For the first time, scientists have found a millipede that actually has 1,000 legs. More than 1,000, actually: Plucked from deep in a mine in Western Australia, Eumillipes persephone has an eye-popping 1,306 legs along its 3.78-inch frame.
The newly discovered millipede is an example of superelongation, when the animals comprise more than 180 segments; E. persephone has 330 segments. Living so deep in the Earth, the animal has no need for eyes, but it does have long antennae and a beak for feeding. Details of its discovery were published today in Scientific Reports.
“This thing is like 60 meters underground, in the dark,” said Paul Marek, an entomologist at Virginia Tech and lead author of the new paper, in a phone call. “It’s just mind-boggling to consider. There must be an orientation to food and resources, and how to find other mates,” he said, noting that “the sensory structures seem to be very highly developed in this particular species.”
Its first name means “true thousand feet” — take note, other millipedes — and its second name comes from Persephone, the queen of the underworld in Greek mythology. The previous record-holder for millipedes was found in California in 2006, but that species had only 750 legs. “Their name has always been kind of a misnomer,” Marek said. “All [previous] millipedes are virtual millipedes in the true sense.”
Millipedes grow new legs over the course of their lives, so even the 1,306-record currently held by one female E. persephone could be usurped in the future. Now that one millipede species has actually met the thousand-leg threshold, perhaps more will follow.
For now, though, E. persephone is the leggiest animal on the planet. Each leg is short, used to help the animal tunnel through soil. The animal also has chemical defences; over 100 glands along its body secrete an alkaloid toxin that Marek said is probably used to deter predators like ants, beetles, and moles. There are none of these glands on the millipede’s rear-end, because the animals sometimes take in water by everting their rectums. You wouldn’t want to accidentally drink the toxin you’re secreting.
The stringy arthropod was found nearly 60.96 m underground in a drill hole, in Australian gold and tin territory; the researchers managed to lure the animal out by lowering a cup filled with leaf litter on a string, leaving it there for weeks. When they finally hauled it up, they put the leaf litter under a lamp, with a funnel below. The heat from the lamp drove the still-living arthropods through the funnel to be inspected by the scientists.
Marek counted the legs manually, with a bit of maths to account for some segments that have a different number of legs. It’s “something best done with a marker,” he said, so you don’t lose your place along the creature.
Since the millipede lives underground in mining territory, it is in danger. Because fewer than 10 individuals are yet known to science, it’s hard to say just how many E. persephone are out there.
“The reason I do research is for understanding planetary biodiversity, and preventing something called an anonymous extinction, where a species goes extinct without knowing anything about it,” Marek said. “I hope we can learn more about these and conserve their habitat.”
The newly discovered species has many legs to stand on, but ultimately, its survival may depend on the the actions of humankind.