CN111066702A

CN111066702A - Method for indoor high-density breeding of Sipunculus nudus

Info

Publication number: CN111066702A
Application number: CN201911401335.3A
Authority: CN
Inventors: 李俊伟; 陈素文; 胡瑞萍; 朱长波; 齐占会; 区又君; 张文文
Original assignee: South China Sea Fisheries Research Institute Chinese Academy Fishery Sciences
Current assignee: South China Sea Fisheries Research Institute Chinese Academy Fishery Sciences
Priority date: 2019-12-30
Filing date: 2019-12-30
Publication date: 2020-04-28
Anticipated expiration: 2039-12-30
Also published as: CN111066702B

Abstract

The invention belongs to the technical field of marine organism culture, and relates to a method for indoor high-density culture of Sipunculus nudus. The method comprises the following steps: 1) preparing a culture device: the culture pond comprises a culture pond, a growing sand bed, an air supply assembly and a water inlet and drainage assembly, wherein the bottom of the growing sand bed is sequentially paved with a bolting silk cloth, a medium coarse sand layer and a fine sand layer upwards; 2) preparing a breeding feed: the breeding feed comprises sedimentary microalgae, floating mud powder, large algae powder and large algae liquid; 3) fattening the sand bed substrate; 4) sipunculus nudus breeding: the sipunculus nudus is put on a growing sand bed of a breeding device, and breeding feed is put on the surface of the growing sand bed for feeding; 5) and (5) managing aquaculture water. Sufficient supply of the dissolved oxygen content in the interstitial water is realized by increasing the oxygenation efficiency in the substrate, and then high-density live fresh microalgae bait is added to solve the problems of insufficient dissolved oxygen in enough ecological benthic living microalgae and the interstitial water, so that the high-density cultivation of the sipunculus nudus is realized.

Description

Method for indoor high-density breeding of Sipunculus nudus

Technical Field

The invention belongs to the technical field of marine organism culture, and particularly relates to a method for indoor high-density culture of Sipunculus nudus.

Background

Sipunculus nudus, commonly known as sandworms, is distributed in the south China sea, the east China sea, coastal sandy mudflats and shallow sea. The sandworm has higher nutritive value and delicious taste, has extremely high dietary therapy and medicinal value, has the reputation of the marine cordyceps sinensis in coastal folks, and has obvious effects of improving immunity, resisting fatigue and the like by active substances extracted from the body of the marine cordyceps sinensis. The sandworms are convenient to eat, like sea cucumbers, can be eaten fresh or can be stored after being processed into dry products. Therefore, the Sipunculus nudus is a special marine product with edible and medicinal values. The sandworm industry in China has a complete industrial chain and has systems for seed production, cultivation, processing and the like. With the increase of demand of people for sandworm products and the annual reduction of natural resources, the yield of sandworms cultured only on mudflats is not enough to support the consumer market, and particularly the demand of sandworm deep-processing products cannot be met.

At present, the main technical bottleneck and reasons for limiting the Sipunculus nudus high-density culture (pond and factory) are that ecological baits suitable for Sipunculus nudus to eat and sufficient dissolved oxygen supply are not solved all the time. Firstly, along with the increase of breeding time, the organic matter that is migrated to the sand bed by sandworm forms the material that the reducibility is stronger easily, and the accumulation of material such as sulphide and ammonia nitrogen can restrain biological growth, can cause the sandworm to die when serious. Secondly, in a natural environment, sipunculus nudus can only eat microalgae and other granular substances in the surface layer of the substrate, natural benthic diatoms (microalgae) and other settled organic granules can only meet the ingestion and growth of a small amount of sipunculus nudus, the organic matter content of the artificial compound feed is too high, local hypoxia and deterioration are easily caused after the sipunculus nudus is transferred to the substrate, the artificial compound feed is not beneficial to cultivation and growth, the ingredient of the artificial compound feed is complex, the sipunculus nudus, which is an animal lacking special digestive glands, is not eaten and utilized, the influence on the deterioration of the substrate caused by the artificial compound feed is more obvious, and the accumulation of nutrient substances in the sipunculus nudus is mainly from mudflat microalgae and organic matter; thirdly, traditional adopting digs the ability limited, and novel high-pressure squirt washes the mud flat substrate, and harvest efficiency can improve 5~10 times, but has certain negative effects to mud flat environment and biodiversity.

