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Made available in DSpace on 2022-04-28T17:22:59Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-12-23 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET) Agencia Nacional de Promocion de la Investigacion, el Desarrollo Tecnologico y la Innovacion doctoral fellowship PICT We describe the hand and foot musculature of the fossorial Indian purple frog, Nasikabatrachus sahyadrensis, and compare it to other members of Sooglossoidea: the Seychellean sooglossid genera Sechellophryne and Sooglossus. Due to the key phylogenetic position of Sooglossoidea, we compare its members with the diversity of Anura and define 52 characters from the hand and foot musculature, among which 26 are novel hypotheses of homology. We found several synapomorphies for Sooglossus, Sooglossidae, Nasikabatrachidae and Sooglossoidea. Additionally, we (1) propose synapomorphies for diverse anuran clades at different taxonomic levels, (2) re-evaluate the identity of some conflicting plantar and palmar muscles in the context of Batrachia and (3) discuss putative adaptations to hind limb digging behaviour resulting from morphological convergences. The lack of a clear pattern of convergences among hind limb digging species suggests the occurrence of a phenomenon of many-to-one mapping from form to function. Univ Sao Paulo, Inst Biociencias, Dept Zool, BR-05508090 Sao Paulo, SP, Brazil Consejo Nacl Invest Cient & Tecn, Museo Argentino Ciencias Nat Bernardino Rivadavia, Div Herpetol, Angel Gallardo 470,C1405DJR, Buenos Aires, DF, Argentina Univ Delhi, Dept Environm Studies, Systemat Lab, Delhi 110007, India Univ Nacl Misiones, Fac Ciencias Exactas Quim & Nat, CONICET, Inst Biol Subtrop,Lab Genet Evolut Claudio J Bida, N3300LQF, Posadas, Misiones, Argentina Univ Estadual Paulista, Inst Biociencias, Dept Biodiversidade, BR-13506900 Rio Claro, SP, Brazil Univ Estadual Paulista, Inst Biociencias, Ctr Aquicultura, BR-13506900 Rio Claro, SP, Brazil Univ Buenos Aires, Fac Ciencias Exactas & Nat, Dept Biodiversidad & Biol Expt, C1428EGA, Buenos Aires, DF, Argentina Univ Sao Paulo, Museu Zool, Colecao Anfibios, BR-04263000 Sao Paulo, SP, Brazil Univ Estadual Paulista, Inst Biociencias, Dept Biodiversidade, BR-13506900 Rio Claro, SP, Brazil Univ Estadual Paulista, Inst Biociencias, Ctr Aquicultura, BR-13506900 Rio Claro, SP, Brazil FAPESP: 2012/10000-5 FAPESP: 2013/20423-3 FAPESP: 2015/11237-7 FAPESP: 2016/21401-1 FAPESP: 2018/15425-0 FAPESP: 2019/24979-2 PICT: 2015-813 PICT: 2015-820 PICT: 2018-3349 PICT: 2019-346 PICT: 2019-2519 PICT: 2019-2557

Several species of Cophomantini are known to have an enlarged prepollex, commonly modified as an osseous spine. We surveyed the osteology and myology of the prepollex and associated elements of 94 of the 190 species of Cophomantini, sampling all genera, except Nesorohyla. Two distinct prepollex morphologies were found: a blade-shaped and a spine-shaped morphology. We described the observed variation in 17 discrete characters to study their evolution in the most inclusive phylogenetic hypothesis for Cophomantini. Both morphologies evolved multiple times during the evolutionary history of this clade, but the origin of the spine-shaped distal prepollex in Boana and Bokermannohyla is ambiguous. The articulation of metacarpal II with the prepollex through a medial expansion of the metacarpal proximal epiphysis is a synapomorphy for Boana. The shape of the curve of the spine, and a large post-articular process of the distal prepollex, are synapomorphies for the Boana pulchella group, the latter being homoplastic in the Bokermannohyla martinsi group. Muscle character states associated with the spine-shaped prepollex are plesiomorphic for Cophomantini. We discuss evolution, function, behaviour and sexual dimorphism related to the prepollical elements. A bony spine is associated with fights between males, but forearm hypertrophy could be more related with habitat than with territorial combat.

Brachycephaloidea (composed of 1183 species) is the most diverse superfamily of amphibians. In recent years, molecular techniques utilizing genetic markers have significantly improved our understanding of the phylogeny of this superfamily. However, with the expansion of molecular techniques, phenotypic characters have received increasingly less attention. In an effort to highlight the contributions that phenotypic characters can make to understanding the phylogeny of Brachycephaloidea, we studied novel characters from pelvic and thigh musculature and digital discs on fingers. On this basis, we provide new phenotypic synapomorphies to recognize three clades previously recognized solely on the basis of DNA. The first two synapomorphies, related to the origins of the m. iliacus externus and m. tensor fasciae latae, diagnose Ceuthomantis and Phrynopus, respectively. The third synapomorphy, related to the relative size of the disc on finger I, diagnoses the Pristimantis conspicillatus species group, which is the largest species group within the species-rich genus Pristimantis. We conclude that phenotypic data are a valuable source of evidence in testing phylogenetic hypotheses of Brachycephaloidea and emphasize the need to reassess all phenotypic characters previously used in brachycephaloid taxonomy to delimit them objectively as transformation series and include them in total evidence analyses.

Since the systematics of Terrarana frogs was overhauled in 2008, five new genera have been named, including Tachiramantis from the Venezuelan Coastal Range and adjacent parts of the Cordillera Oriental of Colombia and the Sierra de Perijá along the Venezuela–Colombia border. The discovery of Tachiramantis raises questions about the relationships of several species of Pristimantis in the nearby Sierra Nevada de Santa Marta previously hypothesized to be closely related to species now referred to Tachiramantis. To test the monophyly of Tachiramantis and the relationships among its species, we generated DNA sequences for 42 individuals, and, given the variable placement of Tachiramantis in previous studies, analysed them with DNA sequences from GenBank representing 25 genera of terraranas. In total, the final matrix included DNA sequences from 414 terminals, which we analysed using tree-alignment under the parsimony optimality criterion. To identify morphological synapomorphies and diagnostic characters, we also examined cranial osteology and axial skeleton morphology. Our analyses corroborated both the placement of Tachiramantis far from Pristimantis in Craugastoridae and the monophyly of Tachiramantis. We also found that six species currently referred to Pristimantis, all endemic to the Sierra Nevada de Santa Marta, comprise the sister clade of Tachiramantis. This highly endemic clade is both well-supported by molecular data and diagnosed from Tachiramantis by seven morphological synapomorphies, leading us to recognize it as a new genus. http://zoobank.org/urn:lsid:zoobank.org:act:0036039F-F400-4CD4-A6AD-D3DD2B34BA4E

