Search

Anthropogenic activity and urbanization subject the diversity and distribution of amphibians to constant change. This study aims to reveal the impact of increasing urbanization pressure on amphibian diversity, density, and distribution in Istanbul, a megacity. I researched amphibian species' presence and dispersal in and around the wetlands of Istanbul, spanning urban, semi-urban, and non-urban areas. I conducted surveys in 2016 and 2017 at 396 sites and found seven species (four families) of amphibians at 151 stations. Anurans occurred at 38.13% of sites, and newts at 8.6%. The alpha diversity of semi-urban regions was higher than in urban and non-urban areas of Istanbul. Nonmetric multidimensional scaling (NMDS) analysis of relative abundances of amphibian species at the three site types showed significant differences. Compared to the distribution of each species reported in the literature, I found that distributions have spread to the west, east, and north of the province. Several species occurred in semi-urban wetlands due to the pressure of urbanization, which causes extirpations or declines to low abundance, making their detection unlikely in urban areas. [ABSTRACT FROM AUTHOR]

Traditional methods of phylogenetic reconstruction and species delimitation may be impeded by frequent hybridization among lineages. In this study, we conducted phylogenetic and clustering analyses of ddRAD genomic data on the entire genus Salamandra, which includes six species and over 25 subspecies of terrestrial salamanders. We expanded previous datasets to include missing subspecies and incorporated new samples, with an emphasis on secondary contact zones. Results obtained from a full dataset of 392 individuals (356,874 bp; 24,192 SNPs) were compared with those obtained after excluding substantially admixed individuals (n = 95; 835,467 bp; 51,557 SNPs) to explore the consequences of introgression on phylogenetic inference and taxonomic arrangement of subspecies. We found conflicting phylogenetic placements for taxa represented by many admixed individuals (identified by clustering ancestries). In contrast, a time-calibrated tree constructed without hybrids largely agrees with previous phylogenetic hypotheses. Within S. atra, we found paraphyly of S. atra atra, suggesting an additional candidate subspecies. Within S. infraimmaculata, two lineages are assignable to known subspecies and we additionally identified a third, deeply diverged lineage sampled near the Turkish/Syrian border. In S. algira, we found limited admixture between the subspecies S. a. tingitana and S. a. splendens despite their geographic proximity. Finally, within S. salamandra, we detected significant levels of hybridization between subspecies, which blurred their phylogenetic relationships, although the removal of admixed samples in subset analyses clarified the situation in most cases. Monophyly was recovered for subspecies that were previously found paraphyletic, including S. s. salamandra, S. s. gallaica, and S. s. fastuosa. Salamandra s. "alfredschmidti" was confirmed to be a junior synonym of S. s. bernardezi. Previously disputed subspecies, like S. s. "molleri" and S. s. "hispanica", correspond to separated lineages but are affected by admixture with other lineages. Further newly identified candidate subspecies in S. salamandra included a southern lineage within S. s. wer-neri and a western lineage within S. s. bernardezi. Finally, we re-evaluate the status of recognized subspecies in Salamandra, based on evidence from multiple delimitation criteria. Given that the evolutionary history could not be resolved for all subspecies, we highlight taxa within Salamandra that warrant further molecular examination and taxonomic revision, notably within the S. s. gallaica/"molleri"/bejarae complex. This study illustrates the impact of hybridization in phylogenetic analyses and its downstream effects in the identification of conservation units and their naming in the Linnean classification. [ABSTRACT FROM AUTHOR]

We analyzed data from 3,546 occurrence records of Fire Salamanders (Salamandra salamandra) from the territory of the Czech Republic where it has a heterogeneous distribution pattern. Its occurrence in terrestrial habitats adjacent to breeding streams is characterized by a mean distance of 103 m, maximum 1,321 m, from the nearest stream. Based on a logistic GLM (generalized linear model) analysis we determined the Fire Salamanders' climatic and habitat associations at landscape scale in the Czech Republic. The main limiting factors for its dispersal include the proximity of small shallow streams in rolling landscapes, the pH of these streams, the presence of broad-leaf or mixed forests, humidity, solar irradiation, and severity of winters. While the absence of suitable breeding habitats is the main limiting factor for their occurrence in more expansive lowlands, factors such as lower temperatures, lower humidity, and the absence of broad-leaf and mixed forests begin to play a role with increasing altitude. Unlike cold temperatures, low amounts of precipitation and higher temperatures do not act as limiters in the Czech Republic. Fire Salamanders respond to the colder climate of higher altitudes with intensified summer activity and the purely bimodal nature of their activity (with spring and autumn peaks) tends to fade at higher altitudes. [ABSTRACT FROM AUTHOR]

Aim: Intraspecific genetic variation is key for adaptation and survival in changing environments and is known to be influenced by many factors, including population size, dispersal and life‐history traits. We investigated genetic variation within Neotropical amphibian species to provide insights into how natural history traits, phylogenetic relatedness, climatic and geographic characteristics can explain intraspecific genetic diversity. Location: Neotropics. Taxon: Amphibians. Methods: We assembled data sets using open‐access databases for natural history traits, genetic sequences, phylogenetic trees, climatic and geographic data. For each species, we calculated overall nucleotide diversity (π) and tested for isolation by distance (IBD) and isolation by environment (IBE). We then identified predictors of π, IBD and IBE using random forest (RF) regression or RF classification. We also fitted phylogenetic generalized linear mixed models (PGLMMs) to predict π, IBD and IBE. Results: We compiled 4052 mitochondrial DNA sequences from 256 amphibian species (230 frogs and 26 salamanders), georeferencing 2477 sequences from 176 species that were not linked to occurrence data. RF regressions and PGLMMs were congruent in identifying range size and precipitation (σ) as the most important predictors of π, influencing it positively. RF classification and PGLMMs identified minimum elevation as an important predictor of IBD; most species without IBD tended to occur at higher elevations. Maximum latitude and precipitation (σ) were the best predictors of IBE, and most species without IBE occur at lower latitudes and in areas with more variable precipitation. Main Conclusions: This study identified predictors of genetic variation in Neotropical amphibians using both machine learning and phylogenetic methods. This approach was valuable to determine which predictors were congruent between methods. We found that species with small ranges or living in zones with less variable precipitation tended to have low genetic diversity. We also showed that Western Mesoamerica, Andes and Atlantic Forest biogeographic units harbour high diversity across many species that should be prioritized for protection. These results could play a key role in the development of conservation strategies for Neotropical amphibians. [ABSTRACT FROM AUTHOR]

The fully aquatic Japanese giant salamander (Andrias japonicus) is a member of the Cryptobranchidae, and is currently distributed in western Japan, with other members of this group restricted to China and North America. Their feeding behaviour is characterized by a form of suction feeding that includes asymmetric movements of the jaw and hyobranchial apparatus. Previous studies on the North American species, Cryptobranchus alleganiensis, have suggested that this specialized jaw movement is produced by a flexible quadrate‐articular joint combined with a loosely connected lower jaw symphysis including two small fibrocartilaginous pads. However, little is known about this feeding behaviour in the Asian species, nor have the three‐dimensional asymmetric jaw movements been fully investigated in any member of Cryptobranchidae. In this study, we explore the asymmetric jaw movements in A. japonicus using three methods: (1) dissection of musculoskeletal structures; (2) filming of feeding behaviour to understand in which situations asymmetric feeding is used; (3) analysis of 3D movement of jaws and skull. In the third component, fresh (from frozen) specimens of A. japonicus were manipulated to replicate asymmetric and symmetric jaw movements, with the specimens CT scanned after each step to obtain the 3D morphology of the jaws at different positions. These positions were combined and their Euler angles from resting (closed) jaw position were calculated for asymmetric or symmetric jaw positions. Our filming revealed that asymmetric jaw movements are linked to the position of the prey in relation to the snout, with the jaw closest to the prey opening asymmetrically. Moreover, this action allows the salamander to simultaneously grasp prey in one side of the mouth while ejecting water on the other side, if the first suction attempt fails. The asymmetric jaw movements are performed mainly by rotation of the mandible about its long axis, with very limited lateral jaw movements. During asymmetric and symmetric jaw movements, the posterior ends of the maxilla and quadrate move slightly. The asymmetric jaw movements are permitted by a mobile quadrate‐articular joint formed by wide, round cartilages, and by two small fibrocartilage pads within the jaw symphysis that act as cushions during jaw rotation. Some of these soft tissue structures leave traces on the jaws and skull, allowing feeding mode to be reconstructed in fossil taxa. Understanding cryptobranchid asymmetric jaw movement thus requires a comprehensive assessment of not only the symphysial morphology but also that of other cranial and hyobranchial elements. [ABSTRACT FROM AUTHOR]