A box type Sipunculus nudus breeding method (CN109006697A) adopts sea cucumber compound feed or Sipunculus nudus compound feed for feeding, however, the higher organic matter in the compound feed can cause the substrate to become black and worsen, the dissolved oxygen content in the substrate is reduced, and harmful substances such as sulfide and the like can be generated, thereby influencing the normal growth; meanwhile, the bait for feeding is lack of natural microalgae, which is not beneficial to the utilization and accumulation of natural fatty acid, amino acid and trace elements by sipunculus nudus. The effective use area of the culture box of the patent is still only limited to a single layer in the box. One square meter of 100 strips are cultured in a single culture box, and because the side surface of the culture box limits the flow of water, oxygen deficiency in the box is easily caused by high-density and high-content organic matters.

A method (CN109122428A) suitable for delirium benthonic breeding of sandworms is to hatch and breed the whole process in a mode of combining pond breeding and mudflat breeding, and because the open-air pond is greatly influenced by climate, the quality and the quantity of products are not easy to ensure. The feed is fed by adopting a plurality of organic matters, and the Sipunculus nudus ingests and excretes to cause accumulation of the organic matters, so that the substrate is blackened, sulfides and other substances are generated, and high-density culture cannot be realized.

A method (CN102106315B) for culturing Sipunculus nudus in pond mainly relates to the technology of culturing Sipunculus nudus in pond, which feeds prawn with compound feed, the feed has higher protein content and is easier to produce ammonia nitrogen and sulfide.

An industrial feed for Sipunculus nudus is prepared from plant algae powder, fish powder, shell powder and clay through mixing, and features high organic content and easy deterioration of substrate.

A method (CN105557577A) for mixed culture of Sipunculus nudus and Babylonia areolata adopts soybean meal, peanut meal, gulfweed powder, shrimp shell powder, squid powder and the like as feeding baits, and easily causes deterioration influence on substrate.

A method (CN107466926A) for culturing sandworms in a pond adopts natural settled granular substances in the pond, belongs to extensive culture, and does not involve bait preparation and feeding.

Disclosure of Invention

Aiming at the problems in the prior art, the invention aims to provide an indoor high-density Sipunculus nudus breeding method to realize high-density Sipunculus nudus breeding.

The technical content of the invention is as follows:

a method for indoor high-density cultivation of Sipunculus nudus comprises the following steps:

1) preparing a culture device: the device comprises a culture pond, a growing sand bed, an air supply assembly and a water inlet and drainage assembly, wherein the bottom of the growing sand bed is sequentially paved with a bolting silk cloth, a medium coarse sand layer and a fine sand layer upwards, and a micropore oxygenation pipe is paved between the sand layers;

the growing sand bed is positioned in the culture pond, and the culture pond is connected with the air supply assembly and the water inlet and outlet assembly;

2) preparing a breeding feed: the aquaculture feed comprises sedimentary microalgae, floating mud powder, large algae powder and large algae liquid, wherein the sedimentary microalgae is prepared from raw materials including sodium alginate, microalgae and fine sand, and the microalgae comprises dunaliella salina, Platymonas mellea, chlorella vulgaris, Alternaria and porphyridium; microalgae without cell walls or with thin cell walls are selected as much as possible, so that the grinding and absorption of the microalgae bait in the digestive tract are facilitated; (the sodium alginate is used for embedding floating microalgae into benthic microalgae and has light transmission performance; the fine sand is used for increasing gravity to become nuclei of sedimentary microalgae and be more easily ingested by sipunculus nudus; and the microalgae is used for providing natural living microalgae bait and can utilize nutrient substances in water to achieve the purpose of purifying water quality);

3) and (3) fattening the sand bed substrate: before the sand worm seedlings are put in, the breeding feed is put into a sand bed to fatten the sand bed bottom material, which is beneficial to the enrichment of microalgae and organic matters on the surface layer of the sand bed and provides a good adaptive environment for the sand worms;

