Sea Spiders: Paddling and Plummeting

Sea Spiders aren't really spiders. They aren't even arachnids. In fact, they're barely more than legs. Not even the daddiest, longleggiest of Daddy Longlegs can out-leg a Sea Spider.

Sea Spiders are marine arthropods found all over the world where they use their toothy snouts to suck out the juices of sea anemones or else tear worms and other slow-moving, soft-bodied prey to bite-sized chunks. Shallow water species can be as small as a single millimetre (0.04 in) long. while those in the peaceful chill of the deep sea and Arctic waters can really stretch their legs and attain legspans of over 70 cm (2.3 ft).

Video: Inner Space Center

Those legs are incredibly important to Sea Spiders, not least because of their relative lack of anything that isn't a leg. The rest of their body is so small that part of their digestive system has to extend into those stilts. Sea Spiders even breathe through their legs, absorbing oxygen through them as if they were gills! Oh, and they use them to walk, too.

And swim! Sea Spiders kind of paddle through the water in just the kind of creepy, crawly way you'd hope or fear a spider would.

Video: PycnoWatchThis

But what goes up must also come down, with the possible exception of plastic bags (when those things get caught on the wind they'll never touch the ground again). Some Sea Spiders refuse to be a plastic bag, they aren't willing to hang around waiting to descend to the seabed. So, they raise their legs up into a comet posture, reducing drag so that they can plummet to the ground that much more quickly.

Once they land, they extend their legs and blossom into the creepiest, crawliest flower you've ever seen. That's why I like Sea Spiders. They're always consistantly creepy no matter what they do. It's oddly comforting.