Competition between Color Morphs of the Polychromatic Midas Cichlid Cichlasoma citrinellum

+ See all authors and affiliations

Science  23 Feb 1973:
Vol. 179, Issue 4075, pp. 806-807
DOI: 10.1126/science.179.4075.806


The Midas cichlid, Cichlasoma citrinellum, is a polychromatic fish that occurs in Nicaragua. All of these fish start life as normally colored, cryptic individuals. In some populations a few fish change into conspicuously colored morphs, most frequently gold. When kept in unmixed color groups, golds and normals grow at the same rate; but when they are mixed, growth of the golds becomes faster and that of the normals slower. Golds dominate normals in contests over food, which accounts for their advantage.

Related Content