Interculture method for stichopus japonicus seedlings

Abstract

The invention discloses an intermediate cultivation method for stichopus japonicus fry, and belongs to the technical field of aquatic animal fry cultivation. According to the technical scheme, the method comprises the following steps: uniformly spraying 5000-6000 heads per jin of ginseng seedlings, 10000-20000 heads per jin of ginseng seedlings and 5000-60000 heads per jin of ginseng seedlings onto a three-dimensional layered flat net structure; small-sized sea cucumber seedlings are put on the three-dimensional layered flat net structure in the middle of the pond, large-sized sea cucumber seedlings are put on the three-dimensional layered flat net structures on the two sides of the pond, and the sea cucumber seedling putting density in the middle of the three-dimensional layered flat net structure is higher than the sea cucumber seedling putting density at the two ends of the three-dimensional layered flat net structure; the three-dimensional layered flat net structure comprises three layers of flat nets which are sequentially arranged from top to bottom, a plurality of flat nets are parallelly arranged in the pond at intervals, two cage net groups are parallelly arranged on each of two sides of each flat net, and the two cage net groups are arranged between the adjacent flat nets at intervals; and each cage net group consists of three cage nets which are arranged in the shape of a Chinese character'pin '. The method is applied to the aspect of cultivation of the stichopus japonicus seedlings, labor can be saved, and the yield and quality of the stichopus japonicus seedlings can be stably guaranteed.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of aquaculture of sea cucumber seedlings, and particularly relates to an intermediate cultivation method for sea cucumber seedlings. BACKGROUND

[0002] Sea cucumber is one of the highest single-species value species in marine aquaculture in China. In recent years, with the continuous expansion of sea cucumber aquaculture, the demand for high-quality sea cucumber seedlings has been increasing, and the price of commodity seedlings has been declining. Traditional sea cucumber intermediate cultivation is mostly carried out in factory workshops. In order to save production costs, open-air ponds are widely used for sea cucumber intermediate cultivation. At present, the intermediate cultivation of sea cucumber seedlings in ponds mostly adopts the method of net cage cultivation. The cost of sea cucumber intermediate cultivation in pond net cages is more than 60% lower than that of factory cultivation at the same period, which has certain application value, but still has certain limitations.

[0003] At present, the intermediate cultivation of sea cucumber in pond net cages has the disadvantages of poor environmental controllability, high seedling loss, difficult management, and unstable cost-effectiveness. The related technical research on the intermediate cultivation of sea cucumber in ponds mainly focuses on the improvement of net cage devices and the types of attached bases inside the net cages. For example, Chinese patent CN214709640U discloses a small net cage for cultivating juvenile sea cucumber seedlings in ponds, and Chinese patent CN204291991U discloses a net cage device for sea cucumber pond culture, which are improvements of net cage devices.

[0004] The existing method cannot well solve the problems of poor environmental controllability, high seedling loss, difficult management, high production cost, and unstable output. Specifically, the existing intermediate cultivation technology of sea cucumber seedlings has the following problems and disadvantages: (1) Labor-intensive, difficult to manage The cultivation capacity of a single net cage is limited, and a large number of net cages need to be laid out for large-scale cultivation, which not only occupies a large area of water, but also requires more manpower and material resources for management, making it difficult to realize intensive and automated cultivation.

[0005] The net cage needs to be regularly inspected for damage to the netting and cleaning of attached objects (such as barnacles), and the blockage of the netting can easily lead to poor water exchange between the inside and outside of the net cage. The feces and leftover feed inside the netting can cause environmental deterioration, and the netting and netting need to be replaced in time, which is labor-intensive, low in efficiency, and high in cost. It is not convenient to patrol and maintain.

[0006] (2) High seedling loss and high cost Seedling sorting loss: Juvenile sea cucumbers have large differences in growth rate and uneven size in the net cage, and need to be sorted regularly to avoid large seedlings suppressing small seedlings. However, it is easy to cause mechanical damage when catching juvenile sea cucumbers in the net cage, and the survival rate decreases by 10%-15% after sorting.

[0007] The loss caused by stress response of seedlings: due to the limitation of the space structure of the net cage, the vertical net cloth inside the net cage is easy to cause the juvenile sea cucumber to fall off, and it is difficult to reattach after falling off. When the environment at the bottom of the net cage is poor, the fallen seedlings are prone to cause adverse stress responses such as spitting and peeling, which affects the growth and even the survival of the seedlings.

[0008] The loss caused by subsequent cultivation of seedlings: after the intermediate cultivation of the sea cucumber seedlings, the process of harvesting, transportation, re-putting into a new environment for cultivation and growing up will cause the seedlings to produce a certain degree of stress response, slow growth and survival rate decline and other losses.

[0009] (3) Poor stress resistance and low quality of seedlings The internal cultivation environment of the net cage is poor in controllability, and the blockage of the net cloth easily causes low dissolved oxygen inside the net cage, poor bottom quality caused by the accumulation of residual feed and feces at the bottom, resulting in poor stress resistance of the cultivated seedlings. Under high-density cultivation, the seedlings will appear mutual extrusion, the activity space of the seedlings is limited, the self-feeding and activity ability is not high, the muscle is not developed, and the quality of the seedlings is not high.

[0010] The vertical net cloth inside the net cage is not easy to accumulate and settle plankton and organic particles, which easily causes insufficient feed of sea cucumber, and the feed is easy to flow away. The mixed feed, seaweed powder and the like fed to the sea cucumber are easy to be scattered by water flow, about 40-60% of the feed is not eaten by the juvenile sea cucumber, which not only causes waste, but also pollutes the water body. It is difficult to monitor the feces and feeding of the seedlings in real time inside the net cage, and it is easy to appear "insufficient feeding" or "excessive feeding", and it is impossible to adjust the type and feeding amount of the feed according to the growth stage. SUMMARY

[0011] In view of the deficiencies in the prior art, the present application provides a sea cucumber seedling intermediate cultivation method which can save labor and effort and stably ensure the yield and quality of sea cucumber seedlings.