The methods of data exploration have become the centerpiece of phylogenetic inference, but without the scientific importance of those methods having been identified. We examine in some detail the procedures and justifications of Wheeler's sensitivity analysis and relative rate comparison (saturation analysis). In addition, we review methods designed to explore evidential decisiveness, clade stability, transformation series additivity, methodological concordance, sensitivity to prior probabilities (Bayesian analysis), skewness, computer-intensive tests, long-branch attraction, model assumptions (likelihood ratio test), sensitivity to amount of data, polymorphism, clade concordance index, character compatibility, partitioned analysis, spectral analysis, relative apparent synapomorphy analysis, and congruence with a "known" phylogeny. In our review, we consider a method to be scientific if it performs empirical tests, i.e., if it applies empirical data that could potentially refute the hypothesis of interest. Methods that do not perform tests, and therefore are not scientific, may nonetheless be heuristic in the scientific enterprise if they point to more weakly or ambiguously corroborated hypotheses, such propositions being more easily refuted than those that have been more severely tested and are more strongly corroborated. Based on common usage, data exploration in phylogenetics is accomplished by any method that performs sensitivity or quality analysis. Sensitivity analysis evaluates the responsiveness of results to variation or errors in parameter values and assumptions. Sensitivity analysis is generally interpreted as providing a measure of support, where conclusions that are insensitive (robust, stable) to perturbations are judged to be accurate, probable, or reliable. As an alternative to that verificationist concept, we define support objectively as the degree to which critical evidence refutes competing hypotheses. As such, degree of support is secondary to the scientific optimality criterion of maximizing explanatory power. Quality analyses purport to distinguish good, reliable, accurate data from bad, misleading, erroneous data, thereby assessing the ability of data to indicate the true phylogeny. Only the quality analysis of character compatibility can be judged scientific-and a weak test at that compared to character congruence. Methods judged to be heuristic include Bremer support, long-branch extraction, and safe taxonomic reduction, and we underscore the great heuristic potential of a posteriori analysis of patterns of transformations on the total-evidence cladogram. However, of the more than 20 kinds of data exploration methods evaluated, the vast majority is neither scientific nor heuristic. Given so little demonstrated cognitive worth, we conclude that undue emphasis has been placed on data exploration in phylogenetic inference, and we urge phylogeneticists to consider more carefully the relevance of the methods that they employ. [T]he cult of impressive technicalities or the cult of precision may get the better of us, and interfere with our search for clarity, simplicity, and truth [Popper, 1983, p. 60. Empirical papers chosen for publication are judged to be of interest to a broad systematics audience because they represent exemplary case studies involving some important contemporary issue or issues. These may be unusually thorough explorations of data, applications of new methodology, illustrations of fundamental principles, and/or investigations of interesting evolutionary questions. [Systematic Biology: Instructions for authors, 2002; italics added].

We examine recently proposed justifications of sensitivity analysis sensuWheeler (1995), here referred to as weighted-classes sensitivity analysis (WCSA). We refute Giribet's (2003a) claim that WCSA is the strictest possible test for a given phylogenetic hypothesis. Giribet's (2003a) classification of data exploration methods as evaluating “nodal stability” or “nodal support” is arbitrary, at odds with common usage and actually obscures the relationships between the methods he examined, all of which seek to assess the sensitivity of results to variation in analytical conditions. Stability, whether statistical or taxonomic, is not a goal of phylogenetic science. Statistical stability necessarily involves trial repetition, which is impossible in ideographic sciences like phylogenetics. Taxonomic stability can be nothing more than an unintended by-product of scientific inquiry, i.e., the repeated failure to refute a hypothesis. Schulmeister's (2003) “robust-choice” defense of WCSA does not succeed in placing non-arbitrary bounds on parameters, and her interpretation of this approach as simultaneously verificationist and falsificationist is logically inconsistent. WCSA is neither scientific nor heuristic and therefore does not contribute to the advancement of objective knowledge claims. © The Willi Hennig Society 2005.

In maximum likelihood (ML), the support for a clade can be calculated directly as the likelihood ratio (LR) or log-likelihood difference (S, LLD) of the best trees with and without the clade of interest. However, bootstrap (BS) clade frequencies are more pervasive in ML phylogenetics and are almost universally interpreted as measuring support. In addition to theoretical arguments against that interpretation, BS has several undesirable attributes for a support measure. For example, it does not vary in proportion to optimality or identify clades that are rejected by the evidence and can be overestimated due to missing data. Nevertheless, if BS is a reliable predictor of S, then it might be an efficient indirect method of measuring support-an attractive possibility, given the speed of many BS implementations. To assess the relationship between S and BS, we analyzed 106 empirical datasets retrieved from TreeBASE. Also, to evaluate the degree to which S and BS are affected by the number of replicates during suboptimal tree searches for S and pseudoreplicates during BS estimation, we randomly selected 5 of the 106 datasets and analyzed them using variable numbers of replicates and pseudoreplicates, respectively. The correlation between S and BS was extremely weak in the datasets we analyzed. Increasing the number of replicates during tree search decreased the estimated values of S for most clades, but the magnitude of change was small. In contrast, although increasing pseudoreplicates affected BS values for only approximately 40% of clades, values both increased and decreased, and they did so at much greater magnitudes. Increasing replicates/pseudoreplicates affected the rank order of clades in each tree for both S and BS. Our findings show decisively that BS is not an efficient indirect method of measuring support and suggest that even quite superficial searches to calculate S provide better estimates of support.

