<figure><img src="image_1.png" /></figure>

<figure><img src="image_2.png" /></figure>

<figure><img src="image_3.png" /></figure>

# New records and distribution extensions of the glassfrogs

*Hyalinobatrachium taylori* (Goin, 1968) and *H. tricolor* Castroviejo-Fisher, Vilà, Ayarzagüena, Blanc & Ernst, 2011 (Anura, Centrolenidae) in Amapá, Brazil

Carlos Eduardo Costa-Campos¹*, Davi Lee Bang², Vinícius Antônio Martins Barbosa de Figueiredo¹, Rodrigo Tavares-Pinheiro¹, Antoine Fouquet³

1. Departamento de Ciências Biológicas e da Saúde, Universidade Federal do Amapá, Macapá, AP, Brazil • CECC: eduardocampos@unifap.br • https://orcid.org/0000-0001-5034-9268 • VAMBF: viniciusantonio31@gmail.com • https://orcid.org/0000-0001-7895-8540 • RTP: rodrigo.tmcp@gmail.com • https://orcid.org/0000-0002-8021-9293

2. Departamento de Biologia, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brazil • davileebang@yahoo.com.br • https://orcid.org/0000-0002-5154-154X

3. Laboratoire Evolution et Diversité Biologique, Université Toulouse III, Toulouse, France • fouquet.antoine@gmail.com • https://orcid.org/0000-0003-4060-0281

* Corresponding author

## Abstract

Based on field surveys undertaken in two conservation areas, we report new distribution data of *Hyalinobatrachium taylori* (Goin, 1968) and *H. tricolor* Castroviejo-Fisher, Vilà, Ayarzagüena, Blanc & Ernst, 2011 from the state of Amapá, northern Brazil. We provide acoustic data from these new populations. These are the first records of *H. taylori* and *H. tricolor* from Amapá, extending the geographic distributions of these species by 317 km from Mitaraka and 320 km from Saut Grand Machicou, both in French Guiana, respectively.

## Keywords

Amazonia, bioacoustics, range extension, tropical rainforest

**Academic editor:** Thaís Guedes | Received 1 December 2020 | Accepted 27 January 2021 | Published 8 April 2021

**Citation:** Costa-Campos CE, Bang DL, Figueiredo VAMB, Tavares-Pinheiro R, Fouquet A (2021) New records and distribution extensions of the glassfrogs *Hyalinobatrachium taylori* (Goin, 1968) and *H. tricolor* Castroviejo-Fisher, Vilà, Ayarzagüena, Blanc & Ernst, 2011 (Anura, Centrolenidae) in Amapá, Brazil. Check List 17 (2): 637–642. https://doi.org/10.15560/17.2.637

## Introduction

The Neotropical amphibian family Centrolenidae, known as glassfrogs, encompasses 12 genera (Guayasamin et al. 2009), including *Hyalinobatrachium* Ruiz-Carranza & Lynch, 1991, which is represented by 33 species (Castroviejo-Fischer et al. 2011; Frost 2020). Six species of *Hyalinobatrachium* occur in Brazil (Segalla et al. 2019; *H. cappellei* (Van Lidth de Jeude, 1904), *H. carlesvilai*

Castroviejo-Fisher, Padial, Chaparro, Aguayo & De la Riva, 2009, *H. iaspidiense* (Ayarzaguena, 1992), *H. mon-dolfii* Señaris & Ayarzaguena, 2001, *H. muiraquitan* Oliveira & Hernández-Ruz, 2017, and *H. munozorum* (Lynch & Duellman, 1973). However, there are three species of *Hyalinobatrachium* occurring in French Guiana (Vacher et al. 2020) but unreported from the Brazilian
state of Amapá. As French Guiana borders Amapá, the presence of additional *Hyalinobatrachium* species in the state is likely (Silva e Silva and Costa-Campos 2016; Figueiredo et al. 2020).

