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How do chemically defended animals resist their own toxins? This intriguing question on the concept of autotoxicity is at the heart of how species interactions evolve. In this issue of Molecular Ecology (Molecular Ecology, 2024, 33), Bodawatta and colleagues report on how Papua New Guinean birds coopted deadly neurotoxins to create lethal mantles that protect against predators and parasites. Combining chemical screening of the plumage of a diverse collection of passerine birds with genome sequencing, the researchers unlocked a deeper understanding of how some birds sequester deadly batrachotoxin (BTX) from their food without poisoning themselves. They identified that birds impervious to BTX bear amino acid substitutions in the toxin-binding site of the voltage-gated sodium channel Nav1.4, whose function is essential for proper contraction and relaxation of vertebrate muscles. Comparative genetic and molecular docking analyses show that several of the substitutions associated with insensitivity to BTX may have become prevalent among toxic birds through positive selection. Intriguingly, poison dart frogs that also co-opted BTX in their lethal mantles were found to harbour similar toxin insensitivity substitutions in their Nav1.4 channels. Taken together, this sets up a powerful model system for studying the mechanisms behind convergent molecular evolution and how it may drive biological diversity.

Predator-prey interactions have been suggested as drivers of diversity in different lineages, and the presence of anti-predator defences in some clades is linked to higher rates of diversification. Warning signals are some of the most widespread defences in the animal world, and there is evidence of higher diversification rates in aposematic lineages. The mechanisms behind such species richness, however, are still unclear. Here, we test whether lineages that use aposematism as anti-predator defence exhibit higher levels of genetic differentiation between populations, leading to increased opportunities for divergence. We collated from the literature more than 3000 pairwise genetic differentiation values across more than 700 populations from over 60 amphibian species. We find evidence that over short geographical distances, populations of species of aposematic lineages exhibit greater genetic divergence relative to species that are not aposematic. Our results support a scenario where the use of warning signals could restrict gene flow, and suggest that anti-predator defences could impact divergence between populations and potentially have effects at a macro-evolutionary scale.

Advertisement calls in frogs have evolved to be species-specific signals of recognition and are therefore considered an essential component of integrative taxonomic approaches to identify species and delineate their distribution range. The species rich genus Microhyla is a particularly challenging group for species identification, discovery and conservation management due to the small size, conserved morphology and wide distribution of its members, necessitating the need for a thorough description of their vocalization. In this study, we provide quantitative description of the vocal behaviour of Microhyla nilphamariensis, a widely distributed south Asian species, from Delhi, India, based on call recordings of 18 individuals and assessment of 21 call properties. Based on the properties measured acrossed 360 calls, we find that a typical advertisement call of M. nilphamariensis lasts for 393.5 ±  57.5 ms, has 17 pulses on average and produce pulses at rate of 39 pulses/s. The overall call dominant frequency was found to be 2.8 KHz and the call spectrum consisted of two dominant frequency peaks centered at 1.6 KHz and 3.6 KHz, ranging between 1.5-4.1 KHz. Apart from its typical advertisement call, our study also reveals the presence of three rare call types, previously unreported in this species. We describe variability in call properties and discuss their relation to body size and temperature. We found that overall dominant frequency 1 (spectral property) was found to be correlated with body size, while first pulse period (temporal property) was found to be correlated with temperature. Further, we compare the vocal repertoire of M. nilphamariensis with that of the congener Microhyla ornata from the western coast of India and Sri Lanka and also compare the call properties of these two populations of M. ornata to investigate intra-specific call variation. We find statistically significant differentiation in their acoustic repertoire in both cases. Based on 18 call properties (out of 20), individuals of each locality clearly segregate on PCA factor plane forming separate groups. Discriminant function analysis (DFA) using PCA factors shows 100% classification success with individuals of each locality getting classified to a discrete group. This confirms significant acoustic differentiation between these species as well as between geographically distant conspecifics. The data generated in this study will be useful for comparative bioacoustic analysis of Microhyla species and can be utilized to monitor populations and devise conservation management plan for threatened species in this group.

Frogs are an ecologically diverse and phylogenetically ancient group of anuran amphibians that include important vertebrate cell and developmental model systems, notably the genus Xenopus. Here we report a high-quality reference genome sequence for the western clawed frog, Xenopus tropicalis, along with draft chromosome-scale sequences of three distantly related emerging model frog species, Eleutherodactylus coqui, Engystomops pustulosus, and Hymenochirus boettgeri. Frog chromosomes have remained remarkably stable since the Mesozoic Era, with limited Robertsonian (i.e., arm-preserving) translocations and end-to-end fusions found among the smaller chromosomes. Conservation of synteny includes conservation of centromere locations, marked by centromeric tandem repeats associated with Cenp-a binding surrounded by pericentromeric LINE/L1 elements. This work explores the structure of chromosomes across frogs, using a dense meiotic linkage map for X. tropicalis and chromatin conformation capture (Hi-C) data for all species. Abundant satellite repeats occupy the unusually long (~20 megabase) terminal regions of each chromosome that coincide with high rates of recombination. Both embryonic and differentiated cells show reproducible associations of centromeric chromatin and of telomeres, reflecting a Rabl-like configuration. Our comparative analyses reveal 13 conserved ancestral anuran chromosomes from which contemporary frog genomes were constructed.

Objective: Caffeine, an adenosine receptor antagonist, is a potent central nervous system stimulant that also impairs insulin signaling. Recent studies have suggested that coffee consumption lowers serum urate (SU) and protects against gout by unknown mechanisms. We hypothesized that caffeine lowers SU by affecting activity of urate transporters. Methods: We examined the effect of caffeine and adenosine on basal and insulin stimulation of net 14C‐urate uptake in the human renal proximal tubule cell line PTC‐05 and on individual urate transporters expressed in Xenopus laevis oocytes. Results: We found that caffeine and adenosine efficiently inhibited both basal and insulin stimulation of net 14C‐urate uptake mediated by endogenous urate transporters in PTC‐05 cells. In oocytes expressing individual urate transporters, caffeine (>0.2 mM) more efficiently inhibited the basal urate transport activity of GLUT9 isoforms, OAT4, OAT1, OAT3, NPT1, ABCG2, and ABCC4 than did adenosine without significantly affecting URAT1 and OAT10. However, unlike adenosine, caffeine at lower concentrations (<0.2 mM) very effectively inhibited insulin activation of urate transport activity of GLUT9, OAT10, OAT1, OAT3, NPT1, ABCG2, and ABCC4 by blocking activation of Akt and extracellular signal–regulated kinase. Conclusion: We postulate that inhibition of urate transport activity of the re‐absorptive transporters GLUT9, OAT10, and OAT4 by caffeine is a key mechanism in its urate‐lowering effects. Additionally, the ability of caffeine to block insulin‐activated urate transport by GLUT9a and OAT10 suggests greater relative inhibition of these transporters in hyperinsulinemia. [ABSTRACT FROM AUTHOR]

Indian fossil Squamata and Anura are known from the Upper Cretaceous-lower Paleocene Deccan Trap associated sediments for over last one century. However, current knowledge on their taxonomy and stratigraphic implications is poor for their scarce and fragmentary nature and lack of any stratigraphic constraints. We report newly found fossil Squamata and Anura from the new intertrappean locality Bharudpura in Malwa Plateau and describe (i) Scincomorpha (Scincoidea) lizards based on taxonomic study of dentary, maxilla and osteoderms, (ii) Anguimorpha (Anguidae) lizards based on osteoderms, (iii) Squamata indeterminate based on a vertebrae and (iv) Anura (Ranidae, Ranoidea and Anuran indeterminate) based on a ilium, a sacral vertebrae and single dentary. Currently, it is not possible to ascertain if the different fossil specimens belong to a single or more taxa. The lowermost lava pile of Mandleshwar and Kalisindh formations, associated with multiple intertrappean beds including the new Bharudpura fossil locality, have yielded40Ar/39Ar plateau ages from 66.834 Ma, the oldest Deccan Trap flow dated so far in India to 66.352 Ma. The present study records their earliest occurrence in India, from intertrappean associated with oldest Deccan Trap lava pile that erupted during magnetochron C30n of Maastrichtian in the Malwa Plateau. [ABSTRACT FROM AUTHOR]

