Hammerhead sharks are able to deep dive to frigid, near-freezing waters to catch rare prey. But scientists have long been confused about how the cold-blooded animals survive such cold waters. A new study shows the sharks can stop breathing during the dive ...

Fur seals may look like they’re simply resting after exhausting hunting trips at sea, but their bodies are secretly working overtime. Scientists discovered that hours after returning to land, the seals’ heart rates suddenly surge — sometimes doubling — as they recover from the intense physical stress of deep diving.