Edward Weston. Cutaway of a nautilus's home. Roughly 10 inches in diameter, such shells typically have 36 chambers.
depths. To stay above 800-foot depths where it would be crushed, the nautilus pumps water in and out of its shell chambers, like ballast in a submarine, to regulate its buoyancy. Feeding at night, the nautilus relies mainly on smell. Its primitive eyes are lensless, like a pinhole camera. At nine inches it can barely discern what a human can see at 165 yards.
Genetic studies of nautilus...