UHPLC-MS Tracks Jellyfish Venom Variation

Studying how venom changes based on an animal's environment is a fairly new area of research, and it has not been explored much in jellyfish and their relatives. That said, scientists have found in a handful of species that venom can shift depending on factors like water temperature, life stage, and location. In a joint study conducted by James Cook University and The University of Queensland (both in Australia), researchers looked at the extremely venomous Irukandji jellyfish (Carukia barnesi) and used ultrahigh-performance liquid chromatography-mass spectrometry (UHPLC-MS) to see whether its venom composition changes under different water temperatures (81°F, 84°F, and 88°F) and at two different life stages: as a young polyp and as a newly formed jellyfish (medusa). A paper based on their research was published in the journal Toxicon.¹

What Is Currently Known (or Unknown) About How Factors Like Temperature Influence Jellyfish Venom?

Jellyfish have tiny, microscopic stinging cells that inject venom into whatever they touch—whether that's prey or human skin. When certain small, nearly invisible box jellyfish sting people, it can trigger a condition called Irukandji syndrome, which causes intense, often excruciating pain. One of the most well-known and well-studied of these jellyfish, found in Northern Queensland, is Carukia barnesi. This jellyfish’s sting can cause a wide range of symptoms, from severe muscle pain, nausea, and vomiting to more serious complications like bleeding in the brain and even death in rare cases.^2,3

“However,” write the authors of the paper,¹ “it is not known what causes these variations in sting symptoms as differences in venom potency, geographic locations, temperature and sting source (bell versus tentacle) remain poorly understood.”

Scientists still know very little about how temperature affects the venom of jellyfish and their relatives, and this area has barely been studied. Only two studies so far have looked at how temperature affects the genes responsible for producing venom in these animals, and both found that sea anemones' venom-related genes could shift depending on both short-term and long-term temperature changes.^4-6

What Were the Key Findings Regarding Venom Differences Between Polyp and Medusa Stages, and the Influence of Temperature on Venom Composition?

The researchers found major differences between the venom of the polyp stage and the newly formed jellyfish stage, which was not all that surprising to them, as it was already known that this jellyfish's venom changes as the jellyfish itself ages. However, this is the first time anyone has shown that venom also changes between the polyp and jellyfish stages specifically. Since the stinging cells themselves change between these two stages, it makes sense that the venom would also change. These differences suggest that the polyp and jellyfish essentially live very different lifestyles, needing different venoms to hunt and defend themselves—which fits, since the polyp stays in one place while the jellyfish swims freely.¹

Before this study, no one knew whether water temperature could affect venom composition, so this is the first evidence showing that it can. That said, the way the venom changed with temperature was unpredictable and did not follow any consistent pattern, making it hard to pin the changes on any one specific cause. Because of this, the biggest contribution of this work is that it lays the groundwork for future research: it proves that temperature can influence venom composition, and now scientists can focus on figuring out exactly which molecules are changing and how that affects the venom's actual effects.¹

References

1. O'Hara, E.; Wilson, D.; Whan, J. et al. Too Hot, Too Cold or Just Right? The Influence of Environmental Temperature on the Venom of the Irukandji Jellyfish Carukia barnesi Across Two Life Stages. Toxicon 2026, 109305. DOI: 10.1016/j.toxicon.2026.109305
2. Barnes J. H. Cause and Effect in Irukandji Stingings. Med. J. Aust.1964, 1, 897-904. DOI: 10.5694/j.1326-5377.1964.tb114424.x
3. Fenner P.; Hadok J. Fatal Envenomation by Jellyfish Causing Irukandji Syndrome. Med. J. Aust.2002, 177, 362-363. DOI:10.5694/j.1326-5377.2002.tb04838.x
4. O’Hara, E.P.; Wilson D.; Seymour J. E. The Influence of Ecological Factors on Cnidarian Venoms. Toxicon X2021, 100067. DOI: 10.1016/j.toxcx.2021.100067
5. O’Hara, E.P.; Caldwell, G.S.; Bythell, J. Equistatin and Equinatoxin Gene Expression is Influenced by Environmental Temperature in the Sea Anemone Actinia equina. Toxicon2018, 153, 12-16. DOI: 10.1016/j.toxicon.2018.08.004
6. Sachkova M. Y.; Macrander, J.; Surm, J. M. et al. Some Like It Hot: Population-specific Adaptations in Venom Production to Abiotic Stressors in a Widely Distributed Cnidarian. BMC Biol.2020, 18, 121. DOI:10.1186/s12915-020-00855-8