The spiky animals featured in this short video are sea urchins. Sea urchins are fascinating creatures. They belong to the same family as the starfish, sea cucumbers and the sand dollar. A family known as Echinoderms. Often an under appreciated family. Did you know that if a starfish loses an arm, it would re-grow it? Or that a sea cucumber can completely excrete it’s digestive system and then grow a new one? How cool is that? I wanted to explain how these animals move as they often do it so slowly you would not notice (hence the time-lapse video). Also, remembering they are invertebrates so they have no bones. So, how do they do this? Echinoderms have what is termed tube feet. Tube feet are tubular projection with suckers on the end. On the sea urchin they are found between the spines and on the starfish they are found under the arms. In order to control and move these feet the echinoderm will use their vascular system, which consists of water! That’s right water. By contracting chamber of water within the body they control which feet move and which ones don’t. The amazing features of this family do go on and on but as it’s all about them moving I will control myself and stop there.