GENERAL HISTOLOGY

Detailed explanation-1: -Echinoderms are exclusively marine organisms with spiny bodies. They have an endoskeleton rich in calcium, basically made of calcareous ossicles . Ossicles are structures embedded into the body walls. They provide rigidity and protection to the body.

Detailed explanation-2: -Echinoderms have a skeleton composed of numerous plates of mineral calcium carbonate (calcite).

Detailed explanation-3: -Echinoderms also have calcium carbonate endoskeletons, ranging from microscopic spicules in sea cucumbers to visible plates in sea stars and urchins.

Detailed explanation-4: -Beneath a starfish’s skin lies a skeleton made of pebbly growths, called ossicles, which mostly consist of the mineral calcite. Calcite is usually fragile, and even more so when it is porous.

Detailed explanation-5: -The Phylum Echinodermata doesn’t always have spiny skin, or a spiny surface, but these animals do all share a calcium carbonate internal skeleton, or endoskeleton.