A Comprehensive Guide to Whiteleg Shrimp Farming Methods and Techniques

AbstractSite: abundant water source with good water quality, equipped with generators and aeration machinery. Preparation: first level the pond and remove silt, then disinfect and sterilize; install filter screens at the water inlet and cultivate bait organisms in the pond. Shrimp fry: select improved-variety shrimp fry, carry out a fry test before stocking, with 40,000-60,000 fry per mu being suitable. Feeding: different growth stages have slightly different food requirements. Water quality: adjust the pH value, pay attention to dissolved oxygen in the pond, and do a good job of water quality measurement. Disease prevention: actively prevent common shrimp diseases. Harvest: they can be harvested once they reach 120 shrimp/kg.

At present, market demand for whiteleg shrimp is growing, and whiteleg shrimp is also a type of aquaculture project that aquaculture farmers have favored in recent years, because whiteleg shrimp has advantages such as wide adaptability, strong disease resistance, rapid growth, low requirements for feed protein content, high meat yield and long survival time out of water. Although it has many advantages, it is still necessary to fully master its farming techniques in order to bring higher yields and returns.

I. Basic Conditions

1. Site requirements. It is advisable to choose a place with abundant water sources, good water quality, convenient drainage and irrigation, convenient transportation, mature and complete power supply, and no pollution sources within a 3-5 km range.

2. Pond requirements. The shrimp pond area should be 5-10 mu, rectangular in shape, oriented east-west, with a water depth of about 2 m, a flat pond bottom, an embankment width of no less than 2 m, and inlet and drainage channels at both ends of the pond.

3. Machinery configuration. Aquaculture ponds must be equipped with generators and aeration machinery. The aeration machine power generally required per mu of pond is about 1 kilowatt, that is, each pond should be equipped with 2-5 aerators of 1.5 kilowatts or 3 kilowatts. The matched aerators are best used in combination with impeller type, paddlewheel type or nano-tube bottom aeration.

II. Preliminary Preparation

1. Level the pond and remove silt. In winter, remove weeds and excessive silt from the pond bottom, repair the pond, and expose the pond bottom to the sun so that it dries and cracks.

2. Disinfection and sterilization. About one month before stocking the fry, use 100-150 kg of quicklime or 15-20 kg of bleaching powder or 50 kg of tea seed cake per mu for pond clearing and disinfection to kill pathogens, fish eggs, etc. Among pond-clearing drugs, quicklime is especially preferred.

3. Filling the shrimp pond with water. Water can be added after the effect of the pond-clearing drug has disappeared and about 10 days before stocking. However, before filling the shrimp pond with water, first observe whether filamentous algae have appeared in the pond. If so, first add water to the pond to a depth of about 10 cm, then splash Qingtaijing evenly over the whole pond to kill the filamentous algae. After this treatment, a better water-fertilizing effect can be achieved. When filling with water, the following must also be done well: install a filter screen at the water inlet. The filter screen is suitably made of 60-mesh polyamide mesh cloth or nylon sieve silk made into a straight cylindrical net piece, with a net length of more than 2 m, depending specifically on the size of the water inlet pump diameter. Control the water filling level. The first water filling is suitably 40-50 cm to facilitate fertilization and cultivation of bait organisms, and afterward gradually raise the water level, reaching about 80-100 cm at the time of stocking.

4. Cultivate bait organisms. Cultivating and propagating bait organisms (basic bait) in the shrimp pond is an effective measure to provide suitable bait after the shrimp fry enter the pond and to accelerate shrimp growth. It is one of the effective ways to make full use of the pond's natural productivity and reduce shrimp farming costs, so everyone must pay attention to it. Because basic bait organisms have the advantages of fast reproduction, simple and feasible culture methods and obvious nutritional effects, they have become an indispensable production link in the farming procedure. Practice shows that if the basic bait is abundant, the shrimp fry have a high survival rate and grow quickly after entering the pond. The methods for fertilizing shrimp pond water are:

Using organic fertilizer to fertilize water: the organic fertilizer used must be fully fermented. The amount used depends on the pond bottom environmental conditions, generally about 25 kg per mu, with the specific amount depending on how fertile the pond is, but before use it is best to mix it with lime for insect killing and disinfection to avoid pests. Carbon ammonia and phosphate fertilizer to fertilize water: the amount used is about 20 kg, and the ratio of carbon ammonia to phosphate fertilizer is 3:1. Compounded organic fertilizer to fertilize water: such as Jikai whiteleg shrimp special organic fertilizer, with an amount of 20-40 kg per mu. Used in combination with compound fertilizer, the effect will be better and faster. Other types: such as some biological fertilizers and active water-fertilizing agents sold on the market. Note: generally speaking, organic fertilizer, chemical fertilizer and biological fertilizer used in combination give the best effect. The specific amount should be determined according to the basic conditions of the pond, how fertile it is, and the water source and water quality. Generally after fertilizing the water, the water color should be yellow-green or tea-brown, with a transparency of 30-40 cm being good.