Tonic immobility is an antipredator defence in which the prey animal remains motionless after physical contact with the predator, pretending to be dead. This behaviour has been observed among a variety of taxa but has received only little attention in amphibian larvae. During our field studies with fire salamander larvae, we observed that larvae from different habitats display tonic immobility after handling. In our study site, we find larvae in pond and stream habitats, that differ in several aspects such as their stress response and their risk‐taking behaviour, likely caused by the very different habitat conditions. We measured the time that the tonic immobility behaviour was displayed but found no difference between larvae from the two habitat types. Likewise, we also found no correlation between the size of the larvae and the duration of displaying the behaviour. In conclusion, we found that fire salamander larvae show tonic immobility, but found no evidence that the different habitat conditions influence the tonic immobility behaviour. [ABSTRACT FROM AUTHOR]

Simple Summary: Amphibians are classified into three orders with different morphological characteristics: Anura, Apoda, and Caudata. In this article, the importance of skin for amphibians is discussed as it represents a physical, chemical, immunological, and microbiological barrier to pathogen insult is discussed. Langerhans cells (LCs) are antigen-presenting cells constituting an important component of the immune system in the skin. This study aims to characterize Langerhans cells in the skin of Lithobates catesbeianus (Shaw, 1802), Amphiuma means (Garden, 1821), and Typhlonectes natans (Fischer, 1880) with several antibodies previously used to mark the same cells in other vertebrates. The results showed that the distribution of LCs is very similar in the three amphibian species examined, despite their different habitats. In conclusion, the amphibian dendritic cells are morphologically and immunohistochemically homologous to the LCs of all vertebrates so they can be considered as starting points to better understand the phylogeny of the vertebrate immune system. The amphibian taxon includes three orders that present different morphological characteristics: Anura, Caudata, and Apoda. Their skin has a crucial role: it acts as an immune organ constituting a physical, chemical, immunological, and microbiological barrier to pathogen insult and conducts essential physiological processes. Amphibians have developed specialized features to protect the vulnerable skin barrier, including a glandular network beneath the skin surface that can produce antimicrobial and toxic substances, thus contributing to the defense against pathogens and predators. This study aims to characterize Langerhans cells in the skin of Lithobates catesbeianus (order: Anura; Shaw, 1802), Amphiuma means (order: Caudata; Garden, 1821), and Typhlonectes natans (order: Apoda; Fischer, 1880) with the following antibodies: Langerin/CD207 (c-type lectin), Major Histocompatibility Complex (MHC)II, and Toll-like receptor (TLR)2 (expressed by different types of DCs). Our results showed Langerhans cells positive for Langerin CD/207 in the epidermis of the three species; moreover, some antigen-presenting cells (APCs) in the connective tissue expressed TLR2 and MHCII. The distribution of the Langerhans cells is very similar in the three amphibians examined, despite their different habitats. A greater knowledge of the amphibian immune system could be useful to better understand the phylogeny of vertebrates and to safeguard amphibians from population declines. Furthermore, the similarities between amphibians' and human skin concerning immunological features may be useful in both biology and translational medicine. [ABSTRACT FROM AUTHOR]

Objective: The present study focused on the effect of different lipid levels on growth (weight and length) and survival in juvenile Ambystoma mexicanum. Design/methodology/approach: Four diets with the same 45% protein level and different lipid levels: 6, 8, 10 and 12% were tested for a period of 81 days. For the preparation of the diets, two key ingredients were used, such as fishmeal and fish oil, these as protein base and lipid source. The experiment consisted of placing six organisms per experimental unit in tubs with 40 L of water for a period of 81 days; period during which four biometrics were performed, the organisms were fed every 48 hours to the weight of their biomass. The digestibility of the diets, initial and final height, initial and final weight, weight gained, weight gained per day, specific growth rate, survival, Fulton index and protein efficiency rate were recorded. Results: At the end of the experiment, significant differences (p>0.05) were observed in the growth and survival of the axolotls in the diets of 8, 10 and 12% lipids. Limitations on study/implications: A wider range of lipid levels could not be tested, due to the number of individuals available for the experiment. Findings/conclusions: According to the data obtained in this study, it is recommended to include a level of 45% protein and 8% lipids in the diets of juvenile Ambystoma mexicanum, for their better development and nutrition. [ABSTRACT FROM AUTHOR]

The identification of conservation priority areas for amphibians in Iran remains unexplored. Although protected areas play a vital role in biodiversity conservation, 40 percent of amphibians are at risk of extinction. The present study aimed to identify the priority areas for amphibian conservation and assess the effectiveness of the current protected conservation areas. 2192 species occurrence points for 23 amphibians, including 16 species of Anura and 7 species of Caudata, were curated. These occurrence points in addition to bioclimatic, anthropogenic, and geographical variables were used to model the species distribution. Then, the richness and rarity maps of amphibians were determined and hotspots identified based on the top 10 % area of the country with the highest richness and rarity values. Finally, Iran's protected areas were overlaid to evaluate the current coverage of hotspots and identify future conservation priorities. Although approximately 12 % of Iran is currently protected, the present study findings indicate that the current network of protected areas is ineffective for amphibian conservation; over 90 % of hotspots for amphibians lie outside the current national protected area network. The most important hotspots are located in the Caspian Hyrcanian Mixed Forest, the western margin of the North Zagros, and the Central Zagros Mountains Forest-Steppe ecoregions of the country. Among different types of protected areas that overlap with amphibian hotspots, protected areas and wildlife refuges respectively ranked the highest in quantity and size, while national parks ranked the lowest. In the current study, a baseline of top candidate areas for expanding protected areas where habitats can be managed to protect amphibians in Iran was provided. To further improve protected areas' coverage, priority conservation areas in the Zagros Mountains Forest-Steppe hotspots were recommended.

Climate change can affect species' geographical range in several ways, leading to species' geographical range expansion and contraction. Amphibians are the most threatened vertebrate class, and deterioration is due, in part, to the loss of suitable habitat. This taxonomic group is especially sensitive because of their biphasic life cycles (aquatic and terrestrial) and microhabitat requirements. Herein, we propose a combined approach, which uses biological and life history information to understand species' sensitivity to climate change. The goals of our study were to (1) identify the contribution of environmental variables to the broad-scale distribution of amphibians in drylands of the southwestern United States and Mexico, (2) describe how the habitat suitability of amphibians can potentially respond to a range of climate change scenarios across drylands, and (3) identify amphibian traits related to increased vulnerability and adaptation to the specific pressures and mechanisms of climate change projected for the dryland areas. Results show that climate strongly influences the geographic distribution of amphibian diversity in drylands and that most amphibians are expected to lose habitat in the upcoming decades. This study also shows that areas with the greatest loss of high habitat suitability are related to temperature increases and precipitation reductions. Our results build a framework that will significantly improve the current state of knowledge on the drylands' biogeography while providing comprehensive information and analyses for decision-makers to conserve and protect endangered and threatened amphibian species and their habitats.

