Cool Sea Creatures: Chambered Nautilus

Chambered nautilus also know as the Nautilus and scientifically known as Nautilus pompilius. Considered by most people to be a living fossil. Being one of the largest and most common out of about six species that are still around today. As an adult it can grow up to about 8 inches. And like the coelacanth over 400 million years still remains the same. In the days of the dinosaurs there were up to 10,000 different species of nautilus through out the ocean. But today only a handful still exist.

Found throughout the Pacific and Indian oceans. During the day they are at the depths of about 1,800 feet. At night they will migrate to shallower waters where they will feed among the coral reefs. The shell cannot withstand intense pressures. So you won't find them any deeper than 2,600 feet.

It is a mollusk for is does have a shell, but is a member of the cephalopod family. In case you don't know what cephalopod is, its creatures like octopus, squid, and cuddle fish. Which are closely related. Like most cephalopods, it uses jet propulsion to reach speeds up to over two knots. Jet propulsion is done with these two small tubes near the tentacles. It siphons up water and expels it under pressure. Which propels the nautilus in the opposite direction at high speeds.

The shell is made up of many individual chambers. Each chamber is individually sealed and contains an amount of gas. Which provides the nautiulus with buoyancy. It can regulate it density by injecting or removing flud into each chamber through a system of tubes. This strong shell provides protection for its soft body, king of like a hermet crab.

Depending on particular species there can as much as 90 separate tentacles on a nautilus. But unlike other cephalopod they don't have any suction cups. Yet they still use their tentacles to catch shrimp, fish, and small crustaceans. And like most cephalopods crushes it with its powerful beak. They are acitive preadators but with the little energy that its siphon system uses. They only need to eat about once a month. They have very poor eyesight for their eyes have no lenses. Instead, there's a tiny hole to allow light into the eye. This system operates like a pinhole camera. Having such poor eyesight it relies mainly on its sense of smell when searching for food or possibly looking for a mate.

The nautilus reproduces by laying eggs. These eggs are usually attached to rocks in shallower water, hidden away from curious predators. They take anywhere between eight to twelve months to fully develop. When they hatch they are about one inch in diameter and they shell only has seven chambers. They will drift and feed on plankton and other small prey as it grows. As they get larger it will add new chambers to its shell. Each new chamber will be a little larger than the last allowing the opening of the shell to continously grow larger. The average life span is believed to be about twenty years. Which is unusually long for a member in the cephalopd family. Their life and habitat are mostly a mystery since they spend most of their time in the deep. But it is known that thier population is on a decline because of the harvesting of their beautiful shells.