01 · AquaGrow
What it is
Taura syndrome can affect vannamei, with acute illness around moulting and a possible carrier phase. This international disease-awareness guide is not a claim that TSV is causing a local outbreak.
Signs to watch for
- Reddish tail fan or appendages, sometimes a generally pale red body.
- Soft shell, empty gut, reduced feeding or weakness around moulting.
- Deaths during an acute episode; some survivors develop dark cuticular lesions.
Common causes
- The disease is caused by Taura syndrome virus, an RNA virus. Acute, transitional and chronic phases can look different.
- Similar signs can have other causes: Vibriosis, handling injury and oxygen or water-quality stress. WSSV and other conditions with red colour or soft shells.
How to confirm the cause
- Discuss TSV-specific RT-PCR (a laboratory test for RNA genetic material) and appropriate histology (microscope examination of tissue) with a qualified diagnostic laboratory.
- Clinical appearance alone does not confirm TSV. Suspected unusual findings need professional interpretation and authority-led confirmation where required.
What to do immediately
- 1
Check oxygen and water quality immediately, without delaying laboratory contact.
- 2
Record moult stage, feed intake, mortality and the affected seed lot.
- 3
Consult fisheries or aquatic-health authorities if your professional suspects an unusual listed disease.
- 4
Keep affected stock, equipment and water separate. Agree on safe disposal and any harvest or discharge with your professional.
Prevention: your practical checklist
- Use traceable seed and relevant health screening; retain source and transport records.
- Separate ponds and avoid raw crustacean feeds or movement of sick shrimp.
- Maintain stable conditions during moulting and control carrier access through the farm’s biosecurity plan.
- Assign nets, trays and boots to each pond; clean and disinfect equipment under the farm’s biosecurity plan.
- Keep seed-batch, feeding, water-quality and mortality records so a change is noticed early.
When to call an expert
- Call an aquatic animal health professional urgently if deaths rise, shrimp gather at the surface, or breathing becomes difficult. Check dissolved oxygen while arranging help.
- Arrange an assessment if these signs persist, feeding falls or growth stays behind the crop trend. Send water readings, recent input records and photographs; ask the laboratory how to collect samples.
Farmer questions
Does every red tail mean TSV?
No. Injury, bacteria and environmental stress can produce similar colour changes. Testing is required to distinguish causes.
Do these guides establish India’s disease status?
No. They describe disease awareness. Use current official surveillance and competent-authority advice for local status, movement or reporting decisions.
What should I record before asking for help?
Note the pond ID, culture day, recent deaths, feed intake, water test readings and recent changes. Ask the laboratory about suitable samples before adding a treatment. A photograph alone cannot confirm the cause.
Sources & further reading
AI-assisted educational content and translations, source-checked 17 October 2026. Not an individual diagnosis or prescription. Independent aquaculture-health and native-language specialist approvals have not been supplied. Sources do not endorse AquaGrow.
- Infection with Taura syndrome virus ↗World Organisation for Animal Health — Aquatic Manual (2023)
- Taura syndrome — clinical signs and phases ↗NACA / Australian Government — historical Asia–Pacific identification field guide; not current surveillance