The hands of adult males of many dendrobatid poison frogs and their relatives possess swelling formed by glandular tissue hypothesized to secrete courtship pheromones delivered to the female during cephalic amplexus. Variation in the occurrence and external morphology of the swelling of finger IV has provided important evidence for dendrobatoid systematics for decades, but its underlying structure has not been investigated. We undertook a detailed comparative analysis of the integument of the hand, including both external morphology and histology, of 36 species representing the diversity of dendrobatoid frogs and several close relatives. The swelling is caused by four densely packed, hypertrophic, morpho-histochemical types of specialized mucous glands (SMGs). We observed type I SMGs on fingers II-V and the wrist, including areas that are not swollen, types II and IV exclusively on finger IV, and type III on finger IV and the wrist. Type I SMGs occur either in isolation or together with types II, III, or IV; types II, III, and IV never occur together or without type I. We delimited 15 characters to account for the variation in external morphology and the occurrence of SMGs. Our data suggest that type I SMGs are a new synapomorphy for Dendrobatoidea and that type II SMGs originated in either the most recent common ancestor (MRCA) of Dendrobatidae or independently in the MRCAs of Aromobatidae and Colostethinae, respectively, while types III and IV are restricted to Anomaloglossus. The discovery of these SMGs adds a new dimension to studies of poison frog reproductive biology, which have investigated acoustic, visual, and tactile cues in courtship, mating, and parental care across the diversity of Dendrobatoidea for decades but have almost entirely overlooked the possible role of chemical cues.

As is typical of chemically defended animals, poison frogs present high variability in their alkaloid-based defenses. Previous studies have shown that geographically separated color morphs of Oophaga and Dendrobates species differ in both alkaloid composition and arthropod palatability. Here, we tested the generality of that finding by studying the alkaloid composition and palatability of geographically separated blue and orange morphs of the splash-backed poison frog, Adelphobates galactonotus. We identified and quantified the alkaloid composition of each individual frog using gas chromatography–mass spectrometry and evaluated the palatability of individual secretions to arthropods conducting feeding trials with Drosophila melanogaster. Despite their conspicuous differences in color and separation on opposite sides of a large aquatic barrier, the two morphs did not differ in alkaloid composition or palatability. This result shows that both color morphs are equally chemically protected and suggests that the color variation is not driven by predator selection.

Made available in DSpace on 2022-04-28T19:40:20Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-08-01 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) The evolutionary success of anurans can be partially explained by the occurrence of free-living larvae. Tadpoles occupy several distict habitats, including the terrestrial environment. Semiterrestriality appears to have evolved seven times in anurans, and tadpoles of distantly related lineages have converged in a set of phenotypic characters, such as a depressed body, ventral mouth, massive, well-keratinized and laterally compressed jaw sheaths, low fins, and well-developed hind limbs. The semiterrestrial tadpoles of the South American family Cycloramphidae remain poorly studied. In this work, we perform a comparative analysis of the external and internal morphology of these larvae, we comment on the systematic and evolutionary implications for the family, and finally, we discuss the convergent evolution of semiterrestrial tadpoles in anurans. We studied the external, buccopharyngeal, and musculoskeletal morphology of semiterrestrial tadpoles of 14 species of Cycloramphidae. These tadpoles are highly modified and present several character-states associated with semiterrestrial life. Most of them are unique and restricted to the family, such as the novel configuration of the muscles subarcualis rectus I, rectus abdominis, and levator arcuum branchialium III. We propose 13 new synapomorphies for Cycloramphidae and one for Thoropa. The presence of similar, homoplastic, character-states in all semiterrestrial tadpoles of unrelated phylogenetic lineages seems to suggest that these character-states are adaptations for semiterrestriality. Departamento de Zoologia Instituto de Biociências Universidade de São Paulo Departamento de Zoologia Universidade Federal do Paraná Unidad Ejecutora Lillo (CONICET – FML) San Miguel de Tucumán Departamento de Biodiversidade and CAUNESP Instituto de Biociências Universidade Estadual Paulista Departamento de Biologia Animal Universidade Federal Rural do Rio de Janeiro Departamento de Zoologia Laboratório de Biossistemática de Anfíbios Universidade Federal do Estado do Rio de Janeiro Departamento de Biodiversidade and CAUNESP Instituto de Biociências Universidade Estadual Paulista FAPESP: 2012/10000-5 FAPESP: 2013/20420-4 FAPESP: 2013/50741-7 FAPESP: 2015/11239-0 FAPESP: 2018/15425-0 CNPq: 306623/2018-8 CNPq: 306823/2017-9 CNPq: 306963/2018-3 CAPES: 88887.364687/2019-00

True toads of the genus Rhinella are among the most common and diverse group of Neotropical anurans. These toads are widely distributed throughout South America, inhabiting a great diversity of environments and ecoregions. Currently, however, the genus is defined solely on the basis of molecular characters, and it lacks a proper diagnosis. Although some phenetic species groups have traditionally been recognized within Rhinella, the monophyly of some of them have been rejected in previous phylogenetic analyses, and many species remain unassigned to these poorly defined groups. Additionally, the identity and taxonomy of several species are problematic and hinder the specific recognition and description of undescribed taxa. In this work, we first perform phylogenetic analyses of separate mitochondrial and nuclear datasets to test the possible occurrence of hybridiza-tion and/or genetic introgression in the genus. The comparative analysis of both datasets revealed unidirectional mitochondrial introgressions of an unknown parental species into R . horribilis (“ghost introgression”) and of R . dorbignyi into R . bernardoi; therefore, the mitochondrial and nuclear data-sets of these species were considered separately in subsequent analyses. We performed total-evidence phylogenetic analyses that included revised molecular (four mitochondrial and five nuclear genes) and phenotypic (90 characters) datasets for 83 nominal species of Rhinella, plus several undescribed and problematic species and multiple outgroups. Results demonstrate that Rhinella was nonmono-phyletic due to the position of R . ceratophrys, which was recovered as the sister taxon of Rhaebo nasicus with strong support. Among our outgroups, the strongly supported Anaxyrus + Incilius is the sister clade of all other species of Rhinella. Once R . ceratophrys is excluded, the genus Rhinellais monophyletic, well supported, and composed of two major clades. One of these is moderately supported and includes species of the former R . spinulosa Group (including R . gallardoi); the mono-phyletic R . granulosa, R . crucifer, and R . marina Groups; and a clade composed of the mitochondrial sequences of R . horribilis. The other major clade is strongly supported and composed of all the spe-cies from the non-monophyletic R . veraguensis and R . margaritifera Groups, the former R . acrolophaGroup, and R . sternosignata. Consistent with these results, we define eight species groups of Rhinella that are mostly diagnosed by phenotypic synapomorphies in addition to a combination of morpho-logical character states. Rhinella sternosignata is the only species that remains unassigned to any group. We also synonymize nine species, treat three former subspecies as full species, and suggest that 15 lineages represent putative undescribed species. Lastly, we discuss the apparently frequent occurrence of hybridization, deep mitochondrial divergence, and “ghost introgression”; the incomplete phenotypic evidence (including putative character systems that could be used for future phy-logenetic analyses); and the validity of the known fossil record of Rhinella as a source of calibration points for divergence dating analyses.

