Whole-process factory cultivation technology for scylla paramamosain

Abstract

The invention relates to the related field of crab culture, in particular to a scylla paramamosain whole-process factory culture technology which comprises the following steps: preparing a culture cement pond; selecting juvenile crabs and treating the juvenile crabs before entering the pond; and daily breeding management. The whole-process culture of the seawater blue crabs under the indoor factory condition is realized for the first time, a new culture variety is provided for factory facilities, and the culture space can be effectively expanded and the total culture yield can be increased under the situation that the coastal mud flat area required by the current seawater crab culture is shrunk; according to the method, the required culture water body area is small, the unit culture density is high, culture conditions are controllable in the whole process, daily management is convenient, the method has remarkable advantages in the aspects of water quality regulation and control, bait utilization, disease prevention and control, natural disaster response and the like, and the culture survival rate is increased to 40% or above from 20% or below of a traditional method; the breeding density is increased to 5-10 pieces / m < 2 > from 3 pieces / m < 2 > or below; the cultivation yield per mu is increased from 50 kg to 460 kg, and the cultivation benefits are remarkably improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of crab breeding, and in particular to a whole-process factory breeding technology of Scylla paramamosain. BACKGROUND

[0002] Scylla paramamosain is an important economic species in seawater aquaculture in coastal provinces and cities in China. It is fast-growing and has a high market price, and is therefore very popular among aquaculture practitioners and consumers. In recent years, the market price has been stable with an upward trend, stimulating a breeding boom in coastal areas.

[0003] However, the current crab breeding still uses outdoor ponds, and the traditional mode of single or mixed breeding is adopted. The breeding density is low, the management is extensive, the production activities are greatly affected by the climate, and diseases occur frequently, resulting in a general survival rate of less than 10%. The average yield per mu is below 50 kg, and the uncontrollable sudden changes in weather (such as high temperature or sudden rain) during outdoor pond breeding can easily cause changes in water salinity, temperature, and algal phase, which can cause crabs to become ill or die due to stress, increasing the risk of crab breeding. As a result, the annual yield of Scylla paramamosain in China has been hovering around 160,000 tons, making it difficult to achieve a significant breakthrough and unable to meet the growing market demand. Therefore, it is urgent to develop new breeding modes and technologies to improve breeding yield and efficiency.

[0004] Compared with traditional outdoor large-area pond breeding, factory breeding requires less water area, has a high unit breeding density, and the breeding conditions are fully controllable, making it easy to manage daily. It has significant advantages in water quality control, feed utilization, disease prevention and control, and response to natural disasters, which can significantly improve breeding yield and efficiency.

[0005] In recent years, there have been attempts to use indoor facilities such as "crab apartments" to carry out intensive high-density breeding of Scylla paramamosain. However, the current technology can only achieve temporary breeding of outdoor-bred crabs, with a temporary breeding time of no more than 2 months. It can only be used to improve the quality and sales price of existing bred crabs, and cannot achieve factory whole-process breeding of crabs. In addition, the "thin crabs" needed for temporary breeding come from wild capture or pond breeding, and during the temporary breeding period, each crab needs to be individually operated for water change and feed feeding, which is complex and labor-intensive, making it difficult to be widely promoted. Therefore, it is difficult to solve the problem of low unit yield of crabs and insufficient market supply from the root. Therefore, it is of great significance to create an effective and practical whole-process factory breeding technology for crabs to achieve high-density breeding of crabs, which can fundamentally improve the yield of crabs and promote the development of crab breeding industry. SUMMARY

[0006] Therefore, the application provides a whole-process factory breeding technology of Scylla paramamosain, through which the whole-process breeding of Scylla paramamosain from fry to sexual maturity and reaching the specification of high-quality commercial crabs can be realized in a factory cement pool, compared with the existing breeding technology, the unit survival rate of Scylla paramamosain is increased by 113.75%, the breeding density is increased by 100%, and the breeding yield is increased by 360.60%. The whole-cycle factory breeding of crabs is realized for the first time, which lays a good foundation for promoting the innovation of high-density factory breeding mode of Scylla paramamosain and promoting the development of Scylla paramamosain breeding industry.

[0007] In order to achieve the above-mentioned purpose, the application adopts the following technical scheme: a whole-process factory breeding technology of Scylla paramamosain, comprising the following steps:

[0008] S1, preparation of a breeding cement pool:

[0009] S11, selection of pond specification

[0010] S12, arrangement of an air inlet

[0011] S13, laying of a pool bottom

[0012] S14, putting of a shelter;

[0013] S2, selection and pre-pooling treatment of crab fry:

[0014] S21, selection of fry specification and hatching time

[0015] S22, treatment of fry

[0016] S23, fry stocking density

[0017] S3, daily breeding management:

[0018] S31, water quality parameter requirement

[0019] S32, regular water change

[0020] S33, bait feeding

[0021] S34, disease prevention and control

[0022] S35, water salinity control

[0023] S36, regular cleaning and measurement.

