A reader just sent us this amazing photograph she took:
The specimen curled up when she picked it up. She wants to know what it is. The creature is segmented, and each pale green segment has a black marking on it. What an interesting looking organism!
Our reader holds in her hand a pill millipede! Pill millipedes are members of the Superorder Oniscomorpha. The name is very similar to that of another creature: Oniscidea, which is commonly known as a roly-poly. Roly-polies and pill millipedes look a lot alike, especially when they curl up like the one in this photo. However, despite their similar appearances, pill millipedes and roly-polies are not related.
Like other millipedes, pill millipedes are arthropods and have two pairs of legs per segment. But unlike other millipedes, Pill millipedes have 11-13 total segments, making them much shorter. However, their length (or lack thereof) allows them to curl up completely into a ball when they are disturbed. Most other millipedes also curl up when bothered, but into a C-shape, not into a ball. Pill millipedes also exude a noxious liquid, which is caustic and toxic, as a defense mechanism. The optimal environment for a pill millipede is in the debris of a forest floor. This dark, damp environment is full of the decaying plant matter that the arthropods eat.
We don’t know the species of this green and black pill millipede. There are over 12,000 species of millipedes, which include all of the different species of pill millipedes. If any of our readers recognize this the species ball-shaped specimen, we invite them to share their knowledge in the comment section of this post!
To sum up, one of our readers shared a beautiful photo of a pill millipede in her hand. We identified it by its segmented body, and the curling-up behavior that millipedes adopt for defensive purposes.
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