There’s an unexpected twist in this jellyfish tale …
Photographer Victor Devalles was snorkelling off the coast of Spain recently when he captured this short clip of a jellyfish unwittingly trapped in a 15-second spin after straying too close to an air-filled bubble ring.
Devalles was, in fact, responsible for creating the bubble ring, though he never intended to send the jelly into a high-speed whirl. "I was trying to make a video of the jellyfish swimming through the bubble ring,” he explained to the Daily Mirror. Instead, it touched the edge of the ring and was sucked into a dizzying spin.
Bubble rings are a kind of vortex and divers can create them by exhaling air in a certain way while facing the surface of the water (more here if you’re keen to try it out). If the bubble of air is big enough it can form a donut-shaped ring that grows in size as it floats towards the surface. “The water pressure at the bottom of the bubble is greater than at the top, so the pressure pushes the air up faster,” Tessa Koumoundouros explains for Science Alert. “This squeezes the bubble until the bottom meets the top and punches a hole through the middle, where water flows through.”
The water circles around the air bubble forming a ring of vortices:
The buoyant rings become more stable the faster the vortices spin and they can make it all the way to the surface if left undisturbed. If, however, an unsuspecting jelly slams into one, then all of that circular energy can funnel into the animal in dramatic fashion.
Fortunately the jelly appeared uninjured after the spin, according to Devalles. It’s likely that jellyfish are accustomed to turbulent currents. Research indicates that they are fairly adept at reorienting themselves if they do get swept off course and will swim against the current if they feel they are losing their way.
As for dizziness, let’s hope they don’t experience it like we do.
Top header image: Geoffrey Gilmour-Taylor, Flickr