Is cement pond farming good for yellow eel? What are the technical points?

The yellow eel (Monopterus albus) has excellent biological characteristics for farming, such as tolerance to low oxygen, strong vitality, omnivorous feeding habits, and a low-dwelling habit in shallow water. It is suitable for many intensive farming methods such as backyard farming, pond farming, rice paddy farming, cage farming, and industrial farming. So is cement pond farming good for yellow eel? What are the technical points?

1. What are the advantages and disadvantages of cement pond farming of yellow eel?

1. The main advantages of cement pond farming of yellow eel are:

Water changes and sludge removal are thorough, and the water body lasts a long time;

(2) Spraying liquid medicine leaves no dead corners, giving good disease prevention and control results;

(3) In low-temperature seasons, the water temperature in cement ponds is often higher than in earthen ponds, which helps extend the feeding period of the yellow eel, resulting in a larger feed intake and faster growth over the same period;

(4) Long service life; once the pond is built, it can be used for more than ten years or even several decades;

(5) Easy to observe, and operations such as harvesting require little physical labor.

2. The disadvantages of cement pond farming of yellow eel are: the investment in building the pond is relatively large; its buffering capacity for temperature is smaller than that of a mud pond. In summer, measures such as partial shading must be used to keep the pond water within a safe range.

2. Key technical points for cement pond farming of yellow eel

1. Pond preparation: For a large-scale farm, it is best to equip the full set of facilities for the entire farming process, from breeding to yellow eel fry rearing and grow-out. Therefore, a spawning pond, hatching pond, fry rearing pond, and adult yellow eel farming pond should be provided. The spawning pond is generally 5-10 sq m, the hatching pond 2-10 sq m, the fry rearing pond 3-10 sq m, and the adult yellow eel pond more than 10 sq m; the inner walls of the ponds are required to be smooth. New ponds must be de-alkalized, which can be done by repeatedly soaking with water for half a month (completely changing the water once every two days) or by treatment with acetic acid; except for the hatching pond, all other cement ponds must be equipped with anti-escape facilities; it is best to install bottom aeration facilities.

2. Fry rearing in the fry rearing pond: Bricks, tiles, and rubble can be laid on the pond bottom, followed by routine disinfection and water quality cultivation; newly hatched yellow eel fry can be stocked at 3000-5000 fish per sq m, and they must be divided into other ponds in time afterward. At about 175px, they can be raised at 100-200 fish per sq m until the end of the year; at the start of feeding, it is best to feed them tubifex worms and rotifers and cladocerans, or use the soybean milk cultivation method to start feeding; after about 15-30 d, train them to feed at a fixed point and set up feeding trays, and gradually replace the bait with artificial feed (mainly earthworms, housefly maggots, small trash fish, snail and mussel meat, and animal viscera, which can be paired with some rice, noodles, melon and fruit peels, etc.). Strengthen daily pond patrols and water quality management, and at the same time apply bottom-improving and water-purifying products according to the water quality and water color, and promptly prevent and treat fish diseases.

3. Adult yellow eel farming: Lay 30-1000px of soil on the bottom of the yellow eel pond and plant aquatic plants such as arrowhead and alligator weed; before stocking, dissolve 0.2 kg per sq m of quicklime and splash it over the whole pond for disinfection; after 3 d, organic fertilizer can be applied; after 7 d, stock disinfected yellow eel fingerlings at 100-200 fish per sq m (20-30 g per fish). After feeding training, 1-2 toads per pond and loaches at 0.1-0.2 kg per sq m can be placed in, and some snails and small trash fish can also be placed in. Set up feeding trays and feed in the evening mainly with feed composed of earthworms, housefly maggots, small trash fish, snail and mussel meat, silkworm pupae, and animal viscera paired with some rice, noodles, melon and fruit peels, etc., or with special compound feed for yellow eel. Adhere to the “four fixed” principles; black light lamps can also be set up in the pond to attract insects, and pig blood etc. can be used to attract flies to lay eggs and produce maggots for the yellow eel to eat; strengthen daily pond patrols and water quality management, frequently (7-15 d) apply live bacteria preparations, and at the same time apply bottom-improving and water-purifying products according to the water quality and water color, and promptly prevent and treat fish diseases.

4. Cement ponds must pay attention to temperature control: During high summer temperatures, stock some water hyacinth, water lettuce, or duckweed on the water surface, with the area controlled below 2/3; melon trellises and the like can also be built over the pond for shade and cooling, and they must be removed promptly when the water temperature drops in autumn.

5. Harvesting: Generally in late November, yellow eel cages can be used for harvesting, with earthworms placed inside, set in the evening and collected in the morning, and the yellow eels are gradually caught out; the pond water can also be drained and the mud turned over to catch them; catching yellow eel fingerlings requires even more care; when dividing into ponds, do not injure them, or promptly remove any injured fingerlings.

6. New large-scale yellow eel cement ponds should develop in the direction of industrialization: In particular, when selecting a site, the characteristics of the yellow eel must be fully taken into account. The site should be chosen in a relatively quiet place with sufficient, pollution-free water, and corresponding supporting facilities should be established, such as a water storage pond and bait breeding sites (such as for earthworms and yellow mealworms).

3. How can a yellow eel farm add anti-escape facilities?

To prevent losses caused by yellow eels escaping from the pond, it is necessary for us to add two more barrier nets at the end of the drainage ditch. Generally, steel wire mesh with a mesh diameter of no more than 0.5 cm is selected, supported with iron sheets or wooden strips to make mesh panels, and installed and fixed in the drainage ditch. The purpose of installing two barrier nets is mainly to ensure that if the first net is blocked by debris, there is still a second barrier net that can effectively prevent them from escaping.

4. How can the alkalinity of a newly built cement pond be eliminated?

Because a large amount of cement is used in a newly built cement pond, its alkalinity is very high. If measures are not taken to remove it, directly putting yellow eels in may lead to “total annihilation.” To eliminate alkalinity, the water immersion method is generally used, that is, fill the pond with water and soak for 7-10 days, then drain the pond water and it is ready for use. If it is urgently needed, 0.5 kg of edible vinegar or 10 ml of glacial acetic acid can also be splashed in per 1 cubic meter of pond water, and then it can be used after soaking for 1 day.