Holiday Shore  by Edith M. Patch

Shore Snails

The Moon Snail's Meal

M ANY empty snail shells are washed up by the waves and lie on Holiday Shore. Some of them have long, sharp points. Others are blunt with ridges on them. There are still others that are nearly round and rather smooth. They are white or blue-gray or brownish and the largest are four inches long.

These large, smooth shells were built by moon snails. Moon snails never crawl on the rocks; but if you look closely on Holiday Beach you may see the tip of a shell sticking up through the sand. As you watch, it moves. The moon snail is able to crawl, even when it is buried in sand.

A Moon Snail

Would you like to see a moon snail crawl? Then dig one out of the sand with your spade and put him in a shady tide pool. At first he will lie quite still, with the mouth of his shell closed by a brown door. Soon that door will begin to open. If nothing scares him, the moon snail comes out ready to take a walk.

Did you ever suppose such a big body could come out of this pretty shell? It rolls out and begins to spread. Soon the shell almost disappears in this great mass of pearly flesh.

But not all of this huge body is flesh. A great deal of it is water that the snail pumped into his body while he was getting out of his shell. When you disturbed him a little while ago by digging him from the sand, he squeezed most of the water out and so could tuck his body away.

Taste guides him to some fish meat lying on the stones. Hermit crabs have been feasting there, tearing off bits with their claws; but they run away when the moon snail comes near. There is nothing to interfere with him, so he spreads his big body over the fish and settles down for a good meal.

The last time the moon snail had something to eat, he was buried in the sand of Holiday Shore. As he crawled through it he met a clam, which quickly closed its hard white shell.

Did that discourage the moon snail? Not at all. He wrapped his body around the clam and stuck out his horny, sharp tongue. As he moved it, his tongue bored a neat hole through the shell of the clam. Then the moon snail reached in with a pair of sharp jaws and began to eat the juicy clam meat. In an hour nothing was left but the shell, with the hole that the moon snail's tongue had bored.

If you look at the empty shells on Holiday Beach, you will find many that show just such holes. Some are the shells of the purple mussels that lived on the rocks near Holiday Point. Others are the shells of "hard-shell" or "soft-shell" clams that burrowed in the sand near the shore. Still others are the shells of partly grown moon snails.

Some day you may visit an ancient shore in Virginia or Maryland. Though once a pretty beach, it now is a bank of clay and sand. Look at the gullies where rain water has run down. You will find the fossil shells of oysters, clams, and snails that lived millions of years ago. Some of them will be moon-snail shells. Then look carefully at your fossil clams. You will find that many show neat, round holes like those drilled by the moon snails on Holiday Shore.

Moon snails have lived in the sea for almost two hundred million years. Through all that time they have crawled in the sand, hunting snails and clams. During all those years they have been boring shells with their rough tongues and getting the good food inside with their sharp jaws.

Perhaps, while playing on Holiday Shore, you have found broken, leathery rings whose surfaces were covered with sand. Though you may not have known it, each of those rings held eggs laid by a mother moon snail.

You can tell Mother Moon Snail from Father only because she is larger than he. Her shell is rounded and smooth like his. She crawls as he does. She eats with the same table manners.

One warm summer day, Mother Moon Snail began to lay her eggs. Each time she laid a dozen or fifteen, she shut them up in a clear shiny capsule. She did this a great many times. Then she glued all the capsules into a ribbon that looked like crinkly celluloid. Next she covered one side of the ribbon with sand that she found near by. As she worked, she rolled the sheet around her body. In this way she shaped the sheet into a broad ring, like a broken bowl without any bottom.

After putting about half a million eggs into the capsules of that sandy ring, Mother Moon Snail left them lying on the sand and crawled off to hunt a mussel or a clam.

Mother Moon Snail left about half a million eggs in this sandy ring.

For a month the egg-ring was washed here and there by the water. At last, when the eggs were ready to hatch, the ring broke into tiny bits. A great many baby snails hatched from the eggs that were in each bit, and they all went out to float in Holiday Bay.

These infant snails were so small they could be seen only with a microscope. Like little starfish, they drifted where waves and currents carried them. Some got close to rocks and were eaten by hungry barnacles and little animals that look like plants. Hundreds were sucked into the mouths of clams. Thousands were devoured by the purple mussels that lived near Holiday Point.

It is, as you may see, a good thing that Mother Moon Snail laid as many as the half million eggs or there would not have been enough babies left to grow into strong, hungry snails.

