1 Variety price
1.1 Fresh shrimp
The new amount of shrimp (Metapenaeus ensis) is commonly known as girth shrimp, also known as sand shrimp, mud shrimp, soil shrimp, etc., belonging to the genus Shrimp and new genus Shrimp. It is distributed on the coasts of Guangdong and Fujian provinces in the south of the country. Its shell is thin and fat, and tender and delicious. , And strong vitality, often can live on the market, deeply welcomed by the domestic and foreign markets, is an important economy in China's offshore is one of the categories.
The amount of new blade shrimp body color yellow to brown, the upper edge of the forehead 6 to 9 teeth, no teeth on the lower edge, no central groove, the first tentacles on the whip is about 1/2 of the length of the head breastplate. The new amount of shrimp is a medium-sized species of shrimp, which is a relatively large species in the genus New Shrimp, but is smaller than the individuals of the genus Shrimp, and is generally 9.0 to 14 cm in length in the natural world, with a maximum body length of 16 cm under artificial breeding conditions. The individual size of the shrimp is usually 8 to 10 cm. The amount of new shrimp is widely distributed in the coastal waters south of the southern bank of the Shandong Peninsula in China, and its water depth distribution is also relatively wide. It is distributed in the shallow sea area on the 140m deep line, and the water depth is 20~50m. The sea area is dense. The inhabiting sediment is sand. Mud, silt, sand and mud. The amount of fish obtained in the sand and sediment-bearing waters was higher. The new amount of shrimp is also widely salty shrimp, ranging from 3.5% of the high salt water area to the brackish freshwater waters of the estuary. The adapted water temperature is encircled by 17°C to 32°C. Its activities are closely related to the weather and trends. When the weather is cold or when the water is clear and transparent, it lurks during the day and uses the technique to open the sand, form a cave, and bury the body in the cave, exposing only the eyes and tentacles. Climb out of the cave for food at dusk. The amount of new shrimp is omnivorous. Similar to shrimp in the larval stage, the shrimp prey-feeding benthic organisms are mainly food-plankton plankton and swimming creatures. It also feeds rotten baits in artificial breeding environments. The intensity of day and night changes in the intensity of ingestion is the lowest in the day, and it begins to rise at dusk and continues to increase at night and is highest in the morning. This is related to its low latency during the day and strong night activity.
Penaeus vanamei Boone (1993) was originally known as Penaeus vannamei, and was known as white-footed shrimp. It is native to the Pacific coast of Central and South America. It is one of the three largest shrimp species in the world with the highest aquaculture production (they are P. monodon, P. vannamei and P. chinensis). Artificial aquaculture in China began in the late 1980s. In the early 1990s, Taiwan was earlier than the mainland coast.
Similar to Chinese shrimps, Penaeus vannamei has a light, clear color and no markings. Compared with Chinese prawns, the muscles are slightly milky white, and the forehead does not exceed the second section of the first antennal shank, and is relatively short. The first antenna inside and outside the whip, etc. It is long and extremely short, and the maximum body length of shrimp is up to 23 cm. In aquaculture environment, it can reach 11-13 cm in general. Penaeus vannamei is a broad-salt tropical shrimp species that often inhabits in low-muddy seas. White pelican crawls or lurks in the lower surface of the sea. The activity is frequent at night, and it is pleasant to scare. The suitable water temperature is between 25°C and 32°C. Salinity At 2.8%-3.4%, the value is between 7.7 and 8.3. The water temperature during artificial rearing can be between 16°C and 35°C (gradient range), the salinity is between 0.05% and 4% (gradient range), and the pH value is between 7.3 and 8.6. . Penaeus vannamei has a wide range of dietary requirements and has a low requirement for food. The feed contains only 25% to 30% protein components. Can grow normally.
