Say you're Aquaman back in the early days. You're streaking through the ocean, getting to know your domain, and after a few weeks of dolphins, porpoises, whales, coral reefs and fish, fish, fish, you're growing a little bored with the same old, same old, so you dive down to the lightless depths.
Here's where things start to get really interesting. Phantasmagoric, bioluminescent creatures materialize from the murk. They would eye you with curiosity if they had eyes, but what's the point of vision down here? Luckily your Atlantean heritage grants you not only the ability to see in inky darkness (the darkest dark there is) but also to survive the bone-crushing pressure of all that water above and around you.
Attracted by movement in the distance you zoom down to one of the weirdest places on the planet — a vent in the ocean floor where the Earth's crust is splitting apart and spewing super-heated, toxic seawater from its guts. Surely nothing could live in a hellhole like this. But to your aquatic astonishment, the place is carpeted with huge tubular organisms sprouting out of the ground like gigantic, demented stalks of wheat.
Not only are these things surviving, they're thriving down here. The red plumes that top them off are waving contentedly in the ocean currents as though they couldn't have picked a better spot to settle down. And they're right. These creatures (saddled with the grotesque but evocative label, "tubeworms") are uniquely adapted to flourish in this, the most adverse of growing conditions imaginable.