Abstract Tonic immobility is an antipredator defence in which the prey animal remains motionless after physical contact with the predator, pretending to be dead. This behaviour has been observed among a variety of taxa but has received only little attention in amphibian larvae. During our field studies with fire salamander larvae, we observed that larvae from different habitats display tonic immobility after handling. In our study site, we find larvae in pond and stream habitats, that differ in several aspects such as their stress response and their risk‐taking behaviour, likely caused by the very different habitat conditions. We measured the time that the tonic immobility behaviour was displayed but found no difference between larvae from the two habitat types. Likewise, we also found no correlation between the size of the larvae and the duration of displaying the behaviour. In conclusion, we found that fire salamander larvae show tonic immobility, but found no evidence that the different habitat conditions influence the tonic immobility behaviour.

Crown salamanders first appeared in the Middle Jurassic (Bathonian) and remains of these oldest representatives of the group have been found in various vertebrate localities in China, Western Siberia, and Western Europe. Here, we report the discovery of an indeterminate crown salamander in the Middle Jurassic (Bathonian) Peski locality of Moskvoretskaya Formation of the Moscow Region, Russia. This find (a fragmentary trunk vertebra) represents (1) new occurrence of the oldest crown salamanders; and (2) the first fossil record of crown salamanders in the Middle Jurassic of Eastern Europe. The trunk vertebra from the Peski locality resembles those of the modern crown salamanders of the Salamandroidea clade in the presence of spinal nerve foramina and bicapitate transverse processes. If our assignment of the Peski salamander to Salamandroidea is correct, then it is the oldest salamandroid in the fossil record. [ABSTRACT FROM AUTHOR]

Studies on the skin microbiota of amphibians in different disturbed habitats can clarify the relationship between the skin microbiota composition and environmental factors and have practical implications for the conservation of endangered species. In this study, 16S rRNA high-throughput sequencing was used to profile the skin microbiota of Maoershan hynobiids (Hynobius maoershanensis). Our results illustrate that the alpha diversity of the skin microbiota significantly differed among individuals in higher anthropogenic disturbance-degree (HADD) habitats and lower anthropogenic disturbance-degree (LADD) habitats. The diversity of the skin microbiota in forelimb bud-stage tadpoles from HADD habitats was higher than that in their counterparts from LADD habitats. The richness of the skin microbiota in hindlimb bud-stage tadpoles was greater in HADD habitats than in LADD habitats. However, the alpha diversity of the adult skin microbiota did not differ significantly between the two habitats. Furthermore, stepwise regression analysis indicated that the skin microbiota diversity and relative abundance of dominant bacteria decreased with increasing air temperature, water temperature, and pH; conversely, skin microbiota richness increased with increasing humidity. In addition, the relative abundance of dominant bacteria was influenced by anthropogenic disturbance. We conclude that the skin microbiota of Maoershan hynobiids is affected by ecological factors and anthropogenic disturbance, highlighting the importance of the skin microbiota in response to habitat alteration. [ABSTRACT FROM AUTHOR]

Skin fungi are among the most dangerous drivers of global amphibian declines, and few mitigation strategies are known. For Batrachochytrium salamandrivorans (Chytridiomycota), available treatments rely on temperature, partially combined with antifungal drugs. We report the clearance of B. salamandrivorans in 2 urodelan species using a solely drug-based approach.

The amphibian taxon includes three orders that present different morphological characteristics: Anura, Caudata, and Apoda. Their skin has a crucial role: it acts as an immune organ constituting a physical, chemical, immunological, and microbiological barrier to pathogen insult and conducts essential physiological processes. Amphibians have developed specialized features to protect the vulnerable skin barrier, including a glandular network beneath the skin surface that can produce antimicrobial and toxic substances, thus contributing to the defense against pathogens and predators. This study aims to characterize Langerhans cells in the skin of Lithobates catesbeianus (order: Anura; Shaw, 1802), Amphiuma means (order: Caudata; Garden, 1821), and Typhlonectes natans (order: Apoda; Fischer, 1880) with the following antibodies: Langerin/CD207 (c-type lectin), Major Histocompatibility Complex (MHC)II, and Toll-like receptor (TLR)2 (expressed by different types of DCs). Our results showed Langerhans cells positive for Langerin CD/207 in the epidermis of the three species; moreover, some antigen-presenting cells (APCs) in the connective tissue expressed TLR2 and MHCII. The distribution of the Langerhans cells is very similar in the three amphibians examined, despite their different habitats. A greater knowledge of the amphibian immune system could be useful to better understand the phylogeny of vertebrates and to safeguard amphibians from population declines. Furthermore, the similarities between amphibians’ and human skin concerning immunological features may be useful in both biology and translational medicine.

Anurans, along with urodeles and caecilians are the extant representatives of the clade Lissamphibia. Nowadays, lissamphibians are widely distributed in all continents, except Antarctica, but are particularly diversified in South America, where almost 3,000 species are found. This huge biodiversity is directly related to the complex geologic history of South America, which includes key events like the Gondwanan breakup, its isolation during parts of Mesozoic and Cenozoic, the Andean uplift, and the formation of the Panamá isthmus. Here, we present the most comprehensive bibliographic review of fossil lissamphibians from South America to date, covering unpublished (e.g. theses and dissertations) and published data (i.e. peer-reviewed scientific papers, book chapters, monographs, and conferences abstracts). We use a mixed approach, both qualitative (with brief comments on each taxon and specimen) and quantitative (including scientometric parameters). Compared to the latest published reviews with similar scope, our results indicate that approximately 85.4% of the records correspond to specimens new to science or older ones that have been revisited. These materials come from 164 different fossil-bearing localities, spread over eight of the twelve South American countries, and range from the Early Jurassic to the Quaternary. In total, we compile 273 records, mostly anurans (~97.6%), followed by indeterminate caecilians (~1.4%) and urodeles (~1%). Additionally, we discuss issues directly related to those fossil occurrences, such as their temporal and geographic range, as well as the presence of putative biological and taphonomic biases. Finally, we also provide calibration constraints for several anuran taxa. [ABSTRACT FROM AUTHOR]

For at least two decades, European amphibians have been affected by the ‘salamander plague’, an emerging infectious disease caused by the invasive chytrid skin fungus Batrachochytrium salamandrivorans (Bsal) that originated from Asia. Resulting dramatic declines are well known from the European Fire Salamander, while the impact of Bsal on other European amphibians in the wild is less clear. We here focus on the Northern Crested Newt (Triturus cristatus) in Germany. This species is susceptible to Bsal and strictly protected under Annex II of the EC Habitats Directive. While T. cristatus is declining in the Bsal-hotspot Germany, it remains to be answered if the salamander plague is one of the leading drivers. By asking five key questions we review the available information with the goal of providing a baseline for further research. In two investigated newt communities, Bsal-prevalence was found to be considerably high, with 75–89% of newts being infected, reaching the highest peaks in spring. Later in the year, some T. cristatus were apparently able to clear their Bsal infection, even when individual infection load was previously high. Although we observed mortality of infected specimens and declines in populations with Bsal, declines are also seen outside known Bsal regions. Thus, it appears that the Bsal epidemic is not exclusively responsible for the species’ current status. With this, Bsal poses a yet poorly-understood threat to Northern Crested Newt survival, making further research on pathogen/host interactions and long-term survival indispensable to fulfil our legal responsibility of conserving this emblematic species. [ABSTRACT FROM AUTHOR]

