HOW TO DEAL WITH PARASITES WHILE REARING SHRIMP

Along with the development of the shrimp industry, high-density rearing has become popular, leading to pollution of the environment, which is also a condition for pathogens to thrive, including parasites. When the parasites proliferate, it will create conditions for the development of intestinal infections, especially white feces syndrome, which greatly affects the efficiency of the crop.

Reasons:

• The two-celled parasite (Gregarine) parasitizes the shrimp intestine and has an intermediate host of mollusks and arthropods. Gregarine often encounters shrimp 40-50 days after stocking in high-density ponds during hot weather and dirty pond bottoms. Shrimp infected with Gregarine often grow slowly, causing damage to the midgut mucosa, creating an opportunity for harmful bacteria to invade and cause intestinal diseases for shrimp.
• Enterocytozoon hepatopenaei (EHP) infects epithelial cells of shrimp hepatopancreas tubules. EHP is an obligate intracellular parasite, that uses nutrients and energy stored in the hepatopancreas, causing slow growth and sizing of shrimp. EHP infects all stages of shrimp development. The spread is very fast. It does not cause shrimp death but is an opportunity agent for Vibrio to attack other diseases such as white feces, and hepatopancreatic necrosis.
• Because Vermiform (worm form) is present in the hepatopancreas tubule, and midgut of shrimp. Vermiform causes reduced feed intake, and growth retardation and are associated with white feces disease in shrimp.

Signs of shrimp infection with parasites:

• Gut zigzag, “twisted spring”.
• The shrimp intestinal tract is broken into segments or there is no food in the intestinal tract.
• Shrimp intestines are curved, and enlarged, with pinkish-yellow fluid.
• Dot the intestinal rice to burn the 6th (tail cap).
• Diseased shrimp turn milky or milky, when the shrimp is larger, it is easier to see, many have muscle opacities in the back or the end of the body.

Harms:

Although it does not cause mass mortality in a short time, it will cause some unexpected death throughout the crop, slow growth, and loss of appetite, creating favorable conditions for pathogens to attack white feces disease and hepatopancreatic necrosis. affect the yield and quality of farmed shrimp.

Treatment:

• Thoroughly improve the pond.
• Treat well the water supply to the pond.
• Good control of water quality: kill intermediate hosts, periodically disinfect, treat the excess organic matter, pond bottom sludge, regularly check dissolved oxygen concentration (>4ppm) preferably 5ppm (stimulant) Shrimp eat well, grow fast, are less susceptible to disease attacks).
• Control feed quality and feeding quantity: ensure clean feed, and limit excess feed causing organic pollution.
• Using probiotics:
  • Probiotics: stabilize intestinal bacteria, increase the density of beneficial bacteria in shrimp intestinal tract; specific strains of microorganisms specialized in inhibiting parasites; microbiological treatment of water and pond bottom.
  • Enzyme preparations: treatment of organically polluted pond water.

Suggested solutions from Thai Nam Viet:

Using probiotics will thoroughly treat parasites and intestinal diseases but still ensure the normal growth of shrimp, help shrimps in large sizes, limit damage, and maintain productivity for humans. feed.