Who can survive the ocean’s darkest depths, bearing the weight of the sea on their “shoulders”? These photos and video clips shed light on a few of the deep-sea dwellers that marine scientists have seen en route to hydrothermal vent sites over 2,500 meters (1.5 mi) down. Vent sites have been called the “oases” of the deep sea for their abundance and diversity of life.

While few fish live at hydrothermal vent sites — with the exception of pale eel-like zoarcids — fish have been found at great depths elsewhere in the ocean. How low can they go? The greatest depth at which a fish has been recorded is 8,370 meters (5.2 mi).