Population monitoring is a crucial method for conservation projects, especially for the highly endangered clade of amphibians which is threatened by habitat loss and emerging infectious diseases such as the chytrid fungus Batrachochytrium salamandrivorans (Bsal). Bsal has led to massive population declines of European fire salamanders in Belgium, the Netherlands and parts of Germany and population trends are decreasing. Thus, regular population monitoring is essential to keep track of population dynamics and detect potential Bsal outbreaks, especially since valid population estimates for many species and/or populations are scarce. In recent years, photographic mark-recapture studies have gained importance enabling researchers to keep track of individuals without the use of harmful marking techniques that might influence behaviour or survival. We monitored a European fire salamander population over four years in the Kottenforst forest, Germany, by combining a mark-recapture approach with a new photo-recognition software, the Amphibian and Reptile Wildbook. We investigated potential differences of two ecotypes, i.e., larval populations bred in ponds and streams. Furthermore, we compared the observed number of larvae and the estimated population sizes between two consecutive years. There was a year effect on the observed number of larvae, the percentage of injured larva and estimated population size. The habitat type affected apparent survival rates. There was also a habitat effect on the percentage of injured larvae, but this was only existent in some years. The mean larval size, water temperature and the superpopulation size were not affected by any of the aforementioned factors. Although the population was free from Bsal, the high variation in the population estimates emphasize the need for a regular and standardised monitoring to assess the current population status and detect early population declines that might otherwise remain overlooked. [ABSTRACT FROM AUTHOR]

Background and Research Aims: Globally, Colombia is the country with the largest extent of Páramos (delimited in 36 complexes) and with the greatest number of amphibian species in this ecosystem. This work consolidated scientific literature on the amphibians of the Colombian Páramos to characterize temporal, taxonomic, thematic, and geographic patterns, which allow us to identify information gaps that must be fulfilled to achieve effective species conservation. Methods: We conducted a systematic literature survey with seven different search strategies and generated a database. We read each document's Abstract, Methods, Study Area, Results, and supplementary material, following the PRISMA (Preferred Reporting Items for Systematic reviews and Meta-Analyses) protocol. Results: We found 405 documents published between 1863 and 2021. The composition and richness of 142 amphibian species (95 endemics to Colombia), presented significant differences in Páramo complexes and between sectors. Since 2000, the diversity of research topics has increased with a high proportion of studies on Natural History, Systematics and Taxonomy, and Conservation, distributed between 19 and 22 of the departments with Páramos in their jurisdiction. However, much of this knowledge concentrates in less than 20% of total species in just 6% of Páramos complexes. Conclusion: We found critical shortfalls in taxonomy, spatial information, and conservation actions on Páramos amphibians. We need to increase studies that include field data in more geographic areas and research topics, such as Population and Community ecology, Natural history (from a quantitative approach), Infectious disease, and Ecophysiology. Implications for Conservation: The scientific information gaps represent a challenge in generating effective strategies to conserve Páramo amphibians, considering the high degree of endemism and threats to these species. More than 80% of the Páramo amphibian species only have the information of their descriptions and little is known about their ecological requirements, population size, or data related to specific threats. [ABSTRACT FROM AUTHOR]

The great crested newt Triturus cristatus is a widely distributed species across Europe and its southernmost range reaches northwestern Bulgaria. Triturus cristatus is comparatively well-studied in general, however, data about its distribution and habitat preferences in Bulgaria are very scarce. This study presents the results of an extensive field research (carried out in 2021) and a review of all available previous data for the species in Bulgaria. All known localities of T. cristatus in the country fall into a total of 22 UTM-squares (10 x 10 km), for 10 of which the species is newly discovered. The distribution of T. cristatus in Bulgaria is wider than previously thought and covers almost the entire north-western part of the country. The altitudinal range is relatively wide (40–1380 m a.s.l.) but most of the localities are situated below 500 m. In terms of habitat preferences, our results demonstrate that T. cristatus prefers water bodies of small area (below 1000 m² ), shallow depth (0.5–1 m), muddy bottom, without reed/bulrush and without fish. Regarding the terrestrial phase, it can only be stated that in the vicinity (400 m radius) of the water bodies in which the species was found, the predominant type of land cover is “Agricultural areas”, followed by “Forest and semi natural areas”, but the preferences of T. cristatus to specific terrestrial habitats in the Bulgarian part of distribution range remain unknown. [ABSTRACT FROM AUTHOR]

In Colombia, amphibians are a vertebrate group with a high taxonomic richness, and an elevated representativity of species with restricted distributions. In recent years, regional collections have assisted to fill information gaps on the biogeography, intra- and interspecific variation, and systematics of the amphibians of the country. In this work we present the information of 1533 records deposited in the Amphibian Collection of the Museo de Historia Natural of the Universidad de Caldas, represented by 143 species, belonging to 49 genera and 19 families. Most of the records (n = 1194) come from the Department of Caldas, but there are records for 16 additional departments. The most representative order is Anura (n = 1487 records) followed by Caudata (n = 27 records), and Gymnophiona (n = 19 records). The collection houses 152 specimens that have been referenced in 13 national and foreign publications. [ABSTRACT FROM AUTHOR]

Although the distribution patterns of major amphibian lineages are mainly explained by a Pangean origin with subsequent vicariant diversification, dispersal events have exerted a strong influence on present-day distributions. Long-distance dispersal (LDD) involves movements outside the standard geographic limits and outside the genetic neighbourhood area of individuals. Although considered ‘rare’, LDD is disproportionately important to amphibian populations, species and communities. To understand the role of LDD in shaping current biogeographic patterns in these tetrapods, we reviewed the cases reported in the literature. A systematic bibliographic search was performed to obtain information on how many studies have dealt with LDD in amphibians, which methods they used, which taxa and distances were involved, and when/where events had apparently occurred. In 41 studies, we recovered at least 90 LDD events (3 active, 87 passive) involving at least 56 extant species and 38 genera. Most events (73) involved the colonization of islands, with rafting being suggested as the most conceivable means of overwater passive dispersal for these vertebrates. In this review, we show that LDD events have played an important role in shaping current amphibian biogeographic patterns, especially the occurrence of disjunct distributions and the colonization of islands.

The Chinese giant salamander (Andrias davidianus) is the biggest extant and endangered amphibian, which has an incongruous sex ratio during the artificial breeding process and is sex indistinguishable in appearance. The sex development mechanism of this rare species thus needs to be explored. We therefore conducted this study to explore the molecular mechanisms of sex hallmarks or gonad maintenance genes for CGS. In this study, we sequenced and analyzed the sexually mature male and female gonads of Chinese giant salamanders (CGSs) using RNA-seq technology and found a total of 15,063 differentially expressed genes (DEGs) in the testicular and ovarian tissues, of which 7973 (52.93%) were expressed in testicular and 7090 (47.07%) in ovarian tissues. Thirteen gonad DEGs were selected based on gene expression abundance and quantified in the muscle and skin tissues of both male and female CGSs. The results showed that these 13 DEGS, out of the 20 analyzed DEGs, were expressed in both the muscle and skin tissues and only two of them (Bmp15 and ZP3) were consistent in the muscle and skin compared to the gonads of CGSs of the two sexes. Overall, our study should provide an important reference for the sex-characteristics-related genes in this type of species, shedding new light on future research on this topic. [ABSTRACT FROM AUTHOR]

