arfish! It is lying on the sand, left high and dry by
the waves, for now the tide is low. The Starfish looks limp and
lifeless, its five reddish-coloured "arms" are quite still.
We know it is an animal that lives in the sea, and dies when washed
ashore. But what does it do in the sea? How does it move without legs or
fins? How can it live without a head? Has it a mouth? What does it eat,
and how does it find its food?
Like so many other sea-animals, the Starfish is a puzzle. Some of its
little tricks puzzled clever people until quite lately. But we know most
of its secrets now.
Pass your finger down one of its arms, or rays. It feels rough, being
covered with knobs and prickles. Now turn the Starfish over, and look
carefully at its underside. In the centre, where the five arms meet, is
the animal's mouth. A harmless sort of mouth, you think, too small to be
of much use. Really, it is a terrible mouth, the mouth of an ogre!
We notice a groove down the centre of each ray. But what are those
little moving things which bend this way and that, as if feeling for
something? Now that is exactly what they are doing. They are the feet of
the Starfish. Each tiny foot is really a hollow tube, which can be
pushed out or drawn in. At the tip of each is a powerful sucker, which
acts rather like those leather suckers boys sometimes play with. Suppose
the Starfish wishes to take a walk along the bed of the sea. First, it
pushes out its tube-feet. Each sucker fixes itself to a stone or other
object, and then the animal can draw its body along. You will see
presently that the suckers can do other work too.
Our Starfish will die, however, unless we carry it to a pool. Before
doing so, we must look at the tip of each ray for a small reddish spot.
That is the Starfish's eye. Are those little eyes of much use in helping
the creature to find its dinner? I think not. Most likely the Starfish
_smells_ its way.
If we put the animal on its back in a rock-pool we shall see the
tube-feet at work. Once in the water our Starfish revives, and makes
efforts to right itself. Can it turn over and crawl away?
The little tube-feet come out of their holes and begin to bend about.
Now those near the edge of one "arm" feel the ground. Each tiny sucker
at once takes hold, more and more of them touch the ground as the ray is
turned right side up, and at last the Starfish turns over, and, slowly
but surely, glides away.
[Illustration: COMMON FIVE
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