Microreserves are an important tool for amphibian conservation.

Initiatives to protect 30% of Earth by 2030 prompt evaluation of how to efficiently target shortcomings in the global protected area (PA) network. Focusing on amphibians, the most vulnerable vertebrate class, we illustrate the conservation value of microreserves, a term we employ here to refer to reserves of <10 km2. We report that the network continues to under-represent threatened amphibians and that, despite this clear shortcoming in land-based conservation, the creation of PAs protecting amphibians slowed after 2010. By proving something previously assumed-that amphibians generally have smaller ranges than other terrestrial vertebrates-we demonstrate that microreserves could protect a substantial portion of many amphibian ranges, particularly threatened species. We find existing microreserves are capable of hosting an amphibian species richness similar to PAs 1000-10,00X larger, and we show that amphibians' high beta diversity means that microreserves added to a growing PA network cover amphibian species 1.5-6x faster than larger size categories. We propose that stemming global biodiversity loss requires that we seriously consider the conservation potential of microreserves, using them to capture small-range endemics that may otherwise be omitted from the PA network entirely.

Water availability and biological interactions shape amphibian abundance and diversity in Mediterranean temporary rivers.

Amphibians, the most threatened vertebrates globally, face risks due to climate change, habitat loss, and fragmentation. Their sensitivity to environmental changes highlights their importance as ecological indicators. Temporary rivers, influenced by geological, climatic, and anthropogenic factors, play a critical role in shaping biodiversity and community structure. Some species of amphibians may be adapted to these temporary waters, a fact reflected in their life cycles and various biological traits. However, to develop effective conservation strategies for amphibians, it is essential to address the knowledge gaps surrounding the complex interactions between biological dynamics and fluvial habitat conditions. In this study, we investigated how trophic interactions between amphibians and other aquatic organisms (diatoms, macroinvertebrates, and fish), coupled with environmental factors (water availability and riparian structure), can affect amphibian abundance and diversity in temporary rivers. The study was conducted in a Mediterranean river network located in Sant Llorenç del Munt i l'Obac Natural Park (Catalonia, Spain). Our expectations were that habitats suitable for egg deposition, lacking predators (e.g. tadpole-predators and fish), and abundant in food sources would likely support higher amphibian abundance and diversity. However, water availability was identified as a crucial factor shaping abundance and diversity in the studied amphibian communities, even if it correlated with fish presence, and especially impacting amphibian species usually linked to permanent water bodies. Concerning biotic interactions, while our results suggested that amphibian populations in temporary rivers are more dependent on top-down than bottom-up interactions, the presence of aquatic predators was not as conclusive as expected, suggesting that in temporary rivers the fish-avoiding amphibian species can survive using microhabitats or breeding opportunities linked to natural river dynamics. Overall, our findings highlight the importance of considering multi-trophic interactions, hydroperiod and habitat heterogeneity in temporary river ecosystems for effective amphibian conservation.

PENTASTOMES IN AUSTRALIAN REPTILES AND AMPHIBIANS: A REVIEW OF THE HISTORY AND A CHECKLIST OF RECORDS.

This paper provides a summary of new and revised records of pentastomes published since 1985 and also presents a checklist of all pentastome records from Australian reptiles and amphibians. The need to identify pentastome species, through both morphological and molecular characterization, is highlighted to enable a determination of the true diversity of pentastome species and their distribution within amphibians and reptiles in Australia.

Scale of unregulated international trade in Australian reptiles and amphibians.

Reptiles and amphibians are popular in the exotic pet trade, where Australian species are valued for their rarity and uniqueness. Despite a near-complete ban on the export of Australian wildlife, smuggling and subsequent international trade frequently occur in an unregulated and unmonitored manner. In 2022, Australia listed over 100 squamates in Appendix III of the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) to better monitor this trade. We investigated current trade and assessed the value of this Australian CITES listing using web-scraping methods to monitor the online pet trade in Australian reptiles and amphibians, with additional data from published papers, trade databases, and seizure records. Despite the export ban, we identified 170 endemic herpetofauna (reptile and amphibian) species in international trade, 33 of which were not recorded previously in the international market, including 6 newly recorded genera. Ninety-two traded species were included in CITES appendices (59 added in 2022), but at least 78 other traded species remained unregulated. Among these, 5 of the 10 traded threatened species were unlisted, and we recommend they be considered for inclusion in CITES Appendix III. We also recommend the listing of all Diplodactylidae genera in Appendix III. Despite this family representing the greatest number of Australian species in trade, only one genus (of 7 traded) was included in the recent CITES amendments. Overall, a large number of Australian reptile and amphibian species are traded internationally and, although we acknowledge the value of Australia's recent CITES listing, we recommend the consideration of other taxa for similar inclusion in CITES.