2 Freshwater aquaculture technology
2.1 The amount of new shrimp has a habit of dipping sand. Therefore, the bottom quality of the shrimp is good as a quality or silt. Penaeus vannamei does not have the habit of dipping sand, and mud can be of low quality. It is advisable to choose a rectangular table for shrimp ponds, with a plot of 1300 to 7000 m2 and a water depth of 1.2 to 1.5 m. The ring ditch or central ditch should be dug in the pool to facilitate dredging of water and shrimp habitat. The width of the ditch depends on the area of ​​the shrimp pond, usually 3 to 5m, and the depth is 0.5 to 1m. Dike slope 1: (2 ~ 2.5), the inlet at the bottom of the pool should be higher than the outlet, in order to use the drainage, the shrimp pond should have an independent drainage channel for drainage and irrigation. In short, it is required that the shrimp ponds have sufficient water sources, good water quality, solid soil, and convenient drainage. The original fish ponds can also be cultivated after being modified and refitted.
2.2 Preparations before stocking
2.2.1 Dredging and Disinfection of Ponds For the newly-created shrimp ponds, as long as they are exposed to sunlight for 2 to 3 days, they can enter the water. For the old ponds, it is necessary to dredge the sun for a long time, clean the pond weeds, and severely clear ponds. Method: 20 days before the stocking of shrimps, use lime 100kg per 667m2, first turn the quicklime in a small pool, heat it and splash it, or enter the bottom of the tank into 20~30cm water, and use 10~15kg of bleaching powder per 667m2. , Clear wild fish, scare, eliminate pathogenic microorganisms.
2.2.2 Cultivation of basic bait pond dredging disinfection began after 15d or so after the disappearance of the influent, the inlet with a 80-mesh sieve filtration, pre-inlet water 50 ~ 70cm, and then select the sunny fertilization material, in order to cultivate the basic bio-bait in the pool. Fertilizer can be used for every 667m2 of fermented ripening organic fertilizer 100 ~ 150kg, evenly spread, or with inorganic fertilizer per 667m2 urea 2kg, superphosphate 1kg, Quanchiposa. Inorganic fertilizers should be top-dressed once a day on alternate days. In general, 7-10 days, the water-transformed fertilizer is light yellow-green, and the transparency is 30 cm, indicating that the biological bait in the water is abundant, and the water temperature and pH value are determined. If these conditions are suitable, the seedlings can be planted.
2.2.3 Intermediate Culture of Shrimp Seedlings purchased from the nursery are only about 0.7 cm in length, and the physical quality is weak. The survival rate is poorly understood. In order to improve the survival rate of the shrimps, intermediate culture of the shrimps can be performed. When the shrimp grows to 2~3cm, it can be divided into seedlings and moved into the growing pool to continue feeding.
2.3 Seed stocking
2.3.1 Dehydration of seedlings Currently used for aquaculture New shrimp and Penaeus vannamei seedlings are mostly produced at the factory. The proportion of seawater used in nursery farming is generally 1.015 to 1.020. To move to freshwater, farming must first be domesticated and gradually diluted. Treatment. Therefore, the success or failure of freshwater aquaculture of Penaeus vannamei and Penaeus vannamei. The key lies in the desalination of shrimps, the good desalination of shrimp, the high survival rate, the possibility of successful breeding, otherwise, it may result in the annihilation of the entire army. The nursery manufacturers should gradually and progressively reduce the shrimp seedlings and forbade desalination. After several years of experience in production practice, the table sucks. Shrimp must be diluted to a water specific gravity of 1.003 before it can be directly transferred into freshwater aquaculture, and the entire desalination process must be completed gradually over 7 to 10 days.
2.3.2 seed quality requirements Seedling body length 0.7 ~ 1.0cm, strong physique, strong bouncing, the appearance of the surface clean and tidy, no adhesion of dirt, microscopic examination without pathogens, if possible, should be virus quarantine, shrimp Seed size specifications as uniform as possible.
2.3.3 Density of seedling density The density of seedlings in ponds shall be determined according to the conditions of shrimp ponds, water exchange conditions, feed supply conditions, seed size and breeding techniques, and management levels, and be determined according to the planned yield, specifications and expected survival rate of shrimp seedlings. And according to the planned output. The following formula can be used as a reference:
Per 667m2 seedling volume = planned production of shrimp requires an expected survival rate per kg of excretion at discharge
Under normal circumstances, the general survival rate of shrimp without intermediate culture is 30% to 40%, and the survival rate of the intermediate cultured shrimp is 70% to 80%. Since the farming cycle in northern areas such as Tianjin is shorter than that in the south, when considering the amount of seedlings to be transplanted, it is necessary to consider the specifications, but also to consider the yield. The ponds with the maximum number of new articles for shrimps can be placed in ponds with 0.7-1.0 cm in size. 5-6 Million/667m2. For example, 2cm or more of shrimp seedlings grown in the middle can be put in 2 to 30,000 tails per 667m2. Mixed with freshwater fish, the best stocking length is 2cm or more in the middle, and the amount of stocked fish is 10,000/667m2. Or as the case may be. Penaeus vannamei can lay 1.5 to 20,000 larvae with 0.7 cm of seedlings and 0.7 to 10,000 larvae that have been cultivated in the middle.
