Distribution and diversification of Adelphobates, emblematic poison frogs from Brazilian Amazonia

Adelphobates contains three species, and the inaccurate identification of A. quinquevittatus and the scarcity of records of A. castaneoticus complicate inference of their distributions; the latter species occurs in sympatry with A. galactonotus. Our objective was to revise the distributions of Adelphobates by compiling data and modeling habitat suitability, as range limits may be shaped by landscape features and biotic interactions. We initially analyzed the existence of operational taxonomic units within the nominal species and subsequently inferred the observed and potential distributions, taking into account the possible independent lineages for the three species, and we also generated a molecular timetree to understand the chronology of interspecific diversification events. Adelphobates quinquevittatus was found to have a more easterly distribution than previously described, and specimens with phenotypic variation were found to occur in areas inconsistent with the modeling, and A. castaneoticus was concentrated in the Tapajós-Xingu interfluve, surrounded by A. galactonotus. Models indicated that the right bank of the Xingu River is suitable for both species, indeed, both were found there. Despite Adelphobates species having their distributions delimited by major Amazonian rivers, estimated divergence times predate the formation of the modern river network, suggesting that other mechanisms were involved in their diversification.

Marine introgressions and Andean uplift have driven diversification in neotropical Monkey tree frogs (Anura, Phyllomedusinae)

The species richness in the Neotropics has been linked to environmental heterogeneity and a complex geological history. We evaluated which biogeographic processes were associated with the diversification of Monkey tree frogs, an endemic clade from the Neotropics. We tested two competing hypotheses: the diversification of Phyllomedusinae occurred either in a "south-north" or a "north-south" direction in the Neotropics. We also hypothesized that marine introgressions and Andean uplift had a crucial role in promoting their diversification. We used 13 molecular markers in a Bayesian analysis to infer phylogenetic relationships among 57 species of Phyllomedusinae and to estimate their divergence times. We estimated ancestral ranges based on 12 biogeographic units considering the landscape modifications of the Neotropical region. We found that the Phyllomedusinae hypothetical ancestor range was probably widespread throughout South America, from Western Amazon to Southern Atlantic Forest, at 29.5 Mya. The Phyllomedusines' ancestor must have initially diverged through vicariance, generally followed by jump-dispersals and sympatric speciation. Dispersal among areas occurred mostly from Western Amazonia towards Northern Andes and the South American diagonal of dry landscapes, a divergent pattern from both "south-north" and "north-south" diversification hypotheses. Our results revealed a complex diversification process of Monkey tree frogs, occurring simultaneously with the orogeny of Northern Andes and the South American marine introgressions in the last 30 million years.

Repetitive DNA Mapping in Five Genera of Tree Frogs (Amphibia: Anura) from the Atlantic Forest: New Highlights on Genomic Organization in Hylidae

INTRODUCTION

The tribes Cophomantini, Scinaxini, and Dendropsophini are anurans that belong to Hylidae, with wide distribution in tropical and subtropical regions around the world. The taxonomy and systematics of this family remain in a state of ongoing revision. Previous cytogenetic analyses of genera Boana, Bokermannohyla, Ololygon, Scinax, and Dendropsophus described some karyotypic characters such as conventional staining, C-banding and NORs, and FISH with specific probes.

METHODS

This study describes for the first time the karyotypes of four species: Bokermannohyla ibitipoca, Ololygon luizotavioi, Dendropsophus bipunctatus, and Dendropsophus ruschii. Furthermore, we map CA(15) and CAT(10) microsatellite sites for the aforementioned species and six more species from the same genera for insight into the chromosomal evolution within the subfamily Hyalinae.

RESULTS

B. ibitipoca and O. luizotavioi had 2n = 24 and karyotypic formulas 18m + 4sm + 2st and 8m + 12sm + 4st, while D. bipunctatus and D. ruschii showed 2n = 30 and karyotypic formulas 12m + 12sm + 4st + 2t and 10m + 10sm + 6st + 4t, respectively. The diploid numbers and karyotypic formulas revealed here follow the previously reported trend for Hylidae, except B. ibitipoca has a particularity of eight metacentric chromosomes, more than what is commonly found in species of this genus. The microsatellites probes CA(15) and CAT(10) had markings accumulated in blocks in the centromeric, pericentromeric, and terminal regions that were more specific for some species, as well as markings scattered along the chromosomes. We present a comprehensive review table of current data on cytogenetics of these genera.

CONCLUSION

Our findings showed that the karyotypes of the hylids studied here majority fit the postulated conserved diploid number (2n = 24) and morphological chromosome patterns, while the mapping of the microsatellites enabled us to detect differences between species that share similar chromosomal morphologies.

The Louisiana Amphibian Monitoring Program from 1997 to 2017: Results, analyses, and lessons learned

To determine trends in either frog distribution or abundance in the State of Louisiana, we reviewed and analyzed frog call data from the Louisiana Amphibian Monitoring Program (LAMP). The data were collected between 1997 and 2017 using North American Amphibian Monitoring Program protocols. Louisiana was divided into three survey regions for administration and analysis: the Florida Parishes, and 2 areas west of the Florida parishes called North and South. Fifty-four routes were surveyed with over 12,792 stops and 1,066 hours of observation. Observers heard 26 species of the 31 species reported to be in Louisiana. Three of the species not heard were natives with ranges that did not overlap with survey routes. The other two species were introduced species, the Rio Grande Chirping Frog (Eleutherodactylus cystignathoides) and the Cuban Treefrog (Osteopilus septentrionalis). Both seem to be limited to urban areas with little to no route coverage. The 15 most commonly occurring species were examined in detail using the percentage of stops at which they observed along a given survey and their call indices. Most species exhibited a multimodal, concave, or convex pattern of abundance over a 15-year period. Among LAMP survey regions, none of the species had synchronous population trends. Only one group of species, winter callers, regularly co-occur. Based on the species lists, the North region could be seen as a subset of the South. However, based on relative abundance, the North was more similar to Florida parishes for both the winter and summer survey runs. Our analyses demonstrate that long-term monitoring (10 years or more) may be necessary to determine population and occupancy trends, and that frog species may have different local demographic patterns across large geographic areas.

Toward an understanding of tree frog (Hyla japonica) for predator deterrence

Gene-encoded peptides with distinct potent bioactivities enable several animals to take advantage of fierce interspecific interaction, as seen in the skin secretion of amphibians. Unlike, most amphibian species that frequently switches terrestrial-aquatic habitats and hides easily from terrestrial predators, tree frogs of small body size are considered as the vulnerable prey in the arboreal habitat. Here, we show the structural and functional diversity of peptide families based on the skin transcriptome of Hyla japonica, which has evolved to be wrapped as an efficient chemical toolkit for defensive use in arboreal habitat. Generally, the presence of antimicrobial peptide and proteinase inhibitor families reveals the functional consistency of Hyla japonica skin compared to other amphibian species. Furthermore, we found that Anntoxin-like neurotoxins with high expression levels are species-specific in tree frogs. Interestingly, derivatives in the Anntoxin-like family exhibit multiple evolutionary traits in modifying the copy number, folding type, and three-dimensional architecture, which are considered essential for targeting the ion channels of terrestrial predators. Together, our study not only reveals the peptide diversity in the skin secretion of H. japonica, but also draws insights into the predator-deterring strategy for coping with arboreal habitat.

Hidden by the name: A new fluorescent pumpkin toadlet from the Brachycephalus ephippium group (Anura: Brachycephalidae)

Species of Brachycephalus has been having taxonomical issues due its morphological similarity and genetic conservatism. Herein, we describe a new species of Brachycephalus from the south Mantiqueira mountain range and semidecidual forests in the municipalities of Mogi das Cruzes, Campinas and Jundiaí, state of São Paulo, Brazil, based on an integrative approach. It can be distinguished from all species of the B. ephippium species group based on morphological characters (especially osteology and head shape), advertisement call and divergence in partial mitochondrial DNA gene sequences (16S). The new species is genetically similar to B. margaritatus and morphologically similar to B. ephippium. It can be differentiated from B. ephippium by the presence of dark faded spots on skull and post-cranial plates, presence of black connective tissue connective tissue scattered over dorsal musculature, parotic plate morphology, smaller snout-vent length (adult SVL: males 13.46-15.92 mm; females 16.04-17.69 mm) and 3% genetic distance. We also present natural history data and discuss the robustness of the integrative approach, geographic distribution, genetic data, behaviour, fluorescence in ontogeny, and conservation status.

The Diversity and Evolution of Sex Chromosomes in Frogs

Frogs are ideal organisms for studying sex chromosome evolution because of their diversity in sex chromosome differentiation and sex-determination systems. We review 222 anuran frogs, spanning ~220 Myr of divergence, with characterized sex chromosomes, and discuss their evolution, phylogenetic distribution and transitions between homomorphic and heteromorphic states, as well as between sex-determination systems. Most (~75%) anurans have homomorphic sex chromosomes, with XY systems being three times more common than ZW systems. Most remaining anurans (~25%) have heteromorphic sex chromosomes, with XY and ZW systems almost equally represented. There are Y-autosome fusions in 11 species, and no W-/Z-/X-autosome fusions are known. The phylogeny represents at least 19 transitions between sex-determination systems and at least 16 cases of independent evolution of heteromorphic sex chromosomes from homomorphy, the likely ancestral state. Five lineages mostly have heteromorphic sex chromosomes, which might have evolved due to demographic and sexual selection attributes of those lineages. Males do not recombine over most of their genome, regardless of which is the heterogametic sex. Nevertheless, telomere-restricted recombination between ZW chromosomes has evolved at least once. More comparative genomic studies are needed to understand the evolutionary trajectories of sex chromosomes among frog lineages, especially in the ZW systems.

