Meet the newest species of tarantula. It’s electric blue.

Between the sky and sea, nature appears to favor blue, as do we humans.

Yet the color is rare in nature—especially not in “a blue-violet hue resembling the color of electrical sparks,” which is how a research team described a new species of tarantula in southern Thailand. The spider, which can measure nearly three inches long, sports iridescent streaks of neon color on its legs, back, and mouthparts.

The spider, named Chilobrachys natanicharum, was already known in the pet trade as the electric blue tarantula, but a recent study published in the journal Zookeys finally confirmed it as a unique species.

Of the 900 known tarantula species, only about four percent have any blue coloring, says Sarah J. Kariko, an arachnologist at Harvard University. (Learn why science still can’t explain blue tarantulas.)

Though pigments form other colors in animals, such as red and yellow, the process is different with blue. When hit by light, nanostructures in the cells reflect a blue color back to our eyes, says Kariko, who wasn’t involved in the new study.

Such structural colors often create iridescence, says Ling Li, an associate professor at Virginia Tech who collaborates with Kariko in studying spider colors.

“It’s like a peacock feather. If you change your angle the color will change a little bit,” while colors made from pigment don’t change with the angle of your view.

A rare forest find

The tarantula is also the first ever discovered in a mangrove forest in Thailand, study leader Narin Chomphuphuang, an arachnologist at Khon Kaen University in Thailand, says via email.

For the study, Chomphuhuang and colleagues went on an expedition to the mangroves of Phang-Nga Province, searching at night in the humid, muddy vegetation for a tarantula’s telltale sign: Shroud-like webs covering its burrow. (Watch a tarantula crawl out of its own skeleton.) 

In this case, the team spotted a blue tarantula in the hollow of a tree, which they had to climb to lure the animal out. Another expedition revealed the spider living in evergreen trees, a separate ecosystem.

“We are amazed to discover that they can also thrive in highland evergreen forests. This spider's incredible adaptation is fascinating.”

Back in the lab, the scientists compared the tarantula’s DNA and physical characteristics to similar species and pinpointed key differences, including their coloring.

The tarantula's name, C. natanicharum, refers to Natakorn Changrew and Nichada Changrew, two executives at Thai real estate developer Nichada Properties Co, Ltd., which won an auction to name the spider. Proceeds will go to support healthcare and education for the Lahu, an Indigenous group in southern Thailand.

Why so blue?

It’s likely that the tarantula's main ancestor had some blue, or could produce blue nanostructures, says Sebastian Echeverri, an independent arachnologist and science communicator based in Pittsburgh.

Echeverri notes a 2020 study that showed green and blue have evolved numerous times independently in tarantulas, suggesting the colors occupy a crucial role in their lives.

As general rule, many animals evolve usually bright colors to warn off predators, camouflage themselves, or attract mates.

For instance, it’s possible the newfound tarantula’s colors are involved in mating, Kariko says, as the large spiders have dynamic courtship rituals. (Get a mesmerizing look at nature’s eight-legged wonders.)

Tarantulas lack sharp color vision, but these colors are so bright, “it’s pretty reasonable to say this is something meant to be seen,” Echeverri says.

For instance, the startling blues on the appendages in front of the tarantula’s mouth may deter predators by saying: “Look at me! I have big fangs! Don’t step over here!”

Whatever the reason, the new tarantula will likely continue to be a favorite.

“We as humans are really attracted to rare, shiny colors,” Echeverri says, “so we remember those species.”