2.3.4 Restocking Time The constant water temperature of the new shrimp and Penaeus vannamei should not be lower than 18°C.
2.4 Aquaculture Management
2.4.1 Water quality management Water quality is the most important factor affecting shrimp aquaculture. Changes in water in shrimp ponds depend on the species and amount of plankton in the water. Single-cell algae in freshwater ponds reproduce more quickly. Special attention should be paid to changes in the water color in the shrimp ponds within 24 hours. If the water color changes too quickly within 24 hours, the transparency will be reduced. Adding new water to prevent the production tank from “turning water†causes dead shrimp.
The transparency of shrimp ponds should be maintained at 30-40 cm. If the transparency is too large, timely fertilization and the addition of fresh water are required to promote the rapid propagation of plankton. During the cultivation period, the inorganic fertilizer is generally applied about 7 days after the emergence, generally urea is used. The main 0.5 ~ 1.5kg/667m2, within one month after the release of the pool water to the highest level. The entire breeding period must be guaranteed every 10 to 15cm. The pool water is added to the maximum water level within one month after the seedlings are released. During the entire breeding period, 30% of the water should be changed every 10 days. An intensive culture pond with a water depth of more than 1m must be equipped with an aerator, and an impeller-type aerator is generally installed at 667m2 to 3300m2 to keep the oxygen in the upper and bottom layers of shrimp ponds above 4mg/L.
pH during the culture period should be maintained between 7.5 and 8.5. The pH value within one day should not exceed 0.5, otherwise it will easily lead to stress response. In the use of quicklime disinfection to measure the pH of the water in advance, such as higher should be used with caution, so as not to cause further increase in pH, resulting in shrimp hazards.
2.4.2 Feeding and management Less than half a month after the shrimp is under the pond, no feeding is generally performed. The shrimp mainly feed on plankton in the pond. After half a month, check the shrimp body length and stomach fullness and stomach content. If the shrimp body is 0.7cm in length and grows to 2cm or more after half a month, the stomach rate is more than 80%. The food in the stomach is zooplankton and it can continue to feed without bait. If the above requirements are met, shrimp feed No. 0 (fine-grained feed) should be fed uniformly along the edge of the pool. The amount of feed should be referenced to the Chinese Prawn Feeding List or fed on the instructions on the bait package. With the growth of prawns, shrimps are gradually fed with bait 1, 2, 3, and feed materials, and at the same time, the amount of feed is increased, and they can also be used to assist the feeding of miscellaneous fish, crushing shellfish, and Artemia. It is worth mentioning that due to the impact of shrimp virus disease in recent years, it is best not to use sea fish, shellfish and shellfish as bait to avoid infection. The amount of new shrimp on the knife at night is relatively strong, feeding should be carried out at night, the transparency of the pool water is too small, and can be fed in small amounts during the day. Feed 3 to 4 meals a day, at 17 o'clock in the morning and 21 o'clock in the morning, at 1 o'clock in the morning and at 5:00 in the morning, feed 2 to 3 feeding sites per day, and check the baits after feeding. If there are residual baits within 1.5-2h, it proves that the feeding amount is too much; if less than 1h the bait is completely eaten, the next feeding amount should be increased too much; if less than 1h bait is completely eaten, the next time Increase the amount of feeding. The feeding of South American white prawns should adhere to the principle of feeding less frequently, and the number of flashes should be no less than 4 times per day, and should be fed more in the evening and before dawn.
