Let's take a concrete look at what conditions are needed for breeding river crabs and what we need to pay attention to.
First, the water source is sufficient, and the water quality is fresh and pollution-free.
Eriocheir sinensis is very sensitive to water quality, and it is impossible to raise crabs with unqualified aquaculture water.
If the crab pond enters the polluted water, it will accumulate toxicity in the crab, affect the quality of the crab and be harmful to human body. On the other hand, it caused large-scale death of river crabs and caused important economic losses.
Second, the construction of living environment should be reasonable.
Crab culture should not only have sufficient water, wide water depth, convenient irrigation and drainage, less sludge, fresh water quality and rich bait sources, but also create a good living environment for crabs according to their characteristics.
In order to have deep water area and shallow water area, the ratio of deep water area and shallow water area should be above 3∶ 1
Three, crab seedlings should be introduced and used without pathogenic microorganisms, with diseases or pathogens lurking and not disinfected. When the disease conditions are ripe, it can cause a certain crab disease epidemic or epidemic situation.
When buying crab seedlings, be sure to check whether there are pathogens and put them into the crab pond after disinfection.
Practice has proved that crab species introduced from epidemic areas get sick in metropolis, while healthy crab species rarely get sick.
Fourth, there must be a reasonable breeding model.
In the process of breeding commercial crabs, some crab farmers always raise some young crabs in May and June. When the crabs are harvested at the end of the year, they will catch the mature crabs and continue to raise the remaining crabs, and then replenish the young crabs in May and June of the following year.
Not only did they fail to see its harmfulness, but they thought it was a good way to raise crabs. As a result, the phenomenon of big crabs killing small crabs and soft-shelled crabs is very serious.
The correct way is: the stocked Eriocheir sinensis fry should ensure the same specifications, and the pond should be thoroughly cleaned and disinfected within a breeding cycle.
Fifth, feed nutrition should be reasonable. In the process of raising crabs, some crab farmers lack feeding, which leads to slow growth and emaciation of crabs; Some people throw more bait, but the quality of bait is poor, which can not meet their nutritional needs; Some people only feed plants and not animals, which leads to the lack of protein.
These incorrect practices make Eriocheir sinensis lack nutrition and weak disease resistance, so the probability of suffering from various diseases will be high.
Therefore, to raise a pool of crabs well, it is necessary to manage them according to their nutritional needs and let them grow healthily.