Chemical pollutants include the harmful effects of various substances on soils, water bodies, and biodiversity. Amphibians are one of the most endangered groups of vertebrates and are impacted by chemical pollutants in various ways due to their complex life cycles. Since trace pollutant concentrations vary across environments, different frog ecomorphs (classified by their microhabitat use) may have different exposures. We aimed to determine the association between frog ecomorphs and the occurrence of histopathological hepatic lesions (HHLs) as an indicator of contaminant exposure. We focused on small forest streams near a large urban region in Brazil, heavily polluted in the 1980s. We examined 104 frog specimens from various families. All specimens exhibited HHLs, with melanomacrophages being the most common (n = 99). Arboreal frogs exhibited more vascular congestion, while terrestrial frogs showed structural hepatic damage. Higher cobalt levels were linked to increased liver necrosis in arboreal frogs and structural issues in both arboreal and terrestrial frogs. Cadmium was associated with hepatitis in terrestrial frogs. Although metal levels had no significant effects on rheophilic frogs, the prevalence of hepatitis and necrosis indicated complex exposure pathways. Iron and aluminum were linked to fewer lesions in rheophilic frogs, suggesting resilience. The high prevalence of HHLs signals an ongoing issue, with variations among ecomorphs suggesting differential exposure to pollutants and posing a complex challenge for community conservation. [ABSTRACT FROM AUTHOR]

Within the breeding sites of anurans, factors at the microhabitat scale can exhibit variations over the years, resulting in temporal fluctuations within these sites. These fluctuations may lead to modifications in "normal larval development" and observable phenotypic changes. These developmental alterations appear to have evolved as shared strategies for achieving reproductive success and ensuring the survival of offspring. In a population of Boana cordobae inhabiting the Central Pampean Sierras (Córdoba, Argentina), the coexistence of pre‐ and prometamorphic tadpoles throughout the year, coupled with variations in size and shape within the same developmental stage, has led us to question about the duration of the larval period, variations in the timing of developmental events, and the possible existence of distinct larval morphs for this species. Utilizing data collected over four consecutive years from various locations, we described the development, growth, and larval morphology using both linear and geometric morphometrics during the pre‐ and prometamorphic stages. Our aim was to comprehend how anuran larvae in predictable environments synchronize the timing of their phenotypic transformations with external conditions. We identified two distinct cohorts: spring–summer and autumn–spring, each exhibiting distinct rates of growth and development until metamorphosis, resulting in size discrepancies. Moreover, the physical attributes of the breeding sites influenced the size of the tadpoles. However, the observed variation in shape was not related to the ontogenetic period, cohort, or developmental site. Ultimately, the observed variations had no impact on the morphology at metamorphosis. The comprehensive data gathered from our observations in B. cordobae yield valuable insights that contribute to a deeper comprehension of anuran larval development under natural conditions where changes are predictable and follow a regular pattern throughout the year, ultimately maximizing reproductive success. [ABSTRACT FROM AUTHOR]

Amphibians are well-known for their ability to produce and secrete a mixture of bioactive substances in specialized skin glands for the purpose of antibiotic self-protection and defense against predators. Some of these secretions contain various small molecules, such as the highly toxic batrachotoxin, tetrodotoxin, and samandarine. For some time, the presence of peptides in amphibian skin secretions has attracted researchers, consisting of a diverse collection of – to the current state of knowledge – three to 104 amino acid long sequences. From these more than 2000 peptides many are known to exert antimicrobial effects. In addition, there are some reports on amphibian skin peptides that can promote wound healing, regulate immunoreactions, and may serve as antiparasitic and antioxidative substances. So far, the focus has mainly been on skin peptides from frogs and toads (Anura), eclipsing the research on skin peptides of the ca. 700 salamanders and newts (Caudata). Just recently, several novel observations dealing with caudate peptides and their structure-function relationships were reported. This review focuses on the chemistry and bioactivity of caudate amphibian skin peptides and their potential as novel agents for clinical applications. [ABSTRACT FROM AUTHOR]

Ceratophryid frogs inhabit the lowlands of South America and exhibit greater diversity in the semiarid Gran Chaco. The presence of Ceratophryidae dates back to the late Miocene on the eastern slopes of the Andes in Argentina. Herein, we describe the remains of Ceratophrys from late Miocene of Palo Pintado Formation (Salta, Argentina). Fragmentary bones were recovered from the base of the unit in beds dated between 8 and 7.7 million years ago. The specimen IBIGEO-P141 exhibits the fusion of dentary and mentomeckelian bones forming a fang, a sharp-edged lower jaw, and sculptured bones as Ceratophryidae. The granular pattern of sculpturation, differences between pars facialis and pars dentalis of maxillary, and the shape of lower jaw, support its assignment to the genus Ceratophrys. Combined bioclimatic data and geographic distribution of living Ceratophrys indicate a strong influence of precipitation variables in the distribution of these frogs with adaptations to survive long dry periods. These facts suggest a seasonal rainfall with a well-defined dry season during the deposition of lower levels of Palo Pintado Formation. The palaeoclimatic conditions resemble those occurring in the actual semiarid Chaco, and reveal that the historical geographic distribution of Ceratophryidae was retracted eastward due to the Andean uplift. [ABSTRACT FROM AUTHOR]

Identifying and quantifying the main factors that are jeopardizing amphibian communities worldwide is essential for planning effective amphibian conservation. We collected data on the presence/absence of salamanders and newts (Caudata) and frogs and toads (Anura) in >3600 water points from a large region (30,000 km2) in NW Spain during a 10‐year period (2004–2013). We contrasted a large set of hypotheses explaining presence/absence as a function of anthropogenic factors across the regional elevation gradient (1–2036 m). Logistic regression modeling revealed that salamanders and newts were mainly influenced by pollution and by land use changes, and that the effect of these factors changed with elevation. However, frogs and toads were affected by a larger set of factors acting synergistically, although not including land use changes, and their effect operated at all elevation ranges, except in the case of biological factors (invasive species and wild boar abundance) with higher effects at low elevation. Changes in land use was the most common factor at any elevation and included the abandonment of rural areas, which favors shrub and tree encroachment on former open land, and loss of water points. The most resilient species at any elevation were two frogs, Pelophylax perezi and Rana parvipalmata. The least resilient species were two salamanders, Chioglossa lusitanica and Lissotriton helveticus, followed closely by two toads, Alytes obstetricans and Pelobates cultripes. Unoccupied sites had higher frequencies of biological effects and of changes in land use in the first 5 years of study and lower frequencies of direct human influence factors in the second period. Overall, our results showed that the studied amphibian metacommunity was negatively influenced both by direct and indirect anthropogenic factors, but also that many amphibian species were not only capable of occupying sites which had been altered by human action, but were even favored by land uses generating open habitat, a habitat type that is increasingly uncommon in the region, in the entire Iberian Peninsula and in Europe. [ABSTRACT FROM AUTHOR]

Tadpoles serve as crucial evidence for testing systematic and taxonomic hypotheses. Suctorial tadpoles collected in Guyana were initially assigned to Rhaebo nasicus through molecular phylogeny. Subsequent analysis of larval and adult morphological traits revealed synapomorphies within the clade encompassing R. nasicus and R. ceratophrys, prompting the recognition of a new genus described herein as Adhaerobufo. The new genus is distinguished from other bufonids by specific phenotypic traits including an enlarged, suctorial oral disc with distinct papillae arrangements, and the presence of certain muscles and narial vacuities at the larval stage. However, only a few adult external characteristics (e.g., enlarged eyelids, infraocular cream spot), seem to be reliably discriminative from related genera. This study underscores the significance of larval morphology in anuran systematics and offers new insights into the evolution of suctorial and gastromyzophorous larvae within bufonids. [ABSTRACT FROM AUTHOR]

