The New Jersey Shoreline

As darkness tenderly drapes itself over Delaware Bay, a soft breeze breaks the lingering heat of a blistering summer day.

Clack-clack-clack.

At first, you hear only a rhythmic clattering, like conch shells clicking in the gentle surf.

Clack-clack.

But if you crouch low near the water's edge, you can see in the shallows of $ the high tide an awesome spectacle that has been recurring since before Tyrannosaurus rex roamed the earth: the mating dance of the horseshoe crab, one of nature's ugliest and kinkiest creatures.

Their annual spawning is a sight so bizarre that it draws voyeurs from distant lands to the sandy shores some twelve miles northwest of Cape May, N.J. Lugging cameras, British journalists fly here to film the fecund scene. Japanese scientists gawk at the colossal display of concupiscence. American entrepreneurs profit from it. Biologists study it, and schoolchildren puzzle over it. Oblivious, the crabs just do their primal thing.

With the full-moon tides each May and June, tens of thousands of crabs swarm ashore like magic. Skittering shadows the size of an elephant's hoof, they mingle in piles along the water's edge. The sandy shoreline becomes the site of a vast, squabbling, tumultuous crab orgy.

Before hitting the beach, some lucky crabs, whose tough, circular shells conjure images of tiny oceangoing Darth Vaders, pair up, with the smaller male crabs locking themselves atop the females' spiny shells with special pincers. For many less fortunate males, who vastly outnumber the females, the frenzy is more like a wretched high school dance: they form a stag line on the beach. Then, when a female, bearing a suitor on her back, wallows up and begins to burrow in the sand where she will lay about 4,000 eggs, as many as 15 lusty males struggle in the waves to pile on. All the males, their long spiny tails wiggling like primeval Excaliburs, try to milt (scientific politesse for fertilize) her eggs and so continue their brutish lineage for another 200,000 millenniums.

"It's real prehistoric," says Fordham University biologist Mark Botton, a New York Giants cap perched on his curly black hair, as he ambles down the beach just feet from the frenzy. "We call it a random-collision process," he says, describing the orgiastic mating ritual of the world's largest population of horseshoe crabs. "It's just like billiard balls."

Swatting at a bug on his neck, Botton, who has studied the crab for twelve years, climbs the steps to a shoreline lab, where he is running an experiment to create horseshoe-crab babies in petri dishes. Directing a visitor to a microscope, he points out a wiggling, green horseshoe-crab embryo about the size of a large pinhead. "The little ones are cute," he concedes. But the parents? "When they get this big," he says, "it's just difficult to get emotionally attached."

Which is a biologist's way of saying horseshoe crabs are repulsive. The scientific name, Limulus polyphemus, loosely translates as "slant-eyed Cyclops." But horseshoe crabs are not really crabs at all. They are arthropods, distant relatives of scorpions and spiders.