Nemo Nevio

Nemo is a young clownfish who lives with his father Marlin in the
Great Barrier Reef. Nemo, despite being hampered by a lame right fin, is
 eager to explore life around the ocean. Marlin, however, is
overprotective of him, having lost his wife Coral and all their other
eggs in a barracuda attack, leaving Nemo as his only child. On Nemo's
first day of school, Marlin unintentionally embarrasses him, and while
Marlin is distracted with the teacher, Mr. Ray, Nemo defiantly sneaks
away from the reef toward a speedboat, where he is captured by a pair of
 scuba divers. Marlin tries to chase the boat and meets Dory, a blue
tang who suffers from acute short term memory loss, who accompanies him.
 During an encounter with three sharks who have sworn to abstain from
eating other fish, Marlin notices a diver's mask that fell from the boat
 that took Nemo. Marlin and Dory fight over the mask, giving Dory a nose
 bleed, which sends one of the sharks into a feeding frenzy, and Marlin
and Dory narrowly escape, but are knocked unconscious when the sharks
accidentally set off an old mine.

Meanwhile, Nemo is placed in an aquarium in a dentist's office in
 Sydney, Australia, where he meets the Tank Gang, including yellow tang
Bubbles, sea star Peach, cleaner shrimp Jacques, blowfish Bloat, royal
gramma Gurgle, and damselfish Deb, led by Gill, a Moorish idol. That
night, Nemo learns he is to be given to the dentist's young niece,
Darla, whose rough treatment has killed most of her previous fish. Gill
devises a risky escape plan: Nemo, who can fit inside the aquarium's
filter tube, will jam the filter with a pebble, forcing the dentist to
put the fish into plastic bags while the tank is cleaned, giving them
the opportunity to roll out the window and into the harbour. Nemo
attempts the maneuver, but fails and is almost killed, leaving Gill
guilt-ridden.

Marlin and Dory wake up unharmed, but the mask falls into a deep
sea trench. Swimming after it, Marlin is chased by an anglerfish, while
Dory reads the address and recites it repeatedly to commit it to memory.
 Dory and Marlin receive directions from a school of moonfish, but
Marlin disregards their instructions to take what he believes is a safer
 route, leading them into a forest of jellyfish where they end up
unconscious from all the jellyfish stings. Marlin and Dory wake up to
find themselves on the East Australian Current with a group of friendly
sea turtles including Crush and his son Squirt. Marlin tells them about
his quest, impressing them, and news spreads across the ocean, all the
way to the dentist's office, where a pelican named Nigel tells the Tank
Gang. Inspired by his father's bravery, Nemo makes another attempt to
jam the filter, and succeeds, and soon the aquarium's contents are
covered in green algae.

Marlin and Dory exit the East Australian Current and are engulfed
 by a blue whale. Dory communicates with the whale, who carries them to
Sydney Harbour and expels them through his blowhole. There, they meet
Nigel, who help the pair escape from a group of seagulls and takes them
to the dentist's office. Meanwhile, the dentist has installed a new
high-tech filter, the AquaScum 2003, foiling the Tank Gang's escape.
Darla arrives, and the dentist prepares to give Nemo to her. Nemo plays
dead to save himself as Nigel causes a disturbance, terrifying Darla and
 throwing the office into chaos. After the dentist throws Nigel out,
Gill helps Nemo escape through a drain that leads to the ocean.

Thinking that Nemo is dead, Marlin abandons Dory (after thanking
her and saying he's going home on his own) and begins his journey home.
Marlin's departure causes Dory to lose her memory. She meets Nemo as he
reaches the ocean, but does not remember him. However, Dory's memory
returns when she reads the word "Sydney" on a drainpipe. She reunites
Nemo with Marlin, but is caught by a fishing boat with a school of
grouper. Nemo enters the net and orders the fish to swim down in order
to break the boat's net so they can escape. After returning home to the
reef, Marlin and Dory watch Mr. Ray take Nemo and his friends on a field
 trip. At the dentist’s, the Aquascum 2003 has broken, and the gang,
having been put in bag, roll out of the window and into the sea. Still
stuck in bags, they ponder what happens next.