Frank Beach Award Winner: Lessons from poison frogs on ecological drivers of behavioral diversification

Variation in natural behavior is tightly linked to the ecological resources with which they co-evolved. This review discusses poison frog behavior and neuroendocrinology to illustrate how ecological factors drive diversification of behavior and its underlying neural mechanisms. Poison frogs show tremendous diversity in reproductive strategies that are tightly linked to water resources in their environment. Different species utilize particular pool sizes to rear their offspring, which has selected for sex differences in parental behavior among poison frog species. Tadpole behavior reflects the behavioral diversity of adults, where tadpoles can display social group living or violent aggression and begging behavior, which are all associated with pool size and occupancy. Using this behavioral diversity among poison frog species, we have identified core brain regions, like the hippocampus and preoptic area, as being involved in regulating different aspects of amphibian parental behavior. In contrast to core brain regions, the neuromodulators governing these behaviors seem to be more labile across species. This work exemplifies how comparative studies are a prime experimental system to study how evolution tunes neural circuits that give rise to the diversity of behaviors we observe in the natural world. Finally, this review ends on a more important form of diversity - that of our scientific community - and how community outreach, decolonization of field based science, and inclusion of groups historically excluded from conducting research are needed for the scientific enterprise to transform into something truly beneficial for all members of our society.

Fifty years after: A taxonomic revision of the amphibian species from the Ecuadorian biodiversity hotspot Abra de Zamora, with description of two new Pristimantis species

Abra de Zamora is an important biodiversity hotspot in southern Ecuador. Between 1938 and 2010, eleven species of frogs were described from here: Lynchius flavomaculatus, Gastrotheca psychrophila, Pristimantis balionotus, P. colodactylus, P. cryptomelas, P. percultus, P. versicolor, P. vidua, Telmatobius cirrhacelis, P. andinognomus, and Atelopus podocarpus. Unfortunately, many of these species were not re-encountered after their original description, and for the majority DNA samples were not available, making their phylogenetic position unknown. In this study, we assess the current state of the amphibians from Abra de Zamora, by: i. redescribing the species which were first reported from the area, by contributing genetic delimitation (for L. flavomaculatus, P. balionotus, P. colodactylus, P. percultus, and P. vidua), release call (L. flavomaculatus) and advertisement call descriptions (for P. balionotus, P. vidua and P. versicolor); ii. presenting an updated amphibian species list of Abra de Zamora, with the description of two additional Pristimantis species; iii. updating the distribution of these species, including data collected in similar montane habitats from surrounding areas; and iv. amending recommendations regarding their conservation status.

Determining levels of cryptic diversity within the endemic frog genera, Indirana and Walkerana, of the Western Ghats, India

A large number of species in the tropics are awaiting discovery, many due to their cryptic morphology ie. lack of discernable morphological difference. We explored the presence of cryptic lineages within the frog genera, Indirana and Walkerana, which are endemic to the Western Ghats of Peninsular India. By reconstructing a phylogeny using 5 genes and robust geographic sampling, we delimited 19 lineages along a population—species continuum, using multiple criteria including haplotype clusters, genetic distance, morphological distinctness, and geographical separation. Of these 19 lineages, 14 belonged to the genus Indirana and 5 to the genus Walkerana. Divergence dating analyses revealed that the clade comprising Indirana and Walkerana began diversifying around 71 mya and the most recent common ancestor of Indirana and Walkerana split around 43 mya. We tested for the presence of cryptic lineages by examining the relationship between genetic and morphological divergence among related pairs within a pool of 15 lineages. The pairs showed strong morphological conservatism across varying levels of genetic divergence. Our results highlight the prevalence of morphologically cryptic lineages in these ancient endemic clades of the Western Ghats. This emphasizes the significance of other axes, such as geography, in species delimitation. With increasing threats to amphibian habitats, it is imperative that cryptic lineages are identified so that appropriate conservation measures can be implemented.

Multiple origins of green coloration in frogs mediated by a novel biliverdin-binding serpin

Many vertebrates have distinctive blue-green bones and other tissues due to unusually high biliverdin concentrations-a phenomenon called chlorosis. Despite its prevalence, the biochemical basis, biology, and evolution of chlorosis are poorly understood. In this study, we show that the occurrence of high biliverdin in anurans (frogs and toads) has evolved multiple times during their evolutionary history, and relies on the same mechanism-the presence of a class of serpin family proteins that bind biliverdin. Using a diverse combination of techniques, we purified these serpins from several species of nonmodel treefrogs and developed a pipeline that allowed us to assemble their complete amino acid and nucleotide sequences. The described proteins, hereafter named biliverdin-binding serpins (BBS), have absorption spectra that mimic those of phytochromes and bacteriophytochromes. Our models showed that physiological concentration of BBSs fine-tune the color of the animals, providing the physiological basis for crypsis in green foliage even under near-infrared light. Additionally, we found that these BBSs are most similar to human glycoprotein alpha-1-antitrypsin, but with a remarkable functional diversification. Our results present molecular and functional evidence of recurrent evolution of chlorosis, describe a biliverdin-binding protein in vertebrates, and introduce a function for a member of the serpin superfamily, the largest and most ubiquitous group of protease inhibitors.

Rapid adaptation to invasive predators overwhelms natural gradients of intraspecific variation

Invasive predators can exert strong selection on native populations. If selection is strong enough, populations could lose the phenotypic variation caused by adaptation to heterogeneous environments. We compare frog tadpoles prior to and 14 years following invasion by crayfish. Prior to the invasion, populations differed in their intrinsic developmental rate, with tadpoles from cold areas reaching metamorphosis sooner than those from warm areas. Following the invasion, tadpoles from invaded populations develop faster than those from non-invaded populations. This ontogenetic shift overwhelmed the intraspecific variation between populations in a few generations, to the point where invaded populations develop at a similar rate regardless of climate. Rapid development can have costs, as fast-developing froglets have a smaller body size and poorer jumping performance, but compensatory growth counteracts some costs of development acceleration. Strong selection by invasive species can disrupt local adaptations by dampening intraspecific phenotypic variation, with complex consequences on lifetime fitness.

Yellow sea mediated segregation between North East Asian Dryophytes species

While comparatively few amphibian species have been described on the North East Asian mainland in the last decades, several species have been the subject of taxonomical debates in relation to the Yellow sea. Here, we sampled Dryophytes sp. treefrogs from the Republic of Korea, the Democratic People's Republic of Korea and the People's Republic of China to clarify the status of this clade around the Yellow sea and determine the impact of sea level change on treefrogs' phylogenetic relationships. Based on genetics, call properties, adult morphology, tadpole morphology and niche modelling, we determined the segregated status species of D. suweonensis and D. immaculatus. We then proceeded to describe a new treefrog species, D. flaviventris sp. nov., from the central lowlands of the Republic of Korea. The new species is geographically segregated from D. suweonensis by the Chilgap mountain range and known to occur only in the area of Buyeo, Nonsan and Iksan in the Republic of Korea. While the Yellow sea is the principal element to the current isolation of the three clades, the paleorivers of the Yellow sea basin are likely to have been the major factor for the divergences within this clade. We recommend conducting rapid conservation assessments as these species are present on very narrow and declining ranges.

Chromosome evolution in Lophyohylini (Amphibia, Anura, Hylinae)

The hyline tribe Lophyohylini includes 87 species of treefrogs, of which cytogenetics aspects have been studied in less than 20% of them. In order to evaluate the evolution of some of its chromosome characters (NOR position, C-bands, and DAPI/CMA₃ bands), we studied the karyotypes of 21 lophyohylines, 16 of them for the first time, and analyzed them in a phylogenetic context. Most species showed similar karyotypes regarding chromosome number (2n = 24) and morphology (FN = 48), excepting Phyllodytes edelmoi and Osteocephalus buckleyi with 2n = 22 (FN = 44) and 2n = 28 (FN = 50), respectively. The NOR location was variable among species and provided valuable phylogenetic information. This marker was located in pair 11 in all species of Trachycephalus, Itapotihyla langsdorffii, and Nyctimantis arapapa, representing the plesiomorphic condition of Lophyohylini. Besides, other apomorphic states were recovered for the clades comprising N. rugiceps and N. siemersi (NOR in pair 5), and Dryaderces pearsoni, Osteocephalus, and Osteopilus (NOR in pair 9). Phyllodytes presented variation for NORs position; they were in pair 2 in P. edelmoi, pair 7 in P. melanomystax, and pair 8 in P. gyrinaethes and P. praeceptor. Polymorphisms in size, number, and activity of this marker were observed for N. siemersi, Osteocephalus fuscifacies, and some species of Trachycephalus. Remarkably, in N. siemersi NORs were detected on a single chromosome in the two specimens studied by this technique, raising the question of how this complex polymorphism is maintained. Interstitial telomeric sequences were found in P. edelmoi, P. melanomystax, and Osteocephalus buckleyi, and their presence seems to be not related to the chromosome reorganization events. Finally, some species showed spontaneous rearrangements, possibly as a consequence of an uncommon phenomenon in anuran cytogenetics: the presence of fragile sites or secondary constrictions not associated with NORs. We propose that this rare feature would have played an important role in the evolution of this group of frogs. From the evidence obtained in this and previous studies, we conclude that Lophyohylini presents a complex chromosome evolution.