[0012] To solve the technical problem, the technical scheme adopted by the present application is: The present application provides a sea cucumber seedling intermediate cultivation method, comprising: 5000-6000 heads / kg of sea cucumber seedlings, 10000-20000 heads / kg of sea cucumber seedlings, 50000-60000 heads / kg of sea cucumber seedlings are evenly sprinkled on the three-dimensional layered flat net structure; small-sized sea cucumber seedlings are placed on the three-dimensional layered flat net structure in the middle of the pond, large-sized sea cucumber seedlings are placed on the three-dimensional layered flat net structure at both sides of the pond, and the density of sea cucumber seedlings placed in the middle of the three-dimensional layered flat net structure is higher than that of sea cucumber seedlings placed at both ends of the three-dimensional layered flat net structure; The three-dimensional layered flat net structure is a polyethylene net fixed in a pond, comprising three layers of flat nets arranged in sequence from top to bottom, the upper layer of flat net and the lower layer of flat net are horizontally arranged and extended, and the middle layer of flat net is extended in a V shape; a plurality of three-dimensional layered flat net structures are arranged in the pond in parallel at intervals, and each three-dimensional layered flat net structure is provided with two groups of cage nets in parallel on both sides, and the two groups of cage nets are arranged at intervals between adjacent three-dimensional layered flat net structures; each group of cage nets is composed of three cage nets arranged in a triangular shape; the adjacent cage net groups and the three-dimensional layered flat net structures are spaced apart by 3m, and the adjacent cage net groups are spaced apart by 2m; when the fry is released, the fry is placed on the upper layer of flat net.

[0013] The existing net cage in the cultivation of sea cucumbers is used for transition cultivation, and the fry is transferred from an indoor cultivation pond to a pond to adapt to the pond environment and improve the stress resistance, which belongs to high-density intensive intermediate cultivation, and is convenient for harvesting, and subsequent cultivation or growth in other modes. The activity space of the fry in the net cage is limited, and the self-feeding and activity ability is not high, and the muscle is not developed; the vertical netting is not easy to accumulate and settle the plankton and organic particles, and it is easy to cause insufficient feed of the sea cucumber; when the adhesion of the fry is not strong, it is easy to fall and gather at the bottom of the net cage, and the bottom of the net cage often causes the sea cucumber to spit dirt, peel and other adverse stress reactions (disadvantages).

[0014] The flat net attachment base provided by the present application has the same material as the internal attachment base of the net cage, and provides habitat for the fry. Through the arrangement of the three-dimensional compound structure of the flat net, the problems of small space for the fry to attach and inhabit and insufficient feed caused by the difficulty of the netting to accumulate and settle the sediment can be solved. Most importantly, the intermediate cultivation method in the present application is not transition cultivation, and the fry can be cultivated in the original pond after intermediate cultivation, and the cage nets on both sides can reduce the density of the fry, provide habitat for large-size fry, and meet the needs of different markets to cultivate multi-specification sea cucumber fry or commodity sea cucumber.

[0015] It should be noted that the sea cucumber fry is transported from the indoor to the pond, and the physical quality is weak, and the adhesion of the foot is relatively weak. In addition, the indoor environment and the pond environment are quite different, and the fry needs to adapt.

[0016] The flat net of the present application can provide appropriate buffering for the fry, and the vertical attachment base in the net cage is easy to fall to the bottom of the net cage when the adhesion of the fry is not strong. With the extension of time, the internal environment of the net cage is easy to cause internal oxygen deficiency due to the blockage of the netting, and the adhesion of the fry will be poor under the stress conditions of poor environmental conditions at the bottom.

[0017] The flat net is easy to accumulate and settle the plankton and organic particles, and can also supplement the benthic diatoms, solving the problem of insufficient feed; the structure of the three-dimensional attachment base increases the habitat and activity space of the fry.

[0018] The smaller the size is, the lower the seedling price is, and the more the number of seedlings is put in, the method can continue to cultivate large-size seedlings in the original pond, so that the loss of seedlings in the process of intermediate transportation and adaptation is avoided, the survival rate of seedlings is improved, the number of seedlings is increased, and the resistance of seedlings is improved, so that the cost of seedling input is greatly reduced.

[0019] As to the seedling feeding mode of the present application, 5000-6000 head / kg of seedlings, 10000-20000 head / kg of seedlings, and 50000-60000 head / kg of seedlings can be selected according to actual conditions.

[0020] In some embodiments, the feeding selection ratio of 5000-6000 head / kg of seedlings, 10000-20000 head / kg of seedlings, and 50000-60000 head / kg of seedlings is 2:4:4, and the seedling feeding density is that 5000-6000 head / kg of seedlings are fed at 25 kg / mu, 10000-20000 head / kg of seedlings are fed at 25-30 kg / mu, and 50000-60000 head / kg of seedlings are fed at 30 kg / mu.

[0021] In some embodiments, when the seedlings are fed, 5000-6000 head / kg of seedlings are fed on the first three-dimensional layered flat net structure at both sides of the pond, and 10000-20000 head / kg of seedlings and 50000-60000 head / kg of seedlings are fed on the second three-dimensional layered flat net structure in the middle of the pond; the number of the first three-dimensional layered flat net structure accounts for 40% of the total number of three-dimensional layered flat net structures, and the number of the second three-dimensional layered flat net structure accounts for 60% of the total number of three-dimensional layered flat net structures.

