Living Flashlights in the Dark
In the deep sea, light is a luxury. Because no sunlight penetrates past 1,000 meters (3,300 feet), over 75% of deep-sea creatures create their own light through a chemical process called bioluminescence.
The most famous example is the Anglerfish. Females sport a glowing, fleshy lure that dangles from their heads. Unsuspecting prey swim toward the light, only to be snapped up by a mouth full of translucent, needle-like teeth. Other creatures, like the Hatchetfish, use bioluminescence for camouflage. They light up their bellies to match the faint light filtering from above, making themselves completely invisible to predators swimming below them.
Defying Extreme Pressure
At the bottom of the ocean, the weight of the water creates a crushing environment. To survive, deep-sea animals have abandoned the structure of typical land and shallow-water creatures.
Take the Blobfish, once voted the world’s ugliest animal. In its natural habitat thousands of feet down, it looks like a normal, functional fish. Because it has no bones and gelatinous flesh, the intense water pressure naturally holds its body together. It only turns into a sad, melting puddle of goo when it is dragged to the surface where the air pressure is too low.
The Immortals and the Giants
The deep sea is also home to a phenomenon known as abyssal gigantism. For reasons scientists still don’t fully understand, invertebrates grow to massive sizes in the deep. The Giant Squid can reach lengths of up to 13 meters (43 feet), featuring eyes the size of dinner plates to capture the faintest traces of light.
Furthermore, the freezing temperatures and scarce food supplies slow down metabolism to a crawl. This allows deep-sea creatures to live for centuries. Scientists recently discovered deep-sea black corals that have been alive for over 4,000 years, making them some of the oldest living organisms on our planet.
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