What is bioluminescence?

Bioluminescence occurs when a molecule called luciferin reacts with oxygen, catalysed by the enzyme luciferase, releasing energy as light with very little heat. Different organisms have evolved bioluminescence independently at least 40 to 50 times. In the deep ocean, where no sunlight reaches, roughly 75 percent of species glow. They use light to attract mates, lure prey, confuse predators or communicate. Fireflies flash to find partners, anglerfish dangle a glowing lure and some squid use it for counter-illumination camouflage. The jellyfish Aequorea victoria produces green fluorescent protein (GFP), a tool that has revolutionised cell biology.