Alessandro Catenazzi

We describe a new species of Dipsas Laurenti, 1768 from the inter-Andean valley of the Mantaro River in southern Peru based on external morphology and DNA sequences. The new species is most similar to coastal and Andean species from Ecuador and Peru, such as: D. georgejetti, D. jamespetersi, D. oligozonata, D. oneilli, D. oswaldobaezi, D. vagrans, D. vagus, and D. williamsi. Many of these species had previously been assigned to the genus Sibynomorphus. The new species is easily distinguished from congeneric species by lacking preoculars and by its unique scalation and coloration patterns. In addition, we assess its conservation status, categorizing the species as Least Concern, and discuss species richness of the genus Dipsas in Peru, with particular emphasis on the taxonomic status of D. peruana.

The Andes harbor extraordinary species richness, but a substantial proportion of their biodiversity remains insufficiently documented. Among their most diverse lineages are lizards of the family Gymnophthalmidae, whose diversity remains underestimated. Here, we assess the phylogenetic position and taxonomic status of a poorly known group of cercosaurine lizards from the eastern slopes of the central Peruvian Andes. We examined preserved specimens from the departments of Pasco and Huánuco and obtained DNA sequences of one nuclear (c-mos) and four mitochondrial markers (12S, 16S, ND4, and Cytb). These sequences were combined with data retrieved from GenBank to assemble a multilocus matrix of 2290 base pairs representing 153 terminal taxa. Phylogenetic relationships were inferred under a maximum-likelihood approach. The six focal specimens formed a clade within Cercosaurini, with strong support (UFBoot = 100) for its phylogenetic placement and monophyly. This new clade is distinguished from closely related genera by a distinctive combination of external morphological characters, including the presence of precloacal pores and the third subocular extending ventrally between the supralabial scales. Based on the congruence between molecular and morphological evidence, we describe Perusaurus gen. nov., transfer Petracola labioocularis to the new genus as Perusaurus labioocularis comb. nov., and based on morphological evidence, we also transfer Proctoporus laudahnae to Perusaurus laudahnae comb. nov. The clade also includes at least two species awaiting formal description. The recognition of Perusaurus demonstrates that the evolutionary diversity of Cercosaurinae in the Peruvian Andes remains considerably underestimated.

We describe five new species of the Pristimantis lacrimosus group based on morphological traits, molecular data, and, in two species, bioacoustic characters. The five new species can be distinguished from their congeners by the combination of features such as snout shape, presence or absence of rostral papilla, skin texture, size, and coloration pattern. Pristimantis aisatipoki sp. nov. is known from elevations of 1466 and 1723 m in the Amazon slope of Junín department in central Peru. Pristimantis basicordellum sp. nov. and P. culmecordellum sp. nov. are known from elevations of 300 and 1700 m, respectively, in the Cordillera Escalera, Loreto department, in northeastern Peru. Pristimantis rhodocanthus sp. nov. is known from an elevation of 1778 m in the Amazon slope of San Martín department in northeastern Peru. Pristimantis solitarius sp. nov. is known only by the holotype from an elevation of 183 m in the Amazon lowlands of Huánuco department in central Peru.

We describe a new species of marsupial frog of the genus Gastrotheca, using morphological characters, bioacoustics, and molecular data as lines of evidence. The new species was discovered in the humid forests of the lower Mantaro Basin in the Central Andes of central Peru, at 2590 m a.s.l. It is distinguished from all congeners by the following combination of characters: head width equal to head length; no transverse cranial ridges; snout truncated in dorsal and lateral views; and golden-yellow dorsal, lateral, and ventral coloration. We describe the advertisement call of adult males. According to our phylogenetic analyses, the new species belongs to the Gastrotheca marsupiata species group and is closely related to G. rebeccae and G. pachachacae. We tested for the presence of the fungal pathogen Batrachochytrium dendrobatidis (Bd); no Bd infection was detected in the new species, but Bd infection was detected in a sympatric individual of Pristimantis. We also provide the first records of Hyloscirtus armatus and Rhinella leptoscelis for the department of Huancavelica extending their known distribution from the Amazonian versant of southern Peru and Bolivia into an inter-Andean valley of central Peru.

The Peruvian Andes harbor one of the most geographically complex and biologically diverse regions of the Tropical Andes, yet several microbasins and mountain ridges remain poorly surveyed for amphibians. Here, we describe four new species of the terrestrial-breeding frog genus Oreobates from the departments of Amazonas, San Martín and Huánuco, Peru, based on morphology, coloration, and molecular phylogenetic analyses. The new species inhabit humid montane and premontane forests of the upper basin of the Huallaga River. The new taxa differ from congeners by combinations of body size, skin texture, digital morphology, coloration, and iris pattern. Phylogenetic analyses recovered the new species within distinct lineages of Oreobates, supporting their recognition as independent evolutionary entities. Our results further highlight the role of Andean topography, especially dry inter-Andean valleys associated with the Marañón, Apurímac, and Mantaro systems, as important barriers shaping diversification in Andean amphibians. These discoveries emphasize the underestimated diversity of Oreobates in the Peruvian Yungas and reinforce the importance of continued taxonomic exploration of the Andean ecosystems.

