GENERAL HISTOLOGY

Detailed explanation-1: -1. Madreporite or sieve plate: a small, smooth plate, at the entrance of the sea star’s water vascular system, through which the sea star takes in sea water. It’s located on the aboral side of the sea star, slightly off the center.

Detailed explanation-2: -If you’re still not sure, look for the location of the madreporite, also known as the sieve plate. This round, specialized plate allows water to enter the water vascular system. In sea stars, it’s located on the “top” (or aboral, meaning opposite of the side of the mouth).

Detailed explanation-3: -The spiny upper surface covering the species is called the aboral or dorsal surface.

Detailed explanation-4: -The sea star’s skeleton, like the sea urchin’s, is an endoskeleton consisting of small plates of calcium carbonate embedded in the epidermis. These plates, called ossicles, are much smaller than those of sea urchins.

Detailed explanation-5: -The top side of the sea star is called the aboral side, because it’s opposite the oral side. The bumpy-skinned aboral side is covered with loads of tiny pinchers called pedicellariae that help clean the rough surface.