Phylogenetic and biogeographic study of the Andean genus Grundulus (Teleostei: Characiformes: Characidae)

Abstract

We analyzed a matrix of 55 characters to study the phylogenetic relationships and historical biogeography of the three species of the genus Grundulus. The most parsimonious hypothesis explaining phylogenetic relationships of Grundulus species is expressed in a tree with a length of 84 steps, (consistency index 0.80, retention index 0.88, rescaled consistency index 0.70). The monophyly of a clade containing the Cheirodontinae and Grundulus is supported by fi ve synapomorphies; within this clade Grundulus is found to be the sister-group of Spintherobolus, as supported by nine synapomorphies. In the proposed hypothesis, the monophyly of Grundulus is supported by eleven synapomorphies and G. quitoensis is sister to a clade including G. cochae and G. bogotensis. The biogeographical analysis suggests that Grundulus is a genus endemic to coldwater lakes of glacial origin in the Andes of northern South America. The taxon-area cladogram shows a high congruence between the areas and phylogeny of the taxa, where each area harbors a particular species. The most closely related areas are La Cocha, a coldwater lake from the Amazon basin (A), and the Bogotá plateau from the Magdalena basin (B). The Pacifi c Andean region on Ecuador is the sister area of A and B.