Method for culturing leeches and application thereof

Abstract

The application discloses a leech breeding method and application thereof, and belongs to the technical field of leech breeding.The leech breeding method comprises the following steps: hatching of egg cocoons, breeding in a rearing box, breeding in a breeding pond, and management of breeding in the breeding pond; the temperature and humidity are controlled to provide a stable development environment for leech embryos, and the hatching rate of the egg cocoons is improved; the egg cocoons are hatched in the rearing box, the damage of the leeches is reduced, the natural ecological breeding environment is simulated, the proportion of aquatic plants is reasonably configured, the traditional Chinese medicine extract is matched, problems such as tail rot, skin rot, stress, and excessive harmful bacteria in the water body are effectively solved, and the survival rate of the leeches is improved; the traditional Chinese medicine extract matched with black algae can accelerate the decomposition of organic matter, and the EM bacterial agent can reduce the accumulation of ammonia nitrogen.The leech breeding method provided by the application follows the natural survival characteristics of the leeches, reduces the high mortality rate caused by stress, diseases and water pollution, and greatly improves the hatching rate and survival rate of the leeches.

Description

Technical Field

[0001] This invention relates to the field of leech farming technology, and more particularly to a leech farming method and its application. Background Technology

[0002] Leeches are a traditional and valuable Chinese medicinal herb. They contain hirudin, which has potent anticoagulant properties and can clear blockages in the cardiovascular system, making it widely used in the clinical treatment of cardiovascular and thrombotic diseases. Market demand is increasing year by year. However, due to pollution from agricultural fertilizers, pesticides, and industrial wastewater, wild leech resources are continuously depleting, and market supply heavily relies on large-scale artificial breeding. The hatching rate and seedling survival rate directly determine the profitability of breeding and the level of industrial scale development.

[0003] Currently, artificial breeding of leeches mostly adopts a combination of pond mud spawning platforms and open-air centralized incubation. Common problems within the industry are prominent: the overall egg and cocoon hatching rate is less than 50%, the survival rate of juvenile leeches is less than 40%, and the survival rate for small and medium-sized individual farmers is even as low as 15%. The severe shortage of seedling production capacity seriously restricts the standardization and intensive development of the industry. The existing breeding technology deficiencies are concentrated in several aspects.

[0004] Firstly, inadequate environmental management leads to high stress-induced mortality rates for embryos and leeches. Open-air hatching relies on natural climate, making it impossible to maintain stable substrate humidity necessary for leech embryo development; excessive temperature fluctuations can directly cause embryos to stop developing. Transferring leeches to larger ponds makes it difficult for them to adapt to the environment of excessive ammonia nitrogen, nitrite, and insufficient dissolved oxygen, resulting in mass stress-induced deaths. Furthermore, unscientific aquatic plant combinations, such as insufficient shading scorching of seedlings with a single type of plant or complete coverage leading to oxygen depletion, can cause leech suffocation, bacterial rot, and other diseases.

[0005] Secondly, the imbalance of the aquatic micro-ecology makes the prevention and control of seedling diseases difficult. Traditional aquaculture relies on water changes and quicklime disinfection to control water quality, but it has not established a long-term beneficial microbial system. Uneaten feed and excrement accumulate in the water, leading to the proliferation of harmful bacteria. Farmers overuse disinfectants and antibiotics, which not only damage seedlings and reduce survival rates, but also cause pesticide residues in medicinal materials to exceed standards, violating the GAP (Good Agricultural Practices) requirements for green aquaculture of Chinese medicinal materials. A single aquatic plant cannot continuously purify the water, leaving seedlings under long-term environmental stress, hindering their growth and feeding.

[0006] Third, the breeding system suffers from discontinuity and significant human costs. The egg-laying, hatching, and seedling cultivation stages are independent of each other, and the repeated handling and turning of the cocoons can easily cause mechanical damage. At the same time, there is a lack of suitable starter feed programs, resulting in insufficient feeding and low immunity in the seedlings, leading to a continuous decline in survival rate later on.

[0007] While currently available patents and aquaculture literature mention a few localized optimization solutions such as improving hatching soil and using single aquatic plants for water purification, they cannot fundamentally improve both the hatching rate of egg cocoons and the long-term survival rate of juvenile leeches. The industry urgently needs an integrated leech breeding technology solution that takes into account ecological water quality regulation, microecological antibacterial properties, and segmented environmental acclimatization. Summary of the Invention

[0008] To address the aforementioned problems, this invention provides a leech farming method and its application. The leech farming method provided by this invention follows the natural survival characteristics of leeches, reduces the high mortality rate caused by stress, disease, and water pollution, and significantly improves the hatching rate and survival rate of leeches.