International socioeconomic relationships form the background that underlies the history of invasive species. Species with economic value, such as the North American bullfrog (Lithobates catesbeianus), are more likely to become internationally distributed and to be subsequently introduced to non-native areas and, consequently, become more difficult to control. Using population genetics methods, we investigated the invasion pathways, the connectivity among clusters in different countries and the native population of origin of globally introduced bullfrog populations. Throughout the analysis of seven microsatellite nuclear loci, one fragment of the mitochondrial cytochrome b locus, and historical information, four main lineages were identified and analyzed along with previous findings. This species’ capability to colonize several countries from few starting lineages highlights the necessity to control new propagule pressure to ensure successful management programs, as high inbreeding and bottleneck effect seem not to diminish the invasive success of this species. There is a consensus between markers that most areas of South America belong to the same genetic population while populations in Asia have a more complex history of introduction.

Este artigo apresenta os resultados da análise dos vasilhames com apliques de anuros das cerâmicas arqueológicas oriundas de coletas sistemáticas nas estearias maranhenses associando-os às espécies biológicas. Parte-se, portanto, de um estudo interdisciplinar que busca atentar para a importância deste tipo de abordagem ainda pouco utilizada pelos arqueólogos brasileiros, sobretudo na Amazônia, cuja imagética arqueológica associada a sapos e rãs é recorrente no material arqueológico desta região. Apresentam-se os apliques de anuros, sua análise tecnológica, as formas dos vasilhames e a identificação das espécies, fomentando a interpretação dos resultados com enfoque na relação entre cultura material e biologia.

The Neotropical hylid genus Sphaenorhynchus includes 15 species of small, greenish treefrogs widespread in the Amazon and Orinoco basins, and in the Atlantic Forest of Brazil. Although some studies have addressed the phylogenetic relationships of the genus with other hylids using a few exemplar species, its internal relationships remain poorly understood. In order to test its monophyly and the relationships among its species, we performed a total evidence phylogenetic analysis of sequences of three mitochondrial and three nuclear genes, and 193 phenotypic characters from all species of Sphaenorhynchus. Our results support the monophyly of Sphaenorhynchus with molecular and phenotypic evidence, with S. pauloalvini as the earliest diverging taxon, followed by S. carneus, as the sister taxon of all remaining species of the genus. We recognize three species groups in Sphaenorhynchus (the S. lacteus, S. planicola and S. platycephalus groups), to facilitate its taxonomic study; only three species (S. carneus, S. pauloalvini and S. prasinus) remain unassigned to any group. Sequence data were not available for only two species (S. bromelicola and S. palustris) for which we scored phenotypic data; wildcard behaviour was detected only in S. bromelicola nested inside the S. platycephalus group. On the basis of the resulting phylogenetic hypothesis, we discuss the evolution of oviposition site and a number of phenotypic characters that could be associated with heterochronic events in the evolutionary history of this group. Fil: de Araujo Vieira, Katyuscia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; Argentina Fil: Blotto Acuña, Boris Leonardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; Argentina. Universidade de Sao Paulo; Brasil Fil: Confalonieri, Ulisses. Universidade Federal do Rio de Janeiro; Brasil Fil: Baptista Haddad, Célio Fernando. Universidade Estadual Paulista Julio de Mesquita Filho; Brasil Fil: Faivovich, Julián. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Biodiversidad y Biología Experimental; Argentina Fil: Grant, Taran. Universidade de Sao Paulo; Brasil

We describe the buccopharyngeal morphology of the dendrobatid poison frog Ameerega flavopicta—the first such description for the genus—and discuss diagnostic characters and variation of bu...

The trans-Andean genus Epipedobates comprises seven species, of which tadpoles have been described for five. Herein, we describe the tadpole of Epipedobates darwinwallacei and compare it to free-swimming tadpoles of E. anthonyi, E. boulengeri, E. espinosai, E. machalilla, E. narinensis, and E. tricolor. Furthermore, we suggest as putative synapomorphies for the genus Epipedobates the following larval character-states: (i) shelf on the upper jaw sheath, and (ii) subcutaneous melanophores distributed in two transverse bands in the peribranchial area. Additionally, the presence of white spots on the anterolateral and ventrolateral surfaces of the body is possibly synapomorphic but requires further study.

We applied a novel strategy to infer sequence circularity and complete assembly of four mitochondrial genomes (mitogenomes) of the frog families Bufonidae (Melanophryniscus moreirae), Dendrobatidae (Hyloxalus subpunctatus and Phyllobates terribilis), and Scaphiopodidae (Scaphiopus holbrookii). These are the first complete mitogenomes of these four genera and Scaphiopodidae. We assembled mitogenomes from short genomic sequence reads using a baiting and iterative mapping strategy followed by a new ad hoc mapping strategy developed to test for assembly circularization. To assess the quality of the inferred circularization, we used Bowtie2 alignment scores and a new per‐position sequence coverage value (which we named “connectivity”). Permutation tests with 400 iterations per specimen and 1% or 5% chance of mutation at the ends of the putative circular sequences showed that the proposed method is highly sensitive, with a single nucleotide insertion or deletion being sufficient for circularity to be rejected. False positives comprised only 2% of all observations and possessed significantly lower alignment scores. The size, gene content, and gene arrangement of each mitogenome differed among the species but matched the expectations for their clades. We argue that basic studies on circular sequences can benefit from the results and bioinformatics procedures introduced here, especially when closely related references are lacking.

Amezquita et al. (2017) recently concluded that species of the Allobates femoralis group are toxic to mice at levels equivalent to syntopic alkaloid-containing poison frogs, which they attributed to the presence of alkaloids in skin secretions. However, the chemical composition of skin secretions was not analyzed, and here we present additional data supporting the absence of alkaloids in skin secretions of the Allobates femoralis group. Instead, we suggest the observed toxicity was caused by the anesthetic benzocaine, which was applied to the buccal cavity to euthanize frogs prior to skin removal. We show that orally administered benzocaine is rapidly incorporated into the skin of species that sequester and do not sequester alkaloids, which casts doubt on the conclusion that Allobates femoralis group skin secretions are toxic and makes the results of experiments with alkaloid-containing species of Adelphobates and Ameerega uninterpretable. To prevent experimental errors and misinterpretations in studies of amphibian chemical defense, we encourage researchers to test the chemical composition of samples prior to experimentation, include all necessary controls to detect false positives, conduct small pilot studies for new methods, and consider the limitations of particular methods and their ability to address the intended research questions.

