AP BIOLOGY

Detailed explanation-1: -The water vascular system of echinoderms is essentially a system of fluid-filled canals that extend along each of the body regions and have many external projections called tube feet. There are several functions of the system, one of which is to use water pressure to mediate movement and assist in feeding.

Detailed explanation-2: -Echinoderms are characterized by a unique coelomic water vascular system. This is a hydraulically controlled system consisting of a circumoral ring around the esophogus with connecting radial canals each leading to an ambulacrum.

Detailed explanation-3: -Define Echinoderm. Invertebrates with an internal skeleton and a system of fluid-filled tubes called a water vascular system. Examples: sea cucumbers, sea starts, sea urchins, and sand dollars.

Detailed explanation-4: -The bodies of echinoderms are made of hard calcium-based plates that are often spiny and always covered by a thin skin. The echinoderm skeleton is thus on the inside-called an endoskeleton.

Detailed explanation-5: -All echinoderms have a water-vascular system, a set of water-filled canals branching from a ring canal that encircles the gut. The canals lead to podia, or tube feet, which are sucker-like appendages that the echinoderm can use to move, grip the substrate, or manipulate objects.