Leech culture technique

Abstract: leeches, commonly known as leeches, grow and breed in inland freshwater waters. They are traditional Chinese medicinal aquatic animals. After their dried products are processed, they are used in traditional Chinese medicine to treat stroke, hypertension, clearing blood stasis, amenorrhea, falling injury and other effects. In recent years, leech preparations have been found to have special effects in the prevention and treatment of cardio-cerebrovascular diseases and anti-cancer. In history, it is mainly natural fishing, due to the abuse of pesticides and chemical fertilizers in recent years.

Leech, commonly known as leech, grows and breeds in inland fresh water. It is a traditional Chinese special medicinal aquatic animal. Its dried products are used in traditional Chinese medicine after being processed and used in traditional Chinese medicine. It has the effects of treating stroke, hypertension, clearing blood stasis, amenorrhea, falling injury and so on. In recent years, leech preparations have been found to have special effects in the prevention and treatment of cardio-cerebrovascular diseases and anti-cancer. In history, it is mainly natural fishing, due to the abuse of pesticides and chemical fertilizers in recent years, and the environmental pollution caused by the "three wastes" of industry and agriculture, the wild natural resources have decreased sharply. With the in-depth development of the medicinal value of leeches, its market demand potential is huge.

Construction of breeding farm

Choose the shelter from the wind to the sun, convenient drainage and irrigation to build a pool. The ridge around the pond is 1.8 meters high and the water depth is 1 meter. The area should be determined according to the amount of feeding. Generally, 6 ~ 100000 young leeches can be released per mu of water surface. The opposite corner of the pool is provided with a water inlet and a drain. In order to facilitate the habitat and spawning of leeches, irregular stones or branches can be placed at the bottom of the pond. There should be five or eight soil platforms 20 centimeters above the horizontal level in the pool, each platform about 1 square meter. The pool ridge should also be set up to prevent escape ditches, which are made of bricks, with a width of 12 cm and a height of 8 cm. When it rains, they live with a dense net or sprinkle some lime in the ditch to prevent escape.

Put into planting and stocking

The source of leech seedlings can be caught, purchased or propagated. At the beginning of breeding, it is generally based on natural capture, and you can also buy it from the relevant units. There are three kinds of leeches that are traditionally used as medicine in China: money leeches are better for artificial breeding. Money vermiculite is large in shape and high in yield. Money leeches are commonly known as "cow leeches" in rural areas. Herding cattle often climb on the cattle to suck blood, and attention should be paid to identification when catching and breeding. The leeches are hermaphroditic, and each leech can lay eggs and reproduce. From late March to April (Yangtze River Basin, the same below), the egg cocoons are laid in the soil. Generally, there are 1-4 egg-laying cocoons, and the number of young hirudin in each cocoon is 13-35, most of which are about 20. Each leech can reproduce 60-80 at a time. A large number of young leeches appeared in June and grew rapidly. Within one month after hatching, the average growth was more than 20 mm, and it was indistinguishable from adults in September and October. It is appropriate to release it in early spring. In early spring, it can be grown, processed and sold in October.

Artificial propagation technology of leech

1. The construction of the breeding pond: the area of the pool should be about 30 square meters, and a square of 5 meters × 5 meters or 6 meters × 6 meters should be built. The pool is surrounded by a platform of 1 by 1.5 meters against the pool wall, with a water surface in the middle, a water depth of 50 centimeters, and a platform 2 centimeters above the water surface. The platform is kept moist. The soil for the platform should be loose sandy soil with high humus content, which is convenient for leeches to drill holes, and yellow clay should not be used. Overflow vents should be set up on the platform to prevent Rain Water from flooding the platform and causing breeding failure. It is generally divided into two types: small culture ponds and large culture ponds:

The construction of ① small-scale aquaculture pond generally builds a pond ditch with a width of 3 meters and a depth of 1 meters, with unlimited length. A number of small ponds can also be built, with a ridge width of 40 cm, and a water inlet and outlet in each pool. In the middle of the pond must be a spawning platform with a width of 50ml and 100cm. The platform and the water surface are on the same level, with a layer of humus soil 20 cm thick on the platform. As a place for leeches to lay eggs and reproduce. The water level is 50ml / 60cm.

Construction of ② large aquaculture ponds the construction of large aquaculture ponds is generally built with different specifications according to the actual geographical environment. If the water source is not convenient, you can also spread a layer of plastic film on the bottom of the pool. An appropriate amount of river mud should be put into the bottom of the pond to increase the content of organic matter in the water. Planting some aquatic plants in the water can purify the water quality and increase the oxygen content in the water. It is best to bury a circle of nylon gauze on the bank of the pool (0.5 m high) to prevent frogs, snakes and other natural enemies from entering the pond. In order to prevent the summer water temperature from being too high and the light too strong, weeping willows and other trees can be planted on the bank of the pool to shade the sun.

2, the choice of leeches: used for breeding and breeding horse leeches, the age should be more than 2 years, the weight is about 30 grams, physically strong, lively and active, and quickly shrink into a ball with the touch of the hand. Such leeches have a large number of eggs and high hatching rate, and the amount of leeches is calculated according to the land area of the platform in the pool, generally about 1.5 kg per square meter. After planting leeches into the pond, the water quality should be kept thick and there should be enough plankton and snail lions for them to feed on.

3. Reproduction: in the middle and lower reaches of the Yangtze River, the time for leech spawning cocoons begins in early May and lasts from the middle of June to the middle of June (depending on individual differences), and the peak of reproduction is in the middle of May. Keep quiet during the spawning cocoon period and avoid walking and shaking on the shore, otherwise, the leeches that are spawning cocoons will be frightened and run away, resulting in empty cocoons.

4. Hatching management: after laying eggs, the leeches can be collected, raised or processed in another pond, and the breeding pool is also used as the hatching pond. The egg cocoons allow them to hatch naturally in the cave channel, and the young leeches are hatched about 11-15 days after the egg cocoons are produced. The newly hatched young leeches look like adults and are cork yellow, with seven purple-gray fine longitudinal lines on each side of the back. With the growth of young leeches, the color between the longitudinal stripes gradually changed, forming five longitudinal stripes composed of two kinds of markings and changing into adult color stripes. In the incubation stage, you should try to avoid walking on the platform so as not to break the cocoon. The platform should be moist and can be covered with a layer of water plants. If you encounter rainy weather to dredge the overflow, the water surface should not pass through the platform, keeping a gap of about 3 centimeters. After the breeding species of leeches are fished out, young mussels and snail lions can be put to feed on young leeches. After hatching, young leeches live mainly on yolk within two or three days, and can be eaten three days later. The newly hatched young leeches mainly feed on the blood and juice of the clam and snail lion. in a clam, they will drill into a number of 100 young leeches. As the larvae grow up, they will devour the whole soft part of the clam and snail lions. The young leeches grow rapidly, with an average growth of more than 15 mm after half a month, and can be transferred into a large pool to be raised as leeches.