Escala del mercado internacional no regulado de reptiles y anfibios australianos Resumen Los reptiles y anfibios son populares en el comercio de mascotas exóticas, en el que las especies australianas son valoradas por su rareza y singularidad. A pesar de la prohibición casi total de la exportación de fauna silvestre australiana, el contrabando y el comercio internacional posterior se producen con frecuencia de forma no regulada y no supervisada. En 2022, Australia incluyó más de 100 escamosos en el apéndice III de la Convención sobre el Comercio Internacional de Especies Amenazadas de Fauna y Flora Silvestres (CITES) para controlar mejor este comercio. Investigamos el comercio actual y evaluamos el valor de esta inclusión en CITES con métodos de raspado web para monitorear el comercio virtual de reptiles y anfibios australianos como mascotas, con datos adicionales de artículos publicados, bases de datos comerciales y registros de incautaciones. A pesar de la prohibición de las exportaciones, identificamos 170 especies endémicas de herpetofauna (reptiles y anfibios) en el comercio internacional, 33 de las cuales no se habían registrado previamente en el mercado internacional, incluidos 6 géneros registrados recientemente. Noventa y dos especies comercializadas se incluyeron en los apéndices de CITES (59 añadidas en 2022), pero al menos otras 78 especies comercializadas permanecieron sin regular. Entre ellas, cinco de las diez especies amenazadas comercializadas no estaban incluidas y recomendamos que se considere su inclusión en el apéndice III de CITES. También recomendamos la inclusión de todos los géneros de Diplodactylidae en el apéndice III. A pesar de que esta familia representa el mayor número de especies australianas en el comercio, sólo un género (de 7 comercializados) fue incluido en las recientes enmiendas de CITES. En general, un gran número de especies de reptiles y anfibios australianos son objeto de comercio internacional y, aunque reconocemos el valor de la reciente inclusión de Australia en CITES, recomendamos que se consideren otros taxones para su similar inclusión.

Endocrine disruption assessment in aquatic vertebrates - Identification of substance-induced thyroid-mediated effect patterns.

According to the World Health Organisation and European Commission definitions, substances shall be considered as having endocrine disrupting properties if they show adverse effects, have endocrine activity and the adverse effects are a consequence of the endocrine activity (using a weight-of-evidence approach based on biological plausibility), unless the adverse effects are not relevant to humans or non-target organisms at the (sub)population level. To date, there is no decision logic on how to establish endocrine disruption via the thyroid modality in non-mammalian vertebrates. This paper describes an evidence-based decision logic compliant with the integrated approach to testing and assessment (IATA) concept, to identify thyroid-mediated effect patterns in aquatic vertebrates using amphibians as relevant models for thyroid disruption assessment. The decision logic includes existing test guidelines and methods and proposes detailed considerations on how to select relevant assays and interpret the findings. If the mammalian dataset used as the starting point indicates no thyroid concern, the Xenopus Eleutheroembryonic Thyroid Assay allows checking out thyroid-mediated activity in non-mammalian vertebrates, whereas the Amphibian Metamorphosis Assay or its extended, fixed termination stage variant inform on both thyroid-mediated activity and potentially population-relevant adversity. In evaluating findings, the response patterns of all assay endpoints are considered, including the direction of changes. Thyroid-mediated effect patterns identified at the individual level in the amphibian tests are followed by mode-of-action and population relevance assessments. Finally, all data are considered in an overarching weight-of-evidence evaluation. The logic has been designed generically and can be adapted, e.g. to accommodate fish tests once available for thyroid disruption assessments. It also ensures that all scientifically relevant information is considered, and that animal testing is minimised. The proposed decision logic can be included in regulatory assessments to facilitate the conclusion on whether substances meet the endocrine disruptor definition for the thyroid modality in non-mammalian vertebrates.

Exploring Codon Usage Patterns and Influencing Factors in Ranavirus DNA Polymerase Genes.

