Image courtesy of NOAA Bioluminescence and Vision on the Deep Seafloor 2015. Download larger version (jpg, 93 KB).
A cutthroat eel, Synaphobranchid, caught on video using the Medusa lander. Medusa uses red light illumination that is invisible to most deep-sea animals and an intensified camera that amplifies both this dim illumination as well as any bioluminescence. Unlike a remotely operated vehicle, Medusa is silent and has near-infrared light, which allows it to capture organisms in the deep-sea on film with very little impact, providing phenomenal footage of deep-sea animals in their natural environments, acting the way that they normally do.
From: Medusa Deep in the Gulf of Mexico.