1. List the five classes of echinoderms, one example of each class, and one distinguishing characteristic of each class.
Crinoidea (meaning sea lily): Members include sea lilies and feather stars. They are sessile (I.e. they do not move.).
Asteroidea (meaning sea star): Members include starfish. They appear as a star with five arms and live in coastal waters with rocky shores.
Ophiuroidea (meaning snake-like): Members include brittle stars and basket stars. They live primarily on the sea bottom under rocks or in crevasses and have long, quick-moving, flexible arms.
Echinodea (meaning hedgehog-like): Members include sea urchins and sand dollars. Their internal organs are enclosed in a “test” and food is ground up in a jaw-like structure called “Aristotle’s lantern.”
Holothuroidea (meaning armless): Members include sea cucumbers. They lack an exoskeleton making this class the only soft echinoderms.
2. List five characteristics common to most echinoderms.
3. What is the meaning of the phylum name Echinodermata?
Echinodermata is from the Greek roots “echinos” (hedgehog) and “derma” (skin).