ABSTRACT
Chemical pollution, land cover change, and climate change have all been established as important drivers of amphibian reproductive success and phenology. However, little is known about the relative impacts of these anthropogenic stressors, nor how they may interact to alter amphibian population dynamics. Addressing this gap in our knowledge is important, as it allows us to identify and prioritise the most needed conservation actions. Here, we use long-term datasets to investigate landscape-scale drivers of variation in the reproductive success and phenology of UK Common frog (Rana temporaria) populations. Consistent with predictions, we found that increasing mean temperatures resulted in earlier initialisation of spawning, and earlier hatching, but these relationships were not consistent across all sites. Lower temperatures were also linked to increased spawn mortality. However, temperature increases were also strongly correlated with increases in urban area, arable area, and nitrate levels in the vicinity of spawning grounds. As with spawning and hatching, there was marked spatial variation in spawn mortality trends, where some sites exhibited steady increases over time in the proportion of dead or diseased spawn. These findings support previous work linking warming temperatures to shifts in timing of amphibian breeding, but also highlight the importance of assessing the effect of land use change and pollution on wild amphibian populations. These results have implications for our understanding of the response of wild amphibian populations to climate change, and the management of human-dominated landscapes for declining wildlife populations.
Subject(s)
Climate Change , Rana temporaria , Reproduction , Temperature , Animals , Reproduction/physiology , Population DynamicsABSTRACT
Microplastics (MPs), tiny plastic particles less than 5 mm in size, have emerged as a common and worrying pollutant in marine, freshwater, and terrestrial environments worldwide. In this study, we revealed the microplastic exposure of two endemic newt species for Türkiye. We found that polyethylene terephthalate (PET) was the predominant microplastic polymer type in both species, with the blue fiber shape in particular. We also found that there was a negative correlation between microplastic size and gastrointestinal tract (GIT) weight, but there was no significant difference between body length and GIT weight of both species. Our findings might be surprising as the studied species live in natural spring waters in remote, high-altitude areas. However, the detection of water bottles in their habitats appears to be the reason for their exposure to microplastic pollution. Therefore, reducing the use of single-use plastics is predicted to contribute to the conservation of these endemic newts.
ABSTRACT
We compared the effects of lambda-cyhalothrin as the pure active ingredient and as a formulated product (Zero®), on the larval stage of the autochthonous species Boana pulchella. We evaluated ecotoxicological endpoints, behavioral and developmental alterations, and the biochemical detoxifying, neurotoxic, and oxidative stress responses, covering a wide concentration range from environmental to high application levels. Both pyrethroid preparations displayed similar ecotoxicity (median lethal concentration of ~0.5 mg/L), with the lethal effect of Zero® being more pronounced than that of the active ingredient. Sublethal behavioral alterations in natatory activity were observed at 1000 times lower concentrations, indicating the ecological hazard of tadpole exposure to this pyrethroid at environmentally relevant concentrations. Biochemical endpoints in B. pulchella larvae showed significant responses to lambda-cyhalothrin in the ng/L range; these responses were different for the pure or the formulated product, and they were variable at higher concentrations. Principal components analysis confirmed the prevalence of biochemical responses as early endpoints at the lowest lambda-cyhalothrin concentrations; the Integrated Biomarker Response Index proportionally increased with pyrethroid concentration in a similar way for the pure and the formulated products. We conclude that lambda-cyhalothrin is of concern from an environmental perspective, with particular emphasis on autochthonous anuran development. The battery of biochemical biomarkers included in our study showed a consistent integrated biomarker response, indicating that this is a potent tool for monitoring impacts on amphibians. Environ Toxicol Chem 2024;00:1-11. © 2024 SETAC.
ABSTRACT
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.
