According to a press release issued by the museum, pancake batfishes are members of the anglerfish family Ogcocephalidae, a group of about 70 species of flat bottom-dwellers that often live in deep, perpetually dark waters. Pancake batfishes have enormous heads and mouths that can thrust forward. This, combined with their ability to cryptically blend in with their surroundings, gives them an advantage for capturing prey.
They use their stout, arm-like fins to walk awkwardly along the substrate; their movements have been described as "grotesque," resembling a walking bat. As most anglerfishes, batfishes have a dorsal fin that is modified into a spine or lure, although their lure excretes a fluid to reel in prey instead of bio-illuminating.
Sparks says the new "discoveries underscore the potential loss of undocumented biodiversity that a disaster of this scale may portend."
(Other species of fish walk too. The below video, for example, shows Australia's spotted handfish.)