Microhylidae Research Articles

Four in one: An integrative taxonomic revision of the Microhyla berdmorei complex (Amphibia: Anura: Microhylidae) illustrates the tremendous amphibian diversity of Southeast Asia

Abstract Berdmore’s narrow-mouthed frog, Microhyla berdmorei (Blyth, 1856), is the largest member of the genus Microhyla and is distributed all over Southeast Asia, from Northeast India and southern China to Sumatra and Borneo in Indonesia. Here we demonstrate that M. berdmorei represents a complex of four species that are morphologically, acoustically, and genetically distinct from each other, and we implement taxonomic revisions. Phylogenetic analyses of three mitochondrial DNA (hereafter mtDNA, including COI, 12S, and 16S rRNA; 3119 bp) and one nuclear (BDNF; 716 bp) gene sequences are corroborated by phylogenomic analyses of 2700 ddRAD-seq loci (387,270 bp). All support that the M. berdmorei complex, which originates from the early Miocene (ca. 19.7 mya), consists of two clades that we date to the late Miocene (ca. 7.5 mya). The first clade, which regroups populations of large-sized individuals, is distributed in Indo-Burma and includes a lineage from Northeast India, Bangladesh, and Myanmar (M. berdmorei sensu stricto) and a lineage from West Malaysia, Thailand, Laos, Cambodia, and Vietnam (for which we propose to resurrect the species M. malcolmi Cochran, 1927). The second clade, which regroups populations of small-sized individuals, occurs in Sundaland and also includes two lineages for which we provide taxonomic descriptions on species rank. The first new species is widely distributed from Peninsular Malaysia to the islands of Borneo and Sumatra (described herein as M. sundaicasp. nov.), while the second one is restricted to the Malay Peninsula and occurs in extreme southern Thailand and adjacent Malaysia (M. peninsularissp. nov.). We further provide evidence for the synonymy of Callula natatrix Cope, 1867 with M. berdmorei sensu stricto, and M. fowleri Taylor, 1934 with M. malcolmi. Our study illustrates the high diversity of Southeast Asian amphibians, especially in the genus Microhyla, which presently totals 54 species.

Species composition and conservation of amphibians in Central Panay Mountain Range, Antique, Philippines

Abstract. Flores GMA, Torres AG, Flores ABA, Jakosalem PGC, Guihawan JQ, Roa-Quiaoit HA. 2024. Species composition and conservation of amphibians in Central Panay Mountain Range, Antique, Philippines. Biodiversitas 25: 1797-1808. Assessing amphibian species composition and conservation status in Central Panay Mountain Range (CPMR), the largest contiguous forest in West Visayas in central Philippines, provides relevant and updated information on the status and conservation needs of the amphibians. Opportunistic, visual encounter and acoustic surveys were employed across diverse habitats-lowland and lower montane forests, streams, and grasslands. A total of 11 amphibian species from six families were documented, with notable findings including endemic species such as Rough-backed forest frog Platymantis corrugatus Duméril 1853, Dumeril’s wrinkled ground frog Platymantis dorsalis Duméril 1853, and Philippine narrow-mouth toad Kaloula conjuncta negrosensis Taylor 1922, as well as threatened species Panay forest frog Platymantis panayensis Brown, Brown and Alcala 1997, which is endemic to Panay Island. The P. dorsalis emerged as the most abundant, with 127 individuals recorded. Furthermore, two new distribution records of amphibians, narrow-mouth toad Kaloula sp. and panther flying frog Rhacophorus pardalis Günther 1858 were identified, potentially representing previously undocumented species endemic to the Philippines. The survey also revealed local threats posing significant risks to amphibian populations in the area. Several conservation measures have been proposed to protect amphibians and their habitats within CPMR. Given the area's rich biodiversity and ecological integrity, efforts are currently being implemented to establish CPMR as a nationally protected area, and this study contributes to this initiative by providing baseline data on amphibian diversity, underscoring the role of amphibians as ecological indicators of ecosystem health.

