03 May 2013

Millipede Fluorescence

Welcome back. How fortunate that, right after I release a blog post, Plants Fluoresce for Bugs, I come across an article about a bug that fluoresces. If you were spun up about carnivorous plants that glow, you’ll go wild about glowing bugs. And these aren’t just any bugs; these are (apologies to entomologists) creepy, crawly millipedes. The glowing carnivorous plants would love to get their tee..uh...love to catch arthropods like these.


This millipede probably doesn’t fluoresce.
(from www.wpclipart.com)

If you’re bothered by all those legs, relax. Baby millipedes have only a half dozen legs and most species don’t grow anywhere near even 400 legs. OK, that’s a lot, but they’re slow. The fast millipedes aren’t millipedes; they’re centipedes. Those millipede wannabes have only one pair of legs for each body segment. Millipedes have two pairs of legs. You’d think centipedes would be satisfied having longer legs and longer antennae.

And it’s not as if a millipede is going to attack you. They’re very docile. Scare them and they curl up. If things get really rough, they can ooze a rather toxic liquid or hydrogen cyanide gas through pores, but that stuff is only a mild irritant to most of us.

The fossil record suggests that millipedes are about the oldest land creature. You might guess that reproduction has played a role. What’s really cool about that is the foreplay. She millipedes coil up if he millipedes come on too quickly, so he has to work at it, rubbing away and maybe humming before she moans Yes! Yes! The rest is kind of graphically private.

Alcatraz Island Millipedes

I’d better get back to fluorescence. This news started on Alcatraz Island, site of the former federal prison, now part of the Golden Gate National Recreation Area, in California’s San Francisco Bay.

In an effort to census rats on the island, National Park Service personnel add a non-toxic fluorescent dye to bait that the rats consume and, of course, return to their surroundings. Since ultraviolet (UV) light causes the dye in the waste to fluoresce, a night-time search with UV lamps (i.e., black lights) provides a measure of the rat population.

In a recent survey by workers and volunteers, the black lights caused the rat waste to glow but so did millipedes. Entomologists at the University of California at Davis ruled out the possibility that the millipedes had sampled the spiked rat bait and determined that non-Alcatraz millipedes of the same species also fluoresced. That species is relatively common in the San Francisco Bay area; it’s just that no one was looking for them with a black light.

Wrap Up

In the overall scheme of things like evolution, it’s interesting to ponder why a nocturnally active millipede has a chemical in its exoskeleton that fluoresces in response to UV light, which you would expect to come from the sun.

While you’re at it, you might also ponder why millipedes of several other species in the same taxonomic family are bioluminescent. They don’t need UV light. They produce their own surprisingly bright white light. You probably missed my blog post on Puerto Rico’s Bioluminescent Bays. Anyway, these aren’t microscopic ocean plankton glowing; these are blind creepy, crawly millipedes.

Thanks for stopping by. You’ll love Tuesday’s photo addendum.


- Article on Alcatraz millipedes: http://www.ouramazingplanet.com/4291-glowing-millipedes-on-alcatraz.html
- More about the fluorescent millipedes (and scorpions): http://camastergardeners.ucdavis.edu/?blogtag=Alexander%20Nguyen&blogasset=46848
- Wikipedia review of millipedes: http://en.wikipedia.org/wiki/Millipede
- Millipede facts: http://www.toptenz.net/top-10-facts-about-millipedes.php#ixzz2PPZ7QsDw

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