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.