Glassfrogs are nocturnal and associated with riparian vegetation; they generally deposit their clutches on plants or rocks overhanging water bodies (Noronha and Rodrigues 2018). On hatching, tadpoles drop into the water to complete their development (Kubicki 2007). The identification of closely related *Hyalinobatrachium* species can be challenging because they often have very similar morphology. Moreover, they are challenging to collect as they often call from the vegetation several meters above the water. Consequently, the geographic distributions of many species remain poorly documented (Silva e Silva and Costa-Campos 2016; Costa-Campos et al. 2020a, 2020b). Nevertheless, the examination of molecular and acoustic traits have fostered biodiscovery, the description of new species, and improved understanding of the geographic distribution of many species in this group (Kok and Castroviejo-Fisher 2008; Castroviejo-Fisher et al. 2011; Guayasamin et al. 2019).

*Hyalinobatrachium taylori* (Goin, 1968) is a small glassfrog having a snout–vent length (SVL) in adult males of 18.1–19.4 mm and in females of 20.6 mm

(Castroviejo-Fisher et al. 2011). This species usually uses vegetation 2–30 m above streams for reproduction. Egg clutches are deposited on the undersides of leaves, and males call on the upper sides. This species occurs along New River, Guyana (coordinates not available for the type locality; Castroviejo-Fisher et al. 2011) and occupies a wide distribution from the western tepuis (table-top mountains found in the Guiana Highlands) to the eastern Guiana Shield at elevations of 200–2000 m and the Amazonia–Cerrado ecotone. It has been found in French Guiana, Guyana, Venezuela, Suriname, and adjacent Brazil (Noonan and Bonett 2003; Castroviejo-Fisher et al. 2011; Frost 2020; Silva et al. 2020; Vacher et al. 2020).

*Hyalinobatrachium tricolor* Castroviejo-Fisher, Vilà, Ayarzagüena, Blanc & Ernst, 2011 is a small glassfrog (SVL 20.3–21.0 mm in adult males; unknown in females; Castroviejo-Fisher et al. 2011). Males call on vegetation 4–5 m above streams 0.5–1.5 m in depth. The species was described from Crique Wapou, Kaw, French Guiana and occurs at low elevation (0–100 m) (Castroviejo-Fisher et al. 2011; Vacher et al. 2020).

Here, we report the first records of both *H. taylori* and *H. tricolor* from the state of Amapá, northern Brazil, and we provide acoustic data from these newly found populations.

<figure><img src="image_4.png" /><figcaption>**Figure 1.** Known records of *Hyalinobatrachium taylori* (black circles) and *H. tricolor* (white circles). White square: type locality in Crique Wapou, Kaw, French Guiana (*H. tricolor*); *H. taylori* coordinates not available for type locality (Castroviejo-Fisher et al. 2011). Diamond: the occurrence in Tocatins may be a different species. New data for *H. taylori* (yellow star) and *H. tricolor* (white star) at Pedra Branca do Ampari and Serra do Navio, respectively, Amapá, Brazil (see Table 1 for details).</figcaption></figure>
Methods

We conducted nocturnal visual encounter surveys for amphibians at two locations in Amapá, northern Brazil: Parque Natural Municipal do Cancão, municipality of Serra do Navio, on 7–12 March 2018, and Reserva Extragenvista Beija-Flor Brilho de Fogo, municipality of Pedra Branca do Amapari, on 20–25 May 2019 (Fig. 1, Table 1).

Collected specimens were sacrificed using 5% lido-caine chlorhydrate, fixed in 10% formalin solution, and preserved in 70% ethanol. The specimens were collected under the Instituto Chico Mendes de Conservação da Biodiversidade/Sistema de Autorização e Informação em Biodiversidade (ICMBio/SISBIO permit #48102-2), and for each individual we collected muscle tissue samples before fixing the specimens and storing in 100% ethanol. We identified specimens of *H. taylori* and *H. tricolor* using the original species' descriptions by Castroviejo-Fisher et al. (2011). To confirm our identifications we checked acoustic parameters, because morphological characters are not sufficient to distinguish centrolenid species from one another (Castroviejo-Fisher et al. 2011). Specimens are deposited in the Herpetological Collection of the Universidade Federal do Amapá (CECC).

