Species richness under a vertebral stripe: integrative taxonomy uncovers three additional species of Pholidobolus lizards (Sauria, Squamata, Gymnophthalmidae) from the north-western Colombian Andes.

The systematic study of biodiversity underlies appropriate inference in most other fields of biological research, yet it remains hampered by disagreements on both theoretical and empirical issues such as the species concept and the operational diagnosis of a species. Both become particularly challenging in those lineages where morphological traits are evolutionarily constrained by their adaptive value. For instance, cryptic organisms often conserve or converge in their external appearance, which hinders the recognition of species boundaries. An integrative approach has been adopted to study microgeographic variation in the leaf-litter lizard Pholidobolusvertebralis and test three predictions derived from the evolutionary species concept. Molecular data provided unambiguous evidence of divergence among the three recovered new clades and a common evolutionary history for each of them. The broadly sympatric clades were indeed diagnosable from externally visible traits, such as head scales, adult size, and sexually dimorphic ventral colouration. Also, they barely overlapped on the phenotypic space that summarised 39 morphometric and meristic traits. These clades are described as three species and an available name is suggested for a recovered fourth clade. The geographic distribution of the new and proximate species suggests a role for elevation on evolutionary divergence; it also raises interesting questions on the speciation pattern of an otherwise underestimated cryptic lineage.

Heavy Metal Concentration in Neotropical Aquatic Snakes (Helicops pastazae) and Its Potential as a Bioindicator of Water Pollution.

The purpose of this study was to test the potential role of the aquatic snake Helicops pastazae as an indicator of water pollution caused by heavy metals. In particular, we tested whether the total heavy metal concentration is related to (1) the position (upstream vs downstream) of the sampling point and its distance from the point where wastewater is discharged; (2) the taxonomic group studied: piscivorous snakes vs characid fish that occupy the same habitats; and (3) the organ or tissue examined: snake liver versus muscle. We used atomic absorption spectrophotometry with electrothermal atomization to quantify cadmium (Cd), chromium (Cr) and lead (Pb) and found significant differences between some of the sampling points, with particularly high metal concentrations detected upstream at point 1. However, we found no clear spatial pattern nor any significant differences in the concentration of any of the metals in fish and snake muscle, suggesting that both species accumulate similar amounts of the sampled elements. With regard to interactions, snake liver had the highest concentrations of Cd, while muscle had the highest concentrations of Pb and Cr, which may indicate tissue affinity differences for certain metals. Altogether, our results indicate that H. pastazae accumulates contaminants differentially, depending on the tissue and location, which highlights their potential as bioindicators of water contamination. Further research is necessary to understand their role as bioindicators based on extensive sampling and environmental contaminant data.

First characterization of toxic alkaloids and volatile organic compounds (VOCs) in the cryptic dendrobatid Silverstoneia punctiventris.

BACKGROUND: Poison frogs are known for the outstanding diversity of alkaloid-based chemical defences with promising therapeutic applications. However, current knowledge about chemical defences in Dendrobatoidea superfamily has two sources of bias. First, cryptic, brown-colored species have been neglected in comparison to those conspicuously colored, and second, there has been little interest in characterizing metabolites other than alkaloids mediating defensive functions. In an effort to contribute to fill the gap of knowledge about cryptic species and broadening the spectrum of compounds analyzed we have applied head-space solid phase microextraction coupled to gas chromatography and mass spectrometry (HS-SPME/GC-MS) for extracting amphibian alkaloids and volatile organic compounds (VOCs) from Silverstoneia punctiventris. RESULTS: Using the skin from 8 specimens in 4 biological replicates we have found 33 different compounds. Twenty of them were classified as VOCs into 15 chemical classes including alkanes, alcohols, carbonyl compounds, methylpyridines, benzothiazoles, N-alkylpyrrolidines, pyrazines, and sesquiterpenoids, some of which were previously reported as repellents, defence compounds or defence pheromones in other organisms, and as sex pheromones in a treefrog. Interestingly, six of the remaining compounds were identified as alkaloids previously reported in other toxic/unpalatable dendrobatid frogs. CONCLUSIONS: This is the first report of alkaloids and VOCs found in the Silverstoneia genus, which has been assumed for decades as non-chemically defended. This study establishes HS-SPME/GC-MS as a new application for a simultaneous approach to amphibian alkaloids and VOCs in poison frogs while opens up new research questions to assess the co-occurrence of both type of compounds and to investigate the evolutionary significance of a defence gradient that includes olfactory avoidance, unpalatability, and toxicity in dendrobatids. In addition, our results show that amphibian alkaloids could have a dual function (olfactory at distance, taste by contact) never explored before neither in Silverstonaeia nor in any other dendrobatid species.

