When dissolved oxygen content in aquaculture water is over-saturated, the risk of "bubble disease" is considerable. This bubble disease is caused by the supersaturation of certain gases in the blood of fish or shellfish, and then the formation of bubbles in the animal body. For fish, it often occurs in the fish fry and fish species stage. There are two types of bubbles in the intestine of fish fry, one is that bubbles appear in the intestine of fish fry, which makes it impossible to sink and die; the other is that there are many small bubbles attached to the surface and fin tissue of fish fry or fish fry, and the gill filament makes fish float and swim abnormally. Therefore, it should be noted that the death rate of oxygen bubble disease is lower than that of nitrogen bubble disease. When dissolved oxygen saturation decreases, the bubble disappears easily and the diseased fish can recover quickly.
   In order to get more oxygen and consume excessive energy in the body, when the animal is in this state for a long time, the feed cannot be very good into meat and fat, making the feed coefficient increased, affecting the output of cultured animals. The bait coefficient of fish at 3 mg/L dissolved oxygen was twice as high as that at 4 mg/L. The fish growing at 7 mg/L dissolved oxygen grew 20-30% faster than that growing at 4 mg/L dissolved oxygen. The feed coefficient is 30% to 50%. The appetite of fish and shrimp increased obviously when the dissolved oxygen content in water was above 4.5 mg/L, and the best value of the diet coefficient was obtained when the dissolved oxygen content was above 5 mg/L.