Nemo actually made his first big-screen appearance in the movie Monster's Inc. He was an adorable little stuffed fish toy that Boo hands to Sully. (Source)

Initially, Pixar animators made the surface of the ocean water look too good. The bigwigs at Pixar were worried that moviegoers would just think they were using filmed footage of the sea. (Source)

Pixar doesn't play around. The production team for Finding Nemo got to visit all kinds of aquariums, go diving in the ocean, and even talk to a real ichthyologist (i.e. a person who studies fish for a living). (Source)

It's Pixar Easter egg time! The scuba diver's underwater camera has a model number of A-113 on it. That number appears in every single Pixar movie because it's a classroom number at California Arts University where a bunch of Pixar animators learned their stuff. (Source)

We guess it's our duty to tell you this, but the fish science behind this cartoon is not totally accurate. Clownfish are natural hermaphrodites who can change from male to female depending on who's hanging around the anemone. In real life, when the male Nemo was born, Marlin would have switched sexes and mated with his son to produce more clownfish eggs. Not sure if kids would psyched to see a cartoon about fish incest, but, hey, that's nature for you. (Source)