Nautilida

Common Names

Nautilida is commonly known as nautilus or chambered nautilus. The term "nautilus" can also refer to the entire order, but it is more commonly used to refer to the living species, Nautilus pompilius.

Characteristics

Members of the order Nautilida share several key characteristics:

• Coiled shell: The most distinctive feature of nautilids is their coiled, external shell, which is divided into chambers. The animal lives in the outermost chamber, while the other chambers are filled with gas to regulate buoyancy.
• Siphuncle: A tube called the siphuncle runs through the center of the shell, connecting all the chambers. This tube allows the nautilus to regulate the gas content of the chambers, enabling it to adjust its buoyancy.
• Simple eyes: Unlike many other cephalopods, nautilids have simple, pinhole eyes that lack lenses. These eyes are capable of detecting light and movement but do not form sharp images.
• Numerous tentacles: Nautilids have numerous tentacles, which they use for locomotion and capturing prey. They lack the specialized suckers that are present in other cephalopods.

Environment

Nautilids are primarily found in the Indo-Pacific region, where they live in deep waters, often in the vicinity of coral reefs. They are nocturnal predators, feeding on crustaceans and other small marine animals. Their coiled shells provide protection from predators and allow them to adjust their buoyancy to maneuver through the water column.

References

For more information on Nautilida, you can visit these websites:

• Wikipedia: Nautilida
• Natural History Museum: Nautilus
• Smithsonian Ocean Portal: Nautilus