[0009] To achieve the above objectives, the present invention provides a leech farming method, comprising the following steps: 1) Select healthy leeches for cultivation, put the leeches into the breeding bed for reproduction, and harvest the egg cocoons after 20-25 days; 2) Incubation box hatching: The hatching box is filled with breeding soil, and the harvested egg cocoons are placed on it. The top layer is covered with 1.5-2cm of moisturizing soil. The temperature is maintained at 22℃-25℃ and the humidity at 70%-80% for 20-24 days. A spray pipe is installed above the hatching box to spray moisture in real time. After 20-24 days of hatching, observe whether there are seedlings breaking out of the cocoons and start collecting the egg cocoons. 3) Intensive culture box farming: Set up an indoor intensive culture box: fill the intensive culture box with fertilized water; place water hyacinth and black algae in the water, with the water hyacinth covering 30% of the water surface area and the black algae covering 30% of the bottom area, and the black algae placed at intervals. Place the egg cocoons collected in step 2) in water. The larvae will emerge from the cocoons and crawl into the water. Raise the juvenile leeches for 13-16 days. During the first 1-4 days of rearing, feed them a mixture of egg yolk and crushed small snails. From the 5th day onwards, start feeding them small snails, with a snail-to-leek ratio of 1:3-5. Maintain an indoor temperature of 22℃-25℃ and humidity of 70%-80% for the first 1-2 days. From the 3rd day onwards, ensure the indoor temperature and humidity maintain the same trend as the outdoor temperature and humidity. Transfer them to outdoor rearing ponds via net cages on the 13th-16th day. One day before transfer, sprinkle a traditional Chinese medicine extract into the rearing cages, with a ratio of 8-10 ml of extract to 1 ml of water. 3 ; 4) Aquaculture ponds: A waterproof tarpaulin and escape-proof net are erected above the aquaculture pond. Sprinkler pipes are installed around the top of the pond, and a drainage pipe is installed 3cm above the bottom of the pond. Multi-layered aquaculture boards are laid at the bottom. Fertilized water is injected, and floating, emergent, and submerged plants are placed in the pond. The floating and emergent plants occupy 30% to 35% of the pond area, and the submerged plants occupy 35% to 38%. The floating plants are water hyacinths, and the emergent plants are reeds, which are planted in a dotted pattern. The submerged plants are hydrangeas, which are planted in concentrated groups along the pond walls. Sprinkle the herbal extract into the water every 12-15 days; the stocking density of juvenile leeches in the breeding pond is 300-500 leeches / m². 2 The animals are separated into different ponds after 58 to 62 days of rearing. 5) Separate culture ponds: The stocking density in the separate culture ponds is 150~250 fish / m². 2 The management of the separate rearing ponds is the same as the routine management of the rearing ponds.

[0010] Preferably, the aquaculture soil comprises the following components in parts by weight: 4-6 parts garden soil, 2-3 parts fine river sand, and 1-2 parts mushroom residue.

[0011] Preferably, the herbal extract is prepared by decocting the following components in parts by weight: Astragalus membranaceus 28-32 parts, Scutellaria baicalensis 15-20 parts, Isatis indigotica 20-25 parts, Polygonum cuspidatum 10-15 parts, Pogostemon cablin 8-12 parts, and Rheum palmatum 3-7 parts.

[0012] Preferably, the preparation method of the traditional Chinese medicine extract includes the following steps: 1) Accurately weigh the Chinese herbal ingredients, add water with a total weight of 10 times the weight of the Chinese herbal ingredients, and boil them. Filter out the first decoction and the dregs. 2) Add water five times the total weight of the Chinese medicinal ingredients to the dregs from the first decoction and boil again, then filter out the decoction from the second decoction. 3) Mix the decoctions obtained from the first and second decoctions and dilute them 3 to 4 times to obtain a Chinese herbal extract.

[0013] Preferably, the amount of snails fed during the breeding pond is 200-250 kg / mu.

[0014] Preferably, the water change frequency of the breeding pond is: once every 15 days, and the water volume changed each time is 15~20cm.

[0015] Preferably, EM bacteria are applied to the aquaculture pond every 20-25 days during the aquaculture period to improve water quality.

[0016] Preferably, the pH value of the water in the incubator, breeding pond, and separate breeding pond is 6.8~7.5.

[0017] Preferably, the ratio of the herbal extract to the water in the aquaculture pond is 40-50 mL: 1 mL. 3 .

[0018] This invention also provides the application of the breeding method described above in improving the survival rate of leeches.