[0022] In some embodiments, the bait is fed in stages, including: In the intermediate cultivation stage, when the body length of the seedlings is less than 1 mm, the bait is fed at 1-2% of the body weight of the seedlings, the bait is diluted with water when feeding, and is uniformly sprayed on the flat net for the sea cucumber seedlings to lick after the bait is attached after sinking; when the body length of the seedlings is 1-10 mm, the bait is fed at 2-3% of the body weight of the seedlings; In the seedling cultivation stage, when the body length of the seedlings is greater than 1 cm, the bait is fed at 3-5% of the body weight of the seedlings, and the bait is uniformly sprayed around the cage net.

[0023] In some embodiments, in the intermediate cultivation stage, algal powder and compound feed are mainly used, and beneficial microbial agents are matched, and marshy Rhodopseudomonas is sprayed every 5-7 days for nutrition strengthening, and is sprayed on the flat net and the bottom of the pond at a quantity of 2 L / mu per mu in the morning on sunny days. Seedling cultivation stage: after reaching 1000 heads / kg, the seedlings are fed with fermented feed, the fermented feed is selected by taking lactic acid bacteria as the main fermentation strain, the proportion of lactic acid bacteria is 2%, and 0.5-1% of yeast powder, 1-2% of spirulina powder and 0.5-1% of oligosaccharide are added at the same time, and the young seedling commercial compound feed is selected, the water-feed ratio is 1.75:1, the fermentation is sealed for 48-72h, the stirring is carried out in time, and the fermented feed is in a fluffy state when the fermentation is completed.

[0024] In some embodiments, the salinity of the pond is 28-33, the pH is 7.8-8.4, the pond size is 30-50 mu, the water depth is 1.2-1.5m, the bottom material is sand, hard sand or sand mud, and the pond bottom is not water leakage.

[0025] In some embodiments, water is raised first, then material is raised, the attached base is naturally hung with material, and the seedlings are raised for 10-15 days before the water is fertilized; the water depth is 80-100 cm for the first time, and the water is gradually added to the full pond, the inorganic nitrogen and phosphorus fertilizer is applied, the transparency is kept at 25-40 cm, and the 40-60 mesh double nets are arranged at the water inlet.

[0026] In some embodiments, the seedlings are released in June or no later than mid-July in spring when the water temperature is 15-18℃; the seedlings are released after 4pm.

[0027] In some embodiments, the activity state, feces shape and quantity, and bait residue of the seedlings are observed every day, and the feeding amount is adjusted according to the feeding and activity of the seedlings; the seedlings are fed at 4pm-6pm, and a small amount of feeding is carried out for multiple times.

[0028] In some embodiments, EM bacteria are scattered every 7-10 days after the seedlings are released to regulate the water quality, the amount of EM bacteria is 1L / mu per mu, the first amount of EM bacteria is doubled, the EM bacteria are scattered every 5-7 days during the high temperature period, and the oxygenation machine is started to oxygenate in the afternoon or in the early morning when the temperature is low.

[0029] Compared with the prior art, the beneficial effects of the present application are that: The present application provides a kind of intermediate cultivation method of sea cucumber seedlings, adopts the combination of flat net + cage net, flat net is the attachment base of intermediate cultivation of seedling, seedling is scattered on flat net when putting, flat net has the dual function of "attachment support + natural bait in-situ cultivation" (most of the internal mesh of the net cage is vertical), which improves the attachment rate and survival rate of seedlings;Cage net is the attachment base of seedling cultivation (conventional intermediate cultivation and seedling cultivation are segmented), which has the following characteristics: (1) save labor, reduce cost and increase benefit obviously: the setting of the attached base of the present application not only has very low cost, but also does not need to be cleaned or replaced regularly, greatly saving the labor cost. The seedlings of more than 10,000 per head can be put, greatly saving the input cost of seedlings, and prolonging the cultivation time of seedlings in the pond, thereby improving the stress resistance and quality of seedlings; (2) reduce seedling loss and improve output: through the combination and multi-dimensional design of the attached base, the full use of water space is realized, which is not limited by the space structure of the net cage, avoiding the uncontrollable factors such as mutual extrusion and environmental deterioration in high-density cultivation; by setting the attached base suitable for different stages, the density of seedlings can be dispersed, and seedlings of the same size can be gathered, which is beneficial to the improvement of the growth rate and uniformity of seedlings, and improves the output and quality of seedlings; (3) create a sea cucumber pond seedling cultivation mode: change the previous transition cultivation mode of cultivation in the middle of the net cage. After the seedlings are cultivated in the middle, the subsequent seedling cultivation can be carried out in the original pond, and large-size seedlings or commercial sea cucumbers can be produced, which has the advantages of simple operation, low management difficulty, high feasibility, strong practicality, easy popularization, etc., reduces the overall cultivation cost, improves the output per unit area, and constructs an efficient large-scale seedling cultivation mode (traditional sea cucumber intermediate cultivation and seedling cultivation are segmented mode); The present application provides a sea cucumber seedling intermediate cultivation method, which is beneficial to reduce risk and improve seedling output by combining different sizes; it is beneficial to gather seedlings of the same size by regional management, improve seedling growth rate and uniformity (sea cucumber growth difference is very large, and traditional net cage cultivation space is limited, which is easy to appear big seedlings pressing small seedlings phenomenon), and the cultivation mode can solve the seedling loss caused by seedling sorting, transfer transportation and environmental stress, and the original pond cultivation can realize the maximization of benefit. BRIEF DESCRIPTION OF DRAWINGS

[0030] Figure 1 The setting site map of the "Chuan" type attached base provided by the embodiment of the present application in the pond; Figure 2 The setting mode schematic view of the "Pin" type cage net group provided by the embodiment of the present application; Figure 3 The structure schematic view of the conventional sea cucumber net cage. DETAILED DESCRIPTION

[0031] The technical solutions in the specific embodiments of the present application will be described in detail and completely below with reference to the drawings. Obviously, the described embodiments are only part of the specific embodiments of the total technical solution of the present application, not all the embodiments. Based on the general concept of the present application, all other embodiments obtained by those skilled in the art fall within the scope of protection of the present application.

