GENERAL HISTOLOGY

Detailed explanation-1: -The surface of the body of an echinoderm, where the mouth is situated is called the oral surface, which is usually on the ventral side (bottom of animals like starfish), while the opposite surface is called the aboral surface, where the anus is situated.

Detailed explanation-2: -In the echinoderms there are two surfaces. One is the oral surface, where the mouth is and the tube feet project. The tube feet on the oral surface are limited to distinct regions called the ambulacral regions. The other surface is the aboral, which typically contains the anal opening of the digestive system.

Detailed explanation-3: -The body is divided into a central disk from which radiate five arms. The principal body axis, and the axis of symmetry, is the short oral-aboral axis, which passes vertically through the center of the disk. The animal’s pale lower side is the oral surface and the dark upper side is the aboral surface.

Detailed explanation-4: -All echinoderms have mouths. They have to eat just like you and I. Their very tiny mouth is located on the underside of the animal. Usually sea stars eat small pieces of food they find on the ocean bottom.

Detailed explanation-5: -The mouth in starfish is present on the oral (lower, ventral) surface and anus is on aboral (upper, dorsal) surface respectively.