Explore the vast range of titles available.

The genus Nymphargus is the most speciose of the family Centrolenidae with 44 species. In this study, we describe a new species of Nymphargus and present an updated phylogeny. The new species is sister to an undescribed species, also from SW Ecuador, and both belong to a clade that includes N. buenaventura , N. cariticommatus , N. griffithsi , N. lasgralarias , N. sucre , and N. wileyi . The new species likely originated during the Pliocene (~4.5 Mya) and is characterized by a uniformly green dorsum lacking spots, shagreened dorsal skin, and white peritonea covering the esophagus and stomach. Our phylogeny provides, for the first time, the phylogenetic position of N. buenaventura . The new species was discovered at Reserva Biológica El Quimi, during expeditions by the QCAZ Museum in 2017 and 2018. Most amphibian species found at that location were undescribed, indicating that some regions of Cordillera del Cóndor host amphibian communities that have remained as “hidden worlds” for biological exploration.

Scinax is a speciose genus of Neotropical hylid frogs. We describe a new species from western Ecuador (elevations between 0 and 1207 m) using morphology, vocalizations, and DNA sequences. We also present a new phylogeny for Scinax based on mitochondrial DNA genes 12S rRNA, Cytochrome Oxidase sub-unit I, Cytochrome B, 16S rRNA, NADH dehydrogenase subunit 1, and adjacent tRNAs. The new species, Scinax tsachila sp. nov. was previously confused with S. quinquefasciatus, a morphologically similar sympatric species. They differ by having markedly different advisement calls, distinct skin texture in the dorsum, and different bone coloration. The new species is sister to S. elaeochroa, a species that differs in advertisement call and color pattern. We provide an updated species account for Scinax quinquefasciatus and a redescription of its holotype.

Molecular phylogenies have yielded strong support for many parts of the amphibian Tree of Life, but poor support for the resolution of deeper nodes, including relationships among families and orders. To clarify these relationships, we provide a phylogenomic perspective on amphibian relationships by developing a taxon-specific Anchored Hybrid Enrichment protocol targeting hundreds of conserved exons which are effective across the class. After obtaining data from 220 loci for 286 species (representing 94% of the families and 44% of the genera), we estimate a phylogeny for extant amphibians and identify gene tree–species tree conflict across the deepest branches of the amphibian phylogeny. We perform locus-by-locus genealogical interrogation of alternative topological hypotheses for amphibian monophyly, focusing on interordinal relationships. We find that phylogenetic signal deep in the amphibian phylogeny varies greatly across loci in a manner that is consistent with incomplete lineage sorting in the ancestral lineage of extant amphibians. Our results overwhelmingly support amphibian monophyly and a sister relationship between frogs and salamanders, consistent with the Batrachia hypothesis. Species tree analyses converge on a small set of topological hypotheses for the relationships among extant amphibian families. These results clarify several contentious portions of the amphibian Tree of Life, which in conjunction with a set of vetted fossil calibrations, support a surprisingly younger timescale for crown and ordinal amphibian diversification than previously reported. More broadly, our study provides insight into the sources, magnitudes, and heterogeneity of support across loci in phylogenomic data sets.

Genetic data in studies of systematics of Amazonian amphibians frequently reveal that purportedly widespread single species in reality comprise species complexes. This means that real species richness may be significantly higher than current estimates. Here we combine genetic, morphological, and bioacoustic data to assess the phylogenetic relationships and species boundaries of two Amazonian species of the Dendropsophus leucophyllatus species group: D. leucophyllatus and D. triangulum. Our results uncovered the existence of five confirmed and four unconfirmed candidate species. Among the confirmed candidate species, three have available names: Dendropsophus leucophyllatus, Dendropsophus triangulum, and Dendropsophus reticulatus, this last being removed from the synonymy of D. triangulum. A neotype of D. leucophyllatus is designated. We describe the remaining two confirmed candidate species, one from Bolivia and another from Peru. All confirmed candidate species are morphologically distinct and have much smaller geographic ranges than those previously reported for D. leucophyllatus and D. triangulum sensu lato. Dendropsophus leucophyllatus sensu stricto occurs in the Guianan region. Dendropsophus reticulatus comb. nov. corresponds to populations in the Amazon basin of Brazil, Ecuador, and Peru previously referred to as D. triangulum. Dendropsophus triangulum sensu stricto is the most widely distributed species; it occurs in Amazonian Ecuador, Peru and Brazil, reaching the state of Pará. We provide accounts for all described species including an assessment of their conservation status.

