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A Blind Swimming Wonder: The Electric Elephant-Nose Fish
If you've seen my picture, I can guess what you're thinking.
But when I tell you about myself, I think you'll forgive my ugly appearance. Above
all, I hope you'll say about my wonderful Designer, “He's Marvelous!”
First let me ask you a question: What would you do if you had to
live all the time in a fog so dense that you could not see anything around you, so
dense that you could not see enough even to locate any food to eat; or find a friend
to talk to? What would you do?
That is the problem some of us tropical fresh water fish have.
But our vision is not hindered by fog but by mud. We live in such murky water that eyes
such as most fish have are useless.
A problem? Not for my masterful Designer! He has actually worked
out a way for me to “see” through the mud using my own home-made electricity
Scientists have called me a “weak electric fish” because
I make only a very small amount of electricity (about one volt), but that doesn't
mean the process is simple. In fact, my Designer thought up a plan so complicated
that He had to give me a super-size brain to be able to do all the calculating
required. It's said that in relation to the size of my body, my brain is bigger
than yours! And it is ten times bigger than that of most fish!
So I must have a super-size head? No, my Creator actually
made my brain in a very special way so that I can have a lot of brain in a very
small head. He designed my brain with folds in it, much as you would put folds
in a blanket or a piece of cloth. If that isn't design! You see, He knew
I would need the extra brain capacity for my highly specialized electric “eyes.”
Part of the process of "seeing" for me is performing a huge amount of mathematical
calculations very quickly-before my dinner swims away (if it is good to eat!), or
before it attacks me (if it is something dangerous).
Now there is another side to this extra amount of brain:
Brain tissue consumes energy at a rate ten times faster than average body tissue.
You might think of me as you would think of a special kind of automobile that
requires between 20 and 30 times as much gasoline as the average car! Most animals
use between two and eight percent of their energy to power their brains. Humans use
about 20%. My brain gets about 60% of the energy generated from the food I eat.
So what is my biggest problem? You guessed it—I'm always hungry!
One thing I can tell you for sure, my kind didn't just happen.
In fact, I've heard that some scientists have spent years studying us in the laboratories,
trying to understand just how we make and use electricity to identify what is in our
environment.
How does it work? First of all, my Creator has equipped me with
some very special hardware. I have cells in my tail that act like tiny batteries connected
in series. When my brain sends a message to these cells in my tail, telling them to
“Fire!” they fire. This creates an electrical field in the area
around my body.
But that is only half of it. My Creator has also equipped me with
electro-receptors. These devices, imbedded just under the surface of my skin, are so
sensitive that they can detect the slightest change in that electrical field around my
body. When a moving object enters the electric field, these electro-receptors pick up
the information (its location, size, color, thickness, even its consistency) and send
all this information to my brain. In just a fraction of a second, my brain has analyzed
the information and I know exactly what the object is—whether it is something good for
dinner, or just a piece of shell or stone. Or an enemy.
When a delectable animal swims into my electric field, do you
know what I do? I swim backwards to grab it. Why? If I were to continue in forward
motion, I'd likely miss it, because by the time I detected the prey with the current
from my tail and turned around, the prey would be safely out of range! By quickly
shifting into my “reverse” gear, it's an easy catch! Then I use those funny trunk-like
projections on my nose to suck it in (they are just right for worms, bugs and zooplankton.
Uummm!).
Using this same electric field my Designer has made me able to
“talk” to other electric fish. I can't tell you much about the language we use, but we
have no difficulty understanding each other.
Now I have a question for you. When I go traveling I often
encounter other electric fish just like myself, who also surround themselves with an
electric field to be able to “see” and “talk.” Now just picture five of us, each with
our own electric field, each sensing the others' fields. Can you imagine the confusion
when we try to “talk” among ourselves?
Wouldn't you think we would “jam” each other's receptors,
so that none of us would know anything, because each of us reads information at
the same fixed frequency?
Well, my Creator thought of this problem before I came along,
and prepared an easy, effective solution. When I meet another electric elephant-nose fish,
my frequency automatically changes just slightly, so that it is different from that of the
others. In fact, all of us in a group will change to different frequencies! Say I'm
broadcasting at 400 Hertz, I may go up suddenly to 405 Hertz. Maybe my neighbor will
drop to 399 Hertz, another may go up to 402, and so on, so that each of us can do our
own “broadcasting” without interfering with the other. The result: Total order, and
total jamming avoidance. We can have a clear, friendly conversation. And when we swim
away from each other, each of us returns to our own normal frequency.
I've heard that our technique of jamming avoidance has
provided your scientists with some very useful information. But they can't take
the credit for the design—my Creator gets that!
Don't you agree I have a marvelous Designer? Don't you want
to get acquainted with Him?
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