A Genetic and Acoustic Evaluation of the Distribution of Hylodes sazimai Haddad & Pombal, 1995 (Hylodidae), a Stream-Dwelling Atlantic Forest Frog
We present evidence for an incorrect distribution record of Hylodes sazimai and provide a new record of it in the state of Minas Gerais Gerais based on genetic and acoustic data, revisiting the differential diagnosis among its closely related species. The new population is related to the H. sazimai topotypes, with no more than 0.6% of genetic distance. However, the population from Parque Nacional do Itatiaia (PARNA Itatiaia) has a genetic distance varying between 2.7% (2.7–2.8%) from topotypes and 3.3% (3.1–3.3%) from Poços de Caldas specimens. The comparison of these data with the distances between H. sazimai and the other closely related species shows that the population from PARNA Itatiaia is not H. sazimai, nor any other species included in this study. Topotypic H. sazimai has an advertisement call consisting of a sequence of approximately 26 notes lasting around 2 sec and emitted at a rate of 4 calls per minute and 12 notes per second. Hylodes sazimai from Poços de Caldas has an advertisement call consisting of a sequence of about 33 notes lasting around 2 sec and emitted at a rate of 5 calls per minute and 13 notes per second. The random forest approach did not reveal significant discrimination between the populations. Most call features were classified as dynamic for both populations. Because the taxonomic status of the PARNA Itatiaia population is not related to H. sazimai, we suggest a reduction of the northeastern distribution of the species, restricting it to the topotypic locality and Poços de Caldas. Our study reinforces the importance of integrative studies to solve biodiversity crypsis issues and emphasizes the use of detailed acoustic analysis as a powerful tool to diagnosing Hylodes species.ABSTRACT
Reviewed geographic distribution of Hylodes sazimai in southeastern Brazil. Gray scale indicates Brazil hypsometric levels; orange area corresponds to Mantiqueira Range; empty black arrows point to the Paraíba do Sul River Valley and main tributaries (pointed blue line) of the Paraíba do Sul River (solid blue line). Red circle: type locality (district of Joaquim Egídio, municipality of Campinas, São Paulo state); green circle: new record (this study, from municipality of Poços de Caldas, Minas Gerais state); black circle: Parque Nacional do Itatiaia, an historically admitted site for the species which is discarded by us (see Results).
Top: oscillogram of a 29-note advertisement call of a topotype Hylodes sazimai (municipality of Campinas, São Paulo state). Bottom: spectrogram and oscillogram of three median (12ª, 13ª and 14ª) notes (sound file: Hylodes_sazimaiSousasSP3bAAG.wav). For further information, see Appendix 3.
Top: oscillogram of a 37-note advertisement call of Hylodes sazimai (municipality of Poços de Caldas, Minas Gerais state). Bottom: spectrogram and oscillogram of three median notes (sound file: Hylodes_PocosCaldasMG1a_AAGmt.wav). For further information, see Appendix 3.
First and second dimensions of the multidimensional scale analysis on the proximity scores from the random forest analysis considering acoustic data of topotypes (“Camp”). Red dots (topotypes) and new recorded population, referred as “Poc,” in blue dots (municipality of Poços de Caldas, Minas Gerais state). Notice the lack of discrimination between populations.
Adult males of Hylodes sazimai in life. Top: AAG-UFU 0847, SVL = 25.6 mm, topotype, district of Joaquim Egídio, municipality of Campinas, São Paulo state. Bottom: AAG-UFU 0968, SVL = 25.7 mm, from municipality of Poços de Caldas, Minas Gerais state.
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