Integrative taxonomy reveals a new but common Neotropical treefrog, hidden under the name Boana xerophylla

Abstract

Boana xerophylla is a common treefrog widely distributed in northern Brazil, Colombia, French Guiana, Guyana, Panama, Suriname, Trinidad and Tobago, and Venezuela. A recent study found molecular, acoustic, and morphometric differences between the populations located on opposite sides of the Orinoco River. Here, we carry out an updated molecular phylogenetic analysis, including new samples from all the countries along the distribution area, and analyzed additional call recordings from Brazil, Colombia, French Guiana, Panama, Trinidad and Tobago, and Venezuela. Our phylogenetic inference reveals three geographically restricted lineages: one in the eastern Guiana Shield (corresponding to B. xerophylla sensu stricto), another in the western Guiana Shield, and a third one north of the Orinoco River. Morphological and acoustic data agree with the differentiation between the populations north of the Orinoco River and the eastern Guiana Shield despite the low genetic p-distances observed (16S rRNA: 0.7–2.2 %). We argue that the populations north of the Orinoco River correspond to a new species, sister of B. xerophylla. We name and describe Boana platanera sp. nov. from the southern versant of the Cordillera de Mérida (08º48’26’’ N, 70º30’46’’ W, WGS 84; 947 m asl), Venezuela, and refer all the populations north of the Orinoco River currently identified as B. xerophylla to this species. The new species can be readily diagnosed from B. xerophylla (characters of the latter in parentheses) by a pale orange-yellow or light brown dorsal coloration (dark brown to green), palpebral membrane with dark pigments (pigments absent); pericloacal region dark brown (cream), advertisement call with shorter first note length than B. xerophylla. This study represents an empirical example regarding false negatives behind genetic thresholds for species discovery, appraising the use of integrative taxonomic approaches.

Unveiling the evolutionary relationships and the high cryptic diversity in Andean rainfrogs (Craugastoridae: Pristimantis myersi group)

“…We recognize the existence of sister species of amphibians exhibiting very low genetic distances, but they typically are further supported by the congruence of other lines of evidence, such as bioacoustics, and morphometry ( e.g. , Escalona et al, 2021 ). Given that we were unable to assess additional evidence on this issue, and faced with the impossibility of ruling out that the specimen QCAZ 11677 has been wrongly determined by Rojas-Runjaic & Guayasamin (2015) , we conservatively referred it as part of P. festae .…”

“…, Padial & De la Riva, 2009 ; Ortega-Andrade et al., 2015 ) and other Neotropical frogs often differ by genetic distances <3% ( e.g. , Coloma et al, 2012 ; Funk, Caminer & Ron, 2012 ; Jungfer et al, 2013 ; Caminer & Ron, 2014 ; Blotto et al, 2021 ; Escalona et al, 2021 ).…”

Phenotypic and genomic diversification with isolation by environment along elevational gradients in a neotropical treefrog

“…These mountains are often interrupted by lowland valleys and highland ridgelines, where environmental factors like temperature change rapidly along elevation gradients but not with latitude. In Colombia, Boana platanera is distributed from sea level to 2,100 m (Bernal & Lynch, 2008) across the Orinoco River basin, the Eastern and Central Cordilleras, including the inter-Andean warm Magdalena river valley, and the northern lowlands next to the Panama border (Escalona et al, 2021). In central Colombia, it inhabits the tropical seasonal forests of the Magdalena River Valley below 1,000 m and the tropical moist forests along the slopes and foothills of the Eastern and Central Cordilleras above 1,000 m. Hence, B. platanera experiences wide topographic and environmental heterogeneity, with smooth transitions between biogeographic regions but abrupt changes across canyons between mountains along the same Cordillera, and this geographic distribution of environmental heterogeneity creates and excellent system for examining ecological drivers of IBE and factors underlying potential local adaptation.…”

“…S1). We sampled B. platanera individuals close to small streams or ponds in the typical habitats of this species, including farmlands, relatively disturbed and open zones, and other nonforested areas (Escalona et al, 2021;Orrico et al, 2017).…”

“…Frogs are humidity-dependent (Duellman & Trueb, 1994;Wells, 2007) and temperature sensitive organisms (Bovo et al, 2018;Corn, 2005;Li et al, 2013) that have low vagility (Beebee, 2005;Duellman & Trueb, 1994) and high site fidelity (Zeisset & Beebee, 2008). The banana tree-dwelling frog Boana platanera (Escalona et al, 2021) -just recently changed from Boana xerophylla (Duméril & Bibron, 1841)-is a nocturnal Neotropical treefrog with a wide distribution, ranging from north of the Orinoco River in Venezuela to Panama, Trinidad and Tobago and Colombia, below 2,450 m (Escalona et al, 2021;Orrico et al, 2017). It exhibits sexual dimorphism, where females are larger than males, as well as geographic phenotypic variation (Duellman, 1997;Orrico et al, 2017).…”