[0024] Preferably, the step S1, preparation of a breeding cement pool, specifically comprises the following steps:

[0025] S11, selection of pond specification: an indoor semi-buried rectangular cement pool is used as a breeding pool, and the length-width ratio of the cement pool is 5:3;

[0026] S12, air head arrangement: evenly lay air heads in the pool, the air head arrangement density is 1m 2 / each;

[0027] S13, pool bottom laying: lay 7-10cm thickness of fine sea sand on the pool bottom, the bottom of the sand layer is 2-3cm high with 60 mesh silk screen, the air head in the sand laying area is placed under the sand layer; the sand laying area is generally about 2 / 3 of the pool bottom area, which is laid near the water inlet; about 1 / 3 area is reserved on one side of the drain without sand laying, which is used as the place for mud crab feeding activities;

[0028] S14, shelter putting: in different stages of mud crab breeding, different specifications and types of shelters are put according to the size of mud crab.

[0029] Preferably, the step S2, crab fry selection and pre-pooling treatment, specifically includes the following steps:

[0030] S21, selection of fry size and hatching time:

[0031] S211, fry size: selecting healthy and vigorous larva II period (C2) two-day-old artificial whole fry of Aratus pisonii;

[0032] S212, hatching time: the hatching time of fry is selected in the afternoon of two-day-old:

[0033] S22, fry treatment:

[0034] S221, after the fry is hatched, it is washed with clean seawater, and then soaked with 0.3g / m 3 of Vc for 15min;

[0035] S222, before entering the pool, the fry is medicated with 2mg / L KMnO4 solution for 15min:

[0036] S23, fry stocking density: the stocking density is 5-10 / m 2 , the temperature difference between the water temperature of the pool and the fry pool is not more than 2℃, and the salinity change is not more than 5‰.

[0037] Preferably, the step S3, daily breeding management, specifically includes the following steps:

[0038] S31, water quality parameter requirement: the salinity is controlled at 10-25‰ during the whole breeding process, and the salinity is adjusted accordingly according to the different development stages; the water temperature is controlled at 20-31℃, the dissolved oxygen (Do) is ≥6mg / L, the pH value is 7.9-8.0, the ammonia nitrogen NH3-N is <0.5mg / L, the nitrite is <0.1mg / L, and the hydrogen sulfide is <0.1mg / L;

[0039] S32, regular water change: from June to early July, the indoor water temperature is below 28℃, and the water is changed once a day, with a water change amount of 80%-100%; when the indoor water temperature exceeds 28℃ in mid-July, the breeding pond should be cultivated with flowing water all day, and the flowing water amount is 100-200% of the 24h flowing water amount; if the indoor water temperature exceeds 32℃ without cooling measures in the high-temperature season, the 24h flowing water amount should be more than 300%, to ensure that the breeding water temperature does not exceed 30℃;

[0040] S33, bait feeding: the type of bait is selected according to the size of the crab larvae;

[0041] S34, disease prevention and control: in order to prevent the outbreak of diseases, the strategy of prevention first and combination of prevention and control is adopted during the whole breeding period to control the diseases during the breeding period;

[0042] S35, water salinity control: taking advantage of the growth characteristics of Scylla paramamosain, such as fast growth at low salinity, full gonadal development at high salinity, and molting rhythm consistent with tides, under indoor breeding conditions, on the one hand, the salinity of the breeding water is scientifically adjusted according to the growth and development stages of Scylla paramamosain, to improve the growth rate of Scylla paramamosain and promote gonadal development; on the other hand, the salinity of the water is adjusted before the spring tide to stimulate the synchronous molting of the breeding Scylla paramamosain and reduce the individual killing caused by asynchronous molting of Scylla paramamosain;

[0043] S36, regular cleaning and measurement: the residual bait, feces, dead individuals are cleaned and removed in time every morning, and the growth status of Scylla paramamosain is measured regularly.

[0044] Preferably, the step S33, bait feeding, specifically comprises the following steps:

[0045] S331, bait type:

[0046] For crab larvae with a shell width of less than 5cm, shelled shrimp, surimi, etc. are fed; for crab larvae with a shell width of more than 5cm, fresh shellfish, miscellaneous fish, etc. are fed.

[0047] S332, feeding frequency: feeding once a day, between 18:00-19:00 in the afternoon, and the residual bait and pollutants in the pond are cleaned and removed before 9:00 in the morning of the next day, and the bait amount is adjusted according to the residual bait;

[0048] S333, feeding amount: the daily feeding amount of Scylla paramamosain decreases with the increase of individual body weight due to different development stages; the daily feeding amount accounts for 25-30% of the body weight of the crab larvae when the shell width is 3-4cm; 15-20% of the body weight when the shell width is 5-6cm; and 8-10% of the body weight when the shell width is more than 7cm;

[0049] S334, bait quality: ensure fresh bait, do not feed the bait of deterioration, so as to avoid the deterioration of water quality and affect the growth and health of the mud crab; small fish, shrimp, fresh shellfish can be cleaned and directly fed, and large fish can be cut and washed before feeding; the bait should be evenly fed in the pool bottom area without sand, and cannot be fed too concentratedly to avoid the death caused by the fight for food.