Polyploidy breaks speciation barriers in Australian burrowing frogs Neobatrachus

Polyploidy has played an important role in evolution across the tree of life but it is still unclear how polyploid lineages may persist after their initial formation. While both common and well-studied in plants, polyploidy is rare in animals and generally less understood. The Australian burrowing frog genus Neobatrachus is comprised of six diploid and three polyploid species and offers a powerful animal polyploid model system. We generated exome-capture sequence data from 87 individuals representing all nine species of Neobatrachus to investigate species-level relationships, the origin and inheritance mode of polyploid species, and the population genomic effects of polyploidy on genus-wide demography. We describe rapid speciation of diploid Neobatrachus species and show that the three independently originated polyploid species have tetrasomic or mixed inheritance. We document higher genetic diversity in tetraploids, resulting from widespread gene flow between the tetraploids, asymmetric inter-ploidy gene flow directed from sympatric diploids to tetraploids, and isolation of diploid species from each other. We also constructed models of ecologically suitable areas for each species to investigate the impact of climate on differing ploidy levels. These models suggest substantial change in suitable areas compared to past climate, which correspond to population genomic estimates of demographic histories. We propose that Neobatrachus diploids may be suffering the early genomic impacts of climate-induced habitat loss, while tetraploids appear to be avoiding this fate, possibly due to widespread gene flow. Finally, we demonstrate that Neobatrachus is an attractive model to study the effects of ploidy on the evolution of adaptation in animals.

Progesterone: An enigmatic ligand for the mineralocorticoid receptor

The progesterone receptor (PR) mediates progesterone regulation of female reproductive physiology, as well as gene transcription in non-reproductive tissues, such as brain, bone, lung and vasculature, in both women and men. An unusual property of progesterone is its high affinity for the mineralocorticoid receptor (MR), which regulates electrolyte transport in the kidney in humans and other terrestrial vertebrates. In humans, rats, alligators and frogs, progesterone antagonizes activation of the MR by aldosterone, the physiological mineralocorticoid in terrestrial vertebrates. In contrast, in elephant shark, ray-finned fishes and chickens, progesterone activates the MR. Interestingly, cartilaginous fishes and ray-finned fishes do not synthesize aldosterone, raising the question of which steroid(s) activate the MR in cartilaginous fishes and ray-finned fishes. The simpler synthesis of progesterone, compared to cortisol and other corticosteroids, makes progesterone a candidate physiological activator of the MR in elephant sharks and ray-finned fishes. Elephant shark and ray-finned fish MRs are expressed in diverse tissues, including heart, brain and lung, as well as, ovary and testis, two reproductive tissues that are targets for progesterone, which together suggests a multi-faceted physiological role for progesterone activation of the MR in elephant shark and ray-finned fish. The functional consequences of progesterone as an antagonist of some terrestrial vertebrate MRs and as an agonist of fish and chicken MRs are not fully understood. The physiological activities of progesterone through binding to vertebrate MRs merits further investigation.

Four new species of Pristimantis Jiménez de la Espada, 1870 (Anura: Craugastoridae) in the eastern Amazon

The Pristimantis genus (Anura: Craugastoridae) is the most diverse among all vertebrates with 531 described species. The highest diversity occurs in Ecuador (215 species), followed by Colombia (202), Peru (139), Venezuela (60), Brazil (30), Bolivia (17), Guyana (6) Suriname and French Guiana (5). The genus is divided into 11 species groups. Of these, the P. conspicillatus group (containing 34 species), distributed in extreme southeastern Costa Rica, Isla Taboga (Panama), northern South America (from Colombia to eastern Guyana), south Bolivia, and is the best represented in Brazil (16 species). The main characteristics of this group are the tympanic membrane and tympanic annulus distinct (except in P. johannesdei); dorsum smooth or shagreen; dorsal lateral fold present or absent; usually smooth belly, but may be weakly granular in some species; toe V slightly larger than the toe III. Most of the taxonomic inconsistencies in species of Pristimantis could be due to its much conserved morphology and the lack of comprehensive taxonomic evaluations. Thus, an ongoing challenge for taxonomists dealing with the Pristimantis genus is the ubiquitous abundance of cryptic species. In this context, accurate species delimitation should integrate evidences of morphological, molecular, bioacoustics and ecological data, among others. Based on an integrative taxonomy perspective, we utilize morphological, molecular (mtDNA) and bioacoustic evidence to describe four new species of the Pristimantis conspicillatus group from the eastern Amazon basin. Pristimantis giorgiisp. nov. is known from the Xingu/Tocantins interfluve and can be distinguished from the other Pristimantis species of the region by presenting discoidal fold, dorsolateral fold absent, vocalization composed of three to four notes and genetic distance of 7.7% (16S) and 14.8% (COI) from P. latro, the sister and sympatric species with respect P. giorgiisp. nov.. Pristimantis pictussp. nov. is known to the northern Mato Grosso state, Brazil, and can be distinguished from the other species of Pristimantis by presenting the posterior surface of the thigh with light yellow patches on a brown background, also extending to the inguinal region, vocalization consisting of four to five notes and a genetic distance of 11.6% (16S) and 19.7% (COI) from P. pluviansp. nov., which occurs in sympatry. Pristimantis pluviansp. nov. is known to the northern Mato Grosso state, Brazil, and may be distinguished from the other Pristimantis species by having a posterior surface of the thigh reddish and vocalization composed of two notes. Pristimantis moasp. nov. is known to the northern Tocantins state and southwestern Maranhão state. This species can be distinguished from the other Pristimantis species by possessing slightly perceptible canthal stripe, external thigh surface with dark yellow spots on brown background, vocalization consisting of three to five notes and genetic distance of 2.3–11.7 (16S) and 10.5–23.1 (COI) for the new Pristimantis species of this study.

One step beyond a broad molecular phylogenetic analysis: Species delimitation of Adenomera marmorata Steindachner, 1867 (Anura: Leptodactylidae)

Taxonomists always have had intense discussions about how species should be delimited and recently many studies have used integrative approaches by combining molecular, morphological, and bioacoustic data. Although these studies are paramount for understanding species diversity, few of them actually formalize species delimitations to the final step of nomenclatural acts. Historically, the Neotropical frog genus Adenomera has been considered as a difficult taxonomic group because it comprises many morphologically similar species exhibiting high levels of intraspecific polymorphism. A recent work using molecular data shed light on the phylogenetic relationships within the genus and identified several lineages that may correspond to undescribed species but did not delimit species boundaries. In the Atlantic Forest, a clade formed by A. marmorata and two putative species (Adenomera sp. J and Adenomera sp. K) were identified. In this paper, we combine morphological, acoustic, and molecular data in order to evaluate species limits within this Atlantic Forest Adenomera clade. We provide a redescription of A. marmorata and restrict its type locality to the Tijuca Massif, in the Municipality of Rio de Janeiro, Brazil. Our results do not support A. marmorata and the two candidate species as diagnosable distinct species. Therefore A. marmorata corresponds to a species with pronounced morphological and acoustic variation in the genus and a complex phylogeographic structure.

Diversity of Antimicrobial Peptides in Three Partially Sympatric Frog Species in Northeast Asia and Implications for Evolution

Antimicrobial peptides (AMPs) are evolutionarily ancient molecules that play an essential role in innate immunity across taxa from invertebrates to vertebrates. The evolution system of AMP system has not been well explained in the literature. In this study, we cloned and sequenced AMP transcriptomes of three frog species, namely Rana dybowskii, Rana amurensis, and Pelophylax nigromaculatus, which are partially sympatric in northeast Asia, but show different habitat preferences. We found that each species contained 7 to 14 families of AMPs and the diversity was higher in species with a large geographic range and greater habitat variation. All AMPs are phylogenetically related but not associated with the speciation process. Most AMP genes were under negative selection. We propose that the diversification and addition of novel functions and improvement of antimicrobial efficiency are facilitated by the expansion of family members and numbers. We also documented significant negative correlation of net charges and numbers of amino acid residues between the propiece and mature peptide segments. This supports the Net Charge Balance Hypothesis. We propose the Cut Point Sliding Hypothesis as a novel diversification mechanism to explain the correlation in lengths of the two segments.

Genomewide analysis of microsatellite markers based on sequenced database in two anuran species

Eukaryotic and prokaryotic cell genomes exhibit multiple microsatellites. In this study, we characterized microsatellites in genomes and genes of Nanorana parkeri and Xenopus laevis. This characterization was used for gene ontology (GO) analysis of coding sequences (CDS). Compared to the genome of N. parkeri, the genome of X. laevis is larger and contains more number of microsatellites, but the diversity of both species are similar. Trinucleotide repeats in the genome of N. parkeri and dinucleotide and tetranucleotide repeats inthe genome of X. laevis were the most diverse. In both the species, diversity of microsatellites was highest in intergenic regions, followed by intron and exon regions, and lowest in coding regions. Microsatellites in CDS are thus subject to higher selective pressure. Many microsatellites are concentrated upstream and downstream of genes in both species, suggesting suppression of repeats in the middle of protein-CDS. Repeats are enriched in regions near gene termini purely due to the biophysical constraints of protein structure. In GO analysis, two and five unique GO terms, only found in N. parkeri and X. laevis, respectively, indicate advantageous mutations during species evolution. Biological process, cellular component and molecular function ontology reflected in the GO analysis predicted that the microsatellites located in CDS can alter protein function and may provide a molecular basis for species adaptation to new and changing environments.

