CN114600809A

CN114600809A - Method for polyculture of prawns and scylla paramamosain in saline-alkali pond along yellow watershed

Info

Publication number: CN114600809A
Application number: CN202210231017.2A
Authority: CN
Inventors: 翟鹏; 翟万博; 翟来雁; 万春
Original assignee: Inner Mongolia Chunyangui Ecological Agriculture Technology Co ltd; Zhejiang Chunguiyan Ecological Agricultural Technology Co ltd
Current assignee: Inner Mongolia Chunyangui Ecological Agriculture Technology Co ltd; Zhejiang Chunguiyan Ecological Agricultural Technology Co ltd
Priority date: 2022-03-10
Filing date: 2022-03-10
Publication date: 2022-06-10

Abstract

The invention discloses a method for polyculture of prawns and scylla paramamosain in a saline-alkali pond along a yellow watershed, which comprises the following steps: preparation of a culture pond, transportation and stocking of varieties, daily management and harvest. The invention provides a pond polyculture method and a process for prawns and scylla paramamosain by utilizing saline-alkali soil and saline-alkali water along a yellow watershed, which realize the high-efficiency mixed culture of two famous and super-high-quality aquatic products by utilizing the saline-alkali water, can fully utilize the saline-alkali water resource of the saline-alkali soil along the yellow watershed in China, improve the economic benefit of fisherman culture, and are an effective culture mode.

Description

Method for polyculture of prawns and scylla paramamosain in saline-alkali pond along yellow watershed

Technical Field

The invention relates to the technical field of aquaculture, in particular to a method for polyculture of prawns and scylla paramamosain by utilizing a saline-alkali pond along a yellow watershed.

Background

Penaeus vannamei Boone (Penaeus vannamei Boone, 1931) schoolPenaeus vannamei, belonging to the genera Arthropoda (Arthropoda), Crustacea (Crustacea), Decapoda (Decapoda), Hyponeidea (Natania), Penaeidae (Penaeidae), Penaeus (Penaeus), Lito-Penaeus, is a wide-temperature, wide-salt tropical shrimp. Commonly known as: also called white-leg shrimp (white-leg shrimp) and white prawn (white shrimp)_，The prawn is one of the most popular aquaculture varieties in China and is also the prawn product with the largest aquaculture yield in China. Scylla paramamosain (scyllaparamosain), commonly known as Acipenser rubrum, Eriocheir sinensis, Henle crab, midge, mud crab, belonging to Crustacea, Tenpoda, Brachida, Halocyanidae, and Scylla. The Scylla paramamosain is an advantageous species for cultivating Scylla paramamosain in China, has delicious meat taste, rich nutrition, quick growth and strong stress resistance, can be used as a medicine, and is an excellent aquaculture variety.

The scale of the culture of the penaeus vannamei boone and the scylla paramamosain in coastal areas of China is continuously enlarged, the culture yield is increased year by year, but with the promotion of policies such as national ecological civilization construction, green development of aquaculture industry and the like, the aquaculture water resource is limited, farmland is occupied, environment is polluted and the like, the aquaculture industry in coastal areas is renovated, the culture area is greatly reduced, the culture yield is reduced as the diseases of the penaeus vannamei boone and the scylla paramamosain are more and more increased along with the continuous increase of the culture density in coastal areas, and on the other hand, the consumption of the penaeus vannamei boone and the scylla paramamosain in China is continuously increased. In the face of the contradiction, the development of a new culture area along the yellow river basin becomes a key way for solving the problem by combining the biological characteristics of the broad-salinity of the prawns and the scylla paramamosain.

Land and water resources are indispensable for two basic factors for culturing the prawns and the green mud crabs, while saline-alkali soil (water) with the quantity of more than 21 hundred million acres is not effectively utilized in China, and low-lying saline-alkali water areas and saline water areas with the quantity of about 6.9 hundred million acres inland provide a wide platform for culturing the penaeus vannamei and the green mud crabs, and saline water in the saline-alkali soil which is not effectively used can be utilized as culture water. The saline-alkali water in the saline-alkali soil is used for breeding the shrimps and the crabs, so that the soil can be improved, economic benefits can be generated, and the shrimp and the crabs can be obtained by killing two birds with one stone. When the shrimps and crabs are harvested, a large amount of salt and alkali can be taken away from the original saline-alkali water, and the method is favorable for the treatment of saline-alkali soil. In addition, the water in the pond raises the underground water level, is favorable for plant growth, and fixes soil to avoid desertification. Therefore, the method for culturing the shrimps and crabs in the pond by using the saline-alkali water along the yellow watershed not only can fill the culturing gap of the shrimps and crabs in coastal areas, but also can effectively utilize the saline-alkali soil which can not be used for planting crops, and has great significance for developing green aquaculture industry in China.