We review the systematics of the Hypsiboas calcaratus species complex, a group of widely distributed Amazonian hylid frogs. A comprehensive analysis of genetic, morphological, and bioacoustic datasets uncovered the existence of eleven candidate species, six of which are confirmed. Two of them correspond to Hypsiboas fasciatus and Hypsiboas calcaratus and the remaining four are new species that we describe here. Hypsiboas fasciatus sensu stricto has a geographic range restricted to the eastern Andean foothills of southern Ecuador while Hypsiboas calcaratus sensu stricto has a wide distribution in the Amazon basin. Hypsiboas almendarizae sp. n. occurs at elevations between 500 and 1950 m in central and northern Ecuador; the other new species (H. maculateralis sp. n., H. alfaroi sp. n., and H. tetete sp. n.) occur at elevations below 500 m in Amazonian Ecuador and Peru. The new species differ from H. calcaratus and H. fasciatus in morphology, advertisement calls, and mitochondrial and nuclear DNA sequences. Five candidate species from the Guianan region, Peru, and Bolivia are left as unconfirmed. Examination of the type material of Hyla steinbachi, from Bolivia, shows that it is not conspecific with H. fasciatus and thus is removed from its synonymy.

Pluralistic approaches to taxonomy facilitate a more complete appraisal of biodiversity, especially the diversification of cryptic species. Although species delimitation has traditionally been based primarily on morphological differences, the integration of new methods allows diverse lines of evidence to solve the problem. Robber frogs (Pristimantis) are exemplary, as many of the species show high morphological variation within populations, but few traits that are diagnostic of species. We used a combination of DNA sequences from three mitochondrial genes, morphometric data, and comparisons of ecological niche models (ENMs) to infer a phylogenetic hypothesis for the Pristimantis acuminatus complex. Molecular phylogenetic analyses revealed a close relationship between three new species-Pristimantis enigmaticus sp. nov., P. limoncochensis sp. nov. and P. omeviridis sp. nov.-originally confused with Pristimantis acuminatus. In combination with morphometric data and geographic distributions, several morphological characters such as degree of tympanum exposure, skin texture, ulnar/tarsal tubercles and sexual secondary characters (vocal slits and nuptial pads in males) were found to be useful for diagnosing species in the complex. Multivariate discriminant analyses provided a successful classification rate for 83-100% of specimens. Discriminant analysis of localities in environmental niche space showed a successful classification rate of 75-98%. Identity tests of ENMs rejected hypotheses of niche equivalency, although not strongly because the high values on niche overlap. Pristimantis acuminatus and P. enigmaticus sp. nov. are distributed along the lowlands of central-southern Ecuador and northern Peru, in contrast with P. limoncochensis sp. nov. and P. omeviridis sp. nov., which are found in northern Ecuador and southern Colombia, up to 1200 m in the upper Amazon Basin. The methods used herein provide an integrated framework for inventorying the greatly underestimated biodiversity in Amazonia.

Pristimantis is the most diverse genus of tetrapods comprising 532 described species. It contains a large number of morphologically cryptic species that are being discovered with the assistance of genetic evidence. We use molecular, morphological, bioacoustic, and environmental data to assess the phylogenetic relationships and determine the species within an Andean clade of Pristimantis , which is distributed from central Ecuador to northern Peru. We assign to this clade the name Huicundomantis and propose it as a subgenus. Our results show that Huicundomantis is composed of two large clades which we name as the P.phoxocephalus species group and the P.cryptomelas species group. Huicundomantis is composed of 28 species of which 12 have been described and 16 are new. We describe 11 of these undescribed species. The most effective characters to discriminate among species are DNA sequences, qualitative morphology, and advertisement calls. Morphometric and environmental characters are not very useful to define species limits. We clarify the identity of P.riveti and show that populations from southern Ecuador traditionally ascribed to P.riveti are a new species, P.lutzae sp. nov. We also show that P.prometeii is a junior synonym of P.hampatusami . The current diversity and geographic distribution of Huicundomantis are consistent with a model of allopatric speciation. All species have a restricted distribution range (less than 4330 km 2 ) and are assigned to the Red List categories Data Deficient or threatened with extinction. We provide new reasons to increase conservation efforts for these species and their habitat. Taking our results into account, Pristimantis species richness in Ecuador increases from 211 to 221 species, and the number of species endemic to Ecuador from 119 to 129.

