I. Biological characteristics of Penaeus vannamei
1, physiological, ecological characteristics
Penaeus vannamei is one of the three best shrimp species with the highest aquaculture production in the world today. The shrimp grows fast, has strong anti-environmental change ability, strong disease resistance, high processed meat rate, and delicious meat taste. It is currently a best-selling product in the international aquatic market. The main indicators of shrimp adaptation to the environment are:
(1) Water temperature:
Living water temperature: 6-40 °C
Growth water temperature: 15-38°C
Optimal growth water temperature: 22-35°C
The ability to adapt to low temperatures was somewhat poor, with less than 15°C feeding activity affected, and shrimp lying on the side below 9°C.
(2) Salinity:
It can grow in the water with a salinity of 0.5‰ to 35‰. After desalination, it can be cultured in pure fresh water and obtain high yield.
(3) Dissolved oxygen:
The demand for Macrobrachium rosenbergii is high, generally requiring more than 5 mg/l, with a minimum tolerance of 1.2 mg/l.
(4) Other physical and chemical factors:
pH7.0-8.5, ammonia nitrogen, nitrite nitrogen, etc. can not be too high.
(5) Growth:
In general, the water temperature is 22-35°C, and the fish is raised in fresh water for 60 days. The shrimp can generally be raised to about 12 centimeters, and a commercial shrimp with a body weight of about 15 grams, with a specification of 30-35 heads/kg. The average freshwater aquaculture survival rate is 60-70%, and the yield is 300-400 kg/mu.
(6) Feed:
Protein content of 25-30% can meet its nutritional needs, but the premix is ​​different from other freshwater crustaceans and fish. The shrimps have a mutual residual habit, and this behavior is more pronounced with the growth of shrimp, so the amount of feed is usually enough to feed.
(7) Diseases:
So far, no major diseases have been found in freshwater aquaculture, but with the growing scale of farming, disease problems may become the key to the success of the shrimp breeding in freshwater. Therefore, disease prevention is a problem that should be paid attention to in daily culture. one.
2. Analysis of the possibility and development trend of freshwater aquaculture
(1) Numerous successful examples of freshwater aquaculture have shown that the shrimp can be properly treated with the desalination technology when seedlings and seedlings are cultivated in ponds. At present, most of the pond aquaculture water in China can be cultured with this shrimp and obtain good economic benefits. .
(2) At present, freshwater aquaculture has little disease, and shrimp farming is one of the major constraints in marine aquaculture.
(3) At present, there are many factors such as fish, shrimp, crab, frog, and other species of freshwater aquaculture in China, comprehensive market prices, market demand, production investment, capital turnover, maturity of production technology, economic benefits, etc. Compared with Penaeus vannamei. Therefore, the freshwater aquaculture of the shrimp is bound to develop rapidly in recent years. To seize the opportunities and take the first step, the rewards obtained are self-evident.
(4) In coastal areas such as Yancheng, Nantong, Lianyungang, etc. in our province, fresh water itself has 1.4-5 inches.
The salinity is not suitable for breeding in this kind of water environment (the crab will be precocious, and the individual is not big), but it is the unique natural conditions for the breeding of white shrimp in South America, which is undoubtedly a good development for the rural economy in northern Jiangsu. Opportunity.
Second, several major factors affecting freshwater aquaculture
1, shrimp:
(1) Source and quality of broodstock:
Mass production practices have proved that the pros and cons of the parents are very important factors for the ability of aquaculture to produce high yields and stabilize production. Normally cultivated shrimp cannot be used as a parent, and the source of the parent should be a wild individual in the natural sea area.
(2) shrimp seedlings specifications:
White shrimps in South America are generally slender, and their size is generally between 0.6 and 0.7 centimeters. Feeding directly into freshwater is not stable. Therefore, suitable stocking specifications should be more than 1 cm, and some even use 2 cm seedlings. technology.
(3) The shrimp seedlings have good vigor, obvious swimming direction (no swimming circle), slender body section, uniform size, and clean body surface.
2, desalination processing:
(1) Seedlings
Penaeus vannamei seedlings salinity of 18-20, freshwater aquaculture seedlings, nursery field should be from the virus from the nourishment traces of stalks 勾 æš é›’ç¼ª 雒缪 smell ä»» ‰ ‰ ‰ ‰ ‰ ‰ 5 ‰ between.
