On the occurrence of Scinax kennedyi (Pyburn, 1973) (Anura, Hylidae) in the state of Roraima, northern Brazil

Abstract

Scinax comprises 129 species of treefrogs divided between the S. ruber and the S. catharinae clades. The S. rostratus group belongs to the S. ruber clade, and comprises ten species characterized by having a dark interorbital triangular mark, tubercle on the heel and by vocalizing in a head-down position. Within this group, S. kennedyi and S. rostratus are similar in that they are the only species that do not possess a row of tubercles on the lower jaw. In spite of their morphological similarity, they can be distinguished from each other by male size and advertisement call traits. Scinax kennedyi was described from eastern Colombia, and occurs from central Colombia to western Venezuela, whereas S. rostratus was described from northern Venezuela, and is thought to occur from Panama to eastern Venezuela, and in the Brazilian state of Pará. A recent study reported a population identified as S. rostratus from the state of Roraima, in northern Brazil. However, this population presented substantial differences in male size and advertisement call in comparison to the described for this species, and apparently it best fits the diagnosis of S. kennedyi instead. In view of this, the present study aimed to clarify the identity of this Brazilian population through a reassessment of its specimens and call recordings, together with the examination of data of S. kennedyi from its type locality, and of S. rostratus from northern Venezuela. Acoustic and morphological analyses revealed that specimens from northern Brazil were indeed misidentified as S. rostratus, and hence they were herein reassigned to S. kennedyi. The study therefore demonstrates the occurrence of S. kennedyi in Brazil, extending its distribution ca. 1,120 km east by south from its type locality, and ca. 844 km east-southeast from its easternmost previous record. With this reassessment, a clearer acoustic diagnosis between S. kennedyi and S. rostratus was provided, as well as further data on fine-scale temporal traits of their calls.

Treefrog Diversity in the Neotropics: Phylogenetic Relationships of Scinaxini (Anura: Hylidae: Hylinae)

“…6. Lopes and Giaretta (2022) reported similar calls for topotypes of S. kennedyi and specimens from Roraima (Brazil). The identity of these latter requires corroboration, considering the occurrence of Scinax sp.…”

“…The UPDs between these species are 2.4–4.2% (Appendix S10: Table 22). Lopes and Giaretta (2022) reported some differences in call structure between S. kennedyi and specimens of S. rostratus from Guaraúnos, Sucre (Venezuela; about 400 km E Caracas, the type locality).…”

“…The UPDs between these species are 2.4−4.2% (Appendix S10: Table 22). Lopes and Giaretta (2022) reported 14 The fragment of the 16S sequence of the specimen from Orocué, Casanare (Colombia) is very short, so we excluded it from the UPD calculation. However, when the alignment is trimmed so only comparable fragments of the three available samples of Scinax sp.…”