We all know that fish stories and the tales that fishermen tell are sometimes viewed with a great deal of skepticism. In the world of crustaceans, the facts are so strange that, were they not established as scientific fact and truth -- they would be received as the fiction of a jester.

How amusing it would sound, for example, if a comedian appeared on the stage with his hand bound up, declaring that he had been bitten by a crab while up a tress bird-watching!

What romancer we should thing the man who assured us that he had been gnawed and maimed by crabs when exploring at mountain height? Or that his house had been damaged by myriads of crabs marching right through and over it?

All those things have happened. The old fish related fables which our ancestors believed for centuries seem ludicrous to us now, but the facts about crabs and their kindred relatives are almost as unbelievable as anything the old legends said.

For me, I've seen the ferociousness of crabs both on dives and on land. One of our first trips as a new couple was to Islamorada, Florida where innocently arriving late at night we decided to take a dip in the water. Little did we know that soon we'd be fleeing thousands of little crabs, all intent on biting we intruders. It was a very short swim with crustaceans.

There are no backbones here, no spinal cords. However, we find brain, highly organized nervous tissue, decided evidence of complicated instincts, of affection, of the courage and ferocity we impute to the modern bulldog.

Moreover, there is a history behind the group which inspires a touch of awe.

Its members are so immensely ancient. We find their remains in the earliest rocks, and today, the earth is full of them, more than ten thousand living species, differing widely in size, color, appearance, and habits.

We call them Crustaceans, which means "having a crust," for most of them are covered with armor, an outside skeleton, so to speak.

They inhabit both salt and fresh water, and some species spend most of their lives on land.

The class includes crabs, lobsters, crayfish, shrimps, prawns, sand-hoppers, wood-lice, and water fleas. Additionally, many tiny forms found in the seas and great lakes upon which fishes feed are also family members.

The body of a crustacean is made up of a number of segments. To these segments are attached the legs, the parts which compose the mouth, and the appendages which resemble short claws rather than legs.

In many of the species, the eyes are raised on stalks and can be moved about like lamps on a flexible arm, but there are others where the eyes are not raised, or, if stalked -- are not movable.

The mouth is, of course, different from that of a mammal or any other back boned animal, for in the crabs -- we have an organ made up of three pairs of jaws, mandibles, and maxillae, which are simply modified limbs.

Such a mouth cannot seize its prey like the carnivorous mammal, but it must be fed and stuffed by the powerful pincers.

However, for all that, it is efficient for the work it has to do.

Breathing is by gills, but there are wonderful modifications in species which live mainly ashore. Small appendages near the mouth are kept in constant motion in order to secure a regular current of fresh water for the gills. There are special senses, too, in these quaint-looking little limbs.

With these the crab feels and smells. Wonderful that all these offices should be discharged by limbs enclosed in a hard shell. That shell, by the way, is not like the shell of a periwinkle or an oyster, nor does it match the horn of a bison or the bone of a deer's antlers.

It is somewhat like horn, a special development of that wonderful substance -- chitin, which affords a covering of mail to insects, and lines their interior.

The crab is not born with this coat of mail. It begins its career in an egg attached to the limbs of its mother, and when hatched is but a speck of life enclosed in a though little membrane.

We should never dream, until instructed, that the baby crab is a crab at all, so complete unlike the adult in form is it -- with a streaming long "beak," a sort of cap over its back, and an eye out of all proportion to the diminutive body.

If it escapes the peril of other crabs and the fishes and sea birds, our little crab slowly comes into possession of its first shell. That has to be changed repeatedly, much more often than the skin of a caterpillar is changed.

For, like the caterpillar, the crab cannot grow without exchanging its outer covering for a new one. When the shell is fully filled, the little crab finds its mail split down the back.

Tightly fitted in as he is at every joint, he withdraws each leg in turn from the shell, like a boy taking off his shoes. Then, he liberates the body, one half at a time. He is a helpless little fellow in danger lest some hungry enemy may come up and find him a tender, tempting mouthful.

The crab must lurk in secret places till he is newly mailed and fit to face the world and its dangers. Very poorly he must feel at such times, for not only does his entire shell come off, but he even molts the coats of his stomach.

We must suppose the crab's sense of smell to be acute, for, unlike the lobster, which likes its food "high," the crab will take nothing but fresh meat, unless sorely pressed.

Therefore, as its watery home must be rather gloomy, we take it that its "nose" must be very sensitive to guide it to the bait to which it scurries. It will eat fresh meat. It will catch and eat fish.

Hermit crabs are born with the back part of their bodies quite defenseless, though the fore part has its mail, and the claws are as strong as any other crab species. They fear to be pinched in halves, so they have to hunt for homes.

Whelk shells are generally most desired. They prefer an empty one, but driven to an extremity, they will attack the owner, tear it to pieces, and then take possession of the liberated shell. Hermit crabs have their housing problems as permanent and perplexing as our own.

Once in possession of the borrowed home, they insert their tails, which curl around and fit into the whorls of the fortress, while some of their foot-like appendages fasten like pinches to the walls.

The hermit crab in his shell must have an anemone on it, and the anemone is willing. With the hermit half in and half out, and an anemone mounted on top, together they go roaming in search of food.

The anemone stings the enemy of the hermit crab. The hermit crab is a pack-horse carrying the anemone to food. It is one of the most marvelous partnerships in the wilds of the sea.

An anemone is one of the lowest of animals, yet it has this extraordinary understanding with the hermit crab. If we wish to dislodge an anemone from a shell, we must tear the lovely little monster to pieces. However, when the crab has grown and must find a larger shell, he dismounts the anemone, takes it with him, and mounts it on the new one.

How can we account for such agreement between creatures so low in the scale of existence?