Subject(s)
Amphibians , Skin , Wound Healing , Wound Healing/drug effects , Animals , Humans , Amphibians/immunology , Skin/drug effects , Skin/pathology , Skin/injuries , Antimicrobial Peptides/pharmacology , Antimicrobial Peptides/chemistry , Antimicrobial Peptides/therapeutic use , Antimicrobial Cationic Peptides/pharmacology , Antimicrobial Cationic Peptides/therapeutic use , Antimicrobial Cationic Peptides/chemistry , Amphibian Proteins/pharmacology , Amphibian Proteins/chemistry , Amphibian Proteins/therapeutic useABSTRACT
Finding effective pathogen mitigation strategies is one of the biggest challenges humans face today. In the context of wildlife, emerging infectious diseases have repeatedly caused widespread host morbidity and population declines of numerous taxa. In areas yet unaffected by a pathogen, a proactive management approach has the potential to minimize or prevent host mortality. However, typically critical information on disease dynamics in a novel host system is lacking, empirical evidence on efficacy of management interventions is limited, and there is a lack of validated predictive models. As such, quantitative support for identifying effective management interventions is largely absent, and the opportunity for proactive management is often missed. We considered the potential invasion of the chytrid fungus, Batrachochytrium salamandrivorans (Bsal), whose expected emergence in North America poses a severe threat to hundreds of salamander species in this global salamander biodiversity hotspot. We developed and parameterized a dynamic multistate occupancy model to forecast host and pathogen occurrence, following expected emergence of the pathogen, and evaluated the response of salamander populations to different management scenarios. Our model forecasted that taking no action is expected to be catastrophic to salamander populations. Proactive action was predicted to maximize host occupancy outcomes relative to wait-and-see reactive management, thus providing quantitative support for proactive management opportunities. The eradication of Bsal was unlikely under all the evaluated management options. Contrary to our expectations, even early pathogen detection had little effect on Bsal or host occupancy outcomes. Our results provide quantitative support that proactive management is the optimal strategy for promoting persistence of disease-threatened salamander populations. Our approach fills a critical gap by defining a framework for evaluating management options prior to pathogen invasion and can thus serve as a template for addressing novel disease threats that jeopardize wildlife and human health.
Apoyo cuantitativo para los beneficios de la gestión proactiva del control de enfermedades silvestres Resumen Uno de los mayores retos en la actualidad es encontrar estrategias eficaces de mitigación de patógenos. En el contexto de la fauna silvestre, las enfermedades infecciosas emergentes han causado en varias ocasiones una morbilidad generalizada de los hospedadores y el declive de las poblaciones de numerosos taxones. En zonas aún no afectadas por un patógeno, un enfoque de gestión proactivo tiene el potencial de minimizar o prevenir la mortalidad de los hospederos. Sin embargo, en general se carece de información crítica sobre la dinámica de la enfermedad en el nuevo sistema huésped, las pruebas empíricas sobre la eficacia de las intervenciones de gestión son limitadas y faltan modelos predictivos validados. Por lo tanto, no existe un apoyo cuantitativo para identificar intervenciones de gestión eficaces y a menudo se pierde la oportunidad de una gestión proactiva. Consideramos la posible invasión del hongo quitridio Batrachochytrium salamandrivorans (Bsal), cuya aparición prevista en América del Norte supone una grave amenaza para cientos de especies de salamandras en este punto caliente de la biodiversidad mundial de salamandras. Desarrollamos y parametrizamos un modelo dinámico de ocupación multiestado para predecir la presencia de hospederos y patógenos, tras la aparición esperada del patógeno, y evaluamos la respuesta de las poblaciones de salamandras a diferentes escenarios de gestión. Nuestro modelo predijo que no tomar ninguna medida sería catastrófico para las poblaciones de salamandras. También predijo que la acción proactiva maximizaría los resultados de ocupación de hospederos en relación con la gestión reactiva de esperar y ver, proporcionando así un apoyo cuantitativo a las oportunidades de gestión proactiva. La erradicación de Bsal fue improbable bajo todas las opciones de gestión evaluadas. Contrariamente a nuestras expectativas, incluso la detección temprana del patógeno tuvo poco efecto sobre los resultados de ocupación de Bsal o del hospedador. Nuestros resultados apoyan cuantitativamente a la gestión proactiva como la estrategia óptima para promover la persistencia de poblaciones de salamandras amenazadas por la enfermedad. Nuestro enfoque llena un vacío crítico al definir un marco para evaluar las opciones de gestión antes de la invasión de patógenos y, por lo tanto, puede servir como plantilla para hacer frente a nuevas amenazas de enfermedades que ponen en peligro la vida silvestre y la salud humana.
