This web page has been created by Katie Blanscett, Paige Evans, and Tessa Heath!

Introduction

Even though they've evolved into their few different forms, echinoderms have never left their home on the ocean floor. The names of these common organisms reflect the fact that they have stayed on the bottom of the ocean: sand dollar, sea urchins, sea star (or starfish), sea cucumber, and sea lily. The name Echinoderm is derived from the Greek word meaning spiny skin.

When embryos, they are free swimming echinoderms and have bilateral symmetry. Adults, however, have radial symmetry, and are without a head and brain. Echinoderms are somewhat sluggish and move very slowly as they feed on algae or other small particles that are sifted from the sand and water. Echinoderms move on several tiny tube feet, which are very unique. They are delicate and extend from the underside of the organism and contain a suction cup. Echinoderms also posses an endoskeleton and contain a water vascular system.

Click on the pictures for more information.

sea starsea urchins

sea cucumber

sea cucumber picture found atwww.ucmp.berkeley.edu/

sea urchin picture courtesy of Eric Rude

For more information on Echinodermata check out http://oceanlink.island.net/oinfo/biodiversity/seastars.html and http://web.mit.edu/corrina/tpool/stars.html