Researchers have discovered a new species of tarantula with a rare and “enchanting” coloration: Parts of its back, legs and mouthparts are an iridescent, electric blue-violet.
The spider, named Chilobrachys natanicharum, is the only tarantula ever found in a Thai mangrove forest. The team described the arachnid in a paper published last month in the journal ZooKeys.
“During our expedition, we walked in the evening and at night during low tide, managing to collect only two of them,” co-author Narin Chomphuphuang, a researcher at Khon Kaen University in Thailand, says in a statement. “These tarantulas inhabit hollow trees, and the difficulty of catching an electric-blue tarantula lies in the need to climb a tree and lure it out of a complex of hollows amid humid and slippery conditions.”
In addition to its coloration, C. natanicharum stands out among tarantulas because of its ability to live in both arboreal and terrestrial burrows in evergreen forests. The new research discovered the electric blue creatures live in mangroves, too, where they mostly stick to tree hollows because of the tides, per the statement.
While the spider was known before through the tarantula trade market, it had not been formally named, and scientists had not described its characteristics or habitat.
Blue is one of the rarest colors in nature—fewer than one in ten flowers are blue, and only about 4 percent of all 900 known tarantula species have a blue coloration, writes Liz Langley for National Geographic. In plants, color is achieved using pigments, which absorb most colors of light but appear as the one they reflect. However, no blue pigment exists in nature, so plants might mix pigments, add molecules or tweak their acidity to reflect this hue. But because blue and violet have the highest frequencies on the visible light spectrum and therefore contain the most energy, most plants’ leaves will absorb these colors rather than reflect that energy away.
Animals have a slightly different way of appearing blue—they rely on physics to produce a visual illusion known as iridescence, in which colors seem to change slightly when viewed from different angles.
“The secret behind the vivid blue coloration of our tarantula lies not in the presence of blue pigments, but rather in the unique structure of their hair, which incorporates nanostructures that manipulate light,” Chomphuphuang says in the statement.
In effect, the coloration is “mesmerizing,” he tells CNN’s Hafsa Khalil, and “reminiscent of electric blue sparks.”
Usually, animals have bright coloring to ward off predators, attract mates or camouflage themselves, per National Geographic. Because these spiders have elaborate mating rituals, it’s possible the color is meant to catch the eye of other tarantulas—and it’s already captured the attention of humans.
“We as humans are really attracted to rare, shiny colors,” Sebastian Echeverri, an independent arachnologist and science communicator who was not involved in the study, tells National Geographic. “So, we remember those species.”
Chilobrachys natanicharum was named after two executives from a Thai real estate developer, which won an auction to name the arachnid. All proceeds from the auction went toward the education of Lahu children in Thailand and to cancer patients, the authors write in their paper.
Unfortunately, the new tarantula species faces the same threats as other local populations: the destruction of natural habitats and tarantula hunting. In their paper, the authors conclude it is “crucial to conserve these species by protecting their natural habitats through the establishment of protected areas and implementing management plans for both the species and their habitats.”