Moon jellyfish have a self-repairing mechanism but it’s not necessarily what you might expect. Rather than regenerate lost limbs like other animals such as lizards do, jellyfish prefer to cope with their loss by rearranging their remaining body so that it stays symmetrical.
Michael Abrams, one of the main researchers working on the project and a graduate student in biological engineering and biology at the California Institute of Technology (CalTech), gave a statement saying that this is a never-before-seen approach at self-healing.
Abrams spoke to Live Science, stressing how unusual the feature truly is, saying that the newly observed self-repair mechanism pretty much broadens the definition previously associated with the term “self-repair”.
He went on to explain how exactly the jellyfish fix themselves: “What we found was that they rely on the mechanical forces generated by their own propulsion machinery, [which is] their muscle and the viscoelasticity of their jelly material”.
The researchers strongly believe that this is one of the main features which helps moon jellyfish survive natural predators in the wild. It’s a well known fact in the scientific community that sea turtles in particular enjoy the taste of jellyfish, and a study in the journal Integrative and Comparative Biology, in 2010, revealed that a third or more of marine invertebrates are being constantly hurt.
The discovery of the mechanism was surreal and unexpected. What Abrams and his co-author, Lea Goentoro, a biology professor at CalTech, really wanted to do was study immortal jellyfish and try to understand how the species can revert from adulthood into an immature polyp stage. It’s a fascinating mechanism as it allows them to live indefinitely and could provide answers to several human diseases if cracked by experts.
However the shipment of immortal jellyfish was taking too long to reach the duo and Abrams got impatient. He wanted to start practicing jellyfish husbandry sooner rather than later, so he ordered another shipment of moon jellyfish.
He anesthetized and amputated a few specimens, and noticed that just a few hours after losing a limb, the creatures would start to rotate their remaining ones around their bodies in order to regain the lost symmetry.
When a moon jellyfish had four (4) limbs cut off on the same side, it took about four (4) days to move its remaining limb around so that it became fully symmetrical again. The only difference would be that each side would have half as many limbs as before.
Abrams and Goentoro ended up looking at roughly 500 jellyfish belonging to four (4) different species. Depending on the severity of their loss, somewhere between 72 percent (73%) and 96 percent (96%) of the creatures successfully managed to become symmetrical again.
The initial working theory was that jellyfish either grew new cells that helped them push the remaining limbs away from each other and keep even spaces between them, or kill off cells in order to bring the limbs closer together. Test however proved that the theory was wrong.
The researchers then anesthetized the jellyfish enough that they’d find it hard to move. It was then that the duo realized that a jellyfish’s regular pulsations cause specific muscular movements that move the limb around the creature’s body.
Image Source: sciencedaily.com