Habitat alteration is recognized as one of the most important drivers of biodiversity decline. Urbanization implies a major habitat alteration and its impact on biodiversity depends on type and degrees of habitat modifications. Growing cities generate great heterogeneity with respect to the uses of space that enable the preservation of a certain diversity of amphibians within the urban frame. Our objective is to understand how environments with different levels of urbanization influence local amphibian diversity. We grouped various urban green spaces of a medium-sized and growing city of Argentina in relation to natural and anthropic environmental variables which allows us to describe an urban environmental gradient and we calculate beta diversity among these groups of urban environments considering the richness, composition and abundance of amphibian at each sites' group. From this, we analyze and tested the differences in the functional diversity of amphibians in the defined urban environmental gradient. We hypothesize that: (i) the described spatial heterogeneity would be related to an elevated beta diversity of amphibians within the urban frame; and (ii) the analysis of functional diversity would reveal a stronger biotic or abiotic filtering of the focal community. We found that groups of urban environments with an intermediate degree of urbanization can present a greater functional diversity and species richness than those that are less urbanized. We identified urban avoiders (T. typhonius, P. santafecinus and P. biligonigerus) and urban tolerant species (E. bicolor, R. arenarum, R. dorbignyi, L. macrosternum, L. latinasus, P. albonotatus, D. nanus and S. nasicus). The replacement beta diversity recorded indicated that the species assemblage changes throughout urban environmental gradient, but functionally similar species thrive in the less to the most urbanized sites, allowing them to occupy the entire functional space of the groups of urban environments with different types and degrees of urbanization. [ABSTRACT FROM AUTHOR]

We here describe abundant new fossil material of amphibians and reptiles from different late Neogene localities of northern Greece: the Early Pliocene (MN 14) of Spilia 0, Spilia 1, and Spilia 2; the Early Pliocene (MN 15) of Spilia 3, Spilia 4, Spilia 5, and Vevi; and the Late Miocene or Pliocene of Chalicorrema and Rema Marmara. These new late Neogene herpetofaunas are highly diverse, documenting a considerably rich herpetofauna allowing the identification of at least two salamander, seven frog, two turtle, seven lizard, and eight snake taxa. Salamanders are represented by the salamandrid genera Ommatotriton and Ichthyosaura. Frogs are represented by the bombinatorid Bombina, the discoglossids Latonia cf. ragei and Latonia sp., the pelobatid Pelobates aff. praefuscus and Pelobates sp., the ranids Pelophylax and Rana cf. dalmatina, the hylid Hyla gr. arborea, and the bufonid Bufotes gr. viridis. Turtles are represented by the emydid Emys and an indeterminate geoemydid. Lizards are represented by the scincid Ophiomorus, two lacertids (one of which potentially pertaining to Lacerta), amphisbaenians, agamids, the anguid Pseudopus, and a potential varanid. Snakes are represented by the erycid Eryx, the natricid Natrix aff. rudabanyaensis, a small-sized elapid, an "Oriental viper", the colubriforms Periergophis and Paraxenophis, as well as two further distinct but still indeterminate morphotypes of colubriforms. For the material from Spilia tentatively referred to Ommatotriton, this is only the third occurrence in the fossil record globally. The new material of Ichthyosaura and Bombina mark the first documentation of these genera in the Greek fossil record. Abundant cranial and postcranial material from Spilia is tentatively referred to Latonia ragei, a taxon previously known from the Early Miocene of Western Europe. The new record of Pelobates represents the oldest documented occurrences of the genus in the Greek fossil record. Interestingly, the Pelobates from Spilia bears much resemblance to an extinct taxon, Pelobates aff. praefuscus, which is otherwise known from the Late Miocene of the Caucasus, and not to the extant species that currently inhabits the area. The identification of Pelophylax and Rana adds to the rather poor Neogene record of ranids from Greece. Particularly for the case of Rana cf. dalmatina from Spilia 4, this corresponds to the only documented occurrence of this extant taxon in the Greek fossil record. Similarly, the identification of Hyla gr. arborea in Spilia 1, Spilia 3, and Spilia 4, marks only the third documented occurrence of this genus in the Greek fossil record. The Bufotes material from Spilia 1, Spilia 3, and Spilia 4 represents the first documented fossil occurrence of the extant Bufotes viridis complex in Greece. The material of Emys gr. orbicularis from Vevi marks the only known pre-Quaternary record of the genus in Greece and one of the only few Neogene members of the genus known from Europe. The scincid Ophiomorus is identified in Spilia 4, known from several cranial and postcranial remains, well outside the extant range of the genus. Practically, the Spilia Ophiomorus is only the fourth known fossil occurrence of this extant genus globally and also represents one of its oldest known occurrences. Material from Spilia 1 and Spilia 3 is tentatively referred to cf. Lacerta sp., and this would mark the first known occurrence of this emblematic extant genus in the Greek fossil record, denoting the presence of the genus since at least the Early Pliocene. The new amphisbaenian specimens from Spilia 4 add to the recently described single vertebra from the same locality, and represent the youngest occurrence of amphisbaenians from continental Eastern Europe. The new agamid material from Vevi and Chalicorrema add substantially to the record of this group, which was in Greece so far known exclusively from the latest Miocene/earliest Pliocene of Maramena. A similarly important addition is the record of Pseudopus from Spilia 4, as this genus had been known in the Greek fossil record only from a very few localities. The potential varanid from Spilia represents one of the few Pliocene occurrences of this group in Europe. We identify Natrix aff. rudabanyaensis among the material from Spilia 0, Spilia 4, and Vevi, adding to the previously known record of this taxon from Maramena, however, its precise species level assignment should await a revision of Neogene European Natrix spp. The find of a small elapid from Spilia 4 represents the youngest occurrence of a coral snake from Europe, extending their statigraphic range up to the Early Pliocene (MN 14). Periergophis and Paraxenophis, two bizarre snakes, so far exclusively known from their type locality in Maramena, could be also present here, even if tentatively identified. Most notably, the new material from these localities comprises forms that are now extinct (e.g., Periergophis and Paraxenophis) or extirpated from Europe (e.g., Latonia, Varanidae, Elapidae) but at the same time also loudly attests the emergence of the extant genera that dominate the extant herpetofaunas of Greece (Ichthyosaura, Bombina, Pelobates, Pelophylax, Rana, Hyla, Bufotes, Emys, Ophiomorus, Lacerta, Pseudopus, Eryx, and Natrix), for some of which their fossil record is documented here for the first time in the area. [ABSTRACT FROM AUTHOR]

Anurans exhibit a diverse acoustic repertoire, and the release call is emitted when an individual is improperly clasped, often by males mistakenly grasping other males or unreceptive females during amplexus. The release call also serves as a crucial source for taxonomic resolution. However, for certain widespread hylid genera like Trachycephalus, knowledge about their release calls is limited or non-existent. Trachycephalus comprises 18 species, yet only one has its release call described. This study presents the first description of the release call of T. typhonius from a population in the Cerrado of Central-Western Brazil. Its release call is composed of a multipulsed note, distinguishing it from the only other known call in the genus (T. 'vermiculatus'). Given the differences in the release call parameters between these species, such variations could serve as diagnostic criteria for distinguishing the two lineages. Additional descriptions of release calls, including from more T. typhonius and T. 'vermiculatus' populations, are essential for species diagnosis and taxonomic classification. [ABSTRACT FROM AUTHOR]

During their development, amphibians undergo various physiological processes that may affect their susceptibility to environmental pollutants. Naturally occurring fluctuations caused by developmental events are often overlooked in ecotoxicological studies. Our aim is to investigate how biomarkers of oxidative stress are modulated at different stages of larval development in the Amazonian amphibian species, Physalaemus ephippifer. The premetamorphosis, prometamorphosis and metamorphic climax stages were used to analyze total antioxidant capacity (ACAP), glutathione S-transferase (GST) activity, lipid peroxidation (LPO) levels and the expression of genes nrf2, gst, gsr (glutathione reductase) and gclc (glycine-cysteine ligase, catalytic subunit). Although there was no difference in ACAP and the genes expression among the studied stages, individuals from the premetamorphosis and prometamorphosis showed higher GST activity than ones under the climax. LPO levels were highest in individuals from the metamorphic climax. The present study suggests that the oxidative status changes during ontogeny of P. ephippifer tadpoles, especially during the metamorphic climax, the most demanding developmental phase. Variations in the redox balance at different developmental stages may lead to a divergent response to pollution. Therefore, we recommend that studies using anuran larvae as biomonitors consider possible physiological differences during ontogeny in their respective analyses. [ABSTRACT FROM AUTHOR]