[0019] Compared with the prior art, the present invention has the following technical effects: 1) This invention maintains a stable developmental environment for leech embryos by precisely controlling temperature and humidity parameters, thereby significantly improving the overall hatching rate of egg cocoons.

[0020] 2) This invention establishes an indoor simulated natural ecological intensive breeding system. By directly hatching egg cocoons in the intensive breeding box, the damage to leeches caused by the transfer of young leeches is reduced. Through domestication and cultivation, young leeches are gradually adapted to the outdoor pond water environment, effectively reducing the stress damage caused by environmental changes and greatly improving the survival rate of young leeches throughout the breeding process.

[0021] 3) This invention optimizes the ratio and planting density of various aquatic plants: Hydrilla verticillata can efficiently degrade ammonia nitrogen in water and continuously increase dissolved oxygen at the bottom; water hyacinth and reeds work together to provide shade and cooling, and together with Hydrilla verticillata, they construct a multi-layered habitat and shelter space. At the same time, the aquatic vegetation can attach and cultivate natural benthic food to meet the feeding and hiding needs of leeches.

[0022] 4) The application of the compound Chinese herbal extract in this invention can improve leech skin rot and tail rot symptoms, alleviate stress responses caused by environmental stress, and inhibit the proliferation of harmful microorganisms in the water. Combined with *Hydrilla verticillata*, it can accelerate the decomposition of organic pollutants in the water, preventing excessive accumulation of organic matter. Rhubarb in the formula can form a synergistic effect with Bacillus in the EM agent, enhancing the degradation efficiency of residual feed and excrement, and reducing the risk of ammonia nitrogen accumulation in the water from the source.

[0023] The leech farming method provided by this invention follows the natural survival characteristics of leeches, reduces the high mortality rate caused by stress, disease, and water pollution, and significantly improves the hatching rate and survival rate of leeches. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 Hatching rates of leeches using different farming methods; Figure 2 Survival rates of leeches under different farming methods. Detailed Implementation

[0026] This invention provides a method for leech farming, comprising the following steps: 1) Select healthy leeches for cultivation, put the leeches into the breeding bed for reproduction, and harvest the egg cocoons after 20-25 days; 2) Incubation box hatching: The hatching box is filled with breeding soil, and the harvested egg cocoons are placed on it. The top layer is covered with 1.5-2cm of moisturizing soil. The temperature is maintained at 22℃-25℃ and the humidity at 70%-80% for 20-24 days. A spray pipe is installed above the hatching box to spray moisture in real time. After 20-24 days of hatching, observe whether there are seedlings breaking out of the cocoons and start collecting the egg cocoons. 3) Intensive culture box farming: Set up an indoor intensive culture box: fill the intensive culture box with fertilized water; place water hyacinth and black algae in the water, with the water hyacinth covering 30% of the water surface area and the black algae covering 30% of the bottom area, and the black algae placed at intervals. Place the egg cocoons collected in step 2) in water. The larvae will emerge from the cocoons and crawl into the water. Raise the juvenile leeches for 13-16 days. During the first 1-4 days of rearing, feed them a mixture of egg yolk and crushed small snails. From the 5th day onwards, start feeding them small snails, with a snail-to-leek ratio of 1:3-5. Maintain an indoor temperature of 22℃-25℃ and humidity of 70%-80% for the first 1-2 days. From the 3rd day onwards, ensure the indoor temperature and humidity maintain the same trend as the outdoor temperature and humidity. Transfer them to outdoor rearing ponds via net cages on the 13th-16th day. One day before transfer, sprinkle a traditional Chinese medicine extract into the rearing cages, with a ratio of 8-10 ml of extract to 1 ml of water. 3 ; 4) Aquaculture ponds: A waterproof tarpaulin and escape-proof net are erected above the aquaculture pond. Sprinkler pipes are installed around the top of the pond, and a drainage pipe is installed 3cm above the bottom of the pond. Multi-layered aquaculture boards are laid at the bottom. Fertilized water is injected, and floating, emergent, and submerged plants are placed in the pond. The floating and emergent plants occupy 30% to 35% of the pond area, and the submerged plants occupy 35% to 38%. The floating plants are water hyacinths, and the emergent plants are reeds, which are planted in a dotted pattern. The submerged plants are hydrangeas, which are planted in concentrated groups along the pond walls. Sprinkle the herbal extract into the water every 12-15 days; the stocking density of juvenile leeches in the breeding pond is 300-500 leeches / m². 2 The animals are separated into different ponds after 58 to 62 days of rearing. 5) Separate culture ponds: The stocking density in the separate culture ponds is 150~250 fish / m². 2 The management of the separate rearing ponds is the same as the routine management of the rearing ponds.