[0032] 1, attached base setting The “river” type sea cucumber pond breeding mode is composed of different combinations of substrates, flat nets (three layers of three-dimensional complex) for intermediate cultivation, and cage nets for seedling cultivation or growing up.

[0033] As shown in Figure 1 , the “river” type pond has flat nets (three layers of three-dimensional complex) in the middle and “pin” type conventional net cages on both sides. One group of flat nets is arranged in the middle of the two groups of net cages (unit combination: 2 net cages + 1 flat net + 2 net cages structure). The net cages and flat nets are spaced 3m apart, and the net cages are spaced 2m apart. The substrates run parallel to the long side of the pond, with a length determined by the length of the pond. The edge of the substrate is 5-6m away from the long side of the pond and 7-8m away from the wide side of the pond. N groups of “river” type substrates are arranged according to the width of the pond.

[0034] Three-dimensional layered flat net: The seedling substrate is a polyethylene net with 30-40 meshes and a width of 1m. The upper and bottom nets are horizontal, and the middle net is arranged in a “V” shape. The upper and middle nets are prevented from rolling by support pipes. The pipes are fixed to PVC industrial pipes at both ends and in the middle by multiple industrial ties, spaced 10-15cm apart. The width of the support pipe is 1m, and the diameter is 2-3cm. A support pipe is set every 8-10m to tighten the flat net, with both ends anchored in the pond mud, 3m away from the outermost brick. The ends of the support pipes are placed on two groups of stone strips or cement strips or bamboo pile frames as vertical supports. The bricks are 80cm high and 10-15cm wide, with a spacing of 80cm between them. The middle net is fixed to the bottom by bricks with a spacing of 3-4m in the middle of the two groups of support pipes, forming a wavy shape.

[0035] “Pin” type cage net: The cage net is a conventional sea cucumber net cage as shown in Figure 3 , arranged in a “pin” shape as shown in Figure 2 , with a three-layer structure.

[0036] 2. Seedling release 2.1 Release of seedlings by size: Release size: 5000-6000 heads / kg, 10-20 thousand heads / kg, 50-60 thousand heads / kg. Large size is combined with small size, and each size can be released in proportion to the actual situation. Small size can be more than large size, and the optimal ratio of each size is 2:4:4 (the size of the intermediate cultivation in the conventional net cage is more than 10 thousand heads / kg).

[0037] Release density: 5000-6000 heads / kg of sea cucumber seedlings are released at 25 kg / mu, 10-20 thousand heads / kg of sea cucumber seedlings are released at 25-30 kg / mu, and sea cucumber seedlings with a size of more than 20 thousand heads / kg are released at 30 kg / mu.

[0038] 2.2 Regional management: Method of releasing seedlings: The number of flat nets is used as the reference site for releasing seedlings, 5000-6000 heads / kg are released on both sides of the pond, accounting for 40% of the number of flat nets (20% on both sides), 1-2 million heads / kg or 5-6 million heads / kg (60% of the number of flat nets in the middle) are released in the middle. When releasing, evenly sprinkle the seedlings onto the flat net, release small-sized seedlings in the middle of the pond, and the larger the size, the farther to the side. According to the number of attached bases laid in the pond, sprinkle, and it is appropriate for the density in the middle of the pond to be slightly higher than that on both sides.

[0039] 2.3 Subsection type cultivation: Middle cultivation stage: When the body length is less than 1 mm, feed according to 1-2% of the body weight of the seedlings. Mainly use algal powder (such as ground seaweed and sargassum powder) and compound feed, if necessary, filter with silk gauze, and add beneficial microbial agents (EM bacteria, photosynthetic bacteria, etc.) to improve water quality and strengthen nutrition, aid digestion. Sprinkle Rhodopseudomonas palustris every 5-7 days for nutrition enhancement, and apply in the morning on sunny days, sprinkle 2L / acre on the pond bottom, which can also purify water and increase the dissolved oxygen content of the water body. When the body length is in the range of 1-10 mm, feed according to 2-3% of the body weight of the seedlings.

[0040] Seedling cultivation stage: When the body length is greater than 1 cm, feed according to 3-5% of the body weight of the seedlings. After the size reaches 1000 heads / kg, perform bait feeding, and feed fermented feed. When fermenting feed, choose lactic acid bacteria as the main fermentation strain, and the liquid is best. The addition ratio is 2%, and 0.5-1% of yeast powder can be added at the same time. As needed, 1-2% of spirulina powder and 0.5-1% of oligosaccharides can be added. Juvenile sea cucumber commodity compound feed can be selected, the water-feed ratio is 1.75:1, and sealed fermentation is performed for 48-72h. Stir regularly, and the fermented feed is fluffy when fermentation is complete.

[0041] Feeding method: Dilute the bait during the middle cultivation stage, evenly sprinkle it on the flat net, and let the sea cucumber seedlings lick the bait after it settles and adheres. During the seedling cultivation stage, evenly sprinkle it around the net.

[0042] 3. Method: 3.1 Pond selection and environmental optimization The water source should be sufficient, fresh and fertile, without pollution, and without a large amount of fresh water injection. The water quality requires stable salinity throughout the year, with a salinity range of 28-33 and a pH range of 7.8-8.4. The pond is less than 50 mu, generally 30-50 mu, with a water depth of 1.2-1.5m and a maximum water depth of more than 2m. The bottom is sand, hard mud sand, or sand mud, and the pond bottom is not leaking. Use cement boards or stones to protect the slope. Level the bottom of the cultivation pond, and lay impermeable plastic cloth on the bottom under soft and rotten conditions to adapt to the growth of sea cucumbers.

