Do you know the management and disease control methods of crabs before and after stocking?

1. Preparations before releasing the crabs

First of all, we must make a plan. The crabs in the pond will be sold out, the pond will be cleaned and disinfected, the water will be detoxified, aquatic plants will be cultivated, and the crabs will be selected. Matters such as the purchase date and purchase date must be carefully arranged. At the same time, we must also pay attention to the weather forecast, make adjustments to the arranged plans at any time, and have contingency measures and preparations.

2. Matters concerning stocking crabs

The most important thing when choosing crabs is to have a clear understanding of the source, including the harvesting method and time. Stocking should be carried out when the weather is fine and the temperature is preferably between 4 and 10°C. When stocking, the water depth in some areas must be more than 1 meter.

As for whether to soak crabs with drugs when stocking them, the author’s opinion is that it should be decided according to the situation. One situation is that the amount of stocking is not large and the operation is easy and fast, so it is necessary to take a medicinal bath. Choose polyiodine solution and Yujing Shuiwu, the dosage is 10 to 50 ml of 1 ton of water, and the time is 30 to 10 minutes. The specifics should be grasped flexibly and not dogmatically.

3.? Planting of aquatic plants

The planting time of aquatic plants can be determined according to local customary methods. Some are planted before planting, some are planted after planting, and most are cultivated after the arrival of spring. These do not have much impact on production, the main purpose is to ensure that aquatic plants flourish in spring.

4. Problems with releasing snails

First of all, we should pay attention to releasing snails, and we must plan and organize the snails. Due to the limited resources of snails, the quality and price of snails are high in many places, resulting in some dead snails, miscellaneous fish, rotten shrimps, parasites or pests among the snails released. Some ponds have large areas and few manpower, so they are put in haphazardly, making it impossible to operate according to scientific requirements. If this is the case, it is better to put in less snails. If it doesn't work, just leave them out.

Snails must be cleaned, removed and disinfected before being released. For large ponds, it should be carried out in batches. Do not just rush for time and ignore the quality of the delivery.

5. Disinfection after the crabs are stocked

After the crabs have been stocked, disinfection can be carried out once the crabs have basically adapted for a few days. It is best to use Yujing Shuiwu 200 g/mu, this is very safe and will not have any adverse effects.

6.? Overwintering management and disease control

Generally, crabs have less activity in winter. If they encounter water with poor bottom quality, they are easily parasitized by ciliates or attached to some filamentous algae. , before officially entering the winter, you can use a fiber truck to purify 350 grams/acre of water at noon on a sunny day and then splash it, mainly in deep water areas.

Generally, crabs do not need to be fed artificial feed in winter. Artificial feed is rarely eaten, but instead pollutes the substrate and causes moss to grow on the bottom of the pond, making it more difficult to start breeding. The best way to prevent moss is to eliminate the presence of organic matter at the bottom of the pond, and be careful when cleaning and disinfecting the pond. Of course, it is also important to keep the water level of the crab pond stable in winter and add new water in time.

Preventing crabs from being hypoxic or freezing is the central task of winter management. There is a lot of organic matter at the bottom of the pond, thick silt, and inappropriate placement of snails, etc., which will cause hypoxia at the bottom and make it difficult to detect. This situation often occurs when the temperature changes greatly and the temperature difference between the surface water temperature and the bottom water temperature is too large. If you encounter this situation, just use 2 kilograms of water and 110 + 500 grams of granular oxygen to scatter. The main reasons why crabs are frozen in winter are due to insufficient water depth, deterioration of bottom quality, or freezing of the pool surface, resulting in lack of oxygen at the bottom of the pool (crabs have to climb up).

Winter management of crab ponds is very critical, which is an important reason why the survival rate of the first molt is not high.