We describe a striking new species of the genus Sachatamia from the eastern slope of Colombia's Central Andes. The new species differs from the most closely related species (i.e., Sachatamia albomaculata and S. punctulata) by its green dorsal coloration in life with yellow and blue dots, and unique semicirclular, white blotch in the dorsal portion of the iris. With this new species, we increase the currently recognized species in the genus to five. Mitochondrial DNA sequences corroborate both the phylogenetic position of the new species within Sachatamia and its status as a new species. In addition, in light of our results some taxonomic implications are briefly discussed.

Centrolenidae is a monophyletic group of Neotropical tree frogs. Centrolenid tadpoles usually lack pigmentation on their bodies, presenting reddish coloration in life, and are fossorial. Several phenotypic characters have been associated with fossoriality, but data on larval morphology is scarce. Herein, we describe the buccopharyngeal morphology of two Vitreorana tadpoles and identify putative synapomorphies for the family, including 1) the presence of vacuities on the buccal roof arena; 2) the nares being oriented longitudinally; 3) the presence of a conical median ridge at the end of the postnarial arena; and 4) the posterior–most pair of postnarial papilla being aligned in row with the median ridge.

Although studies of anuran hand and foot musculature began in the first half of the 19th century, all studies to date have been taxonomically or anatomically restricted in scope, and none has considered the diversity of autopodial myology in Anura as a whole. As a model for future comparisons, we thoroughly describe the hand and foot musculature of an arboreal species (the hylid Triprion petasatus), define the layers in which these muscles are arranged, and attribute presumed functions. On the basis of our myological analysis of 155 species representing 46 of the 54 currently recognized families and main clades of anurans, we describe 20 characters related to hand and foot muscles. Optimization of these characters on the most recent and inclusive phylogenetic hypothesis of Anura results in synapomorphies for several major clades (Bombinatoridae, Alytidae, Xenoanura + Acosmanura, Xenoanura, Pipidae, Acosmanura, Anomocoela, Scaphiopodidae, Pelodytidae + Pelobatidae + Megophryidae, Megophryidae, Neobatrachia, Heleophrynidae, Sooglossidae, Laurentobatrachia, Calyptocephalellidae, Myobatrachoidea, and Nobleobatrachia), including new, nonhomoplastic synapomorphies for clades previously supported only by molecular evidence and a few conflicting phenotypic characters (e.g., Acosmanura, Anomocoela, Neobatrachia). Additionally, we (1) address controversies regarding the homology of anuran and caudate muscles in the context of putative synapomorphies for Ascaphidae + Leiopelmatidae and its sister clade Lalagobatrachia; (2) evaluate a recently proposed terminology for anuran hand and foot musculature; (3) discuss the identities of several hand and foot muscles with problematic homologies; (4) establish a unified terminology for anuran hand and foot muscles, including a list of synonyms for all names employed in the literature; and (5) propose hypotheses for the origin of several myological novelties (neomorphs).

Made available in DSpace on 2020-12-12T02:22:57Z (GMT). No. of bitstreams: 0 Previous issue date: 2020-01-01 The relationships of the hyline tribe Dendropsophini remain poorly studied, with most published analyses dealing with few of the species groups of Dendropsophus. In order to test the monophyly of Dendropsophini, its genera, and the species groups currently recognized in Dendropsophus, we performed a total evidence phylogenetic analysis. The molecular dataset included sequences of three mitochondrial and five nuclear genes from 210 terminals, including 12 outgroup species, the two species of Xenohyla, and 93 of the 108 recognized species of Dendropsophus. The phenomic dataset includes 46 terminals, one per species (34 Dendropsophus, one Xenohyla, and 11 outgroup species). Our results corroborate the monophyly of Dendropsophini and the reciprocal monophyly of Dendropsophus and Xenohyla. Some species groups of Dendropsophus are paraphyletic (the D. microcephalus, D. minimus, and D. parviceps groups, and the D. rubicundulus clade). On the basis of our results, we recognize nine species groups; for three of them (D. leucophyllatus, D. microcephalus, and D. parviceps groups) we recognize some nominal clades to highlight specific morphology or relationships and facilitate species taxonomy. We further discuss the evolution of oviposition site selection, where our results show multiple instances of independent evolution of terrestrial egg clutches during the evolutionary history of Dendropsophus. Tropical Herpetology Laboratory Departamento de Ciências Biológicas Universidade Estadual de Santa Cruz, Rodovia Jorge Amado, km 16 Laboratório de Anfíbios Departamento de Zoologia Instituto de Biociências Universidade de São Paulo División Herpetología Museo Argentino de Ciencias Naturales “Bernardino Rivadavia”–CONICET, Angel Gallardo 470 Departamento de Biodiversidad y Biología Experimental Facultad de Ciencias Exactas y Naturales Universidad de Buenos Aires Grupo Herpetológico de Antioquia Instituto de Biología Universidad de Antioquia Departamento de Biodiversidade and Centro de Aquicultura Instituto de Biociências Universidade Estadual Paulista (UNESP), Av. 24A 1515 Laboratório de Ecologia da Paisagem - Superintendência de Conservação WWF-Brasil, Entre Quadra SHIS EQL 6/8 Conjunto E, Setor de Habitações Individuais Sul Department of Biology The University of Texas at Arlington Department of Bioinformatics and Genomics University of North Carolina at Charlotte, 9201 University City Blvd. Division of Invertebrate Zoology American Museum of Natural History, Central Park West Doc Frog Expeditions Laboratório de Vertebrados Instituto de Ciências Biológicas Universidade Federal do Rio Grande, Av. Itália, km 8 Department of Zoology National Museum, Cirkusová 1740, 193 00 Prague 9 Departamento de Ciências Biológicas Universidade Estadual do Sudoeste da Bahia, Av. José Moreira Sobrinho Departamento de Ecologia e Biologia Evolutiva Universidade Federal de São Paulo, Av. Professor Artur Riedel, 275, Jardim Eldorado Coordenação de Zoologia Museu Paraense Emílio Goeldi, Avenida Perimetral 1901, Terra Firme Instituto de Ciências Biológicas Universidade Federal do Pará, R. Augusto Corrêa, 1, Guamá Instituto de Biología Subtropical (IBS) CONICET-UNaM, Bertoni 85 Departamento de Biodiversidade and Centro de Aquicultura Instituto de Biociências Universidade Estadual Paulista (UNESP), Av. 24A 1515