**Bioacoustics.** Vocalizations were recorded using a Marantz PMD 670 digital recorder (sampling rate: 44.1

kHz; resolution: 16 bits) and a Sennheiser ME67/K6 uni-directional microphone. Microphone was positioned at approximately 1 m from calling individuals. Bioacoustic analysis were conducted in Raven Pro v. 1.6 (Bioacoustics Research Program - Raven Pro 2019) with the following settings: window type Hann and Fast Fourier Transform (FFT) of 1024 samples; 3 dB filter bandwidth of 61.9 Hz; time grid resolution with overlap of 90%, and hop size of 2.31 ms; frequency grid resolution with discrete Fourier transform of 1024 and grid spacing of 44.1 Hz. Temporal measurements were manually obtained from the oscillogram and spectral measurements from the spectrogram. The following acoustic traits were measured following Castroviejo-Fisher et al. (2011): call duration; number of notes; note duration; interval between notes (i.e., silent period from the end of a note to the beginning of the next one); minimum, maximum, and dominant frequency (obtained with frequency 5%, 95%, and peak frequency functions, respectively). Harmonics were observed in calls of both species, but we refrained from measuring frequency values of harmonics in calls of *H. taylori*, as we observed artifacts in the spectrogram (i.e., aliasing) due to saturation of the microphone during recording; this could lead to spurious interpretation of these frequency components. Sound figures were generated in R v. 4.0.2 (R Development Core Team 2019) using Seewave (Sueur et al. 2008)

