Dr. Peter Klimley is a man who has held his breath and dived down 100 feet to hand-tag hammerhead sharks with a dart gun. He has even dressed up as a killer whale, complete with towering black ...

Hammerhead sharks don’t lay eggs, though. They gestate their pups in utero. A pregnant shark carries up to 16 embryos, each nourished by an umbilical cord, just like human embryos are.

I was once at the surface playing low-frequency sounds over a speaker to attract sharks. A hammerhead shot up from beneath me, rushing at me at perhaps 30 feet a second before he suddenly turned ...