(2) Pool water
Put a certain area around the corner of the pond with a colorful cloth, usually 500-1000 tails/square meter2, and the water depth is about 50 centimeters. Then use salt brine or coarse salt to adjust the water to a similar salinity to the seedling field. Difference in salinity 1 Hey. Then put the seedlings into holdings, natural desalination, 7-10 days after the removal of the multicolored cloth, normal breeding can be.
(3) Feed:
Feed quality is also one of the key factors affecting the growth and yield of Penaeus vannamei. Penaeus vannamei feeds are not the same as the current demand for freshwater aquaculture, especially on additives. The feed is not easy to produce: 1 shrimp is prone to disease 2 shrimp are not grown homogeneously 3 can eat each other and have a low survival rate. In 2000, the Freshwater Fisheries Research Center of the Chinese Academy of Fishery Sciences cooperated with Changshu Jiangnan Feed Factory to provide formulas, premixes (additives) and disease-preventive Chinese herbal medicines from the Freshwater Center. Jiangnan Feedstuffs Factory produced the “Zhongshui†brand special feed for South American white prawn, and the fishermen The breeding practice has achieved good results.
Introduce a self-made formula: 20% of imported fishmeal, 40% of soybean meal, 25% of wheat flour, 10% of sub-powder, 3% of bone meal, and 2% of special additive for white shrimp of South America (produced by Danshui Zhongshui Fishery and Pharmacy).
(4) Pond conditions:
1 There must be no aquatic weeds (white penaeus vannamei habits, and the swimming speed is faster. Excessive aquatic weeds in the pond affect the breeding effect).
2 The clear pond should be thorough and there must be no wild fish.
3 The sludge should not be too thick, and the sediment thickness should be kept within 10-15 cm. The bottom of the pool is flat.
4 Water depth 1-1.5 meters.
5 The best area is 5-20 acres.
Third, feeding and management
1, clear pond:
Clear the wild fish in the pond and other predators, generally available lime, bleaching powder and so on.
2, fertilizer water:
The fermented chickens, pig manure and other fertilizers (usually compost) are used to cultivate bait organisms such as red worms.
3, timely release seedlings:
The optimum growth temperature of Penaeus vannamei is 22-35°C. In this water temperature range, shrimp culture is used for rearing. The seedling grows fast, has a large food intake, has a strong physique, is strong in disease resistance, and has a high survival rate. In Jiangsu, it is generally on May 15. After the day, the seedlings can be planted until mid-July.
4, stocking density:
(1) Extensive:
Poorly equipped ponds usually have 1 to 15,000 tails per acre, and the output is about 200 pounds.
(2) Intensive care:
Put about 30,000 per acre and the output is about 400 pounds.
(3) High-density farming:
In addition to the need for an aerator, the drainage must be convenient, the pond requires a higher condition, 50,000 to 60,000 mu, and a yield of about 800 to 1,000 pounds.
5, pool water regulation:
The ideal water color is tan. In the early stage of cultivation, the transparency is controlled at about 30 centimeters and about 40 centimeters later. During the cultivation period, chickens, pigs and cow dung are chased once a week. The dosage is 5-7 kg/mu. The specific amount and frequency should be flexibly controlled according to the water color. It is recommended to use 10-15ppm photosynthetic bacteria or EM biologically active bacteria (provided by the freshwater center environmental protection room) once every 10 days, which can not only reduce the content of organic organisms in water, but also reduce the incidence rate and stabilize the pond conditions.
6. Feeding:
(1) The feed is best used for the special feed of Penaeus vannamei, with a preliminary particle size of 0.05-0.5 cm, medium-term 0.5-1.5 cm, and late 1.5-2.0 cm particles. Or use homemade feed, but processing should pay attention to three points: 1 additives; 2 smash fineness 80 mesh or more; 3 freshness and particle size.
(2) Feeding amount:
Early period (1-3cm): 8-10%;
Mid-term (3-8 cm): 6-8%;
Late (more than 8 cm): 4-5%.
(3) Feeding times:
The second period of breeding: 8 o'clock, 19 o'clock.
Three mid-cultivation periods: 8 o'clock, 19 o'clock, 23 o'clock.
The fourth period of rearing: 7 o'clock, 12 o'clock, 19 o'clock, 24 o'clock.
