EUGERRES CASTROAGUIRREI GONZÁLEZ-ACOSTA ET RODILES-HERNÁNDEZ, 2013 IS A JUNIOR SYNONYM OF EUGERRES MEXICANUS (STEINDACHNER, 1863) (ACTINOPTERYGII: PERCIFORMES: GERREIDAE)

The Lacandon mojarra, Eugerres castroaguirrei Gonzalez-Acosta et Rodiles-Hernandez, 2013, was described from the Grijalva-Usumacinta River basin (Mexico). According to the diagnosis E. castroaguirrei differs from the only other freshwater Gerreidae, the Mexican mojarra, Eugerres mexicanus by the combination of certain morphological characters. However, a comparison of materials obtained in the Usumacinta River, besides of type materials and other preserved specimens, yielded contradictory results. Therefore, the objective of this paper was to clearly determine if E. mexicanus and E. castroaguirrei are subjective synonyms applying morphological and molecular analyses. A total of 44 specimens were included in this study including the specimens collected specifically for this study, the type and non-type materials of Eugerres castroaguirrei from Coleccion de Peces de El Colegio de la Frontera Sur, Unidad San Cristobal, Chiapas, Mexico, and the types of Eugerres mexicanus, belonging to the Museum of Natural History, Wien, Austria. The authors' morphological and molecular genetics analyses demonstrated that E. mexicanus and E. castroaguirrei are subjective synonyms, therefore, Eugerres mexicanus must be considered a valid species name, and Eugerres castroaguirrei Gonzalez-Acosta et Rodiles-Hernandez, 2013 a junior synonym.