However, saline-alkali water is chemically complex and has various types because its cause is related to the environment in the field, geological soil, climate, and the like. The ratio and the content of main ions of the saline-alkali water are greatly different from those of seawater, the buffering capacity is poor, and the constant ratio relation of main components of the seawater and a stable carbonate buffering system are not provided. The saline-alkali water has the characteristics of high pH value, high carbonate alkalinity, high ionic coefficient and various types. Therefore, the saline-alkali water cannot be directly used for the cultivation of the shrimps and crabs, the water quality improvement becomes the difficulty of utilizing the saline-alkali water, the requirements of the shrimps and crabs on growth can be met only by adjusting the ionic components and changing the water through the water quality improver and the aquatic organisms, and the difficulty is high, and no relevant report on the aspect exists at present.

Disclosure of Invention

Aiming at the problems, the invention provides a method capable of realizing the mixed culture of prawns and scylla paramamosain.

The technical scheme provided by the invention is as follows:

a method for polyculture of prawns and scylla paramamosain in a saline-alkali pond along a yellow watershed comprises the following steps:

1) preparing a culture pond:

1.1 selection of culture pond: selecting areas with good water source and water quality, sufficient water quantity, far away from industrial parks and low pollution in the culture pond sites, wherein the pond bottom is a pond with sand or a mixture of sand and red mud bottom, the depth of the culture pond is 1.5-2m, the culture water depth is 1.5 m, and the thickness of sludge at the bottom of the pond is 5cm at most;

1.2 sterilizing culture ponds: draining the pond water to expose the pond before seedling placement, removing impurities in the pond, loosening and leveling the ridge, and splashing quicklime or bleaching powder to disinfect the whole pond in the half month before seedling placement;

1.3 Pond shelter setup: after the pond is aired for 20 days, concealed objects are placed in the pond according to grid arrangement and are used for increasing the space for concealing and movably inhabiting the scylla paramamosain;

1.4 water quality regulation: after the pond is sunned, 1000-1500kg of base fertilizer is applied to each mu, and the base fertilizer comprises the following components in parts by weight: 200-260 parts of chicken manure, 20-30 parts of soybean meal, 30-40 parts of corn straw, 20-30 parts of sunflower stalk, 18-26 parts of rice bran and 25-35 parts of rice hull; then filtering the inlet water through a 80-mesh screen till the water depth is 30-40cm for later use;

controlling the water depth to be 30-40cm 10 days before seedling placement, and applying 20mg/l of nitrogen fertilizer and 2mg/l of phosphate fertilizer after regulating water through base fertilizer to enable pool water to be dark brown, yellow green or yellow brown, so that the water quality is kept fresh during the whole culture period, and the transparency is 30-40 cm;

1.5 planting the aquatic weeds: planting the aquatic plants in the pond, wherein the planting area accounts for 1/3 of the area of the pond;

1.6 arrangement of escape-proof facilities: constructing escape-proof walls around the culture pond, wherein the walls are surrounded by double-layer materials; the upper part of the soil is fixed by using a wooden pile, the wooden pile inclines 15 degrees towards the interior of the pond, and the lower end of the soil is laterally pressed by using bricks or tamped by filling soil;

2) breed stocking:

2.1 shrimp larvae transportation and release: when the water temperature is controlled to reach 16 ℃, artificial seedlings which are uniform in size, free of leukoderma viruses, complete in attached branches, normal in swimming, free of attachments on the body surface and strong in water leaving and bouncing capacity, are desalted and thickened to be 1.5-3cm in specification are selected for putting;

soaking the crab seedlings for half an hour by using 5ppm povidone iodine, then soaking the shrimp seedling bags in pond water for 20-40min, controlling the temperature difference within 2 ℃, unfastening the shrimp seedling bags, gradually pouring saline alkali water in the pond into the shrimp seedling bags, and putting the shrimp seedlings into the pond after adapting to the culture water;

after a group of shrimp larvae is used for testing water, the shrimp larvae can move normally and then are released in large batch;