4) sipunculus nudus breeding: after the substrate fattening is finished, the sipunculus nudus is put on a growing sand bed of the breeding device, and breeding feed is put on the surface of the growing sand bed for feeding; the first month after the Sipunculus nudus drills into the artificial sand bed is a key period for Sipunculus nudus cultivation. The adaptability of the sipunculus nudus to a new environment and the molding degree of a cave structure are important factors influencing the survival rate of the sipunculus nudus, so that the palatability and the ingestion efficiency of the sipunculus nudus are increased by feeding natural baits and feeding floating mud;

5) and (3) managing culture water: putting oysters into the culture pond, wherein 6-10 oysters are put in each cubic meter, the specification is 20-50 g/oyster, so that the granular substances in the water body can be filtered, and main ammonia nitrogen in excrement of the oysters can be used as a nitrogen-containing substance source of the sedimentary microalgae bait; the conditions for controlling the culture water are as follows: salinity is 25-32, water temperature is 20-35, dissolved oxygen is more than 5mg/l, pH is 8.5-8.5, and illumination is 2500-3500 lx.

Culturing density: the breeding density of the seedlings is 100-150 strips/m²Preferably, the number of the individual is controlled to be 100/m when the individual is larger²Within 5-6 months after cultivation, the cultivation density can be reduced by harvesting large specifications.

Further, in the step 1), the laying thickness of the medium coarse sand layer is 20-25 cm, and the laying thickness of the fine sand layer is 5-10 cm;

the sand grain size range of the middle coarse sand layer is 0.25-1.5 mm, and the sand grain size of the fine sand layer is less than or equal to 0.25 mm;

the micropore oxygenation pipe is placed in an S shape, the distance between adjacent pipelines is 30-50 cm, a long-handle filter head is generally used for backwashing a sand layer in the backwashing process of the existing sand filter, the sand layer can be moved due to the operation, cave damage of the sipunculus nudus can be caused, growth of the sipunculus nudus can be influenced, and the micropore oxygenation can be adopted to oxidize organic matters of the substrate by gas, so that accumulation of sulfide, ammonia nitrogen and nitrous acid is reduced, and damage to the star trail cave can not be caused.

Further, in step 3), the preparation method of the sedimentary microalgae is as follows: a) preparing a sodium alginate solution with the concentration of 2.3-3%, adding sodium chloride with the same mass, heating, cooking and pasting together to obtain a viscous particle-free liquid, and cooling for later use; b) mixing the liquid obtained in the step a) with microalgae and fine sand uniformly; c) preparing a calcium chloride solution with the concentration of 1-2%, adding the uniformly mixed solution obtained in the step b), stirring and crushing to obtain a particle product, namely the sedimentary microalgae, wherein the particle size of the particles is less than or equal to 1.5 mm;

the concentration of the microalgae is more than or equal to 200 ten thousand per mL, and the concentration of the microalgae in the sedimentary microalgae is more than or equal to 100 ten thousand per mL;

the floating mud powder is obtained by collecting floating mud from the surface layer of a substrate in an intertidal zone, drying and crushing, and the particle size range is less than or equal to 0.1 mm; the floating mud is rich in benthic microalgae, trace elements and other near-shore organic matters, is suitable for the nutritional requirements in Sipunculus nudus, and meets the culture quality in a natural environment; the quality of the floating mud is good, the floating mud on the surface layer is scraped from the intertidal zone, the surface layer of the beach surface needs to be scraped, and the black and smelly sea mud is prevented from being scraped. For long-term use and preservation, the floating mud can be preserved after being exposed, sterilized and dried, and a certain amount of floating mud is taken and sieved when in use.

The large algae powder comprises ulva and gracilaria, and is dried in the sun and then crushed for use;

the macroalgae liquid comprises grinding liquid of fresh sargassum thunbergii and fresh sargassum;

the feeding mode of the aquaculture feed in the step 4) is that firstly floating mud powder, large algae powder and large algae liquid are fed and deposited at the bottom of a sand layer, and then sedimentary microalgae are fed, wherein the feeding amount of the sedimentary microalgae is 20-30 ppm each time;

the feeding amount of the large algae liquid is 10-20 ppm each time, the large algae liquid is fed once every 3 days, the feeding amount of the large algae powder is 2-5 ppm each time, and 15-25 ppm of floating mud is added.

