Nautilus pompilius pompilius, Emperor Nautilus [+]

Kingdom Animalia Phylum Mollusca Class Cephalopoda Order Nautilida Family Nautilidae Genus Nautilus species: Nautilus pompilius pompilius [+ITIS +WoRMS]

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Description & Behavior

The emperor nautilus, Nautilus pompilius pompilius (Linnaeus, 1758), reaches about 20 cm in length. The spiral shell of this chambered nautilus is thin and smooth with a brown and white pattern. Up to 30 chambers are created in the shell as the animal increases in size and moves to occupy the outermost chamber. The chambered nautilus maintains buoyancy through a gas passed through a tube in the shell tube called a siphuncle. This also helps the animal stay upright in the water. The chambered nautilus has about 90 small suckerless tentacles found on the body close to where it is attached to the shell. This mollusk has eyes but they do not have a cornea or lens. Nautilus and Allonautilus are the last living genera of externally shelled cephalopods.

World Range & Habitat

The emperor nautilus, Nautilus pompilius pompilius, is found in the western Pacific Ocean. They are often found near the ocean bottom or near coral reefs in waters up to 500 m deep, but they travel to shallower waters at night.

» GBIF occurrence data in Google Earth [Tips] | Ocean Biogeographic Information System (OBIS) (World Distribution) [about]

Feeding Behavior (Ecology)

The primitive eyes of the the emperor nautilus, Nautilus pompilius pompilius, are not effective for finding prey, therefore the animals uses its acute sense of smell to find small fishes and crabs. They are also known to feed on carrion.

Life History

The emperor nautilus, Nautilus pompilius pompilius, reaches sexual maturity at between 15-20 years of age and reproduces through internal fertilization. The male transfers sperm to the female using 4 of its tentacles through a spermatophore with a protective coating that contains a mass of sperm, which adheres to the female's mantle wall. After the spermatophore is transferred to the female, the coating dissolves and the sperm is released. Females then lay fertilized eggs, each about 3.8 cm in length. The shell of the newly hatched chambered nautilus is about 2.5 cm in diameter.

Conservation Status/Additional Comments

What we don't know about nautilus - by Dr. James B. Wood, The Cephalopod Page

The emperor nautilus, Nautilus pompilius pompilius, first appeared around 550 million years ago during the early Paleozoic era. According to fossil records, some had shells between 6-9 m long when uncoiled.

Unfortunately the nautilus shell is widely collected by humans and therefore commercial fishing for this animal is common. Since 1987, export of chambered nautilus shells has been banned, but many countries continue to sell them. A small percentage are also taken for the aquarium trade. Over the course of 2 years, as many as 10,000 live animals have been caught and killed for their shells.