Auto-deconvolution and molecular networking of gas chromatography-mass spectrometry data.

We engineered a machine learning approach, MSHub, to enable auto-deconvolution of gas chromatography-mass spectrometry (GC-MS) data. We then designed workflows to enable the community to store, process, share, annotate, compare and perform molecular networking of GC-MS data within the Global Natural Product Social (GNPS) Molecular Networking analysis platform. MSHub/GNPS performs auto-deconvolution of compound fragmentation patterns via unsupervised non-negative matrix factorization and quantifies the reproducibility of fragmentation patterns across samples.

Adjusted phonotactic reactions to sound amplitude and pulse number mediate territoriality in the harlequin poison frog.

The information content of signals remains one of the central questions in animal communication. Auditory signals might contain information that allows receivers to estimate the distance as well as the size or the motivational state of senders. Proper differential reactions by receivers could be especially important for territorial species and lead to behavioural adjustments towards intruders according to the threat level: the perceived risk of losing territory. Therefore, territorial individuals should decode signal parameters that indicate the sender's size, distance, and motivation/treat level, reacting accordingly. To test this hypothesis, we studied the phonotactic reaction in territorial males of the poison frog Oophaga histrionica, after analyzing the variability of spectral and temporal parameters of natural calls. Next, we constructed synthetic calls by manipulating sound amplitude (sound pressure level: SPL), gross (inter-call intervals), and fine-temporal (number of pulses) structure of synthetic signals. In this way, we simulated near and far intruders with potentially variable sizes, motivational states, or threat levels. Then, we conducted playback experiments using these synthetic calls to determine 1) how perceived proximity of vocal competitors (determined by SPL) affect the behavior of receivers, and 2) how variation in the temporal structure of calls (inter-call interval and call pulse number) impact the behavior of receivers. We also asked whether signals convey body-size related information by analyzing the relationship between call parameters and body size of the males receiving the experimental stimuli. Consistent with our hypothesis, males recognized the variations in the SPL of calls. Males attacking the simulated opponent increased the number of pulses per call, while those retreating, kept pulse number unchanged (a graded aggressive signal). On the other hand, despite call traits resulted as poor predictors of body size, both SPL and fine temporal call traits might aid to predict whether a contestant will attack an opponent. Our data demonstrate that males discriminate and use SPL to estimate the sender's distance and use the call's fine temporal traits and to adjust the competitive/aggressive reaction using bimodal signals. They further suggest that body size assessment is not always an important factor in vocally- mediated agonistic interactions.

Analysis of Malassezia Lipidome Disclosed Differences Among the Species and Reveals Presence of Unusual Yeast Lipids.

