Protecting Cows—and People—from a Deadly Disease
Where Have All the Bees Gone?
Silk’s superpowers
Frogs and Toads
Salamanders and Newts
Mouse Songs
Dolphin Sponge Moms
Polar Bears in Trouble
Training Your Brain to Feel Less Pain
The Electric Brain
Lost Sight, Found Sound
Chemistry and Materials
Makeup Science
Fog Buster
A Framework for Growing Bone
A New Look at Saturn's rings
Two monkeys see a more colorful world
Troubles with Hubble
Dinosaurs and Fossils
Watery Fate for Nature's Gliders
Digging Dinos
Dinosaurs Grow Up
E Learning Jamaica
Results of GSAT are in schools this week
E Learning in Jamaica WIN PRIZES and try our Fun Animated Games
2014 GSAT Results for Jamaican Kids
Quick Quake Alerts
On the Trail of America's Next Top Scientists
Drilling Deep for Fuel
Little Bits of Trouble
Food Web Woes
Antarctica warms, which threatens penguins
Finding the Past
The Puzzle of Ancient Mariners
Fakes in the museum
Stone Age Sole Survivors
Electric Catfish
Whale Sharks
Food and Nutrition
The Color of Health
How Super Are Superfruits?
Packing Fat
GSAT English Rules
Problems with Prepositions
Who vs. That vs. Which
Order of Adjectives
GSAT Exam Preparation Jamaica
Results of GSAT are in schools this week
Ministry of Education Announces 82 GSAT Scholarships for 2010
42,000 students will sit for the GSAT Exam in two weeks
GSAT Exams Jamaica Scholarships
GSAT Scholarship
GSAT Exam Preparation
42,000 students will sit for the GSAT Exam in two weeks
GSAT Mathematics
Math and our number sense:
Prime Time for Cicadas
Deep-space dancers
Human Body
Sea Kids See Clearly Underwater
Smiles Turn Away Colds
Workouts: Does Stretching Help?
Camel Spiders
Miniature Schnauzers
Expert report highlights the importance to parents of reading to children!
What Not to Say to Emerging Readers
Raise a Lifelong Reader by Reading Aloud
Road Bumps
Echoes of a Stretched Egg
Powering Ball Lightning
Nature's Alphabet
The algae invasion
Tracking the Sun Improves Plant Pollen
Sea Turtles
Gila Monsters
Space and Astronomy
World of Three Suns
Melting Snow on Mars
Catching a Comet's Tail
Technology and Engineering
Algae Motors
Squeezing Oil from Old Wells
Dancing with Robots
The Parts of Speech
What is a Noun
Adjectives and Adverbs
Countable and Uncountable Nouns
Seen on the Science Fair Scene
Revving Up Green Machines
Flying the Hyper Skies
Either Martians or Mars has gas
Arctic Melt
Weekend Weather Really Is Different
Add your Article


Nautilus (from Greek nautilos, 'sailor') is the common name of any marine creatures of the cephalopod family Nautilidae, the sole family of the suborder Nautilina. It comprises 6 very similar species in 2 genera, the type of which is the genus Nautilus. The name chambered nautilus is also used for any species of the Nautilidae, though it more specifically refers to the species Nautilus pompilius suluensis. Living fossils: Having survived relatively unchanged during millions of years, nautiluses represent the only living members of the subclass Nautiloidea, and are often considered to be "living fossils". No suckers, many tentactles, nine teeth: The nautilus is similar in general form to other cephalopods, with a prominent head and tentacles. Nautiluses typically have more tentacles than other cephalpods, up to ninety. These tentacles are arranged into two circles and, unlike the tentacles of other cephalopods, they have no suckers, are undifferentiated and retractable. The radula is wide and distinctively has nine teeth. There are two pairs of gills. The largest adults can reach 220 mm in diameter. Pearly insides: Nautiluses are the sole cephalopods whose bony structure of the body is externalized as a shell. The animal can withdraw completely into its shell, closing the opening with a leathery hood formed from two specially folded tentacles. The shell is coiled, calcareous, mother-of-pearl-lined and pressure resistant (imploding at a depth of about 800 m). The nautilus shell is composed of 2 layers: the outer layer is a matte white, while the inner layer is a striking white with iridescence. The innermost portion of the shell is pearlescent, blue-gray. The osmena pearl, contrarily to its name, is not a pearl, but a jewelry product derived from this part of the shell. Chambers in the shell: The shell is internally divided into chambers, the chambered section being called the phragmocone. The phragmocone is divided into camerae by septa, all of which are pierced in the middle by a duct, the siphuncle. As the nautilus matures its body moves forward, sealing the camerae behind it with a new septum. The last fully open chamber, also the largest one, is used as the living chamber. The number of camerae increases from around four at the moment of hatching to thirty or more in adults. Cryptic coloring: The shell coloration also keeps the animal cryptic in the water. When seen from the top, the shell is darker in color and marked with irregular stripes, which makes it blend into the darkness of the water below. On the contrary, the underside is almost completely white, making the animal indistinguishable from brighter waters near the ocean surface. This mode of camouflage is named countershading. One of the finest natural logarithmic spiral: The nautilus shell presents one of the finest natural examples of a logarithmic spiral. (It is sometimes incorrectly claimed to be a golden spiral as well.) Jet propulsion: In order to swim, the nautilus draws water into and out of the living chamber with the hyponome, which makes use of jet propulsion. When water is inside the chamber, the siphuncle extracts salt from it and diffuses it into the blood. When water is pumped out, the animal adjusts it buoyancy with the gas contained in the chamber. Buoyancy can be controlled by the osmotical pumping of gas and fluid into or from the camerae along the siphuncles. The control of buoyancy in this manner limits the nautilus; they cannot operate under extreme hydrostatic pressures. The animal can also crawl on land or on the seabed. In the wild nautiluses usually inhabit depths of about 600-800 m, rising to around 200 m at night for feeding, mating and egg laying. Tentacle capture: Nautiluses are predators and feed mainly on shrimps, small fish and crustaceans, which are captured by the tentacles. Unlike other cephalopods, they do not have good vision; their eye structure is highly developed but lacks a solid lens. They have a simple "pinhole" lens through which water can pass. Instead of vision, the animal is thought to use olfaction as the primary sensory means during foraging, locating or identifying sexual partner. 12 month development: Nautiluses are sexually dimorphic and reproduce by laying eggs. Attached to rocks in shallow waters, the eggs take twelve months to develop before hatching out at around 30 mm long. The lifespan of nautiluses is about 20 years, which is exceptionally long for a cephalopod.


Designed and Powered by™