It’s the peak sales period for crayfish again, but this period is also a more troublesome stage for farms. Due to the Beginning of Summer solar term, the climate is warm and humid, and the temperature changes frequently and there is more precipitation. Raising lobsters can easily cause a variety of diseases. Let’s take the common white spot disease of crayfish as an example to learn more about the causes, symptoms, and targeted preventive measures of crayfish white spot disease. Compared with healthy crayfish, crayfish with leukoplakia have reduced activity and reduced eating, and are accompanied by water discharge from the body.

If you are good at peeling off the head shell, you will find that it falls off easily. In addition, the color of the lobster liver will turn white when it is swollen. The most obvious symptom of illness is the oval white spots on the shell of the shrimp. The maintenance of good water quality conditions can bring certain preventive and therapeutic effects. Usually, you should pay more attention to the disinfection and cleaning of the pond. In terms of feeding, it is recommended to feed full-price concentrated feed, plus antiviral drugs or immune vulcanization accelerator concentrate, which can enhance the immunity of crayfish.

During a period of sustained high temperature or when the ambient temperature changes significantly, crayfish will eat a larger amount during this period, but it is important to avoid overfeeding, which may cause excessive nutrients or accumulation of concentrated feed. Maintain the water level and pay attention to the environmental temperature stress response caused by strong changes in water temperature. At the same time, you must also pay attention to the stocking density. Avoid catching crayfish frequently to avoid disturbing the crayfish too much and causing an overreaction. There were no outstanding symptoms in the early stage, just few activities, slow behavior, and significantly reduced eating. In the later stage, water accumulates in the body, the head shell is easy to detach, white spots appear on the head and chest, and the muscle tissue becomes red, which quickly spreads to a large scale and causes death, and even infection of river shrimp.

During periods of continuous high temperature, especially after long-term rainy days, phytoplankton die in large numbers, the water surface turns blue, and phytoplankton such as rotifers breed in large numbers. The water body and sediment are severely polluted, and the oxygen supply at the pond entrance is stopped due to power outage or equipment failure. Shrimp are prone to develop this disease. Crayfish size is not associated with increased pathogenicity, but it is only when individuals are larger that they can ingest virus-carrying microorganisms. In addition, crayfish have the habit of cannibalizing each other, and white spot virus infection is highly pathogenic and the main infected cells are not selective. For example, the prevalence of somatic cells in the dermis under the hard shell reaches 100%. As a result, the above cell tissues cannot be compensated, and the crayfish may die in a short period of time.