Made available in DSpace on 2020-12-10T19:54:02Z (GMT). No. of bitstreams: 0 Previous issue date: 2020-03-27 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Rede Baiana de Pesquisa sobre Anfibios (RBPA) Fundacao O Boticario de Protecao a Natureza Fundacao de Amparo a Pesquisa da Bahia (FAPESB) Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Mohamed bin Zayed Species Conservation Fund Fundação de Amparo à Pesquisa do Estado do Rio de Janeiro (FAPERJ) Smithsonian Institution (USA) Agencia Nacional de Promocion Cientifica y Tecnologica (ANPCyT) The South American and West Indian Casque-headed Treefrogs (Hylidae: Hylinae: Lophyohylini) include 85 species. These are notably diverse in morphology (e.g. disparate levels of cranial hyperossification) and life history (e.g. different reproductive modes, chemical defences), have a wide distribution, and occupy habitats from the tropical rainforests to semiarid scrubland. In this paper, we present a phylogenetic analysis of this hylid tribe based on sequence fragments of up to five mitochondrial (12S, 16S, ND1, COI, Cytb) and six nuclear genes (POMC, RAG-1, RHOD, SIAH, TNS3, TYR). We included most of its species (> 96%), in addition to a number of new species. Our results indicate: (i) the paraphyly of Trachycephalus with respect to Aparasphenodon venezolanus; (ii) the nonmonophyly of Aparasphenodon, with Argenteohyla siemersi, Corythomantis galeata and Nyctimantis rugiceps nested within it, and Ap. venezolanus nested within Trachycephalus; (iii) the polyphyly of Corythomantis; (iv) the nonmonophyly of the recognized species groups of Phyllodytes; and (v) a pervasive low support for the deep relationships among the major clades of Lophyohylini, including C. greeningi and the monotypic genera Itapotihyla and Phytotriades. To remedy the nonmonophyly of Aparasphenodon, Corythomantis, and Trachycephalus, we redefined Nyctimantis to include Aparasphenodon (with the exception of Ap. venezolanus, which we transferred to Trachycephalus), Argenteohyla, and C. galeata. Additionally, our results indicate the need for taxonomic work in the following clades: (i) Trachycephalus dibernardoi and Tr. imitatrix; (ii) Tr. atlas, Tr. mambaiensis and Tr. nigromaculatus; and (iii) Phyllodytes. On the basis of our phylogenetic results, we analyzed the evolution of skull hyperossification and reproductive biology, with emphasis on the multiple independent origins of phytotelm breeding, in the context of Anura. We also analyzed the inter-related aspects of chemical defences, venom delivery, phragmotic behaviour, co-ossification, and prevention of evaporative water loss. Univ Estadual Paulista, Inst Biociencias, Dept Biodiversidade, Av 24A 1515, BR-13506900 Rio Claro, SP, Brazil Univ Estadual Paulista, Inst Biociencias, Ctr Aquicultura, Av 24A 1515, BR-13506900 Rio Claro, SP, Brazil Univ Sao Paulo, Inst Biociencias, Dept Zool, BR-05508090 Sao Paulo, SP, Brazil Univ Fed Rio de Janeiro, Museu Nacl, Dept Vertebrados, Setor Herpetol, BR-20940040 Rio De Janeiro, RJ, Brazil Univ Estadual Santa Cruz, Dept Ciencias Biol, Trop Herpetol Lab, Rodovia Jorge Amado,Km 16, BR-45662900 Ilheus, BA, Brazil Univ Brasilia, Dept Engn Florestal, Lab Fauna & Unidades Conservacao, BR-70910900 Brasilia, DF, Brazil Univ Fed Vicosa, Dept Biol Anim, Museu Zool Joao Moojen, BR-36570900 Vicosa, MG, Brazil Univ West Indies, Zool Museum, Dept Life Sci, St Augustine, Trinidad Tobago Pontificia Univ Catolica Rio Grande do Sul, Lab Sistemat Vertebrados, Av Ipiranga 6681,Predio 40,Sala 110, BR-90619900 Porto Alegre, RS, Brazil Consejo Nacl Invest Cient & Tecn, UNaM, Inst Biol Subtrop, Lab Genet Evolut Claudio Juan Bidau, Felix Azara 1552,CPA N3300LQF Posadas, Misiones, Argentina Univ Estadual Paulista, Inst Biociencias, Lab Herpetol, Campus Litoral Paulista, BR-11330900 Sao Vicente, SP, Brazil Univ Nacl Nordeste, CONICET, Fac Ciencias Exactas & Nat & Agrimensura, Lab Herpetol,Dept Biol, Av Libertad 5470, RA-3400 Corrientes, Argentina Consejo Nacl Invest Cient & Tecn, Fdn Miguel Lillo, Unidad Ejecutora Lillo, Miguel Lillo 251, RA-4000 San Miguel De Tucuman, Tucuman, Argentina Univ Koblenz Landau, Inst Integrated Sci, Dept Biol, Univ Str 1, D-56070 Koblenz, Germany Univ Fed Rural Rio De Janeiro, Inst Biol, Dept Biol Anim, Caixa Postal 74524, BR-23851970 Seropedica, RJ, Brazil Consejo Nacl Invest Cient & Tecn, Museo Argentino Ciencias Nat Bernardino Rivadavia, Div Herpetol, Angel Gallardo 470,C1405DJR, Buenos Aires, DF, Argentina Univ Buenos Aires, Fac Ciencias Exactas & Nat, Dept Biodiversidad & Biol Expt, Buenos Aires, DF, Argentina Univ Estadual Paulista, Inst Biociencias, Dept Biodiversidade, Av 24A 1515, BR-13506900 Rio Claro, SP, Brazil Univ Estadual Paulista, Inst Biociencias, Ctr Aquicultura, Av 24A 1515, BR-13506900 Rio Claro, SP, Brazil Univ Estadual Paulista, Inst Biociencias, Lab Herpetol, Campus Litoral Paulista, BR-11330900 Sao Vicente, SP, Brazil FAPESP: 2013/20423-3 FAPESP: 2017/26162-8 FAPESP: 2003/10335-8 FAPESP: 2011/50146-6 FAPESP: 2018/15425-0 FAPESP: 2012/10000-5 FAPESP: 2013/50741-7 FAPESP: 2007/57067-9 FAPESP: 2012/12500-5 CNPq: 167387/20170 CNPq: 155198/2018-1 CNPq: 476789/2009-5 CNPq: 306823/2017-9 CNPq: 140412/2008-5 CNPq: 150377/2012-6 CNPq: 150122/2014-4 Fundacao O Boticario de Protecao a Natureza: 0991_20132 Fundacao de Amparo a Pesquisa da Bahia (FAPESB): 8951/2014 CAPES: 001 CAPES: 88881.133927/2016-01 CNPq: 140716/2016-5 FAPESP: 2014/50342-8 Agencia Nacional de Promocion Cientifica y Tecnologica (ANPCyT): PICT 2013-404 Agencia Nacional de Promocion Cientifica y Tecnologica (ANPCyT): 2015-820

