Emergent infectious disease caused by the fungal pathogens Batrachochytrium dendrobatidis (Bd) and Batrachochytrium salamandrivorans (Bsal) represents one of the major causes of biodiversity loss in amphibians. While Bd has affected amphibians worldwide, Bsal remains restricted to Asia and Europe, but also could be a major threat for salamanders in the Western hemisphere, including the 320 bolitoglossine species described. Here, we predict the suitable areas for Bsal in the Neotropics and assess its potential impact on bolitoglossine diversity. For this, we determined the geographic patterns of taxonomic, phylogenetic, and functional diversity for bolitoglossines and modeled the potential distribution of Bsal in the Neotropics. We identified which species and regions could be at risk from an eventual introduction of Bsal in the region, quantified the degree of overlap between regions of high diversity and the suitable conditions for the pathogen, and considered species IUCN Red List status, and geographic range size. We found that regions of high taxonomic, phylogenetic, and functional diversity are concentrated in the Trans‐Mexican Volcanic Belt, Sierra Madre Oriental, the southern portion of Sierra Madre del Sur and the mountains of Oaxaca in México, as well as the Chiapan‐Guatemalan highlands, and the Cordilleras of Costa Rica and Panama. Alarmingly, the regions of high diversity for bolitoglossines and over 75% of the ranges of the more threatened species could be affected by Bsal. Given the unknown vulnerability of these species, we strongly recommend measures to avoid the introduction of Bsal in the continent. Abstract in Spanish is available with online material.

The genus Chiropterotriton is endemic to Mexico with a geographical distribution along the Sierra Madre Oriental, the Trans Mexican Volcanic Belt and the Sierra de Juárez. The recent use of molecular tools has shown that Mexico’s amphibian diversity is highly underestimated, including a large number of cryptic, unnamed species. Chiropterotriton has 18 described species including terrestrial, arboreal and cave-dwelling species. In previous molecular studies, the presence of multiple undescribed species was evident. We present a phylogenetic hypothesis based on mitochondrial data, which includes all described species and six undescribed taxa. Based on the morphological analyses and, when available, combined with molecular data, we describe five new species of the genus; Chiropterotriton casasi sp. nov., C. ceronorum sp. nov., C. melipona sp. nov., C. perotensis sp. nov. and C. totonacus sp. nov. In addition, we redescribe two others: Chiropterotriton chiropterus and C. orculus, and provide a comparable account of one additional sympatric congener. This increases the number of species in the genus to 23, which represent a considerable component of Mexican plethodontid richness.

Chiropterotriton is a relatively small genus that comprises 15 species with great morphological and ecological diversity. In previous studies, molecular data provided evidence for a considerable number of species that remain undescribed. In this study, we describe one new species, Chiropterotriton chico sp. nov. based on molecular and morphological characters. We present mtDNA phylogenetic analyses using Bayesian inference and maximum likelihood that include all described and several undescribed species. Morphometric data from eight recognized species provide evidence for the distinctiveness of the new taxon. Description of this new species adds to the already high salamander diversity of the state of Hidalgo, which is an important area for the diversification of the genus.

Summary Symbiotic bacterial communities are crucial to combating infections and contribute to host health. The amphibian skin microbiome plays an important role in protecting their hosts against pathogens such as Batrachochytrium dendrobatidis (Bd), one of the causative agents of chytridiomycosis, which is responsible for dramatic amphibian population declines worldwide. Although symbiotic skin bacteria are known to inhibit Bd growth, an understanding of the relationship between Bd genetic variability, environmental conditions, and skin bacterial communities is limited. Therefore, we examined the associations between Bd infection load, Bd genetic diversity and skin bacterial communities in five populations of Hyliola regilla (hypochondriaca) from environmentally contrasting sites in Baja California, Mexico. We observed differences in Bd genetics and infection load among sites and environments. Genetic analysis of Bd isolates revealed patterns of spatial structure corresponding to the five sites sampled. Amphibian skin bacterial diversity and community structure differed among environments and sites. Bacterial community composition was correlated with Bd genetic differences and infection load, with specific bacterial taxa enriched on infected and un‐infected frogs. Our results indicate that skin‐associated bacteria and Bd strains likely interact on the host skin, with consequences for microbial community structure and Bd infection intensity.