Animals, of Which There Are Numbers on Sand and Rock
One Who Wanders Open-Eyed May Find a Multitude of Interesting Objects Cast up by the Waves or Left Behind by the Ebb Tide
By A. Hyatt Verrill
The Christian Science Monitor June 30, 1937; researched by Alan Schenker, digitized by Doug Frizzle, October 2011.
Few persons realize what a teeming life inhabits our shores, whether the shores are sandy beaches, mud flats or rocky ledges. Once they learn where and how to discover this multitude of unsuspected animation, they are not only amazed at the great variety of creatures, but find many of them most interesting and strange. In very many cases, too, the smaller, less conspicuous animals prove more interesting, and often more remarkable, than the larger, more obvious, and hence more familiar forms of shore life.
Wherever you wander along a beach you will find the remains of various marine animals cast up by tides or waves. Aside from the empty sea shells, there will be the carapaces of crabs, lobsters’ claws, dried shrimp, extinct sea urchins and sand dollars, an occasional starfish, and various sponges. While we usually associate sponges with tropical seas, there are a number of species inhabiting the shoal waters of the New England coast. In many places the most conspicuous creatures cast up by the sea are the big king crabs or horse-foot crabs, or, rather, their cast-off shells, for only rarely is a live horse-foot crab left stranded by the outgoing tide.
There will certainly be a number of strange objects which will be a puzzle to most persons. Such as the squarish, black, rubbery things with slender stems or filaments extending from each corner. Probably these have proved a greater puzzle to visitors to the seashore than any other things cast up by the tides. But there is nothing mysterious about them, for they are the egg cases of the common skates or of small sharks. Those of the skates are the most abundant and may be recognized by the fairly short, almost straight filaments, whereas the appendages of the sharks' egg cases are long and usually are twisted or curled. In both cases the capsules are attached to eel-grass or seaweeds by the filaments, and after the young have emerged via a slit in one end the empty capsules become detached and are washed ashore.
Other puzzles are odd strings of thick, crinkled disks, dull yellow or horn color, which at first sight appear like the exaggerated rattles of rattlesnakes, a similarity which is enhanced by the fact that when shaken they emit a rattling sound. These are the egg cases of the common "winkle," "conk," or "whelk," as the shell is variously called. Often, if the disks are opened, the tiny baby shells will be found within, while close examination will reveal the little apertures through which other young shells have safely emerged. All of these objects, with many others, may be found almost anywhere by anyone strolling along the shore.
Hidden from casual sight in and under the windrows of seaweed, kelp and eelgrass, are innumerable creatures. Of all the marine animals, the most familiar are the shells, for not only are they the most numerous, but also they are the most beautiful, and resist the wear and tear of waves and weather. In many places they are piled in mounds and deep rows for miles along the shore, and in some places the beaches are composed wholly of sea shells. As a rule, however, the shells cast up on the beaches are badly weathered, worn and broken, and have lost their original colors. And while an empty shell may be very delicate and beautiful, yet it tells us nothing of the strange habits and life of the animal that once dwelt within it.
At first glance you may think that the pool holds little of interest. Seaweeds, rockweed and barnacles cover the rocks. Here and there clusters of mussels may be seen, and "periwinkle" shells and a few "snails" move slowly about. But presently you will discover that the rocky sides and pebbly or sandy bottom of the pool fairly teem with life. Half-hidden amid the weeds or in the crevices of the stone, are several starfish, some dull reddish or brown, others lilac, purple or even orange, for the common starfish varies greatly in color. Many of the shells prove to be occupied by the droll little hermit crabs. A half-transparent shrimp darts suddenly from its hiding place and vanishes like a wraith in another spot. A bit of the mottled, gray bottom comes most amazingly to life and reveals itself as a little scuttling crab.
A flower-like object protruding from a crevice attracts attention and you discover it is a delicate sea anemone with rose-pink tentacles like petals of a dahlia. And as your eyes become accustomed to the surroundings and take in the details, you will find marine worms with soft, leathery crowns of rose, orange and crimson waving above their snug retreats, with perhaps a serpent starfish, looking like a long-legged spider, as it crawls about. There will be limpits clinging with their proverbial tenacity to the rocks. Among the rock-weed you will discover beautiful golden-yellow and olive-green nerita shells. You will be attracted by a little patch of vivid scarlet and will find it a sponge, and wherever the sunlight strikes downward through the limpid water the Irish moss will glow with shimmering, iridescent hues.
