The shrimp seedstock panel: WSSV, AHPND, EHP and IHHNV
Hatchery and grow-out operators in the Philippines use one panel to screen whiteleg shrimp (Penaeus vannamei) and black tiger shrimp (Penaeus monodon) seedstock before shipping or stocking: WSSV, AHPND (EMS investigation), EHP and IHHNV.
AHPND, often raised by farmers as early mortality syndrome (EMS), is tested as a Vibrio investigation. AHPND causes some, but not all, EMS cases, so early deaths are also checked for other infections and water quality problems.
| Test | What it detects | Tissue to submit |
|---|---|---|
| WSSV | White spot syndrome virus, a cause of sudden deaths. | Gills and swimming legs (pleopods). |
| AHPND (EMS) | Vibrio bacteria that cause acute hepatopancreatic necrosis disease. | Stomach and hepatopancreas. |
| EHP | Enterocytozoon hepatopenaei, a microsporidian linked to slow growth. | Hepatopancreas. |
| IHHNV | Infectious hypodermal and hematopoietic necrosis virus. | Gills and swimming legs (pleopods). |
When to test shrimp
Test timing follows the production stage, not only visible signs. The table below follows the laboratory's Aquatic Disease Testing & Monitoring Handbook guidance for Philippine shrimp farms and hatcheries.
| When to test | Recommended tests | Purpose |
|---|---|---|
| Each seedstock batch, before shipping or stocking | WSSV + AHPND (EMS investigation) + EHP + IHHNV | Check the batch being purchased for these four pathogen groups. |
| Feed refusal or rising deaths (submit the same day) | WSSV + AHPND, plus histopathology, bacterial tests and water quality checks. Add EHP for slow growth | Investigate red bodies, empty stomachs or intestines, hepatopancreas changes and deaths. |
| Slow growth or marked size differences | EHP + IHHNV, reviewed with feed, growth and water quality records | Check for infection while also investigating feed and water quality problems. |
| Before grading, pond transfer or resale | Repeat the four-test seedstock panel if batches have been mixed or signs of illness have appeared | Test the batch actually being moved. Do not rely only on reports issued before mixing or illness. |
How to send shrimp samples
Free sample preservation tubes are available to every client. Tissue samples in these tubes can be transported and stored at room temperature for 72 hours.
- Use the laboratory's free preservation tubes for gill, pleopod, stomach and hepatopancreas tissue.
- Submit samples before 12 noon for a same-day report on routine tests.
- Label each sample to match the submission form: farm and batch, species and size, sample IDs, tissues and collection date.
- Note when signs began, feeding, daily deaths, water quality readings and any drugs already used.
- If the black tiger shrimp supplier has a history of MBV or YHV-1, mention it when you submit so that the test can be added to the panel.
Reading shrimp test results
A positive result identifies pathogen nucleic acid in the submitted tissue. A negative result is limited to the sample and tests actually performed. Results are read together with clinical signs, pond history and water quality records, not on their own.
An initial IHHNV-positive result needs confirmation, because fragments already present in the shrimp's own genetic material can also produce a positive result. Before grading, pond transfer or resale, repeat the four-test seedstock panel if batches have been mixed or signs of illness have appeared. Do not rely only on reports issued earlier.
Shrimp and aquatic tests on the quotation
WSSV, AHPND (toxin-gene detection), EHP, IHHNV, MBV, YHV-1, DIV1, TSV, IMNV and the Vibrio tests (V. parahaemolyticus and Vibrio spp.) are all on the laboratory's published quotation as singleplex or multiplex qPCR services, each at a quotation price in PHP. Ask for the current quotation when you submit samples.
White Spot Syndrome Virus Detection (WSSV)
Infectious Myonecrosis Virus Detection (IMNV)
Enterocytozoon hepatopenaei Detection (EHP)
Vibrio parahaemolyticus Detection (V. parahaemolyticus)
Vibrio spp. Universal Detection
AHPND Toxin Gene Detection (AHPND pirA/pirB)
Infectious Hypodermal and Hematopoietic Necrosis Virus Detection (IHHNV)
Monodon Baculovirus Detection (MBV)
Yellow Head Virus Genotype 1 Detection (YHV-1)
Decapod Iridescent Virus 1 Detection (DIV1)
Taura Syndrome Virus Detection (TSV)
Prices are quoted in Philippine pesos (PHP). Confirm the billing unit, taxes and final quotation with the laboratory before ordering.
All 24 aquatic services and prices
Results support farm and veterinary decisions. They are not government movement, export or regulatory certificates.
Shrimp testing questions
How do I test shrimp for WSSV in the Philippines?
WSSV is tested by qPCR on gill and swimming leg (pleopod) tissue. Test each seedstock batch before shipping or stocking, and submit samples the same day if you see feed refusal or rising deaths.
What is AHPND (EMS) in shrimp and how is it tested?
AHPND, often raised as early mortality syndrome (EMS), is tested as an investigation for the Vibrio bacteria that cause acute hepatopancreatic necrosis disease. AHPND causes some, but not all, EMS cases, so early deaths are also checked for other infections and water quality problems. Samples are taken from the stomach and hepatopancreas.
What is EHP in shrimp and how does it affect growth?
EHP is Enterocytozoon hepatopenaei, a microsporidian parasite linked to slow growth and marked size differences within a pond. It is tested from hepatopancreas tissue, usually alongside IHHNV.
How is IHHNV tested in shrimp hatcheries?
IHHNV is tested by qPCR on gill and swimming leg (pleopod) tissue, as part of the seedstock panel or when shrimp show slow growth. An initial positive result needs confirmation, because fragments already present in the shrimp's own genetic material can also produce a positive.
What tissue samples are needed for shrimp disease testing?
WSSV and IHHNV testing uses gills and swimming legs (pleopods). AHPND testing uses stomach and hepatopancreas, and EHP testing uses hepatopancreas. The laboratory's free preservation tubes keep tissue usable at room temperature for 72 hours in transit.
How fast can I get shrimp PCR test results in the Philippines?
Routine shrimp PCR tests are reported the same day when samples reach the laboratory before 12 noon. Turnaround for special or add-on tests is confirmed with the laboratory before you submit.
Should I test shrimp seedstock before stocking a pond?
Yes. Testing each seedstock batch for WSSV, AHPND (EMS investigation), EHP and IHHNV before shipping or stocking checks the batch for these four pathogen groups before it enters your pond. Repeat the panel before grading, pond transfer or resale if batches have been mixed or signs of illness have appeared.
Why did my IHHNV test come back positive when my shrimp look healthy?
IHHNV testing can detect genetic fragments that are already part of the shrimp's own genetic material, not only an active viral infection. That is why an initial IHHNV-positive result needs confirmation before it is treated as a true detection.