14 DAY TRIAL // Now many stare in amazement when they get the chance to see a moon jellyfish swimming around the ocean but, as it turns out, maybe they should.
Researcher Brad Gemmell with the Marine Biological Laboratory in Woods Hole, Massachusetts say that, after spending some time studying these creatures, he found that they are by far the world's most efficient swimmers.
What Brad Gemmell means is that, when compared to all other animals that live in the ocean and when also taking into account its mass, this jellyfish species uses the least energy to travel over a given distance.
“When moon jellyfish contract their umbrella-shaped bells, they create two vortex rings — doughnuts of water that are continuously rolling into themselves. The creature sheds the first ring in its wake, propelling itself forward,” Nature explains.
Furthermore, “As the bell relaxes, the second vortex ring rolls under it and starts to spin faster. This sucks in water, which pushes up against the centre of the jellyfish and gives it a secondary boost.”
Seeing how the moon jellyfish's bell relaxes automatically, the creature gets to travel 80% farther without burning any energy.