Like many other deep-sea jellies, some species of Atolla have a deep red hue and a set of flashing bioluminescent organs.

If you’re being hunted by the female anglerfish, the last thing you’ll ever see is a flashing blue-green light dangling from its forehead.

The phromina, a small, translucent crustacean, makes its home inside its victims’ hollowed-out bodies.

A salp is a gelatinous zooplankton that, unlike jellyfish, has complex nervous, circulatory and digestive systems, complete with a brain, heart, and intestines.

Part creature, part colony, the siphonophore is a chain of specialized body parts that work together—glowing, stinging, and surviving as one.

With built-in heaters for its eyes and brain, the swordfish hunts swiftly in the cold, dark twilight zone—slashing prey with its sword-like bill in deep-sea ambushes.

Krill may be tiny, but their presence in the ocean is mighty. They exist in huge numbers worldwide, provide an essential link in the marine food chain, and even help regulate global climate.