Lights in the Deep: The Mystery of Bioluminescence

Beyond the reach of sunlight, in the deep ocean, an extraordinary kind of light show takes place. Around ninety per cent the creatures living in this dark realm can produce their own light, a phenomenon known as bioluminescence. It evolved independently many times, strongly suggests that the ability offers real survival advantages. Some fish use flashing lights to lure prey close enough catch, while others communicate means of light signals that only members of the same species can recognise. Despite the technical challenges, researchers remain deeply interested studying these glowing species, including fish tiny light organs cover almost their entire body. This cold light, created by a chemical reaction rather than by heating a filament, contrasts sharply with an ordinary light bulb, in which as much ninety per cent of the energy turns into heat rather than light. In some species, the light produced is so intense it can temporarily blind potential predators, giving the prey precious seconds to escape.