Malassezia yeasts are lipid dependent and part of the human and animal skin microbiome. However, they are also associated with a variety of dermatological conditions and even cause systemic infections. How these yeasts can live as commensals on the skin and switch to a pathogenic stage has long been a matter of debate. Lipids are important cellular molecules, and understanding the lipid metabolism and composition of Malassezia species is crucial to comprehending their biology and host-microbe interaction. Here, we investigated the lipid composition of Malassezia strains grown to the stationary phase in a complex Dixon medium broth. In this study, we perform a lipidomic analysis of a subset of species; in addition, we conducted a gene prediction analysis for the detection of lipid metabolic proteins. We identified 18 lipid classes and 428 lipidic compounds. The most commonly found lipids were triglycerides (TAG), sterol (CH), diglycerides (DG), fatty acids (FAs), phosphatidylcholine (PC), phosphatidylethanolamine (PE), ceramides, cholesteryl ester (CE), sphingomyelin (SM), acylcarnitine, and lysophospholipids. Particularly, we found a low content of CEs in Malassezia furfur, atypical M. furfur, and Malassezia pachydermatis and undetectable traces of these components in Malassezia globosa, Malassezia restricta, and Malassezia sympodialis. Remarkably, uncommon lipids in yeast, like diacylglyceryltrimethylhomoserine and FA esters of hydroxyl FAs, were found in a variable concentration in these Malassezia species. The latter are bioactive lipids recently reported to have antidiabetic and anti-inflammatory properties. The results obtained can be used to discriminate different Malassezia species and offer a new overview of the lipid composition of these yeasts. We could confirm the presence and the absence of certain lipid-biosynthesis genes in specific species. Further analyses are necessary to continue disclosing the complex lipidome of Malassezia species and the impact of the lipid metabolism in connection with the host interaction.

Divergence, gene flow, and the origin of leapfrog geographic distributions: The history of colour pattern variation in Phyllobates poison-dart frogs.

The geographic distribution of phenotypic variation among closely related populations is a valuable source of information about the evolutionary processes that generate and maintain biodiversity. Leapfrog distributions, in which phenotypically similar populations are disjunctly distributed and separated by one or more phenotypically distinct populations, represent geographic replicates for the existence of a phenotype, and are therefore especially informative. These geographic patterns have mostly been studied from phylogenetic perspectives to understand how common ancestry and divergent evolution drive their formation. Other processes, such as gene flow between populations, have not received as much attention. Here, we investigate the roles of divergence and gene flow between populations in the origin and maintenance of a leapfrog distribution in Phyllobates poison frogs. We found evidence for high levels of gene flow between neighbouring populations but not over long distances, indicating that gene flow between populations exhibiting the central phenotype may have a homogenizing effect that maintains their similarity, and that introgression between 'leapfroging' taxa has not played a prominent role as a driver of phenotypic diversity in Phyllobates. Although phylogenetic analyses suggest that the leapfrog distribution was formed through independent evolution of the peripheral (i.e. leapfrogging) populations, the elevated levels of gene flow between geographically close populations poise alternative scenarios, such as the history of phenotypic change becoming decoupled from genome-averaged patterns of divergence, which we cannot rule out. These results highlight the importance of incorporating gene flow between populations into the study of geographic variation in phenotypes, both as a driver of phenotypic diversity and as a confounding factor of phylogeographic inferences.

The evolution of polymorphism in the warning coloration of the Amazonian poison frog Adelphobates galactonotus.

While intraspecific variation in aposematic signals can be selected for by different predatory responses, their evolution is also contingent on other processes shaping genetic variation. We evaluate the relative contributions of selection, geographic isolation, and random genetic drift to the evolution of aposematic color polymorphism in the poison frog Adelphobates galactonotus, distributed throughout eastern Brazilian Amazonia. Dorsal coloration was measured for 111 individuals and genetic data were obtained from 220 individuals at two mitochondrial genes (mtDNA) and 7963 Single Nucleotide Polymorphisms (SNPs). Four color categories were described (brown, blue, yellow, orange) and our models of frog and bird visual systems indicated that each color was distinguishable for these taxa. Using outlier and correlative analyses we found no compelling genetic evidence for color being under divergent selection. A time-calibrated mtDNA tree suggests that the present distribution of dorsal coloration resulted from processes occurring during the Pleistocene. Separate phylogenies based on SNPs and mtDNA resolved the same well supported clades, each containing different colored populations. Ancestral character state analysis provided some evidence for evolutionary transitions in color type. Genetic structure was more strongly associated with geographic features, than color category, suggesting that the distribution of color is explained by localized processes. Evidence for geographic isolation together with estimates of low effective population size implicates drift as playing a key role in color diversification. Our results highlight the relevance of considering the neutral processes involved with the evolution of traits with important fitness consequences.

