Offering further proof that the folks at Pixar are ceaselessly, unflaggingly more clever and imaginative than anyone else working in big-budget feature animation, the underwater CGI-animated "Finding Nemo" opens today -- and it's smarter, funnier and more entertaining than any other all-ages film so far this year.

While Disney's in-house animators have been assembly-lining prosaic sequels ("The Jungle Book 2," "Return to Never Land") and re-imagined misfires ("Treasure Planet") -- and very occasionally coloring a little bit outside the lines ("Lilo and Stitch") -- the computer-'toon platoon at Pixar's Emeryville, California studios is supplying the Mouse House with delightfully creative products like "Monster's Inc." and this new adventure, in which an apprehensive, over-protective clown-fish father traverses the sea in search of his missing son.

The youngster was scooped up near his reef home by some monstrous, two-legged land creature in scuba gear and deposited into a Australian dentist's fish tank, populated by a colorful crew of fellow captives who help little Nemo (voice of Alexander Gould) hatch an escape plan. In the meantime, Marlin -- his fretful father with the perfectly anxiety-ridden intonations of Albert Brooks -- ventures deeper into the deep blue than he has ever dared before, determined to find the boy.

Helped along the way, if "helped" is the word for it, by a dingbat blue tang with short-term memory problems (and the oh-so-apropos voice of Ellen DeGeneres), Marlin finds his courage in dangerous adventures (mines and shipwrecks) and discovers friends in the forms of a surfer-dude sea turtle (voiced by Andrew Stanton, the movie's director), an astute pelican (Geoffrey Rush) who becomes his transportation into the dentist's office, and a trio of 12-stepping sharks who are trying to go vegetarian (including future "Hulk" Eric Bana and Barry Humphries, aka "Dame Edna").

Resourceful in its storytelling (the East Australian Current which Marlin must travel is akin to an underwater freeway crossed with a roller coaster) and reliably, steadily hilarious ("Hey, you're a clown fish," observe all the dopier sea critters who meet mopey Marlin. "Tell us a joke!"), "Finding Nemo" is also astounding to look at. Like a fantastical scuba dive, the picture's always-in-motion undersea universe would be downright photo-realistic if Stanton and his animators hadn't dialed up the cartoonishness just enough to give all the fish googly ping-pong-ball eyes.

From the background plankton to the plastic plants in the fish tank to the way the skin on Bruce the shark (named after the mechanical star of "Jaws") jiggles when he laughs, there isn't a single visual detail overlooked in this three-dimensional wonderland. Yet with the film's refreshing originality, rich comedy, occasional heartfelt poignancy and extremely vivid characters, it's easy to forget all about the how and the wow of the cutting-edge animation technology.

In fact you may forget you're watching animation all together. Such is the complete immersion in "Nemo's" world, created by those magnificent Pixar wizards.