The whelk does not crawl in the sand. She lives on rocks and on Holiday Cliff. Twice a day the tide goes down and leaves her high and dry. But she does not mind. She just sits down, shuts her shell, and waits for the water to come again.

Do you think that all whelk shells of the same kind should look alike? Perhaps they should—but they don't. Some are wrinkled and some are almost smooth; some are sharp and others are blunt; some are white and others are yellow or even brown. A few have orange stripes on coarse ruffles of shell.

The whelk puts her eggs in little vases which she glues tightly to the rock. She puts about four hundred eggs in each vase. Even before they leave their vase the baby whelks are hungry. There is nothing else for food in the vase so some of the tiny whelks eat the others. By the time they are ready to leave the vase, there may not be more than a dozen to come out. They hide in cracks for a while until they grow big and strong enough to go hunting. Then they feed on mussel or barnacle meat, which they get by boring through the shells of these creatures.

Whelks put their eggs in vases which they glue tightly to the rock.

Periwinkles are the commonest snails on Holiday Shore.

But what happens to them if they cannot hide?

Look at that big bare rock. The sun has dried it and made it warm, yet many periwinkles remain there. When the tide went out, each periwinkle fastened its shell to the rock with a bit of glue it made in its body. Then it tucked itself away in the shell and settled down for a nap until the next tide. If they really had to do so, they could sleep this way for days without touching water.

Three kinds of periwinkles live on Holiday Shore. One is yellow. Another is green. The third and largest has a gray shell with dark stripes.

When white people first visited this part of the coast, they did not find any of these gray periwinkles. It was not until about sixty years ago that these snails entered Holiday Bay.

How did they get here? They crawled and drifted from Canada, where they probably were carried by ships from Europe. Each year they came farther and farther south. Now they are the commonest of all snails that dwell on Holiday Shore.

These periwinkles thrive best on rocks where the waves wash over them twice every day. Those that stay in muddy bays never are so large and smooth as the periwinkles of Holiday Shore.

You will see the limpet's big flat foot.

These are hat-shells, or limpets. They do not live below low-tide level. It does them no harm to get dry. When the tide is high they crawl slowly about, eating tiny plants. When the tide begins to lower, or ebb, each limpet crawls back to the place from which it started. Every limpet on Holiday Shore has its own special home.

There are different kinds of limpets. Some are small and rather smooth. Others have thick white shells that are rough. On the shore near Monterey, California, lives the largest limpet of all. It is three or four inches long, with a hole at its top instead of a peak. Its black body covers most of its shell, which is a very pretty light brown. People call it the keyhole limpet.

The keyhole limpet, the largest of all hat‑shells.

The red abalone has a big rough shell. Its outer surface is a dark brick red. Old shells generally are covered with plants, moss animals, and tubes built by worms. From the number of things growing on their shells, you can tell that the red abalones live in deeper water than their smaller, black relatives do.

Moss animals, plants, and worms grow on the shell of the red abalone.

The peacock abalone is the largest of all. Outside it looks worn and weather-beaten; but its inside colors are brighter than those of any rainbow, as you can see when the body is taken from the shell. There shine blue, green, and red—like the colors on the feathers of a peacock's tail.

An abalone resembles one-half of a clam shell, yet it really belongs to the snail group. Look closely and you will see the coil in its shell. Like the limpet, the abalone crawls about eating plants, holding tightly to the rock if alarmed. Since its big muscles are good to eat, thousands of abalones are killed every year and sold in restaurants as "abalone steaks."

Two such creatures live on Holiday Shore. The larger of these is about an inch long. It looks much like a fat worm, mottled with white, yellow, and blue. You may not see it unless you hunt when the tide is very low, for it hides among the rocks.

Its smaller relative lives along rocks, seaweeds and eel-grass leaves. It is slender and pretty, with many waving plumes that are orange, purple, and blue. It lays eggs in long strings which it hangs from rocks and plants, or coils on flat stones.

Many relatives of these shell-less snails live on the Pacific coast. Some are small like those in the East, but others are large. One has very bright yellow colors, with rich brown spots. It hides among seaweeds and rocks and lays long ribbons filled with eggs. If you catch one at just the right time, it will lay a beautiful salmon-pink ribbon of eggs in your aquarium.

When you wade in Southern California bays, you will see many big brown snails whose shells are so small they do not show. Their common name is sea hares, though they never act like rabbits, or hares. Instead of hopping, they crawl on the sand, leaving trails of slime behind them. Sometimes they open big flaps of skin and drift away with the tide. When they have gone far enough, they catch hold of eel-grass leaves to keep from floating out to sea.

Sea Hares of California