GENERAL HISTOLOGY

Detailed explanation-1: -Unlike other groups of echinoderms, sea cucumbers have no large plates or ossicles forming a rigid skeleton. Their skeletal structures are microscopic spicules embedded in the animal’s skin.

Detailed explanation-2: -In the case of sea cucumbers, the internal skeleton takes the form of tiny particles called ossicles, embedded in the outer skin. Taxonomists can identify sea cucumbers by examining the shape of their skin ossicles under a light microscope.

Detailed explanation-3: -Sea cucumbers have also ‘lost’ the bulky endoskeleton prominent in other echinoderm groups. The skin is leathery, and remnants of the endoskeleton in the form of microscopic bony plates are embedded inside the skin tissue.

Detailed explanation-4: -Ossicles are small pieces of calcified material that form part of the skeleton of a sea cucumber. A morphological approach is simpler and easier to apply compared with a genetic approach. The common shapes of ossicles in the sea cucumber body include table, button, rod, anchor, perforated plate and roxette.

Detailed explanation-5: -Echinoderms possess a unique internal skeleton (or endoskeleton) composed of thousands to millions of calcium carbonate components known as ossicles. Similar to a complicated 3-D puzzle, these pieces are infused with tissue and covered by an epidermis, or skin like covering.