What is biofluorescence?
Biofluorescence is the illumination produced by some organisms, when they absorb light, temporarily store its energy and then re-emit it as light of a different color.
biofluorescence in action
By Parent Géry [Public domain], from Wikimedia Commons
By Konstantin Geis
biofluorescence is different than bioluminescence
Biofluorescence is often confused with bioluminescence, which is also an illuminating effect but has different chemistry, biology and physics as well as a significantly different appearance.
You can observe bioluminescence by turning your torch off and creating a current of water. Luminescent organisms create light voluntarily, just like the fireflies do.