Soft shell is also one of the main diseases in shrimp farming. It has a great impact on the growth of shrimp. In severe cases, more shrimps will die. The causes of soft shells of shrimps may be as follows:

(1) Long-term insufficient feeding or unreasonable feed formula causes the shrimps to lack nutrients and become hungry.

(2) Phosphorus is the main element in the formation and calcification process of shrimp carapace. When the content of dissolved phosphorus in the pool water is too low, the shrimp's phosphorus intake is insufficient, which results in soft shells.

(3) The culture water body lacks an appropriate amount of calcium and cannot meet the needs of shrimp for normal molting, especially in low-salinity culture.

(4) The breeding density is too high, resulting in poor breeding environment, deterioration of water quality, and softening of shrimp shells.

(5) Especially in fresh water, nitrite has a greater impact on shrimp. When the content exceeds a certain concentration (different in different water bodies, generally exceeding 0.3 mg/L), it will cause soft shells of shrimps.

(6) The concentration of organotin or organophosphorus pesticides in the pool water is too high, which inhibits the synthesis of chitin in the shrimp carapace.