An answer to WFS
Benchmark Genetics has published breakthrough findings on genetic resistance to disease in shrimp.
A scientific paper has set out new findings regarding genetic resistance to disease in Pacific white leg shrimp (L.vannamei).
The article, published in the Journal of Aquaculture, is based on research carried out by Benchmark Genetics into the parasite Enterocytozoon hepatorenal (EHP) and the related disease, white faeces syndrome (WFS).
Benchmark says its discovery of a genetic basis for resistance to this parasite opens the door to sustainable disease management solutions for shrimp farmers, offering the potential for enhanced productivity, profitability and environmental stewardship across the industry.
Shrimp aquaculture, essential to the global seafood supply chain, has been continuously challenged with infectious disease outbreaks that threaten production stability and, consequently, the economic security of farming communities worldwide. Co-infection of EHP and specific bacteria like Vibrio spp has been identified as a major contributor to WFS, leading to stunted shrimp growth and significant financial losses for farmers.
Benchmark Genetics’ research, conducted through a challenge test experiment on a population from its breeding programme in Colombia, demonstrates the feasibility of using genetic selection to enhance disease resistance in shrimp. Notably, the study identifies moderate heritability for resistance to co-infection, underscoring the potential for selective breeding to bolster shrimp health and resilience against these diseases.
Key findings from the study include:
• Moderate heritability for disease resistance: Results indicate that resistance to co-infection of EHP and WFS is moderately heritable, supporting selective breeding as a viable strategy.
• Compatibility with shrimp growth: Disease resistance and shrimp growth showed no significant negative genetic correlation, allowing for simultaneous improvements in both traits.
• Genomic selection advantage: Genomic selection, as opposed to traditional pedigree-based selection, proved more accurate and effective in predicting shrimp resistance.
• Complex genetic influence: The study reveals that resistance is influenced by multiple genes with small effects, validating the use of genomic selection.
Industry impact and environmental benefits
Benchmark Genetics says it has already implemented these findings in practice, applying genomic selection in its breeding programme to produce shrimp lines with improved resistance to co-infection by EHP and WFS.
The anticipated benefits are considerable:
• Economic savings: Disease-resistant shrimp will reduce economic losses and cut treatment and disease management costs, improving farmers’ overall profitability.
• Enhanced productivity: Farmers can expect healthier, faster-growing shrimp, bolstered by advanced genomic selection strategies.
• Long-term sustainability: Enhancing disease resistance through genetics will lead to more stable and resilient shrimp farming, reducing dependency on chemicals and antibiotics.
• Environmental stewardship: By decreasing the need for antibiotics and other treatments, these innovations align with the industry’s move toward more sustainable, eco-friendly farming practices.
Carlos Lozano, who leads the Shrimp & Tilapia Breeding Programme at Benchmark Genetics, said: “We are thrilled to share our research findings with the aquaculture community. This study reinforces our commitment to pioneering genetics-based solutions and highlights our dedication to enhancing both the economic and environmental sustainability of shrimp farming worldwide.”
The complete study, “The genetic basis of resistance to Enterocytozoon hepatopenaei (EHP) and White faeces syndrome (WFS) in the white leg shrimp (Litopenaeus vannamei)” is available in the Journal of Aquaculture and can be accessed at doi.org/10.1016/j.aquaculture.2024.741789
White faeces syndrome (WFS)
White faeces syndrome (WFS) is a disease affecting shrimp, particularly farmed shrimp such as Litopenaeus vannamei (Pacific white leg shrimp). It is characterised by the presence of white or pale-coloured faecal strings floating on the water’s surface or clinging to shrimp in grow-out ponds. This condition negatively impacts shrimp health, growth, and survival rates, often leading to economic losses in aquaculture.
WFS is a multi-factorial condition. It is primarily linked to gut health issues, often exacerbated by environmental, nutritional, and pathogenic factors, especially the parasite Enterocytozoon hepatopenaei or heptorenal (EHP) but also including Vibrio bacteria.
Environmental and nutritional factors, and immune suppression, can also play a part.
Clinical signs include:
• White faecal strings, often visible on the pond’s water surface.
• Reduced feeding: Affected shrimp exhibit decreased appetite and sluggishness.
• Soft or deformed exoskeletons.
• Mortalities: In severe cases, high mortality rates may occur.
• Discolouration and damage to the hepatopancreas (a critical digestive organ in shrimp).
Addressing WFS requires a holistic approach focusing on both prevention and mitigation of underlying causes to ensure sustainable shrimp aquaculture.
Management and prevention strategies include:
• Improve water quality: Regular monitoring and maintaining optimal levels of pH, dissolved oxygen, and nitrogen compounds.
• Use of probiotics: Adding probiotics to maintain gut health and control Vibrio populations.
• Feed management: Providing high-quality, balanced feeds and avoiding overfeeding to minimise waste accumulation.
• Preventing pathogens: Implementing biosecurity measures to prevent the introduction of pathogens. Treating or managing infections with targeted interventions, such as antifungal or antibacterial agents.
• Regular health checks: Monitoring shrimp for early signs of WFS to mitigate its spread.
• Managing stocking density: Avoid overcrowding to reduce stress and improve overall shrimp health.
You May Also Like
Sign up to our daily Newsletters
Permission Statement
Yes! I would like to be sent emails from Fish Farmer Magazine
I understand that my personal information will not be shared with any third parties, and will only be used to provide me with useful targeted articles as indicated.
I'm also aware that I can un-subscribe at any point either from each email notification or on My Account screen.
© 2025 Fish Farmer.