The amount of feed in the evening accounted for 50% of the daily feed, such as mid-term, 80%, 20%, 19:30%, and 23:50%. The feeding method is to spread evenly along the edge of the pool. The pond area is large, and a line needs to be fed in the middle.
7, patrol pond:
Take a morning or evening tour to observe changes in water color and whether the shrimp floats. In the evening, check the shrimp activity, growth status, eating conditions, etc. by means of light observation or net fishing during the day.
8, shrimp disease prevention and control:
Once this shrimp is attacked, it is generally very difficult to treat. It is usually based on prevention. The main methods are as follows: (1) Prophylactic drugs should be added to the feed (China Water Brand P. vannamei special material has this effect); 2) Disinfectant is used once a week. It is 0.5ppm.
9, listing specifications and harvest time:
The market specification is 30-35/kg, and the breeding cycle is 60-65 days. Temperatures below 8°C cannot collect shrimp.
IV. Preliminary Analysis of Economic Benefits Based on our own breeding experience, we analyzed the situation of aquaculture in all parts of the country, especially in Shanghai, Zhejiang, and Jiangsu.
1, extensive care: put 1-15 million seedlings, yield 200 kg.
(1) Expenditure:
Miao: 1,000 yuan;
Feed: 700 yuan;
Rent pool: about 300 yuan;
Water treatment: 200 yuan;
Other costs: 300 yuan.
Subtotal: 2,500 yuan.
(2) Income: 200 kg? 28 yuan/kg = 5600 yuan.
(3) Mu profit: 3100 yuan (60-65 days).
2, intensive care: put 30,000 seedlings, yield 400 pounds.
(1) Expenditure:
Miao: 2000 yuan;
Feed: 1,400 yuan;
Rent pool: 300 yuan;
Water treatment: 200 yuan;
Other expenses: 300 yuan.
Subtotal: 4200 yuan.
(2) Income: 400 pounds, 28 yuan/kilogram = 1,1200 yuan.
(3) Mu profit: 7,000 yuan.
From the above results, it can be generally seen that the economic benefits of South American white shrimp aquaculture are very optimistic. Even if the market price drops to 20 yuan/kg, it can also obtain a profit of over 2,000 yuan. And, raising two seasons of shrimp each year has proved to be feasible both in theory and in production practice.
1, physiological, ecological characteristics
Penaeus vannamei is one of the three best shrimp species with the highest aquaculture production in the world today. The shrimp grows fast, has strong anti-environmental change ability, strong disease resistance, high processed meat rate, and delicious meat taste. It is currently a best-selling product in the international aquatic market. The main indicators of shrimp adaptation to the environment are:
(1) Water temperature:
Living water temperature: 6-40 °C
Growth water temperature: 15-38°C
Optimal growth water temperature: 22-35°C
The ability to adapt to low temperatures was somewhat poor, with less than 15°C feeding activity affected, and shrimp lying on the side below 9°C.
(2) Salinity:
It can grow in the water with a salinity of 0.5‰ to 35‰. After desalination, it can be cultured in pure fresh water and obtain high yield.
(3) Dissolved oxygen:
The demand for Macrobrachium rosenbergii is high, generally requiring more than 5 mg/l, with a minimum tolerance of 1.2 mg/l.
(4) Other physical and chemical factors:
pH7.0-8.5, ammonia nitrogen, nitrite nitrogen, etc. can not be too high.
(5) Growth:
In general, the water temperature is 22-35°C, and the fish is raised in fresh water for 60 days. The shrimp can generally be raised to about 12 centimeters, and a commercial shrimp with a body weight of about 15 grams, with a specification of 30-35 heads/kg. The average freshwater aquaculture survival rate is 60-70%, and the yield is 300-400 kg/mu.
(6) Feed:
Protein content of 25-30% can meet its nutritional needs, but the premix is ​​different from other freshwater crustaceans and fish. The shrimps have a mutual residual habit, and this behavior is more pronounced with the growth of shrimp, so the amount of feed is usually enough to feed.
(7) Diseases:
So far, no major diseases have been found in freshwater aquaculture, but with the growing scale of farming, disease problems may become the key to the success of the shrimp breeding in freshwater. Therefore, disease prevention is a problem that should be paid attention to in daily culture. one.
2. Analysis of the possibility and development trend of freshwater aquaculture
(1) Numerous successful examples of freshwater aquaculture have shown that the shrimp can be properly treated with the desalination technology when seedlings and seedlings are cultivated in ponds. At present, most of the pond aquaculture water in China can be cultured with this shrimp and obtain good economic benefits. .
