Mystery of the Floating Octopus Solved

As far back as Aristotle, naturalists have wondered why the females of a strange group of octopuses sport a thin, papery shell when plenty of their tentacled cousins are essentially naked, letting all their slime hang out.

Now, observations indicate the so-called Argonaut octopus uses the outer shell to trap an air bubble, allowing her to control her buoyancy in open water and move along with ease — via Our Amazing Planet