The key to successful rice field eel farming is good management

To improve the survival rate of eel farming and ensure success, in addition to proper stocking of eel fry and the freshness of bait, the management of five key links must also be done well:
1. Water quality management. Keeping the pond clean and the pH moderate is a necessary condition for accelerating the growth of rice field eels. In eel farming production, water quality management should be strengthened in three aspects: First, maintain an appropriate water level. Shallow water easily leads to water quality deterioration, causing rice field eels to stop eating and suffer from various diseases; second, insist on frequent water changes. Under normal circumstances, water should be changed once every 3—5 days, and in midsummer it is best to change the water once every 1—2 days. The newly added water, especially well water, should be pumped into a storage tank one day in advance so that the water temperature can be adjusted to be close to that of the pond water, and the temperature difference must not exceed 3℃; third, promptly remove leftover food. 3.4 hours after each feeding, the remaining bait should be removed with a fine mesh scoop. Especially in midsummer when temperatures are high, to prevent leftover bait from fermenting and causing a large proliferation of pathogenic microorganisms, quicklime water must also be splashed into the pond or net cage once a week to kill pathogens and regulate the acid-base balance of the water body.
2. Substrate management. Many farmers' rice field eels often get sick and grow slowly, and one of the most important reasons is that there is a problem with the substrate of the eel pond. For eel farming, it is best to directly use crushed yellow clay to line the bottom of the pond. Never directly scoop up black silt from rivers and ponds as the substrate, because it is highly fertile and full of pathogens, and rice field eels are extremely prone to infection and disease. If river or pond mud is used as the substrate, it should first be scooped out and spread out to dry for 3.5 days, then spread into the bottom of the pond after it becomes loose, and then pond water should be added. For diseased eel ponds, the silt at the bottom of the pond must be thoroughly removed and replaced with sun-exposed river or pond mud, so as to completely eliminate bacterial reproduction. If net cages are used for eel farming, sun-exposed river or pond mud should likewise be used as the bottom mud, with a thickness of 10—15 cm.
3. Feeding management. In the wild environment, eel fry are low in density, have a wide range of activity, and forage for themselves, so for the first few days after stocking they basically do not eat artificially supplied feed or eat very little, and must be domesticated. The specific domestication method is as follows: do not feed for 3 days after stocking the eel fry, so that all food in the bodies of the eel fry is digested and they become empty-stomached, putting them in a state of hunger. Then feed them at night with earthworms, which rice field eels like to eat, along with chopped small miscellaneous fish and animal offal. The feeding amount should be controlled within 1% of the weight of the eel fry. After 3 days, when it is observed that the rice field eels are feeding vigorously, switch to fixed-point feeding, generally setting 3—4 points per box (14 sq m). If artificially constructed ponds are used for eel farming, set 5-6 points.
4. Seasonal management. The focus is on the management of the three seasons of summer, autumn, and winter: First, do a good job of preventing summer heat. As the saying goes: “After the sixth month, rice field eels turn into gold bricks.” In summer, climbing plants such as pumpkin, loofah, hyacinth bean, and grape can be planted around the pond, or a shed can be built with rice straw for shade. Appropriate amounts of floating plants such as water hyacinth, water lettuce, and duckweed can also be placed on the water surface of the eel pond for shade, and the cooling effect is very good; second, do a good job of fattening in autumn. The early part of autumn is the golden stage for the growth and fattening of rice field eels. During this period, try to feed fresh bait with comprehensive nutrition to make nutritional reserves for preparing to enter the winter period. In addition, as the temperature continues to drop in late autumn, a tall artificial warming shed can be built above the eel pond with transparent plastic film, which can ensure normal light and extend the growth period by about one month, and this has a very significant effect on achieving high yields of rice field eels; third, ensure safe overwintering. Every year in November, when the temperature drops below 10°C, rice field eels stop feeding and enter dormancy. For rice field eels that do not reach market size that year or are prepared to be held over until the Spring Festival when prices are high, safe overwintering measures should be taken in time: First, dry pond overwintering. After the rice field eels stop eating, drain the pond water and cover it with 15—20 cm thick grass bags or crop straw, etc., keeping the bottom mud moist and unfrozen. The covering material should not be piled too densely, to prevent the rice field eels from suffocating to death; second, deep water overwintering. That is, before the rice field eels enter the overwintering period, raise the pond water to about 1 m and let them burrow into the underwater soil to hibernate. During overwintering, if the pond water freezes, manually break the ice in time to prevent ice sealing from causing oxygen deficiency in the eel pond.
5. Disease prevention management. In rice field eel farming, disease prevention has always been a major problem. This is because rice field eels have no scales on their body surface and are susceptible to invasion by pathogenic bacteria and parasites. In addition, rice field eels are sensitive to a few drugs, and there are not many special effective drugs, so in production, ecological prevention should be the main approach, such as strictly disinfecting and filtering aquaculture water, stocking toads in eel ponds, reducing human injury, and so on. In normal times, if diseased eels are seen, they should be promptly scooped out and isolated, the cause should be identified, and the right medicine should be applied.