The amount of short wavelength (UV, violet and blue) light that reaches the retina depends on the transmittance properties of the ocular media, especially the lens, and varies greatly across species in all vertebrate groups studied previously. We measured the lens transmittance in 32 anuran amphibians with different habits, geographic distributions, and phylogenetic positions and used them together with eye size and pupil shape to evaluate the relationship with diel activity pattern, elevation and latitude. We found an unusually high lens UV transmittance in the most basal species, and a range that extends into the visible spectrum for the rest of the sample, with lenses even absorbing violet light in some diurnal species. However, other diurnal frogs had lenses that transmit UV light like the nocturnal species. This unclear pattern in the segregation of ocular media transmittance and diel activity is shared with other vertebrates and is consistent with the absence of significant correlations in our statistical analyses. Although we did not detect a significant phylogenetic effect, closely related species tend to have similar transmittances, irrespective of whether they share the same diel pattern or not, suggesting that ocular media transmittance properties might be related to phylogeny.

Enclosed are the figures, tables, and supplementary digital material of the manuscript entitled "Evidence of Absence Treated as Absence of Evidence: The Effects of Variation in the Number and Distribution of Gaps Treated as Missing Data on the Results of Standard Maximum Likelihood Analysis." See the README files (in Markdown and PDF format) for additional details., Funding was provided by the Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP 2012/10000-5, 2013/09598-8, 2015/18654-2).

Ikakogi is a behaviorally and morphologically intriguing genus of glassfrog. Using tadpole morphology, vocalizations, and DNA, a new species is described from the Sierra Nevada de Santa Marta (SNSM), an isolated mountain range in northern Colombia. The new taxon is the second known species of the genus Ikakogi and is morphologically identical to I. tayrona (except for some larval characters) but differs by its genetic distance (14.8% in mitochondrial encoded cytochrome b MT-CYB; ca. 371 bp) and by the dominant frequency of its advertisement call (2928-3273 Hz in contrast to 2650-2870 Hz in I. tayrona). They also differ in the number of lateral buccal floor papillae, and the position of the buccal roof arena papillae. Additionally, the new species is differentiated from all other species of Centrolenidae by the following traits: tympanum visible, vomerine teeth absent, humeral spines present in adult males, bones in life white with pale green in epiphyses, minute punctuations present on green skin dorsum, and flanks with lateral row of small, enameled dots that extend from below eye to just posterior to arm insertion. We describe the external and internal larval morphology of the new species and we redescribe the larval morphology of Ikakogi tayrona on the basis of field collected specimens representing several stages of development from early to late metamorphosis. We discuss the relevance of larval morphology for the taxonomy and systematics of Ikakogi and other centrolenid genera. Finally, we document intraspecific larval variation in meristic characters and ontogenetic changes in eye size, coloration, and labial tooth-rows formulas, and compare tadpoles of related species. Ikakogi tayrona has been proposed as the sister taxon of all other Centrolenidae; our observations and new species description offers insights about the ancestral character-states of adults, egg clutches, and larval features in this lineage of frogs.

The transmittance properties of the cornea, lens and humours of vertebrates determine how much light across the visible spectrum reaches the retina, influencing sensitivity to visual stimuli. Amphibians are the only vertebrate class in which the light transmittance of these ocular media has not been thoroughly characterised, preventing large-scale comparative studies and precise quantification of visual stimuli in physiological and behavioural experiments. We measured the ocular media transmittance in some commonly used species of amphibians (the bufonids

Background Lizards are excellent models to study the adaptations of the visual system to different scenarios, and surface-dwelling representatives have been relatively well studied. In contrast, very little is known about the functional anatomy of the eyes of fossorial lineages, and properties such as the light transmission by the ocular media have never been characterised in any fossorial species. Some lizards in the family Gymnophthalmidae endemic to the sand dunes of North Eastern Brazil have evolved sand-burrowing habits and nocturnal activity. Lizards in the sister group to Gymnophthalmidae, the family Teiidae, have decidedly diurnal and epigeal lifestyles, yet they are equally poorly known in terms of visual systems. We focussed on the eye anatomy, photoreceptor morphology and light transmittance properties of the ocular media and oil droplets in the gymnophthalmid Calyptommatus nicterus and the teiid Ameivula ocellifera. Results The general organisation of the eyes of the fossorial nocturnal C. nicterus and the epigeal diurnal A. ocellifera is remarkably similar. The lenses are highly transmissive to light well into the ultraviolet part of the spectrum. The photoreceptors have the typical cone morphology, with narrow short outer segments and oil droplets. The main difference between the two species is that C. nicterus has only colourless oil droplets, whereas A. ocellifera has colourless as well as green-yellow and pale-orange droplets. Conclusions Our results challenge the assumption that fossorial lizards undergo loss of visual function, a claim that is usually guided by the reduced size and external morphology of their eyes. In the case of C. nicterus, the visual system is well suited for vision in bright light and shows specialisations that improve sensitivity in dim light, suggesting that they might perform some visually-guided behaviour above the surface at the beginning or the end of their daily activity period, when light levels are relatively high in their open dunes habitat. This work highlights how studies on the functional anatomy of sensory systems can provide insights into the habits of secretive species.

Ambient mass spectrometry is useful for analyzing compounds that would be affected by other chemical procedures. Poison frogs are known to sequester alkaloids from their diet, but the sequestration pathway is unknown. Here, we describe methods for whole-body cryosectioning of frogs and use desorption electrospray ionization mass spectrometry imaging (DESI-MSI) to map the orally administered alkaloid histrionicotoxin 235A in a whole-body section of the poison frog Dendrobates tinctorius. Our results show that whole-body cryosectioning coupled with histochemical staining and DESI-MSI is an effective technique to visualize alkaloid distribution and help elucidate the mechanisms involved in alkaloid sequestration in poison frogs.

