Do echinoderms regenerate?

Yes, echinoderms have the remarkable ability to regenerate an appendage when it has been broken off.  In fact, when it comes to starfish, the entire organism can be regenerated as long as there is still one arm and the central disc.  Brittle stars easily lose arms when they are being preyed upon and can grow lost arms back.  The sea cucumber also has regenerative powers and can eject its internal organs to confuse and/or stop predators.  These organs can be regrown.