We describe a new species of Centrolene from the Subandean Cordillera of Kutukú in southeastern Ecuador. The new species differs from all other glassfrogs by the combination of the following characters: presence of processes of vomers but without vomerine teeth; humeral spines in males; dorsum green with light green dots and without dark marks; dorsal skin with abundant tubercles; all visceral peritonea translucent (except for pericardium); and small body size (snout-vent length 21.5–21.9 mm in adult males). The new species is sister to Centrolene camposi from the Western Cordillera of the Andes of southwestern Ecuador, and together they form a clade with C. condor from the Subandean Cóndor Cordillera in southeastern Ecuador. Our time tree suggests that the new species originated at the end of the Pliocene. In addition, we present new information for C. zarza, expanding its geographic range across the southeastern Andes and the Kutukú and Cóndor cordilleras, amending its definition and diagnosis, and offering new information on its natural history and extinction risk. We also discuss the taxonomic status of Ecuadorian populations reported as C. huilensis and conclude that they are C. muelleri based on their close phylogenetic relationships and morphological similarity to samples of C. muelleri from Peru. Centrolene huilensis is a valid species and not closely related to C. muelleri. [ABSTRACT FROM AUTHOR]

Although neobatrachians represent about 95% of anuran diversity, their fossil record, especially during the Mesozoic, remains scarce and often limited to a few damaged specimens with uncertain affinities. In South America, fossil neobatrachians have been identified from the Cretaceous deposits in Chile, Argentina, and Brazil. Here, we describe a new species of fossil neobatrachian from the Late Cretaceous (Campanian) Bauru Basin, south-eastern Brazil, based on several well-preserved specimens. The morphology of the new species was described in detail using high-resolution micro-CT, and its taxonomic affinities were investigated through a phylogenetic analysis encompassing both living and extinct taxa. The new taxon was recovered among hyloids, more specifically as closely related to other well-ossified taxa. However, due to the lack of any synapomorphies with extant families, we were unable to assign the new species to a more specific group within Neobatrachia. The discovery of a new fossil frog in the Late Cretaceous Bauru Basin significantly enhances our understanding of neobatrachian early morphology during the Late Cretaceous of South America. [ABSTRACT FROM AUTHOR]

Variation in environmental chemistry affects animal health and demographics. For instance, acidification of aquatic ecosystems (e.g., due to acid rain) can have consequences for organismal fitness. Elevated atmospheric concentrations of CO2, which reacts with water to produce carbonic acid, may affect aquatic animal physiology in multiple ways, including via reductions in pH. Such impacts have been assessed to a large extent in marine systems. Similar effects are also likely occurring in freshwater ecosystems but are relatively understudied. The goal of this project was to determine how changes in pH and CO2 concentrations influence traits and survival of animals in freshwater systems, using larval American Bullfrogs (Lithobates catesbeianus (also known as Rana catesbeiana) [Shaw, 1802]) as a model. We hypothesized that elevated CO2 concentrations and reduced pH negatively affect larval frog immune function, growth, and survival, which we tested in a laboratory aquarium experiment. Over the 27-d experiment, tadpoles were exposed to 4 treatments: 1) near-neutral pH and no gas addition (mean ± SE pH = 7.17 ± 0.05), 2) CO2 gas sparged into aquariums (pH = 5.32 ± 0.04), 3) acidified water without gas addition (pH = 6.29 ± 0.08), and 4) ambient air sparged into aquariums (control for effects of gas addition) at near-neutral pH (pH = 7.46 ± 0.03). We measured tadpole innate immune response, growth, and survival. Results from the experiment partially supported our hypothesis, with lower immune function in tadpoles exposed to acidified water or elevated CO2 compared with the control treatments and lower final mass and survival under elevated CO2. These findings motivate additional research on pH and CO2 effects on freshwater animals and suggest that increased environmental acidity and elevated CO2 can lead to negative impacts, which could contribute to reductions in wildlife health and population declines in light of ongoing environmental changes. [ABSTRACT FROM AUTHOR]

The Pliocene lacustrine infill of Camp dels Ninots maar (Girona, Spain) hosts an exceptional record of complete articulated skeletons. Here we present the taphonomical description of 22 fossil water frogs recovered from the Pit 7/8 of Can Argilera Sector. Description of their skeletal taphonomy is done on the basis of their distribution, completeness, articulation and limb position, and by establishing comparisons with the late Miocene site of Libros (Spain). Microscopic examination shows no evidence of digestion and absence of weathering. Mass mortality or any environmental stress-induced factors cannot be ruled out, but natural death seems to be the most probable. Limited time of decay prior burial seems to be the main pattern explaining the relatively high degree of articulation and completeness. Floatation is not to be disregard for some more (proximally) disarticulated specimens. Taphonomical patterns document two types of sub-environments inside a cool and deep lake, suggesting a more complex depositional scenario for Camp dels Ninots than the ones described in others similar Konservat-Lagerstätten. [ABSTRACT FROM AUTHOR]

We revise the systematics of the ranid frogs of the genus Hylarana occurring on Halmahera Island, Northern Moluccas of eastern Indonesia based on molecular and morphological data. Our results show that two distinct species each being nested within two distinct clades (hereafter papua clade and celebensis clade) exist on the island. One corresponds to H. moluccana (celebensis clade) and the other one to an unnamed species (papua clade) that we describe herein. The new species is genetically distinct from all congeners of the papua clade by p distances ranging from 6.9% to 11.5% on the 16S rRNA gene. Morphologically, the new species can be distinguished from all congeners by having the following combination of characteristics: A large species with adult males reaching a maximum snout-to-vent length (SVL) 67.3 mm; vomerine teeth in two oblique rows with narrow interodontophore distance; snout rounded dorsally; dorsum with few scattered cone-shaped tubercles that are black with white tips; distinct skin folds (ridges) on the dorsal side of the thigh coinciding with dark brown cross bars; a marbled pattern on the ventral side of thigh and yellowish groin. Here we provide a redescription for H. moluccana based on its lectotype from Ternate. We also provide new occurrence records for H. daemeli, H. volkerjane, and H. arfaki from the western part of mainland Papua. Furthermore, we demonstrated that H. celebensis harbors multiple mtDNA lineages suggestive of cryptic diversity within the celebensis clade. The occurrence of two distinct species from Halmahera calls for further research on the biogeographic history of Hylarana in Northern Moluccas. [ABSTRACT FROM AUTHOR]

Despite acoustic signals playing a fundamental role on animal behavior and reproduction, our understanding of the mechanisms driving their evolution is still scarce. Due to the high cost of signaling, several adaptive bioacoustics hypotheses have been proposed to explain call design. While Acoustic Adaptation Hypothesis (AAH) postulates the habitat influence on shaping acoustic signals, Morphological Adaptation Hypothesis (MAH) emphasizes the constraints that animal structure imposes to their calls. Yet, when testing those hypotheses, phylogenetic comparative methods have been scarcely applied so far. Here we evaluated the AAH and MAH in 163 anurans (i.e., Brazilian species of the family Hylidae), based on a broad review of the dominant frequency of their advertisement calls. Comparative methods revealed a negative relationship between dominant frequency and body size, supporting the MAH. AAH was partly rejected, as vegetation density, habitat type and calling microhabitat did not affect species' dominant frequency. However, species calling from higher perches had higher dominant frequencies, partially supporting habitat effect on call features. Our results not only highlight the role of morphology on shaping Hylidae call design, but also arise questions about scale effect, behavioral strategies and other sound propagation characteristics while testing AAH in frogs. [ABSTRACT FROM AUTHOR]

