01 · AquaGrow
What it is
Sudden larval deaths are an emergency sign, not a named disease. Water, air, chemicals, feed and infections may be involved. Stabilise the system and arrange assessment at the same time.
Signs to watch for
- New deaths increase quickly.
- Larvae become weak or stop normal feeding and swimming.
- More than one tank changes after a shared water or feed event.
Common causes
- Air or water control fails.
- An input, feed or source-water problem affects the tank.
- Infection or cross-contamination occurs; appearance alone cannot establish which.
How to confirm the cause
- Check DO, air supply, water readings and recent shared inputs immediately.
- Contact a diagnostic professional for appropriate fresh samples and a combined water/animal investigation.
What to do immediately
- 1
Call the hatchery health professional now and restore the planned safe air supply; check DO.
- 2
Stop suspected new inputs or water supplies while retaining labels and batch records. Avoid an unplanned whole-system correction.
- 3
Keep the affected lot, tools and waste separate. Do not dispatch seed, mix batches or release untreated suspect water.
- 4
Record the timeline and ask the laboratory how to collect samples before applying treatment. Do not wait for test results to address a clear air failure.
Prevention: your practical checklist
- Use daily stage, survival, feed and water checks with clear escalation rules.
- Track water and live-feed lots across tanks.
- Keep backup systems and containment procedures ready.
When to call an expert
- Any rapid larval loss or severe distress needs immediate professional support.
- Escalate promptly if several tanks or dispatched seed from the same lot are affected.
Farmer questions
Should I wait for PCR before restoring air?
No. Restore safe, planned oxygen support while arranging sampling. PCR (a laboratory test for genetic material) addresses selected pathogens, not a power or blower failure.
Can a photograph identify the cause?
Not reliably. A useful investigation combines the timeline, water readings, management records, examination and appropriate tests.
Should I flush the affected tank?
Do not release suspect water or stock into shared systems. A professional should plan containment, water handling, waste treatment and any restart.
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.
- SHAPHARI hatchery operating guidelines — production, biosecurity and records ↗MPEDA; linked guideline, not AquaGrow certification or a legal-compliance audit
- Luminescent bacteria in shrimp hatcheries — better management advisory ↗ICAR-CIBA Technical Advisory 1; historical 2009/2010 publication, not current outbreak surveillance
- Hatchery operations and assessment framework (2007) ↗FAO FTP 446; historical P. monodon manual, not a vannamei treatment protocol