Ghost sharks, aka chimaeras, are elusive relatives of sharks and rays that live in the black depths of the ocean, as far down as 2,600 meters. The Ghost Shark was captured on video by a remotely operated vehicle deployed on a geology expedition by the Monterey Bay Aquarium Research Institute in waters off Hawaii and California. The scientists who analyzed the video think that it's a pointy-nosed blue chimaera (Hydrolagus trolli) that usually calls the waters off Australia and New Zealand home. This is the first time researchers have known this species to swim in the Northern Hemisphere. From National Geographic:
Unlike those more well-known sharks, chimaeras don't have rows of ragged teeth, but instead munch up their prey—mollusks, worms, and other bottom-dwellers—with mineralized tooth plates.
A pattern of open channels on their heads and faces, called lateral line canals, contain sensory cells that sense movement in the water and help the ghost sharks locate lunch.
And perhaps most fascinating, male chimaeras sport retractable sex organs on their foreheads.