Aboral
Aboral (ab-o’-ral) refers to the side of an invertebrate opposite to or directed away from its mouth. This term is often used to describe the abactinal surface, the part of an echinoderm’s theca or plate, or the structures on it, which are opposite to the structures that bear the mouth and proximal ends of the ambulacral grooves. In the case of an edrioasteroid, the aboral part is directed downward.
Aboral (ab-o’-ral) refers to the side of an invertebrate opposite to or directed away from its mouth. This term is often used to describe the abactinal surface, the part of an echinoderm’s theca or plate, or the structures on it, which are opposite to the structures that bear the mouth and proximal ends of the ambulacral grooves. In the case of an edrioasteroid, the aboral part is directed downward.