Ranaviruses, members of the genus Ranavirus within the family Iridoviridae, have become a significant concern for amphibian populations globally, along with other cold-blooded vertebrates, due to their emergence as a significant threat. We employed bioinformatics tools to examine the codon usage patterns in 61 DNA pol genes from Ranavirus, Lymphocystivirus, Megalocytivirus, and two unclassified ranaviruses, as no prior studies had been conducted on this topic. The results showed a slight or low level of codon usage bias (CUB) in the DNA pol genes of Ranavirus. Relative synonymous codon usage (RSCU) analysis indicated that the predominant codons favored in Ranavirus DNA pol genes terminate with C or G. Correlation analysis examining nucleotide content, third codon position, effective number of codons (ENC), correspondence analysis (COA), Aroma values, and GRAVY values indicated that the CUB across DNA pol genes could be influenced by both mutation pressure and natural selection. The neutrality plot indicated that natural selection is the primary factor driving codon usage. Furthermore, the analysis of the codon adaptation index (CAI) illustrated the robust adaptability of Ranavirus DNA pol genes to their hosts. Analysis of the relative codon deoptimization index (RCDI) suggested that Ranavirus DNA pol genes underwent greater selection pressure from their hosts. These findings will aid in comprehending the factors influencing the evolution and adaptation of Ranavirus to its hosts.

Scanning amplicons with CRISPR-Dx detects endangered amphibians in environmental DNA.

More efficient methods for extensive biodiversity monitoring are required to support rapid measures to address the biodiversity crisis. While environmental DNA (eDNA) metabarcoding and quantitative PCR (qPCR) methods offer advantages over traditional monitoring approaches, their large-scale application is limited by the time and labour required for developing assays and/or for analysis. CRISPR (clustered regularly interspaced short palindromic repeats) diagnostic technologies (Dx) may overcome some of these limitations, but they have been used solely with species-specific primers, restricting their versatility for biodiversity monitoring. Here, we demonstrate the feasibility of designing species-specific CRISPR-Dx assays in silico within a short metabarcoding fragment using a general primer set, a methodology we term 'ampliscanning', for 18 of the 22 amphibian species in Switzerland. We sub-selected nine species, including three classified as regionally endangered, to test the methodology using eDNA sampled from ponds at nine sites. We compared the ampliscanning detections to data from traditional monitoring at these sites. Ampliscanning was successful at detecting target species with different prevalences across the landscape. With only one visit, we detected more species per site than three traditional monitoring visits (visual and acoustic detections by trained experts), in particular more elusive species and previously undocumented but expected populations. Ampliscanning detected 25 species/site combinations compared to 12 with traditional monitoring. Sensitivity analyses showed that larger numbers of field visits and PCR replicates are more important for reliable detection than many technical replicates at the CRISPR-Dx assay level. Given the reduced sampling and analysis effort, our results highlight the benefits of eDNA and CRISPR-Dx combined with universal primers for large-scale monitoring of multiple endangered species across landscapes to inform conservation measures.

The future of amphibian immunology: Opportunities and challenges.

Historically, amphibians have been essential to our understanding of vertebrate biology and animal development. Because development from egg to tadpole to adult frog can be directly observed, amphibians contributed greatly to our understanding of not only vertebrate animal development but also the development of the immune system. The South African clawed frog (Xenopus laevis) has been key to many of these findings. For example, using Xenopus as a model, the comparative immunology community learned about the contribution of hematopoietic stem cells to development of the immune system and about the diversity of antibodies, B cells, T cells and antigen presenting cells. Amphibians offer many advantages as unique potential model systems to address questions about immune skin interactions, host responses to mycobacteria, the diverse functions of interferons, and immune and mucosal interactions. However, there are also many challenges to advance the research including the lack of specific reagents and well annotated genomes of diverse species. While much is known, many important questions remain. The aim of this short commentary is to look to the future of comparative immunology of amphibians as a group. By identifying some important questions or "information-deficit" areas of research, I hope to pique the interest of younger developing scientists and persuade funding agencies to continue to support comparative immunology studies including those of amphibians.

Countrywide screening supports model-based predictions of the distribution of Batrachochytrium dendrobatidis in Ukraine.

