I got this caption from aquariumlife.net under fish profiles...
RD's
Description: The Red Devil has a great deal of variability in its structure and coloration. Some are bright red while others are white or yellow. Some have black-tipped fins and tail with black lips, while others have thick rubbery lips. They are very "owner conscious" and will follow you when you walk in front of the aquarium and also respond to interactions like cleaning the aquarium and feeding. Although they can be kept in aquariums around 50 gallons, bigger aquariums can reduce their aggressiveness. They have been known to live with other fish, but will usually not tolerate the same, or other species of fish in the same aquarium. Very similar to Cichlasoma citrinellum, or Midas Cichlid, some sites still list them as the same fish. They are found in different places though, while the Red Devil is only found in the Nicaraguan lakes, Midas can ranges from Costa Rica to Nicaragua.