Census of Marine Life researchers discovered this unusual transparent sea cucumber (Enypniastes sp.) in the Gulf of Mexico at 2,750 meters depth. It creeps forward on its tentacles pretty slowly, at around 2 centimeters per minute, while sweeping detritus-rich sediment into its mouth. It's so transparent that you can even see its digestive tract winding through its body! See more cool zooplankton discovered by the Census of Marine Life, or learn more about the deep sea.