3 Disease Prevention and Control
Due to the great influence of shrimp disease in seawater in recent years, the adoption of sea shrimp in a light-fed manner has been adopted in order to avoid the impact of shrimp disease. However, it is not that seawater shrimp does not become infected when it is put into freshwater cultivation. It only changes the environment and cuts off the route of transmission of pathogens, which reduces the incidence of shrimp. If preventive disease prevention measures are not put in place, they can also cause disease and cause failure in breeding. Therefore, the prevention and treatment of the sea prawn breeding is equally important.
The prevention and control of common diseases: To adhere to the principle of prevention, half a month with 0.5mg / L of dichloro disinfectant or 1mg / L bleach Quanchiposa. Can also be used every month with quicklime 15kg/667m2 bubble into the emulsion Quanchiposa to kill bacteria. In combination with feeding, the bait 3h was fed continuously every month. Found that the amount of knife new shrimp black peony, jaundice and other bacterial symptoms should be fed with antibiotic baits, while the whole pool spilled 0.5mg/L containing dichloro disinfectants, even 3 ~ 5d. If there are a large number of ciliates attached to the shrimp body and cockroaches, the whole pool of ciliated clams will be used for the treatment of ciliate diseases. The dosage shall be based on the instructions on the medicine packaging. Or in the field according to the guidance of professional and technical personnel medication, can also be used copper sulfate 0.5 ~ 0.7mg / L Quanchiposa, combined with water change, the body of shrimp off the shrimp body. The transparency of the pool water is too small. There is too much water in the cells or the ground moss. You can use copper sulfate 0.5 ~ 0.7mg/L Quanchiposa, while changing the water. If the number of enemy fish in the pool increases, you can use the tea seed cake to kill, the amount of dry weight per m3 body of water 8 ~ 10g, when used, the first tea seed cake crushed, soaked in water for 24h, take the juice will spill pool.
Symptoms and hazards of shrimp virus disease: Shrimp first stop eating, slow action, bouncing and weak, warm swim on the surface of the water or the bottom of the pool does not move, and soon died. Shrimp body color tends to be slightly reddish or faded, but some diseased shrimps do not change their body color. The typical diseased shrimp has a white spot a few millimeters in diameter inside the shell, which is particularly clear on the cephalothorax and is visible to the naked eye. The sick shrimp head breastplate is separated from the underlying tissue and is easily peeled off. Usually 2 to 3 days after onset, a maximum of one week can cause a large number of shrimp deaths. There is currently no effective medical treatment for the disease. The main prevention measures are comprehensive measures. If the technicians are diagnosed with a serious viral disease, they should consider collecting shrimp to avoid causing large economic losses.
4 Collection
The harvest time of shrimp depends mainly on the growth status and market conditions of shrimp. Generally, it is cultured for 60 to 100 days, and the product specifications of up to 7 to 10 cm can be collected. Common catching methods are as follows.
4.1 Shrimp trapping nets (or caged meat) The net is usually released in the evening and the net is received the next morning. According to the demand of the next day, the number of offline networks of the day can be determined. This method can be used to supply the market in succession and achieve a balanced listing.
4.2 Discharging shrimp According to the habit of shrimps that have strong activity ability before and after dusk or dawn, in the evening, 5 to 6 o'clock or 4 to 5 o'clock in the evening, open the gate to collect water and collect the shrimp first. Slowly release the water first, then increase the water discharge after the water flow is formed. Use this method when dry ponds are needed. 4.3 Pull a flat pond at the bottom of the net, and use the nets to catch shrimp at the end of the evening or dawn. Generally, the net catch rate can reach 70%. No matter which method is used to collect shrimp, the net shrimp should be sold in full and cannot be returned to the pool. , otherwise it will cause a lot of losses.
Sea shrimp freshwater aquaculture technology
The sea is a method of raising fish by diluting the seawater shrimp into fresh water for cultivation. Due to the widespread epidemics of diseases in recent years, seawater shrimp farming has been severely affected. Due to the widespread prevalence of shrimp diseases in recent years, the marine shrimp farming industry has been severely affected. In order to explore new aquaculture models and methods, many provinces and cities have conducted new trials of freshwater aquaculture shrimp and Penaeus vannamei and have succeeded in finding a new way for the development of seawater shrimp farming. In the past two years, the city has also conducted freshwater aquaculture trials for new penaeus and Penaeus vannamei, and artificial breeding tests for new penholders. The results of this experiment have been gratifying, and the main points of breeding techniques have been summarized.
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