Sea cucumber

The sea cucumber is related to the starfish and sea urchin and looks like a soft, warty cucumber. It crawls along the bottom eating sand, filters tiny scraps out of it, and passes the clean sand back out. When threatened, it can even shoot out parts of its insides and grow them back later.

For scientists

Sea cucumbers (Holothuroidea) are echinoderms with a five-rayed body plan and a water vascular system; they breathe through branched respiratory trees that open into the hindgut. As deposit feeders they turn over large amounts of sediment and are important recyclers of the seafloor. For defense many species can expel sticky tubes or parts of their internal organs (evisceration) and regenerate them later.

Source: Smithsonian Ocean

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