Arizona toad (Anaxyrus microscaphus) is a stream‐breeding bufonid of conservation concern in Arizona, New Mexico, Utah, and Nevada. We determined the occupancy and habitat use of the Arizona toad throughout its range. We surveyed 500‐m reaches along perennial and intermittent streams during the summers of 2021 and 2022 (n = 232) in Arizona. We recorded the presence of all toad life stages, focusing on larval stages. We related toad occupancy to broadscale environmental variables, including measures of bioclimate, habitat heterogeneity, solar radiation, and topography. We collected fine‐scale variables to summarize vegetation cover and substrate within plots (n = 53). We applied multiple occupancy models. Single‐species model results found low toad occupancy with high detection. Two principal component analyses (PCA) were run on broadscale and fine‐scale variables to reduce the number of variables included in the models. Toad occupancy was best predicted by top models with bioclimatic components; occupancy decreases with extremely hot temperatures and less precipitation. A logistic regression related toad presence to fine‐scale components with top models describing riparian complexity and algae. Arizona toads were selected for areas with foliar canopy cover, shallow water, algae cover, and pebble substrates. Arizona toad is an uncommon species and maintaining riparian forests of complex habitats with shallow and side‐channel flow will be important for toad conservation. Implications of less water cause riparian habitat to dry, which ultimately harms aquatic life. [ABSTRACT FROM AUTHOR]

Abstract We here describe abundant new fossil material of amphibians and reptiles from different late Neogene localities of northern Greece: the Early Pliocene (MN 14) of Spilia 0, Spilia 1, and Spilia 2; the Early Pliocene (MN 15) of Spilia 3, Spilia 4, Spilia 5, and Vevi; and the Late Miocene or Pliocene of Chalicorrema and Rema Marmara. These new late Neogene herpetofaunas are highly diverse, documenting a considerably rich herpetofauna allowing the identification of at least two salamander, seven frog, two turtle, seven lizard, and eight snake taxa. Salamanders are represented by the salamandrid genera Ommatotriton and Ichthyosaura. Frogs are represented by the bombinatorid Bombina, the discoglossids Latonia cf. ragei and Latonia sp., the pelobatid Pelobates aff. praefuscus and Pelobates sp., the ranids Pelophylax and Rana cf. dalmatina, the hylid Hyla gr. arborea, and the bufonid Bufotes gr. viridis. Turtles are represented by the emydid Emys and an indeterminate geoemydid. Lizards are represented by the scincid Ophiomorus, two lacertids (one of which potentially pertaining to Lacerta), amphisbaenians, agamids, the anguid Pseudopus, and a potential varanid. Snakes are represented by the erycid Eryx, the natricid Natrix aff. rudabanyaensis, a small-sized elapid, an “Oriental viper”, the colubriforms Periergophis and Paraxenophis, as well as two further distinct but still indeterminate morphotypes of colubriforms. For the material from Spilia tentatively referred to Ommatotriton, this is only the third occurrence in the fossil record globally. The new material of Ichthyosaura and Bombina mark the first documentation of these genera in the Greek fossil record. Abundant cranial and postcranial material from Spilia is tentatively referred to Latonia ragei, a taxon previously known from the Early Miocene of Western Europe. The new record of Pelobates represents the oldest documented occurrences of the genus in the Greek fossil record. Interestingly, the Pelobates from Spilia bears much resemblance to an extinct taxon, Pelobates aff. praefuscus, which is otherwise known from the Late Miocene of the Caucasus, and not to the extant species that currently inhabits the area. The identification of Pelophylax and Rana adds to the rather poor Neogene record of ranids from Greece. Particularly for the case of Rana cf. dalmatina from Spilia 4, this corresponds to the only documented occurrence of this extant taxon in the Greek fossil record. Similarly, the identification of Hyla gr. arborea in Spilia 1, Spilia 3, and Spilia 4, marks only the third documented occurrence of this genus in the Greek fossil record. The Bufotes material from Spilia 1, Spilia 3, and Spilia 4 represents the first documented fossil occurrence of the extant Bufotes viridis complex in Greece. The material of Emys gr. orbicularis from Vevi marks the only known pre-Quaternary record of the genus in Greece and one of the only few Neogene members of the genus known from Europe. The scincid Ophiomorus is identified in Spilia 4, known from several cranial and postcranial remains, well outside the extant range of the genus. Practically, the Spilia Ophiomorus is only the fourth known fossil occurrence of this extant genus globally and also represents one of its oldest known occurrences. Material from Spilia 1 and Spilia 3 is tentatively referred to cf. Lacerta sp., and this would mark the first known occurrence of this emblematic extant genus in the Greek fossil record, denoting the presence of the genus since at least the Early Pliocene. The new amphisbaenian specimens from Spilia 4 add to the recently described single vertebra from the same locality, and represent the youngest occurrence of amphisbaenians from continental Eastern Europe. The new agamid material from Vevi and Chalicorrema add substantially to the record of this group, which was in Greece so far known exclusively from the latest Miocene/earliest Pliocene of Maramena. A similarly important addition is the record of Pseudopus from Spilia 4, as this genus had been known in the Greek fossil record only from a very few localities. The potential varanid from Spilia represents one of the few Pliocene occurrences of this group in Europe. We identify Natrix aff. rudabanyaensis among the material from Spilia 0, Spilia 4, and Vevi, adding to the previously known record of this taxon from Maramena, however, its precise species level assignment should await a revision of Neogene European Natrix spp. The find of a small elapid from Spilia 4 represents the youngest occurrence of a coral snake from Europe, extending their statigraphic range up to the Early Pliocene (MN 14). Periergophis and Paraxenophis, two bizarre snakes, so far exclusively known from their type locality in Maramena, could be also present here, even if tentatively identified. Most notably, the new material from these localities comprises forms that are now extinct (e.g., Periergophis and Paraxenophis) or extirpated from Europe (e.g., Latonia, Varanidae, Elapidae) but at the same time also loudly attests the emergence of the extant genera that dominate the extant herpetofaunas of Greece (Ichthyosaura, Bombina, Pelobates, Pelophylax, Rana, Hyla, Bufotes, Emys, Ophiomorus, Lacerta, Pseudopus, Eryx, and Natrix), for some of which their fossil record is documented here for the first time in the area.

Many anuran survival strategies involve hydric regulation, and reproduction is not different. The aquaporin (AQP) family plays an important role in water transport and regulation in many tissues, including the male gonad. The testes undergo various stages of change during the reproductive cycle, and water balance is an important factor for ensuring reproductive success. Considering the relevance of water control in testicular development in anurans and the lack of research regarding the tissue localization of AQP in the male gonad, the present study investigated the expression of three AQPs (1, 2, and 9) in the testis of the neotropical anuran species Leptodactylus podicipinus during two different periods of the reproductive cycle (reproductive and non-reproductive). AQP1 and 2 immunoreactions were found in early germ cells, spermatozoa, Leydig cells, and Sertoli cells, which were more frequently expressed within the reproductive period. AQP1 was also found in the testicular blood vessels. AQP9 was identified predominantly in the epithelium of the intratesticular ducts of reproductive-period individuals. This study presents, for the first time, the localization of AQP1, AQP2, and AQP9 in the testes of an anuran species and the differences in their location during two distinct periods of the reproductive cycle.

