The town of Valle de Anton is located in the crater of an extinct volcano and protects great biodiversity. Considering this biological wealth, monitoring was carried out on the Square Trees Natural Trail. Over a six-month period between August 2022 and January 2023, three 100 m line transects and three 100 m sites were established for widespread searching. 956 individuals of amphibians and 44 of reptiles were observed, with the rocket frog Silverstoneia floatatorand among the reptiles the river anole Anolis lionotusbeing the most abundant, with 204 and 10 individuals respectively. Transect 1 proved to be the site with the most abundance of individuals, where the glass frog Sachatamia albomaculatarecorded 153 individuals and the most abundant reptile species was the Meracho Basiliscus basiliscus, with seven individuals. The diversity proved to be moderately high, with no species dominancebetween the two groups, and the accumulation curve estimated a high richness for amphibians and a low one for reptiles. Species of conservation concern according to IUCN categories and the Environmental Vulnerability Score (EVS) demonstrate that the snake Trimetopon barbouridoes not have sufficient data on distribution and abundance. The amphibians with high vulnerability were Pristimantis taeniatus, Silverstoneia flotator, Diasporusdiastemaand Pristimantis gaigei. In the case of reptiles, those with high vulnerability were Anolis lionotus, Lepidoblespharis sanctaemartae, Anolis gaigei, Anolis humilis and Sibon argus. Finally, through this study we were able to provide new data on the population dynamics of amphibians and reptiles in a vulnerable and tourist-oriented site, where the instability of the habitat due to climate change and anthropogenic expansion increasingly depletes the resources necessary to the subsistence of these organisms.

AbstractAnthropogenic biodiversity loss is extreme in amphibians. Despite ongoing conservation action, it is difficult to determine where we stand in overcoming their extinction crisis 1,2. Extinction risk is not equally distributed across amphibians 3-5. Among the most threatened amphibians are the 131 Neotropical harlequin toads (Atelopus), many of which dramatically declined since the late 1980s with several considered possibly extinct 5,6. Recently, more than 30 species have been rediscovered7, raising hope for a reversing trend in the amphibian extinction crisis. We use harlequin toads, for which comprehensive past and present population status, threat and conservation action data are available, as a model for examining whether the amphibian extinction crisis is still in a state of emergency. We show that since 2004 no species has improved its population status, suggesting that the conservation community has not yet bent the curve. Threats such as pathogen spread and habitat change persist unabated; additionally, climate change is expected to be a future threat. More on-the-ground mitigation strategies need implementation, especially habitat protection and disease management, combined with captive conservation breeding. With harlequin toads serving as a model for amphibians with high extinction risk, it is clear that the amphibian extinction crisis is still underway.

Biodiversity loss is extreme in amphibians. Despite ongoing conservation action, it is difficult to determine where we stand in overcoming their extinction crisis. Among the most threatened amphibians are the 131 Neotropical harlequin toads. Many of them declined since the 1980s with several considered possibly extinct. Recently, more than 30 species have been rediscovered, raising hope for a reversing trend in the amphibian extinction crisis. We use past and present data available for harlequin toads ( Atelopus ), to examine whether the amphibian extinction crisis is still in an emergency state. Since 2004 no species has improved its population status, suggesting that recovery efforts have not been successful. Threats include habitat change, pathogen spread and climate change. More mitigation strategies need implementation, especially habitat protection and disease management, combined with captive conservation breeding. With harlequin toads serving as a model, it is clear that the amphibian extinction crisis is still underway.

Substantial molecular and morphological character differences lead us to the description of a new species of the genus Pristimantis from the cloud forest of Cerro Chucantí, Maje Mountains, Darien Province, as well as from several other mountain ranges in eastern and central Panama. Pristimantisgretathunbergae sp. nov. is a sister species to the allopatric P.erythropleura-penelopus group from northern Colombia with a mtDNA sequence divergence of > 4.4% at 16S and > 14.6% at COI. Its closest congener in sympatry is P.cruentus that differs by a large sequence divergence of > 9.6% in 16S mtDNA and 19.0% at COI, and from which it differs also by ventral and groin coloration, unusually prominent black eyes, a contrasting light upper lip, commonly a single conical to spine-like tubercle on the upper eyelid, and a larger head. While the habitat continuity at most sites in eastern Panama is moderate, habitats in central Panama are severely fragmented. Cerro Chucantí and the surrounding Maje Mountains are highly threatened by rapid deforestation and replaced by plantations and cattle pastures. Thus, investigations on the ecology of the new species and its population status, especially at the type locality, are highly recommended. As a flagship species, this new frog can help to preserve the Chucantí cloud forest including several recently described species known only from this isolated area in eastern Panama.

Infectious diseases rarely end in extinction. Yet the mechanisms that explain how epidemics subside are difficult to pinpoint. We investigated host-pathogen interactions after the emergence of a lethal fungal pathogen in a tropical amphibian assemblage. Some amphibian host species are recovering, but the pathogen is still present and is as pathogenic today as it was almost a decade ago. In addition, some species have defenses that are more effective now than they were before the epidemic. These results suggest that host recoveries are not caused by pathogen attenuation and may be due to shifts in host responses. Our findings provide insights into the mechanisms underlying disease transitions, which are increasingly important to understand in an era of emerging infectious diseases and unprecedented global pandemics.

We conducted a molecular assessment of Colostethus-like frogs along an elevational gradient in the Serranía de Pirre, above Santa Cruz de Cana, eastern Panama, aiming to establish their species identity and to determine the altitudinal distribution of C. latinasus. Our findings confirm the view of C. latinasus as an endemic species restricted to the highlands of this mountain range, i.e., 1350-1475 m.a.s.l., considered to be type locality of this species. We described the advertisement call of C. latinasus that consists of a series of 4-18 single, short and relatively loud "peep"-like notes given in rapid succession, and its spectral and temporal features were compared with calls of congeneric species. For the first time, DNA sequences from C. latinasus were obtained, since previously reported sequences were based on misidentified specimens. This is particularly important because C. latinasus is the type species of Colostethus, a genus considered paraphyletic according to recent phylogenetic analyses based on molecular data.

