The case caused body in white or opaque white shrimp

1. Coating engine combined with curved body

This case occurs when lifting the house (floor, hooves) out of the water during the day, when temperatures are very hot. Shrimp jumped and snapped sharply, and then some of the curved body. The tail is bent to touch the chest armor, at the same time muscle tissue that runs along the middle of the body will become white. After being released back to the pond, all shrimp are curved body will die because there is no ability to straighten. Similarly, when checking shrimp fishing at the hot sun, white shrimp body and curved body. The best way to lift the restriction is not flashed out of the water or use shrimp fishing to check the hot weather.

This phenomenon sometimes occurs when the entire fan off water feeding time and then turn the fan running back. The operation of the fan unit back can cause shrimp "startling" and many children jumped into the water to create "waves" along the pond. This phenomenon usually occurs at night, a few curved body when exposed to air and switch to white muscle. Often farmers do not pay attention to this phenomenon and the next day discovered dead shrimp in ponds. This problem usually occurs when weather and high temperatures in many algae ponds bordered development. High density armor algae make the water a reddish brown shrimp and weakened. The best way to not jump out of the water shrimp shocked by the computer fan is turned on again when they reach the size of 10 grams shrimp / fish or larger farmers should maintain the staging of a few fans, even while feeding.

2. Coating body during transport from or to the pond

When trawling for shrimp for the purpose of trimming or into the pond, some shrimp stress and part or all of its muscles will be white, or sometimes a mix between white and other dark colors often as orange or red color. Most unusual colored shrimp will die. These figures are slightly different if they also recovered a few days a new body color returned to normal. The best measure is to check the health of shrimp before moving into the new pond. If it's healthy shrimp can withstand stress. If people begin to shrimp farming and found a few of them switched to white should be postponed. Water used to transport shrimp temperatures 24 - 25 ° C and have a high oxygen content.

  3. Coating posed by low oxygen content

The amount of oxygen in the pond water will be lower if not all platforms mounted paddle corresponding to the number of shrimp in ponds. Empirically, each horsepower power (HP), the computer fan will provide sufficient oxygen to 400-500 kg of white shrimp. Farmers should calculate the amount of aeration unit provides enough oxygen for shrimp in ponds. In addition, the placement of the fan unit is also very important country, installation of aeration unit in place will make the flow of waste swept into the middle of the pond, making the pond clean, and make oxygen diffusion to anywhere in the pond, especially between the pond, where the decomposition of organic matter accumulated from determining algal remains and leftovers. Decomposition of organic matter increased during the crop and this causes decreased oxygen in the water is low. Organic waste accumulates in the pond will be microbial decomposition and active life of the oxygen we need large quantities. When clouded blind or rain for several days in a row, photosynthetic algae will not be good and will not produce oxygen. Meanwhile, people living in the pond include shrimp, algae and microorganisms use oxygen. Dissolved oxygen in the water and are very low in the middle of the pond, especially the pond without regular water exchange and high stocking density. When there is more shrimp farmers to provide food and water color will be dark because the algae pond dense growth.

If oxygen in the pond from 4 ppm or higher, body colored bright white shrimp normal. But in the high-density ponds and low dissolved oxygen, the shrimp will be stress and the body will tend to turn into white or opaque. When oxygen levels are low 1.7 ppm will swim to the surface shrimp (shrimp floating head), and most will die when molting. This phenomenon has been demonstrated in the laboratory of Aquaculture Business Research Center Kasetsart University, Thailand. Shrimp are raised in an aquarium with adequate aeration. When shutdown aeration, oxygen in the water decreases and leads to reduced activity of shrimp. Shrimp do not swim much and tend to near the bottom of the tank. Shrimp will not die or swim lazily in the water even when the oxygen in the water less than 1 ppm. However, when oxygen levels fall below the most shrimp signs of muscle tissue becomes white. One of the only white at the base of the swimming legs.

  4. Coating muscle disease

In addition to the above case, the shrimp are opaque body may be pathological. In farming areas have relatively high salinity (25-35 ‰), switch to white shrimp in some parts of the body, but the cause is not due to stress caused by spores that are often identical (Microsporidian). In addition, infected shrimp (IMNV - Infectiuos myonecrosis virus) can also be switched to white. The small necrotic spots start at the tail and then spreads throughout the body. Cumulative mortality rate is quite high, about 40-70%. So far there is no cure, but mostly still apply preventive measures such as not using synthetic infected broodstock in hatcheries, remove the shrimp from the ponds and diseases as well the pond.

Prof. Dr.. Chalor Limsuwan, Kasetsart University, Thailand - Journal of Fisheries Asia Practice, No. 2, May 04 - 06/2011. according http://www.bayeranimal.com.vn