Vieja
Vieja is a genus of cichlid fish from Central America and Mexico. The majority of the species are freshwater fish found in stagnant or slow-moving waters of southern Mexico to El Salvador, but "V. maculicauda", which also occurs in brackish waters, ranges south to Panama. They are high-bodied cichlids that reach lengths of up to depending on the exact species. "Vieja" feed mostly on vegetable matter, but may also take small invertebrates. Taxonomy and species. Historically, "Vieja" was included in "Cichlasoma". Once recognized as its own genus, it sometimes included most of the superficially similar, relatively large  and high-bodied cichlids of Central America and southern Mexico, but several of these are now considered to belong to separate genera: "Chuco", "Cincelichthys", "Isthmoheros", "Kihnichthys", "Maskaheros" and "Oscura" ("Oscuro" might still be better merged with "Vieja", but this remains unconfirmed). Conversely, "Vieja" has sometimes been included in "Paraneetroplus". There are currently 8 recognized species in the genus "Vieja": In addition to these, two further species have commonly been recognized: The first is "V. coatlicue", but today it is usually considered the Atlantic slope population of "V. zonata". The second is "V. synspilum", in which case "V. melanurus" is limited  to the Lake Petén system, but a review found that the supposed differences between them are invalid. Because of individual, regional and age-related variations, definite separation of some species can be difficult. Furthermore, hybrids occur, sometimes even between a "Vieja" species and a species from another heroine genus. The enigmatic "Amphilophus margaritifer", sometimes still recognized as a valid species, is most likely a hybrid involving "Thorichthys" and "Vieja".