The Nautilus Is a Living Fossil With an External Shell

Japanese researchers recorded the deep-sea giant squid off the Ogasawara Islands.

With no bones, the only hard part of an octopus is its beak, so it can slip through tiny openings.

The dark cloud confuses the predator's vision and, in some species, dulls its sense of smell.

Their pupils are shaped like the letter W, and they use them to see very well in varied light.