Gwyneth Perseveranda

Not all accidents result in tragedy; sometimes, they lead to groundbreaking discoveries, and this recent finding is a testament of that.

Photo Courtesy of Live Science.

A study reveals that deep-sea creatures known as comb jellies can fuse together when injured, forming a single organism with shared nervous systems and digestive tracts, enabling them to share foods.

According to the researchers, this occurrence is bizarre, due to the fact that it has never been seen before.

The fused jellies were accidentally discovered by the scientists, upon noticing that one of their test subjects was found missing from a tank in their laboratory.

The team then observed that one of the remaining jellies was unusually large and upon closer inspection, they realized that it was actually two individuals had fused together, with no visible distinction between them.

"I was very excited [when I found them]," said lead author of the study Kei Jokura, an evolutionary biologist at the University of Exeter in the U.K. and Japan's National Institutes of Natural Sciences in Okazaki.

"I immediately took the fused comb jellies from the room where I was keeping them and showed them to the other lab members," Jokura added.

Comb jellies, simple invertebrates from the Ctenophora family, are transparent and gelatinous, resembling jellyfish.

They create luminous displays in the deep sea through lighting up specialized cells throughout their transparent bodies.

The researchers suspected that the fusion of the comb jellies was a previously unknown adaptation triggered when the animals sustain an injury.

To test their theory, they removed small sections of the bodies from 20 bodies and placed them together by pairs.

It turned out that nine pairs have successfully fused together.

Further study showed that after 24 hours of merging, the two original bodies seamlessly became one with no apparent separation between them.

They also discovered that their nervous systems were fused, as the whole fused body reacted with a startle response when poked at one lobe.

"We were astonished to observe that mechanical stimulation applied to one side of the fused ctenophore resulted in a synchronized muscle contraction on the other side," Jokura said.

Fluorescent shrimps were fed to the fused jellies by the researchers, in order to test if their stomachs have also merged.

It turns out that the food ingested was seen moving across both stomachs, suggesting that this was the case.

However, the digested products were expelled from both anuses in an unsynchronised manner.

The researchers say that it is unclear whether the fusion of the two individuals function as a survival strategy and they suggested that future studies will fill the gaps in understanding, providing implications for regenerative studies.