DOI: 10.3897/vz.76.e166419

Authors: N. Joris Fleck, Alice Petzold, Andolalao Rakotoarison, Miguel Vences, Mark D. Scherz

Abstract: The role of regional diversification versus the effect of migration in generating local species assemblages remains poorly known. Here, we contribute to the understanding of the role of colonisation and in situ diversification by studying an assemblage of miniaturised microhylid frogs of the genus Stumpffia Boettger, 1881, of which six species have been known to occur on Montagne d’Ambre, a volcanic mountain in the north of Madagascar. These six species are distributed over different, partly overlapping elevational levels. We examined this assemblage based on molecular data (16S mtDNA and Rag1 nDNA), new data on the elevational distribution among local Stumpffia species, and differences in advertisement calls. Our results revealed several genetic lineages constituting distinct species, including another species record for the mountain, S. mamitika Rakotoarison et al., 2017, as well as the new candidate species Stumpffia sp. aff. angeluci. This brings the total number of described species known to occur on the mountain to seven, four of which are micro-endemic. Our data indicate that one clade, consisting of four species, has arisen in situ as a microendemic radiation. We discuss alternative evolutionary scenarios for the biogeographic origin of the observed Stumpffia species.

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DOI: 10.3897/vz.74.e127937

Authors: Alexei V. Trofimets, Christophe Dufresnes, Parinya Pawangkhanant, Andrey M. Bragin, Vladislav A. Gorin, Mahmudul Hasan, Hmar Tlawmte Lalremsanga, Mohd Abdul Muin, Dac Xuan Le, Tan Van Nguyen, Chatmongkon Suwannapoom, Nikolay A. Poyarkov

Abstract: 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. sundaica sp. nov.), while the second one is restricted to the Malay Peninsula and occurs in extreme southern Thailand and adjacent Malaysia (M. peninsularis sp. 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.

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DOI: 10.3897/vz.74.e114285

Authors: Stephen Mahony, Rachunliu G. Kamei, Rafe M. Brown, Kin Onn Chan

Abstract: Abstract Although the differentiation of clades at the species level is usually based on a justifiable and testable conceptual framework, the demarcation of supraspecific boundaries is less objective and often subject to differences of opinion. The increased availability of large-scale phylogenies has in part promulgated a practice of what we consider excessively splitting clades at the “genus” level. Many of these new genus-level splits are predicated on untenable supporting evidence (e.g., weakly supported phylogenies and purportedly “diagnostic” but actually variable, non-exclusive, or otherwise problematic opposing character state differences) without careful consideration of the effects on downstream applications. As case studies, we critically evaluate several recent examples of splitting established monophyletic genera in four amphibian families that resulted in the creation/elevation of 20 genus-level names (Dicroglossidae: Phrynoglossus, Oreobatrachus, Frethia split from Occidozyga; Microhylidae: Nanohyla split from Microhyla; Ranidae: Abavorana, Amnirana, Chalcorana, Humerana, Hydrophylax, Indosylvirana, Papurana, Pulchrana, Sylvirana split from Hylarana; Rhacophoridae: Tamixalus, Vampyrius, Leptomantis, Zhangixalus split from Rhacophorus, Rohanixalus split from Feihyla, Orixalus split from Gracixalus, and Taruga split from Polypedates), and also address the taxonomic status of the monotypic genus Pterorana relative to Hylarana. We reassess the original claims of diagnosability and justifications for splitting and argue that in many cases, the generic splitting of clades is not only unnecessary but also destabilizes amphibian taxonomy, leading to a host of downstream issues that affect categories of the user community (stakeholders such as taxonomists, conservationists, evolutionary biologists, biogeographers, museum curators, educators, and the lay public). As an alternative, we advocate for the use of the subgenus rank in some cases, which can be implemented to establish informative partitions for future research without compromising on information content, while avoiding gratuitous (and often transient) large-scale binomial (genus-species couplet) rearrangements. We encourage taxonomists to consider the actual needs and interests of the larger non-taxonomic end-user community who fund the majority of taxonomic research, and who require a system that remains reasonably stable and is relatively intuitive, without the need for inaccessible laboratory equipment or advanced technical scientific knowledge to identify amphibian species to the genus level.

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DOI: 10.3897/vz.73.e94207

Authors: Rainer Günther, Djoko T. Iskandar, Stephen J. Richards

Abstract: The microhylid genus Oreophryne reaches its greatest diversity in the New Guinea region, where more than 60 species have been documented to date. Most Oreophryne are small (<30 mm SVL) and only three species, O. anthonyi, O. idenburgensis and O. inornata, exceed 40 mm SVL adult body size. Here we describe a fourth large species of Oreophryne that was collected in 1998 from the mountains of Papua Province in western New Guinea. In having a cartilaginous connection between the procoracoid and scapula it is most similar to O. idenburgensis, a species known only from the mountains of central-western New Guinea but differs from that species in a suite of morphological characters including a broader head, a hidden (vs. visible) tympanum and a more pointed snout.

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DOI: 10.3897/vz.72.e85020

Authors: Ananthanarayanan Sankar, Ingg Thong Law, Ing Sind Law, Rasu Shivaram, Robin K. Abraham, Kin Onn Chan

Abstract: The genus Micryletta, also known as paddy frogs, ranges across much of south, east, and southeast Asia. Due to their relatively broad distribution and overall morphological similarities, many species have gone undetected until recently, largely owing to the use of molecular data. Consequently, the species diversity within this genus has quadrupled in just three years from three species prior to 2018, to 12 species in 2021, indicating that the systematics of this genus is still poorly understood. As such, we assembled the most comprehensive molecular phylogeny of Micryletta hitherto including novel sequences from a previously unsampled population from Singapore to assess the species diversity within this genus. In particular, we investigate the population from Singapore whose specific identity remains in question due to the lack of voucher specimens and genetic material. Our results show that the Singapore population represents a strongly supported and distinct lineage that is most closely related to M. inornata sensu stricto from Sumatra, Indonesia. Morphological and species delimitation analyses corroborate its distinction as a new species, which we describe herein as M. subaraji sp. nov. This and recent new taxon discoveries in Singapore demonstrate that the biodiversity of the highly urbanized island-state is still far from being fully realized and underscores the need for continued systematic surveys and protection of remaining habitats.

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DOI: 10.3897/vz.71.e66954

Authors: Rainer Günther, Chris Dahl, Stephen J. Richards

Abstract: Abstract We describe a new species of the asterophryine microhylid genus Xenorhina from the lowlands of northwestern Papua New Guinea. It is a medium-sized species (SUL of two males 29.2 and 29.9 mm; of four females 29.9–33.0 mm) that can be distinguished from congeners by having a single short, triangular odontoid spike (palatal tooth) on each vomeropalatine bone, moderately short legs (TL/SUL 0.40–0.44) and ventral surfaces heavily spotted with reddish-brown blotches or reticula. The advertisement call comprises 7–10 loud, melodious hooting notes lasting 141–165 ms and produced at a repetition rate of 2.19–2.35 notes/s. Description of this species brings to 41 the number of Xenorhina known from New Guinea and surrounding islands.

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