Fluorescence, not Bioluminescence!

Most of the time, photographing wildlife takes some sleuthing, and my latest expedition to photograph bioluminescent millipedes in the Genus Motyxia was no exception. These subsets of bioluminescent species are only found at certain altitudes in the Southern Sierra Nevada mountains, from Sequoia National Park/ Forrest, to the North of LA county.

Using a paper written by Paul Marek, the Sequoia National Forrest Guide book, and some taxonomic information, I set out with my friend Bertrand try and find the glowing critters.

Based on the literature, we had a loose elevation range to work within and used that in conjunction with the altitudes of campsites marked on the National Forrest guide to investigate several areas. We only had one day to find the animals, and one evening to photograph them. Ultimately, we were too late in the Spring season to find many millipedes at all, let alone bioluminescent ones. The current drought in California has also compounded the problem, making the Spring so much shorter.

However, while not all species flat backed millipedes are bioluminescent, the many of them are fluorescent. This means that they are all very good at absorbing specific wavelengths of light and then immediately emitting it at a slightly different wavelength (fluorescence). While only a selection of species within the genus can also make their own light (bioluminescence). The photos here are of the one live (non-bioluminescent) millipede that Bertrand found.

Bertrand, as it turned out, is not only a super ecologist by day but also an expert critter finder/wrangler by night. I on the other hand, only found a couple of dead ones. We were able to get these images by shining a small UV torch onto the subject, the light was re-emitted by the millipede in this bright electric blue. As for photographing the Bioluminescent species, I will just have to wait for next Spring and hope for more rain…

There are thousands of examples of fluorescence photography on the net, and unfortunately, it is all too often confused with bioluminescence and vice versa. Pages like this probably don’t help, as they contain the word bioluminescence alongside pictures of fluorescence, but then Google in all its algorithmic wisdom, can’t quite figure out that bioluminescence does not describe these photos. I do quite like them none-the-less and would like o show them to people. Steve Haddock talks about the difference between Bioluminescence, Fluorescence and Phosphorescence here, take a look if you’re still not too clear.