1. 1 pool selection
The pool should be built in an area with flat terrain, less silt, sufficient water, good water quality, no pollution and convenient water intake and drainage. It is suggested to use sediment with an area of 5 ~ 8 mu and a water depth of 2m, and each pond should be equipped with 2 ~ 3 2.2kW aerators. Mud and weeds in the old pond should be removed or ploughed and exposed at the bottom of the pond.
1.2 pond cleaning and disinfection
Water of 15 ~ 20 cm is poured into the pond 20 days before the seedlings are released, and the whole pond is sprayed with pond cleaning agent to kill harmful microorganisms. In some newly dug ponds and some aging ponds with poor water exchange capacity, in order to prevent the explosive propagation of harmful algae in the middle and late stage of culture, attention should be paid to using algae removal drugs in advance, such as algae killing drugs and grass-catching drugs, to kill harmful algae at the bottom of the pond.
1.3 inlet water purification and salinity adjustment.
After cleaning and disinfection, the shrimp pond is filled with water. When receiving water, use a 60-80 mesh filter to prevent harmful organisms from entering. After the water enters 80- 100 cm, it is necessary to disinfect the water body and kill the virus in the water body with powerful drugs such as bacterial toxins. At the same time, the pond was disinfected with a sprayer, and the drug concentration was appropriately increased. The salinity of the pond should be consistent with the desalted salinity of shrimp seedlings in the nursery.
1.4 flying water
The use of shrimp has a comprehensive effect. Once the shrimp is put into the pond, diatoms will be cultivated in 2 ~ 3 days. After the basic biological bait is cultivated, the seedlings are released after the water quality meets the following requirements.
1.4. 1 Visually, the color of the pool water has changed to yellow-brown or brown, yellow-green, and the transparency is about 25cm.
1.4.2 The instrument uses a microscope to observe the microbial density, uses a water quality analysis box to detect various water quality indicators, and releases the seedlings after meeting the requirements.
.5 Set aerator.
The impeller aerator has the best effect and is located in the deep water of the pool. Within one month after sowing, seedlings should be planted 1 time every day at noon and before dawn, each time for 2 ~ 3 hours. After one month, it will be turned on at noon and before dawn every day, 3 hours at noon and 10 hours before dawn. Increase startup time and frequency in rainy days. It should be turned on for at least 20 hours in the late breeding period.
2 shrimps
2. 1 Selection of shrimp fry
2. 1. 1 Principles to be mastered in purchasing grass shrimp seedlings
① Choose healthy shrimp seedlings (HHS) or shrimp seedlings that have been monitored by the shrimp disease detection center and are virus-free.
② There are no seedlings cultivated by high temperature and abuse of antibiotics.
2. 1.2 Shrimp seedlings should be uniform. The same batch of shrimp seedlings should be 1.0 ~ 1.2 cm in length, with clean body surface and strong vitality, and those with slender abdominal nodes are good seedlings.
2. 1.3 The two small antennae at the front end of healthy shrimps are close together, occasionally separated, but can be closed immediately. What can't be closed are poor shrimp seedlings. The tail fan of healthy shrimps is open.
2. 1.4 Healthy shrimps have "adherence behavior". If the shrimp is scooped up with a spoon, the strong shrimp will quickly swim to the side of the spoon and cling to the wall of the spoon. If you swim in the water, it is unhealthy shrimp seedlings.
2. 1.5 Take out several shrimps with a body length of about 1cm from the nursery pond, embed them with wet towels for 5 minutes, and put them back into the raw water after taking out, which has no influence on the survival rate and is a high-quality shrimp.
2.2 Stocking of shrimp fry
2.2. 1 Before releasing the seedlings, the water body must be disinfected to ensure that the water environment of the shrimp seedlings in the nursery and the water environment of the aquaculture pond are within a safe range. In addition, pay attention to the water test before stocking. After 1 ~ 2 days of water testing, shrimp seedlings can be released in batches without affecting the survival rate in the pond water environment.
2.2.2 Precautions for seedling release: ① The seedling release place should be on the windward side of the shrimp pond, and it is forbidden to release seedlings in windward or shallow water. (2) Don't put the seedlings in bad weather. Seedlings should be planted at 8-9 am or at sunset in the afternoon on sunny days, not at noon. (3) Don't rush to plant seedlings until the pond is cleaned. ④ Don't put seedlings in shrimp ponds with bad water color and poor water quality.
2.3 stocking density
The seedling density should be between 8 000 ~ 12 000 plants/mu, and the number of seedlings can be increased or decreased according to the actual situation due to different pond conditions.
3 Cultivation period management
"Raising shrimp is raising water" has become an experience. Maintain excellent water quality, so as to facilitate shrimp feeding and promote shrimp molting growth.
3. 1 water quality
The best range of water quality in grass shrimp culture pond is shown in the table below.
Bad adaptation range of measurement items
The PH value of 8 ~ 9 is lower than 7.5 or higher than 9.5.
Dissolved oxygen (7 ~10) ×10-63×10-6 or lower than 12× 10-6.
Salinity is lower than 0.0 15 ~ 0.025 0.0 10 or higher than 0.035.
Nonionic ammonia (NH3-n) (0.1~ 0.5) ×10-60.6×10-6 or more.
Phosphate (PO4-P) (0.2 ~ 0.4) ×10-6 0.6×10-6 or more.
Hydrogen sulfide (0 ~ 0.2) ×10-60.6×10-6 or more.
Nitrite (0.01~ 0.05) ×10-6 0.06×10-6 or more.
3.2 change water
Exchange water should follow the following principles:
① Change less during the day and more at night.