ABSTRACT
The joint influence of abiotic and biotic factors is important for understanding the transmission of generalist pathogens. Abiotic factors such as temperature can directly influence pathogen persistence in the environment and will also affect biotic factors, such as host community composition and abundance. At intermediate spatial scales, the effects of temperature, community composition, and host abundance are expected to contribute to generalist pathogen transmission. We use a simple transmission model to explain and predict how host community composition, host abundance, and environmental pathogen persistence times can independently and jointly influence transmission. Our transmission model clarifies how abiotic and biotic factors can synergistically support the transmission of a pathogen. The empirical data show that high community competence, high abundance, and low temperatures correlate with high levels of transmission of ranavirus in larval amphibian communities. Discrete wetlands inhabited by larval amphibians in the presence of ranavirus provide a compelling case study comprising distinct host communities at a spatial scale anticipated to demonstrate abiotic and biotic influence on transmission. We use these host communities to observe phenomena demonstrated in our theoretical model. These findings emphasize the importance of considering both abiotic and biotic factors, and concomitant direct and indirect mechanisms, in the study of pathogen transmission and should extend to other generalist pathogens with the capacity for environmental transmission.
ABSTRACT
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.
ABSTRACT
Climate change is one of the major drivers of biodiversity loss. Among vertebrates, amphibians are one of the more sensitive groups to climate change due to their unique ecology, habitat requirements, narrow thermal tolerance and relatively limited dispersal abilities. We projected the influence of climate change on an endemic toad, Malabar Tree Toad (Pedostibes tuberculosus; hereafter MTT) from the Western Ghats biodiversity hotspot, India, for two different shared socio-economic pathways (SSP) using multiple modeling approaches for current and future (2061-2080) scenarios. The data used predominantly comes from a citizen science program, 'Mapping Malabar Tree Toad' which is a part of the Frog Watch citizen science program, India Biodiversity Portal. We also evaluated the availability of suitable habitats for the MTT in Protected Areas (PAs) under the current and future scenarios. Our results show that annual precipitation was the most important bioclimatic variable influencing the distribution of MTT. We used MaxEnt (MEM) and Ensemble (ESM) modeling algorithms. The predicted distribution of MTT with selected environmental layers using MEM was 4556.95 km2 while using ESM was 18,563.76 km2. Overlaying PA boundaries on predicted distribution showed 37 PAs with 32.7% (1491.37 km2) and 44 PAs with 21.9% (4066.25 km2) coverage for MEM and ESM respectively. Among eight future climate scenarios, scenarios with high emissions showed a decreased distribution range from 33.5 to 68.7% of predicted distribution in PAs, while scenarios with low emissions showed an increased distribution range from 1.9 to 111.3% in PAs. PAs from the Central Western Ghats lose most suitable areas with a shift of suitable habitats towards the Southern Western Ghats. This suggests that MTT distribution may be restricted in the future and existing PAs may not be sufficient to conserve their habitats. Restricted and discontinuous distribution along with climate change can limit the dispersal and persistence of MTT populations, thus enhanced surveys of MTT habitats within and outside the PAs of the Western Ghats are an important step in safeguarding the persistence of MTT populations. Overall, our results demonstrate the use of citizen science data and its potential in modeling and understanding the geographic distribution and the calling phenology of an elusive, arboreal, and endemic amphibian species.
Subject(s)
Biodiversity , Bufonidae , Citizen Science , Climate Change , Ecosystem , Animals , India , Bufonidae/physiology , Conservation of Natural ResourcesABSTRACT
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.
Subject(s)
Amphibians , Animals , Amphibians/immunology , Allergy and Immunology , Immune System/immunology , Xenopus laevis/immunologyABSTRACT
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.