2.2 transporting and putting green mud crab seedlings in the cave: when the prawn grows to 2-3cm, putting the crab larva desalted to the salinity of 1-5 per mill in the crab larva cultivation area, and fishing the desalted and cultivated five-finger crab larva;

soaking the crab seedlings for half an hour by using 5ppm povidone iodine, mixing the transported seawater and saline water in a culture area according to the proportion of 9:1, 8:2, 7:3, 6:4, 5:5, 4:6, 3:7, 2:8 and 1:9 or according to the proportion of 8:2, 6:4, 4:6 and 2:8, temporarily culturing the crab seedlings in each proportion for 12-24 hours, and finally putting the crab seedlings into a culture pond.

3) Daily management:

3.1 pond breeding management: feeding the feed by adopting the principle of 'two-end concentrated feed and intermediate green feed', and mixing amino acid, compound multivitamin, calcium, potassium powder, immune polysaccharide and chitosan at the middle and later stages;

feeding shrimp feed: after 15-20 days of putting seedlings, selecting a formula feed specification according to the change of the body length of the penaeus vannamei boone for feeding, and when the body length of the penaeus vannamei boone is 3-10 cm, putting bait according to 8% of the wet weight; when the body length is 10cm, adjusting the value to 5%; the daily feeding frequency increases along with the weight of the Penaeus vannamei Boone, and is increased from 2 times a day to 4 times a day, and the Penaeus vannamei Boone is placed in a deep water area in the daytime and in a shallow water area at night; the water temperature is higher than 32 ℃ or lower than 22 ℃, and the feeding is reduced by 20-40% under the conditions of water change, algae pouring, raining and molting;

crab feeding: after crab seedlings are fed, adding crab feed on the basis of the original shrimp feed, wherein the feeding type and daily feeding amount are related to the size of the scylla paramamosain individual; feeding for 2 or 3 times according to the temperature, feeding 30% of the total food intake in the morning at 8-9 and 70% at the evening at 17-18, and spreading at fixed points along the shallow water of the pond edge;

when the temperature is 22-32 deg.C, feeding for 1 time in the morning, evening and the first half night, and when the temperature is lower than 22 deg.C or higher than 32 deg.C, the feeding amount should be reduced by 20-40% under the conditions of water change, algae pouring, rain and molting;

3.2 water quality management: regularly putting a water quality modifier into the culture pond, wherein the putting method comprises the steps of firstly using quicklime to disinfect culture water, putting one of photosynthetic bacteria and Em bacteria after 5 days, and then disinfecting after 15 days, and circulating once every 15 days after entering a high-temperature season; keeping the water level at 30-40cm when the daily average temperature is below 25 ℃ in the initial culture period, increasing the illumination to improve the water temperature and the dissolved oxygen in the water body; as the temperature rises, the water level gradually deepens;

3.3 disease control: in the whole culture process, the seedlings are strictly disinfected, the pond is disinfected, the culture water is disinfected, the feed is disinfected, and the disinfectant is regularly splashed in the whole pond in high-temperature seasons;

4) harvesting:

after more than 3 months of culture, the water temperature of the fish pond is more than 16 ℃, the prawn is caught when the length is not less than 8cm, and the single blue crab is caught when the weight reaches 150g-300 g.

Further, in the process of stocking the variety, 6000-8000 larvae per mu are thrown, the artemia are thrown into the breeding pond after 3-5 days of throwing, the artemia are thrown according to the amount of 2-2.5kg per mu, and the artemia are thrown once in the morning and afternoon every day and are continuously thrown for 3 days.

Furthermore, in the planting process of the aquatic weeds, the aquatic weeds comprise sinking plants, floating plants and emergent aquatic plants, the proportion of the sinking plants, the floating plants and the emergent aquatic plants respectively accounts for 1/3, the aquatic weeds are planted within 2 meters near the bank of the pond, and the row spacing is 3-4 m.