[0050] Preferably, the step S34, disease prevention and control, specifically comprises the following steps:

[0051] S341, strictly control the water quality during the cultivation, measure the water temperature, dissolved oxygen (Do), pH, ammonia nitrogen, nitrite and other water quality indicators every day, according to the water quality, change the water, flow the water, clean the residual bait, pollutants and other in the pool regularly, and the water for cultivation is disinfected by ultraviolet after sand filtration;

[0052] S342, according to the number of pathogenic bacteria in the cultivation water body and the health status of the crab larvae, the lactic acid bacteria, bacillus, EM bacteria and photosynthetic bacteria are used alternately to control the environment in the cultivation pool; in high temperature season, the flow rate is increased, and the disinfectants such as povidone-iodine and potassium permanganate are used regularly to control the concentration of ammonia nitrogen, nitrite and hydrogen sulfide in the pool;

[0053] S343, in the middle and later stages of cultivation, when the mud crab carapace width reaches more than 5cm, the aquatic Vc and multi-vitamin are used according to the product instructions by mixing or spraying in the whole pool every day to improve the body condition of the mud crab.

[0054] The beneficial effects of the present application are:

[0055] 1, the present application realizes the whole process cultivation of seawater crabs under indoor factory conditions for the first time, compared with the existing method which can only be used for short-term temporary cultivation and fattening, the present application provides a new cultivation variety for factory facilities, which can effectively expand the cultivation space and improve the total yield of cultivation under the current situation of shrinking of the required coastal beach area for seawater crab cultivation.

[0056] 2, the present application requires small cultivation water area, high unit cultivation density, and the cultivation conditions are controllable throughout the process, which is convenient for daily management, and has significant advantages in water quality regulation, bait utilization, disease prevention and control, and response to natural disasters, etc., and the survival rate of mud crab is increased from 20% to more than 40% by the traditional method, and the yield per mu is increased from 50kg to 460kg, which realizes the significant improvement of the cultivation benefit.

[0057] 3、The application provides a new technical means for continuous preservation of excellent germplasm of swimming crabs such as Scylla paramamosain, construction of breeding lines and tracking of whole-process traits, and development of new breeding techniques. Through whole-process cultivation of excellent germplasm from seedlings to sexual maturity under controllable factory conditions indoors, more than 2 swimming crabs per square meter can be cultivated, and more than 3 square meters of area is required for cultivating 1 swimming crab under outdoor pond conditions. The application can effectively solve a series of problems in the traditional outdoor pond conditions, such as the influence of climate conditions on germplasm preservation and breeding line construction, the large space required for line construction, high cost, difficulty in recapture, easy mixing of germplasm between ponds, and difficulty in accurately tracking traits, especially in the research and application of new breeding techniques such as genomic selection and gene editing. The cultivation environment is completely controllable, the number of individuals per unit of water is large, and the operation is convenient, so that the technical advantages are obvious. BRIEF DESCRIPTION OF DRAWINGS

[0058] Figure 1 is a prepared cultivation pond schematic diagram of the application;

[0059] Figure 2 is a schematic diagram of the application of a ready-to-use water aquaculture pond;

[0060] Figure 3 is a schematic diagram of the shelter in the pond of the application;

[0061] Figure 4 is a schematic diagram of the full artificial Scylla paramamosain C2 seedlings released into the pond of the application;

[0062] Figure 5 is a schematic diagram of the early-stage juvenile crabs of the application;

[0063] Figure 6 is a schematic diagram of the juvenile crabs in the middle stage of cultivation of the application, and the weight of the juvenile crabs is 5g per crab;

[0064] Figure 7 is a schematic diagram of the swimming crabs at the harvest stage of the application, wherein the left drawing is a female crab, and the right drawing is a male crab; the shape of the abdomen of the female and male individuals shows that the reproductive molting has been completed. DETAILED DESCRIPTION

[0065] In order to further explain the technical scheme of the application, the following specific embodiments are described in detail.

[0066] The application provides a whole-process factory cultivation technology of Scylla paramamosain, comprising the following steps:

[0067] S1, preparation of a cement pond for cultivation

[0068] S11, selection of pond specifications

[0069] S12, arrangement of air inflation heads

[0070] S13, laying of the pond bottom

[0071] S14, shelter putting;

[0072] S2, crab seed selection and pre-pooling treatment:

[0073] S21, seed size and hatching time selection

[0074] S22, seed treatment

[0075] S23, seed stocking density;

[0076] S3, daily breeding management:

[0077] S31, water quality parameter requirement

[0078] S32, regular water change

[0079] S33, bait feeding

[0080] S34, disease prevention and control

[0081] S35, water salinity control

[0082] S36, regular cleaning measurement.

