What Am I?

I saw this creature Sunday during my second short weekend hike in Back Bay National Wildlife Refuge.  Unlike some of the other animals that I have featured in my "What Am I?" series, this one should be pretty easy to figure out.

Your first clue in this piece of cake -
I'll tell you upfront - I'm a snake!

And here is one more clue for you:
I have not just one name but two

Far from water, I'll rarely be
(but fresh water, not in the sea)

I live in marsh, lake, or river
Seeing me might make you shiver

Despite my name, I'm not a shoe
You wear to get to your canoe

I'll eat turtles, frogs, birds, and fish,
And small mammals, as I might wish

Injecting venom with fangs hollow
The prey's mine with one big swallow

In my mouth you'll find no cotton
But should I bite, you'll feel rotten

You got this one, right?
Scroll
D
O
W
N
for the
answer....

I am an eastern cottonmouth
Residing only in the south

I would not have seen this guy off the trail had not a sharp-eyed naturalist pointed him out to me.  The snake was about 12 to 15 feet away and floating in water.  This photo was taken with my camera's maximum optical zoom - about five power.  I wish I had my Sony with me.  See him?  He is dead center.

I zoomed in digitally for this shot.  You can see his pattern pretty well.  I'd forgotten that cottonmouths, also known as water moccasins, have a wide variability in their color and patterns.  The very large cottonmouth that I saw just meters from this same spot a few years ago was darker (and also about as big around as a large man's arm).

It was a thrill to see this snake, which would be very dangerous to pick up.  Best to leave them alone.