Further, in the feeding step, before the weight of the Scylla paramamosain is 20 g, mixed feed of wheat grains, corn grains, bran and fish meal is fed, and after the weight of the Scylla paramamosain is 20 g, the soaked mixture of wheat, corn, cooked rice grains, small fish and shrimp is directly fed;

feeding small trash fish in the middle ten days of the month 6, and feeding sunflower cakes, bean cakes and cooked corn kernels in a matched manner; feeding the weeds in the water at 7 months, feeding the cooked corn kernels, the small trash fishes, the shrimps and the fresh water screws, feeding the cooked corn, the small trash fishes, the screws, the blue-har and the oysters in the middle ten days of 8 months to 9 months, increasing the unshelling nutrition of the Scylla paramamosain and increasing the weight of the Scylla paramamosain, wherein the feeding ratio is 2:3: 5.

Further, water is added frequently in the water quality management process for 2-4 times per month, water is injected for 10cm each time, the pool water is fresh, alive and tender and cool, the water color is yellow green or yellow brown, the transparency of the pool water is 30-40cm, the pH of the aquaculture water body is kept at 7.8-8.6, the ammonia nitrogen is not more than 1mg/l, the dissolved oxygen is not less than 5mg/l, and the dissolved oxygen in the water body is less than 5mg/l, so that oxygen is increased by using an oxygen increasing machine.

Compared with the prior art, the invention has the advantages that:

the method for polyculture of prawns and scylla paramamosain in saline-alkali soil ponds along yellow watershed, provided by the invention, realizes high-efficiency mixed culture of two famous and super-high-quality aquatic products by utilizing saline-alkali soil water in the saline-alkali soil, can fully utilize saline-alkali water resources in the saline-alkali soil, improves the economic benefit of fisherman culture, and is an effective culture mode;

by adopting the aquaculture method provided by the invention to cultivate, the yield of aquaculture can be improved, the aquaculture stability can be ensured in the implementation process, the aquaculture stability requirement can be met, the aquaculture yield is improved, and the labor load of farmers in the aquaculture process is reduced.

Detailed Description

The present invention will be described in further detail with reference to examples.

The invention comprises the preparation of culture ponds, the transportation and stocking of varieties, daily management and harvest. The specific contents thereof are as follows.

1 preparation of the culture ponds

1.1 selection of cultivation ponds

The site of the culture pond selects an area with good water quality and sufficient water quantity, which is far away from an industrial park and causes little pollution. The culture pond is convenient to water inlet and drain, the bottom material of the pond is preferably a pond formed by sand or a pond formed by mixing sand and red mud, the aeration performance is good, the bottom of the pond is guaranteed not to leak, the water retention is good, the pond is not easy to collapse, the depth of the culture pond is 1.5-2m, the deepest culture water level is 1.5 m, the thickness of sludge at the bottom of the pond is generally not more than 5cm, and the area of the culture pond is 5-10 mu. At least one set of 3 kilowatt aerator is arranged per mu. The pond ridge of the aquaculture pond must be leveled, and the leak is filled to prevent the green crabs from escaping. The removed sludge can be used for reinforcing the dam, a 'return' annular ditch is excavated around the position 2m away from the inner side of the pond dam, the width of the ditch is 5-6 m, the depth of the ditch is 0.6-0.8 m, and the dry pond is solarized for later use.

1.2 Disinfection of cultivation ponds

Draining water in the pond to solarize the pond before putting the fry, removing impurities in the pond, scarifying and ridging, prolonging the pond solarizing time to more than 20d as far as possible, splashing quicklime or bleaching powder to disinfect the whole pond in half a month before putting the fry, and killing harmful organisms in the crab pond, wherein the using amount is 20-30 kg/mu.

1.3 Pond shelter setup

At least one concealed object of ceramic pipes, meshes, brick tiles, hollow bricks, cement pipes and the like is arranged in the pond according to the grid arrangement after the pond is sunned for 20 days, so that the space for concealing and movably inhabiting the scylla paramamosain is increased, the scylla paramamosain is dispersed, the encounter is reduced, and the culture survival rate is improved.

1.4 Water quality control

After the pond is sunned, 1000-1500kg of base fertilizer is applied to each mu, and the base fertilizer comprises the following components in parts by weight: 200-260 parts of chicken manure, 20-30 parts of soybean meal, 30-40 parts of corn straw, 20-30 parts of sunflower stalk, 18-26 parts of rice bran and 25-35 parts of rice hull; then filtering the inlet water through a 80-mesh screen till the water depth is 30-40cm for later use.

