Deep-Sea Sharks Have Better Than Average Buoyancy

A bluntnose six-gill shark in the Gulf of Mexico

UNLIKE BONY FISHES, SHARKS maintain buoyancy with oil-filled livers rather than bony fishes’ air bladders. Recently, it was revealed that doesn’t work well for them in freshwater, where they tend to have poor buoyancy (see “In Freshwater, Sharks Can’t Control Buoyancy). 

DEEP-WATER SHARKS CAN   Now a study has found that deepwater sharks, such as the bluntnose six gill shark, have better than average buoyancy at the depths they frequent. Science writer Chris Cesare describes the study in an AAAS ScienceShot article, “Deep-sea sharks show surprising buoyancy.” To read it, click Here.