09/07/2016
Bioilluminence par excellence, from nature
Bioluminescence, from bio (life), and luminescence (light), means living light. It’s a natural light found in some animals and plants, especially in our oceans.
Bioluminescence seems to be everywhere – from glowing plankton in the shallowest water to unbelievably beautiful jellyfish. This allows fireflies to shine, makes waves glow at night, and powers deep-sea anglerfishs’ lure.
Bioluminescent creatures can glow, pulse, or flash, and not just white lights, but colored lights. Green and blue are probably the most common colors, but shades of pink, violet, yellow, and others have been seen as well. Red is the least common bioluminescent color, but it is used by some deep-sea creatures to great advantage, since few other marine animals can see it.
But what do bioluminescent creatures use their light for – to see in the dark? Perhaps, but also to attract prey, like anglerfish and sometimes to attract mates, and some use it to camouflage themselves and blend in with their surroundings. There is even speculation that some species of squid may use the rapid flashing of their many colors as a means of communication – talking to each other.
How they shine?
Chemicals (e.g. luciferins and luciferases from Latin word lucifer means "light-bringer") activate electrons in the animal’s body, the result of complex (and not always well understood) pathways involving stimuli, enzymes, and energy shifts. This amazing faculty manifests itself in thousands of species, including jellyfish.
Scientists estimate that about 1 in 2 of jellyfish are bioluminescent, including siphonophores (related to the dangerous Portuguese man-o-war), medusae, sea pens and other soft corals, and ctenophores (also known comb jellies).
Photos
Bio Bay, Puerto Rico and Toyama Beach, Japan
(Various sources)
http://www.sciencedirect.com/science/article/pii/S1873014006800214
http://www.pnas.org/content/47/8/1129.short
http://biolum.eemb.ucsb.edu/chem/detail2.html
http://www.bbc.com/earth/story/20160526-the-organisms-that-glow-brighter-than-any-other