Phylogenetic relationships and systematics of the Amazonian poison frog genus Ameerega using ultraconserved genomic elements

The Amazonian poison frog genus Ameerega is one of the largest yet most understudied of the brightly colored genera in the anuran family Dendrobatidae, with 30 described species ranging throughout tropical South America. Phylogenetic analyses of Ameerega are highly discordant, lacking consistency due to variation in data types and methods, and often with limited coverage of species diversity in the genus. Here, we present a comprehensive phylogenomic reconstruction of Ameerega, utilizing state-of-the-art sequence capture techniques and phylogenetic methods. We sequenced thousands of ultraconserved elements from over 100 tissue samples, representing almost every described Ameerega species, as well as undescribed cryptic diversity. We generated topologies using maximum likelihood and coalescent methods and compared the use of maximum likelihood and Bayesian methods for estimating divergence times. Our phylogenetic inference diverged strongly from those of previous studies, and we recommend steps to bring Ameerega taxonomy in line with the new phylogeny. We place several species in a phylogeny for the first time, as well as provide evidence for six potential candidate species. We estimate that Ameerega experienced a rapid radiation approximately 7-11 million years ago and that the ancestor of all Ameerega was likely an aposematic, montane species. This study underscores the utility of phylogenomic data in improving our understanding of the phylogeny of understudied clades and making novel inferences about their evolution.

A review of the elusive bicolored iris Snouted Treefrogs (Anura: Hylidae:Scinax uruguayus group)

The genus Scinax currently includes more than 120 species, recovered in two major clades, the S. catharinae and the S. ruber clades. The latter comprises 75 species, most of which remain unassigned to any species groups, while 12 are included in the S. rostratus and S. uruguayus groups. In this paper we present a taxonomic review of the two species currently included in the S. uruguayus group, discussing some putative phenotypic synapomorphies of this group. Although S. pinima and S. uruguayus have been considered as distinct species, this has been based on scant evidence, and several authors doubted of their distinctiveness. Our study of available specimens of S. pinima and S. uruguayus corroborates that both are valid and diagnosable species based on phenotypic evidence. Furthermore, our results show that S. pinima previously known only from its type locality, has a much widespread distribution than previously thought (including the Brazilian states of Paraná, Santa Catarina, and Rio Grande do Sul), which, added to the biological information presented here allows to suggest the removal of this species from the "Data Deficient" IUCN Red List category to "Least Concern". Also, we describe a new species formerly reported as S. aff. pinima and S. uruguayus from NE Argentina and some localities from the Brazilian State of Rio Grande do Sul. All species are diagnosed and characterized using adult and larval morphology, osteology, vocalizations, cytogenetics, and natural history.

Species complexes and the importance of Data Deficient classification in Red List assessments: The case of Hylobatrachus frogs

Taxonomy is the cornerstone of extinction risk assessments. Currently, the IUCN Red List treats species complexes either under a single overarching species name—resulting in an unhelpfully broad circumscription and underestimated threat assessment that does not apply to any one species lineage—or omits them altogether—resulting in the omission of species that should be assessed. We argue that taxonomic uncertainty alone, as in species complexes, should be grounds for assessment as Data Deficient (DD). Yet, use of the DD category is currently discouraged, resulting in assessments based on poor data quality and dismissal of the importance of taxonomic confidence in conservation. This policy may be leading to volatile and unwarranted assessments of hundreds of species across the world, and needs to be revised. To illustrate this point, we here present a partial taxonomic revision of torrent frogs from eastern Madagascar in the Mantidactylus subgenus Hylobatrachus. Two named species, Mantidactylus (Hylobatrachus) lugubris and M. (H.) cowanii, and several undescribed candidate species are recognised, but the application of the available names has been somewhat ambiguous. In a recent re-assessment of its conservation status, M. (H.) lugubris was assessed including all complex members except M. (H.) cowanii within its distribution, giving it a status of Least Concern and distribution over most of eastern Madagascar. After describing two of the unnamed lineages as Mantidactylus (Hylobatrachus) atsimo sp. nov. (from southeastern Madagascar) and Mantidactylus (Hylobatrachus) petakorona sp. nov. (from the Marojejy Massif in northeastern Madagascar), we show that Mantidactylus (Hylobatrachus) lugubris is restricted to the central east of Madagascar, highlighting the inaccuracy of its current Red List assessment. We propose to re-assess its status under a more restrictive definition that omits well-defined candidate species, thus representing the actual species to which its assessment refers, to the best of current knowledge. We recommend that for species complexes in general, (1) nominal lineages that can be confidently restricted should be assessed under the strict definition, (2) non-nominal species-level lineages and ambiguous names should be prioritised for taxonomic research, and (3) ambiguous names should be assessed as DD to highlight the deficiency in data on their taxonomic status, which is an impediment to their conservation. This would reduce ambiguity and underestimation of threats involved in assessing species complexes, and place the appropriate emphasis on the importance of taxonomy in anchoring conservation.

Comparative Analysis of Anuran Amphibian Skin Microbiomes Across Inland and Coastal Wetlands

Amphibians host a community of microbes on their skin that helps resist infectious disease via the dual influence of anti-pathogenic microbial species and emergent community dynamics. Many frogs rely on freshwater habitats, but salinization is rapidly increasing saltwater concentrations in wetlands around the globe, increasing the likelihood that frogs will come into contact with salt-contaminated habitats. Currently, we know little about how increased salt exposure will affect the symbiotic relationship between the skin microbes and frog hosts. To better understand how salt exposure in a natural context affects the frog skin microbiome, we use Hyla cinerea, a North American treefrog species that can inhabit brackish wetlands, to explore three questions. First, we determine the extent that microbial communities in the environment and on frog skin are similar across populations. Second, we assess the microbial species richness and relative abundance on frogs from habitats with different salinity levels to determine how salinity affects the microbiome. Third, we test whether the relative abundances of putatively pathogen-resistant bacterial species differ between frogs from inland and coastal environments. We found that the frog microbiome is more similar among frogs than to the microbial communities found in surface water and soil, but there is overlap between frog skin and the environmental samples. Skin microbial community richness did not differ among populations, but the relative abundances of microbes were different across populations and salinities. We found no differences in the relative abundances of the anti-fungal bacteria Janthinobacterium lividum, the genus Pseudomonas, and Serratia marcescens, suggesting that environmental exposure to saltwater has a limited influence on these putatively beneficial bacterial taxa.

On the road to Mandalay: contribution to the Microhyla Tschudi, 1838 (Amphibia: Anura: Microhylidae) fauna of Myanmar with description of two new species

We present a morphological and molecular assessment of the Microhyla fauna of Myanmar based on new collections from central (Magway Division) and northern (Kachin State) parts of the country. In total, six species of Microhyla are documented, including M. berdmorei, M. heymonsi, M. butleri, M. mukhlesuri and two new species described from the semi-arid savanna-like plains of the middle part of the Irrawaddy (Ayeyarwady) River Valley. We used a 2 481 bp long 12S rRNA-16S rRNA fragment of mtDNA to hypothesize genealogical relationships within Microhyla. We applied an integrative taxonomic approach combining molecular, morphological, and acoustic lines of evidence to evaluate the taxonomic status of Myanmar Microhyla. We demonstrated that the newly discovered populations of Microhyla sp. from the Magway Division represent two yet undescribed species. These two new sympatric species are assigned to the M. achatina species group, with both adapted to the seasonally dry environments of the Irrawaddy Valley. Microhyla fodiens sp. nov. is a stout-bodied species with a remarkably enlarged shovel-like outer metatarsal tubercle used for burrowing and is highly divergent from other known congeners (P-distance≥8.8%). Microhyla irrawaddy sp. nov. is a small-bodied slender frog reconstructed as a sister species to M. kodial from southern India (P-distance=5.3%); however, it clearly differs from the latter both in external morphology and advertisement call parameters. Microhyla mukhlesuri is reported from Myanmar for the first time. We further discuss the morphological diagnostics and biogeography of Microhyla species recorded in Myanmar.