[0043] When the external tidal water condition is good, sea water is introduced, water is bred first, then material is bred, the adhering base is naturally hung with material, and the seedling fertilizer water is placed for 10-15 days. The water depth is 80-100 cm for the first time, the water is gradually added to the full pond, the inorganic fertilizer of nitrogen and phosphorus is appropriately applied, the transparency is kept at 25 cm-40 cm. The water inlet is provided with 2 sets of 40-60 mesh screens.

[0044] 3.2 Selection and transportation of seedlings The selected sea cucumber seedlings are transported after being stopped feeding for 2-3 days. The transportation is dry transportation with ice.

[0045] 3.3 Seedling release The seedling release time is June in spring, and the latest is not more than mid-July. The seedlings are released in sunny days with water temperature lower than 20℃ (optimally 15-18℃) (the seedlings are not released in windy and stormy days). The seedling release operation is started after 4 pm.

[0046] 3.4 Management Precise feeding: the activity state (stretching and adhering), feces shape and quantity, and bait residue of the seedlings are observed every day, which is the most direct index for judging feeding and health. The feeding amount is adjusted according to the feeding and activity of the seedlings. The feeding time is selected from 4 pm to 6 pm, and the seedlings are fed in small amounts and multiple times. When the water temperature is suitable (15-25℃), the feeding amount can be appropriately increased in the fast growth period.

[0047] Environmental regulation: the water quality is regulated by spraying EM bacteria and other microecological agents every 7-10 days after the seedlings are released. The spraying amount is 1 L per mu, and the first spraying amount is doubled. The microecological agents are sprayed every 5-7 days in the high temperature period, and the oxygen is increased. The oxygenation machine is started in the afternoon or in the early morning when the temperature is low.

[0048] In order to more clearly and specifically introduce the sea cucumber seedling intermediate cultivation method provided by the embodiment of the present application, the following will be described in combination with specific embodiments.

[0049] Embodiment 1 Qingdao Tianheng pond 1. Adhering base setting The “river” type sea cucumber pond breeding mode is composed of different adhering bases. The flat net (three-layer three-dimensional complex) is used for intermediate cultivation, and the cage net is used for seedling cultivation or breeding.

[0050] The selected pond is 35 mu, 500 m long and 40 m wide, and 13 groups of “river” type adhering bases are arranged. Among them: In the "Sichuan"-shaped pond, there is a flat net (three-layer three-dimensional compound type) in the middle, and "pin"-shaped conventional net cages on both sides. One group of flat nets is arranged between two groups of net cages (unit combination: the structure of 2 net cages + 1 flat net + 2 net cages). The distance between the net cages and the flat net is 3m, and the distance between the net cages is 2m. The direction of the attachment substrate is parallel to the long side of the pond, and its length is determined according to the length of the pond. The edge of the attachment substrate is 6m away from the long side of the pond and 8m away from the wide side of the pond. 13 groups of "Sichuan"-shaped attachment substrates are set according to the length of the pond.

[0051] Three-dimensional layered flat net: The seedling attachment substrate is a 40-mesh polyethylene net, 1m wide. The upper and bottom nets are horizontal, and the middle net is arranged in a "V" shape. The upper net and the middle net are prevented from curling by support pipes, and are fixed to the PVC industrial pipes at both ends and in the middle respectively with multiple industrial tie straps, with an interval of 15cm. The width of the support pipe is the same as that of the net, which is 1m, and the diameter is 2cm. A support pipe is set every 8m to tighten the flat net, and both ends are anchored in the pond bottom mud. The anchor points are 3m away from the outermost bricks. The two ends of the support pipe are respectively placed on two groups of stone strips or cement board strips or bamboo strip frameworks as vertical supports. The bricks are 80cm high and 15cm wide, and the interval between the bricks is 80cm. The middle net is fixed to the bottom with bricks at an interval of 4m between two groups of support pipes, forming a wavy shape.

[0052] "Pin"-shaped cage net: The cage net is a conventional sea cucumber net cage, and the net cages are arranged in a "pin" shape, with a three-layer structure.

[0053] 2. Seedling stocking 2.1 Stocking of seedlings by specifications: Select the selected sea cucumber seedlings with specifications of 5,000 - 6,000 heads per catty and 10,000 - 20,000 heads per catty, and the stocking density is 25 catties per mu. The stocking ratio of the two specifications of sea cucumber seedlings is 6:4.

[0054] 2.2 Zonal management: Stocking method: Take the number of flat nets set as the reference point for stocking seedlings. The seedlings of 5,000 - 6,000 heads per catty are stocked on both sides of the pond, accounting for 40% of the number of flat nets (20% on each side), and the seedlings of 10,000 - 20,000 heads per catty are stocked in the middle (60% of the number of flat nets in the middle). When stocking, sprinkle the sea cucumber seedlings evenly on the flat nets. The smaller-sized seedlings are stocked in the middle of the pond, and the larger the size, the closer to the two sides. Sprinkle according to the number of attachment substrates arranged in the pond, with the density in the middle of the pond slightly higher than that on both sides, and the density in the middle of the flat net slightly higher than that at both ends.

[0055] 2.3 Stage-by-stage cultivation: Middle cultivation stage: when the body length is less than 1mm, feed according to 1% of the body weight of the reference larvae. Mainly feed on algal powder (powdered kelp and sargassum) and compound feed, filter with silk screen if necessary, and add beneficial microbial agents (EM bacteria, photosynthetic bacteria) to improve water quality and nutrition, aid digestion. Spray Rhodopseudomonas palustris every 7 days for nutrition enhancement, preferably in the morning on sunny days, spray 2L / m2 on the pond bottom, which can also purify the water and increase the dissolved oxygen content of the water body. When the body length is between 1-10mm, feed according to 2% of the body weight of the reference larvae.

