Red devil cichlids (Amphilophus labiatus) and Midas cichlids (Amphillophus citrinellus) often present the novice aquarist with difficulty in telling the two breeds apart. Singed with blazing orange contrasted with marbling of black or white, both species grow to similar lengths. Although young or juveniles are nearly impossible to distinguish from one another, you can easily tell whether a fish longer than 2 inches is a Midas or a red devil.
Big Mouths vs. Tight Lipped
The easiest way to tell if you have an adult red devil is to look at the mouth. Part of the fish's Latin name -- labiatis -- refers to the fish's large labia or lips. While the lips of the Midas cichlid will lie flat against the snout, the red devil's lips are pronounced and fleshy, extending well away from the surrounding skin. The mouth of the red devil is longer than that of the Midas as well as narrower from side to side.
Red devils have long foreheads that slope back from their snouts, while Midas cichlids' foreheads rise more abruptly. Mature Midas males commonly develop singular protrusions on their head known as nuchal humps. During courtship, a male's bump increases dramatically in size as the Midas fills it with water. The bump decreases after successful mating. Juvenile red devils commonly have black markings on their heads; they fade by the time they are ready to breed.
A red devil cichlid's body is long and streamlined, about three to four times as long as it is high. The length and the slightly elongated snout capped by the large lips contrast sharply with the Midas, whose body is half two-thirds as high as it is long. Capped with the bumpy head and the blunt, small-mouthed snout, the Midas has an all-around stockier appearance that sets the fish apart from the red devil.
Because these fish species are similar in size and coloration, they will mate with one another when adequate members of their own species are not available. You may encounter deeper bodied, big-lipped fish bearing characteristics of both species that represent hybridized fish inadvertently bred and sold by novice aquarists. Although red devils and Midas cichlids grow to similar size at 12 to 14 inches, it's best to keep the species separately to avoid hybridization.