Sea cucumbers are one of the most important members of
sand and mud benthic communities. They belong to the
phylum echinodermata (meaning spiny skin) making them
relatives of sea stars and sea urchins. As such, they have
radial symmetry and tube feet used for feeding and
movement. They are found throughout the nearshore coral
reef environment and are also found in the deepest parts of
the ocean. Sea cucumbers play an important role in reef
recycling, gathering organic detritus and bacteria from the
water or sand for food. These particles are digested by the
animals in order to extract nutrients, a process that helps turn
over sediments to maintain an environment that supports
other marine life. Other animals, including fish, crustaceans,
and molluscs, eat sea cucumber eggs, larvae and juveniles
making them an important member of the food web. Many
species eject Cuvierian tubules when threatened. These are
very sticky and can be toxic or irritating to predators.