The deepest-sea fish known to science today (3 photos + 1 video)
Fishes of the snailfish family (Pseudoliparis), sometimes called sea slugs, live at record depths of over 7-8 kilometers. They feed on small crustaceans and carrion. 
This is what the deepest-sea fish known to science look like. Pseudoliparis sea slugs inhabit the Mariana Trench and other deep trenches, surviving at depths of over 8 kilometers, where they feed on carrion and small invertebrates.
The species was discovered relatively recently (in 2014), and the deepest specimen was filmed in Japan at a depth of 8,336 meters, earning it a Guinness World Record.
