Sea Cucumber
Video courtesy of the NOAA Office of Ocean Exploration and Research, 2015 Hohonu Moana. Download (mp4, 29.0 MB)

A sea cucumber, or holothurian, seen swimming just above the seafloor at a depth of ~4,085 meters on September 26, 2015. Sea cucumbers feed on the seafloor, but they can swim to change their locations, perhaps to find a better meal.