(2) At present, freshwater aquaculture has little disease, and shrimp farming is one of the major constraints in marine aquaculture.
(3) At present, there are many factors such as fish, shrimp, crab, frog, and other species of freshwater aquaculture in China, comprehensive market prices, market demand, production investment, capital turnover, maturity of production technology, economic benefits, etc. Compared with Penaeus vannamei. Therefore, the freshwater aquaculture of the shrimp is bound to develop rapidly in recent years. To seize the opportunities and take the first step, the rewards obtained are self-evident.
(4) In coastal areas such as Yancheng, Nantong, Lianyungang, etc. in our province, fresh water itself has 1.4-5 inches.
The salinity is not suitable for breeding in this kind of water environment (the crab will be precocious, and the individual is not big), but it is the unique natural conditions for the breeding of white shrimp in South America, which is undoubtedly a good development for the rural economy in northern Jiangsu. Opportunity.
Second, several major factors affecting freshwater aquaculture
1, shrimp:
(1) Source and quality of broodstock:
Mass production practices have proved that the pros and cons of the parents are very important factors for the ability of aquaculture to produce high yields and stabilize production. Normally cultivated shrimp cannot be used as a parent, and the source of the parent should be a wild individual in the natural sea area.
(2) shrimp seedlings specifications:
White shrimps in South America are generally slender, and their size is generally between 0.6 and 0.7 centimeters. Feeding directly into freshwater is not stable. Therefore, suitable stocking specifications should be more than 1 cm, and some even use 2 cm seedlings. technology.
(3) The shrimp seedlings have good vigor, obvious swimming direction (no swimming circle), slender body section, uniform size, and clean body surface.
2, desalination processing:
(1) Seedlings
Penaeus vannamei seedlings salinity of 18-20, freshwater aquaculture seedlings, nursery field should be from the virus from the nourishment traces of stalks 勾 æš é›’ç¼ª 雒缪 smell ä»» ‰ ‰ ‰ ‰ ‰ ‰ 5 ‰ between.
(2) Pool water
Put a certain area around the corner of the pond with a colorful cloth, usually 500-1000 tails/square meter2, and the water depth is about 50 centimeters. Then use salt brine or coarse salt to adjust the water to a similar salinity to the seedling field. Difference in salinity 1 Hey. Then put the seedlings into holdings, natural desalination, 7-10 days after the removal of the multicolored cloth, normal breeding can be.
(3) Feed:
Feed quality is also one of the key factors affecting the growth and yield of Penaeus vannamei. Penaeus vannamei feeds are not the same as the current demand for freshwater aquaculture, especially on additives. The feed is not easy to produce: 1 shrimp is prone to disease 2 shrimp are not grown homogeneously 3 can eat each other and have a low survival rate. In 2000, the Freshwater Fisheries Research Center of the Chinese Academy of Fishery Sciences cooperated with Changshu Jiangnan Feed Factory to provide formulas, premixes (additives) and disease-preventive Chinese herbal medicines from the Freshwater Center. Jiangnan Feedstuffs Factory produced the “Zhongshui†brand special feed for South American white prawn, and the fishermen The breeding practice has achieved good results.
Introduce a self-made formula: 20% of imported fishmeal, 40% of soybean meal, 25% of wheat flour, 10% of sub-powder, 3% of bone meal, and 2% of special additive for white shrimp of South America (produced by Danshui Zhongshui Fishery and Pharmacy).
(4) Pond conditions:
1 There must be no aquatic weeds (white penaeus vannamei habits, and the swimming speed is faster. Excessive aquatic weeds in the pond affect the breeding effect).
2 The clear pond should be thorough and there must be no wild fish.
3 The sludge should not be too thick, and the sediment thickness should be kept within 10-15 cm. The bottom of the pool is flat.
4 Water depth 1-1.5 meters.
5 The best area is 5-20 acres.
Third, feeding and management
1, clear pond:
Clear the wild fish in the pond and other predators, generally available lime, bleaching powder and so on.
2, fertilizer water:
The fermented chickens, pig manure and other fertilizers (usually compost) are used to cultivate bait organisms such as red worms.
