Sharks do not have eyelids and are thus never going to appear asleep as we would expect.
The video was sent to a local 'shark hunter' who posted it online.
Sharks have been researched for treatments for cystic fibrosis and viral infections.
From virgin birth to amazing ways they deal with swallowing rubbish, sharks are full of surprises.
Sharks have an abundance of coolness currency.
Great white sharks are not the only species dangerous to humans.
It's rare, but it happens.
They were enjoying a day by the beach near Santa Barbara.
The swimmer was leaving the waters after warnings from lifeguards when the shark attacked.
The video was shot over the shores of Panama City.
And it's not the first time this has happened.
A study of why whale populations declined can inform conservation strategies for sharks.
Big shark circled boat and at one point attempted to take a bite at the craft's motor.
Tiffany Johnson is now being fitted for a prosthetic arm after the shocking ordeal.
Aftermath of the incident in Bunbury, Western Australia, was caught on camera.
Rich Thomson, 30, was left with cuts and bruises after being bitten off Bantham beach.
The shark "came out of nowhere".
A nearby beach was closed in April after a shark attacked a woman in the water.
The expedition, known as Under The Pole III, will take scientists on a journey across the world's oceans.
The footage sees the water turn red as the shark is killed.
Thriving shark population had led to warning signs on SoCal beaches.
Multiple sharks have been added to the list to help protect the creatures.