The chytrid Batrachochytrium dendrobatidis (Bd) is a widespread fungus causing amphibian declines across the globe. Although data on Bd occurrence in Eastern Europe are scarce, a recent species distribution model (SDM) for Bd reported that western and north-western parts of Ukraine are highly suitable to the pathogen. We verified the SDM-predicted range of Bd in Ukraine by sampling amphibians across the country and screening for Bd using qPCR. A total of 446 amphibian samples (tissue and skin swabs) from 11 species were collected from 36 localities. We obtained qPCR-positive results for 33 samples including waterfrogs (Pelophylax esculentus complex) and fire- and yellow-bellied toads (Bombina spp.) from 8 localities. We found that Bd-positive localities had significantly higher predicted Bd habitat suitability than sites that were pathogen-free. Amplification and sequencing of the internal transcribed spacer (ITS) region of samples with the highest Bd load revealed matches with ITS haplotypes of the globally distributed BdGPL strain, and a single case of the BdASIA-2/BdBRAZIL haplotype. We found that Bd was non-randomly distributed across Ukraine, with infections present in the western and north-central forested peripheries of the country with a relatively cool, moist climate. On the other hand, our results suggest that Bd is absent or present in low abundance in the more continental central, southern and eastern regions of Ukraine, corroborating the model-predicted distribution of chytrid fungus. These areas could potentially serve as climatic refugia for Bd-susceptible amphibian hosts.

Host Jump of an Exotic Fish Rhabdovirus into a New Class of Animals Poses a Disease Threat to Amphibians.

Spring viremia of carp virus (SVCV) is a rhabdovirus that primarily infects cyprinid finfishes and causes a disease notifiable to the World Organization for Animal Health. Amphibians, which are sympatric with cyprinids in freshwater ecosystems, are considered non-permissive hosts of rhabdoviruses. The potential host range expansion of SVCV in an atypical host species was evaluated by testing the susceptibility of amphibians native to the Pacific Northwest. Larval long-toed salamanders Ambystoma macrodactylum and Pacific tree frog Pseudacris regilla tadpoles were exposed to SVCV strains from genotypes Ia, Ib, Ic, or Id by either intraperitoneal injection, immersion, or cohabitation with virus-infected koi Cyprinus rubrofuscus. Cumulative mortality was 100% for salamanders injected with SVCV, 98-100% for tadpoles exposed to virus via immersion, and 0-100% for tadpoles cohabited with SVCV-infected koi. Many of the animals that died exhibited clinical signs of disease and SVCV RNA was found by in situ hybridization in tissue sections of immersion-exposed tadpoles, particularly in the cells of the gastrointestinal tract and liver. SVCV was also detected by plaque assay and RT-qPCR testing in both amphibian species regardless of the virus exposure method, and viable virus was detected up to 28 days after initial exposure. Recovery of infectious virus from naïve tadpoles cohabited with SVCV-infected koi further demonstrated that SVCV transmission can occur between classes of ectothermic vertebrates. Collectively, these results indicated that SVCV, a fish rhabdovirus, can be transmitted to and cause lethal disease in two amphibian species. Therefore, members of all five of the major vertebrate groups (mammals, birds, reptiles, fish, and amphibians) appear to be vulnerable to rhabdovirus infections. Future research studying potential spillover and spillback infections of aquatic rhabdoviruses between foreign and domestic amphibian and fish species will provide insights into the stressors driving novel interclass virus transmission events.

Conservation of more evolutionary unique amphibian communities in Türkiye: The role of protected areas.

The alarming decline of amphibians, sometimes marked by sudden extinctions, underlines the urgent need for increased conservation efforts. Conservationists recognize that more action, particularly the setting of national targets, is needed to ensure the future persistence and recovery of species and habitats. Protecting habitats that harbor evolutionarily diverse species preserves divergent genetic information within ecosystems. Türkiye holds 36 amphibian species at the intersection of two continents, creating three biodiversity hotspots and phylogenetic transitional areas. In this study, we aimed to determine the hotspot regions and to evaluate the effectiveness of the protected areas in Türkiye in preserving amphibian populations. First, we estimated four community indexes (species richness and three evolutionary distinctiveness measures) for amphibian communities in Türkiye divided into 371 grid cells with a ca 50 × 50 km size. Then, the spatial extent of protected areas is evaluated from two perspectives: current (has a protection status) and candidate protected areas (Key Biodiversity Areas, not protected) coverage in those grid cells. Finally, these two approaches' effectiveness in protecting areas was assessed by modeling four diversity metrics using GLS models. Current protected areas protect about 6% of the total amphibian distribution in Türkiye, while Key Biodiversity Areas would cover 30% if declared protected areas. We estimated that the coastal areas of Türkiye are identified as hotspots based on the four measured amphibian community indexes. Our study also highlights that Key Biodiversity Areas (KBAs) can contribute to conserving high levels of amphibian richness and evolutionary distinctiveness of species across Türkiye. However, existing protected areas (PAs) networks were insufficient to protect amphibians.

