Nautilidae is a large family of cephalopods that the Nautilus is a part of. It encompasses six species in 2 different genotypes, with the genus Nautilus as the archetype. Although it more particularly refers to the species Nautilus pompilius, any Nautilidae member can also go by the label of chambered  Nautilus.

The name Nautilus comes from the Greek word “Nautilos,” which means “seaman.” Species like the chambered Nautilus have been around for nearly 500 million years, according to fossil records.


Typically, Nautiluses have a similar appearance to other Nautiluses. Nautilus has smooth, rolled shells across the board. Although the shell’s form is sometimes cited as an illustration of a golden spiral, the ratio really only represents a virtually perfect exponential virtuous cycle. With the help of specially folded tentacles, Nautiluses may entirely draw themselves within their shell and seal the aperture, providing them with safety. 

Nautilus at depths where light is not visible.
Nautilus at depths where light is not visible

The casing is matte white on the exterior and shimmering white or turquoise on the interior. Additionally, the shell frequently displays countershading. Countershading on the  Nautilus is in the form of a dark top and a bright bottom. There are multiple chambers inside the shell that are all joined in the center by a duct called the siphuncle.


Nautiluses are carnivorous creatures. Depending on the species, a  Nautilus has 60 to 90 limbs that are all different lengths. These delicate tentacles, or cirri, are entirely retractable and are formed of soft, flexible material. 

In addition to having microscopic hairs called cilia near the tips of each appendage that they use to sniff for food, each arm is covered in an adhesive substance that sticks to things. It has been established that  Nautilus has poor eyesight, so they heavily rely on smell detection. In addition to being predators,  Nautiluses are scavengers. They consume all types of carrion, including the molts of lobsters and hermit crabs.


 Nautiluses are mostly located in the western Pacific Ocean and Indian Ocean’s coastlines. Most widely found in Southeast Asia and Australia, they favor warm, temperate waters. The seas along the Great Barrier Reef, the Philippines, southern Japan, and Indonesia are home to a very high concentration of  Nautiluses. They spend most of their time at depths between 300 and 2,300 ft and frequently gather along coral reef edges. 

Nautilus with slightly closed aperture.
Nautilus with slightly closed aperture

Nevertheless, one may occasionally discover them in quite shallow water. In order to sustain, breed, and lay eggs, they are predominantly active during nighttime, being nocturnal creatures. Throughout the day, they wind down and descend into depths.  Nautiluses like water that is cooler than 75 °F and stay away from sea temperatures.


Nautiluses have a far longer lifespan in the wild, reaching up to 20 years.  Nautiluses mature sexually, on average, between the ages of 10-15. There is no set time of year when  Nautiluses mate. They may reproduce at any time of year and prefer to do it near the surface. 

Nautiluses mate face-to-face, and at this time, the male will utilize four specialized appendages that form an organ called a spadix to deliver his sperm to the female’s mantle. Hour-long mating bouts are not uncommon, and males occasionally bite the females where they latched in during the mating, leaving puncture marks. Females produce relatively few eggs, with the majority producing 10-18 eggs annually.


The primary danger to  Nautiluses, outside their natural predators, is human activities. In addition to being used as food,  Nautiluses are also harvested for relics and memorabilia. People cherish their shells for their shape and color since the interior doubles as a good alternative for jewels.

Nautilus enclosed in its shell since diver is close.
Nautilus is enclosed in its shell since the diver is close

The octopus, in addition to sharks, groupers, sea turtles, and triggerfish, is among the primary predators of the  Nautilus. To evade predators,  Nautiluses descend well below the sea during the day. Their shells’ countershading helps them evade being discovered.  Nautiluses will retreat within their shells and seal the aperture with a leathery hood made of a specific pair of folded arms when they perceive a threat.

Facts about the Nautilus

  1. Nautilus uses water jet propulsion to get around.
  2. Nautilus has tremendous buoyancy control mechanisms inside the shell.
  3. The confirmed maximum depth for  Nautiluses is 2,575 ft, where the shell implodes from the pressure.
  4. The largest known cephalopod eggs are from Nautilus.
  5. Nautilus shells are the best natural example of a logarithmic spiral.


Is a Nautilus a dinosaur?

A cephalopod is a creature like the Nautilus that also includes octopi, squid, and cuttlefish. It has been around for 500 million years; its predecessors predate fish and even dinosaurs.

Are Nautilus intelligent?

The intellect of the Nautilus is quite modest compared to that of other cephalopods. It’s smart. However, its memory capacity is rather poor. The nautilus has some degree of memory, but it forgets knowledge that more developed cephalopods may retain for several weeks after only a few hours.

Is a Nautilus venomous?

All cephalopods, with the exception of a few remaining Nautilus species, are regarded to be poisonous. The other octopuses also utilize venom to capture prey, but only the little blue-ringed octopus is harmful to humans.

Do Nautilus leave their shell?

The only cephalopod with a shell that can be examined is a nautilus. The shell offers security in addition to being attractive. The nautilus has a fleshy aperture called a hood that it may use to lock the shell shut when it wants to retreat within. The diameter of a nautilus shell may be between 8 and 10 inches.

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