Larval morphology of Dendropsophus tapacurensis (Amphibia: Anura: Hylidae) with considerations on Dendropsophini tadpoles

The Dendropsophus decipiens group comprises seven species with highly conserved morphology and deeply divergent molecular lineages. In this study, we describe the external and internal morphology of Dendropsophus tapacurensis , making considerations on Dendropsophini tadpoles. The tadpoles were collected in two different areas, including the type locality, the Estação Ecológica de Tapacurá, São Lourenço da Mata municipality, Pernambuco, Northeastern Brazil. Species confirmation was based on molecular data using the 16S gene. The description and morphometric measurements were based on nine tadpoles. The tadpoles were prepared for the description of internal oral morphology (four), chondrocranium, hyobranchial apparatus, and cranial muscles (three). Although tadpoles of the D. decipiens group are morphologically similar, D. tapacurensis differs from its congeners in color pattern, by having two dermal folds in the oral disc and a narrow lateral interruption in the marginal papillae. Dendropsophus tapacurensis differs from D. decipiens by presenting lingual papilla, papillae on the buccal floor, a pair of postnarial papillae, lateral roof papillae, larval otic process, and the lateral process of the ceratohyal, as well as by the absence of the basihyal. Despite the differences in the cranial and visceral skeletons, the cranial musculature is quite conserved between the two species. Although tadpoles in this group exhibit conserved external morphology, both external traits and internal anatomy offer useful characters for species identification and may contribute to resolving the group's taxonomy. Additionally, our findings help fill knowledge gaps regarding character evolution within the genus Dendropsophus and the tribe Dendropsophini.