Early ontogeny and sequence heterochronies in Leiuperinae frogs (Anura: Leptodactylidae)

The study of early development in Neotropical Leiuperinae frogs (Anura, Leptodactylidae) has been addressed by several works in recent times. However, a comparative developmental approach under a phylogenetic context was not available. Herein we analyzed the morphological and ontogenetic diversity of embryos belonging to 22 species of the three largest genera in Leiuperinae. We find that in most cases, variations fit with the phylogeny at the inter- and intrageneric levels. Embryo kyphosis and whitish color are synapomorphies for the clade grouping Physalaemus and Engystomops. The presence of a third lower tooth row on the oral disc is plesiomorphic for Leiuperinae, only changing in derived clades. The configurations and developmental trajectories of the lower lip are exceptionally diverse. The developmental sequences optimized on the phylogenetic tree recover an early differentiated first lower tooth row a synapomorphy of Pseudopaludicola and Physalaemus, and an early differentiated second row as synapomorphy of Pleurodema. On the other hand, few features are highly conserved in the subfamily, such as the adhesive glands universally present in a type-C configuration. Our results also suggest that the morphology and ontogeny of embryos is in some cases associated to the environment where they develop. A large body size, poorly developed transient respiratory structures, large yolk provision and delayed development of the digestive tract occur convergently in embryos inhabiting cold, oxygenated environments. Embryos that develop in warmer water bodies in xeric environments show more complex and persistent transient respiratory structures and an early onset of hind limbs development. Our survey highlights that morphology and early development of anurans can be a valuable source of information for phylogenetic studies, and provide fundamental bases to explore and discuss how evolutionary changes can be shaped by environmental conditions.

Mitochondrial Introgression, Color Pattern Variation, and Severe Demographic Bottlenecks in Three Species of Malagasy Poison Frogs, Genus Mantella

Madagascar is a biodiversity hotspot particularly rich in amphibian diversity and only a few charismatic Malagasy amphibians have been investigated for their population-level differentiation. The Mantellamadagascariensis group is composed of two rainforest and three swamp forest species of poison frogs. We first confirm the monophyly of this clade using DNA sequences of three nuclear and four mitochondrial genes, and subsequently investigate the population genetic differentiation and demography of the swamp forest species using one mitochondrial, two nuclear and a set of nine microsatellite markers. Our results confirm the occurrence of two main mitochondrial lineages, one dominated by Mantellaaurantiaca (a grouping supported also by our microsatellite-based tree) and the other by Mantellacrocea + Mantellamilotympanum. These two main lineages probably reflect an older divergence in swamp Mantella. Widespread mitochondrial introgression suggests a fairly common occurrence of inter-lineage gene flow. However, nuclear admixture seems to play only a limited role in this group, and the analyses of the RAG-1 marker points to a predominant incomplete lineage sorting scenario between all five species of the group, which probably diverged relatively recently. Our demographic analyses show a common, severe and recent demographic contraction, inferred to be in temporal coincidence with the massive deforestation events that took place in the past 1000 years. Current data do not allow to conclusively delimit independent evolutionary units in these frogs, and we therefore refrain to suggest any taxonomic changes.

Morphological and ecological convergence at the lower size limit for vertebrates highlighted by five new miniaturised microhylid frog species from three different Madagascan genera

Miniaturised frogs form a fascinating but poorly understood amphibian ecomorph and have been exceptionally prone to taxonomic underestimation. The subfamily Cophylinae (family Microhylidae), endemic to Madagascar, has a particularly large diversity of miniaturised species which have historically been attributed to the single genus Stumpffia largely based on their small size. Recent phylogenetic work has revealed that several independent lineages of cophyline microhylids evolved towards highly miniaturised body sizes, achieving adult snout-vent lengths under 16 mm. Here, we describe five new species belonging to three clades that independently miniaturised and that are all genetically highly divergent from their relatives: (i) a new genus (Mini gen. nov.) with three new species from southern Madagascar, (ii) one species of Rhombophryne, and (iii) one species of Anodonthyla. Mini mum sp. nov. from Manombo in eastern Madagascar is one of the smallest frogs in the world, reaching an adult body size of 9.7 mm in males and 11.3 mm in females. Mini scule sp. nov. from Sainte Luce in southeastern Madagascar is slightly larger and has maxillary teeth. Mini ature sp. nov. from Andohahela in southeast Madagascar is larger than its congeners but is similar in build. Rhombophryne proportionalis sp. nov. from Tsaratanana in northern Madagascar is unique among Madagascar's miniaturised frogs in being a proportional dwarf, exhibiting far less advanced signs of paedomorphism than other species of similar size. Anodonthyla eximia sp. nov. from Ranomafana in eastern Madagascar is distinctly smaller than any of its congeners and is secondarily terrestrial, providing evidence that miniaturisation and terrestriality may be evolutionarily linked. The evolution of body size in Madagascar's microhylids has been more dynamic than previously understood, and future studies will hopefully shed light on the interplay between ecology and evolution of these remarkably diverse frogs.

Folk taxonomy and indigenous names for frogs in Zululand, South Africa

BACKGROUND

We use taxonomy to organize the world into recognizable units. Folk taxonomy deals with the naming and classification of organisms through culture. Unlike its scientific counterpart, folk taxonomy is mostly undocumented, the Zoological Code of Nomenclature does not regulate it, and the resulting names are specific to each culture. A growing body of literature is steadily shedding light on the principles underlying this pre-scientific taxonomy. Vernacular names can be an instrument to increase participation of non-scientists in biodiversity matters. In South Africa, great strides have been made in standardizing and increasing relatability of vernacular amphibian names in English and Afrikaans. However, there is a need to achieve the same with the country's autochthonous languages which are used by a majority of the population.

METHODS

This study investigates amphibian-related folk taxonomy using a semi-structured interview process in KwaZulu-Natal's Zululand region and  pilots methods of applying folk taxonomy principles to compile a comprehensive list of standardized indigenous frog names.

RESULTS

Folk taxonomy in Zululand is systematic, developed, and bears similarities to other indigenous taxonomies around the world. Similarities also exist between folk and scientific taxonomy. Six uninomial indigenous names were found to be used for the 58 amphibian species occurring in the study area. The 58 species were assigned individual indigenous names using folk taxonomy guidelines supplemented with guidelines for modern taxonomies.

CONCLUSIONS

There is a gap in the documentation and investigation of amphibian folk taxonomy in South Africa. Standardization of indigenous frog names is required to increase their universality. Similarities between folk and modern taxonomies allow for supplementation of indigenous guidelines when compiling a comprehensive indigenous species list. Through this study, social inclusion in wildlife matters is increased, indigenous knowledge systems are promoted, and a contribution is made to the development of an indigenous South African language.

Chance or choice? Understanding parasite selection and infection in multi-host communities

Ongoing debate over the relationship between biodiversity and disease risk underscores the need to develop a more mechanistic understanding of how changes in host community composition influence parasite transmission, particularly in complex communities with multiple hosts. A key challenge involves determining how motile parasites select among potential hosts and the degree to which this process shifts with community composition. Focusing on interactions between larval amphibians and the pathogenic trematode Ribeiroia ondatrae, we designed a novel, large-volume set of choice chambers to assess how the selectivity of free-swimming infectious parasites varied among five host species and in response to changes in assemblage composition (four different permutations). In a second set of trials, cercariae were allowed to contact and infect hosts, allowing comparison of host-parasite encounter rates (parasite choice) with infection outcomes (successful infections). Cercariae exhibited consistent preferences for specific host species that were independent of the community context; large-bodied amphibians, such as larval bullfrogs (Rana catesbeiana), exhibited the highest level of parasite attraction. However, because host attractiveness was decoupled from susceptibility to infection, assemblage composition sharply affected both per-host infection as well as total infection (summed among co-occurring hosts). Species such as the non-native R. catesbeiana functioned as epidemiological 'sinks' or dilution hosts, attracting a disproportionate fraction of parasites relative to the number that established successfully, whereas Taricha granulosa and especially Pseudacris regilla supported comparatively more metacercariae relative to cercariae selection. These findings provide a framework for integrating information on parasite preference in combination with more traditional factors such as host competence and density to forecast how changes within complex communities will affect parasite transmission.

Expansion of the known distribution of the coastal tailed frog, Ascaphus truei, in British Columbia, Canada, using robust eDNA detection methods

The coastal tailed frog (Ascaphus truei) is endemic to the Pacific Northwest of North America and is listed as a species of Special Concern under the Canadian Species at Risk Act. Its range is limited to British Columbia where it occurs widely west of the Coast Mountain Ranges extending north almost to the Alaskan Panhandle. The present study focused on surveying within the Cayoosh, Bridge (Shulaps), Seton, Anderson, Carpenter, and Downton Lake drainages. Four years of previous inventory efforts using conventional time-constrained search (TCS) methods detected tailed frog at 23/292 discrete sites (7.9% detection rate) in seven watersheds. Non-invasive environmental DNA (eDNA) methods hold promise for cryptic and low-abundance species detection. We rigorously validated a quantitative real-time polymerase chain reaction (qPCR)-based tool for detecting coastal tailed frog eDNA in water samples. This eASTR4 test is highly specific and sensitive. We applied a two-step targeted eDNA analysis approach on duplicate filtered water samples from a total of 72 sites collected over five days. The first IntegritE-DNA step mitigates false negative results and tests all DNA samples for the ability to support amplification from endogenous plant chloroplast DNA as a measure of sample viability. Three DNA samples failed this step even after inhibitor clean up suggesting that these samples were poor quality and not reliable for targeted species’ DNA analyses. All other DNA samples were deemed viable and were then tested for species-specific DNA. Coastal tailed frog eDNA was detected in 55/72 (76%) discrete stream reaches; nine sites with historical known occurrence were all eDNA positive. The false negative rate for TCS compared to eDNA methods was 58%. The results expand known coastal tailed frog distribution to 24 watersheds effectively more than tripling extant occurrences and confirm a previously suspected, apparently isolated coastal tailed frog metapopulation in the Shulaps drainage.