<table><caption>**Table 1.** Geographic coordinates from literature records and field surveys. * = type locality; coordinates of the type locality of *H. taylori* are not available. All coordinates use the WGS84 datum.</caption><thead><tr><th>Country</th><th>State, locality</th><th>Latitude</th><th>Longitude</th><th>Species</th><th>Source</th></tr></thead><tbody><tr><td>Brazil</td><td>Amapá, Pedra Branca do Amapari, Reserva Extragenvista Beija-Flor Brilho de Fogo</td><td>00.791°N</td><td>051.978°W</td><td><i>H. taylori</i></td><td>This study</td></tr><tr><td>Brazil</td><td>Roraima, Serra da Mocidade</td><td>01.600°N</td><td>061.885°W</td><td><i>H. taylori</i></td><td>Moraes et al. 2017</td></tr><tr><td>Brazil</td><td>Roraima, Serra da Mocidade</td><td>01.700°N</td><td>061.768°W</td><td><i>H. taylori</i></td><td>Moraes et al. 2017</td></tr><tr><td>Brazil</td><td>Roraima, Serra da Mocidade</td><td>01.700°N</td><td>061.785°W</td><td><i>H. taylori</i></td><td>Moraes et al. 2017</td></tr><tr><td>Brazil</td><td>Pacaraima</td><td>04.469°N</td><td>061.136°W</td><td><i>H. taylori</i></td><td>Vacher et al. 2020</td></tr><tr><td>Brazil</td><td>Tocantins, Palmas, Taquaruçu</td><td>10.296°S</td><td>048.128°W</td><td><i>H. taylori</i></td><td>Silva et al. 2020</td></tr><tr><td>French Guiana</td><td>Chutes Voltaire</td><td>05.029°N</td><td>054.089°W</td><td><i>H. taylori</i></td><td>Vacher et al. 2020</td></tr><tr><td>French Guiana</td><td>Trinité, Crique Grand Leblond</td><td>04.669°N</td><td>053.269°W</td><td><i>H. taylori</i></td><td>Castroviejo-Fisher et al. 2011</td></tr><tr><td>French Guiana</td><td>Mitaraka</td><td>02.235°N</td><td>054.449°W</td><td><i>H. taylori</i></td><td>Fouquet et al. 2019</td></tr><tr><td>French Guiana</td><td>Montagne de Fer</td><td>05.407°N</td><td>053.554°W</td><td><i>H. taylori</i></td><td>Vacher et al. 2020</td></tr><tr><td>Guyana</td><td>Kaieteur National Park</td><td>05.166°N</td><td>059.483°W</td><td><i>H. taylori</i></td><td>Castroviejo-Fisher et al. 2011</td></tr><tr><td>Suriname</td><td>Sipaliwini, Apalagadi</td><td>02.170°N</td><td>056.099°W</td><td><i>H. taylori</i></td><td>Vacher et al. 2020</td></tr><tr><td>Venezuela</td><td>Amazonas, Cerro Marahuaca</td><td>03.524°N</td><td>065.708°W</td><td><i>H. taylori</i></td><td>Castroviejo-Fisher et al. 2011</td></tr><tr><td>Venezuela</td><td>Amazonas, Cerro Duida</td><td>03.316°N</td><td>065.217°W</td><td><i>H. taylori</i></td><td>Castroviejo-Fisher et al. 2011</td></tr><tr><td>Venezuela</td><td>Auyan-tepui, Campamento Guayaraca</td><td>05.685°N</td><td>062.525°W</td><td><i>H. taylori</i></td><td>Castroviejo-Fisher et al. 2011</td></tr><tr><td>Venezuela</td><td>Auyan-tepui, central-west sector of Auyan-tepui</td><td>05.933°N</td><td>062.535°W</td><td><i>H. taylori</i></td><td>Castroviejo-Fisher et al. 2011</td></tr><tr><td>Venezuela</td><td>Bolívar, La Escalera</td><td>05.959°N</td><td>061.391°W</td><td><i>H. taylori</i></td><td>Castroviejo-Fisher et al. 2011</td></tr><tr><td>Venezuela</td><td>Bolívar, Quebrada Jaspe</td><td>05.933°N</td><td>062.100°W</td><td><i>H. taylori</i></td><td>Castroviejo-Fisher et al. 2011</td></tr><tr><td>Venezuela</td><td>Bolívar, Salto Karuay</td><td>05.690°N</td><td>061.861°W</td><td><i>H. taylori</i></td><td>Guayasamin et al. 2008</td></tr><tr><td>Venezuela</td><td>San Ignacio de Yuraní</td><td>04.916°N</td><td>061.083°W</td><td><i>H. taylori</i></td><td>Castroviejo-Fisher et al. 2011</td></tr><tr><td>Brazil</td><td>Amapá, Serra do Navio, Parque Natural Municipal do Cancão</td><td>00.911°N</td><td>052.012°W</td><td><i>H. tricolor</i></td><td>This study</td></tr><tr><td>French Guiana</td><td>Kaw, Montagne</td><td>04.550°N</td><td>052.160°W</td><td><i>H. tricolor</i></td><td>Castroviejo-Fisher et al. 2011</td></tr><tr><td>French Guiana</td><td>Régina, Canal de Kaw</td><td>04.500°N</td><td>052.016°W</td><td><i>H. tricolor</i></td><td>Castroviejo-Fisher et al. 2011</td></tr><tr><td>French Guiana</td><td>Régina, Crique Patawa</td><td>04.505°N</td><td>052.091°W</td><td><i>H. tricolor</i></td><td>Castroviejo-Fisher et al. 2011</td></tr><tr><td>French Guiana</td><td>Régina, Crique Wapou</td><td>04.433°N</td><td>052.150°W</td><td><i>H. tricolor</i>*</td><td>Guayasamin et al. 2008</td></tr><tr><td>French Guiana</td><td>Régina, Crique Wapou</td><td>04.400°N</td><td>052.150°W</td><td><i>H. tricolor</i></td><td>Castroviejo-Fisher et al. 2011</td></tr><tr><td>French Guiana</td><td>Régina, Rivière de Kaw</td><td>04.600°N</td><td>052.050°W</td><td><i>H. tricolor</i></td><td>Castroviejo-Fisher et al. 2011</td></tr><tr><td>French Guiana</td><td>Roura, Kaw Mountain</td><td>04.533°N</td><td>052.216°W</td><td><i>H. tricolor</i></td><td>Castroviejo-Fisher et al. 2011</td></tr><tr><td>French Guiana</td><td>Saut Grand Machicou</td><td>03.897°N</td><td>052.583°W</td><td><i>H. tricolor</i></td><td>Vacher et al. 2020</td></tr></tbody></table>
and tuneR (Ligges et al. 2018) packages with the fol-
lowing settings: window Hann, overlap = 90%, and FFT
size = 1024. Acoustic recordings were deposited in the
Fonoteca Neotropical Jacques Vielliard (FNJV).