A new species of Pristimantis (Anura: Craugastoridae) from the cloud forests of Colombian western Andes.

The frogs of the genus Pristimantis are recognized for their characteristic reproductive mode and for their incredible diversity of species, becoming the genus with the highest number of species within tetrapod vertebrates. We describe here a new species of Pristimantis from the northwestern Andes of Colombia. The species was found between 2000-2500 m.a.s.l., mostly within moss hanging of tree branches in a tropical cloud forest. It can be easily distinguished from other Pristimantis species of the western Andes by the unique black and white patterning in the ventral surface and the flanks, the hourglass-shaped dorsal folds, and the prominent conical tubercles on eyelids, heels, and outer edge of tarsus. A phylogenetic analysis further supports its status of a lineage reciprocally monophyletic to P. satagius and separated by a genetic distance of 0.03; the latter species bear whitish rather than predominantly black ventral coloration. To the best of our knowledge, this species is only known from the 2,500 ha nature reserve Mesenia-Paramillo, despite other research on this area of the country. Therefore, the species is declared vulnerable while new evidence on its distribution range is accumulated.

Microbiota and skin defense peptides may facilitate coexistence of two sympatric Andean frog species with a lethal pathogen.

Management of hyper-virulent generalist pathogens is an emergent global challenge, yet for most disease systems we lack a basic understanding as to why some host species suffer mass mortalities, while others resist epizootics. We studied two sympatric species of frogs from the Colombian Andes, which coexist with the amphibian pathogen Batrachochytrium dendrobatidis (Bd), to understand why some species did not succumb to the infection. We found high Bd prevalence in juveniles for both species, yet infection intensities remained low. We also found that bacterial community composition and host defense peptides are specific to amphibian life stages. We detected abundant Bd-inhibitory skin bacteria across life stages and Bd-inhibitory defense peptides post-metamorphosis in both species. Bd-inhibitory bacteria were proportionally more abundant in adults of both species than in earlier developmental stages. We tested for activity of peptides against the skin microbiota and found that in general peptides did not negatively affect bacterial growth and in some instances facilitated growth. Our results suggest that symbiotic bacteria and antimicrobial peptides may be co-selected for, and that together they contribute to the ability of Andean amphibian species to coexist with the global pandemic lineage of Bd.

Does batrachotoxin autoresistance coevolve with toxicity in Phyllobates poison-dart frogs?

Toxicity is widespread among living organisms, and evolves as a multimodal phenotype. Part of this phenotype is the ability to avoid self-intoxication (autoresistance). Evolving toxin resistance can involve fitness tradeoffs, so autoresistance is often expected to evolve gradually and in tandem with toxicity, resulting in a correlation between the degrees of toxicity and autoresistance among toxic populations. We investigate this correlation in Phyllobates poison frogs, notorious for secreting batrachotoxin (BTX), a potent neurotoxin that targets sodium channels, using ancestral sequence reconstructions of BTX-sensing areas of the muscular voltage-gated sodium channel. Reconstructions suggest that BTX resistance arose at the root of Phyllobates, coinciding with the evolution of BTX secretion. After this event, little or no further evolution of autoresistance seems to have occurred, despite large increases in toxicity throughout the history of these frogs. Our results, therefore, provide no evidence in favor of an evolutionary correlation between toxicity and autoresistance, which conflicts with previous work. Future research on the functional costs and benefits of mutations putatively involved in BTX resistance, as well as their prevalence in natural populations, should shed light on the evolutionary mechanisms driving the relationship between toxicity and autoresistance in Phyllobates frogs.

The effect of captivity on the skin microbial symbionts in three Atelopus species from the lowlands of Colombia and Ecuador.