New microhylid frog genus from Peninsular India with Southeast Asian affinity suggests multiple Cenozoic biotic exchanges between India and Eurasia

Anurans in Peninsular India exhibit close biogeographical links with Gondwana as well as Laurasia, often explainable by the geological history of the Indian subcontinent; its breakup from Gondwanan landmasses followed by long isolation that resulted in diversification of endemic lineages, and subsequent land connections with Asia that enabled dispersal of widespread groups. Although widely distributed, the frog subfamily Microhylinae mostly comprises of geographically restricted genera found either in Southeast and East Asia or Peninsular India and Sri Lanka. Here we report a previously unknown microhylid from the Western Ghats in Peninsular India with closest relatives found over 2,000 km away in Southeast Asia. Based on integrated evidence from mitochondrial and nuclear DNA, adult and tadpole morphology, hand musculature, male advertisement call, and geographical distance, we recognize this enigmatic frog as a distinct new species and genus endemic to the Western Ghats. The discovery of Mysticellus franki gen. et sp. nov. and its close evolutionary relationship with the Southeast Asian genus Micryletta also provide insights on the biogeography of Microhylinae. Genus-level divergences within the subfamily suggest multiple Cenozoic biotic exchange events between India and Eurasia, particularly through postulated Eocene land bridges via Southeast Asia prior to accretion of the two landmasses.

Speciation in a biodiversity hotspot: Phylogenetic relationships, species delimitation, and divergence times of Patagonian ground frogs from the Eupsophus roseus group (Alsodidae)

The alsodid ground frogs of the Eupsophus genus are divided into two groups, the roseus (2n = 30) and vertebralis (2n = 28), which are distributed throughout the temperate Nothofagus forests of South America. Currently, the roseus group is composed by four species, while the vertebralis group consists of two. Phylogenetic relationships and species delimitation within each group are controversial. In fact, previous analyses considered that the roseus group was composed of between four to nine species. In this work, we evaluated phylogenetic relationships, diversification times, and species delimitation within the roseus group using a multi-locus dataset. For this purpose, mitochondrial (D-loop, Cyt b, and COI) and nuclear (POMC and CRYBA1) partial sequences from 164 individuals were amplified, representing all species. Maximum Likelihood (ML) and Bayesian approaches were used to reconstruct phylogenetic relationships. Species tree was estimated using BEAST and singular value decomposition scores for species quartets (SVDquartets). Species limits were evaluated with six coalescent approaches. Diversification times were estimated using mitochondrial and nuclear rates with LogNormal relaxed clock in BEAST. Nine well-supported monophyletic lineages were recovered in Bayesian, ML, and SVDquartets, including eight named species and a lineage composed by specimens from the Villarrica population (Bootstrap:>70, PP:> 0.99). Single-locus species delimitation analyses overestimated the species number in E. migueli, E. calcaratus, and E. roseus lineages, while multi-locus analyses recovered as species the nine lineages observed in phylogenetic analyses (Ctax = 0.69). It is hypothesized that Eupsophus diversification occurred during Mid-Pleistocene (0.42-0.14 Mya), with most species having originated after the Last Southern Patagonian Glaciation (0.18 Mya). Our results revitalize the hypothesis that the E. roseus group is composed of eight species and support the Villarrica lineage as a new putative species.

Past vicariance promoting deep genetic divergence in an endemic frog species of the Espinhaço Range in Brazil: The historical biogeography of Bokermannohyla saxicola (Hylidae)

The highland endemic frog Bokermannohyla saxicola occurs within the Espinhaço Range, the most extensive and continuous orogenic belt of the Brazilian territory, located in southeastern Brazil. We used mitochondrial DNA markers to test for spatial structure, to investigate the likely influence of past vicariant events, to evaluate demographic dynamics along the species range, and to understand the role of habitat discontinuities in promoting connectivity and diversity along the range. We found four major monophyletic lineages, each one associated with distinct mountain tops. The divergence time found between the four main clades clearly pre-dated the Pleistocene, except for the most recent separation. We observed no signs of population expansion for most of the sampling sites along the range, and a higher genetic diversity in the most continuous and central highland plateau, compared to smaller marginal regions. The Espinhaço Range harbors four deeply divergent lineages of B. saxicola within areas restricted by barriers for millions of years. These relatively isolated populations were kept apart by discontinuities represented by lowland habitats between mountain tops. Most of the lineage divergences occurred earlier than the Pleistocene, thus they cannot be solely explained by climatic oscillations of this epoch. However, within-lineage divergence times were all dated from the Pleistocene, suggesting an important effect in population dynamics. We also suggest that some marginal populations like those from Serra Negra and Serra de Itacambira can be the result of recent colonization events. Finally, in the southern Espinhaço region, the most continuous central highland area shows greater genetic diversity than the marginal discontinuous areas, where we have also observed a significant correlation between genetic and geographic distances. Bokermannohyla saxicola is a good model to study the biogeography of the Espinhaço Range because its high genetic structure reflects ancient as well as recent geological/climatic events, with important implications for conservation.

Diversity of miniaturized frogs of the genus Adelophryne (Anura: Eleutherodactylidae): A new species from the Atlantic Forest of northeast Brazil

The number of species of frogs in the South American genus Adelophryne has increased in recent years, and it has become apparent that this group contains a substantial amount of undescribed diversity. Currently the genus contains nine described species and five candidate species. Here we describe the tenth species of the genus Adelophryne from the municipality of Igrapiúna, southern Bahia state, Brazil. The new species is characterized by its small body size, indistinct tympanum, and two phalanges in the finger IV. The species of the genus are distributed in three groups, Northern Amazonia Clade, Northern Atlantic Forest Clade and Southern Atlantic Forest Clade. The new species is phylogenetically related to species of the Northern Atlantic Forest Clade of Adelophryne and restricted to forested habitat, as typical for other Adelophryne. The species is restricted to the pristine forests in the type locality, and we consider its conservation status as Near Threatened. New morphological and molecular data of other Adelophryne species are presented, extending the distribution of Adelophryne sp. 2, Adelophryne sp. 4, Adelophryne mucronata and Adelophryne glandulata. However, a more comprehensive revision of the diversity and phylogenetic position of most Adelophryne species is needed, and the evolutionary relationships of A. meridionalis and A. pachydactyla remain unknown.

A new minute Pristimantis (Amphibia: Anura: Strabomantidae) from the Andes of southern Ecuador

We describe a new rainfrog species (Pristimantis), from the wetland complex Oña, Nabón, Saraguro and Yacuambi, in the Andes of southern Ecuador, at altitudes ranging between 3000–3400 m a.s.l. Pristimantis tiktik sp. nov. is a small frog, displaying sexual dimorphism (the males with dorsum of various shades of gray, brown, orange or green and a whitish or pinkish yellow venter; females with brownish gray or gray dorsum and a reticulated white and black venter), with SVL ranging between 19.7–20.4 mm in females (n = 3) and 16.1–18.4 mm in males (n = 6). The skin on dorsum is tuberculated, that on venter is coarsely areolate, dorsolateral folds are absent, tympanic membrane is absent but the tympanic annulus is evident, cranial crests are absent, discs on fingers just slightly expanded, heel is lacking enlarged tubercles, inner edge of tarsus is bearing a long fold, Toe V is slightly longer than Toe III and the iris coloration is bronze with fine black reticulations. The males have a large subgular vocal sac that extends onto the chest and vocal slits but lack nuptial pads. The unique advertisement call consists of long duration series of periodically repeated clicks: “tik”. Molecular analyses place the new species in the recently resurrected P. orestes group, as the sister species of the assemblage that contains P. bambu, P. mazar, P. simonbolivari and an undescribed species.

Conservation genetics of two threatened frogs from the Mambilla highlands, Nigeria

Amphibians are the vertebrate group with the highest number of species threatened with extinction, and habitat loss and fragmentation are considered to be among the leading causes of their declines and extinctions. Little is known of the population biology of amphibian species inhabiting montane forests in Central and West Africa, where anthropogenic activities such as farming and cattle raising are major threats to native biodiversity. We used Amplified Fragment Length Polymorphisms (AFLPs) to assess the population genetic structure of two poorly known species, Cardioglossa schioetzi and Leptodactylodon bicolor (both in the Arthroleptidae), in and around Ngel Nyaki Forest Reserve on the Mambilla Plateau in eastern Nigeria. The landscape comprises continuous forest on steep slopes and small riparian forest fragments in a grassland matrix. While increased fragmentation is well documented for these and other forests in the mountains of Cameroon and Nigeria over the past century, there are no previous assessments of the impact of forest fragmentation on montane amphibian populations in this region. Our estimates of genetic diversity are similar across populations within each species with levels of heterozygosity values consistent with local population declines. Except for a pair of populations (C. schioetzi) we did not observe genetic differentiation between forest and riparian forest fragment populations, nor across sites within continuous forest (L. bicolor). Our results demonstrate recent gene flow between forest fragments and the adjacent protected forests and suggest that small forest corridors connecting these may lessen the genetic consequences of at least 30 years of intense and severe fragmentation in Ngel Nyaki.