1Department of Biology, New Mexico Institute of Mining and Technology, Socorro, New Mexico 87801, USA 2Department of Ecology and Evolutionary Biology, Tulane University, New Orleans, Louisiana 70118, USA 3Department of Environmental Science Policy and Management, University of California, Berkeley, Berkeley, California 94720, USA 4El Valle Amphibian Conservation Center, El Valle, PANAMÁ 5Smithsonian Conservation Biology Institute, Washington D.C., USA 6Smithsonian Tropical Research Institute, P.O. Box 0843-03092, Balboa, Ancón, PANAMÁ

The success of ex situ survival assurance populations as tools for amphibian conservation depends on the health and reproductive success of founder populations. Necropsy examination and histopathology of animals that die in assurance populations are useful for the identification of population-limiting disease problems and can help to direct applied research efforts in areas such as amphibian husbandry and nutrition. This study reviewed postmortem findings in 167 frogs from 13 species that died in a large Panamanian rescue and survival assurance population between 2006 and 2011. Common problems identified in long-term captive animals, especially in Atelopus species, were epithelial squamous metaplasia suggestive of vitamin A deficiency and a polycystic nephropathy resembling lesions seen in laboratory animals with electrolyte imbalances. Metabolic bone disease was a significant contributor to morbidity in captive-bred juvenile frogs of Gastrotheca cornuta, Hemiphractus fasciatus, and Hylomantis lemur. Findings common to multiple species included poor overall nutritional condition that was sometimes attributable to maladaptation to captive husbandry and epidermal hyperplasia and hyperkeratosis possibly reflecting environmental skin irritation. Infectious diseases and endoparasitism were most common in recently captured animals and included chytridiomycosis and Rhabdias sp. lungworms. Applied research efforts to improve sustainability of survival assurance populations should focus on elucidating optimal husbandry practices for diverse species, improving methods for nutritional supplementation of cultured insects and examination of the role of water composition in disease development.

Microbial communities can augment host immune responses and probiotic therapies are under development to prevent or treat diseases of humans, crops, livestock, and wildlife including an emerging fungal disease of amphibians, chytridiomycosis. However, little is known about the stability of host-associated microbiota, or how the microbiota is structured by innate immune factors including antimicrobial peptides (AMPs) abundant in the skin secretions of many amphibians. Thus, conservation medicine including therapies targeting the skin will benefit from investigations of amphibian microbial ecology that provide a model for vertebrate host-symbiont interactions on mucosal surfaces. Here, we tested whether the cutaneous microbiota of Panamanian rocket frogs, Colostethus panamansis, was resistant to colonization or altered by treatment. Under semi-natural outdoor mesocosm conditions in Panama, we exposed frogs to one of three treatments including: (1) probiotic - the potentially beneficial bacterium Lysinibacillus fusiformis, (2) transplant - skin washes from the chytridiomycosis-resistant glass frog Espadarana prosoblepon, and (3) control - sterile water. Microbial assemblages were analyzed by a culture-independent T-RFLP analysis. We found that skin microbiota of C. panamansis was resistant to colonization and did not differ among treatments, but shifted through time in the mesocosms. We describe regulation of host AMPs that may function to maintain microbial community stability. Colonization resistance was metabolically costly and microbe-treated frogs lost 7-12% of body mass. The discovery of strong colonization resistance of skin microbiota suggests a well-regulated, rather than dynamic, host-symbiont relationship, and suggests that probiotic therapies aiming to enhance host immunity may require an approach that circumvents host mechanisms maintaining equilibrium in microbial communities.

Amphibians constitute a diverse yet still incompletely characterized clade of vertebrates, in which new species are still being discovered and described at a high rate. Amphibians are also increasingly endangered, due in part to disease‐driven threats of extinctions. As an emergency response, conservationists have begun ex situ assurance colonies for priority species. The abundance of cryptic amphibian diversity, however, may cause problems for ex situ conservation. In this study we used a DNA barcoding approach to survey mitochondrial DNA (mtDNA) variation in captive populations of 10 species of Neotropical amphibians maintained in an ex situ assurance programme at El Valle Amphibian Conservation Center (EVACC) in the Republic of Panama. We combined these mtDNA sequences with genetic data from presumably conspecific wild populations sampled from across Panama, and applied genetic distance‐based and character‐based analyses to identify cryptic lineages. We found that three of ten species harboured substantial cryptic genetic diversity within EVACC, and an additional three species harboured cryptic diversity among wild populations, but not in captivity. Ex situ conservation efforts focused on amphibians are therefore vulnerable to an incomplete taxonomy leading to misidentification among cryptic species. DNA barcoding may therefore provide a simple, standardized protocol to identify cryptic diversity readily applicable to any amphibian community.

We describe a new species of Ecnomiohyla from the vicinity of El Valle de Anton, Cocle, Panama. This is a large species that differs from similar species in the genus by details of the prepollex, webbing, and by the presence of a distinct expanded crista lateralis with medial proximal point. We Provide descriptions of the adult and subadult, as well as the tadpole. We provide natural history information including observations of individuals gliding from the forest canopy, reproduction in tree holes, and male territoriality and care of the tadpoles. This species is currently known only from the immediate vicinity of El Valle de Anton, and we have observed numbers of this species in the wild to decrease dramatically following the recent epidemic of amphibian chytridiomycosis in the region.