Friday, January 21, 2011

Ancient Animals

What do you see in this picture?

Photo by Hans Hillewaert  Source:  Wikipedia

At first glance did you see the head of a dragon?  I did (Yeah, I know - I'm a little out there.)  But then I thought 'Ewww, what a weird dragon.'  You're looking at the eye of a nautilus - a creature that has been around for and changed little in 500 million years.  If you're thinking it has a strange-looking eye, you're right.  Its eye has no lens - what is known as a 'pinhole' eye.  It can see, but not very well, so relies more on its sense of smell than on vision to navigate and hunt.

The nautilus is a cephalopod and belongs to the same family as cuttlefish and squid, but the nautilus has retained its shell.  A very remarkable shell.  There is a reason it's also known as the chambered nautilus.

Photo by Chris 73  Source:  Wikipedia

Why the chambers?  As the animal grows it moves into an increasingly larger space, closing off the old space as it goes except for a small duct it uses for filling the unused chambers with air to aid in flotation.  Unfortunately, lots of people are enamored by its shell and the nautilus is hunted for it.

In the first picture the funny things sticking out of the shell are its tentacles.  It has up to 90 of them, but they don't have suckers like an octopus; they do have ridges though that allow a firm grip on its prey which includes shrimp, small crustaceans and fish.

Photo by Lee Berger   Source:  Wikipedia

Compared to its cousins the squid and octopus, the nautilus is a rather slow and lumbering member of the family.  It is not thought of as intelligent as its octopus relatives (more on that in an upcoming post), but perhaps the nautilus doesn't care as it has a beautiful house in which to live.  For a video and more information on the nautilus, click here.

1 comment:

  1. My first thought was SQUID.
    I was close ...
    I have a photos somewhere of a Nautilus shell washed up on a beach in the Seychelles.

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