Far beneath the ocean’s surface, a ghost emerges from the dark, slowly fluttering above the seafloor.

The ghost shark (Hydrolagus spp.) is an ancient relative of sharks and rays. Also known as ratfishes, they have a skeleton made of flexible cartilage, not bone.

Ghost sharks root around the seafloor searching for a meal. They maneuver back and forth with broad fins, sometimes hovering in place. An oily liver helps boost their buoyancy and conserve energy.

Receptors in their heads detect the electrical signals of invertebrates buried in the mud, while a keen sense of smell helps them sniff out rotting carrion. Tooth plates can nip pieces of dead fish or crush hard-bodied prey. A sharp, venomous spine on their dorsal fins offers protection from large sharks and other predators that prowl these same waters.

MBARI is shedding new light on the mysterious lives of the ghost sharks we have observed on the deep seafloor. Video footage from MBARI’s robotic submersibles helped our collaborators describe a new species, the Eastern Pacific black ghost shark (Hydrolagus melanophasma). Our deep-sea video also revealed that the pointy-nosed blue chimaera (Hydrolagus trolli), originally discovered in the South Pacific, may live across the North Pacific too.

Ghost sharks live deep underwater, but our actions on land loom large for their future. Some species are caught as accidental bycatch in commercial fisheries, while others are at risk from seafloor mining. 

The deep sea is closer than you think. Our everyday choices can make a difference for ghost sharks and other denizens of the deep. Together, we can ensure these ancient animals continue to thrive for countless generations to come.