EVERYDAY SCIENCE

Detailed explanation-1: -This shell is secreted by a soft, spongy layer called mantle that lies over the visceral hump, also called the visceral mass. The shell is calcareous as it is made up of calcium carbonate.

Detailed explanation-2: -A mantle, a highly modified epidermis that covers and protects the soft body. In most species, the mantle also secretes a shell of calcium carbonate.

Detailed explanation-3: -Molluscan shellfish typically have a hard shell, made up of calcium carbonate, as aragonite or calcite, deposited within an organic matrix. The shell is secreted by the mantle or epidermis, which underlies it and surrounds the body.

Detailed explanation-4: -Two unique features of mollusks are the mantle and radula (see Figure above). The mantle is a layer of tissue that lies between the shell and the body. It secretes calcium carbonate to form the shell. It forms a cavity, called the mantle cav ity, between the mantle and the body.

Detailed explanation-5: -The molluscan shell forms externally at the interface of animal and environment, and involves controlled deposition of calcium carbonate within a framework of macromolecules that are secreted from the dorsal mantle epithelium.