Into the Midnight Zone

Sometime in the nineteen fifties, a sperm whale was killed in Antarctic or sub-Antarctic waters.
Inside its stomach, researchers found the remains of a squid.
The specimen was preserved, identified, placed into a scientific collection...
and then largely forgotten.
Almost seventy years later, scientists looked at it again.
What they found was not simply a misidentified species.
The squid did not belong to any known family.
This is the story of Mobydickia poseidonii, a completely new branch of the oceanic squid family tree that had been sitting inside a museum collection for most of a human lifetime.

Hundreds of meters beneath the Pacific, researchers guided a small remotely operated vehicle toward the entrance of a cave no human had ever entered.

There was no sunlight inside.

Almost nothing was known about the animals living there.

Then the cameras recorded something unexpected.

Green light.

It came from colonies of tiny animals attached to old coral skeletons — a species science had never described before.

This is the story of Corallizoanthus aureus, the first documented bioluminescent animal observed inside a deep-sea cave, and of an unexplored habitat that may have been hiding entire communities from us all along.

Deep beneath the ocean surface, a tiny animal lives inside an enormous structure made almost entirely from mucus.
The animal is a giant larvacean.
Its body may be only a few centimeters long, yet the filtering house surrounding it can grow nearly a meter across. With every beat of its tail, seawater is drawn through an intricate network of biological filters that captures particles too small for most animals to use.
Then, after roughly a day, the larvacean abandons the entire structure.
The house collapses.
And sinks.
This is the story of one of the strangest pieces of biological engineering in the ocean, and how an animal most people have never heard of may help move carbon from the atmosphere toward the deep seafloor.

Its scientific name means vampire squid from hell.
It has enormous eyes, a dark body, webbed arms that can fold over its head, and the ability to release glowing material into the darkness.
For decades, almost everything about the vampire squid seemed to suggest a predator.
But when scientists finally watched it feeding in its natural environment, they discovered something completely different.
The vampire squid survives not by chasing prey, but by collecting the remains of life drifting down from above.
This is the story of an animal that turned one of the most hostile places in the ocean into a refuge.

A whale dies at the surface.
Its body sinks through darkness until it reaches the deep seafloor.
But the story does not end there.
Within hours or days, scavengers arrive. Months later, worms and crustaceans take over. Then, long after the flesh is gone, bacteria begin extracting energy from the bones themselves, creating an ecosystem that may survive for decades.
This is the strange afterlife of a whale, and one of the most extraordinary transformations in the deep ocean.

The goblin shark has been known to science since the nineteenth century. We knew its strange elongated snout. We knew about jaws that can shoot forward farther and faster than those of any other known shark.
But almost everything we knew came from animals pulled out of the deep.
Then two cameras recorded something scientists had been missing for more than a century.
A healthy goblin shark, alive in the darkness where it actually belongs.
This is the story of one of the ocean's most recognizable sharks, and how seeing an animal is not the same thing as knowing how it lives.

In the darkness of the midnight zone lives a deep red fish with tiny useless eyes, an enormous mouth, and a body covered in sensory pores.
For decades, scientists thought its young were a completely different kind of fish. They also believed its males belonged to yet another group.
They were wrong.
This is the extraordinary story of the whalefish family, and of an animal whose transformation is so dramatic that science needed genetics, museum collections, and more than a century of investigation to understand what it was actually looking at.

More than two kilometers beneath the Pacific, researchers encountered an animal that seemed to be assembled from the wrong pieces. It had the foot of a snail, the transparent body of a jelly, a cavernous hood for catching prey, and a tail capable of producing living light.
For more than two decades, scientists followed this strange animal through the midnight zone before finally giving it a name: Bathydevius caudactylus.
This is the story of the mystery mollusc, and of what happens when life evolves in a world where sunlight never arrives.