A new species of the genus Theloderma Tschudi, 1838 (Amphibia: Anura: Rhacophoridae) from Tay Nguyen Plateau, central Vietnam

A new species of small tree frog from a primary montane tropical forest of central Vietnam, Tay Nguyen Plateau, is described based on morphological, molecular, and acoustic evidence. The Golden Bug-Eyed Frog, Theloderma auratum sp. nov., is distinguishable from its congeners and other small rhacophorid species based on a combination of the following morphological attributes: (1) bony ridges on head absent; (2) smooth skin completely lacking calcified warts or asperities; (3) pointed elongated tapering snout; (4) vocal opening in males absent; (5) vomerine teeth absent; (6) males of small body size (SVL 21.8-26.4 mm); (7) head longer than wide; ED/SVL ratio 13%-15%; ESL/SVL ratio 16%-20%; (8) small tympanum (TD/EL ratio 50%-60%) with few tiny tubercles; (9) supratympanic fold absent; (10) ventral surfaces completely smooth; (11) webbing between fingers absent; (12) outer and inner metacarpal tubercles present, supernumerary metacarpal tubercle single, medial, oval in shape; (13) toes half-webbed: I 2-2¼ II 1½-2¾ III 2-3¼ IV 3-1½ V; (14) inner metatarsal tubercle present, oval; outer metatarsal tubercle absent; (15) iris bicolored; (16) dorsal surfaces golden-yellow with sparse golden-orange speckling or reticulations and few small dark-brown spots; (17) lateral sides of head and body with wide dark reddish-brown to black lateral stripes, clearly separated from lighter dorsal coloration by straight contrasting edge; (18) ventral surfaces of body, throat, and chest greyish-blue with indistinct brown confluent blotches; (19) upper eyelids with few (3-5) very small flat reddish superciliary tubercles; (20) limbs dorsally reddish-brown, ventrally brown with small bluish-white speckles. The new species is also distinct from all congeners in 12S rRNA to 16S rRNA mitochondrial DNA fragment sequences (uncorrected genetic distance P>8.9%). Advertisement call and tadpole morphology of the new species are described. Our molecular data showed Theloderma auratum sp. nov. to be a sister species of Th. palliatum from Langbian Plateau in southern Vietnam.

Chromosome evolution in Cophomantini (Amphibia, Anura, Hylinae)

The hylid tribe Cophomantini is a diverse clade of Neotropical treefrogs composed of the genera Aplastodiscus, Boana, Bokermannohyla, Hyloscirtus, and Myersiohyla. The phylogenetic relationships of Cophomantini have been comprehensively reviewed in the literature, providing a suitable framework for the study of chromosome evolution. Employing different banding techniques, we studied the chromosomes of 25 species of Boana and 3 of Hyloscirtus; thus providing, for the first time, data for Hyloscirtus and for 15 species of Boana. Most species showed karyotypes with 2n = 2x = 24 chromosomes; some species of the B. albopunctata group have 2n = 2x = 22, and H. alytolylax has 2n = 2x = 20. Karyotypes are all bi-armed in most species presented, with the exception of H. larinopygion (FN = 46) and H. alytolylax (FN = 38), with karyotypes that have a single pair of small telocentric chromosomes. In most species of Boana, NORs are observed in a single pair of chromosomes, mostly in the small chromosomes, although in some species of the B. albopunctata, B. pulchella, and B. semilineata groups, this marker occurs on the larger pairs 8, 1, and 7, respectively. In Hyloscirtus, NOR position differs in the three studied species: H. alytolylax (4p), H. palmeri (4q), and H. larinopygion (1p). Heterochromatin is a variable marker that could provide valuable evidence, but it would be necesserary to understand the molecular composition of the C-bands that are observed in different species in order to test its putative homology. In H. alytolylax, a centromeric DAPI+ band was observed on one homologue of chromosome pair 2. The band was present in males but absent in females, providing evidence for an XX/XY sex determining system in this species. We review and discuss the importance of the different chromosome markers (NOR position, C-bands, and DAPI/CMA3 patterns) for their impact on the taxonomy and karyotype evolution in Cophomantini.

Revisiting the phylogeography, demography and taxonomy of the frog genus Ptychadena in the Ethiopian highlands with the use of genome-wide SNP data

Understanding the diversification of biological lineages is central to evolutionary studies. To properly study the process of speciation, it is necessary to link micro-evolutionary studies with macro-evolutionary mechanisms. Micro-evolutionary studies require proper sampling across a taxon's range to adequately infer genetic diversity. Here we use the grass frogs of the genus Ptychadena from the Ethiopian highlands as a model to study the process of lineage diversification in this unique biodiversity hotspot. We used thousands of genome-wide SNPs obtained from double digest restriction site associated DNA sequencing (ddRAD-seq) in populations of the Ptychadena neumanni species complex from the Ethiopian highlands in order to infer their phylogenetic relationships and genetic structure, as well as to study their demographic history. Our genome-wide phylogenetic study supports the existence of approximately 13 lineages clustered into 3 species groups. Our phylogenetic and phylogeographic reconstructions suggest that those endemic lineages diversified in allopatry, and subsequently specialized to different habitats and elevations. Demographic analyses point to a continuous decrease in the population size across the majority of lineages and populations during the Pleistocene, which is consistent with a continuous period of aridification that East Africa experienced since the Pliocene. We discuss the taxonomic implications of our analyses and, in particular, we warn against the recent practice to solely use Bayesian species delimitation methods when proposing taxonomic changes.

Seasonality and brain size are negatively associated in frogs: evidence for the expensive brain framework

The challenges of seasonal environments are thought to contribute to brain evolution, but in which way is debated. According to the Cognitive Buffer Hypothesis (CBH) brain size should increase with seasonality, as the cognitive benefits of a larger brain should help overcoming periods of food scarcity via, for instance, increased behavioral flexibility. However, in line with the Expensive Brain Framework (EBF) brain size should decrease with seasonality because a smaller brain confers energetic benefits in periods of food scarcity. Empirical evidence is inconclusive and mostly limited to homoeothermic animals. Here we used phylogenetic comparative analyses to test the impact of seasonality on brain evolution across 30 species of anurans (frogs) experiencing a wide range of temperature and precipitation. Our results support the EBF because relative brain size and the size of the optic tectum were negatively correlated with variability in temperature. In contrast, we found no association between the variability in precipitation and the length of the dry season with either brain size or the sizes of other major brain regions. We suggest that seasonality-induced food scarcity resulting from higher variability in temperature constrains brain size evolution in anurans. Less seasonal environments may therefore facilitate the evolution of larger brains in poikilothermic animals.

Coalescent-based delimitation outperforms distance-based methods for delineating less divergent species: the case of Kurixalus odontotarsus species group

Few empirical studies have compared coalescent-based methods to distance-based methods for delimitation of less divergent species. In this study, we used two coalescent-based (BFD and BPP) and two distance-based barcoding (ABGD and jMOTU) methods to delimit closely related species in the Kurixalus odontotarsus species group. Phylogenetic analyses revealed that the K. odontotarsus species group comprises 11 distinct maternal clades with strong support values. Based on the genetic and morphological evidences, we consider that species diversity in the K. odontotarsus species group was underestimated and the 11 clades represent 11 species, of which six are unnamed. The coalescent-based delimitations decisively supported the scenario of 11-species corresponding to the 11 clades. However, the distance-based ABGD only obtained 3-6 candidate species, which is not consistent with morphological evidence. These results indicate that BFD and BPP are more conservative than ABGD to false negatives (lumping). Method of fixed threshold (jMOTU) may obtain a resolution similar to that inferred by BFD and BPP, but it severely relies on subjective choice of the threshold and lacks statistical support. We consider that coalescent-based BFD and BPP approaches outperform distance-based methods for delineation of less divergent species.

The hatching process and mechanisms of adaptive hatching acceleration in hourglass treefrogs, Dendropsophus ebraccatus

Environmentally cued hatching is well documented in anurans, enabling embryos to escape diverse threats. However, knowledge of anuran hatching mechanisms is limited and based largely on aquatic-breeding species without known plasticity in hatching timing. Generally, hatching gland cells produce a hatching enzyme that degrades the vitelline membrane. We investigated hatching and its regulation in terrestrial embryos of hourglass treefrogs, Dendropsophus ebraccatus, which accelerate hatching to escape dehydration. We specifically tested if changes in hatching gland cell development or hatching enzyme gene expression are associated with accelerated hatching. We measured perivitelline chamber size of well-hydrated eggs over development as an indicator of breakdown of the vitelline membrane and found that the size of the perivitelline chamber increased steadily until hatching, suggesting gradual hatching enzyme release and vitelline membrane degradation. Hatching gland cells peaked in abundance and began regression substantially prior to hatching, but we found no developmental differences in the abundance or surface area of hatching gland cells between dry and well-hydrated embryos. Hatching enzyme gene expression also peaked early in development then declined, with no difference between hydration treatments. In D. ebraccatus breakdown of the vitelline membrane appears gradual, mediated by hatching enzyme release starting long before hatching. However, hatching acceleration is not associated with ontogenetic changes in hatching gland cell development or hatching enzyme gene expression. This hatching process contrasts with that of red-eyed treefrogs, Agalychnis callidryas, which appear to release enzyme acutely at hatching, yet both species are capable of hatching to escape acute threats.

