Holothuroidea contains over 1,400 species of soft-bodied animals known as sea
cucumbers. These animals live on the bottoms of oceans and seas around the
world, where they often make up the majority of the deep ocean biomass. The
elongated ("cucumber-shaped") body has a mouth that is surrounded by retractile
tentacles at one end and an anus at the other. These animals move slowly using
tube feet and waves of contraction of their powerful body muscles. They feed on
small organisms captured by the sticky mucus on their tentacles.