Sunday, July 26, 2009
Glowing in the Dark
Everyone has seen glow sticks or glow-in-the-dark stickers and posters or even lightning bugs. But did you know there are more than 50 species of plants and animals that glow?
Various jellyfish exhibit a phenomenon known as 'bioluminescence' - essentially glowing in various colors - as a means of defense. Plankton known as dinoflagelletes will emit light when threatened in order to attract larger predators that will eat the dinoflagelletes predator. Bioluminescence also occurs in railroad worms, pinecone fish, ping pong trees, and octopus. In bioluminescence, chemical energy is converted to light energy through an enzyme-catalyzed chemoluminescence reaction'. This means luciferase oxidizes the 'pigment luciferin (oxidation is the same process that is responsible for the rusting of metals through the loss of one or more electrons). Here's another video of various animals that glow through the process of bioluminescence.
Others, such as comb jellyfish, produce a rainbow through a different process of scattering light across it's moving 'combs' (cilia, or tails, which help in locomotion).
Amongst animals, the phenomenon is believed to 1) help frighten off predators when the animal feels threatened, 2) to camouflage the animal by blending with the surrounding levels of light, 3) or even to attract prey or a mate.
Plant life such as mushrooms and fungus are believed to have this quality to help attract pollinators.