A groundbreaking study from Connecticut College has revealed that chemical byproducts produced by the deadly amphibian fungus Batrachochytrium dendrobatidis (Bd) may unexpectedly improve survival rates in ghost shrimp (Palaemonetes paludosus). The findings, published in the peer-reviewed journal PeerJ, shed new light on how fungal metabolites impact freshwater invertebrates beyond amphibians.
What is Bd and Why Does It Matter?
Bd is a chytrid fungus responsible for devastating amphibian populations worldwide. Scientists are exploring its metabolites as a potential prophylactic treatment to help amphibians resist infection. However, before such measures are implemented, it’s crucial to understand their effects on other species sharing the same ecosystems.
The Connecticut College Experiment
Led by Ellisa Carla Parker-Athill and Taegan McMahon, researchers conducted a controlled laboratory study comparing ghost shrimp exposed to:
- Artificial spring water (control group)
- Filtered Bd metabolite solution (test group)
Over two weeks, they monitored heart rate, behavior, and survival of the shrimp.
Key Findings
- 48% Lower Mortality – Shrimp exposed to Bd metabolites survived significantly longer than the control group.
- Behavioral Changes – Treated shrimp had slower heart rates and showed less evasive movement, potentially making them more vulnerable to predators in natural habitats.
- No Tissue Damage – Microscopic examination revealed no gill damage or visible stress symptoms at the tested dose.
“Our goal was to understand whether these fungal byproducts—currently being studied for amphibian protection—could have unintended effects on other freshwater organisms,” said Parker-Athill.
Ecological Importance of Ghost Shrimp
Ghost shrimp play a vital role in freshwater ecosystems by cycling nutrients and supporting biodiversity. Any change in their survival or behavior could have ripple effects throughout the food web.
Challenging Previous Assumptions
While Bd is deadly to amphibians, this study suggests that at low doses, its metabolites might actually benefit certain non-amphibian species. However, altered behavior patterns raise ecological questions that warrant further research before conservation strategies using Bd metabolites are implemented.
“These results may seem counterintuitive given the fungus’s deadly impact on amphibians,” said McMahon. “But they open the door for exploring both the benefits and potential trade-offs of Bd metabolites in conservation work.”
Why This Matters for Conservation
Past research has focused almost entirely on amphibians. This study emphasizes the need to evaluate cross-species impacts of fungal pathogens and their byproducts—especially when considering large-scale environmental applications.
📄 Reference:
Parker-Athill, E.C., McMahon, T., et al. Exposure to Batrachochytrium dendrobatidis metabolites altered ghost shrimp behavior and reduced mortality. PeerJ (2025). DOI: 10.7717/peerj.19815