Results

*Hyalinobatrachium taylori* (Goin, 1968)

Figures 1, 2A

**New record.** BRAZIL • Amapá, municipality of Pe-
dra Branca do Amapari, Reserva Extrativista Beija-
Flor Brilho de Fogo, Água Fria stream; 00.7918°N,
051.9783°W; 110 m elev.; 25.V.2019; Carlos E. Costa-
Campos leg.; found at night (21:00 h) perched on a leaf
>1.5 m above the stream; CECC 3274, 1 adult ♂, SVL
19.0 mm.

**Identification.** The following combination of phenotypic
characters differentiates *H. taylori* from all other conge-
neric species: green bones in life, iris grey with black re-
ticulations, dorsum dark green (Castroviejo-Fisher et al.

2011). Our recordings of the advertisement call is also
distinctive, showing values within the range of variation
as described in the original description for call duration
(0.652–1.052 s), number of notes (5–9), and dominant
frequency (4010.0–4350.0 Hz) described by Castroviejo-
Fisher et al. (2011).

**Advertisement call.** Call duration is 0.393–0.489 s (mean = 0.447, SD = 0.049, *n* = 3; Fig. 2A). Each call is composed of 6 or 7 notes (mean = 7, SD = 0.6) with visible harmonics. Each note duration is 0.024–0.046 s (mean = 0.039, SD = 0.005, *n* = 20), with intervals between notes of 0.013–0.050 s (mean = 0.033, SD = 0.011, *n* = 17). Frequency bandwidth is narrow, with minimum frequency ranging from 3876.0 to 4005.2 Hz (mean = 3947.8, SD = 65.8, *n* = 3) maximum frequency from 4177.4 to 4220.5 Hz (mean = 4206.1, SD = 24.9, *n* = 3), and dominant frequency from 4091.3 to 4134.4 Hz (mean = 4120.0, SD = 24.9, *n* = 3), corresponding to the first harmonic. Recording = FNJV 46269.

<figure><img src="image_5.png" /><figcaption>**Figure 2.** Spectrograms and respective oscillograms of the advertisement calls. **A. Hyalinobatrachium taylori** (21:00 h on 25 May 2019; ambient temperature 24.3 °C), at Pedra Branca do Amapari. **B. H. tricolor** (19:45 h on 11 February 2018; ambient temperature 25.6 °C) at Serra do Navio. Spectrograms were generated with a gray scale in which black = 0 dB.</figcaption></figure>
*Hyalinobatrachium tricolor* Castroviejo-Fisher, Vilà, Ayarzagüena, Blanc & Ernst, 2011

Figures 1, 2B

**New record.** BRAZIL • Amapá, municipality of Serra do Navio, village of Pedra Preta; Amapari River; 00.9008°N, 052.0134°W; 140 m elev.; 11.II.2018; Jackson C. Sousa leg.; found at night (19:45 h) on leaves on vegetation 3.5 m above the ground; CECC 2949, 1 adult ♂, SVL 20.6 mm.

**Identification.** The following combination of phenotypic characters differentiates *H. tricolor* from all other congeneric species: bones white in life, dorsum in life light green with lime green and brown patches and brown. Its advertisement call also has a multi-note structure and also showed values within the range of variation for call duration (0.19–0.20 s), number of notes (4), and dominant frequency (4628.11–4903.07 Hz) described by Castroviejo-Fisher et al. (2011).

