Walking Corals have been recently introduced to this hobby from Australia. At the beginning of their lives, the coral larvae attach onto a small snail shell, and begin to lay down their structure. A Sipunculid Worm moves into the shell becoming trapped which results in a symbiotic relationship allowing the coral to be mobile and offering protection for the worm. It is best to have sand for the coral to "walk". The coral is photosynthetic, and the worm is a deposit feeder consuming organics throughout the sand.