This investigation is dedicated to Champion, a pink-foot millipede (Narceus americanus) who recently passed away under my care this fall. She originated in North Virginia, where I collected her at a size of about four inches. Late this November, she died in my terrarium in Princeton, NJ, halfway down one of the many tunnels she had maintained throughout her coir substrate. 
I haven’t had the time or knowledge to conduct an autopsy, but receiving a foldscope gave me an opportunity to inspect her environment in a little more detail. So let’s get into the investigation!

One of my suspects was the potential presence of pesticides in the fruit that I was feeding to Champion. While that’s obviously not something I can diagnose by eye, I thought it would be worthwhile to take a look at her final meal. Millipedes eat decaying plant matter, so I usually fed her a small piece of fruit. Here’s a piece of apple skin (the flesh had all been eaten off). 

The apple had a beautiful texture in the light, though it obviously couldn’t tell me much about Champion’s demise. In the center of the image you can see a more dark/dense area - I believe this reflects the wrinkles that form in the apple skin as it dries. 

Another suspect was parasites. I’ve heard that most millipedes have symbiotic relationships with mites, and Champion was no exception. During her life, I often saw small white mites crawling over her, seemingly matching the description of symbiotic mites described by other millipede owners…But for about a week of her life, I witnessed her repeatedly thrashing as the mites traversed her body. The behaviour stopped after a few days passed and I removed some excess mites with a swab. But the episode stood out to me - is it possible the mites were actually parasitizing her? 
I saw some similar white dots on her body, so I put them under the scope… 

But I couldn’t actually tell if they were animals! I could believe it by a stretch of the imagination, but it’s probably more likely these were specks of substrate. They were, after all, incredibly tiny! 
For comparison, I also examined some bits of the substrate. It wasn’t too dissimilar at all. 


After my failure to identify any mites, I decided to dig through the substrate for a bit more material. I found a stick covered in some green matter, which came off in my hands like crumbs. Based on the image, it seems possible that this was a type of mold or other non-animal organism. 

And finally, I discovered a shell-like object that resembled a plant or an elytra (both are a possibility - there was a layer of detritus in the terrarium that I had sterilized and added after collecting in my backyard). 

Up close, the shell had a veiny texture that to me evoked a leaf, suggesting this was plant matter. There was also a worm-like texture visible in the right side of this image - perhaps some type of larva that was killed inside of the plant? 

If Champion wasn’t four inches long, this is where I would try putting her under the microscope herself! But instead I’ll just add an image of her in life <3


So what did I learn? As expected, I didn’t glean much about the cause of death. But this did teach me about the difficulty of identifying organisms, even under a microscope. And, of course, I got to see a little bit of Champion’s world up close, the way she might have seen it herself. 

I conducted this project as part of Professor Pringle’s EEB321 class at Princeton University.