What lives a mile under the sea, has tentacles and fins and looks like a decapitated chicken? The headless chicken monster, of course. Yes, that is actually the name of a rare creature caught on film by researchers in the Southern Ocean. The “monster” — a sea cucumber that helps to filter organic matter on the ocean floor — has been caught on film only once before, last year in the Gulf of Mexico.
Unlike most sea cucumbers, the headless chicken monster has fins, which allow it to swim upward to escape predators. Discovering the animal near Antarctica could help scientists understand the species’ distribution, and how it might be affected by climate change. Scientists have “absolutely no idea” how many there are in the world’s oceans, said researcher Dirk Welsford. It’s “an amazing reflection of how little we know about the deep ocean.”
Surprising vortex keeps dandelions afloat
Come seed time, children can’t resist blowing on dandelions’ silvery tufted heads, sending the seeds 60 miles or more. But no one had figured out the details of that flight.
The scientists knew that the key was the tuft atop the stem called a pappus. It is made up of a sparse thicket of filaments that seemed to act like a balloon or a parachute. But researchers at the University of Edinburgh in Scotland discovered that above the pappus, the air flow took the form of a separated vortex ring, a kind of swirling eddy that had been considered a theoretical possibility, but was thought to be too unstable to exist in reality. It was, they wrote, “a new class of fluid behavior” — air being the fluid in this case. “The dandelion flies in such a way that it forms a vortex that contributes to keeping the dandelion afloat as long as possible,” Ignazio Maria Viola said. The filaments make the pappus four times as efficient at staying afloat as a simple flat disc.