Right. So. The show I just watched, on my delightful Discovery HD, was focusing on a deep sea sub exploring active (and, more interesting) defunct volcanic fissures along the bottom of the Atlantic and Pacific, near the crevices of the tectonic plates.
What was fascinating were the HUGE swarms of creatures living on active volcanic fissures, which themselves are tall pillars that build and build themselves hundreds of feet tall as they boil away water, cool, leave deposits, and continue to spew.
All manner of creatures, in water that's 650 degrees, with almost four hundred PSI. There were delicate shrimp that lived to eat bacteria out of things which formed to look like bowls. The shrimp, who are not perhaps the brightest creatures, would dip in and out of the searing water, usually burning off their own exoskeletons and outer limbers.
...
What really fascinated me, though, were what happend when the volcanic fissures stopped spewing and went dead.
Of couse, all the millions of creatures who exist (impossibly) all died out. They couldn't move, they weree entirely dependent on this specialized enviroment, so they died out.
But when they showed footage of these defunct towers of sediment and volcanic ash....there are thin and glowing strands, like thick spiderwebs, stretched and draped across all of the sharp crags. And these creatures, huge and multi-legged and glowing pure white, who dispensed them.
Carrion eaters, of a sort. And so beautiful. I wish I knew what they were called, I'd find a picture of them to post.