According to the oral structure of Sipunculus nudus, the particle size of less than 1.5mm is suitable for the caliber size and excretion of Sipunculus nudus, and the particle size can influence the food intake and excretion; sodium alginate does not damage the digestive tract; microalgae in the digestive tract and bacteria in the intestinal tract act together to generate organic matters which can be absorbed and utilized by sipunculus nudus; the microalgae in the sodium alginate can grow and propagate without increasing the reducibility of the substrate, and nitrogen and phosphorus nutrient substances generated by other baits on the surface of the substrate can be utilized, so that the method belongs to ecological environment-friendly baits.

And (3) inflating: except stopping air when feeding the feed, continuously aerating in water in a micro-scale manner at other times; and (3) inflating the microporous oxygenation pipe at the bottom in the morning for 30-60 minutes every day, and stopping until the water color on the surface of the inflated sand layer is not obvious gray.

Water feeding and draining: before the micro-pores are aerated, 5-10 cm of bottom water is discharged every day and then is supplemented to the original water level.

Illumination: the sunlight and the lamplight are combined, the illumination intensity above the water surface of the culture pond is kept at 2500-3000 lx in the daytime, and the lamplight irradiates for 6 hours at night.

Disease control: the sargassum seedlings harvested by digging or flushing with high pressure water gun are easy to be injured, and are sterilized with iodine solution (effective iodine content is 0.1 g/m)³) Transferring the mixture into a culture barrel after 20 minutes to avoid injury, infection and death; the purpose of disinfection is to destroy the cell membrane structure and protein molecules of pathogens by using the super-strong oxidizability of iodine atoms to lose the activity of the pathogens, and the sandworm seedlings disinfected by iodine solution can prevent the pathogens from entering the culture pond. After the Sipunculus nudus is injured or infected, the surface of the sand layer can be exposed at the lips or the front part of the body of the Sipunculus nudus, and the Sipunculus nudus needs to be transferred in time to prevent the decomposition of organic matters and the breeding of harmful germs after death.

The invention has the following beneficial effects:

the method for breeding Sipunculus nudus in high density indoors is characterized in that the dissolved oxygen content in the substrate is increased, the circulating flow of substrate interstitial water is accelerated, the sufficient supply of the dissolved oxygen content in the interstitial water is realized, and then high-density live fresh microalgae bait is added, so that the problems of sufficient ecological benthic living microalgae and insufficient dissolved oxygen in the interstitial water are solved, the high-density breeding of the Sipunculus nudus is realized, and the used sedimentary microalgae is used as breeding feed, so that the method is favorable for improving the breeding water quality and the substrate and realizes the high-quality breeding of the Sipunculus nudus.

Drawings

FIG. 1 is a graph showing the feeding effect of Sipunculus nudus on sedimentary microalgae.

Detailed Description

The present invention is described in further detail in the following description of specific embodiments and the accompanying drawings, it is to be understood that these embodiments are merely illustrative of the present invention and are not intended to limit the scope of the invention, which is defined by the appended claims, and modifications thereof by those skilled in the art after reading this disclosure that are equivalent to the above described embodiments.

All the raw materials and reagents of the invention are conventional market raw materials and reagents unless otherwise specified.

Examples

a culture pond: building a rectangular cement culture pond, wherein the length is 4-5 m, the width is 3-4 m, the pond depth is 1.0-1.5 m, and a growing sand bed is arranged in the culture pond;

growing a sand bed: the sand bed comprises a frame structure made of polyethylene, a chassis and side plates, wherein the bottom plate and the side plates can be made of wood, the specification of the sand bed chassis is 1m multiplied by 1m or 1m multiplied by 3m or other specifications, the sand bed chassis is supported by a cross beam, the side plates are arranged above the bottom, the height of the side plates is 40cm, and the side plates are provided with a plurality of holes (the diameter is 5cm) so as to promote the flow of a water body;

