If you study toxic jellyfish for a living, you know how to take safety precautions. You dive into the ocean covered in protective gear and know to avoid the venom-laced tentacles.
But there was one painful jellyfish encounter that always caught marine biologist Cheryl Ames by surprise. The Tohoku University-based researcher found that if she swam over the upside-down jellyfish — a species that does headstands on seagrass or mangrove forest floors — she’d start to feel a tingling, irritating sensation.
