Nautilus pompilius (chambered nautilus, pearly nautilus), a species of cephalopod in the family Nautilidae: longitudinal section of shell showing chambers.
A longitudinal section of a nautilus shell, showing chambers.
Nautilus in Berlin Zoo Aquarium J. Baecker / public domain
Today, nautiluses are confined to the Indo-Pacific, with most located near coastal areas of the Indian Ocean or the western Pacific Ocean.
While the shell of a chambered nautilus is there to protect it from predators, it doesn't help protect it from humans who want to sell its shell.