1. Frog-biting midges (Diptera: Corethrellidae) are hematophagous insects that locate hosts by eavesdropping on anuran vocalisations, creating a close ecological link between midge and anuran assemblages. Despite this association and the distinct elevational distribution patterns of anurans worldwide, the structure and distribution of Corethrella communities along elevational gradients remain poorly documented. 2. We investigated patterns of richness, abundance, and community turnover of Corethrella along a ~3000 m elevational gradient (500–3400 m a.s.l.) in the Kosñipata Valley, southeastern Peru. Using standardised frog-call baited traps and molecular barcoding, we quantified α- and β-diversity across 200 m elevational bands. 3. A total of 196 individuals were recorded between 400 and 2250 m a.s.l., with no specimens detected above ~2250 m. Species richness of Corethrella declined non-linearly with elevation, while Shannon diversity showed no monotonic trend with elevation, instead exhibiting a non-linear pattern with local minima at intermediate elevations. β-diversity was high across the gradient and driven primarily by species turnover rather than nestedness. 4. Community composition changed markedly among elevational bands, with cluster and ordination analyses separating lowland and montane assemblages. The highest occupied band (2200–2400 m a.s.l.) contained only phylogenetically distinct species absent from lower elevations, indicating strong compositional differentiation at the upper elevation range limit. 5. These results demonstrate a sharply bounded elevational distribution and strong turnover in Corethrella communities along a tropical montane gradient. The absence of midges above ~2400 m, despite the continued presence of amphibian hosts, suggests that abiotic constraints limit their distribution. Our study highlights the role of elevation on midge communities, revealing unique mid-elevation assemblages, a pattern likely to have important implications for their associations with anurans.

We describe Gastrotheca mittaliiti sp. nov. from the subalpine paramo of Amazonas department in the Andes of northern Peru, in the Huancabamba region, based on phylogenetic analysis of DNA sequences from three mitochondrial and two nuclear genes, genetic distances, and diagnostic morphological characters. Our phylogenetic analysis recovered the new species with high support both as part of the Gastrotheca marsupiata species group and as the sister species of G. trachyplevra. The new species can be distinguished from the rest of its congeners by the combination of the following characters: (i) moderately small size in males (SVL = 27.6–32.5 mm, n = 4); (ii) distinctly thick and elevated supratympanic fold extending from the top edge of the tympanum to the flank covered with prominent and closely packed or fused pustules; (iii) two prominent paravertebral longitudinal pustular ridges; (iv) narrow discs on fingers and toes with truncate terminal margins; (v) dorsum covered with prominent and closely packed rounded pustules; (vi) canthus rostralis thin and straight in dorsal view; and (vii) distal subarticular tubercle rounded. In addition, we report the first record of G. turnerorum in Peru and describe new morphological variation of the Peruvian populations. Our results highlight the Huancabamba region as the hotspot of Gastrotheca species richness, a result that we discuss from a biogeographic and conservation perspective.

We describe three new species of Pristimantis frogs from northwestern Peru on the basis of morphological and genetic differences. Pristimantis chinguelassp. nov. is similar in appearance to P. wagteri but it differs by having a longer supratympanic fold, head rounded in profile, groins and posterior surfaces of thighs in a different color pattern. Pristimantis nunezcortezisp. nov. may be confused with P. cryptomelas, but it is differentiable by having heels with a single low tubercle, skin on flanks areolate, and by lacking prominent postorbital ridges. Pristimantis yonkesp. nov. is externally similar to P. morlaco from Ecuador, but can be distinguished by being smaller, having an acuminate snout, oval palmar tubercle and lacking dentigerous processes of vomers. All species inhabit the paramos and adjacent elfin forests of the mountain ridges north of Abra de Porcuya, the lowest east-west pass in the Peruvian Andes. Despite habitat loss being evident in the area, we do not have enough data to assess their conservation status. We suggest all the new species should be placed in the Data Deficient category of the IUCN Red List.

Shifting precipitation regimes driven by global climate change can alter vertebrate behavior and host‐symbiont relationships, potentially compromising host resistance to pathogen invasion. In Brazil's Atlantic Forest, a biodiversity hotspot, prior research identified drought as a key factor disrupting the skin microbiome, contributing to a die‐off of pumpkin toadlets due to the invasive waterborne fungal pathogen Batrachochytrium dendrobatidis (Bd). However, observational studies cannot disentangle the direct effect of moisture on Bd growth from increased amphibian activity during wet breeding seasons. Using field enclosures, we experimentally tested the influence of drought conditions on host microhabitat use, Bd disease dynamics, and the composition and predicted Bd‐inhibitory function of cutaneous bacterial communities. Each enclosure housed ecologically realistic densities of Brachycephalus pitanga, a micro‐endemic pumpkin toadlet. We simulated a short‐term drought in half of the enclosures using translucent tarp coverings. To track individual toadlets, we identified their unique markings and collected skin swabs biweekly over 3 months. We then implemented molecular techniques to quantify Bd loads and characterize skin bacterial diversity and composition over time. Our findings indicate that while drought may reduce overall Bd loads on hosts, this effect is partially offset by an increase in the use of water‐filled areas of the enclosures and by a disruption of the protective host skin microbiome. This study provides valuable insights into the cascading impacts of climate change on animal behavior, host‐symbiont interactions, and disease dynamics.