Scientists accidentally find deep-sea 'jelly' creatures merged into 'single entity' after injury, revealing bizarre new behavior

A recent serendipitous discovery by scientists has unveiled a peculiar adaptive behavior in comb jellies, also known as ctenophores, which can merge into a single entity after being injured. This fascinating occurrence involves the fusion of their nervous systems and stomachs to create a singular, massive individual. This unusual adaptation, the first observed case of any species merging in this manner, was identified accidentally during experiments conducted in the laboratory.

Kei Jokura, the lead author and an evolutionary biologist, shared his excitement upon the discovery. During routine research on warty comb jellies (Mnemiopsis leidyi), commonly referred to as sea walnuts, Jokura and his team noticed missing jellies from a tank while another appeared unusually large. Detailed observation revealed it to be two distinct entities merged into one with no visible division.

To investigate this potential adaptation, researchers deliberately caused minor injuries to 20 pairs of jellies and found that nine successfully merged. This rapid fusion took place within 24 hours, with their neural systems rapidly synchronizing within two hours post-fusion. Tests showed that their stomachs functioned as one, with food introduced to one mouth appearing across the two joined stomachs.

Despite their collective behavior, these comb jellies cannot be classified as single organisms since they maintain separate DNA and cannot transmit these unique characteristics to their offspring. Still, they often behave in unison like a singular entity.

The researchers propose that this fusion behavior has remained largely unnoticed because its occurrence in natural settings is improbable. Injured jellies must be in proximity to merge—a rare scenario in the deep-sea environment. Additionally, comb jellies possess the ability to regenerate lost body parts and even reverse aging, making fusion less necessary for survival.

The initial study concluded with most fused specimens surviving beyond three weeks, limited only by funding constraints, suggesting potential longevity. Future research may reveal whether more than two jellies can merge simultaneously and plans are in progress to examine another species, Bolinopsis mikado, for similar capabilities.

Earlier, SSP wrote that scientists managed to replicate animal movements with striking accuracy.