Nemo is a young clownfish who lives with his father, Marlin in a sea anemone. Before he hatched from his egg, Nemo's mother, Coral, and the other eggs were killed in an attack by a barracuda. Only Nemo's egg survived, albeit slightly cracked. As a result of the crack, one of Nemo's fins is smaller than the others, thus Marlin worries about him. One day, Nemo heads off to his first day of school. At one point, he boldly leaves the reef to touch a boat on the open ocean. Marlin, who is watching, argues with Nemo, but Nemo is suddenly taken by a diver to a fish tank in a dentist's office in Sydney, Australia.