New record and dietary ecology of an endangered amphibian species, Micryletta nigromaculata Poyarkov, Nguyen, Duong, Gorin & Yang, 2018, from Vietnam

The Black-spotted Paddy Frog (Micryletta nigromaculata) was recently discovered from northern Vietnam. Due to its restricted distribution in limestone karst forests and habitat degradation, the endemic species has been listed as “Endangered” in the IUCN Red List. However, knowledge about the natural history of this species is scarce, including data on its dietary ecology. Recent field surveys revealed new populations of M. nigromaculata occurring in Son La Province, northwestern Vietnam based on morphological analysis. Using the stomach-flushing method, we analyzed stomach contents of 45 individuals (21 males and 24 females) from a total of 52 captured frogs because stomachs of six males and one female (13.5%) were empty. The food spectrum of M. nigromaculata comprises 12 types with a total of 691 prey items (687 invertebrate items and four unidentified items), belonging to six insect orders, larvae and Araneae. Similar to other species of the family Microhylidae, M. nigromaculata is also identified as an ant (Formicidae) – termite (Rhinotermitidae) eating specialist with distinctly higher percentages of occurrence frequency (F = 65 %), number of prey items (N = 80 %), and importance (Ix = 75 %) than those of remaining types. The Simpson diversity index of 0.939 shows a high abundance of food prey in the wild, and the Evenness index of 0.536 suggests biased consumption of feeding selection for M. nigromaculata.

Populating a Continent: Phylogenomics Reveal the Timing of Australian Frog Diversification.

The Australian continent's size and isolation make it an ideal place for studying the accumulation and evolution of biodiversity. Long separated from the ancient supercontinent Gondwana, most of Australia's plants and animals are unique and endemic, including the continent's frogs. Australian frogs comprise a remarkable ecological and morphological diversity categorized into a small number of distantly related radiations. We present a phylogenomic hypothesis based on an exon-capture dataset that spans the main clades of Australian myobatrachoid, pelodryadid hyloid, and microhylid frogs. Our time-calibrated phylogenomic-scale phylogeny identifies great disparity in the relative ages of these groups that vary from Gondwanan relics to recent immigrants from Asia and include arguably the continent's oldest living vertebrate radiation. This age stratification provides insight into the colonization of, and diversification on, the Australian continent through deep time, during periods of dramatic climatic and community changes. Contemporary Australian frog diversity highlights the adaptive capacity of anurans, particularly in response to heat and aridity, and explains why they are one of the continent's most visible faunas. [Anuran; adaptive radiation; Gondwana; phylogenetics].

A Pore Forming Toxin-like Protein Derived from Chinese Red Belly Toad Bombina maxima Triggers the Pyroptosis of Hippomal Neural Cells and Impairs the Cognitive Ability of Mice.

Toxin-like proteins and peptides of skin secretions from amphibians play important physiological and pathological roles in amphibians. βγ-CAT is a Chinese red-belly toad-derived pore-forming toxin-like protein complex that consists of aerolysin domain, crystalline domain, and trefoil factor domain and induces various toxic effects via its membrane perforation process, including membrane binding, oligomerization, and endocytosis. Here, we observed the death of mouse hippocampal neuronal cells induced by βγ-CAT at a concentration of 5 nM. Subsequent studies showed that the death of hippocampal neuronal cells was accompanied by the activation of Gasdermin E and caspase-1, suggesting that βγ-CAT induces the pyroptosis of hippocampal neuronal cells. Further molecular mechanism studies revealed that the pyroptosis induced by βγ-CAT is dependent on the oligomerization and endocytosis of βγ-CAT. It is well known that the damage of hippocampal neuronal cells leads to the cognitive attenuation of animals. The impaired cognitive ability of mice was observed after intraperitoneal injection with 10 μg/kg βγ-CAT in a water maze assay. Taken together, these findings reveal a previously unknown toxicological function of a vertebrate-derived pore-forming toxin-like protein in the nerve system, which triggers the pyroptosis of hippocampal neuronal cells, ultimately leading to hippocampal cognitive attenuation.

