Echinodermata Phylum
Sea stars (starfishes), sea urchins and sand dollars, brittle stars, sea cucumbers, and sea lilies are all members of Phylum Echinoderrnata. Many adult echinoderins are easily recognized by their 5-part (pentamerous) radial symmetry. -the anus is formed from the blastopore while the mouth is formed from a second embryonic opening.
Another characteristic is a derived endoskeleton. It is made up of many small plates, which may be separate into a rigid framework or test In many echinoderins, the skeletal plates bear protruding spines. Perhaps the most unique characteristic of echinoderms is the water-vascular system consisting of nwnerous water-filled tubes ending in a large number of tube feet. The water-vascular system is formed from the coelom during embryonic development and is important in locomotion, food handling and attachment.
Another characteristic is a derived endoskeleton. It is made up of many small plates, which may be separate into a rigid framework or test In many echinoderins, the skeletal plates bear protruding spines. Perhaps the most unique characteristic of echinoderms is the water-vascular system consisting of nwnerous water-filled tubes ending in a large number of tube feet. The water-vascular system is formed from the coelom during embryonic development and is important in locomotion, food handling and attachment.