Subject(s)
Amphibians , Biodiversity , Conservation of Natural Resources , Ecosystem , Animals , Phylogeny , Biological EvolutionABSTRACT
In recent years, the challenge of preserving amphibian biodiversity has increasingly been addressed through technologies for the short-term storage of unfertilized spawn at low positive temperatures. Previously the possibility of using a 6.5 atm gaseous mixture of carbon monoxide and oxygen for prolonged hypothermic preservation of unfertilized oocytes for more than 4 days was shown. This study aimed to investigate the viability of oocytes R. temporaria preserved under conditions of hypothermia at 2.5, 3 and 6.5 excess atm pressure in the various gas mixture compositions (CO, N2O, O2) and pure oxygen. The use of pressure up to 3 excess atmospheres was significantly beneficial compared to 6.5 atm at the 7 days storage period. The results indicate that oxygen pressure is a critical factor in maintaining oocyte viability. Admixing CO or N2O to oxygen reduced variability in the results but did not significantly affect the measured indicators (fertilization, hatching) in the experimental groups. The composition CO + O2 (0.5/3.5 ratio, 3 excess atm) reliably extended the shelf life of viable oocytes, indistinguishable from native controls by fertilization and hatching rates, to 4 days. After 7 days, oocytes exhibited fertilization and hatching rates that were 79 % and 48 % compared to native control. Reducing the pressure of the preserving gas mixture to 3 atm, as utilized in this study, simplifies the practical implementation of gas preservation technology for maintaining endangered amphibian species during breeding in laboratory conditions.
Subject(s)
Carbon Monoxide , Cryopreservation , Nitrous Oxide , Oocytes , Oxygen , Rana temporaria , Animals , Oocytes/drug effects , Oocytes/cytology , Oxygen/metabolism , Cryopreservation/methods , Cryopreservation/veterinary , Carbon Monoxide/pharmacology , Female , Cell Survival/drug effects , PressureABSTRACT
Endochondral ossification plays a crucial role in the limb development of amphibians. This study explored the ossification sequence in the hindlimb of Rana zhenhaiensis tadpoles and the correlation between thyroid hormones (THs) and endochondral ossification via histomorphology and transcriptional analyses. Our results suggest that ossification of the femur and tibiofibula was initiated during the period of high THs activity (metamorphosis climax). In addition, the results of differentially expressed gene analyses in the hindlimb and tail showed that systemic factors, transcription factors, and locally secreted factors interacted with each other during the metamorphosis climax to regulate the occurrence of endochondral ossification. These results will enrich the morphological data of anurans and provide scientific reference for the evolutionary history of vertebrates.
ABSTRACT
In a global context of invasive alien species (IAS), native predators are often eradicated by functionally different IAS, which may induce complex cascading consequences on ecosystem functioning because of the key role predators play in structuring communities and stabilizing food webs. In permanent ponds, the most abundant freshwater systems on Earth, global human-mediated introductions of alien omnivores such as the pet trade goldfish are driving broad-scale patterns of native predators' exclusion, but cascading consequences on food web structure and functioning are critically understudied. We compared food webs of naturally fishless ponds versus ponds where dominant native predators (newts) had been extirpated by invasive goldfish within the last decade. Integrating community-wide isotopic, taxonomic and functional traits approaches, our study reveals that pond food webs collapsed in both vertical and horizontal dimensions following goldfish introduction and the associated exclusion of native predators. Consumer taxonomic diversity was drastically reduced, essentially deprived of amphibians as well as predatory and mobile macroinvertebrates to the profit of burrowing, lower trophic level consumers (detritivores). Changes in community structure and function underlined a regime shift from a macrophyte-dominated system mainly characterized by benthic primary production (periphyton), to a macrophyte-depleted state of ponds hosting communities mainly associated with phytoplankton primary production and detritus accumulation, with higher tolerance to eutrophication and low dissolved oxygen concentration. Results underline major impacts of widely introduced omnivores such as the goldfish on the functioning of pond ecosystems with potentially dramatic consequences on the key ecosystem services they deliver, such as global biodiversity support or water quality improvement. They also shed light on the key role of submerged aquatic vegetation in supporting diverse communities and complex food webs in shallow lentic systems and call for urgent consideration of threats posed by IAS on ponds' ecosystems by managers and policymakers.
