Larval morphology and phylogenetic placement of Boana exastis (Anura, Hylidae): a comparison with B. pardalis and B. lundii

The treefrog Boana exastis was tentatively included in B. faber group based on its morphological similarity to B. lundii and B. pardalis. This species was only recently included in a molecular phylogeny, confirming its placement in this group; however, its phylogenetic relationships have been poorly explored. Herein, we describe the larval external morphology, buccopharyngeal cavity, and skeleton of B. exastis, and assess its phylogenetic placement and genetic similarity between disjunct populations. Additionally, we describe the larval skeleton of the two closely related species, B. lundii and B. pardalis. The larval morphology of B. exastis is congruent with the other Boana species, reinforcing a high larval similarity across species of the B. faber group. The three species showed differences in color and in rows of marginal papillae. Comparing the chondrocranium of the three species, we found that B. exastis is more similar to B. pardalis than to B. lundii, contrary to what has been previously proposed, based on acoustic data. Phylogenetically, B. exastis was found to be more related to B. pardalis than to B. lundii. Despite presenting a disjunct distribution, the populations of Boana exastis show a very low mitochondrial genetic divergence, indicating that they are the same taxon.