The word Echinodermata is formed from the Latin words Echinus meaning prickly, derma meaning skin and ata meaning bearing. Animals whose body is symmetrical, five-segmented, ciliated, headless, circulatory system and echinodermata are called Echinodermata. They are called conifers. Animals like sea star, sea cucumber, sea lilies, sea urchin, sand dollar etc. belong to this phase. The number of species is about 7,550. Jacob Klein (1734) named Echinodermata.