Not only does our mystery animal swim around with its mouth open, but that mouth is actually filled with sharp teeth! As a result, many people think this is a fierce, dangerous animal. Some stories say that our mystery animal will attack any person who is foolish enough to swim in waters where they live. Rumor has it that this animal will clamp its teeth onto a man’s arm and hold him down until he drowns.

Honeycomb moray eel. Photo © David McKee/

But if the truth is told, our animal is actually quite shy and will not attack unless it is provoked.
Is our mystery animal a shark? No, not at all. Our animal is long and thin—rather snake-like in appearance. There are over 200 different species of this animal, and they vary in length from 1-10 feet (30 cm – 3 m). Many sharks, as you know, have tall dorsal fins; this animal usually has only a narrow dorsal fin that runs along most of the body’s length.

Is it a fish? Yes, it is—but it belongs to a very distinct group of fish. Because of their snake-like appearance, they are quite unlike most other fish.

Oh! I must have been giving too many hints, Wondernose. You guessed right—our animal is an eel. However, it is not the kind of eel you might see in fresh water. Those are called the common eels, and they’re usually smaller than the eels we’re discussing.

Also, the common eels don’t have a reputation for ferocity like these saltwater eels do. Ever heard of moray eels? That’s the name of our mystery animal. The morays live mostly in tropical seas. Their preferred home is a coral reef. They can easily swim into hiding among the cavities of the reefs.

The trouble is, people like diving in the coral reefs too. Experienced divers tend to watch out for morays, though. It may be true that morays will leave you alone if you leave them alone. But the fact remains that divers have found out what it’s like to have a moray chomp on their hands. Why do they do it?

Well, Wondernose, imagine you’re a moray eel lurking somewhere in a coral cave. Your favorite food is clams, mussels, and other shellfish. Suddenly, before your eyes, a hand reaches down to pick up a nearby clam. Wouldn’t you pounce? Of course you would. You wouldn’t realize that hand is attached to a man. You’d only know that something moved, and it might be good to eat!

Although they like clams, morays will eat just about any animal they can swallow. It’s important, though, that they stay with food they can swallow quite fast. Why? Because morays need to have water flowing in through their mouths and out through their gills. That’s the way they breathe. As long as they’re swallowing, they can’t breathe. It’s like a boy with a bad cold and a stuffed-up nose. Aren’t you glad you can breathe through your nose while you eat, Wondernose?

And now you understand why a moray always seems to be panting. That open mouth is essential to the eel’s survival. He isn’t doing it to scare you at all.

A moray’s head and the forepart of the body are bulkier than the rest of the body. I’ll admit that the big head and the open, toothy mouth do give the moray a fierce appearance.

You wonder if morays have nostrils. Indeed they do. Like most bony fishes, the morays actually have four nostrils, situated on top of the head. The nostrils of some morays stick up like tubes. Others have leaf-like flaps to open and close the nostrils.

Now that’s a good question, Wondernose. If a moray has nostrils, why does it breathe through its mouth? Don’t fish breathe with gills? Well, it seems fish have nostrils mainly for smelling, not for breathing.

Are morays poisonous? Yes, they have poisonous toxins in their skin and mouth, and several species can deliver deadly bites. But they do not have fangs and inject venom like some snakes. If they’re cornered, they act rather like a snake, rearing their heads and lunging forward.

Here’s another trick morays use in trying to escape when they’re caught—they can tie their bodies into knots! Suppose, Wondernose, that you were to catch a moray on your fishing hook. It might throw itself into a knot and sort of climb up the line as it attempts to free itself. Wouldn’t that be something to watch? But you will probably never sit on a coral reef and throw out a fishing line.

Common freshwater eels mostly have drab colors. Morays, by contrast, can be pretty vivid. I’ll leave it to your imagination to picture a zebra moray. The starry moray appears to have stars painted all over its sleek body. Others have vivid spots. With gaping mouths, sharp teeth, and dramatic colorations, I’m not surprised that morays have a reputation for being fierce.