Controlling the water depth to be 30-40cm before seedling placing 10 days, after regulating water through a base fertilizer, applying 20mg/l of nitrogen fertilizer and 2mg/l of phosphate fertilizer to enable the pond water to be dark brown, yellow green or yellow brown, keeping the water quality fresh during the whole culture period, and enabling the water color to be yellow green or yellow brown and the transparency to be 30-40 cm.

1.5 aquatic weed planting

Aquatic plants are planted in the pond, and the planting area occupies 1/3 of the area of the pond. The aquatic plants include submerged plants, floating plants, and emergent aquatic plants, and their proportion is 1/3. The submerged aquatic weeds are planted by mixing one or two of waterweed, watermifoil, potamogeton ricini, potamogeton crispus, hydrilla verticillata, goldfish algae, and eel grass, the floating plants are planted by mixing water peanuts or water hyacinth or two, and the emergent aquatic plants are planted by mixing one or two of calamus, water shallot, loosestrife, and lotus flower. The aquatic weeds are planted within 2 meters near the bank of the pond, and the row spacing is 3-4 m. The aquatic weeds have the functions of providing natural feed for the shrimps and the crabs, hiding places, and achieving the advantages of purifying water quality, increasing dissolved oxygen, shading and avoiding summer heat, improving water body environment, improving the quality of the shrimps and the crabs and the like.

1.6 arrangement of escape-proof facilities

An anti-escape wall is constructed around the culture pond by using one of materials such as geomembrane, smooth polyethylene woven cloth and the like, and the wall body is surrounded by double-layer materials with the soil depth of 30 cm and the soil depth of 40-50 cm. The soil upper part is fixed by using a wooden pile, the wooden pile inclines 15 degrees towards the pond, and the soil lower end is laterally pressed by using bricks or tamped by filling soil.

2 stocking of variety

2.1 shrimp larvae transportation and delivery

5 in the middle of the month, when the water temperature reaches 16 ℃, artificial seedlings which are uniform in size, free of leukoderma viruses, complete in attached branches, normal in swimming, free of attachments on the body surface and strong in water leaving bouncing capacity, are desalted and thickened to the specification of 1.5-3cm are selected for putting. The method comprises the steps of selecting a windward head of a pond to breed shrimp seeds in the afternoon of a sunny day, soaking the crab seeds for half an hour by using 5ppm povidone iodine, then soaking shrimp seed bags in pond water for 20-40min, controlling the temperature difference within 2 ℃, unfastening the shrimp seed bags, gradually filling saline alkali water in the pond into the shrimp seed bags, and putting the shrimp seeds into the pond after the shrimp seeds are adaptive to water for breeding. After a group of shrimp larvae is used for testing water, the shrimp larvae can move normally and then put the larvae in a large batch. 6000 plus shrimp seedlings are thrown into each mu for 8000, artemia are thrown into the culture pond after 3-5 days of seedling throwing, and are thrown according to the amount of 2-2.5kg per mu, and are thrown once in the morning and afternoon every day for 3 days continuously.

2.2 transporting and putting green mud crab

When the prawn grows to 2-3cm, putting in crab seedling, selecting natural crab seedling in sea area or artificial crab seedling cultured according to organic aquaculture principle from the young scylla paramamosain, and desalting crab seedling to proper salinity of 1-5 ‰inthe crab seedling culture area. The crab seed carapace is green, the specification is neat, the body is complete, the reaction is sensitive, and the vitality is strong. Fishing and placing desalted and cultured five-finger crab seedlings (with the width of the head and chest nails being 1.5cm) into a plastic box or a foam box, adding no water into a transport box, ensuring that the size is not too small and the density is not too high, proposing 50cm multiplied by 50cm, placing 200 crab seedlings in each box, placing wet sponges and the like on the bottom layer, placing the crab seedlings, and then covering a layer of waterweed to preserve moisture. The transport time was controlled to be within 12 hours. During transportation, the crab seedlings are flatly placed as much as possible, the vibration pressure is reduced, the crab seedlings are dried in the weather during northern transportation, and the seawater spraying is carried out every 2 to 3 hours to ensure that the crab seedlings are wet. Before the crab seeds are put into a culture pond, the crab seeds are firstly put into a large basin, and the crab seeds are soaked for half an hour by using 5ppm povidone iodine. Then mixing the returned seawater and saline-alkali water in the culture area according to the proportion of 9:1, 8:2, 7:3, 6:4, 5:5, 4:6, 3:7, 2:8 and 1:9 or according to the proportion of 8:2, 6:4, 4:6 and 2:8, temporarily culturing the crab seedlings in each proportion for 12-24h, and finally putting the crab seedlings into a culture pond with the throwing density of 800 plus 1000 crabs per mu.

