Bumblebee queens have a survival trick that sounds impossible: They can apparently ride out a week underwater. A lab mishap at Ontario's University of Guelph led to the discovery, detailed in the Proceedings of the Royal Society B journal, after condensation flooded soil tubes holding common eastern bumblebee queens in a hibernation-like state—yet the queens lived. Follow-up experiments with more than 100 diapausing queens found they not only survived submersion for seven days, but they were actively taking in oxygen and releasing carbon dioxide while underwater, even as their metabolism had slowed by about 99%.
Researchers say the bees also tap into anaerobic respiration when submerged, an oxygen-free way of producing energy that humans use during intense activities like all-out sprints. How they're breathing is still unclear. Scientists suspect what's called a physical gill, a thin air layer around the bee that lets gases pass between water and insect body, plays a role. The adaptation may be widespread among the roughly 250 bumblebee species, whose ancestors evolved in cold, snowy environments where winter burrows often flood when the snow melts.
One biologist not involved with the study called the findings "remarkable," noting that they open up new paths to understanding where and how queen bumblebees survive the winter, per the New York Times. "Future studies manipulating water conditions and the likely physical gill, alongside detailed recovery analyses, will further clarify the adaptations enabling queens to withstand extended submersion," the researchers write, per ScienceAlert.