New techniques for prevention and treatment of high temperature stress syndrome in river crab

In recent years, with the destruction of culture environment and the misuse and abuse of drugs, the incidence frequency of river crab is increasing day by day, in which the occurrence of high temperature stress syndrome of river crab directly leads to the failure of river crab culture. therefore, how to do a good job in the prevention and treatment of crab stress syndrome in high temperature period is very important.

Symptoms of heat stress syndrome

Do not have some characteristic symptoms, the main manifestation is that in high temperature weather every day 20 Mel 500 die, and the death number is only more and more, check the crab body, river crab often do not have the strength, fish out of the water 5 minutes will die, Gill black or the end of the rotten, claw tip red or rotten, no food in the intestines, liver color white or yellowish, mouth foam, no food in the intestines. The infected ponds generally have little or no water plants, turbid water quality or abnormal color, flooding of cyanobacteria, abnormal pH value of water, ammonia nitrogen and nitrite exceeding the standard.

Second, the cause of heat stress syndrome

Because the river crab has the obvious characteristic of "afraid of heat and not afraid of cold", when the water temperature exceeds 28 degrees, the physiological function of the river crab is disordered, the resistance drops sharply, and when the nervous system is destroyed seriously, it is often complicated with enteritis, black Gill disease, edema disease, shelling and other diseases, and the mortality rate is high, and the higher the water temperature is, the higher the mortality rate is. Often after the fall of the water temperature can automatically recover, but at this time often has been killed or injured or wiped out, so how to safely through the high temperature season is particularly important.

III. Prevalence of high temperature stress syndrome

Most of them occur in the subtropical high zone of the Yangtze River, that is, the surrounding areas near the Yangtze River, such as Nanjing, southern Jiangsu, Anhui, Honghu, Jianli and other areas, with a high incidence from June to August.

4. Measures for prevention and treatment of heat stress syndrome:

1. Reduce the use of disinfectants during the high temperature period. Once the river crab has high temperature stress syndrome, if disinfectant is used, it may stimulate a large number of river crabs to die.

2. In the river crab pond during the onset period, do not change a large amount of water. If the external water quality is good, you can add water to the pond appropriately.

3. If there is no water plant in the crab pond, first consider pulling some water peanuts and water hyacinth into the crab pond to improve the pond environment, and then use medicine to get twice the result with half the effort.

4. Multi-use water-retaining probiotics, clear bottom and quick solution at the bottom, once a month before high temperature and once every 10 Mel 15 days during high temperature.

5. River crabs with high temperature stress syndrome were soaked in 6 mu rice water for 2 hours, then sprinkled in the whole pool for 2 times. At the same time, the crabs were given "Weiming + multi-effect anti-toxin + Jinfang Huganbao + Pule". Each group was fed with 100 jin of material for 5 days.

The high temperature stress syndrome of river crab has caused great harm to our breeding, and it is the main culprit for the reduction of production in our breeding in the past two years, so we must pay attention to preventive measures to prevent it.