[0083] Step S1, preparation of a breeding concrete pool, specifically comprising the following steps:

[0084] S11, selection of pond specifications: indoor semi-buried rectangular concrete pool as breeding pool, the length-width ratio of the concrete pool is 5:3;

[0085] S12, air head arrangement: evenly laying air heads in the pool, the air head arrangement density is 1m 2 / individual;

[0086] S13, bottom laying: laying 7-10cm thick fine sea sand on the bottom, the bottom of the sand layer is 60 mesh silk with 2-3cm air space, the air head in the sand laying area is placed under the sand layer; the sand laying area is generally about 2 / 3 of the bottom area, close to the water inlet; about 1 / 3 of the area is not used for sand laying on one side of the drain, as the place for green crabs to eat, as shown in Figure 1 and Figure 2 ;

[0087] S14, shelter putting: in different stages of green crab breeding, different specifications and types of shelters are put according to the size of green crabs, so that crabs can find shelter before molting to prevent self-injury and improve the yield and survival rate of pseudolatent green crabs.

[0088] The present application adopts the combination of biology and physics to select, cultivate and put the shelter, specifically as follows:

[0089] S141, juvenile crab weight below 30g

[0090] The pond is not shaded above, and before the fry is released, the fixed algae such as water sponges is cultured in the bottom of the pond as a shelter for the early fry, and the algae covers 10-15% of the area of the pond;

[0091] S142, the body weight of the juvenile crab is 30-50g

[0092] As the size of the juvenile crab increases, the fixed algae cannot provide sufficient shelter for the juvenile crab, and a shading net with a shading rate of 95% is used above the sand area of the pond to shade 1 / 2 of the area of the pond, and a pottery jar with a diameter of 50mm and a height of 70mm is released, the pottery jar is open, and the jar body has no hole, as shown in Figure 3 , which facilitates the entry of the juvenile crab into the jar body and reduces the killing between individuals, and the number of released is 20% of the number of fry released, 1 / 3 of which is released in the sand area, and 2 / 3 is released in the sand-free feeding area, and the fixed algae cultured in the early stage is removed to prevent the algae from dying and rotting and deteriorating the water quality after shading above the pond;

[0093] S143, the body weight of the juvenile crab is 50-200g

[0094] A black plastic cup with a diameter of 100mm and a length of 150mm is released in the pond, the plastic cup is open, and the cup wall is perforated to facilitate the exchange of water inside and outside the plastic cup where the large-sized mud crab hides, as shown in Figure 3 , the plastic cup is installed with a counterweight and released into the fry pond, and the number of released is 25% of the number of fry released, 1 / 3 of which is released in the sand area, and 2 / 3 is released in the sand-free feeding area;

[0095] S144, the body weight of the juvenile crab is more than 200g

[0096] In addition to the black plastic cup, a PVC pipe with a diameter of 90-110mm and a length of 150-300mm is released in the pond, the PVC pipe is cut in the middle and placed in the bottom of the pond in an arch shape, or the complete PVC pipe is half-buried in the sand layer, and the number of released is 20% of the number of fry released, and in addition, in the sand area, a crab nest with a width of 150mm and a height of 50mm is built along the pool wall with tiles, and the number of crab nests is 10% of the number of fry released;

[0097] S145, pond disinfection

[0098] Before breeding, the whole pond is soaked and disinfected with 100ml / m 3 of sodium hypochlorite solution (effective chlorine 10%), the disinfection time is after 18:00 every day, the sodium hypochlorite solution is diluted by 1:100 seawater, and then it is sprinkled in the whole pond, the water is stirred for 5min, then the air is stopped, and after 24h, it is washed clean;

[0099] S146, water treatment

[0100] The clean seawater with salinity of 25-30‰, pH of 7.9-8.0 and DO of 6 mg / L is added to the culture pond, and the water depth is 80 cm. The seawater is treated by three-stage sand filtration and ultraviolet disinfection, and is ready for use after aeration;

[0101] S147, light control

[0102] According to the habit of Scylla paramamosain that hides at night, light is shielded by biological and physical methods to avoid the influence of too strong light on the growth of juvenile crabs. For the ponds with juvenile crabs weighing less than 30 g, no light shielding is performed, and aquatic plants such as water mites in the ponds are used to provide shelter for the juveniles. For the ponds with juvenile crabs weighing more than 30 g, a black shading net with a shading rate of 95% is used to cover 2 / 3 of the area of the ponds near the sand area on the top of the ponds. The light intensity under the shading net is controlled to be less than 1000 Lux to avoid too strong light and maintain a quiet environment. No light shielding is performed above the bait feeding area.

