There's a new boss in charge at the Discovery Network, and he's anxious to get rid of mega-sharks, mermaids and man-eating snakes.

Rich Ross, a longtime Disney executive who began this week as president of Discovery Communications' flagship channel, said he wants to broaden its appeal to reach more women and families. He has also been quick to make clear what he doesn't want Discovery to be.

The network has been doing well financially but has been criticized, particularly by the scientific community, for some specials that have stretched the boundaries of truth. Most recently, animal rights activists were angered by the "Eaten Alive" premise of an explorer who would be swallowed by a giant anaconda. The reality turned out to be far less dramatic.

Discovery's annual "Shark Week" the past two years have featured fanciful "documentaries" about megalodons. The network also aired a show, produced by sister channel Animal Planet, about mermaids and another about a supposed Russian yeti.

"Brands are all about trust," said Ross, who is replacing former network head Eileen O'Neill and her interim successor Marjorie Kaplan, in an interview Thursday. "You can expand the universe of what people think you are, but there's only so much elasticity. On Discovery, that's why I talk about authenticity. Authenticity is job No. 1, 2 and 3."

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Fictional documentaries, no matter their entertainment value, no longer have their place, he said.

"It's not whether I'm a fan of it," he said. "I don't think it's actually right for Discovery Channel and it's something that I think has, in some ways, run its course."

"Eaten Alive" had the right intention — to tell the story of a rare and frightening large snake — but misleading packaging, he said. The fervor of the story got out of control, he said.

"I don't believe you'll be seeing a person eaten by a snake during my time," he said.

One of his first hires at Discovery is designed to send a clear message. John Hoffman, a multiple Emmy Award-winner who spent many years in HBO's well-regarded documentary unit, was named Discovery's executive vice president of documentaries and specials. As an independent producer, Hoffman most recently did the project "Sleepless in America" for the National Geographic Channel.

One Discovery star whose time may be up is high-wire walker Nik Wallenda. His live walk over the Grand Canyon in 2013 was a sensation, averaging nearly 10.7 million viewers. Last year's sequel, between skyscrapers in Chicago, had barely more than half the audience.

Ross said he's not ruling out another Wallenda walk, but that it has to be something special, and the Grand Canyon is a hard act to follow.

Shark Week may not have megalodons, but President Obama's effort to reset the country's relationship with Cuba may benefit Discovery. Ross said the network is at work on a show about a particularly shark-filled area near Cuba that has not been explored in-depth by television before because of the lack of relations between the U.S. and Cuba.

By roughly a 60 percent to 40 percent margin, Discovery's audience is dominated by men. Ross said he wants to get more families interested. He's hoping to get two scripted series ready this year, with an historical miniseries the most likely candidate. History is an area that's a rich part of Discovery's heritage and he's anxious to return to it.

Ross is considering projects about episodes in history that echo what is happening in the world today.

"Wouldn't it be amazing if we could tell stories that are actually indicative of behaviors and situations and see if we can alter them in a positive way?" he said. "That's my kind of interactive — make people care."