To study and observe life in a tide pool is similar in a way to studying wild life in a forest. At first you see little, but gradually you notice more and more, and just as you may find a wealth of very interesting forms of life by turning over stones or logs, or by raking over dead leaves or examining the bark and leaves of trees and bushes in the woods, so by carefully lifting bits of debris from the bottom of the pool, by parting the masses of rockweed and Irish moss, and by searching the crevices of the rocks, you will find a teeming community of marine life you never suspected. Perhaps you may feel that these little creatures are not particularly interesting: that a snail is just a snail, a starfish merely a starfish, a crab only a crab, and that little may be learned by watching them. But, if so, you are vastly mistaken. The dull-colored, ridged shell crawling over the oyster shell is equipped with a marvelous drill with which it can bore deep holes in the hardest rocks.
The limpits are provided by nature with perfect vacuum cups. If you watch the nervous, scurrying hermit crabs, and are lucky enough to see the little chaps house hunting, you will be fascinated by their almost human actions in their anxiety to select just the right apartment to suit their needs. Moreover, many of the hermits decorate their temporary homes with flower gardens, and by planting bits of living seaweeds, sponges and other plant-like growths upon their shells, they appear like bits of their surroundings and are perfectly camouflaged until they move about. Some species even carry living sea anemones upon their houses and when they move to larger quarters they carefully move their companions to the new home.
So close is this strange partnership and for so long has it been established that there are certain species of the sea anemones and hermit crabs that do not survive if separated. All of the crabs seem to be sociable chaps fond of having chums, and the common spider crabs, which are the ugliest and clumsiest of creatures, are very fond of sharing their lives with other animals. Not only do they permit sea anemones to grow upon their backs and claws, but they even transplant sponges and other marine growths to beds of mud upon their hard and spiny armor. These are carefully tended and pruned, until in course of time they form an effectual concealment as the crabs lie, half buried, in the mud.
Perhaps the most interesting feature of seashore life is the manner in which the denizens of the tide pools play a game of hide-and-seek. The olive and yellow snails among the rockweed "bladders" seem bits of the plants themselves. The rough, brown and gray limpits are scarcely distinguishable from the irregular surface of the wave-worn rock. The mottled crab in the gravel and sand is a wonderful example of nature's camouflage, as are the little "blenny" fishes with their frog-like eyes and foot-like fins, which are scarcely distinguishable from the sand upon which they rest.
Interesting as all these creatures are, yet many of the more commonly seen, everyday animals, which are usually passed by unnoticed, are fully as interesting. In fact, the more you study and observe the familiar denizens of our shores and tide pools, the more truly remarkable and interesting they seem. Even the lowly and obnoxious barnacles are most curious creatures, for, despite their shell-like appearance, they are really crustaceans, related to the crabs and lobsters. Like these, they swim freely about when young, but, at a certain stage of their growth, they settle down, attach themselves to some solid object and develop hard, jointed shells, within which they dwell for the rest of their lives.
One great attraction of the tide pool is that life within it varies with every tide. Each time the water recedes it leaves fresh creatures trapped within the pool, and one never knows what strange, new creatures one may discover, although there are certain members of the little community who never change—the oldest inhabitants, as one might call them—who have found their particular pool the most desirable of homes, and live on, placidly and contentedly, until some terrific storm or some arch enemy or an ardent naturalist puts an end to their existence.
But there is always the chance that when you visit the pool at low tide you may find that some new and unexpected inhabitant has "moved in." It may be a slender-bodied, bold-eyed squid, with its 10 sucker-clad tentacles; some good-sized fish, such as a grotesque sculpin or a gorgeous orange-and-red sea robin with huge, wing-like fins and funny, fleshy, feet-like feelers; or, again, it may be a delicate, phantasmal jellyfish or perhaps a scallop, with its row of brilliant blue eyes, a true marine acrobat, who will amaze you by leaping upward for two feet or more and will swim with astonishing speed. In fact, a really good-tide pool is a constant source of interest and surprises, a real "grab bag" of marine life: nature's own aquarium.