[0027] In this invention, the culture soil in step 2) preferably comprises the following components in parts by weight: 4-6 parts garden soil, 2-3 parts fine river sand, and 1-2 parts mushroom substrate, more preferably 5 parts garden soil, 3 parts fine river sand, and 2 parts mushroom substrate. The garden soil and fine river sand need to be sieved to remove impurities before use; the culture soil is treated with ultraviolet light before use to thoroughly sterilize and kill insects; the thickness of the culture soil laid in the incubation box is preferably 30-40 cm, more preferably 35 cm; the moisture content of the culture soil is preferably 32%-37%, more preferably 35%; the moisture content of the moisturizing soil is preferably 80%-90%; at this soil moisture content, a moist incubation bed can be provided for the egg cocoons, ensuring the moisture required for egg cocoon hatching. This step precisely controls the suitable temperature and humidity conditions required for leech egg cocoon development, stabilizes the embryonic development environment, and significantly improves the overall hatching rate of the egg cocoons.

[0028] In this invention, the preferred height of the fertilized water injected in step 3) is 30-40 cm. Adding fertilized water enriches the rotifer content in the pond, providing sufficient initial food for the larvae, supplementing exogenous nutrition, and improving the survival rate of the seedlings. This invention reduces leech damage caused by transferring leeches by directly hatching egg cocoons in the intensive rearing box, thus improving the leech survival rate. After the egg cocoons hatch, they are domesticated and cultivated in the intensive rearing box by simulating a natural ecological breeding system, which helps the newly hatched leeches gradually adapt to the outdoor pond water environment, effectively reducing stress damage caused by sudden environmental changes and significantly improving the survival rate of leech larvae throughout the entire rearing process.

[0029] In this invention, the herbal extract is preferably prepared by decocting the following components in parts by weight: Astragalus membranaceus 28-32 parts, Scutellaria baicalensis 15-20 parts, Isatis indigotica 20-25 parts, Polygonum cuspidatum 10-15 parts, Pogostemon cablin 8-12 parts, and Rheum palmatum 3-7 parts; more preferably, Astragalus membranaceus 30 parts, Scutellaria baicalensis 20 parts, Isatis indigotica 20 parts, Polygonum cuspidatum 15 parts, Pogostemon cablin 10 parts, and Rheum palmatum 5 parts. The preparation method of the herbal extract includes the following steps: 1) accurately weigh the herbal components, add water with a total weight of 10 times the weight of the herbal components, decoct, and filter out the first decoction and dregs; 2) add water with a total weight of 5 times the weight of the herbal components to the dregs from the first decoction, decoct, and filter out the second decoction; 3) mix the decoctions obtained from the first and second decoctions, and dilute them 3-4 times to obtain the herbal extract. Sprinkling a traditional Chinese medicine extract evenly in the rearing box the day before transfer can effectively reduce the stress response of young leeches and reduce the mortality rate caused by stress.

[0030] In this invention, the spray pipe and outlet pipe in the aquaculture pond described in step 4) are preferably made of polytetrafluoroethylene (PTFE) to prevent the growth of harmful bacteria, microorganisms, and algae inside the pipes. A drainage pipe is installed 3cm above the bottom of the aquaculture pond to prevent silt, uneaten feed, snails, etc., from clogging the outlet pipe. The height of the injected fertilized water is preferably 50-80cm, with a preferred water level of 80cm in summer and 50-60cm in spring and autumn. The snail feeding rate during the aquaculture period is 200-250kg / mu, more preferably 230kg / mu. The water change frequency in the aquaculture pond is preferably once every 7-15 days, with a preferred water change volume of 15-20cm each time. In summer, when temperatures are high, the water is changed every 7-10 days with a preferred water change volume of 20cm. In spring and autumn, the water is changed every 12-15 days with a preferred water change volume of 15cm. The water change standard is preferably maintained by ensuring the pond water remains a light green color and is transparent.

[0031] In this invention, during the aquaculture pond, EM (Effective Microorganisms) agents are applied every 20-25 days to improve water quality; and a traditional Chinese medicine extract is sprinkled into the water every 12-15 days. The preferred ratio of the traditional Chinese medicine extract to the water in the aquaculture pond is 40-50 mL: 1 mL. 3 The Bacillus spp. in the EM agent can form a synergistic effect with the traditional Chinese medicine ingredient rhubarb, enhancing the degradation efficiency of residual feed and excrement, and reducing the risk of ammonia nitrogen accumulation in water bodies from the source.

