A still from a video shows a shark lit by a single source light. It's gills are almost invisible.
A video caught at in deep sea shows a hammerhead shark. Its gills look almost invisible as it holds its breath.
  • 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 to keep their bodies warm. 

Hammerhead sharks can hold their breath to survive almost freezing-cold waters during deep dives, a study has found.