[0056] Seed cultivation stage: when the body length is greater than 1cm, feed according to 3% of the body weight of the reference larvae. When the size reaches 1000 individuals / kg, perform bait feeding, feed on fermented feed. Choose lactic acid bacteria as the main fermentation strain for fermented feed, preferably liquid, add 2% of the fermented feed, and simultaneously add 0.5% of the yeast powder. Add 1% of the spirulina powder and 0.5% of the oligosaccharides as needed. Choose juvenile sea cucumber commercial compound feed, water to feed ratio is 1.75:1, seal and ferment for 48 hours, stir regularly, and the fermented feed should be fluffy when finished.

[0057] Feeding method: dilute the bait during the middle cultivation stage, evenly sprinkle it on the flat net, and let the sea cucumber larvae lick the bait after it has settled and attached. During the seed cultivation stage, evenly sprinkle the bait around the flat net and cage net.

[0058] 3. Method 3.1 Pond selection and environmental optimization The water source should be sufficient, fresh, fertile, and free of pollution. No large amounts of fresh water should be injected. The water quality should be stable in terms of salinity, with a normal range of 28-33, and a normal pH range of 7.8-8.4. The pond is 35 mu, with a water depth of 1.5m, a maximum water depth of over 2m, and a bottom of sand, hard sand, or sand and mud. The pond bottom should be flat and the bottom should not leak water. Use cement boards or stones to protect the slope. Level the bottom of the cultivation pond, and if the bottom is soft and rotten, lay a plastic cloth to prevent leakage to adapt to the growth of sea cucumbers.

[0059] When the external tidal conditions are good, add seawater, first cultivate water, then cultivate feed, let the substrate naturally hang feed, and fertilize the water 10 days before releasing the larvae. The first water depth is 80cm, gradually add water to the full pond, and appropriately apply nitrogen and phosphorus inorganic fertilizer. The transparency should be maintained above 30cm. Set up 40 mesh 2-way blocking nets at the water inlet.

[0060] 3.2 Larvae selection and transportation Select sea cucumber seedlings that have been cultivated in the workshop, and release the larvae with a size of 5000-50000 individuals / kg, not more than 80000 individuals / kg. The selected sea cucumber seedlings are transported after 2 days of fasting. Dry transportation with ice is used.

[0061] 3.3 Larvae release Seedling stocking time: In the middle of June in spring. Stock seedlings on sunny days when the water temperature is above 15°C (it is not suitable to stock seedlings on windy days or during storms), and start the seedling stocking operation after 4 pm.

[0062] 3.4 Management Observe the activity status of the seedlings (stretching, attachment), the shape and quantity of feces, bait residues, etc. every day. These are the most direct indicators to judge feeding and health. Adjust the feeding amount according to the feeding and activity conditions of the seedlings. Choose the feeding time from 4 pm to 6 pm, and follow the principle of feeding in small amounts and multiple times. When the water temperature is suitable (15-25°C), the feeding amount can be appropriately increased during the rapid growth period.

[0063] Environmental regulation: After stocking seedlings, sprinkle EM bacteria and other probiotics to regulate the water quality every 10 days, at a rate of 1 L per mu. Double the amount for the first application. During the high-temperature period, sprinkle probiotics every 7 days, and pay attention to oxygenation. Turn on the aerator in the afternoon or in the early morning when the temperature is low.

[0064] 4. Growth situation (1) It grows to an average of 1000 heads per catty in two months and 600 heads per catty in three months. The harvested seedlings have good appearance, thick meat, low body moisture content, strong stress resistance, and both the survival rate and size can be improved.

[0065] (2) In May 2022, 5000 catties of sea cucumbers with a size of about 15 heads were harvested. By randomly sampling and testing in July 2022, the average size was 70 heads per catty; about 54% were of the size of 300 heads per catty, about 41% were of the size of 100 heads per catty, and about 5% were of the size of 30 heads per catty.

[0066] Example 2 Rizhao pond 1. Attachment base setting The "Sichuan"-type sea cucumber pond cultivation and breeding mode is composed of different attachment bases. Intermediate cultivation is carried out with flat nets (three-layer three-dimensional compound), and cage nets are used for seedling cultivation or grow-out.

[0067] The selected pond is 30 mu, and a total of 10 groups of "Sichuan"-type attachment bases are set. Among them: In the middle of the "Sichuan"-type pond is a flat net (three-layer three-dimensional compound), and on both sides are "pin"-shaped conventional cage nets. One group of flat nets is arranged between every two groups of cage nets (unit combination: the structure of 2 cage nets + 1 flat net + 2 cage nets). The distance between the cage net and the flat net is 3 m, and the distance between the cage nets is 2 m. The direction of the attachment base is parallel to the long side of the pond, and the length is determined according to the length of the pond. The edge of the attachment base is 8 m away from the long side of the pond and 7 m away from the wide side of the pond. 10 groups of "Sichuan"-type attachment bases are set according to the length of the pond.

[0068] Three-dimensional layered flat net: The seedling attachment base is a polyethylene net, 40 mesh, 1 m wide. The upper and bottom nets are horizontal, and the middle net is arranged in a "V" shape. The upper net and the middle net are prevented from curling by support pipes. At both ends and in the middle, they are fixed to PVC industrial pipes with multiple industrial straps at intervals of 10 cm. The width of the support pipe is the same as that of the net, which is 1 m, and the diameter is 2 cm. A support pipe is set every 8 m to tighten the flat net, and both ends are anchored in the pond bottom mud. The anchor points are 3 m away from the outermost bricks. The two ends of the support pipe are respectively placed on two groups of stone strips or cement board strips or bamboo strip pile frames as vertical supports. The bricks are 80 cm high and 15 cm wide, and the interval between the bricks is 80 cm. The middle net is fixed to the bottom with bricks at an interval of 4 m between the two groups of support pipes, forming a wavy shape.