the sand bed chassis and the side plates are paved with bolting silk cloth with the aperture of 80-100 meshes to prevent coarse sand from losing, a medium coarse sand layer with the thickness of 20-25 cm and a fine sand layer with the thickness of 5-10 cm are sequentially paved upwards from the bolting silk cloth of the chassis, the particle size range of the medium coarse sand is 0.25-1.5 mm, sharp substances such as shells and the like are screened out, and the alimentary canal is prevented from being scratched;

the grain size of the fine sand is less than or equal to 0.25mm, the fine sand is used as a bait carrier, and the total thickness of the sand layer is more than or equal to 30 cm;

micropore oxygenation pipes are laid between the sand layers, the diameter of each water pipe is 1cm, the water pipes are placed in an S shape, the distance between adjacent pipelines is 30-50 cm, the content of dissolved oxygen in a sipunculus nudus growing area is improved through micropore oxygenation, and harmful substances such as ammonia nitrogen, sulfide and anaerobic bacteria are reduced to promote ingestion, improve vitality and reduce diseases. Meanwhile, due to the downward flow of the water body, the oxygen-enriched water also improves the bottom environment of the sand bed, and reduces the breeding of disease bacteria;

the air supply assembly: a Roots blower is arranged to be used as air source supply, and air stones are placed on the surface of the sand layer;

water inlet and drainage assembly: one end of the bottom of the culture pond is provided with a water inlet pipe, the pipe orifice is parallel to the bottom of the culture pond, the ingestion and excretion of the sipunculus nudus and the water flow can transfer fine sand to the bottom of a sand layer, some fine sand or organic particles can leak to the bottom of the culture pond through the screened silk cloth, when the water pipe switch at the bottom is started, the fine sand at the bottom and the like can flow through a water outlet of the culture pond, and at the moment, the fine sand can be collected and sterilized and can be recycled;

the upper part of the culture pond is also provided with a water inlet pipe, the distance between the water inlet pipe at the upper part and the bottom of the culture pond is 1.0-1.5 m, and the water inlet pipes are arranged above and at the bottom of the culture pond to prevent water flow from directly impacting a sand bed;

one end of the culture pond is provided with a water outlet, and the water outlet pipeline is communicated with the outside; pumping an upper water body of a reservoir or other water sources into a water inlet pipe through a water pump, and enabling the water to flow into the culture pond, wherein a water inlet is filtered by adopting 500-mesh bolting-silk cloth;

and (3) disinfection treatment: preparing 5ppm strong chlorine solution, and thoroughly disinfecting a cement pool, a micropore oxygenation tube, an indoor workshop, used materials and the like;

and (3) illumination control: the cultivation house ceiling needs a light-transmitting material, a black top film is covered above the cultivation house ceiling to adjust light transmission, light rays are irradiated into the cultivation pond in sunny days, growth of benthic microalgae is facilitated, nutritive salt in a water body is utilized, Sipunculus nudus has a strong ingestion rhythm, ingestion activity in daytime is strong, water temperature and sand layer temperature are improved through irradiation of enhanced light, the day and night rhythm of the Sipunculus nudus is strengthened, and ingestion efficiency in daytime is improved.

2) Preparing a breeding feed: the aquaculture feed comprises sedimentary microalgae, floating mud powder and macroalgae, wherein the sedimentary microalgae is prepared from raw materials including sodium alginate, microalgae and fine sand, and the microalgae comprises dunaliella salina, Platymonas mellea, chlorella vulgaris, Alternaria hainanensis and porphyridium;

preparing a microalgae culture pond, and culturing dunaliella salina, Platymonas campestris, Chlorella vulgaris, Alternaria haitanensis and Porphyridium at a culture concentration of more than 200 ten thousand per mL;

the preparation method of the sedimentary microalgae comprises the following steps:

a) preparing a sodium alginate solution with the concentration of 2.3-3%, adding sodium chloride, heating, cooking and pasting together to obtain brown yellow liquid, and cooling for later use;

b) uniformly mixing the liquid obtained in the step a) with microalgae with the same volume;

c) preparing a calcium chloride solution with the concentration of 1-2%, dripping the solution uniformly mixed in the step b), moving the position to be changed, dripping to prevent the sodium alginate from being adhered together, stirring, and crushing to obtain a particle product, namely the sedimentary microalgae, wherein the particle size of the particles is less than or equal to 1.5 mm;