[0103] Step S2, crab seed selection and pre-treatment before entering the pond, specifically including the following steps:

[0104] S21, selection of seed size and hatching time:

[0105] S211, seed size: select healthy and vigorous larval crabs II (C2) two-day-old Scylla paramamosain artificial seed, as shown in Figure 4 ;

[0106] The larval crabs are selected as the second stage, and the same age seed is required to ensure the synchronization of molting during the cultivation process, so as to avoid the residual killing between individuals due to the different molting steps and ensure the survival rate of cultivation. Under normal cultivation conditions, the second stage of Scylla paramamosain seed needs 3 days to molt into the third stage of larval crabs, so two-day-old seed is selected to avoid the death caused by molting after three days of entering the pond and not adapting to the pond environment.

[0107] S212, hatching time: since the molting of Scylla paramamosain seed often occurs at night or early morning, in order to avoid the low survival rate of seed after entering the pond due to the incomplete hardening of the new shell, the seed hatching time is selected in the afternoon of the second day:

[0108] S22, seed treatment:

[0109] S221, after the seed hatches, the seed is cleaned with clean seawater, and then soaked with 0.3 g / m 3 of Vc for 15 min;

[0110] S222, before entering the pond, the crab seed is medicated with 2 mg / L KMnO4 solution for 15 min:

[0111] S23, seed stocking density: the stocking density is 5-10 crabs / m 2 , and the temperature difference between the water temperature in the pond and the seed pond is not more than 2℃, and the salinity change is not more than 5‰.

[0112] Step S3, daily farming management, specifically comprising the following steps:

[0113] S31, water quality parameter requirements: the salinity is controlled at 10-25‰ throughout the farming process, and the salinity is adjusted accordingly according to different development stages; the water temperature is controlled at 20-31℃, the dissolved oxygen (Do) is ≥6mg / L, the pH value is 7.9-8.0, the ammonia nitrogen NH3-N is <0.5mg / L, the nitrite is <0.1mg / L, and the hydrogen sulfide is <0.1mg / L;

[0114] S32, regular water change: from June to the beginning of July, the indoor water temperature is below 28℃, and the water is changed once a day, with a water change amount of 80%-100%; when the indoor water temperature exceeds 28℃ in mid-July, the breeding pond should be cultivated with flowing water all day, and the flowing water amount is 100-200% of the 24h flowing water amount; if the indoor water temperature exceeds 32℃ without cooling measures in the high-temperature season, the 24h flowing water amount should be more than 300%, to ensure that the temperature of the breeding water body does not exceed 30℃;

[0115] S33, bait feeding: the types of bait are selected according to the size of the crab larvae, and specific steps include the following:

[0116] S331, bait type:

[0117] When the carapace width of the crab larvae is below 3cm, shelled shrimp, surimi, etc. are fed;

[0118] When the carapace width is 3-4cm, “lan clam” (a small type of shellfish with a shell length of 0.5-1cm) and shelled shrimp can be fed, with a feeding ratio of 1:1;

[0119] When the carapace width is 5-6cm, mixed clams and small wild miscellaneous fish can be fed, with a feeding ratio of 1.5-2:1;

[0120] When the carapace width is more than 7cm, fresh wild miscellaneous fish is mainly fed, supplemented by mixed clams.

[0121] S332, feeding frequency: feeding is performed once a day, between 18:00-19:00, and the water is drained the next day before 9:00 to clean the residual bait and pollutants in the pond, and the bait amount is adjusted according to the residual bait;

[0122] S333, feeding amount: the daily feeding amount of the mud crab varies with different development stages, and the percentage of the daily feeding amount to the body weight of the individual decreases as the body weight of the individual increases; when the crab larvae enter the pond to a carapace width of 3-4cm, the daily feeding amount is about 25-30% of the body weight of the crab larvae; when the carapace width is 5-6cm, the daily feeding amount is about 15-20% of the body weight; and when the carapace width is more than 7cm, the daily feeding amount is about 8-10% of the body weight;

[0123] S334. Feed Quality: Ensure feed is fresh and do not feed spoiled or rotten feed to avoid polluting the water and affecting the healthy growth of mud crabs. Small fish, shrimp, and fresh shellfish can be washed and fed directly. Large fish should be chopped and rinsed before feeding. Feed should be evenly distributed in the unsanded areas at the bottom of the pond. Do not feed too concentratedly to avoid fighting and death among the mud crabs for food.

[0124] S34. Disease Prevention and Control: To prevent disease outbreaks, a prevention-oriented, combined prevention and control strategy is adopted throughout the entire breeding period. This includes the following steps:

[0125] S341. Strictly control the water quality during the breeding period. Measure water temperature, dissolved oxygen (Do), pH, ammonia nitrogen, nitrite and other water quality indicators at regular intervals every day. Change water regularly, run water regularly, clean up uneaten feed and waste in the pond regularly, and disinfect the breeding water with ultraviolet light after sand filtration.

