Like all gastropods, the conch is made up of a soft body (mollusk) with a spiral shape and a calcareous exoskeleton (shell), normally of the right-handed type, that is, with an opening located to the right of the axis of the shell if you look at it. from the ventral side and with apex facing upwards.

The mollusc consists of a foot that favors locomotion, the head, the pouch of the viscera and the mantle, which presides over the formation of the shell. The mollusk never separates from the shell, but can stretch out its foot or its head. When threatened it can burrow inside the shell using the operculum as a door to close itself inside or as a defense weapon thanks to its sickle shape.

As mentioned, the head is constituted in the center by a retractable proboscis, at the end of which there is the mouth and which the mollusk can reach out to look for food, and by two tentacles at the end of which there are the eyes bordered in orange (Kronenberg&Berkhout, 1981). When the animal is in extension it is possible to recognize the sex of the animal in proximity of the right tentacle, a black peduncle (penis) in the case of the male, a groove in which to contain the eggs in the case of the female.

Above the foot and around the shell, the mollusk presents the mantle, which has the task of building the shell and keeping it clean and shiny. In fact, the shell is not made up of living tissue, but essentially made up of calcium carbonate (like our bones) for at least ninety percent. It is the mantle that produces the substance from which the shell originates, absorbing calcium from the surrounding environment and transferring it to the mantle and aggregating everything with a texture of conchiolin, an organic substance. The shell consists of three layers. From the outside we have the periostracum, of organic substance, which has the task of protecting the shell, then we have respectively the ostraco and the hypostracum, which constitutes the innermost layer in contact with the mantle.

Development of the mollusk:

To understand how the shell is formed we think of the analogy of a man who builds a circular wall around himself in the shape of a spiral, and as he proceeds with the outer walls he builds it higher and higher. often. In our analogy the man is the mollusk, which is basically constituted by a soft tube that increases its size going from the inside towards the opening of the shell, which has a spiral shape and which as it grows continues to build a shell around himself. In the event that a part is damaged, the mollusk, through the particular substance secreted by the mantle, carries out the repair. As the mollusk grows, and at regular intervals, this creates wider spaces which are the nodules and thorns on the back of the animal, which have the task of giving stability to the shell and not letting it roll in case of sea currents.

Upon reaching sexual maturity, the behavior of the mollusk changes radically. In fact this stops growing in terms of length and size and begins to form a wing-shaped outer lip. From this moment on, the material secreted by the mantle continues to accumulate on the outer lip of the shell, thus continuously increasing in thickness. For this reason, juvenile specimens usually have a light shell and a thin outer lip and the adult ones a heavier shell and thickened outer lip.