01 · AquaGrow
What it is
PCR is a laboratory test for selected genetic material. Specific pathogen free (SPF) describes a stated pathogen scope and controlled history, not immunity or freedom from every disease. Interpret reports for the actual samples, target and lot.
Signs to watch for
- A report has an unexpected, invalid or unclear result.
- Lot identity, sampling date or tested targets do not match the dispatch.
- A claim of complete disease freedom relies on one negative test or SPF ancestry.
Common causes
- Sample, method or reporting limitations need clarification.
- Lot mix-ups or missing records prevent interpretation.
- Detection of a target is confused with proving the cause of illness or the health of every animal.
How to confirm the cause
- Verify the original report, laboratory, target, sample identity, date and method directly.
- Ask the diagnostic professional about sample suitability, pooling, inhibition and any confirmation or repeat sampling needed.
What to do immediately
- 1
Keep the lot separate and pause dispatch if its health status or report identity is unresolved.
- 2
Contact the issuing laboratory and hatchery health professional; share the original report and batch history.
- 3
Follow the professional’s confirmation, containment and communication plan. Do not change a report or advertise unqualified disease-free status.
Prevention: your practical checklist
- Keep a defined health-screening plan with traceable samples.
- Verify report-to-lot links before release.
- State tested targets and limitations honestly in customer documents.
When to call an expert
- Contact the laboratory promptly for a positive, invalid or inconsistent result.
- Deaths or suspected spread require urgent health assessment alongside report clarification.
Farmer questions
Does a negative PCR certify every shrimp?
No. It applies to the sampled material, tested target, method and time. Sampling, life stage and assay limitations matter. Follow the appropriate batch assessment plan.
Does SPF mean resistant to all diseases?
No. SPF is not the same as resistance and does not cover every pathogen. Biosecurity and appropriate screening remain necessary after purchase.
Does a positive result prove why the batch died?
Not automatically. Detecting a pathogen and establishing the cause of a clinical event are different questions. Interpret results with animal findings, water and the history.
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.
- WSSV diagnostic sampling and interpretation ↗WOAH Aquatic Manual, linked chapter labelled 2023; target-specific guidance, not whole-batch freedom
- SHAPHARI hatchery operating guidelines — production, biosecurity and records ↗MPEDA; linked guideline, not AquaGrow certification or a legal-compliance audit
- Hatchery health management: quarantine, testing and production-stage separation ↗FAO; historical Asia–Pacific framework, not current Indian import rules
- Hatchery operations and assessment framework (2007) ↗FAO FTP 446; historical P. monodon manual, not a vannamei treatment protocol