The Chambered Nautilus is a living species of the Nautilus Cephalopods. The shell of the Nautilus is subdivided into various rooms which are connected by a tube called the siphuncle. They are able to use the shell as a buoyancy compensation device. They can fill the rooms (camera) with water, air, or possibly sediment to balance their body in the water. This makes the Cephalopod an excellent predator.