The characteristics of early spring climate are more and more rain, warm and cold, spring drought, late spring, and cold and rainy weather are more common. This kind of weather is a challenge to shrimp and crab breeding. How should the crab pool be managed in such a climate?
First, water level management
In the ditch-type river crab pond, it is recommended to raise the water in the middle plate of the breeding pond and increase the water level on the plate to about 0.1 to 0.2 meters. By appropriately deepening the water level and increasing the water volume, the temperature difference of the culture water body can be reduced. To minimize the adverse effects of crabs caused by unstable weather. In addition, if the middle paddles can do morning water, it will also help the wind and waves increase oxygen, and keep the pond's dissolved oxygen supply adequate.
At present, there is a lack of dissolved oxygen in Tangkou, which is mainly due to the fact that the shrimps and crabs are too concentrated in the annular ditch which accounts for not more than 1/4 of the total area of ​​the pond. The density is too large and the snails put too much oxygen consumption. Low, high-quality algae such as diatoms are in dormant state, and Elodea in the ring groove has just begun to grow. Photosynthesis is not strong, and the oxygen supply capacity is insufficient, and it is difficult to meet the growth needs of shrimps and crabs under high-density conditions. In addition, the improper fertilizer and water supply of some farmers has increased the burden of aquaculture water, resulting in the prominent phenomenon of ammonia nitrogen and nitrite exceeding the standard. If shrimps and crabs are in an oxygen-deficient environment for a long time, their appetite is not strong and their constitution will be reduced. In addition, the poisoning caused by ammonia nitrogen and nitrite exceeding the standard will make the crab and crab more fragile and extremely unfavorable to the oyster shell.
Second, water quality management
1. Timely fertilizer, water transfer. For the “Thin Water†Tongkou, we should regularly conduct biological fertilizers and water according to the weather conditions. By adding micro-ecological agents, we can achieve a “balance of bacteria and algae†and supplement some trace elements of calcium and phosphorus. This will be the first time for shrimp and crabs to pond. The shell is fully prepared to promote the smooth shelling of shrimps and crabs.
2. As the water level in the early period is relatively shallow, sunlight can easily penetrate through to the bottom of the pond, which is detrimental to the prevention of moss. For ponds where water is thin, moss is easy to grow, or moss has been produced, we suggest that farmers can use humic acid and micro-ecological agents in combination with fertilizer and water in addition to regular fertilization to synchronize the algae phase and biological control. The method does not try to kill the moss drug.
3. The main reason for the "tang" larvae and the water-white estuary is mainly due to the large-scale reproduction of zooplankton, such as cladocera and copepods, causing watery "white turbidity". Such water bodies lack of illumination, lack of algae, and dissolved oxygen in water bodies. Insufficient performance is very detrimental to the growth of aquatic grasses and shrimps and crabs. General water temperature below 10 °C recommended not to kill insects, in the case of the need to kill insects, should avoid the peak of shrimp and crab clam shell, use point kill, local kill the way to deal with, do not promote the use of the whole pond to prevent improper use of medication Losses caused, and must be carried out under conditions of sufficient oxygen on sunny days, rainy weather, and oxygen-deficient weather are prohibited.
4. This stage of snails should not be put too much at one time, otherwise it will increase the difficulty of fertilizer in Tangkou, and when the weather is not good, it is easy to cause water body oxygen deficiency. In addition, excessive supply of snails and excessively thin water quality not only caused the loss of nutrients in the water but also brought stress to the crabs, which was not conducive to the normal clam shell and growth of the crabs.
Third, the planting of aquatic plants
At present, the common aquatic plants in Tangkou include Elodea, Vallisneria, and Hydrilla verticillata. Each pond mouth should be planted according to the specific situation, and planting species should be diversified as much as possible. The planting volume accounts for 70% to 80% of the total area of ​​the pond and cross-planting should be conducted as much as possible. During the low-temperature period, we must pay close attention to whether there are dirt on the leaves of aquatic plants, whether the roots of aquatic plants are developed, and pay attention to the cultivation and maintenance of aquatic roots. The aquatic plants grow too prosperous and artificial grass cutting and water grass growth regulators can be used to regulate the growth of aquatic plants.
Fourth, feed the bait
With the increase of temperature, feed management should be gradually strengthened, and high-quality compound feeds should be selected for scientific feeding. At this stage, the amount of daily feed is approximately 1% to 1.5% of the body weight of crabs. The specific daily feeding amount should be based on the weather. , Night crab feeding activities and clam shells are flexible. Normally, it is observed at about 10:00 at night in Tongkou. If the feed intake exceeds 90%, there will be no leftovers observed the next morning, indicating that the amount of feed is just right; if the feed intake of the feed exceeds 10% Observing that there are leftovers in the early morning of the next morning, indicating that the amount of feeding is excessive, the feeding amount should be reduced or the feeding should be stopped for 1 to 2 days; if there is no food intake in the fed feed, the water quality is observed to be more turbid the next morning. Describe the lack of feeding, should increase the amount of feeding.
Summary: In the early spring when climate was unstable and rainy season, the rainy aquaculture industry was a very difficult season. However, doing some preventive work early in the spring would reduce some of these problems.
Preservation tubes are swabs with disposable virus sampling tubes to collect DNA tests for disposable nasal flocking sterile medical transport.
swabs with disposable virus sampling tubes , to collect DNA tests for disposable nasal flocking sterile medical transport.
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