Mexican cave fish through phylogenetic systematics

Abstract

Cave fishes are an excellent model for the study of phenotypic evolution, due to the high association between their phenotype and the extreme environment in which they evolved. Adaptation in these organisms has occurred as a response to selection pressures, reflecting in phenotypic changes associated with their particular strategy of life in darkness. Within a phylogenetic systematics framework, these adaptations are recognized as convergences or evolutionary parallelisms. Cave fishes from México are represented in six of 10 orders of Actinopterygii, presenting different degrees of troglomorphism related to their isolation time within caves, and although most of them came from freshwater, a few may be of marine origin. In this context, the phylogenies have had important implications for the taxonomy and evolution of these fishes.