Ecological Propagation techniques of cultivated Monopterus Albus

1. Accelerated ripening and spawning of parent eel: after late May, when the water temperature reached 25 ℃, each parent eel was injected with LRH-A (luteinizing hormone-releasing hormone) 12.5 micrograms and 0.5ml to promote gonadal maturation. Seven days later, the parent eel was injected with 0.5ml DOM (diosterone) 0.5ml or LRH-A+HCG (luteinizing hormone releasing hormone + chorionic gonadotropin) 0.5mg + 3 international unit, 0.5ml to induce parturition.

2. the release density of parent eel should be 1: 2 per square meter, and the density should not be too high. 3. Feeding and management of parent eel: after the parent eel enters the pond, the water level can be properly raised and kept at about 50 cm to prevent the sharp rise of water temperature during the day, which is not conducive to the gonadal development of Monopterus Albus. Generally, there is no need to feed for the first 2 days, and after the third day, a small number of earthworms are fed to facilitate food attraction, then artificial feed (feed during production and breeding) can be put into the feeding table at the edge of the water inlet, so that the feed breath can spread all over the pond with the current to attract parent eel to eat, which lasts for several days until eating is normal. It is better to have micro-running water in the breeding pond to keep the water quality fresh and keep the rice field eel in good water quality and water temperature. The water inlet is filtered with 40-mesh sieve silk to prevent the entry of enemy organisms. 4. Spawning period management: pay close attention to the emergence of bubble nests in the breeding pond. Once the bubble nests are formed, it means that the female eel will lay eggs in about 3 days. During this period, the environment should be kept quiet and feeding should be reduced. During this period, it can be seen that there are two rice field eel probes breathing at the mouth of the eel cave. If other male eels approach, the original male eel in the cave will suddenly attack. Generally speaking, the offender will no longer attack and retreat. If only one Monopterus Albus probe is found to breathe at the mouth of the cave, it is proved that the female eel has laid eggs and left, leaving only the male eel to guard. Experiments show that the sperm love rate of this ecological reproduction can reach more than 85%. 5. Hatching management of fertilized eggs: once a foam nest with fertilized eggs is found in the breeding pond, the young eel will hatch after 5-7 days. At this time, the hatching water temperature should be kept at 25: 28 ℃, and some aquatic plants should be properly placed in the hatching pond so that the young eel can hide and perch, and it is also convenient for the collection of the young eel in the future. Experiments show that the natural hatching rate can reach 80%. 6. The fishing and cultivation of eel: the eel can be fished to the eel seedling culture pond within 5 days after hatching. The water temperature in the eel seedling culture pond was the same as that in the incubation pond (the difference was less than 2 ℃). The small net bag made of fine gauze should move quickly so as not to affect the seedling fishing due to the attack of the eel. The eel seedlings harvested were cultivated in a special pond. After hatching for a week, when the yolk sac disappears, you can feed some boiled egg yolks or water fleas, and then feed silk earthworms, fly maggots and chopped earthworms, snails and mussels. The parent eel that has laid eggs should also be carefully cultivated, and the second spawning can be carried out after about 15 or 20 days.