Possible Clues:

• Lost fish, in a Pixar film
• Fish found in a film
• Title character in a 2003 Pixar film
• Fish found in a 2003 film
• Lost-and-found fish
• Fictional clownfish
• Marlin searched for him
• Title fish in a Pixar film
• Verne voyager
• Marlin's son, in a 2003 film