[0069] "Pin"-shaped cage net: The cage net is a conventional sea cucumber cage net, and the cage nets are arranged in a "pin" shape with three layers of upper and lower structures.

[0070] 2. Seedling stocking 2.1 Stocking seedlings by different specifications: Select the selected seedlings. The selected sea cucumber seedlings are in three specifications: 5,000 - 6,000 heads per catty, 10,000 - 20,000 heads per catty, and 50,000 heads per catty. The stocking ratio of the three specifications of seedlings is 3:5:2. The stocking density is 25 catties per mu for the 5,000 - 6,000 heads per catty specification, and 30 catties per mu for the specifications above 10,000 heads per catty. At the end of June 2021, 500 catties of the 5,000 - 6,000 heads per catty specification were stocked, 800 catties of the 10,000 - 20,000 heads per catty specification were stocked, and 150 catties of the 50,000 heads per catty specification were stocked.

[0071] 2.2 Zonal management: Stocking method: Take the number of flat nets set as the reference site for stocking seedlings. The 5,000 - 6,000 heads per catty are stocked on both sides of the pond, accounting for 40% of the number of flat nets (20% on each side), and the 10,000 - 20,000 heads per catty or 50,000 heads per catty are stocked in the middle (60% of the number of flat nets in the middle). When stocking, sprinkle the sea cucumber seedlings evenly on the flat net. The smaller seedlings are stocked in the middle of the pond, and the larger the size, the closer to the two sides. Sprinkle according to the number of attachment bases arranged in the pond, with the density in the middle of the pond slightly higher than that on both sides, and the density in the middle of the flat net slightly higher than that at both ends.

[0072] 2.3 Step-by-step cultivation: Middle cultivation stage: when the body length is less than 1mm, feed according to 1% of the body weight of the reference larvae. Mainly feed on algal powder (kelp, mouse-tail algal powder) and compound feed, filter with silk screen if necessary, and add beneficial microbial agents (EM bacteria, photosynthetic bacteria) to improve water quality and strengthen nutrition, and help digestion. Spray Rhodopseudomonas palustris every 5 days to strengthen nutrition, and apply in the morning on sunny days, spray 2L / m2 on the pond bottom, which can also purify water and increase the dissolved oxygen content of the water body. When the body length is between 1-10mm, feed according to 2-3% of the body weight of the reference larvae.

[0073] Seed cultivation stage: when the body length is greater than 1cm, feed according to 4% of the body weight of the reference larvae. When the size reaches 1000 heads / kg, perform bait feeding, and feed fermented feed. Choose lactic acid bacteria as the main fermentation strain for fermented feed, and the liquid is best. Add 2% of the fermented feed, and at the same time, add 0.5% of the yeast powder. If necessary, add 1% of the spirulina powder and 0.5% of the oligosaccharide. You can also choose immature sea cucumber commercial compound feed, and the water to feed ratio is 1.75:1. Seal and ferment for 48 hours, and stir regularly. The fermented feed is fluffy when it is finished.

[0074] Feeding method: dilute the bait and evenly spray it on the flat net for the sea cucumber larvae to lick when feeding bait in the middle cultivation stage. In the seed cultivation stage, evenly spray the bait around the flat net and cage net.

[0075] 3. Method scheme: 3.1 Pond selection and environmental optimization The water source should be sufficient, fresh, fertile, and pollution-free. No large amount of fresh water should be injected. The water quality should be stable in salinity, with a range of 28-33, and pH should be between 7.8-8.4. The pond is generally 30 mu, with a water depth of 1.2m and a maximum water depth of more than 2m. The bottom is made of sand, hard mud sand, or sand mud, and the bottom is not leaking. Use cement boards or stones to protect the slope. Level the bottom of the cultivation pond, and if the bottom is soft and rotten, lay impermeable plastic cloth on the bottom to adapt to the growth of sea cucumbers.

[0076] When the external tidal conditions are good, add seawater first, then feed, and let the substrate naturally hang the bait. Fertilize the water 10 days before releasing the larvae. The initial water depth is 90m, and gradually add water to the full pond. Apply nitrogen and phosphorus inorganic fertilizer as needed, and maintain the transparency at 35cm. Set up 40-mesh 2-way blocking nets at the water inlet.

[0077] 3.2 Larvae selection and transportation Select sea cucumber seedlings that have been cultivated in the workshop, and release the larvae with a size of 5000 heads / kg-50000 heads / kg, not more than 80000 heads / kg. The selected sea cucumber seedlings are transported after stopping feeding for 2 days, and the transportation is dry with ice.

[0078] 3.3 Larvae release Release time: June 2021, water temperature 16℃ sunny day (not suitable for release in windy and stormy weather), release operation started after 4 pm.

[0079] 3.4 Management Observe the activity state (stretching, attachment), feces shape and quantity, and bait residue of the fry every day, which is the most direct indicator of feeding and health. Adjust the feeding amount according to the feeding and activity of the fry. The feeding time is selected from 4 pm to 6 pm, following the principle of small amount and multiple feeding. When the water temperature is suitable (15-25℃), the feeding amount can be appropriately increased during the rapid growth period.

[0080] Environmental regulation: Spray EM bacteria and other microecological preparations every 7 days after release to regulate water quality, apply 1L per mu, double the first spraying amount, spray microecological preparations every 5 days during high temperature period, and pay attention to oxygenation, turn on the oxygenation machine in the afternoon or early morning when the temperature is low.

[0081] 4. Growth In November 2022, the average size was 120 heads per kg, of which about 53% were 500 heads per kg, about 39% were 150 heads per kg, and about 8% were 50 heads per kg. The harvested fry had good appearance, thick flesh, and strong stress resistance.

