Scientist-adventurer Brady Barr has traveled all over the world to study hundreds of animal species, but a recent trip took him somewhere few people have ever been -- to see one of the world's most mysterious, and some believe one of the oldest living creatures.
Call it the "Jurassic shark." The six-gill shark is one of the least understood sharks in the world, Barr said. That's because the six-gill lives thousands of feet below the ocean's surface in frigid, pitch-black waters and almost never comes into contact with humans.
Barr, 46, went to Central America and traveled 1,700 feet underwater in a man-made submarine to catch a glimpse of the ancient creature for his National Geographic Channel series, "Dangerous Encounters With Brady Barr."
"More people go to the top of Mount Everest than the ocean floor," he said.
Barr sat on the ocean floor for six hours and eventually he spotted several six-gills, the third largest shark species, which have green eyes like night-vision goggles that allow the sharks to see in the dark waters.
"I grew up in the time of 'Jaws,' so sharks terrified me," said Barr, who grew up far from the ocean in Indiana. And his recent shark encounter still got his "heart beating fast."
A herpetologist, Barr is a crocodile expert, calling himself the "ambassador for that animal," and the only one to have captured all 23 species of crocodile.
"I don't capture animals just for TV, there has to be a scientific reason," Barr said.
Barr's mission is two-fold -- to collect as much information as possible about the animals he studies and to educate people about the plight of the planet and the danger of extinction so many animal species face.
For example, one-third of all crocodile species are endangered, he said.
"People don't want to line up and protect the cold and scaly animals," Barr said.
But crocodiles are a "keystone animal," he said. "If you remove a keystone, a building can collapse."
Baby crocs provide food for other animals. As predators, crocodiles regulate the animal population around them, and they modify the ecosystem by building nests and digging holes.
"They're very complex," Barr said. "They're better parents than a lot of humans I know. They're very vocal. … They can find their way home."
In his other "Dangerous Encounters" episodes, which will be shown throughout January, Barr looks at giant salamanders, which can measure up to 5 feet long and weigh 100 pounds.
"They are critically endangered, barely hanging on to existence," he said.
Barr also returns to the cave in Indonesia where last year he was bitten by a 12-foot reticulated python just below his rear end. What could possibly compel him to return after wading through 10 inches of bat guano in the spooky, cockroach-infested cave and then having a python sink its fangs into you?
"I had to go back to finish what we started," he said.
And, of course, it makes fabulous TV.
This trip was not without incident either. Barr was put in the hospital again after venturing into the cave a second time, but not because of a snake bite.
"I had fungus in my lungs and horrible parasitic worms in my body," he said.
Does any animal get to Barr -- could he do without kittens, or perhaps he hates bunnies?
"You know what gives me the creeps? Bats. Bats kind of freak me out."
To find out more about the National Geographic Channel's "Dangerous Encounters With Brady Barr" click here.