Sea cucumbers are a common component of deep-sea fauna. Unlike shallow-water animals, these distant relatives of starfish are highly modified in the deep sea, very colorful, and have exotic forms. Here is one that is adapted to live a pelagic existence using highly modified tube-feet as fins to swim near the bottom, but it still feeds on sediment on the sea-floor surface. Video courtesy of Expedition to the Deep Slope, NOAA-OE.