Many amphibian species are at risk of extinction in their natural habitats due to the presence of the fungal pathogen Batrachochytrium dendrobatidis (Bd). For the most highly endangered species, captive assurance colonies have been established as an emergency measure to avoid extinction. Experimental research has suggested that symbiotic microorganisms in the skin of amphibians play a key role against Bd. While previous studies have addressed the effects of captivity on the cutaneous bacterial community, it remains poorly studied whether and how captive conditions affect the proportion of beneficial bacteria or their anti-Bd performance on amphibian hosts. In this study we sampled three amphibian species of the highly threatened genus, Atelopus, that remain in the wild but are also part of ex situ breeding programs in Colombia and Ecuador. Our goals were to (1) estimate the diversity of culturable bacterial assemblages in these three species of Atelopus, (2) describe the effect of captivity on the composition of skin microbiota, and (3) examine how captivity affects the bacterial ability to inhibit Bd growth. Using challenge assays we tested each bacterial isolate against Bd, and through sequencing of the 16S rRNA gene, we identified species from thirteen genera of bacteria that inhibited Bd growth. Surprisingly, we did not detect a reduction in skin bacteria diversity in captive frogs. Moreover, we found that frogs in captivity still harbor bacteria with anti-Bd activity. Although the scope of our study is limited to a few species and to the culturable portion of the bacterial community, our results indicate that captive programs do not necessarily change bacterial communities of the toad skins in a way that impedes the control of Bd in case of an eventual reintroduction.

Conspicuousness, color resemblance, and toxicity in geographically diverging mimicry: The pan-Amazonian frog Allobates femoralis.

Predation risk is allegedly reduced in Batesian and Müllerian mimics, because their coloration resembles the conspicuous coloration of unpalatable prey. The efficacy of mimicry is thought to be affected by variation in the unpalatability of prey, the conspicuousness of the signals, and the visual system of predators that see them. Many frog species exhibit small colorful patches contrasting against an otherwise dark body. By measuring toxicity and color reflectance in a geographically variable frog species and the syntopic toxic species, we tested whether unpalatability was correlated with between-species color resemblance and whether resemblance was highest for the most conspicuous components of coloration pattern. Heterospecific resemblance in colorful patches was highest between species at the same locality, but unrelated to concomitant variation in toxicity. Surprisingly, resemblance was lower for the conspicuous femoral patches compared to the inconspicuous dorsum. By building visual models, we further tested whether resemblance was affected by the visual system of model predators. As predicted, mimic-model resemblance was higher under the visual system of simulated predators compared to no visual system at all. Our results indicate that femoral patches are aposematic signals and support a role of mimicry in driving phenotypic divergence or mimetic radiation between localities.

The advertisement call of Ameerega pulchripecta (Silverstone, 1976)(Anura, Dendrobatidae).

The name Ameerega picta was once used to denote a lineage of poison frogs (Dendrobatidae) distributed throughout most of the Amazon basin (Silverstone 1976); more recently, to describe a phenetic group involving at least 18 species, Lötters et al. (2007) pointed out that some of the lineages were indeed derived from the former A. picta. Among them, the nominal species with the widest distribution is A. hahneli (Haddad & Martins 1994; Twomey & Brown 2008), also an alleged complex of poorly defined species (Grant et al. 2006; Fouquet et al. 2007; Roberts et al. 2007). The mate-recognition signal, the advertisement call, was part of the evidence used to revalidate A. hahneli as a different species from A. picta. Although the advertisement call has been described for one or few individuals of other species in the group (Haddad & Martins 1994; Costa et al. 2006; Twomey & Brown 2008; Lötters et al. 2009), namely A. flavopicta, A. braccata and A. boehmei, and A. hahneli, we still lack a formal description for A. pulchripecta, the sister taxon of A. hahneli (Twomey & Brown 2008). Its call has been qualitatively described as similar to A. hahneli's call, but "deeper-voiced" (Lötters et al. 2007).

Decoupled Evolution between Senders and Receivers in the Neotropical Allobates femoralis Frog Complex.

