Active shark species like the mako and great white shark tend to swim closer to the surface because of their need for speed.

Other shark characteristics include using their gills to extract oxygen from the water, rather than breathing air. Unusual ...

Researchers say great white shark population off East Coast is booming 02:52. As summer begins and people spend more time in the ocean, researchers are on the verge of learning more about the ...

(soundbite of whale shark breathing) SOMMER: Whale sharks are the largest fish species on the planet, as long as a school bus. This whale shark was a juvenile, though still about 16 feet long, and ...