Which character from the adventure film "Finding Nemo" suffers from short-term memory loss?

"Finding Nemo" is a 2003 American computer-animated adventure film produced by Pixar Animation Studios and released by Walt Disney Pictures. It tells the story of the overprotective clownfish named Marlin who, along with a regal blue tang named Dory, a regal blue tang with short-term memory loss, searches for his abducted son Nemo all the way to Sydney Harbour. Along the way, Marlin learns to take risks and comes to terms with Nemo taking care of himself. "Finding Nemo" won the Academy Award and Saturn Award for Best Animated Film.