Agriculture
Watching out for vultures
Microbes at the Gas Pump
Protecting Cows—and People—from a Deadly Disease
Amphibians
Bullfrogs
Frogs and Toads
Tree Frogs
Animals
A Fallout Feast for Crabs
Sleepless at Sea
Deep Krill
Behavior
Listen and Learn
Memory by Hypnosis
Training Your Brain to Feel Less Pain
Birds
Kingfishers
Roadrunners
Owls
Chemistry and Materials
Sugary Survival Skill
Scientist Profile: Wally Gilbert
The Incredible Shrunken Kids
Computers
Galaxies on the go
Secrets of an Ancient Computer
The hungry blob at the edge of the universe
Dinosaurs and Fossils
South America's sticky tar pits
Downsized Dinosaurs
A Living Fossil
E Learning Jamaica
2014 GSAT Results for Jamaican Kids
Results of GSAT are in schools this week
E Learning in Jamaica WIN PRIZES and try our Fun Animated Games
Earth
A Volcano's Deadly Ash
Weird, new ant
Arctic Algae Show Climate Change
Environment
Out in the Cold
Shrinking Fish
A Newspaper's Hidden Cost
Finding the Past
Decoding a Beverage Jar
A Human Migration Fueled by Dung?
Words of the Distant Past
Fish
Whale Sharks
Freshwater Fish
Flounder
Food and Nutrition
In Search of the Perfect French Fry
How Super Are Superfruits?
The mercury in that tuna
GSAT English Rules
Order of Adjectives
Capitalization Rules
Finding Subjects and Verbs
GSAT Exam Preparation Jamaica
How are students placed after passing the GSAT exam
GSAT Scholarship
Tarrant High overcoming the odds
GSAT Exams Jamaica Scholarships
Access denied - Disabled boy aces GSAT
2014 GSAT Results for Jamaican Kids
GSAT Exam Preparation
GSAT Mathematics
10 Common Mistakes When Preparing for the GSAT Math Test
Math is a real brain bender
Monkeys Count
Human Body
Gut Germs to the Rescue
From Stem Cell to Any Cell
Sun Screen
Invertebrates
Krill
Arachnids
Roundworms
Mammals
Flying Foxes
Cheetah
African Zebra
Parents
Expert report highlights the importance to parents of reading to children!
How children learn
Choosing a Preschool: What to Consider
Physics
Hold on to your stars, ladies and gentlemen
The Particle Zoo
Dreams of Floating in Space
Plants
Bright Blooms That Glow
Making the most of a meal
Pumping Up Poison Ivy
Reptiles
Sea Turtles
Lizards
Pythons
Space and Astronomy
A Smashing Display
Intruder Alert: Sweeping Space for Dust
Saturn's New Moons
Technology and Engineering
Roll-Up Computer Monitors to Go
Spinach Power for Solar Cells
Algae Motors
The Parts of Speech
Adjectives and Adverbs
Pronouns
Problems with Prepositions
Transportation
Tinkering With the Basic Bike
Revving Up Green Machines
Where rivers run uphill
Weather
Polar Ice Feels the Heat
Either Martians or Mars has gas
Earth's Poles in Peril
Add your Article

Nautiluses

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.

Nautiluses
Nautiluses








Designed and Powered by HBJamaica.com™