[0126] S342. Based on the number of pathogenic bacteria in the aquaculture water and the health status of the crab larvae, regularly alternate the use of lactic acid bacteria, Bacillus, EM bacteria, and photosynthetic bacteria to control the environment inside the aquaculture pond; during the high-temperature season, increase the water flow and regularly use disinfectants such as povidone-iodine and potassium permanganate to control the concentration of ammonia nitrogen, nitrite, and hydrogen sulfide in the pond. The specific usage and dosage are as follows:

[0127] ① Lactic acid bacteria: Use when the water temperature is above 25℃, apply by sprinkling throughout the pond, at a dosage of ≥20×10⁸ CFU / m³ of live bacteria concentration. 3 Use once every 7-10 days, and spray in the evening, avoiding spraying during periods of strong sunlight;

[0128] ② Bacillus subtilis: Apply on a sunny morning at a dose of 0.5g / m³. 3 (live bacteria concentration ≥100×10) 8 CFU / g), Bacillus subtilis, brown sugar, and water are mixed in a 1:1:20 ratio, and after oxygenation and activation for 2 hours, the mixture is sprinkled throughout the pond. This is done once every 10-15 days.

[0129] ③EM bacteria: After fermenting the original solution for 5-7 days, dilute the fermentation broth 20 times and add it at a rate of 30ml / m 3 Apply the solution to the entire pond, once every two days.

[0130] ④ Photosynthetic bacteria: Dilute the commercial photosynthetic bacteria stock solution 10 times, and administer at a rate of 0.5 ml / m³. 3 Apply the solution to the entire pond on a sunny morning, once every 10-15 days.

[0131] ⑤ Povidone-iodine: 2 ppm, sprinkle throughout the pond, change the water as usual 24 hours later, disinfect once every 10-15 days normally, use after water change if the water quality deteriorates or if the crabs die;

[0132] ⑥ Potassium permanganate: 10 ppm, whole pool, 100% water change after 2 hours of disinfection, normal disinfection every 10-15 days, water quality deterioration or after the death of the mud crab, use after water change;

[0133] ⑦ All probiotics and disinfectants cannot be used at the same time, disinfectants are used for 24 hours, or probiotics are replenished after water change.

[0134] S343, in the middle and later stages of breeding, when the mud crab shell width reaches more than 5 cm, daily through the method of mixing or whole pool pouring, according to the product instruction, using aquatic Vc and multi-vitamin to improve the body of the mud crab;

[0135] S35, water salinity control: water salinity is a key environmental factor affecting the growth and development of mud crab, and the mud crab has the characteristics of gradually tending to low salinity with growth, and the growth speed is fast under low salinity; the ovary development tends to high salinity, and the gonad development is full under high salinity, and the molting of the mud crab is consistent with the tidal rhythm, and the molting peak usually occurs during the spring tide, and in this stage, the salinity changes, especially the water salinity changes to low salinity, which can effectively stimulate the molting of the mud crab;

[0136] The present application utilizes the above growth and development characteristics of the mud crab, under indoor breeding conditions, on the one hand, with the change of the growth and development stage of the mud crab, the salinity of the breeding water is scientifically adjusted, the growth speed of the mud crab is improved, and the gonad development is promoted, see the table below; on the other hand, the water salinity is adjusted before the spring tide, the molting of the mud crab is stimulated, the individual residual killing caused by the asynchronous molting of the mud crab is reduced, and the survival rate of the indoor industrialized breeding of the mud crab is greatly improved. The specific operation method is as follows:

[0137] S351, suitable salinity range for each development stage:

[0138]

[0139]

[0140] Note: C2: second stage of juvenile crab

[0141] S352, salinity adjustment method: configure a low salinity or high salinity water storage pool beside the breeding pond, adjust the water salinity of the breeding pond by daily water change or water flow, the salinity of the water storage pool is the lower limit or upper limit of the salinity required by the mud crab at the present size, such as less than 5g in weight, the salinity of the water storage pool is 20 ‰, and more than 200g in weight, the salinity of the water storage pool is 25 ‰;

[0142] The specific salinity adjustment time and adjustment range are as follows:

[0143] ① When the body weight of the blue crab is less than 5 g, the molting cycle of the blue crab is short, and the blue crab needs to undergo 5-6 molting to grow from C2 to a body weight of 5 g. The salinity is reduced 2 days after each molting of the blue crab, and the salinity is reduced by 1 ‰ each time, with a reduction of 0.5 ‰ per day. The salinity is kept at the lower limit of the salinity in this stage, and daily management is performed.

