The nature found an innovative way to achieve symmetry in this jellyfish species. Instead of growing new limbs in case of injured animals, the amputated jellyfish just reorganize their remaining limbs in a symmetric way, equally spaced out. This helps them to restore their ability to survive in the ocean.
For many other creatures of the sea, a more common way to deal with lost limbs is re-growing a new one. But when a "Gooeyness" jellyfish loses a limb, it rearranges the remaining ones in a way that ensures it can still swim properly and eat. A new study on the fairly rare method to deal with amputated limbs of the "Gooeyness" jellyfish has been published recently in Proceedings of the National Academy of Sciences.
Many marine enthusiasts might be excited because of this discovery, but this is also interesting for robotics engineers for a different reason. The experts in robotics can learn from the jellyfish's strategy for self-repair how to build robots that can heal themselves. Nature is an unlimited source of inspiration for mankind and its creations. This recent discovery is just another example of how we can inspire from the nature in finding the solution to a problem that challenged engineers in robotics for a long time.
The lead study author, Michael Abrahams, declared that the discovery happened almost by accident. The PhD student at California Institute of Technology, along with his advisor, an assistant professor of biology at Caltech, Lea Goentoro, had initially set out to study Turritopsis dohrnii. This is another intriguing enigma found in nature, a species of jellyfish that has achieved biological immortality by choosing to transform back into a polyp at any stage of its life. However, the research team found difficult to acquire these largely unstudied jellyfish, so the lab began experimenting with a different species, Aurelia aurita.
When during the experiments they amputated limbs from an anesthetized young jellyfish they were expecting the limbs to regrow. Instead, they were surprised to see something different happening. The young jellyfish rearranged its remaining limbs rather than regenerating them, as other species. Over the course of the only 18 hours the jellyfish achieved the performance to rearrange all its limbs until they were equally distributed around its body.
The animal recovered the ability to survive in the ocean by re-creating a semblance of its original symmetry. Michael Abrahams explains that this ability of the jellyfish to rearrange limbs into symmetric order is embedded in its body's "gooeyness". Elastic and squishy, when jellyfishes move, their tissue alternates between states of gooeyness and tautness, having fluid and elastic proprieties.
This discovery can provide interesting and inspiring ideas for the field of soft robotics. Soft robotics is a relatively new field that finds its inspiration from "soft" organisms like the worms, octopuses, and the jellyfish from the above study. Symmetrization may provide valuable insight to further research in the field of soft robotics and lead to ways of designing a greater freedom of movement in soft robots.
