Okay, I'll admit it: I'm terrified of fish. Horrified, mortified, petrified—the works. If it came down to a choice between lying in a coffin crawling with spiders or sitting in a bathtub with one little goldfish paddling about—I'd take the spiders. So there's precisely zero chance I'll ever find myself in a bathysphere 2,000 feet underwater, which means I'll just have to read about what goes on down there:

To understand the full extent of the constraints that the abyss places on life, consider the black seadevil [right]. It's a somber, grapefruit-sized globe of a fish—seemingly all fangs and gape—with a "fishing rod" affixed between its eyes whose luminescent bait jerks above the trap-like mouth. Clearly, food is a priority for this creature, for it can swallow a victim nearly as large as itself. But that is only half the story, for this description pertains solely to the female: the male is a minnow-like being content to feed on specks in the sea—until, that is, he encounters his sexual partner.

The first time that a male black seadevil meets his much larger mate, he bites her and never lets go. Over time, his veins and arteries grow together with hers, until he becomes a fetus-like dependent who receives from his mate's blood all the food, oxygen, and hormones he requires to exist. The cost of this utter dependence is a loss of function in all of his organs except his testicles, but even these, it seems, are stimulated to action solely at the pleasure of the engulfing female. When she has had her way with him, the male seadevil simply vanishes, having been completely absorbed and dissipated into the flesh of his paramour, leaving her free to seek another mate. Not even Dante imagined such a fate.

That's from Tim Flannery's great review of two new books about deep-sea creatures. He also hazards a guess as to why most folks are more intrigued by the thought of going to Mars than exploring the depths of the ocean floor:

Is it the geography of Christian belief that has made us upright apes so dread the ocean deep, yet strive so mightily to explore the cold and (so far as we know) lifeless heavens? Not all human beings think as Beebe did. The Greenland Inuit, for example, believe that paradise lies at the bottom of the sea, for that is where their food comes from. It is the cloudy, frozen mountains and sky that they fear and shun. Whatever the cause, human beings know more about the surface of that dead rock we call the moon than the living depths of our own planet's seas.

Got a better theory? The last section of the essay is more depressing, about how all of the industrial waste and sewage humans have dumped into the ocean—scuttled ships, thousands of tons of chemical weapons, obsolete nuclear reactors—have wreaked no small amount of havoc on the sea floor. It's hard to care, until that gunk comes traveling back up the food chain. ("The liver-like glands of one species of shrimp... have levels of polonium-210 a million times that of seawater.") So there's reason to care beyond the (undeniable) fact that there's lots of awesomely wacky stuff down there...

P.S. This was traumatizing but cool.