[0032] In this invention, the breeding boxes, breeding ponds, and separate breeding ponds must all undergo water purification and disinfection before use; the pH value of the water in the hatching boxes, breeding ponds, and separate breeding ponds must be maintained at 6.8~7.5, and uneaten feed must be removed regularly during the breeding period.

[0033] This invention also provides the application of the breeding method described above in improving the survival rate of leeches.

[0034] To further illustrate the present invention, a leech farming method and its application provided by the present invention will be described in detail below with reference to the accompanying drawings and embodiments, but these should not be construed as limiting the scope of protection of the present invention.

[0035] Example 1 Leech farming methods.

[0036] 1) Select healthy leeches for cultivation, put the leeches into the breeding bed for reproduction, and harvest the egg cocoons after 20-25 days; 2) Incubation box hatching: Preparation of soil for cultivation: Take garden soil and fine river sand, pass them through a 20-mesh sieve to remove impurities, mix the sieved garden soil, fine river sand and mushroom residue, spray water after mixing to maintain the soil moisture content at 20%; Preparation of fertilizer water: Take fermented and decomposed cow manure, amino acid fertilizer paste, and a small amount of phosphate fertilizer. After clearing the pond and testing the water, add 50 kg of fermented and decomposed cow manure and 1 kg of fertilizer paste per mu. The water depth is 30 cm. After 3 days, the water color will turn yellow-green and the transparency will be about 25 cm. The incubator is filled with culture soil, and the harvested cocoons are placed on it. The top layer is covered with 1.5-2cm of moisturizing soil to maintain a temperature of 24℃ and a humidity of 80% for 22 days. A spray pipe is installed above the incubator to spray moisture in real time. After 22 days of incubation, observe whether any seedlings have emerged from the cocoons and start collecting the cocoons. 3) Intensive culture box farming: Preparation of Chinese herbal extract: Take 30 parts of Astragalus membranaceus, 20 parts of Scutellaria baicalensis, 20 parts of Isatis indigotica, 15 parts of Polygonum cuspidatum, 10 parts of Pogostemon cablin, and 5 parts of Rheum palmatum, totaling 1 kg, add 10 kg of water and decoct. Filter out the first decoction and the dregs. 2) Add 5 kg of water to the dregs from the first decoction and decoct. Filter out the second decoction. 3) Mix the decoctions obtained from the first and second decoctions and dilute to 50 kg to obtain the Chinese herbal extract. Set up an indoor intensive culture box: fill the intensive culture box with 35cm of fertilized water; place water hyacinth and black algae in the water, with the water hyacinth covering 30% of the water surface area and the black algae covering 30% of the bottom area, and the black algae placed at intervals. Place the egg cocoons collected in step 2) in water. The larvae will emerge from the cocoons and crawl into the water, and the juvenile leeches will be cultured for 15 days. During the first 1-4 days of juvenile leech culture, feed them a mixture of egg yolk and crushed small snails. From the 5th day onwards, start feeding them small snails, with a snail-to-juvenile leech ratio of 1:4. Maintain an indoor temperature of 24℃ and humidity of 80% for the first 1-2 days. From the 3rd day onwards, ensure the indoor temperature and humidity maintain the same trend as the outdoor temperature and humidity. On the 15th day, transfer them to a culture cage in an outdoor culture pond. The day before transfer, sprinkle a traditional Chinese medicine extract into the intensive culture cage, with the extract mixed with water in the intensive culture cage at a ratio of 9 ml: 1 ml. 3 ; 4) Aquaculture ponds: A waterproof tarpaulin and escape-proof net are erected above the aquaculture pond. Sprinkler pipes are installed around the top of the pond, and a drainage pipe is installed 3cm above the bottom of the pond. Multi-layered aquaculture boards are laid at the bottom. Fertilized water is injected, and floating, emergent, and submerged plants are placed in the pond. The floating and emergent plants occupy 35% of the pond area, and the submerged plants occupy 35%. The floating plants are water hyacinths, and the emergent plants are reeds, which are planted in a dotted pattern. The submerged plants are hydrangeas, which are planted in concentrated groups along the pond walls. The water level should be 80cm in summer and 50-60cm in spring and autumn. The snails should be fed 230kg / mu (approximately 15.5 kg / acre) during the rearing period. Water exchange frequency: every 7-10 days in the hot summer (20cm water change); every 12-15 days in spring and autumn (15cm water change). The ideal water exchange standard is to maintain a consistently light green color and clear water. During the aquaculture pond period, EM bacteria agent is applied every 20 days to improve water quality, and traditional Chinese medicine extract is sprinkled into the water every 14 days; the optimal ratio of traditional Chinese medicine extract to water in the aquaculture pond is 45 mL: 1 mL. 3 The stocking density of juvenile leeches in the breeding pond was 400 leeches / m². 2 They are separated into different ponds after 60 days of rearing; 5) Separate culture ponds: The stocking density in the separate culture ponds is 200 individuals / m². 2 The breeding and management of the separate breeding ponds are the same as the routine management of the breeding ponds. The pH value of the water in the hatchery, breeding pond and separate breeding pond is maintained at 6.8~7.5.