Another giant species of the microhylid frog genus Cophixalus Boettger, 1892 from the mountains of Papua New Guinea and first records of procoracoids in the genus

A new arboreal species of the microhylid genus Cophixalus Boettger, 1892 is described from montane rainforest on Papua New Guinea’s central cordillera. With a male SUL exceeding 44.0 mm, the new species is among the largest members of the genus; the only other Papuan species known to reach this size is C. riparius Zweifel, 1962. The new species differs from C. riparius in a small number of mensural characters and by its distinct advertisement call, a single explosive ‘bark’ uttered singly or in rapid series. In contrast, calls of C. riparius recorded near the type locality are a series of drawn out, rasping croaks. Calls of the two species are analysed and compared. The two species also appear to have different ecologies, with the new species found only high in trees, while C. riparius is often encountered in vegetation on or near the forest floor. Examination of osteological features revealed the presence of cartilaginous procoracoids in both species, representing the first records of procoracoids in the speciose genus Cophixalus. Lack of procoracoids is traditionally considered an important diagnostic character for defining Cophixalus but both species also lack clavicles, a character considered diagnostic for Cophixalus and a key feature distinguishing the genus from the closely related Oreophryne Boettger, 1895. Because preliminary published genetic data indicate that they are nested within Cophixalus, we retain both species in that genus until a comprehensive molecular phylogeny of Cophixalus and related genera, particularly Oreophryne, is completed.

Tadpole morphology of Jerdon’s Narrow-mouthed Frog Uperodon montanus (Jerdon, 1853) with a range and elevation extension report from Western Ghats, India

The study discusses about the new data on larval description, morphological features, larval ecology of stage 25–40 of the Jerdon’s Narrow-mouthed Frog Uperodon montanus (Jerdon, 1853). Tadpoles were identified up to family and genus level based on the historical literature and the species level confirmation was done with molecular studies. We also present a new northern limit record of this species from the Pushpagiri hill ranges in Karnataka (12.669 N, 75.717 E) and a new highest elevation record of 1,916 m at Vaguvarai, Idukki, Kerala which are outside its currently known distribution and elevation ranges. As per the present work, the distribution range of U. montanus has extended northwards by 130 km and upwards by 216 m. Additionally, the IUCN Red List status for the species is also discussed based on the area of occupancy and extent of occurrence redone considering the new range envelope.

Testing Geology with Biology: Plate Tectonics and the Diversification of Microhylid Frogs in the Papuan Region.

Studies of the Papuan region have provided fundamental insights into the evolutionary processes generating its exceptional biodiversity, but the influence of geological processes merits further study. Lying at the junction of five tectonic plates, this region has experienced a turbulent geological history that has not only produced towering mountains allowing elevational specialization and island archipelagos with varying degrees of isolation promoting vicariance, but also active margins where land masses have collided and been subsequently rifted apart creating a mosaic of intermixed terranes with vastly different geological histories. Asterophryine frogs are a hyperdiverse clade representing half the world's microhylid diversity (over 360 species) centered on New Guinea and its satellite islands. We show that vicariance facilitated by geological history explains this far and wide distribution of a clade that should have poor dispersal abilities. We recovered a mainland tectonic unit, the East Papua Composite Terrane (EPCT), as the center of origin for Asterophryinae and no fewer than 71 instances of what appear to be long-distance dispersal events, 29 of which are between mainland regions, with 42 from the mainland to the islands, some presently as far as 200km away from source populations over open ocean. Furthermore, we find strong support for a "Slow and Steady" hypothesis for the formation of the northern margin of New Guinea by many separate accretion events during the Miocene, over other major geological alternatives, consistent with the 20M year age of the clade and arrival via the EPCT. In addition, the historical biogeography of our frogs strongly supports an affiliation of the Louisiade Archipelago and Woodlark Island with the Owen Stanley Range on the EPCT, and the recent proximity of the large New Britain Island. Our results show that Asterophryinae did not have to repeatedly and independently disperse across large ocean barriers to the offshore islands, against the predictions of island biogeography theory, but that the current distribution can be explained through vicariance and short-distance oceanic dispersal as historical land connections disappeared and islands slowly became separated from each other. We show that islands have a life history, changing in distance from other land masses, with consequent opportunities for dispersal, isolation, and cladogenesis of their biotas. More broadly, we can begin to see how the geological history of the Papuan region can result in the rapid accumulation and staggering number of extant species.

