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.[1] They are high-bodied cichlids that reach lengths of up to 17–35 cm (7–14 in) depending on the exact species.[2]Vieja feed mostly on vegetable matter, but may also take small invertebrates.[2]
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.[1][3]
There are currently 8 recognized species in the genus Vieja:[2]
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.[4] 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.[5]
Because of individual, regional and age-related variations, definite separation of some species can be difficult.[6] Furthermore, hybrids occur, sometimes even between a Vieja species and a species from another heroine genus.[7] The enigmatic Amphilophus margaritifer, sometimes still recognized as a valid species, is most likely a hybrid involving Thorichthys and Vieja.[3][8]
^McMahan, C.D.; Murray, C.M.; Geheber, A.D.; Boeckman, C.D.; Piller, K.R. (2011). "Paraneetroplus synspilus is a Junior Synonym of Paraneetroplus melanurus (Teleostei: Cichlidae)". Zootaxa. 2833: 1–14. doi:10.11646/ZOOTAXA.2833.1.1.
^Gómez-González, A.E.; Álvarez, F.; Matamoros, W.A.; Velázquez-Velázquez, E.; Schmitter-Soto, J.J.; González-Díaz, A.A.; McMahan, C.D. (2018). "Redescription of Vieja hartwegi (Taylor & Miller 1980) (Teleostei: Cichlidae) from the Grijalva River basin, Mexico and Guatemala, with description of a rheophilic morph". Zootaxa. 4375 (3): 371–391. doi:10.11646/zootaxa.4375.3.5. PMID29690077.