[0037] Example 2 Leech farming methods.

[0038] 1) Select healthy leeches for cultivation, put the leeches into the breeding bed for reproduction, and harvest the egg cocoons after 20-25 days; 2) Incubation box hatching: Preparation of soil for cultivation: Take garden soil and fine river sand, pass them through a 20-mesh sieve to remove impurities, mix the sieved garden soil, fine river sand and mushroom residue, spray water after mixing to maintain the soil moisture content at 20%; Preparation of fertilizer water: Take fermented and decomposed cow manure, amino acid fertilizer paste, and a small amount of phosphate fertilizer. After clearing the pond and testing the water, add 50 kg of fermented and decomposed cow manure and 1 kg of fertilizer paste per mu. The water depth is 30 cm. After 3 days, the water color will turn yellow-green and the transparency will be about 25 cm. The incubator is filled with breeding soil, and the harvested egg cocoons are placed in it. The top layer is covered with 1.5-2cm of moisturizing soil to maintain a temperature of 23℃ and a humidity of 75% for 22 days of incubation. A spray pipe is installed above the incubator to spray moisture in real time. After 22 days of incubation, observe whether any seedlings have emerged from the cocoons and start collecting the egg cocoons. 3) Intensive culture box farming: Preparation of Chinese herbal extract: Take 30 parts of Astragalus membranaceus, 20 parts of Scutellaria baicalensis, 20 parts of Isatis indigotica, 15 parts of Polygonum cuspidatum, 10 parts of Pogostemon cablin, and 5 parts of Rheum palmatum, totaling 1 kg, add 10 kg of water and decoct. Filter out the first decoction and the dregs. 2) Add 5 kg of water to the dregs from the first decoction and decoct. Filter out the second decoction. 3) Mix the decoctions obtained from the first and second decoctions and dilute to 50 kg to obtain the Chinese herbal extract. Set up an indoor intensive culture box: fill the intensive culture box with 30cm of fertilized water; place water hyacinth and black algae in the water, with the water hyacinth covering 30% of the water surface area and the black algae covering 30% of the bottom area, and the black algae placed at intervals. Place the egg cocoons collected in step 2) in water. The larvae will emerge from the cocoons and crawl into the water. Raise the juvenile leeches for 13 days. During the first 1-4 days of rearing, feed them a mixture of egg yolk and crushed small snails. From the 5th day onwards, start feeding them small snails, with a snail-to-leek ratio of 1:4. Maintain an indoor temperature of 23℃ and humidity of 75% for the first 1-2 days. From the 3rd day onwards, ensure the indoor temperature and humidity follow the same trend as the outdoor environment. On the 13th day, transfer them to a rearing cage in an outdoor rearing pond. The day before transfer, sprinkle a traditional Chinese medicine extract into the rearing cage. The ratio of the extract to water in the rearing cage is 10ml:1ml. 3 ; 4) Aquaculture ponds: A waterproof tarpaulin and escape-proof net are erected above the aquaculture pond. Sprinkler pipes are installed around the top of the pond, and a drainage pipe is installed 3cm above the bottom of the pond. Multi-layered aquaculture boards are laid at the bottom. Fertilized water is injected, and floating, emergent, and submerged plants are placed in the pond. The floating and emergent plants occupy 30% of the pond area, and the submerged plants occupy 38%. The floating plants are water hyacinths, and the emergent plants are reeds, which are planted in a dotted pattern. The submerged plants are hydrangeas, which are planted in concentrated groups along the pond walls. The water level should be 80cm in summer and 50-60cm in spring and autumn. The snails should be fed 230kg / mu (approximately 15.5 kg / acre) during the rearing period. Water exchange frequency: every 7-10 days in the hot summer (20cm water change); every 12-15 days in spring and autumn (15cm water change). The ideal water exchange standard is to maintain a consistently light green color and clear water. During the aquaculture pond period, EM bacteria are applied every 25 days to improve water quality, and a traditional Chinese medicine extract is sprinkled into the water every 15 days. The optimal ratio of the traditional Chinese medicine extract to the water in the aquaculture pond is 40 mL: 1 mL. 3 The stocking density of juvenile leeches in the breeding pond is 500 leeches / m². 2 They are separated into different ponds after 60 days of rearing; 3) Separate culture ponds: The stocking density in the separate culture ponds is 250 individuals / m². 2 The breeding and management of the separate breeding ponds are the same as the routine management of the breeding ponds. The pH value of the water in the hatchery, breeding pond and separate breeding pond is maintained at 6.8~7.5.

