What is biofluorescence?
Biofluorescene is a trait of an organism (any living thing) where light that hits the organism is re-emitted at a longer wavelength. When you stand under a blacklight at a bowling alley or in a haunted house and your white shirt and shoe laces glow bright, that is fluorescence. When you see this in an animal, it is call biofluorescence. To understand biofluorescence, we must understand the difference between biofluorescence and bioluminescence.
The Science of Biofluorescence
Biofluorescence is a great example of how all three main sciences interact. This makes biofluorescence an ideal tool for teaching and learning about science. Let's examine the biological, chemical, and physical properties of biofluorescence.
Biology
Biofluorescence has been examined in a range of species including insects, plants, fish, reptiles, and amphibians. Fluorescence has been found to act in sexual attraction (bees and flowers, birds, spiders), intraspecies recognition (copepods), camouflage (reef fishes), and signals of condition (leaves, fruits, mammals).
Here are a few organisms that fluoresce; watch the image below to see the reveal of their biofluorescence.
What do you notice about the differences in how each organism "glows?" Why might these differences exist?
Chemistry
Biofluorescence is the result of natural fluorophores (chemicals that fluoresce). There are many natural fluorophores, all organic chemicals with their own fluorescent emission wavelength.
Here are a few examples of some of the chemicals underlying the fluorescence we see in living organisms.
What similarities and differences exist between the structures of the fluorophores?
Do you recognize any of the names? Where have you heard them before?
Physics
Biofluorescence is the result of absorbed light being re-emitted at a longer wavelength due to fluorophores. The wavelength of light determines if we can see it and what color it appears as. Fluorescence shifts this wavelength to a new color.
Here the wavelengths of light visible to humans are labeled. Some organisms can also see wavelengths in the ultraviolet range.
Which aspect of biolfuorescence is your favorite? The interaction of biology, chemistry, and physics is necessary for biofluorescence to occur. This characteristic and its widespread nature make it relevant to a large number of researchers and allows for collaboration across scientific fields. Because biofluorescence is often invisible to human eyes without special equipment, many organisms have yet to be tested for fluorescence. Visit the Get Started tab for ways YOU can help scientists make discoveries of biofluorescene and ways to utilize biofluorescence as a tool for teaching science in your classroom.