The Glow-In-The-Dark Millipede

Hello. For my first post, I will be responding to an article about bioluminescence in a species of millipedes. Paul Marek and his team's work provide some of the first pieces of evidence about bioluminescence being used as a warning sign in certain species, based on their data collected in a ground experiment.

http://www.sciencedaily.com/releases/2011/09/110926131805.htm

Here are five facts that I learned from reading this interesting article.

1. Bioluminescence, present in fireflies and glowworms, is the ability to glow in the dark. For these organisms, it is thought that bioluminescence benefits them by attracting mates and even prey, by lighting up the surrounding environment so they can visualize their location and surroundings, and by passing messages along other members of a given species.

2. Motyxia are a genus, family, of cyanide-producing millipedes that live underground. Scientists hypothesized that they ooze toxic cyanide and other repulsive chemicals from small pores, in response to being disturbed. Millipedes that are above ground during the day display colors to anounce their defenses to any potential predators. For the Motyxia that come out during the dark nights, use bioluminescence for the same purpose (or at least it is hypothesized).

3. The rare glow-in-the-dark millipedes can only be found in three places in the world, all of which are in the state of California. To be more specific, The Santa Monica Mountains, the Tehachapi Mountains and the southern Sierra Nevada Mountains.

 4. The biochemical mechanism the millipedes use to activate the glowing, although unidentified thus far, is different than that of fireflies and glowworms. It is believed they have a photoprotein which is activated by calcium and energy-rich compounds in the cell.

 5. These millipedes use their glowing ability to defend themselves from the grasshopper mouse (Onychomys torridus), which are their most common predator. For an experiment conducted involving artificial and real millipedes that either had the glow or not, proves that the bioluminescence feature will successfully fend off the predators.

Mr. Marek's experiment which analyzed the reason for bioluminescence in certain millipedes, was performed validly and followed the scientific method. It is clear that he and his team attempted to answer the problem, why do some millipedes glow in the dark, in other words, for what purpose? His team gathered information about the Motyxia millipedes and other facts about bioluminescence in general. They then hypothesized that the bioluminescence feature was a defense mechanism for the millipedes that protected them from predators. To test their claim, they set up an experiment that tested the effectiveness of the glowing in protecting the millipedes from predators. Exactly 300 fake clay molded millipedes were created, half of which were painted with glow-in-the-dark paint, and the other half paint free. In addition, the team collected live Motyxia millipedes, and covered half of them with paint to cover up their glow. The four types of millipedes were combined and mixed randomly to avoid sampling bias, and strapped to the ground at the Giant Sequoia National Monument in California. The experiment ran one night only, and data was observed the next morning. It turns out that the millipedes who glowed had a higher chance of surviving. "Four times as many non-glowing millipedes showed evidence of attacks compared to their glowing peers. Similarly, in the clay group, non-luminescent models were attacked twice as often than those that emitted the glow." The data collected after evaluation, supported the team's original hypothesis. Lastly, they shared their findings to the science community. Marak and his team conducted their experiment with the scientific method, and can now claim their hypothesis to be valid.