Fig. 1

Map of Central Mexico, showing locations where Gyrodactylus tomahuac n. sp. was collected. The red star shows the type-locality of G. tomahuac n. sp. at Vega de Ramírez, Río Moctezuma, Querétaro (Qro). Río Moctezuma is a tributary of the Río Pánuco (shown in blue), the only major river from the Mesa Central (MC) that drains into the Gulf of Mexico. Locations where G. tomahuac n. sp. and other gyrodactylids were collected from Goodea atripinnis in the Río Lerma-Santiago basin, which drains the MC into the Pacific Ocean, are shown with letters: A, Araro, Michoacán; C, Lago de Chapala, Jalisco; F, El Fresno, Guanajuato; M, San Miguel Tlaxcaltepec, Qro; S, Santiago Mezquititlán, Qro