Holothuroidea, or sea cucumbers, are cylindrical, sometimes vermiform echinozoan echinoderms which generally act as scavengers, detritivores, or specialised suspension feeders, and are often considered to be some of the most derived of the echinoderms; having retained mostly bilateral symmetry, with only some parts of their bodies displaying the diagnostic pentaradial symmetry of most adult echinoderms. Members of this order play a critical role in keeping the seabed clean, and, in turn, many species of sea cucumber may be host to parasites, their spacious body cavities providing shelter to various parasitic and commensal symbionts alike.
Some sea cucumbers are known for their ability to eviscerate themselves, violently shedding their breathing organs from out of their cloacae, to escape from predators. This is often to little detriment to the animal, however; as they can easily regenerate these parts, along with many other structures.

Species

• sea_pig

See also

• marine
• echinoderm
• sea_cucumber