Fig. 1

Astyanax caves, cavefish populations, and habitats. a A map showing the distribution of caves in the El Abra region of Tamaulipas and San Luis Potosí, Mexico. Boxes outlined in blue, red, and green show locations of Astyanax caves (black outlined and colored spheres) in the Sierra de Guatemala, Sierra de El Abra, and Micos regions, respectively. Inset: Mexico map showing the locations of A. mexicanus cavefish in the El Abra epicenter (right shaded rectangle) and A. aeneus cavefish in Guerrero (left shaded sphere). b Most frequently studied cavefish populations in the Guatemala (blue label), El Abra (red labels), and Micos (green label) regions. c A surface fish habitat at El Nacimiento del Río Choy. d A cavefish habitat in El Sótano de Las Piedras