1. Literally. Like pill bugs, Madagascar’s giant pill-millipedes protect themselves by rolling into a ball. The larger species may end up in a package the size of a tennis ball. But millipedes in the genus Sphaeromimus are a more manageable size, only up to an inch or two long.
2. It sings. Sphaeromimus millipedes have ridged music-making organs on their back ends. The male’s is called a “harp,” and the female’s is a “washboard.”
“Both sexes have a knob on the backside of the last leg pair which they rub across the ribs to produce sounds, like the [pick] of a guitar,” says Thomas Wesener, a curator at the Leibniz Institute for Animal Biodiversity in Bonn, Germany. He recently discovered seven new species of Sphaeromimus.
3. It responds to music it can’t hear. These millipedes have no ears that anyone has found. But they seem to recognize the vibrations made by other members of their species playing their bodily instruments. The music is used in courtship; males seem to play their harps to coax females out of their ball shape. Once the female is unrolled, they can get on with mating.
4. It stayed undercover for ages. For more than a century, all we knew of the genus Sphaeromimus was a single male bug collected in the late nineteenth century. Scientists thought it was a mistake—perhaps a mislabeled specimen of another species altogether. Then in 2005, Wesener and Petra Sierwald, a curator at the Field Museum in Chicago, described two new Sphaeromimus millipede species they’d found. (Along with, at last, some females of the original species.)
5. It lives in exclusive neighborhoods. In a new paper, Wesener and coauthors describe seven new Sphaeromimus species. They found three of them by sifting through museum collections, and the rest by searching in person in the jungles of southeastern Madagascar. Some of these species are “microendemics,” meaning that in the whole world, there’s only one tiny patch of land where they live. Each species may inhabit a forest fragment just a few hundred meters across.
6. It’s a star. Wesener writes that the local word for the giant pill-millipede, tainkintana, means “star dropping.” Other naturalists before him have defined it the same way. Malagasy dictionaries, though, define tainkintana as “falling star,” which is a little kinder to the millipede (though still mysterious).
7. It comes in fancy colors. Although most Sphaeromimus centipedes are the standard millipede brown or black, they’re occasionally seen with a reddish-black pattern, or even in pink.
8. One of its homes sounds like a setting in a fantasy novel. Though most of Wesener’s new species live in humid rainforests, one specimen turned up in a cave in a “spiny forest,” a dry ecosystem that’s as inhospitable as you’d guess from the name.
9. It’s unique. Genetic analysis showed Wesener that all the Sphaeromimus species separated from each other long ago. With their matching scaly suits of armor and multitudinous legs, they may look similar to an untrained millipede observer. But each species, tucked into its tiny bit of forest, is one-of-a-kind.
10. There might be more (for now). “In my 2007 expedition we collected in every single remaining forest in the very [southeast]” part of Madagascar, Wesener says. But the genus also exists 300 kilometers to the north, where no one has done a thorough inventory yet. “There are possibly other species to be found.”
Their pocket-sized habitats, though, mean these millipedes are easy to wipe out. One of the habitats Wesener found is already cut in half by a road. Others are threatened by a large titanium-ore strip mining project. That’s something the millipedes won’t find very ballin’ at all.
Image: Sphaeromimus andrahomana by Wesener et al.
Wesener, T., Le, D., & Loria, S. (2014). Integrative revision of the giant pill-millipede genus Sphaeromimus from Madagascar, with the description of seven new species (Diplopoda, Sphaerotheriida, Arthrosphaeridae) ZooKeys, 414, 67-107 DOI: 10.3897/zookeys.414.7730