② There are fewer sunny days and more cloudy days.
③ Change less when there is wind, and change more when there is no wind.
(4) There are few changes in large pools and many changes in small pools.
⑤ Change the density less and change the density more.
6. If the biomass is too high and changes more or less,
⑦ If the water color is too strong and the transparency is less than 20cm, change more.
When the water temperature is lower than 20℃, the change is small, and when the water temperature is higher than 32℃, the change is great.
Pet-name ruby fishy smell of water should be completely replaced. If it can't be replaced, we should use "water quality improvement essence" and "fish and shrimp pond bottom cleaning" for comprehensive management.
Attending to add water, water should be drained before irrigation. Attention should be paid to the adsorption of chromium heavy metal poisons in ponds using well water.
3.3 Water color control and management during aquaculture
3.3. 1 water color The so-called water color refers to the color of the pool water in the sun. The water color in the breeding period can be summarized as follows:
① The reddish-brown water mainly contains diatoms. It is the best water color for shrimp culture.
② Light green and emerald green water mainly contains green algae. Green algae can absorb a lot of nitrogen fertilizer in the water and purify the water, so prawns grow rapidly in green water. This water color is also the desired water color in aquaculture.
③ Dark green water mainly contains blue-green algae. Ponds are prone to aging. In this kind of water, prawns can still survive, but the incidence rate is high.
④ Dark brown and soy sauce water mainly contains flagellates. It is easy to occur in aging ponds with improper feeding and deteriorated bottom material. Some flagellates can secrete paralytic neurotoxins, leading to shrimp poisoning and death. The abnormal management of this aquatic genus is mainly due to the excessive feeding of inferior bait and the increase of residual bait, which leads to the increase of dissolved and suspended organic matter and the proliferation of brown algae.
⑤ Yellow water mainly contains dinoflagellate. This water color is not suitable for shrimp and fish farming, but it is suitable for the growth of shellfish. Change the water immediately, increase the dissolved oxygen, and at least turn the water yellow and green.
⑥ White turbid water: It mainly contains zooplankton or organic debris such as ciliates and clay particles. This water color is easy to make prawns sick, so pay attention to changing the water color.
⑦ The yellow and turbid white water is caused by the rain scouring the fine mud on the dike and entering the pond, which is not suitable for shrimp culture.
(8) The clarified colored water lacks nutrients or is polluted by heavy metals, and there is no phytoplankton, which is not conducive to shrimp culture.
3.3.2 Measures to change the color of water
(1) Increase the displacement and add the sterilized water.
(2) Using shrimp or marine plant auxin to forcibly propagate beneficial algae and change the water color.
(3) Kill algae with Xiaduling or Yuzaowang, and then apply fertilizer after the expiration date.
④ Use prebiotic drug "Fish and Shrimp Savior" to improve the bottom of the pond.
3.4 feeding
3.4. 1 The feeding amount should be accurately and reasonably fed according to the physiological needs of prawns at each growth stage and the living conditions at that time. The daily feeding amount of grass shrimp (compound feed) is generally calculated according to the weight of each tail. 1g body weight, feed intake 16%, 2g body weight 14%, 3g body weight 12%, 5g body weight 10%, 8g body weight 8%, 15 ~ 20g body weight 6% ~ 20g.
3.4.2 Feeding principles According to the living habits of grass shrimp, the following principles should be mastered when feeding.
(1) Daily feeding should be more and less, and even.
② Feed more at night and less during the day. The feeding amount at night accounts for 65% of the total feeding amount, and the feeding amount at day accounts for 35%.
③ Throw less when the weather is bad, and cast more when the weather is good.
(4) When the water temperature is higher than 34℃ and lower than 20℃, there is little or no investment. When the water temperature is 27 ~ 3 1℃, more water should be injected.
⑤ Poor water quality, less investment, good water quality and more investment.
⑥ Use little or no drugs, and feed can't be used if it is spoiled.
⑦ Don't throw it in windy weather, and throw it less when prawns molt a lot.
⑧ Don't feed every day from 10 to 16 in hot season.
Pet-name ruby on the first day after molting, increase the feeding amount by 20%, and then feed normally.
Attending don't throw in the rainstorm, don't throw in the deterioration of water quality, don't throw in the shrimp floating head.
3.5 Disease control
Prevention, prevention first. Disinfect once every 0/5 days in the early stage, once every 0/0 days in the middle stage and once every 7 days in the late stage. Disinfect in time after heavy wind and rain, and disinfect in time if the water quality is abnormal. In addition: pay attention to patrol the pond regularly, observe the activities of shrimp, and deal with problems in time when found.
At present, there are many reasons why it is difficult to fundamentally solve the current shrimp disease. For example, farmers pay attention to environmental and water quality issues, ignoring the enhancement of shrimp immunity. Once shrimp disease is found, drugs are abused through hearsay. In addition, shrimp diseases caused by external factors are also varied.
① Too much rainfall, more cloudy days, drastic changes in water temperature and excessive temperature difference.
② Deterioration of sediments and excessive reproduction of harmful algae.
③ The basic biological feed is insufficient, and the synthetic feed has poor nutrition, slow growth, no molting and decreased disease resistance.
(4) Environmental deterioration and many pathogenic factors.
⑤ Extensive technical management and operation.
⑥ The released seedlings are unhealthy and have diseases, which brings difficulties to breeding.
3.6 timely harvest shrimp
Mainly focusing on shortening the shrimp culture cycle. Generally, after 80 ~ 90 days of culture, when the shrimp in the pond reaches the standard of about 40/kg, the shrimp should be harvested in time to prevent the sudden change of temperature from causing losses.