[0039] Comparative Example 1 The leeches are placed in an incubation box and not fed during the incubation period. After one month, the incubation box is gently turned over, and the well-formed egg cocoons are selected. A 20 cm layer of sterilized culture soil is placed in the foam box beforehand. The egg cocoons are then neatly placed on the soil, and finally covered with easily crumbled soil, just enough to cover them completely. During the incubation period, the moisture content of the soil covering the egg cocoons is checked daily, and water is sprinkled as needed to ensure the soil moisture content reaches 85%. The box is then placed in a well-ventilated, shady environment for incubation. After 20 days of incubation, the egg cocoons are removed and placed in water for further incubation. When larvae emerge from the cocoons and surface, the young leeches are collected and transferred to a intensive rearing box.

[0040] Other implementation methods are the same as in Example 1.

[0041] Comparative Example 2 Seedling leeches are released into the breeding pond and not fed during the incubation period. After one month, the breeding pond is gently turned over, and well-formed egg cocoons are picked out. A 20 cm layer of sterilized breeding soil is placed in a foam box beforehand. The egg cocoons are then neatly placed on the soil, and finally covered with easily crumbled soil, just enough to cover the cocoons. During the foam box period, the moisture content of the soil covering the egg cocoons is checked daily, and water is sprinkled as needed to ensure the soil moisture content reaches 85%. The box is then placed in a well-ventilated, cool environment for incubation. After 20 days of incubation, the egg cocoons are removed and placed in water for further incubation. When larvae emerge from the cocoons and surface, the young leeches are collected and transferred to a intensive rearing box.

[0042] Traditional Chinese medicine extracts are not used during the breeding period in intensive rearing boxes, breeding ponds, and separate rearing ponds.

[0043] Other implementation methods are the same as in Example 1.

[0044] Comparative Example 3 Breeding leeches are released into a rearing pond and not fed during the incubation period. After one month, the pond is gently turned over, and well-formed egg cocoons are picked out. A 20 cm layer of sterilized rearing soil is placed in a foam box, and the egg cocoons are neatly placed on the soil. Then, easily crumbled soil is added on top of the cocoons, just enough to cover them completely. During the period in the foam box, the moisture content of the soil covering the cocoons is checked daily, and water is sprinkled as needed to ensure the soil moisture content reaches 85%. The box is then placed in a well-ventilated, cool environment for incubation. After 20 days of incubation, the egg cocoons are removed and placed in water for further incubation. When larvae emerge from the cocoons and surface, the young leeches are collected.

[0045] After collection, the samples are immediately transferred to breeding ponds for rearing. No Chinese herbal extracts are used during the rearing period in intensive rearing boxes, breeding ponds, and separate rearing ponds.

[0046] Other implementation methods are the same as in Example 1.

[0047] Example 3 Determination of leech hatching rate and survival rate.

[0048] During the process, record the number of egg cocoons placed. After transferring the juvenile leeches to the breeding pond, gently turn over the covering soil, pick out the egg cocoons, and record the number of egg cocoons that successfully hatched into juvenile leeches. The hatching rate is calculated using the following formula: Hatching rate (%) = (Number of egg cocoons that hatched leeches / Total number of egg cocoons) × 100%.

[0049] During the implementation process, record the number of leeches transferred to the breeding pond and the number of leeches transferred to the separate breeding pond, and calculate the survival rate of juvenile leeches. The survival rate is calculated using the following formula: Survival rate (%) = (Number of leeches transferred to the separate rearing pond / Number of leeches transferred to the main rearing pond) × 100%.

[0050] The results show (e.g.) Figure 1 , Figure 2 As shown in Table 1, the hatching rate and survival rate of leeches bred in a simulated natural ecological incubation system, domesticated and cultivated, and treated with traditional Chinese medicine extracts were higher than those of other comparative examples. Moreover, the hatching rate and survival rate in Example 1 were as high as 90%, indicating that the leech farming method of the present invention significantly improved the survival rate of leeches.

