Walt Disney Co.'s "Finding Nemo Submarine Voyage" attraction opens today as the world's largest theme park operator seeks to build on last year's attendance gains from its 50th anniversary promotion.

The ride is the first at Disneyland in Anaheim, California, based on Pixar's "Finding Nemo" movie. It replaces "Submarine Voyage," shuttered nine years ago.

Chief Executive Officer Robert Iger is adding attractions to draw larger crowds to Disney's theme parks after last year's anniversary campaign. Using Pixar characters in the parks was part of his strategy for paying $8.06 billion for the animation studio last year. "Nemo" is the top-grossing Pixar movie with $864.6 million in worldwide box-office sales.

"It's only natural Disney would put in a ride for the Pixar movie that has grossed the most," said David Miller, a Los Angeles-based analyst for SMH Capital. "We have always been somewhat surprised even before the Pixar acquisition there aren't more rides associated with the films."

Disney, based in Burbank, California, also is opening a "Pirate's Lair" on Disneyland's Tom Sawyer Island. Last July, the company retooled Disneyland's "Pirates of the Caribbean" attraction to include animatronic characters from the films starring Johnny Depp.

The "Nemo" ride may help increase Disneyland's attendance after the success of the 50th anniversary, Miller said. "There should be a bump."

Last year's campaign helped boost attendance by 6 percent to 112.5 million visitors worldwide, according to data from the Themed Entertainment Association.

The increase was driven by an 8.6 percent gain at Animal Kingdom near Orlando, Florida, which added a roller coaster, and 5.2 million visitors at Hong Kong Disneyland in its first year.

Disneyland had a 1.2 percent increase, smaller than at Animal Kingdom or another newer park, Disney's California Adventure in Anaehim, the trade group said. Disney used the anniversary of Disneyland to promote all of its parks worldwide.

"Don't forget, most fund managers hold Disney shares because of the parks and ESPN," Miller said. "They're not nearly as interested in consumer products or the studio."

The theme-park division is Disney's second-largest by revenue after its media networks, which include cable networks, ABC and broadcast radio. The unit has the highest average two- year growth among any division.

Theme-park profit increased 19 percent to $254 million in the second quarter ended March 31 on an 8.7 percent gain in sales to $2.45 billion, fueled by higher guest spending, ticket prices and attendance.

Disney has six of the 10 biggest U.S. parks. General Electric Co.'s Universal Studios had three, the Themed Entertainment Association, a trade group, said in April.

The largest U.S. resort, Disney's Magic Kingdom near Orlando, Florida, had a 3 percent increase in attendance. Universal Studios in Florida showed growth of 1.2 percent.

Disney doesn't publicly release its attendance figures.

In the ride, a submarine navigates ruins and a coral reef before entering the "Nemo" portion, where animated characters swim by the portholes. The attraction, which took three years to build, uses much of the infrastructure of "Submarine Voyage."

"The biggest challenge was the submarine itself," said Kathy Mangum, the ride's executive producer and vice president at Walt Disney Imagineering. "The audience is moving through scenes at different rates from each other."

The company didn't disclose how much the ride cost.