3 daily management

3.1 Pond rearing management

The feeding method is based on scientific feeding mode, and the principles of 'four fixed' (timing, fixed point, fixed quality and fixed quantity) and 'four views' (viewing season, weather, water color and food intake activity) are based on. The feeding principle adopted is 'fine at two ends and middle green'. The concentrated feed mainly comprises shrimp and crab compound feed on the market, and the green feed mainly comprises wheat, corn, cooked rice, small trash fish, shellfish and the like which are soaked in fresh and live bait in a matching way. It is not suitable for feeding rancidity and putrefaction feed, and can be mixed with appropriate amount of amino acids, compound multivitamins, calcium, potassium powder, immune polysaccharide, chitosan, etc. at middle and late stages.

Feeding shrimp feed: after 15-20 days of putting the seedlings, feeding the prawns with compound feed, selecting proper compound feed specification according to the change of the body length of the prawns, and feeding the prawns according to about 8% of the wet weight when the bodies of the prawns are 3-10 cm in length; when the body length is 10cm, the value can be adjusted to about 5%. The daily bait feeding frequency increases along with the weight of the penaeus vannamei boone, the bait feeding frequency is increased from 2 times in the first day to 4 times in the later period every day, the feeding needs to be carried out in the daytime and at night, the bait feeding frequency is put in a deep water area in the daytime, and the bait feeding frequency is put in a shallow water area at night. The water temperature is higher than 32 ℃ or lower than 22 ℃, the feeding is reduced by 20-40% under the conditions of water changing, algae pouring, raining and molting, and the feeding is not carried out during the water body disinfection period.

Crab feeding: after crab seedlings are fed, adding crab feed on the basis of the original shrimp feed, wherein the relationship and percentage of the feed feeding type, daily feed feeding amount and the individual size of the Scylla paramamosain are as follows: in the feeding step, before the weight of the Scylla paramamosain is 20 g, mixed feed of wheat grains, corn grains, bran and fish meal is fed, after the weight of the Scylla paramamosain is 20 g, the soaked wheat, corn, cooked rice grains, small fishes and shrimps are directly fed, small miscellaneous fishes are mainly fed in the middle ten days of 6 months, a small amount of sunflower cakes, bean cakes and cooked corn grains are fed, weeds in water begin to be fed in 7 months, the cooked corn grains and small miscellaneous fishes, small shrimps, screws and the like are fed, the edible cooked corns, small miscellaneous fishes, screws, blue-and-white shells, oysters and other shells are fed in the middle ten days of 8 to 9 months to increase nutrition of the Scylla paramamosain and molt nutrition of the Scylla paramamosain, and weight gain of the Scylla paramamosain, wherein the feeding ratio is 2:3: 5. The daily feeding amount is 10-15% of the total feed amount at the beginning of 6-7 months, the animal feed accounts for 35% of the total feed amount, the daily feeding amount of the Scylla paramamosain in 8 months accounts for 3-5% of the total feed amount, and the animal feed accounts for 25% of the total feed amount. Feeding crab feed for 2 or 3 times in a day according to the temperature, wherein the feeding time is 30% of the total food intake in the morning 8-9, and the feeding time is 70% in the evening 17-18. Spreading at fixed points along the shallow water of the pool edge. When the temperature is 22-32 deg.C, feeding for 1 time in the morning, evening and the first half night each day, and when the temperature is lower than 22 or higher than 32 deg.C, and under the conditions of water changing, algae pouring, raining and molting, the feeding amount should be reduced by 20-40%, and the feeding amount is not added during water body disinfection.

