious after death. The body surface is covered with bleeding spots of varying sizes, especially on the abdomen. The anus is red and swollen, and the fish is bleeding. The sick fish often floats to the surface to take a deep breath. Local farmers in Hubei call it "vertical piles". They keep turning in circles. When the belly is cut open, it can be seen that the liver is hemorrhagic and enlarged, the spleen is enlarged and purple, and the rectum is bleeding. (2) Treatment A. Spray the whole pond with furazolidone 0.2ppm~0.35ppm (using furazolidone original powder). B. Take 5g of norfloxacin/100kg of fish orally and mix it with feed. C. Soak tobacco leaves in 250g of warm water at a depth of 30cm/mu for 5~8 hours and spray it all over the pond. D. Soak the sick eels in 250,000 units of erythromycin. A and B above can be used at the same time, and A and C can be used alternately every other day for 3 to 5 consecutive days. 2. Red skin disease (1) Symptoms: The diseased fish moves slowly and weakly, sticks its head out of the water all day, has local bleeding and inflammation, has red patches, mostly on the abdomen, has severe epidermal rot, and has intestinal congestion and inflammation. The difference from hemorrhagic disease is that it does not circle. (2) Treatment A. Spray 1ppm bleach solution throughout the pond for 3 consecutive days. B. Soak the diseased eels in erythromycin. 3. Enteritis is mainly caused by feeding rotten and spoiled ice fish clams or due to insufficient feeding and excessive hunger. (1) Symptoms: slow movement, no feeding, dark blue body color, weight loss, intestinal congestion, yellow mucus flowing out, red and swollen anus, and severe purple. (2) Treatment: Usually use 5 kg of allicin or hot pepper for every 100 kg of fish for prevention. Add 3 kg to 4 kg of mint to every 100 kg of eels and boil water and spray once every 7 to 10 days. For treatment, use the following for every 100 kg of fish: A. 20 ml of Ten Drops of Water for Human Use mixed with feed. B. 10 g of sulfamethoxazole mixed with feed for 3 days. C. 5 g of norfloxacin mixed with feed for 3 to 5 days. 4. Most of the worms that feed earthworms will be infected with capillaries and acanthocephala. They are white, elongated worms that can easily cause enteritis. (1) Treatment: A. 90% crystal trichlorfon 0.5ppm to 0.7ppm solution is sprayed throughout the pond. When spraying, sufficient water should be prepared. Eels are very sensitive to trichlorfon. If the dosage is not appropriate, the entire pond will die. Trichlorfon is forbidden to be taken orally. B. For every 50 kg of eels, take 5 to 7.5 g of levamisole orally for 6 days or the same amount of albendazole. C. Copper sulfate + ferrous sulfate (5:2) 0.7ppm mixture is sprayed throughout the pond to kill parasites. 5. Trypanosomiasis can easily cause anemia and enlarged heads. The same medication as (4) can be used for soaking. 6. Tail rot is mainly caused by insufficient bait, cannibalism or self-mutilation by the same species. Catch the fish and wash them with erythromycin or sprinkle them with 1ppm bleach. 7. Coma is mainly caused by hot weather, high temperature and shallow water. You can add some clean water and chop fresh clam meat into pieces and sprinkle it into the pond, or chop fresh gourd and sprinkle it. 8. The water temperature of a cold is either high or low, or a sudden large amount of water change can cause fish dysfunction and death. Maintain the water level and change the water reasonably. 9. Fever is mainly caused by high density, hot weather, excessive fish secretions in the water, oxygen consumption, unclean water quality, and bait residues or small fish and clam meat that have not been eaten and not caught, which makes them smelly. Prevention and control methods include A changing the water; B spraying 0.7ppm ketone sulfate or 300,000 units of penicillin on 25 kg of water.