Subject(s)
Food Chain , Goldfish , Introduced Species , Ponds , Animals , Goldfish/physiology , BiodiversityABSTRACT
Natural history collections have long served as the foundation for understanding our planet's biodiversity, yet they remain a largely untapped resource for wildlife disease studies. Extended specimens include multiple data types and specimen preparations that capture the phenotype and genotype of an organism and its symbionts-but preserved tissues may not always be optimized for downstream detection of various pathogens. Frogs are infected by an array of pathogens including Batrachochytrium dendrobatidis (Bd), Ranavirus (Rv), and Amphibian Perkinsea (Pr), which provides the opportunity to study differences in detection dynamics across tissue types. We used quantitative PCR protocols to screen two tissue types commonly deposited in museum collections, toe clips and liver, from two closely related host species, Rana catesbeiana and Rana clamitans. We compared Bd, Rv, and Pr infection prevalence and intensity between species and tissue types and found no significant difference in prevalence between species, but Bd intensity was higher in R. clamitans than R. catesbeiana. Toe tissue exhibited significantly higher Bd infection loads and was more useful than liver for detecting Bd infections. In contrast, Rv was detected from more liver than toe tissues, but the difference was not statistically significant. Our results support the use of extended specimen collections in amphibian disease studies and demonstrate that broader tissue sampling at the time of specimen preparation can maximize their utility for downstream multipathogen detection.
ABSTRACT
The intensification of livestock farming can pose risks to the environment due to the increased use of veterinary products and the generation of waste in confined areas. The quality of water bodies near livestock establishments (Areco River (A) and Doblado stream (D), San Antonio de Areco, Buenos Aires, Argentina) was studied by physicochemical parameters, metals, pesticides, emerging contaminants, and lethal and sublethal toxicity (neurotoxicity and oxidative stress) in larvae of the native amphibian Rhinella arenarum. Six sites were selected: upstream (S1A and S1D), at the level (S2A and S2D), and downstream (S3A and S3D) from the establishments. A low concentration of dissolved oxygen was observed in Doblado stream (< 2.34 mg/L). Cu, Mn, V, and Zn exceeded the limits for the protection of aquatic life at various sites. Between 24 and 34 pesticides were detected in all sites, with 2,4-D, atrazine, and metolachlor being the most recurrent. In water and sediment, the concentrations of ivermectin (S2A, 1.32 µg/L and 58.18 µg/kg; S2D, 0.8 µg/L and 85.22 µg/kg) and oxytetracycline (S2A, < 1 mg/L and < 1 mg/kg; S2D, 11.8 mg/L and 39 mg/kg) were higher at sites near the establishments. All sites caused between 30 and 38.3% of lethality and produced neurotoxicity and alterations in the reduced glutathione content. Moreover, larvae exposed to samples from all sites incorporated ivermectin. These results demonstrate the degradation of the studied sites in relation to the agricultural activities of the area, highlighting the need to take measures to protect and preserve aquatic ecosystems.
Subject(s)
Agriculture , Ecotoxicology , Environmental Monitoring , Water Pollutants, Chemical , Water Quality , Animals , Water Pollutants, Chemical/analysis , Argentina , Cattle , Pesticides/toxicityABSTRACT
Ticks parasitize a wide variety of wild animals, including amphibians and reptiles. In addition to the possibility of microorganism transmission to these hosts, ticks can also cause severe bleeding, and high parasitism can lead to death. Therefore, knowing the diversity of ticks parasitizing amphibians and reptiles is important for conservation and preservation measures for these vertebrates. In the present study, we report parasitism by ticks in amphibians and reptiles from different Brazilian biomes (Amazon, Caatinga, Cerrado and Atlantic Forest). Ticks were collected from amphibians and reptiles deposited from the Herpetological Collection of the Federal University of Maranhão (UFMA), São Luís (Maranhão State), the State University Santa Cruz (UESC), Ilhéus (Bahia State), and the Federal University of São Francisco Valley (Univasf), Petrolina (Pernambuco State). Additionally, ticks were collected from amphibians and reptiles captured and road-killed in the Amazon biome, at Maranhão and Amapá States. Specimens of ticks were photographed under a Zeiss stereomicroscope (5.1 zoom). Map with the locations were made using the Qgis program. Overall, 1973 specimens of amphibians and reptiles were examined. A total of 927 ticks were collected: 98 larvae, 421 nymphs and 408 adults. Six species of ticks were identified: Amblyomma rotundatum and Amblyomma dissimile the most frequent, and Amblyomma cajennense sensu stricto, Amblyomma sculptum, Amblyomma nodosum and Amblyomma humerale, occasionally. Surprisingly, a total of twelve males of A. rotundatum were collected. Here we report new records of association between cold-blooded animals and ticks and reinforce the absence of A. dissimile in the Caatinga, Cerrado and Atlantic Forest biomes. Additionally, we report new records of A. rotundatum males on reptiles in the Amazon biome. This last record allows us to speculate about a possible association of A. rotundatum males with reptiles and the Amazon biome.