Effectiveness of permanent drift fences in reducing roadkill risk of amphibians.

Roads are an important source of human economic progress, but also a threat to wildlife populations and natural habitats. Roads are responsible for the direct mortality of hundreds of millions of animals worldwide, with special negative effects for amphibians. Since the middle of the twentieth century, various types of mitigation measures have been constructed to reduce the negative effects of roads. However, despite the large availability of potential solutions designed for this purpose, there is still a knowledge gap about their effectiveness for amphibians. This study analysed whether permanent concrete drift fences reduced the roadkill risk for amphibians. We applied a before-after-control-impact (BACI) design in two road segments with concrete drift fences for amphibians. We recorded amphibians on these road segments three years before and three years after the fence installation. We further tested whether the presence of these mitigation measures transferred the animals to sites adjacent to the drift fences, creating new potential mortality aggregation sites (fence-end effect). Our results show a significant reduction in the number of amphibians reaching the sites with the drift fences. We were, however, unable to demonstrate the potential movement route transference, as our results were inconclusive. Despite the increase in amphibian numbers at the control sites in the first year after fence installation, the following two years presented similar amphibian numbers as the pre-fence years. We recognise the importance of permanent drift fences in reducing the mortality of amphibian populations; however, we encourage future studies to include tunnel-crossing data as well, to truly unveil the roadkill reduction power of amphibian mitigation measures, while maintaining or increasing connectivity between roadside habitats.

Assessing the Efficacy of Protease Inactivation for the Preservation of Bioactive Amphibian Skin Peptides.

The skin of amphibians is a rich source of peptides with a wide range of biological activities. They are stored in secretory granules in an inactive form. Upon stimulation, they are secreted together with proteases into the skin. Once activated, they rapidly exert their biological effects, including fighting microorganisms and predators, while their excess is immediately destroyed by the released proteases. To keep bioactive peptides in their initial form, it is necessary to inhibit these enzymes. Several inhibitors for this purpose have previously been mentioned; however, there has not been any reliable comparison of their efficiency so far. Here, we studied the efficiency of methanol and hydrochloric and formic acids, as well as phenylmethylsulfonyl fluoride, in the inhibition of nine frog peptides with the known sequence, belonging to five families in the secretion of Pelophylax esculentus. The results demonstrated that methanol had the highest inhibitory efficiency, while phenylmethylsulfonyl fluoride was the least efficient, probably due to its instability in aqueous media. Possible cleavages between certain amino acid residues in the sequence were established for each of the inhibitors. These results may be helpful for future studies on the nature of proteases and on prediction of the possible cleavage sites in novel peptides.

Phylotranscriptomic relationships of the Oophila clade of green algae associated to amphibian egg masses.

Green algae usually assigned to the genus Oophila are known to colonize egg capsules of amphibian egg masses across the Nearctic and Palearctic regions. We study the phylogenetic relationships of these algae using a phylotranscriptomic data set of 76 protein-coding single-copy nuclear genes. Our data set includes novel RNAseq data for six amphibian-associated and five free-living green algae, and draft genomes of two of the latter. Within the Oophila clade (nested within Moewusinia), we find samples from two European frogs (Rana dalmatina and R. temporaria) closely related to those of the North American frog R. aurora (Oophila subclade III). An isolate from the North American R. sylvatica (subclade IV) appears to be sister to the Japanese isolate from the salamander Hynobius nigrescens (subclade J1), and subclade I algae from Ambystoma maculatum are sister to all other lineages in the Oophila clade. Two free-living algae (Chlamydomonas nasuta and Cd. pseudogloeogama) are nested within the Oophila clade, and a strain of the type species of Chlorococcum (Cc. infusionum) is related to this assemblage. Our phylotranscriptomic tree suggests that recognition of different species within the Oophila clade ("clade B" of earlier studies) is warranted, and calls for a comprehensive taxonomic revision of Moewusinia.

The impact of chemical pollution across major life transitions: a meta-analysis on oxidative stress in amphibians.