[0051] Table 1. Hatching rate and survival rate of leeches in aquaculture

[0052] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A method for leech farming, characterized in that, Includes the following steps: 1) Select healthy leeches for cultivation, put the leeches into the breeding bed for reproduction, and harvest the egg cocoons after 20-25 days; 2) Incubation box hatching: The hatching box is filled with breeding soil, and the harvested egg cocoons are placed on it. The top layer is covered with 1.5-2cm of moisturizing soil. The temperature is maintained at 22℃-25℃ and the humidity at 70%-80% for 20-24 days. A spray pipe is installed above the hatching box to spray moisture in real time. After 20-24 days of hatching, observe whether there are seedlings breaking out of the cocoons and start collecting the egg cocoons. 3) Intensive culture box farming: Set up an indoor intensive culture box: fill the intensive culture box with fertilized water; place water hyacinth and black algae in the water, with the water hyacinth covering 30% of the water surface area and the black algae covering 30% of the bottom area, and the black algae placed at intervals. Place the egg cocoons collected in step 2) in water. The larvae will emerge from the cocoons and crawl into the water. Raise the juvenile leeches for 13-16 days. During the first 1-4 days of rearing, feed them a mixture of egg yolk and crushed small snails. From the 5th day onwards, start feeding them small snails, with a snail-to-leek ratio of 1:3-5. Maintain an indoor temperature of 22℃-25℃ and humidity of 70%-80% for the first 1-2 days. From the 3rd day onwards, ensure the indoor temperature and humidity maintain the same trend as the outdoor temperature and humidity. Transfer them to outdoor rearing ponds in net cages on the 13th-16th day. One day before transfer, sprinkle a traditional Chinese medicine extract into the rearing cages, with a ratio of 8-10 ml of extract to 1 ml of water. 3 ; 4) Aquaculture ponds: A waterproof tarpaulin and escape-proof net are erected above the aquaculture pond. Sprinkler pipes are installed around the top of the pond, and a drainage pipe is installed 3cm above the bottom of the pond. Multi-layered aquaculture boards are laid at the bottom. Fertilized water is injected, and floating, emergent, and submerged plants are placed in the pond. The floating and emergent plants occupy 30% to 35% of the pond area, and the submerged plants occupy 35% to 38%. The floating plants are water hyacinths, and the emergent plants are reeds, which are planted in a dotted pattern. The submerged plants are hydrangeas, which are planted in concentrated groups along the pond walls. Sprinkle the herbal extract into the water every 12-15 days; the stocking density of juvenile leeches in the breeding pond is 300-500 leeches / m². 2 The animals are separated into different ponds after 58 to 62 days of rearing. 5) Separate culture ponds: The stocking density in the separate culture ponds is 150~250 fish / m². 2 The management of the separate rearing ponds is the same as the routine management of the rearing ponds.

2. The aquaculture method according to claim 1, characterized in that, The culture soil comprises the following components in parts by weight: 4-6 parts garden soil, 2-3 parts fine river sand, and 1-2 parts mushroom residue.

3. The aquaculture method according to claim 1, characterized in that, The herbal extract is prepared by boiling together the following components in parts by weight: Astragalus membranaceus 28-32 parts, Scutellaria baicalensis 15-20 parts, Isatis indigotica 20-25 parts, Polygonum cuspidatum 10-15 parts, Pogostemon cablin 8-12 parts, and Rheum palmatum 3-7 parts.

4. The aquaculture method according to claim 1, characterized in that, The preparation method of the traditional Chinese medicine extract includes the following steps: 1) Accurately weigh the Chinese herbal ingredients, add water with a total weight of 10 times the weight of the Chinese herbal ingredients, and boil them. Filter out the first decoction and the dregs. 2) Add water five times the total weight of the Chinese medicinal ingredients to the dregs from the first decoction and boil again, then filter out the decoction from the second decoction. 3) Mix the decoctions obtained from the first and second decoctions and dilute them 3 to 4 times to obtain a Chinese herbal extract.

5. The aquaculture method according to claim 1, characterized in that, The snails were fed 200-250 kg / mu during the breeding period in the breeding pond.

6. The aquaculture method according to claim 1, characterized in that, The water change frequency of the breeding pond is once every 7 to 15 days, and the water volume is 15 to 20 cm each time.

7. The aquaculture method according to claim 1, characterized in that, During the aquaculture period, EM bacteria agent is applied every 20-25 days to improve water quality in the aquaculture ponds.

8. The aquaculture method according to claim 1, characterized in that, The pH value of the water in the incubator, breeding pond, and separate breeding pond is 6.8~7.

5.

9. The aquaculture method according to claim 1, characterized in that, The ratio of the herbal extract to the water in the aquaculture pond is 40-50 mL: 1 mL. 3 .

10. The application of the aquaculture method as described in any one of claims 1 to 9 in improving the survival rate of leeches.

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