Winter temperatures pose new challenges for aquaculture, especially for the warm-water fish grouper, which is at a high risk of disease during this season.
What are the common diseases? How to prevent and control it? These are the concerns of aquatic people. Today, we will introduce in detail the common diseases and prevention and control methods of grouper in the low temperature period, hoping to help you.
Common diseases of grouper in winter
Bacterial septicemia
Bacterial septicemia is one of the most common diseases of grouper in winter. The disease is mainly caused by bacterial infection, and the fish often show the symptoms of swimming weakness, appetite loss, black or green skin.
The autopsy showed that the liver, intestine, swim bladder and other parts were obviously congested, the spleen was black, and the kidney was swollen in severe cases. If not properly handled after the onset, the number of deaths will increase rapidly, seriously affecting the survival rate.
enteritis
Enteritis is also one of the common diseases of grouper in winter. The disease can be caused by improper feeding practices (such as poor feed quality), sudden temperature changes, or other environmental stresses (such as deteriorating water quality).
Sick fish can suffer from intestinal bleeding, white faeces and loss of appetite. According to the different causes, enteritis can be divided into bacterial enteritis, stress enteritis and parasitic enteritis three types.
Rot body
Vibrio Harveyii is the main bacterial pathogen causing grouper rot. The symptoms are usually manifested as rotting, protruding eyes, blindness, cataracts, etc., on the surface of the fish body, with the aggravation of the disease, the lesion area will further expand, the depth of the ulcer will increase, and the serious will lead to death.
parasitosis
In winter, although parasitic diseases are relatively rare, they still exist. Common parasites include wheel worm, sporidium, cryptocarya, etc. These parasites will attach to the body surface or gills of the grouper, absorbing the tissue cells of the fish as nutrients, resulting in symptoms such as wasting, slow swimming, and difficulty breathing.
Prevention and control method
1. Strengthen pond management
In winter, pond management should be strengthened, including deepening the water level, increasing the water fertility to enhance the insulation effect, and regularly cleaning the silt and impurities at the bottom of the pond.
At the same time, water quality indicators, such as dissolved oxygen, ammonia nitrogen, nitrite, etc. should be regularly tested to ensure good water quality.
2. Feed properly
In winter, grouper's appetite will weaken, and feeding should be selected in the time period of high water temperature every day for regular, fixed, quantitative and quality feeding.
When the temperature changes greatly, the material should be reduced or stopped in time to avoid problems such as indigestion and enteritis caused by excessive feeding.
3. Enhance fish body resistance
You can regularly feed some immune-enhancing drugs or health products, such as vitamin C, bile acids, liver protection products. To improve the immunity and disease resistance of fish.
4. Timely treatment of disease
Do not blindly use insecticides in the face of parasitic diseases to avoid aggravating stress and death. It should be confirmed that the pathogen should be properly administered, and the safe concentration of the drug on the fish body should be confirmed, and high dose drug therapy should not be blindly pursued.
The use of drugs is appropriate and standardized to avoid damage to fish or environmental pollution caused by abuse.
5. Be prepared for emergencies
Winter temperatures are changeable and emergency preparations should be made. In case of extreme weather conditions such as sudden temperature drop, timely measures should be taken to protect the fish from freezing damage. At the same time, emergency medicines and equipment should be prepared to deal with possible disease problems.