If you succeed in finding a live sea urchin—and you can generally do so without very much trouble, by hunting in the pools among the rocks when the tide is out—you will notice that it has a very big mouth, with five perfectly enormous teeth. They are so huge, indeed, that if you had teeth as big, in proportion to your size, they would be about as large as good big carving-knives!
On some parts of the coast sea urchins are eaten as food, being scooped out of their shells with a spoon, just as we eat a boiled egg at breakfast. For this reason they are sometimes known as “sea eggs,” and those who have tried them say that they are very good indeed.
You would hardly think, perhaps, that a sea urchin and a starfish could be related to one another, for they do not look in the least alike. But if you take an urchin which has lost its spines, and examine it carefully, you will see that it is really a kind of rolled-up starfish, and you will be able to count its five rays quite easily.
1. THE SEA URCHIN WITHOUT SPINES.
2. THE SEA URCHIN WITH SPINES.
There is just one more thing that I must tell you about these very curious creatures, and that is that they are very fond of covering themselves all over with small stones, and little bits of broken shell, and tiny pieces of sea-weed, in order that they may not be noticed. They do this in a very odd way. I told you that they have numbers of little sucker-feet, which they poke out through tiny holes in their shells when they are required for use, just as the starfishes do. Well, when they want to disguise themselves, they just push out two or three hundred of these slender sucker-feet between their spines, and take firm hold with them of any small objects that may be lying within reach. In this manner they soon succeed in covering themselves all over, and you might easily look at one of them as it lay at the bottom of a rock-pool without recognising it at all.