Resolving the deep phylogeny: Implications for early adaptive radiation, cryptic, and present-day ecological diversity of Papuan microhylid frogs

The microhylid frogs of the New Guinea region are the largest and most ecologically diverse subfamily (Asterophryinae) of one of the largest anuran families in the world and can live in communities of up to 20 species. While there has been recent progress in resolving the phylogenetic relationships of Asterophryinae, significant uncertainties remain, impeding further progress in understanding the evolution of microhabitat use, parental care, and life history variation in this group. In particular, the early divergences at the base of the tree remain unclear; as does the monophyly of some genera; and recent studies have discovered that species with wide geographic distribution are instead cryptic species complexes. In this study, we fortified geographic sampling of the largest previous phylogenetic effort by sequencing an additional 62 taxa and increased data quality and quantity by adding new layers of data vetting and by filling in previously incomplete loci to the five gene dataset (2 mitochondrial, 3 nuclear protein-coding genes) to obtain a dataset that is now 99% complete in over 2400 characters for 233 samples (205 taxa) of Asterophryinae and 3 outgroup taxa, and analyzed microhabitat use data for these taxa from field data and data collected from the literature. Importantly, our sampling includes complete community complements at 19 sites as well as representatives at over 80 sites across New Guinea and its offshore islands. We present a highly resolved molecular phylogeny which, for the first time, has over 95% of nodes supported (84% highly supported) whether using Maximum Likelihood or Bayesian Inference, allowing clarification of all genera (whether monophyletic or clearly not), their sister genera relationships, as well as an age estimate for the Asterophryinae at approximately 20MYA. Early generic diversification occurring between 17 and 12 MYA gave rise to a surprising diversity of about 18 genera as well as the 5 putative microhabitat types. Our tree reveals extensive cryptic diversity calling any widespread taxa into doubt, and clearly demonstrates that complex multispecies communities of Asterophryinae are ecologically diverse, are numerous, and of ancient origin across New Guinea. We discuss the implications of our phylogeny for explaining the explosive diversification of Asterophryinae as the result of adaptive radiation, niche conservatism, and non-adaptive radiation.

“Reproductive Ecology of Narrow mouthed frog Microhyla ornata”

: Reproductive ecology of Narrow mouthed frog Microhyla ornata was studied at selected breeding sites around Dharwad, Karnataka India during the wet periods between May 2017 and December 2018. The breeding activity varied depending upon the amount of rainfall. It was higher during monsoon when there was higher rainfall, whereas, when rainfall was scanty less activity was observed. Males begin the calling activity in the evening after the sunset at 1098min reaching its peak at around 1200min and extend till the early morning of the next day. Gravid females arrive at the breeding site one to one and half hour after the calling was initiated in the early pre-monsoon and monsoon period and amplexus took place soon after the arrival of females within one hour during peak calling days. Size assorted matting was observed in M. ornata and showed significant positive correlation. The female body size was positive correlation with clutch size. However, there was no significant correlation between female body size and egg size. Breeding activity of M. ornata spanning for seven months suggest that, this species is a prolonged breeder. The eggs and larvae of M. ornata were under constant threat by the predatory larva of the aquatic insects like Dragonfly and Water beetle. Few clutches during non rainy period faced the risk of desiccation. The breeding sites of many anurans are affected by urbanization and habitat fragmentation. There is a need to adopt the strategy to conserve the habitats to protect the species.