Anurans are widely diversified in South Africa, with more than 150 recognised species across the country. However, most the known fossil records of anurans are concentrated in the southern part of South Africa, within the rich Pliocene site of Langebaanweg. Isolated anuran elements have been recovered in the Pliocene deposits of the Cradle of Humankind, but none from the multi-localities site of Bolt's Farm (Plio-Pleistocene). A small block containing an articulated anuran specimen was recently discovered from the Milo A site from Bolt's Farm. We analysed this specimen using CT-scanning to describe its osteology. Surprisingly, the cavity housing the skeleton took the shape of the body of the individual, revealing a small sized individual with a triangular-shaped head. The preserved skeletal elements (around 50% of the skeleton) shows clear synapomorphies of the Ranoidea. A comparison between our specimen and members of all South African ranoid families allow us to highlight numerous osteological similarities between our specimen and taxa of the Pyxicephalidae, leading to a putative attribution to this large African family. In addition, the position of the body is identical to the position of a dormant pyxicephalid, suggesting that our specimen died during a dormancy period, in the dry season. This supports the current paleoenvironment reconstruction, an open savannah with marked seasonality. [ABSTRACT FROM AUTHOR]

The Chinese horned toads, Boulenophrys boettgeri (Boulenger, 1899) and Boulenophrys kuatunensis (Pope, 1929), are two captivating species within the family Megophryidae, which inhabit the mountainous streams in the Eastern of China. In this study, two new complete mitochondrial genomes of B. boettgeri and B. kuatunensis were sequenced, assembled, and annotated using next-generation sequencing. The length of mitochondrial genomes of B. boettgeri and B. kuatunensis was 16,597 and 17,921 bp, respectively, with both containing 13 protein coding genes, 22 tRNA genes, two rRNA genes, and one putative control region. Phylogenetic relationships based on protein-coding mitochondrial genes showed that the two Boulenophrys species formed a cluster with other Boulenophrys species. The two new sequences provide valuable insights into the mitochondrial genomes of these two species, offering important data for understanding the phylogenetic relationships of the genus Boulenophrys.

This article provides a detailed description of the tadpole of the Hyloxalus nexipus frog species, focusing on its geographic variation and morphological characteristics. The researchers collected specimens from Ecuador and Peru and examined their coloration and measurements. The document emphasizes the importance of studying tadpoles in understanding anuran species. It also discusses the morphology and characteristics of tadpoles belonging to the Hyloxalus genus of poison dart frogs, noting specific differences in the upper jaw sheath and the position of the upper fin in Hyloxalus nexipus tadpoles. The information is based on detailed observations of single specimens in different developmental stages and references other relevant studies on tadpole morphology and taxonomy. [Extracted from the article]

Anurans have several characteristics in their acoustic communication that distinguish them. These characteristics are influenced by body-related, environmental and social variables. However, the complexity of anuran repertoire and the effect of such variables on it are still understudied. Dendropsophus minutus is a Neotropical treefrog that has a wide repertoire composed of three notes, grouped in at least 71 unique combinations. To quantify complexity, we used the entropy measurement, since it measures the randomness of a sequence. Therefore, we could test if repertoire complexity in D. minutus is related with body condition, social context, and environmental variables. We recorded vocalisations of 80 males in three sites and found 44 unique note combinations not described before, increasing the species' repertoire to 115 combinations. We observed that the species has near maximum entropy for note frequency, but a low entropy for note sequencies, showing a clear a bias for some note combinations. We found a positive relationship between repertoire complexity and air temperature. Thus, based on our results, the complexity of this species' repertoire is an additional trait influenced by climate, and should be considered in future studies. [ABSTRACT FROM AUTHOR]

A group of fanged frogs from Southeast and East Asia has long been considered a single widespread species Limnonectes kuhlii, but occurrence in this group of many cryptic species has recently been demonstrated mainly in the continent through molecular phylogenetic analyses. This led to similar analyses of populations from other parts of the known range, and phylogenetic relationships inferred for frogs from the island of Borneo through mitochondrial and nuclear DNA resulted in the presence of nearly 20 distinct lineages. We studied morphological variation in 13 of these lineages from the Malaysian part and confirmed their taxonomically distinct statuses. We applied existing names to three of them, L. conspicillatus, L. kong, and L. mocquardi, and described 10 remaining ones as new species. [ABSTRACT FROM AUTHOR]

By selecting appropriate microhabitats, animals gain various benefits. For amphibians, which are ectothermic, appropriate microhabitat selection is directly related to their survival. This study aims to characterize the microhabitat type selected by Bufo gargarizans in South Korea, which has not yet been examined, using radiotelemetry. We analyzed the percent cover of different microhabitat features at sites where B. gargarizans was found. The microhabitat was categorized into eight types: stacked dry leaves litter or hay, grass, naked field, stones/pebbles, fallen branches, alive or dead trees/shrubs, wetland, and other. We collected a total of 60 location data, all of which had closed cover. From these, nine hibernation sites and six post-breeding dormancy sites were identified. Dry leaf litter was found to be the most frequently selected microhabitat type. We also found significant differences in microhabitat type between the hibernation period and the post-breeding dormancy period. We considered that these differences can be explained by the ecological characteristics of B. gargarizans. [ABSTRACT FROM AUTHOR]

The genus Ozolaimus is characterised by presenting a dorsoventrally elongated mouth with two lateral lips, a very long oesophagus consisting of anterior portion strong and short, with a fusiform fold, and a thin posterior portion ending in a distinct bulb, an anteriorly dilated intestine, and absent lateral wings. Between February 2014 and September 2016, 11 specimens of the anuran Corythomantis greeningi were collected manually at the Ecological Station of Aiuaba, Ceará State, Brazil. After analysis, nine specimens of Ozolaimus cirratus infecting the large intestine of the referred specimen were recorded. Knowledge is still scarce about the ecological dynamics of pharyngodonid parasites and their parasitehost relationships; thus, this work is the first to record members of the genus Ozolaimus infecting the casqueheaded tree frog Corythomantis greeningi from the Caatinga biome. Previously, the only registered hosts of Ozalaimus parasites were iguanid lizards. [ABSTRACT FROM AUTHOR]

Mutualistic and similar ecological associations between tarantulas (Mygalomorphae: Theraphosidae) and other animals are reviewed. Such associations are found to occur in at least nine theraphosid subfamilies. We present 63 new cases of theraphosid–anuran associations from 10 countries, documenting these interactions for the first time in Brazil, Chile, the Dominican Republic, and the Philippines. These findings are the first documentation of such associations for 13 theraphosid and 20 anuran taxa. Additionally, we report, for the first time, associations potentially of mutualistic nature between tarantulas and snakes, whip spiders, and harvestmen. Furthermore, we provide new reports of associations with ants and termites. While some of these interactions appear to be merely tolerated cohabitations, those involving anurans and ants seem to be more prevalent and complex, clearly offering benefits for both organisms. Additionally, based on multiple observations and field experiments, we propose a new hypothesis regarding the evolution of hirsuteness in theraphosids as a defensive strategy against predatory ants. This hypothesis supports previous findings that suggest a similar function for urticating setae incorporated into egg sacs and moulting mats. We further document a unique escape strategy against ants in New World arboreal theraphosids. Finally, the possibility of a chemical defence mechanism through specialised epidermal glands in theraphosids is briefly discussed. [ABSTRACT FROM AUTHOR]

Olfaction is the oldest sense in the animal kingdom. It is used during a multitude of behaviours, such as the encounter of food, the detection of predators, the recognition of habitat‐related cues or the communication with conspecifics. While the use of olfaction and chemical communication has been studied widely in some animals, it is barely known in others. Anurans (frogs and toads), for example, are well known to use acoustic and visual senses, but their chemical sense is still largely understudied. Studies concerning the chemical sense in anurans have been mostly based on the use of semiochemicals in juvenile stages, while the information on adult anurans remains limited. In this study, we analysed the behavioural response of the Neotropical poison frog Ranitomeya sirensis (Sira poison frog, Dendrobatidae) when presented with the odours of prey, novel/prey‐luring fruit, habitat, conspecific faeces and heterospecifics. For this, we offered each of the odours by placing them into one of two testing tubes fixed in an arena, with the other tube left empty as a control. We then measured the time the frogs spent in the vicinity of the odour versus the control tube and calculated a response index. While the frogs did not show a significant avoidance or attraction towards most of the tested odours, they showed a strong response towards the heterospecific odour, which was significantly avoided. This is the first evidence of a poison dart frog responding towards the odours of adult heterospecific frogs. We consider potential reasons for this strong negative reaction, such as the interspecific competition avoidance hypothesis, and discuss our results in the context of other animal species being deterred or attracted by heterospecific chemical cues. [ABSTRACT FROM AUTHOR]