3.2 Water quality management

And regularly throwing photosynthetic bacteria, Em bacteria, quicklime and other water quality improving agents into the culture pond. The feeding method comprises sterilizing water for cultivation with quicklime at a dosage of 20-30 kg/mu. One of photosynthetic bacteria and Em bacteria is added after 5 days of disinfection, the adding amount is 6ppm-8ppm to improve the water quality, and the disinfection is carried out after 15 days. The circulation is carried out once every 15 days after entering the high-temperature season. Keeping the water level at 30-40cm when the daily average temperature is below 25 deg.C in the initial stage of cultivation, increasing illumination to increase water temperature, increasing dissolved oxygen in water, promoting aquatic plant growth and accelerating shrimp and crab growth. The water level should be gradually deepened to 1.5 m at the deepest as the temperature is gradually raised, and the daily average temperature is above 25 ℃. Due to the fact that northern climate is dry, evaporation capacity is large, pond leakage is added, water is added frequently during cultivation, water is injected for 2-4 times every month, water is injected for about 10cm every time, the pond water is fresh, alive and tender, the water color is yellow green or yellow brown, the transparency of the pond water is 30-40cm, the ph of a cultivation water body is kept to be 7.8-8.6, ammonia nitrogen is not more than 1mg/l, and dissolved oxygen is not less than 5 mg/l. When the dissolved oxygen in the water body is less than 5mg/L, an aerator is required to carry out oxygenation.

3.3 disease control

Once the disease of aquaculture species is hard to control, the prevention is mainly the main. 4 links such as fry disinfection, pond disinfection, cultivation water disinfection, feed disinfection and the like are strictly required in the whole cultivation process. In high temperature season, disinfectant such as garlicin and iodine preparation is sprinkled in the whole pool regularly.

4 harvesting

When the water temperature of a fishpond is above 16 ℃ after more than 3 months of culture, the prawn is harvested when the length of the prawn is not less than 8cm (80-50 heads/kg), and the weight of a single blue crab reaches about 150g-300 g. The prawns and the mud crabs are caught separately or at the same time, and the large and small prawns are caught and put on the market in batches.

The present invention and the embodiments thereof have been described above, but the description is not limited thereto, and the embodiments shown in the examples are only one of the embodiments of the present invention, and the actual content is not limited thereto. In conclusion, those skilled in the art should appreciate that they can readily use the disclosed conception and specific embodiments as a basis for designing or modifying other structures for carrying out the same purposes of the present invention without departing from the spirit and scope of the invention as defined by the appended claims.

Claims

1. A method for polyculture of prawns and scylla paramamosain in a saline-alkali pond along a yellow watershed is characterized by comprising the following steps:

1) preparing a culture pond:

1.1 selection of culture pond: selecting areas with good water source quality, sufficient water quantity, far away from industrial parks and little pollution in the culture pond sites, wherein the bottom materials of the ponds are sands or ponds formed by mixing sands with red mud bottom materials, the depth of the culture ponds is 1.5-2m, the culture water depth is 1.5 m, and the thickness of the sludge at the bottoms of the ponds is 5cm at most;

1.2 sterilizing culture ponds: draining water in the pond to solarize the pond before seedling placing, removing impurities in the pond, turning up and leveling the furrow, and splashing and disinfecting the whole pond by using quick lime or bleaching powder in the half month before seedling placing;

1.3 Pond shelter setup: after the pond is aired for 20 days, concealed objects are arranged in the pond according to grids and are used for increasing the space for concealing and movably inhabiting the scylla paramamosain;

1.5 planting the aquatic weeds: planting aquatic plants in the pond, wherein the planting area accounts for 1/3 of the area of the pond;

2) breed stocking:

soaking the crab seedlings for half an hour by using 5ppm povidone iodine, then soaking the shrimp seedling bags in pond water for 20-40min, controlling the temperature difference within 2 ℃, unfastening the shrimp seedling bags, gradually pouring saline alkali water in the pond into the shrimp seedling bags, and putting the shrimp seedlings into the pond after adapting to the culture water; after a group of shrimp larvae is used for testing water, the shrimp larvae can move normally and then put the larvae in a large batch;

soaking the crab seedlings for half an hour by using 5ppm povidone iodine, mixing the transported seawater and saline water in a culture area according to the proportion of 9:1, 8:2, 7:3, 6:4, 5:5, 4:6, 3:7, 2:8 and 1:9 or according to the proportion of 8:2, 6:4, 4:6 and 2:8, temporarily culturing the crab seedlings in each proportion for 12-24 hours, and finally putting the crab seedlings into a culture pond;