Claims

1. A method for intermediate cultivation of sea cucumber seedlings, characterized in that, include: Evenly distribute 5,000-6,000 ginseng seedlings / jin, 10,000-20,000 ginseng seedlings / jin, and 50,000-60,000 ginseng seedlings / jin onto the three-dimensional layered flat net structure; place the smaller ginseng seedlings on the three-dimensional layered flat net structure in the middle of the pond, and place the larger ginseng seedlings on the three-dimensional layered flat net structures on both sides of the pond, and the density of ginseng seedlings in the middle of the three-dimensional layered flat net structure is higher than the density of ginseng seedlings at both ends of the three-dimensional layered flat net structure. The three-dimensional layered flat net structure is a polyethylene net fixed in the pond, consisting of three layers of flat net arranged from top to bottom. The upper and lower flat nets are horizontally set and extend, while the middle flat net extends in a V-shape. Several three-dimensional layered flat net structures are arranged parallel to each other in the pond. Each three-dimensional layered flat net structure has two sets of cage nets arranged parallel to each other on both sides. The two sets of cage nets are spaced apart between adjacent three-dimensional layered flat net structures. Each set of cage nets consists of three cage nets arranged in a triangular pattern. The interval between adjacent cage net sets and three-dimensional layered flat net structures is 3m, and the interval between adjacent cage net sets is 2m. When releasing the seedlings, place them on the upper layer of the flat net.

2. The intermediate cultivation method for sea cucumber seedlings according to claim 1, characterized in that, The stocking ratio for ginseng seedlings with a density of 5000-6000 heads / jin, 10000-20000 heads / jin, and 50000-60000 heads / jin is 2:4:

4. The stocking density is as follows: 25 jin / mu for 5000-6000 heads / jin, 25-30 jin / mu for 10000-20000 heads / jin, and 30 jin / mu for 50000-60000 heads / jin.

3. The intermediate cultivation method for sea cucumber seedlings according to claim 1, characterized in that, When releasing sea cucumber seedlings, seedlings of 5,000-6,000 heads / jin are released on the first three-dimensional tiered flat net structure on both sides of the pond, seedlings of 10,000-20,000 heads / jin and seedlings of 50,000-60,000 heads / jin are released on the second three-dimensional tiered flat net structure in the middle of the pond; the first three-dimensional tiered flat net structure accounts for 40% of the total number of three-dimensional tiered flat net structures, and the second three-dimensional tiered flat net structure accounts for 60% of the total number of three-dimensional tiered flat net structures.

4. The intermediate cultivation method for sea cucumber seedlings according to claim 1, characterized in that, The feed is introduced in stages, including: Intermediate cultivation stage: When the ginseng seedlings are less than 1mm in length, feed them at 1-2% of their body weight. Dilute the feed with water and sprinkle it evenly on the flat net. After the feed settles and adheres, the ginseng seedlings can lick it. When the ginseng seedlings are 1-10mm in length, feed them at 2-3% of their body weight. Seedling cultivation stage: When the ginseng seedlings are longer than 1cm, feed them at a rate of 3-5% of their body weight, spreading the feed evenly around the cage net.

5. The intermediate cultivation method for sea cucumber seedlings according to claim 4, characterized in that, Intermediate cultivation stage: mainly algae powder and compound feed, supplemented with beneficial microbial preparations, and Rhodopseudomonas palustris is sprayed every 5-7 days for nutritional fortification. On sunny mornings, it is sprayed on the flat net and the bottom of the pond at a rate of 2L / acre. Seedling cultivation stage: After the size reaches 1000 heads / jin, feed is introduced to induce feeding. Fermented feed is used, with lactic acid bacteria as the main fermentation strain, with an addition ratio of 2%. At the same time, 0.5-1% yeast powder, 1-2% spirulina powder and 0.5-1% oligosaccharides are added. Commercial compound feed for juvenile sea cucumbers is selected, with a water-to-feed ratio of 1.75:

1. The feed is sealed and fermented for 48-72 hours, and stirred regularly. When fermentation is complete, the feed will be in a fluffy state.

6. The intermediate cultivation method for sea cucumber seedlings according to claim 1, characterized in that, The pond has a salinity of 28-33, a pH of 7.8-8.4, a size of 30-50 mu, a water depth of 1.2-1.5m, and a bottom substrate of sand, gravel, hard mud, or sandy mud, and the bottom of the pond is watertight.

7. The intermediate cultivation method for sea cucumber seedlings according to claim 6, characterized in that, First, prepare the water, then the feed, allowing the substrate to naturally absorb the feed. Fertilize the water for 10-15 days before releasing the seedlings. Initially, fill the pond with water to a depth of 80-100cm, gradually adding water until the pond is full. Apply nitrogen and phosphorus inorganic fertilizers to fertilize the water, maintaining the transparency at 25cm-40cm. Install two 40-60 mesh screens at the water inlet.

8. The intermediate cultivation method for sea cucumber seedlings according to claim 1, characterized in that, The seedlings should be released in June or no later than mid-July; release the seedlings on a sunny day when the water temperature is 15-18℃, and start the seedling release operation after 4 pm.

9. The intermediate cultivation method for sea cucumber seedlings according to claim 1, characterized in that, Observe the seedlings’ activity status, feces shape and quantity, and feed residue every day, and adjust the feeding amount according to the seedlings’ feeding and activity. Feeding time is selected from 4 pm to 6 pm, and feed in small amounts and frequently.

10. The intermediate cultivation method for sea cucumber seedlings according to claim 9, characterized in that, After seedling introduction, apply EM bacteria every 7-10 days to regulate water quality at a rate of 1L / mu. Double the amount for the first application. During periods of high temperature, apply every 5-7 days and turn on the aerator in the afternoon or early morning when the temperature is low.

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