Simple Summary: Head and neck cancers are aggressive and challenging to treat due to the severe side effects and toxicity of current treatments. Bufalin, a natural compound from the Chinese toad, has shown promise in fighting various cancers but has not been thoroughly studied for head and neck cancers. Our research aims to explore how bufalin works against these specific cancer cells. By using different techniques, we discovered that bufalin could reduce cancer cell growth, induce cell death, and enhance the body's immune response against tumors. These findings suggest that bufalin could become a new, effective treatment option with potentially fewer side effects for patients with head and neck cancers. This research could pave the way for developing better therapies and improving outcomes for patients facing this difficult disease. Bufalin, a cardiotonic steroid derived from the Chinese toad (Bufo gargarizans), has demonstrated potent anticancer properties across various cancer types, positioning it as a promising therapeutic candidate. However, comprehensive mechanistic studies specific to head and neck cancers have been lacking. Our study aimed to bridge this gap by investigating bufalin's mechanisms of action in head and neck cancer cells. Using several methods, such as Western blotting, immunofluorescence, and flow cytometry, we observed bufalin's dose-dependent reduction in cell viability, disruption of cell membrane integrity, and inhibition of colony formation in both HPV-positive and HPV-negative cell lines. Bufalin induces apoptosis through the modulation of apoptosis-related proteins, mitochondrial function, and reactive oxygen species production. It also arrests the cell cycle at the G2/M phase and attenuates cell migration while affecting epithelial–mesenchymal transition markers and targeting pivotal signaling pathways, including Wnt/β-catenin, EGFR, and NF-κB. Additionally, bufalin exerted immunomodulatory effects by polarizing macrophages toward the M1 phenotype, bolstering antitumor immune responses. These findings underscore bufalin's potential as a multifaceted therapeutic agent against head and neck cancers, targeting essential pathways involved in proliferation, apoptosis, cell cycle regulation, metastasis, and immune modulation. Further research is warranted to validate these mechanisms and optimize bufalin's clinical application. [ABSTRACT FROM AUTHOR]

Our aim was to evaluate whether the richness and composition of anurans responded to the time of forest regeneration via secondary succession. We sampled the anuran community in a mosaic of areas at three different stages of secondary succession in the Atlantic Forest, southern Brazil. The anurans were collected from nine lentic ponds and from their margins up to a 50 m radius. The late secondary forest sheltered the higher species richness, followed by the primary forest. The spatial variation in species richness was related to the forest succession stage and predominance of arboreal vegetation on the pond edge. The species composition changed throughout the succession stages, regardless of the distance among areas. Along the gradient of forest succession, environmental changes have driven species distribution, limiting the occurrence of forest species and favoring the colonization of areas at the early succession stage by opportunist species. We could observe that the secondary forest succession was a determining factor in the anuran community structure, and with the advancement of the secondary succession, both richness and composition were partly restored. Thus, the conservation of secondary forests might be an efficient strategy to preserve the biodiversity in areas of the Atlantic Forest. [ABSTRACT FROM AUTHOR]

The treefrog Boana exastis was tentatively included in B. faber group based on its morphological similarity to B. lundii and B. pardalis. This species was only recently included in a molecular phylogeny, confirming its placement in this group; however, its phylogenetic relationships have been poorly explored. Herein, we describe the larval external morphology, buccopharyngeal cavity, and skeleton of B. exastis, and assess its phylogenetic placement and genetic similarity between disjunct populations. Additionally, we describe the larval skeleton of the two closely related species, B. lundii and B. pardalis. The larval morphology of B. exastis is congruent with the other Boana species, reinforcing a high larval similarity across species of the B. faber group. The three species showed differences in color and in rows of marginal papillae. Comparing the chondrocranium of the three species, we found that B. exastis is more similar to B. pardalis than to B. lundii, contrary to what has been previously proposed, based on acoustic data. Phylogenetically, B. exastis was found to be more related to B. pardalis than to B. lundii. Despite presenting a disjunct distribution, the populations of Boana exastis show a very low mitochondrial genetic divergence, indicating that they are the same taxon. [ABSTRACT FROM AUTHOR]

Despite the great diversity of Brazilian anuran species, there are still many knowledge gaps about the acoustic communication of these animals. Among the species, those classified as 'Data Deficient' have the greatest gaps in knowledge on their behavior. This is the case of Boana ericae, a species belonging to the Boana pulchella group, endemic to the Chapada dos Veadeiros National Park region, in the northeast of the state of Goiás, Central Brazil. Three distinct call types (A, B, and C) are currently known for B. ericae, with the type A call associated with attracting reproductive partners and the type C call presenting a territorial function. We recorded the vocalizations of 10 individuals of this species and found the presence of vocalizations composing three new note types (D, E, and F). Our results indicate that air temperature and body condition influenced the acoustic parameters of the advertisement and aggressive calls of this species. We also observed that some acoustic parameters of the advertisement calls can be used for individual recognition for showing greater variation among individuals than intra-individually. Our results add new information regarding the vocal repertoire in this species, expanding their known intra-individual classification of the acoustic parameters. [ABSTRACT FROM AUTHOR]

Reproductive strategies are one of the more fascinating aspects of Anuran biology and are likely affected by species habitat use and availability of reproductive sites. The Cerrado endemic Pithecopus oreades is a habitat specialist that reproduces in seasonal high-altitude rocky streams in Central Brazil. Herein, we describe its reproductive behavior based on observations made during two consecutive reproductive seasons in a high-altitude stream located in an open field area in Central Brazil. The reproductive activity of P. oreades occurs during the rainy season, from the very first rains, and lasts about 3 months. The species is nocturnal, showing a vocalization peak between 20:00 h and 21:00 h. Its vocalization activity was related to total precipitation. The nests, composed by only one folded leaf, are placed on shrubs along streams. The nests, which hang over the stream pools, contain approximately 30 eggs that last about 13 days of incubation, producing about 25 tadpoles per spawning. Males are territorial, remaining in the same places for more than 60 days, defending them through vocalizations and eventual physical combats. Males with a higher body condition usually stay longer in the same territory. We also recorded males displaying satellite behavior. [ABSTRACT FROM AUTHOR]

In addition to the type locality (the summit of Aprada-tepui, Bolívar State of Venezuela), the distribution of the egg-brooding frog Stefania satelles was long thought to include several isolated tabletop mountain (tepui) summits surrounding the large Chimantá Massif in Bolívar State (hence the Latin name "satelles"). However, multilocus molecular phylogenetic analyses have revealed that this taxon includes several undescribed morphologically cryptic species, and that S. satelles should be restricted to its type locality. Two tepui-summit species confused under that name in the literature remain to be named, and the present paper aims at describing these populations previously referred to as Stefania sp. 3 and S. sp. 5. Stefania sp. 3 is only known from the small summit of Angasima-tepui, while S. sp. 5 is only reported from the small summit of Upuigma-tepui, both mountains being located south of the Chimantá Massif. These new, phylogenetically distinct species are described based on external morphology and osteology and in comparison to close relatives in the S. ginesi clade, which consists exclusively of tepui summit species. Both new species have highly restricted geographic ranges (less than 3 km2) and should be listed as Critically Endangered according to IUCN criteria. [ABSTRACT FROM AUTHOR]

Background: Kurixalus lenquanensis Yu, Wang, Hou, Rao and Yang, 2017 was originally described, based on 14 adult male specimens from Lengquan Village, Mengzi, Yunnan, China. So far, this species is known only from south-eastern Yunnan and information on females of this species is not available. During the field surveys in 2023, two Kurixalus specimens (one female and one male) were collected from central eastern Yunnan (Shilin, Kunming, Yunnan, China). These two specimens were confirmed to be K. lenquanensis by molecular phylogenetic analyses, based on 16S rRNA sequences. New information: A female specimen of K. lenquanensis is described for the first time and morphological variation amongst populations of this species is provided. The diagnosis and distribution of this species are updated. [ABSTRACT FROM AUTHOR]