Among human actions threatening biodiversity, the release of anthropogenic chemical pollutants which have become ubiquitous in the environment, is a major concern. Chemical pollution can induce damage to macromolecules by causing the overproduction of reactive oxygen species, affecting the redox balance of animals. In species undergoing metamorphosis (i.e. the vast majority of the extant animal species), antioxidant responses to chemical pollution may differ between pre- and post-metamorphic stages. Here, we meta-analysed (N = 104 studies, k = 2283 estimates) the impact of chemical pollution on redox balance across the three major amphibian life stages (embryo, tadpole, adult). Before metamorphosis, embryos did not experience any redox change while tadpoles activate their antioxidant pathways and do not show increased oxidative damage from pollutants. Tadpoles may have evolved stronger defences against pollutants to reach post-metamorphic life stages. In contrast, post-metamorphic individuals show only weak antioxidant responses and marked oxidative damage in lipids. The type of pollutant (i.e. organic versus inorganic) has contrasting effects across amphibian life stages. Our findings show a divergent evolution of the redox balance in response to pollutants across life transitions of metamorphosing amphibians, most probably a consequence of differences in the ecological and developmental processes of each life stage.

Evidence for a metal disease refuge: The amphibian-killing fungus (Batrachochytrium dendrobatidis) is inhibited by environmentally-relevant concentrations of metals tolerated by amphibians.

The amphibian-killing fungus Batrachochytrium dendrobatidis (Bd) has caused substantial declines in Bd-susceptible amphibian species worldwide. However, some populations of Bd-susceptible frogs have managed to survive at existing metal-polluted sites, giving rise to the hypothesis that frogs might persist in the presence of Bd if Bd is inhibited by metals at concentrations that frogs can tolerate. We tested this hypothesis by measuring the survival of Bd zoospores, the life stage that infects amphibians, and calculated the LC50 after exposure to environmentally-relevant elevated concentrations of copper (Cu), zinc (Zn), and their combination (Cu + Zn) in two repeated 4-day acute exposure runs. We also measured the chronic sensitivity of Bd to these metals over three generations by measuring the number of colonies and live zoospores and calculating EC50 concentrations after 42 days of exposure. We then compared acute and chronic sensitivity of Bd with amphibian sensitivities by constructing species sensitivity distributions (SSDs) using LC50 and EC50 data obtained from the literature. Acute sensitivity data showed that Bd zoospore survival decreased with increasing metal concentrations and exposure durations relative to the control, with the highest LC50 values for Cu and Zn being 2.5 µg/L and 250 µg/L, respectively. Chronic exposures to metals resulted in decreased numbers of Bd colonies and live zoospores after 42 days, with EC50 values of 0.75 µg/L and 1.19 µg/L for Cu and Zn, respectively. Bd zoospore survival was 10 and 8 times more sensitive to Cu and Zn, respectively in acute, and 2 and 5 times more sensitive to Cu and Zn in chronic exposure experiments than the most sensitive amphibian species recorded. Our findings are consistent with the hypothesis that metals in existing metal-polluted sites may have a greater impact on Bd relative to amphibians' performance, potentially enabling Bd-susceptible amphibians to persist with Bd at these sites.

Mountain caves of the central region of Veracruz: A vertebrate biodiversity reservoir in a Neotropical hotspot.

The mountain region of central Veracruz, Mexico hosts a large system of karst and volcanic caves that are unexplored. In particular, the vertebrates that inhabit these subterranean ecosystems are unknown. This study evaluated the diversity of mammals, birds, reptiles, amphibians, and fish in three environments (euphotic, disphotic, and aphotic) of 16 caves of different geological origin (12 karst caves and 4 volcanic caves) distributed along an altitudinal gradient (300-2400 m a.s.l.). We found a richness of 242 vertebrate species (184 birds, 30 mammals, 15 reptiles, 12 amphibians, and 1 fish) and an abundance of a total of 11,323 individuals (4,969 mammals, 6,483 birds, 36 reptiles, 27 amphibians, and 5 fish). The richness of all vertebrate classes was higher in karst than in volcanic caves. Vertebrate diversity was also higher at mid-altitudes between 600-899 m a.s.l. Diversity varied between environments, where bird and reptile richness was higher in the euphotic environment, while mammal and amphibian diversity was higher in the aphotic environment. The similarity in the composition of vertebrate species does not depend on the distance between karstic and volcanic caves. Volcanic and karst caves shared on average up to 70% and 55% of vertebrate species, which indicates that only 30% and 45% of species, respectively, is different in each cave type. Given the vulnerability and fragility of these subterranean ecosystems, as well as the important diversity that they contain, we recommend including the caves of the central region of Veracruz in the conservation agenda of local governments and communities. Community-based conservation can help ensure the presence of vertebrate species in the caves of this region.

