Ctenophore
Video courtesy of the NOAA Office of Ocean Exploration and Research, 2015 Hohonu Moana. Download (mp4, 16.8 MB)

This red ctenophore with long tentacles was documented not far off the bottom at Southernmost Cone on September 20, 2015.
Because of the way that light is transmitted through the water column, red light does not reach ocean depths. This means that the red of deep-sea animals actually appears black and thus is less visible to predators and prey. The red stomach of this ctenophore gives it a sort of invisibility cloak – if the ctenophore eats something that is not transparent, having a red stomach helps hide its last meal.