|
Snails are mollusks, which means a kind of animal without backbones. There are two basic kinds of snails: the first includes the snails which have shells; the second, those which are covered merely by a thin mantle of the second group are usually called “slugs.”
All the members of this division of mollusks have one large foot on the underside. Therefore, they are called “gastropods,” or stomach feet. This division also includes the large whelks of the ocean and the periwinkles. The ocean snail’ measures about 25 millimeters in the shell.
All these creatures are equipped with one or two pairs of feelers. They have a pair of eyes, which may be at the end of the feelers or at their base, and a mouth. The mouth often extends into a trunk. |
|
|
At its end there are sharp teeth with which the snail can scrape off pieces of plants.
Some snails eat animal food. The oyster drill, for example, is a yellow-shelled sea snail which drills into oyster shells and feasts on their flesh.
Snails and slugs breathe either by means of single lungs or by gills. Their shells, which are often beautifully formed, are secreted, or given off, by the mantle. They are usually built up coil after coil, as the animal grows.
Most snails lay eggs. Some lay many small ones; others lay few but very large eggs. In a few species, however, the young are born alive! So you can see that this little creature is quite an interesting one to study. By the way, have you ever eaten snails? In many countries, the flesh of garden snails, of whelks, and periwinkles is considered a delicious food.
|
|