Recent Advancement in Novel Wound Healing Therapies by Using Antimicrobial Peptides Derived from Humans and Amphibians.

The skin is the biggest organ in the human body. It is the first line of protection against invading pathogens and the starting point for the immune system. The focus of this review is on the use of amphibian-derived peptides and antimicrobial peptides (AMPs) in the treatment of wound healing. When skin is injured, a chain reaction begins that includes inflammation, the formation of new tissue, and remodelling of existing tissue to aid in the healing process. Collaborating with non-immune cells, resident and recruited immune cells in the skin remove foreign invaders and debris, then direct the repair and regeneration of injured host tissues. Restoration of normal structure and function requires the healing of damaged tissues. However, a major issue that slows wound healing is infection. AMPs are just one type of host-defense chemicals that have developed in multicellular animals to regulate the immune response and limit microbial proliferation in response to various types of biological or physical stress. Therefore, peptides isolated from amphibians represent novel therapeutic tools and approaches for regenerating damaged skin. Peptides that speed up the healing process could be used as therapeutic lead molecules in future research into novel drugs. AMPs and amphibian-derived peptides may be endogenous mediators of wound healing and treat non-life-threatening skin and epithelial lesions. Thus, the present article was drafted with to incorporate different peptides used in wound healing, their method of preparation and routes of administration.

Centrifugation is an effective and inexpensive way to determine Batrachochytrium dendrobatidis quantity in water samples with low turbidity.

Batrachochytrium dendrobatidis (Bd) is a pathogenic chytrid fungus that is particularly lethal for amphibians. Bd can extirpate amphibian populations within a few weeks and remain in water in the absence of amphibian hosts. Most efforts to determine Bd presence and quantity in the field have focused on sampling hosts, but these data do not give us a direct reflection of the amount of Bd in the water, which are useful for parameterizing disease models, and are not effective when hosts are absent or difficult to sample. Current methods for screening Bd presence and quantity in water are time, resource, and money intensive. Here, we developed a streamlined method for detecting Bd in water with low turbidity (e.g., water samples from laboratory experiments and relatively clear pond water from a natural lentic system). We centrifuged water samples with known amounts of Bd to form a pellet and extracted the DNA from that pellet. This method was highly effective and the resulting concentrations across all tested treatments presented a highly linear relationship with the expected values. While the experimentally derived values were lower than the inoculation doses, the values were highly correlated and a conversion factor allows us to extrapolate the actual Bd concentration. This centrifuge-based method is effective, repeatable, and would greatly expand the domain of tractable questions to be explored in the field of Bd ecology. Importantly, this method increases equity in the field, because it is time- and cost-efficient and requires few resources.

Drivers of Intraspecific Variation in Thermal Traits and Their Importance for Resilience to Global Change in Amphibians.

Intraspecific variation can be as great as variation across species, but the role of intraspecific variation in driving local and large-scale patterns is often overlooked, particularly in the field of thermal biology. In amphibians, which depend on environmental conditions and behavior to regulate body temperature, recognizing intraspecific thermal trait variation is essential to comprehensively understanding how global change impacts populations. Here, we examine the drivers of micro- and macrogeographical intraspecific thermal trait variation in amphibians. At the local scale, intraspecific variation can arise via changes in ontogeny, body size, and between the sexes, and developmental plasticity, acclimation, and maternal effects may modulate predictions of amphibian performance under future climate scenarios. At the macrogeographic scale, local adaptation in thermal traits may occur along latitudinal and elevational gradients, with seasonality and range-edge dynamics likely playing important roles in patterns that may impact future persistence. We also discuss the importance of considering disease as a factor affecting intraspecific variation in thermal traits and population resilience to climate change, given the impact of pathogens on thermal preferences and critical thermal limits of hosts. Finally, we make recommendations for future work in this area. Ultimately, our goal is to demonstrate why it is important for researchers to consider intraspecific variation to determine the resilience of amphibians to global change.