Centrolenidae is a Neotropical family widely distributed in Central and South America, with its species richness concentrated in the tropical Andes. Several taxonomic problems have been identified within this family, mostly related to species with broad geographic distributions. In this study, we assessed and redefined the species boundaries of the Centrolene buckleyi species complex, and formally described two new species from the Andes of Ecuador. These new taxa are recognized by a combination of morphometric, osteological, acoustic, and genetic data. Following IUCN criteria, we propose that the two new species should to be considered as Endangered (EN), mainly because of their small distributions and habitat loss. The C. buckleyi complex provides insights into the biogeography of closely related Andean species. As in other glassfrogs, speciation in Centrolene seems to be mediated by the linearity of the Andes, where gene flow can be restricted by topography and, also, local extinctions. [ABSTRACT FROM AUTHOR]

The Chinese horned toads, Boulenophrys boettgeri (Boulenger, 1899) and Boulenophrys kuatunensis (Pope, 1929), are two captivating species within the family Megophryidae, which inhabit the mountainous streams in the Eastern of China. In this study, two new complete mitochondrial genomes of B. boettgeri and B. kuatunensis were sequenced, assembled, and annotated using next-generation sequencing. The length of mitochondrial genomes of B. boettgeri and B. kuatunensis was 16,597 and 17,921 bp, respectively, with both containing 13 protein coding genes, 22 tRNA genes, two rRNA genes, and one putative control region. Phylogenetic relationships based on protein-coding mitochondrial genes showed that the two Boulenophrys species formed a cluster with other Boulenophrys species. The two new sequences provide valuable insights into the mitochondrial genomes of these two species, offering important data for understanding the phylogenetic relationships of the genus Boulenophrys. [ABSTRACT FROM AUTHOR]

The palaeofauna of the Quaternary is mostly known from the mammals' record, while the herpetofauna is less represented. In the same way, in northeastern Argentina reptile fossils records are scarce, usually represented by preliminary communications. This paper focuses on the study of herpetofauna remains from the Isla El Disparito archaeological site. The faunal materials collected at the site revealed an increase in taxonomic diversity related to the Quaternary herpetofauna in the IED site, with over 50% of the bone remains represented by anurans and at least six recognized squamates taxa. The purpose of this study is to properly identify these new records of herpetofauna remains from northeastern Argentina during the Holocene as well as to provide a dichotomous key of postcranial remains for identifying extant squamates taxa in other Quaternary sites from Argentina. The identified squamate assemblage includes the lizard Ophiodes sp., the snake families Typhlopidae, Dipsadidae, Viperidae and undetermined colubroids, along with anuran bone remains (Anura indet. and ?Hylidae). Additionally, the findings contribute to a better understanding of the herpetological assemblage in Argentina, providing insights into the composition of South American squamates during the Quaternary. [ABSTRACT FROM AUTHOR]

The Late Miocene vertebrate fauna from the Entre Ríos Province, Argentina, comes from two units: the marine Paraná Formation and the Lower Member of Ituzaingó Formation (LMIF). This latter includes a lower conglomerate set, with fine quartz gravel, and clay and chalcedony clasts, and fossil remains, traditionally known as ‘Mesopotamiense’ or ‘Conglomerado osífero’. We present new fossil vertebrate remains from the LMIF at the Puerto Víboras locality (Hernandarias, Entre Ríos Province) including Leptodactylus sp. (Amphibia, Anura), Crocodylia indet. Caimaninae indet. and Paranasuchus gasparinae (Alligatoridae), Chelidae indet. (Testudines, Pleurodira), Chelonoidis sp. (Testudines, Cryptodira), Plohophorus paranensis (Cingulata, Glyptodontidae), and Macraucheniinae indet. (Macraucheniidae, Litopterna). The record of Leptodactylus sp. represents the oldest record of the genus and the first amphibian record for the Neogene of the Entre Ríos Province. The material described herein and assigned to Chelonoidis sp. allows to confirm for the first time the presence of a testudinid in the Late Miocene of the Entre Ríos Province. [ABSTRACT FROM AUTHOR]

Photoreceptor oil droplets (ODs) are spherical organelles placed most commonly within the inner segment of the cone photoreceptors. Comprising neutral lipids, ODs can be either non-pigmented or pigmented and have been considered optically functional in various studies. Among living amphibians, ODs were only reported to occur in frogs and toads (Anura), while they are absent in salamanders and caecilians. Nonetheless, the limited understanding of their taxonomic distribution in anurans impedes a comprehensive assessment of their evolution and relationship with visual ecology. We studied the retinae of 134 anuran species, extending the knowledge of the distribution of ODs to 46 of the 58 currently recognized families, and providing a new perspective on this group that complements the available information from other vertebrates. The occurrence of ODs in anurans shows a strong phylogenetic signal, and our findings revealed that ODs evolved at least six times during the evolutionary history of the group, independently from other vertebrates. Although no evident correlation was found between OD occurrence, adult habits and diel activity, it is inferred that each independent origin involves distinct scenarios in the evolution of ODs concerning photic habits. Furthermore, our results revealed significant differences in the size of the ODs between nocturnal and arrhythmic anurans relative to the length of the cones' outer segment. [ABSTRACT FROM AUTHOR]

Colour signals play pivotal roles in different communication systems, and the evolution of these characters has been associated with behavioural ecology, integumentary production processes and perceptual mechanisms of the species involved. Here, we present the first insight into the molecular and histological basis of skin colour polymorphism within a miniaturized species of pumpkin toadlet, potentially representing the lowest size threshold for colour polytypism in tetrapods. Brachycephalus actaeus exhibits a coloration ranging from cryptic green to conspicuous orange skin, and our findings suggest that colour morphs differ in their capability to be detected by potential predators. We also found that the distribution and abundance of chromatophores are variable in the different colour morphs. The expression pattern of coloration related genes was predominantly associated with melanin synthesis (including dct, edn1, mlana, oca2, pmel, slc24a5, tyrp1 and wnt9a). Up‐regulation of melanin genes in grey, green and brown skin was associated with higher melanophore abundance than in orange skin, where xanthophores predominate. Our findings provide a significant foundation for comparing and understanding the diverse pathways that contribute to the evolution of pigment production in the skin of amphibians. [ABSTRACT FROM AUTHOR]

The distribution of the Coastal Bull Frog, Hoplobatrachus litoralis in Arunachal Pradesh was not certain for lack of any tangible report. The occurrence of this species in this Himalayan state of Arunachal Pradesh is reported herein based on recent collection of three individuals from a swampy area from the Senki Valley of the Itanagar Wildlife Sanctuary, Papum Pare district, Arunachal Pradesh. Brief diagnostic characters are also provided based on the observed individuals. [ABSTRACT FROM AUTHOR]

Urban environments expose wildlife to levels of anthropogenic noise they would not experience in rural areas (e.g., traffic noise), and research suggests that many species adjust their acoustic signals for optimal transmission in urban soundscapes. However, our understanding of anuran (order Anura) responses to noise pollution in urban environments of the southeastern United States is limited, particularly for species that can breed during winter. Our goal was to examine how vocal anuran advertisement call characteristics during winter varied with increasing distance from roadways in bottomland hardwoods of Louisiana, USA. We deployed acoustic recording units at two sites (i.e., rural and urban) perpendicular to Interstate 10 at 200‐, 400‐, and 600‐m intervals (i.e., close, middle, and far) from November 2019 to January 2020. We detected Cajun Chorus Frogs (Pseudacris fouquettei) and Cricket Frogs (Acris spp.) at our rural site, and only detected Cricket Frogs at our urban site. At the rural site, Cajun Chorus Frogs produced longer duration notes at the far location compared to the middle location. At the urban site, Cricket Frogs produced higher dominant frequency calls at the close location compared to the far and middle locations and longer duration notes at the far location compared to the close location. We were unable to account for additional factors in our models (e.g., temperature, noise levels), but our results generally align with previous research. Our study provides baseline data for future research to examine the potential effects of traffic noise on winter advertisement calls in locations with similar environmental conditions and species. [ABSTRACT FROM AUTHOR]