The vannamei entering the harvest season, when the shrimp farmers often into the autumn, the peak incidence of over-easy lax in preventing a farmed shrimp ponds, in normal circumstances, does not appear within 3-5 days died;its aquaculture production process in two weeks or one week, individual shrimp death, their group's activities, food intake and body color, gills nor abnormal phenomenon can be seen as a natural reduction, but if the shrimp in 1-2 dayspool of more than 1% mortality, may be the initial of the disease, should be carefully observed, detailed view, pay attention to the following aspects.

A shrimp the vibrant and swimming ability weakened

Health disease usually shrimp habitat breeding water in the lower or close to the bottom, the general is not easy to see; sometimes pool dike can be found in some shrimp active group, but the movement quickly, jumping, swimming strong.

Shrimp disease activity is weak, slow swimming, artificial stimulation, unresponsive, not to escape, some spin on the surface of the water or up and down without directional swimming; Portuguese volts or side shallow water at the edge of the pool; abnormal Some habits .

Second, the decline in food intake or stop feeding.

Healthy disease-free shrimp group feeding (feeding) visible fought over active sampling view, half an hour later, more than 80% of the shrimp gastrointestinal full 3-5 days of continuous observation, can be seen growing well, the shrimp was built strong. Disease shrimp, regular feeding, half an hour after sampling observed more than 50% of the shrimp an empty stomach, the pool appeared bait; non-acute, 5-6 days of continuous observation of the growth of shrimp but not the increasingly emaciated, bait increase.

Body color and gill abnormalities

Healthy disease-free shrimp body transparent or translucent body color is normal, bright, surface dirt, algae, protozoa attached; clean through both sides of the carapace, gills clearly visible. Sick shrimp body color gray, crustaceans surface pigment spots increased, and some appear white spots, brown spots, crustaceans ulcers; broken attached mutilated missing, tentacles, some appendages turn red a whitish muscle spasm was cramping shrimp shrimp; gill black, some yellow gills or white gills, attached to the gills of dirt or sessile protozoa, algae.