3, timely release seedlings:
The optimum growth temperature of Penaeus vannamei is 22-35°C. In this water temperature range, shrimp culture is used for rearing. The seedling grows fast, has a large food intake, has a strong physique, is strong in disease resistance, and has a high survival rate. In Jiangsu, it is generally on May 15. After the day, the seedlings can be planted until mid-July.
4, stocking density:
(1) Extensive:
Poorly equipped ponds usually have 1 to 15,000 tails per acre, and the output is about 200 pounds.
(2) Intensive care:
Put about 30,000 per acre and the output is about 400 pounds.
(3) High-density farming:
In addition to the need for an aerator, the drainage must be convenient, the pond requires a higher condition, 50,000 to 60,000 mu, and a yield of about 800 to 1,000 pounds.
5, pool water regulation:
The ideal water color is tan. In the early stage of cultivation, the transparency is controlled at about 30 centimeters and about 40 centimeters later. During the cultivation period, chickens, pigs and cow dung are chased once a week. The dosage is 5-7 kg/mu. The specific amount and frequency should be flexibly controlled according to the water color. It is recommended to use 10-15ppm photosynthetic bacteria or EM biologically active bacteria (provided by the freshwater center environmental protection room) once every 10 days, which can not only reduce the content of organic organisms in water, but also reduce the incidence rate and stabilize the pond conditions.
6. Feeding:
(1) The feed is best used for the special feed of Penaeus vannamei, with a preliminary particle size of 0.05-0.5 cm, medium-term 0.5-1.5 cm, and late 1.5-2.0 cm particles. Or use homemade feed, but processing should pay attention to three points: 1 additives; 2 smash fineness 80 mesh or more; 3 freshness and particle size.
(2) Feeding amount:
Early period (1-3cm): 8-10%;
Mid-term (3-8 cm): 6-8%;
Late (more than 8 cm): 4-5%.
(3) Feeding times:
The second period of breeding: 8 o'clock, 19 o'clock.
Three mid-cultivation periods: 8 o'clock, 19 o'clock, 23 o'clock.
The fourth period of rearing: 7 o'clock, 12 o'clock, 19 o'clock, 24 o'clock.
The amount of feed in the evening accounted for 50% of the daily feed, such as mid-term, 80%, 20%, 19:30%, and 23:50%. The feeding method is to spread evenly along the edge of the pool. The pond area is large, and a line needs to be fed in the middle.
7, patrol pond:
Take a morning or evening tour to observe changes in water color and whether the shrimp floats. In the evening, check the shrimp activity, growth status, eating conditions, etc. by means of light observation or net fishing during the day.
8, shrimp disease prevention and control:
Once this shrimp is attacked, it is generally very difficult to treat. It is usually based on prevention. The main methods are as follows: (1) Prophylactic drugs should be added to the feed (China Water Brand P. vannamei special material has this effect); 2) Disinfectant is used once a week. It is 0.5ppm.
9, listing specifications and harvest time:
The market specification is 30-35/kg, and the breeding cycle is 60-65 days. Temperatures below 8°C cannot collect shrimp.
IV. Preliminary Analysis of Economic Benefits Based on our own breeding experience, we analyzed the situation of aquaculture in all parts of the country, especially in Shanghai, Zhejiang, and Jiangsu.
1, extensive care: put 1-15 million seedlings, yield 200 kg.
(1) Expenditure:
Miao: 1,000 yuan;
Feed: 700 yuan;
Rent pool: about 300 yuan;
Water treatment: 200 yuan;
Other costs: 300 yuan.
Subtotal: 2,500 yuan.
(2) Income: 200 kg? 28 yuan/kg = 5600 yuan.
(3) Mu profit: 3100 yuan (60-65 days).
2, intensive care: put 30,000 seedlings, yield 400 pounds.
(1) Expenditure:
Miao: 2000 yuan;
Feed: 1,400 yuan;
Rent pool: 300 yuan;
Water treatment: 200 yuan;
Other expenses: 300 yuan.
Subtotal: 4200 yuan.
(2) Income: 400 pounds, 28 yuan/kilogram = 1,1200 yuan.
(3) Mu profit: 7,000 yuan.
From the above results, it can be generally seen that the economic benefits of South American white shrimp aquaculture are very optimistic. Even if the market price drops to 20 yuan/kg, it can also obtain a profit of over 2,000 yuan. And, raising two seasons of shrimp each year has proved to be feasible both in theory and in production practice.