**Advertisement call.** Call duration is 0.219–0.220 s (mean = 0.219, SD = 0.001, *n* = 2; Fig. 2B). Each call is composed of four notes with visible harmonics. Each note duration is 0.007–0.020 s (mean = 0.012, SD = 0.005, *n* = 6), with intervals between notes of 0.033–0.079 s (mean = 0.057, SD = 0.019, *n* = 17). Frequency bandwidth is narrow ranging from 4565.0 to 4866.5 Hz (*n* = 2), and dominant frequency from 4694.2 to 4737.3 Hz (mean = 4715.7, SD = 30.5, *n* = 2), corresponding to the first harmonic. Recording = FNJV 46270.

Discussion

Calls of both *Hyalinobatrachium* species reported herein are in agreement with the unique multi-note pattern and other acoustic traits described for *H. taylori* and *H. tricolor* (Castroviejo-Fisher et al. 2011). Thus, the calls provide unambiguous evidence for the identification of the populations reported here. These records represent the first reports for *H. taylori* and *H. tricolor* in Amapá. We found *H. taylori* in a primary forest without anthropogenic disturbance, while *H. tricolor* was recorded in a riparian zone on the right bank of the Amapari River, which has some anthropic disturbance. *Hyalinobatrachium taylori* and *H. tricolor* are Least Concern according to the International Union for the Conservation of Nature Red List (IUCN SSC Amphibian Specialist Group 2018, 2020a). *Hyalinobatrachium taylori* has been reported from the state of Tocantins (Silva et al. 2020). This is the southernmost occurrence of this species and would seem to represent a disjunct population, as it is 1,500 km from populations of *H. taylori* in French Guiana, Suriname, Guyana, and Venezuela. Silva et al. (2020) did not include call data and discussed the possibility that this Tocantins population could represent a distinct, yet undescribed species. Our records of *H. taylori* in Amapá, however, is much closer to populations occurring in French Guiana, Suriname, Guyana, and Venezuela. Our new record of *H. taylori* extends the geographic

distribution of this species southeast by approximately 317 km from Mitaraka, French Guiana, the closest previously known occurrence. The new record of *H. tricolor* is 320 km from Saut Grand Machicou, French Guiana. Our new records suggest that these species may be more widespread on the Guiana Shield than previously assumed (Castroviejo-Fisher et al. 2011). Additional sampling effort would probably find other populations in the areas between the previously known occurrences and our new record of *H. tricolor*.

Acknowledgements

Fundação de Amparo à Pesquisa do Estado de São Paulo currently provides a doctoral fellowship to DLB (FAPESP process #2017/27137-7). This work has benefited from an Investissement d'Avenir grant managed by the Agence Nationale de la Recherche (CEBA ref. ANR-10-LABX-25-01). Finally, we are indebted to Thaís Guedes and the anonymous reviewers for providing helpful comments that improved the manuscript.

Authors’ Contributions

CECC, VAMBF, and RTP conducted the fieldwork, collected the specimens, and wrote the text. AF revised the manuscript. DLB conducted bioacoustic analysis. VAMBF and CECC made the map and photographed the specimens. All authors have read and approved the submitted manuscript.

References

Ayarzagüena J (1992) Los centrolenidos de la Guayana Venezolana. Publicaciones de la Asociación de Amigos de Doñana 1. Sevilla, Spain, 1–46.

Bioacoustics Research Program - Raven Pro (2019) Interactive Sound Analysis Software (version 1.6). http://www.birds.cornell.edu/raven. The Cornell Lab of Ornithology, Ithaca, USA. Accessed on: 2020-08-20.