During acoustic communication, an audible message is transmitted from a sender to a receiver, often producing changes in behavior. In a system where evolutionary changes of the sender do not result in a concomitant adjustment in the receiver, communication and species recognition could fail. However, the possibility of an evolutionary decoupling between sender and receiver has rarely been studied. Frog populations in the Allobates femoralis cryptic species complex are known for their extensive morphological, genetic and acoustic variation. We hypothesized that geographic variation in acoustic signals of A. femoralis was correlated with geographic changes in communication through changes in male-male recognition. To test this hypothesis, we quantified male call recognition using phonotactic responses to playback experiments of advertisement calls with two, three and four notes in eight localities of the Amazonian basin. Then, we reconstructed the ancestral states of call note number in a phylogenetic framework and evaluated whether the character state of the most recent common ancestor predicted current relative responses to two, three and four notes. The probability of a phonotactic response to advertisement calls of A. femoralis males was strongly influenced by the call mid-frequency and the number of notes in most populations. Positive phonotaxis was complete for calls from each individual's population, and in some populations, it was also partial for allotopic calls; however, in two populations, individuals equally recognized calls with two, three or four notes. This evidence, in conjunction with our results from phylogenetic comparative methods, supports the hypothesis of decoupled evolution between sender and receiver in the male-male communication system of the A. femoralis complex. Thus, signal recognition appears to evolve more slowly than the calls.

Thermal ecology of montane Atelopus (Anura: Bufonidae): A study of intrageneric diversity.

Harlequin frogs (Bufonidae: Atelopus) are among the most threatened frog genus in the world and reach very high elevations in the tropical Andes and the Sierra Nevada de Santa Marta (SNSM). Learning about their thermal ecology is essential to infer sensitivity to environmental changes, particularly climate warming. We report on the activity temperature and thermoregulatory behavior of three high-elevation species of harlequin frogs, Atelopus nahumae, Atelopus laetissimus and Atelopus carrikeri. The first two mentioned live in streams in Andean rain forests, whereas A. carrikeri inhabits paramo streams in the SNSM. We studied the thermal ecology of these species in tree localities differing in altitude, and focused on activity body, operative, substrate and air temperature. A main trend was lower body temperature as elevation increased, so that differences among species were largely explained by differences in substrate temperature. However, this temperature variation was much lower in forest species than paramo species. The Atelopus species included in this work proved to be thermoconformers, a trend that not extended to all congenerics at high elevation. This diversity in thermal ecology poses important questions when discussing the impact of climate warming for high-elevation harlequin frogs. For example, forest species show narrow thermal ranges and, if highly specialized, may be more susceptible to temperature change. Paramo species such as A. carrikeri, in contrast, may be more resilient to temperature change.

Genotyping of Fusarium Isolates from Onychomycoses in Colombia: Detection of Two New Species Within the Fusarium solani Species Complex and In Vitro Antifungal Susceptibility Testing.

Fusariosis have been increasing in Colombia in recent years, but its epidemiology is poorly known. We have morphologically and molecularly characterized 89 isolates of Fusarium obtained between 2010 and 2012 in the cities of Bogotá and Medellín. Using a multi-locus sequence analysis of rDNA internal transcribed spacer, a fragment of the translation elongation factor 1-alpha (Tef-1α) and of the RNA-dependent polymerase subunit II (Rpb2) genes, we identified the phylogenetic species and circulating haplotypes. Since most of the isolates studied were from onychomycoses (nearly 90 %), we carried out an epidemiological study to determine the risk factors associated with such infections. Five phylogenetic species of the Fusarium solani species complex (FSSC), i.e., F. falciforme, F. keratoplasticum, F. lichenicola, F. petroliphilum, and FSSC 6 as well as two of the Fusarium oxysporum species complex (FOSC), i.e., FOSC 3 and FOSC 4, were identified. The most prevalent species were FOSC 3 (38.2%) followed by F. keratoplasticum (33.7%). In addition, our isolates were distributed into 23 haplotypes (14 into FOSC and nine into FSSC). Two of the FSSC phylogenetic species and two haplotypes of FSSC were not described before. Our results demonstrate that recipients of pedicure treatments have a lower probability of acquiring onychomycosis than those not receiving such treatments. The antifungal susceptibility of all the isolates to five clinically available agents showed that amphotericin B was the most active drug, while the azoles exhibited lower in vitro activity.

