Techniques of artificial propagation and fry cultivation of Monopterus albus

First of all: inducing spawning and hatching

1. Stimulating spawning

(1) After the water temperature reaches 25-28℃, inject chorionic gonadotropin solution into the parent eel (in order to induce spawning), and the injection amount of each female eel is generally 4-5 international. Generally, intraperitoneal injection is the best injection method, which not only has a good effect, but also has a short effect time.

(2) After the drug is injected, the female parent eel and the male parent eel are put into the spawning pond according to the ratio of 2: 1 or 3: 1. Generally, the female parent eel can produce eggs (or extrude eggs) by itself after 45-5 hours.

(3) If artificial insemination is needed, the eggs of female eels should be collected in advance (by squeezing eggs or laparotomy), and then the male eels should be dissected to take out their semen before dry insemination.

2. Hatching management

(1) The hatching water temperature of eggs is generally 22-28℃. In a suitable temperature range, the hatching rate will increase with the increase of temperature. If the water temperature is about 25℃, it usually takes about 15 hours (7-8 days) to hatch, and the body length of newly hatched eel seedlings is generally 12-2 mm.

(2) After 3-4 days of incubation, the eel seedlings can be put into the nursery pond for cultivation. It should be noted that the water temperature difference between the incubation pond and the nursery pond should not exceed 3-5℃.

Secondly: fry cultivation

1. Put eel fry into a nursery pond, and feed zooplankton such as cladocera, copepods and some large rotifers after their yolk sacs slowly disappear (about 7 days), then mix cooked egg yolk and soybean meal into paste and feed, or process the blood and leftovers of mussels, earthworms and various animals into paste.

2. The feeding frequency is 4-6 times/day, and the daily feeding amount is 2-5% of the weight of eel fry. If the stocking amount is 45-5 per square meter, 2-4 standard eel species can be harvested in winter.

the third water quality adjustment

1. Although eel seedlings have strong sewage resistance, hypoxia resistance and disease resistance, if intensive culture is carried out with high density, attention should be paid to adjusting the water quality. Generally, water can be injected once a week or flushed once, and the amount of water exchanged each time is 1/3 of the total pool water.

2. After entering summer, we can plant turnip, mushroom, water bamboo or water peanut in the nursery pond to provide shade for Monopterus albus.

3. A proper amount of loach seedlings can be put in the nursery pond, generally 3-5 eels can be put in each square meter, which can not only clean up the leftover food eaten by the eels, but also regulate the water quality and prevent the eels from intertwining with each other.