01 · AquaGrow
What it is
EHP damages the hepatopancreas, the shrimp’s digestive organ. A crop may remain alive but grow poorly, making feed and harvest planning difficult. Compare repeated weight samples with feed records rather than judging one small shrimp.
Signs to watch for
- Average weight falls behind the crop’s previous growth trend.
- The sampled population develops a widening range of sizes.
- Feed conversion worsens; these observations are warning signs, not confirmation.
Common causes
- EHP is a fungal-related microsporidian parasite that multiplies inside host cells. It is widely called Enterocytozoon hepatopenaei; a 2023 taxonomic redescription proposed the name Ecytonucleospora hepatopenaei. Both names occur in technical references, and the abbreviation remains EHP.
- Similar signs can have other causes: Unequal feed access, crowding, or unsuitable water conditions. Other digestive-organ infections or nutritional problems causing poor growth.
How to confirm the cause
- Ask an appropriate laboratory for a validated EHP-specific PCR (a laboratory test for genetic material) test and tissue examination where indicated. The professional should select representative shrimp and suitable hepatopancreas samples.
- Discuss assay specificity, sampling, and repeat testing. A negative sample is not a guarantee for the whole batch; a PCR-positive environmental sample does not by itself prove viable infection.
What to do immediately
- 1
Contact a qualified aquatic animal health professional and arrange laboratory sampling before changing management.
- 2
Record weight distribution, feed use, survival estimates, and pond identity for the assessment.
- 3
Restrict movement of shrimp, sludge, water, and equipment between affected and unaffected ponds.
- 4
Review realistic biomass and harvest options; discuss current, verified management options directly with CIBA or the professional.
Prevention: your practical checklist
- Obtain traceable postlarvae with a documented, appropriate EHP screening plan.
- Ask which pathogens any SPF (specific pathogen free for a stated list of pathogens) claim covers and maintain biosecurity after purchase.
- Keep nets, sampling trays, boots, and sludge tools assigned to individual ponds.
- Plan between-crop sediment removal and sanitation with a qualified professional.
- Use controlled water supplies and formulated feed; review live-feed risks with the hatchery.
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 EHP infection cause white faeces?
No. EHP and white faeces syndrome overlap in some cases, but neither observation establishes the other. Test shrimp and investigate other digestive problems.
Are management options changing?
Yes. CIBA reported field validation of an EHP therapeutic in May 2026. That institutional announcement is not a prescription or a guarantee for an individual pond. Ask CIBA or your professional about current evidence and suitability.
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 Enterocytozoon hepatopenaei — Technical Disease Card ↗World Organisation for Animal Health (WOAH); document header updated 30 September 2024
- Ecytonucleospora hepatopenaei n. gen. et comb. (Microsporidia: Enterocytozoonidae): A redescription of the Enterocytozoon hepatopenaei (Tourtip et al., 2009), a microsporidian infecting the widely cultivated shrimp Penaeus vannamei ↗Journal of Invertebrate Pathology; Wang et al., 2023
- A new and improved PCR detection method for Enterocytozoon hepatopenaei (EHP) based on a gene encoding a spore wall protein ↗NACA; Centex Shrimp technical note, 2016
- ICAR-CIBA sensitized the shrimp farmers of Ramanathapuram, Tamil Nadu about Microsporidiosis (EHP) and White Feces Syndrome (WFS), their prevention and management on 11th May, 2026 ↗ICAR–Central Institute of Brackishwater Aquaculture