It’s October, a month dedicated to all things spooky—the cold is creeping in and Halloween is just around the corner. And we’re celebrating all month long by highlighting some of the weird and wonderful creatures you can find right here at the National Aquarium.
Considered a "living fossil," the chambered nautilus has roamed the ocean for more than 400 million years—before the dinosaurs even existed! And little has changed about this creature in its expansive history, except maybe its numbers. Thousands of species of nautilus lived in prehistoric times. Today, only about six living species remain.
A nautilus’ coiled shell is comprised of many gas-filled chambers, which help it swim. The body of the nautilus is contained in just the outermost chamber. When it wants to rise or dive, it pumps fluid into the remaining chambers, modifying its buoyancy. Hatching with just four chambers, the nautilus builds more as it ages, and most have about 30 by the time they are full grown.
More than 90 retractable tentacles allow the nautilus to capture prey, such as shrimp, fish and crabs. Unlike many cephalopods, the nautilus’ tentacles don’t have suckers or hooks. Instead, they are covered in grooves and ridges that stick to prey like glue. The food is then devoured by a crushing, parrot-like beak.
Check back next week for more on the strange side of the animal kingdom!