ABSTRACT
Amphibians represent a diverse group of tetrapods, marked by deep divergence times between their three systematic orders and families. Studying amphibian biology through the genomics lens increases our understanding of the features of this animal class and that of other terrestrial vertebrates. The need for amphibian genomics resources is more urgent than ever due to the increasing threats to this group. Amphibians are one of the most imperiled taxonomic groups, with approximately 41% of species threatened with extinction due to habitat loss, changes in land use patterns, disease, climate change, and their synergistic effects. Amphibian genomics resources have provided a better understanding of ontogenetic diversity, tissue regeneration, diverse life history and reproductive modes, antipredator strategies, and resilience and adaptive responses. They also serve as critical models for understanding widespread genomic characteristics, including evolutionary genome expansions and contractions given they have the largest range in genome sizes of any animal taxon and multiple mechanisms of genetic sex determination. Despite these features, genome sequencing of amphibians has significantly lagged behind that of other vertebrates, primarily due to the challenges of assembling their large, repeat-rich genomes and the relative lack of societal support. The advent of long-read sequencing technologies, along with computational techniques that enhance scaffolding capabilities and streamline computational workload is now enabling the ability to overcome some of these challenges. To promote and accelerate the production and use of amphibian genomics research through international coordination and collaboration, we launched the Amphibian Genomics Consortium (AGC) in early 2023. This burgeoning community already has more than 282 members from 41 countries (6 in Africa, 131 in the Americas, 27 in Asia, 29 in Australasia, and 89 in Europe). The AGC aims to leverage the diverse capabilities of its members to advance genomic resources for amphibians and bridge the implementation gap between biologists, bioinformaticians, and conservation practitioners. Here we evaluate the state of the field of amphibian genomics, highlight previous studies, present challenges to overcome, and outline how the AGC can enable amphibian genomics research to "leap" to the next level.
ABSTRACT
Assessing the extinction risk of species based on the International Union for Conservation of Nature (IUCN) Red List (RL) is key to guiding conservation policies and reducing biodiversity loss. This process is resource demanding, however, and requires continuous updating, which becomes increasingly difficult as new species are added to the RL. Automatic methods, such as comparative analyses used to predict species RL category, can be an efficient alternative to keep assessments up to date. Using amphibians as a study group, we predicted which species are more likely to change their RL category and thus should be prioritized for reassessment. We used species biological traits, environmental variables, and proxies of climate and land-use change as predictors of RL category. We produced an ensemble prediction of IUCN RL category for each species by combining 4 different model algorithms: cumulative link models, phylogenetic generalized least squares, random forests, and neural networks. By comparing RL categories with the ensemble prediction and accounting for uncertainty among model algorithms, we identified species that should be prioritized for future reassessment based on the mismatch between predicted and observed values. The most important predicting variables across models were species' range size and spatial configuration of the range, biological traits, climate change, and land-use change. We compared our proposed prioritization index and the predicted RL changes with independent IUCN RL reassessments and found high performance of both the prioritization and the predicted directionality of changes in RL categories. Ensemble modeling of RL category is a promising tool for prioritizing species for reassessment while accounting for models' uncertainty. This approach is broadly applicable to all taxa on the IUCN RL and to regional and national assessments and may improve allocation of the limited human and economic resources available to maintain an up-to-date IUCN RL.
