When we teach about arthropods, it can be difficult to illustrate that ALL of these animals have segmented bodies. When you’ve never seen an arthropod up close, it is a tricky idea to wrap your mind around. We often use use millipedes in our teaching as a great example of a fully segmented body on an animal. But now I have cool microscopes from Celestron, so I can show you what I’m talking about! I took all of the pictures shown in this post with the FlipView Portable digital microscope. It’s great for handheld shots where you need to be flexible with the angle of the scope. I deal with a lot of live bugs, so I need to shoot fast and not be held back by a big bulky set-up. The FlipView worked great!
In the picture above, you can clearly see the segments on this millipede. As these animals grow, they add segments and legs! When a millipede dies, the ring-like segments of exoskeleton are left behind.
This millipede was not happy about being photographed. She coiled up in a defensive stance and started to leak a noxious fluid from her repugnatorial glands located on the sides of her body. Millipedes leak this fluid to deter predators from eating them. In some species of millipede, the fluid contains cyanide compounds! Can you see the yellowish tinge on the exoskeleton in the above photo? That fluid tastes REALLY BAD. I have tasted it. I am a scientist. I am dedicated to my craft. Plus, I got sick of kids asking me what it tastes like, so I gathered some data. It is very bitter- a little like dirt juice or aspirin juice and the taste can linger on your tongue for many hours, even if you brush your teeth, drink mouthwash, eat Sriracha or suck on a Tootsie Pop. I do the hard work of you.
Almost every segment on a millipede has two pairs of legs. This is one of the ways you can tell them apart from centipedes, which have only one pair of legs per segment. However, when you’re poking around outside and you’ve rolled over a rock and want to know if that long thing is a venomous centipede (NOT Bug Chicks Approved for holding) vs. a poisonous millipede (TOTALLY Bug Chicks Approved for holding) (but not for licking- see above paragraph) you can’t really count the legs. So here’s the trick- centipedes move really fast in an S-shape. They are predators and run down their prey. Millipedes move kinda slow in a straight line after they come out of their defensive coil. They are decomposers that eat fungi and rotting stuff. They don’t need to move fast because mushrooms don’t run away.
Side Note: I’m really happy with the above shot. I just want to paint all of her little tarsal claws (millipede toenails)!
This shot perfectly illustrates the characteristic that all arthropods have jointed and segmented appendages. It can be almost impossible to distinguish features on millipede legs as they are moving, and I’ve never actually gotten to see all of the segments as clearly defined as in this shot! Millepede legs have seven segments each.
I was playing around with the menu settings on the FlipView and somehow managed to take this super cool shot. I have no idea what I did, but I’m thinking I will eventually do a whole series of shots in this style. This is one of the joys of giving myself time to really explore a new piece of equipment. The user’s manuals are great, but sometimes I like to just give myself some time and allow learning to take place while I’m making mistakes and testing the boundaries of a new toy!