Injured comb jellies can merge their bodies with other comb jellies, forming a giant hybrid sea creature with multiple buttholes and shared digestive and nervous systems. That's the latest discovery in a recently published scientific paper from Current Biology, written by a group of researchers from the University of Exeter in the UK and the National Institutes of Natural Sciences in Okazaki, Japan.
The mechanisms by which organisms recognize the 'self' from the 'non-self' remain poorly understood. […] Our results highlight two interesting phenomena. First, ctenophores may lack an allorecognition mechanism that prevents fusion events between conspecifics. Second, fused individuals rapidly integrate and share physiological functions and neurobehavioral outputs.
[…]
Our observations warrant further research into understanding the evolution of self–nonself recognition systems and the functional integration of neuronal structures in ctenophores.
Yep, we're going there. One of the co-authors of the paper even told Smithsonian Magazine that they performed some "Frankenstein pilot experiments" on the fused mechajellies:
In the lab, they cut off parts of sea walnuts' wing-like features, called lobes, and placed the invertebrates in pairs close together. Nine out of ten times, the jellies would fuse into one—and the mergers survived for at least three weeks.
When Jokura prodded one of these fused ctenophores, all of it twitched in response. That signaled to him the creatures had become one individual and now shared a nervous system. "What was surprising is that this quick response occurred simultaneously in both bodies, even though I had only touched one side," [Kei] Jokura, [a zoologist at the University of Exeter in England and the National Institutes of Natural Sciences in Japan] says to Science's Elizabeth Pennisi.
According to the researchers, the merging of the nervous system happened in about two hours.
In an interview with LiveScience, Jokura added that, "Watching the fused individuals swim, they truly appear as if they are functioning as a single organism, so it wouldn't be unreasonable to think of them that way."
Curiously, in appears that these hybrid jellies still don't technically qualify as "single organisms," because the DNA of each individual jelly remains separate, and thus they cannot reproduce as a singular hybrid creature. So that's…good news, I guess?
Previously:
• Why don't jellyfish sting each other?