Uso del análisis comparativo del riesgo de extinción para priorizar la reevaluación de los anfibios en la Lista Roja de la UICN Resumen El análisis del riesgo de extinción de una especie con base en la Lista Roja (LR) de la Unión Internacional para la Conservación de la Naturaleza (UICN) es clave para guiar las políticas de conservación y reducir la pérdida de la biodiversidad. Sin embargo, este proceso demanda recursos y requiere de actualizaciones continuas, lo que se complica conforme se añaden especies nuevas a la LR. Los métodos automáticos, como los análisis comparativos usados para predecir la categoría de la especie en la LR, pueden ser una alternativa eficiente para mantener actualizados los análisis. Usamos a los anfibios como grupo de estudio para predecir cuáles especies tienen mayor probabilidad de cambiar de categoría en la LR y que, por lo tanto, se debería priorizar su reevaluación. Usamos las características biológicas de la especie, las variables ambientales e indicadores climáticos y del cambio de uso de suelo como predictores de la categoría en la LR. Elaboramos una predicción de ensamble de la categoría en la LR de la UICN para cada especie mediante la combinación de cuatro algoritmos diferentes: modelos de vínculo acumulativo, menor número de cuadros filogenéticos generalizados, bosques aleatorios y redes neurales. Con la comparación entre las categorías de la LR y la predicción de ensamble y con considerar la incertidumbre entre los algoritmos identificamos especies que deberían ser prioridad para futuras reevaluaciones con base en el desfase entre los valores predichos y los observados. Las variables de predicción más importantes entre los modelos fueron el tamaño de la distribución de la especie y su configuración espacial, las características biológicas, el cambio climático y el cambio de uso de suelo. Comparamos nuestra propuesta de índice de priorización y los cambios predichos en la LR con las reevaluaciones independientes de la LR de la UICN y descubrimos un buen desempeño tanto para la priorización como para la direccionalidad predicha de los cambios en las categorías de la LR. El modelo de ensamble de la categoría de la LR esa una herramienta prometedora para priorizar la reevaluación de las especies a la vez que considera la incertidumbre del modelo. Esta estrategia puede generalizarse para aplicarse a todos los taxones de la LR de la UICN y a los análisis regionales y nacionales. También podría mejorar la asignación de los recursos humanos y económicos limitados disponibles para mantener actualizada la LR de la UICN.
ABSTRACT
Given the growing number of events involving exotic animals, it is crucial to prioritize the well-being of the animals involved. This study aims to evaluate the quality of animal presentation at a selected fair in Poland and assess the level of animal welfare evident in the exhibition boxes, contributing to the ongoing dialogue on this important issue. The evaluators used a five-point Likert scale and a Yes/No system to analyze the living conditions during the fair, including the size of containers, presence of substrate, and environmental enrichment. They also assessed the occurrence of visual abnormal postures and behaviors to gauge the overall level of welfare. To ensure the reliability and consistency of the data and minimize potential bias, each evaluator repeated the rating process three times, with a three-week interval between each session. An average value was then calculated for each aspect. A total of 818 animals were present at the fair, with 688 being reptiles (84.11%) and 130 being amphibians (15.89%). This study revealed that the provision of substrate scored higher for reptiles compared to amphibians, while the size of containers for amphibians received higher ratings than those for reptiles. Visual abnormalities in posture and behavior were more common in reptiles than in amphibians. Display containers for snakes received the lowest ratings and showed more visual abnormalities in posture and behavior, raising concerns about their welfare. Despite the presence of environmental enrichment, the overall level of animal welfare was assessed as being medium/low. Pearson's correlation coefficient indicated good reliability among the evaluators during the assessment process, with most assessments showing values > 0.8. Despite existing regulations for exhibitors, neglect remains prevalent. These findings highlight the potential negative impact of animal exposure at fairs on animal welfare. Display containers were often inadequately sized for the animals, particularly for snakes, chameleons, monitor lizards, and salamanders.
ABSTRACT
Reptiles and amphibians are largely present in many environments, including domestic areas when they are kept as pet animals. They often harbor zoonotic pathogens, which can pose a serious risk of infection for humans, mainly immunocompromised individuals, the elderly, children, and pregnant women. Several studies have been carried out to verify the role of cold-blooded animals in the epidemiology of some bacteria, mainly Salmonella, whereas scarce attention has been focused on these animals as a source of staphylococci. These bacteria are often antimicrobial-resistant and they act as opportunistic pathogens, which can cause relevant infections in humans and animals, both domestic and wild. Asymptomatic reptiles and amphibians often harbor staphylococcal strains, such as Staphylococcus aureus and coagulase-negative Staphylococcus spp.; however, these bacteria have been associated with clinical conditions that usually appear in animals under stress conditions. In all cases, greater attention should also be focused on staphylococci in cold-blooded animals due to their implications in human and veterinary medicine.