Morfologia larval, vocalizações e posicionamento filogenético de crossodactylus dantei carcerelli e caramaschii, 1993 (Anura, Hylodidae)

Abstract

Aspects of the biology and natural history of the endemic anuran Crossodactylus dantei remain unknown even after about 30 years since its description. In this study, we describe for the first time its larval stage, the advertisement and territorial calls, and determine its phylogenetic placement based on a fragment of the 16S rRNA mitochondrial gene. The larval stage of C. dantei follows the morphological pattern of Hylodidae, corroborating the relatively uniform larval morphology of the family. However, it is still possible to observe characters that distinguish C. dantei from other species in the genus, such as the elliptical body in dorsal view, nostrils located closer to the snout than the eyes, an elongated pre-nasal arena, and the absence of taenia tecti medialis and taenia tecti transversalis in the chondrocranium. Its advertisement call is characterized by a sequence of about 23 pulsed notes, with ascending amplitude modulation, lasts a mean of 2.5 seconds and a dominant frequency of 3356 Hz. The territorial call has a mean duration of 23 seconds, a dominant frequency of 3160 Hz, and two distinct types of notes. Phylogenetic analysis indicated the existence of two main lineages in the genus. Crossodactylus dantei was recovered with high statistical support as a sister species to the clade composed of C. gaudichaudii and C. timbuhy. Furthermore, the group formed by these three species was recovered as the sister lineage of C. trachystomus. In summary, the information presented here represents a significant advance in the knowledge of this enigmatic and rare species of the Northern Atlantic Forest. The description of its larval stage and vocalizations provides important baseline data for future ecological and evolutionary studies of this unique anuran species.