Melamed and Barca defender Gerard Pique were sent off late in the game and Araujo was seen taunting the striker.
"Melamed, to the Segunda, to the Segunda...", Araujo was seen shouting at the Espanyol player.
Hours later, Araujo apologised for the incident: "I want to apologise to all the people of Espanyol for the unfortunate gesture I had tonight.
"It was all the result of the tension experienced during a derby as disputed as today's.
"I consider myself a respectful person with the fans and rival clubs; and for that reason I am not proud of what happened."