How does millipede reproduce

A Pseudopolydesmus vulva, under UV light. There are over 13, different species of millipedes known to science with many more discovered every year , and they each have their own unique way of mating.

The genus that Sierwald and her colleagues focused on in this study, Pseudopolydesmus , is made up of half-inch-long brown millipedes from North America. Not Pseudopolydesmus , though. It started out when I found a pair of this genus, a male and female, in copula, sort of attached. To solve this problem, Sierwald and her colleague, Field Museum co-author Stephanie Ware, experimented with different lighting and imaging techniques. Once digested, millipedes leave their waste or droppings along the forest floor.

This excrement is full of helpful nutrients and acts as new soil for the environment. This particular species of millipede is nocturnal, meaning they come out to forage for food and explore the forest at night.

They will crawl along the rainforest floor looking for decomposing material to feed on. The giant African millipedes will also spend this time burrowing into a safe place to rest during daylight hours. Communication between millipedes is important! Giant African millipedes have poor eyesight, so their sense of touch seems to play an important role.

They can feel with their antennae and their legs, and could possibly communicate by scent as well. This particular species of millipede is not known to vocalize or make sound; unless of course you count the sound of hundreds of legs moving across the forest floor.

Reproducing and creating more millipedes is an important part of life in the rainforest. When the time comes to reproduce, a male giant African millipede will wind around a female millipede. A few weeks later, the female will lay hundreds of eggs in a hole in the ground.

After about three months, those eggs will hatch, producing a large group of baby millipedes! In most millipedes, including Pseudopolydesmus , the male's testes are located in the body starting behind his second pair of legs.

But his gonopods, the specialized pair of legs used to insert sperm into the female, are way back on his legs of the seventh body ring. Once the male has gotten his gonopods covered in blue ejaculate, he's ready to insert them into a female's vulvae. The microscopic images showed the tiny fleshy part of the male's gonopods that actually enter the vulvae. Tiny claws on the end part of the male gonopod hook behind ridges on the female vulva.

After mating, the female's vulvae get sealed up with a gooey secretion, trapping the sperm inside. Later, when she lays her eggs, they get coated with the stored sperm on their way out of her body. The new imaging in this study also helps show how that process works. I always thought it came from the male, because I thought the male wanted to seal off the female so that she couldn't mate again," says Sierwald.

I don't know whether that is her way of protecting her vulvae or preserving the sperm. Those are interesting fields for further study. In addition to giving us a better understanding of the mechanics of millipede sex, Sierwald hopes the project will enable scientists to better understand the relationships between different millipede species, which could shed light on how they evolved.

As mountain ranges and rivers formed, groups of millipedes would get cut off from each other and develop into new species. After a pair of millipedes started getting it on, researchers from the Field Museum of Natural History in Chicago scanned both individuals and one male-female pair in an electron microscope.

They also captured dozens of photos at slightly varying angles on a digital camera. By layering them digitally, they were able to clarify tiny genital details. They photographed the millipedes in both natural and ultraviolet lights, since their genitals glow under UV lighting. Over at UC Davis, collaborating scientists placed individual millipedes into test tubes and ran micro-CT scans, which captured and layered a series of X-ray images to visualize the bugs in 3D without the need for any dissection.