An unexpected new red-bellied Stumpffia (Microhylidae) from forest fragments in central Madagascar highlights remaining cryptic diversity.

The Madagascan endemic subfamily Cophylinae in the family Microhylidae, is an example of a taxonomic group for which much is still to be discovered. Indeed, the cophyline frogs present a large portion of Madagascar's cryptic and microendemic amphibian diversity, yet they remain understudied. A new red-bellied species of the microhylid frog genus Stumpffia is described from the central plateau of Madagascar. Visual encounter surveys in Ambohitantely and Anjozorobe in 2019 and 2020 identified this previously unknown Stumpffia species, which closely resembles Stumpffiakibomena known from Andasibe in the east. Stumpffialynnae sp. nov. adds another species to the red-bellied species complex, differing from S.kibomena by genetic differentiation in the mitochondrial 16S rRNA gene (3.6-3.9%) and distinct nuclear RAG1 haplotypes, as well as strongly by its advertisement call. The new species is known from across Ambohitantely Special Reserve and Anjozorobe Angavo protected area, but is known only from one complete specimen and eight individual tissue samples. Based on the rarity of the species, the small number of locations in which it has been found, and its disappearing forest habitat, its IUCN Red List classification is suggested as "Endangered". This species is the first Stumpffia described from Madagascar's central plateau, highlighting the importance of conserving the remnant forest fragments in this area and the ongoing need to survey and protect this threatened habitat type.

A needle in a haystack: Integrative taxonomy reveals the existence of a new small species of fossorial frog (Anura, Microhylidae, Synapturanus) from the vast lower Putumayo basin, Peru

We describe a new species of microhylid frog of the genus Synapturanus from the lower Putumayo basin in Loreto, Perú. Specimens inhabited the soils of stunted pole forests growing on peat. The new species is distinguished from other species of Synapturanus through morphology, genetics, and acoustic characteristics. This species differs from most nominal congeners by having a head flat in lateral view (vs convex in the rest of species), a characteristic only shared by S. rabus and S. salseri. The new species can be distinguished from S. rabus and S. salseri by a combination of morphological characters and by having an advertisement call with a note length of 0.05–0.06 seconds (vs 0.03 seconds in S. rabus) and a dominant frequency ranging from 1.73 to 1.81 kHz (vs 1.10–1.47 kHz in S. salseri). Principal component analyses of 12 morphological characters and three acoustic variables further support differences between the new species and its described and undescribed congeners.

Oral structure and diet of larval Berdmore's Narrow-mouthed Frogs, Microhyla berdmorei (Blyth 1856) from Mizoram, India.

Oral structure and diet of larval Berdmore's Narrow-mouthed Frogs, Microhyla berdmorei (Blyth 1856) from Mizoram, India.

Mathematically Modeling Prey-Catching Behavior of the Tomato Frog

Many microhylid frog species, such as the tomato frog, Dyscophus sp., have demonstrated the ability to aim their tongues independently of head and jaw movements. However, a trade-off between tongue-aiming and head-only aiming exists in which the former allows for crypsis but lacks speed whereas the latter is faster but less accurate and more noticeable to prey. For frogs that can move their tongues independently of their heads, under what circumstances will they utilize each strategy, and why? We derive a model, dependent on factors relevant for prey-catching, for the probability the frog will turn its head (and not tongue) given the prey angle. Our model behaves as expected when altering prey-catching factors, but underestimates head turning behavior with increasing prey angle. We later allow for variance in perceived prey location to be a function of prey angle. We find such variance must generally increase with prey angle.

