Phylum Echinodermata

Main Characteristics

• Marine animals, with unsegmented body.
• Head absent, body surface marked with 5 radiating areas.
• Radial symmetry.
• Endoskeleton of dermal calcareous ossicles with spines.
• Movement by tube feet.
• Sexes usually separate.
• Regeneration of lost parts a peculiarity.
• Adults are radially symmetrical, but the larvae are bilaterally symmetrical.