More than 7,000 millipede species crawl across forest floors and garden beds around the world, pairs of legs pumping as they move through soil in search of food. While the term “millipede” translates to “a thousand feet,” the record number of millipede movers has been around 750 legs since the description of a Californian species in 2006.
The term “millipede” has been misused. A thousand meters? It’s a myth. Until now.
Eumillipes persephone is the scientific name for the “true” millipede. The new species was discovered in a borehole drilled as part of a mining operation in Western Australia, nearly 200 feet (60 meters) below the Earth’s surface. With 1,306 legs, it is the first millipede to live up to its multi-legged moniker. The spindly, brown crawler, named after Persephone, the Greek goddess of the underworld, is just over 3.7 inches long and about as thin as a USB cable. The millipede also lives much deeper in the soil than any previously known species, and its discovery is a story of great luck and incredible irony.
Bruno Buzatto, principal biologist at Bennelongia Environmental Consultants in Western Australia, was the first to see the Persephone millipede. The organization specializes in subterranean surveys of animal life and is frequently hired by mining companies looking to conduct environmental assessments while searching for resources. Mining companies drill the holes, which Buzatto describes as “portals” into the subterranean world.
Buzatto sends “traps” through the portals to determine what life lurks beneath our feet. He fills a plastic tube with a few holes in the side with leaf litter. He then drops it into one of the drill holes and abandons it. Life in the soil is drawn to the litter in the hopes of filling its stomach. When Buzatto retrieves the trap a month or two later, it is frequently teeming with life.
According to Buzatto, these traps regularly catch new creatures, some of which have never been seen before. “We pull up about 80 to 90 percent undescribed species,” he says. So it came as no surprise when, in August 2020, he came across an unusual animal he’d never seen before. Buzatto discovered an extremely long millipede in a haul taken from a hole in Western Australia’s Eastern Goldfields Province. “I realized it was a one-of-a-kind animal,” he says.
Buzatto had been reading a research paper about Illacme plenipes, a Californian millipede with the most legs in the world, a few years before. Paul Marek, an entomologist at Virginia Tech, was the study’s lead author. Buzatto sent him an email with a photo of his find attached.
Marek needed to see the specimens, examine them under a powerful microscope, and analyze their DNA to make it official. Buzatto shipped specimens to Marek’s lab in the United States in collaboration with the Western Australian Museum. The team was able to find and analyze five millipedes in total, with one female breaking the record for most legs (1,306) and a male falling just short of the mythical 1,000-leg mark at 998.
The Persephone millipede lives in a world with no light and, likely, limited food. It was designed by evolution to be unique in this world, similar to but distinct from Illacma plenipes.
Marek noticed many similarities between the Persephone and the Illacme plenipes, a millipede that lives halfway around the world, separated by the Pacific Ocean. It did, however, have some peculiar characteristics. “It was nothing like other family members,” Marek says.
For one thing, it lacked eyes, which is unusual in this order of animals. It was also unpigmented.
Both modifications make sense. Eyes aren’t all that important in the underworld. You do not need to be able to detect changes in the light. The Persephone, on the other hand, has massive antennae. Pigmentation loss occurs in a wide range of animals that live in dark places, such as caves, but the evolutionary pressures underlying pigmentation loss are still unknown.