The Effects of Jellyfish on Swimming

We know that jellyfish were some of the first animals to swim. More than 200 million years ago, they've survived mass extinction events. For a long time, it's been thought that there must be something about their ability to move efficiently that's allowed them to survive for so long in the oceans. The body shape of these jellies creates what are called vortex rings. Each time the animal contracts its muscles, it creates this donut of water. And it almost pushes off of that donut of swirling water to move through the water without having to use a lot of energy in the process.