Vieja melanurus

Vieja melanurus, widely known as the Red-tailed Cichlid or Red-tailed Goodeid, is a large and visually striking species from the Usumacinta and Grijalva river systems of Mexico and Guatemala. Adult males in breeding condition undergo a remarkable colour transformation — the posterior body and unpaired fins flush with vivid red to orange-red, contrasting with the greenish-silver anterior. This sexually dimorphic display is among the most dramatic of any Central American cichlid. A herbivore that will destroy plants, it is best kept in a large, robustly decorated aquarium.