How to prevent and treat high-temperature stress syndrome in river crabs? Detailed explanation of new technology
New technology for preventing and treating high-temperature stress syndrome in river crabs
(Agricultural Wealth Network) In recent years, with the destruction of the aquaculture environment and the misuse and abuse of drugs, the incidence of disease in river crabs has also increased day by day. Among these, the occurrence of high-temperature stress syndrome in river crabs has directly led to the failure of river crab farming. Therefore, how to effectively prevent and treat crab stress syndrome during the high-temperature period is crucial.
I. Symptoms of high-temperature stress syndrome
There are no characteristic symptoms. The main manifestation is deaths of 20-500 crabs per day in high-temperature weather, with the number of deaths increasing more and more. Upon examining the crab body, the river crabs are often weak and die 5 minutes after being removed from the water. The gill filaments turn black or the ends rot, the tips of the claws turn red or rot, the intestine contains no food, the liver turns white or pale yellow, the crab foams at the mouth, and the intestine has no food. Affected ponds generally have little or no aquatic grass, turbid or abnormally colored water, cyanobacteria blooms, abnormal water pH, and ammonia nitrogen and nitrite levels exceeding standards.
II. Causes of high-temperature stress syndrome
Because river crabs have the obvious characteristic of "fearing heat but not cold," when the water temperature exceeds 28 degrees, the physiological functions of river crabs become disordered, resistance drops sharply, and in severe cases the nervous system is damaged. It often occurs concurrently with enteritis, black gill disease, edema disease, incomplete molting disease and other diseases, with a high morbidity and mortality rate, and the higher the water temperature, the higher the mortality rate. It often heals automatically after the water temperature drops in early autumn, but by then more than half or even all of the stock has usually died. Therefore, how to safely pass through the high-temperature season is particularly important.
III. Prevalence of high-temperature stress syndrome
It occurs mostly in the subtropical high-pressure 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 higher incidence rate from June to August.
IV. Prevention and treatment measures for high-temperature stress syndrome:
1. Reduce the use of disinfectants during the high-temperature period. Once river crabs develop high-temperature stress syndrome, using disinfectants may stimulate massive deaths of river crabs.
2. For river crab ponds in the disease outbreak period, do not change large amounts of water. If the external water quality is good, an appropriate amount of water may be added to the pond.
3. If there is no aquatic grass in the crab pond, first consider adding some alligator weed and water hyacinth to the crab pond to improve the pond environment, and then use drugs for treatment, which can achieve twice the result with half the effort.
4. Use water-quality-preserving probiotics, Pond Bottom Clearing, and Bottom Habitat Rapid Relief frequently. Use once a month before the high-temperature period, and once every 10-15 days during the high-temperature period.
5. For river crabs with high-temperature stress syndrome, use one bag of Jinweian per 6 mu-meters, soak in water for 2 hours, then splash over the whole pond, using it twice consecutively. At the same time, feed orally "Weimian + Duoxiao Kangdu + Jinfang Huganbao + Pule," processing each group into 100 jin of feed, and feed continuously for 3-5 days.
High-temperature stress syndrome in river crabs causes very great harm to our farming and has been the chief culprit behind our production reductions in the past two years. Therefore, we must attach importance to preventive measures and guard against trouble before it happens.
I. Symptoms of high-temperature stress syndrome
There are no characteristic symptoms. The main manifestation is deaths of 20-500 crabs per day in high-temperature weather, with the number of deaths increasing more and more. Upon examining the crab body, the river crabs are often weak and die 5 minutes after being removed from the water. The gill filaments turn black or the ends rot, the tips of the claws turn red or rot, the intestine contains no food, the liver turns white or pale yellow, the crab foams at the mouth, and the intestine has no food. Affected ponds generally have little or no aquatic grass, turbid or abnormally colored water, cyanobacteria blooms, abnormal water pH, and ammonia nitrogen and nitrite levels exceeding standards.
II. Causes of high-temperature stress syndrome
Because river crabs have the obvious characteristic of "fearing heat but not cold," when the water temperature exceeds 28 degrees, the physiological functions of river crabs become disordered, resistance drops sharply, and in severe cases the nervous system is damaged. It often occurs concurrently with enteritis, black gill disease, edema disease, incomplete molting disease and other diseases, with a high morbidity and mortality rate, and the higher the water temperature, the higher the mortality rate. It often heals automatically after the water temperature drops in early autumn, but by then more than half or even all of the stock has usually died. Therefore, how to safely pass through the high-temperature season is particularly important.
III. Prevalence of high-temperature stress syndrome
It occurs mostly in the subtropical high-pressure 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 higher incidence rate from June to August.
IV. Prevention and treatment measures for high-temperature stress syndrome:
1. Reduce the use of disinfectants during the high-temperature period. Once river crabs develop high-temperature stress syndrome, using disinfectants may stimulate massive deaths of river crabs.
2. For river crab ponds in the disease outbreak period, do not change large amounts of water. If the external water quality is good, an appropriate amount of water may be added to the pond.
3. If there is no aquatic grass in the crab pond, first consider adding some alligator weed and water hyacinth to the crab pond to improve the pond environment, and then use drugs for treatment, which can achieve twice the result with half the effort.
4. Use water-quality-preserving probiotics, Pond Bottom Clearing, and Bottom Habitat Rapid Relief frequently. Use once a month before the high-temperature period, and once every 10-15 days during the high-temperature period.
5. For river crabs with high-temperature stress syndrome, use one bag of Jinweian per 6 mu-meters, soak in water for 2 hours, then splash over the whole pond, using it twice consecutively. At the same time, feed orally "Weimian + Duoxiao Kangdu + Jinfang Huganbao + Pule," processing each group into 100 jin of feed, and feed continuously for 3-5 days.
High-temperature stress syndrome in river crabs causes very great harm to our farming and has been the chief culprit behind our production reductions in the past two years. Therefore, we must attach importance to preventive measures and guard against trouble before it happens.