Family: echinoderm. Found at all depths of the ocean, the Starfish or Sea Star is the common name for five orders and about 1500 species of the class Asteroidea of the phylum Echinodermata. Adult Starfish range in size from 1cm to 65cm. Other classes of echinoderms include the sea urchins, sand dollars, sea cucumbers, sea lilies, and brittle stars. Starfish live on ocean bottoms at both deep and shallow depths. Underneath each arm are hundreds of tiny suction cup feet that the starfish uses to propel itself. At the end of each arm is an orange eyespot. The starfish can not see but uses its eyespot to sense light and dark.