The transmittance properties of the cornea, lens and humours of vertebrates determine how much light across the visible spectrum reaches the retina, influencing sensitivity to visual stimuli. Amphibians are the only vertebrate class in which the light transmittance of these ocular media have not been thoroughly characterised, preventing large-scale comparative studies and precise quantification of visual stimuli in physiological and behavioural experiments. We measured the ocular media transmittance in some commonly used species of amphibians (the bufonids Bufo bufo and Rhinella ornata and the ranids Lithobates catesbeianus and Rana temporaria) and found low transmittance of short wavelength light, with ranids having less transmissive ocular media than bufonids. Our analyses also show that these transmittance properties have a considerable impact on photoreceptor spectral sensitivity, highlighting the need to incorporate this type of measurements into the design of stimuli for experiments on visual function.

To address the rapid and massive loss of biodiversity worldwide, scientific research must inform agile decision-making. The political leaders of Brazil, the country with the planet's greatest biological wealth ([ 1 ][1]), continue to undermine this goal. In 2001, citing the laudable objective of

Sphaenorhynchus platycephalus was briefly described on the basis of a single specimen, with only "S-Amerika" as its locality. Although it has been regarded as a distinct species, compelling evidence is lacking. A comparison of all currently described species of Sphaenorhynchus, including type specimens of several species, allowed us to provide morphological evidence that S. platycephalus and S. orophilus are conspecific, with S. orophilus being a junior synonym of S. platycephalus. Fil: de Araujo Vieira, Katyuscia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales “Bernardino Rivadavia”; Argentina Fil: Caramaschi, Ulisses. Universidade Federal do Rio de Janeiro; Brasil Fil: Grillitsch, Heinz. Natural History Museum Vienna; Austria Fil: Grant, Taran. Universidade de Sao Paulo; Brasil Fil: Faivovich, Julián. Universidad de Buenos Aires; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales “Bernardino Rivadavia”; Argentina

We evaluate the monophyly and phylogenetic relationships of the Pristimantis leptolophus species group and describe its external morphology, osteology, and some myological characteristics. We also compare the P . leptolophus species group to other related species groups. The P . leptolophus group is not monophyletic due to the inclusion of P. acatallelus , formerly believed to be part of the P. devillei group. The revised P. leptolophus group is composed of nine named species and six unnamed species. Based on our results, we recognize a new species group, the P . boulengeri species group, composed of eight species, many of which were previously assigned to the P. lacrimosus species group.

We studied the foot musculature of the fossorial family Odontophrynidae (composed of the genera Macrogenioglottus, Odontophrynus, and Proceratophrys) plus several outgroup taxa from Hyloidea and other burrowing taxa from across Anura. We found novel character-states supporting the monophyly of Odontophrynus, Proceratophrys, and Odontophrynus + Macrogenioglottus. The character-states observed in O. cultripes support conflicting phylogenetic positions within Odontophrynus. A comparison of some novel character-states with a diverse sample of burrowing taxa suggests that some modifications of the foot musculature might be involved in digging. Fil: Blotto Acuña, Boris Leonardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales ; Argentina. Universidade de Sao Paulo; Brasil Fil: Pereyra, Martín Oscar. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales ; Argentina Fil: Faivovich, Julián. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales ; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Biodiversidad y Biología Experimental; Argentina Fil: Dos Santos Dias, Pedro Henrique. Universidade de Sao Paulo; Brasil Fil: Grant, Taran. Universidade de Sao Paulo; Brasil

Amézquita et al. (2017) recently concluded that species of the Allobates femoralis group are toxic to mice at levels equivalent to syntopic alkaloid-containing poison frogs, which they attributed to the presence of alkaloids in skin secretions. However, the chemical composition of skin secretions was not analyzed, and here we present additional data supporting the absence of alkaloids in skin secretions of the Allobates femoralis group. Instead, we suggest the observed toxicity was caused by the anesthetic benzocaine, which was applied to the buccal cavity to euthanize frogs prior to skin removal. We show that orally administered benzocaine is rapidly incorporated into the skin of species that sequester and do not sequester alkaloids, which casts doubt on the conclusion that Allobates femoralis group skin secretions are toxic and makes the results of experiments with alkaloid-containing species of Adelphobates and Ameerega uninterpretable. To prevent experimental errors and misinterpretations in studies of amphibian chemical defense, we encourage researchers to test the chemical composition of samples prior to experimentation, include all necessary controls to detect false positives, conduct small pilot studies for new methods, and consider the limitations of particular methods and their ability to address the intended research questions.

The amount of short wavelength (ultraviolet (UV), violet and blue) light that reaches the retina depends on the transmittance properties of the ocular media, especially the lens, and varies greatly across species in all vertebrate groups studied previously. We measured the lens transmittance in 32 anuran amphibians with different habits, geographical distributions and phylogenetic positions and used them together with eye size and pupil shape to evaluate the relationship with diel activity pattern, elevation and latitude. We found an unusually high lens UV transmittance in the most basal species, and a cut-off range that extends into the visible spectrum for the rest of the sample, with lenses even absorbing violet light in some diurnal species. However, other diurnal frogs had lenses that transmit UV light like the nocturnal species. This unclear pattern in the segregation of ocular media transmittance and diel activity is shared with other vertebrates and is consistent with the absence of significant correlations in our statistical analyses. Although we did not detect a significant phylogenetic effect, closely related species tend to have similar transmittances, irrespective of whether they share the same diel pattern or not, suggesting that anuran ocular media transmittance properties might be related to phylogeny.

We describe a new species of the Rhinella acrolopha group (previously Rhamphophryne) from mid-elevations (1800–2500 m) of the Cordillera Occidental of Colombia. It is found exclusively in cloud forest habitats and is not associated with streams or other bodies of water. The species is characterized by possessing eight presacral vertebrae, fusion of the sacrum and urostyle, and nuptial excrescences in adult males, and in lacking conspicuous cranial ornamentation and vocal slits. The most striking characteristic of this species is its middle ear, which lacks a tympanic membrane and annulus but possesses a short stapes that articulates with the palatoquadrate and squamosal in a manner similar to the middle ear of many salamanders. A population of this species in the Serrania de los Paraguas seems to be stable despite drastic declines in many sympatric species.