In a surprising discovery, marine biologists have observed comb jellies, specifically Mnemiopsis leidyi, demonstrating an ability to fuse their bodies, integrating both nervous and digestive systems into a single functional unit. This phenomenon, documented in a recent study, challenges traditional understandings of biological individuality and self-recognition mechanisms.
The initial observation occurred when biologist Kei Jokura identified a seemingly merged pair of comb jellies in a lab at Woods Hole Oceanographic Institution. Intrigued, Jokura and his colleague, Mariana Rodriguez-Santiago, initiated experiments to recreate this fusion.
Their research revealed that not only could the comb jellies fuse physically, but their internal systems also merged seamlessly. When one part of the fused jelly was gently prodded, the entire organism reacted, suggesting a shared nervous system. Further investigation showed that the jellies' digestive systems also merged, allowing food to be processed and shared across the fused unit.
These findings, published in Current Biology, introduce significant questions regarding the genetic mechanisms facilitating fusion and how neural signals are integrated within the merged entity. Such biological flexibility is rare in the animal kingdom, highlighting the unique nature of comb jellies.
Comb jellies, or ctenophores, are an ancient lineage, possibly among the earliest animals to have evolved. Their simple nervous systems and lack of a stinging mechanism make them ideal for studying fundamental aspects of animal biology. Additionally, a separate recent study has noted the comb jellies' ability to regress to earlier life stages under stress, showcasing their developmental adaptability.
These investigations could potentially advance our knowledge of how allorecognition, the ability of an organism to distinguish between its own and foreign tissues, developed in the animal kingdom. Future studies will aim to further unravel the intricacies of these simple organisms and their unique biological mechanisms.
Jokura's continued research is expected to focus on how the jellies' nervous systems integrate post-fusion. He aims to explore the possibility of "fused consciousness" within these organisms by visualizing their integrated neural networks.
