Tadpole of the Amazonia frog Edalorhina perezi (Anura: Leptodactylidae) with description of oral internal and chondrocranial morphology

Abstract

The genus Edalorhina consists of two species of small forest-floor frogs inhabiting the Amazon basin. The tadpole of Edalorhina perezi, the most widely distributed species, was previously described based on a single and early stage (Gosner 25) individual. Herein, we provide a description of the tadpole in Gosner stages 35-36 including internal morphology data (i.e., buccopharyngeal cavity and larval skeleton) based on samples from two populations from Ecuador. Edalorhina shares a generalized morphology with most members of its closely related taxa; however, it is distinguished from the other species by having an almost terminal oral disc. The presence of a dextral vent tube is considered a synapomorphy for the clade consisting of Edalorhina, Engystomops, and Physalaemus. Within this clade, the combination of two lingual papillae, a filiform median ridge, and the lack of buccal roof papillae are diagnostic of E. perezi and putative autapomorphies of Edalorhina. Chondrocranial anatomy provides characteristics, that is, presence of and uniquely shaped processus pseudopterygoideus and cartilago suprarostralis with corpora and alae joined by dorsal and ventral connections that readily differentiates the genus from other Leiuperinae.

Larval morphology of Amazonia foam‐nesting frogs of the genus Engystomops (Anura: Leptodactylidae: Leiuperinae)

“…Engystomops shares with most Physalaemus and Edalorhina the presence of a dextral vent tube, corroborating a previous hypothesis that this trait is a synapomorphy for the clade formed by these three genera(Nascimento et al, 2021) and supporting the evolutionary proximity between Engystomops and Physalaemus as already evi-…”

“…The buccal features of Engystomops are similar to those of Physalaemus tadpoles (see Appendix 5 in Nascimento et al, 2021). Nevertheless, the overall shape of the lateral ridge papillae seems to distinguish these two genera.…”

“…The buccal features of Engystomops are similar to those of Physalaemus tadpoles (see Appendix 5 inNascimento et al, 2021).Nevertheless, the overall shape of the lateral ridge papillae seems to distinguish these two genera. Engystomops shows a triangular or trapezoidal (flap-like) lateral ridge papillae, whereas in Physalaemus these papillae can be bifurcated or trifurcated (chela-shaped).…”

“…Engystomops, it appears independently in Pleurodema nebulosum (Wasserssug & Heyer, 1988), Edalorhina perezi (Nascimento et al, 2021) and in members of Physalaemus biligonigerus species group (Nomura et al, 2003;Perotti & Céspedez, 1999;Sandoval, 2002).…”

“…Nascimento et al, 2021). For outgroup we included members of the subfamily Paratelmatobiinae, the sister clade of Leiuperinae:Rupirana cardosoi, Scythroprys sawayae, Crossodactylodes itambe, and Paratelmatobius poecilogaster (housed in the Tadpole Collection of the Universidade Federal de Minas Gerais, Belo Horizonte, Brazil; Engystomops guayaco (n = 3; stages 31-34) Total length 16.7 ± 1.5 mm (15.0-18.1 mm) (Figure 2a).…”