III. Shrimp Fry Stocking

1. Shrimp fry selection. Improved-variety and healthy shrimp fry: choose first-generation or second-generation fry, do not choose seedlings of degraded quality, and especially choose SPF fry. During the nursery process, there must have been no disease outbreaks and no stress reactions, that is, no dead fry have ever appeared, and the selected shrimp fry are required to be healthy fry with good vitality, strong physique, complete appendages, clean body surface and appendages, normal body shape, uniform size, and full and clear gastrointestinal tracts. Size: generally choose shrimp fry about 1 cm in size. Salinity: required to be below 3‰ and basically close to that of the stocking pond.

2. Fry test. Before stocking, a fry test must be carried out first. First put the aquaculture pond water into a fry test basin, then filter off the water from the selected desalinated fry and put them in, and observe for more than 12 hours. If no dead fry appear, the fry can be stocked; if dead fry appear, then investigate the cause from several aspects such as the salinity, pH value, ammonia nitrogen and nitrite of the pond water body.

3. Stocking time. Choose a water temperature preferably above 23°C. The suitable time for stocking fry is from early May to early June.

4. Stocking density. Generally, 40,000-60,000 fry per mu is suitable. Stocking should be carried out on a clear morning or evening, not at noon under direct sunlight or in rainy weather.

5. Water quality requirements. Water color: yellow-green or tea-brown is preferred; transparency: about 30-40 cm; pH value: between 7.8-9; salinity: the salinity of the pond should be basically close to that in the nursery pond; water temperature: the temperature difference must not exceed 2°C. If the difference is large, try to adjust it. Generally, after the shrimp fry arrive at the shrimp pond, place the fry bags in the shrimp pond for 10-15 minutes, and after the water temperature has equalized, open the shrimp fry bags and put them into the pond. This helps increase the survival rate of the shrimp fry.

IV. Feeding Techniques

1. Feed selection. Choose pollution-free whiteleg shrimp feed.

2. Feed requirements. Whiteleg shrimp have slightly different food requirements at different growth stages. Generally speaking, in the juvenile shrimp stage within 6 cm, the requirements for protein and unsaturated fatty acids are relatively high, and the protein content in the feed should reach 38% or more; in the middle shrimp stage of 6-10 cm, protein and unsaturated fatty acids can be correspondingly reduced, and the protein content can be between 36-38%; in the adult shrimp stage above 10 cm, generally a protein content of 32-36% is sufficient.

3. Control of feeding amount. The feeding amount should be determined according to specific conditions such as weather, survival rate, stock in the pond and residual feed. Within half a month after the shrimp fry are put into the pond, a small amount of whiteleg shrimp opening feed or crushed feed can be fed; juvenile shrimp stage: feed No. 1 feed, with a protein content of 38% or more, and the time for finishing the feed should be controlled at 2-3 hours; middle shrimp stage: feed No. 2 feed, with a protein content between 36-38%, and the time for finishing the feed should be controlled at 1-2 hours; adult shrimp stage: feed No. 3 feed, with a protein content of 32-36%, and the time for finishing the feed should be controlled at about 1 hour.

4. Feeding techniques. Adhere to frequent feeding in small amounts, with the number of feedings per day generally no less than 2. If divided into two feedings, the feeding times are: 5-8 a.m. and 4-6 p.m.; feed less or stop feeding when the water temperature is below 15°C or above 32°C; feed more when it is mild and sunny, and feed less or stop feeding during thunderstorms, storms, and cold current invasions (temperature drop of more than 5°C); feed less on the day when shrimp molt in large numbers, and feed more 1 day after molting; feed more when water quality is good, and feed less or stop feeding when water quality deteriorates.

V. Water Quality Management

The quality of the shrimp pond water environment directly affects the growth and survival of whiteleg shrimp; shrimp farming is water management. If water quality can be effectively managed so that the shrimp's living environment is good, then the shrimp will be healthy and grow rapidly. If water environment pollutants exceed the shrimp's tolerance, in mild cases they will cause poor growth and chronic poisoning, as well as reduce physiological functions, induce disease, cause abnormal activity behavior, and cause death by poisoning. Therefore, water quality management occupies a very important position in shrimp farming. The quality of water is affected by water source, climate, aquatic organisms, residual feed and biological excreta. These effects sometimes act not only singly but also through combined interaction, so each influencing factor must be noted and controlled to keep the water quality stable and good and promote healthy growth of the shrimp. Specifically do the following well:

1. Control water color well: the ideal water color for whiteleg shrimp farming is yellow-green or tea-brown. In the early stage of farming, transparency should be controlled between 30-40 cm, and in the middle and late stages controlled at about 30 cm. According to how fertile the water is, add new water once every 7-10 days. It is best to use a microbial preparation once every 10-15 days to improve water quality, reduce the organic biological content in the water body, and lower ammonia nitrogen, nitrite content and organic matter oxygen consumption.