Hybridization promotes color polymorphism in the aposematic harlequin poison frog, Oophaga histrionica.

Whether hybridization can be a mechanism that drives phenotypic diversity is a widely debated topic in evolutionary biology. In poison frogs (Dendrobatidae), assortative mating has been invoked to explain how new color morphs persist despite the expected homogenizing effects of natural selection. Here, we tested the complementary hypothesis that new morphs arise through hybridization between different color morphs. Specifically, we (1) reconstructed the phylogenetic relationships among the studied populations of a dart-poison frog to provide an evolutionary framework, (2) tested whether microsatellite allele frequencies of one putative hybrid population of the polymorphic frog O. histrionica are intermediate between O. histrionica and O. lehmanni, and (3) conducted mate-choice experiments to test whether putatively intermediate females prefer homotypic males over males from the other two populations. Our findings are compatible with a hybrid origin for the new morph and emphasize the possibility of hybridization as a mechanism generating variation in polymorphic species. Moreover, because coloration in poison frogs is aposematic and should be heavily constrained, our findings suggest that hybridization can produce phenotypic novelty even in systems where phenotypes are subject to strong stabilizing selection.

Stream noise, hybridization, and uncoupled evolution of call traits in two lineages of poison frogs: Oophaga histrionica and Oophaga lehmanni.

According to the acoustic adaptation hypothesis, communication signals are evolutionary shaped in a way that minimizes its degradation and maximizes its contrast against the background noise. To compare the importance for call divergence of acoustic adaptation and hybridization, an evolutionary force allegedly promoting phenotypic variation, we compared the mate recognition signal of two species of poison frogs (Oophaga histrionica and O. lehmanni) at five localities: two (one per species) alongside noisy streams, two away from streams, and one interspecific hybrid. We recorded the calls of 47 males and characterized the microgeographic variation in their spectral and temporal features, measuring ambient noise level, body size, and body temperature as covariates. As predicted, frogs living in noisy habitats uttered high frequency calls and, in one species, were much smaller in size. These results support a previously unconsidered role of noise on streams as a selective force promoting an increase in call frequency and pleiotropic effects in body size. Regarding hybrid frogs, their calls overlapped in the signal space with the calls of one of the parental lineages. Our data support acoustic adaptation following two evolutionary routes but do not support the presumed role of hybridization in promoting phenotypic diversity.

A new species of Andean poison frog, Andinobates (Anura: Dendrobatidae), from the northwestern Andes of Colombia.

The poison frogs of the Colombian Andes, Pacific lowlands and Panama have been recently recognized as a new, monophyletic and well-supported genus: Andinobates. The species richness and distribution within Andinobates remain poorly understood due to the paucity of geographic, genetic and phenotypic data. Here we use a combination of molecular, bioacoustic and morphometric evidence to describe a new species of Andean poison frog: Andinobates cassidyhornae sp. nov. from the high elevation cloud forests of the Colombian Cordillera Occidental, in the northwestern Andes. The new species is associated to the bombetes group and characterized by a unique combination of ventral and dorsal color patterns. Data on 1119 bp from two mitochondrial markers allowed us to reject the null hypotheses that A. cassidyhornae sp. nov. is part of the phenotypically similar and geographically less distant species: A. opisthomelas, A. virolinensis or A. bombetes. The best available phylogenetic trees and the genetic distance to other Andinobates species further support this decision. Altogether, the advertisement call parameters unambiguously separated A. cassidyhornae sp. nov. calls from the calls of the three closest species. The new species adds to a poorly known and highly endangered genus of poison frogs that requires further studies and urgent conservation measures.