When strolling on the sands of a beach, many people like to admire and catch shells brought by the waves.
These shells come in many different sizes, shapes and colors. They often become costume jewelry, small ornaments, or even elements of a collection.
Mollusks have a fragile composition, are soft-bodied animals, but most of them have a shell that protects the body. In this group we find the snail, the shellfish and the oyster. There are also those who have the inner and small shell, such as squid, and those who have no shell, such as octopus and slug, among other examples.
Oyster shell protects from predators, dissection etc.
THE shell It is important to protect these animals and prevent water loss. It is produced by glands located under the skin, a region called the cloak.
She is not a living part of the clam's body; As the animal grows in size, new material is added to the shell, which may vary in shape and size and consist of one or more pieces.
Where the mollusks live
You can find clams in the sea, in fresh water and on land. For example: the snail and slug are in garden beds, garden, finally, where there is vegetation and the soil is very damp after a good rain; are also about aquatic plants in lakes, riverside etc.
The great marine snail lives crawling on rocks or sands at the bottom of the sea. On the other hand, oysters and shellfish settle on rocks on the coast, while squid and octopus swim freely in marine waters.
At a time when there was still no life in the terrestrial environment, mollusks - with their protective shell - already inhabited the seas. The sea snail is one of the species that has 500 million years of history. So it existed a few million years ago before fish came into the sea. Fossils reveal that these beings, now small, were in the past much larger because there is a 2.5-meter fossil shell.
The body of mollusks
As we have seen, mollusks have a soft body. Your skin produces a viscous discharge, also known as mucus, which makes it easier for you to move around tree trunks and rough stones without hurting your body.
The body of this type of animal is composed of: head, foot and visceral mass. The visceral mass lies within the shell and comprises the digestive and reproductive systems.