Calls and tadpoles of the species of Lysapsus (Anura, Hylidae, Pseudae)

Larval and bioacoustical characters are crucial for anuran systematics. Nevertheless, advertisement calls and larval morphology of most Neotropical anuran species are unknown. Lysapsus is a peculiar group of aquatic frogs that have been subject to recurrent taxonomic changes. Recent molecular phylogenetic and external morphology work gave support for some of the recognized species ( L. laevis and L. caraya ), but considerable doubt remains over the distinction among L. limellum and L. bolivianus . We describe the tadpoles of L. caraya and L. bolivianus , the advertisement call of L. laevis , and redescribe the advertisement calls of L. caraya , L. limellum , and L. bolivianus . Our results support the genus based on larval and bioacoustical characters. Lysapsus caraya and L. laevis have distinct advertisement calls, but no visual or statistically significant differences were observed between advertisement calls of L. limellum and L. bolivianus . Tadpoles of L. caraya , L. limellum , and L. bolivianus are similar based on external morphology and contrast against the distinct tadpole of L. laevis . Considerable doubt is raised on the validity of L. bolivianus , which either is a junior synonym of L. limellum or constitutes a cryptic species based on currently available data. Data on osteology, musculature, and chondrocranium, allied to robust phylogeographic analyses will help clarify the taxonomic status of these two putative species and the biogeographic relationships between the Amazon and the Paraná River basins.