Castroviejo-Fisher S, Padial JM, Chaparro JC, Aguayo-Vedia CR, De la Riva I (2009) A new species of *Hyalinobatrachium* (Anura: Centrolenidae) from the Amazonian slopes of the central Andes, with comments on the diversity of the genus in the area. Zootaxa 2143 (1): 24–44. https://doi.org/10.11646/zootaxa.2143.1.2

Castroviejo-Fisher S, Vilà C, Ayarzagüena J, Blanc M, Ernst R (2011) Species diversity of *Hyalinobatrachium* glassfrogs (Amphibia: Centrolenidae) from the Guiana Shield, with the description of two new species. Zootaxa 3132 (1): 1–55. https://doi.org/10.11646/zootaxa.3132.1.1

Costa-Campos CE, Tavares-Pinheiro R, Castroviejo-Fisher S (2020a) Amphibia, Anura, Centrolenidae, *Cochranella resplendens* (Lynch & Duellman, 1973): first record from Brazil and updated map of the geographic distribution. Check List 16 (4): 847–851. https://doi.org/10.15560/16.4.847

Costa-Campos CE, Figueiredo VAMB, Lima JRF, Lima JD (2020b) New record and distribution map of the glassfrog *Vitreorana ritae* (Lutz, 1952) (Anura: Centrolenidae) from Amapá state, eastern Amazon. Herpetology Notes 13: 733–737.

Figueiredo VAMB, Tavares-Pinheiro R, Freitas AP, Dias-Souza MR, Costa-Campos CE (2020) First records of the glass frogs *Hyalinobatrachium cappellei* (van Lidth de Jeude, 1904) and *H. mondol-
fii Señaris & Ayarzagüena, 2001 (Anura, Centrolenidae) in the state of Amapá, Brazil. Check List 16 (5): 1369–1374. https://doi.org/10.15560/16.5.1369

Fouquet A, Vidal N, Dewynter M (2019) The amphibians of the Mita-raka massif, French Guiana. Zoosystema 41 (1): 359–374. https://doi.org/10.5252/zoosystema2019v41a19

Frost DR (2020) Amphibian species of the world: an online reference. Version 6.0. http://research.amnh.org/herpetology/amphibia/index.html. American Museum of Natural History, New York, USA. Accessed on: 2020-09-25.

Goin CJ (1968) A new centrolenid frog from Guyana. Quarterly Journal of the Florida Academy of Sciences 30:115–118.

Guayasamin JM, Castroviejo-Fisher S, Ayarzagüena J, Trueb L, Vilà C (2008) Phylogenetic relationships of glassfrogs (Centrolenidae) based on mitochondrial and nuclear genes. Molecular Phylogenetics and Evolution 48: 574–595. https://doi.org/10.7717/peerj.5856

Guayasamin JM, Castroviejo-Fisher S, Trueb L, Ayarzagüena J, Rada M, Vilà C (2009) Phylogenetic systematics of glassfrogs (Amphibia: Centrolenidae) and their sister taxon *Allophryne ruthveni*. *Zootaxa* 2100: 1–97. https://doi.org/10.11646/zootaxa.2100.1.1

IUCN SSC Amphibian Specialist Group (2018) *Hyalinobatrachium tricolor*. The IUCN Red List of threatened species 2018: e.T45727683A45727686. International Union for the Conservation of Nature, Gland, Switzerland. http://doi.org/10.2305/iucn.uk.2018-1.rlts.t45727683a45727686.en. Accessed on: 2021-1-8.

IUCN SSC Amphibian Specialist Group (2020) *Hyalinobatrachium taylori*. The IUCN Red List of threatened species 2020: e.T55034A109532153. International Union for the Conservation of Nature, Gland, Switzerland. https://doi.org/10.2305/iucn.uk.2020-2.rlts.t55034a109532153.en. Accessed on: 2021-1-8.

Kok PJR, Castroviejo-Fisher S (2008) Glassfrogs (Anura: Centrolenidae) of Kaieteur National Park, Guyana, with notes on the distribution and taxonomy of some species of the family in the Guiana Shield. *Zootaxa* 1680 (1): 25–53. https://doi.org/10.11646/zootaxa.1680.1.2

Kubicki B (2007) Ranas de vidrio de Costa Rica/Costa Rica glass frogs. Editorial INBio, Santo Domingo de Heredia, Costa Rica, 304 pp.

Ligges U, Krey, S, Mersmann O, Schnackenberg S (2018) TuneR: Analysis of Music and Speech. https://CRAN.R-project.org/package=tuneR. Accessed on: 2020-08-21.

