Pixar's characters are often planned years in advance. Nemo first appeared as a stuffed toy on a couch in Boo's room in Monsters, Inc.. This movie introduces the main characters of post-2003 Pixar films. A boy in the dentist's office is reading a "Mr. Incredible" comic book, anticipating The Incredibles. Luigi the car is driving by the dentist's office, anticipating Cars.
According to the DVD, the names of the nine boats seen in the Sydney harbor are: Sea Monkey, Major Plot Point, Bow Movement, iBoat (a reference to iTunes, the company created by Pixar CEO Steve Jobs), Knottie Buoy, For the Birds, Pier Pressure, Skiff-A-Dee-Doo-Dah (a reference to Song of the South's most famous song "Zip-a-Dee-Doo-Dah"), and The Surly Mermaid.
Afraid that kids would try releasing their pet fish by flushing them down a drain, a company that manufactures equipment used by water filtration and sewage treatment plants released a warning the Thursday after the film came out saying that, even though drains do eventually reach the ocean, before it got there the water would go through equipment which breaks down solids, and went on to say that in real life the movie would more appropriately be called "Grinding Nemo".
The waiting room in the dentist's office was modeled after the waiting room in a real dentist's office in Emeryville, California, where Pixar Animation Studios has its headquarters.
Albert Brooks was always Andrew Stanton's first choice to voice the part of Marlin. Although Brooks had done several episodes of The Simpsons, he found voice work for a feature length cartoon to be substantially different in that he had to do it in isolation, and not alongside any other actors. He didn't particularly enjoy the experience.
The look and feel of the underwater world was essential to the film's success. To that end, the production crew were all exposed to visits to aquariums, diving stints in Monterey and Hawaii, study sessions in front of Pixar's own 25-gallon fish tank and even a series of in-house lectures from an ichthyologist.
Andrew Stanton pitched his idea and story to Pixar head John Lasseter in an hour-long session, using elaborate visual aids and character voices. At the end of it, the exhausted Stanton asked Lasseter what he thought, to which Lasseter replied, "You had me at 'fish'."
For the jellyfish sequence, Pixar's Ocean Unit created an entire new system of shading which they called "transblurrency" - see-through but blurred, much like a frosted bathroom window.
As "research", the key figures of the production crew had to get SCUBA certification and go to the Great Barrier Reef on the insistence of John Lasseter.
To see how realistic they could make it appear, the art team were asked to make exact copies of actual underwater and above-water shots. Ultimately the results were simply deemed "too realistic" for a cartoon.
According to the DVD, there are some references to Massachusetts in the film as one of the creators is from Rockport, Massachussetts (a small town on Cape Ann, about one hour north of Boston). In the dentist's office are two "lighthouse lamps" modeled after the twin lighthouses on Thatcher Island (just off the coast of Rockport). Also in the dentist's office is a framed picture on the wall of "Motif Number One", a very frequently photographed (by tourists) building on a dock in downtown Rockport. Finally, while various sea creatures are relating Marlin's quest across the ocean, one step is a group of lobsters that speak with Boston accents and slang ("wicked daahhk"). The DVD commentary is not incorrect about lobsters in Australia. While it is true that Australia has lobsters, the featured lobsters are clawed lobsters. Australian lobsters, indeed most of the world's lobsters, are actually spiny lobsters. However, since the lobsters seen discussing Marlin's quest have New England accents and use words such as "wicked," it is likely that they are from near Massachusetts; emphasizing the point that Marlin's story is known all around the (sea) world.
In the tank gang in the dentist's office, the germophobic purple and yellow fish is the only one never mentioned by name. His name was later revealed to be Gurgle.
Though never mentioned in the film, it is revealed by the directors in the commentary that Crush and his crew of thrill-seeking turtles are headed for Hawaii. Also mentioned in the commentary is that the young turtles' shells are modeled after Hawaiian shirts.
Rendering a frame which lasted about 1/24th of a second in the film could take up to four days because of the complexity of the underwater environment with sunlight coming through the water and hitting fish scales.
One musical theme that Thomas Newman composed for the score did not end up in the final film but still appeared both in one of the trailers and on one of the DVD menus.
Director Andrew Stanton originally planned to reveal the fate of Marlin's wife gradually through flashbacks seen periodically as the story unfolded. After a few early in-house screenings, he found that Marlin came off as too much of a worrywart, and decided to reveal the entire back-story up front, thus making Marlin more appealing by establishing the reason for his over-protectiveness.
Originally, the whale that swallows Marlin and Dory approaches them from the front. This version of the scene appeared in an early trailer. The final version, with the whale coming from behind, was inspired by an early animation test showing a whale emerging from the murk of the ocean behind a small fish.
Pixar developed a very realistic look of the surface water, but had to make it look more fake so people wouldn't think it was real footage of the ocean surface.
EASTER EGG: On the Bonus Features menu on disc 2, highlight the return symbol, then press down, and a green fish will appear. Select this to see a commercial for the Aquascum 2003.
Jacques' character is partly based on actor Fritz Feld, whose trademark was to "pop" his mouth by slapping it with the palm of his hand to indicate his "superior" annoyance.
When Dory is comforting Marlin in the whale, the animators used the exact same sequence earlier in the movie when Dory meets Marlin for the first time.
Nigel's line, "Fish gotta swim, birds gotta eat" is a reference to the line "Fish gotta swim, birds gotta fly," in the song "Can't Help Lovin' That Man" from the Broadway musical 'Show Boat'.
The great white shark's name in the movie was Bruce. "Bruce" was the nickname given to the models used for the shark in the original "Jaws", named after Spielberg's lawyer, Bruce Ramer.
Per the DVD extras, Albert Brooks spent an entire day in the recording studio improvising badly mangled versions of the anemone joke; no two tellings were fumbled in the same way. He had the recording technicians in stitches for the duration.
When Gil is thinking ahead about how he and the fish will escape, as the camera pans toward and out the window, the Pizza Planet truck from Toy Story can be seen on the outside.
The dentist's camera's model number is A-113, a number which appears in all Pixar movies as a reference to the California Arts University room where the animators of Pixar Studios attend.
Among the toys in the waiting room are the jack-in-the-box and Buzz Lightyear and, on a shelf, the plane he used to "fly" in Toy Story and Pixar's trademark ball from Luxo Jr..