the floating mud is collected from the surface layer of the substrate in the intertidal zone by 1cm, dried and crushed, and the particle size range is less than or equal to 0.1 mm;

the feeding mode of the aquaculture feed in the step 2) is that firstly floating mud powder, large algae powder and large algae liquid are fed and deposited at the bottom of a sand layer, and then sedimentary microalgae are fed, wherein the feeding amount of the sedimentary microalgae is 20-30 ppm each time;

feeding 10-20 ppm of large algae liquid every time, feeding once every 3 days, feeding 2-5 ppm of large algae powder every time, and adding 15-25 ppm of floating mud;

the breeding feed is uniformly fed onto the surface of a growing sand bed, the breeding feed feeding mode is that firstly floating mud powder, large algae powder and large algae liquid are fed and deposited at the bottom of a sand layer, then sedimentary microalgae are fed, and the feeding amount of the sedimentary microalgae is 20-30 ppm each time; (with the growth of Sipunculus nudus, the adding amount of floating mud is increased, large algae powder and floating mud powder need to be uniformly mixed with fresh sargassum thunbergii grinding liquid, water is cut off, and the mixture is uniformly splashed after air is cut off, after 2-3 hours, bait is settled to the surface of a sand layer, air is refilled and water is added, the Sipunculus nudus ingests to form an obvious patch-shaped bait-free area on the surface of the sand layer, and the feeding amount is flexibly mastered according to the growth and ingestion conditions of the Sipunculus nudus.

4) sipunculus nudus breeding: after the substrate fattening is finished, the sipunculus nudus is put on a growing sand bed of the breeding device, and breeding feed is put on the surface of the growing sand bed for feeding; the first month after the Sipunculus nudus drills into the artificial sand bed is a key period for Sipunculus nudus cultivation. The adaptability of Sipunculus nudus to new environment and the molding degree of the cave structure are important factors influencing the survival rate of Sipunculus nudus. Therefore, the palatability and the ingestion efficiency are increased by feeding natural baits and feeding floating mud.

The ingestion effect of Sipunculus nudus on sedimentary microalgae is shown in figure 1, the left side is an initial graph, wherein plaques are sedimentary microalgae feed, the right side is a graph after feed eating is finished, and holes on the surface layer of sediments are formed in the ingestion or disturbance process of the Sipunculus nudus in a sand layer, which indicates that the Sipunculus nudus can well ingest sedimentary microalgae.

Test examples

Breeding objects: sipunculus nudus;

the culture method comprises the following steps: the cultivation system and the cultivation feed of the embodiment are adopted;

culturing time: seedling releasing in 5-12 months and 5 months every year;

seedling setting density: 60 to 80 strips/m²；

And (3) seedling releasing specification: 2-3 g/strip;

feeding mode: feeding the deposited microalgae for 1 time every 3 days, wherein the feeding amount is 10g/m²(ii) a Feeding the mixture of floating mud powder, large-scale seaweed powder and large-scale seaweed liquid for 1 time in three days, wherein the feeding amount is 5g/m²(ii) a Feeding the next time according to the accumulation degree of the substances on the surface layer of the sand layer;

comparative example 1

The sipunculus nudus is placed in a cement pond for cultivation, sand mud on a beach is put in the cement pond, the feeding is carried out according to the feeding mode of the embodiment, and other conditions are unchanged;

comparative example 2

Placing Sipunculus nudus in the culture system prepared in the embodiment, feeding prawn feed granules or macroalgae crushed granules, and keeping other conditions unchanged;

comparative example 3

Selecting a beach to breed the Sipunculus nudus.

The Sipunculus nudus of examples and comparative examples 1 to 3 were cultured in 1000 pieces, and the results of the culture were accepted six months after the culture, and are shown in the following table.

TABLE 1 comparative data on cultivation methods

As can be seen from the above table, the cultivation method of this embodiment adopted in the experimental examples can greatly increase the survival rate of sipunculus nudus compared with other cultivation methods, and obtain high-density and high-quality sipunculus nudus.