[0144] ② When the body weight of the blue crab is 5-200 g, the molting cycle is more than 15 days, and is related to the tidal rhythm. The blue crab usually molts during the spring tide, so the salinity is adjusted 3 days after each molting. The salinity adjustment range is 0.3-0.5 ‰ / day. The salinity is reduced to the upper limit or the lower limit of the salinity in each body weight range 3-5 days before the spring tide, and daily management is performed.

[0145] ③ When the body weight of the blue crab is more than 200 g, the blue crab has mostly completed the reproductive molting. In particular, the development of the female crab gonad needs to be carried out in a high-salinity environment. After about 30 days of cultivation, the gonad is fully developed. Therefore, after the blue crab completes molting, the salinity is adjusted to 25 ‰ at a rate of 0.3-0.5 ‰ / day, and daily management is performed.

[0146] S36, Regular cleaning and measurement: When the continuous water temperature is above 31 ℃, the blue crab will die due to high temperature. In order to prevent the pool from being polluted by waste, leftover food, and excrement, which will deteriorate the water quality, the growth status of the blue crab needs to be measured regularly every 10-15 days, including the carapace length, carapace width, body weight, and weight gain during molting.

[0147] Specific implementation case

[0148] In 2024, indoor cement pools were used to carry out the whole process of cultivating blue crabs at the Rizhao Marine and Fisheries Research Institute. The cement pool specifications were length x width x height = 4.5 m x 3.7 m x 1.2 m, and the pool bottom was paved with sand according to the technical solution of the present application, as shown in Figure 1 and Figure 2 .

[0149] On June 18, 2024, artificially bred blue crab II-stage larvae were released, with a density of 6 / m 2 (100 per pool), and the whole process of indoor factory cultivation of the blue crab was carried out using the method of the present application. On November 7, 2024, the water was drained and harvested, and the number of blue crabs in each pond was counted, the specifications were calculated, and the survival rate and yield of cultivation were calculated. A total of 179 blue crabs were harvested, with an average survival rate of 44.75%, and the blue crabs all completed reproductive molting, as shown in Figure 7 , with an average body weight of 258.85 g. The specific conditions are shown in Table 1. The average unit yield was 690.55 g / m 2, which is converted into 460.6 kg per mu; compared with the existing highest survival rate of 20% of the mud crab culture, the highest density of 2000 seedlings per mu (about 3 / m 2 ), the highest yield of 100 kg per mu, and the average yield of 50 kg per mu, the survival rate, the culture density and the culture yield are greatly improved, the survival rate is increased by 113.75%, the culture density is increased by 100%, and the unit culture yield is increased by 360.6%, which has a significant technical advantage.

[0150] Table 1. Indoor factory culture data statistics of Scylla paramamosain

[0151]

[0152] The above only describes the preferred examples of the present application and is not used to limit the present application. Although the present application is described in detail with reference to the foregoing examples, those skilled in the art can still modify the technical solutions recorded in the foregoing examples or make equivalent replacement for some technical features. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A full-process factory breeding technology of Scylla paramamosain, characterized in that it comprises the following steps: S1, preparation of a cement pond for breeding; S11, selection of a pond specification S12, arrangement of an aeration head S13, laying of a pond bottom S14, putting of a shelter; S2, selection and pre-pooling treatment of crab larvae: S21, selection of a seed specification and timing of hatching S22, seed treatment S23, seed stocking density; S3, daily breeding management: S31, water quality parameter requirements S32, regular water change S33, bait feeding S34, disease prevention and control S35, water salinity control S36, regular cleaning and measurement.

2. The whole process industrial rearing technology of Scylla paramamosain according to claim 1, characterized in that: The step S1 of preparing a cement pond for breeding specifically comprises the following steps: S11, selection of a pond specification: a semi-buried rectangular cement pond is used as the breeding pond, and the length-width ratio of the cement pond is 5:3; S12, air inflation head arrangement: uniformly lay air inflation heads in the pool, the air inflation head arrangement density is 1m 2 / one; S13, laying of a pond bottom: 7-10 cm thick fine sea sand is laid on the pond bottom, the bottom of the sand layer is raised by 2-3 cm with a 60-mesh screen, and the aeration head is placed under the sand layer; the sand laying area is generally about 2 / 3 of the area of the pond bottom, and is laid near the water inlet; about 1 / 3 of the area on one side of the water outlet is not paved with sand, serving as a place for S. paramamosain to feed; S14, putting of a shelter: different specifications and types of shelters are put according to the size of S. paramamosain at different stages of breeding.

