Scientists in Japan have identified three species of sea worms, giving them the names of mythical demons because of their eerie glow.

In Japan, scientists have discovered three new species of uncommon glow-in-the-dark worms that bear a "striking similarity" to demons mentioned in legend.

The three newly discovered species, Polycirrus onibi, Polycirrus aoandon, and Polycirrus ikeguchii, are members of the bristle worm family of creatures that are often discovered in the shallow waters of Japanese rivers and streams. On March 29, researchers in the journal Royal Society Open Science published their findings.

The organisms emit a blue and purple luminous glow that makes them appear like hazy will-o'-the-wisps at night, the study authors speculate in their paper, suggesting that they may have served as an inspiration for traditional tales of Japanese demons, or "yokai."

Japanese folklore served as inspiration for the names. For instance, "onbi" (or demon fire) is a will-o'-the-wisp yokai that appears in lonely mountains and forests as a little, floating ball of light to mislead unwary travelers.

"Aoandon" is the embodiment of human fear, created from the horror of all the people who gathered to share ghost stories under the light of blue paper lanterns. According to tradition, as the tales were being told, the lanterns gradually went out, and in the fading pale blue light they cast, a demonic woman wearing a white kimono with sharp, blackened fangs, claws for hands, and horns emerging from beneath her long, dark hair appeared.

The only name that doesn't allude to Japanese folklore is "Ikeguchi." Instead, it pays tribute to the former aquarium director of Notojima who was instrumental in the worm's discovery.

The tentacles that emerge from the mouths of polycirrus worms, which allow them to sift through river mud in search of food, give them their name. The genus is a member of the polychaete family of bristle worms, which includes worms that date back at least 505 million years to the Cambrian epoch and have survived all five of Earth's mass extinction events.

Bristle worms, so named because of their rough, occasionally deadly bristles, have been found in almost every aquatic habitat, including next to hydrothermal vents on the ocean floor that reach temperatures of 140 degrees Fahrenheit (60 degrees Celsius).

The next step for the researchers is to determine how these recently found worms produce their ethereal glow.