Why hammerhead sharks dive on breath-hold

Hammerhead sharks can stay warm even when diving to extreme depths – by performing the equivalent of marine mammals’ breath-hold dives. In previously unobserved behaviour, scientists now believe the sharks “hold their breath” simply by closing their gill-slits at critical moments. Sharks are among the many big fish known to dive regularly to “mesopelagic” depths, … Continue reading Why hammerhead sharks dive on breath-hold