THun (tuna) fish and dolphins, but also some species of squid, can travel very quickly thanks to their streamlined body. Jellyfish are not among the fastest swimmers. But in terms of energy efficiency, these cnidarians, which have populated the oceans for 500 million years, outperform all other sea creatures.
Jellyfish don’t just drift passively with the current. Equipped with a kind of recoil drive, they can also move actively. However, the muscles that then become active only consist of a single layer of cells and make up barely one percent of the body. Fish, on the other hand, often consist of more than fifty percent muscle mass.
However, jellyfish move faster than their weak strength suggests. Because while your muscles relax after the contraction and your elastic body takes on its original shape again, an additional thrust is created. Scientists working with Brad J. Gemmell from the Marine Biological Laboratory in Woods Hole, Massachusetts, report that a ring-shaped water vortex is involved Proceedings of the American National Academy of Science. Meanwhile doing research at the University of South Florida in Tampa, Gemmell discovered together with Sean P. Colin from Woods Hole and Kelly R. Sutherland from the University of Oregon in Eugene that jellyfish are far more tricky than initially thought: They can pick up speed even during the contraction phase of their movement cycle. Read more …
Caption: Jellyfish, photographed in a glass basin. Credit: Bild: University of South Florida