Explain how all echinoderms show five-sided radial symmetry when they look so different.How does a tube foot work? Explain using words and drawings. Most of the echinoderms have hard parts and spines for defense, but the sea cucumbers do not. How do sea cucumbers protect themselves from predators?

All Echinoderms possess five-part radial symmetry around a central disc. They all possess a very unique water vascular system. These unique characteristics distinguish echinoderms from other animals in the animal kingdom.1. Echinoderms have five-way radial symmetry, a pattern most familiar in the shape of the starfish. Various Echinoderms have different shapes, they still possess radial symmetry like sea cucumber which is also an Echindoerm possess radial symmetry which is shown in this character as shown in the five strips of muscle inside the body wall, running from the front to the back. Similarly, sea urchin is globular and radially symmetrical, which is shown in its early embryological stages which are globular and radially symmetrical. 2. The tube feet in a starfish are arranged in grooves along the arms. They operate through hydraulic pressure. They are used to pass food to the oral mouth at the center and can attach to surfaces. 3. When threatened by some predator, some sea cucumbers discharge sticky threads to frighten their enemies. Others can mutilate their own bodies as a defense mechanism. They violently contract their muscles and throw some of their internal organs out of their anus. The missing body parts are quickly regenerated.