3) daily management:

feeding shrimp feed: after 15-20 days of putting seedlings, selecting a formula feed specification according to the change of the body length of the penaeus vannamei, and feeding the penaeus vannamei according to 8% of the wet weight when the body length of the penaeus vannamei is 3-10 cm; when the body length is 10cm, adjusting the value to 5%; the daily feeding frequency increases with the weight of the prawns, and increases from 2 times a day to 4 times a day, and the prawns are placed in a deep water area in the daytime and in a shallow water area at night; the water temperature is higher than 32 ℃ or lower than 22 ℃, and the feeding is reduced by 20-40% under the conditions of water change, algae pouring, raining and molting;

crab feeding: after crab seedlings are fed, adding crab feed on the basis of the original shrimp feed, wherein the feeding type and daily feeding amount are related to the size of the scylla paramamosain individual; feeding for 2 times or 3 times in a day according to the temperature, wherein the feeding amount is 30% of the total food intake in the morning 8-9, the feeding amount is 70% in the evening 17-18, and the food is spread at fixed points along the shallow water of the pond edge; when the temperature is 22-32 deg.C, feeding for 1 time in the morning, evening and the first half night, and when the temperature is lower than 22 deg.C or higher than 32 deg.C, the feeding amount should be reduced by 20-40% under the conditions of water change, algae pouring, rain and molting;

4) harvesting:

after more than 3 and a half months of culture, the water temperature of the fish pond is more than 16 ℃, the prawn is caught when the length is not less than 8cm, and the weight of a single blue crab reaches 150g-300 g.

2. The method as claimed in claim 1, wherein 6000-8000 shrimp seedlings are thrown per mu in the breeding process of the variety, and the artemia are thrown into the breeding pond after 3-5 days of throwing, 2-2.5kg per mu, and continuously thrown for 3 days in the morning and afternoon.

3. The method for co-cultivating prawns and scylla paramamosain along a yellow watershed by utilizing a saline-alkali pond, according to claim 1, is characterized in that in the aquatic weed planting process, the aquatic weed planting process comprises sinking plants, floating plants and emergent aquatic plants, the proportions of the sinking plants, the floating plants and the emergent aquatic plants respectively account for 1/3, the aquatic weeds are planted within 2 meters near the bank of the pond, and the row spacing is 3-4 m.

4. The method for polyculture of prawns and Scylla paramamosain along a yellow watershed by utilizing a saline-alkali pond, according to claim 1, wherein in the feeding step, the mixed feed of wheat grains, corn grains, bran and fish meal is fed before the Scylla paramamosain weighs 20 g, and the mixed feed of soaked wheat, corn, cooked rice grains, small fishes and prawns is directly fed after the Scylla paramamosain weighs 20 g;

feeding small trash fish at the beginning of 6 months, and feeding sunflower cakes, bean cakes and cooked corn kernels in a matching manner; feeding the weeds in the water and feeding the cooked corn kernels, the small trash fishes, the shrimps and the fresh water screws in 7 months, feeding the cooked corn kernels, the small trash fishes, the fresh water screws, the blue-har and the oysters in 8 months to 9 months, increasing the shelling nutrition of the Scylla paramamosain and increasing the weight gain of the Scylla paramamosain, wherein the feeding ratio is 2:3: 5.

5. The method for co-culturing prawns and Scylla paramamosain in a saline-alkali pond along a yellow river basin according to claim 1, wherein water is added frequently in the water quality management process for 2-4 times per month, 10cm is injected for each time, the pond water is guaranteed to be fresh, alive and tender, the water color is yellow green or yellow brown, the transparency of the pond water is 30-40cm, the ph of a culture water body is kept between 7.8 and 8.6, ammonia nitrogen is not more than 1mg/l, dissolved oxygen is not less than 5mg/l, and the dissolved oxygen in the water body is less than 5mg/l, so that oxygen enrichment is required by an aerator.