Net cage culture technique of leech

In the countryside, we see that leeches grow in mud fields, which are wild leeches. Now they are cultivated artificially, and many of them are raised in ponds, cages and rice fields. Let's follow the editor to see how it is raised in the cage.

Net cage culture technique of leech

1. Cage setting

The fish pond area is 1000 square meters, east-west long, north-south wide, the bottom is flat without silt, easy to enter and discharge, the perennial water level is not less than 1.0m. In the pond, there are several rows juxtaposed and misplaced, each row is 2 meters apart, the cage in the row is not spaced, more than 1.5 meters away from the ridge of the pond, there are 50 rows of 10 in each fish pond, the depth of the cage is 0.2 meters, the exposed water is 0.8 meters, and the bottom of the cage is about 0.2 meters from the bottom.

The cage is a rectangle made of polyethylene jointless mesh cloth, and the upper opening surface extends 0.15 meters inward to prevent escape eaves, which is fixed by wooden piles and tightened with soft wire rope at the upper end.

2. Preparation before entering the box

The young leech cage was sprinkled and disinfected with 10% polyvitamin copper code 250ml in the whole pool, and 1 kg of biological fish fertilizer was applied after 24 hours.

3. Young leeches enter the box

After all the preparatory work has been done, the 20 jin leech cocoons that have been hatched in the foam box soil for 20 days and are about to be broken after cleaning up. In 20 young leech cages, about 400 egg cocoons were released in each cage, then 2 foam box covers were put in each cage, 2-3 Misgurnus anguillicaudatus and 4-5 grass carp were put in on the 10th.

4. Cover the bird prevention net

On the second day after the leech egg cocoon was put into the box, the polyethylene mesh with a mesh of 5cm, which was cut into 20.5m × 2.05m, was covered on four rows and five longitudinally arranged cages to prevent bird damage, and the anti-bird net was stitched and fixed on the cage according to the standard of 1 meter and 1 knot with a net needle.

5. Feeding and management

① bait: feed the vertebra snail in the young leech cage. The snail was soaked in multivitamin solution for 8 hours and then fed every three days. The feeding amount should be adjusted and replenished according to the number of floating snails left in the box.

After dividing the boxes, the fresh field snails harvested from the lake area were put into use, and different types of steel sieves of 0.8 × 0.8cm, 1.2 × 1.2cm and 1.6 × 1.6cm were selected at different growth stages of leeches.

② water quality regulation: apply biological fertilizer, the amount of water depth per mu is 0.7kg and 5kg respectively. After dilution, the fertilizer should be sprinkled according to the dose of 2tap 3 in the box and 1ap3 outside the box; in addition, the 20mlEM bacteria, Water King and 10 grams of Udiomyces should be put in each cage every 15 days.

With the growth of leeches, the water level gradually deepened to the depth of 0.5 meters into the cage; in July, August, September and October, the 5-inch submersible pump was started at noon every day for two hours to circulate the whole water through the culvert between the two fish ponds. Throughout the leech culture period, the transparency of the water body has always been maintained between 20 and 30 centimeters.

③ leech disease prevention: in the whole breeding process, adhere to the "no disease first prevention, disease early treatment." The principle of.

④ leeches were divided into boxes. When the number of leeches reached 1000 per 0.5kg of leeches, the young leeches of 20 cages were put into the cages of 100 young leeches according to the standard of one kilo and a half of leeches per cage. After 2-3 tail slices of Loach and 4-5 tail of summer flower and grass fish were put into the cage the next day, they were all covered with bird prevention net.

⑤ daily management: patrol the pool once a day, check the cage for breakage and leech feeding, observe the leech life and growth trends, and make good production records.

Distribution situation

It is produced in lakes, ponds and paddy fields in most parts of China. Money leeches are mainly produced in Weishan, Dongping, Nanyang Lake and other lakes in Shandong Province, with the largest output of Weishan Lake, which is not only supplied to the province, but also sold in Northeast China, Hebei and Shanxi. Some of the products produced in the suburbs of Suzhou and Wuxian in Jiangsu Province are also exported. In addition, Zhejiang, Hunan, Hubei, Shaanxi, Liaoning, Anhui, Hebei, Sichuan, Jilin, Heilongjiang and other places are also produced and sold by themselves.

environment

Leeches are omnivorous animals, taking the blood or body fluids of animals as the main way of life, often using plankton, insects and molluscs in the water as the main bait, and artificial conditions with all kinds of animal viscera, cooked egg yolk, formula feed and plant residues. Freshwater snail shellfish, miscellaneous fish, earthworms and so on.

Living in rice fields, ditches, shallow water pollution pits, etc., addicted to human and animal blood, the movement is very agile, can swim in waves, can also make ruler-like migration. It is active every warm spring, and its spawning period is from June to October. In winter, it tends to lie dormant in the inshore wet mud, do not eat and move, and have strong viability.

Growth and reproduction

The reproductive habits of leeches are hermaphroditic, allogeneic, in vivo fertilization, and have both male and female reproductive organs, which are carried out in the opposite direction during mating, and there is a phenomenon of "sexual reversal" in life history and the exchange of gender roles. A leech can be both a father and a mother, playing different roles in different periods of life. About a month after mating, the female genitals secrete thin mucus, which is wrapped in egg bands, shaped like "silkworm cocoons", and is excreted out of the body and hatched in wet mud at a suitable temperature. Young leeches are hatched from the cocoons in about 16-25 days and start an independent life.

Matters needing attention in the Culture of Leech

1. Pay attention to escape prevention: build an anti-escape wall on the periphery of the pond, with a height of more than 80cm and 90cm. The inside of the wall is covered with cement and sand.

2. A large number of aquatic plants are released: mainly water hyacinth and duckweed. Leeches are afraid of direct sunlight, so planting a large number of aquatic plants can not only be used as feed for field snails, but also cover the light, and leeches can also lay eggs on them.

3. Adequate feed: about 50 kg of field snails should be put into every 667 square meters of water. In addition, the blood clot of livestock and poultry should be put once a week for leeches, but the clot should not contain salt. In order not to affect the water quality, the blood clot can not be directly put into the water. The blood clot can be placed on the wood block to float on the surface of the water. After smelling the smell, the leech can climb up to pick food, and the blood clot should not be placed for more than two days.

4. After introduction, the leeches should not be put directly into the pond: because in the process of transportation, the leeches themselves will produce a layer of mucous membrane as a protective film. You should choose a cool and damp place around the pond and put the leeches inside and let them climb into the pond on their own to reduce death.

Pay attention to observation: leeches breed in the soil under the mulch, not in water. During the breeding period, if the water overflows the soil bed for about 7 days, the leech eggs will die due to lack of oxygen, so you should pay attention to it to ensure the success of breeding.

6. Timely capture: the capture period is usually in October. The leeches salvaged are separated by large, medium and small. The large ones are screened out and put back in the pool and left as leeches; the small ones are kept in a pool so that they can be salvaged and sold when they reach more than 15 grams in the second year, and the medium ones should be processed into dried products and sold immediately.

The leech has strong viability, fast reproduction and high medicinal value, and now the breeding technology is becoming more and more familiar, so it is very suitable for everyone to choose a kind of farmed aquatic animals.