Artificial breeding technique of Monopterus Albus

In recent years, the phenomenon that the supply of Monopterus Albus falls short of the demand still exists. The supply and demand of wild Monopterus Albus falls far short of the market demand, and solid artificial breeding of Monopterus Albus flourishes. Although the large-scale reproduction technology of eel is not yet fully mature, when the general farmers raise eel in the yard, as long as they master the artificial breeding technology of Monopterus Albus, they can achieve self-supply of seedlings and reduce the cost and risk of breeding.

Parent eel selection

The female eel should be about 20cm, and the bigger the male is, the better. the color should be yellowish brown or bluish gray, and the ratio of male to female is 1: (2: 3). After disinfection, the eel is preserved. The area of the storage pond is about 20 square meters, the water depth is 20 to 25 centimeters, and some aquatic plants such as water hyacinth and water peanuts are planted. The stocking density of female eel is 7 strips / square meter, and the stocking density of male eel is 2 / 3 strips / square meter. The bait is mainly live food, and the fixed point (food table) and fixed time are achieved. The water is changed once every 5-7 days, and the storage time is at least 1 month.

Breeding material

2 mortar, 1 medical syringe 2 ml, 1 5 ml each, several needles (4-5), one pair of scissors and tweezers each, 0.7% saline, several towels or gauze, several water basins (buckets), several hard feathers, Ren's solution (1 liter of distilled water dissolved into NaCL7.5 g, KCL 0.2 g, CaCL 20.4 g).

Artificial induced labor

1. Dosage of oxytocin: luteinizing hormone releasing hormone analogue (LRH-A) at a dose of 0.1 μ g / g body weight is suitable. Chorionic gonadotropin (HCG) at a dose of 1mg / g body weight is an effective range for ovulation induction, but it is most suitable for ovulation induction with 2: 3 international unit / g body weight.

2. Preparation of oxytocin: both LRH-An and HCG are white crystals, which are fully dissolved in normal saline solution. The dose is accurately calculated according to LRH-A0.3 microgram / gram body weight + HCG2~3 international unit / gram body weight and inhaled into the syringe. The injection volume of each parent eel should be 0.5 ml, not more than 1 ml. The injection should be used with you and should not be kept for too long. After the first injection, the remaining liquid can be placed in the refrigerator and can be reused when the next injection is given.

3. Oxytocin injection: use 5 × 10 ml medical syringe, 4 # 6 needle, the syringe should be boiled and sterilized for 10 minutes or disinfected with alcohol. During the injection, two people should cooperate. One person holds the rice field eel with a towel or gauze to make the abdomen face up, cushion the eel with a towel below, fix the eel with both hands, and the other person dries the water at the injection site. The needle is placed in the direction of the eel head, at an angle of 45 to 60 degrees with the fish body, and the needle is pierced into the abdominal cavity at a depth of no more than 0.5 cm. The injection is slowly pushed into the abdominal cavity of the eel, and when the needle is pulled out, it is pressed on the needle eye with an alcohol cotton ball. Gently rub to prevent the injection from flowing out. The needle should not be inserted too deep to avoid stabbing the internal organs, but it should not be too shallow, otherwise the liquid cannot enter the abdominal cavity.

Pool temporary cultivation

After hormone injection, the eels were temporarily reared in a pool with a water depth of 20cm to 30cm. The females and males should be separated, and the water should be changed once a day. When the water was less than 25 ℃, the eels were examined 40 hours later, once every 3 hours, until about 75 hours (the effect time was different). The examination method is to touch its abdomen with the hand and move back and forth. If there is a feeling of egg dissociation, it can ovulate and carry out artificial fertilization.

Artificial insemination

Take out the female eel and hold its front with a dry towel and squeeze the abdomen with the other hand from front to back to lay eggs smoothly. if blocked, cut 0.5 cm into the cloacal cavity with small scissors and squeeze it for 3 times in a row. After squeezing the eggs into the container, kill the male eel and take out the testis (observe sperm motility with a magnifying glass of more than 400 times), wipe off the blood with a dry towel, cut it up with scissors, gently grind it into a mortar, stir fully with feathers in the eggs (female / male ratio is 2 / 3 / 3 / 1), then add 200 ml of Ren's solution (50 ml per tail eel), place for 5 minutes, then wash off the testicular fragments and blood stains with clean water. It can be hatched artificially.

Artificial incubation

Because of the serious harm of water mildew between 23 and 27 ℃, the indoor dripping incubation method is generally adopted. In the incubator, water enters from the bottom and overflows from the top. The water depth is about 10 cm, the water temperature is 25-30 ℃, and the daily temperature difference is less than 5 ℃. The bottom of the container was covered with sand to prevent water mildew. When the fertilized eggs first entered the incubator, the number of water droplets was 10 drops / min, lasted for 1 day, 1520 drops / min on the 2nd and 3rd day, and 30 drops / min on the 4th day until the seedlings were hatched. Unfertilized eggs should be removed in time, otherwise it is easy to worsen the water quality, the more in the later stage, the more to increase the frequency of water change, generally about 5-7 days out of the film.

Seedling cultivation

The cultivation pond adopts a small cement pool, with an area of 5 square meters, a depth of 30 square meters, a soil addition of 5 centimeters at the bottom, a cow dung or pig manure of 0.5 kilograms and a water depth of 10 centimeters. It is best to introduce water worms into the pond, and water hyacinth must be planted on the pool surface. The eel entered the culture pond 4-7 days after coming out of the film. 600 eels per square meter were put into the culture pond, and the eels were fed 2 times a day. When the eel seedlings grow to 4cm, the density is 20000tails / square meter. In about a month, the eel seedlings grow to about 8 centimeters, and about 100 eels per square meter are stocked. With a body length of 15 cm and a weight of 3 to 10 grams, it can be transferred to an eel pond for culture.