Size and estimated age of the fry captured in the Pachón cave. A Live Pachón fry photographed in a small fish aquarium, in the cave B Size/age relationship for lab-raised Pachón individuals with a linear regression curve. Data were collected in Rétaux’s lab from larvae, post-larvae and juvenile grown as described in Elipot et al. (2014), and which were fed twice a day with live Artemia, ad libitumC Photograph of a specimen swimming in the natural pool. Note the muddy/sandy substrate and the low water level D, E Photographs of live arthropod specimens cohabiting with Astyanax fry.