Translocations of captive-reared animals are commonly used to stabilize declining wildlife populations. However, captive-reared animals are often raised in conditions dissimilar to their release sites and lacking natural characteristics, which could alter movement patterns and postrelease survivorship. These patterns can be further altered by season of release and soft-release conditions. We reared juvenile Eastern Hellbenders (Cryptobranchus alleganiensis alleganiensis) for 18 mo in captivity in one of two conditions: a control condition with low-velocity water flow (unconditioned) or a treatment condition with moving water (conditioned) that simulated natural flow velocities at their intended release site. We divided 4-yr-old Hellbenders (n = 118) into six treatment groups to determine the effects of release season (fall or summer), release type (standard soft release or enhanced soft release), and conditioning (unconditioned or conditioned) on the number of days until first movement, release site retention, and survival. In November 2017, we released 80 radio-tagged individuals (40 conditioned and 40 unconditioned) into soft-release structures in the Blue River, Indiana. In July 2018, we released another 38 radio-tagged individuals (18 conditioned and 20 unconditioned) into soft-release structures at the same site. After release, we tracked each individual one to three times weekly for 10 mo (fall release) or 12 mo (summer release). We found that treatment groups released into caged cobble beds (i.e., enhanced soft release) delayed their first movement and had higher release site retention relative to groups released under caged shelter rocks (i.e., standard soft release). We found that conditioning had a positive effect on survival but only in the treatment group released in the summer. By combining techniques and releasing conditioned individuals in the summer using enhanced soft releases, we increased annual survival of captive-reared Hellbenders from a probability of 0.50 (95% confidence interval [CI] = 0.31–0.79) to 0.74 (95% CI = 0.55–0.99). Our results provide important information about techniques that can be adopted across captive-rearing programs to help maximize the conservation success of Eastern Hellbenders. [ABSTRACT FROM AUTHOR]

Here, we p resent the etymology o f t he L atin b inomials o f all T urkish amphibian g enera a nd s pecies. A ccording to o ur review, the names are mostly given according to the characteristics and features of the species or in honor of a person. Reviewing the etymologies of the Latin names of amphibian species living in Türkiye and compiling information and heritage will be very useful, especially for Turkish herpetology. [ABSTRACT FROM AUTHOR]

Pupil constriction has important functional consequences for animal vision, yet the evolutionary mechanisms underlying diverse pupil sizes and shapes are poorly understood. We aimed to quantify the diversity and evolution of pupil shapes among amphibians and to test for potential correlations to ecology based on functional hypotheses. Using photographs, we surveyed pupil shape across adults of 1294 amphibian species, 74 families and three orders, and additionally for larval stages for all families of frogs and salamanders with a biphasic ontogeny. For amphibians with a biphasic life history, pupil shape changed in many species that occupy distinct habitats before and after metamorphosis. In addition, non-elongated (circular or diamond) constricted pupils were associated with species inhabiting aquatic or underground environments, and elongated pupils (with vertical or horizontal long axes) were more common in species with larger absolute eye sizes. We propose that amphibians provide a valuable group within which to explore the anatomical, physiological, optical and ecological mechanisms underlying the evolution of pupil shape. [ABSTRACT FROM AUTHOR]

The composition of cutaneous (skin-associated) bacterial communities of amphibians has been intensively studied in light of the potential of some of these commensal bacterial taxa to mitigate infection with the chytrid fungi Batrachochytrium dendrobatidis (Bd) and B. salamandrivorans (Bsal). However, surprisingly, the absolute densities in which these bacteria occur on the skin are only poorly known. We here combine quantification of bacterial 16SrDNA copies from skin swabs by quantitative PCR with counts from scanning electron microscopy (SEM) images to assess and compare bacterial abundances on the skin of various central European amphibians. We focus on the fire salamander (Salamandra salamandra) which is severely threatened by the spread of Bsal. Based on counts from SEM pictures of selected skin parts, local densities of ~43,000 bacteria per mm² were ascertained in frogs, although the data are insufficient to understand whether these values apply to the whole body surface. Bacterial densities are doubtless much lower in fire salamanders in which we observed almost no bacteria in SEM examination. From qPCR data, we find: (i) statistically relevant differences in bacterial abundances among species, with the lowest abundances in terrestrial salamanders and the highest abundances in toads; (ii) higher bacterial loads in captive compared to wild fire salamanders, and much higher loads in Bsal-infected captive specimens, in agreement with the hypothesis that Bsalinfection leads to blooming of opportunistic bacteria that may cause secondary infection; (iii) an only weak decrease of bacterial load after repeated swabbing, in agreement with the hypothesis that skin swabs capture only a part of the bacteria of the swabbed skin surface. We discuss the multiple sources of uncertainty in absolute estimates of abundances of cutaneous bacteria and suggest further research to clarify and reduce these uncertainties. [ABSTRACT FROM AUTHOR]

An incomplete salamander dentary (AMNH FARB 22965) described herein from the upper Maastrichtian Lance Formation, Wyoming, USA, exhibits a puzzling suite of features. Four features—a prominent bony trough extending anteriorly and curving upwards along the lingual surface of the ramus, lack of an obvious Meckelian fossa or groove, an apparent gap in the tooth row, and a symphysial-like first tooth—are likely anomalies. However, the remaining features are interpreted as normal structures and suggest that AMNH FARB 22965 represents a new genus and species of batrachosauroidid, an extinct family of neotenic salamanders that were prominent components of Cretaceous to Neogene freshwater and floodplain paleocommunities in North America and Europe. The new taxon differs from other batrachosauroidids in a unique suite of dentary and dental features, most notably in having a lingual bony flange paralleling the posterior two-thirds of the dentary tooth row, a prominent and robust coronoid process bearing a grooved anterior face, and the anterior portion of the corpus dentalis behind the symphysis is broadly expanded ventrolingually. The presence of a third batrachosauroidid taxon in the Lance Formation was unexpected, considering that the formation has been well sampled and that its two previously recognized batrachosauroidids, namely Opisthotriton kayi and Prodesmodon copei, are known by abundant isolated bones, including dozens of dentaries, from numerous localities in the unit and elsewhere in the North American Western Interior. Known by a unique dentary from the Bushy Tailed Blowout locality, the taxon represented by AMNH FARB 22965 evidently was uncommon within the Lance Formation paleoenvironment.

Studies on the skin microbiota of amphibians in different disturbed habitats can clarify the relationship between the skin microbiota composition and environmental factors and have practical implications for the conservation of endangered species. In this study, 16S rRNA high-throughput sequencing was used to profile the skin microbiota of Maoershan hynobiids (Hynobius maoershanensis). Our results illustrate that the alpha diversity of the skin microbiota significantly differed among individuals in higher anthropogenic disturbance-degree (HADD) habitats and lower anthropogenic disturbance-degree (LADD) habitats. The diversity of the skin microbiota in forelimb bud-stage tadpoles from HADD habitats was higher than that in their counterparts from LADD habitats. The richness of the skin microbiota in hindlimb bud-stage tadpoles was greater in HADD habitats than in LADD habitats. However, the alpha diversity of the adult skin microbiota did not differ significantly between the two habitats. Furthermore, stepwise regression analysis indicated that the skin microbiota diversity and relative abundance of dominant bacteria decreased with increasing air temperature, water temperature, and pH; conversely, skin microbiota richness increased with increasing humidity. In addition, the relative abundance of dominant bacteria was influenced by anthropogenic disturbance. We conclude that the skin microbiota of Maoershan hynobiids is affected by ecological factors and anthropogenic disturbance, highlighting the importance of the skin microbiota in response to habitat alteration.

Abstract Although paedomorphosis is widespread across salamander families, only two species have ever been documented to exhibit paedomorphosis in Hynobiidae. One of these two exceptional species is Hynobius retardatus in which paedomorphosis was first reported in 1924, in specimens from Lake Kuttara in Hokkaido. This population became extinct after the last observation in 1932; since then, no paedomorphs of this species have been reported anywhere. Here, we report the rediscovery of paedomorphs of this species. Three paedomorph-like male salamanders were collected from a pond in the south Hokkaido in December 2020 and April 2021; in size, these specimens were similar to metamorphosed adults but they still displayed larval features such as external gills and a well-developed caudal fin. An artificial fertilization experiment demonstrated that they were sexually compatible with metamorphosed females, thus, confirming them to be paedomorphs. Future efforts to find additional paedomorphs in this and other populations are required to assess the prevalence of paedomorphosis in H. retardatus and to improve understanding of the ecology and evolution of paedomorphisis in Urodela.

