"Shark Tale" has its funny moments and some outstanding design elements. But its story is fundamentally misconceived and, in the telling, diffuses like sponge squeezings in the middle of the ocean.

Comparisons, normally unfair, are impossible not to make in this case of computer animated underwater comedies. ... And where imagination, characterization, narrative drive, emotional impact and, crucially, laughs are concerned, this one's a dinghy tossing in the wake of "Finding Nemo's" luxury liner.

The new film's troubles begin with its title. It was originally called "Sharkslayer," which would have made it sound more like an adventure than the talking fish comedy that it is, but otherwise would have been more accurate. The main character is a Will Smith-voiced cleaner wrasse named Oscar, a little fish on a big New York City-kind of reef who dreams of material grandeur. When he's mistakenly credited with killing a predatory shark, Oscar rides the lie to stardom and success.

So the film is more his tale than the sharks'. Which may not be so bad except for the fact that schemer-dreamer Oscar is a very hard hero to root for. Yes, he's part of a comic tradition of con men who manage to rise to the occasion and become better people (or fish). But even with Smith pouring on the fast-talking urban charm, Oscar is too much of a jerk too often.

As for those sharks, well, the main issue on their reef was a quick and clever gag in Nemo, given too much thematic weight here. See, deeze guys are all based on familiar Mafia movie icons. Robert De Niro voices the godfather, Don Lino, and his son Lenny (Jack Black), who's supposed to take over the carnivorous strong-arm business, is, to every traditional shark's horror, a vegetarian!This eventually leads to a weird, secret alliance between Oscar and Lenny, as well as some very strange "coming out" scenes. But it takes too long for Oscar and Lenny to hook up, and that takes the current out of the movie's plot drive.While we're waiting for the story to kick into gear, screen space is filled by stuff that has worked for distributor DreamWorks' successful CGI franchise "Shrek." The reef version of Times Square sports punny ads for outfits like Fish King restaurants and Gup jeans. When not quoting Brando or Pacino, the sharks live it up inside another blatant movie reference, the wreck of the Titanic. Oscar makes his living at a whale wash, which leads to an elaborate, if nonsensical, production number of the '70s song "Car Wash."These and dozens of other pop-culture allusions float somewhere below the "Shrek" level of cleverness. And Italian-Americans are not likely to find the shark family business endearing, no matter how many movies it's supposedly sending up. By the way, if the sharks are supposed to be great whites (had to get that "Jaws" reference in), why are they all black on top and white on the bottom instead of light gray?As for the more colorful sea creatures, they are beautifully rendered. This is the one category in which "Shark Tale" outstrips "Nemo," and it does so by a wide margin. New technology makes the fishes' scales shimmer and change hues gorgeously. And the character animators have done a remarkable job of transferring the more recognizable facial features of the main voice actors (which include Renee Zellweger and Angelina Jolie as good and bad ladyfish, respectively) onto their finny counterparts.This is nowhere better realized than on Martin Scorsese's puffer fish Sykes, an excitable operator whose eyebrows say as much as Leo DiCaprio did in all of "Gangs of New York." Scorsese is one of the three great voice finds in "Shark Tale"; if this cinematic genius thing fails to work out, he has a future in cartoons.The other two real pleasures are Ziggy Marley and Doug E. Doug's joker rasta jellyfish Ernie and Bernie. The notoriously hard-to-animate creatures are also the film's most visually impressive creations, all wriggling dreadlock tentacles and translucent membranes. Should "Shark Tale" somehow prove popular enough to justify a sequel, it ought to be "Invertebrate Story" starring these two.