3. The whole process industrial rearing technology of Scylla paramamosain according to claim 1, characterized in that: The step S2 of selecting and pre-pooling treatment of crab larvae specifically comprises the following steps: S21, selection of a seed specification and timing of hatching: S211, seed specification: selecting healthy and vigorous S. paramamosain larvae of II stage (C2) two-day-old full artificial seed; S212, timing of hatching: the seed hatching time is selected in the afternoon of two-day-old: S22, seed treatment: S221, after the seedling emergence, use clean seawater to clean, use 0.3g / m 3 Soak with 0.3g / m2 of Vc for 15min; S222, before entering the pool, the larvae are medicated with 2 mg / L KMnO4 solution for 15 min: S23, stocking density: stocking density 5-10 / m 2 The temperature difference between the water temperature in the pool and the water temperature in the pond is not more than 2℃, and the salinity change is not more than 5‰.

4. The whole process industrial rearing technology of Scylla paramamosain according to claim 1, characterized in that: The step S3 of daily breeding management specifically comprises the following steps: S31, water quality parameter requirements: the whole breeding process salinity control 10-25 ‰, according to the different development stage of the corresponding adjustment of salinity; water temperature control in 20-31 ℃, dissolved oxygen (Do) ≥6 mg / L, pH value 7.9-8.0, ammonia nitrogen NH3 - N ＜ 0.5 mg / L, nitrite <0.1 mg / L, hydrogen sulfide in <0.1 mg / L; S32, regular water change: from June to early July, the water temperature in the pond is below 28℃, and the water is changed once a day, with a water change amount of 80%-100%; when the water temperature in the pond exceeds 28℃ in mid-July, the breeding pond should be continuously watered all day, with a flow rate of 100-200% of the total water body in 24 hours; if the water temperature in the pond exceeds 32℃ in the high-temperature season without cooling measures, the 24-hour flow rate should be more than 300% to ensure that the breeding water temperature does not exceed 30℃; S33, bait feeding: the type of bait is selected according to the size of the larvae; S34, disease prevention and control: in order to prevent the outbreak of diseases, the strategy of prevention first and combination of prevention and control is adopted during the whole breeding period to control the diseases during the breeding period; S35, water salinity control: taking advantage of the fact that S. paramamosain grows and develops at different speeds under different salinities and tends to molt during the spring tide, under indoor breeding conditions, on the one hand, the salinity of the breeding water is scientifically adjusted according to the growth and development stages of S. paramamosain, to improve the growth speed of S. paramamosain and promote the development of gonads; on the other hand, the salinity of the water is adjusted before the spring tide to stimulate S. paramamosain to molt synchronously, reducing the residual killing among individuals caused by different molting speeds of S. paramamosain; S36, regular cleaning measurement: clean up the leftover food, feces and dead individuals in time every morning, and measure the growth of the blue crab regularly.

5. The whole process industrial rearing technology of Scylla paramamosain according to claim 4, characterized in that: The step S33, bait feeding, specifically includes the following steps: S331, bait type: The crab larvae with a shell width less than 5 cm are fed with shrimp skin and surimi; and the crab larvae with a shell width more than 5 cm are fed with fresh shellfish and miscellaneous fish. S332, feeding frequency: feed once a day between 18:00 and 19:00, clean up the leftover food and feces in the pond before 9:00 the next day, and adjust the amount of bait according to the remaining bait; S333, feeding amount: the daily food intake of the blue crab decreases with the increase of the body weight of the individual at different development stages; the daily feeding amount accounts for 25-30% of the body weight of the crab larvae when the shell width is 3-4 cm, 15-20% of the body weight when the shell width is 5-6 cm, and 8-10% of the body weight when the shell width is more than 7 cm; S334, bait quality: ensure the freshness of the bait, and do not feed the deteriorated bait to avoid deteriorating the water quality and affecting the growth and health of the blue crab; small fish and shrimp, fresh shellfish, etc. can be directly fed after cleaning, and large fish can be fed after being cut and cleaned; the bait should be uniformly fed in the area with no sand on the bottom, and should not be too concentrated to avoid the death of the blue crab caused by fighting for food.

6. The whole process industrial rearing technology of Scylla paramamosain according to claim 4, characterized in that: The step S34, disease prevention and control, specifically includes the following steps: S341, strictly control the water quality during the cultivation, measure the water temperature, dissolved oxygen (Do), pH, ammonia nitrogen and nitrite water quality indicators regularly, and change the water, flow the water, clean up the leftover food and feces in the pond regularly, and use the sand-filtered water for cultivation; S342, according to the number of pathogenic bacteria in the cultivation water body and the health status of the crab larvae, regularly use lactic acid bacteria, bacillus, EM bacteria and photosynthetic bacteria to control the environment in the cultivation pond; increase the flow rate, use povidone-iodine and potassium permanganate disinfectant regularly in high-temperature seasons, and control the concentrations of ammonia nitrogen, nitrite and hydrogen sulfide in the pond; S343, in the middle and late stages of cultivation, when the shell width of the blue crab is more than 5 cm, use water products Vc and multi-vitamins to improve the physical fitness of the blue crab by mixing or spraying in the whole pond according to the product instructions.

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