Article Summary #1
Over the past 500 million years, the nautilus has remained a lesser-studies
creature that is interesting scientists around the world. This sometimes-labeled
"living fossil" lurks in the muddy ocean floor more than one thousand feet
under he tropical western Pacific Ocean. It later emerges at night
to feed on the coral reefs. These peculiar animals look like large
snails with several tentacles. Their closest living relatives are the squid
and octopus. Only very few species remain, but more is becoming known
about their strange lifestyle.
Paleontologists have linked this animal to the dinosaurs with the comparison of great scaly lizards coming out at night to prey. It intrigued those as early as the Greeks. Its beautiful shell often fascinated them. When split apart, the nautilus shell shows a winding, chambered spiral that has a pearl-like appearance. Centuries passes before other scientists could begin to unmask the characteristics of this animal.
The nautilus combines its features from other sea life. It swims above the sea floor like a fish. It has tentacles and a jet propulsion system like other cephalopods; however, instead of the 8 or 10 tentacles of the mollusks, it has about 90. No other known cephalopod has a shell quite like it. This animal actually only lives in the last chamber of its shell. As it grows, it adds a new chamber and moves into it. As the nautilus moves up the reef walls, one can see that the lack of a true lens inhibits it from being deterred from light. They make enormous water-jet-powered migrations in an upward manner. It has nothing to do with their buoyancy; rather the water is pushed into its gills while extracting oxygen creating jet forwardness.
The nautilus is being studied at greater lengths to uncover its characteristics. Its uniqueness has made it difficult to categorize it into a specific quality. Its durability has allowed it to survive in the deep waters of the sea. Hopefully, it will become more known so we can continue to learn about this wonderful creature.
From Discover, Coils of Time by Peter D. Ward, March 1998, p. 100-106.