Bizarre Worm With One Head and Countless Bodies Found in Astonishing Discovery

A strange new species of worm with one head and multiple, branching bodies has been discovered by researchers in Japan.

Confirmation of the new species of worm was announced by researchers led by professor Maria Teresa Aguado, from the University of Göttingen in Germany. Aguado was sent images of the strange worm by researchers in Japan and organized a field trip to examine and later confirm their findings.

The worms were found off Sado island in Japan, living inside host sponges in the seas surrounding the island.

They were found to be a form of syllid marine worm. Until now, only two others of this kind were known to exist.

The new species has been named Ramisyllis kingghidorahi after Japanese legend Godzilla's monster enemy King Ghidorahi, a kaiju that can regenerate lost body parts.

"Having the chance to dive and collect animals in the island of Sado was really remarkable. We were also quite lucky to find the animals the first day of diving," Aguado told Newsweek. "It was not until we finished the complete morphological and molecular study that we were sure. I was then quite enthusiastic and surprised, there were more species with such a tree-shape body!"

The team's findings were published January 19 in the journal Organisms Diversity & Evolution.

The authors suggested the strange form the worms take may be in response to the shapes of their host sponges. Their hypothesis is that the worm body branches out in strange ways to "explore" the insides of the host sponges.

"The ramified bodies of the branching syllids might mirror the intricated labyrinth of the sponge canal system in which they live, the sponge canal system, with the ability to produce new fully-developed segments allowing the worm to explore the canals," the study said.

Ramisyllis kingghidorahi worm, discovered in Japan
Images show the Ramisyllis kingghidorahi, a new species of branching worm discovered in the waters of Sado Island in Japan. The worms branching bodies may form in response to the shape of the host sponges they live inside. M T Aguado/University of Göttingen

Bizarre behaviour of the worms was also filmed by the scientists. In one clip, a Ramisyllis kingghidorahi is recorded "shaking" in an animated way that scientists believe is linked to the distribution of reproductive cells by the worm in its environment.

The first syllid marine worm species was discovered in the Philippines in 1879. The second was found north of Australia in 2012. Analysis suggests the Australian and newly described Japanese species share a common ancestor, which the researchers say is potentially where their asymmetrical branching bodies come from.

Aguado said many questions remain about these strange creatures: "Scientists don't yet understand the nature of the relationship between the branching worm and its host sponge: is it a symbiotic relationship where both creatures somehow benefit? And how do the worms manage to feed to maintain their huge bodies having just one tiny mouth in their single head?"

Update 01/28/21, 9:20 a.m ET: This article was updated to include quotes from Maria Teresa Aguado, and to include her first name.

The host sponge that the new worm species lives inside. Toru Miura