Trivia: The dentist's name, P. Sherman, is a homage to the many Filipino crew members, whose native accent made the English word 'fisherman' sound like P. Sherman.
Trivia: In the waiting room of the dentist's office you can see a Buzz Lightyear action figure lying on the floor. (00:25:35)
Trivia: The kid in the waiting room is reading a comic with Mr. Incredible on the cover, from the Disney/Pixar movie The Incredibles. (01:19:25)
Trivia: While the credits are rolling you see most of the characters swim onscreen. Stay long enough and you'll see Mike from Monsters Inc. swim across with a scuba mask and fins. (01:39:10)
Trivia: Great White shark in the rehab group is named Bruce, the same name Steven Spielberg called the mechanical shark in Jaws. Pixar is known for crediting great filmmakers from the past, in their movies.
Trivia: If you look closely when Nigel hits the dentist's window, you can see Boo's mobile from Monsters, Inc. attached to the dentist's ceiling. (00:28:30)
Trivia: In the first scene the tank has become dirty, you can see the dentist outside talking to a kid in the dentist chair, he says to the kid, 'Little David Reynolds...', which is the name of one of those who have done the screenplay of the film. The name appears in the ending credits before the Cast. (01:07:20 - 01:33:30)
Trivia: This is just an interesting anecdote: In an Australian newspaper, some poor irate viewer of 'Finding Nemo' wrote a long and indignant letter abusing the creators of this movie for using AMERICAN pelicans rather than AUSTRALIAN pelicans (noticeable only for the fact that Aussie pelicans don't have brown feathers and Nigel does). This anonymous person was 'disappointed that the creators couldn't even make the effort to use native Australian fauna'. The editor of the paper replied to the letter thusly: 'Thank you for your heartfelt contribution. We also noticed a glaring mistake in 'Finding Nemo': Fish can't talk.' However, this is in no way meant to offend the person who has already pointed out this mistake on this site.
Trivia: The voice of Crush, the sea turtle dude, is Andrew Stanton, the writer and director. He was actually never intending to use his voice in the film. Similar to Brad Bird in The Incredibles, he did the voice as a guideline before searching for an actor to play Crush, only to realise that his voice ended up fitting the role better than the person he hired.
Trivia: The Mermaid from the short film "Knick Knack" is seen inside the fish tank.
Trivia: When we see the close up of the whale's head while he is blowing bubbles you can see they spell the word SEX or SFX depending how you look at it. Very similar to what they did in The Lion King.
Trivia: A tip of the hat (or two) is given to the first Disney underwater flick, 20,000 Leagues Under the Sea. The title character Nemo was the name of the captain from 'Leagues'. The song 'Whale of a Tale' was sung in both movies.
Trivia: In the dentist office, when the dentist accidentally hurts his patient (who screams while his mouth is still open) the dentist says "Good thing I pulled the right one, eh Prime Minister?" The man in the chair looks like Paul Keating, Prime Minister from '91-'96, prior to John Howard, who was in office from '96 to '07, before the start of the film's production and long after its release. However the idea for Finding Nemo was first hatched in '92 when Keating was in office, so the appearance of the man in the chair is a likely nod to that. (00:58:30)
Trivia: John Ratzenberger, who does the voices of the school of fish - who do the impressions for Dory, has done a voice in every Disney-Pixar movie. He has done Hamm in Toy Story and Toy Story 2, P.T. Flea in A Bug's Life, the Yeti in Monsters, Inc., and Underminer in The Incredibles.
Chosen answer: Nigel is a pelican - he appears to be modelled on a Brown pelican (although that particular species is not actually native to Australia).
Tailkinker ★