Researchers from Nagoya University, located in central Japan, have discovered three new species of bioluminescent marine worms. Bioluminescence is a natural chemistry treasure that causes organisms to emit light as part of their natural behavior, although biologists are still trying to discover what function it serves in their development.
Bioluminescence is present in various animals and organisms in nature. Fireflies, for example, use it as a form of social communication and it is an important key to mating. But they are not the only living beings capable of transforming the chemistry of their bodies into luminous energy; it is estimated that there are over 7,000 species of bioluminescent organisms in the world. The ineffable chemistry that produces light is also present in less complex beings such as plankton and some polychaete worms, although very little is known about the latter.
It Was Not Just One, but Three Different Species of Worms
A group of researchers from Nagoya University found three different previously unknown species of bioluminescent worms. The team found these chemically active creatures in different parts of Japan, and although they initially thought they were the same species, a more thorough analysis revealed that they were separate species.
Normally, polychaete worms inhabit shallow waters, but they are nocturnally active, making them difficult to identify. But when observed, the spectacle is simply amazing: they appear like underwater shooting stars emitting violet-blue electric pulses. A video published by Phys.org shows the worms’ activity underwater and can be viewed in the box below.
Naoto Jimi, co-author of the research, said that at the time of the discovery of the new species, they were surprised and felt a duty to document them as very little is known about bioluminescent polychaete worms. “Our previous research on the luminescence of the Polycirrus genus had established it as a valuable topic for bioluminescence studies,” said Jimi. “However, we later discovered that what we thought was a single species of Polycirrus was actually three different species.”
The three new species of bioluminescent worms were named after Japanese folklore and their violet-blue coloring emitted through chemical reactions in the organisms. Polycirrus onibi, Polycirrus aoandon, and Polycirrus ikeguchii were the names chosen by the research team, two of which are yokai names, while the last is the surname of an important Japanese biologist.
In ancient Japanese tradition, “onibi” (demonic fire) is a type of will-o’-the-wisp yokai in the form of a small floating ball of light that is believed to mislead travelers high up in the mountains and forests. Meanwhile, “aoandon” (blue lantern) is a ghostly yokai that materializes in the form of a woman wearing a white kimono with horns and sharp teeth. According to Japanese beliefs, Aoandon pursues lanterns in homes to turn them into unnaturally blue light. Finally, Polycirrus ikeguchii was named after Shinichiro Ikeguchi, a former director of the Notojima Aquarium and an important Japanese biologist.
Understanding the mechanisms of bioluminescence present in polychaete worms contributes to medical and life sciences research. Bioluminescence is a chemistry treasure that shows us that natural processes are not simple despite being very small beings.
Story originally written in Spanish by Alejandra Martínez in Ecoosfera.