A New Species of <i>Vietnamophryne</i> with an Extended Description of <i>Vietnamophryne orlovi</i>

We describe Vietnamophryne cuongi sp. nov., a new species of microhylid frog from northern Vietnam, based on morphological and molecular differences. Although superficially similar to remaining Vietnamophryne members, the new species differs by a number of diagnostic morphological characters, such as body size, habitus, head dimensions, finger and toe morphology, skin texture, as well as colour pattern. Phylogenetic analyses based on a fragment of the mitochondrial 16S gene place the new species to be sister to V. orlovi, from which it differed by 2.4% genetic divergence. We also describe the first female known of V. orlovi, collected in the forest of Phia Oac-Phia Den National Park, Cao Bang Province. The latter species, for which we provide an extended description herein, was recently described based on the single male type specimen only from the same site in northern Vietnam. Vietnamophryne cuongi sp. nov. is only known from three specimens, two adult females and a juvenile, from the evergreen tropical forest of Ba Vi National Park, Hanoi. As such, it is likely to be at high risk of habitat loss. Considering its high ecological specialization and the small known distribution range of the new species, we propose Endangered as IUCN Red List status.

Carry-Over Effects of Desiccation Stress on the Oxidative Status of Fasting Anuran Juveniles.

Amphibians are sensitive to deteriorating environmental conditions, especially during transition to a terrestrial environment which is full of uncertainties. Harsh conditions, such as desiccation during earlier stages, affect different larval traits with possible carry-over effects on juvenile and adult life histories. The first consequences of the effects can be seen in juveniles in the challenges to find food and the ability to survive without it in a terrestrial habitat. Body size and the internal energy reserves acquired during the larval phase play an important role in this period. Herein, we tested how different water regimes (low water availability, desiccation and constant high-water availability) during larval development reflect on the oxidative status and ability of yellow belly toad (Bombina variegata) juveniles to endure short-term fasting. The desiccation regime significantly reduced the body size of metamorphs. The same was observed after 2 weeks of fasting, while the feeding treatment reduced differences mostly in the body mass of individuals from different water regimes. This was the result of a greater gain in mass in juveniles pre-exposed to desiccation. Pre-exposure to desiccation also modified the parameters of the antioxidant system (AOS) under feeding conditions, leading to higher values of superoxide dismutase, glutathione reductase and glutathione S-transferase, glutathione and sulfhydryl group concentrations, and lower glutathione peroxidase in comparison to juveniles reared under constant water. The increase in the AOS of juveniles can be considered as a physiological carry-over effect of desiccation, probably as the result of compensatory growth and/or earlier exposure to chronic stress. However, water levels during larval development did not exert significant effects on the oxidative status of juveniles subjected to food unavailability. Fasting juveniles, both control and desiccated, were exposed to oxidative stress, significantly higher lipid peroxide concentrations, lower superoxide dismutase, glutathione peroxidase, glutathione S-transferase, glutathione and sulfhydryl group values in comparison to feeding individuals. The lack of food in juvenile anurans activated the AOS response in the same manner, regardless of body size and stress pre-exposure, suggesting that the generally accepted hypothesis about the influence of metamorphic body size on the fitness of the postmetamorphic stage should be tested further.

Biophysical study of the structure and dynamics of the antimicrobial peptide maximin 1.

Maximin 1 is a cationic, amphipathic antimicrobial peptide found in the skin secretions and brains of the Chinese red belly toad Bombina maxima. The 27 amino acid residue-long peptide is biologically interesting as it possesses a variety of biological activities, including antibacterial, antifungal, antiviral, antitumour and spermicidal activities. Its three-dimensional structural model was obtained in a 50/50% water/2,2,2-trifluoroethanol-d3 mixture using two-dimensional NMR spectroscopy. Maximin 1 was found to adopt an α-helical structure from residue Ile2 to Ala26 . The peptide is amphipathic, showing a clear separation between polar and non-polar residues. The interactions with sodium dodecyl sulfate micelles, a widely-used bacterial membrane-mimicking environment, were modelled using molecular dynamics simulations. The peptide maintains an α-helical conformation, occasionally displaying a flexibility around the Gly9 and Gly16 residues, which is likely responsible for the peptide's low haemolytic activity. It is found to preferentially adopt a position parallel to the micellar surface, establishing a number of hydrophobic and electrostatic interactions with the micelle.