Climate change can affect species distribution patterns in three different ways: pushing them to disperse to new suitable areas, forcing them to adapt to novel climatic conditions, or driving them to extinction. However, the biological and geographical traits that lead to these different responses remain poorly explored. Here, we evaluated how ecological and biogeographic traits influence amphibians’ response to climate change. We performed a systematic review searching for studies that evaluated the effects of future climate change on amphibian’s distribution. Our research returned 31 articles that projected the distribution of 331 amphibians. Our results demonstrate that species inhabiting an elevation above 515 m will lose a significant portion of their climatically suitable area. We also found that as isothermality increases, the amount of area suitable in response to climate change also increases. Another important discovery was that as the size of the baseline area increases, the greater must be the loss of climatically suitable areas. On the other hand, species with very small areas tend to keep their current climatically suitable area in the future. Furthermore, our results indicate that species that inhabit dry habitats tend to expand their suitable area in response to climate change. This result can be explained by the environmental characteristics of these habitats, which tend to present extreme seasonal climates with well-defined periods of drought and rain. We also found that anurans that inhabit exclusively forests are projected to lose a greater portion of their suitable areas, when compared to species that inhabit both forest and open areas, wetlands, and dry and rupestrian environments. The biogeographical realm also influenced anuran’s range shifts, with Afrotropic and Nearctic species projected to expand their geographical ranges. The assessment of climate change effects on amphibian distribution has been the focus of a growing number of studies. Despite this, some regions and species remain underrepresented. Current literature evaluates about 4% of the 7,477 species of Anura and 8% of the 773 species of Caudata and some regions rich in amphibian species remain severely underrepresented, such as Madagascar. Thus, future studies should focus on regions and taxas that remain underrepresented.

Realistic predictions about the impacts of climate change onbiodiversity requires gathering ecophysiological data and the critical thermal maxima (CTMax) is the most frequently used index to assess the thermal vulnerability of species. In the present study, we performed a systematic review to understand how acclimation and altitude affect CTMax estimates for amphibian and non-avian reptile species. We retrieved CTMax data for anurans, salamanders, lizards, snakes, and turtles/terrapins. Data allowed to perform a multilevel random effects meta-analysis to answer how acclimation temperature affect CTMax of Anura, Caudata, and Squamata and also meta-regressions to assess the influence of altitude on CTMax of frogs and lizards. Acclimation temperature influenced CTMax estimates of tadpoles, adult anurans, salamanders, and lizards, but not of froglets. In general, the increase in acclimation temperature led to higher CTMax values. Altitudinal bioclimatic gradient had an inverse effect for estimating the CTMax of lizards and anuran amphibians. For lizards, CTMax was positively influenced by the mean temperature of the wettest quarter. For anurans, the relationship is inverse; we recover a trend of decreasing CTMax when max temperature of warmest month and precipitation seasonality increase. There is an urgent need for studies to investigate the thermal tolerance of subsampled groups or even for which we do not have any information such as Gymnophiona, Serpentes, Amphisbaena, and Testudines. Broader phylogenetic coverage is mandatory for more accurate analyses of macroecological and evolutionary patterns for thermal tolerance indices as CTMax.

Biodiversity is declining worldwide with habitat loss and climate change being among the main threats. While it is easy to quantify habitat loss, the impacts of climate change are less obvious. It is therefore important to understand species habitat use and breeding phenology before a significant shift results in the loss of knowledge. Here, we determined the habitat use and breeding phenology for all Korean amphibian species based on citizen science (8,763 observations), collected between 1997–2020. We found the breeding seasons as we defined them to be generally shorter than described in the literature despite large variations between species. Species were further dichotomised into early and late breeders with breeding periods peaking in mid-March and mid-June respectively. We found early breeding species to have a shortened hibernating period with only six days being consistently devoid of observations over the 23 years of the period studied for the species with the shortest inactive season. Habitat use was significantly different between all species, with pair-wise comparisons highlighting greater differences among rather than within genera, highlighting the threats to species across all genera. In addition, our results set a baseline for future analyses about climate change and habitat use.

Ponds in agricultural landscapes are often used by amphibians as breeding habitat. However, the characteristics of agricultural ponds and especially the surrounding area are usually said to be suboptimal for many amphibian species. Using suboptimal habitats might allow a species’ survival and reproduction, but can have negative consequences at the individual and population level. In the present study, we investigated Palmate Newt (Lissotriton helveticus) populations from an intensive wine-growing region in southern Germany and compared them with populations located in a nearby forested area in terms of biometric traits, age and genetic structure. By analyzing over 900 adult newts from 11 ponds, we could show that newts reproducing in forest ponds were larger than newts reproducing in agricultural ponds. We did not find differences in the newt age and growth rate between habitat types. Therefore, differences in the body size of newts might already existed in larvae and/or juveniles, what might be related to a lower habitat quality for larvae and/or juveniles in the agricultural landscape. Body mass, body condition and sexual dimorphic traits (length of the caudal filament and max. height of the tail) correlated with body size, but no additional effect of the habitat type was found. The analysis of microsatellites revealed a higher genetic diversity in forest ponds. However, no clear sign of inbreeding was observed in any agricultural population, suggesting some degree of gene flow between them. We conclude, that agricultural ponds can be suitable habitats for the Palmate Newt and that conservation effort should aim to preserve them. The observed effects on body size indicate the need to increase the quality of the aquatic and terrestrial habitat for early life stages of this newt species in agricultural landscapes. [ABSTRACT FROM AUTHOR]

Objective: To determine the protein nutritional requirements in juvenile axolotls, for this purpose, four isocaloric diets (8 % lipids) with 30, 35, 30 and 45 % protein were prepared. Design/methodology/approach: Six axolotls were used per test, during a period of 81 days. The diets were prepared using fishmeal as a protein source and fish oil as a lipid source. The feed was supplied every 48 hours with 4% of the weight of the biomass of organisms per experimental reservoir. Four biometries were performed throughout the experiment and growth parameters were determined: height, weight gained per day, specific growth rate, survival, Fulton's K, and protein efficiency rate. The digestibility of each of the diets was also determined. Results: There were significant differences (p> 0.05) in the growth and survival of the axolotls, the diet with 45% protein showed the best growth results. Limitations/Implications: No more protein levels could be tested, due to the number of organisms available for bioassays. Findings/conclusions: Diets for A. mexicanum containing 45% protein level promote good development and survival. This allows for improved cultivation and management plans for the species. [ABSTRACT FROM AUTHOR]

Amphibians undergo a variety of post‐embryonic transitions (PETr) that are partly governed by thyroid hormone (TH). Transformation into a terrestrial form follows an aquatic larval stage (biphasic) or precedes hatching (direct development). Some salamanders maintain larval characteristics and an aquatic lifestyle into adulthood (paedomorphosis), which obscures the conclusion of their larval period. Paedomorphic axolotls exhibit elevated TH during early development that is concomitant with transcriptional reprogramming and limb emergence. A recent perspective suggested this cryptic TH‐based PETr is uncoupled from metamorphosis in paedomorphs and concludes the larval period. This led to their question: "Are paedomorphs actual larvae?". To clarify, paedomorphs are only considered larval in form, even though they possess some actual larval characteristics. However, we strongly agree that events during larval development inform amphibian life cycle evolution. We build upon their perspective by considering the evolution of limb emergence and metamorphosis. Limbless hatchling larval salamanders are generally associated with ponds, while limbed larvae are common to streams and preceded the evolution of direct development. Permian amphibians had limbed larvae, so their PETr was likely uncoupled from metamorphosis, equivalent to most extant biphasic and paedomorphic salamanders. Coupling of these events was likely derived in frogs and direct developing salamanders. Key Findings: Paedomorphs are only larval in form.Limbed larvae preceded the evolution of direct development.Limb emergence and metamorphosis are ancestrally uncoupled in amphibians.Coupling of limb emergence and metamorphosis is derived in frogs and direct developing salamanders.Limb emergence and metamorphosis are secondarily uncoupled (decoupled) in biphasic plethodontids. [ABSTRACT FROM AUTHOR]

