👉 Elasmobranchian is a type of organism in the class Echinodermata. These organisms have a long, slender body with a single gill plate located at the base of the esophagus (oral cavity). The gills are attached to the esophagus and are used for gas exchange. Esmalobranchians include clams, oysters, snails, crabs, sponges, starfish, and sea cucumbers. They have
