THIS IS AN EEL.    Just an ordinary eel.    But even ordinary eels are extraordinary. In fact, even ordinary eels are animal superheroes.    Did I hear you say, "But aren't eels just long, slippery, slimy fishy-things that . . . hmm . . . Is there anything more to know?"    You bet your buttons there is! Imagine this: While this eel was just a baby half as big as your pinkie finger, she swam 300 million times the length of her body. If I'm doing my math right, and if you're about four feet tall, that's the same as you traveling all the way to the moon !   "Impossible!" you say.    I say, "You don't know eels."    But you will. Excerpted from Eels by Rachel Poliquin, Nicholas John Frith All rights reserved by the original copyright owners. Excerpts are provided for display purposes only and may not be reproduced, reprinted or distributed without the written permission of the publisher.