A tiny new species of Microhyla Tschudi, 1838 (Amphibia: Anura: Microhylidae) from Belitung Island and Southeastern Sumatra, Indonesia.

A tiny new species of narrow-mouthed frog of the genus Microhyla is described from the island of Belitung and southeastern Sumatra, Indonesia. The most distinctive feature of the new frog is its diminutive adult size, snout-vent length ranging only from 12.3 to 15.8 mm in adult males. Phylogenetic analyses based a fragment of the mitochondrial 16S rRNA gene, along with detailed morphological and acoustic comparison differentiate the new taxon from all known congeners. The new species, formally described as Microhyla sriwijaya sp. nov., is a member of the M. achatina species group and the sister taxon to M. orientalis. It is diagnosable from other congeners by a combination of characters: (1) smaller male snout-vent size 16 mm; (2) snout obtusely rounded in dorsal view; (3) absence of mid-dorsal line and skin fold; (4) first finger reduced (finger I length less than half of finger II length); (5) dorsum with a prominent dark median mark extending posteriorly, narrow anteriorly near the level of the shoulder and expanding dorsolaterally up to the vent; margins of the dorsal marking concave with broad reddish-brown or orange colouration on either side; (6) foot webbing rudimentary, reaching just up to the first subarticular tubercle on all toes; (7) dorsal skin with prominent tubercles, especially in life; (8) tibiotarsal articulation of adpressed limb reaching beyond the snout tip; and (9) males produce a single type of call with pulsatile temporal structure, calls of relatively short duration ranging between 31.862.8 s, with two to three pulses delivered at a rate ranging between 32.236.0 pulses per second, and the mean overall dominant frequency of 4.3 kHz. The uncorrected pairwise genetic distances between Microhyla sriwijaya sp. nov. and all other known congeners are > 3.8% for the studied 16S gene fragment. The new species was discovered from wayside rural areas with oil palm plantations at four localities in the small island of Belitung (type locality), and from coffee plantation and secondary forest at Lampung in southeastern Sumatra. It is not known from any protected area and appears to be threatened due to tin mining activity, intensive logging, oil palm, and other commonly practiced agriculture activities.

Interspecific amplexus between a Bangladeshi Cricket Frog, Minervarya ornata (Bolkay, 1915), and a male Ornate Narrow-mouthed Frog, Microhyla ornata (Microhylidae), from Bangladesh

Interspecific amplexus between a Bangladeshi Cricket Frog, Minervarya ornata (Bolkay, 1915), and a male Ornate Narrow-mouthed Frog, Microhyla ornata (Microhylidae), from Bangladesh

Description of six new species of Xenorhina Peters, 1863 from southern Papua New Guinea (Amphibia, Anura, Microhylidae)

We describe six new species of the microhylid frog genusXenorhinafrom the southern slopes of Papua New Guinea’s central cordillera and adjacent lowlands, based on a combination of morphological (including osteology) and bioacoustic features. All of the new species are fossorial or terrestrial inhabitants of tropical rainforest habitats and belong to a group ofXenorhinahaving a single, enlarged odontoid spike on each vomeropalatine bone. Advertisement calls and habitat preferences are described for each species, one of which is amongst the smallest hitherto members of the genus. Description of these six species brings the total number ofXenorhinaknown to 40 and emphasises the importance of the high-rainfall belt that extends along the southern flanks of New Guinea’s central cordillera as a hotspot of Melanesian amphibian diversity.