Lynch JD, Duellman WE (1973) A review of the centrolenid frogs of Ecuador, with descriptions of new species. Occasional Papers of the Museum of Natural History, University of Kansas 16: 1–66.

Moraes LJCL, Almeida AP, Fraga R, Rojas RR, Pirani RM, Silva AAA, Carvalho VT, Gordo M, Werneck FP (2017) Integrative overview of the herpetofauna from Serra da Mocidade, a granitic mountain range in northern Brazil. ZooKeys 715: 103–159. https://doi.org/10.3897/zookeys.715.20288

Noonan BP, Bonett RM (2003) A new species of *Hyalinobatrachium* (Anura: Centrolenidae) from the Highlands of Guyana. Journal of Herpetology 37: 91–97. https://doi.org/10.1670/0022-1511(2003)037[0091:ansoha]2.0.co;2

Noronha JC, Rodrigues DJ (2018) Reproductive behaviour of the glass frog *Hyalinobatrachium cappellei* (Anura: Centrolenidae) in the southern Amazon, Journal of Natural History 52: 207–224. https://doi.org/10.1080/00222933.2017.1414324

Oliveira AE, Hernández-Ruz EJ (2017) New species of glassfrog, genus *Hyalinobatrachium* (Anura: Centrolenidae), for the Brazilian Amazon revealed by mitochondrial DNA and morphology. International Journal of Research Studies in Biosciences 5 (3): 41–52. http://doi.org/10.20431/2349-0365.0503007

R Development Core Team (2019) A Language and Environment for Statistical Computing. Version 3.6.1. http://www.R-project.org. Accessed on: 2020-08-21.

Ruiz-Carranza PM, Lynch JD (1991) Ranas Centrolenidae de Colombia I. Propuesta de una nueva clasificación genérica. Lozania 57: 1–30.

Segalla MV, Caramaschi U, Cruz CAG, Garcia PCA, Grant T, Haddad CFB, Santana DJ, Toledo LF, Langone JA (2019) Brazilian amphibians: list of Species. Herpetologia Brasileira 8: 65–96.

Señaris JC, Ayarzagüena J (2001) Una nueva especie de rana de cristal del género *Hyalinobatrachium* (Anura: Centrolenidae) del delta del río Orinoco, Venezuela. Revista de Biología Tropical 49: 1083–1093.

Silva e Silva YB, Costa-Campos, CE (2016) *Hyalinobatrachium ias-pidiense* (Ayarzagüena, 1992) (Anura: Centrolenidae): first record in Amapá state, Brazil and geographic distribution map. Check List 12 (2): 1849. http://doi.org/10.15560/12.2.1849

Silva LA, Carvalho PS, Pereira EA, Fadel RM, Dantas SP, Brandão RA, Santana DJ (2020) Richness, diversity patterns, and taxonomic notes of amphibians from the Tocantis state. Biota Neotropica 20 (1): e20190838. http://doi.org/10.1590/1676-0611-bn-2019-0838

Sueur J, Aubin T, Simonis C. (2008) Seewave, a free modular tool for sound analysis and synthesis. Bioacoustics 18: 213–226. https://doi.org/10.1080/09524622.2008.9753600

Vacher J.-P, Chave J, Ficetola F, Sommeria-Klein G, Tao S, Thébaud C, Blanc M, Camacho A, Cassimiro J, Colston R, Gaucher P, Gomes JO, Jairam R, Kok PJR, Lima JD, Martinez Q, Marty C, Noonan BP, Nunes P, Ouboter P, Recoder R, Rodrigues M., Snyder A, Marques de Souza S, Fouquet A (2020) Large-scale DNA-based survey of frogs in Amazonia suggests a vast underestimation of species richness and endemism. Journal of Biogeography 47 (8): 1781–1791. http://doi.org/10.1111/jbi.13847

Van Lidth de Jeude TW (1904) Reptiles and batrachians from Suriname. Notes from the Leyden Museum 25: 83–94.