Here is an exerpt from an article in Science News. They mention Moleno and Tiaja as Mexican caves where the samples were taken. The link for the article is below but you will have to subscribe to see it.
Keep them in the dark for a million years. Then cross two strains of cave-dwelling fish, now totally blind. It turns out some of their kids will be able to see. Fish and other creatures lose their sight after generations living in caves. Yet working vision genes from one parent can partly make up for defunct versions from the other parent, at least in young fish, reports Richard Borowsky of New York University. The vision rescue experiment works only if mom and dad come from different caves, says Borowsky. http://www.sciencenews.org/articles/20080112/fob5.asp ........ Sam