The spectral characteristics of vertebrate ocular lenses affect the image of the world that is projected onto the retina, and thus help shape diverse visual capabilities. Here, we tested whether amphibian lens transmission is driven by adaptation to diurnal activity (bright light) and/or scansorial habits (complex visual environments).Spectral transmission through the lenses of 79 species of frogs and six species of salamanders was measured, and data for 29 additional frog species compiled from published literature. Phylogenetic comparative methods were used to test ecological explanations of variation in lens transmission and to test for selection across traits.Lenses of diurnal (day‐active) and scansorial (climbing) frogs transmitted significantly less shortwave light than those of non‐diurnal or non‐scansorial amphibians, and evolutionary modelling suggested that these differences have resulted from differential selection.The presence of shortwave‐transparent lenses was common among the sampled amphibians, which implies that many are sensitive to shortwave light to some degree even in the absence of visual pigments maximally sensitive in the UV. This suggests that shortwave light, including UV, could play an important role in amphibian behaviour and ecology.Shortwave‐absorbing lens pigments likely provide higher visual acuity to diurnally active frogs of multiple ecologies and to nocturnally active scansorial frogs. This new mechanistic understanding of amphibian visual systems suggests that shortwave‐filtering lenses are adaptive not only in daylight conditions but also in those scotopic conditions where high acuity is advantageous. Read the free Plain Language Summary for this article on the Journal blog. [ABSTRACT FROM AUTHOR]

We review the use of reproduction technologies (RTs) to support the sustainable management of threatened Caudata (salamanders) and Gymnophiona (caecilian) biodiversity in conservation breeding programs (CBPs) or through biobanking alone. The Caudata include ∼760 species with ∼55% threatened, the Gymnophiona include ∼215 species with an undetermined but substantial number threatened, with 80% of Caudata and 65% of Gymnophiona habitat unprotected. Reproduction technologies include: (1) the exogenous hormonal induction of spermatozoa, eggs, or mating, (2) in vitro fertilisation, (3) intracytoplasmic sperm injection (ICSI), (4) the refrigerated storage of spermatozoa, (5) the cryopreservation of sperm, cell or tissues, (6) cloning, and (7) gonadal tissue or cell transplantation into living amphibians to eventually produce gametes and then individuals. Exogenous hormone regimens have been applied to 11 Caudata species to stimulate mating and to 14 species to enable the collection of spermatozoa or eggs. In vitro fertilisation has been successful in eight species, spermatozoa have been cryopreserved in seven species, and in two species in vitro fertilisation with cryopreserved spermatozoa has resulted in mature reproductive adults. However, the application of RTs to Caudata needs research and development over a broader range of species. Reproduction technologies are only now being developed for Gymnophiona, with many discoveries and pioneering achievement to be made. Species with the potential for repopulation are the focus of the few currently available amphibian CBPs. As Caudata and Gymnophiona eggs or larvae cannot be cryopreserved, and the capacity of CBPs is limited, the perpetuation of the biodiversity of an increasing number of species depends on the development of RTs to recover female individuals from cryopreserved and biobanked cells or tissues. The survival of many salamander and caecilian species requires the targeting and development of biotechnologies to produce offspring from cryopreserved sperm, to lower the costs and increase the reliability of conservation breeding programs. The colonisation of space will also be intimately dependent on the use of cryopreserved biomaterial for terraforming. Cryopreserved sperm has produced mature offspring in salamanders. However, more research and development is needed before the general application of reproduction technologies for salamanders or caecilians. [ABSTRACT FROM AUTHOR]

Background West Siberia is a large region in North Eurasia, which harbours multiple climatic zones, landscape types and biomes. Its amphibian fauna is characterised by a combination of European and Asian species. For many species, this region is the place where the limits of their global ranges are located (Rana temporaria, R. amurensis, Bufotes sitibundus). West Siberia also has at least two non-native amphibian species (Pelophylax ridibundus, Bufotes viridis). The exact ranges and patterns of distribution of the West Siberian amphibian species are poorly studied. The mapping of species ranges is important for the development of conservation measures and monitoring of invasive species is required to investigate their impacts on the natural ecosystems. New information This work presents the most complete biogeographic and occurrence records database of the amphibians of West Siberia. To assemble the database, we digitised data from 190 published works, obtained data from major museum collections and from the data bank on the abundance and distribution of animals «Zoomonitor» by the Zoomonitoring laboratory of the Institute of Systematics and Ecology of Animals, Siberian Branch of Russian Academy of Sciences. The database also includes original and partly unpublished data collected by the authors from 1975 to 2021, as well as quality-assessed citizen science data from the iNaturalist portal. In total, the database contains 2530 records for 11 species of amphibians, including the locality data, the observation date (when known) and the source of the observation (at least one of the following: literature reference, museum sample ID, observer’s name, iNaturalist link). [ABSTRACT FROM AUTHOR]

Calotriton arnoldi is an endemic amphibian inhabiting Montseny Natural Park and Biosphere Reserve (PNRBM), listed as "critically endangered (CR)" by IUCN. At the end of 2016, the Life Tritó del Montseny (LIFETM) project (LIFE15 NAT/ES/000757) was launched. The aim of the project was to promote around fifty actions to ensure the conservation of C. arnoldi and its natural habitat, and this entailed five strategic lines: (1) Increasing the scientific and technical knowledge with regard to C. arnoldi's conservation status and its habitat management. (2) Expanding its geographic distribution. (3) Involving and engaging stakeholders in the conservation of the Montseny brook newt. (4) Eliminating or minimizing threats that exist in the riparian habitat. (5) Establishing proper legal coverage and defining long-term strategic planning. The successes and failures experienced throughout the process provide us with essential information that will enable us to develop an adaptive management of the habitat. In order to eliminate or minimize threats to the newt's habitat, some of the actions that are currently being carried out are: (a) Land acquisitions and land exchanges with private properties. (b) Land stewardship procedures, with two custody agreements being signed. (c) Reduction of water withdrawal with nine water catchments and distribution being remodeled. (d) Improvement of water treatments and storage by installing ecological wastewater treatment facilities. (e) Ensuring ecological connectivity and riparian forest restoration. Here, we present an evaluation of the actions carried out to improve the habitat of this species, including the necessary considerations for them to be implemented correctly and to be successful in a natural area, which is under public-private management. [ABSTRACT FROM AUTHOR]

