Snails get their shells by building them themselves using a specialized organ called the mantle. The mantle secretes layers of calcium carbonate, which crystallize and harden to form the shell. This process begins even before the snail hatches, as the embryonic shell (called the protoconch) starts developing during the gestation phase inside the egg. When baby snails hatch, they already have a thin, fragile shell that grows thicker and larger as they mature
. The shell grows by the mantle adding new layers of calcium carbonate at the shell's opening edge, allowing the shell to coil and expand in size as the snail grows. The shell is composed mainly of calcium carbonate with some proteins, and it becomes more solid and durable over time. Snails also need to consume calcium-rich foods and sometimes even their eggshells or soil to maintain and strengthen their shells
. In summary:
- Snails produce their own shells via the mantle organ.
- The shell is made primarily of calcium carbonate.
- Shell growth starts before hatching and continues throughout the snail's life.
- Calcium intake from diet or environment is essential for shell development and repair
