The technique of raising eel in soil ponds

Eel, also known as eel, dolphin, etc., is a valuable fish in freshwater culture. It has delicate meat, delicious taste and high nutritional value. it has medicinal effects such as removing blood stasis and giving birth to new, nourishing and nourishing. The eel grows rapidly and has strong adaptability. It can live normally even in the waters where there is little dissolved oxygen and other fish can not live. The technical requirements of artificial culture are not high and the sources of feed are wide. In recent years, a large number of farmers have carried out eel culture in soil ponds, all of which have achieved high yield and high efficiency. Eel species put in early spring can be put on the market at the end of autumn and the beginning of winter, generally yielding 800kg ~ 1000 kg per mu. The key points of high-yield and high-efficiency culture of eel in soil pond are introduced as follows:

Pond selection and disinfection

The soil ponds where eels are farmed should be ventilated and sunny, with sufficient water sources, and the area should not be too large. Plant 0.8-1 meter wide water lotus or water peanuts around the soil ponds and fence them with fences or nets, which can not only prevent the eel from escaping, but also shade and benefit its growth.

Before stocking, the excessive silt in the land should be dug out, the bottom of the pond should be leveled, the ridge of the pond and the inlet and outlet of the pond should be repaired, and the pool should be disinfected with 100kg ~ 125kg quicklime every 1000 square meters before the eel is planted in the pond, so as to kill wild miscellaneous fish and enemy pests thoroughly. Then 0.6 ~ 0.7 meters of water was injected into the eel pond 5 ~ 7 days before the eel was planted, and the inlet was filtered with a 60-mesh sieve. Finally, base fertilizer is applied, generally every 1000 square meters, 300kg ~ 400kg of rotten pig and cow manure are sprinkled, and eel species are released after the water is light green or yellowish brown, so that sufficient natural bait can be eaten after entering the pond. The pool will be deepened to 1.5 meters in about 15 days.

II. Treatment and release of eel species

The suitable temperature for eel growth is 20 ℃ ~ 28 ℃, and the water temperature begins to feed at 12 ℃, so the feeding time is generally from late February to mid-March. Before release, the eel seed bag was soaked in water for 20 ~ 30 minutes to adapt to the water temperature. The bag can only be removed when the temperature difference inside and outside the bag is less than 5 ℃, and then 2 ~ 3 basins of water are poured into the bag with a small basin to make the eel species gradually adapt to the low dissolved oxygen state from the state of high dissolved oxygen. At the same time, eel species should be sterilized before release, and eel seeds should be soaked with 0.75 kg ~ 1 kg salt for 15 ~ 20 minutes.

The eel species released should be bluish gray, full of skin, flexible and active in swimming, and should be neatly consistent with the pond eel species, otherwise the food intake of the weak will be affected by the competition among eels. The stocking density is generally 4000 ~ 5000 eels of about 20 grams per 1000 square meters, 3000 ~ 4000 eels of about 50 grams and 2000 ~ 3000 eels of about 100g. At the same time, 50 bighead carp, 30 silver carp and 200 tilapia can be cultured in every 1000 square meter soil pond. on the one hand, they can filter and feed on plankton, clean the feces excreted by eels and purify water quality; on the other hand, it can increase fish production.

III. Types of feed and feeding

Artificial breeding of eel mainly depends on special compound feed (available on the market), and every 50 kg of special feed is supplemented with 50g ~ 60g of vitamin a, b, c, e and 1.5kg ~ 2kg of cod liver oil (cod liver oil should be stopped when the water temperature is below 20 ℃ or above 35 ℃). Young eel should be added less, adult eel should be added more. If there is a temporary lack of special feed, it can be replaced by minced flour of animal feed such as small miscellaneous fish, viscera of livestock and poultry, silkworm pupa, and its crude protein content must be more than 40%.

Eel is a carnivorous fish, gluttonous. When feeding, we should implement the principle of "four determinations", that is, quality, quantity, timing and positioning. Quality determination: that is to ensure the quality of feed. The prepared feed should be moderate in softness and hardness (1.2 ~ 1.3 times the amount of water added), fresh and clean, and should not deteriorate. Quantitative: that is, the feeding amount should be appropriate according to the specification, feeding, digestion, weather, water temperature and water quality of the eel. Generally, the daily feed intake is 1.5%-2.5% of the body weight of eels, and it is appropriate to finish eating within 12 hours. Timing: that is, fish with small size and high density should be fed once at 8: 00 am and 4: 00 pm every day, and eel should be fed once at 8: 00 am ~ 9: 00 am every day. Positioning: that is, feed is put on a fixed table, and 2 ~ 3 tables can be set up in every 1000 square meters of soil pond.

Daily management and disease prevention

Patrol the pond every morning and evening to observe the eel's activity and feeding, and check the drain after rain to prevent escaping fish. At ordinary times, fresh water is injected once every 10 days to 15 days, and once every 5 days to 7 days in summer and autumn, and the amount of water changed each time is about 10% of the whole pool. At the same time, pay attention to make the ph value between 7 and 8.5, if the ph value is too high, it should be replaced with new water, and if it is too low, it should be adjusted with 15 kg ~ 20 kg quicklime per 1000 square meters.