Culture technique of leeches (leeches)

Leeches (leeches) are traditional Chinese special medicinal aquatic animals. After their dried products are processed, traditional Chinese medicine is used in traditional Chinese medicine, which is mainly natural fishing in history. Due to the abuse of pesticides, chemical fertilizers and the environmental pollution caused by the "three wastes" of industry and agriculture in recent years, wild natural resources have decreased sharply. With the in-depth development of the medicinal value of leeches, their market demand is huge. Let's take a look at leech breeding technology.

Site construction

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, a dense net is used to live 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. Artificial cultivation of money leeches is better, money vermiculite body shape is large, the yield is high, that is, commonly known as "cow leeches" in rural areas, herding cattle often climb on 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, so it is appropriate to release them in early spring. In early spring, it can be grown, processed and sold in October.

Reproductive management

1. Build a breeding pond: the area of the pool should be about 30 square meters, and a square of 5 × 5 meters or 6 × 6 meters should be built. The pool is surrounded by a platform of 1 × 1.5 meters against the pool wall, with a water surface in the middle and a water depth of 50 centimeters. The platform is 2 centimeters above the water surface and 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.

2, seed leech selection: used for seed reproduction and seed horse leeches, the age should be more than 2 years, the weight is about 30 grams, 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 management: in the middle and lower reaches of the Yangtze River, the time for leech spawning cocoons begins at the beginning of 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.

Feeding technique

1. Feed feeding: leeches mainly feed on the blood of snails, earthworms and other invertebrates and mammals. The natural feed is mainly snails, supplemented by earthworms and insect larvae. Artificial feed is the blood of all kinds of animals. After feeding, the blood clotting residue should be removed in time so as not to pollute the water quality.

2. Regulation of water quality: leeches do not have strict requirements on the environment and water quality, and the water temperature should be kept at 1530 ℃. Too high or too low will affect growth, but the density of artificial culture is high, and the water quality should be kept clean, so it is necessary to ensure a certain amount of dissolved oxygen. The water temperature is high from July to August, so we should pay attention to changing the water properly.

3. Overwintering management: when the temperature drops below 10 ℃, the leeches stop feeding and hibernate in the soil or under the leaves. Drain through the winter by covering the surface of the pool with straw or wooden poles to prevent freezing and keep the soil moist. During the winter with ice, the pool water should be properly deepened to prevent complete freezing.

Disease prevention and cure

1. Dry blight

[etiology] caused by high temperature, diseased leeches lose appetite, lack of activity or inactivity, emaciation and weakness, showing dry body, dehydration and atrophy, and blackening all over the body.

[prevention and treatment] ① washed the diseased leeches in 1% salt water twice a day for 10 minutes each time. ② was fed with yeast tablets or oxytetracycline to increase calcium food and improve disease resistance. ③ increases the water flow and lowers the water temperature.

2. White spot disease

[etiology] it is caused by more protozoa than small melon worms. There are white spot bubbles and small white plaques on the body surface of diseased leeches, which are inflexible, unable to balance and anorexia when swimming.

[prevention and treatment] ① washed diseased leeches with 2 mg / L mercuric nitrate for 30 minutes each time, twice a day. ② disinfects pool water with bleach regularly, usually once or twice a month.

3. Gastroenteritis

[etiology] due to eating spoiled food or indigestible food, sick leeches lose appetite, lazy, red and swollen anus.

[prevention and treatment] 0.4% sulfamidazole was mixed with bait for ① and fed. ② was fed with 0.2% oxytetracycline.