CHAPTER IX. Sea Anemones

SEA ANEMONES

HOW SEA ANEMONES ARE FORMED

The most beautiful of all the creatures which live in the sea are undoubtedly the Sea Anemones, which are just like living flowers of all sorts of lovely colours. But I do not know why they are called sea “anemones,” for they are much more like asters, or dahlias, or chrysanthemums.

These anemones are made in a very curious way. You will notice, as you look down into a rock-pool, that their soft fleshy arms, or “tentacles,” are all spread out like the petals of a flower. If you touch them, however, they at once come closing in and disappear, so that in two or three moments the creatures look like mere lumps of coloured jelly. But if you wait for a little while they will push out their tentacles again, and spread them just as before.

The fact is that the body of a sea anemone is a kind of double bag. Suppose you take a paper bag, twist up the mouth, and push it downwards, so that the sides of the bag surround it all the way round. You will then have two bags, as it were, one inside the other, the space between the two being filled with air. Now that is just the way in which the body of a sea anemone is formed, with this difference, that the space between the outer bag and the inner one is filled with water. It forms, in fact, a kind of water-jacket.

Next, remember that all those spreading tentacles are really tubes, like the fingers of a glove, closed at the top, but opening at the bottom into this water-jacket. And remember also that the outer walls of the body are formed of very strong muscles. So, you see, when the anemone wants to spread its tentacles, all that it has to do is to contract these muscles. The water is then squeezed up into the tube-like tentacles, which of course expand. When it wants to close them it relaxes the pressure, and the water flows out of the tubes again and back into the water-jacket, so that they all come folding in.

The lower part of an anemone’s body is called the “foot,” and is really a big and strong sucker, by means of which the animal clings so firmly to the surface of a rock or a stone that it almost seems to be growing out of it. But these creatures do not spend the whole of their lives without moving, as oysters and barnacles do. Sometimes they will creep slowly along over the surface of the rock, in order to find a more comfortable situation, or one where they will have a better chance of catching prey. And sometimes they will loose their hold of the rock altogether, rise to the surface of the water, turn upside down, and hollow their bodies in such a way that they form little boats, which can float along over the waves for quite a long distance.

PLATE XLI

THE SMOOTH ANEMONE (1)

This is by far the commonest of all the sea anemones, and you may find it in hundreds and thousands by going down among the rocks when the tide is out, and looking into the pools. You are almost sure to see that their rocky walls are dotted all over with lumps of brown or dark green jelly, some only about as big as peas and some as large as plums. These are Smooth Anemones, with their fleshy feelers, or “tentacles” closed. And just here and there you may see one of them open, and you will notice that all the way round the edge of its body, between the roots of the tentacles, it has a row of little bead-like objects of the most beautiful turquoise blue. For this reason the smooth anemone is sometimes known as the “beadlet.”

You can easily keep these anemones in captivity, for they are very hardy, and are no trouble at all to feed. Indeed, they will go without any food at all for three or four months together, and seem all the better for their long fast. But if you put a tiny dead crab, or a shrimp, or a sandhopper, into the midst of their spreading arms, you will see the tentacles close round it, and push it down into the mouth, which lies just in the very middle. For about forty-eight hours the animal will then remain closed up. But as soon as it has digested its dinner out will come the tentacles again, bringing with them the empty shell of the victim.

Every now and then, like other anemones, this animal changes its skin, and when it leaves its position on the side of a rock-pool and crawls to a new one, it nearly always leaves a cast skin behind it.

1. THE SMOOTH ANEMONE.

2. THE DAISY ANEMONE.]

PLATE XLI

THE DAISY ANEMONE (2)

This is not nearly such a common creature as the smooth anemone, but you may sometimes find it in the rock-pools at low-water on our southern and western coasts. It is pale greyish yellow in colour, and has an odd way of altering its shape from time to time, so that sometimes its body is long and slender, and sometimes it is short and stout, while the disc may be long and narrow one day, and almost round the next. You can always tell it at once, if you should happen to meet with it, by looking at its fleshy feelers, or tentacles, which are marked with rings of grey and white.

PLATE XLII

THE THICK-ARMED ANEMONE (1)

Where the coast is sandy and rocky too this anemone is often rather common. Yet very few people ever see it, because it nearly always fastens itself quite low down on the rocks which border the pools, so that at least half of its body soon becomes covered up with sand. Besides this, it has a great number of very tiny sucker-feet, not unlike those of the starfishes and the sea urchins, and with these it clings to tiny stones and bits of broken shell, which often quite conceal its upper surface, so that one really cannot see the anemone itself at all. But it is quite one of the very handsomest of all the British sea anemones, for when it is fully grown it is over five inches in width; and sometimes it is pearly white in colour, and sometimes it is green, and sometimes it is purple and brown, and sometimes it is crimson, while its tentacles are banded with scarlet and white. These tentacles are rather stout in proportion to their length, and when they are fully spread the animal looks very much like a cactus dahlia.

PLATE XLII

THE SNAKE-LOCKED ANEMONE (2)

This is also one of the prettiest of these very pretty creatures. But it is not in the least like the thick-armed anemone, for instead of having a broad, stout body it has a long slender one; and instead of short, thick tentacles, like the petals of a dahlia, it has a bunch of almost thread-like arms, which really rather remind one of little white snakes. And when they are spread these long arms are hardly ever still, but are always waving about in the water.

1. THE THICK-ARMED ANEMONE.

2. THE SNAKE-LOCKED ANEMONE.]

When the snake-locked anemone closes up, however, you would never know it for the same creature, for it not only draws its long tentacles back into its body and tucks them away out of sight, but contracts the body itself until it is almost flat. Unless you looked very carefully at the rock to which it was clinging you would never notice it at all.

This anemone is not a very common one, and is chiefly found on the rocky coasts of Devonshire and Cornwall. In colour it is almost white.