Unrevealing the leaf frogs Cerrado diversity: A new species of Pithecopus (Anura, Arboranae, Phyllomedusidae) from the Mato Grosso state, Brazil

The Neotropical frog genus Pithecopus comprises currently 10 species. A recent molecular phylogeny suggested the existence of two subclades within it, one of them including P. palliatus, P. azureus, P. hypochondrialis, and P. nordestinus (lowland species). Herein we describe a new species of this subclade from Pontal do Araguaia, in the Brazilian Cerrado in the Mato Grosso state. Recognition of the new species is supported by adult morphology, advertisement call and molecular data. The new species differs from Pithecopus highland species by its smaller head width and lack of the reticulate pattern on flanks. From lowland species, the new form differs by being significantly smaller in snout vent-length, advertisement call with the greatest number of pulses, and high genetic distance. Interestingly, we also report on occurrence of P. hypochondrialis (its sister species) at an adjacent site (about 3km). Also, we report on the occurrence of the new species in the Chapada dos Guimarães and Santa Terezinha, both also in the Mato Grosso state.

Acoustic differentiation and behavioral response reveals cryptic species within Buergeria treefrogs (Anura, Rhacophoridae) from Taiwan

Buergeria japonica is a widely distributed treefrog occurring from Ryukyu Archipelago to Taiwan. Across this wide distributional range, we combined molecular, acoustic, morphological, and behavioral characters to clarify the taxonomic status among these insular populations. Genetic differentiation in mitochondrial sequences indicated an over 16% divergence among two deeply divergent clades: Japanese clade distributes in Ryukyu Archipelago and northwestern drainages of Taiwan, while Taiwanese clade distributes in the remaining drainages on Taiwan. The Taiwanese clade can be distinguished from the nominative species not only by molecular and morphological differences, but also distinguishable by considerable acoustic differentiation, which is extraordinarily noticeable for an additional type of long call that never recorded from Japanese clade. The two clades form a parapatric distribution pattern with narrow contact zones both in western and eastern Taiwan. Playback experiments indicated that male frogs show significantly stronger defensiveness against conspecific calls rather than heterospecific calls, indicating that these signals play a crucial role in species recognition. Here we describe the Taiwanese clade as a new species; the behavioral response and the magnitude of gene flow across their contact zones are especially worth for detailed studies.

Colouration in amphibians as a reflection of nutritional status: The case of tree frogs in Costa Rica

Colouration has been considered a cue for mating success in many species; ornaments in males often are related to carotenoid mobilization towards feathers and/or skin and can signal general health and nutrition status. However, there are several factors that can also link with status, such as physiological blood parameters and body condition, but there is not substantial evidence which supports the existence of these relationships and interactions in anurans. This study evaluated how body score and blood values interact with colouration in free-range Agalychnis callidryas and Agalychnis annae males. We found significant associations between body condition and plasmatic proteins and haematocrit, as well as between body condition and colour values from the chromaticity diagram. We also demonstrated that there is a significant relation between the glucose and plasmatic protein values that were reflected in the ventral colours of the animals, and haematocrit inversely affected most of those colour values. Significant differences were found between species as well as between populations of A. callidryas, suggesting that despite colour variation, there are also biochemical differences within animals from the same species located in different regions. These data provide information on underlying factors for colouration of male tree frogs in nature, provide insights about the dynamics of several nutrients in the amphibian model and how this could affect the reproductive output of the animals.

Species delimitation in frogs from South American temperate forests: The case of Eupsophus, a taxonomically complex genus with high phenotypic variation

One of the most characteristic and abundant amphibian taxa of South American temperate forests is Eupsophus. The ten currently recognized species of the genus have been divided in two species groups, roseus and vertebralis, but most of them, eight, belong to the roseus group. Recent phylogeographic and phylogenetic studies have suggested that species diversity of the roseus group could be underestimated. An examination of the literature shows that species of the roseus group exhibit high levels of variation in their external characteristics, particularly those used as diagnostic characters, which compromises their taxonomy and hinders their field recognition. High levels of variation were also observed in several new populations of the roseus group discovered in southern Chile (36°-40°S), which could not be identified to the species level by their external characteristics. On the other hand, the literature reveals a scarse karyotype differentiation and a high bioacoustic uniformity among the species of the roseus group. We performed a Bayesian phylogenetic analysis using mitochondrial and nuclear genes to reevaluate the species diversity of the roseus group, including all the nominal species of Eupsophus and new populations. This analysis was complemented with three species delimitation approaches, General Mixed Yule Coalescent, multi-rate Poisson Tree Process and Automatic Barcode Gap Discovery. We favored a conservative delimitation of only four species for the roseus group, a result more consistent with the distribution of pairwise genetic distances, and the available chromosome and bioacoustic evidence. The four recognized lineages, which have nearly completely allopatric distributions, are named after the earliest nominal species that they include, but because high levels of phenotypic variation, they are not diagnosable by consistent differences in external morphology. We discuss the implications of this new proposal for the taxonomy and conservation of the genus, and the possible causes of the difficulty to estimate its species diversity.

Skin microbiota in frogs from the Brazilian Atlantic Forest: Species, forest type, and potential against pathogens

The cutaneous microbiota of amphibians can be defined as a biological component of protection, since it can be composed of bacteria that produce antimicrobial compounds. Several factors influence skin microbial structure and it is possible that environmental variations are among one of these factors, perhaps through physical-chemical variations in the skin. This community, therefore, is likely modified in habitats in which some ecophysiological parameters are altered, as in fragmented forests. Our research goal was to compare the skin bacterial community of four anuran species of the Atlantic Forest of Brazil in landscapes from two different environments: continuous forest and fragmented forest. The guiding hypotheses were: 1) microbial communities of anuran skin vary among sympatric frog species of the Atlantic forest; 2) the degree to which forested areas are intact affects the cutaneous bacterial community of amphibians. If the external environment influences the skin microbiota, and if such influences affect microorganisms capable of inhibiting the colonization of pathogens, we expect consequences for the protection of host individuals. We compared bacterial communities based on richness and density of colony forming units; investigated the antimicrobial potential of isolated strains; and did the taxonomic identification of isolated morphotypes. We collected 188 individual frogs belonging to the species Proceratophrys boiei, Dendropsophus minutus, Aplastodiscus leucopygius and Phyllomedusa distincta, and isolated 221 bacterial morphotypes. Our results demonstrate variation in the skin microbiota of sympatric amphibians, but only one frog species exhibited differences in the bacterial communities between populations from fragmented and continuous forest. Therefore, the variation we observed is probably derived from both intrinsic aspects of the host amphibian species and extrinsic aspects of the environment occupied by the host. Finally, we detected antimicrobial activity in 27 morphotypes of bacteria isolated from all four amphibian species.

Evolutionary and natural history of the turtle frog, Myobatrachus gouldii, a bizarre myobatrachid frog in the southwestern Australian biodiversity hotspot

Southwest Australia (SWA) is a global biodiversity hotspot and a centre of diversity and endemism for the Australo-Papuan myobatrachid frogs. Myobatrachus gouldii (the turtle frog) has a highly derived morphology associated with its forward burrowing behaviour, largely subterranean habit, and unusual mode of reproduction. Its sister genera Metacrinia and Arenophryne have restricted distributions in Western Australia with significant phylogeographic structure, leading to the recent description of a new species in the latter. In contrast, Myobatrachus is distributed widely throughout SWA over multiple climatic zones, but little is known of its population structure, geographic variation in morphology, or reproduction. We generated molecular and morphological data to test for genetic and morphological variation, and to assess whether substrate specialisation in this species may have led to phylogeographic structuring similar to that of other plant and animal taxa in SWA. We assembled sequence data for one mitochondrial and four nuclear DNA loci (3628 base pairs) for 42 turtle frogs sampled throughout their range. Likelihood phylogenetic analyses revealed shallow phylogeographic structure in the mtDNA locus (up to 3.3% genetic distance) and little variation in three of the four nDNA loci. The mtDNA haplotype network suggests five geographically allopatric groups, with no shared haplotypes between regions. These geographic patterns are congruent with several other SWA species, with genetic groups restricted to major hydrological divisions, the Swan Coastal Plain, and the Darling Scarp. The geographically structured genetic groups showed no evidence of significant morphological differentiation (242 individuals), and there was little sexual size dimorphism, but subtle differences in reproductive traits suggest more opportunistic breeding in lower rainfall zones. Call data were compared to sister genera Metacrinia and Arenophryne and found to be highly conservative across the three genera. Like many taxa in SWA, topographic variation and Plio-Pleistocene arid fluctuations likely were historic drivers of diversification in M. gouldii.

The 100th: An appealing new species of Dendropsophus (Amphibia: Anura: Hylidae) from northeastern Brazil

We describe a new species of the Dendropsophus leucophyllatus Group from the Atlantic Forest of the southern region of State of Bahia, Brazil. It can be distinguished from all species of the D. leucophyllatus Group on the basis of morphological characters (especially its unique dorsal pattern and snout in dorsal view), advertisement calls and divergence in mitochondrial DNA gene sequences. The inclusion of D. anceps on the group remains controversial but our phylogenetic analyses do not recover the new species as sister to syntopic species of the D. leucophyllatus Group (with or without D. anceps). These results also highlight the palimpsest that is past relation between the Atlantic and Amazon forests.