2. Adjust the pH value well: the most suitable pH value for whiteleg shrimp is 7.8-8.6. If it is too low, use quicklime for adjustment; it is best not to exceed 9.0.

3. Improve the bottom substrate well: as the shrimp grow and feed increases, especially when whiteleg shrimp farming reaches the middle and late stages, the bottom environment is relatively poor, so substrate improvement is needed. If the water is too dense or too clear, the bottom environment is often poor, and some substrate improver needs to be applied to improve the bottom environment, so as to reduce adverse effects on whiteleg shrimp.

4. Pay attention to dissolved oxygen in the pond: during the farming process of whiteleg shrimp, as the shrimp grow, the demand for dissolved oxygen in the water also increases. Therefore, in the early stage of farming, according to water quality conditions, turn on the aerator intermittently. Afterward, as the shrimp grow, the operating time should be gradually extended to ensure that the dissolved oxygen in the pond is above 5 mg/L and the dissolved oxygen at the pond bottom is above 3 mg/L. When necessary, apply bottom oxygenation agents to increase the dissolved oxygen in the entire pond water body.

5. Turn on the aerator at appropriate times: within one month of stocking the fry, usually turn it on for 2-3 hours on rainy days and when adding water, which can better cultivate good water quality; after one month, turn it on for 2-4 hours at noon on sunny days and at night each day, and gradually extend the operating time as the shrimp grow. On rainy days and in weather with poor water quality, the operating time should be extended or the machine should be run 24 hours, which helps maintain stable and good water quality and prevent whiteleg shrimp from oxygen deficiency and floating head.

6. Do a good job of water quality measurement: the main measurement indicators are pH value, dissolved oxygen, ammonia nitrogen, nitrite and transparency. Once a problem occurs with any one indicator, effective measures should be taken promptly.

VI. Disease Prevention Techniques

The occurrence of diseases in whiteleg shrimp is very complex. On the basis of doing a good job of pond silt removal and disinfection, stocking healthy shrimp fry, and reasonably feeding high-quality feed, the following measures should also be taken:

1. Enhance stress resistance. Splash “Yingji Wang” over the pond and add shrimp multivitamins, “Jianlisu”, etc. to the feed to enhance the stress resistance and disease resistance of whiteleg shrimp.

2. Solve insufficient dissolved oxygen in the pond. Turn on aerators, apply oxygen-increasing agents, etc., to increase dissolved oxygen in the upper and lower water layers and prevent whiteleg shrimp from floating head or hidden floating head.

3. Improve pond environmental conditions. Use biological preparations and substrate improvers, etc., to improve pond water quality and bottom environment and maintain the balance of algae and bacteria.

4. Conduct regular water quality tests to keep water quality in good condition.

5. Carry out drug prevention. Water body disinfection generally uses dibromohydantoin, chlorine dioxide, povidone iodine, etc.; oral drugs generally use drugs with stress-resistance ability, such as shrimp multivitamins, splashed vitamin C, immune polysaccharides and other drugs.

6. Diseased shrimp and dead shrimp found should be promptly removed, the cause of disease and death immediately checked, and appropriate medicine given according to the symptoms, or other effective measures taken.

VII. Harvest

1. Do the preparatory work well. After more than 90 days of farming, they can be harvested when the size reaches about 120 shrimp/kg. Before harvesting, all preparatory work for shrimp harvesting should be done in advance. Conduct market research, understand the market for shrimp sales, and contact sales channels; learn from the local meteorological department about recent weather conditions, temperature changes, etc.; carefully and comprehensively check the growth status of the shrimp in the shrimp pond and the carrying capacity of the organisms in the aquaculture water body; prepare shrimp harvesting tools.

2. Fishing. The fishing methods for whiteleg shrimp include placing ground cages for trapping, seine netting and draining the pond for harvesting, but note that: when whiteleg shrimp reach commercial size, harvest shrimp in stages and batches in a timely manner, implementing harvest the large and leave the small; before a typhoon arrives, according to the size of the shrimp, it is best to carry out one round of harvesting to reduce the shrimp load in the pond; when a cold current invades and the temperature suddenly drops (by more than 8°C), shrimp must not be harvested; when water quality suddenly deteriorates or abnormal phenomena appear in the shrimp, harvest shrimp as early as possible.