Fast Facts: Nautilus

by AMNH on

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Chambered Nautilus
Chambered nautiluses are sometimes called living fossils because they so closely resemble ancient cephalopods like ammonites. 
Image courtesy of T.B. Smith 

The family of nautiloids has been around, and mostly unchanged, for hundreds of millions of years, but researchers still have a lot to learn about them. Here are a few facts we do know about these mysterious mollusks.

1. The nautilus moves by forcing powerful jets of water out through an organ called the siphon, propelling itself in the opposite direction of the jet flow.

2. Modern nautiluses are sometimes called living fossils, due to their close resemblance to ancient ancestors like the ammonite.

3. Some species of nautilus migrate vertically, rising to shallow water to feed at dusk and moving back to the depths they call home near dawn.

4. Nautilus vision is very poor, as their eyes have no lens. When searching for food, they rely mostly on their sense of smell.

5. When threatened, a nautilus will retreat into its shell, covering the opening with a thick, leathery hood. 

You can learn more and see a live nautilus up close at Life at the Limits, opening April 4, which is free for Members.