Systemic vibriosis damages aquaculture shrimp. Poor culture systems can increase disease mortality. Shrimp aquaculture is profitable but needs proper administration to avoid systemic vibriosis. Vibrio harveyi, a seawater bacteria, infects crustaceans through their gills or lesions. Infected crustaceans show fatigue, hunger loss, and exoskeleton discoloration.
The disease kills crustaceans within days. Systemic vibriosis can be prevented by keeping water purity, stocking density, and diet. Early diagnosis and antibiotic therapy can increase shrimp survival. For a healthy and lucrative shrimp culture business, shrimp farmers must avoid and manage systemic vibriosis.
Systemic Vibriosis Management in Shrimp (Prawn)
The Pathogen Responsible for Systemic Vibriosis
- Systemic vibriosis can be caused by various species of Vibrio bacteria, including V. alginolyticus, V. parahaemolyticus, V. anguillarum, V. vulnificus, V. damsella, V. fluvialis, and V. mimicus.
- These bacteria can infect Shrimp through wounds or their gills and cause symptoms such as lethargy, loss of appetite, and discoloration of the exoskeleton.
- The mortality rate can increase if left untreated, and proper management practices, including maintaining good water quality, can prevent the occurrence of systemic vibriosis.
- Early detection of the disease and timely treatment with antibiotics can also improve the survival rate of infected Shrimp.
Spread and Transmission of Systemic Vibriosis in Shrimp
- Systemic vibriosis can be spread through direct or indirect contact with infected Shrimp or contaminated water. The bacteria can infect healthy Shrimp through wounds or their gills.
- Poor water quality, overcrowding, and stressful conditions can increase the susceptibility of shrimp to the disease. The use of contaminated equipment and the improper disposal of dead Shrimp can also lead to the transmission of the disease.
- Proper management practices, including regular water quality testing and disinfectants, can reduce the spread of the disease.
What are the Signs and Symptoms of Systemic Vibriosis in Shrimp?
- Infected shrimps display several major symptoms, including:
- Opaque abdominal musculature
- Pale gill filaments
- Melanized (black) ventrolateral edges of the carapace
- Flared-up gill covers (branchiostegites) resembling German helmets.
- Blisters on the shell
- Brownish to black cuticular.
- Shrimp may exhibit brownish to black cuticular lesions and dorsal flexure of the abdomen.
- Reddish discoloration of the body and appendages is also a symptom of the disease.
- Infected Shrimp may have turbid hemolymph with delayed clotting time.
- Post-larval stages may not consume feed and lack fecal strands.
- Necrosis of appendage tips may occur, causing them to become brownish.
- Swarming bacteria can be observed in the body cavity of moribund shrimp larvae under a microscope.
- Early detection and treatment can improve the survival rate of infected Shrimp.