Why do so many deep-sea creatures glow in the dark?
In the pitch-black abyss, up to 90% of creatures make their own light - and they use it for everything from hunting to romance.
The answer
Bioluminescence is the dominant form of communication in the deep ocean, produced through chemical reactions involving luciferin and luciferase enzymes. An estimated 76% of all ocean organisms are bioluminescent, with the percentage rising above 90% in the mesopelagic and bathypelagic zones below 200 meters. Creatures use light for counter-illumination camouflage, attracting prey, startling predators, and finding mates. The dragonfish produces far-red light invisible to most deep-sea species, giving it a private searchlight. Some jellyfish release glowing particles when attacked, essentially calling larger predators to eat their attacker - a brilliant bioluminescent burglar alarm.
Source: National Geographic
- bioluminescence
- deep sea
- marine biology
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