The indexes of the experimental examples and the culture water quality of comparative example 2 are monitored, and the results are shown in table 2:

TABLE 2 Water quality index monitoring and substrate index monitoring

Ammonia nitrogen and nitrite nitrogen are contents in interstitial water of the bottom sediment, the growth of the sipunculus is influenced when the contents are respectively higher than 0.1 and 0.2 by taking culture production experience as a standard, the oxidation-reduction potential is higher than-60, and the higher the oxidation-reduction potential is, the more sufficient the oxygen is, the more beneficial the growth of the benthonic animals is.

From the above table, the cultivation method of the embodiment has little influence on the cultivation water quality, the natural living microalgae can utilize the nutritive salt in the water body, and compared with the feed used in the proportion 2, the cultivation method of the invention is favorable for improving the substrate environment of the water body and avoiding water quality pollution.

Claims

1. A method for breeding Sipunculus nudus in high density indoors is characterized by comprising the following steps:

2) preparing a breeding feed: the aquaculture feed comprises sedimentary microalgae, floating mud powder, large algae powder and large algae liquid, wherein the sedimentary microalgae is prepared from raw materials including sodium alginate, microalgae and fine sand, and the microalgae comprises dunaliella salina, Platymonas mellea, chlorella vulgaris, Alternaria and porphyridium;

3) and (3) fattening the sand bed substrate: putting the breeding feed into a sand bed to fatten the sand bed substrate;

4) sipunculus nudus breeding: after the substrate fattening is finished, the sipunculus nudus is put on a growing sand bed of the breeding device, and breeding feed is put on the surface of the growing sand bed for feeding;

5) and (3) managing culture water: oysters are put into the culture pond to filter and eat the particulate matters in the water body.

2. The method for breeding Sipunculus nudus according to claim 1, wherein the laying thickness of the medium-coarse sand layer in the step 1) is 20-25 cm, and the laying thickness of the fine sand layer is 5-10 cm.

3. The method for breeding Sipunculus nudus according to claim 1, wherein the sand grain size of the medium-coarse sand layer in step 1) is in the range of 0.25-1.5 mm, and the sand grain size of the fine sand layer is less than or equal to 0.25 mm.

4. The method for breeding Sipunculus nudus according to claim 1, wherein the microporous oxygenation pipe in step 1) is placed in an S shape, and the distance between adjacent pipelines is 30-50 cm.

5. The method for cultivating Sipunculus nudus according to claim 1, wherein the sedimentary microalgae in step 2) is prepared by the following steps: a) preparing a sodium alginate solution with the concentration of 2.3-3%, adding sodium chloride with the same mass, heating, cooking and pasting together to obtain a viscous particle-free liquid, and cooling for later use; b) mixing the liquid obtained in the step a) with microalgae and fine sand uniformly; c) preparing a calcium chloride solution with the concentration of 1-2%, adding the uniformly mixed solution obtained in the step b), stirring and crushing to obtain a particle product, namely the sedimentary microalgae, wherein the particle size of the particles is less than or equal to 1.5 mm.

6. The method for cultivating Sipunculus nudus according to claim 5, wherein the concentration of the microalgae is greater than or equal to 200 ten thousand per mL, and the concentration of the microalgae in the sedimentary microalgae is greater than or equal to 100 ten thousand per mL.

7. The method for breeding Sipunculus nudus according to claim 1, wherein the floating mud powder in step 2) is obtained by collecting floating mud from the surface layer of the substrate in the intertidal zone, drying in the sun and crushing, and the particle size range is less than or equal to 0.1 mm.

8. The method for cultivating Sipunculus nudus of claim 1, wherein the macroalgae powder of step 2) comprises Ulva lactuca and Gracilaria verrucosa, and is dried in the sun and then pulverized.

9. The method for cultivating Sipunculus nudus according to claim 1, wherein the macroalgae liquid of step 2) comprises ground solution of fresh Sargassum thunbergii and fresh Sargassum micracum.

10. The method for breeding Sipunculus nudus of claim 1, wherein the breeding feed of step 3) is prepared by adding floating mud powder, macroalgae powder and macroalgae solution, depositing on the bottom of sand layer, and adding sedimentary microalgae.