El hueso urohial de los peces Gerreidae (Teleostei: Percoidei) de América y su aplicación taxonómica

The urohyal is a single bone of dermal origin, located in the center of the lower jaw bones of teleostean fishes, which represents the original point for the function of the mouth-opening mechanism. The comparative study of the urohyal morphology in American gerreids supports the idea that this bony structure shows different forms that might be of great usefulness for the taxonomic discrimination among genera, and even species. This study provides the description of morphological characteristicas of the urohyal bone, that allows these to be distinguished among five selected species representatives of four genera of American gerreids: Diapterus (D. brevirostris), Eucinostomus (E. dowii), Eugerres (E. lineatus and E. mexicanus) and Gerres (G. cinereus).