Although biologists have described biofluorescence in a diversity of taxa, there have been few systematic efforts to document the extent of biofluorescence within a taxonomic group or investigate its general significance. Through a field survey across South America, we discover and document patterns of biofluorescence in tropical amphibians. We more than triple the number of anuran species that have been tested for this trait. We find evidence for ecological tuning (i.e., the specific adaptation of a signal to the environment in which it is received) of the biofluorescent signals. For 56.58% of species tested, the fluorescence excitation peak matches the wavelengths most abundant at twilight, the light environment in which most frogs are active. Additionally, biofluorescence emission spans both wavelengths of low availability in twilight and the peak sensitivity of green-sensitive rods in the anuran eye, likely increasing contrast of this signal for a conspecific receiver. We propose an expanded key for testing the ecological significance of biofluorescence in future studies, providing potential explanations for the other half of fluorescent signals not originally meeting formerly proposed criteria. With evidence of tuning to the ecology and sensory systems of frogs, our results suggest frog biofluorescence is likely functioning in anuran communication. The significance of biofluorescence across taxonomic groups is understudied. Here the authors document biofluorescence in South American tropical amphibians, suggesting that biofluorescence corresponds with wavelengths of light at twilight and may be used in communication.

Amphibians are probably the most vulnerable group to climate change and climate-change associate diseases. This ongoing biodiversity crisis makes it thus imperative to improve the taxonomy of anurans in biodiverse but understudied areas such as Amazonia. In this study, we applied robust integrative taxonomic methods combining genetic (mitochondrial 16S, 12S and COI genes), morphological and environmental data to delimit species of the genus Amazophrynella (Anura: Bufonidae) sampled from throughout their pan-Amazonian distribution. Our study confirms the hypothesis that the species diversity of the genus is grossly underestimated. Our analyses suggest the existence of eighteen linages of which seven are nominal species, three Deep Conspecific Lineages, one Unconfirmed Candidate Species, three Uncategorized Lineages, and four Confirmed Candidate Species and described herein. We also propose a phylogenetic hypothesis for the genus and discuss its implications for historical biogeography of this Amazonian group.

Management and conservation of biodiversity requires adequate species inventories. The Yasuní National Park is one of the most diverse regions on Earth and recent studies of terrestrial vertebrates, based on genetic evidence, have shown high levels of cryptic and undescribed diversity. Few genetic studies have been carried out in freshwater fishes from western Amazonia. Thus, in contrast with terrestrial vertebrates, their content of cryptic diversity remains unknown. In this study, we carried out genetic and morphological analyses on characin fishes at Yasuní National Park, in eastern Ecuador. Our goal was to identify cryptic diversity among one of the most speciose fish families in the Amazon region. This is the first time that genetic evidence has been used to assess the species content of the Napo Basin, one of the richest regions in vertebrate diversity. Phylogenetic analyses of partial mitochondrial 16S ribosomal RNA gene (∼600 pb) DNA sequences from 232 specimens of the family Characidae and its closest groups revealed eight candidate new species among 33 species sampled, representing a 24% increase in species number. Analyses of external morphology allowed us to confirm the species status of six of the candidate species. Our results show high levels of cryptic diversity in Amazonian characins. If this group is representative of other Amazonian fish, our results would imply that the species richness of the Amazonian ichthyofauna is highly underestimated. Molecular methods are a necessary tool to obtain more realistic inventories of Neotropical freshwater fishes.