Okay, if you want to go direct ly to the part, fastfoward to it, otherwise, just watch the movie.
Watch the part where Marlin says "Is this where we meet his teacher?" up to the part where Mr. Ray comes by, and Sheldon, the younger Seahorse, says to Nemo "C'mon Nemo." Listen for any mention of Nemo's name. How did Sheldon know Nemo's name? Is he psychic or Something?