Computer-aided individual recognition of animals based on their natural markings has become an indispensable tool in ecology research. However, this is problematic in species with faint patterns. Here we test whether individually reared larvae of the European Fire Salamander (Salamandra salamandra) can be reliably recognized from images of their lateral tail patterns. We used Wild-ID software to (1) estimate the recognition uncertainty resulting from pre-processing the images, (2) quantify how pre-contrasting improves recognition, (3) assess the effect of ontogenetic pattern change on recognition until metamorphosis, and (4) test how recognition performs with larger image libraries. Our results show that discrimination of larvae is highly successful. Pre-processing did not lead to a relevant change in the recognition probability, while pre-contrasting even reduced the recognition probability. The shorter the time interval between two photos, the more readily an individual will be recognized. The overall recognition rate was 99.81%, with false rejection rates (FRR, calculated as the number of falsely rejected images divided by the number of matching attempts) amounting to 4.66, 0.77 and 0.20% for FRR1 (first image provided by Wild-ID does not match), FRR10 (none of the first ten images provided by Wild-ID matches) and FRR21 (none of the first 20 images provided by Wild-ID matches), respectively. These rates are among the lowest ever reported. The inclusion of images of 130 wild-caught larvae did not negatively affect successful individual recognition. Automated photo-identification may therefore be considered a reliable tool for fieldwork on European Fire Salamander larvae. [ABSTRACT FROM AUTHOR]

An incomplete salamander dentary (AMNH FARB 22965) described herein from the upper Maastrichtian Lance Formation, Wyoming, USA, exhibits a puzzling suite of features. Four features--a prominent bony trough extending anteriorly and curving upwards along the lingual surface of the ramus, lack of an obvious Meckelian fossa or groove, an apparent gap in the tooth row, and a symphysial-like first tooth--are likely anomalies. However, the remaining features are interpreted as normal structures and suggest that AMNH FARB 22965 represents a new genus and species of batrachosauroidid, an extinct family of neotenic salamanders that were prominent components of Cretaceous to Neogene freshwater and floodplain paleocommunities in North America and Europe. The new taxon differs from other batrachosauroidids in a unique suite of dentary and dental features, most notably in having a lingual bony flange paralleling the posterior two-thirds of the dentary tooth row, a prominent and robust coronoid process bearing a grooved anterior face, and the anterior portion of the corpus dentalis behind the symphysis is broadly expanded ventrolingually. The presence of a third batrachosauroidid taxon in the Lance Formation was unexpected, considering that the formation has been well sampled and that its two previously recognized batrachosauroidids, namely Opisthotriton kayi and Prodesmodon copei, are known by abundant isolated bones, including dozens of dentaries, from numerous localities in the unit and elsewhere in the North American Western Interior. Known by a unique dentary from the Bushy Tailed Blowout locality, the taxon represented by AMNH FARB 22965 evidently was uncommon within the Lance Formation paleoenvironment. [ABSTRACT FROM AUTHOR]

The island of Newfoundland has no native amphibian taxa, although six species of Anura (i.e., frogs and toads) have been introduced since European colonisation, four of which have established self-sustaining populations. Here, we document Eastern Red-backed Salamander (Plethodon cinereus) on Newfoundland for the first time, in what appears to be a self-sustaining population near Conception Bay South. This is the first species of Caudata (i.e., newts and salamanders) to have been introduced to the island, as well as the first occurrence of Eastern Red-backed Salamander establishing a population outside its native range. The impact that this non-native species might have on forest ecosystems on Newfoundland is unclear and further study is required to determine whether eradication of the species from Newfoundland is necessary or feasible. [ABSTRACT FROM AUTHOR]

Abstract The worldwide biodiversity crisis with the resulting need to increase species protection has led researchers to pursue and select survey methods that guarantee the best quality of data and produce the least negative effects on wild animals. Plethodontids are the most diverse family of salamanders; all species are very sensitive to human handling and noninvasive, but accurate, measurement methods are needed to reduce researchers’ impact. Here, we tested the reliability of a noninvasive post hoc method in estimating the snout–vent length (SVL) from photographs showing salamanders’ dorsal view. The correlation between the estimated snout–vent length (SVLe) and the conventional SVL was high (R2m = .81), and no significant difference occurred between operators with different experience. Finally, we list the numerous advantages for the use of SVLe in terms of data quality and in reducing the stress caused to wild animals.

Although paedomorphosis is widespread across salamander families, only two species have ever been documented to exhibit paedomorphosis in Hynobiidae. One of these two exceptional species is Hynobius retardatus in which paedomorphosis was first reported in 1924, in specimens from Lake Kuttara in Hokkaido. This population became extinct after the last observation in 1932; since then, no paedomorphs of this species have been reported anywhere. Here, we report the rediscovery of paedomorphs of this species. Three paedomorph-like male salamanders were collected from a pond in the south Hokkaido in December 2020 and April 2021; in size, these specimens were similar to metamorphosed adults but they still displayed larval features such as external gills and a well-developed caudal fin. An artificial fertilization experiment demonstrated that they were sexually compatible with metamorphosed females, thus, confirming them to be paedomorphs. Future efforts to find additional paedomorphs in this and other populations are required to assess the prevalence of paedomorphosis in H. retardatus and to improve understanding of the ecology and evolution of paedomorphisis in Urodela. [ABSTRACT FROM AUTHOR]

The growing availability of genetic data sets, in combination with machine learning frameworks, offers great potential to answer long‐standing questions in ecology and evolution. One such question has intrigued population geneticists, biogeographers, and conservation biologists: What factors determine intraspecific genetic diversity? This question is challenging to answer because many factors may influence genetic variation, including life history traits, historical influences, and geography, and the relative importance of these factors varies across taxonomic and geographic scales. Furthermore, interpreting the influence of numerous, potentially correlated variables is difficult with traditional statistical approaches. To address these challenges, we analysed repurposed data using machine learning and investigated predictors of genetic diversity, focusing on Nearctic amphibians as a case study. We aggregated species traits, range characteristics, and >42,000 genetic sequences for 299 species using open‐access scripts and various databases. After identifying important predictors of nucleotide diversity with random forest regression, we conducted follow‐up analyses to examine the roles of phylogenetic history, geography, and demographic processes on intraspecific diversity. Although life history traits were not important predictors for this data set, we found significant phylogenetic signal in genetic diversity within amphibians. We also found that salamander species at northern latitudes contained low genetic diversity. Data repurposing and machine learning provide valuable tools for detecting patterns with relevance for conservation, but concerted efforts are needed to compile meaningful data sets with greater utility for understanding global biodiversity. [ABSTRACT FROM AUTHOR]

Derjugin's Mountain Newt (Neurergus derjugini derjugini) inhabits the Zagros Mountains in northeastern Iraq and western Iran. The present study was conducted in Rikhalan village (Mirisour stream) in Marivan County, western Kurdistan Province, to determine habitat requirements and population size of Derjugin's Mountain Newt. From April through May 2020, the capture-mark-release-recapture technique was used to estimate population size. Habitat parameters including pH, dissolved oxygen and electrical conductivity of water, water and air temperature, the size of bedrocks, water flow speed, and canopy and aquatic vegetation cover were measured. A total of 3175 specimens of Derjugin's Mountain Newt (1853 males, 1322 females) were captured and recaptured. Population size was estimated using the software CAPTURE and the Jolley-Seber method. According to the results obtained by means of the MARK and Ecological Methodology software, the population size of Derjugin's Mountain Newt in the study area was between 2401 and 2554/1664 m², 1165 and 2877/1664 m², respectively. Habitat preferences of Derjugin's Mountain Newt in the Mirisour Stream are clear shallow water with a slow flow speed, pH 8.23--8.36, electrical conductivity 292--331 µS/cm, dissolved oxygen 7.26--8.42 mg/l, water temperature 12--17.5°C, and vegetation to include oak (Quercus brantii, Q. infectoria), plane (Platanus orientalis), walnut (Juglans regia), and willow (Salix spp.) while the aquatic vegetation consists of broadleaf (Mentha sp.) and orchard grass (Dactylis glomerata). Presence and abundance of this species were considerably higher at greater altitudes. The key threat to the species is habitat loss, which is caused by water being siphoned off for agricultural purposes and blocking springs as a result. [ABSTRACT FROM AUTHOR]